Note: Descriptions are shown in the official language in which they were submitted.
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TENSIQN RESPONSIVE PIN~H VALVE
FIELD OF THE INVENTION
The invention generally relates to valves that will
automatically close the lumen of flexible tubing or hoses and
are tension responsive, opening o~ly when the valve section of
the tubing or hose is under sufficient longituainal tension
and closing when the tension is not being applied. The
invention relates more specifically to such valves that pinch
or kink the ~lexible tubing or hose shut to achieve a valving
e~fect.
R~CKGROUND QF THE T~VENTION
In a number of situations it would be desirable to have a
simple, inexpensive valve that will close the lumen of a
flexible tube or hose automatically so that a flow of liquid
through the tube or hose, usually under low or moderate
pressure, will be stopped when some predetermined condition
occurs until further flow is desired, yet have renewed ~low
easily attained. For example, in administering an enteral or
parenteral ~luid to a patient with a rotary peristaltic pump
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it is very important that flow of the fluid is regulated. If
the fluid delivery set employed with the peristaltic pump
should be accidentally dislodged from the pump housing so that
the pump rotor does not regulate fluid flow it would be very
desirable to have some means that will automatically shut off
the flow of fluid until the problem is observed and the fluid
delivery set re-installed.
Various valve mechanisms have been employed to control
the flow of air as well as of liquids, but it appears that no
simple, inexpensive valves have been devised heretofore that
are suited for use in a setting where it is important to have
continuing regulated flow of liquid but automatic shut-of~ if
the flow should become un-regulated. In the case of the fluid
delivery sets used to administer enteral or parenteral fluids
into the body of a patient, the cost of any such precautionary
valve is an important consideration as the sets are used only
once and discarded.
U.S. Patent 2,444,449 discloses a valving arrangement for
the inflation of breath-inflatable containers such as life
preservers and air cushions which have a so~t rubber valve
stem that is adapted to be folded on itsel~ to retain air in
the container. Two elastic members are each attached by a
respective band to the base and to the free end of the valve
stem at spaced apart fastening locations, with the elastic
members brought together by a "keeper" at about the mid-length
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of the valve stem. By proper selection of the material of
which the valve stem is formed, and of elastic members with an
appropriate level of elastic yield strength, the valve stem
~ will be capable of standing erect unaided against the pull of
the elastic members, once it is straightened out with some
compressive squeezes to remove the kink. When it is desired to
close the valve stem it is simply bent over m~nll~lly and the
elastic members will keep it bent. Thus, it can be seen that
this valving device does not provide for continuous regulated
flow of liquid through a flexible tubing with automatic valve
shut-off if the flow of liquid should become unregulated.
U.S. Patent 2,002,835 discloses a valving arrangement for
the control of the discharge of an aerified or gasified liquid
from a bottle or other enclosed container from which the
liquid will "siphon" when a discharge tube from the container
is opened. The valving arrangement is constituted by a hollow
closure element in the form of a kind of stopper for a bottle
or flask. A flexible discharge tube extends upwardly from
near the bottom of the bottle or ~lask and through the stopper
and part way through an upstanding flexible hollow heavy-
walled tubular extension of the stopper. The tubular extension
loosely surrounds and extends beyond the end of the discharge
tube. At about mid-length of the tubular extension the walls
are thinner and the tubular extension readily bends over of
its own weight and bends the discharge tube with it
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su~ficiently to pinch or kink the discharge tube shut,
precluding discharge. The drooping end o~ the tubular
extension is easily li~ted manually to permit gasified liquid
under pressure to discharge, and upon allowing the end to drop
down again, the discharge tube is bent su~iciently to shut
o~ liquid flow. This device, then, is not automatic in
operation.
U.S. Patents 3,976,277 and 2,957,607 disclose an
apparatus for dispensing liquids through a ~lexible tubing
wherein solenoid-operated pinch tube means are used to
compress the ~lexible tubing to control passage o~ liquid
therethrough. The valve is not per se automatic, requiring
mechanical means that must be activated to do the pinching.
U.S. Patent 4,063,706 discloses a pinch valve ~ormed from
a wire helix and a flexible tube ~or the control o~ liquid
~low through the ~lexible tube. The control is done manually
and the valve is not tension responsive.
U.S. Patent 4,620,564 discloses a device for regulating
~low o~ liquid through a tube by twisting the tubing
mechanically, the tube actually having ~ormed therein a
plurality o~ substantially parallel ~low passages that close
o~ as the tube is twisted. The operation is not responsive to
either ~low rate or longitn~;n~l tension on the tube.
British patents 16,321; 634,975; and 1,149,915 disclose
valves ~or closures o~ tubes or other structures with the
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twisting of the tube mechanically or of an iris kind of
mechanism like a camera aperture control.
U.S. Patents 3,995,780; 2, 555,490; 4,109,486; 2,117,071;
and 5, 072, 855 each disclose some form of pressure responsive
valve controlling discharge oE a slurrv or paste ~rom some
kind of vessel or collapsible tube upon mechanically applied
pressure or in some cases pressure manually applied.
SUMMARY OF THE INV~NTION
The tension responsive pinch valve of the invention is
made up of a combination of an elastically flexible valve
element and a length of flexible tubing having a section that
is to be closed, i.e., occluded, by being twisted, bent or
doubled over or otherwise deformed automatically to the point
of kinking or p;nch;ng shut the lumen of the tubing when the
valve is not under tension. The valve element is associated
with the section of the length of flexible tubing that is to
be closed when not under tension.
In a pre~erred embodiment the valve element is attached
to the exterior sur~ace o~ the section o~ ~lexible tubing and
has end portions connected by a middle portion in the form o~
a shank portion. The end portions are attached to the flexible
tubing at spaced apart points longitu~;n~lly o~ the section
such that the length of the section encompassed between the
spaced apart points is much longer than the shank portion of
the valve element and o~ an appropriate length to bend or
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twist sharply and pinch shut the tubing when the end portions
o~ the valve elements are pulled mutually closer by the shank
portion when the tubing is not under tension. Under tension
the shank portion is stretched and the tublng is unpinched or
unkinked enough to permit passage o~ fluid.
There is provided in accordance with one aspect o~ the
invention a tension responsive pinch valve comprising: an
assembly o~ an elastically flexible pinch valve element and a
length of ~lexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element being
~ixedly associated longitudinally with the section o~ the
length o~ ~lexible tubing and capable o~ distorting the
section to the point o~ pinching the lumen o~ the section shut
when the ~lexible tubing is not under tension, while allowing
the lumen to open when the ~lexible tubing is under tension
su~ficient to elongate the pinch valve element and at least
partially undo the distortion o~ the section o~ ~lexible
tubing.
There is provided in accordance with another aspect o~
the invention a tension responsive pinch valve comprising an
assembly o~ an elastically ~lexible pinch valve element and a
length o~ ~lexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element
comprising an elastic, ~lexible polymeric material and having
a pair o~ tubular segment end portions joined by a shank
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portion, the tubular segment end portions being telescopically
assembled with the ~lexible tubing and the pinch valve element
being capable of distorting the section of ~1exible tubing to
the point of pinching the lumen of the section of ~1exible
tubing shut when the flexible tubing is not under tension,
while allowing the lumen to open when the ~1exible tubing is
under tension sufficient to elongate the pinch valve element
and at least partially undo the distortion o~ the section o~
flexible tubing.
There is provided in accordance with another aspect of
the invention a tension responsive pinch valve comprising: an
assembly o~ an elastically flexible pinch valve element and a
length o~ ~lexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element
lS comprising an elastic, flexible polymeric material and having
a rectangular substantially planar shank portion connecting
rectangular substantially planar end portions each of which
has a concave sur~ace adapted to fit conformingly against an
outer cylindrical surface o~ the flexible tubing and is bonded
thereto, the pinch valve being capable of distorting the
section of flexible tubing to the point of p;nch;ng the lumen
of the section of ~lexible tubing shut when the ~1exible
tubing is not under tension, while allowing the lumen to open
when the ~lexible tubing is under tension su~icient to
elongate the pinch valve element and at least partially undo
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the distortion o~ the section o~ ~lexible tubing.
There is provided in accordance with another aspect o~
the invention a tension responsive pinch valve comprising: an
assembly o~ an elastically ~lexible pinch valve element and a v
length o~ ~lexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element
comprising an elastic, ~lexible polymeric matçrial and being
~ormed in the shape o~ the capital letter "I" ~rom a flat
sheet, the end portions o~ the "I" being wrapped substantially
around the ~lexible tubing and bonded thereto, the pinch valve
element being capable o~ distorting the section o~ ~lexible
tubing to the point o~ pinching the lumen o~ the section o~
~lexible tubing shut when the ~lexible tubing is not under
tension, while allowing the lumen to open when the ~lexible
tubing is under tension su~icient to elongate the pinch valve
element and at least partially undo the distortion of the
section o~ ~lexible tubing.
There is provided in accordance with another aspect o~
the invention a tension responsive pinch valve comprising: an
assembly o~ an elastically ~lexible pinch valve element and a
length o~ ~lexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element
comprising an elastic, ~lexible polymeric material and having
arcuate end portions that are joined by a shank portion having
an arcuate cross section, the end portions each having a
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concave surface that is mated with and bonded to the outer
surface o~ the flexible tubing, the pinch valve element being
capable of distorting the section of flexible tubing to the
point of pinching the lumen of the section of flexible tubing
shut when the ~lexible tubing is not under tension, while
allowing the lumen to open when the flexible tubing is under
tension suf~icient to elongate the pinch valve element and at
least partially undo the distortion of the section o~ flexible
tubing.
There is provided in accordance with another aspect of
the invention a tension responsive pinch valve comprising: an
assembly of an elastically flexible pinch valve element and a
length of flexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element being a
hemi-cylindrical sleeve shaped piece of an elastic, ~lexible
polymeric material, each end of the pinch valve element being
attached to the ~lexible tubing, the pinch valve element being
capable o~ distorting the section of flexible tubing to the
point of pinching the lumen of the section of flexible tubing
shut when the flexible tubing is not under tension, while
allowing the lumen to open when the flexible tubing is under
tension suf~icient to elongate the pinch valve element and at
least partially undo the distortion of the section of flexible
tubing.
There is provided in accordance with another aspect of
_
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- 10
the invention a tension responsive pinch valve comprising: an
assembly of an elastically flexible pinch valve element and a
length of flexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element
comprising an elastic, flexible polymeric material with the
pinch valve element having a pair of tubular segment end
portions joined by a shank portion, one of the end portions
being insert molded around the ~lexible tubing and the other
end portion being telescopically emplaced around the flexible
tubing and spaced apart from the first end portion by a
positioning collar which is insert molded around the flexible
tubing, the pinch valve element being capable of distorting
the section of flexible tubing to the point of pinching the
lumen of the section of flexible tubing shut when the flexible
tubing is not under tension, while allowing the lumen to open
when the flexible tubing is under tension sufficient to
elongate the pinch valve element and at least partially undo
the distortion of the section of flexible tubing.
There is provided in accordance with another aspect of
the invention a tension responsive pinch valve comprising: an
assembly of an elastically flexible pinch valve element and a
length of flexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element
comprising an elastic, flexible polymeric material and having
a pair of closed loop end portions joined by a shank portion,
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11
each end portion being telescopically emplaced around the
~lexible tubing, the pinch valve element being capable o~
distorting the section of ~lexible tubing to the point of
pinching the lumen of the section o~ ~lexible tubing shut when
the ~lexible tubing is not under tension, while allowing the
lumen to open when the ~lexible tubing is under tension
su~icient to elongate the pinch valve element and at least
partially undo the distortion o~ the section o~ ~lexible
tubing.
There is provided in accordance with another aspect o~
the invention a tension responsive pinch valve comprising: an
assembly o~ an elastically ~lexible pinch valve element and a
length of ~lexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element being a
sharply bent piece o~ a highly elastic springy material molded
into the wall o~ the ~lexible tubing, the pinch valve element
being capable o~ distorting the section o~ ~lexible tubing to
the point o~ pinching the lumen o~ the section o~ ~lexible
tubing shut when the ~lexible tubing is not under tension,
while allowing the lumen to open when the ~lexible tubing is
under tension su~ficient to elongate the pinch valve element
and at least partially undo the distortion o~ the section o~
~lexible tubing.
There is provided in accordance with another aspect o~
the invention a tension responsive pinch valve comprising: an
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assem~bly of an elastically flexible pinch valve element and a
length of flexible tubing having a lumen and a section to be
reversibly closed as a valve; the pinch valve element being a
sharply bent piece of a highly elastic springy material bonded
to the exterior of the wall of the flexible tubing, the pinch
valve element being capable of distorting the section of
~lexible tubing to the point of pinching the lumen o~ the
section of flexible tubing shut when the flexible tubing is
not under tension, while allowing the lumen to open when the
~lexible tubing is under tension sufficient to elongate the
pinch valve element and at least partially undo the distortion
of the section of flexible tubing.
B~T~F DESCRIPTION OF THE DR~WINGS
Fig. 1 is a perspective view of a pinch valve according
to the invention consisting o~ an elastic pinch valve element
together with a length of flexible tubing on which the valve
element has been installed;
Fig. 2 is a perspective view of the pinch valve element
of Fig. l;
Fig. 3 is a side view of a length of flexible tubing and
a flexible pinch valve element to be telescopically assembled
therewith to make a pinch valve, with portions of the flexible
tubing and pinch valve element identified to illustrate
relative ~;m~n~ions;
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Fig. 4 is a side view of a pinch valve made from the
components shown in Fig. 3;
Fig. 5 is a view in front elevation of a rotary
~ peristaltic pump and fluid delivery set assembled together
with a flexible pinch valve element telescopically installed
on the flexible tubing of the fluid delivery set adjacent the
pump rotor to make a pinch valve according to the invention,
the fluid delivery set being connected at the inlet end
thereof to a supply container of liquid enteral nutritional
product and at the discharge end thereof to a feeding tube
extending into the stomach of a patient whose abdomen is shown
in fragmentary view, partly broken away and in section;
Fig. 6 is a perspective view of a ~luid delivery set for
enteral or parenteral administration of a fluid using a rotary
peristaltic pump, there being a pinch valve according to the
invention installed on the flexible tubing of the fluid
delivery set with the valve closed in the absence of tension
on the flexible tubingi
Fig. 7 is a side view of the ~luid delivery set of Fig. 5
with tension on the flexible tubing whereby the pinch valve is
open;
Fig. 8 is a view in front elevation of the peristaltic
pump and fluid delivery set combination of Fig. 7 having a
pinch valve adjacent the pump rotor and with parts of the
flexible tubing of the fluid delivery set truncated and
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foreshortened;
Fig. 9 is a perspective view of the peristaltic pump and
fluid delivery set combination of Fig. 8;
Fig. 10 is a fragmentary view of a hanging supply
container for an enteral or parenteral fluid shown connected
to the inlet end of a fluid delivery set assembled with a
prior art rotary peristaltic pump, and having a pinch valve of
the invention adjacent the pump rotor;
Figs. 11 and 12, respectively, are perspective views of a
different pinch valve formed o~ a length of flexible tubing,
and of the pinch valve element therefor, this pinch valve
element not requiring telescopic assembly;
Figs. 13 and 14, respectively, are perspective views of a
different pinch valve and the pinch valve element therefor,
the pinch valve element not requiring telescopic assembly;
Figs 15 and 16 are perspective views similar to Figs. 13
and 14, respectively, of a different pinch valve and of the
pinch valve element therefor, this pinch valve element also
not reguiring telescopic assembly;
Fig. 16A is a view of the sur~ace, of the pinch valve
element seen in Fig. 16, that faces toward the flexible tubing
in the assembled pinch valve of Fig. lS;
Figs. 17 and 18 are perspective views similar to Figs. 15
and 16, respectively, o~ a di~erent pinch valve, and of the
pinch valve element therefor, this pinch valve element also
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not requiring telescopic assembly;
Fig. 19 is a perspective view o~ a length o~ ~lexible
tubing having a partly assembled pinch valve made thereo~ with
yet another ~orm o~ pinch valve element and with a collar on
the ~lexible tubing to serve as a position index or stop ~or
the installation o~ the second tubular segment end portion o~
the pinch valve element;
Fig. 20 is a perspective view o~ the pinch valve of Fig.
19 ~ully assembled, with that part o~ the ~lexible tubing
between the emplaced pinch valve element tubular segment end
portions doubled over to kink back on itsel~, pinching the
~lexible tubing shut;
Fig. 21 is a perspective view o~ the flexible tubing and
pinch valve ~ormed thereo~ depicted in Fig. 20 with the
~lexible tubing under su~icient longitudinal tension that the
pinch valve is open to ~luid ~low;
Fig. 22 is a side view o~ another elastic pinch valve
element suitable ~or assembly with a length o~ ~lexible tubing
to ~orm a pinch valve according to the invention;
Fig. 23 is a side view o~ another pinch valve made up
~rom the valve element o~ Fig. 22 and a length o~ ~lexible
tubing, shown truncated, with the ~lexible tubing not under
tension and doubled over and pinched between the end portions
of the pinch valve element as a result o~ the elastic pull o~
the shank portion;
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Fig. 24 is a side view of a pinch valve made up using the
pinch valve element of Fig. 22 and a flexible tubing, shown
truncated, with the ends of the flexible tubing under tension
by means not shown so that the elastic pull of the shank
portion of the pinch valve element is being overcome and the
flexible tubing is sufficiently straight for ready flow of
liquid through the valve;
Fig. 25 is a view in section of another form of tension
responsive pinch valve in which a bent spring wire capable of
bending flexible tubing sufficiently for occlusion is embedded
in the wall of a section of the flexible tubing;
Fig. 26 is a view in section taken along the line 26-26
of Fig. 25 showing the bent spring wire molded within the
tubing wall;
Fig. 26A is a view in section similar to Fig. 26 showing
another ~orm of the spring wire type of pinch valve depicted
in Fig. 25 in which the wire is molded or bonded
longitudinally along the outside of the flexible tubing;
Fig. 27 is a side view of another form of pinch valve in
which the pinch valve element, when suitably fixed in place on
a length of flexible tubing, makes the flexible tubing twist
enough for occlusion to take place when the flexible tubing is
not under tension;
Fig. 28 is a perspective view of the front and side of
apparatus for the assembly of the pinch valve of Figs. 1 and
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4;
Fig. 29 is a perspective view o~ the back and side o~ the
assembly apparatus o~ Fig. 28;
- Fig. 30 is a ~ront elevation view of the assembly
apparatus o~ Fig. 28;
Fig. 31 is very greatly enlarged ~ragmentary view of the
portion o~ Fig. 30 encircled by a dashed line;
Fig. 32 is a view in vertical section o~ the assembly
apparatus taken along the line 32-32 of Fig. 30;
Fig. 33 is an exploded perspective view o~ the components
o~ an assembly apparatus, such as the apparatus o~ Fig. 28,
with a corner o~ the base plate cut away for purposes o~
illustration;
Fig. 34 is a greatly enlarged perspective view o~ an
15 ejector block which may be used as a part o~ a sub-assembly
identi~ied by reference character 330 in Fig. 33;
Fig. 35 is a greatly enlarged perspective view o~ another
ejector block which may be used in a modification o~ the sub-
assembly identi~ied by re~erence character 330 in Fig. 33;
Fig. 36 is an enlarged exploded perspective view o~ some
o~ the components o~ the sub-assembly identi~ied by re~erence
character 330 in Fig. 33, including the ejector block o~ Fig.
34;
Fig. 37 is an enlarged exploded perspective view o~ all
25 the components o~ the subassembly identi~ied by re~erence
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character 330 in Fig. 33 with the components shown in Fig. 36
already assembled together;
Fig. 38 is a greatly enlarged perspective view o~ an "L"-
shaped spreader ~inger element showing the guide pin extending
laterally ~rom the leg portion;
Fig. 39 is a very greatly enlarged partly exploded
perspective view o~ the sub-assembly identified by re~erence
character 330 in Fig. 33 in the process o~ being assembled;
Fig. 40 is a very greatly enlarged perspective view of
the sub-assembly identi~ied by re~erence character 330 in Fig.
33;
Fig. 41 is a perspective view of the reverse or inside
~ace o~ the cover platei
Fig. 42 is a perspective view o~ the assembly apparatus
with the components o~ a pinch valve shown in exploded view
relationship about to be assembled using the assembly
apparatus;
Fig. 43 is a ~ragmentary perspective view o~ the assembly
apparatus shown with a ~irst tubular segment end portion o~
the pinch valve element oriented ~or placing over, i.e.,
around, the ~ingers o~ the spreader ~inger elements;
Fig. 44 is a view similar to Fig. 43 with the ~irst
tubular segment end portion o~ the pinch valve element slid
onto the cluster o~ spreader ~ingers to commence the assembly
process;
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19
Fig. 45 is a view in vertical section o~ the assembly
apparatus like that shown in Fig. 32, but with the first
tubular segment end portion o~ the pinch valve element
emplaced over the spreader ~ingers as in Fig. 44;
Fig. 46 is a perspective ~ragmentary view similar to Fig.
44 showing the ~irst tubular segment end portion o~ the pinch
valve element shown in Fig. 44 stretched open radially to
receive therethrough the length o~ ~lexible tubing upon which
the pinch valve element is to be telescopically assembled;
Fig. 47 is a ~ragmentary view in section o~ the assembly
apparatus and stretched ~irst tubular segment end portion o~
the pinch valve element shown in Fig. 46, and with the length
o~ ~lexible tubing inserted into the apparatus-over the
central guide rod and through the cluster o~ spreader ~ingers;
Fig. 48 is a ~ront elevation o~ the portion o~ the
assembly apparatus encompassed by the cover plate at the point
of the assembly process illustrated in Figs. 46 and 47;
Fig. 49 is a ~ragmentary view in section o~ the assembly
apparatus with the ~irst tubular segment end portion of the
pinch valve element relaxed upon the length o~ ~lexible tubing
and with the ejector piston moved ~orward;
Fig. 50 is a ~ront elevation o~ the portion o~ the
assembly apparatus encompassed by the cover plate at the point
of the assembly process illustrated in Fig. 49;
Fig. 51 is a ~ragmentary perspective view of assembly
_
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apparatus closely similar to that o~ Fig. 42 but adapted with
a longer ejector block ~or the next stage o~ assembling a
pinch valve assembly with the second tubular segment end
portion o~ the pinch valve element oriented ~or placing over,
i.e., around, the spreader ~ingers and with the leading end o~
the length o~ ~lexible tubing bent aside temporarily;
Fig. S2 is a view similar to Fig. 51 showing a further
step in the next stage of manu~acturing a pinch valve assembly
wherein the second tubular segment end portion is being
emplaced on the length o~ ~lexible tubing;
Fig. 53 is a ~ragmentary view in section o~ the
assembly apparatus with the tubular segment end portion o~ the
pinch valve element stretched open and the end portion o~ the
Elexible tubing doubled over as seen in Fig. S2 and inserted
into the assembly apparatus over the central guide rod and
through the cluster o~ spreader ~ingers
Fig. 54 is a ~ragmentary view in section o~ the assembly
apparatus similar to Fig. 53, but with the second tubular
segment end portion o~ the pinch valve element relaxed around
the length of ~lexible tubing and the ejector piston moved
~orward.
DFTAIT~Fn D~.~CRIPTION OF THE IN~r~NTION
For the purposes o~ the speci~ication and claims a
tension responsive pinch valve is understood to be the
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assembly of a section of a length of ~lexible tubing with a
pinch valve element wherein the pinch valve is capable of
bending or twisting the section of flexible tubing
.
sufficiently to close the lumen thereof to prevent the passage
of ~luid therethrough when the section or the tubing of which
it is a part is not under tension suf~icient to stretch or
straighten the pinch valve element.
In Figs. 1 and 4 there is depicted a pre~erred exemplary
embodiment of a pinch valve according to the invention. The
pinch valve is made up ~rom a pinch valve element, such as the
pinch valve element 80 shown in Figs. 2 and 3, and a section
o~ a length of flexible tubing 49, depicted in Figs. 1 and 4
as part of the pinch valve. The pinch valve element 80 is
formed o~ an elastic, flexible polymeric material, such as a
silicone rubber, and is assembled telescopically and extends
longitudinally along a section 75 of the flexible tubing 49 in
making up the pinch valve.
The pinch valve element 80 is seen to have tubular
segment end portions 82,83 joined by a shank portion 84. The
pinch valve element 80 can be made by ~lattening a short piece
of ~lexible tubing and stamping or cutting out about a half or
more of the width along the longitudinal mid-section leaving a
short, substantially hemi-cylindrical sleeve-shaped shank
portion 84 having about one third the overall length o~ the
valve element 80, and two foreshortened tubular segment end
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portions 82,83 of about equal length. The shank portion 84
should be of about the same length as each of the tubular
segment end portions 82, 83.
A pinch valve element, such as the pinch valve element
80, and a number of other similar non-metallic pinch valve
elements of the sort herein described, is made up from a
flexible, elastic polymeric material such as a silicone
rubber. Other pinch valve elements are made up of springy
material such as steel spring wire or a similarly springy
cured polymeric resin. The flexible polymeric tubing with
which the pinch valve element is assembled is a tubing made of
a silicone rubber or other similarly flexible polymeric
material.
When the pinch valve element 80 is telescopically
installed on section 75 of a length of flexible tubing, such
as flexible tubing 49 having an outer diameter at least as
great as the inner diameter of the tubular segment end
portions 82,33, and with the tubular segment end portions
positioned farther apart along the section 75 of the ~lexible
tubing than the length of the shank portion 84 by virtue o~
doubling over the section of tubing during assembly with the
valve element, with a length ratio of about 4:1, then
providing the shank portion 84 of the valve element 80 has a
sufficiently great elastic yield modulus to elongate the bend
modulus of the flexible tubing 49, the pinch valve element 80
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will draw up the ends o~ the encompassed section 75 o~
~lexible tubing 49 and bend it over and kink it so that the
tubing wall pinches together as seen in Figs. 1 and 4,
blocking any ~luid flow therethrough unless tension is applied
to straighten out the ~lexible tubing section 75 suf~iciently
to open the lumen 49a ~or ~luid ~low therethrough.
Brie~ly stated, a tension responsive pinch valve o~ the
present invention is an assembly o~ an elastically ~lexible
pinch valve element and a length o~ ~lexible tubing having a
lumen and a section to be reversibly closed as a valve. The
pinch valve element is ~ixedly associated longitudinally with
the length of ~lexible tubing and is capable o~ distorting the
length o~ ~lexible tubing to the point o~ p;nC~;ng the lumen
of the section o~ ~lexible tubing shut when the flexible
tubing is not under tension. However, the tension responsive
pinch valve assembly allows the lumen to open when the
~lexible tubing is under tension su~icient to elongate the
pinch valve element and at least partially undo the distortion
o~ the section o~ ~lexible tubing.
The relative lengths are very important. The encompassed
section o~ the ~lexible tubing must be long enough that the
shank portion o~ the pinch valve element will exert
substantial longitudinal pull between the ends o~ the
encompassed tubing section 75, but not so long that the
encompassed tubing section will not bend sharply enough in the
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24
middle for occlusion. I~ too long or too short, the
encompassed tubing section will simply make a gentle loop, or
~orm a simple arc, respectively, under the pull o~ the shank
portion o~ the pinch valve element. Providing the elastic
yield strength of the shank portion o~ the pinch valve element
is greater than the bend resistance o~ the ~lexible tubing,
the encompassed section o~ the ~lexible tubing will be bent
over to the point o~ occlusion when the ~lexible tubing is not
under tension, but will allow the passage o~ ~luid while
longitudinal unkinking tension is being applied.
Re~erring now to Figs. 3 and 4, the pinch valve element
80 is installed on a length o~ ~lexible tubing 49 with the
tubular end portions 82, 83 spaced apart a distance "C" along
the flexible tubing 49 whereas the shank portion 84 assumes a
length very close to "D" when not under tension, the length
"D" being su~iciently shorter than the length "C" to bend
over and pinch the tubing shut when not under su~ficient
tension to stretch the shank portion 84. As an example, with a
~lexible silicone rubber tubing o~ 0.33 cm. (0.131 inch) inner
diameter, 0.51 cm. (0.199 inch) outer diameter and a wall
thickness o~ about 0.086 cm. (0.034 inch), and with a pinch
valve 80 element die cut ~rom the same type o~ tubing having
the inner edges o:E the tubular end portions 82, 83 spaced
apart by a shank portion about 0.51 cm. (0.199 inch) in length
when not under tension, that is to say when unstretched, the
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inner edges o~ the tubular end portions 82, 83 should be
separated by a distance of about 2.0 cm. (0.80 inch) when
installed telescopically on the length of flexible tubing 49,
in order to obtain a desired tightness of pinching or kinking
to block fluid flow. For a given elastically flexible tubing,
the dimensions are very important to obtain the desired valve
action with good opening and sufficiently positive shut o~f.
The length of the encompassed tubing section 75 between the
tubular segment end portions of the pinch valve element is
especially important to get su~icient doubling over for a
sharp bend, but not so much as to ~orm a looser loop. This can
be determined empirically by trial and error for a given size
flexible tubing made of a material with a given modulus o~
elasticity.
As indicated, an important use o~ the pinch valve of the
invention is as a precaution against unregulated flow o~
enteral or parenteral ~luid in the event of accidental or
unintended dismounting of a fluid delivery set from a rotary
peristaltic pump. For example, as shown in Fig. 5, a liquid
enteral nutritional fluid is being drawn ~rom a hanging supply
cont~;n~ 91 into a ~luid delivery set 42 mounted on the
housing 41 o~ a peristaltic pump and delivered to a ~eeding
tube 69 that extends through a gastrostomy 70 into the stomach
74 of a patient.
The pinch valve element 80 seen in Figs. 6 and 7 has been
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26
assembled with a length o~ ~lexible tubing 49 forming part o~
a fluid delivery set 42 usable with a rotary peristaltic pump
as shown in Figs. 5, 8 and 9. A :Eirst length o~ ~lexible
tubing 39 o~ the ~luid delivery set is connectable to or
integral with a supply container 91 and a third length o~
~lexible tubing 64 of the :Eluid delivery set is connectable to
or integral with a device ~or delivery of ~luid into the body
o~ a patient. A second length o~ ~lexible tubing 49 extends
between the outlet of a drip chamber 43 and a
retention/connector element 56 that ~it into respective
supporting retentive receptacles or recesses, 44,55 in the
pump housing 41. Intermediately, the length o~ ~lexible tubing
49 extends around the peristaltic rotor 52 o~ a peristaltic
pump, the section 75, o~ the length o~ tubing 49 o~ which
assembly with a pinch valve element 80 forms a pinch valve,
being on the downstream side o~ the peristaltic rotor 52 when
the ~luid delivery set 42 is mounted on the pump housing 41.
Pre~erably, the ~irst and third lengths o~ tubing 39, 64 are
made of polyvinyl chloride (PVC) and the second length o~
tubing 49 is made of an elastically flexible silicone rubber.
The flexible tubing 49 of the fluid delivery set 42 is
not under tension prior to mounting on a pump housing such
that, as depicted in Fig. 6, the shank portion 84 o~ the pinch
valve element 80 pulls the respective tubular segment end
portions 82,83 close enough together that the section 75 of
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the flexible tubing 49 encompassed between the tubular segment
end portions is doubled over and pinched or kinked to the
point of occlusion of the lumen de~ined by the tubing wall.
The length o~ ~lexible tubing 49 of the ~luid delivery set 42
is depicted in Fig. 7 as it would appear when the ~luid
delivery set is mounted on a pump housing and the length o~
flexible tubing which extends between the drip chamber 43 and
the retention/connector element 56 and intermediately is
stretched around the peristaltic rotor 52 of the peristaltic
pump. Consequently, the tension on the ~lexible tubing 49
stretches the shank 84 o~ the pinch valve element enough to
straighten out the pinched section 75 o~ the ~lexible tubing
49 sufficiently that the pinch valve is opened ~or fluid to
move therethrough. Put another way, the lumen in the ~lexible
tubing is opened or closed in response to the amount o~
tension on the tubing.
The pinch valve o~ the invention is use~ul also as a part
o~ ~luid delivery sets fitting on rotary peristaltic pumps
with housings o~ various con~igurations, such as the prior art
pump depicted in Fig. 10. The pinch valve in the ~luid
delivery set 42p mounted on pump housing 41p as seen in Fig.
10 is under sufficient tension to stretch the shank portion
84p of the pinch valve element so that the pinch valve is open
to fluid ~low. The pinch valve o~ the invention is also
use~ul in many other settings in which ~luid is to be
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- 28
delivered through a ~lexible tubing, including in-line
peristaltic pumps, where there is a need ~or automatic means
~or halting ~luid ~low in the event an essential con~iguration
o~ the ~lexible tubing should become somehow altered.
In Fig. 12 there is shown an alternative pinch valve
element 80a having a substantially rectangular substantially
planar shank portion 84a connecting substantially rectangular
substantially planar end portions 82a,83a. The end portions
82a,83a each have a concave sur~ace adapted to ~it
con~ormingly against the outer cylindrical sur~ace o~ the
~lexible tubing 49 and are bonded or cemented thereto, as seen
in Fig. 11, a~ter ben~ing the ~lexible tubing section 75 so
that attachment can be made with the length o~ the shank
portion 84a much shorter than the length of encompassed
~lexible tubing section 75 in the resulting pinch valve.
In Fig. 14 there is seen another alternative pinch valve
element 8Ob that is shaped like the capital letter "I" and
~ormed o~ a ~lat, sheet-like, elastic, flexible, polymeric
material. The pinch valve element 8Ob is attached to the
flexible tubing 49 by wrapping the wider sheet-like end
portions 82b,83b substantially around the ~lexible tubing and
bonding or cementing them thereto as seen in Fig. 13 at
locations spaced ~urther apart longitudinally o~ the ~lexible
tubing 49 than the length o~ the shank portion 84b whereby the
~lexible tubing section 75 between the end portions 82b,83b is
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doubled over and pinched shut as shown in Fig. 13 when the
~lexible tubing 49 is not under longitudinal tension.
Yet another alternative pinch valve element 80c is seen
in Fig. 16 in which a shank portion 84c having an arcuate
cross section of hal~-cylinder or hemi-cylindrical shape joins
arcuate end portions 82c,83c that are arcuately slotted on the
concave sur~ace that is mated with the cylindrical outer
sur~ace o~ the ~lexible tubing 49 as shown in Fig. 16A. As in
the case o~ the other pinch valve embodiments depicted herein,
the ~lexible tubing 49 is bent during the assembly o~ the
pinch valve seen in Fig. 15 so that the encompassed section 75
o~ the ~lexible tubing will be much longer than the shank
portion 84c o~ the pinch valve element. Thermal bonding or
cementing o~ the pinch valve element end portions 82c,83c to
the ~lexible tubing 49 completes the manu~acture o~ the pinch
valve shown in Fig. 15.
Still another alternative pinch valve element 80d is
shown in Fig. 18 in which a shank portion 84d and end portions
82d,83d are all part o~ one hemi-cylindrical sleeve-shaped
piece o~ elastically ~lexible polymeric material which is
shown in Fig. 17 attached, ~or example by bonding or an
adhesive, to ~lexible tubing 49 to ~orm another embodiment o~
the pinch valve o~ the invention. Again, in bonding or
cementing the shank portion 84d to the ~lexible tubing 49, the
tubing section 75 is bent sharply so that the end portions
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82d,83d of the pinch valve element will be attached at
locations longitudinally spaced along the ~lexible tubing 49
such that tubing section 75 will be substantially longer than
shank portion 84d to provide the tension responsive valve
e~~ect.
Another embodiment o~ a pinch valve element 80e is
depicted partly, and also entirely, assembled with a length o~
~1exible tubing in Figs. 19-21. Pinch valve element 80e
comprises foreshortened tubular segment end portions 82e,83e
joined by a strip or rod-like shank portion 84e. The end
portion 82e is initially insert molded to the ~1exible tubing
49, as is positioning collar 60 which is spaced apart ~rom the
end portion 82e by the intended length o~ encompassed ~lexible
tubing section 75. The section 75 o~ the ~lexible tubing 49
between the tubular segment end portion 82e and positioning
collar 60 is then bent sharply and tubular segment end portion
83e is slipped over the adjacent end o~ ~lexible tubing 49
until the end portion 83e is against the positioning collar 60
where the tubular segment end portion 83e is bonded or
cemented in place, thus forming the pinch valve depicted in
Fig. 20. As shown in Fig. 21, when the tubing 49 is placed
under su~icient longitudinal tension, shank portion 84e
yields and encompassed ~lexible tubing section 75 straightens
out su~~iciently that ~luid may ~low therethrough.
Re~erring now to Figs. 22-24, another embodiment o~ a
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pinch valve element 80~ is seen having closed loop or eye-like
end portions 82~,83f joined by a narrower shank portion 84~.
An end portion 82~ o~ the pinch valve element is emplaced
telescopically around the flexible tubing 49 a selected
distance ~rom an end thereo~ and the ~lexible tubing is then
bent sharply between the position o~ the end portion o~ the
pinch valve element 82~ and the nearest end o~ the flexible
tubing and the other end portion 83~ is telescopically
emplaced around the ~lexible tubing to a position de~ining
~lexible tubing section 75 and the end portions are bonded or
cemented in place. For example a room temperature vulcanizing
silicone polymer composition may serve as a suitable adhesive
to be inserted along or just under the margins o~ the pinch
valve element end portions. The completed pinch valve is
tension responsive, kinking shut when not under tension as
seen in ~ig. 23 and being openable under su~icient tension as
depicted in Fig. 24.
Re~erring now to Fig. 25, still another ~orm o~ tension
responsive pinch valve is made by molding a sharply bent piece
o~ a highly elastic springy material, such as metallic spring
wire 181, or a suitable springy polymeric material, in the
wall 182 o~ a length o~ ~lexible tubing. The memory o~ the
sharply bent springy material causes the ~lexible tubing to be
pinched shut when there is not enough longitudinal tension
applied to the ~lexible tubing. As seen in section in Fig. 26,
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the wall 182 o~ the tubing is made thicker along a
longitudinal side to accommodate the molding or extruding o~
the high elastic springy material 181 therewith.
Alternatively, a sharply bent piece o~ a highly elastic
springy material, such as a spring wire 181, or a suitable
polymeric material, may also be molded onto the outside o~ the
wall 183 o~ the ~lexible tubing as indicated in section view
in Fig. 26A.
Utilizing another mode o~ action a tension responsive
pinch valve is made using a springy pinch valve element that
is pre-~ormed with a memory that causes the ends o~ the valve
element to twist su~iciently to close the lumen o~ a ~lexible
tubing telescopically embraced by the valve element. Such a
pinch valve element is identified by the re~erence numeral 80g
in Fig. 27 where the pinch valve element, having tubular
segment end portions 82g,83g and a shank, in the ~orm o~ a
plurality o~ longitll~;n~l ribs 84g that are helically twisted,
connecting the end portions, is shown assembled telescopically
on a length of a length o~ ~lexible tubing. During assembly,
the pinch valve element 80g is placed under longitudinal
tension to straighten the longitudinal ribs 84g while the
length o~ ~lexible tubing 49 is inserted through the pinch
valve element and bonded or adhesively attached while the
longitudinal tension on the pinch valve element 80g is
maintained. On relaxing the longitudinal tension on the
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assembled pinch valve, the pinch valve element 80g twists the
encompassed section of the flexible tubing, pinching it shut.
Under tension, the resulting pinch valve untwists to unpinch
the flexible tubing, permitting fluid passage therethrough.
It is thus evident that many embodiments of the pinch
valve element employed in the tension responsive pinch valve
of the invention may be made in many different forms from
elastically flexible polymeric material and shaped to have two
end portions connected by a shank portion. The end portions
must be attachable to the flexible tubing of which the pinch
valve is formed and must be attached with the end portions
spaced apart a greater linear distance along the flexible
tubing than the length of the unstretched shank portion of the
pinch valve element, a relative distance in the range of about
4:1, varying only slightly as will at once be apparent,
according to the elastic yield strength of the shank portion
of the pinch valve element and the bend strength modulus o~
the flexible tubing, so that the encompassed tubing section
will be pinched or kinked sharply enough by the pull of the
shank portion when the pinch valve is not under tension that
shut-off or occlusion of fluid flow through the flexible
tubing will take place.
In all embodiments the shank portion must deform
elastically under appropriate tension for the sett-ing in which
the valve is used that the pinch valve will open under
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3 4
longitudinal tension applied to the flexible tubing for the
operations or procedures being carried out, yet close when the
tension is released or absent.
A tension responsive pinch valve of the type shown in
Figs. 1-10 has been assembled by emplacing the pinch valve
element upon a length of tubing using the assembly apparatus
disclosed herein which has utility for placing a flexible, and
at least somewhat elastic, foreshortened tubular segment
telescopically upon and near an end of a length of tubing
having an outer diameter substantially the same or greater
than the inner diameter of the tubular segment. A very
important aspect of the assembly apparatus disclosed herein is
the capacity to eject the assembled combination of a flexible
tubular segment and a length of tubing from the assembly
apparatus without displacing the flexible tubular segment
longitudinally along the length of tubing.
For the purposes o~ the specification and claims it
should be understood that the front side or surface, also
referred to herein as a first surface, of the assembly
apparatus is the side or sur~ace into which the length of
tubing is inserted for emplacement of a flexible tubular
segment thereon, while the back or rear side or surface is
opposite the front side or sur~ace. A forward motion is a
motion towards the ~ront side or surface as here de~ined,
while a rearward motion or extension is taken in the opposite
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direction.
As seen in the exemplary embodiment shown in Figs. 28-30,
and the view in section in Fig. 32, along with the exploded
view in Fig. 33, the present assembly apparatus is made up of
a body portion, indicated generally by the reference numeral
341; which may if desired have a base support portion 342,
which may be secured to a base plate 343, for example by bolts
403, if desired, ~or stability during use. It is to be
understood that the support structure may take any suitable
shape and orientation and the parts thereo~ attached together
by any suitable means such as welding or clamping.
As seen in Fig. 33, the exemplary assembly apparatus
consists mainly of the body portion and suitable base or
support portions, in addition to a sub-assembly, indicated
generally by the re~erence numeral 330, a cover plate 347, a
first retainer ring 352, a control ring 357, a second retainer
ring 366 and a rear support element 374. In the assembled
apparatus the sub-assembly 330 having controllably spreadable
and retractable spreader finger portions is positioned in a
cylindrical bore 344 that extends through the body portion 341
from the ~irst, or ~ront, face to the second, or rear, face
and the other components are attached in the sequence and
positions indicated, using screws and bolts 402, 405, 406,
407, 408 or other suitable fastening means.
The combination o~ the sub-assembly 330 with spreader
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finger elements 339, as seen in exploded view in Fig. 37,
together with the cover plate 347 and the control ring 357,
when mounted in the body portion 341 comprises a mechanical
m~nc ~or assembling a tubular segment with a length o~
tubing. Moreover an integral part o~ the sub-assembly
positioned concentrically and reciprocably within the
mechanical means ~or assembly constitutes means ~or ejecting
an assembly o~ a tubular segment with a length o~ tubing as
will be ~urther described herein.
The means for assembly which includes mechanical means
~or spreading and retracting the spreader ~inger element 339
is described in detail below and is comprised primarily o~:
(1) a substantially cylindrical rotatable sleeve 149, that is
rotatable in the cylindrical bore 344 o~ the body portion 341
o~ the apparatus; (2) a control ring 357 ~or rotating the
rotatable sleeve 149i (3) a disc-like member 354 having
radially, i.e., spirally, extending spiral guideways 360
~ormed therethrough and being mounted co-axially upon a ~irst
end o~ the rotatable sleeve 149 in an annular recess; and (4)
at least three spreader ~inger elements, indicated generally
by the numeral 339, that are supported by a combination of the
disc-like member 354 and the cover plate 347 and radially
spread or retracted by co-action o~ the disc-like member and
the cover plate with the spreader ~inger elements.
The ejector means comprise: (1) a reciprocable piston
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362, depicted in Figs. 36 and 37 as part of the assembly
apparatus shown in differing stages of the assembly process;
(2) an ejector block 368 or 368a as depicted in Figs. 34 and
35; and (3) ejector arms 371, in addition to the rotatable
sleeve 149 in the cylindrical passageway of which the piston
362 is reciprocable.
The subassembly identified by reference character 330 in
Figs. 33, 37, 39 and 40, includes the substantially
cylindrical rotatable sleeve 149 with a cylindrical passageway
extending therethrough and into which there is positioned co-
axially the reciprocable piston, indicated generally by the
numeral 362. The reciprocable piston has a recess in one end
into which there is positioned co-axially an ejector block
such as ejector block 368 or 368a depicted in Figs. 34 and 35.
The ejector block has a plurality, in this example three,
longitudinal slots 370 therein and in which are pivotally
mounted, using pins 371b, ejector arms 371 substantially
parallel to the longitudinal axis of the piston 362, bearing
in mind that when the assembly apparatus is fully assembled,
the piston is co-axial with the bore 344 through the body
portion 341.
In a recess in the first end 365 of the piston 362 there
is mounted in any suitable manner an ejector block 368, such
as the ejector block shown in Fig. 34. The ejector block
shown in Fig. 34 has a rearwardly extending tongue-like
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portion 338 that fits into a complementary borehole or
passageway 336 in the piston 362 and is secured by a setscrew
337. The overall longitudinal length of the ejector block
used in the assembly apparatus determines the distance from
the end of the length of tubing where the tubular segment will
be emplaced during the assembly process.
In assembling a pinch valve element with two tubular
segments as end portions it is necessary to assemble each
tubular end portion with a given length of~ tubing in a
separate operation in which an assembly apparatus is used with
an ejector block having the appropriate length. Thus a
shorter ejector block such as that shown in Fig. 34 would be
used to emplace the first tubular segment, e.g. 82, while a
longer ejector block 368a, as shown in Fig. 35, would be used
in assembling the second tubular segment, e.g. 83, with the
length of tubing to get the proper positioning of the tubular
segments and achieving also the proper spacing longitudinally
along the flexible tubing between the tubular segments. The
ejector block 368a is provided with a forwardly projecting
axial extension 338b that has a large enough cross-section to
serve as a stop for the length of tubing, but is small enough
to facilitate use of a coil spring 363 to make the piston 362
recoil after the ejection step.
In assembling the present apparatus the subassembly 330
seen in Fig. 33 is made up by selecting an ejector block 368
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39
(or alternatively ejector block 368a of Fig. 35) of suitable
dimensions, such as the ejector block depicted in Fig. 34, and
positioning a plurality of pivotal ejector arms 371 in
respective slots 370 formed in the sides of the ejector block
368 where the ejector arms are pivotally retained by pins 371b
that pass through the walls of the slots and through the
ejector arms near a first end 333 of each arm. The number of
ejector arms 371 and complementary slots 370 employed is
preferably at least three to match the number of spreader
finger elements 339. The ejector arms 371 are oriented
substantially parallel to the axis of the ejector piston 362.
The rearward projecting tongue-like portion 338 of the ejector
block 368 is inserted into the axial borehole 336 in the end
365 of the piston 362 and secured with a set screw as shown in
Fig. 32.
Re~erring now to Figs. 32 and 37, an elongated central
guide rod 369 is inserted into and secured in any suitable
manner in a longitudinal axial borehole 334 in the free end o~
the ejector block 368, or, in a longitudinal axial borehole
334a of the axial extension 338b of ejector block 368a if the
longer extension block is part of the subassembly.
Turning again to Figs. 36 and 37, an elastic annular
member 372, which may be a conventional "O"-ring, is placed
around the ejector arms 371 at about mid-length, for example
at notches 335 in the arms, to retain them clustered together
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around the spreader finger portions 358 in the ~inal assembly.
Adjacent the second end 332 o~ each o~ the ejector arms
371 is an elongated longitudinally extending slot 373 ~ormed
therethrough. Through each o~ the slots 373 a respective leg
portion 356 o~ a spreader ~inger element 339 extends radially
outward ~rom the line o~ the axis o~ the piston 362. As seen
in Figs. 37, 38 and 40, the spreader ~inger elements 39 are
"L"-shaped, each with a leg portion 356 and a thin ~inger,
i.e., ~inger portion, 358. To accommodate reciprocal movement
lG o~ the ejector arms 371 along the axial line during an
ejection step without inter~ering with the normal ~unction o~
the spreader ~inger elements 339, the leg portion 356a that
joins the ~inger portion 358 to the leg portion 356 in each
element is pre~erably made thin enough so that the sides o~
the slot 373 do not bind against the leg portion 356a.
The means ~or assembling a tubular segment telescopically
upon a length o~ tubing ~orm part o~ the subassembly 330,
which includes the spreader ~inger elements 339. The
mechanical means ~or radially spreading the spreader ~inger
portions include the disc-like member 354 as well as the
rotatable sleeve 149 on which the disc-like member 354 is
mounted. The cover plate 347 with its radial channels 355,
while not part o~ the subassembly 330, is also an essential
part o~ the mechanical means ~or spreading and retracting the
spreader ~inger portions in cooperation with the disc-like
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member 354 and its spiral guideways 360.
As best seen in Fig. 38, each spreader finger element 339
is provided with a guide pin 359 that extends laterally from
about mid-length o~ the leg portion 356 so as to extend into a
spiral guideway 360 of the immediately adjacent disc-like
member 354. With the spreader finger elements 339 restricted
by the radial channels 355 of the cover plate 347 so that they
cannot rotate, rotation of the disc-like member 354 provides
cam-like action as the guide pins 359 are forced to slide
along the respective spiral guideways 360, moving the spreader
finger elements 339, and their finger portions 358, radially
outward or inward, depending on the direction of rotation.
In further assembling the subassembly 330 o~ Fig. 33, as
seen in Fig. 39, a coil spring 363 is slid over the cluster of
ejector arms 371, followed by the disc-like member 354
preparatory to attaching it as by threaded ~asteners 401 to
the annular end ~ace of the rotatable sleeve 149, a~ter
sliding the piston 362 further into the passageway o~ the
rotatable sleeve 149, as seen in Fig. 40. Also seen in Fig.
40 are the spreader finger elements 339 positioned with the
~inger portions 358 clustered concentrically inside the
cluster of ejector arms 371 and around the central guide rod
369.
The subassembly 330 seen in Fig. 33 and largely contained
within the rotatable sleeve 149 can now be inserted into the
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42
body portion 341 from the first or ~ront side 345 thereof into
the bore 344 and partially extending beyond the second or rear
side 346 of the body portion 341 and positioned as seen in
Fig. 32, so that the cover plate 347 can be attached by
threaded fasteners 402, preferably using a locating pin 404 to
align the grooves in the back side o~ the cover plate
(described below) in the required operative orientation. The
inside face, i.e. the back side, of~ the cover plate 347, as
seen in Fig. 41, is formed with radial channels 355 in which
the respective leg portions 356 of the spreader finger
elements 339 are reciprocable when positioned therein with the
cover plate attached with the inside face turned face to face
with the disc-like member 354. The radial channels 355 formed
in the inside face of the cover plate 347 and with the leg
portions of spreader finger elements therein are, of
necessity, open toward the disc-like member 354 so that the
guide pins 359 can extend into, and slide along, the spiral
guideways 360.
Ref~erring again more particularly to Figs. 32 and 33, the
body portion 341 is seen to encompass the cylindrical bore
344, which is o~ relatively large diameter compared to the
body portion, and extends from the first surface or side 345
to the second surface or side 346 of the body portion. While
the assembly apparatus is shown in the drawing ~igures
supported upon a base with the assembly apparatus oriented to
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receive an end portion of the length of tubing disposed
substantially horizontally during the assembly procedure, it
is to be understood that the base may be modified, if desired,
to support the apparatus with the bore tilted upwardly at any
angle to receive the length of tubing, including ~acing
substantially vertically upward, without departing from the
scope of the invention. In such event the first or front side
of the apparatus as here described would be the upper or top
side or surface and the second or back or rear side would be
the lower or bottom side or surface of the assembly apparatus.
The first surface 345 of the body portion 341 is
substantially covered by the circular cover plate 347 with an
aperture 347a located at the center thereof, while the second
surface 346 of the body portion 341 is faced with a first
retainer ring 352 that has a slightly smaller inner diameter
than the diameter o~ the cylindrical bore 344. The cover
plate 347 and the first retainer ring 352 are fastened to the
body portion 341, ~or example, by screws 402, 405,
respectively but it is to be understood that any suitable
means o~ ret~;n;ng these components in their relative operable
positions may be employed.
As best shown in Figs. 32 and 33, within the cylindrical
bore 344, as indicated above, is a rotatable substantially
cylindrical sleeve or tube 149, having a ~irst end 350 and a
second, smaller, end 351. The rotatable sleeve 149 is
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retained in the cylindrical bore 344 by a flange or shoulder
353 of the rotatable sleeve which mates with, or fits against,
the radially inner portion o~ the first retainer ring 352 in
the vicinity of the second surface 346 of the body portion 341
and a radially outer, forwardly projecting, flange portion
350a of the first end of the rotatable sleeve is retained by
the cover plate 347. While the first end portion 350 o~ the
rotatable sleeve 149 has a larger outer diameter than the
second end portion 351, hence the flange or shoulder 353, the
inside diameter of the cylindrical passageway through the
rotatable sleeve is uniform, and the rotatable sleeve will be
referred to herein as substantially cylindrical. The second
end 351 of the rotatable sleeve 149 is disposed outside of the
cylindrical bore 344 and the first retainer ring 352 and is
concentrically surrounded by a rotatable control ring 357,
preferably of slightly greater diameter than the first
retainer ring 352 and preferably having a knurled perimeter
surface and/or a lever 361 extending therefrom ~or easy
manipulation. The control ring 357 is bolted or otherwise
attached in any suitable manner to the rotatable sleeve 149.
The first end 350 of the rotatable sleeve 149 has a
recessed annular end face, having a perimeter flange 350a, as
indicated. In the annular recess radially inward from the
flange 350a is fitted the disc-like member 354 that is bolted
or otherwise fixedly attached to the end face and has a
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- 45
central aperture 354a the same diameter as the central
aperture 347a of the cover plate 347, but slightly smaller
than the inner diameter of the passageway through the
rotatable sleeve 149. The rotatable disc-like member 354 has
one ~ace contacting the face o~ the annular recessed end of
the rotatable sleeve 149 to which it is attached and the
opposing face is face to face with and rotatable against the
inside face of the front cover plate 347, which is attached to
the body portion 341 and not rotatable.
As seen in Figs. 48 and 50 in dotted outline and in
perspective in Fig. 41, the reverse side o~ the cover plate
347 is provided with three equiangularly-spaced channels 355
which are open sided towards the disc-like member 354 and
extend radially outwardly from the central aperture 347a o~
the cover plate. Inserted reciprocably in each radially
extending channel 355 ~rom the central aperture 347a is a leg
portion 356 of an "L"-shaped spreader ~inger element indicated
generally by the re~erence numeral 339. The spreader ~inger
portions 358 extend out of the central aperture 347a o~ the
~ront cover plate 347 substantially parallel to the axis of
the bore 344 to form a cluster and it is this cluster that is
manipulated radially apart to spread a tubular segment, such
as a tubular segment end portion o~ a pinch valve element, to
permit telescopic assembly thereo~ upon, i.e., concentrically
A 25 with, a length of tubing. The spreader ~inger portions 358,
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46
upon which tubular segments are placed for spreading, i.e.,
stretching to a larger cross-sectional opening, during
telescopic assembly of a flexible tubular segment with a
length of tubing according to the invention, are preferably
quite thin for easier removal of the assembled tubular segment
and tubing combination from the assembly apparatus. In this
regard it should be noted that the spreader finger portions
358 are sandwiched between a tubular segment end portion 382,
383 of the pinch valve element and the tubing 349 when the
spreader finger portions are retracted prior to the ejection
step.
In Figs. 37, 39 and 40, the disc-like member 354 is shown
to have formed therein three parallel and radially, i.e.
spirally, outward extending spiral guideways 360 which are
open-sided towards the cover plate 347. Each spiral guideway
extends spirally out in the same direction of rotation from
the central aperture 354a of the disc-like member 354. Each
leg portion 356 of a respective "L"-shaped spreader finger
element 339 is provided with a guide pin 359 fixedly attached
thereto that extends laterally from the radial channel 355 of
the cover plate 347, in which the leg portion 356
reciprocates, into one of the spiral guideways 360 along which
it is slidable. Instead of the spiral guideways shown cut
entirely through the disc-like member 354, the guideways 360
may be grooves cut to the same pattern if they are each deep
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enough to readily receive and slidably guide a guide pin 359
during rotation of the disc-like member 354 and the grooves
are open sided towards the cover plate 347.
Upon rotation of the disc-like member 354, using the
knurled control ring 357 or the lever 361 to rotate the
rotatable sleeve 14g to which the disc-like member 354 is
attached, cam-like action is obtained to radially spread or
retract the spreader finger portions 358 away ~rom or towards
the common axis as the leg portions 356 are moved radially by
the respective guide pins 359 sliding in the spiral grooves
360. If desired, the lever 361 may be attached to the control
ring 357 as seen in Figs. 29 and Fig. 33 used to rotate the
control ring 357 through a sufficient arc to obtain the
desired spreading and retracting of the spreader finger
portions 35 8.
Positioned in the cylindrical passageway of the rotatable
sleeve 149 and extending rearwardly therefrom is the
reciprocable piston 3 62 that reciprocates through a short
range of movement within the cylindrical passageway of the
rotatable sleeve 149 to carry out the very important ejection
procedure. The piston 362 is urged resiliently out of the
passageway of the rotatable sleeve 149 by the coil spring 363
that bears at one end of the coil spring against the annular
portion of the face o~ the disc-like member 354 that extends
radially inward somewhat from the central aperture o~ the
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rotatable sleeve 149, and at the other end, against the ~irst
end 365 of the piston 362. The rear portion 364 of the second
end of the piston 362 is of a slightly smaller diameter than
the first portion 365, the rear end of the larger diameter
portion constituting a shoulder on the piston, and a second
retainer ring 366 attached to the control ring 357 has a
central aperture smaller enough than the larger diameter of
the first portion 365 of the piston to catch the shoulder and
limit the reciprocation o~ the piston 362 in the rearward
direction.
Mounted in a recess in the face of the ~irst end 365 of
the piston 362 is an ejector block 368 that is ~;m~n.cioned
longitudinally to serve as a stop to accurately limit the
depth of insertion of a length of tubing on which a tubular
segment, such as a pinch valve element, is to be emplaced.
In Figs. 53 and 54 there is shown an assembly apparatus
with an ejector block 368a with a longer axial dimension that
provides a shallower stop for tubing inserted into the
apparatus for the purpose of assem~bling the second tubular
segment end portion of a pinch valve element as a second step
in the process of assembling a pinch valve.
A central guide rod 369 extends axially ~rom the ejector
block 368 or 368a through the passageway of the rotatable
sleeve 149 and substantially to the outward ends of the
spreader finger portions 358 where it is centered between
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49
them. It serves as a guide over which the length of flexible
tubing is inserted into the assembly apparatus. Also pivotably
mounted are ejector arms 371 that extend forwardly along
inside the passageway of the rotatable sleeve 149 and nearly
parallel to the common axis and out through the aperture 354a
in the disc-like member 354 and aperture 347a in the cover
plate 347 where they each rest against the radially outward
surface of a spreader finger portion 358, being collectively
resiliently urged against respective spreader ~ingers by a
springy resilient annular member 372, such as an "O" ring. The
ejector arms 371 must be selected to be of the appropriate
length to contact and bear against the edge of a flexible
tubular segment, such as a tubular end portion of a pinch
valve element, that has just been emplaced on a length of
flexible tubing extending into the apparatus, simultaneously
with contact and pressure between the ejector block and the
inner end of the flexible tubing within the apparatus, in
order to avoid moving or displacing the tubular end portion
longitudinally of the flexible tubing during ejection.
Because of the elastic radially inward tension of the tubular
segment end portions of the pinch valve element upon the
flexible tubing, which has an outer diameter as great or
greater than the inner diameter of the tubular segments, it is
not practically feasible to remove the assembled pinch valve
from the spreader ~ingers portion without risking altering of
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the positions of the tubular segment end portions of the pinch
valve element, unless use is made of the ejection components
of the apparatus.
The second end or part 364 of the reciprocable ejection
S piston 362 is shown in Figs. 29 and 32 to be supported by a
support element 374 having a lower section 375 thereof
attached to the rear of the base portion 342 of the assembly
apparatus and an upright leg portion 376 extending upwardly to
contact the rear part 364 of the piston which is slidable on
the flanged upper end 377 of the leg portion 376. A section
378 of the underside of the rear part 364 o~ the piston 362 is
ground flat from adjacent the second end to the larger
diameter forward part 365 of the piston 362, and it is this
flat section that rests upon the flanged upper end 377 of the
leg portion 376 of the support element 374. The flat nature of
the underside section 378 serves to prevent the piston 362
from rotating during use, and the shoulders 378a, 378b formed
at each end of the flat section 378 catch, respectively, on
the flanged upper end 377 of the support element 374 and on
the second ret~;n~ ring 366 to provide respective stop
actions in the reciprocal motion of the piston 362.
In manufacturing a tension responsive pinch valve of the
sort defined herein, it is essential to the proper valving
action of the pinch valve that the tubular segment end
portions of the pinch valve element be positioned with some
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accuracy spaced apart a rather short interval longitudinally,
i.e., linearly, of the length o~ tubing, with the magnitude of
the interval or spacing being substantially greater than the
length of the shank of the pinch valve element. Such larger
spacing linearly along the tubing is essential in order to
obtain a doubling over of the tubing that produces a pinching
shut of the embraced portion of the tubing when there is no
tension on the portion of the length of tubing that includes
the pinch valve ~er se and the shank of the pinch valve
element tends to elastically assume about its normal length,
drawing the attached tubular segment end portions mutually
closer. Proper spacing during telescopic assembly is readily
achievable in a convenient, efficient way using two nearly
identical embodiments of the assembly apparatus described
herein differing primarily in having ejector blocks of
dif~ering appropriate lengths to assemble the respective
tubular segments. The ejector blocks serve as stops in
indexing the length, or extent, the end of the length of
tubing can extend into the assembly apparatus during the
assembly process, thus controlling the positioning of the
tubular segment end portions.
The first embodiment of the assembly apparatus utilized
will have a relatively short ejector block, such as that
identified by the reference numeral 368 in Figs. 32 and 36 and
shown in perspective view in Fig. 34, so that the end of the
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52
length of tubing will extend relatively deeper into the
assembly apparatus and the :Eirst tubular segment end portion
o~ the pinch valve element will be emplaced far enough from
the inserted end of the f~lexible tubing to leave room ~or the
necessary spacing between the ~irst and the second tubular
segment end portions. The telescopic assembly of the second
tubular segment end portion can only be performed closer to
the inserted end of the length of tubing, using the assembly
apparatus, than the location o~ the emplacement o:E the ~irst
tubular segment end portion.
The second embodiment o~ the assembly apparatus used to
telescopically assemble the second tubular segment end portion
must have a longer ejector block such as that identi:f~ied by
the re~erence numeral 368a in Figs 53 and 54 and shown in
perspective view in Fig. 35, so that the ~lexible tubing will
be stopped at a shallower depth i~or the assembly of the second
pinch valve tubular segment end portion closer to the end oi~
the length of flexible tubing than the :Eirst tubular segment
end portion. The ejector block 368a may be seen in Fig. 35 to
have a smaller diameter extension 338b that serves as the
actual stop within the assembly apparatus for the end of the
length of tubing inserted during assembly operations. The
extension 338b has a smaller diameter than the ejector block
368a in order to leave circumferential annular space within
the rotatable sleeve 149 for the coil spring 363.
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The base, body portion, and parts such as the cylindrical
sleeve, reciprocable piston, control ring and both retainer
rings, cover plate and disc-like member, o~ the assembly
apparatus may be made of mild steel or o~ an easily ma~;n~hle
metal, such as aluminum alloy, if desired, but are preferably
made o~ tool steel or stainless steel. Pre~erably the spreader
~ingers and the ejector arms are made of tool steel or
stainless steel to provide greater strength and durability in
the thinner members.
Re~erring now to Fig. 42 there is depicted an embodiment
of the assembly apparatus, along with a ~lexible pinch valve
element 80 and a length 49 o~ ~lexible tubing of the same
diameter depicted in exploded view. The pinch valve element
80, which consists o~ ~irst 82 and second 83 ~oreshortened
tubular segments as end portions joined by a short shank
portion 84 o~ about the same length as the end portions, is
about to be telescopically assembled on the length 49 o~
~lexible tubing near an end thereo~. The embodiment o~ the
assembly apparatus shown in Fig. 42 is to be understood to be
equipped with an ejector block 68 o~ appropriate length ~or
positioning the first tubular segment 82 o~ the pinch valve
element 80.
The pinch valve element 80 is seen in Fig. 43 to be
poised ~or assembly on the length 49 o~ ~lexible tubing with
the shank portion 84 o~ the pinch valve element bent aside to
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hold the second tubular segment end portion 83 out o~ the way
so the ~irst tubular segment end portion 82 can be slipped
over the spreader ~inger portions 358 that are retracted close
together as a cluster as depicted in Fig. 43. In Fig. 44 the
first tubular segment end portion 82 is shown slipped onto the
cluster of spreader finger portions 358. The inner edge o~
the first tubular segment end portion should be in contact
with the ends 337a o~ the ejector arms 331 to ensure accurate
positioning during the assembly process. The section view in
Fig. 45 also shows the tubular segment end portion 82 slipped
onto the spreader finger portions 358. In Fig. 45 it is also
seen that the apparatus is equipped with a ~airly short
ejector block 368 inside the first end of the ejector piston
362.
Rotation o~ the control ring 357, which concentrically
surrounds and is attached to the rear end of the larger
diameter portion o~ the rotatable sleeve 149, causes rotation
of the rotatable sleeve as well as the disc-like member 354
which is mounted on the ~ront end 350 o~ the rotatable sleeve.
Rotation o~ the disc-like member 354 ~orces the guide pins 359
attached to respective leg portions 356 o~ spreader ~inger
elements 339 to slide along the spiral guideways 360 o~ the
disc-like member, giving cam-like action moving the leg
portions 356 in a radial direction within the radial channels
in the cover plate 347 and the spreader ~inger portions 358 o~
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the spreader finger elements 339 are conse~uently moved
radially as well, which is the desired action. The direction
and extent of rotation of the disc-like member 354 determines
the radial direction and extent of movement of the spreader
finger portions 358.
In the next assembly step the control ring 357 is then
grasped and rotated manually, or the lever 361 may be used to
rotate the control ring 357, in the appropriate direction and
through an arc su~icient to spread the spreader finger
portions 358, thus stretching the first tubular segment end
portion 82 open as shown in Figs. 46, 47 and 48. Turning the
control ring 357 sufficiently stretches the tubular segment 82
enough to admit the end of the length of tubing 49 which is
then slid through the tubular segment with little or no
friction and onto central guide rod 369 until the end of the
length of tubing hits the ejector block 368, which serves as a
stop for the proper positioning of the tubular segment end
portion 82 on the length o~ tubing 49.
The control ring 357 is then rotated as by moving the
lever 361 back towards its starting position to relax the
spreading tension on the first tubular segment end portion 82,
completing the assembly step for the first tubular segment end
portion.
To carry out ejection, the ejector piston 362 is moved
forward (towards the first sur~ace 345 of the body portion
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341) by any suitable means against the coil spring 363 to move
the ejector piston a small distance or spacing ~rom a position
with the second or rear end 364 extending back beyond the
support element 374 until the ejector piston 362 reaches a
pre-set stop as seen in Fig. 49 where the rear edge 378a of
the ~lattened lower sur~ace 378 o~ the rear part 364 of the
piston is caught by the upstanding ~langed upper end 377 of
the upright leg section 376 o~ support element 374. The piston
362 carries ~orward the ejector block 368 and the ejector arms
371 which contact and eject simultaneously and respectively
the end of the length o~ tubing 49, and the nearest edge of
the emplaced tubular segment 82 which is contacted by the ends
of the ejector arms 371a, as can be seen in Figs. 49 and 50.
At the pre-set stop the ejector arms 371 and the ejector block
368 will have coordinately mechanically ejected with
simultaneous pressure the length 49 of flexible tubing and the
em.placed first tubular end portion 82 of the pinch valve
element.
While the piston 362 is readily slid ~orward mAnllAlly
towards the cover plate 347 if the coil spring 363 is selected
to be o~ a suitable spring tension, the piston 362 may be
e~uipped to be reciprocated hydraulically or
electromagnetically, i~ desired.
In Fig. 51 the partly assembled pinch valve depicted in
Fig. 49 is shown poised to be ~urther assembled using a second
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- 57
embodiment o~ the assembly apparatus with a dif~erent, i.e.,
shallower depth stop, in the ~orm o~ a longer ejector block
368a with an extension 338b. The short end section 85 o~ the
length 349 o~ ~lexible tubing between the leading end thereo~
and the emplaced first tubular segment end portion 82 o~ the
pinch valve element 80 has been bent out o~ the way so as not
to impede sliding the second tubular segment end portion 83
onto the retracted spreader ~inger portions 358 of the
assembly apparatus until the tubular segment end portion
contacts the ends o~ the ejector arms 71a, the shank portion
84 o~ the pinch valve element 80 being much shorter than the
section o~ tubing 85a disposed between tubular segment end
portions 82 and 83 which are assembled therewith (i.e.
emplaced thereon).
The second tubular segment end portion 83 o~ the pinch
valve element is then slid onto the spreader ~inger portions
358 and the control ring 357 is rotated to spread the spreader
~inger portions 358 and stretch the second tubular segment end
portion 83 of the pinch valve element 80, similar to what is
seen in Fig. 46, and the short end section 85 o~ the length 49
o~ ~lexible tubing is bent over sharply and the leading end is
slipped inside the spreader ~inger portions 358 and the
stretched second tubular segment end portion 83 and over the
central guide rod 369 and up against the ejector block 368a as
shown in Figs. 52 and 53.
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As indicated, the longer ejector block 368a, having an
extension 338b, provides a stop at a shallower depth of
penetration by the end of the length of tubing 49 inside the
apparatus. The ejector block 368a is selected to have an
extension 338b of appropriate length to provide indexing at a
selected depth of penetration desired ~or the end of the
length o~ tubing 49 in order to achieve proper placement of
the second tubular segment end portion 83.
To complete the assembly of the second tubular segment
end portion 83 of the pinch valve element, the control ring
357 is rotated back to retract the spreader finger portions
358 closer together to relieve the tension on the second
tubular segment end portion 83 as shown in Fig. 54. To carry
out ejection substantially in the same manner as described for
the ~irst emplaced tubular segment end portion 82, the
ejection piston 362 is pressed forward against the action of
the coil spring 363 until the rear edge 378a of the flat lower
surface 378 of the rear portion 364 of the ejection piston 362
is stopped by the flanged upper end 377 of the upright leg
portion 376 of support element 374, whereupon the length 49 of
flexible tubing and the second tubular segment end portion 83
o~ the pinch valve element emplaced thereon will be found to
have been ejected as a unit and the manu~acture o~ the
flexible pinch valve is completed.
It is preferred to complete the manufacture o~ the pinch
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valve by inserting a small amount of an adhesive such as a
room temperature vulcanizing silicone adhesive along the
margins of the tubular segment end portions of the valve
element.
