Note: Descriptions are shown in the official language in which they were submitted.
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BLIND RIVETING TOOL
Background of the Invention
Field of the Invention
This invention i6 concerned with a blind riveting
tool comprising a housing, an abutment member having a
rivet-engaging face at its forward end to engage the head
of a rivet in a rivet-setting operation, and means
reciprocable within the housing to pull the mandrel stem
relative to the abutment member in the rivet~setting
operation, the abutment member and mandrel-pulling means
each comprising a plurality of rivet-assembly-engaging
parts disposed about a common axis along which the mandrel
will be pulled, which parts can be opened and closed
relative to said axis to allow in their open condition the
introduction therebetween of a mandrel with a pulling head,
and in their closed condition the abutment member to engage
the rivet head and the pulling means to engage the mandrel
under its pulling head, said parts of the abutment member
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and pulling means beiny resiliently urged towards their
open condition and arranged to be closed by the advance of
a surrounding annular actuating element over said parts of
the abutment member.
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Summary of the Prior Art
A blind riveting tool constructed as just referred
to is described in US Patent No. 2400354, for example, the
tool being arranged for manual operation and for hand
feeding, the annular actuating member being also retracted
by hand to a'low the riveting assembly engaging parts of
the abutment member and mandrel-pulling means to open for
introduction of the mandrel of a fresh assembly. Whether
the tool be constructed as described in said U.S. Patent
No. 2400354 with reference to Figures 1-6 (in which the
actuating ~ember is said to be restored to its forward
position by a spring~ or with reference to Figure 7-13,
loading of the tool with a fresh rivet is inconvenient and
slow, the operator having only two hands for what is
essentially a three-handed operation, to hold the tool,
operate the actuating member, and pick-up and insert a
fresh rivet.
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Summary of the Inv_ntion
It is an object of the present invention to
provide a blind~riveting tool for use with blind-rivet
assemblies of the kind having a pulling head on the mandrel
and which has improved means for receiving and engaging the
mandrels of such assemblies.
The foregoing objec~ is achieved in accordance
with the invention in that said actuating element is
mounted in said housing for reciprocation along said common
axis behind a forwardly extending sleeve portion of said
housing, the abutment member and mandrel-pulling means
being also reciprocable along said axis between a rearward
position behind said sleeve portion of the housing where
they can be opened and closed and a forward position in
which rivet-engaging face of the abutment member is exposed
for presentation of a rivet to a workpiece.
Preferably, in a tool in accordance with the
invention, the actuating element is arranged, in the
operation of a tool, to advance along the abutment ~ember
before advance of the abutment member into said forwardly
extending sleeve portion of the housing, so that the
abutment member is kept closed as it passes through said
sleeve portion. Preferably, the forwardly extending sleeve
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portion of the housing has the same internal diameter as
the actuating sleeve~ and the actuating sleeve in the
operat~on of the tool advances to a rear end o said sleeve
portion, so that the abutment member and mandrel-pulling
means are held closed by said sleeve portion when in their
forward, rivtt-setting, positions.
Preferably, in a tool in accordance with the
invention, pneumatic means is provided for advancing and
retracting said actuating sleeve over the abutment member
and for advancing and retracting the abutment member
through said forwardly extending sleeve portion of the
housing, advance of the abutment member being arranged to
occur in the operation of the tool after advance of the
actuating sléeve to close the abutment member. Hydraulic
means may be provided for effecting relative axial
displacement between the mandrel pulling means and abutment
means to sét a rivet.
Preferably also, in a tool in accordance with the
invention, the mandrel~engaging parts of the mandrel-
pulling means are accommodated within and keyed to the
rivet-engaging parts of the abutment member so that they
open and close with opening and closing of the abutment
member and are limited in their axial displacement relative
thereto by the keying means.
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The forwar~ly extending sleeve portion of the
housing of a tool in accordance with the invention may have
a longitudinal slot in its wall through which a blind-rivet
assembly can be introduced to insert the mandrel stem
between the open parts of the abutment member and mandrel-
pulling means when the abutment member i5 in its retracted
position behind said portion of ~he housing. The rivet-
assembly feeding means may be provided on the housing of
the tool to receive a blind-rivet assembly from a hose
along which it is blown and directing it through said slot
in said sleeve portion of the housing and axially into the
open abutment member and mandrel-pulling means.
Furthermore, said feeding means may comprise an arcuate
tubular element mounted to rock about its center of
curvature on an axis lying in a direction at right angles
to that of the reciprocation of the abutment means and so
disposed that in an advanced delivery position said tubular
element projects into said housing through said slot and a
delivery end of said tubular element is in register with
the open abutment means, while the other, inlet, end of the
tubular element is in register with a delivery end of said
hose, and in a retracted position is withdrawn from the
path of the abutment means through said forwardly extending
sleeve portion of the housing. Advance and retraction of
said tubular element may be effected in the operation o
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the tool by said actuating sleeve, and the tool may
comprise rack and pinion means for advancing and retracting
said tubular element, said rack being coupled to said
actuating sleeve by a lost motion connection so that
movement of the tubular element occurs only towards the end
of the forward and rearward strokes of said sleeve.
The abutment member of a tool in accordance with
the invention may comprise a sleeve with a piston at its
rear end slidable in a fluid-pressure cylinder, and the
mandrel-pulling means may also comprise a sleeve projecting
forwardly into that of the abutment member and having a
piston at its rear end slidable in said cylinder behind
that of the abutment member. Fluid passages are provided
in the housing to enable pressurized fluid to act on the
rear of the piston of the mandrel-pulling means to advance
both pistons, and in front of the piston of the abutment
member to retract them both. There is also a fluid passage
through the wall of the mandrel-pulling means adjacent its
piston which thus opens into said cylinder between said
pistons and through which fluid under pressure can be
introduced to separate said pistons while they are at the
front end of said cylinder to effect a rivet-setting stroke
of the mandrel-pulling means in the operation of the tool.
Such a tool may have means to supply air under pressure to
said cylinder in front of the piston of the abutment member
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and behind the piston the mandrel~pulling means, and
means to supply hydraulic fluid to the inside o~ the
sleeve of the mandrel-pulling means for admission to the
cylinclRr between said pistons. A hollow cylindrical rod
or sleeve may ex-tend Eorwardly Erorn an end cap at the
rear end of said cylinder, through an annular seal ln the
piston of the manclrel-pulliny means, and terminate in
an annular seal bearing on the inner surface of the
sleeve of the mandrel-pulling means, hydraulic fluid for
admission to said cylinder between said pistons passing
through the hollow rod from the rear, through a passage
in the wall of the hollow rod just behind its annular
seal, and through the annular chamber bekween said rod
and the last-mentioned sleeve to said passage through the
wall adjacent the piston of the mandrel-pulling means.
In such a case the hollow rod may have a double cylindrical
wall, the hydraulic f]uid Plowing through a space, sealed
at each end, between the walls, the inner wall providing
a passage for the rearward ejection of broken-off mandrel
stems.
According to a ~urther broad aspect of the
present invention, there is provided a blind-riveting tool
which comprises a housing, an abutment member having a
rivet-engaging face at its forward end to engage the head
of a rivet in a rivet-setting operation, and means
reciprocable within the housing to pull the mandrel stem
relat;ive to the abutment member in the rivet-setting
operation. The abutment member and mandrel-pulling means
each comprises a plurality of rivet-assembly-engaging
parts disposed about a common axis along which the mandrel
will be pulled, which part can be opened and closed relative
to said axis to allow in their open condition the intro-
duction therebetween of a mandrel with a pulling head~
and in their closed condition the abutment member to
engage the rivet head and the pu].ling means to engage
the mandrel under its pulling head. These parts of the
abutment member and pulling means are resiliently urged
towards their open condition and arranged to be closed by
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-the advance of a surrounding annular actuatiny element
over the parts of the abutment mernber characterized in
that the actuating element is mounted in the housing for
reciprocation along the common axis behind a forwardly
extending sleeve. portion of the housing. The abutment
member and mandrel-pulling means are also reciprocable
along the said axis between a rearward position behind
the sleeve portion where they can be opened and closed
and a forward position in which the rive~-engaging face
of the abutment member is exposed for presentation of a
rivet to a workpiece.
There now follows a detailed description, to be
read with reference to the accompanying drawings, of a
blind riveting tool in accordance with the invention
~illustrative thereof. It will be.realized that ~his
;illustrative tool has been selected for description by
way of example and not of limitation of the invention.
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Brief Description of the Drawings
In the accompanying drawings:
Figure 1 i5 a view in side elevation and partly in
longitudinal section of the illustrative tool, the tool
having been loaded with a blind-rivet assembly and being
ready for presentation to a workpiece for a blind-riveting
operation;
Figure 2 is fragmentary view partly in radial
section of rivet-assembly engaging parts of an abutment
member and mandrel-pulling means of the illustrative tool
Figure 3 is a view in transverse section on the
line III-III of Figure 2;
Figure 4 is a view in transverse section on the
line IV-IV of Figure S;
Figures 5, 6 and 7 are views similar to Figure 1
but showing parts of ~he illustrative tool at successive
stages in an operating cycle of the tool, these figures
omitting a rear portion of the tool;
Figure 8 is a view, largely in section, of said
rear portion of the illustrative tool showing parts thereof
in positions they occupy in the stages depicted in Figures
6 and 7; and
Figure 9 is a circuit diagram of fluid control
means of the tool.
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Descr~t_on of the Pr_ferred _mbodim~nt
Referring to Figure 1, the illustrative tool
comprises a housing 10 with a rearward extension which
provides a pneumatic/hydraulic cylinder 12, and a front
part which includes a forwardly extending sleeve 14.
Depending from a central body 16 of the housing 10 is a
pistol grip handle 18 (see also Figure 4). The central
body 16 of the housing 10 has an intermediate annular wall
26 separating internal, forward and rearward bores 28, 30
respectively, the bore 30 extending through the cylinder 12
and being much longer than the bore 28.
Mounted for axial reciprocation in the housing 10
is an abutment member 50 (Figure 1) of the illustrative
tooll said member 50 comprising a hollow cylindrical sleeve
52 slidable through an annular seal 54 (Figure S) in the
wall 26 and having at its rear end a hollow piston 56
slidable in the bore 30. Screw threaded into the front end
of the sleeve 52 i5 a nosepiece 58 (Figures 2 and 3) formed
from a hollow steel cylinder having an internal bore which
terminates in a conical internal face 60 of obtuse apical
angle. Externally, the nosepiece terminates in a flat or
hollowed end face 62 for engagement with a rivet head, the
face 62 being surrounded by a frusto conical surface 64.
Through the end wall thus formed extends a hole 66 of a
diameter to accommodate the stem of a mandrel. The
nosepiece 58 is divided by eight slots into eight segments
68 extending far enough rearwardly that being splayed
outwardly and tempered in their manufacture~ they are
constantly urged by their own resilience towards an open
condition in which their tips, which together provide the
end face 62, are wide enough apart to allow the
introduction therebetween of a pulling head of a mandrel.
When closed by squeezing the segments 68 together, the
segments nearly touch each other to provide in effec~ a
continuous annular abutment for the rivet head.
Within the abutment member 50 is a second hollow
piston assembly which constitutes mandrel-pulling means 70
of the illustrative tool. The mandrel-pulling means 70
comprises, at its rear end, a hollow piston 71 (Figures 1
and 5) slidable in the bore 30 of the cylinder 12 behind
the piston 56. The piston 71 is secured to a sleeve 72
slidable through an annular seal in the piston 56. At its
forward end, the sleeve 72 threadedly receives an adaptor
74 which in turn is tapped to receive a screw threaded rear
end portion of a tubular collet 76 (see also Figure 2~.
The collet 76 has resilient fingers 80, similar to the
segments 68 and formed in the same way so as to be
constantly urged apart and against the inner walls of the
segments 68, except that the internal end wall of the
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collet is flat and it has a frusto-conical outer end t7all
complimentary to the face 60 of the nosepiece 58. Thus,
each finger 80 has a rearwardly facing shoulder 82, normal
to the axis of cylinder 12, to engage the underside of the
pulling head of a mandrel ln a rivet-setting operation7
Because the fingers 80 are constantly urged apart
by their own resilience, ~hey open and close in the
operation of the tool with the segments 68.
Axial displacement of the pulling means 70 within
the abutment member 50 is limited by two stepped stop
pieces 86 (Figures 2 and 5) accommodated in diametrically
opposed radial slots in two of the segments 58 of the
abutment member 50. Each stop piece has a projection 90
accommodated in a wide annular groove 92 around the collet
76. The stop pieces 86 are held in their slots by a
resilient band 94.
Opening and closing of the segments 68 of the
nosepiece 58 of the abutment member 50 and, under their
influence, of the fingers 80 of the collet 76 of the
mandrel pulling means is effected in the operation of the
illustrative tool by moving an actuating element in the
form of a sleeve 100 backwards and forwards respectively
over the outer surface of the nosepiece. When the
actuating sleeve 100 is rearward (as in Figure 7), the
segments 68 are free to open, that is to say spread apart,
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under their own resilience, to a greater overall diameter
than that of the cylinder from which they were formed. The
sleeve 100 as an internal diameter which is a sliding fit
over the original diameter of the nosepiece. Consequently,
as the sleeve 100 moves forward over the nosepiece the
segments close together until they nearly touch (in fact,
until the slots separating the segments are parallel
sided), at the same time also squeezing together the
fingers 80 of the collet 76. When open, there is room
be~ween the segments 68 and between the fingers 80, for a
pulling head of a mandrel to be introduced, and when
closed, the segments and fingers closely embrace the
mandrel stem.
Screwed into the forwardly extending sleeve
portion 14 of the housing 10 is a further forwardly
extending sleeve portion 96 of the housing, which has the
same internal diameter as the actuating sleeve 100 and
consequently serves, when the abutment member 50 advances
into it in the operation of the tool, to keep the nosepiece
58 closed.
The actuating sleeve 100 slides in an annular seal
102 in the portion 14 of the housing 10. The sleeve 100
has a flange 104 (which constitutes a piston) at its rear
end. The flange 104 carries an external sealing ring 106
which slides in the forward bore 28 of the housing 10, and
an internal sealing ring 107 which slides over the outer
surace of the sleeve 52 of the abutment member 50.
Rearwardly projecting from the adaptor 74 to
provide a continuous passage therethrough i. a tube 110
which passes freely into a hollow sleeve 112. The sleeve
112 has an enlarged head 114 at its front end, which has
annular seal 115 bearing on the inside wall of the sleeve
72~ The sleeve 112 projects rearwardly through a seal 117
in the piston 71. Most of the length of the sleeve 112,
between two bearing portions 116 (just behind the head 114
in Figure 5) and 118 (Figure 8), is of reduced diameter,
and the bearing portions carry a sleeve 120 so that between
these portions within the sleeve 120 there is an annular
chamber 122, The sleeve 120 has an outer diameter which is
less than the inner diameter of the sleeve 72 so as to
provide an annular chamber 123 therebetween. Communication
between the chambers 122 and 123 is provided for by ports
124 at each end of the sleeve 120 adjacent the bearing
portions 116,118; as will become apparent, the full stroke
of the piston 71 takes place between these portsO The
sleeve 112 at its rearward end is firmly secured to an end
cap 126 mounted on the cylinder 12; the sleeve 112 and head
114 are thus fixed in the housiny 10,
The housing 10 of the illustrative tool is
provided with passages.for oil and air for effecting
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forward and return strokes of the pistons 56,71 and 104.
Thus, in the handle 18 is an inlet 130 through which oil
can flow via a tube 128 to and from the end cap 126. Means
for connecting the inlet 130 to an oil pressure intensifier
is not shown in he dxawings, being of conventional
construction-, From the tube 128 oil is able to flow
through passageways 131 in the end cap 126, through the
port 124 at the rear end of the sleeve 120 into the annular
chamber 122 between the sleeves 112 and 120, and hence
through the port 124 at the front into ~he annular chamber
113 inside the sleeve 72 of the mandrel pulling means 70.
Ports 136 open through the sleeve 72 just in front of the
piston 71, pressurized oil which thus flows through the
ports 136 into the bore 30 of the cylinder 12 is effective
to exert pressure on the pistons 56 and 71 urging them to
separate. Release of oil pressure allows it to flow back
through the system just described.
While the rear of the piston 56 and the front of
the piston 71 are always exposed to oil at the pressure
supplied at the inlet 130, the front of the piston 56 and
the rear of the piston 71 are always exposed to air~ Thus,
air is introduced and expelled to and from the front and
rear of the cylinder 12 through suitable ports 156 (Figure
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5), 158 (Figure 8) and passageways in the housing lO not
fully described herein, b~t following normal practice with
double-acting cylinders.
A cycle of operation of the rivet-setting parts of
the illustrative tool can best be regarded as starting with
the abutment member 50 and mandrel-pulling means 70 in
their forward positions as depicted in Figure l, with a
blind-rivet assembly B comprising a rivet R and a mandrel M
loaded in the closed segments 68 and fingers 80; a blind-
rivet assembly is shown being delivered to the nosepiece in
Figure 7. The nosepiece 58 projects slightly from the
sleeve portion 96 of the housing lO, and is kept closed by
said extension. The segments and fingers closely embrace
the mandrel 10, the shoulders overlapping a pulling head P
of the mandrel, which thus cannot fall out.
Means for controlling the flow of air and
hydraulic fluid to operate parts of the tool in sequence is
depicted diagrammatically in Figure 9. When the tool is at
rest as shown in Figure l, air from a compressed air supply
200 passes through a two-position valve 202 to the rear end
of the cylinder 12 behind the piston 71 and to the bore 28
behind the sleeve 100. The abutment member 50 is thus held
in the housing in its foremost position by air under
pressure in the cylinder 12 behind the piston 71, which
bears on the piston 56, oil pressure at the inlet 130 being
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atmospheric~ Air is also under pressure behind the
actuating sleeve 100.
The tool may now be presented to a workpiece (not
shown), the rivet R inserted into a hole in the workpiece
and the rivet head pushed against the workpiece by the
nosepiece 58. On the hand grip 18 is a push-button switch
of an electr~cal control circuit which, on now being
depressed by the operator, actuates a solenoid valve 206 in
an hydraulic circuit with the result that oil under
pressure from a pressure intensifier 208 is admitted to the
inlet 130 and thence to ~he cylinder 12 between the pistons
56 and 71. At the same time, a valve 202 is actuated to
open immediately a path to exhaust air from behind the
piston 71. The oil forces the pistons 56 and 71 apart,
~hus pulling the mandrel while pushing on the rivet head,
thereby to set the rivet; the mandrel eventually breaks at
a neck within the rivet where the mandrel stem is of
reduced cross-section and the broken-off portion of the
mandrel stem M (which can be seen in Figure 5), unless it
is held by friction between the fingers 80, is ejected
rearwardly along the tube 110 and sleeve 112 to a hose 150
leading to a suitable receptacle. Separation of the
pistons 57 and 71 is limited by the slots 88 and stop
pieces 86. The tool has now assumed the condition shown in
Figure 6. Conveniently, air is arranged to flow gently and
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continuously rea~wardly along the tuber sleeve and hose to
facilitate ejection of the mandrel stem, for example by
reducing the air pressure in the receptacle so as to create
suction through the hose.
Actuation oE the valve 202 also opened ~he bore 28
behind ~he sleeve 100 to exhaust, and pressurized an air
line 210 leading to the front of the cylinder 12. The
piston 56 could not at that time retract, however, because
the pulling means 70 was held forward by the mandrel. But
when the mandrel breaks, the piston 56 moves rearwardly,
pushing back the piston 71. After a time delay pre-set in
the electrical control circuit, the solenoid valve 206 is
de-energized, reversing under spring pressure to allow oil
to flow out of the cylinder 12 from between the pistons
56,71. On reaching the rear end of its stroke, the piston
71 engages a spring-pressed plunger 212 of a valve 214
which permits pressurized air from the line 210 to pass
into the bore 28 in front of the piston 104 to retract the
actuating sleeve 100 and allow the segments 68 of the
nosepiece 58 and the fingers 80 for the mandrel-pulling
means to open (see Figure 7) and the broken-off mandrel
stem, if not released earlier, to be released and ejected
rearwardly of the tool.
As will next be described, in the full operating
cycle of the illustrative tool, a fresh blind-rivet
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assembly is now loaded in~o the nosepiece 58 and fingers
80, the sleeve 100 advanced, b~ reversing the air pressure
in the bore 28, to close the segments 68 and fingers 80,
and the abutment member 50 and mandrel pulling means 70 are
advanced by admission of air to ~he bore 30 behind the
piston 71 to restore the rivet-setting parts to the
condition shown in Figure 1. Advance of the sleeve 100 and
of the pistons 56 and 71 to their forward positions are
effected by reversal of the valve 202 by de-energization of
its solenoid, which occurs at a predetermined time after
pressing the button 148 as set by a time delay in the
electrical control circuit. Advance of the pistons 56,71
is, however, delayed until after the sleeve 100 has
advanced by the interposition in the line to the rear of
the cylinder 12 of a valve 204 which opens the cylinder 12
behind the piston 71 to pressure only after the pressure in
front of the piston 56 has dropped~ The tool is thus
restored to the condition shown in Figure 1 whether or not
the operator has released the button 148, but a second
cycle will not be commenced until he has both released and
again pressed }he button~
Means of the illustrative tool for loading a fresh
rivet assembly into the mandrel-pulling means 70 while the
abutment member 80 is retracted will now be described. The
assembly-feeding arrangement itself is the subject of our
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co-pending Patent Application No. P34 44 025.9.
The sleeve portion 1~ of the ho~sing 10 of the
.illustrative tool has a depending, generally flat sided,
extension 160 (Figures 4,5 and 7), one side 162 integral
with the portion 14, the other serving as a cover 164. The
parts 162 and 164 provide support for a rotatable
transverse pivot pin 166 to which is secured a pinion 168.
The pinion 168 engages a rack 170 longitudinally
reciprocable below the sleeve 100 in a bearing 172 provided
by the housing portion 14. The rack 170 has teeth along
its lower edge in meshed with those of the pinion 168~ A
longitudinal slot 174 extends along a rear part of the
rack, and in the slot 174 rides a pin 176 secured to lug
178 depending from a collar 177 screwed on to the sleeve
lQ0.
Secured to the pinion 168 for to and from arcuate
movement therewith is a bracket 180 to which is fi~ed a
curved tube 182 concentric with the pinion 168. When the
pinion is rocked clockwise to a limit (depicted in Figure
7) imposed by the stroke of the sleeve 100, or by
engagement of a stop face 184 of the bracket 180 with a
stop face 186 of the extension 160, a delivery end of the
tube 182 projects through an aperture 187 in the portion 96
of the housing and is in register with the segments 68 of
the nosepiece 58, being in alignment with, and close to,
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them. Also, with the tube 182 in this delivery ,oosi~ion,
the other, inlet, end of the tube is aligned with a
delivery end of a hose 192 which leads from a supply of
blind-rivet assemblies. Means for releasing assemblies one
at a time with the pulling heads of their mandrels leading
and blowing them along the hose 192 (one is shown in Figure
7) when the tube 182 is in its delivery position so that
one is loaded into the mandrel-pulling means is not further
described here~ The inlet end of the tube 182 and outlet
of the hose 192 have complementary curved opposing ends as
shown in Figure 7 to allow the assemblies to pass from the
hose to the tube across a minimum gap.
When the pinion 168 is rocked anti-clockwise to
its other limit of movement (see Figure 5) imposed by
engagement of stop faces 188 and 190 of the bracket 180 and
the extension 160 respectively, or by the stroke of the
sleeve 100, the delivery end of the tube 182 swings
downwardly out of the path of the abutment member 50, which
as already mentioned is next advanced to render the tool
ready for the next blind-riveting operation.
To ensure timely rocking of the bracket 180 and
tube 182 in the operating cycle of the illustrative tool, a
torsion spring 194 ~Figure 4) acts between the housing
extension 160 and the pin 166 (to which the plnion 168 is
fixed) to urge the bracket 180 clockwise (viewing Figure
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7). The slot and pin connection 174,176 allows lost motion
to occur between the sleeve 100 and rack 170 during a first
part of the advance of the sleeve 100 so that the segments
58 and fingers 80 close to take control over the newly
delivered blind-rivet assembly before the tube 182 moves
away from its delivery position.
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