Note: Descriptions are shown in the official language in which they were submitted.
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
1
Hose for a Piston-Chamber Combination
TECHNICAL FIELD
A piston-chamber combination comprising an elongate chamber which is bounded
by an
inner chamber wall, and comprising a piston in said chamber to be engagingly
movable
relative to said chamber wall at least between a first position and a second
position of the
chamber,
said chamber having cross-sections of different cross-sectional areas and
differing
circumferential lengths at the first and second positions, and at least
substantially
continuously different cross-sectional areas and circumferential lengths at
intermediate
positions between the first and second positions, the cross-sectional area and
circumferential
length at said second position being smaller than the cross-sectional area and
circumferential
length at said first 'position, said chamber is comprising an exit valve,
which is
communicating with a hose, which is communicating with a valve between the
other end of
said hose and an object to be inflated.
BACKGROUND OF THE INVENTION
This invention deals with solutions for optimal pumping conditions, for piston-
chamber combinations of any kind, but specifcially when the main part of the
wall of the
chamber is not parallel to the centre axis of said chamber.
An expansion room is normally used for e.g. high pressure bicycle pumps, in
order
to make a kind of balance between the bigger flow rate of the pump in relation
to the smaller
volume of the tyre to be inflated. Said expansion room is a cavity where its
inlet is
communicating with the exit of the chamber of a pump, through a valve. The
exit of said
expansion room may be directly communicating with a hose, which is connected
to the valve
of the object to be inflated, such as a tyre.
However, when a low pressure tyre is to be inflated, there is already a
balance,
because the tyre valve is opening quite early, in relation to the time it
takes to finalize a
pumping stroke. Thus, it is unnessary, and when a universal bicycle pump is
used, such an
expansion room is to be omittet.
OBJECT OF THE INVENTION
The object is to provide an optimalisation of the functionning of any kind of
a
combination of a piston and a chamber, and in particular as a pump.
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
2
SUMMARY OF THE INVENTION
In the first aspect, the invention relates to a combination of a piston and a
chamber, wherein:
said chamber is comprising an outlet valve, which is communicating with a
hose, which is
communicating with an object to be inflated, which is comprising an inlet
valve, the size of
the volume of said hose between said valves is variable.
Any type of chamber for a pump may be used in combination with a hose,
including elongate
longitudinal chambers, with different cross-sectional area's, and differing or
equal
circumferences between a first and second position of said chamber(s), wherein
a first position
has the biggest cross-sectional area, and a second longitudinal position the
smallest in a
transversal cross-section of said chamber, as disclosed e.g. in EP1179140B1.
The initial volume of a hose my be defined by the size of the cylinder (length
of said cylinder
1 5 and radius of the cross-sectional area in a transversal cross-section)
when produced, thus
unpressurized. The hose may also have various different radii between a lst
and 2' chamber
position, as produced.
Of course may it also be possible that the hose is comprising one of both
above mentioned
valves.
In a second aspect the invention relates to a combination of a piston and a
chamber, wherein
the hose may change its volume by expansion.
When a pressure source, e.g. said chamber is comprising an outlet valve
communicating with
a first end of said hose, and said hose is communicating with an object to be
inflated at its
other end, and said inlet valve is closed, said size of the volume of said
hose may increase,
when fluid is entered from said outlet valve. Depending on the type of
reinforcement, as e.g.
1. windings around the cavity of the hose, may the hose
- not change its volume, when the angle between the tangent of a
reinforcement winding and
the centre line of the hose (= so-called braid angle) is 54 44'.
- change its length, when said angle is bigger than 54 44'.
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
3
Changing the length of a hose (in longitudinal direction), may be an
innovative feature, but in
practise possibly less attractive, due to its odd behaviour.
2. at least a part of the hose may comprising an inflatable container type
piston, which may
have a shape of a cylinder, as produced, and which may be equipped with a
reinforcement
which normally is used in a container type piston of which the shape is
changing toward
the shape of an ellipsoide, or even a sphere, thus, a changing of a radius of
a transversal
cross-sectional area. Such a piston is described below.
EP 1 179140 B1 shows an inflatable container piston type, while EP 1 384 004
B1 shows that
this piston type should have an unstresed production size wherein its
circumference at the
second longitudinal position of an elongate chamber, should have a
circumference which is
approximately the same as the one of the chamber, so as to avoid that the
piston is jamming
when moving from a first to a second longitudinal position.
The piston is expanding when moved from a second to a first longitudinal
position. EP 1 384
004 B1 shows that a reinforcement for such a desired behaviour may be a layer
where the
reinforcement strengs are laying parallel besides each other in an unstressed
production model,
and these strengs are connecting the two end parts, of which one is mounted on
the piston rod,
while the other ican glide of the piston rod - the rubber is directly
vulcanized on both ends.
The reinforcemnet layer is the inner layer, while another, thicker layer than
the layer with
reeinforcement strengs, is protechting said reinforcement layer. Both layers
are being
vulcanized on each other, and at the end parts, there may be another extra
layer on top of the
two. The function of the second layer is additionally to avoid that the
reinforcement strengs
are 'sticking' out of the outer layer, thereby making a sealingly contact with
the wall of the
chamber impossible - however, for an engagingly contact is this just fine.
Hacving the second
layer on top of the reinforcement layer is working fine in practise, and it
has shown be
possible to expand near the 330%, e.g. in a chamber of a pump (please see WO
2008/025391)
where the max. force on the piston rod is constant, from an 017 mm (20d
longitudinal position)
to an 0 59 mm (1' longitudinal position). With two reinforcment layers on top
of each other
with a very small angle for overlapping each other, and on top the above
mentioned 'second'
layer makes the container more strong, but expansions possible are much less
330%.
The types of rubber of the layers rubber may be different, but should be
compatibel so, that
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
4
these can be vulcanized on each other, without getting lose from each other
under normal
working conditions.
It was observed that when the ellipsoide shaped container type piston was
expanding
completely to its sphere shape, the chance of breaking apart was very present -
that is why the
design may be changed so that the length of the piston as unstressed
production model be
increased, by keeping the other variables, such as the chamber design
unchanged - thus, the
sphere shape may not be reached and neither an expansion to 330%, only an
ellipsoide which
has almost become the shape of a sphere - this makes the piston reliable, even
with one layer
with reinforcements.
The shape of the container in an unstressed production state may also be that
the wall of the
container is not parallel with the centre axis, but parallel to the wall of
the chamber because
the wall of the chamber at a second longitudinal position is not parallel to
the centre axis. Just
the wall of the chamber is free of the wall of the container in said
unstressed production state.
1 5 Also an inflatable sphere piston may be used as a temporary expansion
vessel, and such a
piston has been described in e.g. EP1179140B1 and EP 1384004B1.
In a third aspect, the invention relates to to a combination of a piston and a
chamber,
wherein:
said exit is communicating with a hose, the hose is comprising a check valve.
The hose may comprise a build in check valve. This may be classic ball check
valve inside a
cylinder, which is mounted in the hose - the pressure of the inner wall of the
hose keeps the
check valve in place. This may also be a hose, which is expandable on a small
length, so that
unstressed the channel inside the wall of the hose is closed, and while
stressed is open.
In a fourth aspect, the invention relates to a combination of a piston and a
chamber, wherein:
said expandable expansion chamber is expanding from a certain pre-destinated
pressure inside
said hose, and is imploding by decreasing pressure rates.
The expansion of e.g. a part of the hose may enable the creation of a
temporary expansion
vessel. Temporary, because it is only created when there is a flow from the
chamber, while
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
the valve nearest the object to be inflated still is closed. When said hose is
disconnected
from the valve belonging to the valve of the object to be inflated, and there
is a direct
communication to the atmosphere, the internal pressure in said hose may
decrease rapidly,
and by that, the expanded wall of the hose may implode, resultimg again in a
cylinder
5 shaped hose. And depending on e.g. the stiffness of the flexible material
of the hose, and
the number of layers of reinforcement, and the angle in between said laywers,
this
temporary expansion vessel may be created firstly when a certain pressure
level has been
created. This is e.g. important for the efficiency of pumping with a universal
bicycle pump,
with which low (low pressure, relatively high volume) and high pressure tyres
(high
1 0 pressure, low volume) may be inflated.
And, the stroke volume of a pump with an expansion vessel, e.g. as part of the
chamber at a
second longitudinal position, may be less that that of a pump which is using
the bottom part
as part of the stroke volume, while using an expandsion vessel as part of the
hose.
1 5 In order to optimize the pumping speed, the hose of a bicycle pump may
be expandable upon a
certain pressure, so that an expansion vessel is created there. That means
that the pump is
pumping very efficiently at low pressures, where the hose is not creating an
expansion vessel
- such a pressure vessel creates more volume to the volume of the tyre alone,
to be pumped.
Most of the pumping is done for low pressure tyres.
In a fifth aspect, the invention relates to a combination of a piston and a
chamber, wherein:
said expandable expansion vessel or chamber is comprising an stopper for
maximizing the
expansion of the wall of said hose.
The expansion of the hose may be limited by a reinforcement of the hose, and
the expansion
may be done only on a part of the hose. Additionally, there may be a stopper,
e.g. a metal
wire, postioned in the channel of said hose, said wire as been vulcanized to
two parts of the
wall inside said piston, there where the radius in a transversal cross-section
is biggest - when
a maximum expansion has been reached, may the wire a be a straight line.
Said hose may be used besides in pumps, additionally in actuators, shock
absorbers and
motors.
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
6
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, preferred embodiments of the invention will be described
with reference to
the drawings wherein:
Fig. 1 shows a longitudinal cross-section of a conical shaped elongate chamber
showing an expansion chamber as continuation of said chamber.
Fig. 1.1 shows a scaled up detail of Fig. 1.
Fig. 2 shows an inflatable container type piston at an ultimate second chamber
position where the inner wall of the chamber shown in Fig. 1 is parallel to
the
centre axis.
Fig. 3 shows an elongate chamber with a foam piston type (scematically drawn)
with
a nipple as exit, which is connected to a hose.
Fig. 4 shows the chamber of Fig. 3, which has additionally a part in between
the
1 5 the chamber and the exit - an inflatable piston as a part of
the hose is shown
as expansion chamber.
Fig. 4.1 shows a scaled up detail of Fig. 4.
Fig. 5 shows the container type piston at the begin and end of a
stroke, in a
chamber
where the force on the piston rod is constant.
Fig. 6 shows a longitudinal view and cross-sections of the ends of a container
type
piston, as produced.
Fig. 6.1 shows the details of the top end of the container type piston of Fig.
6.
Fig. 6.2 shows the details of the bottom end of the container type piston of
Fig. 6.
DESCRIPTION OF PREFERRED EMBODIMENTS
Fig. 1 shows a bottom part of a chamber of an advanced bicycle floor pump,
where
additionally the bottom part of the chamber is shown. A flexible manchet 42
assembles the
chamber 1 on the foot 41. The hose 43, which is connected to the exit 44 of
the pressure
expansion vessel 49 - this exit is without a check valve. The (schematically
drawn) piston 45
is comprising a piston rod 46. At the bottom of the piston rod is a check
valve 47 positioned,
which is communicating with the external atmosphere (48), and is opening
towards the
= chamber 1, so as to fill the chamber 1 when the piston 45 is moving from
a second
longitudinal position to a first longitudinal position. An expansion pressure
vessel 49 with a
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
7
chamber 56 is shown, comprising an inlet check valve 50, when open, the
chamber 1 is
communicating with the hose 43, through an exit 44. The cross-section of the
external wall 51
of the expansion pressure vessel 49, with an inner wall 52. The expansion
pressure vessel 49
is assembled between a top end 53 and a bottom end 54 of said vessel 49. The
top end 57 of
the expansion pressure vessel 49 is sealed to the wall of the chamber 1 by an
0-ring 55, while
the top end 57 and the bottom end 54 are sealed to the wall 52 of the
expansion pressure
vessel 49 by gas sealing thread 58 and 59 respectively.
This is a preferred embodiment for very high pressures (e.g. 16 Bar), and when
the piston has
difficulties in sealing to the inner chamber wall at second longtudinal
positions. This
construction avoids the sealing on the transition from a longitudinal cross-
sectional section
with a convex wall to a longitudinal cross-section section with a concave
wall.
Fig. 1.1 shows a scaled up detail of Fig. 1. Please refer to the description
of Fig. 1
for the description of Fig. 1.1
Fig. 2 shows the foot 70 of an advanced floor pump for e.g. tyre inflatio,
wherein
1 5 the chamber of Fig .3 has been used. The flexible manchet 71 keeps the
cone formed chamber
80 of Fig. 3 in place. The inside wall 81 of the chamber 80 is parallel to the
centre axis 85 of
the chamber 80 - the outside wall 72 at the position of the inside wall 81 is
not parallel to the
centre axis 85 of the chamber 80. The inflatable piston 73. The enclosed space
66. The tube
65. The inlet check valve 75. The outlet check valve 76. The hose 77. The
measuring space
78, 79 (inside the hose). The valve connector 67 (not shown). The space 68
inside the valve
connector 67 is also part of the measuring space (not shown).
Fig. 3 shows chamber 100, which is a 10 Bar overpressure chamber of the
chamber 1
of Fig. 1. It's second longitudinal positions end with a commom border 27.
This bottom of this
chamber is screwed on a bottom part 101 which is corresponding the
longitudinal cross-
sectional section 30 of Fig. 1. The thread connecting both parts of the
chamber is gas thread
102, which makes a gas thight connection. In the bottom 103 of chamber part
100 is an exit
104, in which a hose nipple 105 has been screwed. The chamber part 100 is
comprising a
piston 106, which has been schematically drawn. The piston 106 is comprising a
hollow piston
rod 107, which is comprising a check valve 108, which opens the space 109
between the
piston and the bottom 103, and thereby let air in from the atmosphere (48)
into said space 109.
On the hose nipple 105 is a hose 110 assembled with a hose clamp 111. The hose
is at its
other end connected to e.g. a valve connector 67. The hole 112 in hose 110.
Fig. 3.1 shows a scaled up detail of Fig. 3. Please refer to the description
of Fig. 1
for the description of Fig. 3.1.
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
8
Fig. 4 shows a chamber 80. Within said chamber 80 is an inflatable piston 73,
which
has been shown in Fig. 2, and which is tightening against a straight wall 81,
which is parallel
the centre axis 85. Here is also aa construction where the chamber 80 has been
updivided in
two parts 115 and 116. The bottom 117 of chamber part 115 has an exit 104, in
which a hose
nipple 105 has been screwed. On the hose nipple 105 is a hose 118 assembled
with a hose
clamp 119. The hose 118 is at it's other end connected to e.g. a valve
connector 67. Without
internal pressure has the hose 118 no hollow channel 120, due to the
reinforcement (not
shown) of the wall 120 of the hose 118 - with internal pressure will there be
a channel 121.
Further down the hose 118 to side of the valve connector 67, there is an
expandable chamber
123, with a wall 124, comprising reinforcements 125. Said reinforcements 125
are comprising
e.g. more than one layer of e.g. unstretchable reinforment lanes, with a very
small angle of
overlapping each other. This results in that the expansion chamber 123 only
will expand,
when there is a high pressure rate inside the expansion chamber 123 - this
makes inflating
efficient, as otherwise the volume of the expansion chamber also has to be
inflated, every time
1 5 a e.g. a tyre has to be inflated -this is unnessary for low presseure
tyres (e.g. up to 4.5 bar).
The metal wire 126, which is limiting the expansion of the inflatable
container piston (as
expansion chamber). There may be used nipples 127 and 128 (not shown) for
connecting said
piston 123 to the hose .
Fig. 4.1 shows a scaled up detail of Fig. 4. Please refer to the description
of Fig. 4
for the description of Fig. 4.1.
Fig. 5 shows the enlarged container type piston 1400, in a chamber 1401, which
has
a centre axis 1402, at the start and end of a stroke. The chamber is of a type
where the
maximum force on the piston rod is approx. even during the stroke. said
chamber comprising
an inner convex shaped wall near a first longitudinal position, said wall is
updivided by
longitudinal cross-sectional sections creating a common border, a distance
between two
following common borders defines a heigth of an inner wall of said
longitudinal cross-
sectional sections, said heigths are decreasing from a first longitudinal
position to a second
longitudinal position the transversal length of the cross-sectional common
borders is
determined by the maximum work force, which is chosen at least constant for
said common
borders near a second longitudinal position, said chamber may comprising an
inner wall which
is parallel to the centre axis of said chamber at a second longitudinal
position. The shape of
the piston at a second longitudinal position is that of a 'starting'
ellipsolde 1403 after having
been pressurized from a non stressed production model, where the shape is
approximately
cylinder like shaped (see Figs. 3 and 5). The shape of the piston near a first
longitudinal
CA 02917347 2016-01-05
WO 2014/005725 PCT/EP2013/002007
9
position is an ultimate ellipsoide 1404, which is almost a sphere 1405
(dashed). In between
has the piston 1400 the shape of an ellipsoide. The details of an ellipsoide
instead of a sphere
at a first longitudinal position are identical with these of a sphere.
Fig. 6 shows an unstressed produced container type piston 1400, which,
stressed may
have the shape of an ellipsoide or a sphere. At the bottom of the figure the
non-movable cap
1420, with a gland 1421 for a 0-ring(not shown), which tightens on the piston
rod (not
shown). A recess 1422 which is more or less a gland for an 0-ring (not shown),
which
tightens the bottom of the piston 1400 on a bolt (not shown) which locks the
bottom of the
piston rod (not shown), through the hole 1432. On top of the figure the
movable cap 1423,
which is movable on the piston rod (not shown). The gland 1424 for an 0-ring
(not shown),
which makes the piston tight in the top of said piston 1400. Both caps 1420
and 1423 having a
recess 1425 and 1426, respectively, which is used to vulcanize the flexible
wall 1427 of the
container piston 1400 on said cabs 1420 and 1423, respectively. Said wall 1427
is shown in
the figure with two layers: a reinforced layer 1428 and a layer which
functions as a cover
1 5 1429 for the reinforced layer 1428. The dashed lines show a possible
third layer 1430 and
1431, on top of the other layers 1428 and 1429, respectively, which is only
present on the
position where said two layers 1428 and 1429, respectively have been
vulcanized on the cabs
1420 and 1423. The centre axis 1433. The wall 1427 of the piston 1400 is
approximately
parallel with the centre axis 1433. The reinforcement strengs 1440 lie in a
parallel pattern,
parallel to the centre axis 1433. The reinforcement pattern 1441 when there
are two layers.
Please note the small angle between the reinforcement strengs 1440 and 1441.
Fig. 6.1 and Fig. 6.2 show both cabs 1420 and 1423 scaled up, respectively of
Fig.
6. At the outer side the rounded off transition 1434 and 1435, respectively,
from the flexible
wall 1427 to the portions of said wall 1427 which has been vulcanized on the
portions 1425
and 1426 of said cabs 1420 and 1423, respectively. At the inner sides of the
flexible wall
1427, just before said flexible wall 1427 meet the portions 1425 and 1426 of
said cabs 1420
and 1423, respectively is a rounded off transition 1436 and 1437. These
transitions 1436 and
1437 provide a stable transition of the wall, when the piston is being
stressed by inflation.
