U.S. patent application number 11/572863 was filed with the patent office on 2007-08-23 for pump comprising a moving wall and use of a pump of this type.
This patent application is currently assigned to Otto Bock HealthCare IP GmbH & Co. KG. Invention is credited to Ralf Carstens, Martin Hillmann, Luder Mosler.
Application Number | 20070196222 11/572863 |
Document ID | / |
Family ID | 34978706 |
Filed Date | 2007-08-23 |
United States Patent
Application |
20070196222 |
Kind Code |
A1 |
Mosler; Luder ; et
al. |
August 23, 2007 |
Pump comprising a moving wall and use of a pump of this type
Abstract
The invention relates to a pump comprising a wall (3; 21, 22;
31, 32, 33), which forms an enclosed fluid volumetric space (1) and
which can be moved by a first force (F) in a direction resulting in
a decrease in volume and, after a preceding decrease in volumetric
space, can be moved by a second force in a direction resulting in
an increase in volume. The pump also comprises an inlet valve (8),
which communicates with an inlet valve (6), and comprises an outlet
valve (9) in an outlet line (7) of the fluid volumetric space (1).
The inventive pump has a compact design due to the fact that it is
provided in the form of a vacuum pump whose volumetric space can be
decreased by the external first force acting against an elastically
deformable material (2; 21, 22; 33) whose restoring force, after
the external force ceases, generates the second force acting
counter to the generated vacuum.
Inventors: |
Mosler; Luder; (Duderstadt,
DE) ; Hillmann; Martin; (Deutschland, DE) ;
Carstens; Ralf; (Gottingen, DE) |
Correspondence
Address: |
FAEGRE & BENSON LLP;PATENT DOCKETING
2200 WELLS FARGO CENTER
90 SOUTH SEVENTH STREET
MINNEAPOLIS
MN
55402-3901
US
|
Assignee: |
Otto Bock HealthCare IP GmbH &
Co. KG
Max-Nader-Strasse 15
Duderstadt
DE
37115
|
Family ID: |
34978706 |
Appl. No.: |
11/572863 |
Filed: |
June 24, 2005 |
PCT Filed: |
June 24, 2005 |
PCT NO: |
PCT/DE05/01124 |
371 Date: |
January 29, 2007 |
Current U.S.
Class: |
417/472 |
Current CPC
Class: |
A61F 2002/802 20130101;
A61F 2002/742 20130101; F04B 33/00 20130101; F04B 45/02 20130101;
A61F 2002/747 20130101; A61F 2002/748 20130101; F04B 45/04
20130101 |
Class at
Publication: |
417/472 |
International
Class: |
F04B 45/02 20060101
F04B045/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 28, 2004 |
DE |
10 2004 036 669.1 |
Claims
1-21. (canceled)
22. A vacuum pump comprising: a wall configured to form a
closed-off fluid volume, the wall movable by means of a first force
which produces a volume reduction of the fluid volume and, after a
preceding volume reduction, by means of a second force which
produces a volume increase in the fluid volume; and an elastically
deformable material that is compressed by the first force and whose
expansion, after termination of the first force, produces the
second force that acts against the vacuum generated by the
pump.
23. The vacuum pump as claimed in claim 22, wherein the wall
comprises two rigid walls spaced apart and lying opposite one
another, and wherein the elastically deformable material is
arranged in the interspace between the two walls.
24. The vacuum pump as claimed in claim 23, wherein each rigid wall
comprises an inner edge on a side toward the interspace, and
wherein the elastically deformable material comprises a sealing
insert positioned at the inner edges and delimiting the fluid
volume.
25. The vacuum pump as claimed in claim 23, wherein the interspace
between the walls is reducible to zero when the elastically
deformable material is compressed.
26. The vacuum pump as claimed in claim 22, wherein the elastically
deformable material comprises a material which is capable of
throughflow of a fluid and is arranged within the fluid volume.
27. The vacuum pump as claimed in claim 26, wherein the material
capable of throughflow comprises an open-pored foam.
28. The vacuum pump as claimed in claim 26, wherein the material
capable of throughflow fills the fluid volume.
29. The vacuum pump as claimed in claim 22, wherein the wall is
flexible, and wherein the elastically deformable material bears
against the flexible wall.
30. The vacuum pump as claimed in claim 29, wherein the flexible
wall surrounds the elastically deformable material on all
sides.
31. The vacuum pump as claimed in claim 29, further comprising at
least one pressure element bearing against the flexible wall over a
large area.
32. The vacuum pump as claimed in claim 22, wherein the elastically
deformable material is configured to extend over an area, and
wherein the thickness of the elastically deformable material is
small as compared with this area.
33. The vacuum pump as claimed in claim 22, wherein the elastically
deformable material comprises two layers that bear against one
another, each layer including a surface profile that is
complementary of the profile of the other layer, with each layer
positioned so that each profile points toward the other and forms
interspaces therebetween, and wherein the interspaces are reducible
by means of the first force.
34. The vacuum pump as claimed in claim 33, wherein the interspaces
between the two layers are reducible to zero by means of the first
force.
35. The vacuum pump as claimed in claim 22, wherein the elastically
deformable material is formed by the wall itself.
36. The vacuum pump as claimed in claim 22, further comprising at
least one pressure element bearing against the wall over a large
area.
37. The vacuum pump as claimed in claim 22, further comprising: an
inlet port in fluid communication with the fluid volume; an inlet
valve in fluid communication with the inlet port; an outlet port in
fluid communication with the fluid volume; and an outlet valve in
fluid communication with the outlet port.
38. The vacuum pump as claimed in claim 37, wherein the inlet and
outlet valves are each positioned on a side of the wall which
corresponds to the thickness of the pump.
39. The vacuum pump as claimed in claim 37, wherein the inlet and
outlet valves are each arranged on narrow sides of the wall which
lie opposite one another.
40. The vacuum pump as claimed in claim 37, further comprising at
least one pressure element bearing against the wall over a large
area, and wherein the inlet and outlet valves are each arranged in
a recess of one of the pressure elements.
41. The vacuum pump as claimed in claim 40, wherein the inlet and
outlet valves are each arranged in a recess of the same pressure
element.
42. The vacuum pump as claimed in claim 22 in combination with and
as part of a prosthesis for a lower extremity.
43. The vacuum pump as claimed in claim 42, wherein a force occurs
due to body weight when a patient wearing the prosthesis for a
lower extremity treads on a surface, and wherein this body weight
force provides the first force for the pump.
44. The vacuum pump as claimed in claim 42, wherein the vacuum pump
provides vacuum to a prosthesis socket in which a residual limb is
received.
45. The vacuum pump as claimed in claim 22, further comprising a
pressure element bearing against the wall, the pressure element
configured to be positioned within a prosthetic foot with the wall
interposed between the pressure element and a portion of the
prosthetic foot.
46. The vacuum pump as claimed in claim 45, wherein the first force
compressing the elastically deformable material is generated by
action of the prosthetic foot during movement by a patient wearing
a prosthetic device coupled to or including the prosthetic
foot.
47. A system configured to be coupled to a user having a body
weight, the system including forces that arise due to the body
weight of the user, the system comprising: a vacuum pump having a
wall configured to form a closed-off fluid volume, the wall movable
by means of a first force arising within the system which produces
a volume reduction of the fluid volume and, after a preceding
volume reduction, the wall movable by means of a second force which
produces a volume increase in the fluid volume, and an elastically
deformable material that is compressed by the first force and whose
expansion, after termination of the first force, produces the
second force that acts against the vacuum generated by the
pump.
48. The system as claimed in claim 47 further comprising a
prosthesis for a lower extremity, the prosthesis being couplable to
the user and including the vacuum pump, wherein the first force
arises when the user coupled to the prosthesis treads on a surface
exerting body weight onto the prosthesis.
49. The system as claimed in claim 48, wherein the prosthesis
comprises a socket into which a residual limb of the user is
received, and wherein the vacuum pump provides vacuum to the
socket.
50. The system as claimed in claim 48 further comprising a pressure
element bearing against the wall of the vacuum pump and the
prosthesis further comprising a prosthetic foot, wherein the
pressure element is positioned within the prosthetic foot with the
wall interposed between the pressure element and a portion of the
prosthetic foot, such that the first force arises by action of the
prosthetic foot when the user treads on a surface.
51. A method of manufacturing a prosthesis for a lower extremity
that generates vacuum by the application of a user's body weight to
the prosthesis, the method comprising the steps of: providing a
vacuum pump having a wall configured to form a closed-off fluid
volume, the wall movable by means of a first force arising within
the system which produces a volume reduction of the fluid volume
and, after a preceding volume reduction, the wall movable by means
of a second force which produces a volume increase in the fluid
volume, and an elastically deformable material that is compressed
by the first force and whose expansion, after termination of the
first force, produces the second force that acts against the vacuum
generated by the pump; and providing a prosthesis for a lower
extremity which is couplable to a user of the prosthesis, the
prosthesis including the vacuum pump, such that the first force of
the vacuum pump arises when the user coupled to the prosthesis
treads on a surface exerting body weight onto the prosthesis,
thereby resulting in vacuum generated by the vacuum pump as part of
the prosthesis.
52. The method of claim 51, wherein the step of providing the
prosthesis comprises providing a socket included in the prosthesis
into which a residual limb of the user is received, and wherein the
vacuum generated by vacuum pump provides vacuum to the socket.
53. The method of claim 51, wherein the step of providing the
prosthesis comprises providing a pressure element and a prosthetic
foot included as part of the prosthesis, the pressure element
bearing against the wall of the vacuum pump, wherein the pressure
element is positioned within the prosthetic foot with the wall
interposed between the pressure element and a portion of the
prosthetic foot, such that the first force of the vacuum pump
arises by action of the prosthetic foot when the user treads on a
surface.
Description
[0001] The invention relates to a pump comprising a wall which
forms a closed-off fluid volume and which can be moved by means of
a first external force in the direction of a volume reduction and
by means of a second force, after a preceding volume reduction, in
the direction of a volume increase, and with an inlet valve which
communicates with an inlet port and with an outlet valve in an
outlet line in the fluid volume.
[0002] The invention relates, furthermore, to a use of a pump of
this type.
[0003] Pumps of this type are known, for example, as hose pumps, in
which the fluid is expressed from a fluid-filled hose by means of
pressure rollers pressing the hose together and moved in a
longitudinal direction of the hose. As a result of the movement of
the roller, the upstream end of the hose is filled with fluid again
when this end is connected to a fluid supply. The propulsive force
for moving the rollers is generated by a motor which may be
designed, for example, as an electric or hydraulic motor. Pumps of
this type are used for conveying a volume in the pressure
direction.
[0004] Another kind of pump of the type initially mentioned is
diaphragm pumps, in which the fluid volume is reduced by the
diaphragm and moved back and forth by means of a connecting rod and
is subsequently increased again. The connecting rod thus transmits
both the first force for the volume reduction and the second force
for the volume increase.
[0005] In many instances, it is merely necessary to call up a
pumping power only in specific operating states when movements, the
force flux of which can be used for actuating a pump, take place in
a device. Thus, it is known, for example, to evacuate the
interspace between a patient's amputation stump and an airtight
liner arranged above it, in order, by means of the vacuum formed,
to ensure a firm fit of the liner connected to a prosthesis. For
this purpose, a piston pump is used, which, when the patient treads
on the ground by means of the prosthesis, exerts an evacuation
stroke and is returned by means of a return spring. Pumps of this
type are relatively bulky particularly because of the return
mechanism required.
[0006] The object on which the invention is based is, therefore, to
design a pump of the type initially mentioned such that it can be
implemented in a small space.
[0007] To achieve this object, according to the invention, a pump
of the type initially mentioned is characterized in that it is
designed as a vacuum pump, the volume of which can be reduced by
means of the external first force against an elastically deformable
material, the return force of which forms, after the termination of
the external force action, the second force acting counter to the
generated vacuum.
[0008] In the pump according to the invention, the working stroke
by which the fluid, in particular air, is sucked away from a
closed-off volume, is brought about by the return force of the
elastically deformable material. Previous deformation for reducing
the volume of the fluid material takes place by means of a first
force acting externally. The pump according to the invention thus
makes it possible to have a very uncomplicated and small-volume
design, by means of which a low to medium vacuum can be
generated.
[0009] In a first preferred embodiment of the invention, the wall
has two rigid walls lying opposite one another, the elastically
deformable material being arranged in the interspace formed by the
walls. In this case, the elastically deformable material may be
formed by a sealing insert running around the edge and delimiting
the fluid volume. This embodiment affords the advantage that the
external force can act directly on one of the rigid walls.
[0010] In another embodiment likewise having advantages, the wall
is designed flexibly, the elastically deformable material bearing,
preferably over a large area, against the flexible wall, In this
case, a high return force sufficient for many applications can be
generated by means of a relatively thin material layer.
[0011] The elastic material may be an open-pored foam which is
arranged within the fluid volume and which exerts the return force
after a volume reduction has been carried out. The fluid, which is
preferably air, accordingly flows through the foam. In this
embodiment, the generation of the return force does not take up any
additional space at all, since the fluid volume itself is utilized
for this purpose. In this case, it is expedient if the foam
completely fills the fluid volume, with the exception of residual
volumes as a consequence of construction. An alternative elastic
material which is capable of throughflow and which can be used for
the invention is a wide-mesh knitted fabric.
[0012] The pump according to the invention is implemented in a
simple way if the elastic material is surrounded on all sides by
the flexible wall. It is also possible, however, for the wall to be
partially of rigid design and for a part of the wall such as is
required for the volume reduction to be made flexible.
[0013] The pump according to the invention can preferably be
produced with a preferred large-area extent and with a thickness
which is small, as compared with this, and can therefore in many
instances be integrated into the structure of a device without
difficulty.
[0014] To press together the fluid volume, at least one pressure
element bearing against the flexible wall over a large area is
provided. In particular, the fluid volume with a flexible wall may
be arranged between two large-area pressure elements.
[0015] The valves may be arranged on the corresponding narrow sides
of the flexible wall, but are preferably also arranged in recesses
of one of the pressure elements or of both pressure elements, with
the result that flexing actions of the flexible wall are
reduced.
[0016] The pump according to the invention can advantageously be
integrated in the force flux of a system in which forces arise
which are utilized to exert one of the two forces. The pump
according to the invention is suitable particularly as a vacuum
pump.
[0017] In a special application, the pump constitutes part of a
prosthesis for a lower extremity. Preferably, in this case, the
force occurring due to body weight when a patient treads on the
ground is utilized as the first force. The pump may be employed, in
particular, for the vacuum assistance of a suction well of the
prosthesis, in particular for evacuating the interspace between a
liner and the prosthesis shank. A preferred place of use for the
pump according to the invention is an artificial foot which makes
it possible particularly effectively to have the large-area design
of the pump perpendicularly to the force flux occurring during load
caused by the body weight.
[0018] The invention will be explained in more detail below by
means of exemplary embodiments illustrated in the drawing in
which:
[0019] FIG. 1 shows a diagrammatic illustration of a pump in the
initial state according to a first embodiment;
[0020] FIG. 2 shows the pump according to FIG. 1 in the compressed
state;
[0021] FIG. 3 shows a pump in an initial state according to a
second embodiment;
[0022] FIG. 4 shows a pump in a third embodiment which is
integrated into an artificial foot;
[0023] FIG. 5 shows an arrangement of an elastically deformable
material consisting of two layers with profilings which point
toward one another and in the nonloaded state form a fluid
space;
[0024] FIG. 6 shows the arrangement according to FIG. 5 in a loaded
state in which the compressed material of the layer completely
fills the fluid space;
[0025] FIG. 7 shows an embodiment of a pump according to the
invention with two rigid plates lying opposite one another and with
an insert running around at the edge and consisting of an
elastically deformable material, in the nonloaded state;
[0026] FIG. 8 shows the arrangement according to FIG. 7 in the
loaded state.
[0027] The pump illustrated in FIG. 1 has a closed fluid volume 1
which is filled virtually completely with an elastic material in
the form of an open-pored elastic foam 2. The foam 2 has a
substantially large-area extent with a small width. It is
surrounded on all sides by a flexible wall 3 which thus has four
narrow sides and two large-area sides with large dimensioning, as
compared with these. Two large-area pressure elements 4, 5 bear
against the large-area sides.
[0028] The flexible wall 3 has on opposite narrow sides a tubular
or hose-shaped feed 6 and a tubular or hose-shaped outlet 7. Both
the feed 6 and the outlet 7 are provided in each case with a
nonreturn valve 8, 9.
[0029] For the pumping operation, the pressure elements 4, 5 are
moved relatively toward one another, as illustrated in FIG. 2. The
fluid volume 1 together with the foam 2 contained in it is thereby
pressed together, with the result that fluid, preferably air,
escapes via the nonreturn valve 9 and the outlet 7. When the
pressure force of the pressure elements 4, 5 ceases, the elastic
return force of the foam 2 ensures that the fluid volume 1 returns
to the initial state of FIG. 1, fluid being sucked into the fluid
volume 1 via the inlet 6 and the nonreturn valve 8.
[0030] In the modification of the pump, as illustrated in FIG. 3,
the pressure plate 5' is provided with recesses 10 in which the
nonreturn valves 8, 9 are arranged, The flexing actions of the
flexible wall 3 in the region of the nonreturn valves 8, 9 are
thereby markedly reduced.
[0031] FIG. 4 shows an example of the use of a pump of the type
described in FIGS. 1 to 3. The pump is in this case integrated into
an artificial foot 11, the functional set-up of which is connected
to a lower-leg tube 12 of a lower-leg prosthesis. The functional
part of the artificial foot consists of an S-shaped spring insert
13, the free ends of which form an upper junction limb 14 and a
lower sole limb 15. Between these is located an essentially
horizontal intermediate piece 16 which is connected to the junction
limb 14 and to the sole limb 15 in each case by means of a curved
transition piece 17, 18 such that the essentially horizontal
intermediate piece 16 can spring in relation to the sole limb 15 of
the insert 13 under the action of a weight. Under the action of the
weight of the prosthesis wearer when the latter puts his foot onto
the ground, therefore, the distance between the intermediate piece
16 and the sole limb 15 is reduced. This distance reduction is
utilized for the pump employed according to the invention, in that
the intermediate piece 16 is connected to a pressure element 5''.
The pressure element 5'', of large area per se, is adapted in its
form to the form of the intermediate piece 16 and of the curved
transition 17, in order to make it easier to position the pressure
element 5''. The fluid volume 1 filled by the foam 2 is located,
within the flexible wall 3 surrounding the foam 2 on all sides,
between the pressure element 5'' and the sole limb 15 functioning
here as a counterpressure element 4. One of the connections 6, 7 is
indicated merely diagrammatically, said connection extending
through a recess 10 of the pressure element 5'' and being
connectable, for example as an inlet 6, via a hose line to the
interspace between an amputation stump and a liner surrounding the
amputation stump, in order to evacuate this interspace.
[0032] The functioning of the pump inserted into the foot 11
corresponds fully to the functioning explained with reference to
FIGS. 1 to 3. The load on the artificial foot 11 due to the body
weight acts as a pressure force for the pressure element 5'', with
the result that the intermediate piece 16 is pressed downward in
the direction of the sole limb 15 and thus presses together the
fluid volume 1 and the foam 2. Air thereby escapes from the fluid
volume 1. When the artificial foot 11 is relieved, at the latest
when the foot 11 is lifted off from the ground for the next step,
the foam 2 causes the pump to return to the initial position
illustrated in FIG. 4. In this case, air is sucked via the inlet 6
into the fluid volume 1 out of the interspace between the
amputation stump and the surrounding liner, that is to say a
desired vacuum which stabilizes the fit of the liner on the
amputation stump is generated in the interspace.
[0033] It can be seen that an artificial foot 11 is suitable for
integrating the pump according to FIG. 4, because it is easily
possible to have a large-area design of the fluid volume 1 and of
the foam 2 perpendicularly to the (vertical) force flux because the
anatomy of the foot 11 likewise tends to extend over a large area.
It is nevertheless also possible, of course, to arrange a
corresponding pump in other prosthesis parts which execute a
relative movement with respect to one another, for example in a
knee joint.
[0034] FIGS. 5 and 6 show an exemplary embodiment in which the
elastically deformable material is formed by two layers 21, 22
which point toward one another in each case with a profiled surface
23, 24. The profiled surfaces are in this case formed by
projections 25, the width of which is smaller than a recess 26
between the projections 25. The tips 25 of the layer 21 accordingly
project into the recesses 26 of the layer 22, and vice versa, thus
giving rise to the spaces which form the fluid space 1 and which
are not filled by the elastically deformable material.
[0035] If, then, a pressure causing compression is exerted onto
layers 21, 22, the tips 25 are compressed in the height direction
and the material is deflected into width, so that the spaces
between the tips 25 and the recesses 26 are filled, ideally
completely, as illustrated in FIG. 6. When the external force
pressing the layers 21, 22 against one another ceases, the initial
situation of the layers 21, 22, as is illustrated in FIG. 5, is
established. The return causes fluid, in particular air, to be
sucked in from a vacuum space connected to the fluid space 1.
[0036] The layers 21, 22 may be formed from a plastic having
stability such that the layers 21, 22 at the same time form the
wall 3. Alternatively, however, the layers 21, 22 may also
cooperate with pressure plates 4, 5, such as are illustrated in the
embodiments according to FIGS. 1 to 3.
[0037] In the exemplary embodiment illustrated in FIGS. 7 and 8,
the fluid space is delimited by two rigid walls 31, 32 parallel to
one another and by an insert 33 which runs around and connects the
edges of the rigid walls 31, 32 sealingly to one another and which
consists of an elastically deformable material. The insert 33 is in
this case a channel-like profile consisting of a stable fluidtight
material which is connected, fluidtight, to the walls 31, 32 by
adhesive bonding or the like.
[0038] By means of an external first force F, the rigid walls 31,
32 are pressed against one another, as indicated in FIG. 8. The
fluid space 1 is thereby reduced to a maximum, with the result that
the fluid contained in the fluid space 1 escapes through the outlet
7. When the external force F ceases, the state illustrated in FIG.
7 is reestablished due to the return force of the insert 33, with
the result that fluid is sucked into the fluid space 1 via the feed
6.
[0039] It can be seen that the exemplary embodiments illustrated in
FIGS. 5 to 8 can be employed in the same way as the exemplary
embodiments according to FIGS. 1 to 3, that is to say, in
particular, also in an artificial foot or the like,
[0040] The pumps according to the invention may be used, in
particular, in prosthesis parts also for other purposes, for
example as a hydraulic pump for the control of dynamic functions,
for example for the control of hydraulic damping cylinders or for
the movement of structural elements of the prosthesis, for example
from an uncoupled to a coupled state, in order to carry out dynamic
adaption to the situation of use.
* * * * *