U.S. patent application number 13/593921 was filed with the patent office on 2013-02-28 for tube accommodation of a roller pump.
This patent application is currently assigned to Aesculap AG. The applicant listed for this patent is Juergen SCHNEIDER, Rolf SCHNEKENBURGER, Erik SCHOENEWERK. Invention is credited to Juergen SCHNEIDER, Rolf SCHNEKENBURGER, Erik SCHOENEWERK.
Application Number | 20130052063 13/593921 |
Document ID | / |
Family ID | 46785236 |
Filed Date | 2013-02-28 |
United States Patent
Application |
20130052063 |
Kind Code |
A1 |
SCHOENEWERK; Erik ; et
al. |
February 28, 2013 |
TUBE ACCOMMODATION OF A ROLLER PUMP
Abstract
A peristaltic pump for medical purposes includes a pump casing
in which a tube accommodation chamber is formed. In one embodiment,
a pump head is rotatably mounted in the tube accommodation chamber.
A tube unit is adapted to be inserted in the tube accommodation
chamber such that a tube of the tube unit is engaged with the pump
head in a manner to at least partially encompass the pump head. For
this purpose, a tensioning device is arranged at the pump casing.
The tensioning device cooperates with the tube unit so as to
tension the tube around the pump head. The tensioning device may
include a lever mechanism, wherein a lever element of the lever
mechanism simultaneously forms or comprises a protective cap for at
least partially covering the tube accommodation.
Inventors: |
SCHOENEWERK; Erik;
(Donaueschingen, DE) ; SCHNEKENBURGER; Rolf;
(Tuttlingen, DE) ; SCHNEIDER; Juergen;
(Tuttlingen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHOENEWERK; Erik
SCHNEKENBURGER; Rolf
SCHNEIDER; Juergen |
Donaueschingen
Tuttlingen
Tuttlingen |
|
DE
DE
DE |
|
|
Assignee: |
Aesculap AG
Tuttlingen
DE
|
Family ID: |
46785236 |
Appl. No.: |
13/593921 |
Filed: |
August 24, 2012 |
Current U.S.
Class: |
417/476 |
Current CPC
Class: |
A61M 5/14232 20130101;
F04B 43/1261 20130101; A61M 1/1012 20140204; A61M 1/1039 20140204;
F04B 43/1284 20130101 |
Class at
Publication: |
417/476 |
International
Class: |
F04B 43/12 20060101
F04B043/12 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 29, 2011 |
DE |
10 2011 081 722.0 |
Claims
1. A peristaltic pump for medical purposes, comprising a pump
casing in which a tube accommodation chamber is formed in which a
pump head is rotatably mounted, and a tube unit adapted to be
inserted or inserted in the tube accommodation chamber such that a
tube of the tube unit is pulled in longitudinal direction and is
engaged with the pump head in a manner to encompass same at least
partially, for which purpose a tensioning device is arranged at the
pump casing or at the tube accommodation chamber, said tensioning
device cooperating with the tube unit or the pump head so as to
tension the tube around the pump head on operation thereof, the
tensioning device comprising a lever mechanism.
2. The peristaltic pump according to claim 1, wherein a lever
element of the lever mechanism simultaneously forms or comprises a
protective cap for at least partially covering the front side of
the tube accommodation chamber.
3. The peristaltic pump according to claim 2, wherein the
protective cap either forms or is that lever element that is
provided as a manual operating element or an operating handle of
the lever mechanism, or forms or is that lever element that is
operable via the operating handle for transferring force to the
tube unit.
4. The peristaltic pump according to claim 3, wherein in case the
operating handle simultaneously forms or comprises the protective
cap, the protective cap has the shape of a cover plate.
5. The peristaltic pump according to claim 3, wherein in case the
force transferring lever element forms or comprises the protective
cap, the operating handle has the shape of a bow-shaped handle, a
buckle/operating button, or a toggle lever.
6. The peristaltic pump according to claim 1, wherein a preferably
beam-shaped tube accommodation that is arranged or adapted to be
arranged either fixed or displaceable in or at the tube
accommodation chamber, and into which the tube is adapted to be
inserted or is inserted via a tube holder formed or fixed
thereon.
7. The peristaltic pump according to claim 6, wherein in the case
of a fixed tube accommodation the lever mechanism acts on the now
displaceable pump head so as to press same, by operating the lever
mechanism, against a loop-shaped tube middle section formed by the
tube accommodation or the tube holder, and to extend the tube
longitudinally in this process.
8. The peristaltic pump according to claim 7, wherein in the case
of a displaceable tube accommodation the lever mechanism acts on
the tube accommodation preferably as a further element of the lever
mechanism so as to move same by operation of the lever mechanism
relative to the now stationary pump head along with the tube holder
such that a loop-shaped tube middle section formed by the tube
accommodation or the tube holder touches the pump head in a manner
encompassing same and is extended in longitudinal direction of the
tube in this process.
9. The peristaltic pump according to claim 1, wherein the lever
mechanism is designed to be self-locking.
10. A peristaltic pump for medical purposes, comprising: a pump
casing in which a tube accommodation chamber is formed in which a
pump head is rotatably mounted; a tube unit provided as an exchange
component and consisting of a flexible tube and a tube holder
adapted to be inserted displaceably in the tube accommodation
chamber and holding the flexible tube at two longitudinally
spaced-apart tube positions, wherein the tube unit is adapted to be
inserted or is inserted in the tube accommodation chamber such that
the tube is pulled in longitudinal direction by displacing the tube
holder and is tensionally engaged with the pump head in a manner to
encompass same at least partially; and a tensioning device in the
form of a lever mechanism which is fixedly arranged at the pump
casing or at the tube accommodation chamber and which comprises at
least one lever element as a protective cap for at least partially
covering the front side of the tube accommodation chamber and which
cooperates with the tube holder for the displacement thereof so as
to pre-tension the tube around the pump head on operation.
11. A tube unit for use with a peristaltic pump having a squeeze
pump construction, the tube unit comprising a tube holder adapted
to hold a flexible tube at two axially spaced-apart positions and
forming at least one undercut adapted to be brought in an undercut
holding engagement with a tube accommodation of the peristaltic
pump or a tube-tensioning lever mechanism of the peristaltic pump.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.119
to German Application Number DE 10 2011 081 722.0, filed Aug. 29,
2011, the content of which is incorporated herein by reference in
its entirety and for all purposes.
FIELD
[0002] The present disclosure relates to a peristaltic pump and in
particular to a tensioning device arranged in or at a tube
accommodation chamber of a peristaltic or roller pump for impacting
tension to a tube adapted to be inserted in the duct, preferably of
disposable construction.
BACKGROUND
[0003] Roller or peristaltic (squeezing) pumps are displacement
pumps in which the medium to be pumped is pressed through a tube by
a flexible outer mechanical deformation thereof. Due to the gentle
advancement of the medium (without it being sheared or distorted),
peristaltic pumps are especially also used for medical
purposes.
[0004] In the casing of a generic peristaltic pump, a
flexibly/elastically deformable tube is on principle inserted such
that it is guided around a rotatable pump head along a
predetermined circumferential section on which a number of rollers
spaced apart at angles are rotatably mounted, said rollers being,
with an appropriate rotation of the pump head, sequentially brought
into rolling engagement with the tube and compress/clamp same. The
tube either supports itself at the outer surface of the pump casing
or is tensioned around and against the pump head with a
predetermined tensile force.
[0005] With any construction, however, the movement of the pump
head results in that the respective clamping position of a roller
that is being in engagement moves forward along the tube and thus
advances the pumping medium inside the tube section immediately in
front of the corresponding roller. The generation of a suction
underpressure in the tube section immediately following the
corresponding roller is, as a rule, effected by the inherent
elasticity of the tube material due to which the tube attempts to
recover its original shape of construction.
[0006] Due to increasingly stricter hygienic provisions and due to
more demanding requests of users, it has become usual to design at
least those components of a peristaltic pump that get into direct
contact with the pumping medium as a disposable, in particular when
used in medicine. This includes primarily the tube which
consequently has to be adapted to be removed and inserted easily.
In prior art, a plurality of tube units and tensioning devices are
known, some of which are indicated in the following.
[0007] There exists the possibility of preassembling the tube and
the pump head in a kind of cartridge as a separate pump unit that,
in the case of a changing process, merely has to be
inserted/latched into the casing of a peristaltic pump such that
the pump head is engaged in a rotation-fixed manner with a drive
shaft, for instance, of an electric motor or a gear mechanism
downstream thereof. Although this solution greatly facilitates the
changing process and simultaneously also ensures high operating
safety since it is possible to design the cartridge as a
self-contained casing unit, so that rotating elements are housed to
be inaccessible from outside, this is a relatively expensive
variant of construction.
[0008] The pump head is a rather complex component consisting of a
plurality of individual parts movable/rotating relative to each
other (as was already indicated before), which in fact would not
have to be changed since it is not contaminated directly by the
pumping medium. It is therefore substantially more cost-efficient
to provide only the tube as a disposable. For changing the tube,
however, it has to be drawn off the pump head or fitted on it
again, respectively, wherein a pre-tensioning force by which the
tube is tensioned around the pump head has to be overcome. To
facilitate the changing of merely the tube (with the pump head
remaining), a specific tensioning mechanism has therefore been
developed by means of which it is possible to release and tension
the tube for a changing process.
[0009] DE 94 11 183 (U1) discloses a simple construction of such
tensioning device. Accordingly, the tube is provided/designed with
two axially spaced-apart bulge-shaped stops/holders, whereas the
pump casing is, inside the tube accommodation chamber molded or
inserted therein, provided with a transverse strip or a beam as a
tube accommodation in which two indentations are formed. In order
to insert the tube in the tube accommodation, one of the
bulge-shaped stops is latched/hooked into one of the indentations
and subsequently the tube is pulled around the pump head. Finally,
the other bulge-shaped stop is latched/hooked into the other
indentation. This insertion process is very time-consuming and
complicated since the stops have to be hooked into the indentations
while the tube is under tension, which requires some skill and
force by an operator.
[0010] Alternatively, it is also possible to provide a catching
beam as a tube accommodation which is, at the two axial ends
thereof, fixedly connected with the tube at two axially
spaced-apart tube sections such that the tube (tube middle section)
forms a loop between the beam ends. The beam and the tube thus form
a separate, exchangeable tube unit.
[0011] The tube formed this way is now placed/guided with its loop
area around the pump head, and the catching beam is latched into a
tensioning device. The tensioning device preferably provides a
guide rail/guide groove for the catching beam along which the
catching beam is displaced while the loop area is tensioned until
the catching beam latches into a detachable holder/latch in the
tube accommodation chamber. Although this construction facilitates
the inserting process of the tube, the tube has to be tensioned in
the region of the loop simultaneously at two ends of the tube area
and hence at two edges forming with respect to the pump head, which
requires stronger force that is not possible to be exerted by every
operator.
[0012] Finally, the changing of merely the tube (and not the pump
head) necessitates free access from outside of the rotating
components, too, said access remaining open also during operation
for cost reasons or being at least partially closable by means of
an additional service/protection cap. The latter does not only
increase the price of the peristaltic pump, but also constitutes a
safety hazard since the cap has to be closed in an additional step,
which may be forgotten.
[0013] In view of these problems, there is a need to provide a
peristaltic pump which has increased functionality. It is desirable
to facilitate the inserting process for a tube or a tube unit
especially of disposable construction. It is also desirable to
improve the safety of the peristaltic pump. Finally, it is
desirable to keep the peristaltic pump, and in particular the
exchange tube unit, cost-efficient.
SUMMARY
[0014] The drawbacks of know peristaltic pumps are resolved in many
respects by peristaltic pumps with features in accordance with the
present disclosure and claims.
[0015] Peristaltic pumps in accordance with this invention may
include a tube accommodation chamber in which the tube may be
inserted while it is almost untensioned. Furthermore, the
peristaltic pump may include a tube tensioning device with a lever
mechanism adapted to be operated preferably by hand or by electric
motor so as to tension the tube along a predetermined
circumferential section around the rotating pump head of the
peristaltic pump.
[0016] The lever mechanism enables the operating force required for
reaching the necessary tensioning force and hence the pressure
force against the pump head to be reduced, so that is can simply be
exerted by hand without additional separate tools being required.
In the case of a motor operation of the lever mechanism, the drive
may be of small dimension and hence cost-efficient.
[0017] A plurality of constructional designs are conceivable as a
lever mechanism, by which an operating movement is transferrable
with an appropriate reduction to the tube/the tube unit, such as,
for instance, a worm gear, a lifting block, a gear mechanism, or
similar auxiliary means. Practically it is, however, advantageous
to design the lever mechanism, in particular in the case of manual
operation, conventionally in the form of an operating element
(operating handle) hingedly mounted to the peristaltic pump and
coupled (operatively connected) with a displaceable component or
plunger component transferring thrust, which transfers an operating
force generated at the operating handle by pivoting as a function
of the kind/place of coupling in a reduced manner to the tube. Such
a concept for the lever mechanism is easy to manufacture, fail-safe
and hence economic.
[0018] In one aspect of the invention, there is provided a medical
peristaltic pump comprising a pump casing in which a tube
accommodation chamber is formed or accommodated in which a pump
head is rotatably mounted, and a tube unit inserted in the tube
accommodation chamber such that a tube of the tube unit is engaged
or is adapted to be engaged with the pump head in a manner to
encompass same at least partially.
[0019] The tensioning force with which the tube touches or is to
touch the pump head is exerted by a tensioning device arranged at
the pump casing (i.e. provided as a fixed component of the
peristaltic pump), said tensioning device cooperating with the tube
unit in order that during its (manual/motor) operation the tube is
tensioned around the pump head. In accordance with the invention,
the tensioning device is a lever mechanism fixedly mounted to the
pump casing and hence not to be considered as a tool.
[0020] Due to this design it is easy for any person to insert and
tension a tube or a tube unit. The removal of a tube or a tube unit
is also easy to perform in that the pre-tension of the tube around
the pump head is released by the lever mechanism and subsequently
the tube/tube unit is removed from the tube accommodation chamber
almost free of force. Since the lever mechanism is a component of
the peristaltic pump, it is not changed each time, so that the
operation of the peristaltic pump remains cost-efficient.
[0021] Preferably, a lever element of the lever mechanism
simultaneously also comprises a protective cap for at least
partially covering the tube accommodation chamber. Thus, on
operating the tensioning device, the tube accommodation chamber is
simultaneously opened and/or closed (automatically), and hence the
movable parts positioned therein, such as the pump head, are
protected toward the outside. This increases the safety of the
peristaltic pump.
[0022] Another aspect of the invention provides, where appropriate,
that the protective cap either forms or is fixed to that lever
element that is provided as an operating handle of the lever
mechanism, or forms or is fixed to that lever element (plunger
element) that is adapted to be operated via the operating handle
for the transfer of forces. As was already explained at the
beginning, the lever mechanism according to the invention comprises
an operating element or an operating handle that is directly or
indirectly hingedly mounted to the pump casing, and a plunger
element that is operatively connected with the lever for a transfer
of forces. The protective cap may accordingly be assigned either to
the operating handle or to the plunger element.
[0023] In case the operating handle simultaneously comprises or is
the protective cap, it may have the shape of a cover plate. In case
the force transferring lever element (plunger element) comprises or
is the protective cap, the operating handle may have the shape of a
bow-shaped handle, a buckle/operating button, a toggle lever, or a
similar ergonomic shape. Since the protective function and the
operating function are accordingly assigned to different elements
of the lever mechanism, it is possible to adapt their constructions
optimally to their remaining functions without any compromise.
[0024] In accordance with another aspect of the invention there may
be provided a tube accommodation (hook component) that is arranged
or adapted to be arranged either fixedly or displaceable in or at
the tube accommodation chamber, and into which the tube is adapted
to be inserted or is inserted/hooked via a tube holder formed or
fixed thereon. It is of advantage if, in the case of a fixed tube
accommodation, the lever mechanism acts on the now displaceable
pump head to press it against a free tube middle section
positioning itself in the fixed tube accommodation. In the case of
a displaceable tube accommodation there is provided in an
advantageous manner that the lever mechanism acts on the tube
accommodation preferably as a further element of the lever
mechanism to move it relative to the now stationary (not
displaceable) pump head such that a free tube middle section
positioning itself in the tube accommodation touches the pump head
in a manner encompassing same. In the inserted, untensioned state
the tube middle section may be straight or may already be
looped.
[0025] It may furthermore be of advantage if the lever mechanism is
designed to be self-locking, i.e. if the operating handle, when
operated, swivels across a kind of dead center for tensioning the
tube and then folds/snaps quasi automatically to its final
tensioning position. This final tensioning position may be
supported by a slight lock-in position for tactile feedback. This
makes an additional safety element such as a locking bolt
superfluous, so that operation is facilitated and the safety of the
peristaltic pump is further increased.
[0026] Finally, in accordance with another aspect of the invention
there may be provided to provide a tube unit for a peristaltic pump
in accordance with the invention (separately of the peristaltic
pump according to the invention), consisting of a tube holder
(engagement device) holding the flexible, preferably elastic tube
at two axially spaced-apart positions, or being fixedly connected
with the tube at these positions, respectively, and thus forming at
least one undercut adapted to be brought in holding engagement with
the tube accommodation of the peristaltic pump or the lever
mechanism. Thus, it is possible to manufacture the tube unit in a
very cost-efficient manner due to the few components thereof, and
it is therefore particularly suited as a disposable.
[0027] In accordance with another aspect of the present invention
there is provided a medical peristaltic pump comprising: [0028] a
pump casing in which a tube accommodation chamber is formed or
inserted in which a pump head is rotatably mounted; and [0029] a
tube unit provided preferably as an exchange component and
consisting of a tube holder adapted to be inserted displaceably in
the tube accommodation chamber and holding a flexible tube in the
form of a loop at two axially spaced-apart tube positions, wherein
the tube unit is adapted to be inserted or is inserted in the tube
accommodation chamber such that by the displacement of the tube
holder is tensionally engaged with the pump head in a manner to
encompass same at least partially.
[0030] In accordance with another aspect of the invention, there is
provided a tensioning device in the form of a lever mechanism which
is fixedly mounted (that means not provided for exchange) at the
pump casing or at the tube accommodation chamber, said lever
mechanism comprising at least one lever element (preferably the
operating element) as a (front side) protective cap for at least
partially (at the front side) covering/closing the tube
accommodation chamber, and cooperating with the tube holder for the
displacement thereof so as to pre-tension the tube around the pump
head when operated.
[0031] By the tensioning of the tube around the pump head it is
thus simultaneously covered/closed at least in sections toward the
outside (toward the open front side of the tube accommodation
chamber) and hence protected from danger.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0032] The foregoing summary and the following description will be
better understood when viewed in conjunction with embodiments
illustrated in the accompanying drawing figures, of which:
[0033] FIG. 1 shows a first embodiment of the invention with a
manually operable lever mechanism as a tensioning device with a
stationary tube accommodation and a bow-shaped operating handle in
the open (untensioned) and closed (tensioned) conditions;
[0034] FIG. 2 shows a second embodiment of the invention with a
manually operable lever mechanism as a tensioning device with a
stationary tube accommodation and a buckle-shaped operating handle
in the open (untensioned) and closed (tensioned) conditions;
[0035] FIG. 3 shows a third embodiment of the invention with a
manually operable lever mechanism as a tensioning device with a
stationary tube accommodation and a plate-shaped operating handle
in the open (untensioned) and closed (tensioned) conditions;
[0036] FIG. 4 shows a fourth embodiment of the invention with a
manually operable lever mechanism as a tensioning device with a
stationary tube accommodation and a toggle lever-shaped operating
handle in the open (untensioned) and closed (tensioned)
conditions;
[0037] FIG. 5 shows a fifth embodiment of the invention with a
manually operable lever mechanism as a tensioning device with a
displaceable/movable tube accommodation and a button-shaped
operating handle in the open and closed conditions;
[0038] FIG. 6 shows a sixth preferred embodiment of the invention
with a manually operable lever mechanism as a tensioning device
with a displaceable/movable tube accommodation and a plate-shaped
operating handle in the open (untensioned) and closed (tensioned)
conditions;
[0039] FIG. 7 shows a seventh embodiment of the invention with a
lever mechanism operable by an electric motor as a tensioning
device with a displaceable/movable tube accommodation and a gear
mechanism as a lever mechanism between the drive motor and the tube
accommodation in the open (untensioned) and closed (tensioned)
conditions; and
[0040] FIG. 8 shows the casing of a peristaltic pump according to
one embodiment of the invention with a bow-shaped operating handle
pursuant to FIG. 1 and in particular the tube accommodation chamber
in the open (untensioned) condition.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0041] FIG. 1 shows in detail a tube accommodation chamber 1 of a
peristaltic pump pursuant to FIG. 8, comprising a tensioning device
with a lever mechanism 2. As may be gathered from FIG. 8, the
peristaltic pump of the invention basically comprises a pump casing
4 at the front side of which the tube accommodation chamber 1 is
arranged such that it opens toward the front side of the pump
casing 4. Inside the tube accommodation chamber 1 there is
positioned a pump head 6 consisting of a motor-driven, rotatable
drive wheel at the radial outer circumference of which a number of
pressure wheels/rollers (not illustrated) are mounted to rotate
relatively and are distributed at regular circumferential intervals
to each other. A control panel 8 that is also placed at the front
side of the pump casing 4 serves to program a control at least for
the electric drive of the pump head so as to set, for instance, the
torque or the turn-on and turn-off times of the peristaltic pump.
Moreover, turn-on and turn-off buttons are arranged at the front
side of the pump casing.
[0042] In the embodiment of FIG. 1, the tube accommodation chamber
1 is designed in the form of a substantially rectangular shell or
depression that is either manufactured integrally with the pump
casing 4 or inserted as a separate component in a corresponding
section of the pump casing 4. At two opposing walls of the tube
accommodation chamber 1 respective indentations 12 are formed which
serve as tube accommodations and in which a tube or a tube unit 14
may be inserted. The indentations 12 are flush with each other such
that their alignment is arranged to be radially displaced to the
pump head 6.
[0043] At a side of the tube accommodation chamber 1 extending in
parallel to the alignment, the tensioning device with the lever
mechanism 2 is mounted on the pump casing 4. This lever mechanism
consists in the instant case of an operating handle 16 in the form
of a grip that is hingedly mounted on the pump casing 4 and that is
operatively connected with a shifting element (plunger component)
18 via a (not illustrated) joint, spring means, or a gear
mechanism. The shifting element 18 has, in the plan view pursuant
to FIG. 1, a substantially rectangular plate shape with a dimension
that suffices to cover the tube accommodation chamber 1 largely or
even completely. The shifting element 18 is further connected with
the axis of rotation of the pump head 6 and forms in the instant
case a bearing for the axis of rotation.
[0044] The shifting element 18 may, for instance, consist of two
plates that are spaced apart in parallel, that are fixed to each
other, and that hold the pump head between them in a rotatable
manner. In this case it is also of advantage if the (not
illustrated) drive motor for the pump head 6 is also fastened to
the shifting element 18. The shifting element 18 is guided to be
displaced at the pump casing 4 such that it cannot be lifted off
the pump casing 4. The mounting of the pump head 6 is further
chosen such that the pump head 6 projects over the shifting element
18 at the plate edge of the shifting element 18 which faces the
alignment.
[0045] FIG. 1 also illustrates the tube unit 14 that is, in
accordance with the invention, provided as a component separate of
the peristaltic pump and can optionally be inserted in the tube
accommodation chamber 1.
[0046] The tube unit 14 accordingly consists of a flexible,
preferably elastically deformable tube 20 at which two holders or
engaging elements 22 are fastened or designed at axial distance to
each other. These holders 22 form radial circumference projections
or collars that are adapted to be brought into undercut engagement
with the indentations 12 at the tube accommodation chamber 1. The
axial distance of the holders 22 is chosen such that, if the tube
20 is inserted in the two indentations 12, so that the holders 22
touch the tube accommodation chamber 1 behind the indentations 12,
the tube middle section 20a extending therebetween is not or just
slightly tensioned, so that it substantially follows the
alignment.
[0047] At the opposite side of the alignment with respect to the
shifting element 18, the tube accommodation chamber 1 is partially
covered with a fixed plate 24, wherein the fixed plate 24 comprises
an inner bulge 24a into which that part of the pump head 6 that
projects from the plate-shaped shifting element 18 in the direction
of the alignment immerses or moves in, respectively, when the tube
accommodation chamber 1 is closed.
[0048] The functioning of the peristaltic pump according to the
first preferred embodiment of the invention can be described by
means of FIG. 1 and FIG. 8 as follows.
[0049] In accordance with FIG. 1, right illustration, the tube
accommodation chamber 1 is opened in that the bow-shaped operating
handle 16 according to FIG. 1 is folded manually to the left, so
that the plate-shaped shifting element 18 along with the pump head
6 is displaced via the lever mechanism to the left, i.e. away from
the alignment. In this (open, untensioned) position it is now
possible to insert the tube unit 14 in the indentations in
accordance with the foregoing description without the exertion of
force and hence easily.
[0050] Subsequently, the bow-shaped operating handle 16 is folded
manually in the direction of the alignment, wherein this folding or
swiveling movement is transferred via the lever mechanism with an
appropriate reduction to the plate-shaped shifting element 18 for
the displacement thereof. That means, by swiveling the operating
handle 16 in the direction of the alignment, the plate-shaped
shifting element 18 is pushed forward in the direction of the fixed
plate 24, wherein the pump head 6 that is rotatably mounted thereon
is simultaneously pressed against the tube middle section 20a and
pushed forward. Since the movement distance of the shifting element
18 until it abuts on the fixed plate 24 is larger than the distance
between the inserted tube 20 and the pump head 6 in the completely
open condition, the pump head 6 is consequently quasi pressed
through the tube 20, wherein the tube middle section 20a is
tensioned between the holders 22/indentations 12 around the pump
head 6 along a partial circumference thereof. In the completely
closed condition of the tube accommodation chamber 1 in accordance
with the left illustration in FIG. 1, the tube middle section 20a
is accordingly elastically deformed in U-shape, so that a
predetermined touching force results between the pump head 6 and
the tube 20.
[0051] In the process of the swiveling movement of the operating
handle 16 in the closing or tensioning direction, respectively, it
exceeds a kind of dead center of the lever mechanism, whereupon the
operating handle 16, utilizing the tensioning force of the tube
middle section 20a which has already been generated, is urged on
the pump head 6 in the direction of the tensioned final position of
the operating handle (pursuant to the left illustration in FIG. 1).
That means, the lever mechanism according to the first embodiment
of the invention is equipped with a kind of self-locking that keeps
the operating handling 16 automatically, without additional locking
elements, in the tensioned final position.
[0052] FIGS. 2 and 3 illustrate alternative embodiments of the
tensioning device 2 pursuant to FIG. 1, wherein merely the
technical differences as compared to the first embodiment are to be
dealt with in the following while all the other technical features
substantially correspond to the first embodiment.
[0053] The embodiments pursuant to FIGS. 2 and 3 differ from the
first embodiment pursuant to FIG. 1 in the design of the manually
operable operating handle 16. In accordance with FIG. 2, the
operating handle 16 is designed as a strip-shaped buckle whereas
the plate-shaped shifting element 18 pursuant to the right
illustration in FIG. 2 is designed at its upper side with a
longitudinal groove 26 in shifting direction of the shifting
element 18 which is facing the buckle 16. In this case, the fixed
plate 24 is also provided with a corresponding longitudinal groove
28 that is flush with the longitudinal groove 26 in the shifting
element 18.
[0054] The longitudinal groove(s) 24, 26 is (are) dimensioned such
that the buckle 16 during folding in the tensioned final position
pursuant to the left illustration in FIG. 2 swivels into the
groove(s) 24, 26 and is accommodated therein almost completely.
Thus, a substantially smooth, edge-free upper side of the
plate-shaped shifting element 18 and of the fixed plate 24 results,
so that an inadvertent opening of the buckle 16, for instance, due
to getting caught, is safely avoided. This contributes to the
further improvement of the safety of the peristaltic pump according
to the invention.
[0055] Finally, the operating handle 16 pursuant to the right
illustration in FIG. 3 may also consist of a plate-shaped flap that
covers, after the folding in the tensioned final position (see left
illustration in FIG. 3), the tube accommodation chamber 1,
preferably along with the fixed plate 24, completely.
[0056] The embodiment according to FIG. 4 basically corresponds to
the afore-described embodiments, but in this case the operating
handle 16 is designed in the form of a toggle lever. In practice,
the toggle lever 16 is hinged at the tube accommodation chamber 1
or at the pump casing 4 such that its swivel axis extends
perpendicular to the front side of the pump casing 4 and hence
perpendicular to the upper side of the plate-shaped shifting
element 18. The toggle lever 16 is designed with an eccentric or a
cam 16a pressing against the thrust element 18 on rotation of the
lever 16 and displacing same in closing direction against the
inserted tube 20. Since the toggle lever 16 is not coupled with the
shifting element 18, but only touches one back edge 18a thereof, a
spring (means) that is not illustrated is provided in the instant
case, said spring (means) pre-tensioning the shifting element 18 in
opening direction (untensioned final position pursuant to the right
illustration in FIG. 4). The toggle lever 16 is also positioned
such that on reaching its tensioned final position (see left
illustration in FIG. 4) it has exceeded an (upper) dead center of
the cam 16a and is thus kept automatically in this position.
[0057] All embodiments pursuant to FIGS. 1 to 4 have in common that
the tube accommodation in the form of the two flush indentations 12
is formed/arranged stationary in the tube accommodation
chamber/duct 1, so that it is necessary for a tensioning of the
tube 20 to mount the pump head 6 to be displaceable in the
direction of the tube unit 14. There is, however, also basically
the possibility of holding the pump head 6 stationary in the tube
accommodation chamber 1 and of mounting/guiding instead the tube
accommodation 12 to be displaceable in the tube accommodation
chamber 1. In this case the tensioning device 2 need not act on the
pump head 6, but on the tube accommodation 12. In the following,
this functional principle will be exemplified by means of FIGS. 5
to 7.
[0058] FIG. 5 accordingly shows a fifth embodiment of the invention
as a simple construction for implementing the afore-mentioned
alternative tensioning principle.
[0059] In this case, the pump head 6 is, pursuant to FIG. 5, left
illustration, rotatably mounted (stationary) in the tube
accommodation chamber 1 and is driven by a motor that is not
illustrated in the pump casing 4. The tube accommodation chamber 1
is guided in a semi-circle around the pump head 6, so that a kind
of U-shaped accommodation duct or groove 1a is formed between the
tube accommodation chamber 1 and the pump head 6.
[0060] At the side of the pump head 6 radially opposite to the
accommodation duct 1a, a beam-shaped accommodation 30 is mounted in
the tube accommodation chamber 1 such that the beam 30 that is
oriented substantially tangentially to the pump head 6 is
displaceable in the transverse direction thereof. In a middle
section of the beam 30 (the beam-shaped accommodation), a
longitudinal slit 32 extending in the displacement direction of the
beam 30 is formed in the tube accommodation chamber 1, through
which a lever-shaped operating handle 16 extends which has the
shape of a button at its free projecting end. At its other,
invisible end the operating handle 16 is pivotally mounted in the
pump casing 4. In an axial middle section the lever-shaped
operating handle 16 comprises a catching element that is not
illustrated and that is in operative engagement with the
beam-shaped accommodation 30 so as to transform a swiveling
movement of the operating handle 16 with an appropriate reduction
of the lever mechanism generated thereby to a displacing movement
of the beam 30.
[0061] As may further be taken from FIG. 5, right illustration, the
tube unit 14 also comprises two axially spaced-apart collar-shaped
holders 22 that are adapted to be brought into undercut engagement
with indentations 12 in the displaceable beam-shaped accommodation
30. In this case, however, the axial distance between the two
holders 22 along the tube 20 is so large that the tube middle
section 20a bulges to a U-shaped loop between the holders 22 when
the holders 22 or the tube 20, respectively, are/is placed/inserted
in the beam-shaped tube accommodation 30 at the indentations 12
thereof. The loop has a middle radius corresponding approximately
to the U-shaped accommodation duct is around the pump head 6, so
that the tube middle section 20a may be placed around the pump head
6 in the untensioned condition almost without any effort.
[0062] As soon as the tube unit 14 has been inserted in the tube
accommodation duct 1a, the operating handle 16 is operated, i.e. in
the instant case swiveled away from the pump head 6, and thus the
beam-shaped accommodation 30 is moved away from the pump head 6.
Thus, the tube middle section 20a touches the partial circumference
of the pump head 6 with a predefined tensioning force, as is
illustrated in the right illustration in FIG. 5.
[0063] As in the afore-described embodiments, the operating handle
16 pursuant to the fifth preferred embodiment of the invention is
dimensioned such that it exceeds, shortly prior to reaching its
tensioned final position (see right illustration in FIG. 5), a dead
center whereupon the tensioning force of the tube 20 holds the
operating handle 16 in this tensioned final position.
[0064] The fifth embodiment of the invention pursuant to FIG. 5 has
a relatively simple mechanical construction since the pump head 6
can be kept stationary and merely the (preferably beam-shaped)
accommodation 30 has to be displaceable relative to the pump head
6. Thus, this construction can be manufactured in a cost-efficient
manner. However, with this solution the rotating parts are exposed
even in the tensioned final position of the operating handle
16.
[0065] For solution of this problem the sixth embodiment of the
invention pursuant to the left illustration in FIG. 6 provides a
modified operating handle 16 as compared to the fifth preferred
embodiment. In this case, the afore-described button is replaced by
a plate-shaped flap that is hinged to the pump housing 4 by means
of a hinge that is not illustrated, and that is operatively
connected with the beam-shaped accommodation 30 via a kind of
plunger component 34. The plunger component may in the instant case
consist of a bar frame that is hinged at a particular middle
position to the pivotable flap 16 and to the accommodation 30 for
achieving a lever effect. Or else, the plunger component 34 may
comprise two push rods that are displaceably mounted laterally at
the tube accommodation chamber 1 and that are coupled with the
operating handle 16 via a lever or gear mechanism so as to
transform a swiveling movement of the operating handle 16 to a
pushing movement of the push rods.
[0066] The functioning of the tube accommodation chamber 1 and in
particular of the tensioning device with a lever mechanism 2
pursuant to the sixth embodiment of the invention is substantially
the same as with the fifth embodiment. This means that the
swiveling movement of the plate-shaped flap 16 is transformed via
the plunger component 34 to a displacing movement of the
beam-shaped accommodation 30, wherein, however, simultaneously, for
tensioning the tube unit 14 (see middle illustration of FIG. 6) the
flap-like operating handle 16 covers the tube accommodation chamber
1 substantially completely when reaching the tensioned final
position pursuant to the right illustration in FIG. 6. Also in this
case is the tensioning device 2 provided with a self-locking as was
already described before by means of the fifth embodiment.
[0067] Finally, it is pointed out that the operating
handle/operating element need not necessarily be operated manually,
but can also be operated by a motor. Such motor may basically be
used with all embodiments that have already been described, for
instance, so as to apply an operating force on the operating
handle/operating element via a gear mechanism or a piston. The use
of a motor drive also enables a modification of the tensioning
device, as will be described in the following by means of the
seventh preferred embodiment pursuant to FIG. 7, middle
illustration.
[0068] Here, it is basically the matter of a tube accommodation
chamber 1 with a stationary pump head 6 and a plate-shaped cover
cap 16 that is guided in a displaceable manner at the pump casing 4
or the tube accommodation chamber 1. The cover plate 16 comprises
an accommodation for the tube unit 14 consisting of two
spaced-apart indentations 12 that are flush with each other and
into which the tube unit 14 is adapted to be inserted in an
undercut manner by means of holders/engaging elements 22 fixed
thereto (see right illustration in FIG. 7). The distance between
the two holders 22 is chosen such that the tube 20 in the inserted,
but still untensioned condition substantially follows the alignment
between the indentations 12.
[0069] In the instant case, the drive is formed by an electric
motor that is not illustrated and that is operatively connected
with the cover plate 16 via a lever mechanism consisting of an
eccentric/cam and a plunger component. Alternatively, other
constructions for a lever mechanism such as, for instance, a gear
mechanism, are, however, also conceivable.
[0070] By activating the motor, a pushing force is exerted via the
lever mechanism on the cover plate 16, so that it moves from an
open final position pursuant to the middle illustration in FIG. 7
in the direction of the pump head 6. In the process of this
movement, the tube 20 touches the pump head 6 and is, during the
further movement, tensioned around the pump head 6 until the
tensioned final position of the cover plate 16. In this case, the
self-locking effect is either produced by the motor or the
downstream lever mechanism.
[0071] In summary, the present invention relates to a peristaltic
pump for medical purposes, comprising a pump casing in which a tube
accommodation chamber is formed in which a pump head is rotatably
mounted, and a tube unit adapted to be inserted in the tube
accommodation chamber such that a tube of the tube unit is engaged
with the pump head in a manner to encompass same at least
partially. For this purpose, a tensioning device is arranged at the
pump casing which cooperates with the tube unit so as to tension
the tube around the pump head on operation thereof. In accordance
with the invention, the tensioning device comprises a lever
mechanism, wherein a lever element of the lever mechanism
preferably simultaneously forms or comprises a protective cap for
the at least partially covering of the tube accommodation.
* * * * *