Note: Descriptions are shown in the official language in which they were submitted.
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PERISTALTIC PUMP INCLUDING AN ELASTICALLY DISPLACEABLE LOCKING
PLATE
FIELD
[0001] The field of the disclosure relates generally to peristaltic pumps.
More
specifically, the disclosure relates to a peristaltic pump head that can be
mounted to
the peristaltic pump using an elastically displaceable locking plate.
BACKGROUND
[0002] Peristaltic pumps have been known for many years, and are commonly
used for medical and research purposes. Peristaltic pumps are used, in
particular, in
research, environmental science, and chemistry laboratories, and in the
pharmaceutical, biotechnology, agriculture, and food industries. Peristaltic
pumps
move a liquid through a tube without any part of the pump touching the liquid.
As a
result, it is possible to pump liquids, such as blood, which are sensitive to
external
contamination.
[0003] Typically, a pump comprises rotating rollers that compress a part of
the
flexible tube as they move to propel the liquid through the tube. Some
peristaltic
pumps have at least one removable head through which passes the tube in which
the fluid flows. The rollers mount on the periphery of a central hub of the
head and
are driven to rotate thereby compressing the tube in succession against a
fixed wall.
The alternation of pressure and release phases of an area of the tube pumps
the
fluid to be delivered.
[0004] Some peristaltic pumps include a plurality of heads which can be
mounted
adjacent to each other and driven to rotate by the same actuator. As a result,
the
first head of the stack can be fixed on a module having a motor connected to
means
for driving the central hub of the head. Any remaining heads can be fastened
in
succession, starting at the front face of the first head. Each head is also
connected
to the means for driving the central hub of the preceding head. Inclusion of a
plurality of heads enables the supply of a fluid using a single drive module.
This is
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particularly useful, for example, in animal testing laboratories, so that a
plurality of
animals can receive the same dose of the same liquid at the same time.
Peristaltic
pumps with stackable heads are described, for example, in EP-A-O 61 9 859 and
EP-
A-0 339 857. What is needed, however, is a peristaltic pump with stackable
heads in
which the heads can be very easily added to and/or removed from the pump,
particularly without interrupting the operation of the pump for such addition
or
removal.
SUMMARY
[0005] A peristaltic pump including a mechanism for adding and/or removing one
or more pump heads to/from the peristaltic pump is provided in an exemplary
embodiment. The peristaltic pump includes, but is not limited to, a housing
for a
motor, a receiving plate mounted to the housing, a locking plate, and a
biasing
member. The locking plate, includes, but is not limited to, a first aperture
capable of
receiving a hook extending from a pump head, a second aperture capable of
receiving a drive shaft of the pump head, and a release member. The biasing
member elastically couples the receiving plate with the locking plate. Use of
the
release member by a user causes movement of the locking plate relative to the
receiving plate to release the hook when received in the first aperture
thereby
releasing the pump head from the locking plate.
[0006] Another exemplary embodiment provides a peristaltic pump. The
peristaltic pump includes, but is not limited to, a housing for a motor, a
receiving plate
mounted to the housing, a locking plate, and a biasing member. The locking
plate,
includes, but is not limited to, a hook, an aperture capable of receiving a
drive shaft
of a pump head, and a release member. The biasing member elastically couples
the
receiving plate with the locking plate. Use of the release member by a user
causes
movement of the locking plate relative to the receiving plate to release the
hook from
the pump head when the pump head is mounted to the locking plate.
[0007] Other principal features and advantages of the invention will become
apparent to those skilled in the art upon review of the following drawings,
the detailed
description, and the appended claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Exemplary embodiments of the invention will hereafter be described with
reference to the accompanying drawings, wherein like numerals denote like
elements.
[0009] FIG. I is a perspective view of a peristaltic pump including a
plurality of
pump heads in a position to be installed onto the pump and a pump head mounted
to
the peristaltic pump in accordance with an exemplary embodiment.
[0010] FIG. 2 is a perspective view of a mounting side of a pump head in
accordance with an exemplary embodiment.
[0011] FIG. 3 is a perspective view of the pump head of FIG. I showing detail
of
the drive shaft of the pump head in accordance with an exemplary embodiment.
[0012] FIG. 4 is a perspective view of a receiving plate of the pump drive
module
of FIG. 1 without a pump head mounted to the drive module in accordance with
an
exemplary embodiment.
[0013] FIG. 5 is a perspective view of the drive module of FIG. 4 showing
detail of
the drive shaft of the drive module in accordance with an exemplary
embodiment.
[0014] FIG. 6 is a perspective view of the drive module of FIG. 4 showing
detail of
the mounting mechanism for mounting a pump head to the drive module in
accordance with an exemplary embodiment.
[0015] FIG. 7 is a back perspective view of the mounting mechanism of FIG. 4
with a pump head mounted to the drive module in accordance with an exemplary
embodiment.
DETAILED DESCRIPTION
[0016] With reference to FIG. 1, a peristaltic pump 30 is shown in accordance
with
an exemplary embodiment. Peristaltic pump 30 may include a drive module 1, a
first
pump head 32, a second pump head 34, and a third pump head 36. Drive module 1
includes a housing 38 which encloses a motor. The motor drives a central hub
of the
pump heads 32, 34, 36. Housing 38 includes a control panel 4 and a display
screen
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which enable an operator to adjust operating parameters of peristaltic pump
30. A
receiving plate 6 mounts to housing 38. Receiving plate 6 includes an upper
face 2
on which a push button 3 is mounted. Using push button 3, the operator can
release
first pump head 32, or a stack of pump heads connected to drive module 1 as
described below. Receiving plate 6 is mounted on drive module 1. As used in
this
disclosure, the term "mount" includes join, unite, connect, associate, insert,
hang,
hold, affix, attach, fasten, bind, paste, secure, bolt, screw, rivet, solder,
weld, and
other like terms.
[0017] First pump head 32 includes a cassette 40, a second push button 9, and
a
second receiving plate 10. Cassette 40 includes an orifice 7 and a slide
control 8.
Cassette 40 allows a flexible tube (not shown) to be inserted into it in a
conventional
way through orifice 7. Slide control 8 can be used, also in a conventional
way, to
adjust the positioning of the internal members of cassette 40 to provide a
permanent
contact with sufficient pressure between these members and the tube inserted
into
orifice 7, regardless of the diameter of the tube used. The internal members
of
cassette 40 are essentially a central hub driven by drive module I and its
peripheral
cylinders which periodically compress the wall of the tube, thus creating the
flow of
the fluid to be delivered. Cassette 40 is of conventional design, and
therefore will not
be described or illustrated here. The previously cited prior art documents
provide
example embodiments of these internal members, whose general design can be
included within the scope of the invention in a non-restrictive way. Second
push
button 9 can be used to unlock the pump heads mounted on second receiving
plate
of first pump head 32, by means of a mechanism which is described below.
[0018] Second pump head 34 is shown ready for mounting on second receiving
plate 10 of first pump head 32. In the exemplary embodiment of FIG. 1, second
pump head 34 includes four cassettes 40, a mounting plate 11, a third push
button
9', and a third receiving plate 10'. Each of the four cassettes 40 include an
orifice 7'.
As a result, four flexible tubes, instead of one, can be inserted into second
pump
head 34. Third push button 9' can be used to release the pump heads mounted on
third receiving plate 10' of second pump head 34.
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[0019] Third pump head 36 is shown ready for mounting on third receiving plate
10' of second pump head 34. In the exemplary embodiment of FIG. 1, third pump
head 36 includes two cassettes 40', a second mounting plate 12, a fourth push
button 9", and a fourth receiving plate 10". Each of the two cassettes 40'
include an
orifice 7". As a result, two flexible tubes, instead of one, can be inserted
into third
pump head 36. In the exemplary embodiment of FIG. 1, the two orifices 7" allow
the
passage of two flexible tubes of larger diameter than the tubes which can pass
through the orifices 7, 7'. As a result, third pump head 36 may be as thick as
second
pump head 34, which allows the passage of four smaller-diameter tubes. Fourth
push button 9" can be used to release any additional pump heads which may be
mounted on fourth receiving plate 10" of third pump head 36.
[0020] With reference to FIG. 2, a perspective view of second pump head 34 is
shown in accordance with an exemplary embodiment. A face 13 of mounting plate
11 is shown. Second mounting plate 12 and/or receiving plate 6 may include a
similar face 13 for mounting to another pump head. Face 13 includes a
plurality of
hooks 17 which extend from the surface of face 13 opposite cassettes 40. Face
13
also includes an aperture 42 through which an end of a drive shaft 14 of the
central
hub of second pump head 34 extends. The plurality of hooks 17 allow the
operator
to fasten second pump head 34 either to a front face 18 of receiving plate 6
or to a
mounting plate of another pump head.
[0021] With reference to FIG. 3, aperture 42 of face 13 is shown in greater
detail.
Drive shaft 14 includes splines 15 formed by longitudinal protrusions whose
ends
have chamfers 16, the function of these being described below.
[0022] With reference to FIG. 4, housing 38 with front face 18 of receiving
plate 6
visible is shown in accordance with an exemplary embodiment. Receiving plate 6
includes an aperture 44. An end 19 of the shaft driven by the motor of drive
module
1 is accessible through aperture 44. A locking plate 22 mounts to receiving
plate 6
and includes push button 3. Depression of push button 3 causes displacement
elastically and releases a pump head connected to drive module 1. In the
exemplary
embodiment of FIG. 4, locking plate 22 includes four locking apertures 23
in.which
the plurality of hooks 17 of the mounting plate engage. With reference to FIG.
6, the
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entrance of each of the four locking apertures 23 includes a chamfer 24 which
facilitates the introduction of the corresponding hook 17.
[0023] With reference to FIG. 5, end 19 of the shaft is shown in greater
detail.
End 19 is shaped in the form of a sleeve whose inner surface has second
splines 20
formed by longitudinal protrusions whose ends have chamfers 21. Second splines
20 are designed to receive between them splines 15 of the end of drive shaft
14 of
second pump head 34. Drive shaft 14 is mounted to the shaft of drive module 1.
The chamfers 15 and 21 facilitate the reception of drive shaft 14 of the head
into the
sleeve of end 19. As a result, drive shaft 14 can be received into end 19
without the
need to stop the motor of drive module 1.
[0024] With reference to FIG. 7, a perspective view of locking plate 22
mounted to
receiving plate 6 is shown in accordance with an exemplary embodiment. Push
button 3 extends from locking plate 22 through an aperture in upper surface 2
of
receiving plate 6. Locking plate 22 includes the four locking apertures 23, an
aperture 46, and apertures 28. End 19 of the shaft driven by the motor of
drive
module I extends through aperture 46. Locking plate 22 tends to be pushed
upwards by biasing members 25, 26, being guided for this purpose by fixed
studs 27,
which extend from receiving plate 6 and penetrate into apertures 28 of locking
plate
22. Biasing members 25, 26 may be springs.
[0025] A pump head is mounted to receiving plate 6 by a simple axial movement
to engage the plurality of hooks 17 with the chamfers 24 of the four locking
apertures
23 of locking plate 22. The plurality of hooks 17 tend to push locking plate
22
downwards to allow passage through the four locking apertures 23. At this
point, the
springs 25 and 26 push locking plate 22 upwards again locking the plurality of
hooks
17 against the four locking apertures 23 of locking plate 22. In the absence
of the
chamfers 24 or similar chamfers which may be formed on the plurality of hooks
17, it
may be necessary to press push button 3 to align the plurality of hooks 17
with the
four locking apertures 23. Release of push button 3 locks the plurality of
hooks 17
against the four locking apertures 23. At the same time, the end of drive
shaft 14 of
the pump head penetrates into the end 19 of the shaft of the motor of drive
module 1,
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and the two shafts engage each other. Thus, a rotation of the motor shaft
causes a
rotation of the drive shaft of the pump head.
[0026] A subsequent depression of push button 3 releases the plurality of
hooks
17 from the four locking apertures 23. Locking plate 22 is pushed back
downwards,
thus releasing the plurality of hooks 17 and the pump head from drive module 1
by
pulling away from drive module 1.
[0027] The receiving plate 10, 10', 10" of each pump head 32, 34, 36 is
advantageously shaped in the same way as receiving plate 6 and similarly
includes a
locking plate mounted thereto as described above. In particular, each
receiving plate
10, 10', 10" includes a locking plate identical to locking plate 22 including
the four
locking apertures 23 and push buttons 9, 9', 9" corresponding to push button 3
of
drive module 1. Thus, a plurality of pump heads 34, 36 can be mounted in a
sequence starting with first pump head 32. The front end of drive shaft 14 of
the
central hub of each pump head 32, 34, 36 is shaped in the same way as end 19
of
the shaft of the motor of drive module 1, so that the shaft of the central hub
of a given
pump head 32, 34, 36 receives into itself the shaft of the central hub of the
following
pump head in the stack to drive the subsequent shaft under control of the
motor.
Thus, any number of pump heads can be mounted in sequence with the only
limitation being the driving power of the motor of drive module 1. Mounting of
the
pump heads can occur with the motor stopped or with the motor running. This
result
is achieved, in particular, by the chamfered configuration of the splines 15,
20 of the
ends of the shafts, which facilitate engagement, even when there is no exact
alignment between the shafts.
[0028] If a plurality of additional pump heads 34, 36 are mounted on first
pump
head 32 connected to drive module 1, push button 3 of drive module 1 can be
depressed to release the whole stack of heads 32, 34, 36 while keeping them
connected to each other. It is also possible to unlock a single head 32, 34,
36, or a
group of consecutive pump heads, without any need to stop drive module 1. In
alternative embodiments, the use of a head which has a mounting plate, but not
a
receiving plate can be used. In this case, the pump head is the last head of
the
stack, or the only head connected to drive module 1.
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[0029] Various modifications are possible. For example, a smaller or a greater
number of the hooks 17 and the apertures 23 may be used in a different
configuration. Additionally, the direction of displacement of locking plate 22
can be
changed, together with the shapes of the hooks 17 and the apertures 23. Push
buttons 3, 9, 9', 9" can be replaced with any functionally equivalent means
enabling
the user to displace the locking plates 22. Relative to the method of
connecting the
shafts 14 of the central hubs of the heads 32, 34, 36 to each other and to the
motor
shaft driven by the motor, their precise configurations can vary. For example,
the
positions of the sleeve on end 19 (and its corresponding parts on the pump
heads
32, 34, 36) and the end 14 of the shaft, which interacts with it, can be
reversed. In
particular, the respective positions of the locking plates 22, the hooks 17
and the
corresponding apertures 23 can be reversed. In this case, the locking plates
22 and
the apertures 23 are placed on faces 13 of the mounting plates of the pump
heads
32, 34, 36 and the hooks 17 are placed on the receiving plates. The
configuration
described and illustrated above is the most advantageous, in that it provides
drive
module 1 with a front face 18 free of fragile projecting elements, the
breakage of
which as a result of an impact would make drive module 1 unusable.
[0030] The foregoing description of exemplary embodiments of the invention
have
been presented for purposes of illustration and of description. It is not
intended to be
exhaustive or to limit the invention to the precise form disclosed, and
modifications
and variations are possible in light of the above teachings or may be acquired
from
practice of the invention. The embodiments were chosen and described in order
to
explain the principles of the invention and as practical applications of the
invention to
enable one skilied in the art to utilize the invention in various embodiments
and with
various modifications as suited to the particular use contemplated. It is
intended that
the scope of the invention be defined by the claims appended hereto and their
equivalents.
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