U.S. patent application number 10/573276 was filed with the patent office on 2007-06-28 for peristaltic pump.
Invention is credited to Rene Fassler, Stephan Michels, Daniel Saxer, Corinne Scharer.
Application Number | 20070148010 10/573276 |
Document ID | / |
Family ID | 34383945 |
Filed Date | 2007-06-28 |
United States Patent
Application |
20070148010 |
Kind Code |
A1 |
Michels; Stephan ; et
al. |
June 28, 2007 |
Peristaltic pump
Abstract
The invention relates to a multi-channel peristaltic pump,
wherein the housing is constituted by a dimensionally stable
support frame (1) and a tube retainer (2) clipped thereto by means
of a snap connection. A rotor (3) is provided with three rotatable
delivery rolls (33a, 33b, 33c) and is mounted on the support frame
(1). The tube retainer (2) is provided with a tube bed body (25)
which defines on the inside a tube bed and at the end two legs (2a,
2b). Flexible tube sections (43) are received in the tube bed and
can be squeezed by the delivery rolls (33a, 33b, 33c) to
peristaltically deliver a medium. The two legs (2a, 2b) are
resiliently elastic so that they can be radially clipped into the
support frame (1). The tube bed body (25) has a substantially
omega-shaped design and is provided with a continuous inlet and
outlet area that ensures a peristaltic delivery of the respective
medium with only few pulsations. The inventive pump is compact in
design, consists of few components and can be quickly and easily
assembled.
Inventors: |
Michels; Stephan; (Schweiz,
CH) ; Fassler; Rene; (Schweiz, CH) ; Scharer;
Corinne; (Schweiz, CH) ; Saxer; Daniel;
(Schweiz, CH) |
Correspondence
Address: |
Michael D Beck;Maginot Moore & Beck
Chase Tower Suite 3250
111 Monument Circle
Indianapolis
IN
46204-5109
US
|
Family ID: |
34383945 |
Appl. No.: |
10/573276 |
Filed: |
June 25, 2004 |
PCT Filed: |
June 25, 2004 |
PCT NO: |
PCT/CH04/00391 |
371 Date: |
February 5, 2007 |
Current U.S.
Class: |
417/269 |
Current CPC
Class: |
F04B 43/1253
20130101 |
Class at
Publication: |
417/269 |
International
Class: |
F04B 27/08 20060101
F04B027/08; F04B 1/12 20060101 F04B001/12 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2003 |
CH |
1636/03 |
Claims
1. Peristaltic pump, with a rotor (3) received in a housing, which
is provided with at least one rotatably supported conveyor roller
(33a, 33b, 33c), as well as with a tubing holder (2) for receiving
of at least one flexible tubing section (43) that is squeezable by
the conveyor roller (33a, 33b, 33c) for peristaltically conveying a
medium, characterized in that the tubing holder (2) is provided
with a tubing bed body member (25) for receiving of at least one
flexible tubing section (43), whereby the inlet and/or the outlet
region (35,36) of the tubing bed body member (25) is designed such
that the cross sectional area of the tubing relevant for the
conveying is continuously decreased and increased, respectively, by
the conveyor roller (33a, 33b, 33c) rolling over the particular
tube section (43).
2. Pump according to claim 1, characterized in that the tubing bed
body member (25), in the inlet region (35), passes over from the
convex shape to a concave shape in a smooth transition, as seen in
the sense of rotation.
3. Pump according to claim 1, characterized in that the tubing bed
body member (25), in the outlet region (36), passes over from a
concave shape to a convex shape in a smooth transition, as seen in
the sense of rotation.
4. Pump according to claim 2, characterized in that at least two
conveyor rollers (33a, 33b, 33c) are provided, and that, with
regard to the axis of rotation of the rotor (3), the inlet region
(35) is located with regard to the outlet region (36) such that, if
one of the conveyor rollers (33a) is in the inlet region (35),
another conveyor roller (33c) simultaneously is in the outlet
region (36).
5. Pump according to claim 2, characterized in that the tubing bed
body member is designed essentially in the shape of an omega.
6. Pump according to claim 2, characterized in that e tubing bed
body member (25) at least partially and coaxially enlaces the rotor
(3).
7. Pump according to claim 2, characterized in that the tubing bed
body member (25), together with a support frame (1), constitutes
the housing of the pump, whereby the tubing bed body member has two
legs (2a, 2b) at its end which are resiliently elastic in radial
direction and provided with notch elements, by means of which the
tubing bed body member (25) can be snapped into cut-outs (13) on
the support frame (1) in the sense of a snap-on connection.
8. Pump according to claim 2, characterized in that the tubing bed
body member (25) is designed such that its dimensional stability
and fixation at the support frame (1) is supported, in addition to
the elastically resilient inherent tenseness of the legs (2a, 2b),
by the mutual force action of the squeezed tubing section and the
squeezed tubing sections (43), respectively.
9. Pump according to claim 2, characterized in that the tubing bed
body member (25) is provided with a plurality of radially and/or
axially extending reinforcing ribs (23, 24).
10. Pump according to claim 2, characterized in that the inner side
of the tubing bed body member (25) is provided with a multitude of
groove-like recesses (21) for receiving and guiding a plurality of
tubing sections (43).
11. Pump according to claim 2, characterized in that the particular
conveyor roller (33a, 33b, 33c) is in the shape of a barrel and
extends in axial directions over the groove-like recesses (21).
12. Pump according to claim 2, characterized in that the particular
tubing section is led into and out of the tubing bed body member
(25) in substantially tangential direction.
13. Pump according to claim 2, characterized in that the rotor (3)
is provided with at least two conveyor rollers (33a, 33b, 33c), and
that the tubing bed body member (25) coaxially enlaces the rotor
(3) by an amount of 360.degree. divided by the number of conveyor
rollers.
14. Pump according to claim 1, characterized in that the rotor (3)
is provided with three conveyor rollers (33a, 33b, 33c), and the
inlet portion (35) is offset around the axis of rotation of the
rotor (3) with regard to the outlet portion (36) by 210.degree. to
270.degree., preferably by approximately 240.degree..
15. Pump according to claim 2, characterized in that the tubing bed
body member (25), in the outlet region (36), passes over from a
concave shape to a convex shape in a smooth transition, as seen in
the sense of rotation.
Description
[0001] The invention refers to a peristaltic pump according to the
preamble of claim 1.
[0002] Peristaltic pumps of the kind discussed herein are
fundamentally known. They are used for conveying different liquid
and gaseous media.
[0003] A fundamental disadvantage inherent to peristaltic pumps is
that the conveying volume is not constant, but pulsates more or
less. Moreover, the torque to be delivered by the drive motor per
revolution is subject to certain variations; this is not desired as
well.
[0004] From the DE 198 14 943 A1, a tube pump of the kind referred
to herein is known. The pump is provided with a pump housing, in
which the pump tubing as well as a rotor comprising two squeezing
means in the form of rollers is received. The two squeezing means
are located one diametrically opposite to the other one. In order
to enable a conveying operation as continuous as possible, it is
proposed to increase the cross sectional area of the pump tubing in
the region where it enters the squeezing means. Thereby, in that
input region, an increased volume for conveying shall be allocated,
and a flow-back of the medium from the outlet region into the pump
tubing shall be prevented. Irrespective whether or not the desired
effect can be realized with the described characteristics, the
torque to be delivered by the drive motor per revolution is subject
to substantial variations. Moreover, the manufacture of such pump
tubing probably is very complex. Also, care has to be taken that
the pump tubing is placed with high positional accuracy into the
pump. Since tubes have the tendency to become longer the longer
they are used, the danger exists that the enlarged tubing portion
dislocates during extended use whereby the desired effect is
lost.
[0005] It is the object of the present invention to improve a pump
designed according to the preamble of claim 1 in such a way that it
provides a conveying with low pulsation, that it is not wearing out
rapidly and has a high efficiency, that commercial pump tubing can
be used, and that the torque peaks to be delivered by the drive
motor per revolution are minimal.
[0006] This object is met with a pump which comprises the
characteristics listed in the characterizing portion of claim
1.
[0007] Advantageous further developments of the peristaltic pump
are defined in the dependent claims 2 to 14.
[0008] In the following, a preferred embodiment of the invention is
further explained by means of drawings. In these drawings is shown
in:
[0009] FIG. 1 an exploded view of the peristaltic pump;
[0010] FIG. 2 the assembled pump according to FIG. 1 in a first
cross sectional view; and
[0011] FIG. 3 the assembled pump according to FIG. 1 in a further
cross sectional view.
[0012] FIG. 1 shows a six channel peristaltic pump in an exploded
view. Substantially, the pump consists of a support frame 1, a
tubing holder 2, a rotor 3 and a connecting element 4 having six
tubing sections 43 located thereon. Also evident is a gear wheel 5
for coupling to a not shown driving motor.
[0013] The support frame 1, designed to be dimensionally stable,
constitutes, together with the tubing holder 2, the real housing of
the pump. For rotatably supporting the rotor 3, the support frame 1
is provided with two bearing sleeves 11. The two front faces of the
support frame 1 are constituted by panels 12, which are provided
with slots 15a, 15b for fixing the support frame 1 and the entire
pump, respectively. Finally, the support frame 1 is provided with
several slot-like cut-outs 13 on both sides, in which notch
elements 22 of the tubing holder 2 are clampingly fixable, as will
be described further in the following.
[0014] The tubing holder 2 comprises a tubing bed body member 25,
which is designed essentially in the shape of an Omega and which
extends at the inner side in the shape of a circular arc coaxial to
the axis of rotation of the rotor 3 over an angle of appr.
130.degree. to constitute a tubing bed. The expression "in the
shape of an omega" means in the present case that the tubing bed
body member 25 has substantially the shape of a capital omega
(.OMEGA.). In the end region, the tubing bed body member 25
presents two legs 2a, 2b which, from the inside to the outside,
pass over from a concave shape to a convex shape in a smooth
transition. The tubing bed is divided into six sections by means of
groove-like recesses 21 which serve to receive the flexible tube
sections. In place of the groove-like recesses 21 for constituting
six sections, also a tubing mat, consisting of six tubes connected
to each other, could be used. In this case, the tubing bed body
member 25 could be provided with a substantially smooth inner side.
The two legs 2a, 2b of the tubing bed body member 25 are provided,
on the outer side, with notch elements 22 by means of which the
tubing holder 2 is fixable to the slot-like cut-outs 13 of the
support frame 1. The outer side of the tubing bed body member 25 is
provided with radially extending reinforcing ribs 23 as well as
with axially extending reinforcing ribs 24. The radially extending
reinforcing ribs 23 extend along appr. 180.degree. of the outer
side of the tubing bed body member 25. In any case, the tubing
holder 2 is dimensioned such that the ends of the two legs 2a, 2b
of the tubing bed body member 25 are resiliently flexible in radial
direction and make possible a quick fixing of the tubing holder 2
to the support frame 1 in the sense of a snap-on connection.
[0015] The rotor 3 consists of a rotor body 31, provided with a
central axis 32 which is inserted into the bearing sleeves 11 of
the support frame 1. Three conveying rollers 33, designed in the
shape of barrels, are rotatably supported on the rotor body 31.
Preferably, the rotor body 3 is manufactured of plastic material,
while the central axis 32 as well as the conveying rollers 33
preferably consist of metal.
[0016] The connecting element 4 consists of a base element 41, to
which are fixed twelve pipe sections 42. Attached to the upper
portions of these pipe sections 42 are a total of six flexible
tubing sections 43, which rest on the inner side of the tubing bed
body member 25, once the pump is assembled, and which are
squeezable by the conveying rollers 33 for the peristaltic
conveying of a medium. It is understood that the design of the
inlet and the outlet section is not limited to a six channel pump,
but the number of the channels is substantially arbitrarily
variable.
[0017] The assembly of the shown components to a pump can be
accomplished with a few simple steps; first, the particular tubing
sections 43 are attached to the connecting element 4 and then, the
rotor 3 is transversely moved into the tubing sections 43 forming
loops. Thereafter, the tubing holder 2 is U-shapedly positioned and
the rotor 3, together with the connecting element 4 and the tubing
sections 43 attached thereto are slid in from the top.
Subsequently, the support frame 1 is positioned upright and a
pressure is applied, such that the axis 32 of the rotor 3 as well
as the notch elements 22 snap in. Finally, the connecting element 4
is fixed to the support frame 1. In the embodiment shown here, the
connecting element 4 is fixed by means of screws. Alternatively, a
snap-on connection can be provided for fixing the connecting
element 4, which ensures a quick connection of the connecting
element 4 to the support frame 1. The entire assembly of the pump
can be performed very quickly, without the use of tools, from one
side, which constitutes an advantage in the case of an automatic
manufacture.
[0018] FIG. 2 shows a first cross sectional view of the assembled
pump. In this view, particularly the rotor body 31 together with
the three conveyor rolls 33a, 33b, 33c rotatably attached thereto
and squeezing the particular tubing section 43 in a rolling motion,
the tubing holder 2 with the omega-shaped tubing bed body member 25
as well as the radial and axial reinforcing ribs 23, 24 are
evident. The reinforcing ribs 23, 24 ensure that the tubing holder
is dimensionally stable and does not deform in operation under the
load of the conveyor rollers 33a, 33b, 33c. Assuming a sense of
rotation D in counterclockwise direction, as it is the case in the
present example, the region designated by reference numeral 35
constitutes the inlet portion, while the region designated by
reference numeral 36 constitutes the outlet portion of the pump.
Due to the omega shaped design of the tubing bed body member 25
with "soft" inlet portion and outlet portion, a continuous
substantially pulsation free conveying of the particular medium is
ensured. A further advantage of the soft inlet and outlet portions
is the reduction of torque peaks which, otherwise, would load the
motor and the gear box. The pump can be operated both in clockwise
direction and in counterclock-wise direction.
[0019] A soft and continuous inlet portion and outlet portion means
that both the inlet portion 35 and the outlet portion 36 are
designed such that the tubing cross section relevant for conveying
is continuously decreased and increased, respectively, by the
conveying roller 33a, 33c rolling along the particular flexible
tubing portion 43. In this connection, it is important that the
tubing bed body member 25 is accurately manufactured and that it
exhibits a high dimensional stability in operation such that the
predetermined distances between conveying roller 33a, 33b, 33c and
tubing bed body member 25 are maintained.
[0020] Besides the already mentioned advantage, further advantages
result from a continuous inlet portion and outlet portion; for
example, the torque fluctuations emerging from the rotation of the
rotor 3 are minimized. This is additionally favored by the facts
that the rotor 3 is provided with three conveying rollers 33a, 33b,
33c and that the inlet portion 35 is offset around the axis of
rotation of the rotor 3 by about 240.degree. relative to the outlet
portion 36, such that the first conveyor roller 33a is located
approximately in the middle of the inlet portion 35 when the third
conveyor roller 33c is located approximately in the middle of the
outlet portion 36. By means of the design shown in the drawings,
moreover, a high efficiency is realized and the mechanical load on
the tubing sections 43 is reduced, thus increasing their service
life. Since the pump is designed symmetrically, it can be operated
bi-directionally, i.e. in both senses of rotation. Additionally, as
the view shown in FIG. 2 exhibits, that the particular tubing
section 43 is not fully squeezed in the inlet portion 35 and in the
outlet portion 36, while it is fully squeezed after the inlet
portion 35 by the corresponding conveyor roller 33b to enable a
peristaltic conveying of the particular medium. A pump designed in
such a way is also particularly suitable for conveying fluid media
in a way gentle to cells, for example blood, because the blood
corpuscles are prevented from damage by the particular design of
the inlet and outlet portions 35, 36.
[0021] The design of the tubing holder 2 with a dimensionally
stable tubing bed body member 25 and with elastically resilient
legs 2a, 2b ensures a very quick and simple assembling, i.e. by
simply clicking in the tubing holder 2 into the support frame. Even
if the legs 2a, 2b have to be elastically resilient for assembly,
the tubing bed body member 25 has to maintain its dimensional
stability and a precise geometry. This goal is met, amongst else,
by the fact that the elastically resilient parts are positioned and
stiffened by means of an outer positive fitting support on the
support frame 1.
[0022] From FIG. 3, showing a cross sectional view of the assembled
pump taken between two tubing sections 43, particularly the
clamping fixation of the tubing bed body member 25 to the support
frame is evident. The notch elements 22 located at the outside of
the tubing bed body member 25 engage the slot-shaped cut-outs 13 of
the support frame 1. More-over, the notch elements 22 positively
engage an upper web 14 of the support frame, delimiting the
slot-shaped cut-outs 13. In order to ensure a high stiffness in the
flexible region of the tubing bed body member 25 fixed to the
support frame 1, the legs 2a, 2b of the tubing bed body member 25
are positively supported at the outside by the web 14 of the
support frame 1. This design particularly also ensures a precise
observation of the optimized distances between the conveyor rollers
33a, 33b, 33c and the tubing bed body member 25.
[0023] The individual elastic tubing sections 43 additionally
support the fixing of the tubing bed body member 25 at the support
frame 1, since the conveyor rollers 33a, 33b, 33c of the rotor 3
load the tubing bed body member 25 in radial direction via the
tubing sections 43, such that the fixation thereof to the support
frame 1 is additionally supported.
[0024] The connecting element 4 is designed such and matched to the
tubing holder 2 and to the rotor 3 such that the individual tubing
section 43 is led essentially in tangential direction into the
tubing bed body member 25 of the tubing holder 2 and also led out
there from.
[0025] Even if, in the foregoing, reference has made to the
embodiment shown in the drawings of a pump with three conveyor
rollers, it is understood that the number of conveyor rollers can
be practically arbitrarily varied as long as one stays within the
scope of the present invention defined in the claims. Thereby, the
tubing bed body member 25 has to enlace the rotor 3, depending on
the number of conveyor rollers, to such a degree that always at
least one conveyor roller 33a, 33b, 33c is active, i.e. engages the
particular tubing section and squeezes it. The minimal enlacement
and the minimum angle of enlacement, respectively, can be
calculated as follows: Enlacement=360.degree./number of conveyor
rollers.
[0026] In the case of using such a pump for higher pressure,
moreover, it can be advantageous to have always two conveyor
rollers engage the flexible tubing section. In this case, the
enlacement can be calculated by using the following formula:
Enlacement=2.times.360.degree./number of conveyor rollers.
[0027] The calculated enlacement is to be understood as a minimal
amount of enlacement. Preferably, the enlacement is chosen about
10.degree. higher than the angle of enlacement calculated by means
of the foregoing formula. The expression "enlacement" shall be
understood as that part of the tubing bed that coaxially surrounds
the rotor. [0028] In recapitulation, it may be noticed that a pump
designed according to the invention allows a conveying with low
pulsation, that it has a high efficiency, is barely subject to wear
and shows only low torque variations. Moreover, it is of simple and
compact design, consists of few parts and can be assembled from one
side quickly and without tools, such that it is also particularly
qualified for automatic manufacturing. Also, the housing of the
pump, consisting of support frame 1 and tubing holder 2, shows a
high dimensional accuracy and stability after having been
assembled. In addition, the pump can be bi-directionally operated
and universally used. It is particularly useful for conveying
delicate fluids like for example blood, where the corpuscles have
to be treated with care.
* * * * *