US3396669A - Roller pump - Google Patents

Description

Aug. 13, 1968 H. F. EVERETT ROLLER PUMP Filed July 13, 1966 I g E Illlllllllll Liz i.

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INVENTOR.

HAZEN F. EVERETT ATTORNEY United States Patent 3,396,669 ROLLER PUMP Hazen F. Everett, 120 Bedford Road, Hillsdale, NJ. 07642 Filed July 13, 1966, Ser. No. 564,988 9 Claims. (Cl. 103149) ABSTRACT OF THE DISCLOSURE A roller pump having a fluid conducting flexible tube arranged in a helical turn against a cylindrical side wall surface of a housing cavity so as to have fluid pumped through the tube when squeezed against such surface .by a roller rolling along the turn is provided with a tubular shaft journalled coaxially with the side wall surface and having a rotor fixed thereto and carrying the roller, a drive shaft loosely received in the tubular shaft, a handle pivoted on the rotor to move between a radially outward directed position where the handle is manually actuable to effect rotation of the rotor independent of the drive shaft and a stored position extending over the tubular shaft, and a coupling rotatably connecting the drive shaft and tubular shaft only when the handle is in its stored position. Desirably, such coupling is constituted by a flat-sided element carried by the handle and which may constitute a knob thereon, and diametrical notches or recesses in the drive shaft and tubular shaft alignable with each other to receive the flat-sided element in the stored position of the handle.

This invention relates generally to roller pumps, that is, to pumps of the type in which a flexible, preferably resilient tube for conducting a fluid has a portion of its length disposed in the form of one or more helical turns against a generally cylindrical surface, and a roller positioned to squeeze the tube against the cylindrical surface is made to travel along a circular path which is concentric with the cylindrical surface, thereby to propel the fluid through the flexible tube.

In roller pumps of the described character, the moving parts of the pump do not come in contact with the fluid conducted through the flexible tube so that such pumps are ideally suited for pumping fluids that are to be maintained in sterile condition or are corrosive. Roller pumps further provide a gentle pumping action and this characteristic, and the possibility of maintaining sterility, have led to the preference for roller pumps for the pumping of blood, for example, when the circulation of blood is bypassed around the heart and lungs of a patient during open-heart surgery.

Existing roller pumps are of complex construction, particularly when the flexible tube through which the fluid is conducted is to be replaceable, and replacement of the flexible tube is a time consuming operation and requires substantial disassembly of the pump structure. Further, in existing roller pumps, the roller is mounted on a rotor which is securely connected to a drive shaft extending from a motor powered drive unit so as to be normally rotated by the latter. Although some of the existing roller pumps are provided with a crank or handle by which the rotor may be manually rotated when the drive unit is inoperative, such manual rotation must be effected with the rotor connected or coupled to the drive shaft, and thus is opposed by the substantial resistance to rotation of the reduction vgearing and motor of the drive unit. It will be apparent that, when a roller pump is employed for the pumping of bypassed blood during open-heart surgery, it is essential that the pumping of blood not be interrupted or adversely affected by a failure of the electric motor driving the pump. However, if manual rotation of the pump rotor is opposed by the resistance of the inoperative drive "ice unit, as in existing roller pumps, such manual rotation of the rotor can cause extreme fatigue to the operator, particularly if continued for an extended period.

Accordingly, it is an object of this invention to provide a roller pump of simple construction which facilitates the replacement, in the pump housing, of the flexible tube through which the fluid is to be conducted.

Another object is to provide a roller pump having a rotor carrying a roller along a circular path in response to rotation of the rotor, and wherein rotation of the rotor is normally effected by the coupling thereof to a drive shaft extending from an electric motor powered drive unit, but such coupling can be easily disengaged so as to permit manual rotation of the rotor independent of the drive shaft.

A further object is to provide a roller pump in which the extent to which the flexible tube is squeezed or flattened against the cylindrical wall surface may be easily and accurately adjusted thereby to vary the volume of fluid pumped through the flexible tube during each revolution of the rotor.

A still further object is to provide a roller pump of the described character in which replacement of the fluid conducting tube, adjustment of the squeeze or nip of the tube by the roller, and the change-over from powered to manual operation can be effected without the use of any separate tools or devices.

In accordance with an aspect of this invention, a roller pump is provided with a housing having a cavity with a generally cylindrical side wall surface and inlet and outlet bores extending to and from the cavity in tangential relation to the side wall surface for leading a fluid conducting flexible tube to and from at least one helical turn lying against the side wall surface, a tubular shaft is journalled in the housing to extend into the cavity coaxially with the cylindrical wall surface of the latter and loosely receives a drive shaft extending from a drive unit on which the pump housing is mounted, a rotor is fixed on the tubular shaft for rotation therewith within the cavity and carries roller means for squeezing the flexible tube against the side wall surface and rolling along the helical turn of the tube upon rotation of the rotor, a handle is pivoted on the rotor to move between a radially outward directed position, where the handle is manually actuable to eifect rotation of the rotor independent of the drive shaft, and a stored position extending over the tubular shaft, and means on the handle is operative to rotatably couple the tubular shaft with the drive shaft when the handle is in its stored position.

In accordance with another aspect of this invention, the inlet and outlet bores for leading the flexible tube to and from the cavity of the housing have their axes extending in opposed directions in the same plane, and the housing is divided, at such plane containing the axes of the bores, into two separable portions, with mounting means being provided to normally hold one of the housing portions against the other of such portions at the plane of division therebetween, and such mounting means is actuable to permit separation of the two housing portions at the plane of division therebetween, thereby to facilitate the replacement of the flexible tube in the housing cavity and in the bores leading to and from such cavity.

In accordance with another feature of this invention, the roller for squeezing the flexible tube against the cylindrical side wall surface of the housing cavity is rotatably mounted on a member which is pivotally carried by the rotor, with the pivoting axis of such member being parallel to, and spaced from the axes of rotation of the rotor and of the roller so that pivoting of the member relative to the rotor effects movement of the roller toward and away from the side wall surface, and adjustable means member with respect to'the rotor and thereby determine the extent of the squeezing of the flexible tube by the roller.

The above, and other objects, features and advantages of this invention, will be apparent in the following detailed description of an illustrative embodiment thereof which is to be read in connection with the accompanying drawing, wherein:

FIG. 1 is a side elevational view of a roller pump embodying this invention;

FIG. 2 is a top plan view of the pump of FIG. 1, but with a lid thereof shown in open position and partly broken away;

FIG. 3 is a vertical sectional view taken along the line 33 on FIG. 2;

FIG. 4 is a detail sectional view taken along the line 44 on FIG. 3, but with a handle of the pump being shown in its position for effecting manual operation of the pump;

FIG. 5 is a detail sectional view taken along the line 5-5 on FIG. 2, but with a portion of the pump housing being shown in its open position to facilitate replacement of the flexible tube through which fluid is to be conducted;

FIG. 6 is a detail side elevational view of a rotor assembly included in the pump;

FIG. 7 is a fragmentary sectional view taken along the line 77 on FIG. 4;

FIG. 8 is a fragmentary sectional view taken along the line 88 on FIG. 4; and

FIG. 9 is a fragmentary elevational view of a portion of the rotor assembly, as viewed from the side opposed to that appearing on FIG. 6.

Referring to the drawing in detail, and initially to FIGS. 1 and 2 thereof, it will be seen that a roller pump 10 embodying this invention generally comprises a pump housing 11 having an upwardly opening cavity 12 with a cylindrical side wall surface 13, and further having bores 14 and 15 that extend from the opposite sides of housing 11 and open into cavity 12 in tangential relation to side wall surface 13. As shown, bores 14 and 15 are disposed at different levels above the bottom of cavity 12 (FIG. 1) and have their axes lying in the same plane 16 at which, in accordance with this invention, housing 11 is divided into portions 11a and 11b, respectively. It will be seen that the plane 16 of separation or division between housing portions lla and 11b extends chordally across cavity 12 close to side wall surface 13 thereof so that the major part of cavity 12 is disposed in housing portion 11a (FIG. 2).

Housing portion 11a is formed with a flange 17 (FIGS. 1, 3 and 5) projecting horizontally from the bottom of portion 11a beyond the face 16a thereof which corresponds to the plane of separation, and the ends of flange 17 are formed with cut-outs 18 (FIGS. 1 and 5) to receive lugs 19 depending from housing portion 11b. Lugs 19 are pivotally mounted on the ends of a shaft 20 extending longitudinally through flange 17 and projecting into cutouts 18. Thus, housing portion 11b is pivotally mounted for movement about the axis of shaft 20 be tween an open position (FIG. 5) in which faces 16a and 16b of the housing portions are substantially angularly separated, and a closed position (FIG. 1) in which faces 16a and 16b of the housing portions come together at the plane of separation 16.

Housing portion 11b may be urged to its open position (FIG. 5) by means of one or more helical compression springs 21 seated in sockets opening at faces 16a and 16b above the axis of shaft 20. In order to normally hold housing portion 11b in its closed position, housing portion 11b may be formed, adjacent its opposite ends, with extensions 22 having threaded bores extending therethrough to receive locking screws 23. Screws 23 exit from-.- the respective threaded bores at the lower ends of extensions 22 and are engageable with flange 17. Thus, when locking screws 23 are turned in the direction to effect upward'rnovement thereof with respect'to housing portion 11b, the latter is free to be rocked by springs 21 to its open position (FIG. 5). However, when locking screws 23 are turned in the opposite direction to project increasingly downward from extensions 22, the lower ends of screws 23 bear on flange 17 in back of shaft 20, and thus effect rocking of housing portion 11b to its closed position(FIG.1).

It will be apparent that, when housing portion 11b is in its open position, there is an open gap in side wall surface 13 of the major part-of cavity 12 defined in housing portion 11a and, further, the bores 14 and 15 appear as semi-cylindrical grooves in the angularly separated faces 16a and 16b of the housing portions. Thus, a flexible, preferably resilient tube 24 of plastic or the like can be easily laid in the open groove-like sections of bores 14 and 15 in face 16a and formed therebetween into a helical turn lying against side wall surface 13 of the major part of cavity 12 in housing portion 11a. After such disposition of flexible tube 24 with respect to housing portion 11a, housing portion 111) may be moved to its closed position, as described above, so as to enclose, and thereby hold, portions of tube 24 in bores 14 and 15.

Housing portion 11a further has a vertical bore 25 concentric with cavity 12 and extending from the bottom of the cavity to open at the lower surface of the housing (FIG. 3). Bore 25 has a flange 26 therein intermediate its length to provide seats for tapered roller bearings 27a and 27 b disposed below and above flange 26 within bore 25. Bearings 27a and 27b rotatably support a tubular shaft 28 having an outwardly directed flange 29 at its upper end (FIGS. 2 and 4) and an externally threaded lower end portion 30.

A rotor assembly 31 is carried .by the upper end portion of tubular shaft 28 which extends into cavity 12. Rotor assembly 31 includes an elongated body 32 which, approximately at its middle, is formed with a vertic'albotre 33 (FIGS. 3 and 7) diametrically dimensioned to permit tubular shaft 28 to extend downwardly therethrouglh with flange 29 of the tubular shaft seating on the upper surface of rotor body 32. Rotor body 32 is held against rotation relative to tubular shaft 28, for example, by a set screw 34 (FIG. 6). Disposed between rotor body 32 and upper bearing 27b is 'a cover or spacing disk 35, and nuts 36 are engaged with the threaded lower portion of shaft 28 to hold the latter against upward removal from within bearings 27:: and 27 b and further to retain the bearings in seated engagement with flange 26.

As indicated on FIGS. 1 and 3, pump housing 11 is intended to be mounted upon a drive unit 37 that contains an electric motor and reduction gearing (not shown) through which the motor effects rotation, at a controlled variable speed, of an upwardly projecting drive shaft 38.

Drive shaft 38 is dimensioned to extend loosely into tubular shaft 28 and to project to the upper end of the latter when housing 11 is mounted on top of drive unit 37. As shown on FIG. 1, housing 11 may be removably secured on drive unit 37 by means of bolts 39 (FIG. 1) having their heads received in cavities 40 provided in the opposite sides of the casing of drive unit 37 and extending through holes opening upwardly from cavities 40 into tapped bores 41 opening at the bottom surface of housing portion 11a.

Rotor assembly 31 further includes a handle 42 which is pivotally mounted, at one end, on a pivot 43 extending laterally between lugs 44 projecting upwardly from rotor body '32 adjacent one end of the latter. Thus, handle 42 is :swingable between a stored position where it extends longitudinally on top of body 32 over the upper end of tubular shaft 28, as indicated in full lines on FIGS. 2 and 3, and a radially outward directed position, as indicated in broken lines on FIG. 3 and in full lines on FIG. 4. The upper end of tubular shaft 28 has diametrically opposed notches 45 opening through flange 29 (FIGS. 4

and 7) and drive shaft 38 has a diametrically extending slot 46 therein for angular registration with notches 45. A

flat-sided element 47 is mounted on handle 42 adjacent the free end of the latter, as by a pin 48 (FIG. 4), so as to be capable of rotation relative to handle 42 about an axis at right angles to the axis of pivot pin 43. Element 47 is dimensioned and located with respect to handle 42 so that, when the latter is in its stored position extending over the upper end of tubular shaft 28, flat-sided element 47 depends from handle 42 and engages simultaneously in notches 45 of tubular shaft 28 and in slot 46 of drive shaft 38, thereby to couple rotor assembly 31 to drive shaft 38 for rotation by drive unit 37.

However, when handle 42 is pivoted to its radially outward directed position, element 47 projects upwardly from the outer end of the handle and constitutes a knob that can be conveniently grasped for elfecting manual rotation of rotor assembly 31. Further, when handle 42 is in its radially outward directed position, rotor assembly 31 is uncoupled from drive shaft 38, and thus its manual rotation can be effected without being opposed by the resistance to rotation of drive unit 37 when the latter is inoperative. In order to yieldably retain handle 42 in either its stored position or its radially outward directed position, handle 42 has one side thereof formed with recesses or depressions 49 (FIG. 3) at diametrically opposed locations with respect to its pivoting axis, and such recesses are selectively engaged by a spring urged ball or detent 50 (FIG. 4) mounted in one of the lugs 44.

The end of rotor body 32 remote from lugs 44 has an extension 51 (FIG. 4), at one side, carrying a pivot pin 52 which is vertical, that is, parallel to the axis of rotation of the rotor assembly. A roller support member 54 (FIG. 6) has upper and lower webs 55 spaced apart to engage above and below extension 51 and being connected, at one side, by a bar or post 56. Webs 55 are pivotally mounted on the ends of pin 52 projecting from extension 51 so that roller support member 54 is mounted for pivoting with respect to rotor body 32. A roller 57 is rotatably mounted on a shaft 58 carried, at its opposite ends, by webs 55 and being parallel, and offset with respect to pivot pin 52. Thus, pivoting of member 54 relative to rotor body 32 is effective to move roller 57 toward and away from side Wall surface 13 of cavity 12, and thereby vary the extent to which roller 57 squeezes the helical turn of flexible tube 24 lying against surface 13.

A hollow screw 59 extends laterally through a tapped bore in extension 51 of the rotor body (FIGS. 4 and 8) and is provided wtih a manually actuable head or knob 60 at its outer end. The interior of hollow screw 59 is threaded, as at 61 (FIG. 8), and receives a setting screw 62 which projects a variable distance from the inner end of hollow screw 59 to engage against the bar or post 56 of roller support member 54. A lock screw 63 may also be threaded into screw 59 to hold the adjustment of setting screw 62 with respect to hollow screw 59. It will be apparent that rotation of knob 60 causes variation of the axial position of screw 59, and of the end of setting screw 62 projecting therefrom, relative to extension 51 and thereby varies the extent to which member 54 can pivot in the direction for moving roller 57 away from side wall surface 13.

As shown on FIG. 9, the outer surface of knob 60 and the adjacent surface of rotor body 32 may be provided with a cooperating scale 64 and index 65 calibrated to indicate the position of roller 57 with respect to side wall surface 13 or the extent to which roller 57 squeezes the helical turn of tube 24.

The described arrangement for setting the position of roller support member 54 with respect to rotor body 32 makes it possible to apply scale 64 and index 65 to the respective surfaces prior to assembly of the pump, without regard to the manufacturing tolerances, and, after assembly of the pump, to adjust setting screw 62 with respect to hollow screw 59 so that roller support member 54 is held in the position where roller 57 engages side wall surface 13 when knob 60 is rotatonally positioned to dispose the zero indication on scale 64 next to, index 65. Thereafter, setting screw 62 is locked relative to hollow screw 59 by locking screw 63 so that subsequent indications provided by scale 64 and index 65 will accurately reflect the position of roller 57 with respect to the adjacent side wall surface 13.

In order to ensure that tube 24 is held at vertical positions on side wall surface 13 within the axial extent of roller 57, and thus is not squeezed out beyond the ends of the roller and pinched between the latter and webs 55, the edges of webs 55 of roller support member 54 closest to side wall surface 13 are provided with lips 66 (FIGS. 6 and 9) directed toward each other beyond the ends of roller 57.

Pump 10 may further be provided with a cover or lid 67 (FIGS. 1 and 2) in the form of a plate 68, preferably of a transparent plastic, which is coextensive with the top of housing 11, and which has secured thereto, adjacent one edge of the plate 68, lugs 69 that are laterally bored to receive an axle 70 extending laterally between extensions 22 of housing portion 111). Thus, lid 67 is swingable about axle 70 between a closed position, as shown in full lines on FIG. 1, Where plate 6-8 extends over the top of housing 11 and is spaced upwardly from rotor assembly 31 by the engagement of lugs 69 with the top surface of housing 11, and an open position, as indicated in broken lines on FIG. 1 and in full lines on FIG. 2, where the lid or cover 67 is disposed to one side of the pump housing to permit free access to rotor assembly 31, for example, when it is desired to effect manual rotation thereof, adjustment of the setting of roller 57 or replacement of tube 24.

It will be apparent that, in roller pump 10, as described above, replacement or installation of tube 24 in the pump housing merely requires the movement of housing portion 11b to its open position by manipulation of screws 23 and, during such removal or installation of tube 24, rotor body 32 is preferably disposed so that the end portion thereof carrying roller support member 54 extends toward the gap in cylindrical side surface 13 defined at face 16a of housing portion 11a. By reason of the ease with which tube 24 can be replaced, such tube can conveniently be part of a disposable assembly of previously sterilized tubing suitably connected to associated apparatus, for example, an oxygenator or the like. Further, it will be apparent that the changeover from operation of the pump by motor powered drive unit 37 to manual operation can be quickly effected merely by moving handle 42 from its stored position where element 47 serves to couple together shafts 2-8 and 38, to its radially outward directed position where element 47 constitutes a knob that can be conveniently grasped for manually rotating rotor assembly 31. It is also obvious that adjustments of the position of roller 57 with respect to side wall surface 13 can be conveniently and accurately effected merely by rotation of knob 69, thereby to adjust the volumetric rate and pressure at which fluid is pumped through tube 24. It should be noted that, in replacing tube 14, changing over from powered to manual operation or adjusting the squeeze or nip of tube 14, no tools or devices separate from the pump 10 are required. The foregoing features of pump 10 are all particularly advantageous for its application in the pumping of blood or other fluids in surgical apparatus, but it will be apparent that such features are advantageous when the pump is employed in other a plications, for example, in the chemical industry for pumping corrosive fluids that do not attack the plastic material of tube 24.

Although an illustrative embodiment of the invention has been described in detail herein with reference to the accompanying drawing, it is to be understood that the invention is not limited to that precise embodiment, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention, as defined in the appended claims.

What is claimed is:

1. A roller pump comprising a housing having a cavity with a generally cylindrical side wall surface and inlet and outlet bores extending to and from said cavity in tangential relation to said side wall surface for leading a fluid conducting flexible tube to and from at least one helical turn lying against said surface, a tubular shaft journalled in said housing coaxially with said cylindrical wall surface and having an end portion projecting into said cavity, a drive shaft loosely received in said tubular shaft and extending into said end portion thereof, a rotor fixed on said end portion of the tubular shaft for rotation therewith, roller means carried by said rotor for squeezing the flexible tube against said side wall surface and rolling along the turn of the tube upon rotation of said rotor, a handle pivoted on said rotor to move between a radially outward directed position, where the handle is manually actuable to effect rotation of said rotor independent of said drive shaft, and a stored position extending over said tubular shaft, and means operative to rotatably couple said tubular shaft with said drive shaft only when said handle is in said stored position thereof.

2. A roller pump according to claim 1; wherein said end portion of the tubular shaft has diametrically opposed notches opening axially therein and said drive shaft has a diametrical slot opening axially and being alignable with said notches, and said means for rotatably coupling the tubular shaft with the drive shaft includes a fiat-sided element carried by said handle and fitting into the aligned slot and notches in said stored position of said handle.

3. A roller pump according to claim 2; wherein said flat-sided element is mounted on said handle for rotation relative to the latter about an axis which is parallel to, and spaced from the axis of rotation of said tubular shaft and rotor in said radially outward directed position of the handle to constitute a knob which can be grasped in effecting the manual rotation of the rotor.

4. A roller pump according to claim 1; further comprising detent means for releasably retaining said handle in each of said radially outward directed and stored positions thereof.

'5. A roller pump according to claim 1; wherein said inlet and outlet bores have their axes extending in oppose-d directions in the same plane and said housing is divided, at said plane, into two portions; and further comprising means mounting one of said portions of the housing on the other of said portions and permitting separation of said one portion from said other portion at said plane, thereby to facilitate the installation of the flexible tube in said bores and cavity.

6. A roller pump according to claim 5; wherein said means mounting said one portion on said other portion includes pivot means defining an axis about which said one portion is rockable between closed and opened positions with respect to said other portion, said axis of the pivot means being parallel to, and spaced from said axes of the bores.

7. A roller pump according to claim 6; further comprising means yieldably urging said one portion of the housing to rock said open position, and manually operable means for releasably retaining said one portion in said closed position thereof.

8. A roller pump according to claim 1; wherein said rotor includes a body extending radially from said tubular shaft, a member mounted on said body adjacent said side wall surface and being pivotally movable with respect to said body about an axis parallel to the axis of said tubular shaft, said roller means including a roller mounted on said member for rotation about an axis parallel to, and offset from said axis of pivoting of said member so that said roller moves toward and away from said side wall surface in response to pivoting of 'said member with respect to said body, and adjustable means to pivotally position said member with respect to said body and thereby determine the extent of the squeezing of the flexible tube by said roller means.

9. A roller pump according to claim 8; wherein said adjustable means includes a hollow screw extending threadably through said body in a direction at right angles to and spaced from said axis of pivoting of said member on said body, a setting screw threaded in said hollow screw and projecting axially from one end of the latter to bear against a surface of said member for limiting pivotal movement of the latter in the direction moving said roller away from said side wall surface, a head on the other end of said hollow screw by which the latter can be manually adjusted, and cooperating scale and index means on said head and an adjacent surface of said body calibrated to indicate the position of said roller with respect to said side wall surface.

References Cited UNITED STATES PATENTS 2,035,159 3/1936 Henry 103-149 2,306,751 12/1942 Reymond 103-149 2,909,125 10/1959 Daniels 103-149 2,955,543 10/1960 Daniels 103-149 FRED C. MATTERN, JR., Primary Examiner.

WILBUR J. GOODLIN, Assistant Examiner.

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