Roller Control For A Peristaltic Pump Construction

Abstract

A peristaltic pump assembly utilizing a housing with a circular inner wall and a rotor having outer rollers for progressively squeezing a tube lying against the wall with a provision for radial adjustment of the rollers including an eccentrically mounted bearing shaft and a two-part lock cap on the shaft having a portion to lock the cap movable to an unlock position wherein it can control the rotative position of the lock cap.

Description

This invention relates to a Roller Control for a Peristaltic Pump Construction and more particularly to a mount for pressure rollers utilized on a rotating rotor in a peristaltic pump.

It is an object of the present invention to provide a relatively simple and inexpensive roller mount which permits ready adjustment radially of the rollers to control the distance between the roller and the pressure wall of the pump.

It is a further object to provide an adjustable mount for said rollers which has a locking mechanism releasable to provide a handle for rotating the rollers and indicating position when in the released position.

It is a further object to provide a rotor control which is readily assembled and disassembled to permit replacement in case of wear or breakage.

Other objects and features of the invention relating to details of construction and operation are set forth in the following description and claims wherein the principles of operation and use are set forth in connection with the best mode presently contemplated for practicing the invention.

Drawings accompany the disclosure and the various views thereof may be briefly described as:

FIG. 1, a top view of a pump assembly.

FIG. 2, a front view of a pump assembly.

FIG. 3, a sectional view on line 3--3 of FIG. 1 staggered through the rotor to illustrate the parts thereof.

FIG. 4, a top view showing an optional housing assembly.

FIGS. 5, 6, and 7, elevation and end views of a roller mounting pin.

FIGS. 8 and 9, bottom and side views, respectively, of a snap lock for a roller control knob.

FIGS. 10 and 11, top and bottom views, respectively, of a control knob.

FIG. 12, a sectional view on line 12--12 of FIG. 10.

FIG. 13, an end view of the control knob.

REFERRING TO THE DRAWINGS

The main pump housing 10 has a circular wall 12 rising from a circular base plate 14. This wall has a circular inner surface 16 which serves as the back-up or pressure wall for the peristaltic tube which lies around this surface in the operation of the device. The wall 12 terminates at 18 on each side leaving a free circular edge 19 around the remainder of the base plate. The top surface of the base of the housing has a first boss portion 20 and a second boss 22 around a shaft well 24 (FIG. 3) containing bearings 26 which mount a power drive shaft 28. Outside the boss 20 is a circular shoulder 30 which serves to locate a second pump recess ring 32 shown in FIG. 4 having a circular pump pressure wall 34 which terminates at 36 on each side, the ring continuing in a lower wall 38 which is screwed down to the base 14 by screws 40.

On the top of the shaft 28 is a peristaltic pump rotor 42 which revolves about the axis of the shaft, this rotor having two radial arms 44 which are provided with recesses 46 at their distal ends to provide axially spaced plate extensions to receive rollers 48. Wing portions 50 extend circumferentially from the radial arms to provide a mount for guide rollers 52 which extend axially on either side of the rollers 48 to guide the peristaltic tube as the rollers move through their orbit.

Another radial projection in the form of a clevis 54 mounts a crank element 56 in a pivotal way so that the crank may be stored as shown in FIG. 1 or lifted up to serve as a manual lever for rotating the rotor. In the stored position, the crank arm passes through a notch 58 in the top of the shaft 28 and thus provides a mechanical engagement between the power shaft and the rotor.

Subjacent to rotor 42 and also mounted on shaft 28 is a splash guard ring 59 having a downturned flange which extends to a plane close to the top surface of base 14 to protect the bearings 26. This, together with the shoulder 30, keeps unwanted liquids away from the bearings. The splash guard rotates with the power shaft and thus the centrifugal action will keep liquid away from the bearings.

The circular housing 10 which has a free circular edge 19 has a frame 60 attached to the fore part at 62 by welding or suitable screws. This frame has forward extending legs 64 which are connected by a bar 66 extending along the front of the pump. This bar 66 is notched from the top edge to provide an opening 68 which enlarges at 70 to provide an essentially V-shaped recess spaced downwardly from the top edge.

Slidable on this top edge of the bar are U-shaped slides 72 with knob projections 73 and having a pin 74 extending therethrough and out beyond the back of the element 72. This pin slides in a slot 76 in the bar 66 spaced downwardly from the top edge. This slot will limit the sliding movement by contact of the pin 74 with the ends of the slot. The slides 72 are biased respectively by coil springs 78 mounted on pins 80. These coil springs have one end 82 which is anchored in the bar 66 and another end 84 which extends upwardly to contact the pins 74. Thus, the springs will tend to move the slides outwardly from the center of the assembly. The slides have also V-shaped notches 86 in their leading edges positioned to register with the notches 70 in the front cross bar 66.

Reference to FIG. 2 will show that these openings formed by the notches 70-86 can be large as shown at the right or relatively small as shown at the left. In addition, the slides can be shifted to the point that tubes can be introduced through the openings 68 to facilitate the threading of the unit.

It will be appreciated that while FIG. 1 shows the unit in the condition to utilize the inner wall 16 as the pressure wall for the pumping action, the unit shown in FIG. 4 is designed for use of the pressure wall 34 formed by the ring housing 32 which is mounted and located on shoulder 30 on the bottom wall or base plate 14. A rotor exactly similar to that shown in FIG. 1, but in smaller scale, can be selectively mounted around the shaft 28 and otherwise the function is the same. In each case, the tubes pass through the openings in the cross plates 66 and are held under resilient pressure by the slides 72.

In FIG. 3, the mounting of the rollers 48 is illustrated. These rollers on suitable bearings 90 are mounted on a pin 92 at concentric portions 92a and 92b of the pin and are designed to be adjustable radially. Details of pin 92 are illustrated in FIGS. 5, 6 and 7. This adjustment is accomplished by placing a mounting projection 94 at the bottom of the pin 92 eccentrically of the pin and also disposing a top portion 96 of the pin similarly eccentric to the main body portion 92. This eccentricity is shown in dotted lines in FIG. 1. The top of the pin has a concentric threaded stem 97 to remove a nut 98.

The rotative position of pin 92, and thus the degree of radial adjustment of the rollers 48, is controlled by a lock cap 100 shown in FIGS. 1 and 3 and detailed in FIGS. 10 to 13. This cap has a central base 102 which connects two arcuate portions 104 and 106 between which is a diametrical slot 108. The base has a central flap 110 with a chordal flat at one side to fit over and engage the threaded stem 97 of the pin 92. The base also has an arcuate slot 112 to cooperate with a pin 114 (FIG. 3) to limit the motion of the pin and the lock cap control.

Thus, the lock cap slips over the stem 97 wherein the respective flats in hole 110 and on stem 97 engage, and is held in place by nut 98 acting on a wave washer 116. A snap lock member 120 is designed to fit in slot 108 between arcuate portions 104, 106. The distal operative end of this member has a turned in flap 122 which serves as a stop and the opposite end has a turn down 124 terminating in a cam heel portion 126 eccentric to a pivot opening 128.

The lock cap is shown in closed position in FIG. 3, the anchor or hinge portions 124 being mounted on a cross-pin 127 having its ends mounted in openings in arcuate side portions 104-106. In this position, the eccentric heel 126 is slightly overcenter but maintaining a pressure the wave washer 116 to hold lock cap 100 in place. When the snap-lock member 120 is pivoted upwardly around pin 127, the pressure on the wave washer is relieved and the lock cap can be readily rotated to adjust the position of eccentric roller mount pin 92 and the roller 48 carried by it. In the unlocked position, the member 120 serves to assist in the movement of the lock cap and as an angle indicator in controlling the position relative to the other lock cap so that each may be positioned similarly or at desired points of rotation relative to the rotor per se.

Thus, a relatively simple control is available for adjusting the position of rollers 48 relative to the pressure wall in an infinite number of control positions.

Claims

I claim:

1. In a peristaltic pump construction in which a rotor carrying pressure rollers moves within a circular pressure wall, that improvement in a roller mount which comprises:

a. a rotor having radial portions provided with axially spaced plate extensions each having a circular recess on a common center line,

b. a roller to be mounted between said plate extensions,

c. a pin for mounting said rollers having a first portion on a first center line to serve as a bearing mount for a roller,

d. second portions on said pin on opposite sides of said first portion circular in cross-section and on a second center line spaced from said first center line to be in eccentric relation to a roller mounted on said first portion, said second portions being received respectively in said circular recesses in said spaced plate extensions, and

e. means on one end of said pin having a portion pivotally mounted on an axis normal to said center lines and releasably engageable with one of said extensions and rotatable to control the rotative position of said pin and thus the radial position of a roller on said pin.

2. A device as defined in claim 1 in which said means comprises a cap having a base portion lying in contact with one side of said plate extension and mounted for limited rotation relative to said extension, means on said pin engaged with a portion of said base portion, and locking means on said cap movable to a locking position engaging said one side of said plate extension, and movable to a release position disengaged from said plate extension to permit rotation of said pin by movement of said cap to any selected position of adjustment within the limits of rotation of said base portion.

3. In a peristaltic pump construction in which a rotor carrying pressure rollers moves within a circular pressure wall, that improvement in a roller mount which comprises:

a. a rotor having radial portions provided with axially spaced plate extensions each having a circular recess on a common center line.

b. a roller to be mounted between said plate extensions,

c. a pin for mounting said rollers having a first portion on a first center line to serve as a bearing mount for a roller,

d. second portions on said pin on opposite sides of said first portion circular in cross-section and on a second center line spaced from said first center line to be in eccentric relation to a roller mounted on said first portion, said second portions being received respectively in said circular recesses in said spaced plate extensions,

e. means on one end of said pin releasably engageable with one of said extensions to control the rotative position of said pin and thus the radial position of a roller on said pin, said means comprising a cap having a base portion lying in contact with one side of said plate extension,

f. means on said pin engaged with a portion of said base portion,

g. locking means on said cap movable to a locking position engaging said one side of said plate extension, and movable to a release position disengaged from said plate extension to permit rotation of said pin to any selected position of adjustment, said means on said pin being engaged with a portion of said base portion and comprising an out-of-round extension passing through a similar out-of-round opening in said base, and

h. a spring washer on said extension held in place by a fastener on said out-of-round extension, said locking means on said cap having a cam portion to contact said one side of said plate extension and compress said washer when in locking position.

4. In a peristaltic pump construction in which a rotor carrying pressure rollers moves within a circular pressure wall, that improvement in a roller mount which comprises:

a. a rotor having radial portions provided with axially spaced plate extensions each having a circular recess on a common center line,

b. a roller to be mounted between said plate extensions,

c. a pin for mounting said rollers having a first portion on a first center line to serve as a bearing mount for a roller,

d. second portions on said pin on opposite sides of said first portion circular in cross-section and on a second center line spaced from said first center line to be in eccentric relation to a roller mounted on said first portion, said second portions being received respectively in said circular recesses in said spaced plate extensions,

e. means on one end of said pin releasably engageable with one of said extensions to control the rotative position of said pin and thus the radial position of a roller on said pin, said means comprising a cap having a base portion lying in contact with one side of said plate extension,

f. means on said pin engaged with a portion of said base portion, and

g. locking means on said cap movable to a locking position engaging said one side of said plate extension, and movable to a release position disengaged from said plate extension to permit rotation of said pin to any selected position of adjustment, said cap comprising a circular disc having arcuate portions on either side of said base portion providing a diametrical slot above said base, said means on said cap movable to a locking position comprising a lever arm pivoted at one end of said slot having a cam portion to contact said one side of said plate extension in locked position.

5. A device as defined in claim 3 in which said cap comprises a circular disc having arcuate portions on either side of said base portion providing a diametrical slot above said base, said locking means being movable into and out of said slot in respective locked and unlocked positions.

6. A device as defined in claim 5 in which said base portion has an arcuate slot and a pin on said plate extension to extend into said arcuate slot to limit the rotation of said cap.

7. A device as defined in to limit 5 in which said locking means is generally U-shaped having one leg of the U pivoted at one end of the diametrical slot and the other leg serving as a positioning stop in the locked position of said locking means.