Two-cycle peristaltic pump with occlusion detector
First Claim
1. A device for pumping fluid through a resilient tube which comprises:
- a base;
a platen mounted on said base for holding said tube;
means mounted on said base for alternately squeezing said tube against said platen at a first and second location;
means mounted on said base for alternately occluding said tube upstream from said first location and between said first and second locations, said first location being squeezed as said tube is occluded upstream from said first location;
a strain gauge mounted on said base and operatively coupled with said tube at a third location thereon, for sensing fluid pressure in said tube at a first time when said tube downstream from said third location is open and at a second time when said tube upstream from said third location is open;
photoelectric sensor means attached to said base for indicating a position of said squeezing means as it is pushed outwardly to a withdrawn position; and
the pressure sensor operating in combination with the position sensor to provide a means for determining whether the device is delivering fluid at an acceptable rate.
13 Assignments
0 Petitions
Accused Products
Abstract
A linear peristaltic pump for pumping fluid through a resilient tube has a pair of pumping fingers, a pair of pinching fingers, and a strain gauge to monitor pressure inside the tube. The first pumping finger squeezes the tube at a first location, and the second pumping finger squeezes the tube at a second location. Additionally, the first pumping finger is configured and operated to displace approximately twice the fluid volume displaced by the second pumping finger. The first pinching finger occludes the tube upstream to the first pumping finger and the second pinching finger occludes the tube between the first and second pumping fingers. To monitor dimensional changes in the outer diameter of the tube and thereby indicate pressure inside the tube, the strain gauge is mounted on the pump between the second pinching finger and first pumping fingers. Finally, a leaf spring and photoelectric sensor are associated with the first pumping finger to indicate when the finger is in its fully withdrawn position.
110 Citations
23 Claims
-
1. A device for pumping fluid through a resilient tube which comprises:
-
a base; a platen mounted on said base for holding said tube; means mounted on said base for alternately squeezing said tube against said platen at a first and second location; means mounted on said base for alternately occluding said tube upstream from said first location and between said first and second locations, said first location being squeezed as said tube is occluded upstream from said first location; a strain gauge mounted on said base and operatively coupled with said tube at a third location thereon, for sensing fluid pressure in said tube at a first time when said tube downstream from said third location is open and at a second time when said tube upstream from said third location is open; photoelectric sensor means attached to said base for indicating a position of said squeezing means as it is pushed outwardly to a withdrawn position; and the pressure sensor operating in combination with the position sensor to provide a means for determining whether the device is delivering fluid at an acceptable rate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A device for pumping fluid through a resilient tube which comprises:
-
a base; a platen mounted on said base and adapted to hold said tube; a first pumping finger reciprocally mounted on said base to urge against said tube with movement between a withdrawn position and an extended position; a second pumping finger reciprocally mounted on said base to urge against said tube with movement between a withdrawn position and an extended position; means for moving said first pumping finger toward its said extended position as said second pumping finger is moved toward its said withdrawn position and moving said first finger toward its said withdrawn position as said second finger is moved toward its said extended position; a first valve mounted on said base for occluding said tube upstream from said first pumping finger as said first pumping finger moves toward its extended position; a second valve mounted on said base for occluding said tube between said first and second pumping fingers as said second finger moves toward its extended position; a strain gauge mounted on said base and operatively associated with said tube to alternately measure the outside diameter of said tube at a first time when said tube downstream from said gauge is occluded and at a second time when said tube upstream from said gauge is occluded; a photoelectric sensor for indicating a position of said first pumping finger as it is pushed outwardly to a withdrawn position; and the pressure sensor operating in combination with the position sensor to provide a means for determining whether the device is delivering fluid at an acceptable rate. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
-
18. A method for pumping fluid through a resilient tube which comprises the steps of:
-
mounting said tube on a platen; alternately squeezing said tube at a first location using a first pumping finger and at a second location using a second pumping finger; alternately occluding said tube upstream from said first location, and between said first and second locations; monitoring the fluid pressure at a fixed location of said tube with a strain gauge operatively coupled with said tube between said first and second locations, said strain gauge monitoring said pressure at a first time when said tube downstream of said gauge is open and at a second time when said tube upstream of said gauge is open; sensing a location of said first pumping finger using a photoelectric device; and operating the pressure sensor in combination with the position sensor to provide a means for determining whether the device is delivering fluid at an acceptable rate. - View Dependent Claims (19, 20, 21, 22, 23)
-
Specification