Pressing plate for linearized pulses from a peristaltic pump
First Claim
1. A peristaltic pump comprising a rotatable drum including compressing elements around its periphery, a flexible tube extending between two spaced supports and a movable presser plate for holding the tube against the periphery of the drum between the two spaced supports such that on rotation of the drum the compressing elements squeeze the tube against the presser plate for moving fluid through the tube, said presser plate having a pinch region having a surface of curvature Ro wherein said tube is squeezed to a condition of closure and an expansion region of said plate having a variable curvature R such that R=(KRo)A where A is the angular rotation of said drum within said expansion region thereby producing a linear expansion of said flexible tube and the arcuate length of said expansion region being greater than that of said pinch region, wherein at least one of the tube supports is movable relative to the drum to establish an operative and an inoperative position for the tube, the operative position being when the tube is positioned for pumping.
2 Assignments
0 Petitions
Accused Products
Abstract
A peristaltic pump comprises a rotatable drum 2 having rollers 5 or cams 5'"'"' for squashing a flexible tube 9 against a profiled surface 10 of a presser plate 7. Tube 9 is mounted between supports 14 and 15 on presser plate 7 and is automatically movable between an inoperative and operative (pumping) position by pivotal movement of plate 7 about axis 8 produced by an electro mechanical actuator. A flexible membrane 33 is sandwiched between rollers 5 or cams 5'"'"' for eliminating shear forces on the tube 9. The construction of the pump and shape of profile 10 are such as to mimimise pulsations in the output flow. Systems for supplying a sample for analysis to spectroscopic apparatus using the peristaltic pump are also described.
97 Citations
11 Claims
- 1. A peristaltic pump comprising a rotatable drum including compressing elements around its periphery, a flexible tube extending between two spaced supports and a movable presser plate for holding the tube against the periphery of the drum between the two spaced supports such that on rotation of the drum the compressing elements squeeze the tube against the presser plate for moving fluid through the tube, said presser plate having a pinch region having a surface of curvature Ro wherein said tube is squeezed to a condition of closure and an expansion region of said plate having a variable curvature R such that R=(KRo)A where A is the angular rotation of said drum within said expansion region thereby producing a linear expansion of said flexible tube and the arcuate length of said expansion region being greater than that of said pinch region, wherein at least one of the tube supports is movable relative to the drum to establish an operative and an inoperative position for the tube, the operative position being when the tube is positioned for pumping.
Specification