Peristaltic pump

Claim 2

A peristaltic pump comprising an elastically yieldable pipe having an inlet part and an outlet part for fluid to be pumped, means defining a support ramp in abutting relation to the pipe and imparting to the pipe a fixed configuration, at least three movable pressing elements, and drive means for causing the elements to travel around an axis in a closed path which encounters said configuration so as to compress the pipe and move away from the pipe alternately, the fixed configuration imparted tO the pipe by the ramp, the path of said elements and spacing between said elements being such that when the element which is the downstream element relative to the direction in which the fluid is pumped through the pipe moves away from the pipe an upstream element already closes the pipe and causes the fluid to progress as the downstream element causes a decompression of the pipe, the intermediate element located between the upstream element and downstream element progressively compressing the pipe so as to ensure an exact volumetric compensation, at each instant, of the decompression due to the downstream element by the compression due to the intermediate element.

Claim 3

A peristaltic pump comprising an elastically yieldable pipe having an inlet end and an outlet end for fluid to be pumped, means defining a support ramp combined with the pipe and imparting to the pipe a fixed configuration, means defining a rotor rotatable about an axis and located within said support ramp, at least three rolling elements rotatably mounted on the rotor in angularly evenly spaced relation to each other, rotation of the rotor causing said elements to rotate about said axis in a closed path, the support ramp having a configuration comprising two part-circular portions which have the same center on said axis and the same radius and subtend an angle of substantially 60* on said axis, a curved connecting portion tangent to the part-circular portions and interconnecting the part-circular portions and in which connecting portion the pipe does not meet the path of said elements, an inlet portion and an outlet portion respectively adjacent said inlet part and outlet part of the pipe and tangent to the part-circular portions, the radius of the part-circular portions being equal to the sum of the distance between said axis and the center of a rolling element plus the radius of the rolling element plus the thickness of the pipe when the pipe is completely flattened against the ramp by the rolling element.

Claim 4

A peristaltic pump comprising an elastically yieldable pipe having an inlet end and an outlet end for fluid to be pumped, means defining a support ramp combined with the pipe and imparting to the pipe a fixed configuration, means defining a rotor rotatable about an axis and located within said support ramp, at least three rolling elements rotatably mounted on the rotor in angularly evenly spaced relation to each other, rotation of the rotor causing said elements to rotate about said axis in a closed path, the support ramp having a configuration comprising two part-circular portions which have the same center on said axis and the same radius and subtend an angle of substantially 60* on said axis, a curved connecting portion tangent to the part-circular portions and interconnecting the part-circular portions and in which connecting portion the pipe does not meet the path of said elements, an inlet portion and an outlet portion respectively adjacent said inlet part and outlet part of the pipe and tangent to the part-circular portions, the radius of the part-circular portions being equal to the sum of the distance between said axis and the center of a rolling element plus the radius of the rolling element plus the thickness of the pipe when the pipe is completely flattened against the ramp by the rolling element.

Claim 5

A pump as claimed in claim 1, wherein said drive means are adapted to cause said elements to move alternately toward and away from the ramp which has a fixed substantially circular configuration.

Claim 6

A pump as claimed in claim 1, wherein said fixed configuration of the pipe is a sinusoid, said path having a rectilinear active part.

Claim 7

A pump as claimed in claim 1, wherein said configuration is rectilinear.

Claim 8

A pump as claimed in claim 2, further comprising a fixed ring gear having internal gear teeth and a gear pinion integral with each rolling element and in meshed relation to said ring gear.

Claim 9

A pump as claimed in claim 6, wherein said rolling elements are mounted on the rotor at equal distances from said axis.

Claim 10

A pump as claimed in claim 6, comprising a shaft for driving the rotor and a unidirectional coupling device drivingly connecting the shaft to the rotor.

Claim 11

A pump as claimed in claim 1, wherein said inlet part and outlet part of the pipe are transparent and a device for detecting particles is disposed on each side of said transparent parts.

Claim 12

A pump as claimed in claim 1, wherein said pressing elements are rotatable rollers.