Diaphragm Pump

Abstract

A disposable pump has a pump unit 4 engaging with a drive unit 6. The drive unit drives a piston 18. The pump has an internal chamber having a flexible wall which engages with the piston 18 to allow a snap fit. The pump unit 4 is manufactured out of only three mouldings, one being the flexible wall which forms in part the membrane or diaphragm of the pump, sandwiched between upper and lower units 50,70.

1 . A disposable pump unit for engagement with a drive unit, the drive unit including a piston driven by a drive unit, the disposable pump unit comprising:
 an internal chamber having a flexible wall,   a pump inlet in communication with the internal chamber through an inlet one-way valve;   a pump outlet in communication with the internal chamber through an outlet one-way valve;   
       wherein:
 the disposable pump unit further comprises detent extensions for engaging in a snap fit with the drive unit to form a snap fit unit; and 
 further comprising a gripping part formed on the flexible wall arranged to mate with the piston when the disposable pump unit is engaged in a snap fit with the drive unit. 
 
     
     
         2 . A disposable pump according to  claim 1  wherein the disposable pump unit comprises:
 a rigid housing made up of an outer unit and an inner unit defining the internal chamber between the outer unit and the inner unit; and 
 a flexible diaphragm between the inner unit and the outer unit, the flexible diaphragm defining the flexible wall. 
 
     
     
         3 . A disposable pump according to  claim 2  wherein the detent extensions are legs extending from the outer unit past the inner unit for engagement with the drive unit. 
     
     
         4 . A disposable pump according to  claim 1  wherein the gripping part is a separate rigid part mounted on the flexible wall. 
     
     
         5 . A disposable pump unit according to  claim 1  wherein the disposable pump unit is formed of an outer unit, an inner unit and a diaphragm unit between the outer unit and the inner unit, wherein the internal chamber is defined in the outer unit and the flexible wall and gripping part is an integral part of the diaphragm unit. 
     
     
         6 . A disposable pump unit according to  claim 2 , wherein
 the inlet one-way valve comprises an inlet tongue integrally formed in the diaphragm unit; and   the outlet one-way valve comprises an outlet tongue integrally formed in the diaphragm unit.   
     
     
         7 . A disposable pump unit according to  claim 2 , wherein
 the outer unit comprises an inlet channel between the internal chamber and the inlet valve, the outlet channel communicating with an inlet valve chamber in the outer unit facing an inlet channel in the inner unit in communication with the pump inlet, the inlet tongue in flexible engagement against the inlet channel to provide a one-way valve action; and   the outer unit comprises an outlet channel between the internal chamber and the inlet valve, the outlet channel communicating with an outlet channel end in the outer unit facing an outlet valve chamber in the inner unit in communication with the pump outlet, the outlet tongue in flexible engagement against the end of the outlet channel to provide a one-way valve action.   
     
     
         8 . A disposable pump unit according to  claim 2  wherein the detent extensions are legs extending from the outer unit past the inner unit for engagement with the drive unit. 
     
     
         9 . A two-part pump comprising
 a disposable pump unit and   a drive unit comprises a piston;   wherein the disposable pump unit comprises:   an internal chamber having a flexible wall,   a pump inlet in communication with the internal chamber through an inlet one-way valve;   a pump outlet in communication with the internal chamber through an outlet one-way valve;   detent extensions for engaging in a snap fit with the drive unit to form a snap fit unit; and   a gripping parts integrally formed on the flexible wall arranged to mate with the piston when the disposable pump unit is engaged in a snap fit with the drive unit; and   the drive unit further comprises a motor for driving the piston in the drive unit in reciprocating action.   
     
     
         10 . A two-part pump pump according to  claim 9  wherein the disposable pump unit comprises:
 a rigid housing made up of an outer unit and an inner unit defining the internal chamber between the outer unit and the inner unit; and 
 a flexible diaphragm between the inner unit and the outer unit, the flexible diaphragm defining the flexible wall. 
 
     
     
         11 . A two-part pump pump according to  claim 10  wherein the detent extensions are legs extending from the outer unit past the inner unit for engagement with the drive unit. 
     
     
         12 . A two-part pump pump according to  claim 9  wherein the gripping part is a separate rigid part mounted on the flexible wall. 
     
     
         13 . A two-part pump according to  claim 9 , wherein the drive unit includes holes for engagement with the detent extensions of the disposable pump unit. 
     
     
         14 . A two-part pump according to  claim 9  wherein the drive unit includes a recess and the disposable pump unit includes a boss having an opening, the boss being in engagement with the recess when the detent extensions grip the disposable pump unit to locate the disposable pump unit on the drive unit. 
     
     
         15 . A two-part pump according to  claim 9  wherein the piston passes through the opening into a mounting chamber holding the gripping unit when the detent extensions grip the disposable pump unit. 
     
     
         16 . A two-part pump according to  claim 9 , wherein the gripping part is in the form of a socket and the piston has an end shaped to releasably mate with the socket. 
     
     
         17 . A two-part pump according to  claim 16  wherein the end of the piston has a ball arranged to mate with a spherically socket as the gripping part. 
     
     
         18 . A two-part pump according to  claim 9  wherein the one of the gripping part and the end of the piston includes a magnet and the other of the gripping part and the end of the piston includes a magnetic material so that the gripping part and the end of the piston form a magnetic coupling.