Patent GB-1215586-A (GB)
Title: Pumping and cooling unit
IPC: F04B43/06
Filed: 1967-08-25
Abstract: 1,215,586. Reciprocating pumps. PILKINGTON BROS. Ltd., W.F. BOYLETT, J. W. HILL, T.B. LEAMON and G. SHAW. Aug.21, 1968 [Aug. 25, 1967], No.39195/67. Heading F1A. [Also in Division F4] A cooling system comprises a sealed vessel 50 containing a refrigerant, e.g. solid CO 2 , a coolant circuit including a passage 52 in heat exchange relationship with vessel 50, a reciprocating pump 10 in the coolant circuit, a line 40 for conveying refrigerant vapour from vessel 50 to means D for reciprocating the pump, and valve means 23 in line 40, the valve means being cyclically operated between two settings corresponding to induction and delivery strokes of the pump. As shown in Fig. 1, the pump 10 comprises a chamber 11 with a coolant inlet 13 and outlet 14, and a diaphragm 12 which is connected to one end of a rod 16 the other end of which is connected to a piston 17 movable within a cylinder 18. Valve means 23 comprises two rotary valves 28, 29 connected in parallel to line 40 and having a common actuating member 38 which is moved by a striker plate 43 on rod 16. Thus when rod 16 reaches its uppermost position, plate 43 actuates the valves so that refrigerant vapour is supplied through valve 28 and line 21 to the space 19 above piston 17 and the space 20 below the piston is connected to exhaust via line 22 and valve 29. The rod is therefore moved downwardly and when it reaches its lowermost position plate 43 reverses the valve settings to move the rod upwardly. The coolant circuit includes passages 56 in a protective suit 55 and the entire system may be portable. The coolant may be water containing an anti-freeze agent and a liquefied gas may be used in place of solid CO 2  in vessel 50. In an alternative embodiment Fig.3, (not shown) the pumping chamber has a concave surface and the diaphragm activating rod has a correspondingly convex end surface. The rod is arranged to actuate two valves which control the flow of refrigerant vapour to opposite ends of a slide valve. The latter moved between two end positions in which vapour is respectively supplied to opposite sides of the driving piston. In the embodiment shown in Fig. 4, the pump unit comprises a housing 159, a rod 161, discs 162, 163 secured to opposite ends of the rod and respective diaphragms 164, 165 secured to the discs and housing to define an upper pumping chamber, an intermediate chamber having an outlet 179 to atmosphere and a lower driving chamber. A spring 180 urges the rod 161 downwardly for the induction stroke while the driving chamber is connected to exhaust via a slide valve 182, and the upward discharge stroke is performed by moving valve 182 to admit vapour from line 190 to the driving chamber. Valve 182 is moved by virtue of the fact that in the extreme position of rod 161 seals 167, 169 on the discs close ports 171, 170 to prevent flow through respective conduits 204, 200 which are connected to line 190. Branch lines 201, 205 connect conduits 200, 204 to opposite ends of the slide valve, the arrangement being such that when vapour flows through conduit 200 or 204 the pressure transmitted by line 201 or 205 is insufficient to move the valve but is sufficient for this purpose when the associated conduit is blocked.