Fluid delivery apparatus

Claim 2

An apparatus according to claim 1, in which each of the first end chamber and the second end chamber is defined by an inner side wall of substantially circular cross-section, the first end chamber is disposed at a right angle to the second end chamber, each of the piston means is a spring-actuated plunger, and the closure means comprises two lockable caps, each one engageable at the open distal end of each end chamber.

Claim 3

An apparatus according to claim 1, in which each of the first end chamber and the second end chamber is defined by an inner side wall of substantially circular cross-section, the first end chamber is parallel to the second end chamber, each of the piston means is a spring-actuated plunger, and the closure means comprises a snap fit lockable cap (26) engageable over the open ends of both end chambers.

Claim 4

An apparatus according to claim 1, in which the first piston means comprises a first cup-shaped head (29) mounted within the first en chamber and the second piston means comprises a second cup-shaped head (29) mounted within the second end chamber, each of said heads having a substantiall circular cross-section and a periphery which fits snugly within the corresponding end chamber to form a fluid-tight slidable seal with the inner side wall of the end chamber the inner surface of the head defining a movable wall of the central chamber, each cup shaped head being actuated by compressed air at a predetermined pressure from a single source; and the closure means comprises two screw caps, each having an inle port (32) to receive an air line (31) to deliver air from the source to the corresponding end chamber and each being screwable on to the outer open end of the end chamber

Claim 5

An apparatus according to claim 1, in which the housing (1) has an elongated hollow bore with a longitudinal axis and includes three chambers comprising a first end chamber (2) and a second end chamber (3), each chamber defined by an inner side wall (4) of substantially circular cross-section and terminating in an outer open end (5), an integral connecting central chamber (6) between the two end chambers and defined by an inner side wall (7) of smaller cross-sectional area than that of each of the end chambers; the inlet port (8) is located in the side wall of the central chamber and the outlet port (9) is located in the side wall of the central chamber diametrically opposite the inlet port, each of the inlet port and outlet port being associated with a valve (10, 11) located outside the housing for opening and closing the respective port; the first piston means comprises a first spring-actuated plunger (12) mounted within the first end chamber and the second piston means comprises a second spring-actuated plunger (13) mounted within the second end chamber, each of said plungers comprising a head having a substantially circular cross-section and a periphery which fits snugly within the corresponding end chamber to form a fluid-tight slidable seal with the inner side wall of the end chamber, the inner surface (14) of the head defining a movable wall of the central chamber, and an outwardly extending stem (15) having a proximal end (16) and a distal end (17), which stem is co-axial with the longitudinal axis of the bore and is accommodated within a helical compression spring (18), the proximal end of each stem being integrally connected to the outer surface of the head of the corresponding plunger; and the closure means comprises two screw caps (19, 20), each having a central hole (21) and each being screwable on to the outer open end of an associated end chamber wherein the thread on each open end of the housing and the thread on each associated screw cap is such that the closure by the caps provides end chambers of substantially equal volume, and each central hole accommodates the distal end (17) of the stem of the plunger mounted within the corresponding end chamber so that, upon compression or relaxation of the spring, the stem is slidable relative to the central hole.