Plunger operated dispensing device.

摘要

A plunger-operated dispensing device for liquids comprises a stock container (1) for a liquid, at least one dispensing cylinder (2) with a dispensing plunger (3) therein which can be moved in the axial direction between two end postions. One side of the cylinder (3) is in communication with the stock container (1) via a channel (7) having a shut-off valve (8) therein which can be operated. The outside diameter of the dispensing plunger (3) is smaller than the inside dia­meter of the dispensing cylinder (2) so that a certain space (15) is present between the wall (14) of the cy­linder (2) and the plunger (3). Near the end which is situated at the side of the end (12) of the dispen­sing cylinder (2) which is in communication with the stock container (1) the dispensing plunger (3) is pro­vided at the circumference with sealing means (16) for sealing the space (15) between the cylinder wall (14) and the plunger (3). Adjustment means are present for displacing the movement stroke of the dispensing plunger (3) so far in the direction of the end (12) of the dispensing cylinder (2) which is in communication with the stock container (1) that in one of the end positions of the plunger (3) the sealing means (16) of the plunger (3) reach past the end (12) of the dis­pensing cylinder (2) which is in communication with the stock container.

With this construction it is possible to feed cleaning liquid from the stock container (1) via the communication channel (7) and past the shut-off valve (8) to the space between the dispensing plunger (3) and the wall of the dispensing cylinder (2), as a result of which a thorough cleaning of all the components becomes possible without the dispensing device having to be dismantled.