| 摘要 |
1470597 Manually operated reciprocating pumps STERLING-WINTHROP GROUP Ltd 21 Aug 1975 [21 Aug 1974] 36836/74 Heading F1A A reciprocating pump for dispensing pastes and liquids, e.g. soap, comprises a piston 6 manually movable in a cylinder 4 against the action of a spring 10, the piston 6 being provided with a reduced diameter and 15 on which slides a sleeve valve 16 for controlling the filling and emptying of a working chamber 29. In the position shown fluent material in a storage container 1 enters the working chamber 29 through an orifice 22 in the cylinder 4 and an inlet port 28 in the piston 6. On depression of a head 8 the piston 6 moves while the sleeve 16 remains stationary due to the friction between a seal 18 and the cylinder 4. Fluent material is therefore forced back into the container 1 until the inlet port 28 is closed and an outlet port 32 is opened. At this point a shoulder 26 on the piston engages the end 17 of the sleeve 16 and the piston 6 and sleeve 16 move together, thereby expelling the contents of the chamber 29 through an outlet passage 34, 36. During the initial part of the return stroke under the action of the spring 10, material is sucked back through the passage 36, 34 until the outlet port 32 is closed. A retainer 20 engages the sleeve during the remainder of the return stroke. A screw (not shown) through the end of the cylinder 4 or a screw 12 co-operating with a sloping surface 14 is adjustable to alter the stroke. |
