| 摘要 |
2130582 9316955 PCTABS00025 The trigger operated pumping mechanism (49) for a fluid dispensing device (10) comprises: a body (14) having a hollow cylinder (48) therein for receiving a piston (42), the hollow cylinder (48) extending to a fixed back wall (326) in the body (14), the cylinder (48) having a fluid inlet valve (330) and a fluid outlet valve (336) associated with the back wall (326); the valves (330 and 336) being pressure controlled; the inlet and outlet valves (330 and 336) are first and second plastic flap valves (330 and 336) which are each positioned opposite an opening (332 and 334) in or adjacent to the back wall (326) of the cylinder (48) and by making the remaining space between the back wall (326) and the movable wall (328) at the end of the ejection stroke of the piston (42) as small as possible, thereby to facilitate the creation of high vacuum and high pressure during intake and ejection strokes of the piston (42) and to facilitate priming with a minimum of strokes.
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