| 摘要 |
<p>A dispensing device (10) is described which is a pump for dispensing accurately metered amount of fluids in the form of a spray. The device has a piston (30) sliding in a cylinder (23). A fluid inlet to the cylinder is normally closed off by a ball valve (26) and an outlet through the piston is normally closed off by a ball valve (33) and, when open, communicates with an outlet passage (38) leading to a swirl chamber (39) and outlet nozzle (40). Co-operating first and second cam surfaces (24, 49) are provided on parts fixed to the cylinder and piston respectively so that relative rotational movement of the cam surfaces causes the piston to slide in the cylinder, the stroke being fixed by the profiles of the cam surfaces.</p> |
