| 摘要 |
<p>The present invention is a positive displacement dispenser which is particularly useful in dispensing viscous material such as toothpaste. This dispenser has a longitudinally-extending housing which defines a chamber for material to be dispensed, a discharge orifice in the housing through which the material is dispensed from the chamber, a threaded rod having an axis extending through the chamber, a piston with a threaded opening mounted on the rod so that rotation of the rod moves the piston, and actuating lever pivotally mounted to the housing, and a rotatable wheel operatively coupling the threaded rod and the actuating lever so that depression of the actuating lever causes the wheel to turn the threaded rod and advance the piston. The rotatable wheel is coaxially-mounted to the threaded rod and has a plurality of pins mounted on a circular path surrounding the axis of the wheel. A drive bar is attached to the actuating lever such that depression of the lever causes the drive bar to engage one of the pins and rotate the wheel a fixed amount. A return spring which is also attached to the actuating lever returns the actuating lever to its oroginal and simultaneously urges the drive bar against and adjacent pin.</p> |
