Rodless dispenser

摘要

A dispenser for viscous, extrudable materials uses a sprocket-driven push chain that is drawn from a chain magazine responsive to actuation of a user trigger. The sprocket for the chain is driven by a toothed wheel, which is driven by a first, ratcheting drive pawl, which is actuated by the trigger. A second ratcheting locking pawl prevents the toothed wheel and hence the chain sprocket from rotating backward when the trigger is released. A single “button” or actuator can be actuated by one hand of a user while the user's other hand grasps a chain retractor to pull an extended chain back to a starting position whereat the dispenser can be reloaded.

主权项

1. A dispenser comprising:
a first pawl coupled to a first axle and configured to engage and disengage notches on a toothed wheel coupled to a second axle responsive to angular translation of the first pawl about the first axle, the first pawl being configured to drive the toothed wheel in a first direction responsive to engagement of the first pawl with a notch in the toothed wheel and angular translation of the first axle around the second axle in said first direction; a second pawl coupled to a third axle, the second pawl having first and second portions, both of which extend away from the third axle, the first portion extending from the third axle toward the toothed wheel and configured to engage and disengage notches in the toothed wheel responsive to rotation of the second pawl around the third axle, the first portion being biased to engage notches on the toothed wheel, the first portion capable of being disengaged from the notches responsive to a force applied to the second portion of the second pawl; the first pawl, toothed wheel and second pawl being configured such that engagement of the first end of the second pawl with notches in the toothed wheel allows the toothed wheel to be driven in the first direction by the first pawl but prevents the toothed wheel from rotating in an opposite second direction, disengagement of the first end of the second pawl from the toothed wheel responsive to a force applied to second end of the second pawl also causes the first pawl to disengage from the toothed wheel and thereby allows the toothed wheel to rotate in the second direction; and an actuating trigger having first and second opposing ends, the first end being rotatably coupled to the first axle and including an arm configured to support the second axle, the actuating trigger configured to translate between first and second angular positions relative to the first axle and thereby cause the second axle to translate around the first axle between the first and second angular positions.