| 摘要 |
<p>An adjustable, battery-powered, constant pressure gun for dispensing viscous materials such as caulk and adhesive. The gun includes a housing having a handle, an operator-actuated trigger, and a battery compartment with power supply terminals. A motor mounted within the housing drives a dispensing mechanism. The flow of current through the motor is controlled by an electronic switch. A current-to-voltage converter including a low-pass filter is coupled to the motor and provides a feedback pressure signal representative of the actual dispensing pressure as a function of the current drawn by the motor. A set-point voltage signal representative of a desired dispensing pressure is provided by an operator-adjustable pressure control. A hysteresis comparator connected to the electronic switch compares the feedback pressure signal to the set-point signal, and controls the switch as a function of the comparison to maintain the actual dispensing pressure within a predetermined operating band of the desired dispensing pressure when the trigger is actuated.</p> |
