Electric powered lift with load control
OwnerFranklin C. Bradshaw, Craig Churchillinventors
Life of this patent
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Abstract
A lifting device utilizing a utility winch having an electric motor and cable drum. The cable on the cable drum extends around a pulley located on a load cell beam. Excessive loads will deflect the load cell beam causing a contact on a micro switch to be engaged to shut off power to the motor. The cable is attached to a trolley which reciprocates along a mast between upper and lower limits. The trolley includes a brake which has a drum which engages the mast to stop in travel of the trolley in the event of a cable breakage. Cable tension is also sensed and cable slack will actuate a switch to interrupt power to the electric motor. Various load handling attachments are detachably securable to the trolley.
Claims11
A lift comprising:
- (a) a base;
- (b) a vertical mast extending from the base;
- (c) a mounting plate on said mast;
- (d) a winch on said mounting plate having an electric motor powering a cable drum having an attached cable;
- (e) an electrical circuit connected to operate said electric motor;
- (f) a trolley reciprocable along said mast;
- (g) a load cell having a deflectable beam
- (h) a cable pulley on said beam, said cable extending around said pulley and operably connected to said trolley;
- and
- (i) a first switch in said electrical circuit and located adjacent the beam so that predetermined deflection of said beam will engage said switch to interrupt the power to said electric motor.
Dependencies are inferred from the claim text.