US 6,199,664 B1Granted

Spring motor for generating constant torque

AssigneeGeneral Electric Company

InventorsJohn Eric Tkaczyk, Jerome Johnson Tiemann

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Abstract

A spring motor for driving an electric power generator with constant power includes a crank-up spool, a take-up spool, and a relatively wide, flat tape spring which winds in a relaxed condition on the take-up spool. In one form, the spring has a width which varies approximately linearly from one end to another end so as to generate a constant torque at a fixed radius from an axis of the crank-up spool as the spring unwinds. In another form, the spring width is constant and a separate drum is driven by contact with the unwinding spring, with the separate drum driving an output shaft. In still another form, an idler wheel is driven by contact with the spring and the output shaft is driven from the idler wheel through gear contact with the periphery of an output drum mounted on the output shaft.

Claims7

Dependent claims

A spring motor for delivering constant power to a load, the spring motor comprising:

a crank-up spool and a take-up spool;
a flat, tape spring pre-treated to wind normally in a relaxed configuration about said take-up spool;
means for winding said spring in a reverse, tensioned configuration on said crank-up spool with at least one end of said spring being attached to said take-up spool, whereby release of said winding means allows said spring to unwind from said crank-up spool and rewind onto said take-up spool;
an idler shaft coupled in driven relationship to said spring whereby transfer of said spring from said crank-up spool to said take-up spool causes rotation of said idler shaft;
an idler wheel attached to said idler shaft and positioned in frictional engagement with said spring;
and
a plurality of uniformly spaced notches in said spring, said idler wheel including means for engaging said notches to establish a positive driving relationship between said spring and said shaft.

4 more elements

Dependencies are inferred from the claim text.