US2337084A - Rotary heat motor - Google Patents

Description

Dec. 21, 1943. G. w. CRISE ROTARY HEATMOTOR Filed Aug. 2, 1194i) H oo IN VE N TUR Patented Dec. 21, 1943 UNITED STATES PATENT OFFICE ROTARY HEAT MOTOR George W. Crise, Mount Vernon, Ohio Application August 2, 1940, Serial No. 349,791

1 Claim.

The principal object oi my invention is to provide a simple and inexpensive slow speed motor for the operation of animated signs directly from the heat of the lamp used in lighting the sign.

Additional and important applications being the operation of displays, timers, switches, toys, water circulators and all other small power applications where it is desired to obtain slow speed motion from a heat source.

Another object oi my invention is to provide a dependable power source by eliminating such trouble producing parts as windings, high speed bearings and gears, and at the same time produce a silent motor whose torque increases as the motor is slowed down by any form of overlo-ad.

A further object of my invention is to produce a heat motor whose commutation, or timing, is accomplished by carrying the propellin T element through the heating zone by mounting it on a single rotating member which revolves through tw-o different temperature zones.

A siinpie embodiment of my invention uses a strip of thermostatic bimetal spirally coiled within a pivoted ring, the outer end oi the bimetal being attached te the ring and the inner end by a bearing to the offset throw of a crank shaft, on the central end of which shaft the ring rotates. A light bulb supplies heat to one side of the bimetal coil causing it to distort throwing tension on the crank at right angles to the heat source, resulting in rotation of the ring and bimetal spiral which carries other sections oi the bimetal into the heated zone with recurring action and consequent continuous rotation.

The operation of my motor will be more clearly understood by referring to the accompanying drawing, in which i is a pivoted frame ring 1n section, 2 a pivot hub member, shown in section, joined by the spokes 3, 4, and 5 to ring l, and carrying hardened cup point set screw 6 to act as a pivot bearing.

l' is a crank shaft whose Central throw 1s pointed to carry bearing 6, and is supported by post 3 which in turn is manually rotatable 1n base 9. tsl, il, and I2 are consecutive cous of a thin bimetal spiral, shown in section, which 1s fastened to frame ring I by rivet !3, and by rivet ifi to a crank bearing l5. IS is a source of heat and light, Il is a combination reflector and heat bale.

IS is a transparent cylinder, shown 1n section, on which Iii, 2i?, and 2l are irregular light varying and intercepting streaks.

22 is a screen on which are translucent designs 23, 24, and 25 so placed as to be in the path of light passing through cylinder I8. 26 is a knurled sleeve for rotating the crank 'I and post 8 in base S to control the motor speed and direction.

rom the foregoing it will be observed that the reflector baille I'I divides the space within the cylinder I8 into two Zones, one of which is occupied by the lamp i which when lighted causes a draft of hot air to rise through the section of bimetal spiral I0, II, and I2 directly over it.

It will also be obvious that this rising hot air will induce a draft of cool air through the opposite side of the same bimetal spiral Ill, I I, and I`2, by the well-known suction action of warm air currents in chimneys.

Now it is well known in the art that if a bimetal spiral be uniformly heated or cooled, it will tend to wind or unwind concentrically because of the uniform bending action of all the bimetal, but if one side of the spiral be heated more than the other, the bending tendency will be greatest in the section of greatest temperature change, which will result in the spiral becoming eccentric.

Since the bimetal spiral I0, II, and I2 is secured to ring I by rivet I3, the only way it can become eccentric is by moving the central turn of bimetal at I2, and since I`2 is attached to crank l by crank bearing I5 it will be obvious that pressure will be exerted on crank 'I at approximate right angles to the heated section of bimetal I0, II, and I2, which is above lamp I6.

Since this pressure is out of line with the axis of rotation of ring I, which is free to rotate on the central point of crank shaft 'l at cup bearing 6, the entire motor and cylinder assembly will revolve, carrying the already heated bimetal section away from lamp I5 and into the cool draft rising on the opposite side of heat bailie I'I.

In this way a continually recurring distortion of the bimetal at right angles to the heating Zone will hold pressure on crank I producing continuous rotation of the motor.

It will also be observed that by rotating post 8 by knurled sleeve 25, theposition of motor bearing 6 with respect to crank I and heat source can be adjusted to any relation, thereby causing the bimetal distortion which is always at approximate right angles to the heating zone, to produce rotation in either direction, or by adjusting it to a neutral position, motor may be stopped. By adjusting the crank to various angles between the neutral and maximum torque form of heat responsive distorting member by revolving it through zones of diierent temperature.

What I claim is:

In combination a source of heat and a bimetal spiral rotatably mounted adjacent to said heat source, a stationary crank associated with said bimetal whereby its bending action Will be transferred into torque when different sections of said 10 bimetal are carried to and from said heat source.

GEORGE W. CRISE.

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