# US 4,397,151 A · Heat engine

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- Number: US 4,397,151 A
- Document ID: US4397151A
- Status: Granted
- Kind: A
- Application number: 06/360,884
- Filed: 1982-03-22
- Granted: 1983-08-09
- Earliest claimed: 1982-03-22
- Inventors: Samuel S. Houlton
- Web page: https://patentgrep.com/patent/US4397151A

## CPC

- F03G 6/002: {with expansion and contraction elements}
- F03G 7/0614: {using shape memory elements}
- F03G 7/062: {characterised by the activation arrangement}
- F03G 7/0633: {performing a rotary movement}
- F03G 7/0641: {Motors; Energy harvesting or waste energy recovery}
- F03G: SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR (arrangements in connection with power supply in vehicles from force of nature B60K16/00; electric propulsion with power supply in vehicles from force of nature B60L8/00)

## Abstract

A pair of spooling means, such as cylinders, are rotatable about fixed and parallel axes. An elongated member with a planar surface moves in reciprocating motion essentially normal to the cylinder axes such that planar surface remains adjacent and essentially tangential to the cylinder walls. Nitinol bands annealed as straight lengths are fixed at their ends to the cylinder walls and the planar surface such that a portion of the bands become spooled or unspooled about each cylinder depending on the motion and position of elongated member. The motion of the elongated member is caused by application of heat energy to spooled cylinder causing its bands to stiffen and become straight and withdrawal of heat energy from unspooled cylinder causing its bands to become bendable.

## Claims

### Claim 1

In a heat engine with a source of heat energy and a means for alternately applying said heat energy for suitable periods of time, the improvement comprising:
(a) a first spooling means rotatable about a fixed axis,
(b) a second spooling means rotatable about a fixed axis, the axis of the second spooling means being substantially parallel to the axis of the first spooling means,
(c) an elongated member disposed essentially tangential to both spooling means with said member's longitudinal axis being substantially normal to the axes of the first and second spooling means, said member being operable to move a suitably limited distance along its longitudinal axis in a first direction and in a second and opposite direction,
(d) a first plurality of nitinol bands annealed as straight lengths and each being suitably fixed at one end to the first spooling means and at the other end to the elongated member such that when said member is moved in the first direction, said bands are spooled about said spooling means and when said member is moved in the second direction, said bands are unspooled from about said spooling means, and
(e) a second plurality of nitinol bands annealed as straight lengths and each being suitably fixed at one end to the second spooling means and at the other end to the elongated member such that when said member is moved in the second direction said bands are spooled about said spooling means and when said member is moved in the first direction, said bands are unspooled from about said spooling means, the heat energy being alternately applied to the first and second plurality of nitinol bands to cause operation of the engine.

### Claim 2 (depends on 1)

The heat engine of claim 1 wherein the first and second spooling means comprises a pair of cylinders of substantially equal diameter and the first and second plurality of nitinol bands are equal in number.

### Claim 3 (depends on 1, 2)

The heat engine of claim 1 or 2 wherein a runner means is used to guide the motion of the elongated member such that the planar surface remains in a plane essentially tangential to the first and second spooling means.

### Claim 4 (depends on 3)

The heat engine of claim 3 wherein the elongated member comprises a generally rectangular platform and wherein the runner means comprises a guide rail means and a bearing means.

### Claim 5 (depends on 1, 2)

The heat engine of claim 1 or 2 wherein a portion of each of said spooling means forms at least one gear means and wherein the planar surface of the elongated member has at least one longitudinally oriented gear track thereon, said gear means and gear track being aligned so as to mesh.

### Claim 6 (depends on 4)

The heat engine of claim 4 wherein a portion of each of said spooling means forms at least one gear means and wherein the planar surface of the elongated member has at least one longitudinally oriented gear track thereon, said gear means and gear track being aligned so as to mesh.

### Claim 7 (depends on 1, 2)

The heat engine of claim 1 or 2 wherein the nitinol bands comprise substantially 55% nickel and 45% titanium.