In-situ overheat alert for equipment

Patent metadata

Field	Value
Publication number	US-9058729-B2
Application number	US-201213613032-A
Country	US
Kind code	B2
Filing date	Sep 13, 2012
Priority date	Sep 13, 2012
Publication date	Jun 16, 2015
Grant date	Jun 16, 2015

Abstract

Malfunction or failure of mechanical, electrical and electro-mechanical equipment, for example equipment used in manufacturing operations, is often preceded by an increase in the operating temperature of at least some portion of the equipment. A temperature-sensitive, active material-containing actuator is pre-selected to operate at a pre-determined temperature indicative of impending equipment failure and placed in thermal contact with the equipment. If the equipment achieves the pre-selected temperature the actuator signals this by displaying a flag or providing some other passive visual indication. Alternatively, or additionally, the actuator may issue an electrically-powered alert including visual or audible alerts or a wireless communication. Selected actuators are based on smart materials including shape memory alloys (SMA), shape memory polymers (SMP) and paraffin wax, all of which may be adapted to operate over a temperature range sufficient to encompass the expected range of pre-determined temperatures.

First claim

The invention claimed is:

1. A device for placement in thermal conduction contact with a machine, the device serving to detect and give notice of an over-heating condition in the machine when the machine is operating or has been operating; the device comprising:
a shaped body of an active material that is composed to experience a phase transformation, or undergo a glass transition, producing a shape, stiffness, or volume change when it is heated to a predetermined temperature, indicative of an over-heating condition in a machine when the device is placed in thermal conduction contact with the machine, the shaped body of active material being located in the device for heat transfer from the machine;
a flag-member with a surface area for displaying a visible indication of overheating in the machine, the flag-member being maintained in a stored position in the device when the machine is not in a over-heating condition, the flag-member being movable to an alarm-giving position by activation of the active material when the active material is heated to its predetermined temperature by thermal contact with the machine and experiences its shape-, stiffness-, or volume-changing phase transformation or glass transition.

2. The device as recited in claim 1 in which the device has a surface for surface-to-surface contact with a surface of the machine.

3. The device as recited in claim 1 in which the device further comprises a spring in contact with the flag-member and serving to move the flag-member to its alarm-giving position upon actuation of the heated active material.

4. The device as recited in claim 3 in which the device further comprises a member for holding the flag-member in its stored position against the force of the spring until the active material is heated to its predetermined temperature and is activated to move the holding member and enable the spring to move the flag-member to its alarm giving position.

5. The device as recited in claim 4 in which the device further comprises a member for stopping the flag-member in its alarm-giving position, the stopping member holding the flag-member against the force of the spring.

6. The device as recited in claim 4 in which the active material is a wire of shape memory alloy composition adapted to shorten its length when it is heated to a temperature indicative of an overheating condition in the operation of the machine, the shortening of the shape memory alloy wire activating the movement of the flag-member to its alarm-giving position.

7. The device as recited in claim 3 in which the flag-member has an edge that is pivotally connected in the device such that the flag-member is moved around its edge to its alarm-giving position by a spring upon actuation of the heated active material.

8. The device as recited in claim 7 in which the active material is a wire of shape memory alloy composition adapted to shorten its length when it is heated to a temperature indicative of an overheating condition in the operation of the machine, the shortening of the shape memory alloy wire activating the movement of the flag-member to its alarm-giving position.

9. The device as recited in claim 3 in which the device further comprises a member for stopping the moving flag-member in its alarm-giving position, the stopping member holding the flag-member against the force of the spring.

10. The device as recited in claim 1 in which the active material is a wire of shape memory alloy composition with a length, a portion of the wire length being held in thermal conduction contact with the machine, the shape memory alloy wire being adapted to shorten its length when it is heated to a temperature indicative of an overheating condition in the operation of the machine, the shortening of the shape memory alloy wire activating the movement of the flag-member to its alarm-giving position.

11. The device as recited in claim 10 in which the shape memory alloy composition is an alloy of nickel and titanium.

12. The device as recited in claim 10 in which the flag-member is manually resettable to its stored position upon cooling from an overheat condition.

13. The device as recited in claim 1 in which the flag-member is manually resettable to its stored position upon cooling from an overheat condition.

14. The device as recited in claim 1 in which the active material is a polymer composition in the shape of a sheet, the sheet of polymer composition shaped and adapted to respond to heat emanating from an operating machine by transitioning to a softened condition when it is heated to a temperature indicative of an overheating condition in the operating machine, the softened condition of the polymer composition sheet activating the movement of the flag-member to its alarm-giving position.

15. The device as recited in claim 14 in which the flag-member is manually resettable to its stored position upon cooling from an overheat condition.

16. The device as recited in claim 1 in which the active material is a body of organic paraffin composition, contained as a first volume at a temperature below the overheating temperature of the machine, the body of paraffin composition experiencing a volume increase when it is heated to a temperature indicative of an overheating condition in the operation of the machine, the volume increase of the paraffin composition being sufficient to activate the movement of the flag-member to its alarm-giving position.

17. The device as recited in claim 16 in which the device further comprises a piston that is actuated by a volume increase in the paraffin composition to move the flag-member to its alarm-giving position.

18. The device as recited in claim 16 in which the flag-member is manually resettable to its stored position upon cooling from an overheat condition.

19. The device as recited in claim 1 in which the device comprises an electrical connection that is activated by movement of the flag-member to its alarm-giving position to prompt issuance of a further alarm signal by a separate means, remote from the machine and the subject device.

20. The device as recited in claim 1 in which the device comprises an electrical connection that is activated by movement of the flag-member to its alarm-giving position to issue an alarm signal to a computer management system, remote from the machine and the subject device.

Assignees

• Johnson Nancy L
• Browne Alan L
• Menassa Roland J
• Gm Global Tech Operations Inc

Inventors

• Johnson Nancy L
• Browne Alan L
• Menassa Roland J

Classifications

• G08B5/02 Primary

  using only mechanical transmission · CPC title

• G01K1/02

  Means for indicating or recording specially adapted for thermometers · CPC title

• G08B21/187

  Machine fault alarms · CPC title

• G08B17/02

  Mechanical actuation of the alarm, e.g. by the breaking of a wire · CPC title

• G08B17/04

  Hydraulic or pneumatic actuation of the alarm, e.g. by change of fluid pressure · CPC title