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US5463233A Expired / Lapsed US ⏱️ 0.0 years remaining

Micromachined thermal switch

Assignee: Honeywell International Inc
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Filing: 1993-06-23
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Granted: 1995-10-31
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Expires: 2013-06-23
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Abstract

Abstract A monolithic micromachined temperature switch obviates the necessity of assembling discrete components and also allows the temperature switch to be disposed in a relatively small package. In one embodiment of the invention, the temperature switch includes a bimetallic element operatively coupled to a pair of electrical contacts. In order to minimize contact wear due to contact arcing, a biasing force such as an electrostatic force is applied to the switch which provides snap action of the electrical contacts in both the opening and closing directions which enables the temperature set point to be adjusted by varying electrostatic force biasing voltage. In an alternate embodiment of the invention, the biasing force for providing the snap action effect can be eliminated by substituting the movable contacts with a field effect transistor with a movably mounted gate terminal. With such an arrangement since little or no current would normally flow through the gate terminal, the need to reduce contact arcing normally resulting from contact bounce would thus be eliminated. Thus, in such an embodiment, a biasing force such as an electrostatic biasing force is not necessary unless a snap action with hysteresis is desired. In alternate embodiments of the invention, the temperature switch may be formed with an integral power transistor for switching relatively large currents. The temperature switch may also be provided with an integrally formed capacitor for reducing the effects of switching inductive loads, such as relays and the like.

Inventors

  • 👤 Brian L. Norling

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 18:47
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/66; H10D64/68; H10D64/687; H01; H01H; H01H1/00; H01H1/0036; H10D30/00; H10D30/60; H10D30/63; H01H1/12; H01H1/14; H01H1/20; H01H2001/0042; H01H37/00; H01H2037/008; H01H59/00; H01H59/0009; H01H2059/0081; H01H37/02; H01H37/60; H01H9/00; H01H9/54; H01H9/547

Claims Analysis

Total Claims: 34
Claim 1
Independent Claim 95 words
A temperature switch comprising: a sensing element which includes a bimetallic strip, said sensing element adapted to be displaced as a function of temperature defining a first stable position and a second stable position; means for biasing said sensing element and causing said sensing element to be unstable between said first stable position and said second stable position, wherein said biasing means includes means for applying an electrostatic force to said sensing element; and means, operatively coupled to said sensing element, for providing signals indicative of said first stable position and said second stable position.
Claim 2
Dependent Claim 95 words
A temperature switch comprising: a sensing element which includes a bimetallic strip, said sensing element adapted to be displaced as a function of temperature defining a first stable position and a second stable position; means for biasing said sensing element and causing said sensing element to be unstable between said first stable position and said second stable position, wherein said biasing means includes means for applying an electrostatic force to said sensing element; and means, operatively coupled to said sensing element, for providing signals indicative of said first stable position and said second stable position.
Claim 3
Dependent Claim 22 words
A temperature switch as recited in claim 1 wherein said switch is configured to provide squeeze film damping of said sensing element.
Claim 4
Dependent Claim 17 words
A temperature switch as recited in claim 1, wherein said providing means includes a pair electrical contacts.
Claim 5
Dependent Claim 16 words
A temperature switch as recited in claim 1, further including means for coupling said biasing means.
Claim 6
Dependent Claim 56 words
A temperature switch as recited in claim 4, wherein said switch includes means for coupling said biasing means and sensing element and wherein said sensing element and said providing means are formed as a monolithic chip, said monolithic chip further includes integrally formed means operatively coupled to said providing means for switching relatively large electrical currents.
Claim 7
Dependent Claim 16 words
A temperature switch as recited in claim 5, wherein said switching means includes a power transistor.
Claim 8
Dependent Claim 16 words
A temperature switch as recited in claim 6, wherein said power transistor is a bipolar transistor.
Claim 9
Dependent Claim 17 words
A temperature switch as recited in claim 6, wherein said power transistor is a field effect transistor.
Claim 10
Dependent Claim 26 words
A temperature switch as recited in claim 4, wherein said monolithic chip includes integrally formed means for protecting said providing means during switching of inductive loads.
Claim 11
Dependent Claim 15 words
A temperature switch as recited in claim 9, wherein said protecting means includes a capacitor.
Claim 12
Dependent Claim 101 words
A monolithic temperature switch comprising: means for sensing temperature adapted to be displaced as a function of temperature between a first position and a second position; means operatively coupled to said sensing means for providing an electrical signal as a function of temperature; and means for biasing said sensing means, wherein said biasing means includes means for applying a non-linear force to said sensing means and wherein said non-linear force is proportional to the square of the distance of said sensing means from said first position; and said sensing means and said providing means are integrally formed on a monolithic chip.
Claim 13
Dependent Claim 101 words
A monolithic temperature switch comprising: means for sensing temperature adapted to be displaced as a function of temperature between a first position and a second position; means operatively coupled to said sensing means for providing an electrical signal as a function of temperature; and means for biasing said sensing means, wherein said biasing means includes means for applying a non-linear force to said sensing means and wherein said non-linear force is proportional to the square of the distance of said sensing means from said first position; and said sensing means and said providing means are integrally formed on a monolithic chip.
Claim 14
Dependent Claim 17 words
A monolithic temperature switch as recited in claim 11, wherein said non-linear force is an electrostatic force.
Claim 15
Dependent Claim 15 words
A monolithic temperature switch as recited in claim 11, wherein said applying means is adjustable.
Claim 16
Dependent Claim 34 words
A monolithic temperature switch as recited in claim 11, further including means for switching relatively large electrical currents electrically coupled to said providing means and integrally formed as part of said monolithic temperature switch.
Claim 17
Dependent Claim 17 words
A monolithic temperature switch as recited in claim 14, wherein said switching means includes a power transistor.
Claim 18
Dependent Claim 39 words
A monolithic temperature switch as recited in claim 11, further including means for protecting said providing means from damage due to inductive electrical loads connected to said providing means integrally formed as a part of said monolithic temperature switch.
Claim 19
Dependent Claim 22 words
A monolithic temperature switch as recited in claim 16, wherein said protecting means includes a capacitor electrically coupled to said providing means.
Claim 20
Dependent Claim 28 words
A monolithic temperature switch as recited in claim 11, further including means for forcing said sensing means to be unstable between said first position and said second position.
Claim 21
Dependent Claim 27 words
A monolithic temperature switch as recited in claim 11, further including means for substantially eliminating contact arcing during transactions between said first position and said second position.
Claim 22
Dependent Claim 28 words
A monolithic temperature switch as recited in claim 17, further including means for applying a force to said providing means in said first position or said second position.
Claim 23
Dependent Claim 27 words
A monolithic temperature switch as recited in claim 17, further including means for preventing transition of said providing means resulting from external forces of a predetermined magnitude.
Claim 24
Dependent Claim 22 words
A monolithic temperature switch as recited in claim 11, further including means for adding hysteresis to said displacement of said sensing means.
Claim 25
Dependent Claim 29 words
A monolithic temperature switch as recited in claim 11, wherein said providing means includes a field effect transistor (FET) with a movably mounted gate terminal forming said sensing means.
Claim 26
Dependent Claim 33 words
A monolithic temperature switch as recited in claim 23, wherein said providing means is adapted to provide an electrical signal as a function of the distance between the sensing means and said FET.
Claim 27
Dependent Claim 17 words
A monolithic temperature switch as recited in claim 24, wherein said sensing means includes a bimetallic element.
Claim 28
Dependent Claim 23 words
A monolithic temperature switch as recited in claim 11, wherein said switch is configured to provide squeeze film damping of said sensing element.
Claim 29
Dependent Claim 75 words
A monolithic temperature switch comprising: means for sensing temperature adapted to be displaced as a function of temperature between a first position and a second position; means operatively coupled to said sensing means for providing an electrical signal as a function of temperature; means for adding hysteresis to a displacement of said sensing means; and means for controlling the hysteresis; wherein said sensing means and said providing means are integrally formed on a monolithic chip.
Claim 30
Dependent Claim 75 words
A monolithic temperature switch comprising: means for sensing temperature adapted to be displaced as a function of temperature between a first position and a second position; means operatively coupled to said sensing means for providing an electrical signal as a function of temperature; means for adding hysteresis to a displacement of said sensing means; and means for controlling the hysteresis; wherein said sensing means and said providing means are integrally formed on a monolithic chip.
Claim 31
Dependent Claim 30 words
A monolithic temperature switch as recited in claim 27, wherein said controlling means includes a stop for adjusting one or the other of said first position or said second position.
Claim 32
Dependent Claim 17 words
A monolithic temperature switch as recited in claim 27, wherein said sensing means includes a bimetallic element.
Claim 33
Dependent Claim 74 words
A monolithic temperature switch comprising: means for sensing temperature which includes a bimetallic strip adapted to be displaced as a function of temperature between a first position and a second position; means operatively coupled to said sensing means for providing an electrical signal as a function of temperature; and means for applying an electrostatic force to said bimetallic strip; wherein said sensing means and said providing means are integrally formed on a monolithic chip.
Claim 34
Dependent Claim 74 words
A monolithic temperature switch comprising: means for sensing temperature which includes a bimetallic strip adapted to be displaced as a function of temperature between a first position and a second position; means operatively coupled to said sensing means for providing an electrical signal as a function of temperature; and means for applying an electrostatic force to said bimetallic strip; wherein said sensing means and said providing means are integrally formed on a monolithic chip.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-10-30 1999-05-01 1999-10-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-10-30 2003-05-01 2003-10-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-10-30 2007-05-01 2007-10-31 $7700.00 Window Closed / Lapsed

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