Patent US2155220A successfully refreshed from Google Patents.
Patent US3820050A successfully refreshed from Google Patents.
US3820050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal switch
Assignee: Robertshaw Controls Co
•
Filing: 1973-07-13
•
Granted: 1974-06-25
•
Expires: 1993-07-13
Abstract
Abstract A thermal switch has a pair of conductors with a longitudinally movable contact element engaging a side of at least one of the conductors and forming an electrical connection between the conductors. The contact element is biased against a thermally yieldable member such that when a predetermined temperature is reached the member yields and the element is moved longitudinally off an edge of the one conductor to open the electrical connection between the conductors.
Inventors
- 👤 R Mitts
- 👤 H Tyler
- 👤 D Wolfe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:30
CPC Classifications
H; H01; H01H; H01H1/00; H01H1/12; H01H1/36; H01H1/38; H01H37/00; H01H37/74; H01H37/76; H01H37/764; H01H37/766
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
192 words
A thermal switch comprising a pair of conductors, one of the pair of conductors having a surface portion near an edge thereof, insulative means for supporting the one conductor with the one conductor surface portion extending in a direction which has a substantial directional component parallel to an axis, a rigid member which becomes yieldable at a predetermined temperature, a movable electrically conductive contact, means connected to the contact for engaging the rigid member in a direction which prevents movement of the contact parallel to the axis from the one conductor surface portion past the edge, means for electrically connecting the contact to the other of the pair of conductors, biasing means for engaging the contact with the one conductor surface portion in a direction transverse to the axis to form an electrical connection between the one conductor and the contact, and biasing means for urging the contact toward the edge of the one conductor in a direction parallel to the axis with a force which exceeds the sum of the frictional force between the contact and the conductor and the force to which the rigid member yields at the predetermined temperature.
Claim 2
Dependent Claim
192 words
A thermal switch comprising a pair of conductors, one of the pair of conductors having a surface portion near an edge thereof, insulative means for supporting the one conductor with the one conductor surface portion extending in a direction which has a substantial directional component parallel to an axis, a rigid member which becomes yieldable at a predetermined temperature, a movable electrically conductive contact, means connected to the contact for engaging the rigid member in a direction which prevents movement of the contact parallel to the axis from the one conductor surface portion past the edge, means for electrically connecting the contact to the other of the pair of conductors, biasing means for engaging the contact with the one conductor surface portion in a direction transverse to the axis to form an electrical connection between the one conductor and the contact, and biasing means for urging the contact toward the edge of the one conductor in a direction parallel to the axis with a force which exceeds the sum of the frictional force between the contact and the conductor and the force to which the rigid member yields at the predetermined temperature.
Claim 3
Dependent Claim
20 words
A thermal switch as claimed in claim 1 wherein the one conductor surface portion is substantially parallel to the axis.
Claim 4
Dependent Claim
83 words
A thermal switch as claimed in claim 1 wherein the means connected to the contact for engaging the rigid member includes a head engaging the rigid member, the biasing means for engaging the contact with the one conductor surface portion includes a cantilever spring arm extending from the head in a direction having a substantial directional component parallel to the axis, and the contact includes a conductive tip on the spring arm biased by the spring arm against the one conductor surface portion.
Claim 5
Dependent Claim
39 words
A thermal switch as claimed in claim 1 wherein the one conductor is an insulated conductive wire, and the one conductor surface portion is a section at the end of the wire from which the insulation has been stripped.
Claim 6
Dependent Claim
56 words
A thermal switch as claimed in claim 4, wherein the insulative means includes a first portion having a cavity with a groove formed in the wall of the cavity for receiving the stripped section of the wire, and the biasing means for engaging the contact with the stripped section urges the stripped section into the groove.
Claim 7
Dependent Claim
75 words
A thermal switch as claimed in claim 5 wherein the insulative means includes a second portion having a hole in alignment with the groove in the first portion of the insulating means, the wire extends through the hole and is supported by the second portion of the insulative means, and the length of the wire extending from the hole into the cavity has sufficient rigidity to prevent any substantial bending from the force of gravity.
Claim 8
Dependent Claim
112 words
A thermal switch as claimed in claim 6 wherein there is included a case for supporting the rigid member in one end of the case and for supporting the insulating means near another end of the case, the means connected to the contact for engaging the rigid member includes a head engaging the rigid member, the biasing means for engaging the contact with the stripped section includes a first cantilever spring arm extending from the head in a direction having a substantial directional component parallel to the axis, and the contact includes a conductive tip on the first spring arm biased by the spring arm against the stripped section of the wire.
Claim 9
Dependent Claim
75 words
A thermal switch as claimed in claim 7 wherein the rigid member includes a block of solid material which becomes fluid at the predetermined temperature, the solid block having a flat surface perpendicular to the axis; the biasing means for urging the contact toward the one conductor edge includes a helical compression spring between the insulative means and the head; and the head has a flat surface engaging the flat surface of the solid block.
Claim 10
Dependent Claim
74 words
A thermal switch is claimed in claim 7 wherein the biasing means for engaging the contact with the stripped section includes a second cantilever spring arm extending from the head in a direction having a substantial directional component parallel to the axis, and means engaged by the second spring arm for maintaining the first spring arm in an elastic stressed condition to force the conductive tip transversely against the stripped section of the wire.
Claim 11
Dependent Claim
122 words
A thermal switch comprising a pair of conductors, one conductor having a surface portion; insulative means having a groove for receiving and retaining the one conductor with the one conductor surface portion exposed; a rigid member which becomes yieldable at a predetermined temperature; a movable element including means for engaging the rigid member and an elastic cantilever arm with a conductive tip biased by the elastic arm into engaGement with the one conductor surface portion, means for electrically connecting the conductive tip to the other conductor, and biasing means for urging the movable element against the rigid member such that when rigid member becomes yieldable the movable element and conductive tip are moved out of engagement with the one conductor surface portion.
Claim 12
Dependent Claim
122 words
A thermal switch comprising a pair of conductors, one conductor having a surface portion; insulative means having a groove for receiving and retaining the one conductor with the one conductor surface portion exposed; a rigid member which becomes yieldable at a predetermined temperature; a movable element including means for engaging the rigid member and an elastic cantilever arm with a conductive tip biased by the elastic arm into engaGement with the one conductor surface portion, means for electrically connecting the conductive tip to the other conductor, and biasing means for urging the movable element against the rigid member such that when rigid member becomes yieldable the movable element and conductive tip are moved out of engagement with the one conductor surface portion.
Claim 13
Dependent Claim
56 words
A thermal switch as claimed in claim 10 where the conductors are insulated wires, the one conductor surface portion is a section at the end of one wire having the insulation stripped therefrom, and the insulative means includes a hole aligned with the groove for receiving the one wire longitudinally and retaining the one wire laterally.
Claim 14
Dependent Claim
177 words
A thermal switch comprising a pair of conductors each having a longitudinal surface portion near the edge thereof, insulative means for supporting the conductors in spaced relationship with the longitudinal surface portions of the conductors extending in directions which have substantial directional components parallel to an axis, a rigid member which becomes yieldable at a predetermined temperature, a movable means for conducting electrical current, means connected to the movable means for engaging the rigid member in a direction which prevents movement of the movable means parallel to the axis from the longitudinal surface portions past the edges, means for biasing the movable means transverse to the axis into engagement against the longitudinal surface portions of both of the conductors to form an electrical connection between the conductors, and means for biasing the movable means toward the edges of the conductors in a direction parallel to the axis with a force which exceeds the sum of the frictional force between the contact and the conductor and the force to which the rigid member yields at the predetermined temperatures.
Claim 15
Dependent Claim
177 words
A thermal switch comprising a pair of conductors each having a longitudinal surface portion near the edge thereof, insulative means for supporting the conductors in spaced relationship with the longitudinal surface portions of the conductors extending in directions which have substantial directional components parallel to an axis, a rigid member which becomes yieldable at a predetermined temperature, a movable means for conducting electrical current, means connected to the movable means for engaging the rigid member in a direction which prevents movement of the movable means parallel to the axis from the longitudinal surface portions past the edges, means for biasing the movable means transverse to the axis into engagement against the longitudinal surface portions of both of the conductors to form an electrical connection between the conductors, and means for biasing the movable means toward the edges of the conductors in a direction parallel to the axis with a force which exceeds the sum of the frictional force between the contact and the conductor and the force to which the rigid member yields at the predetermined temperatures.
Claim 16
Dependent Claim
84 words
A thermal switch as claimed in claim 12 wherein the means connected to the movable means for engaging the rigid member includes a head engaging the rigid member, the means for biasing the movable means transverse to the axis includes a pair of cantilever spring arms extending from the head in directions which have substantial directional components parallel to the axis, and the movable means includes a pair of conductive tips on the respective ends of the spring arms engaging the conductor surface portions.
Claim 17
Dependent Claim
19 words
A thermal switch as claimed in claim 13 wherein each of the conductive tips engages both conductor surface portions.
Claim 18
Dependent Claim
26 words
A thermal switch as claimed in claim 13 wherein the conductive tips are between the conductor surface portions and engage respective surface portions and each other.
Claim 19
Dependent Claim
82 words
A thermal switch as claimed in claim 12 wherein the pair of conductors are insulated wires with the insulation stripped from sections at ends of the wires to form the longitudinal surface portions, the insulative means includes a first portion having a cavity with a pair of grooves each formed in wall portions of the cavity for receiving the respective stripped sections, the means for biasing the movable means transverse to the axis also bias the stripped sections into the respective grooves.
Claim 20
Dependent Claim
82 words
A thermal switch as claimed in claim 16 wherein the means connected to the movable means includes a head engaging the rigid member, the movable means for biasing the movable means transverse to the axis includes a pair of cantilever spring arms extending from the head in directions which have substantial directional components parallel to the axis, and the movable means includes a pair of conductive tips on the respective ends of the spring arms engaging the stripped sections of the wires.
Claim 21
Dependent Claim
42 words
A thermal switch as claimed in claim 17 wherein the pair of grooves are formed in opposite wall portions of the cavity, and the conductive tips are wedge shaped and are wedged by the springs between the stripped sections of the wires.
Claim 22
Dependent Claim
49 words
A thermal switCh as claimed in claim 17 wherein the pair of grooves are formed in opposite wall portions of the cavity, and the conductive tips are disposed between the stripped sections and are biased by the spring arms into engagement with the respective stripped sections and each other.
Claim 23
Dependent Claim
40 words
A thermal switch as claimed in claim 19 wherein the conductive tips engage each other at a fulcrum point and the spring arms bias the conductive tips in a pivotal relationship about the fulcrum point against the respective stripped sections.
Claim 24
Dependent Claim
129 words
A thermal switch comprising a pair of conductors, a tubular case, a block of rigid material which becomes fluid at a predetermined temperature secured at one end of the casing, a movable head with a cross section perpendicular to the axis of the case slightly smaller than the cross section of the internal passageway of the case, means for biasing the head against the block, means in the other end of the case operated by the movable head for electrically connecting the pair of conductors until the predetermined temperature is reached and the head is allowed to be moved by the biasing means to electrically disconnect the pair of conductors, and said tubular case being made of a brittle material which breaks upon impact rather than bending upon impact.
Claim 25
Dependent Claim
129 words
A thermal switch comprising a pair of conductors, a tubular case, a block of rigid material which becomes fluid at a predetermined temperature secured at one end of the casing, a movable head with a cross section perpendicular to the axis of the case slightly smaller than the cross section of the internal passageway of the case, means for biasing the head against the block, means in the other end of the case operated by the movable head for electrically connecting the pair of conductors until the predetermined temperature is reached and the head is allowed to be moved by the biasing means to electrically disconnect the pair of conductors, and said tubular case being made of a brittle material which breaks upon impact rather than bending upon impact.
Claim 26
Dependent Claim
104 words
A thermal switch as claimed in claim 21 wherein the pair of conductors are insulated wires with the insulation stripped from sections at the ends of the wires, there is included insulative means for supporting the stripped sections in spaced relationship longitudinally within the case, the electrically connecting means includes a pair of cantilever spring arms extending longitudinally from the head and a conductive tip on at least one of the spring arms biased by the spring arms into engagement with the stripped sections to electrically connect the wires, and the biasing means includes a helical compression spring between the head and insulative means.
Claim 27
Dependent Claim
184 words
A thermal switch comprising a tubular case closed at one end; a block of rigid material which becomes fluid at a predetermined temperature disposed in the one end of the case; a pair of insulated wires having the insulation stripped from sections at the ends of the wires; insulative means mounted toward the other end in the case having a central cavity with a pair of parallel grooves formed longitudinally relative to the case in opposite wall portions of the cavity for receiving the stripped sections; a movable conductive element having a head portion engaging the block, a pair of cantilever spring arms extending longitudinally from the head portion into the central cavity of the insulative means, and conductive tip portions on the respective spring arm portions biased by the spring arm portions transversely relative to the case against the stripped sections of the wires to form an electrical connection between the conductors; and a compression spring between the insulator and the head portion for moving the movable element and the conductive tip portions from the central cavity when the solid material becomes fluid.
Claim 28
Dependent Claim
184 words
A thermal switch comprising a tubular case closed at one end; a block of rigid material which becomes fluid at a predetermined temperature disposed in the one end of the case; a pair of insulated wires having the insulation stripped from sections at the ends of the wires; insulative means mounted toward the other end in the case having a central cavity with a pair of parallel grooves formed longitudinally relative to the case in opposite wall portions of the cavity for receiving the stripped sections; a movable conductive element having a head portion engaging the block, a pair of cantilever spring arms extending longitudinally from the head portion into the central cavity of the insulative means, and conductive tip portions on the respective spring arm portions biased by the spring arm portions transversely relative to the case against the stripped sections of the wires to form an electrical connection between the conductors; and a compression spring between the insulator and the head portion for moving the movable element and the conductive tip portions from the central cavity when the solid material becomes fluid.
Claim 29
Dependent Claim
70 words
A thermal switch as claimed in claim 23 wherein the insulative means has a portion with parallel holes extending longitudinally for receiving and supporting the wires in parallel spaced relationship with lengths of the wires extending from the holes into the central cavity, and the rigidities of the lengths of the wires are selected to prevent the stripped sections of the wires from being bent by gravitational forces into engagement.
Claim 30
Dependent Claim
46 words
A thermal switch as claimed in claim 23 wherein the tubular case, the insulative means and the head portion of the movable element have mating non-circular cross sections perpendicular to the axis of the tubular case to align the conducting tip portions relative to the conductors.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |