Patent US2919138A successfully refreshed from Google Patents.
US3636493A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistor with heat dissipating means
Assignee: Individual
•
Filing: 1970-05-25
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Granted: 1972-01-18
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Expires: 1990-05-25
Abstract
Abstract A disc-shaped metal body or base of anodized aluminum has an upstanding central post, the body and post being centrally bored to receive a bolt for stacking or mounting of the resistor. A ceramic wafer or washer is seated on the body and around the post, and has a resistive film provided on the upper surface thereof. The configuration of the resistive film is such that the temperature generated in the central region of the resistor, relatively adjacent the post, is greater than is the temperature generated remote from the post, thus setting up a highly effective thermal gradient which maximizes the dissipation of heat from the resistor. Terminal lugs or leads connect to the resistive film and extend outwardly generally in the plane of the washer, there being a connection between each lug and the washer by means of a rivet the ends of which are embedded in thermosetting synthetic resin. All of the components are maintained protected from the environment by a mass of thermosetting synthetic resin which extends upwardly from the film and surrounds the post, the upper surface of the resin being flush with the top of the post and parallel to the bottom of the metal body, in order to permit stacking of the resistors. The body and/or central post incorporate undercut means to prevent axial and rotational movement of the resin relative to the body, despite high thermal and other stresses. In accordance with the method, the preassembled body and ceramic washer (bearing the resistive film) are mounted as inserts in a mold cavity the depth of which is approximately equal to the distance between the upper end of the post and the bottom surface of the metal body. Thus, despite the absence of a plug in the central bore in the post, no molding material enters such bore. Molding is effected by transfer molding, and the mold gate is disposed adjacent the parting line and also generally adjacent or above the ceramic washer. The terminal lugs or leads extend outwardly from the mold cavity through corresponding grooves or recesses located at the parting line.
Inventors
- 👤 Richard E Caddock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:29
CPC Classifications
H; H01; H01C; H01C1/00; H01C1/08; H01C1/084; H01C1/14; H01C10/00; H01C10/30; H01C10/32; H01C17/00; H01C17/02
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
173 words
A power resistor, which comprises: a disc of metal, said disc having a central opening therethrough sufficiently large to receive a mounting bolt, a layer of electrically insulating and thermally conductive material provided on the upper surface of said metal disc in effective heat-transfer relationship thereto, an electrically resistive film provided on the upper surface of said insulating layer, termination means for said resistive film, said termination means including first and second electrical conductors electrically connected to said film and extending outwardly therefrom, and a mass of synthetic resin molded over said resistive film and over said insulating layer to embed said film and said layer, said mass of resin also embedding the inner portions of said electrical conductors, said mass of resin having an opening therethrough registEred with said opening in said metal disc, said mass of resin being disposed on only the upper side of said metal disc whereby the lower surface of said metal disc may be mounted by said mounting bolt in effective heattransfer relationship to an underlying chassis.
Claim 2
Dependent Claim
173 words
A power resistor, which comprises: a disc of metal, said disc having a central opening therethrough sufficiently large to receive a mounting bolt, a layer of electrically insulating and thermally conductive material provided on the upper surface of said metal disc in effective heat-transfer relationship thereto, an electrically resistive film provided on the upper surface of said insulating layer, termination means for said resistive film, said termination means including first and second electrical conductors electrically connected to said film and extending outwardly therefrom, and a mass of synthetic resin molded over said resistive film and over said insulating layer to embed said film and said layer, said mass of resin also embedding the inner portions of said electrical conductors, said mass of resin having an opening therethrough registEred with said opening in said metal disc, said mass of resin being disposed on only the upper side of said metal disc whereby the lower surface of said metal disc may be mounted by said mounting bolt in effective heattransfer relationship to an underlying chassis.
Claim 3
Dependent Claim
23 words
The invention as claimed in claim 1, in which means are provided to mechanically lock said mass of resin to said metal disc.
Claim 4
Dependent Claim
27 words
The invention as claimed in claim 2, in which said lock means prevents movement of said resin mass both axially and rotationally relative to said metal disc.
Claim 5
Dependent Claim
29 words
The invention as claimed in claim 1, in which said embedded inner portions of said electrical conductors lie generally in the same plane as that of said resistive film.
Claim 6
Dependent Claim
35 words
The invention as claimed in claim 1, in which said mass of resin has an upper surface parallel to said lower surface of said metal disc, and in which both of said surfaces are planar.
Claim 7
Dependent Claim
57 words
The invention as claimed in claim 1, in which said resistive film extends around said central opening in said disc, and in which said film has such a configuration that the temperature of said metal disc at regions relatively adjacent said opening is substantially greater than that of said metal disc at regions remote from said opening.
Claim 8
Dependent Claim
61 words
The invention as claimed in claim 6, in which said film has a generally C-shaped configuration, in which said electrical conductors electrically connect to the respective ends of the C, in which the inner circular edge of the C is adjacent said opening, and in which the outer circular edge of the C is adjacent the periphery of said insulating layer.
Claim 9
Dependent Claim
46 words
The invention as claimed in claim 1, in which said mass of resin has a peripheral wall the diameter of which is generally the same as the outer diameter of said metal disc, said wall and said resin serving as the housing of the power resistor.
Claim 10
Dependent Claim
59 words
The invention as claimed in claim 1, in which said metal disc has integrally associated therewith a tubular metal post, the opening within said post registering with said central opening in said disc, and in which said mass of resin is molded around said post whereby said opening in said resin is coincident with said opening within said post.
Claim 11
Dependent Claim
30 words
The invention as claimed in claim 1, in which the upper and lower surfaces of said metal disc, and said resistive film, are all planar and parallel to each other.
Claim 12
Dependent Claim
23 words
The invention as claimed in claim 1, in which said electrical conductors are adjacent each other on the same side of the resistor.
Claim 13
Dependent Claim
208 words
A laminar power resistor, which comprises: a metal disc having a central opening therethrough and having planar upper and lower surfaces, a metal post connected fixedly to said disc and extending upwardly from the upper surface of said disc coaxially therewith, said post having an axial opening therethrough registered with and forming an extension of said central opening in said disc, said openings in said disc and said post being adapted to receive a mounting bolt, a heat-transmissive wafer of electrically insulating material, said wafer having planar upper and lower surfaces parallel to each other, said lower surface of said wafer being mounted adjacent, and in effective heat-transfer relationship relative to, said upper surface of said metal disc, said wafer having a central opening therein through which said post extends, a planar film of electrically resistive material adhered to said upper surface of said wafer, termination means for said resistive film and including first and second electrical conductors portions of which extend radially outwardly from said film in generally the same plane as that of said film, and a mass of thermosetting synthetic resin molded around said post and over said film and said wafer, and over the inner portions of said termination means, to embed the same.
Claim 14
Dependent Claim
208 words
A laminar power resistor, which comprises: a metal disc having a central opening therethrough and having planar upper and lower surfaces, a metal post connected fixedly to said disc and extending upwardly from the upper surface of said disc coaxially therewith, said post having an axial opening therethrough registered with and forming an extension of said central opening in said disc, said openings in said disc and said post being adapted to receive a mounting bolt, a heat-transmissive wafer of electrically insulating material, said wafer having planar upper and lower surfaces parallel to each other, said lower surface of said wafer being mounted adjacent, and in effective heat-transfer relationship relative to, said upper surface of said metal disc, said wafer having a central opening therein through which said post extends, a planar film of electrically resistive material adhered to said upper surface of said wafer, termination means for said resistive film and including first and second electrical conductors portions of which extend radially outwardly from said film in generally the same plane as that of said film, and a mass of thermosetting synthetic resin molded around said post and over said film and said wafer, and over the inner portions of said termination means, to embed the same.
Claim 15
Dependent Claim
111 words
The invention as claimed in claim 12, in which said resistive film extends around said post, in which substantial portions of said film are located adjacent the peripheral edge portion of said wafer, in which other substantial portions of said film are located adjacent the inner edge portion of said wafer near said central opening therein, and in which the configuration of said film is such that the temperature created at said other substantial portions of said film, due to passage of current therethrough from one of said electrical conductors to the other, is substantially higher than the temperature created at said first-mentioned substantial portions due to said passage of current.
Claim 16
Dependent Claim
28 words
The invention as claimed in claim 13, in which said resistive film is generally C-shaped, and in which said conductors connect, respectively, to the ends of the C.
Claim 17
Dependent Claim
40 words
The invention as claimed in claim 12, in which the upper surface of said mass of resin is parallel to said planar lower surface of said metal disc and is substantially flush with the upper end of said metal post.
Claim 18
Dependent Claim
30 words
The invention as claimed in claim 13, in which said mass of resin has a generally cylindrical wall which is substantially flush with the peripheral edge of said metal disc.
Claim 19
Dependent Claim
34 words
The invention as claimed in claim 12, in which said first and second electrical conductors protrude outwardly from said mass of resin on the same side of said mass and relatively adjacent each other.
Claim 20
Dependent Claim
26 words
The invention as claimed in claim 12, in which said metal disc and said metal post are integral with each other and are formed of aluminum.
Claim 21
Dependent Claim
17 words
The invention as claimed in claim 12, in which said wafer is a thin disc of ceramic.
Claim 22
Dependent Claim
32 words
The invention as claimed in claim 12, in which means are provided to lock said mass of resin to said metal disc, thereby preventing separation thereof despite strong mechanical and thermal stresses.
Claim 23
Dependent Claim
41 words
The invention as claimed in claim 20, in which said locking means includes interlocking regions to prevent both axial movement of said mass of resin relative to said disc and rotational movement of said mass of resin relative to said disc.
Claim 24
Dependent Claim
117 words
The invention as claimed in claim 21, in which the upper edge of said metal disc is indented inwardly from the extreme peripheral edge of said disc, in which said insulating wafer is disposed on the upper surface of the indented portion of said metal disc, in which part of said mass of resin is disposed in encompassing relationship around the wall formed by said indented edge of said metal disc, and in which a plurality of recesses are provided circumferentially around said wall and are filled with parts of said mass of resin in order to perform said function of locking said mass of resin against both axial and rotational movements relative to said metal disc.
Claim 25
Dependent Claim
49 words
The invention as claimed in claim 12, in which said metal post is tubular and has a substantially cylindrical exterior surface, and in which said central opening in said insulating wafer is circular and is only slightly larger than the diameter of said cylindrical exterior surface of said post.
Claim 26
Dependent Claim
40 words
The invention as claimed in claim 12, in which said termination means includes first and second metal films adhered to said upper surface of said wafer and in electrical contact, respectively, with different portions of said film of resistive material.
Claim 27
Dependent Claim
60 words
The invention as claimed in claim 24, in which said first and second electrical conductors are terminal lugs in the form of flat bands or strips of metal, the inner ends of said terminal lugs being disposed in flatwise engagement with said metal films, and in which means are provided to mechanically connect said inner lug ends to said wafer.
Claim 28
Dependent Claim
114 words
The invention as claimed in claim 25, in which said mechanical connector means each comprises a hollow rivet extended through a hole in an associated terminal lug and a corresponding hole in said wafer, in which a counterbore is provided in said lower surface of said wafer and adapted to receive the lower end of said rivet, in which the upper and lower ends of said rivets are flared oUtwardly, in which the lower end of said rivet is spaced substantially above said lower surface of said wafer, and in which part of said mass of resin extends through said rivet and fills said counterbore whereby to insulate said rivet from said metal disc.
Claim 29
Dependent Claim
55 words
The invention as claimed in claim 24, in which said first and second electrical conductors comprises insulated flexible wires electrically connected to said metal films and mechanically connected to said wafer, a length along each of said wires equal to at least five diameters of the insulation thereon being embedded in said mass of resin.
Claim 30
Dependent Claim
131 words
The invention as claimed in claim 12, in which said termination means includes first and second metal films adhered to said upper surface of said wafer and in electrical contact, respectively, with different portions of said film of resistive material, in which each of said electrical conductors is a flexible lead enclosed in a tubular sleeve of electrically insulating and heat resisting material, in which means are provided to mechanically connect exposed ends of said flexible leads to said wafer on one side of said post and in electrical contact with said films, and in which the unexposed portions of said flexible leads are disposed on said resistive film and in straddling relationship to said post and extend generally diametrically from said exposed ends to the opposite region of the resistor.
Claim 31
Dependent Claim
101 words
The invention as claimed in claim 28, in which said mechanical connector means for each of said leads is a hollow rivet extending through a lug which is connected to an exposed end of said lead, said rivet also extending through said wafer and into a counterbore provided in the lower surface of said wafer, the lower end of said rivet being spaced a substantial distance above the plane of the lower surface of said wafer, and in which part of said resin is disposed in said hollow rivet and in said counterbore to insulate said rivet from said metal disc.
Claim 32
Dependent Claim
64 words
The invention as claimed in claim 12, in which a second metal disc is mounted above said first-mentioned metal disc and in electrically insulated heat-transfer relationship to said resistive film, said second metal disc having an upper surface parallel to said lower surface of said first-mentioned metal disc, and in which said mass of resin is provided between said first-mentioned and second metal discs.
Claim 33
Dependent Claim
64 words
The invention as claimed in claim 30, in which a layer of heat-transmissive and electrically insulating material is provided between said resistive film and said second metal disc to form the insulation therebetween, said layer being closely adjacent said resistive film and closely adjacent said second metal disc to create a high rate of heat transfer between said film and said second metal disc.
Claim 34
Dependent Claim
57 words
The invention as claimed in claim 30, in which said upper surface of said second metal disc is flush with the upper end of said post, and in which the periphery of said mass of resin is a cylindrical wall which is flush with the peripheral edges of said first-mentioned metal disc and said second metal disc.
Claim 35
Dependent Claim
23 words
The invention as claimed in claim 12, in which said resistive film is formed of a complex metal oxide in a glass matrix.
Claim 36
Dependent Claim
53 words
The invention as claimed in claim 12, in which a plurality of said resistors are mounted on a mounting bolt in stacked relationship, and in which a relatively large area metal plate is provided between each two adjacent resistors in order to form a heat-transmissive fin to carry heat away from said resistors.
Claim 37
Dependent Claim
72 words
The invention as claimed in claim 12, in which each of said first and second electrical conductors is a terminal lug the inner end portion of which is embedded in said resin, and in which each of said lugs has a hole therethrough adjacent the peripheral portion of said wafer and filled with said resin, the region of said lug adjacent said hole being adapted to flex and absorb shock and bending.
Claim 38
Dependent Claim
31 words
The invention as claimed in claim 35, in which said lug is Riveted to said wafer at a point between said opening in said wafer and said hole in said lug.
Claim 39
Dependent Claim
25 words
The invention as claimed in claim 35, in which said lug is a flat band of metal parallel to said upper surface of said wafer.
Claim 40
Dependent Claim
29 words
The invention as claimed in claim 37, in which means are provided on the sides of said lug, adjacent said hole therethrough, to form shoulders embedded in said resin.
Claim 41
Dependent Claim
180 words
A current-carrying device characterized by a high rate of heat dissipation, high environmental performance, and high resistance to breakdown despite relatively large-magnitude applied voltages, which comprises: a metal base adapted to be mounted on a metal chassis in effective heat-transfer relationship thereto, electrical insulator means mounted above said metal base in effective heat-transfer relationship thereto, said insulator means having a hole therethrough and a counterbore in the underside thereof and registered with said hole, a current-carrying element provided on the upper surface of said insulator means in effective heat-transfer relationship thereto, termination means for the terminals of said current-carrying element, at least one of said termination means including a hollow rivet extended through said hole and said counterbore, the portion of said rivet in said counterbore being spaced substantially above the bottom wall of said insulator means, and a mass of synthetic resin provided around said insulator means and said current-carrying element to embed the same, a portion of said mass being disposed in said rivet and in said counterbore to thereby effectively insulate said rivet from said metal base.
Claim 42
Dependent Claim
180 words
A current-carrying device characterized by a high rate of heat dissipation, high environmental performance, and high resistance to breakdown despite relatively large-magnitude applied voltages, which comprises: a metal base adapted to be mounted on a metal chassis in effective heat-transfer relationship thereto, electrical insulator means mounted above said metal base in effective heat-transfer relationship thereto, said insulator means having a hole therethrough and a counterbore in the underside thereof and registered with said hole, a current-carrying element provided on the upper surface of said insulator means in effective heat-transfer relationship thereto, termination means for the terminals of said current-carrying element, at least one of said termination means including a hollow rivet extended through said hole and said counterbore, the portion of said rivet in said counterbore being spaced substantially above the bottom wall of said insulator means, and a mass of synthetic resin provided around said insulator means and said current-carrying element to embed the same, a portion of said mass being disposed in said rivet and in said counterbore to thereby effectively insulate said rivet from said metal base.
Claim 43
Dependent Claim
69 words
The invention as claimed in claim 39, in which said termination means comprises a terminal lug the inner end of which is embedded in said synthetic resin, said inner end of said terminal lug having a hole therethrough and through which said rivet extends to thereby effectively mechanically lock said terminal lug to said insulator means, the outer end of said terminal lug protruding from said mass of resin.
Claim 44
Dependent Claim
62 words
The invention as claimed in claim 40, in which a conductive film is provided on said insulator means beneath said inner end of said terminal lug, said conductive film being connected to one terminal of said current-carrying element, and in which said insulator means is a ceramic having a substantial ability to transfer heat from said current-carrying element to said metal base.
Claim 45
Dependent Claim
75 words
The invention as claimed in claim 40, in which said terminal lug has a hole therethrough at a region between said rivet and the protruding outer end of said terminal lug, said hole receiving a part of said mass of resin, the regions of said terminal lug adjacent said hole being relatively flexible in order to prevent transmission of bending and vibrational stresses from the protruding outer end of said terminal lug to said rivet.
Claim 46
Dependent Claim
52 words
The invention as claimed in claim 42, in which the portions of said terminal lug relatively adjacent said hole therethrough comprise radially outwardly extending shoulders adapted to bear against the adjacent regions of said mass of resin to thereby aid in preventing pulling of said terminal lug out of said resin mass.
Claim 47
Dependent Claim
55 words
The invention as claimed in claim 39, in which said termination means comprises insulated flexible leads at least one of which is connected to said rivet, said lead including a portion having a length equal to at least five diameters of the insulation on said lead, said portion being embedded in said mass of resin.
Claim 48
Dependent Claim
53 words
The invention as claimed in claim 44, in which said lead is formed of a flexible conductor enclosed in a tubular sleeve of heat-resisting insulating material, and in which an exposed end of said flexible conductor is mechanically and electrically connected to a lug having an opening therein through which said rivet extends.
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) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |