GB2052228A
Expired / Lapsed
GB
⏱️ 0.0 years remaining
Flexible heating elements and dies and processes for the production thereof
Assignee: Sunbeam Corp
•
Filing: 1980-05-09
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Granted: —
•
Expires: 2000-05-09
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
GB
Data Source
google_patents
Last Synchronized
2026-11-05 09:31
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/40; H05B3/54; H05B3/56; B; B29; B29C; B29C48/00; B29C48/15; B29C48/156; H01; H01C; H01C7/00; H01C7/02; H01C7/027; H05B3/10; H05B3/12; H05B3/14; H05B3/146; B29C48/03; B29C48/12; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49083
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
160 words
CLAIMS 1. A flexible beating element for use in an electric blanket which comprises at least two flexible electrical conductors spaced apart by a PTC material, an amorphous highly conductive rubber compatible with the said PTC material and adhered to each conductor being interposed between the PTC material and each conductor whereby in use current passes from one conductor to another through the PTC material via the said highly conductive rubber, the conductors being spaced sufficiently close to one another to ensure that when energised the PTC material heats substantially uniformly without exhibiting a significant temperature gradient between the conductors and that any abnormal temperature increase increases the temperature of all the PTC material between the conductors in the region of the abnormal temperature increase, the arrangement being such that in use the contact 4 7 GB 2 052 228 A 7 resistance between the conductors and the PTC material is reduced by the amorphous highly conductive rubber interposed therebetween.
Claim 2
Dependent Claim
24 words
A heating element as claimed in claim 1 wherein the PTC material comprises a polymer having a glass.transition temperature of from -1251 to -750C.
Claim 3
Dependent Claim
19 words
A heating element as claimed in claim 1 or claim 2 wherein the PTC material comprises a 5 polyolefin.
Claim 4
Dependent Claim
29 words
A heating element as claimed in any one of claims 1 to 3 wherein the PTC material comprises polyethylene, polypropylene, ethylene-propylene copolymers or terpolymers; thereof with non conjugated dienes.
Claim 5
Dependent Claim
21 words
A heating element as claimed in any one of the preceding claims wherein the PTC material 10 comprises high density polyethylene.
Claim 6
Dependent Claim
28 words
A heating element as claimed in any one of the preceding claims wherein the PTC material comprises 2,5-ditertiary amyl hydroquinone as antioxiclant in an amount of 3-5 phr.
Claim 7
Dependent Claim
22 words
A heating element as claimed in any one of the preceding claims wherein the amorphous highly conductive rubber comprises an epichlorohydrin rubber.
Claim 8
Dependent Claim
17 words
A heating element as claimed in claim 7 wherein the epichlorohydrin rubber contains about 35% ethylene oxide.
Claim 9
Dependent Claim
24 words
A heating element as claimed in claim 8 wherein the amorphous highly conductive rubber contains about 65% epichlorohydrin rubber and about 35% ethylene oxide.
Claim 10
Dependent Claim
27 words
A heating element as claimed in any one of claims 1 to 6 wherein the amorphous highly 20 conductive rubber comprises butyl rubber or chlorinated butyl rubber.
Claim 11
Dependent Claim
26 words
A heating element as claimed in any one of the preceding claims wherein the conductor comprises copper, silver, tin, nickel or aluminium or an alloy thereof.
Claim 12
Dependent Claim
19 words
A heating element as claimed in claim 11 wherein the conductor comprises copper containing about 1% by weight cadmium.
Claim 13
Dependent Claim
22 words
A heating element as claimed in claim 11 or claim 12 wherein the conductor comprises copper plated with silver, tin or nickel.
Claim 14
Dependent Claim
18 words
A heating element as claimed in any one of the preceding claims wherein the conductor is nodulated. 30
Claim 15
Dependent Claim
20 words
A heating element as claimed in any one of the preceding claims wherein the surface of the conductor is activated.
Claim 16
Dependent Claim
28 words
A heating element as claimed in any one of the preceding claims wherein a layer of graphite is interposed between the amorphous highly conductive rubber and the conductor.
Claim 17
Dependent Claim
39 words
A heating element as claimed in any one of the preceding claims of substantially dumb-bell or dog-bone cross section wherein a flexible electrical conductor spiralled around a core is positioned in 35 each head of the dumb-bell or dog-bone.
Claim 18
Dependent Claim
14 words
A heating element as claimed in claim 17 wherein the core comprises glass fibre.
Claim 19
Dependent Claim
58 words
A heating element as claimed in claim 17 or claim 18 wherein the flexible electrical conductor is spiralled around the core in one direction in one head of the dumb- bell or dog-bone and the flexible electrical conductor is spiralled around the core in the opposite direction in the other head of the dumb- 40 bell or dog-bone.
Claim 20
Dependent Claim
24 words
A heating element as claimed in any one of claims 17-19 wherein the flexible electrical conductor is spiralled around the core by back twisting.
Claim 21
Dependent Claim
30 words
2 1. A heating element as claimed in any one of the preceding claims provided with an outer electrically insulating layer of polyurethane, cross-linked polyethylene or thermal plastic rubber. 45
Claim 22
Dependent Claim
18 words
A flexible heating element as claimed in claim 1 substantially as herein described with reference to Fig. 1.
Claim 23
Dependent Claim
14 words
A flexible heating element substantially as herein described in any one of the Examples.
Claim 24
Dependent Claim
46 words
A process for producing a flexible heating element as claimed in any one of the preceding claims which comprises extruding the amorphous highly conductive rubber to cover each flexible -electrical conductor and subsequently or simultaneously extruding the PTC material to cover the amorphous highly conductive rubber.
Claim 25
Dependent Claim
31 words
A process as claimed in claim 24 wherein each flexible electrical conductor is coated with a colloidal graphite solution and cured prior to extrusion of the amorphous highly conductive rubber thereover.
Claim 26
Dependent Claim
20 words
A process as claimed in claim 25 wherein each flexible electrical conductor is dip coated with the colloidal graphite solution.
Claim 27
Dependent Claim
54 words
A process as claimed in any one of claims 24 to 26 wherein each flexible electrical conductor, in the form of a spiralled wire, is covered with the amorphous highly conductive rubber and the PTC material extruded over the amorphous highly conductive rubber whereby curing of the amorphous 60 rubber is effected during extrusion.
Claim 28
Dependent Claim
25 words
A process as claimed in any one of claims 24-27 wherein annealing is effected whereby to reduce the resistance of the positive temperature coefficient extrudate.
Claim 29
Dependent Claim
45 words
A process as claimed in claim 28 wherein the positive temperature coefficient material comprises high density polyethylene, butyl rubber, carbon black and at least 3 phr of an antioxidant and 65 GB 2 052 228 A 8 in which annealing is effected at about 1300C.
Claim 30
Dependent Claim
11 words
A process as claimed in claim 24 substantially as herein described.
Claim 31
Dependent Claim
22 words
3 1. A process for the production of a flexible heating element substantially as herein described in any one of the Examples.
Claim 32
Dependent Claim
20 words
A flexible heating element as claimed in claim 1 when prepared by a process as claimed in 5 claim 24.
Claim 33
Dependent Claim
67 words
A die for producing a flexible heating element according to the invention by co-extrusion, the die comprising means for feeding two spaced-apart, flexible eiectrical conductors through the die, means for extruding an amorphous highly conductive rubber to cover each of the said conductors, and means for extruding a positive temperature coefficient material so as to cover said rubber and to fill the 10 space between the conductors.
Claim 34
Dependent Claim
40 words
A die as claimed in claim 33 provided with means for adjusting the relative orientation and/or position of guide means for the conductors, a die head for the amorphous rubber and/or a die head for the positive temperature coefficient material.
Claim 35
Dependent Claim
34 words
A die as claimed in claim 33 or claim 34 wherein at least part of the die head for the 1 amorphous rubber comprises a heat insulating material capable of withstanding the extrusion temperatures.
Claim 36
Dependent Claim
17 words
A die as claimed in claim 35 wherein the heat insulating material comprises nylon, polytetrafluoroethylene or asbestos.
Claim 37
Dependent Claim
36 words
A die as claimed in any one of claims 34 to 36 wherein air gaps are provided between the die 20 head for the positive temperature coefficient material and the die hed for the amorphous rubber.
Claim 38
Dependent Claim
42 words
A die as claimed in any one of claims 34 to 37 wherein the positive temperature coefficient material is supplied from an extruder to an annular chamber connected by an annular passage to the die head for the positive temperature coefficient material.
Claim 39
Dependent Claim
11 words
A die substantially as herein described with reference to Fig. 2.
Claim 40
Dependent Claim
63 words
A process for producing a flexible heating element as claimed in any one of claims 24to 31 wherein a die as claimed in any one of claims 33 to 39 is used. Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1981. Published by the Patent Office, Southampton Buildings, London, WC2A lAY, from which copies may be obtained. 1 11
References Cited (Backward Citations)
No citation records indexed.
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