Protective mechanism in electrically operated devices
First Claim
1. A hazard prevention device for an electrical externally powered apparatus comprising:
- a housing, said housing having at least one opening and said housing comprising an electrical operating unit and a pair of spaced-apart electrically exposed electrically conductive probe networks, said pair being responsive to the entry of a conductive fluid electrically reducing the impedance between said probe networks of said pair;
electrical source lines comprising at least one nonground electrical source line;
a thermally actuated normally closed disconnect switch comprising at least one pair of normally closed contacts and an electrically conductive member, each said pair of normally closed contacts having a first contact and a second contact, said first contact being electrically connected to an electrical source line connection, said second contact connected to an electrical connection of said apparatus, each said pair of contacts being normally electrically closed in cooperation with said electrically conductive member, said member having two ends, one of said ends electrically connected to a nonground electrical source line of said electrical source lines, with at least each and every said first contact of each said pair of contacts which is associated with a respective nonground electrical source line being connected to its respective associated nonground electrical source line, with said thermally actuated normally closed disconnect switch operating so that upon electrical activity between said ends of said member through said member, termination of electrical conductivity between each and every said pair of normally closed contacts will occur;
a trigger circuit comprising a semiconductor switch, said semiconductor switch having a first terminal, a second terminal, and a gate input, said gate input being excited only upon low impedance between said probe networks of said pair of probe networks, said semiconductor switch being electrically conductive between said first terminal and said second terminal only upon said gate input excitation;
wherein entry of conductive fluid into said housing reduces said impedance between said probe networks of said pair causing said gate input excitation, which in turn causes said semiconductor switch to conduct between said first and second terminals, thereby providing electrical activity through said member causing said member to lose its ability to keep the normally-closed mechanical bias and associated electrical conductivity between said first contact and said second contact of each and every said pair of contacts, which in turn causes termination of electrical activity between said each said pair of normally closed contacts of said thermally actuated normally-closed disconnect switch, thus preventing injury to living species.
1 Assignment
0 Petitions
Accused Products
Abstract
To protect the operator of an electrically powered apparatus in a damp room or in the presence of water or other electrically conductive fluid against an electric shock, there is provided a protective device comprised of a probe in the form of a double conductor which the user cannot contact when handling or operating the apparatus. In the presence of a conductive fluid the impedance of the probe changes. The probe is connected to the input of a trigger switch circuit which includes a semiconductor switch. The trigger circuit triggers the semiconductor switch when the impedance of the probe changes. The current which flows as a result of the closing of the semiconductor switch releases an automatically opening switch, the contacts of which lie in the incoming power supply wires of the apparatus, which contacts are normally held closed by means of a material which is fusible upon direct or indirect heating by means of said current.
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Citations
19 Claims
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1. A hazard prevention device for an electrical externally powered apparatus comprising:
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a housing, said housing having at least one opening and said housing comprising an electrical operating unit and a pair of spaced-apart electrically exposed electrically conductive probe networks, said pair being responsive to the entry of a conductive fluid electrically reducing the impedance between said probe networks of said pair; electrical source lines comprising at least one nonground electrical source line; a thermally actuated normally closed disconnect switch comprising at least one pair of normally closed contacts and an electrically conductive member, each said pair of normally closed contacts having a first contact and a second contact, said first contact being electrically connected to an electrical source line connection, said second contact connected to an electrical connection of said apparatus, each said pair of contacts being normally electrically closed in cooperation with said electrically conductive member, said member having two ends, one of said ends electrically connected to a nonground electrical source line of said electrical source lines, with at least each and every said first contact of each said pair of contacts which is associated with a respective nonground electrical source line being connected to its respective associated nonground electrical source line, with said thermally actuated normally closed disconnect switch operating so that upon electrical activity between said ends of said member through said member, termination of electrical conductivity between each and every said pair of normally closed contacts will occur; a trigger circuit comprising a semiconductor switch, said semiconductor switch having a first terminal, a second terminal, and a gate input, said gate input being excited only upon low impedance between said probe networks of said pair of probe networks, said semiconductor switch being electrically conductive between said first terminal and said second terminal only upon said gate input excitation; wherein entry of conductive fluid into said housing reduces said impedance between said probe networks of said pair causing said gate input excitation, which in turn causes said semiconductor switch to conduct between said first and second terminals, thereby providing electrical activity through said member causing said member to lose its ability to keep the normally-closed mechanical bias and associated electrical conductivity between said first contact and said second contact of each and every said pair of contacts, which in turn causes termination of electrical activity between said each said pair of normally closed contacts of said thermally actuated normally-closed disconnect switch, thus preventing injury to living species. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A hazard prevention device for an electrical externally powered apparatus comprising:
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a pair of spaced-apart electrically exposed electrically conductive probes, said pair being responsive to the entry of a conductive fluid electrically reducing the impedance between said probes; electrical source lines, comprising at least one nonground electrical source line; a normally closed disconnect switch comprising at least one pair of normally closed contacts and an electrically conductive member, each said pair of normally closed contacts having a first contact and a second contact, said first contact being electrically connected to an electrical source line connection, said second contact connected to an electrical connection of said apparatus, each of said pair of contacts being normally electrically closed in cooperation with said electrically conductive member, said member having two ends, one of said ends electrically connected to a nonground line of said electrical source lines, with at least each and every said first contact of each said pair of contacts which is associated with a respective nonground electrical source line being connected to its respective associated nonground electrical source line, with said normally closed disconnect switch operating so that upon electrical activity between said ends of said member through said member, termination of electrical conductivity between each and every pair of said normally closed contacts will occur; a trigger circuit comprising a semiconductor switch, said semiconductor switch having a first terminal, a second terminal, and a gate input, said gate input being excited only upon low impedance between said probes of said pair of probes, said semiconductor switch being electrically conductive between said first terminal and said second terminal only upon said gate input excitation; wherein entry of conductive fluid between said pair of probes reduces said impedance between said probes causing said gate input excitation, which in turn causes said semiconductor switch to conduct between said first and second terminals, thereby providing electrical activity through said member causing said member to lose its ability to keep the normally-closed mechanical bias and associated electrical conductivity between said first contact and said second contact of each and every pair of contacts, which in turn causes termination of electrical activity between said pairs of normally closed contacts of said normally-closed disconnect switch, thus preventing injury to living species.
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12. A hazard prevention device for an electrical externally powered apparatus comprising:
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a housing, said housing having at least one opening and said housing comprising an electrical operating unit and a pair of spaced-apart electrically exposed conductive probe networks, said pair being responsive to the entry of a conductive fluid electrically reducing the impedance between said probe networks of said pair; electrical source lines comprising at least one nonground electrical source line; a thermally actuated normally closed disconnect switch comprising at least one pair of normally closed contacts and a fusible electrically conductive member, each said pair of contacts having a first contact and a second contact, said first contact being electrically connected to an electrical source line connection, said second contact connected to an electrical connection of said apparatus, each said pair of contacts being normally electrically closed in cooperation with said fusible electrically conductive member, said member having two ends, one of said ends electrically connected to a nonground electrical source line of said electrical source lines, with at least each and every said first contact of each said pair of contacts which is associated with a respective nonground electrical source line being connected to its respective associated nonground electrical source line, with said thermally actuated normally closed disconnect switch operating so that upon electrical activity between said ends of said member through said member, termination of electrical conductivity between each and every said pair of normally closed contacts will occur; a trigger circuit comprising a semiconductor switch, said semiconductor switch having a first terminal, a second terminal, and a gate input, said first terminal connected to one of said ends of said fusible electrically conductive member of said normally closed disconnect switch, said second terminal electrically connected to one of said electrical source lines other than the electrical source line connected to said end of said fusible member which is connected to said first terminal, said gate input being excited only upon a low impedance between said probe networks of said pair of probe networks, said semiconductor switch being electrically conductive between said first terminal and said second terminal only upon said gate input excitation; wherein entry of conductive fluid into said housing reduces said impedance between said probe networks of said pair causing said gate input excitation, which in turn causes said semiconductor switch to conduct between said first and second terminals, thereby providing electrical activity through said fusible member to cause said member to lose its ability to keep the normally closed mechanical bias and associated electrical conductivity between said first contact and said second contact of each said pair of contacts, which in turn causes termination of electrical activity between each said pair of normally closed contacts of said thermally actuated normally-closed disconnect switch, thus preventing injury to living species. - View Dependent Claims (13, 14, 15, 16)
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17. A hazard prevention device for an electrical externally powered apparatus comprising:
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a housing, said housing having at least one opening and said housing comprising an electrical operating unit and a pair of spaced-apart electrically exposed electrically conductive probe networks, said pair being responsive to the entry of a conductive fluid electrically reducing the impedance between said probe networks of said pair; electrical source lines comprising at least one nonground electrical source line; a thermally actuated normally closed disconnect switch comprising at least one pair fo normally closed contacts and a fusible electrically conductive member, each said pair havng a first contact and a second contact, said first contact being electrically connected to an electrical source line connection, said second contact connected to an electrical connection of said apparatus, each said pair of contacts being held normally electrically-closed by means of mechanical bias provided by said fusible electrically conductive member, said member having two ends, a first end electrically connected to a nonground line of said electrical source lines, with at least each and every said first contact of each said pair of contacts which is associated with a respective nonground electrical source line being connected to its respective associated nonground electrical source line, said fusible member losing its mechanical bias ability to keep said contacts normally closed for each pair upon electrical activity between said ends of said member, causing termination of electrical conductivity between each and every said pair of said normally closed contacts; a trigger circuit comprising a semiconductor switch, said semiconductor switch having a first terminal, a second terminal, and a gate input, said first terminal connected to one of said ends of said fusible electrically conductive member of said normally closed disconnect switch, said second terminal electrically connected to one of said electrical source lines other than the electrical source line connected to said first terminal'"'"'s associated end of said fusible member, and said gate input being excited only upon low impedance between said probe networks of said pair of probe networks, said semiconductor switch being electrically conductive between said first terminal and said second terminal only upon said gate input excitation; wherein entry of conductive fluid into said housing reduces said impedance between said probe networks of said pair causing said gate input excitation, which in turn causes said semiconductor switch to conduct between said first and second terminals, thereby providing electrical activity through said fusible member to cause said member to lose its ability to keep the normally closed mechanical bias and associated electrical conductivity between said first contact and said second contact of each pair of contacts, which in turn causes termination of electrical activity between each said pair of normally closed contacts of said thermally actuated normally-closed disconnect switch, thus preventing injury to living species. - View Dependent Claims (18, 19)
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Specification