Patent US1050385A successfully refreshed from Google Patents.
Patent US3914565A successfully refreshed from Google Patents.
US3914565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical plug with ground prong activated switch
Assignee: Individual
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Filing: 1974-08-26
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Granted: 1975-10-21
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Expires: 1994-08-26
Abstract
Abstract A plug for a conventional 110 volt electrical appliance includes switches between the two current carrying prongs and the wires leading to the appliance. The switches are normally open. The ground prong is longitudinally movable in the plug and urged outwardly by a spring. When the plug is inserted into a socket, the ground prong contacts the back of the socket before the plug is completely inserted. Continued insertion of the plug causes the ground prong to be moved an additional distance into the plug. As this occurs, a cam attached to the ground prong closes the switches thereby establishing an electrical connection between the current carrying prongs and the appliance wires.
Inventors
- 👤 Karl O Niedermeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:48
CPC Classifications
H; H01; H01R; H01R13/00; H01R13/66; H01R13/70; H01R13/703; H01R13/7036; H01H; H01H13/00; H01H13/02; H01H13/12; H01R13/713
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
324 words
In an electrical plug including a body having an end, two current carrying prongs extending from said end, a ground prong extending from said end and having a longitudinal axis and wire connector means for connecting electrical wires to the respective prongs, said ground prong normally extending a given distance from said body, which plug is to be inserted into an electrical socket having first and second ways for receiving the current carrying prongs respectively, a third way for receiving the ground prong and means associated with the third way for restricting movement of the ground prong with respect to the third way, the improvement wherein said plug includes: switch means in said body and connected between one of said current carrying prongs and the respective wire connector means, said switch means being movable between switch-open and switch-closed positions; said body journaling said ground prong for longitudinal movement between a first position at which the ground prong extends more than said given distance from said body and a second position at which the ground prong extends approximately said given distance from said body; means engaging said body and said ground prong for resiliently urging said ground prong toward said first position and away from said second position; and switch operating means engaging said ground prong and said switch means for placing said switch means in switch-open position when said ground prong is in the first position and placing said switch means in switch-closed position when the ground prong is in the Second position; whereby when the plug is not in the socket the ground prong is in the first position and the switch means is in the switchopen position, and when the plug is inserted into the socket the means associated with the third way restricts the movement of the ground prong thereby moving the ground prong from the first to the second position and thus placing the switch means in the switch-closed position.
Claim 2
Dependent Claim
324 words
In an electrical plug including a body having an end, two current carrying prongs extending from said end, a ground prong extending from said end and having a longitudinal axis and wire connector means for connecting electrical wires to the respective prongs, said ground prong normally extending a given distance from said body, which plug is to be inserted into an electrical socket having first and second ways for receiving the current carrying prongs respectively, a third way for receiving the ground prong and means associated with the third way for restricting movement of the ground prong with respect to the third way, the improvement wherein said plug includes: switch means in said body and connected between one of said current carrying prongs and the respective wire connector means, said switch means being movable between switch-open and switch-closed positions; said body journaling said ground prong for longitudinal movement between a first position at which the ground prong extends more than said given distance from said body and a second position at which the ground prong extends approximately said given distance from said body; means engaging said body and said ground prong for resiliently urging said ground prong toward said first position and away from said second position; and switch operating means engaging said ground prong and said switch means for placing said switch means in switch-open position when said ground prong is in the first position and placing said switch means in switch-closed position when the ground prong is in the Second position; whereby when the plug is not in the socket the ground prong is in the first position and the switch means is in the switchopen position, and when the plug is inserted into the socket the means associated with the third way restricts the movement of the ground prong thereby moving the ground prong from the first to the second position and thus placing the switch means in the switch-closed position.
Claim 3
Dependent Claim
26 words
In an electrical plug as set forth in claim 1, wherein said switch operating means includes a spring urging the switch means toward the switch-open position.
Claim 4
Dependent Claim
113 words
In an electrical plug as set forth in claim 2, wherein said switch means includes a metal switch arm having a distal end and a proximal end, a first switch contact on the distal end, a second switch contact, means connecting the second switch contact to said one prong, and means connecting the switch arm to said respective wire connector means; and said switch operating means including cam means attached to said ground prong and engaging said switch arm for moving said switch arm to the switch-closed position against the urging of the spring of the switch operating means when the ground prong moves to the second position, thereby bringing the contacts together.
Claim 5
Dependent Claim
51 words
In an electrical plug as set forth in claim 3, wherein said proximal end of the arm is closer to said axis and farther from said body end than is the distal end of the arm, said cam means extending outwardly from said axis and contacting said arm between said ends.
Claim 6
Dependent Claim
62 words
In an electrical plug as set forth in claim 4, wherein there is a second switch means corresponding to the first recited switch means and connected between the other of the current carrying prongs and the respective wire connector means, the switch arms of the two switch means being on opposite sides of the axis, said cam means engaging both switch arms.
Claim 7
Dependent Claim
50 words
In an electrical plug as set forth in claim 1, wherein there is a second switch means corresponding to the first recited switch means and connected between the other of the current carrying prongs and the respective wire connector means, said switch operating means engaging both of said switch means.
Claim 8
Dependent Claim
116 words
In an electrical plug as set forth in claim 6, wherein each of said switch means includes a metal switch arm having a distal end and a proximal end, a first switch contact on the distal end, a second switch contact, means connecting the second switch contact to said one prong, and means connecting the switch arm to said respective wire connector means; and said switch operating means including cam means attached to said ground prong and engaging said switch arms for moving said switch arms to the switch closed position against the urging of the springs of the switch operating means when the ground prong moves to the second position, thereby bringing the contacts together.
Claim 9
Dependent Claim
52 words
In an electrical plug as set forth in claim 7, wherein the proximal ends of the arms are closer to said axis and farther from said body end than are the distal ends of the respective arms, said cam means extending outwardly from said axis and contacting said arms between said ends.
Claim 10
Dependent Claim
114 words
In an electrical plug as set forth in claim 1, wherein said switch means includes a metal switch arm having a distal end and a proximal end, a first switch contact on the distal end, a second switch contact, means connecting the second switch contact to said one prong, and means connecting the switch arm to said respective wire connector means; and said switch operating means including cam means attached to said ground prong and engaging said switch arm for moving said switch arm to the switch closed position against the urging of the spring of the switch operating means when the ground prong moves to the second position, thereby bringing the contacts together.
Claim 11
Dependent Claim
51 words
In an electrical plug as set forth in claim 9, wherein said proximal end of the arm is closer to said axis and farther from said body end than is the distaL end of the arm, said cam means extending outwardly from said axis and contacting said arm between said ends.
Claim 12
Dependent Claim
14 words
The combination of an electrical plug and socket as set forth in claim 1.
Claim 13
Dependent Claim
46 words
The combination as set forth in claim 11, wherein the way for the ground prong has an inner end and an outer end, said means for restricting movement of the ground prong comprising an abutment at the inner end of the way for the ground prong.
References Cited (Backward Citations)
US1564916A
Cited
US3846598A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |