Combination plug and power cut-off unit

• US 4,086,643 A
• Filed: 04/05/1976
• Issued: 04/25/1978
• Est. Priority Date: 04/05/1976
• Status: Expired due to Term

• Current Assignee: JDS Products, Inc.
• Original Assignee: JDS Products, Inc.
• Inventors: Jacobs, David A.
• Primary Examiner(s): Salce, Patrick R.
• Application Number:
  US05/673,397
• Time in Patent Office: 750 Days
• Field of Search: 317/18 A, 317/18 R, 317/18 D, 317/9 A, 317/9 AC, 317/9 R, 317/9 D, 317/137, 317/154, 317/31, 340/147 R, 340/147 LP, 339/14 P, 339/176 R, 339/176 MP, 361/88, 361/90, 361/92, 361/1, 361/23, 361/33, 361/331, 361/335, 361/356, 361/357, 361/351, 361/376, 361/417, 361/115, 174/52 R, 200/51 R, 200/51.11
• US Class Current: 361/92
• CPC Class Codes: H01H 83/12 operated by voltage falling below a predetermined value, e.g. for no-volt protection
• CPC Class Codes: H01R 13/713 the switch being a safety switch

Abstract

A combination electrical plug and cord and power cut-off unit with a male electrical plug rigidly secured to a housing from which the cord extends, the housing serving as a hard grip for insertion and removal of the plug, the housing containing an electrical relay holding circuit including an externally accessible momentary contact switch wherein a power failure in the supply line will effect a disconnect of the relay requiring a manual actuation of the switch to restore power to the cord leading to a machine or other electrical accessory.

Claims

1. A combination plug and power cut-off unit for safety control of power operated devices which comprises:

(a) an elongate shell housing,

(b) a male plug body having electrical contact prongs and provided with an annular recess to receive peripheral portions of an opening in the end of said shell to mechanically lock said plug body in said shell with the prongs outstanding,

(c) a power line retainer at the other end of said shell to mount the end of a power line to carry electrical current to an electrically operated device,

(d) a manually operated push-button type, normally open, switch mounted at said other end of said shell having a push-button outstanding from said shell, and

(e) a relay coil and contacts within said shell to provide a holding circuit around said manually operated switch when power is present in a line into which said prongs are plugged.

2. A combination plug and power cut-off unit for safety control of power operated devices which comprises:

(a) an elongate shell housing having a dimension to permit easy gripping by the hand,

(b) a male plug prong unit mechanically mounted in one wall of said shell with prongs outstanding and adapted to be plugged into a source of electrical power,

(c) a power line including a plurality of conductors passing through another wall of said shell to provide power to an operating device,

(d) a relay comprising a relay coil connected across said power line and a normally open relay switch connected in series with said relay coil across two of said prongs, said normally open relay switch also being connected between one of said two prongs and a selected one of said conductors, and

(e) a reset switch comprising an operating member projecting from a wall of said shell and means responsive to actuation of said operating member to provide a current path between said two of said prongs through said relay coil, such that actuation of said operating member energizes a relay holding circuit comprising said relay coil and relay switch to conduct power from said prongs to said power line as long as said prongs are connected to electrical power, interruption of power at said prongs deenergizing said holding circuit and disconnecting power from said power line until said holding circuit is reenergized by actuation of said reset switch.

3. A combination plug and power cut-off unit for safety control of power operated devices which comprises:

(a) an elongate shell housing having a dimension to permit easy gripping by the hand,

(b) a male plug prong unit mechanically mounted in one wall of said shell with prongs outstanding and retained in said one wall by an interlock between the periphery of a hole in said shell and an annular recess in said unit,

(c) a power line passing through another wall of said shell to provide power to an operating device,

(d) a relay coil and relay contacts mounted within said shell,

(e) a reset switch mounted in a wall of said shell having an operating member projecting from said shell, and

(f) a circuit connecting said prongs, power line, coil, relay contacts and reset switch wherein said relay coil and contacts provide a holding circuit to conduct power from the prongs to the line as long as the prongs are connected to power.

4. A combination plug and power cut-off unit for safety control of power operated devices which comprises:

(a) an elongate shell,

(b) means including a plurality of first conductive means carried by one wall of said shell and adapted to be connected to a source of electrical power,

(c) means including a plurality of second conductive means carried by another wall of said shell to provide power to an operating device,

(d) relay means mounted within said shell comprising a normally open switch and means connected in series with said normally open switch across two of said first conductive means and responsive to a current conducted therethrough to close said normally open switch, said normally open switch also being connected between one of said two first conductive means and a selected one of said second conductive means, and

(e) reset switch means comprising an operating member projecting from a wall of said shell and means responsive to actuation of said operating member to provide a current path between said two of said first conductive means through said current responsive means, such that actuation of said operating member energizes a relay holding circuit comprising said current responsive means and said normally open switch to conduct power from said first conductive means to said second conductive means as long as said first conductive means are connected to electrical power, interruption of power at said first conductive means deenergizing said holding circuit and disconnecting power from said second conductive means until said holding circuit is reenergized by actuation of said reset switch means.

5. The combination set forth in claim 4 wherein said plurality of first conductive means is carried in said shell by means retained by an interlock between the periphery of a hole in said shell and an annular recess in said carrying means.

6. A combination plug and power cut-off unit for safety control of power operated devices which comprises:

(a) an elongate shell housing having a dimension to permit easy gripping by the hand,

(b) a male plug prong unit mechanically mounted in one end wall of said shell housing with prongs outstanding,

(c) a power line passing through another end wall of said shell housing to provide power to an operating device,

(d) a relay mounted within said shell housing and comprising a normally open switch and means connected in series with said normally open switch across two of said prongs and responsive to a current conducted therethrough to close said normally open switch,

(e) a reset switch comprising an operating member projecting from said other end wall of said shell housing and means responsive to actuation of said operating member to provide a current path between said two of said prongs through said current responsive means, and

(f) a circuit connecting said prongs, power line, relay and reset switch wherein said relay provides a holding circuit to conduct electrical power from the prongs to the line as long as the prongs are connected to such electrical power.