Plug for voltage adaptation

• US 3,996,546 A
• Filed: 01/27/1976
• Issued: 12/07/1976
• Est. Priority Date: 02/19/1975
• Status: Expired due to Term

• Current Assignee: Gillette Company (The Procter & Gamble Company)
• Original Assignee: Gillette Company (The Procter & Gamble Company)
• Inventors: Hugly, Jean-Daniel
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US05/652,716
• Time in Patent Office: 315 Days
• Field of Search: 336/105, 336/107, 336/192, 336/145, 336/146, 336/147, 323/48, 323/49, 339/31 M, 339/31 R, 339/32 R, 339/32 M, 339/33
• US Class Current: 336/107
• CPC Class Codes: H01R 27/00 Coupling parts adapted for co-operation with two or more dissimilar counterparts for dissimilar contact members H01R13/35; supported only by co-operation with a counterpart H01R31/00; with a holder adapted for supporting apparatus to which its counterpart is attached H01R33/90
• CPC Class Codes: Y10S 439/956 with means to allow selection of diverse voltage or polarity

Abstract

A dual-voltage electric plug comprising an insulating hollow casing having an opening, a terminal fitting within the casing, said fitting including four conducting terminal pins extending towards the opening in the casing, which four terminal pins are respectively connected or connectable to four conductors constituting two pairs across which are respectively connected two primary windings of a transformer having a common secondary winding, and an insulating insert insertable into the opening in the casing in either one of two differing orientations, said insert carrying live and neutral projecting socket pins for cooperation with a mains voltage socket, said insert also carrying connecting means located within the casing when the insert is in its inserted condition and for completing differing circuit paths through the socket pins and the terminal pins in the two respective orientations of the inserted insert, whereby in one orientation the two primary windings will be connected in series to provide a predetermined output secondary voltage derived from a mains voltage of one value and in the other orientation the two primary windings will be connected in parallel to provide the same predetermined output secondary voltage derived from a mains voltage of a second value.

Claims

1. A dual-voltage electric plug comprising an insulating hollow casing having an opening, a terminal fitting within the casing, said fitting including four conducting terminal pins extending towards the opening in the casing, which four terminal pins are respectively connected or connectable to four conductors constituting two pairs across which are respectively connected two primary windings of a transformer having a common secondary winding, and an insulating insert insertable into the opening in the casing in either one of two differing orientations, said insert carrying live and neutral projecting socket pins for cooperation with a mains voltage socket, said insert also carrying connecting means located within the casing when the insert is in its inserted condition and for completing differing circuit paths through the socket pins and the terminal pins in the two respective orientations of the inserted insert, whereby in one orientation the two primary windings will be connected in series to provide a predetermined output secondary voltage derived from a mains voltage of one value and in the other orientation the two primary windings will be connected in parallel to provide the same predetermined output secondary voltage derived from a mains voltage of a second value.

2. An electric plug as claimed in claim 1, wherein the insert is apertured to receive the ends of the terminal pins and the connecting means are in the form of electrically-conductive bridging elements incorporated in the body of the insert to provide differing combinations of connections between the socket pins and the terminal pins in the insert apertures according to the orientation in which the insert is inserted.

3. An electric plug as claimed in claim 2, in which the insert has six apertures for receiving terminal pins, a different two such apertures being unused in the respective orientations in which the plug may be inserted.

4. An electric plug as claimed in claim 3, in which the plug casing is symmetrical about an axial plane, the four terminal pins extending parallel to the axis, the first and second in said axial plane and the third and fourth laterally offset both to one side of said axial plane, the insert being slidably insertable in the axial direction in either one of two orientations obtainable one from the other by rotating the insert through 180°

about the axis, the insert having first and second apertures in the axial plane which receive the first and second terminal pins in each orientation and third and fourth, and fifth and sixth, apertures laterally offset in pairs on opposite sides of the axial plane, the third and fourth apertures receiving the third and fourth terminal pins in one orientation of the insert and fifth and sixth apertures receiving the third and fourth terminal pins in the other orientation.

5. An electric plug as claimed in claim 4, in which the respective transformer primary windings are connected across the conductors connected or connectable to the first and third and to the fourth and second terminal pins, the insert incorporating first and second bridging elements connecting the respective socket pins to the first and second terminal pins in one orientation of the inserted insert and to the second and first terminal pins in the other orientation, a third bridging element connecting the third and fourth terminal pins in the said one orientation of the insert and fourth and fifth bridging elements respectively connecting the first and fourth and the third and second terminal pins in the said other orientation.

6. An electric plug as claimed in claim 5, in which the insert carries a second pair of live and neutral socket pins projecting oppositely from the first-mentioned pair of socket pins to be received in the plug casing when the said first-mentioned pair of socket pins are exposed for cooperation with a mains voltage socket, the two pairs of socket pins being adapted to differing standards in respect of their dimensions and/or relative positions, and the insert being reversibly insertable into the casing with either one pair of socket pins exposed, in each case in either one of two differing orientations respectively associated with differing mains voltages.

7. An electric plug as claimed in claim 6, wherein the third bridging element also acts to connect the third and fourth terminal pins in one orientation of the inserted insert when the second pair of socket pins are exposed, and the insert incorporates sixth and seventh bridging elements respectively connecting the first and fourth terminal pins and the third and second terminal pins in the other orientation when the second pair of socket pins are exposed.

8. An electric plug as claimed in claim 1, in which the insert carries a second pair of live and neutral socket pins projecting oppositely from the first-mentioned pair of socket pins to be received in the plug casing when the said first-mentioned pair of socket pins are exposed for cooperation with a mains voltage socket, the two pairs of socket pins being adapted to differing standards in respect of their dimensions and/or relative positions, and the insert being reversibly insertable into the casing with either one pair of socket pins exposed, in each case in either one of two differing orientations respectively associated with differing mains voltages.

9. An electric plug as claimed in claim 1, in combination with the transformer having two primary windings and the conductors connected thereto, said transformer and conductors being accommodated in the plug casing.

10. An electric plug as claimed in claim 1, including releasable locking means for locking the insert in its inserted position in the casing.

11. An electric plug as claimed in claim 1, wherein the internal cross-section of the opening in the casing and the external cross-section of the insert have the same non-circular shape selected to ensure that the connecting means is operative to complete the correct circuit path when the insert is inserted into the casing.