GB2075278A - Cable sheath gripping devices - Google Patents
Cable sheath gripping devices Download PDFInfo
- Publication number
- GB2075278A GB2075278A GB8014707A GB8014707A GB2075278A GB 2075278 A GB2075278 A GB 2075278A GB 8014707 A GB8014707 A GB 8014707A GB 8014707 A GB8014707 A GB 8014707A GB 2075278 A GB2075278 A GB 2075278A
- Authority
- GB
- United Kingdom
- Prior art keywords
- lampholder
- sheath
- cap member
- stub
- cam portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000004020 conductor Substances 0.000 claims abstract description 21
- 239000011810 insulating material Substances 0.000 claims description 8
- 230000000717 retained effect Effects 0.000 claims description 2
- 239000002184 metal Substances 0.000 abstract description 7
- 229920003023 plastic Polymers 0.000 abstract description 4
- 239000004033 plastic Substances 0.000 abstract description 4
- 238000009413 insulation Methods 0.000 abstract 1
- POIUWJQBRNEFGX-XAMSXPGMSA-N cathelicidin Chemical compound C([C@@H](C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCC(O)=O)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H]([C@@H](C)CC)C(=O)NCC(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCC(O)=O)C(=O)N[C@@H](CC=1C=CC=CC=1)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](C(C)C)C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(O)=O)C(=O)N[C@@H](CC=1C=CC=CC=1)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H](CC(N)=O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C(C)C)C(=O)N1[C@@H](CCC1)C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H](CCC(O)=O)C(=O)N[C@@H](CO)C(O)=O)NC(=O)[C@H](CC=1C=CC=CC=1)NC(=O)[C@H](CC(O)=O)NC(=O)CNC(=O)[C@H](CC(C)C)NC(=O)[C@@H](N)CC(C)C)C1=CC=CC=C1 POIUWJQBRNEFGX-XAMSXPGMSA-N 0.000 description 7
- 229910001369 Brass Inorganic materials 0.000 description 1
- 241000220317 Rosa Species 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
- H01R13/58—Means for relieving strain on wire connection, e.g. cord grip, for avoiding loosening of connections between wires and terminals within a coupling device terminating a cable
- H01R13/59—Threaded ferrule or bolt operating in a direction parallel to the cable or wire
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R33/00—Coupling devices specially adapted for supporting apparatus and having one part acting as a holder providing support and electrical connection via a counterpart which is structurally associated with the apparatus, e.g. lamp holders; Separate parts thereof
- H01R33/05—Two-pole devices
- H01R33/46—Two-pole devices for bayonet type base
Landscapes
- Common Detailed Techniques For Electron Tubes Or Discharge Tubes (AREA)
Abstract
An electric lampholder has a sheath-gripping device 21 which relieves the conductors 17 from strain, including twisting, where they are connected to the terminals by means of a camming action. The holder also incorporates a snap-fit plastics cover 18 fitting over the terminals, providing full insulation where the component is assembled in a metal dome 13. <IMAGE>
Description
SPECIFICATION
Electric lampholder
This invention relates to electric lampholders. It is particuiarly concerned with lampholders adapted to receive an incandescent filament bulb, eg for domestic or office use.
Lampholders of this type may be fixedly attached to a light fitting or may be suspended from a ceiling rose. In many instances, a lampholder suspended from a ceiling fitting has no means of support other than the cable carrying the conductors. The cable may be a suitable sheathed flex incorporating separately insulated conductors.
Lampholders may be cased in either insulating material or metal, the metal typically having a brass finish for decorative purposes. Lampholders with insulating exteriors do not normally require a separate earth lead, but metal lampholders are normally required to be earthed by a separate lead, particularly if they incorporate a push-bar switch which is operated manually by the user.
There are certain potential hazards in the use of lampholders, as in all electrical appliances, if wiring and fitting requirements are not strictly adhered to.
In addition, with suspended lampholders, there is always the risk that undue stress may be put upon the termination of the conductors in the body of the lampholder by a pull on the lampholder or on a shade supported by the lampholder. The pulling out of the conductors may result in an electrical short circuit or other more serious accident.
It is an object of this invention to provide an improved lampholder which reduces the risk of the conductors being pulled out from the terminals. It is also an object to provide a lampholder which is protected from becoming live due to the contact of the metal cover by a live conductor.
According to one aspect of the invention we provide an electric lampholder adapted to be connected to electrical conductors carried within an insulating sheath, in which means is provided for gripping said sheath, said means being operable to grip the sheath by a camming action.
The gripping means may comprise a cap member and a stub having a cam portion, the stub being rotatable to urge the cam portion in use to grip the insulating sheath which carries the conductors between the cam portion and the cap member. The stub may suitably be cylindrical in shape.
The stub may be retained to the lampholder by the cap member and suitably has a head portion which extends through an orifice in the cap member. The cap member is preferably made of insulating material eg a plastics substance. The head portion of the stub may be slotted to be capable of receiving a screw-driver blade, the turning of which causes the sheath to be gripped. Instead of being slotted, the head portion may have laternative engagement means permitting the stub to be rotated by a suitable tool.
The cap member may have a bore for the sheath to pass through, the bore being stepped or undercut with a recessed portion on its underside such that the cam portion in operation deforms the sheath into the recessed portion. The surface of the cam portion which engages the sheath may be serrated, indented or corrugated so as to improve the gripping action on the sheath. Similarly the cap member may be serrated in the region in which the sheath passes through it so as to assist in the gripping action upon the sheath. The serrations or corrugations may run perpendicular to the direction of the sheath entry into the lampholder. Serrations in the cap member may run in the direction of the sheath entry to resist twisting of the sheath upon it being gripped.
The cap member may be constructed such that it can be fitted by snap action to the body of the lampholder. The cap member is of such shape that when the conductors are attached to the lampholder body, and the sheath is gripped by the gripping means, the conductor terminations are completely covered by the cap member. The cap member may be then covered by a metal dome which has an opening to receive the sheath which carries the conductors. The dome entry may be threaded so as to provide engagement for a similar threaded conduit carrying the insulating sheath and its conductors.
One embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 shows, partiy in cross-section, a lampholder according to the invention, and
Figure 2 shows a detail of the lampholderof Figure 1.
The lampholder has a body portion 10, made of insulating material, which houses electrical terminals (not shown) and resilient contacts 11 for engagement with an incandescent lamp bulb (not shown). A push-bar switch 12 may optionally be incorporated in the body portion 10.
A dome 13, made of insulating material or metal, covers the end of the holder away from the resilient contacts 11. Dome 13 has a centrally iocated entry at its head to permit a sheathed cable 14 to be passed through it. The dome entry is optionally threaded to receive the mating thread on the outside end of a rigid circuit 15. Where a conduit 15 is employed, it also performs the function of supporting the lampholder. It is desirable that where the sheathed cable 14 leaves the conduit, arrangements are made to protect the sheath from sharp edges eg on the conduit 15. A suitable arrangement for such protection includes placing a plastic bush (not shown) into the base of the conduit at its exit point into the lampholder. The sheathed cable 14 comprises a sheath 16 carrying within it separate conductors 17 and possibly an earth wire, the sheath being of insulating material.The sheath is in use cut back to expose the individual conductors 17, each separately insulated, and the conductors 17 are attached by screw or other suitable means to terminals (not shown) in the body portion 10 of the lampholder.
Acap 18 made of insulating material such as plastics is snap-fitted over the body portion 10 so as to cover the terminals. The snap fitting is effected by cap legs 19 snapping over abutments 20 positioned on the body portion 10. The shape of cap 18 is such that it fits within the dome 13, and also provides a cavity between itself and the body portion 10 through which the unsheathed conductors 17 may run to their terminals. There are two circular bores in the cap 18, one of which receives the sheathed cable 14 which has passed through the entry into the dome, and the other into which is fitted a cable gripping device 21, seen more clearly in Figure 2.
The cable gripping device 21 comprises a cylindrical stub with a cam portion 22 extending radially outwardly in its central region. Device 21 is prevented from becoming detached from the cap 18 by the abutment of a plane face of the cam portion 22 with the underside of cap 18. The curved surface of the cam portion has serrations 23 or is similarly indented or corrugated to provide an effective gripping surface. The end of the device 21 which passes through the bore in cap 18 has a slot 24 which enables the device to be rotated by means of a screwdriver or other suitable tool.
In use, once the conductors 17 have been connected to the terminals, cap 18 (previously slid onto cable 14) is snap fitted onto the body portion 10 with the cable gripping device 21 in such a position that the cam portion 22 does not engage the cable sheath
16. A screwdriver is inserted into slot 24and turned to urge the serrations 23 on cam portion 22 to grip the cable sheath 16 and to deform the sheath with its conductors into the undercut recessed portion 25 inside the cap 18. The re-entrant portion 25 has serrations similartothose on device 21 which assist in the gripping of the sheath. In this way the stress or tension in the fitting is not carried by the termination of the conductors 17, but by the engagement of the sheath 16 with the gripping device 21. The device 21 is of course made of insulating material.
In order to release the gripping of the sheath 16, the device 10 may simply be rotated by screwdriver to withdraw the cam portion 23 from the sheath.
Claims (11)
1. An electric lampholder adapted to be connected to electrical conductors carried within an insulating sheath, in which means is provided for gripping said sheath, said means being operable to grip the sheath by a camming action.
2. A lampholder as claimed in Claim 1 in which the gripping means comprises a cap member and a stub having a cam portion, the stub being rotatable to urge to cam portion in use to grip the insulating sheath which carries the connectors between the cam portion and the cap member.
3. A lampholder as claimed in Claim 2 in which the stub is cylindrical in shape.
4. A lampholderas claimed in Claim 2 or Claim 3 in which the stub is retained to the lampholder by the cap member.
5. A lampholder as claimed in Claim 4 in which the stub has a head portion which extends through an orifice in the cap member.
6. A lampholder as claimed in Claim 2 in which the cap member is made of an insulating material.
7. A lampholder as claimed in Claim 6 in which the head portion of the stub has suitable engagement means permitting the stub to be rotated by a suitable tool.
8. A lampholder as claimed in Claim 2 in which the cap member has a bore for the sheath to pass through, and the bore is stepped or undercut with a recessed portion on its underside such that a cam portion deforms the sheath into the recessed portion.
9. A lampholder as claimed in Claim 2 in which the surface cam portion which engages the sheath is serrated, indented or corrugated so as to improve the gripping action on the sheath.
10. A lampholder as claimed in Claim 2 in which the cap member is serrated, indented or corrugated in the region in which the sheath pases through it.
11. A lampholder as claimed in Claim 2 in which the cap member can be fitted by snap action to the body of the lampholder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8014707A GB2075278A (en) | 1980-05-02 | 1980-05-02 | Cable sheath gripping devices |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8014707A GB2075278A (en) | 1980-05-02 | 1980-05-02 | Cable sheath gripping devices |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2075278A true GB2075278A (en) | 1981-11-11 |
Family
ID=10513183
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8014707A Withdrawn GB2075278A (en) | 1980-05-02 | 1980-05-02 | Cable sheath gripping devices |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2075278A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2157898A (en) * | 1984-04-17 | 1985-10-30 | On Tat Bakelite Electric Works | Improvements in or relating to light holders |
| GB2179507A (en) * | 1985-08-23 | 1987-03-04 | Lucas Ind Plc | Cable gripping device |
| US5135404A (en) * | 1991-09-18 | 1992-08-04 | Cooper Industries, Inc. | Insulating liner for an electrical plug assembly |
| ES2149722A1 (en) * | 1998-11-16 | 2000-11-01 | Delgado Josep Comas | Lamp holder with connection cable safety device |
| CN109119812A (en) * | 2017-06-22 | 2019-01-01 | 富士康(昆山)电脑接插件有限公司 | cable connector assembly |
| CN109690879A (en) * | 2016-09-06 | 2019-04-26 | 菲尼克斯电动交通有限公司 | Plug-in connector parts with strain relief |
-
1980
- 1980-05-02 GB GB8014707A patent/GB2075278A/en not_active Withdrawn
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2157898A (en) * | 1984-04-17 | 1985-10-30 | On Tat Bakelite Electric Works | Improvements in or relating to light holders |
| GB2179507A (en) * | 1985-08-23 | 1987-03-04 | Lucas Ind Plc | Cable gripping device |
| US5135404A (en) * | 1991-09-18 | 1992-08-04 | Cooper Industries, Inc. | Insulating liner for an electrical plug assembly |
| ES2149722A1 (en) * | 1998-11-16 | 2000-11-01 | Delgado Josep Comas | Lamp holder with connection cable safety device |
| CN109690879A (en) * | 2016-09-06 | 2019-04-26 | 菲尼克斯电动交通有限公司 | Plug-in connector parts with strain relief |
| US10644442B2 (en) * | 2016-09-06 | 2020-05-05 | Phoenix Contact E-Mobility Gmbh | Plug connector part with strain relief |
| CN109690879B (en) * | 2016-09-06 | 2021-03-09 | 菲尼克斯电动交通有限公司 | Plug-in connector parts with strain relief |
| CN109119812A (en) * | 2017-06-22 | 2019-01-01 | 富士康(昆山)电脑接插件有限公司 | cable connector assembly |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5277602A (en) | Electrical plug and receptacle assembly | |
| JP3102892B2 (en) | Cable connection element | |
| US5975938A (en) | Quick connect electrical connector for multi conductor insulated cable wiring | |
| US4909761A (en) | In-line breakaway fuse holder | |
| US20070212908A1 (en) | Apparatus for distributing electrical power and/or communication signals | |
| US4070083A (en) | Electrical power line extension | |
| CN105580205A (en) | Electrical connection terminal | |
| US4503413A (en) | Spool for transformer in power supply device | |
| US20060065423A1 (en) | Compact flush-mount self-contained receptacle (SCR) | |
| GB2075278A (en) | Cable sheath gripping devices | |
| US20050142925A1 (en) | Quick cable connector for electrical devices and components | |
| WO1986003277A1 (en) | Ceiling roses | |
| US20030124893A1 (en) | Electrical safety outlet | |
| MX2007003763A (en) | Coaxial connector and method for connecting cable to same. | |
| US4251844A (en) | Fault indicator case and mount | |
| US6010356A (en) | Quick wire electrical socket with strain relief | |
| US4255010A (en) | Lamp socket assembly | |
| US5533916A (en) | Reverse wire termination device | |
| JP2002165351A (en) | Cable terminal part and cable terminal connect part using thereof | |
| GB2118380A (en) | An improved lampholder | |
| GB2323221A (en) | Electrical connectors and connecting parts therefor | |
| GB2245776A (en) | Lamp holders | |
| HU203619B (en) | Electric connecting terminal with clamping screw braked opposed to unscrewing | |
| GB2321790A (en) | A cam operated clamping terminal | |
| US6558184B1 (en) | Connector of the insulation-perforating type for a suspended electrical system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |