GB2109179A - An improved electric plug assembly - Google Patents
An improved electric plug assembly Download PDFInfo
- Publication number
- GB2109179A GB2109179A GB08231314A GB8231314A GB2109179A GB 2109179 A GB2109179 A GB 2109179A GB 08231314 A GB08231314 A GB 08231314A GB 8231314 A GB8231314 A GB 8231314A GB 2109179 A GB2109179 A GB 2109179A
- Authority
- GB
- United Kingdom
- Prior art keywords
- base
- preformed base
- preformed
- pin
- plug assembly
- 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.)
- Granted
Links
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
- H01R24/00—Two-part coupling devices, or either of their cooperating parts, characterised by their overall structure
- H01R24/28—Coupling parts carrying pins, blades or analogous contacts and secured only to wire or cable
- H01R24/30—Coupling parts carrying pins, blades or analogous contacts and secured only to wire or cable with additional earth or shield contacts
-
- 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
- H01R13/648—Protective earth or shield arrangements on coupling devices, e.g. anti-static shielding
- H01R13/652—Protective earth or shield arrangements on coupling devices, e.g. anti-static shielding with earth pin, blade or socket
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R2103/00—Two poles
Landscapes
- Connector Housings Or Holding Contact Members (AREA)
Abstract
In a moulded-on electric plug assembly of the kind in which the plug pins 12, 13, 14 protrude through holes 2, 3, 4 in a preformed base 1 with shoulders 15, 16, 17 on the pins bearing against the front face of the base to limit the extent of protrusion of the pins, the base has, associated with each of the holes, integral flexible lugs 22, 23, 24 with which the plug pins effect snap fits to hold the pins in position in the holes with the shoulders on the pins bearing against the front face of the base. <IMAGE>
Description
SPECIFICATION
An improved electric plug assembly
This invention relates to an electric plug assembly of the kind in which the plug pins and associated conductor terminals are mounted in a preformed base of electrically insulating material, the conductors of a length of flexible insulated multi-conductor cable are electrically connected to appropriate terminals of the plug, and a moulded plug body of electrically insulating material wholly or partialy encapsulates the preformed base and the plug pins and associated conductor terminals with an appropriate length of each pin protruding from the plug assembly and is permanently bonded to the insulating covering of a part of the length of cable. Electric plug assemblies of th is kind will hereinafter, for convenience, be referred to as "of the kind described".
Three pin electric plug assemblies of the kind described are especially suitable for use with domestic applicances because such appliances can be sold to the public with the electric plug permanently bonded to the flexible cable of the appliance, thereby eliminating the risk that an unskilled user of an appliance may connect a conventional three pin plug to an end of the flexible cable of the appliance in an incorrect manner which, when the appliance is used, may result in injury to the user and/or permanent damage to the appliance.
It is the object of the present invention to provide an improved electric plug assembly of the kind described which is simpler in construction and thereby less expensive to manufacture than electric plug assemblies of the kind described hitherto proposed and used.
According to the invention, the improved electric plug assembly of the kind described comprises a preformed base of electrically insulating material having holes therethrough in which are fitted plug pins which protrude from the rear face of the preformed base and each of which has at least one shoulder bearing against the front face of the preformed base to limit the extent of protrusion of the pin; means integral with the preformed base and associated with each of the holes passing therethrough with which the plug pins effect snap fits to hold the pins in position in the holes of the shoulders bearing against the front face of the preformed base; and a moulded body of electrically insulating material which wholly encapsulates the conductorterminals associated with the plug pins and which wholly or partially encapsulates the preformed base and is bonded to the insulating covering of an adjacent part of the flexible cable.
Preferably, the preformed base has, adjacent each hole therethrough, at least one flexible lug which is integral with the preformed base and which is of such a shape that it permits passage of a pin through the hole in a direction from the front face to the rear face of the preformed base and which has a shoulder which bears against a part of a pin to retain the pin in position in the hole with the shoulder or shoulders of the pin bearing against the front face of the preformed base. Preferably, also, the or each flexible lug associated with each hole through the preformed base constitutes-a part of the boundary wall of the hole.
Where, as is preferred, the plug assembly includes means for electrically connecting a cartridge fuse between the live pin and the its associated conductor terminal and said means comprises two spaced substantially U-shaped resilient electrical contacts, one of which is electrically connected to the live pin and the other to its associated conductor terminal before they are introduced into the preformed base and whose limbs are introduced from the front face of the base through two pairs of slots extending through the base so that the limbs of the electrical contacts protrude into a cartridge fuse recess in the rear face of the base, preferably the preformed base has, associated with each said U-shaped electrical contact, means integral with the preformed base with which the electrical contact effects a snap fit to hold the electrical contact in position in the slots with the contact bearing against the front face of the preformed base and with the limbs of the contact protruding into the cartridge-fuse recess. Preferably, two flexible lugs are associated with at least one pair of slots through which the limbs of an electrical contact protrude into the cartridge4use recess, one flexible lug having a shoulder engaging the base of one limb of the electrical contact and the other flexible lug having a shoulder engaging the base of the other limb of the electrical contact, the flexible lugs being of such a shape that they permit insertion of the electrical contact from the front face of the preformed base towards the rear face thereof and, when the electrical contact is in position, effect snap engagement with the contact to hold it in said position.
The preformed base may be made of any suitable electrically insulating material that has sufficient inherent flexibility to enable lugs integral with the base to be formed for effecting a snap engagement with a pin or electrical contact of the plug assembly.
It is preferred to make the preformed base of a glass-filled polypropylene.
It has been found that, in manufacturing electric plug assemblies of the kind described, there is a risk that, during moulding of the plug body, a wire or wires of the exposed end of a cable conductor connected to one of the terminals will become detached from the terminal and will protrude through the moulded plug body. A plug assembly which is connected to a domestic electrical appliance and which has a live wire or wires protruding through the plug body is extremely dangerous, especially if handled with damp hands - as may be the case when the plug assembly is connected to a domestic washing machine.
Accordingly, the improved electric plug assembly of the present invention preferably incorporates means which will eliminate or at least substantially reduce any risk of a wire or wires protruding through the plug body. In one preferred embodiment, the moulded body of the plug consists of two separately formed parts, an inner moulded body of electrically insulating materi l which wholly encapsulates at least the conductor terminals associated with the live and neutral pins, and preferably the conductor terminals associated with all the plug pins, and an outer moulded body of electrically insulating material which wholly or partially encapsulates the inner moulded body and is bonded to the insulating covering of an adjacent part of the flexible cable.
Where, for example, the outer moulded body is of urea or polyester, preferably the inner moulded body is of nylon, polyvinyl chloride or polyester. The inner moulded body may be of a colour different and readily distinguishable from that of the outer moulded body and, preferably, at least a part of the inner moulded body is visible to provide an indication that an inner moulded body is present within the plug.In another embodiment of the invention, a preformed cover of an electrically insulating material that is substantially harder than the moulded insulating material of the plug body is encapsulated within the moulded plug body and is connected to the preformed base in which the plug pins and associated conductorterminals are mounted in such asto overlie at least the live and neutral terminals, and preferably all of the terminals, thereby to form a guard between said terminals and the outer surface of the moulded plug body. In this case, preferably the preformed cover is initially detachably connected to the preformed base in which the plug pins and associated conductor terminals are mounted and, in a preferred embodiment, the preformed cover has protuberances which are snap fits in appropriately located holes or recesses in the preformed base.
The invention also includes, for use in an improved electric plug assembly, a preformed base of electrically insulating material having holes therethrough for reception of plug pins and having, associated with each hole, means integral with the
preformed base which, when a pin is inserted into one of the holes from the front face of the preformed base towards the rear face thereof, will effect a snap engagement with the pin to hold the pin in position in the hole with a shoulder or shoulders on the pin bearing against the front face of the preformed base.
The invention is further illustrated by a description, by way of example, of a preferred 13 amp three-pin plug assembly of the kind described with
reference to the accompanying drawings, in which Figure lisa plan view of the preformed base of the plug assembly with the pins and cartridge fuse contacts mounted therein;
Figure 2 is a sectional side view of the preformed
base taken on the line ll-ll in Figure 1;
Figure 3 is a sectional side view of the preformed
base taken on the line Ill-Ill in Figure 1, and
Figure 4 is a sectional side view of the preformed
base taken on the line IV-IV in Figure 1.
Referring to the drawings, the improved electric
plug assembly comprises a preformed base 1 of a
glass-filled polypropylene having therethrough a
hole 2 for reception of a live pin 12, a hole 3 for
reception of a neutral pin 13 and a hole 4 for
reception of an earth pin 14. Each ofthe pins 12,13
and 14 is of hollow form and protrudes from the rear
face of the preformed base 1, the pin 12 having two shoulders 15, the pin 13 having two shoulders 16 and the pin 14 having two shoulders 17, all of which shoulders bear against the front face of the base. The pin 13 has an integral ferrule 18 for connection to the neutral conductor of a flexible three core cable (not shown); the pin 14 has an integral ferrule 19 for connection to the earth conductor of the cable.
The preformed base 1 has, adjacent the hole 2, a flexible lug 22 which is integral with the base and which has a shoulder 25 that bears against a part of the pin 12 to retain the pin in position in the hole with the shoulders 15 bearing against the front face of the base. The flexible lug 22 is of such a shape that it permits passage of the pin 12 through the hole 2 in a direction from the front face to the rear face of the preformed base 1 and effects a snap fit with the pin to hold the pin in position in the hole with the shoulders 15 of the pin bearing against the front face of the base.Similarly, the preformed base 1 has, adjacent the hole 3, an integral flexible lug 23 having a shoulder 26 retaining the pin 13 in position and, adjacent the hole 4, an integral flexible lug 24 having a shoulder 27 retaining the pin 14 in position, the flexible lugs 23 and 24 operating in the same manner as the flexible lug 22.
The preformed base 1 has, in the rear face of the base between the holes 2 and 3 and the hole 4, a cartridge fuse recess 5 and has two pairs of slots 6 and 7 which extend through the base and open into the cartridge fuse recess. Positioned in the pair of slots 6 is a substantially U-shaped resilient electric fuse clip 20 whose limbs protrude into the cartridge fuse recess 5 and which has an integral ferrule 21 for electrically connecting the fuse clip to the live conductor of the flexible three core cable. The fuse clip 20 is retained in position by two flexible lugs 28 which are integral with the base 1 and which have shoulders 29 bearing against the base of the clip.
The flexible lugs 28 are of such a shape that they permit passage of the limbs of the clip 20 through the slots 6 in a direction from the front face to the rear face of the preformed base 1 and effect snap fits with the base of the clip to hold it in position in the slots with the shoulders 29 of the lugs bearing against the base of the clip.
The live pin 12 has a tongue 30 which is spot welded to the base of a substantially U-shaped resilient fuse clip 38 whose limbs protrude through the pair of slots 7 into the cartridge fuse recess 5. The fuse clip 38 is retained in position by a flexible lug 39 which is integral with the preformed base 1 and which has a shoulder 40 bearing against the tongue 30 integral with the live pin 12. The flexible lug 39 is of such a shape that it permits passage of the limbs of the fuse clip 38 through the slots 7 in the direction from the front face to the rear face of the preformed base and effects a snap fit with the tongue 30 to hold the fuse clip in position in the slots with the shoulder 40 ofthe lug bearing againstthetongue.
The conductor terminals associated with all the plug pins are wholly encapsulated in an inner moulded body of electrically insulating material (not shown) and an outer moulded body of electrically
insulating material (not shown) partially encapsu
lates the inner moulded body and is bonded to the insulating covering of an adjacent part of the flexible three core cable.
Since the plug pins and fuse clips are retained in position in the preformed base by resilient lugs integral with the base, the preformed base with the pins and fuse clips mounted in it can be transported within a factory to a machine for moulding the plug body with negligible risk that a pin or fuse clip will be displaced.
Claims (17)
1. An electric plug assembly ofthe kind described comprising a preformed base of electrically insulating material having holes therethrough in which are fitted plug pins which protrude from the rear face of the preformed base and each of which has at least one shoulder bearing against the front face of the preformed base to limit the extent of protrusion of the pin; means integral with the preformed base and associated with each of the holes passing therethrough with which the plug pins effect snap fits to hold the pins in position in the holes with the shoulders bearing against the front face of the preformed base; and a moulded body of electrically insulating material which wholly encapsulates the conductor terminals associated with the plug pins and which wholly or partially encapsulates the preformed base and is bonded to the insulating covering of an adjacent part of the flexible cable.
2. An electric plug assembly of the kind described comprising a preformed base of electrically insulating material having holes therethrough in which are fitted plug pins which protrude from the rear face of the preformed base and each of which has at least one shoulder bearing against the front face of the preformed base to limit the extent of protrusion of the pin and having, adjacent each hole therethrough, at least one flexible lug which is integral with the preformed base, which flexible lug is of such a shape that it permits passage of a pin through the hole in a direction from the front face to the rear face of the preformed base and which has a shoulder which bears against a part of a pin to retain the pin in position in the hole with the shoulder or shoulders of the pin bearing against the front face of the preformed base; and a moulded body of electrically insulating material which wholly encapsulates the conductor terminal associated with the plug pins and which wholly or partially encapsulates the preformed base and is bonded to the insulating covering of an adjacent part of the flexible cable.
3. An electric plug assembly as claimed in Claim 2, wherein the or each flexible lug associated with each hole through the preformed base constitutes a part of the boundary wall of the hole.
4. An electric plug assembly as claimed in any one of the preformed Claims which includes means for electrically connecting a cartridge fuse between the live pin and its associated conductor terminal and said means comprises two spaced substantially
U-shaped resilient electrical contacts, one of which is electrically connected to the live pin and the other to its associated conductor terminal before they are introduced into the preformed base and whose
limbs are introduced from the front face of the base through two pairs of slots extending through the
base so that the limbs of the electrical contacts
protrude into a cartridge fuse recess in the rear face of the base, wherein the preformed base has, associated with each of said electrical contact, means integral with the preformed base with which the electrical contact effects a snap fit to hold the electrical contact in position in the slots with the contact bearing against the front face of the preformed base and with the limbs of the contact protruding into the cartridge-fuse recess.
5. An electric plug assembly as claimed in Claim 4, wherein two flexible lugs are associated with at least one pair of slots through which the limbs of an electrical contact protrude into the cartridge-fuse recess, one flexible lug having a shoulder engaging the base of one limb of the electrical contact and the other flexible lug having a shoulder engaging the base of the other limb of the electrical contact, the flexible lugs being of such a shape that they permit insertion of the electrical contact from the front face of the preformed base towards the rear face thereof and, when the electrical contact is in position, effect snap engagement with the contact to hold it in said position.
6. An electric plug assembly as claimed in any one of the preceding Claims, wherein the preformed base is made of a glass-filled polypropylene.
7. An electric plug assembly as claimed in any one of the preceding Claims, wherein the moulded body of the plug consists of two separately formed parts, an inner moulded body of electrically insulating material which wholly encapsulates at least the conductor terminals associated with the live and neutral pins, and an outer moulded body of electrically insulating material which wholly or partially encapsulates the inner moulded body and is bonded to the insulating covering of an adjacent part of the flexible cable.
8. An electric plug assembly as claimed in Claim 7, wherein the inner moulded body of electrically insulating material wholly encapsulates the conductor terminals associated with all the plug pins.
9. An electric plug assembly as claimed in Claim 7 or 8, wherein the inner moulded body is of a colour different and readily distinguishable from that of the outer moulded body and at least part of the inner moulded body is visible to provide an indication that an inner moulded body is present within the plug.
10. An electric plug assembly as claimed in any one of Claims 1 to 6, wherein a preformed cover of an electrically insulating material that is substantially harder than the moulded insulating material of the plug body is encapsulated within the moulded plug body and is connected to the preformed base in which the plug pins and associated conductor terminals are mounted in such a way as to overlie at least the live and neutral terminals thereby to form a guard between said terminals and the outer surface of the moulded plug body.
11. An electric plug assembly as claimed in
Claim 10, wherein the preformed cover overlies all the plug pin terminals.
12. An electric plug assembly as claimed in
Claim 10 or 11, wherein the preformed cover is initially detachably connected to the preformed base in which the plug pins and associated conductor terminals are mounted.
13. An electric plug assembly as claimed in
Claim 12, wherein the preformed cover has protuberances which are snap fits in appropriately located holes or recesses in the preformed base.
14. For use in an electric plug assembly as claimed in any one of the preceding Claims, a preformed base of electrically insulating material having holes therethrough for reception of plug pins and having, associated with each hole, means integral with the preformed base which, when a pin is inserted into one of the holes from the front face of the preformed base towards the rear face thereof, will effect a snap engagement with the pin to hold the pin in position in the hole with a shoulder or shoulders on the pin bearing against the front face of the preformed base.
15. For use in an electric plug assembly as claimed in any one of Claims 1 to 13, a preformed base of electrically insulating material having holes therethrough for reception of plug pins and having, adjacent each hole, at least one flexible lug which is integral with the preformed base and which is of such a shape that it will permit passage of a pin through the hole in a direction from the front face to the rear face of the preformed base and which has a shoulder which will bear against a part of a pin to retain the pin in position in the hole with a shoulder or shoulders on the pin bearing against the front face of the preformed base.
16. For use in an electric plug assembly as claimed in any one of Claims 1 to 13, a preformed base substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
17. An electric plug assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08231314A GB2109179B (en) | 1981-11-03 | 1982-11-02 | An improved electric plug assembley |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8133150 | 1981-11-03 | ||
| GB08231314A GB2109179B (en) | 1981-11-03 | 1982-11-02 | An improved electric plug assembley |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2109179A true GB2109179A (en) | 1983-05-25 |
| GB2109179B GB2109179B (en) | 1985-03-27 |
Family
ID=26281154
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08231314A Expired GB2109179B (en) | 1981-11-03 | 1982-11-02 | An improved electric plug assembley |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2109179B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2274026B (en) * | 1992-05-15 | 1996-09-25 | Kainstar Limited | Electrical plug assembly |
| AU688253B3 (en) * | 1997-06-13 | 1998-03-05 | Wang-Feng Chu | Plug |
-
1982
- 1982-11-02 GB GB08231314A patent/GB2109179B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2274026B (en) * | 1992-05-15 | 1996-09-25 | Kainstar Limited | Electrical plug assembly |
| AU688253B3 (en) * | 1997-06-13 | 1998-03-05 | Wang-Feng Chu | Plug |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2109179B (en) | 1985-03-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4083617A (en) | Electrical connector | |
| US6146207A (en) | Coupling element for two plugs, adapted male and female elements and coupling device obtained | |
| US5026305A (en) | Connector for reed switch or similar electrical component | |
| JP4074691B2 (en) | Plug bridge for appliance plugs having a pair of conductive pins and optionally a ground pin | |
| GB2095924A (en) | An electric plug | |
| EP0016269B1 (en) | An improved electric plug assembly | |
| JPH04319275A (en) | Plug connector | |
| US3126242A (en) | Molded female connector | |
| EP0015760B1 (en) | An electric plug assembly and a method of manufacturing such assembly | |
| GB2072436A (en) | Pre-wired plug | |
| GB2110587A (en) | Making a non-rewirable plug | |
| GB2109179A (en) | An improved electric plug assembly | |
| US4176902A (en) | Method for fusing male plug at end of power line cord | |
| US3533052A (en) | Electrical cord plugs | |
| GB2085242A (en) | An improved electric connector assembly | |
| US4333702A (en) | Low cost high voltage connector | |
| GB2050076A (en) | An improved electric plug assembly | |
| EP0015759A1 (en) | An improved electric connector assembly | |
| USRE31017E (en) | Method for fusing male plug at end of power line cord | |
| JPH04220971A (en) | Electrical plug connector | |
| GB1604425A (en) | Electric plug assembly | |
| JPH03687Y2 (en) | ||
| JPH084021B2 (en) | Telephone cable connector | |
| GB2094569A (en) | A moulded electrical connector | |
| GB1604426A (en) | Method of manufacturing an electric plug assembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |