GB2228148A - Electric plugs - Google Patents
Electric plugs Download PDFInfo
- Publication number
- GB2228148A GB2228148A GB8928760A GB8928760A GB2228148A GB 2228148 A GB2228148 A GB 2228148A GB 8928760 A GB8928760 A GB 8928760A GB 8928760 A GB8928760 A GB 8928760A GB 2228148 A GB2228148 A GB 2228148A
- Authority
- GB
- United Kingdom
- Prior art keywords
- cover
- plug
- pins
- reinforcing member
- base
- 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
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 17
- 230000007935 neutral effect Effects 0.000 claims description 5
- 239000013536 elastomeric material Substances 0.000 abstract description 5
- 239000000463 material Substances 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 239000004020 conductor Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 239000012815 thermoplastic material 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
- H01R13/46—Bases; Cases
- H01R13/502—Bases; Cases composed of different pieces
Landscapes
- Connector Housings Or Holding Contact Members (AREA)
Abstract
In an electrical plug of the kind where the contact pins (E, 8) are axially movable in the base 20 and the cover (1) when attached to the base retains the pins, a reinforcing member (3) separate from the cover is located axially between at least two (8) of the pins and the cover so that a flexible elastomeric material can be used for the cover when the plug is stressed. An insert (2) in the cover may be used to secure the member to the cover and provide a means of receiving a screw (19) to secure the cover to the base. <IMAGE>
Description
Electric Plugs
This invention relates to electrical plugs for connecting appliances to a mains supply via conventional socket outlets, such as the three pin plugs widely used within the United Kingdom.
Electrical plugs comnonly comprise a body including a base which carries the pins, terminals extending to contact pins for connection of the conductor wires, a fuse and a cable grip, and a cover which is secured to the base by a screw. The base and cover are often made of rigid plastics, but it is also well known for the cover to be made of impact resistant material, such as rubber or similar elastomeric material, to improve the resistance to damage due to impact forces, for example if the plug should be dropped onto a hard surface. In some such electrical plugs the pins are fixed to the base, but in others they are axially retained in the body by the cover the inside of which bears against the inner ends of the pins.In the case where the cover retains the pins, various standards apply to ensure that the cover is strong enough to prevent accidental forcing of the line and neutral pins through the cover. Furthermore, in order to meet these standards, the cover must still be effective after the plug has been submitted to overheating. When elastomeric material such as rubber is used for the cover,
it has been the practice to fix the pins to the base since the material tends to weaken when overheated. This arrangement where the pins are fixed increases the cost of the plug. A problem therefore exists in providing a sufficently strong cover for unfixed contact pins.
In order to overcome this problem it has been proposed to provide a substantially rigid reinforcing member which is partially embedded in the cover by moulding the latter in situ over the reinforcing member. However, the need to mould the cover over the insert is an inconvenience and complicates the manufacturing process.
An object of the present invention is, therefore, to provide a strong enough cover for an electrical plug which
is economic to manufacture.
An electrical plug according to the invention comprises a body including a base which mounts axially movable contact pins, a cover arranged to retain the pins within the body, and a reinforcing member separate from the cover, the member being locatable relative to the cover in a position so that at least a part of the member is axially between at least two pins and the cover. Preferably, the reinforcing member is secured to the cover by an insert extending through the cover.
In a preferred construction, the insert is adapted for snap engagement with the reinforcing member or a part thereof to fix the reinforcing member in place.
An embodiment of the invention will now be described with reference to the accompanying drawings, in which:
Fig. 1 is a top plan view of an electrical plug
according to the invention,
Fig. 2 is a sectional view taken at AA of the view of
Fig. 1 showing the inside of the plug, and
Fig. 3 is an enlargement of the sectional view of
Fig. 2.
An electrical plug (10), shown in Fig. 1, having a body (11) of any suitable known form is equipped with a cover (1) which is moulded from elastomeric material, such as rubber, or thermoplastic material. The cover is formed with a hole (12) in its top wall (13) which is suitably 3 nm or possibly 4 nm thick. A peripheral wall (14) of the cover (1) extends from the edge of the top wall to its base (15). A recess (16) extends around the hole in the outer surface of the cover (1) and, fitted into the hole
(12), is an insert (2) of plastic material having an enlarged head (17) received in the recess (16) and a shank
(18) with a blind bore (4) for receiving the end of a screw fastener (19) employed to secure the cover(1) onto the plug base (20) body.Axially movable in the base are three pins, namely earth pin (E), line pin (8) and neutral pin (8'). These pins are retained in the body (11) by means of pin heads (22) and the cover (1).
A reinforcing member (3) of substantially rigid'material, e.g., made as an injection moulding of high melting point polymer, is attached to the inside of the cover (1). The member (3) is generally flat and about 121 mn thick and of
T-shape configuration, the end portions or arms (24,25) of the cross-bar of the "T" being arranged to be located in axial alignment with the heads or ends of the line and neutral contact pins (8,8') and to provide firm abutments for supporting the pin heads (22) to prevent them damaging or distoring the cover (1). The leg (26) of the "T" has a hole (5) or an integral sleeve (not shown) at its free end, the hole or sleeve having a diameter to receive the shank of the insert (2) which, near its end is provided with an integral collar (6) which tapers towards the free end of the shank and defines a radial shoulder facing the head of the insert.When the leg (26) with its hole (5) is pushed onto the shank, it engages with a snap action behind the collar (6) so that the member (3) is securely attached against the inside surface of the cover (1).
Thus, the assembly of the cover parts (1,2,3) is a simple operation. Difficulties of embedding an insert in the cover during moulding are averted. Furthermore, the cover is reinforced in those areas at which it is at risk of being impaired by the pins without significant detraction from its impact resistance.
The insert (2) described above is suitable for use with a self-tapping screw. However, if a machine screw is to be used, the insert suitably has a metal threaded core.
Whilst normally the reinforcing member would only be located between the line and neutral pins and the cover, it is within the scope of the invention that the member also extends between the earth pin and the cover.
A particular advantage of the invention is that it enables the use of rubber or elastomeric material in the plug cover which would otherwise be unsuitable because of standards or statutory requirements for material carrying or supporting current carrying parts.
In the case of a non-rewirable plug where the plug cover
is welded to the base or even is moulded to the base, the insert may not be necessary and a suitable extension from the cover's inside can simply plug into a hole in the reinforcing member.
In another alternative arrangement (not shown) the reinforcing member may be simply inserted in a recess in the cover which is sufficent to hold the reinforcing member in place.
Claims (7)
1. An electrical plug comprising a body including a base which mounts axially movable contact pins, a cover arranged to retain the pins within the body, and a reinforcing member separate from the cover, the member being locatable relative to the cover in a position so that at least a part of the member is axially between at
least two pins and the cover.
2. A plug as claimed in claim 1 wherein the reinforcing member is secured to the cover.
3. A plug as claimed in claim 2 wherein the reinforcing member is secured to the cover by means of an insert extending through the cover.
4. A plug as claimed in claim 3 wherein the insert is adapted for snap engagement with the reinforcing member or a part thereof.
5. A plug as claimed in claim 3 or 4 wherein the base is secured to the cover by means of a screw extending from the base into the insert.
6. A plug as claimed in any one of claims 1 to 5 wherein the reinforcing member is "T" shaped, the arms of the "T" being mounted to the cover extending at least to a point between the line and neutral pins of the plug, the leg of the "T" extending to a point of securement to the cover.
7. An electrical plug substantially as described with reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB888829748A GB8829748D0 (en) | 1988-12-21 | 1988-12-21 | Electric plugs |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8928760D0 GB8928760D0 (en) | 1990-02-28 |
| GB2228148A true GB2228148A (en) | 1990-08-15 |
| GB2228148B GB2228148B (en) | 1993-06-30 |
Family
ID=10648841
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB888829748A Pending GB8829748D0 (en) | 1988-12-21 | 1988-12-21 | Electric plugs |
| GB8928760A Expired - Fee Related GB2228148B (en) | 1988-12-21 | 1989-12-20 | Electric plugs |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB888829748A Pending GB8829748D0 (en) | 1988-12-21 | 1988-12-21 | Electric plugs |
Country Status (2)
| Country | Link |
|---|---|
| GB (2) | GB8829748D0 (en) |
| MY (1) | MY104698A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2264814A (en) * | 1992-02-07 | 1993-09-08 | Mark Francis Vause | Retaining contact in plug |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0015760A1 (en) * | 1979-03-07 | 1980-09-17 | BICC Public Limited Company | An electric plug assembly and a method of manufacturing such assembly |
| EP0072104A1 (en) * | 1981-07-23 | 1983-02-16 | AMP INCORPORATED (a New Jersey corporation) | Sealed electrical connector |
-
1988
- 1988-12-21 GB GB888829748A patent/GB8829748D0/en active Pending
-
1989
- 1989-12-20 GB GB8928760A patent/GB2228148B/en not_active Expired - Fee Related
- 1989-12-21 MY MYPI89001839A patent/MY104698A/en unknown
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0015760A1 (en) * | 1979-03-07 | 1980-09-17 | BICC Public Limited Company | An electric plug assembly and a method of manufacturing such assembly |
| EP0072104A1 (en) * | 1981-07-23 | 1983-02-16 | AMP INCORPORATED (a New Jersey corporation) | Sealed electrical connector |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2264814A (en) * | 1992-02-07 | 1993-09-08 | Mark Francis Vause | Retaining contact in plug |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8928760D0 (en) | 1990-02-28 |
| MY104698A (en) | 1994-05-31 |
| GB8829748D0 (en) | 1989-02-15 |
| GB2228148B (en) | 1993-06-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19981220 |