GB2264402A

GB2264402A - Two-component lampholder

Info

Publication number: GB2264402A
Application number: GB9301408A
Authority: GB
Inventors: C R Mileman
Original assignee: CARODON MK ELECTRIC Ltd; MK Electric Ltd
Current assignee: CARODON MK ELECTRIC Ltd; Novar ED&S Ltd
Priority date: 1992-01-25
Filing date: 1993-01-25
Publication date: 1993-08-25
Anticipated expiration: 2013-01-25
Also published as: GB9201657D0; GB9301408D0; GB2264402B

Abstract

A lampholder comprising a first component (2) which has terminals (6, 8) for connection to a supply cable (10) and a first pair of electrical contacts (16, 18); a second component (4) has a lamp connector (68) and lamp contacts (52) electrically connected to a second pair of contacts (44, 46). The components (2, 4) may electrically disconnect by movement at right angles to the axis (X) of a lamp (57) connected to the lampholder. Interlocks (43', 60) may be provided to prevent the components (2, 4) from being coupled without a lamp (57) being inserted in the second component and to prevent the lamp being removed whilst the components are coupled. The first component (2) may have a shutter (20) actuated by the second (4). <IMAGE>

Description

LAMPHOLDER The present invention relates to lampholders.

Lampholders particularly bayonet fitting lampholders have long been recognised as being potentially dangerous because when the lamp is removed the contacts can be touched.

Since these may well be live, the result can be fatal.

There is of course a high risk with inquisitive children particularly when the lampholder is readily accessible in the case of a table lamp.

Safety lamp holders have been designed to switch off automatically when the lamp is removed but it is still possible, albeit difficult, to override the safety mechanism. The switch status in such designs is not evident and the contacts still be accessible.

Accordingly a safety lampholder according to the invention comprises a first component comprising supply terminals electrically connected to a first pair of contact means and a second component comprising a lamp holding means having a pair of lamp contacts electrically connected to a second pair of contact means which can make contact with the first pair, the first component being separable from the second component so as to electrically separate the contact between the first and second pair of contact means.

Preferably the components are arranged to join together in a direction substantially at right angles to the bulb axis.

In an embodiment of the invention means are provided to prevent bulb removal when the components are joined and a further means is provided to shutter the first pair of contact means from exterior access when the components are separated, the shuttering means also preventing the coupling of the first and second pairs of contact means in the absence of a lamp in the second component. A dummy lamp arranged to cover and isolate the lamp holder contacts may be provided to enable the components to be sold in a joined condition.

An embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a diametrical cross section of a lampholder according to the invention with two components separated, and Figure 2 is a side view of a dummy lamp for insertion into the lampholder of Fig. 1 In Figure 1 a lampholder 1 is shown with a first half or first component 2 separated from a second half or second component 4.

The first component has supply terminals 6 and 8, for supply cable 10. This is gripped by a suitable cord grip shown diagrammatically at 12. The terminals 6 and 8 are connected by conductors 14 to a first pair of electrical contact means being a pair of sockets 16 and 18 aligned with connection axis Y and at right angles to lamp axis X.

The sockets are protected from exterior access by means of a shutter 20 urged into a shuttering position as shown in Fig. 1 by a compression spring 22. Holes 24 and 26 with the shutter 20 align with sockets 16 and 18 when the shutter is urged into an upper open position as will be described. The first component has a main body section 28 to which an upper terminal cover 30 is screwed by threading at 32. The terminal cover could however be slid into the Y axis direction so that the supply cable can be fitted without threading screwed closure 34. A camming member 36 extends from surface 38 of body 28 and grooves 40 accept guide 42 of the second component 4. A slot 4 in body 28 receives a shutter actuator 43 of the second component as will be described.

The second component 4 has small contact pins 44 and 46 forming a second pair of electrical contact means extended in the Y axis from surface 48 fit into sockets 16 and 18 when the shutter is open. Pins 44 and 46 are connected by conductors 50 to the lamp contacts 52 mostly obscured in the drawing. Extending from upwardly facing surface 54 is the actuator 43 which is biased downwardly and towards lamp base 56 of lamp 57 by compression spring 58. Interlock member 60 extends from a hole 2 in surface 48 and is biased upwardly by compression spring 64. Conventional bayonet fitting J slots 66 are provided in exteriorly threaded lamp holder portion 68 forming a holding means of body 70.

In order to fit a lamp bulb, the components 2 and 4 must be separated. The lamp 57 is inserted into the lampholder portion 68 of body 70 with the lamp's bayonet pins 72 home in the J slots. This causes actuator 43 to rise. The components are then fitted together, guides 42 fitting in grooves 40. As head 74 of actuator 43 meets angled cam surface 21 of shutter 20, the shutter rises and aligns shutter holes 24 and 26 with contact sockets 16 and 18.

This allows pins 44 and 46 to be inserted in sockets 16 and 18. At the same time member 36 enters hole 62 to cause interlock 60 to move downwardly to block bayonet pin 72 into J slot 66. This prevents lamp 57 from being removed from holder body 70 when components 2 and 4 are connected.

It can be seen that component 4 cannot be slid in component 2 without a lamp bulb being present so that potentially live parts of the lamp holder cannot be touched.

So that the lamp holder can be packaged or installed as one piece without a bulb being present, a lamp dummy 80 having a base portion 82 similar in size to a lamp cap bayonet pins 84 and fitting portion 86 is provided. This dummy is made of insulative plastics material and when inserted into the lampholder isolates the lamp contacts.

It will be appreciated that plugging in a lamp into the lampholder described is easier as compared to conventional holder if the holder depends from the ceiling because the twisting action between holder and lamp can be carried out with the person involved standing on the ground.

Claims

C L A I M S:

1. A lampholder comprising a first component comprising supply terminals electrically connected to a first pair of contact means and a second component comprising a lamp holding means having a pair of lamp contacts electrically connected to a second pair of contact means which can make contact with the first pair, the first component being separable from the second component so as to electrically separate the contact between the first and second pair of contact means.

2. A lampholder as claimed in claim 1 wherein the components are arranged to join together in a direction substantially at right angles to the bulb axis.

3. A lampholder as claimed in claim 1 or 2 wherein interlock means are provided to block at least one J slot of the lamp holding means of the second component as adapted for a bayonet fitting when the first and second components are joined together.

4. A lampholder as claimed in claim 3 wherein the interlock means comprises a protrusion from the first component which acts on an interlock member in the second component biased away from the lampholder of the second component.

5. A lampholder as claimed in any one of claims 1 to 4 wherein shutter means are provided to cover exterior access to the first pair of contact means.

6. A lampholder as claimed in claim 5 wherein an actuator member is mounted in the second component biased toward the lamp holding means of the second component and movable by insertion of a lamp into the second component away from the lamp to a position in which on initial junction of the first and second component, the shutter is opened so that the second pair of contact means can make electrical contact with the first pair of contact means.

7. A lampholder as claimed in claim 5 or 6 wherein the shutter means is biased to close.

8 A lampholder as claimed in any one of claims 1 to 7 wherein the first and second pair of contact means comprise a pin and socket arrangement.

9. A lampholder as claimed in any one of claims 1 to 8 wherein guide means are provided as between the first and second components to guide one into the other.

10. A lampholder substantially as described with reference to the accompanying drawings.