GB2331405A

GB2331405A - Light bulb socket which can hold bayonet or Edison screw bulbs

Info

Publication number: GB2331405A
Application number: GB9714653A
Authority: GB
Inventors: James George Arthur Croll
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-07-12
Filing date: 1997-07-12
Publication date: 1999-05-19
Anticipated expiration: 2017-07-12
Also published as: GB2331405B; GB9714653D0

Abstract

The light bulb socket can hold either a bayonet cap (bc) light bulb or an Edison screw (es) light bulb. A sliding component 2 is movable within a fixed component 1. An ES bulb can screw into the sliding component and make contact with the terminal 9 (see figure 3). A BC bulb pushes the sliding component down and makes contact with the terminals 18 (see figure 4).

Description

1 LIGHT BULB SOCKET This invention relates to a new form of universal

light bulb socket.

2331405 For domestic and light industrial use, generally in the wattage range 20 - 250 W, there are two major classes of light bulb connection in s,..orld-, ..ide use. The two classes of light bulb stem connection used to couple the light bulb to the electrical circuit are: the standard bayonet cap ( designated be) which for use in the 20 - 250 W ran.e has characteristics shown in Figure 1 (a); the standard edison screw designated es) thread stem which over the same wattage range has the form shown in Figure 1(b). Closely. related classes of connector are used for lower wattage range light bulbs. For light bulbs in the 12 - 60 W range the two equivalent classes are the small bayonet cap ( sbc) and small edison screw ses) system. At even lower wattage, often operating at lower voltage, the two classes of bulb are the mini-bayonet cap ( mbc) and the mini-edison screw (mes). For all these classes of light bulb connection system and for the different sizes associated with the different wattage ranges there are regional variants, but the forms are usually compatible and mill be covered by the solution ogered by the present invention. Although details of the invention are provided for the bulbs used in the 20 - 250 W range, and shown in Figure 1, the invention concept covers those used in other wattage ranges and the size variants adopted in regions other than Europe. This invention relates to all bulbs of the normal bayonet and scren. type.

An almost universal source of frustration to the light bulb user, is the Uelihood that when a particular bulb blows the only available replacement bulbs will have a class of connector different from the one that has blown. To avoid such inconvenience the average user is forced to carry stocks of spares covering both types of connection class. This means that effectively twice as many spare bulbs are needed in the spares stock as would be the case had all light fittings been of just one type. It is unlikely that agreementmill be reached to eliminate one of the current standard bulb classes. It is also unlikely. that the use of adaptors mill provide an economically attractive or even practical solution. The present invention provides a means of overcoming the current source of user inefficiency and constant source of operational inconvenience by introduciing a new form of socket that, ii.Me retaining the simplicity of the current socket systems, allows both classes of light bulb stem to be fitted. This invention is for a new type of universal light bulb socket that is compatible mith the use of either the bayonet or the screm. thread light bulb.

The universal light bulb socket allows either the be or the es light bulb to be used interchangeably. It has three major elements:

A fixed 'core component(s), labelled as (1) on Figure 2, provides the connections with the external electrical wiring and has the means of attachment for the safety covers. This fixed core component(s) t> - also provides: the mechanical attachments for the be bulb; the rotational constraint to the slidina component; and, contains the guides for the spring loaded sliding pins that provide the electrical contacts for the sliding component.

A 'sliding component', indicated as (2) on Figure 2, provides the rotationally fixed connection for the es light bulb. It also has the electrical contacts for the es light bulb and the sliding pins which provide the link to the external iviring connections.

7 An outer skirt component (3) prosides a safety covering to the base of the es light bulbs, and serves to lock-in the sliding component (2).

0 A base enclosure cover to the electrical connections which can be made compatible.,ith many. types or existing socket.

cl A particular form of the invention is described for the standard be and es light bulbs, %,,.hose connections are summarised in Figures 1(a) and (b). Related inventions, covered by separate patents. provide example solutions for the cases of the sbe and ses bulbs, and the rnbe and mes bulbs.

Figure 1 shows details of the standard be and es bulb stems.

Figure 2 shows sections through an exploded breakdown of the main components.

Figure 3 shows sections through a universal light bulb socket with an es bulb in place.

Figure 4 -. -- shows sections through a universal light bulb socket %iith an be bulb in place.

With reference to Figures 2, the sliding component (2) is rotationally orientated within the fixed component (1) b3. means of two ke-,-%,.-avs (5) cut-cut from the othen-,ise rotationally symmetric casting of component (2). When installed these key'll.kys prevent any. rotational movements but allow free inward and outward sliding movements of component (2) relative to component (1), 1j5r locking over Z> the protruding shoulders (6).-lijch form part of component (1). Rotational locking of component (2) 0 enables the es bulbs to be installed, while the sliding freedom allows the be bulb to be fitted.

A further rotational positioning of the sliding component (2) relative to the fixed core corn nent 0 PO is provided by. the sliding pins (7) used to affect the electrical supply. to the contact points (9) and (10) for the es bulb. These sliding pins (7) pass through guides (11) in the base plate of the fixed component (1). these guides also serve to house the pre-compressing springs (12) that provide the force required to lock-in the be bulb. The be bulb locks into standard bayonet slots (13) provided in the shoulders (6) on the fixed component (1). Rotational alignment of the bayonet bulb pins (22) during insertion is assisted b.,. the vertically aligned guidance slots (14) formed in the slide component (2).

When assembled, as shown in Figures 3 and 4, the inner rim (15) on the outer skirt component (3) is used to provide the locking mechanism to keep the sliding component (2) in place. The outer skirt (3) also provides a barrier (16) to am. accidental contacts b), a user.%ith the live screw thread on the es bulb. As a result of the pre-compressing force provided by the springs (12) on the sliding pins (7), the sliding component (2) is kept compressed against the rim (15) of the locking outer skill (3).

4P 0 An es bulb (17) is fitted, as shown in Figure 3, by simply. scresiing it into the sliding component (2) until it comes into contact iiith the two compliant electrical contact points (9) and (10). Because the shoulder (6) and keyway, (5) prevent relation, and since the upper ledges (t) of the shoulders (6) prevent all but very small sliding movements of the sliding component (2) when the es bulb is installed, it is not possible for the es bulb to come into electrical contact with the two pin terminals (18) used for the be bulb operation. The screw clamps (19) allow flexible wire connections from the sliding pins (7) to the fixed scren clamps (20),,,,hich also serve as the terminals to the incoming electrical wiring. W-hen fitted the es bulb will appear as sho,.,,-n in Figure 3.

3 A he bulb (21) is fitted, as shown in Figure 4, by the conventional downward pushing of the bayonet cap into the sliding component (2), with the bayonet pins (22) providing the correct rotational positioning when located in the slots in both the sliding component (14) and the shoulders of the fixed component (13). When the bayonet cap is pushed into the sliding component (2) the shoulder (23) on the bulbs metal cap come into contact with the top (24) of the sliding component (2), having the effect of pushing it downwards until it is possible to twist the bayonet pins (22) into their locking. cavities (25) ivithin the fixed shoulder (6). The pre-compression provided by the springs (12) on the sliding pins (7),. %ill ensure that the bayonet pins (22) are firmly locked into place. When fitted the be bulb will appear as shown in Figure 4.

4 CLAMS 1. The universal light bulb socket allows either a bayonet cap ( be) or an edison screw ( es) light bulb to be used inter-changeably.

Claims

2. A universal light bulb socket as claimed in Claim 1 has a fixed 'core

component(s)'. providing the connections with the extemal electrical wiring and has the means of attachment for the safety covers. This fixed core component(s) also provides the mechanical attachments for the be bulb, and contains the guides for the spring loaded sliding pins that provide the electrical contacts on the sliding component.

3. A universal light bulb socket as claimed in Claims 1 and 2 has a 'sliding component, with nyo kevivays to constrain its movements to just in and out sliding motion within the fixed core corn nent. PO This proAdes the rotationally fixed connection for the es light bulb. It also has the electrical contacts for the es light bulb and the sliding pins which provide the link to the external wiring connections.

4. A universal light bulb socket as claimed in Claim 1 to 3 wherein the sliding motion within the 0 keyways is provided by means of two fixed shoulders, formed by protrusions within the otherwise circular cavity of the fixed core component.

A universal light bulb socket as claimed in Claim 1 to 4 with a sliding component that is held within the fixed core component by means of an inner rim to an outer skirt component. This inner rim provides a constraint to the upward motion of the sliding component, and allows the springs on the sliding pins to be pre-compressed- 6. A universal light bulb socket as claimed in Claim 1 to 5 with a sliding component that has an internal screw thread to allow attachment of the standard es light bulb. The rotan. motion required to install the es bulb is prevented from causing any rotation of the sliding component by virtue of the locking action of the shoulder and ke%-s,.-av arrangement.

0 1.

7. A universal light bulb socket as claimed in Claim 1 to 6 in which the es bulb when fully screwedin, come into contact with compliant electrical terminals located at the centre and ofFset from the centre of the sliding component.

8. A universal light bulb socket as claimed in Claim 1 to 7 that when the es bulb is screived-in %,,.ill have the sliding motion constrained by. the contact beh.en the lower part of the es thread and the upper]edges of the fixed shoulders within the core component. This prevents accidental contact with the bayonet electrical terminals.

9. A universal light bulb socket as claimed in Claim 1 to 8 in sitich the compliant electrical terminals are connected to two sliding pins, fitted with springs to provide a pre-compression force,.i.hen the sliding component is pushed into the fixed component cavity. On the underside of the fixed 0 component the sliding pins are capped by screw clamps for attaching electrical wires.

t> - 10. A universal light bulb socket as claimed in Clairn 1 to 9 i,..here the locking pins of a standard be bulb are guided into slots provided in the sliding component and ihich are also aligned to slots in the shoulders of the fixed component. The slots terminate in the standard bayonet pin locking cavities which allov.. the bulb to be held in place by the force equilibrant of the pre-compression force developed in the springs associated with the sliding pin tenninals.

11. A universal light bulb socket as claimed in Claim 1 and 10 in which a standard be bulb.%-hen pushed into the sliding component will, as a result of the contact bet-ween the shoulder on the metal bayonet cap and the top rim of the sliding component, cause the sliding component to move into the cylindrical cavity of the fixed core component.

12. A universal light bulb socket as claimed in Claim 11 in which the standard be, both because of the contact at its metal shoulder and because of its contact with the bottom of the screw. thread cavity in the sliding component, will be prevented from coraing into contact with the es electrical terminals within the screw thread cavity. of the slkling component.

13. A universal light bulb socket as claimed in Claim 10 to 12 whereby a be bulb when locked into the bayonet pin locking cavities within the fixed shoulder, be in electrical contact with the two spring loaded contact pin terininals attached to the fixed component.

14. A universal light bulb socket as claimed in Claims 1 to 13, when fitted with either be or an es bulb, will have an outer skirt component that provides safety protection against accidental contact with any. live metal on the screw thread or the bayonet cap on the bulb.

15. A universal light bulb socket as claimed in preceeding claims for which electrical switching to isolate the socket electrically when not in use and/or safety, locking of input electrical wires may be provided in the lower covered zone of the fixed component.

16. A universal light bulb socket as claimed in preceeding claims for which the thread at the bottom of the fixed component would be compatible with the many, standard covers or attachments used to fix lights to roofs, walls, lamps, and other uses.

17. A uni,ersal light bulb socket as claimed in preceeding claims which, in the cent of an es bulb becornin fused into its socket, can easily be dislodged by removal of the outer skirt and slidin. g component.