GB2214041A

GB2214041A - Fitting for an incandescent lamp

Info

Publication number: GB2214041A
Application number: GB8830394A
Authority: GB
Inventors: Dieter Henrici; Alfred Bothe
Original assignee: Broekelmann Jaeger and Busse GmbH and Co
Current assignee: BJB GmbH and Co KG
Priority date: 1988-01-20
Filing date: 1988-12-30
Publication date: 1989-08-31
Anticipated expiration: 2008-12-30
Also published as: DE3801480C1; GB8830394D0; GB2214041B

Description

1 2214041 - 1 FITTING FOR AN INCANDESCENT LAMP

DESCRIPTION

This invention relates to a fitting for an incandescent lamp.

It is known to provide electric lamp fittings with screwless connecting terminals for electrical supply leads, wherein the bared ends of the leads are push fitted into insertion openings in an insulating body member to make electrical connection with barb-like clamping members that make electrical connection with the leads.

c However, particularly for the sector of the appliances industry producing what are known as white goods, there is a desire to provide lamp fittings which are suitable for connecting to leads provided with plug sockets or the like. Consequently, an object of the invention is to provide a fitting for an incandescent lamp which makes this possible in a simpler manner.

According to the invention there is provided a fitting for an incandescent lamp, comprising a body of -electrically insulating material and screwless connecting terminals for supply leads inserted therein, each of the connecting terminals comprising a lead insertion opening in the body and electrical clamping means within the body for clamping and making electrical contact with a supply lead inserted through the opening, and an elongate connecting plug including a coupling section for insertion through the insertion opening to form an electrical connection with the clamping means, a connecting section to be upstanding from the body to receive electrical power, and a transversely offset portion between said connecting portion and said offset portion, the plug being so arranged that upon insertion thereof into the lead insertion opening said offset portion engages an inner surface of the insertion opening and the plug is latched against an edge of the opening to inhibit removal thereof.

Thus according to the invention the connecting plug is held in place not only by the conventional action of the clamping means but also by the latching prdouced by -7 3 - the disposition of the offset portion. This has the advantage that known connecting terminal do not themselves need to be modified to receive the connecting plug, and in particular their spring tension does not need to be altered.

1 This means that it is possible subsequently to provide known fittings for incandescent lamps with connecting plugs of this kind without any alteration, the connecting plugs being inserted into the screwless connecting terminals instead of the bared ends of supply leads.

It is in fact generally known to provide an electric connecting terminal with an earthing strap, wherein this is inserted into the terminal opening otherwise intended for the bared ends of supply leads. Of course, in that case circumstances are such that the springs of the very firmly held connecting terminals are very strong and can therefore exert particularly great restoring forces. Their terminals are also adapted to receive thicker and less flexible supply leads. Circumstances of this kind are not found in the case of fittings for incandescent lamps, so that in order to achieve the objective in the known manner, new and more expensive connecting terminals with clamping arms would have to be designed. The invention eliminates this necessity and is also characterised by the advantage that the connecting plugs can be inserted into the screwless connecting terminals with little force being expended. On the other hand, it is more difficult to apply the force required for correct mounting on the earthing strap of the known connecting terminals.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a longitudinal section of a fitting for an incandescent lamp, having two connecting plugs; Figure 2 is a cross section along the line of intersection II-II of Figure 1; Figure 3 is a side view of a connecting plug; and Figure 4 is a front view of the connecting plug shown in Figure 3.

A fitting for an incandescent lamp 10 comprises an insulating material body 11 with an internal screw thread 12 to receive an incandescent lamp, and two contacts 13 and 14 for the supply current, the contacts being combined with screwless connecting terminals 15 and 16.

is In this embodiment, each screwless connecting terminal 15, 16 comprises a resilient and/or resiliently mounted clamping arm 17, 18 and a contact arm 19, 20, the contact arm 19 acting upon the middle contact and the contact arm 20 acting upon the side contact of incandescent lamp when fitted in the screw thread 12.

Furthermore, in this embodiment, the two screwless connecting terminals 15, 16 are each designed in two parts, although this is of no consequence to the invention. In order to achieve optimum contact, free ends 15a, 16a of each of the terminals are disposed resiliently towards a respective contact section 15b, l6b essentially rigidly mounted in the insulating material body 11.

an C As described so far, the fitting for an incandescent lamp 10 corresponds to the state of the art. In order to insert the bared ends of leads, which are not shown, into the connecting terminals 15, 16 in the usual manner known hitherto, the rearward end of the insulating material body 11 has electrical lead insertion openings 21, these, arranged in pairs for each as is also usual, being of the two screwless connecting terminals 15, 16 (see Figure 2). Also, it is to be noted that the lead insertion openings 21 are provided on their underside with an outwardly stepped edge 21a.

In accordance with the invention it is possible to equip the fitting 10 to receive supply leads provided with cable lug or similar plug connections, without any design alterations to the fitting itself. To this end, two essentially flat rectangular connecting plugs 22 are provided, the design of which is shown in detail in Figures 3 and 4. Each one-piece connecting plug consists of a free connecting section 23 for a plug socket, cable lug, or the like, and a coupling section 24 for making connection with a connecting terminals 15 or 16. Each coupling section 24 is a double section or 1 1 - 7 is divided in to two or more arms according to the number lead insertion openings 21. In this embodiment, the sheet metal of the connecting plug is separated into two narrow coupling sections 24a and 24b by punching out a slit 28.

The connecting section 23 and the coupling section 24 are separated by an essentially C- or U-shaped offset 25. This offset 25 with an offset depth T (Figure 3) forms an offset base 26 and an offset peak 27. The width T is greater than the corresponding cross sectional width of the opening 21 shown in Figure 1.

As can be seen in Figure 1, the connecting plug 22 inserted into a connecting terminal 15 or 16, is supported by means of the offset peak 27 lying against the inner face of a lead insertion opening 21. Also on the opposite side of the opening 21, the offset base 26 latches underneath the underside edge 21a of the opening 21 and is pressed against this edge due to the retaining force of the clamping arm 17, 18 of the connecting terminal 5, 16. Thus, the connecting plug 22 is firmly held not only by the clamping arm 17 or 18 due to the barb-like effect thereof, but also simply by 8 - the pressure appliedby the terminal edges 15a, 16a.

This pressure maintains the engagement of the offset base 26 beneath the underside of the underside edge of the lead insertion opening 21, for which relatively little force is required as the connecting plug 22 is held in place on the opposite inner face of the lead insertion opening by means of the offset peak 27.

Therefore, there is firm 2-point support of each connecting plug 22. In addition of course, the clamping forces of the connecting clamping arm 17 also act thereon, but these do not need to be particularly great.

An arrangement of this kind is therefore also particularly advantageous because a conventional fitting for an incandescent lamp 10 can be converted simply by inserting two identical connecting plugs 22, which themselves are simple punched parts.

t 1.

Claims

1. A fitting for an incandescent lamp, comprising a body of electrically insulating material and screwless connecting terminals for supply leads inserted therein, each of the connecting terminals comprising a lead insertion opening in the body and electrical clamping means within the body for clamping and making electrical contact with a supply lead inserted through the opening, and an elongate connecting plug including a coupling section for insertion through the insertion opening to form an electrical connection with the clamping means, a connecting section to be upstanding from the body to receive electrical power, and a transversely offset portion between said connecting portion and said offset portion, the plug being so arranged that upon insertion thereof into the lead insertion opening said offset portion engages an inner surface of the insertion opening and the plug is latched against an edge of the opening to inhibit removal thereof.

2. A fitting according to claim 1 wherein the offset portion extends transversely of said coupling portion by an amount greater than the transverse sectional width of the insertion opening whereby said offset portion is latched against an inner edge of said invention opening in the body.

3. A fitting according to claim 1 or 2 wherein said offset portion is Cshaped or U-shaped in section.

4. A fitting according to any preceding claim wherein the connecting portion and the coupling portion have coplanar major surfaces laterally offset from one another.

5. A fitting according to any preceding claim wherein said plug has been formed by stamping from metal sheet.

6. A fitting according to any preceding claim including first and second current supply contacts for the lamp within the body, each of the contacts having associated -therewith a respective plurality of said lead insertion openings, said plug including a 11 - 11 plurality of arms for insertion into the openings associated with a respective one of the supply contacts.

7. A fitting for an incandescent lamp, substantially as hereinbefore described with reference to the accompanying drawings.

8. A connecting plug substantially as hereinbefore described with reference to Figures 3 and 4 of the accompanying drawings.

9. Fitting for an incandescent lamp comprising an insulating material body and terminals screwless connecting for supply leads inserted therein, each connecting terminal having at least one barb-like clamping arm inclined essentially in the direction of insertion of the leads, and a lead insertion opening in the insulating material body being associated with each clamping arm, characterised in that a connecting plug is provided which can be inserted into the connecting terminal by means of a guiding coupling section of the free connecting section for a plug socket, cable lug, or like, the connecting section and being subdivide by 1 means of an essentially C- or U-shaped offset which engages behind the edge of the insertion opening due to the force of the clamping arm.

1 Published 1989 atThePatentOfflce, State HouSe.68171 RW2.HoIborn. londonWClR4TP. Further copies maybe obtained from The Patent Office OVD. 11rinted by Multiplex techriquea Itd, StMaX7 Cray, Rent. Con. 1/87 i i