GB2165711A - Lamp holder - Google Patents

Abstract

A lamp holder intended primarily for use in automobiles comprises a tubular body portion 10 of insulating material for receiving the cap of a bulb (not shown), and shaped to provide a lower region accommodating tab ends 13, 14 of terminal strips 11, 12 which extend into respective recesses 17, 24 in an upper region of the body 10 and provide respectively an inclined contact portion 16 and a transverse contact portion 23. The terminal strips 11, 12 have pressed-put retainer tabs 15 which serve, after insertion of the strips 11, 12 into position, to prevent withdrawal thereof by co-operation with respective shoulders 36, 25. The lower region of the body 10 has fitted thereto a cap-like shield 27 having a tubular entry 29 for leads to the tab ends 13, 14 and optional ribs 28. <IMAGE>

Description

SPECIFICATION Lamp holder This invention relates to an improved lamp holder, the constructional form and design features of which fulfill the function for which it has been specifically devised with maximum reliability and effectiveness.

The lamp holder of the present invention is specifically (but not exclusively) intended for use in the motor industry, for instance in automobiles. This means that the lamp holder has to be very reliable and safe.

Basically all the prior art lamp holders are formed to include contacts which, in turn, are connected by conventional connection systems or leads to further terminals, the latter in most cases being quick-fit safety connectors which are finally connected to an electrical harness.

An object of the invention is to provide a lamp holder of substantially simplified construction and in which provision is made for very efficient connection of the electrical leads to the contacts for engaging a bulb in the holder, whilst at the same time dispensing with the need for all intermediate terminals such as are necessary with the conventional lamp holders. It will be evident that this avoids the cost of the eliminated terminals, as well as the labour required for their connection; moreover the possibility of faulty contacts is minimised as a result of the smaller number of members needing to be connected together in the lamp holder of the invention.

With the foregoing objects in view, the present invention provides a lamp holder comprising a body portion, of insulating material, the interior of which is divided into two areas or regions in one of which are located ends of terminal strips adapted for connection to respective leads of an electrical supply cable each by a pair of deformable tabs, one of the terminal strips having, beyond its tabs, a substantially rectangular section in a portion of which, remote from the tabs, is a wedgeshaped pressed-out portion, the rectangular portion continuing through a curved connecting portion and terminating in a free end portion forming a respective contact which diverges from the rectangular section, said terminal strip having been inserted in a respective recess or cavity in the body portion, the arrangement being such that upon the wedgeshaped pressed-out portion moving beyond a shoulder on the body portion, said shoulder prevents the terminal strip from being withdrawn from the recess or cavity therefor.

Basically the lamp holder of the invention comprises a body portion having two distinctly defined areas or regions.

The tab ends or free ends of the terminal strips project in the lower region of the body and are located in the side wall of the body portion which is preferably substantially eiliptical when viewed from below. The said free ends of the terminal strips may be of conventional configuration and provided with two pairs of tabs which, when mechanically clinched, grip respectively a bare portion of a respective wire and its insulation.

The terminal strips in the lamp holder of the invention are preferably accommodated in diametrically opposed slots in the upper part of the body portion. One of the two terminal strips is substantially rectangularly shaped, when seen in elevation, from the region wherein the tabs for the corresponding electric lead connection are formed and has, in the wall thereof, a wedge-shaped pressed-out portion followed by a straight portion which extends through a curved portion, leaving the free end of the terminal diverging from said region. This diverging portion then serves as one of the two contacts of the lamp holder.

It is obvious that, with such a shape, when the terminal strip is in place in the body portion, the contact portion thereof is perfectly placed for performing its contact function as such. Also reverse movement or withdrawing movement of the terminal strip is prevented, since the lamp holder body portion has a shoulder engaged by the pressed-out portion.

The other terminal strip is conveniently of a shape initially substantially similar to the one described above, but with the feature that following the curved portion it is folded over in parallel relation to the portion in which its wedge-shaped pressed-out portion has been formed. The terminal strip then extends through a further curved portion into a perpendicularly extending arm connected to an inclined portion which is connected through a final curved portion to a further arm extending perpendicularly to the portion in which the wedge-shaped pressed-out portion has been formed, the upper free end of this terminal strip stopping short of said portion and forming the respective contact.

Obviously the latter terminal strip, when inserted in its respective recess in the body, is appropriately positioned and retained, the body being provided with a corresponding shoulder engaged by the edge of the respective wedge-shaped pressed-out portion, whereby the free end of this terminal strip is located in a position perpendicular to the axis of the body portion and forms the second contact of the lamp holder.

It will thus be understood that in use, when a single-pole bulb is inserted into the holder, the usual base contact of the bulb engages the end of the last-described contact portion whereas the lateral contact area of the cap of the bulb engages with the contact portion of the first-described terminal strip, the free end of which extends inclined to the side face of the body portion, forming a tongue.

Obviously since there are only two parts which are each in contact with the bulb, and the respective lead, there is virtually no possibility of faulty contact and consequent breakdown in the electrical supply to the bulb, which is protected and housed in the body portion and may be retained by conventional holding means such as a bayonet arrangement.

Furthermore, in the region where each of the two terminal strips is connected to its respective electrical supply cable there may be a protective shield in the central lower portion whereof there is a hollow cylindrical portion or tubular cable entry the inner diameter of which corresponds substantially to the outer diameter of the cable whose leads will be connected to the tab ends of the terminal strips the other or free ends of which form the contacts. Since such shield may be of very resilient material, it can ensure an effective shield against entry of foreign matter and/or moisture on being fitted to the outer surface of the body portion protecting the contacts. The walls of this shield may be provided with a plurality of vertical ribs, e.g. along the generating lines thereof, to contribute to the tightness of the lamp holder.

Further details and features of the invention will be described in the following with reference to the accompanying drawings and in which preferred details are schematically illustrated. These details are given by way of example, with reference to one possible embodiment, but the invention is not limited to these details and the following description should, accordingly, be considered to be illustrative and not limitative of the scope of the invention.

In the drawings: Figure 1 is a schematic exploded view, partly in section, showing the various parts of the preferred lamp holder of the invention; Figure 2 is schematic side view of one of two terminal strips the free end of which strip forms one of the two contacts in the lamp holder of Fig. 1; Figure 3 is a further schematic side view of the other terminal strip the free end of which provides the other contact of the lamp holder of Fig. 1, Figs. 2 and 3 having been arranged adjacent their corresponding representations in Fig. 1; Figure 4 is an elevation view, partly in section, illustrating the lamp holder of Fig. 1 in the assembled condition; Figure 5 is a plan view corresponding to Fig. 4; and Figure 6 is an underneath view of the lamp holder, but with the contact shield thereof having been removed.

It will be seen from the drawings that the illustrated preferred embodiment of the lamp holder of the invention comprises a body portion 10 which is divided into two regions, namely an upper smaller diameter region and a lower larger diameter region. Lower tab ends of terminal strips 11 and 12 are located in the lower regions thereof, and these in turn act as terminals, since through such ends contacts of the lamp holder will receive electrical current on being connected to a cable for supplying the electricity to a bulb (not shown) fitted into the holder, respective leads 40, 42 of said cable being connected to the respective strips 11, 12 each with the aid of two pairs of deformable tabs 13 and 14 which, on being clinched, will grip respectively the conductor of the lead 40 or 42 and the insulation thereof.

Beyond its tabs 13 and 14 the terminal strip 11 comprises a substantially rectangular section 44 having formed therein a wedgeshaped pressed-out portion 15 (see Fig. 2).

The upper end of the rectangular terminal strip 11 extends to curved connecting portion to which there is joined an arm portion 16 which is an inclined contact, which portion 16 diverges outwardly from the section 44 of the strip 11. With this configuration, the terminal strip 11 may be inserted in its respective recess or cavity 17 in the body portion 10 (see Fig. 4), and the arrangement is such that when the free edge of the wedge-shaped pressed-out portion 15 has moved beyond shoulder 36 in the cavity 17, the portion 15 prevents the terminal strip 11 from moving backwards and being withdrawn from its location in the body portion, and holds the strip 11 firmly in place.

The terminal strip 12 has a shape which, initially, is substantially identical to that of the terminal strip 11. Thus, beyond deformable tabs 13 and 14 there is a rectangular section 18 having formed therein a wedge-shaped pressed-out portion 19, the rectangular section 18 being joined, through a curved connecting portion, to a further overlying rectangular portion 20 extending in parallel relation to the portion 18. The overlying portion 20 joins, through a curve, with a perpendicularly extending arm portion 21, connecting in turn with an inclined portion 22. This inclined portion 22 is connected by way of a wide curve to a further transverse arm portion 23 which forms the second contact of the lamp holder and extends substantially perpendicular to the rectangular section 18.

The terminal strip 12 being of this shape, it can be inserted into its respective recess or cavity 24 formed in the body portion 10 for receiving it. During this operation once the pressed-out portion 19 has passed beyond shoulder 25, the movement of the terminal strip 12 may not be reversed so that the strip 12 cannot be withdrawn. The portions or ton gues 15, 19 accordingly locate the terminal strips 11, 12 with their portions 16, 23 re spectively located so as to be accurately posi tioned to form the contacts whereby electrical connection is established when a bulb is in serted in the lamp holder.The terminal strips 11 and 12 are connected to the leads of the cable which extends into the opposite end of the lamp holder body portion 10 wherein the tabs 13, 14 are disposed, which region is also protected by a shield 27 of extremely resilient insulating material provided on the outer surface thereof with a plurality of ribs 28 which reinforce the tightness of the lamp holder, the shield 27 including a slightly tapering end portion or tubular entry 29 through which the electric cable, to be connected to the terminal strips 11 and 12 by means of the deformable tabs 13 and 14, is inserted.

The illustrated lamp holder is also provided with a sealing gasket 30 which locates against a shoulder provided therefor on the body portion 10.

It will be appreciated that with the lamp holder of the invention, since the electrical connections are made directly to the respective contacts, perfect reliable and correct operation is ensured. The risk of circuit faults or breaks is avoided, since the conventional terminals connecting the leads of the cable to the contacts have been eliminated, the illustrated novel terminal strips making the latter unnecessary.

It will be understood from the drawings and the description thereof that the invention provides a simple and effective construction which is easy to manufacture and without any doubt provides an advantageous industrial advance.

Variations and modifications may, of course, be made to the details of the above-described embodiment without departing from the scope of the invention as defined by the following

Claims (4)

claims: CLAIMS

1. A lamp holder characterised in that it comprises a body portion, of insulating material, the interior of which is divided into two areas or regions in one of which are located ends of terminal strips adapted for connection to respective leads of an electrical supply cable each by a pair of deformable tabs, one of the terminal strips having, beyond its tabs, a substantially rectangular section in a portion of which, remote from the tabs, is a wedgeshaped pressed-out portion, the rectangular portion continuing through a curved connecting portion and terminating in a free end portion forming a respective contact which diverges from the rectangular section, said terminal strip having been inserted in a respective recess or cavity in the body portion, the arrangement being such that upon the wedgeshaped pressed-out portion moving beyond a shoulder on the body portion, said shoulder prevents the terminal strip from being withdrawn from the recess or cavity therefor.

2. A lamp holder as claimed in claim 1, characterised in that the other terminal strip is of a shape which is, initially, substantially identical to that of the said one of the terminal strips, having a respective rectangular section wherein is a wedge-shaped pressed-out portion, said rectangular section being joined to a further portion extending in parallel thereto, followed by an arm portion extending perpendicularly to the said further portion and thence in an inclined portion connecting by a curved portion to a respective contact portion which is substantially perpendicular to the rectangular section, said terminal strip having been inserted in a respective recess or cavity in the body portion until the edge of the respective pressed-out portion has moved beyond a respective shoulder so that the terminal strip cannot be withdrawn in the direction opposite to that in which it was inserted.

3. A lamp holder as claimed in claim 1 or 2, characterised in that the contacts for engagement with a bulb are protectively accommodated in a respective one of the two areas or regions of the body portion, the other area or region, accommodating the terminal strip ends for connection to a supply cable being, in turn, masked by a protective shield or cap of resilient insulating material having, on its exterior, a plurality of reinforcements, the shield or cap having a tubular entry for a cable whose leads are to be connected to the terminal strips by means of the corresponding deformable tabs.

4. A lamp holder substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.