GB2040608A - Quickly mounted lamp-holders - Google Patents

Abstract

A lamp-holder comprises a casing 2 which is releasably coupled in a screw or bayonet-like manner to a hood 1, and which carries a member 3 supporting lamp contacts 28, 29. The terminal end of each contact 28, 29 has a resilient leaf 31 which clamps the end of an electric lead 26 against a rigid sidewall 30 of the contact. <IMAGE>

Description

SPECIFICATION Quickly mounted lamp-holder This invention relates to a quickly mounted lamp-holder for household and motor car use, which has the basic advantage of being capable of a quick installation in the seat intended therefor.

The conventional lamp-holders of the trade are as is well known, constructed in three component parts, two of which are external (casing and hood) screwably fastened to one another and intended, respectively, for receiving the lamp and for being secured to an appropriate supporting member for the lampholder, and an internal component part (contact holding socket) equipped with screw clamps for electrically and mechanically connecting the electric leads (passed through a specially provided bore thorough the hood).

To install a lamp-holder of the kind referred to above, it is necessary to separate the two external component parts from one another by unscrewing them (and thus also the internal contact-bearing socket must be unscrewed), to have the electric leads passed through the bored hood, to fasten the latter to is supporting member, to connect and set the leads relative to the electric contacts of the lamp-holder by means of the screw clamps of the contact-bearing socket, to insert the socket again in the hood and finally to screw the casing again to reassemble the lamp-holding unit.

As can be seen, a sequence of operations is required and these, in summation and especially when performed in uneasy postures, require undesirably long times. In addition, it is also necessary to have a screw-driver available for screwably affixing the electric lead ends.

An object of the present invention is to provide a lamp-holder having a simplified structural arrangement, which requires a short timé for installation and dispenses with the use of screwdrivers and other like utensils.

According to the invention, this object is achieved by means of a lamp-holder which is characterized in that it comprises a hood having a through-bore for passing the electric leads therethrough and means for fastening the hood to a lamp-holder supporting member and a casing for receiving the lamp, the latter being releasably connected to the hood and carrying, hooked up thereto, a contact-bearing socket having clamping means for securing the electric lead ends, said clamping means comprising at least one rigid wall and a resiliently flexible leaf adapted to urge and clamp a respective cable ends against said rigid wall.

It is apparent that, since the contact-bearing socket is hooked up to the casing, so as virtually to form a unit therewith, the lamp-holder according to the invention is virtually composed by two pieces only (viz.: hood and casing with contactbearing socket) which can be easily separated and reassembled (for example of the screw or the bayonet type). In addition, it deserves attention to have in use resilient leaf clamps rather than screw clamps since no screw driver is required and the entire setting operation of the cable ends becomes, in its turn, much more rapid and convenient than before. The overall result is that the lampholder can be very quickly installed.

Once the basic concepts set forth above are borne in mind, the lamp-holder according to the invention can take slightly different shapes and forms consistently with the mode of use. Thus the hood can be fitted with fastening means of various kinds, which are adapted, as the case may be, for the fastening to a chandelier rod, to a supporting member for table lamp or to a supporting member for motor car headlights, while the casing can be adapted to receive a screw-lamp (Edison type) or a bayonet lamp and can have both the conventional elongate shape and the parabolic outline of a motor car lamp and the coupling between the casing and the hood can be either of the screw qr the bayonet type as aforesaid.

Thus, it is only by way of nonlimiting example that the accompanying drawings show, and the ensuing description illustrates in detail a type of lamp-holder for Edison lamps, adapted for being secured to~a chandelier rod and with a bayonet coupling between the hood and the casing.

In the drawings: Figure 1 shows the lamp-holder in crosssectional view taken along the line I-I of Figure 2.

Figure 2 shows the lamp-holder in crosssectional view taken along the line Il-Il of Figure 1.

Figure 3 shows the lamp-holder in crosssectional view taken along the line Ill-Ill of Figure 2.

Figure 4 shows the lamp-holder in side elevational view as viewed in the direction of the arrow F of Figure 3, a few component parts being shown in cross-section.

Figure 5 shows the lamp-holder in cross sectional.view taken along the line V-V of Figure 1.

Figure 6 shows a detail of the lamp-holder in cross-sectional view taken along the line VI--VI of Figure 1, and Figure 7 shows the lamp-holder in crosssectional view taken transversally along the line VIl-VIl of Figure 1.

The lamp-holder as depicted in the drawings basically comprises a hood 1 and a casing 2 carrying hooked thereto a contact-bearing socket 3.

As can be seen in Figures 1, 2 and 4, the hood 1 has substantially the form of a cylinder completely open at either end and partially closed at the other end by a nut 4: the latter has a tapped hole 5 which is adapted to receive for screwing the threaded bottom end of a chandelier rod, 6.

For securing the latter, a special self-locking washer 7, of conventional type per se, is provided, which is secured to the nut 4 and has two diametrically opposite arcuate sectors, 8, projecting inward and capable of being bent to take a frustoconical shape so as to withstand unscrewing of the lamp-holder from the rod 6 as the last threads thereof become engaged. Said sectors 8 are alternate with further arcuate sectors 9 which project downward in the figure of an L and also inward and are end of stroke abutments for the rod 6 (Figure 2).

If so desired, the self-locking washer 7 can be dispensed with and a stop dowel can be used which extends at an angle in the body of the nut 4 to engage the wall of the rod 6.

The casing 2 is releasably coupled to the hood 1 by means of a bayonet coupling embodied by two jutting ears 10 of the casing 2 and as many shaped slots 11 of the hood 1 (Figures 2, 3 and 4) and has, in its turn, the shape of a cylinder open at both ends, with a frustoconical flare in the bottom section.

The flared bottom section of the casing has internally four arcuate screw-threaded sectors 1,2 (Figures 1,2 and 7) through which a screw-lamp 1 3 can screwably be fastened (Figure 1). The top cylindrical section of the casing has, conversely, two rectangular diametrically opposite windows 14 (Figures 2, 3 and 4) in which there are snappingly inserted, by exploiting the deformability of the casing as tendered by vertical slits 1 5 (Figures 1,2 and 4), as many diametrically opposite teeth 16 which jut laterally of the planar body 1 7 of the socket 3 (Figures 2, 3 and 4).Each window 14 is arranged between a respective couple of widened openings 18, which are the extensions of respective slits 1 5, in each of which is housed a respective one of four centering teeth 19, which also laterally project from the socket body 3 (Figures 3 and 4).

In addition to the planar body 1 7 and the projecting teeth 16 and 19, the contact-bearing socket 3 provides two cylindrical seats 20, connected by a diametrical rib 21 (Figures 2 and '3), each of which houses a spring 22 biasing an overlying dish 23 to maintain the bayonet engagement between the casing 2 and the hood 1. Each spring as 22 in centered by a respective couple of pins 24, 35 opposite to each other and projecting the one from the planar body 17 of the contact-bearing socket, and the other from the dish 23.

Substantially orthogonally relative to the cylindrical seats 20 are arranged above the planar body 17 of the socket 3 two clamps 25 (Figures 1 and 3) separated from one another by the rib 21, which are provided for setting and electrically connecting respective ends of electric leads 2-6 (passed through the rod 6 and through diametrical slits of the dish 23, referenced 27, in Figure 5) to respective electric contacts 28 and 29 integral with the clamps 25 and emerging from beneath the planar body 1 7 for contacting the respective eiectrodes of the lamp 13.

As shown in Figures 1,3 and 6, each clamp 25 comprises, substantially, a metal sidewall 30 fixed in space and a resilient leaf 31, which clamps the barred ends of the respective leads 26 against the fixed wall 30, so that the use of screws or like fastening means is avoided and the use of any utensils likewise.

Each assembly composed by a clamp and an electric contact is inserted in a respective slit 32 of the planar body 17 of the socket 3 and is retained therein by the action of bent tabs 33 and 34.

From the foregoing description of the structure of the lamp-holder according to the invention as shown in the drawings, it is apparent that its installation can take place extremely simply and quickly. Once the hood 1 has been secured to the rod 6, it is sufficient, in fact, to have the electric leads, previously spread away from one another, through the diametrical slits 2i of the dish 23, pinched between the resilient leaves 31 and the fixed walls 30 of the respective clamps 25, whereafter the bayonet coupling can take place between the casing 2 and the hood 1. The installation is thus completed very quickly and without any help of tools.

It is to be noted that, by the effect of the selflocking washer 7, the lamp-holder is locked relative to the supporting rod 6, so that an unscrewing of the lamp-holder concurrently with the unscrewing of the lamp is efficiently prevented.

Claims (5)

1. A rapid installation lamp-holder for household and motor-car use, characterized in that it comprises a hood fitted with a bore for passing electric leads therethrough and means for fastening the hood to a supporting member for the lamp-holder and a casing for receiving the lamp, which is releasably secured to said hood and carries hooked up a contact bearing socket having clamps for clamping, electric lead ends, said clamping means comprising at least a rigid sidewall and a resiliently pliable leaf adapted to urge and clamp a respective cable end against said rigid sidewall.

2. A lamp-holder according to claim 1, characterized in that it provides a bayonet coupling for releasably connecting the hood with the casing.

3. A lamp-holder according to claim 2, characterized in that it provides a dish superposed to said contact-bearing socket on the side of the hood and fitted with slits for allowing the pass of the electric leads, resilient means being inserted between the socket and the dish to urge through the socket the retention of the bayonet coupling between the hood and the-casing.

4. A lamp-holder according to claim 1, characterized in that said hood fastening means comprise a nut through which a tapped bore is formed in which there can be screwed the supporting rod of a lighting appliance, the internal end of said tapped bore being associated with a washer having two arcuate inward projecting sectors to provide by deformation in the form of a frustum of cone a locking engagement with the last threads of the supporting rod and two additional sectors which projects inward in an axially shifted position to act as end-of-stroke abutments relative to said supporting rod.

5. A rapid installation lamp-holder for household and motor car use substantially as hereinbefore described with reference to and as shown in the accompanying drawings.