US2092989A - Electric lamp - Google Patents

Description

Patented Sept. 14,1937

UNITED sArss Application April 25,

1 Claim.

This invention relates to electric lamps and more particularly to lamps of that type which are employed on motor vehicles, as clearance lamps or other warning lamps.

Lamps of this type are usually fastened upon the walls of the vehicle, and heretofore a considerable portion of the wall had to be cut out to receive the body portion of' the lamp.

One of the objects of the present invention is to provide a lamp which may be applied to the side of the wall of a vehicle body without the necessity of cutting. out any portion thereof to receive the body or case of the lamp.

In lamps of this type now on the market, considerable difficulty has been experienced with the electrical connections between the conductor wire and the lamp, and one of the objects of this invention is to simplify and. otherwise improve upon these connections.

In the present day lamps of this type the electric lamp bulb is set at an angle to the major axis of the lamp, with the result that shadows are cast by the pillars which support the filament, thereby interfering with the efficiency of the lamp bulb itself. I

With these and other objects and advantages in view, this invention consists in the several novel features of construction, arrangement and combination of parts, hereinafter fully set forth and claimed.

The invention is clearly illustrated in the drawing accompanying this specification, in which:-

Fig. l is a central, vertical section through an electric lamp embodying a simple form of the present invention showing the same applied to a fragment of the wall of a vehicle body;

Fig. 2 is a front elevation of the lamp;

Fig. 3 is a front elevation thereof with the lens and electric lamp bulb removed therefrom; Fig. 4 is a fragmental, detail, horizontal section, taken on the line 4-- l of Fig. 3; and

Fig. 5 is an enlarged central, longitudinal section, taken through the electrical connection of the lamp, showing certain parts detached from each other.

Referring to said drawing, which is merely illustrative of one embodiment of the invention, the reference character 6 designates a fragment of a wall of a motor vehicle body, such as a truck 50 body or other motor vehicle body, and said wall is shown as composed of outer and inner metal sheets I, 8, between which is a wooden sheathing 9 and thermotic insulating material I ll. Obviously the wall may be of any of the conventional forms used in motor vehicle bodies.

1936, Serial N0. 76,352

The lamp II is. formed of a hollow disc-like case l2, open at its front end and closed at its rear by a fiat wall l3, which is arranged to be placed. contiguous with vthe'outer face of the metal sheet 7 of the vehicle body wall.

Projecting forward from the back wall is the annular wall M of the case which is formed with an annularshoulder [5 to receive a resilient washer It, against which is placed the lens ll, usually of the. concavo-convex type shown. The annularwall I4 is formed with a rim I8 beyond the shoulder it, in which rim is an annular groove !9 that is arranged to receive a resilient split ring 28 which bears against the outer edge portion of the lens and effectively holds it in place against the washer- For convenience in removing the ring 20, one end thereof is formed with a bent up part 2i, under which a nail or other pointed tool may be inserted for the pur- ..pose of prying the ring out of the groove. This. arrangement provides a simple means'whereby the lens maybe readily removed from the case to' obtain access to the interior thereof. &

Projecting back from the rear wall [3 of the case, in co-axial'alignmenttherewith,is a hollow boss 22 which is cast integral with the rear wall. Formed in the internal face of the boss 22 .are oppositely disposed grooves in the form of bayonet slots 23-which extend from'the front face of the wall l3 along the internal' face of the boss, 22 and have reversely bent extremities 2 which are adapted to receive and hold the usual locking pins 25 on the shell 26 of the conventional electric lamp bulb Z'Lsuch as is used in lamps of this type. 35

In the hollow of the boss 22 is contained an electric connection C to which is connected an electric conductor cord, 0, that leads to a suitable source of electric supply, as for instance a storage battery.

The electric connection C comprises a contact member 35 and a sleeve-like'body 28 (see Fig. 5) formed of non-conducting material and having an annular flange 29 upon one end, against which one end of a coiled compression spring 36 engages, the other end of the spring being arranged to seat upon an annular shoulder 3| formed upon the internal face of the boss 22.

Contained in the hollow of the sleeve-like body 28 and seated against one end thereof, is the socket portion 32 of the electric contact member 35. In the end wall of the socket portion 32 is an opening 34 through which the flexible wires, 0 of the electric conductor cord, 0, extend into the interior of the socket portion.

Threadedly held in the socket portion is a screw threaded plug 33 which is formed with a tapered end 36, that co-operates with the tapered internal end face 31 of the socket portion to clamp the wires, 0 of the conductor cord between them. The outer end of the screw plug is slotted, whereby a screw driver may be I, used to screw the plug up against the wires. 2 In attaching the conductor cord to the electric contact member 35, the screw plug 33 is partially unscrewed from the socket portion, the flexible wires, 0 of the conductor cord are bared for a short distance and inserted through the hole 34 into the hollow of the socket portion 32. H

The screw plug is then screwed up tightly against the wires, thereby spreading them around the tapered end of. the plug and tightly clamping the wires between the tapered faces of the" plug and socket portion 32.

With this construction and arrangement there is nodanger of shearing off the fine wires, as is likely to happen in the present day lamps of this type, but-on the contrary the fine wires are tightly gripped and effectively fastened to the contact member. After the wires have been fastened in place, the contact member is pushed back into the hollow of the sleeve-like body 28 and the entire electric connection moved back into the boss 22 until the spring seats against the shoul- -der thereof.

The electric lamp bulb 21 is put in place by inserting the shell 26- thereof into the hollow ofthe boss-'22, with the locking pins 25 passing along the bayonet slots 23 to the ends thereof and then turning the lamp bulbuntil the pins engage in the reversely bent extremities thereof. The center contact piece of the lamp bulb engages with the screw plug 33 of the contact member' 35 and moves the entire electric connection,

1:40 0, back against the spring, the latter then serv ing to hold the contact screw of the electric connection in close contact with the center contact piece of the electric lamp bulb and also serving to seat the locking pins of. the lamp bulb in the 45 reversely bent extremities of the bayonet slots. The fiat back wall l3 of the lamp casing is provided with screw holes 38, through which screws 39 may be inserted and driven into the wall of the vehicle. At the place in the wall of "'50 the vehicle where'it is desired to apply one of the lamps, a hole 40 is bored into'the wall to receive the boss 22 and a vertical hole orother passage 4! is made in the wall to receive the conductor cord, 0. The boss 22 is inserted into the hole 40 and the screws 39 are driven in through the screw holes 38 into the wooden sheathing of the wall.

It is to be observed that the electric light bulb is located co-axially with the axis of the lamp case, and this brings the filament of the lamp to a position in which neither of the pillars thereof cast any shadows toward the lens.

In case it becomes necessary to renew the electric lamp bulb the lens may be readily removed by first prying the spring ring out of the groove, thereby obtaining access to the interior of the case.

In the event that any repairs need to be made on-the electrical connection, the latter may be readily drawn out of the boss and repaired or replaced.

We. claim as new and desire to secure by Letters Patent:

In an electric lamp, a castmetal disc-like case comprised of a fiat back wall having an annular lens holding flange projecting forwardly from the margin of the front face of the back wall, and a centrally disposed hollow boss-projecting rearwardly from the rear face thereof, the boss having a narrow annular internal shoulder formed at its rear extremity defining a large opening within the shouldered part, and the hollow in the boss-between said shoulder and the front face of the back wall being of greater diameter throughout than that of the openingat the extremity of the boss, there being oppositely disposed bayonet slots formed in the internal face of the boss extending back from the front face of. the-back wall, adapted to receive the usual locking pins of an electric lamp, a flanged, centre-contact insulating block loosely held in the hollow of the boss and arranged for attachment to a conductor cord, which enters the boss through-the large opening at the rear extremity ofthe boss, and a coiled compression spring interposedbetween the shoulder of. the boss and the flange of the block and arranged to press the centre-contact in the block against the centre-contact of the electric lamp, the block, together with the conductor cord, being capable of withdrawal through the front end of the hollow boss.

CARL P. SORENSEN.

PETER GIMSE.

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