US1761438A - Electric lamp - Google Patents

Description

Jun 3, 1930. H. A. DOUGLAS ELECTRIC LAMP I Filed Jime 14, 1929 iii/(5 07 JozgZaa Patented June 3, 1930 PATENT QFFICE HARRY A. DOUGLAS, 01 IBR-O'NSON, MICHIGAN ELECTRIC LAMP Application filed June 14,

. My invention relates to electric lamps employing shields for partially obstructing light emanating therefrom.

. In accordance with my invention, the shield is made adjustable and is in controlling relation to a switch that governs the circuit of the associated lamp so that'when the shield is in one position the lamp circuit is closed and when in an alternative position the lamp circuit is opened. Inthe preferred embodiment of the invention, such adjustable shield constitutes the shutter for an opening in a cowl that surrounds the lamp and which cowl serves further to obstruct light emanating from the lamp, such shutter serving to close the switch when the shutter is opened and to open theswitch when the shutter is moved in a closing direction sufficiently to completely close the opening, though the invention is not to be thus restricted.

The invention will be more fully explained in connection with the accompanying drawing in which Fig. 1 is a front view illustrating the preferred embodiment of my invention adapted to furnish illumination for the instrument board of an automotive vehicle, the shutter being shown in an open position; Fig. 2 is a sectional view on line 2-2 of Fig. 1; Fig. 3 is a sectional view on line 3+3 of Fig. 2; Fig. 4 is a sectional view on line H of Fig. 3 Fig. 5 is a sectional View on line 55 of Fig. 3; Fig. 6 is a view similar to Fig. i but showing the shutter in a closed position; and Fig. 7 is a sectional view on line 7-7 of Fig. 5, parts being broken away.

The cowl 1, preferably metallic, is of any suitable shape. This cowl is electrically grounded. As illustrated, it is oblong and has flat top and bottom sides which are joined by semi-cylindrical end portions 2 and 3 and a rounded front portion 1. A metallic shutter is provided to open and close the opening 5 in the'cowl, said shutter having transverse l. extendin ears 5 5 which are 'ournaled y a: a

upon the inner and reduced ends of metallic pins 5 of the cowl. The shutter may be provided with a thumb and finger piece 5 whereby it may be opened and closed. The light emitting opening 5 extends lengthwise of the cowl but terminates, at each end, short 1929. Serial No. 370,871.

of the semi-cylindrical portions 2 and 3 since it is found that this opening need not be sector shaped when the structure is used upon the dash board of an automobile. The metallic lampsocket 6 is provided with tongues 7 at its front end which are clinched against the front side of an oblong plate 8 of insulation which is surrounded by and snugly received within tl e rear end of the cowl, the plate 8 having some tongues 9 which enter spaces between the tongues 7, these tongues 7 clamping the plate against the body of the socket 6. By this arrangement, the socket is firmly held from movement in any direction with respect to the insulating plate which insulates the socket from the cowl.

inwardly projecting attaching formations, preferably tongues, 10 and 11 are integrally formed with the cowl near the ends and at the top side thereof. Inwardly projecting tongues 12 and13 are integrally formed with the cowl near the ends and at the bottom side thereof. The tongues 10 and 12 are in lapping relation as are the tongues 11 and 13. Registering holes 14 are formed in the tongues 10 and 12 and registering holes 15 are formed in the tongues 11 and 13. The holes 14: are in register with the hole 16 formed in the insulating plate 8 and the holes 15 are in register with another hole 17 formed in said plate; The shanks 18 of assembling bolts are passed through the holes that are in register and through holes in a mounting or instrument board 19. The heads of the bolts are within the cowl and engage the tongues 12 and 13. Nuts 20 are screwed upon the threaded shanks of'the bolts, said mounting board, the plate 8 and the tongues through which the bolt shanks pass being clamped by the nuts between the bolt heads and the nuts whereby the cowl and the lamp socket are secured in fixed position upon the mounting board. Said socket projects through an opening 21 which is formed in the mounting board.

The front end of the socket is provided with bayonet slots or channels 22 which are adapted to receive the metallic bayonet pins or projections 23 extending radially from the base 2 1 of an incandescent lamp bulb 25, this bulb being entirely within the interior of the cowl when its base is fully assembled with said socket. I have illustrated a single pole lamp in which one terminal of the filament is suitably connected with a metallic sheath provided upon the base of the lamp bulb to have electrical contacts with the metallic socket 6 and to be further placed in electrical connection with this socket through the intermediation of the metallic pins 23 that are electrically connected with said sheath. The other terminal of the filament is connected with the contact button 26 that is provided upon and insulated from the rear end of the base 2&. The lamp socket 6 encloses a coiled spring 2'? and two insulating washers 28 and 29 between which the spring is interposed, the rear washer 29 being seated upon the inturned rear end of socket 6 and the forward washer 28 carrying a contact 30 which is pressed, by the spring 27, into electrical engagement with the contact 26. The wire 31 extends from one pole of a battery, whose other pole is grounded, and terminates in the contact 30.

The socket 6 has an elongated late-rally ex tending continuation 32 that is integrally formed therewith and which terminates in a cam portion 33 which is located in the region of the ear 5 upon the shutter. A cam 34 is mechanically connected with the ear 5 The cam 34 moves with and is so related to the shutter 5 that when the shutter is opened, such cam 34' will be free from the cam 33 to permit contact 32 to press against the metallic cowl 1 to complete the electrical connection between the grounded pole of the battery and the metallic socket 6, (Figs. 3 and 1') this connection being extended through the metallic bayonet pins 23 and the sheath upon the lamp base to one terminal of the filament, the other terminal of the filament being connected with the ungrounded pole of the battery as previously described. Thus the lamp circuit is closed when the shutter is opened. When the shutter is closed, the aforesaid cam 34 engages the cam 33 to separate contact 32 from the cowl (Figs. 5 and 6) to open the lamp circuit. By this arrangement, the provision of a separate and individually operated switch upon the instrument board for controlling the lamp circuit is not required, the equipment being thus cheapened and space being economized.

A finishing washer 35 of dish form may receive the rear of the cowl. This finishing washer has openings 36 through which the bolt shanks are passed. The margins of the openings 36 initially enter the screw threads of the bolt shanks, slots 37 radiating from said openings 36 to facilitate the threaded engagement of the bolts with such opening margins. The bolts have annular recesses 38 adjacent the bolt heads and clear of the threads in which recesses the margins of the openings 36 are ultimately received when the bolts are sufficiently turned whereby the bolts may thereafter be turned without disturbing the Washers which are thereby prevented from interfering with the mounting of the structure which is effected by the bolts. When the margins of the openings 36 are received in the recesses 38, such margins are not readily restored into engagement with the threads of the bolts, which threads thus serve to maintain the washers in place about the bolt shankswhile the devices are in shipment and in stock and before they are assembled with mounting boards, a feature of much advantage, it not being necessary to rely upon the nuts for this purpose. When the devices are to be mounted in place, it is merely necessary to project the threaded bolt shanks through the corresponding holes in the mounting boards and thereafter apply the clamping nuts.

Having thus described my invention, I claim:

1. The combination with an electric incandescent lamp having a metallic sheath upon its base and a filament having one terminal in electrical connection with this sheath; of a metallic socket receiving the base of the lamp and with which said sheath is engaged; an adjustable shutter for obstructing light emanating from the lamp; and a switch for opening and closing the circuit of the lamp and operable by the shutter, the aforesaid metallic socket having an extension constitutin one of the contacts of the switch, the switch and shutter being so related that the switch is opened when the shutter is closed and the switch is closed when the shutter is open.

2. The structure of claim 1 wherein the lamp is provided with a metallic cowl that is in the lamp circuit and which cowl constitutes a switch contact complemental to the contact that is formed of the socket extension.

In witness whereof, I hereunto subscribe my name.

HARRY A. DOUGLAS.

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