US1738683A - Antitheft electric-light bulb - Google Patents

Description

"Dec. 10, 1929. s. F. BASHARA- ET L ANTITHEFT ELECTRIC LIGHT BULB Fil m 1925 3 Sheets-Sheet 1 & S-F-BMBhQLWL ra /mm Dec. 10, 1929. 51 F. BASHARA ET Al. 1,738,583

ANTITHEFT ELECTRIC LIGHT BULB Filed June 22, 1925 2 Sheets-Sheet 2 Patented Dec. 10, 1929 UNITED ST T E S OFFICE AN'IITHEFT ELECTRIC-LIGHT BULB Application filed. June 22,

Our invention relates to an improvement in electric lamps, and pertains more particularly to the means of attachment between the electric bulb and the socket into which it is secured.

It is an object of the invention to provide an attachment of the bulb in the socket which will be theft proof. It is desired to form an electric bulb which may be readily attached within its socket but which cannot be readily detached without special means, or without special knowledge of the construction of the device. It is desired to construct the bulb 1n such manner that it may be attached in any ordinary lamp socket and which may be manufactured cheaply in'quantities, and at the same time not liable to be detached or stolen.

In accomplishing the results above stated,

the invention pertains largely to details of construction and arrangement of parts which will be more particularly described.

Referring to the drawing herewith, Flg. 1 is a side elevation of an electric light bulb, certain parts thereof being broken away for greater clearness, and showing a broken section of the lamp socket in central vertical section. Fig. 2 is a longitudinal section of the lamp socket showing the improved bulb secured therein, the parts being in a different position from that shown in Fig. 1. Fig. 3

is a transverse section on the plane 33 of Fig. 1. Fig. 4 is a side elevation of an electric light bulb illustrating a slightly different embodiment of the invention, the socket and the attachment means being shown in longitudinal section. Fig. 5 is a view of the upper end of the bulb showing the parts in a position different from that shown in Fig. 4.

Fig. 6 is a transverse section on the plane 6 6 of Fig. 4. Fig. 7 is a side view of an electrlc light bulb employing a slightly diflerent embodiment of the invention, the upper shank and shell of the device being shown in vertical section. Fig. 8 is a side elevation of the upper end of the construction shown in Fig. 7. Fig. 9 is a transverse section on the plane 9-9 of Fig. 7. Figs. 10 and 11 are front and side elevations respectively of the 50 Wrench which may be employed in attaching 1925. Serial No. 38,875.

and detaching a bulb with the socket. Fig. 12 is a side elevation of the shank of a bulb showing a still different means of connecting the shank of the bulb with the shell, and Fig. 13 is a transverse section on the plane 13-13 66 of Fig. 12.

In the embodiment of our invention, shown in Figs. 1 to 3 inclusive, the bulb shown is an ordinary electric light bulb having an up er shank 1, of glass-or other electrically ins ating' material, secured to the bulb 2 in the usual manner. There is mounted upon the shank of the bulb a covering, or cap, 3 of metal or some other conducting material cylindrical in shape and fitting tightly about 5 the shank of the bulb. It has at its upper end a'radial flange 4 making contact at its outer edge with a shell 5 formed with a coarse thread thereon toengage within the metallic socket 6 of ordinary construction.

Adjacent the lower end of the covering, or cap, 3 is provided a corrugated or toothed. portion 7, formed in the metal of the cap and comprising one or more teeth which form one member of a clutch. The lower end of the shell 5 is turned inwardly to contact with the shell. It has on the inwardly turned portion 28 a plurality of indentations, or rooves, 8 to receive the teeth 7 formedon t e bulb cap. These'teeth 7 and 8, forming the clutch 30 or engaging members between the cap and the shell of the base cap, are held normally out of engagement by means of a spring 9. This spring is spiral in shape, the lower end of which is seated upon the lower portion 28 35 of the shell and the upper end of which bears against the flange 4 of the cap. It thus serves to force the shank of the bulb upwardly in the shell maintaining a bulb rotatable relative to the shell.

At the upper end of the socket 6 there is a U-shaped contact member 10 adapted to close the electric circuit between the conducting wire 11 and the upper end.12 of the filament within the bulb. We contemplate that this contact member may be made to also serve as a spring to take the place of the spring 9 by constructing the'contact member as shown in Figs. 4 to 6 inclusive. In this embodiment, the shank and the'shell'and the socket are formed as in the previous embodiment. At the upper end of the shank, however, we connect a spring contact member 14 which serves the purpose of the other contact member 10, and also serves to force the shank 1'-. downwardly relative to the shell 5 furthermore there is a ridge 15 formed upon the shell 3' ada ted to fit against the lower end 28 to limit the ownward movement of the shank relative to the shell 5. In this embodiment the corrugation or teeth 7 upon the cap are formed below the inwardly turned end 28 of the shell so that the bulb will have to be moved upwardly instead of downwardly to engage the teeth 7 with the teeth formed within the end 28 of the shell.

In operating the invention thus disclosed, the bulb with the shank 1 and the cap 3 will be drawn downwardly in the Fig. 1 embodiment to engage the teeth 7 within the teeth 8 of the shell. The two parts will be thus held against relative rotation and the shell.

may be thus rotated to screw it within the socket 6 in the usual manner. When the bulb has thus been secured in the socket. the same may be released and the spring 9 will then act to force the shank of the bulb upwardly in the shell 5 so that the bulb may be rotated without affecting the screwing or unscrewing of the shell from the socket. Vhen it becomes desirable to release the bulb from the socket, this may be done by drawing the bulb downwardly within the shell engaging the teeth 7 and 8, thus making it possible to rotate the shell and unscrewing the same from the socket.

In the Fig. 4 embodiment, the bulb will have to be pushed inwardly relative to the shell 5 in order to engage the teeth 7 and 8 so as to rotate the shell with the bulb. In this manner the bulb may be screwed within the socket in the usual manner and, when fully engaged, the spring 14 forming the contact, will bear against the upper end of the socket tending to force the shank and the bulb, outwardly releasing the teeth 7 from their engagement with the shell and allowing rotation of the bulb relative to the shell and the socket.

It is believed that as the means of engaging the shell and the cap of the bulb non-rotatably together is hidden from the ordinary thief, it will serve the purpose of making the bulbtheft proof, for the ordinary thief will rotate the bulb, and, as the clutch formed by the teeth 7 and 8 is out of engagement the bulb cannot be released. This can only be done by a proper understanding of the manner in which the bulb and the shell can be engaged in the manner described.

In Figs. 7 to 11 inclusive is illustrated a third embodiment of the invention wherein the bulb can only be unscrewed from the socket by the use of a detachable member or wrench. To accomplish this purpose, the

upper shank 1' of the bulb is formed with a cap 3" substantially as that shown in Fig. 4 except that the upper end is curved inward- 1y about the upper insulated portion 16 of t 1e shank. There is formed on one side of this cap, adjacent the lower end, a corrugated section 7" forming teeth similar to those shown in Figs. 1 to 6. The shell 5" is fitted over the outer face of the cap and is rotatable thereon in its normal position. The lower end of the shell is curved inwardly into contact with the cap and has at one point a eries of corrugations or teeth8 which may be brought by rotation into position adjacent the corrugations 7 as shown in Fig. 9. It will be seen that the shell will be rotatable upon the shank of the bulb at all times except when a wrench is inserted between the toothed portion 7 and 8". Such a wrench is shown in Figs. 10 and 11. It is formed of a short handle 17 having a curved blade 18 thereon, which is corrugated as shown in Fig. 10, to fit between the shell and the cap, as shown in Fig. 7. When thus inserted, the wrench acts to lock the shell to the ca so that when the bulb is rotated the shell will also be rotated to secure the bulb within the socket. -When the bulb is thus secured in position, the wrench may be withdrawn and the bulb will be free to rotate relative to the shell and the socket.

The connection between the bulb cap and the shell may be varied in various ways coming within the spirit of our invention, and in Figs. 12 and 13 amodified form is shown. In this embodiment, the cap is formed with a longitudinal groove 19 therein, and the shell is formed with a groove 20, the groove 20 extending outwardly while the groove 19 extends inwardly relative to the shank of the bulb. To engage the cap with the shell in this embodiment, a small rod or pin 21 may be employed, and when said pin is in serted within the grooves 19 and 20, it will serve to lock the shell and the cap together so that the shell will be rotated with the rotation of the bulb.

It will be noted that in all of the embodiments of the invention shown and described, the bulb will be rotatable normally within the shell which makes engagement with the lamp socket. In each case the shank of the bulb may be engaged with the shell to rotate therewith by means manually controlled by the operator. In each case the connection between the shank of the bulb and the shell may be likened to a lock, which may be in the form of a combination lock or one involving the use of a key. Figs. 1 to 6 inclusive, there-.

fore, illustrate the combination lock and these bulbs can only be detached after once being secured within the socket by one knowing the combination. In the embodiments illustrated in Figs. 9 to 13 inclusive, the bulb can only be detached from the socket by the use of a key serving to secure the bulb within the shell.

While these forms of attachment of the bulb to the socket will not be absolutely theft I proof, they will resist attempts of ordinary patrons of hotels, or other public places, from taking the bulbs from the sockets and appropriating them. Only those knowing the means whereby the bulbs may be detached will be able to remove the bulbs when desired. The further advantages of this inventive idea will be apparent to those skilled in the art. What We claim as new and desire to protect by Letters, Patent is:

1. In an electric lamp, a bulb, a shank thereon, a cap thereon, a threaded shell normally rotatable on said cap, co-operating teeth on said cap and shell, and means adapted to be inserted between said teeth to connect said teeth whereby said cap and shell are held against relative rotation.

2. In an electric lamp, a bulb, a shank thereon, a threaded shell on said shank and normally rotatable thereon, and means insertible between said shell and said shank to secure them together, so that the rotation of said bulb will cause the rotation of said shell therewith.

3. In an electric lamp, a bulb, a shank thereon, a cap on said shank, a threaded shell on said cap, said shell being normally rotatable with respect to said cap, and manually operable means adapted for temporary in sertion between said cap and said shell whereby rotation of said bulb will cause rotation of both said cap and shell.

4. In an electric lamp, a bulb, a shank thereon, a cap fixed on said shank, a threaded shell normally rotatable with respect to said cap, and means adapted to 'be engaged between said cap and shank whereby said shell may be moved by rotation of said bulb.

5. In an electric lamp, a bulb, a. shank thereon, a threaded shell normally free to rotate on said shank, opposed spaced surfaces on said shank and s ell, and independent means adapted for temporary insertion between said shank and shell whereby said shell may be rotated with said shank.

n testimony whereof we hereunto aflix our signatures this 16th day of June, A. D.,

SAMUEL F. BASHARA. JAMES w. GAIN.

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