US1584539A - Focusing and switch mechanism - Google Patents

Description

, I i 1,584,539 .N. M. 'HOPKINS A' FO'GUSI'NGA AND SWITCH MEGHANISM` Filed Feb. e, 19295 r 0 J6 A Patented May 11, 1926. y

UNITED STATE-sA PATENT OFFICE.

NEVIL MONROE HOPKINS', OF NEW' YORK, N. Y., ASSIGNOR, BY MESNEAASSIGNMENTS.

T0 NATIONAL CARBON COMPANY, INC., OF N EW YORK, N. Y., A CORPORATION Ol' NEW YORK.

FOCUSING AND SWITCH MECHANISM.

Application filed February 6, 1922. Serial No. 534,578.

Thisinvention relates to focusing and switch mechanism for electric lighting dcvices. The invent-ion is available for use in any connection where such means are desirable. but it has particular reference to the adjustment of 'the position of lamp bulbs with relation to the reflect-ors of portable battery 'operated lamps, and to completing Athe electrical circuit including the batter;v

and the filament of-the bulb.

In devices of this kind, it is highly advantageous to provide adjusting means for shifting the position of the source of light within the reflector. Such construction permits the user of the lamp to secure at will a diffused or concentrated illumination according to his requirements. From the manufacturing standpoint, also, it provides a way to compensate for'the unavoidable minor variations in construction and assembly which frequently result in the permanently detective focus of rigidly mounted bulbs. Various devicesvhave been proposed to secure (these and other advantages of the focusing construction.

I have devised a simplified and improved -focusing mechanism, Which in the preferred form ofthe invention operates also to make or break the electrical circuit through the filament. The construction comprises broadly a shaft operable from the exteriorof the lamp casing and carrying a cam or equivalent means, adaptedv to adjust the yposition of a slidably mounted lamp bulb. The cam or equivalent means in certain adjusted positions may complete the electrical circuit through the lamp. An important advantage of this circuit-closing arrangement lies in the fact that a Wipe 0r friction contact ismade with both the inner terminal of the lamp and the brass cap o n the central electrode of the battery. In this way clean metal surfaces are mamtained and good electrical contact is assured. More over, the combination of the focusing and circuitclosing functions in a singleelement is a marked advance in battery llamp construction. Further novel and advantageous features of the invention will be apparent from the succeeding description, taken vin connection vwith the accompanying drawings in whichv F ig. 1 is a vertical central section through ajtubular flashlight embodying the invention.

portion only, showing the canrin circuit breaking position,

Fig. 3 is a section on line III-III, Fig. 2, Fig. 4 is a section showing the cam and supporting member, taken on line IV-IV, Fig. 3, looking in the direction indicated by vthe arrows,

Fig. 5 is a vertical central section through the upper part of a flashlight fitted With -a modified form ot' the invention, and

Fig. 6 is a similar view illustrating a form of the invention inwhich a Wedge is used to focus the lamp.

Referring to Figs. 1 toet of the drawthe stem of an incandescent lamp. TheY holder` 6 has a circular base 7 extending be-l yond the sleeve 5 and providedat its margin With an upstanding rlm 8. The bottoni coils of a spring 9, encircling sleeve 5, are

received Within the annular space defined by rim 8 and the topmost coil of the spring abuts against the base of the refiector. A disc of insulating material 10 is secured to the under surface 'of holder 6, as by threading the central portion of the disc'to engage thelthreads of the holder. lA conductive rivet 11 passes centrally through. the disc 10 and engages the inner terminal of the lamp.

Proceeding now to describe the parts in which my invention Imore particularly resides, a shaft 12 isjournaled in insulating .blocks 13 and 14 s et into the walls of head 2, and one'end of the shaft extends outward# 1y beyond block 14. A collarl prevents lateral movement of the shaft. A thumbpiece or finger plece 16 1s secured to the Fig. 2 is a similar View, through the upper projecting end of the shaft and is adapted to rotate the same. The thumb-piece may be made in the usual knurled or fiuted circular form, or in any other suitable configuration. Insulating block 14 is of sufficient area to prevent contact of the thumb-piece with the head. A spring 17 may be placed between the thumb-piece and the head to keep the collar 15 under tension against the block, but the spring is not essential.

A cam or eccentric 18 is rigidly mounted or fast on shaft 12' and is in vertical alinement'with the conductive rivet 11 and the central electrode of the battery. A spiral spring 19 beneath the battery presses it upwardly so that continuous contact is maintained between the central electrode and the cam. The head is preferably annularly recessed as shown at 2O so as to limit the movement of the battery toward the cam and lamp. A semicircular pla-te 21 is mounted on the shaft and extends upwardly therefrom to serve as a support for the bulb holder 6 when the cam is out of operative position,

as shown in Figs. 3 and 4.

To operate the device, the thumb-piece is .rotated to bring the cam surface into conshifting the lamp with respect to the focus of the reflector 3. Fig. 1 illustrates the bulb in substantially its outermost position.l

Fig. o' illustrates an embodiment of the invention in which the rivet 114 is replaced by a pin 11 having a pointed lower end adapted fto engage serrations on a modified form of ,cam 18. In the device of Figs. 1 to4, the' lamp is held in adjusted position by the frictionalv engagement of the cammin'g means with adjacent parts, and this is-entirely satisfactory for morst purposes. The cooperating pointed pin and-serrated cam of Fig. 5, however, afford positive means for preventing slipping and may be used with advantage in some cases.

In the form of the invention illustrated in Fig. 6, a rod 22 is mounted in an insulating late 23 secured to. one side of head 2', and 1s depressible through an opening in an alined insulating disc 24 set in the opposite side of 'the casing. A spring 17 bearing against an abutment 25 secured to the rod 22 opposes depression of the rod. A wedge member 26, having an inclined upper surface 27, is secured to the rod and is adapted to be. moved thereby into or out of contact with the conductive 'rivet 11'?.v 'The rivet has a' rounded lower end cooperating with the inclined surface and its upper end is in engagement with the inner lamp terv22 is pushed inwardly, bringing the inclined surface 27 into contact with the rivet 11 and closing the circuit through the filament. Further depression of the rod causes the wedge to move the bulb-holder upwardly until the desired focal' adjustment is secured. Y

I prefer to make a metal head, of the type illustrated, to support the bulb and focusing mechanism. The head 2 is best made by die-casting a suitable metal or alloy. Various such materials are available, but by way of example it may be said that an alloy consisting of 90% aluminum, 4% nickel, and 6% copper, is. suitable. Openings 28 are formed through the wall of casing 1 and the metal may be cast through and about these openings to anchor the head securely in position. In case a non-metallic tube. for example a fiber tube, is used, the head metal should have a relatively low melting point and should set rapidly so as to avoid charring or burning ofthe fiber or the like. I have found that die-casting is the most advantageous method of preparing metal heads for battery lamps. By this process a unitary reflector and casing head, provided with all necessary threads and orifices, may' be formed by a single operation and at the same time rigidly secured to the battery cas. ing.

In all the forms'of the invention. the adjustment will preferably be such that when the circuit 'isl first closed lthe lamp will be in proper focus for the purpose for which the device is primarily intended. For example, in spotlight devices, on closing the circuit the source of light may be so positioned as to give a narrow, powerful beam. If it is desired to increase the area of illumination the bulb is moved forwardly to the desired extent. The frictional engagement of the cooperating parts of the focusing device, under the compressive force of springs 9 and 19, holds them securely in any adjusted position.

The lamp is very easily operated; thc thumb of the hand holding the flashlight can readily depress the rod 22 or rotate the thumb-piece 16Y to secure the desiredl adjustment'. Itwill be noticed also that a wipe orfiricti'on. contact is made on every actuation of the cam or wedge, thus insursuch' electrode and terminal and simultaneously to adjust the relative position of the .lamp and reflector.

15. In a flashlight, the combination of an incandescent lamp, a reflector therefor, a battery having a contact in circuit with said lamp, and means for effecting relative adjustment of said lamp and said reflector to alter` the spread of the reflected light, such adjusting means comprising means operative to wipe said contact.

16. In a flashlight, a lamp, a reflector, a battery, a casing enclosing the lamp, reflecfor and battey, a rotatable finger piece accessible from the exterior of the casing, and a rotary cam within the casing between the battery and the lamp, rigidly connected with said finger piece, and rotatable thereby for relatively adjusting the lamp and the reflector. I

17. A flashlight comprising the combination of a casing, a reflector, an incandescent lamp, a holder therefor adjustable relatively to said reflector to alter the spread of the reflected light, a battery in said casing in circuit with said lamp, cam means in said casing between said' battery and said holder arrangedto move the holder in one direction, and a spring acting in opposition to the cam and arranged to move the holder` in the opposite direction independently ofthe cam lwhen the cam is operated to permit such movement.

18. A battery-operated hand lamp comprising the combination of a lamp bulb, a

battery in circuit therewith, a reflector, a-

. switch formaking and breaking such cirof a member provided with a reflecting surface, one of such parts being cast onto the other to provide interfitting portions. uniting it to such other part.

22. In a lighting device,the combination with a casingr body; of a head cast in interitling relation to a portion of said body and comprising a cavity having a reflecting surface, said head also having coupling means formed integral therewith; a cover glass; and means cooperating with said coupling means to retain said glass on said head in front of said surface.

23. In a flashlight including, a lamp, a battery in circuit with thcilamp, and a reflector, the combination of a switch for closing the circuit to the lamp and means adapted to be actuated by the switch for changing the relative positions between the lampand reflector for focusing the rays from the lamp.

24. In a flashlight including a lamp, a battery in circuit with the lamp, and a reflector', the combination of a movable switch foi closing the circuit to the lamp, and means having connections with the switch movable by the switch for varying the relation between the lamp and reflector for focusing the rays from the lamp.

25. In a flashlight including a lamp, a

battery in circuit with the lamp, and a reflector, the combination of a movable switch for closing the circuit to the lamp, and means having connections with the switch and movable by the switch for varying the position of the lamp relative to the reflector for focusing the rays from the lamp. 26. In a flashlight including a lamp, a battery in circuit with the lamp, and a reflector, the combination of a movable switch for closing the circuit to the lamp, means carried by the lamp adapted to be moved by the actuation of the switch for shifting the position of the lamp relative to the reflector for focusing the light rays of the lamp.

2T. In a flashlight including a lamp, a bat-i tery in circuit with the lamp, and a reflector, the combination of a movable switch for closing the circuit to the lamp, means cmbracing the lamp and actuated by the movable switch for moving the lamp relative to the reflector.

28. In a flashlight including a lamp, a battery in circuit with the lamp, and a reflector, the combination of a movable switch for closing the circuit to the lamp, said reflector having a perforation through which the lamp is movable, means operated by the switch for closing the circuit and varying the position of the lamp relative to the reflector and whereby the lamp is moved through the perforation `in said reflector for focusing the light rays.

In testimony whereof, I affix my signature.

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