US2947854A

US2947854A - Miner s lamp structure including rack

Info

Publication number: US2947854A
Authority: US
Publication date: 1960-08-02
Anticipated expiration: 1977-08-02

Description

Aug. 2, 1960 H. A. LOZEAU 2,947,854

, MINERS LAMP STRUCTURE INCLUDING RACK AND PINION TYPE ADJUSTMENT MECHANISM Filed Sept. 2, 1958 FIG. 1

FIG.4

INVENTOR ATTORNEY Edited States Patent MINERS LAlVlP STRUCTURE INCLUDING RACK AND PINION TYPE ADJUSTMENT MECHANISM Homer A. Lozeau, Worcester, Mass.', assignor to Koehler Manufacturing Company, Marlboro, Mass., a corporation of Massachusetts Filed Sept. 2, 1958, Ser. No. 758,258 2 Claims. c1. 240 41.z's

ported by a suitable holding device around the waist of the miner and an electrical conductor extends from the battery upwardly to the headpiece.

Currently, miners electric cap lamps are equipped with a reflector and two bulbs, or with a two-filament bulb. In the two-filament bulb, one filament is located at or near the focal point of the reflector and the other filament is located a short distance away from the focal point. Either filament provides a satisfactory light pattern when used with a matte-finished reflector, but only the filament most nearly in focus provides a satisfactory beam when used with a specular finished reflector of the class now employed most extensively in the art. More recent cap lamp models have included a focussing device to focus the more central filament, but the second filament remains out of focus. Thus, the tendency has been for the miner to use the same focussed filament every dayand to reserve the second filament for temporary and generally unsatisfactory use in the event of burn-out of the correctly focussed filament.

" The present invention is based on the novel concept of combining filament energization and beam focussingin one simplified turning adjustment. objective, I have devised a lamp and electrical switch arrangement wherein I provide means responsive to movement of the electrical switch for focussing a reflected beam of, light from the lamp.

The combined switch and focussing arrangement of the invention, while adapted for use in focussing a light beam from either a single filament lamp or multiple filament lamp, is especially designed for use with a lamp having two filaments. The several components referred to are arranged in such relation to one another as to provide for selective operation of either filament of a two-filament lamp whereby each filament may be used interchangeably. Selective focussing of light'from each filament may be accomplished by the same turning movement which closes an electrical circuit through one or the other of the filaments.

' I have found that this concept of selective switching and simultaneous focussing may be practically embodied on one form in an adjusting lamp structure in which a unique rotor switch device is combined in interlocking relationship with a special reflector positioning apparatus. These units are so designed and organized as to provide for a tightly sealed bulb switch and reflector arrangement and, thus, a high standard of safety and durability is insured.

An important feature of the invention is the construction of a rotor type switch having a pair of electrical contact elements and a rotatable contact arm by means of To accomplish thisice which either of two filament circuits may be energized and the same rotative movement is utilized to provide for two different focussing adjustments. The latter operation is accomplished in a preferred form of the invention, by a novel gear and rack mechanism which functions to focus one filament as it is energized by a clockwise rotation of the switch arm; and which focuses the second filament as it is energized by a counter clockwise rotation of the switch arm.

7 These and other objects and novel features will be more fully understood and appreciated from the following description'of a preferred embodiment of the invention selected for purposes of illustration, and shown the accompanying drawings, in which:

Fig. 1 is a composite view in side elevation illustrating a lamp enclosure body for use with a miners cap or other supporting means, and further indicating a storage battery and an electrical conductor of the class commonly carried by a miner in conjunction with a miners cap lamp;

Fig. 2 is a cross-sectional view taken centrally of the lamp enclosure body of Fig. 1; 4

Fig. 3 is a cross sectional view taken on the line 3-3 of Fig. 2; and

Fig. 4 is a cross-section taken on the line 44 of Fig. 3.

Referring more in detail to the structure shown in the drawings, numeral 2 denotes a cup shaped lamp enclosure body which may preferably consist of Bakelite or other rigid molded plastic. As shown in Fig. 2, the enclosure body is recessed at one side to define a chamber 4 which is normally closed by means of a glass lens 6 secured in place by means of a threaded bezel 8.

7 An electrical conductor cord 10 is fastened through one side of the enclosure 2 and at its opposite end is connected toa storage battery 12 of the type normally used with electric cap lamps. At the outer rear wall portion of the enclosure 2 is a clip element 14 for use in attaching the lamp structure to a supporting part of a miners cap or the like.

At its inner rear portion, the enclosure body is recessed to form a socket opening 16 in which is secured a lamp socket 18. In this socket is detachably secured a lamp 20 which is retained in position by the lens 6 as suggested in Fig. 2. 'Also secured at one end of the socket 18 are elect'rlcal

contact elements

22 and 24. Located around the lamp 20 is a reflector element 26 which has a reduced central tubular section detachably fitted into the end of reflector sleeve 30through which projects yleldable pins 28 engageable with the tubular section of reflector ele-- ment 216, as shown. Sleeve 30 is slidably received on the socket 18 and, .when moved, is adapted to vary the position of adjustment of the reflector 26 to provide for selective focussi'ng with respect to the lamp filaments 20aand 20b.

v In accordance with the invention, I further provide on the sleeve 30 a rack portion 34 whose teeth, as shown in Fig. 2, are adapted to be engaged by a small gear 36. The latter member is mounted on a shaft 38'which is re: ceived through one side of the enclosure body 2 in a bearing portion 2a. At its outer end, the shaft 38 is provided with a k'nurled knob 40 to facilitate turning the shaft by hand.

In accordance with a further aspect of the invention, I combine with the shaft 38 an electrical rotor arm contact 42 which may, for example, be secured to an intermediate portion of the shaft as illustrated in Fig. 4. The rotor arm contact 42 is chosen of a length such that it may swing through an are which passes across the ends of two electrical contacts '22 and 24 whose extremities are fixed at the base of the lamp socket. These

electrical contacts

22 and 24 are constructed with elongated contact surfaces as shown in Fig. 4, so that when arm 42 engages one or the other of these contacts, an electrical circuit is closed through either one of the light filaments 20a and 20b, and there is a short time interval during which the shaft may be turned through a small arc of rotation. During this time interval the sleeve 30 may be advanced or retracted slightly to provide for correct focussing of the reflector in accordance with whichever filament is being energized at any given time.

Considering this switching device and its operation in greater detail, attention is directed to Fig. 4 wherein I have illustrated one of the leads from the conductor connected to a terminal 45, with the other lead being connected to a terminal 46. The position of the rotary switch arm 42, as shown in Fig. 4, is in an open circuit position, that is, neither filament is energized. However, by turning the knob 40 in a counter clockwise direction, the arm 42 is advanced into contact with the electrical contact 22 and immediately the filament a is energized with a circuit being closed through the contact 22, then to the filament 20a, then to the lamp base and socket, and then through the terminal 46 through conductor 10 to the battery. In turning the knurled knob 40 in a counter clockwise direction, the gear 36 and rack 34 cooperate to move the sleeve in a direction from. right to left as viewed in Figs. 2 and 3, which movement provides a correct focussing of the reflector 26 for the filament 20a.

An alternate operation using the filament 20b may be carried out by moving the rotor switch arm 42 from the position shown in Fig. 4 in a clockwise direction in which event the arm 42 engages the electrical contact 24 and the filament 20b is then energized with a circuit being closed through this filament to the lamp base to socket. With this clockwise rotation of the knob, the gear 36 and rack 34 retract the sleeve 30 into a position where the reflector 26 is correctly focussed for the filament 20b.

Thus it will be seen that I have provided a simplified apparatus involving a simple turning operation which when considered in relation to a miners cap enables a miner to very conveniently turn on a light beam and focus it with a single operation being carried out while the lamp is supported on the head. Such an operation may, in the event there is a sudden filament failure, be repeated to simultaneously renew the light and obtain proper focussing with little interruption or loss of time in the case of failure.

An important advantage of the invention is the broad foeussing adjustments possible since each filament permits a miner, within limits, to obtain the sharpness or spread of light beam which he finds most convenient for his work. This may vary with the type of work which a miner may be doing. For example, a miner operating from the back of a long mining machine would want as sharp a beam as possible so that it would penetrate through dust and spray. On the other hand, a man repairing a motor or doing close work underground might require a broader light pattern to minimize sharp gradations from darkness to brightness.

Another advantage of the invention is compensation for variation in the filament location which commonly occurs in the manufacture of bulbs. All bulbs, as manufactured, are not exactly uniform in the location of filament, and the invention compensates this by providing for a focus in a range of positions which will take care of any variations with a minimum of difliculty.

Another advantage of the specific arrangement described is that instead of one filament being required to operate all of the time until failure, there may be an alternating type of operation since the rotor switch may energize either one of the filaments at will. The net result of this may well be to realize longer operating life from a lamp before a bulb replacement operation is required. It will further be appreciated that the desirable two filament operation described is accomplished with both safety and durability being maintained.

The invention has been described in one preferred form in which a two filament rotor switch is combined with focussing position apparatus. It should be understood that various changes and modifications may be resorted to in connection with this structural form of the invention and, similarly, I may desire to employ the combination rotor switch and focussing apparatus with various other filament arrangements, either of a single filament or a plurality of filaments in excess of the two illustrated.

The scope of the invention is to be understood as being defined by the appended claims.

This application is a continuation-in-part of application Serial No. 702,355, filed December 12, 1957.

Having thus described my invention, what I claim is:

1. In a miners lamp, a lamp enclosure body, a lamp socket including a base portion fixed to the enclosure body and a tubular lamp receiving portion, a reflector positioned in said enclosure body including a cylindrical hub portion slidably mounted on the tubular portion of said socket, a rack extending longitudinally of said hub portion, a rotatable switch member mounted in the enclosure body having a gear engaging said rack for sliding said hub and reflector along the tubular portion of said socket, said lamp socket having a pair of electrical contact elements, a bulb member resiliently held in the socket and presenting a pair of filaments occurring in electrically connected relationship to the said electrical contact elements to constitute two independent sources through which said current may flow, a source of electrical current and electrical conductor means leading therefrom to said cont-act elements, said rotary switch device being adapted to close the circuit through said conductors to one of said filaments and simultaneously opening a circuit through the remaining filament, whereby said gear and rack mechanism actu-ates said reflector to position the latter in accordance with the filament illuminated to focus said reflector with respect to the filament energized.

2. A structure according to claim 1 in which the electrical switch means includes a pair of spaced apart electrical contacts having elongated contact tips, and a rotary arm movable into and out of engagement with the contact tips.

References Cited in the file of this patent UNITED STATES PATENTS