US2611073A - Wheat - Google Patents

Description

Sept. 16, 1952 G, WHEAT 2,611,073

REFLEcToR APPARATUS FOR MINERS' LAMPS 2 sHEE'rs-SHEET 1 Filed June 30. 1949 Sept. 16, 1952 G. WHEAT 2,611,073

REPLECTOR APPARATUS PoR MINERSy LAMPS Filed June 5o, 1949 Y2- SHEETS- SHEET 2 Patented Sept. 16, 1952 REFLECTOR APPARA TUS FOR MINERS AMPS Grant Wheat, Marlboro, Mass., assigner to Koehler Manufacturing Company, Marlboro, Mass., a corporation of Massachusetts Application June 30, 1949, Serial No. 102,327

(Cl. 24U-44.1)

' 5 Claims. 1

This invention relates to reflector apparatus for miners lamps of the type commonly referred to as cap lamps" because they are customarily worn on a cap or hat. The Ainvention will herein be disclosed as embodied in a lamp structure of the general type shown in my earlier Patent No. 2,312,613, granted March 2, 1943, although it is not limited in its application to lamps of this particular construction. i

In miners lamps of the general type disclosed in said patent, a reflector is mounted in a stationaryposition in the lamp chamber of the headpiece behind the lamp bulb, and the bulb lalso is supported in a substantially fixed position in the headpiece. In the particular lamp shown in said patent the bulb is held under spring pressure against the glass front or lens which closes the forward end of the lamp chamber so that if this front is broken the bulb will be moved forward and the contact between the lamp and one of its supply terminals will be interrupted, thus shutting off the ow of current to the lamp and eliminating the danger of an explosion, in the event that the accident takes place in an explosive atmosphere.

In order to ensure the proper focusing of the light beam delivered by these lamps, the lamp bulbs must be so selected that the filament will be correctly placed in the bulb so that when the bulb is in its operative position the filament will be located at the focal point of the reflector. This involves a pre-testing of a large number of bulbs in order to select those which will satisfactorily meet the requirements just outlined, and this testing and selecting process is timeconsuming and expensive.

The present invention aims to devise a miners lamp in which a standard bulb can be used and the reflector can be so adjusted as to make its focal point coincide with the filament in the lamp bulb. -It is also an object of this invention to produce the result just described without interfering in any way with the safety feature of the headpiece, as above described.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims.

In the drawings,

Fig. 1 is a plan view ofthe interior of a headpiece embodying features of this invention, the View being on a large scale;

Fig. 2 is a fragmentary, sectional view showing on a still larger scale, some of l,the features of -this invention:

Fig. 3 is a perspectiveview of the reflector removedfrom the headpiece; l

Fig. 4 is an elevation showing, in detail, the means for connecting theadjusting devices with the edge of the reflector;

Fig. 5 is a plan view of the inner end of the cam;

Fig. 6 is a plan view showing the manner in which the edge of the reflector is notched to receive an adjusting link; and

Fig. 'l is an elevation of the detail shown in Fig. 6, all of the foregoing figures being on a large scale.

The construction shown in the drawings comprises a casing or headpiece 2 essentially like that shown in the patent above referred to, except for features presently to be described. In this casing 'is a lamp chamber normally closed by avglass front or lens 4 held in place by a bezel 5 which is screw-threaded on to the end portion of the headpiece 2. Mounted in this chamber is van electric lamp bulb 6 of a common form supported in a standard socket 'l which, in turn, is supported on a pivoted holder 8 with which a spring is associated in such a manner as to force the holder and the lamp outwardly and to hold the bulb 6 firmly againstthe glass front 4. Or, the mounting for the socket may, itself, be of a resilient nature such as to produce this sameresult. Current is conducted to the lamp 6 through the socket, flows through the filament, and returns through a substantially stationary contact normally held in engagement with the end terminal of the lamp by the contact of the latter with the lens 4. This arrangement provides an important safety factor, as above mentioned, becauseif the glass front 4 becomes broken and the bulb also is broken, or if the bulb is fractured in any other manner, the 4spring mounting of the bulb will force the socket forward, thus breaking the contact between .the end terminal of the lamp and the stationary contact.

So far as the features above described are concerned, the construction isvessentially like that illustrated in my earlier patent.

For the purposesof this invention the reflector `Ill is supported by three metallic straps or links Il, the upper end of each link being shaped as shown in Figs. Band 4. That is, the link has notches in the opposite sides thereof` near its upper end so that it can slide laterally into another notch l2, Fig. 6, formed in the margin of the reilector. The inherent stiffness and resiliency of the link hold it in its operative position while be pushed away far enough to break'its interlocking engagement with the reflector. Because the reflector is supported solely by these three links, the latter elements may be utilized in adjusting the reflector backward and forward relatively to the bulb in order to focus it. Preferably the reflector is made slightly-smallerinv outside diameter than the internal diameter of the end of the lamp chamber so that the reflector can be moved down into the chamber, when desired.

Adjustment of the reflector is made by means of three cams, one associated with each of the links I I. These cams are alike and one is shown in detail and much enlarged in Figs. 2A and 5. As there illustrated, it comprises a cylindrical body I3 provided with a anged head I4 which is notched at opposite edges, as best shown at I5 in Fig. 5, to receive a spanner wrench by means of which the cam may be rotated inthe bore formed through the lateral wall of the headpiece 2 and in which the body I3 fits snugly. Projecting from theinner end of this part I3, andI integral with it, is van eccentric pin I '3 which extends through the horizontal slot Il, Fig. 3, formed in the base II of the link II. A washer I8 encircles the pin IB and another washer 20, dished as shown in Fig. 2, bears on the rst washer and is backed up by a third washer 2| which is keyed at I6 to the pin I6. A screw 22 threaded into a socket 24 formed in the cam holds these parts in their assembled relationship. It will thus be seen that when one of the cams is turned in its bearing in the wall of the lamp chamber, it will move the link II associated with it inward or outward, depending upon the direction of rotation. The other adjusting devices can be operated in the same way. Thus the reilector can be adjusted to focus the lamp very accurately. Because all of the devices are accessible from outside the headpiece, the adjustment can be made easily whenever necessary and theparts will remain in their adjusted position because of the frictional resistance to change. Such resistance is provided by the tension washer 20, the outer margin of which is pressed against the washer I8 by the washer 2l and screw 22.

While the construction shown in Fig. 2- is suitable for some designs, that shown in Fig. 1 is preferable in most cases. Here the cams I3 are mounted in bosses 25 integral with the case 2 where they are completely protected but still accessible. Also, corresponding bosses 26 are provided on the inside of the case and they are shaped to receive and guide the opposite parallel edges of the bases I I of the links I I.

Thus the invention provides a construction in which the reflector can easily be adjusted to position its focal point in the filament of the lamp, and the necessity for the laborious testing of lamps, as above described, is eliminated. Also, the adjusting devices are positioned entirely within the outside surface of the casing where they are completely protected and no parts of them are left projecting beyond that surface where they might catch on the handsl or clothing of the user.

While I have herein shown and described a preferred embodiment of my invention, it will be evident that the invention is susceptible of embodiment in other forms without departing from the spirit or scope thereof.

Having thus described my invention, what I desire to claim as new is:

1. A miners lamp comprising a headpiece provided with a lamp chamber, a light transmitting front platel closing the forward end of said chamber, spring means for resiliently supporting an electric lamp bulb in said chamber against said front plate, a reector associated with said bulb to reflect light from it through said front plate, means for supporting the reilector in a positionV such that-the lamp is free to move relatively thereto, said reflector supporting means including a plurality ofveccentric adjusting devices connected with said reflector and operable fromipointsoutside of said headpiece to adjust said reflector relatively to said bulb.

2. A miners lamp according to preceding claim 1, in which eachof'said eccentric adjusting devices includes al link releasably engaged with the rim of said reiiector, and an eccentric element operatively connected to the link.

3. A miners lamp according to preceding claim l, in which each of said adjusting devices includes a slotted link releasably interlocked with thereflector and an eccentric element rotatably mountedin the wall of said headpiece and associatedwithsaid link to cause its rotative movements to movethe link and the part of the reflector to which itis connected backward and forward in the headpiece.

4. A miners lamp according to preceding claim 1, in which each of said adjusting devices comprises an eccentric element mounted in recessed relationship in the wall of the headpiece for rotative movement, and a link connecting said eccentric with the lmargin of the reflector.

5. A miners lamp comprising a headpiece provided with a lamp chamber having a lamp therein, electrical contact means for completing an electrical path through said lamp, a lamp socket having the lamp secured therein, said lamp socket being resiliently mounted for movement in to and out of contact with the said electrical contact means, a front plate arranged to close the forward end of said lamp chamber, said front plate cooperating with the lamp socket to normally hold the lamp in contact with the electrical means, a concave reflector member associated with the bulb to reflect light from it,

L means for supporting the vreflector in a position such that the said lamp socket is free to move away from the electrical contact means, said reflector-supporting means including a plurality of slotted arms releasably engaged with the rim of the reector, guideway means provided in the side wall of the headpiece at spaced-apart points for slidably-containing the slotted arms, and a plurality of eccentric elements rotatably mounted through the side wall of the headpiece and said slotted arms for axially adjusting the reector in the lamp chamber.

GRANT WHEAT.

REFERENCES CITED The following references are of record in the i'lle of this patent:

UNITED STATES PATENTS

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