US565861A - Electric-arc lamp - Google Patents

Description

UNITED STATES PATENT OEEicE.

JOHN A. MOSHER AND WVILLIAM S. BARTI-IOLOMEXV, OF CHICAGO, ILLINOIS.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 565,861, dated August 11, 1896.

Application filed September 23, 1895. Serial No. 56 3,3 18. (N model.)

7 WILLIAM S. BARTHOLOMEW, citizens of the being warping in baking.

United States, and residents of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Electric Arc Lamps, of which the following is a specification,and which is fully illustrated in the accompanying drawings.

This invention relates to the construction of the frame of the lamp and more particularly' to the manner of holding and guiding the carbons. Its purpose is to provide a loose or jointed attachment of the carbons while insuring a perfect contact at their points.

The invention is carried into effect by providin g a universal joint for the carbon-holders and guide-plates for their tips, so that while the buttv of the carbon is free to move laterally its tip is limited to a longitudinal movement.

NVhile the invention is applicable to any lamp having a localized arc, it is of especial value in connection with the lamp forming the subject of Letters Patent No. 544,066, issued to J ohn A. lWIosher August 6, 1895, in which the arc is formed and maintained between points of the carbon electrodes in actual and continual contact.

It is found in practice that the carbon pencils are not uniform in shape, a common fault It is important that the electrodes should approach each other directly, and hence that any irregularities in the form of the pencils be compensated for by adjustment at their butts, as a warped or otherwise distorted carbon is apt to bind in the guide-plate intended to bring its tip into proper position unless free to move at its butt.

The difficulties referred to are entirely overcome in the lamp hereinafter described and illustrated in the accompanying drawings, in which Figure 1 is an elevation of the lamp-frame. Fig. 2 is a plan view of the upper carbonholder. Fig. 3 is a sectional view on the line 3 3 of Fig. 2. Fig. 4 is a plan view of the lower carbon-holder. Fig. 5 is a sectional view on the line 5 5 of Fig. 4:. Figs. 6 and 7 are plan sections on the lines 6 6 and '7 7, respectively, of Fig. l; and Fig. 8 is a plan view of the cross-plate at the bottom of the frame.

The two main members of the frame, commonly called the posts, are shown atA A, and are pendent from a top plate B and tied together near their lower ends by a cross-bar a, apertured for the passage therethrough of the upper carbon.

A pair of guide-rods O 0, parallel with the posts A A and between the latter, are secured to the top plate B and cross-bar a, and are insulated from both of these parts.

A traveling block D runs upon the guiderods 0 O and constitutes the upper carbonholder in the preferred form of construction, having a central vertical aperture 6 for the reception of the carbon pencil E, a lateral way extending from the aperture c, a clamping-block F, located within the way, and a thumb-screw f, extending from the side of the block D and bearing against the clampingblock to force it against the carbon.

The block D is so mounted upon the rods O O as to prevent it from having any lateral motion and yet allow it to freely tilt. This is accomplished by giving it a knife-edge hearing upon the rods, formed as shown, by first drilling the block to form apertures cl for the rods O O, and within which they will make a close fit, and then counter-boring these apertures from each end almost half through the block, leaving only a narrow annular rib d tapering to an edge and having bearing contact with the guide-rods.

The aperture in the cross-bar ais sufficiently large to allow the carbon to pass without contact. A guide-plateG is secured to and elec trically insulated from the cross-bar a, and has an aperture through which the carbon may pass, but without lateral play. The are is located immediately below thecross-bar a.

The posts A A are prolonged a little beyond the location of the arc and their lower ends are turned inwardly,as shown,and united by a guide-plate g, for the lower carbon.

Pendent from the inturned ends of the posts A A are a pair of parallel rods J J, upon which runs a traveling cross-head L, carrying the lower carbon-holder. This carbon-holder is a block M, apertured for the passage therethrough of the carbon and having a lateral extension M within which is carried a clamping-block m, which may be forced against the carbon pencil by a thumb-screw in.

The traveler L is apertured, the sides of the aperture being beveled from above. The bottom of the block M is rounded to adapt it to the aperture of the traveler, and from this rounded bottom depend two oppositely-disposed lugs O O, which, after passing through the aperture of the traveler are turned back sufficiently to lock the block and traveler together, yet not enough to prevent the free play of the block.

I11 the lamp described in the patent referred to the carbons become and remain pointed. The con tact-points become highly heated and fused together, forming a neck. Any lateral displacement of one of the electrodes would destroy the integrity of this neck and greatly impair the efficiency of the lamp. Should the carbons not be perfectly straight, it is obvious that their tips will get out of true alinement unless the irregularity of form is in some way compensated for. The use of a guide-plate near the arc is impracticable without a loose attachment at the holder, as a warped pencil will necessarily bin d in the guide-plate unless its butt can move sufficiently to compensate for the irregularity in its shape. Sufficient lateral play at the butt of the carbon is provided in the construction shown, while the movement is so much farther from the guide plate than is the are that it does not perceptibly change the position of the contact-point.

In order to shorten the frame as much as possible, provision is made for trimming the lamp by passing both carbons up from below the tie-plate K at the bottom of the rods J J having an aperture is of sufficient size to receive the carbons, so that in trimming the upper carbon is inserted through this plate and passed up through the lower carbonholder and the guide-plates to its proper position, the lower carbon then being introduced in the same Way.

The current is brought to the portion of the frame of the lamp herein described by the wires S T, one of which, as S, is insulated from the frame and connected with the traveler D by means of the plate 92, attached to the, top plate 13, the wires 8 s and the bindingscrews 3 s set in the traveler. The other wire, as T, is electrically connected with the frame, and the current reaches the lower carbon H, either through the frame itself or through the Wires if, employed to insure a good circuit leading from the posts A A to binding-screws t If set in the block M. A rod P is fixed in an extension of the traveler L and extends upwardly through and slides in apertures in the bent end of one of the posts A and in the cross-bar a. A cord or chain 1) leads from the upper end of the rod P over a pair of sheaves q, suitably jonrna-led above the plate 13 and down to the traveler D. The carbon feed is accomplished by gravity, the traveler D being made heavier than the traveler L, so that as the carbons are consumed the former falls and the latter is elevated.

\Ve claim 1. In an arc-lamp, the combination with a frame having vertical guide-rods, of a carbonholder adapted to slide upon the guide-rods and having a knife-edge bearing thereupon, substantially as described and for the purpose specified.

2. In an arc-lamp, the combination with a frame having guide-rods, of an apertured cross-head adapted to reciprocate upon the rods, the walls of its aperture being beveled from above, a carbon-holder adapted to rest within the aperture of the cross-head, an d retaining lugs or claws projecting from the holder through the cross-head aperture and being spread to loosely engage the cross-head, substantially as described and for the purpose specified.

In an arc-lamp, the combination with a frame having upright members or posts and with upper and lower carbon-holders, of a cross -head for carrying the lower carbonholder and a tie-plate for uniting the lower ends of the upright members of the frame, such cross-head and tie-plate being apertured for the passage therethrough of the carbon pencils, substantially as described and for the purpose specified.

4:. In an arc-lamp, the combination with the frame having upright members or posts, and with guide-plates secured to the frame for preventing angular movement of the tips of the carbon pencils, of traveling carbon-holders, and a tie-plate forming the bottom of the frame, such tie-plate and the lower carbonholder being vertically apertured to admit of the introduction of the carbons therethrough in trimming, substantially as described and for the purpose specified.

In testimony whereof we aflix our signatures in presence of two witnesses.

JOHN A. HOSIIER. XVILLIAM S. BARTIIOLOME\V. lVitnesses:

Louis K. GILLSON, MILO B. GILLsON.

ICC

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