US320841A - Ingham - Google Patents

Description

(No Model.)

0. L. BUCKINGHAM- BESTAVAILABLE COP ELBGTRIQ ARC LAMP.

N0. 3Z0 ,841. Patented June 23, 1885.

WITNESSES: INVEN TOR N. PE ERS. mmmmmr. waun im DJ.

BEST AVAILABLE COP.

UNITED STATES PATENT OFFICE.

CHARLES L. BUOKINGHAM, on NEW YORK, n. Y.

ELECTRIC-ARC LAMP.

EPECIFICATION forming part of Letters Patent No. 320,841, dated June 23, 1885. Application filed August 26,. 18554. (No model.)

To all whom it may concern:

Be it known that I, CHARLES L. BUCK- INGHAM, of the city, county, and' State'of New York, a citizen of the United States of America, have made a new and useful. Improvement in Electric-Arc Lamps, of which the following is a specification.

My invention is an improvement in that class of lamps in which, first, an electro-magnet in the arc-branch primarily separates the carbons to establish an arc, and then causes the lilting-clutch to release the carbon-holder, leaving it suspended by a second and independent support; second, the feeding of the carbons is controlled by a second and shuntbrancli electro-magnet. In lamps of this particular class, as well as those in general in which the arc is established by an arcbranch eleetro-magnet, it often occurs that, while the current is flowing in full strength through said electro-magnet, the carbonholder slips through its lifting-clutch, thus permitting the carbons to come together while the lifting-clutch is in its extreme upward position. It is obvious that it is then incapacitated from lifting the carbon-holder. to reestablish the are. To re-establish the are it would be necessary either for an attendant to go to the lamp and manually separate the carbon points, or else that the current on the line be temporarily suspended, thereby permitting the clutch to fall to its lowest position. The clutch when in its lowest position is assumed to be capable of establishing an are upon a resumption of current.

The object of my invention is to enable an arc to be instantaneously reestablished at any time, in the event of an accidental slipping together of the carbon points, while a current of full strength is flowing over the are-branch. To this end I employ a shunt of low resistance around the arc-branch electromagnet, and said shunt is opened and closed through the agency of an electro-magnet which is included in the fine-wire shuntbranch. This shunt-branch electro-inagnet is adapted to attract its armature at the moment an arc of normal length is established, and long before the electro-magnet in the same shunt-branch is actuated to feed the carbons together. W'ith such an arrangement it is to be observed that the current passing through the arc-branch eleetro-magnot primarily separates the carbon points and establishes an are; that at the moment the arc is established enough current will flow through the fine-wire shunt to cause one of its electro-magnets to close a short circuit around the are-branch electromagnet, thereby depriving said arc-branch electro-magnet of enough current to retain the lifting-clutch in a position of suspension; that upon the short-cireuiting of the arc-branch electromagnet the liftingclut-ch is released and falls to its lowest position, ready to again grasp and raise the carbon-holder upon the breaking of the short circuit around the arc. \Vhile a normal current is flowing through the arcbranch, enough current, at the same time, is flowing through the fine-wire shunt to cause the electro-magnet therein, above mentioned, to retain the shunt around the arc-bran ch electro-magnet closed; but in the event of the slipping together of the carbon points the arc-branch resistance is greatly reduced, and the current upon the high-resistance shuntbranch is so far reduced as to permit the shunt-branch electrounagnet to break the short circuit of the arc-branch electromagnet, thereby causinga strong current to again flow through the latter clcetro-magnet and to reestablish the are.

In my lamp the carbon-holder ishcld between rollers whose pressure is so adjusted that, when uninfluenced by either the lifting or feeding electro-magnet, said carbon-holder will be stationarily suspended between the rollers or any suitable friction-support.

To establish an are between the carbons, the arc-branch electro-inagnet is capable of lifting a carbon-holder against the action of the pressurerollers or friction su iports, and likewise to effect a feed. The influence of the liftingmagnet having first been removed, the feed- 5 ing electro-magnet is capable of forcing the carbon-holder in an opposite and downward direction against the action of the pressure-rollers or friction-support.

I will now describe my invention by refer- ICO ence to the accompanying drawing.

F is a carbon-holder, which is raised to pcsition to establish an are between C G byrollers against the action of gravity.

When the carbons are in contact, as they normally are, an arc is established by a main-line current first passing through the coils of the arc-branch electro-magnet A, whereby the hollow axial armature B is raised, and its liftingt-oe C lifts one side of the ring-clutch until it clutches and raises the'carbon-holder, and until the opposite side of the ring is arrested by, an adjustable stop, E. The main line curent is divided at point a over two branchesone including electro-magnet A and the lightgiving carbons, the other a high -resistance shun t, :2, around the are, which embraces feeding eleetro-magnet G and short-circuiting electro-magnet Hand reunites with the main circuit at w. When, now, a current isfirst sent to line, the arc is immediately established, and, when of a normal length, enough current is diverted to the shunt-branch to cause electromagnet H to attract its armature o from its back contact, 12, to its front contact, y, thereby elosin g a short circuit which begins and terminates at s and r of the arc-branch around the coils of A. When armature 0 is thus attracted, nearly the entire current of the arc-branch isdiverted from the coils of A, and armature B and the ring-clutch at once fall to their lowest posit-ion, thereby releasing the lifting-clutch from the carbon-holder and leaving it supported, with the are intact,wholly through the agency of clampingrollers I) c. Armatn re owill remain attracted and the coils of A short-circuited as long as the arc resistance continues. normally great. or throughother accident the carbons should. be brought so close together as to greatly di-' If, however, by an overfeed minish the arc-resistance, nearly the entire current of the shunt-branch would be diverted, and thereby electro-magnet H would release its armature 0, thus breaking the short circuit of A. The breaking of said short circuit will again result in a strong current in the coils of A, and the lifting-clutch will again be brought into operation and the carbon-holder lifted until the arc has attained its normal length.

Although clamping-rollers b c are adequate to support the carbon-holder against the action of gravity, the carbon-holder is readily given an upward movement by means of the lifting-magnet A, and adownward movement by means of a positive feeding apparatus. The feeding of a carbon-holder is effected through a differential electromagnet, G, having two oppositely-wound coils, j and 7c, the first of which is normally closed, while the latter is normally open between anvil Z and circuit-closing arm at, which is attached to armature-lever g. The two branches begin and terminate at o and w. When only a normal arc-resistance exists, not enough current is flowing in the shunt to cause G, through coil j, to attract its armature, and in that case the armature-lever g, pivoted at h, is held in a retracted position by spring a, and the clam ping-toe i is in its extreme upward position, and is not in contact with the carboirholder. If, however, owing to the consumption of the carbons, or for any other reason, the arc-resistance should become abnormally high, the current in coil j of G will attract its armature, and t will clutch the carbon-holder and thrust it downward a small fraction of an inch, and until an and I come in contact. hen in and Z make contact, a current is set up in 7a, and the effects of the two equal coils become neutral and the armature is retracted. After being retracted, if enough current remain in the shunt-branch to again attract the armature of G, of course the carbon-holder will be fed a second step, and the step-by-step feeding will continue until an ample feed of the carbons has occurred.

At all times when enough current is flowing in the shunt to actuate the feeding devices, armature 0 will remain attracted and Ashort-circuited; but 0 will also be attracted and A short-circuited long before the feeding devices will be operated. Although 0 should be attracted'by a weak current in the shunt, it should not be attracted before an arc is established. To render the movement of 0 slow, a dash-pot, or any well-known form of retarding device, may be employed.

What I claim,and desire to secure by Letters Patent, is

1. In an electric lamp, the combination of a lifting eleetro-magnet for establishing an are, a clamping apparatus for supporting the carbon against the action of gravity which is independent of the lifting and feeding apparatus, and a second electro-niagnet and feeding apparatus which are independent of the lifting and supporting devices.

2. In an electric lamp, the combination of an arc-branch electro-magnet, a shunt-branch electro-magnet which is called into action when the normal are is established, and a clutch for establishing the are through the agency of the arebranch electro -magnct, which clutch is unlocked from the carbon holder and returned to its normal position under the control of the shunt electro-magnet, and which remains in readiness to reestablish the are in case of an overfeeding of the carbonholder.

8. In an electric lamp, the combination of a clutch and mechanism for causing the clutch to first lift the carbon apparatus, to then. cause the clutch to release the carbon, and to imme- IIO dinteiyiei'urn snid clutch toaposition to again ed to lift and release the carbon and to be relii't said carbon upon an abnormal diminution oi arc-resistance.

4. In an electric-121111 the combination of a lifting eleotro-niagnet and a clutch, a short circuit for said lifting eleotro-magnet, and a shunt eiectro-mngnet for opening and closing sm' d shortoii'cuit, whereby the clutch is adaptturned to its original position upon the ostnb- 1o lishment of a normal are.

CHARLES L. BUOKINGHAM.

Witnesses:

J OHN D. VAN HORNE, WILLARD BROWN.

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