US1379881A - Arc striking and extinguishing apparatus - Google Patents

Description

E. A. SPERRY.

ARC STRIKING AND EXTINGUISHING APPARATUS.

- API LICATION FILED JULY 22,1916.

[WEN-TOR EL MER H. SPERRY FIG-l.

UNITED STATES PATENT OFFICE.

ELMER A. SPERRY, OF BROOKLYN, YORK.

ARC STRIKING AND EXTINGUISHING APPARATUS.

Specification of Letters Patent.

- Patented May 31, 1921.

Application filed July 22, 1916. Serial No. 110,753.

To all whom it may concern: v Be it known that I, ELMER A. SPERRY,

a citizen of the United States, residing at ordinary are light as in a .searchlight the.

electrodes are normally placed in an approximately horizontal position instead of vertical, and are quite a distance from the controlling mechanism which is necessarily placed without the drum.

The main object of the invention is to devise a simple are striking means which is 0 erable, without disturbing the position of either electrode holder or electrode, so that the structure of the electrode holders and feeding mechanism therefore may be made very simple. Another objectof the invention is to devise in connection with my novel are striking means a light extinguishing means, whereby the light from the searchlight may be shut off instantaneously, by shutting ofl:' the usual afterglow. My invention possesses especial advantages when used in connection with searchlights of the type shown in my copending application for improvements in searchlights, Serial No. 21661, filed April 16, 1915, in which for ordinary feeding, the electrode holders remain stationary, and the electrodes are fed through the holders. In this form, also, the holders are artificially cooled by air introduced through the supports for the electrodes.

Referringto the drawings, in which what I now consider to be the preferred form of my invention is shown,

Figure 1 is a vertical longitudinal section of a portion of a Searchlight, showing portions of the two electrode holders.

,Fig. 2 is a section on line 2-2, Fig. 1, the positive holder, however, being omitted.

Fig. 3 is a detail of the automatic mechanism for operating the are striking flipper.

Fig. 4 is a view of a small portion of Fig. 1, showing in full, parts which are there shown in section.

In the specific embodiment shown, both the positive holder 1 and the negative holder 2, are located within drum 10 adjacent to the arc, and the electrodes 3 and 4 are normally fed therethrough by automatic mechanism hereinafter described, actuatedv in part by electric motor 5 in the control box 6. The said control box is shown suspended withoutthe drum 10*, by means of a strip 80 on said box, running between guide strips 81 and 82 on said drum. The support 7 for holder 1, which may be taken as typical of both supports, is made hollow to serve as a duct for leading in air to the holder from the fan blower 8 operated by motor 5. To cut ofl stray light from the negative and from the arc flame, I- prefer to provide the positive holder with a shield 9.

Mounted near the arc is a movable member 10 which I term the are striking flipper. I prefer to pivotally mount the flipper to one side of the arc and actuate it automatically. As shown, the flipper is pivoted upon a shaft 11 secured to and extending from the support 7 of the holder 1. The flipper 10 may be formed of any refractory material which will conduct electricity, such as carbon or the like. It is shown as a disk 75 clamped between flanges 76, 77 on an enlarged head 78 on stem 30.

"in brackets 15 and 16 secured to standard 7. A bevel gear 18 is secured near the top of the shaft 14 and meshes with a pair of bevel gears 19 and 20, journaled on shaft 11. sleeve 21, loosely mounted on shaft 11. A hub 22 which supportsthe stem 23 of shield 13 is secured near the outer end of sleeve 21. o Bevel gear 19 is loosely mounted on sleeve 21 and has secured thereto the hub 2 1 of the stem 25 supporting shield 12. By this construction it will be seen that the two shields are rotated in opposite .directions about shaft 11 by the rotation of shaft 14; Any suitable means may be provided for holding the member 10 normally against against the electrodes. For this purpose a counter Weight 26' is shown. Counter Bevel gear 20 is secured to a long weights 27 and 28 may also be provided for the shields 12 and 13, respectively, if

desired. The hub 29 supporting stem 30 of the flipper 10 is provided with a plurality of lugs, 31, 71 and 72. Lug 31 lies. 1n the path of the stem 23' and is adapted to-be struck thereby after a predetermlned r0- tation of stem 23away from the upstandlng position, has taken place (see the dotted position 13, Fig. 2). The lug 72 is in the nature of a limit stop for all of the rotatable members, and is arranged to strike the pin 43 secured to shaft 11 in the open position of the parts. Lug 71 is arranged to be struck by the stem 23 very shortly before shield 13.reache 's the closed position, so that the flipper 10 will be brought into intimate contact with the two electrodesas the two shields close together. It is obvious that counter weight 26 will cause the flipper 10 to engage the electrodes before stem 23 engages lug 71. It will be readily seen then .that 'stem 30 which is shown as very slender, is designed'to bend to allow shield 13 to reach its closed position. This slender wire construction for stem is also designed to facilitate the engagement of the flipper with both electrodes. In the open position of the parts (12", 13", 10") the shields and flipper are designed to lie in the blind spot of the projector, that is, in the shadow cast by the negative electrode holder 2. Y

The arrangement is such that when it is desired to start the arc, shaft 14 is rotated, which will first move the shields away from the arc'to about the position shown at 13, 12' in Fig. 2. At this point the stem 23 will strike lug 31 and rotate the flipper 10 away from its contact with the .two electrodes. This will immediately draw or cause an arc to form between the two electrodes. Continued rotation of the shaft will remove the shields and flipper to the approximate position shown in 'Fig. 2 at 10 and'13 and 12.

The shaft 14 may be rotated either by hand or automatically from the are light circuit. A handle 35 is shown tooperate the shaft by hand, while a solenoid 36, preferably in series withthe arc, is shown for operating it automatically. For this purpose the core 37 of the solenoid is connected to a bell' crank lever 38 which in turn isconnected to a sliding link 39. Said link is pivotally connected to an arm 40 secured to shaft l l, so that when the solenoid is energized, said shaft will be rotated. When the current is shut off the shields are quickly and automatically closed about the tips of the electrodes and the flipper'returned to its position in contact with electrodes by a spring 41 shown as secured between the fixed pin 42 and bell crank lever 38. A dashpot 43' also secured to said lever may stopping motor 5. the current to motor 5 would be shut off be provided to prevent the too sudden opening and closing of the shields and flipper. Connected with this mechanism so as to be operated thereby is a means for positively stopping the feeding of the electrodes when the flipper engages said electrode, so that jamming of the electrodes will be guarded against. In my preferred type of lamp one or both of the electrodes, 3, is rotated and fed within and through the holder 1 by mechanism located within the holder and actuated from the motor 5 in the control box through shaft 51. This mechanism is shown as comprising a large bevel gear 52 meshing with gear 61 on shaft 51 and rotatably mounted in holder 1. Gear 52 is provided with an extended hub 53 which supports the feed rollers 54 and 55, so that the rollers not only feed but also rotate the carbon.- The rollers are geared together by gears 56 and 57 and aredriven through an idler 58 from a toothed or star wheel 59 which strikes a detent 60 once every rota-' tion of gear 52. Detent 60 is movable to: ward and away from the path of the wheel 59, its position being automatically controlled to effect feeding at the desired rate. Between motor 5 and the bevel gears 62, 63 by means of which it drives shaft 51, is located a friction clutch 64, which will allow shaft 51 to stop without stopping the motor.

to move axially thereon, pressed by spring.

S against disk 64 rigidly secured. tosection 5 of said shaft 5?. On shaft 51 is mounted a star wheel 65 or similar device ,(see Fig. 3), and on rod 39 or other part of the mechanism operating flipper 10, is a pin 66 adapted to be struck by said wheel when flip-per 10 is closed. By this or similar means, both the rotation and feeding of either, or both of the electrodes are positively prevented without the necessity of While, in most cases,

when the arc is extinguished, it is "sometimes found advantageous to keep it running to exhaust the fumes in the drum thoroughly.

Furthermore it is found that, due to the high speed of motor 5, it will not stop for some tlme afterthe current is shut Ofl", so that without means to prevent feeding during this time, the flipper and electrodes might be damaged.

In accordance with the provisions of the 7 patent statutes, I have herein described the principle of operation of my invention, to-

gether with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it IS designed to ,claim and desire to secure by Letters Patent is 1. The combination with are light electrodes, of a light shield and a movable are striking member therefor and means responsive to changes in the energizing current for operating the shield and member.

2-. In an are light, the combination with the electrodes and electrode holders and an arc striking mechanism therefor, of a light shield for extinguishing the after glow com-- prising a pair of pivoted members adapted to normally inclose the electrode tips, means for removing said members from said tips and means brought into action by said removal for operatlng said are striking mechanism. 4

3. The combination with a pair of electrodes,

a movable are striking member, means for removing the shield on starting the are, and

a connection between said shleld and said member whereby the member is withdrawn to strike the are by the shield.

4. The combination with a pair of electrodes, of a removable light shield therefor, a movable are striking member, means for removing the shield on starting the arc, and a lost motion connection between said shield and said member whereby the member is withdrawn to strike the are after the withdrawal of the shield.

, 5. The combination with a pair of electrodes, of a removable light shield therefor, a movable arc striking member, means for closing the shield on shuttin off the arc current, and a connection etween said shield and said member whereby the closing of the shield forces the member into contact with the electrodes.

6. In a searchlight, having a pair of spaced electrodes, a movable member adapt ed to engage the are tips of both of said electrodes, shields for inclosing said tips, means for normally closing said shields; means for causing said shields to press said member into contact with both of said electrodes, and means controlled by the turning on of the arc current for opening said shields and for withdrawing said member from said electrodes.

7 In an are light, the combination with spaced electrodes, 0 a light shield adapted to inclose the are tips of said electrodes, means for moving said shield to its operative position, an are striking member pivoted near said electrodes, means for causin said member to engage at least one of sai of a removable light shield therefor,

.ing

tips, means for causing said shield to exert pressure on said member after said member has engaged one of said tips and before said shield has reached its operative position for causing said member to yield and move into contact with the other of said tips.

8.. In an are light, the combination with spaced electrodes, of a rod pivoted near said electrodes, a member on said rod for engaging the arc tips of said electrodes, an arc inclosing shield, means for moving said .shield into operative position, a lug connected with said rod adapted to be actuated bysaid shield to move said member into contact with said tips, said lug being so positioned as to cause said member to touch at least one of said tips before said shield reaches its operative position.

9. In a Searchlight, the combination with a drum, adapted to contain electrodes there-' in, of feeding mechanism for said electrodes, a movable member adapted to bridge the space between said electrodes, electrically operated means without said'drum for actuating said mechanism and said member and means controlled by the position of said member for locking said feeding mechanism against operation.

.10. In an are light, the combination with spaced electrode holders positioned in line and facing one another, each holder being adapted to support feeding mechanism for an electrode,a member located between said holders and adapted to touch both electrodes in one position, means for moving said member away from and toward said electrodes and means responsive to said last named movement for sto ping said mechanism.

11. In a search ight employing a pair of electrodes, means for inclosing the arc-tips of said electrodes, a movable member adjacent said are tips adapted to touch the same, means for moving said inclosing means, and said member into operative position, means for retarding the speed of said moving means and electromagnetic means in circuit with said electrodes for withdrawing said member to strike the arc and for removing said inclosing means to an inoperative position when the arc is struck.

12. In a Searchlight employing a pair of spaced electrodes, are tip inclosing means comprising a plurality of light shields pivoted adjacent said electrodes, counterweights for, moving said shields into closed position, an arc striking means also pivoted tact with said electrodes, additional means for pressing said shields and said are strikmeans into operative position, and means brought into action by the turning on of the arc current for moving said shields and said are striking means to inoperative positions.

13. In a Searchlight the combination with fixed electrode holders adapted to cause the electrodes to be fed therethrough, of a movable member adapted to bridge the space be tween said electrodes, and means for withdrawing said member into a position in Which it lies in the shadow cast by one of the holders. v

14:. The combination with are light electrode holders, of a light shield and a movable arc striking member therefor and means whereby both said shield and said members may be moved to a position in line with one of the electrode holders to prevent the casting of a separate shadow. a

15. In an are light, the combination with spaced electrodes, holders for the electrodes,

' and supports for said holders, of a shaft secured to one of said supports, a pair of sleeve members on said shaft, means for rotating said members in opposite directions, a pair of arc tip inclosing shields, and means for securing each of saidshields to one of said members.

16. An arc lamp for searchlights' comprising in combination, means for striking the are without causing relative movement of the arc electrodes, and means for moving said first named means into the shadow of a part of the lamp structure.

In testimony whereof I have afiixed my signature.

ELMER A. SPERRY.

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