US1655837A - Subway transformer - Google Patents

Description

Jan. 10, 1928.

S. HORELICK SUBWAY TRANSFORMER Filed Dec. 17, 1925 Patented Jan. 19, 1928.

UNITED srnrss rarest -SAMUEL HORELICK, OF PITTSBURGH, PEHNSYLVANIA, ASSIGNOR TO PITTSBURGH TRANSFORMER COMPANY, 1%. CQIREGEATION OF PENNSYLVANIA.

SUBW AY TRANSFORMER.

Application filed December 17, 1925. Serial No. 75,928. V

This invention relates to a chambered ap paratus having provision for controlling the chamber in accordance with various'con ditions. and relates more particularly to electrical apparatus wherein it is desired to permit a chamber thereof to have controlled communication with a desired space;

In electrical apparatus, such as a subway transformer, it is desired to permit the transformer interior to have communication with the atmosphere or another equivalent enlarged volume for the purpose of allowing the transformer to breathe, and thereby to discharge moisture which might be present in the insulating oil usually disposed in the chamber. This type of electrical apparatus is placed usually in a pit below a normal level, such as a street, from which water may flow with the possibility of submerging the apparatus. It is of the utmost importance thatthis Water should not flow into the apparatus.

It is an object of my invention to provide means which will permit the interior of the apparatus to have communication with a desired space, and which communication will be controlled automatically in accordance with certain relative conditions existing between said space and chamber. A further object is to provide an improved valve and float arrangement which will control access to the interior of the apparatus.

Other objects will appear from the follow ing description of the accompanying draw ings, in whicl Fig. 1 is a sectional view of an enlarged chamber within which a transformer is disposed.

Fig. 2 is an enlarged fragmentary partial sectional view of the valve mechanism.

In the illustrative embodiment of my invention I have shown a desired space in the form of an enlarged chamber 1 formed preferably by suitable walls 2 and to which access may be had through a suitable man hole 3. This manhole is usually flush with the street level, from which water may flow into the chamber 1. Disposed within the chamber is a piece of electrical apparatus, specifically a subway transformer 4, having a cover 5 through which air may pass into the transformer interior as by an inverted U-shaped pipe 6. The free end of pipe 6 is provided with a suitable valve housing 7 and a movable valve member 8, which is made of'suchmaterial and so constructed that no deterioration thereof may take place or foreign material become lodged therein in case the valve remains inoperative for a great length of time. The parts are provided with suitable cooperating seat surfaces so that under no conditions will the valve be held open when the abnormal exterior condition prevails. To insure positive closing of valve 8 an arm 9 pivoted thereto carries a float- 10 which extends a considerable distance below the valve 7 to insure that considerable leverage will be .nb tained during closing movements,

As long as chamber 1 does not accumulate water to the extent of engaging the float 10, chamber 1 will communicate with the transformer interior, thereby permitting the breathing action which is highly beneficial to certain types of electrical apparatus of the type disclosed. However, upon accumulation of water in the chamber 1 to the extent that it would be detrimental, float 10 will be forced upwardly to close the valve, thereby preventing communication with the transformer interior and accordingly pre venting flow of water into the same. 0

If the valve should be closed due to action on the float by water which might completely submerge the apparatus and should an abnormal pressure condition arise within the apparatus to such a point that the internal pressure would be greater than the holding force of the float, the valve would be forced open to relieve this abnormal internal pressure condition. It is to be noted, however, that the surrounding water could not have access to the interior of the apparatus when the valve was relieving the abnormal internal pressure for the internal pressure will at all times be great enough to more than overbalance the static pressure of the surroundingwater. Moreover, the valve is so arranged that it could open and close very quickly and thereby further reduce the possibility of water or other foreign matter gaining access with the interior.

I claim:

1. In combination with an electrical apparatus having a casing providing an interior chamber, and means forming an 8X- terior chamber, of means normally permitting atmospheric communication between said chambers and means adapted to inter rupt said communication automatically upon the existence of an abnormal liquid condition in said exterior chamber.

2. In combination with an electrical apparatus having a chambered casing disposable in a pit means permitting communication between the pit and casing chamber, and means for automatically preventing said communication when liquid accumulates in said pit to a predetermined level.

3; In combination with a transformer immersed in oil contained within a casing forming an interior chamber disposed in a pit forming an exterior chamber, a breather means for said casing normally permitting the escape of moisture within said casing, liberated from the oil by the heating of the oil during the operation of the transformer and means for automatically sealing said breather means so as to prevent water accumulations within said pit from entering said casing when said water accumulations rise to a predetermined level.

4. In combination with a transformer immersed in oil contained within a-casing forming an interior chamber disposed in a pit forming an exterior chamber, a breather pipe for said casing normally permitting the escape of moisture within said casing liber- SAMUEL :HORELICK.

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