US1138170A - Transformer-protector. - Google Patents

Description

Patented May 4, 1915.

0. B. ALLGOOD.

TRANSFORMER PROTECTOR.

APPLICATION mm MAR. 11, 1913.

' UNITED STATES PATENT 5 OFFICE.

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To all whom it may concern: I

Be it known that I, Osoaa B. Anmoon, a

citizen of the United. States, residing [at Blocton, in the county of Bibb and State of Alabama, have invented certain new and useful Improvements in Transformer-Protectors, of which the following is a specification. v

This invention relates to improvements in transformer protectors and has for its ob ect to provide means whereby a three-phase motor may be prevented from running single phase, thus removing all danger of the transormers being destroyed by an overload.

In a three-phase" motor circuit fuses are often set at 100 percent. overload and are ver little protection to the-transformers an motor- When a 'fuse is burnt out two transformers are cut off and the motor continues to run sin le phase and the load is carried by one 0% the transformers. The

' motor and transformer will both develo 100 per cent; or more overload, which wil soon spoil the transformer and possibly-injure the motor.

My invention. revents the motor from running single p use by causing the circuit' breaker to open the primary circuit whenever a fuse is out.

A more specific object of the invention resides in the provision of .a plurality of novelly formed solenoids, connected in parallel with the fuses of a three-phase, circuit and adapted to operate when one of the fuses is burned out to open the primary circuit.

With these and other objects in view, as will become more apparent as the description proceeds, the invention consists in certain novel features of construction, combi nation, and arrangement of parts as will be herelnafter descri ed and clalme For a complete understanding of m invention, reference is to be had to the 0 lowing descrigtion and accompanying draw ingg, in w 10h,

, igure 1 is a transverse sectional view partly in elevation through mdy invention, showm the same positions switch fiioard under a circuit breaker and connected-in parallel with-the fuses. Fig. 2 is a top planview of my invention, and, Fig. 8 is a transverse sectional view through upon the.

the solenoid casing, showing my invention in elevation.

Referring in detail to the drawings by numerals, 1 designates a switch board, to

. which is secured a circuit breaker, generally desi nated 2, and having the operating lever 3, w ich is pivotally secured at its lower end.

A slotted bar 4 is connected at its forward end the lever 3 by means of the fastener 6 and is connected at its rear end to an oil switch, not shown.

A togglefi operates to lock the bar 4 against movement until broken by the mem-' ber 7. -When the toggle is broken, the bar 4 moves upwardly, actuating the oil switch to break the rimary circuit through the transformer. make no claim to the circuit breaker and oil switch but merely show and describe them to illustrate the application of my invention.

' In the embodiment of my invention, I provide a casing 8, havin a top wall 9, said casing being seen to the switch board 1 directly under the circuit breaker e nte mar 4.1915.

by means of the fasteners 10. The casing supports three solenoids, each comprising a preferably brass tube 11, closed at its lower end and provided adjacent its upper end with the flange 12. The tubes roject through openings in the bottom of tii m and are supported by means of the co lars 13. A coil 14. of asbestos-covered wire encircles that portion of each tube which extends within the casing 8. It will e cas'-- I be noted that the flange 12 and collar 13 cooperate with the tube to form a sort of spool upon which the wire is wound. Lon itudinally bored tubular members 15 close t e upperends of the tubes and are threaded into engagement with nuts 16, which are mounte 17 having-enlarged heads extend through the tubii ar mem ers 15 and project beyond the inn ends of the same. slidable within the tubes 11.

A bar 19 is ivoted between thebrackets 20 by means 0 a suitable fastener passing through said brackets and rojection 21 formed 11 on said bar. The ar is formed Cores 18 are in the cover 9 of the casing. Pins with a p uralityof lateral projections 22, which are disposed in the path of the pins 17. The central projection 22.is formed with a longitudmally extending portion 23, to

which is connected a rod 24, said rod being connected at its upper end to the bar 7.

The coils 14 are connected by the wires 25 in parallel with the respective fuses 26, said fuses being in the three-phase line 27, which leads to the motor, not shown.

When the fuses are .intact a very small quantity of current will pass. through the coils 14, but when a fuse is burnt out, the corresponding coil will be energized and raise the corresponding core 18, which will strike one of the pins 15. This pin will be raised and cause an upward movement of the rod 24, which motion will be transmitted to the member 7 so as to break the toggle 6 and open the primary circuit.

It will be seen from the foregoing description in connection with the accompanying drawings, that I have provided a transformer protector which will protect the transformers in a three-phase circuit from being destroyed by an overload heating the oil, which protects the motor by preventing it from running single phase under an overload, and which, when a fuse is out, indicates the fact should an attempt be made to start the motor.

It is to be understood that I do not wish to be limited to that embodiment of my invention shown herein, but wish to protect the idea of connecting a similar device in parallel with the fuse of a three-phase motor circuit.

Having thus described my invention, what I claim is A tripping device comprising a rectangular casing, a plurality of tubes extending through the bottom of the casing at right angles thereto and having their lower ends closed, the upper ends of the tubes being flanged and spaced from the top of the casing on the interior thereof, collars secured to said tube within the casing and engaging the bottom of said casing whereby the tubes are supported, nuts fixed in the top of the casing, longitudinally bored members threaded through said nuts and projecting into the upper ends of the tubes, a headed pin slidable through each of said bored members, a longitudinally movable core carried within each of said tubes, a coil of wire surrounding the upper end of each tube, whereby a plurality of solenoids are formed, a bar pivoted intermediate its ends to the top of the casing, projections formed upon said bar and extending over the headed pin, and a rod connected at its lower end to one of said projections and adapted to be connected at its upper end to a circuit breaker to trip the latter.

In testimon whereof I affix my signature in presence 0 two witnesses.

OSCAR B. ALLGOOD.

Witnesses:

QULN' W. STUART, A. A Wms'roN.

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