US311957A - Eeick k - Google Patents

Description

UNITED STATES i n rcnar UFFICEQ GEORGE A. CARDVELL, OF BROOKLYN, N. Y., ASSIGNOR TO HIMSELF, FRED- ERICK K. FITCH, OE NEYV YORK, N.

NEWARK, N. J.

TELEGRAPHIC AND TEL PHD:

SPECIFICATION fcrming part of Y., AND JOSEPH T. MURRAY, OE

EC i" PRD'TECTOR.

Application tiled Fclnnaiy 1-1, 1884. (No model.)

To aZZ whom it may concern:

Be it known that I, GEORGE A. CARDWELL, of the city of Brooklyn, county of Kings, and State of New York, have invented certain new 5 and useful Improvements in Telegraphic and Telephonic Instrument Protectors; and I do hereby declare the following to be a full, clear, and exact description of the invention.

This invention has for its object the provision and maintenance during its necessity of means for protecting telegraphic, telephonic, and other electrical instruments against ini u ry arising from the introduction into their circuits of abnormallypowerful currents oteleetricity. My invention consists of an electrical apparatus designed to be placed in circuit with the IlllStlllll'lBlltS to he protcetel, and of such nature and construction as not to be affected or energized by the normal operating-current; but when a powertul current is acciden ally introducedas,for instance, by the line-wires coming in contact with wires conducting currents tor elec. ric lightingthe apparatus will be so operated as to immediately break the circnitof the workinginstrumentsand ground the dangerous current. The apparatus is also so arranged that it will automatically restore the circuit to its normal condition when the dangerous current has been eliminated.

The drawing represents a top view of the apparatus,part-lyinsection,showingtheconstruction and arrangement ofthe several component parts. Upon an ordinary base, A, are secured two electro-magnets, N and M, with their arma- 5 tures it and m hinged, respectively, atrand r.

a and m are the cores of the magnets, and n and m" are the outside extensions of the iron core. The armatures m and n have each at their inner ends a short piece of metal, or m. separated by strip of insulating material 00 rt from the main piece of the armature. The armature a is provided with the back contact point, 0, and the armature m with the back contact-points, c and e. 0 and c are kept in 4.5 contact with the ends of the adjustingscrews t and t by the retractive force ot the springs s s, which are attached to the arm atures and to adjusting-screws F F, working in suitable pieces secured to the base. Thesescrews allow of the graduation of the strength of the springs according to the strength of the current normally passing hrough the line. The springs must be ol'such strength that the armaturcs will not be drawn toward the magnets except when energized by currents much more powerful than the workingcurrcnt of the line. The adjusting-screws t t workin angle-pieces secured to the base-plate, the same pieces also carrying binding-posts T T, to which are attached the \VlitS t 1, connecting with the instruments which it is desired to protect. Betw een the two electro-magnets a metal plate, E, is secured, having a bindingpost, G, directly connected with ground. In the upper part of the plate E three screws, 0 (Z work. These screws are respectively opposite the contact points 0 on the lower side of the insulated end a of the armature n, the contactpoint i? on the spring is, and the contact-point d on the lower side of the armature m.

.v'hen the instrument is not-in use, or the currentis normal,the contactpoint i is almost, but not quite, in contact with the platinum point ot'screw t", the contact-point 0 is a little farther separated trom the screw 0", and-tl1e contactpoint (l is still more widely separated. Screws are used. so that these points may be kept in correct adjustment.

The wire used in winding the magnet M is in two sectionsiinc wire \V and coarse wire to. The line wire wound in the usual manner next to the sol'tiron core, and is for the purpose ot'cnergizing the magnet more quickly than it the magnet were composed of coarse wire only. "he other section, which is not continuous with the first, but composes a part of the same circrit, is wound with very coarse wire. Both these coils or part of a coil of electro-magnet ll are in the normal circuit. The instrument or instruments to be protected are inserted between themthat is, they are each connected to the instruments in such a way that the normal current passes through one part of this double coil, then through the illstruments. and tinally through the other part of the double coil. \Vhen an abnormal current enters the line, it for an instant pursues the same course; but almost immediately the fine-wire part of the coil is cut out and the current passes entirely throu h the large wire. To the bindingposts L L are attached the line-wires Z Z. The core of magnet N is surrornded with coarse wire only, wound in the usual manner. It is brought into use only when the abnormal current enters at L. The contacts at t and c are made by the screw and a platinum contact-point on m and two opposite points attached to a small springplate, K, secured to the block 76, which is insulated. At 0 the points are normally in contact, while at 1' they are slightly separated.

The connections are as follows: One of the line-wires enters the binding-post L. This binding-post is connected to one end of the coil of the electromagnet N. The other end of this coil is connected with the insulated end a" of the armature a. This in turn is connected by a covered wire with the insulated end on of armature m. The line-wire entering at binding-post L is connected with the outside of the coarse-wire coil of electro-n'iagnet M. The other end of this coil is attached to the armature in. A connection is made between the binding-post L and the inner end of the fine-wire coil of M. The outer end of the fine-wire coil is connected with the armature a. The binding-post G connects with ground. The instruments are connected by means of binding-posts T and T. The normal circuit is beginning at L through the coarse wire of magnet M to armature at through contactc to T, thence through the instrument or instruments to be protected to T, and on through contact a, armature a, to the fine wire of magnet M, thence to line through post L. Should a powerful current gain access to the line, and enter the apparatus at L, magnet M is instantaneously energized. Armature m is drawn down, the contact at c is broken, cutting out line-instrument, the contact at d is made, and ground-circuit completed. As soon as circuit is closed the coarse wire of M takes the whole abnormal charge direct to earth by way ofm d (I G, &c. \Vhen the line is relieved, m is drawn back by the spring 8, contact 0 is closed, and the line is again in normal condition. Should the heavy current enter the apparatus from the opposite direction at L, it energizes the magnet M by entering the tinewire section by means of the wire Z), and operates the armature m, as before. The contact at c is broken, the contact at i on the spring K is made. The breaking of the contact 0 cuts out the magnet M, demagnetizing it, and of course releases the armature m, which in receding closes the contact 0 on the spring K before the contact i is broken, forming a temporary ground circuit through magnet X, insulated end a of ar1nature a, contact at 0, between spring K and insulated end at of armature at, contact at '17, between spring K and screw 1', attached to ground-plate E, and grouml-plate E to ground. The current now passing through N energizes it, and draws down the armature a and forms a direct ground-circuit through a, contact 0, and ground-plate E.

By the use oi my device the entire abnormal current is diverted to ground. In most of the instrnmentsin use the current divides, a portion going over the line, though the larger part goes to ground.

Having now fully described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In an electromagnetic device for protecting electrical instruments from abnormal currents, two electro-magnets, one wound with coarse wire only and not normally in circuit, the other wound with two separate non-coir tinuous superposed coils, one ol'iii'ie'wire and the other of coarse wire, but both coils in the same normal circuit, the instruments to be protected being interposed between the coils or parts of a coil, substantially as shown and described.

2. In an electromagnetic device for protecting electrical instruments from abnormal cnrrents, conducting armatures of two electromagnets having insulated ends electrically comiccted but mechanically independent, substantially as shown and described.

3. In an electromagnetic device for theprotcction of electrical. instruments from abnormal currents,an insulated independentspring, K, having two contact-points, one, 0, normally in contact with the insulated portion m of an armature, m, of an electro-magnet in the normal circuit, while the other, 2, is separated from the ground contactpoint by aslight interval, substantially as shown and described.

4. In an electromagnetic apparatus for pro tecting electrical instrumein's from abnormal currents, the combination of clectro-nn'ignet N, electro-magnet M, with two coils, one of fine and the other of coarse wire, the armatnres a and m, having insulated metallic ends a and m, retracting springs s s, spring K, groi'uid-plate In, and contact-points c, c, c, 47, and'd, substantially as shown and described.

In witness whereof I have hereunto set my hand.

GEORGE A. CARDW'ELL.

\Vitnesses:

Gno. II. Soxxnnonrv, Farm; Hiininsos'.

TOO

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