US551054A - Electric controller - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1.

s. H. SHORT. 5 ELECTRIC CONTROLLER.

No. 551,054. Patented Dec. 10, 1895.

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SIDNEY H. SHORT, OF CLEVELAND, OHIO.

ELECTRIC CONTROLLER.

SPECIFICATION forming part of Letters Patent No. 551,054, dated December 10, 1895.

Application filed August 2'7, 1895. Serial No. 560,688. (No model.)

To all whom it may concern.-

Be it known that I, SIDNEY H. SHORT, of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Electric Controllers; and I do hereby declare the following to be a ful1,clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in electric controllers, and has for its object the disruption and suppression of the arcs formed between the adjustable and stationary contacts of the switches employed in connection with the motor and resistances associated therewith; and the invention consists in certain features of construction and combinations of parts, as will be hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a view in cross-section of one embodiment of my invention. Fig. 2 is a plan view. Figs. 3 and a are detached views of the slotted pole-piece and contactfingers, and Figs. 5, (3, 7, and 8 are modifications.

A represents the cast-iron back of a controller switch-stand, and B the sheet-metal casing, which parts may be of any suitable material and constructed and connected together in any approved manner to form a cas ing for the controller.

C is the controller-shaft suitably journaled at its ends and provided at one end with a detachable handle a. Upon shaft 0 are placed the sleeves D D D which may be made of east-iron or other magnetic material, and which are insulated from the shaft by means of the insulating-sleeves h and insulated from each other by the insulatingwashers c. Any desired number of sleeves may be thus mounted upon the shaft, so as to turn therewith. Each sleeve is provided with segmental contacts E E, which are preferably cast integral with its tubular portion. The periphery e of each segmental contact is turned smooth and true, so as to form a smooth and good wearing-surface and contact with the yielding contact-fingers F F, which are mounted as follows:

G is a strip of wood, to the rear corner of which is fastened an angle-iron f, upon which are seated and secured the brackets G. To the upper ends of each one of these brackets is pivoted a finger F, the outer or free end of which is shaped to fit the wearing-surface of the segmental contacts E E. The opposite end of the finger is provided with a projection 71, with which engages the end of an adjustable screw-stop H. A spring H serves to press the finger yieldingly against the segmental contact on the shaft.

I is an electromagnet consisting of a bar of soft iron, on which is wound comparatively few coils of conductor 1, which is preferably of low resistance and is included in the main circuit of the motor. The polar extension I of the magnet is so formed and arranged as to be in close proximity to the free ends of the contact-fingers F.

I have not shown the circuit connections of the contact-fingers and segmental contacts, because they may be such as are ordinarily employed and constitute no part of my invention.

The operation of the device is as follows: Current circulating through the helix of the electromagnet I inagnetizes its pole-piece I and causes the lines of force to flow across the air-gap g between the pole and segmental contact, through the latter and its sleeve to and throughthe projection g on the back A of the casing, and through the latter to the core of the magnet,which is mounted thereon. Thus it will be observed that a complete magnetic circuit (shown by dotted lines) is formed, which includes the sleeves with their segmental contacts. The strong magnetic field which is formed between the pole of the magnet and the rotating contact will operate to disrupt and effectually suppress any are that would otherwise form between the finger F and the segmental contact, as the circuit is broken by their separation, owing to the fact that the lines of force are concentrated within and fill the space between the segmental contact and the free end of the finger. Further, as the air-gap separating the magnet-pole and movable contact is narrow and offers comparatively little resistance to the passage of the lines of force across it, I am enabled to produce a magnetic field of ample strength to suppress arcing by the employment of a magnet having a helix composed of few turns of low-resistance conductor, and hence requiring the minimum expenditure of energy.

Figs. 3 and i are detached views of the magnet, which is slotted at g for the reception of the free ends of the contact-fingers in order that the lines of force may be concentrated within the space between the contact-finger and the movable contacts. These slots may extend the entire width of the pole, as shown in Fig. 3, or only partly through it, as represented in Fig. 4c.

In Fig. 5 the pole of the magnet is arranged in close proximity to the back of the controller-stand, so that the magnetic circuit will be completed through the magnet-core, back A, and segmental contact.

Fig. 0 represents a U-shaped magnet, the limbs of which are wound with a conductor included in the circuit of the motor and the pole-pieces of which are arranged in close proximity to the segmental contacts. The pole-pieces may be slotted for the reception of the free ends of the yielding fingers and thereby insu re the production and concentration of a strong magnetic field within the space formed between the coi'itact-finger and the segmental contact at the instant they are separated.

Fig. 7 is anothermodification, in which the magnet is formed by a helix J, being wound on the pole-piece K, formed on the back of the controller-casing. An extension L is bolted to or cast integral with the back A of the easing, thus insuring a complete magnetic circuit, as indicated in dotted lines.

Fig. 8 represents another modificatiomin which two polar projections K are formed in the back of the casing by being cast thereon or applied in any manner desired. On one or both of these pole-pieces is wound a helix J, whereby a complete magnetic circuit is formed, as is indicated in dotted lines.

As it is obvious that my invention is susceptible of being embodied in many forms of construction other than those shown and described, I would have it understood that I do not limit myself to the particular construction and arrangement of parts shown and described; but,

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

1. The combination with a series of iron sleeves provided with segmental contacts, of an electro-magnet having its pole arranged in close proximity to the path of travel of said contacts, and a series of contact fingers the free ends of which are arranged to engage said segmental contacts, substantially as set forth.

2. In a controller, the combination with contacts actuated by the controller shaft, and an electro-magnet having a slotted pole-piece arranged in close proximity to said rotary contacts, of contact fingers the free ends of which are located within the slots in the pole piece of the magnet, substantiallyas set forth.

3. In an electric controller, the combination with rotary contacts of magnetic material and a series of contact fingers, of an electric magnet having a series of pole pieces terminating in proximity to said contacts, each pole piece being slotted for the reception of the free end of a contact finger.

4. In an electric controller, the combination with a casing having an iron base, of a shaft mounted in said casing, a series of sleeves of magnetic material, mounted on and insulated from said shaft, each sleeve having arms of magnetic material, an enlargement on the base, in close proximity to which one arm on each sleeve is disposed, a series of contact fingers adapted to engage contact arms on said sleeves, and an electro magnet secured to said magnetic base and having pole pieces terminating in close proximity to said contact arms and contact fingers, whereby a magnetic circuit will be completed from said pole pieces to and through the contact arms and magnetic sleeve to the magnetic base and the magnet core, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

SIDNEY II. SHORT.

\Vitnesses:

M. A. KENSINGER, R. T. BONE.

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