US980221A - Electric switch. - Google Patents

Description

A. G. EASTWOOD.

ELEGTBIO SWITGH.

APPLICATION FILED arm. 21, um.

Patented Jan. 3, 1911.

a J! I b 12 6.19 A:

vl-rrlcsscs: E OR F 6 c 1 7 f I I IIIII//I/I WI bers of the UNITED STATES PATENT OFFICE.

ARTHUR C. EASTWOOD, OF CLEVELAND,

OHIO, ASSIGNOR TO THE ELECTRIC CONTROL- LEE AND MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A. CORPORATION OF OHIO.

ELECTRIC SWITC'H.

Specification of Letters Patent.

Patented Jan. 3, 1911.

Application filed September 27, 1906. Serial No. 836,421.

To all whom 'it may concern.

Be it known that I, ARTHUR C. EASTWOOD, a citizen of the United States, residing at @leveland, in the county of Cuyahoga and State of Ohio, have invented or discovered new and'useful Im rovements in Electric Switches, of which t e following is a specification.

My invention relates to improvements in electric switches, said improvements being particularly applicable to switches of the so-called power actuated type as distinguished from the ordinary types of electric switches which are opened and closed by hand.

The objects of my invention are to produce a power-actuated switch of great reliability in service, having a light and mechanically-simple movable contact member; having the contact members so arranged as to insure a clean contact of high carrying capacity; having the contacts so arranged with relation to the means for supportlng the switch that the switch must necessarily be so mounted that the interaction of the contacts may be readily inspected; having its parts so arranged that the contact memswitch may be removed and replaced with maximum ease; and having a blow-out magnet with its pole-pieces so arranged as not to interfere with the ready inspection and removal-of the switch contacts, together with certain other features of construction which will later be described in detail.

Power-actuated switches, as a general rule, are located at some distance from the operator and are not therefore under his direct observation. It is essential, therefore, that the switches be reliable in action and that each switch should open promptly in response to the operation of the operators switch or controller in deenergizing the actuating mechanism of the switch. To insure this prompt opening of the switch I have devoted a great deal of attention to the arrangement of the contacts with a view to preventing welding or sticking of the cooperating contacts.

In all power-actuated switches as constructed in the past, so far as I know, the contacts of the switch have been very inaccessible for inspection and repair, it being impossible, or at least very, diflicult, to observe the seating of the contacts one upon the other. With my the contacts are so action of the contacts can be readily observed. This feature is of im ortance in power-actuated switches, such, or instance, as are employed in the control ofelectrically-propelled trains. In such cases the failure of a switch to act properly may cause a serious wreck. With my improved construction, even when the switches are mounted in the customary manner under the cars, the contacts will be accessible for inspection and are so arranged that they may be removed and replaced with minimum inconvenience and loss of time.

Referring now to the accompanying draw- .ings, Figurel'is a top plan view; Fig. 2, a front elevation, portionsbeing broken away and the pole piece 9' being omitted; Fig. 3, a side elevation of one of my improved switches; Fig. 4, a cross-section through the lever F and its adjuncts on a line throu h improved construction ,the screw f Fig. 5, a cross-section of t e lever C and the wear-block 0 through the screwc; and Fig. 6, a detail of a plat and the pin 9 Iifthe drawings I have in each case shown part of the an electro-magnet for actuating the switch.

It will beevident, however, that the electromagnet, might be replaced with an aircyllnder or other motive device without in any way departing from the spirit of my invention.

In the figures, A is a slab of slate or other insulating material adapted to be supported in a vertical position.- B is the actuating electro-magnet havin feet 6 b 6 by means of which, it is attache .to the slab or base A. The electro=magnet B is provided with a magnetizing coil 6 wound upon a tube of non-magnetic material 6 The upper end of the tube 21 is closed by the plug b of magnetic material. A plunger 7), of magnetic material, works vertically in the bore of the tube 6 The lunger b is provided with a tongue I) which extends through a slot in the plug 72* and is attached by the pivot G to the movable contact arm G of the switch. Vhen the electro-magnet is energized theplunger b is attracted toward the lower face of the plug 7), and rises vertically, thus actuating the switch arm to close the switch. When the electro-magnet is deenergized the plunger drops by gravity and opens .the swltch. The switch arm O is arranged that the inter lator, b

5 wires of the circuit controlled by the switch may be attached. A shunt or jumper C of flexible copper ribbon is screwed at one end to the arm C and at the other end to the yoke 6 This shunt serves to carry current 1 around the pin 0 and prevents heating of the bearings.

The yoke b is provided with an upwardly extending bracket 6 to which is attached a block or piate of fiber or other good insuy means of bolts 6 A metallic base-casting D is attached to the insulating plate I) by bolts d (Z and is provided with two lu d and d the inner faces of which are finished to receive the contact brush E,

20 whichiis made of thin strips of cop er or bronze riveted or sweated together to orm a brush of the desired thickness. The brush is mounted in the pocket between the brackets d and d with its length at an angle to the 25 switch arm C, this angle being preferably about 45 when the arm C assumes the horizontal or closed position. The end of the brush E is beveled so that the free end of each lamination makes contact with the upper face of the arm C when the switch closes, and the otheer end of the brush E is similarly beveled so that when one end of the brush becomes worn the brush may be reversed end for' end. This construction also 35 permits of building up the brush of thin strips, all of the same ngth. A set screw (1 in the bracket d bearing upon a gib e clamps the brush in place.

A metallic arm F is pivoted on a pin d attached to the base I), and is cored out so as to clear the brush E. The outer free end of the arm F is provided with a dove-tail slot f extending transversely across its under face and a carbon block f is slipped into this slot and held in place against transyerse motion by a U-shaped piece P which is slipped over the end of the arm so as to embrace the edges of the block f and is held in place by a screw 7. The movable switch armC is provided at its free end with a renewable L-shaped contact piece a which is ada ted to make contact with the under face 0 the carbon block 7" when the switch closes, and is held in place by a screw 0.

The arm F is held on the pin d by a washer d and a cotter pin d and is provided with an extension j" to which is attached one end of a tension spring f. The spring f is insulated from the arm F by an insulating tube or spool f which covers the pin f on the extension 7. The other end of 4 the spring is attached to a lug (i extending from the casting D. Motion, imparted to the arm F by the spring f, is limited by the to the casting stop i on the extension f. which stop engages the lug (1 in which position the face of the carbon block f extends considerably below the face of the brush E. When the switch closes through the energizing of the electro-magnet B, the plunger raises the arm C. The contact piece 0" first makes contact with the carbon block f then the arm F is forced up against the action of the spring f; and the arm G comes into contact with the brush E with a wiping motion due to the flexible character of the brush E and its angularity with the arm C.

\Vhenthe electro-magnet B is deenergized, the plunger drops by ravity, the speed of opening of the switch being assisted by the action of the spring f also. In opening, the arm C first opens circuit with the brush E, the circuit being finally opened between the carbon block f and the contact iece 0 All of the arcing is, therefore, con ed to these parts which may be cheaply and readily renewed. To cause the instant rupture of the are which is formed when the circuit is opened at the contacts of the switch, I provide a blow-out ma net G. This ma et is provided with a ho low core 9 whic sli s over a stud g attached to the base casting The magnetizing winding consists of acoil of flat copper ribbon H, the inner end of which is riveted in the slot 3 of the core 9 The outer end of the win ing is rovided with a terminal g, to which one of t e circuit wires, controlled by the switch, may be attached, by means of the screws g.

The winding of the blow-out magnet is electrically connected to the core 9 which in turn is electrically connected to the base casting D by the stud 9 The magnet is provided with pole pieces 9 and g, the inner face of each pole piece being covered .by an insulating plate g". The pole pieces whose lower edges are indicated by the dotted line 9 are so located as to embrace between them the contacts of the switch so that any arcing which takes place at the contacts is acted upon by the magnetic field. When the switch is closed 'current may enter at the terminal pass through the successive layers of winding of the blow-0ut magnet G, (the successive layers being insulated from each other by layers of mica or asbestos) to the core 9 thence by the stud g D and through the brush E and the carbon block f to the switch arm C, thence through the shunt C to the yoke casting b, current leaving the switch through the terminal 5 It will be understood that my improved switch is arranged to be mounted as shown in Fig. 3, this figure being a front elevation. Looking at this figure then, the arts of the switch are located as they would ice. It will be seen that by simply removing the nut g, the pole piece 9 may be be in servslipped off. All of the contacts of the switch are then in full view and their action mayreadil be tested by raising the switch arm G. I it IS desired or necessary the magnetizmg coll may be removed from the stud g it being simply drawn toward the observer.

By loosening the set screw d the contact brush E may be removed edgewise toward the observer. By loosening the-single screw which clamps it in place the renewable contact piece .0 at the end of the arm C, may be readily removed; likewise, by removing one screw P, the carbon block 1 may be slipped out in a direction toward the observer. By removing the cotter pin (Z which holds it in place on the stud (l and by unhooking the spring F, the entire arm F may i be removed. It must be evident also that the movable switch arm may be made light in weight and is of simple construction.

I do not restrict my invention to the details shown and described as they and their combination may be variously modified without departing from the spirit thereof.

I claim- 1. In an electric switch, the combination of one switch member comprising a conducting base, a stiff metallic arm, pivoted on said base and carrying near its free extremity a renewable arcing tip, there being an aperture in said switch arm between its pivot and its free end, a contact brush, clamped to said conducting base and having its end projecting through the said aperture, and a second contact member comprising a swinging main contact arm, having at its free extremity a renewable arcing tip adapted to cooperate with the arcing tip at the extremity of the first mentioned pivoted arm and having between said arcing tip and its axis a contact face adapted to cooperate with the end face of said contact brush.

2. In an electric switch, a relatively stationary contact brush having a contact face,

3. In combination, a frame, an electromagnetic winding carried thereby, a plunger adapted to be actuated by said winding, a pivoted contact arm pivotally connected to said frame, a contact support mounted upon said frame, a yielding contact carried by said support and arranged to engage said contact arm at a point intermediate of its ends, a contact holder pivotally mounted upon said support, a carbon contact carried by said support and arranged to engage the free end of said arm, and a spring exerting a yielding force upon said contact holder when said carbon contact is engaged by said arm.

i 4. In an electric switch, the combination with a supporting frame, of a switch member pivoted thereto, a solenoid mounted in said frame and having a plunger connected to said switch member, and a stationary laminated contact mounted on said frame and arranged to engage said switch member at a point contiguous to its connection with the plunger of said solenoid, said contact being obliquely disposed to said switch member.

5. In combination, a magnet frame, an

electro-magnetic winding carried thereby,

a plunger adapted to be operated by said winding, a contact member pivoted upon said frame and mechanically connected to said plunger, a contact support mounted upon said frame, a laminated brush carried thereby and inclined from its point of attachment to the point of connection between said plunger and said member.

6. In combination, a magnet frame, an electro-magnetic winding carried thereby, a plunger adapted to be operated by said winding, a contact member pivoted upon said frame and mechanically connected to said plunger, an insulating base mounted upon the frame, a contact support carried thereby, and a laminated brush carried by said support and inclined from its point of attachment toward a point contiguous to the point of connection between said member and said plunger.

Signed at Cleveland, Ohio, this-24cth day of September, 1906.

ARTHUR C. EASTWOOD.

Witnesses:

C. W. CoMsTooK, S. L. MEIKLE.

Images