US1560308A - Electrical switch - Google Patents

Description

Nov.'3, 1925. 1,560,308

c. L. PERRY ELECTRICAL. SWITCH Filed OGC. 19. 1923 r/0- I I [nVenLor:

Char/es L. Perry,

Patented Nov. 3, 1925.

UNITED STATESy CHARLES L. PERRY, OF SCEEIECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC!! COMPANY, A CORPORATION 0F NEW YORK.

PATENT OFFICE.

RIC

ELEGIRICAL SWITCH.

l Application :Bled October 19, 1923. Serial No. 669,557.

To all whom it may concern:

Be it known that I, Cinnmis L. PERRY, a citizen of the United States, residing at Schenectady, in the county of Schenectad State of New York, have invented certain new and useful Improvements in Electrical Switches, of which the following is a specification.

My invention relates to electrical switches, and particularly to those which are adapted to interrupt a circuit in which a large current is flowing. It has for one of its objects to provide in such a switch an iinproved form of contact and connector which will be strong, simple and ellicient in operation.

In electrical switches of the contacter type it is customary to build the switch mechanism of cast-iron or like material, and to provide low resistance contacts and connectors to the current passing through the switch. eretofore these connectors have been secured to the contacts by bolts or similar means. When the`connectors are connected in this manner they frequently work loose, and often the surfaces of the connected because of unevenness prevent a g contact being made between the arts. These conditions create resistance between the parts which will cause them to unnecearil heat up and thereby consume power whicli would otherwise through the switch. This heating also cause the flexible conductor to become brittle and thus its lexibili In of small current capacity y e heating of the contact and consequent lo of power will be negligible, but in switch where large current is carried the heating and loss of power due to poor contact between the parts is often considerable. To reduce this heating it is n to reduce the resistance of the arts and the contact resistance betweentepartstoaminimum. Ipropose to overcome this heating providing a flexible connector or shunt ha its end consolidated into a solid and rigi mass of suitable shape to form the contact. Such a will eliminate the contact resistance heretofore present between the conq nectorandthecontaet.

When switches of the above type are used to control circuits where a large current has to be interrupted, it is customary to provide a plurality of contacts which open 1n succession for the purpose of breaking the arc, which is drawn as the contacts open. In my improved switch, kI employ three contacts, which I shall refer to hereinafter as a main contact, an intermediate contact and an arcing contact, all of which make wiping contact in closing, are mounted on the same movable member, and o n in the reverse order of their closing. he main contact is made comparatively heavy so that it can carry the current continuously and the other contacts are made small, but of suiiicient size to carry the. current momentarily. The intermediate and arcing contacts, being small, are cheap, easy to replace, and protect the heavy contact from burning and also prevent it from freezing' in the closed position. The small contacts open to a greater distance than themain or heavy contact and thereby tend to break the arc y pulling it out to a length at which the voltage will not maintain it. The last contact to open is usually provided with a magnetic blowout which assists in disrupting the arc. To insure that the contacts open in the proper order and that the contact adjacent the magnetic blowout, or arcing contact is last to open, it is necessary to provide means which will open the other contacts before the arcing contacts open. To this end, the intermediate Contact is pivotally mounted on the movable member, spring pressed toward its closing position, and is provided with a stop for limiting its movement toward the closing pofsition atlied itsoninin into time tween flint atpivhi thepiiiain and arcing contacts open and close. It is also desirable that the contacts, and especially the intermediate contact be adjustable, so that wear of the parts and burning of the contact can be compensated for. In ordertoaccomplish this, I make the stop for the intermediate contact adjustable so that this contact can beset in different positions as conditions reuil-e.

For a better understanding of my invention; Fig. 2 is a sectional view of the contact shown in Fig. 1; Fig. 3 is a side elevation of an electrical switch of the contactor type; and Figs. 4 and 5 are views'showing one manner of mounting the main contact.

Referring to Figs. 1 and 2 of the drawing, I have shown a flexible conductor comprlsing a. plurality of strands 11, the strands at the end 10 being consolidated into a substantiallysolid and rigid mass, making a solid end to a flexible connection. The end 10 vof this conductor forms the movable contact of an electric switch and the other end of the conductor is fastened to a stationary terminal, as will be set forth more at length hereinafter. In my preferred construction, a tube or casing 12 is slipped over the end 10 of the conductor and the Y tube and strands contained therein are consolidated into a solid rigid mass by drop forging. The casing 12 is provided with a flared end 13 which will prevent abrupt flexing of the conductor when the switch is opened and closed and thus prolong its life.

In Fig. 3 of the drawing,I have shown an electric switch in which the conductor above described is employed. A stationary terminal 15 is shown mounted upon the/ panel 14 and the end 16 of the exible conductor is secured thereto. The flexible conductor is composed of a plurality of small strands 11, of conducting'material such as copper,

and is adapted to iiexback and forth as the switch opens and closes. The other end of the flexible conductor forming the contact 10 is carried by movable member 17 and is adapted to. make and break contact with a stationary contact 18.

The stationary contact 18 is supported at a point adjacent the contact 10 by a current carrying stud 19 which passes through the panel 14. The movable member 17 is Secured by a clevis 20 to a shaft 21, which is adapted to oscillate in response to any suitable means, as for instance, an electromagnetic means. As the shaft 21 oscillates it will cause the movable contacts of the switch to make and break contact with their respective stationary contacts to control the circuit in which they are connected. In addition to the main contact 10 the movable member 17 carries an intermediate contact 22 and an arcing contact 23. The main contact 10, the intermediate contact 22 and the arcing contact 23 are supported so that they make wiping contacts in closing and open in the reverse order of'their closing.

The contacts 10, 22 and 23 are all pivoted to the movable member 17 and are spring is, a similar stationary contact 25.

pressed toward their respective stationary contacts so that they will make a wiping contact when the switch is closed.

Mounted upon the panel 14 adjacent the intermediate contact 22 is a stationary contact 24 and adjacent the arcing contar 23 onnected between the stud 19 and contact 25 is a coil 26 which acts in a well known manner to blow out the arc formed between the arcing contact 23 and 25 as the switch opens. Interposed between the movable member 17 and the intermediate contact 22 is a nut or stop 27 for limiting the movement of this contact toward the closing position. It also acts to insure that the intermediate Contact opens and closes, in point of time, between that at which the main and arcing contacts open and close. This stop is preferably made adjustable so that the wear of the parts and the burning of this contact can be compensated for. A lock-nut 28 is provided to secure stop 27 in position when properly adjusted. The intermediate and arcing contacts 22 and 23 are provided with low resistance connectors or shunts 29 and 30, respectively, for carrying the current passing Vthrough said contacts.

Referring to Figs. 4 and 5 of the drawing, lthe main contact 10 is shown as pivotally supported on the movable member 17 by a U-shaped member 31 and a hook member 32. Cooperating with the U-sha ed member 31 and the hook member 32 an forming a fulcrum for said Contact is va spring 33 which forces contact 10 into engagement with the stationary contact 18 when the switch is in its` closed position. This type msv and its other end forming a movable contact adapted to make contact with said stationary contact, the strands at said end forming the movable contact being consolidated into a substantially solid and rigid mass.

2. In. an electric switch, a. stationary contact, a stationary terminahxa flexible conductor comprising, a plurality. of strands having one vend fastened to said terminal and its other end forming a movable contact adapted to make contact with said stationary contact, the strands at said end forming the movable contact1 `being enclosed in a tube, the Said tube and strands being consolidated into a substantially solid and rigid mass.

3. In an electric switch, a stationary contact, a stationary terminal, a flexible conductor comprisin a plurality of strands having one end lstened to said terminal and its other end forming a movable contact adapted to make contact with said stationary contact, the strands at said end l0 forming the movable contact being enclosed in a tube having a flared end, the said tube and strands being consolidated into a substantially solid and ri id mass.

In Witness whereof, I my hand this 18th day of October 1923.

CHARLES L. PERRY.

ave hereunto set 15

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