US473228A

US473228A - Edward h

Info

Publication number: US473228A
Authority: US
Publication date: 1892-04-19
Anticipated expiration: 1909-04-19

Description

(No Model.) A'

E. H. JOHNSON. ELECTRIC SWITCH.

NO- 473,228- Patented Apr. 19, 1892.

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UN'ITED STATES PATENT OEETCE.

EDllARD H. JOHNSON, OF NEV YORK, N. Y.A

A ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 473,228, dated April 19, 1892.

` Application tiled August 25, 1891. Serial No. 403,726. (No model.)

To a/ZZ whom it may concern/:-

Be it known that I, EDWARD H. JOHNSON, a citizen of the United States, residing at New York cityfin the county and State of New York, have invented a certain new and useful Improvement in Circuit Making and Breaking Switches, of which the following is a specilication.

The present invention relates to that class of circuit making and breaking devices generallyv known as snapswitches-that is, switches in which the switch-arm or Contact is thrown by a spring to cause an instantaneous make and break of the circuit to avoid the formation of a hurtful arc at the contacts. The switch which forms the subjectmatter of this speciiication is well adapted t for use with circuits carrying currents of any character,but is designedV more especially for currents of considerable quantity and high tension, the construction being such that dangerous heating at the contacts while the circuit is closed or arcingon opening the Circuit is practically impossible, and the construction is such that should the contacts begin to heat from any cause they become more firmly pressed together by the expansion of the metals, and their carrying capacityis thereby automatically increased. In this snap-switch the contacts are preferably rigid plates or blocks instead of yielding springs, and when the switch is operated to close the circuit the contacts are firmly wedged together and held between two rigid or unyielding surfaces or bodies, as in a vise, the

spring which is designed to throw the movable Contact exerting its whole force to wedge the contacts together. Y

Other important features and advantages will appear in the following description.

In the accompanying drawings, Figure 1 is a side view of the preferred form of my improved switch. Fig. 2 is a central section of the upper portion of the switch on linear @cof Fig. 1. Fig. 2a is a cross-section on line y 'y of Fig. 1. lFig. 3 is a plan View of the lower section of lthe switch. Fig. 4 is a plan view of an insulating-plate adapted to tit over the lower section of the switch, and Fig. 5 is an inverted plane of the upper section of the switch.- A

Each ofthe terminals is provided at one end with a Contact portion 6, the upper faces of which are preferably in the same plane. 6o

These contact-faces are inclined or beveledv through a large portion of their length, but are flattened for a greater or less distance at the end at which contact is broken, as indicated at 7. The ends of the Contact portions of the terminals are inclined or beveled outward, as shown at 8, so that when the connecting-plate leaves the terminals it has no tendency to forman arc between the two adjacent edges or corners of the terminals, but 7o any arc to be formed must bridge the distance between the outer corners 9 of the terminals. At the center of the base 'is lixed a screw-threaded sleeve 10.

11 is an insulating plate or screen having 75 openings l2, adapted to fit over the terminal contacts, and the central sleeve 10 to inclose. the main bodies of the terminals and the connect-ing devices carried by the base.

The second or upper section of the switch 8o consists of a movable body consisting, preferably, of a metal plate 13 of sufficient thickness to be rigid-that is, to resist the tendency to bend or yield und er any strain which is put upon it in the ordinary use of the switch or which may be imposed by the expansion y of the contacts under high degrees of heat-an insulating-plate 14, and an outer insulatingplate 15. In the'latter plate are two dovetailed openings 16, in which the connecting 9o plates or blocks 17 are fitted, and midway between them are two similar but smaller openings, in which are the blocks 20. The plate 14 is provided immediately under the center of the plates 17 with raised ribs 1S only par- 95 tiall y as wide as said plates. The plates 17 have inclined or beveled faces,as already described in connection with the terminal contacto 6. The contact or connecting plates 17 are preferably grooved through the center, Ioo and an insulating-screen in the form of a ring 19 is set into said grooves and into a correi cent to each other.

vease spondug groove in the plate 15. Vhen the switch is built up, this screen extends between the contact portions 6; but it is evidently not necessary that the ring should be carried by the movable member. The detentplates 2O are only one-half as wide and are placed inline with but one set of the contactterminals, as shown in Fig. 5. At the center of this member of the switch and` preferably formed integral with the plate 13 is an internally-screw-threaded sleeve 2l, into which works the metal screw 22, formedat the bottom of the square spindle 23, onto which fit the sleeve and handle 24 `25. rlhroughthe1 center of thehandle, sleeve, and spindle passes" a screw 2G, the head of which is adapted to bear againstthe shoulder 27 and the lower end of which is adapted vto `screwinto the; sleeve `10 on the base, the shoulder 2S bearing against the top of saidsleeve.

`29 `is a spring, one end of which is con neet-ed `to=theiplate -13at 30iand the other end of` which isconneeted to the disk orcollar31, `which moves witlrthe handle25 and spin-v ldle i able member.` of the switch.

NVhenthe `parts of the switch `are. put together, thespring'29willbe given an initial tension. `\V.hen the handle `is-graspedand turned, two `operations take place--naincly, since the screwthreaded `spindle 23 isfheld `from.longitudinal motion as it.s turned, the` movable member of theswitclr will ride upon the wthread, thereby tending to separate the beveled connecting or contactplates from` the beveled` terminal contacts-that is, to move `themdirectly away from each other ina cli-rection parallel to thespindle-so that they can pass each other without much friction, and at the `sametime the'spring 29`is put under in` creased; tension, so that when the flat faces 7 of `the'connecting-plates and `terminals come together the spring will have sufficient tension to throw the movable member forward instantaneously and with great force. The lat faces 7 allow the contacts to move forward .when `they have been separated far enough` to bring the highest points of thebevels adjaltwillbe clear that if we startwith the circuit closed the first movement'of the switchwill break the circuitand bringfthe movable member4 to rest, with the1 `detent-plates 2O bearingagainst the contact-` faces of the outer terminals 2.

While this arrests the movable` member itholds the cir-` cuitopen. 'Vhen the switch is `again moved in the same direction, sincethe switch is constructed `toA move forward whether the circuit` ist to be made or `whether it is t'obe broken, the

Vbroad plates 17 are thrown forward and rest on the contact-faces of the terminals 2 3, thereby connecting them and completing the circuit.

It may happen that one contact-surface will be a trifle lower than the other surface, and in this case if the plates 17 were immovable bad contact or no contact with one of the terminals would be obtained; but by providing the ribs 1S behind the plates 17 they are allowed to rock transversely, and hence can accommodate themselves to any slight irregularities in the contact-surfaces. Since the spring throws the wedge-shaped connectingplates forward against the wedge-shaped terminal contacts with a good deal of force and since both the connecting-plates and the terminals are held rigidly from moving in a direction away from each other, the best possible contact is obtained and a contact which is capable of carrying all the current which the metal ofthe terminals and binding-posts is `capable of conducting. lf heating occurs at the points of contact, whereby themetalis expanded, the effect will be to cause more perfect contact, owing to the rigid support of the parts, thereby automatically increasing i the cond uctivityV atthe contacts and enabling the switch `to carryimore current. 'The construction ofthe switch is such that when .the

circuitis closed `it is permanentlylocked against reverse-movement by the arrangement of thescrew-threads-and'canonly be operated bya positiveforward movement. In switches Vhaving `yielding spring-contacts the quality of the fcont-actis dependent on thestrength ofthe springs, and when the springs become heated, as frequently happens, their resiliency is impaired, thereby lowering `the efficiency of the switch. This Atrouble is avoided in the switch above described.

1. The combination, inaswitch,of two rigid members corresponding to thejaws ofza vise. one of which membersis movable repeatedly `in the same directionin making andbreaking circuit, contacts carried by the switch members, which when the circuitis closed are held in contact between said rigid.v members, said members being positively held from moving away from each other, andmeansfor disengaging the contacts, substantially as described.

2. The combination, in as-witch, of two rigid members corresponding to` the jaws of a vise, one of which members ismovable repeatedly in the same direction in making and breaking circuit, contacts carried on the two adj acent sides of the rigid members, which contacts when the circuit is closed areheld in contact between said rigid members,-means for separating the contacts, and a spring for throwing one member, with its contacts, forward, substantially' as described.

3. A circuit making and breaking switch `having fixed andmovable beveled or wedgeshaped contacts, rigid and 4relatively-movable bodies, on two adjacent sides of which the contacts are mounted, a spindle for the `mov- IOO IIO

IISI

rection of the length of the spindle when the circuit is closed, whereby when the circuit is closed the contacts are wedged and held together between said rigid bodies, substantially as described. v

4. rlhe combination, in a snap-switch, of a fixed and a movable rigid body having a central spindle, the movable body being positively held from moving away from the other body, a spring for throwing the movable body, and contact devices between said bodies and in position to make and break contact as the movable member` is turned on its spindle, substantially as described.

5. A circuit making and breaking switch having fixed and movable contacts, rigid bodies, on two adjacent sides of which the contacts are located, which contacts when the circ'uit is closed are pressed together between said rigid or unyielding bodies, and permanent locking devices for locking the movable bodies and contacts against reverse movement, substantially as described.

6. A circuit making and breaking switch having fixed and movable rigid bodies parallel with each other, contacts on two adjacent sides thereof, whichwhen the circuit is closed are wedged together between said rigid or unyielding bodies, permanent locking devices for lockingthe movable member against a backward movement, and a spring for throwing the movable Contact when the switch is operated, substantially as described.

7. The combination, in a switch, of a stationaryrigid member, a movable rigid member, which is mounted so that it can be rotated in one direction only in making and breaking the circuit, engaging contacts carried by s aid switch members, and means for rotating the movable memberand for moving it toward or from the stationary member, whereby when in one position said contacts are wedged together between the rigid members, substantially as described. l

S. A circuit making and breaking switch having fixed and movable rigid bodies, contact's between two adjacent faces thereof, which when the circuit is closed are wedged together between said bodies, the contacts havin g faces beveled fora portion only of their length, means for moving the contacts directly away from each other, and means for advancing the movable contacts, said latter means operating when the contacts have been moved vfar enough apart to bring the highest points of the bevels on the contacts adjacent to each other, substantially as described.

9. The combination, in a switch, of two members carrying contacts, one member being fixed and the other movable, a screw rotatable only in one direction and held from longitudinal movement, said screw working in a nut carried by the movable member for moving it from the fixed member whenv the switch is movedV to its open position, and means for turning the movable member on the screw, thus causing it to ride toward the fixed member, said screw constituting a spindle on which the movable member turns, substantially as described.

10. The combination, in a switch, of two members carrying contacts, one member be-. ing fixed and the other being movable, a screw rotatable onlyin one direction, said screw being threaded in such direction that when the screw is turned the movable member will be carried away from the fixed member, and a spring connected to the screw and to the movable member for throwing the'la'tter forward, thereby causing it to ride down on the screwthread, substantially as described.

1l. The combination, in a switch, of' two rigid members, contacts carried thereby, which when the circuit is closed'are held in contact between said rigid members, which membersare movable always in the same direction both in making and breaking the circuit, means for disengaging the contacts, and means for arresting the same before the circuitis again closed, substantially as described..

12. The combination, in a switch, ot two switch members, contacts carried thereby, which when. the circuit is closed are held in contact between said members, a s crew held from longitudinal movement engaging with and adapted to move one member for-disengaging the contacts, and a spring for throwing the movable member, with its contact, forward, causingit to ride' downon the screw, substantially as described.

13. The combination, ina switch, of a base adapted to be connected to a support carrying circuit-terminals separated from each other, a rigid movable member fitting over the base and carrying connecting devices adapted to co-operate with the terminals to electrically un-ite them, a screw-threaded sleeve in said movable member, and a screw held from longitudinal movement, but adapted to turn in said sleeve, whereby when the screw is turned the movable member is raised and permitted to advance, substantially as described.

14. The combination, in a switch, of a base adapted to be connected to a support carrying circuit -terminals separated from each other, a rigid movable member tting over the base and carrying connecting devices adapted to co-operate with the terminals to electrically unite them, a screw-threaded sleeve in said movable member, a screw held from longitudinal movement, but adapted to turn in said sleeve, and a spring connected to the screw and to the movable member, whereby when the screw is turned the movable member is raised and advanced, substantially as described. Y

15. The combination, in a circuit making and breaking switch, of a xed member, a member adapted to rotate, terminal-contacts on the fixed member, an insulating-screen extending between the same, and a connectingplate or connecting-plates on the movable member, substantially as described.

16. The combination, in a switch, of a con- IOO lIO

necting plate or device and a pair rof terminals having contact-faces and arranged adja` cent to each other side by side, the end of the contact portion of each terminal at which the connecting device leaves it being inclined or beveled away from the other terminal, whereby when the connecting device breaks the circuit no are can be formed between the adjacent edges or corners of said terminals, substantially as described.

17. The combination, in a switch, ofA a eon neeting plate or device and a pair of terminals having contact devices and arranged adjacent to each other side by4 side, the end of the contact portion of each terminal at which the connecting device leaves it being inclined or beveled away from the other terminal, whereby when the connecting device breaks the circuit no are can be formed between the von one member, and a contact or connecting plate on the other member adapted to electrically unite said terminals, `said plate having a `transverse movement, whereby it is adapted `to rest squarely 0n both terminals, substantially as described.

This specification signed and witnessed this 24th day of August, 1891.

EDVARD II. JOHNSON.

'Vitnesses:

F. A. MASON, EDWARD F. SEIXAs.