US2450256A - Electric switch - Google Patents

Description

sept, 28,1948.

R. N. ROWE BLEGTRI SWITCH .und July 31. 1945 [NVENTOR I.

Patented Sept. 28, 1948 ELECTRIC SWITCH Raymond N. Rowe, llainvillc, Conn., assigner to The Trumbull Electric Manufacturing Company, Plainville, Conn., a corporation of Connc'cticut Application July 31, 1945,'Scrlal No. 608,074

14 Claims. (Cl. 20o-151) My invention relates particularly to high ca pacity switches. One object is to provide a construction which is compact, rugged and reliable and capable of carrying heavy currents safely.

Another object is to minimize the enect of arcing by deionizing and quickly extinguishing the same.

When a double break contact is used, as for instance in the Rowe Patent 1,894,543, two arcs are formed in opening the circuit.. By locating the opposite stationary contacts close enough together the magnetic iields of the two arcs will repel eachother so that the arcs will bow away from each other. I'accordingly arrange discrete cooling grids, pins, screens, plates or other arc dispersing devices along the opposite sides of the path o! the movable switch contact so as to y quickly disperse the arcs.

I provide 'a number ofl spaced metallic plates either magnetic or non-magnetic so that in open:- ing the circuit the arcs are drawn between the contacts and dissipated without damage to the switch.

The movable switch member includes an insulating member which isy moved between the stationary contacts and the arc dispensing grids when the circuit is broken, thus greatly opposing any tendency of an arc to persist.

Fig. 1 is a plan view of the parts of a switch embodying one form of my invention.

Fig, 2 is a partial longitudinal section and side lview of the same, the movable switch member being shown in the open circuit position.

Fig. 3 is a partial cross sectional view of the same. A v

Fig. 4 is a perspective view of one ofthe compact terminal and contact members.

Fig. 5 is a perspective view of a part of the movable switch member with the attached contact rollers.

Fig. 6 is a perspective view of one of the arc disrupting plates.

Fig, 7 is a diagrammatic view showing how the arcs mutually repel each other when the circuit is opened.

In the form shown the stationary and movable parts of the switch are carried by insulating side vably cast integral With it.

plates or barriers lll, l0. Each of the oppositely disposed terminal lugs il isof any suitable type and is provided with a base plate i2 prefer- The base plates are mounted in grooves I3 andA held in place by screws Il.

Each contact part I5 is resilient and has a foot I6. Preferably there are two parts with their feet mounted directly on each base plate and secured by screws Il. The tip i8 of each contact part is curled around the edge of the base plate to ensure smooth action of the movable switch member. Each resilient contact is reenforced by a spring I5' supported in a recess in the base plate i2.

The movable switch member has an insulating slide or carrier 20 which is guided in grooves 2| in the side plates and slides between the oppositely disposed stationary contacts` i5, I5. This carrier has a lug 22 by which any suitable form of actuating mechanism (not shown) may be connected to the carrier.

The movable switch member has two contact means in the form of rollers 23 23 mounted to turn. loosely on inclined bearings 24, 24 which may conveniently be formed on the ends of side bars or anchors 25, 25 located in grooves 26 in the edges of the carrier and held by projections 2l extending into the edges of the carrier. These contact rollers are so mounted that they are given a rolling and rocking motion during their movement between the stationary contacts which affords a :flexibility that. insures good electrical contact and smooth movement therebetween.

These rollers are so arranged that their inner ends are close together and near the center line of the stationary contacts providing two contact portions extending in diverging relation forcentral part of the contacts where there is the greatest area of metal for cooling the arc.

'I'he contacts i5 are spaced suiliciently close so that when the double kbreak occurs the two arcs formed will have a. direct magnet eiect upon each other. The insulating carrier 20 is penetrated by the magnetic field but serves to prevent accidental direct arcing acrossl the stationary contacts.

Combined with this peculiar arrangement of contact rollers and as a final means for dissi- Dating the arc I provide a series of discrete metallic plates 2B which are mounted in the side plates or barriers i at each side of the path of the rollers and spaced apart from each other beginning at a point adjacent the stationary contacts. In breaking the, circuit the rollers pass through this space and by their action the arc is deionized and quickly extinguished. It will thus be seen that the insulating carrier 20 follows the switch contact members 23 between the stationary contacts i8, I 8 and between the opposed groups of the discrete grid members 28 so as to assist in the final extinguishment of any arc that might tend to persist.

In the present invention the diameter of the contact rollers is made so small for a given capacity of switch that the arc formed on one side of the roller has a deilnite magnetic eect on the oppositely formed arc and the two arcs mutually bend away from each other. Arc dispersing structures arranged as above can thereby dissipate the bent arcs.

By this combination-of features I have found. I

it possible to secure long life and reliability of action in a very compact structure.

Iclaim:

1. In an electric switch, a pair of resilient spaced contacts, an insulating carrier slidable between said contacts and having two contact rollers arranged on independent axes extending at an obtuse inclined angle with'respect to each other.

2. In an electric switch, a pair of resilient spaced contacts, an insulating carrier slidable between said contacts, U-shaped members having bearings carried by opposite edges of said carrier and a'contact roller mounted on each bearing beyond the end of the carrier and rotatably movable on said bearing between said resilien contacts.

3. In an electric switch, two opposed switch contacts, a terminal lug directly secured to each contact and a switch member slidable between said contacts, said member consisting of two rollers arranged with their axes inclined toward each other.

4. In an electric switch. two opposed switch contacts, a terminal lug directly secured to each contact and a switch member slidable between said contacts, said member consisting of two rollers arranged with their axes inclined toward each other and arranged to break the circuit at the inner ends of the rollers. I

5. In an electric switch. two opposed switch contacts, a terminal lug directly secured to each contact and a switch member slidable between said contacts, said member consisting of two rollers arranged with their axes inclined toward each other and arc disrupting plates arranged on both sides of the rollers during the movement of the switch member. Y,

6. In an electric switch, two pairs of opposed resilient switch contacts, a terminal lug integrally secured to each contact and a switch member slidable between said pairs of contacts. said member including a slidable carrier, two bearings loosely supported by said carrier with their axes inclined toward each other, a roller loosely mounted on each of said inclined bearings and adapted to contact one resilient contact on each side of the slidable carrier.

'7. In an electric switch, two pairs of opposed resilient switch contacts. an insulating carrier slidable between said contacts, two bearings loosely supported by said carrier with their axes inclined toward each other, a roller loosely mounted on each of said inclined bearings and adapted to contact one oi' the resilient contacts on each side oi' the slidable carrier, and arc dissipating devices supported adjacent said stationary contacts and spaced along opposite sides o! the path of movement oi' the carrier and its rollers for dissipating the arc as the roller contacts move to open circuit position.

8. In an electric switch oi the double break type, a pair of spaced stationary contacts o! opposite polarity in close proximity to each other, an insulating carrier slidable between said switch contacts, two inclined roller contacts carried by said carrier and adapted to move between and beyond said stationary contacts, arc dissipating devices supported adjacent said stationary contacts and spaced along the opposite sides of the path of movement of the carrier and its contact for dissipating the arc as the contacts move to open circuit position.

9. In an electric switch, a pair o! insulating walls spaced apart from each other and having guide grooves, metallic base plates mounted edgewise in the grooves between said walls, resilient contacts supported on said base plates between the walls and spaced apart from each other, terminal lugs integral with the base Plates. an insulating carrier slidable between said resilient contacts, a roller contact carried at the end of said carrier and discrete arc dispersing members mounted between said walls adjacent to said stationary contacts and on opposite sides of the path of movement of the insulating carrier and roller contact.

10. In an electric switch, insulating side plates. stationary contacts supported between said plates, a switch member slidable between said contacts and having contact faces inclined from the center outwardly and in a direction forwardly of the direction of movement in opening the circuit so that the circuit is broken at the center of the contact faces and discrete metallic arc dissipating members supported by said side plates and arranged on opposite sides of the path oi' movement of the switch member.

11. An electric switch construction comprising spaced insulating plates, a paix` of switch contacts supported between said plates, an insulating carrier slidable between said plates and having contact means with contact surfaces inclined from the center outwardly so that the central portion of the contact means is the last part of the contact means to break circuit between said switch contacts.

12. In an electric switch, a pair oi' spaced contacts, an insulating carrier reciprocable between said contacts, a contact roller movable with said carrier between said contacts. a U-shaped connection between said carrier and said roller, said connection having one arm pivoted in said carrier and having one arm forming a bearing for said roller at the end of said carrier.

13. In an electric switch, a pair of spaced apart stationary contacts, movable contact means and means mounting said movable contact means i'or slidable movement into and out of engagement with said stationary contacts, said movable contact means being provided with at least two contact portions extending in diverging relation torwardly of their direction of movement to disengage said stationary contacts.

14. In an electric switch, a pair of spaced apart stationary contacts, movable contact means. means mounting said movable contact means for slidable movement into and out of engagement 5 with said stationary contacts, said movable contact means being provided with at least two portions extending from substantially the center of said movable contact means outwardly in diverging relation forwardly of their direction of movement to disengage said stationary contacts so that said center is the last to disengage said stationary contacts. f

v RAYMOND N. ROWE.

REFERENCES CITED The following references are ofv record in the le of this patent:

Number UNITED STATES PATENTS Name Date Hunter Feb. 9, 1915 Bennett Feb. 18, 1919 Hendricks, Jr Apr. 4, 1922 Hammerly Nov. 29, 1932 McDowell Apr. 25, 1933 Jennings Sept. 24, 1935

Images