US3091677A

US3091677A - Shockproof electromagnetic contactor

Info

Publication number: US3091677A
Application number: US60659A
Authority: US
Inventors: Theodore F Rosing
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1960-10-05
Filing date: 1960-10-05
Publication date: 1963-05-28
Anticipated expiration: 1980-05-28

Description

May 28, 1963 T. F. ROSING SHOCKPROOF ELECTROMAGNETIC CONTACTOR 3 Sheets-Sheet 2 Filed Oct. 5, 1960 IIIIII'! NAAANNNNNI May 28, 1963 T. F. ROSING SHOCKPROOF ELECTROMAGNETIC CONTACTOR 3 Sheets-Sheet 3 Filed 000. 5, 1960 3,091,677 Patented May 28, 1963 SHOCKPROOF ELECTROMAGNETIC CGNTACTQR Theodore F. .Rosing, Whitefish Bay, Wis, assignor to Cutler-Hammer, Inc, Milwaukee, Wis, a corporation of Delaware Filed Oct. 5, 1960, Ser- No. 60,659 Claims. 31. 200-103) This invention relates to a shockproof electromagnetic switch designed for alternating current operation.

A primary object of the invention is to provide a highly compact switch for use at relatively high voltages in the range of 2,000 to 5,000 volts.

Another object is to provide such a switch in which the contacts may be quickly inspected and replaced if necessary.

The first object is accomplished by providing (1) va compact roller guide shockproof linkage construction and (2) encapsulated blow-out coils having physically smaller laminated wound cores producing the required blow-out field. The roller guide assembly requires less space than common shockproof linkages because of the rectilinear motion of the contact carrying carriages and the fact that the roller support will carry larger loads with smaller area as well as having low friction operation. The cylindrically wound cores are easier to manufacture than conventional cores. Their use also reduces the size of the coil construction and facilitates in manufacture.

Other objects and advantages will be pointed out in, or be apparent from the specification and claims, as will obvious modifications of the single embodiment shown in the drawings in which:

FIGURE 1 is a side view of a shockproof contactor embodying the invention with a portion broken away to show contact structure;

FIG. 2 is a top view of only the contact carrying portion of the contactor;

FIG. 3 is a sectional view taken along the line 33 of FIG. 2;

FIG. 4 is a front elevational view of only the contact carrying portion of the contactor;

FIG. 5 is a view in side elevation of only the blowout coil and are chute portion of the contactor;

FIG. 6 is a side view of a compact blow-out coil;

FIG. 7 is an end view of such blow-out coil; and

FIG. 8 is a perspective view of a cylindrical laminated wound core for a blow-out coil.

Referringto the drawings, the invention is shown embodied in a shockproof electromagnetic switch which has a contact carrying portion 16 and a blow-out coil and are chute portion both mounted on a vertical frame 14; the contact carrying portion being mounted so that it may be swung downward to expose the contacts for inspection and replacement.

The blow-out coil and are chute portion has an upper insulator arc attenuating section 10 of usual design including arc runners 1'1. Closely below the arc runners there is positioned a pair of blow-out coils 13 wound on laminated cores or pole pieces 12 that are secured by bolts 19 passing through an insulator panel 17. The panels 17 have openings 17a through which the cores project to make good magnetic connection with the pieces 12. The blow-out coil has been improved into a more compact structure. This has been accomplished by encapsulating the coil winding with epoxy resin 27 or the like, and then coring a circular bore 29 in the insulative resin through the inside of the coil winding 25. A laminated cylindrical Wound core 31 (see FIG. 8), formed by rolling a strip of suitable magnetic material, is inserted in the cylindrical bore. This core construction is much more compact than those of conventional design which employ stackedplates to form the coil core. The present coil, because of its reduced size made possible by this new-type core, can be nested closely below the arc runners without having to unduly spacethe contact carrying assembly below the bottom of the arc chutes 10, or Without having the coil projecting outwardly to the front or rear of the arc chutes. Compactness is essential in many uses of this type of shockproof switch,

and the improved blow-out coil design contributes to the overall size reduction of the present switch. Flux from a front blow-out coil enters the pole piece and then passes into the contact gap where it interacts with the flux pro .duced by the arc to exert an upward force on the arc in the gap. The back blow-out coil creates a similar fieldand these fields force the are created upon contact separation from the contacts to the arc runners 11 along the arc runners and up into the arc chutes 10 so that the arc is attenuated and thereby extinguished.

The contact carrying portion 16 has pairs of

opposed contacts

18, 20 mounted on a shockproof linkage (described below) which is carried by spaced channel shaped horizontal frame members 32. The horizontal frame members 32 are pivotally secured to the vertical frame 14 in a manner described in detail below. The contacts project upward into operative relation with the blowout coil and arc chute portion of the contactor.

The shock proof linkage consists of identical and oppositely actingcarriageassemblies. One carriage assembly includes an E-shaped armature 21 and one or more fixed contacts 18 fixed to a support plate 26 which in turn is fixed to the upper flanges of

channels

26, 26. Each of the channe1s26 ride on pairs of spaced

rollers

28, 28

which rotate on bolts 30 secured to the Web of each of the horizontal frame members 32. The other carriage assembly includes a like but oppositely displaced E- shaped armature 22 and one or more contacts 20 mounted on a supportplate 24 which in turn is fixed to the lower flanges of spaced apart channels 29, .29. Each of the channels 29' ride on

spaced rollers

31, 31 which rotate on bolts 30 secured to the webs of the horizontal framemembers 32. An encapsulated energizing coil 35 is secured to a mounting bracket 33 which is secured to the horizontal frame member 32, and each armature is positioned on its respective support plate so that its cent-er leg 34- is attracted to the coil interior when the coil is energized.

This arrangement results in a compact structure inasmuch as it permits the channels of each pair to overlap the carriage member to which they are not attached thereby permitting the support rollers to be spaced apart the entire depth of the assembly thereby maximizing the support span without increasing the depth of the contactor. A link 40 is pivoted to each of the horizontal frame members 32 at the n1id-portion 42 of the link and has slotted ends 4-4 into which pins 46, which are fixed to

adjacent channels

26 and 29 extend. The slotted ends of the link accommodate the lateral motion inherent in this linkage when the

adjacent channels

26 and 29 move with respect to one another and maintain an operative connection between the channels throughout such movement.

Thus, when a shock is exerted along the line of movement of the carriages, one carriage produces a clockwise force moment about the pivot point of the link, and the other carriage produces an equal counterclockwise force moment with a resultant cancellation of the effect of the shock force so that the carriages, and hence the contacts, remain in whatever position they occupied at the moment of the shock. Springs 48 normally bias the carriages apart, but when the coil is energized the armatures are attracted and the springs are overcome.

Each contact is connected through a lead 50 to one end of a coil winding 25 forming part of a blow-out coil 13. These leads are slack when the coil is deenergized so that when the coil is energized the leads do not inhibit carriage travel. The leads connecting the front contacts 20 to their blow-out coils are detachable for reasons next described. It is often desirable to inspect the

main contacts

18, 20 and to this end, the horizontal frame member 32 is pivoted to the vertical frame member 14 so that the contact carrying portion of the contactor may be swung down to expose the contacts. The horizontal frame member is normally supported by two spaced

bolts

72, 74 at the top and one bolt 75 at the bottom. One top bolt hole 76 communicates with an inclined slot '78 so that the entire contact carrying portion may be swung down by removing bottom bolt 75 and loosening

bolts

72 and 74. This is done :on both sides of the symmetrical frame and detachable leads 50 are detached from the front blow-out coil winding. The contact carrying portion is then free to pivot on bolt 74, and bolt 72 slides to the end of slot 78 which limits the downswing of the contact carrying portion of the contactor. The horizontal frame is tapered adjacent to the vertical frame so that it does not interfere with the downswing. This tapered portion may butt against the vertical frame and stop the downswing under certain tolerance conditions but, in any event, a stop on the downswing is provided by either the bolt reaching the end of the slot or by the horizontal frame butting against the vertical frame. Of course, the same swingdown action is secured if the slot is placed adjacent a bolt hole in the horizontal frame member.

Interlock switch mechanism 65, which forms no part of this invention, of the sliding engagement type for controlling auxiliary circuits is provided with one movable actuator bar fixed to one carriage through arm 66 and another movable actuator similarly fixed to the other carriage through arm 70.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. In a shockproof electric switch, a frame, rollers rotatably mounted on said frame, a pair of contact carrying carriages which are each supported and movable on said rollers with respect to said frame, an electromagnetic coil carried by said frame, a pair of armatures respectively mounted on said carriages in line with said coil, and linkage means interconnecting said carriages so that the masses of said carriages and their armatures oppose 4 each other under shock so that their positions are unaffected.

2. The combination according to claim 1 in which the movement of said carriages includes a common plane, one carriage including a channel lying above and closely adjacent said common plane, the other carriage including a channel lying below and closely adjacent said common plane whereby the height of the contactor is held to a minimum.

3. The combination according to claim 1 in which the supported portion of each carriage overlaps a portion of the other carriage whereby the depth of the contactor is held to a minimum.

4. The combination according to claim 1 in which said linkage means comprises a member pivoted on said frame and having a longitudinal slot in each end, each carriage having a pin extending therefrom, the pin on one of said carriages extending into the slot in one end of said link and the pin on the other of said carriages extending into the slot in the other end of said link.

5. An electromagnetic shockproof switch for actuation by alternating current comprising, a frame, a coil carried by said frame, a first pair of rollers rotatably fixed to said frame, a first member guided by said first pair of rollers, a first support plate fixed to the bottom of said first member, a first armature carried by said first support plate for movement toward and away from said coil, a first contact also carried by said first support plate, a second pair of rollers rotatably fixed to said frame, each pair of rollers being mounted so that a line through the centers of one pair is parallel with a line through the centers of the 'other pair, a second member guided by said second pair of rollers, a second support plate fixed to the top of said second member, a second armature carried by said second support plate for movement toward and away from said coil, a second contact also carried by said second support plate, said contacts positioned to contact when said coil is energized, and a link pivoted at its mid-point to said frame and having one end connected to said first member and the other end connected to said second member, the total mass of said first support plate, first member, first contact and first armature being equal to the total mass of said second support plate, second member, second contact and second armature whereby said first and second members act equally and oppositely under shock.

References Cited in the file of this patent UNITED STATES PATENTS 2,223,105 Howe Nov. 26, 1940 2,474,742 Kuhn June 28, 1949 2,756,302 Baltuch July 24, 1956 2,794,882 Russell June 4, 1957

Claims

1. IN A SHOCKPROOF ELECTRIC SWITCH, A FRAME, ROLLERS ROTATABLY MOUNTED ON SAID FRAME, A PAIR OF CONTACT CARRYING CARRIAGES WHICH ARE EACH SUPPORTED AND MOVABLE ON SAID ROLLERS WITH RESPECT TO SAID FRAME, AN ELECTROMAGNETIC COIL CARRIED BY SAID FRAME, A PAIR OF ARMATURES RESPECTIVELY MOUNTED ON SAID CARRIAGE IN LINE WITH SAID COIL AND LINKAGE MEANS INTERCONNECTING SAID CARRIAGE SO THAT THE MASSES OF SAID CARRIAGE AND THEIR ARMATURES OPPOSE EACH OTHER UNDER SHOCK SO THAT THEIR POSITIONS ARE UNAFFECTED.