US2616998A - Remote operated multiple element double break switch - Google Patents

Description

P. SALA Nav. 4, 1952 REMOTE OPERATED MULTIPLE ELEMENT DOUBLE BREIAK SWITCH 2 SHEETS-SHEET 2 Filed May 11, 1949 PAoLo SALA Patented Nov. 4, 1952 REMOTE OPERATED MULTIPLE ELEMENT DOUBLE BREAK SWITCH Paolo Sala, Milan, Italy Application May 11, 1949, Serial No. 92,594 In Italy May 31, 1948 7 Claims. 1

The present invention relates to improvements in multiple double break switches and is particularly concerned with switches adapted for remote Operation. The construction of such switches has tended to favour the use of simultaneous double break contacts particularly for small power. In these-contacts, the two distances between the fixed contacts and the movable contact add up, so that the Opening speed is doubled, and therefore the extinguishing of the arc is more efcient than in the simple break types. For this purpose, the solenoid type of electro magnet with a linearly movable armature generally working vertically, is used in preference to electro magnets with hinged armatures. With such linearly moving electromagnet devices it is necessary to take particular care that the strains on the movable score are perfectly balanced, because unbalanced loads would cause seizing of the movable core. The magnet must be exactly in a central position in relation to the load distribution, and this problem has been solved heretofore by adopting special armatures to support the two parts of the magnet. It is evident that, with this system, every difference in the load distribution, as for instance an addition of contacts for special purposes, is ether structurally impossible, as in most of the types in use, or requires the construction of a different armature for every required modiflcation. An object of the present invention is to provide a switch of the described character formed of similar, superposed, contact units operated by a common electro magnet which is constructed and arranged: so that the electro magnet may be centrally disposed irrespective of the number of contact units-embodied in the switch.

Another object is to provide a switch of the described character Wherein one or more operating electro-magnets may be conveniently mounted on the stacked or superposed contact units .to work in parallel.

Another object is to provide a switch of the described character which is Constructed and arranged so that the various assembled parts thereof maybe-put together and separated in a simple manner and without the use of tools.

Another object is to provide a switch of the described character wherein the movable core of the Operating electro magnet is easily connected to,,or separated from, the movable contact carrying member and further serves to hold the magnet coil in operative position.

Still another object is to provide a switch of the describedcharacter Wheren the movable and 2 fixed contacts may be easily removed or replaced and are formed to be adjustable to permit the exposure of fresh contact surfaces from time to time.

A further object is to provide a switch of the described character wherein the various terminals may be connected or disconnected Without the use of tools.

The above and other objects, features and advantages of the present invention will be apparent in the following detailed description of illustrative embodiments thereof, which description is to be read in connection With the accompanying drawings forming a part hereof and Wherein:

Figure l is a perspective view of a switch device embodying the present invention, and with certain ofv the parts removed to afford a clearerrview of others.

Figure 2 is a top plan view of a switch device similar to that of Figure 1, but With an assemblage of three elements instead of the four seen in Figure l,

Figure 3 is a vertical sectional view taken on the lineV X X in Figure 2,

Figure 4 is a side elevational view of the device of Figure 3 and Figure 5 is a perspective view of a pair of small platesV of refractory material which form an arc-chute.

Referring to the drawings in detail, the improved switch device in general terms comprises a series of contact-carrier elements, all similar, and assembled together to form a supporting frame. The number of contact-carrier elements assembled together depends upon the number of switch contacts and terminals required by the associated electrical Circuit. These elements are connected to the Operating magnet by screw threaded assembling rods, which secure the elements to each other and are also used to clamp the device to its support. Each of the carrier elements is composed of a pair of plates I' of insulating material, stamped Bakelite for example, mounted face to face. The plates i are shaped in such manner that whenassein'oled together as pairs they enclose hollow spaces adapted to receive all the metallic parts used for the electric contacts and terminals. The device comprises as many pairs of plates or basic elements I as there are sets of contacts. The paired plates i are clamped together by means of three through rods 2 arranged at the points of a triangle, that is, With two threaded rods extending through the corner portions of the superposed plates at one side and with asingle centrally located rod at. the

aciaeoe other side. The rods 2 pass through suitable holes 3 provided in the plates i and their screw threaded ends receive the respective tightening nuts to clamp the stacked plates therebetween. The plates i are formed with relatively shallow recesses on both faces of the corner portions through which the rods pass to provide hollow spaces I equidistantly spaced vertically along the corners of the assembled plates. The magnet includes end plates, enclosing the laminae of its fixed core, and each formed with two perforated lugs 5, Figure 3, spaced laterally apart sufiiciently to fit into the spaces li of the assembled pairs of plates l. The end plates of-the maget are themselves spaced apart a distance equal to the distance between the successive spaces d so that it is always possible to put the electromagnet in a central position relatively to the supporting frame, Whether the number of the basic elements is odd or even. The electromagnet is connected to the supporting frame by the two assemblying rods 2 passing through the corner portions of the plates i and which extend through the openings of the lug i, so that any further magnet supporting means is unnecessary. In addition, the hollow spaces d may be used for the fastening tothe device, by means of the rods 2, any other accessory parts, as for instance, push-buttons, additional clamps and the like. The rods 2, may be appropriately extended beyond the outermost plates i to serve for fastening the whole device to walls, frames and other supports.

Each element has between its pair of plates l, at the side remote from the magnet, two fixed contact rollers G, which are connected with respective wire binding clamps or terminals. Each contact roller (i with its respective clamp, briefly called contact-clamp CM, comprises a roller 6 of good conducting material, copper for example, forming the actual contact. At the ends of each roller, two side plates l', Figure 1, are tightly fixed by screws having countersunk heads El. The plates Z', at their ends remote from the related roller are connected together by a small tube 9 (Figures 1 and 4). On each cf these tubes 9 are mounted a coil Spring l l interposed between a bearing plate is, and a washer l2. Between the. washer 22 and the adjacent side plate i a forked metallic terminai i may be removably inserted. The terminal i preferably has its ends curved to suit the radius of the washer, and is held in place by the spring urged washer itself. To the terminals IS are connected the inlet and outlet wires of the electric circuit. Each bearing plate l is preferably T-shaped to provide lateral ears which engage behind lugs or projections fii formed on the plates i to hold the contact-clamps between the related plates i. In the above described contact-clamp, the part 6 has been described -as being in the form of a roller, however, a piece of diiferent shape may be substituted therefor.

Each pair of plates i defines a central hollow or space l therebetween into which are laterally introduced pairs of refractory plates 55, for example, formed of steatite (Figure 5), held in place by the associated contact-clamp. These refractory plates constitute arc-chutes and serve as protection against burning caused by the breaking arc. In the spaces between the refractory plates l the contacts l 6 are movable linearly, these contacts It being rectangular conductive rods disposed on a contact-carrier l'l (Figs. 1 and 3). The contact-carrier l may be formed from a metal blank of cross shape, two opposite wings being bent upwards or in the direction away from the magnet to form the carrier, and the two others bent downwards or towards the magnet for a purpose to be described. The upper ends of the two upwardly bent wings are bent inwards until they almost touch, in order to enclose a rectangular space between the central part of the cross and the bent ends (Figure 1) receiving a plate Hi formed with ends of reduced width which are slidable in two openings formed in the two above mentioned wings. Between the plate lt and the bottom of the contact carrier l there is inserted a spiral spring is which presses the plate is towards the inwardly bent wings. The conducting rods lt are introduced between the plate I8 and the inwardly bent ends of the wings of the contact-carrier il. The interior edges of the projection S, Figures 1 and 5, of the refractory plates 95, are engaged by the ends of the contact rods is for avoiding the lateral shifting of the latter. The two downwardly bent wings of the contact carrier l'l form what may be described as an inverted U, and therebetween receive two pieces 29 of insulating material each having the crosssectional shape of an irregular U (Figures 1 and 3). The insuiating pieces Zil present on their external side, a projecticn which penetrates a suitable opening formed in each of the down- Wardly bent wings, so that these pieces 20 remain connected to the said Wings. bar ZI, formed by an elongated member of C- shaped cross-section and providing a channel Opening towards the magnet, corresponds in its external shape to the internal hollows of the insulating material pieces 23 and is movable longitudinally within the latter. The movable bar 21 is as long as the supporting frame assemblage and is kept centered by two elastic plates 22, placed on the two outer faces of the supporting frame itself. The Operating electro-magnet, the insulated mounting of which has been previously described, is of the type having a linearly movable core drawn into the coil When the latter is energized, with self-adjusting pole pieces which are the subject of United States Letters Patent No. 2,510,298. The electromagnet comprises an inverted U-shaped fixed core 23, provided with two self-adjusting pole pieces 241, and with a movable core 25, having end side plates 25. The parts marked 26 are the nonmagnetic end plates enclosing the magnetic laininae of the core. These plates 25 extend beyond the movable magnetic core 25 and pass through two openings formed between the central part of the fixed core 23 and the respective end plates of that core. The extending portion of side plates 25 are formed With slots which serve to connect the movable core 25 to the bar El. The opposite edges of C-shaped bar 26 are provided with two pairs of similar notches 21, Figure 1. The distance between two notches 21 in the same edge is equal to the distance between the two end plates 25 of the movable core. In the extreme end part of each of the end plates 26 of the movable core, lateral notches ZA, Figures l and 3, are formed to receive the opposite edges of the bar ZE.

end protruding from the supporting frame. The hollow space enclosed by the fixed core 23, accommodates an electromagnetic coil 253, wound on a stamped insulating bobbin of the same size as the hollow space receiving it. The bobbin is provided with four spring clamps or terminals M, Figure 4, and has two stops SI engageable against the fixed core for centering the coil. The bobbin defines an internal open ended space rectangular A single movable The bar 2! has a hook 23 Figures 2 and 4 formed on one' in cross section, in which the movable core 25-26 is linearly slidable. In extensions of the end plates 23 of the fixed core there are placed two small insulating blocks 32 (stamped Bakelite for instance), for supporting the two self-adjusting pole pieces Zil. The blocks 32 are engaged in the end plates of the fixed core 23, by means of the tWo projections Figure 4, and each contains a contact clarnp with a respective spring 35, washer 3-3 to provide a wire terminal. In the extensions of the end plates 25 of the movable core 25-26 remote from the ends attached to the bar 2 I, a movable contact E is supported, by means of two insulating blocks 38, for engagement against the two fixed ccntact-clamps se. The electromagnet, however, could be of a different type and shape from the above described, provided that it operates to draw the movable core further into the coil when the latter is energized.

Finally, the plates i are internally shaped, so as to enclose hollow spaces 5.113, Figure l, designed to receive the fixed parts of lower contact-clamps, that is, contacts that are closed when a reniote operated switch is opened. A contact 41 is slidable through an Opening in a box-shaped frame 122 which is open at the outer side and at the side facing toward the magnet and has an inner .side wall formed with proiections at its opposite ends for engagement in ccrresponding grooves formed in the plates i. Moreover, the frame 42 is provided With a bent tab at the side of the Opening through which the contact ii extends in order to guide the latter during its movement under the infiuence of a torsion spring The latter is wound on a guide tube fif, in the interior of which is placed a pressure spiral Spring A of the same type as spring arranged to press against a terminal forming washer 3EA, both mounted cn a small pin riveted to the two side walls of the contact frarne 542.

To insure the continuity of the electric connection between the contact ii and its frame :22, a fiexible plate, not shown in the drawing, is electrically connected therebetween. A wire terminal S, similar to those marked i, but of smaller size, may be engaged between the washer SSA and the adjacent wall of the frame 42. The electric connection between two of these lower contact-clamps, placed between a pair of plates i, is formed by the rods lt of the movable main contact, in its usual rest position.

In assembling the described device it is necessary, first of all, to put together the supporting frame with as many basic elements as the number of the needed contacts, held initially together by the single centraily located rod 2; then, a movable fitting for each of plates i, each fitting being fcrmed of a pair of the insulating pieces 28, is mounted on the bar 2 i and the ccntact-carriers l provided with i and plates EB are assembled on the rnounted movable fittings. It should be noted that these movable parts can freely move along the bar fi; and the assembly formed by the bar 2! and the various parts I'i to 2f3 is then inserted in the Channel of the supporting frame defined by suitable cutouts forined in the plates i to receive and guide the various movable contact supporting parts during the working stroke. To complete the movable contact section of the switch assembly, the rods i that form the mcvable contacts, are simply introduced into the hollows i.. of the frame and inserted between the related plates 13 and the contact-carriers l'l. When thus assembled, lateral removal of the bar 2! is prevented by the rods 6, IG which rest against the internal wall surfacs of the plates i. The fixed core of the electromagnet is now inserted by introducing the ears 5 thereof into selected spaces i of the frame, as has been already described, in order to locate the fixed core centrally relative to the supporting frame. The two rods 2 extending through the corners of the plates i are introduced into the respective holes 3 and the assembly is secured together by tightening the nuts on the ends of rods 2, after having fixed the elastic plates 22 at the two ends of the supporting frame. Two pairs of refractory plates i are next introduced from opposite sides into the hollows id defined between each pair of plates i. These refractory plates protect the internal walls of the plates i of the supporting frame from the arc, and by means of their S- sha-pe, form the upmost limits of movement of the rods l, whilst keeping them centered. The. previously assembled main -contact-clamps CM are now inserted from the top, that is, at the side of the frame remote from the magnet, into the spaces formed between the plates i of each element, and each roller is simultaneously introduced into the hcllow i? formed by the two refractory plates i so that the latter are thereby fixed in their respective places. The coupling of the supporting frame of each contact-clainp CM, with respect to the related plates i, is simply obtained by pressing it down in the respective hollow, so that the bearing plate it, sliding on the sloping projecting edges L'lof the plates, compresses the Spring ii until the projections or lugs on the T-shaped plate id engage under the corners of the proiecting edges iiS and thus lock the contact-clarnps CM in place within the supporting frame. In order to remove each contact-clamp CM, the plate i) is depressed against the force of the Spring H until it is clear of the corners of the protruding edges and then the contactclarnp is free to be pulled out of the frame. If necessary, it is possible to change the distribution of the holiows in the elements, in order to introduce the contact-clamps from the sides rather than from the top in a manner similar to that described above.

To finish the assembling of the essential parts of the remote operated switch, it is necessary to complete the electroinagnetic core. For this purpose the coil, with its bcbbin, is moved into the central space of the fixed core until the stops Si of the bobbin rests against the adjacent end plate of the fixed core. The two self-adjusting pole pieces 2-4 are fitted on their seats and they are supported by the insulating blocks 32 that have been introduced in the lower cerners of the fixed core end plates. The movable core 25-26 is then slidably introduced from the bottom, through the hollow of the -bob'bin 36 of the coil and through the two guide openings provided in the fixed core. To couple the movable core 25-26 to the bar 21, it is necessary to depress the ho-ok 28, Figure 4, completely, so that the bar 2| moves longitudinally, against the resistance of the lower ela'stic plate 22, to a position in which the two ends of the end plates t are -aligned with the four notches 21 provided in the two lower edges of the bar 21, so that, the ends of the end plates 25, may pass through these n-otches 21 to engage against the internal surface of the bar 2 I. Upon relea-sing the hook 28, the elastic plate 22 returns the bar 2 i, with the lower bent edges of the bar sliding freely in the notches 21A of the end plates 20, so that the movable core 25-26 remains thus suspended from, or locked to, the bar I The niovable core 25, 26, when thus locked to the bar 2 I, serves to prevent the insulating blocks 32, that support the sel-f-adjusting pole pieces 24, from being rem'oved from their seats, and also to retain the coil 29 in its place. To remove the coil, it is necessary to disconnect the movable core, by depressing the hool: 28 until the notches 2? of the bar 28 are again aligned with the two end plates of the movable core so that the latter may be withdrawn to permit the coil to be removed from the fixed core.

If it is necessary to provide the remote operated switch with an auxiliary self-sealing contact, the assembly heretofore described has added to it, in the insulating blocks set in the lower corners of the end plates of the fixed core, the contactclamps 313 complete with all their parts for the coupling of the wire terminais El and, in the lower part of the movable core 25-26, the blocks 38, and the movable ccntact-clamp 3.5). If it is necessary to provide auxiliary contacts, the contactclamps Z are placed in the spaces i between the plates i, before introducing the pairs of the refractory plates i which serve to secure them in place.

The rernote operated switch is then ready to operate. When the coil is energized, the movable core is attracted upwards, and, by consequence, it pushes the bar fi until it presses the rods i against the lower part of the roliers 6 of the contact-clamps CM.

If lower contacts are rnounted on the device, in the backward stroke towards their lower positions, the rods i close the contact against the corresponding -contact-lclamps M-fil and press, in the last portion of the strolre, upon the contact di.

From the foregoing description of preferred embodiments, it is apparent that the present invention provides a double-break switch of multiple element construction wherein: rihe electro-magnet can always be mounted centrally on the supporting frame without requiring a special frame or casing for each of the assemblies having different numbers of contacts.

The movable armature or core can be fiXed to or removed from the contact-carrier bar without difiiculty and without the use of any tools.

The arrangenent of the parts provides the possibility of connecting to the supporting frame two or more electro-magnetas working in parallel, if it is necessary to use a large number cf simultaneously operated contacts.

The fixed contact-clamps CM and the movable contact rods (which need inspection and maintenance as they are subject to natural wear), are easily reniovable and replaced by withdrawing the contact clainps CM from their respective seats.

The possibility, in case of wear of the roller i of the fixed clainps CM, of rotating the roller through a small angle, in order to present, at the contact point, a non-used part; so that, as the roller can be partly rotated several times before having used it ail around its circumference, it insures a very long working life to the fixed contacts, and, likewise, the movable contacts can be reversed and used on both faces, as they are formed by bars, rectangular in cross section; so that, in effect several spare contacts are provided within the switch itself.

Connection of the wires of both main and auxiliary circuits by means of wire terminais, which are held by Spring pressure in contact-clamps to provide a secure physical and electrical connection without employing the usual tightening SCI'GWS.

The possibility of adding auxili'ary contacts ini the hollows provided between the plates i of the device is present without requiring modification or increase of the overall dimensions.

The essential parts of the device to be inspected are bound together only by the order of assemblage and their own interlocking construction and are free to positionally adjust theinselves relative to each other so that the assembling and the good working of the device, and also the inspectance of the different parts, requiring normal maintenance, is facilitated and is possible without requiring the use of tools.

While preferred illustrative embodiments have been shown and described in detail, it is to be understood that the present invention is not limited to those precise embodiments and that many changes and modications, obvious to one skilled in the art, may be effected therein without depart from the scope or spirit of the invention which is intended to be defined in the appended claims.

What is claimed is:

1. A multiple switch comprising a plurality of superposed switch contact assemblies, each of said assemblies including a pair of substantially rectangular insulating plates each having recesses at the opposite faces of the corners at one side thereof so that series of corner spaces are defined at said one side between the confronting faces of each of said pairs of plates and between the meeting faces of the plates of adjacent switch contact assemblies, an electro-magetic Operating device including a fixed core formed with a pair of supporting ears located at each of the opposite ends of one side thereof and spaced apart a distance substantially equal to twice the distance between successive ones of said corner spaces so that said ears may be received in selected ones of said corner spaces to position said core centrally relative to the superposed switch contact assemblies, securing bolts extending through said corners of the plates for securing together the latter and for holding said fixed core to the superposed plates, fixed contact means having means thereon engageable with detent means on said insulating plates for removably mounting said fixed contact means between each of said pairs of insulating plates, refractory means held between each of said pairs of plates by the associated fixed contact means and defining arcing chambers at each of the latter, movable contact means disposed between each of said pairs of plates and extending into said arcing chambers for contact with said fixed contact means, inovable contact carrying means including a common actuating member for simultaneously moving the movable contact means of each of said switch contact assemblies, a coil removably mounted in said fixed core, a movable core linearly slidable in said fixed core and said coil, and interfitting means on said core and said common actuating means separably connecting said movable core to said common actuating member.

2. A multiple switch according to claim 1; wherein each of said fixed contact means includes a contact member, a pair of spaced conducting plates extending from the opposite ends of said contact member, the confronting faces of said insulating plates having grooves Opening at a side thereof to slidably receive and guide said conducting plates during insertion of the latter' between said insulating plates, a pin extending between said conducting plates, a pressure disc slidable on said pin, and a coil Spring on said pin aciaoes and interposed between said disc and one of said conducting plates for urging said disc against the other of said conducting plates so that a terminai plug may be removably engaged between said spring urged disc and said other conducting plate for electrical connection to the related contact member.

3. A multiple switch according to claim 2; wherein said xed contact means further includes a bearing plate slidable on said pin between said coil spring and said other conducting plate, said bearing plate being formed With ears projecting laterally past the side edges of said other conducting plate; and wherein the insulating plate adjacent said other conducting plate is formed with projections adjacent the edges of the groove therein to engage behind said projecting ears of the bearing plate for holding said fixed contact means between said insulating plates.

4. A multiple switch according to claim 1; wherein said confronting faces of the pairs of insulating plates have right angularly related grooves formed therein and opening at the side remote from the said fixed core and at sides disposed substantially at right angles to said remote side, said fixed contact means being slidably received in said grooves opening at said remote side and said refractory means being slidably received in said grooves Opening at said right angularly disposed sides, each of said refractory means including a hollow box-shaped member having an Opening in the direction facing toward the related fixed contact means, each of said fixed contact means including a contact member extending into said box-shaped member of the related refi'actory means through said opening thereof so that said contact member prevents withdrawal of said box-shaped member from between said insulating plates, and interengageable looking means on said fixed contact means and on one of said insulating plates for preventing withdrawal of said fixed contact means from the latter 5. A multiple switch according to claim 1; wherein each of said fixed contact means includes two laterally spaced fixed contact members located adjacent the corners of said insulating plates remote from said recessed corners of the latter, and said movable contact means include bars of conducting material extending laterally between the related pair of insulating plates and movable towards and away from the related laterally spaced fixed contact members; and wherein said movable contact carrying means includes a bar support member for each of said movable contact means slidable linearly between the related pair of insulating plates in the direction toward and away from said fixed contact members, said bar support member Opening laterally to slidably receive the associated contact bars and having a through Opening at right angles to said contact bars for slidably receiving said common actuating member.

6. A multiple switch according to claim 5; wherein said common actuating member includes an elongated channel of C-shaped cross-section Opening in the direction toward said fixed core, and said means for separably connecting said movable core to said common actuating member includes extensions formed on said movable core to extend into said channel and having laterally opening notches at the sides thereof to slidably receive the edge portions of said channel, the edge portions of said channel having notches therein registering with said extensions in one longitudinal position o-f said common actuating member to permit separation of the latter from said extensions of the movable core, resilient means acting on said common actuating means for yieldably urging the latter to a longitudinal position in which said notches of the channel are out of registration with respect to said extensions, and an Operating member on said common actuatng member and extending out of the uppermost of the superposed pairs of insulating plates to provide for manual displacement of said common actuating member to the first mentioned longitudinal position.

7. A multiple switch according to claim 6,; wherein said fixed core is substantially rectangular and defines a central space open at the end remote from the superposed pairs of insulating plates and at its opposite sides, said coil fitting into said central space through either of said open opposite sides of said fixed core and having an open ended longitudinal passageway extending centrally therethrough to register with said open end of said fixed core when said coil is disposed centrally in the latter, and stop means on said coil engageable with said fixed core to position said coil centrally in the latter, said movable core extending slidably through said open end of the fixed core and through said longitudinal passageway of the coil to prevent removal of said coil from said fixed core so long as said movable core is connected to said common actuating member.

PAOLO SALA.

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

UNITED STATES PATENTS Number Name Date 2,071,149 Wilms et al Feb. 16, 1937 2,172,633 Wilms Sept. 12, 1939 2,22'7,434 Bierenfeld Jan. 7, 1941 2,239,031 Bierenfeld et al Apr. 22, 1941 2,283,795 Dahl May 19, 1942 2,411,894 Peters Dec. 3, 1946 2,434,096 Ayers et al Jan. 6, 1948 2,-514,913 Tyrner July 11, 1950

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