US 3603755 A
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United States Patent  Inventor Pierluigi Ranzanigo 2,859,302 11/1958 Schleicher... 335/132 Via Violino di Supra 67, Brescia, Italy 2,884,499 4/1959 Weber 335/132 X  App1.No1 814,667 2,684,417 7/1954 Cole et al 200/144  Filed Apr. 9, 1969 2,932,706 4/1960 Bodenschatz ZOO/153.7 X  Patented Sept. 7, 1971 3,043,939 7/1962 Gryctko et al. 200/144  Pnonty Apr. 13, 1968 3,430,014 2/1969 Walters et al... 200/144  Italy I 3,441,697 4/1969 Wingard 200/144 1 829866/68 3,448,231 6/1969 l-left 200/144 Primary Examiner-David Smith, Jr. Assistant Examiner-William J. Smith [541 POWER ELECTRIC SWITCH Attorney-Michael S. Striker 8 Claims, 7 Drawing Figs.
U.S. G, An electric witch comp ising a trip mechanism 335/132 including tiltable contact elements, support means for the lilt- Mable onta t element and operating means for the latter 3/46 connected to each other to form a single unit which is inserta-  Field of Search ZOO/153.7, ble through the open end f a housing into the latter to cooperate with stationary contacts in the bottom wall of the housing, and the latter is provided with a cover for closing the  Rem-ewes cued open end. The cover is formed with an opening through which UNlTED STATES PATENTS one end portion of the operating means extends in a sealed 2,348,228 5/1944 Scott 335/132 X manner when the trip mechanism is inserted in the housing.
I 83 do 76 l I I I L 83 72 I" 7 22 I l E 7 k 1 a4 H: '41 73 a "QL L :'L\. 65 2' Lt a. 62 3 7 g 64 i 66 PATEHTEB SEP 7 1971 SHEET 2 [IF 6 I N VE NTOR. plruum 04111240160 BY (a)! f. If!!!- PATH-MUSE? 71911 3.603755 SHEET 3 OF 6 INV-NTOR. PIE! M061 M24016:
PATEI'HEU SEP 7 ISYi SHEET 6 OF 6 I I I Y 1 VENTOR. PIHMMG $44124 0167! M7 I M a M POWER ELECTRIC SWITCH This invention relates to a power electric switch.
An object of this present invention is to provide an electric switch, which while having the same capacity requires a smaller space than similar switches known in the art, yet maintaining unchanged the electrical characteristics as demanded for a good switch.
Another object of this present invention is to provide a switch equipped with a trip mechanism which is very simple in construction, such as to limit the amount of elements comprising said mechanism, in order to considerably reduce the manufacturing cost.
Still another object of this present invention is to provide a trip mechanism which along with the mobile contacts and terminals connected to said contacts, can be assembled before being inserted into the housing of said switch, thus simplifying the assembling operations and further in order that said mechanism thus assembled can be inserted into its housing in a simple and rapid manner.
A further object of this present invention is to provide a switch the housing of which is arranged so as to support the trip mechanism, and particularly the mobile parts of same without the necessity of ancillary elements.
' Still a further object of this present invention is to provide terminals consisting of small squares of electrically conductive material, which are very simple in construction, while allowing to fasten the lugs by means of iron bolts, thus further permitting a major saving in general cost.
Another object of this present invention is to have fastening screws for the means supporting the mobile parts of the trip mechanism, screws engaging with sleeves located in holes provided on the housing bottom, so that such sleeves will permit prompt fastening of the securing bolts of the switch to a supporting bar.
Still a further object of this present invention is to provide a cover for the housing, which cannot be removed by operating from the front part of the apparatus.
In order to reach the aforesaid objects, the trip mechanism of the switch according to this invention comprises a stationary supporting means and a mobile element both connected each other by means a toggle-type trip kinematic mechanism, wherein said supporting means and said mobile element are made from insulating material, said mobile element comprising parallel arms equipped with seats wherein the mobile contacts are located, each one forming a single piece so that the opening or closing of said mobile contacts take places following the displacement of said mobile element.
The mobile contacts are directly connected with terminals, which project from the rear portion of the housing.
The supporting means for the mechanism, the mobile element, the mobile contacts and the terminals therewith connected can be preassembled with the kinematic mechanism and the control lever externally of the apparatus and in such a state inserted into said housing.
For this purpose, housing and supporting means of the trip mechanism are provided with guiding coupling means which allow the accurate introduction of the entire unit into said housing.
The mobile element comprises a shaft rotating in round seats composed by the coupling of the supporting means and proper walls provided within said housing.
In order to fasten the supporting means of the trip mechanism, use is made of two screws each one compressing a small bridge connecting the consecutive walls of said supporting means and of said housing, each single screw engaging into a sleeve mounted in the housing bottom and open at the rear face thereof in order to allow engagement of a bolt thereinto. In this manner, said sleeve may be used for the engagement of bolts with the purpose to directly set the apparatus onto a supporting bar, thus preventing any intermediate fastening means.
The stationary contacts of the apparatus are connected to terminals, each arranged in a deionization chamber, known in the art and provided for extinguishing the opening arc.
The terminals in the projecting rear part of the apparatus are each provided with a hole wherein a fastening bolt for the lugs is engaged of a respective lead. In this instance, since said bolt has not a conductive purpose, said bolt may be made from iron, thus allowing a major saving in cost,
The cover which closes the switch housing is secured by means of screws entering from the rear portion of said unit, in such a manner so that said unit cannot be removed from the front part of the housing.
Terminals are separated by appropriate removable insulating walls, which are located in such a manner so that the terminals may be arranged close to each other.
One embodiment of this invention, is illustrated by a nonlimiting example example of execution of this present invention, detailed in the accompanying drawings, where:
FIG. 1 shows in exploded view the several parts comprising the trip mechanism, said parts being assemblable before being located into the switch housing;
FIG. 2 is a perspective view with parts removed, and showing the housing arranged for receiving the mentioned trip mechanism of FIG. 1;
FIG. 3 shows in perspective view and with parts removed the trip mechanism during its introduction into said housing, and in exploded view the control lever of the said mechanism, along with housing cover;
FIGS. 4 and 5 show, respectively, in axial cross section and in transversal section the apparatus in assembled operating position;
FIG. 6 shows in detail the fixing system of the cover and the supporting means for the trip mechanism;
FIG. 7 shows the exterior of the switch housing in its completed state.
Referring now more particularly to FIG. 1, the trip mechanism of the switch, object of this present invention, comprises an element 1 substantially constituted by a shaft 2 from which three arms 4, 5 and 6 (i.e. three in the case of a three-phase switch, or only two in the case of a single-phase switch) extend. Each of said arms is provided with a cutout at its bottom face in order to provide a seat 7 wherein a metal contact 8 is housed which can slightly oscillate with respect to said seat on a bolt 9 at the rear portion thereof, which is supported by lateral walls of said seat means 7, against the bias of a spring 10 placed forwardly of the bolt 9, and located between said contact and a small cavity provided at the bot tom of said seat 7. There is to be observed from FIG. 1 the simplicity of contacts 8 and 9 of element 1, which serves to support them, and the simplicity by which said contacts can be A l assembled on said element 1.
Element 1 is connected to a supporting means 11 through a toggle mechanism comprising two small connecting links 12 and 13, arranged parallel, and to opposite sides of the center arm 5 of the supporting element 1, hinged onto a comnlion pin 14. Both of said connecting links 12 and 13 are at the opposite end hinged onto a pin 13 on which the spread ends 16 and 17 of a second small connecting link 18 are mounted. The rear end of link 18 constituted by two facing and close parts, comprises a half-round seat 19 which is pressed against a pin 20 passing through a slot 21 of a lug 22 provided onto the supporting means 11.
Two vertical walls 23 and 24 are vertically provided onto at opposite sides of said lug 22, which walls are integral with the supporting means 11 and are provided internally with two seats 25, respectively 26, with to receive the arms 25', respectively 26' of a stirrup 27. The ends of the arms 25' and 26' being externally provided with pins 28, respectively 29, arranged to be inserted in the respective guiding means 28' and 29', provided within seats 25 and 26, and showing a rounded bottom in order to act as supporting means for said pins 28 and 29.
Stirrup 27 comprises two springs 30 and 31 directed downwards between said two arms 25 and 26' and securable at their upper ends to the crosspiece portion of said stirrup by means of a small pins 32 and 33, the purpose of which is to prevent movement of the spring lugs through respective holes 32' and 33' provided in the crosspiece of said stirrup.
The free ends of springs 30 and 31 are reserved to engage with the projecting ends and 15" of pin 15 of toggle piece.
After inserting of stirrup 27 into seats and 26 till said pins 28 and 29 have reached the rounded bottom of said guiding means 28' and 29', springs 30 and 31 are connected to the ends 15' and 15'', so that connecting link 18 will be pressed against pin 20, while the rounded portion 2 of element 1 will be pressed against the half-rounded seats 34, respectively 35, provided in the bottom faces of walls 23 and 24.
Thus the assembling of the several elements described and shown in FIG. 1 may be effected externally of a housing, by very simple and fast operations.
The mobile contacts 8 are connected by means of conductive strands 36 to terminals 37, formed by small angle members of electrically conductive sheet material, for instance copper or a conductive alloy. Each terminal 37 has an upper threaded hole 38 for engagement of a screw to fasten them to the housing, or a lower hole 39 to permit passage of a bolt.
Supporting means 11 shows, on two opposite sides, two short vertical ribs 40 and 41, serving to guide said supporting means during the insertion into the housing. In the same manner, parallel walls 23 and 24 show on their vertical edges, ribs 42, respectively 43, also for guidance and fastening purpose.
FIG. 2 shows the housing 44 for receiving the mechanism of FIG. 1. To this end, said housing shows two opposed ribs 45, of which only one is represented, the purpose of which is to engage with the grooves 40 and 41 of said supporting means 1 1, said ribs 45 showing at their lower portion shoulder means 45 serving to position the lateral parts of said supporting means at a suitable level internally said housing.
Within said supporting means are provided two vertical and parallel walls 46 and 47, the purpose of which is to act as partition walls in order to separate the strands and the terminals connected thereto, thus showing at the front portion grooves 46', respectively 47', whereinto engage said ribs 42 and 43 supported by the walls of the supporting means 11, said coupling being shown in more details in FIG. 3.
Shoulders 48 and 49 are arranged on the front portions of the walls 46 and 47, each one of the former provided being with a half-round seat 50 wherein shaft 2 of the element 1 rests, thus enclosed by seats 50 and seats 34 and 35, and an upper groove 51 is provided in each of said shoulder pieces 48 with the purpose to receive a respective rib 52 or 53 provided on walls 23 and 24, respectively.
There is thus possible to insert the supporting means into the switch housing 44 by simply guiding it along ribs 45 and grooves 46 and 47 pressing it downwards till shaft 2 will rest onto seat 50 and ribs 52 and 53 will rest in grooves 51.
Mobile element 1 and supporting means 11 are fabricated by integrally moulding the same from insulating material. Ac cording to this invention, there is proposed to use as material for both said elements a (FIGS. and particularly a polycarbonate by Bayer, since this material maintains good mechanical properties up to a temperature of 150-160 C., also when filled or not with glass, a polycarbonate sold under the trademark Makrolon and which has also very good electrical insulation properties.
Once the supporting means 11 has been fixed in place, it is also fastened to the housing by means of a pair of screws 54 (FIGS. 2, 3 and 6), of which only one is shown. Each screw 54 is inserted into a cylindrical seat 55 obtained by two facing parts, properly shaped of supporting means 11 and partition walls 56 and 57 provided in vertical position within said housing. The upper portion of seats 55 are enlarged in order to form two opposed ribs 58 and 59, between which the feet of a small bridge 60 fastened by each screw 54 are positioned, said bridge serving to anchor the supporting means 11 to the said housing.
As it is best shown in FIG. 6, screw 54 extends downwards in order to screw onto a ring nut 61 which opens on the rear wall of bottom 62 of the housing, so that screw 54, besides of fastening said supporting means 11, serves further to mechanically retain said ring nut 61. A robust anchoring means, for instance for bolt 63, may be threaded into the nut 61 which permits the direct assembling of the apparatus onto a supporting bar, without any intermediate means.
Stationary contacts 64 (FIGS. 2 and 4) are enclosed in the housing 44 on the bottom wall in a position opposed to the mobile contacts 8. Said stationary contacts 64 are constituted by conductive metal angular elements, or by electrical conductive metal alloy, such that one arm 65 of said elements extends from the housing bottom to provide a respective terminal. In this manner a single metal piece has the dual purpose of stationary contact and of terminal, contrasting with the traditional solution of the prior art, whereof there were provided conductive bolts anchored in place and welded to the stationary contact, thus requiring set nuts for connecting the lugs, and themselves of conductive materials. Terminals according to this invention, on the contrary, besides to eliminate the assembling operations and welding of said terminals onto the stationary contact, and further reducing and simplifying the assembling operations, permit the use of bolts 66 of iron which go through holes 67 and tightened by nuts 68, through the interposal of washers 69 and 70, also made of iron, inasmuch their purpose is only a mechanical one and not to conduct electricity. Similar arrangements are shown for terminals 37 connected to the mobile contacts by flexible conductors 36.
The stationary contacts 64 are disposed at the bottom of the deionization chamber 71 wherein a few blades, known per se, for interrupting the electric arc, are supported by a solid liner 72, for instance of insulating cardboard (FIGS. 2, 3 and 4), in order to substantially form a U-shaped piece. A perforated plate 73 is provided behind the rear wall of the liner 72 with the purpose to obtain a gap behind said rear wall. In such a manner, when said switch is opened, hot air and gases, which may be produced by the electric arc, are constrained to pass over the wall of the rear wall of the liner 72 and to go through said interval between said wall and said plate 73 to exit through the plate holes so as to cool down and to deionize before flowing to the exterior.
As shown in FIG. 4, the stationary contacts 64 and the terminals 37 are secured onto the bottom of the housing by means of screws 74 and 75, respectively, which are inserted from the bottom portion of said housing 44, by means of a very simple and rapid assembling operation.
Housing 44, as shown in FIGS. 3, 4 and 5, 6 and 7, is closed by means of a cover 76 shaped in a manner to comprise a peripherical wall 77 in registered position respect with the peripherical wall of housing 44. Said cover has at its upper portion a flat wall wherein at its intermediate part a window 78 is provided, from which a lever 79 extends outwardly from the control element 80. Said control element 80 (FIGS. 3 and 4) is provided with a curved surface. Packing means 82 of flexible quality, for instance rubber or plastic material of the sponge type, are interposed between the curved surface of element 80 and correspondingly curved surface portions along the window 78 with the purpose to close tightly the upper curved wall of the controlling element with respect to the edges of said window 78 while permitting the required oscillation of the lever during the movement of the switch lever.
The controlling element 80 engages the already mentioned stirrup 27, which to this purpose shows opposed projections 83 and 84, which enter corresponding cavities 83' and 84' at the bottom portion of said element 80. The compression imparted by the flexible packing 82, as cover 76 is closed, serves to maintain said controlling element 80 in place.
Cover 76 is fixed onto the housing 44 by means of screws 85 which enter the rear portion of said housing through slots 86 opened onto seats 87 whereon screw heads 85 can rest, said screws engaging sleeves 88 provided in the wall of said cover and of which the heads 89 are visible at the upper wall surface located, and in seats 90. Thus as the switch is set in place, said cover cannot be removed from the front portion of the switch, and in order to remove it will be necessary to disengage the switch, to get access to its rear portion. This of course represents a safety factor against possible injury.
Two upwards directed walls 91 and 92 are provided at opposite sides of window 78 to prevent undue handling of the lever 79.
Insulating walls 93 are inserted into grooves 86 (FIG. 6 and 7), and they project downwards so as to form partition walls between terminals 37 and terminal 75 at one and the other sides. Said walls 93 are enclosed under pressure and are locked by a small pin 94 which enters also under pressure a blind hole 95 provided to this end at the bottom 62 of housing 44.
The provision of said walls 93 between the terminals constitutes an insulating partition which permits to said terminals very near to each other, while eliminating any possibility of contacting between the wirings connected to said terminals.
This invention may naturally be executed in other manners and with other means differing from those hereinabove described and illustrated in the enclosed drawings, without departing from the spirit of said invention itself.
1. An electric power switch comprising a housing having a bottom wall and an open end opposite said bottom wall; two series of stationary contacts mounted on said bottom wall; a trip mechanism in said housing and comprising a mobile element of insulating material, a plurality of mobile elongated contact elements respectively substantially aligned with said series of stationary contacts and being mounted on said mobile element for limited tilting movement with respect thereto about a first axis, one-piece support means of insulating material supporting said mobile element for tilting movement about a second axis substantially parallel to said first axis, and operating means for tilting said mobile element about said second axis, said operating means comprising toggle means connected at one end to said mobile element and abutting with the other end against said support means, a single operating lever means mounted in said support means tiltable about a tilting axis substantially parallel to said first axis, and spring means connecting said operating lever means to said toggle means for yieldably holding the latter in a predetermined position, for holding said mobile element in engagement with said support means and for holding said other end of said toggle means abutting against said support means so that the latter together with said mobile element, said contact elements and said operating means form a single unit insertable and removable through said open end of said housing into the latter; and a cover connected to said housing for closing said open end, said cover being formed with an opening through which an end portion of said operating lever means extends.
2. A switch as defined in claim 1, wherein said mobile element comprises a plurality of arms, one for each mobile contact element and a shaft portion integrally with and extending transverse to said arms along said second axis and connecting said arms at one of the ends thereof, each of said arms having a bottom face provided with a cutout in which a respective one of said mobile contact element is arranged tiltable about said first axis, and including springmeans between said arms and said mobile contact elements for urging one end portion of each mobile contact element adjacent said second axis towards said bottom face of the respective arm. 7
3. A switch as defined in claim 2, wherein said support means comprises a plurality of first separating walls respectively arranged between said arms and each formed in a bottom face thereof with a half cylindrical seat for said shaft portion, said housing being provided with a plurality of second separating walls, each formed with a cutout for receiving said first separating walls and each also provided with a half cylindrical seat respectively complementary with the half cylindrical seat in said first separating walls;
4. A switch as defined in claim 3, wherein said first and second separating walls are provided with interfitting guide grooves and ridges.
5. A switch as defined in claim 3, wherein said operating lever means comprise a stirrup member having a pair of downwardly extending arms having at the lower ends thereof outwardly extending projections, and said first separating walls being provided with guide grooves having lower closed ends providing seats for said projections, said spring means being connected at opposite ends to said stirrup member and said toggle means and holding said projections against said seats at the lower ends of said guide grooves.
6. A switch as defined in claim 5, wherein said operating lever means comprise further a curved member connected to said stirrup member beneath said opening in said cover and having a central portion projecting through said opening, and including sealing means sandwiched between said curved member and the edges of said cover defining said opening.
7. A switch as defined in claim 2, wherein said one end portion of each mobile contact element is connected by a flexible conductor to a respective one of one of said two series of stationary contact elements and the other end portion of each mobile contact element being arranged opposite to a respective one of the other of said two series of contact elements movable in and out of engagement therewith during tilting of said mobile element.
8. A switch as defined in claim 1, wherein said mobile element and said support means are formed from polycarbonate.