SI7511726A8

SI7511726A8 - Two-parts electrically insulated lever of a railroad switch

Info

Publication number: SI7511726A8
Application number: SI7511726A
Authority: SI
Inventors: Robert Pirker
Original assignee: Voest Alpine Eisenbahnsysteme
Priority date: 1974-07-08
Filing date: 1975-07-03
Publication date: 1994-12-31

Description

Pronalazak se odnosi na polugu za pokretanje jezička za šinske skretnice, koja se sastoji od najmanje dva dela, koji se priključuju jedan na drugog i medusobno spajaju preko zavrtanja, pri čemu se ovi delovi na priključnom mestu uzajamno preklapaju i najmanje jedan deo poluge je savijen u području preklapanja i ima naslon, na koji se oslanja čeona strana drugog dela poluge.The invention relates to a lever for actuating a rail for a rail switch, which consists of at least two parts, which are connected to each other and connected to each other via a screw, wherein these parts at the connecting point are mutually overlapping and at least one part of the lever is bent in and there is a backrest, on which the front side of the second part of the lever rests.

Za pokretanje jezičaka za šinske skretnice primenjuju se izmedu ostalog i poluge, kao medusobno spajaju skretničke jezičke obe šine koloseka pomoču zatvaračkih kuka. Cesto je potrebno, da se obe šine električno izoluju jedna prema drugoj, da bi se mogla provoditi komanda strujna preko sina, pa se stoga primenjuju poluge, koje su podeljene u više delova, koji su medusobno spojeni umetanjem električne izolacije, tako da obe polovine uredaja sa jezičcima ostaju izolovane jedna prema drugoj. Kod poznatih poluga ove vrste, sastavljaju se medusobno pojedini delovi poluga umetanjem izolacionog sloja, koji je u pogledu položaja osiguran cilindričnom čivijom, pri čemu se krajevi delova poluge obostrano zahvataju spojnicama, koje se pomoču dva spojna zavrtnja spajaju sa svakim krajem poluge. Da bi se postigla električna izolacija mora da spojni zavrtnji koji zahvataju na jednom kraju poluge u otvore kraja poluge i obe spojnice, leže ispod umetnutih izolacionih čaura. Izmedu obe spojnice i kraja poluge mora biti predviden izolacioni medusloj- Glave i navrtke spojnih zavrtanja mora isto tako da budu izolovane preko izolacionog medusloja prema spojnicama. Da bi se pritisak ravnomerno rasporedio na ove izolacione delove, mora se opet predvideti zaštitne ploče, koje preko umetnutih izolacionih delova naležu na spojnice. Spojni zavrtnji leže horizontalno u skretnici i stoga debljina poluge na mestu sastavljanja odgovara ukupnoj dužini spojnih zavrtanja, koja se odreduje prema debljini krajeva poluge uključivo debljina dve spojnice, prema debljini dve zaštitne ploče i prema debljini četiri izolaciona umetnuta sloja kao i sigurnosnih limova za zavrtanje i navrtke.For switching the tabs for railroad switches, they are used, inter alia, by means of a lever, interconnecting the bushing tabs of both track rails with the help of locking hooks. It is often necessary to electrically isolate the two rails against each other so that the current can be actuated over the son, and therefore levers, which are divided into several parts, are connected, interconnected by inserting electrical insulation, so that both halves of the device with the tabs remaining isolated to each other. In the case of known levers of this type, individual parts of the levers are assembled by inserting an insulating layer, which is secured by a cylindrical jaw in respect of the position, the ends of the lever parts being grasped by the couplings, which are joined by two connecting bolts to each end of the lever. In order to achieve electrical insulation, the connecting screws that engage one end of the lever into the openings of the end of the lever and both couplings must lie below the inserted insulation sleeves. An insulation intermediate must be provided between both joints and the end of the lever - The heads and nuts of the connecting screws must also be insulated over the insulating intermediate to the joints. In order to distribute the pressure evenly to these insulating parts, protection plates must be provided again, which attach to the joints through the insulated parts inserted. The connecting screws lie horizontally in the crossover and therefore the thickness of the lever at the assembly point corresponds to the total length of the connecting screws, which is determined by the thickness of the lever ends, including the thickness of the two protective plates and the thickness of the four insulating inserts as well as the safety plates for screwing and nuts.

Poluga je kod modernih tipova skretnice smeštena u jednom koritastom pragu, čija širina korita ograničava širinu izolacionog mesta u horizontalnom pravcu. Da bi se postigla potrebna sigurnost protiv izvijanja, mora se kod ovih poznatih konstrukcija povečati višina poluge u području izolacionog mesta i u skladu sa ovim takoder i širinu spojnica po vertikali mereno, iznad normalne višine poluge, upravne na podužni pravac spojnih zavrtanja. Unutar tog koritastog praga spojen je zavrtnjima element za zatvaranje sa svakom čeljusnom šinom, koji ima otvor za prolaz poluge. Skidanje ovih elemenata za zatvaranje nije dozvoljeno prema železniškim propisima i zbog dimenzija mesta za izolaciju kod poznatih konstrukcija nije moguče provlačenje poluge kroz otvor elementa za zatvaranje. Kod poznatih konstrukcija moralo se stoga delove poluge posebno da uvodi u koritasti prag i da ih se unutar koritastog praga spoji medusobno. Ovaj montažni rad je s jedne strane težak i pravilna izrada ovog spoja nije obezbedena, pošto to mora da se vrši na radilištu. Poznate konstrukcije poluga imaju stoga često za posledicu, što na izolacionom mestu dolazi do izvijanja, koje dovodi u pitanje pravilnu funkciju poluge i time pravilno naleganje skretničkih jezičaka na čeljusnu sinu i može da ima za posledicu smetnje u radu. Dimenzije koritastog praga i elemenata za zatvaranje, medutim ne mogu se menjati, pošto su iste normirane i sa odredenom funkcij om, bez obzira na to, što se mora ugradivati i izolovane poluge u več postoječe skretnice i one koje se nalaze u radu. Več je bilo takode predloženo, da se dva dela poluge na njihovom kraju prema sredini koloseka izvedu sa navojem zavrtnja koji je na istoj osi sa delovima poluge. Pri torne se oba dela poluge uvrnu u naglavak, koji se sastoji od više delova, koji su električno izolovani jedan prema drugom. Kod jedne takve konstrukcije, kada spoj zavrtnjem treba da bude čvrst na izvijanje, mora se odabrati znatno velik prečnik naglavka, tako da ponovo prečnik ovog naglavka zadaje poteškoče, a pored toga ovakav spoj je skup i komplikovan, pa stoga nije dorastao zahtevima u grubom železničkom saobračaju.In modern types of levers, the lever is housed in a single trough, whose trough width limits the width of the insulation point horizontally. In order to achieve the necessary anti-twist safety, the height of the lever in the area of the insulation must be increased in these known structures and, accordingly, also the width of the joints vertically measured, above the normal height of the lever, directed to the longitudinal direction of the connecting screws. Within this trough, a closing element is connected by screws to each jaw, which has an opening for the passage of the lever. Removal of these closing elements is not permissible according to railway regulations and due to the dimensions of the insulation points in known structures it is not possible to push the lever through the opening of the closing element. In the known structures, therefore, the parts of the lever had to be introduced separately into the trough and to be connected to each other within the trough. This assembly work is difficult on the one hand and proper construction of this joint is not ensured, as it must be done at the work site. Known lever designs therefore often result in a twist in the insulation site, which compromises the proper function of the lever and thus the proper attachment of the cuffs to the jawbone and can result in malfunctioning. The dimensions of the trough and the closing elements, however, cannot be changed, since they are standardized and with a specific function, regardless of which insulated levers must be installed in already existing switches and those in operation. It has already been suggested that the two parts of the lever at their end towards the center of the track be made with a screw thread which is on the same axis with the parts of the lever. In the case, the two parts of the lever are screwed into an upright consisting of several parts, which are electrically isolated to each other. In such a construction, when the screw joint is to be rigidly twisted, a substantially large diameter of the sleeve must be selected, so that the diameter of this sleeve again causes difficulties, and in addition such a joint is expensive and complicated, and therefore does not meet the requirements of rough railway traffic.

Pronalazak polazi od poluge za pokretanje jezičaka za šinske skretnice, koja se sastoji od najmanje dva dela, koji se priključuju jedan na drugog i medusobno spajaju preko zavrtanja. Delovi poluge se na priključenom mestu uzajamno preklapaju i najmanje jedan deo poluge je savijen u području preklapanja i ima naslon, na koji se oslanja čeona strana drugog dela poluge. Ovo se može videti iz GB—PS 515 486.The invention starts from a lever for actuating the tabs for rail crossovers, which consists of at least two parts, which are connected to each other and connected to each other via a screw. The lever portions overlap at the attached site and at least one lever portion is bent in the overlap area and has a backrest on which the front side of the other lever portion relies. This can be seen from GB — PS 515 486.

Pri torne je osnova pronalaska, da dalje razvije polugu u pravcu, da se ona može koristiti i tada, kada treba provoditi električne komandne struje preko sina, a radi sigurnosno tehniških cilj eva. Pri torne konstrukcija treba da omoguči jednostavno izvodenje izolacije delova poluge jedan rpema drugom, a da se pri tom ne naškodi osobinama čvrstoče poluge.The basis of the invention is to further develop the lever in the direction that it can be used even when it is necessary to conduct electric command currents through the son for safety and technical purposes. In the case of the structure, the insulation of the parts of the lever should be easy to perform with one another without damaging the properties of the lever strength.

Rešenje zadataka prema pronalasku sastoji se u torne, što su oba dela poluge na poznati način spojena umetanjem električne izolacije, pri čemu su spojni zavrtnji na poznati način obuhvačeni izolacionim čaurama od veštačke smole; što je izolacioni sloj izveden na licu mesta od veštačke smole koja se otvrdnjava; što izolacione čaure imaju prirubnicu, čija debljina odgovara debljini izolacionog sloja, a deo poluge, izolovan izolacionom čaurom prema zavrtnjima, je u području mesta preklapanja spolja pokriven metalnom zaštitnom pločom uz umetanje izolacionog sloja; što zaštitna ploča ima otvore za spojne zavrtnje, čiji prečnik odgovara prečniku zavrtnja i što je duži— 37 289 — na izolacione čaure, ne uzimajuči u obzir njezinu prirubnicu, veča za debljinu izolacionog sloja izmedu zaštitne ploče i dela poluge, od debljine dela poluge, na mestu preklapanja i merene u podužnom pravcu zavrtnja.The solution of the invention according to the invention consists in towers, which are both known parts of the lever connected in a known way by inserting electrical insulation, wherein the connecting screws are in a known manner enclosed by artificial resin bushes; which is an on-site insulating layer of artificial curing resin; the insulation sleeves having a flange the thickness of which corresponds to the thickness of the insulating layer and the part of the lever insulated by the insulating sleeve according to the screws is covered in the area of the overlap area with a metal protective plate by inserting an insulating layer; the protective plate having openings for connecting screws, the diameter of which corresponds to the diameter of the screw and longer - 37 289 - to insulating sleeves, not considering its flange, greater by the thickness of the insulating layer between the protective plate and the lever part, than the thickness of the lever part, at the point of overlap and measured in the longitudinal direction of the screw.

Time, što su oba dela poluge spojena uz umetanje električne izolacije ,mogu se preko sina provoditi komandne struje. Takve komandne struje, u slučaju da poluga nije razdvojena izolacijom, mogu biti kratko spojene. Time pak, što je izolacioni sloj izveden »in situ« od veštačke smole koja se otvrdnjava, dobija se prednost u odnosu na primenu umetaka od ploča veštačke smole, što se izolacioni sloj s jedne strane prilagodava neravninama spoljašnje površine i stoga se ne mora obradivati spoljašnje površine na mestu preklapanja i s druge strane prednost, što se koristi i dejstvo lepljenja veštačke smole. Obe prednosti ispoljavaju se u povečanju čvrstoče spojnog mesta i time u povečanju sigurnosti proti v izvijanja Takav sloj veštačke smole otvrdnute »in situ«, izraduje se na jednostavan način nanošenjem lopaticom veštačke smole koja se otvrdnjava, na odgovarajuča mesta delova poluge i time, što izolacione čaure imaju prirubnicu, čija debljina odgovara debljini izolacionog sloja, pri stezanju delova poluge obrazuje se zazor, u kome se veštačka smola nanešena lopaticom, može rasporediti ravnomerno.By connecting the two parts of the lever with the insertion of electrical insulation, command currents can be passed through the son. Such command currents, in the event that the lever is not separated by insulation, may be short-circuited. In that the insulation layer is made in situ from an artificial resin that hardens, it has the advantage over the use of inserts of artificial resin plates, which on the one hand adapts to the unevenness of the outer surface and therefore does not have to be processed externally surfaces at the point of overlap on the other hand advantage, which is also the effect of gluing artificial resin. Both advantages are manifested in increasing the strength of the coupling point and thus in increasing the safety against twisting. Such a layer of artificial resin hardened in situ is simply made by applying an artificial resin hardening trowel to the corresponding places of the lever parts and thus insulating the sleeves have a flange the thickness of which corresponds to the thickness of the insulating layer; when clamping parts of the lever, a gap is formed, in which the artificial resin applied by the trowel can be distributed evenly.

Time, što je u području mesta preklapanja deo poluge koji je izolovan prema spojnim zavrtnjima preko izolacionih čaura, spol j a pokriven metalnom zaštitnom pločom, koja ima otvore za spojne zavrtnje, čiji prečnik odgovara prečniku zavrtnja, i time, što je dužina izolacione čaure, ne uzimajuči u obzir njezinu prirubnicu, veča za debljinu izolacionog sloja izmedu zaštitne ploče i dela poluge, na mestu preklapanja i mereno u podužnom pravcu zavrtnja, nije samo pak definisan prirubnicom zazor izmedu zaštitne ploče i dela poluge preko isturenog dela izolacione čaure. Takode i u ovom zazoru, stoga se pri stezanju zavrtnja ravnomerno rasporeduje veštačka smola nanešena lopaticom i postiže sigurna izolacija. Kod ove konstrukcije je takode odreden tačno definisan zazor izmedu naslona savijenog jednog dela poluge i čeone površine drugog dela poluge, u koji se može utisnuti veštačka smola nanešena lopaticom, tako da je čeona površina drugog dela poluge, umetanjem izolacionog sloja oslonjena na naslon savijenog dela poluge.By the fact that in the area of the overlapping part of the lever which is insulated according to the connecting screws through the insulating sleeves, the floor is covered by a metal protective plate having openings for the connecting screws whose diameter corresponds to the diameter of the screws, and thus, the length of the insulating sleeve is not given its flange, the thickness greater than the insulating layer between the protective plate and the lever portion, at the point of overlap and measured in the longitudinal direction of the screw, is not only defined by the flange gap between the protective plate and the lever portion over the projecting portion of the insulating sleeve. Also in this gap, therefore, when tightening the screws, the artificial resin applied with a spatula is evenly distributed and a secure insulation is achieved. In this construction, a well-defined gap is also provided between the backrest of the bent part of the lever and the front surface of the second part of the lever, into which an artificial resin can be imprinted with a trowel, so that the front surface of the second part of the lever, by inserting an insulating layer, rests on the backrest of the bent part of the lever .

Takva konstrukcija u kombinaciji sa ostalim odlikama, daje dalje povečanje čvrstoče spoja, pri čemu je izolacija izmedu oba dela poluge izvodljiva na jednostavan način i cela poluga ima čvrstoču potrebnu za pogonsku sigurnost. Spoj delova poluge može biti več prethodno izveden, pošto takva poluga može biti u pravcu upravnom na ose spojnih zavrtanja tako dimenzionisana, da više nije sprečeno provlačenje kroz otvor elementa za zatvaranje.Such construction, in combination with other features, further increases the strength of the joint, whereby the insulation between the two parts of the lever is easy to perform and the entire lever has the strength required for operational safety. The connection of the lever parts may already be pre-made, since such a lever may be in a direction perpendicular to the axis of the connecting screws so dimensioned that it is no longer prevented from passing through the opening of the closing element.

Postiže se dakle smanjenje dimenzija delova poluge u pravcu upravnom na ose spojenih zavrtanja, pri kome se ipak postiže potrebna čvrstoča na izvijanje, i stvara se poluga, kod koje su njezini delovi na jednostavan način i pouzdano izolovani jedan prema drugom.Thus, the dimensions of the lever parts are directed in a direction perpendicular to the axes of the connected screws, but at the same time the required tensile strength is achieved, and a lever is created, in which its parts are simply and reliably isolated from each other.

Dalje se detaljnije opisuju primeri izvodenja prema pronalasku, na bazi priloženih crteža.Further examples of the invention according to the appended drawings are described in more detail.

Prikazuj u:Display in:

Sl. 1 i 2 celokupan smeštaj koritastog praga, šina i dvodelne poluge koja je izvedena na poznati način, pri čemu sl. 1 predstavlja presek po liniji I — I na sl. 2, a sl. 2 horizontalnu projekciju celokupnog smeštaja;FIG. 1 and 2, the entire arrangement of the trough sill, rails and two-piece lever which is designed in a known manner, wherein FIG. 1 is a cross-section along line I - I in FIG. 2, and FIG. 2 horizontal projection of the whole accommodation;

Sl. 3 4 dvodelnu polugu prema pronalasku, pri čemu sl. 3 predstavlja bočni izgled a sl. 4 horizontalnu projekciju;FIG. 3 shows a two-piece lever according to the invention, wherein FIG. 3 is a side view and FIG. 4 horizontal projection;

Sl. 5 i 6 mesto spajanja delova dvodelne poluge prema sl. 3 i 4, u povečanoj razmeri, pri čemu sl. 5 predstavlja bočni izgled, a sl. 6 horizontalni presek po liniji VI — VI na sl. 5;FIG. 5 and 6 show the connection point of the two-piece levers according to FIGS. 3 and 4, in an enlarged manner, wherein FIG. 5 is a side view, and FIG. 6 is a horizontal cross-section along line VI-VI in FIG. 5;

Sl. 7 izolacionu čauru, iFIG. 7 insulating sleeve, i

Sl. 8 i 9 mesto spajanja jednog drugog primera izvodenja dvodelne poluge, pri čemu sl. 8 predstavlja bočni izgled, a sl. 9 horizontalan presek po liniji IX — IX na sl. 8.FIG. 8 and 9 show the connection point of another embodiment of a two-piece lever, wherein FIG. 8 is a side view, and FIG. 9 is a horizontal cross-section along line IX-IX in FIG. 8.

Sl.l i 2 prikazuju celokupan smeštaj koritastog praga 22, u čijem koritu 23 je smeštena poznata dvodelna poluga 21, i na kome su učvrščene čeljusne šine 24, dok su jezičci 25 skretnice klizno vodeni na osloncima 26 za šine. Sa čeljusnim šmarna 24 spojeni su zavrtnjima elementi 27 za zatvaranje, koji imaju otvore 28 za prolaz dvodelne poluge 21. Višina otvora 28 za prolaz dvodelne poluge 21 je manja od višine izolacionog mesta 29 kod ove poznate dvodelne poluge 21. Pošto se prema propisima željeznice ne sme skidati elemente 27 za zatvaranje, a pored toga bi bilo i teško skidanje elemenata 27 za zatvaranje, to bi se kod ovog poznatog izvodenja moralo obe polovine dvodelne poluge 21 u nesastavljenom stanju uvlačiti iznutra kroz otvore 28 i vršiti spajanje obe polovine dvodelne poluge 21, odnosno izvodenje izolacionog mesta 29 unutar korita 23 koritastog praga 22. Takvi radovi na licu mesta su teški i nedovoljno precizni.FIGS. 1 and 2 show the entire accommodation of the sill threshold 22, in whose trough 23 is housed a known two-piece lever 21, and on which the jaw rails 24 are fixed, while the tabs 25 of the crossover are slidably guided on the rails 26. The locking members 24 are connected by screws to the closing elements 27, which have openings 28 for the passage of the two-piece lever 21. The height of the opening 28 for the passage of the two-piece lever 21 is less than the height of the insulation point 29 of this known two-piece lever 21. may remove the closing elements 27 and, in addition, it would be difficult to remove the closing elements 27, in this known embodiment, both halves of the two-piece lever 21 must be pulled inwardly through the openings 28 through the openings 28, and joining of both halves of the two-piece lever 21. that is, the construction of the insulation site 29 within the trough 23 of the trough threshold 22. Such on-site work is difficult and not precise enough.

Sl. 3 i 4 prikazuju dvodelu polugu 1 prema pronalasku, koja se sastoji od dva dela la, lb, i koja ima uobičajene zahvatače 3 za kukasto zatvaranje i zahvatna mesta 4 za pogonske elemente za zatvaranje, kao izolaciono mesto 5.FIG. 3 and 4 show a two-piece lever 1 according to the invention, which consists of two parts 1a, 1b, and which has the usual hooks 3 for the hook closure and the grips 4 for the drive closing elements, as an insulating point 5.

Na sl. 5 i 6 je u povečanoj razmeri prikazano izolaciono mesto 5. Deo la dvodelne poluge 1 je na mestu 6 preklapanja savijen tako da obrazuje naslon 7, dok je drugi deo lb prav i ima samo — 37 289 — ispust 8 sa naslonom 9. Oba dela la, lb su medusobno čvrsto spojeni zavrtnjima 10 sa navrtkama 11, pri čemu je ispod glave zavrtnja i ispod navrtke 11 umetnut po jedan čvrst podemtač 11 a. Otvori 12 u delu lb imaju prečnik, koji odgovara prečniku spojnih zavrtanja 10. Otvori 13 u delu la imaju veči prečnik, tako da je ovde izmedu zavrtanja fO i otvora 13 umetnuta izolaciona čaura 14 od veštačke smole, koja, kao što sl. 7 prikazuje, ima prirubnicu 15, koja je smeštena izmedu delova la, lb, i odreduje debljinu zazora za izolacioni sloj 16. Na strani dela la je predvidena zaštitna ploča 17, koja, opet uz umetanje fžolacionog sloja 18, naleze na deo la. Dužina »a« izolacione čaure 14 je za debljinu izolacionog sloja 18 veča od debljine »b« dela la na mestu 6 preklapanja. Otvori 19 u zaštitnoj ploči 17 odgovaraju prečniku spojnih zavrtanja 10, a istureni deo (a—b) izolacione čaure 14 odreduje prema torne širinu zazora za izolacioni sloj 18.In FIG. 5 and 6 show an enlarged view of the insulation point 5. The part of the two-part lever 1 is bent at the point 6 of the fold to form a backrest 7, while the other part of the lb is straight and has only - 37 289 - a discharge 8 with a backrest 9. Both parts 1a, 1b are secured to each other by screws 10 with nuts 11, with one solid pulley 11a inserted below the screw head and under nut 11. The openings 12 in part lb have a diameter corresponding to the diameter of the connecting screws 10. The openings 13 in part la have a larger diameter, so that an insulating sleeve 14 of artificial resin is inserted between the turns fO and the openings 13, which, as in FIG. 7 shows a flange 15, which is located between the parts la, lb, and determines the thickness of the gap for the insulating layer 16. On the side of part la is provided a protective plate 17, which, again with the insertion of the foliation layer 18, contacts the part la. The length "a" of the insulation sleeve 14 is greater than the thickness "b" of the part la at the overlap location 6 for the thickness of the insulating layer 18. The openings 19 in the protection plate 17 correspond to the diameter of the connecting screws 10, and the projecting portion (a-b) of the insulating sleeve 14 determines according to friction the width of the gap for the insulating layer 18.

Delovi la, lb se na mestu izolacionih slojeva 16 i 18 premazuju otvrdavajučom veštačkom smolom, koja se nanosi lopaticom. Posle toga se izolaciono mesto 5 pritegne pomoču spojnih zavrtanja 10 i posle otvrdnjavanja veštačke smole se spojni zavrtnji 10 potpuno pritegnu.Parts 1a, 1b are coated in place of insulating layers 16 and 18 with a trowel-hardened artificial resin. Thereafter, the insulation point 5 is tightened by means of connecting screws 10 and, after hardening of the artificial resin, the connecting screws 10 are tightened completely.

Oblik izvodenja dvodelne poluge 1 sa srednjim zahvatom (sl. 8 i 9) razlikuje se od primera izvodenja prema sl. 5 i 6 samo time, što je predviden treči deo 20 dvodelne poluge 1. Na analogan način je deo la spojen sa delom 20 i ovaj deo 20 opet sa delom lb.The embodiment of the mid-engined two-piece lever 1 (Figs. 8 and 9) differs from the embodiment of Figs. 5 and 6 only, provided that the third part 20 of the two-piece lever is provided 1. In an analogous manner, the part la is connected to part 20 and this part 20 again to part lb.

Claims

PATENT APPLICATION

A two-piece, electrically insulated, rail link lever consisting of at least two parts la, lb, which connect to one another and connect to each other via screw 10, whereby these parts la, lb do not overlap each other and at least one portion la of the lever 1 is bent at the point 6 of overlap and has a support 7, on which the front side of the second part lb of the lever 1 rests, characterized in that both parts (la, lb) of the lever (1) are connected via an inserted electrical insulation layer (16), wherein the connected screws (10) are enclosed by electrically insulating sleeves (14) with flanges (15) and the lever part (1) ^{at the} point (6) of overlap with the connecting screws (10) is insulated over insulating bushing (14) and covered externally by a metal protective plate (17) with an insulation layer (18) inserted and openings (19).