SE123720C1

SE123720C1 -

Info

Publication number: SE123720C1
Authority: SE
Publication date: 1948-01-01

Description

Uppfinnare: L. P. M. v. Overbeek. Inventor: L. P. M. v. Overbeek.

Prioritet be,gard frtin den 15 mars 1945 (Belgien). Priority will be given to March 15, 1945 (Belgium).

Foreliggande uppfinning hanfor sig till en anordning for skyddande av den manskliga kroppen mot farlig elektrisk spanning. The present invention relates to a device for protecting the human body from dangerous electrical voltage.

Det finnes fall, da spanningen kan tillforas en apparat utan nagon risk, under forutsattning att 'ikon del av ifragavarande apparat, t. ex. metallholjet eller ett under apparatens handhayande anyant elektriskt ledande foremal, exempelvis ett arbetsstycke eller en arbetsbank ay metall, är palitligt jordforbundet. Jordforbindningen kan emellertid genom glounska icke ha blivit verkstalld eller kan namnda fOrbindning aybrytas genom averkan eller pa annat satt. There are cases where the voltage can be applied to a device without any risk, provided that the icon is part of the device in question, e.g. the metal casing or any electrically conductive object under the handling of the apparatus, for example a workpiece or a workbench ay metal, is reliably grounded. However, the earth connection may not have been effected by glounska or the said connection may be interrupted by felling or in any other way.

Genom det brittiska patentet nr 487 935 fir en anordning ay oyannamnt slag tidigare kand, vid vilken den for manniskokroppen farliga spanningen automatiskt icke patryckes, forran tilliOrlitlig jordforbindning forefinnes, varvid spiinningen tillf5res under formedlinn ay ett rela och den omtalade jordforbindningen ingar i relaets magnetiseringskrets. En nackdel yid derma skycldsanordning Or den, all i handelse av ett fel pa relaspolen t. ex. en kortslutning ay spolen direkt med jord — relakontakterna aro slutria, trots alt apparaten, som skall skyddas, Or otillrackligt jordad. Derma naekdel undvikes genom anordningen enligt foreliggande uppfinning. U.S. Pat. A disadvantage yid this shielding device Or den, all in the act of a fault on the relay coil e.g. a short circuit ay the coil directly with earth - the relay contacts aro slutria, despite all the device to be protected, Or insufficiently grounded. This component is avoided by the device according to the present invention.

Enligt uppfinningen Or relitet yid en anordning _ay nyssnamnt slag kopplat i serie med -ett andra rela, yars magnetiseringsspole kopplad parallellt med dess kontakter. According to the invention, the relay yid of a device _ay just named type is connected in series with -a second relay, yars excitation coil connected in parallel with its contacts.

Ett fOrbattrat skydd tillforsakras harige- nom, en5r det andra relacts kontakter icke slutas till foljd ay att det forsta relaet inkopplas pa grund ay namnd:a kortslutning, varfor den hoga impedansen ay ,det andra reldets spole alltid ligger mellan apparaten (och manniskokroppen) .och matarspanningen. Improved protection is ensured by this, because the contacts of the second rela are not closed as a result of the first rela being switched on due to a short circuit, so the high impedance ay, the coil of the second rela always lies between the device (and the human body). and the supply voltage.

Anordningen enligt uppfinningen kan anYandas sasom ersattning for en transformator, som stundom anvandes i andamal att nedsfitta den tillforda spanningen till ett sakert eller mindre farligt varde, yilket innebar, att den tillforda spanningen 1 och for sig skulle ha varit anyancibar, sayida den icke utgjorde en kalla for utomordentlig fara. Ett sadant fall forekommer sarskilt vid -elektrisk syetsning. The device according to the invention can be used as a replacement for a transformer, which was sometimes used in other cases to reduce the supplied voltage to a safe or less dangerous value, which meant that the supplied voltage 1 and in itself would have been unanimous, say it did not constitute a call for extraordinary danger. Such a case occurs especially in electrical sewing.

Ett icke eller Mott otillforlitligt jordat arbetsstycke utgor en farokalla for syetsarert, nar en kand anordning ay ovan beskrivet slag anvandes. Anvanclningen ay anordningen enligt uppfinningen elhninerar _denna fara och medfor dessutom till skillnad fran vad fallet Or yid anvandning ay en transformator, en enklare och hilligare anordning med mindre storlek och vikt. A non- or Mott unreliably grounded workpiece constitutes a danger call for sewing equipment when a known device of the type described above is used. The use of the device according to the invention eliminates this danger and, moreover, in contrast to the case of the use of a transformer, entails a simpler and holier device of smaller size and weight.

Uppfinningen konamer att forklaras narmare i del foljande under hanvisning till Mfogade ritning, SSIII schernatiskt visar en utfdringsform sasom exernpel pit uppfinningen. The invention will be explained in more detail in the following part with reference to the accompanying drawing, SSIII schernatically shows an embodiment as exemplified by the invention.

Enligt ritningsfiguren utgOres belastningen enbart ax en bagsvetsanordning, varvid en transformator kan undvaras, sasom namnts i det foregaende. According to the drawing figure, the load consists only of a back-welding device, whereby a transformer can be dispensed with, as mentioned above.

Bagsvetsanorclnirtgen bestar av en kolelektrod 1 och en tang 2, med vilken arbetsstycket 3 fasthdlles. Tangen 2 Or forbunden med jord. Elektrodens anslutningsledare 6 Or Over ett motstand 15, kontakterna 13 pa ett rela 11, kontakterna 4 p0 ett rela MI en stri3mstallare forbunden med en spanningsklamma pa. energitillforselanordningen. Energitillfor_selanordningens andra klamma 7 Or forbunden flied jord. The back-welding anorcnirtgen consists of a carbon electrode 1 and a pliers 2, with which the workpiece 3 is held. Pliers 2 Or connected to ground. Electrode connection conductor 6 Or Over a resistor 15, contacts 13 on a relay 11, contacts 4 on a relay MI a current generator connected to a voltage terminal on. the energy supply device. The second clamp of the energy supply device 7 Or connected flied ground.

Magnetiseringsspolen 8 for relaet 5 Or forbunclen med en punkt p5. tangen 2, sa att spolens magnetiseringskrets Or sluten Iran den icke jordade energitillforselklamman Over spolen 8, tangen 2, jordforbindningen och den andra en-ergitillforselklamman 7. The excitation coil 8 for the relay 5 Or the bundle with a point p5. pliers 2, said that the coil excitation circuit Or closed Iran the ungrounded power supply terminal Over the coil 8, pliers 2, the ground connection and the other energy supply clamp 7.

Nar strOmstallaren Or tillslagen, Or relaet 5 fOljaktligen magnetiserat och Oro salunda kontakterna 4 slutna endast da namnda krets och sarskilt tangens 2 jordforbindning Or obruten, vilket har till fOljd, att den apparaten handha-vande personen icke utsatter sig for fara genom att berora elektroden 1. When the switch is switched on, the relay 5 is consequently magnetized and the contacts 4 are closed only when the said circuit and in particular the tangent 2 of the tangent 2 are disconnected, which has the consequence that the person operating the device does not expose himself to danger by touching the electrode 1. .

Ett fel ph relaet 5, t. ex. en kortslutning ay spolen 8 med jord vid en punkt framfor tang- — — en 2, och otillraeklig jordning av derma kan dock alltjamt medfora, att relaets kontakter sl-Jtas. An error ph relaet 5, e.g. a short circuit on the coil 8 with earth at a point in front of the pliers 2, - and insufficient grounding thereof can, however, still cause the contacts of the relay to sl-Jtas.

Enligt uppfinningen ar nu relaet 5 kopplat i serie med det andra relaet 11, som bestar av ett ankare 12 och kontakterna 13 och vars magnetiseringsspole 14 är kopplad parallellt med kontakterna 13. Till forman for svetsauordningen är dessutotn, som miimnts, i svetskretsen inkopplat eti litet motstand 15 pa omkring 5 ohm. According to the invention, the relay 5 is now connected in series with the second relay 11, which consists of an armature 12 and the contacts 13 and whose excitation coil 14 is connected in parallel with the contacts 13. In addition, as mentioned, the welding circuit is connected in the welding circuit. resistor 15 pa about 5 ohms.

Om reldet 5, siisom namuts ovan, likval skulle sluta av flagon ieke onskad anledning, skulle relaet 11, i handelse att tangen 2 ieke eller Mott ofullstandigt är jordad, ieke forbinda koleleklroden 1 med tillforselnatet direkt Over kontakterna 13 och ankaret 12, nar svetsning pagar, utan endast over det stora tnotstandet hos magnetiseringsspolen 14, varigenom tillrackligt skydd inot ovalkommen stromgenomgang genom mannsikokroppen tillforsakras. If the line 5, as mentioned above, should nevertheless end for the sake of undesired reason, the relay 11, in the event that the pliers 2 ieke or Mott are incompletely grounded, would not connect the carbon ball 1 with the supply line directly over the contacts 13 and the armature 12, when welding stops. , but only above the large pitch of the excitation coil 14, thereby ensuring sufficient protection against oval current passage through the human microbial body.

I handelse att tangens jordforbindning ãr fullgod sinter rethet 11 pa grund av den hOga magnetiseringsstromstyrkan och medgiver salunda svetsning pa normalt salt. In the case that the ground connection of the pliers is sufficiently sintered straightness 11 due to the high excitation current and thus allows welding on normal salt.

Nar svetsningen ar utford, Oppnas reliiet 11 Ater. When welding is a challenge, the religion 11 Ater is opened.

Claims

Patent claim: Device for protecting the human body against dangerous electrical voltage, in that said voltage is not automatically depressed by the apparatus to be operated before a reliable earth connection has been made, for example during welding, in which device the voltage is supplied with hi alp of a relay, the earth connection in question forming in the magnetizing circuit of the relay, characterized in that the relay is connected in series with a second relay, the excitation coil of which is connected in parallel with its contacts. Stockholm 1948. Kmigl. Boktr. P. A. Norstcdt & Kner 480089