SE191742C1 - - Google Patents

Info

Publication number
SE191742C1
SE191742C1 SE191742DA SE191742C1 SE 191742 C1 SE191742 C1 SE 191742C1 SE 191742D A SE191742D A SE 191742DA SE 191742 C1 SE191742 C1 SE 191742C1
Authority
SE
Sweden
Prior art keywords
shaft
stop
synchronous
arm
contact
Prior art date
Application number
Other languages
Swedish (sv)
Publication date
Publication of SE191742C1 publication Critical patent/SE191742C1/sv

Links

Landscapes

  • Selective Calling Equipment (AREA)

Description

Uppfinnare: H Hiirlimann Prioritet begeird !ran den 23 juni 1956 (Schweiz) Gentralfj arrstyrningsanlaggningartj dna som bekant till att sanda kopplingsorder Iran en ordercentral over det elektriska kraftnatet till alla forbrukningsplatserna, t. ex. for taxeomstallning av rakneverk; in- eller urkoppling av forbrnkningsapparater, exempelvis kokapparater, ugnar, gatubelysning in. m., eller for styrning av omkopplare. Inventor: H Hiirlimann Priority requested on 23 June 1956 (Switzerland) Gentralfjärstyrningsanlagningtjnna as known to send connection orders Iran an order center over the electric power grid to all consumption points, e.g. for taxi conversion of rakes; switching on or disconnecting combustion appliances, for example cooking appliances, ovens, street lighting. m., or for control of switches.

Pa kant satt utsandas darvid tonfrekventa impulser pa natet Fran en sandare vid ordercentralen, och de platser, som skola styras, aro utrustade med mottagare, vilka paverkas ay bestamda ordersignaler och utfora den avsedda kopplingsfunktionen. De vanligaste ay de olika fora k5nda centralfjarrstyrnings- systemen arbeta efter tidsintervallforfarandet. Vid detta tillordnas en serie efter varandra foljande orderimpulser till en startimpuls. On the edge, tone-frequency impulses are transmitted on the network from a transmitter at the order center, and the locations to be controlled are equipped with receivers, which are affected by specific order signals and perform the intended switching function. The most common of the various pre-known central remote control systems operate according to the time interval procedure. In this case, a series of successive order pulses are assigned to a starting pulse.

Dessa alstras vanligen medelst en ay en synkronnaotor driven givare, vilken pa kant satt Over en tonfrekvenssandaranlaggning arbetar pa det styrda kraftnatet. Mottagarna utgoras vanligen ay synkront med natfrekvensen 10- pande valj are, vilkas kontakter aro anordnade I overensstdmmelse med kontakterna hos synkrongivaren. These are usually generated by means of a sensor driven by a synchronous motor, which is mounted on an edge above a tone frequency transmitter system operating on the controlled power grid. The receivers are usually synchronous with the night frequency of 10-point selectors, the contacts of which are arranged in accordance with the contacts of the synchronous sensor.

Mottagaranordningar av det beskrivna slaget innehalla ofta kansliga mottagningsrelaer, som kunna komma att paverkas am i natet forekommande storspanningar. Mot besta.ende stOrspanningar, skyddar man sig genom att valja ;en styrspanning, som ligger Over den mojliga stornivan. Till skydd mot kortvariga, men jamforelsevis intensiva, storimpulser ha olika atgarder foreslagits och en del ha kommit till anvandning. Dot har exempelvis foreslagits att anordna en fordrojningsanordning for overforingen am orderimpulserna, vilken fungerar pa Sa sätt, att storimpulser, som, aro kortare an orderimpulserna, inte paverka mot- Dupl. kl. 21 c: 45/05; 21 c: 45/06 tagningsanordningen, eller att forse synkronvaljaren, for att forhindra igangsattning genom kortvariga storimpulser, med en aterstallningsanordning, sora alltid aterstaller valjaren till nollaget nar impulsema inte ha en bestaand varaktighet. Det ar dâ lampligt att valja startimpulsen langre an orderimpulserna och den maximala tid, efter vilken Aterstallning sker, langre an orderimpulserna. Man uppnar harigenom, att valjaren varken startas av kortvariga stOrimpulser eller av orderimpulser. Receiver devices of the type described often contain sensory reception relays, which may be affected by high voltages occurring in the network. Against existing large voltages, you protect yourself by choosing a control voltage, which is above the possible large level. For protection against short-term, but comparatively intense, large impulses, various measures have been proposed and some have been used. It has, for example, been proposed to arrange a delay device for the transmission of the order pulses, which works in such a way that large pulses, which are shorter than the order pulses, do not affect the counter-Dupl. at 21 c: 45/05; 21 c: 45/06 the recording device, or to supply the synchronous selector, in order to prevent initiation by short-term large pulses, with a resetting device, so that the selector always returns to the zero layer when the pulses do not have a lasting duration. It is then appropriate to select the start pulse longer than the order pulses and the maximum time after which Reset takes place longer than the order pulses. This means that the selector is not started by short-term power impulses or by order impulses.

Uppfinningen avser en konkret utforingsform av den ovannamnda aterstallningsanordningen. Den avser nal-mare bestamt en fjarrstyrningsmottagare enligt synkronvaljarprincipen for med tonfrekvensoverlagring pa kraftnat arbetande centralfjarrstyrningsanlaggningar, s. k. rundstyrningsanlaggningar, mid vilken en medelst en synkronmotor driven axel paverkar dels en i stromkretsen for synkronmotorn liggande kontaktanordning, vilken efter motorns startning medelst en startimpuls hailer motorn ansluten till natet under 'axelns vridning ett vary, och dels minst en orderimpulserna tillordnad kontaktanordning, varvid synkronvaljaren aterfores till nollaget medelst en aterstallningsanordning, nar den forts ur sitt nollage av impulser, v11- ka aro kortare an en normal startirnpuls. Mottagaren kannetecknas av att aterstallningsanordningen innehaller ett pa en i beroende ay synkronaxelns rorelse driven hjalpaxel fastsatt, med ett spar forsett aterstallningsorgan, vidare en pa hjalpaxeIn svan.gbart lag-grad, medelst en aterstallningsfjdder mot ett fast anslag tryckt aterstallningshavarm oda slutligen ett pa denna havarm svangbart lag-rat kopplingsorgan, -Vilket är fOrsett med en i. spAret ingripande arm och har ett finger. 2— -- som anligger mot ett stoppanslag pa en svangbar, med en. pasynkronaxeln fastsatt kam- skiva sarnverkande stopphavarm saint en. mot fjadern 1 en rorlig kontakt i en kontaktanordning tryckt, med kopplingsorganet fast Mrbunden tapp, vilken vid medbringning av kopplingsorganet medelst aterstallningsorganet hailer en kontakt i synkronmotorns start- stromkrets sluten, tills efter en bestamd vridning av hjalpaxeln, som endast en normal startimpuls men icke en storimpuls kan astadkomma, fingret pa kopplingsorganet genom inverkan av kontaktfjadern glider under stoppanslaget, varvid amen pa kopplingsorganet lyftes ur sparet och kontakten i synkronmotorns hallstromkrets slutes. The invention relates to a concrete embodiment of the above-mentioned restoration device. More specifically, it relates to a remote control receiver according to the synchronous selector principle for tone frequency overlay on high-power central remote control systems, so-called rotary control systems, by means of which a shaft driven by a synchronous motor affects a contactor in the circuit during the rotation of the shaft a vary, and at least one contact device assigned to the order pulses, the synchronous selector being returned to the zero layer by means of a reset device, when it continues from its zero position of pulses, which are shorter than a normal starting pulse. The receiver can be characterized in that the restoration device comprises a auxiliary shaft driven on an auxiliary shaft driven on a dependent axis of movement of the synchronous shaft, furthermore a recovery degree which can be rotated on an auxiliary axis, by means of a restraint spring against a fixed abutment. pivotally mounted coupling member, -Which is provided with an interlocking arm and has a finger. 2— - which rests against a stop on a swing bar, with a. The camshaft is mounted on the camshaft shaft. against the spring 1 a movable contact is pressed in a contact device, with the coupling means fixedly bound pin, which when bringing the coupling means by means of the resetting means hails a contact in the synchronous motor starting circuit closed, until after a certain rotation of the auxiliary shaft but only a normal starting pulse large impulse can be produced, the finger on the coupling means by the action of the contact spring slides under the stop stop, whereby the amen on the coupling means is lifted out of the recess and the contact in the hall circuit of the synchronous motor is closed.

Uppfinningen skall narmare beskrivas nedan med hanvisning till de bifogade ritningarna, varvid fig. 1 och 2 visa en. utforingsform av aterstallningsanordningen fore resp. efter ankomsten av en startimpuls. The invention will be described in more detail below with reference to the accompanying drawings, in which Figs. 1 and 2 show one. embodiment of the restoration device before resp. after the arrival of a starting impulse.

I fig. 1 är synkronmotorn M ansluten till natet U over kontakten r pa ett mottagningsrela E ,och kontaktparet K2, K3 i ett kontaktpaket Kl, K2, K3. Synkroninotorn M star medelst kugghjulen. Z1, Z2 i forbindelse med en hjalpaxel HW och denna star i sin tur i fOrbindelse med synkronaxeln W medelst kugghjulen Z3, Z4. Synkronaxeln W och hjalpaxeln 11W aro med fordel anordnade parallella med varandra. pa hjalpaxeln 11W är en cirkelformig skiva R fastsatt, vilken vid omkretsen är forsedd med ett spar N, och en havarm RH är svangbart lagrad pa hjalpaxeln. Havarmen RH tryckes niedelst en vid en fast del V fastsatt fjader RF mot ett likasa fast anslag P. Havarmen RH uppbar en tapp Z, pa vilken en havarm K är svangbart lag-rd. Havarmen K är forsedd med en arm S, vilken ingriper i sparet N pa skivan R, och ett med havarmen K fast forbundet stift B paverkar mittkontakten K2 i kontaktpaketet Kl, K2, K3. Havarmen K uppvisar vidare ett finger F med en yta 0, vilken I det visade la.- get for havarmen K atminstone i det narmaste bildar en del av en med axeln 111V koncentrisk valsyta. Havarmen K tryckes rued ytan 0 mot anslaget H genom verkan av en fjader, foretradesvis fjadern i mittkontakten K2. In Fig. 1, the synchronous motor M is connected to the network U via the contact r on a receiving relay E, and the contact pair K2, K3 in a contact package K1, K2, K3. The synchronous motor M stands by means of the gears. Z1, Z2 in connection with an auxiliary shaft HW and this in turn is connected to the synchronous shaft W by means of the gears Z3, Z4. The synchronous axis W and the auxiliary axis 11W are advantageously arranged parallel to each other. on the auxiliary shaft 11W a circular disc R is attached, which at the circumference is provided with a groove N, and a sea arm RH is pivotally mounted on the auxiliary shaft. The sea arm RH is pressed below a spring RF attached to a fixed part V against a similar fixed stop P. The sea arm RH carried a pin Z, on which a sea arm K is pivotally mounted. The sea arm K is provided with an arm S, which engages in the recess N on the disc R, and a pin B fixedly connected to the sea arm K acts on the center contact K2 in the contact package K1, K2, K3. The sea arm K further has a finger F with a surface 0, which in the shown position of the sea arm K forms at least almost a part of a rolling surface concentric with the shaft 111V. The sea arm K is pressed rued surface 0 against the stop H by the action of a spring, preferably the spring in the central contact K2.

Anslaget H är utbildat sasom en del av en tvaarmad havstang All, vilken är s-vangbar omkring en fast tapp T, och med hjalp av fjadern AF star i kontakt med banan G, Fl pa en, kamskiva A, vilken är fastsatt pa. axeln. W. Tappens T lage ãr ddrvid sa valt, att vid svangning av havarmen All anslaget H ror sig pa en. bana, vars forlangning gar genom axeln HW. Om mottagningsrelaet E i fig. 1 magnetiseras, sluter dess kontakt r stramkretsen f& synkronanotorn M och denim bar-jar rotera i en bestamd riktning. Darvid vrider den over kugghjulen Z1, Z2, Z3, Z4 orlarna HW och W i de visade pilarnas rikt ning. Med hjalpaxeln 11W vrides skivan. R, vilken med sitt spar N medbringar armen S pa havarmen K och darned havarmarna K och RH. Havannen RH avlagsnas genom den- na rorelse fran anslaget P och fjadern RF spannes. Darvid riir sig ytan 0 pa fingret F langs anslaget H. Laget for kontaktpaketet Kl, K2, K3 Ai- darvid sa valt, att stiftet B mot trycket Fran kontaktens K2 fjader hailer de bagge kontakterna K2, K3 slutna. The stop H is formed as a part of a two-armed sea rod All, which is pivotable about a fixed pin T, and with the aid of the spring AF is in contact with the path G, Fl on one, cam disc A, which is fixed on. axeln. W. Tappens T lage is then chosen so that when swinging the sea arm All the stop H moves on one. path, the demand of which passes through the axis HW. If the reception relay E in Fig. 1 is magnetized, its contact closes the circuit f the synchronous notor M and denim bars rotate in a certain direction. In doing so, it rotates the gears HW and W in the direction of the arrows shown over the gears Z1, Z2, Z3, Z4. With the auxiliary shaft 11W, turn the dial. R, which with its spar N carries the arm S on the sea arm K and then the sea arms K and RH. Havanen RH is removed by this movement from the stop P and the spring RF is tensioned. In this case, the surface 0 on the finger F moves along the stop H. The layer for the contact package K1, K2, K3 has been chosen so that the pin B against the pressure from the spring K2 of the contact K holds the rear contacts K2, K3 closed.

Om ytan 0 pa havarmen K vid den fortsatta vridningen av axeln. HW lamnar anslaget H, svanges havarmen K german inverkan frau fjadern i kontakten K2, sa att armen S pa havarmen K fares ur sparet N, varigenom skivans R forbindelse med havarmen RH och K avbrytes (fig. 2). Darvid kommer fingret F under anslaget H och forhindrar en tillbakasvangning av havarmen RH genom fjaclerns RF verkan. Samtidigt bringas genom denna svangning av havarmen K med stiftet B de bagge kontakterna K2, K3 ur beroring med varandra, och stromkretsen Over kontakterna Kl, K2 slutes. Darigenom .anslutes synkronmotom M direkt till natet U och ror sig i fortsattningen oberoende av mottagningsrelaet E, vilket harefter overfor orderimpulserna. Darvicl svanges pA grund av formen hos banan G pa kamskivan A havarmen All langsamt sa, att anslaget H pa ritningen ror sig at hoger, varvid det friger fingret F, och havarmen RH genom verkan av fjadern RF fores tillbaka till anslaget P. Efter ytterligare vridning av synkronaxeln W glider havarmen AH vid uppnAendet av ett helt varvs vridning Over kanten Fl pa kamskivan A, varvid anslaget H ror sig At vanster pa ritningen och trycker in havarmen K i det i fig. 1 visade laget och Ater skjuter in. dennas arm S i sparet N pa skivan R. Darigenom brytes stroankretsen Over kontakterna Kl, K2 me-deist stiftet B, och kontakterna K2, K3 bringas Ater i beroring med varandra. Eftersom re-lad E efter avslutad impulssandning icke mer magnetiseras, är dess kontakt oppen. Motorn M stannar och hela anordningen Ar fardig for ett nytt forlopp. If the surface 0 of the sea arm K at the continued rotation of the shaft. HW leaves the stop H, the lever arm K is actuated by the action of the spring in the contact K2, so that the arm S on the lever arm K is removed from the recess N, whereby the connection of the disc R to the lever arm RH and K is interrupted (Fig. 2). Thereby, the finger F comes under the stop H and prevents a recoil of the sea arm RH by the RF action of the feathers. At the same time, by this oscillation of the sea arm K with the pin B, the ram contacts K2, K3 are brought out of contact with each other, and the circuit Over the contacts K1, K2 is closed. Thereby, the synchronous motor M is connected directly to the gate U and moves in the continuation independently of the reception relay E, which then faces the order pulses. Darvicl is pivoted due to the shape of the web G on the cam disc A the lever All slowly so that the stop H in the drawing moves to the right, whereby it releases the finger F, and the lever RH by the action of the spring RF is moved back to the stop P. After further rotation of the synchronous shaft W, the sea arm AH slides at the achievement of a complete revolution of rotation Above the edge F1 on the cam disc A, the stop H moving to the left of the drawing and pushing the sea arm K into the layer shown in Fig. 1 and Ater pushes in. its arm S in the recess N on the disc R. Thereby the circuit is broken across the contacts K1, K2 with the pin B, and the contacts K2, K3 are brought back into contact with each other. Since the relay E is no longer magnetized after the end of impulse sanding, its contact is open. The motor M stops and the whole device is ready for a new process.

Denna beskrivna funktion sker, am startimpulsen ham tillra.cklig langd. Vid korta stromstotar, t. ex. storningar, lanmar ytan 0 pa havarmen K icke anslaget H °eh fjadem RF vrider med hjalp av delama RH, K, R, Z2, Z1 motor. M efter stromstotens slut Ater till utgangslaget. This described function takes place if the starting impulse is of sufficient length. In the case of short current surges, e.g. faults, the surface 0 on the sea arm K does not stop H ° eh fjadem RF turns with the help of the parts RH, K, R, Z2, Z1 engine. M after the end of the current surge Ater to the starting point.

Anordningen enligt uppfinningen har inte endast den fordelen, att mottagarens igangsattning pa grund av kortvariga storimpulser eller pa grund av orderimpulser, som aro kortare An startimpulsen, Mrsvaras. Den tillater dessutom genom sthrre precision Mr synkronvaljarens nollage storre precisering av impulsdiagrammens lagen fOr de, ofta i stort antal, i naten inkopplade mottagarna. Eftersom bestamda toleransfordringar mAste fore- — —3 skrivas f6r impulsdiagrammens noggrannhet med hansyn till mottagarnas synkrona stall-fling i forhallande till det sanda impulsdiagrammet for att ett stort antal mottagare skola kunna fungera ph ett riktigt salt, medfor anordningen enligt uppfinningen dessutom betydande lattnader fOr serietillyerkningen av mottagningsapparater. Den beskrivna utforingsform av uppfinningen har den fOrdelen, att den latt kan sammansattas till ett sjalvstandigt konstruktionselement, som utan namnyarda ytterligare konstruktionsatOrder kan infogas i mottagare, sam inte aro utrustade med en aterstallningsanordning. The device according to the invention not only has the advantage that the initiation of the receiver due to short-term large impulses or due to order impulses which are shorter than the starting impulse is answered. In addition, through greater precision, the synchronous selector's zero allows greater clarification of the law of impulse diagrams for the receivers, often in large numbers, connected at night. Since certain tolerance requirements must be prescribed for the accuracy of the pulse diagrams with respect to the recipients' synchronous stall-fling in relation to the true pulse diagram in order for a large number of receivers to be able to function with a real salt, the device according to the invention also provides significant relief for series. of receiving devices. The described embodiment of the invention has the advantage that it can be easily assembled into an independent construction element, which can be inserted into recipients without naming or additional construction elements, which are not equipped with a restoration device.

Claims (3)

Patentansprak:Patent claim: 1. Fjarrstyrningsmottagare enligt synkronvaljarprincipen for med tonfrekyensoverlagring pa kraftnat arbetande centralfjarrstyrningsanlaggningar, s. k. rundstyrningsanlaggningar, yid vilken en medelst en synkronmotor driven axel paverkar dels en i steamkretsen for synkronmotorn liggande kontaktanordning, vilken after motorns startning me-deist en, startimpuls hailer motorn ansluten till natet under axelns vridning ett vary, och dels minst en orderimpulserna tillordnad kontaktanordning, yarvid synkronvaljaren aterfares till nollaget medelst en aterstallningsanordning, nal- den forts ur sitt foliage av impulser, vilka aro kortare an en. normal startimpuls, kannetecknad darav, att aterstallningsanordningen innehaller ett pa en i heroende av synkronaxelns (W) rorelse driven hjalpaxel (11W) lastsatt, med ett sphr (N) forsett aterstallningsorgan (R), yidare en pa hjalpaxeln (HW) syangbart lagrad, me-deist en aterstallningsfjader (RP) mot ett fast anslag (P) tryckt aterstallningshavarm (RH) och slutligen ett pa denna havarm svangbart lagrat kopplingsorgan (K), vilket Or fOrsett med en i sparet (N) ingripande arm (S) och har ett finger (F) som anligger mot ett stoppanslag (H) pa en svangbar, med en pa synkronaxeln (W) fastsatt kamskiva (A) sarnverkande stopphayarm (A11) saint en mot fjadern i en rorlig kontakt (K2) i en kontaktanordning (K1—K2--K3) tryckt, med kopplingsorganet (K) fast forbunden tapp (B), vilken vid meclbringning av kopplingsorganet (K) medelst aterstallningsorganet (R) hailer en kontakt (K2—K3) i synkron.motorns (M) startstramkrets sluten tills efter en bestamd vridning ay hjalpaxeln (11W), som endast en normal startimpuls men ieke en storimpuls kan astadkomma, fingret (F) pa kopplingsorganet (K) genom inverkan av kontaktfjadem (K2) glider under stoppanslaget (H), varvid armen (S) pa kopplingsorganet (K) lyftes in. sparet (N) coal kontakten (K1—K2) i synkronmotorns (M) hallstromkrets slutes.1. Remote control receiver according to the synchronous selector principle for tone frequency overlay on high-power central remote control systems, so-called rotary control systems, in which a shaft driven by a synchronous motor affects a contact device in the steam circuit for the synchronous motor, which after the motor starts the rotation of the shaft is varied, and at least one contact device assigned to the order pulses, in which case the synchronous selector is returned to the zero layer by means of a resetting device, the needle continues from its foliage of pulses which are shorter than one. normal starting impulse, characterized in that the recovery device contains a recovery shaft (11W) loaded on an auxiliary shaft (11W) driven in dependence on the movement of the synchronous shaft (W), with a spur (N) provided recovery means (R), further mounted on the auxiliary shaft (HW), with -deist a recovery spring (RP) against a fixed stop (P) pressed recovery arm (RH) and finally a coupling member (K) pivotally mounted on this arm arm, which Or is provided with an arm (S) engaging in the groove (N) and has a finger (F) which abuts against a stop stop (H) on a pivotable, with a cam disc (A) attached to the synchronous shaft (W) acting as a stop shear arm (A11) saint one against the spring in a movable contact (K2) in a contact device (K1— K2 - K3) pressed, with the coupling means (K) fixedly connected pin (B), which when the coupling means (K) is coupled by means of the resetting means (R) has a contact (K2 — K3) in the synchronous motor (M) starting circuit closed until after a certain rotation ay the auxiliary axis (11W), which only a n normal starting impulse but not a large impulse can be achieved, the finger (F) on the coupling member (K) by the action of contact spring (K2) slides under the stop stop (H), whereby the arm (S) of the coupling member (K) is lifted in. the spare (N) coal contact (K1 — K2) in the synchronous motor (M) hall circuit is closed. 2. Mottagare enligt patentanspra.ket 1, kannetecknad &ray, att den. ay stoppanslaget (H) under stopphavarmens (A11) svangningsrorelse beskrivna banans forlangning atminstone i del narmaste gar genom hjalpaxeln (11W).Recipient according to patent claim 1, can be signed & ray, that it. ay the stop (H) during the oscillation movement of the stop lever (A11) described path at least in the nearest part passes through the auxiliary axis (11W). 3. Mottagare enligt patentanspraken 1 och 2, kannetecknad daray, att hjalpaxeln (11W) ligger parallellt med synkronaxeln (W) och Or forhunden med denna medelst en kugghjulsvaxel (Z3, Z4). AnfOrda publikationer:Receiver according to claims 1 and 2, characterized in that the auxiliary shaft (11W) lies parallel to the synchronous shaft (W) and is driven by it by means of a gear shaft (Z3, Z4). Request publications:
SE191742D SE191742C1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE191742T

Publications (1)

Publication Number Publication Date
SE191742C1 true SE191742C1 (en) 1964-01-01

Family

ID=41978152

Family Applications (1)

Application Number Title Priority Date Filing Date
SE191742D SE191742C1 (en)

Country Status (1)

Country Link
SE (1) SE191742C1 (en)

Similar Documents

Publication Publication Date Title
US2285414A (en) Control system and apparatus
NO124789B (en)
SE191742C1 (en)
GB589729A (en) Improvements in or relating to record-card controlled accounting machines
US1725044A (en) aldendorff
SE191743C1 (en)
US2286248A (en) Printing telegraph apparatus
US2267129A (en) Testing apparatus
US2651676A (en) Electric current impulse transmitter
US2217864A (en) Start-stop telegraph receiving apparatus
US2469761A (en) Cam controlled pulse transmitter
US1865592A (en) Batch meter
US1016499A (en) Electric-clock system.
US2129823A (en) Distortion indicating and measuring device
NO124788B (en)
US2301823A (en) Impulse mechanism
US1154250A (en) Operator's calling device.
US3033926A (en) Orientation device
US1168587A (en) Means for indicating faults and breaks in electric conductors.
US1537620A (en) System of electric contaol
US1911475A (en) Snap actuating mechanism
SE126774C1 (en)
GB642479A (en) An improved receiving device for electric switching operations in remote control installations
GB435624A (en) Improvements in and relating to electric indicating or indicating and recording systems
GB484318A (en) Improvements relating to phase determining mechanism for telegraph apparatus