SE202556C1

SE202556C1 -

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Publication number: SE202556C1
Authority: SE
Publication date: 1965-01-01

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KLASS INTERNATIONELLSVENSK GO1 g42 f:21 PATENT- OCH REGISTPERINGSVERKET Ans. 1346/1961 inkom den 9/2 1961 utlagd den 8/6 196 IMPERIAL CHEMICAL INDUSTRIES LTD, LONDON, STORBRITANNIEN Automatisk nettovag med pneumatisk reglering av tarering och matning Upplinnare: A K Lloyd och R A Lolley , Prioritet begard pan den 10 februari 1960 och 23 januart 1961 • (Storbritannien) Foreliggande uppfinning avser en anordning for automatisk styrning av tillforseln av massgods eller vatska till en vag. CLASS INTERNATIONAL SWEDISH GO1 g42 f: 21 PATENT AND REGISTRATION AGENCY Ans. 1346/1961 was received on 9/2 1961 issued on 8/6 196 IMPERIAL CHEMICAL INDUSTRIES LTD, LONDON, UNITED KINGDOM Automatic net scale with pneumatic control of tare and feed Trainer: AK Lloyd and RA Lolley, Priority requested on 10 February 1960 and 23 January 1961 • (Great Britain) The present invention relates to a device for automatically controlling the supply of bulk goods or liquids to a vag.

Mango, olika slags vagar aro kanda och ha fiireslagits, vid vilka tillforseln av det material, som skall uppvagas, automatiskt avbryts, nar en anskad mangd har uppvagts. Om materialet tillfors till en behallare, som uppbars av vagen, onskar man vanligen tarera behallaren, innan materialtillf8rseln igangsatts, och manga forslag ha gjorts avseende sattet far denna tarering. Mangoes, various kinds of scales are known and have been proposed, in which the supply of the material to be weighed is automatically interrupted when a certain amount has been weighed. If the material is supplied to a container, which is carried by the cart, it is usually desired to tare the container, before the material supply is started, and many suggestions have been made regarding the manner of this tare.

Det har foreslagits att man skall anvanda ett pneumatiskt system for att avbryta materialtillforseln till vagen, nar en onskad mangd har uppvagts. Enligt foreliggande uppfinning anvands ett pneumatiskt system for att automatiskt tarera behallaren och avbryta materialtillfarseln. It has been suggested that a pneumatic system be used to interrupt the supply of material to the carriage when a desired quantity has been weighed. According to the present invention, a pneumatic system is used to automatically tare the container and interrupt the material supply.

Enligt uppfinningen astadkommes salunda en vag av i patentansprakets ingress angivet slag och huvudsakligen uppvisande de i patentanspraket angivna kannetecknen. According to the invention, a vague is thus provided of the kind specified in the preamble of the patent claim and mainly having the pitcher marks specified in the patent claim.

Till uppfinningens belysning skall ett utf0- ringsexempel ddrav beskrivas i det faljande under hanvisning till de bifogade ritningarna. I dessa visar fig. 1 schematiskt den pneumatiska krets, medelst vilken uppvagningen styrs. Fig. 2a, b visar detaljerat styrkammaren och det darmed samverkande, till vagen horande elementet. FOr att forenkla fig. 1 visas de olika ventilerna uppdelade, sa att i Tart fall den mekanism, medelst vilken ventilen manovreras, visas skild fran sjalva ventilen. I fig. 1 visas var ventil i det lage, som svarar mot obelastad manavermekanism. To illustrate the invention, an exemplary embodiment will be described in the following with reference to the accompanying drawings. In these, Fig. 1 schematically shows the pneumatic circuit, by means of which the winding is controlled. Fig. 2a, b show in detail the control chamber and the cooperating element belonging to the carriage. To simplify Fig. 1, the various valves are shown divided, so that in Tart case the mechanism by which the valve is operated is shown separate from the valve itself. Fig. 1 shows each valve in the bearing corresponding to unloaded maneuvering mechanism.

Dupl. kl. 42 f: 34/08 I fig. 1 visas en i en vag ingaende vagbalk 1, vilken ar svangbart lagrad vid ett stod 2. Vagens utbalanseringsinrattning innefattar en fjader 3, vilken i sin ovre ande är ansluten till en havstang 4. Denna är svangbart lagrad i sin ena ande medelst en svangtapp 5 och vilar i sin andra ande mot en oljefylld balg 6. Vagbalken 1 uppbdr vid den sida am stadet 2, vid vilken fjadern 3 är ansluten, en vagSkal 7 far en standardvikt W. Nara vagskalen 7 .uppbar vagbalken en plattform 8 for en behallard, t. ex. ett fat, en: sack eller'dylikt, till vilken massgods eller vatska genom en hylsventil 9 kan tillforas frail en autornatisk matningsanordning. Hylsventilen 9 innefattar ett elastiskt eller kompressibelt riarstycke 10, vilket omges av ett stelt rarstycke it R8rstyckena 10 och 11 innesluta mellan sig en tryckkammare 12, till vilken tryckluft kan tillforas, sã att .genomstriimningsarean genom riirstycket 10 gradvis kan minskas anda ned till noll. Darigenom kan materialtillforseln genom hylsventilen gradvis minskas oh slutligen helt avbrytas. Dupl. at 42 f: 34/08 Fig. 1 shows a cradle beam 1 entering a carriage, which is pivotally mounted at a stand 2. The carriage balancing device comprises a spring 3, which in its upper spirit is connected to a sea rod 4. This is pivotable stored in one spirit by means of a pivot pin 5 and rests in its other spirit against an oil-filled bellows 6. The cradle beam 1 is mounted at the side of the station 2, to which the spring 3 is connected, a cradle shell 7 has a standard weight W. Near the cradle shell 7. the guard beam supported a platform 8 for a container, e.g. a dish, a sack or the like, to which bulk goods or liquid can be supplied through a sleeve valve 9 from an automatic feeding device. The sleeve valve 9 comprises an elastic or compressible pipe section 10, which is surrounded by a rigid pipe section in which the pipe sections 10 and 11 enclose between them a pressure chamber 12, to which compressed air can be supplied, so that the flow area through the pipe section 10 can be gradually reduced to zero. As a result, the material supply through the sleeve valve can be gradually reduced and finally completely interrupted.

Vid vagbalkens motsatta ande i forhallande till vagskalen 7 och plattformen 8 finns en tryckregulator 13. Denna visas detaljerat i fig. 2a och 2b, som visa en sidvy av tryckregulatorn resp. ett snitt langs linjen X—X. I fig. 2a visas en del av vagbalken 1, vilken yid sin aversida uppbar en upprattstaende, plan platremsa eller -tunga 14, Ett metallblock 15 med en vertikal skara eller spalt 16 är Bs-tad vid en- ldgesfast del av vagen pa sä salt, att den plana platremsan 14 kan rota sig, verti- kalt i spalten '16, nar vagbalken svanger. 2 tallblocket 15 är utbildat med tva horisontella hal 17 och 18, vilka aro belagna mitt for varandra pa onase sidor cm spalten 16. Dessa hal aro anslutna till en gemensam tryckluft- sasom antyds med pilforsedda linjer, och bilda munstycken, genom vilka luft utstrommar i spalten 16. At the opposite end of the cradle beam in relation to the cradle shell 7 and the platform 8 there is a pressure regulator 13. This is shown in detail in Figs. 2a and 2b, which show a side view of the pressure regulator resp. a section along the line X — X. Fig. 2a shows a part of the carriage beam 1, which on its upper side supported an upright, flat plate strip or tongue 14. A metal block 15 with a vertical groove or gap 16 is B-shaped at the end-fixed part of the carriage on such salt , that the flat plate strip 14 can take root, vertically in the gap '16, when the cradle beam swings. The pine block 15 is formed with two horizontal halls 17 and 18, which are located opposite each other on one side of the column 16. These halls are connected to a common compressed air which is indicated by arrow-provided lines, and form nozzles, through which air flows out in column 16.

Vagbalkens rorelsemojlighet begransas medelst ej visade stopp, sa att onOdiga svangningsriirelser forhindras. Stoppen aro sa belagna, att vagbalkens vanstra sida enligt fig. 1 kan svanga nedat sa mycket, att den plana platremsan 14 helt frilagger munstyckena 17 och 18. Vagbalkens vanstra sida kan vidare svanga uppat sâ mycket, att den plana platremsan 14 helt tacker munstyckena 17 och 18 och skjuter upp nagot ovanfor dessa. Balanslaget for en given uppvagningscykel Or anordnat att intraff a, nar det mottryck, som uppstar till fOljd av att den plana platremsan 14 delvis tacker munstyckena 17 och 18, har natt ett faststallt varde. Stoppen Oro lampligen sä anordnade, att vagbalkens rorelsemojlighet svarar mot uppvagningen av de sista 10-20 % av den nettovikt, som man onskar uppvaga. Vid det visade utforandet Or den plana Dlitremsans 11 tjocklek 0,25 mm, spaltens 16 vidd 0,30 mm och munstyckenas 17 och 18 diameter 1 mm. The possibility of movement of the rocker beam is limited by means of stops not shown, so that unnecessary oscillating movements are prevented. The stops are so covered that the left side of the rocker beam according to Fig. 1 can pivot downwards so much that the flat plate strip 14 completely exposes the nozzles 17 and 18. The left side of the rocker beam can further pivot upwards so much that the flat plate strip 14 completely abuts the nozzles 17. and 18 and protrudes slightly above these. The balance stroke for a given recovery cycle Or arranged to occur when the back pressure, which arises as a result of the flat plate strip 14 partially thanking the nozzles 17 and 18, has a fixed value at night. The stop Oro is suitably arranged in such a way that the possibility of movement of the vagal beam corresponds to the weighting of the last 10-20% of the net weight which it is desired to weigh. In the embodiment shown, the thickness of the flat Dlit strip 11 is 0.25 mm, the width of the gap 16 is 0.30 mm and the diameter of the nozzles 17 and 18 is 1 mm.

BaIgen 6 uppbars av en lagesfast del av vagen (se fig. 1) och Or Over en ventil B ansluten till en oljeseparator 20. Under standardvikten W Or en pneumatisk cylinder 21 anordnad, vilken innesluter en kolv 22, som nar den befinner sig i sitt ovre vandlage lyfter standardvikten W frau vagskalen 7. Vid sidan em kolvens 22 kolvstang finns ett utsprang 23, vilket är anordnat att nar det rOr sig i vertikalled manovrera ventiler F och G. Dessa ventiler tryckbelastas, nar utspranget 23 kommer till anliggning mot dem. The body 6 is supported by a layered part of the carriage (see Fig. 1) and over a valve B connected to an oil separator 20. Under the standard weight W Or a pneumatic cylinder 21 is provided, which encloses a piston 22, which when in its position The upper water level lifts the standard weight W from the cradle shell 7. Next to the piston rod of the piston 22 there is a projection 23, which is arranged to maneuver valves F and G vertically in the vertical direction.

Den pneumatiska kretsen innefattar normala treportsventiler A, B, C, D, E, F och G samt 1:1-relaer N och V. Kretsen innefattar aven tva precisionsrelaer P1 och P2. Relaet P1 arbetar vid tryck over 1,05 at och relaet P2 arbetar vid tryck under 1,12 at. Den pneumatiska kretsen matas frail tre tryckluftkallor, en pa 5,5-7 at, en pa 1,75 at och en pa 2,1 at. Tryckkallan ph 5;5-7,0 at anvands for manovrering av hylsventilen 9 under inverkan av relaet V. Tryckkallan pa 2,1 at Or Over en styrning 11„ ansluten till tryckregulatorn 13. Mottrycket i tryckregulatorn 13 har ett minimivarde, nar den plana platremsan 11 helt frilagger munstyckena 17 och 18, och stiger, nar platremsan rtir sig uppat och tacker en alit stOrre del av dessa munstycken. Mottrycket styr relb.et N sa, att luft vid samma tryck som mottrycket i tryckregulatorn 13 frail tryckkallan pa 1,75 at tillfors till relaerna P, och P2, till en av portarna i ventilen E, genom vilken luften nar ventilen Or tryckbelastad passerar till relaet V, som darigenom bringas att fran hogtryckskallan slappa fram luft vid samma tryck som mottrycket, samt slutligen till oljeseparatorn 20, sO att olja bringas att stromma till eller frail balgen 6 Over ventilen B. The pneumatic circuit comprises normal three-port valves A, B, C, D, E, F and G as well as 1: 1 relays N and V. The circuit also comprises two precision relays P1 and P2. Relay P1 operates at pressures above 1.05 at and relay P2 operates at pressures below 1.12 at. The pneumatic circuit is fed from three compressed air sources, one at 5.5-7 at, one at 1.75 at and one at 2.1 at. The pressure source ph 5; 5-7.0 at is used for maneuvering the sleeve valve 9 under the influence of the relay V. The pressure source of 2.1 at Or Over a control 11 „connected to the pressure regulator 13. The back pressure in the pressure regulator 13 has a minimum value when the plate strip 11 completely exposes the nozzles 17 and 18, and rises when the plate strip moves upwards and thanks an alit larger part of these nozzles. The back pressure controls the relb. relay V, which is thereby caused to release air from the high-pressure head at the same pressure as the back pressure, and finally to the oil separator 20, so that oil is caused to flow to or frail the bellows 6 over the valve B.

Vart och ett av 1:1-relaerna N och IT utgors i huvudsak av ett slutet karl, som medelst ett bojligt membran Or uppdelat i tva. kammare. Till den ena kammaren, vilken utgor relaets styrkammare, tillfors luft vid ett styrtryck, i foreliggande fall mottrycket i tryckregulatorn 13. Den andra kammaren Or ansluten till en kalla for tryckluft med hogre tryck On det maximala styrtrycket, i foreliggande fall 1,75 at. Tryckluftkallan Or ansluten till den namnda andra kammaren Over en liten kulventil, vilken manlivreras av membranet. Den namnda andra kammaren Or forsedd med ett avlastningsmunstycke, genom vilket overskott pa luft kan avga till atmosfaren. Under jamviktsforhallanden inter membranet ett sadant lage, att kulventilen per tidsenhet slapper fram en lika stor luftmangd som den, som kan avga genom avlastningsmunstycket. Trycken ph hada sidor om membranet bli ddrigenom i huvudsak lika store. Den namnda andra kammaren Or Oven ansluten till en avgivningsledning, genom vilken fOrhallandevis stora mangder luft med samma tryck som styrtrycket kan avga frail relaet. Pneumatiska relaer av delta slag finnas tillgangliga ph marknaden. Each of the 1: 1 relays N and IT consists essentially of a closed vessel, which by means of a flexible membrane Or is divided into two. chamber. To one chamber, which constitutes the control chamber of the relay, air is supplied at a control pressure, in this case the back pressure in the pressure regulator 13. The other chamber Or connected to a cold for compressed air with higher pressure On the maximum control pressure, in this case 1.75 at. Compressed air source Or connected to the said second chamber Over a small ball valve, which is supplied by the diaphragm. The said second chamber Or is provided with a relief nozzle, through which excess air can escape to the atmosphere. Under equilibrium conditions, the diaphragm is in such a position that the ball valve per unit of time releases an equal amount of air as that which can emit through the relief nozzle. The pressures ph hada sides of the membrane thereby become substantially equal. The said second chamber Or Oven is connected to a discharge line, through which relatively large amounts of air with the same pressure as the control pressure can discharge frail relay. Pneumatic relays of the delta type are available ph the market.

Det Or uppenbart att reldet pa kant satt kan anordnas sh, att den genom avgivningsledningen avgaende luften erhaller ett tryck, som star i ett faststallt forhallande till styrtrycket. Detta forhallande kan vara storre eller mind-re On 1. It is obvious that the line on the edge can be arranged so that the air emitting through the discharge line receives a pressure which is in a fixed relation to the control pressure. This ratio can be greater or lesser On 1.

Tryckkallan pa 1,75 at, vilken Over reldet N Or ansluten till ventilens E normalt isolerade port, Or Oven ansluten till ventilens E nor-malt inkopplade port, sa att trycket pa 1,75 at tillfors till relaet V. nar ventilen E Or obelastad. Tryckkallan pa 1,75 at Or Oven ansluten till en av portarna i ventilen C, vilken, nar den Or tryckbelastad, slapper fram ett tryck pa 1,75 at till ventilen E for tryckbelastning av denna. Nar ventilen C Or tryckbelastad, slapper den aven fram det namnda trycket till en av portarna i ventilen A, vilken ventil, nar den Or obelastad, tillfor trycket till ventilen C och salunda hailer denna tryckbelastad. Nar ventilen C Or obelastad, star dess utlopp i forbindelse med atmosfaren. Tryckkallan pa 1,75 at, Or Oven ansluten till en av portarna i precisionsreldet P,, vilket Or inkopplat pa- 3 rallellt med ventilen C. Trycket pa 1,75 at till-for, nar reldet Pi är tryckbelastat, till ventilen A for tryckbelastning av denna och parallellt darmed till en av portarna i relaet P2. När det sistnamnda relaet är tryckbelastat, tillfOrs trycket pa-1,75 at till en av portarna i ventilen G. Nar ventilen G är tryckbelastad, tillfors trycket pa 1,75 at till en av portarna i ventilen A, varifran detta tryck, nar ventilen A ar tryckbelastad, tillfors till ventilen C for tryckbelastning av denna. The pressure source of 1.75 at, which is above the N or connected to the normally insulated port of the valve E, or above also connected to the port of the valve E normally connected, so that the pressure of 1.75 at is supplied to the relay V. when the valve E is unloaded . The pressure source of 1.75 at Or is connected to one of the ports in the valve C, which, when it is pressurized, releases a pressure of 1.75 at to the valve E for pressure loading thereof. When the valve C is pressurized, it also releases the said pressure to one of the ports in the valve A, which valve, when it is unloaded, supplies the pressure to the valve C and thus hails it pressurized. When valve C is unloaded, its outlet is connected to the atmosphere. The pressure source of 1.75 at. pressure load thereof and parallel thereto to one of the gates in relay P2. When the latter relay is pressurized, the pressure pa-1,75 at is applied to one of the ports in the valve G. When the valve G is pressurized, the pressure of 1.75 at is applied to one of the ports in the valve A, from which this pressure, when the valve A is pressure loaded, supplied to valve C for pressure loading thereof.

Tryckkallan pa. 1,75 at är aven ansluten till en tryckknappsventil PB, vilken är inkopplad parallellt med ventilen C och relaet P1. Nar tryckknappsventilen ar obelastad, tillfors trycket pa 1,75 at till en av portarna i ventilen D, varifran det, nar ventilen D är tryckbelastad, tillfors till ventilerna D och B for tryckbelastning av dessa och till den pneumatiska cylindern 21. Pressure cold on. 1.75 at is also connected to a push-button valve PB, which is connected in parallel with the valve C and the relay P1. When the pushbutton valve is unloaded, the pressure of 1.75 at is supplied to one of the ports in the valve D, from which, when the valve D is pressurized, it is supplied to the valves D and B for pressure loading thereof and to the pneumatic cylinder 21.

Det är uppenbart att standardvikten W till foljd av vagskalens 7 och plattformens 8 olika .avstand till stodet 2 maste avpassas sa, att den ger samma moment kring stodet 2 som den nettovikt, som man onskar vaga upp. It is obvious that the standard weight W as a result of the different distances of the scales 7 and the platform 8 to the post 2 must be adjusted so that it gives the same torque around the post 2 as the net weight which one wishes to weigh up.

Tillstand resp operation Plattformen tom Behallaren placeras pa plattformen. Tryckknappen trycks ned. Systemet borjar ut- balanseringen med tom behallare Standardvikten i vagskalen och systemet utbalanserat Standardvikten lyfts Standardvikfen helt lyftad. Matningen bbrjar Mottrycket i styrkammaren nar vardet 1,05 at Den fyllda behallaren avlagsnad Anordningens arbetssatt skall nu beskrivds i detalj: Vid normal anvandning är ventilen D tryckbelastad vid slutet av en uppvagningscykel, sa att luft frau tryckkallan pa 1,75 at tillfors till den pneumatiska cylindern 21, varigenom kolven 22 halls i det upplyftade laget, i vilket den hailer standardvikten W upplyftad fran vagskalen 7. Samtidigt halls ventilen B tryckbelastad, varigenom den oljefyllda balgen 6 halls sluten. Condition or operation The platform empty The container is placed on the platform. The pushbutton is pressed. The system starts balancing with an empty container The standard weight in the cradle shell and the system balanced The standard weight is lifted The standard weight is fully lifted. The supply starts the cylinder 21, whereby the piston 22 is held in the raised layer, in which it holds the standard weight W raised from the carriage shell 7. At the same time, the valve B is kept pressurized, whereby the oil-filled bellows 6 is kept closed.

Nar en fylld behallare avlagsnas frail plattformen 8, svanger vagbalkens vanstra sida enligt fig. 1 neat, varigenom mottrycket i tryckregulatorn 13 sjunker. En tom behallare placeras sedan pa plattformen 8, varefter tryckknappsventilen PB manOvreras. Av den Rdjande tabellen framer de olika ventilernas tillstand under vane fas av uppvagningen. Det framer av tabellen att nar tryckknappsventilen PB manovreras avlastas ventilerna D och B, varigenom den oljefyllda balgen 6 for-binds med oljeseparatorn 20 och den undre delen av cylindern 21 forbinds med atmosfaren. When a filled container is removed from the frail platform 8, the left side of the cradle beam according to Fig. 1 swings neatly, whereby the back pressure in the pressure regulator 13 decreases. An empty container is then placed on the platform 8, after which the pushbutton valve PB is operated. The condition of the various valves during the usual phase of washing up emerges from the table. It appears from the table that when the push-button valve PB is operated, the valves D and B are relieved, whereby the oil-filled bellows 6 is connected to the oil separator 20 and the lower part of the cylinder 21 is connected to the atmosphere.

Ventiltillstand ABCDEF GPI.P2 Kolvens 22 lage resp rorelse 1 2 1 2 1 2 1 1 2 Uppe 1 1 1 1 1 1 1 1 2 BOrja rOra sig nedat 2 2 2 2 2 1 2 2 2 AD.da nere 1 2 2 2 2 1 1 1 2 flora sig uppat 1 2 2 2 2 2 1 1 2 Anda uppe 2 2 1 2 1 2 1 2 2 Anda uppe 1 2 1 2 1 2 1 1 2 Anda uppe Ventiltillstand 1 = Ventilen obelastad Ventiltillstand 2 = Ventilen tryckbelastad Balgens 6 och fjaderns 3 fjaderkonstanter Oro sá avpassade, att balgen och salunda Oven vagbalkens vanstra sida enligt fig. 1 vid vilken som heist andring Mom ett faststallt omrade, exempelvis 0-0,5 kg eller 25-25,5 kg, av den pa vagbalkens hogra sida verkande vikten for-mar rora sig sa, att mottrycket i tryckregulatorn uppratthalls vid eller aterfors till ett varde, vilket ligger inom 0,07 at fran det faststallda varde, som svarar mot vagbalkens j amviktslage, dvs. onskad nettovikt pa plattformen 8. Valve condition ABCDEF GPI.P2 Flask 22 low resp rorelse 1 2 1 2 1 2 1 1 2 Upper 1 1 1 1 1 1 1 1 2 BOrja rOra sig nedat 2 2 2 2 2 1 2 2 2 AD.da nere 1 2 2 2 2 1 1 1 2 flora up 1 2 2 2 2 2 1 1 2 Breath up 2 2 1 2 1 2 1 2 2 Breath up 1 2 1 2 1 2 1 1 2 Breath up Valve condition 1 = Valve unloaded Valve condition 2 = Valve pressure-loaded The bellows 6 and the spring 3 constant of the bellows Oro so adapted that the bellows and salunda Oven the left side of the cradle beam according to fig. the weight acting on the right-hand side of the rocker beam moves so that the back pressure in the pressure regulator is maintained at or returned to a value, which is within 0.07 of the determined value, which corresponds to the balance beam of the balance beam, ie. desired net weight on the platform 8.

Tryckregulatorn 13, balgen 6 och fjadern 3 verka tillsammans sa, att vagbalkens rorelse, ndr den pa vagen verkande vikten varierar Mom ett faststallt orarade, begransas till en mycket liten rorelse. En eventuell variation i den tomma behallarens vikt kompenseras darfor automatiskt under inverkan av balgen, vilken begransar vagbalkens rorelse pO. grund av variation i taran, i sadan grad, att vagningen kan fortsatta utan att noggrannheten gar forlorad. Som exempel kan namnas att nar mottrycket i tryckregulatorn 13 automatiskt 4 aterstalls till ett varde, som avviker hogst 0,07 at fran det faststallda mottrycket 1,05 at, medfor detta i en anordning av beskrivet slag att systemet balanseras pa hogst 10 g när vid en variation i taran pa 0,5 kg. Anordningen kan salunda anvandas f8r automatisk tare-ring endast om taran varierar Mom ett faststallt omrade. Om taran ligger utanfOr detta omrade, sakerstaller den i det foljande beskrivna lasanordningen att vagningen icke kan fortsatta. The pressure regulator 13, the bellows 6 and the spring 3 act together in such a way that the movement of the carriage beam, when the weight acting on the carriage varies, but a fixed distance, is limited to a very small movement. Any variation in the weight of the empty container is therefore compensated automatically under the influence of the bellows, which limits the movement of the cradle beam pO. due to variation in the taran, to such an extent that the weighing can continue without the accuracy being lost. As an example it can be mentioned that when the back pressure in the pressure regulator 13 is automatically reset to a value which deviates at most 0.07 at from the determined back pressure 1.05 at, this means in a device of the type described that the system is balanced at a maximum of 10 g when a variation in taran of 0.5 kg. The device can thus be used for automatic tare only if the tare varies within a fixed range. If the taran is outside this area, the lasing device described below states that the weighing cannot continue.

Nar tryckknappsventilen PB manovreras, borjar utbalanseringen av systemet genom att olja tillfors till eller bortfors fran balgen 6, sa att trycket dari blir detsamma som mottrycket i tryckregulatorn 13. Samtidigt nor sig kolven 22 nedat och avlamnar darvid standardvikten pa vagskalen 7. Nar kolven ror sig nedat, frigors forst ventilen F, varefter kolven fortsatter att rora sig nedat till ingrepp med ventilen G. When the pushbutton valve PB is maneuvered, the balancing of the system begins by supplying oil to or away from the bellows 6, so that the pressure there is the same as the back pressure in the pressure regulator 13. At the same time the piston 22 reaches downwards. down, valve F is first released, after which the piston continues to move down into engagement with valve G.

Nar standardvikten avlamnas pa vagskalen, svanger vagbalkens vanstra sida uppat, varigenom mottrycket i tryckregulatorn 13 stiger. Relaet N verkar da sâ, att trycket i balgen 6 stiger och vagbalkens lage inregleras, tills den kraft, varmed balgen verkar pa havstangen 4, utbalanserar den kraft, varmed i fjadern verkar darph, da inregleringen avslutas. Mottrycket i tryckregulatorn 13 ligger da sa nara det faststallda vardet, att balken i praktiken befinner sig i sitt jamviktslage. Detta svarar mot tillstand 3 enligt tabellen. When the standard weight is unloaded on the cradle shell, the left side of the cradle beam swings upwards, whereby the back pressure in the pressure regulator 13 rises. The relay N then acts in such a way that the pressure in the bellows 6 rises and the position of the cradle beam is adjusted until the force with which the bellows acts on the sea rod 4 balances the force with which the spring appears to be darp when the adjustment is completed. The back pressure in the pressure regulator 13 is then so close to the established value that the beam is in practice in its equilibrium position. This corresponds to state 3 according to the table.

Nar janavikt har uppnatts, tryckbelastas precisionsrelaerna P1 och P2, varigenom ventilen A 'tryckbelastas. Emedan kolven 22 befinner sig arida nere, sa att utspranget 23 an-griper ventilen G, tillfors luft vid ett tryck av 1,75 at genom relaerna P, och P2 och ventilerna G och A till ventilen C och aven genom en strypning RD till ventilerna D och B. Tryckbelastningen av ventilen B medfor att balgen 6 lases i sitt lage och tryckbelastningen av ventilen D medfor att luft vid ett tryck av 1,75 at genom ventilen D tillfors till cylindern 21, sa att kolven 22 bringas att rtira sig uppat och lyfta standardvikten fran vagskalen. Ventilen D hailer sig sjalv i det tryckbelastade laget och kan endast avlastas tillsammans med ventilen B genom manovrering av tryckknappsventilen PB. Ventilen B kan icke tryckbelastas, savida icke hada precisionsrelaerna P1 och P2 aro' tryckbelastade, nar jamvikt uppnas omedelbart efter inregleringen. Detta innebar i praktiken att anordningen icke kan anvandas for behallare med en vikt utanfor det faststailda omradet for taran. When the Jana weight has been reached, the precision relays P1 and P2 are pressurized, whereby the valve A 'is pressurized. While the piston 22 is down, so that the projection 23 engages the valve G, air is supplied at a pressure of 1.75 at through the relays P, and P2 and the valves G and A to the valve C and also through a choke RD to the valves D and B. The pressure load of the valve B causes the bellows 6 to be read in its position and the pressure load of the valve D causes air at a pressure of 1.75 at through the valve D to be supplied to the cylinder 21, so that the piston 22 is caused to rotate upwards and lift the standard weight from the scale. The valve D hails itself in the pressure-loaded layer and can only be relieved together with the valve B by maneuvering the push-button valve PB. Valve B can not be pressure-loaded, unless the precision relays P1 and P2 are pressure-loaded, when equilibrium is reached immediately after balancing. This meant in practice that the device could not be used for containers with a weight outside the fixed range for taran.

Nar standardvikten lyfts fran vagskalen 7, avlastas ventilen G. Vagbalkens 1 vanstra sida svanger nedat och mottrycket i tryckregula torn 13 sjunker darigenom under det faststallda vardet, varigenom relaet P1 avlastas. Detta svarar mot tillstand 4 enligt tabellen. When the standard weight is lifted from the cradle shell 7, the valve G is relieved. This corresponds to state 4 according to the table.

Nar standardvikten her lyfts fran vagskalen 7, kvarblir vagbalken i det fran jamviktslaget avvikande laget, ty balgen 6 är nu isolerad fran den pneumatiska kretsen och formar icke langre paverka vagbalkens lage. Nar kolyen 22 är anda uppe, angriper utspranget 23 ventilen F. Ventilen A är darvid avlastad (till-stand 5 enligt tabellen) men ventilen C forblir tryckbelastad pa grund av anslutningen till tryckluftkallan. pa1,75 at. ;liven ventilerna B, D och E fOrbli tryckbelastade. When the standard weight here is lifted from the cradle shell 7, the cradle beam remains in the layer deviating from the balance weight, because the bellows 6 is now isolated from the pneumatic circuit and no longer forms to affect the bearing of the cradle beam. When the cooler 22 is up, the projection 23 attacks the valve F. The valve A is then relieved (condition 5 according to the table) but the valve C remains pressurized due to the connection to the compressed air source. pa1.75 at. The valves B, D and E remain pressurized.

Nar ventilen E frail och med tillstand 3 enligt tabellen är tryckbelastad, styrs hylsventilen 9 av mottrycket i tryckregulatorn 13 via relaerna N och V. For att stromningsmotstandet genom hylsventilen 9 skall lianas lagt är relaet N anordnat att medge lufttillforsel till hylsventilen endast nar mottrycket i tryckregulatorn 13 är 0,3 at eller hogre. Nar standardvikten lyfts Iran vagskalen, sjunker Mottrycket i tryckregulatorn 13 till att borja med, varfor trycket i hylsventilens tryckkammare 12 sjunker, sa att materialtillforseln kan btirja. Nar mottrycket i tryckregulatorn 13 blir hogre an 0,3 at, stiger trycket i hylsventilens tryckkammare, varigenom tillforselhastigheten nedbringas. Tryckregulatorn 13 är sâ placerad i forhallande till vagbalken, att mottrycket dari icke borjar stiga, forran det tillfOrda materialets vikt pa nagot kilo nar uppgar till den onskade nettovikten. Nar mottrycket uppnar det faststallda vardet 1,05 at, tryckbelastas precisionsrelaet P1, varigenom ventilen A tryckbelastas, vilket i sin tur med- for att ventilenavlastas genom ventilerna A, G och F. Nar ventilen C avlastas, avlastas aven ventilen E, varigenom hela trycket pa 1,75 ato tillfors till hylsventilen, sh att denna stanger helt (tillstand 6 enligt tabellen). Strypningen 11„ sakerstaller att ventilerna D och B forbli tryckbelastade, nar ventilen C avlastas. When the valve E is frail and with condition 3 according to the table is pressure loaded, the sleeve valve 9 is controlled by the back pressure in the pressure regulator 13 via the relays N and V. 13 is 0.3 at or higher. When the standard weight is lifted by the Iran scale, the back pressure in the pressure regulator 13 drops to begin with, causing the pressure in the pressure chamber 12 of the sleeve valve to drop, so that the material supply can begin. When the back pressure in the pressure regulator 13 becomes higher than 0.3 at, the pressure in the pressure chamber of the sleeve valve rises, whereby the supply speed is reduced. The pressure regulator 13 is positioned so in relation to the cradle beam that the back pressure therein does not begin to rise until the weight of the supplied material of a few kilograms reaches the desired net weight. When the back pressure reaches the set value 1.05 at, the precision relay P1 is pressurized, whereby the valve A is pressurized, which in turn means that the valve is relieved through the valves A, G and F. When the valve C is relieved, the valve E is also relieved, whereby the entire pressure pa 1.75 ato is supplied to the sleeve valve, sh that this closes completely (condition 6 according to the table). The throttle 11 „ensures that the valves D and B remain pressurized when the valve C is relieved.

Mr den fyllda behallaren avlagsnas fran plattformen 8, sjunker mottrycket i tryckregulatorn 13, varigenom precisionsrelaet Pi avlastas. Darigenom nas tillstand 7 enligt tabellen, vilket an detsamma som utgangstillstandet 1. When the filled container is removed from the platform 8, the back pressure in the pressure regulator 13 decreases, whereby the precision relay Pi is relieved. As a result, state 7 according to the table, which is the same as the initial state 1.

Precisionsrelaet P2 har till funktion all forhindra att materialtillforseln paborjas, om vid den automatiska tareringen ett alltfor h8gt mottryck skulle uppsta i tryckregulatorn 13 eller om taran ligger -Over det faststallda Maximivardet. The function of the precision relay P2 is to prevent the material supply from being drilled, if during the automatic tare an excessively high back pressure should arise in the pressure regulator 13 or if the tare is above the set maximum value.

Vid den i det foregaende beskriVna utforingsformen av en anordning enligt foreliggande uppfinningen innefattar tryckregula- torn en kammare med Oppningar, genom vilka tryckluft fran en gemensam kalla utstrommar vid motsatta sidor om en spalt och forbi vilka ett till vagen hOrande element är rorligt for att avbryta eller forsvara luftutstromningen. En anordning av detta slag ãr speeiellt ty genom Idmpligt val av oppningarnas storlek, spaltens vidd och det rarliga elementets tjocklek kan man fa det mottryck, som uppstar i kammaren, att variera hOgst avsevart aven till foljd av mycket -smb. rOrelser hos det rorliga elementet. Vidare har en anordning av detta slag den fordelen, att lufttrycket icke har flagon inverkan pa det till vagen horande elementets rorelser, emedan det verkar pa hada sidor om detta element. Vida-re kunna sadana vibrationer, som eventuellt uppsta i elementet, när detta befinner sig nara oppningarna, knappast skada dessa, ty elementet är fritt att rora sig forbi Oppningarna i bada riktningarna. In the embodiment of a device according to the present invention described above, the pressure regulator comprises a chamber with openings, through which compressed air from a common cold flows out at opposite sides of a gap and past which an element belonging to the carriage is movable to interrupt or defend the air outflow. A device of this kind is special because by simply selecting the size of the openings, the width of the gap and the thickness of the strange element, one can get the back pressure which arises in the chamber to vary at most considerably also due to a lot of -smb. movements of the moving element. Furthermore, a device of this kind has the advantage that the air pressure does not have a flawed effect on the movements of the element belonging to the carriage, since it acts on both sides of this element. Furthermore, such vibrations, which may arise in the element, when it is near the openings, can hardly damage them, for the element is free to move past the openings in both directions.

Tryckregulatorn kan naturligtvis utforas pa annat satt an det ovan beskrivna. Sa kan exempelvis en luftstrom, som utstr8mmar fran ett munstycke, riktas direkt mot vagbalken, sit att luftutstromningen minskas och mottrycket darigenom okas, ndr vagbalken svanger set, att en alit storre del av munstycket tacks. The pressure regulator can of course be designed in a different way from that described above. For example, an air stream which flows out of a nozzle can be directed directly towards the rocker beam, so that the air flow is reduced and the back pressure is thereby increased, when the rocker beam converts, that an alit larger part of the nozzle is thanked.

De lasmedel, som dro anordnade att under inverkan av mottrycket i styrkammaren lasa regleranordningarna efter inregleringen, innefatta lampligen en pneumatisk omkastare, vilken är anordnad att vaxla fran ett tillstand till ett annat, nar en faststalld tryckandring sker i tryckkammaren, och vilken befinner sig i det ena tillstandet Indian tva faststallda tryck och i det andra tillstandet vid tryck Over det hogre av de tva faststallda trycken eller under det lagre av dessa tva tryck. Vid en foredragen utforingsform innefatta lasmedlen preeisionsrelaer, av vilka det ena är anordnat att vaxla frail ett tillstand till ett annat vid en faststalld tryekandring och det andra är anordnat att vaxla frail ett tillstand till ett annat vid en annan faststalld tryckandring, varvid den pneumatiska kretsen är sa anordnad, att regleranordningarna lasas till foljd av en kombination av relaernas tillstand melIan de tva faststallda trycken, vilken kombination medfor att en pneumatisk ventil manOvreras set, att balgen isoleras. Lampligen anvãndas tva relder, som hada befinna sig i samma tillstand mellan de tva trycken, dvs. som hada aro tryckbelastade eller avlastade. The welding means which, under the influence of the back pressure in the control chamber, are arranged to read the control devices after the balancing, suitably comprise a pneumatic diverter, which is arranged to shift from one state to another, when a fixed pressure change takes place in the pressure chamber, and which is located therein. one state Indian two fixed pressures and in the other state at pressure Above the right of the two fixed pressures or below the lower of these two pressures. In a preferred embodiment, the welding means comprise precision relays, one of which is arranged to switch frail one state to another at a fixed pressure change and the other is arranged to switch frail one state to another at another fixed pressure change, the pneumatic circuit being so arranged that the control devices are read as a result of a combination of the condition of the relays between the two fixed pressures, which combination means that a pneumatic valve is operated and that the bellows is insulated. Lamply, two rails are used, which would have been in the same state between the two pressures, ie. which had aro pressure-loaded or unloaded.

En anordning enligt foreliggande uppfinning kan liven anvandas till andra slag av gar an den ovan beskrivna balansvagen med en vagbalk. Den kan exempelvis anvandas till en vag med en i ena anden inspand eller svangbart lagrad vagbalk. Ndr inregleringen av vagen sker genom installning av en fjaders lage, kan den stallbara fjadern utgoras av en hjalpfjader, forutom vilken va.gen innefattar en huvudfjader, som upptar den storsta delen av belastningen pO. vagen. A device according to the present invention, the webs can be used for other types of yarns than the above-described balance weigher with a cradle beam. It can, for example, be used for a cradle with a cradle beam or pivotally mounted cradle beam. When the balancing of the carriage takes place by installing a spring of the spring, the adjustable spring can be constituted by an auxiliary spring, in addition to which the carriage comprises a main spring, which absorbs the largest part of the load pO. vagen.

Vid det i det foreghende beskrivna utforandet anvands en hylsventil for styrning av materialtillforseln till behallaren. Denna ventil innefattar en elastisk hylsa, genom vilken materialet kan stromma och vilken omges av ett stelt holje, som tillsammans med den elastiska hylsan innesluter en tryckkammare. Till denna kan tryckluft tillforas och bortforas f6r minskning resp. okning av den fria genomstromningsarean genom den elastiska hylsan. En hylsventil av detta slag är speciellt lamplig att anvandas till en pneumatisk anordning enligt foreliggande uppfinning for styrning av materialtillforseln till en vag. Om en dylik ventil anvands, kan namligen hela systemet gams pneumatiskt och till f8ljd damav forhallandevis enkelt. Ventilen arbetar med god noggrannhet och minskar materialtillfOrseln kontinuerligt, nar uppvagningsfasen Bar-mar sig sitt slut, varfor uppvagningen kan ske med sma toleranser. En hylsventil av ovan beskrivet slag foredrages darfOr i en anordning enligt foreliggande uppfinning. In the embodiment described above, a sleeve valve is used for controlling the supply of material to the container. This valve comprises an elastic sleeve, through which the material can flow and which is surrounded by a rigid housing, which together with the elastic sleeve encloses a pressure chamber. To this, compressed air can be supplied and removed for reduction resp. increasing the free flow area through the elastic sleeve. A sleeve valve of this kind is particularly suitable for use in a pneumatic device according to the present invention for controlling the supply of material to a vane. If such a valve is used, the whole system can be pumped pneumatically and consequently relatively easily. The valve works with good accuracy and reduces the material supply continuously, when the dishwashing phase ends, so the dishwashing can take place with small tolerances. A sleeve valve of the type described above is therefore preferred in a device according to the present invention.

Det är emellertid uppenbart att aven andra slags anordningar kunna anvandas for att begransa och avbryta materialtillforseln. Man kan exempelvis lata det pneumatiska systemet styra en elektrisk krets pa sa salt, att kretsens utgangsspanning okar med tilltagandc mottryck. Man later da. utgangsspanningen styra en ventil eller annan anordning, som reglerar den hastighet, varmed materialtillforseln till vagen sker. Man kan exempelvis anvanda en vibrerande tillforselanordning, varvid dennas amplitud och salunda aven tillforselhastigheten styrs av utgangsspanningen. However, it is obvious that other types of devices can also be used to limit and interrupt the supply of material. For example, the pneumatic system can be allowed to control an electrical circuit on such a salt that the output voltage of the circuit increases with increasing back pressure. Man later da. the output voltage controls a valve or other device which regulates the speed at which the material supply to the carriage takes place. For example, a vibrating supply device can be used, the amplitude of which and thus also the supply speed being controlled by the output voltage.

Claims

Patent claim: Automatic net scale with pneumatic control of taring and mailing, the tarring being regulated by the back pressure formed in an air pressure chamber by the movement of a rocker beam in relation to an outflow opening in the compressed air chamber, characterized in that the rocker beam (1) supported a platform or similar (8) for the container to be filled, and a cradle shell (7) for a standard weight (W) with the same weight as the desired net weight, a valve-controlled piston-type lifting device (21, 22) being provided for lifting the standard weight ( W) from the shell shell, 6 and a tare-compensating vessel (20) with pressurized liquid is connected to a bellows (6) in such a way that liquid can be transferred from the vessel (20) to the bellows (6) or vice versa, the air pressure above the liquid in the vessel (20) is regulated, for example by means of a pneumatic relay (N), by the pressure in the compressed air chamber (13), so that the liquid pressure in the bellows (6) is varied according to variations in the back pressure in the compressed air chamber (13), and h wherein the Wigan (6) is connected to the cradle beam (1) via an elastically extendable connecting member (3), for example a spring, preferably by means of a sea arm (4), in such a way that movement of the bellows (6) to follow of liquid transfer between it and the compensating vessel (20) during tareing returns the cradle beam (1) to zero with respect to the compressed air chamber (13). Request publications: Patents! Rem France 1,207,688; Germany 953 663; USA 2 634080, 2 755 057. Agent: Ing. M Kierkegaard, Stockholm Stockholm 1966. Kungl. Boktr. P. A. Norstedt & & incr. 660006 1 FIG. I 175oZ —3 5.5-70 12 -ET1 2

2.1 Alirnos: k Tychknappsienhl GENERAL STAB