baber/WOPTO huggingface dataset:
Patent GB-803689-A (GB)
Title: Process for separating gaseous or vaporous substances more especially isotopes
IPC: B01D59/18
Filed: 1956-09-27
Abstract: <PICT:0803689/III/1> In the process for separating gaseous or vaporous mixtures of different molecular weight or molecular diameter, e.g. isotopes, described in Specification 794,834, in which the mixture issues from a nozzle to form an expanding jet of gases which are divided by an apertured diaphragm into a peripheral portion and a core portion, the streams of gases are produced by evaporation before the separation system, and thereafter are condensed.  The condensed separated gases may be re-vaporized through the system and further separations effected.  A suitable apparatus for multi-stage treatment, Fig. 1b, a number of separating elements 14, 15, 16 are disposed as a helix on a central hollow shaft 12 rotatably mounted in an evacuated vessel 11.  Two series of vessels 112 . . . 118 are provided with heating and cooling coils and feed pipes for the gaseous mixture, and project into the chamber 11.  The heated gases flow through a pipe connection 120 to the separating element 15 and the two gas fractions are collected in separate cooled vessels in the same plane as the heated vessel.  The central pipe 12 is then rotated to connect the cooled gas chambers through upper separating elements to two further cooled vessels, and the process repeated by heating the first stage condensates and condensing the second stage separated gases.  The process may be applied to concentrating uranium isotopes from uranium hexafluoride, extracting the C13 isotope from ethylene glycol, and the N15 isotope from hydrazine, triazole, aniline and other organic N-compounds.
Patent GB-921956-A (GB)
Title: Improvements in or relating to electric fuses
Inventor: SIMMONDS HENRY
IPC: C08F10/00
Filed: 1958-09-16
Abstract: 921,956. Fuse contacts. ENGLISH ELECTRIC CO. Ltd. Aug. 31, 1959 [Sept. 16, 1958], No. 29580/58. Class 38 (5). [Also in Group XXXVI] To prevent arcing when an electric fuse of the mechanically tightened type is inserted on load, an initial pressure between the contacts of the fuse carrier and the fuse base is provided during insertion by a spring member carried by one of the contacts of each mating pair, the contacts being subsequently clamped together by mechanical means such as wedges. As shown, a conducting spring 21 screwed to a machined part of a U-shaped contact 13 urges an inserted base contact 23 against an arm of contact 13 and the pressure is increased by a wedge 14 moved by a screw 15. A fuse 17 is connected between two contacts 13 by bolts 18 engaging tabs 19 on the fuse.
Patent GB-739139-A (GB)
Title: Manufacture of 17-hydroxy-20-ketosteroids
IPC: C07J5/00
Filed: 1953-10-26
Abstract: 17 - Hydroxy - 20 - keto - steroids are prepared by reacting a 16 : 17-oxido-20-keto-steroid with a salt of hydrogen iodide and an organic carboxylic or sulphonic acid, and the 16-iodo-17-hydroxy-20-keto-steroid thus produced is catalytically reduced to eliminate the 16-iodo substituent.  The reaction may be carried out in an inert solvent in which the salt of hydrogen iodide in soluble e.g. low molecular weight alcohols, dioxane or ketones such as acetone, also in admixture with water.  Suitable organic acids are lower aliphatic carboxylic acids such as formic, acetic and propionic acids, and p-toluene sulphonic acid.  Alkali and alkaline earth metal iodides may be used in the reaction, e.g. sodium, potassium and calcium iodides.  Reactants referred to are the 16 : 17-oxido derivatives of D 5 - pregnene - 3b  - ol - 20 - one and the acetate thereof, D 4 - pregnene - 21 - ol - 3 : 20-dione acetate, progesterone, D 5 - pregnene-3b  : 21 - diol - 20 - one - diacetate, allopregnane-3b  : 21 - diol - 20 - one diacetate, pregnane-3a  : 21 - diol - 20 - one diacetate, pregnane-3a  - ol - 20 - one acetate, allopregnane - 3b -ol - 20 - one acetate, D 4 - pregnane - 11a  - ol-3,20 - dione and pregnane - 3a  : 21 - diol-11 : 20 - dione - 21 - acetate.  In the examples, 16 - iodo - D 5 - pregnene - 3b  : 17a  - diol - 20-one and the 3b -acetate thereof, 16-iodo-D 4-pregnene - 17a : 21 - diol - 3 : 20 - dione - 21-acetate, 16 - iodo - 17a  - hydroxy - progesterone, D 5 - pregnene - 3b  : 17a  - diol - 20 - one and the 3b  - acetate thereof, D 4 - pregnene-17a  : 21 - diol - 3 : 20 - dione - 21 - acetate and 17a -hydroxyprogesterone are prepared.  A dibromo-steroid of the formula <FORM:0739139/IV (b)/1> is obtained by treating 16 : 17-oxido-D 4-pregnene - 3b  - ol - 20 - one acetate with hydrogen bromide.
Patent GB-927789-A (GB)
Title: Improvements in and relating to high frequency systems
Inventor: ROBERTS ROBERT SYDNEY
IPC: H03H2/00
Filed: 1958-09-16
Abstract: 927,789. R.F. couplings. WOLSEY ELECTRONICS Ltd. Oct. 1, 1959 [Sept. 16, 1958], No. 29617/58. Class 40 (7). The circuit shown enables a triode or other valve 13 to be connected to a balanced source, e.g. an aerial. Terminal 12 is connected to a source of reference potential, e.g. earth.
Patent GB-777365-A (GB)
Title: Improvements in or relating to secondary alkyltoluenes
IPC: C07C6/12
Filed: 1954-10-15
Abstract: Meta-secondary alkyl toluenes and 1,3,5-di-secondary alkyl toluenes wherein the secondary alkyl group is isopropyl or secondary butyl are made by interacting toluene and mono-, di- or tri-isopropyl or sec.-butyl benzene, in the molar ratio of toluene to secondary alkyl groups of at least 0.5, with at least enough liquid hydrogen fluoride to form a separate acid phase and with at least 0.5 mol. of boron trifluoride per mol. of sec.-alkyl groups under anhydrous conditions at a temperature not above 40 DEG  C. for sufficient time, removing the hydrogen fluoride and boron trifluoride from the acid phase and fractionating the hydrocarbon mixture which remains.  In the recovery of high purity meta secondary alkyltoluene without back isomerization or disproportionation, it is preferred to displace the meta secondary alkyltoluene from its hydrogen fluoride-boron trifluoride complex by employing a polyalkylbenzene which forms a more stable complex. Such polyalkylbenzenes are exemplified by trialkylbenzenes such as mesitylene, tri-isopropylbenzene, 1,3,5-di-isopropyl - toluene and isodurene, tetra - alkyl - benzenes, pentamethylbenzene and hexamethylbenzene, the preferred displacer being di-isopropyl-or di-sec.-butyltoluene, according to the secondary alkyl group of the reactant, and 2-6 mols. of the displacer per mol. of secondary alkyltoluene are employed.  The solution of the secondary alkyltoluene in the displacer may be treated at once with 50-500 volume per cent of a hydrocarbon upon which hydrogen fluoride, boron trifluoride and the secondary alkyltoluenes have no action, preferably a paraffin of low b.pt., e.g. propane, butane, pentane or hexane.
Patent GB-922315-A (GB)
Title: New compounds useful in steroid synthesis and processes for the preparation thereof
IPC: C07J73/00
Filed: 1959-09-01
Abstract: The invention comprises the 18,11-lactones of 11b -hydroxy-13,17-secoetiocholan-17,18-dioic acids of the general formula <FORM:0922315/IV(a)/1> wherein R represents =O, or b -OH, a -H, the methyl ester of 3a -hydroxy-11-keto-13,17-seco-etiochol-12-en-17-oic acid of the formula <FORM:0922315/IV(a)/2> the 17,18-lactone of 3a ,11b -diacyloxy-18-hydroxy-13,17-seco-13a -etiocholan-17-oic acid of the formula <FORM:0922315/IV(a)/3> and 3a ,11b - diacyloxy-13,17- seco-etiocholan-17,18-dioic acid of the formula <FORM:0922315/IV(a)/4> and the preparation of a compound of the first formula wherein R represents b -OH, a -H (1) by treating 3a , 11b -dihydroxy-17-keto-17ahydroxymethylene- 18-nor-D-homo-13a -etiocholane of the formula <FORM:0922315/IV(a)/5> with alkaline hydrogen peroxide, and (2) by treating 3a ,11b -diacyloxy-17 -keto-18-nor-D-homo-13a -etiocholane of the formula <FORM:0922315/IV(a)/6> (which may be prepared by acylating the corresponding free 3a ,11b -dihydroxy compound) with an organic per-acid to form the 17,18-lactone of 3a ,11b -diacyloxy-18-hydroxy-13,17-seco-13a -etiocholan-17-oic acid of the third formula above, oxidising this lactone with a mixture of chromic and sulphuric acids to form 3a ,11b -diacyloxy-13,17-seco-etiocholan-17,18-dioic acid of the fourth formula above, and treating this compound with warm alkali and then acidifying, wherein in the above processes (1) and (2) the initial reactant is prepared from 3a -hydroxy-11-keto-13,17-secoetiochol-12-en-17-oic acid or the methyl ester thereof obtainable by esterifying the acid, e.g. by reacting the acid with a mixture of sulphuric acid and methanol and which has the second formula above, by a process described in Specification 922,316.
Patent GB-1036215-A (GB)
Title: Purification of glycerol solutions
Inventor: MARKINA NINA GRIGORJEVNA
IPC: C07C29/88
Filed: 1963-07-26
Abstract: Aqueous solutions of glycerol containing tungstic acid are purified by adding calcium chloride and filtering off the calcium tungstate formed.  The glycerol solution is preferably at a temperature of 105-110 DEG  C. when the calcium chloride is added.  If desired, the glycerol solution may be evaporated until the tungstic acid is present in a concentration of 0.8% by weight or more before being purified.
Patent GB-795071-A (GB)
Title: Improvements in sheet manipulating machines
IPC: B41F21/10
Filed: 1955-10-19
Abstract: 795,071. Sheet-grippers. BACKHOUSE, H. T. Jan. 18, 1957 [Oct. 19, 1955], No. 29862/55. Classes 100(1) and 100(2) In sheet feeding or delivering apparatus sheets held by one set of mechanical grippers 1 are transferred to another set of grippers 5, and the grippers of one set are bifurcated so that the grippers of the other set are intercalated within them at the time of transfer. As shown, the grippers 1 take the front edge 2 of a sheet registered on a table 3 to the grippers 5 on a rotating drum 6 of a sheet printing, cutting, or creasing machine. The grippers 1, which are carried by an oscillating shaft 7, each comprise a bifurcated fixed jaw 10 secured to a bar 11, and a bifurcated jaw 12 secured to a rocking shaft 13. Each of the grippers 5 is carried on a rock-shaft 15 and is arranged to grip the sheet against the body of the drum 6. The grippers 5 are positioned to enter between the arms of the jaws 10, 12 of the grippers 1 when, as indicated in chain lines, the jaws are at the transfer position.
Patent GB-787209-A (GB)
Title: Improvements in or relating to halo-carboxysilanes and halocarboxysiloxanes
IPC: C07F7/08
Filed: 1955-10-19
Abstract: Organosilicon compounds, suitable as lubricants and as additives for lubricants, have the unit general formula <FORM:0787209/IV (a)/1> wherein Y is chlorine or bromine, a is an integer from 1 to 5 inclusive, n is 1 or 2, m is 0, 1, 2 or 3 and R is a monovalent hydrocarbon or halogenated aryl hydrocarbon radical, e.g. methyl, ethyl, octadecyl, vinyl, allyl, cyclohexenyl, cyclohexyl, phenyl, tolyl, xenyl, benzyl, chlorophenyl, bromo-xenyl and a .a .a -trifluorotolyl.  The compounds may be made (1) by reacting the alkali metal salts of halogenated benzoic acids with halomethylsiloxanes or halomethylsilanes having 1 or 2 halomethyl groups per S, atom, preferably in the presence of solvents, e.g. dimethylformamide, pyridine, ethers, hydrocarbons and acetonitrile, and other reflux temperature of the solvent, (2) or by reacting the above alkali metal salts with siloxanes in which only some of the Si atoms have halomethyl groups attached thereto. The novel siloxanes may be copolymerized in known manner with siloxanes of the unit general formula <FORM:0787209/IV (a)/2> wherein R1 is hydrogen or a monovalent hydrocarbon or halogenated hydrocarbon radical and z is 0, 1, 2 or 3.  Examples describe the preparation of (1) <FORM:0787209/IV (a)/3> and the copolymers <FORM:0787209/IV (a)/4> and <FORM:0787209/IV (a)/5> (wherein Me=methyl and Ph=phenyl; (2) <FORM:0787209/IV (a)/6> and the copolymers corresponding to those of Example (1); (3) a mixture of tribromophenylcarboxymethylheptamethylcyclotetrasiloxanes; (4) a copolymer of pentachlorophenylcarboxymethyl-, phenylmethyl- and vinyldimethylsiloxanes; (5) a copolymer of parachlorophenylcarboxymethyldimethyl-, dimethyl- and chlorophenylmethyl-siloxanes; (6) 4.5-dichlorophenylcarboxymethylcyclohexyloctadecylallylsilane; and (7) <FORM:0787209/IV (a)/7>
Patent GB-204564-A (GB)
Title: Improvements in wheel hubs for perambulators and other vehicles
IPC: B60B27/02
Filed: 1922-11-02
Abstract: 204,564. Williams, S. Nov. 2, 1922. Hubs.-The hubs of perambulator and other vehicle wheels consist of a tubular sleeve 4 mounted on the axle 6, and two separate spoke flanges 1 rotatably mounted upon and directly engaging the sleeve 4 and spaced by an outer sleeve 5. Each spoke flange is in the form of an annular disc stamped from sheet metal, and the spoke holes 2 are also formed by stamping preferably in the same operation. Slots 11 or perforations may be provided in the inner sleeve for retaining lubricant supplied through an oil opening 12 in the outer sleeve.
Patent GB-432397-A (GB)
Title: Improvements in or relating to safety valves
IPC: F16K17/04
Filed: 1934-10-19
Abstract: 432,397. Safety valves. COCKBURNS, Ltd., and MACNICOLL, D., Clydesdale Engineering Works, Cardonald, Renfrewshire. Oct. 19, 1934, No. 29927. Divided out of 430,510. [Class 135] A safety valve installation for steam generators with superheaters comprises a set of piston-operated safety valves 1, 1<a> for saturated steam, a set of safety valves 2, 2<a>, for superheated steam, and pilot valves 104, 104<a> controlling the supply of steam to the superheated steam valves through pipes 105 105<a> and so set that they open before pilot valves 108, 108<a> for the saturated steam valves, connections 107, 107<a> from the saturated-steam pilot valves to the inlets 106, 106<a> to the pistons of the superheated steam valves and double non-return valves 109 being provided so that in the event of the saturated steam valves opening first, due for example to the springs weakening, the superheated steam valves will also open.
Patent GB-1341323-A (GB)
Title: Rare earth transition metal exchanged faujasites and catalysts  prepared therefrom
IPC: B01J20/18
Filed: 1971-06-25
Abstract: 1341323 Metal exchanged faujasite W R GRACE & CO 25 June 1971 [26 June 1970] 29949/71 Heading C1A A synthetic faujasite possesses a silica : alumina molar ratio from 2À5 : 1 to 6À0 : 1, a rare earth ion content from 2 to 15% by weight expressed as RE 2 O 3 ; and a content of transition metal ions from 0À2 to 3% by weight (expressed as M 2 / n O where M is a transition metal and n is the valence of M), the transition metal ions not being wholly chromium. The preferred transition metal is iron or a mixture of iron and chromium. The faujasite may be prepared by exchanging alkali metal faujasite with ions of one or more transition metals (other then solely chromium) and with rare earth metal ions in solution, which solution has a pH of 2-4, from 0À01-0À2 moles/litre transition metal ions, and from 0À1 to 0À4 moles/litre rare earth ions, and calcining the exchanged faujasite at from 600 to 1500‹ F. Salts used in the preparation of exchange solutions may be chlorides, sulphates and nitrates. Subsequent to the calcination step the faujasite product may be further washed or exchanged with ammonium sulphate solution or other ammonium salts until the sodium content of the faujasite is reduced to a level of from 0À05 to 1À0 wt. per cent expressed as Na 2 O. The examples describe the preparation of sieves from an NaY sieve (SiO 2  : Al 2 O 3  = 5À3 : 1) ferrous sulphate or ferric chloride solution, rare earth (normally mixture of lanthanum, cerium, praseodymium, neodymium, samarium and gadolinium) chloride solutions, and ammonium sulphate solutions.
Patent GB-234393-A (GB)
Title: Improvements in or relating to fire extinguishing devices on motor road vehicles
IPC: A62C3/07
Filed: 1924-12-13
Abstract: 234,393. Savage, G. C. Dec. 13, 1924. Luggage-racks.-A combined fire-extinguisher and blanket or rug rail for automobiles comprises a hollow tubular member 1 detachably held on a seat 9 or other part of the vehicle by spring- clip brackets 7, 8. The member 1 has end caps 3, 4 each provided with ridges 5, 6 to engage the spring clips, and is filled with fire-extinguishing material.
Patent GB-280553-A (GB)
Title: Process of producing n-monoalkyl derivatives of the aminophenols
IPC: C07C215/76
Filed: 1927-11-09
Abstract: 280,553. Traube, W., and Hillriegel, E. Nov. 15, 1926, [Convention date]. N-Monoalkylaminophenols are obtained from thiourea compounds of aminophenols (oxyphenylthioureas) by desulphurizing, alkylating the resulting oxyphenylcyanamides, and splitting off the cyanogroup. The desulphurizing may be effected by means of alkali and lead acetate, oxide, or hydroxide; the alkylation can be effected with alkylhalogenides, alkylsulphates, chloralsulphonic acid alkylesters, or arylsulphonic esters, in alcoholic or aqueous alkaline solution, or in the absence of a solvent when using a salt of the oxyarylcyanamide. The products can be isolated as such, or as salts, or as nitroso compounds. According to the examples paminophenol hydrochloride is heated in aqueous solution with potassium thiocyanate and the resulting p-oxyphenylthiourea desulphurized by heating with caustic soda and lead acetate: the p-oxyphenylcyanamide is then methylated with methyl chloride, bromide, or iodide in presence of sodium ethylate in alcohol, or by means of dimethylsulphate and aqueous caustic soda solution; the cyano groups is eliminated by heating with dilute hydrochloric or sulphuric acid, or with alkali or even water alone, and the pmethylaminophenol isolated as such or as the sulphate. The ethyl derivative is also referred to.
Patent GB-748538-A (GB)
Title: Separator for electric accumulators
Inventor: SCHNEIDER FRIEDERICH AUGUST
IPC: H01M2/16
Filed: 1954-10-19
Abstract: 748,538. Batteries. ACCUMULATORENFABRIEK VARTA N.V. Oct. 19, 1954, No. 30080/54. Class 53. [Also in Group VIII] A separator for ' an accumulator consists of a sheet of wood 4, a corrugated and perforated sheet 5 of plastic or hard rubber and a glass mat 6. The glass mat is of less width than the two sheets so that particles of active material deposited on the edges of the mat do not bridge the electrodes 1, 2. The glass mat and sheet 5 may be made in long lengths which are stuck together by heat or adhesive and cut into the required lengths. Fig. 4 shows a method of sticking the mat and sheet together in which they are laid upon one another and passed between pairs of rotating discs 7, 8, the lower ones of which are supplied with adhesive from receptacles 10 and engage in corrugations in the sheet 5. In an alternative method the mat 6 is impregnated with plastic and the discs 7, 8 are heated, the adhesive and receptacles 10 being dispensed with.
Patent GB-1111746-A (GB)
Title: Vertical shaft kiln
IPC: F27B1/00
Filed: 1966-07-05
Abstract: 1,111,746. Shaft kilns. UNION CARBIDE CORPORATION. 5 July, 1966 [10 Sept., 1965], No. 30111/66. Heading F4B. In the lime kiln disclosed in Specification 878,187, each water-cooled burner beam 100 has threaded studs 102 welded to its walls supporting refractory slabs 104 and 106 secured by means of nuts 108. Slabs 104 may be of insulating refractory and slabs 106 of a 40%- 90% MgO or a 70% Al 2 O 3  material. Spaces 110 and bores for the nuts may be filled with settable refractory which may also replace the blocks.
Patent GB-361063-A (GB)
Title: Electric stove for heating and ventilating
IPC: F24H3/00
Filed: 1930-10-09
Abstract: 361,063. Ventilating and heating apparatus. ECKMANN, I., 40, Bassett Gardens, Osterley, Middlesex. Oct. 9, 1930, No. 30200. [Class 137.] In a ventilating heater in which heating elements are arranged in a vertical duct into the bottom of which is drawn internal or external air or a mixture of the two, to be discharged into the room at the upper end of the duct, the heating elements comprise electric resistors 8 under the control of switches 9 and there is provided an air intake valve 10 which, while regulating the relative proportions of internal and external air does not appreciably alter the total volume of air passing the heater. This prevents the overheating of the resistors and the consequent increase in temperature of the warm air discharged to the room. The duct 3 is built into an outer wall 1 of a room 2 and communicates with the room at about floor level at 7 and with the outside atmosphere at 4. Warm air is discharged to the room near the ceiling.
Patent GB-878201-A (GB)
Title: Heat transfer apparatus
Inventor: SORG KARL WILHELM
IPC: F28C1/00
Filed: 1959-09-04
Abstract: 878,201. Treating gases. GESELLSCHAFT FUR LINDE'S EISMASCHINEN A.G. Sept. 4, 1959, No. 30275/59. Class 55 (2). [Also in Group XIII] In water - cooling apparatus comprising a conduit 1, air is blown downwardly by a fan 3 into water sprayed upwardly from jets 9 and is then deflected through 180 degrees to pass in the direction of the arrows 12 between the side walls of the conduit 1 and of the collecting basin 5. The air passes through a wire mesh screen 7 which acts as an impingement separator.
Patent GB-1468800-A (GB)
Title: Reciprocating piston engines
IPC: F16J9/08
Filed: 1974-06-25
Abstract: 1468800 IC engine cylinders DOXFORD HAWTHORN RESEARCH SERVICES Ltd and E P CROWDY 25 June 1974 [27 June 1973]  30458/73 Heading F1B [Also in Division F2] In order to ensure, in a reciprocating piston engine, that pressure differentials are evenly distributed between the rings of a pack of piston rings 4, by-pass grooves 3 in the cylinder wall form controlled gas leakage paths to the interspaces between the rings. In a fuel injection I.C. engine, an annular groove 5 may be provided in the piston head or cylinder wall so that the air, which it contains, rather than combustion gases, is blown along the leakage path.
Patent GB-390764-A (GB)
Title: Improved apparatus for indicating the temperature of the cylinders of internal combustion engines
IPC: G01K1/14
Filed: 1932-10-31
Abstract: 390,764. Indicating temperature of cylinders ; sparking-plugs. RENARD, M. A., Villa Rusticana, Antheor, Via Agay, Var, and BICLET, E., 10, Rue Commines, Paris, both in France. Oct. 31, 1932, No. 30627. Convention date, Dec. 7, 1931. [Classes 7 (ii) and 7 (iv).] A thermometer 5, operated by a liquid or a gas, is mounted in a sparking-plug 1 ; if of the mercury type the thermometer is located in a socket in the central electrode of the plug as shown ; if of the vapour-tension type it may be integral with the electrode and be exposed to the hot gases in the cylinder. Alternatively it may be mounted in the side of the plug and indicate at a distance, e.g. on the dashboard of a motor-car.
Patent GB-1399581-A (GB)
Title: Character display system
IPC: H03K21/08
Filed: 1973-06-27
Abstract: 1399581 Matrix displays and circuits thereof SPERRY RAND CORP 27 June 1973 [7 July 1972] 30633/73 Headings G4H and G5C A driver circuit for a display (e.g. cold cathode negative glow tubes 10) including a plurality of anodes 11 each associated with a group 12 of selectively actuatable cathodes, comprises groups 14 of cathode drivers, each group being coupled to at least one distinct group of cathodes, and anode drivers 13 coupled to the anodes for activating them sequentially in groups a, ...,n of at least two anodes. In the embodiment shown, incoming BCD signals A-D representing a number to be displayed are converted in 17 to 7-segment signals a-g and applied to groups 14<SP>1</SP>, 14<SP>11</SP> which are actuated in turn by switches 15<SP>1</SP>, 15<SP>11</SP> under the control of a timing unit 18, while the two anodes in each tube are actuated simultaneously tube by tube, by their driver 13. Thus the digits of the number are displayed from right to left at a speed which provides the effect of a steady display. Since the anodes in each tube are at the same potential, inter-digit glow is avoided. In an alternative embodiment (Fig. 3, not shown) the incoming digits are fed to odd and even digit latches (28<SP>1</SP>, 28<SP>11</SP>) and respective BCD/7-segment decoders (27<SP>1</SP>, 27<SP>11</SP>), each respective latch and decoder being activated in turn. Decoder 17 and control 18 may form part of a calculator or counter.