Patent GB-450154-A (GB)
Abstract: 450,154. Calculating-apparatus. AMY, G. W., 181, Market Street, Millgate, Shawforth, Lancashire, and SOWERBUTTS, J., Lark Hill, Glen Avenue, Colwyn Bay. Jan. 8, 1935, No. 579. [Class 106 (i)] Adding and subtracting apparatus tabular appliances. - A machine for performing addition or subtraction comprises a number of coaxial rotary numeral bearing elements on a common rotary member and normally independent thereof, transfer mechanism between the elements, a normally disengaged clutch between each element and the rotary member, means for selectively engaging any one of the clutches, and means for rotating the rotary member to a predetermined position in accordance with the value to be entered. In the form shown, the machine comprises a hollow base 1, Fig. 2, a casing 2, and a cover plate 3 with ball bearings for a central tubular member 5. The tube 5, Figs. 2 and 7, is provided with a number of fixed collars 6 and a number of slidable collars 7 forming clutch elements. Supported on four posts 10 are a number of fixed carrier plates 11 each with a large central aperture in which is rotatably mounted the hub 14 of a circular disc 15 provided with a flange 17 supported on a ball race on the corresponding carrier plate 11. Each disc is formed with a peripheral edge 16 bearing numbers representing the denominational values in the decimal, monetary or other notation for which the apparatus is designed. Pins 20 on the hubs 14 serve as the co-operating clutch elements with teeth 8 on the slidable collars 7. The tube 5 is adapted to receive motion from the armature 27 of an induction motor, the pole magnets 28 of which are secured to the underside of the cover plate 3. The selection of the clutch elements to couple the appropriate numeral disc 15 to the tube 5 is effected under the control of keys 48 constituted by spring-pressed contact studs that co-operate with contact strips 49 in the plate 3. The plate 3 has an annular flange 46 on which is mounted the plate 47 that supports the keys 48 ; this flange 46 carries a rack 52 which through a planet pinion 53 gears with a circular rack 51 on a flange 50 secured to the tube 5. The pinion 53 is carried on a member 54 rotatably mounted on the tube 5 and having a projecting arm 56 forming a pointer 57 that moves over a scale on the plate 47. On the cover plate is mounted a housing 58 containing a coiled spring 59 and a slidable rotatable spider 60. The spring is contained in a flanged casing 64 with slots in the flange into any one of which the outer end of the spring may be inserted and held. The inner end of the spring is connected to a bush 65 rotatable on the tube 5. The casing 64 and bush 65 each have a radial projection 66 which as the spring unwinds come against the opposite sides of a fixed stop 67. A radial arm 68 engaging a pin 68a on the spider extends between the projections 66 so that on rotation of the spider the spring may be coiled from the outside or inside to cause it to act in opposite directions for addition and subtraction respectively. Each denominational row of keys has associated with it a pair of solenoids 69 with armatures connected by a yoke 70 to an annular member 71 surrounding the tube 5 and connected by wires or pins 72, Fig. 7, to the sliding collars 7. The armatures have extensions 73 with spaced contact rings 74, 75 adapted to co-operate with complemental rings 74, 75. The rings 74 are in circuit with solenoids 85 having armatures 86 which when pulled down engage depressions 84 in a plate 83 attached to a circular disc 79 and the base of the central column 5. In operation, when one of the studs is depressed a circuit to the corresponding solenoids 69 is completed and the appropriate disc is clutched to the column 5. At the same time the contacts 74 are closed to energize the solenoids 85, the armatures 86 of which serve as ratchet pawls in association with the depressions 84 in the plate 83. Thereafter the contacts 75 close to energize the motor circuit which rotates the column against the action of spring 59 ; the parts continue to rotate until the arm 56 engages the depressed stud 48. When this stud is released the parts, with the exception of the adjusted numeral disc 15, return to normal position. If it is desired to subtract an item, the spider 60 is raised free of the arm 68 and is then rotated through a revolution and lowered again to place the pin 68a on the other side of the arm 68. This operation may operate a reversing switch in the motor circuit or a separate reversing switch may be provided. The plate 79 carries a conical flange 81 bearing rows of tabular information representing functional values of the setting imparted to the discs such as multiples, roots, powers, equivalents in foreign currencies, &c., which are visible through numbered apertures 82, Fig. 3, in the base 1. To record the sum of the amounts added or subtracted, the corresponding studs 48 are depressed successively and the machine operated as above described. The movements imparted'to the disc 79 are successively transmitted to a type bar 90 by means of a roller thereon engaging the edge of a cylindrical cam 89 mounted on the disc 79. The bar 90 carries a complete set of type for each denomination and the type selected for impression is operated by depressing the appropriate denominational key 100 which closes the circuit of a solenoid 99 to operate the impression hammer 98. To prevent a second operation before the parts have resumed their normal position, a pair of electrical safety devices are mounted on the plate 3. Each device as shown in Figs. 8 and 9 comprises a boss 101 of insulating material carrying four contacts 102, a disc 103 with corresponding contacts on an axle 104, an arm 106 on the axle and a spring which tends to keep the contacts apart. The arm 106 lies in the path of the axle of the planet pinion 53 so that at the zero position the arm is moved to bring the contacts into alignment. A light spring 105 bears on the motor magnet 28 and maintains the safety device until the motor circuit is broken at the contacts 75. In a mechanical form of apparatus the solenoids 69 and members 70, 71 would be replaced by yoked levers operated by the keys to clutch in the appropriate disc and the arm 56 would be rotated by hand differentially in accordance with the value. Transfer mechanism.-Pivoted on each plate 11 is a D-shaped plate 29, Figs. 4 and 5, with oppositely directed pawls 32 with upstanding ears 37 engaging a spring 33. Depending from the plate 29 is a housing 41 with a double-ended plunger 42 lying in the path of a projecting pin 44, Fig. 5a, on the next disc 15 of lower value. At the end of a revolution of this disc the pin 44 engages the plunger 42 and rocks the plate 29 to effect a carry-over by the engagement of one or other of the pawls 32 with the pins 20 on the disc. The rocking of the plate 29 is limited by fixed stops 43 and the pin 44 is mounted on toggle arms 44<a> controlled by a spring 44b which give to allow the pin 44 to pass the plunger. Zeroizing-mechanism.-By depressing a knob 23 a rod 22 is lowered and fingers 24 thereon are moved into the path of pins 21 on the discs so that when the knob is rotated the discs are returned to zero position.