Patent GB-272853-A (GB)
Title: Improvements in or relating to weighing scales
IPC: G01G1/28
Filed: 1927-02-15
Abstract: 272,853. Dayton Scale Co., (Assignees of Bryce, J. W.). June 16, 1926, [Convention date]. Loose-weight apparatus; indicating-mechanism. - In a weighing- scale the load is balanced by a power-driven yielding device and by a power-driven weight-changing device, control devices being provided to bring either or both of these balancing devices into operation automatically as required to balance the load. Printed and perforated records of the load may be obtained. Assuming a load to be placed on the scale pan 10, or on alternative platform mechanism, a scale beam 11 extends a spring 18 and closes contacts D, thereby rotating a motor S through a relay circuit so as to draw down a rack 30. If the load is not too great, the rack extends the spring 18 until the beam releases the contacts D and stops the motor through a regenerative brakes circuit when a final adjustment to exact equilibrium (as indicated by a pointer 46) may be made by means of a hand-wheel 35 on the motor shaft. If the electric power fails. the adjustment may be made by a handle 37. When the load is removed, the beam closes contacts C and reverses the operation of the motor. If the load is too great to be balanced by the spring 18, the rack 30 at the limit of its downward movement operates limit contacts V, thus stopping the motor S and starting a second motor R. The motor R drives a cam-shaft 22 and commences to deposit loose weights 19 upon the beam. When the applied loose weights are sufficient to rock the beam from the contact D to the contact C, the motor R is stopped and the motor S is reversed and the rack 30 rises until the contact C is again liberated, after which exact equilibrium is obtained by means of the hand-wheel 35. When the load is removed, the consequent closure of the contacts C starts the motor S and the rack 30 rises to its upper position and operates limit contacts T, thus causing the motor R to remove the capacity weights 19 from the beam. If the load is beyond the total capacity of the machine, contacts F are opened by the weight-applying mechanism so as to stop the motors. A similarly-operated contact E stops the motors if the weighing platform is removed or pressed upward. The current is supplied to the apparatus through draft-rod contacts A which close when a load is applied. When the beam tilts under the influence of the counterbalancing devices the current is maintained through contacts B until the beam rises to equilibrium position. The capacity weights may be hand adjusted by means of a removable crank handle applied to the shaft of the motor R. The weight of the load is indicated by discs 26, 42 corresponding respectively to the loose weights 19 and to the spring 18 and driven by gearing from the motors R, S. The indications are viewed through apertures in a masking plate 45 carried by the beam. When the beam is out of equilibrium the masking plate obscures the indications. Printed and perforated records, apparatus for giving.-The weight-indicating discs 26, 42 are geared to corresponding printing discs 48, 49 and to pin cylinders 58, 59. Below the pin cylinders is a number of punches 55 capable of independent upward movement. According to the setting of the pin cylinder, the upward movement of certain of the punches is obstructed by the pins or by interposed levers, and the selected punches may be caused to perforate a card 61 when this is raised by the depression of a handle 63. The same movement of the handle produces a printed record from the type discs 48, 49 by means of the usual platen mechanism 66. Unless the beam 11 is in equilibrium a notched member 70 connected to the handle 63 fouls the beam if an attempt is made to operate the handle, and consequently the printed and perforated records cannot be obtained.