Patent GB-558441-A (GB)
Title: Improvements in or relating to weighing machines
IPC: G01G1/26
Filed: 1942-07-02
Abstract: 558,441. Weighing-apparatus. PARSONS & CO., Ltd., S., and WHEELER, F. C. July 2, 1942 No. 9139. [Class 143] In a recording weighing machine of the kind wherein the major and minor ranges of weight are balanced respectively by a steelyard and a pendulous resistant, the steelyard poise is moved by a handle through a positive system of levers in such a manner that unless the handle and poise weight are in their correct positions to place the complete mechanism in equilibrium no record of weight either visual or recorded can be taken. The load on the platform is transmitted by levers 1, 2 to a notched steelyard 10 fulcru@ed on a knife-edge 9 and carrying pendulous weights 14, 15. The mechanism is enclosed in a casing to prevent tampering. The steelyard poise 12 is traversed by a slotted bar 26 mounted upon a parallel motion linkage 23, 23x and operated by an external handle 21, Fig. 8, on a shaft 22. A roller 13 on the poise drops into the notches in the steelyard to position the poise out of contact with the slotted bar 26 at each setting. The higher ranges of weight (balanced by the poise 12) are indicated on the upper surface of a segment 42 rocked by a pin 45 moving with the parallel motion linkage 23, 23x. The lower ranges of weight (balanced by the pendulous weights 14, 15) are indicated on the upper surface of a segment 41 actuated by segmental cams 32 pivoted on the steelyard, flexible bands 34, 36 and a drum 37 t igidly connected to the indicating segment. The indications on the segments are viewed through a lens, and (provided the steelyard is in equilibrium) a lamp is lit to enable the weight indications to be read. To ensure that the poise-adjusting handle 21, Fig. 8, cannot be left between the notches of its co-operating bar 28 with consequent inaccurate adjustment of the poise, the handle, is spring-loaded to bias it into a notch-engaging position, and is in addition provided with electric contacts, the closure of which is necessary before an indication or record can be obtained. Printed records, apparatus for giving.-The type numerals are carried on the under sides of the indicating segments 41, 42, the printing being effected on a card (inserted through a slot 67) by means of a solenoid 85 supplied through a plug 47 and through a tilting mercury switch 49 which is rendered operative by the act of unlocking the steelyard. When a ticket is inserted through the ticket slot, it displaces an electric switch and, provided the steelyard is in correct equilibrium, energizes a relay 57x which, after a slight delay closes the circuit of the printing solenoid 85. Top and bottom cores of the solenoid then squeeze the ticket against the type. The contacts on the handle 21 are also incorporated in the lamp and relay circuit to ensure that the handle is correctly positioned in a notch before the circuit can be completed. If the steelyard is not in equilibrium one or other of two rods 58, 58x opens its co-operating switch 61 or 62 to interrupt the actuating circuit and prevent both a ticket being printed and the illumination of the indicating lamp. When the switch 61 or 62 is opened, a contact 73 or 75 at the other end of the switch is closed thereby illuminating one or other of two red arrows to indicate in which direction the operator must move the handle 21 in order to adjust the poise and bring the steelyard into equilibrium so as to permit a record and an indication of the weight to be obtained.