GB489058A - Improvements in or relating to weighing apparatus - Google Patents

Abstract

489,058. Vibration - dampers. BEST, C., and MOLINS MACHINE CO., Ltd. April 15, 1937, No. 10736. Addition to 431,478. [Class 108 (iii)] [Also in Groups XXXV and XI] A liquid, e.g. oil, in which moves a damping vane on the pointer of a weighing-apparatus, as in the parent Specification, is heated to a temperature in excess of the highest ambient temperature to which the apparatus may be subjected and maintained substantially at that temperature so that the viscosity of the liquid remains constant and the weigh beam always comes to rest in minimum time. The vane 10 is immersed in oil in a chamber 11, which is in communication with oil in a chamber 13 comprising a screw plunger 15 which enables the oil to be maintained in contact with a level indicator 17. These chambers are surrounded by an oil bath containing an electric resistance heater 18 wound on insulating pillars 19 between supporting elements 20, 21 held together by nuts or screwed bolts 22. The plate 20 supports a thermostat comprising a bimetallic element 25 carrying a contact member 26 co-operating with an adjustable contact member 27. The resistance is connected to terminals 23, 24 and the thermostat to terminals 31, 32. The terminals 31, 32 may be connected to a battery through the coil of a relay operating a switch in the supply circuit connected to the terminals 23, 24. Fig. 6 shows a modification whereby lamps 39, 43 may indicate a failure of the apparatus. The relay coil 33 when opening the circuit of the heating resistance 18 closes an alternative circuit through an equivalent resistance 42 whereby the lamp 39 which is in series with both resistances supervises this circuit. A failure of the relay resulting in excessive temperature is indicated by means of auxiliary contacts 45, 46 in series with the lamp 43 which are closed by excessive flexure of the bimetallic element 25. Specification 425,700, [Group XVIII], is referred to.