Patent GB-648887-A (GB)
Title: A float-balance for measuring weights or forces
IPC: G01G5/02
Filed: 1947-03-27
Abstract: 648,887. Weighing apparatus. OUAYDA, S. March 27, 1947, Nos. 8371, 8372 and 8373. Convention dates, March 28, 1946, Aug. 27, 1346 and March 8, 1947. [Class 143] In a float balance the main body of the float is completely immersed in the liquid and the float is counterbalanced by the variable immersion of a number of thin rods connecting the main body with the weigh pan and the whole assembly is stabilized by a counterweight and/or the load located outside the liquid. A tank 9,Fig. 1, shaped as shown contains the main float body 1 which is connected with a pan supporting rod 7 by means of rods 4 and a disc 6, the variable immersion of said rods serving to counterbalance the load. The disc 6 engages the lid 12 when the balance is unloaded so acting as a limit stop and when it is desired to transport the balance the rod 7 is loaded to such an extent that the disc 6 seals the top of the sleeve 14. Weight indications may be marked on the rod 7, or alternatively, the rod may carry an indicator which co-operates with a fixed scale. In a modification (not shown) the sleeve 14 is dispensed with and the rods are connected with the weigh pan again located beneath the tank by a frame extending around the outside of the tank. In a further modification. Fig. 5, four tanks 21 each contain a float 20 which is connected with a pan by a cruciform member 22. The modification shown in Fig. 6 has a streamlined float to reduce friction, a hollow disc 6 the top and bottom members 5, 5a of which co-operate with a flange on the top of sleeve 14 to prevent liquid spillage on sudden loading or unloading of the pan, and an indicating means comprising a pointer 16 co-operating with a finely graduated scale on a transparent dome 18, and an indicator on the rod 7 co-operating with a large unit indicating scale on a glass portion 20 of the sleeve 14. The tank may also be of streamlined shape to reduce the amount of liquid required in which case it is surrounded by a water jacket which serves to inhibit temperature changes throughout the weighing operation. The pan used in the above modifications may be of the type shown in Fig: 8 with which first the datum position of the indicator is noted with the pan supporting weights 26 only on the lower shelf 22, and then, after the load has been placed on the other shelf 21, the weight of weights 26 removed to return the indicator to its datum position represents the weight of the load. The pan 31 may be located above the balance as shown in Figs. 11 and 13 in which case the counterweight 28 serves to stabilize the apparatus. Loose weight apparatus.-In the modifications shown in Figs 11 and 13 the weight of the load is determined automatically by the number of weight bones 36 or weight discs 42 which are no longer supported by the float when it supports the load, and a scale registering the immersion of the float serves to indicate the weight of the load directly. The accuracy of this balance is limited by the number of weight bones or discs that can be used, but by semi-automatic operation comprising placing loose weights on the pan in addition to the load, a higher degree of accuracy can be obtained.