GB849314A - Improvements in or relating to weighing machines - Google Patents

Abstract

849,314. Photo-electric control of weighing apparatus. BERRY & WARMINGTON Ltd. Jan. 22,1959 [Oct. 25, 1957], No. 33317/57. Class 40(3). [Also in Group XVIII] Photo-electric cells 15 and associated lamps 20 adjustably positioned with the aid of pointers 16 at desired readings around the scale in a dialtype weighing machine co-operate with a drum 18 mounted on the pointer spindle 17 and having a peripheral aperture coincident with the pointer 19 to furnish electrical impulses to control the opening and closing of feed gates or valves supplying substances to the weighing pan or hopper of the machine. Connections to the cells and lamps are made by cables 23 which extend via plugs 23a to sockets 21b carried by a centrally positioned housing 21 supported on a cable conduit 22. The cells and lamps are supported by brackets 14 from a circular channel member 13, the brackets being so constructed (see Fig. 5, not shown) as to permit the Sells to be offset relatively to the pointers to compensate for the amount of material, in transit at the moment of controlling the feed gates or valves. Additional photo-electric cells 15a may precede the main cells 15 and serve to reduce the amount of material being fed to the machine just prior to the cut-off point. A further photo-electric cell 30 is associated with the zero position on the scale to prevent initiation of operations until the machine has been adjusted correctly. In a modification, Fig. 6 (not shown), lamps 20 individual to each photo-electric cell are replaced by a single lamp supported at the centre of drum 18 by housing 21. Reference is also made without giving details, to a construction in which the photo-electric cells, instead of being adjustably mounted on a circular member 13, are carried by radial arms adjustable by knurled knobs grouped coaxially at the centre of the dial.