Patent GB-476049-A (GB)
Title: Improvements in apparatus for delivering measured quantities of granular and like materials
IPC: G01F11/24
Filed: 1936-05-29
Abstract: 476,049. Measuring granular and like materials. BROWN, A. G. May 29, 1936, Nos. 15238 and 26082. [Class 69 (i)] Apparatus for measuring the quantity delivered of granular and like material, of the type comprising a compartmented drum 14 rotatable on a horizontal axis by the weight of material filled into the compartments, is provided with fluid-pressure means to control the rotation to ensure that each compartment is filled as it passes the filling opening. In the apparatus shown, the material is delivered through the mouth 12 of a hopper 10 into four compartments formed between radial vanes 16 in the rotatable drum, the mouth 12 being offset as shown in relation to the vertical plane through the axis of the drum to ensure the rotation of the drum due to the load in one compartment. The rotation of the drum is controlled by a roller 32 carried by the piston rod 36 of an hydraulic cylinder 54 and engaging a substantially square cam 30 secured to the shaft of the drum. The cylinder is connected to a supply tank 62 by a suction pipe 82 containing a non-return valve 84, and by exhaust pipes 60, 64 both controlled by a regulating valve 80. The weight of material in a full compartment causes the drum to rotate, the cam 30 forcing back the piston until the roller 32 passes over one of the high spots on the cam, the speed of rotation being controlled by the setting of the valve 80, past which liquid is expelled from the cylinder to the tank 62. The drum then revolves while the full compartment moves towards the discharge position and the next compartment moves towards the feed opening 12, the piston being returned by springs (not shown) acting on a cross-head 44. During substantially the latter half of this movement the piston is again forced inwardly and slows up the movement of the drum to an extent determined by the valve - 80. The exhaust pipe 64 can be closed either by a valve 68 operated by a hand lever 90, or by a valve 70 connected by a rod 74 to a spring-pressed diaphragm 72 in the hopper or feeding-shoot, this latter valve closing when the diaphragm 72 rises owing to lack of material, the weight of which normally depresses it. The piston towards the end of its inward-stroke closes the exhaust port 58 leading to the pipe 60, so that closure of either of the valves 68, 70 prevents further exhaust from the cylinder and brings the apparatus to rest in the position shown. To prevent slow rotation of the drum in these circumstances, owing to leakage past the piston, a pawl 86 on the starting handle engages .one of a number of stops 88 on the drum. The fluid system may be under pressure, in which case the springs for moving the piston outwardly are omitted. A counter 102 may be provided. To avoid jamming of material between the edges of the vanes 16 and the edge of the filling aperture, their outer edges may be formed by thick rubber flaps 96 supported by tongues 98 on the vanes, so that the flaps may bend backwardly from the direction of rotation. Ribs 100 may be arranged across the opening 12 in register with the tongues 98 in order that the latter may not trap material in a similar way. Alternatively, the flaps 96 may be broader so that they are permanently bent backwards, the tongues 98 and ribs 100 being dispensed with.