GB698084A - Improved automatic control means for roller-mills - Google Patents

Abstract

698,084. Roller mills. BUHLER, GEB. April 12, 1950 [April 14, 1949], No. 9025/50. Class 59 [Also in Group XXIX] Control means for roller grinding mills comprises a detector 15, Fig. 1, in the feed hopper, actuating a valve 13a seating on a piston 13 which controls a feed gate 12 at the hopper outlet, a piston 8 controlling a clutch 5 for the drive of a feed roller 4, and pistons 3 controlling the spacing of the roller 1 from the roller 2. Compressed air is supplied through a pipe 20, past a cock 21 to a chamber 17a above a piston valve 17 and also a port 17b controlled by the valve 17. The chamber is connected by a pipe 16 to the space above the piston 13. Thus. when air is supplied and no material is in the hopper, the valve 17 is held up by a spring and the air is exhausted through passages in the piston 13. When material is fed into the hopper, valve 13a is lowered and pressure builds up in the space above piston 13 and in the chamber 17a causing the piston to move down to open the gate 12, and the valve 17 . to move down to connect part 17b with a pipe 19 communicating with the cylinders of pistons 3 and 8. Hence the roller 1 is moved closer to roller 2 and the clutch 5 is engaged. If it is desired to empty the hopper quickly, the cock 21 is rotated to the position shown in Fig. 2, whereby the air supply is connected to pipe 22 to actuate a piston 23 which fully opens the gate 12, and a piston 9 which moves the piston 8 to engage the clutch 5, the roller 1 having moved away from roller 2. Specification 698,085 is referred to.