GB121206A - Improvements in and connected with Grinding Machines. - Google Patents

Abstract

121,206. Lyon, F. W., and Ross, A. Dec. 22, 1917. Roller-and-ring mills. In mills having the rollers mounted on pivoted carriers, onethird to one-quarter of the circumference of the ring is formed as a discharge outlet. Rotating vanes may be provided for throwing the material on to the ring and for closing the discharge outlet. In the mill shown, the ring 2 is formed with a discharge grid 5, a feed-mouth 3, and an air inlet 6. The roliers 16 are carried at the ends by arms 17 having bolts 18 mounted in slots 19 formed in plates 15 which are secured to the driving-shaft 10. The rollers may be plain or grooved. The ring consists of blocks of stone or metal which are supported by the side frames 1 of the mill and are bound by hoops 9. The side frames are of skeleton form and are covered by removable plates. The bearings of the driving-shaft are trunnioned in forks which are free to rise or fall in brackets on the side frames. The bearings. may be connected to a shutter or other device for controlling the feed of material to the mill, the arrangement being such that the lifting of the bearings caused by accumulation of material at the bottom of the ring causes a reduction of the feed. The plates 15 carry backwardly inclined vanes 22 having the tips arranged near the ring 2, the vanes serving to throw the material on to the ring and in front of the rollers. The grid 5 opens into a chamber 25, Fig. 3, which is provided with baffles 27 and communicates through a pipe 26 with a suction fan. The vanes periodically occupy the position shown in Fig. 3, the suction through the grid 5 being thereby reduced, and over-size particles being allowed to fall back into the mill.