Patent GB-778616-A (GB)
Title: Improvements in or relating to three-roll mills
Inventor: BEACH ERIC PROCTOR
IPC: B02C4/36
Filed: 1955-08-22
Abstract: 778,616. Roller mills. VICKERS-ARMSTRONGS (ENGINEEERS), Ltd. July 9, 1956 [Aug. 22; 1955], No. 24174/55. Class 59 In a 3-roller mill of the kind in which material to be ground is passed between a first roller and a second roller and then between the second roller and a third roller, the axes of the three rollers being parallel, the second roller is carried by adjusting mechanism arranged for moving the second roller towards or away from the plane that includes the axes of the first and third rollers whereby the clearances or pressures between the rollers are adjusted simultaneously, the adjusting mechanism also being arranged for moving the second roller towards and away from each of the other rollers individually, so that the clearance between the first and second rollers can be increased (or the pressure decreased). whilst at the same time the clearance between the second and third rollers is decreased (or the pressure increased) and vice versa. As shown, the second roller 4 is carried at each end thereof by a bearing 9 the housing 10 of which is pivoted by a pin 12 to one arm 13 of a bellcrank lever 14 which is pivotally secured at 15 to an adjacent side frame 1 or 2, the free bifurcated end of the other arm 16 of the bellcrank lever rotatably carrying a pin 17 which has a tapped hole 18 therethrough engaged by a bolt 19 the free end of which threadedly engages a pin 20 rotatably mounted in an upright lever 21 the lower end of which is pivotally secured at 22 to the adjacent side frame 1 or 2. The upper slotted end of the lever 21 has mounted therein a sliding block 24 having a hole therein engaged by an eccentric pin 25 on one end of a cross shaft 26.- The shaft 26 has keyed thereto a downwardly-extending lever 28 the free end of which is pivotally secured to one end of an adjusting link 29 the other end of which is pivotally secured to the free end of a lever 30 keyed to a shaft 31 mounted in the side frame 1 and provided with a handle 32 associated with pawl- and-ratchet mechanism 33. Each bearing housing 10 also has a downwardly-extending arm 34 provided with a slot 35 in which. is located a sliding block 36 having a hole through which passes an eccentric pin. 37 on a short shaft 38 having keyed thereon a gear segment 40 co-operating with a worm 41 on a shaft 42 provided with a hand wheel 44. Movement of the handle 32 downwardly causes the free ends 13 of the bellcrank levers 14 to be moved upwardly through the lever and link arrangements to withdraw the roller 4 from the rollers 3 and 5, the roller 4 being guided during such movement by the slots 35 in the arms 34. When the handle 32 is moved upwardly, the roller 4 is moved downwardly until it contacts or almost contacts the rollers 3 and 5. The pressures or clearances between the rollers 3, 4 and between the rollers 4, 5 are adjusted by operation of the hand wheels 44. When the two hand wheels are turned in one direction, the gear segments 40 cause the eccentric pins 37 to swing in an arc towards the roller 3, the roller 4 swinging about the axis of the pins 12. Hence the clearance between the rollers 3, 4 is decreased (or the pressure increased) whilst the clearance between the rollers 4, 5 is increased (or the pressure decreased). When the hand wheels are turned in the opposite direction, the reverse effect is obtained. The mechanical linkages may be replaced by other means, e.g. hydraulic mechanism.