Patent GB-191510223-A (GB)
Title: Improvements in or in connection with Hydro-extractors and like Machines.
Inventor: HALEY HENRY ASKE
IPC: B04B7/06
Filed: 1915-07-14
Granted: 1915-11-04
Abstract: 10,223. Haley, H. A. July 14. Guards, controlling.-The cover of a centrifugalmachine casing is locked during running and unlocked on stopping by a device comprising a shaft j having a screw groove k by which a co-operating sleeve p is moved axially. The upward movement of the sleeve on starting closes and locks the cover, and the downward movement on stopping opens it. The sleeve may be automatically released for the downward movement by a governor device, as shown in Figs. 1 and 3, or semi-automatically by a hand-wheel as shown in Fig. 12. In the former arrangement, the grooved shaft is housed in a casing h secured to the casing a, Fig. 5, and is driven by a belt pulley m from the machine spindle. The sleeve p has a roll r engaging the groove, and a loose sleeve s which is prevented from rotating by a tongue u running in a groove w in the casing h. A rod v is connected to the tongue u and also to the overbalanced lever f of the hinged casing cover d, Fig. 5. On starting the machine, the sleeve p rises and closes the cover. A flange 3, Fig. 3, on the sleeve has a projection 4 bearing against a bar x, which has shoulders 2 and is mounted to slide away from the shaft j, as shown at y. This bar prevents rotation of the sleeve p until it has reached the top of its stroke when the flange 3 engages the upper shoulder 2 and pushes the bar out of the way. The bar is held in either position by an adjustable spring-pressed friction pad 5. At the top of its stroke, the roll r passes behind a catch-finger 9, and the sleeve then rotates with the shaft j until the catch is released. This release is effected by a governor device in the pulley m, which does not operate until the speed has dropped right down. The catch-finger 9 is mounted on a rod 8, which passes through the shaft j and has a trigger 11 adapted to be actuated by a projection 18 on the inward movement of a centrifugal weight 15. Two spring-pressed centrifugal weights 15, 16 are mounted on bars 13 in the pulley m. While running, the weight 15 is held out by a catch 26 on a spring 25. This catch is not released until the machine has nearly stopped, when the weight 16 has moved inward sufficiently to engage the end 27 of the spring 25. The inward movement of the weight 15 is then controlled by a dash-pot piston 20, the pulley being filled with oil. The construction of the dash-pot may be varied. In a modification, a clutch is interposed between the driving- pulley m and the shaft j. When the sleeve p reaches the top of its stroke, the clutch is automatically disengaged. In a further modification, Fig. 12, the centrifugal device for releasing the sleeve is dispensed with, but the hand-operated release provided cannot be operated until the speed of the shaft j has fallen low. The catch-finger 9 is here carried by a sliding bar 38, the upper end of which has a projection 42 engaging a cam 43 on a collar 44. This collar normally rotates with the shaft j, but it can be rotated relatively to the shaft j through a small angle by a hand-wheel 45 when the speed is sufficiently low for the operator to rotate the hand-wheel fast enough to engage the clutch 46.