GB392670A - Improvements in or relating to doctors for calenders and the like - Google Patents

Abstract

392,670. Doctors for calenders and the like. BROUGH, A. and WATF0RD ENGINEERING WORKS, Ltd., Lower High Street, Watford, Hertfordshire. Feb. 3, 1932, No. 3259. [Class 96.] A doctor for calender rolls &c. comprises a blade 16, Fig. 1, movable towards or from the roll 11 and tilting about an axis parallel to that of the roll when thrust against the roll, to bear on it at an angle controlled by a blade &c. 25. The blades 16, 25 may be laminated and clamped between angle-bars 26, 27 and held with a washer 36 of leather &c. by bolts 28 and rectangular nuts 34 against a bar 33 pivoted by bolts 31 to rods 18 held in the carrier bar 14 by nuts 19, 20 and ridged washers 21, 22, the arrangement allowing thermal expansion of the bar 33 and blade 16 &c. in the clamp. The bar 14 may be tubular and steam may be supplied thereto to avoid buckling the blade 16 by unequal frictional heating. A guard may also be held in the clamp. The blades may be slued relatively to the roll by adjustment of the nuts 19, 20 on the rods 18, the blade edges being made concave or sufficiently flexible to fit the roll. The carrier bar 14 is eccentrically pivoted in fixed supports and may also be loaded by a spring or bv a weight along a radial arm, or by a worm connected with a hand-wheel and engaging wormteeth on the bar 14, allowing variation of the eccentricity of the bar 14 whilst working. Alternatively the blades 16, 25 may be integral and clamped by a bar 46, Fig. 7, having keyhole slots in which bosses are locked by endwise movement of the bar which has screwthreaded ends carrying nuts and slotted washers. The wear on the two blades may be made the same by use of different pressure on each or by their being at different angles to the roll or one may be of spring steel and the other of mild steel or they may be reversed, one having a shoe or mask. The doctor may be made into a water-doctor by closing, and connecting pipes to its ends.