Patent GB-722490-A (GB)
Title: Improvements in or relating to a felt hardening machine
IPC: D04H17/12
Filed: 1952-11-17
Abstract: 722,490. Felt. AMERICAN FELT CO. Nov. 17, 1952, No. 29034/52. Class 42 (2). [Also in Group XXXII] A felt hardening machine comprises a plurality of upper rollers 20 and driven lower rollers 21 rotatably mounted on a frame 22, an apron B for carrying the material F to be felted between the upper and lower rollers, fluid pressure means for raising the lower rollers towards the upper rollers, means for reciprocating the upper rollers axially including yokes 50, 51 connecting reciprocatory driving means to pairs of alternate upper rollers, and vibration damping means for each pair of upper rollers, the yokes and damping means for adjacent rollers being disposed on opposite sides of the machine. Instead of using a single apron B, material F may pass through the machine between two aprons. As shown, Fig. 12, two superposed batts from rolls 89, 90 are hardened simultaneously and wound up on to rolls 95, 93 respectively; a separator cloth S from a roll 91 is fed between the two batts and wound up on to a roll 94. Before passing between rollers 20, 21, material F passes through a steam bath 92. Lower rollers 21 are driven through chains 36 from a delivery roller 39 and are supported, as described in Specification 722,500, in vertically-slidable bearings each connected to the piston of a pneumatic or hydraulic cylinder 35 for controlling the pressure between the upper and lower rollers. Upper rollers 20 are slidably mounted in fixed bearing housings 26, Fig. 1, the ends of the roller shafts being supported in thrust bearings in housings 29 carried by the yokes 50, 51. Yoke 50 is, as described in Specification 722,499, reciprocated by means of a rotary shaft 48 and eccentric crank 49, shaft 48 being driven by a motor 43 through an hydraulic coupling 45; yoke 51 is reciprocated 180 degrees out of phase with yoke 50 by a crank 57 driven from hydraulic coupling 45 through a shaft 52, or yoke 51 may be driven independently by a second motor. Each yoke 50 or 51 is connected by compression springs 72, Fig. 9, to a compensating weight 61 mounted on the machine frame by resilient supports 62; the weight of weight 61 and the number and stiffness of springs 72 are chosen with respect to the weight and speed of reciprocation of the pair of rollers 20 to constitute a balanced compensating system which will be 180 degrees out of phase with the rollers and so reduce transmission of vibration to the machine frame. Magnetic brakes 59 hasten deceleration when motor 43 is shut off, so as to prevent the compensating system spending a prolonged time at the resonant period of the springs; if acceleration is slow when motor 43 is started, weights 61 are held until rollers 20 have reached full speed when they are released. The hardening rollers 20, 21 may be arranged, as shown, in two units each of four rollers 20 and five rollers 21. To provide a good grip on material F or apron B, rollers 20, 21 have circumferential sharp-edged grooves cut in their surfaces. More than two batts may be simultaneously hardened, separator cloths being used between each pair of adjacent batts.