GB743885A - Improved de-barking machine - Google Patents

Abstract

743,885. Removing bark. GORDON & CO. Ltd. J. R. Sept. 2, 1954 [Sept. 9. 1953: July 3, 1954], Nos. 24920/53 and 19561/54. Class 145 A machine for stripping bark from logs comprises a pair of rollers 15 16 rotating in the same direction and each formed with a helical projection 15a. 16a so as to convey the logs through the machine and the log is pressed against the debarking rollers by a pressure roller 23 rotated in the same direction as the debarking rollers about an angularly-adjustable axis and at a slower speed so as to control the rotation and axial feed of the log. At the entry end de-barking rollers 15, 16, taper both in root and external d'ameter and at the exit end, have solid cylindrical portions 15c, 16c that exert a polishing and braking action on the de-barked log. Breaker bars 15d, 16d, which may have sharpened edges, may be provided to remove knots and the start of the helical projections on one roller is displaced angularly relative to the start on the other roller. The pressure roller 23 may have rubber ends 23a and a central toothed metal portion 23h and it is adjustable about a substantially vertical axis on a pivoted arm 10a urged downwards by gravity supplemented by the loading of springs 29 which are adjustable by a lever 30 and notched plate 31. The pressure roller and arm 10a are raised by a cable 32 connected to a hand lever 33 and to a pedal 35 and an adjustable stop 36 for the pedal limits the downward movement of the arm. If the cable should break, the downward movement is stopped by a rod 53 engaging the bottom of a tube 54 and in order to lock the arm during transport, the rod and tube may be provided with holes for a co-operating pin. The machine is mounted on a trailer and driven by a power unit 52, such as a petrol or diesel engine, the drive to the pressure roller including a reduction gear box 38 and a universally-coupled shaft carried in bearings in the arm 10a. A ducted impeller for removing bark fragments is mounted on a countershaft below the de-barking rollers. A hinged guide trough 58, at least partly composed of rubber prevents irregular'y shaped logs from breaking loose and a chain 59 arranged between stanchions 60 supports long logs. A roof 64 and canvas side and end covers may be provided. The first Provisional Specification describes also a stationary machine with separate motors for driving-the de-barking and pressure rollers, transverse adjustment of the de-barking rollers, one or more pressure rollers rotating in the same direction as the de-barking rollers and normally retracted from the log by a spring, pressing of the pressure roller against the log by hand, foot, fluidoperated or automatic mechanism, grooved metal rollers behind the pressure rollers for assisting the log feed, tapered threaded entry ends on the pressure rollers and rubber rings at each end of the de-barking rollers.