Patent GB-473588-A (GB)
Title: An improved method of and apparatus for decorticating the leaves of phormium tenax and like fibres
IPC: D01B1/22
Filed: 1937-03-16
Abstract: 473,588. Decorticating fibrous leaves. MILBURN, R. H., and MILBURN, H. G. March 16, 1937, No. 7668. Convention date, March 23, 1936. [Class 120 (i)] Leaves of phorinium tenax &c. are decorticated by admitting the leaves at regular intervals to a first series of rollers 1, Figs. 1 and 2, crushing the leaves therein with the exception of their butts or leading ends which are admitted to a second series of rollers 2 without treating them in passage therethrough, reversing the direction of travel of the said butt or leading ends and crushing them while returning through the second series of rollers, washing away waste between the rollers of both series and discharging the fibre from between the two series of rollers in either straight or folded form. The lower rollers 3A are mounted in fixed bearings 6, Fig. 4, while the upper rollers 3B are mounted in vertically movable bearings 6A, and are connected by cross-head members 7 to toggle levers 8, 8A, the upper links 9, 9A of which are pivoted at 10 and connected by a tension spring 12 and are operated by cams 14 mounted on shafts 15. The rollers of each pair are geared together by spur wheels 20 and the lower rollers are driven by bevel pinions 16, 17 from side shafts 18, 19. The rollers of the first series 1 are driven continuously forward while the rollers of series 2 are reversible, being driven from the main shaft 28 through one of the clutches 30, 32, 31, 33 and associated gear wheels 34, 35 and 36, or 37. A lateral shaft 38 is provided to drive the cam shafts 15 and to carry the cams 42, Fig. 3, operating the levers 45, 46 by which the clutches are engaged and disengaged. If desired two pairs only of the second series are reversible while two pairs rotate constantly towards the discharge space 27. Water spraying pipes 48 are provided between the rollers. Series 1 comprises a pair of wooden feeding rollers, four pairs of steel crushing rollers, a pair of light rubber-covered drying rollers, and a pair of feeding rollers. The second series comprises a pair of feeding rollers which may be spirally fluted, a pair of drying rollers and two pairs of crushing rollers. In operation, the leaves are placed on the feed conveyer 21, with their butt ends against a shutter 23, which normally contacts with a fixed platform. The shutter is raised by cam action and the leaves fed into the rollers of series 1. The toggles of the first pair of rollers (feed rollers) are depressed when the butt ends have passed therethrough and the leaves fed thereby through the series. The other toggles are operated successively to depress the upper rollers 3B so that the butt end will pass from the first series untreated, the remaining portion of the leaf being crushed and sprayed from the pipes 48. The gripper 23A is held open so that the butt end passes through the second roller series, being supported and fed thereby but not crushed. The cams 42 now operate to disengage the clutch 31, 33 and engage the clutch 30, 32 so that the rollers of series 2 now rotate towards the discharge space 27, the toggles being operated to depress the upper rollers and crush the butt ends. The crushed fibre is fed down the space 27 by the two series of rollers and if of sufficient length is folded on to the conveyer 27A. If desired to deliver long fibre unfolded the butt end is gripped by the member 23A and held while the fibre is straightened by a sweeper bar 54, carried on conveyer chains 52, 52A, the shutter 23A then being lifted to allow the straightened fibre to be carried away on the conveyer 27A.