GB303811A - Improvements in or relating to veneers - Google Patents

Abstract

303,811. Ovenhausen, F. Jan. 9, 1929. [A Specification was laid open to inspection under Sect. 91 of the Acts, Jan. 10, 1929]. Cutting veneers.-In a veneer lathe, a cutter-head 3 carries one or more knives having cutting edges inclined to the axis of the work x so as to remove a sheet 4 from the conicallyshaped end of the work, the work being fed axially to the cutter-head. As shown in Fig. 1, the work x is gripped by radial dogs 2a mounted slidably on three rods 1 secured at their ends to a plate 1<a> and a bevel gear 1<b>, the latter being rotated by the gearing shown from a motor 7<a>. The work is fed downwards to the stationary cutter-head 3 and passes a stationary knife 5 which cuts off the bark and trims the work to a cvlindrical form. The table 6 on which the veneer 4 is deposited is rotated by the gearing 7 at a speed different from that of the work and appropriate to the speed of cutting, or alternatively the table may be rotated by hand. The knives 8<a>, 8<b>, Fig. 3, may have straight cutting edges so as to form a plain cone on the end of the work or may be curved, an example of a curved form for the end of the work being shown in Fig. 5. One knife may remove the parts of the work marked 9<a>. 9<b>, in Fig. 5 so that the other knife may remove a veneer 10 of uniform thick. ness in spite of the curved surface. The cutterhead may have an additional knife for removing the apex of the work so that the veneer will overlap at the centre when it is deposited on the table, or alternatively the work may be drilled centrally as a preliminary operation. The inclination of the knives 8<a>, 8<b> is arranged so that the length of a generatrix of the cone is substantially an integral multiple of the radius of the base of the cone, the multiple preferably selected being three or more. The multiple may be arranged at slightly less than an integral number in order to allow for the shrinkage of the veneer which takes place after cutting. The work may be arranged in any position other than vertical, and the veneer may be subjected to pressure after cutting to convert it into a flat form. The work may be supported during cutting at one or more points round the apex and the support may be funnel shaped or may consist of a number of strips or rollers. The margin of the veneer may be ornamented by operating on a workpiece which has an angular, oval or other non- circular periphery and ornamentations may be produced in the veneer itself by using a non- homogeneous work-piece. An example of this is given in which the work consists of two semicircular portions 11, Fig. 10<a>, of walnut with inserted rods 11<a> of the material such as ebony, the resulting venee@ being shown in Fig. 10, when a knife having an inclination of 6: 1 is used. Two sheets having a radial grain as shown in Fig. 10 may form the outer layers of a plywood sheet, the intermediate layer having a circular grain and being formed from a workpiece composed of annularly coiled long veneers. The radial joint of the intermediate layer is cut by hand in a zig-zag or similar line so as to break joint with the outer layers.