Patent GB-1023548-A (GB)
Title: Production of scarfed or single v joints
Inventor: CARRUTHERS JOSEPH FORSYTH SCOT
IPC: B27M3/00
Filed: 1962-10-18
Abstract: 1,023,548. Seaming non-metallic sheet material. NATIONAL RESEARCH CORPORATION. Nov. 14, 1963 [Oct. 18, 1962], No. 39518/62. Heading B5K. In a method of making scarfed or single V joints in pieces of wood, after cutting the scarfed or V surfaces and coating one or both with adhesive, the two pieces are aligned with reference to the two edges on the same side of the two pieces, the joint is then precisely and firmly wedged endwise, and finally pressure is applied to the join through the outer surface of the overlapped pieces. As shown, apparatus for effecting the joining comprises a press section PS and infeed and outfeed sections IS and OS, respectively. The section IS comprises freely rotatable rollers 12 mounted on a table frame 11 and aligning means comprising on one side swinging fingers on the ends of levers 13 linked by a pneumatic cylinder 14 and stops 15 adjustable in position to limit the outward movement of the linked ends of the levers 13 and on the other side swinging fingers on the ends of levers 17 linked by a cylinder 18. The cylinder 14 is operated at a higher pressure or is of larger diameter than the cylinder 18 so that the levers 13 are first brought to a definite position and then the levers press the board 19 against the levers 13. The cylinders 14, 18 may be double-acting or provided with return springs. An upper pad 21 carried on the piston-rods of cylinders 23 and a lower pad 22 carried by the cylinders 23 themselves form a clamp for holding the board after alignment. The table 11 is pressed forward during joining and retracted by a cylinder 25 and is guided for raising and lowering by stubs 26 having rollers 27 running in guides 28 each comprising a forward section at a level corresponding with the leading end of a board resting on the bottom platen 29 of the section PS connected by a sloping section to a rearward section corresponding to the raised level, Fig. 1. The section PS comprises a fixed platen 29 and a movable platen 31 raised and lowered by cylinders 32, 33 which are arranged so that when the platen is lowered the outfeed end comes down first so that a pad 34, adjustable vertically by a nut 37, engages the work and then the platen 31 pivots about this pad to the horizontal position, Fig. 3 (not shown). After the trailing scarfed end of one board has been clamped, the leading scarfed end of the next board is wedged in the gap between the platen 29 and the scarfed surface of the first board. Pressure is applied to the platen 31 by cylinders 38, 39. The surfaces of the platens may be provided with low voltage heating elements 41. Alternatively, radio frequency heating may be provided by electrodes. The section OS comprises freely rotatable rollers 42 and aligning means having fingers 43 and similar to that of the section IS. The joined boards can be fed by a vertically movable driven roller 45 and a fixed position roller 44. The roller 45 is journalled in a frame 46 moved in vertical guides by a cylinder 47 through a lever 48 and is driven through chains by a reversible two-speed motor 49. In use, the scarfed or V-surfaces of the boards are previously cut and coated with glue which may be a synthetic resin. The first board is positioned on the platen 29 and the motor 49 driven at slow speed in either direction to bring the scarf or V in the required position. The platen 31 is lowered and the next board run on to the section IS. The board is aligned by the cylinders 14, 18 and is then clamped between the pads 21, 22 and fed forward to mate with the first board with the table 11 in the lower position. The cylinders 38, 39 are actuated until the joint is set. The platen 31 is raised and the next cycle is initiated by outfeeding the jointed board and infeeding the next board. The operations of the apparatus may be controlled separately from a console, the completion of each movement being indicated by a signal controlled by a micro-switch actuated by a moving part in the final position. A timer to return the parts to their initial positions after setting of the adhesive and photoelectric cells to observe the trailing edge of the jointed board may be provided.