Patent GB-751597-A (GB)
Title: A machine for tongueing and grooving the ends of elongated strips of material
IPC: B27F1/02
Filed: 1953-10-30
Abstract: 751,597. Tongueing and grooving wood. VIGERS, F. W. Oct. 22, 1954 [Oct. 30, 1953], No. 30051/53. Class 145 Elongated strips, such as wood flooring strips which have preferably first been planed and, along their longitudinal edges, tongued and grooved, are further tongued and grooved on their short edges by presenting them to a first tool Unit to form a tongue (or groove), conveying them at right angles to their length and then along the direction of their length to the neighbourhood of a second tool unit which forms a groove (or tongue) and conveying them at right angles to their length away from the second tool unit. To avoid splintering at the end of the tongue or groove when the tool leaves the strip, the tool units may be arranged so that one tool forms part of the length of the tongue or groove from one longitudinal edge and another tool, beginning at the other longitudinal edge, completes the tongue or groove, passing completely through the zone of operation of the first tool. In the machine shown in Fig. 1, strips from a magazine A are moved by a claw feeding device to a first conveyer which comprises three chains 1, 2, 3 having dogs 8, the sprockets 4, 4<SP>1</SP> for the chain 1 being adjustable along their shafts by a handwheel 12. The chains feed each strip under an adjustable retaining bar 10, and past a tongueing unit which comprises a pair of saws on the same horizontal shaft, ,the larger saw 16 trimming the end of the strip and the smaller saw cutting a shallow groove corresponding to the shoulder of the tongue on the finished face of the strip, and also a pair of cutters 17 on vertical axes for removing the wood to form the tongue. The tongued strip is deposited on supports 18 and then a reciprocating transfer bar 18a reaches over the strip and moves it on to a conveyer belt 19 by which it is moved to a series of driven rollers 20 that move it up to an. end stop 22. Contact with the stop 22 causes the belt 19 to stop, thus preventing piling-up, and also brings into 'operation a reciprocating bar 23 that pushes the strip sideways on to conveyer chains 24, 25, 26 similar to those of the first conveyer. To prevent a succeeding strip from also being moved sideways, a resilient fence or finger may be provided and the roller axes may be slightly inclined to ensure that strips moving on the rollers are always held against this fence. The chains 24, 25, 26 move the strip. past a tool unit 21 having a grooving cutter 28 and then discharge the finished strip. Instead of being fed from a magazine, the strips may pass direct from a planing- tonguing and grooving machine along a belt and roller conveyer 30 and contact a stop situated near the first tool unit and acting similarly to the stop 22, to stop the belt and move the strip on to the first conveyer by means of a push-bar or by means of claws moving up between the rollers, the number of claws operating being determined by manually-settable means. Instead of stops, photo-electric means may be used. Thickness gauges may be provided in conjunction with the belts to stop the feeding of strips if they are not of the correct thickness and safety devices may also be provided to ensure that the conveyers can only be started if the tool motors are running and that the conveyers are stopped if any tool motor stops. A control desk 31 is provided near the beginning of the conveyer feeding strips to the first tool unit and close to the discharge point of finished strips. In the modified machine shown in Fig. 5, the tongues or grooves are formed, first partly from one longitudinal edge and then completely from the other edge by oppositely-rotating pairs of cutters 34, 35 or 40, 41 on a movable cutter slide 36 or 42 reciprocated by a crank drive 37. The cutters operate while the strip is moving with the respective conveyer and the cutter 35 catches up the moving strip and partially forms the tongue or groove from the rear longitudinal edge and on the reverse stroke the slide moves in the opposite direction to the strip so that the oppositely-rotating cutter 34 moves right through the strip from the front longitudinal edge; as the linear speed of the slide on the reverse stroke can be reduced compared, with the forward stroke, the crank 37a may driven by a groove cam of the desired contour. Alternatively, two separate cutters may be employed, the finishing cutter being fixed and the other being moved in an elliptical path by an eccentric so as to move in behind the longitudinal edge and overtake it to partially form the tongue or groove from that edge. In a further alternative form, the strips may be held in a fixed position by spring-biased or automatically-retractable stops 39 while being acted upon by the moving cutters and one or both chain conveyers may be replaced by claw or pusher devices.