Patent GB-471673-A (GB)
Title: Method of and means for positioning lumber in edging machines
IPC: B27B31/06
Filed: 1936-03-03
Abstract: 471,673. Edging lumber. SORENSEN, E. F. March 3, 1936, No. 6459. [Class 145 (ii)] Mechanism for positioning lumber in edging machines in relation to the line or plane of cut, comprising a number of selectors adapted to be brought into contact with the edge of the work piece, members connected with said selectors and adapted to form clear of the work piece an inverted image of the contour registered by the selectors, and a displaceable positioning member, is characterized in that said positioning member is arranged to be displaced to a position determined by the members forming said inverted image, means co-operating with said positioning member and being adapted to adjust the work pieces to a position determined by the new position of the positioning member, said positioning member being arranged to be displaced and pressed against said members forming the inverted image in a direction forming an angle with the direction of motion of the selectors so that the back pressure on the selectors will be wholly or substantially absorbed by the friction between the positioning member and said members forming the inverted image. In the form shown in Figs. 1 and 3 the lower edge of the work piece 20 is engaged by selector fingers 1a on members 1 movable to and from the saw line, and having inclined upper surfaces 1b which form a reduced, inverted image of the contour of the edge of the work, in a vertical plane passing through the ruler 3. The operation of the machine is briefly as follows. The work-piece 20 is inserted laterally under the raised grippers 19 to such an extent that all cavities are beyond the saw line. The shaft 45 rotates continuously and carries cams effecting in sequence the following movements. Firstly, the lever 38 loose on a shaft 42 is moved to the left, and through a link 37 and other connecting mechanism moves a slide 16 parallel to the saw line ; a cam groove in this slide acts on a roller mounted on an arm secured to a shaft 18 to rotate the shaft 18 and so cause the grippers 19 to descend and hold the work. Further rotation of the shaft 45 releases levers 32, 35 keyed to shaft 42 ; the selectors are now moved against the work by springs, this movement causing rotation of the levers 32, 35 ; the lever 32 is connected by a wire 31 with a shaft 27 which is now allowed to rotate under spring action, cams 28 on said shaft now no longer supporting levers 25 engaging projections on verticallymovable shafts 24 secured at each end of the ruler 3 ; springs 56 now act on said levers 25 to depress the shafts 24 so that the rule 3 bears across two of the selectors. Vertical displacement of the ruler parallel to itself determines the adjustment of the work parallel to itself to and from the saw line ; the inclination of the ruler determines the adjustment of the work angularly with respect to the saw line. Each shaft 24 acts on the tail-piece 29a of a cam 29, the cams now being locked automatically. The levers 39 are now released by cams on the shaft 42 and move to the right, their movement being limited by the engagement of stops thereon with the surfaces of the cams 29 which have been adjusted and locked as described above. Each lever 39 is connected by a wire 36 with a slide 15 urged towards the saw line by a spring 62 ; the limited movement of each lever therefore permits a corresponding movement of its slide 15, thereby adjusting the work relatively to the saw line, translationally and /or rotationally as explained above. During or before this adjustment, the levers 32, 35 are forced to the left, thereby retracting the selectors, and causing the cams 28 once more to hold the ruler 3 in its highest position clear of the selectors. The work is now fed towards the edging cutter by a feed chain 21, the grippers moving with the work by virtue of slides 17. When the work is engaged by top-pressure rollers, the grippers release the work. The cams 29 are now unlocked, and the levers 38, 39 forced back to their original positions, thus resetting the whole mechanism in its original position to receive a fresh piece of work. Members 49 on the ruler which engage the selector are adjustable as shown in Fig. 3, to ensure exact contact despite wear or faulty manufacture. An upper row of selectors 2 is provided to deal with the upper edge of the work, these cooperating with a ruler 4 carried at its ends by shafts 24a screwing into the shafts 24 so as to permit of relative adjustment between the rulers to suit working conditions. Numerous modifications are referred to ; in one of these, the ruler always moves parallel to itself and its movement adjusts a fence parallel to itself and to the saw line. In the modification shown in Fig. 10, the movement of the selector fingers 67a rotatably adjusts cams 101, arranged on vertical shafts carrying said fingers, and co-operating with a vertically displaceable ruler 103. In a further modification, Fig. 12, the selector fingers 204 adjust, through a rack and pinion 72, 202, cams 201 co-operating with a ruler 103. Specification 348,663 is referred to.