GB951856A - Improved log-handling device - Google Patents

Abstract

951,856. Sawing. ETABLISSEMENTS GUILLIET. April 25, 1962 [May 5, 1961], No. 15853/62. Heading B5L. [Also in Division B8] A device for rotating a log about its own axis and bringing into a sawing plane a plane of the log passing through the heart thereof comprises a cradle formed by two cables 6, Figs. 1 and 3, suspended between pulleys 7, 8 and intended to receive the log in the horizontal position, a system 13 for running the cables relatively to the pulleys so as to cause the log to roll about its own axis, and supports 26 of adjustable height adapted to come into contact with the bottom surface of the log to lift the latter above the cradle formed by the cables to bring the log into the sawing plane. The pulleys 7, 8 are mounted on supports 9 in a pit 1 having an access stairway 2 and the log is received on the slack lengths 12 of the cable. The system for running the cables over the pulleys to rotate the log consists of hydraulic jacks 13 having rods 16 provided with clamps 17 for securing to the cables, the length of stroke k of the jacks being greater than a quarter of the maximum perimeter of the logs. When the log is in its predetermined angular position, the supports 26, which are in the form of T-shaped frames, are raised by hydraulic jacks 32 into abutment with the bottom surface of the log. The upper arms of the frames have guides 28 for pairs of dogs 31 which can be brought together to grip the log by hydraulic jacks. Further extension of the jacks 32 raises the log from the cables to position a plane of the log in the plane X of a chain or band saw device which is movable along rails at the side of the pit 1. The raising and rotating of the log may be semi-automatically controlled by devices situated at each end of the pit 1 and movable along rails 42, Figs. 5 and 6, parallel to the longitudinal axis of the pit. Each device consists of a frame 44 which is mounted on rollers 45 movable along guides 46 transversely to the rails 46 and on which are pivotally mounted arms 48 of a parallelogram 47, the arms being connected by pivots 50, 52 to a link 51; the parallelogram has balancing springs 53. A guide pin 54 is mounted on the pivot 52 and an arm 55 having a second guide pin 56 on its outer end is pivotally mounted on the pivot. In operation, with the log in its lower position, the guide pins 54 are driven into the end faces of the log at a predetermined position from the heart K 1 of the log. The guide pins 56 are also driven into the end faces with the arms 55 in the horizontal position. When the supports 26 are raised by the jacks 32 to lift the log the arms 48 rotate about the pivots 49 in the direction of the arrow f until cams 63 engage limit switches 61 which actuate relays 71 to disconnect the supply to the jacks 32, the heart of the log then being in the position K2 in the sawing plane XX. After sawing has been effected, the two halves of the log are clamped together and the supports 26 lowered. The dogs 31 are withdrawn from the log and the jacks 13 actuated to displace the cables and rotate the log. When the log has moved through 90 degrees, the arms 55 are in horizontal positions and fingers 64 actuate limit switches 62 to disconnect the supply to the jacks 13. The log is then raised as before to be cut into quarters. In other embodiments the jacks may be of electric type, the trolley supporting parallelogram may move on rails in the bottom or on the walls of the pit 1, and the jack 13 operating the dogs may be replaced by motor- and-gear units driving the pulleys 7.