Patent GB-754746-A (GB)
Title: Log barking machine
IPC: B27L1/10
Filed: 1954-04-06
Abstract: 754,746. Removing bark. BRANDENTHALER, A. April 6, 1954 [Oct. 16, 1953], No. 10077/54. Class 145 [Also in Group XXIX] In a log barking machine, the log is pressed by castering hold-down rollers 355 against pairs of toothed feed rollers 29 that can be set at various angles to feed and rotate the log forwards or backwards and the bark is removed by pairs of power-driven toothed cutters 395 and 429, 431 and of wire brushes 497, each cutter or brush being independently mounted on a swinging arm for movement into and out of engagement with the log; the distance apart of the pairs of feed rollers is also adjustable to accommodate logs of different diameters. All the adjustments are controlled by electric and fluid-operated means from a control box 87. Log-feeding means.-Each feed roller 29 has a cleaning fork 33, Fig. 2, engaging in grooves in the roller and is mounted on a plate 27 carried pivotally on a slide 25. The rollers on each side are driven from a shaft 47 through universally-jointed and splined telescopic shafts 31 that allow the rollers to be swiveled from their parallel positions by a link rod 71 connected to the plates 27 and to a slotted member 75 in a parallel linkage connected to a crank disc 95. By means of a hydraulic ram 103. the disc 95 can be rotated one way or the other to pivot the plates 27 so that the rollers feed the log either forwards or backwards. Another hydraulic ram 203 (not shown) connected to one of the slides 25 adjusts the slides.inwards and outwards to accommodate logs of different diameters, the operated slide being connected to the other slides on that side by links 189 and a shaft 193 and to the slides on the other side by a link 185. The slides 25 are counterbalanced by weights 221 on ropes 223. The hold-down rollers 355 are journalled on arms 362, Fig. 3, of plates 360 pivoted on the ends of bell-crank members 353 which are pivoted at 349 on counterbalanced levers 365 and connected to pneumatic rams 363. By means of a link 347, each lever 365 is connected to a slide 25 so that the hold-down rollers are shifted inwards or outwards at the same time as the feed rollers, but, by means of the pneumatic rams 363, the hold-down rollers can be moved out of engagement with the log or into yielding engagement with it. Bark-removing tools.-The first pair of bark-removing cutters 395 are mounted on swinging arms 385, Fig. 17, pivoted at 387 and are each driven by a chain 403 from a motor 401. The second pair of cutters each comprise two cutters 429, 431 carried by forks 424, 426 independently pivoted on the end of a swinging arm 417 but the forks are loosely connected by an equalizing bar 439 so that when one cutter rides on a branch stub the other cutter is thrust inwardly into engagement with the side of the stub. The cutters 429, 431 are rotated by motors 451 and chains 453, 467, the cutter shafts having an eccentric adjustment for tensioning the chains 467. The cutters 395, 429 and 431 preferably have helical teeth arranged to assist the forward feed of the log and they are driven at a higher speed that the feed rollers 29. The wire brushes 497 are mounted on swinging arms 485 Figs. 2 and 27 are driven by motors 505 and chains 501 and consist of short cable sections welded in holes in a plate 511, the central portion of the plate being unprovided with cable sections so that the brush can conform to the shape of a branch stub. The swinging arms for the cutters and the brushes are moved to disengage the tools from the log, or press them into yielding engagement with the log, by pneumatic rams 407, 471 and 521, respectively. Control means.-The hydraulic ram 103 for adjusting the angular setting of the feed rollers 29 is controlled by a solenoidoperated valve 159, Fig. 9, which is in turn controlled by a rotatable control handle 125. When the handle is rotated in one direction, one end of a cam surface 155 on the handle closes one of a pair of switches 145, 147 on a plate 141 and a solenoid operates the valve 159 to move the ram 103 in the required direction. As the rollers are being adjusted. a counterweighted response cable 81 connected to the linkage operating the rollers rotates the switch plate 141 until the end of the cam surface 155 is clear of the operated switch and the switch then opens to allow springs in the solenoids to return the valve 159 to neutral position and hold the rollers in their adjusted position. A scale on the handle 125 indicates the setting. The ram 203 (not shown) controlling the lateral spacing of the feed rollers is operated by a similar hydraulic system but the cam surfaces are mounted on a sliding plate connected to the response cable. The pneumatic rams 363, 407, 471 and 521 for pressing, respectively, the hold-down rollers 355 and the three pairs of barkremoving tools into yielding engagement with the log are controlled by spring- loaded valves such as 567, 569, which are moved from the closed to open position by fluid pressure supplied through a spring-loaded valve 547 that is opened by a cam handle 483a. All the control handles are mounted in the control box 87 and those for the hold-down rollers and tools are arranged so that two adjacent handles can be simultaneously grasped and operated to operate both rollers or a pair of tools simultaneously.