Lumber, its manufacture and distribution . er which the endlesschain passes. The trough usually is hinged from 8 to 10 feet from thelower end, in order that it may be raised when it is necessary to repaireither the endless chain or the idler. Power for elevating the end ofthe trough is provided by a hand-operated geared windlass which issupported on a frame-work erected over the end of the trough. Thisframework also supports a roof which affords shelter to the man feedingthe jack chain. The upper end of the incline enters the mill on a levelwith, and parallel to, the log deck, so that logs can
Lumber, its manufacture and distribution . er which the endlesschain passes. The trough usually is hinged from 8 to 10 feet from thelower end, in order that it may be raised when it is necessary to repaireither the endless chain or the idler. Power for elevating the end ofthe trough is provided by a hand-operated geared windlass which issupported on a frame-work erected over the end of the trough. Thisframework also supports a roof which affords shelter to the man feedingthe jack chain. The upper end of the incline enters the mill on a levelwith, and parallel to, the log deck, so that logs can be easily rolledor thrown out of the trough and upon the log deck. The grade of the incline is governed by the height of the sawingfloor above the ground level and the distance from the head of the millto the waters edge. As a general rule, the pitch does not exceed from25 to 30 per cent, although occasionally it is as high as 45 per cent. A stop, or bumper, is placed in the trough near the log jack, in ELEVATION OF LOGS INTO THE MILL 31. St a? ft ~3 c3 bC Oh! - T3 c c ?<*i—I 6 32 SAWMILL EQUIPMENT order to throw off the power and stop the chain in case a log is notthrown upon the deck before it reaches the end of the trough. Thepower driving the chain can be thrown on or off by means of a lever,at the head of the deck, which is under the control of the deck man. The dimensions of the trough conform to the size of the logs handled,the width of the base, inside measurement, often being from 12 to 15inches. The sides slope outward at an angle of from 45 to 60°. Astandard type of the log haul-up is shown in Fig. 14. The endless chain may be of the flat-link or the round-link type,the former being made from steel bars from \ to f inch in thickness,while the latter is made from 1- or If-inch steel, each link measuringover-all from 9 to 9j inches. The log dogs, attached to these chains,are of many types and sizes, two common forms being shown in Fig. 15.
Size: 1163px × 2148px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookpublishernewyo, bookyear1922
