Lumber, its manufacture and distribution . ith four saws and is designedto make two slabs, two boards, and a cant at one operation. Thesaws are 40 inches in diameter and will cut logs 17 inches or less in diam-eter. The rated capacity of the machine is from 1800 to 2000 logsper day. Breaking-down Mill. A special type of circular sawing rig having three circular sawscutting in a vertical plane and one circular saw cutting in a horizontalplane, as diagrammatically shownin Fig. 61a, was devised to handlethe large-sized timber on the Paci-fic Coast, especially redwood. Thesaws A and B were run onl
Lumber, its manufacture and distribution . ith four saws and is designedto make two slabs, two boards, and a cant at one operation. Thesaws are 40 inches in diameter and will cut logs 17 inches or less in diam-eter. The rated capacity of the machine is from 1800 to 2000 logsper day. Breaking-down Mill. A special type of circular sawing rig having three circular sawscutting in a vertical plane and one circular saw cutting in a horizontalplane, as diagrammatically shownin Fig. 61a, was devised to handlethe large-sized timber on the Paci-fic Coast, especially redwood. Thesaws A and B were run only whenthe size of the logs required theiruse. The saws C and D were ad-justed to cut in the same line,while saw B cut in a plane at rightangles to saws C and D. Saw Acut in the same plane as C and Dbut 7 inches further in the log. Thecutting planes of the various sawsare shown in Fig. 616. The break-ing down of the log continued in FlG; G1-Saw Arrangement and the Cut-ting Planes of a Circular Breaking-downSaw. a. The Diagrammatic Arrange-. ment of the Saws A, B,C, and Planes of the Saws. this manner until it was reducedto a size which could be workedby the saws C and D. The effectiveness of this equip-ment varied with the size of the log, a very slow feed speed beingrequired when all four saws were used, otherwise the saws would tendto lead into the log. The average capacity of a mill of thischaracter sawing redwood was 45,000 board feet daily, although whenlogs over 7 feet in diameter were handled the cut was less. Thisstyle of breaking-down equipment has been displaced by large bandmills which are more efficient. Band Mills. These are built both in single-cutting and double-cutting types,that is, they may cut only on the forward run of the carriage—single-cutting, or the saws may be toothed on both edges and cut both on1 See Fig. 60, for the general character of the equipment. 82 SAWMILL EQUIPMENT the forward and rear travel of the carriage—double-cutting. Thefi
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Keywords: ., bookcentury1900, bookdecade1920, bookpublishernewyo, bookyear1922
