FIG. 244.—AUTOMATIC BAND RIP SAW.
The Band Saw is an endless belt of steel having teeth formed along one edge and traveling continuously around an upper and lower pulley, with its toothed edge presented to the timber to be cut, as seen in [Fig. 244], which represents a form of band saw made by the J. A. Fay & Egan Company, of Cincinnati. A form of band saw is found as early as 1808, in British patent No. 3,105, to Newberry. On March 25, 1834, a French patent was granted for a band saw to Etiennot, No. 3,397. The first United States patent for a band saw was granted to B. Barker, January 6, 1836, but it remained for the last quarter of the Nineteenth Century to give the band saw its prominence in woodworking machines. That it did not find general application at an earlier period was due to the difficulty experienced in securely and evenly joining the ends of the band. For many years the only moderately successful band saws were made in France, but expert mechanical skill has so mastered the problem that in recent years the band saw has gone to the very front in wood-sawing machinery. To-day it is in service in sizes from a delicate filament, used for scroll sawing and not larger than a baby’s ribbon, to an enormous steel belt 50 feet in peripheral measurement, and 12 inches wide, traveling over pulleys 8 feet in diameter, making 500 revolutions per minute, and tearing its way through logs much too large for any circular saw, at the rate of nearly two miles a minute. A modern form of such a saw is seen in [Fig. 245]. Prescott’s patents, Nos. 368,731 and 369,881, of 1887; 416,012, of 1889, and 472,586 and 478,817, of 1892, represent some of the important developments in the band saw.
FIG. 245.—MODERN BAND SAW FOR LARGE TIMBER.
When the band saw is applied to cutting logs the backward movement of the carriage would, if there were any slivers on the cut face of the log, be liable to force those slivers against the smooth edge of the band saw, and distort and possibly break it. To obviate this the saw carriage is provided with a lateral adjustment on the back movement called an “off-set,” so that the log returns for a new cut out of contact with the saw. Examples of such off-setting are found in patents to Gowen, No. 383,460, May 29, 1888, and No. 401,945, April 23, 1889, and Hinkley, No. 368,669, August 23, 1887. A modern form of the band saw, however, has teeth on both its edges, which requires no off-setting mechanism, but cuts in both directions. An example of this, known as the telescopic band mill, is made by the Edward P. Allis Company, of Milwaukee.
A saw which planes, as well as severs, is shown in patents to Douglass, Nos. 431,510, July 1, 1890, and 542,630, July 16, 1895. Steam power mechanism for operating the knees is shown in patent to Wilkin, No. 317,256, May 5, 1885. Means for quarter sawing in both directions of log travel are shown in patent to Gray, No. 550,825, December 3, 1895. Means for operating log turners and log loaders appear in patents to Hill, No. 496,938, May 9, 1893; No. 466,682, January 5, 1892; No. 526,624, September 25, 1894, and Kelly, No. 497,098, May 9, 1893. A self cooling circular saw is found in patent to Jenks, No. 193,004, July 10, 1877; shingle sawing machines in patents to O’Connor, No. 358,474, March 1, 1887, and No. 292,347, January 22, 1884, and Perkins, No. 380,346, April 3, 1888; and means for severing veneer spirally and dividing it into completed staves, are shown in patent to Hayne, No. 509,534, November 28, 1893.
Planing Machines.—While the saw plays the initial part of shaping the rough logs into lumber, it is to the planing machine that the refinements of woodworking are due. Its rapidly revolving cutter head reduces the uneven thickness of the lumber to an exact gauge, and simultaneously imparts the fine smooth surface. The planing machine is organized in various shapes for different uses. When the cutters are straight and arranged horizontally, it is a simple planer. When the cutters are short and arranged to work on the edge of the board they are known as edgers; when the edges are cut into tongues and grooves it is called a matching machine; and when the cutters have a curved ornamental contour it is known as a molding machine, and is used for cutting the ornamental contour for house trimmings and various ornamental uses.