GB164503A - Improvements in apparatus for testing and recording the cutting efficiency of saw blades - Google Patents

Abstract

164,503. Herbert, E. A., and Fletcher, C. March 11, 1920. Recording particular operations.-A sawing machine is provided with a recorder for showing the number of strokes, or the time, taken to perform each cut, and also the number of cuts completed. The chief use of the apparatus is to record the performance.of saws in cutting standard pieces, and thereby to test their efficiency. As applied, for recording the number of strokes and cuts, to the hack-sawing machine described in Specification 17372/13 [Class 145 (ii), Wood, Working], a cam c rotated by the repeat shaft of the machine controls a lever o pivoted at o<3> and bearing by means of a spring plunger n upon one end of an endwise movable spindle j<1>. The saw reciprocating crank-shaft of the machine is provided with a cam which at each rotation reciprocates a pawl f<1> engaging a ratchet wheel h and so through reducing gearing rotates a spur wheel j fixed on the spindle j<1>. A friction disc k and a pinion l are loosely mounted on this spindle, and when the lever o is in its opertive position the pinion l is driven by the wheel j and raises a rack m carrying a pencil p bearing against a chart drum q. When a cut has been completed, the lever o is shifted and so releases the pinion l and allows the rack and pencil to fall to initial position. The drum q meanwhile has been rotated one step by a pawl r' engaging a ratchet wheel r and carried by a spring controlled arm s pivoted on the lever o. The fall of the rack m is cushioned and adjustably limited by a resilient pad g and a co-operating screwed pin m<1> adjustable on the rack. The pencil may be actuated by a clock instead of by the machine. and in the case of non-automatic machines the rotations of the drum and the release of the pencil may be effected by hand.