Patent GB-190114095-A (GB)
Title: A Chiselling (Chasing or Carving) Machine (or Lathe)
Inventor: JOHNSON JAMES YATE
Filed: 1901-07-10
Granted: 1902-07-10
Abstract: 14,095. Johnson, J. Y., [Avril, P. V., and Soc. Marinier, Navoit, & Jeanson]. July 10. Lathes; planing and shaping. - Relates to a machine for copying a flat pattern on to a cylindrical blank. The blank e, Fig. 1, is mounted between centres as in an ordinary turning-lathe. The tool is mounted at 71 on the saddle d which is traversed by a screw i. A longitudinal cut is thus made on the stationary blank, the depth of the cut being regulated by a crank controlled by the tracing - point. The pattern m, Fig. 2, is mounted on a table which is traversed by a screw X. After each traverse the blank e is rotated through a small angle and the pattern is advanced through a short distance, before the next cut is made in the opposite direction. The necessary reversals of the mechanism are made at the end of each stroke by electromagnetic apparatus. For example, when the saddle d travelling in the direction of the arrow 105 reaches the end of its traverse, the lever 115 makes contact with the stop 122 and closes the circuit of the electromagnet 1, which reverses the transmission between screw i and the shaft f. The lever 115 at the same time closes the circuit of the electromagnet 128, which attracts the pulley 131 and thereby reverses the rotation of the screw i. The screws h, X are thus rotated through a small angle and impart the required advance to the blank e and the pattern m. At the end of the return stroke of the saddle d, similar operations take place. When it is desired to produce the pattern several times in succession on the blank, a cam 49, divided into the required number of sections, is fixed on the end of the spindle f. Every time the spring contact 50 crosses from a recess to a ridge, an electric circuit is closed and energizes a magnet 35, which reverses the rotation of the screw. X by acting upon the pawls of ratchet-gear. The reversal of the screw X reverses the movement of the pattern, which is thus reproduced once more on the blank. When it is desired to reproduce a small pattern several times in the direction of the length of the blank, a double ratchet-gear reversible by an electromagnet 52 is mounted on the end of the screw i. When the tracer reaches the end of the stationary pattern, the circuit of the magnet 52 is closed and the screw q through the gearing 63 or 64 is set in motion. This traverses the pattern at, say, twice the speed of the slide, and repeats the pattern backwards on the blank. The pattern may be distorted on the blank by changing the velocity ratio of the gearing. The tracer which operates on the pattern does not directly impart the radial movement to the tool-holder 71, but acts through an electromechanical relay, i.e., the movements up and down of the tracer energize one or the other of the magnets 92 or 93, and thus connect one or other of the two oppositely-rotating wheels 94 or 95 to a crank which actuates the sliding tool-holder on the saddle d. When the tracer encounters a steep part of the pattern which it cannot pass over, a circuit is closed which energizes the magnet 137, Fig. 1, and thus disengages the screw i while at the same time one of the magnets 92, 93 is energized so as to lift the tracer over the ridge. Instead of a relief pattern, a pattern drawn in insulating varnish may be used. The electromechanical relay is then actuated by variations in the electrical resistance at the tracer point. The pattern, instead of being flat, may be cylindrical and mounted between centres. Cylinders for rippling, ribbing, mohairing, or watering textile fabrics, leather, &c. may be made by this machine. The type of ratchet gearing for transmitting a single angular advance at the beginning of the revolution of a continuously-rotating arm is shown at Fig. 6. This gearing is used for giving the feed to the pattern and the blank in the carving-machine. Suppose that the arm 15 commences to rotate in the direction of the arrow 32, the tappet 25 catches on the projection 19 and carries round the disc 17 until the projection comes opposite a fixed inclined plane 29, which lifts the tappet 25 clear of the projection in this and every following revolution. When the rotation of the arm 15 is reversed, the tappet 26 acts on a projection 19<111> in a similar way, setting the projection 19 back to its original position. The ratchet-gear 22, 24 ensures rotation of the shaft h<1> in one direction only. In another form a double pawl is used, so that rotation can be imparted in either direction.