Patent GB-190710546-A (GB)
Title: Improvements in and relating to Lathes for Marble or the like.
Inventor: PEIRCE JOHN ROYDEN
Filed: 1907-05-06
Granted: 1908-05-06
Abstract: 10,546. Peirce, J. R. May 6. Turning marble &c.-In a lathe for turning and working marble columns &c., the work is held between chucks. Rounding and fluting cutters are moved along the length of the work and adapted to be moved automatically in a transverse direction simultaneously with their longitudinal movement to vary the diameter at different points of the column. In addition to this automatic adjustment, the cutters may be manually adjustable transversely. While the rounding-cutters are in use, the fluting-cutters may be moved beyond the end of the work so as to be out of the way, and vice versa. The rounding and fluting cutters are preferably rapidly-rotating carborundum wheels with their axes respectively parallel and perpendicular to the axis of the column. In the form shown, the work is held between end chucks B, C. Rounding- cutters D, D' and fluting-cutters E, E<1> are carried on carriages on bases J sliding longitudinally on beds H, this movement being effected by screw shafts K engaging nuts in the bases J. Each nut may be detached from the base J when the corresponding carriage is not required to move. The main driving - shaft N operates a cross shaft O which drives the shafts K by worm gears. The shaft N also drives a wheel Q fast on the shaft of the chuck B. Friction clutches operated by pneumatic pressure are provided so that the rotation of the shafts O and wheel Q may be stopped or reversed. The chuck C is longitudinally adjustable. The carborundum wheels are rotated each by a separate motor a on the carriage. Nozzles l supply water to the cutters. Platforms m for the operator are detachably connected to the bases of the carriages F<1>, G', each platform being provided with means for controlling the rotation of the work and cutters and the longitudinal and transverse travel of the carriages. For the transverse movement of the cutters, the base J of each carriage has transverse rails n on which slides an upper base o of the carriage. The carriages F, F<1> are moved transversely by screw shafts q driven by worm gearing from shafts s, s<1>. The shaft s may be driven by a fluid-pressure motor x, and the shaft s' operated by a hand-wheel y. These shafts s, s<1> are synchronized by a shaft t so that both cutters move in unison to or from the work. For the automatic transverse movement of the cutters simultaneously with their longitudinal movement, a thin metal guide z adjusted by hand-screws 2 to the required contour of the column is traversed by guides 26, 27 on a slide 4, Fig. 7, moving longitudinally with the carriage. The slide 4 carries a valve casing 5 moving on a valve stem secured to a rod 7 and normally at a fixed transverse distance from the carriage. The relative movements of the valve casing and stem determine the admission of fluid to the motor x and cause the carriage to follow the transverse movements of the slide 4. To move the carriage without shifting the slide, the valve stem is moved by operating the rod 7 by means of a hand-wheel 11. To move the carriages G, G<1> transversely, a similar slide 4 and valve mechanism controls the admission to an air motor 18 rotating a shaft 17 which moves the stems of valve mechanism, admitting water to one side or the other of cylinders 14 on the carriages G, G'.