GB543705A - An improvement in or relating to tool feed motions for metal-planing machines - Google Patents

Abstract

543,705. Planing. SWIFT-SUMMERSKILL, Ltd., and CARTER, J. June 1, 1940, No. 9613. [Class 83 (iii)] A tool feed mechanism for a planing-machine comprises a vertical shaft carrying a ratchet wheel which may be adjustably masked to vary the feed and is operated by one or more pawls actuated by a toothed gear meshing with a toothed quadrant oscillated in unison with the work table movement. In Fig. 1 a spring finger a is pivoted to a lever c pivoted at c<SP>1</SP> and connected through a rod d to a pivoted quadrant lever e, Fig. 2, engaging a gear f loose on the vertical feed shaft g and operating a pawl i<SP>1</SP> engaging a ratchet wheel j secured to the shaft g. A shield k may be set by a handle k<SP>1</SP> and graduated disc k<SP>2</SP> to mask a pre-determined part of the ratchet wheel to vary the feed motion. The handle may be provided with a locking device for the disc. As the table completes its return the dog thereon tilts the finger against the spring pressure but at the beginning of the working stroke the lever c is operated to effect the feed before the tool contacts the work. A pivoted cam n is frictionally engaged by a pulley m on the feed shaft to prevent backward movement of the ratchet wheel j due to spring or backlash. In a modification, Fig. 3, a shaft T rotated alternately in opposite directions carries a clutch part t<SP>1</SP> coacting with a spring pressed clutch part t<SP>3</SP> on a shaft t<SP>4</SP> connected by linkage t<SP>7</SP>, t8 to a shaft t<SP>9</SP> bevel geared to a pawl carrier loose on shaft g. At the end of the table return stroke a projection on a friction driven disc tilts a lever v<SP>2</SP> to disengage a pin v<SP>1</SP> from a cam v and allow the spring t<SP>2</SP> to engage the clutch parts until one revolution has been imparted to the shaft t<SP>4</SP> this movement producing the tool feed.