Brake drum turning machine
AssigneeF. Jos. Lamb Company
InventorRobert P. Jones
Life of this patent
Estimating the term…
Abstract
A machine for machining brake drums wherein the cutting tool is cyclically retracted axially on its rotating spindle at a rate corresponding to the axial feed rate of the spindle and then quickly advanced on the spindle to the same extent so that the tool marks on the machined surface comprise a series of circular, rather than helical, grooves with relatively short, axially inclined grooves connecting the successive circular grooves.
Claims19
A machine for machining an axially extending surface of revolution on a workpiece so that the machining marks will be essentially circular rather than helical comprising, a support, a rotatable spindle movable axially on said support, means for rotating said spindle, means for supporting a workpiece so that the surface to be machined is coaxial with the spindle, a cutting tool mounted to rotate with said spindle and shiftable axially on the spindle, means for advancing said spindle axially in the feed direction at a predetermined rate during each machining cycle of the machine, means operative during said machining cycle for cyclically retracting the tool axially on the spindle in the opposite direction and at substantially the same rate as the spindle feed during a time period corresponding to at least one revolution of the spindle;
- and means operative following each cycle of operation of said cyclically operative means for shifting the tool on the spindle in the feed direction to the same extent during a time period corresponding to substantially less than one revolution of the spindle.
A machine for machining an axially extending surface of revolution on a workpiece so that the machining marks will be essentially circular rather than helical comprising a support, a rotatable spindle movable axially on said support, means for rotating said spindle at a predetermined speed, means for supporting a workpiece so that the surface to be machined is coaxial with the spindle, a cutting tool mounted to rotate with said spindle and shiftable axially of the spindle, means for advancing said spindle axially in the feed direction at a predetermined rate during each machining cycle of the machine, cam means journalled on said spindle for rotation about the axis of the spindle, means for rotating said cam means at a predetermined speed different from the speed of rotation of the spindle, said cam means having a circumferentially extending cam track thereon, a cam follower operatively connecting said tool and cam track for reciprocating the tool axially on the spindle in response to relative rotation between the spindle and cam means, said cam track having a first ramp thereon inclined to a radial plane at a predetermined angle throughout its arcuate extent such that, when the cam means and spindle are rotated relative to each other, the cam traverses said ramp, the arcuate extent and the inclination of said ramp being such that when the cam means and spindle are rotated at their predetermined speeds the cam follower traverses said ramp and retracts the tool on the spindle at substantially the same rate as the spindle is advanced in the feed direction for a period corresponding to at least one revolution of the spindle, said cam track having a second ramp thereon circumferentially contiguous to said first ramp, the second ramp having a substantially shorter arcuate extent than the first ramp, the starting point of the first ramp and the ending point of the second ramp lying in the same radial plane, the arcuate extent of the second ramp being such that when the cam means and spindle are rotated at their respective predetermined speeds the cam follower traverses the second ramp for a period of time corresponding to only a small fraction of one revolution of the spindle.
Dependencies are inferred from the claim text.