Abstract:
A programming system for use in machine tools wherein a slide is reciprocable by a hydraulic motor which receives and discharges hydraulic fluid by way of a regulating valve on the slide. The valve has a spool which is reciprocable between two operative positions and a neutral position and has a radially extending follower which can be arrested by the projections of an indexible drum mounted adjacent to the path of the slide. The movements of the spool from its neutral position to a selected operative position (in which the motor receives fluid for moving the slide forwardly or rearwardly) are initiated by a control plunger secured to the follower and reciprocable in cylinder chambers of the housing in response to admission of pressurized control fluid by a four-way pilot valve. The follower moves against a first projection during forward movement of the slide to thereby return the spool from one operative position to neutral position, and against another projection during rearward movement of the slide to thereby return the spool from the other operative position to the neutral position. The nominal diameter of the plunger is a small fraction of the diameter of the spool.
Abstract:
A tracking valve which can be mounted on a tool-supporting carriage in a machine tool and whose main valve member is a spool which is movable axially in a valve body to thereby start a hydraulic motor for the carriage so that the motor can move the carriage relative to a template while simultaneously moving one or more tools relative to a workpiece. The spool has a relatively large surface at one end, a relatively small surface at the other end, and an axial bore for a pilot valve member which is mechanically connected with a follower for the template and is movable by the follower to thereby regulate the pressure of a fluid acting against the larger surface of the spool. The smaller surface of the spool is subjected to a constant fluid pressure and such constant pressure can be assisted by the bias of a spring. The spool has lands which control the flow of fluid to and from the motor by way of ports machined into the housing of the tracking valve and the pilot valve member has two fluid flow regulating surfaces which flank an annular control chamber communicating with a compartment provided in the housing adjacent to the larger surface of the spool. When the pilot valve member is moved axially, either by the follower or by a resetting linkage which can be moved by an indexible cam drum, the fluid flow regulating surfaces change the pressure of fluid in the compartment and thus effect an axial movement of the spool relative to the housing.
Abstract:
A template has a contour which is to be copied, and a tracing device is movable relative to the template for tracing the contour thereof. The tracing device has a contact member which contacts the template and moves along the contour of the same, and this contact member has two or more contact faces of different diameters which can individually engage the template contour.