GB1290360A - - Google Patents

Abstract

1290360 Gauging CINCINNATI MILLING MACHINE CO 18 Dec 1969 [23 Jan 1969] 61791/69 Headings B3B and B3T A machine tool comprises a base on which are mounted a tool 14 and a workhead 18; feed means producing relative movement therebetween along a feed path; a generator emitting a beam of constant-frequency light; means causing the beam to pass in a plurality of beam paths in side-by-side relationship all lying in a plane extending at a right-angle to the said feed path and at slight angles to one another, each beam path having a discrete width and the plurality of beam paths defining an area substantially larger than the area subtended by the beam itself; and a photo-cell receiver on which the light impinges and acting, when the tool enters the plane and interrupts the beam, to establish a reference point in the said feed path. The work-head includes an arm 22 having a light generator 22 and an arm 23 having a light receiver 24 containing a photo-cell. The plane is produced from a single beam by means of either a pair of angularly adjustable mirrors (Fig. 2, not shown) between which a beam closely zig-zags before passing to the receiver, or by oscillating a beam by means of an oscillating mirror (Fig. 3, not shown) in which case the receiver includes a spherical or parabolic mirror for focusing the beam on to the photo-cell. The beam may be a constant fixed-frequency laser. The machine tool may have a rotary tool spindle carrying single point tools, multi-point milling tools, fly-cutters or trepanning tools. The tool 14 may be a turning or boring tool for rotary work. To ensure that the light sheet is initially pierced by the tool profile and not by dirt or swarf on the tool, a tool cleaning device comprising a brush and an air blast is provided, e.g. in connection with a tool changing arrangement. An alternative machine tool arrangement (Figs. 5 and 6, not shown) comprises a longitudinally movable tool spindle mounted on a vertically movable spindle head which moves on a column that is horizontally movable along a bed. A tool storage magazine and tool changing arrangement is provided. Movable with the spindle head are two brackets which hold a light beam source and a receiver respectively, the light beam defining a plane of light through which the axis of the tool spindle passes.