Patent GB-546405-A (GB)
Title: Improvements in or relating to apparatus for and method of aligning movable objects, for example machine elements
IPC: B23B39/02
Filed: 1940-04-11
Abstract: 546,405. Optical apparatus. KEARNEY & TRECKER CORPORATION. April 11, 1940, Nos. 6595 and 6596. Convention dates, April 15, 1939, and May 13, 1939. [Class 97 (i)] Apparatus for facilitating the alignment of movable objects such as machine parts comprises in association with each object a combined sighting telescope and collimator (or target), the objects being aligned by directing them so that the two instruments are sighted into (or towards) each other. The combined telescope and collimator has the usual sighting graticule and may also have a target graticule with provision for illuminating it at will, said graticules being so disposed that when looking into either telescope the observer sees only the sighting graticule of the observing telescope and the target graticule of the distant telescope. Instead of the target graticule, an externally mounted target may be provided on each telescope. The invention is illustrated as applied to a boring and milling machine of the double opposed spindle kind as described in Specification 541,995, [Group XXII], comprising a base 21, Fig. 1, carrying a longitudinally adjustable work supporting table 22, and extensions 23, 24 of the base carrying columns 25, 26 on which are vertically adjustable saddles 27, 28 carrying rams 29, 30 which are slidable to and from the table 22 and support rotatable tool-carrying spindles 31, 32 for simultaneous operation on opposite sides of a workpiece mounted on the table 22. The columns 25, 26 are adjustable towards and away from the table 22 by manually operatable screwed shafts 35, 36, and may be clamped in adjusted position. Initial alignment of the spindles 31, 32 may be effected in known manner by applying measuring instruments and gauges, and making the necessary levelling and scraping operations. The alignment may thereafter be verified or re-established by optical means comprising on each saddle a sighting collimator-telescope 44 mounted on a bracket 45 in such a way that after the initial alignment of the spindles 31, 32, the axis of each telescope can be adjusted parallel to its associated tool spindle, and also that the axes of the two telescopes are in alignment with each other. Each collimatortelescope comprises a fixed tube 75, Fig. 7 with an attached level, and provided with interconnected slidable outer and inner tubes 77, 78 carrying the objective 76 and adjustable by rack and pinion mechanism 79, 80 from a knob 83; an eyepiece 84 adjustably mounted in the tube 75 in the usual way; a sighting graticule 85 on which the eyepiece 84 is focused in use ; and a target graticule 91 which is not in focus on the eyepiece when this is focused on the graticule 85, but which, when illuminated by a lamp which is carried by an arm pivoted on the bracket 45 so that it may be swung into position against the eyepiece 84, serves as target for observation by the co-operating telescope on the other column, the objective 76 in this case serving as collimating lens. Each sighting graticule comprises crossed platinum wires 88, Fig. 9, mounted in a ring 86 displaceable or angularly adjustable by means of screws passing through plates 89 and slots 90 formed in the tube 75. Each target graticule is similarly mounted, but each of the cross wires is duplicated, the wires of each pair being spaced by about one thousandth of an inch; or the wires may be replaced by a glass disc etched with several closely separated orthogonally intersecting lines. If, during a working operation lack of alignment of the spindles 31, 32 is indicated by the optical system, it may be corrected, according to its nature as indicated in the system, by adjusting one or other of the saddles 27, 28 on its column, or one or other of the columns 25, 26 on its bed extension, the column being fitted for this purpose in the ways of its bed extension by means of a pair of tapered gibs provided with adjusting screws (Fig. 3, not shown). In a modified form of the optical system, each saddle is fitted with a telescope 104, Fig. 4 having a single graticule for sighting, and an external target in the form of cross-mark on a bracket 106 extending transversely from the telescoce tube ne-r the objective mounting, the axes of the two telescopes being offset by the distance between the axis of either telescope and the centre of the attached target. A magnifying lens may be attached to each target over its cross-marks.