Patent GB-499751-A (GB)
Title: Improvements in or relating to copying machines
IPC: B23Q17/24
Filed: 1937-07-24
Abstract: 499,751. Copying machines; engraving. KAPELLA, Ltd., and TAYLOR, M. H. July 24, 1937, No. 20489. Addition to 481,591. [Class 60] [Also in Groups XVI and XXII] The copying-machine described in the parent Specification is modified so that relative movement between the tool and work supports is maintained equal to that between the image and the microscope, whereby the reproduction ratio of the machine is determined wholly in accordance with the optical magnification ratio. The machine comprises a base A having movable transversely thereon, on bearing balls A<2>, a slide B, on which is movable, in a direction perpendicular to that of the movement of the slide B, on bearing balls B<3>, a carrier C. The slide B is urged by springs D<3> so that a lug thereon engages the end of a screwed rod D<1>, engaging a nut D<2> and movable by a head D ; the nut D<2> is split and may be clamped to a pin D' carried by the base A. The carrier C is movable, similarly to the slide B, by a head E and a nut &c. E<2>, the carrier being pressed up to the rod E<1> by a spring E<3>. In bearings F<2> on the carriage is mounted a shaft F<1> carrying a work-table F, and near the other end of the carriage is a bearing G<3> supporting, on a tubular member G<2>, a frame H<1> in which is adjustably mounted, by a screw H<2> a copy table H; an image of the copy is projected, by a lens G<4> carried by the member G<2>, on to a screen G. The work-table F and the copy-table H &c. may be rotated synchronously, through equal gears F<3>, F<4> and an idler gear F<5>, by a disengageable worm L<2>, which may drive a worm gear L<3> secured to the work-table. Two microscopes J, J<1> are mounted with their optical axes O, O<1> vertical, on a bracket J<2> on the base A, the distance between the axes being equal to that between the axis R of the work-table and the axis R<1> of the copy-table ; the plane of the axes O, O<1> is termed the primary plane. The tool, shown as a grinding-wheel K, is mounted on a horizontal shaft K<1> parallel to the primary plane on a vertically reciprocable plunger movable in a slide K<4> adjustable transversely on a way K<5>, which is angularly adjustable about a horizontal axis on a plate K<7>; the wheel thus may be adjusted to bring its operative edge into the primary plane, and to compensate for wear. In operation, the wheel K is set by the aid of the microscope J and the carriage C is moved, by means of the heads D, E, to cause the image to traverse beneath the microscope J<1>, the tables F, H being rotated as necessary. The machine may be used to generate straight lines, by setting the work-table through the required angle and movement of the carriage C, and may be used also to generate circular arcs. For this purpose, the part G<1> is removed and a part carrying a slideway M<8> is substituted on the member G<2>, the slideway carrying adjustably a pin M<5> which is engaged in an arm on a slide M<2> movable on a fixed way M<3> by a screw M<1> and hand wheel M. The pin M<5> is set to the correct angular and radial co-ordinates by use of the angularly adjustable work-table and the slide M<2>, and then the pin is set to the required distance, corresponding to the radius of the arc, from the axis of the microscope J<1>, after which, with the work-table free to rotate and the slide B free, the carriage C is moved. In a modification, the member M<8> is not used, a hollow member carrying the lens &c. being employed so that the image may be in view. In a modified form of the machine, the worktable and optical system are not rotatable, the work-table, however, being adjustable angularly. In a further modification, the work-table and the optical system are carried by a carriage given parallel movements by suspension on pivoted links. The microscopes and the tool may be mounted on the main carriage, the axes of the work-table and the optical system being fixed; or one pair of elements may be mounted to move along a fixed slideway, and the other pair to move in a direction at right-angles to the slideway. According to the Provisional Specification, in circular arc generation, the pivot pin is carried by the work-table or by an idler gear, and in a modified machine, the work and copy axes are coincident. Reference has been directed by the Comptroller to Specifcation 273,388, [Class 97 (ii)].