Patent GB-742970-A (GB)
Title: Improvements in or relating to optical apparatus
IPC: G02B5/00
Filed: 1953-10-23
Abstract: 742,970. Optical apparatus. EASTMAN KODAK CO. Oct. 23, 1953 [Oct. 25, 1952], No. 29340/53. Class 97 (1). Apparatus for testing the alignment of axes or the flatness of surfaces on a machine tool employs an optical system based on the principle illustrated in Fig. 1. A point source of light situated on the axis 15 to be aligned illuminates an optical member 10 so constructed that light reaching each point 11, 12 of the member is transmitted or reflected thereby in the form of a thin sheet of light 13, 14 respectively, passing through the axis 15 between for example, the points 16 and 17. The axis between these points receives light from all points of the member 10 so that in an observing instrument such as a microscope, focused on a point between 16 and 17 and aligned with the axis 15, an apparent image of the source may be seen. If there is no such alignment insufficient light will reach the objective of the microscope to give the appearance of an image of the source. The member 10 may be a ring-shaped toric lens, a conical lens member with a plano- or lenticular surface opposite the cone, an internally-reflecting tubular member cylindrical or conical or a conical reflector. The Specification describes a number of modifications and indicates a method by which the intensity of the light reaching the observing instrument may be calculated. The objective of the observing instrument may be replaced by a member similar to the member 10 producing the aligning beam. In the embodiments referred to hereafter the member takes the form of a light, transmitting or reflecting conical member. As shown in Fig. 32, a light source 152 is carried in the chuck 151 of a boring machine and sends light to a prism 153 observed against cross-wires 154 oy a microscope 155. Light source and microscope are aligned by moving the chuck 151 along the bed 150 and observing the deviations of the light spot by the microscope 155 an indication of the flatness of the bed may be obtained. Alternatively the microscope may be carried by the chuck and the light source and prism fixed to the stand 156 or several light sources arranged along the bed 150 may be viewed simultaneously. In a further modification the microscope and lamp are supported by the stand 156 while the chuck carries a conical reflector viewed by the microscope by reflection in an inclined mirror. In the system shown in Fig. 36, light from a source 191 passes a semi-reflecting surface 194 and a conical element 190 and is reflected back by a plane mirror for observation by a microscope 196, 197 after reflection in the mirror 194. A further modification is described in which the objective 196 is replaced by a conical member similar to the member 190 and through which the beam from the lamp 191 also passes, a second microscope system having an ordinary objective being arranged for alternative use. Fig. 47 shows a system for checking the alignment of two axes comprising a mirror 280 having a central aperture 282 and located in a glass body having lenticular members 286. a lamp is placed first at 281, light passing through the aperture falling on a conical reflector 283 aligned with one axis being observed by reflection in the surface 280 by a microscope 284. The lamp is then placed at 291, the microscope at 294 and observation again made by reflection in a conical reflector 292 fixed to the second axis, any divergence between the axes being thereby revealed. In the modification shown in Fig. 36 the cone 190 may be replaced by a concave meniscus lens having the cone on one surface, a positive lens axially aligned therewith being axially immovable to vary the position of the points 16 and 17 of Fig. 1. Further, two glass plates rotatable about axes at right-angles may be provided to adjust the position of the axis of the system.