Patent GB-191002236-A (GB)
Title: Improvements in Telescopes.
Inventor: MOELLER CARL
IPC: G02B23/08
Filed: 1910-01-28
Granted: 1910-08-04
Abstract: 2236. M÷ller, C. Jan. 28. Telescope systems; periscopes. -In telescopes for ordnance, adapted to measure angles and provided with rotatable reflectors, the objective 23, shown in Fig. 2, which is a cross-section on the line A-A of the front elevation, Fig. 1, and the fiducial mark 24 on the lower face of a glass disk 104 are mounted in a single tube 25 rotatable round a vertical axis in a frame 75 rigidly connected with the gun. The reflector 22 for receiving rays from the object is mounted so as to be turned with the tube 25 while maintaining its position with respect to the objective and the fiducial mark. Preferably the reflector 22 is mounted in a hood 28, so as to be rotatable about the horizontal axis 29. Reflecting- surfaces are provided in the incident prism 22 and in the horizontal ocular tube 1 for laterally correcting and for erecting the image respectively. The means described for tilting the incident reflector 22, and for rotating the tube 25 carrying the objective and fiducial mark about its axis and for measuring the angles of rotation are as follows. The bottom of the rocking casing 30 of the incident prism 22 is spring-pressed against the upper end of a bolt 42 passing through an annular plate 25<1> screwed to the tube 25 and resting upon the upper end face of a nut 48, which can be rotated to move up or down the tube 26 carrying the tube 25 and so raise or lower the bolt 42 to tilt the prism casing. The nut 48 is rotated by means of a knurled head 43 actuating a bevel-wheel gearing with bevel teeth on the lower edge of a ring 46, which is connected with the nut by means of pins 47 engaging in longitudinal grooves in the lower part of the nut 48. For indicating the angle, the nut 48 is formed with an external spiral groove 58, in which engages a rib on an indicator 59, Fig. 1, for use with a scale on the outside of the nut 48 visible through an opening 53 in an outer covering- tube 52, the indicator 59 being secured against rotation by a groove-and-feather connexion with the outer tube 52. The tube 25 is rotated by turning the ocular tube 1 on its axis, a gearwheel 79 on the ocular tube meshing with a pinion 77 rigidly connected with a bevel-wheel 78 meshing with a large bevel-wheel 62, which is made in one with a worm-wheel 60 secured on the lower end of the tube 25. A fine adjustment of the tube 25 can be effected by means of the worm 63 gearing with the worm-wheel 60, one end of the worm spindle 60 being provided with a spherical pivoted bearing to enable the worm 63 to be pushed horizontally against spring pressure and disengage the worm from the worm-wheel when using the coarse adjustment by rotation of the ocular tube 1. The angle is indicated by means of a scale 94 on a ring 72 secured to the worm-wheel, and by means of graduations 69 on the head 68 for actuating the worm. The optical elements are shown in section in Fig. 2, and in front elevation, corresponding to Fig. 1, in Fig. 7. The incident prism 22 has four operative faces, namely two transmitting - faces 120, 121 at right-angles to each other, and two reflecting- faces 105, 106 at right - angles to each other, their line of intersection 1040 being at an angle of 45 degrees with the transmitting - faces. Below the disk 104 carrying the fiducial mark 24 is a plano-convex lens 92 and a reflecting prism 84 with an upper spherical face. The ocular tube 1 contains a bed 4, in which are mounted a prism a and a glass body b. The prism a has a transmitting - face 115, and a reflecting-face 117 at an angle of 30 degrees with a reflecting-face 116 parallel with the axis of the ocular tube, the face 117 serving also as a transmitting - face. The glass body b is rectangular in cross-section, and has a plane face 118 at right - angles to the axis of the ocular tube, a reflecting-face 119 at an angle of thirty degress with the axis, and a spherical face 101 in proximity to the reflecting-face 117 of the prism a.