GB780136A - Improvements in or relating to rifle rear sights - Google Patents

Abstract

780,136. Backsights for rifles. ROBERTSON, D. June 27, 1955 [July 2, 1954], No. 18531/55. Class 119. A backsight for a rifle is so constructed that when the sight has been accurately set relative to the rifle, the scales may be zeroized without altering this setting. According to the invention a block 31 provided with a sighting notch or aperture 32 is movable by screw means along a horizontal bar 6 which itself can be adjusted vertically by screw means along a vertical bar 2, the screw means being operated by turning nuts 13a, 13 carrying scales 17a, 17, the scales being rotatably mounted with respect to the nuts and adapted to be locked to the nuts by grub screws. Radial depressions may be provided on the inner face of each nut and a spring-loaded ball provided in an adjacent collar so as to give a positive location of the nut at positions corresponding to the radial depressions. Zero marks 24, 24a for the scales 17. 17a are provided on the bars 2,' 6 respectively. Fixed to the vertical bar 2 is a scale 26 fastened by screws 27 passing through slots 28,'the scale having calibrations 29 which indicate hundreds of yards. A zero mark 30 for this scale is provided on the horizontal bar 6. The aperture block 31 is provided with scale markings 33 and a zero strip 34 is fastened to the bar 6 by a screw 35 passing through a slot 36. Having set the sight accurately by repeated shooting at a set target, the nuts 13. 13a may be. for example, a half revolution away from the zero positions: the scales 17. 17a are then released from the nuts and rotated without altering the setting of the nuts until the zero positions of the scales are in their correct positions relative to the zero lines 24. 24a. The scales 17a. 17 are then locked to the nuts 13, 13a in their zeroized positions, and the height scale 26 and the zero strip 34 adjusted so that the zero lines of these coincide with the required indicating lines on the scales.