Patent GB-190713306-A (GB)
Title: Improvements in or connected with Sighting Apparatus for Ordnance.
Inventor: BARR ARCHIBALD
Filed: 1907-06-08
Granted: 1908-06-09
Abstract: 1 3 , 3 0 6. Barr, A., and Stroud, W. June 8. Sights and methods of sighting.-Relates to sighting-apparatus for ordnance of the type in which one element is moved from a distant fire control station and a second element working in conjunction therewith is operated by the gunner, this second element working the gun sight in accordance with the range indicated by the first element. According to the present invention, the first element, termed the range element, receives a movement in direct proportion to the increment of range transmitted, and means are provided for indicating the corresponding increment of angle of the gun sight, although the increments of angle are not proportional to the increments of range. The second element is termed the sight element. The range element is preferably operated by means of a receiving motor mechanism operated by a transmitter at the fire-control station, and the sight element is mechanically geared to the apparatus by which the telescopic or other sight is actuated. The transmitting-instrument and receiving-mechanism may be of the type set out in Specification No. 4422, A.D. 1906, [Abridgment Class Registering &c.]. In the form shown in Fig. 1, one of the two elements embodies a cylindrical surface I upon which is marked a suitable helical, stepped, or other line J, the cylinder being rotated from the fire control station by means of a shaft F and worm gearing G, H in accordance with the range. The line J is thus moved out of coincidence with a pointer N on a bar M which has a pin-and-slot connexion with the bar B carrying the telescope A ; the duty of the gunner is to bring the pointer N again into coincidence with the line by means of the wheel 0 and the usual rack-and pinion gear P by which the telescope is elevated. The range may be indicated to the sight-setter by means of the apparatus E. In the form shown in Fig. 2, the cylinder is replaced by a disk V upon which a line W is marked, and the pointer S is carried by a nut R engaging a screw Q operated from the fire-control station. The pointer may be pivoted outside the circumference of the disk, and receive an angular motion. A cone may be used instead of a cylinder or disk. When the helical line comprises several convolutions, special means may be provided to indicate to which particular convolution the pointer or index is to be set. In one arrangement, the line is of varying width and the index takes the form of a gap between two pieces, the gap being automatically varied to correspond with the line by means of cam-and-lever mechanism. Two or more lines of different-colours may be marked upon the cylinder or disk corresponding to pointers of similar colour, in order to correct for full or half charges, different muzzle velocities, &c., or separate cylinders or disks appropriately marked may be provided, the particular one being placed upon the instrument for use. The sight-setter may be provided with an electric switch to indicate when the sight is correctly set, or to close the firing circuit, or. the same result may be attained automatically by making the helical &c. line of electric conducting- material and the index as a contact-maker, or the line may constitute the insulating-material, in which case the circuit is broken when the sight is correctly set.