US2502506A - Gun sight - Google Patents

Description

33-238. cm 2.502.506 SR 7 HEW? April 4, 1950 E. E. CHASE ET AL 2,502,506

GUN SIGHT Original Filed March 27, 1945 6 Sheets-Sheet l lnz/eniors ErnesZE Chase William VGooczhue Ernest TNo/ues April 4, 1950 E. E. CHASE ET AL 2,502,506

GUN SIGHT Original Filed March 27, 1945 6 Sheets-Sheet 2 T H R d, Z Inventor's ange a m frneszf Chas Component Comporzanz e I 9 Course I/VzUz'am T/Gooahue A '0 Ernes; l vokes i L251 ant Zhngentigl Fran/z E 525 a zzon 4' Line Of Sight Line Or" 51 m April 1950 E. E. CHASE ET AL 2,502,506

GUN SIGHT Original Filed March 27, 1945 6 SheetsSheet 3 lm/emors Ernest EChczse l/Vzliz'am VGoodhue Ernesz dNokes Frank E. Szr'azzon zh'eir'Azzorney April 4, 1950 E. E. CHASE ET AL GUN SIGHT 6 Sheets-Sheet 4 Original Filed March 27, 1945 lnveniors Erneszf. Chase Fran/c EGZrazfon April 4, 1950 E. E. CHASE ET AL 2,502,506

GUN SIGHT Original Filed March 27, 1945 6 Sheets-Sheet 5 nveniars ErnesZEChaSe LVN/2am T/Goodhue fr-nesz G. Nokes' gr'czrzlr ESzr-azzon iSEfiRCH ROE? April 4, 1950 E. E. CHASE ET AL 2,502,506

GUN SIGHT Original Filed March 27, 1945 6 Sheets$heet 6 lnz/enzo rs T15 9 rmeszzchase WZZZZc zm VGood/zue Ernesz Give/ 65 Patented Apr. 4, 1950 UNITED STATES PATENT OFFICE GUN SIGHT Original application March 27, 1945, Serial No. 585,150. Divided and this application July 19, 1946, Serial No. 684,864

1 Claim.

This invention relates to ordnance and is illustrated as embodied in an improved sight for use, for example, in, an armed turret disclosed in application for United States Letters Patent Serial No. 585,150, filed March 27, 1945, in the name of Ernest E. Chase et al., now Patent 2,450,541, granted October 5, 1948, the present application being a division of the above identified application.

It is an object of the present invention to provide an improved sight for use in said armed turret.

Various features of the invention will be understood and appreciated from the following detailed description read in connection with the accompanying drawings, in which Fig. 1 is a side view, partly in longitudinal vertical section, of the interior of an illustrative armed turret and of a gun and various mechanisms which are incorporated in and form part of said turret;

Fig. 2 is a diagrammatic view, showing various connections between the gun, a lead setting box, and sights of the turret;

Fig. 3 is a perspective view of a sight used by an azimuth tracker in the turret;

Fig. 4 is a section on line IV-IV of Fig. 3;

Fig. 5 shows the sight, partly in side elevation and partly in section on line V-V of Fig. 3;

Fig. 6 is a section on line VIVI of Fig. 5;

Fig. '7 is a view showing, partly in section and .partly in side elevation with covers removed,

portions of a turret, commanders sight and a lead setting box by the use of which the commander throws leads into the various sights;

Fig. 8 is a section on line VIII-VIII of Fig. 7;

Fig. 9 is a plan view of the lead setting box; and

Fig. 10 is a diagram used in connection with the description of azimuth and elevation lead setting mechanism.

The illustrative armed turret 38 which is disclosed in detail in said application Serial No. 585,150 comprises a Bofors 40 mm. gun 40 (Fig. 1) rate controlled electrically operated means for rotating the turret, together with the gun, in azimuth and the gun in elevation with relation to the turret, and manually operated mechanism for actuating said means, portions of said mechanism being operated by a turret commander for initially training the gun on a target. After the gun 40 has been trained on the target, the commander renders his rate control actuating mechanism inoperative, the training of the gun thereafter being turned over to azimuth and elevation trackers who are seated on stools 42, 44

2 (Fig. 1), respectively, and drive the turret, through mechanical connections, said connections at such time being adapted to actuate said rate controlled electrically operated means.

The commander, standing upon a platform 46 (Fig. 1) and observing or spotting the target through an open sight 48 (Figs. 1 and 2) mounted upon a cupola 50 of the turret 38, initially trains the gun 40 on the target by the use of a grip 52 (Fig. 1) forming part of rate control mechanism, a hatch cover 54 (Fig. 1) of the cupola at that time being open. The commander then moves to a seated position upon a stool 56, which is positioned above the platform 46, and shuts the hatch cover 54, the target thereafter being observed by him through an elbow telescope 58 (Figs. 1 and 2) as he trains the gun 49 on the target. While the gun 40 is being initially trained on the target theazimnthf-andelevationtrackers observe said taijgct...through-elbow..telescopes 60 '(Fi'gs. "1:2; 3 and 5), 62 (Figs. 1 and 2), respectively, extending outside the turret 38 and forming parts of sights hereinafter described.

When the commander has trained the gun 40 on the target he releases solenoid control buttons 64 (Fig. 1) located on the grip 52, thereby transferring control of the electrically operated means to the azimuth and elevation trackers who turn wheels. 66, 68 (Fi g. 1), respectively, to retain, through mechanism portions of which will be-described later, horizontal and vertical hairlines (not shown) of the elbow telescopes 60, 62, respectively, and accordingly the gun 40, on the target. The commander now being free to observe the fire on the target, throws leads into the elbow telescopes 58, 60 and 62 by turning azimuth and elevation wheels ID, 12 (Figs. 1, 2, 8 and 9) of a lead setting box 14 in accordance with the observed trajectory of tracer bullets fired at the target, thereby causing the trackers to shift the fire to the target, if necessary, and thereafter to maintain said fire upon the target as it changes its speed and/or direction.

There is provided in a front wall of the turret 38 an arcuate opening I22 (Fig. 1) sufiiciently large to permit elevation of the gun through ranges varying from minus 15 to from the horizontal and a small opening I24 in the lower front portion of the turret for the reception of a chute I26 for disposing of empty cartridge cases. There are also provided at the right side of the turret 38 three openings I28 for receiving sights I30 formed in part by the elbow telescopes 58, 60, 62.

A pair of trunnions [32 (Figs. 1 and 2) secured to a breech casing or receiver I34 of the gun 48 are mounted for rotation in horizontal bores of trunnion blocks I36 (Fig. 1) bolted to trunnion block supports I38, which are bolted or otherwise rigidly secured to a floor of the turret and are connected together by a transverse cylindrical web (not shown). Accordingly, the gun rotates with the turret for training in azimuth and is rotated about a common axis I44 (Fig. 2) of the trunnions I32 with relation to the turret for training the gun in elevation. In order to swing the gun in elevation, there is secured to the breech casing I34 of the gun a segment gear I46 (Figs. 1 and 2) driven by a gear I48 which is rotatable, in response to movement of the rate control mechanism actuated by the commander's grip 52 or in response to movement of the elevation trackers wheels 68 and the rate control mechanism actuated by said wheels.

Sight drives from gun elevating mechanism In order automatically to vary the elevation of the three elbow telescopes 58, 68, 62 and the open sight 48 in accordance with changes in the elevation of the gun 48, a gun elevating shaft I24 (Fig. 2) to which the gear I48 is pinned has secured to its right end a bevel gear 8) which is enclosed in a housing (not shown) secured to one of the trunnion block supports I38 and meshes with a bevel gear 8I4 secured to the upper end of a vertical driving connection (H6. The lower end of the driving connection 8; has secured to it a bevel gear 8I8 which is rotatably mounted in a housing (not shown) secured to one of the trunnion block supports I38 and drives a bevel gear 822 secured to a horizontal shaft 824 mounted for rotation in said housing. The shaft 824 is operatively connected through a drive 825 (Figs. 1 and 2) extending along the floor and the right side wall of the turret to a bevel gear 826 secured to the lower end of an input shaft 828 extending upward into the lead setting box I4. As will be explained later, changes in the elevation of the gun 48 and in the elevation deflection angle between the elbow telescopes 58, 68, 62 and the gun are added algebraically in a differential 838 (Fig. 7) which is operatively connected to the shaft 828 and which, through mechanism hereinafter described, drives an elevation output shaft 832 of the lead setting box I4. The connections between the elevation output shaft 832 of the lead setting box I4 and the elbow telescopes 58, 68, 62 will be described later.

Sights As above stated, the elbow telescopes 58, 66, 62 may be angularly adjusted in azimuth and in elevation with relation to the gun to vary the azimuth and elevation deflection angles between the gun and the sights, through mechanism which will be described presently and is operated by the commander as he observes the efiect of fire upon the target. The sight mechanism through which the elbow telescopes 58, 68, 62 are angularly adjusted in elevation and in azimuth with relation to the gun is identical.

Each of the sights I38 comprises an elbow telescope 58, 68 or 62 having a pair of ribs 848 (Figs. 3, 5 and 6) and mounted upon the ribs is an adapter sleeve 842 (Fig. 5) which is rotatable in a cylindrical bore 844 of a block 846 comprising two parts secured together by screws 841 (Figs. 5 and '7). The adapter sleeve 842 has a portion 848 (Fig. 6) of reduced diameter provided with a pair of slots 858 in which fit extensions I (Figs. 5 and 6) of one of the ribs 840 of the telescope. The block 846 has formed integral with it an upper trunnion 852 (Figs. 3, 4 and 5) and secured to it by screws 854 (Fig. 5) is a lower trunnion 856 (Figs. 3, 5 and 7), said trunnions being swiveled for rotation about a common axis 858 in bores 868, 862 of a housing 864. The housing 664 of the sight I38 is rotatably mounted upon a hanger pin 866 (Figs. 3 and 5) supported by a bracket 868 secured by screws 818 to the wall of the turret 38. The sides 812 (Fig. 3) and a gear box 884 of the housing 864 are formed integral and are secured by screws 816 (Figs. 3 and 4) to the top of the housing, the housing being secured in its vertical position upon the hanger pin 866 by nuts 818 (Figs. 3, 5 and 7) threaded onto a screw 889 which passes through an enlarged recess 882 (Fig. 5) of the housing and is secured to the turret wall. In order to insure that the axis 858 of the trunnions 852, 856 shall be exactly vertical, a spirit level 884 (Fig. 3) is secured to the housing 864. The inner vertical faces 886 (Fig. 4) of the housing 864 are cylindrical and are centered about the axis 858 of the trunnions 852, 856, the curved lateral sides 888 of the block 848 being complemental to and just clearing the faces 886 of the housing.

Mounted in a recess 898 (Fig. 5) of the block 846 is a bevel gear 892 (Figs. 3, 5, 6 and '7) which is secured to a flange of the adapter sleeve 842 by screws 894 (Figs. 3, 5 and 6), a two-part plate 896 being forced by screws 898 against the inside faces of the block and the inner rib 848 of the elbow telescope 58, thereby insuring against movement of said telescope lengthwise of its axis 988 (Figs. 3 and 5) with relation to the block 846. Secured by screws 982 (Fig. 5) to the adapter sleeve 842 is a hood 984 which affords protection for the portion of the telescope 58 extending outside of the turret. Since the elbow telescopes 58, 68 and 62 are of the standard type now in use it will not be necessary to describe said telescopes in detail.

In order to swing the block 846 into different angularly adjusted positions about the axis 858 of its trunnions 852, 856 to vary the azimuth deflection angle between the gun 48 and the elbow telescope 68, the trunnion 856 has keyed to it an azimuth worm gear 986 (Figs. 3, 5 and '7) which meshes with an azimuth worm 988 pinned to a shaft 8 I 8 which, as will appear later, is operatively connected to an azimuth output shaft 9I2 (Figs. 1, 2, 7, 8 and 9) of the lead setting box I4, which, as above explained, is controlled by the commander.

To rotate the elbow telescope 68 in the block 846 about its horizontal axis 988 the bevel gear 892, which is secured to the adapter sleeve 842, meshes with a bevel gear 9M (Figs. 3, 5 and. '7) which is arranged in a recess of the block and is fixed to the upper end of a shaft 9l8 fitting in a concentric or coaxial vertical bore of the trun nion 856. Secured to the lower end of the shaft 9I8 is an elevation gear 928 (Figs. 3 and 5) meshing with an elevation worm 922 rotated by and also movable lengthwise along a shaft or rotatable drive member 824 rotatably mounted in the gear box 814 of the housing 864.

It will be apparent that rotation of the elbow telescope 58 about the axis 858 of the trunnions 852, 856 will, unless compensated for, cause the bevel gear 892 to turn about the horizontal axis 988 and introduce an elevation error into the sight. In order to insure against this occurring, the worm 922 during movement of the block 846 about the axis 858 of the trunnions 852, 856 is moved relatively to the shaft 924 by a yoke 926 secured by screws 928 to a rack 930 which is slidable lengthwise in bores 932 (Fig. 7) of the gear housing 814 and meshes with a compensating gear 934 (Figs. 3 and 5) secured to the trunnion 856 and having the same pitch diameter as the gear 929. With such a construction it will be apparent that when the block 846 is swung about the vertical axis 858 of the trunnions to vary the azimuth lead. the worm 922 slides along its shaft 924 the proper amount to insure against the gear 892 being rotated with relation to the block about its axis 988.

As above explained, the proper lead corrections are made in the lead setting box 14, which is operated by the commander in accordance with his observation of tracer bullets fired upon the target.

Lead setting box Since the gun 48 moves in azimuth, together with the turret 38, it is only necessary to swing the elbow telescopes 58, 68, 62 about the axis 858 (Figs. 3 and 5) of their trunnions 852, 856 in order to give the gun the proper lead in azimuth. It will be apparent, however, that since the gun is moved in elevation with relation to the turret it is necessary to have each of the elbow telescopes swing about its horizontal axis 908 to the same degree that the gun swings about the axis I44 (Fig. 2) of its trunnions I92 and to add to such movement the desired lead in elevation. As above stated, the elevation deflection angle may be varied by the commander by rotating the hand wheel 12 which is fixed to the outer end of a shaft 936 (Figs. '1 and 8) journaled in a bearing of the lead setting box 14. Pinned to the inner end of the shaft 936 is a bevel gear 938 meshing with a bevel gear 948 secured to an upstanding shaft 942 to which is pinned a worm 944 meshing with a gear 946 keyed to an index shaft 948. Pinned to the rear end of the shaft 948 is a large gear 959 in driving relation with a smaller gear 952' (Fig. '7) secured to a lower horizontal shaft 954 rotatably mounted in the lead setting box. Rotation of the shaft 954 is transmitted through bevel gears 956 to an input shaft 958 of the above-mentioned differential 838 (Fig. '1). As above stated, changes in elevation of the gun are introduced into the differential 898 by the elevation input shaft 828 (Figs. 1, 2 and '7) which is movable in response to movement of the segment gear I46 (Figs. 1 and 2) of the gun 48. The elevation components from the lead setting box and the gun elevation input shafts 958, 828 are added aglebrai'cally in the differential 838, which comprises a cage 968 (Fig. '7) to which is secured a gear 962 (Figs. 7 and 8) meshing with a gear 964 fixed to the elevation output shaft 832 which is operatively connected through driving connections 966 (Figs. 1, 2 and '7) to the elevation shafts 924 (Figs. 2, 3, 5 and 7) of the commanders and trackers sights.

In order to register the elevation deflection angles, there are provided index and Vernier dials 968, 918 (Figs. 8 and 9) which are calibrated in mils and are viewed through a window 91I (Fig. 9) in the top of the lead setting box 14. The dials 968, 918, respectively, are freely mounted upon and pinned to the shaft 948, the index dial 968 being rotated at one-ninth the speed of the Vernier dial 918 by means ofa gear train com- 6 prising a gear 912 (Figs. 7 and 8) pinned to the shaft 948, a pair of idler gears 914 mounted upon a fulcrum pin 916 fixed to the lead setting box 14, and a gear 918 freely rotatable upon the shaft 989 and pinned to the index dial 968. In the illustrative construction the maximum lead of the gun in elevation is approximately 450 mils, or about 25, the index dial at such time having been rotated slightly less than one-half of a revolution to the right or to the left from its neutral position, shown in Fig. 9, in which position the zero marks on the dials register with marks 988 on the lead setting box 14.

The azimuth lead of the gun is varied by the rotation of the hand wheel 18 which is pinned to the outer end of a shaft 982 (Figs. '1 and 8) journaled in the lead setting box 14. Secured to the inner end of the shaft 982 is a bevel gear 984 meshing with a bevel gear 986 pinned to a vertical shaft 988 which carries a worm 998 in driving relation with a gear 992 secured to an index shaft 994. Pinned for rotation with the shaft 994 is a vernier dial 996. The inner end of the shaft 994 has secured to it a gear 998 (Fig. 8) driving a compound gear I888 operatively connected to a gear i882 which is fixed to the azimuth lead output shaft 9I2 (Figs. 1, 2 and 7). The shaft 9I2 through upwardly extending driving connections I884 (Figs. 1, 2 and 7) operates the shaft 9) (Figs. 3, 5 and 7) of the commanders sight I38 and through driving connections I899 (Figs. 1 and 2) extending downward and along the right wall of the turret operates the shafts Bio of the trackers sights I38.

Freely mounted upon the shaft 994 (Figs. 7 and 8) is an index dial I888 (Figs. 8 and 9), and secured to the shaft is a pinion I8I8 which meshes with a compound gear I8I2 which is rotatably mounted upon a fulcrum pin I 8 I4 secured to the lead setting box 14 and which meshes with a gear I8I6 rotatably mounted upon the shaft 994 and pinned to the index dial I888, the arrangement being such that the index dial partakes of one-ninth 0f the rotation of the shaft 994 and accordingly the Vernier dial 996. In the lead setting box 14 is a window I8I8 (Fig. 9) through which the commander may observe the amount of lead in azimuth. The calibration of the azimuth Vernier and index dials 996, I888 is similar to that of the elevation Vernier and index dials 919, 968. As in the elevation lead setting mechanism, the maximum lead in azimuth is 450 mils, or approximately 25.

The course of a target ma be divided into two components, one tangential and the other radial to the line of sight. In tracking the target the tangential component is considered in computing the azimuth lead and the radial component is considered in computing the elevation lead.

When the tangential component is clockwise, as viewed from above (Fig. 10) the azimuth lead, that is, the lead of the gun in relation to the line of sight as viewed from above, is also clockwise. It will be apparent that the tangential component remains in the same direction so long as the target remains on the same general course, such, for example, as from A to B. Should the target reverse its course, the azimuth lead would be counterclockwise.

It will be noted, however, that the radial component changes from an inward or incoming direction, shown at A, Fig. 10, to an outward or outgoing direction, as shown at B, during travel of the target in its course from A to B. Accordingly, while following the target through course A to B, the elevation lead will have to be changed from an inward to an outward one. The inward elevation lead may be said to require an upward vertical deflection of the gun from its line of Sight and the outward lead may be said to require a downward vertical deflection of the gun from th line of sight. It is evident that the elevation lead will be maximum at the extreme ranges A or B and will be a minimum at the minimum range C, the elevation lead changin in direction at this point. The course A to B may be referred to as a clockwise course, the portion of the course to the left of the minimum range point C being considered the incoming part of the course and that portion of the course to the right, the outgoing part of the course. It will be understood that for a clockwise direction course the gun will have an upward vertical deflection for the incoming part of the course and a downward vertical deflection for the outgoing part of the course. This will also hold true for a course where no tangential component is present.

Whenthereis noleadinazimlltn the zeros on the index and Vernier dials I008, 996 of the azimuth lead setting mechanism are in alinement with marks IOI9 (Fig. 9) on the lead setting box 14, and when there is no lead in elevation the zeros on the vernier and index dials 968, 910 of the elevation lead setting mechanism are in alinement with the marks 980 of the lead setting box. 0

When the commander rotates the azimuth wheel 10 clockwise, as viewed from the front of the lead setting box I4, there is provided a clockwise lead in azimuth, the azimuth index and Vernier dials I008, 996 moving in the direction of the arrow I02I, the dial numbers which increase progressively to the left from zero and are colored blue then being read. When the commander rotates the azimuth wheel I0 in a counterclockwise direction from its neutral position, a counterclockwise lead in azimuth is provided, the dials I008, 996 moving in a direction opposite to the direction of the arrow I02I and dial numbers which increase progressively from the right of zero and are colored white being read.

When the elevation wheel I2 is rotated clockwise, as viewed from the front of the lead set-, ting box 14, from a neutral position in which there is no lead in elevation and in which the zeros on the index and Vernier dials 968, 910 are in registration with the marks 980 on the lead setting box I4, the gun will be given an outgoing lead in elevation, the dials moving in the direction of the arrow I023 and the commander reading blue dial numbers which increase progressively to the left from zero, as viewed in Fig. 9. When the elevation wheel 12 is turned counterclockwise, the gun will be given an incoming lead, the dials 968, 910 moving in a direction opposite to the direction of the arrow I023 and white dials numbers which increase progressively to the right from zero being read.

In order to insure against breakage of the lead setting mechanism above described due to applying too much force to the wheels 10, 12, there' are provided stops I028 (Figs. 7 and 8) which, when the index dials 968, I008 operatively connected to the elevation and azimuth lead setting mechanism have been rotated just less than one-half of a revolution and accordingly register approximately 450 mils, are engaged by abutments I022, best shown in Fig. 7, formed upon collars I024 secured to the shafts 936, 982. The mechanism for operating said stops I020 comprises cams I026 (Fig. 7) carried by the index dials 968, I008, re-

spectively. Secured to the inner ends of shafts I028 which are journaled in the lead setting box 14 and to which the stops I020 are pinned are levers I030. Just before the index dials 968, I008 have reached the limits of their movement, the levers I 030 are engaged by the cams I026, causing the stops I020 to be raised into positions to be engaged by the abutments I022 on the collars I024, thus preventing the shafts 936, 982 from being turned any farther by the commander. During the normal operation of the lead setting device, the stops I020 are held in their depressed positions, shown in Fig. 7, against screws I08I out of the path of movement of the abutments I022 by springs I032 which operate against the levers I030.

In order that the commander while viewing the target may have a, fair idea of the magnitude of the leads in azimuth and elevation, there are provided clicker devices comprising recessed disks I034 (Figs. 7 and 8) which are secured to the forward ends of the index shafts 948, 994 and are engaged by leaf springs I036 secured by screws I038 to the lead setting box 14. For every 25 mils of rotation of each of the index shafts 948, 994 one of the springs I036 falls into a depression I040 of the associated disk I034, causing an audible click.

Having described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

In a gun sight, a block having trunnions mounted for rotation about an axis, an elbow telescope mounted for rotation in the block about a second axis arranged at right angles to the firstnamed axis, a shaft rotatable in one of the trunnions in coaxial relation with the first-named axis, intermeshing bevel gears secured to said shaft and to the elbow telescope respectively, an azimuth worm gear fixed to one of said trunnions, flgzlmljh worm meshing with the azimuth worm gear, means for operating the azimuth worm to move the blocl; together with theelbow telescdiYe aboiit'said'first-na'ind "axis, an leya on worm gear secured to the shaft, a rotatable drive member, an elevation worm which is mounted for rotation with said drive member and is slidable on said member, a compensating gear which has the same pitch diameter as the elevation Worm gear and is secured to the trunnion, a rack meshing with the compensating gear and constructed and arranged to slide the elevation worm on the rotatable drive member in response to rotation of the compensating gear to rotate the elevation worm gear and accordingly the bevel gear secured to the shaft a sufficient number of degrees to insure that rotation of the elbow telescope in azimuth shall not effect rotation of the elbow telescope in elevation.

ERNEST E. CHASE. ERNEST S. NOKES. FRANK E. STRATTON. WILLIAM V. GOODHUE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 433,020 McKellen July 29, 1890 1,233,929 Strate July 17, 1917 1,412,758 Sperry et a1. Apr. 11, 1922 2,372,613 Svoboda 1. Mar. 27, 1945 2,385,348 Chafee Sept. 25, 1945 2,407,665 Holschuh Sept. 17, 1946

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