US2552554A

US2552554A - Rate responsive gun sight computer

Info

Publication number: US2552554A
Application number: US606698A
Authority: US
Inventors: John H Holstein
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-07-23
Filing date: 1945-07-23
Publication date: 1951-05-15
Anticipated expiration: 1968-05-15

Description

May 15, 1951 J. H. HOLSTEIN RATE RESPONSIVE GUN SIGHT COMPUTER 4 Sheets-Sheet 1 Filed July 23, 1945 gunnen/HOI May 15, 1951 J. H. HOLSTEIN vRATE RESPONSIVE GUN SIGHT COMPUTER Filed July 2:5, 1945 4 sheets-sheet 2 May 15, 1951` J. H. HOLSTEIN 2,552,554

RATE RESPONSIVE GUN SIGHT COMPUTER Filed July 23, 1945 4 Sheets-Sheet 5 S @Emy/MM ma May 15, 1951 v JQH. HOLSTEIN 2,552,554

Y' RATE RESPONSIVE GUN SIGHT COMPUTER Filed July 2s, 1945 '4 sheets-sheet 4 l v l IEE El- FE E- f-y E 165 y /60 762` /65 /6/ /62 [nu 760 76; lr; 175 /671 174 Patented May 15, 1951 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 O. G. 757) Claims.

The invention described herein may be manuiactured and used by or for the Government for governmental `purposes without the payment to me of any royalty thereon.

This invention relates to mechanisms for determining angular or linear rates and for combining such rates with one or more variables to obtain a desired result or product. More particularly, the invention r tes tofthe`directing of guns at angularly ving, argetswwhei'ein it s"cu'stci'rhary tohcaiise the gun to lead the tar- `get"b`y 'an langle at the gun, relative to the line from the gun to the instantaneous position of the target equal to the angular rate of movement of the gun multiplied by the range or the time of flight of the projectile, the two being approximately the same. In other words, ignoring super-elevation, the lead angle is the angle subtended at the gun by the change in target positions, between the time the projectile leaves the gun and the instant of impact.

It is an object of the invention to provide a rate-'resp0asireriericaoi,general uti1ity, put particularly valuable for use in contin with the directing of guns, as previously mentioned.

A further object is to provide a rate responsive device, as aforesaid, that is entirely mechanical in construction, and one that is rugged and capable of withstanding the shocks incident to gun re, while, at the same time, being relatively simple to construct, operate and service.

Another object is to provide a rate responsive mechanism that will differentiate between opposite directions of rotation so that the lead angle may be reversed for respectively opposite directions of travel of a target.

A still further object is to provide a rate responsive mechanism, as in the preceding paragraphs, in combination with a range, or time of flight multiplier, whereby the deflection angle may be measured or transmitted directly to correspondingly alter the angular relation or lead, between the gun and its sight or other means for establishinggthe instargznegusgline between lll-liioll-andtarsi Another object is to provide in combination with a rate responsive mechanism operated by elevational movement of the gun, a device directly connected to, and operated by said mechanism, to introduce the proper correction for super-elevation.

Other objects and advantages of the invention will become apparent as the description advances.

In the drawings:

Fig. l shows my invention as applied directly to a gun;

Fig. 2 shows a rate-responsive unit, partly in section, and suitable for use either to measure the angular movement of the gun in train or in elevation, and in both directions of movement;

Fig. 3 shows an elevation rate responsive mechanism such as is shown in Fig. 2, directly coupled to a mechanism for introducing the necessary corrections for super-elevation;

Fig. 4 is an enlarged sectional detail on line 4 4, Fig. 2, showing the brake or clutch mechanism provided to make sure that each governor rotates only in response to a corresponding direction of rotation of its input shaft;

Fig. 5 is an enlarged sectional detail view taken on the line 5 5, Fig. 2, showing the clutch mechanism provided to prevent the corresponding governor from rotating at a speed greater than that of its driving shaft;

Fig. 6 is a side elevation, partly in section, of

a mechanism for multiplying angular rate by range or time of flight of projectile. Fig. '7 is a front elevation corresponding to Fig. 6 and showing how the train and elevation multipliers may be mounted side by side for convenience of adjustment;

Fig. 8 is a front elevation of one form of sight and the connections for adjusting it vertically and laterally from the multiplier of Figs. 6 and 7;

Fig. 9 is a side elevation of the sight shown at Fig. 8 and Fig. 10 is a side elevation of another form of sight suitable for use with the invention.

General description of invention Referring to Fig. 1 wherein I have shown an embodiment of the invention applied to a gun, Ill indicates a fixed base of a gun placement, having a ring gear I I fixed therewith. The base I2 of a gun mount is rotatable about a vertical train axis and carries a pair of trunnion supports I3. The cradle I4 of a gun I5 has trunnions I 6 journaled in supports I3 and held in place by bearing caps I'I. A bracket I8 is bolted to base I2 adjacent the periphery thereof and journals a shaft I9 having a pinion 20 keyed thereto and in mesh with ring gear II. Shaft I9 is connected to a flexible shaft drive 2| connected to a rate device 22, so that, as the gun is trained by mechanism not shown, to rotate base I2 relatively to gear II, the flexible shaft element 2| is rotated at a rate proportional to the rate of train.

A gear 23 is fixed to the end of trunnion I6, while a bracket 25 is fixed to bearing cap I'I and journals a second gear 24 to mesh with gear 23 so that gear 24 rotates as the gun is elevated about the axis of trunnions I6. A flexible shaft 26 is connected to be driven by gear 24 and, in turn, drives a gear 21 journaled within a control box 28 carried by a bracket 29 bolted to support I3. Gear 21 meshes with and drives a pinion 3! within box 28 that in turn, is connected to drive a flexible shaft 3l extending to an elevation rate device 32. These

rate devices

22 and 32 form an important part of the invention and will be subsequently described in detail. Suffice it to say, for the general description, that a flexible drive 33 leads from device 22 and is turned in proportion to the instantaneous value of the rate of train of the gun and enters a multiplier 34 where said rate is multiplied by range or time of ight. The resulting product appears as a rotation of a flexible shaft 35.

A sight 36 of any suitable type, is mounted on hoizontal trunnions 31 carried by a support 38 that, in turn is pivoted upon a vertical axis on box 28. Support 3B has a gear sector 39 fixed therewith, concentric of its pivot axis, and adapted to be driven by a worm 40 connected with flexible shaft 35. As this shaft is driven in proportion to the proper lateral deflection or lead measured in the slant plane through the target, it will be clear that the gun is correspondingly deflected relatively to the target as it is moved to maintain the line of slight xed upon the target.

Gear 21, previously mentioned, is mounted upon a shaft having thereon a bevel gear forming one side of a differential 4|. A flexible drive 42 leads from elevation rate device 32, to multil plier 34, where the said rate is multiplied by time of flight and the resulting product is transmitted by exible drive 43 to the other side of differential 4|. The center of differential 4l is thus turned in accordance with the algebraic sum of gun elevation and elevation lead. Said center is connected by a flexible drive 44 with a worm 45 journaled on a vertical axis on one support 38 and meshing with a gear sector 46 fixed to sight 36. In this way the gunis given the proper lead in elevation relatively to the line of sight as it is elevated to maintan the line of sight upon the target. The constructon of the multipliers will be explained in detail at a subsequent portion of the specification. The parts within box 28, may be protected by a door 41 having an opening 48 through which the adjustable parts of the multiplier may be operated.

The train rate mechanism The train rate mechanism is shown in detail at Figs. 2, 4, and 5. A frame 56 is shaped to define an opening 5l in its lower portion within which fits a bearing sleeve 52. A shaft 53 is journaled within sleeve 52, by anti-friction bearings 54 and 55 and has a bevel pinion 56 fixed to its end. Shaft 53 is connected to be driven by flexible shaft 2l, Fig. 1, in accordance with the rate of train of the gun. Frame 50 supports bearings 51 and 58 defining an axis at right angles to shaft 53. These bearings carrying a sleeve 59. having reduced ends as shown at Fig. 2. A second sleeve 60 is keyed to each reduced end and the right hand sleeve, as viewed in Fig. 2, has a bevel pinion 6l fixed thereto and in mesh with pinion 56. An outer governor sleeve 62 is mounted upon each sleeve 60, by anti-friction bearings 63. This sleeve is formed to support fly-ball or

governor arms

64 and 65 for pivotal movement about axes normal to, and spaced from, the axis of

sleeves

59 and 66. An inner governor sleeve 66 slidably fits sleeve 62 and is shaped to pivotally support

links

61 and 68, at its outer end. These links have their other ends connected to respective arms 64 and B5 so that, as

sleeves

62, 66,

arms

64, 65 and links 61, 618 rotate in unison, centrifugal forces act to move the weighted ends of

arms

64 and 65 outwardly and thereby to move sleeve 66 axially within and along sleeve 62.

A shaft 69 is slidable axially within sleeve 59 and adjacent each end carriers collars 1i) and 1l whereby each sleeve 66 is swivelled upon said shaft. Thus, an increase in the rate of rotation of the right handgovernor, Fig. 2, will cause a translation of shaft 69 to the left, while an increase in the rate of rotation of the left hand governor will cause translation of said shaft to the right.

Two governors are provided in order to distinguish between opposite directions of rotation of shaft 53; and I therefore provide over-running clutch devices between each outer sleeve 62 and sleeve 66. One of these is shown at Fig. 4, where it will be noted that sleeve member 63 carries the inner or toothed wheel 12, of a clutch device. The end portion of sleeve 62 closely surrounds member 12 and balls 13 are interposed in each of the pockets to thus form an over-running clutch. It will be understood that, while the clutch of the left-hand governor, Fig. 2, may be identical in construction, its toothed wheel is reversed with respect to wheel 12, so that one governor is rotated for one direction of rotation of shaft 53, while the other governor is rotated for the other direction of rotation of said shaft.

In order to make sure that friction or drag between the parts does not cause one governor to rotate when the rotation of shaft 53 corresponds to the rotation of the other governor, I provide a second over-running clutch comprising the toothed periphery of a disc 14, an outstanding rim 15 carried by frame 5i! and balls 16 within the pockets thus formed. In this manner, each governor, while free to rotate in its intended direction is positively prevented from rotating in the opposite direction so that any errors that might be introduced by undesired rotation of either governor are prevented.

To assure instantaneous response to a decrease in the train rate, means are provided to prevent the governors from rotating faster than the rotation of sleeve 59, such as might take place, for example, when there is a sudden decrease in the rate of train. For this purpose, the inner surface of sleeve 66 is formed with cylindrical surfaces of two different radii, separated by a shoulder. The surface of larger radius is so dimensioned as to remain entirely out of contact with the balls 18 of a clutch shown at Fig. 5 when sleeve 66 is so positioned that said surface is directly opposite said balls. The surface of smaller radius is so dimensioned that when it overlies the balls 18, the clutch is rendered operative. The shoulder between the two surfaces will lie just outwardly of the plane of balls 18 when the governor is at rest while as soon as the governor starts to rotate, sleeve 66 is moved axially inward so that the smaller diameter portion is brought opposite to the plane of the clutch to thus effectively prevent sleeve 66 and its attached governor parts from rotating at a greater rate than sleeve 60. It will be obvious that the right hand governor as Viewed in Fig. 2, is driven for a clockwise rotation of sleeve 59 as viewed in Fig. 4. From inspection of Fig. 5, it will be apparent that with such a direction of rotation, the speed-reducing clutch does not operate so long as

sleeves

62 and 66 are being driven by and from sleeve 60 through the clutch including balls 13. However, on a sudden decrease in speed of

sleeves

59 and 60, the momentum of the governor parts will tend to cause them to continue rotation, or coast at the previous speed, whereupon, balls 18 ride up the teeth upon Wheel 11 and effectively act to quickly equalize the speed of rotation of the governor parts with that of

sleeves

59 and 60.

The governor at the left, Fig. 2, is a duplicate of the one just described except only that the respective toothed clutch wheels are reversed with respect to the corresponding

wheels

12, 14 and 11 just described. The same reference numerals, primed, have therefore been used to indicate corresponding governor parts. Frame 50 is formed with rabbets 19 and 80 to receive the edges of protective covers 8| and 82. In this manner, shaft 69 is axially translated in one direction by one governor, and in the opposite direction by the other governor. In each situation, the amount of translation is proportional to the speed of rotation of shaft 53 and when one governor is controlling shaft 69, the other is positively prevented from interfering with, or in any way inuencing, said control.

The elevation rate mechanism In the case of train rate device 22, the translation of shaft 69 is directly transmitted to the multiplier for introducing the effects of range. However, in the case of the elevation rate device, an algebraic correction for super-elevation is required. This is conveniently introduced by the mechanism shown at Fig. 3 wherein the rate device itself may be a duplicate of the one shown at Fig. 2 and includes a shaft 85 that is connected to be driven by flexible shaft drive 3|, Fig. 1. A bevel pinion 86 is fixed to shaft 85 and meshes with another pinion 81, fixed upon shaft 88 journaled in

bearings

89 and 90 carried by the casing 9|. A worm 92 is fixed to shaft 88 and drives a gear 93 pivotally mounted upon a, shaft 94. An eccentric 95 is fixed to gear 93 and engages a bearing in one end of a link 96 having its other end pivotally connected at 96' With a link 91. The

entral portion of link 91 has pivotal connection as at |0| with a rod 69 guided for reciprocation in an aperture 99 formed in guide block |00. This block is attached to casing 9|. It will be understood that rod 69 is translated in an amount and direction in proportion to the rate and direction of elevation (or depression) of the gun in the same manner as rod 69, Fig. 2, is translated for rate and direction of train.

At its other end, remote from link 96, link 91 is slotted, as at |02, to engage a pin |03 carried by the end of slidable rod |04 that, in turn, is connected with the core of flexible drive cable 42. It has previously been explained that this cable leads to the multiplier 34, subsequently described.

The thro-w or offset of eccentric 95 depends upon the constants of the instrument and is selected and so related to the gun that, when the gun is horizontal, the connected end of link 91 will be displaced to its maximum extent. As the gun is elevated, gear 93 is rotated by a like angle and the displacement of link 91 is reduced in ac-I cordance with the cosine of the angle of gun elevation in the manner necessary for super-elevation. Thus, when the gun is elevated 90, the super-elevation correction is reduced to zero. The connections just described and including link 91 will be recognized as simulating, a simple nomographic chart. Assuming that the perpendicular distance between the axes of rods 69 and |04 is equal to the distance from the axis of rod 69 to pivot 96', it is necessary only to make the scalar value of each unit of super-elevation, say 1, twice the corresponding scalar value of a unit of lead due to angular rate, and to so connect the parts, that, for example, deflection of rod 69' to the left from zero or mid position corresponds to positive lead, while increasing values of superelevation cause deflection of pivot 96' to the right. The linear deflection of rod |04 is then the algebraio sum of the deflections introduced by the rate and super-elevation adjustments, namely, total vertical lead.

To resume, the train rate device 22 consists solely of the parts shown at Fig. 2, and its shaft 69 is connected directly to flexible drive 33 while its shaft 53 is driven by direct connection with flexible shaft 2|, Fig. 1. On the other hand, the elevation rate device 32, is driven by direct connection of its shaft (corresponding to shaft 53, Fig. 2), with flexible shaft 3|, Fig. 1, and consists of a rate mechanism exactly as shown in Fig. 2, plus the parts 86 to |04, Fig. 3. Thus the total translation of rod |04 is a true measure of total lead in elevation.

The range multiplier The mechanisms for multiplying the individual train and elevation rates by time of flight or range are shown at Figs. 6 and 7; and it will be noted from Fig. '1, that the two are mounted side by side so that, if desired, their adjusting levers may be operated as a unit. A frame |91 has a base providing aligned bores |08 and |09 within which a rod ||0 is slidably mounted. Bore |08 is of a diameter suicient to accommodate an abutment Washer III, constrained to movement with rod H0 by collars l2 and I3, pinned to the rod. Compression springs 4 and ||5 surround rod l0 and abut at one end against opposite sides of washer |I| and at their other ends against abutments provided by the frame and a nut ||6 that serves to connect flexible drive 42 to shaft Shaft ||0 may be conveniently formed in two sections, threaded into a coupling ||1 of generally rectangular form and having a central slot ||8 into which one end of a lever ||9 projects where it is pivotally connected to coupling |1 by a pin |20. As shown at Fig. 7, the lever ||9 is forked to form parallel arms, each of which is slotted, as at I2I and |22 to form parallel guideways Within which slides a crosshead |23. This crosshead is pivotally connected with a rod or rack |24 that is slidably guided within aligned bores |25 and |26, in frame |01. Rack |24 drives Aa pinion |21 that is directly connected to exible shaft 43 driving one side of differential 4 I.

An adjustable fulcrum is provided for lever |9, in the form of a crosshead |28 slidably guided by slots |2I and |22 and pivotally connected with a range slide |29 by means of a pin |30. Slide |29 is mounted for reciprocation in a direction normal to the direction of translation of rack |24 and rod ||0, by means of a guideway |3| formed in frame |01. Slide |29 has a pin |31 at its top. An adjusting lever |33 is pivoted at |34 to an upstanding portion |35 of frame |01 and has therein a radial slot |32. Range slide |29 projects through a slot |36 in lever |33 and is connected thereto by pin |31 riding in slot A sector |39 is attached to frame |01,

ltion of Fig, 6.

concentric of pivot |34. The periphery of this sector is provided with a range scale |40.

In operation, lever |33 is pivoted until its pointer |38 indicates the range of the target. This adjustment operates to move the fulcrum pin |30 for lever I9, to the proper position for that range and to thus vary the amount by which a given translation of rod I0, will translate rod |24 and rotate shaft |43', as will be obvious from inspec- Thus, the rotation of shaft 43 will be proportional to the algebraic sum of the super- 'elevation and elevation rate lead angles, multiplied by range, in short, proportional to the amount by which the line of sight should be elevated or depressed relatively to the gun bore.

It will be noted from Fig. 7 that the range multiplier for lead in train, is mounted sideby-side with the elevation lead multiplier and that the construction thereof is a duplicate of the construction described in the immediately preceding paragraphs. The parts of this multiplier have been given the same reference numerals, primed, as are used in connection with the elevation rate multiplier. In view of the duplicate constructions it is thought that the previous description will suffice. It will be understood that pin |29 is translated by drive shaft 33, Fig. 1, and that its rack |24 rotates a pinion, corresponding to pinion |21, that, in turn rotates flexible drive shaft' 35. Levers |33 and |33 may be moved individually to make any necessary spot corrections during ring.

Operation As base |2 is rotated to train the gun, pinion 26 is rotated at a rate proportional thereto. This rate is conveyed to device 22, and there measured as a proportional translation of shaft 69 which is conveyed to multiplier 34. The output of the multiplier appears as a rotation of flexible shaft 35 and is applied to sight 36 by worm 40 to impart the proper angular relation between the line of sight and the gun bore in the slant plane of the bore. Similarly, as the gun is elevated or depressed, to maintain the line of sight upon the moving target, rotation corresponding to the elevation rate, is imparted to gear 24 and is conveyed by way of flexible shaft 26, gear 21, pinion 30 and flexible shaft 3|, to shaft 85 of elevation rate device 32. This rate appears as a proportional translation of rod 69. By proper initial calibration and adjustment shaft 85 effects rotation of gear 93 and eccentric 95 in synchronism with the elevation of the gun, so that a radius connecting the axes of gear 93 and eccentric 95 moves from the full correction position corresponding to Zero quadrant elevation of the gun, through an angle of 90, to zero correction position, as the gun elevates to a vertical position. These adjustments are algebraically added, as has been previously described, and the result conveyed over flexible drive 42 to multiplier 34, where the range factor is introduced and the product appears as a rotation of flexible shaft 43 and is thereby conveyed to one side of differential. 4|. As the other side of said diiferential is rotated proportional to actual gun elevation above datum, the center of the differential is rotated proportional to gun elevation plus or minus correct elevation lead. This combined value is then conveyed to rotate the sight relatively to the gun by the correct amount, by way of flexible shaft 44 and worm 45, as previously described. Thus the only adjustment necessary is for range, and this value may be introduced by simultaneously ad- 8 justing both levers |33 and |33'. The action is smooth and continuous so that the gun bore is at all times maintained at the correct angle relatively to the line of sight, to hit the target.

Sight modification One suitable type of sight has been shown and described in connection with Fig. 1. Another type is shown at Figs. 8 and 9 wherein the sight may be adjusted by linkage directly connected to ilexible drives. In these gures a base |40 may be mounted directly upon the gun cradle |4, or may be carried by casing 28, as in Fig. l. A sight support |4| is pivoted upon base |40 on a vertical axis y, as by means of a circular projection |42 secured to, or integral with, support |4|. Said support carries upstanding arms |43 and |44, each being apertured, as at |45 to provide bearings for trunnions |46 and |41 secured to the casing |48 of a sighting device of any suitable type. Support |4| has a forked portion |49 radially offset from axis y-y and to which one end of a link |50 is pivoted. The other end of link |50 is pivotally connected with an eye bolt |5| adjustably connected, as by turnbuckle |52, to the adjacent end of a flexible drive or Bowden cable |53. This cable corresponds in function to exible shaft 35, Fig. 1, except only that its core, or driving element, moves axially relatively to the sheathing, instead of rotating relatively thereto. To use this type of cable, pinion |21, Fig. 6, may be omitted and the adjacent end of the cable directly connected to the projecting end of slide |24. Thus the sight is pivoted about the Y-axis, by an amount proportional to the output oi the train section of multiplier 34.

Upon translation of the core of cable |19 by the drivel from the elevation section of multiplier 34, bell crank |65 is pivoted to thereby reciprocate rod |63, pivot lever |55 and move sight |48 about its trunnions |46, |41, by the correct angle of lead in elevation. As in the case of cable |53, the drive from the elevation rate section of multiplier 34, may be effected merely by connecting the adjacent end of its core directly to the end of rod |24', Fig. 7. The pinion corresponding to |21 of the train multiplier can then be omitted.

It will be noted that drives |83 and |89 correspond to and are operated similarly to, drives |53 and |10 of Figs. 8 and 9, so that the correct angular adjustment is at all times applied to the sight. In those cases where the sight is mounted directly upon the gun cradle, differential 4|, Fig. 1, may be dispensed with, and drive 43 may then be connected directly to the sight.

For the purpose of complying with the requirements of the patent statutes, the invention has been described in connection with a particular and special use, namely, the directing of a gun in firing upon a moving target. However, it will be appreciated that it is not so limited but that the elements of the invention are useful individually and in combination where it is desired to indicate or determine rates of rotation or translation or to combine such rates With other variables, either where said rotation takes place continuously in one direction or where it takes place in either direction. Hence I do not wish to be limited to the precise details of construction shown, nor to the particular combination disclosed. Numerous modifications and substitutions of equivalents will occur or be obvious to those skilled in this art. I therefore wish to reserve all such changes, modifications, and substitutions of equivalents as fall within the scope of the subjoined claims.

Having now fully disclosed my invention, what I claim as new and desire to secure by U. S. Letters Patent is:

1. In a rate mechanism for gun-fire control, a shaft operated by and in proportion to the elevation rate and elevation position of a gun, a rod, governor means driven by said shaft and connected to positively shift said rod in each of two opposite directions for a corresponding direction of rotation of said shaft, superelevation cam means connected to be directly adjusted by said shaft in accordance with the cosine of the angle of gun elevation, a linkage algebraically adding the shifting of said rod and the adjustment of said cam means, and output means operated by said linkage.

2. In a rate responsive mechanism for a gun movable in elevation, apairpgovernors, means operating one governor by elevation of said gun and at a rate proportional to the rate of elevation, means operating the other governor by depression of said gun and at a rate proportional to the rate of depression, a rod connected to be moved in respective opposite directions by said governors, a superelevation cam connected to be moved proportional to the elevation angle of said gun, and output means operated jointly by said rod and cam in accordance with the algebraic sum of the movements thereof.

3. In a rate responsive mechanism for a gun movable in elevation, a pair of governors, means operaing the governors by and in response to the rate of elevation and depression, respectivelyy of 5 said gun, a rod connected to be shifted in one direction by one governor in proportion to the rate of actuation thereof and in the opposite direction by the other governor in proportion to the rate of actuation thereof, a link pivoted adjacent its central portion on said rod, means shifting one end of said link by and in accordance with the angle of gun elevation, and means driven by the other end of said link in accordance with the sum of the movements of said rod and shifting means.

4. In combination with a gun movable in elevation about a normally horizontal axis, a shaft rotated by and at a rate proportional to the rate of elevation of said gun, a first governor driven by one direction of rotation of said shaft, a second governor driven by rotation in the other direction of said shaft, said directions corresponding to elevation and depression of said gun, respectively, first means connected to be shifted in one direction by said rst governor only and in the other direction by the second governor only, a superelevation cam shifted by and in accordance with the angle of gun elevation, second means operated in response to the sum of the shifting of said rst means and cam, and third means adjustable in accordance with the range of a target and having an input driven by said second means and an output driven in proportion to said input multiplied by range.

5. In a gun sight, a base, a support mounted on said base for pivotal movement about a first axis, a line of sight device pivoted in said support for movement about a second axis normal to said iirst axis and determining a line of sight normal to said second axis, said line of sight and said axes being concurrent, a rod slidable axially on said base along said rst axis, a lever pivoted on said support on an axis parallel to said second axis, and connected at one end to said rod and at the other end to said device, means pivoting said support in accordance with one lead angle of said gun, and means sliding said rod in accordance with a second lead angle of said gun.

JOHN H. HOLSTEIN.

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

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