US2581401A - Torpedo director - Google Patents

Description

Jan. 8, 1952 R. M. FREEMAN 2,531,401

TORPEDO DIRECTOR Filed April 1, 1946 8 Sheets-Sheet 1 %9m @zemaw INVENTOR ATTORNEY Jan. 8, 1952 FREEMAN 2,581,401

TORFEDO DIRECTOR Filed April 1, 1946 8 Sheets-Sheet 2 INVENTOR ATTORN EY J 1952 R. M. FREEMAN 2,581,401

TORPEDQ DIRECTOR 8 Sheets-Sheet 4 Filed April 1, 1946 203 L L W /6 INVENTOR BY whim/u! //4 ATTORNEY Jan. 8, 1952 Filed April 1,

TORPEDO DIRECTOR 1946 8 Sheets-Sheet 6 INVENTOR ATTORNEY Jan. 8, 1952 FREEMAN 2,581,401

TORPEDO DIRECTOR JH/UE/YVM ROBERT M. FREEMAN R. M. FREEMAN TORPEDO DIRECTOR Jan. 8, 1952 8 Sheets-Sheet 8 Filed April 1, 1946 orqot Speed grwwvvbo'v ROBERT M. FREEMAN Patented Jan. 8, 1952 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 4 Claims.

The present invention relates to torpedo directors and, in particular, to such directors adapted for use in aircraft.

This application is a continuation-in-part of my abandoned application Serial No. 516,183, filed December 30, 1943.

Up to the present time in torpedo directors, the solution of the vector triangle known as the torpedo triangle has been accomplished on some form of angle solvers. Into the torpedo directors must be introduced torpedo speed. target speed, and target angle, which is the angle between the target's course and its line of sight from the firing plane at the instant of release. Several disadvantages are inherent in the methods now used. The pilot operating the torpedo director must estimate the target angle at which he wishes to drop the torpedo and set this target angle on the director. He must also estimate the targets speed and place this into the director, the torpedo speed being known in advance. In order to secure a hit, it is necessary that the plane using these directors be at the proper target angle relative to the target ship at the instant of drop. If, because of anti-aircraft fire or other circumstances beyond the control of the pilot, the firing plane is unable to reach this predetermined target angle, or if the pilot makes a mistake in estimating the target angle, a miss will result.

The present gyro-controlled instruments for determining the correct firing angle have been used with excellent results on surface and submersible water craft, and the accurate setting of these instruments is possible due to the low rate of speed at which the surface and submersible craft travel, thereby affording the operator considerable time to make numerous mathematical calculations, the results of which may then be set into the mechanism. Due to the high rates of speed, of such craft as dive bombers and other torpedo launching aircraft, the existing instruments are not adaptable to such craft, which travel at an exceedingly high rate of speed. With the innovation of aircraft torpedo dive bombing, an urgent need for a gyro controlled firing sight confronted the designers, one that would require a minimum of adjustment and the elimination of the usual time consuming mathematical calculations and adjustments, and an instrument that would enable the pilot of such aircraft to first set his sights at the desired firing angle preliminary to making his bomb run while traveling at a high rate of speed and, secondly, to make corrections for change in direction or speed of target, should the target change its course or 2 speed after the pilot had started his bomb run, at split second intervals.

It is an object of the present invention to provide in a mechanism havinga minimum of parts conveniently arranged, adjustments that will accurately determine the correct angle of the sights, of a torpedo firing sight adapted to be controlled by the usual airplane directional gyro while the airplane is traveling at a high rate of speed.

Another object of the present invention is the provision of a gyro controlled torpedo firing sight having a model target adapted to be adjusted into visible alignment with the object target, to properly and accurately continuously adjust the angle of the firing sight, after the proper adjustments have been set into the device.

A further object of the present invention is the provision of a torpedo director into which the target angle is continuously and automatically introduced by stabilizing in azimuth that portion of the torpedo triangle known as the target course and speed vector.

A further object of the present invention is the provision of a torpedo director that is instantly adjustable to compensate for variations in average torpedo speed for any particular conditions taking into account its airborne travel as affected by a last minute change in altitude at which it is to be dropped, for variations in aircraft speed, torpedo run or target course and speed.

A further object of the present invention is the provision of means carried by the firing sight for holding the firing sight in engagement with a. gyroscope, when the gyroscope is in uncaged position, to stabilize the target vector with respect to the target course within reasonable maneuvers of the firing plane.

A further object of the present invention is the provision of means for adjusting the rear sight in accordance with target speed, predetermined torpedo run, aircraft speed and altitude at time of firing, either in a caged or uncaged position.

A further object is to provide a torpedo director in combination with a modified directional gyro wherein a front and rear sight are mounted on vertical axes spaced in accordance with the water speed of the torpedo to be fired, the rear sight ball being mounted at the top of one arm of a bell crank lever having a horizontal pivot mounted for rotation about the vertical axis of the rear sight, the other arm of said bell crank lever extending approximately at right angles to said first arm and being operated by a vertically adjustable member rotatable with said rear sight, a visible ship model mounted on said rear sight normally to said horizontal pivot and rotatable therewith, means for stabilizing said rear sight by means of said gyro and means for vertically adjusting the vertically adjustable element in accordance with the target speed, air speed, torpedo run and altitude so as to position the rear sight ball at the proper point to complete the firing triangle with respect to the horizontal line between the axes of the front and rear sights.

Other objects and advantages will become apparent as the description proceeds and is taken in connection with the accompanying drawings wherein like characters of reference designate coresponding parts throughout the several views. and wherein:

Fig. 1 is a front elevational view in perspective of a torpedo director with cover removed and showing the director associated with a modified directional gyroscope, the solid line circle indicating the path of the rear sight in its sighting movement in either direction as indicated by the arrows, the dotted and dot-and-dash lines and arrows indicating the circles described when the rear sight arm is in two other positions of angular adjustment.

Fig. 2 is a side elevational view 01 the torpedo director and gyroscope, the cover bein shown in place.

Fig. 3 is a top plan view of Fig. 1.

Fig. 4 is a front elevational view of the torpedo director and gyro mounting post.

Fig. 5 is a partial vertical sectional view through the mounting post and the torpedo director.

Fig. 6 is a partial rear sectional View through the mounting post and the torpedo director.

Fig. 7 is a front elevational view of the director.

portions being shown broken and fragmentary,

the quadrant being removed and illustrating bores in the rear face, the broken section illustrating one of the brake shoes.

Fig. 8 is a space picture showin a triangular slice of the ocean and the triangular relations of the target run, the torpedo run and the range of release in an illustrative example of torpedo firing problems.

Fig. 9 shows the corresponding model triangle in a horizontal plane showing the relations of the corrected target speed, torpedo water speed and the line of sight.

Fig. 10 is an isometric view of the automatic computing mechanism for positioning the rear s ght ball in the proper relation with respect to the axes of the front and rear sights to continuously position the three vertices of the firing triangle with respect to the aircraft.

Fig. 11 illustrates a closure cap used for covering the opening in the top of the gyroscope housing when the director is removed therefrom.

The torpedo director, shown in Fig. 1, is a mechanical instrument which gives the torpedo pilot a means for finding the course on which he should release. To do this it receives estimates of target course and speed, as well as information to correct for the airborne torpedo run, and provides continually a computed line of sight. If the aircraft is so maneuvered that this line of sight passes through the target, then the lead is correct and release may occur. During such maneuvers it is normally unnecessary to correct the setting of target course, since this setting is automatically stabilized" and is unaffected by reasonable motion of the aircraft. M

The instrument attaches to a modified directional gyro I0, when the latter is available in an appropriate position, and draws from that instrument the stability-in-azimuth required to store the target course, once estimated. Connection to the gyro, in its installed position, is made by means of a bayonet joint and an adaptor l2 built on the gyro case. A manual clutch 88 is provided, which, when disengaged, severs completely the operative connection between director and gyro gmbal.

The computed line of sight (the output" of the director) is determined by the relative position of a ball-and-post combination atop the instrument.

In the operation of the torpedo director, the following instructions are meant merely to suggest a workable sequence of operations in the use of the director. They should not be interpreted in any degree as tactical doctrine.

When an attack is to be made, the torpedo plane will be initially at some distance from the target and presumably the gyro will be in use as a directional indicator. The plastic dust cover 55 on the director should first be removed by a straight vertical lift, without allowing it to bump the sight members. The next step in the attack is to throw the clutch lever 88 (see Fig. 1) all the way to the left. The gyro should next be caged by pushing knob i I in.

The speed and course of the target, if available. may next be incorporated. Target speed is set directly on the right-hand dial by means of knob (99. The target course is set by rotatin the gyro caging knob II while pushed in, until the ship model is aligned parallel with the target, and with the same heading. The gyro is then immediately uncaged by pulling knob i I out; and the course or heading of the target will automatically be stabil'zed. If, while preparing for the run, the target speed or course should differ from the values inserted, they may be reset with out interfering with any other settings.

It is advisable to determine in advance at What altitude the torpedo will be released, and to set the altitude dial (H) to that value as soon as possible. It is much easier to alter the values of torpedo run or airplane speed after the attack has been started, than it is to change the altitude setting. Altitude i set, by a pull-turn operation of the left-hand knob I53, against the index arrow of the altitude scale. Similarly, likely values of the torpedo run and airplane speed, for the moment of release, should be inserted, using the knob I83 to set the proper values on the corresponding scales I13 and I54 against one another.

The director with values set in and stabilized by the gyro is maintaining the course of the target. If the attack can be made as planned, the procedure is now simple. The target may be aligned with the sight ball and post merely by flying the plane in the appropriate direction. In the face of serious enemy resistance, the torpedo plane may be maneuvered in any necessary manner while approaching in a general way the desired release point. The director will still indicate the solution of the preset collision problem, whenever the sights align upon the target.

As the torpedo plane closes the range to reach the set value of the torpedo run, the set altitude and speed should be attained as quickly as possible. The course of the target may now be checked with the ship model and, if necessary, a

last adjustment may be made.

When the proper release point has been reached, the target should be lined up with the sights. The axis of the plane and hence the torpedo will then be directed toward the collision point, and the torpedo may be released.

The following is a condensed theoretical discussion of the conditions prerequisite for a torpedo hit. The distances covered, during the total time from release to collision, by the torpedo and a uniformly moving target are simply their speeds multiplied by that time. Hence the distances themselves are proportional to the correspond ing speeds. As seen in Fig. 8, where a triangular slice of ocean is shown, these same distances, together with the range along the line of sight at release, must form a triangle; and hence by the Law of Sines sin (Lead Angle) Target Run sin (Lead Angie) Target Speed sin iTarge t Anglej Torpedo sfid The torpedo may be said roughly to follow a fixed course, determined by the aircraft heading at release; but its speed is far from constant since its run is divided between air and water. for the torpedo speed an average value must be used, which may be derived from: torpedo water speed; aircraft speed and altitude (in horizontal flight); and torpedo run (for which range at release may, as a practical matter, generally be substituted). Conversion from torpedo water speed, which is a known property of the torpedo, to torpedo (average) speed may be made by dividing the first by a correction" Q, which involves principally the torpedo run and the aircraft speed and altitude at release. Instead of the last formula, then sin (head A r ;le) TargeiSpeedXQ The easiest way to solve this equation and to obtain the proper lead angle is to set up a model triangle in a horizontal plane, which will simulate the real triangle of Fig. 8 and in which the appropriate sides and angles will be in accord with the above formula. It is evident from the above formula that the torpedo water speed itself may be used as one side of this triangle if the side corresponding to target speed has been modified through multiplication by the correction Q described above. Such a model triangle is shown in Fig. 9, where the side corresponding to torpedo water speed is held in the direction of the aircraft, and the side corresponding to the (modified) target speed is aligned as the heading of the target. The similarity of the model triangle to the real space triangle, in spite of the interchange of the positions of corresponding sides, is evident from a comparison between Figs. 8 and 9. In particular, it is seen that the lead angle 5 is completely determined by this method.

Thus, it may be seen that a model speed-triangle can be used to solve the torpedo release problem. One side of the triangle is made proportional to the torpedo water speed and is fixed in the heading of the aircraft. Another side is made. proportional to the estimated target speed, corrected by a multiplier Q, and is set parallel to the target heading and stabilized. The third, or remainin side of the triangle provides a Thus 6 line of sight, which, if made to pass through the target by choosing the appropriate aircraft heading, automatically assures that that heading is satisfactory for release.

The correction Q compensates for the airborne run of the torpedo, and may be shown to be correctly accomplished through a fractional reduction in the length of the target speed vector. This fractional reduction must be directly pr portional to the square root of altitude, inversely proportional to the torpedo run, and directly proportional to the difference between airplane speed and torpedo water speed.

To show how the complete solution is carried out mechanically within the director, it is necessary to show how the primary information set into the instrument is utilized to produce the ultimate line of sight.

In Fig. 10, the target speed dial A rotates the pinion B which moves the plate C by an amount corresponding to the uncorrected target speed. At the left-hand side of the plate C, a stack of dials D, for setting in altitude, airplane speed, and torpedo run, computes the fractional reduction mentioned above, and delivers it as a rotation to the cam plate E, the radius of whose cam slot at any point controls the slope of the cam-follower arm F pivoted to plate C. Bearing against the lower edge of this arm F is a pin G whose vertical position is a measure of the corrected target speed.

The position of pin G ultimately controls the vertical position of rotatable piston H and therefore also of a small overhanging platform I at the top of that piston. A small lever at I, rigidly attached to the bottom end of the ball boom M bears on the under side of this overhangin platform.

The ball boom M is independently pivoted on a horizontal axis attached to the stem J which sits in a socket in the gimbal of gyro L. By means of the clutch K, this friction connection between gyro and director stem may be severed.

As pin G rises or falls, due to the positioning imposed by rotation of the correction-cam E and of the target speed pinion B. the ball boom M will be forced by the platform at I to assume a position such that the horizontal displacementfrom the extended axis of the stem to the center of the sight ball represents the properly corrected target speed.

This target speed displacement, or vector. is positioned in space by caging and rotating the gyro with the clutch K engaged: the torpedo speed vector is represented in direction by the axis of the airplane and in amount by the distance between the sight post N and the zero position of the ball boom M which is the extended axis of the stem J).

The target speed vector and the torpedo speed vector have now been combined properly as shown by the triangle at O, and when the target is lined with the sights the axes of the airplane and torpedo are directed toward the collision point.

This torpedo director is used with a directional gyro which has been modified in such a way that a connection to the vertical gimbal may be eifect ed through the top of the gyro case as shown in Fig. 10. When made available as a standard directional instrument this gyro simply has a cover over the opening in the top of its case. An adaptor housing I2 forming the external part of a bayonet joint and carrying a pneumatic connection 208, replaces this cover when the gyro 7 is to be used with the torpedo director. A new gasket, supplied as part of the equipment, should be used whenever such a replacement is made.

To the gyro with adaptor housing may be fitted either the director equipment, as best seen in Fig. 2, or the replacement 094; ill, Fig. 11. A sponge rubber washer N5, shown in Figs. 2, 4, and 6, is placed around the neck N4 of the adaptor housing l2 in either case. The replacement cap 2 ll may be substituted for the director when the latter is not in use, and is inserted and held in the neck in the same way, by the pins 3| and Si on its shank ll" being slid into the cam slot 2H].

Whenever the director is connected to or disconnected from the gyro, that is to say whenever the bayonet joint is engaged or disengaged, it is recommended that the plastic dust cover 55 be placed on the director component for facility in handling. With regard to the dust cover a. word or two of caution is in order. Whenever the cover is placed on the director, the clutch lever 88 (see Fig. 1) should be thrown all the way to the right: to the "gyro free position. In attaching or removing the cover, care should be exercised so as not to strike the members of the sighting system.

Before attaching (detaching) the director component to (from) the gyro, by means of the bayonet joint, the target speed dial I98 (Fig. 1) should be set at 40 knots. Be sure, also, that the clutch lever is in its extreme right position. Attach the director to the gyro by inserting the bayonet joint into the adaptor housing in such a. way that the bayonet pins enter the corresponding slots in the housing. Push down firm- 1y, turn clockwise, and release. To detach the director, push down, turn counterclockwise, and pull straight up.

Dust and dirt are the principal enemies of the director; the plastic dust cover should always be clipped to the director when the latter is not in use. When the director is removed from the gyro, the gyro should be covered to prevent entry of dust and dirt through the bayonet joint; and the replacement cap 2" (with sponge rubber washer 2 l5) should be kept in the adaptor on the gyro.

As to the eifect of the director on the performance of the gyro, it should first be remarked that there is no physical connection between the two when the clutch lever 88 (Fig. l) is thrown to the right. Even with the director clutched in, clutch lever to the left, it should be next to impossible to observe any loading of the gyro. With the director thus stabilized, it should be possible to make at least two complete 2-minute turns without causing excess drift of the gyro card. If a director loads the gyro appreciably it is mechanically in disrepair and should not be used.

Going back to the construction of the mechanism for reproducing the model triangle in the director, and referring to Fig. 9, the shape and cooperation of the adjusting parts is based on the following considerations. As already briefly explained, the equation of the actual speed triangle may be written sin 6 8 also assumed that the rated water speed or the torpedo is attained instantly upon entering the water, and is maintained throughout the remainder of the run.

In the model triangle the distance between the axes of the front and rear sights is fixed in accordance with the torpedo water speed, and to make corrections for the airborne travel of the torpedo to arrive at the proper line of sight, a correction factor may be applied to the target speed vector instead of the torpedo speed vector according to the following calculations:

The torpedo run KR=VtaT=VaTI+Vt(TT1) (2) where K is a constant to reconcile the units, T is the total time for torpedo run, T1 the time for airborne torpedo run (time of flight through the air), V1; is the torpedo water speed, and Va is the airplane ground speed.

From (2):

Transposing the first terms on each side of the equation and dividing through by (-KR): H wr KR KR KR Substituting (vtaT) for KR in the left side of the equation and simplifying:

Or, since the time of flight of the torpedo T1 is merely the fall-time from altitude H,

'FI T a then, from (3):

Multiplying the right hand side of Equation 1 by 1/17 E ma-v,

V, V, 8111 Via So that if a fictitious "corrected" target speed sin a /5 I m( C) IQ is inserted for target speed in (1). then the average torpedo speed Val may be replaced by torpedo water speed Vt.

In the airborne correction dials of the mechanism, only H, R, Va are set in, Vt as already mentioned is a constant of the apparatus and is set for 40 knots in the device shown.

Referring now to the drawings, the numeral In represents a modified directional gyroscope having a knob ll connected in a standard manner to cage and uncage the gyro by a push-pull motlon, and to adjust the gym in azimuth when caged, by a. turning motion. The numeral 12 designates a mounting post, and it a. torpedo director. The mounting post I2 is secured to the gyroscope I9 by screws I4 shown in dotted lines in Fig. 2 of the drawings. Interposed between the top of the gyroscope casing I5 and the mounting post I2 is a gasket I9.

The torpedo director I3 comprises a cylindrical housing member I! in which is mounted certain operating mechanisms to be enumerated and described in detail hereinafter. The housing member I1 has reduced portion I8 and an integral flange I9. In the wall of the cylinder H at 29 there is provided an opening in the form of a cam slot 2|, the lower wall 22 of the cam slot 2| being disposed at an angle and of irregular configuration and having recesses 23 and 24 for a purpose to be later described. Adjacent the top or the cylinder IT, in the wall of the reduced portion I9 is a slot 25 that receives an adjustable stop 25 having a threaded shank 2'! that is engaged by a nut 28 that secures the stop in an adjusted fixed position, and diametrically opposite the slot 25 is a slot 29. The lower portion 39 of the cylinder I1 is provided with studs 3| that may be integral with the wall of the cylinder or, as shown in Fig. 5, they may be threaded into the wall of the cylinder.

Mounted upon the flange I9 is a plate 32 of substantially triangular configuration that is provided with a central opening 33 and of a diameter to snugly engage the peripheral wall 34 of the housing H. The plate 32 is fixedly secured to the flange I9 by screws or rivets 35. Upon the plate 32 and secured thereto by any suitable means is a bar member 39 having a track-way groove 3! and an oblong opening 39. Adjacent the apex 39 of the plate 32, there are provided apertures 4| and 49 that receive respectively a lug 42 and a screw threaded shank 43 that depend from a block 44 as indicated by dotted lines in Figs. 2 and 5. The block 44 is rigidly secured to the plate 32 by a nut 45 that engages the threaded shank 43. superposed upon the block 44 and secured thereto by any suitable means is a tapered front sight post 45, a portion of the base of the post being approximately uniplanar with the wall 41 of the block 44. The tapered portion of the front sight extends to a point represented by the numeral 49 and at this point the post is of a reduced size and of a uniform diameter at 49, and may be of any suitable length, the portion 59 being provided with a white sight line 5| and a companion line diametrically opposite the line 5I. On the plate 32 adjacent one side wall of the block 44 there is provided numerical indicia 52 for a purpose to be later described. The plate is also provided with studs 53 and an indicia plate 54, the studs engaging clips (not shown) that are secured to the inner walls of a protective translucent cover 55 shown in Fig. 2 of the drawings.

Mounted for slidable movement within the housing IT is a sleeve 56 having a restricted portion 51, a bore 59 and enlarged end portions 59 and 69. The restricted portion 51 is provided with an opening 6! for a purpose to be later described. The end portion 59 is provided with a bore 62 of greater diameter than the bore 59, to form a seat 63. In the wall of the end portion 59 is a threaded aperture 54 that receives the threaded end 55 of a pin 66. Diametrically opposite the threaded aperture 64 is a slot 81 that houses the head of the adjustable stop 29. The end portion 59 has a reduced portion 99 and within the walls of the reduced portion 59 there are provided vent bores 19. The 'outerdiameter 10 of the portion 99 being of smaller diameter than the remainder of portion 59, a space H is formed between the inner wall of the reduced portion I9 and the outer wall of the reduced portion 99. A race of bearing I4 is received fixedly in the bore 52.

Mounted for slidable reciprocating movement in the bore 58 of the sleeve 56 is a cylindrical member 15 having a head 16, a bore 11 in the head, a hollow portion 18, a wall I9 having a bore 99, and a diametrical slot 99 for passing the pin 89", the lower end of the cylinder being provided with a flange Ill. The mouth of a bore 13 receives a closure cap 82 having a flange 83 and a recess 94, the flange 93 engaging the flange 8I of the cylindrical member I5. In the head I5 there is provided a threaded bore that receives the threaded shank B6 of a lever arm 81, the opposite end of the arm being provided with a knob 98 that is secured to the arm by a screw 99. Within the end portion 99 is a spring 99 that encompasses the cylindrical member I5, one end of the spring engaging the seat 12, the opposite end of the spring engaging the inner face of the flange 9|.

Within the sleeve 15 there is mounted a tubular member 9| having an upper portion 92 and a lower portion 93. The upper portion 92 is provided with a slot 94 and a triangular shaped flange 95, a half portion of the tubular member diametrically opposite the slot 94 being cut away. The tubular member has an annulus 99, the lower face of which rests on the top face of the bearing 14. The portion 9| of the tubular member is encompassed by the race of bearing I4, the reduced portion 93 passing through the bore 11 and terminating adjacent the lower wall of the head I9 and it is to be noted that the bore I! is of greater diameter than the reduced portion 93. In the upper bore 69 (see Fig. 5) there is positioned a retaining dust cap 99 having a bore I99 that engages the portion 92 of the member 9i. The cap 99 is provided with a recessed bore I9I that receives the annulus 96.

Within the tubular member 9| there is mounted for slidable movement a rod I92 that is provided with annuli I93, I94 and I95 (Fig. 6), the rod extending downwardly through the tubular member, the end I96 of the rod I92 terminating adjacent the wall 19. The lower portion I99 of the rod I92 is split as indicated by the numeral I97 and it is provided with an internal threaded portion I98 that receives the threaded portion I99 of a rod II9, that has an annulus III adapted for engagement with the wall 19, the rod II9 adapted for slidable movement through the aperture I I2 in the guide closure dust cap 92. The lower portion II3 of the rod H9 is of a reduced diameter, the end II4 having a tapered point. To the annulus I95 is mounted a U- shaped member II5 that is secured to the annulus by a screw II E as shown in Fig. 6, the U- shaped member having legs Ill and arms IIS, the legs being provided with an aperture I29. Interposed between the legs I I1 is a pivoted sight member I2I that comprises a base portion I22 in the form of an arm, the end of the arm terminating in a tongue I23 that is in engagement with the flange 95 of the tubular member 9|. Extend ing vertically from base portion I22 is a rod portion I23 that is provided with an aperture that receives a pivot pin I24, the pivot pin having reduced pintles I25 that engage the apertures I29 in the legs II! of the U-shaped member H5.

The movable sight I21 has an enlarged portion I26, a reduced upper portion that merges into a tapered portion I21, the end of the tapered 110,1 tion being provided with a sphere I28. Convoluted around the pivot pin I24 is a spring I29 having one leg I30 secured to the rod portion I23, the leg I3I being secured to one legof the U-shaped member at I32. A cover cap I33, having an internal diamter greater than the reduced portion I8 of cylindrical housing I1, is positioned over the tubular portion III of the member I1 and it is secured in place by a bolt I34 that passes through an aperture in the top of the cap I33 and is received in a threaded aperture in one of the arms I I9 of the U-shaped memher I I5. On the top face at the cover cap I33 is a block member I35 that is provided with a groove I35 in which groove is mounted a ship model I31. The cover cap I33 is provided with a diametrical slot I38 that is of a width greater than the diameter of the lower portion I26 of the sight I2I.

On the plate 32 and secured thereto by any suitable means is an L-shaped bracket I39 that is provided with a track-way groove I40 that is in spaced alignment with the 'groove 31. Mounted for slidable movement in the grooves 31 and I40 is a plate member I4I having a bearing I42 that may be integral with the plate member, the top of the plate member having a cut out portion I43 see Fig. 6) that engages the groove I40, the cut out portion terminating adjacent the ends of the plate, the projecting ends forming stops I44 and I45 for limiting the movement of the plate member I4I. To the plate member MI and held in spaced relation therefrom by a block I45 (see Fig. 3) is a plate member I41 having side Walls I48 and I49 that are approximately of semi-circular configuration and in which are mounted brake shoes I5I and I52. The front face of the plate I41 is provided with graduations I53 that are adjacent the side wall I40, and adjacent the graduations I53, is indicia I54 that read in knots from 100 to 250, and a letter V. The face is further provided with an arrow I55 that is adjacent the side wall I49.

Secured to the bar member 36 by screws I56 is a rack-bar plate I51. The slidable plate member MI is provided with an aperture I58 in which is rotatably mounted one end I59 of a tubular shaft member I60. The shaft I60 has a reduced portion IBI, a bore I62, an aperture I63 and a bore I54. Fixedly secured to the shaft portion I6I is a disc I65, the disc having a helical slot I66, and a pin I61 that is anchored in the disc I55 by any suitable means. Mounted on the shaft I60 and in spaced relation from the disc I65 is a dial I66 having an arcuate slot I69 through which the pin I61 passes. The dial I60 is further provided with a stud I10 and a circumferential groove I1I that is engaged by the brake shoes I5I. The face of the dial I56 is provided with graduations I12. the letter R standing for range" and an arrow for the altitude scale, and adjacent the graduations is indicia I13 that read in hundreds of yards from 8 to 24, i. e.. for values of R from 800 to 2400 yards. Within the bore I64 is a spring I14 that is held in the bore by a bolt screw I15, the head I16 of the bolt screw being housed in the bore I52 and it is to be noted the outer face of the head I15 of the bolt screw is normally coplanar With the end wall I11 of the shaft member I50. The end portion I10 of the bolt screw I15 passes through the aperture I19, the threaded portion I60 engaging a threaded aperture I 8| in a disc I02 that is secured to a slidable cap I03 in any suitable manner. The cap I83 has a m s kn b I II a semi-simm i t n '85 and a quadrant portion L06 that is provided with the letter H standing for "height, or altitude. The edge I81 of the dial I85 is provided with graduations I88 and with numerical indicia I89 that are read in hundreds of feet, the graduations being spaced for 8Q to 400. The rear face of the quadrant I05 is provided with recesses I90 that are adapted for engagement with the stud I10. To the rear face of the plate member I4I there is an arm I9I that is held to the plate for pivotal movement by a pivot I92, the lower fa e (if e am meeting t e i 6- he e: I9I is provided with a linger I93, and secured to are d posed. a ri ht a gle o th fing r is in I ha esses the. helica g oove I66 for a mi pose to be later described. In the bearing I42 is p at d asba '9 hat car i s. a g a 6 that engages teeth I91 of the rack bar plate I51. A dial I90 having a knob I99 is fixedly mounted on he sheit 1 .5.. th circemfe al edge of the disc havin IQOVc. it that receives the brake shoes I52. The front face of the dial is provided with s ad stions 2! and i d a m th t emprise t s al l br ted in knots of ta e speed from 0 to Q5.

The mounting post I2 comprises a body 203 in n nn lar collar 204 a d a bo e 5 the body 203 is a threaded bore 206 that is in communication with the bore 205, that receives the male threade shank 201. of a p pe 208, the op site end 209 of the pipe having internal threads (not shown) for connection to an air suction. line to. provide a flow of air into the gyro case for operating the gyro in a well known manner. The. collar 204 is provided with slots 2I0 having an L-.shaped portion 2 for the purpose of cooperating with the studs 3| on cylinder I1 to form a bayonet joint. In the bore 205 is positioned a. spring 212, the lower portion of the spring seating in a recess. 2I3, the upper portion of the spring engaging the. end wall 2I4 of the cylinder I1. Encircling the collar 204 is a sponge rubber gasket 2t5, the lower face of the gasket seating on thefacel I601? the body 203.

In the operation at the device, the torpedo die rector is mounted to the gyroscope in the follow ing manner, the lower portion 30 of the cylinder I1 is inserted into the. collar 204 of the mounting post I2, and duringtheinscrtion. the rodportion I I0 is received in a friction. grip bearing P in the. gyro gimbal Q, the. studs 3|. being positioned in vertical alignment with the. slots 2I0 in the collar. 204. When the studs are in alignment with the slots 2 I0. a downward push is exerted on the dust cover 55, this downward push compresses the. spring 2 I2 and. the selector at this point is turned clockwise until thefront of the plate 32 is parallel with the front of the gyroscope, the studs 3| engaging the notches in theends of the L-shaped portions 2 II of the slots H0, and the director assembly is held in this position by the spring 2| 2..

The lever knob 58 permits the use of the gyroscope as a directional indicator when the lever is pushed to the right, which is the gyroscope free position, as indicated on the plate 54, and this action lifts the end of pin H0 from contact with the grip bearing P in. the gyro gimbal. During the movement of the lever arm 81 the following action takes place, the arm 81 rides the inclined wall 22 of the cam slot 2| until it drops into the notched portion 24 as shown in Fig. 7 of the drawings. and the following action of the following parts takes place in the cylindrical member I1, the member 15 rotates upwardly and in a 13 spiral direction, bringing the wall I9 in contact with the annulus III thereby lifting the rod I02, U-shaped member II5, cap member I33 and rear sight member I2I. The movement of the above parts disengages the end II I of rod portion II3 from the friction bearing in the gyro gimbal.

When the lever knob 80 is pushed to the left, which is the gyro stabilized position as indicated on the plate 54, the director is connected to the gyroscope through the movement and contact of the following parts. The arm 01 rides the inclined wall 22 of the cam slot 2I and drops into the notched portion 23 during movement of the lever arm, the member I5 to which the arm 8'! is connected, spirally turns and moves downwardly through the action of the spring 90, the rods I02 and H being forced downwardly through the action of the spring I29 that forces the end lid of rod portion II3 into gripping relation with the friction bearing in the gyro gimbal.

As shown in the drawings, the setting dials are three in number, the two on the left I63 and I85 are in stacked relation with the disc I85 on the shaft I60, and these dials by adjustment relatively to each other and to the scale I54 on plate I41, are for setting the flight-constants to allow for the airborne travel of the torpedo, while the dial on the right I98 is for the target-speed setting dial.

The three airborne correction scales from in side out I89, I13 and I54 are for setting H, R and V; where:

H=altitude, in feet, of the torpedo at moment of release.

R=run, or future range, or slant range, or torpedo traverse; i. e., the actual horizontal air plus water travel of the torpedo between release and collision with the target.

Vg=the ground speed of the torpedo plane along the run, at the moment of release of the torpedo.

The H-scale is graduated in feet from 80 to 400 and is set to the index by pulling out the knurled knob I84 until the stud H0 is free from the apertures I90 and is free to rotate, and turning the knob until the proper altitude indicated on the scale I09 falls on the index or arrow point on the dial I68. When the knob is released, the scale will settle into position, and be locked to the dial I60 by one of the apertures I 90 engaging the stud I10.

For the R-scale or V; scale there is no index, these circles being set by setting the proper values opposite each other. As previously described, the R-scale is graduated in hundreds of yards, from 8 to 24, i. e., for values of R from 800 to 2400 yards. The V; scale is graduated in knots from 100 to 250.

For a torpedo launched at a distance of 1800 yards from the collision point, from a plane traveling at a ground speed of 200 knots, the 18 on the R-scale is set opposite the 200 of the V scale. In all directors, the V5 or target-speed dial is calibrated in knots from 0 to 45.

When an attack is to be made, the torpedo plane will presumably be at some distance from the prospective target and the gyroscope III will be in use as a directional indicator. The first step in the attack is to engage the director I2 with the gyroscope I0 by throwing the lever knob 80 to the left as far as it will go, this being the director stabilized position. The speed and course of the target must next be estimated, the

target-speed in knots is set on the VI dial I90,

the target course is set by rotating the gyroscope knob I I in pushed in or gyro-caged position until the ship model I31 on the dust cap I33 of the rear sight post I2I is aligned parallel with the target with the same heading. When the gyroscope I0 is uncaged by pulling knob I I out to uncage the gyro, the course and heading of the tar get will be stabilized by the gyro. If, during the course of the next few moments, while preparing for the run, the target speed or course should seem to have been incorrectly estimated, the director may be reset by use of the knob I I without interfering with any other settings being made. The altitude at which the torpedo is to be released is preferably planned in advance and the H-dial I set accordingly. It is much easier to alter the values of run or ground speed, after the run has been started, than to change the H- setting.

Likely values of the future range and ground speed, both for the moment of release, are next set by setting the proper values on the R and Vs scales opposite each other.

The director with values set in and stabilized by the gyroscope I0 is maintaining the direction and speed of the target. If the attack can be made as planned, the procedure is as follows: The actual target is aligned with the sights 49 and I2I by flying the plane in the proper direction. If enemy resistance becomes annoying, the torpedo plane may be flown any way deemed desirable, while approaching in a general way the desired release point; the director will continue to indicate the solution of the collision problem.

As the torpedo plane approaches the proper value of the future range, the pre-set altitude and ground speed should be attained as quickly as possible. The course of the target should be checked with the ship model I31 on the director. and, if necessary, a last adjustment of this variable should be made with the knob II by casing the gyro.

When the proper release-point has been reached the target must be lined up with the sights 49 and I2I, whereby the axis of the plane (and hence of the torpedo) will be directed toward the collision point; and the torpedo may then be released.

With the director in stabilized position, the rod III is in frictional contact axially with the gyro imbal and movement of the knob II in its gyro caged position in a clockwise or counterclockwise direction imparts turning movement to the following members, rod II 0, rod I02, U-shaped member II5, cap I33 and rear sight I2I, whereby the ship model I31 may be brought in parallel alignment with the target with the same heading, for the purpose described above.

Target speed in knots is set on the Vs dial I98 as follows: Assuming that the 0 on the dial I 98 is in line with the arrow V and that the dial IE8 is to be set for a 40 knot target speed. The dial is rotated in a clockwise direction until the numeral 40 is in line with the arrow V, and durin movement of the dial, the gear I96 on the shaft I is rotated and engages the teeth in the rack bar plate I51, imparting movement to the slidable plate member III, the plate with all the dials mounted on it moving to the right. The arm IOI that is pivotally mounted on the plate MI and disposed at an inclined angle, is in engagement with the pin 66 that is secured to the sleeve member 51, the sleeve member 51 being urged upwardly against the lower edge of arm I9I through the action of the spring 00.

As pin 98 is moved, sleeve 51 moves member 93, member 95 causin sight member I to move on its pivot I24 under the tension of the spring I29. Adjustment of the target speed setting thus adjusts the leverage of arm I9I acting on pin to affect the amount of displacement of the rear sight I23 by vertical movement of the pin I93 at the end of lever I9I as controlled by the helical slot, which is moved by the adjustments of knob I83.

The altitude at which the torpedo is to be released, when determined, is set on the H-dial. To do this the knob I83 is pulled outwardly and rotated either in a clockwise or counterclockwise direction until the determined number of feet in hundreds on the H-scale is in line with the arrow or index on disc IE8. By way of example. if the torpedo is to be released at 200 feet, the knob turned until the number 2 mark on the scale is in line with the arrow on dial I59, and

then released, whereupon the proper aperture I99 will slip over the pin I'Ifl to lock the dial in proper relative position.

In this setting the following operation takes place, as the knob I83 is pulled out, which is integral with the H-dial I85, one of the apertures I90 therein is disconnected from the pin IIIl on the dial I58. The H-dial is connected to the disc I65 by the pin I61 and as the H-dial I is rotated in either direction the disc IE5 is also rotated, thereby imparting movement to the arm I9I through the pin I94 that engages the helical groove I66, in the disc I65. This movement of the arm I9I effects. either an upward or down ward movement of the pin 66 carried by the cylinder 56 depending upon rotation of the H- dial I85. As the cylinder 56 moves up or down. rear sight I2I is moved either way from or toward a vertical position, the following members causing this movement; the tubular member 9I and its flange 95 carried by the cylindrical member 56, the portion I22 of the rear sight I2I which is held in contact with the flange 95 by the spring I29, thereby causing the rear sight I2I to move on its. pivot I24 as the pin 68 is raised or lowered.

For setting the knob I83 for the range between the release and collision with the target and the ground speed of the aircraft, the dials I95, I68 and disc I65 are in locked engagement. The dial I85 being locked to dial I98 through pin IIli carried by said dial and one of the apertures I in dial I85. Disc I65 is in locked engagement with dial I85 by the pin I61 carried by disc I65 passing through the arcuate slot its in dial I99, and

slidable in a registering aperture in dial I35.

Assuming the range to be 1860 yards and the ground speed of the aircraft to be 200 knots, the knob I83 is rotated until 18 on dial I68 opposite 200 on the V3 or groundspeed scale on plate I41. The movement, during this adjustment, of the dials I85, I68 and disc I65 as a unit affects the arm I9I, pin 66 and rear sight I2I in the same manner as previously described during the torpedo altitude setting but by an amount corresponding to the correction (Q) of the target speed vector to compensate for the airborne travel of the torpedo under the herein assumed conditions. As shown in Figs. 1 to '7, the front sight post in the position marked 1 at 52 on the base plate 39, is mounted at a distance from the rear sight axis representing the torpedo run vector of a torpedo having a water speed of 40 knots. ProvisiOn is made, however, for reversing the mounting of this front sight with respect to the two open- Inge I! and I in the base plate 39 by removing the post from the position shown and reinserting it so that the stud 43 goes through the opening GI and the pin 42 is in the opening 46. With the post mounted in this position which is indicated by the numeral 2 inscribed at 52 on the base plate 39, the distance between the front sight post and the axis of the rear sight is proportionately decreased to represent the shorter torpedo run vector corresponding to a torpedo having a water speed of 33.5 knots. These are the two standard torpedoes in general use. However, the front sight post may be made adjustable as to its distance from the rear sight axis so as to conform to any speed of torpedo, as indicated by the slidable mounting connection shown in Fig. 10.

The helical cam groove I66 on plate I65 is formed so as to move the lever I9I and therefore the pin 66 and shoulder and thereby also the rear sight ball I28 in accordance with the correction Q necessary to be applied to the target run which is represented by the horizontal distance between the sight ball and the vertical axis of the rear sight. As previously explained, the correction factor Q is directly proportional to the square root of the altitude, inversely proportional to the range or torpedo run, and directly proportional to the difference between the ground speed of the aircraft and the torpedo water speed. These proportions are properly scaled in the instrument with respect to the shape of the helical cam slot I66, the scale of values of the several scales used, and the representative distance between the axes of the front and rear sights, so that accurate results may be obtained in any positions of the adjustments.

It will be understood that the above description and accompanying drawings comprehend only the general and preferred embodiment of the invention and that various changes in construction, proportion and arrangement of the parts may be made within the scope of the appended claims without sacrificing any of the advantages of the invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. In a torpedo director for aircraft, a front sight post, a support rotatable on a vertical axis, a horizontal pivot mounted across the axis of said support, a rod pivotally supported at one end on said horizontal pivot and having a rear sight ball at its other end, means for adjusting said rod to vary the horizontal displacement o1v said ball relative to said vertical axis, means for adjusting the angular position of said rotatable support to vary the azimuth of said ball relative. to said vertical axis, and. a model target mounted for rotation with said horizontal pivot and headed in the direction of the azimuth of said ball.

2. The combination defined in claim 1, wherein said displacement adjusting means includes dialed knobs, and mechanical connections be. tween them and said rod for regulating said displacement in accordance with the estimated target speed, and said angle adjustingmeans comprises a gyroscope for automatically maintaining said displacement parallel to a. target course.

3. The combination defined in. claim 2, wherein said knobs include input means for correcting said displacement in accordance with the torpedo run as it may be afiected by the altitude of torpedo release, aircraft ground speed, and range.

4. In a torpedo director for aircraft, a front sight post, a support rotatable on a vertical axis. a. horizontal pivot mounted across the axis of said support, a rod pivotally supported at one end on said horizontal pivot and having a rear sight element at its other end, means for adjusting said rod to vary the horizontal displacement of said element relative to said vertical axis, means for adjusting the angular position of said rotatable support to vary the azimuth of said element relative to said vertical axis, said rod adjusting means including a plurality of dials, and mechanical connections between said dials and said rod for regulating the displacement of said element in accordance with estimated target speed.

ROBERT M. FREEMAN.

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

Number 5 Number 18 UNITED STATES PATENTS Name Date Inglis Nov. 29, 1927 Bates Mar. 6, 1928 Watson Jan. 16, 1934 LePrieur et a1. Apr. 9, 1935 Donitz Dec. 2, 1941 Klemperer et al. Sept. 4, 1945 James July 23, 19-16 Freeman 1- June 10, 1947 Halsey Apr. 6, 1948 Gallery Dec. 19, 1950 FOREIGN PATENTS Country Date Switzerland Oct, 16, 1941 Germany Sept. 22, 1919 Germany Sept. 30, 1936 France Dec. 12, 1941

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