US2421749A - Torpedo director - Google Patents

Torpedo director Download PDF

Info

Publication number
US2421749A
US2421749A US454295A US45429542A US2421749A US 2421749 A US2421749 A US 2421749A US 454295 A US454295 A US 454295A US 45429542 A US45429542 A US 45429542A US 2421749 A US2421749 A US 2421749A
Authority
US
United States
Prior art keywords
target
torpedo
shaft
arm
director
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US454295A
Inventor
Robert M Freeman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US454295A priority Critical patent/US2421749A/en
Application granted granted Critical
Publication of US2421749A publication Critical patent/US2421749A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41WEAPONS
    • F41GWEAPON SIGHTS; AIMING
    • F41G9/00Systems for controlling missiles or projectiles, not provided for elsewhere
    • F41G9/008Means for controlling firing of torpedoes; Torpedo directors

Definitions

  • the invention relates to improvements in torpedo directors for torpedo-carrying aircraft.
  • the solution of thevector triangle known as the torpedo triangle is accomplished on anangle solver.
  • torpedo speed, target speed and target angle which is the bearing'of the aircraft from the targets course at the 1nstant of release.
  • the pilot operating the torpedo director H lllstgestimatethatargetangleat which he wishes to drop the torpedo and set this target angle on the director. He must alsomehstimate the ships speed ⁇ and lce-"tliis"ihto the The" t'orpedspged is known in adthat the plane be at the proper target angle relative to the target ship at the instant of drop. If, because of antiaircraft fire or other circumstances beyond the control of the pilot, the ring plane is unable to reach this predetermined target angle, or if the pilot makes a mistake in estimating this target angle, a miss will result.
  • Another object of the invention is to provin'ade a torpedo dreeter.ietciuhih,.themtigle ⁇ isf"iitiiiisly andautorn ally vMinutiQluced by 'stabilizinein.azimutntha portion of the torpedo triangle known as'the target course and speed Vector.
  • a further object is the provision of a torpedo director vof the character described which is adjustable to compensate for Variations in torpedo speed, aircraft vspeed and altitude at the time the'torpedo is released.
  • a still further object is to provide a torpedo director of the character described which is adjustable for different target speeds.
  • drawing Figure 1 is a top plan view of the torpedo. director with its cover partly broken away to show enclosed parts, the relation between parts of the torpedo director and a torpedo triangle being diagrammatically illustrated,
  • Figures 2 and 3 are vertical sectional views through the torpedo director taken substantially on the lines 2-2 and 3-3, respectively, of Figure 1.
  • the numeral I5 generally designates the improved torpedo director which may be mounted in any suitable support, such asy a case I6 provided with a cover Il.
  • a bracket I 8 supporting a xed guide rod I9 and a rotatable threaded rod 20 provided with a knob 2I.
  • a bearing 22 Slidable along the rod I9 is a bearing 22 including an upright tube 23 and a sleeve 24 in threaded engagement with the rod 20.
  • Fixed transversely of the upper end of a vertical shaft 25 rotatably supported by the tube 23 is an elongate target sighting member 26 for alignment with the line of sight vector 2l of a torpedo triangle 28 including a real target, such as the ship diagrammatically shown at 29 in Figure 1.
  • a gyroscope 30 Mounted in the case I6 is a gyroscope 30 whose setting may be changed by means of the usual caging and setting knob 3I.
  • this knob is first pushed in, operating a device which cages the gyro while at the same time it meshes the bevelled gears whereby the gyro may be set in the desired position, and then the knob is pulled out to uncage the gyro in its new position relative to the artificial target.
  • the details of this mechanism are not shownv because they are well known. An example of these details may be seen, e. g., in the patent to Zand No. 1,946,657, Where the. .corresponding knob ⁇ is designated by numeral 20.
  • Patent Nos. 2,069,285 at 38 and 2,091,964 at 96 Fixed transversely of the upper end of a vertical shaft 32 connected to the gyroscope is an artificial target 33 to be disposed in paralleling relation to the target course and speed vector 34.
  • Motion transmitting means 35 are provided between the shafts 32 and 25 for disposing the target sighting member 26 ⁇ at an angle relative to the torpedo track and speed vector 36 of the torpedo triangle 28 depending on the angular setting o f the artificial target 33.
  • motion is transmitted by pulleys 31, 38 and belt 39 between the shaft 32 and a tubular shaft 4I] rotatable in a bracket 4 I.
  • Fixed transversely to the upper end of the tubular shaft 40 are parallel guide rods 42 slidably supporting an eccentric block 43..
  • pulleys 3l, 38 of equal size for transmitting motion between the shafts 32 and 40, the parallel relationship of the artificial target 32 to the guide rods 42, as shown in Figure 1, will be maintained 3 in all positions.
  • Fixed to the shaft 25 above the tube 23 is an arm 44 having its free end portion slidably extending through a sleeve 45 pivoted at 46 to the eccentric block 43.
  • Compensating means 50 are provided for ad- .iustlng the motion transmitting means 35 to correct for variations in target speed.
  • Extending through the tubular shaft 40 is a line 5
  • a contractile coil spring '55 connected to the eccentric block as by a line 155, will move the block outwardly along the guide rods 42.
  • may be adjusted to shift the target sight shaft 25 relative to the shaft 40 so that the throw of the arm 44 by the eccentric block 43 is varied.
  • the pilot of the aircraft adjusts the gyroscope 30 by rotating the knob 3l to bring the articial target 33 into parallel relation to the target ship 29.
  • the target speed knob 54 is set to conform with the estimated speed of the target.
  • the stabilized artificial target 33 will remain parallel to the target ship 29 regardless of changes in the course of the aircraft. Iftheraircraftisms/ouflown as to keepthesighting member 2ltrained-onthe tar-get, the aircraft will follow a Vcurved path that will make antiaircraft gunnery from the target more difficult.
  • the 'I'he torpedo may be dropped at any time that the aircraft is disposed at the proper lead angle 51 relative to the target 29, as indicated by alignment of the sighting member 26 with the target. Should the target change its course, the pilot of the aircraft merely resets the lead angle to the proper value by adjusting the gyroscope caging knob 3
  • a torpedo director comprising a firing sight mounted at one end on a horizontally adjustable vertical pivot, a horizontal arm mounted on a second vertical pivot aligned with said horizontal adjustable pivot and having a pivoted guide radially adjustable thereon, the other end of said firing sight being slidably connected in said guide, a vertically pivoted artificial target offset from said firing sight and adapted to be manually adjusted parallel with an objective target by eye, a belt connecting pulleys connected to said arm and said artificial target for maintaining parallel alignment therebetween andgyroscopic-means fori automatically stab'lizing he artificialtargetin ⁇ any/selectedng;
  • a torpedo director comprising a first shaft having an axial passageway, an arm carried by the rst shaft, an eccentric slidable on the arm, a line extending through the passageway and connected to the eccentric, a spool for reeling in and paying out the line, resilient means maintaining tension on the line; a second shaft, an arm carried by the second shaft and having its free end portion slidably connected to the eccentric; a third shaft, an artificial target carried by said shaft, pulleys on said first shaft and third shaft, a belt connecting said pulleys whereby movement of the third shaft moves the first shaft to maintain said target and arm in parallel alignment and moves the eccentric and the firing sight synchronously, and gyro,- scopic means maintainingmthe artificialtgtin 4.
  • a torpedo director comprising first, second, and third shafts, the first shaft carrying an arm, an eccentric connected to the free end of said arm, means for adjusting the distance between the first and second shafts in the direction of a torpedo discharge, a sight bar carried by the second shaft and slidable in said eccentric, pulleys on the first and third shafts, a belt connecting said pulleys, gyro stabilizing means for the first and third shafts to directionally stabilize said shafts, an artificial target carried by the third shaft, whereby movement of the third shaft synchronously moves said artificial target, sight bar, eccentric and arm.
  • a torpedo director comprising a firing sight mounted at one end on a horizontally adjustable vertical pivot and having its other end slidably connected in a pivoted guide, an arm having said guide radially adjustably mounted thereon and said arm having a vertical axis spaced forwardly from said vertical pivot in the direction of said horizontal adjustment, an artificial target mounted on a second vertical pivot to one side of the firing sight, an operating connection between said guide arm and said second vertical pivot for simultaneous turning movement to maintain parallel alignment between said artificial target and said arm, a.
  • directional stabilizing gyro means for directionally stabilizing the artificial target, equipped with manual setting means for said target operative to cage said gyro means during the setting operation whereby said artificial target, having been once set manually parallel to an actual target by eye, after the radial distance of the guide and the distance between said first vertical pivot and said arm axis have been set in accordance with the estimated target and torpedo speeds respectively, will maintain its parallel relationship to the actual target, so that upon mere sighting of the target after anyfur- Setlist litem ther maneuvers of the aircraft the torpedo may be sent on its proper course to score a hit.
  • a torpedo director comprising a ring sight mounted at one end on a horizontally adjustable vertical pivot, a vertically pivoted artificial target offset from said ring sight and accessible for manual alignment parallel with an observed target, a horizontal arm mounted on a second vertical pivot forwardly of said rst pivot and operatively connected to said artificial target for maintaining parallel alignment therewith, said arm having a pivoted guide radially adjustable thereon, the other end of said ring sight being slidably mounted in said guide, and means for directionally stabilizing said artificial target when once manually set parallel to an observed target, whereby automatic movement of said articial 6 target thereafter synchronously moves the firing sight angularly with respect to the fore and aft line between the first and second pivots to vary the angle of advance when sighting on the observed target in accordance with changes in the range of the observed target.

Description

33"'236. (w 2942ls749 SR June 10, 1947 R. M. FREEMAN l 2,421,749
TORPEDO DIRECTOR Filed Aug. 10, 1942 727429500 l 7 spez-a 714.24657' SPEED TARGET i-Fgs- 53 T DZ2-6- t [[7 y Hobart ree-mm f BY f/f/ fff'/ effector.
vance. In `order to secure a h1t, 1t lynecessary Patente-d June 10, 1947 UNITED STATESv PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 6 Claims.
The invention relates to improvements in torpedo directors for torpedo-carrying aircraft.
In existing torpedo directors, the solution of thevector triangle known as the torpedo triangle is accomplished on anangle solver. Into this device is introduced torpedo speed, target speed and target angle, which is the bearing'of the aircraft from the targets course at the 1nstant of release. The pilot operating the torpedo director H lllstgestimatethatargetangleat which he wishes to drop the torpedo and set this target angle on the director. He must alsomehstimate the ships speed `and lce-"tliis"ihto the The" t'orpedspged is known in adthat the plane be at the proper target angle relative to the target ship at the instant of drop. If, because of antiaircraft fire or other circumstances beyond the control of the pilot, the ring plane is unable to reach this predetermined target angle, or if the pilot makes a mistake in estimating this target angle, a miss will result.
It is an important object of the present invention to providev a torpedo director that continuously and automatically introduces the correct target angle in the director thereby giving the proper lead angle.
Another object of the invention is to provin'ade a torpedo dreeter.ietciuhih,.themtigle `isf"iitiiiisly andautorn ally vMinutiQluced by 'stabilizinein.azimutntha portion of the torpedo triangle known as'the target course and speed Vector.
A further object is the provision of a torpedo director vof the character described which is adjustable to compensate for Variations in torpedo speed, aircraft vspeed and altitude at the time the'torpedo is released.
A still further object is to provide a torpedo director of the character described which is adjustable for different target speeds.
Other objects and advantages of the invention will become apparent during the course of the following detailed description, taken in connection with the accompanying drawing, forming a part of this specication, and in which drawing Figure 1 is a top plan view of the torpedo. director with its cover partly broken away to show enclosed parts, the relation between parts of the torpedo director and a torpedo triangle being diagrammatically illustrated,
Figures 2 and 3 are vertical sectional views through the torpedo director taken substantially on the lines 2-2 and 3-3, respectively, of Figure 1.
In the drawing, which for the purpose of illustration shows only a preferred embodiment of the invention, and wherein similar reference characters denote corresponding parts throughout the several views, the numeral I5 generally designates the improved torpedo director which may be mounted in any suitable support, such asy a case I6 provided with a cover Il.
Disposed within the case I6 is a bracket I 8 supporting a xed guide rod I9 and a rotatable threaded rod 20 provided with a knob 2I. Slidable along the rod I9 is a bearing 22 including an upright tube 23 and a sleeve 24 in threaded engagement with the rod 20. Fixed transversely of the upper end of a vertical shaft 25 rotatably supported by the tube 23 is an elongate target sighting member 26 for alignment with the line of sight vector 2l of a torpedo triangle 28 including a real target, such as the ship diagrammatically shown at 29 in Figure 1.
Mounted in the case I6 is a gyroscope 30 whose setting may be changed by means of the usual caging and setting knob 3I. In operation, this knob is first pushed in, operating a device which cages the gyro while at the same time it meshes the bevelled gears whereby the gyro may be set in the desired position, and then the knob is pulled out to uncage the gyro in its new position relative to the artificial target. The details of this mechanism are not shownv because they are well known. An example of these details may be seen, e. g., in the patent to Zand No. 1,946,657, Where the. .corresponding knob` is designated by numeral 20. Devices of this type may also be seen in Patent Nos. 2,069,285 at 38 and 2,091,964 at 96. Fixed transversely of the upper end of a vertical shaft 32 connected to the gyroscope is an artificial target 33 to be disposed in paralleling relation to the target course and speed vector 34.
Motion transmitting means 35 are provided between the shafts 32 and 25 for disposing the target sighting member 26 `at an angle relative to the torpedo track and speed vector 36 of the torpedo triangle 28 depending on the angular setting o f the artificial target 33. In the example shown, motion is transmitted by pulleys 31, 38 and belt 39 between the shaft 32 and a tubular shaft 4I] rotatable in a bracket 4 I. Fixed transversely to the upper end of the tubular shaft 40 are parallel guide rods 42 slidably supporting an eccentric block 43.. By providing pulleys 3l, 38 of equal size for transmitting motion between the shafts 32 and 40, the parallel relationship of the artificial target 32 to the guide rods 42, as shown in Figure 1, will be maintained 3 in all positions. Fixed to the shaft 25 above the tube 23 is an arm 44 having its free end portion slidably extending through a sleeve 45 pivoted at 46 to the eccentric block 43.
Compensating means 50 are provided for ad- .iustlng the motion transmitting means 35 to correct for variations in target speed. Extending through the tubular shaft 40 is a line 5| having one end portion trained over a pulley 52 and attached to the block 43, the line I at its opposite end portion being wound on a spool 53 so that when the line is reeled in, as by rotation of knob 54, the eccentric block 43 will be moved radially inward along the guide rods 42. When the line 5l is paid out, a contractile coil spring '55 connected to the eccentric block as by a line 155, will move the block outwardly along the guide rods 42.
In order to compensate for variations in torpedo speed, aircraft speed and altitude at the time of drop, the knob 2| may be adjusted to shift the target sight shaft 25 relative to the shaft 40 so that the throw of the arm 44 by the eccentric block 43 is varied.
To operate the director, the pilot of the aircraft adjusts the gyroscope 30 by rotating the knob 3l to bring the articial target 33 into parallel relation to the target ship 29. The target speed knob 54 is set to conform with the estimated speed of the target. During the approach of the aircraft, the stabilized artificial target 33 will remain parallel to the target ship 29 regardless of changes in the course of the aircraft. Iftheraircraftisms/ouflown as to keepthesighting member 2ltrained-onthe tar-get, the aircraft will follow a Vcurved path that will make antiaircraft gunnery from the target more difficult. 'I'he torpedo may be dropped at any time that the aircraft is disposed at the proper lead angle 51 relative to the target 29, as indicated by alignment of the sighting member 26 with the target. Should the target change its course, the pilot of the aircraft merely resets the lead angle to the proper value by adjusting the gyroscope caging knob 3| so that the artificial target parallels the new course of the target.
Various changes may be made in the form of the several elements of the invention herein shown and described Without departing from the spirit and scope of the invention, as defined in the following claims.
The invention described herein may be manufactured and/or 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 I claim is:
l. In a torpedo carrying aircraft, a torpedo director comprising a firing sight mounted at one end on a horizontally adjustable vertical pivot, a horizontal arm mounted on a second vertical pivot aligned with said horizontal adjustable pivot and having a pivoted guide radially adjustable thereon, the other end of said firing sight being slidably connected in said guide, a vertically pivoted artificial target offset from said firing sight and adapted to be manually adjusted parallel with an objective target by eye, a belt connecting pulleys connected to said arm and said artificial target for maintaining parallel alignment therebetween andgyroscopic-means fori automatically stab'lizing he artificialtargetin `any/selectedng;
shaftspaced from said first shaft in the direction of torpedo discharge, an arm carried by the second shaft and having its free end portion slidably connected to said eccentric, a rotatable firing sight slidably connected to said eccentric for movement with said second shaft; a third shaft to one side of said other shafts, an artificial target carried by said shaft, pulleys on said first and third shafts, a belt .connecting said pulleys, whereby rotation of the third shaft correspondingly rotates the first shaft to maintain said target in parallel alignment with said arm and adjusts the eccentric and the firing sight synchronously, and gyroscopic means maintaining the artificial target in a preset direction in space.
3. In a torpedo carrying aircraft, a torpedo director comprising a first shaft having an axial passageway, an arm carried by the rst shaft, an eccentric slidable on the arm, a line extending through the passageway and connected to the eccentric, a spool for reeling in and paying out the line, resilient means maintaining tension on the line; a second shaft, an arm carried by the second shaft and having its free end portion slidably connected to the eccentric; a third shaft, an artificial target carried by said shaft, pulleys on said first shaft and third shaft, a belt connecting said pulleys whereby movement of the third shaft moves the first shaft to maintain said target and arm in parallel alignment and moves the eccentric and the firing sight synchronously, and gyro,- scopic means maintainingmthe artificialtgtin 4. In a torped'carrying aircraft, a torpedo director comprising first, second, and third shafts, the first shaft carrying an arm, an eccentric connected to the free end of said arm, means for adjusting the distance between the first and second shafts in the direction of a torpedo discharge, a sight bar carried by the second shaft and slidable in said eccentric, pulleys on the first and third shafts, a belt connecting said pulleys, gyro stabilizing means for the first and third shafts to directionally stabilize said shafts, an artificial target carried by the third shaft, whereby movement of the third shaft synchronously moves said artificial target, sight bar, eccentric and arm.
5. In a torpedo carrying aircraft, a torpedo director comprising a firing sight mounted at one end on a horizontally adjustable vertical pivot and having its other end slidably connected in a pivoted guide, an arm having said guide radially adjustably mounted thereon and said arm having a vertical axis spaced forwardly from said vertical pivot in the direction of said horizontal adjustment, an artificial target mounted on a second vertical pivot to one side of the firing sight, an operating connection between said guide arm and said second vertical pivot for simultaneous turning movement to maintain parallel alignment between said artificial target and said arm, a. directional stabilizing gyro means for directionally stabilizing the artificial target, equipped with manual setting means for said target operative to cage said gyro means during the setting operation whereby said artificial target, having been once set manually parallel to an actual target by eye, after the radial distance of the guide and the distance between said first vertical pivot and said arm axis have been set in accordance with the estimated target and torpedo speeds respectively, will maintain its parallel relationship to the actual target, so that upon mere sighting of the target after anyfur- Setlist litem ther maneuvers of the aircraft the torpedo may be sent on its proper course to score a hit.
6. In a torpedo carrying aircraft, a torpedo director comprising a ring sight mounted at one end on a horizontally adjustable vertical pivot, a vertically pivoted artificial target offset from said ring sight and accessible for manual alignment parallel with an observed target, a horizontal arm mounted on a second vertical pivot forwardly of said rst pivot and operatively connected to said artificial target for maintaining parallel alignment therewith, said arm having a pivoted guide radially adjustable thereon, the other end of said ring sight being slidably mounted in said guide, and means for directionally stabilizing said artificial target when once manually set parallel to an observed target, whereby automatic movement of said articial 6 target thereafter synchronously moves the firing sight angularly with respect to the fore and aft line between the first and second pivots to vary the angle of advance when sighting on the observed target in accordance with changes in the range of the observed target.
ROBERT M. FREEMAN.
REFERENCES CITED The `following lreferences are of record in the le of this patent:
UNITED STATES PATENTS Number Name Date 1,661,686 Bates Mar. 6, 1928 1,943,403 Watson Jan` 16, 1934 1,450,585 Ford Apr. 3, 1923
US454295A 1942-08-10 1942-08-10 Torpedo director Expired - Lifetime US2421749A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US454295A US2421749A (en) 1942-08-10 1942-08-10 Torpedo director

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US454295A US2421749A (en) 1942-08-10 1942-08-10 Torpedo director

Publications (1)

Publication Number Publication Date
US2421749A true US2421749A (en) 1947-06-10

Family

ID=23804081

Family Applications (1)

Application Number Title Priority Date Filing Date
US454295A Expired - Lifetime US2421749A (en) 1942-08-10 1942-08-10 Torpedo director

Country Status (1)

Country Link
US (1) US2421749A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2581138A (en) * 1946-05-08 1952-01-01 Richard W Pitman Torpedo director
US2581401A (en) * 1946-04-01 1952-01-08 Robert M Freeman Torpedo director
US2612692A (en) * 1945-07-14 1952-10-07 Herbert K Weiss Gyroscopic gun sight
US2692435A (en) * 1949-06-07 1954-10-26 Svenska Aeroplan Ab Wind drift computer for bombsights

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1450585A (en) * 1918-06-19 1923-04-03 Ford Instr Co Inc Pange and bearing keeper
US1661686A (en) * 1923-02-26 1928-03-06 Sperry Gyroscope Co Ltd Torpedo director
US1943403A (en) * 1931-03-16 1934-01-16 Vickers Armstrongs Ltd Apparatus for use in determining the course to be given to torpedoes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1450585A (en) * 1918-06-19 1923-04-03 Ford Instr Co Inc Pange and bearing keeper
US1661686A (en) * 1923-02-26 1928-03-06 Sperry Gyroscope Co Ltd Torpedo director
US1943403A (en) * 1931-03-16 1934-01-16 Vickers Armstrongs Ltd Apparatus for use in determining the course to be given to torpedoes

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2612692A (en) * 1945-07-14 1952-10-07 Herbert K Weiss Gyroscopic gun sight
US2581401A (en) * 1946-04-01 1952-01-08 Robert M Freeman Torpedo director
US2581138A (en) * 1946-05-08 1952-01-01 Richard W Pitman Torpedo director
US2692435A (en) * 1949-06-07 1954-10-26 Svenska Aeroplan Ab Wind drift computer for bombsights

Similar Documents

Publication Publication Date Title
US1936442A (en) Gun fire control apparatus
SE449659B (en) rifle scope
US2421749A (en) Torpedo director
JPH0319480B2 (en)
US2339011A (en) Glider torpedo
DE1623438C3 (en)
DE1623438B2 (en) Exercise device for directing missiles
US2534225A (en) Computing sight
US2570298A (en) Gyroscopically controlled electrical gun sight
US2407665A (en) Aircraft fire control computer
US2971437A (en) Apparatus for guided missiles
US2118041A (en) Bomb sighting device
US3438305A (en) Gun sighting system
US2356189A (en) Angle-of-lead control
US2438532A (en) Synchronizing bomb sight
US1759012A (en) Range under and gtot sight
US2424088A (en) Educational device for aerial gunners
US2404379A (en) Sight director
US1479840A (en) stone
US2325610A (en) Fire control instrument
US2504168A (en) Gunsight superelevation control device
US2476342A (en) Gun sight
US2162699A (en) Bomb sight
US2384098A (en) Ranging device
US1152946A (en) Range-finder for air-craft.