US3766826A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for achieving aim-off for a firearm
Assignee: Saab Bofors AB
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Filing: 1972-02-08
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Granted: 1973-10-23
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Expires: 1992-02-08
Abstract
Abstract A gun is described in which a gun barrel and a gun sight are mounted for movement together in deploying the gun in azimuth and in elevation under the action of servo drive means. A tracking unit is provided to control the servo drive means, which may comprise separate servo motors for rotating an upper mounting of the gun in azimuth and for rotating the gun barrel in elevation relative to the upper mounting. The tracking unit has two separate phases of operation. In its first phase of operation, the tracking unit produces controlling signals which represent the behaviour of a target as sensed by a gun layer controlling an aiming device and a rangefinder to produce aiming and range signals which form inputs to the tracking unit. In its second phase of operation, the tracking unit produces controlling signals which represent a predicted behaviour of the target by maintaining constant a function of the controlling signals which is determined by the particular nature the controlling signals take and the assumed behaviour of the target. When the controlling signals represent the Cartesian coordinates of the position vector of the target, and it is assumed that the target is moving with constant velocity along a straight line at the time of firing the gun, the time derivative of the controlling signals is maintained constant. Auxilliary circuits are described by which aim-off corrections may be made on the basis of the estimated time of flight of a projectile to the target depending on known ballistic properties of the projectile and on ambient atmospheric conditions.
Inventors
- 👤 H Salomonsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:12
CPC Classifications
F; F41; F41A; F41A27/00; F41A27/06; F41G; F41G3/00; F41G3/06; F41G5/00; F41G5/08; G; G06; G06G; G06G7/00; G06G7/48; G06G7/80
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
164 words
A deployable gun for shooting at a target, the gun comprising: a gun barrel having a gun sight connected thereto with the line of aim of said sight always being in fixed alignment with the line of said barrel; common servo drive means for moving the gun barrel and the gun sight together; aiming and rangefinding means controllable by a gunlayer for producing aiming and range signals; and a tracking unit operative to produce signals for controlling the servo drive means and having two phases of operation, the tracking unit including means operative in its first phase of operation to produce said signals in dependence on the aiming and range signals such that the controlling signals represent the behaviour of the target as sensed by the gunlayer, and said tracking means including means operative in its second phase of operation to maintain at least the target velocity components of said controlling signals constant whereby the controlling signals represent a predicted behaviour of the target.
Claim 2
Dependent Claim
164 words
A deployable gun for shooting at a target, the gun comprising: a gun barrel having a gun sight connected thereto with the line of aim of said sight always being in fixed alignment with the line of said barrel; common servo drive means for moving the gun barrel and the gun sight together; aiming and rangefinding means controllable by a gunlayer for producing aiming and range signals; and a tracking unit operative to produce signals for controlling the servo drive means and having two phases of operation, the tracking unit including means operative in its first phase of operation to produce said signals in dependence on the aiming and range signals such that the controlling signals represent the behaviour of the target as sensed by the gunlayer, and said tracking means including means operative in its second phase of operation to maintain at least the target velocity components of said controlling signals constant whereby the controlling signals represent a predicted behaviour of the target.
Claim 3
Dependent Claim
57 words
A gun according to Claim 1, wherein the gun sight and the gun barrel are affixed to one another, said servo drive means comprising a first servo motor for rotating the gun barrel and the gun sight together in elevation, and a second servo motor for rotating the gun barrel and the gun sight together in azimuth.
Claim 4
Dependent Claim
61 words
A gun according to claim 1, wherein the gun barrel and the gun sight are connected to one another via a mechanical linkage, said servo drive means comprising a first servo motor for rotating the gun barrel and the gun sight together in elevation, and a second servo motor for rotating the gun barrel and the gun sight together in azimuth.
Claim 5
Dependent Claim
51 words
A gun according to claim 1, wherein the controlling signals produced by the tracking unit represent components of the velocity of the target in a Cartesian coordinate system, and wherein the tracking unit is arranged in its second phase of operation to maintain the time derivatives of the controlling signals constant.
Claim 6
Dependent Claim
115 words
A gun according to Claim 1, wherein said servo drive means comprises a first servo motor for rotating the gun barrel in elevation and a second servo motor for rotating the gun barrel in azimuth; said servo motors being operative to generate elevation and azimuth error signals to servo control movement of the gun barrel in operation; said servo motors being further operative to produce a slant range signal referred to a polar coordinate system centered at the gun, and means For transmitting the slant range signal to the tracking unit in addition to the range signal, whereby the controlling signals produced by the tracking unit are at least partly dependent on the slant range.
Claim 7
Dependent Claim
97 words
A gun according to claim 1, wherein the controlling signals produced by the tracking unit represent the components of the position of the target in a Cartesian coordinate system; and wherein the tracking unit comprises respective integrators for the respective Cartesian coordinates adapted to produce at their respective outputs the said controlling signals; and the tracking unit further comprises means for determining the components of the velocity of the target in a Cartesian coordinate system from the aiming and range signals, and means for transmitting said velocity component signals to the respective inputs of the respective integrators.
Claim 8
Dependent Claim
98 words
A gun according to Claim 1, wherein the aiming and rangefinding means are arranged to produce aiming and range signals which are in the form of correction signals referred to a polar coordinate system centered at the gun; and wherein the tracking unit comprises means for converting the aiming and range correction signals in polar form to correction signals referred to a Cartesian coordinate system, and a signal processing unit comprising for each Cartesian coordinate an integrator and an adder arranged together to produce an output signal representing the sum of the Cartesian correction signal and its integral.
Claim 9
Dependent Claim
28 words
A gun according to claim 7, wherein the tracking unit is arranged in its second phase of operation to maintain the values of the respective output signals constant.
Claim 10
Dependent Claim
88 words
A gun according to claim 1, wherein the tracking unit further includes means for producing correction signals to achieve aim-off and comprising means for estimating the time of flight of a projectile to the target from data signals present in the tracking unit and from additional data input signals dependent on known properties of the projectile employed and on weather conditions, means for generating aim-off correction signals in response to the estimated time of flight, and means modifying the controlling signals in accordance with respective aim-off correction signals.
Claim 11
Dependent Claim
31 words
A gun according to claim 9, wherein means are provided for automatically adding the aim-off correction signals to the controlling signals during the second phase of operation of the tracking unit.
Claim 12
Dependent Claim
37 words
A gun according to claim 9, wherein means are provided for automatically adding the aim-off correction signals to the controlling signals at the change over from the first phase of operation to the second phase of operation.
Claim 13
Dependent Claim
150 words
A gun according to Claim 6, wherein the tracking unit further comprises means of achieving aim-off, and comprising for each of the controlling signals generated by the tracking unit a multiplier connected in parallel with said integrator; calculating means for providing signals corresponding to the estimated time-of-flight of a round to the multipliers, the calculating means being arranged to produce time of flight signals in response to a first input representing the slant range and second and third signals respectively representing correction values for varying muzzle velocities of rounds of ammunition of different kinds and correction values relating to variations in atmospheric conditions, means being provided for manually setting said values in the calculating means; and means for adding the aim-off correction signals produced by the respective multipliers to the respective controlling signals, at a time not preceding the commencement of the second phase of operation of the tracking unit.
Claim 14
Dependent Claim
106 words
A gun according to claim 12, wherein the calculating means comprises an integrator, means for generating a first ammunition-dependent signal which is an inverse function of the muzzle velocity of the round and which is a function of the slant range, means for generating a second signal which is a function of the atmospheric condiTions, a multiplier for multiplying said first and second signals together, and an integrator whose input signals comprise said first signal and the result of multiplying said first and second signals and which integrator is provided with a negative feedback loop, the time-of-flight calculated signal consisting of the output of said integrator.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |