US3787770A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting a projectile leaving the barrel of a gun
Assignee: Department of National Defence
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Filing: 1972-06-19
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Granted: 1974-01-22
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Expires: 1992-06-19
Abstract
Abstract A method and apparatus for detecting a projectile leaving a gun using a permanent horse-shoe magnet located at or near the muzzle of the gun whereby the projectile cuts some of the magnetic lines of force of the magnet. Resultant voltage pulses from the separation of the projectile from the gun and from the passage of the projectile above the permanent magnet are induced in a pick up winding wound on the magnet and these are fed through an amplifier to an oscilloscope and/or a chronograph to provide an indication. The apparatus may also be utilized to measure the velocity of and to photograph the projectile as it leaves the muzzle of the gun.
Inventors
- 👤 P Cote
- 👤 C Roy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:31
CPC Classifications
F; F42; F42C; F42C17/00; F42C17/04; F42B; F42B35/00; G; G01; G01P; G01P3/00; G01P3/64; G01P3/66; G01P3/665; G04; G04F; G04F8/00; G04F8/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A method of detecting a projectile leaving the barrel of a gun comprising the steps of: locating a permanent magnet with a pickup winding thereon at a distance ''''X'''' from the muzzle of a gun, firing said gun and directing its projectile across at least one pole of said permanent magnet, obtaining a first voltage from said pickup winding when the arc discharge from the gun is detected and a second voltage as the projectile passes across the permanent magnet, feeding the resultant voltages induced in said winding to the input of an amplifier and feeding the output of the amplifier to an indicating means, obtaining the time ''''t'''' between said first and said second voltages and calculating the velocity of the projectile as it leaves the muzzle of the gun from the formula v x/t.
Claim 2
Independent Claim
136 words
A method of detecting a projectile leaving the barrel of a gun comprising the steps of: locating a permanent magnet with a pickup winding thereon at a distance ''''X'''' from the muzzle of a gun, firing said gun and directing its projectile across at least one pole of said permanent magnet, obtaining a first voltage from said pickup winding when the arc discharge from the gun is detected and a second voltage as the projectile passes across the permanent magnet, feeding the resultant voltages induced in said winding to the input of an amplifier and feeding the output of the amplifier to an indicating means, obtaining the time ''''t'''' between said first and said second voltages and calculating the velocity of the projectile as it leaves the muzzle of the gun from the formula v x/t.
Claim 3
Dependent Claim
130 words
Apparatus for detecting a projectile leaving the barrel of a gun comprising a permanent magnet located at a distance ''''x'''' from the muzzle of the gun and having a pick up winding wound therearound, an amplifier having its input connected to said pick up winding and indication when a projectile is detected, whereby, the permanent magnet pick up winding provides a first voltage when the arc discharge from the gun is detected and a second voltage is provided as the projectile passes across the permanent magnet to affect the magnetic field therearound, and said indicating means provides an indication of the difference in time ''''t'''' between said voltages, whereby, the velocity ''''v'''' of the projectile as it leaves the muzzle of the gun is given by the formula v x/t.
Claim 4
Dependent Claim
130 words
Apparatus for detecting a projectile leaving the barrel of a gun comprising a permanent magnet located at a distance ''''x'''' from the muzzle of the gun and having a pick up winding wound therearound, an amplifier having its input connected to said pick up winding and indication when a projectile is detected, whereby, the permanent magnet pick up winding provides a first voltage when the arc discharge from the gun is detected and a second voltage is provided as the projectile passes across the permanent magnet to affect the magnetic field therearound, and said indicating means provides an indication of the difference in time ''''t'''' between said voltages, whereby, the velocity ''''v'''' of the projectile as it leaves the muzzle of the gun is given by the formula v x/t.
Claim 5
Dependent Claim
14 words
Apparatus according to claim 2 wherein said permanent magnet is a horse-shoe permanent magnet.
Claim 6
Dependent Claim
12 words
Apparatus according to claim 2 wherein said indicating means is a chronograph.
Claim 7
Dependent Claim
12 words
Apparatus according to claim 2 wherein said indicating means is an oscilloscope.
Claim 8
Dependent Claim
39 words
Apparatus according to claim 2 wherein said permanent magnet is at a horizontal distance from the muzzle of the gun between 18 inches and 24 inches and approximately 5/8 inch below the line of sight of the gun muzzle.
Claim 9
Dependent Claim
39 words
Apparatus according to claim 2 wherein said permanent magnet is at a horizontal distance from the muzzle of the gun between 18 inches and 24 inches and approximately 5/8 inch below the line of sight of the gun muzzle.
Claim 10
Dependent Claim
38 words
Apparatus according to claim 2 wherein ballistic photographic means is provided and the magnet is utilized to pick up the arc discharge to trigger said ballistic photographic means and facilitate ballistic photography at the muzzle of the gun.
References Cited (Backward Citations)
US2301194A
Cited
US3281593A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |