Patent EP0076990A2 successfully refreshed from Google Patents.
EP0076990A2
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EP
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Stabilizing fin assembly for projectile
Assignee: AFFAERSVERKET FFV
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Filing: 1982-10-02
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Granted: —
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Expires: 2002-10-02
Abstract
Abstract Stabilizing fin assembly for projectile (2) designed to be discharged from a barrel (1) by means of propellant charge gases from a propellant charge (5). During their passage through the barrel the fins (8) are in the retracted, on-edge position, and arranged to be extended when the projectile (2) leaves the barrel (1). With the fins in the retracted position the space (13) between the fins (8) is at least partially open to the rear during passage through the barrel, so that the propellant charge gases have acces to the said space (13). The space (13) is exhausted of propellant charge gases when the projectile leaves the barrel (1), and the propellant charge gases as they rush out pass along the guide surfaces of the fins (8), causing a frictional force which jerks the fins (8) to the extended position. In some embodiments the guidance mechanism is also provided with a further space (11, 18, 18a) under the edge (12) of the fins (8), which during passage through the barrel is filled with propellant charge gases which exert an extra extending force against the edge (12) of the fins (8).
Inventors
- 👤 Jan-Erik Sandberg
- 👤 Torbjörn Pramskog
- 👤 Bengt Larsson
- 👤 Börje Johansson
- 👤 Sven Andersson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 12:02
CPC Classifications
F; F42; F42B; F42B10/00; F42B10/02; F42B10/14; F42B10/20
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
267 words
Stabilizing fin assembly for projectile (2) designed to be discharged from a barrel (1) by means of propellant charge gases comprising a plurality of elongated fins (8) rotatably mounted at one end which are arranged so that during the passage of the projectile through the barrel (1) they are in the retracted position in which the fins (8) are placed on edge, extending mutually in parallel and essentially in the lengthwise direction of the projectile (2), characterised in that the space (13) between the fins (8) and/or a further space (11, 18 18a) which is located under an edge (12) on the fins (8) which faces towards the projectile axis is at least partially open to the rear during the passage of the projectile (2) through the barrel (1), thus permitting access on the part of the propellant charge gases to the said space (13) or the said further space (11, 18, 18a), by means of which the passage of the projectile (2) past the muzzle of the barrel results in the propellant charge gases in the said space (13) or said further space (11, 18, 18a) rushing out to the atmosphere surrounding the barrel (1) and then jerking with them the fins (8) to the extended position, firstly because of the entraining frictional force which arises when the propellant charge gases pass along the guide surfaces of the fins, and partially - in the event of said further space (11, 18, 18a) being present - because of the pressure which the gases in the further space exert against the said edge (12) on the fins (8).
Claim 2
Dependent Claim
267 words
Stabilizing fin assembly for projectile (2) designed to be discharged from a barrel (1) by means of propellant charge gases comprising a plurality of elongated fins (8) rotatably mounted at one end which are arranged so that during the passage of the projectile through the barrel (1) they are in the retracted position in which the fins (8) are placed on edge, extending mutually in parallel and essentially in the lengthwise direction of the projectile (2), characterised in that the space (13) between the fins (8) and/or a further space (11, 18 18a) which is located under an edge (12) on the fins (8) which faces towards the projectile axis is at least partially open to the rear during the passage of the projectile (2) through the barrel (1), thus permitting access on the part of the propellant charge gases to the said space (13) or the said further space (11, 18, 18a), by means of which the passage of the projectile (2) past the muzzle of the barrel results in the propellant charge gases in the said space (13) or said further space (11, 18, 18a) rushing out to the atmosphere surrounding the barrel (1) and then jerking with them the fins (8) to the extended position, firstly because of the entraining frictional force which arises when the propellant charge gases pass along the guide surfaces of the fins, and partially - in the event of said further space (11, 18, 18a) being present - because of the pressure which the gases in the further space exert against the said edge (12) on the fins (8).
Claim 3
Dependent Claim
42 words
Assembly as in claim 1, characterised in that the said space (13) is at the front at least partially sealed in respect of the surrounding atmosphere by means of a projectile girdle (3) or guide pad arranged in front of the fins.
Claim 4
Dependent Claim
39 words
Assembly in accordance with either of claims 1 - 2, characterised in that the fixed pivot (9) of the fins is located at the rear end of the fins (8) viewed in the retracted position of the fins (8).
Claim 5
Dependent Claim
69 words
Assembly in accordance with any of claims 1 - 3, characterised in that the fins (8) in the retracted position have their centre of gravity (G) closer to the projectile axis than the fixed pivot (9) of the fins, so that a moment is brought about by the accelerational forces imposed on the projectile (2), which moment attempts to hold the fins (8) in during passage through the barrel.
Claim 6
Dependent Claim
43 words
Assembly in accordance with any of claims 1 - 4, characterised in that the fins (8) are rotatably around a pivot (9) which is provided with friction-reducing devices (10), e.g. teflon washers, so as to increase the swivelling capacity of the fins (8).
Claim 7
Dependent Claim
29 words
Assembly in accordance with any of claims 1 - 5, characterised in that the fins (8) are skew-mounted relative to the projectile axis in a pre-determined skew angle (v).
Claim 8
Dependent Claim
40 words
Assembly as in claim 6, characterised in that the skewing action is obtained in that the fins (8) are mounted in grooves (14) which together with the projectile axis form an angle which corresponds to the said skew angle (v).
Claim 9
Dependent Claim
31 words
Assembly in accordance with any of claims 6 - 7, characterised in that the fins (8) in the retracted position rest against at least one supporting heel (15) or the like.
Claim 10
Dependent Claim
27 words
Assembly in accordance with any of claims 1 - 8, characterised in that the space (13) between the fins communicates with the further space (11, 18, 18a).
Claim 11
Dependent Claim
49 words
Assembly in accordance with any of claims 1 - 9, characterised in that the further space comprises a chamber (18, 18a) which is essentially cylindrical and arranged centrally in the guidance mechanism, in the walls of which there are apertures (19, 21) which are faced by the said edges.
Claim 12
Dependent Claim
33 words
Assembly in accordance with claim 10, characterised in that the apertures are in the form of slots (19), through which the fins (8) can be introduced at least partially in the retracted position.
Claim 13
Dependent Claim
65 words
Assembly in accordance with any of claims 1 - 8, characterised by a cylindrical tube (25) which concentrically surrounds the space (13) between the fins (8), whereby the generatrix of the tube (25) is provided with slots (24) of at least the same length as the fins (8), and where the slots (24) are so placed that the fins (8) can be extended through them.
References Cited (Backward Citations)
No citation records indexed.
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