US20160223305A1 - Projectile - Google Patents
Projectile Download PDFInfo
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- US20160223305A1 US20160223305A1 US14/068,341 US201314068341A US2016223305A1 US 20160223305 A1 US20160223305 A1 US 20160223305A1 US 201314068341 A US201314068341 A US 201314068341A US 2016223305 A1 US2016223305 A1 US 2016223305A1
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- United States
- Prior art keywords
- projectile
- fin
- pivot
- deployed position
- fins
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- 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.)
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
- F42B10/00—Means for influencing, e.g. improving, the aerodynamic properties of projectiles or missiles; Arrangements on projectiles or missiles for stabilising, steering, range-reducing, range-increasing or fall-retarding
- F42B10/02—Stabilising arrangements
- F42B10/14—Stabilising arrangements using fins spread or deployed after launch, e.g. after leaving the barrel
- F42B10/16—Wrap-around fins
Definitions
- the present invention relates to a finned projectile for a small arms weapon having a barrel, such as a shotgun, and in particular to a small arms projectile having improved fin configuration.
- Small arms projectiles for small arms weapons are packaged with a cartridge cover or sleeve, which also houses a propellant charge at the rear of the projectile, adjacent to an initiator or primer provided on the cartridge's cap.
- the cartridge is loaded into a barrel of a small arms weapon and firing causes the detonation of the initiator, which in turn detonates the propellant charge, thereby propelling the projectile out of the cartridge cover, along the weapon's barrel, and though the air.
- WO 02/090870 describes a known projectile having four deployable fins mounted around the circumference of the rear section of the projectile body. Each of the fins has a curved form which matches to fit the outer surface of the projectile body when folded there against. This thereby allows the projectile to fit within and move along the weapon's barrel when fired.
- the projectile's fins are held in this inward folded (un-deployed) position by the cartridge cover prior to firing. On firing, the projectile is ejected from the cover and forced along the weapon's barrel.
- the fins are no longer constrained, and are hence able to move to a radially outward (deployed) position. Once deployed, the fins help to provide stability during flight, resulting in a relatively higher level of accuracy over a given range.
- a projectile for a small arms weapon comprising:
- peripheral fins each pivotably coupled to the projectile body at a pivot for movement from a un-deployed position to a deployed position
- each of the fins comprises a straight section and a connecting section connecting the straight section to the pivot and being configured so that the plane of the straight section is offset from the pivot axis.
- the present invention allows for improved stability during flight, thereby resulting in improved accuracy over a given range.
- the inventor has found that the major air flow past the projectile is at a distance from the projectile's body. As such, there is normally only a limited interaction between the air flow and the deployed fins because only the distal ends of the fins encounter any significant air flow for assisting in providing stability.
- the fins of the present invention have a straight section which provides a flat or planar profiled region at the distal end of the fin. This allows the fins to project radially further outward from the projectile's longitudinal axis once deployed because the radial vector component of the fin is longer for a given fin length. This in turn allows a greater proportion of the fin to extend into the major air flow, thereby improving their stabilising effect.
- the connecting section forms a coupling with the projectile's body and positions the straight section so that its plane does not pass through the fin's pivot axis.
- the connecting section has the effect of allowing the fin to reach around the projectile's body. That is, when in the un-deployed position, the connecting section is able to angle the straight section back toward the circumferential surface of the projectile's body. This allows a longer fin to be accommodated within the projectile's outer circumferential profile.
- the plane of the straight section of each fin lies substantially at a tangent plane to the circumferential surface of the projectile body when in the un-deployed position.
- the tangent point is substantially in the centre of the fins straight section. This maximises the length of the straight section which can be accommodated.
- the projectile further comprises a channel formed around the circumference of the projectile body for receiving the plurality of fins when in the un-deployed position.
- the channel provides a region for locating the fins within the outer circumferential profile of the projectile, when they are in their un-deployed position.
- each fin extends straight out from the projectile's body when in the deployed position. In this way, the distance by which the fins project outwardly from the longitudinal axis of the projectile is maximised.
- the bottom surface of the channel further comprises a flat section adjacent to the pivot of each fin. This allows each fin to reach further around the body of the projectile, thereby allowing longer length fins to be incorporated.
- the inner surface of the connecting section of each fin may lie flush with the adjacent flat section of the channel.
- the plane of the straight section of each fin projects substantially radially outward.
- each fin is integrally formed. In this this way, a simple reliable construction is provided.
- the length of the straight section of each fin is longer than the length of the connecting section. In this way, the outward projection of each fin in a radial vector is maximised.
- the straight section of each fin comprises at least one flat surface parallel to the plane of the straight section. In this way, a simple, yet aerodynamically efficient configuration is provided.
- each fin comprises a coupling connected to the respective fin's pivot and a linking region between the coupling and the fin's straight section, the linking region being angled relative to the straight section.
- the projectile further comprises biassing means for biassing each fin toward its radially deployed position.
- the fins automatically deploy to their maximum radial position as soon as they leave the constraints of the cartridge cover and the weapon's barrel.
- the biassing means comprises a spring located at each pivot. In this way, a simple and mechanically reliable bias is provided.
- each fin comprises a tapered edge.
- the distal edge of each fin can lie flush with the curvature of the projectile's outer circumferential profile, as defined, for example, by the sides of the channel.
- each fin is configured to overlie the pivot of an adjacent fin. This allows longer length fins to be incorporated.
- the projectile comprises three or four fins.
- a projectile for a small arms weapon comprising: a projectile body; a plurality of peripheral fins each coupled to the projectile body at a pivot for rotation from a folded position to a deployed position, where each of the fins comprises a straight section and a connecting section connecting the straight section to the pivot, the straight and connecting sections being angled relative to one another so that, when in the folded position, each fin extends around a portion of the projectile body and, when in the deployed position, the straight section of each fin extends straight out from the projectile's body.
- the straight/flat fin profile allows the fin to extend further into the major airflow past the projectile during flight, thereby improving its stability.
- a projectile for a small arms weapon comprising: a projectile body a plurality of peripheral fins each pivotably coupled to the projectile body at a pivot for movement from a radially un-deployed position to a radially deployed position; a channel formed around the circumference of the projectile body for receiving the plurality of fins when in the un-deployed position, wherein the pivot for each fin is positioned sufficiently towards the longitudinal axis of the projectile body to enable the distal end of each fin to overlie the pivot of the adjacent fin when the fins are in the un-deployed position. In this way, longer fins can be accommodated.
- each fin has a generally L shaped form to define a major portion distal from the pivot and a minor portion proximal to said pivot.
- the major portion provides a substantially flat surface.
- each said fin includes opposing lugs and each pivot comprises a pin located through said lugs.
- the distal end of the major portion is shaped to enable it to fit between the lugs of an adjacent fin in the un-deployed position.
- FIG. 1 shows a perspective view of a projectile according to a first embodiment of the invention, with the fins shown in a deployed position;
- FIG. 2 shows a rear cross-sectional view of the projectile shown in FIG. 1 , with the fins shown in the deployed position;
- FIG. 3 shows a rear cross-sectional view of the projectile shown in FIG. 1 , with the fins shown in an un-deployed position.
- FIG. 4 shows a rear cross-sectional view of the projectile according to a second embodiment of the invention, with the fins shown in an un-deployed position.
- FIG. 5 is a perspective view of a fin according the second embodiment.
- FIGS. 1 to 3 show a projectile 1 according to a first embodiment of the present invention.
- the projectile 1 has a body 3 comprising a front section 4 , containing the warhead, and a rear section 8 .
- the rear section 8 includes mounting formations 7 , which support coupling pins 5 , onto which fins 2 are pivotably coupled.
- the coupling pins 5 provide a pivot axis which is parallel to the longitudinal axis of the projectile body and allow the fins to rotate or swing outwardly.
- the fins 2 are able to move from a un-deployed or folded position, as shown in FIG. 3 , to deployed position, as shown in FIGS. 1 and 2 , where the fins extend straight out from the projectile body.
- Fin deployment springs 6 are provided on coupling pins 5 , with one end of each spring 6 engaging the projectile body 3 and the other end received by a formation provided at the base of its respective fin 2 .
- the springs 6 act to bias the fins 2 outwardly to their deployed position.
- the ends of the spring 6 applying a rotational force between the projectile body 3 and the fin 2 they are also configured to bias the fins 2 rearwardly along the longitudinal axis of the projectile 1 for locking the fins 2 into the deployed position once deployed.
- the mounting formations 7 also support stopping pins 9 , which prevent the fins 2 from rotating beyond their deployed position.
- the projectile body 3 comprises a recessed channel defined between the mounting formations 7 into which fins 2 are received when in the un-deployed position.
- FIG. 3 shows a rear cross-sectional view of the projectile 1 when the fins are in the un-deployed position.
- the channel 11 allows the fins to be located within the outer circumferential profile of the projectile body, as viewed looking down the projectile's longitudinal axis. This thereby allows the projectile to fit within the bore of a small arms weapon's barrel.
- each fin 2 comprises a connecting section 13 adjacent to the coupling pin 5 which connects to a straight second section 14 .
- the connecting section 13 is configured such that the plane of the straight section 14 (i.e. the notional plane passing through the middle of the straight section 14 , parallel with its major surfaces) is offset from the pivot axis formed by coupling pin 5 . That is, the plane of the straight section does not pass through the pivot point formed by the coupling. As such, the connecting section 13 angles the straight section 14 back toward the bottom circumferential surface of the channel 11 .
- FIG. 3 also shows that, in the un-deployed position, the planes of each straight section of each fin 2 lie substantially at a tangential plane to the curve of the recessed surface of the channel 11 of the projectile body 3 , with the middle of the straight section 14 being located substantially at the tangent point.
- the planes of each straight section are indicated by dotted lines in FIG. 3 and pass through the centre of the planar or flat part of each fin's straight section 14 .
- the bottom surface of the channel 11 further comprises a flattened section 12 adjacent to the coupling 5 of each fin 2 , as can be seen in FIG. 1 .
- This allows the coupling pins 5 to be recessed radially toward the projectile's central axis, which in turn allows the fins to reach further around the projectile's body when in an un-deployed position.
- each fin 2 is additionally provided with a tapered edge 15 along its distal end.
- the tapered edges 15 lie flush with the curvature of the sides of the channel 11 when in the un-deployed position so as to help maximise the length of each fin, without extending beyond the outer circumferential profile of the projectile.
- the projectile 1 In use, the projectile 1 is initially enclosed within a cartridge cover, which holds the fins 2 in their un-deployed position.
- the propellant detonates, propelling the projectile 1 from its cartridge and along the weapon's barrel.
- the fins 2 are no longer constrained by the cover or weapon's barrel, allowing them to deploy under the bias of springs 6 .
- the fins 2 are prevented from rearward movement as the rear edge of the fin 2 is biased against the rear rim of mountings 7 .
- the radially outward bias acts to rotate each fin 2 out to its deployed position. Once in this position, the back of the fin 2 contacts its stopping pin 9 , thereby preventing further rotation of the fin 2 .
- a notch provided at the rear of the fin aligns with the rear rim of mounting 7 , thereby allowing each fin 2 to slide rearwardly along its coupling pin 5 under the bias of its spring 6 . This acts such that the notch slides over the rim of mounting 7 into an engaged position, with the surfaces of these formations mating with one another.
- each fin 2 mates with a counter surface on the rim of mounting 7 providing a circumferential support surface on the projectile body for supporting each fin 2 .
- the fins 2 are effectively locked in their deployed position since they are biased rearwardly into this engaged position. Locking the fins into place in this manner has the advantage of providing enhanced stability during flight.
- This configuration helps to provide improved accuracy over long ranges when compared to curved fins. This is because, for a given length, the fins extend further outward in a radial direction, allowing a greater proportion of their surface to interact with the major airflow past the projectile during its flight.
- FIGS. 4 and 5 show a second embodiment of the invention, with FIG. 4 showing a rear cross-sectional view of the projectile with the fins in an un-deployed position, and FIG. 5 showing a perspective view of one of the fins.
- This second embodiment is similar to the first embodiment, except that each fin 2 is configured to extend beyond the mounting of the next adjacent fin.
- Like features have been assigned the same reference numerals.
- each fin 2 is pivotally mounted to the projectile body 3 by a pin 5 which forms a pivot.
- the straight section 15 of each fin 2 extends around the circumference of the projectile body 3 by a distance sufficient to enable the distal end of the straight section 15 of each fin 2 to overlie the adjacent fin's pivot 5 , when in the un-deployed position.
- flattened sections 12 allow each fin's pivot 5 to be positioned closer to the longitudinal axis of the projectile body 3 than the curved surface of the channel 11 .
- fin 2 is formed from a single piece of thin flat metal, which is bent into a generally L shaped form.
- the fins have a major portion forming straight section 14 and a minor portion forming connecting section 13 .
- the connecting section 13 is provided with two opposing lugs 16 which form the mounting through which the fins pivotally couple to pin 5 .
- the fin's straight section 14 is also provided with a narrowed region at its distal end which allows it to fit between the lugs 16 of the adjacent fin 2 . This enables each fin to overlie its next adjacent fin 2 , allowing a longer fin shape to be accommodated.
- the straight sections of the fins have a uniform thickness defined by two substantially flat side surfaces, it will be understood that the fins could have an alternative cross sectional profile.
- the fin may have a tapered construction, where the flat surfaces taper inward toward the plane defined though the middle of the straight/planar section of the fin.
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Abstract
A projectile (1) for a small arms weapon, the projectile (1) comprising a projectile body (3), a plurality of peripheral fins (2) each pivotably coupled to the projectile body (3) at a pivot (5) for movement from a un-deployed position to a deployed position. Each of the fins (2) comprises a straight section (14) and a connecting section (13) connecting the straight section (14) to the pivot (5) and being configured so that the plane of the straight (14) section is offset from the pivot (5) axis.
Description
- The present invention relates to a finned projectile for a small arms weapon having a barrel, such as a shotgun, and in particular to a small arms projectile having improved fin configuration.
- Small arms projectiles for small arms weapons are packaged with a cartridge cover or sleeve, which also houses a propellant charge at the rear of the projectile, adjacent to an initiator or primer provided on the cartridge's cap. In use, the cartridge is loaded into a barrel of a small arms weapon and firing causes the detonation of the initiator, which in turn detonates the propellant charge, thereby propelling the projectile out of the cartridge cover, along the weapon's barrel, and though the air.
- Small arms projectiles which have stabilising fins for improved accuracy are known in the art. For example, WO 02/090870 describes a known projectile having four deployable fins mounted around the circumference of the rear section of the projectile body. Each of the fins has a curved form which matches to fit the outer surface of the projectile body when folded there against. This thereby allows the projectile to fit within and move along the weapon's barrel when fired. The projectile's fins are held in this inward folded (un-deployed) position by the cartridge cover prior to firing. On firing, the projectile is ejected from the cover and forced along the weapon's barrel. Once the projectile has exited the weapon's barrel, the fins are no longer constrained, and are hence able to move to a radially outward (deployed) position. Once deployed, the fins help to provide stability during flight, resulting in a relatively higher level of accuracy over a given range.
- According to an aspect the present invention there is provided a projectile for a small arms weapon, the projectile comprising:
- a projectile body;
- a plurality of peripheral fins each pivotably coupled to the projectile body at a pivot for movement from a un-deployed position to a deployed position;
- wherein each of the fins comprises a straight section and a connecting section connecting the straight section to the pivot and being configured so that the plane of the straight section is offset from the pivot axis.
- In this way, the present invention allows for improved stability during flight, thereby resulting in improved accuracy over a given range. In this respect, the inventor has found that the major air flow past the projectile is at a distance from the projectile's body. As such, there is normally only a limited interaction between the air flow and the deployed fins because only the distal ends of the fins encounter any significant air flow for assisting in providing stability. To address this, rather than adopting a curved profile, the fins of the present invention have a straight section which provides a flat or planar profiled region at the distal end of the fin. This allows the fins to project radially further outward from the projectile's longitudinal axis once deployed because the radial vector component of the fin is longer for a given fin length. This in turn allows a greater proportion of the fin to extend into the major air flow, thereby improving their stabilising effect.
- One of the difficulties with adopting a straight fin profile for small arms projectiles is accommodating the fins when they are in an un-deployed or folded position because the fins must be located within the outer circumferential profile of the projectile in order that the projectile may fit within the weapon's barrel. However, in the present invention, the connecting section forms a coupling with the projectile's body and positions the straight section so that its plane does not pass through the fin's pivot axis. As such, rather than the fins projecting away from the projectile body at a tangent from the fins pivot when folded, the connecting section has the effect of allowing the fin to reach around the projectile's body. That is, when in the un-deployed position, the connecting section is able to angle the straight section back toward the circumferential surface of the projectile's body. This allows a longer fin to be accommodated within the projectile's outer circumferential profile.
- Preferably the plane of the straight section of each fin lies substantially at a tangent plane to the circumferential surface of the projectile body when in the un-deployed position. In this way, longer fins may be incorporated without protruding from the projectile's outer circumferential profile. In this respect, in a preferred embodiment, the tangent point is substantially in the centre of the fins straight section. This maximises the length of the straight section which can be accommodated.
- Preferably, the projectile further comprises a channel formed around the circumference of the projectile body for receiving the plurality of fins when in the un-deployed position. In this way, the channel provides a region for locating the fins within the outer circumferential profile of the projectile, when they are in their un-deployed position.
- Preferably, the straight section of each fin extends straight out from the projectile's body when in the deployed position. In this way, the distance by which the fins project outwardly from the longitudinal axis of the projectile is maximised.
- Preferably the bottom surface of the channel further comprises a flat section adjacent to the pivot of each fin. This allows each fin to reach further around the body of the projectile, thereby allowing longer length fins to be incorporated. In a preferred embodiment, the inner surface of the connecting section of each fin may lie flush with the adjacent flat section of the channel.
- Preferably, when in a deployed position, the plane of the straight section of each fin projects substantially radially outward.
- Preferably, each fin is integrally formed. In this this way, a simple reliable construction is provided.
- Preferably, the length of the straight section of each fin is longer than the length of the connecting section. In this way, the outward projection of each fin in a radial vector is maximised.
- Preferably, the straight section of each fin comprises at least one flat surface parallel to the plane of the straight section. In this way, a simple, yet aerodynamically efficient configuration is provided.
- Preferably, the connecting section of each fin comprises a coupling connected to the respective fin's pivot and a linking region between the coupling and the fin's straight section, the linking region being angled relative to the straight section.
- Preferably, the projectile further comprises biassing means for biassing each fin toward its radially deployed position. In this way, the fins automatically deploy to their maximum radial position as soon as they leave the constraints of the cartridge cover and the weapon's barrel.
- Preferably, the biassing means comprises a spring located at each pivot. In this way, a simple and mechanically reliable bias is provided.
- Preferably the distal end of each fin comprises a tapered edge. In this way, when in the un-deployed position, the distal edge of each fin can lie flush with the curvature of the projectile's outer circumferential profile, as defined, for example, by the sides of the channel.
- In an embodiment, each fin is configured to overlie the pivot of an adjacent fin. This allows longer length fins to be incorporated.
- Preferably, the projectile comprises three or four fins.
- According to a further aspect of the present invention, there is provided a projectile for a small arms weapon, the projectile comprising: a projectile body; a plurality of peripheral fins each coupled to the projectile body at a pivot for rotation from a folded position to a deployed position, where each of the fins comprises a straight section and a connecting section connecting the straight section to the pivot, the straight and connecting sections being angled relative to one another so that, when in the folded position, each fin extends around a portion of the projectile body and, when in the deployed position, the straight section of each fin extends straight out from the projectile's body. In this way, the straight/flat fin profile allows the fin to extend further into the major airflow past the projectile during flight, thereby improving its stability.
- According to yet a further aspect of the present invention, there is provided a projectile for a small arms weapon, the projectile comprising: a projectile body a plurality of peripheral fins each pivotably coupled to the projectile body at a pivot for movement from a radially un-deployed position to a radially deployed position; a channel formed around the circumference of the projectile body for receiving the plurality of fins when in the un-deployed position, wherein the pivot for each fin is positioned sufficiently towards the longitudinal axis of the projectile body to enable the distal end of each fin to overlie the pivot of the adjacent fin when the fins are in the un-deployed position. In this way, longer fins can be accommodated.
- Preferably, each fin has a generally L shaped form to define a major portion distal from the pivot and a minor portion proximal to said pivot.
- Preferably, the major portion provides a substantially flat surface.
- Preferably, the minor portion of each said fin includes opposing lugs and each pivot comprises a pin located through said lugs.
- Preferably, the distal end of the major portion is shaped to enable it to fit between the lugs of an adjacent fin in the un-deployed position.
- Illustrative embodiments of the present invention will now be described with reference to the accompanying drawings in which:
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FIG. 1 shows a perspective view of a projectile according to a first embodiment of the invention, with the fins shown in a deployed position; -
FIG. 2 shows a rear cross-sectional view of the projectile shown inFIG. 1 , with the fins shown in the deployed position; -
FIG. 3 shows a rear cross-sectional view of the projectile shown inFIG. 1 , with the fins shown in an un-deployed position. -
FIG. 4 shows a rear cross-sectional view of the projectile according to a second embodiment of the invention, with the fins shown in an un-deployed position. -
FIG. 5 is a perspective view of a fin according the second embodiment. -
FIGS. 1 to 3 show a projectile 1 according to a first embodiment of the present invention. Theprojectile 1 has a body 3 comprising a front section 4, containing the warhead, and arear section 8. Therear section 8 includes mountingformations 7, which supportcoupling pins 5, onto whichfins 2 are pivotably coupled. The coupling pins 5 provide a pivot axis which is parallel to the longitudinal axis of the projectile body and allow the fins to rotate or swing outwardly. As such, thefins 2 are able to move from a un-deployed or folded position, as shown inFIG. 3 , to deployed position, as shown inFIGS. 1 and 2 , where the fins extend straight out from the projectile body. - Fin deployment springs 6 are provided on
coupling pins 5, with one end of each spring 6 engaging the projectile body 3 and the other end received by a formation provided at the base of itsrespective fin 2. The springs 6 act to bias thefins 2 outwardly to their deployed position. As well as the ends of the spring 6 applying a rotational force between the projectile body 3 and thefin 2, they are also configured to bias thefins 2 rearwardly along the longitudinal axis of theprojectile 1 for locking thefins 2 into the deployed position once deployed. The mountingformations 7 also support stoppingpins 9, which prevent thefins 2 from rotating beyond their deployed position. - The projectile body 3 comprises a recessed channel defined between the mounting
formations 7 into whichfins 2 are received when in the un-deployed position. In this respect,FIG. 3 shows a rear cross-sectional view of the projectile 1 when the fins are in the un-deployed position. As shown, in this position thechannel 11 allows the fins to be located within the outer circumferential profile of the projectile body, as viewed looking down the projectile's longitudinal axis. This thereby allows the projectile to fit within the bore of a small arms weapon's barrel. - As shown in
FIG. 3 , eachfin 2 comprises a connectingsection 13 adjacent to thecoupling pin 5 which connects to a straightsecond section 14. The connectingsection 13 is configured such that the plane of the straight section 14 (i.e. the notional plane passing through the middle of thestraight section 14, parallel with its major surfaces) is offset from the pivot axis formed bycoupling pin 5. That is, the plane of the straight section does not pass through the pivot point formed by the coupling. As such, the connectingsection 13 angles thestraight section 14 back toward the bottom circumferential surface of thechannel 11. -
FIG. 3 also shows that, in the un-deployed position, the planes of each straight section of eachfin 2 lie substantially at a tangential plane to the curve of the recessed surface of thechannel 11 of the projectile body 3, with the middle of thestraight section 14 being located substantially at the tangent point. The planes of each straight section are indicated by dotted lines inFIG. 3 and pass through the centre of the planar or flat part of each fin'sstraight section 14. With this arrangement, the length of thestraight section 14 of each fin which can be stowed within the outer circumferential profile or boundary of the projectile is maximised. - The bottom surface of the
channel 11 further comprises a flattenedsection 12 adjacent to thecoupling 5 of eachfin 2, as can be seen inFIG. 1 . This allows the coupling pins 5 to be recessed radially toward the projectile's central axis, which in turn allows the fins to reach further around the projectile's body when in an un-deployed position. - In this embodiment each
fin 2 is additionally provided with atapered edge 15 along its distal end. The tapered edges 15 lie flush with the curvature of the sides of thechannel 11 when in the un-deployed position so as to help maximise the length of each fin, without extending beyond the outer circumferential profile of the projectile. - In use, the
projectile 1 is initially enclosed within a cartridge cover, which holds thefins 2 in their un-deployed position. When the weapon is fired, the propellant detonates, propelling the projectile 1 from its cartridge and along the weapon's barrel. When theprojectile 1 emerges from the weapon's barrel, thefins 2 are no longer constrained by the cover or weapon's barrel, allowing them to deploy under the bias of springs 6. - Initially, the
fins 2 are prevented from rearward movement as the rear edge of thefin 2 is biased against the rear rim ofmountings 7. However, the radially outward bias acts to rotate eachfin 2 out to its deployed position. Once in this position, the back of thefin 2 contacts its stoppingpin 9, thereby preventing further rotation of thefin 2. At the same time as the above, as thefins 2 radially move to their deployed position, a notch provided at the rear of the fin aligns with the rear rim of mounting 7, thereby allowing eachfin 2 to slide rearwardly along itscoupling pin 5 under the bias of its spring 6. This acts such that the notch slides over the rim of mounting 7 into an engaged position, with the surfaces of these formations mating with one another. Once in this engaged position, the width of eachfin 2 mates with a counter surface on the rim of mounting 7 providing a circumferential support surface on the projectile body for supporting eachfin 2. Once in this position, thefins 2 are effectively locked in their deployed position since they are biased rearwardly into this engaged position. Locking the fins into place in this manner has the advantage of providing enhanced stability during flight. - This configuration helps to provide improved accuracy over long ranges when compared to curved fins. This is because, for a given length, the fins extend further outward in a radial direction, allowing a greater proportion of their surface to interact with the major airflow past the projectile during its flight.
-
FIGS. 4 and 5 show a second embodiment of the invention, withFIG. 4 showing a rear cross-sectional view of the projectile with the fins in an un-deployed position, andFIG. 5 showing a perspective view of one of the fins. This second embodiment is similar to the first embodiment, except that eachfin 2 is configured to extend beyond the mounting of the next adjacent fin. Like features have been assigned the same reference numerals. - In this connection, as with the first embodiment, each
fin 2 is pivotally mounted to the projectile body 3 by apin 5 which forms a pivot. However, in this embodiment, thestraight section 15 of eachfin 2 extends around the circumference of the projectile body 3 by a distance sufficient to enable the distal end of thestraight section 15 of eachfin 2 to overlie the adjacent fin'spivot 5, when in the un-deployed position. To help facilitate this, flattenedsections 12, allow each fin'spivot 5 to be positioned closer to the longitudinal axis of the projectile body 3 than the curved surface of thechannel 11. - In addition, as shown in
FIG. 5 ,fin 2 is formed from a single piece of thin flat metal, which is bent into a generally L shaped form. Thus, the fins have a major portion formingstraight section 14 and a minor portion forming connectingsection 13. In this embodiment, the connectingsection 13 is provided with two opposinglugs 16 which form the mounting through which the fins pivotally couple to pin 5. The fin'sstraight section 14 is also provided with a narrowed region at its distal end which allows it to fit between thelugs 16 of theadjacent fin 2. This enables each fin to overlie its nextadjacent fin 2, allowing a longer fin shape to be accommodated. - It will be understood that the invention illustrated above shows an application only for the purposes of illustration. In practice the invention may be applied to many different configurations, the detailed embodiments being straightforward for those skilled in the art to implement.
- For example, although in the above examples, the straight sections of the fins have a uniform thickness defined by two substantially flat side surfaces, it will be understood that the fins could have an alternative cross sectional profile. For example, the fin may have a tapered construction, where the flat surfaces taper inward toward the plane defined though the middle of the straight/planar section of the fin.
Claims (20)
1. A projectile for a small arms weapon, the projectile comprising:
a projectile body;
a plurality of peripheral fins each pivotably coupled to the projectile body at a pivot for movement from a un-deployed position to a deployed position;
wherein each of the fins comprises a straight section and a connecting section connecting the straight section to the pivot and being configured so that the plane of the straight section is offset from the pivot axis.
2. A projectile according to claim 1 , wherein the plane of the straight section of each fin lies substantially at a tangent plane to the circumferential surface of the projectile body when in the un-deployed position.
3. A projectile according to claims 1 , wherein the straight section of each fin extends straight out from the projectile's body when in the deployed position.
4. A projectile according to claim 1 , wherein the projectile further comprises a channel formed around the circumference of the projectile body for receiving the plurality of fins when in the un-deployed position.
5. A projectile according to claim 4 , wherein the bottom surface of the channel further comprises a flat section adjacent to the pivot of each fin.
6. A projectile according to claim 1 , wherein, when in a deployed position, the plane of the straight section of each fin projects substantially radially outward.
7. A projectile according to claim 1 , wherein each fin is integrally formed.
8. A projectile according to claim 1 , wherein the length of the straight section of each fin is longer than the length of the connecting section.
9. A projectile according to claim 1 , wherein the straight section of each fin comprises at least one flat surface parallel to the plane of the straight section.
10. A projectile according to claim 1 , wherein the connecting section of each fin comprises a coupling connected to the respective pivot and a linking region between the coupling and the fin's straight section, the linking region being angled relative to the straight section.
11. A projectile according to claim 1 , wherein the projectile further comprises biassing means for biassing each fin toward its radially deployed position.
12. A projectile according to claim 11 , wherein the biassing means comprises a spring located at each pivot.
13. A projectile according to claim 1 , wherein the distal end of each fin comprises a tapered edge.
14. A projectile according to claim 1 , wherein each fin is configured to overlie the pivot of an adjacent fin.
15. A projectile for a small arms weapon, the projectile comprising:
a projectile body;
a plurality of peripheral fins each coupled to the projectile body at a pivot for rotation from a folded position to a deployed position, where each of the fins comprises a straight section and a connecting section connecting the straight section to the pivot, the straight and connecting sections being angled relative to one another so that, when in the folded position, each fin extends around a portion of the projectile body and, when in the deployed position, the straight section of each fin extends straight out from the projectile's body.
16. A projectile for a small arms weapon, the projectile comprising:
a projectile body;
a plurality of peripheral fins each pivotably coupled to the projectile body at a pivot for movement from a radially un-deployed position to a radially deployed position;
a channel formed around the circumference of the projectile body for receiving the plurality of fins when in the un-deployed position
wherein the pivot for each fin is positioned sufficiently towards the longitudinal axis of the projectile body to enable the distal end of each fin to overlie the pivot of the adjacent fin when the fins are in the un-deployed position.
17. A projectile according to claim 16 , wherein each fin has a generally L shaped form to define a major portion distal from the pivot and a minor portion proximal to said pivot.
18. A projectile according to claim 17 , wherein the major portion provides a substantially flat surface.
19. A projectile according to claim 17 wherein the minor portion of each said fin includes opposing lugs and each pivot comprises a pin located through said lugs.
20. A projectile according to claim 19 wherein the distal end of the major portion is shaped to enable it to fit between the lugs of an adjacent fin in the un-deployed position.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB1219468.4A GB201219468D0 (en) | 2012-10-30 | 2012-10-30 | Projectile |
GB1219468.4 | 2012-10-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20160223305A1 true US20160223305A1 (en) | 2016-08-04 |
Family
ID=47358842
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/068,341 Abandoned US20160223305A1 (en) | 2012-10-30 | 2013-10-31 | Projectile |
Country Status (2)
Country | Link |
---|---|
US (1) | US20160223305A1 (en) |
GB (1) | GB201219468D0 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10788297B2 (en) * | 2015-09-29 | 2020-09-29 | Nexter Munitions | Artillery projectile with a piloted phase |
US11428515B2 (en) * | 2017-10-04 | 2022-08-30 | Nexter Munitions | Fin blocking device and projectile having such a device |
US20220290953A1 (en) * | 2019-09-03 | 2022-09-15 | Cta International | Telescoped ammunition comprising a sub-calibre projectile stabilized by a deployable tail fin |
-
2012
- 2012-10-30 GB GBGB1219468.4A patent/GB201219468D0/en not_active Ceased
-
2013
- 2013-10-31 US US14/068,341 patent/US20160223305A1/en not_active Abandoned
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10788297B2 (en) * | 2015-09-29 | 2020-09-29 | Nexter Munitions | Artillery projectile with a piloted phase |
US11428515B2 (en) * | 2017-10-04 | 2022-08-30 | Nexter Munitions | Fin blocking device and projectile having such a device |
US20220290953A1 (en) * | 2019-09-03 | 2022-09-15 | Cta International | Telescoped ammunition comprising a sub-calibre projectile stabilized by a deployable tail fin |
Also Published As
Publication number | Publication date |
---|---|
GB201219468D0 (en) | 2012-12-12 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |