Technical field
[0001] The present invention generally relates to projectiles. More specifically, it is
related to non-lethal projectiles.
Background
[0002] Aerodynamic projectiles, such as rubber bullets and paintballs, are commonly used
for training, recreational play, as well as for non-lethal law enforcement purposes.
These projectiles typically consist of a spherical or cylindrical shell provided with
a rubber tip, or filled with a non-lethal material, such as marking liquid or irritants,
and is generally propelled from a rifle by compressed gas.
[0003] One of the primary challenges in designing such aerodynamic projectiles is ensuring
that they travel in a predictable and stable trajectory. Unstable flight paths can
lead to inaccurate or unsafe projectile behavior, such as ricocheting, collateral
damage or failing to achieve the desired effect on the target. Additionally, the impact
force and range of the projectile is greatly affected by its aerodynamic properties,
such as its drag coefficient and spin characteristic.
[0004] Previous attempts to improve the aerodynamic properties of projectiles have included
modifying their shape, surface texture, and weight distribution. For example, some
projectiles have been designed with fins or flanges to stabilize their flight path,
while others have used weighted cores to increase their momentum.
[0005] However, these approaches have often been limited in their effectiveness, due to
factors such as manufacturing complexity, or simply failing to achieve a desirable
precision and range. Therefore, there is a need for an improved aerodynamic projectile
design that can address these issues and provide enhanced accuracy, stability, predictability
and range.
Summary
[0006] The herein disclosed technology seeks to at least partly mitigate, alleviate or eliminate
one or more of the above-mentioned deficiencies and disadvantages in the prior art.
In particular, it is an object to provide an improved non-lethal projectile having
improved aerodynamic properties and flight characteristics. The inventors has realized
a new way of improving the aerodynamic properties of the projectile as well as improving
how the projectile interacts with the barrel of the rifle to improve both accuracy
and range.
[0007] Various embodiments of the disclosed invention are defined below and in the accompanying
independent and dependent claims.
[0008] According to a first aspect, there is provided a non-lethal projectile. The projectile
comprises a front member having a forward facing portion. The projectile further comprises
a cylindrical sidewall member having an outer surface and an inner surface. The projectile
further comprises a partition member arranged between the front member and the sidewall
member. The partition member and the inner surface of the sidewall member forms an
open cavity having an open end opposing the partition member. The sidewall member
comprises a first portion abutting the partition member, and a second portion away
from the partition member. The second portion is tapered from a first end abutting
the first portion of the sidewall member towards an opposite second end. The projectile
further comprises a plurality of rear fins protruding from the outer surface of the
sidewall member. The projectile further comprises a rotation generating member arranged
within the open cavity. The rotation generating member is configured to generate a
rotary motion of the projectile when subject to a forward driving force.
[0009] The wording "non-lethal projectile", herein refers to a projectile which intends
to minimize a (permanent) personal damage to a target. The non-lethal projectile may
for instance be used in training, in recreational play, or by law enforcement e.g.
in crowd control or to temporarily immobilize a suspect. The non-lethal projectile
may throughout the present disclosure also be referred to as aerodynamic projectile,
or just projectile.
[0010] By relative wordings such as "forward facing" or "front", it is herein meant in relation
to a direction of travel of the projectile, i.e. towards a leading edge of the projectile.
In contrast, the wording "rear" herein refers to a back of the projectile, i.e. towards
a trailing edge of the projectile.
[0011] The wording "open cavity", herein refers to a space having a solid sidewall, one
closed end, and one open end. In contrast, the wording "closed cavity" as used herein,
refers to a space entirely enclosed by solid walls.
[0012] A possible associated advantage of having the rotation generating member and the
rear fins is that a rotational speed of the projectile may be increased. An effect
of increased rotational speed is that the accuracy and range of the projectile is
also improved, thereby increasing the probability of hitting the intended target.
The plurality of rear fins may further improve the stability of the projectile during
flight.
[0013] An effect of having a tapered end of the projectile is that a drag coefficient of
the projectile may be reduced.
[0014] The projectile may further comprise a plurality of front fins protruding from the
forward facing portion of the front member and/or from the outer surface of the sidewall
member. In particular, the plurality of front fins may be arranged forward of the
plurality of rear fins. For example, the plurality of front fins may be arranged at
the first portion of the sidewall member while the plurality of rear fins are arranged
at the second portion of the sidewall member.
[0015] A possible advantage associated with the plurality of front fins is that the rotational
speed of the projectile may be even further improved. Further, the plurality of front
fins together with the plurality of rear fins may interact with a rifling of the barrel
used to fire the projectile to thereby promote even more rotation of the projectile.
Even further, having both front and rear fins may be advantageous in that it improves
the stability of the projectile as it travels through the barrel, by reducing the
possibility of a pitch and yaw rotation of the projectile.
[0016] Each rear fin of the plurality of rear fins and/or each front fin of the plurality
of front fins may extend at a transverse angle to a central axis of the projectile
about the outer surface of the sidewall member.
[0017] By having the plurality of rear fins and/or the plurality of front fins at an angle,
the fins, when travelling through the air, imparts further rotational motion of the
projectile.
[0018] An outermost portion of the plurality of rear fins and/or the plurality of front
fins may define an outermost circumference of the projectile.
[0019] A possible associated advantage of having the fins forming the outermost portion
of the projectile is that a contact area between the barrel and the projectile can
be reduced, thus reducing a friction there between. This may in turn lead to a higher
exit velocity. A higher exit velocity may be utilized in increasing a range of the
projectile. Alternatively, the amount of compressed gas that is to be released when
firing the projectile can be reduced, while still maintaining a sufficient exit velocity.
Thereby, the stored energy in the rifle can last longer before needing to be refilled.
[0020] The plurality of rear fins may be between 2 and 32 rear fins. The plurality of front
fins may be between 2 and 32 front fins. Preferably, the plurality of rear fins and/or
the plurality of front fins may be 8 or 16, as it forms a good match with the rifling
of many barrels, which typically has 8 grooves.
[0021] The projectile may further comprise a fill nipple for providing the fill to the closed
cavity of the front member. The fill nipple may be arranged at a center of the rotation
generating member.
[0022] Having the fill nipple arranged at a rear of the projectile may be advantageous in
that it has little to no negative effect of the aerodynamics of the projectile. Further,
a risk of the projectile getting jammed in a magazine or the rifle (in particular
when the projectile is moving from the magazine to the rifle) can be reduced, as compared
to having a fill nipple arranged on the front member. This is because the resulting
fill nipple is generally surrounded with sharp edges that can get caught against edges
or other surfaces in the magazine or the rifle. It may further be advantageous in
that the risk of having air bubbles formed in the closed cavity may be reduced, where
air bubbles in the closed cavity can have a negative effect on the flight characteristics
of the projectile.
[0023] The forward facing portion of the front member may comprise a plurality of grooves.
[0024] A possible associated advantage of having the grooves may be further improved flight
characteristics, e.g. due to improved flight stability and rotational speed, caused
by the grooves.
[0025] A further scope of applicability of the present disclosure will become apparent from
the detailed description given below. However, it should be understood that the detailed
description and specific examples, while indicating some variants of the present inventive
concept, are given by way of illustration only, since various changes and modifications
within the scope of the inventive concept will become apparent to those skilled in
the art from this detailed description.
[0026] Hence, it is to be understood that this inventive concept is not limited to the particular
steps of the methods described or component parts of the systems described as such
method and system may vary. It is also to be understood that the terminology used
herein is for purpose of describing particular embodiments only and is not intended
to be limiting. It must be noted that, as used in the specification and the appended
claim, the articles "a", "an", "the", and "said" are intended to mean that there are
one or more of the elements unless the context clearly dictates otherwise. Thus, for
example, reference to "a member" or "the member" may include several devices, and
the like. Furthermore, the words "comprising", "including", "containing" and similar
wordings do not exclude other elements or steps.
Brief description of the drawings
[0027] The above and other aspects of the present inventive concept will now be described
in more detail, with reference to appended drawings showing variants of the present
inventive concept. The figures should not be considered limiting the invention to
the specific variant; instead, they are used for explaining and understanding the
inventive concept.
[0028] As illustrated in the figures, the sizes of layers and regions are exaggerated for
illustrative purposes and, thus, are provided to illustrate the general structures
of variants of the present inventive concept. Like reference numerals refer to like
elements throughout.
Figure 1A to 1F illustrates different views of an example of a projectile according
to some embodiments of the present disclosure.
Figure 2A and 2B illustrates different views of a further example of the projectile
according to some embodiments of the present disclosure.
Figure 3A and 3B illustrates different views of a further example of the projectile
according to some embodiments of the present disclosure.
Figure 4A and 4B illustrates different views of a further example of the projectile
according to some embodiments of the present disclosure.
Figure 5A and 5B illustrates different views of two further examples of the projectile
according to some embodiments of the present disclosure.
Figure 6A and 6B illustrates different views of a further example of the projectile
according to some embodiments of the present disclosure.
Figure 7A and 7B illustrates different views of a further example of the projectile
according to some embodiments of the present disclosure.
Figure 8A-8C illustrates an example of the projectile according to some embodiments
prior to assembling.
Detailed description
[0029] The present inventive concept will now be described more fully hereinafter with reference
to the accompanying drawings, in which some variants of the inventive concept are
shown. This inventive concept may, however, be implemented in many different forms
and should not be construed as limited to the variants set forth herein; rather, these
variants are provided for thoroughness and completeness, and fully convey the scope
of the present inventive concept to the skilled person.
[0030] It is also to be understood that the terminology used herein is for purpose of describing
particular embodiments only, and is not intended to be limiting. It should be noted
that, as used in the specification and the appended claim, the articles "a", "an",
"the", and "said" are intended to mean that there are one or more of the elements
unless the context clearly dictates otherwise. Thus, for example, reference to "a
unit" or "the unit" may refer to more than one unit in some contexts, and the like.
Furthermore, the words "comprising", "including", "containing" do not exclude other
elements or steps. It should be emphasized that the term "comprises/comprising" when
used in this specification is taken to specify the presence of stated features, integers,
steps, or components. It does not preclude the presence or addition of one or more
other features, integers, steps, components, or groups thereof. The term "and/or"
is to be interpreted as meaning "both" or each as an alternative.
[0031] It will also be understood that, although the term first, second, etc. may be used
herein to describe various elements or features, these elements should not be limited
by these terms. These terms are only used to distinguish one element from another.
For example, a first portion could be termed a second portion, and, similarly, a second
portion could be termed a first portion, without departing from the scope of the embodiments.
The first portion and the second portion are both portions, but they are not the same
portion.
[0032] A non-lethal projectile according to the present inventive concept will now be described
with reference to figure 1A to 8C. Fig. 1A to 8C illustrates, by way of example, a
number of embodiments. It should however be noted that features of the disclosed embodiments
may be suitably combined with each other in any manner apparent to anyone of ordinary
skill in the art, such that one or more features of one embodiment may also be considered
to be disclosed in relation to another embodiment. It should further be appreciated
that the claimed subject matter is not limited to the disclosed examples of the figures.
[0033] Figures 1A to 1F illustrates, by way of a first example, a non-lethal projectile
100 according to some embodiments. More specifically, Fig. 1A is a first perspective
view of the projectile 100 in a generally front facing direction. Fig. 1B is a second
perspective view of the projectile 100 in a generally rear facing direction. Fig.
1C is a front view of the projectile 100. Fig. 1D is a rear view of the projectile
100. Fig. 1E is a side view of the projectile 100. Fig. 1F is a side view of the projectile
without any fins for illustrating the tapering of a second portion 104b of a sidewall
member 104 of the projectile.
[0034] Referring to Figs. 1A-1F, the projectile 100 comprises a front member 102 and a cylindrical
sidewall member 104. The front member 102 constitutes the leading portion of the projectile
100 as it travels through the air. The sidewall member 104 constitutes a trailing
portion of the projectile. The front member 102 and the sidewall member 104 are arranged
along a central axis AC of the projectile 100. The sidewall member 104 may be seen
as a cylindrical sidewall extending rearwards from a rear of the front member 102,
along the central axis AC. The front member 102 and the sidewall member 104 together
forms a main body of the projectile 100. The projectile 100 may be manufactured as
a single piece of material. Alternatively, the front member 102 and the sidewall member
104 may be manufactured as two separate pieces which can be joined together, as will
be further exemplified and described below in connection with Fig. 8A-8C.
[0035] The projectile 100 further comprises a partition member 102b. The partition member
102b is arranged between the front member 102 and the sidewall member 104. The partition
member 102b should be understood as an inner wall separating the front member 102
from the sidewall member 104. The partition member 102b may also be referred to as
a divider. The partition member 102b may be an integral part of the front member 102.
Thus, the partition member 102b may constitute a rear facing portion or surface of
the front member 102. Alternatively, the partition member 102b may be an integral
part of the sidewall member 104, as illustrated in Fig. 8A. Thus, the partition member
102b may constitute a front facing portion or surface of the sidewall member 104.
[0036] The front member 102 comprises a forward facing portion 102a. The forward facing
portion 102a should be seen as the surface of the front member 102 arranged towards
the direction of travel. As illustrated herein, the forward facing portion 102a of
the front member 102 has a hemispherical shape. In some embodiments, the forward facing
potion 102a may have other shapes, such as a blunt shape, a cylindrical shape, a conical
shape, or a conical shape with a blunt tip.
[0037] In some embodiments, the front member 102 comprises a protrusion (not shown) at a
front/top end of the forward facing portion 102a. The protrusion may be a hemispherical
protrusion that extends 0,1-2 mm from the outer surface of the forward facing portion
102a. Thereby the projectile may be provided with a smaller contact surface when traveling
through the magazine, reducing the risk of jamming within the magazine without increasing
the risk of jamming when moving from the magazine to the barrel chamber since the
protrusion is smooth.
[0038] The front member 102 may in some embodiments be made of a solid material. The front
member 102 may for instance be made of an elastic material, such as rubber. As another
example, the front member 102 may be made of a deformable material, such as a foam
material.
[0039] In some embodiments, the front member encloses a closed cavity 126. In other words,
the front member 102 may be hollow. The closed cavity may be formed by the walls of
the front member 102 and the partition member 102b. The closed cavity 126 may be provided
with a fill. The fill may be a liquid, a gas, or a solid, such as a powder. In case
of having a closed cavity 126, the front member 102 is preferably made of a frangible
material so as to break on impact. The fill may for instance be an irritant agent,
such as pepper spray or tear gas. In another example, the fill may be an inflammatory
or noxious agent such as malodorants, which induce nausea and/or vomiting. In yet
another example, the fill may be a marking compound. The marking compound may mark
the target in the visible, ultraviolet or infrared spectrum. Alternatively, the marking
compound may be a DNA marker. In yet another example, the closed cavity may comprise
a GPS tracker. In yet another example, the closed cavity may comprise an explosive
device. The projectile 100 may be compatible with other suitable fills as well.
[0040] The projectile 100 may further comprise a fill nipple 128 for providing the fill
to the closed cavity 126 of the front member 102. The fill nipple 128 may be arranged
at a center of a rotation generating member 114 (further described below) as illustrated
in Fig. 1D. The fill nipple 128 may then extend though the center of the rotation
generating member 114 and the partition member 102b so that it reaches the closed
cavity 126. Alternatively, the fill nipple 128 may be provided at a center of the
forward facing portion 102a of the front member 102. However, having the fill nipple
128 arranged in the back may be advantageous in that the forward facing portion 102a
of the front member 102 can be made to have a smooth surface, which improves the aerodynamic
properties of the projectile 100 as well as minimizing the risk of jamming due to
projectiles getting stuck in the rifle or magazine.
[0041] The cylindrical sidewall member 104 comprises a first portion 104a and a second portion
104b. The first portion abuts the partition member 102b (or the front member 102),
and the second portion 104b is arranged away from the partition member 102b, as seen
along the direction of travel, or along a central axis AC (as illustrated in Fig.
1). The first portion 104a defines a portion of the sidewall member 104 having a constant
outer diameter. The second portion 104b is instead tapered from a first end abutting
the first portion 104a of the sidewall member 104 towards an opposite second end.
In other words, the second portion 104b may have a frustoconical shape having a larger
outside diameter at the first end than at the opposite second end. The tapering of
the second portion 104b of the sidewall member 104 is further described below in connection
with Fig. 1F.
[0042] The cylindrical sidewall member 104 has an inner surface 108 and an outer surface
106. The inner surface 108 may comprise a first inner sub surface 108a corresponding
to the inner surface of the first portion 104a of the sidewall member 104 and a second
inner sub surface 108b corresponding to the inner surface of the second portion 104b
of the sidewall member 104. Correspondingly, the outer surface 106 may comprise a
first outer sub surface 106a corresponding to the outer surface of the first portion
104a of the sidewall member 104 and a second outer sub surface 106b corresponding
to the outer surface of the second portion 104b of the sidewall member 104.
[0043] The projectile 100 further comprises a plurality of rear fins 110. The plurality
of rear fins 110 protrude from the outer surface 106 of the sidewall member 104. As
in the illustrated example, the plurality of rear fins may be arranged on the second
portion 104b of the sidewall member 104. Alternatively, the plurality of rear fins
110 may be arranged on the first portion 104a of the sidewall member 104. Alternatively,
the plurality of rear fins may extend over at least a part of both the first and second
portion 104a, 104b of the sidewall member 104. For example, the rear fins may extend
over the entire length of the sidewall member 104.
[0044] The wording "protruding from" a surface should when herein used in connection with
the rear fins of the projectile be construed as projecting outwards in a radial direction
of the sidewall member 104.
[0045] The wording "extending" when herein used in connection with fins of the projectile
100 should be construed as a lengthwise extension of the fin (i.e. mainly in an axial
direction of the projectile 100), as opposed to a width extension of the fin (i.e.
mainly in an angular direction around the projectile 100).
[0046] Preferably, the rear fins of the plurality of rear fins 110 are evenly distributed
around the circumference of the sidewall member 104. In the illustrated example, the
projectile 100 comprises 16 rear fins. It should however be appreciated that the projectile
100 may comprise any number of rear fins, such as any number between 2 and 32. Preferably,
the projectile 100 comprises 8 or 16 rear fins.
[0047] The rear fins of the plurality of rear fins 110 may protrude from the outer surface
106 of the sidewall member 104 at a ramp angle, as denoted by the angle
δ in Fig. 1E. Thus, the rear fin gradually protrudes more and more from the outer surface
106 of the sidewall member 104 from a first edge 118a to a second edge 118b.
[0048] In the illustrated example, the rear fins of the plurality of rear fins 110 has its
outermost portion (i.e. in radial direction) at the second edge 118b. However, in
some embodiments, the outermost portion may be arranged at an intermediate position
between the first edge 118a and the second edge 118b. Put differently, the protrusion
of the rear fins need not follow a straight line, as depicted herein. The protrusion
may for instance first increase and later decrease, or be constant along the extension
of the rear fin, in relation to the central axis of the projectile 100.
[0049] Having the plurality of rear fins 110 arranged on the tapered second portion 104b
of the sidewall member 104 allows the rear fins to protrude to a greater extent in
relation to the surface of the projectile 100 on which it is arranged, thus having
a greater effect on the rotation of the projectile 100.
[0050] The projectile 100 further comprises a plurality of front fins 112. The plurality
of front fins 112 may protrude from the forwards facing portion 102a of the front
member 102 as illustrated herein. The plurality of front fins 112 may be evenly distributed
around the circumference of the projectile 100 as shown in Fig. 1C. As shown in Fig.
1E, the plurality of front fins 112 may be arranged at a rear end of the front member
102. Alternatively, or in combination, the plurality of front fins 112 may protrude
from the outer surface of the sidewall member 104 (or more specifically from the first
portion 104a of the sidewall member 104). The projectile 100 may comprises the same
number of rear fins as front fins, in this case 16. However, the projectile 100 may
comprise any number of front fins between 2 and 32. Preferably, the projectile 100
comprises 8 or 16 front fins. Further, the projectile 100 may comprise a different
number of front and rear fins, an example of which is illustrated in Fig. 3B.
[0051] The inner surface 108 together with the partition member 102b forms an open cavity
124 of the projectile 100. The open cavity 124 has an open end opposing the partition
member 102b, i.e. towards a rear of the projectile 100. The sidewall member 104 may
thus be seen as a hollow skirt portion of the projectile 100.
[0052] As shown in fig. 1B, the projectile 100 further comprises a rotation generating member
114. The rotation generating member 114 is arranged within the open cavity 124. More
specifically, the rotation generating member may be arranged on the partition member
102b. The rotation generating member 114 (or means for generating a rotational motion
of the projectile 100) is configured to generate a rotary motion of the projectile
100 around its central axis, AC, when subject to a forward driving force. The forward
driving force (also referred to as a propulsive force) may be caused by a compressed
gas, such as air, being released to fire the projectile. As in the illustrated example,
the rotation generating member 114 may be a propeller-like structure as illustrated
herein. However, as is readily understood by the skilled person, other types of structures
which drives a rotation of the projectile 100 in response to a propulsive force may
be used as well. The skirt-like structure of the sidewall member 104 that surrounds
the rotation generating member 114 may serve the purpose of concentrating the forward
driving force of the compressed air when the projectile 100 travels through the rifle,
and, once the projectile 100 travels through the air, preventing the oncoming airflow
from engaging the rotation generating member 114 to inhibit the rotary motion of the
projectile 100.
[0053] In the illustrated example, the rotation generating member 114 comprises a plurality
of rotor blades 120. Herein, the rotation generating member 114 comprises 8 rotor
blades 120. However, any number of rotor blades between 2 and 32 may be used. An angle
of attack of the rotor blades of the plurality of rotor blades may be between 5 and
75 degrees, preferably 10 and 50 degrees, or more preferably 30 to 45 degrees.
[0054] Turning again to Fig. 1D, and in particular to the zoomed-in portion of a rear fin.
Each rear fin of the plurality of rear fins 110 comprises a first flank surface 116a
and a second flank surface 116b. The first and second flank surfaces 116a, 116b may
also be referred to as a first and second sidewall of the fins. The first and second
flank surfaces 116a, 116b may form a respective angle (herein denoted α and β) to
the outer surface 106 of the sidewall member 104. In the illustrated example, the
first flank surface 116a is perpendicular to the outer surface 106 of the sidewall
member 104. In other words, the angle α = 90 degrees. The angle β of the second flank
surface 116b is different from the angle of the first flank surface 116a. For example,
the angle β is smaller than 90 degrees. More specifically, the angle β may be between
75 and 90 degrees. Similarly to the rear fins, the plurality of front fins 112 may
also have a first and second flank surface formed at angles to the outer surface 106
the same way as described above.
[0055] With reference to Fig. 1E, each rear fin of the plurality of rear fins 110 extend
at a transverse angle to the central axis AC of the projectile 100 about the outer
surface 106 of the sidewall member 104. In other words, the rear fins are angled in
relation to a direction of travel of the projectile 100. Thus, a first edge 118a of
a rear fin of the plurality of rear fins 110 is offset, in a circumferential direction
of the projectile 100, from a second edge 118b of the rear fin. The plurality of front
fins 112 (if present) may also extend at a transverse angle to the central axis AC
of the projectile 100. The transverse angle of the plurality of front fins 112 may
be the same or different from the transverse angle of the plurality of rear fins 110.
Having the plurality of rear fins 110 (and/or the plurality of front fins 112) provided
at a transverse angle assist in promoting the rotary motion of the projectile 100
as it travels through the air. In some embodiments, the plurality of rear fins 110
(and/or the plurality of front fins 112) may have a curvature as they traverse the
length of the sidewall member 104 (as compared to extending along a straight line
as herein illustrated).
[0056] As further illustrated in Fig. 1E, the plurality of rear fins 110 may be offset in
the circumferential direction from the plurality of front fins 112 such that they
extend along different lines. Put differently, a rear fin of the plurality of rear
fins 110 may extend along a first axis denoted A1. A corresponding front fin of the
plurality of front fins 112 may extend along a second axis denoted A2. The first and
second axis A1, A2 may be parallel, but different axes. In other words, the first
and second axis A1, A2, is in this case not coincident. In some embodiments, the first
and second axis A1, A2, may be coincident, as will be further described below in connection
with Fig. 4B. Having the front wings offset from each other may have an advantageous
effect of an improved interaction with the rifling of the barrel.
[0057] Turning to Fig. 1F, the projectile 100 is shown without any front and rear fins for
the purpose of illustrating certain aspects of the main body of the projectile 100.
[0058] As described above, the second portion 104b of the sidewall member 104 is tapered.
The tapering of the second portion 104b may be defined by an angle, herein denoted
by γ, which the tapered portion deviates from cylindrical first portion 104a of the
sidewall member 104. The angle γ may be 5 to 15 degrees, or more preferably 10 degrees.
Put differently, the second portion 104b of the sidewall member 104 has a first diameter
D1 at the end abutting the second portion 104b and a second diameter D2 at the opposite
end, where the second diameter D2 is smaller than the first diameter D1. It goes without
saying that the illustrated angle γ, (and thus also the illustrated relationship between
the first and second diameters D1, D2) are to be seen merely as an illustrative example.
Other relative dimensions of the projectile 100 may be possible as well within the
scope of the present inventive concept. It should also be appreciated that the tapering
of the second portion 104b need not to be constant. For instance, the tapering may
gradually increase or decrease towards the distal end of the second portion 104b.
[0059] The first diameter D1 should be seen as the largest diameter of the main body of
the projectile 100. The first diameter D1 may thus be set based on a caliber of the
rifle used to fire the projectile 100. The projectile 100 described herein may for
instance be designed for .43cal or .68cal. However, an outermost portion (i.e. in
the radial direction) of the plurality of rear fins 110 and (if present also) the
plurality of front fins 112 may define an outermost circumference of the projectile
100. This is illustrated in Fig. 1E, by the diameter denoted D0 being larger than
the first diameter D1. The diameter D0 may for instance be 0.6 to 2.0 mm larger than
D1. In other words, the outermost portion of the plurality of rear fins 110 (and plurality
of front fins 112) may protrude 0.3 to 1.0 mm out from the outermost portion of the
main body of the projectile 100.
[0060] Fig. 1F further illustrates that the front member 102 has a first height H1, the
first portion 104a of the sidewall portion 104 has a second height H2 and the second
portion 104b of the sidewall portion 104 has a third height H3. It goes without saying
that the different heights H1, H2, H3 of the projectile 100 may be selected differently
without departing from the present inventive concept. For example, even though in
the illustrated example the second height H2 is larger than the third height H3, in
some embodiments, the third height may be made equal to or larger than the second
height. Thus a larger portion of the projectile 100 may be tapered. In some embodiments,
the combined height of the first and second portion 104a, 104b, should be larger than,
or equal to the first height H1. This may have an advantageous effect of the stability
of the projectile 100.
[0061] In the following, with reference to Fig. 2A to Fig. 8C, different variants of the
projectile 100 will be described. As is readily understood by the skilled person,
any principles, aspects or features described in connection with one example embodiment
are applicable also to the other example embodiments if not stated otherwise.
[0062] Figure 2A and 2B illustrates, by way of a second example, a projectile 200 according
to some embodiments. More specifically, Fig. 2A is a perspective view of the projectile
200 in a generally rear facing direction and Fig. 2B is a side view of the projectile
200. In comparison to the projectile 100 as described above in connection with Fig.
1A to 1F, the projectile 200 as presently described has no plurality of front fins.
Such an projectile 200 may be advantageous in that it to some extent allows for a
simpler manufacturing process, while still achieving improved flight characteristics
due to the rotation generating member 114, the plurality of rear fins 110 and the
tapered second portion 104b of the sidewall member 104.
[0063] In the illustrated example of Fig. 2A and 2B, the plurality of rear fins 110 defines
the outermost circumference of the projectile 200, as in the example of Figs. 1A to
1F. However, in some embodiments, an outer surface of the plurality of rear fins 110
may coincide with the outer surface 106 of the first portion 104a of the sidewall
member 104. Put differently, the outermost circumference of the projectile 200 may
be defined by the first portion 104a of the sidewall member 104 and the outer surface
of the plurality of rear fins 110.
[0064] Figure 3A and 3B illustrates, by way of a third example, a projectile 300 according
to some embodiments. More specifically, Fig. 3A is a perspective view of the projectile
300 in a generally rear facing direction and Fig. 3B is a side view of the projectile
300. In comparison to the projectile 100 as described above in connection with Fig.
1A to 1F, the projectile 300 as presently described shows a case where the projectile
300 has a different number of front fins compared to the number of rear fins. In the
present example, the projectile 300 has eight front fins 112 and sixteen rear fins
110. This combination of front and rear fins has proven to achieve especially good
results in terms of accuracy. However, as is readily understood by the skilled person,
other combinations of front and rear fins may be applicable as well.
[0065] Figure 4A and 4B illustrates, by way of a fourth example, a projectile 400 according
to some embodiments. More specifically, Fig. 4A is a perspective view of the projectile
400 in a generally rear facing direction and Fig. 4B is a side view of the projectile
400. In comparison to the projectile 100 as described above in connection with Fig.
1A to 1F, the projectile 400 as presently described illustrates a case where the plurality
of rear fins 110 are aligned with the plurality of front fins 112 so as to extend
along a common axis.
[0066] More specifically, a rear fin of the plurality of rear fins 110 and a corresponding
front fin of the plurality of front fins 112 may extend along common third axis A3.
The front and rear fin may in such case be seen as a single fin being interrupted
at an intermediate portion, so as to form two separate fins with a lengthwise offset
there between.
[0067] Fig. 5A illustrates, by way of example, a variant of the projectile 300 as described
above in connection with Fig. 3A and 3B. The projectile 300' illustrated herein shows
an example where the plurality of front fins 112 are arranged on the first portion
104a of the sidewall member 104, instead of on the front member 102. Preferably, the
plurality of front fins 112 are arranged towards the end of the first portion 104a
abutting the front member 102 so as to provide a distance between the plurality of
front fins 112 and the plurality of rear fins 110.
[0068] Similarly, Fig. 5B illustrates, by way of example, a variant of the projectile 100
as described above in connection with Fig. 1A to 1F. The plurality of front fins 112
of the projectile 100' illustrated herein, are also arranged on the first portion
104a of the sidewall member 104.
[0069] Figure 6A and B illustrates, by way of a sixth example, a projectile 600 according
to some embodiments. More specifically, Fig. 6A is a perspective view of the projectile
600 and Fig. 6B is a front view of the projectile 600.
[0070] The plurality of front fins 112 of the projectile 600, as compared to the projectile
300 of Fig. 3A and 3B, extends over a greater portion of the front member 102. Having
the longer front fins, as illustrated herein, may promote even further rotary motion
of the projectile 600.
[0071] Figure 7A and 7B illustrates, by way of a seventh example, a projectile 700 according
to some embodiments. More specifically, Fig. 7A is a perspective view of the projectile
700 and Fig. 7B is a front view of the projectile 700.
[0072] The projectile 700 further comprises a plurality of grooves 130. The plurality of
grooves 130 are arranged on the forward facing portion 102a of the front member 102.
The plurality of grooves 130 may be understood as a plurality of depressions in the
surface of the front member 102.
[0073] Each groove of the plurality of grooves 130 may be provided at a transverse angle
to the central axis of the projectile 700. Put differently, a forward end of a groove
of the plurality of grooves 130 may be offset in a circumferential direction from
a rear end of the groove, as can be seen in the front view of Fig. 7B.
[0074] The projectile 700 comprises 16 grooves. However, the projectile 700 may comprise
8 grooves, or any number of grooves between 2 and 32.
[0075] The projectile 700 as illustrated herein comprises both a plurality of front fins
112 and the plurality of grooves 130. However, in some embodiments, the projectile
700 comprises only the plurality of grooves 130 (and no front fins 112).
[0076] However, in some embodiments, the plurality of grooves 130 are in the form of indentations
or dimples (not shown), such as e.g., hemispherical indentations or dimples, provided
on at least portion of the outer surface of the front member 102. Thus, only a portion
of the outer surface of the front member 102 may be covered with the plurality of
indentations or dimples, or the entire surface of the front member 102 may be covered
by the plurality of indentations or dimples. The plurality of indentations or dimples
may accordingly be evenly distributed on the outer surface of the front member 102.
[0077] Fig. 8A-C illustrates an example of the projectile 100', according to some embodiments,
prior to assembling. As described above, the front member 102 and the sidewall member
104 may be provided as two separate parts (as illustrated herein) which may be joined
together. The sidewall member 104 is shown in Fig. 8A. Fig. 8B and 8C illustrates
two different examples of the front member 102.
[0078] The front member 102 may be a hollow shell for forming the closed cavity 126 as shown
in Fig. 8B. In the illustrated example, the partition member 102b is provided as an
integral part of the sidewall member 104. Thus, the closed cavity is formed by the
front member 102 and the partition member 102b once the front member 102 is attached
to the sidewall member 104.
[0079] The front member 102 and the sidewall member 104 is provided with a respective mating
interface for joining them together in a secure and reliable way. As realized by the
skilled person, the mating interface may to some extend be designed based on the manner
in which the front member 102 and the sidewall member 104 are to be joined together,
e.g. by solvent welding, ultrasonic welding, or use of adhesive. As an example, the
front member 102 may comprise a rim 134 extending around an inside of the front member
102 for forming a closed seal against the partition member 102b. Further, the sidewall
member 104 may be provided with a notch 132 around an outer edge of the sidewall member
104 for allowing the front member 102 to partly overlap the sidewall member 104 when
attached together.
[0080] In the presently disclosed configuration, the closed cavity 126 of the projectile
100' is filled from the rear of the projectile 100', after the front member 102 and
the sidewall member 104 has been joined together. Thus, the fill nipple 128 extends
through the partition member 102b as illustrated herein. Alternatively, the closed
cavity 126 may be filled after joining of the front member 102 and the sidewall member
104 though a fill nipple provided on the front member 102. In yet another alternative,
the front member 102 may be filled prior to being joined with the sidewall member
104. In such case (as illustrated in Fig. 8C), the front member 102 may be sealed
by a partition member 102b attached to the front member 102 for forming the closed
cavity. The rim 134 may form part of the partition member 102b or be attached thereto.
It should however be appreciated that the partition member 102b may constitute two
or more elements. For instance, a first part of the partition member 102b may be arranged
on the sidewall member 104, e.g. as illustrated in Fig. 8A, and a second part of the
partition member 102b may be arranged on the front member 102, e.g. as illustrated
in Fig. 8C. When assembling, the two parts of the partition member 102 may be joined
together.
[0081] The sidewall member 104 may be made of a rigid plastic which do not break by the
pressure used when firing the projectile 100'. Accordingly, the sidewall member 104
may be made from a suitable polymeric material or composite material.
[0082] The front member 102, or at least the forward facing portion 102a of the front member
102 may be made of a frangible material so as to break on impact, but not break or
dissolve during storage or handling. Accordingly, the front member 102, or at least
the forward facing portion 102a, may be made from a suitable polymeric material or
composite material.
[0083] Preferably, the materials of the projectile are biodegradable.
[0084] Additionally, variations to the disclosed variants can be understood and effected
by the skilled person in practicing the claimed invention, from a study of the drawings,
the disclosure, and the appended claims.
1. A non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) comprising a front
member (102) having a forward facing portion (102a), a cylindrical sidewall member
(104) having an outer surface (106) and an inner surface (108), and a partition member
(102b) arranged between the front member (102) and the sidewall member (104),
wherein the partition member (102b) and the inner surface (108) of the sidewall member
(104) forms an open cavity (124) having an open end opposing the partition member
(102b),
wherein the sidewall member (104) comprises a first portion (104a) abutting the partition
member (102b), and a second portion (104b) away from the partition member (102b),
wherein the second portion (104b) is tapered from a first end abutting the first portion
(104a) of the sidewall member (104) towards an opposite second end,
wherein the projectile (100, 100', 200, 300, 300', 400, 600, 700) further comprises:
a plurality of rear fins (110) protruding from the outer surface (106) of the sidewall
member (104), and
a rotation generating member (114) arranged within the open cavity (124), the rotation
generating member (114) being configured to generate a rotary motion of the projectile
(100, 100', 200, 300, 300', 400, 600, 700) when subject to a forward driving force.
2. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
claim 1, wherein the projectile (100, 100', 200, 300, 300', 400, 600, 700) further
comprises a plurality of front fins (112) protruding from the forward facing portion
(102a) of the front member (102) and/or from the outer surface (106) of the sidewall
member (104).
3. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
claim 2, wherein each rear fin (110) of the plurality of rear fins and/or each front
fin (112) of the plurality of front fins has a first flank surface (116a) and a second
flank surface (116b),
wherein the first flank surface (116a) is perpendicular to the outer surface (106)
of the sidewall member (104), and
wherein the second flank surface (116b) is at an angle to the outer surface (106)
of the sidewall member (104) different from the first flank surface (116a).
4. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
claim 2 or 3, wherein each rear fin (110) of the plurality of rear fins and/or each
front fin (112) of the plurality of front fins extend at a transverse angle to a central
axis (AC) of the projectile (100, 100', 200, 300, 300', 400, 600, 700) about the outer
surface (106) of the sidewall member (104).
5. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
claim 4, wherein a front fin (112) of the plurality of front fins extend along a first
axis (A1), and a rear fin (110) of the plurality of rear fins extend along a second
axis (A2), wherein the first axis (A1) and the second axis (A2) are parallel.
6. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
claim 4, wherein a front fin (112) of the plurality of front fins and a rear fin (110)
of the plurality of rear fins extend along a common third axis (A3).
7. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
any one of the claims 2 to 6, wherein an outermost portion of the plurality of rear
fins (110) and/or the plurality of front fins (112) defines an outermost circumference
of the projectile (100, 100', 200, 300, 300', 400, 600, 700).
8. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
any one of the claims 2 to 7, wherein the plurality of rear fins (110) is between
2 and 32 rear fins, and/or
wherein the plurality of front fins (112) is between 2 and 32 front fins.
9. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
any one of the claims 1 to 8, wherein the plurality of rear fins (110) protrude from
the outer surface (106) of the sidewall member (104) at a ramp angle.
10. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
any one of the claims 1 to 9, wherein the rotation generating member (114) comprises
a plurality of rotor blades (120).
11. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
any one of the claims 1 to 10, wherein the forward facing portion (102a) of the front
member (102) has a hemispherical shape.
12. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
any one of the claims 1 to 11, wherein the front member (102) is solid and made of
an elastic material.
13. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
any one of the claims 1 to 12, wherein the front member (102) encloses a closed cavity
(126) comprising a fill.
14. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
claim 13, further comprising a fill nipple (128) for providing the fill to the closed
cavity (126) of the front member (102), the fill nipple (128) being arranged at a
center of the rotation generating member (114).
15. The non-lethal projectile (100, 100', 200, 300, 300', 400, 600, 700) according to
any of the claims 1 to 14, wherein the forward facing portion (102a) of the front
member (102) comprises a plurality of grooves (130).