U.S. patent application number 12/400573 was filed with the patent office on 2009-09-10 for device for launching a projectile or a launch object in general.
Invention is credited to Pasquale STANZIALE.
Application Number | 20090223500 12/400573 |
Document ID | / |
Family ID | 40786581 |
Filed Date | 2009-09-10 |
United States Patent
Application |
20090223500 |
Kind Code |
A1 |
STANZIALE; Pasquale |
September 10, 2009 |
DEVICE FOR LAUNCHING A PROJECTILE OR A LAUNCH OBJECT IN GENERAL
Abstract
Device for launching a projectile or a launch object in general,
comprising: a stock having a longitudinal development direction
between a rear or proximal end and a front or distal end; at least
two bending members associated to said stock on opposite sides of
it and having a preferential development direction, said bending
members being apt to be subjected to bending in order to accumulate
and supply energy usable to launch said projectile, and released in
a rest condition; tensioning means of said bending members; pushing
means of said projectile apt to cooperate with said bending
members. Said tensioning means comprise at least two cams arranged
on opposite sides of the stock, each of which is pivoted at a
respective first axis of rotation and is associated to at least one
corresponding bending member, so that an angular displacement of
said cam around said first axis of rotation determines a bending
action on said at least one corresponding bending member. Said
pushing means comprise at least two arms arranged on opposite sides
of the stock and connected to each other through a flexible member,
wherein each of said arms has a first end pivoted at a second axis
of rotation and a second end apt to support a portion of said
flexible member. Each of said arms is operatively connected to a
respective cam, so that a rotation of each arm in a first rotation
direction determines a bending of said bending members by means of
the cam during a loading phase of the device and that, during a
launch phase of said projectile, a return of the bending members
towards said rest condition determines, by means of the cam, a
rotation in the opposite direction of each arm.
Inventors: |
STANZIALE; Pasquale; (Ravina
TN, IT) |
Correspondence
Address: |
Steinfl & Bruno
301 N Lake Ave Ste 810
Pasadena
CA
91101
US
|
Family ID: |
40786581 |
Appl. No.: |
12/400573 |
Filed: |
March 9, 2009 |
Current U.S.
Class: |
124/25 |
Current CPC
Class: |
F41B 5/1469 20130101;
F41B 5/123 20130101 |
Class at
Publication: |
124/25 |
International
Class: |
F41B 5/12 20060101
F41B005/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 10, 2008 |
IT |
RM2008A000130 |
Oct 3, 2008 |
IB |
PCT/IB2008/054053 |
Claims
1. A device for launching a projectile or a launch object in
general, comprising: a stock having a longitudinal development
direction between a rear or proximal end and a front or distal end,
at least two bending members associated to said stock on opposite
sides of said stock and having a preferential development
direction, said bending members being adapted to be subjected to
bending in order to accumulate and supply energy usable to launch
said projectile, and being released in a rest condition, tensioning
means of said bending members, pushing means of said projectile
adapted to cooperate with said bending members, wherein: said
tensioning means comprise at least two cams arranged on opposite
sides of the stock, each of said cams being pivoted at a respective
first axis of rotation and being associated to at least one
corresponding bending member, so that an angular displacement of
said each cam around said first axis of rotation determines a
bending action on said at least one corresponding bending member,
and said pushing means comprise at least two arms arranged on
opposite sides of the stock and connected to each other through a
flexible member, wherein each of said arms has a first end pivoted
at a second axis of rotation and a second end adapted to support a
portion of said flexible member, each of said arms being
operatively connected to a respective cam of said at least two
cams, so that i) a rotation of each arm in a first rotation
direction determines a bending of said bending members through the
cam during a loading phase of the device and ii) during a launch
phase of said projectile, a return of the bending members towards
said rest condition determines, through the cam, a rotation in the
opposite direction of each arm.
2. The device according to claim 1, wherein said bending members
are arranged so that said preferential development direction is
substantially parallel to said longitudinal development direction
of said stock.
3. The device according to claim 1, wherein said bending members
are positioned substantially adjacent to said stock.
4. The device according to claim 1, wherein said at least two
bending members, said at least two cams and said at least two arms
are arranged in a manner substantially symmetrical with respect to
said stock.
5. The device according to claim 1, comprising, on each side of
said stock, at least two bending members opposite to each other
with respect to a plane on which said cams lie, forming, overall, a
group of at least four bending members symmetrical with respect to
the longitudinal development direction of the stock.
6. The device according to claim 1, wherein a portion of each of
said bending members is associated idle to a portion of a
respective cam, to allow said portion of bending member to make a
translation movement together with said portion of cam, said
translation movement taking place along a direction substantially
orthogonal to said preferential development direction of said
bending member.
7. The device according to claim 6, wherein said portion of a
respective cam is a slot in said respective cam at the respective
first axis of rotation.
8. The device according to claim 7, comprising a connection element
positioned idle in said slot, said connection element comprising a
connection member adapted to move said portion of said at least one
bending member.
9. The device according to claim 8, wherein said connection element
comprises two of said connection members, positioned symmetrically
and connected to each other by a collar which is engaged in said
slot of a respective cam, each of said connection members being
adapted to move said portion of a respective bending member.
10. The device according to claim 8, wherein said connection member
includes a housing substantially "U" or "C" shaped and adapted to
house said portion of said bending member.
11. The device according to claim 1, wherein said cams have an edge
equipped, at least partially, with a toothing.
12. The device according to claim 1, further comprising a slide
associated to the stock and positioned between the opposing cams,
said slide being adapted to slide in said stock substantially
parallel to said longitudinal development direction, said slide
being engaged on opposite sides to said cams to coordinate an
angular displacement thereof.
13. The device according to claim 12, wherein said cams have an
edge equipped, at least partially, with a toothing and said slide
has toothed edges which cooperate with the respective toothings of
said cams.
14. The device according to claim 12, wherein said slide is
removable from said stock.
15. The device according to claim 1, comprising a pivot body of
determined axis and slidingly associated to said stock to run
parallel to said longitudinal development direction, wherein a
first of said cams and a second of said cams are hinged on said
pivot body.
16. The device according to claim 1, wherein each of said arms
forms a single part with a respective cam and said second axis of
rotation of said arm is coincident with said first axis of rotation
of said respective cam.
17. The device according to claim 1, wherein each of said arms is
connected to a respective cam by at least one connection rod
pivoted to said arm and to said cam.
18. The device according to claim 1, wherein each of said arms is
operatively connected to a respective cam by means of a guide
member integral to the arm and which engages slidingly a guide
track provided in an appendix of said cam.
19. The device according to claim 1, wherein said second end of
each of said arms supports a pulley rotatably associated to the
respective arm, wherein said pulley is adapted to rotate around an
axis of rotation, said pulley being further adapted to wind, at
least partially on itself, said flexible member during a rotation
movement around said axis of rotation.
20. The device according to claim 19, wherein said pulley has an
eccentric profile with respect to said axis of rotation.
21. The device according to claim 19, wherein the rotation of said
pulley around said axis of rotation is coordinated with a
respective cam for a synchronized rotation of said respective cam
around the respective first axis of rotation.
22. The device according to claim 21, wherein said pulley includes
a pivot rotating jointly with the pulley and having a longitudinal
axis coincident with said axis of rotation of the pulley, said
pivot further comprising at least one toothed portion, and wherein
said respective cam is integral to an appendix equipped with a
guide track, said guide track comprising an edge equipped with a
toothing adapted to be engaged by said at least one toothed portion
of said pivot.
23. The device according to claim 1, wherein said arms are
rotatable between a first maximum loading position, corresponding
to a maximum bending of the bending members, and a second maximum
discharge position, between said first maximum loading position and
said second maximum discharge position there being a neutral
position at which said bending members are in said rest condition
not presenting accumulated elastic energy.
24. The device according to claim 23, wherein in said first maximum
loading position the arms are rotated towards said rear or proximal
end of the stock, and in said second maximum discharge position the
arms are rotated in the direction of said front end of the
stock.
25. The device according to claim 1, further comprising contrast
means associated to said stock, and operatively connected to said
cams.
26. The device according to claim 23, further comprising contrast
means associated to said stock, and operatively connected to said
cams, wherein said contrast means are loaded so as to exert a force
on said cams only when said arms are beyond said neutral position
towards said second maximum discharge position.
27. The device according to claim 23, further comprising elastic
means adapted to bring back said arms towards said neutral
position.
28. The device according to claim 27, further comprising a slide
associated to the stock and positioned between the opposing cams,
said slide being adapted to slide in said stock substantially
parallel to said longitudinal development direction, said slide
being engaged on opposite sides to said cams to coordinate an
angular displacement thereof, and contrast means associated to said
stock, and operatively connected to said cams, wherein said
contrast means and/or said elastic means are connected to said
slide.
29. The device according to claim 27, further comprising contrast
means associated to said stock, and operatively connected to said
cams, wherein said contrast means and/or said elastic means are
connected to said pivot body.
30. The device according to claim 1, further comprising auxiliary
pushing means including at least one elastic member adapted to
accumulate energy during said loading phase of the device and
adapted to supply said energy to said pushing means during said
launch phase of said projectile.
31. The device according to claim 25, further comprising auxiliary
pushing means including at least one elastic member adapted to
accumulate energy during said loading phase of the device and
adapted to supply said energy to said pushing means during said
launch phase of said projectile, wherein said auxiliary pushing
means are side by side to said contrast means.
32. The device according to claim 23, wherein, in said neutral
position, said flexible member substantially intercepts said second
axes of rotation of said arms.
33. The device according to claim 1, comprising associating means
of at least one of said bending members to said stock, wherein said
associating means are adapted to prevent a translation of a first
tract of said at least one bending member in a direction orthogonal
to said stock, and to allow said first tract a bending movement,
and/or an angular displacement with respect to said stock, and/or a
translation in said preferential development direction of said at
least one bending member.
34. The device according to claim 33, wherein said associating
means are adapted to prevent said translation in said orthogonal
direction to a first tract and to a second tract of said at least
one bending member.
35. The device according to claim 33, wherein said associating
means comprise a wire or other flexible retaining member.
36. The device according to claim 1, comprising a fixed support
adapted to prevent a translation of a first tract of at least one
of said bending members in a direction orthogonal to said stock,
wherein said fixed support also prevents an angular displacement of
said first tract with respect to said stock.
37. The device according to claim 36, wherein a second tract of
said at least one bending member is associated idle to one of said
cams.
38. The device according to claim 1, comprising associating means
of at least one of said bending members to said stock, wherein said
associating means are adapted to join a tract of said at least one
bending member to the stock in such a way as to prevent said tract
both a translation with respect to the stock in said preferential
development direction and in a direction orthogonal to said
preferential development direction, and an angular displacement
with respect to the stock.
39. The device according to claim 1, wherein said device is a
crossbow.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of Italian Patent
Application RM2008A000130 filed on Mar. 10, 2008 and PCT patent
application PCT/IB2008/054053, both of which are incorporated
herein by reference in their entirety.
FIELD
[0002] The present disclosure refers to a device for launching a
projectile, or an arrow, or a bolt, or a launch object in general.
More specifically, it refers to a perfected type of archery
crossbow.
BACKGROUND
[0003] Various types of devices for launching projectiles are
already known, both for sports and amateur uses, and for
professional uses. Among these, we can identify, in particular,
crossbows, generally consisting of a bow (in wood, metal, or
plastic or composite material, e.g. including glass or carbon
fiber) apt to accumulate elastic energy to return it to the
projectile to be launched, a propulsive wire for pushing the
projectile, a fastening system to keep said wire in the load
position and then release it, a stock secured at one end to said
bow and comprising a support-guide for the projectile.
[0004] The modern devices for launching a projectile usually have a
bow divided into two bending members (or flexing members, also
called limbs) which are identical (left and right) and secured to a
central handle member or to an end of a stock of the device.
[0005] In some devices (e.g. U.S. Pat. No. 3,854,467; U.S. Pat. No.
3,923,035; U.S. Pat. No. 3,987,777), there are pulleys pivoted to
the free ends of the bending members and pulleys pivoted to a
central member; the pulleys include tracks on which a propulsive
wire is partially wound; under the most common arrangement a
propulsive wire is connected to one pulley and to its symmetrically
opposite one on the other side; each one of said pulleys is
integral to a smaller pulley, which holds one end of another wire
whose other end is connected to the opposite limb. Some of the
pulleys may have an eccentric profile.
[0006] The traction of the propulsive wire turns the pulleys,
unwinding the propulsive wire from some pulleys, while at the same
time the other wires are wound around other pulleys; this causes
the flexing of the bending members and the accumulation of elastic
energy. Thanks to an adequate profiling of the pulley tracks and an
appropriate eccentricity of the same, in these devices it is
possible to reduce the maximum force which must be exerted by the
user during the loading of the device and to increase the ratio
between the stroke of the projectile (also called "draw length")
and the movement of the ends of the bending members.
[0007] Other devices for the launching of projectiles comprising
pulleys or the like for a similar purpose are disclosed, for
example, in U.S. Pat. No. 5,388,564, U.S. Pat. No. 5,499,618, U.S.
Pat. No. 5,967,132.
[0008] Crossbows comprising pulleys are disclosed, for example, in
U.S. Pat. No. 5,630,405 and U.S. Pat. No. 6,155,243.
[0009] One of the main disadvantages of the devices of known art
and, in particular, of crossbows of known art, is that during the
launch phase, the bending members, the propulsive wire and any
pulleys arrive at the end of the stroke with a high residual
kinetic energy, proportional to the masses in movement; because of
the very structure of the device, this energy must be dissipated in
a very short space or even in no space, as the components in motion
have already reached the end of their possible stroke. The stopping
of the components in motion after the launch is, therefore, quite
sudden and subjects the entire device to an end of stroke shock
which involves very high stresses, discharging the residual energy
on the wires and stressing the pivots of the pulleys and the
bending members. Indeed, in the case of dry firing (that is, no
projectile is fired), there is no transfer of energy to a free mass
and the stresses may be so high as to break the device.
[0010] This dictates structural constraints in the dimensioning of
the device, imposes practical limits on the mass that can be
launched safely and imposes very high levels of attention and
expertise on the part of the user who, in case of dry firing or of
using too light a projectile, could damage the crossbow or even get
injured.
[0011] In the case of said more advanced devices, the problem is
actually accentuated by the presence of the pulleys at the ends of
the bending members, as this considerably increases the masses, the
kinetic energy and the moments of inertia in play. In addition, the
sudden stop at the end of the stroke is the main cause of the noise
produced by the use of these devices for launching a
projectile.
[0012] Another disadvantage of the devices of known art is the fact
that, even when the device is unloaded, the bending members are in
a pre-tensioned state; among other things, this makes it necessary
to use specific tools, such as a press, in order to carry out
maintenance operations such as the replacement of the propulsive
wire.
[0013] Finally, it must be noted that possible differences, even
slight ones, in the elastic characteristics of the right and left
bending member may be the cause of asymmetries in the thrust
exercised on the projectile and, therefore, compromise the launch
precision.
[0014] On the other hand, not even the pulleys manage to compensate
for any such differences in the elastic characteristics of the
bending members.
[0015] Also note that the crossbows of known art usually take the
form of a device which allows little or no possibility of adapting
it to the requirements of the user: once a crossbow of known art
has been built to certain specifications, the maximum power or the
force required for the loading are substantially fixed and can no
longer be varied, except with laborious replacements of components
which, in any case, are beyond the common user's skill. These
interventions, in fact, are dangerous and also void the warranty
provided by the manufacturer.
[0016] An archery crossbow 1001 according to the known art (U.S.
Pat. No. 6,155,243) is shown in FIG. 1. It has a stock 1002 with a
butt 1003, bending members 1010 connected to said stock 1002, a
propulsive wire 1031 for pushing a projectile, a fasten and release
system (not shown, but located near the butt 1003) for said
propulsive wire 1031, a shooting trigger (not shown). The free ends
of the bending members 1010 support eccentric pulleys 1009, so that
the propulsive wire 1031 passes at these and connects them to the
bending member opposite. During the loading phase, shown in FIG. 1,
the propulsive wire 1031 is drawn towards the butt 1003, causing
the eccentric rotation of the pulleys 1009, the bending of the
bending members 1010 and the accumulation of elastic energy in
these. During the launch phase, the same movements take place in
the opposite direction, with the transfer of energy to a projectile
(not shown) which slides in a suitable guide track 1008. This type
of known-art crossbow 1001 has the disadvantages mentioned
above.
SUMMARY
[0017] The present disclosure, therefore, starts from the position
of the technical problem of providing a device for launching a
projectile or a launch object in general which makes it possible to
overcome the disadvantages specified above with reference to the
known art.
[0018] As defined in independent claim 1, this is obtained by
providing a device for launching a projectile or a launch object in
general, comprising: a stock having a longitudinal development
direction between a rear or proximal end and a front or distal end,
at least two bending members associated to said stock on opposite
sides of it and having a preferential development direction, said
bending members being apt to be subjected to bending in order to
accumulate and supply energy usable to launch said projectile, and
released in a rest condition, tensioning means of said bending
members, pushing means of said projectile apt to cooperate with
said bending members, wherein said tensioning means comprise at
least two cams arranged on opposite sides to the stock, each of
which is pivoted at a respective first axis of rotation and is
associated to at least one corresponding bending member, so that an
angular displacement of said cam around said first axis of rotation
determines a bending action on said at least one corresponding
bending member, and said pushing means comprise at least two arms
arranged on opposite sides of the stock and connected to each other
through a flexible member, wherein each of said arms has a first
end pivoted at a second axis of rotation and a second end apt to
support a portion of said flexible member, each of said arms being
operatively connected to a respective cam, so that a rotation of
each arm in a first rotation direction determines a bending of said
bending members by means of the cam during a loading phase of the
device and that during a launch phase of said projectile a return
of the bending members towards said rest condition determines, by
means of the cam, a rotation in the opposite direction of each
arm.
[0019] Secondary characteristics of the subject of the present
disclosure are defined in the corresponding dependent claims.
[0020] The subject of the present disclosure provides certain
significant advantages. A main advantage lies in that the device
permits a reduction in the stresses acting on the structure in the
end-of-stroke arrest, thanks to the gradual absorption of the
inertia and kinetic energy of the parts in movement in a braking
run which follows the propulsive run. Furthermore this braking run
is especially long as can be seen from the drawings. Also the
braking run does not cut short the useful run of the limbs or
bending members, for example by elastically intercepting the
propulsive wire some distance before their neutral position as
conceivable in devices of known art, that is, while they are still
partially under tension; on the contrary, the braking run
intervenes when the bending members have exhausted all the stored
energy and when they have crossed the neutral, zero energy state
while flexing in the opposite direction. The device can thus handle
higher energies while also featuring smoother and more silent
action and higher safety levels for the user particularly in case
of dry firing, compared to known-art devices.
[0021] A second advantage lies in that the device makes it possible
to load higher energies compared to known-art devices. In fact the
use of a solid body (i.e., said cams) as the primary mover acting
on the bending members (rather than a wire) allows for the
application of greater force and the use of more rigid bending
members, thereby increasing the maximum energy that can be
transmitted.
[0022] Another advantage lies in that the device makes it possible
to vary the specific use characteristics and it has a simpler
maintenance. In fact said bending members are released in the rest
condition, i.e. they do not present accumulated elastic energy and
are non-deformed, so they can easily and safely be replaced with
other bending members of same or different characteristics. Also
the bending members do not present the risk of seeing their
performance degraded in warmer storing conditions.
[0023] A further advantage lies in that said device makes it
possible to synchronize the rotation of the left and right pushing
means or pushing arms, in order to compensate for asymmetries in
the elastic properties of left and right bending members. This
determines a uniform distribution of the force acting on the
projectile during the launch phase, eliminating the components of
the acting force which are orthogonal to the launch direction,
which benefits the launch accuracy.
[0024] In one embodiment, the bending members are arranged so that
their preferential development direction is substantially parallel
to the longitudinal development direction of the stock. This
benefits the compactness of the device, reducing the lateral
dimensions. Preferably, the bending members are positioned close to
the stock.
[0025] In one embodiment, the bending members, the cams and the
arms are arranged in a manner substantially symmetrical with
respect to the stock. This configuration is advantageous as the
symmetrical arrangement favors a symmetrical and balanced
distribution of the forces acting on the stock.
[0026] In one embodiment, the axes of rotation of the cams move
together with a portion of at least one bending member, in a
direction orthogonal to the development direction of the bending
member. This movement takes place at the same time as the rotation
of the cam, thanks to the fact that the cam has an eccentric
profile which cooperates with a respective cam positioned
symmetrically. This makes it possible to load the device by means
of a rotation of the cams around their axes of rotation and launch
the projectile with a rotation movement in the opposite
direction.
[0027] More specifically, the cams are pivoted using a connection
element which comprises at least one "U"-shaped or "C"-shaped
housing which houses a portion of the respective bending
member.
[0028] In one embodiment, the movement of each cam is synchronized
with a respective cam positioned symmetrically with respect to the
stock. This allows for a uniform distribution of the force acting
on the projectile during the launch phase, even in the presence of
asymmetries in the elastic characteristics of the bending members,
and also makes it possible to eliminate the components of the
acting force which are orthogonal to the launch direction; this
benefits the launch precision.
[0029] In one embodiment, the cams have an edge with teeth, so that
each cam can engage the respective symmetrical cam by means of
these teeth. This makes it possible to synchronize the movement of
each cam with the respective symmetrical cam.
[0030] In one embodiment, there is a slide positioned between one
cam and the respective symmetrical cam; said slide may slide in the
device stock in a direction parallel to the longitudinal
development direction of the stock and is engaged by the edges of
the cams. In this way, the motion of the cams is synchronized
thanks to the fact that they both engage the slide and make it
slide along the stock.
[0031] To be more specific, the slide may have toothed edges in
order to engage the toothing of the cams.
[0032] Alternatively, the synchronization between the cams is
obtained by hinging together one cam and the respective symmetrical
cam, which are pivoted to each other using a pivot body which is
slidingly associated to the stock and may slide within it parallel
to its longitudinal development direction.
[0033] In one embodiment, each pushing arm forms a single part with
a respective cam and the axis of rotation of the arm is the same as
the axis of rotation of the respective cam. This solution has the
particular advantage of requiring a lower number of parts and being
of simpler construction.
[0034] In one embodiment, each pushing arm is operatively connected
to a respective cam using at least one connection rod pivoted to
the arm and to the cam. This solution makes it possible to reduce
the maximum lateral dimensions of the device and allows for greater
design flexibility.
[0035] In one embodiment, each pushing arm is operatively connected
to a respective cam using a guide member (for example, a rotating
wheel) joined to the arm and which engages slidingly a guide track
provided in an appendix of said cam. This solution allows, for same
lateral dimensions, higher device power and a longer stroke for the
flexible member.
[0036] In one embodiment, the second end of each pushing arm
supports a pulley rotationally associated to the respective arm;
said pulley rotates around an axis of rotation which, therefore,
performs translation movements together with the second end of the
respective arm; the pulley is further apt to wind on to itself at
least partially the flexible member during a rotation movement
around its axis. Preferably, the pulley has an eccentric profile
with respect to said axis of rotation.
[0037] Even more preferably, the rotation of the pulley is
synchronized with the rotation of a respective cam around the
respective axis of rotation. More specifically, the pulley includes
a pivot integral to it and having a longitudinal axis which is
coincident to said axis of rotation of the pulley; said pivot also
includes at least one toothed portion; the respective cam is firmly
joined to at least one appendix having a guide track, said guide
track comprising an edge with toothing apt to be engaged by said
toothed portion of said pivot.
[0038] These solutions presenting a pulley supported at the end of
each arm offer a first advantage consisting of not leaving the
flexible member slack at the end of the launch. In addition, the
possibility of selecting the eccentricity of the pulley, the
magnitude of the angle of rotation of the pulley, and an opportune
dimensioning and relative positioning of the parts makes it
possible to obtain various different force-draw curves. A further
advantage is the cancelling out of the residual forces acting on
the device and of the inertia of the pulleys, thanks to the
movement of these in opposite directions.
[0039] In one embodiment, the pushing arms may rotate between a
first position of maximum loading and a second position of maximum
discharge. Between said first and second positions, there is a
neutral position at which the bending members do not present
accumulated elastic energy. In particular, in said first position
of maximum loading the pushing arms are rotated towards the
proximal end of the stock, and in said second position of maximum
discharge they are rotated towards the distal end of the stock.
[0040] To be more specific, said second position corresponds to the
maximum advance of the arms towards the distal end, in the braking
stroke after the launch stroke, where with launch stroke it is
meant the run of the arms between said first position of maximum
loading and said neutral position, while with braking stroke it is
meant the run of the arms between said neutral position and said
second maximum discharge position.
[0041] Therefore, with the device loaded, the bending members are
initially in a bent configuration; during the launch phase, the
bending members reduce the bending gradually, they pass the rest
position (corresponding to said neutral position) and continue
their movement by bending in the opposite direction, until they get
to a configuration of maximum counter bend corresponding to said
second position of maximum discharge. One advantage of this
solution is that it allows for a gradual and non-sudden stopping of
the components at the end of the launch phase, thereby reducing the
stresses at the end of the stroke and the risk of damaging the
device.
[0042] Contrast means operating when the arms are between the
neutral position and the position of maximum discharge may also be
provided.
[0043] In addition or in alternative to the contrast means, the
device may include auxiliary pushing means including at least one
elastic member apt to accumulate energy during the device loading
phase and apt to supply energy to the pushing means during the
projectile launch phase. This makes it possible to increase the
power of the device for same overall dimensions.
[0044] Further advantages, characteristics and the modes of
employment of the subject of the present disclosure will become
apparent from the following detailed descriptions of preferred
embodiments thereof, presented for exemplificative and not
limitative purposes.
[0045] It is however evident that each embodiment described in this
disclosure may present one or more of the advantages listed above;
in any case, it is not required that each embodiment presents at
the same time all the advantages listed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Reference will be made to the figures of the drawings
attached, in which:
[0047] FIG. 1 shows a plan view of an embodiment of a crossbow
according to the known art;
[0048] FIG. 2A shows a perspective view of a first embodiment of a
device for launching a projectile according to the present
disclosure;
[0049] FIG. 2B shows a perspective view of the device in FIG. 2A,
in which different operative positions are shown;
[0050] FIG. 3 shows an enlarged detail of the device in FIG. 2A in
a loading phase;
[0051] FIG. 3A shows a further enlarged detail of the device in
FIG. 2A;
[0052] FIG. 4 shows again a detail of the device in FIG. 2A in a
launch phase;
[0053] FIG. 5 shows a construction detail of the device in FIG.
2A;
[0054] FIG. 6 shows a perspective view of a component of the device
in FIG. 2A;
[0055] FIG. 7 shows an exploded perspective view of another
component of the device in FIG. 2A;
[0056] FIG. 8 shows a perspective view of a second embodiment of a
device for launching a projectile according to the present
disclosure;
[0057] FIG. 8A shows a construction detail of the device in FIG. 8,
from which some components have been removed;
[0058] FIG. 9A shows a perspective view of a third embodiment of a
device for launching a projectile according to the present
disclosure;
[0059] FIG. 9B shows a perspective view of the device in FIG. 9A,
in which a different operative position is shown;
[0060] FIG. 10 shows a perspective view of the device in FIG. 9A,
from which some components have been removed;
[0061] FIG. 11A shows a perspective view of a fourth embodiment of
a device for launching a projectile according to the present
disclosure;
[0062] FIG. 11B shows a perspective view of the device in FIG. 11A,
in a different operative position;
[0063] FIG. 11C shows a plan view from below of the device in FIG.
11A, from which some components have been removed, in a further
operative position;
[0064] FIG. 11D shows a perspective view of an enlarged detail of
the device in FIG. 11A, from which some components have been
removed;
[0065] FIG. 12A shows a perspective view of a fifth embodiment of a
device for launching a projectile according to the present
disclosure, in a first operative position;
[0066] FIG. 12B shows a perspective view of the device in FIG. 12A,
in a second operative position;
[0067] FIG. 12C shows a plan view of the device in FIG. 12A, in a
third operative position;
[0068] FIG. 13 shows a perspective view, partially in
cross-section, of an enlarged detail of the device in FIG. 12A,
from which some components have been removed;
[0069] FIG. 14A shows a perspective view of a sixth embodiment of a
device for launching a projectile according to the present
disclosure, in a first operative position;
[0070] FIG. 14B shows a perspective view of the device in FIG. 14A,
in a second operative position;
[0071] FIG. 14C shows a perspective view of the device in FIG. 14A,
in a third operative position;
[0072] FIG. 15 shows a perspective view, partially in
cross-section, of an enlarged detail of the device in FIG. 14A,
from which some components have been removed;
[0073] FIG. 16 shows a side perspective view of an enlarged detail
of the device in FIG. 14A;
[0074] FIG. 17A shows a perspective view of a seventh embodiment of
a device for launching a projectile according to the present
disclosure, in a first operative position;
[0075] FIG. 17B shows a perspective view of the device in FIG. 17A,
in a second operative position; and
[0076] FIG. 17C shows a perspective view of the device in FIG. 17A,
in a third operative position.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0077] A first embodiment of a device for launching a projectile,
an arrow, a bolt, or a launch object in general, created according
to the present disclosure, is shown in FIGS. 2A to 7, where it is
indicated with the reference number 1. Hereinafter in the
description, particular reference will be made to an archery
crossbow, although the same principles of the subject of the
present disclosure could similarly be applied to other launch
devices, such as for example a bow or a catapult.
[0078] The crossbow 1 comprises a stock 2 with a longitudinal
development direction 201, comprised between a rear or proximal end
205 and a front or distal end 206. The other components are
connected to the stock 2. The portion of the stock 2 which is
closest to a user during use, that is, the rear or proximal end
205, comprises, in fact, a butt 3, a handle 4, a system 5 for
positioning and holding a projectile or a bolt or an arrow (not
shown in the figures), a system 6 for fastening a flexible member
31 for pushing a projectile, a trigger 7 which makes it possible to
open the fastening system 6 in order to release the flexible member
31 when launching the projectile. The components listed so far can
be considered to be substantially known-art components and,
therefore, will not be described in greater detail.
[0079] The crossbow 1 also comprises at least two bending members
10, which have an elongated shape along a preferential development
direction 202, for example, with a parallelepiped shape. They may
be made of wood, metal, fiberglass, plastic or composite material,
e.g. including glass or carbon fiber, or other suitable material.
The bending members 10, from the structural and functional point of
view, may be considered to be substantially identical to the
bending members used in known-art crossbows.
[0080] The bending members 10 are suitable for being subjected to
bending in order to accumulate the elastic energy required to
launch the projectile and to supply it subsequently during the
launch itself. At the end of the launch of the projectile, the
bending members 10 are released in a rest condition.
[0081] In the embodiment represented here, the bending members 10
are positioned substantially adjacent to the stock 2 and in a
symmetrical manner with respect to it, so that their preferential
development direction 202 is substantially parallel to said
longitudinal development direction 201 of the stock 2 itself; to be
more specific, there are four bending members 10, as there are two
on each side of the stock 2.
[0082] The bending members 10 are associated to the stock 2 on
opposite sides of it. To be more specific, the bending members 10
are connected and/or may be connected (in other words, associated)
to the stock 2 using supports 11 positioned at the ends 101, 102 of
the bending members 10. Said supports 11 are pivoted to the stock 2
and have a housing 12 substantially with a "C"-shape which houses
said end, in any case allowing the bending member 10 a limited
translation movement along said preferential development direction
202; the bending member 10 can, in fact, slide in said housing 12
along that direction. This is beneficial during the loading phase
of the bending members 10, as it allows them to take on a simply
arched shape, preventing the creation of longitudinal stresses. In
addition, the bending members 10 may be removable, said supports 11
being made so as to allow the extraction of the bending members 10
when it is necessary to replace them.
[0083] The bending members 10 might, however, have said support 11
only at one end, while the other end might be constrained in a
rigid manner to the stock 2. They might also be secured with
different methods, e.g. using a ring wire which surrounds and
tightens a bending member 10 and its corresponding bending member
on the other side of the stock 2; this solution will be illustrated
below.
[0084] Alternatively, each end 101, 102 of a bending member 10 is
closed off at the side between a first sidebar, e.g. with a
cylindrical shape, constrained to the stock 2 and a second sidebar,
e.g. a support which is preferably cylindrical, positioned outside
the bending member 10 with respect to the stock 2, as illustrated
in FIGS. 11A to 11D for another embodiment.
[0085] As an alternative, at least one portion of a bending member
10 can be constrained in a rigid manner to the stock 2. In other
words, a portion or tract of a bending member 10 can be tightly
joined to the stock 2, so as to substantially prevent any movement
(translation, rotation and/or flexion movement) of the tract itself
with respect to the stock 2.
[0086] It is also possible to combine these methods to associate a
bending member 10 to the stock 2; for example, a bending member 10
could include a first end constrained using said support 11 and a
second end constrained using said cylindrical sidebars. Similarly,
different bending members 10 may have different association
methods.
[0087] The crossbow 1 comprises tensioning means 20 for said
bending members 10, that is, means apt to bring them to a bent
position during said loading phase. The tensioning means 20
comprise at least two cams 21 positioned in opposite sides of the
stock 2, symmetrical with respect to said stock 2. Each cam 21 is
pivoted at a respective first axis of rotation 22 and is associated
to at least one corresponding bending member 10, so that an angular
displacement of the cam 21 around said first axis 22 creates a
bending action on the corresponding one or more bending members
10.
[0088] In the embodiment illustrated, the overall structure is such
that each side of the stock 2 has at least two bending members 10
opposite to each other with respect to a plane on which the cams 21
lie and on which their rotation movement takes place, in order to
create, overall, a group of at least four bending members 10
symmetrical with respect to the longitudinal development direction
201 of the stock 2.
[0089] The cams 21 have an edge 23 having an eccentric profile with
respect to said first axis of rotation 22, said edge 23 also
having, at least partially, a toothing 24.
[0090] In addition, there is a slide 25 associated to the stock 2
and positioned between the cams 21.
[0091] Said slide 25 has a substantially elongated shape and has
toothed edges 26, by means of which it is in engagement on opposite
sides with the teeth 24 of the cams 21. The slide 25 slides in the
stock 2 substantially parallel to said longitudinal development
direction 201 and, during said sliding movement, coordinates the
angular displacement of the cams 21. In addition, the slide 25 can
be removed from the stock 2.
[0092] The crossbow 1 also comprises connection elements 27 between
cams 21 and bending members 10. Each connection element 27
comprises at least one connection member apt to move a portion of a
bending member 10. To be more specific, said connection member
includes a housing 28 substantially "U"-shaped or "C"-shaped apt to
house said portion of bending member 10; the connection element 27
also comprises a cylindrical collar 29.
[0093] In this embodiment, each bending member 10 is fixed with
respect to the corresponding connection element 27, that is, a
translation movement of the connection element 27 with respect to
the bending member 10 along its preferential development direction
202 is prevented; the connection element 27 and the bending member
10, therefore, move together.
[0094] The connection element 27 represented in FIG. 3A comprises
two of said connection members, each with a "U"-shaped housing 28,
positioned symmetrically with respect to a plane and connected to
each other by said cylindrical collar 29; this connection element
27 is, therefore, apt to be associated with two bending members 10
and each of said connection members is apt to move a portion of a
respective bending member 10.
[0095] There are suitable guides for limiting the movements of the
connection element 27 with respect to the stock 2. To be more
specific, one of said "U"-shaped housings 28 has a first groove 191
on a face facing the proximal end 205 and a second groove 191,
parallel to the first groove, on a face facing the distal end 206.
Each of these grooves 191, which extend on a plane orthogonal to an
axis of the cylindrical collar 29, is engaged by a rail 190 which
extends laterally from the stock 2 and orthogonally to the
longitudinal axis 201. As a result, the connection element 27 is
constrained to move, with alternate motion, parallel to the plane
defined by these rails 190 and orthogonal to the longitudinal axis
201.
[0096] The connection element 27 and, in particular, the collar 29,
is positioned idle in a slot 211 in a respective cam 21 at the
respective first axis of rotation 22. To be more specific, the slot
211 is a hole.
[0097] This way, the cam 21 is pivoted at the connection element 27
and its axis of rotation 22 is substantially the same as the axis
of said cylindrical collar 29. Thanks to the connection element 27
and the pivoting methods, a portion of each bending member 10 is
associated idle to the respective slot 211 so as to allow said
portion of bending member 10 to make a translation movement
together with the slot 211; in particular, said translation
movement takes place in a direction substantially orthogonal to the
preferential development direction 202 of the bending member
10.
[0098] Therefore, the first axis of rotation 22 may make
translation movements together with a portion of the respective
bending members 10. Note that this portion of the bending members
10 corresponds to the region positioned about half way along their
length. However, in another possible embodiment, this portion might
correspond, for example, to an end region of the bending members
10; in this case only the other end of the bending members 10 would
be constrained to the stock 2.
[0099] The crossbow 1 also comprises pushing means 30 for said
projectile apt to cooperate with the bending members 10. They
include a flexible member 31, such as, for example, a propulsive
wire for pushing a projectile, and at least two lever arms 32
positioned on opposite sides of the stock 2 and connected to each
other by the flexible member 31.
[0100] Each of the arms 32, i.e. the pushing arms, has a first end
which is pivoted to the stock 2 at a second axis of rotation 33 and
a second end 34 apt to support, and in particular to hold, a
portion of said flexible member 31. The flexible member 31 may be
secured to the stock 2 or to the arms 32 using a suitable securing
device 35. In the case where the flexible member 31 is secured to
the stock 2, it will be held by said second end 34 so that it may
slide somewhat with respect to the end 34 itself. If, on the other
hand, the flexible member 31 is secured to the arms 32, it may
further be secured also to said end 34.
[0101] During a rotation movement with respect to said second axis
of rotation 33, the arms 32 are apt to cooperate with the
tensioning means 20 to realize a transfer of energy to said bending
members 10 during the loading phase of the crossbow 1 and a
transfer of energy from said bending members 10 to said pushing
means 30 during the projectile launch phase.
[0102] In a first embodiment, each arm 32 forms a single part with
a respective cam 21; in this case, said first axis of rotation 22
of the cam 21 is the same as said second axis of rotation 33 of the
arm 32.
[0103] As illustrated in FIG. 2B, the arms 32 can be rotated
between a first maximum loading position, corresponding to a
maximum bending of the bending members 10, and a second maximum
discharge position following the launch of the projectile. Between
said first and second positions, there is a neutral position, at
which the bending members 10 do not have accumulated elastic
energy, as they are in a rest condition in a non-deformed state, as
illustrated in FIG. 2A.
[0104] To be more specific, in the present embodiment said first
rotation direction during the loading phase is directed towards
said proximal end 205 of the stock 2, and said rotation in the
opposite direction during the launch phase is directed towards said
distal end 206 of the stock 2.
[0105] For the sake of clarity, note that FIG. 2B intends to show
these possible positions through a single drawing; it is intended,
obviously, that, in a crossbow 1 according to the present
disclosure, the right and left arms 32 will move in a substantially
synchronized manner and the two arms 32 will be in the same
position at the same time.
[0106] To be more specific, in the neutral position, the flexible
member 31 passes at said second axes of rotation 33 of the arms 32
intercepting them.
[0107] Contrast means 50 may also in case be provided, associated
to the stock 2 and operatively connected to the cams 21, in order
to dampen the motion of the arms 32 and the cams 21; said contrast
means 50, for example, include a cylinder 51 with a small hole 52,
a piston 53, a spring 54 and a rod 55. The contrast means 50 are
connected to the slide 25 by the rod 55 (slotted in, for example)
which, therefore, follows its movement parallel to the longitudinal
development direction 201 of the stock 2. Depending on the extent
of the counter bending permitted for the bending members 10 (also
related to their rigidity) and the choices for the dimensioning of
the components of the crossbow 1, the contrast means 50 may also
dampen the motion of the bending members 10 by means of the
interaction with the arms 32 and with the cams 21.
[0108] The contrast means 50 are loaded so as to apply a force
against the cams 21 when the arms 32 are past said neutral position
towards said second maximum discharge position. In fact, when the
arms 32 have passed the neutral position, the rod 55 is inserted in
the piston 53 and pushes against a special recess (not shown) with
a cone-shaped terminal; this way, the piston 53 is pushed inside
the cylinder 51 and, thanks to a ring-shaped collar 56 on the outer
surface of the piston 53, compresses the spring 54 and pushes the
air towards the outside of the cylinder 51 through the small hole
52. This way, a slowing down of the motion of the arms 32 is
obtained thanks to the transfer of energy to the spring 54 and
thanks to the compression action on the air in the cylinder 51; the
fluid dynamic resistance related to the flow of air through the
small hole 52 contributes to the dissipation of the kinetic energy
possessed by the moving parts.
[0109] When the arms 32 are between said first maximum loading
position and said neutral position, the rod 55 is not in contact
with said recess with cone-shaped terminal, of the piston 53 and,
therefore, the contrast means 50 do not have any influence on the
motion of the arms 32 themselves.
[0110] These same elastic means represented by the spring 54 can
bring the arms 32 back towards the neutral position, so that, at
the end of the launch phase, they are in this position again.
[0111] The crossbow 1 may comprise a cover 61, positioned at the
slide 25 and pivoted to the stock 2 at one end 62, which makes it
possible to protect the internal members and to access them only
when necessary; to be more specific, this makes it possible to
proceed to the replacement of the slide 25. For safety reasons, it
is possible to open the cover 61 only when the crossbow 1 is not
loaded and the flexible member 31 has been removed. In addition,
the cover 61 includes at least one tooth 65 (preferably, a pair of
teeth 65) coming out of the cover 61 near its distal end, said at
least one tooth 65 having the function of stopping the run of the
flexible member 31 at the end of the launch phase in order to
prevent the flexible member 31 from falling beyond the cover
61.
[0112] Covering members 63 with a "U"-shape (upside down with
respect to the corresponding housing 28) may be secured in a
reversible manner to said connection elements 27 and cooperate with
these in order to keep the bending members 10 in position.
[0113] In addition, there is a perimeter protective structure 64
which substantially limits the region in which the arms 32 move, in
order to assist the user with preventing interference with any
objects present nearby and to avoid getting struck by the arms 32
themselves.
[0114] During a loading phase of crossbow 1, the user pulls the
flexible member 31 towards the proximal end 205 of the stock 2,
until the flexible member 31 is engaged in the fastening system 6.
During this operation, the arms 32 and the cams 21 rotate in an
initial direction around the respective axes of rotation 33, 22;
thanks to the edges 23 with eccentric profile on the cams 21 which
push against the slide 25, the slot 211 on each cam 21 (and,
therefore, the axis of rotation 22) moves orthogonally to the
development direction 201 of the stock 2, thereby causing a bending
of the respective bending members 10 through the cam 21. The
bending members 10, therefore, are in the bent configuration
illustrated in FIG. 2B and in FIG. 3. At the same time, the slide
25 slides towards the distal end 206 of the stock 2. When the
maximum loading position is reached and a projectile is placed in a
suitable track 8 on the stock 2, the crossbow 1 is ready for
launching.
[0115] Pressing of the trigger 7 starts a projectile launch phase,
during which the flexible member 31 is released from the fastening
system 6. The bending members 10 tend to return to the rest
position, that is, the non-deformed neutral position, and therefore
push on the cams 21 making them rotate in the opposite direction
with respect to the loading phase. Through the cams 21, the arms 32
in turn rotate towards the distal end 206 of the stock 2 and pull
the flexible member 31, which transfer energy to the projectile. At
the same time, the slide 25 moves towards the proximal end 205.
[0116] When the neutral position is reached, the inertia of the
arms 32, the cams 21 and the bending members 10 has them continuing
their run past the neutral position tending towards the maximum
discharge position; in this portion of the stroke, the bending
members 10 are in a bent position towards the longitudinal axis 201
of the stock 2 (that is, in a counter bent configuration with
respect to the loaded position) and the flexible member 31 is no
longer tensioned. In case of an especially high residual kinetic
energy (for example, in case of a very light projectile or of dry
firing), the arms 32 may reach said maximum discharge position, in
which they are rotated towards the distal end 206, for example, by
25.degree. with respect to the neutral position.
[0117] In this portion of the stroke, the movement of the cams 21
and the arms 32 is opposed by the contrast means 50, which also
dissipate part of the kinetic energy; according to the methods
described, these contrast means 50 only operate starting from the
neutral position.
[0118] Thanks to the combined action of the bending members 10 and
the spring 54, which tend, obviously, towards the respective
non-deformed positions, the entire system is then brought back to
the neutral position, where it stops.
[0119] Note that the toothings 24 and 26 and the slide 25 are made
so that they are mutually engaged even in the stroke between the
neutral position and the maximum discharge position; to be more
specific, there may be a particular portion of toothing, for
example, with deeper teeth and/or possibly with a non-straight
profile, to make sure that there is no accidental disengagement.
This is especially advantageous for preventing the cams 21 from
disengaging the slide 25 when, with the crossbow 1 unloaded and the
bending members 10 in the rest condition, the arms 32 are pushed by
the user towards the maximum discharge position. Note, in fact,
that, with the crossbow 1 unloaded, this movement towards the
maximum discharge position may be executed without this involving
the deformation of the bending members 10.
[0120] From the above description it is understood how the end of
stroke shock is, therefore, substantially eliminated, since the
stopping of the components at the end of the useful run is not
sudden as with the known art, but takes place within the stroke
between the neutral position and the discharge position, and
return. This enables a major reduction in the structural stresses,
the noise and the risks related to the use of too light a
projectile or no projectile at all. To the same end also the better
distribution of the masses of the components, as they are much
closer to the center of mass and to the longitudinal axis 201 of
the stock 2. A crossbow according to the present disclosure will be
lighter than a known-art crossbow and the center of mass will be
closer to the handle 4 for same power.
[0121] Note that, because of the eccentric profile 23 of the cams
21, when the bending members 10 are in a non-deformed position, the
arms 32 can rotate towards the maximum discharge position without
this determining the deformation of the bending members 10
themselves. In this case, the spring 54 has the additional function
of bringing back and maintaining the arms 32 in the neutral
position when the crossbow 1 is unloaded, pushing them towards that
position.
[0122] The slide 25 allows for the synchronization of the motion of
the cams 21 and, therefore, of the arms 32: this way, even in case
of asymmetries in the elastic characteristics of the bending
members, the force acting on the projectile through the flexible
member 31 is in any case balanced and does not have any component
orthogonal to said track 8. The synchronization of the motion of
the cams 21 one with the other and of the arms 32 one with the
other guarantees a balanced pull on the flexible member 31 and this
absolves a condition necessary for the purpose of precision.
[0123] This configuration makes it possible to considerably
increase (with respect to the known art) the ratio between the
stroke of the projectile and the extent of the shifting of the
masses of the bending members 10, thereby increasing the efficiency
of the conversion between potential and kinetic energy; an adequate
profiling of the edges 23 of the cams 21 and, in case, of the edges
26 of the slide 25 also makes it possible to obtain a more marked
reduction in the maximum loading force with respect to the known
art.
[0124] The fact that the slide 25 is removable also makes it
possible to easily vary the characteristics of the crossbow 1,
adapting them to the use requirements. It can, in fact, be replaced
by another slide 25 having profiles 26 which are not straight
and/or not parallel (e.g. concave, convex, divergent or
convergent), so that, with equal loading stroke, the bending
members 10 have a higher or lower degree of deformation, a
different level of stored energy and a different force-draw
curve.
[0125] It is also possible to modify the characteristics of the
crossbow by replacing the bending members 10 with other bending
members of different elastic characteristics.
[0126] Note that the possibility of easily taking apart the
crossbow 1 and replacing its components is linked to the fact that,
in the neutral position, there are no members in elastic tension;
therefore, the taking apart and the assembly do not require either
special tools (e.g. presses) or special caution on the part of the
user.
[0127] The embodiment described above lends itself to several
variants. For example, the slide 25 may not be present and the cams
21 may be engaged to each other directly through edges with
toothing 24; in this case, these edges could also be smooth,
without toothing, but with eccentric profiles. Or both the cams 21
and the slide 25 could have edges partially smooth and without
toothing, but be able to transfer movement by friction.
[0128] The cams 21 themselves could be pivoted to the bending
members 10 with methods different from the described slot 211: more
generally, said portion of each of the bending members 10 may be
associated idle to a portion of a respective cam 21.
[0129] For example, each cam 21 may rotate around a pivot which is
part of the respective bending members 10 themselves (which could
also be just one in number per side of the stock 2).
[0130] As a further possibility, the cams 21 could be pivoted to
the stock 2 so that said first axis of rotation 22 is fixed with
respect to the stock 2 and the cams 21 could also not have an
eccentric profile: in this case, each cam 21 would include at least
one tooth (or an edge) apt to engage and/or cooperate with a
respective bending member 10, in order to push it orthogonal to the
longitudinal development direction 201 away from or close to the
stock 2 itself during the rotation of the cam 21 itself, in order
to create a reciprocal transfer of energy between cams 21 and
bending members 10.
[0131] As a further hypothesis, each cam 21 could cooperate with
the bending members 10 positioned on the opposite side of the stock
2.
[0132] The cams 21 might be more than two in number (for example,
two per side, for a total of four, or one for each bending member
10), and the arms 32 might be more than two in number.
[0133] There may also be auxiliary pushing means (not shown) in
order to further increase the power of the crossbow 1, these
auxiliary pushing means including at least one member with elastic
behavior (spring or hydraulic and/or pneumatic device or other) apt
to accumulate elastic energy during the loading phase of the
crossbow 1 and return it to said pushing means 30 during the
projectile launch phase. Said auxiliary pushing means may be
connected to said slide 25 and, in particular, be housed to the
front of the stock 2, that is, in a position which is substantially
opposite to said contrast means 50; in effect, the action of these
auxiliary pushing means would be similar to the action exercised by
the spring 54, but directed in the opposite direction and active in
the phase in which these contrast means 50 are not operative.
[0134] These auxiliary pushing means may also be side by side to
said contrast means 50, for example, by making that the spring 54
is joined in a stable manner to the cylinder 51 and to the rod 55
so that it may accumulate elastic energy when the arms 32 are
brought from the neutral position to the maximum loading position
and return it in the opposite direction.
[0135] A second embodiment of a device for launching a projectile,
indicated with number 70 and illustrated in FIGS. 8 and 8A,
comprises further technical characteristics which may, however, be
present alone or in combination. Parts having the same function and
structure maintain the same reference number as in the embodiment
described previously and, therefore, are not described again in
detail.
[0136] The device 70 includes a stirrup 210 secured to the stock 2
at the distal end 206. Said stirrup 210 is apt to house a user's
foot: in this way, during the device loading phase, the user can
push the stirrup 210 (and, therefore, the device 70) towards the
ground with a foot and, at the same time, use the hands to apply
force to the flexible member 31 to bring it to the loaded position,
managing to apply more force than when the stirrup 210 is not
used.
[0137] As in the embodiment already described, the cover 61
includes a pair of teeth 65 which come out of the cover 61 near to
its distal end, in order to arrest the run of the flexible member
31 at the end of the launch phase in order to prevent the flexible
member 31 from falling beyond the cover 61.
[0138] The second ends 34 of the arms 32 have a groove 36 apt to
receive a portion of the flexible member 31. To be more specific,
said groove 36 is shaped so as to support the flexible member 31,
preventing it from being disengaged from the ends 34.
[0139] The contrast means 50 and, in particular, the cylinder 51,
are positioned in the region delimited by the bending members 10,
that is, further away from the proximal end 205 than as shown for
the first embodiment (FIGS. 2A to 7). This allows for a greater
compactness of the device 70.
[0140] Finally, in this second embodiment, the upside down
"U"-shaped covering members (indicated with number 63 in the first
embodiment, only one of them being represented in FIG. 4) to be
secured to the connection elements 27, are not present, as the
connection elements 27 are by themselves able to constrain the
cover 61, making it only possible to open it in the neutral
position.
[0141] A third embodiment of a device for launching a projectile
according to the present disclosure is indicated with reference
number 71 and is illustrated in FIGS. 9A to 10, in which only the
essential components are shown in order to understand its
functioning with respect to the previous embodiments. Parts having
the same function and structure maintain the same reference number
as in the embodiments described previously and, therefore, are not
described again in detail.
[0142] The crossbow 71 also comprises a stock 2 with a longitudinal
development direction 201, to which the other components are
connected. As well as the handle 4, the fastening system 6 for a
flexible member 31, and the track 8, it also, obviously, comprises
other components not shown, such as a projectile positioning
system, a trigger and other accessories, as with the previously
described embodiment.
[0143] The bending members 10, entirely similar to the ones already
described, are represented here with a different method for
connection to the stock 2. Their ends, in fact, are in contact with
sidebars 75, which are preferably cylindrical, connected to the
stock 2 and each bending member 10 is pressed against these
sidebars 75 by a wire 76 or similar flexible holding means which
envelops the bending member itself and its corresponding member on
the opposite side of the stock unit 2. The bending methods for the
members 10 are, when all is said and done, similar to those already
described, even if they use a simpler solution for their connection
to the stock 2. Note, however, that this connection method is in no
way limitative for the crossbow 71, just as, the pivoted supports
11 for the bending members 10 are not limitative for the crossbow
1: these solutions may, in fact, be used indifferently in the
embodiments shown here as examples.
[0144] The crossbow 71 has cams 81 which are constrained and
pivoted to the bending members 10 in a manner similar to that
described above, and they can also rotate around an axis 22. In
this case, no slide is present, but a first and a second cam 81 are
hinged on a pivot body 82, which is slidingly associated to the
stock 2 in order to run parallel to said longitudinal development
direction 201. The cams 81 rotate around a determined axis 83 of
the pivot body 82; the axis 83 moves with the pivot 82.
[0145] The already described contrast means (not shown here) may in
case be connected to said pivot body 82. Similarly, the auxiliary
pushing means already previously described may also be connected to
the same pivot body 82.
[0146] Arms 84 are pivoted to the stock 2 at axes of rotation 33,
which are distinct from the axes of rotation 22 of the cams 81. In
this case, in fact, each arm 84 and the respective cam 81 do not
form of a single part, but are separate from each other. The
transmission of the rotation movement from one cam 81 to the
respective arm 84 (and vice versa) is realized through a connection
rod 85 which is pivoted to said cam 81 and to said arm 84. The
connection rod 85 might be replaced by more than one connection
rods 85, in case pivoted to each other.
[0147] The methods of loading and of launch of the crossbow 71 are
substantially similar to those already described for the previous
embodiments and, therefore, are not repeated here.
[0148] Also note that the cams 81 may have a particular "L" shape
as illustrated in FIG. 10, which ensures that, with opportune
dimensioning of these, the crossbow 71 allows an operative position
with the bending members tensioned, the system for the fastening
and releasing the flexible member 31 not tensioned, and arrow in
place, from which operative position the crossbow 71 can be
practically brought back to the launch position with a manual
action.
[0149] In fact, a further movement of the arms 84 beyond a position
of maximum loading ensures that a plane containing both the axes of
rotation 22 intersects the longitudinal axis 201 of the stock 2 in
a region between said axis 83 of the pivot 82 and the proximal end
205. In this position, the recall force exercised by the deformed
bending members 10 on the cams 81 tends to cause a rotation of the
cams 81 in the loading direction instead of in the launch
direction: there is, therefore, no danger of an involuntary
activation of the crossbow 71. In order to launch, it will then be
necessary to first spread the arms 84, so that the axis 83 may pass
over said plane containing both axes of rotation 22, getting closer
to the proximal end 205.
[0150] Obviously, the reciprocal pivoting methods for the cams 81,
their shape and the separation between cams 81 and arms 84 so that
they rotate with respect to axes which are not coincident are
technical solutions which, individually or in combination, could
also be used in a crossbow similar to the other embodiments
described here.
[0151] FIGS. 11A to 11D show a fourth embodiment of a device for
launching a projectile, indicated with reference number 72. Parts
having the same function and structure maintain the same reference
number as in the embodiments described previously and, therefore,
are not described again in detail. The device 72 is shown in the
rest position in FIG. 11A and in the loaded position in FIG.
11B.
[0152] The arms 84 include teeth 86 positioned on the top surface
87 of the arms 84 themselves, said teeth 86 having the function of
stopping the run of the flexible member 31 at the end of the launch
phase in order to prevent the flexible member 31 from falling
beyond the arms 84.
[0153] Also in this embodiment, as in the previous one, the
"L"-shaped cams 81, dimensioned in an appropriate manner, make it
possible for the crossbow 72 to be transported by the user in total
safety, even when it is in the loaded position. As illustrated in
FIG. 11C, the further movement of the arms 84 beyond a position of
maximum loading makes it possible that a plane 92 containing both
axes of rotation 22 of the cams 81 intersects the longitudinal axis
201 of the stock 2 in a region between the axis 83 of the pivot 82
and the proximal end 205 of the stock 2. In this position, the
recall force exercised by the deformed bending members 10 on the
cams 81 tends to cause a rotation of the cams 81 in the loading
direction instead of in the launch direction.
[0154] In other words, in this position, the moment of force
exercised by the bending members 10 on each cam 81, with respect to
the axis 83, rotates the cam 81 in the direction indicated by the
respective arrow 95. As said, then, there is no danger of
involuntary activation of the crossbow 72. In order to launch, it
is necessary, in fact, to first spread the arms 84, so that the
consequent rotation of the cams 81 makes the axis 83 pass over the
plane 92 containing both axes of rotation 22, getting closer to the
proximal end 205.
[0155] This embodiment 72 illustrates a further method for
associating the bending members 10 to the stock 2.
[0156] Each end 101, 102 of a bending member 10 is associated to
the stock 2 by means of a first sidebar and a second sidebar, in
turn associated to the stock 2. The first sidebar and the second
sidebar are in a spaced relation in order to define a housing for
said end 101, 102, so that they touch opposite sides of the bending
member 10 and, in particular, of said end 101, 102.
[0157] In the example, the first sidebar consists of a cylindrical
stem 15, constrained to the stock 2 close to it; in the example,
the second sidebar consists of a support 14, preferably
cylindrical, positioned to the outside of the bending member 10
with respect to the stock 2.
[0158] The end 101, 102 of the bending member 10 is enclosed at the
sides between the support 14 and the stem 15, in particular, in
order to be slightly jutting out in a longitudinal direction 202
with respect to the stem 15.
[0159] The first and the second sidebars also both have a curved
profile (in the example, a cylindrical profile) in order to permit,
during the bending of the bending member 10, a partial rotation of
said end in the housing defined by these.
[0160] To be more specific, the cylindrical supports 14 are
pivotably mounted to the stock 2 in order to be able to make
angular displacements around their central axis 214, so as to
rotate following the movement of the end of the bending member 10
when the latter, bending, varies its tilt with respect to the stock
2; the stems 15 also act as spacers, in order to keep the bending
member 10 slightly displaced from the stock 2.
[0161] The embodiment described, as well as permitting the
connection of the bending members 10 to the stock 2, allows the
bending member 10 to easily bend towards the outside during the
loading phase and to counter bend towards the stock 2 in the stroke
towards the maximum discharge position.
[0162] Note that, if it is required by particular construction
requirements, said first and second sidebars can be positioned at a
tract of the bending member 10 not corresponding to an end of it,
but instead positioned at a certain distance from the end. In
addition, a first tract of the bending member 10 may be associated
to the stock 2 using these sidebars, while a second tract of the
bending member may be associated using different methods (for
example, using the supports 11 already described).
[0163] A fifth embodiment of a device for launching a projectile
according to the present disclosure is indicated with reference
number 73 and is illustrated in FIGS. 12A-12C and 13. Parts having
the same function and structure maintain the same reference number
as in the embodiments described previously and, therefore, are not
described again in detail.
[0164] The device 73 comprises levers 160, each of which has a cam
161 with an appendix 162. The appendix 162 has a guide track which,
in the example, consists of a slit 163 which extends into the body
of the appendix 162 along the appendix itself.
[0165] Each cam 161 is associated to the bending members 10 in a
manner substantially similar to the methods described previously.
In fact, the cam 161 and, therefore, the lever 160, is pivoted to
the bending members 10 using a connection element 27 with
"C"-shaped housings and it can, therefore, rotate around an axis
22.
[0166] The cam 161 extends from the axis of rotation 22 towards the
longitudinal axis 201 of the stock 2, while the appendix 162
extends in the opposite direction.
[0167] To be more specific, the device 73 comprises a pair of
levers 160 arranged symmetrically with respect to the stock 2.
[0168] The cam 161a of a first lever 160a is pivoted to the cam
161b of a second lever 160b at a pivot body 82, which is slidingly
associated to the stock 2 to run parallel to the longitudinal
development direction 201 of the stock 2 itself. The cams 161a and
161b, then, also rotate around an axis 83 which moves with the
pivot 82. Again in this case, as for the embodiments already
described, contrast means and/or auxiliary pushing means may be
used, possibly connected to the pivot body 82.
[0169] The device 73 comprises arms 132, positioned substantially
symmetrical with respect to the stock 2. Each arm 132 has a first
end which is pivoted to the stock 2 at a respective axis of
rotation 33, which is distinct from the axes of rotation 22 of the
cams 161. Each arm 132 includes a second end 34 apt to support and
retain a portion of a flexible member 31, in a manner similar to
the ones described previously.
[0170] The arm 132 is provided with a guide member 135, for
example, including a tooth or a wheel, which extends orthogonal to
a plane on which said arm 132 lies in the direction of the plane on
which the levers 160 lie. Said member 135 is, to be more specific,
associated with a side appendix 134 of the arm 132 which, in the
embodiment illustrated, is envisaged in a region between the axis
of rotation 33 and the second end 34.
[0171] The member 135 is apt to engage the guide track 163 provided
in the appendix 162 of the respective cam 161; to be more specific,
in the embodiment illustrated, the member 135 is a wheel apt to
slide in said guide track 163. This way, each arm 132 is
operatively connected to a respective cam 161. The wheel 135 is
rotationally pivoted to the arm 132 and has a diameter less than
the transversal width of the respective guide track 163, so that it
can slide in said track 163 remaining in contact with just one edge
of the track 163 itself.
[0172] FIG. 13 shows a detail of the particular method for pivoting
the cams 161 to the stock; this method may be also applied in the
same way to the other embodiments for the device presented here. In
a manner similar to what has already been described, each cam 161
has a hole 211 in which the collar 29 of the respective connection
element 27 is housed idle.
[0173] The stock 2 includes, on each side, appendices 250 which
extend substantially orthogonal to the longitudinal development
direction 201. Each appendix has a rail 251 which also extends in a
direction which is substantially orthogonal to said longitudinal
direction 201. Each appendix 250 may also include an end portion at
which a respective arm 132 is pivoted.
[0174] On each side of the stock 2, there is a slide 252 which, on
a first face, includes means for engaging a respective rail 251.
The slide 252, guided by the rail 251, can, therefore, move along
the appendix 250. Preferably, the rail 251 and said engagement
means are made so that the slide 252 can only make a translation
movement along the rail 251 and, therefore, along a direction
orthogonal to the longitudinal direction 201, while the slide 252
is prevented from making movements along said longitudinal
direction 201. For example, the rail 251 and said means have a dove
tail transverse cross section.
[0175] A second face of said slide 252, opposite the first face and
facing a respective cam 161, has a concave slot, with a cylindrical
sector shape, apt to house a corresponding cylindrical portion 165
of the cam 161. The angle described by said cylindrical sector is
less than the angle described by said cylindrical portion 165. This
way, when the cylindrical portion 165 is housed in the cylindrical
sector, the cam 161 can make an angular displacement, of a preset
maximum amplitude, with respect to the slide 252; this angular
displacement takes place between a first position in which a first
edge 167 of the cam 161 is touching a first edge 253 of the slide
252, and a second position in which a second edge 168 of the cam
161 is touching a second edge 254 of the slide 252.
[0176] From said second face, a slit extends into the body of the
slide 252, orthogonal to this second face and facing the first
face. Said slit is apt to house part of a plate portion 166
integral to the cam 161 and positioned outside said cylindrical
portion 165 and transversal to it.
[0177] The slit and the plate portion 166 are made so that they
cooperate with each other in order to prevent relative translation
movements between the cam 161 and the slide 252 along the axis 22;
they are also made so that they do not impede said angular
displacement, of preset maximum amplitude, of the cam 161 with
respect to the slide 252.
[0178] Therefore, during the loading and launch phases, the cam 161
rotates around the axes 22 and 83, both mobile: the axis 83 moves
along the longitudinal direction 201, while the axis 22 moves along
a direction orthogonal to the longitudinal direction 201, parallel
to the rail 251, together with the slide 252. To be more specific,
the slide 252 moves towards the axis 201 during the loading phase
and moves away from it during the launch phase.
[0179] FIGS. 12A, 12B and 12C illustrate, respectively, the
crossbow 73 in a neutral (rest) condition, in a loaded condition,
and in a maximum discharge condition.
[0180] Before a projectile is launched, the crossbow 73 is
initially in the neutral condition (FIG. 12A). During the loading
phase, the pull on the flexible member 31 causes the rotation of
the arms 132 around the axes 33 and the movement of their ends 34
towards the proximal end 205 of the stock 2.
[0181] The wheels 135, also moving towards the proximal end 205,
sliding in the guide tracks 163, apply force to the arms 162, which
causes the rotation of the levers 160 around the axes 22. The
sliding of the wheels 135 in the guide tracks 163, then, makes it
possible that the cams 161 rotate around the axes 22 and bend the
bending members 10, thereby accumulating energy which can be used
to launch a projectile. The loaded condition is illustrated in FIG.
12B.
[0182] Note that, unlike the embodiments described previously, in
this embodiment, the bending members 10 bend towards the stock 2
during the loading phase and counter bend towards the outside in
the launch phase: this is due to the different position of the axis
83 with respect to the plane on which the axes 22 lie in relation
to the rotation movements described by the levers 160.
[0183] It is evident, in any case, that this bending method for the
bending members 10 may also be used for the embodiments described
previously (FIGS. 9A to 11D), and vice versa. In fact, the bending
method away from or closing to the stock 2 during the loading phase
may be selected through an opportune dimensioning and assembly of
the cams, and is substantially unrelated to the other specific
characteristics of the embodiments described; it is, therefore,
"interchangeable" between the embodiments described.
[0184] During the launch phase, the bending members 10 tend to
return to their non-deformed configuration and, therefore, apply a
force to the cams 161, causing the rotation around the axes 22
towards the distal end 206 of the stock 2. As a result of the force
transmitted through the wheels 135, the arms 132 also rotate around
the axes 33 towards the distal end 206 of the stock 2 and pull the
flexible member 31 which, in turn, transmits energy to the
projectile.
[0185] Due to the inertia of the moving parts, the arms 132, the
levers 160 and the bending members 10 pass the neutral position and
reach a maximum discharge position, shown in FIG. 12C, in which the
bending members 10 are deformed towards the outside of the stock
2.
[0186] Subsequently, the bending members 10 return of their own
accord to the non-bent (neutral) position, also bringing the arms
132 and the levers 160 back to the initial position (FIG. 12A).
[0187] A sixth embodiment of a device for launching a projectile
according to the present disclosure is indicated with reference
number 74 and is illustrated in FIGS. 14A-14C, 15 and 16. Parts
having the same function and structure maintain the same reference
number as in the embodiments described previously and, therefore,
are not described again in detail.
[0188] The device 74 comprises levers 170, each of which has a
first portion including a cam 171 constrained and pivoted to
bending members 10 in a manner substantially similar to the methods
described previously, and a second portion including two appendices
172 integral to the cam 171.
[0189] The appendices 172 are substantially identical and parallel
to each other and are also positioned on planes parallel to the
plane on which the respective cam 171 lies. To be more specific,
said second portion includes a block 179 which separates the planes
on which said cam 171 and said appendices 172 lie.
[0190] Each of these appendices 172 has a guide track, which
consists of a first edge 174 with toothing 176; said first edge 174
is optionally facing, at least in part, a second edge 175 with a
groove or a rib 177, thereby defining a region 173 between the
first edge 174 and the second edge 175.
[0191] In a manner similar to the previous descriptions, the cam
171 and, therefore, the lever 170, is pivoted to the bending
members 10 using a connection element 27 and it rotates around an
axis 22.
[0192] The device 74 comprises a pair of levers 170, arranged in a
symmetrical manner with respect to the stock 2, one on each side of
it.
[0193] The cam 171a of a first lever 170a is pivoted to the cam
171b of a second lever 170b at a pivot body 82, which is slidingly
associated to the stock 2 and can run parallel to the longitudinal
development direction 201. The pivot body 82 has a housing apt to
slidingly receive a guide 180 joined to the stock 2 and positioned
parallel to the longitudinal development direction 201.
[0194] The cams 171a and 171b also rotate, then, around an axis 83
which moves with the pivot body 82. Again in this case, as for the
embodiments already described, contrast means or auxiliary pushing
means may be used, connected to the pivot body 82.
[0195] The device 74 comprises arms 142, each having a first end
pivoted rotationally with respect to the stock 2 at a respective
axis of rotation 33, which is distinct from the axis of rotation 22
of the respective cam 171. The second end 143 of each arm 142
supports a pulley 145 which, in turn, supports the flexible member
31. The arm 142 and the pulley 145 lie on planes which are parallel
to each other. The side edge of the pulley 145 has a groove 147 in
which one end 311 of the flexible member 31 is secured and in which
the flexible member 31 itself winds. Note that it is not required
that the pulley 145 has a side edge which defines a closed line: in
fact, the figures show a pulley which has an interrupted side
edge.
[0196] To be more specific, the pulley 145 has a pivot 146 which
rotates jointly with it and which extends orthogonal to the surface
of the pulley and is positioned close to a portion of the edge of
the pulley 145, so that the pulley has an eccentric side edge with
respect to a longitudinal axis 150 of the pivot 146.
[0197] The pivot 146 is housed in a slot, or in a hole, in the
second end 143 of the arm 142 and may rotate in this hole with
respect to the axis 150. The axis 150 makes translation movements
together with the second end 143 of the respective arm 142.
[0198] To be more specific, the arms 142 are two in number and they
are arranged symmetrically with respect to the stock 2, one on each
side of it.
[0199] Each arm 142 is placed in spaced relation from the
appendices 172 of the respective lever 170, but so that the
respective pulley 145 is inserted in a space defined between the
same appendices 172.
[0200] The pivot 146 has two toothed portions 148 (preferably,
cylindrical portions), positioned, respectively, at one face of the
pulley 145 and at the opposite face, that is, above and below the
pulley 145.
[0201] Each of these toothed portions 148 engages the guide track
of a respective appendix 172 and, in particular, the edge 174 with
toothing 176.
[0202] FIGS. 14A, 14B and 14C illustrate, respectively, the
crossbow 74 in a neutral condition, in a loaded condition and in a
maximum discharge condition.
[0203] The crossbow 74, before a projectile is launched, is
initially in the neutral condition (FIG. 14A), in which the bending
members 10 are in the non-deformed configuration and the flexible
member 31 is partially wound on the pulleys 145.
[0204] During the loading phase, the pull on the flexible member 31
towards the proximal end 205 causes the unwinding of the flexible
member 31 from the pulleys 145 and the rotation of each pulley 145
around the respective axis 150; the toothed portions 148 of the
pivot 146 rotate together with the respective pulley 145 and,
engaging the toothed edges 174 of the guide tracks of the
respective appendices 172, move along said guide track, in turn
causing the rotation towards the proximal end 205 of the arms 142
and of the levers 170 around the respective axes of rotation 33 and
22.
[0205] The rotation of the pulley 145 around the respective axis of
rotation 150, that is, around the translating axis 150 of the pivot
146, is, therefore, coordinated with a respective cam 171 for a
synchronized rotation of the cam 171 itself around the respective
first axis of rotation 22. In other words, the pulley 145 moves
synchronized with the respective cam 171, with a combined
translation and rotation movement.
[0206] The rotation of the cams 171, joined to the levers 170,
bends the bending members 10 towards the stock 2, thereby
accumulating energy which can be used to launch a projectile. The
loaded condition is illustrated in FIG. 14B.
[0207] During the launch phase, the bending members 10 tend to go
back to their non-deformed configuration and therefore apply a
force to the cams 171, causing the rotation of the levers 170
towards the distal end 206 of the stock 2.
[0208] The toothed edges 174 have a profile apt to push the pivots
146 towards the distal end 206, causing the rotation of the same
(thanks to the engagement of the toothed portions 148 of the pivots
146 on the toothed edges 174 of the appendices 172) and their
movement towards the end of the region 173 and towards the
longitudinal axis 201 of the stock 2. The pulleys 145 move together
with the pivots 146 and, therefore, have both a translation motion
towards the distal end 206 and towards the stock 2 (in particular
towards the longitudinal axis 201), and a rotation motion around
the axis 150 in a direction opposite to that of the loading phase.
The combination of the translation motion and the rotation motion
of the pulleys 145 draws the flexible member 31 and also winds it
in the grooves 147 of the pulleys 145. The flexible member 31,
hence, transmits energy to the projectile.
[0209] Due to the inertia of the moving parts, the arms 142, the
levers 170, the pulleys 145 and the bending members 10 pass the
neutral position and reach a maximum discharge position, shown in
FIG. 14C, in which the bending members 10 are deformed towards the
outside. In this position, there is the maximum winding of the
flexible member 31 on the pulleys 145, which are almost in contact
with each other.
[0210] Subsequently, the bending members 10 return of their own
accord to the non-bent (neutral) position, also bringing the arms
142, the levers 170 and the pulleys 145 to the initial position
(FIG. 14A).
[0211] This embodiment, that is, the crossbow 74, shows certain
further advantages with respect to the forms previously described.
First of all, the winding of the flexible member 31 on the pulleys
145 permits a reduction of the lateral dimensions of the device
when it is in the neutral position for same loading stroke with
respect to the other embodiments. In addition, the winding itself
also prevents the flexible member 31 from going slack in the stroke
from the neutral position to the maximum discharge position.
[0212] The use of pulleys 145 rotating with respect to the arms 142
allows for greater design freedom in order to obtain the desired
force-draw curve. In fact, the shape of this curve may be adapted
to the requirements by envisaging an opportune profile and rotation
angle for the pulleys.
[0213] By modifying the diameter of the pivot 146 and, therefore,
the number of teeth 148, it is also possible to vary the number of
rotations carried out by the pulley 145 and the number of windings
of the flexible member 31 on it for equal shift along the guide
track (in particular along the toothed edges 174), thereby making
it possible to vary the stroke of the flexible member 31 for same
maximum lateral dimensions of the device.
[0214] Finally, in the launch phase, the rotation movement of the
pulleys 145 combined with their movement towards the longitudinal
axis 201 of the stock 2 makes it possible that the moments of
inertia of these are substantially cancelled out and, therefore,
the structure of the crossbow 74 and the user are subject to lower
stresses.
[0215] Also, the provision, on each side, of two appendices 172
with two toothed edges 174, engaged by two toothed portions 148
placed on opposite faces of the pulley 145 insures that the
movement of the pulley 145 with respect to the arm 170 is more
regular, that their interaction is more efficacious, and that the
forces acting on the pulley 145 in directions not parallel to its
plane are balanced out. However, in principle, there could be just
one appendix 172 with toothed edge 174 and a pivot 146 with just
one toothed portion 148 which engages said edge 174.
[0216] A seventh embodiment of a device for launching a projectile
according to the present disclosure is indicated with reference
number 80 and is represented in FIGS. 17A-17C. Parts having the
same function and structure maintain the same reference number as
in the embodiments described previously and, therefore, are not
described again in detail.
[0217] FIGS. 17A, 17B and 17C show the crossbow 80 in a neutral
condition, in a loaded condition and in a maximum discharge
condition, respectively.
[0218] With respect to the crossbows described in the previous
embodiments, in the crossbow 80, the cams 171 are associated to the
respective bending members 10 at one end of these.
[0219] To be more specific, each bending member 10 has a proximal
end 101 connected to the stock 2 using an already described support
11, and a distal end 102 associated idle to a cam 171 by means of a
connection element 27.
[0220] The fixed support 19 holds a tract 103 of the bending member
10 in a suitable housing, blocking its translation movements
orthogonal to its preferential development direction 202, that is,
away from or close to the stock 2 in a direction 203.
[0221] At most, the opposite internal walls of the fixed support 19
may, if required, have a plan view profile which is curved and
divergent to each other, in order to allow said enclosed tract 103
to assume a certain degree of bending.
[0222] Therefore, the bending of the bending member 10 as a result
of the action of the cam 171 causes the distal end 102 to move away
from or close to the longitudinal axis 201 of the stock 2, while
the tract 103 remains steady.
[0223] Note that, in this case, the bending member 10 is allowed,
at least partially, a degree of freedom of translation, along the
preferential development direction 202, with respect to the
respective connection element 27.
[0224] This latter embodiment is advantageous from the point of
view of the reduced overall length and the rearing of the center of
mass for same loading length.
[0225] To summarize the various different methods presented to
associate a bending member 10 to the stock 2, means for associating
a bending member 10 to the stock 2 are generally envisaged, these
associating means being apt to prevent a translation of a first
tract of the bending member 10 in a direction 203 orthogonal to the
stock 2.
[0226] In certain embodiments, the associating means additionally
allow this first tract to bend, and/or to make an angular
displacement (that is, a rotation) with respect to the stock 2,
and/or a translation in the preferential development direction 202
of the bending member 10.
[0227] In other embodiments, at least one tract of a bending member
10 is constrained in a rigid manner to the stock 2, that is, a
portion or tract of a bending member 10 is tightly joined to the
stock 2, so as to substantially prevent any movement (translation,
rotation and/or flexion movement) of the tract itself with respect
to the stock 2. In other words, in said embodiments the associating
means are apt to join a tract of a bending member 10 to the stock 2
in such a way as to prevent said tract from translating, with
respect to the stock 2, along said preferential development
direction 202 and along a direction 203 orthogonal to said
preferential development direction 202, and from performing an
angular displacement with respect to the stock 2.
[0228] In the embodiments illustrated in FIGS. 2A to 8A, these
associating means comprise supports 11 pivoted to the stock 2 and
block both a first and a second tract of the bending member,
preventing them from carrying out said translation in a direction
203 orthogonal to the stock 2; to be more specific, said first and
second tracts coincide with the ends 101, 102 of the bending member
10.
[0229] In another embodiment, illustrated in FIGS. 9A to 10, said
associating means comprise a wire 76 or other flexible retaining
member, which in case, cooperates with sidebars 75 joined to the
stock 2 in order to block two end tracts 101 and 102.
[0230] In yet another embodiment, illustrated in FIGS. 11A to 11D,
the associating means comprise a first sidebar and a second
sidebar, associated to the stock 2 which, in the example, are a
stem 15 constrained to the stock 2 near the latter and a support 14
positioned on the outside of the bending member 10 with respect to
the stock 2. These means may be envisaged to block end tracts 101,
102 or an intermediate tract 103.
[0231] Obviously, it is possible to combine these associating means
in order to associate a same bending member 10 to the stock 2.
[0232] In a further embodiment illustrated in FIGS. 17A to 17C, a
fixed support 19 is envisaged, apt to block a translation movement
of a first tract 103 of the bending member 10 in a direction 203
orthogonal to the stock 2, and also block an angular displacement
(that is, a rotation) of said first tract 103 with respect to the
stock 2. However, the fixed support 19 may permit the bending of
the tract 103.
[0233] In this latter embodiment, it is further envisaged that a
second tract 102 of the bending member 10 is associated idle to a
respective cam 171, in particular, by means of a connection element
27.
[0234] The principles at the basis of the present disclosure may be
applied not just to a crossbow, but also to a bow, to a catapult,
or to an apparatus for launching model aircraft or unmanned aerial
vehicles or for devices for experimental purposes.
[0235] The examples set forth above are provided to give those of
ordinary skill in the art a complete disclosure and description of
how to make and use the embodiments of the device for launching a
projectile or a launch object in general, and are not intended to
limit the scope of what the inventors regard as their disclosure.
Modifications of the above-described modes for carrying out the
disclosure may be used by persons of skill in art, and are intended
to be within the scope of the following claims. All patents and
publications mentioned in the specification may be indicative of
the levels of skill of those skilled in the art to which the
disclosure pertains. All references cited in this disclosure are
incorporated by reference to the same extent as if each reference
had been incorporated by reference in its entirety
individually.
[0236] The entire disclosure of each document cited (including
patents, patent applications, journal articles, abstracts,
laboratory manuals, books, or other disclosures) in the Background,
Summary, and Description is hereby incorporated herein by
reference.
[0237] It is to be understood that the disclosure is not limited to
particular devices, which can, of course, vary. It is also to be
understood that the terminology used herein is for the purpose of
describing particular embodiments only, and is not intended to be
limiting. As used in this specification and the appended claims,
the singular forms "a," "an," and "the" include plural referents
unless the content clearly dictates otherwise. The term "plurality"
includes two or more referents unless the content clearly dictates
otherwise. Unless defined otherwise, all technical and scientific
terms used herein have the same meaning as commonly understood by
one of ordinary skill in the art to which the disclosure
pertains.
[0238] A number of embodiments of the disclosure have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the present disclosure. Accordingly, other embodiments are
within the scope of the following claims.
* * * * *