Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Anti dry-fire device for crossbows
FIELD OF THE INVENTION
[001] The present invention relates generally to crossbows but more
particularly to a device to stop dry-fire.
5BACKGROUND OF THE INVENTION
[002] Crossbows are used for hunting nowadays. With the new fiberglass
bows which are harder to bend, more pressure is exerted on the arrow
by way of the string which translates into an arrow going over a much
longer distance.
10[003] The problem with that is if an arrow is not present and that for some
reason the string is triggered, that is called a dry-fire, and the bow,
without the benefit of being slowed down by the departing arrow,
unbends too rapidly, which can, more often than not, result in one or
both sides of the bow to crack or even break.
15[0041 In order to solve this problem, there are some crossbows that have an
anti dry-fire system as part of their construction.
[005] For example, one patent has the crossbow include a trigger mechanism
comprised of a pivotal string catch member positioned relative to the
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trigger mechanism to selectively extend into a string catching position
which will catch and retain the bowstring should it be released from the
trigger mechanism without an arrow in a firing position in the crossbow.
The string catch member includes an arrow contacting surface to
engage an arrow positioned to be fired from the crossbow, wherein,
movement of the arrow to the firing position causes the string catch
member to be moved out of the string catching position. This allows
selective release of the bowstring from the guide slot and prevents
inadvertent release when no arrow is present in the firing position. The
string catch member may be manually removed from the guide slot so
as not to interfere with the bowstring, allowing a convenient mechanism
to uncock the crossbow without firing.
[006] But there does not appear to be any kits that allows for the
retrofitting of
an anti dry-fire device on existing crossbows.
15SUMMARY OF THE INVENTION
[007] In view of the foregoing disadvantages inherent in the known devices
now present in the prior art, the present invention, which will be
described subsequently in greater detail, is to provide objects and
advantages which are:
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[008] To provide for an anti dry-fire device that is retrofittable to existing
crossbows.
[009] To provie for a simple yet efficient system of anti dry-fire for
crossbows.
[0010] To attain these ends, the present invention has the anti dry-fire
device
5 mounted on a viewfinder mount and having a catch rotationally attached
to a catch holder by way of an attachment pin. A catch biasing means to
bias the catch. A lock-unlock means slidingly engaged on the top of the
viewfinder mount. The lock-unlock means moving the catch from an
operative mode into an inoperative mode.
[0011] The anti dry-fire device is also comprised of a biased ball bearing is
selectively biased from a first cavity to a second cavity when the lock-
unlock means is moved from unlock mode to lock mode.
15[0012] The anti dry-fire device preferably has a stop and block restrain the
range of motion of the lock-unlock means.
[0013] The anti dry-fire is ideally suited for retrofitting on an existing
crossbow"s
viewfinder mount.
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[0014] The anti dry-fire device has a mode of operation consisting in the
steps
of a user pulling a lock-unlock means in a direction opposite the way an
arrow is to be released so as to allow a catch to pivot in an orientation
that causes the catch to block the release of a string after the user has
pulled the string so that the string passes the catch which allows
passage of the string in one direction but not in the opposite direction;
the user loads an arrow;
the user, when ready to fire, pushes the lock-unlock means in the way
the arrow is to be released so as to pivot the catch out of the way of the
string;
[0015] the user pulls the trigger to release the string and throw the arrow.
[0016] There has thus been outlined, rather broadly, the more important
features of the invention in order that the detailed description thereof
that follows may be better understood, and in order that the present
contribution to the art may be better appreciated. There are additional
features of the invention that will be described hereinafter and which will
form the subject matter of the claims appended hereto.
20[0017] In this respect, before explaining at least one embodiment of the
invention in detail, it is to be understood that the invention is not limited
in its application to the details of construction and to the arrangements
of the components set forth in the following description or illustrated in
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the dravWngs. The invention is capable of other embodiments and of
being practiced and carried out in various ways. Also, it is to be
understood that the phraseology arrd terminology employed herein are
for the purpose of description anq should not be regarded as limiting.
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(0018] As such, those skilled in the art wift appreaiate thet the concep5on,
upon
which this disclosure is based, may readily be utiliaed as a basis for the
designing of other structures, methods and systems for carTying out the
several purposes of the present Invention, It is iniaortant, therefore, that
the claims be regarded as including such equivalent constructions
insofar as they do not depart from the spirit anq scope of the present
invention.
[0019] These togetherwith other otsjects of the invention, along wikh the
various
features of novelty which characterize the invention, are pointed out with
particularity in the claims annexed to and forrnirtg a part of this
disclosure. For a better understanding of the invention, its operating
advantages and the spedfc objects attained by Its uses, reference
should be made to the accompanying drawings and descriptive matter
which contains illustrated preferted embodiments of the invention.
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BRIEF D~SC~IP f I~U y_Q~LIRAWINGS
[:0201 Figs. 1ab Cmss-sectiorral side views of the device with the catch
disengaged and engaged respectively.
[0021.1 Figs. 2a-c Perspective views of the invention_
ETAIL U , ESCRPIION
[0022] An anti dry-fire device for crvssbows (10) is mounted on a viewfinder
mount (12). Uewfinder mounts of this type are weii known in the art but
this particular one has been modified to receive the exclusive
components of this irnrention_
t0100231 A catch (14) Is rotational;y attached to a catch holder (44) by way
of an
attachment pin (16). A catch biasing means (18) to bias the catch (14)
as shown in fig 1 b,
[00241 A lock-unlock means (20) is slidingly engaged on the top of the
viewfinder mount (12). In fig. 1a, the lock-unlock means (20) has lifted
the caieh (14) into its non operative mode. The string (19) will not be
blocked when it is reteased. The iock-unlodc means (20) accomplishes
that by pushing forward on the catch (14) so as to pivot it out of the way
of the string (19).
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10025] A biased ball bearing (22) is selectively iaiased fram a first cavity
(24) to
a second cavity (24') when the lock-unlock means (20) is moved, as can
be seen by comparing fig. ia with fig. 1b. A stop (26) and block (28)
restrain the range of motion of the lock-unlock means (20).
[DO26] In operation, a user pulls on the crossbow string (19) so as to engage
it
under tension, as is knowrt in the art. This can be done even If the catch
Is down since it operates like the pawl of a ratchet for one way passage
of the string (119) but with a blockage the other way ilround. 1Mhen ready
to fire, the user simpiy pushes on the lock-unlock means (20) to lift the
catch (14) and allow the string (19) to shoot the arrow (not shown).
(0027) eesides preventing dry fire, ft device can also aot as a safety device
to
prevent accidental triggering when the arrow (not shown) is loaded.
[0028] As to a further discussian of the manner of usage and operation of the
present inven#ion, the same should be apparent fmm the above
description. Accordingly, no further discussion rel2tting to the manner of
usage ertid operation vuiU be provided.
[W29) With respect to the above description then, it Is to be realized that
the
optimum dimensional relationships for the parts of the invention, to
include vMations in size, meiteriats, shape, form, function and manner of
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operation, assembly and use, are deamed madily apparent and obvious
to one skilled in the art, and all equivalent relationships to those
illustrated in the drawings ind described in the specification are
intended to be encompassed by the present invention.
s
[QU30] Therefore, the foregoing is considered as illustrative only of the
principles of the invention. Further, since numerous modifications and
changes will readily occur to those skilled In the art, it is not desired to
limit the invention to the exact construction and operation shown and
clescribed, and accordingly, all suitable rnod'rfic2itions and equivalents
may be resorted to, falting within the scope of the invention.
ZU
