U.S. patent number 3,738,657 [Application Number 05/251,647] was granted by the patent office on 1973-06-12 for expandable hunting arrow.
Invention is credited to Ernest P. Cox.
United States Patent |
3,738,657 |
Cox |
June 12, 1973 |
EXPANDABLE HUNTING ARROW
Abstract
A hunting arrow has a tubular leading end portion provided with
radially positioned, longitudinally extending slots. Mounted within
the tubular portion are a rearwardly positioned fixed block and a
forwardly positioned movable block. Blade elements comprising
pivotally connected long and short sections extend between the
blocks in alignment with the slots and are pivoted to the blocks,
the long section being pivoted to the movable block and the short
section being pivoted to the fixed block. Elastic bands are
stretched between the two blocks and urge the movable block toward
the fixed block. The blade elements while in longitudinal alignment
tend to keep the movable block from moving. A release element is
pivotally mounted to the short blade section and engages a slot in
the longer blade section to keep the blade sections locked in
longitudinal alignment. A projection on the release element
projects outwardly of the tubular section and when engaged by the
flesh of an animal upon arrow penetration releases the blade
elements to be pivoted outwardly of the tubular section as the
movable block moves rearwardly under the urging of the elastic
bands.
Inventors: |
Cox; Ernest P. (Lola, MT) |
Family
ID: |
22952841 |
Appl.
No.: |
05/251,647 |
Filed: |
May 9, 1972 |
Current U.S.
Class: |
473/585 |
Current CPC
Class: |
F42B
6/08 (20130101) |
Current International
Class: |
F42B
6/08 (20060101); F42B 6/00 (20060101); F41b
005/02 () |
Field of
Search: |
;273/16.5R,16.5B
;43/6 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pinkham; Richard C.
Assistant Examiner: Shapiro; Paul E.
Claims
I claim:
1. A hunting arrow comprising an arrow shaft which is at least in
part tubular and provided in its side wall with a plurality of
circumferentially spaced longitudinal slots, fixed plug and an
axially movable plug mounted within the bore of the tubular arrow
shaft near said slots, plural blade units corresponding in number
to said slots and each blade unit having pivotally connected
sections to form a toggle joint in each unit, the ends of the blade
sections of each unit pivotally connected with said plugs,
resilient tensioning means interconnecting said plugs and
constantly urging the movable plug toward the fixed plug, and
pivoted catch elements on the blade units having tips projecting
through said slots and slightly outwardly of the periphery of said
arrow shaft, said catch elements and blade units having
interlocking parts adapted to hold the units releasably retracted
bodily inside of the arrow shaft with only the tips of the catch
elements projecting radially outwardly therefrom.
2. The structure of claim 1, and each blade unit comprising a
relatively long blade having a sharpened outer longitudinal edge
and a relatively short blade, the long blade of each unit being
pivoted to the movable plug and the short blade being pivoted to
the fixed plug.
3. The structure of claim 2, and the long and short blades of each
blade unit having longitudinally aligned pivotal connections with
said plugs and having toggle joint pivots between the long and
short blades which are spaced laterally outwardly of the aligned
pivots.
4. The structure of claim 3, and said fixed and movable plugs
having pairs of spaced flange plates on their interior opposed ends
with each pair of said flange plates receiving the ends of one
blade unit pivotally therebetween.
5. The structure of claim 1, and said resilient tensioning means
comprising elastic bands extending between said plugs and
intervened circumferentially between the blade units within the
tubular arrow shaft.
6. The structure of claim 5, and attaching hook elements on said
plugs engageable with the opposite ends of said elastic bands.
7. The structure of claim 1, and said interlocking parts comprising
angled slots in the rear ends of the forward blade sections of said
units, and angled locking fingers projecting from corresponding
sides of the catch elements and adapted to enter said angled slots
lockingly when the catch elements are positioned radially of the
arrow shaft with their tips projecting outwardly through the
longitudinal slots of the arrow shaft.
8. The structure of claim 1, and said longitudinal slots and blade
units being four in number and spaced equidistantly
circumferentially of the arrow shaft.
9. The structure of claim 1, and said longitudinal slots and blade
units being three in number and being spaced equidistantly
circumferentially of the arrow shaft.
10. The structure of claim 1, and said longitudinal slots and blade
units being a pair of slots and blade units arranged at
diametrically opposite points on the arrow shaft.
Description
The object of the invention is to provide a superior hunting arrow
for big game bow hunters which is extremely reliable in operation
and will possess greatly increased killing power as compared to
standard fixed blade arrows in use today. The above will be
accomplished with no significant increase in the weight of the
arrow compared to conventional types and no increase in arrow shaft
diameter. The arrow constructed in accordance with the invention
will have a greater velocity and range, a more accurate trajectory
and much greater penetrating power, with the result that it can do
greater damage to the vital organs of the game after penetrating
the hide and rib cage. The arrow, according to the invention, is
also more humane than conventional arrows in that it will kill more
quickly rather than producing a superficial wound or a wound
causing the animal to bleed to death slowly or suffer.
There have been some prior art proposals for expanding blade
hunting arrows and one such example is shown in a prior United
States Patent. The expandable and retractable arrow tip blades in
this patent are cam-operated giving rise to the necessity for
accuately machined parts which are too costly to be practical in
large scale production. In general, the prior art devices of this
type have not been adopted widely because of excessive cost or lack
of sufficiently reliable operation. The present invention is
thought to overcome these deficiencies in the prior art by the
provision of an extremely reliable blade release mechanism and
locking means and a very simple and economical blade expanding
energy source which may derive its power from two, three or four
rubber bands and associated fixed and movable plugs inside of the
tubular arrow shaft.
Other features and advantages of the invetion will become apparent
during the course of the following description.
BRIEF DESCRIPTION OF DRAWING FIGURES
FIG. 1 is a side elevation of a hunting arrow equipped with the
expandable and retractable blades and blade operating means of the
invention.
FIG. 2 is a large fragmentary longitudinal vertical section through
the leading end portion of the arrow shaft and showing the blades
locked in retracted positions within the arrow shaft.
FIG. 3 is a similar view showing the blades in their active or
expanded positions outside of the arrow shaft and under influence
of the blade expanding mechanism in the arrow shaft.
FIG. 4 is an enlarged transverse vertical section taken on line
4--4 of FIG. 2.
FIG. 5 is a horizontal section taken on line 5--5 of FIG. 4.
FIG. 6 is an enlarged fragmentary perspective view of a blade pivot
joint with an associated locking and release element.
FIG. 7 is a leading end view of a arrow with three expandable
blades in accordance with a modification.
FIG. 8 is a similar view of an arrow with two blades according to
another modification.
DETAILED DESCRIPTION
Referring to the drawings in detail wherein like numerals designate
like parts, it will be noted that FIGS. 1-6 depict a hunting arrow
having four circumferentially equidistantly spaced blades whereas
FIGS. 7 and 8 depict arrows having three and two blades,
respectively. The invention is in no sense limited to any one of
these blade arrangements and the arrow having four blades has been
illustrated in details in the drawings for convenience of
illustration and to depict the most complex arrangement
contemplated under the invention, which arrangement is still
exceedingly simple.
Continuing to refer to the drawings, the numeral 10 designates a
thin-walled tubular arrow shaft formed of steel, aluminum or
fiberglass provided near and rearwardly of its leading tip 11 with
a plurality, such as four, circumferentially equidistantly spaced
radial slots 12, which slots extend rearwardly along the arrow
shaft for several inches. Regarding the length of the slots 12 and
the length and size of the expandable blades, to be described, an
important advantage of the invention is that the blades can be made
much larger than conventional fixed arrowhead blades because they
are fully retracted during flight and spring to expanded positions
only after penetrating the body of the game.
Mounted within the bore of the tubular shaft 10 are a two
cylindrical plugs 13 and 14 of identical construction. The plug 13
is fixedly secured to the arrow shaft by a cross pin or rivet 15
while the plug 14 is free to reciprocate axially in the bore of the
arrow shaft. The plug 14 is constantly biased toward the fixed plug
13 by resilient tension elements 16 which may be simple elastic
bands. The opposite ends of the elastic bands are held by hooks 17
anchored to the opposing faces of the plugs 13 and 14. The number
of elastic bands employed will correspond to the number of
expandable and retractable blades, and four sets of blades and
elastic bands are shown in the illustrated embodiment.
The hunting arrow comprises four cir1umferentially equidistantly
spaced blade units, each unit consisting of a long blade 18 and a
relatively short blade 19. The forward ends of the long blades 18
are pivotally connected at 20 to pairs of flange plates 21 on the
plug 14, each pair receiving one long blade 18 therebetween. Near
their rearward ends, the blades 18 are pivoted at 22 to the short
blades 19, and the latter have their rear ends pivotally secured at
23 to pairs of flange plates 24 on the fixed plug 13. With
reference to FIG. 2, it may be noted that the pivotal connections
22 between the long and short blades 18 and 19 of each blade unit
are offset laterally outwardly with respect to the pivots 20 and 23
which are in alignment longitudinally when the blade units are
retracted inside of the arrow shaft 10. This arrangement creates
toggle joints in the blade units which collapse outwardly under the
force of the tension element 16 when certain blade locking
elements, to be described, are released. The outer longitudinal
edges 25 of the blades 18 are sharpened to a knife edge, as
shown.
In order to releasably secure the toggle-jointed blade units
retracted inside of the arrow shaft 10, FIG. 2, small pivoted catch
or locking elements 26 are mounted one each on the short blades 19
by pivot elements 27. The tips 28 of these catch elements project
through the slots 12 and slightly beyond the periphery of the arrow
shaft 10 when the catch elements are in the blade positions shown
in FIG. 2. When in such positions, lateral locking fingers 29 on
the catch elements 26 enter inclined slots 30 in the rear of the
blades 18 to releasably lock the same in their retracted positions
shown in FIG. 2. Even when the blades are fully retracted their
sharpened edges 25 project into the slots 12 and this prevents any
rotation of the movable plug 14 in the bore of the arrow shaft. The
blades 18 and 19 of each unit are freely movable within the slots
12 while shifting to and from the expanded blade position. Even
when the blades are fully expanded or extended, FIG. 3, they are
still subjected to the tension force of the resilient elements 16
and this tension force increases by stretching of the elements 16
when the blade units are retracted. When the blades 18 ar extended
by release of the catches 26, substantially the entire lengths of
theknife edges 25 are exposed outwardly of the arrow shaft for
maximum shock and killing power. In this connection, it is possible
for the blades 18 to be much longer than the blades of conventional
fixed arrow heads since the blades 18 offer no wind resistance when
retracted inside of the arrow shaft 10.
In use, the hunger forces the blades of the arrow to the retracted
position and sets the catches 26 in the locking positions shown in
FIGS. 2 and 6. The geometry of the pivots 20, 22 and 23 in relation
to the pivots 27 of the catches is such that the catches will hold
the blade units retracted until the catches are released by the
arrow entering the hide of the animal. When the arrow is shot by
the hunter while the blades are retracted, it will strike the
animal with maximum velocity and force and the tip 11 will pass
through the hide with ease. The projecting tips 28 of the catches
will encounter the hide and will be turned on their pivots 27 to
the release positions shown in FIG. 3 where the force of the
elastic elements 16 will be released to quickly shift the blades to
their active expanded positions. When this takes place, the blades
are already inside of the rib cage of the animal and the expanded
blades are now positioned to quickly kill by damage in the heart
and lung region or other vital region.
FIG. 7 shows an end view of a hunting arrow having three expandable
and retractable blade units 18' according to the invention, and
FIG. 8 shows an embodiment where the arrow has only a pair of the
expandable and retractable blade units 18a. In all other respects
the embodiments of FIGS. 7 and 8 are identical to the embodiment
described in connection with FIGS. 1 through 6 showing an arrow
having four blade units.
It is to be understood that the forms of the invention herewith
shown and described are to be taken as preferred embodiments of the
same, and that various changes in the shape, size and arrangement
of parts may be resorted to, without departing from the spirit of
the invention or scope of the subjoined claims.
* * * * *