Multiple blade foldable throwing knife

A throwing knife having a multiple number of pointed blades for hitting a target, and being readily foldable so as to be carried conveniently when not in use. Each blade has a number of locking studs on one side of the blade, and a corresponding number of mating locking dimples on the other side of the blade. The blades are pivotally mounted on an axle about which the blades can be rotated either to the folded position with all blades stacked one above the other, or to the throwing position wherein the blades radiate outwardly from the axle. The studs and complementary dimples of adjacent blades engage one another in the folded and the throwing positions so as to secure the knife in such positions.

This invention relates in general to knives and in particular to knives 
especially intended for throwing. 
Those persons skilled in the use of knives will realize that a substantial 
amount of skill and expertise is necessary in throwing a knife at an 
object. A thrown knife must obviously arrive point-forward at the target, 
after executing at least a half-turn in the air upon leaving the thrower's 
hand. This feat becomes more difficult as one attempts to hit targets at 
variable distances from the thrower, since the turning speed and the 
number of turns which the knife must make in the air have to be estimated 
and correctly accomplished after visually gaging the distance from the 
thrower to the target. 
It has been proposed to provide knives designed especially for throwing, 
with such knives having a plurality of blades extending outwardly from a 
central hub to form a star-like array of blades. Such multiple blade 
throwing knives are held by one blade while throwing, and the entire array 
of blades rotates while moving toward the target with the result that one 
of the blades usually arrives nearly point-forward at the target. Such 
multiple blade throwing knives of the prior art have been constructed to 
remain partially or fully in throwing configuration at all times, however, 
and so such knives are relatively awkward or dangerous to carry or store 
when not in use. 
Accordingly, it is an object of the present invention to provide an 
improved multiple blade throwing knife. 
It is another object of the present invention to provide a multiple blade 
throwing knive which can be fully folded when not in use. 
It is yet another object of the present invention to provide a 
multiple-blade foldable throwing knife in which each separate blade may be 
identical for ease of manufacture and construction. 
Stated in general terms, the multiple blade throwing knife of the present 
invention includes a number of separate blades each having a pointed 
forward end and a back end. The blades are interconnected adjacent their 
back ends for pivotable movement about an axis which is perpendicular to 
the blades, and each blade contains locking structure which is 
complementary to locking structure on the other blades so that the blades 
can be interlocked either in a throwing position or in a folded position. 
When folded, the several blades are stacked together with all pointed ends 
aligned, so that the pointed ends of the folded knife can be readily 
placed in a holster or similar protective device. Stated more 
specifically, the locking structure of each blade is provided by a number 
of projections extending outwardly from one side, and by a corresponding 
number of recesses formed inwardly into the other side in alignment with 
the projections. The projections and recesses on each blade are arranged 
so that the projections and confronting recesses on adjacent blades are 
interlocked with each other in a complementary manner whenever the blades 
are either in folded position or in throwing position, so that the blades 
are locked together in either such position.

Turning to FIG. 1, there is shown generally at 10 a multiple balde foldable 
throwing knife according to the present invention. The knife 10 has four 
separate blades 11a, 11b, 11c, 11d, although it will be apparent that the 
use of four blades is not a critical aspect of the present invention. The 
four-blade throwing knife 10 is shown in its throwing configuration in 
FIG. 1, and the knife presents four pointed ends extending radially 
outwardly in symmetrical array from the central portion 12 of the unfolded 
throwing knife. 
FIG. 2 shows the knife 10 in exploded view of the throwing configuration. 
Each of the blades 11a-11d is preferably identical according to the 
present invention, and so the following detailed description of blade 11a 
is equally applicable to all such blades. The blade 11a, as best seen in 
FIG. 3, has a pointed forward end 15 and a blunt back end 16 which may be 
perpendicular to the longitudinal axis of the blade. An opening 17 extends 
through the blade 11a a short distance away from the back end 16, and an 
axle 18 extends through the openings 17 in each of the four blades. 
The axle 18, as best seen in FIGS. 2 and 5, has a head 19 which is larger 
than the opening 17 and which abuts the first side 26 of the lowermost 
blade 11a. Adjacent the head 19 of the axle 18 is a shank portion 20 
having longitudinal extent which is slightly less than the thickness of 
the blade 11a, and which is dimensioned to provide an interference fit 
with the hole 17 of that blade (or with the corresponding hole in any of 
the identical blades). The remaining length of the axle 18, including the 
threaded outer portion 21, is less than the diameter of each opening 17 so 
that the blades 11b, 11c, and 11d are pivotably received on the axle as 
best shown in FIG. 5. 
Turning to FIGS. 3A and 5, it is seen that blade 11a (and each other blade) 
has four studs 25 projecting outwardly a distance from the first side 26 
of the blade. The studs 25 are substantially identical in configuration 
and are symmetrically positioned with respect to the opening 17 in the 
blade. 
On the second side 27 of each blade are formed four dimples 28 each of 
which is coaxially aligned with a corresponding stud 25 on the first side 
26 of the blade. The dimples 28 are of complementary configuration to the 
studs 25, so that the array of studs 25 of one blade will mate with the 
array of dimples 28 of another identical balde, as shown in FIG. 5. The 
interlocking configuration of studs and dimples permits any two adjacent 
blades to be locked into any of four positions 90 degrees apart from each 
other. As best seen in FIG. 5, the wall 29 of each dimple 28 is tapered 
outwardly to allow a snug yet readily disengageable fit between dimples 
and adjacent studs, within practicable manufacturing tolerances. 
The depicted knife 10 is assembled by initially inserting the axle 18 into 
the opening 17 of the blade 11a and pressing the interference-fit shank 
portion 20 into that opening until the head 19 of the axle is flush 
against the first side 26 of the blade 11a. The remaining three blades 
11b, 11c, and 11d are then placed on the axle 18 which extends outwardly 
from the first side 26 of the blade 11d. The dimples of all blades are 
facing the head 19 of the axle. 
A washer 33 is then placed over the threaded outer portion 21 extending 
outwardly from the blade 11d, and the wing nut 34 is threaded onto the 
threaded outer portion. The outermost end 35 of the threaded outer portion 
21 should then be staked or otherwise deformed to prevent the wing nut 34 
from becoming removed from the axle thereafter. 
The knife 10 is normally stored and carried in the folded position shown in 
FIG. 4, in which all of the blades are stacked together with the pointed 
front ends aligned. The blades are locked in the folded position, inasmuch 
as the studs 25 of blades 11b, 11c, and 11d are within dimples 28 of 
blades 11a, 11b, and 11c, respectively. It will be apparent that a sheath 
or similar carrying device can readily be fashioned to receive and guard 
the aligned pointed ends 15 while the knife 10 is folded as shown in FIG. 
4. When it is desired to unfold the knife 10 into throwing configuration, 
the wing nut 34 is loosened sufficiently to allow the studs 25 of blades 
11b, 11c, and 11d to be withdrawn from the mating dimples 28 of the 
respective adjacent blades. The blades are then rotated until all blades 
are mutually 90 degrees apart as shown in FIGS. 1 and 2, at which point 
the dimples and studs are again in locking alignment. The wing nut 24 is 
once again tightened to retain the locking alignment of the studs and 
dimples, and the knife 10 is ready to be thrown at a target. 
The knife 10 is folded by reversing the foregoing procedure. 
It will be seen that there has been disclosed and described a multiple 
blade foldable throwing knife which is readily placed either in a throwing 
configuration in which all blades extend radially outwardly from a central 
portion, or in a folded position in which the knife occupies a minimum 
volume and the points of the blades are aligned for safety and 
protectability. The press-fit arrangement of the axle portion 20 within 
the opening 17 in any one of the blades allows all blades of the knife to 
be identical, further simplifying the manufacture and assembly procedure. 
Furthermore, the use of identical blades simplifies the stocking and 
supply of replacement blades in the event that an individual blade of the 
throwing knife becomes broken or damaged. 
It will be apparent that a throwing knife according to the present 
invention can be provided with a greater or lesser number of blades than 
four, with a corresponding adjustment in the number of dimples and studs 
on each of the blades to permit blade interlocking in either the folded or 
throwing positions as described above. The number of studs on the first 
side 26 of each blade, as well as the number of dimples on the second side 
27, will each be equal to the multiple number of blades of the knife in 
any case. 
It will be understood that the foregoing relates only to a preferred 
embodiment of the present invention, and that numerous changes and 
modifications may be made therein without departing from the spirit and 
the scope of the invention as set forth in the following claims.