Spear point for fishing spear guns

This invention comprises a pointed spear head for sport fishing spear guns which is formed of a metal having a Rockwell hardness of at least 30 and distally having a sharply pointed end. At its opposite end, the spear head has an annular groove and intermediate its ends, the spear head has a pair of opposite flats with a single bore extending transversely therethrough, between the flats. A pair of folding wings, each having side flanges with apertures which are aligned with the transverse bore are received over the flatted portions of the head with their apertures aligned with the single through bore of the shaft and with a pin extending therethrough to pivotally secure the wings to the shaft. The spear point is provided with a slidable sleeve retainer which can be slipped over the ends of the wings to retain them in their folded positions. The spear point head of the hardened steel is connected to a shaft adapter of intermediate hardness, e.g., stainless steel having a hardness from about 10 to about 20 Rockwell and, for this purpose, the adapter has a central bore which receives the grooved end of the spear point head. The adapter has its opposite sidewalls internally upset or indented into the annular groove to secure the spear point permanently to the retainer while permitting its freedom of rotation. The opposite end of the adapter has a conventional threaded end such as a distal threaded boss or internally threaded bore to permit its threaded attachment to the main shaft of a spear.

BACKGROUND OF THE INVENTION 
Spear points for spear guns have conventionally been formed with a shaft 
machined from stainless steel. Because substantial machining is required 
for the conventional spear point, the material used for the shaft from 
which the spear point is formed is typically 300 stainless steel, which is 
a relatively soft material having a hardness of about 15 Rockwell. 
The spear points used for sport fishing have a pointed head having a 
reduced diameter shank portion. A sleeve is rotatably mounted over the 
reduced diameter shank portion and apertures are provided on opposite 
sides of the sleeve in which pins are mounted to pivotally attach a pair 
of folding wings. The wings fold against the shaft and are provided with a 
resilient spring and a sleeve retainer is slidably mounted on the point, 
adjacent the rear of the head. The retainer is slid along the shaft to 
overlie the folded ends of the wings and retain them in their folded 
positions, against the bias of a resilient spring. 
The aforementioned construction requires considerable machining. It is 
necessary to manufacture the spear point in at least two parts, requiring 
machining of a threaded attachment between the two parts. It is also 
necessary to machine one or both mating ends of the two head portions to 
reduced diameters to receive the aforementioned sleeve which supports the 
folding wings. The rear portion of the head is also machined with 
necessary attachment means, typically with an internally threaded bore or 
externally threaded shank to attach the head to the main shaft of the 
spear. The aforementioned machining precludes the use of very hard machine 
steel such as steels having hardness values greater than about 30 
Rockwell, e.g. stainless steel grade 17-4 which has a hardness of 44 
Rockwell. 
The use of very hard machine steel for the heads of spear points is desired 
since the softer steels currently in use do not stand up under the abuse 
typically experienced with the spear heads. The spear heads often hit 
rocks, breaking or bending their points, and thus requiring frequent 
replacement and repair. While the use of very hard machine steels for this 
service would greatly reduce or eliminate the frequency of maintenance 
heretofore required and extend the service life of the spear heads, no one 
heretofore has employed such steels because of the extensive machining 
required with the conventional spear head design. 
BRIEF DESCRIPTION OF THE INVENTION 
This invention comprises a pointed spear head for sport fishing spear guns 
which is formed of a metal having a Rockwell hardness of at least 30 and 
distally having a sharply pointed end. At its opposite end, the spear head 
has an annular groove and intermediate its ends, the spear head has a pair 
of opposite flats with a single bore extending transversely therethrough, 
between the flats. A pair of folding wings, each having side flanges with 
apertures which are aligned with the transverse bore are received over the 
flatted portions of the head with their apertures aligned with the single 
through bore of the shaft and with a pin extending therethrough to 
pivotally secure the wings to the shaft. The spear point is provided with 
a slidable sleeve retainer which can be slipped over the ends of the wings 
to retain them in their folded positions. The spear point head of the 
hardened steel is connected to a shaft adapter of intermediate hardness, 
e.g., stainless steel having a hardness from about 10 to about 20 Rockwell 
and, for this purpose, the adapter has a central bore which receives the 
grooved end of the spear point head. The adapter has its opposite 
sidewalls internally upset or indented into the annular groove to secure 
the spear point permanently to the retainer while permitting its freedom 
of rotation. The opposite end of the adapter has a conventional threaded 
end such as a distal threaded boss of internally threaded bore to permit 
its threaded attachment to the main shaft of a spear.

DESCRIPTION OF PREFERRED EMBODIMENT 
Referring now to FIG. 1, the spear point head 10 of the invention has a 
main shaft 12 which is formed of a hard machine steel such as a stainless 
steel having a hardness from about 30 to about 50 Rockwell scale C, 
preferably from 40 to about 50 Rockwell. A very suitable material for this 
purpose is grade 17-4 stainless steel which has a hardness of about 45 
Rockwell scale C. 
Shaft 12 is a cylindrical shaft which is ground at its forward end to 
provide a spear point 14 with a relatively long sharpened point, typically 
with a included angle of the point 14 which is from about 10 to about 20 
degrees. 
At its opposite end 18, the shaft 12 has a single annular groove 20. 
Intermediate its ends, and approximately at the mid- point of the spear 
point head 10, the spear point has a pair of opposite flats such as 22. A 
single through aperture (not shown) transversely extends through the shaft 
12 between the opposite flats such as 22 and this through aperture 
receives a pin 24 that pivotally secures the folding wings 26 and 28 on 
the shaft. Wings 26 and 28 have side flanges such as 30 and 32 and are 
provided with a central aperture such as 34 that is received over the end 
of shaft 24. The opposite ends of shaft 24 are riveted or provided with 
other permanent fasteners to permanently secure the assembly of the 
folding wings 26 and 28 to shaft 12. 
The shaft is also provided with a slidable wing retainer sleeve 36. Sleeve 
36 has an end flange 38 with a central through aperture that is received 
over the end of shaft 12 and an annular loop or cylindrical ring 40 to 
provide for its aplication over the folded ends of the wings, thereby 
retaining the wings in a folded position. 
The invention is also provided with a sleeve adapter 50 which is a tubular 
sleeve having its rear end provided with internal threads 52. At its 
opposite end 54, the adapter receives the grooved end 18 of the spear 
point 10. 
Referring now to FIG. 2, the spear point and adapter are shown in greater 
detail. As shown in FIG. 2, the spear point head 10 has a sharply pointed 
end 14 and its opposite end 18 has a relatively wide annular groove 20. 
The retainer sleeve 38, which is shown in sectional view, is slidably 
received with the central aperture 37 of its flange 38 received over the 
shaft 12. 
The assembly is also provided with resilient means such as springs 27 which 
are received against the inside surfaces such as of the wings when the 
wings are in the folded position and which resiliently bias the wings 
outwardly into their erected positions. 
As shown in FIG. 2, the sleeve retainer 36 has its annular ring 40 
projecting forwardly to grasp the ends of the folded wings 26 and 28, 
against the bias of spring 27. 
The adapter 50 is a tubular sleeve which at its rear end bears internal 
threads 52 for receiving the externally threaded boss end of a spear 
shaft. At its opposite end, sleeve 50 has a pair of opposite upsets 56 and 
58 in its wall portion, opposite the annular groove 20 to serve as a 
permanent retention of the shaft 12 within adapter 50. 
Referring now to FIG. 3, the shape and relative size of the upsets 56 and 
58 is illustrated. FIG. 3 is a sectional view along line 3--3' of FIG. 2, 
which extends though the upset wall portions 56 and 58. As there 
illustrated, each of the opposite walls is internally upset over an 
annular arc 57 of about 120 degrees. The upset portions 56 and 58 are 
symmetrically spaced, thereby providing an angle of 60 degrees between 
each of the upset portions 56 and 58. 
The spear point of the invention can be formed using a relatively soft 
material such as grade 300 stainless steel for the adapter sleeve 50. This 
sleeve can be upset to provide the opposite indentations 56 and 58 using a 
simple punch machine. The upset portions are received within the groove 20 
of the very hard shaft 12 and the upsetting operation does not cause any 
deformation of the annular groove 20. This ensures that the spear point 10 
is freely rotatable within the adapter 50. The only machining required to 
form the hard spear point is the forming of the annular groove 20, 
sharpening of the pointed end 14, grinding opposite flats 22 and boring a 
single through bore 33 through the shaft to receive the pin 34. These 
relatively simple machining operations can be performed with conventional 
tools without requiring any extensive metal cutting operations. This 
permits use of the aforementioned hard machine steels for the spear point 
and, as a consequence, spear points of long life and durability can be 
readily provided. 
The invention has been described with reference to the illustrated and 
presently preferred embodiment. It is not intended that the invention be 
unduly limited by this disclosure of the presently preferred embodiment. 
Instead, it is intended that the invention be defined, by the means, and 
their obvious equivalents, set forth in the following claims: