US3425695A - Dart construction - Google Patents

Description

Feb. 1969 R. KESTENBAUM DART CONSTRUCTION Filed June 23, 1966 I! I I '1!!! v United States Patent 1 Claim ABSTRACT OF THE DISCLOSURE An improved hand propelled dart projectile including a hollow longitudinal shaft, a synthetic resinous flight element including a second hollow shaft formed on the outer surface of said first shaft as a result of insert molding, a weighted nose element including a rearwardly facing socket including a threaded portion and anunthreaded portion, a solid metallic rod serving as a reinforcement and having a flattened end inserted within said first shaft at a forward end thereof, said shaft and nose element being threadedly engageable, in wlhich position the fiattened end is maintained within the unthreaded portion of the socket, wherebythe rigidity of the first shaft at with improved durability.

This invention relates generally to the field of dart projectiles and more particularly to an improved con struction capable of production at reduced cost, and with improved durability.

In projectiles of the above mentioned type the flight element, including a plurality of vanes is usually formed as a separate molding, and is installed upon a metal hollow shaft, being held in position by a plug forcibly driven into the rear of the tubular shaft. The shaft is hollow, and is threadedly engaged with a weighted head.

During continued use, there has been a tendency for the hollow shaft to bend, particularly when the device strikes a hard object, such as concrete slabs or the like. Further, because the flight is formed as a separate unit, with passage of time the same has a tendency to loosen on the shaft, and slide relative to it.

It is therefore among the principal objects of the present invention to provide an improved projectile of the class described, in which the above mentioned dis.- advantages have been substantially eliminated.

Another object of the invention lies in the provision of an improved projectile, in which the hollow shank thereof has been reinforced by the insertion of a solid shaft concentrically arranged therewith, whereby the shaft is properly reinforced without substantial transfer of the mass center which is desirably maintained in a forward position.

Yet another object of the invention lies in the provision of an improved projectile of the class described in which the flight may be insert molded upon the tubular shaft to permanently fix the relative positions thereof.

Still another object of the invention lies 'in the provision of an improved projectile possessed of the above advantages, in whidh the cost of fabrication may be of a reasonably low order, with consequent wide sale, distribution and use.

These objects, as well as other incidental ends and advantages, will more fully appear in the progress of 3,425,695 Patented Feb. 4, 1969 "Ice the following disclosure, and be pointed out in the appended claims.

'In the drawing, to which reference will be made in the specification, similar reference characters have been employed to designate corresponding parts throughout the several views.

FIGURE 1 is an exploded view in section of an embodiment of the invention.

FIGURE 2 is an assembled sectional view thereof.

In accordance with the invention, the device, generally indicated by reference character 10, comprises broadly: a nose element 11, a shaft element 12 and. a tail element 13.

The nose element '11 includes a pointed member 15, the rear end 16 of which is threadedly or forcibly fitted into a socket 17 in a weighted member 18. The rear portion of the member 18 is provided with a threaded socket 20 for engaging the shaft element 12.

The shaft element 12 includes a hollow elongated shaft 23, preferably formed from aluminum alloy, and having a threaded forward end 24 and :a tail end 25. Inserted into the head end 24, and extending rearwardly a distance of several inches is an auxiliary solid steel shaft 26, the head end 27 of which is flattened or otherwise distorted to prevent the same from slipping too far inwandly during extended use. As best seen in FIGURE 2, the shaft 26 provides reinforcement to the hollow shaft 23 in the area immediately rearwardly of the weighted member 18, where the same is most subject to bending stresses should the pointed member 15 contact a hard surface angularly disposed with respect to its own principal axis.

The tail element or flight 13, as has been mentioned, is insert molded directly upon the outer surface of the shaft 23, and accordingly requires no other means for interconnection. It includes a shaft enclosing portion 31 extending from a forward terminal 32 immediately rearwardly of the weighted member .18, as well as a rear terminal 33 which surrounds the end 28 of the shaft 23. Extending radially from the outer surface 34 thereof are a plurality of vanes 35, 36 and 37 which are integrally molded therewith.

Assembly of the device, after the above described molding is performed, requires only the insertion of the steel shaft 26 within the shaft 23, and the threaded engagement of the end 24 with the socket 17 in the 'weighted' member 18. While the insert molding operation prevents removal of the flight from the shaft 23, should any of the vanes become damaged, the additional rigidity and strength obtained by such integral construction more than compensates by increased longevity obtained thereby.

I wish it to be understood that I do not consider the invention limited to the precise details of structure shown and set forth in this specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.

I claim:

1. In a projectile, a first hollow metallic shaft threaded at one end thereof, a flight element including a second hollow shaft portion and a plurality of radially extending vanes surrounding said first hollow shaft as a result of insert molding thereon, said second hollow shaft having a rear terminal enclosing an open end of said first shaft; a weighted nose element including a pointed memher extending outwardly thereof, and having an axially arranged socket therein on a side thereof opposite said pointed member, a portion of said socket being threaded to engage the threaded end of said first shaft, and an unthreaded portion adjacent thereto; an elongated solid metallic shaft of diameter corresponding to that of the internal diameter of said first shaft, and having a flattened end thereon of width greater than said diameter, said solid shaft being positioned within said threaded end of said first shaft, wherein said flattened end is maintained within the unthreaded portion of said socket, to prevent relative movement between said solid shaft and the bore of said first shaft.

References Cited UNITED STATES PATENTS 2/1916 Walter 273-68 7/1937 MacC-allum 27380.7 6/1959 Meyer 273-1065 1/ 1961 Carlson 273--72 3/1961 Barnett 273-1065 8/1966 Spier 272-59 X 10 RICHARD C. PINKHAM, Primary Examiner.

PAUL E. SHAPIRO, Assistant Examiner.

US. Cl. X.R.

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