US2665911A - Magnetic dart - Google Patents

Description

S. X. SHORE MAGNETIC DART Jan. 12, 1954 Filed June 5, 1947 INVENTOR. 6idne qX.8b0re His fli'lorney Patented Jan. 12,1954

UNITED MAGNETIC DART Sidney X. Shore, New York, N. Y.

Application June 5, 1947, Serial No. 752,712

14 Claims. 1

This invention relates to darts, such as are used with targets in games of skill, and to dart games.

Irresponsible handling of the usual variety of steel-pointed darts by children and by hilarious party-goers has caused painful injuries and maiming of others innocently present. While intended for targets of cork or wood, the pointed darts have so frequently found human targets as to be shunned for the safety of all. Suction cups and tacky masses have been proposed for eliminating the points, but these are usually so large and lose their eflioacy so quickly as to have found only limited popularity.

It is the object of the present invention to provide an improved dart and dart game, by eliminating the hazardous point and unreliable suction cup and tacky mass of known types.

The dart and dart game proposed by this invention rely on magnetic attraction between the dart and the target. Both are ferromagnetic, and one, preferably part of the dart, is permanently magnetized. In concept a large electromagnet could be used as the target, but is manifestly uneconomical. I have discovered a particular feature that is essential to a successful magnetic dart that has a shaft large enough to be manually gripped.

If a small but strongly magnetized bar is secured to a vaned body in an ordinary (rigid) fashion and is impelled horizontally toward a magnetic target, it is likely to rebound from the target and, fall. I have found it practically necessary to provide a yielding, preferably frictional and inelastic connection between the vaned body and the magnet attached at the forward end of the body. A rigorous explanation of the underlying principles of physics would be practically impossible in view of the numerous variables involved, including firmness of the target, impact forces, relative masses of the vaned body and the magnet, and the particular form of yielding connection. However, I have found that a successful yielding-jointed magnetic dart becomes practically useless when the joint is glued fast.

The invention will be better appreciated, together with further features of novelty, from the following detailed description of an illustrative, presently preferred embodiment thereof, and from the drawings wherein Fig. 1 is an essen tially lateral perspective view of a simple form of the invention and Fig. 2 is an enlarged end view thereof; Figs. 3 and 4 are typical enlarged lateral views of part of the shaft and the magnet before and after direct impact with the target; Figs. 5 and 6 are similar fragmentary views before and after oblique impact with the target; and Figs. 7 and 8 are enlarged lateral and fragmentary sectional views of a modified form of magnetic dart. n

In Figs. 1 and 2 a bar magnet ill, sintered of powdered nickel-iron alloy into the shape shown and magnetized to provide oppositely poled areas N and S in its flat front face, as shown in Fig. 2, is frictionally gripped between the jaws I2, It at one end of shaft I5. Throughout many impacts; this sintered alloy is known to retain excellent magnetic strength. Magnet it has grooves H and I3 for receiving the jaws. Shaft I6 is pref-. erably hollowed at least at its trailing end. At its forward end shaft [6 is slotted at l5 so that the jaws may be made closer together than the thickness of the magnet and when spread to receive the magnet the jaws will firmly grip it. Plural vanes [8, as of metal foil or of thin, stiff paper, guide the dart in flight. Shaft l6 and vanes it constitute flight stabilizing means. Shaft [6 may be made of solid or tubular wood or light metal such as aluminum or other suitable material, and is large enough to be manually gripped while being sumciently light in Weight so as to avoid excessive loading of the magnet. The center of mass of the dart should be well forward. To control the grip of the jaws, a cord or an elastic band (not shown) wrapped around the shaft near the magnet has been found.

of advantage with a wooden shaft.

In Figs. 3 and 4 the particular form of dart is shown during direct flight toward target 23, and after impact. The strength of magnet i l should be ample to support the entire dart against the pull of gravity with shaft l6 extending substantially perpendicularly from the surface of the target as in Fig. 4. Target 20 should be of magnetically susceptible material, that is, of ferromagnetic stock, and if it is coated and colored the coating should not be excessively thick. If there is initially some small spacing Si between the magnet and the bottom of the slot in the end of the shaft, the spacing after impact S2 is usually considerably increased. If in the alternative there is large spacing this will usually be found to have been diminished after impact.

Figs. 5 and 6 are fragmentary views of the dart in oblique flight toward the target, and after impact with the target. A corner 22 of the magnet is likely to strike first, causing the magnet to pivot. magnet and shaft, the entire dart would be forced Were there a rigid connection between.

to pivot before the flat surface of the magnet could contact the target. The natural rebound would precede this retarded pivoting, and the dart would fall. A rubbery connection between magnet and shaft is better but the shaft tends to whip back after the magnet flattens against the target and thus there is some tendency of the dart to be stripped from the target.

In the form shown, jaws l2 and M are tapered. This construction allows relative angular motion between the shaft and the magnet as well as pivotal sliding. The longitudinal and pivotal sliding of the contacting surfaces frictionally consumes some of the rebound kinetic energy, contributing importantly to the excellent sticking qualities of the magnetic dart.

Figs. '7 and 8 illustrate a modified form of dart, embodying further useful features. A pair of tongues l2 and I4 are integral with shaft Hi to grip the surfaces of recesses II and I3 of magnet l firmly but frictionally. Magnet l9 has a. pair of ribs 24 between jaws l2 and M which prevent total removal of the magnet by engagement with in-turned shoulders of the jaws, yet provide for the necessary longitudinal sliding or "lost-motion. Jaws l2 and H are narrower than the recesses in the magnet, allowing angular frictional sliding as in Figs. 5 and 6. For assembling the magnet, the jaws are forcibly spread and then released.

In addition to the foregoing preferred forms that have been described in detail, the magnet can be provided with spring jaws to frictionally embrace the body of the dart either internally of a bore therein or externally; or part of the body of the dart can be similarly confined in a hole in the magnet. These and other yielding connections between the body of the dart and the magnet will occur to those skilled in the art.

What I claim is:

1. A dart having a magnet, a face of which constitutes the front end of the dart, and a rearwardly extending vane structure disposed wholly to the rear of said face and having a sliding lost-motion connection to said magnet and said magnet being .of sufficient magnetic strength to support the entire dart when extending horizontally from a ferromagnetic target.

2. A dart having a magnet, a face of which constitutes the front end of the dart, and a, rear- .3'. A dart having a magnet, a face of which constitutes the front end of the dart, and a rearwardly extending vane structure disposed wholly to the rear of said face and having a swingably yielding connection to said magnet, the strength of said m gnet being sufficient to support the entire dart when extending horizontally from a ferromagnetic target 4. A dart including a vaned body having a pair of forwardly extending laterally spaced jaws, and a transversely extending bar magnet frictionally gripped between said jaws with a surface of the bar magnet positioned in advance of any other part of the dart for engaging a ferromagnetic target, the strength of said magnet being sufficient to support the entire dart when extending from such target.

4 l 5. A game comprising a target having a playing surface of magnetically susceptible material and a projectile adapted to be freely propelled through the air at said target, said projectile including a permanently magnetized body having a flat target-engaging area and being of sufficient magnetic strength to support the projectile in contact with the target against the pull of gravity, and flight stabilizing means disposed whollyrearward of said face and extending generally rearwardly with respect to said targetengaging face for maintaining said target-engaging face foremost during flight, the flight stabilizing means having a swingable connection r to said body so that the magnetized body is capable of swinging into fiat contact with the fiightaand having sufficient magnetic strength to support the dart in contact with a ferromagnetic target against the pull of gravity, and flight stabilizing means disposed wholly to the rear of a said area and including a vane portion and a swingable connection between the van portion and the body for providing for relative swing between the magnet and the vane portion as and in the event that the target engaging area strikes a target slantwise and swings into flat face-toface contact with the target.

7. A dart including a permanent magnet having a fiat area constituting the target engaging face of the dart, flight directing means disposed on the side of said magnet opposite the target engaging face for maintaining said face foremost during flight, and a pivotal connection between the magnet and the flight-directing means enabling abrupt swinging of the magnet into fiat contact with a flat target after striking the target at an angle and without enforcing concur.- rent and equal swinging of the flight directing means, said permanent magnet having suflicient strength to seize a magnetic target upon impact therewith and support the entire dart,

8. A dart including an elongated vaned body and a magnet frictionally connected to the forward end of said body, said magnet having sufficient magnetic strength to be self-supporting and to support the vaned body when the dart engages a ferromagnetic target, said magnet and said vaned body having transversely extending portions mutually spaced apart longitudinally and.

normall interposed in the longitudinal pathv .of separation of the vaned body and the magnet for preventing unintentional disassembly thereof.

while affording limited relative longitudinal motion between the magnet and the vaned-body upon impact of the dart against a target, said magnet and said vaned body having longitudinal surfaces in mutual sliding contact.

9. A dart including a vane structure and a magnet having sliding frictional connection to said vane structure, said magnet being of sufficient strength to adhere the entire dart to a ferromagnetic target against the pull of gravity, the target-striking face of said magnet being disposed substantially forward of said vane structure.

10. A dart including flight-stabilizing means and a magnet connected to the forward end of said flight-stabilizing means, said dart being capable of adhering to a ferromagnetic target despite the pull of gravity by virtue of the strength of said magnet, said flight-stabilizing means having transverse portions disposed opposite to and normally spaced from interlocking portions of said magnet, said portions being effective to prevent unintentional disassembly of said magnet and said flight-stabilizing means whil affording limited relative motion therebetween upon impact with a target.

11. A dart including a magnet having a face constituting the front end of the dart, and a rearwardly extending varied body frictionally connected to said magnet, said magnet face being positioned forward of any other part of the dart, and said magnet being of suficient magnetic strength to support the entire dart when extending horizontall from a ferromagnetic target, the frictional connection being sufiiciently tight to hold the vaned body and the magnet in a normal relative orientation yet no so rigid as to entirely prevent relative motion between the magnet and the vaned body upon impact of the magnet against a target.

12. A dart comprising a magnet having a target-engaging face constituting the foremost portion of the dart, said magnet, being of sumcient strength to retain the dart against a ferromagnetic target, and rearwardly extending flight stabilizing means disposed Wholly to the rear of the target-engaging face of the magnet, said flight stabilizing means being swingably yieldably connected to said magnet.

13. A game comprising a target having a playing surface of magnetically susceptible material and a projectile adapted to be freely propelled through the air at said target, said projectile comprising, a permanently magnetized bod having a target engaging face and being of suflicient magnetic strength to support the projectile when extending horizontally from the target against the pull of gravity, and flight-stabilizing means secured to said body and extending generally rearwardly with respect to said target engaging face for maintaining said target engaging face foremost during flight, said flight stabilizing means including vane surfaces having swingable connection to said magnetized body afiording through the air at said target, said projectile including a permanently magnetized body having a substantially fiat target-engaging area and being of sufficient strength to support the projectile in contact with the target against the pull of gravity, vanes positioned rearwardly with respect to the target-engaging area for maintaining said target-engaging area foremost during flight, and yielding connecting means between said vanes and said magnetized body and disposed wholly rearward of said target-engaging area, said yielding connecting means being firm enough to hold the magnet and the vanes in a normal relative orientation yet not so rigid as to entirely prevent relative motion between the vanes and the magnetized body upon impact against a target.

SIDNEY X. SHORE.

References Gited in the file of this patent UNITED STATES PATENTS Great Britain July 28, 1939

Images