Games using tangible projectile – Projectile – per se; part thereof or accessory therefor – Arrow – dart – or shuttlecock; part thereof
Reexamination Certificate
1999-01-20
2001-08-21
Ricci, John A. (Department: 3712)
Games using tangible projectile
Projectile, per se; part thereof or accessory therefor
Arrow, dart, or shuttlecock; part thereof
C473S582000, C473S586000
Reexamination Certificate
active
06277041
ABSTRACT:
DISCUSSION OF THE PRIOR ART
There have been an extremely large variety of advances made in and for the various games of darts. A dart is a hand held tubular projectile having a point, that is generally designed to be thrown at a target for the purposes of scoring within circularly and radially defined impact areas on the target. A typical dart also includes an attachable shaft carrier aft of and axially oriented to the main body which generally carries guidance vanes, called flights, to help stabilize the trajectory of the thrown dart.
In most cases, the advances have been applied to an external shape of the dart. Various materials are used to create the barrel or central segment of a dart body, such as wood, brass, various amalgams, or tungsten. Into these materials are formed various shapes or patterns, designed to enhance the user's grip or finger placement. Shapes may include dish-outs for finger placement, or knurling.
Points for darts may be either “soft tip” or “steel tip”. The soft tip is usually of plastic, and designed to be used with an electronic scoring board. The steel tip is a hardened metallic member designed to impact a target of densely packed sissal which can accept the scoring point, so the player can visually establish the value of the thrown dart. A steel tip dart must remain in the target during the player's turn sequence (which may include throw of multiple darts), to create a score. Both the electronic and sissal target boards include areas of different value separated by thin metal or plastic dividers (sometimes called “spiders”). If a dart directly impacts a divider, it may bounce off the target without sticking or scoring. Prior attempts have been made to design darts which will remain in the target even if a divider is struck.
In one approach, the soft tip has been formed from a composite of carbon oriented plastic so as to provide a means of flexion when it strikes the target, thereby reducing the chance of rejection by a divider. In this composite dart tip, it has been shown that if the dart tip is sharpened after deformation created by impact with an impediment, the harmonic signature of the dart is changed.
Another prior art dart point approach, has been to provide means to allow for axial movement of the point within a forward containment area of the central dart body, with various controls therefor. Several approaches employ a floating point shaft contained in or by a screw-in race, one being a manually applied pinch effect of the taper of the point in an axial bore of the race, where, impact with the target releases the point so as to allow a hammer effect to drive the dart further into the target. Another approach involves an enlarged aftward head on the axial point shaft, either being rounded or drop hammer formed in a manner called peening, with the head being constrained by a screw-in or press fitted race, or obverse axially oriented machining; and, constrained forwardly by manually induced placement, or by annularly placed resilient washers, or O rings. Other approaches, rather than O-rings, have utilized axial placement of resilient strips in machined grooves to engage the shaft's collar in an attempt to slow the impact moment; whereas, a variation to the O-rings employs radially inwardly projecting fingers that interact with the enlarged collar to control the impact induced moment in the containment cavity. Again, these various structures are employed in a hammering system; but, there is a failure to recognize that this approach, during initial impact with a target or divider, does not allow the linear alignment between the dart's point and body to be altered.
Further, in several of the latter approaches, the O-rings have been placed in a subtending annular race of the enlarged shaft ending head; or, they have been placed in the orienting insert, within a radially outwardly positioned annular raceway; or, they have been placed, in combination, forwardly of that enlarged head and in the raceway. But, in these darts, it is common to find that substantial wear occurs, as the rotation of the variously placed O-rings are working against a stationary shoulder, thereby limiting the value of the point movement.
Another approach has been the usage of a spring body surmounted about a shaft positioner so as to provide an axially oriented progressive loading characteristic for impact with a scoring area. However, springs are known to lose temper due to the short compression cycle experienced by the impact of these darts.
In other darts, the aftward portion of the shaft-ending enlarged head can impact a taper formed in a cavity-ending buttress, this to provide an angular distortion about the body or barrel's axis; a conoid machined shaft that impacts a similarly shaped and obversely positioned conoid body thereaft during impact-induced axial travel, this to provide a non-axial motion when impact with the target's dividers or impediments occurs, particularly in the segments that have the highest scoring value. But, it is known that the use of springs, with their subsequent loss of temper caused by pico-second impact can and do lose this non-axial movement utility; both coil springs and metal strips which are constrained against lateral displacement outside the axis of the load causes direct loss of that ability.
Also, due to the various construction methods, none of these approaches have the ability to ignore the effects of gravity, which may eliminate their effectiveness, because, when the point is retained in the target board, the body of the dart may be angled downwardly relative to the point, and this body may block subsequent darts thrown toward small areas of high score value.
One such example is the internal and forward use of a resilient cylinder with an axially formed bore receiver for receipt of a point shaft, with the aftward end thereof being rounded, with the resilient body simply push-inserted into a receiver cavity of the dart, and placement being arrested by the round end of the shaft against a buttress. There are no provisions against the elastomeric cylinder's propensity to return to an unloaded state; distortion created by non-axial movement upon impact with a target would cause the cylinder to actually creep out of this position; this distortion would tear the bore therein.
Two other approaches employ either a wound spring on the depending shaft of the point, or to a flight-carrying shaft; while showing some utility, neither recognizes that heat and/or non-axial loading will cause displacement or breakage of the point. The wound spring, like its rubberoid counterpart, will actually displace itself from the containment cavity upon lateral displacement. The cupped spring with curved end catchments for the flight shaft, or any half-dome with a central hole receiver for that shaft carrier, faces two considerations: any spring, beyond heat loss, will attempt to return to an unloaded state, thereby becoming an impediment that could interfere with the trajectory of subsequent darts; whereas, the fully cupped spring, beyond the increased potential of resistance, actually embodies a buckle effect. In addition, a strip-type spring, like those above, limits the flight-carrying shaft to only two directions of movement, they being along the axis formed by the width thereof.
Regarding the weights and shapes of darts available, there have been more than one approach. One is an end-threaded shaft that connects the fore and aft ends of the barrel. Various axially-bored pieces of varying density are placed along the shaft to create varying weight and shapes. Stability is improved by an O-ring positioned appropriately.
Another employs a similar internal shaft, and has a variety of weight beads that are placed thereon by the user, prior to insertion into an internal cavity of the barrel, where stability is derived, again, by an appropriately positioned O-ring.
Yet another employs various media, in the hammer approach, that are sometimes separated so as to provide a differing method of weight distribution within t
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