Chalk Marking Projectile

Abstract

A marking projectile is disclosed that comprises an elongated projectile body and a porous powder-releasing head fixed to a forward end of the projectile body with an attachment means. A powder reservoir is defined between the projectile body and the powder-releasing head for holding a marking powder, such as chalk. In one embodiment of the invention, a projectile head is fixed to the forward end of the projectile body, the powder reservoir being defined therebetween. The marking powder preferably has a particle size spread substantially uniformly between 170 and 900 microns. As such, upon impact of the marking projectile with an object, an adequate portion of the powder traverses the porous powder-releasing head to become fixed to the object, thereby visibly marking the object. The marking projectile may be shot with a projectile gun or thrown manually, for example, at the targeted object.

Description

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the invention;

FIG. 2 is a cross-sectional view of the invention, taken generally along lines 2-2 of FIG. 1;

FIG. 3 is a perspective view of the invention, illustrating the invention without a powder-releasing head so as to expose a chalk reservoir;

FIG. 4 is a cross-sectional view of the invention, taken generally along lines 2-2 of FIG. 1, and illustrating an alternate attachment means thereof;

FIG. 5 is an exploded side elevational view of the invention;

FIG. 6 is a perspective view of an alternate embodiment of the invention;

FIG. 7 is a cross-sectional view of the invention, taken generally along lines 7-7 of FIG. 6; and

FIG. 8 is a cross-sectional view of an alternate embodiment of the invention, taken generally along lines 7-7 of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the simplest embodiment of the present invention, illustrated in FIGS. 6 and 7, a marking projectile 10 comprises an elongated projectile body 20 having a forward end 24 and a rearward end 26. Preferably the projectile body 20 is made from a substantially cylindrical closed-cell foam material, or the like (FIGS. 1 and 3). However, other materials and cross-sectional shapes could be utilized for the projectile body 20, such as oval, rectangular, square, or the like. The length of the projectile body 20 preferably is three to seven times the head diameter thereof.

A porous powder-releasing head 50 is fixed to the forward end 24 of the projectile body 20 with an attachment means 70, such as adhesive or insert molding, to define a powder reservoir 40 therebetween (FIG. 7). Preferably the powder-releasing head 50 is made from a woven fabric 90 (FIGS. 2, 7, and 8), an open-cell polymer 100 (FIG. 4), stainless-steel wire gauze or metal screen material (not shown), a woven polymer (not shown), or the like. The selected material preferably has a durometer of less than Shore 50 A and a tensile strength greater than 100 lbs per square inch before failure, such that the powder-releasing head 50 is pliable enough not to damage object struck thereby, but strong enough to endure repeated impacts.

In one embodiment of the invention, a projectile head 30 is fixed to the forward end 24 of the projectile body 20 with the attachment means 70, preferably a suitably strong adhesive (FIGS. 1, 3, 5 and 8). Alternately, the attachment means 70 may be a mechanical fastening means such as a plurality of plastic snaps 80 (FIG. 4), ultrasonic welding, thermal welding, insert molding or the like. In such an embodiment, the powder reservoir 40 is defined between a forward end 34 of the projectile head 30 and the powder-releasing head 50, the powder-releasing head 50 being fixed to the forward end 34 of the projectile head 30, as illustrated in FIGS. 1-5 and 8. The projectile head 30 is preferably made from a resilient elastomeric material, such as rubber, or a pliable polymer material. Such a material preferably has a durometer of less than Shore 50 A so as to not damage object struck therewith.

A quantity of powder 60 is disposed within the powder reservoir 40, and preferably has a particle size spread substantially uniformly between 170 and 900 microns. As such, upon impact of the marking projectile 10 with an object (not shown) at preferably greater than 30 feet per second, an adequate portion of the powder 60 traverses the porous powder-releasing head 50 to become fixed to the object, thereby visibly marking the object. This is accomplished by using materials for the power-releasing head 50 that allow only specific particle sizes to migrate therethrough, such as felt materials and certain metal “sieving” type screens. Normally the size of most of the particles of the powder 60 is greater than the pore size in the powder-releasing head 50. As such, the impact of the dart 10 hitting an object (not shown) breaks the particles up and drives them through the powder-releasing head 50.

The powder 60 is preferably opaque, reflective, and made from a bright or fluorescent colored chalk material, such as calcium sulfate, calcium carbonate, magnesium carbonate, or the like. The powder reservoir 40 has a volume of at least 0.007 cubic inches, making the marking projectile 10 effective for repeated impacts. The marking projectile 10 may be shot with a projectile gun or thrown manually, for example, at the targeted object.

While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. For example, the materials used for the projectile body 20, projectile head 30, powder-releasing head 50, and powder 60 may be varied considerably. Accordingly, it is not intended that the invention be limited, except as by the appended claims.

Claims

1. A marking projectile comprising: an elongated projectile body having a forward end and a reward end;a porous powder-releasing head fixed to the forward end of the projectile body, a powder reservoir being defined therebetween; anda quantity of powder disposed within the powder reservoir.

2. A marking projectile comprising: an elongated projectile body having a forward end and a reward end;a projectile head fixed to the forward end of the projectile body;a porous powder-releasing head fixed to the projectile head, a powder reservoir being defined therebetween; anda quantity of powder disposed within the powder reservoir.

3. A marking projectile comprising: an elongated projectile body having a forward end and a rearward end;a projectile head fixed to the forward end of the projectile body, the projectile head including a powder reservoir in a forward end thereof,a porous powder-releasing head fixed to the forward end of the projectile head and substantially covering the powder reservoir; anda quantity of powder disposed within the powder reservoir.

4. The marking projectile of claim 1 wherein the projectile body is substantially cylindrical.

5. The marking projectile of claim 2 wherein the projectile head is fixed to the forward end of the projectile body with an attachment means.

6. The marking projectile of claim 1 wherein the powder-releasing head is made from a woven fabric.

7. The marking projectile of claim 1 wherein the powder-releasing head is made from an open-cell polymer.

8. The marking projectile of claim 1 wherein the powder-releasing head is made from a metal screen.

9. The marking projectile of claim 2 wherein the projectile body is made from a closed-cell foam material.

10. The marking projectile of claim 2 wherein the projectile head is made from an elastomeric material.

11. The marking projectile of claim 2 wherein the projectile head is made from a pliable polymer material.

12. The marking projectile of claim 1 wherein the powder has particle sizes spread substantially uniformly between 170 and 900 microns.

13. The marking projectile of claim 1 wherein the powder is made from a fluorescent color chalk material.

14. The marking projectile of claim 1 wherein the powder-releasing head is made from a woven polymer.

15. The marking projectile of claim 1 wherein the powder is made from a combination of materials taken from the set of calcium sulfate, calcium carbonate, and magnesium carbonate.

16. The marking projectile of claim 1 wherein the powder-releasing head material has a durometer of less than Shore 50 A.

17. The marking projectile of claim 2 wherein the projectile head material has a durometer of less than Shore 50 A.

18. The marking projectile of claim 1 wherein the length of the projectile is between 3:1 and 7:1 in relation to the diameter of the projectile head.

19. The marking projectile of claim 1 wherein the powder reservoir has a volume of at least 0.007 cubic inches.

20. The marking projectile of claim 1 wherein the powder-releasing head material has a tensile strength greater than 100 lbs. per square inch before failure.