US3572714A

US3572714A - Flying target for trap shooting

Info

Publication number: US3572714A
Application number: US787671A
Authority: US
Inventors: Erwin M Lau
Original assignee: Black Products Co
Current assignee: Black Products Co
Priority date: 1968-12-30
Filing date: 1968-12-30
Publication date: 1971-03-30
Anticipated expiration: 1988-03-30

Abstract

A flying target or clay pigeon molded from a frangible pitch and clay mixture having an internal surface with sharp interior angles of substantially 125* and 140* formed by intersecting conical surfaces. The 125* angle is located inwardly of the rim, and 140* angle is located beneath the dome. Between the two angles, there is an inwardly protuberant surface portion which provides a thickened wall section for the step to improve trapping strength. The sharp interior angles represent lines of potential fracture which extend circumferentially. A neck portion separates the rim from the step.

Description

Q United States Patent 1 3,572,714

[72] Inventor Erwin M. Lau 3,169,767 2/1965 Bingham 273/105.4 Dolton,lll. 3,207,516 9/1965 Kaluzng et a1. 273/1054 g 31%? 1968 Primary Examiner-Anton O. Oechsle t d M 1971 Assistant Examiner-Marvin Siskind E 4 252 23 hfoducts Co Attorney-label, Baker, York, Jones and Dithmar Chicago, Ill.

[54.] FLYING TARGET FORTRAPSHOOTING ABSTRAC'l': A flying target or clay pigeon molded from a frangible pitch and clay mixture having an internal surface 11 Claims, 4 Drawlng Figs.

with sharp interior angles of substantially 125 and 140 [52] U-S.C|. 273/3054 fo d b intersecting conical surfaces, The 125 angle is 1 lift. (1 F4 .1 located inwardly of the rim, and 140 angle is located beneath Field of Search the dome. Between the two angles, there is an inwardly protu- 273/1054 berant surface portion which provides a thickened wall section for the step to improve trapping strength. The sharp in- [56] References cued terior angles represent lines of potential fracture which extend UNITED STATES PATENTS circumferentially. A neck portion separates the rim from the 362,744 5/1887 Hebbard 273/105.4 step.

I J/ 3 l FLYING TARGET FOR TRAP SHOOTING This invention relates to improvements in flying targets, sometimes known as clay pigeons or clay targets, suitable for use in trap shooting or the like.

Such targets are in the form of a hollow dome-shaped structure molded from a suitable mixture of pitch and clay, or pitch and limestone dust, which provides a relatively fragile structure.'The weight and diameter are standardized at 100 grams and 4% inches, respectively. 1

The targets are designed to be nested for packing purposes. Because of this requirement, the present practice is to provide for the target an interior surface which follows generally the contour of the outer surface. This results in a structure having a thickness which is more or less uniform, except for irregularities on the outer surface, such as the comers of the rim and the step and possibly beads on the dome.

I have found that a higher-score target and one having improved trapping strength can be provided if instead of having a generally smooth curved interior surface, that the interior surface is provided with two or more sharp interior angles.

If a fragment knocked out of or off of a target by a pellet is so small that it is not clearly visible, the shot will not be scored as a hit; Therefore if the target is provided with lines of potential fracture which tend to increase the size of the fragment, it is possible to get a higher score.

The throwing force is exerted by the trap on the target at a portion adjacent the rim, herein referred to as a step. The step must have sufficient trapping strengt to withstand this force. Sometimes the step is not strong enough and the target breaks in the trap.

According to my invention the sharp interior angles provide circumferentially extending lines of potential fracture which are particularly effective because they are located on the interior surface of the target. Furthermore, the use of two interior angles makes it possible to provide a heavier or thicker section for the step without interfering with the desired nesting relationship. The thicker section for the step improves the trapping strength. Thus this change in the contour of the interior surface improves the target in the two respects above noted.

Other objects, features and advantages will become apparent as the description proceeds.

in the drawings:

FIG. 1 is a plan view of a target embodying my invention;

FIG. 2 is a sectional elevation taken along line 2-2 of FIG.

FIG. 3 is a section similar to FIG. 2 but showing the nesting of two stacked targets; and

FIG. 4 is an outline showing the relative proportions of the neck portion provided by the lower interior angle.

The target is an integral molded member, the various portions of which can be referred to as the rim 11, the step 12, the dome 13, and the chip 14. The angle between the outer surface of the step and the upper surface of the rim can be referred to as the step angle 15.

The hollow interior of the target is composed of several cylindrical or conical surfaces. The inner rim surface 17 is substantially cylindrical, being made with a taper, or draw of substantially 5. Above that is a 60 conical surface 18, the cone measurements being made with respect to the cone axis. Above that is a 35 conical surface 19, and above that is a 75 conical surface The intersection-of

surfaces

17 and 18 provides a first interior angle 21 of substantially 125. The intersection of the

conical surfaces

19 and 20 provides a second interior angle 22 of substantially 140.

The intersection of conical surface 20 with the bottom surface of the chip 14 provides a third interior angle 23 of substantially 165. All

angles

21, 22 and 23 are free of fillets. Each of these interior angles provides a line of potential fracture, although

angles

21 and 22 are more effective than angle 23.

The

surfaces

18 and 19 cooperate to provide a generally convex or protuberant inner surface 24 for the step 12, represented by a 205 interior angle 25. The importance of this configuration is that it provides a heavier cross section for the step 12 so that it is better able to withstand the trapping force imposed on it as explained above. The sharpness of the angle 25 is not important; this could be a rounded corner.

The diameter of the inner rim surface 17 is greater than the external diameter of the step 12 so as to permit nesting of the targets, as shown in FIG. 3. Thus the first interior angle 21 is offset radially outward of the step angle 15. This provides a neck portion 26, shown in greater detail in FIG. 4.

The lower surface of the rim is provided with a bead 27 which rests on the upper surface of the rim in stacking, as shown in FIG. 3, one purpose of which is to prevent chipping or cracking of the corners of the rim during handling incident to packing and unpacking.

The dome may either be a plain curved surface with or without beads, or may be provided with step-type depressions 28as shown in Bingham US. Pat. No. 3,269,767 dated Feb. 16, 1965, as shown herein. These step-type depressions 28 provide radial facets 29 which increase the probability of a hit when the point of impact is offset from the diametral line, as explained in said patent, as well as circumferential facets 30.

Although the exact relationship between the sharp interior angles and the larger fragments is not fully understood, it is believed that the sharp interior angle localizes a certain bending stress which arises when the rim or the step is cracked. The centrifugal force due to the spin of the target develops a certain amount of hoop stress in the rim, and also in the step. If the rim is cracked by the impact of the pellet, the crack releases the hoop stress with the result that immediately adjacent to the crack, the interior angle 21 acts as a hinge point for outward movement of the rim with the result that the interior angle angle is stressed. A similar stress is developed at the interior angle 22 if the crack extends through both the rim and the step.

The smaller the angle, the greater the stress. I have found that interior angles in the range of from to exhibit a measurable degree of frangibility in comparison with angles of, say, to The presence of the protuberant portion 24 enables one to reduce the size of the

interior angles

21 and 22 because there is a complemental relationship between angle 25 and

angles

21 and 22; the angle 25 is preferably greater than 200".

As a result of the centrifugal stress developed at the

interior angles

21 or 22 by the release of the hoop stress, a circumferential fracture will occur; hence, the fragment which is torn from the target will tend to have a much greater width dimension than would be the case if these interior angles were not provided.

The same occurs when a pellet penetrates the rim or the step and splits off some of the interior surface which is likely to be sufficiently small as to be not visible as contrasted with an impact which is strong enough to knock off a visible segment of the rim. This puncturing of the rim or the step will at least partially release the hoop stress and hence develop the centrifugal stress at the

interior angles

21 or 22.

The

interior angles

21, 22, 23, are made as sharp as possible to localize the stresses involved. The characteristic of sharpness, that is, approach to zero radius at the apex, is obtained by accuracy in forming the punch portion of the mold or die. The punch is rough cut, and then finish cut on an engine lathe to about 0.005 inches oversize. Then it is heat treated or case hardened, and thereafter surface ground to the desired dimensions by the techniques which are followed in surface grinding to a tolerance of plus or minus 0.002 to 0.003 inches. This is believed to provide for the interior angles a sharpness, or radius at the apex, of the same order of magnitude, that is, substantially less than 0.010 and quite possibly, an apex radius of from 0.002 to 0.003 inches. The molding mix follows faithfully the contour of the punch with the result that the

interior angles

21, 22, and 23 have the same degree of sharpness as the punch.

Due to the radial offset of angles and 21, it is possible to provide a very pronounced neck portion 26 which is much tinner than the rim, as shown in FIG. 4. This neck portion 26 also contributes to the frangibility of the target because it partially isolates the spinning mass of the rim from the spinning mass of the step. A sudden change in the rotational inertia of either, caused by the impact of a pellet, will stress the neck portion in a circumferential direction, adding to the centrifugal stress when the hoop stress is released.

It will be noted that the neck portion 26, being located beneath the step angle 15, does not weaken the step section.

The outer vertical surfaces of the rim portion 11 and the step portion 12 are cylindrical, and the upper corner of the rim portion preferably is rounded as shown in FIG. 4. Due to shrinkage in the mold, no draw is necessary on the outer surfaces, but because of this shrinkage, a draw is required for the surface 17 which, as pointed out above, is substantially 5.

In the embodiment shown, the rim 11 is substantially threesixteenths inch thick and seven-sixteenths inch high including the head 27. The minimum neck thickness is substantially three thirty-seconds inch measured along the dotted line 31 (FIG. 4) and the neck length measured parallel to the surface 18 is substantially one-eighth inch. The overall height of the target is substantially 1 inch, the diameter being 4% inches. The depth of the depressions 28, measured along the facet 30 is from three thirty-seconds to one-eighth inch, and the depression width varies from one-sixteenth to one-eighth inch. The step 12 is 3% inches in diameter and one-fourth inch high.

lclaim:

1. A flying target of the hollow dome-shaped type having a rim portion, a step portion, a curved dome portion, and a chip portion, the outer surface of said step portion and the upper surface of said rim portion forming a step angle, the internal diameter of the rim portion being greater than the external diameter of the step portion to permit nesting of stacked targets, the internal surface of said target including a plurality of substantially conical surfaces which intersect each other to provide two obtuse interior angles in the range of from 120 to 150 and an inwardly protuberant portion therebetween, the lower interior angle being located beneath and radially outward of said step angle, and the upper interior angle being located beneath said dome portion and at substantially the level of the upper surface of said step portion, said inwardly protuberant portion extending from said lower interior angle to said upper interior angle to provide an increased thickness for said step portion but being clear of the dome of a lower ad- 5 jacent target when nested therewith, each of said interior angles providing a line of potential fracture which extends in a circumferential direction, and being subject to a centrifugal stress when intersected by a vertically extending fracture.

2. A flying target as claimed in claim 1 in which said lower interior angle is substantially and said upper interior angle is substantially 3. A flying target as claimed in claim 1 having a third interior angle between a conical surface and the lower surface of said chip portion.

4. A flying target as claimed in claim 3 in which said third interior angle is substantially 5. A flying target as claimed in claim I in which the sharpness of said interior angles, as measured by the radius at the apex is less than .010 inches.

6. A flying target as claimed in claim I in which said dome portion is provided with a plurality of steplike depressions providing radially disposed facets.

7. A flying target as claimed in claim 1 in which the conical surfaces bounding said protuberant portion intersect to provide an interior angle greater than 200.

8. A flying target as claimed in claim 1 in which one of said conical surfaces underlies said step angle and cooperates therewith to provide a neck portion connecting said step and rim portions, said neck portion at its narrowest point having a thickness dimension substantially less than the thickness of said rim portion.

9. A flying target as claimed in claim 8 in which said neck thickness dimension is substantially 3/ 32 inches.

10. A flying target as claimed 111 clarm 8 in which sard lower interior angle is substantially 125.

11. A flying target of the hollow dome-shaped type having a rim portion, a step portion, a dome portion, and a chip portion, the internal surface of said target including four substantially conical surfaces which intersect each other and having substantially the following angular measurements with respect to the cone axis, starting from the rim portion and reading in order: 5, 60, 35, and 75.

Claims

1. A flying target of the hollow dome-shaped type having a rim portion, a step portion, a curved dome portion, and a chip portion, the outer surface of said step portion and the upper surface of said rim portion forming a step angle, the internal diameter of the rim portion being greater than the external diameter of the step portion to permit nesting of stacked targets, the internal surface of said target including a plurality of substantially conical surfaces which intersect each other to provide two obtuse interior angles in the range of from 120* to 150* and an inwardly protuberant portion therebetween, the lower interior angle being lOcated beneath and radially outward of said step angle, and the upper interior angle being located beneath said dome portion and at substantially the level of the upper surface of said step portion, said inwardly protuberant portion extending from said lower interior angle to said upper interior angle to provide an increased thickness for said step portion but being clear of the dome of a lower adjacent target when nested therewith, each of said interior angles providing a line of potential fracture which extends in a circumferential direction, and being subject to a centrifugal stress when intersected by a vertically extending fracture.

2. A flying target as claimed in claim 1 in which said lower interior angle is substantially 125* and said upper interior angle is substantially 140*.

3. A flying target as claimed in claim 1 having a third interior angle between a conical surface and the lower surface of said chip portion.

4. A flying target as claimed in claim 3 in which said third interior angle is substantially 165*.

5. A flying target as claimed in claim 1 in which the sharpness of said interior angles, as measured by the radius at the apex is less than .010 inches.

6. A flying target as claimed in claim 1 in which said dome portion is provided with a plurality of steplike depressions providing radially disposed facets.

7. A flying target as claimed in claim 1 in which the conical surfaces bounding said protuberant portion intersect to provide an interior angle greater than 200*.

9. A flying target as claimed in claim 8 in which said neck thickness dimension is substantially 3/32 inches.

10. A flying target as claimed in claim 8 in which said lower interior angle is substantially 125*.

11. A flying target of the hollow dome-shaped type having a rim portion, a step portion, a dome portion, and a chip portion, the internal surface of said target including four substantially conical surfaces which intersect each other and having substantially the following angular measurements with respect to the cone axis, starting from the rim portion and reading in order: 5*, 60*, 35*, and 75*.