US20240050824A1

US20240050824A1 - Method for Optimizing a Rocking Target

Info

Publication number: US20240050824A1
Application number: US17/884,652
Authority: US
Inventors: Raymond L. Francis
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-08-10
Filing date: 2022-08-10
Publication date: 2024-02-15

Abstract

A device that is capable of being in three states: (1) a first stable state, (2) a second stable state, wherein said device teeters back and forth when hit by a force, and (3) and a third stable state, wherein said device will topple completely over when hit too hard by a force. The device comprises a target piece and a base. The base is configured to lay flat on a surface and contains a curved section, a ledge, and a ledge perimeter. The target piece may contain a top piece attached on the opposite side which the base is attached, which may contain a hollow cavity, a shot glass holder cavity, or take the shape of a target for use in target practice. The device may be used in many different applications including in recreation games, drinking games, target practice, and fighting practice.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 17/215,726. The parent application was filed on Mar. 29, 2021. It listed the same inventor.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

MICROFICHE APPENDIX

Not Applicable

BACKGROUND

1. Field of the Invention

This invention relates to the field of target games or drinking games. More specifically, the invention relates to a rocking target in which the object of the game is either: (1) to hit the present device without causing it to topple completely over, or (2) to hit the present device with such a force that the device topples completely over.

2. Description of the Related Art

The present invention is applicable to a wide variety of rocking targets that move when hit with a force and should not be viewed as being limited to any one type. The present invention may be used in many applications, including for target practice, fighting practice, throwing practice, recreational gaming, and even for use as a drinking game. A common prior art rocking target is displayed in FIG. 1 . The inflatable punching bag 22 has a weighted base 24, typically weighted through the addition of a weight, liquid, or sand, which forms the center of gravity of the inflatable punching bag 22. The low center of gravity prevents the punching bag 22 from falling over no matter how far it tips from its upright position.
The prior art is different from the present invention. Users practicing target aim, fighting techniques, or playing a game find utility in a device that will react when hit and may either return to its upright position or topple over when hit at a certain angle or with a certain amount of force. For the foregoing reasons, there is a need for a device that will rock back and forth, as in the prior art, but is also capable of toppling over if it is hit at an angle that causes it to sway too far from its upright position. The present invention solves this problem by rocking back and forth and also having the ability to topple over.

SUMMARY

The present invention is directed to a device that rocks back and forth when hit but will also topple over if hit too hard with a force, causing the device to swing at an angle too wide past its center of gravity. The present invention can be in three states: (1) a first stable state, in which the device sits in an upright position on a surface, (2) a second stable state, in which the device will rock back and forth and return to its upright position, and (3) a third stable state, in which the device rocks too far past its center of gravity, causing it to topple completely over. A target piece is attached to a first end of a stem, and a second end of the stem is attached to a base. The base is attached to the second end of the stem, and the stem is attached to the top piece. The base may have a ledge perimeter and a ledge, as well as a flat section on the bottom surface of the base and a curved section. The flat section is meant to touch the object/surface which the device is sitting on, and the curved section curves upwards from the bottom surface of the base. The device is meant to be hit with a force, allowing it to rock back and forth in a pendulum motion in a positive stability margin. It is the curved section of the base of the device that allows this back and forth motion. The device will topple over completely when it rocks at too far of an angle, at which point the device's center of gravity rocks into a negative stability margin.
The top piece of the device can be adapted to accommodate many different shapes. The top piece may be a hollow cavity for use as a drinking cup for wine, beer, soda, or the like. The hollow cavity may also be used to hold cards or paper notes, for example. The device may also have a shot glass holder top piece, in which a prior art shot glass with or without a prior art shot glass lid may be placed inside the shot glass holder top piece for use in a drinking game. Further, the device may have a target top piece in which said target top piece is used for target practice, such as a spherical shaped top piece, for use in shooting, archery, sling shot, BB gun, baseball, golf, or other like target game practice. The target top piece may also receive a loose object, such as a hat, that will lay on top of the device. Thus, during a target practice game, the user will hit the loose object with a force, intending to hit the object off of the device. The device may take the shape of a boxed block, in which the device comprises a boxed target piece and may have a boxed base, which may also be used for target games. Additionally, the device itself may take the shape of a figurine, such as a clown.
The device may also contain different shaped bases. In one version of the invention, the base is cylindrical. In another version of the invention, the based is box shaped, similar to a rectangular prism. In another version of the invention, the base is weight-holding, in which the weight-holding base is hollow and contains a weighted substance such as water or sand. The device may be adjusted such that a smaller or larger amount of force is necessary to cause the device to enter its third stable state. For example, in the weight-holding base embodiment, the base may be adjusted to hold more or less weight. If the base holds less weight, than the device will require less force to enter the third stable state. In other embodiments, the height of the device can be adjusted, requiring more or less force to make the device topple completely over into the third stable state.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view, showing a prior art rocking target game;

FIG. 2 is a side view, showing one embodiment of the present invention with an optional hollow top piece;

FIG. 3 is a cut-away view, showing the device of FIG. 2 filled with wine;

FIG. 4 is a bottom view, showing the base of the device of FIG. 2 ;

FIG. 5 is an exploded view of the base of the device shown in FIG. 2 ;

FIG. 6 is a side view of the device of FIG. 2 , showing the rocking motion of the device when hit;

FIG. 7A is a side view of the device of FIG. 2 in a first stable state, illustrating the device's center of gravity;

FIG. 7B is a side view of the device of FIG. 2 , illustrating the positive stability margin which allows the device to return to a first stable state;

FIG. 7C is a side view of the device of FIG. 2 in a second stable state, illustrating the center of gravity as the device rocks back and forth in the positive stability margin;

FIG. 7D is a side view of the device of FIG. 2 in a second stable state, illustrating the center of gravity as the device rocks back and forth into the negative stability margin;

FIG. 7E is a side view of the device of FIG. 2 , illustrating the device in a third stable state;

FIG. 7F is a side view of the device of FIG. 2 , illustrating the device transitioning from the second stable state to the third stable state;

FIG. 8 is cut-away view of the device of FIG. 2 , showing an optional shot glass-shaped cavity top piece;

FIG. 9 is a side view, showing a prior art shot glass and a prior art shot glass lid and the placement of the prior art shot glass into the device of FIG. 8 ;

FIG. 10 is a side view, showing another embodiment the present invention with an optional target top piece and an optional weight-holding base;

FIG. 11 is a cut-away view of the weight-holding base of the device shown in FIG. 10 ;

FIG. 12 is a side view, showing another embodiment of the present invention; and

FIG. 13 is an exploded view of the device showing in FIG. 12 , illustrating the base.

FIG. 14 is an elevation view, showing some of the parameters that are important to the performance of the present invention.

FIG. 15 is an elevation view, showing the embodiment of FIG. 14 when it is past the tipping point.

FIG. 16 is an elevation view, showing the embodiment of FIG. 14 when it is returning to an upright position.

FIG. 17 is a detailed elevation view, showing the embodiment of FIG. 14 in an upright position.

FIG. 18 is a detailed elevation view, showing the embodiment of FIG. 14 in a tipping configuration.

REFERENCE NUMERALS IN THE DRAWINGS

- 20 rocking target
- 22 inflatable punching bag (prior art)
- 24 weighted base (prior art)
- 26 hollow top piece
- 27 first end
- 28 curved stem
- 29 second end
- 30 base
- 31 top surface
- 32 liquid
- 35 bottom surface
- 36 curved section
- 38 flat section
- 40 ledge
- 41 ledge perimeter
- 42 top portion
- 44 bottom portion
- 46 shot glass holder top piece
- 48 shot glass holder
- 50 shot glass (prior art)
- 52 shot glass lid (prior art)
- 54 target top piece
- 56 straight stem
- 58 weight-holding base
- 59 cup
- 60 sand
- 64 boxed target piece
- 66 boxed base
- 68 surface
- 70 center of gravity
- 72 contact point
- 74 gravity vector
- 76 axis of symmetry
- 78 base plane
- 80 weight

DETAILED DESCRIPTION

In this Specification, claims, and accompanying drawings, reference is made to the particular features of the invention. It is to be understood that the disclosure of the invention includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or embodiment of the invention, or a particular claim, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects and embodiments of the invention, and the invention generally.
FIG. 2 illustrates one embodiment of the present invention. Rocking target 20 comprises hollow top piece 26, which is attached to first end 27 of curved stem 28, and base 30. Base 30 has a top surface 31 which is attached to second end 29 of curved stem 28. Hollow top piece 26 can be used to hold liquid such as water, beer, or wine, and it can also be used to hold paper or cards. Hollow top piece 26 is desirable to the present invention because it can be used for drinking games, wherein it can hold alcoholic drinks. Hollow top piece 26 can also hold paper or cards, which is desirable for use in card games or other games requiring use of paper, including games like “truth or dare.”
FIG. 3 shows a cut-away view of the present invention. Hollow top piece 26 of rocking target 20 is filled with liquid 32 (wine, as one example). This is desirable to the invention for use at parties or as a drinking game. Though the figure shows hollow top piece 26 filled with wine, the reader will appreciate that hollow top piece 26 could be filled with any liquid, including other alcoholic drinks, water, and juice. The ability of rocking target 20 to hold a liquid is advantageous in that the user may enjoy the mere novelty of the ability of rocking target 20 to sway back and forth and return to a first stable state (upright position) when hit with a light force.
FIG. 4 is a bottom view of base 30, illustrating flat section 38, which is the surface 68 that rocking target 20 will lay flat on when in its first stable state. Flat section 38 is necessary such that rocking target 20 may rest on surface 68 (not shown) when in its upright position. When rocking target 20 is hit with a force, it will teeter back and forth, much like the motion of a swinging pendulum, in a second stable state. So long as rocking target's 20 center of gravity remains within the positive stability margin, it will return from the second stable state to a first stable state, with rocking target 20 sitting upright, lying flat on flat section 38. Flat section 38 curves upward, creating curved section 36. Curved section 36 is attached to ledge 40, which creates ledge perimeter 41 along the edges of base 30. While this figure depicts ledge 40 and ledge perimeter 41, the reader will appreciate that the present invention does not require the presence of ledge 40 or ledge perimeter 41 in all embodiments.
FIG. 5 shows a side elevation view of base 30. Top portion 42 and bottom portion 44 will often be made as a single unified piece—such as by injection molding. Flat section 38 is the portion of the base that customarily rests on a flat surface. Curved section 36 surrounds flat section 38. Ledge 40 surrounds curved section 36. Ledge perimeter 41 is the outermost edge of the ledge. In this example, curved stem 28 extends upward from top surface 31. Again, the reader will appreciate that ledge 40 and ledge perimeter 41 are optional.
FIG. 6 shows the rocking motion of rocking target 20 when hit with any outside force. Rocking target 20 will swing back and forth like a pendulum—until rocking target 20 eventually either returns to the first stable state, settles into a second stable state (explained subsequently), or topples over into a third stable state. The version shown actually has three stable states and a plurality of metastable transition states. These various states create interesting motions and add to the excitement of the target games.
FIGS. 7A-7F illustrate these various states. The reader will appreciate that, while ledge perimeter 41 is shown in these figures as a reference point to gravity vector 74, ledge perimeter 41 is not required in the present invention and rocking target 20 can have three stable states regardless of the presence of ledge 40 and ledge perimeter 41. FIG. 7A shows rocking target 20 in its first stable state. Flat section 38 of base 30 is resting on a surface 68 (such as a table top). Center of gravity 70 of the rocking target as a whole lies directly above flat section 38. The result is a stable state. In the context of this application this will be referred to as the “first stable state.”
FIG. 7B shows the same rocking target after it has been struck and tipped to one side. FIG. 7B shows the farthest tipping motion obtained. The contact between the tipping target and surface 68 is made at contact point 72. Gravity vector 74 passes vertically downward from center of gravity 79. The reader will observe how gravity vector 74 passes to the left of contact point 72. This means that the target will tip back to the left and eventually reach the first stable state again.
FIG. 7C shows the target after an even larger upsetting force has been applied. Gravity vector 72 now lies to the right of contact point 72, meaning that the target will now continue to tip further toward the right. However, the reader will note that gravity vector 74 lies to the left of ledge perimeter 41. The target will tip further to the right, but the tipping will be arrested (unless the dynamic rate of tipping is very high) when ledge perimeter 41 makes contact with surface 68. The result is that the target will again become stable—but this time in a leaning state (shown in FIG. 7F). This leaning state will be referred to as the “second stable state.” The second stable state provides interesting dynamics because the target will roll around on ledge perimeter 41. The rolling will continue for some time before the target comes to a complete stop.
FIG. 7D shows the tipping target after an even greater disturbing force has been applied. In this case the target has tipped sufficiently for the point of contact to become ledge perimeter 41. Gravity vector 74 now lies to the right of ledge perimeter 41. The target will therefore continue to tip—all the way onto its side.
The fully tipped state is shown in FIG. 7E. This fully tipped configuration is referred to as the “third stable state.” Here, device 20 was hit too hard by an upsetting force, causing the device to completely topple over. Base 30 is no longer lying on flat section 38. Rather, the entire device 20 sits horizontally sideways on a surface 68.
FIG. 7F shows device 20 in the second stable state. Device 20 has rocked passed curved section 36 to the left onto ledge perimeter 41. From here, device 20 will roll around on the ledge until the rotational motion eventually decays.
FIG. 8 shows the present invention with an optional shot glass holder top piece 46. Rocking target 20 still comprises a base 30 and a curved stem 28 but shot glass holder top piece 46 has replaced hollow top piece 26. Shot glass holder top piece 46 comprises a hollow cavity in the shape of a shot glass, such that a user may place a prior art shot glass 50 into the cavity. Shot glass holder top piece 46 is made so that a user may easily place and retrieve a prior art shot glass 50 from the shot glass-shaped hollow cavity. As shown, shot glass holder top piece 46 is made to fit a conventional rounded shot glass, but the reader will appreciate that optional shot glass holder top piece 46 may be shaped to fit any size or shape prior art shot glass 50.
FIG. 9 shows how a user would use rocking target 20 with shot glass holder top piece 46. The user may optionally place a prior art shot glass lid 52 on top of prior art shot glass 50 to prevent spillage in the event rocking target 20 topples over into its second or third stable states. The user would then place prior art shot glass 50 into shot glass holder top piece 46.
FIG. 10 illustrates another embodiment of the present invention. This embodiment is desirable for users that prefer to use rocking target 20 as a target practice game. This is because rocking target 20 comprises a target top piece attached to a straight stem 56. As shown, straight stem 56 is attached to the top surface 31 of a weight-holding base 58, but the reader will appreciate that rocking target 20 may alternatively comprise base 30. Target top piece 54 may be spherical (shown), or any other shape designed to be hit with a force, such as a conventional ovular target for practice, and may be solid or hollow on the inside. In a game using rocking target 20, the users will preferably aim to hit target top piece 54. When target top piece 54 is hit, rocking target 20 will move from the first stable state and begin to swing back and forth in a second stable state. If target top piece 54 is hit too hard with a force, the entire rocking target 20 will topple completely over to a third stable state.
FIG. 11 is a cut-away illustration of weight-holding base 58. Weight-holding base 58 has a cup 59, which has a hollow inside. The reader will appreciate that cup 59 of weight-holding base 58 can take any shape. Top portion 42 is shown below cup 59. In this embodiment, top portion 42 is hollow inside. Cup 59 is filled with sand 60 in the figure, but any other weight-bearing substance, such as a liquid, could also be used. Top portion 42 is attached to bottom portion 44, which comprises curved section 36 and a flat section 38. Device 20 (not shown) will rock on curved section 36 if hit with a force (second stable state). Flat section 38 makes contact with the surface 68 (not shown) that device 20 lies flat on in its upright position (first stable state). The reader will appreciate that top portion 42 bottom portion 44 can be any shape, so long as the base has a ledge and a curved section. Rocking target 20 will teeter back and forth in a second stable state when hit with a force. However, once rocking target 20 is hit too hard, it will enter into the negative stability margin (not shown) and, like other embodiments of the invention, will topple completely over into a third stable state.
FIG. 12 shows a perspective view of a third embodiment of the present invention. Rocking target 20 comprises an elongated boxed target piece 64 that is attached to a boxed base 66. Boxed target piece 64 has a length and takes the shape of an elongated cube or rectangular prism, with a height greater in length than its width. In this embodiment, rocking target 20 may be hit at any point along boxed top piece 64, and such force will cause rocking target 20 to teeter back and forth in a second stable state along boxed base 66. Though this embodiment is shown with the presence of boxed base 66, the reader will appreciate that boxed base 66 is not required in this embodiment.
FIG. 13 shows a detailed view of boxed base 66 of FIG. 12 . Boxed base 66 is like alternative bases described in other embodiments of the invention in that it comprises curved section 36 and a flat section 38 on bottom surface 35 of boxed base 66. Rocking target 20 comprises four ledges 40, which are at the end of boxed top piece 64 that is attached to boxed base 66. Rocking target 20 lies upright on flat section 38. When hit with a force, rocking target 20 enters a second stable state and rocks back and forth along curved section 36. So long as rocking target 20 does not enter into the negative stability margin, rocking target 20 will not topple over from a second stable state into a third stable state. Rather, rocking target 20 will return from a second stable state to a first stable state. Again, the reader will appreciate that boxed base 66 is not required in this embodiment and is merely shown as an option.
The “force” used to hit rocking target 20 may be anything that would cause rocking target 20 to move from its first stable state, including for example a hand or foot, a ball, a bat, a projectile, or a golf club. Rocking target 20 may be made of any durable material, including wood, plastic, or the like. Preferably, hollow top piece 26 and shot glass holder top piece 46 will be made out of a liquid-resistant material. The top piece, stem, and base in any of the embodiments may be attached with any adhesive material, including glue, wood glue, or may be manufactured as one piece. Alternatively, the top piece, stem, and base in any embodiment may be magnetically attached to each other, such that when a user hits rocking target 20 with a force, the force overcomes the magnetic attraction and causes rocking target 20 to come apart. Any embodiments of the present invention may also have a meter placed inside of it, such that the force or angle can be recorded when a user hits rocking target 20.
The previously described embodiments of the present invention have many advantages. The invention allows user to play drinking or target games, wherein the object of the game may be either to cause rocking target 20 to topple over into a third stable state or cause rocking target 20 to swing back and forth in a second stable state without toppling completely over. The present invention may be used to hold liquid, such as when users want to play a drinking game or can include a target top piece for users that want to use rocking target 20 for target practice. Finally, rocking target 20 has different options for base pieces, wherein the base may incorporate a curved section and a ledge or a weight-holding base 58.
FIGS. 7A-7E serve to illustrate the basic operative principles of the three stable states the invention can assume and the transitions between these states. The reader's understanding may well benefit, however, from an explanation of how to optimize the dimensions of the inventive target so that it will operate in the desired fashion. FIGS. 14-18 illustrate the optimization process for a representative embodiment.
FIG. 14 shows the inventive target in the second stable state. This is the state that is the most difficult to optimize and therefore the one that will drive the selection of the parameters. Some basic terms will be defined in order to aid the reader's understanding. A coordinate system is helpful in defining the parameters. Base plane 78 is a plane running through flat section 38 (on the very bottom of base 30). Axis of 76 is the central axis of the radially symmetric inventive target. This axis is perpendicular to base plane 78.
The empty rocking target 20 has a center of gravity, C_GE. Of course, the overall center of gravity will shift when hollow top piece 26 is filled with liquid. Liquid 32 has a center of gravity, C_GL. Once the liquid is added, the combination of the empty rocking target and the added liquid will have a combined center of gravity (full), C_GF. The gravity vector 74 then acts downward from the position of the combined center of gravity (full)—as shown.
In order to achieve the desired stable second state, two conditions must be met:

- (1) The rocking target must have two contact points. For the second stable state these are point A (along ledge perimeter 41) and point B_Calong curved section 36; and
- (2) The location of C_GFmust be such that gravity vector 74 passes downward between the location of point A and the point B_C.

The location of the contact point along curved section 36 will vary as the target tips away from the vertical (the first stable state). This contact point is generally referred to as point B. The state shown in FIG. 14 is a critical state representing the second stable state. The point B at this instant is a “critical” point B and thus is referred to as B_C. It is important for point A and point B_Cto be separated along surface 68, for reasons that will be made apparent.
The center of gravity of the liquid is depicted with a dashed alternate location. As the rocking target tips the liquid surface will tend to remain level and the liquid's center of gravity will shift slightly to the left of axis of symmetry 76 (“left” referring to the orientation shown in FIG. 14 ). This shift will cause the overall center of gravity (C_GF) to move up stem 28 and slightly to the left of axis of symmetry 76. The shift is not large, however, and so long as a reasonably large separation is provided between points A and B_Cthe shift in the center of gravity of the liquid can be safely ignored.
The liquid placed within hollow top piece 26 may be water, wine, beer, soft drinks, etc. All of these liquids have a specific gravity that is very close to that of pure water (1.0). One may therefore safely assume a center of gravity of 1.0 for the liquid. One may also assume a volume of liquid that is to be added. A good estimate is 40-80 percent of the volume inside hollow top piece 26. Again, provided that a reasonably large separation is provided between points A and B_Cthe variation in the volume of liquid added can be safely ignored.
The rocking target itself is preferably made from a polymer—such as by injection molding. It is desirable to provide a tough polymer that can withstand many cycles (recalling that the rocking target will be struck by thrown objects). ABS (acrylonitrile butadiene styrene) is a good choice for the rocking target. ABS has a specific gravity of about 1.06 (The specific gravity varies for different formulations).
The dimensions of the rocking target (particularly the thickness and radii of the base section 30) will determine the distance L₁from base plane 78 to C_GE. The length of the stem 28 and the size of hollow top piece 26 will determine the distance L₂from the base plane to C_GL. The relative density of the material used for the rocking target and the liquid will then determine how much the overall center of gravity shifts upward from the position of C_GEto the position of C_GF. The result will be the distance L₃from base plane 78. The distance L₃is very important, because it determines the point of origin for gravity vector 74.
The state shown in FIG. 14 is the critical angle of tipping needed to remain in the second stable state. The angle between the vertical and axis of symmetry is the critical angle, α_C. Point A is fixed along ledge perimeter 41. Point B is a moving point along curved section 36 as the axis of symmetry moves from vertical toward the critical angle. In the particular state shown point B is referenced as B_C—the critical point on curved surface 36 where ledge 41 comes into contact with surface 68. The position of points A and B_Cdetermine the critical angle (They are fixed points in the geometry of the rocking target and when both are in contact with surface 68 the angle between the axis of symmetry 76 and the vertical is fixed).
Point A is located a distance (radius) R₂from axis of symmetry 76. Point B_Cis located a distance (radius) R₁from axis of symmetry 76. The reader will at this point appreciate that—for a defined critical angle in which the second stable state will exist—the designer must select R₁, R₂, and L₃so that the gravity vector 74 passes downward between points A and B_C. Otherwise the state shown in FIG. 14 will not be stable.
The fact that the material used for the rocking target (such as ABS) and the liquid placed in hollow top piece 26 have a similar density limits the choices of geometry. In some embodiments it will be preferable to add a ballast to the base—such as weight 80—in order to provide more variation in the geometry selected. Zinc, for example, has a specific gravity of about 7. A small volume of zinc added as weight 80 will move the location of C_GFsignificantly down stem 28 and allow the designer to alter the geometry so that a more pleasing aesthetic is achieved.
FIGS. 15 and 16 illustrate excursions that are possible from the second stable state depicted in FIG. 14 . In FIG. 15 , the same rocking target has been pushed to a greater angle from the vertical until gravity vector 74 passes outside of point A (Point A lies between the gravity vector and axis of symmetry 76. From this position the rocking target will tip over and rest on its side (the third stable state).
In FIG. 16 , the same rocking target has been pushed toward the vertical. Gravity vector 74 passes inside of point B (The gravity vector passes between point B and axis of symmetry 76). From this position the rocking target will continue to rotate clockwise until it rests upright with flat section 38 resting on surface 68.
FIGS. 17 and 18 show additional details that enhance the operation of the rocking target. In FIG. 17 the rocking target is vertical and stable. Curved section 36 is preferably included adjacent to flat section 38 (the bottom of the base). As the target begins to tip, the point of contact with surface 68 transitions from point C to a moving point along curved section 36 (designated as arbitrary point B_n). The tipping process is shown in FIG. 18 . The reader will note how the surface contact now exists at point B_n. The inclusion of a curved section 36 makes the transition from vertical to tipping more smooth. In addition, the transition to the curved surface causes the entire target to lift more while tipping (as compared to a simple tipping about point C). This additional lifting means that more energy must be applied to overcome the natural tendency to remain in the first stable state (upright). Stability in the first stable state is thereby enhanced.
The process for optimizing a rocking target according to the present invention may then be summarized as follows:

- (1) Define a volume for hollow top piece 26 and thereafter define an assumed volume for the liquid to be added. This provides a mass for the liquid (based on the assumption of a specific gravity of 1.0);
- (2) Select a material to be used for the rocking target itself. This will provide a density that is used in the center of gravity calculations;
- (3) Define the distance L₂primarily by selecting a length for stem 28 (though also to a lesser extent by selecting the geometry of hollow top piece 26);
- (4) Define the geometry for base 30. This geometry will determine the position of point A and point B_C. This, in turn will define the critical angle α_C;
- (5) Determine the distance L₃using a center of gravity calculation;
- (6) Using the distance L₃and the critical angle α_C, define the position of the gravity vector 74 (with the rocking target set to the critical angle);
- (7) If the gravity vector passes between points A and B_Cthen a workable set of parameters has been found;
- (8) If the gravity vector passes outside of point A, then alter the parameters to move the passage of the gravity vector toward axis of symmetry 76 (such as, for example, reducing the stem length to reduce the length L₂or adding thickness to base 30 to increase the mass of the base and reduce the length L₁. Another option is to add a weight 80 to reduce the length L₁); and
- (9) If the gravity vector passes inside of point B_C, then alter the parameters to move the passage of the gravity vector away from axis of symmetry 76 (such as, for example, increasing the stem length to increase the length L₂or reducing the thickness of base 30 to decrease the mass of the base and increase the length L₁).

The order of the steps provided is not critical, so long as they eventually arrive at a set of workable parameters. This, once could start with a fixed base geometry and then simply vary the length of the stem and the volume of hollow top piece 26 to reach a workable solution.
An example of working values for the parameters may be helpful. This example refers to the geometry of FIG. 14 . The following values for the parameters produced the desired second stable state:

- R₁=2.7 cm
- R₂=3.5 cm
- α_C=31.7 degrees
- L₃=5.3 cm

Numerous other sets of working values for the parameters can be obtained. The particular embodiments described are preferred due to their advantages over the prior art but are not required in all versions of the invention. Importantly, the invention does not require that all the advantageous features described herein be incorporated into every embodiment of the invention.
The preceding description contains significant detail regarding the novel aspects of the present invention. It should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. As an example, rocking target 20 may contain a top piece that is any shape, including a target shape, a piece with a hollow cavity, or the shape of a rectangular prism.

Claims

Having described my invention, I claim:

1. A method for playing a game using a rocking target, comprising:

(a) providing a base for said rocking target, including,

(i) a flat section lying in a base plane,

(ii) an axis of symmetry perpendicular to said base plane,

(iii) a point A on said base separated from said axis of symmetry by a distance R₂,

(iv) a point B_Con said base separated from said axis of symmetry by a distance R₁,

(v) said points A and B_Cin combination defining a critical angle for said rocking target;

(b) providing a stem for said rocking target, wherein said stem extends upward form said base along said axis of symmetry;

(c) providing a hollow top piece for said rocking target, wherein said hollow top piece rests on top of said stem;

(d) defining a volume of liquid to be placed in said hollow top piece of said rocking target;

(e) defining a full center of gravity for said rocking target representing a combination of said rocking target and said defined volume of liquid, said full center of gravity being offset a distance L₃from said base plane;

setting values for R₁and R₂such that a gravity vector passing downward from said full center of gravity, when said rocking target is at said critical angle, passes between said points A and B_C;

(g) striking said rocking target with an upsetting force, thereby tilting said rocking target into a stable state wherein said gravity vector passes downward through said points A and B_C.

2. The method for playing a game using a rocking target as recited in claim 1, comprising:

(a) wherein said defined volume of liquid has a liquid center of gravity offset a distance L₂from said base plane; and

(b) adjusting said distance L₂by adjusting a length of said stem and said defined volume in order to obtain a desired value for said distance L₃.

3. The method for playing a game using a rocking target as recited in claim 1, comprising:

(a) wherein said rocking target has an empty center of gravity offset a distance L₁from said base plane; and

(b) adjusting said distance L₁by adjusting a geometric configuration of said base in order to obtain a desired value for said distance L₃.

4. The method for plying a game using a rocking target as recited in claim 2, comprising:

5. The method for playing a game using a rocking target as recited in claim 1, comprising:

(b) adjusting said distance L₁by adding a weight to said base in order to obtain a desired value for said distance L₃.

6. The method for playing a game using a rocking target as recited in claim 2, comprising:

7. The method for playing a game using a rocking target as recited in claim 3, comprising:

8. The method for playing a game using a rocking target as recited in claim 4, comprising: