Golf disc

Abstract

The present invention relates to a golf disc having enhanced flight stability, durability, and environmental sustainability. In particular, the invention relates to a golf disc comprising an upper flight plate surface (2), a lower flight plate surface (3) and a rim (4) connecting the upper flight plate surface (2) and the lower flight plate surface (3) as a contiguous piece, - the lower flight plate surface (3) comprises a central opening (5) defined by an upper inner rim edge (7) and a lower inner rim edge (6), - the rim (4) comprises an upper rim surface (9), a lower rim surface (10) and an outer rim edge (8) defining the outer diameter (D1) of the golf disc, wherein the upper rim surface (9) and the lower rim surface (10) both have a convexly curved profile.

Description

[0001] Golf disc

[0002] The present invention relates to a golf disc having enhanced flight stability, durability, and environmental sustainability.

[0003] BACKGROUND OF THE INVENTION

[0004] Disc golf is a popular sport that combines elements from traditional golf and from frisbee. Players throw a special golf disc from a starting area, called the tee, aiming to hit a target basket in as few throws as possible. Disc golf courses typically consist of 9 or 18 holes, and players must navigate through various terrains and obstacles to hit the target basket on each hole. Disc golf requires technique, precision, and strategy, where players must master various throwing types and disc choices to achieve optimal results.

[0005] Golf discs are generally characterized as understable, stable, or overstable, based on their in-flight behavior. Players choose a disc based on personal preferences and the specific requirements of each hole on the course. The stability of a disc affects its flight path and performance in various conditions, including wind. Traditional golf discs on the market have an edge with a pressure difference between the top and bottom sides, which affects the stability of the gyroscopic effect and creates undesirable flight patterns, especially in varying wind conditions.

[0006] US4568297A discloses a one-piece flying disc formed of a flexible plastic with an annular rim and a central section joined together by an annular shoulder. The rim has a lower edge defining a lower plane of the disc and the central section has an upper zone defining an upper plane of the disc. The rim has a triangular cross-section comprising three corners: a lower rounded corner forming a lower edge, an outer rounded corner, and an upper corner merging with the shoulder. The outer corner of the rim is located between the upper and lower planes, and the shoulder decreases in thickness from the rim to the central section.

[0007] GB2410905A discloses a flying disc comprising a thin central plate (20) with an outer annular rim (30) having an overall triangular profile formed with convex curves. The annular rim has an outer rounded corner (62) and a lower rounded corner (63) joined by a convex curve (71) and the inside rim (80) is substantially vertical. The curve joining the lowest part of the rim to the inside rim may be formed so that its radius of curvature decreases towards the inside rim. A convex curve (70) joins the upper corner (61) to outer rounded corner (62).

[0008] US 2023 / 0090692 Al relates to an apparatus comprising a disc having a bottom flight plate structure (11) and an upstanding edge (12), such as a curved saucer-like contour edge, included with and circumscribing the bottom structure forming a recess. The apparatus also includes an inner central structure underneath the bottom structure at a central portion of the disc. The apparatus or at least part of the apparatus can be plastic or foam and can include rubber components that make it easier to grip. The apparatus can include a thumb ring underneath the bottom structure and within the inner central structure.

[0009] Both the above-mentioned documents optimize the flying discs as a wing having a specific airfoil profile, and none of the documents discuss the gyroscopic effect of the discs during flying. The present invention provides a new perspective in the design and understanding of golf disc flight dynamics as the gyroscopic effect is included in the design.

[0010] SUMMARY OF THE INVENTION

[0011] The present invention provides a novel golf disc design featuring an elliptical edge that connects the disc's top side to the bottom side in a continuous piece. The golf disc has uniform pressure on both the top and bottom sides of the edge during the throw with rotation. This design ensures minimal impact on the gyroscopic effect and provides improved stability and control during flight, both in headwind and tailwind conditions.

[0012] The invention enables the production of a disc with a plastic density below 1, which can float on water. The elliptical shape allows for the distribution of more weight towards the edge, making it possible to create a golf disc with a narrower edge than 26 mm while maintaining the maximum weight. More weight near the edge increases the centrifugal force during rotation, resulting in longer and more stable throws, regardless of wind conditions.

[0013] Thus, one aspect if the invention relates to a golf disc comprising an upper flight plate surface (2), a lower flight plate surface (3) and a rim (4) connecting the upper flight plate surface (2) and the lower flight plate surface (3) as a contiguous piece,

[0014] - the lower flight plate surface (3) comprises a central opening (5) defined by an upper inner rim edge (7) and a lower inner rim edge (6),

[0015] - the rim (4) comprises an upper rim surface (9), a lower rim surface (10) and an outer rim edge (8) defining the outer diameter (DI) of the golf disc, wherein the upper rim surface (9) and the lower rim surface (10) both have a convexly curved profile, and the profile of the rim (4) is elliptic i.e. the rim (4) has a profile corresponding to the half of an ellipse having a major axis with length 2W and a minor axis with length (H3+H4).

[0016] That the profile is convexly curved means that the profile of a cross-sectional cut is curved outward in contrast to a profile being concavely curved which would curved inward and which is known from the prior art.

[0017] According to an embodiment of the invention, the profile of the rim (4) may have a tangent t in the point defined by the outer rim edge (8).

[0018] According to an embodiment of the invention, the profile of the upper rim surface (9) and the profile of the lower rim surface (10) may mirror each other around a symmetry line through a point defined by the outer rim edge (8).

[0019] According to an embodiment of the invention, the upper flight plate surface (2) may be flat i.e. may have a profile corresponding to a straight line, from a profile point defined by the upper inner rim (7) or for a central area within the upper inner rim edge (7).

[0020] According to an embodiment of the invention, the golf disc (19 may be constituted of a material having a density below 999 kg / m3, preferably the golf disc is constituted of a polymer such as thermoplastic polyurethane (TPU) or polyethylene (PE), or polypropylene (PP), or ethylene-vinyl acetate (EVA), or polyvinyl chloride (PVC).

[0021] According to an embodiment of the invention, the width W of the rim (4) may be < 30 mm, or < 28 mm, or < 26 mm, or < 25 mm.

[0022] According to an embodiment of the invention, at least 90% of the total weight of the golf disc (1) may be distributed in the rim (4) to increase the centrifugal force during rotation.

[0023] According to an embodiment of the invention, the angle of the symmetry line s of the rim (4) relative to the upper flight surface (2) may be between -10 degrees and +10 degrees providing understable, stable, or overstable flight patterns.

[0024] According to an embodiment of the invention, the golf disc (1) fulfills the standards of the Professional Disc Golf Association (PDGA) (rev. 12.24.2024).

[0025] According to an embodiment of the invention, the elliptical edge shape (20) may be connected to a circular section (25) that links to the inner edge (30), which may be connected to another circular section (35) that ultimately connects to the bottom surface (40). The purpose of the circular section (25) is to further stabilize the disc with a radius ranging between 0.25 mm and 5 mm, and the purpose of the circular section (35) is to strengthen the construction and prevent a notch effect at the junction with the bottom surface (40), with a radius ranging between 0.25 mm and 5 mm.

[0026] According to an embodiment of the invention, the diameter of the golf disc (1) may be less than 21 cm, enabling a smaller and more compact disc suitable for specific throws, for children, or other game variations, regardless of whether it is PDGA-approved.

[0027] According to an embodiment of the invention, the weight of the golf disc (1) may be over 8.3 g per centimeter in diameter, providing a heavier and more stable golf disc that may be suitable for specific throws, players with greater power, or other game variations, regardless of whether it is PDGA-approved.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 illustrates a prior art golf disc with normally applied dimensions.

[0030] Figures 2A and 2B shows two perspective views of an embodiment of a golf disc according to the invention.

[0031] Figure 3 shows a cross-sectional view of the first embodiment.

[0032] Figure 4 shows a cross-sectional view of a second embodiment of a golf disc according to the invention. Figure 5 shows a cross-sectional view of a third embodiment of a golf disc according to the invention.

[0033] Figure 6 shows a cross-sectional view of a fourth embodiment of a golf disc according to the invention.

[0034] Figure 7 shows an image of a wind tunnel simulation comparing a golf disc according to the invention with an existing disc shape.

[0035] Figure 8 shows an image of a wind tunnel simulation of a golf disc according to the invention, where the edge is angled at different degrees relative to the top surface.

[0036] Definitions:

[0037] In general - if this expression is used to describe a feature, the feature may be used with all embodiments of the invention even though the feature is mentioned in the detailed part of the description or in the context of a specific embodiment.

[0038] DETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention relates to a golf disc which during playing provides precise and stable flight under varying wind conditions and improves the disc's trajectory and gliding ability. The invention optimizes the golf disc's stability, control, and precision under different wind conditions and even pressure distribution.

[0040] Figure 1 shows a cut-through view of a prior art golf disc and is used to illustrate how a traditional golf disc is constructed. The dimensions defined for the prior art golf disc of fig. 1 also applies for embodiments of the golf disc according to the invention. In general, a golf disc 1 whether this is provided according to prior art or according to the invention complies with PDGA (Professional Disc Golf Association) regulations.

[0041] In general, a golf disc 1 comprises a circular flight plate having an outer diameter DI, and the flight plate is normally unbroken by perforations, the flight plate has an upper flight plate surface 2 and a lower flight plate surface 3. The upper flight plate surface 2 is normally relatively smooth and comprises a central flat part with diameter D4. The lower flight plate surface 3 comprises a rim 4 surrounding a central opening 5 having a diameter D2, the rim 4 has a lower inner rim edge 6, an upper inner rim edge 7 and an outer rim edge 8. The maximum height of the flight plate H2 is normally constituted by the vertical distance between the lower inner rim edge 6 and the top surface of the upper flight plate surface 2. The width W of the rim 4 is (D1-D2) / 2. The outer rim edge 8 defines a split between an upper height H3 of the rim 4 and a lower height H4 of the rim, in the prior art embodiment of a golf disc shown in fig. 1, the upper height H3 of the rim 4 is significantly larger than the lower height H4 of the rim 4. Also, the lower surface of the rim 4 is slightly convex i.e. curving inward while the upper surface of the rim 4 is slightly concave i.e. curving outward.

[0042] The height Hl of the rim is defined by the distance between the lower inner rim edge 6 and the upper inner rim edge 7. In the description of the golf disc 1 “upper” and “lower” refers to the position of the golf disc during flight.

[0043] Normally, the outer diameter DI is between 21 cm and 30 cm, or between 21 cm and 25 cm.

[0044] In general, a preferred material for the golf disc 1 is thermoplastic polyurethane (TPU) with a density between 0.9 and 0.99 which allows the golf disc to float on water. However, other plastic and rubber materials, such as polyethylene (PE), polypropylene (PP), ethylene-vinyl acetate (EVA), and polyvinyl chloride (PVC), are also suitable.

[0045] Figures 2A and 2B show two perspective views of an embodiment of a golf disc according to the invention, fig. 2A shows the upper flight plate surface 2 and fig. 2B shows the lower flight plate surface 3 and the central opening 5 in the lower flight plate surface 3.

[0046] Figure 3 shows a cross-sectional view of a first embodiment of a golf disc according to the invention. This embodiment comprises an upper flight plate surface 2 connected to the upper surface 9 of the rim 4, the upper surface 9 of the rim 4 is connected to a lower surface 10 of the rim 4 via and via the outer rim edge 8 which defines the outer periphery of the golf disc 1 and the outer diameter DI of the golf disc.

[0047] A curve along the upper and lower surfaces 9, 10 of the rim 4 through the outer rim edge 8 defining the profile as shown in fig. 3 is rounded, i.e. the curve has a tangent t in the point defining the outer rim edge 8.

[0048] Also, both the profile line defining the upper surface 9 of the rim 4 and the profile line defining the lower surface 10 of the rim 4 are convex, i.e. consequently neither the profile line defining the upper surface 9 nor the profile line defining the lower surface 10 are straight lines partially or completely, nor are the profile lines concave partially or completely.

[0049] In general, the profile of the upper rim surface 9 may be convex in its full length, i.e. from the point defining the outer rim edge 8 to the point where the upper rim surface 9 meets or joins an upper flight plate surface 2.

[0050] In general, the upper flight plate surface 2 (D2) may be flat which means that the upper flight plate surface 2 in the shown profile is described by a straight line. Alternatively, the upper flight plate surface 2 according to the invention may be slightly curved upwards e.g. as shown in fig. 1 according to which embodiment the upper flight plate surface 2 has a convexly curved side-section (D2-D4) and a flat central section (D4). According to the invention, the diameter of a flat central section of the upper flight plate surface 2 may be between 0 and D2, e.g. at least 0.9 times D2, or at least 0.8 times D2, or at least 0.5 times D2.

[0051] In general, the profile of the lower rim surface 10 may be convex in its full length, i.e. from the point defining the outer rim edge 8 to the point where the lower rim surface 9 meets or joins the lower inner rim edge 6.

[0052] According to a preferred embodiment, the profile lines of the upper and lower rim surfaces 9, 10 may be symmetric around a line s reaching from the outer rim edge 8 to an inner surface of the central opening which may be a line reaching between the lower inner rim edge 6 and the upper inner rim edge 7. The line s is perpendicular to the tangent t through the point of the profile defining the outer rime edge 8.

[0053] The part of the profile comprising the upper rim surface 9, the outer rim edge 8 and the lower rim surface 10 may form an elliptically shaped rim 4. The elliptically shaped rim 4 is connected to the central opening 5 and the lower flight surface 3 at the lower inner rim edge 6. In general, the width W of the rim 4 corresponds to around half of the major axis of an ellipse, and the height H3+H4 corresponds to the minor axis of the ellipse shaping the rim profile.

[0054] The thickness H5 of the central portion above the central opening 5, between upper flight plate surface 2 and lower flight plate surface 3, may range between 0.5 mm and 4.5 mm, while the overall height H3 + H4 of the golf disc between upper flight surface 2 and lower inner rim edge 6 may vary between 11.5 mm and 25 mm. The width W of the rim 4 may range from 12 mm to 26 mm.

[0055] When the golf disc comprises a rim 4 comprising convex upper and lower surfaces 9, 10 the pressure distribution is improved, and by making the upper rim surface 9 and the lower rim surface 10 symmetrical around the line s the pressure distribution is even further improved. Further, providing the upper and lower surfaces of the rim 9, 10 with an elliptical shape optimizes the distribution of pressure around the edge and thereby optimizes the flight of the golf disc.

[0056] The edges formed at the lower inner rim edge 6 and the upper inner rim edge 7 may be sharp as shown in fig. 3, i.e. the two surfaces forming either the inner rim edge 6 or the upper rim edge 7 forms an angle e.g. an 90 degrees angle in a point without a tangent.

[0057] Figure 4 shows a cross-sectional view of a second embodiment of the invention comprising the same elements referred to by the same reference numbers as the first embodiment shown in fig. 3. This second embodiment differs from the first embodiment in that the circular line defining the lower inner rim edge 6 in the shown profile is defined by a curved line i.e. a line having a tangent. Also, the circular line defining the upper inner rim edge 7 in the shown profile is defined by a curved line i.e. a line having a tangent. According to this embodiment the symmetry line s for the upper and lower rim surfaces 9 and 10 is perpendicular both the tangent t through the outer rim edge 8.

[0058] The purpose of providing the lower inner rim 6 with a curved profile instead of an angular corner as shown in fig. 2, is to further stabilize the golf disc, the lower inner rim 6 may curve over a radius ranging between 0.25 mm and 5 mm.

[0059] The purpose of providing the upper inner rim 7 with a curved profile instead of an angular corner as shown in fig. 2, is to strengthen the construction and prevent a notch effect at the junction of the central opening 5, the upper inner rim 7 may curve over a radius ranging between 0.25 mm and 5 mm. Figure 5 shows a cross-sectional view of a third embodiment of the invention comprising the same elements referred to by the same reference numbers as the first and second embodiments shown in fig. 3 and 4.

[0060] According to the third embodiment, the symmetry line s of the rim surfaces 9 and 10 is angled upward relative to the upper flight plate surface 2, the symmetry line s angled at around 20 degrees relative to the upper flight surface 2. The symmetry line s is still perpendicular to the tangent t through the point formed by the outer rim edge 8.

[0061] The angling of the symmetry line s for the upper and lower rim surfaces 9, 10 results in increased air pressure on the lower rim surface 10 of the rim 4 when the golf disc is thrown, thereby making the golf disc overstable.

[0062] Figure 6 shows a cross-sectional view of a fourth embodiment of the invention comprising the same elements referred to by the same reference numbers as the first, second and third embodiments shown in fig. 3, 4 and 5.

[0063] According to the fourth embodiment, the symmetry line s of the upper and lower rim surfaces 9, 10 is angled downward relative to the upper flight plate surface 2. This feature results in larger air pressure at the upper rim surface 9 when the golf disc is thrown, making the golf disc understable.

[0064] Figure 7 shows an image of a wind tunnel simulation comparing a golf disc A according to the first embodiment of the invention with a prior art golf disc B.

[0065] Fig. 7 shows a line defining a plane extending along the outer rim edge 8 of each of the golf discs A which is constructed according to the invention, and B which is constructed to prior art as shown in fig. 1. The images obtained in the wind tunnel simulations demonstrate that the pressure or turbulence on the top side and bottom side of the edge of golf disc A, along the line defined by the outer rim edge 8, is very similar, indicating an even pressure distribution during rotation.

[0066] In contrast, the prior art golf disc B, along the line defined by the outer rim edge 8, shows a significant difference in pressure on the top side and bottom side of the edge in particular close the front lower inner rim edge 6.

[0067] The visual evidence provided by fig. 7 illustrates the improved properties of the golf disc A in terms of pressure distribution and the resulting enhanced flight characteristics.

[0068] Figure 8 show images of a wind tunnel simulation of the second, third and fourth embodiments of golf discs according to the invention. According to these embodiments, the symmetric rim 4 is angled at different degrees relative to the top surface, illustrating the effect of varying angles on the disc's flight characteristics.

[0069] The images of fig. 8 illustrates how the pressure distribution at the upper and lower side of the rim 4 changes in relation to the angle of the line s.

[0070] Golf disc C represents an overstable golf disc with a 5-degree upward angle, golf disc D represents a stable golf disc with a 0-degree angle, and golf disc E represents an understable golf disc with a 5-degree downward angle. The images in fig. 8 demonstrate the impact of an elliptical edge angle on the flight characteristics of the golf disc, illustrating the possibility for adapting the design to create discs with varying stability levels.

[0071] In general, a golf disc according to the invention is stabilized by a gyroscopic effect when thrown, this does not happen when throwing a golf disc having a rim with an airfoil profile. The gyroscopic effect is a stabilizing force during the golf disc's flight, and for a golf disc according to the invention this effect might be optimized by creating a uniform pressure distribution on both the upper and lower surfaces 9, 10 of the rim 4. This effect is not obtained with golf discs according to earlier patents, such as US4568297A and GB2410905A, where a golf disc is considered as a wing with a specific airfoil profile. By focusing on the gyroscopic effect, a golf disc obtain surprisingly improved flight dynamics.

[0072] The golf discs C, D and E according to the invention will fly the same distance if thrown the same way, but the overstable golf disc C will turn right during the flight whereas the understable golf disc E will turn left during the flight.

[0073] Traditional golf discs exhibit a susceptibility to external forces, such as wind, which can impact the edge of the disc, causing it to tilt or turn at a 90-degree angle from the point of force impact due to gyroscopic precession. This often results in unpredictable flight paths and reduced control, as the standard disc edge shape is more prone to alterations in pressure dynamics, leading to aerodynamic imbalances during flight.

[0074] Especially an elliptical shaped rim allows for the distribution of more weight towards the edge, increasing the centrifugal force during rotation and resulting in longer and more stable throws, regardless of wind conditions. Additionally, a rounded form of the rim 4 improves the golf disc's durability by eliminating sharp edges that can bend or break during powerful throws, making the golf disc more resistant to wear and suitable for repeated throws and rough terrain. A less sharp edge is also gentler on tree bark upon impact, reducing damage to trees and the environment.

[0075] Normally, a golf disc used for competitions should meet the technical requirements for use in PDGA competitions, i.e. the golf disc may have a diameter between 21 cm and 25 cm and a weight limit of 8.3 grams per centimeter in diameter.

[0076] The width W of the rim 4 normally ranges from 12 mm to 26 mm, with an elliptical shaped rim 4 according to the invention, this dimension may improve even pressure distribution on both the top and bottom surfaces.

[0077] The present invention provides an improved golf disc that provides increased stability, control, and precision for players under various wind conditions. The environmentally friendly and durable construction of the golf disc makes it more suitable for long-term use and less harmful to the environment.

[0078] A golf disc according to the invention may be adapted for various skill levels, from beginner to professional players. By adapting the shape and dimensions of the rim 4 a golf disc according to the invention may offer improved stability, control, and precision under various wind conditions, providing a competitive advantage for players. Manufacturers can use this innovative design to produce golf discs with different flight characteristics, such as understable, stable, and overstable flight patterns, by adjusting the angle of the long axis of the elliptical edge relative to the disc's top surface. By altering this angle, manufacturers can create a range of golf discs with specific flight characteristics to suit individual player preferences and skill levels.

[0079] For example, by angling the long axis of the elliptical edge -4 degrees downward in the disc's flight direction, an understable golf disc can be produced. This is because the air pressure on the top side of the edge will be greater, affecting the gyroscopic effect, and causing the disc to tilt 90 degrees relative to the direction it is affected.

[0080] On the other hand, by angling the long axis of the elliptical edge -4 degrees upward in the disc's flight direction, an overstable golf disc can be produced. This is due to the increased air pressure on the bottom side of the edge, which affects the gyroscopic effect and causes the disc to tilt 90 degrees relative to the direction it is affected.

[0081] It is important to note that the invention does not involve a single golf disc with an adjustable edge angle; rather, it enables the production of different golf discs with varying flight characteristics based on the elliptical edge design.

[0082] In conclusion, the present invention provides a valuable addition to the disc golf market by offering an innovative golf disc design that caters to various player preferences and skill levels. The unique elliptical edge shape and even pressure distribution contribute to the disc's improved stability, control, and precision, making it a desirable choice for players seeking to enhance their performance on the course. Furthermore, the golf disc can float on water, preventing loss and environmental pollution. This feature adds to the environmentally friendly and durable construction of the golf disc, ensuring its longevity and reducing its impact on the environment, aligning with sustainable practices within the sport.

Claims

Claims:

1. A golf disc comprising an upper flight plate surface (2), a lower flight plate surface (3) and a rim (4) connecting the upper flight plate surface (2) and the lower flight plate surface (3) as a contiguous piece,- the lower flight plate surface (3) comprises a central opening (5) defined by an upper inner rim edge (7) and a lower inner rim edge (6),- the rim (4) comprises an upper rim surface (9), a lower rim surface (10) and an outer rim edge (8) defining the outer diameter (DI) of the golf disc,- the upper rim surface (9) and the lower rim surface (10) both have a convexly curved profile, and the profile of the rim (4) is elliptic, characterized in that the rim (4) has a profile corresponding to the half of an ellipse having a major axis with length 2W and a minor axis with length (H3+H4).

2. A golf disc according to claim 1, wherein the profile of the rim (4) has a tangent t in the point defined by the outer rim edge (8) i.e. the outer rim edge is rounded.

3. A golf disc according to any previous claim, wherein the profile of the upper rim surface (9) and the profile of the lower rim surface (10) mirrors each other around a symmetry line through a point defined by the outer rim edge (8).4.. A golf disc according to any previous claim, wherein the upper flight plate surface (2) is flat i.e. has a profile of a straight line, from a profile point defined by the upper inner rim (7) or for a central area within the upper inner rim edge (7).

5. A golf disc according to any previous claim, wherein the golf disc (19 is constituted of a material having a density below 999 kg / m3, preferably the golf disc is constituted of a polymer such as thermoplastic polyurethane (TPU) or polyethylene (PE), or polypropylene (PP), or ethylene-vinyl acetate (EVA), or polyvinyl chloride (PVC).

6. A golf disc according to any previous claim, wherein the width W of the rim (4) is < 30 mm, or < 28 mm, or < 26 mm, or < 25 mm.

7. A golf disc according to any previous claim, wherein at least 90% of the total weight of the golf disc (1) is distributed in the rim (4) to increase the centrifugal force during rotation.

8. A golf disc according to any previous claim, wherein the angle of the symmetry line s of the rim (4) relative to the upper flight surface (2) is between -10 degrees and +10 degrees allowing to provide understable, stable, or overstable flight patterns.

Images