GOLF TEE WITH MODIFIED CONCAVE SUPPORT SURFACE

Abstract

The present invention is directed to a golf tee having a golf ball support and a stem, the support having a modified concave upper surface. The upper concave surface is configured to reduce the support interference angle. During play, a portion of the stem is inserted into the course surface (e.g., tee box surface, soil, sand), at an angle substantially perpendicular to the course surface and at a depth sufficient to allow the golf tee to support or tee up a golf ball. When teed, the golf ball nests within a support recess defined by the modified concave upper surface.

Claims

1. A golf tee for supporting a golf ball having a cap-shaped nesting portion, the golf tee having a long axis and a vertical plane extending parallel to the golf tee long axis; the golf tee comprising a golf ball support and a stem, the golf ball support having a concave upper surface defining a concave recess having a vertical recess height; the golf ball cap-shaped nesting portion having a vertical cap height, the vertical recess height equals the vertical cap height.

2. The golf tee of claim 1, the golf tee having a short axis and a horizontal plane extending parallel to the golf tee short axis; the golf ball support concave recess having a horizontal recess width; and the golf ball cap-shaped nesting portion having a base, the base having a horizontal base radius; $\mathrm{wherein}\left(\mathrm{horizontal}\mathrm{recess}\mathrm{width}\right)>2\left(\mathrm{horizontal}\mathrm{base}\mathrm{radius}\right)>0.$

3. The golf tee of claim 2, the ball having a ball radius and the golf tee support recess having a recess radius; $\mathrm{wherein}0<\left(\mathrm{ball}\mathrm{radius}\right)<\left(\mathrm{recess}\mathrm{radius}\right).$

4. The golf tee of claim 3, wherein the golf ball has a ball radius of not less than 0.84 inches; $\mathrm{wherein}0.84\mathrm{inches}<\left(\mathrm{recess}\mathrm{radius}\right).$

5. The golf tee of claim 4, wherein the golf ball support concave recess terminates at an upper surface ridge and the golf ball support has an outer surface; the golf ball support further comprising an annulus-shaped upper surface extending from the upper surface ridge to the golf ball support outer surface.

6. The golf tee of claim 1, the ball having a ball radius and the golf tee support recess having a recess radius; $\mathrm{wherein}0<\left(\mathrm{ball}\mathrm{radius}\right)<\left(\mathrm{recess}\mathrm{radius}\right).$

7. The golf tee of claim 6, wherein the golf ball has a ball diameter of not less than 0.84 inches; $\mathrm{wherein}0.84\mathrm{inches}<\left(\mathrm{recess}\mathrm{radius}\right).$

8. The golf tee of claim 7, the golf tee having a short axis and a horizontal plane extending parallel to the golf tee short axis; the golf ball support concave recess having a horizontal recess diameter; and the golf ball cap-shaped nesting portion having a base, the base having a horizontal base radius; $\mathrm{wherein}\left(\mathrm{horizontal}\mathrm{recess}\mathrm{diameter}\right)>2\left(\mathrm{horizontal}\mathrm{base}\mathrm{radius}\right)>0.$

9. The golf tee of claim 8, wherein the golf ball support concave recess terminates at an upper surface ridge and the golf ball support has an outer surface; the golf ball support further comprising an annulus-shaped upper surface extending from the upper surface ridge to the golf ball support outer surface.

10. A golf tee for supporting a golf ball having a ball radius; the golf tee comprising a golf ball support and a stem, the golf ball support having a concave upper surface defining a concave recess having a recess radius; $\mathrm{wherein}0<\left(\mathrm{ball}\mathrm{radius}\right)<\left(\mathrm{recess}\mathrm{radius}\right).$

11. The golf tee of claim 10, wherein the golf ball has a ball diameter of not less than 0.84 inches; $\mathrm{wherein}0.84\mathrm{inches}<\left(\mathrm{recess}\mathrm{radius}\right).$

12. The golf tee of claim 11, the golf ball having a cap-shaped nesting portion, and the golf tee having a short axis and a horizontal plane extending parallel to the golf tee short axis; the golf ball support concave recess having a horizontal recess width; and the golf ball cap-shaped nesting portion having a base, the base having a horizontal base radius; $\mathrm{wherein}\left(\mathrm{horizontal}\mathrm{recess}\mathrm{width}\right)>2\left(\mathrm{horizontal}\mathrm{base}\mathrm{radius}\right)>0.$

13. The golf tee of claim 10, the golf ball having a cap-shaped nesting portion, and the golf tee having a short axis and a horizontal plane extending parallel to the golf tee short axis; the golf ball support concave recess having a horizontal recess width; and the golf ball cap-shaped nesting portion having a base, the base having a horizontal base radius; $\mathrm{wherein}\left(\mathrm{horizontal}\mathrm{recess}\mathrm{width}\right)>2\left(\mathrm{horizontal}\mathrm{base}\mathrm{radius}\right)>0.$

14. The golf tee of claim 10, wherein the golf ball support concave recess terminates at an upper surface ridge and the golf ball support has an outer surface; the golf ball support further comprising an annulus-shaped upper surface extending from the upper surface ridge to the golf ball support outer surface.

15. A golf tee for supporting a golf ball, the golf tee having a short axis and a horizontal plane extending parallel to the golf tee short axis; the golf tee comprising a golf ball support and a stem, the golf ball support having a concave upper surface defining a concave recess having horizontal recess width; the golf ball having a cap-shaped nesting portion having a base, the base having a horizontal base radius; $\mathrm{wherein}\left(\mathrm{horizontal}\mathrm{recess}\mathrm{width}\right)>2\left(\mathrm{horizontal}\mathrm{base}\mathrm{radius}\right)>0.$

16. The golf tee of claim 15, wherein the golf ball support concave recess terminates at an upper surface ridge and the golf ball support has an outer surface; the golf ball support further comprising an annulus-shaped upper surface extending from the upper surface ridge to the golf ball support outer surface.

17. The golf tee of claim 16, the golf ball having a ball radius, the golf tee having a long axis and a vertical plane extending parallel to the golf tee long axis; the golf ball support recess having a vertical recess height and the golf ball having a cap-shaped nesting portion having a vertical cap height, wherein the vertical recess height equals the vertical cap height; and the golf ball having a radius and the golf tee concave recess having a recess radius, wherein 0<(ball radius)<(recess radius).

18. The golf tee of claim 15, the golf ball having a ball radius, the golf tee having a long axis and a vertical plane extending parallel to the golf tee long axis; the golf ball support recess having a vertical recess height and the golf ball having a cap-shaped nesting portion having a vertical cap height, wherein the vertical recess height equals the vertical cap height; and the golf ball having a radius and the golf tee concave recess having a recess radius, wherein 0<(ball radius)<(recess radius).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is a side view of the top portion of a conventional golf tee.

[0029] FIG. 2 is a cross-sectional diagram of the top portion of a conventional golf tee supporting a teed ball.

[0030] FIG. 3 is a cross-sectional diagram of the top portion of a conventional golf tee illustrating the interference angle imparted by its design.

[0031] FIG. 4 is a cross-sectional diagram of the top portion of an improved golf tee and ball.

[0032] FIG. 5 is a cross-sectional diagram of the top portion of an improved golf tee supporting a teed ball.

[0033] FIG. 6 is a cross-sectional diagram of the top portion of an improved golf tee illustrating the interference angle imparted by its design.

[0034] FIG. 7 is a top view of the top portion of a conventional golf tee supporting a teed ball.

[0035] FIG. 8 is a cross-sectional diagram of the top portion of an improved golf tee and teed ball illustrating the radii of the ball and upper support surface.

DETAILED DESCRIPTION OF THE INVENTION

[0036] It has been found the modified golf tee of the present invention affords benefits over tees known in the art. Such benefits include ease of use, decreased susceptibility to inducing ball spin when the ball is struck, decreased friction between the ball surface and tee crown, and simplified construction.

[0037] Specific embodiments and benefits are apparent from the detailed description provided herein. It should be understood, however, that the detailed description and specific examples, while indicating embodiments among those preferred, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

[0038] Referring to FIG. 4, the present invention is directed to an improved golf tee 10 for supporting a teed ball 20. The tee 10 includes a ball support (crown) 12 and stem 14 having a tapered end (not illustrated). The tapered end is adapted to be perpendicularly inserted into a playing surface (not illustrated).

[0039] The support 12 has a concave upper surface 16 which defines a concave-shaped recess into which at least a portion (defined below) of the ball 20 extends when teed. The recess can be generally described as having the shape of a cap of a sphere or spheroid.

[0040] The concave upper surface 16 terminates at an upper surface ridge 16a at the outer periphery of the recess, the concave upper surface 16 further having a recess bottom or low point 16b (the most distal point from ridge 16a). A horizontal washer or annulus-shaped upper surface 17 extends substantially horizontally from the upper surface ridge 16a to outer surface 12a of the support 12 (see FIGS. 7 and 8). The annulus-shaped upper surface is intended to provide a gap between any upwardly extending protrusions (not illustrated) which may form after repeated use of the tee 10 due the impact between a golf club head and the support 12. The upwardly extending protrusions could undesirably contact the ball 20, interfering with the trajectory of the ball 20 when struck by the head of a golf club.

[0041] The recess has a vertical height (h.sub.3) defined as the linear vertical distance between the horizontally circular ridge 16a and the recess bottom 16b, and a horizontal width (a.sub.2) representing the linear width or diameter of the horizontally circular outer ridge 16a.

[0042] Referring to FIGS. 4 through 6, when the ball 20 is teed, a spherical cap-shaped nesting portion 22 of the ball 20 is supported by the support concave upper surface 16. Radial vector (r.sub.b) represents the radius of the ball 20.

[0043] The cap 22 has a horizontal top base 22a and bottom point 22b (most distal point from the base 22a).

[0044] The ball's cap-shaped nesting portion 22 has a vertical cap height (h.sub.4). The vertical cap height (h.sub.4) is defined as the linear vertical distance between the cap base 22a and ball bottom point 22b. When the ball 20 is teed, the ball cap 22 is completely nested in the recess defined by the tee concave upper surface 16. Stated differently, h.sub.3=h.sub.4.

[0045] The cap bottom 22b is the point of tangency for a ball tangent line (t.sub.b) which overlaps with a recess top plane (x) defined by the horizontal circle formed by the outer ridge 16a. The ball cap 22 is further defined as having horizontal base radius (r.sub.c) which is the linear horizontal distance between the ball bottom 22b and the outer edge of the base 22a.

[0046] As can be seen from FIG. 5, when the ball cap-shaped nesting portion 22 of the ball is supported within the support recess, the nesting portion 22 is not completely supported by the resting ridge 16a, but rather by the support surface 16. The point of contact between the ball nesting portion 22 and support surface 16 has a very small surface area as compared to conventional tees which rely on the circular resting ridge 4a to support the ball.

[0047] Referring to FIG. 6, the concave upper surface 16 can be characterized by a tangent line (t.sub.2), with the ridge 16a being the point of tangency. An interference angle (?) represents the trajectory the ball 20 must achieve when struck to avoid colliding with the concave upper surface 16 of the support 12 (assuming the ball is struck horizontally normal with no upward or downward swing by the player, using a club head face with no upward loft angle).

[0048] The interference angle (?) is defined by the angle formed by the intersection of the tangent line (t.sub.2) and the recess top plane (y.sub.2) formed by the circle defined by the outer ridge 16a.

[0049] The adjusted value of the interference angle (?.sub.adj) is determined using equation (2), wherein:

[00002]$\begin{array}{cc}{?}_{\mathrm{adj}}=?-i-l& \left(2\right)\end{array}$ [0050] (l) is the loft angle of the golf club head (l) (not illustrated); and [0051] (i) is the strike angle of the ball by the club head relative to true normal, as determined by the player's swing.

[0052] FIGS. 7 and 8 illustrate a visual comparison of the radius (r.sub.b) of the ball 20 to the vertical radius (r.sub.r) of the recess form by the support concave surface 16. Line 16c corresponds to an imaginary sphere or spheroid formed when the concave surface 16 is used as the basis to complete the imaginary structure.

[0053] As will be illustrated in the examples below and discussed in more detail, the unique relationship between the ball radius (r.sub.b) and recess radius (r.sub.r) of the recess formed by the concave recess surface 16 changes the interference angle (?). As the recess vertical height (h.sub.3) decreases, while maintaining the horizontal width (a.sub.2) of the horizontally circular outer ridge 16a, the interference angle (?) decreases. Reduction of the interference angle (?) reduces undesirable interference to the ball trajectory and spin as compared to conventional tees having greater interference angles (?).

[0054] Further, it has also been found when the recess radius (r.sub.r) of the recess formed by the concave recess surface 16 remains constant but the horizontal width (a.sub.2) of the horizontally circular outer ridge 16a is decreased, the interference angle (?) also decreases.

[0055] As illustrated in FIGS. 1 through 3, when a ball 5 teed using a conventional tee 1 during play, it is vertically statically supported by the circular upper concave surface ridge 4a. Depending on the manufacturing specifications of the conventional tee 1, it is possible the ball 5 may rest on some portion of the parabolic surface defined by the upper concave support surface 4.

[0056] However, the ball 5 will always be vertically statically supported at least in part by the upper concave surface ridge 4a because conventional thinking is a failure to so would result in the ball 5 being horizontally unstable within the cup of the crown. Stated differently, the construction of a conventional tee 1 is described as having a recess width (a.sub.1) equal to the diameter of the base of the spherical cap-shaped ball portion (based diameter=2?(r.sub.a)).

[0057] In contrast, the unique construction of the tee 10 described herein is described as statically supporting a ball 20 without the ball being entirely vertically supported by any portion of the upper surface ridge 16a. It should be noted the ball 20 may be supported horiztonally by the upper surface ridge 16a, preventing it from A comparison of the dimensions for the support recesses and spherical cap-shaped nested portions of the balls are summarized in Table 1 below.

TABLE-US-00001 TABLE 1 Conventional Improved Tee of the Tee Present Invention 0 < h.sub.2 < h.sub.1 h.sub.3 = h.sub.4 a.sub.1 = 2 .Math. (r.sub.a) a.sub.2 > 2 .Math. (r.sub.c) > 0 0 < ? < ? 0 < r.sub.r < r.sub.b 0 < r.sub.b < r.sub.r

[0058] The following examples are provided to further illustrate the present invention and are not meant to be limiting.

Examples 1-6

Comparison of Interference Angles for Tees Having Varying Support Surface Radii

[0059] As illustrated in the examples below in Table 2, the examples assume a club loft angle of 10? and a player strike angle of ?2?, as the recess vertical height (h.sub.2) decreases, so does the interference angle (?), until the adjusted interference angle (?.sub.adj, ?.sub.adj) is at or less than 0?.

TABLE-US-00002 TABLE 2 COMPARATIVE EXAMPLE 2 EXAMPLE 3 EXAMPLE 4 EXAMPLE 5 EXAMPLE 6 EXAMPLE 1 Improved Improved Improved Improved Improved Comparative Tee Tee Tee Tee Tee Tee (2r.sub.r) = 1.30 (2r.sub.r) = 1.68 (2r.sub.r) = 1.75 (2r.sub.r) = 2 (2r.sub.r) = 2.5 (2r.sub.r) = 3.02 Interference 18.91? 14.48? 13.89? 12.12? 9.67? 7.99? Angle (?, ?) Loft Angle (I) ?2? ?2? ?2? ?2? ?2? ?2? Strike Angle (i) 10? 10? 10? 10? 10? 10? Adjusted 10.91? 6.48? 5.89? 4.12? 1.67? 0.01? Interference Angle (?.sub.adj, ?.sub.adj)

Example 7

Ball Displacement Height (h.SUB.2.) Vs. Recess Height (h.SUB.1.)

[0060] A tee having a horizontal width (a.sub.1) of 0.42, a recess radius (r.sub.r) of 0.65, and a ball radius (r.sub.b) of 0.84 is examined for the relationship between the ball and recess radii (r.sub.b,r.sub.r) and nesting position of the ball within the concave recess.

[0061] Using the Intersection Cords Theorem one can calculate the vertical ball encroachment or displacement height (h.sub.2), defined as the linear vertical distance between the horizontally circular outer ridge 4a and the ball's lowest vertical point 6b when the ball is nested in the bowl-shaped recess (teed for play).

[0062] The vertical height of the bowl (h.sub.1) can be determined equation (3) below:

[00003]$\begin{array}{cc}\left(\mathrm{AE}\right)*\left(\mathrm{EB}\right)=\left(\mathrm{CE}\right)*\left(\mathrm{ED}\right)& \left(3\right)\end{array}$

wherein: [0063] (AE)=? of horizontal width (a.sub.1) representing the diameter of the bowl-shaped recess as defined by the horizontally circular outer ridge; and [0064] (EB)=? of horizontal width (a.sub.1) representing the diameter of the bowl-shaped recess as defined by the horizontally circular outer ridge;

[00004]$\left(\mathrm{CE}\right)=\left(h_1\right);\mathrm{and}\left(\mathrm{ED}\right)=2\left(r_r\right)-\left(h_1\right)\mathrm{Therefore},\left(h_1\right)=0.0349.$

[0065] The vertical ball encroachment or displacement height (h.sub.2) is calculated using equation (3), wherein CE=(h.sub.2) and ED=2?(r.sub.b)?(h.sub.2). Where (r.sub.b)=0.84, (h.sub.2)=0.0267.

[0066] The calculations above demonstrate (h.sub.2)<(h.sub.1) and therefore the ball bottom 6b does not contact the recess bottom 4b. The vertical gap between the bottom of the ball 6b and recess bottom 4b is calculated as (h.sub.1)?(h.sub.2)=0.0082. If 0<(h.sub.2)<(h.sub.1) the ball bottom 6b will not contact the concave surface 4, but if (h.sub.2)=(h.sub.1) the ball bottom 6b and recess bottom 4b make contact and the ball will not contact the recess ridge 4a.

Example 8

Interference Angle (?) for Decreasing Recess Radius (r.SUB.r.)

[0067] A comparison of tees having a horizontal width (a.sub.2) of 0.42 and recess radii (r.sub.r) of 0.65 and 1.0, are calculated and compared.

[0068] The slope of the recess tangent line (t.sub.2) is calculated using the general equation for a circle (x.sup.2+y.sup.2=r.sup.2) and slope of a line (y=mx+b), wherein b=0, and r=??(a.sub.2)=0.21.

[0069] Table 3 below shows the calculated slope (m) of the tangent line for each recess radius (r.sub.r). The interference angle (?) is the inverse tangent (tan.sup.?1) of the slope of the recess tangent line (t.sub.2).

TABLE-US-00003 TABLE 3 Tee 1 Tee 2 (r.sub.r) = 1.0 (r.sub.r) = 0.65 m = 0.2147 0.3414 (?) = 12.12? (?) = 18.85?

[0070] As Table 3 illustrates, as recess radius (r.sub.r) increases, the slope of the recess tangent line (t.sub.2) decreases as well as the interference angle (?).

Example 9

Interference Angle (?) For Decreasing Recess Widths (a.SUB.2.) and Recess Radius (r.SUB.r.)

[0071] A comparison of impact angles for tees having horizontal recess widths (a.sub.2) of 0.42 and 0.32, each with a recess radius (r.sub.r) of 1.0 and 0.65, are compared in Table 4 below.

TABLE-US-00004 TABLE 4 Tee 1 Tee 2 Tee 3 Tee 4 (r.sub.r) = 0.65 (r.sub.r) = 0.65 (r.sub.r) = 1.0 (r.sub.r) = 1.0 (a.sub.2) = 0.42 (a.sub.2) = 0.32 (a.sub.2) = 0.42 (a.sub.2) = 0.32 (?) = 18.85? (?) = 14.25? (?) = 12.12? (?) = 9.12?

[0072] As Table 4 illustrates, as recess radius (r.sub.r) increases as well as the recess width (a.sub.2), each independently reduces the interference angle (?).