Patent Application
20100240472
The present invention generally relates to golf balls. Particularly, the invention is directed to improved golf balls having a plurality of dimples forming indicia.
Golf balls are routinely marked with various surface indicia, such as the manufacturer's logo and trademark, and the play number, which allows golfers using the same type of golf ball to distinguish one player's ball from that of another. Additional symbols that may also be applied to golf balls include custom figures for promotional purposes as well as specific marks reflecting manufacturing information. There are different approaches commonly used, mostly water-based or solvent-based ink printing systems, for adding indicia to the dimpled outer surface of a golf ball. However, such conventional ink-based indicia are not sufficiently durable (impact resistant) to withstand multiple impacts with a golf club.
During the first half of the 20th century it was a common practice to mold the brand name of a golf ball directly into the ball's outer surface either as raised or recessed text. If recessed, it was sometimes paint-filled to increase visibility. This type of text was small, markings typically less than 0.010″ in height, and occupied a small portion of the ball's surface in a small area on each pole. The area was typically a small rectangular patch containing the name in a single line of text, or a circular patch of ½″ diameter or less. The texts replaced the dimples and had no connection or contact with the remaining dimples. The texts were merely a way of identifying the ball type at a time when modern printing techniques and durable inks were not available.
U.S. Pat. No. 7,273,426 to Sato et al. discloses a golf ball having markings of letters or figures on its surface with concave parts and/or convex parts, wherein the markings manifest themselves with depressions and/or grooves having a substantially uniform depth from the surface. The depressions are formed on the walls of the dimples and over the land existing between adjacent dimples.
U.S. Pat. No. 7,303,492 to Aoyama et al. discloses a golf ball comprising an outer spherical surface including a plurality of dimples that form indicia. These dimples are depressions that take the form of text letters, markings or other symbols, and occupy a substantial portion of the ball's surface in a repeating, distributed pattern.
However, there still remains a need for golf balls comprising dimples interacting with raised indicia to provide unique identification and patterns to the balls without using inks.
The present invention concerns a golf ball with dimples comprising markings that are raised geometric elements. The raised markings interact with and become components of dimples themselves rather than being additions or replacements for dimples. Innovatively, the markings increase the perimeter of dimples thereby providing a means to control and improve aerodynamic performance.
In one embodiment, the present invention is directed to a golf ball comprising a first set of dimples, a second set of dimples, and a land area. The first set of dimples has at least one dimple comprising circumference c. The second set of dimples comprises at least one marking within at least one dimple comprising n subcomponents. The at least one dimple comprising n subcomponents has a total perimeter value provided by the expression
where p is the perimeter of the each subcomponent and n is at least two, and wherein the value of P is at least about 1.10c.
In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:
Referring to
As used herein, the quantity “aggregate global dimple perimeter value” (“AGDPV”) represents the sum of perimeters for all dimples 15, 20 in a given golf ball 10. This quantity is distinguished from the “total individual perimeter value” of a single dimple, which can mean either the circumference of a single dimple 15, or if a dimple 20 has two or more subcomponents n then the quantity refers to the sum of perimeters of n subcomponents. As used herein, “perimeter” and “circumference” are measured along the land surface or along an elevation substantially the same as the elevation of the land surface.
As used herein, the terms “marking,” “character,” “indicia,” “logo,” “image,” and “pattern” are the same for purposes of this invention and are considered to mean any letter, number, symbol, icon, design, bar code, or the like, that can be added to the three-dimensional spherical surface of a golf ball 10. Markings 30 can be added by any suitable means including, but not limited to, producing a master pattern or hob comprising said markings 30. Further information about hobs can be found in U.S. Pat. Nos. 3,831,423 and 6,726,869, which are incorporated herein by reference in their entireties.
With respect to markings 30, there may be numerous variations of location, orientation, frequency and marking(s) selection, thereby increasing the possible number of design permutations.
The advantage of markings 30 can be better understood by comparing an inventive dimple 20 with a conventional dimple 15 as depicted in
where the value of n is at least two (i.e., there are a minimum of two subcomponents), or at least three, or at least four. For example, dimple 20 in
The advantage of increased perimeter quantities (i.e., all the individual total perimeter values and the collective aggregate dimple perimeter value) can be appreciated by understanding the aerodynamics of a golf ball 10. As illustrated in
The dimples 15, 20 on golf ball 10 cause the thin boundary layer to flow in a turbulent manner. Rather than flowing in smooth, continuous layers (i.e., a laminar boundary layer), this turbulent boundary layer has a microscopic pattern of fluctuations and randomized flow. It is the circumference/perimeter of each dimple 15, 20, where the dimple wall drops away from the outer surface of the ball, which actually creates the turbulence in the boundary layer. The turbulence energizes the boundary layer and helps move the separation point S1 further backward, so that the layer stays attached further along the ball's outer surface. As a result, there is a reduction in the area of the wake, an increase in the pressure behind the ball, and a substantial reduction in drag. Thus, given the role of the circumference/perimeter of each dimple 15, 20 in creating a turbulent boundary layer, it may be advantageous to increase total individual dimple perimeter values and the aggregate global dimple perimeter value so as to improve the golf ball's aerodynamic performance.
The dimples of the present invention can be arranged in an icosahedron pattern, or other suitable polyhedron patterns including, but not limited to, octahedrons (8-sided polyhedrons), dodecahedrons (12-sided polyhedrons), icosidodecahedrons (polyhedrons with twenty triangular faces and twelve pentagonal faces), and various dipyramids (polyhedrons formed from two n-agonal pyramids placed symmetrically base-to-base).
The dimple patterns of the present invention can be used with any type of golf ball with any playing characteristics. For example, the dimple pattern can be used with conventional golf balls, solid or wound. These balls typically have at least one core layer and at least one cover layer. Wound balls typically have a spherical solid rubber or liquid filled center with a tensioned elastomeric thread wound thereon. Wound balls typically travel a shorter distance, however, when struck as compared to a two piece ball. The cores of solid balls are generally formed of a polybutadiene composition. In addition to one-piece cores, solid cores can also contain a number of layers, such as in a dual core golf ball. Covers, for solid or wound balls, are generally formed of ionomer resins, balata, or polyurethane, and can consist of a single layer or include a plurality of layers and, optionally, at least one intermediate layer disposed about the core.
While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives of the present invention, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. For instance, the cross-sectional shape can be circular or also catenary, elliptical, conical, among others. Similarly, the dimple perimeter shape is not limited to being circular in plan view, but it could also have polygonal, oval, or irregular plan form shapes, among others. There are also no restrictions on the side walls of indicia elements, given that the number of intersections with dimple perimeter could be zero or greater. Further discussion of golf ball dimple patterns may be found in U.S. Pat. No. 7,303,491, which is incorporated herein by reference in its entirety. Additionally, feature(s) and/or element(s) from any embodiment may be used singly or in combination with other embodiment(s) and steps or elements from methods in accordance with the present invention can be executed or performed in any suitable order. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.
