1. Technical Field
The present invention pertains to an improved method and apparatus for marking golf balls.
2. Status of the Relevant Art
Proper putting alignment and stroke are two of the most difficult aspects of the game of golf, and accurate putting is one of the most important requisites for a good golf score. Most golfers have difficulty properly aligning a putter club head with a golf ball along an intended direction of ball travel and accurately stroking the putter club head through the ball along that direction. The ball striking surface must remain perpendicular to the direction of club head travel during the putting stroke, and the club head must be moved along the precise direction line of the putt to avoid hitting the ball off-line or imparting an undesired spin to the ball.
With this in mind, it is known in the prior art to provide at least one equatorial ball alignment marking line extending around the golf ball. The golf ball may then be positioned with the equatorial marking line lying within a vertical plane that is perpendicular to the putting green and that includes the direction in which the golf ball is to be struck. This arrangement facilitates proper initial alignment of a golf club putter face with a golf ball relative to a putt target line; i.e., by providing markings on the golf ball through which the golf ball is initially aligned with the target direction, resulting in accurate putter head alignment with both the golf ball and the target direction.
It is also known in the prior art to place markings on golf balls for a variety of purposes, chief among which is providing a true putting line to assist in lining up and stroking putts. For examples of prior patents disclosing ball marking methods and apparatus, see: U.S. Pat. Nos.: 6,595,128 (Parks); 6,216,587 (Foley); 6,004,223 (Newcomb); 5,662,530 (Sellar); 5,564,707 (Dinh); 4,974,511 (Hsi-Chou); 4,441,716 (Chen); 4,258,921 (Worst); 4,209,172 (Yamamoto); 3,753,565 (Baker); 3,420,529 (Goranson et al); 2,709,595 (De Vries); 1,842,944 (O'Brien); and 676,506 (Knight et al). The disclosures in these patents are incorporated herein by reference in their entireties. The principal drawbacks of the Chen and Hsi-Chou devices reside in their complexity in marking the ball and, in the case of Chen, using the marked ball. The Hsi-Chou device utilizes an electric motor-driven device for determining the center of gravity of a golf ball, so that the ball can be struck in the center plane to ensure true flight. Chen utilizes a complex grid pattern placed on the ball or on a ball holder which allows the golfer to gauge where the ball is being hit. Neither system addresses how to have the golfer find the true putting line on a green.
It is also known to provide templates or stencils to permit a golfer to draw equatorial lines on a golf ball. Typical of prior devices of this type are disclosed in the Parks and Foley patents. Foley and Parks attempt to provide equatorial lines (i.e., along great circles) on the golf ball surface using a resilient, partially spherical ball receptacle having cut-out or stencil portions that can be used to guide a pencil or marker, or the like, to provide a linear marking along the surface of the received ball. The interior surface of the receptacle is contoured such that the ball resides with a portion of a great circle of the ball aligned with the cut-out linear region, whereby the marked line lies along a portion of that great circle. One major problem with this type of device is that the resilient material of the receptacles must be stretched considerably during insertion and removal of the ball, thereby leaving the receptacle vulnerable to rupture after several uses.
It is an object of the invention to provide a simple and reliable apparatus and method for applying guide lines or markings on golf balls to assist a golfer in properly aligning a golf club head with the marked ball to enhance stroke accuracy.
It is another object of the invention to provide a golf ball marking unit that permits reliable and simple marking of putting path alignment lines on both sides of a golf ball.
Another object of the invention is to provide a golf ball marking unit that permits reliable and simple marking of putter face squareness lines on a golf ball to assist a golfer to maintain the putter face square with the ball and putting path through putting stroke impact.
Yet another object of the invention is to provide a golf ball marking unit that permits reliable and simple marking of lines to help promote a proper swing path for golf swings.
The above stated objects are achieved by the present invention individually and in combination and are not to be construed so as to limit the scope of the invention.
In accordance with the present invention a golf ball marking unit comprises two stencil members, each comprising a respective cap having an interior surface in the form of a segment of a hollow sphere. The caps are resiliently pivotally hinged together at a section of their peripheries by a torsion spring and positioned with their concave interior surfaces in mutually facing relation. The radius of curvature of the interior surface of each cap is substantially equal to the radius of a standard golf ball which most typically is approximately 0.84 inches. The spring serves to pivotally bias the two caps toward one another in a closed position in which their interiorly facing concave surfaces define a volume between them which is smaller than the volume of a golf ball. Respective aligned tabs extend outwardly from the hinge region of each stencil member and are finger-actuable (i.e., with pinching force applied between a person's thumb and forefinger to respective tabs) to pivotally spread the caps apart and thereby open the space between them to receive a golf ball. Release of the tabs permits the spring bias to firmly close the caps about the inserted ball. The concave interior surfaces of the caps are arcuately contoured to match the outer contour of the retained golf ball in close proximity. The trapped golf ball is gripped with sufficient force to prevent the ball from inadvertently spinning or otherwise moving relative to the stencil member caps. Respective linearly arcuate stencil slots or apertures are defined through the caps and extend circumferentially in a common plane corresponding to that of an equator or great circle of the retained golf ball. In the preferred embodiment the slot in one of the spherical caps subtends an angle of approximately 150° and the slot in the other spherical cap subtends an angle of approximately 110°. It is to be understood that these angles are for a particular preferred embodiment and are not limiting on the scope of the invention. Other stencil slots may be provided in the caps to permit markings on a golf ball that assist golfers in guiding strokes other than putting.
A marker pen may be used to draw line segments through the stencil slots on and along the corresponding great circle of the trapped golf ball. Also as part of the preferred embodiment, aligned arcuate cutout sections are defined in the circumferential edge of one or both of the stencil members. These cut out sections are configured to receive a marker pen, or the like, which may be packaged and sold with the marking unit as a single product.
The stencil assembly permits a golf ball to be marked with two long line segments residing in a common equatorial circle on the periphery of a golf ball and covering approximately 260° of that circle. When the ball rolls after being struck by a putter, the two lines should remain in a vertical plane if the putting stroke was accurately directed, or wobble out of verticality if the stroke was incorrectly directed. In any case, the golfer will receive immediate visual feedback regarding the correctness of the putting stroke. In addition, the marked lines permit the golfer to more easily align the putter head prior to the stroke.
The above and still further features and advantages of the present invention will become apparent upon consideration of the following definitions, descriptions and descriptive figures of specific embodiments thereof wherein like reference numerals in the various figures are utilized to designate like components. While these descriptions go into specific details of the invention, it should be understood that variations may and do exist and would be apparent to those skilled in the art based on the descriptions herein.
The following detailed description of the preferred embodiment makes reference to all of the accompanying drawings wherein like reference numerals refer to like components in the several figures. The dimensions shown in the drawings are by way of example of one operative embodiment only and should not be construed as limiting on the scope of the invention.
Referring to the drawings in greater detail, a golf ball marking unit 10 comprises a top stencil member 11 and bottom stencil member 12, each including a respective cap 13, 14 having an interior surface in the form of a segment of a hollow sphere. Stencil members 11, 12 are separate rigid (i.e., not significantly flexible or resilient) members made from a suitable molded polymer material such as, by way of example, acrylonitrile butadiene styrene (ABS). The thickness of the stencil members in the preferred embodiment, again by way of example only, is approximately 2.5 mm. Stencil members 11, 12 are pivotally joined at a rearward section of their peripheries by a torsion spring 17 and are positioned with the concave interior surfaces of caps 13, 14 in mutually facing relation. Spring 17, in addition to joining the two stencil members 11, 12, serves to resiliently bias the caps 13, 14 toward one another to a fully closed position in which their interiorly facing concave surfaces define a volume between them which is smaller than the volume of a standard golf ball 20, as best illustrated in
The mutually facing concave interior surfaces of caps 13, 14 are arcuately contoured to match a portion of the outer contour of the retained golf ball 20 in close proximity. Golf balls typically have an outer diameter on the order of 1.68 inches, and the curvature of the interior surfaces of caps 13, 14 is appropriately defined. The physical parameters of torsion spring 17 are chosen such that the trapped golf ball is gripped by caps 13, 14 with sufficient force to prevent the ball from inadvertently moving within the closed stencil members 11, 12. Putt path alignment stencil slots 21, 22 or similar apertures are defined through respective caps 13, 14 and extend circumferentially in a common plane corresponding to that of an equator or great circle of the caps and the retained golf ball 20. These slots, as described below, permit a golfer to mark putt path alignment line segments on golf ball 20. In the preferred embodiment the putt path alignment slot 21 in cap 13 subtends a circumferential angle of approximately 150°, and putt path alignment slot 22 in cap 14 subtends an angle of approximately 110°, thereby permitting two spaced coplanar line segments covering a total of 260° to be marked on a golf ball. Slots 21, 22 are circumferentially spaced by 40° at the rearward end (i.e., closest to the pivot axis of spring 17) of the unit and by 60° at the forward end of the unit. The resulting putt path alignment lines cover a sufficient part of the circumference along a great circle of golf ball 20 to appear substantially continuous to the golfer's eye as the ball is rolling after being struck by a putter. It is to be understood that these slot circumferential lengths (i.e., angles) are for stated for a particular preferred embodiment and are not limiting on the scope of the invention. In other words, other stencil slot configurations and locations may be defined through the caps to permit markings on golf ball that assist golfers in guiding strokes other than putting. Moreover, instead of being provided as two putt path alignment slots 21, 22, each of those slots can be segmented into two, three, or more slots spaced along the described great circle.
As best illustrated in
Referring still to
Top stencil member 11 may optionally include, in addition to stencil slot 21, two additional stencil slots 23, 24 defined therethough. Stencil slots 23, 24 are putter face squareness slots that extend from opposite sides of slot 21 and reside in an equatorial circle in a plane perpendicular to the plane of slots 21, 22 and to plane 30. Slots 23, 24 are between 40° and 60° in circumferential length and permit lines to be marked on the golf ball in a plane parallel to the putter face at the time of impact with the ball, thereby facilitating putter face alignment prior to a putting stroke. The side walls of slots 21, 22, 23 and 24 and other stencil slots described herein are chamfered (i.e., converging inward toward the retained golf ball) to provide guide surfaces for the conical tip of a marker pen when the tip is inserted through the slot during a ball marking operation. In the preferred embodiment the chamfer angle between opposite sides of the slot is on the order of 80° throughout most of the slot length and decreases gradually at the slot ends to approximately 40° to help guide the marker pen tip out of the slot at the end of a marking stroke. In a preferred embodiment the width of the slots throughout the major portions of their lengths tapers, as a result of the chamfer, from approximately 0.2 inches to approximately 0.07 inches.
Referring to
Bottom stencil member 12, in addition to stencil slot 22, preferably has four separate swing path stencil slots 41, 42, 43 and 44 defined therein, each extending at an angle of approximately 30° relative to slot 22. Slots 41 and 43 are symmetrically located at transversely opposite sides of the forward portion of slot 22 and diverge forwardly. Slots 42 and 44 are symmetrically located at transversely opposite sides of the rearward portion of slot 22 and diverge rearwardly. Slots 41 and 42 are co-linear and slots 43 and 44 are co-linear. Each co-linear pair of swing path stencil slots permits a respective pair of swing path lines to be marked on a ball retained between caps 13, 14. To this end, the rearward terminus of slots 42 and 44 are provided with arrowhead cut outs to designate swing path direction on the marked golf ball.
Torsion spring 17 has its coil diameter configured to permit the spring to reside in the four co-linearly aligned apertures defined in respective flanges 26, 27, 28 and 29. The ends of the spring extend through flanges 28, 29 and are bent such that each urges a respective tab 15, 17 away from the other tab, thereby biasing the unit caps 13, 14 toward their closed position. The unit may be forced to its open position as illustrated in
As illustrated in
The marking unit 10 and marker 50 may be packaged on a display card as part of a point of purchase display package for the unit. Depending on the nature of the card, the unit can be positioned in various manners for display. In any case, the depth or thickness of the packaged unit is smaller than the diameter of a golf ball, thereby minimizing display shelf and display space requirements without sacrificing display visibility of the item.
The invention as described herein uses two caps, resiliently biased toward one another, and having interior surfaces in the shape of spherical segments that define a cavity therebetween to securely retain a golf ball so that two sides of the ball can be easily and accurately marked with golf stroke guide lines applied through slots defined through the caps. The cavity periphery is contoured to permit a marker pen to be engaged partially therein when the cavity does not contain a golf ball.
As briefly noted hereinabove, the marking unit may have printed indicia thereon describing the function of the various stencil slots 21-24 and 41-44. For example, characters spelling “Putting Line” may be printed on the exposed surface of cap 13 adjacent slot 21 and/or on the exposed surface of cap 14 adjacent slot 22. Likewise, characters spelling “Putter Face” may be printed on the exposed surface of cap 13 adjacent slots 23 and 24. Characters spelling “Swing Path” may be printed on the exposed surface of cap 14 adjacent swing path slots 41-44.
In a preferred embodiment, in addition to the exemplary dimensions described hereinabove, the marking unit may have the following exemplary dimensions which are provided herein solely as an example for a particular unit and are not to be construed as limiting the scope of the invention: length of unit from distal end of tabs 15, 16 to forward end of tip 25: 2.49 inches; width of unit across tab 15 (or 16): 1.69 inches; height of unit in fully closed position (between apices of caps): 1.3 inches; radius of curvature of recesses 51, 52: 0.43 inches.
As seen in the accompanying drawings, the marking unit is configured so that the caps 13, 14 do not completely cover or enclose golf ball 20 when the caps are closed about the retained ball. Such complete covering may, of course be provided in other embodiments of the invention but it would require more polymer material, thereby increasing the manufacturing cost, and would increase the size of marking unit 10, particularly in its fully closed position, thereby increasing the size of the point of purchase packaging. These factors significantly outweigh the small increase in the length of slots 21, 22 that would be made possible in a unit providing for complete covering of the retained golf ball. The important point here is that the coverage of the retained ball by caps 13, 14, including tip 25, should be sufficient to include the desired stencil slots 21-24 and 41-44, and to hold the retained ball motionless under the force of spring 17 during a marking procedure. Viewed analogously, stencil member 11 and 12 each contact and cover less than half of the surface of the retained golf ball, typically on the order of twenty to thirty-five percent of that surface. This provides for a wide latitude of permissible ball surface coverage, depending on the spring force, and it has been found that good results are obtained with total coverage of between thirty and eighty percent of the ball surface, including the area of the stencil slots as part of the coverage, with about fifty percent coverage being very workable.
Several variations from the details of the disclosed embodiment will be suggested and become apparent to persons of ordinary skill in the art. For example, the spring bias need not be provided by a separate torsion spring but may instead comprise a living hinge joining the two stencil members as an integral unit. Likewise, the cap segments are shown in the drawings to be solid throughout (except, of course, for the marking slots); however, it will be understood that, to conserve material cost the caps can be apertured at various locations. Further, the marking slots 21-24 and 41-44 need not be continuous but instead may be interrupted line segments or similar linearly aligned apertures that permit the marking indicia on the retained ball to be dashed, dotted or otherwise segmented rather than continuous lines. These and other variations from the disclosed embodiment are intended to fall within the scope of the present invention.
The marking tool of the present invention has the following unique and advantageous features:
It is to be understood that terms such as “bottom”, “front”, “rear”, “side”, “width”, “upper”, “lower”, “interior”, “exterior”, “inner”, “outer” and the like as used herein, merely describe points of reference and do not limit the present invention to any particular orientation or configuration.
While the invention has been described in detail and with reference to a specific embodiment thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. For this reason it is submitted that the invention should be measured by the scope of the attached claims and their equivalents rather than by the specific details of the preferred embodiment disclosed herein.
This application claims priority from U.S. Provisional Patent Application Ser. No. 61/106,772 entitled “Golf Ball Marking Stencil”, filed Oct. 20, 2008. The disclosure of this provisional patent application is incorporated herein by reference in its entirety.
Number | Date | Country | |
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61106772 | Oct 2008 | US |