U.S. patent number 3,796,435 [Application Number 05/287,055] was granted by the patent office on 1974-03-12 for golf putting practice device.
Invention is credited to James Thomas Dale.
United States Patent |
3,796,435 |
Dale |
March 12, 1974 |
GOLF PUTTING PRACTICE DEVICE
Abstract
A wheel-shaped device having a dimpled peripheral surface, and a
diameter and weight corresponding to that of a U.S.G.A. approved
golf ball. About 75 percent of the weight is concentrated in a
heavy metal cylinder having approximately a one-half inch diameter
and axially distributed near the central portion of the device. The
object is to provide an exaggerated off-target directional motion
of the device when it is struck by a golf putter club at an
improper angle. Lightweight spherical dimpled elements may be
attached to opposite sides of the device to produce the appearance
of a golf ball in the shape of a sphere.
Inventors: |
Dale; James Thomas (Rancho
Mirage, CA) |
Family
ID: |
23101272 |
Appl.
No.: |
05/287,055 |
Filed: |
September 7, 1972 |
Current U.S.
Class: |
473/200 |
Current CPC
Class: |
A63B
69/3688 (20130101) |
Current International
Class: |
A63B
69/36 (20060101); A63b 069/36 () |
Field of
Search: |
;273/128,199,183,213,200 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Golf Digest," June 1970, page 112, Volume 21, No. 6..
|
Primary Examiner: Marlo; George J.
Attorney, Agent or Firm: Tarr; Thomas A.
Claims
1. A device for improving the putting ability of a golfer
comprising, wheel-shaped means having approximately the same
weight, diameter, and dimpled surface characteristic as a standard
golf ball, and a cylindrical relatively heavy mass in the hub of
said wheel-shaped means, said mass having about 75 percent of the
weight of said device and having a
2. A device in accordance with claim 1 in which opposite sides
thereof are covered with a lightweight, partially spherical dimpled
material which produces the apperance of a standard golf ball.
Description
In the game of golf, the last stroke or two at the end of each hole
is commonly known as a putt. It is an object of this invention to
provide a device which will enable a golfer to determine the
accuracy of the striking attitude of the golf club against a
surface which simulates a golf ball surface. It is a further object
to construct such a device which responds rapidly in such a manner
that inaccuracy in striking the ball is obvious to the golfer.
Another object is to construct a practice putting device with the
same weight and "feel" to a putting stroke as a standard golf
ball.
The novel features that are considered characteristic of this
invention itself will best be understood from the following
description when read in connection with the accompaning drawings,
in which:
FIG. 1 is a perspective view of one example of the invention; FIG.
2 is a side elevation view; FIG. 3 is a schematic drawing showing a
stroking surface contacting the rounded surface of putter practice
device tangentially adn the path taken by the device in reaction;
and FIG. 4 is a schematic drawing showing a stroking surface
contacting the rounded surface of the putter practice device at an
angle from a tangent to the curved surface of the device.
In FIG. 1, the outer curved surface defines a symmetrical segment
of a sphere in which curved surface 1 is exactly equal in curvature
and spherical diameter to an equivalent segment from a standard
golf ball. The width of the segment is approximately 0.66 inches
measured along an edge to edge chord of the segment. The surface
contains symmetrical pitted areas identical to the standard golf
ball.
In FIG. 2, rim 2 of the device is undercut from edge 3 to an inner
rim 4. The depth of the undercut is about 0.15 inch on each side of
the device, for a purpose to be described later. Inner rim 4
defines the outer edge of a collar 5 which confines a relatively
heavy cylindrical mass 6 which is preferably made from lead. Mass 6
is about 0.5 inches in diameter and about 0.66 inches in length,
and preferably the same length as the width of the cylindrical
segment. Such a lead mass weighs about 1.2 ounces. The materials of
the device, excluding the mass 6 is of a plastic material or hard
rubber which simulates the appearance and feel of a standard golf
ball. The weight of the plastic is about 0.42 ounces, therefore,
approximately 75 percent of the weight of the putting device, which
totals 1.62 ounces, is concentrated in the 0.5 inch central mass 6.
The total weight is within the tolerances of a standard golf ball
as approved by the United States Golfing Association. As previously
mentioned, the putting device is undercut between edge 3 and inner
rim 4. The reduction of mass between collar 5 and outer rim 2
assists in concentrating the mass toward the center of the putting
device.
In FIG. 3, a portion of a putter club 7 is shown with surface 8
which strikes the ball. If striking surface 8 moves along a path
indicated by arrows 10, which path is perpendicular to surface 8
and which contacts the putting device in the center of curved
surface 9, then the putting device reacts by moving in the intended
path shown by arrows 11.
In FIG. 4, the putter club 7 is shown with surface 8 inclined at an
angle from the perpendicular path of FIG. 3. For purposes of
illustration, the angle is much exaggerated. It has been found that
even a 1.degree. inclination of the striking face of the putter
causes a substantial deviation in the direction traveled by the
putting device. The concentration of mass at the center of the
putting device increases the effect of any errors in striking the
surface of the putting device. High speed photographs show that for
several feet after the putter device has been struck at even a very
slight angle, the device oscillates about a vertical axis, then the
rotation is stabilized and the device continues rolling without
oscillation, in a direction away from the intended path. The
initial oscillation is presumably caused by the dynamic unbalance
of the putting device as it rotates around an unsymmetrical axial
plane.
In both FIG. 1 and FIG. 2, it is readily noticeable that the
putting device resembles a wheel. It has been found that a light
weight decorative cover (not shown) can be inserted in the wheel to
conceal the undercut area, collar 5, and mass 6. The cover is
installed on both sides of the putting device to provide a more
pleasing appearance, as well as offering an area on which designs
or advertising can be displayed.
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