U.S. patent application number 10/063903 was filed with the patent office on 2003-11-27 for apparatus for reducing unwanted asymmetric forces on a driver head during a golf swing.
Invention is credited to Anelli, Albert M..
Application Number | 20030220154 10/063903 |
Document ID | / |
Family ID | 29547838 |
Filed Date | 2003-11-27 |
United States Patent
Application |
20030220154 |
Kind Code |
A1 |
Anelli, Albert M. |
November 27, 2003 |
Apparatus for reducing unwanted asymmetric forces on a driver head
during a golf swing
Abstract
An aerodynamic apparatus that is built into or attached to a
body of a golf club head to cause the airflow over the body to
transition from smooth to turbulent at a defined length from the
striking face of a club. The device reduces asymmetric variations
in the boundary layer separation point that cause unsteady forces
on the club head and create excess unpredictable cavitation behind
the club head. The device is aligned essentially parallel to the
intersection of the striking face and the body and is situated near
the maximum thickness of the body cross-section. The device is
comprised or a small strip of material, a string, a gap, a ridge, a
groove, a step up, a step down, a surface curvature breakpoint, or
a series of geometric patterns that traverses around the entire
perimeter of the body surface either continuously or in broken
segments.
Inventors: |
Anelli, Albert M.; (Lake
Ariel, PA) |
Correspondence
Address: |
MR. ALBERT M. ANELLI
219 WIMMERS RD.
LAKE ARIEL
PA
18436
US
|
Family ID: |
29547838 |
Appl. No.: |
10/063903 |
Filed: |
May 22, 2002 |
Current U.S.
Class: |
473/327 |
Current CPC
Class: |
A63B 60/006 20200801;
A63B 53/0437 20200801; A63B 2225/01 20130101; A63B 2209/10
20130101; A63B 53/0466 20130101 |
Class at
Publication: |
473/327 |
International
Class: |
A63B 053/04 |
Claims
1. A golf club head comprising a striking face for striking a golf
ball, a body attaching to the striking face and extending around
the perimeter of the striking face, a discontinuity in the body for
controlling a boundary layer transition point on the body, and an
aft surface opposite to the striking face and closing the body.
2. The golf club head of claim 1, wherein the discontinuity is
essentially parallel to the intersecting edge of the striking face
and the body.
3. The golf club head of claim 1, wherein the discontinuity is
situated near the maximum thickness point of the cross-section of
the body.
4. The golf club head of claim 1, wherein the discontinuity is
located one half inch to two inches from the intersecting edge of
the striking face and the body.
5. The golf club head of claim 1, wherein the discontinuity is
large enough to disrupt the boundary layer but small enough not to
contribute a substantial amount of drag force.
6. The golf club head of claim 1, wherein the discontinuity is
comprised of an abrupt change in surface curvature, a gap, a step,
a grove, or surface roughness.
7. The golf club head of claim 1, wherein the discontinuity is
comprised of segments of geometric shapes, circles, triangles,
dashes, or dots.
8. A golf club head comprising a striking face for striking a golf
ball, a body attaching to the striking face and extending around
the perimeter of the striking face, a removable discontinuity on
the body for controlling a boundary layer transition point on the
body, and an aft surface opposite to the striking face and closing
the body.
9. The golf club head of claim 8, wherein the removable
discontinuity is essentially parallel to the intersecting edge of
the striking face and the body.
10. The golf club head of claim 8, wherein the removable
discontinuity is situated near the maximum thickness point of the
cross-section of the body.
11. The golf club head of claim 8, wherein the removable
discontinuity is located one half inch to two inches from the
intersecting edge of the striking face and the body.
12. The golf club head of claim 8, wherein the removable
discontinuity is large enough to disrupt the boundary layer but
small enough not to contribute a substantial amount of drag
force.
13. A trip strip to attach to a body of a golf club head to control
a boundary layer transition point on the body.
14. The trip strip of claim 13, wherein the attachment is made by
adhesive, adhesive-backing, or elastic tension.
15. The trip strip of claim 13, wherein the trip strip is designed
to be applied essentially parallel to a striking face of the golf
club at approximately the maximum cross-section thickness of the
body.
16. The trip strip of claim 13, being comprised of any number of
various cross-sections designed to disrupt the boundary layer on
the body.
17. The trip strip of claim 13 wherein the trip strip is large
enough to disrupt the boundary layer but small enough to avoid a
substantial increase of drag force.
18. The trip strip of claim 13, wherein the trip strip is formed of
segments of lines, geometric shapes, circles, triangles, or
dashes.
19. The trip strip of claim 13, wherein the trip strip is wrapped
around a hosel of the golf club head to reduce slippage and loss.
Description
BACKGROUND OF INVENTION
[0001] The invention relates to the aerodynamic design of a golf
club head and specifically to the reduction of unwanted asymmetric
aerodynamic forces on the driver or fairway-wood head just prior to
the moment of impact. The reduction of these forces allows the
player to hit the ball on the center of percussion, or sweet spot,
more easily, which creates longer, more accurate drives off the tee
and from the fairway. This invention assists all levels of golfers
to improve their performance. The invention does not apply to irons
or putters.
[0002] Many advances have been made in the field of driver or
fairway golf club head design including material advances,
trampoline effects, and drag reduction, but nothing has been
invented to reduce the forward, lateral, asymmetric forces that
introduce error at the moment of impact.
[0003] At the moment of impact a driver club head travels as high
as one hundred and forty miles per hour. The average player creates
head speeds of approximately eighty to one hundred miles per hour.
Because the distance from the driver head to the club grip creates
a long lever, very small forces on the local head translate into
much larger moment forces at the players hands. These forces must
be continually counteracted to guide the sweet spot of the club
head to strike the ball.
[0004] In a normal swing the club head twists as it rotates toward
the impact area and the club head traverses through a non-uniform
wind velocity profile. The twisting creates a changing
angle-of-attack between the golf club head and the golf club path.
The non-uniform wind velocity is the result of the players' bodies,
trees, buildings, spectators, tee boxes, or tee mounds, interfering
with the otherwise smooth wind profile. These phenomenon cause the
airflow around the face of the club head to transition from a
laminar, or attached, condition, to a turbulent, or separated,
condition at different lengths from the club head face around the
club head. It is this aerodynamic variation that causes excess
unwanted lateral forces the club head and excess non-uniform
cavitation in the airflow behind the club head.
[0005] The prior art contains numerous attempts at reducing drag
and turbulent regions behind the club head. U.S. Pat. No.
5,435,558, entitled GOLF CLUB HEAD WITH AERODYNAMIC DESIGN, tries
to control the vortices behind the club but does nothing to control
the separation distance from the club head face. U.S. Pat. No.
5,529,303, entitled GOLF CLUB HEAD, tries to control the airflow by
channeling it through the club head, but does nothing to control
the flow on the top, bottom, and side surfaces. U.S. Pat. No.
6,027,414, entitled GOLF CLUB WITH AERODYNAMIC SHAFT AND HEAD, does
not address the separation distance from the club head face. These
patents, others like them, and the patents cited during the
prosecution thereof, do not affect the variation in boundary-layer
separation distance around the club head perimeter. Further,
technology from the prior art can not be retrofitted on all
existing clubs like the present invention.
SUMMARY OF INVENTION
[0006] The present invention is an improvement on prior art golf
club heads, and overcomes the problems noted above by providing, at
a point sufficiently far forward to cause an abrupt transition of
the boundary layer and sufficiently far aft to prevent
reattachment, a discontinuity in the surface to cause an
aerodynamic disturbance. The discontinuity, or trip strip, is
approximately equidistant from the club head face and is situated
near the maximum thickness point. The trip strip is of sufficient
thickness to effect transition without a noticeable rise in drag
force.
[0007] The invention also pertains to the retrofit of trip strip
technology on existing golf club heads to bring equivalent benefits
to players that do not wish to replace their existing clubs to take
advantage of the performance improvement.
[0008] Other features and benefits of the present invention, like
the satisfaction of golf equipment requirements of regulating
bodies, will become apparent from the following description of the
invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0009] The invention will be better understood by reference to the
accompanying drawings, wherein:
[0010] FIG. 1 is a representation of a golf driver or fairway club
head with trip strip technology either built into the club head or
attached to an existing club head.
[0011] FIG. 2 is a side view of a club head with trip strip
technology.
[0012] FIG. 3 is a top view of a club head with trip strip
technology.
[0013] FIG. 4 is a representation of a second embodiment of a golf
club head with trip strip technology that is attached to an
existing club and twisted around the hosel.
[0014] FIG. 5 shows a magnified representation of alternate
cross-sectional shapes for trip strips.
[0015] FIG. 6 shows a magnified representation of alternate
patterns for trip strips.
[0016] These figures are provided to complete the description given
here as an illustration but do not impose any limitation.
DETAILED DESCRIPTION
[0017] The golf club head 1 of the present invention is shown as
the preferred embodiment in FIGS. 1 through 3. A discontinuity, or
trip strip 2 in the surface acts to disrupt the laminar flow over
the forward part of the club head 3. The trip strip lies
essentially parallel to the club face 4 near the maximum thickness
of the club head cross-section 5. The airflow is uniformally
disturbed around the majority of the surface perimeter and is
forced to transition to a turbulent flow which does not reattach to
the aft end of the club head 6. The trip strip 2 can be built into
the club as a technical feature or added to existing clubs as a
retrofit.
[0018] A second embodiment of the golf club head with trip strip
technology is shown in FIG. 4, where the trip strip 2 is wrapped
around or attached to the hosel 7 to prevent slippage and loss.
[0019] FIG. 5 shows a magnification of a representation of several
variations of other styles of trip strips that could produce an
equivalent aerodynamic effect. Cylindrical shapes 12, gaps 13,
grooves 14, a step down 15, surface curvature breaks 16, or merely
higher surface roughness like sandpaper 17 could also create the
desired aerodynamic disturbance.
[0020] Further, the trip strip need not be continuous lines. See
FIG. 6. Dashes 8, circles 9, triangles 10, or dotted line trip
strips 11 would serve the same purpose.
[0021] It should also be evident that the thickness and width of
the trip strip cross-section could vary in size and still fall
within the scope of this patent.
[0022] So it is evident that the golf club head with trip strip
technology in the present invention has advantages as follows:
[0023] 1. Control of the transition point of the airflow around the
club perimeter from laminar to turbulent flow.
[0024] 2. Reduction in lateral side forces caused by varying
airflow transitions while club is undergoing changes in
angle-of-attack and being subjected to non-uniform wind velocity
profiles.
[0025] 3. Reduction in asymmetrical cavitation behind the club head
during a swing due to more uniform transition to turbulent flow
around club head.
[0026] 4. Increased ability of golfers to maintain their intended
swing path and club head rotation through reduction of
uncontrollable and unpredictable lateral forces.
[0027] 5. Increased likelihood of golfer to hit center of
percussion, the sweet spot, on club head face with desired club
head incidence.
[0028] 6. Improved golf driver accuracy and distance off the tee
and off the fairway due to golfer hitting sweet spot more often
with intended club head alignment.
[0029] 7. Applicability of trip strip technology to existing golf
clubs through retrofitting clubs with an adhesive, elastic, or
other disturbance.
[0030] While the preferred embodiments of the invention have been
described above, it will be recognized and understood that various
modifications may be made therein and the appended claims are
intended to cover all such modifications which may fall within the
spirit and scope of the invention.
* * * * *