U.S. patent application number 12/154562 was filed with the patent office on 2009-11-26 for wind-stabilized baseball cap.
Invention is credited to Thomas H. Greene, JR..
Application Number | 20090288238 12/154562 |
Document ID | / |
Family ID | 41340998 |
Filed Date | 2009-11-26 |
United States Patent
Application |
20090288238 |
Kind Code |
A1 |
Greene, JR.; Thomas H. |
November 26, 2009 |
Wind-stabilized baseball cap
Abstract
A baseball cap including features for stabilizing the cap in a
moving stream of air. The cap includes a modified bill having a
downforce generator configured to create a relatively stagnate
recirculation zone between the downforce generator and the head
covering. This recirculation zone tends to negate the lifting
effect found in prior art bills. The invention preferably also
includes a vent through the bill. The vent is located behind the
downforce generator, so as to connect the underside of the bill to
the recirculation zone formed in the wake of the downforce
generator. The vent is selectively closed by a flexible flap. The
flap remains closed to prevent rain from passing through the vent.
However, if pressure beneath the bill significantly exceeds
pressure above the bill, the vent opens to equalize the pressure.
This action prevents the creation of a net lifting force which
might lift the cap off the wearer's head.
Inventors: |
Greene, JR.; Thomas H.;
(Madison County, FL) |
Correspondence
Address: |
WILEY HORTON
215 SOUTH MONROE STREET, 2ND FLOOR
TALLAHASSEE
FL
32301
US
|
Family ID: |
41340998 |
Appl. No.: |
12/154562 |
Filed: |
May 23, 2008 |
Current U.S.
Class: |
2/171.3 ;
2/175.4; 2/175.5; 2/195.1; 2/195.5 |
Current CPC
Class: |
A42B 1/0182
20210101 |
Class at
Publication: |
2/171.3 ;
2/175.5; 2/175.4; 2/195.5; 2/195.1 |
International
Class: |
A42C 5/04 20060101
A42C005/04; A42B 1/00 20060101 A42B001/00; A42B 1/02 20060101
A42B001/02 |
Claims
1. A baseball cap, comprising: a. a head covering, including a
forward region; b. a bill extending outward from said forward
region of said head covering, said bill having a leading edge
distal to said head covering and a trailing edge proximal to said
head covering; c. a downforce generator, extending upward from said
bill, wherein said downforce generator extends only part of the way
from said leading edge of said bill to said forward region of said
head covering, thereby creating a gap between said downforce
generator and said forward region of said head covering; and d. a
vent, extending through said bill into said gap.
2. A baseball cap as recited in claim 1, further comprising a
flexible flap covering said vent.
3. A baseball cap as recited in claim 2, wherein: a. said flexible
flap has a leading edge and a trailing edge; b. said leading edge
of said flexible flap is secured to said bill; and c. said trailing
edge of said flexible flap is free.
4. A baseball cap as recited in claim 1, wherein: a. said downforce
generator has a middle portion, a first side extreme, and a second
side extreme; b. said downforce generator has a splitter located in
said middle portion, with said splitter being configured to divide
said air flow into a first portion directed toward said first side
extreme and a second portion directed toward said second side
extreme.
5. A baseball cap as recited in claim 2, wherein: a. said downforce
generator has a middle portion, a first side extreme, and a second
side extreme; and b. said downforce generator has a splitter
located in said middle portion, with said splitter being configured
to divide said air flow into a first portion directed toward said
first side extreme and a second portion directed toward said second
side extreme.
6. A baseball cap as recited in claim 3, wherein: a. said downforce
generator has a middle portion, a first side extreme, and a second
side extreme; b. said downforce generator has a splitter located in
said middle portion, with said splitter being configured to divide
said air flow into a first portion directed toward said first side
extreme and a second portion directed toward said second side
extreme.
7. A baseball cap as recited in claim 1, wherein said downforce
generator is a thin structure attached along said leading edge of
said bill, thereby forming a cavity between said downforce
generator and said bill.
8. A baseball cap as recited in claim 2, wherein said downforce
generator is a thin structure attached along said leading edge of
said bill, thereby forming a cavity between said downforce
generator and said bill.
9. A baseball cap as recited in claim 3, wherein said downforce
generator is a thin structure attached along said leading edge of
said bill, thereby forming a cavity between said downforce
generator and said bill.
10. A baseball cap as recited in claim 4, wherein said downforce
generator is a thin structure attached along said leading edge of
said bill, thereby forming a cavity between said downforce
generator and said bill.
11. A baseball cap as recited in claim 7, further comprising a
drain passing through said downforce generator, thereby draining
said cavity.
12. A baseball cap as recited in claim 7, further comprising a
drain passing through said bill, thereby draining said cavity.
13. A baseball cap, comprising: a. a head covering, including a
forward region; b. a bill extending outward from said forward
region of said head covering, said bill having a leading edge
distal to said head covering and a trailing edge proximal to said
head covering; c. a downforce generator, assuming the form of an
inclined wall sloping upward and rearward from said leading edge of
said bill and being attached thereto; d. wherein said inclined wall
extends only part of the way from said leading edge of said bill to
said forward region of said head covering, thereby creating a gap
between said downforce generator and said forward region of said
head covering; and e. a vent, extending through said bill into said
gap.
14. A baseball cap as recited in claim 13, further comprising a
flexible flap covering said vent.
15. A baseball cap as recited in claim 14, wherein: a. said
flexible flap has a leading edge and a trailing edge; b. said
leading edge of said flexible flap is secured to said bill; and c.
said trailing edge of said flexible flap is free.
16. A baseball cap as recited in claim 13, wherein: a. said
downforce generator has a middle portion, a first side extreme, and
a second side extreme; and b. said downforce generator has a
splitter located in said middle portion, with said splitter being
configured to divide said air flow into a first portion directed
toward said first side extreme and a second portion directed toward
said second side extreme.
17. A baseball cap as recited in claim 13, wherein said downforce
generator is a thin structure attached along said leading edge of
said bill, thereby forming a cavity between said downforce
generator and said bill.
18. A baseball cap as recited in claim 14, wherein said downforce
generator is a thin structure attached along said leading edge of
said bill, thereby forming a cavity between said downforce
generator and said bill.
19. A baseball cap as recited in claim 13, further comprising a
drain passing through said downforce generator, thereby draining
said cavity.
20. A baseball cap as recited in claim 13, further comprising a
drain passing through said bill, thereby draining said cavity.
Description
MICROFICHE APPENDIX
[0001] Not Applicable
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to the field of headwear. More
specifically, the invention comprises a baseball cap having a
modified bill configured to produce downforce when the cap is
placed in a moving airstream.
[0004] 2. Description of the Related Art
[0005] The "baseball cap" is one of the world's best known hats.
FIG. 1 shows a typical example. Baseball cap 10 is comprised of
head covering 12 and bill 14. Head covering 12 is a generally
circular assembly of flexible material sized to fit fairly closely
over the human head. Bill 14 has leading edge 52 and trailing edge
54. The trailing edge is attached to the forward portion of the
head covering. As the hat is normally worn, the bill extends
forward from the wearer's face. The bill provides shade and weather
protection for the user's face.
[0006] Those familiar with the art will know that such hats are
made using a variety of technique. The example of FIG. 1 is
constructed using a sewn assembly of wedge-shaped pieces. These are
curved inward and join at the top, where a button is usually
affixed. Such hats must typically include size-adjusting features.
The rear of the hat may have a break spanned by an adjustable
strap. The strap is used to adjust the circumference of the hat at
its largest section. Alternatively, the head covering may include
elastic material which eliminates the need for other adjustment
features.
[0007] FIG. 2 shows an elevation view of a person actually wearing
a prior art baseball cap. Such caps are often worn while traveling
in an open vehicle--such as a fishing boat. Air flow directed
toward the wearer's face has a tendency to lift the baseball cap
off the wearer's head. As for most situations involving subsonic
compressible flow, the phenomenon is explained by the application
of Bernoulli's equation, which can be written as:
1 / 2 v 1 2 + gh 1 + P 1 .rho. 1 = 1 / 2 v 2 2 + gh 2 + P 2 .rho. 2
##EQU00001##
In this expression, v stands for the flow velocity at a given
point, g stands for gravitational acceleration, h stands for the
height above a reference plane, P stands for the pressure of the
air at a given point, and .rho. stands for the density of the air
at a given point.
[0008] From this equation one may easily discern the fact that when
a compressible fluid is flowing past an object at subsonic speeds,
the faster the flow is in a particular region the lower the
pressure will be in that region. When looking at FIG. 2, the reader
will observe how the flow must split to flow over the top and
bottom of bill 14. The flow over the top passes smoothly over the
head covering and is not decelerated very much. This is denoted in
the view as high velocity region 18.
[0009] The flow passing under the bill, however, impacts the
wearer's face 16. This produces a recirculation area denoted as
stagnation region 20. The flow in this area is relatively slow.
Thus, from Bernoulli's equation, one may accurately predict that
the air pressure in the area beneath the bill will be greater than
the air pressure in the area above the bill. The result is the
creation of lift 24, which tends to lift the cap free of the
wearer's head.
[0010] Prior hat designers have accounted for this phenomenon by
angling the bill downward as shown. The downward angle has the
effect of an airfoil having a negative angle of attack. The flow
over the top therefore creates downforce 22. If the magnitude of
downforce 22 exceeds that of lift 24, then the hat will stay on. Of
course, the motion of the wearer's head alters the bill's angle of
attack. If the user inclines her head slightly, downforce 22 will
be greatly reduced. This will likely be the instant when the moving
airstream lifts the cap free of the wearer's head and carries it
away.
[0011] The loss of such a cap is a significant inconvenience. This
is particularly true in a boating situation, where the hat is
likely to blow overboard and be lost. Prior art designers have
attempted to remedy this known problem in a variety of ways. For
example, some caps have incorporated a bill having a hinged vent
flap. The vent flap pivots upward if the pressure difference
between the region beneath the bill and above the bill becomes
large enough. Other designs have incorporated one or more fixed
vents through the bill. Still other designs have incorporated a
bill with a severe downward angle, so that the bill's angle of
attack remains negative throughout the range of motion of the
user's head.
[0012] While these prior art designs have in part remedied the
problem, no prior art design has produced a good solution while
still maintaining the conventional benefits of the traditional
baseball cap. The present invention seeks to remedy these
shortcomings.
BRIEF SUMMARY OF THE PRESENT INVENTION
[0013] The present invention is a baseball cap including features
for stabilizing the cap in a moving stream of air. The cap includes
a modified bill having a downforce generator configured to create a
relatively stagnate recirculation zone between the downforce
generator and the head covering. This recirculation zone tends to
negate the lifting effect found in prior art bills.
[0014] The invention preferably also includes a vent through the
bill. The vent is located behind the downforce generator, so as to
connect the underside of the bill to the recirculation zone formed
in the wake of the downforce generator. The vent is selectively
closed by a flexible flap. The flap remains closed to prevent rain
from passing through the vent. However, if pressure beneath the
bill significantly exceeds pressure above the bill, the vent opens
to equalize the pressure. This action prevents the creation of a
net lifting force which might lift the cap off the wearer's
head.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] FIG. 1 is a perspective view, showing a prior art baseball
cap.
[0016] FIG. 2 is a side elevation view, showing the flow of air
over a prior art baseball cap.
[0017] FIG. 3 is a perspective view, showing the present
invention.
[0018] FIG. 4 is an exploded perspective view, showing the various
components of the present invention.
[0019] FIG. 5 is a detail view, showing the operation of the
downforce generator and the vent.
[0020] FIG. 6 is a detail view, showing the operation of the
downforce generator and the vent.
[0021] FIG. 7 is a perspective view, showing the present invention
with the downforce generator removed.
[0022] FIG. 8 is a side elevation view, showing an alternate
embodiment.
REFERENCE NUMERALS IN THE DRAWINGS
TABLE-US-00001 [0023] 10 baseball cap 12 head covering 14 bill 16
face 18 high velocity region 20 stagnation region 22 downforce 24
lift 26 stay-on cap 28 modified bill 30 downforce generator 32
splitter 34 vent 36 flap 38 drain 40 upper pressure 42 lower
pressure 44 flap attachment 46 free end 48 secondary downforce 50
forward region 52 leading edge 54 trailing edge 56 gap 58 cavity 60
first lateral extreme 62 second lateral extreme
DETAILED DESCRIPTION OF THE INVENTION
[0024] FIG. 3 shows the present invention in an assembled state.
Stay-on cap 26 has modified bill 28. Downforce generator 30 is
preferably attached t modified bill 28. The reader will observe how
the downforce generator preferably assumes a form reminiscent of a
snow plow blade. Splitter 32 lies near the middle of the downforce
generator. Air flow impacting the downforce generator strikes the
splitter and is thereafter divided into a first portion directed
toward a first lateral extreme 60 and a second portion directed
toward a second lateral extreme 62.
[0025] FIG. 4 shows the same assembly in an exploded state.
Modified bill 28 has vent 34 passing through it from top to bottom.
This vent is preferably covered by flap 36. Downforce generator 30
then lies generally over the location of the flap.
[0026] FIG. 5 shows a section elevation view through modified bill
28 in the region of vent 34. The reader will observe that downforce
generator 30 is a thin-walled structure rising upward and rearward
from the leading edge of modified bill 28. Cavity 58 is formed by
downforce generator 30 and modified bill 28. The reader will
observe that the downforce generator extends only part of the way
from the leading edge of modified bill 28 to forward region 50 of
head covering 12. Thus, gap 56 is formed between the trailing edge
of the downforce generator and forward region 50.
[0027] The presence of gap 56 creates a recirculation zone behind
the trailing edge of the downforce generator. The airstream
impacting the upwardly inclined forward surface of the downforce
generator creates downforce 22 (through stagnation pressure of the
air impacting the device). Downforce 22 obviously tends to hold the
hat down on the user's head. The creation of the recirculation zone
in gap 56 tends to create relatively high pressure in this region,
which places secondary downforce 48 on the upper surface of flap
36.
[0028] Flap 36 is made of a flexible material. It is attached to
the bill by flap attachment 44 (which can be a sewn joint, an
adhesive joint, etc.). The effect of this construction is that the
leading edge of flap 36 remains in a fixed position with respect to
the bill, but free end 46 can lift upward, thereby opening vent 34
and allowing flow to occur from below the bill to above the
bill.
[0029] In the configuration shown in FIG. 5, upper pressure 40 (the
air pressure above the bill) exceeds lower pressure 42 (the air
pressure below the bill). Thus, secondary downforce 48 exceeds lift
24 and flap 36 remains closed. This represents the normal
configuration. In this configuration, the hat functions as a normal
baseball cap in that it does not allow sun or rain to reach the
wearer's face. Free end 46 is preferably designed to rest flat
against forward region 50 or the bill itself, so that rain falling
down the vertical portions of the cap will not leak through vent
34. FIG. 7 shows a view of flap 36 in the closed position (with the
downforce generator removed for visual clarity).
[0030] In FIG. 6, the flow velocity or flow direction has changed
so that the pressure below the vent exceeds the pressure above it.
In that case flap 36 opens as shown. Air then flows from beneath
the bill and into gap 56, where it then joins the stream passing
over the top of the cap. This results in a significant reduction in
lifting force. Meanwhile, the air flowing over the downforce
generator continues to produce downforce 22. Those skilled in the
art will therefore realize that by appropriately sizing and shaping
the elements disclosed, it is possible for downforce 22 to exceed
the lifting force in nearly all configurations. Thus, the cap has a
much greater tendency to stay on the wearer's head.
[0031] The change in flow magnitude and direction shown in FIGS. 5
and 6 can be the result of various causes. Some examples are an
increase in vehicle speed, a sudden wind gust, and the tilting of
the wearer's head. All these things can cause a prior art hat to
lift off the wearer's head.
[0032] Returning now to FIG. 5, some addition features of the
invention will be discussed. The reader will observe that downforce
generator 30 is preferably a thin walled structure. It is
preferably attached near the bill's leading edge. This fact creates
cavity 58 between the bill and the downforce generator. Depending
on the configuration of the bill, this cavity may trap rainwater.
Thus, in some embodiments a drain is desirable. Turning now to FIG.
3, the reader will note the inclusion of three drains 38 through
the downforce generator. These allow rain flowing off the head
covering and bill to escape cavity 58.
[0033] FIG. 8 shows an alternate location for the drain. In this
embodiment, drain 38 passes through the bill. The drain can be
placed in any convenient location, so long as it allows water
collecting in cavity 58 to exit.
[0034] Although the preceding description contains significant
detail, it should not be construed as limiting the scope of the
invention but rather as providing illustrations of the preferred
embodiments of the invention. As an example, although the invention
has been illustrated with a thin walled downforce generator, a
solid or thick-walled design made of lightweight foam material
could be substituted. Many other variations will be apparent to
those skilled in the art. Thus, the scope of the invention should
be fixed by the following claims rather than any specific examples
provided.
* * * * *