U.S. patent number 3,824,710 [Application Number 05/395,927] was granted by the patent office on 1974-07-23 for friction-type swivel shoe.
This patent grant is currently assigned to Wolverine World Wide, Inc.. Invention is credited to Robert B. Egtvedt.
United States Patent |
3,824,710 |
Egtvedt |
July 23, 1974 |
FRICTION-TYPE SWIVEL SHOE
Abstract
The ball of an athletic shoe sole includes a rotating swivel
with a configurated surface engaging bottom. The swivel is
integrally molded within the sole of the shoe with a lubricating
film positioned between the shoe sole and swivel. The generally
circular swivel includes an upwardly and outwardly extending
central holding member and a peripheral outwardly extending
shoulder for securing the swivel within the shoe sole. A
reinforcing ring is integrally molded in the shoe sole and extends
around the periphery of the frictional member below the peripheral
shoulder to prevent the deflection of the sole material away from
the area adjacent the swivel.
Inventors: |
Egtvedt; Robert B. (Comstock
Park, MI) |
Assignee: |
Wolverine World Wide, Inc.
(Rockford, MI)
|
Family
ID: |
23565117 |
Appl.
No.: |
05/395,927 |
Filed: |
September 10, 1973 |
Current U.S.
Class: |
36/115;
36/132 |
Current CPC
Class: |
A43B
3/0042 (20130101); A43B 5/10 (20130101) |
Current International
Class: |
A43B
5/00 (20060101); A43B 5/10 (20060101); A43b () |
Field of
Search: |
;36/2.5R,2.5AE,2.5A,8.3,59R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lawson; Patrick D.
Attorney, Agent or Firm: Price, Heneveld, Huizenga &
Cooper
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows.
1. An athletic shoe sole comprising:
a disc-like swivel member having a configurated bottom surface and
at least one shoulder extending outwardly from an upper surface
thereof;
a lubricious coating over said upper surface of said swivel;
and
a sole of moldable material molded around said swivel and said
shoulder to capture said swivel within said sole whereby said
lubricious coating permits rotation of said swivel with respect to
said sole.
2. The shoe sole as defined in claim 1 wherein said swivel
comprises a disc-like member and said one shoulder extends
outwardly around the outer periphery thereof.
3. The shoe sole as defined in claim 2 and further including an
upwardly and outwardly projecting member extending centrally from
said swivel defining a second shoulder.
4. The shoe sole as defined in claim 3 wherein said configurated
bottom surface of said swivel extends below the bottom of said shoe
sole and includes a plurality of dimples.
5. The shoe sole as defined in claim 4 wherein said configurated
bottom surface of said swivel further includes a first annular band
formed around the outer periphery thereof.
6. The shoe sole as defined in claim 5 wherein said configurated
bottom surface of said swivel further includes a second annular
band of lesser diameter than said first band.
7. The shoe sole as defined in claim 6 wherein said configurated
bottom surface of said swivel includes a concave recess formed
within said second band.
8. The shoe sole as defined in claim 1 and further including a
second lubricious coating over said first mentioned coating.
9. The shoe sole as defined in claim 1 and further including a
circular reinforcing member embedded in said sole and
circumscribing said swivel below said shoulder.
10. An athletic shoe sole including a frictional type swivel
comprising:
a disc-shaped swivel member including first and second horizontally
spaced circular shoulders extending outwardly from an upper surface
thereof, and a configurated bottom surface;
means for lubricating said upper surface of said swivel member;
and
a shoe sole molded around said shoulders of said swivel member.
11. The shoe sole as defined in claim 10 wherein one of said
shoulders extends around the outer periphery of said swivel
member.
12. The shoe sole as defined in claim 11 and further including a
ring embedded in said sole circumscribing said swivel under said
one shoulder.
13. The shoe sole as defined in claim 12 wherein said ring includes
a plurality of spaced apertures extending therethrough.
14. The shoe sole as defined in claim 10 wherein said lubricating
means comprises at least one lubricious coating applied to said
upper surface of said swivel member.
15. The shoe sole as defined in claim 10 wherein said lubricating
means comprises a first lubricating film on said upper surface of
said swivel member, and a second lubricating film in engagement
with said first film.
Description
BACKGROUND OF THE INVENTION
The present application relates to an athletic shoe having a
rotatable swivel molded within the sole of the shoe.
Frequently in sporting events such as tennis, it is necessary for
the contender to pivot about the ball of his foot. Typically,
tennis shoes are designed for maximum frictional engagement with
the surface of the tennis court thereby somewhat inhibiting
pivoting as is frequently necessary during the game. Although
pivotal friction engaging type of rotating devices have been
proposed which strap onto the bottom of a shoe or are otherwise
secured to the bottom of a shoe as a separate attachment, such
devices have limited application to activities such as dancing and
are not designed for nor would they successfully withstand the
stresses frequently encountered, for example, during a game of
tennis. U.S. Pat. Nos. 2,671,971 issued Mar. 14, 1954 to D. J.
Garretson and 3,081,562 issued Mar. 19, 1963 to J. Oakley are
representative of such prior art devices. Also, such devices extend
considerably from the shoe, are bulky and would severely impair the
motion of a user engaged in an athletic event.
Although several cleat type swivels have been proposed, such
devices are of a structure unsuitable for shoes employed for use in
playing racket sports such as tennis, squash or other sports such
as handball or paddleball played on courts where cleats cannot be
employed and where a frictional surface engaging shoe sole is
required.
SUMMARY OF THE INVENTION
The present invention, however, provides a unique swivel of
simplified construction and which can be positioned within a shoe
sole during the molding of the shoe sole for holding the device
integrally within the sole and provide a pivotal frictional pad for
engaging a floor surface such as a tennis court. Apparatus
embodying the present invention comprises a swivel disc having
vertically and horizontally spaced peripheral shoulders for
securing the disc within a shoe sole integrally molded therearound.
A lubricating film is provided between the disc and the shoe sole
to permit relative rotation therebetween. In some embodiments, a
reinforcement ring is positioned in the shoe sole around the
periphery of the lowermost of the peripheral shoulders to prevent
deflection of the shoe sole away from the disc. The swivel disc
extends slightly below the bottom surface of the shoe sole to
engage the playing surface without obstructing non-pivotal movement
of the shoe along the surface of the floor.
It is an object of the present invention, therefore, to provide an
improved frictional type swivel for athletic shoes.
Another object of the present invention is to provide a
substantially unitary swivel construction to be integrally molded
within a shoe sole.
Still a further object of the present invention is to provide a
swivel disc for a shoe and which has a configurated bottom for
frictionally engaging a relatively smooth surface.
Yet a further object of the present invention is to provide a
frictional swivel with improved means for securing the swivel
within a shoe sole.
These and other objects of the present invention will become
apparent upon reading the following description thereof together
with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a bottom plan view of a shoe embodying the present
invention;
FIG. 2 is a greatly enlarged cross-sectional view of one-half of
the frictional swivel during molding in the shoe sole;
FIG. 3 is a top plan view of the frictional swivel shown in FIG.
1;
FIG. 4 is a perspective view of the upper and lower mold halves for
manufacturing the frictional swivel;
FIG. 5 is a greatly enlarged view of one-half of the frictional
swivel as it appears in the mold of FIG. 4 during the molding step;
and
FIG. 6 is an enlarged fragmentary plan view of a segment of the
reinforcing ring shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a shoe 10 having a sole 12
with a bottom surface 13. Fitted within the sole of the shoe, as
seen in FIG. 1, is a frictional swivel device 20 which permits
relative rotation between the device and the shoe as indicated by
arrow A in FIG. 1.
As best seen in FIGS. 1, 2 and 3, the frictional swivel device
comprises a substantially pancake- or disc-shaped member molded of
a resilient polymeric material such as polyvinyl chloride,
polyurethane or the like or of a rubber material such as butadiene,
neoprene or the like with a durometer hardness ranging from about
45-80. A rubber having a durometer of 60 is employed in the
preferred embodiment for the desired wearability. FIG. 2 shows
one-half of the swivel and shoe sole during manufacturing which is
symmetrical about axis B so that only one side of the structure
need be shown to understand its construction. The swivel has a
centrally positioned upstanding holding member 22 defining a
peripheral flange or shoulder 23 of circular configuration and
which tapers inwardly to a necked down portion 24 as best seen in
FIG. 2.
The upper surface 25 of the swivel tapers upwardly and outwardly,
as best seen in FIG. 2, to a peripheral flange or shoulder 26.
Shoulder 26 is spaced slightly below shoulder 23 and substantially
outwardly from shoulder 23. The body of swivel 20 is necked down
below shoulder 26 and terminates at the outer edge 28 in an annular
reinforcing band 29 with a substantially flat bottom surface and a
rectangular cross section as seen in FIG. 2.
Band 29, as best seen in FIG. 1, extends around the outer periphery
of the bottom surface of the frictional swivel and reinforces the
swivel to prevent its deflection due to applied stresses during use
of the shoe.
The bottom of the swivel within reinforcing band 29 is configurated
to provide an optimal floor or court surface engaging surface. In
the preferred embodiment, the bottom of swivel 20 comprises a
plurality of generally hemispherical dimples 30 as seen in FIGS. 1
and 2. The dimples are approximately 5/32 inch in diameter and
arranged in a substantially uniform pattern with a density covering
approximately 50 percent of the annular surface area in which they
are located. Although dimples are employed in the preferred
embodiment and are believed to provide optimal frictional
engagement between the swivel and the floor surface during both
lineal movement of the shoe and for pivoting, other configurated
surfaces for the bottom of swivel 20 may be employed with some loss
in the desired effect.
Around the center of the bottom surface of the frictional swivel
there is formed a second annular support band 32 having a diameter
substantially smaller than band 29 and having a flat annular
surface 33. A concave indentation 34 is centrally formed within
band 29 at the center of the bottom of the frictional swivel and
distributes the weight at a ball of the foot over a larger area
instead of concentrating it directly upwardly. The bottom surfaces
of bands 29 and 32 and the lowermost tips of dimples 30 lie in a
common plane extending slightly beyond the bottom surface 13 of the
shoe sole as seen in FIG. 2. The extension is, however,
sufficiently slight so that while although securely gripping the
floor or other surface, it does not cause the user to stumble due
to lateral forces against the peripheral edge 28 of the swivel.
The swivel is molded in a mold 40 as seen in FIG. 4. Mold 40
includes an upper single piece segment 41 with a configurated
member 42 for forming the dimples in the bottom surface of the
frictional swivel and a two piece lower section 44. Mold section 44
includes left and right halves defining a generally circular
configurated recess 45 therein for defining the shoulders of the
swivel. The two halves of section 44 permit removal of the swivel
from the mold as is necessitated by shoulders 23 and 26. Mold 40
includes conventional injection ports and means for locking the
sections together.
With the mold in its closed and locked position, as seen in the
half sectional view shown in FIG. 5, the polymeric material is
injected into the mold and forms the swivel including a flash skirt
35 extending downwardly and around the periphery of the swivel.
Skirt 35 accommodates for shrinkage of the material during cooling
and is subsequently trimmed off, forming edge 28, before the
molding of the swivel into the shoe as now discussed.
As seen in FIG. 2, once the frictional swivel has been molded and
the flash removed, it is positioned on a platform 50 forming a mold
insert for a conventional shoe sole mold employed for molding the
soles of the tennis shoe to the uppers. The shoe is manufactured
generally by providing a string lasted upper 15 of suitable
leather, cloth, synthetic or other material and having an inner
fabric surface 16. A string 18 is sewn around the end of the upper
material holding the upper in position during the sole molding
step. An innersole 18' is positioned over the inside surface of
sole 12. The sole is, like the frictional swivel, manufactured of a
suitable polymeric material such as rubber or other polymers.
The mold insert platform 50 includes a plurality of upstanding pins
52 spaced in a circle having a diameter somewhat larger than the
diameter of the necked down portion 27 of the frictional pivot.
Each pin 52 has a shoulder portion 53 directed inwardly toward the
frictional swivel. A flat annular ring 55 is positioned on the pins
52, as seen in FIG. 2, and extends around the swivel to reinforce
the sole. As best seen in FIG. 6, ring 55 includes a plurality of
elongated apertures 57 centrally spaced along the ring at
10.degree. intervals. These apertures permit the sole material to
securely anchor the ring within the sole by surrounding the ring
and filling the apertures as seen in FIG. 2. In the preferred
embodiment, ring 55 was stamped from 410 type stainless steel
approximately 0.015 inches thick and was approximately 0.25 inches
wide.
In order to secure the swivel in place during the molding step, a
foot form 11 is positioned within the shoe against the insole 18'
as seen in FIG. 2. Foot form 11 includes a plurality of spaced
downwardly depending dowels 17', each including a pin 19 inserted
therein for piercing into the body of the swivel disc through the
top surface thereof. The pins securely hold the disc during molding
of the sole around the swivel and when foot form 11 is removed, the
resultant pierce holes are sufficiently small so they do not reduce
the structural strength of the swivel or sole and do not interfere
with its rotation.
To facilitate rotation of the swivel, lubricious films are applied
to the upper surfaces of the swivel prior to insertion into the
shoe sole mold. In the preferred embodiment, a first lubricious
film 60 of Teflon is sprayed over the upper surfaces of the swivel
using a commercially available aerosol charged Teflon spray or its
equivalent. A second lubricious film 62 is then applied and
comprises, in the preferred embodiment, a permanent mold release
such as commercially available Korax or its equivalent.
The swivel is then positioned on platform 50, the wire 55
positioned on pins 52 and the shoe upper placed in the conventional
mold (not shown). Next, the pin plate with pins 19 is pressed into
the swivel to secure it in position relative to the shoe upper.
Subsequently, the polymeric shoe sole material is conventionally
injected into the space between foot form 11 and the upper surface
of the second film 62 around the shoulders 23 and 26 and ring 55 as
seen in FIG. 2.
Ring 55, which extends around the periphery of and is vertically
positioned below the lower shoulder 26 of the swivel, prevents the
shoe sole at the inwardly projecting area 17 from deflecting
outwardly thereby securing shoulder 26 within the shoe even under
high stress conditions during use. In some embodiments, however,
this ring may not be necessary or a closed loop of wire or other
circular reinforcing member substituted. The mutually engaging
lubricious films 60 and 62 permit slippage between the frictional
device and the shoe sole at the interface between the two films
which is the interface with the least friction. Although two
applied films are used in the preferred embodiment, in some
embodiments, a single film will suffice to provide the desired
slippage between the swivel and the shoe sole. Also, other
lubricious coatings, sheets or films could be employed. In some
embodiments, thin sheets of Teflon or other lubricious material may
be employed by positioning them over the swivel disc prior to the
sole molding step. Sheets of approximately 0.005 inches thickness
or less will conform to the upper topology of the swivel disc to
provide the desired lubricious interface between the swivel and the
sole.
These and other modifications to the preferred embodiment falling
within the spirit and scope of the present invention as defined by
the appended claims will become apparent to those skilled in the
art.
* * * * *