Means for reducing fatigue from wearing footgear

A sheet piece placed on the insole of a shoe so as to support only the arch portion of the foot. The sheet piece may preferably be used in combination with an insole sheet wherein the sheet piece has a plurality of projections which engage into a plurality of openings formed in the insole sheet. The sheet piece may include first and second pieces attached on opposite surfaces of the insole sheet, wherein the second piece may be attached to the bottom surface of the insole sheet and may be constructed from less expensive material and provided in a plurality for one combination of the insole sheet and the first sheet piece.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to means for reducing fatigue from wearing 
footgear. 
2. Description of the Prior Art 
Relatively expensive footgear such as leather shoes are generally formed to 
have a convex-concave insole surface adapted to complement the 
concave-convex sole of the foot. Nevertheless, since the insole surface of 
leather shoes is generally made of a single leather sheet, the 
concave-convex shape thereof does not sufficiently conform with the sole 
shape of the foot. Particularly, in the arch portion of the foot where the 
convex portion formed in the insole surface of the shoes is not 
sufficiently high enough to neatly conform with the convex shape of the 
arch portion. In more conventional footgear such as slippers or clogs, the 
insole surface is relatively flat and is far from conforming with the 
convex-concave shape of the sole of the foot. The inventor has made 
various experimental studies with regard to fatigue caused by wearing 
footgear and has found that the fatigue from wearing footgear can be 
substantially reduced by applying proper pressure to the arch portion of 
the foot and giving the feeling of contact and moderate rubbing action to 
the arch portion. 
SUMMARY OF THE INVENTION 
Therefore, it is a primary object of the present invention to provide means 
for reducing fatigue from wearing footgear depending upon the 
abovementioned concept. This object is accomplished by placing a sheet 
piece on the insole of footgear so as to support only the arch portion of 
the foot. 
When a sheet piece of the present invention is used with a shoe, the sheet 
piece may conveniently be placed on the insole of a shoe in combination 
with an insole sheet adapted to be placed on the insole of the shoe. 
Therefore, another object of the present invention is to provide a 
combination of an insole sheet and a sheet piece for reducing fatigue from 
wearing footgear. The insole sheet being a synthetic resin sheet having a 
plurality of regularly arranged openings which open in the upper surface 
thereof at least in a region which corresponds to the arch portion of the 
foot. The sheet piece includes a plurality of regularly arranged 
projections on the lower surface thereof which are adapted to engage with 
said openings wherein said sheet piece is mounted on said insole sheet in 
a manner to support only the arch portion of the foot. By providing a 
sheet piece of the abovementioned structure in combination with an insole 
sheet of the abovementioned structure, fine adjustment with regard to the 
position of mounting the sheet piece relative to the insole of a shoe is 
permitted by altering the engagement between said openings and said 
projections. In this connection, said openings may preferably be provided 
in the entire region of the insole sheet, whereby the insole sheet 
provides an improved ventilation for the sole of the foot and effectively 
protects the sole from sweating. 
Still another object of the present invention is to provide a sheet piece 
for the abovementioned purpose which has a plurality of projections on its 
upper surface in order to improve the feeling which the sheet piece gives 
to the arch portion of the foot. By this arrangement, a pleasant feeling 
of contact and rubbing action are applied to the arch portion of the foot 
resulting in a reduction of fatigue due to wearing the footgear. 
The thickness of the sheet piece which supports the arch portion of the 
foot in a manner to apply a pressure thereto should vary in accordance 
with persons who use the sheet piece because the degree of concavity in 
the arch portion of the foot varies according to the person. However, it 
is impractical to prepare a plurality of sheet pieces having different 
thickness when the sheet piece is supplied in combination with an insole 
sheet with which it engages. Therefore, it is still another object of the 
present invention to provide a combination of an insole sheet and first 
and second sheet pieces for reducing fatigue from wearing footgear, said 
insole sheet being a synthetic resin sheet having a first group of 
regularly arranged openings which open in at least the upper surface 
thereof and a second group of regularly arranged openings which open in at 
least the lower surface thereof. The first and second groups of openings 
are positioned at least in a region which corresponds to the arch portion 
of the foot. The first sheet piece includes a plurality of regularly 
arranged projections on the lower surface thereof which are adapted to 
engage with said first group of openings. The second sheet piece including 
a plurality of regularly arranged projections on the upper surface thereof 
which are adapted to engage said second group of openings. Wherein, said 
first and second sheet pieces are mounted to said insole sheet in a manner 
to support only the arch portion of the foot. In this combination, the 
pressure applied to the arch portion of the foot is determined by the sum 
of the thickness of the first and second sheet pieces and the pressure can 
conveniently be adjusted by varying the thickness of said second sheet 
piece. The second sheet piece may be made as a smaller, thinner and less 
expensive sheet piece. Therefore, by supplying several pieces of different 
thicknesses of said second sheet piece for one combination of said first 
sheet piece and the insole sheet, the user can readily obtain a most 
suitable height for the convex portion in the sole which applies pressure 
to the arch portion of the foot as a result of selecting the proper 
thickness. 
Other objects and further scope of applicability of the present invention 
will become apparent from the detailed description given hereinafter; it 
should be understood, however, that the detailed description and specific 
examples, while indicating preferred embodiments of the invention, are 
given by way of illustration only, since various changes and modifications 
within the spirit and scope of the invention will become apparent to those 
skilled in the art from this detailed description.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, 1 designates the insole of a shoe to which is attached 
a sheet piece 2 of the present invention at a portion corresponding to the 
arch portion of the foot. In the shown embodiment, the sheet piece 2 has 
projections 3 arranged on the entire surface thereof. As shown in FIG. 2, 
the projections are the highest at a central portion thereof and are 
gradually shortened toward the front and the rear ends of the sheet piece 
as seen in the longitudinal direction of the insole. As shown in FIG. 3, 
the projections are the highest at the outer edge portion of the arch of 
the foot and are gradually shortened toward the other edge of the sheet 
piece as seen in the lateral direction of the insole. The sheet piece 2 
may of course have a smooth surface without the projections 3, although 
the projections provide a more favorable effect in reducing fatique from 
wearing footgear by applying moderate stimulation to the arch portion of 
the foot. Furthermore, the projections provide ventilation spaces between 
the sole of the foot and the sheet piece thereby preventing sweating of 
the foot due to tight contact between the sole and the supporting sheet 
piece. 
The sheet piece of the invention may be attached to the proper portion of 
the insole surface of the shoes, slippers, clogs, etc. by suitable 
adhesive or dual surface adhesive tape. 
FIG. 4 shows another embodiment of the means for reducing fatigue from 
wearing footgear, in combination with an insole sheet. 
In this embodiment, the sheet piece 2 includes a upper surface structure 
that is similar to the piece shown in FIGS. 2 and 3 but further includes 
projections 4 on its lower surface. On the other hand, the insole sheet 6, 
made of a synthetic resin sheet, comprises projections 5 regularly 
arranged on its lower surface and through openings 7 regularly arranged to 
open in the upper and the lower surfaces thereof. The arrangement of the 
projections 4 on the bottom surface of the sheet piece 2 correspond to 
that of the through openings 7 formed in the insole sheet 6. Thus by 
engaging the projections 4 into the openings 7, the sheet piece 2 is 
readily mounted to the insole sheet 6 in a suitable region of the sole 
sheet so that the sheet piece 2 provides the necessary support to the arch 
portion of the foot wearing the shoe in which the combination of the sole 
sheet 6 and the sheet piece 2 is inserted. 
FIGS. 5 and 6 show another combination of the insole sheet and the sheet 
piece for reducing fatigue from wearing footgear. The combination 
generally designated by 11 comprises an insole sheet 12, a first sheet 
piece 13 attached to the upper surface of the insole piece at a portion 
corresponding to the arch portion of the foot and a second sheet piece 14 
attached to the bottom surface of the insole sheet similarly at a portion 
corresponding to the arch portion of the foot. The insole sheet 13 is 
formed with a first group of regularly arranged through openings 15 which 
traverse the thickness of the insole sheet as shown in FIGS. 7 and 8. 
Furthermore, the insole sheet has a plurality of regularly arranged short 
tubular projections 16 on the bottom surface thereof, said tubular 
projections defining a second group of regularly arranged openings 17. 
As shown in FIG. 9, the first piece 13 has on its upper surface, a first 
group of projections 18 for simulating the arch portion of the foot and it 
also has on the bottom surface thereof a second group of projections 19 
which engage with said first group of openings 15 in the insole sheet 12. 
By the projections 19 engaged into the openings 15, the sheet piece 13 is 
readily mounted to the upper surface of the insole sheet 12. 
As shown in FIG. 10, the second sheet piece 14 has a plurality of 
projections 20 on its upper surface, said projections 20 being engagable 
into said second group of openings 17 provided by the tubular projections 
16 formed on the bottom surface of the insole sheet 12. By the projections 
20 being engaged into the openings 17, the second sheet piece 14 is also 
readily mounted to the bottom surface of the insole sheet 12. 
Commercially, the first sheet piece 13 may be supplied as a single piece 
while, by contrast, said second sheet piece 14 should preferably be 
supplied as a set containing several kinds of pieces. For example, a first 
piece of the set may have a medium thickness to provide in cooperation 
with the single sheet piece 13 a convex means of a medium or average 
height for applying pressure to the arch portion of the foot; a second 
piece may be a little thicker to provide a higher convex means and a third 
piece may be a little thinner to provide a lower convex means. Of course, 
more than three pieces may be supplied as a set to provide a more 
gradually stepped variance in the height of the convex means to apply 
pressure to the arch portion of the foot. 
Thus, in accordance with this embodiment, the present invention is able to 
provide a universal combination composed of a single insole sheet 12, a 
single first sheet piece 13 and several pieces of less expensive second 
sheet pieces 14 (of course the combinations are supplied as pairs 
including a pair of insole sheets, etc). Thus, every individual's personal 
preference for the height of the convex means for applying pressure to the 
arch portion of the foot may be achieved by a simple selection from 
several inexpensive small pieces which do not incur any substantial 
increase in cost when compared with the total cost of the combination. 
Although the invention has been shown and described with respect to some 
preferred embodiments thereof, it should be understood by those skilled in 
the art that various changes and omissions in the form and detail thereof 
may be made therein without departing from the spirit and the scope of the 
invention.