Note: Descriptions are shown in the official language in which they were submitted.
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SAFETY BOOT TOE CAP CONSTRUCTION
BACKGROUND OF THE INVENTION
This invention relates to new and useful improve-
ments in the manufacture, by mass production techniques, of
safety boots and shoes and although the term "boot" is used
throughout the specification and claims, nevertheless it
will be appreciated that it includes shoes also.
Conventionally, safety boots are classified accord-
ing to the resistance of the steel box toe to an impact load
measured in foot pounds. For example, a light duty safety
boot will withstand an impact load of 35 foot pounds without
distorting beyond a predetermined amount, a medium duty box
toe will withstand 50 foot pounds, a heavy duty box toe will
withstand 75 foot pounds, and an extra heavy box toe will
withstand in excess of 100 foot pounds impact, all of which
without distorting beyond a predetermined amount.
In order to produce extra heavy duty safety boots,
a steel box toe must be used with a relatively wide inturned
base flange in order to give sufficient rigidity to withstand
the test impact. Unfortunately, the use of such box toes in-
terferes with machine sewing and mass product manufacturing
techniques.
While it is quite possible to produce an extra heavy
box toe construction by the use of cemented or vulcanized
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boot assembly, nevertheless this is not always satisfactory
and acceptable to the workman using such a boot.
By far the most preferred type of construction
is what is known as a "goodyear welt" construction which
not only enables a boot to be produced which is sealed
against the ingress of moisture and other contaminants
while in use, but also permits the use of relatively thick
rubber outsoles which provide more comfort to the end user,
it being understood that such safety boots are often rela-
tively heavy due to the construction thereof.
Unfortunately, the box toe construction with the
inturned flange is difficult to use with a welted construc-
tion unless hand sewing of the toe area is undertaken. With
a goodyear welt, a horizontal stitch line is required pass-
ing through the welt, through the lower perimeter of the up-
per assembly, and through the sewing strip depending down-
wardly from the underside of the insole.
The use of a heavy duty box toe with the inturned
flange makes it extremely difficult to form this sewing line
around the toe area, by conventional machinery as the needle
often strikes the lower perimeter of the steel box causing
the needle to break and slowing down the manufacture of this
particular aspect of the safety boot.
Attempts have been made to solve this problem and
reference should be made to prior art illustrating these
attempts. For example, U.S. Patent 3986279 shows a heavy
duty box toe but only in a non-welted construction so that
the problem does not really arise.
U.S. Patent 2438016 attempts to solve the problem
by utilizing an insertable toe plug cemented in place thus
taking the place of a welt around the toe area and U.S.
Patent 4011667 utilizes a compromise box toe construction
in which the flange is only vestigial, being formed on the
box toe and incorporating a steel stress absorbing plate
in the construction.
As mentioned previously, in so called cemented .
or vulcanized shoes, no particular problem is presented
since it is merely a matter of providing safety toes of
suitable steel alloy, thickness and dimensions and in such
shoes, the safety toe can be produced having a relatively
broad base flange of sufficient width to distribute the
stresses exerted by the steel toe when a blow is exerted
thereon. However, when it is desired to manufacture welt
shoes having cushioned outsoles, a steel toe having a suf-
ficiently broad base flange cannot be incorporated since
the flange interferes with the needle as it forms the in-
seam which joins the overlasted margin of the upper and the
welt, to the aforementioned conventional sewing rib formed
on the undersurface of the insole.
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Another reason for preferring welt shoes is be-
cause of the ease with which they can be re-soled and
cushioned outsoles such as crepe rubber or the like are
preferred since they are more comfortable and less tiring.
SUMMARY OF THE INVENTION
The present invention overcomes these disadvan-
tages and in accordance with the invention there is provi-
ded an insole for safety boot construction comprising an
upper side and a lower side, said lower side including a
substantially vertical, downwardly inclining sewing rib
secured thereto and being spaced inwardly from the edge of
said insole to define a feather around said sewing rib,
said underside being recessed inwardly around the toe area,
as far back as sai~ sewing rib, leaving the upper side pro-
jecting beyond said sewing rib around said toe area.
Another aspect of the invention is to provide an
insole assembly for safety boot construction which comprises
in combination an upper insole member and lower insole mem-
ber laminated to said upper insole member, said lower insole
member including a substantially vertical, downwardly inclin-
ing sewing rib secured to the undersurface thereof and being
spaced inwardly from the edge of said lower insole member for
the major length thereof, to define a feather around said
sewing rib, said lower insole member being trimmed away
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around the toe area thereof whereby said sewing rib extends
around said toe area at the edge of said lower insole mem-
ber, the upper insole member projecting beyond said sewing
rib around the said toe area.
A still further aspect of the invention is to pro-
vide a process for the manufacture of safety boots consist-
ing of the steps of securing an insole assembly to the un-
derside of a last with the insole assembly including an up-
per insole member and a lower insole member laminated to
said insole member, said lower insole member including a
substantially vertical, downwardly inclining sewing rib se-
cured to the undersurface thereof and being spaced inwardly
from the edge of said lower insole member for the major
length thereof, to define a feather around said sewing rib,
said lower insole member being trimmed away around the toe
area thereof, providing an upper including a vamp and a toe
overlying the front part of said vamp, pulling said upper
over the last with the material being brought -lown tightly
to the last, peeling back the toe, inserting a steel box
toe, with a relatively wi.de inturned flang~, between the
vamp and the tce with the flange engaging over the extending
porti.on of the insole assembly, replacing the toe and toe
lasting same, and inserting a ~7elt strip around the perime-
ter of the upper, machine sewing substantially horizontally,
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said welt strip, said upper, said vamp and said sewing
strip and then finishing off the boot in the convention-
al manner.
Another advantage of the invention is to enable
an extra heavy duty safety boot to be constructed with a
welted outsole assembly, utilizing conventional mass pro-
duction techniques.
A still further advantage of the invention is to
provide a safety boot construction with an extra heavy duty
box toe, which is simple in construction, economical in
manufacture and otherwise well suited to the purpose for
which it is designed.
With the foregoing in view, and other advantages
as will become apparent to those skilled in the art to which
this invention relates as this specification proceeds, the
invention is herein described by reference to the accompany-
ing drawings forming a part hereof, which includes a descrip-
tion of the preferred typical embodiment of the principles of
the present invention, in which:
DESCRIPTION OF THE DRAWINGS
Figure 1 is an enlarged fragmentary cross section-
al view of the toe area of a safety boot incorporating the
invention.
Figure 2 is a fragmentary underside view of the
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front portion of an insole assembly utilizing the inven-
tion.
Figure 3 is a cross sectional view along the line
3-3 of Figure 2.
Figure 4 is a cross sectional view along the line
4-4 of Figure 2, but showing the location of the steel box
toe.
Figure 5 is a view similar to Figure 2, but with
the box toe in position.
Figure 6 is an isometric view of a wide flanged
box toe showing the reverse position.
Figure 7 is a fragementary isometric view of the
toe portion of a boot with the toe peeled back for the in-
sertion of the toe box shown in position.
Figure 8 is a fragmentary underside view of the
toe area of a safety boot showing the horizontal stitching
of the welt in position.
In the drawings like characters of reference in-
dicate corresponding parts in the different figures.
DETAILED DESCRIPTION
Proceeding therefore to describe the invention in
detail, reference character 10 illustrates an insole assem-
bly which is normally attached to the underside of the last
(not illustrated) by means of tacks 11 as suggested in Figu-
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re 2.
An upper assembly collectively designated 12 and
shown partially in Figure 7, is then pulled over, side
lasted and heel lasted in the conventional manner. The
upper assembly includes, for the purposes of this invention,
a toe 13 and a vamp 14.
In a goodyear welt construction, to which this
invention relates, a welt strip 15 is incorporated as will
hereinafter be described.
In the manufacture of safety shoes or boots, a
steel box toe collectively designated 16 is incorporated
over the toe area and between the toe and the vamp portions.
The box toe 16 is usually made from hardened steel and is
shaped to engage over the toe cap area and is provided with
relatively wide inturned flange 17 formed upon the underside
thereof when it is desired to produce an extra heavy duty
boot or shoe construction. This flange distributes the
stresses placed upon the box toe under impact.
The insole assembly collectively designated 10 in-
cludes an upper portion or member 18 and a lower portion mem-
ber 19, the two members 18 and 19 being laminated together
by adhesive or other conventional fastening means.
A conventional sewing rib 20 reinforced by canvas
or the like 21, is secured to the upper member 18 as by a
6~
sewing line 22 or the like and this downwardly projecting
sewing rib is normally spaced inwardly from the perimetri-
cal edges 23 and 24 of the two insole members.
However, in the present invention, the portion of
the lower insole member 19, beyond the sewing rib 20 and
normally referred to as the feather, is trimmed away around
the toe area back to the sewing rib 20 as illustrated in
Figures 2 and 4 thus leaving a recessed portion to the in-
sole construction around this toe area, it being understood
that the integrity of the upper insole portion feather is
maintained.
This recess indicated by reference character 25,
receives the inturned flange 17 of the steel box 16 and at
the same time provides sufficient clearance for the horizon-
tal stitch line 26, to be placed by conventional sewing
machinery normally used in the welting operation.
The method of construction is therefore as follows:
Firstly, the double insole assembly 10, hereinbe-
fore described, is tacked to the last with the upper side
down whereupon the upper portion 12 of the boot is pulled
over the last with the leather being brought down tightly
to the last. This includes the vamp and toe piece 13 and
14.
The operator then peels back the toe piece and
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inserts the steel box toe 16 ensuring that the flange 17
engages the recess 25.
The toe cap is then pulled back over the steel
box and the front of the shoe is toe lasted in the usual
manner.
It will be noted that the steel box toe 16 is
now situated between the vamp 14 and the toe piece 13 and
that the flange 17 of the steel box toe is sandwiched bet-
ween these two portions and seated substantially within the
recess 25.
The aforementioned welt strip 15 is now position-
ed around the entire perimeter of the boot and the horizon-
tal stitch line 26 is formed extending through the welt strip,
through adjacent the lower perimeters of the toe piece 13
and the vamp 14, and through the downwardly and vertically
inclining sewing rib 20, it being noted that the flange 17
does not interfere with this stitching action.
The remaining portion of the manufacture is con-
v~ntional and includes the vertical stitch line 27 which ex-
tends through the welt strip, and through the outsole assem-
bly 28 which, in this embodiment, includes the inner layer
29 and the relatively thick rubber or crepe layer 30.
Although the insole assembly 10 is shown and des-
cribed as being formed from the upper and lower portions 18
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and 19 laminated together, it will be appreciated that a
relatively thick insole assembly could be provided with
the recess being machine formed by removing material around
the toe area. However, the normal method of production is
as shown and described.
It will therefore be seen that the incorporation
of the novel insole assembly enables a relatively deeply
flanged box toe 16 to be incorporated in a goodyear welt
construction utilizing conventional sewing machinery and
following conventional lasting techniques.
Since various modifications can be made in my in-
vention as hereinabove described, and many apparently wide-
ly different embodiments of same made within the spirit and
scope of the claims without departing from such spirit and
scope, it is intended that all matter contained in the ac-
companying specification shall be interpreted as illustra-
tive only and not in a limiting sense.
