MOLD FOR BOOT

MOULE A BOTTES

English Abstract

ABSTRACT OF THE DISCLOSURE
A mold for use in the slush molding of boots with eyelets
includes a pair of narrow, elongated grooves on its interior
surface at the front side edges of the mold for forming relatively
strong, one-piece, single thickness eyelet stays. The mold is in
the form of a boot-shaped shell for receiving heat-curable plasti-
sol, and forming a skin including one-piece eyelet stays.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A mold for use in the slush molding of a boot with
eyelet stays, comprising a shell mold defining a hollow boot-
shaped cavity for receiving heat-curable plastisol having an
interior surface comprising a front upper portion with a longitud-
inal centerline, and means for forming single thickness eyelet
stays comprising two narrow, elongated grooves in said front
upper portion in spaced apart relationship, one on each side of
and collateral with said longitudinal centerline, each of said
grooves being narrow enough and deep enough such that during the
slush molding, the plastisol received therein forms a single
thickness eyelet stay.

Description

This invention relates to a boot mold, and in particular
to a mold for slush molding a boot.
As described, for example, in Canadian Patents Nos.
592,262 and 594,464, issued to A. Cervinka on February 9, 1960
and March 15, 1960, respectively, calf-length boots are produced
by a slush molding process in which a mold in the shape of the
boot is filled with plastisol, e.g., polyvinyl chloride, the mold
is heated to cause the plastisol to gel and form a skin, excess
plastisol is poured from the mold, and the mold is again heated
to cure the plastisol.
When applying the above process to the molding of shorter
boots, i.e., boots of ankle or slightly above ankle length, the
steps are the same. However, attempts to produce a slush molded
boot with eyelet stays for receiving metal lace eyelets have met
with marginal success. In accordance with one such attempt, the
i front side of the mold was provided with a pair of wide projec-
tions, which appear as wide grooves in the inner surface of the
mold for receiving plastisol. The resulting boot skin has excess
material on each side at the front thereof for folding together
to form double thickness eyelet stays.
The problems with double thickness eyelet stays are that
they require a large excess of plastisol, and the resulting skin
is relatively weak. When the eyelet stays are formed with sep-
arate sides and a liner is inserted in the skin because of the
excess material, it is difficult to draw the sides of the eyelet
stays together and insert the eyelets. Moreover, the eyelet stays
are relatively weak, since the two sides can tear separately.
The object of the present invention is to avoid or over-
come the above problems by providing a mold for slush molding a
boot with one-piece eyelet stays, whereby the quantity of plasti-
sol used in the boot skin is relatively small, and the eyelet
stays are as strong as possible for the material used in the skin.

3~
Accordingly, the present invention relates to a mold
for use in the slush moldin~ of a boot with eyelet stays, compris-
~ in~ a shell mold defining a hollow boot-shaped cavity for receivinc~
- heat-curable plastisol having an interior sur~ace comprising a
front upper portion with a lon~itudinal centerline, and means for
forming single thickness eyelet stays comprisin~ two narrow,
elongated grooves in said front upper portion in spaced apart
relationship, one on each side of and collateral with said longitu-
dinal centerline, each of said grooves being narrow enough and
deep enough such that during the slush molding, the plastisol
` received therein forms a single thickness eyelet stay.
The invention will now be described in greater de-tail
with reference to the accompanying drawings, which illustrate a
~I preferred embodiment of the inven-tion, and wherein:
" Figure 1 is a cross-sectional view of a plastisol skin
for a boot with eyelet stays produced in accordance with the prior
art method discussed hereinbefore;
Figure 2 is a cross-sectional view of a boot skin pro-
duced with the mold of the present invention;
Figure 3 is a perspective view of the mold of the
present invention; and
Figure 4 is a cross-sectional view taken generally along
the line 4-4 of Figure 3.
With reference to Figure 1 of the drawings, in accordance
with the prior art method of molding referred to hereinbefore, a
boot skin 1 is molded with projections 2 on the front sides
thereof. After insertion of a liner (not shown), sides 3 of each
of the projections are compressed together to form eyelet stays
and eyelets (not shown) are inserted through holes punched in the
eyelet stays. It is readily apparent that problems can be
encountered- in compressing the sides together, and that the sides
3 of the stays can tear separately.
~ - 2 -
A
`. . ~
... ..... . .. .

-
3'~
The mold of the present invention overcomes the above
problems by providing for the molding of A boot skin S having
one-piece eyelet stays 6 projecting forwardly from each of the
sides thereof. The stays 6 can readily be folded over the front
central portion 7 of the boot upper. Moreover, because of the
single
~, 10
: . .
. ~
~ . , .
~ .
.~ .
.~ ' '
~ 30
_.
.
- 2a -
. .'. ' .
~ . :

~ 9
thickness of ma-terial in ~he eyelet stays 6, tearing of the stays
in the area of eyelet holes 8 is unlikely.
Referring now to Figures 3 and 4 of the drawings, a mold
10 in accordance with the present invention is mounted in a rec-
tangular frame 11 for connecting the mold to a mold carrier (not
shown), which is mounted on a continuous conveyor of the type
disclosed in applicant's co-pending Canadian Patent Application
Serial No. 167,591, filed March 30, 1973. Since the conveyor
and mold carrier do not form part of the present invention, no
detailed description of such elements is necessary, except to
mention that the conveyor and a plurality of carriers are used to
move molds through the cycle referred to hereinbefore, namely
mold filling, heating to form a skin, discharging of excess plas-
tisol and curing with heat.
The mold 10 itself is boot-shaped, including a shell
defining a sole portion 13 and an upper portion 14. The upper
` portion 14 is provided with a generally cylindrical ankle and leg
forming sleeve 15, with a slightly flaring open top end 17 for
receiving plastisol. An elongated projection 18 extends outwardly
from each side of the front of the sleeve 15, the projection
defining an elongated groove or recess 20 on each side of the
interior of the mold for forming the eyelet stays 6 (Figure 2).
In use, the mold 10 is filled with plastisol and is heated
to form a boot skin 5, with solid, one-piece eyelet stays 6.
Following formation of the skin, excess plastisol is poured out
of the mold, and the skin left behind is cured, if necessary,
reinforced and finally removed from the mold for finishing. By
finishing is meant the lining and trimming of the skin, and the
insertion of eyelets in the stays 6.