Note: Descriptions are shown in the official language in which they were submitted.
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BELT CONSTRUCTION AND METHOD OF MAKING THE SAME
Technical Field
This invention relates to a new endless
belt construction and to a new method of making such
a new endless belt construction.
Background Art
It is known to provide an endless belt
construction formed mainly of polymeric material and
comprising a tension section, a compression section,
a load carrying section disposed between the tension
section and the compression section and being
secured thereto, one of the sections comprising a
plurality of layers of polymeric material disposed
in stacked relation, and a plurality of bleeder
yarns disposed between an adjacent pair of the
layers of~ polymeric material and being secured
thereto to serve as fluid passages for any fluid
present at the interface between the adjacent pair
of layers of polymeric material during the heat
curing of the belt construction. For example, see
the U.S. patent to Rollaway, Jr., No. 4,434,019.
Disclosure of the Invention
It is one of the features of this
invention to provide a new method of making a belt
construction wherein trapped air and/or gases that
are formed between adjacent polymeric layers of the
belt construction during the heat curing of the belt
construction are bled to the exterior thereof.
In particular, it was found according to
the teachings of this invention that a relatively
thin non-woven sheet of material can be disposed
between the adjacent layers of the belt construction
to subsequently bleed the trapped air and/or gases
that are encountered during the subsequent heat
curing operation.
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For example, one embodiment of this
invention provides a method of making an endless
belt construction formed mainly of polymeric
material and comprising a tension section, a
compression section, a load carrying section
disposed between the tension section and the
compression section and being secured thereto by the
step of heat curing the belt construction, one of
the sections comprising a plurality of layers of
polymeric material disposed in stacked relation, the
method comprising the step of disposing a paper-like
sheet of non-woven material between an adjacent pair
of the layers of the polymeric material before the
step of heat curing so that the sheet is secured to
the adjacent pair of the layers during the step of
heat curing the belt construction.
Accordingly, it is an object of this
invention to provide a new method of making an
endless belt construction, the method of this
invention having one or more of the novel features
of this invention as set forth above or hereinafter
shown or described.
Another object of this invention is to
provide a new endless belt construction having one
or more of the novel features of this invention as
set forth above or hereinafter shown or described.
Brief Descrit~tion of the Drawings
The features of the invention, and its
technical advantages, can be seen from the following
description of the preferred embodiments together
with the claims and the accompanying drawings, in
which:
FIG. 1 is a fragmentary perspective view
that is partially in cross section and illustrates
the new belt construction of this invention;
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FIG. 2 is a reduced end view of another
new belt construction of this invention;
FIG. 3 is a reduced fragmentary side view
of another new belt construction of this invention;
FIG. 4 is a schematic perspective view
illustrating how the layers of the belt construction
of FIG. 1 can be formed on a drum to be subsequently
heat cured;
FIG. 5 is a schematic view illustrating
the belt construction and drum of FIG. 4 being heat
cured in a heat curing chamber;
FIG. 6 is a view similar to FIG. 4 and
illustrates another method of this invention for
forming another belt construction of this invention;
and
FIG. 7 is a schematic view illustrating
how individual belts can be formed from the belt
sleeve that is formed in the manner illustrated in
FIG. 4 or FIG. 6.
Description of the Preferred Embodiments
While the various features of this
invention are hereinafter illustrated and described
as providing belt constructions of particular
configurations, it is to be understood that the
various features of this invention can be utilized
singly or in any combination thereof to provide a
belt construction having any other configuration as
desired.
Therefore, this invention is not to be
limited to only the embodiments illustrated in the
drawings, because the drawings are merely utilized
to illustrate one of the wide variety of uses of
this invention.
Referring now to FIG. 1, the new endless
belt construction of this invention is generally
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indicated by the reference numeral 20 and is formed
mainly of polymeric material as will be apparent
hereinafter, the belt construction 20 comprising a
tension section 21, a compression section 22, and a
load carrying section 23 disposed between the
tension section 21 and the compression section 22
and being secured thereto during a subsequent heat
curing operation in a manner well known in the art.
For example, see the aforementioned U.S. patent to
Hollaway, Jr., No. 4,434,019, whereby this U.S.
patent is being incorporated into this disclosure by
this reference thereto.
The compression section 22 of the belt
construction 20 is formed from a plurality of
polymeric layers 24, 25 and 26 disposed in stacked
relation and uniquely having paper-like sheets 27 of
non-woven material disposed therebetween as well as
a like sheet 27 disposed between the polymeric layer
26 of the compression section 22 and the tension
section 23 for a purpose hereinafter set forth.
While FIG. 1 illustrates the sheets 27 by
a single line, it is to be understood that the
sheets 27 of this invention are so thin and open
that the same are actually substantially
nondetectable to the eye in the finished belt
construction 20.
Nevertheless, the sheets 27 of this
invention are adapted to bleed trapped air and/or
gases which are typically encountered from plying up
the layers 24, 25, 26 and 23 of smooth "tacky"
materials and may provide reinforcement to the
compression section 22, such as by providing a crack
barrier therefor.
The load carrying section 23 of the belt
construction 20 comprises a lower layer or cushion
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28 of polymeric material and an upper layer or
cushion 29 of polymeric material with a load
carrying cord 30 of polymeric material having been
helically wound on the cushion 28 before the cushion
5 29 is disposed thereon in a manner well known in the
art.
The tension section 21 comprises a woven
fabric 31 that has been treated with polymeric
material to comprise a layer 32 as illustrated in
FIG. 1 which is disposed against the top cushion 29
also in a manner well known in the art.
The endless belt construction 20 is formed
by forming an endless belt sleeve on a cylindrical
drum or mandrel 33 as illustrated in FIG. 4 which is
formed of any suitable material, such as metallic
material, and having an outer peripheral surface 34
against which the first layer 24 of material is
disposed or wrapped in a conventional manner.
Thereafter, the first paper-like sheet 27 of
material is disposed or wrapped on the layer 24 so
as to extend from one side edge means 35 of the
layer 24 to the opposite edge means 36 thereof so as
to be continuous throughout the entire width of the
layer 24 on the drum 33. The layers 25, 26 and 28
are likewise disposed or wrapped on the mandrel 33
in stacked relation therewith with the sheets 27
being disposed therebetween and extending completely
across the width of the layers 25, 26 and 28.
Thereafter, the cord 30 is helically wound on the
cushion 28 and then the cushion 29 is disposed on
the same. 'Subsequently, the tension layer 32 is
disposed on the outer cushion 29 and the mandrel 33
together with the material built thereon in the
manner previously described are disposed in a
chamber means 37 as illustrated in FIG.. 5 wherein
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the material is subjected to heat and pressure in a
conventional manner to heat cure the belt
construction 20, which is subsequently removed from
the chamber means 37 and cooled to form the belt
sleeve 38 illustrated in FIG. 7, wherein individual
endless belts 20 are cut therefrom by a suitable
cutter means 39 all in a manner well known in the
art.
As previously stated, during the heat
curing operation on the belt sleeve 38, it has been
found that the sheets 27 bleed trapped air and/or
gases from the interior of the belt construction 20
to the exterior thereof at the side edge means 35
and 36 while being completely bonded in between the
respective layers 24, 25, 26 and 28 during such heat
curing operation.
However, it has also been found according
to the teachings of this invention that the sheets
27 need not extend completely from one end edge to
the opposite end edge of the belt sleeve but can
merely be separate narrow sheets disposed adjacent
the end edges of the belt sleeve.
For example, reference is now made to FIG.
6 wherein another belt construction of this
invention is generally indicated by the reference
numeral 20A and parts thereof similar to the belt
construction 20 of FIG. 4 are indicated by like
reference numerals followed by the reference letter
..An .
As illustrated in FIG. 6, the layer 24A is
first disposed or wrapped on the external peripheral
surface 34A of the building drum 33A and then two
narrow paper-like sheets 27A of non-woven material
are disposed on the layer 24A so that the sheets 27A
respectively extend to the respective adjacent side
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edge means 35A or 36A of the layer 24A while leaving
the medial portion of the layer 24A uncovered as
illustrated in FIG. 6.
Thereafter, the additional layers to form
the belt construction 20A are built up on the drum
33A in the manner previously described except that
the sheets 27A do not cover the medial portions of
the various layers as it has been found that during
the subsequent heat curing operation, the pressure
on the medial portion of the resulting belt sleeve
38A is sufficient to force the air and/or gases in
the medial portions toward the outer edge means 35A
and 36A whereas the sheets 27A perform the function
of bleeding the air and/or gases at the outer
portions of the belt construction 38A to the side
edge means 35A and 36A in the manner previously set
forth.
While the belt construction 20 of this
invention illustrated in FIG. 1 has a substantially
straight inner surface 40, so as to be a
conventional "V" belt, the same could be shaped in
any desired manner.
For example, the inner surface 40 of the
belt construction 20 could be subsequently
longitudinally ground or cut to define a plurality
of longitudinal ribs 41 as illustrated in FIG. 2 or
the external peripheral surface 34 of the building
drum 33 could be corrugated as in the aforementioned
U.S. patent to Hollaway, No. 4,434,019, so as to
define a plurality of transverse teeth 42 in the
manner illustrated in FIG. 3.
In any event, the sheets 27 or 27A perform
their bleed function and the resulting belts 20
formed from such belt sleeves 38 or 38A that have
the material of the sheets 27 or 27A remaining
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therein may result in increased reinforcement of the
particular parts of the resulting belt 20 where such
sheets 27 or 27A are located.
Further, while the belt construction 20
has the sheets 27 disposed in the compression
section 22 and between the compression section 22
and the load carrying section 23 as previously
described, it is to be understood that the load
carrying section 23 and/or tension section 21 could
comprise a plurality of layers wherein a sheet 27 or
27A is disposed between adjacent layers as desired.
While it is believed that the various
layers of the belt construction 20 of this invention
can be formed from any suitable polymeric material
and be of any suitable thickness, one working
embodiment of a belt construction 20 that contains
the sheets 27 in the manner illustrated in FIG. 1
comprises a belt construction that has an outside
circumference of approximately 121.92 cm (48 inches)
and a belt thickness of approximately 0.457 cm
(0.180 of an inch) between the bottom surface 40 and
the top surface 40' thereof.
The layers 24, 25 and 26 of the
compression section 2 comprise chloroprene with
randomly disposed fiber reinforcement therein, with
each layer 24, 25 and 26 being approximately 0.102
cm (0.040 of an inch) thick before the heat curing
thereof. The paper-like sheets 27 each comprises a
non-woven fabric of polypropylene of approximately
0.170 kg/m2 (5 ounces per square yard) thereof and
being approximately 0.008 cm (0.003 of an inch)
thick before the heat curing thereof, such sheets 27
each having a light yellow or golden hue or even
being white and still being substantially
nondetectable in the finished belt construction 20.
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Such a non-woven sheet 27 is sold by the Flowtech
Company of Plymouth, Michigan.
The cushions 28 and 29 of the belt
construction 20 each comprises a chloroprene gum
stock layer that is approximately 0.051 cm (0.020 of
an inch) thick before the heat curing thereof and
the cord 30 comprises a polyester cord of
approximately 0.104 cm (0.041 of an inch) in
diameter before the heat curing thereof.
The tension section 21 is formed from a
fabric treated with chloroprene in a manner well
known in the art and is approximately 0.056 cm
(0.022 of an inch) thick before the heat curing
operation.
Thus, it can be seen that this invention
not only provides a new endless belt construction
but also this invention provides a new method of
making such an endless belt construction.
While the forms and methods of this
invention now preferred have been illustrated and
described as required, it is to be understood that
other forms and method steps can be utilized and
still fall within the scope of the appended claims.
