U.S. patent application number 16/223142 was filed with the patent office on 2020-06-18 for flexible synchronous toothed belt with narrow splice.
This patent application is currently assigned to ContiTech Antriebssysteme GmbH. The applicant listed for this patent is ContiTech Antriebssysteme GmbH. Invention is credited to Douglas Bruce Wood.
Application Number | 20200187420 16/223142 |
Document ID | / |
Family ID | 69061347 |
Filed Date | 2020-06-18 |
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United States Patent
Application |
20200187420 |
Kind Code |
A1 |
Wood; Douglas Bruce |
June 18, 2020 |
FLEXIBLE SYNCHRONOUS TOOTHED BELT WITH NARROW SPLICE
Abstract
Belts having a cover layer and opposing continuous tooth section
defining an outer surface, a cross-linked elastomeric body, and a
tensile reinforcement section disposed between the cover layer and
the cross-linked elastomeric body. The continuous tooth section
includes a plurality of tooth structures, each having tooth flank,
a land, and an easement area between the tooth flank and the land,
and the easement area has a progressively decreasing radial
thickness from the tooth flank to the land. In some aspects, the
easement area has a low pressure-angle of contact with a sprocket,
when engaging a sprocket. In some aspects, the belt is an endless
belt, while in some other aspects, the belt is a spliced belt
having a splice.
Inventors: |
Wood; Douglas Bruce;
(Lincoln, NE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ContiTech Antriebssysteme GmbH |
Hannover |
|
DE |
|
|
Assignee: |
ContiTech Antriebssysteme
GmbH
Hannover
DE
|
Family ID: |
69061347 |
Appl. No.: |
16/223142 |
Filed: |
December 18, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65G 2201/0202 20130101;
B65G 15/42 20130101; A01D 61/002 20130101; B65G 23/06 20130101;
B65G 15/36 20130101; B65G 2201/04 20130101; B65G 2812/02217
20130101; A01D 57/20 20130101; F16G 3/06 20130101; F16G 1/28
20130101 |
International
Class: |
A01D 61/00 20060101
A01D061/00; A01D 57/20 20060101 A01D057/20; B65G 23/06 20060101
B65G023/06; B65G 15/36 20060101 B65G015/36 |
Claims
1. A belt comprising: a cover layer and opposing continuous tooth
section defining an outer surface; a cross-linked elastomeric body;
and, a tensile reinforcement section disposed between the cover
layer and the cross-linked elastomeric body; wherein the continuous
tooth section is comprised of a plurality of tooth structures;
wherein each tooth of the plurality of tooth structures comprises a
tooth flank, a land, and an easement area between the tooth flank
and the land; and, wherein the easement area has a progressively
decreasing radial thickness from the tooth flank to the land.
2. The belt according to claim 1, wherein the easement area has a
low pressure-angle of contact with a sprocket.
3. The belt according to claim 2, wherein the low pressure-angle of
contact provides a large shear area.
4. The belt according to claim 1, wherein the belt is an endless
belt.
5. The belt according to claim 1, wherein the belt is a spliced
belt having a splice.
6. The belt according to claim 5, wherein the splice is positioned
in one tooth structure between a pair of corresponding lands.
7. The belt according to claim 6, wherein the splice comprises a
pair of looped cords extending from ends of the tensile
reinforcement section, a pair of glad hand connectors disposed
between the pair of looped cords, a clamp disposed over the pair
and the pair of looped cords on a side of the belt comprising the
cover layer, and a bottom clamp disposed on an end of the one
tooth, wherein a clamp connector extends through the clamp and
between the pair of glad hand connectors, and wherein the clamp
connector securely engages the bottom clamp.
8. The belt according to claim 7, wherein a deadman is disposed
within each loop comprised in the pair of looped cords.
9. The belt according to claim 8, wherein the deadman comprises a
kickstand structure.
10. A spliced belt comprising a cover layer and opposing continuous
tooth section defining an outer surface, wherein the continuous
tooth section is comprised of a plurality of tooth structures, and
wherein each tooth of the plurality of tooth structures comprises a
tooth flank, and a land; a cross-linked elastomeric body; and, a
tensile reinforcement section disposed between the cover layer and
the cross-linked elastomeric body; and, a splice positioned in one
tooth structure between a pair of corresponding lands; wherein the
splice comprises a pair of looped cords extending from ends of the
tensile reinforcement section, a pair of glad hand connectors
disposed between the pair of looped cords, a clamp disposed over
the pair and the pair of looped cords on a side of the belt
comprising the cover layer, and a bottom clamp disposed on an end
of the one tooth, wherein a clamp connector extends through the
clamp and between the pair of glad hand connectors, and wherein the
clamp connector securely engages the bottom clamp.
11. The spliced belt according to claim 10 further comprising an
easement area between the tooth flank and the land.
12. The spliced belt according to claim 11, wherein the easement
area has a progressively decreasing radial thickness from the tooth
flank to the land.
12. The spliced belt according to claim 11, wherein the easement
area has a low pressure-angle of contact with a sprocket.
14. The spliced belt according to claim 10, wherein a deadman is
disposed within each loop comprised in the pair of looped
cords.
15. The spliced belt according to claim 14, wherein the deadman
comprises a kickstand structure.
16. A feederhousing comprising a plurality of elastomeric drive
belts, wherein each belt comprised in the plurality of elastomeric
drive belts comprises: a cover layer and opposing continuous tooth
section defining an outer surface; a cross-linked elastomeric body;
and, a tensile reinforcement section disposed between the cover
layer and the cross-linked elastomeric body; wherein the continuous
tooth section is comprised of a plurality of tooth structures;
wherein each tooth of the plurality of tooth structures comprises a
tooth flank, a land, and an easement area between the tooth flank
and the land; and, wherein the easement area has a progressively
decreasing radial thickness from the tooth flank to the land.
17. The feederhousing according to claim 16, wherein the easement
area has a low pressure-angle of contact with a sprocket.
18. The feederhousing according to claim 16, wherein the plurality
of elastomeric drive belts are endless belts.
19. The feederhousing according to claim 16, wherein the plurality
of elastomeric drive belts are spliced belts, wherein each of the
spliced belts further comprise a splice positioned in one tooth
structure between a pair of corresponding lands; and, wherein the
splice comprises a pair of looped cords extending from ends of the
tensile reinforcement section, a pair of glad hand connectors
disposed between the pair of looped cords, a clamp disposed over
the pair and the pair of looped cords on a side of the belt
comprising the cover layer, and a bottom clamp disposed on an end
of the one tooth, wherein a clamp connector extends through the
clamp and between the pair of glad hand connectors, and wherein the
clamp connector securely engages the bottom clamp.
20. The feederhousing according to claim 19, wherein a deadman is
disposed within each loop comprised in the pair of looped cords,
and wherein the deadman comprises a kickstand structure.
Description
FIELD
[0001] The field to which the disclosure generally relates is
toothed belts useful for harvesting machines, and more particularly
to toothed belts used in feederhousings.
BACKGROUND
[0002] This section provides background information to facilitate a
better understanding of the various aspects of the disclosure. It
should be understood that the statements in this section of this
document are to be read in this light, and not as admissions of
prior art.
[0003] Agricultural harvesting machines such as combine harvesters
are used to reap, thresh, and winnow grain crops such as wheat,
rye, barley, corn, soybeans, oats, flax, sunflower, canola, and the
like. More specifically, combine harvesters are used to cut grain
crops at the base, separate the grains from the remainder of the
plant (the chaff), and sort the grain from the chaff. These
machines require special adaptations to accommodate specific crops,
navigate through field landscapes, and resist damage from the
crops, stone, and the elements; especially moisture and high
temperature which can lead to the degradation of the machine's
rubber components.
[0004] Generally, combine harvesting machines gather crops using a
header as the machine moves through a field. The header may be one
of several types, each of which provides a means of gathering a
particular type of crop. The header is connected to a feederhousing
which provides a means of conveying the crop to a threshing
mechanism which is part of the harvesting machine.
[0005] In one type of header which is useful for small grain, the
gathered crops are pushed by a reel into a cutter bar, which runs
the length of the header and is equipped with teeth made of metal
or plastic to cut crops at their base. Headers may have a rigid or
flexible header platform depending upon the operator's needs.
Flexible header platforms, or "flex headers" have a cutter bar
which is capable of flexing over uneven terrain. Machines using
flex headers are most often used to cut soybeans, whereas
conventional header platforms have a rigid cutter bar and are most
often used to cut cereal crops. Freshly cut crops fall behind the
cutter bar and onto a plurality of draper belts which are wrapped
around parallel spaced rollers. Draper belts function primarily to
consolidate crops and move the crops within the header towards a
feederhousing, which then conveys the crops to a threshing
mechanism. Alternatively, the freshly cut crop may be conveyed
within the header to the feederhousing by augers.
[0006] A second type of header is useful for row crops such as
corn. This type of header has dividers which define crop gathering
gaps for each crop row. In each gap, the ears of corn containing
the corn grain kernels is removed from the corn stock and is
conveyed by auger or belt to the feederhousing. The stalk and other
plant residue are separated from the ears and remain in the field
so that the amount of material processed by the threshing mechanism
is minimized.
[0007] A third type of header is useful for crops which have been
previously cut and collected for drying or other aging in the
field. This type of header includes a pick-up apron to convey the
cut crop into the header and onto a plurality of draper belts which
are wrapped around parallel spaced rollers. The draper belts
function primarily to consolidate crops and to gently move the
crops within the header towards a feederhousing, which then conveys
the crops to the threshing mechanism.
[0008] For each header type, the feederhousing movably supports the
header and connects it to the threshing mechanism contained in the
main body of the combine harvester. The feederhousing includes a
closed channel, typically of rectangular cross section, having an
inlet opening at the forward end which engages the header at the
point where the header discharges the crop. The feederhousing has a
discharge opening at the rearward end which engages the desired
inlet area of the threshing mechanism. The crop is conveyed within
the closed channel of the feederhousing from the header to the
threshing mechanism by bars or cleats which are attached to chains
or belts. The chains or belts are supported by a shaft and
sprockets near the discharge opening, and by one or more shafts or
drums near the inlet opening. Rotation of the belts or chains about
the shafts moves the bars or cleats in a closed loop path from the
inlet to the discharge. The moving bars or cleats carry or drag the
crop from the header to the threshing mechanism.
[0009] Additional mechanisms within the feederhousing may be used
to assist the conveyance of the crop. They may guide the path of
the bars or cleats or chains, allow limited motion of the drums,
and/or control the tension of the chain. The bars and belts or
chains are subject to abrasive wear from contact with the crop, and
to damage from foreign object that inadvertently enter the
feederhousing. Belts made in a continuous loop are difficult to
install in a traditional feederhousing, so an assembly of belts and
bars in which the continuous loop can be opened for installation is
useful.
[0010] Inside the threshing mechanism, the grain is separated from
the plant stems, cobs, straw, leaves, and chaff. The threshed
grains are collected in a grain collecting tank, and the plant
waste, or chaff, is moved to discharge openings of the threshing
mechanism for disposal to the field or for collection if desired as
a secondary product.
[0011] Other harvesting machines are used for cutting silage. The
header of this machine usually is made to engage with row crops,
but instead of striping ears from the stalk, the stalk is cut near
the ground and the entire plant is conveyed to the feederhousing.
The feederhousing conveys the plant to a chopping mechanism instead
of a threshing mechanism to produce animal feed.
[0012] Some problems with the use of chains to convey crops within
the feederhousing are high weight, excessive noise generation while
in operation, chain wear, and chain stretch. Accordingly, there is
an ongoing need for improved feederhousing components which improve
on the current problems in the art, the need met at least in part,
by embodiments according to the disclosure.
SUMMARY
[0013] This summary is provided to introduce a selection of
concepts that are further described below in the detailed
description. This summary is not intended to identify key or
essential features of the claimed subject matter, nor is it
intended to be used as an aid in limiting the scope of the claimed
subject matter.
[0014] Some embodiments of the disclosure are directed to belts
having a cover layer and opposing continuous tooth section defining
an outer surface, a cross-linked elastomeric body, and a tensile
reinforcement section disposed between the cover layer and the
cross-linked elastomeric body. The continuous tooth section
includes a plurality of tooth structures, each having tooth flank,
a land, and an easement area between the tooth flank and the land,
and the easement area has a progressively decreasing radial
thickness from the tooth flank to the land. In some aspects, the
easement area reduces shear stress between the tensile
reinforcement and the elastomeric body of the tooth. In some
aspects, the easement area provides a gradual change in belt
bending stiffness from a high bending stiffness near the tooth
flank to a low bending stiffness near the land. In some aspects,
the easement area controls the bending radius of the tensile layer
between the tooth flank and the land as the belt engages a
sprocket.
[0015] In some aspects, the easement area near the land has a low
angle of contact with the outer portion of a sprocket tooth when
engaging a sprocket, and the low angle of contact may provide a
radial or circumferential displacement of the belt with respect to
the sprocket when forces applied to the belt tooth flank by the
sprocket tooth are excessive, and the displacement of the belt can
transfer a portion of those forces to other belt tooth structures
of the continuous tooth section, thus limiting the force applied to
an individual tooth. In some aspects, the belt is an endless belt,
while in some other aspects, the belt is a spliced belt having a
splice.
[0016] Where the belts are spliced belts, the belt is first made in
an open loop containing a desired number of whole teeth along the
loop, and with a partial tooth at each end of the loop. When the
partial teeth are joined at installation, a splice is positioned in
one tooth structure between a pair of corresponding lands. In some
cases, the splice may include such elements as a pair of looped
cords extending from ends of the tensile reinforcement section, a
pair of connectors disposed between the pair of looped cords, a
clamp disposed over the pair of connectors and the pair of looped
cords on a side of the belt comprising the cover layer, and/or a
bottom clamp disposed on an end of the one tooth, where a clamp
connector may extend through the clamp and between the pair of glad
hand connectors, and where the clamp connector may securely engage
the bottom clamp. A deadman may be disposed within each loop of the
pair of looped cords, and in some cases, the deadman have a
kickstand structure.
[0017] Some other embodiments of the disclosure are spliced belts
having a cover layer and opposing continuous tooth section defining
an outer surface, where the continuous tooth section has a
plurality of tooth structures, and where each tooth of the
plurality of tooth structures has a tooth flank, a land, and an
easement area between the tooth flank and the land. The belt also
includes a cross-linked elastomeric body, a tensile reinforcement
section disposed between the cover layer and the cross-linked
elastomeric body, and a splice positioned in one tooth structure
between a pair of corresponding lands. The splice has a pair of
looped cords extending from ends of the tensile reinforcement
section, a pair of glad hand connectors disposed between the pair
of looped cords, a clamp disposed over the pair and the pair of
looped cords on a side of the belt having the cover layer, and a
bottom clamp disposed on an end of the one tooth. The clamp
connector extends through the clamp and between the pair of glad
hand connectors, and the clamp connector securely engages the
bottom clamp. In some aspects, a deadman is disposed within each
loop comprised in the pair of looped cords, and the deadman may
have a kickstand structure.
[0018] The easement area may have a progressively decreasing radial
thickness from the tooth flank to the land, and the easement area
may have a low angle of contact with a sprocket at the land end. By
extending, within one tooth, the shear area between the tooth and
the cord is increased, thus reducing the stress placed on the
cord.
[0019] Yet other embodiments of the disclosure are directed to
feederhousings having a plurality of elastomeric drive belts, where
each belt comprised in the plurality of elastomeric drive belts
includes a cover layer and opposing continuous tooth section
defining an outer surface, a cross-linked elastomeric body, and a
tensile reinforcement section disposed between the cover layer and
the cross-linked elastomeric body. The continuous tooth section
includes a plurality of tooth structures, each having a tooth
flank, a land, and an easement area between the tooth flank and the
land. The easement area has a progressively decreasing radial
thickness from the tooth flank to the land, and may have a low
pressure-angle of contact with a sprocket. In some aspects, the
belt is an endless belt, while in some other aspects, the belt is a
spliced belt having a splice.
[0020] Where the elastomeric drive belts are spliced belts, each of
the spliced belts further include a splice positioned in one tooth
structure between a pair of corresponding lands. The splice may
have such elements as a pair of looped cords extending from ends of
the tensile reinforcement section, a pair of glad hand connectors
disposed between the pair of looped cords, a clamp disposed over
the pair and the pair of looped cords on a side of the belt having
the cover layer, and/or a bottom clamp disposed on an end of the
one tooth. A clamp connector may extend through the clamp and
between the pair of glad hand connectors, and the clamp connector
may securely engage the bottom clamp. In some cases, a deadman in
disposed within each loop of the pair of looped cords, and the
deadman may have a kickstand structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Certain embodiments of the disclosure will hereafter be
described with reference to the accompanying drawings, wherein like
reference numerals denote like elements. It should be understood,
however, that the accompanying figures illustrate the various
implementations described herein and are not meant to limit the
scope of various technologies described herein, and wherein:
[0022] FIG. 1 illustrates a portion of a belt in a fragmented
perspective view according to the disclosure;
[0023] FIG. 2 depicts a portion of a belt in a fragmented
perspective view according to another aspect of the disclosure;
[0024] FIG. 3 shows a portion of a convention belt in rack form, in
a cross-section view;
[0025] FIG. 4 depicts a section of the trapezoidal toothed belt
shown in FIG. 3, when wrapped around a sprocket in an ideal form,
in a cross-section view;
[0026] FIG. 5 illustrates a section of the trapezoidal toothed
belt, such as that shown in FIG. 3, when wrapped around a sprocket
in a form that has an undesirably small cord bending radius, in a
cross-section view;
[0027] FIG. 6 shows a section of a toothed belt according to the
disclosure, when wrapped around pins of a sprocket, in a
cross-section view;
[0028] FIG. 7 shows a splice of a spliced belt, in a cross-section
view according to the disclosure;
[0029] FIG. 8 depicts another splice of a spliced belt, in a
cross-section view according to the disclosure;
[0030] FIG. 9 illustrates another splice of a spliced belt, in a
cross-section view according to the disclosure;
[0031] FIG. 10 shows another splice of a spliced belt, in a
cross-section view according to the disclosure;
[0032] FIG. 11 depicts a combine harvester, in a perspective view
according to the disclosure;
[0033] FIG. 12 illustrates the front side of a feederhousing,
according to an aspect of the disclosure; and,
[0034] FIG. 13 shows a feederhousing mid-frame, in a perspective
view, according to another aspect of the disclosure.
DETAILED DESCRIPTION
[0035] The following description of the variations is merely
illustrative in nature and is in no way intended to limit the scope
of the disclosure, its application, or uses. The description and
examples are presented herein solely for the purpose of
illustrating the various embodiments of the disclosure and should
not be construed as a limitation to the scope and applicability of
the disclosure. In the summary of the disclosure and this detailed
description, each numerical value should be read once as modified
by the term "about" (unless already expressly so modified), and
then read again as not so modified unless otherwise indicated in
context. Also, in the summary of the disclosure and this detailed
description, it should be understood that a value range listed or
described as being useful, suitable, or the like, is intended that
any and every value within the range, including the end points, is
to be considered as having been stated. For example, "a range of
from 1 to 10" is to be read as indicating each and every possible
number along the continuum between about 1 and about 10. Thus, even
if specific data points within the range, or even no data points
within the range, are explicitly identified or refer to only a few
specific, it is to be understood that inventors appreciate and
understand that any and all data points within the range are to be
considered to have been specified, and that inventors had
possession of the entire range and all points within the range.
[0036] Unless expressly stated to the contrary, "or" refers to an
inclusive or and not to an exclusive or. For example, a condition A
or B is satisfied by anyone of the following: A is true (or
present) and B is false (or not present), A is false (or not
present) and B is true (or present), and both A and B are true (or
present).
[0037] In addition, use of the "a" or "an" are employed to describe
elements and components of the embodiments herein. This is done
merely for convenience and to give a general sense of concepts
according to the disclosure. This description should be read to
include one or at least one and the singular also includes the
plural unless otherwise stated.
[0038] The terminology and phraseology used herein is for
descriptive purposes and should not be construed as limiting in
scope. Language such as "including," "comprising," "having,"
"containing," or "involving," and variations thereof, is intended
to be broad and encompass the subject matter listed thereafter,
equivalents, and additional subject matter not recited.
[0039] Also, as used herein any references to "one embodiment" or
"an embodiment" means that a particular element, feature,
structure, or characteristic described in connection with the
embodiment is included in at least one embodiment. The appearances
of the phrase "in one embodiment" in various places in the
specification are not necessarily referring to the same
embodiment.
[0040] In general, belts according to the disclosure include a
cover layer and opposing continuous tooth section defining an outer
surface as depicted in FIG. 1, which illustrates a portion of a
belt in a fragmented perspective view according to one embodiment
of the disclosure. In some cases, the belts are HNBR (hydrogenated
nitrile butadiene rubber) belts where the back side of the HNBR
belt is a cover 102 to protect the tensile cords. The cover can be
elastomer HNBR or fabric impregnated with elastomer. The tensile
cords 114 are embedded in a cord support elastomer 108 which may be
the same elastomer as used in the cover 102 or the body 106. It may
be a different elastomer if required by the manufacturing process
or by functional requirement of the elastomer region near the
cords. The body 106 is commonly called the tooth stock elastomer
and may not be continuous along the length of the belt. The toothed
surface of the belt 104 is usually covered with one or more layers
of continuous fabric that follow the contour of the tooth and the
land between the teeth. The outer surface of the outer fabric layer
112 may be impregnated with an elastomer with low coefficient of
friction and with resistance to abrasion as described in U.S. Pat.
No. 8,192,797 B2, the disclosure of which is incorporated herein in
its entirety, by reference thereto. The inner surface of the inner
layer of fabric may be impregnated with elastomer compatible with
the body 106 or the cord encapsulant 108. If more than one layer of
fabric is used, the surfaces between the layers may be impregnated
with the material of 104, 106, or 108. The tensile cords 114 may be
placed close to the inner fabric layer in the land area between the
belt teeth and define the neutral plane of the belt in bending.
[0041] In some other aspects, the cross-linked elastomeric body 106
is based upon a urethane material, formed from the reaction product
of a polyisocyanate and a hydroxyl functional polyol which react
during a molding process used in forming belt 100. The
polyisocyanate and the hydroxyl functional polyol may be injected
separately into the belt mold and reacted during the belt molding
process. Further, the polyisocyanate and the hydroxyl functional
polyol may envelop the fabric reinforcement prior to reacting
during the belt molding process; or in some cases during reacting
in the belt molding process. Prior to injection, the belt mold
typically contains the outer tension section 102, the tensile
reinforcement section 108 and the fabric reinforcement 110 prior to
injecting the polyisocyanate and the hydroxyl functional
polyol.
[0042] However, while the above are just two examples of materials
that may be used for the cross-linked elastomeric materials, it is
within the spirit and scope of the disclosure to use any suitable
material for the cross-linked elastomeric materials. Other
non-limiting examples of suitable elastomeric materials include
chloroprene rubber ("CR"), acrylonitrile butadiene rubber ("NBR"),
styrene-butadiene rubber ("SBR"), alkylated chlorosulfonated
polyethylene ("ACSM"), epichlorohydrin, butadiene rubber ("BR"),
natural rubber ("NR") and ethylene alpha olefin elastomers such as
ethylene propylene terpolymer ("EPDM") and ethylene propylene
copolymer ("EPM"), or a combination of any two or more of the
foregoing.
[0043] The materials forming the elastomeric body 106 and cover
layer 102 may be blended with conventional compounding ingredients
including fillers, plasticizers, carbon black, agents to reduce
static build up, stabilizers, vulcanization agents/curatives and
accelerators, in amounts conventionally employed.
[0044] The tensile reinforcement section 108 disposed between the
outer tension section and the cross-linked elastomeric body is
useful for providing support and strength to belts. In some
embodiments, the tensile reinforcement section 108 contains a
plurality of cords 114 aligned longitudinally along the length of
main body portion. It should be understood that, in general, any
type of tensile reinforcement section known to the art may be
utilized. Moreover, any desired material may be used as the tensile
members in the tensile reinforcement section, such as cotton,
rayon, nylon, polyester, aramid, steel, carbon fiber, PBO, and even
discontinuous fibers oriented for low load carrying capability. In
some aspects, the cords are embedded in a material, the embedding
material being an elastomeric material.
[0045] As depicted in FIG. 2, continuous tooth section 104 has a
plurality of tooth structures. Each tooth 116 of the plurality of
tooth structures includes tooth flanks 118, lands 120, and easement
areas 122 between the tooth flanks 118 and the lands 120, which is
illustrated in FIG. 2. According to embodiments of the disclosure,
the easement areas 122 have a progressively decreasing radial
thickness from the tooth flanks 118 to the lands 120. The easement
area 122 of the tooth profile may serve to support the plurality of
cords 114 on a curve, as well as improves fatigue life of plurality
of cords 114 by preventing small bend radiuses in the plurality of
cords 114, as belt 100 engages and bends around a sprocket.
[0046] At constant cord tension, the neutral plane does not get
shorter or longer as the belt is bent around a sprocket. The
tensile cords 114 are straight in the area above the tooth, the
easements and the land between teeth when the belt is under tension
between sprockets or other supports. The tensile cords 114 above
the tooth may be straight or curved when the belt under tension is
bent around a sprocket, depending on the bending stiffness of the
belt in the area of the tooth. In the absence of an easement 122,
the tensile cords 114 above the land 120 may be bent to the radius
of the top of the sprocket tooth, in an arc with total angle equal
to the angle between adjacent belt teeth. The arc radius is much
less than the outer radius of the sprocket teeth, and fatigue
damage to the cord 114 is increased in the land area 120. With the
easement 122 present, the cord 114 is supported at a gently
decreasing radius from the tooth flank to the land, and the arc
length at the land is reduced to near zero, resulting in reduced
fatigue of the cord 114. The support of the cord 114 in the
easement area 122 is partially due to the variable bending
stiffness of the belt 100 in the easement area 122, which also
supports the cord 114 if the belt is bent around a flat drum
instead of a sprocket. When the belt is bent around a sprocket, the
support of the cord 114 in the easement area 122 is also due to
decreasing radial thickness of the easement 122 from the tooth
flank to the land which conforms to the flanks 118 of the sprocket
tooth as the belt 100 is bent.
[0047] Now referencing FIG. 3, which illustrates in a portion of
conventional toothed belt in rack form (the neutral plane is a
straight line). FIG. 3 shows one belt tooth 302, top surface 304 of
the belt and a portion of the belt lands 306, 308 between the teeth
on either side of the tooth 302. Line 310 is the neutral plane of
the belt which would be near the center of tensile cords. The
trapezoidal tooth 302 defines bottom 312. The tooth 302 also
defines flanks 314, 316 of the trapezoidal tooth, which are joined
to the lands 306, 308 and tooth bottom 312 with fillet curves 318,
320, 322, 324. In one non-limiting example, the belt has a tooth
pitch of 50 mm, neutral plane 310 to lands 306, 308 of 1.7 mm, and
neutral plane 310 to top surface 304 of 1.5 mm.
[0048] FIG. 4 depicts a section of the trapezoidal toothed belt
shown in FIG. 3, when wrapped around a sprocket in an ideal form.
Two cylindrical teeth 402, 404 on sprocket 406 are shown. The
angled lines 408, 410 passing through the two cylindrical teeth
402, 404 represent one pitch of sprocket 406 and meet on the center
412 of sprocket 406. The belt also defines top surface 304 and
neutral plane 310 which is near the center of tensile cords. The
belt tooth 302 and lands 306, 308 are deformed into an idealized
shape where the lands are in contact with the outer diameter of
sprocket 406, and the lands 306, 308 as well as belt tooth 302 are
curved so that the belt neutral plane 310 is an arc with constant
radius centered at the center 412 of the sprocket 406. The bending
radius of cords is the sprocket outside radius plus the belt
neutral plane to land distance. This the condition which provides
the largest possible cord bend radius for the given sprocket size
(pitch and number of teeth). For example, where the belt tooth
pitch is 50 mm, neutral plane to land is 1.7 mm, neutral plane to
top is 1.5 mm, sprocket pitch is 50 mm, and number of teeth is 10,
the tooth-to-tooth angle is 36.degree., having half angle of
18.degree., sprocket pin outer diameter is 20 mm, cord bend radius
is 79.577 mm and pitch line arc length is 50 mm.
[0049] Now referencing FIG. 5, which illustrates a section of the
trapezoidal toothed belt, such as that shown in FIG. 3, when
wrapped around a sprocket 506 in a form that has an undesirably
small cord bending radius, and where the belt land wraps around the
cylindrical teeth 502, 504 of the sprocket 506, at regions 520,
522. Here, the belt cords, positioned about belt neutral plane 510,
are under tension, which pulls the unsupported belt tooth 512 and
parts of the lands 514, 516 into a chordal straight-line X. The
tension also holds part of the lands at regions 524, 526 in an arc
around the outer diameter of the cylindrical sprocket teeth 502,
504. The minimum bending radius of the cord is the radius of the
sprocket pin plus the belt PLD neutral plane to land, which is
significantly smaller than that depicted in FIG. 4, and, for
example, in comparison, has a cord bend radius of 11.7 mm at arc of
36.degree. with a ten tooth sprocket.
[0050] FIG. 6 depicts a section of a toothed belt according to the
disclosure, when wrapped around pins of a sprocket. As shown,
toothed belt 600 includes easements 606, 608 wrapped around pins
602, 604 of sprocket 610. The easements 606, 608 are a transition
area between the belt tooth flank 612, 614 and the land 616, 618,
which significantly shorten the length of the land, between teeth,
in comparison to that shown FIG. 5. Such easements 606, 608 prevent
the undesirably small cord bending radius of FIG. 5 where the land
514, 516 wraps around the sprocket tooth pin 502, 504. The belt
cords, positioned about belt neutral plane 620, are under tension
and the bending stiffness of the belt 600 in the tooth 622 area may
hold the cord above the tooth 622 in a straight chordal line or in
a slight curve with a significantly larger cord bending radius than
that depicted in FIG. 5. The bottom 624 of the tooth 622 is
unsupported. Further, easement 606 or 608 can be defined as a belt
structure as having a progressively decreasing radial thickness,
relative sprocket 610 center point 626, between tooth flank 612,
614 and land 616, 618 respectively. This is contrast to that
depicted in FIG. 5 where there exists a gap between a significant
portion of the land and tooth flank relative the sprocket pin
surface, as well as a consistent radial thickness over a majority
of the land length, with an steep increase in radial thickness from
the land to tooth flank (or otherwise a steep decrease in radial
thickness between tooth flank and land). In another aspect, the
radius of the belt at easement 606 or 608 are like or similar to
the radius of the sprocket pin 602 or 604.
[0051] Each easement area 606, 608 acts as a tapered cantilever
beam to support the cord at a variable radius, until the easement
606, 608 deforms to contact the sprocket pin 602, 604. Upon contact
between the sprocket pin 602, 604 and the lower surface of the
easement 606, 608, the cord bending radius is determined by the
radial thickness of the deformed easement 606, 608 at each point
between the tooth flank 612, 614 and the small remaining land 616,
618. The narrow land is in contact with the sprocket at the outer
diameter of the sprocket pin, but the arc of contact is very small
and the curve of the cord over the easement brings the cord tangent
to the cord at the end of the easement of the next tooth. The
minimum bend radius of the cord is much greater than the minimum
radius shown in FIG. 5.
[0052] In some aspects, belts according to the disclosure, having
easement area designs which reduce the peak shear stress and
increased tooth fatigue life due to larger shear area, may be
useful in an endless belt where the drive shaft(s)/sprockets are
removeable from the equipment in which the belt is used. In some
other aspects, the belts according to the disclosure may be spliced
belts which are installed in equipment without removal of drive
shaft(s)/sprockets.
[0053] Now referencing FIG. 7, which depicts a splice of a spliced
belt, in a cross-section view. In this embodiment, spliced belt 700
includes a first end 702 and opposing second end 704. A tensile
reinforcement section includes a plurality of cords 706, disposed
between a cover layer 708 and a cross-linked elastomeric body 710.
Cords 706 extend from both first end 702 and opposing second end
704. The extended portion of the pair of cords 706 are each looped
to form looped cords 712, which are positioned in a tooth structure
of spliced belt 700, between a pair of corresponding lands 714. An
optional fabric layer 715 may be disposed on the outer surface of
the tooth structure, or slightly inward therefrom. A pair of glad
hand connectors 716 are disposed between the pair of looped cords
712, and a clamp 718 disposed over the pair of looped cords 712 on
a side of the belt 700 where the cover layer 708 is located. A
bottom clamp 720 is disposed on an end of the tooth structure, and
a clamp connector 722 extends through the clamp 718 and between the
pair of glad hand connectors 716, and the clamp connector 722
securely engages the bottom clamp 720. After assembling the splice,
an air space compression zone 724 may remain outwardly from looped
cords 712. In some aspects, a deadman 726 is disposed within looped
cords 712.
[0054] Ends 702 and 704 are two ends of the same belt, and each end
contains one half of the tooth, including one deadman 726, and one
septum (716). FIG. 7 shows slightly more than one pitch and
includes only the two half-tooth ends with the septums in contact,
along with the top 718, bottom clamp 720 and connector 722. Bottom
clamp 720 interferes with the tooth fabric and rubber in this
assembled view. The looped cords are shown as turned in a 270
degree loop, which, as tension in the cords 706 increases, the
loops provide a self-activating increase in the clamping force on
the end of the cord loop between the deadman 726 and upper clamp
718. In some other aspects of the disclosure, the loops could be
turned in any suitable amount, such as, but not necessarily limited
to, 45 degrees, 90 degrees, 180 degrees, or even 360 degrees.
[0055] With reference to FIG. 8, which depicts another splice of a
spliced belt, in a cross-section view in accordance with the
disclosure, and in this embodiment, spliced belt 800 includes a
first end 802 and opposing second end 804. Similar to above,
tensile reinforcement section includes a plurality of cords 806,
disposed between a cover layer 808 and a cross-linked elastomeric
body 810 where cords 806 extend from both first end 802 and
opposing second end 804. The extended portion of cords 806 are each
looped to form looped cords 812, positioned in a tooth structure of
spliced belt 800, between a pair of corresponding lands 814. An
optional fabric layer 815 may be disposed on the outer surface of
the tooth structure, or slightly inward therefrom. A pair of glad
hand connectors 816 are disposed between the pair of looped cords
812, and a clamp 818 disposed over the pair of looped cords 812. A
bottom clamp 820 is disposed on an end of the tooth structure, and
a clamp connector 822 extends through the clamp 818 and between the
pair of glad hand connectors 816, and the clamp connector 822
securely engages the bottom clamp 820, while an air space
compression zone 824 remains outwardly from looped cords 812. A
deadman 826 is disposed within looped cords 812.
[0056] Deadman 826 includes a kickstand 828. The kick stands 828,
glad hands 816 and mold used to form the belt end confine the
deadman 826 and displace rubber encapsulating the cord 826 to
create pinch points and glands. The first pinch point 830 is just
above the 90-degree cord bend from horizontal to vertical, and the
first gland 832 is above the first pinch point 830. A second pinch
point 834 is in the 180-degree bend at the top. The cut end of the
cord ends at the top of the kickstand 828 in the second gland 836.
With 270 degrees of wrap, increasing the tension in the cords
causes the deadman 826 to rotate when the cord and elastomer in the
gland area 832 deforms. The kickstand 828 limits the rotation
movement of the deadman 826 so that it is not separated from the
septum 816 and overall pitch of the spliced tooth is accurately
maintained.
[0057] Now referencing FIG. 9, which depicts yet another splice of
a spliced belt, in a cross-section view. In this embodiment,
spliced belt 900 includes almost all of the same elements as shown
in FIG. 8 for spliced belt 800. However, ends of the cords are
extended to be pinched between the deadman kickstand and the clamp.
As depicted, the extended ends 902 from cord loops 812, of cord
806, is disposed between deadman 826 kickstands 828 and the clamp
818, or otherwise extended over the tip of the kickstands 828 to
clamp the ends of cord 806. Initial clamping force is provided by
top clamp 818 when securely connected to bottom clamp 820 via the
clamp connector. When belt 900 tension increases, the cord 806
tension in a first bend increases the clamp force between the tip
of kickstand 902 and clamp 818. Rotation of the deadmans 826 is
prevented by the pinch point and the contact of the cord ends 902
and encapsulating rubber in the first glands 832 against glad hands
816. In FIG. 8, the adhesion and compression of the cord and
elastomer in gland 836 resist any tension in the cord near the end
of the loop. However, in FIG. 9, both the cord clamping effect of
FIG. 7 and the limiting of deadman rotation by the kickstand in
FIG. 8 are combined and gland 836 has the proper tapered shape.
[0058] The glad-hands shown on the above figures are formed of a
pair of septums which are essentially symmetric with an
interlocking feature. The septums can be brought in contact from
the left and right with vertical and horizontal alignment
controlled by glad-hand pins and sockets, after which the top and
bottom clamp can be applied.
[0059] With reference to FIG. 10, which depicts another splice of a
spliced belt, in a cross-section view in accordance with the
disclosure. In this embodiment, spliced belt 1000 includes many of
the same elements as described in the embodiments above including a
first end 1002 and opposing second end 1004, a plurality of cords
1006, where extended portion of cords 1006 are each looped to form
looped cords 1012, and a clamp 1018 disposed over the pair of
looped cords 1012. However, asymmetrical septum connectors 1040 and
1042 are disposed between the pair of looped cords 1012, and
beneath clamp 1018 disposed over the pair of looped cords 1012.
Deadmans 1026 with kickstands 1028 are disposed within looped cords
1012. The bottom clamp mechanism is incorporated into septum
connector 1040 and clamp connector 1022, as a part of septum
connector 1040, extends up between and between asymmetrical
connectors 1040, 1042, and through clamp 1018, and is secured to
clamp 1018 with a fastener. Asymmetrical septum connectors 1040 and
1042 may have corresponding mating interlocking features 1044 and
1046.
[0060] In contrast with the above figures, the septums 1040 and
1042 in FIG. 10 are not a glad-hand design (i.e. symmetrical
septums). Also, here a bottom clamp is incorporated in septum 1040,
and the septums 1040 and 1042 cannot be brought in contact from the
left and right unless septum 1040 is lower than septum 1042 so that
the interlocking features 1044 and 1046 do not interfere. After the
septum faces touch, the septum 1040 must be slid upward to the same
height as 1042. The vertical alignment is dependent on the
engagement of interlocking features 1044 and 1046.
[0061] Tensile testing was conducted on some belts according to the
disclosure, as well as some conventional design control belts. Each
tested belt sample was 70 mm wide. Belt sample N-1, from Table 1
was a straight tensile test of a belt strand without a splice, such
as a test for an endless belt. Belt sample L-1 had a lap splice
extending over 4 teeth in length. For belt sample L-1 one belt
strand was cut to have a 35 mm wide groove on the strand
centerline, and the second strand was cut to have a 35 mm wide
tongue on the centerline. The tongue of the second strand was
placed inside the groove of the first strand. The tongue and groove
were connected by metal clamps at the centerline of each of 4
teeth.
[0062] Belt samples D-1 to D-5 and K-1 to K-5 were butt splices of
the belt strand having the features of holding the ends of the
cords by wrapping around a deadman and capturing the belt ends with
top and bottom clamps, as described above for embodiments according
to the disclosure. Belt samples D-1 to D-5 were similar to shown in
FIG. 7, where the deadman does not have a kickstand and where the
path of the cables and encapsulating elastomer is relatively
uniform in thickness.
[0063] Belt samples K-1 to K-5 were similar to embodiments shown in
FIGS. 8-9, where the deadman does have a kickstand and where the
path of the cables and encapsulating elastomer varies in thickness
to bring the cables closer to the deadman at the pinch points and
to provide a tapered gland of encapsulating elastomer between the
pinch points. For belt samples K-1, K-4 and K-5, the ends of the
cables are captured by a pinch point between the top clamp and the
kickstand of the deadman, as shown in FIG. 9.
[0064] The belt samples tested in pairs by clamping them together
and applying a tensile load to the free ends. The specimen which
fails at the lowest tension is shown in the table. Belt sample K-4
was tested with K-5, and did not fail.
TABLE-US-00001 TABLE 1 Specimen Tension at break (lbf) SPLICE TYPE
N-1 23,191 NONE- BELT STRAND L-1 4,883 LAP SPLICE D-1 8,465 DEAD
MAN D-2 5,008 DEAD MAN D-3 8,080 DEAD MAN D-4 10,736 DEAD MAN D-5
6,000 DEAD MAN K-3 10,946 KICKSTAND K-2 11,725 KICKSTAND K-1 14,262
KICKSTAND K-4 14,294 KICKSTAND K-5 14,294 KICKSTAND
[0065] Belts according to the disclosure may be used in any
suitable application or equipment where the advantages of such
belts provide improvement over the conventional belts used. One
nonlimiting example of such equipment is a combine crop harvester
feederhousing.
[0066] FIG. 11 depicts one example of a conventional combine crop
harvester 1100, in perspective view, which is equipped with a
removable head 1102, this is designed for particular crops. Shown
is a corn head 1102, but other types include a grain platform, a
flex head which can cut soybeans as well as cereal crops, wheat
headers, also called "draper" headers, and the like.
[0067] Harvesting head 1102 includes an auger 1104 for conveying
harvested crop from each side toward center 1106, where it then
enters feederhousing 1108. The crop is carried up the feederhousing
1108 by one or more belts and flight elevator, then fed into the
thresher 1110 having the threshing mechanism of the combine 1100,
which generally includes a rotating threshing drum to which rasp
bars are bolted, to separate the crop and chaff. After primary
separation at the drum, the clean crop falls through a concave and
to a shoe, and thereafter lifted to container 1112.
[0068] Now referencing FIG. 12, which shows a front view of a
feederhousing 1200, where harvested crop is received and
concentrated. Feederhousing 1200 generally includes an outer
housing structure 1202 which defines a hollow 1204 therein. A feed
drum 1206 is disposed within hollow 1204 and rotatably attached to
outer housing structure 1202. Feed drum 1206 is rotated by belts
1208, and attached to belts 1208 are conveyor belt slats 1210 (five
shown). The feed drum 1206, belts 1208 and conveyor belt slats 1210
are part of a larger structure called a mid-frame, an example of
which is showing in FIG. 13.
[0069] With reference to FIG. 13, a feederhousing mid-frame is
shown in a perspective view. Mid-frame 1300 includes feed drum 1302
which is attachable to an outer housing structure (not shown), and
an axle with drive sprockets 1304. Belts 1306 are connected to both
feed drum 1302 and corresponding drive sprockets 1304. Attached to
belts 1306 are conveyor belt slats 1308 (ten shown).
[0070] The foregoing description of the embodiments has been
provided for purposes of illustration and description. Example
embodiments are provided so that this disclosure will be
sufficiently thorough, and will convey the scope to those who are
skilled in the art. Numerous specific details are set forth such as
examples of specific components, devices, and methods, to provide a
thorough understanding of embodiments of the disclosure, but are
not intended to be exhaustive or to limit the disclosure. It will
be appreciated that it is within the scope of the disclosure that
individual elements or features of a particular embodiment are
generally not limited to that particular embodiment, but, where
applicable, are interchangeable and can be used in a selected
embodiment, even if not specifically shown or described. The same
may also be varied in many ways. Such variations are not to be
regarded as a departure from the disclosure, and all such
modifications are intended to be included within the scope of the
disclosure.
[0071] Although a few embodiments of the disclosure have been
described in detail above, those of ordinary skill in the art will
readily appreciate that many modifications are possible without
materially departing from the teachings of this disclosure.
Accordingly, such modifications are intended to be included within
the scope of this disclosure as defined in the claims.
* * * * *