CA1108889A - Endless power transmission belt, method of making same, and drive system using same - Google Patents
Endless power transmission belt, method of making same, and drive system using sameInfo
- Publication number
- CA1108889A CA1108889A CA309,231A CA309231A CA1108889A CA 1108889 A CA1108889 A CA 1108889A CA 309231 A CA309231 A CA 309231A CA 1108889 A CA1108889 A CA 1108889A
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- yarns
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Abstract
ABSTRACT OF THE DISCLOSURE
An endless power transmission belt and method for producing the same, are provided herein. The belt has a portion which has a plurality of spaced belt elements defined by alternating projections and recesses with each of the elements having an outer part and a root. A triaxial fabric which is defined by three angularly disposed sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other yarn course set is bonded against the elements and defines all abrasion-resistant exposed surface of the elements. The tri-axial fabric also minimizes shearing stresses in the element due to improved tear resistance thereof. Such endless power transmission belts are not sub-ject to premature failure due to buckling and premature wear.
An endless power transmission belt and method for producing the same, are provided herein. The belt has a portion which has a plurality of spaced belt elements defined by alternating projections and recesses with each of the elements having an outer part and a root. A triaxial fabric which is defined by three angularly disposed sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other yarn course set is bonded against the elements and defines all abrasion-resistant exposed surface of the elements. The tri-axial fabric also minimizes shearing stresses in the element due to improved tear resistance thereof. Such endless power transmission belts are not sub-ject to premature failure due to buckling and premature wear.
Description
~his invention relates to endless power tran~nission k~lts.
Endless power tran~nission belts having outer portions provided with elements in the form of ribs, teeth, and the like have been proposed heretofore and it is known to cover these belt elements with fabric. How~
ever, when belts using fabric covered belt elements are operated in associated sheaves conslderable stresses are im~osed on ~he fabric causing buckling, premature wear, and often failure thereof usually followed by premature failure of -the associated belt.
In an effort to solve the above-m~ntioned failure problem, knitted fabrics have been proposed for -this purpose and an e~a~nple of such a fabric is disclosed in U.~. patent No. 3,381,20~.
~ kxwever, none of the previously proposed belts em,ploys a triaxial fabric which is abrasion-resistant and wear-resistant and has improved tear resistance.
It is an object of one aspect of this invention to pr.ovide a simple and econ~nical endless power trans}nission belt having outer surfaces thereof covered by a triaxial fabric.
An object of another aspect of this invention is to provide an endless pcwer transmission belt including a portion having a plurality of spaced belt elements defined by alternating projections and recesses wi~h each of the elements having an outer part and a root, a triaxial fabric being bonded against the elements to define an abrasion-resistant exposed surface of the elem~ ts andl~linimizing shear.ing stresses in each element due to improved tear resistance thereof.
An object of yet another aspect of the invention is to provide for ~onding the fabric against the ou-termost surface of the tension sec-tion or around the entire outer surface of the belt.
An object of still another aspect of this invention is to provide .
a belt of the character mentloned wherein each element is in the form of a continuous longitudinal rib extending in an endless path along the belt.
An object of another aspect of this invention is to provide a belt of the character mentioned whereln each belt element is in the form of a tooth disposed transverse the longitudinal axis of the belt.
By one broad aspect of this invention, an endless power transmis-sion belt is provided comprising, a portion having a plurality of spaced - belt elements defined by alternating projections and recesses, each of such elements having an outer part and a root, and a triaxial fabric bonded a-gainst the elements, and defining an abrasion-resistant exposed surface of the elemeDts, and defining an abrasion-resistant exposed surface of the ele-ments; the triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof; the triaxial fabric being defined by three angularly d:Lsplaced sets of paraLlel courses of yarn -Lnterwoven sllbstant:La]Ly to prevent slippage oE at least one yarn course set along any other yarn course set.
By one variant thereof, the triaxial fabric is disposed against the elements independently of any particular orientation of its yarn courses relative to the longitudinal axis of the belt.
~0 By another variant, the belt further includes a compression sec-tion, with the spaced belt elements defining the outer portion of the com-pression section.
By another variant, the belt further includes a load-carrying sec-tion adjoining the compression section at a location remote from the outer portion.
By a variation thereof, each element extends longitudinaLly of the endless path of the belt.
By another variation, each element has a substantially V-shaped cross-sectional configuration and is in the form of a rib.
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~ - 3 -By another variation, the belt ~urther includes tension section adjoining the load-carrying section, with the fabric also being bonded against the outermost surface of the tension section.
By a further variation, the fabric is honded against the entire outer surface of the belt.
By yet another variant, each element extends transverse the longitudinal~axis of said belt.
By a still further variant each element is in the form o~ a tooth which extends perpendicular to the longitudinal axis of the belt and extends completely across the belt.
By another aspect of this invention, an endless power transmission belt is provided comprising a tension section; a compression section; ancl a load-carrying section bonded between said tension and compression sections; the compression section having a plurality of spaced belt elements defined by alternating projections and recesses, each of the belt elements having an outer part and a root which is integral with adjoining parts of the compression section, and a -triaxial fabric bonded against the elements and defining an abrasion-resistant inside surface of the belt, the triaxial fabric a]so minimizing shearing stresses in each element due to improved tear resistance thereof, the triaxial fabric being defined by three angularly displaced sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other yarn course set.
By another aspect of the invention, a method is provided of making an endless power transmission belt having a tension section, a compression section, and a load-carrying section , bonded between said tension and compression sections with said compression section having a plurality of spaced belt elements defined by alternating projections and recesses, the improvement comprising the steps of: providing a triaxial fabric in the form of a pliable fabric said triaxial fabric being defined ~y three angularly displaced sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any oth`er yarn course set; and bonding said triaxial fabric against said elements to define an abrasion-resist~ant inside surface for said belt; said triaxial fabric also,mini-mizing shearing stresses in each element due to improved tear resistance thereof.
By a variant thereoE, the bonding step co~nprises:
disposing said fabria against said elements independently of any particular orientation of its individual yarn courses rel-ative to the longitudinal axis of said belt.
By a further variant, the improvement includes the step of bonding said triaxial fabric against the outermost surface of said tension section.
By a further variant, the improvement further includes the step of bonding such triaxial fabric against the entire outer surface of said belt.
In the accompanying drawings, Fig. 1 is a perspective view with parts in cross section, parts in elevation, and parts broken ~way illustrating one examplary embodiment of the belt of one aspect of this invention;
Fig. 2 is a fragmentary plan view of the triaxial fabric utilized on the belt of Fig. l;
Fig. 3 is a view similar to Fig. 1 illustrating a modified form of the belt of Fig. l;
~ ~ -.. I: l r~ ~ 4a -FIG. 4 is a view similar to ~IG. 1 illustrating another form of the belt of another aspect of this invention; and FIG. 5 is a view similar to FIG. 3 illustrating a n~dified form of the belt o~ FIG. 3.
REference is now ~ade to FIG. 1 of the drawing ~hich illustrates one exemplary e~bodiment of an endless powe]- transmission belt of one aspect of this invention ~hich is designated generally by the reference numeral 20. The bèlt 20, which is Xnown in the industry as a V-.ribbed belt, co~prises a tension section 21, a cc~pression section 22, and a load-carrying section 23 bonded between the tension and compression sections 21 and 22 respectively. The load-carrying section 23 may ccmprise any suitable load-carrying means; hGwever, in this example of this aspect of the .invention, the load-carrying section is in the form of a helically '1 ,, - 4b -F~
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wound load-carrying cord 24 which is surrounded by a cushion material or cusllion 25 of high resiliency in the form of a rubber. In the com-pleted belt 20 the cushion 25 is shown in the form of a unitary mass surrounding the helically wound load-carrying cord 24, The compression section 23 includes an innermost portion designated generally by the reference numeral 26. The portion 26 includes a plurality o belt elements eaeh designated by the reEorence numeral 27, and the eleolents 27 are defined by alternating proJeetions and reeesses as indieated at 30, for example.
Eaeh element 27 of the exemplary belt 20 is a continuous longitudinal element which extends about the entire endless belt path;
each element 27 is of uniform solid cross-sectional configuration throughout its endless path In addition, each element 27 has a sub-stantially V-shaped cross-sectional configuration and is thus in the form of a V-shaped rib 27.
Each of the elements or ribs 27 has a tip 31 and a root 32 which is integral with adjoining parts of the compression section and during operation of the belt 20 in associated sheaves, or the ]ike, sub-stantial stresses are imposed on the tip 31 of each element often causing cracking and premature failure of the elements 27, During operation oi the belt 20 the elements 27 are also subjected to sub-stantial wear and abrasion.
The belt 20 employs what will be referred to as a triaxial fabric 33 which is bonded against the elements 27 and defines the exposcd surface of such elements. The triaxial fabric 33 has improved tear resistance which minimizes tha shcaring stresses at the root of - 4c -each el~ment. In addition, because of special weave characteristics of certain types of triaxial fabric 33 such types may be abrasion or wear re-sistant and are preferabl~ employed m the belt of an aspect of this inven-tion.
The fabric 33 is preferably of the type disclosed in detail in United States Patent No. 3,44~,251; an example of such fabric as disclosed in the above patent is illustrated in FIG~ 2 of the drawing. The exemplary fabric 33 of FIG. 2 has a plurality of three sets of yarn courses, which for convenience are illustrated pf equal yarn size, and -the yarns of each set are disposed in parallel relation. The yarns of one set, depicted in solid black, will be referred to as the woof or "Z" yarns; the yarns of a second set, depicted by cross-hatching, will be referred to as the weft or "Y" yarns; and the yarns of the third set, depLcted by stippling, will be referred to as the warp or "X" yarn.
Although other types of trlclxial fabric may be employed, e.y.
those illustrated in the above mentioned patent and others kncwn in the art, ; the exemplary fabric 33 of FIG. 2 has been illustrated because of its ease of presentation.
The triaxial fabric has open spaced or pores between its various yarns as indicated at 34, for example, and such open spaces are uniformly placed throughout the abric and are such that they lend themselves to calendering~ frictioniny, and the li]ce w;th op-timum control to help control the characteristics of the overall fabric and the belt on which it is emr ployed. The fabric 33 may be bonded to associated belt elements e.g., the belt elements 27 utilizing any suitable technique kncwn in the art and may employ adjesive means at the interface of the fabric 33 and associated belt rbody cand such adhesive means is designated by the reference numeral 35. It will be appreclated that the adhesive means may be oE any suitable type employed in the art ror this purpose and may be applied in accordance with any technique kncwn in the art.
.. ,.. ,~ ,.. _ .,, ... . . ... _ . _ : ~ ~ -; In addition to covering ~he rlbs or elements 27, the triaxial fabric 33 may be provided on or define a smooth nonundulating surface of a belt. For example, triaxial fabric 33 may also be employed and ~-bonded to the outermost surface of the tension section 21 of tbe belt ~.
5 so that the finished balt 20 has triaxial fabric defining both its inside and outside surfaces.
The belt 40 which is shown in FIG. 3 is almost identical in construction to the belt 20. However, in this instance the fabric 33 is bonded to the entire outer surface of belt 40. This lends itself to ~
10 certain manufacturing m~.thods that may be utilized as an alternative ~' mcthod, ,, Ano~;her ùxemplary embodLmont of tlle belt structllre or belt of another aspect of ~is invention is illustrated in F'IG. 4 of ~le drawings.
~he belt illustrated in FIG. 4 is different than the belt 20 and is designa~
ted by the reEerence numeral 20A. l'he belt 20~ has a tension section 21~, a compression section 22A, and a load-carrying section 23A comprised of a ~,~
helically wound load-carrying cord 24A embedded in a polymeric matrix ~;
or cushion 25A. The belt 20A has a triaxial fabric top cover 33A defin-ing its outside surface, and cover 33A is similar to the top cover 33 20 employed on thc belt 20 oE FIG, 1.
The belt 20A is rcferrcd to as a toothcd or coegcd V-belt.
The principal diffcrencc between thc belt 20A and the bclt 20 is that the belt 20A instead of having elements in the form of longitudinally extending V-shaped ribs, has transversely extendine elements which will 25 be referred to as tceth and designated by reference numeral 27A. The elements or teeth 27A are disposed transversely of the loneitudinal axis of the belt 20A and preferably extend perpendicular to such longitudinal r axis. In a similar manner as previously described for the e]ements or V-shaped ribs 27 the tecth 27A are deElned by alternating pro3cctions and rccesses as shown at 30A.
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The teeth 27A form the outer portion 26A of the compression `~ 4;~' section 22A and each tooth 27A extends completely across the balt 20A 5j~
Each tooth27A has an outer tip 3~A and a root 31A, ad~acent teeth being separated by grooves 30A. The triaxial fabric 33A is bonded in position against thc teeth 27Aso that the fabric assures shearing stresses and - hence cracks at the root of each element 27A are kept at a minimu~.
Accordingly, the belt 20Aof this example also has triaxial fabric 33A
defining both its inside and outside surfaces. ii~;;s~
Ench tooth 27A illustrated in thc exemplary bell: 20A has an outer portlon which is frce of sharp eclges but has a substantially rec-tangulnr outline as shown at 37A. Ilowever, lt should be understood that the outer portion may be more rouncled and essentially semi-circular.
In addition, the inner surface 38Aof the grooves may also be more ~ .
rounded.
The belt 40A~ which is illustrated in FI(: 5, is identical in internal construction to the belt 20A. However, in this instance the fabric 33 is bonded to the entire outer surface oi belt 40A~ in order to permit fabrication of the belt by other n~3thod The compression section of each belt 20, 20A~40 and 40A is comprised of a plurality of spaced belt clements extencling outwarclly from the belt body, and defined by altcrnating proJcctions and recesses.
In the belts 20 and 40 such elemants are in the form Of longitudinal ribs 27 while in the belts 20A and 40A such elements are in the form of transverse teeth 27A. However, it will be appreciaced that, if desired, either ribs or teeth may be provided and defined as an integral part of a tension section of an associated belt in a similar manner; also, a double V-rlbbed belt or double cogged bclt may bs formed.
Except for thc load-carrying cord and the triaxial fabric thereof, the belts llave been shown by cross-hatching in the drawings as being made of polymeric material in the form of rubbcr. Ilowever, it r ~ ~ : ` ~ ~
.~ 5 ' ~
;.
will be appreeiated that instead of rubber each of such belts may be made of any suLtable synthetic plastic material known in the art, L
The tension seetion and eompression seetion of each belt dis- ~~~
elosed herein may eomprise one or more p1atform layers and each plat- ~
5 form layer may be of any type known in the art. ~urther, each of such _ sectioDs may be reinforced by any suitable means.
The triaxial fabric may be bonded to its belt body without eoncern for orientatlon of the various yarn courses thereof during the belt building process; yet beeause the fabrie employs three sets of - 10 yarns courses, any attempt to tear the fabrie results in applying tearing forces on a bias angle relative to at least two of the three sets of yarn eourses, It is well known that tear resistance of any fabrie on sueh a bias angle is eompnratively great.
The trinxial fabric may also be bonded to its belt body with L~
one of the yarn courses parallel to the longitudinal axis of the belt.
_ ._ In sueh instance the parallel yarn course serves to increase the tensile ~ _ .
strength or Lnextensibility of the belt with respect to sueh longitud-inal axis, Similarly, the triaxial fabric may be bonded to its belt ~ , body with one of the yarn courses transverse (preferably perpendicular) ~f~,.' ' to the longitudinal axis of such belt body and in this instance the parallel yarn course serves to increase the transverse ri6idity of its belt body.
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. -8-:, SUPPLEMENT~RY DISCLOS RE
The Principal Disclosure provided an endless power transmission ...... ... ............ ........ belt comprising a portion`~ahving a plurality of spaced belt elements defined by alternating projections and recesses, each of the elements having an outer part and a root, and a triaxial fabric bonded against the elements and defining an abrasion-resistant exposed surface of the elements, the triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof, the triaxial fabric being defined by three angularly displaced sets of parallel courses of yarn interwoven sub-: stantially to prevent slippage of at least one yarn~course set along any other yarn course set.
The Pr:incipal Disclosure also prov:ided an endless power transmis-s:Lon belt compr:Lsing a tens:l.on sect:Lon, a compress:lon st~ct.lon, a ].oad-carrying sect:Lon bonded between the tension and compression sections, the compression section having a plurality of spaced belt elements defined by ~ alternating projectLons and recesses, each of the belt elements having an outer part and a root which is integral with adjoining parts of the compres-sion section, and a triaxlal fabric bonded against the elements and defin-ing an abrasion-resistant inside surface of the belt, the triaxial fabric also mlnimi~l.ng shearing stresses i.n each e].ement due to improved tear re-. 20 sistance thereof, the triaxi.al fabric be:Lng de:Eined by three angu:Larly displaced sets of paralle]. courses of yarn interwoven substantially to pre-vent slippage of at least one yarn course set along any other yarn course set.
It is also well known in the endless power transmission belt art that, in an endless power transmission belt which has a compression section provided with load-transmitting teeth, there is substantial wear of such teeth. Numerous attempts have been made heretofore to provide strong teeth which are subject to minimum wear.
An object therefore of a broad aspect of the present invention as ~ ` .
j~ 3 provided by the present Supplementary Disclosure is to provide an improved endless power transmission belt wherein each belt element is in the form of a tooth disposed transverse the longitudinal axis of the belt.
An object of another aspect of thi~; invention as provided by the - Supplementary Disclosure i5 to provide a method of making an improved end-less power transmission belt.
An object of another aspect of this invention as provided by the present Supplementàry Disclosure is to provide an improved method of making an endless power transmission belt having a polymeric compression section provided with load-transmitting teeth of the character mentioned.
By one aspect of this invention as provided by the present Sup-plementary Disclosure an improvement is provided in an endless power trans-mission belt having a compression section provided with :Load--transmitting teeth defined by alternating projec~ions and recesses and a fabric bonded against and defining the outer portions of the teeth, the Lmprovement where-in: the fabrlc comprises a triaxial fabric def:Lned by ~hree angularly dis-placed sets of yarn interwoven substantially to prevent slippage of at leastone yarn course set along any other course set, as in claim SD23; whereby one of the three sets is substàntially protected by the two other yarn setsS the one yarn set providing reinforcement of the teeth after substantial wear of the two other yarn sets resulting in an lncreased service life for the belt-By a variant thereof, tl~e three sets of yarn courses are definedby a set of parallel X yarns disposed parallel to the longitudinal axis of the belt, by a set of parallel Y yarns, each disposed at an acute included angle measured clockwise relative to the X yarns, and by a set of parallel Z yarns, each disposed at an acute included angle measured counterclockwise relative to the X yarns.
By a further variant, the Y yarns deflne one yarn set, the Y
yarns being made of a synthetic plastic material and having improved structural strength.
.
By another variant, at least one set of the Y and the Z yarns is ~;- made of self-lubricating yarn filaments, thereby providing a self-lubricating action of the load-transmitting teeth.
By a further variant, the Y and the Z yarns are disposed with an included angle of 60~ therebetween.
By yet another variant, the Y yarns are disposed at the acute in-cluded angle with the X yarns ranging between 30 and 75~ and the Z yarns are disposed at thè~acute included angle with the X yarns ranging between 30 and 75.
By a further variant, the belt has a tension section and a load-carrying section, with the load-carrying SeCtiQn being made of a helically wound load-carrying cord.
By another variant, the tension section :Ls free of an outer cover.
By ano~.her aspect of this invention as prov:Lded by t~is Supplementary Disclosure an improvement is provided in an endless power transmission belt having a compression section provided with load-transmit-ting teeth defined by alternating projections and recesses and a fabric bonded against and defining the outer portions of the teeth, the improvement wherein: the fabric comprises a triaxial Eabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, whereby one of the three sets is substantially protected by the two other sets as in claim SD23;
wherein each of the sets of yarn courses is comprise& of a plurality of spaced parallel yarns and wherein each yarn of each set is defined by a plurality of side-by-side yarn strands; the one yarn set providing reinforcement of the teeth after substantial wear of the two other yarn sets, resulting in an increased service life of the belt.
~; v ~y a variant thereof, each of the spaced parallel yarns of each set is defined by two side-by-side yarn strands.
;'' j ~ - SD 11 -~. "' `
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By another aspect of this lnvention as provided by the present Supplementary Disclosure an improvement is provided in a method of making an endless power transmission belt having a tension section, a compression sec-tion, and a load-carrying section bonded between the tension and compression sections with the compression section having a plurality of spaced belt ele-ments defined by alternating projections and recesses, the improvement com-prising the steps of: providing a triaxial fabric in the form of a pliable fabric defined by three angularly displaced sets oE yarn interwoven sub-stantially to prevent slippage of at least one yarn course set along any lO other course set, with each set having an axis disposed at an acute angle with each other axis, each of the sets of yarn courses being comprised of a plurality of spaced parallel yarns and each yarn of each set being defined by a plurallty of side-by-side yarn strands; and bonding the trlaxlal fabric agalnst the elements to define an abraslon-resistant inside surface for the belt; the triaxial fabrlc also minimizing shearing stresses in each element due to improved tear resistance thereof.
By a variation thereof, the bonding step comprises disposing the fabric against the elements independently of any particular orientation of its individual yarn courses relative to the longitudinal axis of the belt.
By a further variation, the method includes the step of bonding the tri-axial fabric against the outermost surface oE the tension section.
By yet another variation, the method includes the step of bonding the ~r:Laxial fabric against the entire outer surface of the belt.
By still another aspect of this invention as provided by the present Supplementary Disclosure an improvement is provided in a method of making an endless power transmission belt having a polymeric compression section provided with load-transmitting teeth defined by alternating projec-tions and recesses, the improvement comyrising the steps of: providing a triaxial f~bric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any ~. ' .
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other course set whereby one of the three sets is substantially protected by the two other yarn sets, each of the sets of yarn courses being comprised of a plurality of spaced parallel yarns and each yarn of each set being de-fined by a plurality of side-by-side yarn strands; and bonding the triaxial fabric against the teeth to define the outer portion thereof as in claim SD23;
wherein the bonding step comprises the step of: disposing the yarn so that the one yarn set is protected by the two other yarn sets, and thereby provides rein-~forcement oE the teeth after substantial wear of the two other sets, resulting in an increased service life for the belt.
By a variation thereof, the providing step comprises: providing the triaxial fabric with each of the sets of yarn courscs comprised of a plurality of spaced parallel yarns, and wherein each yarn of each set is deflned by a plurality of side-by-side yarn strands.
By another variation, the bonding step comprises: coating the tri-axial fabric with a layer of polymeric material compatible with the polymer-ic material of the compression section, and then curing the layer, the com-pression section, and the belt to provide a simultaneous bonding and curing action.
By yet another variation, the providing step comprises: providing the three sets of yarn courses defined by a set of parallel X yarns disposed parallel to the longitudinal axis of the belt, by a set of parallel Y yarns, each disposed at an acute included angle measured clockwise relative to the X yarns, and by a set of parallel Z yarns each disposed at an acute in-cluded angle measured counterclockwise relatlve to the X yarns.
By a still further variation, the providing step comprises pro-; viding at least one set of the Y and the Z yarns made of self-lubricating yarn filaments, the filaments thereby providing a self-lubricating action of the load-transmltting teeth.
In drawings accompanying the present Supplementary Disclosure, FIG. 6 is a perspective view illustrating a drive syst~m employing i - SD 13 -~ .
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another exemplary embodiment of an endless power transmission belt of an aspect of the invention as provided by the present Supplementary Disclosure;
FIG. 7 is an enlarged side view of a straight top portion of the be].t of an aspect of the invention as provicled by the present Supplementary Disclosure as illustrated in FIG. 6 showing by symbolic representation a triaxial fabric bonded against and defining the outer portions of the load-transmitting teeth and by standard cross hatching showing a helically wound ' ~0 , ~ - SD 13 A -load-cclrryi~g cord thereo~ to highlight the location of such cord;
FIG~ 8 is a vi~ taken e~sentiall.y on the line 8-8 of FI~. 7 and illustra-ting only the three ~e~ of yarn courses of the trxaxlal ~cibric minus adjoinin~ structure while al~o sh~wing the ~ide edges of the b~lt and the l~ngitudinal axis o~ such balt.
FIG. 9 is a cro~s-sectional vi~w taken essentially on the line 9-9 of FIG. 7; and FIG. 10 i~ a cros3-sectional view t~ken essentially on the line 10-10 of FIG. 7.
Another e~emplary eLbodiment of an endle~s power transmission belt ~tructure or belt o~ an aspect o -~his invantion as provi~ed by the present Supplementary Discl~oure is illustrated in FIG~S. 6-10 of the drawings.
Such b~lt i~ -. ~0 ', ~' .
- designated generally by the reference numeral 20B. The belt 20B is often popularly referred to as a synchronous-type belt because it has belt ele-ments or teeth 27B which are in the form of load-transmitting teeth which - cooperate with toothed sheaves as will be described in more detail herein-- after. The teeth 27B are disposed perpendicular to the longitudinal axis 41B of the belt 20B~
The exemplary belt 20B is particularly adapted to be used in a drive system 42, as shown in FIG. 6, and such drive system may include a plurality of toothed sheaves including a toothed driving sheave 43 having teeth 44 therein and a toothed driven sheave 45 having teeth 46 therein with the transverse teeth 27B of the belt 20B meshing within grooves G provided between the teeth 44 and 46 of the sheaves 43 and 45 respectively as is known in the art. The toothed sheave 43 has a pair of side flanges 50 on opposite sides thereof and the flanges 50 prevent the belt 20B from slid-ing off the sheaves 43 and 45 during operation of the system 42. The driv-ing sheave 43 may be suitnbly operatively connected by a shaft 52 to a drive motor 53 while the sheave 45 may be suitably operatively connected by a shaft 54 to a suitable load S5 which is to be rotated. The shafts 52 and 54 as well as motor 53 and load 55 are shown by schematic representa-tions. With this construction and arrangement the toothed belt 20B is em-ployed to rotate toothed sheave 45 in a synchronous manner with rotation of toothed sheave 43 employing the teeth 27B of belt 20B.
The belt 20B comprises a tension section 21B, a compression section 22B, and a load-carrying section 23B in the form of a helically wound load-carrying cord 24B. The cord 24B may be surrounded by a suitable cushion material in a similar manner as disclosed earlier in connection with other embodiments of the belt of this invention and the load-carrying cord 24B may be of any suitable type employed in the art for this purpose.
The load-transmitting teeth 27B comprising the compression section 22B of the belt 20B are preferably made of a suitable polymeric material shown in the drawings by cross-hatching as rubber and triaxial fabric 33B
bonded against and defining the outer portions of such teeth 27B. The load-transmitting teeth 27B are defined by alternating projections and recesses as indicated at 30B, for exan~ple, and triaxial fabric 33B upon being bonded in position also defines the exposed outer surfaces of the teeth.
- Referring now to FIG. 8 of the drawings, it :Ls seerl that the tri-axial fabrlc 33B is comprLsed of a plurality of three sets of yarn courses which as ln previous embodiments and for convenience are Illustrated of equal yarn si~e and the yarns of each set are disposied in parallel relation.
- In a similar manner as described in cOnnection with FIG. 2, the yarns of one set, depicted as solid black, will be referred to as the woof or "Z" yarns;
the yarns of a second set, depicted by cross-hatching, will be referred to as the weft or "Y" yarns; and the yarns of the third set, depicted by stip-pling, will be referred to as the warp or "X" yarns. From the illustration of FIG. 8 lt is seen that one (the set of Y yarns) oE the three sets of parallel yarns is , substantially protected by the other two yarn sets. Stated otherwise, the set of Y yarns is substantially protected by X and Z yarns as shown at a pair of typical locations 56B. for example. With this construction the set of Y yarns provides reinforcement for the teeth 27B after substantial wear of the other two sets (the Z and X sets) whlch results in an increased ser-vice life for the belt 20B.
The triaxial fabric 33B has each oE its three sets of yarn courses comprised of parallel yarns; and, each yarn of each set is defined by a plurality of side-by-side yarn strands. For example, each of the Y yarns is defined by a pair of side-by-side yarn strands 60B, each of the Z yarns is defined by a pair of side-by-side yarn strands 61B, and each of the X
yarns is defined by a pair of side-by-side yarn strands 62B.
In the belt 20B the triaxial fabric 33B is provided so that the parallel X yarns are each disposed approx;mately parallel to the lopgitudin-al axLs 41B of such belt; and9 Ln t:his example cach oE the X yalns is dis-posed at a slight angle to such longitudinal axis 41B and as shown at 63B.
The parallel Y yarns are each disposed at an acute included angle 64B
measured clockwise relative to the X yarns. The parallel Z yarns are each disposed at an acute included angle 65B measured co~mterclockwise relative to the X yarns.
The Y and Z yarns are preferably disposed with an included angle 66B of approximately 60 therebetween. However, the Y yarns may be disposed so that the included angle 64B may range between 30 and 75 and the Z yarns may be disposed so that the included angle 65B may range between 30 and 75o.
The Y yarns of fabric 33Et ma~ be made of any sl~able high stren~th material used in the ~qavin~ art. E~or example, the Y yarns may be made of a high ~trength ~ynthetic plastic material, ~erehy such Y yarns pro-vide the belt 20B with improved structural strer.gth. It t~ill also be appreci-ated that one eat o the comparatively mDre ~o~ed X a~d æ ya~ns (Z yarns in thi~ example) ~ay be made of self-lubricatinc~ yarn fib~rs or filament~ where-by the load-tran~itting tee~h 27B are ~elf-lubricated. Any ~uitable mater-ial may be used to provide ~he sel~-lubricatin~ action wher~by -the yarns may be made of carbonaceous ma~erial~, polypropy:Lene, or a ~uita~le 1uorocarbon resin. For exa~ple, a yarn made of a ~luorocarbon re~qin and sold under the registered trademark of "Teflon~' by the Fluorocarkon~ Divis.ion o E.I. duPont "
deNbmours and Co., INc., Wilmington, Delaware, 19898 may be used in making:
triaxial ~abric 33B.
In addition to tha oon~ructions previously degcrihed, the -tr.iaxial fabric used to make one or m~re portions of ~ario~s belts of aspects of this invention as p w vided the ~ho pre8ent Supplementary Disclosure ~ay be made ,:
of ~arns c~mprised of any ~uitable ~aterial such as filaments or fibers of cotton, or the like. Similarly, ~uch fabric may be made of synt~etic plastic filament~ or fiber~ or blend~ o natur~l and syn~hetic plastic filaments or f~bers.
Each he~lt disclo~ed herein may be made in accordance ~lith any sultable manu~aaturing p~ooe~ known in the art. Further, the bonding of ~he ~riaxial fabrlc pre~erably o~m~rise~ ODatin~ suL~h Ecabric with a layer of pol~meric m~terial compai~ble with the polymeric ~aterial of the particu-lar section againgt which the tria~ial fabric i~ bondedi. For e~ample, ~or ~hie tcothedibelt 20~ ha ~ ig loaid-~ran3mattinig or load-carrying teeth 27B
thP tric~xical fabric 33~ i~ preferably coated ~ri~h a polymeric material (ruDbsr) which is ca~patible with the p~lymeric m~terial ~al~o rubber) o~
~he co~pre~sion s~ctio~ 22B ~l~raupon the erltire belt is then cured tG
:~ .
$~
thereby cure the ooat~d layer o po.lym~ric ~atexial, the compression section, and the o~erall belt 20~ Thi9 technique provides a simultaneous bonding and curiny action. After curingl each belt is suitably cooled in accordance with ariy suitable technique .known m ~e art~
~ The triaxlal ~abria e~ployed to mak~ each exemplary belt of aspects of this invention as provided ~y ~hs present ';upplementary Disclosure has op~n spaces or pores uniformly and symmetrically disposed t~ oughout and such spaces and abric enable tha fabria to be calender~d, frictioned, ski~n coated, knife aoated, and the like. A~cordingly, fabric 33 has spaces as indicated at 34 in FIG. 2 and fabric 33~ ha~ spaces as indicate~ at 34B, for example, in FIG. 8.
The ten~ion section and ccmpression section of each belt of aspects of the invention a~ provided by the pre~ent Supplementary Di~closure di~closed herein may compri~e one or ~ore platform laye~xs and each platorm layer may be of any typa known in the art. FuLther, ea~h of such YeCtiOnS
may be reinforced by an suitable mean~.
~ ference ha8 been ma~e in this disclosure to the ~act that the triaxia~ fabric i~ iso~ro~ic in character. Thi~ is achieved becau~e m the manufacture of an as~ociated belt the fabric is stretched so that any crimp is substantially remaved from th2 variou3 yarns wherçby all of such yarns c~ssume a substantially ~traight configuration. The o~nstruction, si~e, and angulc~r disposal of the various set~ of yclrn~ of the triaxial fabric result in tne load-elon~ation characteri~tics oE such fabric being sub-stantially equal regardle~s of the angle at which a load may be trans-m~tted bo the triaxial fa~ric, i.e., the fabric assumes its isotropic char-act&r.
;D 19
Endless power tran~nission belts having outer portions provided with elements in the form of ribs, teeth, and the like have been proposed heretofore and it is known to cover these belt elements with fabric. How~
ever, when belts using fabric covered belt elements are operated in associated sheaves conslderable stresses are im~osed on ~he fabric causing buckling, premature wear, and often failure thereof usually followed by premature failure of -the associated belt.
In an effort to solve the above-m~ntioned failure problem, knitted fabrics have been proposed for -this purpose and an e~a~nple of such a fabric is disclosed in U.~. patent No. 3,381,20~.
~ kxwever, none of the previously proposed belts em,ploys a triaxial fabric which is abrasion-resistant and wear-resistant and has improved tear resistance.
It is an object of one aspect of this invention to pr.ovide a simple and econ~nical endless power trans}nission belt having outer surfaces thereof covered by a triaxial fabric.
An object of another aspect of this invention is to provide an endless pcwer transmission belt including a portion having a plurality of spaced belt elements defined by alternating projections and recesses wi~h each of the elements having an outer part and a root, a triaxial fabric being bonded against the elements to define an abrasion-resistant exposed surface of the elem~ ts andl~linimizing shear.ing stresses in each element due to improved tear resistance thereof.
An object of yet another aspect of the invention is to provide for ~onding the fabric against the ou-termost surface of the tension sec-tion or around the entire outer surface of the belt.
An object of still another aspect of this invention is to provide .
a belt of the character mentloned wherein each element is in the form of a continuous longitudinal rib extending in an endless path along the belt.
An object of another aspect of this invention is to provide a belt of the character mentioned whereln each belt element is in the form of a tooth disposed transverse the longitudinal axis of the belt.
By one broad aspect of this invention, an endless power transmis-sion belt is provided comprising, a portion having a plurality of spaced - belt elements defined by alternating projections and recesses, each of such elements having an outer part and a root, and a triaxial fabric bonded a-gainst the elements, and defining an abrasion-resistant exposed surface of the elemeDts, and defining an abrasion-resistant exposed surface of the ele-ments; the triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof; the triaxial fabric being defined by three angularly d:Lsplaced sets of paraLlel courses of yarn -Lnterwoven sllbstant:La]Ly to prevent slippage oE at least one yarn course set along any other yarn course set.
By one variant thereof, the triaxial fabric is disposed against the elements independently of any particular orientation of its yarn courses relative to the longitudinal axis of the belt.
~0 By another variant, the belt further includes a compression sec-tion, with the spaced belt elements defining the outer portion of the com-pression section.
By another variant, the belt further includes a load-carrying sec-tion adjoining the compression section at a location remote from the outer portion.
By a variation thereof, each element extends longitudinaLly of the endless path of the belt.
By another variation, each element has a substantially V-shaped cross-sectional configuration and is in the form of a rib.
,~
~ - 3 -By another variation, the belt ~urther includes tension section adjoining the load-carrying section, with the fabric also being bonded against the outermost surface of the tension section.
By a further variation, the fabric is honded against the entire outer surface of the belt.
By yet another variant, each element extends transverse the longitudinal~axis of said belt.
By a still further variant each element is in the form o~ a tooth which extends perpendicular to the longitudinal axis of the belt and extends completely across the belt.
By another aspect of this invention, an endless power transmission belt is provided comprising a tension section; a compression section; ancl a load-carrying section bonded between said tension and compression sections; the compression section having a plurality of spaced belt elements defined by alternating projections and recesses, each of the belt elements having an outer part and a root which is integral with adjoining parts of the compression section, and a -triaxial fabric bonded against the elements and defining an abrasion-resistant inside surface of the belt, the triaxial fabric a]so minimizing shearing stresses in each element due to improved tear resistance thereof, the triaxial fabric being defined by three angularly displaced sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other yarn course set.
By another aspect of the invention, a method is provided of making an endless power transmission belt having a tension section, a compression section, and a load-carrying section , bonded between said tension and compression sections with said compression section having a plurality of spaced belt elements defined by alternating projections and recesses, the improvement comprising the steps of: providing a triaxial fabric in the form of a pliable fabric said triaxial fabric being defined ~y three angularly displaced sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any oth`er yarn course set; and bonding said triaxial fabric against said elements to define an abrasion-resist~ant inside surface for said belt; said triaxial fabric also,mini-mizing shearing stresses in each element due to improved tear resistance thereof.
By a variant thereoE, the bonding step co~nprises:
disposing said fabria against said elements independently of any particular orientation of its individual yarn courses rel-ative to the longitudinal axis of said belt.
By a further variant, the improvement includes the step of bonding said triaxial fabric against the outermost surface of said tension section.
By a further variant, the improvement further includes the step of bonding such triaxial fabric against the entire outer surface of said belt.
In the accompanying drawings, Fig. 1 is a perspective view with parts in cross section, parts in elevation, and parts broken ~way illustrating one examplary embodiment of the belt of one aspect of this invention;
Fig. 2 is a fragmentary plan view of the triaxial fabric utilized on the belt of Fig. l;
Fig. 3 is a view similar to Fig. 1 illustrating a modified form of the belt of Fig. l;
~ ~ -.. I: l r~ ~ 4a -FIG. 4 is a view similar to ~IG. 1 illustrating another form of the belt of another aspect of this invention; and FIG. 5 is a view similar to FIG. 3 illustrating a n~dified form of the belt o~ FIG. 3.
REference is now ~ade to FIG. 1 of the drawing ~hich illustrates one exemplary e~bodiment of an endless powe]- transmission belt of one aspect of this invention ~hich is designated generally by the reference numeral 20. The bèlt 20, which is Xnown in the industry as a V-.ribbed belt, co~prises a tension section 21, a cc~pression section 22, and a load-carrying section 23 bonded between the tension and compression sections 21 and 22 respectively. The load-carrying section 23 may ccmprise any suitable load-carrying means; hGwever, in this example of this aspect of the .invention, the load-carrying section is in the form of a helically '1 ,, - 4b -F~
:`
wound load-carrying cord 24 which is surrounded by a cushion material or cusllion 25 of high resiliency in the form of a rubber. In the com-pleted belt 20 the cushion 25 is shown in the form of a unitary mass surrounding the helically wound load-carrying cord 24, The compression section 23 includes an innermost portion designated generally by the reference numeral 26. The portion 26 includes a plurality o belt elements eaeh designated by the reEorence numeral 27, and the eleolents 27 are defined by alternating proJeetions and reeesses as indieated at 30, for example.
Eaeh element 27 of the exemplary belt 20 is a continuous longitudinal element which extends about the entire endless belt path;
each element 27 is of uniform solid cross-sectional configuration throughout its endless path In addition, each element 27 has a sub-stantially V-shaped cross-sectional configuration and is thus in the form of a V-shaped rib 27.
Each of the elements or ribs 27 has a tip 31 and a root 32 which is integral with adjoining parts of the compression section and during operation of the belt 20 in associated sheaves, or the ]ike, sub-stantial stresses are imposed on the tip 31 of each element often causing cracking and premature failure of the elements 27, During operation oi the belt 20 the elements 27 are also subjected to sub-stantial wear and abrasion.
The belt 20 employs what will be referred to as a triaxial fabric 33 which is bonded against the elements 27 and defines the exposcd surface of such elements. The triaxial fabric 33 has improved tear resistance which minimizes tha shcaring stresses at the root of - 4c -each el~ment. In addition, because of special weave characteristics of certain types of triaxial fabric 33 such types may be abrasion or wear re-sistant and are preferabl~ employed m the belt of an aspect of this inven-tion.
The fabric 33 is preferably of the type disclosed in detail in United States Patent No. 3,44~,251; an example of such fabric as disclosed in the above patent is illustrated in FIG~ 2 of the drawing. The exemplary fabric 33 of FIG. 2 has a plurality of three sets of yarn courses, which for convenience are illustrated pf equal yarn size, and -the yarns of each set are disposed in parallel relation. The yarns of one set, depicted in solid black, will be referred to as the woof or "Z" yarns; the yarns of a second set, depicted by cross-hatching, will be referred to as the weft or "Y" yarns; and the yarns of the third set, depLcted by stippling, will be referred to as the warp or "X" yarn.
Although other types of trlclxial fabric may be employed, e.y.
those illustrated in the above mentioned patent and others kncwn in the art, ; the exemplary fabric 33 of FIG. 2 has been illustrated because of its ease of presentation.
The triaxial fabric has open spaced or pores between its various yarns as indicated at 34, for example, and such open spaces are uniformly placed throughout the abric and are such that they lend themselves to calendering~ frictioniny, and the li]ce w;th op-timum control to help control the characteristics of the overall fabric and the belt on which it is emr ployed. The fabric 33 may be bonded to associated belt elements e.g., the belt elements 27 utilizing any suitable technique kncwn in the art and may employ adjesive means at the interface of the fabric 33 and associated belt rbody cand such adhesive means is designated by the reference numeral 35. It will be appreclated that the adhesive means may be oE any suitable type employed in the art ror this purpose and may be applied in accordance with any technique kncwn in the art.
.. ,.. ,~ ,.. _ .,, ... . . ... _ . _ : ~ ~ -; In addition to covering ~he rlbs or elements 27, the triaxial fabric 33 may be provided on or define a smooth nonundulating surface of a belt. For example, triaxial fabric 33 may also be employed and ~-bonded to the outermost surface of the tension section 21 of tbe belt ~.
5 so that the finished balt 20 has triaxial fabric defining both its inside and outside surfaces.
The belt 40 which is shown in FIG. 3 is almost identical in construction to the belt 20. However, in this instance the fabric 33 is bonded to the entire outer surface of belt 40. This lends itself to ~
10 certain manufacturing m~.thods that may be utilized as an alternative ~' mcthod, ,, Ano~;her ùxemplary embodLmont of tlle belt structllre or belt of another aspect of ~is invention is illustrated in F'IG. 4 of ~le drawings.
~he belt illustrated in FIG. 4 is different than the belt 20 and is designa~
ted by the reEerence numeral 20A. l'he belt 20~ has a tension section 21~, a compression section 22A, and a load-carrying section 23A comprised of a ~,~
helically wound load-carrying cord 24A embedded in a polymeric matrix ~;
or cushion 25A. The belt 20A has a triaxial fabric top cover 33A defin-ing its outside surface, and cover 33A is similar to the top cover 33 20 employed on thc belt 20 oE FIG, 1.
The belt 20A is rcferrcd to as a toothcd or coegcd V-belt.
The principal diffcrencc between thc belt 20A and the bclt 20 is that the belt 20A instead of having elements in the form of longitudinally extending V-shaped ribs, has transversely extendine elements which will 25 be referred to as tceth and designated by reference numeral 27A. The elements or teeth 27A are disposed transversely of the loneitudinal axis of the belt 20A and preferably extend perpendicular to such longitudinal r axis. In a similar manner as previously described for the e]ements or V-shaped ribs 27 the tecth 27A are deElned by alternating pro3cctions and rccesses as shown at 30A.
.' !i~
The teeth 27A form the outer portion 26A of the compression `~ 4;~' section 22A and each tooth 27A extends completely across the balt 20A 5j~
Each tooth27A has an outer tip 3~A and a root 31A, ad~acent teeth being separated by grooves 30A. The triaxial fabric 33A is bonded in position against thc teeth 27Aso that the fabric assures shearing stresses and - hence cracks at the root of each element 27A are kept at a minimu~.
Accordingly, the belt 20Aof this example also has triaxial fabric 33A
defining both its inside and outside surfaces. ii~;;s~
Ench tooth 27A illustrated in thc exemplary bell: 20A has an outer portlon which is frce of sharp eclges but has a substantially rec-tangulnr outline as shown at 37A. Ilowever, lt should be understood that the outer portion may be more rouncled and essentially semi-circular.
In addition, the inner surface 38Aof the grooves may also be more ~ .
rounded.
The belt 40A~ which is illustrated in FI(: 5, is identical in internal construction to the belt 20A. However, in this instance the fabric 33 is bonded to the entire outer surface oi belt 40A~ in order to permit fabrication of the belt by other n~3thod The compression section of each belt 20, 20A~40 and 40A is comprised of a plurality of spaced belt clements extencling outwarclly from the belt body, and defined by altcrnating proJcctions and recesses.
In the belts 20 and 40 such elemants are in the form Of longitudinal ribs 27 while in the belts 20A and 40A such elements are in the form of transverse teeth 27A. However, it will be appreciaced that, if desired, either ribs or teeth may be provided and defined as an integral part of a tension section of an associated belt in a similar manner; also, a double V-rlbbed belt or double cogged bclt may bs formed.
Except for thc load-carrying cord and the triaxial fabric thereof, the belts llave been shown by cross-hatching in the drawings as being made of polymeric material in the form of rubbcr. Ilowever, it r ~ ~ : ` ~ ~
.~ 5 ' ~
;.
will be appreeiated that instead of rubber each of such belts may be made of any suLtable synthetic plastic material known in the art, L
The tension seetion and eompression seetion of each belt dis- ~~~
elosed herein may eomprise one or more p1atform layers and each plat- ~
5 form layer may be of any type known in the art. ~urther, each of such _ sectioDs may be reinforced by any suitable means.
The triaxial fabric may be bonded to its belt body without eoncern for orientatlon of the various yarn courses thereof during the belt building process; yet beeause the fabrie employs three sets of - 10 yarns courses, any attempt to tear the fabrie results in applying tearing forces on a bias angle relative to at least two of the three sets of yarn eourses, It is well known that tear resistance of any fabrie on sueh a bias angle is eompnratively great.
The trinxial fabric may also be bonded to its belt body with L~
one of the yarn courses parallel to the longitudinal axis of the belt.
_ ._ In sueh instance the parallel yarn course serves to increase the tensile ~ _ .
strength or Lnextensibility of the belt with respect to sueh longitud-inal axis, Similarly, the triaxial fabric may be bonded to its belt ~ , body with one of the yarn courses transverse (preferably perpendicular) ~f~,.' ' to the longitudinal axis of such belt body and in this instance the parallel yarn course serves to increase the transverse ri6idity of its belt body.
.. j ' .
~
~,Jc .
. -8-:, SUPPLEMENT~RY DISCLOS RE
The Principal Disclosure provided an endless power transmission ...... ... ............ ........ belt comprising a portion`~ahving a plurality of spaced belt elements defined by alternating projections and recesses, each of the elements having an outer part and a root, and a triaxial fabric bonded against the elements and defining an abrasion-resistant exposed surface of the elements, the triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof, the triaxial fabric being defined by three angularly displaced sets of parallel courses of yarn interwoven sub-: stantially to prevent slippage of at least one yarn~course set along any other yarn course set.
The Pr:incipal Disclosure also prov:ided an endless power transmis-s:Lon belt compr:Lsing a tens:l.on sect:Lon, a compress:lon st~ct.lon, a ].oad-carrying sect:Lon bonded between the tension and compression sections, the compression section having a plurality of spaced belt elements defined by ~ alternating projectLons and recesses, each of the belt elements having an outer part and a root which is integral with adjoining parts of the compres-sion section, and a triaxlal fabric bonded against the elements and defin-ing an abrasion-resistant inside surface of the belt, the triaxial fabric also mlnimi~l.ng shearing stresses i.n each e].ement due to improved tear re-. 20 sistance thereof, the triaxi.al fabric be:Lng de:Eined by three angu:Larly displaced sets of paralle]. courses of yarn interwoven substantially to pre-vent slippage of at least one yarn course set along any other yarn course set.
It is also well known in the endless power transmission belt art that, in an endless power transmission belt which has a compression section provided with load-transmitting teeth, there is substantial wear of such teeth. Numerous attempts have been made heretofore to provide strong teeth which are subject to minimum wear.
An object therefore of a broad aspect of the present invention as ~ ` .
j~ 3 provided by the present Supplementary Disclosure is to provide an improved endless power transmission belt wherein each belt element is in the form of a tooth disposed transverse the longitudinal axis of the belt.
An object of another aspect of thi~; invention as provided by the - Supplementary Disclosure i5 to provide a method of making an improved end-less power transmission belt.
An object of another aspect of this invention as provided by the present Supplementàry Disclosure is to provide an improved method of making an endless power transmission belt having a polymeric compression section provided with load-transmitting teeth of the character mentioned.
By one aspect of this invention as provided by the present Sup-plementary Disclosure an improvement is provided in an endless power trans-mission belt having a compression section provided with :Load--transmitting teeth defined by alternating projec~ions and recesses and a fabric bonded against and defining the outer portions of the teeth, the Lmprovement where-in: the fabrlc comprises a triaxial fabric def:Lned by ~hree angularly dis-placed sets of yarn interwoven substantially to prevent slippage of at leastone yarn course set along any other course set, as in claim SD23; whereby one of the three sets is substàntially protected by the two other yarn setsS the one yarn set providing reinforcement of the teeth after substantial wear of the two other yarn sets resulting in an lncreased service life for the belt-By a variant thereof, tl~e three sets of yarn courses are definedby a set of parallel X yarns disposed parallel to the longitudinal axis of the belt, by a set of parallel Y yarns, each disposed at an acute included angle measured clockwise relative to the X yarns, and by a set of parallel Z yarns, each disposed at an acute included angle measured counterclockwise relative to the X yarns.
By a further variant, the Y yarns deflne one yarn set, the Y
yarns being made of a synthetic plastic material and having improved structural strength.
.
By another variant, at least one set of the Y and the Z yarns is ~;- made of self-lubricating yarn filaments, thereby providing a self-lubricating action of the load-transmitting teeth.
By a further variant, the Y and the Z yarns are disposed with an included angle of 60~ therebetween.
By yet another variant, the Y yarns are disposed at the acute in-cluded angle with the X yarns ranging between 30 and 75~ and the Z yarns are disposed at thè~acute included angle with the X yarns ranging between 30 and 75.
By a further variant, the belt has a tension section and a load-carrying section, with the load-carrying SeCtiQn being made of a helically wound load-carrying cord.
By another variant, the tension section :Ls free of an outer cover.
By ano~.her aspect of this invention as prov:Lded by t~is Supplementary Disclosure an improvement is provided in an endless power transmission belt having a compression section provided with load-transmit-ting teeth defined by alternating projections and recesses and a fabric bonded against and defining the outer portions of the teeth, the improvement wherein: the fabric comprises a triaxial Eabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, whereby one of the three sets is substantially protected by the two other sets as in claim SD23;
wherein each of the sets of yarn courses is comprise& of a plurality of spaced parallel yarns and wherein each yarn of each set is defined by a plurality of side-by-side yarn strands; the one yarn set providing reinforcement of the teeth after substantial wear of the two other yarn sets, resulting in an increased service life of the belt.
~; v ~y a variant thereof, each of the spaced parallel yarns of each set is defined by two side-by-side yarn strands.
;'' j ~ - SD 11 -~. "' `
. . .
.
By another aspect of this lnvention as provided by the present Supplementary Disclosure an improvement is provided in a method of making an endless power transmission belt having a tension section, a compression sec-tion, and a load-carrying section bonded between the tension and compression sections with the compression section having a plurality of spaced belt ele-ments defined by alternating projections and recesses, the improvement com-prising the steps of: providing a triaxial fabric in the form of a pliable fabric defined by three angularly displaced sets oE yarn interwoven sub-stantially to prevent slippage of at least one yarn course set along any lO other course set, with each set having an axis disposed at an acute angle with each other axis, each of the sets of yarn courses being comprised of a plurality of spaced parallel yarns and each yarn of each set being defined by a plurallty of side-by-side yarn strands; and bonding the trlaxlal fabric agalnst the elements to define an abraslon-resistant inside surface for the belt; the triaxial fabrlc also minimizing shearing stresses in each element due to improved tear resistance thereof.
By a variation thereof, the bonding step comprises disposing the fabric against the elements independently of any particular orientation of its individual yarn courses relative to the longitudinal axis of the belt.
By a further variation, the method includes the step of bonding the tri-axial fabric against the outermost surface oE the tension section.
By yet another variation, the method includes the step of bonding the ~r:Laxial fabric against the entire outer surface of the belt.
By still another aspect of this invention as provided by the present Supplementary Disclosure an improvement is provided in a method of making an endless power transmission belt having a polymeric compression section provided with load-transmitting teeth defined by alternating projec-tions and recesses, the improvement comyrising the steps of: providing a triaxial f~bric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any ~. ' .
.
~'$1~
other course set whereby one of the three sets is substantially protected by the two other yarn sets, each of the sets of yarn courses being comprised of a plurality of spaced parallel yarns and each yarn of each set being de-fined by a plurality of side-by-side yarn strands; and bonding the triaxial fabric against the teeth to define the outer portion thereof as in claim SD23;
wherein the bonding step comprises the step of: disposing the yarn so that the one yarn set is protected by the two other yarn sets, and thereby provides rein-~forcement oE the teeth after substantial wear of the two other sets, resulting in an increased service life for the belt.
By a variation thereof, the providing step comprises: providing the triaxial fabric with each of the sets of yarn courscs comprised of a plurality of spaced parallel yarns, and wherein each yarn of each set is deflned by a plurality of side-by-side yarn strands.
By another variation, the bonding step comprises: coating the tri-axial fabric with a layer of polymeric material compatible with the polymer-ic material of the compression section, and then curing the layer, the com-pression section, and the belt to provide a simultaneous bonding and curing action.
By yet another variation, the providing step comprises: providing the three sets of yarn courses defined by a set of parallel X yarns disposed parallel to the longitudinal axis of the belt, by a set of parallel Y yarns, each disposed at an acute included angle measured clockwise relative to the X yarns, and by a set of parallel Z yarns each disposed at an acute in-cluded angle measured counterclockwise relatlve to the X yarns.
By a still further variation, the providing step comprises pro-; viding at least one set of the Y and the Z yarns made of self-lubricating yarn filaments, the filaments thereby providing a self-lubricating action of the load-transmltting teeth.
In drawings accompanying the present Supplementary Disclosure, FIG. 6 is a perspective view illustrating a drive syst~m employing i - SD 13 -~ .
.
f~
another exemplary embodiment of an endless power transmission belt of an aspect of the invention as provided by the present Supplementary Disclosure;
FIG. 7 is an enlarged side view of a straight top portion of the be].t of an aspect of the invention as provicled by the present Supplementary Disclosure as illustrated in FIG. 6 showing by symbolic representation a triaxial fabric bonded against and defining the outer portions of the load-transmitting teeth and by standard cross hatching showing a helically wound ' ~0 , ~ - SD 13 A -load-cclrryi~g cord thereo~ to highlight the location of such cord;
FIG~ 8 is a vi~ taken e~sentiall.y on the line 8-8 of FI~. 7 and illustra-ting only the three ~e~ of yarn courses of the trxaxlal ~cibric minus adjoinin~ structure while al~o sh~wing the ~ide edges of the b~lt and the l~ngitudinal axis o~ such balt.
FIG. 9 is a cro~s-sectional vi~w taken essentially on the line 9-9 of FIG. 7; and FIG. 10 i~ a cros3-sectional view t~ken essentially on the line 10-10 of FIG. 7.
Another e~emplary eLbodiment of an endle~s power transmission belt ~tructure or belt o~ an aspect o -~his invantion as provi~ed by the present Supplementary Discl~oure is illustrated in FIG~S. 6-10 of the drawings.
Such b~lt i~ -. ~0 ', ~' .
- designated generally by the reference numeral 20B. The belt 20B is often popularly referred to as a synchronous-type belt because it has belt ele-ments or teeth 27B which are in the form of load-transmitting teeth which - cooperate with toothed sheaves as will be described in more detail herein-- after. The teeth 27B are disposed perpendicular to the longitudinal axis 41B of the belt 20B~
The exemplary belt 20B is particularly adapted to be used in a drive system 42, as shown in FIG. 6, and such drive system may include a plurality of toothed sheaves including a toothed driving sheave 43 having teeth 44 therein and a toothed driven sheave 45 having teeth 46 therein with the transverse teeth 27B of the belt 20B meshing within grooves G provided between the teeth 44 and 46 of the sheaves 43 and 45 respectively as is known in the art. The toothed sheave 43 has a pair of side flanges 50 on opposite sides thereof and the flanges 50 prevent the belt 20B from slid-ing off the sheaves 43 and 45 during operation of the system 42. The driv-ing sheave 43 may be suitnbly operatively connected by a shaft 52 to a drive motor 53 while the sheave 45 may be suitably operatively connected by a shaft 54 to a suitable load S5 which is to be rotated. The shafts 52 and 54 as well as motor 53 and load 55 are shown by schematic representa-tions. With this construction and arrangement the toothed belt 20B is em-ployed to rotate toothed sheave 45 in a synchronous manner with rotation of toothed sheave 43 employing the teeth 27B of belt 20B.
The belt 20B comprises a tension section 21B, a compression section 22B, and a load-carrying section 23B in the form of a helically wound load-carrying cord 24B. The cord 24B may be surrounded by a suitable cushion material in a similar manner as disclosed earlier in connection with other embodiments of the belt of this invention and the load-carrying cord 24B may be of any suitable type employed in the art for this purpose.
The load-transmitting teeth 27B comprising the compression section 22B of the belt 20B are preferably made of a suitable polymeric material shown in the drawings by cross-hatching as rubber and triaxial fabric 33B
bonded against and defining the outer portions of such teeth 27B. The load-transmitting teeth 27B are defined by alternating projections and recesses as indicated at 30B, for exan~ple, and triaxial fabric 33B upon being bonded in position also defines the exposed outer surfaces of the teeth.
- Referring now to FIG. 8 of the drawings, it :Ls seerl that the tri-axial fabrlc 33B is comprLsed of a plurality of three sets of yarn courses which as ln previous embodiments and for convenience are Illustrated of equal yarn si~e and the yarns of each set are disposied in parallel relation.
- In a similar manner as described in cOnnection with FIG. 2, the yarns of one set, depicted as solid black, will be referred to as the woof or "Z" yarns;
the yarns of a second set, depicted by cross-hatching, will be referred to as the weft or "Y" yarns; and the yarns of the third set, depicted by stip-pling, will be referred to as the warp or "X" yarns. From the illustration of FIG. 8 lt is seen that one (the set of Y yarns) oE the three sets of parallel yarns is , substantially protected by the other two yarn sets. Stated otherwise, the set of Y yarns is substantially protected by X and Z yarns as shown at a pair of typical locations 56B. for example. With this construction the set of Y yarns provides reinforcement for the teeth 27B after substantial wear of the other two sets (the Z and X sets) whlch results in an increased ser-vice life for the belt 20B.
The triaxial fabric 33B has each oE its three sets of yarn courses comprised of parallel yarns; and, each yarn of each set is defined by a plurality of side-by-side yarn strands. For example, each of the Y yarns is defined by a pair of side-by-side yarn strands 60B, each of the Z yarns is defined by a pair of side-by-side yarn strands 61B, and each of the X
yarns is defined by a pair of side-by-side yarn strands 62B.
In the belt 20B the triaxial fabric 33B is provided so that the parallel X yarns are each disposed approx;mately parallel to the lopgitudin-al axLs 41B of such belt; and9 Ln t:his example cach oE the X yalns is dis-posed at a slight angle to such longitudinal axis 41B and as shown at 63B.
The parallel Y yarns are each disposed at an acute included angle 64B
measured clockwise relative to the X yarns. The parallel Z yarns are each disposed at an acute included angle 65B measured co~mterclockwise relative to the X yarns.
The Y and Z yarns are preferably disposed with an included angle 66B of approximately 60 therebetween. However, the Y yarns may be disposed so that the included angle 64B may range between 30 and 75 and the Z yarns may be disposed so that the included angle 65B may range between 30 and 75o.
The Y yarns of fabric 33Et ma~ be made of any sl~able high stren~th material used in the ~qavin~ art. E~or example, the Y yarns may be made of a high ~trength ~ynthetic plastic material, ~erehy such Y yarns pro-vide the belt 20B with improved structural strer.gth. It t~ill also be appreci-ated that one eat o the comparatively mDre ~o~ed X a~d æ ya~ns (Z yarns in thi~ example) ~ay be made of self-lubricatinc~ yarn fib~rs or filament~ where-by the load-tran~itting tee~h 27B are ~elf-lubricated. Any ~uitable mater-ial may be used to provide ~he sel~-lubricatin~ action wher~by -the yarns may be made of carbonaceous ma~erial~, polypropy:Lene, or a ~uita~le 1uorocarbon resin. For exa~ple, a yarn made of a ~luorocarbon re~qin and sold under the registered trademark of "Teflon~' by the Fluorocarkon~ Divis.ion o E.I. duPont "
deNbmours and Co., INc., Wilmington, Delaware, 19898 may be used in making:
triaxial ~abric 33B.
In addition to tha oon~ructions previously degcrihed, the -tr.iaxial fabric used to make one or m~re portions of ~ario~s belts of aspects of this invention as p w vided the ~ho pre8ent Supplementary Disclosure ~ay be made ,:
of ~arns c~mprised of any ~uitable ~aterial such as filaments or fibers of cotton, or the like. Similarly, ~uch fabric may be made of synt~etic plastic filament~ or fiber~ or blend~ o natur~l and syn~hetic plastic filaments or f~bers.
Each he~lt disclo~ed herein may be made in accordance ~lith any sultable manu~aaturing p~ooe~ known in the art. Further, the bonding of ~he ~riaxial fabrlc pre~erably o~m~rise~ ODatin~ suL~h Ecabric with a layer of pol~meric m~terial compai~ble with the polymeric ~aterial of the particu-lar section againgt which the tria~ial fabric i~ bondedi. For e~ample, ~or ~hie tcothedibelt 20~ ha ~ ig loaid-~ran3mattinig or load-carrying teeth 27B
thP tric~xical fabric 33~ i~ preferably coated ~ri~h a polymeric material (ruDbsr) which is ca~patible with the p~lymeric m~terial ~al~o rubber) o~
~he co~pre~sion s~ctio~ 22B ~l~raupon the erltire belt is then cured tG
:~ .
$~
thereby cure the ooat~d layer o po.lym~ric ~atexial, the compression section, and the o~erall belt 20~ Thi9 technique provides a simultaneous bonding and curiny action. After curingl each belt is suitably cooled in accordance with ariy suitable technique .known m ~e art~
~ The triaxlal ~abria e~ployed to mak~ each exemplary belt of aspects of this invention as provided ~y ~hs present ';upplementary Disclosure has op~n spaces or pores uniformly and symmetrically disposed t~ oughout and such spaces and abric enable tha fabria to be calender~d, frictioned, ski~n coated, knife aoated, and the like. A~cordingly, fabric 33 has spaces as indicated at 34 in FIG. 2 and fabric 33~ ha~ spaces as indicate~ at 34B, for example, in FIG. 8.
The ten~ion section and ccmpression section of each belt of aspects of the invention a~ provided by the pre~ent Supplementary Di~closure di~closed herein may compri~e one or ~ore platform laye~xs and each platorm layer may be of any typa known in the art. FuLther, ea~h of such YeCtiOnS
may be reinforced by an suitable mean~.
~ ference ha8 been ma~e in this disclosure to the ~act that the triaxia~ fabric i~ iso~ro~ic in character. Thi~ is achieved becau~e m the manufacture of an as~ociated belt the fabric is stretched so that any crimp is substantially remaved from th2 variou3 yarns wherçby all of such yarns c~ssume a substantially ~traight configuration. The o~nstruction, si~e, and angulc~r disposal of the various set~ of yclrn~ of the triaxial fabric result in tne load-elon~ation characteri~tics oE such fabric being sub-stantially equal regardle~s of the angle at which a load may be trans-m~tted bo the triaxial fa~ric, i.e., the fabric assumes its isotropic char-act&r.
;D 19
Claims (22)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An endless power transmission belt comprising, a portion having a plurality of spaced belt elements defined by alternating projections and recesses, each of said elements having an outer part and a root, and a triaxial fabric bonded against said elements and defining an abrasion-resistant ex-posed surface of said elements, said triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof, said triaxial fabric being defined by three angularly displaced sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other yarn course set.
2. An endless power transmission belt as set forth in claim i wherein said triaxial fabric is disposed against said elements independently of any particular orientation of its yarn courses relative to the longitudinal axis of said belt.
3. An endless power transmission belt as set forth in claim 1, and further including: compression section, said spaced belt elements defining the outer portion of said com-pression section.
4. An endless power transmission belt as set forth in claim 3, and further including: a load-carrying section adjoining said compression section at a location remote from said outer portion.
5. An endless power transmission belt as set forth in claim 4, wherein each element extends longitudinally of the endless path of said belt.
6. An endless power transmission belt as set forth in claim 5, wherein each element has a substantially V-shaped cross-sectional configuration and is in the form of a rib.
7. An endless power transmission belt as set forth in claim 4, and further including: tension section adjoining said load-carrying section, said fabric also being bonded against the outermost surface of said tension section.
8. An endless power transmission belt as set forth in claim 7 wherein said fabric is bonded against the entire outer surface of said belt.
9. An endless power transmission belt as set forth in claim 1 wherein each element extends transverse the longitudinal axis of said belt.
10. An endless power transmission belt as set forth in claim 1 wherein each element is in the form of a tooth which extends perpendicular to the longitudinal axis of said belt and extends completely across said belt.
11. An endless power transmission belt comprising: a tension section; a compression section; a load-carrying section bonded between said tension and compression sections;
said compression section having a plurality of spaced belt elements defined by alternating projections and recesses, each of said belt elements having an outer part and a root which is integral with adjoining parts of said compression section, and a triaxial fabric bonded against said elements and defining an abrasion-resistant inside surface of said belt, said triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof, said triaxial fabric being defined by three angularly displaced sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other yarn course set.
said compression section having a plurality of spaced belt elements defined by alternating projections and recesses, each of said belt elements having an outer part and a root which is integral with adjoining parts of said compression section, and a triaxial fabric bonded against said elements and defining an abrasion-resistant inside surface of said belt, said triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof, said triaxial fabric being defined by three angularly displaced sets of parallel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other yarn course set.
12. An endless power transmission belt as set forth in claim 11 wherein said triaxial fabric is disposed against said ele-ments independently of any particular orientation of its in-dividual yarn courses relative to the longitudinal axis of said belt.
13. An endless power transmission belt as set forth in claim 12 wherein each element extends in an endless path.
14. An endless power transmission belt as set forth in claim 13 wherein each element has a substantially V-shaped cross-sec-tional configuration and is in the form of a rib.
15. An endless power transmission belt as set forth in claim 13 wherein each element extends transverse the longitudinal axis of said belt.
16. An endless power transmission belt as set forth in claim 15 wherein each element is in the form of a tooth.
17. An endless power transmission belt as set forth in claim 11 wherein said fabric is also bonded against the outermost surface of said tension section.
18. An endless power transmission belt as set forth in claim 11 wherein said fabric is bonded against the entire outer surface of said belt.
19. In a method of making an endless power transmission belt having a tension section, a compression section, and a load-carrying section bonded between said tension and compression sections with said compression section having a plurality of spaced belt elements defined by alternating projections and recesses, the improvement comprising the steps of: providing a triaxial fabric in the form of a pliable fabric said triaxial fabric being defined by three angularly displaced sets of par-allel courses of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other yarn course set; and bonding said triaxial fabric against said elements to define an abrasion-resistant inside surface for said belt; said triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof.
20. In a method as set forth in claim 19, the further improve-ment in which said bonding step comprises: disposing said fabric against said elements independently of any particular orient-ation of its individual yarn courses relative to the longitudinal axis of said belt.
21. In a method as set forth in claim 19, the further improve-ment comprising: the step of bonding said triaxial fabric against the outermost surface of said tension section.
22. In a method as set forth in claim 19, the further improve-ment comprising: the step of bonding such triaxial fabric against the entire outer surface of said belt.
CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE
SD23. In an endless power transmission belt having a compres-sion section provided with load-transmitting teeth defined by alternating projections and recesses and a fabric bonded against and defining the outer portions of said teeth, the improvement wherein said fabric comprises a triaxial fabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, said triaxial fabric defining an abrasion-resistant exposed surface of said elements and also minimizing shearing stresses in each element; whereby one of said three sets is substantially protected by the two other yarn sets, said one yarn set providing reinforcement of said teeth after substantial wear of said two other yarn sets resulting in an increased service life for said belt.
SD24. In an endless power transmission belt as set forth in claim SD23, the further improvement wherein: said three sets of yarn courses are defined by a set of parallel X yarns disposed approximately parallel to the longitudinal axis of said belt;
by a set of parallel Y yarns, each disposed at an acute included angle measured clockwise relative to said X yarns; and by a set of parallel Z yarns, each disposed at an acute included angle measured counterclockwise relative to said X yarns.
SD25. In an endless power transmission belt as set forth in claim SD24, the further improvement wherein: said Y and said Z
yarns are disposed with an included angle of 60° therebetween.
SD26. In an endless power transmission belt as set forth in claim SD 24, the further improvement wherein: said Y yarns are disposed at said acute included angle with said X yarns ranging between 30° and 75°.
SD27. In an endless power transmission belt as set forth in claim SD24, the further improvement wherein: said belt has a tension section and a load-carrying section, said load-carry-ing section being made of a helically wound load-carrying cord.
SD28. In an endless power transmission belt as set forth in claim SD25, the further improvement wherein: said tension section is free of an outer cover.
SD29. In an endless power transmission belt having a compres-sion section provided with load-transmitting teeth defined by alternating projections and recesses and a fabric bonded against and defining the outer portions of said teeth, the improvement wherein: said fabric comprises a triaxial fabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, whereby one of said three sets is substantially protected by the two other yarn sets, said triaxial fabrid defin-ing an abrasion-resistant exposed surface of said elements and also minimizing shearing stresses in each element; wherein each of said sets of yarn courses is comprised of a plurality of spaced parallel yarns; and wherein each yarn of each set is defined by a plurality of side-by-side yarn strands; said one yarn set providing reinforcement of said teeth after substantial wear of said two other yarn sets, resulting in an increased service life of said belt.
SD30. In an endless power transmission belt as set forth in claim SD 29, the further improvement wherein: each of said spaced parallel yarns of each set is defined by two side by-side yarn strands.
SD31. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein: said three sets of yarn courses are defined by a set of parallel X yarns dis-posed parallel to the longitudinal axis of said belt; by a set of aprallel Y yarns, each disposed at an acute included angle measured clockwise relative to said X yarns; and by a set of parallel Z yarns, each disposed at an acute included angle measured counterclockwise relative to said X yarns.
SD32. In an endless power transmission belt as set forth in claim SD30, the further improvement wherein: said Y yarns define said one yarn set, said Y yarns being made of a synthetic plastic material and having improved structural strength.
SD33. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein: at least one set of Y and said Z yarns is made of self-lubricating yarn filaments, thereby providing a self-lubricating action of said load transmitting teeth.
SD34. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein: said Y and said Z
yarns are disposed with an included angle of 60° therebetween.
SD35. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein: said Y yarns are disposed at said acute included angle with said X yarns ranging between 30° and 75°; and wherein said Z yarns are disposed at said acute included angle with said X yarns ranging between 30°
and 75°.
SD36. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein said belt has a tension section and a load-carrying section, said load-carry-ing section being made of a helically wound load-carrying cord.
SD37. In an endless power transmission belt as set forth in claim SD36, the further improvement wherein: said tension section is free of an outer cover.
SD38. In a method of making an endless power transmission belt having a tension section, a compression section, and a load-carrying section beonded between said tension and com-pression sections, with said compression section having a plur-ality of spaced belt elements defined by alternating projections and recesses, the improvement comprising the steps of: providing a triaxial fabric in the form of a pliable fabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, with each set having an axis disposed at an acute angle with each other axis, each of said sets of yarn courses being comprised of a plurality of spaced parallel yarns and each yarn of each set being defined by a plurality of side-by-side yarn strands; and bonding said triaxial fabric against said elements to define an abrasion-resistant inside surface of said belt; said triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof.
SD39. In a method as set forth in claim SD38, the further improvement in which said bonding step comprises: disposing said fabric against said elements independently of any partic-ular orientation of its individual yarn courses relative to the longitudinal axis of said belt.
SD40. In a method as set forth in claim SD38, the further improvement comprising the step of: bonding said triaxial fabric against the outermost surface of said tension section.
SD41. In a method as set forth in claim SD38, the further improvement comprising the step of: bonding said triaxial fabric against the entire outer surface of said belt.
SD42. In a method of making an endless power transmission belt having a polymeric compression section provided with load-transmitting teeth defined by alternating projections and recesses, the improvement comprising the steps of: providing a triaxial fabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, whereby one of said three sets is substantially protected by the two other yarn sets, each of said sets of yarn courses being comprised of a plurality of spaced parallel yarns and each yarn of each set being defined by a plurality of side-by-side yarn strands;
and bonding said triaxial fabric against said teeth to define the outer portion thereof, said triaxial fabric defining an abrasion-resistant exposed surface of said elements and also minimizing shearing stresses in each element; wherein said bonding step comprises the step of: disposing said yarn so that said one yarn set is protected by said two other yarn sets, and thereby provides reinforcement of said teeth after substantial wear of said two other sets resulting in an increased service life for said belt.
SD43. In a method as set forth in claim SD42, the further improvement in which said providing step comprises: providing said triaxial fabric with each of said sets of yarn courses comprised of a plurality of spaced parallel yarns, and wherein each yarn of each set is defined by a plurality of side-by-side yarn strands.
SD44. In a method as set forth in claim SD42, the further improvement in which said bonding step comprises: coating said triaxial fabric with a layer of polymeric material compatible with the polymeric material of said compression section; and curing said layer, said compression section, and said belt to provide a simultaneous bonding and curing action.
SD45. In a method as set forth in claim SD42, the further improvement in which said providing step comprises: providing said three sets of yarn courses defined by a set of aprallel X yarns disposed parallel to the longitudinal axis of said belt, by a set of parallel Y yarns, each disposed at an acute included angle measured clockwise relative to said X yarns, and by a set of parallel Z yarns, each disposed at an acute included angle measured counterclockwise relative to said X yarns.
SD46. In a method as set forth in claim SD45, the further improvement in which said providing step comprises: providing at least one set of said Y and said Z yarns made of self-lubricating yarn filaments, said filaments thereby providing a self-lubricating action of said load-transmitting teeth.
CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE
SD23. In an endless power transmission belt having a compres-sion section provided with load-transmitting teeth defined by alternating projections and recesses and a fabric bonded against and defining the outer portions of said teeth, the improvement wherein said fabric comprises a triaxial fabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, said triaxial fabric defining an abrasion-resistant exposed surface of said elements and also minimizing shearing stresses in each element; whereby one of said three sets is substantially protected by the two other yarn sets, said one yarn set providing reinforcement of said teeth after substantial wear of said two other yarn sets resulting in an increased service life for said belt.
SD24. In an endless power transmission belt as set forth in claim SD23, the further improvement wherein: said three sets of yarn courses are defined by a set of parallel X yarns disposed approximately parallel to the longitudinal axis of said belt;
by a set of parallel Y yarns, each disposed at an acute included angle measured clockwise relative to said X yarns; and by a set of parallel Z yarns, each disposed at an acute included angle measured counterclockwise relative to said X yarns.
SD25. In an endless power transmission belt as set forth in claim SD24, the further improvement wherein: said Y and said Z
yarns are disposed with an included angle of 60° therebetween.
SD26. In an endless power transmission belt as set forth in claim SD 24, the further improvement wherein: said Y yarns are disposed at said acute included angle with said X yarns ranging between 30° and 75°.
SD27. In an endless power transmission belt as set forth in claim SD24, the further improvement wherein: said belt has a tension section and a load-carrying section, said load-carry-ing section being made of a helically wound load-carrying cord.
SD28. In an endless power transmission belt as set forth in claim SD25, the further improvement wherein: said tension section is free of an outer cover.
SD29. In an endless power transmission belt having a compres-sion section provided with load-transmitting teeth defined by alternating projections and recesses and a fabric bonded against and defining the outer portions of said teeth, the improvement wherein: said fabric comprises a triaxial fabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, whereby one of said three sets is substantially protected by the two other yarn sets, said triaxial fabrid defin-ing an abrasion-resistant exposed surface of said elements and also minimizing shearing stresses in each element; wherein each of said sets of yarn courses is comprised of a plurality of spaced parallel yarns; and wherein each yarn of each set is defined by a plurality of side-by-side yarn strands; said one yarn set providing reinforcement of said teeth after substantial wear of said two other yarn sets, resulting in an increased service life of said belt.
SD30. In an endless power transmission belt as set forth in claim SD 29, the further improvement wherein: each of said spaced parallel yarns of each set is defined by two side by-side yarn strands.
SD31. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein: said three sets of yarn courses are defined by a set of parallel X yarns dis-posed parallel to the longitudinal axis of said belt; by a set of aprallel Y yarns, each disposed at an acute included angle measured clockwise relative to said X yarns; and by a set of parallel Z yarns, each disposed at an acute included angle measured counterclockwise relative to said X yarns.
SD32. In an endless power transmission belt as set forth in claim SD30, the further improvement wherein: said Y yarns define said one yarn set, said Y yarns being made of a synthetic plastic material and having improved structural strength.
SD33. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein: at least one set of Y and said Z yarns is made of self-lubricating yarn filaments, thereby providing a self-lubricating action of said load transmitting teeth.
SD34. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein: said Y and said Z
yarns are disposed with an included angle of 60° therebetween.
SD35. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein: said Y yarns are disposed at said acute included angle with said X yarns ranging between 30° and 75°; and wherein said Z yarns are disposed at said acute included angle with said X yarns ranging between 30°
and 75°.
SD36. In an endless power transmission belt as set forth in claim SD29, the further improvement wherein said belt has a tension section and a load-carrying section, said load-carry-ing section being made of a helically wound load-carrying cord.
SD37. In an endless power transmission belt as set forth in claim SD36, the further improvement wherein: said tension section is free of an outer cover.
SD38. In a method of making an endless power transmission belt having a tension section, a compression section, and a load-carrying section beonded between said tension and com-pression sections, with said compression section having a plur-ality of spaced belt elements defined by alternating projections and recesses, the improvement comprising the steps of: providing a triaxial fabric in the form of a pliable fabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, with each set having an axis disposed at an acute angle with each other axis, each of said sets of yarn courses being comprised of a plurality of spaced parallel yarns and each yarn of each set being defined by a plurality of side-by-side yarn strands; and bonding said triaxial fabric against said elements to define an abrasion-resistant inside surface of said belt; said triaxial fabric also minimizing shearing stresses in each element due to improved tear resistance thereof.
SD39. In a method as set forth in claim SD38, the further improvement in which said bonding step comprises: disposing said fabric against said elements independently of any partic-ular orientation of its individual yarn courses relative to the longitudinal axis of said belt.
SD40. In a method as set forth in claim SD38, the further improvement comprising the step of: bonding said triaxial fabric against the outermost surface of said tension section.
SD41. In a method as set forth in claim SD38, the further improvement comprising the step of: bonding said triaxial fabric against the entire outer surface of said belt.
SD42. In a method of making an endless power transmission belt having a polymeric compression section provided with load-transmitting teeth defined by alternating projections and recesses, the improvement comprising the steps of: providing a triaxial fabric defined by three angularly displaced sets of yarn interwoven substantially to prevent slippage of at least one yarn course set along any other course set, whereby one of said three sets is substantially protected by the two other yarn sets, each of said sets of yarn courses being comprised of a plurality of spaced parallel yarns and each yarn of each set being defined by a plurality of side-by-side yarn strands;
and bonding said triaxial fabric against said teeth to define the outer portion thereof, said triaxial fabric defining an abrasion-resistant exposed surface of said elements and also minimizing shearing stresses in each element; wherein said bonding step comprises the step of: disposing said yarn so that said one yarn set is protected by said two other yarn sets, and thereby provides reinforcement of said teeth after substantial wear of said two other sets resulting in an increased service life for said belt.
SD43. In a method as set forth in claim SD42, the further improvement in which said providing step comprises: providing said triaxial fabric with each of said sets of yarn courses comprised of a plurality of spaced parallel yarns, and wherein each yarn of each set is defined by a plurality of side-by-side yarn strands.
SD44. In a method as set forth in claim SD42, the further improvement in which said bonding step comprises: coating said triaxial fabric with a layer of polymeric material compatible with the polymeric material of said compression section; and curing said layer, said compression section, and said belt to provide a simultaneous bonding and curing action.
SD45. In a method as set forth in claim SD42, the further improvement in which said providing step comprises: providing said three sets of yarn courses defined by a set of aprallel X yarns disposed parallel to the longitudinal axis of said belt, by a set of parallel Y yarns, each disposed at an acute included angle measured clockwise relative to said X yarns, and by a set of parallel Z yarns, each disposed at an acute included angle measured counterclockwise relative to said X yarns.
SD46. In a method as set forth in claim SD45, the further improvement in which said providing step comprises: providing at least one set of said Y and said Z yarns made of self-lubricating yarn filaments, said filaments thereby providing a self-lubricating action of said load-transmitting teeth.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US82458077A | 1977-08-15 | 1977-08-15 | |
| US824,580 | 1977-08-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1108889A true CA1108889A (en) | 1981-09-15 |
Family
ID=25241767
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA309,231A Expired CA1108889A (en) | 1977-08-15 | 1978-08-14 | Endless power transmission belt, method of making same, and drive system using same |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS5810610B2 (en) |
| CA (1) | CA1108889A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51102412A (en) * | 1975-09-08 | 1976-09-09 | Matsushita Electric Ind Co Ltd | SHINGOSHORI HOSHIKI |
| CA1112909A (en) * | 1978-01-23 | 1981-11-24 | Robert E. Wetzel | Endless power transmission belt, method of making same, and drive system using same |
| JP6949784B2 (en) * | 2018-07-02 | 2021-10-13 | 三ツ星ベルト株式会社 | V-ribbed belt and its manufacturing method |
-
1978
- 1978-08-14 JP JP9897678A patent/JPS5810610B2/en not_active Expired
- 1978-08-14 CA CA309,231A patent/CA1108889A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5810610B2 (en) | 1983-02-26 |
| JPS5431850A (en) | 1979-03-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |