Note: Descriptions are shown in the official language in which they were submitted.
3~
This invention relates to improved ~dle~s power
transmission belt construc~ions, a~ well as to methods
of making such belt construction
It ls known in the art ~o provide an endless
power transmission belt construc~ion having power tra~s-
mitting contact faces, and comprising an a~lal tension-
ing means, a plurality of lateral stiffaning means
carried by the tensioning m~ans, and ~ric~ion material
carried by at lea6t one of the tensioning m~ans or stiff-
ening means, with the tensioning means and the stlffen-
ing mean~ being fonmed of ma~rial that provide~ an
axial and lateral stiffne~ in excess of that normally
15 provided by polymeric friction materîal that normally
forms ~he main body of a belt constnlction that i8 re-
in~orced with such a tensioning means and stiffening
means. Furthermore, the friction material may have a
first portion thereof disposed on the means to define
the contac~ faces thereof, and a remaining portion
thereof disposed on th~ me~ns to at least assist in
securing th~ first portion to the means.
For example, see the following two United S~ates
Patents:
(1) U.S. Patent No. 4,078,443 - Warner et al
~2) U.5. Pa~ent No. 4,108,012 Warner et al
~1
3~5~
J
~ 2 --
It appears that the power trans~isslon belts of
item (1) above have axial tensioning means and la~eral
stiffening means, which are either formed as a homo-
geneous one-pie~e strueture, or are separately formed
and subseque~tly securad together, and which are em-
bedded within a polymeric friction materi~l that normal-
ly form8 the main body of the belt eonstructions, while
the tensioning means and stiffening means reinforce
the same. It also appears that the belt constructions
in item (2) above each have the latcral stiffening means
formed separate from the axial tensioning means while
being ~ecured thereto, with a~ least ~he axial tension-
ing means being embedded in polymeric friction material
that forms the main body of the belt construction.
It is also known to provide me~allic lateral
stiffening means for a belt construction.
For example, see the following U.S. Patent:
(3) U.S, Patent No. 4,177,687 - Russ, Sr.
IL is also known to provide an all metallic bel~O
For example, see the following U.S. Patent:
(4) U.S. Patent No. 3,949,621 - Beusink et al
Disclosure of the Inventi~n
It is one feature of this invention to provide an
improved endless power transmisslon belt construction
having power transmitting contact faces.
It is believed, according to the teachings of
this invention, that an endless power transmission belt
~ '7~6
construction can be provided by merely providing a
"backbone structure" comprising an a~cial tensioning
means and a plurality of lateral stiffening means
carried by the tensioning means tWith the means being
formed of material that provides an axial and lateral
stiffness in excess o that normally provided by poly-
meric friction material that normally fonms ~he main
body of the beLt construction that is reinforced with
such a tensioning means and stiEfening means, such as
in the aforement~oned U.S. Patent to Warner e~ al, No.
4,078,443), and ~he~ u~ilizing such "backbone structurel'
as the main body o~ the belt construction itself by
either merely applying the fric~ion material at the
power transmitting contact faces of the belt construc-
tion, 80 that the friction material only defines ~hscontact faces whlle the "backbone struc~ure" defines
all other exposed areas of the belt construction, or by
merely applying a relatively thin layer of the friction
material to the "backbone structure" at the power ~rans-
mltting contact faces of the belt construction, so thatthe friction material defines the contact faces, and
at other parts of the "backbone structure" to at least
assist in securin~ ~he friction material thereto, where-
by the "backbone structure" defines substantially all
of the material of the belt construction.
Thus, it is believed that while the U.S. Patents
to Warner et al, No. 4,078,443 and No. 4,108,012,
~ ~ ~ 3 ~ S ~
provide a "backbone struc~ure", the patentees did not
appreciate the fact that that "backbone struc~ure"
could be utilized as the belt construction itself, and
that the fric~ion m~terial need not form the main body
part of the belt construction as in such patents, and
that the riction ma~erial need only be applied to the
contact aces of the power transmission belt to define
only those contact faces thereoE, while the "backbone
structure" defines all other exposed areas of the belt
construction as pro~ided by applicant's inven~ion in
order to reduce the heat of operation of the resulting
belt construction, as will be hereinafter 8et forth.
Nor did the above-referenced patentees appreciate the
fact that the "backbone structure" could be utilized
a~ the bel~ construc~ion itself, and that ~he friction
ma~erial need no~ form the main body part of the belt
construction as in such patents, and that the friction
material need only be applied in a relatively thin
layer to the "backbone structure" at the contact faces
of the power transmission belt to deEine those contact
faces thereo, and to other parts to secure ~he layers
thereto, whereby the "backbone struct-ure" defines sub-
stantially all the m~terial of the belt construction as
provided by applicant's invention in order to again re-
duce the heat o operation of the resulting belt con-
struction, as will be hereinaf~er set forth.
Pursuan~ to one aspect of this in~ention, there is
~2:~3'7S6
pro~ided an endless power transmission belt cons~ruc-
tion having power transmitting ontact faces, and com-
prising an axial tensioning means, a plurality of
lateral stiffening means which are carried by said
S tensioning means, and friction material carried by at
least one of said tensioning means and said stiffening
means; said tensioning means and sa:id stifening means
are formed oE polymeric material that provides an
axial and lateral stiffness in excess of that normally
provided by polymeric friction material that normally
forms ~he main body of a belt construction that is ra-
inforced with such a tensioning mean~ and stiffening
means; said stiffening means and said tensioning means
are Eormed of the same material and compri.se a one-
piece construction; the improvement wherein said fric-
tion material is loca~ed only at said contact faces
and thereby defines only said contact faces of said
belt construction, while said tensioning means and said
stiffening mear.s deine all other exposed areas of said
belt construction.
Pursuant to another aspect of this invention,
there is provided an endless power transmission belt
construction having power transmitting contact faces,
and comprising an axial tensioning means, a plurality
of lateral s~iffening means which are carried by said
ten~ioning means~ and friction material, such as poly-
meric material, which is carried by said means; said
~2~3~6
-- 6 --
tensioning means and said stiffening means are formed
of material ~hat provides an a~ial and lateral stif-
ness in excess of that normally provided by polymeric
friction material that noxmally iorms the main body
of a belt construction tha~ is reinforced with such a
tensioning means and stiffening means; the friction
material has a firs~ portion thereof disposed on said
means ~o define said contact faces thereof, and has a
remaining portion ~hereof disposed on said mQans to
at leas~ assist in ~qecuring said first portion to said
means; the improvemen~ wherein the thickness of said
~irst portion o~ said friction material is relatively
thin, and the thickness of said remaining portion is
no thicker than the thickness of said first portlon,
whereby a substantially large amount of said belt con-
struction comprises said material of said tensioning
means and said stiffening means, and a substantially
small amount of said belt construction comprises said
riction material.
Accordingly, it is an object of this invention
to provide improved endless power transmission belt
eonstructions having one or more of the novel fea~ures
of this invention as set orth above or hereinafter
shown or described~
Another obj ect of this invention is to providP
method of making such endless power transmission belt
constructions, the methods of this invention having one
~ Z~L3'7S~
-- 7 --
or more of the novel features of this invention as setfor~h above or hereinaf ter shown or described.
~ri~f De~L~ Lf the Drawings
The features o~ the invention, and i~s technical
advantages, can be seen from the following description
of preferred embodiments, together wi~h the claims and
the accompanying drawings, in which:
FIG. 1 is a fragmentary perspective view of
one embodiment of the endless power transmission bel~
construction of this invention;
FIG. 2 is a fragmentary side vièw of the
belt cons~ruction of FIG. l;
FIG. 3 is an enlarged cross-sectional view
taken on line 3-3 of FIG. l;
FIG. 4 is a fragmentary side view of an-
other embodiment of the bel~ construction o this in-
vention;
FIG. 5 is a fragmentary side view of an-
other embodiment o~ the belt construction of this in-
ventlon;
FIG. 6 is an enlarged cross-sectional view
taken on line 6-6 of FIG. 5;
FIG. 7 is a fragmentary perspective view
of another embodiment of the belt ~onstruction of this
invention;
FIG. 8 is a Eragmentary perspective view
of a further embodiment of ~he endl~s power
~Z~3~
- 8 -
transmission bel~ construction of this invention;
FIG. 9 is a fragmentar~ side view cf the
belt construction of FIG. 8;
FIG. lOA is an enlarged cross-sectional
view taken on line lOA-lOA of FIG. 8;
FIG. lOB is an enlarged cross-sectional
view taken on line lOB-lOB of FIG. 8;
FIG, ll is a fragmentary side view of an-
other embodiment of the belt construction of this in-
vention;
FIG. 12 is a fragmentary side view o
another embodiment of the belt construction of this
invention;
FIG. 13A is an enlarged cross-sectional
view taken on lina 13A-13A of FXG. 12;
FIG. ].3B is an enlarged cross-sectional
view taken on line 13B-13B of FIG. 12; and
FIG. 14 is an enlarged ~ragmentary cross-
sectional view of another embodiment of the belt con-
struction of this inven~ion.
Best Modes for Carrying Out the Invention
__
While the various features oE this invention
are hereina~ter illustrated and described as pro-
viding power transmission belt constructions~ such as
a V-belt construction for a variable pulley drive, a
toothed belt construction for timing or synchronous
purposes, etc., it is to be understood ~ha~ the
:~2~3~75~
various features of this invention can be utiliz~d
singly or in various combinations thereof to pro-
vide belt constructions for other purposes.
Therefore, this invention is not to be limited
to only ~he embodiments illustrated in ~he drawings,
because the drawings are merely utili~ed to illustrate
some of the wide variety of uses of this inven~ion.
Referring now to FIGS. 1-3, one lmproved endless
power transmission belt construction of this invention
is generally indicated by the reference numeral 20.
The belt 20 comprises an axial tensioning means 21,
and a plurality of lateral stiffening mean~ 22 which
are carried by the axial tensioning means 21 and co-
operate therewith to define power transmitting contact
faces 23 on the opposed ends 24 and 25 of the stiffen-
ing means 22, and power ~ransmitting contact faces 26
on the opposed ends 27 and 28 of the axial tensioning
means 21. The belt construction 20 further comprises
fric~ion material 29 which is disposed only on the
end aces 23 of the stiffening means 22 and on the edge
faces 26 of the a~ial tensioning means 21. The fric-
tion material 29 defines only ~he power transmitting
con~act faces of the belt construction, whil~ ~he axial
tensloning means 21 and the stiffening means 22 define
all other e~posed areas of the belt construction 20.
The axial tensioning means 21 is illustrated as
being an annular flat band, and the stiffening means
3~S~
- 10 -
22 are illustra~ed as being cylindrical in configura-
tiOII. However, it is to be understood that the axial
tensioning means 21 can have any desired and suitable
cross-section~l configuration, and the stiffening
means 22 can likewise have any desired and suitable
cross-sectional configuration, as well as varied cross-
sectional conigurations; the important feature is that
the axial ~ensioning means 21 and the lateral stiffen-
ing means 22 define a "backbone structure" for the belt
construction 20.
In addition, the stiffening means 22 can be
formed separate ~rom the a~ial tensioning means 21,
and can be subsequently secured thereto in any desired
manner. Alternatively, the axial tensioning means 21
and the lateral stiffening means 22 can be oxmed to-
gether to provide a homogeneous and one-piece structure.
For e~ample, such one-piece structure can be provided
by an injec~ion molding operation in a manner well
known in the art.
The axial tensionir.g means 21 and the lateral
stiffening means 22 of this invention are ~ormed of
any suitable material that provides an axial and
lateral s~iffness in excess of ~hat normally provided
by polymeric friction materials tha~ normally form the
main body of a belt construction that is reinforced
with such a tensioning means and stiffening means.
In this xegard, it is believed tha~ the means 21 and
~3~
22 can be formed of poly~,eric material, metal, etc.,
or combinations of material, with the material of the
axial tensioning means 21 being the same as or differ-
ent than the material of the lateral stiffening means
22, For example, such combination of materials is
disclosed in the aforementioned U.S. Patents to Warner
et al, No. 4,078,443 and No. 4,108,012, whereby ~hese
two patents are being incorporated into this disclosure
by this reference thereto, not only for a description
of suitable materials, but also for the description of
forming belt cons~ruction by injection molding, etc.,
whereby the details of in~ection molding, etc., for
forming the belt constructions of this invention need
not be further discussed in this application.
The bel~ construction 2d oE this invention is a
V-belt construction as illustrated in FIG. 3. The end
faces 23 of the lateral stiffening means 22, and the
end faces 26 of the axial tensioning means 21, are
shaped in such a way as to deine the substantially
trapezoidal cross-sectional configuration illustrated
in FIG. 3. The ~riction material 29 defines the power
transmitting angled contact faces of the V-belt con-
struction of FIG. 3. Because the axial tensioning
means 21 and the lateral stiffening means 22 extend
to the angled sides 29l illustrated in FIG. 3, it is
believed that ~he belt construction 20 could be
utilized for continuously variable transmission
L3'7~
- 12 -
purposes.
While the friction material 29 can comprise any
sui~able friction mater-al, such as rubber, fabric,
brake facing material, clutch facing material, etc.,
and combinations of such material, it is believed
according to the teachings of this inventlon that
becawse such Eriction material 29 i8 provided only a~
the contact faces of the belt construction 20 of this
invention, hysteretîc heat build up due to ~he repeat-
ed flexing of ~he frictional material 29 during theuse of the power transmission belt construction 20 is
substantially mini~iæed as compared to the heat build
up rate of conventional polymeric belt constructions
under the same operating conditions.
Thus, it is believed that providing the riction
material 29 to form the main body part of the belt
construct:ion 20, as in the aforementioned U.S~
Patents to Warner et al, would result in the friction
material 29 providing too great of a heat build up due
to the continuous flexing o such friction materla~ 29
as in ~he patents to Warner et al, whereby it is be-
lieved that the patents ~o Warner e~ al did not appre-
ciate the fact that ~e amount of friction material 29
can be held to an absolute minimum by disposing the
same only at the power transmitting contact faces of
the "backbone s~ructure' of a composite belt construc-
tion, so that the "backbone structure" itself fonms the
~2~3~6
- 13 ~
main body of the belt construction as provided by
this i~vention.
If desired, a reinforcing cord or cords 30 can
be helically wound during the injection molding of the
axial tensioning means 21 to be completely encapsu-
lated therein. The cord 30 i~ of any suitable materi-
al, such as a material normally forming the cords of
power transmission belts or the like. E'or example,
the cord or cords 30 can be provided in the same man-
ner as set orth in the aforementioned U.S. Patentto Warner et al, No. 4,078,443 at the same time that
the axial ~ensioni~lg means 21 is being injected mold-
ed, with or without the stiffening means 22 being in-
jectlon molded therewith, as the case may beO
In any event, it can be seen that the axial ten-
sioning means or ba.nd 21 prevents the helically wound
cord or cords 30 from projecting ou~ of the side edges
26 thereof as in conventional belt constructions which
have edge cords coming out of the side~ of such cover-
less belt constructions.
However, it is to be understood that it is be-
lieved that the material of the axial tensioning means
21 it~elf could provide the sole a~ial strength for
the belt construction 20 with or without the encapsu-
lated cord or cords 30, and could also encapsulate re-
inforcing fibers or other structure, as dasired.
As previously stated, while the lateral stiff-
3L2~3'7~i~
ening means 22 can have any cross sectional configura-
tion, it can be seen in FIGS. 1 and 2 that the lateral
stiffening means 22 respectively extend from the out-
side surface 31 o~ the axial tensioning means 21, as
well as from the inside surface 32 thereof. The
lateraL sti~fening means 22 tha~ ex~end from ~he out-
side surface 31 o the axial tensioning means 21 are
in radial alignment with the lateral stiffening means
22 that extend from the inside surface 32 thereof.
However, it i~ to be understood that the lateral stif-
ening means 22 could e~tend from the axial tensioning
means 21 in offset relation relative tQ the outside
and inside surfaces 31 and 32 thereof, as provided by
the belt construction 20A illustra~ed in FIG. 4, or
could extend from only one side 31 or 32 of the axial
tensioning means 21, as provided by the belt construc-
tion 20B of FIGS. 5 and 6. In addition, while the
axial stiffeners 2? are illustrated as extending sub-
stantially to the side faces 26 of the axial tensioning
means 21 for the belt construction 20, it is tc be
understood that the axial stifness 22 could extend
beyond the side aces 26 in the manner provided by the
belt cons~ruction 20C of FIG. 7.
Accordingly, the par-ts of the belt constructions
20A, 20B, and 20C that are similar to like parts of
the belt construction 20 are indicated in the drawing
by the same reference numerals, followed by the
3~5~
- lS -
respective referQnce letter "A", "B", or "C".
In particular, the belt construction ~OA of FIG.
: 4 is substantially the same as the belt construction 20
of FIGS. 1-3, except ~hat the lateral stiffening means
22A ~hat ex~end outwardly from the side 31A of the
belt construction 20A are disposed ln offse~ radial
relation to the axial sti~f~nlng means 22A that extend
inwardly from the inside surface 32A of ~he axial ten-
sioning means 21A as illustrated.
].0 While the inside stiffening means 22A of the
belt construction 20A are disposed medially between
a pair of outside axial stiffeners 22A, it is to be
understood that the inside stiffeners 22A could be
arranged iII any desired pattern relative to the pat-
tern of ~he outside stiffeners 22A, as desired.
In any event, the end faces 23A of the stiff
eners 22A, and the end faces 26A o the axial ten-
sioning means 21A, are provided with fric~ional
mat~rial 29A, so that the frictional mater~al 29~ is
disposed only on the power transmitting contact faces
of the belt construction 20A for the reasons previous-
ly se~ forth in connection with the belt construction
20.
The belt construction 20B o this invention
illustra~ed in FIGS. 5 and 6 has the lateral stiffen-
ers 22B extending only from the inside surface 32B of
the axial tensioning means 21B. Each stiffener 22B
23L37S~;
- 16 -
has a cross-sectional configuration tha'c is sub-
stantially trapezoidal to define a tooth having power
transmitting contact faces 33 against which the fric-
tional material 29B is secured, so that the friction
5 ma~erial 29B is disposed only on ~he selected areas
33 of the belt construction 20B to only define the
contact faees 33B thereof, whereby ~he remainder of
the exposed areas of the bel~ construction 20B is
provi~ed by the exposed surfaces of the axial ten-
sioning means 21B and the stiffening means 22B~ Thus,it can be seen that ~he bely cons~ruc~ion 20B com-
prises a toothed belt which transmits its driving
force by having its teeth 22B engaging with suitable
gear ~eeth-like structure in a manner well known in
the art.
Thercfore, it can be seen that by making the
major portion o~ the teeth 22B out of stronger materi-
al than the fri.ction material 29B, and by making the
teeth 22B integral with the band 21B in the manner
previously described, it is believed that shearing of
the teeth 22B is less l~kely than when the teeth of a
belt construction are formed substantially entirely
of friction material.
In regards to the belt construction 20C illus-
trated in FIG. 7, it can be seen that the lateralsti~feners 22C thereof have ~he opposed ends 24C and
25C thereo~ extending beyond the side faces 26C of the
2~ 75
~ 17 -
axial tensioning means 21C, so that the side faces 26C
of the axial tensioning means 21C do not form any part
of the power transmitting contact faces thereof,
whereby the friction material 29C is only disposed on
5 the end faces 23C of the stiffening ~leans 22C.
Therefore, it can be seen that each of thP
previously described and illustrated belt construc-
tions 20, 20A, 20BI and 20C of this inventioll has
power transmitting contact faces, and comprises an
axial tensioning means, a plurality of lateral stiff-
ening means carried by the tensioning means, and fric-
tion material carried by such means; th~ tensioning
means and the stiff.ening means are formed of material
that provides an axial and lateral stiffness in excess
of tha~ normally provided by polymeric fric~ion materi-
al that normally forms ~he main body of a bel~ con-
struction that is reinforced with such a tensioning
means and stiffeni.ng means. The friction material is
only provided on selected areas of such means, so that
all o~ the friction material is located only at the
contact faces of the belt construction, and thereby
defines only ~he contact faces of the belt construc-
tion, while such means define all other exposed areas
of the belt cons~ruction.
Referring now to FIGS. 8, 9, lOA, and lOB, an-
other improved endless power transmission belt con-
struction of this invention is generally indicated by
375i
- 18 -
the reference numeral 120. The belt 120 comprises an
axial tensioning means 121, and a plurality of lateral
stiffening means 122 which are carried by the axial
tensioning means 121 and cooperate therewith to define
S power transmitting contact faces 123 on the opposed
~nds 124 and 125 of the stiffening means 122, and pow-
er transmitting contact faces 126 on the opposed ends
127 and 128 of the axial tensioning means 121. The
belt construction 120 urther comprises friction mate-
rial 129 which is disposed in a relatively thin layeron the means 121 and 122 to fully encapsulate the same.
The friction material 129 has a firs~ portion thereof
disposed on ~he end faces 12~ of the stiffening means
122 and on the edge faces 126 of the axial tensioning
means 121 to define the power transmitting contact
faces of the belt construction; the remainin8 portion
of ~he friction material 129 at least assists in se-
curing the friction material 129 to the means 121 and
122. The axial tensioning means 121 and the stiffen
ing means 122 define substantially a large amount of
the material of the bel~ construc~ion 120, and the
friction material 129 defines a relatively small
amount of the material cf the belt construction 120.
Again, as with the previously described em-
bodiments, the axial tensioning means 121 is illus-
trated as being an annular flat band/ and the stiffen-
ing means 122 are illustrated as being cylindrical in
3~6
- 19 -
configuration. However, it is to be understood that
the configuxations of these means are in no way re-
stric~ed to ~hose illustrated, and that they can have
any desired and ~uitable cross-sectional configuration.
Furthermore, the previous discussion concerning
the formation of, and the material for, the stiffening
means 22 and the tensioning means 21, also applies to
the formation of, and the material for, the stiffening
means 122 and ~he tensioning mea~s 121.
In a manner similar to the belt construction 20,
the belt construction 1?0 is a V-belt construction as
illustrated in FIGS. lOA and lOB.
Again simîlar to the discussion in connection
with the previous embodiments, it ls believed accord-
ing to the teachings of this invention that because
such friction material 129 is provided only in a
relatively thin layer ~hat is no thicker on the non-
contact facP portions of the means 121 and 122 than
is the relatively small thickness of the portion
thereof at the contact ~aces of the belt construction
120 of this invention, hys~eretic heat build up due to
the repeated flexing of the Erictional material 129
during the use of the power transmission belt con-
struction 120 is substantially minimized as compared
to the heat build up rate of conventional polymeric
belt construction~ under the same operating conditions.
Again, it is believed ~hat the pa~ to Warner
~LZ~37~6
- 20 -
et al did not appxeciate the fact that the amoun~ of
friction material 129 can be held to an absolute mini-
mum by disposing the same only in a relatively thin
layer on the "backbone structure" of a composite belt
construction, so that the "baekbone structure" itself
forms the main body of the belt construction as pro-
vided by this in~ention.
It is to be understood ~hat the frietion materi-
al 129 can be disposed on the "backbone ~tructure" 121,
122 in any suitable manner, such as by injection mold-
ing the material 129 onto ~he preformed "backbone
structure" 121, 122, by merely dipping the preformed
"backbone structure" in molten friction material, etc.
If desired, a rein~orcing cord or cords 130 ean
be provided in a manner similar to ~hat previously dis-
cusse~.
As previously stated, while the lateral stiffen-
ing means 122 can have any cross-seetional configura-
tion~ it can be seen in FIGS. 8 and 9 that ~he later-
al stiffening means 122 respec~ively e~tend from theoutside surface 131 o~ the axial tensioning means 121,
as well as from the inside surface 132 thereof. The
lateral stiffening means 122 that extend ~rom the out-
side surface 131 of the axial tensioning means 121 are
25 in radial ~lignment with the lateral stiffening means
122 that extend from the lnside sur~ace 132 thereofO
However, it is to be understood that the lateral
~,2~
- 21 -
stiffening means 122 could extend from the axial ~en-
sioning means 121 in offset relation relative to the
outside and inside surfaces 131 and 132 th~reo, as
provided by the belt constructi.on 120A illustrated in
FIG. ll, or could extend from only one side 131 or 132
of the axial tensioning means 121, as provided by the
belt construction 120B of FIGS. 12 and 13. In addi-
tion, while the friction material 129 has been describ-
ed and illus~rated as completely encapsulating the
"backbone structure" 121, 122, it is to be under-
stood ~hat the friction material can merely encapsu-
late part of the "backbone structure" 121, 122, such
as only encapsulating all or part of just the stiffen-
ing means 122 in the manner provided by the belt con-
struc~ion 120C of FIG. 14.
Accordlngly, the ~arts of the belt construction120A, 120B, and 120C tha~ are similar to like parts of
the belt construction 120 are indicated in the drawing
by the same reference numerals, followed by the re-
spective reference letter "A", "B", or "C".
In particular, the belt construction 120A ofFIG. ll is subs~antially the same as the bel.t con-
struction 120 of FIGS. ~ and 9, except tha~ the la~er-
al stiffening means 122A that extend outwardly from
the side 131A of the belt construction 120A are dis-
posed in offset radial relation to the axial stiffen-
ing means 122A that extend inwardly from the inside
.3~ 6
- 22 -
surface 132A o~ the axial tensioning means 12LA as
illustrated.
While the inside stiffening means 122A of the
belt construction 120A are disposed medially bet~een
a pair of out~lde axial stiffeners 122A~ it is to be
understood that the inside stiffeners 122A could be
arranged in any desired pattern relative to ~he pat-
tern of the outside stiffeners 122A, as desired.
In any event, the end faces 123A of the stiffen-
ers 122A, and the end faces 126A o the axial tension-
ing means 121A, are provided with frictional material
129A, so tha~ the frictional material 129A is disposed
on the power transmitting contact faces of the belt
cons~ruction 120A for the reasons previously set forth
in connection with the belt construction 120.
The belt construction 120~ of this lnven~ion
illustrated in FIGS. 12, 13A, and 13B has the lateral
stiffeners 1~2B extending only from the inside surface
132B of the axial tensioning means 121B. Each stiff-
ener 122B has a cross sectional configuration that issubstantially ~rapezoidal to define a tooth having
power transmitting contact faces 133 against which the
frictional material 129B is secured. The friction
material 129B also completely encapsulates the "back-
bone structure" 121B, 122B in a thin layer thereof inthe same manner as in the belt constructions 120 and
120A, so that ~he friction material 129B is not only
~2~37~i
- 23 -
disposed on ~he selected areas 133 of the belt con-
struction 120B to define the contact faces 133 thereof,
but also is disposed on the remainder of the "backbone
structure" 121B, 122B to at least assist in securing
the friction ma~erial 129B thereto. Thus, it can be
seen that the belt constructlon 120B comprises a tooth-
ed belt which transmits i~s driving force by having
its teeth 122B engaging with suitable gear teeth-like
structure in a manner well known in the art.
Therefore, it can be seen that by making the
major portion of the teeth 122B ou~ of stronger materi-
al than the friction material 129B, and by making the
teeth 122B integral with the band 121B in the manner
previously described, it is believed that shearing of
the teeth 122B is less likely than when the teeth of
a belt construction ~re formed substantially entirely
of fric~ion material.
In regards to the belt construction 120C illus-
trated in FIG. 14, it can be seen that only the later-
al stiffeners 122~ thereof ha~e the friction material129C encapsulated thereon. If desired, the stiffeners
122C can have opposed ends 124C and 125C (not shown)
thereof extending beyond the side faces 126C of the
axial tensioning means 121C, so that the side faces
126C of the a~ial tensioning means 121C do not form
any par~ of the power transmit~ing contact faces there-
of~ whereby the friction material 129C is only disposed
3'`~
- 24 -
on the end faces lZ3C of the stiffening means 122C
at the side edges of the belt construction 120C.
Therefore, it can be seen that each of the pre-
viously described and illustrated belt constructions
120, 120A, 120B, and 120C of this invention has power
transmit~ing contact faces, and comprises an axial ten-
sioning means, a plurality of lateral stiffening means
carried by the tensionin~ means, and friction ma~erial
carried by such means; the tensioning means and the
stiffening means are fo~med of material that provides
an axial and lateral stiffness in excess of that normal-
ly provided by polymeric friction material that normally
forms ~he main body of a belt construction that is re-
inforced with such a tensioning means and stiffening
lS means. The friction material has a first portion
thereof disposed on the means to define the contact
faces thereof, and has a remaining portion thereof dis-
posed on the means to at least assist ln securing the
first portion to the means. The thickness of the first
portion of the friction material is relatively thin,
and the thickness of the remaining portion is no thick-
er than the thickness of the first portlon, whereby a
substantially large amount o~ the belt construction
comprises the material of the means~ and a substantially
small amount of the belt construction comprises the
frlction material,
Accordingly, it can he seen that this invention
not only provides improved endless power transmission
3~7~6
belt constructions, bu~ also this invention provides
methods of making such improved endless power trans-
mission belt cons~ruc~ions.
While the forms and methods o:E this invention
5 now preferred have been illustrated and described as
required, it is to be understood that other forms
and me~hod steps can be utilized and still fall
within the scope of the appended claims.
