A pull strand of high tensile strength which may be composed of a number of parallel, longitudinal steel wires and a series of transverse, stiffener elements made of aluminum or other metal spaced along the pull strand and providing oppositely facing lateral edges for active engagement with coned sheaves are interconnected solely by a continuous molded body of rubber or rubberoid material in adherence with the pull strand and with the transverse elements. The molded body runs longitudinally through identical cavities of the said transverse elements, extending sidewardly at least onto their lateral edges and filling intermediately thereto at least a portion of each space between the sidewalls of the said transverse elements along the said cavities.

FIELD OF THE INVENTION 
This invention relates to power transmission belts of the type intended to 
cooperate with coned sheaves and comprising a strand of material of high 
tensile strength, such as a steel wire strand, combined with transverse 
elements longitudinally spaced along the length of the strand. 
These transverse elements have lateral edges which provide oppositely 
facing surfaces for active engagement with the coned sheaves and act at 
the same time as transverse stiffener members for the belt strand. 
PRIOR ART 
An example of the abovementioned belt type is disclosed in U.S. Pat. No. 
2,638,007 (Reeves). According to this known art, transverse elements are 
frictionally clamped to a continuous molded body of rubber or rubberoid 
material of uniform cross-section by means of a continuous metal clamp 
strip. The ends of the cross section of the strip overhang the lateral 
edges of the strand. Bolts are passed through each of these ends and are 
screwed into each of the transverse elements to clamp the same against the 
said continuous belt body. The assembly formed by the strand, rubber body 
and clamp strip is embedded in and runs longitudinally through identical 
cavities of the transverse elements. 
The means as described for securing the transverse elements to the strands 
gives rise to obvious complications, both in the manufacture and in the 
use of such belts, because of the use of an additional metal clamping 
strip and the bolts necessary to obtain the desired clamping result. 
As a consequence, there is a risk of loosening of screw bolts during long 
continued use of the belt. 
An example of a method for molding an endless belt having oppositely 
inclined facing lateral edges is disclosed in U.S. Pat. No. 4,000,240 
(Green et al). 
SUMMARY OF THE INVENTION 
This invention is directed primarily to an improved belt construction and 
particularly to a simplification and improvement of the means for 
connecting the transverse elements to the belt strand. 
In this respect, it is one object of the invention to shape a belt 
comprising the aforementioned strand and transverse elements but having a 
shape and composition which enables molding it as one integral body by 
which any subsequent mounting of parts is made superfluous. 
It is a further object of the invention to shape and arrange the parts of 
the integral body in a way so as to make sure that the transverse elements 
are engaged by the rubber or rubberoid material of the continuous molded 
body along a sufficient large portion of their surfaces to ensure a safe 
attachment of these elements in the molded body over a very long range of 
use. 
It is still another object of the invention to split up the pull strand 
into two longitudinal sections in one plane each molded by the 
intermediary of one said continuous, flexible body inside one of two 
series of identical inwardly extending opposite sideward slots of the 
transverse elements, thereby providing large engaging surfaces on the 
upper and lower side of each slot. 
Other features of the invention and further objects and advantages thereof 
will become apparent from the following detailed description of a specific 
embodiment thereof, as shown in the drawings.

DETAILED DESCRIPTION 
In the figures the belt as a whole is designated by numeral 1. The belt 
comprises a strand of high tensile strength, composed of two sets of cords 
2, 3 arranged in a common plane. These strands are intended to resist the 
pull forces and each cord may be made of twined steel wire or other 
material of high tensile strength, such as synthetic wire with high 
resistance to stretch. The cords 2, 3 are each embedded in a molded body 
4, 5 of rubber or rubberoid material. This body 4, 5 continues together 
with the strands 2, 3 flexibly along the entire length of the belt. The 
term "rubberoid" includes synthetic material, for example, of a 
polyurethane composition. 
According to the present invention, the material of the bodies 4, 5 adheres 
not only to the surface of the cords 2, 3 but also to the engaging 
surfaces of a series of transverse, identical stiffening members such as 
designated by 6 and 7 which are spaced longitudinally along the entire 
length of the belt 1 preferably at a distance from each other which is 
slightly less than their thickness. 
The member 6, 7 have oppositely facing end surfaces 8, 9 angularly disposed 
relative to a cross-sectional plane of the belt so that the transverse 
members 6, 7 have substantially the overall shape of an isosoeles 
trapezoid. The end surfaces 8, 9 provide for active engagement with coned 
sheaves for the application of the belt 1 as a power transmitter in 
infinitely variable wedge belt drives, while at the same time forming 
transverse stiffening members for the assembly of the belt strand 2, 3 and 
the flexible bodies 4, 5 to absorb the compressive stress which would 
otherwise be placed directly on the assembly by the coned sheaves. 
The transverse members, such as 6, 7, are preferably made of metal and 
aluminum alloy has been found to be suitable and has the advantage that a 
light weight belt is obtained as well as a good adherence between the 
flexible bodies 4, 5 and the metal components of the belt 1. 
In the preferred embodiment, as shown each of the flexible continuous 
bodies 4, 5, is molded inside one of two series of identical, inwardly 
extending, oppositely sideward slots 10, 11 provided in each of the said 
stiffener elements 6, 7. 
In this way, large engaging surfaces between the elastic bodies 4, 5 and 
the upper and lower surfaces of the said slots 10, 11 are shaped. 
Moreover, these engaging surfaces are larger than those as obtained in the 
aforementioned U.S. Pat. No. 2,638,007 (Reeves), because the bodies 4, 5 
extend sidewardly between the transverse elements 6, 7 at least to their 
oppositely facing end surfaces 8, 9. When molding the bodies 4, 5 
integrally with the metal parts 2, 6, 7 in a die, space can be provided 
therein on both sides of the opposite faces 8, 9 of the elements 6, 7 so 
that the mass of the flexible bodies 4, 5 is sidewardly continued outside 
of the surface 8, 9 form friction pads on said surfaces as designated by 
dotted lines 12, 13 in FIG. 1. 
Thus, the friction pads 12, 13 will form one integral unit with the bodies 
4, 5 which has the advantage of increased strength and simple manufacture. 
A good adherence between the material of the rubber or rubberoid type and 
the metal parts engaged therein is obtained, according to the known art 
upon vulcanizing the material in a mold and this is true for synthetic 
material during the phase of its curing. 
It can also be seen in the drawings, that for obtaining a still larger 
engaging surface with the stiffener members 6, 7 and for securing the 
spacing of these members the material of the elastic bodies enters above 
and below the strands 2 and 3 into the spaces such as 14-17, between the 
elements 6, 7 as seen at 18, 20 and 19, 21, adhering to at least a portion 
of the side walls of the elements 6, 7 along and beyond the edges of the 
cavities 10, 11. 
However, as indicated at 21 and 22 in FIGS. 2 and 3, respectively, the 
flexible molded bodies 4 and 5 are respectively indented substantially to 
the surface of the pull strands 2, 3 in the middle plane between the 
adjoining parallel faces of each of two of the stiffener elements 6, 7. 
This indentation is due to the fact that within the mold the strands 2, 3 
are supported in a circular form upon radial extensions of a central 
mandrel extending between the stiffener elements which are positioned in 
the mold. 
In an advantageous embodiment of the invention, as shown in FIGS. 2 and 3, 
and as designated at 24 and 25, the spaces, such as 14-17 between the 
stiffener elements 6, 7 above and below the flexible molded bodies 4, 5 
are filled with a material which is more easily compressible than that of 
the molded material. For this purpose, a spongy material of the 
plastic-foam-type can be used. 
This construction prevents, during use of the belt, the open spaces between 
the elements 6, 7 from becoming filled gradually with dirt or other 
particles whereby the flexibility of the belt would decrease as would the 
coefficient of friction as desired for the power transmission. In both 
cases, this would decrease the efficiency of the transmission. 
In an example of practical application of an endless belt having a diameter 
of 400 mm. in a cylindrical position, the thickness of the stiffener 
elements can be about 3 mm. at a spacing of about 2 mm. 
The stiffener members may be made of a special copper-aluminum alloy having 
high resistance. 
The cavities 4, 5 are preferably positioned in such a way that the plane of 
the strands 2, 3 located at the resulant of the circumferential forces on 
the outer faces 8, 9 of the stiffener elements in order to avoid 
undesirable moments and sideward forces on the belt. Thereby, the amount 
of material in the flexible molded bodies 4, 5 can be reduced to a minimum 
and ensure the connection with the strands 2, 3 and with the stiffener 
elements 6, 7.