An endless power transmission chain-belt (13) is disclosed that is especiy adapted for drivingly connecting the pulleys (2, 3) of a pulley transmission (1). The chain-belt (13) has a chain (10, 12) that is an assembly of a plurality of interleaved sets of links (16, 18, 20, 22). A pivot pin (24) extends through the chains (10, 12) to lace and pivotally interconnect adjacent sets of links (16, 18, 20, 22) to provide an endless chain-belt 13). A plurality of first load block (14, 34, 35) are connected to the chain-belt (13) by at least one projection (15) that engages adjacent pivot pins (24). The first load blocks (14, 34, 35) have a substantially flat first bearing surface (21, 41) that is positioned adjacent the links (16, 18, 20, 22). A plurality of second load blocks (14, 34, 35) are connected to the chain-belt (13) by at least one projection (15). The second load blocks (14, 34, 35 ) have a second bearing surface (21, 41) that is positioned adjacent the links (16, 18, 20, 22) and is disposed at an angle with respect to the first bearing surface (21, 41) of the first load blocks (14, 34, 35).

TECHNICAL FIELD 
This invention relates to metal chain-belts especially adapted to connect 
the pulleys of a pulley transmission, particularly a continuously variable 
transmission (CVT), and broadly comprises a tension member or carrier 
constructed of a plurality of interlaced links arranged in transverse sets 
with the adjacent sets joined by pivot means, and load blocks carried by 
the carrier for engaging the pulleys. 
BACKGROUND ART 
Flexible power transmission means-comprising an assembly of a plurality of 
superimposed steel strips and a plurality of V-shaped blocks of metal are 
known in the art. An example of such construction is disclosed in U.S. 
Pat. No. 3,720,113 granted Mar. 13, 1973 to H. J. Van Doorne et al. In the 
patented structure, the blocks are provided with lateral guides having top 
edges which overlie the steel strips to maintain the parts in assembled 
relationship. The load is carried by the blocks and the blocks can slide 
along the band. 
Another example of a flexible power transmission means is described in U.S. 
Pat. No. 3,949,621 granted Apr. 13, 1976 to Beusink, deceased, et al. in 
which metal plates are mounted on metal strips, the strips being received 
in slots in one of the lateral edges of the plates. 
Other flexible power transmission means comprising an assembly of links, 
pins and pulley contact members are described in U.S. Pat. Nos. 2,038,583, 
granted Apr. 28, 1936 to Maurer and 2,475,264, granted July 5, 1949 to 
Sutton. 
Another metal transmission belt is shown in U.S. Pat. No. 4,645,479. In 
this reference there are a pair of spaced generally parallel chains that 
are each constructed of a plurality of sets of interleaved links. Each set 
is joined to the next adjacent set by a pin and the pin extends across 
both chains. Generally trapezodial load blocks are located between the 
chains and have cut outs in the sides for locating the chains. The load 
blocks are generally contoured at their edges to fit into the V of the 
pulley and are disposed between the chains. The load is carried by the 
chains and its pins. The load blocks are longitudinally positioned with 
respect to the chains by the chain pins. 
DISCLOSURE OF THE INVENTION 
An endless power transmission chain-belt (13) is disclosed that is 
especially adapted for drivingly connecting the pulleys (2, 3) of a pulley 
transmission (1). The chain-belt (13) has a chain (10, 12) that is an 
assembly of a plurality of interleaved sets of links (16, 18, 20, 22). A 
pivot means (24) extends through the chains (10, 12) to lace and pivotally 
interconnect adjacent sets of links (16, 18, 20, 22) to provide an endless 
chain-belt (13). The sets of links (16, 18, 20, 22) of the chain (10, 12) 
are held together by the pivot means (24). A plurality of first load 
blocks (14, 34, 35) are connected to the chain-belt (13). The first load 
blocks (14, 34, 35) have at least one projection (15) that extends in a 
direction towards the chain (10, 12). The projection (15) engages adjacent 
pivot means (24) to secure the first load blocks (14, 34, 35) to the chain 
(10, 12). The first load blocks (14, 34, 35) extend substantially across 
the width of the chain (10, 12) and have a substantially flat first 
bearing surface (21, 41) that is positioned adjacent the links (16, 18, 
20, 22). Each first load block (14, 34, 35) have lateral edges (26, 28) 
shaped to frictionally engage the pulleys (2, 3) of the pulley 
transmission (1). A plurality of second load blocks (14, 34, 35) are 
connected to the chain-belt (13). The second load blocks (14, 34, 35) have 
at least one projection (15) that extends in a direction towards the chain 
(10, 12). The second load blocks (14, 34, 35) have a second bearing 
surface (21, 41) that is positioned adjacent the links (16, 18, 20, 22). 
The second bearing surface (21, 41) is disposed at an angle with respect 
to the first bearing surface (21, 41) of the first load blocks (14, 34, 
35). The second load blocks (14, 34, 35) are disposed at an angle with 
respect to said first load blocks (14, 34, 35) when the first (21, 41) and 
second (21, 41) bearing surface are in contact with the links (16, 18, 20, 
22) and the noise producted by the chain-belt (13) during use is reduced.

BEST MODE FOR CARRYING OUT THE INVENTION 
FIGS. 1 and 2 illustrate schematically a continuously variable transmission 
(CVT) 1 in two drive ratios. The CVT comprises a pair of pulleys 2 and 3 
connected respectively to shafts 4 and 5. One of the shafts being the 
driven shaft and the other shaft being the drive shaft. Pulleys 2 and 3 
comprise a pair of flanges 6 and 7 with at least one of the flanges being 
conical. The pulleys are connected by a belt 8 and the side edges 9 of the 
belt frictionally engage the pulley flanges. At least one flange of each 
pulley is axially moveable with respect to the other so as to vary the 
drive ratios between the pulleys. The arrows indicate the axial movement 
of the flanges to effect different drive ratios. Means beyond the scope of 
this invention can be provided for axially moving a least one flange 
relative to the other. 
The power transmission means of this invention as shown in FIGS. 3-8 
comprises a pair of spaced chains 10, 12 and a plurality of generally 
trapezoidal first load blocks 14 and second load blocks 34 that form an 
endless chain belt 13. Each chain 10 and 12 comprises sets of interleaved 
links 16, 18 and 20, 22, respectively, which are joined by pins 24. The 
first load blocks 14 have tapered sides 26, 28 that are disposed to engage 
the flanges of a pulley. Each first load block 14 is located between the 
next adjacent pins 24. The first load blocks 14 have a projection 15 that 
extends from the first load block into the space 16 between the spaced 
chains 10, 12. The projection 15 engages the pins 24 that join the 
interleaved links together. The projection has grooves 17 positioned on 
opposite sides of the projection. The grooves 17 are disposed for 
receiving the pins 24 and the grooves have a shape that does not restrict 
rotational movement of the first load blocks 14 relative to the pins. The 
center point for the grooves 17 are positioned at substantially the same 
point on opposed surfaces of the projection 15. The grooves allow the 
spaced chains 10, 12 to articulate around the pins 24 during use of the 
chain. The end of the projection 15 that is spaced apart from bottom of 
the first load block terminates in a flange 19 that extends at least 
partially over adjacent pins 24. The positioning of the pins 24 in grooves 
17 of the projection 15 and flange 19 act to secure the first load block 
to the spaced chains 10, 12. The surface of the first load blocks 14 from 
which the projection 15 extends, has a substantially flat first bearing 
surface 21. The first bearing surface 21 is positioned to be in contact 
with one side of the links that form spaced chains 10, 12. The links 16, 
18, 20, 22 have a substantially flat surface 31 against which the first 
bearing surface is positioned. The frst bearing surface 21 of the first 
load blocks 14 is usually disposed to be substantially perpendicular to 
the side 11 of the projection 15. The side 11 of the projection 15 is 
substantially parallel to the outer edge 25 of the spaced chains 10, 12. 
Thus, the first bearing surface 21 is substantially parallel to the edge 
25 of the spaced chains 10, 12. The first bearing surface 21 is also 
substantially perpendicular to a plane 27 that extends through the first 
load block 14 in a direction transverse to the direction of travel of said 
spaced chains 10, 12. The plane 27 extends along the first load blocks 14 
that is spaced apart from the spaced chains 10, 12 can be contoured to 
remove metal from portions of the load block where the metal is not needed 
for strength purposes to reduce the weight of the load block. Thus the 
load blocks 14 are longitudinally positioned by the pins 24, and the load 
is carried by the pins and the chains. The load blocks 14 may be described 
as being generally T-shaped. 
The tapered sides 26, 28 of each load block 14 may be roughened to enhance 
the frictional contact with the flanges 6, 7, respectively of a pulley. In 
actual use, the assembly connects spaced pulleys to provide a drive 
therebetween, the pulleys may be of a variable nature so that the drive 
ratio therebetween is variable, as is known in the art. 
FIGS. 7 and 8 show the second load blocks 34 that are utilized in the 
chain-belt. The second load blocks 34 are constructed substantially the 
same as the first load blocks 14. Items of the second load blocks that are 
the same as the first block block the reference numerals used on the first 
load block will be repeated for those elements. Further, for the sake of 
brevity, we will not redescribe the similar features as these features 
have already been described with respect to the first load blocks 14. 
However, we will describe the differences that are present between the 
second load blocks 34 and the first load blocks 14. The second load blocks 
34 have a second bearing surface 41 that is disposed at an angle with 
respect to the first bearing surface 21 of the first load blocks 14. The 
second bearing surface 41 is also disposed to engage the surface 31 formed 
by the links 16, 18, 20, 22. The second bearing surface 41 on the second 
load blocks 34 is also disposed at an angle A with respect to a line 46 
that extends perpendicularly to a plane 47 that extends through the second 
load block in a direction transverse to the direction of travel for the 
spaced chains 10, 12 where the plane 47 extends along the transverse 
centerline of the second load block 34. The angle A is substantially the 
same as the angle between the first bearing surface 21 and the second 
bearing surface 41. In practice it has been found to be particularly 
desirable to ahve the second bearing surface 41 disposed at an angle from 
about 1.degree. to about 10.degree. with respect to the first bearing 
surface 21. The second load blocks 34 have grooves 37 positioned on 
opposite sides of the projection 15. The grooves 37 are disposed for 
receiving the pins 24 and the grooves have a shape that does not restrict 
rotational movement of the second load blocks 34 relative to the pins. The 
grooves 37 allow the chains 10, 12 to articulate around the pins 24 during 
use of the chain. The center points 38 for the grooves 37 on the second 
load blocks 34 are also disposed at an angle B with respect to a line 236 
that is substantially parallel to line 46. Angle B is substantially the 
same as angle A for the second bearing surface 41. The position for the 
center points 38 for the grooves 37 results in one of the arcuate grooves 
37 being positioned further from the flange 19 that is positioned on the 
top of the projection 15 on the second load block 34. The arcuate groove 
37 are disposed at substantially the same angle as the second baring 
surface 41 on the second load blocks 34. The angle B for the arcuate 
grooves 37 on the second load blocks 34 allow the second bearing surfaces 
41 to be positioned adjacent and in contact with the surface of the links 
16, 18, 20 and 22 of the spaced chains 10, 12. 
The second laod blocks 34 are normally positioned randomly in the 
chain-belt 13 of this invention. The second load blocks are disposed at an 
angle with respect to the first load blocks and engage the flanges 6 and 7 
of the pulleys 2 and 3 in a different manner than the first load blocks 
14. The random positioning of the second load blocks 34 breaks the pattern 
of noise that is produced when the chain-belt 13 engages the flanges of a 
pulley and significantly reduces the noise generated by the chain-belt 13. 
It has been found that random positioning is most effective in reducing 
the noise generated by the chain-belt during use. 
The pulley contacting sides of the first load blocks 14 and second load 
blocks 34 are positioned on opposite sides of the spaced chains 10, 12 and 
this allows the combined chains 10, 12 to be substantially as wide as the 
first and second load blocks. This allows as many links as possible to be 
used to form the spaced chains 10, 12 which improves the tensile strength 
of the chains. The projection 15 is also relatively thin so that not many 
links are lost in the space required for the projection. In practice it 
has been found that approximately 40% more links can be used in the chain 
of the present invention when compared to prior art CVT chains with load 
blocks. 
The solid monolithic load blocks are also very strong and very effective in 
handling the forces encountered in contacting the flanges 6 and 7 of the 
pulley. In operation the first load blocks 14 and the second load blocks 
34 are forced against the spaced chains 10, 12 so that first bearing 
surface 21 and second bearing surface 41 are in contact against the links 
of the chains. This spreads the forces on the chain-belt 13 over the 
bearing surfaces of the first and second load blocks and also over the 
links of the spaced chains 10, 12. This reduces the load that must be 
carried by the projection 15 on the load blocks and the pins 24 that 
secure together the links of the spaced chains 10, 12. This allows the 
projection to be relatively small in size as the basic role of the 
projection is to hold the first and second load blocks in position 
adjacent the spaced chains 10, 12 and to assist in removing the first and 
second load blocks from the pulleys. Accordingly, the spaced chains 10, 12 
can be as large as possible to increase the tensile strength of the 
chains. 
The first load blocks 14 and second load blocks 34 may be constructed of 
steel or other suitable material and the chain links are generally stamped 
from sheet metal ribbon stock and the pins are generally die formed metal 
stock. The opposite ends of the pins can be upset to retain the assembly 
of links, or in a preferred embodiment, the outside links of the chains 
are press-fit on the pins during the assembly of the links and load blocks 
while the inner links are slip-fit on the pins. 
The second load blocks 34 can also be rotated 180.degree. when they are 
positioned on the chain-belt 13. The rotated second load blocks are given 
the reference numeral 35 in FIG. 3. The rotated second load blocks 35 are 
the same as the second load blocks 34 except that the load block has been 
rotated 180.degree. with respect to the chain-belt. This rotation places 
the second bearing surface 41 on the rotated second load blocks 35 at an 
angle with respect to the first load bearing surface 21 of the first load 
blocks 14 and the second load bearing surface 41 of the second load blocks 
34. Although FIG. 3 shows first load blocks 14, second load blocks 34 and 
rotated second load blocks 35 being used on the chain-belt 13 it should be 
understood that only second load blocks 34 and rotated second load blocks 
35 can be utilized. The second load blocks 34 and rotated second load 
blocks 35 are normally randomly positioned in the chain-belt 13 and engage 
the flanges 6 and 7 of the pulleys 2, 3 at different positions to reduce 
the noise generated by the chain-belt during use. 
FIGS. 9-13 show another construction of the present invention that utilizes 
a single chain 61 and a plurality of generally trapezodial first load 
blocks 65 and second load blocks 85 to form an endless chain-belt 67. The 
chain 61 is formed of sets of interleaved links 66, 68 respectively, which 
are pivotally joined together by pins 74. The first load blocks 65 have 
tapered sides 76, 78 that are disposed to engage the flanges of a pulley. 
Each load block is located between adjacent pins 74 on the chain-belt 67. 
The first load blocks 65 have a substantially flat first bearing surface 
71 that is disposed in substantially the same manner and for the same 
purpose as the first bearing surface 21 utilized with the first load 
blocks 14 previously described for chain-belt 14. A projection 75 extends 
from each end of the first load blocks 65 and extends between the adjacent 
pins 74. The projections 75 engage the pins 74 that join the interleaved 
links together. The projections 75 have grooves 77 that are positioned on 
opposite sides of the projections. The grooves 77 are disposed for 
receiving the pins 74 and the grooves have a shape that does not restrict 
rotational movement of the first load blocks 65 relative to the pins. The 
grooves 77 allow the chain 61 to articulate around the pins 74 during use 
of the chain. The ends of the projections 75 that are spaced from the 
bottom of the first load blocks terminate in a flange 79 that extends at 
least partially over the adjacent pins 74. The positioning of the pins 74 
in the grooves 77 of the projections 75 and the flanges 79 act to secure 
the first load blocks 65 to the chain 61. 
The second load blocks 85 are substantially the same as the first load 
blocks 65. However, the second load blocks 85 have a second bearing 
surface 91 and grooves 97 that are disposed in substantially the same 
manner and for the same purpose as the second bearing surface 41 and 
grooves 37 of the second load blocks 34 as previously described for 
chain-belt 14. The second bearing surface 91 and grooves 97 are disposed 
at substantially the same angle with respect to the first bearing surface 
71 as previously described for the second bearing surface 41 and grooves 
37 of the second load blocks 34 of the chain-belt 14. The second load 
blocks 85 are also randomly positioned in the chain-belt 67. Thus, the 
first load blocks 65 and second load blocks 85 are essentially the same in 
structure and function as the previously discussed first load blocks 14 
and second load blocks 34. The only significant difference is that the 
projections 75 for the present load blocks are located on each end of the 
load blocks instead of in the center of the load blocks. 
The second load blocks 85 can be rotated 180.degree. when they are 
positioned on the chain-belt 67. The rotated second load blocks 86 are the 
same as the second load blocks 85 except that the load block has been 
rotated 180.degree. . This rotation is done for the same purpose and in 
the same manner as previously described for second load blocks 34. The 
second load blocks 85 and rotated second load blocks 86 can also be used 
exclusively in the chain-belt 67 as previously described and these load 
blocks would be randomly positioned on the chain-belt 67. 
The chain-belt 67 of this embodiment functions in the same basic manner as 
the previously described chain-belt 13. One advantage of this embodiment 
is that the projections 75 are located on the outside edge of the chain 61 
and the projections can act to retain the links 66, 68 in their position 
in the chain 61. This allows guide links or other devices that are 
normally used to hold the chain together to be eliminated. 
In practice it has been found that the construction utilized for the 
chain-belt of this invention can reduce the noise produced by the 
chain-belt during use from about 40% to about 70% over similar prior art 
chain-belts. 
The above description is given for the sake of explanation. Various 
modifications and substitutions, other than those cited, can be made 
without departing from the scope of the following claims.