Abstract:
A plate-link chain composed of a plurality of plates that form plate sets, which are connected to an adjacent plate set with a hinge joint. At least some of the plates have a stopping means that limits bending of the plate-link chain in a direction opposite to the bend direction the chain undergoes when it passes over and around a pulley or a gear with which the chain comes into contacting engagement when the pulley or gear rotates.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a plate-link chain composed of a plurality of plates that form plate sets, which are connected to adjacent plate sets with a hinge joint. 
     2. Description of the Related Art 
     Plate-link chains are used in transmissions, for example those having continuously variable transmission ratio properties (a continuously variable transmission or CVT). The chain is positioned between pulleys in the form of pairs of conical disks having a variable spacing between the disks of a disk pair, or as a toothed plate-link chain in combination with gears. Chain strand vibrations arise through the effects of forces acting on the chain links as the chain runs onto or off of a sprocket in the toothed plate-link chain transmission, or onto or off a pulley in a CVT transmission. Strand vibrations here mean transverse vibrations of the chain between the pulleys or sprockets. The impacts of the tooth flanks in a toothed plate-link chain in combination with the polygon effect of the link chain excites the chain strand to vibration. A similar thing happens with plate-link chains in CVT transmissions between the rocker member faces and the pulleys. As a result of the entry impulses as the toothed plates enter as a toothed plate-link chain meshes with the gear, vibrations can occur which can reach various frequencies, depending upon the speed of the chain. Such vibrations can have a negative effect on the acoustic behavior of such a chain drive. To prevent those unwanted effects on the acoustic behavior of the transmission, it is possible to install within the transmission additional remedial measures, such as, for example, sliding rails or damping elements. Such measures require additional construction space, however, and also increase the production costs. 
     Reducing chain strand vibrations by applying measures to the chains is known. For example, U.S. Pat. No. 1,780,040 describes a toothed plate with a right-angle bend on the back. That arrangement blocks the vibration of the chain in one direction. The plate can also be designed as a guide plate. A disadvantage of that solution is the very stiff implementation of the plates, especially in the back region, which results in an increase in the plate rigidity and as a consequence an increase in the tensile stresses at the openings in the plate that receive the hinge pins. An additional disadvantage is the increased construction space required by the chain because of the offset bend, and expensive production costs for the individual plates. 
     One object of the present invention is to provide plate-link chains that are simple and inexpensive to produce, and that also reduce chain strand vibrations. Another object is to provide a plate-link chain that allows additional damping measures such as sliding rails or damping elements to be dispensed with, so that the requisite construction space and the costs of producing a transmission can be reduced. 
     SUMMARY OF THE INVENTION 
     The object is achieved by a plate-link chain made of a plurality of plates that form plate sets that are connected to an adjacent plate set with a hinge joint, and wherein at least part of the plates have a stopping means that limits the bending of the plate-link chain around the hinge joint in one bending direction. Preferably, the bending of the plate-link chain in the direction opposite to the bending when encircling a sprocket or pulley is limited, so that the bending necessary for encircling is not limited. The plate-link chain can also be a toothed plate-link chain. 
     The stopping means can be a bend that abuts against the edge of an adjacent plate when the plate-link chain bends. Preferably there is provision for the plates provided with a stopping means to have an opening between the hinge joints. 
     Alternatively, the stopping means can include at least one lug that engages an opening of a guide plate. Another embodiment includes the provision that the stopping means is a side flank of the plate. Another embodiment includes the provision that the hinge joint includes a pin and the stopping means includes a wing that abuts against a pin of an adjacent hinge joint when the plate-link chain bends. Another embodiment includes the provision that the stopping means is a bent wing of a plate that abuts against a pin of an adjacent hinge joint when the plate-link chain bends. 
     Preferably, there is a provision that in each case one rocker member of a hinge joint is connected to the plates of a plate set through an attachment opening, and two rocker members of adjacent plate sets form the hinge joint, where the rocker members can roll or slide on each other with a roller profile. Preferably there is a provision that plate sets include at least one guide plate. The guide plate can be located inside the plate set, but it can also be positioned at the outer ends of the plate set. 
     The object identified at the outset is also achieved by a plate with a feature for a plate-link chain of the chain in accordance with the invention, and a transmission having a plate-link chain in accordance with the invention. The transmission can be a gear transmission or a transmission with variable transmission ratio, in particular a CVT transmission. Correspondingly, the plate-link chain can also be a toothed plate-link chain. A toothed plate-link chain usually has guide plates. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure, operation, and advantages of the present invention will become further apparent upon consideration of the following description, taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective view of a first embodiment of a guide plate in accordance with the invention; 
         FIG. 2  is a perspective view of a portion of a toothed plate-link chain with a guide plate in accordance with  FIG. 1 ; 
         FIG. 3  is a side view of a toothed plate-link chain in accordance with  FIG. 2 ; 
         FIG. 4  is an enlarged detail of a portion of  FIG. 3 ; 
         FIG. 5  is a first exemplary embodiment of a toothed plate in accordance with the invention; 
         FIG. 6  is a perspective view of a portion of a toothed plate-link chain including a toothed plate in accordance with  FIG. 5 ; 
         FIG. 7  is a toothed plate-link chain with a toothed plate in accordance with  FIG. 5  in a first bent position; 
         FIG. 8  is a side-view of a toothed plate-link chain in accordance with  FIG. 7  in a second bent position; 
         FIG. 9  is a second exemplary embodiment of a toothed plate in accordance with the invention; 
         FIG. 10  is a perspective view of a portion of a toothed plate-link chain including toothed plates in accordance with  FIG. 9 ; 
         FIG. 11  is a side view of a portion of a toothed plate-link chain in accordance with  FIG. 10  in an extended position; 
         FIG. 12  is the chain of  FIG. 11  in a bent position of the toothed plate-link chain; 
         FIG. 13  is a side view of a third exemplary embodiment of a toothed plate in accordance with the invention; 
         FIG. 14  is a perspective view of a portion of a toothed plate-link chain including toothed plates in accordance with  FIG. 13 ; 
         FIG. 15  is a side view of the toothed plate-link chain of  FIG. 14  in a bent condition; 
         FIG. 16  is an enlarged detail of a portion of  FIG. 15 ; 
         FIG. 17  is perspective rear view of a fourth exemplary embodiment of a toothed plate in accordance with the invention; 
         FIG. 18  is a perspective front view of the toothed plate shown in  FIG. 17 ; 
         FIG. 19  is a perspective view of a toothed plate-link chain including toothed plates in accordance with  FIGS. 17 and 18 ; 
         FIG. 20  is a side view detail of toothed plate-link chain of  FIG. 19  in a bent position; 
         FIG. 21  is a side view of a known toothed plate-link chain; and 
         FIG. 22  is a top view of the toothed plate-link chain of  FIG. 21 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 21  shows a side view and  FIG. 22  a top view of a plate link chain  1  in accordance with the state of the art, with a two-plate connection. The basic construction of plate-link chains and toothed plate-link chains and the terms used in describing the exemplary embodiments in accordance with the invention will be explained on the basis of the structures shown in  FIGS. 21 and 22 . The exemplary embodiments will be described using the example of a plate-link chain having a two-plate connection, but they are equally applicable to a plate-link chain having a three-plate connection. 
     Plate link chain  1  includes a large number of plates  2  and opposed plates  2 ′. Plates  2  and opposed plates  2 ′ are arranged alternately, in a transverse direction of chain  1 , and are combined into a hinge joint with hinge joint pins  4 . Consequently both ends of a plate  2  are connected to one or two opposed plates  2 ′ by means of a hinge joint, and, correspondingly, both ends of an opposed plate  2 ′ are connected to one or two plates  2  by a hinge joint. 
     The hinge joint pins  4  can be in one piece, but are preferably in two pieces, with a rocker member  5  being associated with each of the plates  2  and rolling on a rocker member  5 ′ associated with the opposed plate  2 . In addition, rocker members  5 ,  5 ′ each have a roller profile  7  and  7 ′ respectively, with which they can roll on or slide against each other. The roller profiles  7 ,  7 ′ can be identical or different. 
     The plates  2  and opposed plates  2 ′ are stacked transversely to the chain running direction L (that is identified by an arrow with the reference label L), so that an overlapping opposed plate  2 ′ is positioned between two hinge joint pins  4  that are arranged side-by-side and perpendicular to the running direction L. Similarly, a plate  2  is positioned between and overlaps two opposed plates  2 ′ that are side by side transversely, relative to the running direction. Of course, that does not apply to the plates  2  or opposed plates  2 ′ that are located on the outside, transversely to the running direction  2 , which have a neighboring plate on only one side. 
     The sets of plates  2  formed as described above (also referred to as plate stacks) form a chain link  8  by sets. Correspondingly, the sets of opposed plates  2 ′ form a chain link  8 ′ by sets. In the illustrated example the plates  2  and opposed plates  2 ′ can be identically formed parts, a differentiation between plates  2  and opposed plates  2 ′ being recognizable only by the arrangement in the chain. The following description will therefore only refer to plates  2 , because they are identical to the opposed plates  2 ′ except for the arrangement in sets.  FIG. 22  shows a plate set of three plates  2  and two opposed plates  2 ′; but it is also possible to provide plate sets with any other number of plates  2  and opposed plates  2 ′. 
     In the case of a toothed plate-link chain, the plates  2  are each provided with plate teeth  9 , as can be seen in  FIG. 21 . In the case of a plate-link chain for use in a CVT transmission, for example, the plate teeth  9  are not present. With the plate teeth  9 , plate link chain  1  can mesh with a toothed part, for example a gear. The spacing between plates  2  and opposed plates  2 ′ is such that when the chain is extended a uniform spacing results overall between plate teeth  9 . The opposed plates  2 ′ are also provided with plate teeth  9 , so that all of the plates and opposed plates are provided with plate teeth  9 . But it is likewise also possible to provide either only plates  2  or opposed plates  2 ′ with two plate teeth  9 , or to provide plates  2  and opposed plates  2 ′ each with only one plate tooth  9 . The plate sets are closed on both sides by guide plates  10 . 
       FIG. 1  shows an embodiment of a guide plate  10  in accordance with the invention with receiving openings  11  for receiving rocker members  5 ,  5 ′. The guide plates  10  include a main body  15  having upstanding legs  12 , on each of the outer ends of which there is provided a bent end  13 . Between the receiving openings  11  an opening  14  is formed in main body  15 , which also includes a downwardly-extending lobe  16  facing away from legs  12 . 
       FIG. 2  shows guide plate  10  in accordance with the invention installed in a plate link chain  1 . Guide plate  10  is part of a plate set  8  or  8 ′, as was described relative to  FIGS. 21 and 22 , and is firmly connected to the associated rocker members  5 ,  5 ′.  FIG. 3  shows a portion of toothed plate-link chain  1  in a side view and in a bowed or bent position, in which the bend is away from the teeth . As shown in  FIG. 4 , the undersides of bent ends  13  are resting on the plate top  17  of an adjacent plate  2 . 
       FIG. 5  shows a first exemplary embodiment of a toothed plate  2 . 1  in accordance with the invention. The main body  15  of toothed plate  2 . 1  includes receiving openings  11  for pairs of both interacting rocker members  5 ,  5 ′ of two different plate sets. Positioned at each of the ends  18  and  18 ′ are lugs  19  and  19 ′, which extend from the main body  15  laterally in reference to the running direction L of the chain. 
       FIG. 6  shows a detail of a plate-link chain with a toothed plate  2 . 1  in accordance with  FIG. 5 . The series of toothed plates  2 . 1  positioned one after the other in the running direction L of the chain are positioned immediately beside the series of guide plates  10 . Lugs  19  and  19 ′ each engage an opening comparable to the opening  14  in guide plates  10  shown in  FIG. 1 . 
       FIG. 7  shows a bent position of a portion of toothed plate-link chain  1  in accordance with  FIG. 6 , with toothed plate-link chain  1  bent in the direction of the teeth. In that position the lugs  19  do not contact guide plate  10 .  FIG. 8  shows a position of the toothed plate link chain in accordance with  FIG. 7  bent in the opposite direction, hence in the direction of the plate top  17 . In that position the lugs  19  contact opening  14  of the guide plates and thus prevent further bending. 
       FIG. 9  shows a second exemplary embodiment of a toothed plate  2 . 2  in accordance with the invention. Toothed plate  2 . 2  will be described only in terms of the differences from the embodiment shown in  FIG. 5 . Instead of a lug  19  or  19 ′, toothed plate  2 . 2  has end flanks  20  and  20 ′.  FIG. 10  shows a portion of a plate-link chain  1  with toothed plates  2 . 2  in accordance with  FIG. 9 . The manner of operation of the end flanks is illustrated in  FIGS. 11 and 12 .  FIG. 11  shows the straight position of the chain, while  FIG. 12  shows the chain in a bent position with bending in the direction of the plate tops  17 . In the position in accordance with  FIG. 12 , the end flanks  20  and  20 ′ of adjacent toothed plates contact each other and thus prevent further bending of plate-link chain  1 . 
       FIG. 13  shows a third embodiment of a toothed plate  2 . 3  in accordance with the invention. Wings  21  and  21 ′ extending in the running direction L of the chain are provided as a bend stopping means. Wings  21  and  21 ′ abut against adjacent pins  4  or rocker members  5 ,  5 ′ when plate-link chain  1  bends.  FIG. 14  shows a portion of a plate-link chain  1  with toothed plates  2 . 3  in accordance with the invention. Toothed plates  2 . 3  are positioned within the group of plates in such a way that in the longitudinal series of plates in which the toothed plates  2 . 3  are positioned, a pin  4  or a combination of rocker members  5  and  5 ′ (which can be referred to collectively as pin  4  in accordance with  FIG. 1 ) that extend through other adjacent plates do not pas through toothed plates  2 . 3 . Wings  21  and  21 ′ can abut rocker members  5 ,  5 ′ when toothed plate-link chain  1  bends in accordance with the illustration in  FIG. 15 .  FIG. 16  shows how the wings  21  and  21 ′ of adjacent toothed plates  2 . 3  abut against adjacent rocker members  5 ,  5 ′ when toothed plate-link chain  1  bends. 
       FIGS. 17 and 18  show a fourth exemplary embodiment of a toothed plate  2 . 4  in accordance with the invention. A bent-over wing  22  is positioned at plate top  17  as a stopping means. Bent-over wing  22  extends over only part of the length of plate top  17 , and it has a width at starting end  23  that has a width that corresponds to the width  25  of the main body  15  of toothed plate  2 . 4 . On a contact face  24 , bent-over wing  22  is wider than at starting end  23 , so that its width  26  in the region of contact end  24  is greater than the width  25  of toothed plate  2 . 4 . The region of plate top  17  that is not overlaid by bent-over wing  22  has a stopping surface  27  that can come into contact with the underside of a bent-over wing  22  of an adjacent toothed plate  2 . 4 .at contact end  24 .  FIG. 19  shows a portion of a plate-link chain  1  with toothed plates  2 . 4  in accordance with  FIGS. 17 and 18 . Toothed plates  2 . 4  are all installed in toothed plate-link chain  1  in the same orientation.  FIG. 20  illustrates the manner of operation of the stopping means of the toothed plate embodiment shown in  FIGS. 17 and 18 . If the toothed plate-link chain is bent in the direction of the plate top  17 , the bent-over wings  22  strike the stopping surface  27  of the adjacent toothed plates. 
     Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention. It is therefore intended to encompass within the appended claims all such changes and modifications that fall within the scope of the present invention.