Abstract:
In the case of highly mobile vehicles overloading of the travelling pads ( 3 ) of crawler tracks frequently gives rise to incipient cracks in the base plate ( 14 ), which generally start from the bottom of the incision of the tongue. A long service life for the travelling pad ( 3 ) with base plate ( 14 ) is achieved by the base plate ( 14 ) being incision-free in the retaining region ( 10 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a crawler track link member which incorporates structure for the support of traveling pads, studs, snow or mud grippers or buoyancy aids. 
     2. Discussion of the Prior Art 
     German published specification (DE-AS) No 16 05 509 discloses a caterpillar or crawler track link member having a plate-shaped slide-on portion in the form of a travelling pad. A base plate which is connected to the travelling pad has a stamped-out tongue which, when the travelling pad is pushed into the crawler track link member over an abutment projection until—after the travelling pad moves into a condition of abutment—the travelling pad slides forwardly until it drops in a latching relationship on the crawler track link member behind a projection. 
     That fixing principle is also known in relation to travelling pads in accordance with DE 33 35 937 C2 and DE 195 44 458 A1. 
     During travel of the track-laying vehicle, travelling pads of that kind are subjected to stresses due to high contact pressures, thrust loadings and high dynamic shock loadings. Particularly in the case of highly mobile vehicles, overloading frequently causes the base plate to be subjected to incipient cracks or fractures which generally start from the bottom of the incision of the tongue retaining portion. If the incipient cracks or fractures are not noticed sufficiently early or if travelling pads with base plates which have been subjected to incipient cracking or fracturing due to rubber wear are not removed, then the base plate encounters a complete rupture. Travelling pads with completely fractured base plates represent a potential danger since they can fly off the track when the vehicle is travelling. 
     Various endeavours have been undertaken to avoid or reduce the risk of an incipient crack or fracture. For that purpose for example the notch forming factor was introduced by providing a larger radius in the incision region of the tongue, and fixing the stamping direction in the cutting operation to avoid stress peaks on the flexural tensile side. An increase in the thickness of the initial sheet metal was also tried; however, it was not possible for those measure to provide a definitive solution to the cracking problem. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is intended to design the slide-on portion so as to prevent the occurrence of incipient cracks and ruptures on base plates of slide-on portions for crawler tracks. 
     The manner in which that object is attained provides for the securing tongue of the base plate to be no longer cut out therefrom and pushed out, but rather the base plate is provided with an impressed or stamped out portion in the region of the shaping or deformation which was earlier pushed out therefrom, and which implements the function of the deforming latching portion. 
     The base plate is now no longer weakened by the incisions. There is no longer any notch forming factor which had considerably increased the stress on the component. There is no need for an increase in the thickness of the base plate, which signifies that the weight of the sheet metal component is also not increased. The slide-on portion can be fitted and removed in a simple manner by existing on-board tools. 
     Tests which have been carried out have shown that no incipient cracks and ruptures were encountered by the base plates, over the useful life of the slide-on portion. The elimination of the incisions in the base plate also affords a reduction in manufacturing costs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention are illustrated in the drawing in which: 
     FIGS. 1 and 2 are views in cross-section of travelling pads in a crawler track link member, 
     FIG. 3 is a perspective view of a travelling pad in a crawler track link member, 
     FIG. 4 is a view in section taken along line IV—IV in FIG. 3, 
     FIG. 5 is a view in cross-section of a further travelling pad in a crawler track link member, 
     FIG. 6 is a view in section taken along line VI—VI in FIG. 5, 
     FIG. 7 shows a base plate of the travelling pad illustrated in FIG. 5, 
     FIG. 8 shows a portion of a crawler track with a travelling pad, 
     FIG. 9 shows a sectional view of part of a travelling pad as shown in FIG. 8, 
     FIG. 10 shows a base plate of the travelling pad shown in FIGS. 8 and 9, and 
     FIG. 11 is a view in cross-section taken along line XI—XI in FIG.  10 . 
    
    
     Referring to FIG. 1, pushed into guide grooves  1  (which are not further shown) in a tubular body  2  is a travelling pad  3  with a base plate  4 . 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The base plate  4  is disposed in a retained or latched condition between two abutments  5 ,  6 , referring to the latching region  10 . When the travelling pad  3  with the base plate  4  is pushed into the guide grooves  1  the base plate  4  slides over the abutment  6 . Upon that occurrence, the base plate  4  is elastically deformed. When the travelling pad  3  is worn the base plate  4  is adapted to be lifted over the abutment  6  through an opening indicated by a phantom line at  7 , by means of a tool represented by line  11  (not shown), and is to be levered out by way of a further tool (also not shown) which is to be inserted as indicated by the arrow  8 . The base plate  4  is disposed in a main plane  9 , and is free of any incisions, in essence it is in the form of a tongueless base plate  4 . 
     Referring to FIG. 2, in a departure from FIG. 1 a base plate  14  is provided with a deformation or shaping  15  formed by non-cutting shaping. The main plane  9  and the tongue plane  16  form an angle  17 . That results in frictional contact when the travelling pad  13  is pushed in or out of the tubular body  2 , only between the deformation  15  and the abutment  6 . The shaping zones in the latching region  10  which result in the formation of the tongue  15  are described with reference to FIG.  7 . 
     Referring to FIGS. 3 and 4, in the case of a travelling pad  23 —similarly to FIGS.  2  and  7 —a base plate  24  with a tongue  25  which is formed therefrom by non-cutting shaping or deformation is provided in the latching region  10 . The base plate  24  extends in terms of surface area with the major part thereof over the travelling pad  23 . An elastomer layer  26  is disposed between a wearable steel body  27  which engages into the guide grooves  1  in a tubular body  22 , which is shown in dash-dotted line. Similarly to the abutments  5 ,  6  shown in FIGS. 1 and 2, the base plate  24  is also disposed between abutments  28  and  29 . An opening for lifting the tongue  25  out of the tubular body  22  is identified by reference numeral  30 . 
     As shown in FIGS. 5 to  7 , a travelling pad  33  which is fixed in a tubular body  32  has a base plate  34  corresponding to that of FIGS. 2 and 4. The base plate  34  has two shaped or deformation zones  36  in the retaining region  10 . Those shaped zones  36  provide for the formation of a deformation  35  corresponding to the angle  17  with respect to the main plane  9 , as shown in FIG.  2 . The base plate  34 , which extends between abutments  38  and  39 , is the carrier of the travelling pad  33  and at the same time it serves to form a positively locking connection with the tubular body  32  by engagement into the guide grooves  31  of the tubular body  32 . An opening  40  serves for disengagement of the deformation  35  at the abutment  39 . 
     In the case of a crawler track  50  as shown in FIG. 8, tubular bodies  51  with guide teeth  52  are hingedly connected together by means of rubber-mounted pins  53  which are arranged in the tubular bodies  51 , and connectors  54  which are fixed on the pins  53 . 
     Each tubular body  51  has guide grooves  55  and abutments  56 ,  57  for fixing a travelling pad  63 . The abutment at the insertion side is denoted by reference numeral  56  and the abutment at the rear side is denoted by reference numeral  57 . 
     As shown in FIG. 9, an intermediate plate  64  with guide bars  65  for the guide grooves  55  and a base plate  74  with a deformations or shaped portion  75  are joined to the travelling pad  63  through vulcanizing. The deformation or shaped portion  75  has rubber disposed therebeneath in the latching region  10 . 
     As shown in FIG. 8, the tongue  75  of the base plate  74  has a double corrugated shape. That is afforded by the three shaped zones  76  and  77  as shown in FIG.  10 . 
     In addition the base plate  74  has an end abutment  78  which corresponds with a rear wall  79  with the abutment  57  of the tubular body  51 . 
     The abutment  56  of the tubular body  51  is provided with a central recess  80  which corresponds to an oppositely disposed recess  81  in of the travelling pad  63 . 
     Finally, the base plate  74  has stiffening beads or corrugations  81  which are disposed in the direction of travel  80  of the crawler track  50 , as shown in FIG.  10 .