Patent Publication Number: US-10759637-B2

Title: Segmented shape-compliant wear pad for telescoping boom assembly

Description:
RELATED APPLICATION 
     The present patent document claims the benefit of priority to U.S. Provisional Patent Application No. 62/199,167, filed Jul. 30, 2015, and entitled “SEGMENTED SHAPE-COMPLIANT WEAR PAD FOR TELESCOPING BOOM ASSEMBLY,” the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present application relates to construction equipment and machines equipped with telescoping boom assemblies, such as cranes, teleloaders, and the like. In particular, the present application relates to the wear pads—typically replaceable—that are positioned between the nested sections of the telescoping boom assemblies. 
     Wear pads typically support, in part, the weight of a section of a telescoping boom assembly relative to another section of the telescoping boom assembly. Wear pads also typically reduce the sliding friction between the various sections of the telescoping boom assembly. Further, the wear pads typically are designed to be replaceable. In other words, the wear pads are typically a relatively lower cost and more easily replaced feature of the telescoping boom assembly that reduces the wear and consequent replacement of the various sections of the telescoping boom assembly. 
     Presently known wear pads, however, may suffer from several deficiencies. First, telescoping boom assemblies have increased in structural sophistication from simple box/beam construction that require only flat wear pads to boom assemblies in which one or more section may have multiple segments of varying angles and/or radii of curvature. These latter boom designs typically require wear pads that are machined for a specific design of the section and, in some instances, for a specific, in-use section of a telescoping boom assembly. In other words, the proliferation of boom designs requires an equal proliferation of designs for wear pads. Therefore, the wear pads often require specific machining and adjustment of the wear pad at both the manufacturing level and at the field level when installing the wear pads. 
     Consequent to the proliferation of the number of designs of wear pads is the requirement to keep multiple and often uniquely sized and shaped blanks from which the wear pads are manufactured. The use of uniquely sized and shaped blanks typically costs significantly more than using off-the-shelf flats or standard shapes of blanks to manufacture a wear pad. 
     Thus, there is a need for a wear pad that is formed from a common blank or easily obtainable shape of material. There is also a need for a wear pad that reduces the amount of wasted raw material during the manufacturing of the wear pad. Further, there is a need for a wear pad that is easily machined for a variety of unique shapes of the various sections of a telescoping boom assembly, particularly one that is capable of conforming more easily to inconsistent or irregular contours. Finally, there is a need for a construction vehicle, particularly a crane, with a telescoping boom assembly equipped with such wear pads. 
     BRIEF SUMMARY 
     A wear pad for positioning between a first section and a second section of a telescoping boom assembly comprises a material that includes a first surface and a second surface spaced apart a height from the first surface, a length, and at least one groove that extends a depth into at least one of the first surface and the second surface. The depth of the groove is less than the height between the first surface and the second surface. 
     In another embodiment, a wear pad for positioning between a first section and a second section of a telescoping boom assembly comprises a material that includes a first surface and a second surface spaced apart a height from the first surface, a length, and at least one groove that extends a depth into at least one of the first surface and the second surface. The depth of the groove is less than the height between the first surface and the second surface. The wear pad further comprises a first portion that includes the at least one groove and a first bending plane positioned at a first distance between the first surface and the second surface. The wear pad also includes a second portion that includes a second bending plane positioned at a second distance between the first surface and the second surface, wherein the second distance is different than the first distance. 
     In yet another embodiment, a wear pad for positioning between a first section and a second section of a telescoping boom assembly comprises a material that includes a first surface and a second surface spaced apart a height from the first surface, a length, and at least one groove that extends a depth into at least one of the first surface and the second surface. The depth of the groove is less than the height between the first surface and the second surface. The wear pad further comprises a first portion that includes the at least one groove, the first portion having a first bending stiffness. The wear pad also includes a second portion having a second bending stiffness, wherein the second bending stiffness is different than the first bending stiffness. 
     In yet another embodiment, a wear pad for positioning between a first section and a second section of a telescoping boom assembly comprises a material that includes a first surface and a second surface spaced apart a height from the first surface, a length, and at least one groove that extends a depth into at least one of the first surface and the second surface. The depth of the groove is less than the height between the first surface and the second surface. The wear pad further comprises a first portion in which there exists a plurality of grooves. The plurality of grooves includes a pitch that defines the distance between the same structure or feature on adjacent grooves. Thus, in some embodiments, the wear pad includes a first portion with a given pitch between adjacent grooves and a second portion with a different pitch between the grooves in the second portion. 
     Also disclosed are embodiments of a construction vehicle. The construction vehicle includes a telescoping boom assembly that includes a first section and at least a second section configured to nest within and to extend from the first section. At least one wear pad is positioned between the first section and the second section. The wear pad includes a length, a first surface, and a second surface spaced apart a height from the first surface. A first portion of the wear pad includes a first bending plane positioned at a first distance between the first surface and the second surface. The wear pad also includes a second portion that includes a second bending plane positioned at a second distance between the first surface and the second surface, wherein the second distance is different than the first distance. Optionally, the height of the wear pad between the first surface and the second surface is substantially the same in the first portion and the second portion. Optionally, the construction vehicle is a crane. 
     Another embodiment of a construction vehicle includes a telescoping boom assembly that includes a first section and at least a second section configured to nest within and to extend from the first section. At least one wear pad is positioned between the first section and the second section. The wear pad includes a length, a first surface, and a second surface spaced apart a height from the first surface. A first portion of the wear pad includes a first bending stiffness. The wear pad also includes a second portion having a second bending stiffness, wherein the second bending stiffness is different than the first bending stiffness. Optionally, the height of the wear pad between the first surface and the second surface is substantially the same in the first portion and the second portion. Optionally, the construction vehicle is a crane. 
     In yet another embodiment, a construction vehicle includes a telescoping boom assembly that includes a first section and at least a second section configured to nest within and to extend from the first section. At least one wear pad is positioned between the first section and the second section. The wear pad includes a length, a first surface, and a second surface spaced apart a height from the first surface. The wear pad includes at least one groove that extends a depth into at least one of the first surface and the second surface. The wear pad optionally further comprises a first portion in which there exists a plurality of grooves. In some embodiments, the wear pad includes a first portion with a given pitch between adjacent grooves and a second portion with a different pitch between the grooves in the second portion. Optionally, the construction vehicle is a crane. 
     Also disclosed are methods of manufacturing a wear pad for positioning between a first section and a second section of a telescoping boom assembly. The method comprises obtaining a material having a length, a first surface, and a second surface spaced apart a height from the first surface. The method further comprises forming at least one groove that extends a depth into at least one of the first surface and the second surface, wherein the depth is less than the height between the first surface and the second surface. 
     Also disclosed are methods of installing a wear pad in position between a first section and a second section of a telescoping boom assembly of a crane. The method comprises providing a wear pad that includes a length, a first surface and a second surface spaced apart a height from the first surface, and at least one groove that extends a depth into at least one of the first surface and the second surface. The depth of the groove is less than the height between the first surface and the second surface. The method further comprises positioning the wear pad between the first section and the second section of a telescoping boom assembly. 
     Another embodiment of installing a wear pad in position between a first section and a second section of a telescoping boom assembly of a crane comprises providing a wear pad that includes a length, a first surface, and a second surface spaced apart a height from the first surface, and a first portion having a first bending stiffness. The wear pad includes a second portion having a second bending stiffness, wherein the second bending stiffness is different than the first bending stiffness. Optionally, the height of the wear pad between the first surface and the second surface is substantially the same in the first portion and the second portion. The method includes positioning the wear pad between the first section and the second section of a telescoping boom assembly. 
     Yet another method of installing a wear pad in position between a first section and a second section of a telescoping boom assembly of a crane includes providing a wear pad that includes a length, a first surface, and a second surface spaced apart a height from the first surface, and a first portion having a first bending plane. The wear pad includes a second portion having a second bending plane, wherein the position (i.e., the distance between the first surface and the second surface) of the second bending plane is different than the first bending plane. Optionally, the height between the first surface and the second surface is substantially the same in the first portion and the second portion. The method further includes positioning the wear pad between the first section and the second section of a telescoping boom assembly. 
     Yet another method of installing a wear pad in position between a first section and a second section of a telescoping boom assembly of a crane includes providing a wear pad that includes a length, a first surface, and a second surface spaced apart a height from the first surface. The wear pad includes at least a plurality of grooves that extends a depth into at least one of the first surface and the second surface, wherein the depth is less than the height between the first surface and the second surface. The plurality of grooves in a first portion has a first pitch and the plurality of grooves in a second portion has a second pitch. The method further includes positioning the wear pad between the first section and the second section of a telescoping boom assembly. 
     These and other advantages, as well as the invention itself, will become more easily understood in view of the attached drawings and apparent in the details of construction and operation as more fully described and claimed below. Moreover, it should be appreciated that several aspects of the invention can be used with other types of cranes, machines or equipment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a construction vehicle with a telescoping boom assembly. 
         FIG. 2  is a cross-section A-A of the telescoping boom assembly in  FIG. 1 . 
         FIG. 3  is a perspective view of a first section of a telescoping boom assembly and associated wear pad. 
         FIG. 4  is a perspective view of an embodiment of a wear pad in its uninstalled position. 
         FIG. 5  is a close-up perspective view of the wear pad in  FIG. 4 . 
         FIG. 6  is a perspective view of the wear pad in  FIG. 4  in its installed position. 
         FIG. 7  is a close-up perspective view of the wear pad in  FIG. 6 . 
         FIG. 8  is a perspective view of another embodiment of a wear pad in its uninstalled position. 
         FIG. 9  is a perspective view of the wear pad in  FIG. 8  in its installed position. 
         FIG. 10  is a close-up perspective view of the wear pad in  FIG. 9 . 
         FIG. 11  is a close-up cross-section view of the wear pad in  FIG. 6  installed in a telescoping boom assembly with associated shim. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be further described. In the following passages, different aspects of the embodiments of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous. 
       FIG. 1  illustrates a construction vehicle  10  that includes a telescoping boom assembly  15 . The construction vehicle  10  may be configured with ground engaging members  18 , such as wheels, tracks, rails, and the like to make the construction vehicle  10  mobile, or alternately the construction vehicle  10  may be a fixed, such as on a platform. 
     In some embodiments, the construction vehicle  10  is a mobile crane, as illustrated in  FIG. 1 . Of course, the construction vehicle  10  may be a teleloader or any other type of construction vehicle that includes a telescoping boom assembly  15 . 
     Illustrated in  FIG. 2  is a cross-section A-A of the telescoping boom assembly  15  in  FIG. 1 . The telescoping boom assembly  15  is rectangular in cross-section, but as will be appreciated embodiments of the invention may be employed with telescoping boom assemblies that are square, rectangular, oval, segmented, or include one or more portions with a radius of curvature that is the same or different from the radius of curvature of another portion of the telescoping boom assembly. 
     The telescoping boom assembly  15  includes a first section  20  and at least a second section  25  configured to nest within, most typically, or nest around the first section  20 . The second section  25  is capable of extending away from the first section  20 . Thus, in  FIG. 2 , the second section  25  would extend leftward and away from the first section  20  and the boom pivot  17  ( FIG. 1 ). Of course, the telescoping boom assembly  15  may include a plurality of nested sections. 
     At least one wear pad  30  is positioned between the first section  20  and the second section  25  of the telescoping boom assembly  15 . Optionally, brackets  50  coupled to one of the first section  20  and the second section  25 , are configured to at least one of receive and retain the wear pad  30  in position relative to the first section  20  or the second section  25  to which it is adjacent. 
     Another embodiment of a first section  120  of a telescoping boom assembly is illustrated in perspective view in  FIG. 3 . (Note, a second section is not illustrated, but typically would be similar in appearance to the first section  120  as one of skill in the art would understand.) In this instance, the first section includes a plurality of portions  121   a ,  121   b ,  121   c . Each portion  121   a ,  121   b ,  121   c  include a radius of curvature that varies from the radius of curvature of at least one of the other portions  121   a ,  121   b ,  121   c.    
     A wear pad  130  optionally is at least one of received within and retained in position by the bracket  150 . The bracket  150  optionally includes at least one or more positioning members  151   a ,  151   b ,  151   c . The positioning members  151   a ,  151   b ,  151   c  may be a tab, flange, recess, groove, ridge, or any other similar structure configured to receive and/or retain the wear pad  130 . The positioning members  151   a ,  151   b ,  151   c  may be integrally formed with each other and/or with the first section  120 . As illustrated in  FIG. 3 , the positioning members  151   a ,  151   b ,  151   c  include a variety of flanges, such as plate steel and/or plastic, such as positioning member  151   a  that extend inward and away from a first end  122 , and raised positioning members  151   b  and  151   c  that extend away from an inner surface  123  of the first section  120 . The positioning members  151   a ,  151   b ,  151   c  may be adjustably fixed to the first section  120  with an attachment device  152 , such as nuts, screws, bolts, slots and grooves, adhesives, and the like, that allow the positioning members  151   a ,  151   b ,  151   c  to be moved to accommodate manufacturing tolerances in the first section  120  and the wear pad  130 . 
     Turning to  FIGS. 4-7 , an embodiment of a wear pad  230  includes a first surface  232  and a second surface  234  spaced apart a height  236  from the first surface  232 . The wear pad  230  also includes a length  238  and a depth of  240 .  FIGS. 4 and 5  illustrate the wear pad  230  in the uninstalled position, while  FIGS. 6 and 7  illustrate the wear pad  230  in an installed shape and orientation. As illustrated in  FIGS. 4 and 5 , the height  236  and depth  240  are significantly less than the length  238 , which results in a wear pad  230  that is rectangular in shape. Optionally, the height  236  between the first surface  232  and the second surface  234  is substantially the same across at least one of the length  238  and a width  240  of the wear pad  230 . In yet other embodiments, the height  236  between the first surface  232  and the second surface  234  is configured to vary less than 10 percent of an average height across at least one of the length  238  and the width  240  of the wear pad  230 . 
     Various heights, lengths, and depths of the dimensions/measurements of the wear pad, however, can be used in various embodiments of the wear pad. Further, the terms height, depth, and length as used herein merely distinguish the various dimensions and do not connote the magnitude of a given dimension relative to the other dimensions. Consequently, wear pads of other shapes, including square, oval, round, and other geometric shapes are contemplated. In other shapes, such as ovals and circles, the major and minor axes correspond to the terms length and depth as appropriate. 
     The wear pad  230  can be made of any material  231  ( FIG. 4 ), although typically it is made of a wear-resistant material that has a relatively low coefficient of friction relative to other materials. In some embodiments, the material of the wear pad is a metal. In yet other embodiments, the material of the wear pad is a plastic, thermoplastic, thermoset, or other similar materials. For example, the material  231  may be nylon or nylon-based materials. Optionally, the material  231  includes a friction modifier (not illustrated) that reduces the coefficient of friction of the base material  231  further. The friction modifier optionally includes at least one of a lubricant applied to at least one of the first surface  232  and the second surface  234  of the wear pad  230  and a lubricant integral to the material  231  of the wear pad  230 . For example, the material  231  may be impregnated with molybdenum, and/or oils, and/or other wet and/or dry lubricants. 
     The wear pad  230  includes at least one groove or recess  242  in at least one of the first surface  232  and the second surface  234 . In some embodiments, the wear pad  230  includes a plurality of grooves  242 . The first surface  232  and the second surface  234  could be a top surface and bottom surface in some embodiments, while in alternative embodiments the first surface and the second surface could be a front and rear of the wear pad or a left side and a right side, for example. As illustrated in  FIG. 4 , the wear pad  230  optionally includes at least one groove  242   a  in the first surface  232  and at least another groove  242   b  in the second surface  234 . 
     The groove  242  extends at least partly across a dimension of the wear pad  230 . For example, the grooves  242   a  and  242   b  extend fully across the depth  240  of the wear pad  230 . In other embodiments, the grooves  240  extend only partly across the depth  240  and/or the length  238  of the wear pad  230 . As illustrated in  FIG. 4 , at least one groove  242  is oriented parallel to the depth  240  of the wear pad  230 , although the groove  242  or other grooves in the plurality of grooves may be parallel to another dimension, such as the height  236  or the length  238 , or not parallel to any of the dimensions. 
     The groove  242  extends a depth  244  into at least one of the first surface  232  and the second surface  234 , wherein the depth  244  is less than the height  236  between the first surface  232  and the second surface  234 . As illustrated in  FIG. 4 , the groove  242   a  in the first surface  232  extends a depth  244   a  into the first surface  232 , and the groove  242   b  extends a depth  244   b  into the second surface  234 , each depth  244   a  and  244   b  being less than the height  236 . Optionally, and as illustrated in  FIG. 5 , a sum of the depth  244   a  of the first groove  242   a  and the depth  244   b  of the second groove  242   b  is less than the height  236 . 
     Optionally, the wear pad  230  includes at least a portion  241  of the plurality of grooves  242  that are parallel to at least another portion  243  of the plurality of grooves  242 . Alternatively, the portion  241  of the plurality of grooves  242  may be only partially parallel, i.e., parallel over a segment or a length of the groove to another portion  243  of the plurality of grooves  242  (not illustrated), or in yet other embodiments a portion  241  of the plurality of grooves  242  may not parallel another portion  243  of the plurality of grooves  242  (not illustrated). 
     Referring to  FIG. 5 , at least one groove  242   a  optionally includes a first axis  248 . At least another groove  242   b  optionally includes a second axis  250 . In some embodiments, the first axis  248  and the second axis  250  are parallel. Optionally, the first axis  248  and the second axis  250  are in a plane parallel to at least one of the height  236 , the length  238 , or the depth  240 . Of course, the first axis  248  and the second axis  250  may not be parallel in other embodiments. 
     The groove  242  optionally includes a root  252  with a radius of curvature  253  in some embodiments. In other embodiments, the root  252  is the intersection of two planes. As illustrated by comparing  FIGS. 5 and 7 , the radius of curvature  253  of the root  252  may change between the uninstalled position of the wear pad ( FIG. 5 ) and the installed position ( FIG. 7 ). 
       FIG. 5  also illustrates an optional feature in which the at least one groove  242  includes a first width  254  proximate at least one of the first surface  232  and the second surface  234  and a second width  256  proximate the root  252  of the at least one groove  242 . In the uninstalled position illustrated in  FIG. 5 , the first width  254  is approximately the same as the second width  256 . In other embodiments, in the uninstalled position of the wear pad, the first width  254  is greater than the second width  256 , and yet in other embodiments the first width  254  is less than the second width  256 . The first width  254  and the second width  256  may change when the wear pad is positioned in the installed position, as illustrated in  FIG. 7 . 
     In those embodiments of a wear pad in which there exists a plurality of grooves  242 , there exists a pitch  260  ( FIG. 5 ) that defines the distance between the same structure or feature on adjacent grooves  242 . Thus, in some embodiments, the wear pad  230  includes a first portion  262  with a given pitch  260  between adjacent grooves  242  and a second portion  264  with a different pitch  260 , as illustrated in  FIG. 4 .  FIG. 3  also illustrates the concept in which the pitch  160  of the grooves  142  differs between a first portion  162  and a second portion  164 . 
     The wear pad  230  may include at least a first bending plane  270  positioned a first distance  271  between the first surface  232  and second surface  234 , as illustrated in  FIG. 4 . In some embodiments there exists a second bending plane  272  positioned a second distance  273  between the first surface  232  and the second surface  234 . A bending plane or neutral plane is the plane in which neither compressive forces nor tensile forces act. In  FIGS. 4-7 , the first bending plane  270  and the second bending plane  274  are equidistant between the first surface  232  and the second surface  234  so that the first distance  271  and second distance  273  are substantially the same (e.g., within 10% of the distance of the other). In other embodiments, however, and as will be discussed below, the first distance is different from the second distance. 
     The wear pad  230  also may include a first portion  280  that includes at least one groove  242  and has a first bending stiffness, as illustrated in  FIG. 4 . The wear pad  230  also may have a second portion  282  that has a second bending stiffness. The second portion may have none, one, or a plurality of grooves  242  within the second portion  282 . Further, the bending stiffness of the second portion  282  may be different than the bending stiffness of the first portion  280 , which is typically the case, although in other embodiments the bending stiffness in the first portion  280  and the second portion  282  are the same. As illustrated in  FIG. 4 , the bending stiffness of the second portion  282  is greater than the bending stiffness of the first portion  280 . 
     The bending stiffness is the resistance of the wear pad against bending deformation, such as may occur when installing the wear pad  230  and once the wear pad  230  is installed between the first section  20  and the second section  25  of the telescoping boom assembly  15 . The bending stiffness is a function of the elastic modulus of the wear pad  230  (i.e., a function of the material  231 ), the area moment of inertia of the cross-section of the wear pad  230  about the axis of interest, the length of the wear pad  230 , and the boundary conditions (i.e., the forces applied at the ends and surfaces of the wear pad  230 , amongst other locations). 
     The first portion  262  and/or the second portion  264  with the pitch of the grooves  242  of the wear pad  230  may be the same portion or a different portion from one or more of the first and second portions  270 ,  272  with the bending planes. Likewise, the first portion  262  and/or the second portion  264  may be the same portion or a different portion from one or more of the first and second portions  280 ,  282  of bending stiffness. Similarly, the first portion  270  and/or the second portion  272  of the bending plane may be the same portion or a different portion from one or more of the first and second portions  280 ,  282  of bending stiffness. 
     Turning to  FIGS. 8-10  is another embodiment of a wear pad  330 . The wear pad  330  optionally incorporates any combination, including all, of the features recited above with respect to wear pad  230 . Thus, the discussion of wear pad  330  focuses on the apparent differences. 
     The wear pad  330  includes a plurality of grooves  342  on both the first surface  332  and the second surface  334 . The wear pad  330  includes a first portion  362  with a given pitch between adjacent grooves  342 , a second portion  364  with another pitch between adjacent grooves  342 , and a third portion  366  with yet another pitch between adjacent grooves  342 . Thus, it can be seen that there may be any number of portions of a wear pad with given pitches between grooves, which may be different and/or the same (e.g., the pitch in the first portion  362  is the same as the pitch in the second portion  364 , which are both different from the pitch in the third portion  366 ). In wear pad  330 , each of the pitches in the first portion  362 , second portion  364 , and third portion  366  are different from the others. 
     The wear pad  330  may include at least a first bending plane  370  positioned a first distance  371  between the first surface  332  and second surface  334 , as illustrated in  FIG. 8 . In some embodiments there optionally exist one or more additional bending planes. In the wear pad  330  there exists a second bending plane  372  positioned a second distance  373  between the first surface  332  and the second surface  334 . There also exists a third bending plane  374  positioned a third distance  375  between the first surface  332  and the second surface  334 . As illustrated in  FIG. 8 , the first distance  371 , the second distance  373 , and the third distance  375  are all different from each other. 
     Optionally, the wear pad  330  also may include a first portion  380  that includes at least one groove  342  and has a first bending stiffness, as illustrated in  FIG. 8 . The wear pad  330  also may have one or more additional portions. For example, the wear pad  330  includes a second portion  382  that has a second bending stiffness. The second portion may have none, one, or a plurality of grooves  342  within the second portion  382 . The wear pad  330  includes, in this example, a third portion  384  that has a third bending stiffness. The bending stiffness of the second portion  382  and the third portion  384  may be different than the bending stiffness of the first portion  380 , which is typically the case; although in other embodiments the bending stiffness in one or more of the portions may be the same. As illustrated in  FIG. 8 , the bending stiffness of the second portion  382  is greater than the bending stiffness of the first portion  380  and the third portion  384 , and the bending stiffness of the third portion  384  is greater than the bending stiffness of the first portion  380 . 
     Turning to  FIG. 10 , additional optional differences with the wear pad  330  are identified. At least one groove  342   a  optionally includes a first axis  348 . At least another groove  342   b  optionally includes a second axis  350 . In contrast to the wear pad  230 , the first axis  348  and the second axis  350  may not be parallel and/or may not lie in a plane parallel to one of the height, length, or depth of the wear pad  330 . Thus, in this configuration the sum of the depth  344   a  of the groove  342   a  and the depth  344   b  of the groove  344   b  is greater than the depth  336  of the wear pad  330  because the grooves  342   a  and  342   b  are offset from each another. 
     In addition, the groove  342   a  and  342   b  optionally include a root  352  that is an intersection of two planes, at least within manufacturing tolerances. Thus, any root  352  has a minimal radius of curvature in its uninstalled position illustrated in  FIG. 8 . As illustrated by comparing  FIGS. 8 and 10 , the radius of curvature of the root  352  may change between the uninstalled position of the wear pad  330  ( FIG. 8 ) and the installed position ( FIGS. 9 and 10 ). 
     Turning to  FIG. 11 , the construction vehicle  10  optionally includes at least one shim  590 . Illustrated in  FIG. 11  is a cross-section of a first section  520  and the second section  525  of a telescoping boom assembly similar to the telescoping boom assembly  15  in  FIG. 1 . A wear pad  530  with at least one groove  542  is positioned between the first section  520  and the second section  525 . A shim  590 , which may be manufactured from any material, but typically is formed of a thermoset, thermoplastic, metal, or other material, such as Teflon, may be positioned between one of the wear pad  530  and the first section  520  (most typically) or the wear pad  530  and the second section  525 . The shim  590  allows for a better fit and accounts for manufacturing tolerances when positioning the wear pad  530  between the first section  520  and the second section  530 . 
     The shim  590  includes at least a first surface  592  and a second surface  594  spaced apart from the first surface  592 . Optionally, the shim  590  includes one or more ridges or protrusions  596  extending away from at least one of the first surface  592  and the second surface  594 . As illustrated, the ridge  596  extends from the first surface  592  and is configured to be received in or extend into at least one of the grooves  542 . In other words, the ridge  596  is dimensionally shaped (height, width, radius of curvature at a tip of the ridge) so as to fit within—whether loosely or with an interference fit—at least one groove  542 . 
     Methods of manufacturing a wear pad are also disclosed. The method includes obtaining a material having a length, a first surface, and a second surface spaced apart a height from the first surface. The method further includes forming at least one groove that extends a depth into at least one of the first surface and the second surface, wherein the depth is less than the height between the first surface and the second surface. The groove may be formed by at least one of milling, sawing, molding, and ablating the material. 
     Optionally, the method includes forming a plurality of grooves. In such methods, at least a portion of the plurality of grooves may be formed parallel to at least another portion of the plurality of grooves. Optionally, the pitch of the plurality of grooves in a first portion of the material may differ from the pitch of the plurality of grooves in a second portion of the material. 
     Further, the step of forming at least one groove may include forming at least one groove in the first surface and forming at least another groove in the second surface. In such embodiments, the at least another groove extends a depth into the second surface less than the height between the first surface and the second surface. 
     The step of forming the at least one groove may include forming the at least one groove to include a first axis and forming the at least another groove to include a second axis, wherein the first axis and the second axis are parallel, and wherein a sum of the depth of the first groove and the depth of the second groove is less than the height between the first surface and the second surface. 
     The step of forming the at least one groove may include forming a root that includes a radius of curvature in the at least one groove. 
     The step of forming the at least one groove may include forming the at least one groove to include a first width proximate at least one of the first surface and the second surface and a second width proximate a root of the at least one groove, and wherein the first width is greater than the second width. 
     The step of forming the at least one groove may include orienting the at least one groove to be parallel to the length of the material. 
     The method may further include obtaining a material that includes a friction modifier integral to the material. Likewise, the method optionally includes applying a lubricant to at least one of the first surface and the second surface. 
     The method optionally includes obtaining or forming a material such that the height between the first surface and the second surface is substantially the same across at least one of the length and the width of the material. Optionally, the height between the first surface and the second surface is configured to vary less than 10 percent of an average height across at least one of the length and the width of the material. 
     The method optionally includes modifying a position of a first bending plane of a first portion of the material such that the first bending plane differs from a second bending plane of a second portion of the material. 
     The method also optionally includes modifying a first bending stiffness of a first portion of the material such that the first bending stiffness differs from a second bending stiffness of a second portion of the material. 
     Methods of installing a wear pad in position between a first section and a second section of a telescoping boom assembly of a crane are also disclosed. The method includes providing a wear pad that includes a length, a first surface and a second surface spaced apart a height from the first surface, and at least one groove that extends a depth into at least one of the first surface and the second surface, wherein the depth is less than the height between the first surface and the second surface. The method also includes positioning the wear pad between the first section and the second section of a telescoping boom assembly. 
     Yet another method of installing a wear pad in position between a first section and a second section of a telescoping boom assembly of a crane includes providing a wear pad that includes a length, a first surface and a second surface spaced apart a height from the first surface, a first portion having a first bending stiffness, and a second portion having a second bending stiffness, wherein the second bending stiffness is different than the first bending stiffness. Optionally, the height between the first surface and the second surface is substantially the same in the first portion and the second portion. The method further includes positioning the wear pad between the first section and the second section of a telescoping boom assembly. 
     Yet another method of installing a wear pad in position between a first section and a second section of a telescoping boom assembly of a crane includes providing a wear pad that includes a length, a first surface and a second surface spaced apart a height from the first surface, a first portion having a first bending plane, and a second portion having a second bending plane, wherein the position (i.e., the distance between the first surface and the second surface) of the second bending plane is different than the first bending plane. Optionally, the height between the first surface and the second surface is substantially the same in the first portion and the second portion. The method further includes positioning the wear pad between the first section and the second section of a telescoping boom assembly. 
     Yet another method of installing a wear pad in position between a first section and a second section of a telescoping boom assembly of a crane includes providing a wear pad that includes a length, a first surface and a second surface spaced apart a height from the first surface, and at least a plurality of grooves that extends a depth into at least one of the first surface and the second surface, wherein the depth is less than the height between the first surface and the second surface. The plurality of grooves in a first portion has a first pitch and the plurality of grooves in a second portion has a second pitch. The method further includes positioning the wear pad between the first section and the second section of a telescoping boom assembly. 
     The methods of installing the wear pad optionally include applying a lubricant to at least one of the first surface and the second surface of the wear pad. 
     The methods of installing the wear pad optionally include positioning at least one shim, the at least one shim including at least one ridge, such that the ridge extends at least partially into the at least one groove of the wear pad. 
     Optionally, the positioning of the wear pad in the various methods further includes one of (a) positioning the wear pad within an interior of the first section of the telescoping assembly and positioning the wear pad onto an exterior of the second section of the telescoping assembly and (b) positioning the second section of the telescoping assembly within the first section of the telescoping assembly. 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.