Abstract:
In a wear assembly for securing wear members to excavating equipment, a spool is used with a wedge to hold the wear member in place. The spool is formed with at least one laterally extending arm at its upper end in lieu of an axial arm such as used in a conventional C-shaped spool. In this way, the spool can be easily supported in the assembly as the wedge is installed. The spool does not fall through the opening and no special care is needed to prevent it from falling. The spool also holds itself in place when the wedge is driven into the passage. As a result, installation of the wear assembly is easier and less hazardous. In addition, the lateral support reduces the risk that the spool will suffer spreading.

Description:
FIELD OF THE INVENTION 
     The present invention pertains to a wear assembly for securing a wear member to an excavating bucket or the like. 
     BACKGROUND OF THE INVENTION 
     Wear members in the form of adapters, shrouds, and the like are ordinarily secured to the front edge of an excavating bucket. Such wear members are commonly subjected to harsh conditions and heavy loading. Accordingly, the wear members wear out over a period of time and need to be replaced. The wear members are made to withstand the rigors of a digging operation and still be capable of replacement when worn. Whisler-style locking arrangements have long been in use for mechanically attaching wear members to the lip of a bucket. Such locks generally consist of a wedge and a C-shaped clamp or spool. While the wedge is typically hammered into the assembly, U.S. Pat. Nos. 4,433,496 and 5,964,547 disclose arrangements wherein the wedge is drawn into place under pressure from a screw. U.S. Patent Application Publication No. 2004/0216336 discloses a lock where the wedge is a conical threaded member that is turned to drive the wedge into and out of the assembly. 
       FIG. 19  discloses one example of a conventional Whisler shroud  21  attached to a lip  16 . As seen in the drawing, the lip includes a digging edge  25 , an inner surface  27  and an outer surface  29 . A hole  31 , which is elongated axially, extends through the lip at a location rearward of the digging edge. Hole  31  has a generally straight front wall  33  and a rear wall  35  that includes a step  37 . The step includes a tapered surface  39  that tapers away from inner surface  27  as it extends rearward away from digging edge  25 . 
     Shroud  21  wraps around the front end  25  of lip  16  with an inner leg  41  extending along inner surface  27  and an outer leg  43  extending along outer surface  29 . Inner leg  41  includes an through-hole  47  which generally aligns with hole  31  when the shroud  21  is put on the lip. The hole  31  and opening  47  collectively define a passage  49  into which is received a lock  51  adapted to releasably hold the shroud  21  to the lip  16 . Through-hole  47  includes a step  53  adjacent wear surface  55  of inner leg  41 . As with step  37  in hole  31 , step  53  includes a tapered surface  57  that tapers away from inner surface  27  as it extends rearward away from the digging edge  25 . In this way, tapered surfaces  39 ,  57  diverge rearwardly at generally equal inclinations relative to a central axis of the lip  16 . 
     Lock  51  includes a wedge  61  and a clamp or spool  63 . Spool  63  has a C-shaped configuration with a generally vertical body  65  and two axially extending arms  67 ,  69 . Upper arm  67  is adapted to fit within step  53 , while lower arm  69  is adapted to fit within step  37 . Each arm  67 ,  69  is formed with an inclined inner wall  71 ,  73  that conforms and sets against a respective tapered surface  39 ,  57 . The front surface of body  65  defines a ramp surface  75  that is inclined forward (relative to vertical) as it extends downward in passage  49 . Wedge  61  has front and rear converging walls  81 ,  83 . Converging wall  83  abuts ramp surface  75  during installation and use in order to produce a tight fit of lock  51  in passage  49 . As shown in  FIG. 19 , converging wall  83  and ramp surface  75  are formed with interlocking ridges  85  to ensure a stable and sure contact between the surfaces. 
     For installation, shroud  21  is first fit on lip  16  so that through-hole  47  generally aligns with hole  31 . Spool  63  is then placed within the defined passage  49  with arms  67 ,  69  inserted into steps  37 ,  53 . On account of the incline of tapered wall  57  and inner wall  71 , the spool tends to slide forward and downward through passage  49  if not held in place. As a result, the spool at times can slip through the lip and fall to the ground requiring the worker to retrieve it from under the bucket. This can be a difficult process particularly if installation is being done at night. In addition, crawling under the bucket can place the worker in a potentially hazardous position. 
     The spool  63  must therefore be held in place while the wedge  61  is inserted into the assembly. In order to withstand the rigors of the digging operation, the wedge must be fit very tightly into passage  49 . A large hammer is required to install the wedge into the assembly, which places the worker in a potentially hazardous position for injury from pieces that may fly off during hammering. 
     As wedge  61  is forced into passage  49 , arms  67 ,  69  are pushed rearward over tapered walls  39 ,  57 . This causes shroud  21  to be pulled tight against digging edge  25  and inner leg  41  to be pinched against lip  16 . This tight fit is intended to resist heavy and diverse loading that may be applied to the wear member. The large forces applied to the spool arms can result in spreading of the arms. Such spreading reduces the grip of the lock on the wear member and can at times lead to failure of the lock. 
     SUMMARY OF THE INVENTION 
     The present invention pertains to an improved wear assembly for securing wear members to excavating equipment or the like. 
     The present invention regards a lock assembly for securing a wear member to a base. For example, the inventive lock is useful in securing a shroud or other wear member to a lip of an excavating bucket to avoid problems experienced in the prior art. 
     In one aspect of the invention, an improved spool is used with a wedge to hold the wear member in place. The spool is formed with at least one laterally extending arm at its upper end in lieu of an axial arm such as used in a conventional C-shaped spool. In this way, the spool can be easily supported in the assembly as the wedge is installed. The spool does not fall through the opening and no special care is needed to prevent it from falling. As a result, installation of the wear assembly is easier and less hazardous. In addition, the lateral support reduces the risk that the spool will suffer spreading. 
     In a preferred construction, an upper lateral arm extends outward from each side of a spool body to generally define a T-shaped configuration. The spool with upper lateral arms can be used with a variety of lower arms, such as an axial arm, lower lateral arms or other supports adapted to engage a lower leg or lower portion of the lip. In any of the combinations, the inner walls of the upper and lower arms are preferably inclined outward in a rearward direction to apply the rearward pinching force generally provided in Whisler-style locks. 
     Similarly, in another aspect of the invention, the wear member is formed with an opening having at least one spool support for receiving and holding a spool with a lateral arm. Preferably, the wear member is formed with a side recess as the spool support to each side of the lock-receiving opening. As noted above, this new construction enables the wear member to be assembled on the lip or other equipment more easily and with less risk to the user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an axial cross-sectional view of a wear assembly in accordance with the present invention secured to a lip of a bucket. 
         FIG. 2  is an enlarged, partial cross-sectional view of the wear assembly. 
         FIG. 3  is a partial top view of the wear assembly. 
         FIG. 4  is a perspective view of the wear assembly with an axial cross-section. 
         FIG. 5  is a side view of a spool in accordance with the present invention. 
         FIG. 6  is a front perspective view of the spool. 
         FIG. 7  is a rear perspective view of the spool. 
         FIG. 8  is a perspective view of a wedge in accordance with the present invention. 
         FIG. 9  is a perspective view of a lock assembly in accordance with the present invention. 
         FIG. 10  is a perspective view of a wear member in accordance with the present invention. 
         FIG. 11  is an enlarged, partial perspective view of the through-hole in the wear member. 
         FIG. 12  is an upper perspective view of an alternative wear assembly of the present invention without the wedge. 
         FIG. 13  is a bottom perspective view of the alternative wear assembly without the wedge. 
         FIG. 14  is an exploded perspective view of the alternative wear assembly without the wedge. 
         FIG. 15  is a perspective view of the alternative wear assembly with the spool partially installed into the wear assembly. 
         FIG. 16  is a perspective view of the alternative wear member. 
         FIG. 17  is a bottom perspective view of a portion of a lip adapted to be used with the alternative wear assembly. 
         FIG. 18  is an axial cross-sectional view of a second alternative wear assembly in accordance with the present invention. 
         FIG. 19  is an axial cross-sectional view of a wear assembly of the prior art. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention pertains to a wear assembly  100  in which a wear member  102  is releasably attached to excavating equipment  103  ( FIGS. 1-4 ). In this application, wear member  102  is described in terms of a shroud that is attached to a lip of an excavating bucket. However, wear member  102  could be in the form of other kinds of products (e.g., adapters, wings, etc.) attached to other equipment. Moreover, relative terms such as forward, rearward, up or down are used for convenience of explanation with reference to the drawings; other orientations are possible. 
     In one embodiment ( FIGS. 1-4 ), shroud  102  fits on a conventional lip  16 . Although the lip in  FIG. 1  is slightly different than in  FIG. 19 , for convenience, the same numbers are used to identify the lip and its features. The particular lip construction is not critical for the invention, and an assembly in accordance with the present invention can be used with a wide range of lips. 
     Lock  104  includes a wedge  106  and a spool or clamp  108  to releasably secure shroud  102  to lip  16  ( FIGS. 1-9 ). Spool  108  includes a body  110 , at least one and preferably two upper arms  112 , and a lower arm  114 . Lower arm  114  is formed in the same manner as lower arm  69  in a conventional spool; i.e., lower arm  114  extends axially rearward from body  110 . Lower arm  114  also has an inclined inner surface  116  that sets against tapered wall  39  formed in the lip. However, unlike a conventional spool, spool  108  includes at least one laterally extending upper arm  112  to engage shroud  102 . In the preferred construction, an upper lateral arm  112  extends outward from each side  118  of body  110  in a transverse direction so as to define a generally T-shaped configuration with body  110 . 
     In the preferred construction, wedge  106  has a rounded, conical shape with a helical thread  120  formed on its exterior surface  122 , preferably in the form of a helical groove. The wedge is formed generally in accordance with the wedge disclosed in co-pending U.S. Patent Application Publication No. 2004/0216336 and U.S. patent application Ser. No. 10/824,490, which are both incorporated herein by reference. Spool  108  includes a front ramp surface  126 , inclined to vertical, to abut exterior surface  122  of wedge  106 . Ramp surface  126  preferably includes a trough  128  with a concave surface that generally conforms to the curve of wedge  106 , but other concave configurations could be used to provide the desired support to the wedge. Other shaped ramp surfaces may also be used so long as the abutment of the wedge and spool is sufficient and stable in the assembly during use. The trough may extend substantially along the entire length of body  110  or only part way. In either case, a thread formation  130  is provided on ramp surface  126 , and in this embodiment, within trough  128 , to mate with thread  120  of wedge  106 . Thread formation  130  may extend the entire length of trough  128  as shown or along only a part of the length. 
     Wear member  102  is formed with a front working end  134 , an inner leg  136  and an outer leg  138  ( FIGS. 1-4  and  10 - 11 ). As with known shrouds, inner leg  136  is preferably longer than outer leg  138 , but other arrangements could be used (see, e.g.,  FIG. 18  where the legs are the same length). Inner leg  136  includes a through-hole  140  that generally aligns with hole  31  in lip  16  to collectively define a passage  141 . However, unlike conventional shrouds  21 , through-hole  140  includes at least one and preferably two spool supports  142  extending along sides  144  ( FIGS. 10 and 11 ). In a preferred construction, spool supports  142  are recesses or steps that extend partially through inner leg  136  within through-hole  140 . In the preferred construction, each spool support or recess  142  includes a bearing surface  146  and a stop  148  in a generally V-shaped configuration, though other shapes could be used. Bearing surface  146  is preferably inclined away from lip  16  as it extends rearward away from digging edge  25  but other configurations could be used. The inclination of bearing surface  146  relative to the lip is preferably the same as tapered or inclined wall  39  in lip  16 , albeit in the opposite direction. Stop  148  is preferably inclined away from the lip in the forward direction. As one example, bearing surface  146  sets about 18 degrees relative to lip  16 , and about 90 degrees relative to stop  148 ; although a wide variation of each angle could be used. 
     Each lateral arm  112  of spool  108  is received into a corresponding spool support or recess  142  of shroud  102  ( FIGS. 1-4 ). In the preferred construction, each upper arm  112  includes a bearing surface  152  and a stop  154  to complement and engage bearing surface  146  and stop  148  of the recess  142  into which it is received ( FIGS. 3 ,  4 ,  10  and  11 ). Bearing surface  152  is inclined to generally conform to the inclination of bearing surface  146  in shroud  102 , and stop  154  to generally conform to the inclination of stop  148 , although other shapes are possible. When spool  108  is installed into passage  141 , bearing surface  152  of spool  108  sets against bearing surface  146  of shroud  102 , and stop  154  against stop  148 . The engagement of surfaces  146 ,  152  and  148 ,  154  prevent the spool from falling through the passage  141 . The V-shaped configuration of bearing surfaces  146 ,  152  and stops  148 ,  154  also hold spool  108  in place as wedge  106  is inserted. 
     To install lock  104 , spool  108  is first placed into passage  141  such that lower arm  114  is set in step  37  and upper arms  112  are set in spool supports or recesses  142 . The recesses  142  hold the spool in its proper position for receiving the wedge without any additional holding by a worker or anything else. As a result, the spool no longer falls through the lip to the ground. Additionally, workers are not forced into hazardous conditions when installing the locks. 
     Following insertion of spool  108 , wedge  106  is installed into passage  141  between front wall  33  of hole  31  and ramp surface  126  of spool  108 . In the preferred construction, wedge  106  includes a tool engaging structure  156  such as a socket for a wrench. Thread formation  120  of wedge  106  is engaged with thread formation  130  of spool  108 , and the wedge rotated about its axis  158  to draw the wedge into passage  141 . As the wedge is driven into the opening, spool  108  is pushed rearward such that bearing surfaces  152  press against bearing surfaces  146 , and inner surface  116  presses against tapered wall  39 . The upper and lower arms  112 ,  114  of spool  108 , then, function to push shroud  102  rearward into a tight fit with lip  16  and to pinch inner leg  136  against the inner surface  27  of lip  16  for a secure attachment of the wear member to the bucket. The positioning of the upper arms  112  closer to the vertical axis of the spool also reduces the tendency for the upper and lower arms to spread apart during use; that is, this new orientation of the upper arms reduces the couple tending to spread the arms in conventional spools such that upper and lower arms  112 ,  114  of spool  108  experience less deformation in use. 
     Spool  108  preferably includes a cavity  160  in trough  128  ( FIG. 6 ). A retainer  162  preferably formed of a rubber, foam or other elastomer is fit within the cavity to press outward against the exterior surface  122  of wedge  106 . The retainer provides resistance to prevent loosening of the wedge as the bucket is used in digging operations. Of course, other retainers could also be used to prevent loosening. 
     In an alternative embodiment ( FIGS. 12-17 ), spool  108   a  is formed with lower lateral arms  114   a  as well as upper lateral arms  112   a . The lip  16   a  is, then, formed with lower spool supports  37   a  ( FIG. 17 ) rather than the conventional axial step  37  ( FIG. 19 ). Upper lateral arms  112   a  can retain the same structure as arms  112 . Spool  108   a  is turned ninety degrees for installation into passage  141   a  ( FIGS. 14 and 15 ). Specifically, spool  108   a  is initially turned so that lower lateral arms  114   a  extend generally parallel to the rearward extension of inner leg  136   a  of wear member  102   a , i.e., forward and rearward relative to passage  141   a . In this way, the spool can be inserted into passage  141   a  until the lower arms can be set in side steps  37   a . Side steps  37   a  are formed in the outer surface of lip  16  to have the same construction as side steps  142  described above for shroud  102 . Shroud  102   a  is formed with asymmetrical side steps or recesses  142   a ,  142   a ′ to accommodate turning of spool  108   a  when placing lower arms  114   a  into side steps  37   a  ( FIGS. 12 ,  14  and  15 ). Specifically, step  142   a  preferably has a longer axial shape than step  142   a ′, and no stop, to accommodate the swinging of the front upper lateral support  112   a  (during installation) into step  142   a . Step  142   a ′ has a bearing surface and stop essentially the same as steps  142 . 
     Other modifications can also be made to the lip, lock or wear member. As examples only, the lower leg of the wear member can be extended and provided with a recess(s) for receiving the lower arm(s) or the spool instead of the lip structure ( FIG. 18 ), such as in U.S. Patent Application Publication No. 2004/0216334, which is incorporated herein by reference. The shapes of the upper and lower spool supports along with the configuration of the bearing surfaces and stops could be altered. A hammered wedge could be used with a spool in accordance with the present invention instead of a rotating wedge. A wedge driven by a separate screw member or composed of multiple parts that apply an expansion force could also be used with a spool utilizing the novel lateral arms. Additionally, various inserts (such as between the front wall of the hole in the lip and the wedge) could be included in the through-holes to improve the locking or wear of the assembly.