Abstract:
Work machines having linkages may need to have the linkage assembly locked in a predetermined position to prevent damage to an implement attached to the work machine, to prevent tipping of the work machine, to operate the implement, or other reasons. Locking the linkage assembly, however, can create significant loads on the linkage assembly. The disclosed method and apparatus is for a work machine that comprises a chassis, at least one linkage assembly attached to the work machine, at least one restraint having a first-end portion and a second-end portion, the second-end portion being attached to the chassis and the first-end portion being attached to the linkage assembly, the restraint transferring a load from the linkage assembly to the chassis.

Description:
TECHNICAL FIELD 
   This invention relates generally to a restraint of a work machine, and, more particularly, to a linkage assembly restraint that transfers a load to a chassis of the work machine. 
   BACKGROUND 
   Work machines such as wheeled loaders, integrated tool carriers, and other work machines have linkage assemblies for raising, lowering, and tilting several different types of implements. The linkage assembly may need to be locked in a predetermined position to prevent damage to the implement and prevent tipping of the work machine. A restraint is used to lock the linkage assembly in position preventing it from being raised, lowered, or tilted. Once the linkage assembly is locked in the predetermined position there is a significant amount of load placed on the linkage assembly, links, lift arms, and levers. The load is caused by several factors such as the weight of the implement, the implement&#39;s distance from the work machine, and the vibration of the implement as the work machine moves. 
   One known linkage assembly restraint design is disclosed in U.S. Pat. No. 5,169,277 issued to Orser and Dubé on Dec. 8, 1992. The linkage assembly restraint includes a lock for selectively securing the lift arm to the vehicle body, when the lift arm is lowered. The lock includes a means for releasably and automatically locking the lift arm to the vehicle body at a position remote from the pivot when the lift arm is lowered. This design, however, does not permit a substantial load to be transferred from the lift arm to the chassis of the work machine and may result in significant loads being placed on the lift arm. Additionally, this design does not lock the tilt linkage assembly of the work machine in place and prevent the tilt function. 
   SUMMARY OF THE INVENTION 
   In one aspect of the present invention, a work machine comprises a chassis, at least one linkage assembly attached to the work machine, at least one restraint having a first-end portion and a second-end portion, the second-end portion being attached to the chassis and the first-end portion being attached to the linkage assembly, the restraint transferring a load from the linkage assembly to the chassis. 
   In another aspect of the present invention, a method of restraining at least one linkage assembly of a work machine having a chassis, the method comprises providing at least one restraint having a first-end portion and a second-end portion, moving the linkage assembly of the work machine to a predetermined position, attaching the second-end portion of the restraint to the chassis of the work machine, attaching the first-end portion of the restraint to the linkage assembly, and transferring a load from the linkage assembly to the chassis through the restraint. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference may be made to the accompanying drawings in which: 
       FIG. 1  is a diagrammatic side view of a linkage assembly of a work machine with restraints attached to a chassis and the linkage assembly of the work machine; 
       FIG. 2  is a diagrammatic top view of the linkage assembly of the work machine with the restraints attached thereto; and 
       FIG. 3  is a diagrammatic side view of the linkage assembly of the work machine with an alternate embodiment of the restraints attached to the chassis and linkage assembly of the work machine. 
   

   DETAILED DESCRIPTION 
   Referring to the drawings, depicted in  FIG. 1  is a chassis  100  of a work machine (not shown) such as an integrated toolcarrier, a wheel loader, skid steer loader, or other suitable work machine. Front  106  and rear axles (not shown) are attached to the chassis  100 . A vertical coupler  109  is attached to each side of the chassis  100  (only one being shown) by such processes as welding, using mechanical fasteners, or another suitable attachment process. Linkage assembly  115  has a first-end portion  118  and a second-end portion  121 , has its first-end portion  118  pivotally attached between the vertical coupler  109  by bolting it thereto, and has its second-end portion  121  pivotally connectable to an implement  124  (a portion of which is shown in  FIG. 1 ), such as a mower, bucket, broom, tiller, auger, hammer, shear, or other implement. The linkage assembly  115  includes at least one tilt linkage assembly  125  and at least one lift arm  126 . The tilt linkage assembly  125  includes a pair of actuators, such as hydraulic cylinders  127 ,  130 , attached to the linkage assembly  115  so as to rotate the implement  124  relative to linkage assembly  115  and a plurality of other linkages  131 . In the embodiment shown, four other linkages  131  are used (only three of which are visible). It should be understood, however, that any number of other linkages may be used. 
   Referring further to  FIG. 1 , a pair of actuators, such as hydraulic cylinders  133 ,  136 , each having a rod end  139  and a cylinder end  142 , are used to raise and lower the linkage assembly  115 , or more specifically, to raise and lower the lift arm  126 . The rod ends  139  are attached to the linkage assembly  115  in proximity to the second-end portion  121  of the linkage assembly  115  and the cylinder ends  142  are attached to the vertical couplers  109 . Removably attached to the rod end  139  of each of the hydraulic cylinders  133 ,  136  is a collar  160  that abuts against the cylinder end  142  of the hydraulic cylinders  133 ,  136  when the linkage assembly  115  is locked in a predetermined position. 
   Finally, removably attached to the linkage assembly  115 , including the tilt linkage assembly  125 , and the chassis  100  of the work machine is at least one restraint  145 . The restraint  145  has a first-end portion  148  and a second-end portion  151 . For exemplary purposes herein, two restraints  145  are shown being utilized herein. The second-end portions  151  of the restraints  145  are removably attached to the chassis  100  of the work machine by using a fastener such as a bracket  153  and a plurality of bolts  154 ,  155 . More specifically, the second-end portions  151  of the restraints  145  are removably attached to that portion of the chassis  100  that comprises the axle  106  using the brackets  153  and the plurality of bolts  154 ,  155 . The brackets  153  have a first side  153   a  and a second side  153   b . The first sides  153   a  are removably attached to the axle  106  by the use of bolts  154  and the second sides  153   b  are removably attached to the second-end portions  151  of the restraints  145  by the use of bolts  155 . 
   As seen in  FIG. 2 , the first-end portions  148  of the restraints  145  are removably attached to the linkage assembly  115 . The first-end portions  148  each include a hook  255  that fits over the linkage assembly  115  so as to removably attach the first-end portions  148  to the linkage assembly  115 . Each first-end portion  148  further includes an aperture  257  in the hook  255  that is threaded to accept a mating bolt  256 . Bolts  256  are threaded through apertures  257  so that the bolts  256  contact the linkage assembly  115 . The friction created by the contact of the bolts  256  and the linkage assembly  115  prevents the first-end portions  148  from sliding off the linkage assembly  115  or substantially traveling from their location. Removably attaching the restraints  145  and the collars  160  locks the linkage assembly  115  in the predetermined position and substantially restrains the linkage assembly  115  from traveling from the predetermined position, including up and down travel and tilt. More specifically, the restraints  145  prevent motion of the tilt function and lift function of the linkage assembly  115 . 
   Depicted in  FIG. 3  is an alternate embodiment wherein the restraints  145  include coupling members  303  and hook members  306 , the second-end portions  151  being the coupling members  303  and the first-end portions  148  being the hook members  306 . The coupling members  303 , having first-end portions  309  and second-end portions  312 , have their first-end portions  309  removably attached to the chassis  100  of the work machine, or more particularly, to that portion of the chassis  100  that comprises the axle  106  as described above. Alternatively, the coupling member  303  may be attached to the chassis  100  or axle  106  by such process as welding. Further, the second-end portions  312  have apertures (not shown); the apertures being threaded so as to accept a mating bolt  322 . The hook members  306  have first-end portions  315  and second-end portions  318 . The second-end portions  318  of the hook members  306  have apertures  320  and are removably attached to the second-end portions  312  of the coupling members  303  by the use of fasteners, such as bolts  322  sized to fit within the apertures of the coupling member  303  and the apertures  320  of the hook members  306  and are threaded to mate with the threads of the apertures of the coupling member  303 . Finally, the second-end portions  315  of the hook members  306  are removably attached to the linkage assembly  115  as described above. 
   INDUSTRIAL APPLICABILITY 
   The restraints  145  and the collars  160  lock the linkage assembly  115 , including the lift arm  126  and the tilt linkage assembly  125 , in a predetermined position preventing it from traveling from that position. In other words, the restraints  145  restrain the linkage assembly  115 , and in particular, the lift arm  126 , from any substantial up and down travel and restrains the tilt linkage assembly  125  from any tilting function. The restraints  145  are removably attached to the work machine by attaching the second-end portions  151  of the restraints  145  to the chassis  100 , or more particularly, to that portion of the chassis  100  that comprises the axle  106 , by using the brackets  153  and bolts  154 ,  155  and then attaching the first-end portions  148  of the restraints  145  to the linkage assembly  115  by having the hooks  255  fit over the linkage assembly  115  and having the bolts  256  threaded through the apertures  257  in the hooks  255 . Finally, the collars  160  are removably attached to the hydraulic cylinders  133 ,  136  by placing the collars  160  on the rod ends  139  of the hydraulic cylinders  133 ,  136  abutting against the cylinder ends  142  and attaching them thereto. The collars  160  prevent the hydraulic cylinders  133 ,  136  from floating, or more particularly, the collars  160  prevent the hydraulic cylinders  133 ,  136  from compressing the rod ends  139  thereof toward the cylinder ends  142 . This prevents the linkage assembly  115 , and more particular, the lift arm  126 , from substantial travel, or more specifically, lowering, especially when a load is placed thereon. Additionally, because the restraints  145  are removably attached to that portion of the linkage assembly  115  that comprises the tilt linkage assembly  125 , the restraints  145  prevent substantial travel of the tilt linkage assembly  124 , or more particularly, the tilt function. 
   To remove the restraints  145 , the bolts  256  are unthreaded and removed from the apertures  257  in the hooks  255  of the first-end portions  148 . The bolts  154  and  155  are unthreaded and removed from the bracket  153 . The hooks  255  are then lifted off of the linkage assembly  115  and the restraints  145  are removed. 
   In the alternate embodiment, the restraints  145  are removably attached to the work machine as described above. Except however, the coupling members  303  and the hook members  306  are removably attached to one another by the use of bolts  322  being inserted into the apertures  320  and being threaded into the threaded apertures of the coupling member  303 . To remove the restraints  145  of this embodiment, the bolts  256  are unthreaded and removed from the apertures  257  in the second-end portions  315  of the hook members  306 . Then the bolts  322  are unthreaded from the apertures of the coupling members  303  and the apertures  320  of the hook members  306 . The hook members  306  are lifted off the linkage assembly  115  and are removed therefrom. The coupling members  303  remain out of the way of the operation of the work machine and, therefore, can remain attached to the axle  106 . The coupling members  303  can then even be used to lock the work machine in place during transportation thereof. To reattach the restraints  145  in this embodiment, only the hook members  306  need be attached to the coupling members  303  and the linkage assembly  115 , as previously described. 
   It should be understood that the removable attachment of the first-end portions  148  and the second-end portions  151  of the restraints  145  and removable attachment of the collars  160  does not need to occur in any specific order. In addition, the attachment of the coupling members  303  and the hook members  306  may occur in any order. Once the linkage assembly  115  is in the predetermined position and the restraints  145  and collars  160  are attached, any loads placed on the linkage assembly  115 , including the lift arm  126  and the tilt linkage assembly  125 , during operation of the work machine are transferred through the restraints  145  to the chassis  100  of the work machine, or more particularly, through the restraints  145  to the axles  106  of the work machine. The restraints  145  help prevent shock loads from being placed on the linkage assembly  115 , including the cylinders  127 ,  130 ,  133 ,  136 , the lift arm  126 , and the tilt linkage assembly  125 . This may help prevent damage to those components of the work machine. For example, if a very heavy implement  124  is attached to the linkage assembly  115 , it may be appropriate to restrain the linkage assembly  115  to prevent damage to the linkage assembly  115 , including the cylinders  127 ,  130 ,  133 ,  136 , the lift arm  126 , and the tilt linkage assembly  125 , and to prevent the work machine from tipping. Additionally, the restraints  145  may be used to restrain the linkage assembly  115  for other purposes, such as convenience, efficient operation of the work machine or the implement  124 , to keep the implement  124  in a particular position, etc. 
   Other aspects, objects and advantages of the invention can be obtained from a study of the drawings, the disclosure and the appended claims.