Lift Arms and Linkage Arrangement for Scoop Assembly

Abstract

A scoop assembly is disclosed for a wheel dozer. The scoop assembly includes a frame that includes right and left lift arms that may be coupled together by a distal cross beam. The lift arms include proximal portions that extend between the two cross beams and a distal hook-shaped portion that extends forward beyond the distal cross beam. The distal hook-shaped portions pivotally connect to the bucket. The distal cross beam provides a place for the location of a bracket that supports a single dump cylinder that extends upward into a central pocket disposed in the back of the bucket. The dump cylinder is protected from debris due to its raised position and placement inside a centralized pocket that does not experiment the flow of debris materials.

What is claimed is: 
     
         1 . A scoop assembly comprising:
 right and left lift arms, each lift arm including a proximal end, a proximal portion, a distal portion and a distal end, each proximal portion disposed between its respective proximal end and its respective hook shaped distal portion, each hook shaped distal portion disposed between its respective proximal portion and its respective distal end, the right and left lift arms being coupled together by a distal cross beam;   a bucket including right and left sidewalls and a curved wall disposed therebetween, the distal ends of right and left lift arms being pivotally coupled to the right and left sidewalls respectively, the bucket further including a center pocket with a rear opening;   the distal cross beam being coupled to one end of a dump cylinder having another end that is received in and pivotally connected to the central pocket of the bucket.   
     
     
         2 . The scoop assembly of  claim 1  wherein the right sidewall includes a right pocket with a rear opening for receiving the distal end and at least part of the distal portion of the right lift arm, the left sidewall including a left pocket with a rear opening for receiving the distal end and at least part of the distal portion of the left lift arm. 
     
     
         3 . The scoop assembly of  claim 1  wherein the dump cylinder is disposed substantially in the central pocket throughout a range of motion provided by contracting and extending the dump cylinder. 
     
     
         4 . The scoop assembly of  claim 1  wherein the distal ends of the right and left lift arms are connected to the right and left sidewalls along a first axis that passes through the distal ends of the right and left lift arms,
 the dump cylinder being connected to the central pocket of the bucket at a first point that is disposed vertically above the first axis throughout a range of motion of the bucket provided by the dump cylinder. 
 
     
     
         5 . The scoop assembly of  claim 1  wherein dump cylinder is connected to the central pocket at a first point that is disposed above a center of gravity of the bucket throughout a range of motion provided by contracting and extending the dump cylinder. 
     
     
         6 . The scoop assembly of  claim 1  wherein the distal ends of the right and left lift arms have a first axis passing therethrough, and
 a center of gravity of the bucket is disposed below the first axis throughout a range of motion provided by contracting and extending the dump cylinder. 
 
     
     
         7 . The scoop assembly of  claim 1  wherein the distal cross beam includes a bracket for connection to a blade. 
     
     
         8 . The scoop assembly of  claim 1  further including right and left tilt cylinders, right and left tilt levers and right and left cylinder brackets;
 the right tilt lever being pivotally coupled to the proximal end of the right lift arm, the left tilt lever being pivotally coupled to the proximal end of the left lift arm, the right cylinder bracket being coupled to the right lift arm between the proximal and distal ends thereof, the left cylinder bracket being coupled to the left lift arm between the proximal and distal ends thereof. 
 
     
     
         9 . The scoop assembly of  claim 8  wherein the right and left cylinder brackets are disposed on the proximal portions of the right and left lift arms respectively. 
     
     
         10 . The scoop assembly of  claim 1  further including a proximal cross beam having right and left ends that are pivotally coupled to the proximal ends of the right and left lift arms respectively. 
     
     
         11 . The scoop assembly of  claim 8  further including a proximal cross beam having right and left ends that are pivotally coupled to the right and left tilt levers respectively. 
     
     
         12 . The scoop assembly of  claim 11  wherein the right and left tilt levers are coupled to right and left spherical bearings, the right and left ends of the proximal cross being received in the right and left spherical bearings respectively. 
     
     
         13 . The scoop assembly of  claim 12  wherein the right and left ends of the proximal cross beam are right and left trunnions respectively. 
     
     
         14 . The scoop assembly of  claim 13  wherein the right and left spherical bearings provide translational freedom along the common axis for maintaining the right and left trunnions within the right and left spherical bearings respectively when the proximal ends of the right and left lift arms are tilted. 
     
     
         15 . The scoop assembly of  claim 14  wherein the right and left spherical bearings each include a housing and a bearing insert for receiving one of the trunnions, each housing providing a lateral translational degree of freedom for its respective bearing insert to move within its respective housing when the proximal ends of the right and left lift arms are tilted. 
     
     
         16 . A scoop assembly comprising:
 right and left lift arms, each lift arm including a proximal end, a proximal portion, a distal portion and a distal end, each proximal portion disposed between respective its proximal end and respective its hook shaped distal portion, each hook shaped distal portion disposed between its respective proximal portion and its respective distal end, the right and left lift arms being further coupled together by a distal cross beam;   a bucket comprising right and left sidewalls and a curved wall disposed therebetween, the right sidewall includes a right pocket with a rear opening for receiving the distal end and at least part of the distal portion of the right lift arm, the left sidewall including a left pocket with a rear opening for receiving the distal end and at least part of the distal portion of the left lift arm, the distal ends of right and left lift arms being pivotally coupled to the right and left sidewalls respectively while being disposed inside the right and left pockets respectively;   the bucket further including a center pocket with a rear opening, the distal cross beam being coupled to one end of a dump cylinder having another end that is received in and pivotally connected to the central pocket of the bucket.   
     
     
         17 . The scoop assembly of  claim 16  wherein the dump cylinder is disposed substantially in the central pocket in throughout a range of motion provided by contracting and extending the dump cylinder. 
     
     
         18 . The scoop assembly of  claim 16  wherein the distal ends of the right and left lift arms connected to the right and left sidewalls along a first axis passing through the distal ends of the right and left lift arms,
 the end of the dump cylinder that is connected to the central pocket of the bucket is connected to the bucket at a first point that is disposed vertically above the first axis throughout a range of motion of the bucket provided by the dump cylinder. 
 
     
     
         19 . The scoop assembly of  claim 16  wherein the distal ends of the right and left lift arms have a first axis passing therethrough, and
 a center of gravity of the bucket is disposed below the first axis throughout a range of motion provided by contracting and extending the dump cylinder. 
 
     
     
         20 . A scoop assembly comprising:
 right and left lift arms, each lift arm including a proximal end, a proximal portion, a distal end, and a distal portion, each proximal portion disposed between its respective proximal end and its respective distal portion, each distal portion disposed between its respective proximal portion and its respective distal end;   a bucket comprising right and left sidewalls and a curved wall disposed therebetween, the right sidewall includes a right pocket with a rear opening for receiving the distal end and at least part of the distal portion of the right lift arm, the left sidewall including a left pocket with a rear opening for receiving the distal end and at least part of the distal portion of the left lift arm, the distal ends of right and left lift arms being pivotally coupled to the right and left sidewalls respectively while being disposed inside the right and left pockets respectively;   the bucket further including a center pocket with a rear opening, the distal cross beam being coupled to one end of a dump cylinder having another end that is received in and pivotally connected to the central pocket of the bucket;   right and left tilt cylinders, right and left tilt levers, and right and left cylinder brackets, the right tilt lever being pivotally coupled to the proximal end of the right lift arm, the left tilt lever being pivotally coupled to the proximal end of the left lift arm, the right cylinder bracket being coupled to the right lift arm between the proximal and distal ends thereof, the left cylinder bracket being coupled to the left lift arm between the proximal and distal ends thereof, a proximal cross beam extending between and being pivotally and slidably coupled to the right and left tilt levers;   wherein retraction of the right tilt cylinder in combination with extension of the left tilt cylinder causing the right and left lift arms and the bucket to tilt to the right while the proximal cross beam remains stationary and coupled to the right and left tilt levers and wherein extension of the right tilt cylinder in combination with retraction of the left tilt cylinder causing the right and left lift arms and the bucket to tilt to the left while the proximal cross beam remains stationary and coupled to the right and left tilt levers.