Cabless loader lift arm

Abstract

A lift arm has a longitudinal lift arm center line that is in a common plane with a longitudinal power machine center line. The lift arm is configured to rotate about a pivot axis that is perpendicular to the plane. The power machine includes a frame having an undercarriage and an upper portion, the undercarriage having opposed sides and the upper portion having a first width. The lift arm includes first and second cross members and a first elongated member. The first cross member spans the first width and is configured for attachment to the power machine at first and second joints. A first end of the first elongated member is attached to the first cross member inward of the opposed sides of the undercarriage. The second cross member is attached to the second end of the first elongated member and is configured for attachment to an implement.

What is claimed is: 
     
         1 . A lift arm configured for attachment to a power machine at first and second joints, wherein a longitudinal lift arm center line is in a common plane with a longitudinal power machine center line, and wherein the lift arm is configured to rotate about a pivot axis of the first and second joints that is perpendicular to the plane, wherein the power machine includes a frame having an undercarriage and an upper portion, the undercarriage having two chain case housings with respective inner walls and the upper portion having a first width perpendicular to the center line, the lift arm comprising:
 a first cross member spanning the first width and configured for attachment to the frame at the first and second joints;   a first elongated member having a first end and an opposed second end, wherein the first end of the first elongated member is attached to the first cross member inward of a respective inner wall of a respective chain case housing; and   a second cross member attached to the second end of the first elongated member, wherein the second cross member is configured for attachment to an implement.   
     
     
         2 . The lift arm of  claim 1  comprising a second elongated member is that parallel to the first elongated member. 
     
     
         3 . The lift arm of  claim 1 , wherein the first cross member comprises a third joint positioned on the lift arm center line and configured for attachment to a first actuator. 
     
     
         4 . The lift arm of  claim 3 , wherein the first cross member comprises first and second lateral branches extending outwardly away from the third joint, wherein:
 the first lateral branch terminates proximate the first joint; and   the second lateral branch terminates proximate the second joint.   
     
     
         5 . The lift arm of  claim 3 , wherein the second cross member comprises a fourth joint positioned on the lift arm center line and configured for attachment to a second actuator. 
     
     
         6 . The lift arm of  claim 5 , wherein the second cross member comprises first and second lateral branches extending outwardly away from the fourth joint, and wherein each of the first and second lateral branches terminates proximate an implement joint. 
     
     
         7 . The lift arm of  claim 6  comprising a third cross member that spans between the first and second lateral branches proximate the implement joints. 
     
     
         8 . The lift arm of  claim 1 , wherein the first cross member, the first elongated member, and the second cross member are mutually positionally fixed. 
     
     
         9 . A power machine having a longitudinal center line and comprising:
 a frame having a front end and a rear end, a first width between opposed left and right sides of an upper frame portion, and a second width between opposed left and right sides of an undercarriage;   a lift arm having a front end and a rear end, wherein the rear end of the lift arm is attached to the frame proximate the left and right sides;   a front axle attached to the frame and configured for mounting a first tractive element;   a rear axle attached to the frame and configured for mounting a second tractive element; and   a first actuator attached to the lift arm at a first joint and attached to the frame at a second joint, wherein the second joint is positioned forward of the front axle.   
     
     
         10 . The power machine of  claim 9 , wherein the lift arm comprises:
 a first cross member spanning the first width;   a first elongated member having opposed first and second ends, wherein the first end is attached to the first cross member inward of the left and right sides of the undercarriage; and   a second cross member attached to the second end of the first elongated member and spanning the second width.   
     
     
         11 . The power machine of  claim 10 , wherein the first joint of the first actuator is positioned along the longitudinal center line of the power machine. 
     
     
         12 . The power machine of  claim 11 , wherein the first elongated member is one of two parallel elongated members that are equally spaced from the longitudinal center line on opposed sides of the first joint. 
     
     
         13 . The power machine of  claim 9  comprising a second actuator attached to the lift arm at a third joint and configured for attachment to an implement at a fourth joint. 
     
     
         14 . The power machine of  claim 13  comprising the implement, wherein the implement is configured as a bucket. 
     
     
         15 . The power machine of  claim 9 , wherein the lift arm is attached to the frame rearward of the rear axle. 
     
     
         16 . A lift arm having a first end and a second end and configured for attachment to a power machine, the lift arm comprising:
 a first cross member comprising:
 a first cross brace; 
 a first left lateral branch extending from a left side of the first cross brace and terminating at a left rear joint at the first end; 
 a first right lateral branch extending from a right side of the first cross brace and terminating at a right rear joint at the first end; 
   a first elongated member attached to the first cross member at a juncture of the first cross brace and the first left lateral branch;   a second elongated member attached to the first cross member at a juncture of the first cross brace and the first right lateral branch, wherein the second elongated member is parallel to the first elongated member; and   a second cross member comprising:
 a second cross brace; 
 a second left lateral branch extending from a left side of the second cross brace and terminating at a left front joint at the second end; and 
 a second right lateral branch extending from a right side of the second cross brace and terminating at a right front joint at the second end. 
   
     
     
         17 . The lift arm of  claim 16  comprising a third cross member that spans between the second left and right lateral branches proximate the left and right front joints. 
     
     
         18 . The lift arm of  claim 16 , wherein each of the first and second elongated members is configured as a tube. 
     
     
         19 . The lift arm of  claim 16 , wherein each of the first left and right lateral branches comprises an inner angled wall and an outer angled wall joined by top and bottom walls. 
     
     
         20 . The lift arm of  claim 16 , wherein at least one of the first and second cross braces comprises two side plates joined by a bushing brace.