Gang-type lawn mower

Abstract

A mower includes a frame, at least one cutting unit, and a lifting unit. The lifting unit is connected to the at least one cutting unit and includes a yoke assembly, a first arm assembly, a second arm assembly, and a third arm assembly. The yoke assembly is connected to the cutting unit. The first arm assembly is pivotably mounted to the vehicle frame about a first pivot axis. The second arm assembly is pivotably mounted to the first arm assembly about a second pivot axis and to the yoke assembly about a third pivot axis with the second pivot axis and third pivot axis being non-parallel to the first pivot axis. The third arm assembly includes a first end pivotally connected to the frame and a second end pivotally connected to the second arm assembly.

1 . A mower comprising:
 a frame supported by a plurality of wheels, wherein at least one of the wheels is driven to propel the frame over the ground;   at least one cutting unit; and   a lifting unit connecting to the at least one cutting unit, the lifting unit comprising
 a yoke assembly connected to one of the cutting units; 
 a first arm assembly pivotably mounted to the vehicle frame about a first pivot axis; 
 a second arm assembly pivotably mounted to the first arm assembly about a second pivot axis and to the yoke assembly about a third pivot axis with the second pivot axis and third pivot axis being non-parallel to the first pivot axis; and 
 a third arm assembly having a first end pivotally connected to the frame and a second end pivotally connected to the second arm assembly. 
   
     
     
         2 . The mower of  claim 1 , wherein the cutting unit lift moves the at least one cutting unit between a first, lowered position and a second, raised position. 
     
     
         3 . The mower of  claim 2 , wherein the second arm assembly includes a first arm and a second arm, wherein each of the first arm and the second arm include a first end pivotally connected to the first arm assembly and a second end pivotally connected to the yoke assembly. 
     
     
         4 . The mower of  claim 3 , wherein the first arm and the second arm remain parallel to one another in both the lowered position and the upright position. 
     
     
         5 . The mower of  claim 3 , wherein the first end of the third arm assembly is pivotally coupled to the frame forward of the second arm assembly. 
     
     
         6 . The mower of  claim 5 , wherein the second end of the third arm assembly is pivotally connected to the second arm of the second arm assembly, wherein the second arm of the second arm assembly is located to the rear of the first arm of the second arm assembly. 
     
     
         7 . The mower of  claim 2 , further including a hydraulic cylinder connected between the frame and a first end of the first arm assembly, wherein the hydraulic cylinder is actuated to raise the cutting unit from the first position to the second position. 
     
     
         8 . The mower of  claim 1 , wherein the second pivot axis and third pivot are approximately perpendicular to the first pivot axis. 
     
     
         9 . The mower of  claim 1 , wherein the first end of the third arm assembly is pivotally connected to the frame forward of the second arm assembly. 
     
     
         10 . The mower of  claim 1 , further including an operator seat, wherein a forward cutting edge of the cutting unit is located approximately equal to the operator seat along a longitudinal axis when in a first, lowered position and wherein the forward edge of the cutting unit is located rearward of the operator seat when in a second, raised position. 
     
     
         11 . The mower of  claim 10 , further including roll over protection bar located rearward of the operator seat, wherein the forward cutting edge of the cutting unit is located forward of the roll over protection bar when in the first, lowered position and wherein the forward edge of the cutting unit is located rearward of the roll over protection bar when in the second, raised position. 
     
     
         12 . A lifting unit comprising
 a yoke assembly;   a first arm assembly having a first end and a second end, wherein the first arm assembly includes apertures configured to pivotally affix the first arm assembly to a stationary frame about a first pivot axis;   a second arm assembly having a first end and a second end, wherein the first end is pivotably connected to the second end of the first arm assembly about a second pivot axis and wherein the second end is pivotally connected to the yoke assembly about a third pivot axis, wherein the second pivot axis and third pivot axis are non-parallel to the first pivot axis; and   a third arm assembly having a first end configured to pivotally connect the third arm assembly to the stationary frame and a second end pivotally connected to the second arm assembly.   
     
     
         13 . The lifting unit of  claim 12 , wherein the lifting unit moves the yoke assembly between a first, lower position and a second, raised position. 
     
     
         14 . The lifting unit of  claim 13 , wherein the second arm assembly includes a first arm and a second arm, wherein each of the first arm and the second arm include a first end pivotally connected to the first arm assembly and a second end pivotally connected to the yoke assembly. 
     
     
         15 . The lifting unit of  claim 14 , wherein the first arm and the second arm remain parallel to one another in both the lowered position and the upright position. 
     
     
         16 . The lifting unit of  claim 14 , wherein the first end of the third arm assembly is configured to connect to the stationary frame forward of the second arm assembly. 
     
     
         17 . The lifting unit of  claim 16 , wherein the second end of the third arm assembly is pivotally connected to the second arm of the second arm assembly, wherein the second arm of the second arm assembly is located to the rear of the first arm of the second arm assembly. 
     
     
         18 . The lifting unit of  claim 12 , wherein the second pivot axis and third pivot are approximately perpendicular to the first pivot axis. 
     
     
         19 . The lifting unit of  claim 12 , wherein the first end of the third arm assembly is configured for connection to the stationary frame forward of the second arm assembly