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.

What is claimed is: 
     
         1 . A lifting unit operatively connecting a cutting unit to the chassis of a turf mower, the lifting unit comprising:
 a lifting frame assembly connected to mower chassis;   a first arm assembly pivotably mounted to the lifting frame assembly about a first pivot axis;   a second arm assembly pivotably mounted to the first arm assembly about a second pivot axis;   a third arm assembly having a first end pivotally connected to the lifting frame assembly and a second end pivotally connected to the second arm assembly; and   a yoke assembly pivotally connected to the second arm assembly about a third pivot axis and pivotally connected to the cutting unit,   
       wherein the lifting unit is structured and operable to move the cutting unit between a lowered position and raised position, and wherein the second pivot axis and third pivot axis being non-parallel to the first pivot axis. 
     
     
         2 . The lifting unit of  claim 1 , 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. 
     
     
         3 . The lifting unit of  claim 2 , wherein the first arm and the second arm remain parallel to one another in both the lowered position and the raised position. 
     
     
         4 . The lifting unit of  claim 2 , wherein the first end of the third arm assembly is pivotally coupled to the lifting frame assembly forward of where the second arm assembly pivotably mounts to the first arm assembly. 
     
     
         5 . The lifting unit of  claim 4 , wherein the second end of the third arm assembly is pivotally connected to the second arm of the second arm assembly, and wherein the second arm of the second arm assembly is located rearward of the first arm of the second arm assembly. 
     
     
         6 . The lifting unit of  claim 1  further comprising a hydraulic cylinder connected between the lifting frame assembly and a first end of the first arm assembly, wherein the hydraulic cylinder is actuated to raise the cutting unit from the lowered position to the raised position. 
     
     
         7 . The lifting unit of  claim 1 , wherein the second pivot axis and the third pivot are approximately perpendicular to the first pivot axis when the cutting unit is in both the lowered and raised position. 
     
     
         8 . The lifting unit of  claim 1  wherein the first end of the third arm assembly is secured to the lifting frame assembly at a location offset from where the first end of the second arm is pivotally mounted to the first arm assembly in one of a longitudinally forward or rearward direction. 
     
     
         9 . A turf mower, said mower comprising:
 a chassis supported by a plurality of ground engagement members;   a cutting unit; and   a lifting unit operatively connecting the cutting unit to the chassis, the lifting unit comprising:
 a lifting frame assembly connected to mower chassis; 
 a first arm assembly pivotably mounted to the lifting frame assembly about a first pivot axis; 
 a second arm assembly pivotably mounted to the first arm assembly about a second pivot axis; 
 a third arm assembly having a first end pivotally connected to the lifting frame assembly and a second end pivotally connected to the second arm assembly; and 
 a yoke assembly pivotally connected to the second arm assembly about a third pivot axis and pivotally connected to the cutting unit, 
   wherein the lifting unit is structured and operable to move the cutting unit between a lowered position and raised position, and wherein the second pivot axis and third pivot axis being non-parallel to the first pivot axis.   
     
     
         10 . The mower of  claim 9 , 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. 
     
     
         11 . The mower of  claim 10 , wherein the first arm and the second arm remain parallel to one another in both the lowered position and the raised position. 
     
     
         12 . The mower of  claim 10 , wherein the first end of the third arm assembly is pivotally coupled to the lifting frame assembly forward of where the second arm assembly pivotably mounts to the first arm assembly. 
     
     
         13 . The mower of  claim 12 , 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 rearward of the first arm of the second arm assembly. 
     
     
         14 . The mower of  claim 9  further comprising a hydraulic cylinder connected between the lifting frame assembly and a first end of the first arm assembly, wherein the hydraulic cylinder is actuated to raise the cutting unit from the lowered position to the raised position. 
     
     
         15 . The mower of  claim 9 , wherein the second pivot axis and the third pivot are approximately perpendicular to the first pivot axis when the cutting unit is in both the lowered and raised position. 
     
     
         16 . The mower of  claim 9  further comprising a roll over protection bar located rearward of the operator seat, wherein a forward cutting edge of the cutting unit is located forward of the roll over protection bar when in the lowered position and wherein the forward edge of the cutting unit is located rearward of the roll over protection bar when in the raised position. 
     
     
         17 . The mower of  claim 9  wherein the first end of the third arm assembly is secured to the lifting frame assembly at a location offset from where the first end of the second arm is pivotally mounted to the first arm assembly in one of a longitudinally forward or rearward direction. 
     
     
         18 . A lifting unit operatively connecting a cutting unit to the chassis of a turf mower, the lifting unit comprising:
 a lifting frame assembly connected to mower chassis;   a first arm assembly pivotably mounted to the lifting frame assembly about a first pivot axis;   a second arm assembly pivotably mounted to the first arm assembly about a second pivot axis;   a third arm assembly having a first end pivotally connected to the lifting frame assembly and a second end pivotally connected to the second arm assembly; and   a yoke assembly pivotally connected to the second arm assembly about a third pivot axis and pivotally connected to the cutting unit,   
       wherein the lifting unit is structured and operable to move the cutting unit between a lowered position and raised position, and wherein the second pivot axis and third pivot axis being non-parallel to the first pivot axis, and wherein the second pivot axis and the third pivot are approximately perpendicular to the first pivot axis when the cutting unit is in both the lowered and raised position. 
     
     
         19 . The lifting unit of  claim 18  wherein when the cutting unit is in the lowered position a forward edge of the cutting unit is located forward of a roll over protection bar of the turf mower when in the raised position the forward edge of the cutting unit is located rearward of the roll over protection bar. 
     
     
         20 . The lifting unit of  claim 1  wherein the first end of the third arm assembly is secured to the lifting frame assembly at a location offset from where the first end of the second arm is pivotally mounted to the first arm assembly in one of a longitudinally forward or rearward direction.