Booster recoil mechanism for endless track machine

A recoil mechanism for an endless track of a material working machine having a frame and a moveable track engaging wheel, comprising:

• a connecting member attachable to the track engaging wheel;
• a hydraulic cylinder having first and second end portions, said first end portion being connectable to the machine frame;
• a longitudinally extending recoil frame having first and second end portions and a middle, portion, said first end portion being connectable to the second end portion of the hydraulic cylinder and the second end portion being attachable to the connecting member, said first and second end portions having threads formed thereon and said middle portion having a flange connected thereto;
• a first spring having a first compression rate and being positioned about the first end portion of the recoil frame;
• a second spring having a second compression rate different from the compression rate of the first spring, said second spring being positioned about the second end portion of the recoil frame;
• a first moveable spring stop assembly positioned at the middle portion of the recoil frame at a location between said middle portion flange and said first spring;
• a second moveable spring stop assembly positioned at the first end portion of the recoil frame at a location between the hydraulic cylinder the first spring and in contact with said first spring;
• a third moveable spring stop assembly positioned on the second end portion of the recoil frame at a location between the connecting member and the second spring and in contact with said second spring;
• a first housing extending about and covering the first spring and being connected to the first spring stop assembly;
• and
• a second housing extending about and covering the second spring, being connected to the third spring stop assembly, and moveable into contact with the first spring stop assembly.