Patent ID: 6880317
Filing Date: 2005-04-19
Classification: A01B,Y10T

Abstract:
1. A hydraulic system, comprising: a frame member having an end; a structural member pivotally coupled with said frame member end; a first hydraulic cylinder including a cylinder housing, a ram with a head reciprocally disposed within said housing, a first chamber on one side of said head, a second chamber on an other side of said head, a first end associated with one of said cylinder housing and said ram, a second end associated with an other of said cylinder housing and said ram, said first end of said first hydraulic cylinder being attached to said frame member; a preload spring having a first end and a second end, said spring first end being attached to said frame member, said spring second end being attached to one of said structural member and said second end of said first hydraulic cylinder; a second hydraulic cylinder coupled between said frame member and said structural member, said second hydraulic cylinder including a cylinder housing, a ram with a head reciprocally disposed within said housing, a first chamber on one side of said head, and a second chamber on an other side of said head; a first fluid line interconnecting said first chamber of said first hydraulic cylinder and said first chamber of said second hydraulic cylinder; a second fluid line interconnecting said second chamber of said first hydraulic cylinder and said second chamber of said second hydraulic cylinder; and a valve interposed in one of said first fluid line and said second fluid line.