Linkage arrangement for a skid-steer loader

An off-highway loading vehicle having a frame, a cab, front and rear tires, and a linkage arrangement for operably attaching a work implement to the frame, comprising:

• a pair of spaced apart lift arms having a rear end portion pivotally connected to the frame rearwardly of the cab and a forward end portion pivotally connected to the work implement, a lowermost edge of a forward section of the lift arms angling downwardly from a lowermost edge of a rearward section thereof, whereby the lift arms avoid contact with the frame when in a lowered position to place the work implement adjacent a front end of the frame;
• a pair of lift cylinders pivotally attached to the frame and the lift arms to move the lift arms between said lowered position and a raised position;
• and
• a tilt mechanism to pivot the work implement between a lowered position in which an underside thereof is tilted below a horizontal plane, an intermediate position in which said underside is substantially horizontal, and a raised position in which said underside is tilted above the horizontal plane, said tilt mechanism including a pair of tilt linkages pivotally connected to said work implement, a pair of extension arms interconnecting the lift arms and the tilt linkages, the extension arms being pivotally connected to the rearward sections of the lift arms, and a pair of tilt cylinders having forward ends pivotally connected between the lift arms and said tilt linkages to thereby tilt the work implement a desired amount.

An off-highway loading vehicle having a frame, a forward cab, front and rear tires, and a linkage arrangement for operably attaching a work implement to the frame, comprising:

• a pair of spaced apart lift arms having a rear end portion pivotally connected to the frame rearwardly of the cab at a level generally as high as a top portion of the cab, and a forward end portion pivotally connected to the work implement, a lowermost edge of a forward section of the lift arms angling downwardly from a lowermost edge of a rearward section thereof, whereby the lift arms avoid contact with the frame when in a lowered position to place the work implement adjacent a front end of the frame;
• a horizontal cross-bar interconnecting the lift arms, said cross-bar being positioned generally adjacent the juncture of said forward section and rearward section of said lift arms, whereby the cross-bar is positioned to avoid contact with the frame when the lift arms are in a lowered position to place the work implement adjacent a front end of the frame;
• a pair of lift cylinders pivotally attached to the frame and the lift arms to move the lift arms between said lowered position and a raised position;
• a self-leveling mechanism adapted to maintain the work implement in a generally constant angular position, said self-leveling mechanism including a pair of levers pivotally attached to rear portions of said lift arms, and a pair of leveling linkages pivotally attached to the frame and lower ends of the levers;
• and
• a tilt mechanism to pivot the work implement between a lowered position in which an underside thereof is tilted below a horizontal plane, an intermediate position in which said underside is substantially horizontal, and a raised position in which said underside is tilted above the horizontal plane, said tilt mechanism including a pair of tilt linkages pivotally connected to said work implement, a pair of extension arms pivotally interconnecting the lift arms and said tilt linkages, and a pair of tilt cylinders having forward ends pivotally connected to said tilt linkages and rearward ends pivotally connected to upper ends of the levers, said tilt linkages being aligned in respective generally vertical planes with the corresponding lift arms, and each tilt linkage having an offset portion displaced from said respective vertical plane to avoid interference with said corresponding lift arm when the work implement is retracted by the tilt mechanism to the raised position with the lift arms in the lowered position.

An apparatus for maintaining a fluid conduit generally taut during operation of a linkage arrangement adapted to operably raise and tilt a work implement relative to a frame of an off-highway loading vehicle, the apparatus in combination with the fluid conduit and linkage arrangement comprising:

• a lift arm having a rear end portion pivotally connectable to the frame and a forward end portion pivotally connectable to the work implement;
• a lifting device operatively connectable between the frame and the lift arm to move the lift arm between a lowered position and a raised position;
• a tilt mechanism including a tilt cylinder assembly supported on the lift arm and operatively connectable to tilt the work implement, said tilt cylinder assembly being pivotable about a moveable pivot point and having the fluid conduit attached thereto;
• a self-leveling mechanism operatively connected to the lift arm and supporting the pivot point of the tilt cylinder assembly so as to move said pivot point in response to movement of the lift arm, thereby maintaining the work implement in a generally constant angular position as said work implement is moved by the lift arm;
• and
• a conduit control device provided on the tilt mechanism to hold the fluid conduit in a loop orientation so as to retain the fluid conduit generally taut throughout the range of movement of the tilt cylinder assembly pivot point.

A loading mechanism for an off-highway loading vehicle having a frame, a cab, front and rear tires, and a linkage arrangement for operably attaching a work implement to the frame, comprising:

• a pair of spaced apart lift arms having a rear end portion pivotally connectable to the frame and a forward end portion pivotally connectable to the work implement;
• a lifting device operatively connectable between the frame and the lift arms to move the lift arms between a lowered position and a raised position;
• a tilt mechanism including a tilt cylinder assembly supported on each lift arm and operatively connectable to tilt the work implement, each tilt cylinder assembly being pivotable about a moveable pivot point and having a fluid conduit attached thereto;
• a self-leveling mechanism operatively connected to each tilt mechanism so as to move the corresponding pivot points in response to movement of the lift arms, thereby maintaining the work implement in a generally constant angular position as said work implement is moved by the lift arms;
• and
• a conduit control device provided on each tilt cylinder assembly to retain the respective fluid conduit generally taut throughout the range of movement of the tilt cylinder assembly pivot points, each control device including an attachment member to secure the respective fluid conduit in a loop orientation to a rear end portion of the corresponding tilt cylinder assembly, and a guide member proximate the rear end portion of the corresponding tilt cylinder assembly to guide the fluid conduit, said fluid conduits progressively engaging the respective guide members as the length of fluid conduits increase during movement of the lift arms.