Arm assembly

1. An arm assembly for a working vehicle, the arm assembly comprising a material handling implement, a boom, a dipper arm, a first hydraulic ram, and a second hydraulic ram;

the dipper arm having a unitary single plate, a first end, and a second end, the single plate being centrally located when the dipper arm is viewed in cross-section, the single plate having a first end corresponding to the first end of the dipper arm and a second end corresponding to the second end of the dipper arm;

a first portion of the dipper arm disposed between the first and second ends of the dipper arm is pivotally attached to the boom by a first pivot, and a second portion of the dipper arm disposed at the second end of the dipper arm is pivotally attached to the material handling implement by a second pivot;

the first hydraulic ram being operable to pivot the dipper arm relative to the boom, the first hydraulic ram including a first end attached to the boom and a second end having a first clevis, the first clevis being attached to a first clevis eye carried at least by the spine of the single plate at the first end of the dipper arm; and

the second hydraulic ram being operable to pivot the material handling implement relative to the dipper arm, the second hydraulic ram including a ram end having a second clevis, the second clevis being attached to a second clevis eye carried only by the spine of the single plate between the first and second ends of the dipper arm.

2. The arm assembly according to claim 1 , wherein the single plate includes at least one cut out.

3. The arm assembly according to claim 2 , wherein the at least one cut out is formed in a central portion of the single plate.

4. The arm assembly according to claim 1 , wherein the single plate further includes a connector for connection to an attachment.

5. The arm assembly according to claim 4 , wherein the connector is arranged for direct connection to the attachment.

6. The arm assembly according to claim 1 , wherein the single plate is constructed as a laminate and includes a first plate layer and at least one further plate layer, the first plate layer and the at least one further plate layer being arranged to form the single plate as a unitary structure.

7. A working vehicle including ground engaging means, an operator's cab and an arm assembly according to claim 1 .

8. An arm assembly for a working vehicle, the arm assembly comprising a material handling implement, a boom, a dipper arm, a first hydraulic ram, and a second hydraulic ram;

the dipper arm having a unitary single plate, a first end, and a second end, the single plate being centrally located when the dipper arm is viewed in cross-section, the single plate having a first end corresponding to the first end of the dipper arm and a second end corresponding to the second end of the dipper arm, the single plate further having an upper surface, a lower surface, an inner face, and an outer face, with the single plate forming a central spine of the dipper arm bounded by the upper and lower surfaces and the inner and outer faces of the single plate;

a first portion of the dipper arm disposed between the first and second ends of the dipper arm is pivotally attached to the boom by a first pivot boss, and a second portion of the dipper arm disposed at the second end of the dipper arm is pivotally attached to the material handling implement by a second pivot boss;

the first hydraulic ram being operable to pivot the dipper arm relative to the boom, the first hydraulic ram including a first end attached to the boom and a second end having a first clevis, the first clevis being attached to a first clevis eye carried at least by the spine of the single plate at the first end of the dipper arm; and

the second hydraulic ram being operable to pivot the material handling implement relative to the dipper arm, the second hydraulic ram including a ram end having a second clevis, the second clevis being attached to a second clevis eye carried only by the spine of the single plate between the first and second ends of the dipper arm; and

further including an outer torsion member secured to the outer surface of the single plate and an inner torsion member secured to the inner surface of the single plate, the inner and outer torsion members being mounted adjacent to the lower surface of the single plate and spaced away from upper surface and the first clevis eye and the second clevis eye; and

wherein the first and second pivot bosses extend through the single plate and the inner and outer torsion members.