Wing plow apparatus

1. A wing plow assembly comprising:

a base configured for attachment to a vehicle;

an upper arm attached to said base, said upper arm being rotatable about a first axis;

a lower arm attached to said base, said lower arm being rotatable about a second axis;

a lifting member attached to said base, said lifting member being rotatable about a third axis;

a support pivotally attached to said upper arm and said lower arm, said support comprising an attachment configured for attaching a plow to said assembly; and

an actuator pivotally attached to said base and said lifting member;

wherein said actuator is configured for raising and lowering said support by engagement of said lifting member with said upper arm;

wherein said lifting member is rotationally decoupled from said upper arm such that said upper arm is disengageable from said lifting member in a disengaged position.

2. The wing plow assembly of claim 1 wherein said first axis and said third axis are the same.

3. The wing plow assembly of claim 1 wherein said first axis and said second axis are substantially parallel and vertically aligned.

4. The wing plow assembly of claim 1 wherein at least one of said first axis and said second axis is configured to be substantially parallel to a longitudinal axis of the vehicle when said base is attached to the vehicle.

5. The wing plow assembly of claim 1 wherein said upper arm and said lower arm are respectively pinned to said support about a fourth axis and a fifth axis.

6. The wing plow assembly of claim 5 wherein said first and second axes are substantially parallel and vertically aligned with each other, and wherein said fourth and fifth axes are substantially parallel and vertically aligned with each other.

7. The wing plow assembly of claim 1 wherein said upper arm comprises a pair of spaced apart links.

8. The wing plow assembly of claim 1 wherein said lower arm comprises a pair of spaced apart links.

9. The wing plow assembly of claim 1 wherein said lifting member comprises a first bearing plate configured for engagement with a second bearing plate of said upper arm.

10. The wing plow assembly of claim 9 wherein said upper arm comprises a lifting plate having an underside comprising said second bearing plate.

11. The wing plow assembly of claim 10 wherein said lifting plate is configured to cover said actuator.

12. The wing plow assembly of claim 1 wherein said actuator comprises a hydraulic actuator having a cylinder and a piston, wherein one of said cylinder and said piston is pinned to said base and the other of said cylinder and said piston is pinned to said lifting member.

13. The wing plow assembly of claim 1 wherein, when said base is attached to the vehicle and the plow is mounted to said wing plow assembly, the plow is biased toward a down position during plowing operations due to a lateral resultant force component acting on the plow at an elevation below said first and second axes.

14. The wing plow assembly of claim 1 wherein a range of motion of said upper arm and said lower arm is limited by engagement of an edge of said base with an edge of said support.

15. The wing plow assembly of claim 1 wherein said upper arm and said lower arm are configured to extend substantially perpendicular to a longitudinal axis of the vehicle when said base is attached to the vehicle.

16. A wing plow assembly comprising:

a base configured for attachment to a vehicle having a longitudinal axis;

an upper arm comprising a first pair of spaced apart links pinned to said base at a first upper axis, said upper arm configured for extending substantially perpendicular to the longitudinal axis of the vehicle;

a lower arm comprising a second pair of spaced apart links pinned to said base at a first lower axis, said lower arm configured for extending substantially perpendicular to the longitudinal axis of the vehicle, said first lower axis being substantially parallel to and vertically aligned with said first upper axis;

a support pinned to said upper arm at a second upper axis and pinned to said lower arm at a second lower axis, said support comprising an attachment configured for attaching a plow to said assembly, said second upper axis being substantially parallel to and vertically aligned with said second lower axis;

a lifting member pinned to said base at said first upper axis, said lifting member comprising a third pair of spaced apart links disposed intermediate said first pair of spaced apart links; and

an actuator comprising a piston and a cylinder disposed intermediate each of said pairs of spaced apart links, one of said piston and said cylinder being pinned to said base and the other of said piston and said cylinder being pinned to said lifting member;

wherein said actuator is configured for raising and lowering said support by engagement of said lifting member with said upper arm;

wherein said lifting member is rotationally decoupled from said upper arm such that said upper arm is disengageable from said lifting member in a disengaged position;

wherein each of said first upper axis, said first lower axis, said second upper axis, and said second lower axis is configured to be substantially parallel to the longitudinal axis of the vehicle when said base is attached to the vehicle.