Patent ID: 6874583

Claim:
A coupling mechanism comprising: a frame having a cross member and left and right side members projecting from the cross member; the cross member having a pair of spaced apart upper mounting tabs projecting from an upper surface of the cross member, each upper mounting tab having a mounting bore extending therethrough; the cross member having a pair of spaced apart lower mounting tabs projecting from a lower surface of the cross member, each lower mounting tab having a lower mounting bore extending therethrough; the right side member having a pair of spaced apart right mounting tabs projecting from a lower end of the right side member, each right mounting tab having a mounting bore extending therethrough; the left side member having a pair of spaced apart left mounting tabs projecting from a lower end of the left side member, each left mounting tab having a mounting bore extending therethrough; a first upper hook having first dimensional characteristics; a second upper hook having second dimensional characteristics which are different from the first dimensional characteristics, either of said first or second upper hooks being mountable to the cross member; a first right lower hook having first dimensional characteristics; a second right lower hook having second dimensional characteristics which are different from the first dimensional characteristics, either of said first or second right lower hooks being mountable to the right side member; a first left lower hook having first dimensional characteristics; a second left lower hook having second dimensional characteristics which are different from the first dimensional characteristics, either of said first or second left lower hooks being mountable to the right side member.