Adjacent rear plate 17 and extending orthogonally thereto is a hollow tubular handle means 25 secured in situ between a first brace means 26 operatively interposed between side member 12 and handle means 25 and a second brace means 27 operatively interposed between side member 13 and handle means 25 by the insertion of a suitable securing means such as bolt 28 through a suitable aperture 51 define