Screw Leveller Attachment
Some of these machines have been converted by replacing the boom, described above, with a screw levelling attachment.
The drive to the screw is by roller chains and sprockets and bevel reduction gearbox.
The screw, of sturdy construction, is made up of fabricated steel flights on tubular steel core. The screw is supported at each end from the back-sheeting, with generous space between the discharge end of the flights and the support at that end to allow passage of spoil.
The control of the attachment achieved by the existing hydraulic rams in the vertical plane while the attachment is fixed to the machine frame by radius rods which allow tilting of the attachment.
A tension bolt safety device is incorporated in the final drive sprocket to protect transmission damage due to overload