Patent ID: 7165469

Claim:
A quick access and easily replaceable seal arrangement for a shift rod piston in a vibratory plate compactor in which a main rotating input shaft is journaled in a main housing, the housing including a liquid lubricant reservoir, said input shaft having an axial bore in which a shift rod carrier head is journaled on the end of the shift rod opposite the piston for operative adjustable connection to the input shaft, a cylinder housing attached to the main housing and having a bore coaxial with the input shaft bore, said housing bore sized to receive the shift rod piston, and the cylinder housing having a connection to a supply of pressurized hydraulic fluid for pressurizing the cylinder housing and the head end of the piston to move the shift rod axially in the input shaft bore, the shift rod end of the piston exposed to the liquid lubricant, said arrangement comprising: a threaded connection for demountably attaching the piston to the shift rod; seal means providing a hydraulic fluid seal and a liquid lubricant seal between the piston and the cylinder housing bore, the hydraulic fluid seal inhibiting the passage of hydraulic fluid past the piston from the head end to the rod end, and the liquid lubricant seal inhibiting the passage of liquid lubricant past the piston from the rod end to the head end; and, a mounting device for demountably attaching the cylinder housing to the main housing.