Abstract: Blades on a rotating grinding plate force waste against a stationary grinding ring. The blades are mounted on radially aligned guides on the grinding plate, allowing the blades to move freely inwardly and outwardly between opposing stops. The blades are thrown outward by rotation of the grinding plate. A receding face on the blades cooperates with the grinding ring for moving the blades inwardly and for forcing waste against the grinding ring.

Abstract: Blades on a rotating grinding plate force waste against a stationary grinding ring. The blades are mounted on radially aligned guides on the grinding plate, allowing the blades to move freely inwardly and outwardly between opposing stops. The blades are thrown outward by rotation of the grinding plate. A receding face on the blades cooperates with the grinding ring for moving the blades inwardly and for forcing waste against the grinding ring.

Abstract: A winch for opening and closing an umbrella includes a winch drum mounted within an elongate support tube of the umbrella, to rotate about a longitudinal axis thereof. A threaded shaft is coaxial and rotationally fast with the drum. A line is fixed at one end to the drum and at other end to a sleeve, to which struts are pivotally connected, each strut being associated with a canopy-supporting rib. A travelling nut is engaged with the threaded shaft and blocked for rotation relative to the tube. A guide is fixed to the nut for guiding the line onto the drum, and a motor is also enclosed in the support tube and drivingly connected to the winch drum.