A novel retrofit process for converting the hydraulic lathe of an existing pulp-grinding machine into the new electric one is described. This process includes utilization of the pre-existing hydraulic cylinder as a supporting housing and shield for a major portion of the drive assembly for the electric lathe. In the preferred "retrofit" embodiment, the drive for the lathe comprises a ball-screw assembly housed inside the cylinder, after the cylinder has first been evacuated. This drive assembly includes a longitudinally fixed, but rotatable "power screw" that is supported by opposite ends of the cylinder. A variable speed, reversible motor is located outside one of the cylinder ends and is coupled to the screw to selectively rotate it. A threaded collar is located inside the cylinder and straddles the screw. It carries a pair of parallel, spaced rods that extend through the end of the cylinder that is opposite the cylinder's "motor end". These rods are connected to a yoke which, in turn, is connected to the standard carriage-carrying burr mandrel or "dressing wheel" used in the prior hydraulic lathe.
A method and apparatus for converting a conventional mechanical or hydraulic system for driving the infeed and outfeed rolls of a planer mill or a similar conveyor to variable frequency electric power. The method involves disconnecting the roller shafts from pre-existing mechanical and hydraulic drive components housed within the conveyor gearbox or other support frame. The electric motors are mounted at fixed positions on a panel rigidly connected to the gearbox or other support frame at a location spaced-apart from the roller shafts. Each motor is coupled to a corresponding roller shaft by means of a connector drive shaft having universal joint couplers at each end thereof. This arrangement permits displacement of the roller shafts during normal operation of the conveyor without transferring torque forces to the electric motors. The speed of each motor and hence each roller may be independently controlled by a frequency inverter which is operable by remote control.
An in-ground mechanical vehicle lift apparatus including an outer cylinder and a support tube rigidly attached to the outer cylinder. A ram cylinder is located between the outer cylinder and support tube in telescoping relationship to the outer cylinder and the support tube. The drive motor is mounted to the ram cylinder and a drive screw is operably connected to the drive motor for engaging a nut rigidly attached to an upper end of the support tube. The drive screw is driven in rotation by the motor to cause the ram cylinder to move upwardly and downwardly relative to the outer cylinder, and a vehicle support portion is located on an upper end of the ram cylinder for engaging and supporting a vehicle. The lift apparatus is adapted to be installed as a replacement for an in-ground hydraulic lift system wherein the lift apparatus is of a compact design which will fit within an existing in-ground cylinder of the hydraulic system.
