Abstract: A wood-turning lathe includes a spindle and a drive shaft journalled to a headstock housing. A motor is mounted in the headstock housing, and includes a rotor. A torque converter includes a first wheel that co-axially surrounds the spindle and that is securely coupled to the rotor, a second wheel mounted securely on the drive shaft, and a belt trained on the first and second wheels, thereby increasing torque of the drive shaft. A speed change device includes a first pulley unit mounted on the drive shaft and defining a first belt-engaging surface, a second pulley unit mounted on the spindle and defining a second belt-engaging surface, and a non-elastic belt interconnecting the first and second pulley units and frictionally contacting the first and second belt-engaging surfaces.

Abstract: A lathe is provided with a stepless cutter feeding mechanism for cutting a workpiece at a constant linear cutting speed. The lathe includes a cutter seat that carries a cutter for cutting the workpiece and a motor for driving a main shaft that carries the workpiece. The stepless cutter feeding mechanism comprises a speed sensing device connected to the cutter for sensing linear cutting speed of the cutter. A governor device is connected to the speed sensing device and electrically connected to the motor for changing rotational speed of the motor in response to a linear cutter feeding speed of the cutter such that the cutter cuts the workpiece at a constant linear cutting speed.

Abstract: A speed change gear mechanism for lathes includes a driving shaft having a number of first gears securely mounted thereon to rotate therewith, a driven shaft including a number of second gears each rotatably mounted thereon via a bearing, and a chuck shaft including a number of third gears securely mounted thereon to rotate therewith. The number of the second gears is a sum of the number of the first gears and the number of the third gears. Each second gear is meshed with a corresponding one of the first gears and the third gears. A camshaft includes a cam formed thereon, the cam having a number of angular positions that correspond to different speeds of the chuck shaft. A clutch device has a first end selectively engaged with two of the second gears that respectively meshed wvith an associated first gear and an associated third gear to thereby determine a rotational speed of the chuck shaft.

Abstract: A retrofit for an electronically programmable, servo-controlled power feed and spindle drive system for controlling the spindle and cam shaft drive of an automatic screw machine. The automatic screw machine originally provides rotational power to the spindles of the cam shaft drive through a complex series of gears, shafts and clutch systems. The gears, shafts and clutch systems also provide synchronization between the rotation of the spindles and the rotation of the cam shaft drive. A retrofit of the automatic screw machine includes replacement of the complex series of gears, shafts and clutch systems with a variable speed drive motor, a chain drive system, an electronic encoder for monitoring the rotational speed of the spindle shaft, an electric servo motor for providing rotational power to the cam shaft drive and a central processing unit to synchronize the speeds of the variable speed motor and electric servo motor.