Abstract: A golf club is disclosed that can be used with a structure of a golf club head that has a space between the front striking face and the back piece of the club head. The front face and the back piece are attached to each other at the heel edge and the toe edge. This new club head can replace the presently used perimeter weighting with this new heel and toe weighting. This new club head is able to strike a golf ball more accurately and with more control. With rotation of the shaft on the club head, the golf club can become a four way device whereby the front face, the back face, the heel edge or the toe edge may be used to strike a golf ball. With a rotatable shaft that is moveable on the golf club head at the heel edge, at the toe edge or at the central part of the back piece, the golf club can become a four way device for a left hander or a right hander. The front face, the heel edge, the toe edge or the back face can be used to strike a golf ball.

Abstract: A servo system for the rotary spindle of a machine tool in which the spindle is driven by a drive motor through a gear train having shiftable gears for changing the rate of rotation of the spindle. The transducer for the servo system is mounted directly on the motor drive shaft in order to avoid all backlash between the resolver and the drive motor. However, the transducer is arranged to regulate the angular orientation of the spindle and must therefore be maintained in synchronism with the spindle. This is accomplished by arranging the shiftable gears so that when they are moving into engagement with a new gear, engagement with the previously engaged gear is maintained until initial engagement with the new gear is achieved. Further shifting movement into full engagement with the new gear operates to release the previously engaged gear. Thus, during the initial engagement with the new gear, the shiftable gear is momentarily in engagement with both gears.

Abstract: The voltage and frequency of an A.C. excitation signal applied to the stator windings of an A.C. induction motor are varied in proportion to the amplitude of current flowing in the stator windings. The stator current flow is sensed by a feedback resistor in series with the inverter which generates the A.C. excitation signal for the stator windings. The voltage drop aross the feedback resistor is summed with a VELOCITY COMMAND voltage which indicates the desired speed of the motor and the summed voltage controls the frequency and the amplitude of the A.C. excitation voltage in a constant volts per hertz manner. The stator current feedback holds the motor speed constant in spite of variations in the load on the motor.

Abstract: A tachometer is coupled to the rotor of an A.C. motor and generates an output voltage proportional to the rotor's speed. A VELOCITY COMMAND voltage is generated having an amplitude which specifies a desired rotor speed. The tachometer voltage is subtracted from the VELOCITY COMMAND voltage to produce a VELOCITY ERROR voltage. The output of a D.C. power source is chopped at a fixed frequency and variable pulse width, the pulse width being proportional at any time to the amplitude of the VELOCITY ERROR voltage. The chopped D.C. voltage is filtered to provide a variable D.C. voltage having an amplitude which is proportional to the amplitude of the VELOCITY ERROR voltage. The variable D.C. voltage is applied to an inverter which changes it into an A.C. voltage. The A.C. voltage is applied to the stator windings of the motor to drive the rotor thereof. The frequency of the A.C. voltage is variable and is proportional, at rotor speeds above 150 RPM, to the amplitude of the velocity command voltage.

Abstract: A probe is mounted on the nose of a toolholder which fits into the spindle of a numerically controlled machine tool. An oscillator is mounted within the toolholder and is powered by a battery within the toolholder. The output of the oscillator is coupled to a primary coil on the toolholder which is inductively coupled to a ring-shaped secondary coil on the spindlehead of the machine tool. Switches within the toolholder are wired to the oscillator to cause it to shift frequency when the probe stylus makes contact with a workpiece when moving along any one of the X, Y or Z axes. The ring-shaped secondary coil is coupled to the machine tool's NC circuits to indicate when the probe makes contact with the workpiece.

Abstract: Two transistors each have their emitter-collector circuits coupled in series between one end of a motor field winding and the opposite terminals of a D.C. voltage source to switch current flow in either direction through the winding. Two current sensors are provided, one coupled in series with each emitter-collector circuit. The voltage developed across each current sensor is applied through a driver circuit to the base of the other transistor so as to cut one transistor off when the other is conducting and vice versa, thereby eliminating the possibility of having both transistors conduct simultaneously which would short out the voltage source and burn out one or both transistors.

Abstract: In apparatus for controlling the speed and torque of a multiphase a.c. motor in accordance with digital control signals, a first regulation circuit regulates the frequency of the a.c. electrical signal applied to the motor and another regulation circuit regulates the voltage of the a.c. signal. Both regulation circuits are controlled by digital control signals in a series of discrete steps over a range of control values and the control signals are supplied periodically to the regulation circuits. The speed and torque are controlled in accordance with an algorithm relating speed and torque to the frequency and voltage of the source of electric power which is applied to the motor, calculated by computing apparatus on a periodic basis. In one embodiment the position of the magnetic flux of the stator is controlled directly.

Abstract: In apparatus for controlling the speed and torque of a multiphase a.c. motor in accordance with digital control signals, a first regulation circuit regulates the frequency of the a.c. electrical signal applied to the motor and another regulation circuit regulates the voltage of the a.c. signal. Both regulation circuits are controlled by digital control signals in a series of discrete steps over a range of control values and the control signals are supplied periodically to the regulation circuits. The speed and torque are controlled in accordance with an algorithm relating speed and torque to the frequency and voltage of the source of electric power which is applied to the motor, calculated by computing apparatus on a periodic basis. In one embodiment the position of the magnetic flux of the stator is controlled directly.

Abstract: In apparatus for controlling the speed and torque of a multiphase a.c. motor in accordance with digital control signals, a first regulation circuit regulates the frequency of the a.c. electrical signal applied to the motor and another regulation circuit regulates the voltage of the a.c. signal. Both regulation circuits are controlled by digital control signals in a series of discrete steps over a range of control values and the control signals are supplied periodically to the regulation circuits. The speed and torque are controlled in accordance with an algorithm relating speed and torque to the frequency and voltage of the source of electric power which is applied to the motor, calculated by computing apparatus on a periodic basis. In one embodiment the position of the magnetic flux of the stator is controlled directly.

Abstract: In apparatus for controlling the speed and torque of a multiphase a. c. motor in accordance with digital control signals, a first regulation circuit regulates the frequency of the a. c. electrical signal applied to the motor and another regulation circuit regulates the voltage of the a.c. signal. Both regulation circuits are controlled by digital control signals in a series of discrete steps over a range of control values and the control signals are supplied periodically to the regulation circuits. The speed and torque are controlled in accordance with an algorithm relating speed and torque to the frequency and voltage of the source of electric power which is applied to the motor, calculated by computing apparatus on a periodic basis. In one embodiment the position of the magnetic flux of the stator is controlled directly.

Abstract: A single drive and control means is selectively engageable to provide either rectilinear movement to the table base or rotary movement of an index table carried by the table base.

Abstract: A probe is mounted on the nose of a toolholder which fits into the spindle of a numerically controlled machine tool. An oscillator is mounted within the toolholder and is powered by a battery within the toolholder. The output of the oscillator is coupled to a primary coil on the toolholder which is inductively coupled to a ringshaped secondary coil on the spindlehead of the machine tool. Switches within the toolholder are wired to the oscillator to cause it to shift frequency when the probe stylus makes contact with a workpiece when moving along any one of the X, Y or Z axes. The ringshaped secondary coil is coupled to the machine tool's NC circuits to indicate when the probe makes contact with the workpiece.