Abstract: An electric terminal such as a transformer bushing having a contact socket of conducting material is provided with a quench tube arranged in aligned substantially coaxial relation with the contact socket. An associated connector which may be of the elbow type is provided with a contact pin which includes a tubular element of conducting material having an end of reduced diameter on which a hollow sleeve is disposed thereabout and formed of strong plastic material having an enlarged end nose portion of the same or of a different plastic material together with a sleeve of arc extinguishing material which is disposed about the plastic sleeve and arranged with one end in snug engagement with the enlarged end portion which is bevelled at its outer end to facilitate entry of the contact pin into and through the quench tube and into the contact socket so as to form a connection between the contact socket and the tubular element of conducting material.

Abstract: An arrangement for preventing relative rotation of electric terminals during a tightening operation comprises an electric conductor terminal having an electric contact surface through which an aperture extends and an associated terminal having a cooperating contact surface from which an integral stud protrudes, said stud being disposed within said aperture and having an associated fastening nut threadedly related with said stud for holding said contact surfaces in face contacting relation and said stud and said aperture being related by specially configured complementary portions for preventing relative rotation therebetween.

Abstract: An electric elbow connector comprises an L-shaped hollow housing structure formed of insulating material and of semi-conducting material which contains an elongated contact sleeve having a hollow sleeve portion at one end and an integral shank at the other end, the shank having an outer end portion of substantially larger transverse dimension than its inner portion and the outer portion of the shank being of a hardness considerably greater than the hardness of the inner portion of the shank and of the hollow end portion of the contact sleeve, and a contact pin in electric contact with the hard outer end portion of the shank of the contact sleeve and disposed within the housing.

Abstract: An electric terminal bushing having a hollow tubular contact engageable with the contact pin of an electric elbow type connector is arranged so as substantially to reduce the arcing time during a switch closing operation and includes means for slidably mounting the hollow tubular contact within the bushing between normal and interim positions, and spring means arranged to move said contact toward its normal position following movement of said contact toward its interim position during a circuit closing operation.

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: An electric terminal bushing having a hollow tubular contact engageable with the contact pin of an electric elbow type connector is arranged so as substantially to reduce the arcing time during a switch closing operation and includes means for slidably mounting the hollow tubular contact within the bushing, magnetic means connected in series with the contact for imparting sliding closing movement thereto in response to the striking of an electric arc between the contact pin and the tubular hollow contact, and latch means mounted on said hollow tubular contact for engaging a part of the bushing so as to hold said tubular contact in its circuit closed position following movement of said contacts to their closed circuit positions.

Abstract: An electric terminal such as a transformer bushing having a contact socket of conducting material is provided with a quench tube arranged in aligned substantially coaxial relation with the contact socket. An associated connector which may be of the elbow type is provided with a contact pin which includes a tubular element of conducting material to the end of which a stem of mechanically strong plastic material is affixed to support a hollow sleeve disposed thereabout and formed of arc extinguishing material and which is bevelled at its outer end to facilitate entry of the contact pin into and through the quench tube and into the contact socket so as to form a connection between the contact socket and the tubular element of conducting material.

Abstract: An electric terminal bushing having a hollow tubular contact engageable with the contact pin of an electric elbow type connector is arranged so as substantially to reduce the arcing time during a switch closing operation and includes means for slidably mounting the hollow tubular contact within the bushing and magnetic means connected in series with the contact for imparting sliding closing movement thereto in response to the striking of an electric arc between the contact pin and the tubular hollow contact.

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.