Abstract: Retractable cryogenic leads for superconducting magnets are provide for making low resistance contacts at liquid helium temperature reliably in the presence of heavy frost. A tube defining a bayonet socket on one end extends through a vertical stack cover of a cryostat insert to engage and disengage a vertical terminal rod having a transverse pin. A copper rod is slidably mounted inside the tube and is vertically displaced relative to the tube by a nut rotatably mounted on the other end of the tube and threadingly engaged with the copper rod. The end of the copper rod can be forced against the top of the vertical terminal rod at high pressure after the bayonet socket engages the pin of the vertical terminal rod.

Abstract: The optical properties of circular prisms, which are also known as axicons, are utilized in optical systems that generate one or more quiescent, steady in time, sharply focused circular and arc-shaped patterns of light. A laser beam incident on the circular prism is deviated by the prism effect and the emerging beam focused onto a target surface by a spherical lens or zoom lens; the radius of the circle is conveniently adjusted. Systems with stationary optics are described to efficiently form two concentric, uniform circles, or two offset circular or approximately circular arcs, from input beams derived from one or two lasers. These structured light patterns are used in tracking an edge or groove, for instance to locate the workpiece joint in robotic arc welding.

Abstract: Optical triangulation is used for determining the profile of a surface with only two photomultiplier tubes needed for optical sensing in a flying spot camera system. A feedback arrangement varies the angle at which a laser beam is applied to the surface such that the image of the beam on the surface tends to be maintained constant with respect to a linear reference position parallel to a scanning direction. Deviations in the image from its reference position as caused by surface height variations are used in the feedback arrangement to change the deflection angle. The deflection angle is in turn detected and is indicative of the variations in surface height. As an anti-noise feature, amplitude modulation is impressed upon the laser beam directed towards the surface and a filter network is used to filter photomultiplier response so as to exclude response to background optical noise.

Abstract: A system and method for monitoring vibrations of a machine tool metal-cutting tool insert and interpreting them to promptly detect the initial touch to the workpiece and signal the tool to stop advancing before marring the surface. The signal generated by a sensor such as an accelerometer is preprocessed to eliminate lower frequency machine noise and detect the energy in a higher frequency band, then sampled and analyzed by digital circuitry. In order to avoid false alarms on high amplitude spiky noise pulses generated by traverse operation of the machine tool, the tool touch alarm is delayed longer than the maximum duration of the noise pulses. Two techniques are given to ignore the noise spikes while still detecting the tool touch signal.

Abstract: A compact gas tungsten arc welding torch, which may have an integral puddle view optical system, utilizes an inert gas supply line and coolant supply and return lines, one carrying current for the weld process. The torch body has passages for flow of cover gas from a connection tube to the gas nozzle. The gas supply hose additionally carries the filler wire for the weld process, which passes into the gas connection tube and out of the torch body to an integral wire feed guide tube that is alternatively inside or outside of the gas nozzle.