Abstract: A transducer having a cross field polarized permanent magnet mounted for slight pivotal movement within an annular coil winding. The magnet comprises neodymium-iron-boron to provide a compact, lightweight, low inertia and high intensity magnetic field. A magnetic field generated by current in the coil winding influences the permanent magnet to pivot slightly about a horizontal axis and rotate a yoke structure to produce a mechanical output of the transducer. In the preferred embodiment of the invention, the yoke is attached to a spring arm for controlling escape gas pressure from a nozzle to thereby control the pressure of a gas stream.

Abstract: A transducer having a cross field polarized permanent magnet mounted for slight pivotal movement within an annular coil winding. The magnet comprises neodymium-iron-boron to provide a compact, lightweight, low inertia and high intensity magnetic field. A magnetic field generated by current in the coil winding influences the permanent magnet to pivot slightly about a horizontal axis and rotate a yoke structure to produce a mechanical output of the transducer. In the preferred embodiment of the invention, the yoke is attached to a spring arm for controlling escape gas pressure from a nozzle to thereby control the pressure of a gas stream.

Abstract: Apparatus for converting an analog-format electrical signal or quantity (such as the magnitude of an electrical circuit element) into a corresponding pulse-format signal, preferably in the form of a train of periodic pulses the lengths of which are controllable as a percentage of the cyclic period. A pulsed duty-cycle signal is developed in a negative feedback loop around an integrator having an analog-format input signal. The integrator output controls the d-c level of an up-and-down ramp signal which is fed to a comparator to produce pulses during the times the ramp voltage is above (or below) the firing threshold of the comparator. These pulses control a switch between the integrator input and a reference voltage so as to produce a negative feedback signal for the integrator.

Abstract: A combined pump and oil reservoir and oil delivery apparatus directs oil to the internal chambers of a portable sewing machine where oil is distributed by pump pressure, gravity flow, capillary action, wicking, misting and movement of machine components. Oil is pumped into a manifold leading to upper and lower main drive shaft bearings and to the needle driving assembly for subsequent dispersion during rotation and reciprocation of machine parts to fling such oil outwardly within the internal chambers to oil machinery both directly and by misting.

Abstract: A portable bag-closing sewing machine is provided with a self-oiling system which includes an oil reservoir connected to the machine and oil-delivery means to direct oil from the reservoir into the inner chambers of the machine where oil is distributed by gravity flow, capillary action and movement of machine components, the oil moving along through the machine components and through a series of channels, troughs, and reservoirs within the housing to distribute oil throughout the machine. During operation, the rotating and reciprocating machine parts fling oil outwardly within the chambers to directly oil machine assemblies and to create a fine mist of oil throughout the chambers so as to further lubricate machine components. Also disclosed is an improved and self-lubricating feed dog assembly and thread chain cutting device.

Abstract: A positioning device for controlling a member such as a pen of a chart recorder, wherein the positioning motion is produced by a wire formed of temperature-responsive material (Nitinol) exhibiting a martensitic transformation which contracts the wire when its temperature is increased within a predetermined temperature range, and relaxes the wire when cooled within that range. The wire is maintained under tension by a spring having a negative spring-rate. This spring cooperates with internally generated forces and the elasticity of the wire material to produce contraction/expansion length changes of the wire in response to changes in its temperature. Electrical circuitry for controlling the wire temperature is disclosed, and includes means for inductively developing a frequency-modulated pulse-current through the wire.

Abstract: Flow-metering apparatus of the vortex-shedding type wherein an obstruction in a flowing fluid develops a series of vortices which are sensed by a pressure-responsive piezo-electric element to produce an alternating voltage having a frequency corresponding to the fluid flow rate. The piezo-electric voltage signal is processed by electronic circuitry to provide for precise detection of the zero-crossings of the voltage alternations. The resulting frequency signal controls the charge/discharge characteristics of a set of capacitors, with the average charging current corresponding in magnitude to the frequency of vortex shedding. This average current controls an output amplifier in a feedback arrangement to produce a relatively high-powered d-c flow signal over a two-wire transmission line leading to a remote station. In another arrangement, a high-powered pulsating flow signal is developed for transmission over a three-wire transmission line leading to a remote station.

Abstract: A positioning device for controlling a member such as a pen of a chart recorder, wherein the positioning motion is produced by a wire formed of temperature-responsive material (Nitinol) exhibiting a martensitic transformation which contracts the wire when its temperature is increased within a predetermined temperature range, and relaxes the wire when cooled within that range. The wire is maintained under tension by a spring having a negative spring-rate. This spring cooperates with internally-generated forces and the elasticity of the wire material to produce contraction/expansion length changes of the wire in response to changes in its temperature. Electrical circuitry for controlling the wire temperature is disclosed, and includes means for inductively developing a frequency-modulated pulse-current through the wire.

Abstract: A combined pump and oil reservoir and oil delivery apparatus directs oil to the internal chambers of a portable sewing machine where oil is distributed by pump pressure, gravity flow, capillary action, wicking, misting and movement of machine components. Oil is pumped into a manifold leading to upper and lower main drive shaft bearings and to the needle driving assembly for subsequent dispersion during rotation and reciprocation of machine parts to fling such oil outwardly within the internal chambers to oil machinery both directly and by misting.