Abstract: A magnetic chuck control system employing solid state circuitry including a power output circuit adapted to apply a DC voltage to an object such as a magnetic chuck or the like so as to magnetize the same. The power output circuit employs a triac reversing circuit and is interfaced with a digital control circuit and a digital-to-analog converter circuit so as to apply alternating polarity voltage signals of successively reduced magnitude to the chuck during a demagnetizing operation. All high voltage is confined to the power output circuit so as to provide significant safety protection to the operator.

Abstract: An improved opening closure system utilizing a plurality of curtains supported in a way to cover the opening with alternate embodiments having primary and secondary curtains acting as a thermal siphon and with fan units as a power air destratifier.

Abstract: A fuel supply and ignition control system for controlling the operation of pilot and main valves in an intermittent pilot type system. At the start of an ignition cycle, the pilot valve is operated to supply fuel to a pilot outlet for ignition by sparks generated by a spark generating circuit. When the pilot fuel is ignited, the pilot flame bridges the spark gap, and a flame sensing network, which is connected in circuit with the spark electrodes, generates a flame signal which is applied to an enabling circuit which responsively effects operation of the main valve. The enabling circuit includes a controllable switching device which in one embodiment, is maintained disabled in the absence of a flame signal and is enabled to cause a flame relay to operate and energize the main valve when a flame signal is provided.

Abstract: This invention relates to an improvement in control apparatus which prevents formation of smoke in a combustion process. The conventional control includes apparatus for first providing the proper flow of either air or fuel to the process to satisfy the required demand for heat. A ratio device is then used to determine the flow of the remaining component necessary for obtaining proper combustion conditions. Where the BTU content of the fuel is likely to vary, a device for analyzing stack gases, typically an oxygen probe is then used to provide a signal to adjust the ratio device based on conditions indicated by the stack gases. The improvement of this invention includes a device for determining when the proportion of the exhaust gas component is outside limitations indicating smoking may occur and an emergency control device actuated when such conditions exist for rapidly adjusting the proportions of fuel and air supplied to the process in order to prevent smoking.

Abstract: An ignition system for use with a source of dc (or full-wave-rectified) power without the need for an inverter includes a flame sensing relay and a checking relay interlocked to achieve lockout if the proper starting sequence or timing are not met or if a flame-out occurs during operation. The checking relay is energized in response to a call-for-heat signal to isolate the flame detection circuitry from its source and commence a trial-for-ignition period in the flame detection circuitry which includes a timing circuit. The timing circuit actuates the flame-sensing relay during the trial-for-ignition period. The flame sensing relay energizes the fuel valve and a spark generator to ignite the fuel. If a flame is detected during the trial-for-ignition period by a flame probe, the timing circuit is disabled and operation continues until the call for heat is terminated as long as the flame is sensed. Another circuit senses flame at the spark gap and disables the spark gap generator after a flame is established.

Abstract: A probe for the measurement of the level of conductive materials within a conductive vessel is disclosed which is particularly suitable for the measurement of the level of conductive granular materials such as coal or other minerals or plastics or vegetable matter which are conductive. In a preferred embodiment the probe comprises a conductive steel core covered with a layer of insulating plastic and covered further with a layer of a semi-conductive material which preferably comprises a plastic which has been partially filled with a conductive material such as carbon black. Other embodiments wherein the probe may comprise a conductive plate covered by insulation further covered by a similar semi-conductive layer are also disclosed. Reference is made to prior art disclosures of circuitry and theory which enable the use of the probe of the invention.

Abstract: A printed circuit board with electronic components wired thereto has a conformal insulating coating consisting of a single component of essentially pure urethane formulation and a minor amount of fumed colloidal silica powder. The insulating coating covers asperities and protrusions as well as the conductors and circuit components while maintaining a transparent characteristic. The coating material is made by mixing of the small proportion of silica with essentially pure urethane formulation under controlled conditions to prevent moisture contamination of the materials. The mixture is thoroughly mixed, deaerated under reduced pressure with a pulsating pressure to break any air bubbles and remove essentially all air. The coating is applied in an environment having at least 30 percent relative humidity and within a confined area defined by an encircling dam masking compound. The coating is allowed to partially cure at room temperature and the confining dam compound removed.

Abstract: A bleed valve assembly which includes a bleed valve seat having a bleed orifice partially defined thereby and a piezoelectric crystal mounted adjacent thereto so that upon bending of the crystal, as by energization thereof, pressure contact is made with an intermediate valve element. The valve element is in turn adapted to move against the bleed valve seat to close the same. When the bleed valve assembly is closed in the manner above described, pressure is permitted to build up in the orifice to modify the position of a main valve with which the bleed valve assembly is utilized. In addition the crystal is beam mounted within a bore in which the valve seat is positioned and essentially in contact with said bore solely at spaced peripheral edge positions thereof.

Abstract: A continuous process for imparting a charcoal-broiled flavor and appearance to meat products, moves the product into impingement with open gas flames to sear the product's surfaces and to brand the upper and lower product surfaces with hot, metal branding elements.The food treatment apparatus has a housing furnished with product inlet and outlet conveyors. Movable branding apparatus disposed between the conveyors are heated by open flame gas burners. The conveyors and branding apparatus are driven in synchronization so that the product may move from the inlet conveyor to the branding station and thence to the outlet conveyor for further treatment.

Abstract: A web severing device has a pair of spaced-apart carriages straddling the path of the web, a severing blade being attached to one of the carriages. Power apparatus are provided for moving the carriages toward each other to bring the blade into severing contact with the web. Resilient apparatus are provided to prevent activation of the severing blade if a relatively rigid foreign object such as a human finger is accidentally embraced between the carriages and to prevent injury. When only the web is disposed between the carriages a portion of the resilient apparatus also functions to urge the blade-carrying carriage into web severing contact.

Abstract: A system for injecting foam insulation into a wall cavity or the like that includes a flow control section having a detecting means for automatically inhibiting the control section when the gun is placed in an inoperative or off condition.

Abstract: A programmable multi-channel automatic control system is disclosed. A user-accessible front panel is prorammed by the insertion of program pins into program time slots that correspond to one hour increments of a 24 hour day. Two detent positions of the program slot enable the user to select two distinct on/off schedules for each of the individual program channels. Seven-day program slots for each individual program channel are provided to allow selected equipment to operate on alternate schedules and/or to remain on or off for complete 24 hour periods.

Abstract: A system for positioning a web of material as it enters and passes through a course for treating the web, as in a printing press, is disclosed. The edges of the web are scanned by infrared sensing devices which are connected by various electrical circuits to a tilt mechanism contacting the web, and both the scanning devices and the tilt mechanism may be synchronized, or manually controlled, to direct the web through the press. A broad diameter channel of infrared radiation is utilized in the scanners. The relationship of the web to its desired path and the correcting actions of the system may be continuously read in terms of actual deviation changes on a display panel. The tilt rollers and the scanners may be automatically centered on a fixed reference point in preparing the web for its course through the press. The system includes correlation of the tramming of the tilt rollers to continued position sensing of the web by the infrared scanners.

Abstract: A variable air flow volume conditioned air distribution system of the kind having an air flow duct for supplying conditioned air to a room and a valve in the duct for regulating the volume of air flowing through the duct has a controller which senses the flow velocity in the duct and the room temperature in the room.The controller combines a temperature signal with a flow velocity signal through a velocity spring. A temperature change resets the flow velocity set point and produces a corresponding change in the volume flow through the duct.The controller includes an adjustable bias for the velocity spring for varying the rate of the velocity spring from a low spring rate for control at a low maximum permitted flow velocity in the duct to a higher spring rate for control at a higher permitted maximum flow velocity flow in the duct and vice versa.

Abstract: A mixed air conditioning controller is formed as a factory assembled and adjusted unit in a compact housing, with simple and direct input/output field connectors. Various temperature and humidity input devices are field connected to produce a sequenced control of the air dampers and mechanical cooling and heating devices, as well as auxiliary devices. The controller includes a primary input related to room demand, an outside air temperature input, with an interlocked control to the damper, a fan status input, a minimum air supply control and a by-pass switch having a low limit input. The logic network connecting the input/output includes pneumatic switching, pressure selecting and comparing devices of a diaphragm-controlled-orifice construction connected to function as fluidic repeaters, pressure regulating valves and pressure isolating and switching devices. The controller includes a conditioning channel and a damper channel.

Abstract: Electromagnetically operated contactor or relay in which the stationary magnetic core and operating coil are mounted in a base section and the movable armature and the switching elements are mounted in a main frame section. With the two sections assembled together the pole face structures of the stationary core abut reference surfaces in the main frame section. When the operating coil is energized, the armature moves into contact with the pole faces of the stationary core. Thus, since the reference surfaces in the main frame section determine the position of the stationary core pole faces and hence the position of the armature when the core is energized, the positions of all movable elements are determined solely by dimensions of the main frame section independently of the base section.

Abstract: Low impedance gas display panel voltage driver circuit is disclosed for driving conductor segments imbedded in gas display panel, wherein such conductor segments present a capacitive load, and where input to driving circuit is digital logic signal from standard transistor-transistor logic (TTL) circuit, the driver circuit and variations thereof being suitable for coupling to one or a plurality of conductor segments in a gas display panel.