Abstract: Apparatus for volumetrically feeding dry flowable bulk material. The apparatus comprises a hopper that receives dry flowable bulk material from a storage tank of dry flowable bulk material through a rotary valve located at the top of the hopper. At the bottom of the hopper is a sliding discharge gate for the discharge of dry flowable bulk material from the hopper. Mounted on the hopper in vertically spaced relation is a high level sensor and a lower level sensor. When the height of the dry flowable bulk material in the hopper is above a predetermined height, the high level sensor is activated for the closing of the rotary valve and the opening of the discharge gate. When the height of the dry flowable bulk material in the hopper is below a predetermined height, the low level sensor closes the discharge gate and opens the rotary valve. Thus, the bulk material level in the hopper is maintained within prescribed limits to control the pressure head of the bulk material for improved feed accuracy.

Abstract: An automatic chemical mixing system using a single level sensor, preferably an ultrasonic sensor, for monitoring the contents of a mixing tank. The level sensor provides an analog signal to a controller indicative of the level of liquid in the tank. Supply pipes from several sources of different chemicals lead to the tank through respective controllable valves. The required percentage of each chemical can be entered manually into the controller and each valve is opened in turn by the controller until the various percentages are reached. Provision is also made for adding small quantities of a further chemical which is supplied by a metering pump. The controller ensures that this is done after the other chemicals have been added. A mixer, also under control of the controller, starts running when all the chemicals have been added and stops when a predetermined low level is reached.

Abstract: A beverage dispenser in which a sensor provides an output corresponding to the level of the beverage in a storage reservoir from which the beverage is dispensed. In response to user actuation a dispensing valve is enabled for such a time interval, determined in accordance with the output of the sensor, as to compensate for variations in flow rate due to variations in the beverage level in the reservoir. The level sensor output is also used to control a level-indicating display and to disable the reservoir heater when the reservoir is empty. Preferably the sensor is a strain gauge adhered to the surface of a relatively thin resilient beam which supports a portion of the reservoir.

Abstract: An apparatus for dispensing material from a container comprising a plate having an aperture therein through which material is caused to flow out of the container when the plate is caused to move vertically within the container. A scraper member is spaced from and coupled to such plate to engage the inside walls of such container to scrape material from the walls as the plate moves vertically relative to the container. A space is formed between the scraper member and the plate to form a cavity which communicates with the aperture and which includes a material entering opening, the level of material in the cavity being controlled during operation of the apparatus.

Abstract: Liquid dispensing apparatus comprises a T-tube (9) of which the limb tube serves as a closed reservoir (8) for liquid, with an air space above. Liquid is pumped by a peristaltic pump (A) through a tube (6) and one arm of the T-tube into the reservoir until a level detector (D) responds to the liquid level in the reservoir reaching a datum level whereupon it renders the pump (A) inoperative. A further peristaltic pump (B) then starts to pump liquid from the reservoir out of the other arm of the T-tube and through tubes 13 and 15 to an infusion needle in a patient's body. When the liquid level in the reservoir reaches a predeterined lower level detected by another detector (E), the second pump (B) is rendered inoperative and the cycle is then repeated starting with operation of the first pump (A).The use of a peristaltic pump as the second pump (B) enables the liquid delivery pressure at the needle to be held just above the minimum necessary for infusion.

Abstract: In a wet cycle copier of the small tabletop mounted variety, conversion is made for vending in the absence of frequent key operator attention. Incidence of power interruption provides for a soak cycle to occur wherein the liquid toner is cycled through the machine without drum rotation. Rotation of a glass selenium coated drum against a dried and abrading liquid applicator is avoided. After the soak cycle and assuming uninterrupted power, a cleaning cycle is initiated once every 24 hours. Assuming a lack of machine use, this cleaning cycle lubricates both toner application roller and drum to assure a wet toner applicator. Dispersant replenishment is supplied from a large volume reservoir under logic control with provision made for automated machine shutdown where dispersant on demand is not supplied. Provided modes of operation include coin vending, countermechanism vending and direct owner access vending with a tamper proof interface between the provided modes.

Abstract: Apparatus is provided for monitoring the level of a liquid in a reservoir, especially in the situation where the liquid is a high temperature, molten material. The device operates as a static-tube differential pressure sensor and includes an open-ended tube with one end adapted for direct immersion in the liquid and with the other end being in pneumatic communication with a conventional differential pressure transducer. The meniscus of the liquid entering the tube essentially acts as a diaphragm membrane and eliminates the need for an immersible diaphragm, as conventionally used with static-tubes. The device may actuate a controller for compensating any change in the liquid level from a reference.

Abstract: Disclosed is a device for indicating that the level of a dosable material has fallen below a predetermined level in a dosing container having a shaft mounted horizontally for rotation inside of the container and a dosing brush mounted on the shaft. This device comprises an elastic contact tongue radially fixed to the shaft for rotation therewith, the contact tongue being sufficiently elastic so that it assumes a bent configuration having a first radius when rotated in contact over a predetermined portion of its length with the dosable material and so that it assumes an extended configuration having a second radius when rotated so that it is not in contact over the predetermined portion of its length with the dosable material; a contact pin mounted at a distance from the shaft greater than the first radius but not greater than the second radius, so as to be contacted by the contact tongue in its extended configuration; and means for producing a signal when the contact tongue contacts the contact pin.

Abstract: A liquid dispenser system for moving a measure of liquid through a conduit from a source container to a receiving container. A branched flow path is defined between a source of pressurized fluid via a first branch sealingly coupled to the source container and a second branch leading communicatively to said conduit at a location between the intake end and the delivery end. A valve is provided to direct the pressurized fluid along one of said first and second branches. A through coil is interposed between said second branch and said conduit. The first branch terminates above the liquid level of the source container. Pressurized fluid is first directed along said first branch causing liquid flow toward the delivery end of said conduit. When flow of the leading liquid is detected, pressurized fluid is directed to the said location along the second branch to split the flowing column of liquid to deliver the portion above the split to the receiving container and the rest back to the source container.

Abstract: A system for controlling operations of a process or of another system or apparatus which must perform its operations in precise time sequence. The control system also initiates the performance of successive cycles of such sequences of operations with the same precision of timing as the operations themselves. A timing generator which operates from or includes a constant frequency source produces pulses of constant periodicity which time the operations so that they occur in selected time sequence during each cycle, starting when a cycle is initiated. The timing of the operations and their duration may be preset for the process, apparatus or system to be controlled. A large timing range is provided to meet the needs of the particular process system or apparatus and to make adjustments as may be required in the field. The cycles of operation sequences may be selected in accordance with the mode of operation desired.

Abstract: The film developing machine includes a tank containing developing fluid, to which a dosing device continually adds regenerating fluid received from a regenerating-fluid supply tank. To prevent the gradual emptying of the supply tank from producing an accuracy-reducing gradual decrease in the pressure applied to the input side of the dosing device, the latter is connected to the supply tank via a buffer vessel provided with an internal valve mechanism serving automatically to keep the volume of regenerating fluid in the buffer vessel substantially constant despite variations in the amount of regenerating fluid contained in the supply tank.

Abstract: An apparatus is provided for filling the wells of an antibiotic plate with different concentrations of fluid including an array of fluid containers, each having a single needle valve inserted through a stopper member which is held in an open end of the container. Each needle valve includes an inner tube for supplying pressurizing air to one end of the containers which forces the fluid through an outer tube of the needle valve and out the opposite end of the container. A length of flexible tubing connected to each of the needle valve outer tubes carries the fluid through one of a plurality of slots formed in a pinch valve assembly. The pinch valve assembly includes slide members and resilient pinch rods extending laterally from sides thereof. In a first position, the slide members are held such that the pinch rods close the flexible tubing to prevent passage of the fluid into the wells of the antibiotic plate.

Abstract: A method and apparatus for automatically mixing a solution having a specified concentration is disclosed. The apparatus comprises: a storage tank, means for automatically introducing water into the tank, means for slowly introducing salt into the tank, and means for terminating the introduction of salt into the tank when the specific gravity of the tank reaches a specified value. Means are provided for preventing withdrawal of solution during the mixing cycle.

Abstract: A non-pressurized fluid transfer system for stock rotation of liquids packaged in large non-pressurized containers such as 55 gallon drums is described. Two drums or sets of drums are used and the system automatically changes over from a first drum to a second drum when the first drum no longer contains liquid. Automatic change-over between the first drum and second drum is effected in response to a signal created by a float switch in the drum's fluid line. This float switch detects the absence of liquid in the first drum and the system automatically switches to the second drum in order to maintain continuity of the dispensing process. When the first drum is replaced with a new drum, the operator pushes a purge button and the fluid line connected to that drum is purged of any air. Thus, the dispensing of fluid may be continuously maintained without any interruption from changing drums, and without introducing air into the dispensing line.

Abstract: A method and apparatus for controlling the feed of pieces of rubber or plastics material into the intake opening of an extruder where a feed roller has a control slide mounted thereabove which can be moved to increase or decrease the area of the surface of the roller which engages the material and thus the rate of material intake. Sensing means are provided to indicate to control means the level of material in the intake opening, the control means then operating the control slide to adjust the rate of intake of material.

Abstract: In an apparatus for the pulsewise dispensing of very small amounts of liquid controlled with a measuring instrument comprising an ejecting device for the pulsewise ejection of a desired amount of liquid, a pump is provided for supplying liquid to the vessel from a reservoir. The pump includes a neck portion having an inlet at the bottom thereof and a foot portion, with at least the foot portion immersed in a liquid contained in the reservoir. The foot portion has a volume at least as great as the refill volume of the measuring vessel and a feedline to the measuring vessel is disposed within the neck portion and terminates in proximity to the bottom of the foot portion. A check valve opens and closes the foot portion inlet by means of compressed gas which is controllable by sensing devices at the measuring vessel.

Abstract: A control system for an ice dispenser maintains an icemaker thereof continuously operative whenever an ice storage hopper is less than completely full. This is accomplished by continuing to operate the icemaker while momentarily agitating and leveling the mass of ice in the hopper whenever ice builds up around a thermostat therein, and thereafter sensing whether the ice has dropped away from the thermostat. If it has, the icemaker is maintained in operation and the cycle is repeated. If, however, it has not, then the icemaker is turned off until sufficient ice is dispensed from the hopper to again drop the ice level to below the thermostat. In this manner, the number of on-off cycles of the compressor and other components of the icemaker are minimized in maintaining the hopper completely full, which greatly increases their operating life and reliability.

Abstract: In an apparatus for the pulse-wise dispensing of very small amounts of liquid controlled with a measuring instrument. The measuring instrument comprises an ejector for the pulse-wise ejection of a desired amount of liquid and a measuring vessel having a volume greater than the volume of the liquid to be ejected for each pulse. The measuring vessel has an outlet connected to the ejector and a cross-section of the vessel is adapted to the amounts of liquid to be controlled. A sensing apparatus has an upper and lower sensing device positioned at the vessel and responsive to the level of the liquid therein with an accuracy of about from 1 to 5 amounts of liquid to be ejected and which generates a signal when the upper and lower sensing devices are activated.

Abstract: A sensor for determining the presence of a particular volume of fluid within a plurality of reservoirs maintained as a portion of an automatic mixed drink dispenser. Fundamentally, the invention includes electrical contacts maintained within each of the various reservoirs, the reservoirs being aligned into rows and columns to form a matrix. A multiplexing circuit is interconnected to the rows of such reservoirs while a sensing circuit is interconnected to the columns thereof. The addressing of the rows of reservoirs by the multiplexer enables a signal to pass across the contacts and through the beverage maintained within the reservoirs, this signal being sensed by the sensing circuit interconnected between the columns of reservoirs. "Empty" reservoirs, or those having a low beverage level, may be quickly isolated by a determination of the row accessed and the column sensed to result in the failure of a contact to pass a signal.

Abstract: This discloses a system for lifting or conveying granular, pulverized or fluid material from a first location to a second location. A long flexible tube, open at the ends, encloses a highly flexible rotary driven helical coil spring equipped at parallel, spaced-apart positions along its length with a plurality of attachments, called "portable flights", which may comprise a shallow cylindrical cup formed from a pair of semicircular plates. The cups are secured to a succession of rungs in angularly staggered relation along the length of the helical spring, and serve to pick up and convey a substantial quantity of the pulverized, granular or fluid material from an input container, in which the tube is immersed, to a product chute near the top of the tube leading into a collection hopper.

Abstract: A monitoring system for a water scalping sand classifying tank, comprising timers for measuring the cumulative total discharge times for at least two key classification stations of the tank over an extended period of time which may include many reblend cycles for the tank. Tolerance limits are established by use of at least two timers for each key station. Any extended variation in the desired ratio of total discharges for the key stations, indicating an input change requiring correction, is signalled by an indicator system coupled to the timers.

Abstract: Apparatus for continuously measuring rates of flow of a liquid has two containers arranged serially in the liquid flow path and each associated with a self-levelling balance beam. Beam displacement is measured capacitively and used to alter current fed to a coil tending to maintain the beam level. The magnitudes of the currents necessary to maintain the beams level is a measure of the liquid level in the containers and is used to keep the liquid levels between pre-determined upper and lower values by controlling valves through which the liquid flows into the containers. The differentials of the currents with respect to time when the liquid levels are falling in both containers, are added. If the liquid level in the first container is rising, however, no differential is provided whereas the differential of the second container liquid level, when rising, is supplied to the adder but negatively. The adder provides an output which is a measure of the volume of liquid supplied by the apparatus.

Abstract: In detecting the presence or absence of a developing agent or determining the residual amount thereof, at least one coil is arranged outside a developing agent container, so that a change in magnetic permeability caused by the presence or absence of a developing agent within the container or a change in the amount thereof can be detected as a change in the inductance of the coil.

Abstract: Disclosed are apparatus and method for detecting the presence, or absence, of material at a predetermined location. A crystal controlled oscillator generates a constant-frequency, constant-amplitude signal which is fed through a load resistor to an antenna sensor circuit, including an antenna probe positioned at the sensing location. The amplitude of the signal fed to the sensor circuit varies as the impedence of the antenna probe is affected by material in its environment, or the lack thereof. The signal amplitude is converted to a d-c voltage level, which is added to a reference d-c voltage level preset with the antenna probe free of impedance-affecting material. The difference voltage level value thus obtained, and which reflects the environment of the antenna probe, is used to control a switching circuit whose output assumes one value or another, depending ultimately on the antenna probe's environment.

Abstract: In the feeding of molten metal from a container therefor, e.g., a storage basin, a furnace or a crucible, to a chamber, e.g., an injection cylinder or a dispensing chamber, having an electromagnetic pump partially immersed in the container, the outlet of the pump being connected by a feedline to the chamber, the molten metal is metered by apparatus comprising a detachable ascending control pipeline connected to the feed pipeline, an electromagnetic presence detector arranged to detect molten metal in the control pipeline at the level of the filling height of the chamber, and a progressive voltage generator connected in series with the electrical circuit of the pump and including a starter circuit and a stop circuit to which the presence detector is connected.

Abstract: An apparatus for mixing photographic process chemicals, and supplying the mixed chemical to a film processing unit. The apparatus provides a chemical holding tank having a water supply inlet and a chemical discharge outlet thereon. The tank is provided with submersible pumps for agitating the contained chemical. Sensors on the inner portion of the tank detect when the process chemical reaches a minimal level whereupon water is added through the water inlet to fill the tank to its maximum whereupon the water supply is automatically shut off. In the preferred embodiment, an operation can add dry chemicals or liquid concentrate to form the finished process chemical. The sensors can be adjusted to vary water levels as needed for adapting the system to different chemical-water mix ratios as specified with the concentrated chemicals supplied by different manufactures.

Abstract: A copy machine having a decorator for applying toner to a latent image is disclosed. The decorator is fitted with a control for sensing the level of toner in the decorator sump which control automatically maintains the amount of toner in the sump at the desired level. The control includes a toner level sensor which is a vibrating rod driven by a decorator roll.

Abstract: The level of a metallic bath, e.g. of an iron melt in an ingot mold, is determined by recurrent electro-optical scanning of the interior of the vessel along a narrow vertical strip zone. The output signals of the scanner are processed in an arithmetic unit which averages successive readings, to compensate for fluctuations, and may also receive a corrective signal in order to offset periodic level changes due to an intentional rocking of the vessel. The arithmetic unit may work into a visual indicator and into a controller adjusting the rate of inflow and/or withdrawal to maintain the bath level substantially constant.

Abstract: Apparatus for dispensing a carbonated beverage including a source of propellant gas, a reservoir for beverage to be dispensed, one or more dispensing valves connected to the reservoir, a propellant gas conduit for applying a first gaseous propellant pressure upon beverage supply vessels and for applying a second and lesser gaseous propellant pressure upon beverage in the reservoir, a beverage supply conduit for transferring beverage from a supply vessel to this reservoir and normally closed valves in the beverage supply and gas conduits, which valves are controllable by a level sensor in the reservoir; the apparatus also features structure for automatically switching from one supply vessel to another as vessels become emptied; a method of dispensing includes the steps of providing a supply of carbonated beverage, applying a first propellant pressure upon the supply, selectively transferring beverage from the supply to a reservoir, applying a second and lesser propellant pressure upon the reservoir and dispens

Abstract: A recirculating carbonator and beverage dispenser requires only one pump. The system's function can be enhanced by the use of a two position spool valve having a fresh water inlet port, a carbonated water inlet port, and a fluid outlet port commonly connected with a central bore. A spool member is slidably disposed within the bore to selectively interrupt fluid communication between the carbonated water inlet port and the liquid outlet port during the presence of a low water signal generated by a level sensing device within the system's carbonation tank. During the interruption, fresh make-up water is added to the system. The level sensing device includes a body with a longitudinal bore therethrough, an inlet for the constantly flowing fluid, and a venturi tube depending from the body.

Abstract: A system for preparation of variable hemodialysate in which a controllable pump meters multiple fluid sources of dialysate concentrates and water in controlled proportion. The system includes a plurality of cylinder and piston pump assemblies linked together for simultaneous operation. Individual valves connect the separate pump assemblies to the individual fluid sources to be proportioned. A position sensor provides signals indicative of the position of the pistons throughout their stroke cycle, and with a control operates the control valves associated with the individual pump assemblies in accord with functions of piston position and preselected proportioning control inputs, so as to control the volume of fluid metered by each of the pumps during the pump stroke.

Abstract: The liquid nitrogen level in a flask is controlled by the degree of immersion of two sensing coils of copper wire in the liquid nitrogen activating a solid state switching circuit which controls a liquid nitrogen inlet flow valve. Manual override and sensor fault indication is provided.

Abstract: Apparatus for determining the height of a column of tobacco or similar particulate material in a downwardly extending channel, comprising a first capacitor, a second capacitor formed partly by an electrode plate extending above and below the desired average level of the top surface of the tobacco column in the channel during use, a third capacitor formed partly by an electrode plate lying permanently below the top surface of the tobacco column, and an electrical circuit which compares the value of the second capacitor with the sum of the values of the first and third capacitors and from which output signal can be obtained which reflects that comparison.

Abstract: A diverter valve assembly and priority control circuit for use in an ice distribution system having an ice source and first and second ice delivery stations, the valve assembly comprising a valve body having an inlet section communicable with the ice source, and first and second outlet sections communicable with the first and second delivery stations, respectively; the valve assembly including a valve body having a central valve chamber communicable with the inlet and outlet sections and having a rotatable valve element disposed therein; an electrically energized motor for selectively rotating the valve element whereby to selectively communicate ice being supplied from the ice source to selected of the ice delivery stations, and a control system for use with the valve assembly, whereby to assure against actuation of the valve element during the delivery of ice to the valve assembly.

Abstract: An automatically controlled liquid dispensing system including a reagent dispenser adapted to function as an intermediate container for dispensing relatively small controlled volumes of liquid to an associated receiving system in a continuous "demand" mode, this dispenser being indirectly monitored to be automatically and continually replenished after liquid is withdrawn therefrom, using a simple photoelectric liquid level monitor system including a fail-safe overflow control arrangement.

Abstract: A chemical replenisher system for supplying developer and fixer chemicals to a processor is disclosed. A developer and fixer tank are disposed side-by-side and coupled to the processor by way of hoses. A container-coded dispenser atop the tanks provides a substantially error-free arrangement for introducing the component chemicals into the tanks. A unique outline geometry is associated with each component container. By relating this geometry to a corresponding opening in a template of the dispenser, the introduction of the component chemicals is made error-free. The template openings also serve as guides for the containers. Uniquely designed knife assemblies are disposed below the template openings for piercing the tops of the sealed, chemical-filled containers upon inserting the containers into the template openings. Water is supplied under increased pressure as a mixing source is provided to each tank. A system of sensors provides low level alarm activation and automatic water shut-off.

Abstract: A wharf for receiving glowing coke, comprises an inclined receiving ramp which has a plurality of non-conducting areas and conductive plates interposed in the conductive areas at spaced locations. An electrical circuit control means is connected to each of the plates and provides a potential on the plates which will vary in accordance with the presence of coke over the plates. The electrical circuit also includes a control for effecting a control pulse in accordance with the potential sensed for carrying out a subsequent operation, such as the positioning or withdrawal of a rake element at the bottom of the wharf which supports the coke. With the method, by subjecting the conductive plates to an electrical potential, and by sensing the change in the potential, it is possible to regulate the amount of covering of the coke on the wharf.

Abstract: One or more pulsating streams of liquid material may be transformed into streams of essentially constant velocity with use of a counterweighted tundish that tilts in response to variations in liquid input. The dispensing system is particularly suited for use as a feeding source of liquid metal for continuous strip casting processes due to its ability to provide a constant low velocity teeming stream.

Abstract: A level control system involving both an apparatus and a method for a rotary feed hopper of the inverted, open-ended, truncated cone-type, wherein heavy paste-like viscous material which is fed into the large open upper end of the feed hopper is delivered or discharged through the small lower end of the hopper. A load meter in connected relation with the motor which drives the hopper senses the power required to drive the hopper and thus indirectly indicates the quantity of the material in the hopper, and consequently, the height or level of the material. When the load on the motor reaches a predetermined maximum the feed of material to the hopper is discontinued thus preventing overflow. When the load on the motor reaches a predetermined minimum the feed of material into the hopper is resumed.

Abstract: The regulator assembly comprises body member carried by a support and defining a cavity for detaining a pool of abrasive slurry. An overflow device is associated with the body member for establishing the upper level of a pool of abrasive slurry in the cavity. At least one flow-restrictive conduit component is secured at one end to the body member, communicates with the cavity at the lower end of the pool of abrasive slurry, and presents an outer end from which abrasive slurry is discharged. One of the above-indicated elements is movable whereby to selectively adjust the vertical distance between the plane of the upper level of the pool of abrasive slurry and the plane of the outer end of the conduit component.

Abstract: The regulator assembly comprises body member carried by a support and defining a cavity for detaining a pool of abrasive slurry. An overflow device is associated with the body member for establishing the upper level of a pool of abrasive slurry in the cavity. At least one flow-restrictive conduit component is secured at one end to the body member, communicates with the cavity at the lower end of the pool of abrasive slurry, and presents an outer end from which abrasive slurry is discharged. One of the above-indicated elements is movable whereby to selectively adjust the vertical distance between the plane of the upper level of the pool of abrasive slurry and the plane of the outer end of the conduit component.

Abstract: Mineral separating apparatus comprises a hydraulic classifier provided with an exterior wall, an open bottom sorting column within said exterior wall, and means for introducing a swirl of hydraulic medium in the sorting column. The exterior wall provides a quiescent zone between the bottom of the sorting column and further has a spigot connected to the quiescent zone for discharge of refuse. A launder section is disposed above said exterior wall and sorting column and is in communication therewith. First and second weirs in said launder section are located on opposite sides, respectively, of said exterior wall. The first weir is higher than the second weir to provide a hydraulic flow gradient therebetween.

Abstract: A device for transferring water from a standard five gallon water bottle to a dispenser spout, without the need for lifting the bottle and inverting it atop the dispenser, comprises a bottle pressurizing agent, ducting to carry water from the bottle to the dispenser and various control sensor and indicator means to control pressurant and water flow so that potable water from the dispenser is available on demand.

Abstract: A powder feeding apparatus in which a feed shoe, open at the top and bottom, is movable along a feed plate from a remote powder filling location to a position directly overlying a cavity into which the powder is to be fed. The apparatus includes a wire grid suspended in a horizontal plane near the bottom of the feed shoe and coupled to means for reciprocating it relative to the feed shoe to dispense fluent powdered material into the cavity. A photocell scanning system is provided for controlling the desired powder level and for detecting powder supply exhaustion.

Abstract: Apparatus for continuously measuring the bulk density of particulate material such as cut tobacco comprising a measuring column with level detection and density indicating means, a weighing conveyor and control means for driving the conveyor at speeds determined by signals from the level detecting means.

Abstract: A device for detecting the quantity of remaining developer comprises a non-magnetic container for magnetic developer formed with a lower discharge port, a magnet disposed outside and adjacent the bottom of the container for producing a magnetic attraction between the magnet and the magnetism of the developer within the container, a rotary screw roller or a rotary impeller for delivering the developer from the container through the discharge port thereof, a mechanism for causing relative movement of the magnet and the container away from each other against the magnetic attraction when the developer is below a predetermined quantity, and a switch operable by such relative movement.

Abstract: An automatic feeder for infusing solid solutes into liquid solvents at an adjustable, predetermined, controlled rate to maintain an adjustable, predetermined, controlled concentration of solute in a solvent reservoir, the feeder including means for adjustably controlling the rate of infusion of solute into a circulating, solvent stream within a chamber by controlling the quantity of solvent in the chamber as well as surface area of solute immersed in the solvent, means for feeding solute into the solvent in the chamber in a programmed fashion over a relatively long period of time without attendance, means for preventing accidental syphoning of all of the solvent from the feeder, and means for automatically breaking contact between the solute and the solvent in the feeder during periods of dissolution; the feeder comprising a housing having solvent inlet and outlet ports, a float valve for adjustably controlling the level of solvent circulating in the housing; and an anti-syphoning device on the float valve to

Abstract: A level control device for pickling, degreasing, nickel-plating baths or the like, comprising at least two baths of different specific gravities, wherein the two baths are joined to a connecting pipe and the connecting pipe runs into the bath of lower specific gravity just below the bath level so that level control is possible without pumps or float switches or the like.

Abstract: A single length of insulated, stranded steel cable extends vertically through a bin or other material container and functions as a radiating antenna for an electrical signal transmitter. The reactance of the antenna, which varies as a function of the level of material in the container adjacent the antenna, is inductively linked to an oscillator circuit in the transmitter. The transmitter's signal which is altered in frequency with changes in the antenna's reactance is combined with that of a constant frequency reference signal. The frequency of the resulting difference signal is employed to form a remote indication of the material level and to provide control information for automatically maintaining or varying material levels.