Abstract: Dental suction apparatus is a modular construction, made up of a plurality of modules joined fluid-tight side-by side. A main suction duct extends through all of the modules. At least two of the modules have connection for suction hoses each having a suction nozzle, holders being provided on the modules for holding the suction nozzles when not in use. At least one module has a filter chamber connected between a suction tube and the main suction duct. A removable filter unit in the filter chamber has a basket-shaped filter on a stem by means of which the filter can be removed through on opening closed by a hinged cover. A cap on the stem provides a seal for the filter chamber. Flow of air from the suction tube of each suction tube module to the main suction duct is controlled by a valve in the form of a bellows provided with a telescopic guide and with a control valve for controlling the expansion and contraction of the bellows by differential pressure.

Abstract: An X-ray film processor comprises a developing station, fixing station, rinsing station and drying station compactly arranged in a casing. Gear driven rollers transport the films continuously from a feed slot at the front of the casing, through the processing and drying stations and out of a discharge slot which faces forwardly but is above and back of the feed slot. The films are discharged onto an illuminated viewing screen located above the developing and fixing stations. The transport rollers are arranged in sets, one for each of the processing stations, which can be readily removed as a unit for cleaning, servicing or replacement. A system for continuously supplying fresh water to the rinsing station during operation prevents entry of contaminants back into the supply line. The drying station is located above the rinsing station and has a single heater and single fan so arranged in cooperation with the transport system as to dry both sides of the films.

Abstract: A hand held device for generating ultrasonic vibrations comprises an elongated tubular casing having therein a piezoelectric vibrator element and a generator that develops an electrical signal having a predetermined ultrasonic frequency that excites the piezoelectric vibrator element into ultrasonic vibration. A work tool protrudes from the casing and is vibrationally coupled to the piezoelectric vibrator element by a vibratory rod and the rod transmits the vibration from the piezoelectric vibrator element to the work tool. A cooling system is disposed within the casing and flows a cooling agent through the device to cool both the piezoelectric vibrator element and the generator and the cooling agent is discharged from the device in atomized form through an opening in the work tool.

Abstract: Apparatus for producing dry compressed air comprises a compressor which delivers air to a dry air storage tank through a cooling coil, a liquid separator comprising a housing having a cavity with a valve controlled tap opening at the bottom thereof, a screening filter and an adsorption filter connected in sequence. A pressure sensitive switch turns off the compressor when a predetermined pressure has built up in the storage tank. When delivery of air ceases, a valve control system opens the tap opening of the separator and second valve control system opens a valve to permit back flow of air from the dry air storage tank back through the adsorption filter to regenerate it and out of the tap opening if the moisture content of air in the dry air storage tank is above a predetermined level.

Abstract: A hand held device for generating ultrasonic vibrations comprises an elongate tubular casing having therein a piezoelectric vibratory element comprising an elongate bar of piezoelectric material and a generator that develops an electrical signal having a predetermined ultrasonic frequency that excites the piezoelectric vibratory element into ultrasonic vibration. The piezoelectric vibratory element also functions as the dielectric of a capacitor which constitutes part of the generator and which determines the ultrasonic frequency of the electrical signal output of the generator. A work tool protrudes from the casing and is vibrationally coupled to the piezoelectric vibrator element by a vibratory rod which transmits the vibrations from the piezoelectric vibratory element to the work tool.

Abstract: Apparatus for producing dry compressed air comprises a compressor, a separator to remove condensates, an adsorption filter to filter and dry the air and a storage tank. A valve for controlling reverse flow of air from the storage tank through the filter to the atmosphere to regenerate the adsorption filter when the compressor stops is controlled by a moisture sensitive device so that reverse flow is permitted only if the moisture control of the compressed air is above a predetermined value. The opening of a tap to discharge collected liquid from the separator is controlled by a pneumatically operated valve system so that no electrical control is required.