Abstract: A return filter for hydraulic fluids comprises a filter head attachable to a container for fluid, a filter pot arranged on one side of the filter head, a cover releasably arranged on the other side of the filter head, a filter element arranged so as to extend continuously through the filter head and the filter pot, at least one inlet formed on the filter head for the returning fluid, an air port formed on the filter head, and a ventilation filter inserted into this port. Filter head, filter pot and filter cover consist of plastic; a hose nipple integral with the filter head is formed at the inlet for the returning fluid. The air port is surrounded by a housing which is integral with the filter head and is closable by a cover carrying the ventilation filter. The walls of the housing are provided with slots which are open towards the cover. On the one hand, these slots make provision for air to pass through and, on the other hand, they allow the cover to be releasably clipped into the housing.

Abstract: A tap head for keg fittings comprises a sliding guide means containing an annular seal and a guideway for pushing the tap head onto the protruding rim of a plate of the keg fittings, wherein at least the sliding guide means of the tap head consists of spring elastic material and a projecting guide piece of the guideway engages under the rim of the plate. The modulus of elasticity of the material forming the sliding guide means and the geometry and the dimensions of the guide piece are determined such that the guide piece undergoes deformation at a predetermined gas pressure in the housing of the tap head and a gap for the release of excess gas pressure is formed between the plate and the annular seal.

Abstract: The invention relates to a machine for cutting tiles and comprising: a cutting member; a main abutment face of the stand suitable for coming into abutment against one of the sides of the tile; and a support mounted to slide perpendicularly to the cutting axis and supporting a first arm having a first face parallel to the cutting axis and suitable for bearing against the tile to be cut. A second arm is pivotally mounted on the first arm and includes a second bearing face for bearing against a tile to be cut, one of the two arms carrying an angular scale enabling the angle between the second face and the first face to be adjusted, and a device serves to lock relative pivoting between the two arms. The resulting tile cutting machine is versatile.

Abstract: A pipe extension for a filtering pot of a return filter has an outlet connection projecting from the filtering pot at its free end and a pipe secured to the outlet connection. An annular groove extending in circumferential direction is arranged at the outlet connection and an annular seal which does not protrude radially beyond the outer circumference of the outlet connection is inserted into the annular groove. Radially projecting, axially extending conical webs are provided at the outer circumference of the pipe connection in the region between the annular groove and the filtering pot and a pipe consisting of metal is pushed onto these webs, whereby the pushed-on pipe is expanded by the conically extending webs to achieve a secure seat. A bead reaching into the annular groove is introduced into the pushed-on pipe.

Abstract: A keyboard for a fully electronic, microcomputer-controlled commercial scale with call-up memory, in particular for self-service or quick-service purposes, comprises a keyboard consisting of a plurality of individual keys with actuating elements, whereby symbols and/or alphanumerical characters are assigned to the individual keys. The keyboard has a guide plate with a plurality of individual keys arranged at a certain grid distance from each other. The guide plate is provided over its entire surface with actuating elements for the individual keys.

Abstract: A boring tool comprises a rotating tool body, a tool slide transversely displaceable therein, a cutting plate arranged on the tool slide and a micrometer screw for adjusting the tool slide, this micrometer screw being mounted transversely to the axis of rotation of the boring tool so as to be rotatable and axially non-displaceable. The micrometer screw is mounted in the tool body at a distance from the tool slide and drives a drive slide displaceable transversely to the axis of rotation of the tool body. A transfer lever is pivotally mounted in the space between drive and tool slides and engages with one arm on the drive slide and with the other arm on the tool slide such that when the drive slide is displaced the tool slide is entrained in the opposite direction to the drive slide.

Abstract: A sunglass or eye protector molded from suitable optical material with inner and outer surfaces, both of which are noncircular in the horizontal direction and curved in the vertical meridian to provide substantially uniform thickness throughout.

Abstract: A chain for conveying slices of a food product comprises a series of interlocking U shaped links each having a crossbar and two legs. The legs are provided with loops which partially surround the crossbar of an adjacent link. Some of the loops have an endpiece which is bent through at least 270.degree. and is provided with an elongated tip which extends appreciably from and at substantially right angles to the plane of the chain. These tips penetrate the slices and ensure that they are carried by the chain without slippage. Preferably each endpiece having a tip is adjacent the outer portion of a leg so that the mechanism for lifting the slice from the chain can operate in the closest possible proximity to the tip in order to reduce bending of the slice.

Abstract: An integrated helmet system for presenting the wearer with visible images in which an outer helmet providing a surface on which the images are projected is adapted to be assembled on the frame of an inner helmet having a headband on which the frame is mounted for adjustment in front to back and side to side directions. A fixture adapted to be mounted on the frame provides a simulation of the images to be presented to the wearer on a surface positioned in front of the frame at a distance equal to the distance between the frame and the outer helmet viewing surface when the outer helmet was assembled on the frame, thus to permit the frame to be adjusted relative to the headband so that the outer helmet viewing surface is properly positioned with reference to the wearer's eyes when the outer helmet is assembled on the inner helmet.

Abstract: A metronome mechanism comprises a bearing frame with a web and two limbs protruding from the web, a winding stem carrying a spring housing, a ratchet wheel stem carrying a ratchet wheel and bearing bushes arranged on the limbs of the bearing frame for receiving the ends of winding and ratchet wheel stems. The bearing bushes are formed on two separate side parts which are adapted to be pushed onto the limbs of the U-shaped bearing frame and firmly locked on the limbs.

Abstract: The reading glasses are foldable, the hinge (4) having only a single joint axis (5). The optical part (1) of the eyeglasses is in one piece with the nosepiece (2) and consists of a synthetic material. I.e., frameless eyeglasses whose foldable earpieces (9-11) consist of a metal are obtained. The hinge (4-7) consists of a metal and lies embedded in the nosepiece (2). The latter is provided with recesses (14) in which the folded earpieces (9-11) lie. The eyeglasses can be produced inexpensively and may be folded up with small dimensions.

Abstract: A device for selective detection of gas, enabling a first gas to be detected relative to a second gas, the device having a solid state sensor provided with an insulating substrate having a first face and a second face, a heater element deposited on the first face of said substrate, metal electrodes deposited on the second face of said substrate, and a semiconductor layer formed on said electrode and over the second face of said substrate. Detection is performed by simultaneously determining a voltage U representative of the resistance of the semiconductor element of the solid state sensor and the voltage difference S between a voltage representative of the temperature of the heater element of said solid state sensor and a voltage representative of the temperature of a heater element of a reference sensor, the voltage U and the voltage difference S each being compared with a different and predetermined threshold voltage in order to enable selective detection of gas.

Abstract: A column of liquid is formed in a conduit for such liquid, of which flow-off amount gives then between two level measuring probes a constant value. This constant value is compared with the indicated value of a flow meter arranged in the conduit regarding the conformity in order to detect if the value indicated by the flow meter lies within a tolerance range or not. In the latter case, the error indication of the flow meter is too large and the liquid conduit is shut off. This controlling is made in arbitrary intervals automatically by the apparatus, whereby the interval is set by the speed with which the liquid column is completed.

Abstract: Novel squarylium dyestuffs are formed by condensing one molecular equivalent of squaric acid with two molecular equivalents of a heterocyclic intermediate of the formula ##STR1## in which X is an optionally substituted ethylene or o-phenylene group; Y is an optionally substituted methylene or imino group, oxygen, sulfur, selenium or (if X is ethylene) a direct bond; and R.sub.1 through R.sub.5 are various substituents or (except for R.sub.2 and R.sub.5) hydrogen. A preferred class of dyestuffs are those formed from intermediates in which Y is methylene or a direct bond, the former including 7-acylaminotetrahydroquinolines and the latter including 6-acylaminoindolines. Thus, two molecular equivalents of each of 1-methyl-7-acetamido-1,2,3,4-tetrahydroquinoline and 6-acetamido-1,2,3, 3-tetramethylindoline were condensed with one molecular equivalent of squaric acid to produce respective dyes each having an absorption maximum substantially coincident with the ruby-laser wavelength of 694 nm.

Abstract: A protective headgear assembly for use by personnel required to use sighting devices in which a close-fitting helmet carries impact-resistant, energy-absorbing material over that portion covering the wearer's nape, crown and side head portions over the ears but which is free of such material in the frontal portion which covers the wearer's forehead to permit the wearer to bring his eye into close proximity with a sighting device. A separable body of impact-resisant, energy-absorbing material is removably positioned over the helmet frontal portion by detachable fasteners which secure the body to a soft cover on the helmet where the wearer desires only bump protection or by a separable part of a two-part ballistic shell attached to the helmet where the wearer desires both bump and ballistic protection. The helmet can be adapted for use by non-sighter personnel by using either a unitary soft cover or a unitary ballistic shell to position the separable body on the helmet.

Abstract: A linear electromagnetic drive means comprises a coil with a controllable electric current flowing therethrough, magnetic poles assigned to the coil and an axially displaceable core biased by at least one spring in the region of the coil and the magnetic poles, whereby the core serves to control a control element by means of its displacement movement triggered by the electric current. The spring biasing the displaceable core has the design of a tube in which slits extending essentially radially are formed with flexible tube segments lying therebetween.

Abstract: Apparatus for filtering solid particles suspended in a gas includes a housing divided by a plate into an upper clean gas chamber and a lower polluted gas chamber. Depending filter elements are secured to apertures in the plate. Polluted gas flows to a distributor, in the lower chamber below the filter elements, to which is coupled a plurality of vertically disposed pipes extending upwardly past the filter elements to outlets disposed in the vicinity of the plate. The upward discharge from these outlets is then deflected downwardly past the filter elements.

Abstract: A valve 1 for controlling a fluid medium flowing under pressure comprises an inlet opening 6 and an outlet opening 12 as well as an inlet member 4 having the medium flowing axially therethrough and a sleeve-shaped control member 13 axially displaceable between a closed and an open position relative to the inlet member 4, whereby in the closed position the outlet opening 12 is closed and in the open position the outlet opening 12 is opened. In addition, a first radially projecting, elastic sealing ring 24b is provided and a first annular sealing edge 25 which is adapted to be pressed sealingly against the first sealing ring 24b in a closed position of the control member 13.