Abstract: Apparatus for making a tubular plastic sheath having one or more imperforate panels around the periphery of the sheath with intervening plastic net connecting the imperforate panels, the apparatus including an extruder, perforating means and stretching means, the improvement being extrusion means to form bands of different thickness asbout the sheath the perforation means being positioned such as to perforate only bands of one thickness.

Abstract: A gaseous fuel injection unit for internal combustion engines fed with gaseous fuel such as liquefied petroleum gas or methane, comprises at least one volumetric measuring device (7) arranged to feed during each engine cycle a determined volume related to the piston displacement, and into which there is fed and respectively discharged that quantity of gaseous fuel complying with the required mixture ratio of fuel to air drawn in by the engine during each cycle. A control unit (5) senses operating pressures along the intake pipe system (1), namely in the injection zone (19) and in the zone (18) downstream of the throttle valve (2), in order to control an expander unit (10, 11) which feeds the gaseous fuel to the volumetric measuring device (7) at a pressure equal to the sum of the absolute values of the two pressures at the aforesaid points, and to control said volumetric measuring device.

Abstract: A zoom lens in which two pairs of optical elements of the lens are each movable simultaneously relative to each other to attain desired magnification while maintaining the image surface of the lens system substantially fixed.A common body supporting both sets of lens elements can be moved if required to maintain the focal plane of the lens system fixed. The need for moving the body may arise where the movement of the lens elements causes a shift or displacement of the focal plane of the zoom lens.

Abstract: In accordance with the invention, the armature (17) of the windscreen wiper blade is caused to rotate in an alternating manner by a blade support arm (1) by means of a rocker arm (6) articulated on the arm (1) and on a rocker arm control member (16) which is displaced with respect to the arm (1). The armature (17) is connected to the rocker arm (6) by means of an adapter (24) which is mounted in a detachable manner on the armature (17) by resilient locking and on which the rocker arm (6) is pivotably mounted about an axis of rotation (11) disposed below the armature (17) with respect to the pivoting axis (7) of the rocker arm (6) on the arm (1). To be used to equip automobile vehicles.

Abstract: A windscreen wiper device, in particular for a single blade or double blade assembly, comprises for at least one of the blades, firstly a main wiper arm articulated at one end on a hinge pin, this main wiper arm being provided at its other end with a rocker and, secondly, an auxiliary arm articulated at one end on a portion of the rocker and at its other end, on a clevis pin substantially parallel to the hinge pin of the main wiper arm. The clevis pin of the auxiliary arm is displaced in relation to the geometrical axis of rotation of its clevis joint, along a central longitudinal direction of this arm by a distance sufficient to allow the assembly of the main wiper arm and of the auxiliary arm to be raised in the normal way by removing it from the surface to be wiped by rotation around the said clevis and hinge pin.

Abstract: A rapid and reliable method is proposed for the quantitative determination of the individual free and acetylated polyamines, i.e. spermine, spermidine, putrescine, acetylspermine, N.sup.1 - and N.sup.8 -acetylspermidines and acetylputrescine in the body fluid of a patient suffering cancer or other diseases to facilitate diagnosis and therapeutic treatment. The method comprises subjecting the aqueous fluid to several enzymatic oxidative decomposition reactions of the polyamines in sequence or in combination by use of the 4 enzymes, i.e. polyamine oxidase AT-1, polyamine oxidase PC-3, putrescine oxidase and acetylputrescine oxidase, and determining, preferably photometrically, the amount of hydrogen peroxide formed as a byproduct in each of the reaction steps followed by setting up a set of simultaneous equations to give the respective amounts of the individual polyamines as a function of the amounts of the hydrogen peroxide formed in the reaction steps and solving the simultaneous equations.

Abstract: A bi-polar discharger for a coaxial conducting cable is formed by threading rod elements into the ends of a central passage through an internal electrode so as to be electrically conductive therewith. A casing around the internal electrode comprises a cylindrical outer electrode closed at each end by a bead of glass or ceramic which is fitted within an outer metal ring and the casing is sealed with a controlled atmosphere of an inert gas at low pressure by sealing of the outer rings to the cylindrical external electrode and sealing of the rod elements within the beads.

Abstract: A device for selecting the tools of the tool carrying head of tire removal machines in general comprises a hydraulic cylinder-piston unit (17) arranged to cause a tool carrying head (6, 7) to rotate, and connected in parallel with a hydraulic cylinder-piston unit (11) which causes a bar (1) on which the head (6, 7) is rotatably mounted to swivel in a vertical plane. A sequence valve (31) is provided in that pipe connecting together the cylinder-piston units (11), (17) through which the oil passes for moving the bar (1) into its rest position, and a free-wheeling linkage (20, 23, 24) is disposed between the bar (1) and head (6, 7) to enable the head (6, 7) to rotate in only one direction, and is associated with a positioning element (25) which fixes said head in position at every half revolution.

Abstract: Automatically actuated seal constituted of a profile molding connected to a movable panel in a frame, a sill, or a portion of the casing of the frame, and having an elongated sealing element, mounted in a groove of the profile molding and able to be displaced between a retracted position and a projecting sealing position under the effect of an actuating device lodged in the profile molding and having a sealing joint with several legs, one of which is connected to the sealing element and another to the profile molding.

Abstract: A high voltage generator 1 for an electrostatic dust precipitator 2 comprises a low voltage oscillator 6, operating from a low voltage continuous source, such as a car battery, which supplies a current chopper 7. The output from the chopper 7 is fed to the primary winding 9 of an induction coil 10. The secondary winding 11 of the coil 10 is connected to one of a metal surface 3 of the dust precipitator to apply a high potential difference between the metal surfaces 3,4 to precipitate dust. Preferably the metal surface 3 is connected to the secondary winding 11 via a high voltage diode.

Abstract: A windscreen wiper device comprises a drive crank 6 mounted fast on a drive shaft 7 of a drive motor, a connecting rod 5 pivotally mounted on said drive crank by means of a crank pin means, and a windscreen wiper blade support arm 2 connected to said connecting rod 5 so that rotation of said drive crank 6 by said drive motor rotating in a first direction sweeps said support arm 2 through a predetermined arc.

Abstract: Apparatus for making a continuous tubular structure of helically wound interlocked metal strip. The metal strip is fed to forming rollers, from a reel of the strip and which are mounted on the same side of a circular plate which is rotated about a horizontal axis to wind the strip, which is shaped by the rollers, prior to winding, around a mandrel. A plurality of pressure rollers positioned around the mandrel interlock and compress the profiled strip. The mandrel is driven in a direction opposite to the direction of rotation of the plate. A rotatable support assembly downstream of the mandrel tightens and clamps the windings. A longitudinal extraction mechanism downstream from the support assembly restrains the tubular structure from rotating and feeds the formed structure to a receiving reel.

Abstract: A perforated structure of expanded material, including at least one solid unstretched strip (4) parallel to the direction of expansion and of a length less than the length of the expanded region. The expanded region is formed with a tool that simultaneously cuts or perforates and expands the material.

Abstract: An external appliance to be worn on the trunk of a person compensates for lack of tone, metricity and for sensitivity in the vertebral column and trunk. The appliance comprises upper and lower composite structures respectively surrounding the hemithoracic regions and the pelvis and abdomen. The appliance takes into account differential variations in trunk diameter and provides a preferential link between the scapular muscles and pelvic motor muscles of the user.

Abstract: Apparatus for determining sedimentation rates including a first support means having a plurality of tubes, held vertically and spaced, and a second support means having a plurality of tubes, of larger diameter than the tubes mounted on the first support means, and each able to receive a blood sample, the tubes being vertical and spaced on the said second support means, and a single suction device mounted at the upper end of the first support means, the support means being movable with respect to each other between a first position in which the tubes of the first support means are separated from the tubes of the second support means, a second position in which the lower ends of the tubes of the first support means dip into the tubes of the second support means, and a third position in which the sedimentation of the red blood corpuscles takes place.

Abstract: The invention refers to a method and a device for the manufacture of flexible tubular bodies in which one or more profiled strands are deformed spirally in a permanent manner before proceeding to winding it or them spirally in order to form a cylindrical carcass, by making the profiled strand pass over two pulleys in succession.The profiled strand is wound on the flat round each of the pulleys, the axes of the two pulleys being angularly offset so as to cause a permanent twist in the length of profiled strand situated between the said two pulleys.

Abstract: The invention provides carbon fibers having mechanical properties equival to or even better than those of the polyacrylonitrile-based carbon fibers from a bituminous material, e.g. coal tar pitch, as the starting material. The starting pitch is first partially hydrogenated in tetrahydroquinoline under specific conditions followed by a heat treatment to give a pitch composition suitable for spinning which can be characterized by several parameters including the proportions of the carbons and hydrogens having different chemical shifts in the NMR analysis. The pitch composition for spinning is then subjected to spinning under specific conditions including the temperature condition for controlling the viscosity behavior of the molten pitch composition determined by use of the Andrade's equation and the pitch filament is then infusibilized in an oxidative atmosphere and carbonized in an inert atmosphere into carbon fibers having a tensile strength of at least 200 kg/mm.sup.

Abstract: In accordance with the invention, an iterative search operation for the optimum value .theta..sub.opt of the angle of advance is carried out by adding periodically an angle of advance increment .DELTA..theta. to the instantaneous angle of advance .theta..sub.o, and by detecting the instantaneous speeds N.sub.1t and N.sub.2t which correspond to the angles of advance .theta..sub.o and .theta..sub.o +.DELTA..theta., and by determining the direction of variation .DELTA.N of the engine speed so as to correct the angle of advance .theta..sub.o such that the variation .DELTA.N is as low as possible, or even zero, such that the angle of advance .theta..sub.o is kept in the vicinity of its optimum value .theta..sub.opt. In the case of transitory states, a "floating cartography" is superposed and takes into account a curve of the advance as a function of the engine speed. The invention may be used for controlling the ignition advance of the engines of motor vehicles.

Abstract: The invention concerns agriculture. It relates in particular to an agricultural greenhouse which comprises a metallic frame supporting transparent covering elements, wherein said covering elements are formed of panels made of transparent plastic material mounted flatwise and having undulations which are parallel to the metallic frame members, said undulations each having two asymmetrical slopes, with the greater slope being directed southward, the angle .alpha. between the greater slope and the horizontal being about 25.degree. to 35.degree., and the angle .beta. between the smaller slope of each undulation and the horizontal being about 55.degree. to 65.degree., and at least one of said covering elements being mounted pivotally around a horizontal axis at its free edge directed southward, with control means being provided for causing said panel or panels of the movable covering to pivot at a predetermined angle.

Abstract: A windscreen wiper system comprising a frame, a motor driven reducer, a bar drive mechanism and two windscreen wipers one of which has two controlled movements, one for sweeping, the other for extension-retraction. Said system comprises three coaxial shafts journalled to the frame, the arms of said two windscreen wipers are carried by two of said shafts which drive them with sweeping movements in the same direction, the extension-retraction is controlled from the third shaft driven with a reciprocating movement of the same frequency as the other two but in the opposite direction and said drive mechanism comprises three rocking levers fixed respectively to each of said coaxial shafts.