Abstract: A shock end loop for use with a shock absorber having a shaft is provided. A shock end loop according to various aspects of the present technology may include a body portion adapted for engagement with a threaded end of the shaft. The shock end loop may also include a neck portion coupled to the body portion and extending upward therefrom and adapted for engagement with the shaft for firmly securing and supporting the shaft to counteract a side load or bending torque that is exerted on the shaft by the vehicle.

Abstract: A display device includes a display panel including a first surface, and a shock absorber disposed on the first surface of the display panel, the shock absorber having a second surface thereof facing the first surface, wherein, in a first cross-section taken in a thickness direction of the shock absorber, the shock absorber includes an edge surface having a first point closest to the first surface and a second point farthest from the first surface, on an outer surface of the shock absorber, and based on an imaginary line extending between the first and second surfaces, a first distance between the imaginary line and the first point is less than a second distance between the imaginary line and the second point.

Abstract: Universal mechanical isolator that effectively decouples a vibration sensitive device such as a microphone from a support to thereby isolate the vibration sensitive device from mechanical vibrations.

Abstract: A seal assembly for a piston rod including an external seal and an internal seal. The external seal is adapted to be placed on a piston rod facing an external environment, the internal seal is adapted to be placed on the rod facing the cylinder associated to the piston. The external and internal seals define in cooperation with each other a chamber for the containment of barrier fluid. Such chamber has an inlet for the intake of barrier fluid and an outlet for the exit of barrier fluid. The assembly also comprises a recirculation circuit for the barrier fluid, which is placed in fluid communication with the inlet and the outlet to recirculate the barrier fluid from the outlet back to the inlet and a pressurizer device configured to be installed coaxially with the piston rod providing the chamber with a positive pressure with respect to the process environment.

Abstract: A piston and cylinder type damper is provided, with a cylinder (11) having a piston assembly (15) mounted for reciprocal movement therein. The piston assembly (15) divides the cylinder (11) into two separate chambers (12a, 12b), with a restricted flow path (30, 31) for passage therebetween of damping fluid contained within the cylinder. A piston rod (13) is mounted for reciprocal movement with respect to the cylinder (11) and acts via a first one of the chambers (12a) on the piston assembly (15) in a first direction. A seal assembly (17) is provided for sealing between the piston rod (13) and the cylinder (11) in order to retain damping fluid in the first chamber (12a). The seal assembly (17) is movable axially with respect to the cylinder (11), with the cylinder further including a centering device (24) for assisting alignment of the seal assembly (17).

Abstract: A system includes a plurality of inflation balls configured to be launched and a connection mechanism. The plurality of inflation balls are configured to modularly inflate with respect to one another to create a combined modular volume. The connection mechanism is configured to allow the modular inflation of the plurality of inflation balls with respect to one another.

Abstract: A machine and method to produce structural elements for the building trade made of cement material with one or more inserts made of polymer material. The machine comprises at least a molding member, a loading unit for loading the inserts and a depositing member to deposit the cement material. The molding member is open at the upper part and the loading unit and the depositing member are selectively positionable above the molding member in order to load and deposit from above, respectively, the inserts and the cement material into the molding member, in order to achieve the structural elements.

Abstract: A spiral air pressure spring designed by the invention solves the technical problems of complex structure and low compressive strength in the current gas springs. The spiral air pressure spring comprises a spring body, and is characterized in that the spring body is formed by an air column having a pressure air containing cavity, the air column is spiral, and at least one vent hole communicated with the containing cavity is arranged on the air column.

Abstract: A shockproof device for a container data center (CDC) includes an impact detection module and a shockproof module. The impact detection module is received in or attached on the CDC and detects an impact force of the CDC. The shockproof module is electrically connected to the impact detection module and includes a plurality of pressure pipes, and each of the pressure pipes having a distal end mounted on the CDC. The shockproof module generates a predetermined pressure using each of the pressure pipes according to the impact force, and the pressure is transmitted to the distal ends of the pressure pipes and forms a resisting force to counteract the impact force.

Abstract: A strut assembly forming an upper part of a cylinder joined to a wheel is joined to a vehicle body via an insulator and joining member, an airtight chamber space is formed by a strut cover joined to a spring body joined to a damper rod drawn from the cylinder, whereby a CDC type damper with the chamber space of which air pressure is controlled in order to vary the movement characteristic depending on movement of a tire and a damper joined to an inner space of the spring body has an urethane made damper guider having dug air channels where air moves even in a state where the damper is in close contact with the damper rod.

Abstract: The present invention is directed to a method of treating a reinforcement cord, comprising the steps of A) atomizing a mixture of at least one polymerizable monomer, a halogenated saturated hydrocarbon, and a carrier gas to form an atomized mixture; B) generating an atmospheric pressure plasma from the atomized mixture; and C) exposing the reinforcement cord to the atmospheric pressure plasma under conditions suitable to form a polymer strongly bonded to the tire cord and capable of bonding to rubber.

Abstract: A monotube shock absorber assembly includes a housing (20), a gas cup (32) slidably disposed in the interior (28) of the housing (20), and a piston (42) slidably disposed in the interior (28) of the housing (20) to define an oil compression chamber (48) between the piston (42) and the gas cup (32). A cushion (58) engages one of the piston (42) and the gas cup (32) and extends axially into the oil compression chamber (48) for intermittent contact with the other of the piston (42) and the gas cup (32). The cushion (58) is a resilient material and deforms in response to the cushion (58) contacting the other of the piston (42) and the gas cup (32). In a preferred embodiment, the cushion (58) defines a central opening (60) for decreasing the axial stiffness of the cushion (58) and engages the gas cup (32) for intermittent contact with the piston (42).

Abstract: The present invention provides a shock absorbing apparatus for an aircraft seat, that attenuates shock to passengers and crews. The apparatus includes; an airbag 11 being expanded in a plate shape in a state of less than maximum expansion; an upper flat plate 12 arranged on one side of the airbag 11; a lower flat plate 13 arranged on another side of the airbag 11; a gas supply device 15 for supplying a gas to the airbag 11; and a detector sending a signal to activate the gas supply device 15 by a preset condition. The shock is absorbed by expanding the airbag 11 before the shock is applied to the passenger.

Abstract: A spring wall for securement between associated end members for forming an associated gas spring assembly includes a first wall portion that extends axially along a longitudinal axis and circumferentially thereabout. The first wall portion is formed from an unreinforced elastomeric material, and the first wall portion has a first nominal stiffness value. A second wall portion extends along the longitudinal axis and circumferentially thereabout. The second wall portion is disposed in longitudinal relation to the first wall portion and has a second nominal stiffness value that is different from the first nominal stiffness value of the first wall portion such that a non-constant stiffness profile is established along a longitudinal length of the spring wall. A gas spring and a gas spring and reservoir assembly utilizing such a spring wall as well as a method of manufacturing a gas spring are also included.

Abstract: A gas spring is intended to permanently maintain the sealing performance of a lip in a dust seal without being affected by pressure from a gas sealed inside the spring. A rod body is operates in conjunction with a cylinder body with a gas of a predetermined pressure sealed inside the cylinder body. The rod body is movable into and out of the cylinder body. A rod guide is penetrated by the rod body at a shaft core portion inside a head end portion of the cylinder body. A dust seal has with a lip in sliding contact with an outer circumference of the rod body. A sealed end portion of the cylinder body is in contact with an outer end of the rod guide inside the cylinder body. The dust seal is integrally incorporated at the outer end portion of the rod guide.

Abstract: A device for springing a mass including a fluid spring and a frame, in which the fluid spring is arranged between the mass and the frame in such a way that the mass is mounted on the frame in a sprung and/or damped manner. An add-on-fluid volume device for providing an additional fluid volume for the fluid spring includes at least two fluid volume chambers that can be fluidically connected to one another and which have a common, displaceable chamber wall.

Abstract: Impact-attenuating elements, e.g., for use in footwear or other foot-receiving device products, may include: (a) a base member, such as a fluid-tight and/or other fluid-filled or fluid-containing enclosure element; (b) a support element integrally and contiguously formed in a surface of the base member; and/or (c) a spring device engaged with the support element. The support element and its corresponding spring device (if any) may include a non-planar surface (e.g., substantially parabolic shaped, cylindrically shaped, etc.) that extends in a direction into the base member and toward its opposite surface. The support element and its corresponding spring device (if any) also may include reinforcing structure(s), such as raised ribs extending along a surface of the support element and/or spring device.

Abstract: A strut assembly forming an upper part of a cylinder joined to a wheel is joined to a vehicle body via an insulator and joining member, an airtight chamber space is formed by a strut cover joined to a spring body joined to a damper rod drawn from the cylinder, whereby a CDC type damper with the chamber space of which air pressure is controlled in order to vary the movement characteristic depending on movement of a tire and a damper joined to an inner space of the spring body has an urethane made damper guider having dug air channels where air moves even in a state where the damper is in close contact with the damper rod.

Abstract: There is provided a vibration isolator capable of, (1) vibration isolation performance for ground motion disturbance: vibration isolation for floor vibration, and (2) vibration control performance for direct acting disturbance: suppression of swing due to driving reaction force caused by stage movement, significantly improving the above (2), i.e., the vibration control performance, with keeping the above (1), i.e., the vibration isolation performance, at a high level.

Abstract: A moderation element may be incorporated into straps, handles, or other devices to moderate forces. As an example, a moderation element may include a housing and a fluid-filled chamber. The housing has an expandable configuration and defines an interior void. The housing also defines a pair of opposing compression surfaces within the interior void, with the compression surfaces being located to move toward each other when the housing expands. The chamber is located within the housing and between the compression surfaces.

Abstract: The present invention relates to a home-bar door apparatus for a refrigerator. The home-bar door apparatus includes a home-bar door (30) that selectively opens or closes an opening (22) formed in a home-bar frame (20) and has rotational shafts (34) protruding at both sides of a lower portion thereof and a catching step (35) formed along a lower end thereof, dampers (36) that is installed on a rear face of the home-bar frame (20) and controls an opening/closing speed of the home-bar door (30) by receiving the rotational shafts (34) of the home-bar door (30) therein so that the rotational shafts (34) of the home-bar door (30) can be relatively rotated, and a stop rib (26) that is formed laterally along a lower end of a groove (23) formed around a periphery of the opening (22) and has stopping steps (27) formed at positions corresponding to both ends of a catching step (35) of the home-bar door (30) so that the catching step (35) can be caught by the stopping steps.

Abstract: The disclosed changing station may support a small person, such as a baby. The station may comprise a platform, a support structure, and a mounting structure. The platform may be rotatable from a vertical storage position to a horizontal use position along a rotational axis. The support structure may have a rotatable support member that rotates along the rotational axis.

Abstract: An impact attenuation bag has a height-reducing structure in the form of an internal rib that draws the upper and lower surfaces of the bag closer together, reducing the overall height of the bag when inflated as compared with the same bag in the absence of the rib. This gives the bag a flatter resting shape that provides significant performance enhancement by increasing the initial ground contact area and lowering the vehicle assembly center of gravity. As a result, the moment arm is reduced making the payload less likely to roll over. The rib may be a fabric sheet or cord laced in a criss-cross or other lacing pattern that extends from the top of the bag to the bottom.

Abstract: A high performance pneumatic spring apparatus is provided without increasing the sizes of the apparatus. The pneumatic spring apparatuses KB1-KB4 are provided with gas chambers AR filled with a gas at a prescribed pressure. The gas chamber AR is provided with an adjustment apparatus SW for adjusting a temperature change due to the capacity change of the gas chamber AR.

Abstract: An air spring assembly including a first end member having a peripheral edge, a second end member in spaced relation to the first end member, and a flexible sleeve secured between the first and second end members at least partially defining a spring chamber. A label is formed from sheet material and includes a first portion coated with adhesive and a second portion spaced from the first portion that includes a plurality of indicia. The label is disposed along the first end member with the first adhesive portion secured thereto and the second portion extending outwardly beyond the peripheral edge. A method is also disclosed.

Abstract: The invention relates to an arrangement in a pressing tool for braking the return movement of pistons/piston rods (D1) of gas-filled springs (D) and thereby also of a sheet metal holder (B) supported thereon after pressing has been performed. The invention is characterised in that each gas-filled spring device (D) is designed with a separate brake cylinder part (E) and brake piston part (F), in which the brake cylinder part (E) is situated adjoining the outer end of the gas-filled spring (D) and in which the brake piston part (F) is situated adjoining the inner end of the piston rod (D1).

Abstract: A composite material is provided that includes an array of machine elements disposed within a matrix material. Each machine element includes a cross-section defining an internal space that is filled with a viscous fluid. Preferably, the machine elements are provided in complementary pairs of tubular members, with the internal spaces of the tubular members communicating with one another. When subjected to a predetermined force, the cross-sections of the tubular members change shape, changing the volume of the internal spaces, and causing fluid to flow into or out of the internal spaces. Preferably, under the predetermined force, one tubular member increases in volume and the other tubular member simultaneously decreases in volume, thereby causing fluid to flow between the tubular elements to dissipate energy from the predetermined force.

Abstract: A pneumatic spring pot has a pot wall and a bottom connected to the pot wall and also an annular flange connected, opposite the bottom, to the pot wall and intended for the fastening of, for example, a pneumatic spring concertina, the annular flange having a smaller diameter than the largest diameter of the pot wall. The bottom, pot wall and annular flange are formed in one piece with one another by sheet metal forming from a sheet part, in such a way that the annular flange is formed from the outer edge region of the sheet bar. Furthermore, a method for producing the pneumatic spring pot is described.

Abstract: A machine spindle includes a rotatable casing in which a clamping device is mounted. The clamping device includes a drawbar for securing a cutting tool. The drawbar is axially displaced by a gas spring which includes a chamber in which a lubricant-containing gas medium is confined. A piston includes a head slidable within a cylindrical upper portion of the chamber, and a rod extending through a lower portion of the chamber and connected to the drawbar. The lower portion of the chamber is non-cylindrical and widens upwardly to promote the upward travel of lubricant toward the piston and upper seals under the effects of centrifugal force during rotation of the spindle.

Abstract: An air damper comprises a cylinder having first and second openings at both ends, a piston that moves in the cylinder, a piston rod coupled to the piston and moving in and out at the first opening of the cylinder; and a cap positioned at the second opening of the cylinder. The piston rod has a continuous outer wall and an opening extending along the longitudinal axis of the rod. The cross-sectional view of the piston rod taken along a plane perpendicular to the longitudinal axis is an inverse U-shape, an inverse V-shape, a C-shape, or the like. The piston rod has a fixing ring at the leading end. A plane containing the opening is perpendicular to a plane defined by the fixing ring. The piston rod is fixed to a glove box so that the opening faces down.

Abstract: In an air-type shock absorber, a piston is sealing situated in a cylinder chamber. A vacuum state occurs in a piston bearing side of the cylinder chamber when a piston is pushed. Also, an air reservoir is provided at a side opposite to the piston bearing to have a sealed structure, so that a force of absorbing a shock can be increased to have the same effect as in an oil-type shock absorber. The shock absorber can be used not only at a place requiring cleanness but also in adverse environment in which the shock absorber is exposed to water or coolant, and durability of the shock absorber is also improved.

Abstract: An apparatus for attenuating shock loads includes a flexible, non-rigid outer impervious envelope. The envelope is formed from a high strain resistance material. An inner, pervious baffle extends across the envelope between the first and second sides. The inner baffle is also a flexible, non-rigid material of high strain resistance. The envelope is inflated with gas at a superatmospheric pressure. An impact on one side of the structure will compress that side, increasing the pressure of the gas between that side and the baffle. The gas will then flow through the pervious baffle to the other side, dissipating energy, spreading the load over the second side of the envelope and causing a time delay in the build-up of pressure on the second side. In preferred embodiments of the invention, there are plural, parallel baffles in the envelope to provide a multi-stage energy dissipation.

Abstract: A variable spring constant type damper filed with visco fluid which has a great damping effect over a wide frequency band from a low frequency band to a high frequency band and to suppress a resonance magnification at a resonance frequency of a supported body. It is such constituted that the changes are given to a flexible portion (9) made of an elastic body like rubber connecting the flexible portion (9) and a cylindrical portion (8), whereby a spring constant is allowed to depend upon an amplitude.

Abstract: An actuation arrangement for movable components on vehicles, particularly for trunk lids or hoods, doors, vehicle tops and top covers, including at least one hydraulic cylinder (1) pivotably coupled to a cylindrical pivot pin (11) on the vehicle and/or on the movable vehicle component, and having at least one line (1) for the pressure medium in at least one working chamber (6, 9) of the hydraulic cylinder.

Abstract: An air spring defines a longitudinal axis and includes a first end member in the form of a cover and a second end member in the form of a roll-off piston at a distance from the first end member. A flexible resilient member is clamped between the first and second end members so as to permit the first and second end members to move toward each other in the direction of the longitudinal axis and the distance between the end members changes during the operation of the air spring. An elevation sensor includes an electrically conductive helix arranged in the direction of the longitudinal axis. The helix has a plurality of turns and is arranged in the air spring so that the helix changes in length when the end members move towards each other in the direction of the longitudinal axis. The first and second end members and the flexible resilient member conjointly defining an interior space.

Abstract: An apparatus for attenuating shock loads includes a flexible, non-rigid outer impervious envelope. The envelope is formed from a high strain resistance material. An inner, pervious baffle extends across the envelope between the first and second sides. The inner baffle is also a flexible, non-rigid material of high strain resistance. The envelope is inflated with gas at a superatmospheric pressure. An impact on one side of the structure will compress that side, increasing the pressure of the gas between that side and the baffle. The gas will then flow through the pervious baffle to the other side, dissipating energy, spreading the load over the second side of the envelope and causing a time delay in the build-up of pressure on the second side. In preferred embodiments of the invention, there are plural, parallel baffles in the envelope to provide a multi-stage energy dissipation.

Abstract: The invention relates to an arrangement for a gas spring. The arrangement comprises a cylinder (1). At its one end, this is delimited by a fixed end wall (2), and at its other end there is a first guide (3) sealed against the inner wall of the cylinder (1) and against a piston rod (4) capable of axial movement within the cylinder (1). The piston rod (4) has a second guide (8) mounted in such a way as to be capable of sliding against the inner wall. An annular piston (9) sealed against the inner wall and against the piston rod (4) is mounted on the piston rod (4) between the guides (3; 8) in such a way that it is free to slide. This divides the inner space of the cylinder (1) into a first and a second part space (12; 13). In an initial position, in which the gas spring is unaffected, there is present in the first part space (12) a pressure which is greater than the pressure present in the second part space (13).

Abstract: A shock absorber has a cylinder with a piston and piston rod arrangement in the cylinder. Working medium can be guided in different flow paths via shim stacks for the purpose of obtaining different dampings based on the position of the piston. The piston arrangement can have a piston supporting shim stacks. One or more further shim stacks are arranged in a unit which is separate from the cylinder. In at least one of the shock absorber strokes, the working medium can be conveyed via the shim stack(s) in the unit separate from the cylinder.

Abstract: Disclosed is a vibration damping and isolation apparatus having a passive damping mechanism. The passive damping mechanism includes an outer tubular member and an inner member. The inner and outer members are linearly movable relative to one another upon application of forces to the damping apparatus. The inner member is spaced from the outer member by a fluid shear gap that is filled with a viscous fluid. Fluid pressure of the viscous fluid remains constant while the viscous fluid dissipates the forces by direct fluid shear upon relative linear movement of the outer and inner members.

Abstract: The invention relates to a degressive gas spring. This has two cylinder-piston units (1, 2), one of which is selected as a working spring (1) and the other as a slave spring (2), the cylinders (1a; 2b) and the ends of the piston rods (1b; 2b) of which are mutually operatively connected so that compression of the working spring (1) also brings about simultaneous compression of the slave spring (2). The piston rod (1b; 2b) of each spring unit (1; 2) is mounted in an end wall (1c; 2c) in such a way as to be capable of sliding and supports a piston (1h; 2h). The axial position of this in the cylinder (1a; 2a) determines the volume of an enclosed, gas-filled space (1i; 2i) inside the unit. The piston (1h; 2h) in each spring unit (1; 2) is sealed against the cylinder wall (1a; 2a). The piston (1h; 2h) and/or the end wall (1c; 2c) has a recess which forms an annual chamber (1j; 2j). The piston rod (2b) in the slave spring unit (2) has a smaller diameter than that in the working spring unit (1).

Abstract: A pneumatic seat suspension assembly including upper and lower support members with scissors linkages extending therebetween, a pneumatic spring operatively attached between one set of opposing parallel scissors arms, a height adjuster in communication with the pneumatic spring, a dump valve in communication with the pneumatic spring and a safety rollover valve in communication with the pneumatic spring. The scissors linkage provides the mechanical connection between the seat bottom and the seat support while the pneumatic spring provides the structure to raise and lower the seat bottom by use of compressed air which causes the parallel scissors linkages to be pushed upward causing the seat to rise.

Abstract: A traverse apparatus for a yarn winding machine which non-linearly buffers the impact between the cam drum (4) and cam roller (13) due to the emission resistance and shear resistance of the viscous fluid (b) intervening between shock absorbers (10a,10b,10a',10b') arranged at the return point and reciprocally moving slide members (9,9') connected to a traverse rod (14). As the impact between the cam drum (4) and cam roller (13) is sharply non-linearly buffered due to the to the emission resistance and shear resistance of the oil, noise generated when the cam roller returns can be reduced and the decrease in durability of the traverse device caused by the aforementioned impact can be prevented.

Abstract: A damping arrangement 20 (FIG. 1(b)) for radial vibrations in a turbomachine shaft 10 comprise two circumferentially limited, diametrically opposed damping chambers 22, 23 open towards the shaft and to which gas is supplied alternately by gas flow controllers 29.sub.A and 29.sub.B. Each controller contains fluidic devices switched by sensing pressures in the circumferentially displaced chambers 22', 23', or even the same chambers, as such pressure are modulated by the variations in shaft position, to divert the gas from source 27. The diversion of gas flow is arranged to cause pressure fluctuations, which exert radial thrust on the shaft, advanced in phase to approach of the shaft so as to damp the vibration. The fluidic devices may be implemented by flow amplifiers or fluid logic flip flop 41 (FIG. 2) and may be multistage devices to increase gain, all of which may be formed without moving parts and embedded in the housing.

Abstract: A squeeze film damper covered by a pair of flexible torus shells, wherein the damping fluid is confined. The squeeze film provides the damping. The torus shells provide the stiffness within the clearance of the squeeze film. The torus shells separate the damping fluid from its environment. The torus shells also serve as a damping fluid reservoir.

Abstract: A moved mass of hydraulic medium is used as a compensating mass at critical frequencies of the suspension system to achieve a frequency-selective dynamic damping, and a suitable hydraulic transmission ratio can ensure that a relatively small quantity of hydraulic medium is moved at high speed in order to achieve a good compensating effect, despite the low mass of moved hydraulic medium. A displacement unit can be connected to the sprung mass via an elastic bearing part and to the associated spring accumulator via a hydraulic line. The spring constant of the bearing part, the mass of that part of the displacement unit or of the spring unit mounted on the bearing part, the cross-section of the hydraulic line and its length, the effective cross-section of the displacement unit and the density of the hydraulic medium are so sized that the resonant frequency of the spring unit is near a critical frequency of the suspension system, for example near the frequency of the axle resonance of a vehicle.

Abstract: A support system for supporting an experimental apparatus or a prime mover and decoupling the same from the environment comprises a vessel immersed in a tank of liquid and having support structure extending out of the liquid to support the experimental apparatus or prime mover. The mass of the total combination of the vessel, support structure, and experimental apparatus is adjusted with respect to the density of water so that the support system exhibits neutral buoyancy. Preferably the support structure is of small cross-sectional area so that a small additional mass or a force such as vibratory energy applied to the experimental apparatus produces a large excursion of the system within the water. In this way the system experiences substantial static deflection upon addition of a small additional mass, or the imparting of a small force thereto, and exhibits an extremely low resonant frequency. The device may also be readily adapted for use as a low resonant frequency oscillator.

Abstract: Mechanism for movably supporting a load, comprises a fixed frame, a pendulum lever pivotally connected at one end to the frame, and a link pivotally connected at one end to the other end of the pendulum lever. The other end of the link is connected to a vertically movable load support. A gas spring is pivotally interconnected between the frame and the link at points spaced from the points of articulation of the link and pendulum lever to the frame and to each other. Provision is made for adjusting the position of the pivotal connection between the link and the gas spring lengthwise of the link, and for adjusting the position of the pivotal connection of the gas spring to the frame in a direction toward or away from the point of articulation of the pendulum lever to the frame. Guides for the load are provided, comprising rollers mounted on the frame in between which a vertical member slides vertically.

Abstract: In a gas spring having two working chambers, a pressurized gas is provided within both the working chambers. One of the working chambers is connected with a pressure reservoir. A shut-off valve is provided between the pressure reservoir and the respective working chamber and is automatically controlled such as to admit pressurized gas from the reservoir to the respective chamber when the pressure value within the respective working chamber falls below a predetermined pressure value. The shut-off valve is closed again when the pressure within the respective working chamber has risen again up to a determined pressure. Accordingly, the pressure within the working chambers does not fall below the predetermined value as long as the increased pressure within the reservoir exists.

Abstract: A drill string apparatus for the controlled absorption of both axial and torsional forces exhibited on the well string during drilling operations. The device is adapted to be connected in the drill string above the drilling tool in order to control the forces acting on the bit and to arrange the mean weight on bit for the selected drilling operation. Generally, the apparatus includes an outer casing coupled at its upper end to the drill string and an inner assembly telescopically received within the outer casing and connected at its lower end to the lower part of the bottom hole assembly or the drilling tool. Rotational torque is transferred from the drill string and outer casing to the inner assembly and drill bit by a series of helical splines. The mean weight on bit is controlled through an interchangeable pressure control nozzle mounted at the top of the inner assembly.

Abstract: A tube having a welded bottom impermeable to gases under pressure, the tube including (a) a tube body having an end with an inner peripheral edge folded-over toward the interior of the tube body for forming an opening of reduced diameter; and (b) an end piece for forming the welded bottom of the tube, the end piece including a metal disk with an outer diameter substantially smaller than the inner diameter of the tube body and substantially greater than the reduced diameter of the opening of the inner peripheral folded-over edge of the tube end, the disk having at the center thereof a cylindrical outwardly directed projection, the projection having a diameter slightly smaller than the reduced diameter of the opening of the peripheral folded-over edge of the tube end, wherein the end piece is located inside the tube body and joined to the folded-over edge by a welded zone having a metallographical structure of melted or softened metal, the welding zone having an exposed surface in the bottom of a narrow groove