Abstract: A charge-air cooler hose includes a hollow cylindrical structure defining an air conduit, an outer surface, and a bellows section, where a plurality of convolutions are formed on the bellows section and the bellows section includes a plurality of ridges and a plurality of valleys. At least one of the plurality of ridges has a diameter and/or shape different from other ridges. In some cases, the bellows section has two ridges. In some other cases, the bellows section has three ridges. Where there are three ridges, each of the three ridges may have a diameter different from one another. In an embodiment where there are three ridges, a first ridge has a diameter D3, a second adjacent ridge has a diameter D4, and a third adjacent ridge has a diameter D5, and where D3<D4<D5.

Abstract: A bellows excellent in durability has an accordion shape where crest parts with U-shaped cross sections and trough parts with U-shaped cross sections are repeatedly formed via slope parts, the slope parts leading to the crest part includes first portions, second portions, third portions and fourth portions which are continuously connected, in order, to one another from the crest part toward the adjacent trough parts, and in a free length state of the bellows, a separation distance between the second portions of the both slope parts is longer than separation distances between the first portions and between the third portions.

Abstract: A material-mapped actuator useful as, or as part of, a soft robot along with automated methods of design and manufacture. The actuator exhibits mechanical properties that spatially vary along a coordinate system of the actuator. The actuator body has an initial shape with a corresponding initial map of mechanical attributes consisting of locally-varying stiffness at each point in a volume of the actuator body. The actuator is configured to change to a different shape or distribution of mechanical properties upon being activated by an actuation medium. The map of mechanical attributes influences and determines the new shape or distribution. The material-mapped actuator can incorporate a spatially-varying distribution of mechanical properties that dictates multiple desired shapes as the actuation medium is applied, including an actuation sequence in which the actuator transitions from a first shape to a desired intermediate shape(s), and from the intermediate shape to a desired final shape.

Abstract: The invention relates to a protective cover (01) comprising at least one protective cover element (02), which is variable in length, and comprising a frame element (04), said frame element (04) being capable of being connected to the protective cover element (02), said protective cover element (02)comprising at least one holding means (03) and said frame element (04) comprising at least one fastening means (06) in the area of a first longitudinal edge (05a), the connection between the holding means (03) and the fastening means (06) being a detachable, in particular force-fitting and/or interlocking, snap connection.

Abstract: A metal bellows of great durability capable of preventing breakage at both end portions of the metal bellows is provided. The metal bellows is annular-shaped and has, axially repeatedly, a structure in which, from an axial end portion 10c, a belly, a valley, a belly, a peak, and a belly are integrally formed in series sequentially in this order. The end portion 10c has a first connection belly 10d connected to a fitting member 15, and a connection valley 10e and a second connection belly 10f extending sequentially from the first connection belly 10d axially inward. The axial width b1 of the connection valley 10e in a free state is set larger than the axial width of valleys 10i, 10m, . . . or peaks 10g, 10k, . . . in a portion other than the end portion 10c.

Abstract: A metal bellows (110) for an accumulator (100) into which a hydraulic fluid is drawn in, has a bellows-shape in which ridge fold portions (110a) and valley fold portions (110b) are formed repeatedly with slope portions (110c) in between, wherein two of the slope portions (110c) that are adjacent to each other via a common ridge fold portion (110a) have: first slope portions (110c1) which extend from the common ridge fold portion (110a) and second slope portions (110c2) each of which extends from each of the first slope portions (110c1) such that a distance therebetween becomes much greater than the first slope portions (110c1) as the second slope portions (110c2) extend toward the adjacent valley fold portions (110b), wherein the first slope portion (110c1) and the second slope portion (110c2) are connected at an inflection point (P).

Abstract: The present invention relates to a sealing head for machines for heat treating threads, comprising a frame fixed to a pressurized chamber through which a conveyor belt passes, a pair of horizontal rollers placed on top of each other and pressed against the opposite faces of the conveyor belt and of seals to form a sealed closure between the rollers and the frame, at least one of the horizontal rollers and the seals being connected to the corresponding movement actuators. Sealing head characterized in that the actuators of the horizontal roller or rollers and the seals between the rollers and the frame are in the form of pneumatic actuators without pistons, namely of the balloon or bellows type.

Abstract: A vacuum powered system for moving a movable component, such as for raising and lowering a stowage container, includes a vacuum actuator connected between a fixed structure and a movable component. The vacuum actuator includes one or more intake ports that are configured to connect with a source of vacuum for moving the movable component in a first direction to a first position, and one or more bleed valve ports for venting the vacuum actuator to move the movable component in a second direction to a second position. The vacuum actuator may be an air bellows, a single acting linear vacuum actuator, or a dual acting linear vacuum actuator. A guiding system is further provided that includes elongated tracks in a stationary stowage container housing that houses the movable component, and corresponding guide elements on the movable component that slidably engage with the elongated tracks for moving the movable component.

Abstract: A flexible tube for an exhaust pipe of an automobile includes a bellows member having corrugations thereon; an interlocking member positioned in the bellows member with a predetermined gap from the bellows member and having a spiral groove formed thereon to absorb deformation; a braid member positioned to surround the outside portion of the bellows member and braided to be flexibly deformed with a large displacement with respect to a displacement and tension in a compression direction; cap members coupled for fixing the braid member on the outside of the both ends of the bellows member; and intermediate members formed in the shape of a ring and having one end fixed to the bellows member and the other end fixed to the interlocking member by overlapping the interlocking member inwards, wherein the bellows member has protrusion portions, a center part and both end parts.

Abstract: A bellows is disposed to separate a main flow path that is opened or closed by a valve member coming into contact with or moving away from a valve seat from a driving part for driving the valve member via a rod so as to surround the rod. The bellows is formed by providing ring-shaped valley portions swelling inward of a metal pipe and ring-shaped peak portions swelling outward of the metal pipe alternately and continuously in a peripheral wall of the metal pipe in the axial direction of the metal pipe. Valley R/peak R, which is the ratio of valley R to peak R, is in the range of 1.15 to 1.70, where valley R is the radius of curvature of the valley portions in cross section, and peak R is the radius of curvature of the peak portions in cross section.

Abstract: A footwear, more particularly a slipper, comprising bottom portion including a cushioned sole and an air bellow-actuated mechanism utilizing a flat tensioning device to control the movement of portions of the slippers thereby providing an animated function such as an extension of a portion of a character positioned on the plush top of the slipper actuated as a result of the movement of the wearer of the slipper.

Abstract: A pump system includes at least one pressure chamber at least partially defined by a helical bellows plunger comprised of a tubular body, a closed front portion, an open rear portion, and at least one contour extending continuously as a helix, longitudinally from proximate the front portion to proximate the rear portion. Methods for forming a helical bellows plunger include molding the helical bellows plunger using a mold core comprising a helically extending exterior contour and a cooperatively associated mold cavity comprising a helically extending interior contour of substantially a same pitch and configured to align with the helically extending exterior contour of the mold core, introducing a molding material therebetween, curing the molding material, and unscrewing the cured molding material from the mold core. Various configurations of helical bellows plungers are also disclosed.

Abstract: A hydraulically driven diaphragm pumping machine comprises a plunger (6) that is slidably mounted in a middle part of the inside of the machine's hydraulic cylinder (5) between first and second bellow-like diaphragms (4,10). Ends of the plunger (6) are connected to the first and second bellows-like diaphragm (10) to define respective first and second outer annular spaces (a) that are independent of one another, and the pressure of fluid in the first annular space (a) is independent of the pressure of fluid in the second annular space (a). The machine may also comprise a hydromechanical switch for commutating a valve (102) to automatically control the supply of hydraulic fluid to the hydraulic cylinder at given moments of the machine's cycle.

Abstract: A diaphragm pump for use in a self-inflating tire assembly is disclosed. The assembly includes a tire mounted to a rim tire mounting surface. The tire has an internal cavity. The invention further includes a pump device mounted to the rim, and the pump device has a first end and a second end, the first end being mounted within the tire cavity and the second end located outside the rim and in fluid communication with the outside air. The first end of the pump device has a flexible member having an outer rim and an inner rim, wherein the outer rim is connected to a backing plate and an inner rim is connected to a piston, wherein the piston is slidably mounted within a chamber of the backing plate. The piston has an inner passageway for fluid communication with the tire cavity and the chamber, and the second end of the pump device has an internal bore in fluid communication with the outside air and the chamber.

Abstract: A high inertance liquid piston engine-compressor that is lightweight, portable and for use with pneumatically actuated devices that may have periods of inactivity between periods of pneumatic use. The engine-compressor provides a power generation system that is for use with mobile or portable devices which need a portable long lasting energy source.

Abstract: Provided are: a table on which a workpiece is placed, a laser oscillator emitting a laser beam; a light-guide optical system deflecting the beam emitted from the oscillator; a cylindrical extensible bellows surrounding an optical path of the beam after the light-guide optical system deflects the beam; a bend mirror moving in an axial direction of the bellows while extending/contracting the bellows and deflecting the beam having passed through the bellows toward the table; a machining head irradiating the workpiece with the beam deflected by the mirror; an abnormality detector including a beam-sensor light-emitting unit emitting a beam advancing parallel with an axis of the bellows and a beam-sensor light-receiving unit measuring the amount of received light of the beam; and a control device bringing down the laser oscillator when the amount of received light of the beam in the beam-sensor light-receiving unit falls below a first threshold.

Abstract: An actuator is provided for raising the front hood of a vehicle having at least one extension part, by whose extension movement the front hood of the vehicle can be raised or is raised. It is provided that the extension part is at least partially formed by a planar formation, which is deformable from a first shape (e.g., a starting shape) into a second shape (e.g., an intermediate shape or final shape) to raise the front hood. Furthermore, a motor vehicle is provided that has an actuator for raising the vehicle front hood and a pedestrian protection system for a vehicle.

Abstract: A flexible processing and/or expressor chamber for a biological cell processing apparatus is provided which may include a first side and a second side and having a expandable wall, wherein a first end of the expandable wall is attached to a circumference of the first side of the flexible chamber and a second end of the expandable wall is attached to a circumference of the second side of the flexible chamber. Either or both sides of the chamber may include an axial opening.

Abstract: The fluid section of an air operated double diaphragm pump 10 consists of two fluid housings 12, an inlet manifold 14, and an outlet manifold 16. The housings are to be made in two parts. The preferred frame 18 material is glass fiber reinforced with polypropylene that is overmolded into final shape with an encapsulating material 20. The frame 18 is designed so that the encapsulating material 20 can flow from one side to the other allowing for a mechanical lock between the top surface 22 and the bottom so as not to rely on chemical adhesion between the two materials.

Abstract: The disclosure relates to a membrane pump head for a homogenizer or a high-pressure pump. The membrane pump head comprises at least one pump head enclosed in a pump housing. The membrane pump head also includes a product chamber with inlet and outlet for the product, as well as a hydraulic chamber in which a piston is disposed to operate. The product chamber and the hydraulic chamber are separated by a double membrane. The membrane is oriented at 15-75° in relation to the longitudinal direction of the piston.

Abstract: A cantilever feedback mechanism includes an upper cantilever and a lower cantilever. The upper cantilever and lower cantilever have a resistance spring rate to facilitate movement of the bellows over a selected range of resistances. The upper cantilever has downwardly oriented upper cantilever stops. The lower cantilever has upwardly oriented lower cantilever stops that engage the upper cantilever stops. Mean are provided for applying a preload to maintain the lower cantilever stops and the upper cantilever stops engaged until a force urging movement exceeds the preload.

Abstract: The present invention provides a body fluid suction reservoir including a flexible bag, two plates for supporting the bag, and a spring put between the two plates. The body fluid suction reservoir further includes a lock having a hook and a release part and consisting of a member different from the two plates, by which lock the spring is held in a state compressed between the two plates, and the held state is releasable. The lock has flexibility and is held by one of the plates so as to be deformable from a first state in which the hook is engaged with the other plate to a second state in which the hook is not engaged, and the lock is urged to take the first state.

Abstract: The present invention provides an assembly of bellows part and a part against which unrolling takes place (the unrolling part), comprising a bellows part with a flexible wall of a predetermined shape and thickness variation which co-operates with an unrolling part with a stiff outer wall along which the flexible wall is movable, wherein the unrolling part has a predetermined diameter variation and/or the flexible wall has a predetermined thickness variation so as to cause a desired development of force.

Abstract: Gas of a predetermined pressure, which is equal to or higher than the atmospheric pressure, is filled in a damper chamber of a damper member that includes first and second-side diaphragms. A first-side limiting portion of a first-side cover member and a second-side limiting portion of a second-side cover member are engageable with a first-side concave portion of the first-side diaphragm and a second-side concave portion of the second-side diaphragm, respectively, to limit bulging of the damper member when a pressure of a fluid chamber is equal to or less than the predetermined pressure.

Abstract: In a housing, a damper member is placed in a fluid chamber communicated with a pressurizing chamber, at which a plunger is reciprocated to pressurize fuel, and an opening of the fluid chamber is covered with a cover member. The damper member includes first and second-side diaphragms. A first-side support member is located between the damper member and the cover member and is engaged with a first-side outer peripheral portion of the first-side diaphragm and the cover member. A second-side support member is located between the damper member and the housing and is engaged with a second-side outer peripheral portion of the second-side diaphragm and the housing. The first and second-side support members are urged between the housing and the cover member.

Abstract: A flexible processing and/or expressor chamber for a biological cell processing apparatus is provided which may include a first side and a second side and having a expandable wall, wherein a first end of the expandable wall is attached to a circumference of the first side of the flexible chamber and a second end of the expandable wall is attached to a circumference of the second side of the flexible chamber. Either or both sides of the chamber may include an axial opening.

Abstract: The present invention provides a body fluid suction reservoir including a flexible bag, two plates for supporting the bag, and a spring put between the two plates. The body fluid suction reservoir further includes a lock having a hook and a release part and consisting of a member different from the two plates, by which lock the spring is held in a state compressed between the two plates, and the held state is releasable. The lock has flexibility and is held by one of the plates so as to be deformable from a first state in which the hook is engaged with the other plate to a second state in which the hook is not engaged, and the lock is urged to take the first state.

Abstract: A valve control system for a wellbore includes a fiber composite actuator functionally coupled to a valve operating member and means for controllably charging an interior of the actuator with fluid under pressure. A valve for a wellbore includes a valve stem and a valve seat associated with a valve body. The valve stem and valve seat are configured to enable fluid flow from an inlet port in the valve body to an outlet port in the valve body when the stem is moved from the seat. An axial contraction fiber composite actuator is functionally coupled to the valve stem. The valve includes means for controllably charging an interior of the actuator with fluid under pressure.

Abstract: A sewage system for vehicles that includes a waste hose that is extendable and retractable.

Abstract: An apparatus for angularly positioning a shaker bed, including a discharge end, includes an air source providing pressurized air, an hydraulic tank in selective communication with the air source and containing a quantity of fluid, at least one bellow in selective fluid communication with the hydraulic tank, and a lift control assembly controlling communication of pressurized air between the air source and the hydraulic tank and controlling communication of fluid between the hydraulic tank and the at least one bellow.

Abstract: A pump liquid chamber (9) is formed inside a pump bellows (7). A suction port (18) and a discharge port (19) are formed in a wall face (4a) facing the liquid chamber (9). The suction port (18) communicates with a pump inflow passage (5), and the discharge port (19) communicates with a pump outflow passage (6). A suction check valve (20) is disposed in the suction port (18). An accumulator liquid chamber (31) is formed inside an accumulator bellows (29). An inflow port (23) and an outflow port (24) are formed in a wall face (28a) facing the liquid chamber (31). The inflow port (23) communicates with an accumulator inflow passage (33), and the outflow port (24) communicates with an accumulator outflow passage (34). The accumulator inflow passage (33) is connected to the downstream of the pump outflow passage (6). A discharge check valve (21) of the pump (P) is disposed in the accumulator inflow passage (33) in an accumulator body (25).

Abstract: The present invention relates to fluid control valves. The invention provides an improved diaphragm useful for a large hydraulically-operated valve or pressure regulating valve of the type used in pipelines to transport water, oil, gas, acids, alkalis and other fluids. The diaphragm being provided with an upper face arranged to be exposed to a control hydraulic pressure and a lower face arranged to selectively seal and open a passage between a valve inlet and a valve outlet, ribs on said upper face urging the diaphragm towards a sealing position. The diaphragm being characterized by the addition of an elastomer ring element disposed adjacent to the upper face and adjacent to the largest diameter of the diaphragm exposed inside a valve to which it may be assembled, an upper face of the flexible ring element being in pressure contact with a portion of the rigid body of the valve.

Abstract: A bellows that is extendingly and contractingly deformable in the axial direction is placed in a pump body and forms a liquid chamber inside the bellows. A suction portion and a discharge portion are formed in an inner bottom face of the pump body facing the liquid chamber. Liquid is sucked from the suction port into the liquid chamber by extension of the bellows, and the liquid in the liquid chamber is discharged from the discharge portion by contraction of the bellows. The extending and contracting portion of the bellows which is configured by forming ridge-like folds and valley-like folds in a vertically alternate and continuous manner is formed into a shape in which the lower one of upper and lower lamella portions of each of the ridge-like folds, or the lower lamella portion is inclined downwardly toward the axis defining the axial direction, not only in an extending state but also in a contracting state.

Abstract: A bellows for hydraulic, hydropneumatic, or pneumatic piston-cylinder units, especially for vibration dampers or MacPherson strut units for motor vehicles, is located between the end of a piston rod and a cylinder, and covers the part of the piston rod which projects out from the cylinder to provide protection against dirt and/or damage. An interior space of the bellows undergoes a change in volume as a result of the relative movement of the piston and cylinder. The end area of the piston rod distal from the cylinder includes at least one flow connection leading to the interior of the bellows. The flow connection allows an incoming and/or outgoing flow of air. The end area of the piston rod, i.e., the end which passes through a mounting bearing connecting the piston-cylinder unit to the body of the vehicle, is provided with a flow connection connecting the interior space of the bellows to the atmosphere.

Abstract: A sewage system for vehicles that includes a waste hose that is extendable and retractable.

Abstract: A bellows that is extendingly and contractingly deformable in the axial direction is placed in a pump body, and a liquid chamber is formed inside the bellows. A suction port and a discharge port are formed in an inner bottom face of the pump body facing the liquid chamber. Liquid is sucked from the suction port into the liquid chamber by extension of the bellows, and the liquid in the liquid chamber is discharged from the discharge port by contraction of the bellows. In each of a suction ball type check valve disposed in the suction port, and a discharge ball type check valve disposed in an outflow passage which communicates with the discharge port, a cylindrical valve casing is disposed, and ball valve elements in the valve casing are caused by their own weight to be closely contacted with valve seat, thereby preventing liquid from reversely flowing.

Abstract: It is an object of the invention to, even in the case where liquid containing a sedimenting material such as slurry is used, prevent sedimenting and aggregation from occurring in a pump. As means for attaining the object, a bellows 7 that is extendingly and contractingly deformable in the axial direction is placed in a pump body 1 with setting the axis B of the bellows vertical so as to be driven to perform extending and contracting deformation, and form a liquid chamber 9 inside the bellows 7. A suction port 18 and a discharge port 19 are formed in an inner bottom face 4a of the pump body 1 facing the liquid chamber 9. Liquid is sucked from the suction port 18 into the liquid chamber 9 by extension of the bellows 7, and the liquid in the liquid chamber 9 is discharged from the discharge port 19 by contraction of the bellows 7. The inner bottom face 4a is formed into a conical shape in which the face is downward inclined as moving toward the discharge port 19.

Abstract: A sewage system for vehicles that includes a waste hose that is extendable and retractable.

Abstract: The invention provides a fluid apparatus in which two or more kinds of chemical liquids can be rapidly stirred and mixed in a pump to a uniform concentration. A barrier membrane such as a bellows or a diaphragm that is reciprocally moved in the axial direction is disposed in a pump body so as to form a liquid chamber between the barrier membrane and an inner wall of the pump body. A suction port and a discharge port are disposed in the inner wall of the pump body. Supply pipes for the two or more kinds of chemical liquids are pipe-connected to an inlet portion of the suction port so as to join together. An outlet portion of the suction port is disposed in a side face of a protruding forward end of a suction check valve which is fixed to protrude from the inner wall of the pump body into the liquid chamber, whereby the outlet portion is opened so as to eject the two or more kinds of chemical liquids toward a circumferential wall in the liquid chamber.

Abstract: It is an object of the invention to, even in the case where liquid containing a sedimenting material such as slurry is used, prevent sedimenting and aggregation from occurring in a pump. As means for attaining the object, a bellows 7 that is extendingly and contractingly deformable in the axial direction is placed in a pump body 1 with setting the axis B of the bellows vertical so as to be driven to perform extending and contracting deformation, and form a liquid chamber 9 inside the bellows 7. A suction port 18 and a discharge port 19 are formed in an inner bottom face 4a of the pump body 1 facing the liquid chamber 9. Liquid is sucked from the suction port 18 into the liquid chamber 9 by extension of the bellows 7, and the liquid in the liquid chamber 9 is discharged from the discharge port 19 by contraction of the bellows 7. The inner bottom face 4a is formed into a conical shape in which the face is downward inclined as moving toward the discharge port 19.

Abstract: An actuation device uses, for the active element, a flexible bellows operated by a pressurized fluid (usually, but not necessarily, at a pressure higher than the ambient one). The bellows is housed, for the most part of its length, inside a cylindrical cavity having the inner diameter slightly larger than the outer diameter of the bellows, so that the bellows is free to vary its length, but is restrained to bend sideways and therefore can be operated by high pressure.

Abstract: A pump (10) comprises a pair of bladders (28,30) attached to respective opposite sides of a flexure plate (32) for pumping fluid by alternately compressing and expanding the bladders. Each bladder has at least one input connector (22, 34) with a one-way valve (38) therein and at least one output connector (24, 36) with a one-way valve (40) therein, in order to provide one-way flow of fluid through each of the bladders. The pump (10) is positioned to be acted upon by a moving liquid, such as natural wave action of a body of water, for example, by being connected to floating objects on the surface. The moving liquid causes the flexure plate (32) to bend in an undulate manner, first in one direction and then in the other. This bending action causes fluid to be alternately drawn into and expelled from the bladders as the bladders are alternately expanded and compressed.

Abstract: An air is evacuated from a chamber of a bellows by a vacuum pressure supply source connected to a vacuum port of an attachment plate. The vacuum pressure in a vacuum chamber is thus balanced with the vacuum pressure in the chamber of the bellows. Consequently, the bellows is prevented from expanding by balancing the respective vacuum pressures in the chamber of the bellows and in the vacuum chamber.

Abstract: The drive part for converting the revolution movement to the wobble movement is composed of the shaft for transmitting the drive force from outside, the swash plate rotated by the shaft and the wobble plate for converting the revolution movement of the swash plate to the wobble movement. Plural pistons are reciprocated in responsive to the wobble movement of the wobble plate. The crank room containing the swash plate, the wobble plate and the piston is separated into the fuel room and the drive room by the bellows. The bearings for transmitting the drive force between the shaft in the drive room and the swash plate, and the bearing for transmitting the drive force between the swash plate and the wobble plate are placed inside the drive room in order to lubricate the bearings. By arranging plural pistons inside the fuel room, the fuel is forced to be taken in and discharged by the reciprocate movement of the individual pistons.

Abstract: A foot pedal (12, 42) for controlling operation of a vehicle is supported for movement relative to the vehicle. A cushion (22, 60), inflatable by inflation fluid, is connected with and, when inflated, extends from the pedal (12, 42).

Abstract: A pneumatically driven bellows pump includes a bellows that is reciprocable by a driving force effected by air. The bellows has an integral form of a bellows body, an expansion portion and a mounting portion. The mounting portion includes a threaded member, through which the bellows is brought into threaded engagement with a threaded member formed in a pump-driving member in such a manner as to seal the bellows.

Abstract: A blend composition having improved environmental stress cracking resistance or environmental fatigue resistance, including an ethylene vinyl alcohol polymer and a polymer of ethylene with at least one selected from the group consisting of alpha olefin having at least 2 carbon atoms, and an ethylenically unsaturated carboxylic ester monomer. Flexible products may be made from the blend by heating the blend above its melting point, forming the melted blend into a desired shape, and then cooling the shape below its melting point.

Abstract: A packless swivel joint capable of rotation without the necessity for a mechanical drive includes a hollow tubular member provided with helical corrugations of tight pitch and a corrugation pitch to corrugation with ratio of between two to one to three to one which unwinds to the application of only internal pressure. A limit stop may be provided to limit the amount of unwinding. Annular-shaped bellows of a circular cross section can be utilized to absorb lengthening of the swivel joint in applications where lengthening is to be prevented. In one preferred embodiment, the helical corrugation is preferably continuous.

Abstract: An airtight rotating driving device with eccentricity, especially for volumetric pump, the device including a bent shaft (1) presenting an input axis (5) and an output axis (10) parallel and off-centered in such a way as to carry out an orbital circular movement, and an airtight and non-rotatable sleeve (14) surrounding the shaft and comprising two metallic bellows (19, 20) linked by a guiding ring (21) mounted longitudinally in a sliding relation on the sloped intermediate section (17) of the shaft. The device converts a rotating movement into an orbital circular movement with an absolute airtightness.

Abstract: An expansible bellows, includes a pair of end plates attached together and sealed around their peripheries such that their inner faces confront each other to define between them an expansible chamber for containing a fluid. One end plate is formed with an inlet port to the chamber; and the other end plate is formed with an outlet port from the chamber. The inner and outer faces of both end plates are formed with recesses which permit the center portions of the end plates to flex outwardly, and thereby to expand the chamber, when pressurized fluid is inletted into the chamber via the inlet port and blocked from flowing out of the chamber through the outlet port.Also described is a pulsator including such a bellows serving as the expansible chamber of the pulsator.