Abstract: A swivellable fitting assembly has a housing with a stem with a rotatable nipple on the stem. The rotatable nipple is sealed and spaced from the nipple to enable rotation of the nipple or housing with respect to one another.

Abstract: This invention pertains to a rotary joint for use with rotating machinery where the joint is conveying high temperature corrosive fluids such as molten salts. The joint includes both a stationary head to which external connections are made and a housing mounted on and rotating with a rotary apparatus with which the joint communicates. Alignment of the components is maintained through the interaction of two sleeve bearings disposed between a nipple coaxially extending from the head and the joint housing surrounding the nipple; the sleeve bearings being axially displaced from each other, the primary seal occupying an intermediate position. The primary seal is a spherical seal, interposed between a stationary nipple seal surface and a rotary housing sealing surface. The seal is preloaded by means of an external joint biasing support bracket to reduce leakage under conditions of low internal fluid pressures.

Abstract: A rotary joint for introducing or removing a heat exchanging medium, such as steam, from a rotary dryer drum characterized by its ability to accommodate significant axial expansion or contraction with respect to the axis of drum rotation. A rod supported housing includes an axially displaceable nipple having an end engaging an annular seal ring associated with a drum journal mounted wear plate. Axial movement between the wear plate and joint housing is accommodated by relative movement between the housing and nipple, and preferably, springs axially bias the nipple into engagement with a self-aligning seal ring to maintain a fluid tight connection under all thermal and pressure conditions.

Abstract: A flexible pipe joint system has three swivel joints on the both sides and in the central portion thereof, and two arm pipes connecting the swivel joints. The swivel joints have a stepped cylinder body, an elbow and a cap nut. The stepped cylinder body has a larger diameter portion and a smaller diameter portion. The elbow has a pipe connection portion to which a nipple provided with a flange on its outer end and a nut member on its outer periphery. A short cylindrical adapter is provided at one end of the arm pipe connected to the pipe connection portion of the elbow and to one end of the arm pipe connected to the smaller diameter portion of the cylinder body. The adapter and the nut member, respectively, have an outer diameter smaller than the inner diameter of the gasket and an inner diameter of an end portion of the cap nut.

Abstract: This invention is directed to a novel rotary joint or coupling which is useful for coupling a rotating element to a non-rotating element. More particularly, this invention is directed to a novel rotary joint or coupling which couples a rotating element to a non-rotating element and allows for the passage of a process fluid from the rotating element to the non-rotating element or vice versa, and seals the flowing process fluid from the external environment.

Abstract: In a rotary coupling for conducting a medium under pressure from a stationary machine part to a rotating machine part, a radially movable bushing is provided between a housing and a rotatable shaft of the rotating machine part. The radial gap between the housing and the bushing is bridged or spanned by a plurality of elastic sealing members to provide radial adjustability. A ceramic coating to minimize radial differences due to thermal expansion during frictional heating can also be provided on the shaft.

Abstract: A two-piece adapter for rotatably connecting two fluid transport members, the adapter including a stem for one of the members, and a connector (which may be for example a Luer connector) for the other member. The connector has a collar which is wrapped around the flange to capture the stem. The collar is deformed to wrap around the flange after the flange and the collar are joined. Preferably the adapter is made of plastic, transparent material.

Abstract: A swivel joint for high pressure fluid capable of preventing the leakage of the high pressure fluid and smoothing the rotation of the rotating one of the shaft member and the receiving member, with a simple and compact structure, which can be manufactured inexpensively. The swivel joint includes a cylindrical cavity formed inside the receiving member and around the shaft member. including: a contacting end, normal to an axial direction along the axis of relative rotation of the shaft member and the receiving member, contacting with the high pressure fluid through the connecting portion connecting the fluid paths of the shaft member and the receiving member; a movable sealing member, movable in the axial direction, contacting with the high pressure fluid through the contacting end; and a hollow chamber, separated from the contacting end by the movable sealing member, confining the fat oil.

Abstract: A universal swivel body for a fluid handling hose connector has threaded inlet and outlet ends connected by an axial fluid passageway and capable of attachment to a stationary fluid supply line and a rotating fluid service line. The axial fluid passageway has a number of internal circumferential sealing surfaces, each of which is sized and located to provide a fluid tight seal in cooperation with a compliant seal ring and with a corresponding sealing surface on a swivel adapter designed for a particular working pressure. The outlet end of the swivel adapter is capable of rotation with respect to the swivel body so that the device can be used with a hose reel.

Abstract: The invention relates to a threaded swivel connector (1) for connecting a housing (3) to a member (2) by means of a hollow bolt (7). For improving the sealing effect, there have been provided specially designed sealing edges (15) of a collar (8) of the bolt (7) to seal with the housing (3) and sealing edges (21, 25) of a sealing ring (18) between the housing (3) and the member (2) to be connected. The sealing edges (15, 21, 25) are formed between inclined annular faces (16, 17, 19, 20, 22, 23), one at an acute angle to a plane (E1, E2, E3) at right angles to said axis and the other oppositely inclined at a greater angle.

Abstract: There is provided rotatable pressure tight pipe joints and non-rotatable pressure tight pipe joints. The rotatable pressure tight pipe joints preferably have mating spherical surfaces with a sealing ring overlapping the joint between two pipe ends and compression means resiliently holding the two body parts of the joint in contact. In the non-rotatable joints, the intersecting surfaces form a zigzag cross-section and are compressibly clamped together.

Abstract: A rotary connector for selectively coupling a rotating pipe to a stationary pipe includes a housing for interconnection to the stationary pipe. A rotary stem is disposed within the housing for providing a fluid communication path between the rotating pipe and the stationary pipe. The rotary stem is selectively removable from the housing without removal of the housing from the stationary pipe. A seal is provided and is interconnected to the rotary stem and disposed between the rotary stem and the housing for sealing the rotary stem within the housing. The housing seal is selectively removable from the housing with the rotary stem. The rotary connector further includes a rotary flange for interconnection to the rotating pipe for selectively mounting the rotary stem to the rotating pipe for the transfer of torque to the rotary stem. The rotary stem can be selectively removed from the rotary flange without removal of the rotary flange from the rotating pipe.

Abstract: A system for maintaining a tightness between two parts rotatable relative to each other. The system includes at least two sealing units, with each of the sealing units having at least two possible states or conditions, namely, a first state or condition for ensuring a tightness between the two parts and a second state or condition wherein it does not ensure a tightness. Each sealing unit is deformable and includes a drive arrangement for intermittently actuating each of the sealing units.

Abstract: A universal-type coupling member including a head portion, a stem portion rotatable in the head portion, and a gasket inset in the head portion and in sealable contact with the stem portion, and having a fluid passageway therethrough is provided, which can be connected to another appropriate universal-type coupling member. Use of the coupling member of this invention can relieve the uncoupling effects of twist or torque in universal-type coupling combinations.

Abstract: Fuel rail assemblies include a tubular fuel rail for supplying fuel to a fuel injector of an internal combustion engine. Rigid conduits are coupled to the fuel rail so as to allow relative rotational movements therebetween and thus permit, during production, the correction of any angular mismatch between the injectors and the engine with which the injectors are to be associated. A longitudinally extending, lateral ledge may be provided so as to support a clip which retains the injectors in the fuel rail assembly during production. Countercurrent flow within some embodiments of the fuel rail assemblies is provided by positioning an inner conduit within an outer conduit so as to establish therebetween a fuel flow passageway. Thus, the supply and discharge nipples for the fuel rail may be provided in close physical relationship with one another and thereby more easily facilitate their interconnection to a vehicle's fuel system during production.

Abstract: A pivoting joint for an irrigation system includes a housing (38) having a fixed end (42) and a pivoting end. The pivoting joint is generally disposed in a 90.degree. elbow configuration with the pivoting joint formed by a stop (46), a length of pipe (50) and an O-ring (48). The stop (46) is disposed in the pivoting end of the housing (38) with the pipe (50) disposed on the interior thereof, the pipe (50) having an outer diameter that is slightly smaller than the inner diameter of the stop (46). The stop (46) is cemented to the interior walls of the housing (38) with the O-ring (48) disposed at the inner end of the stop (46). The pipe (50) has a stop (52) disposed on the interior end thereof and disposed diametrically opposite the O-ring (48) from the stop (46). The stop (52) forms a rim having an outer diameter slightly less than that of the housing (38) but greater than the interior diameter of the stop (46).

Abstract: A faucet spout assembly includes a tubular spout and a spout support nut. The spout has a discharge which is a substantial distance from the spout inlet. The spout support nut is used to mount the spout to a supporting waterway and provides both support for the spout to prevent wobble and a seal preventing undesirable moisture and other comtaminants from reaching the interior of the spout/support nut connection.

Abstract: A cementing head apparatus includes a container body having a body bore therethrough. Upper and lower releasing mechanisms are associated with the container body. The lower releasing mechanism has a cylindrical plunger extending into a bore of the container body. A spherical releasing ball rests upon the plunger of the lower releasing mechanism. The upper releasing mechanism is identically constructed and is associated with a releasing dart. Upper and lower ends of the container body have complementary male and female straight threads with associated O-ring seals defined therein. A lifting sub is directly connected to the upper thread and has a loading bore defined therethrough. A cap closes an upper end of the loading bore of the lifting sub. A swivel is directly connected to the straight thread at the lower end of the container body.

Abstract: A fitting consisting of a cap having a tube projecting radially or along the longitudinal axis of the injector, for connecting the injector supply tube, the cap being fitted in idle and fluidtight manner, via the interposition of an O-ring, on to a union on the injector; and a pair of coaxially-mating half rings fitted in axially integral manner partly on the cap and partly on the union, and held together by a retainer ring snapped externally on to the same.

Abstract: A tap includes a seat, two valves disposed on both ends of the seat, an outlet pipe rotatably provided on a center portion of the seat, a connecting pipe communicating the valves and the outlet pipe. A sleeve is disposed on the center portion of the seat. A collar is slidable in the sleeve and embraces a lower end of the outlet pipe. A retaining means is provided between the collar and the connecting pipe for rotatably holding the lower end of the outlet pipe so that the outlet pipe is stably and rotably held in the sleeve.

Abstract: Connection for fluids comprising a movable hollow joint (1) equipped with a lateral tubular duct (15) and two conical through-holes, opposite and coaxial (2) and (2') whose axis is perpendicular to that of the lateral duct; a clamping screw inserted in the through-holes (2) and (2') of the joint (1). The shank (3) of said screw is provided with a central duct (12) coaxial with the axis of said holes (2), a transversal hole (14) which connects said duct (12) with the internal chamber (13) of the joint and two round grooves (10) and (11) at said through-holes (2) and (2'); and flexible round gaskets (9) and (940 ) inserted in said grooves (10) and (11).

Abstract: A 90 degree swivel coupling formed of a general purpose and heat-stabilized injection molding grade 6/6 type plastic resin includes a socket member and a stem member in telescoped relation. The socket member includes an outer skirt connected by spaced flexing arms to a connecting body portion. The skirt and opposed stem have a close complementing and mating bearing projection and recess establishing a swivel coupling. The bearing walls are inclined at an angle of 15 degrees. The skirt portion is slightly expandable outwardly. In the unstressed state, the bearing wall has a maximum diameter slightly less than that of the recess to establish a pressurized fit. The stem includes a cam having an inclined wall corresponding to the bearing projection with a maximum diameter slightly greater than the bearing wall of the skirt bearing and the same angle. The cam has a maximum smaller diameter than mating recesses in the flexing arms to allow the pressure bearing engagement.

Abstract: A liquid flow tube extends through an anti-friction bearing so that the tube can rotate around its axis while liquid is flowing through the tube interior space. A dynamic seal is arranged between the outer cylindrical surface of the tube and a stationary sleeve structure. Preferred sealing material is rope-like packing helically wound within an annular recess in the sleeve structure; an annular piston extends into the recess to apply force onto the packing for preventing any leakage across the packing interfaces (at the sleeve or tube surfaces).

Abstract: A coupling device for releasably connecting a suction hose (15) to a vacuum cleaner housing (10) includes a tube connection piece (13) attached to the suction base and adapted to be inserted into a cylindrical socket (11) in the vacuum cleaner housing. The tube connection piece (13) is rotatably attached to a coupling sleeve (16) which carries a latch (17) which is releasably connected to the vacuum cleaner housing (10) in a non-rotatable position.

Abstract: A two-piece adapter for rotatably connecting two fluid transport members, the adapter including a stem for one of the members, and a connector (which may be for example a Luer connector) for the other member. The connector has a collar which is wrapped around the flange to capture the stem. The collar is deformed to wrap around the flange after the flange and the collar are joined. Preferably the adapter is made of a plastic, transparent material.

Abstract: A fluid swivel is described, of a type which forms an annular chamber and a pair of gap passages extending in opposite directions from the chamber to the environment, with face seals along each gap passage. The fluid swivel uses a minimum number of parts and minimizes entrapment of sediment in the isolation seal lying between the chamber and the closest pressure seal. The high pressure ends of the primary and secondary seals in each gap passage, face in opposite radial directions, and the low pressure end of each secondary seal lies about as far from the axis of rotation of the swivel as the low pressure end of the corresponding primary seal. The gap passage includes a tapered portion leading from the annular chamber to the isolation seal, to enable circulation of fluid up to the isolation seal to minimize the buildup of sediment.

Abstract: A swivel joint having a connection means rotatable within another connection means held together by a lock means.

Abstract: A system for maintaining a tightness between two parts rotatable relative to each other. The system includes at least two sealing units, with each of the sealing units having at least two possible states or conditions, namely, a first state or condition for ensuring a tightness between the two parts and a second state or condition wherein it does not ensure a tightness. Each sealing unit is deformable and includes a drive arrangement for intermittently actuating each of the sealing units.

Abstract: A rotary pipe coupling with replaceable seals is described. The pipe coupling has a first seal element connected to a first body portion and a second seal element connected to a second body portion. The seal elements are defined stepped seal cavities into which are disposed seals. The first and second body portions are removably coupled to respective outer and inner ball races of a ball race to permit relative rotation of the first and second body portions. The effectiveness of the inner seal can be ascertained by detecting the pressure of fluid at port via a stop valve and passage extending to the interface between the seals. The seals can be replaced, if required, by separating first and second body portions by removing one set of fasteners securing one of the body portions to the bearing unit to expose seal cavities.

Abstract: An automatically locking tubing coupler includes a barrel adapted to slidably engage with the end regions of two or more lengths of tubing and two or more sets of locking lugs positioned upon the barrel and adapted to automatically grip the lengths of tubing in their end regions when the lengths of tubing are slidably engaged with the locking lugs.

Abstract: A swivelable quick connect assembly for transferring of high-temperature, low-pressure fluids is disclosed as comprising a device having an axial bore for receiving one end of a conduit, a retaining element being demountably coupled to the device in the axial bore, the retaining element having a securing portion for securely fastening the conduit in the retainer element, a device engaging portion for retaining the retainer element in the axial bore of the device and the retainer having a sealing element with a concentric ring design for effecting a seal between the device and the conduit.

Abstract: A rotary joint for establishing communication of a pressurized medium with a rotating heat exchanger drum wherein the joint seals and associated structure are of such configuration to permit internal balancing with respect to fluid pressures imposed thereon. A rotating nipple within the joint body utilizes spherical seal surfaces engaging annular seal rings to achieve self alignment and the nipple includes spring biased collars which automatically compensate for wear and retaining structure limits collar displacement to prevent joint damage.

Abstract: Seal for a rotatable pipe coupling of large dimensions such as the swivel of a mooring device, comprising a sealing ring (30) of substantially rectangular cross-section (31) place in a rectangular groove (29) which bridges the gap (27) to be sealed, the sealing ring (30) being placed in the groove (29) in a manner such that it can expand or contract by temperature variations inside the groove (29). This can be achieved by providing radial clearance (34) between the inner face of the ring (30) and the opposite wall (28) of the (29) and/or clearance (35) between the ring (30) and the outer wall of the groove.

Abstract: A section of metal pipe has one end connected to a main line pipe. A hollow cylindrical plastic piston having a plurality of O-rings thereabout is slidingly and sealingly received within the open end of the metal section. A plastic carrier pipe is fixedly received within the outwardly facing end of the piston for suitable interconnection to other equipment. First and second limits are spaced along the pipe section to locate the piston within the pipe section. These limits may be flanges machined into the pipe section, or the pipe section may be rolled so as to include an inwardly directed, circumferentially extending ridge. In a further version, the transition joint is incorporated into a riser arrangement in which the plastic carrier is located within an outer tubing or pipe and held spaced from the tubing walls throughout the entire length of the tubing. Also, replacement of a service line is accomplished by threading plastic pipe through original line and terminating via transition joints at each end.

Abstract: A method and device for assembling connection fittings such as couplings, between hard components, such as metal pipe and a body formed of a softer substance to obtain a permanent coupling able to withstand aging and thermal shock conditions. The parts coupled are formed of materials of different hardness which are first force fit together. One of the parts is then rotated at high speed so that the part made of the softer material is locally heated until it melts. The result is a snug but swivelable connection free of internal stress.

Abstract: In a high pressure washing apparatus with a spray handle and a flexible hose leading to it, in order to create the possibility of rotation between the hose and the spray handle, it is proposed that the spray handle should display a barrel, for connecting to the hose, into which can be inserted in sealed fashion a hose nipple connected to the hose end, that a bearing surface be provided on the spray handle, against which rests a flange connected with the hose nipple, and thereby preventing the hose nipple from being pulled from the barrel, and that the bearing surface and/or the hose nipple flange surround the hose nipple in ring form, and be rotatable with respect to one another around the longitudinal axis of the hose nipple.

Abstract: A pipe fitting comprising a first part (1) with a rotatable insert (15) axially located therein by an annular abutment face (19) and having resiliently radically deflectable abutment faces (12a) which are engageable with ends (7a) of notches (7) of a second tubular part (2), rotation of the insert relative to the tubular part (2) enabling the abutment faces (12) to ride out of the notches (7) to permit release of the tubular part (2) from the first part (1).

Abstract: A quick connect coupling (20) for fluid tight connection to a threaded fluid port (22). A body (26) of the quick connect coupling (20) having a cylindrical, externally threaded first end (28) defining an axially extending passage (29) into the coupling body (26). Axially slidable sleeve (42) being mounted on the outside of the coupling body (26) for slidable motion between a seal unassisted position and a seal assisted position, the axially slidable sleeve (42) forcing against an elastomeric seal (30) in the seal assisted position so as to provide a fluid tight seal between an end of the fluid port (22) and the coupling (20).

Abstract: The invention concerns fluid power connector fittings for joining a piece of elastic hose with a fixed structure such as bulkhead or with another piece of hose. The novel connector fitting may be thought of as comprising two sections each having a shank adapted for connection with a piece of hose or with a screw threaded hole in a structure. If the two shanks are at an angle to each other there is a swivel joint between them. If they are in line they are made integrally.

Abstract: A swivel hose coupling assembly and method provides a collar having an angularly inwardly disposed locking annulus. The angular disposition of the locking annulus permits a novel method of assembling the swivel hose coupling members.In a preferred form, the assembly is designed for affixation to one end of an elastomeric hose, and includes a cylindrical insert having a serrated external surface at one end thereof, a shoulder at an opposing end, and a locking groove intermediate the serrated surface and shoulder. A fitting is rotatably mounted over the insert, the fitting having a mating shoulder for contact with the shoulder of the insert. An annular collar is concentrically positioned over an exposed end of the fitting, a first end of the collar containing the locking annulus being inserted first over the serrated portion of the insert.

Abstract: A swivel fitting arrangement for use in a pressurized fluid line, especially a high pressure, high flow rate line, is disclosed herein and utilizes first and second adjacent sections of the line in coaxial and unconnected relationship to one another so as to define an axial joint between the two sections and such that the first section is able to rotate aboout its axis relative to the second section. The arrangement also includes means for supporting the two line sections in their coaxial and unconnected relationship with one another and a tubular sealing member disposed coaxially within the line and across the axial joint between and directly against the adjacent sections and joint for internally sealing the joint while allowing fluid within the line to pass from one of the sections to the other.

Abstract: A pipe seal connection defines the seal between confronting pipe ends of two pipes which are coaxial and rotatable relative to each other. The confronting pipes ends are provided with spaced conical surfaces forming therebetween an annular slot which widens radially outwardly. An annular seal ring is positioned within the annular slot. A clamping band circumferentially surrounds the annular sealing ring and presses the sealing ring radially inwardly into contact with the spaced conical surfaces.

Abstract: Airtight rotating joint, composed of a fixed part and of a rotating one both equipped with an axial conduit ending in a chamber, rendered airtight and separated from the outside by means of a second pressurizable chamber. The joint is particularly suited to equipment where high-purity materials are to be handled.

Abstract: A rotatable swivel comprising a swivel body, a ball bearing assembly, and a primary upper seal axially offset from a primary lower seal for sealing a conduit chamber is disclosed. Pressurization of the conduit chamber of the swivel in cooperation with the differential axial offset of the primary seals creates axial pre-loading of the swivel operably aiding in the sealing of the conduit chamber and maintaining the concentricity of the bearing assembly between a rotatable outer ring and a stationary inner ring and providing wear compensation for the swivel. Secondary upper and lower seals are disclosed whereby if the primary seals fail to retain pressure in the conduit chamber, the respective secondary seal maintains the initial axial loading of the failed primary seal.

Abstract: A quick-coupling assembly for fluid conduits and of the kind comprising a first sleeve-shaped member, which at one end is provided with a number of resilient tongues provided with at least one projection intended to be locked behind at least one shoulder or the like in a second sleeve-shaped member for being connected to this and a ring being actually displaceable in the second member towards and away from the shoulder and being designed to cooperate with the tongues for compressing these so that they can be moved past the shoulder. The object of the invention is to provide a quick-coupling which despite high pressures (e.g. 350 bar) is easily rotatable so that a pressure hose connected to the coupling really can rotate, which is especially important at many hydraulic arrangement where relative movements occur between different structural parts connected to each other by pressure hoses.

Abstract: A coupling unit of tubular overlapping conduits that are swivelly coupled to each other and are locked together by a spring loaded hook type rocker arm member centrally hinged upon a boss on the outer overlapping conduit. The rocker arm member has an inward hook at one end and an outward spring member guide push button on the opposite end. The hook end is normally maintained radially inward through an aperature in the outer conduit and the push button is normally positioned radially outward to protrude through an aperature in a protective cover closure bonnet. The hook end of the rocker arm member cooperates with a hook and groove formation on the inner conduit to lock the inner and outer conduits together.

Abstract: A rotary joint or union characterized by its ease of assembly, disassembly and maintenance wherein a mounted internal condiut supports a rotary anti-friction bearing housing to which a seal housing is removably attached by bolts. A conduit port defined in the seal housing communicates with the interior of the conduit. A bearing retainer mounted upon the end of the conduit includes a seal having a radial face engaging the radial face of a seal mounted on the seal housing in a self-aligning manner. A compression spring maintains engagement of the seal faces through a seal assembly, and the seal housing seal is mounted within a retainer loosely keyed to the seal housing to facilitate self-alignment.

Abstract: A device for connecting together tubes or pipes is disclosed, which comprises a cylindrical male coupler provided on one end of a first tube or pipe and having an engagement projection formed on the outer periphery, and a female coupler provided on one end of a second tube or pipe and having a helical engagement notch for receiving the engagement projection. The two couplers can be tightly coupled together by fitting the male coupler to the female coupler such that the engagement projection is received in the helical engagement notch and then turning the couplers relative to each other.

Abstract: A multi-plane swivel connector for use in attaching a pair of fluid conveying members together, the connector including a pair of swivel portions, that connect together at proximate ends, one end being insertable within the other, a double sealed connection provided at the junction of the connection of the swivel ends together, there being a swivel nut securing externally to the outer end of one of the pair of swivel portions, there being a double sealed connection provided between the said swivel nut and the said contiguous swivel portion, there being a pair of O-rings provided at each of the double sealed connections between the swivel portions, and the connection of the swivel nut to one of these swivel portions, said pair of O-rings at each double sealed connection being of step relationship with one O-ring being of greater diameter than the other O-ring, one of the O-rings being formed of fluoro carbon, while the other O-ring of each double sealed connection being formed of fluoro silicone; and during th

Abstract: A stationary annular plenum rotatably mounted upon a hollow shaft receives air from a stationary source of air under pressure. A spring loaded first ring within the plenum conveys the air through apertures therein from the plenum to corresponding apertures in an adjacent second ring, which rings are maintained in alignment with one another and the plenum by a plurality of dowels. An annular channel disposed in a radial face of the second ring interconnects the apertures extending through the ring; the channel mates with a corresponding channel of an adjacent disc fixedly mounted upon the shaft to convey air from the stationary elements to the rotating elements. An air seal between the second ring and the disc is formed by interfacing flat annular radially oriented surfaces on opposed sides of the respective channels. The disc includes a radial passageway interconnecting the channel formed therein with the bore of the hollow shaft to direct air into the bore.