Abstract: Disclosed is a rocker arm shaft for an automobile engine, which is effectively capable of offsetting the length change of the rocker arm shaft, which caused by heat. According to an embodiment of the present invention, a rocker arm shaft can be divided into at least two shafts. An elastic member, such as a coil spring, is positioned between the shafts. When the length change of the shafts is changed by heat, the elastic member offsets the changed length of the shafts. The rocker arm shaft is divided into a hollow first shaft and a hollow second shaft. A one end of the second shaft of the rocker arm shaft forms a receiving groove for inserting the elastic member. With this structure, the rocker arm shaft for an automobile engine does not bend nor get twisted by offsetting the changed length of the shafts by means of the elastic member.

Abstract: Joint formations that, in joining together joining members employed in a variety of electrical and electronic components, yield sufficiently high joint strength in the direction perpendicular to the plane in which two joining members join, and meanwhile in the direction parallel to the joint plane. First and second joining members have respective joint phases each formed with a different number of distinct yet continuous conformational faces, defining the joint phases so that neither is the matching complement of the other. A bonding agent interposed between the joint phases joins the joining members together. The difference in thermal expansion coefficient between the two joining members, and between them and the bonding agent, is 5.0×10?6/° C. or less. The joining members are a metal such as tungsten or Cu—W, or a ceramic such as AlN or Si3N4; and glass or a solder material is utilized for the bonding agent.

Abstract: A method of attaching a first member of one of quartz and a ceramic to a metal member. The method includes creating a hole in the metal member, the hole being smaller in size than the size of the first member over a temperature range, heating the metal member to a temperature sufficient to expand the hole to allow insertion of the first member in the hole, inserting a portion of the first member into the hole, and cooling the metal member to form a joined structure of the first member and the metal member.

Abstract: The clearances between an array of turbine blades and its surrounding blade track may be controlled by an expansion control material system supporting the blade tracks. The blade track support hoop is placed in tension by the expansion control material placed therein and the expansion control material is placed in compression.

Abstract: A device for holding measurement instruments (2), in particular interferometers, is formed from a plurality of structure elements (4, 5, 6, 7) connected to one another and made from at least one material. The at least one material has a very low coefficient of thermal expansion &agr;. The structure elements (4) on which the measurement instruments (2) are arranged are secured between at least two structure side parts (5) in such a way that the thermal expansions of the structure side parts (5) and of the connections (3) have no effect in the measurement direction of the measurement instruments (2).

Abstract: A joint assembly for coupling a ceramic member to a metal member is comprised of a ceramic shaft portion attached to the ceramic member; a slotted shrink fitter formed of a first metal and disposed around and in torque transmitting contact with the ceramic shaft portion to define a first interface surface therebetween; and a sleeve formed of a second metal disposed around and in torque transmitting contact with the shrink fitter to define a second interface surface therebetween. Either the shrink fitter or the sleeve attached to the metal member. The coefficient of thermal expansion of the second metal is relatively low compared to that of the first metal and the diameters of the first interface, (d1), and the second interface, (d2), are determined from the equation, d1/d2=(&agr;c−&agr;1)/(&agr;2−&agr;1) where &agr;c, &agr;1 and &agr;2 are the coefficients of thermal expansion of the ceramic, the first metal and the second metal respectively.

Abstract: A method is described for installing a stud to extend above a surface of a composite portion of a tank or other structure subject to the pressure of cryogenic fluid, so that another structure can be attached to the stud. The method includes drilling a through aperture at the location of the stud, and installing a threaded insert near the outer surface of the aperture, if not already installed. A metal bolt having a CTE less than that of the composite material is selected. The bolt has an unthreaded shank portion and a threaded portion. The length of the bolt exceeds the length of the projecting stud and the thickness of the composite. The bolt is assembled with a commercial k seal, a collar having a CTE much less than that of the bolt, and another k seal. The seals mate with corresponding frustoconical surfaces of the composite and of the collar, and when the bolt is properly torqued to a preload, prevent leakage.

Abstract: A coupling with a tribological system that can withstand temperatures up to 600° C. The coupling includes a shaft having an outer surface with a layer of chromium and a sleeve for receiving the shaft. The sleeve has an inner surface with a layer of silver or gold. The silver or gold layer contacts the chromium layer to form the tribological system.

Abstract: A method is described for installing a stud to extend above a surface of a composite portion of a tank or other structure subject to the pressure of cryogenic fluid, so that another structure can be attached to the stud. The method includes drilling a through aperture at the location of the stud, and installing a threaded insert near the outer surface of the aperture, if not already installed. A metal bolt having a CTE less than that of the composite material is selected. The bolt has an unthreaded shank portion and a threaded portion. The length of the bolt exceeds the length of the projecting stud and the thickness of the composite. The bolt is assembled with a commercial k seal, a collar having a CTE much less than that of the bolt, and another k seal. The seals mate with corresponding frustoconical surfaces of the composite and of the collar, and when the bolt is properly torqued to a preload, prevent leakage.

Abstract: A chuck for the clamping of tools by shrink fit includes a chuck member which has a longitudinal section having a central receptacle with clamping surface for the insertion and holding of the tool to be clamped with its shank. The longitudinal section includes a plurality of segments arranged at distances from one another in the circumferential direction and separated from each other by clearances in between, the segments extending essentially axially parallel and forming the clamping surface with their inner peripheral areas. The segments are surrounded on the outside by a sleeve part. The segments are either in one piece with the sleeve part or, as separate structural elements, are a component of a mounted insert.

Abstract: A coupling with a tribological system that can withstand temperatures up to 600° C. The coupling includes a shaft having an outer surface with a layer of chromium and a sleeve for receiving the shaft. The sleeve has an inner surface with a layer of silver or gold. The silver or gold layer contacts the chromium layer to form the tribological system.

Abstract: A clamping chuck for clamping tools by shrinkage has a chuck body provided with a receptacle for receiving a tool to be clamped with a tool shaft and having an end-side abutment surface for the insertable tool so that during insertion a rear-side shoulder of the tool axially abuts against the abutment surface and a ring element and axially supportable against the chuck body in an axial direction and provided with an abutment surface, the abutment surface of the ring element being located forwardly at an end axially adjoining the abutment surface of the chuck body, to be associated with the shoulder of the tool, for axial clamping of the inserted tool by means of the ring element with respect to the chuck body.

Abstract: A steel profile clamp is used to join flanged component parts. The profile clamp has at least partially conical side walls that are bent radially inwardly. The profile clamp has welding joints to maintain the shape of the clamp. The steel is martensitic for increased load-carrying capacity of the joint. The steel material, in an ambient temperature range of 20° C. to 750° C., has a coefficient of thermal expansion that is at least 0.3×10−6 m/mK lower than that of the coefficient of thermal expansion of a ferritic casting material. The method for manufacturing the profile clamp includes prequenching and tempering the material of the profile clamp when it is in the form of a strip. After forming and welding the profile clamp, the weld is subject to induction tempering.

Abstract: A joint assembly for coupling a ceramic member to a metal member is comprised of a ceramic shaft portion attached to the ceramic member; a slotted shrink fitter formed of a first metal and disposed around and in torque transmitting contact with the ceramic shaft portion to define a first interface surface therebetween; and a sleeve formed of a second metal disposed around and in torque transmitting contact with the shrink fitter to define a second interface surface therebetween. Either the shrink fitter or the sleeve attached to the metal member. The coefficient of thermal expansion of the second metal is relatively low compared to that of the first metal and the diameters of the first interface, (d1), and the second interface, (d2), are determined from the equation, d1/d2=(&agr;c−&agr;1)/(&agr;2−&agr;1) where &agr;c, &agr;1 and &agr;2 are the coefficients of thermal expansion of the ceramic, the first metal and the second metal respectively.

Abstract: A joint assembly for coupling a ceramic member to a metal member is comprised of a ceramic shaft portion attached to the ceramic member; a slotted shrink fitter formed of a first metal and disposed around and in torque transmitting contact with the ceramic shaft portion to define a first interface surface therebetween; and a sleeve formed of a second metal disposed around and in torque transmitting contact with the shrink fitter to define a second interface surface therebetween. Either the shrink fitter or the sleeve attached to the metal member. The coefficient of thermal expansion of the second metal is relatively low compared to that of the first metal and the diameters of the first interface, (d1), and the second interface, (d2), are determined from the equation, d1/2=(&agr;c−&agr;1)/(&agr;−&agr;1) where &agr;c, &agr;1 and &agr;2 are the coefficients of thermal expansion of the ceramic, the first metal and the second metal respectively.

Abstract: A method and apparatus for securing prestressed or pressure-containing connections, such as in a pipe clamp, in remote or hazardous locations. A connection, having bolts that are heated and pretensioned, can easily be uniformly tightened with a robotic device.

Abstract: A shrinkage-fit tool holder having a tool holder body 11 having a portion 2 adapted to be connected to a machining center, a manipulator-engaging portion 3, a chuck portion 4 and a tool-holding member 6 for firmly holding a shank of a cemented carbide tool by shrinkage fitting, at least the tool-holding member 6 being made of specialty steel having an austenitic structure that is strengthened by precipitation hardening or work hardening.

Abstract: In an interference fit type cutting tool according to the present invention, a head section and a shank section are fitted together by shrinkage fitting. The shank section is provided with a shaft portion and a taper portion. The head section is provided with a hole portion to be fitted on the shaft portion, and a tapered portion to be fitted on the taper portion. The hole portion and the tapered portion have an interference, and the inner diameters thereof are smaller than the outer diameters of the shaft portion and the taper portion. Two-surface restraint is established by fixing the shaft portion and the hole portion, and the taper portion and the tapered portion with the interference pressure by shrinkage fitting. A key is formed on the leading end face of the shaft portion, a key groove is formed in the bottom face of the hole portion, and the key and the key groove are fitted together.

Abstract: In a friction- and form-grip connection of rotating components (1, 2) which have different expansion behavior in the region of the connection during rotation, the form grip is effected via a stepped centering seat (3). The friction grip between the two components is effected by means of axially prestressed elements. At least one of the components has a cavity (6) in the interior, in which cavity (6) an insert ring (7), which exerts a radial force on the centering seat (3) during operation, is arranged. The prestressed insert ring (7) bears with only part of its axial extent against the component (1) interacting with it.

Abstract: A hermetic glass-to-metal seal between a conductive pin and an outer body, wherein a corrosion-resistant noble metal (e.g., gold) coating is applied to the conductive pin before the hermetic seal is formed. The noble metal-coated conductive pin is located in glass having a softening point less than about 650° C. and disposed in a cavity of the outer body. This is accomplished by inserting the coated conductive pin into a bore in a glass preform, heating the assembly to a temperature in excess of the softening point of the glass but less than about 700° C., and cooling the assembly. The coefficients of thermal expansion of the components of the assembly are preferably selected such that the resulting assembly is a hermetic compression seal.

Abstract: The thread of a first component extends along a thread axis and has a thread structure for meshing engagement into a counterthread of a second component having a counterthread structure, for making a screw connection. The elastic and/or thermal deformation behavior of the first component and of the second component are different from one another. The thread structure is configured with an anticipation of deformation, in order to compensate for an elastic and/or thermal deformation under a predeterminable thermomechanical load, and a cylindrical thread segment of constant diameter. There is provided a thread segment, axially adjacent to the cylindrical thread segment, with a diameter that varies along the thread axis. The thread assembly is utilized in a screw connection for a high application temperatures.

Abstract: A slider washer bearing in a bolted interface assembly allows relative differential thermal expansion and contraction motion between a component plate fastened to a base plate by a bolt, without inducing large strains and stresses upon the plates or the bolt. The slider washer bearing, thereby, functions as a thin spacer between the component and base plates, enabling high preload tightening of the bolted assembly while also enabling relative uni-directional alternating motion of the plates. The slider washer includes at least one mating groove arranged unidirectionally and extending horizontally between the top and bottom flexure plates. The grooves provide a guide for relative alternating back and forth unidirectional motion while the full strength of the bolt remains available to support the component plate without allowing high friction shear forces.

Abstract: A method is used for interfacing materials of dissimilar thermal expansion in an X-ray tube. Initially, a first joint is identified, which has an inner component to be received into an outer component. Typically, the inner component has a higher coefficient of expansion than the outer component, so the purpose of the invention is to reduce the physical expansion of that component in the joint. A plurality of slots is introduced along the approximate axial length of the inner component of the joint, to achieve the aforementioned purpose. Alternatively, a coupling member could be provided between two components, the coupling member having a thermal expansion rate greater than one component and less than the other component.

Abstract: A clip flexure slider washer bearing in a bolted interface assembly allows differential thermal expansion and contraction between a component mounting plate or flange fastened to a base plate by a bolt. The bearing functions as a thin lubricated spacer between the component plate and the base plate, allowing the bolted assembly to be tightened to a high preload while enabling relative sliding motion without inducing large strains and stresses in the plates or the bolt. The slider washer portions of the bearing are sandwiched between the two horizontal parallel portions of the metal clip flexure. A side portion of the clip flexure bent as a right angle to the horizontal portions and extending vertically from one edge constrains the relative sliding motion of the component and base plate to unidirectional alternating back and forth translation, thus preventing lateral motion.

Abstract: A joint between materials having disparate coefficients of thermal expansion (CTE) is compensated by a collar which extends a dimension of that one of the different materials which has the lesser CTE. A set of different collars provides compensation for sheets of material of different thicknesses when used with fasteners of a given material. The joint is assembled by selecting the sheets of various thicknesses to be juxtaposed, applying the fastener with a compensation collar corresponding to each one of the different sheets, and tightening the joint.

Abstract: In a friction- and form-grip connection of rotating components (1, 2) which have different expansion behavior in the region of the connection during rotation, the form grip is effected via a stepped centering seat (3). The friction grip between the two components is effected by way of axially prestressed elements. At least one of the components has a cavity (6) in the interior, in which cavity (6) an insert ring (7), which exerts a radial force on the centering seat (3) during operation, is arranged. The prestressed insert ring (7) bears with only part of its axial extent against the component (1) interacting with it.

Abstract: The invention relates to a composite body which is assembled of at least two bodies. The first body is made of a first material and the second body is made of a second material. Each of the two bodies has at least one connecting surface and these connecting surfaces are mutually adjacent. The two connecting bodies are wrung upon each other on at least one connecting surface. The two connecting surfaces are connected to each other by wringing and on at least one of these two surfaces, one or more recesses are provided for an adhesive location or an adhesive gap. An adhesive ensures an additional adhesive connection of the two connecting surfaces at the adhesive location between the two bodies. These recesses of the adhesive locations lie at least essentially in the wringing surface.

Abstract: A high temperature vapor coating container, including a hollow interior, resists distortion and cracking at a vapor coating temperature of at least about 1700.degree. F. as a result of making the container of a nonmetallic material having a coefficient of thermal expansion of less than about 4.5.times.10.sup.-6 at the vapor coating temperature, the material being nonreactive with the coating vapor at the vapor coating temperature.

Abstract: A ceramic-metal composite assembly includes an intermediate member made of a material having a thermal expansion efficiency between those of the materials forming a ceramic member and a metallic shaft member. The intermediate member is metallurgically joined to the ceramic member whilst being mechanically joined to the metallic member to constitute a single unit.

Abstract: In order to create an adjusting ring for the synchronous alteration of the angle of pitch of guide vanes of a compressor having several bearing points for mounting on a compressor housing of the compressor, which can be manufactured at least partially from materials with a low coefficient of thermal expansion and is, nevertheless, compatible with a metallic compressor housing with respect to temperature, it is suggested that the adjusting ring comprise curved ring segments each arranged between two adjacent bearing points, the curvature of the ring segments decreasing during an increase in the temperature of the ring segments so that the bearing points between the ring segments are displaced outwards in a radial direction.

Abstract: Thermally induced movement between stacked conical, pyramidal "cones" and segments of such cones can be used to provide alarm signals and control the distance between and orientation of objects. Preferably, each of the stacked cones must have a lesser characteristic of thermal change than the cone next most proximate to the base cone.

Abstract: An annular collar includes a first clamping surface to be positioned radially outwardly of a surface of a bearing inner ring. The annular collar is made of a thermoelastic material such that an increase in temperature decreases the circumference of the annular collar and causes the first clamping surface to clamp against the surface of the bearing inner ring. The thermoelastic material may be a shape memory alloy or a polymer.

Abstract: A thermal load relief ring is disposed between the mating surfaces of adjacent cases of a gas turbine engine and secured thereto by a dowel pin or bolt to assure the concentricity of the cases. The bolt and dowel pin are configured to assure the concentric fit of the components. These configurations allow the cases to be fabricated from different materials to allow a lighter and less expensive case.

Abstract: A charge plate fabrication process provides a charge plate assembly having minimal distortion caused by shifts in temperature and humidity. The fabrication process includes the steps of forming a charge plate coupon having a plurality of charging electrodes and electrical connections on an etchable substrate and providing a ceramic charge plate substrate. An adhesive layer is then applied between the charge plate coupon and the charge plate substrate before assembling the charge plate coupon and the charge plate substrate in a fixture. Finally, the assembly is cured in the fixture.

Abstract: A thermal load relief ring is disposed between the mating surfaces of adjacent cases of a gas turbine engine and secured thereto by a dowel pin or bolt to assure the concentricity of the cases. The bolt and dowel pin are configured to assure the concentric fit of the components. These configurations allow the cases to be fabricated from different materials to allow a lighter and less expensive case.

Abstract: The sliding joint assembly for a first part and a second part having different expansion coefficients comprises a plurality of radially-acting spring blades connected firstly at first ends to the first part only in the vicinity of a contact interface, and secondly via second ends to the second part only in a zone that is axially remote from the contact interface, the contact interface constituting a sliding contact interface between the first and second parts while the second ends of the spring blades are connected to the second part by mechanical fasteners constituted by detachable screw-and-nut type assemblies provided with spring washers for damping forces exerted in the axial direction.

Abstract: A shaft (12) is connected to a disc (20) by a coupling which comprises a spigot (14) which extends from the shaft (12) and locates in a recess (22) in the disc (20). At ambient temperature there is an interference fit between the spigot (14) and the recess (22) which maintains alignment of the disc (20) and the shaft (12) so that they rotate concentrically. At elevated temperatures the interference fit loosens and alignment of the disc (20) and the shaft (12) is maintained by a plurality of ridges (27) on the face (25) of a flange (24) on the disc (20). The ridges (27) have a large radial component and engage with the confronting face (17) of a flange (16) on the shaft (12) to prevent lateral movement between the shaft (12) and the disc (20).

Abstract: Device for assembling two elements made of materials having different coefficients of thermal expansion, which are subject in use to substantial temperature variations, is provided with a combination of a layer of a compressible, heat insulating material, positioned between a support element and an attached element, and an mechanism for maintaining the attached element against the layer, and the layer against the support element. The mechanism is arranged so as to enable relative movement between the two elements in a plane substantially parallel to the plane of the layer. Also, surface portions of the attached element in contact with the mechanism are substantially parallel to the plane of the layer, and a material similar to the material of the layer is positioned between the surface portions and the mechanism. The device is especially applicable to the attachment of insulating elements on a metallic structure.

Abstract: An arrangement for concentrically positioning a first part relative to a second part, for example, a casing, or sleeve, (2) relative to a shaft (1), when the parts are made from materials with different coefficients of thermal expansion, provides a radial clearance (4) between the first and second parts. The first part (2) is supported along its length by portions facing radially away from the second part, at an abutment arrangement (7, 8) having the same or similar thermal expansion characteristics as the first part (2). The abutment arrangement (7, 8) is held concentric relative to the second part (1).

Abstract: An angle adjustable grip mounting device including a cylindrical connector fastened to either end of a tubular bicycle handlebar by a short tube and a screw nut by means of the control of an adjusting screw to hold a grip by means of two arched symmetrical clamping plates. The grip has a round head held between two arched clamping plates received inside the cylindrical connector, and retained in position by the two arched clamping plates, which are spaced by an opening on the peripheral wall of the cylindrical connector, are fastened together. The screw nut and the short tube become biased on two opposite sides and firmly retained in the tubular bicycle handlebar as the adjusting screw is turned clockwise to move the screw nut toward the short tube.

Abstract: A plate for spreading bolt loading around the horizontal joint flanges of a turbomachine, such as a steam turbine, is provided. The plate is contoured so that its surface area substantially matches that of the surface of the steam turbine flange against which the compressive load associated with the joint bolt preloading is applied. The plate is disposed between the flange and the nuts on the joint bolts and is made from a high yield strength material so that the locally high stresses under the nuts do not cause creeping or yielding of the plate. The plate serves to distribute the compressive joint loading around the entire surface of the flange, thereby eliminating the locally high compressive stresses that can cause creep and yielding in the flange. Spherical counter bores are machined in the plate bolt holes and spherical washers are installed between the plate and the nuts so that misalignment of bolt holes does not cause the nuts to impose bending forces on the bolts.

Abstract: The invention provides an improved combined body of ceramics and metal which maintains high anti-torsional strength and anti-slip off strength while stress concentration is relaxed and deterioration of the ceramics is well prevented. The combined body includes a ceramic member inserted into and firmly engaged with a recess or an opening of a metal member. The combined body has a treated surface region in the vicinity of an engagement end of a contact surface of either the ceramic member or the metal member, and an untreated surface region at a location other than the vicinity of the engagement end.

Abstract: A mechanism (100) for fixing the relative position of two members including a first member (104) having a first coefficient of thermal expansion and a second member (102) positioned adjacent to the first member and having a second coefficient of thermal expansion. The first member (104) is adapted to receive thermal energy. The first and second members are mounted for relative motion therebetween at a first temperature and are in contact at a relative fixed position at a second temperature. In a specific embodiment, a microwave control valve (100) for use in a waveguide is disclosed and includes a housing (104) having a first coefficient of thermal expansion and a first plurality of housing waveguide openings (130). A rotor (102) is positioned within the housing and has a second coefficient of thermal expansion and a plurality of rotor waveguide openings (132). The housing (104) is adapted to receive RF energy.

Abstract: First and second annular clamping elements are coupled together by an annular clamping ring and a Belleville spring coupled to the clamping ring urges the clamping elements toward each other so that they grip the annular ceramic piece without the need to utilize fasteners which would call for the machining of the annular ceramic piece to weaken it. The clamping elements thus support the ceramic piece and can couple it to an annular gas turbine machine frame or the like.

Abstract: An attachment fitting for securing metal structures to carbon-carbon structures which tightens as temperature increases. The fitting is particularly useful in high temperature aerospace applications such as hypersonic aircraft. The fitting basically connects an upstanding carbon-carbon blade on a carbon-carbon structure to a metal clevis which fits snugly thereover. A ceramic bushing is fitted in a transverse hole in the blade. A transverse bolt hole extends through the clevis and bushing. A bolt in the bolt hole is tightened with one or more nuts to tightly press the clevis against the busing and blade. The bolt and nut material is selected to have a lower coefficient of thermal expansion than the clevis so that differential thermal expansion between clevis and bolt keeps the joint tight at elevated temperatures.

Abstract: A metal valve stem is attached to a ceramic valve plug. An elongated metal screw member has an expandable section securely wedged into a cavity in the plug as the attached screw/ceramic plug are threadably tightened on the valve stem. A first pre-wedging step presses an expander on the screw to fully bend the expander inside the ceramic cavity. The second wedging step during tightening of the screw/plug on the stem ensures uniform loading of the expander on the ceramic cavity surfaces.

Abstract: A method of bonding at least two members having different coefficients of thermal expansion is disclosed, wherein an edge of a bonding interface between the members is positioned in a tapered portion, thereby bridging one member having a smaller coefficient of thermal expansion and another having a larger coefficient of thermal expansion. A bonded composite article comprising such bonded members having the different coefficients of thermal expansion is also disclosed.

Abstract: Joined structures are disclosed, which each comprise first and second members having different coefficients of thermal expansion and an intermediate member. The first and second members are joined together through the intermediate member. The intermediate member has yield stress smaller than those of the first and second members, and a tapered portion is formed at an outer peripheral surface of the intermediate member such that the tapered portion has a variable cross-sectional area orthogonal to an axis of the joined members. The area is larger at one end of the tapered portion near one of the first and second members having a smaller coefficient of thermal expansion than the area at the other end of the tapered portion near the other one of the first and second members having a larger coefficient of thermal expansion. A method of joining such first and second members having different coefficients of thermal expansion through the intermediate member is also disclosed.

Abstract: A jointing structure of a rotor and a shaft has a rotor made of aluminum alloy having a through-hole at a center thereof, and a shaft made of steel which is to be press fitted into the through-hole of the rotor, the shaft being formed at least at a part of a surface to be jointed with the through-hole of the rotor with a hump and valley portion along an axis thereof, the outer diameter of the hump portion being larger than the inner diameter of the through-hole, the hump and valley portion of the shaft being press fitted into the through-hole of the rotor.

Abstract: A joint for connecting a tip member to the end of a rod or shaft. The joint is particularly useful for joining a rod end to a tip member of a material which is not easily brazed, cemented or otherwise adhesively joined together. In the specific example described, a ceramic tip is jointed to the end of a metal rod, such as in a plug, a globe, or sliding stem valve. A cavity in the interior of the tip member has a narrowed opening at its top which terminates at a flat surface of the tip member. A pair of wedge members, each of about 180 degrees annular extent, and the headed bolt end are all located in the cavity, with the wedge members oppositely positioned around bolt head. The bolt head and wedge members have complementary tapers so that motion of the bolt away from the tip member cavity causes the wedge members to move radially away from each other and preferably contact the side wall of the cavity, with the cavity being partially closed by an annular overhang through which the bolt shank passes.