Abstract: A thermally decomposable polymer composition comprising a polyester of a dicarboxylic acid and a tertiary cyclohexanediols of Formulae V and VI are disclosed, which are useful in the forming of microelectronic assemblies: a representative example of a dicarboxylic acid is an oxalic acid and representative example of thermally decomposable polyester is the polyester of the formula: wherein m is at least about 100.

Abstract: A calibration tool includes a calibration tip. The calibration tool may be for a welding training system or some other welding system. The calibration tool also includes a first marker disposed a first distance from the calibration tip and a second marker disposed a second distance from the first marker. The second distance is adjustable during calibration.

Abstract: A fixture assembly for welding a plurality of stator wire end pairs may include an anvil, a movable clamp configured to translate between an unclamped state and a clamped state, a first grounding electrode, and a second grounding electrode. The movable clamp may be configured to urge the plurality of stator wire ends against the anvil when in the clamped state. The moveable clamp includes a separator feature that generally extends toward the anvil. Each of the first grounding electrode and second grounding electrodes may be configured to translate between a clamped state and an unclamped state. When in the clamped state, each of the first and second grounding electrodes is configured to urge a pair of the plurality of stator wire end pairs against the separator feature.

Abstract: A method is provided for in-situ resurfacing of a main rotor shaft of a wind turbine, wherein in an operational state, the main rotor shaft is coupled at a first end to a rotor hub and at the opposite second end to a gearbox or directly to a generator within a nacelle. The method includes uncoupling the rotor shaft from the gearbox or generator so as to expose an end face of the second end of the rotor shaft. A fixture is attached to the exposed end face concentric with the rotational axis of the rotor shaft. A lathe system in then attached to the fixture. The rotor shaft surface adjacent to the exposed end is machined with the lathe system such that the resurfaced portion of the rotor shaft surface is brought to a round state concentric with the rotational axis of the rotor shaft. The method is conducted within the nacelle with the first end of the rotor shaft remaining coupled to the rotor.

Abstract: A method for assembling a camshaft from a support shaft and components to be connected to the support shaft, the components having through-openings for receiving the support shaft. In this method, a support shaft is provided, having first diametrical enlargements in first regions, in which the components are to be secured, and second diametrical enlargements in second regions, in which the components are to be pre-positioned. A diameter (D2) in the second regions is smaller than a diameter (D1) in the first regions The support shaft is cooled and/or the components are heated up, so that the support shaft can be pushed with its first and second diametrical enlargements through the through-openings of the components.

Abstract: A method of mounting a capacitor to a bracket is provided. The method includes the step of providing a capacitor with an outer shell, a capacitor member disposed within the shell and a conductor member disposed within the outer shell and thermally coupled to the capacitor member. A collet is arranged having a first opening sized to slidingly engage the conductor member. A sleeve is provided having a second opening sized to receive a first end of the collet. The collet is slid onto the conductor member. The collet is pressed into the sleeve.

Abstract: A method for machining a metallic member to provide a finished appearance uses a lathe and a scraping process. A metallic member comprising a top portion and a peripheral sidewall is provided, the metallic member is positioned on the worktable. The worktable is rotated with the metallic member, the lathe tool moved backwards and forwards to machine the top portion of the rotary metallic member circumferentially. The lathe tool is moved by the moving device along a predetermined path relative to the worktable to machine curved surfaces of the top portion of the metallic member. The scraping cutter is moved to contact the peripheral sidewall of the metallic member. The scraping cutter is moved along a predetermined path, and the scraping cutter is fed the metallic member to achieve the required shape and finish.

Abstract: An aluminum pickup bed is assembled from a stamped headboard, a stamped floorpan, and a roll formed front sill. The headboard, a floorpan flange extending downwardly from the floorpan, and a front wall of the front sill form a three piece sandwich structure. Flow drilled screws are installed into the sandwich structure from the headboard side. The front sill includes a closed front flange and an open rear flange, each of which is welded to the floorpan.

Abstract: A method of charging a hollow valve with metallic sodium includes providing a workpiece, as a semi-finished product for a hollow poppet valve, in which a cavity has an upward opening at a free end of a valve stem at a working position; inserting a nozzle into the opening to feed an initial inert gas into the cavity by jetting the inert gas from the nozzle; moving up the nozzle to put a holder between the workpiece and the nozzle, the holder holding a rod-like metallic sodium; and inserting the nozzle into a first end of the holder while an additional inert gas is jetted into the cavity from the nozzle to push down the rod-like metallic sodium along with the inert gas from a second end of the holder into the cavity of the workpiece.

Abstract: A tire mounting method is provided for automatically mounting a tire onto hub bolts of a motor vehicle. The method includes gripping the tire and temporarily tightening nuts on the hub bolts on which the tire has been placed with a first working mechanism. The nuts that have been temporarily tightened by the first working mechanism are fully tightened with a second working mechanism, which is disposed in association with a first mounting region on a front wheel side or on a rear wheel side of the motor vehicle. The nuts that have been temporarily tightened by the first working mechanism are fully tightened with a third working mechanism, which is disposed in association with a second mounting region on the rear wheel side or on the front wheel side of the motor vehicle.

Abstract: A tire mounting apparatus is constructed from a first working mechanism and a second working mechanism that are separate from each other. The first working mechanism is provided with a tire holding device for holding a tire and with a temporary tightening device for temporarily tightening nuts onto hub bolts to which the tire is mounted. The second working mechanism is provided with a final tightening device means for finally tightening the temporarily tightened nuts. The final tightening device includes two nut runners and an interval adjuster for adjusting an interval between the two nut runners.

Abstract: A reinstalling method which, when reinstalling an object to be supported, precisely restores the object to an initial installing state in a short period of time without requiring special skills. In a state before supporting of an object to be supported by support tools is released and in each of states in which the supporting is sequentially released, load acting on at least one support tool selected from among the support tools being in a supporting state is obtained. When reinstalling, the object is sequentially supported at the same positions as those before the release by the support tools in the reverse order to that of the release, and, a vertical-direction supporting position of each support tool is adjusted so that a load cell of the selected support tool detects the same value as the load obtained in the supporting state before the support tool was released.

Abstract: An elongated support frame carrying a jig at a first section of the support frame. The jig receives a plurality of picket and rail fencing members in a pre-defined arrangement for assembly. A plurality of swedge guns are mounted to a gun platform. The gun platform is carried at a second section of the support frame so that distal ends of the swedge guns are aligned with a receiving section of the jig. At least one of the jig and the gun platform is slidable along the support frame so that the swedge guns are received into hollow interiors of the picket fencing members and repositionable along the length of the picket fencing members. The swedge guns are operable to form an indentation on an interior surface of the picket fencing members causing an interlocking engagement with one of the rail fencing members.

Abstract: The instant invention relates to a method for assembling a device for the manufacturing patterns in layers. The method includes attaching a build module to a casing. The build module includes a spreader device and a dispensing device mounted above a mounting platform. The build module preferably includes a build platform mounted below the mounting platform. For example, the build module may be attached to the casing by screwing the mounting platform to the casing.

Abstract: A sliding seat device with surrounding structure, which is applied to a bridge type machining center, includes a main body provided with a sliding portion; a sliding seat slidingly disposed on the sliding portion and reciprocating along an X-axis direction of the main body, the sliding seat provided with a housing; a sliding pillar passing through the housing and reciprocating along a Z-axis direction of the main body, one side of the sliding pillar provided with a protruding rail disposed along the Z-axis direction of the main body; an assistant plate connected with the sliding seat and facing the protruding rail; and an adjusting unit passing through the assistant plate and pushing against the protruding rail, the adjusting unit correcting a vertical bias between the sliding pillar and the main body.

Abstract: The invention provides an adapter for a dental milling block holder with a dental milling block (52 and 54) or dental grinding block, which is attached to a dental milling block holder, in particular glued on, wherein the dental milling block holder is provided with a round shank which is mounted in the adapter (40). It is characterized in that the adapter (40) is provided with at least one internal thread (92) for the mounting of a fastening screw (31) which acts on the shank, to which fastening screw (31) inside the shank mount of the adapter (40) of the fastening screw (31) positioned opposite of it, at least one in particular elevated, in particular at least two elevated clamping surfaces (74 and 76) are formed against which the shank abuts.

Abstract: A track control apparatus includes an interpolation/acceleration and deceleration calculating unit that interpolates a commanded route and calculates a post-acceleration and deceleration interpolation route, an axis distributing unit that generates a position command for each movable axis from the post-acceleration and deceleration interpolation route, a servo-response calculating unit that calculates a servo response to the position command, a tangential-direction-servo-response calculating unit that obtains a tangential direction servo response from the post-acceleration and deceleration interpolation route, a reference-point generating unit that obtains a reference point from the tangential direction servo response, a position-vector correcting unit that corrects the position command for each movable axis to output a post-correction position command for each movable axis, and a servo control unit that outputs motor driving torque such that each movable axis follows the corresponding post-correction positio

Abstract: A tool changer comprises a turret with a plurality of grips for holding tools such that the turret is turned to index a desired tool to change the tools. The front and rear surfaces of the turret are covered by front and rear covers, respectively. A projection or a recess which defines a passage for cutting fluid is formed in an outer rear surface portion of the rear cover at portions above and/or on each lateral side of a turret mechanism portion.

Abstract: A grinding apparatus for grinding a floor, the apparatus comprising a body having a travelling mechanism which enables the body to travel across a floor while the apparatus is grinding; a first grinding head incorporating at least one grinding tool and having an operable configuration in which the first grinding head is able to grind a first floor portion; and a second grinding head incorporating at least one grinding tool and having an operable configuration in which the second grinding head is able to grind a second floor portion; wherein the first and second grinding heads are mountable to the body whereby their positions relative to the body are able to be varied.

Abstract: The present disclosure relates generally to a machining tool and method for using the machining tool. The machining tool includes a machining arm including a first arm section, a second arm section, a proximate end, a distal end, and a machining arm longitudinal axis, a belt disposed around the machining arm; and a first motor operably coupled to the machining arm, wherein at least a portion of the machining arm is configured to pivot such that an angle is formed between the distal end and the machining arm longitudinal axis. The method includes the steps of placing the pivotable machining arm in a first orientation, inserting the pivotable machining arm in the desired location, determining whether the belt is in a desired position relative to the raised surface, operating the motor to rotate the belt around the pivotable machining arm, and placing the belt in contact with the raised surface.

Abstract: A polishing apparatus includes: a polishing table 12 for holding a polishing pad; a first electric motor 14 that rotationally drives the polishing table 12; a first rotary joint 40 that has a rotating body 41 that is rotationally driven by the first electric motor 14, a housing 42 provided around the rotating body 41, and a seal portion 44 that seals between the rotating body 41 and the housing 42; a second current sensor 31 that detects a current which is correlated with driving load of the first electric motor 14; a friction detecting unit 50 that detects sliding friction in the seal portion 44 of the first rotary joint 40; and an end point detecting apparatus 60 that detects a polishing end point of the polishing target on the basis of the current and the sliding friction.

Abstract: A grinder for grinding an end face of a fiber includes a housing, a fiber fixing module, a base, a transmission shaft, and a grinding pad. The housing includes an annular rack wheel with an internal engaging teeth. The fiber fixing module is positioned on a top of the housing. The base is positioned at a bottom of the housing and includes an eccentric connection portion. An end of the transmission shaft is connected to the connection portion. The transmission shaft is sleeved with an annular pinion having external engaging teeth engaging with the internal engaging teeth. The grinding pad is connected to another end of the transmission shaft and revolves around the rotation axis of the base and rotates around its own rotation axis together with the transmission shaft and matches an end face of a to-be-ground fiber penetrating the fiber fixing module.

Abstract: Method for compensating temperature-induced deviations in a grinding machine includes controlling the movements of the dressing tool relative to the grinding tool in order to relatively move the dressing tool towards the grinding tool; checking whether a first-cut detection signalizes a contact of the grinding tool and the dressing tool; repeating the controlling and checking steps until a contact between the grinding tool and the dressing tool is detected, and when the contact is detected, then (i) recording the Current Position, and (ii) carrying out a compensation calculation using the Current Position and a reference position.

Abstract: An upper shield and a lower shield may be coupled to a rotor for polishing airfoils of the rotor in a vibratory bowl. The upper shield and the lower shield may include spars. The spars may correspond to leading edges and trailing edges of the airfoils. A media including abrasive particles may be flowed through the rotor in the vibratory bowl. The spars may protect the leading edges and trailing edges of the airfoils from excessive material removal by the abrasive particles.

Abstract: A clean toggle clamp is configured to operate without creating excessive debris. The clean toggle clamp includes a base; an arm rotationally coupled to the base via a first bearing isolated rod; a clamping element; a handle is rotationally coupled to the arm via a second bearing isolated rod. The handle includes a revolving latching pin and a linkage rotationally coupled on a first end to the handle via at least one third bearing isolated rod and on a second end to the base via a fourth bearing isolated rod. The toggle clamp includes a secondary latch rotationally coupled to the base and configured to engage the revolving latching pin to inhibit movement of the handle and arm. The handle, arm, linkage and secondary latch are configured to rotate without a frictional sliding of any of surface of the arm, the handle, the linkage or the base.

Abstract: This disclosure generally pertains to various accessories for use with bar clamps to enhance the capabilities and functionality of the bar clamps. The accessories described in detail herein include removable and replaceable bar clamp attachments, bar extenders, and stability stands for use with a bar clamp.

Abstract: A one-way wrench having a catching device with two catches and a catch holder and having differential teeth is provided and characterized in that: the catching device is disposed in a catching chamber laterally disposed beside a driving hole of the one-way wrench; the catching device has two catches, two position-restoring elements, and a catch holder; the catch holder pushes the two catches simultaneously, such that a single stable base structure pushes the two catches simultaneously; and starting ends of tooth portions of the two catches are dentate to different extents, so as to effectuate a small transmission-oriented tooth-changing angle, achieve stable control, as well as cut production and maintenance costs.

Abstract: A dual-setting rotating system selectively provides unidirectional rotation to a drive shaft. Along with the drive shaft, the system includes a primary ratchet gear fixedly disposed on the drive shaft and configured to motivate the drive shaft in principal rotation. A secondary ratchet gear is coaxial with the primary ratchet gear and rotatably attached about at least a portion of the drive shaft. A pinion gear is axially-aligned with the drive shaft and operably engaged with the secondary ratchet gear and a shaft gear to motivate the drive shaft during retrograde rotation. The shaft gear is rigidly attached to and coaxial with the drive shaft. A clutch plate spans the primary and secondary ratchet gear while a main body encloses at least a portion of the clutch plate.

Abstract: A mandrel is disclosed for securely holding a screw bit during use, but allowing easy removal of the screw bit for replacement. The mandrel includes a socket having a chamber housing a locking mechanism such as a split-ring. The mandrel further includes a release mechanism such as one or more ears for moving the locking mechanism from a first position where the screw bit is held within the socket and a second position where the screw bit may be removed from the socket.

Abstract: A socket release assembly for a ratchet drive or ratchet wrench that includes a ratchet gear housing, a ratchet head connected to the ratchet gear housing, a push button disposed within the ratchet gear housing and the ratchet head with a portion extending through an opening in the ratchet gear housing, a channel lock disposed within the ratchet gear housing above the ratchet head, a ball lock disposed within the ratchet head and in mating contact with the push button, a ball bearing disposed within the ratchet head between the ball lock and a ball bearing opening in the ratchet head, a release pin within the ball lock and in mating contact with the channel lock where sliding of the release pin causes the channel lock to be slidably positioned allowing the push button to be depressed into ratchet gear housing.

Abstract: The present invention relates to detaching equipment for detaching an electronic device and a detaching method thereof. A base of the detaching equipment comprises a bearing groove for bearing the electronic device. The first fixing unit and the second fixing unit are disposed at the base. A fixing member of the first fixing unit is capable of moving along a first direction to fix a housing of the electronic device. A protruding portion of the fixing member faces the bearing groove. A baffle of the second fixing unit moves along a second direction to be inserted between a motherboard and a battery unit. At least one lifting portion of a pry bar is provided with an arc. The arc of the lifting portion fits the battery unit of the electronic device, and the pry bar abuts against the protruding portion to lift and detach the battery unit.

Abstract: A puller for pulling an element, such as a pulley or seal, from an assembly to which it is fitted. The puller generally includes a central body having a longitudinal axis, an adjustment ring threaded on the body for moving longitudinally with rotation, slide followers coupled to the ring and moving longitudinally with ring rotation, a plurality of leg assemblies, each including a foot and two legs pivotly attaching the foot to the body so as to form a parallelogram, and a arm pivotly connecting each slide follower to a leg assembly for expanding or contracting the leg assembly. Each foot has one or more foot flanges, each with an engagement surface for engaging with the element to be pulled; the orientation of the engagement surfaces being predetermined so as to not disengage from the element and to provide uniform pull and minimum pressure.

Abstract: A multi-function car charger comprises a housing, a first electrode, a PCB board, a second electrode and a power output port. The car charger further includes a safety hammer, a rear end of safety hammer which is fixed in the housing. The car charger, the safety hammer and other accessories are integrated as a whole to reduce the quantity of car accessories and reduce the occupied space of the car accessories. The safety hammers is placed at a car charger socket where a cigarette lighter is easy to take, thereby attaining the convenience of use.

Abstract: A multipurpose tool system that can be assembled into multiple configurations by a user. The tool system may comprise a plurality of components, including tool heads, shaft segments, and handle ends. The components of the tool system can be combined in various configurations to provide different functions, at different lengths. Connectors may be utilized to connect the various components of the system using a twist lock mechanism. The connectors may include a tubular sleeve member having a biased locking shaft that interacts with a locking groove.

Abstract: A work stool includes a support whose one end has a cushion and an opposite end has a base. The base has a bottom provided with a plurality of casters. The support has a gas strut. A tray is mounted around the support and positioned between the cushion and the base. A connecting assembly has one end fixedly connected to the tray and has an opposite end connected to the gas strut so that a distance between the tray and the cushion is fixed and the tray is adjustable in terms of altitude by operating the gas strut.

Abstract: A tool holder includes a rack and at least one seat connected to the rack. The seat includes an assembling portion and an attached portion spaced from the assembling portion. The assembling portion is detachably mounted to the rack. The attached portion includes an abutted face and a recess. The abutted face is located opposite to the rack. The recess is located between the abutted face and the assembling portion. The recess receives a magnet adapted to magnetically attach to a metal object.

Abstract: Particularly the present invention will allow a detail and precise contour reading and contour marking on surfaces with sharp angles, angles, curves or any difficult shapes, in particular the present invention pertains generally as a mechanism for patented tool: TOOL, METHOD AND MARKING SYSTEM, Canadian Patent No. 2,625,566, U.S. Pat. No. 8,127,457 B2. As the level of difficulty during the wood flooring/tile installation around curved and/or off angle surfaces arises, and there are limited number of workers who can perform such trade, the MECHANISM FOR TOOL, METHOD AND MARKING SYSTEM, will enable anyone who is familiar with the trade to perform the complicated assignment in a shorter period of time and without waste of material; moreover, it will allow performers to acquire the precise craftsmanship results.

Abstract: Robotic systems according to the invention include a frame or body with two or more wheels rotatably mounted on the frame or body and a motor for independently driving each wheel. A system controller generates a signal for actuating each motor based on information provided by one or more sensors in communication with the system controller for generating feedback signals for providing reactive actuation of the motors for generating one or more functions selected from the group consisting of forward motion, backward motion, climbing, and balancing. A power source is included for providing power to operate the drive motors, system controller and the one or more sensors.

Abstract: An articulating probe, comprises a first mechanism including a first link comprising a first longitudinal axis, a first articulation surface and a first motion-limiting element; and a second link comprising a second longitudinal axis, a second articulation surface and a second motion-limiting element. An articulation joint comprises the first articulation surface and the second articulation surface and constructed and arranged to allow two degree-of-freedom articulation of the second link relative to the first link. A motion resisting assembly comprises the first motion limiting element and the second motion limiting element, wherein the motion resisting assembly is constructed and arranged to resist rotation of the second link about the second longitudinal axis relative to the first longitudinal axis of the first link.

Abstract: A piezoelectric driving device includes: a piezoelectric vibrating body which includes a plurality of piezoelectric elements each formed of a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode, and is disposed at least one surface of the first surface and the second surface of the vibrating plate, wherein the plurality of piezoelectric elements are connected in series.

Abstract: An article handling device includes: a gripper that grips an article; a driver that moves the gripper; an article recognition unit that recognizes a state of the article; a gripping recognition unit that recognizes a gripping state of the gripper; a determination unit that determines whether the gripping state is stable or unstable based on a recognition result of the gripping recognition unit; and a controller that controls a first gripping operation in which the gripper grips the article by a gripping position determined based on the recognition result of the article recognition unit, and, when the gripping state is determined as unstable, controls a second gripping operation in which the gripping position is changed and the gripper re-grips the article.

Abstract: Robotic control systems and methods may include providing an end effector tool of a robotic device configured to perform a task on a work surface within a worksite coordinate frame. Unintended movement over time of the end effector tool with respect to the work surface and with respect to the worksite coordinate frame may be determined based on image data indicative of the work surface, first location data indicative of a first location of the end effector tool with respect to the worksite coordinate frame, and second location data indicative of a second location of the end effector tool with respect to the work surface. One or more control signals for the robotic device may be adjusted in order to counteract the unintended movements of the end effector tool with respect to the work surface and worksite coordinate frame.

Abstract: A robot includes a plurality of joints including a first joint and a second joint that rotates in a direction different from a rotation direction of the first joint, a plurality of arm members including a first arm member provided to be rotatable with respect to a base via the first joint, and a first angular velocity sensor provided in the first arm member or the first joint. A first inertial sensor is provided in the first arm member (or a portion that rotates together with the first arm member in the first joint). The plurality of joints are controlled on the basis of an output of the first inertial sensor.

Abstract: A user interface device of a remote control system for a robot and a method using the same are provided. The user interface device includes: a radio frequency (RF) unit for receiving, from a remote control robot, camera data and at least one sensor data detecting a distance; a display unit having a main screen and at least one auxiliary screen; and a controller having an environment evaluation module for determining whether the received camera data are in a normal condition, and having a screen display mode change module for displaying, if the received camera data are in a normal condition, the camera data on the main screen and displaying, if the received camera data are in an abnormal condition, the sensor data on the main screen.

Abstract: A visuo-haptic sensor is presented which uses a deformable, passive material that is mounted in view of a camera. When objects interact with the sensor the deformable material is compressed, causing a change in the shape thereof. The change of shape is detected and evaluated by an image processor that is operatively connected to the camera. The camera may also observe the vicinity of the manipulator to measure ego-motion and motion of close-by objects. The visuo-haptic sensor may be attached to a mobile platform, a robotic manipulator or to any other machine which needs to acquire haptic information about the environment.

Abstract: A hand at a robot arm leading end is provided with a mounting portion for a finger. The mounting portion includes a guiding unit that guides a supported portion of the finger so as to enable the supported portion to pass through from one end part of the guiding unit 31 to another end part thereof. The mounting portion further includes a lock mechanism. The lock mechanism moves the supported portion from any of end parts of the guiding unit 31 toward a mount position between the end parts, to thereby bring the supported portion of the finger into a restricting state at the mount position. Moreover, the lock mechanism moves the supported portion toward any of the end parts from the restricting state, to thereby bring the supported portion from the restricting state into a releasing state.

Abstract: A robot includes an nth arm (n is a natural number), an (n+1)th arm rotatably supported with respect to the nth arm, and a connection destination selection part that can select a connection destination of a cable routing present inside of the nth arm from a cable routing present outside of the nth arm and a cable routing present inside of the (n+1)th arm.

Abstract: A carrier plate assembly has a carrier plate and multiple gaskets. The carrier plate has a first end, a second end, and a carrier surface between the first end and the second end. The carrier surface forms multiple accommodating recesses. The gaskets are accommodated in the accommodating recesses. The gaskets prevent the wafer from sliding. Besides, with top surfaces of the gaskets aligning with the carrier surface and an edge of each gasket connected to an edge of an opening of the accommodating recess, the accommodating recess is filled by the gasket, and thus the gasket is securely accommodated in the accommodating recess and may not deform upward.

Abstract: The invention provides a system for preventing fluid exchange between the interior and exterior of containment enclosures such as process-, hazard-, and research-enclosure systems generally, gloveboxes, containment systems, isolation systems, confinement systems, cleanrooms, negative air systems, and positive air system areas while simultaneously providing material transfer into and out of the enclosures. The invention also provides a method for transporting material into or out of a containment structure.

Abstract: A joint for a cutting tool includes a bolt with a head in a first end, with a thread in a second end, and with an intermediate section between the first end and the second end, which during attachment of two objects rotatably to each other protrudes trough openings in said objects. A nut is received on the thread. In order to provide an easy solution for adjusting the tension of the joint and at the same time preventing accidental loosening of the joint, the bolt is provided with a cavity. An expansion bolt with a threaded end protrudes into the cavity and expands the second end of the bolt.