A circuit breaker is provided which can be filled with a quenching gas and which has two contact arrangements, which can be moved relative to one another and along a longitudinal axis of the circuit breaker. The contact arrangements form a arcing contact system and a rated current contact system connected electrically in parallel with it. One of the contact arrangements includes inner rated current contacts and outer rated current contacts of the rated current contact system, where the inner rated current contacts overhang the outer rated current contacts in the direction of the longitudinal axis, and the outer rated current contacts coaxially surround the inner rated current contacts. The circuit breaker has a high current carrying capability as well as a reliable switching-on and -off behavior, such as during and after the occurrence of a short-circuit current in the circuit breaker.

A spout assembly is provided. The spout assembly includes a spout and a spout base. The spout base has a cross-sectional area that is smaller than a spout sized to enclose an electrical switching apparatus electrical coupling. That is, the spout base includes a CT support surface with a cross-sectional area that is smaller than the spout cross-sectional area. Current transformers are disposed upon the spout base CT support surface.

Disclosed is a switchgear including: a vacuum chamber; a fixed electrode having a fixed contact at an end thereof, the fixed contact being disposed within the vacuum chamber; a movable electrode having a movable contact at an end thereof, the movable contact being disposed within the vacuum chamber; a linkage assembly electrically connecting or disconnecting the movable electrode and the fixed electrode; an engaging coil spring; and a disengaging coil spring. The engaging coil spring and the disengaging coil spring are provided such that centers of the diametric directions thereof are substantially coaxial and at least a part of the engaging coil spring and a part of the disengaging coil spring overlap each other.

A driver for a switch in a GIS (Gas Insulation Switchgear) includes a motor, a shaft connected with a moving contact of the switch, a gear connected with one terminal of the shaft and configured to transfer power of the motor to cause the shaft to reciprocate the moving contact through the shaft, a cam spline combined with the shaft and spaced apart from the gear, and a micro-switch connected with the cam spline and configured to control an operation of the motor.

Disclosed are a power transmission device for a vacuum interrupter, and a vacuum breaker having the same. The device includes: a driving link coupled to an adjuster; a driven link coupled to a movable electrode of a vacuum interrupter; connection links configured to connect the driving link and the driven link with each other, and coupled to the driving link and the driven link such that an interval between the driving link and the driven link is varied; cams coupled to the connection links in a perpendicular direction; and cam guides having guide recesses for slidably coupling the cams, and configured to guide the interval between the driving link and the driven link to be changed.

The invention relates to a medium voltage switchgear assembly which comprises at least one disconnector and whose drive unit is disposed inside or outside a gas chamber according to the generic part of claim 1. In order to further develop a switchgear assembly of the generic type so as to render the same more compact and more functional, the disconnector is embodied as a three-position vacuum chamber switch.

The switchgear includes a vacuum circuit breaker that is disposed in a circuit breaker chamber compartmented by a grounded metal plate, a busbar that is disposed in a busbar chamber and connected to the vacuum circuit breaker through a conductor, a cable that is disposed in a cable chamber and connected at one end to a load side, and a grounding device that is operated by a grounding device actuator disposed in a grounding device actuator chamber, connected to the vacuum circuit breaker through a conductor, and connected to the other end of the cable. The busbar is formed by a solid-insulated busbar. The conductor connecting the vacuum circuit breaker to the busbar and the conductor connecting the vacuum circuit breaker to the grounding device are both formed by a solid-insulated conductor. The circuit breaker chamber and the grounding device have a sealed structure.

A circuit interrupter includes, a first contact and a second contact, the second contact being moveable relative to the first contact, a drive assembly structured to move the second contact relative to the first contact, and an erosion monitoring device including a linear transducer coupled to a portion of the drive assembly. The liner transducer is structured to generate an output signal representative of an amount of linear displacement of the portion of the drive assembly, wherein the erosion monitoring device is structured to monitor a degree of erosion of at least one of the first contact and the second contact based on the output signal.

A gas circuit breaker comprising: a sealed tank; two breaking sections disposed in the sealed tank; a bracket to support movable parts of the breaking sections while enabling switching operation of the movable parts; an insulation cylinder to support the bracket through an electric field relaxation shield; an insulated operating rod disposed in the insulation cylinder movably in the axial direction and an end thereof is connected to an actuator; and a link mechanism connected to other end of the insulated rod and transmits drive force from the actuator to the movable parts of the breaking sections, wherein the electric field relaxation shield is provided with out-side groove and in-side groove on the insulation cylinder respectively, and the out-side groove and in-side groove are formed openings at the link mechanism side respectively, and end of the in-side groove is extended to near the outer surrounding of the insulated operating rod.

A sealed solenoid, magnetically operated electric power switch is suitable for use as capacitor, line and load switch operating at transmission and distribution voltages that includes no dynamically moving seals through the sealed container housing the contactor portion of the switch. The sealed solenoid switch includes a magnetically operated drive system with an actuator that magnetically couples across the container wall to avoid the use of a moving or sliding seal as part of the drive system. The sealed solenoid switch may also include a ballast resistor and resistor contact located inside the sealed container to avoid another seal as part of the ballast system. A magnetic latch holds the switch in a closed position, and a spring holds the switch in the closed position, to avoid the need for an energizing current to maintain the switch in either position.

In a vacuum circuit breaker corresponding to three-phase, which is configured by linearly arranging three pressure tanks respectively corresponding to one-phase, in which insulation gas is encapsulated, and a vacuum valve is installed, each pressure tank has a nearly longitudinal shape or a nearly square shape, viewed from a plane surface, and the vacuum valve is arranged in each of the pressure tanks in a state where a drive direction of the movable conductor is aligned with an upper lower direction, and the movable conductor is positioned lower than the vacuum valve, and keeps a sufficient insulation distance with respect to the movable-side connection conductor, and is neared to a position in one of diagonal directions or longitudinal directions of the pressure tank having a nearly square shape or nearly ellipsoidal shape, and moreover, the operation mechanism is arranged and configured at a position, which is lower than the vacuum valve.

A gas circuit breaker includes movable and fixed electrode parts arranged to face each other in an engaging/separating manner in a container filled with an insulating gas, an operating mechanism attached to a partition of the container and configured to output an operating force to the movable electrode part, an operating rod attached to the movable electrode part, a first link rotatably attached to the operating rod, a lever rotatably attached to the first link, a support bearing fixed to the partition of the container via an insulating spacer, a second link rotatably attached to the lever and also rotatably attached to the support bearing, a seal bearing connected through the partition of the container, a seal rod rotatably attached to the center of the lever and slidably supported to the seal bearing, and a third link rotatably attached to the seal rod and also attached to the operating mechanism.

A switch unit includes a plurality of switches, which are linearly disposed. The movable electrode in one switch and the fixed electrode in another switch are electrically connected to each other.

An arc chamber for a circuit breaker has first and second mounting bodies. The mounting bodies are disposed at the ends of an electrically insulating insulation section of the arc chamber. The insulation section is formed of at least two shell-shaped partial sections. The partial sections are curved concavely relative to a longitudinal axis of the arc chamber. A gap is formed between the edges of the bodies of the partial sections.

Provided is a sector gear including: a drive gear having a drive part that forms a part of a circle and has a plurality of teeth and a non-drive part that forms a remaining part of the circle and provides a non-contact angle of at least approximately 90 degrees; first and second movers forming a disconnector and a grounded breaking switch, respectively; and first and second driven gears engaged with the drive gear and respectively engaged with the first and second movers and configured to make the first mover or the second mover operate in conjunction with the drive part of the drive gear according to a direction of rotation of the drive gear, wherein an intermediate angle between the first and second movers is between approximately 90-135 degrees. The present invention can reduce the size of the gas-insulated switchgear having the sector gear.

An electrode assembly for a circuit breaker is provided. The electrode assembly includes a conductive assembly and a heat transfer assembly. The conductive assembly includes a stem portion and a contact portion. The heat transfer assembly includes a number of elongated bodies, a first heat transfer surface, and a second heat transfer surface. The first heat transfer surface is disposed on the conductive assembly. Each heat transfer assembly body includes a second heat transfer surface. Each heat transfer assembly body is coupled to the conductive assembly with the first heat transfer surface coupled to a number of second heat transfer surfaces.

A gas insulated switchgear includes an enclosure, a first fixed conductor, one side of the first fixed conductor being bent at a right angle and another side of the first fixed conductor being fixed on one side of the enclosure, a second fixed conductor configured to be spaced apart from the first fixed conductor and configured to be fixed on another side of the enclosure, a screw configured to form an axis on inner of the enclosure and being spaced apart from the first and second fixed conductors and a movable conductor configured to move along the axis through a rotation of the screw, one side of the movable conductor being in contact with the second fixed conductor.

A gas circuit breaker is provided, avoiding change in the position of a cover member and without weakening of the blow of gas to the arc in an arc discharge cavity even when a surface of the cover member in contact with the arc discharge cavity is damaged. The gas circuit breaker includes a contact ring, a holder attached to the contact ring, and extending to a path of arc-extinguishing gas that extinguishes an arc, and an electrically insulative cover member attached to the holder.

A flexible shunt for a vacuum circuit breaker can have a reduced straight length and improved flexibility even with an increased thickness within a predetermined accommodation space of a main circuit part. The flexible shunt comprises a pair of conductive plates, each including a clamp connecting portion configured as a flat conductive member, the clamp connecting portion being connected the clamp, a terminal side connecting portion configured as a flat conductive member, the terminal side connecting portion being connected to the terminal side, and a flexible curved portion configured to connect the clamp connecting portion to the terminal side connecting portion, the flexible curved portion being formed to be projected outwardly.

A gas-insulated type circuit breaker including a housing defining a gas volume for a dielectric insulation gas; a first arcing contact member and a second arcing contact member, wherein the first arcing contact member and the second arcing contact member are movable relative to each other along an axis; a first nominal contact member and a second nominal contact member, wherein the first nominal contact member and the second nominal contact member are movable relative to each other along the axis; and a first nominal contact shielding arrangement including an inner shield member and an outer shield member, wherein the inner shield member and the outer shield member are arranged coaxially about the axis. The first nominal contact member is arranged co-axially between the inner shield member and the outer shield member, and is movable relative to the inner shield member and to the outer shield member.

The disclosure relates to a gas circuit breaker switch (5) which can be integrated inside a switching device insulated in a dielectric gas, said switch (5) comprising an arc chute (1) inside which a fixed contact (3) and a moving contact (4) are arranged. The integration of the contacts (3, 4) inside at least one casing (19, 20) corresponding to the arc chute (1) allows reducing distances between phases, in addition to preventing any incident in one phase from affecting the remaining phases, and finally more compact electrical equipment is obtained. The switch (5) also comprises at least one generation means (6) for generating at least one gas, at least one blowout/intake means (7) for at least one extinguishing gas and at least one generation means (2) for generating a magnetic field, such that the electric arc generated between the contacts (3, 4) of the switch (5) can be extinguished by combining said means (6, 7, 2).

A circuit breaker includes a first contact and a second contact. An electric arc zone is disposed between the contacts. A feed channel opens into the electric arc zone, connecting the electric arc zone to a hot gas reservoir volume. The hot gas reservoir volume, in turn, is connected to a compression volume. An outflow opening is disposed in a wall of the compression volume. The outflow opening is permanently open, at least in a contacting state of the contacts.

Circuit breakers include an arc chamber and an arc chute comprising a plurality of arc plates in the arc chamber. The circuit breakers also include a line conductor assembly with at least one arc runner attached to a line conductor in the arc chamber. The arc runner can extend below but adjacent to a bottom arc plate to thereby guide a respective arc into the arc chute.

An arc guider configured to provide an arc movement path, one side thereof forming a fixation projection and a center thereof forming a groove in a longitudinal direction, a fixation element sequentially including a main contact, an arc contact being spaced apart from the main contact and an insertion groove accommodating the arc guider and a plurality of projection fixing units being formed on both sides of the insertion groove and being curved toward the accommodated arc guider through an outer force so that the fixation projection does not escape wherein triangle V shaped groove marks by the outer force are formed in the plurality of the projection fixing units.

Containers and dispensers for wiping substrates, and wet wiping substrates in particular, have been provided with lids, the containers have been susceptible to leakage, or difficulties in dispensing the contents. Provided is a refillable container for storing and dispensing wiping substrates. A refill cartridge containing wiping substrates having a peelable seal disposed on a first surface and a second surface for forming a seal with the container lid is provided.

A sheath for a knife is ventilated or is formed with gaps in a way that sand and other debris cannot collect to dull the knife's blade. The sheath holds the knife, protects and safely covers the sharp edge, but does not provide a surface for abrasive sand to dull the edge. The sheath can include front and rear panels, held together with a plurality of spacers disposed between the panels. The spacers can be rounded to as to minimize contact between the spacers and the blade of the knife.

A toilet tissue roll holder is provided having a telescoping structure that is attachable to a wall surface for providing replacement toilet tissue to a dispenser and shrouding unused rolls prior to deployment. The device includes a lowermost housing having a base surface, rounded sidewalls, an interior volume, and an open front. The lowermost housing connects to a first upstanding sidewall thereabove, which in turn supports a plurality of telescoping sidewalls that form individual toilet tissue roll containers extending upward. A viewing window is provided through at least one of the device sidewalls above the lowermost housing to allow an administrator to visualize whether a minimum number of reserve toilet paper rolls are still available. The structure is expanded and contracted depending on the number of rolls therein, while the lowermost housing and first upstanding sidewall provide the base structure that is secured to a support wall.

A method of treating a cancer of the central nervous system in a subject in need thereof is provided. The method comprising administering to the subject a therapeutically effective amount of an agent which reduces blood glutamate levels and enhances brain to blood glutamate efflux to thereby treat the cancer of the central nervous system in the subject.

A reversible folio for a tablet computer has a tablet shell with a cavity removably receiving the tablet computer. A keyboard is pivotally and removably coupled to the tablet shell. A channel is pivotally coupled to an edge of the keyboard. An interior of the channel removably receives the proximal edge of the tablet shell, and has a profile mating with a profile of the tablet shell. The channel and proximal edge have first and second symmetrical magnet arrays, respectively. The proximal edge of the tablet shell physically mates with the channel of the keyboard, and the second magnet array of the tablet shell magnetically mates with the first magnet array of the channel, in both a first orientation and an opposite second orientation.

A container has a base and walls connected to the base to define an interior space. The walls have upper edges that terminate in a plane and define an opening for access to the interior space. Wetted donnable articles are stacked within the container, each article in a flat configuration at least partially perpendicular to the opening permitting withdrawal of any one of the donnable articles through the opening in a flat configuration. Walls on opposing sides of the base of the container diverge from each other with increasing distance from the base, such that the interior space widens gradually toward the opening. Walls on other opposing sides of the base have lower portions connected to the base and upper portions connected to the lower portions by steps that lengthen the interior space abruptly.

A container storing an anesthetic is disclosed. The container is sealed by a closure and stores a liquid anesthetic solution. The anesthetic is from 0.1% to 10% by weight of the liquid anesthetic solution. The container is made of a material that is inert to the anesthetic and the closure is made of siliconized rubber or a metal. A concentration of the anesthetic in a liquid anesthetic solution stored in the container following a predetermined time period is at least 93% of a concentration of the anesthetic in a liquid anesthetic solution before the liquid anesthetic solution is stored in the container.

A communications device may include a near-field communication (NFC) circuit device, and a radio frequency (RF) signal blocking member adhesively coupled with the NFC device. The RF signal blocking member may be configured to block RF signal communication by the NFC device while coupled therewith. The RF signal blocking member may comprise an electrical conductor. In accordance with an example, the RF signal blocking member may comprise a frangible layer. In another example, a pressure sensitive adhesive layer may be included for adhesively securing the RF signal blocking member with the NFC device.

A binder management system having a cabinet with shelves for removable storage of searchable binders. Each binder has a body with front and rear covers and a spine. Inside the body is a binder mechanism for removably retaining sheet media. Each binder has externally extending upper and tower ohmic contact members which ohmically engage conductive members mounted on the shelf surfaces near the front. Each binder has a binder identification circuit coupled to an LED mounted on the binder spine in a location visible when the binder rests on a shelf. When a binder identification signal from a host computer is presented to the shelf conductive members it is transferred by the binder contact members to the binder identification circuit. If the signal matches, the LED is activated to aid the user in finding the binder. An LED and an optional audible indicator are mounted on the shelves to further aid the user in finding the sought binder.

Disclosed is a plastic film with concealed tearable strip, which includes a film body; at least one first tearable strip having two sides respectively forming first and second joint sections; and at least one second tearable strip having two sides respectively forming a third joint section and an internal tear line. The first and second tearable strips each have one side connected to the film body. The first joint section has two sides each forming a tear line. The third joint section has one side forming at least one tear line. The third joint section and the internal tear line have inside faces respectively coupled to the first and second joint sections, whereby the first and second tearable strips are respectively located at outside and inside of the film body and the second tearable strip is concealed at the inside of the film body.

An improved learning aid in the form of a book, the book includes a front cover, a back cover, and a plurality of pages intermediate the front cover and the back cover. The plurality of pages, front cover, and back cover are conventionally bound together along one longitudinal side by a binding means. The back cover includes an outer side disposed with a plurality of sections. Each of the sections printed text framed by a text identification and sequence indicator, wherein the printed text is a complete reproduction of the text printed on a particular numbered page of the plurality of pages of the book.

A method for producing a continuous web of printed material for use in creating mailpieces. The continuous web has a width and a length, the length comprised of a series of attached sheets. The series of attached sheets are comprising envelope sheets and rectangular content pages. The content pages are rectangular in shape and may be oriented relative to the envelope sheets in a number of different configurations. In some configurations, two sets of content pages and/or envelope sheets can be printed across the width of the web. Sheets for forming business return envelopes may be printed in series with the content pages and envelope sheets. BREs may include individualized return addresses. A control code may be printed on one or more of the sheets for a given mailpiece, providing information for controlling assembly of the mailpiece. Two sets of sheets may be printed across the width of the web by printing content pages onto the continuous web such that two end-to-end content pages are printed across the width of the web. Positioning of mail content pages and envelope sheets for a given mailpiece may be optimized based on respective processing times determined for the system.

Method for binding a bundle of loose leaves or the like in a cover. The method includes the step of providing an end leaf that includes a fixing strip on a side edge, with the fixing strip partly fixed to the end leaf and provided with a strip of glue on a part of the fixing strip which is not fixed to the end leaf. On the side of the fixing strip turned away from the end leaf, said strip of glue being provided with a removable foil. Another step is binding a free edge of the bundle of loose leaves together with the end leaf. Further steps include removing the foil, and providing the bound edge of the bundle of leaves and the end leaf in the back of the cover and fixing thereof in the cover only by the strip of glue.

An inside leaflet of a book is provided which is bond-bound with pages of the book to provide an advertisement. The inside leaflet includes an advertisement printed part and a binding part. Catchphrases or illustrations for advertisement are printed on at least one side of the advertisement printed part. The binding part is configured to be bound with the pages along an edge of the inside leaflet such that the binding part has less binding portions than those of the pages in order to leave no traces or marks when the inside leaflet is detached from the book. Accordingly, since the inside leaflet is able to be bound to pages of various kinds of books and easily removed from the books without leaving any traces or marks in the books, the inside leaflet contributes to extension of the application range of advertisements and improvement of advertisement efficiency.

A radio-frequency (RF) amplifier having a direct response to an arbitrary signal source to output one or more electrosurgical waveforms within an energy activation request, is disclosed. The RF amplifier includes a phase compensator coupled to an RF arbitrary source, the phase compensator configured to generate a reference signal as a function of an arbitrary RF signal from the RF arbitrary source and a phase control signal; at least one error correction amplifier coupled to the phase compensator, the at least one error correction amplifier configured to output a control signal at least as a function of the reference signal; and at least one power component coupled to the at least one error correction amplifier and to a high voltage power source configured to supply high voltage direct current thereto, the at least one power component configured to operate in response to the control signal to generate at least one component of the at least one electrosurgical waveform.

Circuits and techniques to linearize the operation of an RF power amplifier are described. A linearizer circuit may include a non-amplification signal path which includes a delay line and an amplification signal path which includes at least one amplifier stage. In some embodiments, the amplification signal path may include an odd number of amplification stages. The linearizer may be used to precondition an input signal of an RF power amplifier in a manner that improves the overall linearity of operation.

A differential circuit with a function to compensate unevenness observed in the differential gain thereof is disclosed. The differential circuit provides a low-pass filter in one of the paired transistors not receiving the input signal in addition to another low-pass filter that provides an average of output signals as a reference level of the differential circuit. The cut-off frequency of the filter is preferably set to be equal to the transition frequency at which the self-heating effect explicitly influences the trans-conductance of the transistor.

An amplifier circuit includes an input terminal and an output terminal. A current sinking transistor includes a first conduction terminal coupled to the output terminal and a second conduction terminal coupled to a reference supply node. A voltage sensing circuit has a first input coupled to the input terminal and a second input coupled to the output terminal. An output of the voltage sensing circuit is coupled to the control terminal of the current sinking transistor. The voltage sensing circuit functions to sense a rise in the voltage at the output terminal which exceeds the voltage at the input terminal, and respond thereto by activating the current sinking transistor.

Split amplifiers with configurable gain and linearization circuitry are disclosed. In an exemplary design, an apparatus includes first and second amplifier circuits and a linearization circuit, which may be part of an amplifier. The first and second amplifier circuits are coupled in parallel and to an amplifier input. The linearization circuit is also coupled to the amplifier input. The first and second amplifier circuits are enabled in a high-gain mode. One of the first and second amplifier circuits is enabled in a low-gain mode. The linearization circuit is enabled in the second mode and disabled in the first mode. The amplifier is split into multiple sections. Each section includes an amplifier circuit and is a fraction of the amplifier. High linearly may be obtained using one amplifier circuit and the linearization circuit in the low-gain mode.

Apparatus and methods disclosed herein perform gain, clipping, and phase compensation in the presence of I/Q mismatch in quadrature RF receivers. Gain and phase mismatch are exacerbated by differences in clipping between I & Q signals in low resolution ADCs. Signals in the stronger channel arm are clipped differentially more than weaker signals in the other channel arm. Embodiments herein perform clipping operations during iterations of gain mismatch calculations in order to balance clipping between the I and Q channel arms. Gain compensation coefficients are iteratively converged, clipping levels are established, and data flowing through the network is gain and clipping compensated. A compensation phase angle and phase compensation coefficients are then determined from gain and clipping compensated sample data. The resulting phase compensation coefficients are applied to the gain and clipping corrected receiver data to yield a gain, clipping, and phase compensated data stream.

A scan head assembled to a scan arm for an ion implanter and a scan arm using the same are provided, wherein the scan head is capable of micro tilting a work piece and comprises a case, a shaft assembly, an electrostatic chuck, a first driving mechanism and a micro-tilt mechanism. The shaft assembly passes through a first side of the case and has a twist axis. The electrostatic chuck is fastened on a first end of the shaft assembly outside the case for holding the work piece. The first driving mechanism is disposed within the case and capable of driving the shaft assembly and the ESC to rotate about the twist axis. The micro-tilt mechanism is disposed within the case and capable of driving the shaft assembly and the ESC to tilt relative to the case.

A damping tool holder, such as a boring head, a chuck, or a milling cutting arbor, integrates a damping device (2), in the form of an elongated body. The damping device (2) is housed in a mounting body (3), connected by one end to the tool-holder body (1) and having at its other end an end fitting (4) for mounting a tool, whereby the mounting body (3) is equipped with at least one lubricant feed pipe (32), emptying at its front end into the end fitting (4) for mounting a tool and connected at its other end to a circular groove (102) for distributing lubricant that is provided on the front surface of the tool holder (1).

Embodiments of the present invention generally provide chamber components with enhanced thermal properties and methods of enhancing thermal properties of chamber components including bonding materials. One embodiment of the present invention provides a method for fabricating a composite structure. The method includes applying a bonding material to a first component, and converting the bonding material applied to the first component to an enhanced bonding layer by heating the bonding material to outgas volatile species from the bonding material. The outgassed volatile species accumulates to at least 0.05% in mass of the bonding material. The method further includes contacting a second component and the enhanced bonding layer to join the first and second components.

The test fixture includes a housing, a first grip, and a second grip. The first grip and the second grip are each configured to clamp onto an upper surface and lower surface of a material coupon. The test fixture also includes an upper input jaw and a lower input jaw each configured to clamp onto the material coupon near a center of the upper surface and the lower surface of the material coupon. The test fixture is configured to load the material coupon in a first direction and a second direction. The first grip and the second grip are each configured to clamp onto the material coupon at a location which accordingly results in a desired testing ratio regardless of a variation in thickness of the material coupon.

The present invention discloses a kind of universal mounting hole means for different tool heads of electric tools, which are disposed on a mounting portion of the tool head, comprising a central hole and a plurality of long and narrow limiting holes which orient radially surrounding the central hole and disposed in distance with each other. Compared with the prior art, the present invention is applicable to various kinds of structures of the mounting seat on electrical tool and is more universal. It takes much convenience to people when changing different tool heads of electric tools, and it is benefit for storing.

A pin-and-collet assembly, a longwall shearer comprising a ranging arm attached to a lifting bracket with such assembly, a method for the secure fastening of one piece to another, such as securely fastening the ranging arm to the lifting bracket of a longwall shearer using such assembly as a bushing, and a method for longwall mining of ore, such as trona, using such longwall shearer. This assembly is easy to install, does not have to be tightened during longwall operation of an ore panel, and is also demountable when it is time to stop the longwall mining operation and time to remove/replace the ranging arm for maintenance and/or when the end of the ore panel is reached.