2711 results about "Bearing surface" patented technology

Disclosed is a cylindrical battery, comprising a housing, bare cells, a first current collector, a second current collector, and a cover plate, wherein the housing comprises a columnar main body, with a first opening being provided in one end of the columnar main body and a second opening being provided in the other end of the columnar main body; a first full-tab is provided at one end of each of the bare cells and a second full-tab is provided at the other end of the bare cell, the first full-tab being connected to the cover plate by means of the first current collector; the other end of the columnar main body extends into the second opening to form a connecting portion, the connecting portion bends toward the first opening to form an annular connecting surface, and the annular connecting surface bends toward an axis of the columnar main body to form a bearing surface; and the second current collector comprises an outer edge which is in lap joint with the bearing surface and which is connected to the bearing surface by means of laser welding, and a protrusion protruding toward the first opening, the protrusion being connected to the second full-tab by means of laser welding. The present application uses laser penetration welding, which provides firm welding and effectively meets the requirements of high charging and discharging rates of cylindrical power batteries.

The invention discloses an assembly demagnetizing bearing device, and relates to the technical field of automation equipment. The carrier is fixedly arranged on the mounting seat and is provided with a bearing surface; a channel extending in the first direction is arranged in the carrier. A magnetic attraction piece is arranged in the channel; in the first direction, the size of the magnetic attraction piece is smaller than that of the channel; the magnetic attraction piece can move in the channel so as to be switched between a material attraction position close to the bearing surface and a material discharging position far away from the bearing surface; the carrier is provided with a waiting position where the bearing surface is horizontally arranged and a working position where the bearing surface is vertically arranged; the two first stop blocks are slidably connected to the mounting base in the second direction, and the two first stop blocks are located on the two sides of the carrier in the second direction respectively; the second direction is parallel to the bearing surface; the second stop block is slidably connected to the mounting seat and faces the bearing surface; and the first driving piece is connected with the mounting seat. According to the assembly demagnetizing bearing device, other workpieces can be conveniently assembled on the side face of the workpiece.

An adjustable chock is provided with a first component having screw threads, a second component having screw threads cooperating with the screw threads of the first component and having a lower bearing surface, and with a bearing element provided with a lower bearing surface in contact with an upper bearing surface of the first component, and with an upper bearing surface. At least one of the lower bearing surface of the second component and the upper bearing surface of the bearing element is provided with a coating having a coefficient friction higher than that of the associated bearing surface.

A kit includes an adjustable chock provided with a first component having screw threads and with a second component having screw threads cooperating with the screw threads of the first component and having a lower bearing surface, and with a bearing element provided with a lower bearing surface in contact with an upper bearing surface of the first component, and with an upper bearing surface. The kit further includes at least one friction ring adapted to be mounted against the lower bearing surface of the second component or against the upper bearing surface of the bearing element.

The invention discloses a bidirectional active follow-up loading device and a control method thereof.According to the device, through the synergistic effect of a loading mechanism, a spherical hinge and a lower-layer follow-up mechanism, rapid and accurate compensation can be achieved according to the deviation angle, active detection and compensation of inclination angles in two directions are achieved, and the loading efficiency is improved. The loading force is always kept consistent with the normal direction of the loading force bearing surface; according to the method, the compensation displacement of the mobile platform is calculated through the inclination angle of the cross bearing, and the double-layer follow-up mechanism is driven to compensate the offset distance between the X axis and the Y axis, so that the loading direction is always kept consistent with the normal direction of the loading force bearing surface, and dynamic compensation in multiple directions is realized, thereby ensuring that the direction of the loading force is always kept accurate; the compensation amount is fed back and adjusted in real time, the influence of nonlinear change of the effective length of the loading hydraulic cylinder on the loading force is reduced, the compensation process in the control method is smooth, and the response speed and the compensation precision are improved.

A hinge assembly for a door-in-door assembly includes a door plate, a cabinet plate, and a thimble. The thimble has a wall having an inner bearing surface and an outer bearing surface, the inner bearing surface defining a first passage. The door plate is supported for rotation at the outer bearing surface. The cabinet plate includes a pivot pin that is supported for rotation at the inner bearing surface.

The invention discloses a meter-scale leveling and aligning static pressure rotary table shaft system structure expanding torque in the radial direction and a method. The meter-scale leveling and aligning static pressure rotary table shaft system structure comprises a base, a lower plate, an upper plate, a leveling structure, an aligning structure and a workbench. A lower plate is arranged on the base, an upper plate is arranged on the lower plate, the upper plate is fixedly connected with a rotor, and the rotor is directly connected with a motor rotor; the top end of the upper plate is vacant, and the bottom end of the upper plate is provided with an adsorption structure and a supporting surface and matched with the top end of the lower plate; the leveling structure and the aligning structure are both mounted on the lower plate and are arranged on the same horizontal plane; according to the rotary table shaft system structure, a torque transmission path expanding in the radial direction is adopted, the extending amount of an aligning ball head is controlled through an aligning structure, a lower plate is promoted to move in the opposite direction of the extending direction of the aligning ball head relative to an upper plate, and axial aligning of a workbench and a rotor is achieved; and the leveling structure is used for positioning the plane of the workbench through three points, so that the workpiece is leveled. According to the invention, the leveling and aligning functions of large-size high-precision rotary tables with meter-scale calibers and above can be realized, and the table-board distance of the rotary table is reduced.

The invention discloses locking assembly equipment and an intelligent glasses assembly line body, and relates to the technical field of intelligent wearable device.The locking assembly equipment comprises a machine table, a conveying device, a turnover device, a locking device and a carrying device.The conveying device comprises a movable base, and the turnover device comprises a turnover platform rotationally installed on the movable base; in the rotating process of the overturning platform, the overturning platform has a material bearing state enabling the bearing face to be arranged upwards and a locking matching state enabling the bearing face to be arranged towards the side, and when the movable base is located at the locking station and the overturning platform is in the locking matching state, the locking electric screwdriver assembles the glasses frame and the glasses legs through screws. And the carrying device is used for transferring the circulation tool with the to-be-assembled intelligent glasses to the overturning platform in the material bearing state, and moving away the circulation tool which is transferred to the discharging station and is in the material bearing state on the overturning platform. The intelligent glasses are locked after being turned to a proper angle, so that the use of a complicated locking mechanism can be avoided, and the locking efficiency is improved.

The invention discloses an automatic copper pipe tooth rolling production line, and belongs to the technical field of copper pipe tooth rolling machining. The gear rolling production line comprises a plurality of gear rolling machines, a feeding line and a feeding assembly. The feeding assembly comprises a feeding conveying mechanism, a jacking distributing mechanism, a feeding buffering mechanism and a longitudinal conveying mechanism. The feeding conveying mechanism comprises a feeding frame and a plurality of feeding conveying units, the feeding temporary storage mechanism comprises a feeding temporary storage frame, and a temporary storage part of the feeding temporary storage frame and a bearing surface of a discharging guide part are obliquely arranged; the jacking and distributing mechanism comprises a jacking and distributing unit, and the jacking and distributing unit comprises a first-stage jacking frame and a second-stage jacking frame. The position layout of the tooth rolling machines is reasonable, the space of a plant workshop is fully utilized, the feeding requirements of multiple tooth rolling machines can be met by arranging the feeding assembly on one layer and one feeding line in the workshop, the production rhythm of the multiple tooth rolling machines can be met, copper pipes are stable, reliable and high in conveying efficiency in the conveying process, the falling risk is avoided, and the production efficiency is improved. And the safety of equipment and personnel is ensured.

The invention relates to a recirculator (30) for a nut (12) of a ball screw mechanism (1), comprising an annular body (32) having a reference axis (300) intended to be aligned with a helical axis of the nut (12), the annular body (32) comprising a bearing surface (36), and a guide structure (34) arranged on the bearing surface (36), the bearing surface is configured to bear a nut (12) against the ball screw mechanism (1) in a bearing direction having an axial component parallel to the reference axis (300), the guide structure is configured to guide the balls in the circulation path opening at a first guide end (62) into a recirculation channel of the nut (12) and at a second guide end (72) onto a raceway (116) defined by a thread of the nut (12), characterized in that the bearing surface (36) lies at least partially in a cross-sectional plane (130) intersecting the recirculation path and perpendicular to the reference axis (300).

The invention provides a high-stability low-noise uniform mixing oscillator. The high-stability low-noise uniform mixing oscillator comprises an oscillation platform and a base unit, the bottom surface of the oscillation platform is provided with three ball bearing surfaces which are distributed along the circumference in an array manner and at least three magnetic columns which vertically extend downwards, and the magnetic columns are sleeved with rolling bearings; a lower base body of the base unit is provided with three concave ball containing holes and at least three concave polarization track groove holes, balls are arranged in the ball containing holes, first elastic rings are arranged in the middles of the inner walls of the ball containing holes, and second elastic rings are arranged on the inner walls of the polarization track groove holes. The oscillation platform is supported through three balls with the same height, the three points form a stable supporting face, under the non-contact magnetic attraction effect, the oscillation platform can still be kept on the same plane during high-frequency oscillation, and the operation stability is improved; during oscillation, the column body of the magnetic column is firstly buffered by the contact between the elastic ring and the rolling bearing, and then the column body of the magnetic column is contacted with the inner wall of the polarization track groove hole, so that the noise during high-frequency oscillation can be obviously reduced.

The invention discloses a polystyrene plastic plate compression resistance testing device and method for refrigerator liner production, and relates to the technical field of refrigerator liner production. The device comprises a testing machine and a plastic plate, and further comprises a positioning unit which comprises a positioning assembly and a moving assembly; the pressure control hydraulic cylinder is arranged on the testing machine; the pressure applying testing unit comprises an adjusting assembly and a testing assembly, the adjusting assembly is used for adjusting the size of the pressed face of the plastic plate to achieve multi-area pressure applying, and the testing assembly is used for detecting and judging the testing result. The device has the advantages that the size of the compression surface of the plastic plate can be flexibly changed when the compression resistance of the polystyrene plastic plate is detected, the compression resistance of the plastic plate under different compression surfaces can be tested, the stress position of the plastic plate can be flexibly changed, the plastic plate cannot be damaged during testing, multi-position testing can be realized on the same plastic plate, and the testing efficiency is improved. The number of test samples is larger, and the test result is more accurate.

The invention discloses a concrete quality detection device, and relates to the technical field of concrete detection, the concrete quality detection device comprises a detection table and a fixing cylinder, the fixing cylinder is installed at the center position of the detection table in a penetrating manner, a supporting seat is installed at the position, located on the rear side of the fixing cylinder, of the detection table, and a hydraulic cylinder is installed at the top of the supporting seat; the movable end of the hydraulic cylinder is connected with a pressing plate, and an auxiliary mechanism is arranged in the fixed cylinder and used for transferring a concrete block sample and cleaning the crushed concrete block sample. And the orientation of the concrete block sample is adjusted, so that the polished flat surface is in contact with the pressing surface of the pressing plate and the bearing surface of the bearing plate, uniform pressure application to the concrete block sample during compression resistance detection is ensured, and the situation that detection data are wrong due to the fact that pressure intensively acts on convex points of the concrete block sample is avoided.

Examples include a pile cutting apparatus including a cutting device for cutting a sheet pile, with a front pile bearing surface, a rear pile bearing surface, and a cutting gap arranged therebetween. A table plane contains the front pile bearing surface. The cutting device further includes a movable upper blade, a lower blade including a cutting edge, and a cutting aid for fixing sheet piles that is upstream from the upper blade along a transport path for transporting sheet piles. A movable support element has a contact surface for supporting sheets and is movable between a support position and a disposal position. The contact surface, when the support element is arranged in the support position, is arranged in and / or beneath the table plane, and is closer to the cutting edge when the support element is in the support position than when the support element is in the disposal position.

The invention provides a rigidity-adjustable bearing platform, which can realize multi-gear adjustability of bearing rigidity, can adjust the inherent frequency of the whole load after being connected with the load, and belongs to the related technical fields of mechanical engineering, aerospace, constructional engineering and the like. According to the platform, a plurality of parallel flexible supporting paths are arranged between a mounting surface and a bearing surface, and different supporting rigidities of the platform are achieved by locking and releasing the flexible supporting paths. The principle is simple and reliable, the structural form is flexible and changeable, and the supporting rigidity is not affected by environmental factors.

A hinge assembly for a door-in-door assembly includes a door plate, a cabinet plate, and a thimble. The thimble has a wall having an inner bearing surface and an outer bearing surface, the inner bearing surface defining a first passage. The door plate is supported for rotation at the outer bearing surface. The cabinet plate includes a pivot pin that is supported for rotation at the inner bearing surface.

The embodiment of the utility model discloses a driving wheel device and cleaning equipment, and the driving wheel device comprises a driving wheel assembly which comprises a first supporting part which is provided with a first connecting part and a second connecting part which are located in different areas; the first connecting part is used for being rotatably connected with a machine body of the cleaning equipment; the driving wheel is rotatably arranged on the first supporting piece and is used for being in contact with a bearing surface; the traction piece is used for being movably arranged on a machine body of the cleaning equipment; the traction piece is connected with the second connecting part, and the traction piece is used for enabling the first supporting piece to rotate relative to the machine body so as to adjust the height of the portion, protruding out of the machine body, of the driving wheel; wherein the traction piece is of a non-elastic structure.

A clutch for lifting a concrete component, including a toroidal connector, a latch movable relative to the toroidal connector between a disengaged condition and an engaged condition, and a coupler for coupling the toroidal connector to a lifting apparatus, wherein the toroidal connector has a circular seat for sitting upon a circular upper surface of a head of and anchor coupled to the toroidal connector, wherein the circular seat terminates in a radial bearing surface for abutment with a castellation of the anchor.

The invention discloses a transverse conveying device for pipe fittings, and belongs to the technical field of pipe fitting conveying. The pipe fitting conveying device comprises a pipe fitting conveying mechanism, and the pipe fitting conveying mechanism comprises a conveying frame, a plurality of conveying rollers, a conveying roller driving mechanism, a transverse conveying mechanism arranged on one side or two sides of the conveying frame and a lifting mechanism used for jacking up pipe fittings on the conveying rollers. The transverse conveying mechanism comprises a conveying arm shaft, a plurality of transverse conveying arms and a rotation driving mechanism, a guide mechanism used for guiding the pipe fittings to the transverse conveying arms is further arranged on the conveying frame, the guide mechanism comprises a plurality of guide plates, the guide plates are arranged in the length direction of the conveying frame, and the bearing surfaces of the guide plates are obliquely arranged in a mode that the inner portions are high and the outer portions are low. The overall layout is compact, the workshop height does not need to be adjusted, the workshop construction cost is reduced, the pipe conveying process is stable, and the safety of equipment and personnel is ensured; the pipe fitting conveying process is easy to operate, and the labor cost and the possibility of misoperation are reduced.

A constant velocity joint comprises a male element having arms, a female element having a central axis and defining a pair of symmetrical tracks and an outer roller which can roll on one or other of the two tracks via a peripheral rolling surface. The female element comprises at least one bearing surface which limits the rotation of the outer roller around an axis perpendicular to the axis' of the female element and of the arm. With respect to each arm the cross-section profile of each track comprises either two circular arcs having centers of radii offset one from another, or one single circular arc extending over a female element median plane, and the rolling surface has a part spherical shape or a part torical shape. Each track and the rolling surface are capable of contacting each other at a first and second contact points spaced radially from one another. The tilting of the roller is controlled by proximal and distal rails on the female element and by proximal and distal breaking surfaces on the outer roller.

A separating device for profiles (6) comprises transfer means (8) between supporting surfaces (13) of successive transverse conveyors (1, 2, 3) that have receptacles (11) for a plurality of profiles (6). The receptacles are displaceable in rotary steps of a shaft (9) between a pick-up position and a handover position and form a driver surface (12) that, in the pick-up position, engages under only one profile (6). Stop cams (14) for the profiles (6) are associated with the receptacles (11), and stop points (16) determining the contour (15) of the stop cams (14) define an angle of rotation (a) of the stop cams (14) and a distance (h) from the bearing surface (13) of the transverse conveyor (1, 2, 3). The rear boundary edge (18) of the bearing surface (17), which is determined by the stop points (16) as a function of the cross-sectional shape and size of the profiles (6), is at least at the same distance from the shaft (9) as the outer end (19) of the driver surface (12). The transverse conveyors (1, 2, 3) can be controlled as a function of the stop of the profiles (6) at a stop cam (14) rotated into the rotational position for the cross-sectional shape and size of the profiles (6) to be separated.

The utility model discloses a cleaning machine with a rotating assembly, and belongs to the technical field of cleaning appliances, the cleaning machine comprises a floor brush shell, a cleaning part and the rotating assembly, and the cleaning part and the rotating assembly are arranged on the floor brush shell; the rotating assembly rotates relative to the floor brush shell so that the scraping piece can be provided with a dirt scraping position abutting against the cleaning piece and a separation position separated from the cleaning piece, the rotating assembly further comprises a rotating part with a first arc-shaped face, the floor brush shell is further provided with a liquid separation piece, the liquid separation piece is provided with a second arc-shaped face, and the first arc-shaped face is in relative sliding fit with the second arc-shaped face. The arrangement of the first arc-shaped surface and the second arc-shaped surface provides a larger stress surface for the rotation of the rotating assembly, and the acting force borne by the rotating assembly during rotation is uniformly distributed to the contact surface of the first arc-shaped surface and the second arc-shaped surface, so that the possibility of stress concentration in the rotating process of the rotating assembly is reduced; and guarantee is provided for the structural strength of the rotating assembly.

The invention relates to the technical field of semiconductor measurement, in particular to a bearing device which comprises a chuck provided with a vacuum adsorption part, and the vacuum adsorption part is provided with a bearing surface; the vacuum adsorption part comprises a central part and an edge part surrounding the central part, and the edge part comprises at least one annular part; a first air passage and at least one second air passage are arranged in the vacuum adsorption part, the first air passage penetrates through the central part, the second air passage extends from the central part to the edge part, and the second air passage is provided with an air inlet hole located in one side of the bearing surface and an air outlet hole far away from one side of the bearing surface; an air inlet hole of the second air channel is located in the annular part, and an included angle exists between a connecting line of a starting point of the second air channel and the center of the vacuum adsorption part and a connecting line of an end point of the second air channel and the center of the vacuum adsorption part. According to the invention, the adsorption stability of warped wafers in different shapes can be improved at least.

A door hinge for a vehicle door (4), comprising a door-side leaf (11) and a body-side leaf (10), which are pivotably connected to each other about a hinge axis (Z) via a joint (G) having a hinge pin (12), wherein each of the leaves (10, 11) has a hinge block (14, 16) with a hinge eye (15, 17) for receiving the hinge pin (12) and a mounting plate section (13, 18), is characterized in that the door-side leaf (11) is provided with a clamping jaw area (18) facing the vehicle door (4) with at least one clamping jaw having a bearing surface (19, 19', 19") designed to abut the vehicle door (4) and has a through-opening (18') for receiving a clamping bolt (32) and that a pressure plate (31) opposite the clamping jaw area (18) is provided. which can be connected to the clamping bolt (32) at a connection point (35), wherein the clamping bolt (32) is designed,to clamp the pressure plate (31) against the clamping jaw area (18) in a tensioned state.

The invention provides a wafer pre-alignment device, semiconductor equipment and a pre-alignment method. The wafer pre-alignment device comprises a main body frame, a rotating mechanism, a centering mechanism and an alignment assembly. The rotating mechanism is installed on the main body frame and comprises a rotatable suction cup, the rotating axis is in the Z direction, and the upper surface of the suction cup is configured to be a bearing face capable of achieving negative pressure adsorption. The centering mechanism is installed on the main body frame and is configured to drive the position of the wafer placed on the suction cup to be adjusted so that the center of the wafer can coincide with the center of the bearing face. The alignment assembly comprises a reflection part and an alignment sensor, the reflection part is arranged below the bearing surface, the alignment sensor is erected above the bearing surface, and the alignment sensor directly faces the reflection part. After the center of the wafer coincides with the center of the bearing surface and the wafer rotates to a preset angle, the light beam path of the alignment sensor passes through the vacant area at the edge of the wafer. According to the invention, the pre-alignment process of the wafer is realized through a non-visual method, the pre-alignment efficiency is improved, and the pre-alignment precision can be effectively ensured.

The utility model discloses an electric appliance assembly, the electric appliance assembly comprises a smoke exhaust ventilator and a dismounting mechanism, the smoke exhaust ventilator comprises a box body, the box body is used for being arranged on a bearing plate in a penetrating manner, and the bearing plate is provided with a mounting hole; the dismounting mechanism comprises a clamping seat and a clamping piece, the clamping seat is installed on the box body, the clamping piece is movably arranged on the clamping seat, and the clamping piece is used for abutting against the hole wall of the installation hole in the process that the box body penetrates into the installation hole so as to move relative to the clamping seat, penetrate through the installation hole and abut against the bearing face of the bearing plate after penetrating through the installation hole. Therefore, when the range hood is pushed and mounted on the bearing plate from bottom to top, the clamping piece moves under the action of the mounting hole, so that the range hood can be arranged in the mounting hole in a penetrating manner, and the clamping piece can abut against the bearing surface of the bearing plate after penetrating through the mounting hole, so that the range hood does not need to be mounted by using screws in the mounting process, the mounting process is convenient, and the mounting efficiency is improved. The dismounting efficiency is high.

The utility model discloses a rotor module and a logistics conveying line. The mover module comprises a main body piece, an air pump and an electromagnetic valve, the main body piece comprises a bearing face used for making contact with a workpiece, and an adsorption hole is defined in the bearing face; a first air outlet and a first air inlet are defined in the air pump; a first gas path communicated with the adsorption hole, a first gas outlet pipeline communicated with the first gas outlet and a first gas inlet pipeline communicated with the first gas inlet are defined by the electromagnetic valve; and the electromagnetic valve is configured as follows: one of the first air outlet pipeline and the first air inlet pipeline is communicated with the first air path, so that the adsorption hole sucks air or discharges air. According to the rotor module, the air pump can be controlled through the electromagnetic valve to achieve the inflation and air suction functions, the time needed for workpiece loosening is greatly shortened, and the conveying efficiency is improved.

The invention relates to the technical field of hoisting equipment, and provides a lithium battery unmanned monorail hoist which comprises a suspension track and a hoist assembly, the hoist assembly comprises a car body unit, a hoisting and conveying unit and a suspension unit, the suspension unit is arranged on the suspension track, and the suspension unit comprises a power suspension unit and a load suspension unit. The vehicle body unit is connected with the power suspension unit, the hoisting conveying unit is connected with the load suspension unit, the load suspension unit comprises a suspension beam, load frames, load wheels and guide wheels, the load frames are arranged at the two ends of the suspension beam and comprise mounting ends on the two sides of a suspension rail, and the guide wheels and the load wheels are arranged at the mounting ends. The guide wheels abut against the guide side faces of the suspension rails, and the load-carrying wheels abut against the load-bearing faces of the suspension rails vertically. The problems that in the prior art, when a traveling wheel body of a suspension type rail crane faces a heavy load, due to the fact that the contact face is incomplete, the service life of the wheel body and components of the wheel body is prolonged, and the operation stability is poor are solved.

The invention discloses wafer cleaning equipment, a wafer chuck thereof and a wafer cleaning method, and belongs to the technical field of semiconductor process equipment. The wafer chuck comprises a chuck base body, an air injection assembly and a plurality of wafer lifting shafts, the air injection assembly and the wafer lifting shafts are arranged on the chuck base body, the chuck base body is provided with a bearing face used for bearing a wafer, and an air outlet of the air injection assembly is located in the central area of the bearing face and used for injecting air between the bearing face and the wafer. The multiple wafer lifting shafts are distributed on the periphery of an air outlet of the air injection assembly in the circumferential direction of the bearing face in a surrounding mode, each wafer lifting shaft can move relative to the chuck base body, each wafer lifting shaft is provided with an arc-shaped inclined table, each arc-shaped inclined table is provided with an inclined extending face extending in the circumferential direction of the corresponding wafer lifting shaft, and the inclined extending faces are used for bearing the edge of a wafer. When the wafer lifting shaft moves relative to the chuck base body, the wafer can move to different height positions along the inclined extending face. According to the invention, the height of the wafer can be accurately positioned, and the wafer cleaning efficiency is improved.

The invention relates to a system comprising at least one lightweight pallet and multiple similarly designed containers. Each container has four side walls and container base. The system includes stacking pins as separate components. The pallet features an upper deck with a bearing surface, supported by feet and / or runners, and incorporates first stacking pin receivers. Each container base is provided with at least one second stacking pin receiver. These receivers are dimensioned for insertion of a stacking pin, allowing a container to be securely fixed to the pallet. The stacking pin can be stably arranged in two positions: in the first, it engages the first receiver on the container's side while protruding over the bearing surface to engage the second receiver; in the second, it is countersunk in the first receiver, forming a clamping fit with the upper deck or its thread.