303 results about "Freewheel" patented technology

A robotic pool cleaning vacuum, includes a chassis, a suction duct topping the frame and opening into a filter bag placed above, and an impeller placed inside the duct to suck up debris via a suction port and push it into the filter bag, the chassis including a motor axle drawing the robot, the axle includes two drive wheels driven by a single motor, and an axis connecting the drive wheels transversely to the movement of the robot, the motor being configured to invert its direction of rotation in contact with a wall, the robot further includes a third free wheel for greater stability and maneuverability.

The invention relates to a cable feed device (1) for a robot (2), comprising: - a rotatably drivable first cable drum (8); - a rotatably mounted second cable drum (9), wherein the cable drums (8, 9) are at least indirectly connected to a first segment (4); - a deflection roller (14), which is operatively connected to a second segment (5) pivotably arranged about an axis of rotation (24) relative to the first segment (4); - a cable (6), which is wound on the deflection roller (14) and the free ends of which are each fastened to one of the cable drums (8, 9); and - a first freewheel (15) and a second freewheel (16) which are operatively connected to the deflection roller (14), wherein the first freewheel (15) moves into a coupling state when the deflection roller (15) is rotated in a first direction of rotation, wherein the second freewheel (16) moves into a coupling state when the deflection roller (14) is rotated in a second direction of rotation counter to the first direction of rotation, and wherein a cable feed drive (17) with a transmission ratio not equal to 1 is operatively arranged between the first freewheel (15) and the second segment (5) or between the second freewheel (16) and the second segment (5). The invention also relates to a robot (2) having such a cable feed device (1).

The invention relates to a drive device (2) for a bicycle (1), comprising a pedal crank shaft (19), a first electric machine (18), a first partial transmission (6), a second electric machine (49), and a second partial transmission (7), wherein a first transmission element of the first partial transmission (6) is operatively connected to the first electric machine (18), wherein a second transmission element of the first partial transmission (6) is operatively connected to a second transmission element of the second partial transmission (7), wherein a third transmission element of the first partial transmission (6) is operatively connected to an output gear (8), wherein a first transmission element of the second partial transmission (7) is operatively connected to the second electric machine (49), and wherein a third transmission element of the second partial transmission (7) is fixed to a housing (3), and wherein a freewheel (14) is arranged between the pedal crank shaft (19) and the second transmission element of the first partial transmission (6).Furthermore, the invention relates to a bicycle (1) with such a drive device (2).

A method for controlling an electromechanical brake). The electromechanical brake includes an electric motor which acts on a brake actuator via a gear unit to generate a braking force. A switchable and bistable freewheel locking device, via which a brake release direction of the brake actuator can be locked, is provided to lock the gear unit. The method includes moving back the brake actuator after a braking operation by a fixed predefined distance and controlling the locking device to fix the brake actuator in the retracted position.

A bicycle component for a bicycle freewheel unit, wherein the freewheel unit includes a rotary unit and a toothed disk device coupled with the rotary unit. The toothed disk device includes an end toothing with axial engagement components for engaging corresponding engagement components of another toothed disk device. The toothed disk device and the rotary unit are each configured as coupling components coupled to one another, and include a radial toothing each, for engaging with one another, and which are commonly rotatable. The rotary unit and the toothed disk device are movable in a peripheral direction relative to one another between a driving position and a rest position, so that prior to torque transmission starting, a coupling component is rotated in the driving direction about a clearance angle of at least 5°, until torque can be transmitted, when the two radial toothings have previously been in the rest position.

The invention relates to a drive device (2) for a bicycle (1), comprising a pedal crank shaft (19), a first electric machine (18), a first partial transmission (6), a second electric machine (49), and a second partial transmission (7), wherein a first transmission element of the first partial transmission (6) is operatively connected to the first electric machine (18), wherein a second transmission element of the first partial transmission (6) is operatively connected to a second transmission element of the second partial transmission (7), wherein a third transmission element of the first partial transmission (6) is operatively connected to an output gear (8), wherein a first transmission element of the second partial transmission (7) is operatively connected to the second electric machine (49), and wherein a third transmission element of the second partial transmission (7) is fixed to a housing (3), and wherein a freewheel (14) is arranged between the pedal crank shaft (19) and the second transmission element of the first partial transmission (6).Furthermore, the invention relates to a bicycle (1) with such a drive device (2).

A bicycle hub includes an axle and a hub body disposed on the axle and having an abutting portion and an inner bevel gear in an end portion of the hub body. A ratchet seat rotatably fits around the axle and includes a freehub body and an insertion tube inserted into the end portion of the hub body. An outer bevel gear fits around the insertion tube to be slidable only in an axial direction, meshes the inner bevel gear, and is abutted by the abutting portion to be retained in the inner bevel gear. An elastic body adapted to push the outer bevel gear toward the inner bevel gear is disposed on the ratchet seat.

A freewheel assembly has a hub, a brake mechanism, and at least one switch. The hub has an axle, a hub shell mounted around the axle, a drive screw disposed at one of two ends of the hub shell; and a sprocket mounted around the drive screw and having an inner shell and an outer shell. The inner shell is screwed with the drive screw and has a first engaging notch. The outer shell is mounted around the inner shell and has a second engaging notch. The brake mechanism has a clutch cone configured to be driven by the drive screw to move along the axle and at least one brake shoe disposed to an exterior circumference of the clutch cone. Each switch is screwed to the outer shell and has an engaging block engaging with at least one of the first engaging notch and the second engaging notch.

An electric drive unit (50) is mechanically connected to the input element (62) of a reduction gear (60) for applying a drive force. An output element (40) is mechanically connected to an output element (62) of the reduction gear (60) via a freewheel (20) for outputting a torque. The freewheel (20) has at least one pivotable clamping element (21) with a clamping surface (22) whose curvature is adapted to the curvature of an inner circumferential surface (24) of an outer ring (26) of the freewheel (20). The clamping surface (22) restricts the pivoting of the clamping element (21) to a locked position in which the clamping surface (22) is aligned along the inner circumferential surface (24). The clamping element (21) is designed to transmit a locking torque when the clamping element (21) is pivoted into the locking position, and to slip when the output torque to be transmitted is greater than the locking torque.

When a differential half shaft 11 on one side is not stressed due to slipping or suspension, and rotation of a differential shell 1 serves as input to drive a first planetary gear 12 and a second planetary gear 3 to revolve, the first planetary gear 12 and the second planetary gear 3 drive an inner gear ring 5 on a half shaft on the other side to rotate in the same direction. Due to the fact that the first planet bevel gear 8 and the second planet bevel gear 7 are fixedly connected and coaxially arranged, and the diameter of the inner gear ring 5 is far larger than that of the half shaft bevel gear 13, the differential mechanism shell 1 rotates to enable the inner gear ring 5, the first planet bevel gear 8 and the second planet bevel gear 7 on the other side to rotate, and the first planet bevel gear 8 and the second planet bevel gear 7 are driven to rotate. The first planet bevel gear 8 and the second planet bevel gear 7 are evenly distributed, force generated by locking of the inner gear ring 5 only pushes the second planet bevel gear 7 to rotate, and the direction of the force at the meshing position of the first planet bevel gear 8 and the second planet bevel gear 7 is the same as the rotating direction of the differential shell 1, so that the first planet bevel gear 8 and the second planet bevel gear 7 are in a locked state, and then the differential shell 1 is released. Therefore, the defect of a single cantilever of a free wheel in a free wheel type antiskid differential mechanism is overcome, and the whole structure is more durable.

A drive arrangement for a bicycle includes a pawl freewheel, the pawl freewheel having a first ring, at least two pawls movably mounted on the first ring, and a second ring having a toothing. The at least two pawls are unevenly spaced in the circumferential direction on the first ring. The drive arrangement further includes at least one sensor device configured to detect a deformation of the first ring of the pawl freewheel due to an applied drive force.

A computer system controls a powertrain system of a vehicle. The computer system has processing circuitry configured to selectively operate the powertrain system in a number of operational modes, comprising at least a freewheeling mode, in which an output shaft of the engine is non-rotating, and the engine is disconnected from the one or more drive wheels, wherein the processing circuitry is further configured to: predict fuel saving in response to a potential up-coming freewheeling mode period, the fuel saving being determined from engine-idle fuel consumption data; predict a loss of kinetic energy for restarting the engine in the freewheeling mode using a controllable clutch; predict fuel consumption needed to regain the predicted loss of kinetic energy; compare the predicted fuel saving with the predicted fuel consumption; determine to control the powertrain system into the freewheeling mode based on the comparison; and control the powertrain system into the freewheeling mode.

An adjustable freewheel hub assembly has a hub component, a coaster brake mechanism, and an adjusting switch. The hub component has an axle, a hub shell, a helix hub driver, and a sprocket. The helix hub driver has a pawl groove and a first engaging notch formed on its periphery. The sprocket is sheathed onto the helix hub driver, is hollow, and has a ratchet teeth construction formed on an inner wall of the sprocket and a second engaging notch. The coaster brake mechanism is disposed in the hub shell and is drivable by the helix hub driver. By the adjusting switch engaged in or detached from the first engaging notch and the second engaging notch, the freewheel hub assembly can be adjusted between a fixed-gear mode and a single-speed mode to have different functions.

The invention discloses a self-adaptive riding speed control system and method, and relates to the technical field of vehicle control, the system collects motion state data of a riding vehicle in real time through a sensor group installed on the riding vehicle, and after preprocessing, a vehicle attitude data set and a riding condition data set are formed; the method comprises the following steps: performing gradient state evaluation by calculating a gradient trend index slo, performing pedaling frequency stability analysis when the evaluation is about to enter an uphill stage and a downhill stage, calculating a pedaling frequency stability index wca through a riding condition data set, and then combining the pedaling frequency stability index wca with the gradient trend index slo to construct a comprehensive tooth ratio stability index Gopt to perform comprehensive riding stability evaluation. Therefore, the rationality of tooth ratio adjustment is judged, a tooth ratio switching instruction of the front disc and the rear flywheel is sent out, self-adaptive adjustment and control of the tooth ratio under the stable states of different gradients and different pedaling frequencies are achieved, the power matching and energy utilization efficiency in the riding process is effectively improved, the load of a rider is relieved, and the riding stability is enhanced.

A valve pump unit having an electric motor, a reduction gearbox driven by the electric motor, a first pump stage driven by the electric motor, a second pump stage driven by the electric motor, a multiway valve adjusted via the reduction gearbox and having heat transport medium channels for providing at least two switching positions between a first heat transport medium circuit and a second heat transport medium circuit, and also a common housing section for accommodating the electric motor, the multiway valve, the reduction gearbox and also the first pump stage and the second pump stage. In pumping operation, the electric motor is rotated in a first direction, and the reduction gearbox is uncoupled from the electric motor via a freewheel. The reduction gearbox may be operated in a second direction of rotation of the electric motor, to adjust the multiway valve.

The invention discloses an automatic collection device for marine floating garbage, and belongs to the field of marine environmental protection equipment. The device comprises a supporting frame, a conveying belt mechanism, a power transmission mechanism, a tension adjusting mechanism and a material receiving assembly. The supporting frame is of a detachable modular structure and is fixed stably. The conveyor belt mechanism adopts a hollow net-shaped flat belt, so that the draining function is realized; the power transmission mechanism captures wave energy through a floating block, and one-way rotation of a driving roller is achieved through a gear transmission system and an overrun clutch. The tensioning adjusting mechanism can flexibly adjust the tensioning degree of the conveying belt; and the receiving assembly realizes garbage collection and conveyor belt cleaning. The device does not need extra energy, is efficient and stable in transmission, convenient to install and maintain, high in collection efficiency, low in cost and suitable for various sea area environments such as coast and gulf, can effectively solve the problem of collection of marine litter, and has a good application prospect.

The invention discloses a board collecting machine with a secondary outer layer prepreg stacking function, and relates to the technical field of circuit board production equipment. Comprising steel bar trusses; the moving assembly is arranged on the steel bar truss; the number of the core plate clamping jaw assemblies is two, and the two core plate clamping jaw assemblies are symmetrically arranged on the moving assembly. The positions of the core plate clamping jaw assemblies and the positions of the plate tables are distributed at intervals from top to bottom. The two opposite ends of each plate table are each provided with a plurality of groove bodies. The moving assembly comprises a sliding seat horizontally arranged on the steel bar truss in a sliding mode, a lifting assembly is arranged on the sliding seat, and a guide rail is horizontally arranged on the lifting assembly. The core plate clamping jaw assembly comprises a sliding block horizontally arranged on the guide rail in a sliding mode, a clamping jaw cross beam is horizontally arranged on the sliding block, a plurality of air cylinders are vertically arranged on the clamping jaw cross beam at intervals in the length direction, a core plate hook plate is arranged below the air cylinders, and a free wheel is rotationally arranged on the core plate hook plate. The transferring and stacking device has the advantages that the transferring and stacking stability of the sub-outer layer prepregs is improved, and damage can be avoided.

The utility model discloses a double-battery electric power-assisted bicycle, which belongs to the technical field of bicycles and comprises a frame, a front wheel and a rear wheel are respectively arranged at the front end and the rear end of the frame, a center shaft is arranged at a five-way position of the frame, pedal cranks are respectively arranged on two sides of the center shaft, a crankset is arranged on the inner side of one of the pedal cranks, and the crankset is arranged on the inner side of the other of the pedal cranks. The chain wheel is connected with a flywheel of the rear wheel through a transmission mechanism, a middle motor capable of driving the middle shaft to rotate is arranged at the five-way position of the frame, a mounting cavity is formed in a lower pipe of the frame, a main battery is arranged in the mounting cavity, and an auxiliary battery is arranged on the rear side of a middle pipe of the frame. The main battery and the auxiliary battery are electrically connected with the middle motor. According to the utility model, the configuration of double batteries is realized, longer cruising ability can be provided, the requirement of longer-distance riding is met, the cruising mileage after single charging is prolonged, and the condition of frequent charging by a rider is reduced.

A hybrid powertrain for a work vehicle comprises an internal combustion engine, a hydraulic pump, an electric motor, and a freewheel clutch. The work vehicle may include hydraulic actuators and work tools driven by the hydraulic pump, as well as electric drive motors driven by the electric motor. The freewheel clutch couples the engine, pump, and electric motor so that, in a first mode, the engine can drive the electric motor and the pump; in a second mode, the engine and electric motor can simultaneously drive the hydraulic pump; and in a third mode, the electric motor can drive the hydraulic pump with the clutch disengaged. A torsional damper can couple the freewheel clutch to the engine's flywheel.

Valve-pump unit (VPE) with a function that can be operated depending on the direction of rotation of an electric motor, a single electric motor (EM) to drive a first pump stage (PS1) and a second pump stage (PS2) and to adjust a multi-way valve (MWV), a reduction gear (RG) which can be driven by the electric motor (EM), a first pump stage (PS1) driven by the electric motor (EM) for pumping a heat transfer medium in a first heat transfer medium circuit, a second pump stage (PS2) driven by the electric motor (EM) for pumping a heat transfer medium in a second heat transfer medium circuit, a multi-way valve (MWV) adjustable via the reduction gear (RG) with heat transfer medium channels (6) to provide at least two switching positions between the first heat transfer medium circuit and a second heat transfer medium circuit of a heat transfer medium system and a common housing section (Gg) for accommodating the electric motor (EM), the multi-way valve (MWV), the reduction gear (RG), as well as the first pump stage (PS1) and the second pump stage (PS2), wherein in a pump operation, in a first direction of rotation of the electric motor (EM) the reduction gear (RG) is decoupled from the electric motor (EM) via a freewheel (FL), wherein the reduction gear (RG) can be operated in a second direction of rotation of the electric motor (EM) opposite to the pump operation for adjusting the multi-way valve (MWV).

The utility model provides a track-variable manual-automatic integrated bicycle, relates to the technical field of fitness equipment, and solves the problems that an existing fitness bicycle is relatively single in use function and cannot meet the experience requirements of various consumers. The electric bicycle comprises a bicycle frame, a pair of pedals, a flywheel rotationally connected to one end of the bicycle frame, a crank connecting rod assembly, a belt transmission assembly and an electric assembly, wherein the crank connecting rod assembly and the belt transmission assembly are arranged on the bicycle frame and used for transmission between the pedals and the flywheel, and the electric assembly is used for driving the pedals to operate automatically. The track adjusting assembly is arranged at the bottom of the end, close to the flywheel, of the frame and used for adjusting the motion track of the pedals, and the resistance adjusting device is arranged on the frame and used for adjusting the resistance of the flywheel. The hand-operated and power-driven electric control device has the advantages that the movement track can be adjusted according to needs, manual operation and power-driven integrated free switching is achieved, and the requirements of different users are met.

An adjustable freewheel hub assembly has a hub component, a coaster brake mechanism, and an adjusting switch. The hub component has an axle, a hub shell, a helix hub driver, and a sprocket. The helix hub driver has a pawl groove and a first engaging notch formed on its periphery. The sprocket is sheathed onto the helix hub driver, is hollow, and has a ratchet teeth construction formed on an inner wall of the sprocket and a second engaging notch. The coaster brake mechanism is disposed in the hub shell and is drivable by the helix hub driver. By the adjusting switch engaged in or detached from the first engaging notch and the second engaging notch, the freewheel hub assembly can be adjusted between a fixed-gear mode and a single-speed mode to have different functions.

Freewheel clutch (630, 630A, 630B) for use in a power transmission device with hydraulic fluid, wherein the freewheel clutch (630, 630A, 630B) comprises the following: a coupling arrangement (20, 120, 220, 420, 520, 600, 600A, 600B) with an inner ring (36) and an outer ring (22) rotatable with respect to the inner ring (36), wherein the outer ring (22) has several locking structures consisting of inner ratchet teeth (34) and outer ratchet teeth (44); and a ratchet finger arrangement (48, 448, 548, 632) with an active ratchet finger (50) which is for movement between a first position displaced from engagement with the inner ratchet teeth (34) and outer ratchet teeth (44), which defines a free-running mode, and a second position engaged with the inner ratchet teeth (34) and outer ratchet teeth (44), which defines a locked mode by which the inner ring (36) is supported, wherein the inner ring (36) and / or the active locking finger (50) has / have an anti-disengagement feature configured to assist in holding the actuator element in its first position during a rotation of the outer ring (22) relative to the inner ring (36) by counteracting hydraulic forces applied by the hydraulic fluid to the active locking finger (50), characterized in that the anti-disengagement feature counteracts the hydraulic forces applied to the active locking finger (50) by diverting the fluid to flow in a path configured to push the active locking finger (50) into its first position.

The present application belongs to the technical field of vehicle control. Disclosed are a fault processing method for a centralized distributed electric drive system, and a vehicle. The centralized distributed electric drive system comprises an electric-motor controller, and a first electric motor and a second electric motor that are coaxial with each other. The method is applied to an electric-motor controller, and comprises: when a preset fault occurs in a first electric motor or a second electric motor, the electric-motor controller controlling the first electric motor and the second electric motor to enter a safety mode, wherein the preset fault is a fault of the highest severity level, and the safety mode comprises a free wheel (FW) mode; using the electric motor that has entered the FW mode as a current electric motor, and when the preset fault occurs in the current electric motor, controlling the current electric motor to maintain the FW mode; and when the preset fault does not occur in the current electric motor, controlling the current electric motor to exit the FW mode. In the present application, when a fault of the highest severity level occurs in any electric motor, both coaxial electric motors are caused to enter a safety mode, so as to ensure synchronized instantaneous responses of the left and right wheels, thereby improving the safety of a vehicle.

The utility model discloses a safety failure alarm device for a roller type overrun clutch of a small press machine, which comprises a machine body, a crankshaft is rotatably arranged on the machine body, a flywheel is fixedly arranged on the outer surface of the crankshaft, and the roller type overrun clutch is arranged between the outer surface of the crankshaft and the flywheel. The machine body is further rotationally provided with a clutch control mechanism used for achieving a clutch function on the roller type overrun clutch, one side of the machine body is provided with a sensing assembly used for recognizing whether the clutch control mechanism and the roller type overrun clutch are clamped in place or not, the clutch control mechanism comprises a control rod, and the outer surface of the coupling is provided with a coupling notch. When the stop pin on the clutch handle body abuts against the circumferential face of the coupling and does not abut against the interior of a notch of the coupling, the proximity switch and the induction block conduct continuous induction, the alarm in the external space gives out continuous buzzing alarm sound, an operator is reminded to stop working immediately, and therefore the damage of the press machine to the operator is effectively avoided.

Drive system that includes: an inner race element (14); an outer race element (16); a first disengageable clamping element coupling (18) arranged between the inner race element (14) and the outer race element (16), wherein the first disengageable clamping element coupling (18) has a drive direction and a free-running direction; and a second disengageable clamping element coupling (20) arranged between the inner running ring element (14) and the outer running ring element (16), wherein the second disengageable clamping element coupling (20) has a drive direction and a freewheel direction which are opposite to the drive direction and to the freewheel direction of the first disengageable clamping element coupling (18); characterized by the fact that (i) the first disengageable clamping clutch (18) and the second disengageable clamping clutch (20) each include a disengagement mechanism to prevent the first and second disengageable clamping clutches (18, 20) from being engaged in a drive direction; wherein the release mechanism includes an extendable ring (42) which engages the clamping elements of the first disengageable clamping element coupling (18) or the second disengageable clamping element coupling (20), and when it is stretched, prevents the clamping elements from engaging the inner running ring element (14); or (ii) the first disengageable clamping element coupling (18) and the second disengageable clamping element coupling (20) each contain several clamping elements (30) with a clamping surface (30d) for engaging the inner running ring element (14) and wherein the several clamping elements (30) each contain a recess (30e) within the clamping surface (30d), wherein in the recess (30e) each of the clamping elements (30) receives an expandable ring (42).

The application discloses a one-way self-locking device for a linear driving motor, which comprises a friction ring sleeved on the tail end of a motor rotating shaft away from the output end of the motor rotating shaft, a torsion spring sleeved on the friction ring and a fixing base sleeved outside the torsion spring and fixed on a first end cover of the motor, one end of the torsion spring is fixed on the fixing base, and the other end of the torsion spring is fixed on the friction ring; the friction ring is an elastic circular ring composed of a plurality of arc-shaped pieces connected in a head-to-tail mode, the friction ring is in interference fit with the motor rotating shaft and has a pre-tightening friction force; the friction ring and the fixing base are provided with a torsion spring tension structure which is capable of releasing the torsion spring when the motor rotating shaft rotates in one direction and rotating the torsion spring and circularly compressing the friction ring to realize one-way self-locking when the motor rotating shaft rotates in the opposite direction, and the torsion spring gap is sleeved on the friction ring. The one-way self-locking device has the advantages that the friction ring itself has a radial elastic force, the friction surface is complete and continuous, the friction force is stable, and the wear is relatively small.

A freewheel hub for a bicycle includes a driver and a hub sleeve, which are each supported on a hub axle to be rotatable about a common axis of rotation, a detent body arrangement having at least one detent body, supported in a radial detent body recess to be displaceable between a locking position and a release position, and a preloading device, which is configured to preload the detent body towards the locking position, wherein the detent body recess is provided in a component comprising the driver and the hub sleeve, while the other has a radial driving tooth system or is connected for conjoint rotation to the latter, wherein the surface of the detent body has a coupling surface, which rests against a contact surface of the detent body recess in the locking position, while an engagement portion of the detent body engages in the driving tooth system.

Wheel system comprising a wheel having a hub with a main axis (X), the hub comprising an inner face with an inner conical surface; a tubular element; a main shaft inserted into the tubular element; a hand-rim comprising an extension portion having a threaded portion; a braking pad having a braking surface and a first conical surface; a coupling member translatably movable axially between a first position in which it rotatably links the hand-rim and the hub, and a second position for braking the hub; a freewheel arranged between the tubular element and the hub; and a blocking part for blocking the rotation of the tubular element relative to the frame.

The utility model provides an electric vehicle plastic part injection molding process excess material recycling device which comprises an excess material collecting box, a feeding hopper and a filter screen and further comprises a filter screen knocking assembly, the filter screen knocking assembly comprises a knocking shell, a crank connecting shaft and a flywheel, and the knocking shell is in an inverted triangle shape and is fixed to the middle of the bottom end of the filter screen; the flywheel is integrally arranged on the crank connecting shaft, and the flywheel and the crank connecting shaft are distributed in the knocking shell. According to the filter screen knocking assembly, the filter screen knocking assembly comprises a knocking shell, a crank connecting shaft and a flywheel, the knocking shell is in an inverted triangle shape and is fixed to the middle of the bottom end of the filter screen, and the flywheel is integrally arranged on the crank connecting shaft and distributed in the knocking shell together with the crank connecting shaft; the arranged driving mechanism is used for applying power, the crank connecting shaft can be driven to continuously rotate in a reciprocating mode, blockages at meshes of the filter screen can be knocked out, meanwhile, materials located on the filter screen can be better screened, and excessive accumulation is avoided.