Abstract: A mobile cleaning robot can include a body, a drive wheel, and a wheel stop. The drive wheel can be connected to the body and can be operable to move the mobile cleaning robot about an environment. The wheel stop can be movable with respect to the body and the drive wheel between a stop position and a release position. The wheel stop can be engageable with the drive wheel in the stop position to limit vertical travel of the drive wheel with respect to the body.

Abstract: A medium feeding apparatus includes a feed roller that feeds media. A separation roller nips the media together with the feed roller to separate it and is rotated in a first direction to feed the media. A motor applies driving torque to the separation roller in a second direction opposite to the first direction. A torque limiter, when rotation torque applied to the separation roller in the first direction exceeds a preset upper torque limit, causes the separation roller to rotate at idle in the first direction independently of the driving torque. During feeding operations, including feeding of first and second media, a controller that controls the motor provides a break period in which the motor is not driven. The break period contains the timing when a rear edge of the first medium leaves a nip position between the feeding and separation rollers.

Abstract: A sheet feeding apparatus includes: a storage part that stores a sheet, and a feeding part that has a feeding roller for feeding the sheet. The storage part and the feeding part are configured to be integrally inserted/withdrawn into/from an apparatus enclosure. The feeding roller is moved from a feeding position to a retracting position before the storage part and the feeding part are withdrawn from the enclosure.

Abstract: A sheet feeding apparatus includes a sheet supporting portion to support a sheet, a feeding member to contact an upper surface of the sheet supported on the sheet supporting portion and feed the sheet, and a drive motor to rotate in a first direction and in a second direction opposite to the first direction. In addition, a lifting mechanism is connected to the drive motor to lift the sheet supporting portion and lower the feeding member in a case where the drive motor rotates in the first direction, and to lower the sheet supporting portion and lift the feeding member in a case where the drive motor rotates in the second direction.

Abstract: An apparatus (1) for processing plastic cups (2), adapted to be filled with coffee or other products, whether solid or liquid, and to be closed with respective lids to form corresponding capsules, comprises: a plurality of pockets (50) for housing the cups (2); an infeed station (4) for receiving the cups (2) and placing them in respective pockets (50) of the plurality of pockets (50); at least one tool (31) for applying a process to a rear face (23B) of an annular flange (23) of a cup (2) housed a respective pocket (50), to form a sealing profile (230); an outfeed station (6) configured to release the cups (2) with the sealing profile (230) formed on them.

Abstract: A sheet conveyance apparatus includes a cover unit, a base unit, a roller unit configured to be detachable from the cover unit, and comprising a roller configured to convey the sheet along a conveyance path and a holder comprising an arm portion configured to extend in a width direction orthogonal to a sheet conveyance direction, a cam configured to swing the holder by rotating, and a cover member configured to be openable and closable with respect to the cover unit and configured to cover at least a portion of the arm portion against the conveyance path in a closed state, the cover member being opened by being pressed by the arm portion in a case where the roller unit is detached from the cover unit.

Abstract: A holding member is configured to hold a feed member and movable up and down. A lever member is configured to pivot on a pivot shaft and includes a contact portion configured to be in contact with the holding member. An elastic member is connected to the lever member and configured to urge the holding member downward through the lever member. The elastic member is disposed such that, when viewed in an axial direction of the pivot shaft of the lever member, a distance from the pivot shaft to a line of action of a force applied by the elastic member to the lever member in a case where the feed member is located at a first position is shorter than a distance from the pivot shaft to the line of action in a case where the feed member is located at a second position below the first position.

Abstract: A medium conveyance device includes a guiding member that is movably supported on a frame, a pick roller that is rotatably supported on the guiding member and that rotates to feed a medium that is placed on a tray to a feed roller, and a joint unit that transmits a rotation force from a drive shaft to the pick roller.

Abstract: An image forming apparatus improved in a setting process for a recording medium to thereby make it possible to prevent print processing from failing to be executed. In the image forming apparatus including a plurality of sheet feeders for storing recording sheets, when recording sheets are stored in one of the sheet feeders, at least one of the recording sheets is conveyed from the corresponding sheet feeder, and the type of the conveyed recording sheet is identified. Then, the identified type of the recording sheet is set as the type of the stored recording sheets. This makes it possible to prevent occurrence of a situation in which print processing is not executed because the identified type of the recording sheet does not match the set type of the recording sheets, whereby it is possible to prevent print processing from failing to be executed.

Abstract: The present subject matter describes determination of amount of print media present in an input tray of a printing system. In an example implementation of the present subject matter, a current operating torque of a motor that moves a pick arm for drawing print media from the input tray is monitored. The current operating torque is monitored while the pick arm is moved between a rest position and a pick-ready position. Based on the monitored operating torque, it is determined whether amount of print media present in the input tray is one of below and above a predefined amount of print media.

Abstract: In an example, a load stop may comprise a stop paddle, a paddle link, a swingarm engaged with a motive element, and a cam gear to engage the swingarm with the paddle link. The paddle link may move the stop paddle from a locked position, to a gathering position, and to a stowed position. The swingarm may transfer the motion of the motive element to the cam gear such that the cam gear is to move in a first direction, the cam gear to drive the paddle link to move the stop paddle from the locked position, to the gathering position, and to the stowed position when the motive element moves in a first drive direction, and the swingarm moves the cam gear in the first direction.

Abstract: When it is judged that a predetermined operation for eliminating a cause for stopping a job is being executed, a following job is restricted from being executed prior to a stopped job.

Abstract: A sheet cassette connectable to a printer includes a case, a spring, a cover, and a connecting part. The case stores a recording sheet. The spring is provided on the case. The cover covers the case and the spring and slides relative to the case to expose the spring. The connecting part is attached to the case and is connectable to the printer. The spring is exposed to press a recording sheet placed on the cover toward a position at which the printer is to be located when connected to the sheet cassette.

Abstract: A tray locking mechanism includes a tray on which a sheet is disposed, a moving head that processes the sheet that is disposed on the tray as the moving head moves along the sheet, a tray locker that locks the movement of the tray, and a housing that houses the tray and includes a retainer. The tray locker includes a retaining claw that locks the movement of the tray by locking to the retainer. While the moving head is positioned at a position away from a stand-by position, the retaining claw is locked to the retainer as a result of the moving head separating from the tray locker, and while the moving head is positioned at the stand-by position, the retaining claw is disengaged from the retainer as a result of the moving head pushing the tray locker.

Abstract: A sheet conveying apparatus, including: a sheet storage portion; a roller to convey sheets by rotating about a rotation axis; an arm rotatably supporting the roller and pivotable about an arm pivot axis; a presser plate pivotable about a presser-plate pivot axis; and a pivot mechanism to pivot the presser plate such that a contact angle, which is an angle defined upstream in a sheet conveyance direction by the arm and an uppermost one of the sheets contacting the roller, is less than a maximum angle in a time period from a sheet maximally loaded state to a sheet minimally loaded state, the maximum angle being an angle defined upstream in the conveyance direction by: only one sheet assumed to be placed on the presser plate which is the presser plate in the maximally loaded state; and the arm the roller of which contacts the one sheet.

Abstract: An image forming apparatus comprises a tray, a conveyor, a detector and a movement mechanism. The tray accommodates at least one document. The conveyor conveys the document placed on the tray. The detector detects that the document is placed on the tray. The movement mechanism moves the tray from a first position to a second position closer to the conveyor than the first position based on the detection that the document is placed on the tray, and after moving the tray from the first position to the second position, moves the tray to the first position based on a setting of a mixed stacking mode in which mixing of the documents with different sizes on the tray is permitted.

Abstract: Disclosed is a sheet feeding apparatus including a tray unit capable of stacking a sheet at an opened position; a feeding member which feeds the sheet stacked on the tray unit; a feed supporting portion which supports the feeding member such that the feeding member is capable of moving to a feeding position for feeding the sheet stacked on the tray unit and to a storage position at which the feeding member is stored in the apparatus main body; and an urging portion which urges the feeding member toward the feeding position, wherein the feed supporting portion includes an abutting portion which abuts against a region other than a sheet stacking region of the tray unit for moving the feed supporting portion and for moving the feeding member to the storage position when the tray unit moves from the opened position to the closed position.

Abstract: A sheet feeding apparatus includes a feed roller configured to feed a sheet in a feeding direction, a drive unit to drive the feed roller, a separation roller driven by the drive unit through a torque limiter in a direction against the feeding direction, and a pair of conveyance rollers. In addition, a control portion executes a first control mode in which a first sheet is conveyed and a second control mode in which a second sheet having a lower basis weight than that of the first sheet is conveyed. The control portion stops the drive unit with the sheet nipped at a separation nip portion and at a conveyance nip portion in each of the first and second control modes, and a timing when the drive unit is stopped by the control portion in the second control mode is earlier than a timing when the drive unit is stopped by the control portion in the first control mode.

Abstract: First and second detecting members that detect a sheet or an object lifted beyond a delivery position at which the sheet is delivered is provided, and the second detecting member is configured to be activated in conjunction with activation of the first detecting member. Thus, with a simple configuration, it is possible to detect, over a wide area above a sheet loading section, a sheet or an object placed at a wrong position.

Abstract: A sheet conveying device includes a separator to separate a sheet from sheets. The separator includes a separation conveyor; a separation resistance member to press against the separation conveyor via the sheet; a resistance-member holder; a biasing member to contact and bias the resistance-member holder to press the separation resistance member toward the separation conveyor, the resistance-member holder to rotate about a resistance-member rotary shaft to separate from the biasing member in detaching from an apparatus body; and a biasing-member holder configured to rotate about a biasing-member rotary shaft to more incline the biasing member in a state, in which the biasing member is spaced apart from the resistance-member holder, in a moving direction of the resistance-member holder to detach from the apparatus body than the biasing member in a biasing state in which the biasing member biases the resistance-member holder in contact with the resistance-member holder.

Abstract: A sheet feeding apparatus includes a sheet presence/absence detection sensor configured to detect presence or absence of a sheet on a stacking device, a sheet surface detection sensor configured to detect that a stacking tray is raised to enable a sheet to be fed, a separation cam, and a control unit. The control unit is configured to determine that the mounting state of a feeding holder to a holder support unit is defective when the sheet surface detection sensor detects that the sheet can be fed when the sheet presence/absence detection sensor detects absence of a sheet before sheet feeding processing by a pickup roller.

Abstract: A self-correction recognition method and device for a valuable document recognition device is provided. The method includes: extracting a feature of a valuable document; determining whether the feature falls in a discriminant library of any preset category, and obtaining a substitutive centroid according to a feature centroid and the feature in a case that the feature falls in a discriminant library of any preset category; and updating the discriminant library of the category by replacing the feature centroid of the category with the substitutive centroid. The discriminant library is pre-constructed according to the feature centroid of the category, and the feature centroid is calculated from a feature of the category.

Abstract: The sheet feed device includes a sheet containing cassette with a sheet stacking plate therein, a sheet feed part enabled to feed a sheet within the sheet containing cassette set in a setting position, a first sensing mechanism, a lift mechanism, a drive mechanism, and a controller. The lift mechanism includes a cassette-side coupling member for transmitting driving force to the sheet stacking plate. The drive mechanism includes a main body-side coupling member coupled with the cassette-side coupling member. When the first sensing mechanism has sensed that no sheets are stacked on the sheet stacking plate, the controller makes the main body-side coupling member rotate reverse to move down the sheet stacking plate and, even after the sheet stacking plate lowers, makes the main body-side coupling member continue to be rotated reverse so as to move out the sheet containing cassette from the setting position.

Abstract: A base material processing apparatus includes a transport mechanism, a force detection part, a meandering prediction part, a processing part, and a controller. The transport mechanism transports an elongated strip-shaped base material in a longitudinal direction thereof along a transport path aimed by a plurality of rollers of the transport mechanism. The force detection part detects a force applied to a sensing roller in an axial direction of a rotation shaft thereof, the sensing roller being at least one of the plurality of rollers. The controller predicts the meandering state of the base material to output meandering prediction information, based on the force applied to the sensing roller in the axial direction of the rotation shaft thereof. The meandering prediction part corrects the widthwise position of the base material relative to the processing part, based on the meandering prediction information.

Abstract: A sheet supporting apparatus includes a sheet supporting portion supported liftably between a standby position and a lifted position, a lifting portion arranged below the sheet supporting portion, and configured to lift the sheet supporting portion toward the lifted position by pressing the sheet supporting portion from below. The sheet supporting portion includes a supporting surface defining a non-interference region in which a width regulating portion can move in a width direction. A projected portion is provided on the lifting portion, and configured to project upward toward a non-interference region.

Abstract: A printing apparatus that enables a medium container to be detached by moving a hopper with a reduced load with a simple structure is provided.

Abstract: A printing apparatus is provided which is capable of reducing a concern that a medium may remain inside an apparatus main body at the time of pulling out a medium accommodating member.

Abstract: A sheet feeding apparatus includes a feeding rotating member to feed a sheet, and a separating portion to separate and feed one by one the sheet fed by the feeding rotating member. The separating portion includes a separating rotating member to feed a sheet and a separating member to form a separation nip portion by abutting on the separating rotating member. In addition, a sheet stacking portion on which sheets are stacked is disposed to face the feeding rotating member, and a sheet introducing portion guides the sheet toward the separating portion. The sheet introducing portion being is in a downstream side of the sheet stacking portion and positioned above a tangent line at a contacting point between the feeding rotating member and the sheet stacking portion in a vertical direction.

Abstract: A sheet-feeding device includes: a first feeding roller configured to contact a sheet accommodated in a sheet-accommodation portion to feed the sheet; a second feeding roller movable between a non-feeding position and a feeding position; a driving source configured to generate a rotational driving force to the first feeding roller; a transmission portion configured to transmit the rotational driving force to the second feeding roller; a first sensor; a second sensor; and a roller actuating portion. The roller actuating portion is configured to: move the second feeding roller from the non-feeding position to the feeding position in a case where the second detector detects rotation of the first feeding roller is stopped during a sheet-feeding operation; and move the second feeding roller from the feeding position to the non-feeding position in a case where the first sensor detects the sheet-feeding operation is completed for the sheet.

Abstract: A feed module for feeding value documents, in particular bank notes, to a value-document processing apparatus, has a receiving device in which one or more value documents to be processed can be inserted. The receiving device includes a first aligning element which the value documents lying in the receiving device are aligned to with a first edge of the value documents when the receiving device is in a first state, and a second aligning element which the value documents lying in the receiving device are aligned to with a second edge of the value documents when the receiving device is in a second state. A positioning device through which the receiving device is brought from the first state to the second state.

Abstract: In accordance with one embodiment, an image forming apparatus comprises a cassette for paper feed configured to contain a tray capable of stacking papers stored in a packaging member of which one end portion is opened, together with the packaging member; a paper feed section configured to contain a pickup roller which picks up the papers stored in the packaging member from the opened end portion of the packaging member; a regulating member configured to regulate that the packaging member is conveyed from the tray of the cassette; and a protrusion configured to be formed and protrude from the regulating member to cover the opened end portion of the packaging member.

Abstract: A sheet feeding apparatus includes a tray swingably supported by an apparatus body through a link. A link support portion disposed in the apparatus body is engaged with a first end portion of the link. The link support portion includes first and second support parts respectively corresponding to first and second positions of the tray. The link support portion further includes a guide part along which the first end portion of the link moves between the first and second support parts. The guide part has a bent part between the first and second support parts so that a guiding direction in which the first end portion is guided from the first support part toward the bent part differs from a load direction in which the first end portion of the link applies load on the first support part in a case where the tray is positioned at the first position.

Abstract: An image forming apparatus (1) includes an image forming device (5), a conveyor device (L), and a manual paper feed section (8). The conveyor device (L) conveys paper (P). A part of the conveyor device (L) is constituted by a conveyance guide unit (83) and an exterior unit (82). The exterior unit (82) is located opposite to the conveyance guide unit (83) and constitutes a part of an exterior surface of the image forming apparatus (1). The manual paper feed section (8) includes a paper feed roller (821) and a retard roller (831). The paper feed roller (821) is located in the exterior unit (82) and feeds paper (P) placed on a manual feed tray (81) to the conveyor device (L). The retard roller (831) is located in the conveyance guide unit (83) and separates sheets of the paper (P) fed by the paper feed roller (821).

Abstract: In a case where, for example, a certain sheet feeding operation by one of sheet delivery portions is an operation that continues from a sheet feeding operation by another one of the sheet delivery portions in a sheet feed device, a control portion delays output timing, to a feed clutch, of a control signal for feeding a first one of recording sheets, as compared to output timing of control signals for sequentially feeding a second and the following ones of the recording sheets from the same sheet delivery portion.

Abstract: A sheet feeder includes a sheet platen, a pickup roller, a feeding roller, a regulating portion, a driving mechanism, a feeding control unit, a sheet sensor, and a determination processing unit. The feeding control unit executes a feeding operation by rotationally driving the pickup roller and the feeding roller in a state where the regulating portion is located at a retreating position. The sheet sensor is located at a downstream side in the feeding direction of the feeding roller. The determination processing unit determines whether the sheet feeding has succeeded or not based on a signal from the sheet sensor. After a start of the feeding operation, when the determination processing unit determines that the sheet feeding has failed, the feeding control unit once moves the regulating portion located at the retreating position to the abutting position and then executes the feeding operation again.

Abstract: A paper feeding device comprises a storage surface for a stack of papers and being adapted to be move vertically between a first, lower end position and a second, upper end position, and a feeding roll for feeding papers from their position on the storage surface and imparting an uppermost sheet of paper a horizontal displacement. A first mounting device comprises a first vertically movable, preferably pivotable housing adapted to mount or suspend a first end of the feeding roll, and a second mounting device comprises a second vertically movable, preferably pivotable housing adapted to mount or suspend a second end of the feeding roll opposite to the first end of the feeding roll. By providing the first and second housings pivotable independently of each other and an intermediate axle, the feeding roll adapts to a non-uniform stack of papers, improving the reliability of the feeding.

Abstract: An image forming apparatus includes an apparatus main body, a sheet feed cassette, and a conveyance unit. The sheet feed cassette is attachably/detachably supported by the apparatus main body. The sheet feed cassette includes pressing portions provided on both sides thereof in the sheet width direction. The movable guide includes pressed portions provided on both sides thereof in the sheet width direction. By the pressed portions abutting on the pressing portions, the movable guide is pushed up by the sheet feed cassette, and the movable guide is positioned with respect to the fixed guide. The pressing portion provided on another side of the sheet feed cassette in the sheet width direction includes an adjusting mechanism that adjusts pressing force against the pressed portion provided on another side of the movable guide in the sheet width direction to enable adjustment of pressure abutment force between the conveyance rollers.

Abstract: A sheet feeding apparatus capable of lifting a feed roller at low cost without increasing size thereof and an image forming apparatus including the same are proposed. A sheet fed from a rotary feed member is conveyed by a rotary conveyance member while being separated one by one by a rotary separation member being in contact with the rotary conveyance member. The rotary feed member is moved between a standby position above the sheet and an abutment position where the rotary feed member abuts with the sheet by a lifting portion. The lifting portion includes an actuation member moving a holding portion up and down and a drive member driving the actuation member. The actuation member is disposed on a second shaft, which is configured to rotate the rotary separation member.

Abstract: In a sheet feeding device, a document mounting board includes a first member that includes a first mounting surface and is located on the feed mechanism side in the feeding direction of the documents in the feed mechanism, the first mounting surface being inclined to a lower side toward the feed mechanism, and a second member that includes a second mounting surface on which the documents are mounted and is disposed on a side opposite to the side of the first member on which the feed mechanism is located, and the second member is connected to the first member to be rotatable about a second turning shaft and turns about the second turning shaft depending on the weight of the documents detected by the weight sensor to change an angle with respect to the first member.

Abstract: An object is to provide an image forming apparatus capable of switching, with a simple configuration, the positional relation between a supporting member and a feeding member and the positional relation between a developing member and a photosensitive member. A separation cam 100 rotated by the driving force of a motor M and a slider 101 moving in accordance with the rotation of the separation cam 100 are configured to switch the positional relation between a lifting plate 13 and a feeding roller 3 and the positional relation between a developing roller 103b and a photosensitive drum 8.

Abstract: The present disclosure provides a paper stop structure, a paper feed unit, and an image forming apparatus. The paper stop structure includes a movement stopper and a paper stopper both swingably configured in a paper feed path, and a separation structure to separate the movement stopper and the paper stopper. In paper stopping state, the paper stopper is pushed by an external force to swing until contacting the movement stopper, and blocks paper sheets from entering the paper feed path. In non-paper stopping state, the paper stopper is pushed by an external force to swing and separates from the movement stopper. Accordingly, various functions of paper feeding, paper stopping, and paper detecting may be achieved, and large capacity paper feeding can also be achieved to improve product operating efficiency and to effectively prevent paper mis-feed and paper jam during the image forming apparatus operation.

Abstract: An image recording device having a recording unit to record an image on a sheet is provided. The image recording unit includes a feed guide defining a first conveying path; an arm disposed between the recording unit and the tray, the arm having a feed roller rotatably disposed at a free end and configured to feed the sheet in the tray to the first conveying path. The arm pivots between a first arm position, and a second arm position. The return guide pivots between a first return guide position, and a second return guide position. A space occupied by the return guide in the first return guide position overlaps a space occupied by the arm in the second arm position. The return guide is in the second return guide position when the arm is in the second arm position which is retracted from an insertion space occupied by the tray.

Abstract: A sheet conveyance apparatus is equipped with a stacking portion on which sheets are stacked, a rotator conveying a sheet by rotating in a contact state with the sheet stacked on the stacking portion, a separating member pressing the rotator and separating the sheets one by one at a contact portion where the rotator and the separating member contact each other, and a holder holding the separating member. A guide portion is rotatably provided with the holder and capable of guiding a front end of the sheet to the contact portion, and a regulating portion regulates the guide portion from rotating in a direction approximating the rotator in a state where the guide portion contacts against the regulating portion. The guide portion can be rotated in a direction separating from the rotator in a state where the separating member presses the rotator.

Abstract: An image forming apparatus which is able to stably perform paper feeding without double feeding the printing medium, and is also able to prevent a quality of the printing medium from being damaged is provided. The image forming apparatus includes a pick-up roller configured to pick up the printing medium, and a driving source configured to transmit a driving force to the pick-up roller, wherein the pick-up roller is provided to be raised and then to be returned to its original location when picking up the printing medium.

Abstract: A sheet feeding apparatus includes a sheet receiving plate configured to receive a sheet and pivot in an up-down direction; a feed roller configured to pivot between a contact position where the feed roller contacts the sheet on the sheet receiving plate and a withdrawal position where the feed roller withdraws from the sheet; an urging member configured to urge the sheet receiving plate upward; an abutting portion configured to, when the sheet receiving plate pivots upward, abut the sheet and stop the sheet receiving plate; a moving member configured to, after the sheet abuts the abutting portion, move the sheet receiving plate to a sheet feed position; and a feed roller pivoting mechanism configured to, when the sheet receiving plate pivots upward, withdraw the feed roller to the withdrawal position and to, after the sheet contacts the abutting portion, move the feed roller to the sheet receiving plate.

Abstract: A reading apparatus includes a reading unit configured to read a document, a feeding tray on which the document to be read by the reading unit is stacked, a feeding roller that feeds the document from the feeding tray to a position where the document is read by the reading unit, a feeding pressure plate that presses the document against the feeding roller so that the document is pinched between the feeding roller and the feeding pressure plate, and a discharge roller that discharges the document read by the reading unit to underneath the feeding pressure plate, wherein a position of the discharge roller moves depending on a number of documents pinched between the feeding roller and the feeding pressure plate.

Abstract: When it is judged that a predetermined operation for eliminating a cause for stopping a job is being executed, a following job is restricted from being executed prior to a stopped job.

Abstract: Interlocked with an operation in which a feeding cassette is drawn out from a main body of a device, a restriction rib moves to a permissive position from a restrictive position, and interlocked with an operation in which the feeding cassette is inserted into the main body of the device, the restriction rib moves to the restrictive position from the permissive position.

Abstract: An image forming apparatus includes a storing-device body that is drawable from an image-forming-apparatus body, a supporting member attached to the storing-device body and that supports a stack of recording media from below, a feeding member that feeds a top one of the recording media on the supporting member into the image-forming-apparatus body, a moving mechanism that moves the supporting member such that the top one of the recording media on the supporting member comes into contact with the feeding member, a connecting mechanism that connects the moving mechanism to a drive source in conjunction with attaching of the storing-device body to the image-forming-apparatus body, an image forming section that forms an image on the recording medium fed by the feeding member, and a disabling mechanism that disables connection between the drive source and the moving mechanism in conjunction with pushing of the storing-device body into the image-forming-apparatus body.

Abstract: A gear engagement mechanism of a life device includes a lifting member interlocking with a lifting tray to linearly move in a vertical direction, and a gear train having a pinion engaged with the rack to transmit a rotary motion to the rack and transmitting the rotation torque of a lift motor M to the pinion. When the lifting member has over-run an upper limit stop position and a lower limit stop position, engagement of the pinion and the rack is released.