179 results about "Rolleron" patented technology

The invention belongs to the technical field of building assistive devices, and particularly relates to a large-span steel structure truss high-altitude roller sliding device which comprises a supporting mechanism, a clamping mechanism, a moving mechanism and an auxiliary mechanism. The supporting mechanism comprises a cross beam, the cross section of the cross beam is of an I-shaped structure, and beam grooves are symmetrically formed in the two sides of the cross beam in the length direction of the cross beam. And the clamping mechanism is mounted above the cross beam and is used for fixing and dismounting the truss. A spline rod is in sliding fit with a spline sleeve, the distance between a movable frame and a fixed frame is adjusted in combination with a second self-locking threaded rod, and cross beams with different thicknesses are adapted; in the auxiliary moving assembly, a second double-end self-locking screw drives a sliding block, a linkage movable rod and an auxiliary wheel to adjust the distance, beam grooves with different depths are adapted, the auxiliary wheel forms track constraint, and the auxiliary moving assembly can be rapidly installed on different supporting mechanisms within a certain range.

The utility model relates to the technical field of fluent strips, and discloses a fluent strip with an anti-abrasion structure, which comprises a support, a rolling shaft is arranged in the support, the side wall of the rolling shaft is fixedly connected with an idler wheel, two ends of the support are fixedly connected with baffles, and the baffles are fixedly connected with the support. A lubricating assembly is arranged on the inner wall of the support. According to the fluency strip with the anti-abrasion structure, lubricating oil is brought to the whole transmission part along with the movement of the pin rollers, independent oil injection or manual oil adding is not needed, the maintenance frequency and the labor cost are reduced, the slope structure of the outer ring guides external sundries not to enter a bearing area but slide to the outside of a lubricating assembly, chippings entering a bearing are reduced, and the service life of the bearing is prolonged. The lubricating oil quantity is automatically controlled, oil bubbles or over-lubrication is prevented, the oil discharge hole automatically releases oil, the oil updating function is achieved, the lubricating oil is kept clean, the lubricating reliability is improved, and the phenomena of abrasive particle abrasion, corrosion, emulsification and the like are reduced.

The utility model discloses an ironing head moving mechanism of a packing machine, which comprises a supporting mechanism, a pressing mechanism and a moving mechanism, the driving mechanism is connected with the supporting mechanism; the sliding mechanism is connected with the driving mechanism; the ironing head is arranged on the sliding mechanism; the driving mechanism comprises a driving motor connected with the supporting mechanism; the driving wheel is connected with a driving shaft of the driving motor; the rolling shaft is arranged at the non-circle-center position of the end face of the driving wheel; the sliding mechanism comprises a sliding seat connected with the rolling shaft; the sliding groove is formed in the sliding seat, and the rolling shaft is located in the sliding groove; the linear bearing is arranged in the moving direction of the ironing head, and the sliding base is connected to the supporting mechanism in a sliding mode through the linear bearing. In the utility model, the driving motor drives the driving wheel to rotate, so that the rolling shaft on the end face of the driving wheel applies force to the sliding chute, the sliding seat moves on the linear bearing, the ironing head moves back and forth, the structure is simple, the failure rate is low, and the cost is low.

The utility model provides a self-adaptive roller chain tensioning device which comprises a tensioning wheel and a locating piece, the outer side wall of the tensioning wheel abuts against a roller chain, the tensioning wheel is rotationally connected to one end of a connecting rod through a rolling shaft, the other end of the connecting rod is fixedly connected with a driven wheel, and the driven wheel is arranged in the locating piece. A driving rod corresponding to the driven wheel is arranged in the positioning piece, and the driving rod is fixedly connected with the driving assembly; a tooth groove is formed in the outer wall of the driven wheel, a rack is fixedly arranged on the end face, close to the driven wheel, of the driving rod, and the rack is meshed with the tooth groove. The automatic tensioning device has the advantages that pre-tightening force is applied to the driving rod through the driving assembly, the driving rod drives the driven wheel to rotate under the condition allowed, then the tensioning wheel is made to move, the automatic tensioning function is achieved, meanwhile, one-way rotation limitation on the driven wheel is completed through the ratchets on the driven wheel and the positioning disc in the positioning piece, and the tensioning effect is improved. And the working state of the tensioning wheel is stabilized.

This invention provides an assembly device for an air pump rotor, including a pressing mechanism, a positioning mechanism, and a load-bearing locking mechanism. The positioning mechanism is used to position a first workpiece, and the pressing mechanism, located above the positioning mechanism, is used to press a second workpiece. The load-bearing locking mechanism includes a support rod, a positioning shaft, a load-bearing locking block, and a locking cylinder. The support rod can move in the opposite direction of pressing. The positioning shaft, located at the top of the support rod, is used to position an assembly part on the first workpiece. The support rod has an insertion hole perpendicular to the pressing direction. The load-bearing locking block is inserted into the insertion hole and slidably connected to it. A roller is located at the top of the insertion hole, and a locking part is provided on the load-bearing locking block. After the positioning shaft positions the assembly part on the first workpiece, the locking cylinder drives the load-bearing locking block to move, causing the locking part to abut against the outer periphery of the roller and lock the support rod. This invention achieves automatic assembly of the air pump rotor. During pressing, the load-bearing locking mechanism locks the positioning state, extending the service life of the equipment and improving the assembly quality.

The invention relates to the technical field of wind power gear box precision machining, and discloses a wind power gear box precision machining device which comprises a stand column, a main shaft system is arranged at one end of the stand column, two sets of supporting columns are arranged at one end of the stand column, positioning discs are arranged in the two sets of supporting columns, and bases are arranged at the output ends of the positioning discs. An equal-force surrounding mechanism is arranged on one side of the top end of the base, the rolling shaft is arranged at the top end of the limiting plate, a first motor is arranged at the top end of the base, and the output end of the first motor is sleeved with an expansion mandrel mechanism. Initial clamping stress is eliminated through three-point kinematics supporting, the double-hole expansion mandrel establishes a unique main axis with a bearing hole as the benchmark, coaxiality is guaranteed from the source, clamping force is evenly distributed around the benchmark axis through surrounding pressure-equalizing clamping, thin-wall deformation is completely eradicated, the benchmark penetrates through the whole process through overall rotation turning, re-alignment is not needed after turning, and the machining precision is improved. And through the synergistic effect of the four innovations, the machining precision and efficiency are remarkably improved.

A conveyor is disclosed. The conveyor comprises a roller shaft coupled to a side rail, a conveyor belt positioned around the roller shaft, and a tensioner assembly coupled to the roller shaft. The tensioner assembly is configured to adjust a tension of the conveyor belt. The tensioner assembly comprises a tensioner movably coupled to the side rail. The tensioner assembly further comprises a bracket rigidly coupled to the side rail. The tensioner assembly further comprises a spring positioned between the tensioner and the bracket. The spring is configured to compress when the tension of the conveyor belt is increased by the tensioner assembly. Further, the tensioning assembly comprises an indicator positioned parallel to the spring. The indicator is configured to indicate the tension of the conveyor belt.

This utility model relates to a guiding mechanism, belonging to the field of tunnel boring and tunnel construction equipment. The mechanism includes a guide rail and a guide seat. The guide seat is equipped with upper and lower rows of rollers, which are respectively positioned on the upper and lower sides of the guide rail to clamp it. Rolling friction is formed between each roller and the corresponding top / bottom surface of the guide rail. Side sliders are provided on the left and right inner sides of the guide seat. Each side slider is pressed by a corresponding side-clamping device mounted on the guide seat, ensuring that each side slider contacts the left and right sides of the guide rail. Through pure rolling contact between the top / bottom surfaces of the guide rail and the rollers, sliding friction at the reference surface is reduced / eliminated. The rigid positioning of the rollers combined with the lateral constraint of the nylon sliders effectively suppresses swaying and ensures the stability of the drill barrel axis. This solves the problems of durability, stability, and drill jamming caused by wear of the metal reference surface in existing technologies.

The lifting device for the shield tunneling machine comprises a base, a support is movably arranged in an inner cavity of the base, supporting plates are fixedly connected to the two sides of the upper end of the support, arc supporting faces are arranged on the upper sides of the opposite faces of the upper ends of the supporting plates, and rolling shafts are rotationally connected to the four corners of the lower end of the support through lug plates; the upper end of each lifting triangular block is an inclined face, the inclined faces are located at the lower ends of the rolling shafts, the lower ends of the lifting triangular blocks are fixedly connected with transmission displacement blocks, and transmission screws are inserted into the middles of the left and right opposite transmission displacement blocks. According to the structure provided by the embodiment of the invention, when the transmission displacement block is driven to move through forward and reverse rotation of the transmission screw rod, the transmission displacement block can stay at the position where the double-shaft motor does not work without providing other power sources after the transmission displacement block moves to the position, so that the up-and-down movement of the supporting plate is stable; and the position of the supporting plate cannot be changed due to the damage of the double-shaft motor.

The utility model provides a hinge, including casing, pivot, buffer device and first piston, the casing is equipped with the cavity, be equipped with first cam surface on the pivot, first piston is located in the cavity and can reciprocate along the cavity axial motion, first piston is equipped with first groove body to one end of pivot, one side of first groove body is equipped with second groove body with first groove body intercommunication away from the pivot, first gyro wheel is movably arranged in the first groove body, be equipped with a plurality of side -by -side and mutual contact's roll axle in second groove body, a plurality of roll axle is along the circumferential side surface arrangement of first gyro wheel, buffer device provides the resistance force and makes the circumferential side surface of first gyro wheel respectively resist in first cam surface and roll axle. The utility model discloses the pivot rotation is more smooth and the transmission is more stable.

The application discloses a conveying device for producing fluffy modified nylon filaments, and relates to the technical field of cotton filament conveying, which comprises a support, a baffle plate is fixedly installed on the top of the support, conveying rollers are arranged between the baffle plates, the conveying rollers are transmissionally connected through a conveying belt, a rotary motor is fixedly installed on the surface of the baffle plate, the output end of the rotary motor penetrates through the inner and outer walls of the baffle plate, the output end of the rotary motor is fixedly installed on the surface of the conveying roller, an outer shell is fixedly installed on the top of the baffle plate, a feeding port is formed in the top of the outer shell, a feeding pipe is fixedly installed on the top of the outer shell, a bottom plate is fixedly installed on the bottom of the outer shell, the rotation of the flow guide plate drives the rotation of the rotating shaft, and the rotation of the rotating shaft drives the rotation of the roller shaft, so that when the inside of the outer shell is filled with too many bundled filaments, continuous feeding of the feeding pipe can prevent the device from being overloaded and unable to normally complete conveying.

The invention relates to the technical field of packaging box processing, and provides a cutting machine for packaging box production, which comprises a supporting mechanism, the supporting mechanism comprises a base, a cutting seat and a supporting seat, and the top of the cutting seat is provided with a cutting groove; and the cutting mechanism comprises a fixing frame installed at the top of the cutting base, and a second telescopic rod is installed at the top of the fixing frame. According to the device, a first pressing roller, a first pressing cylinder, a second pressing roller and a second pressing cylinder on the outer surfaces of a first rolling shaft and a second rolling shaft extrude raw materials to generate friction force, it is guaranteed that the raw materials can accurately move in the conveying direction along with rotation of the first rolling shaft and the second rolling shaft, a driving motor is arranged to drive a worm to rotate, a fourth gear and the second rolling shaft are directly driven to rotate, and therefore the raw materials can be conveyed conveniently. And then a first gear and a second gear located in the transmission box are engaged with a third gear and a fourth gear correspondingly, power is transmitted to the first rolling shaft, precise rotation and stopping of the first rolling shaft and the second rolling shaft are achieved through precise rotation control precision of a driving motor, and the positioning precision of the device is effectively improved.

The utility model provides a kind of inflatable roller, comprising: roller main body, roller main body has circumferential side wall, first end cap and second end cap connected to the both ends of circumferential side wall, and circumferential side wall, first end cap and second end cap are formed with inflatable cavity around.Inflatable design enables roller to deflate and fold when not in use, making it easy to carry and store, greatly improving the portability and practicality of the product.

The application belongs to the technical field of roller cleaning, in particular to a cold-rolling continuous annealing line roller cleaning device, which comprises a roller shaft body, a roller shaft support is installed below the roller shaft body, a roller shaft snap ring is fixedly connected to the center of the adjacent side wall of the roller shaft support, the inner walls of the two roller shaft snap rings are respectively clamped with the outer walls of the two ends of the roller shaft body, a stable connecting rod is fixedly connected to the two sides of the roller shaft support, a reciprocating screw rod is installed above one of the stable connecting rods, screw rod supports are fixedly connected to the two ends of the reciprocating screw rod through bearings. The outer wall of the roller shaft body is cleaned during operation under the blowing of high-pressure airflow. Compared with the way of scraping plate contact wall cleaning, the way of high-pressure airflow cleaning can guarantee the cleaning completeness of the airflow coverage area, thereby increasing the cleaning completeness of the outer wall of the roller shaft body and reducing the quality defects of the plate surface caused by incomplete cleaning of the outer wall of the roller shaft body.

The utility model relates to actuator technical field especially is single -action cylinder pneumatic actuator, including actuator body and the main shaft and piston rod of setting in the inside of actuator body, the main shaft is connected with piston rod drive, the both sides of actuator body are equipped with balance seat and air cylinder respectively, the one end of piston rod extends to balance seat and another end extends to air cylinder and is connected with piston piece, still include the yoke piece of sheathed on the main shaft and the roller axle of wearing in the piston rod, the roller axle follows piston rod and reciprocates along the axial movement, one side of yoke piece is equipped with the opening of transmission cooperation with roller axle, the piston rod drives yoke piece and the main shaft rotation through roller axle, when yoke piece rotates roller axle and opening present relative sliding, the utility model adopts single -action cylinder's configuration scheme, has the advantage that structure is small and economical.

The invention discloses a container ship skirting line coating shielding adhesive tape pasting tool, and belongs to the technical field of ship building. Comprising a support and a coating masking tape feeding mechanism, four universal wheels are arranged below a platform, a boss is arranged above the platform, a guide wheel mounting plate is arranged on the left side of the boss, and a guide wheel is mounted on the guide wheel mounting plate; an adhesive tape inner support and a tape pressing roller mounting plate of the coating shielding adhesive tape feeding mechanism are fixed on a boss, the axis of the adhesive tape inner support is perpendicular to the boss, a tape pressing roller mounted on a tape pressing roller shaft mounting plate is arranged on the right side of the boss, the axis of the tape pressing roller is parallel to the axis of the adhesive tape inner support, and the tape pressing roller and a guide wheel are arranged on the front side of the boss. When the skirting line coating masking tape pasting tool is used, the processes of measuring, marking and cutting the masking tape are omitted, and the accuracy and tidiness during pasting can be guaranteed through direct pasting. Particularly, the guide wheel in the support can support the pasting tool to slide along the wall, the contact area between the guide wheel and the wall is small, the wall cannot be scratched, friction force is small, and operation is labor-saving.

This utility model relates to the field of cable spool technology, and in particular to a cable spool for robots, comprising a first spool, a second spool, and a wire assembly. A fixed frame is rotatably connected to one side of the first spool. The wire assembly is disposed on one side of the first spool, with one end of the wire assembly near the fixed frame connected to the fixed frame via a mounting bracket. The wire assembly includes a reciprocating screw, a pressing roller, and a wire wheel. Through the design of the reciprocating screw, pressing roller, and wire wheel, and in conjunction with a transmission wheel, transmission rigging, drive wheel, and output motor, when the output motor drives the first spool to rotate, the drive wheel and transmission rigging drive the transmission wheel and reciprocating screw to rotate. Simultaneously, due to the limiting block provided at the bottom of the wire wheel cooperating with the mounting bracket, the reciprocating screw drives the wire wheel to reciprocate, ensuring that the cable reciprocates with the rotation of the first spool, guiding the cable to be evenly wound around the outer cylindrical surface of the spool shaft.

This utility model discloses a double-arc-supported bearing structure, including an inner ring, an outer ring, and a roller structure. The roller structure is mounted on the surface of the inner ring, and the outer ring is fitted onto the surface of the roller structure. A groove is formed on the inner wall of the outer ring, and an externally threaded rod is welded inside the groove. A retaining ring is provided inside the groove, and a hole is formed inside the retaining ring. A cavity is formed at the top of the hole, and the cavity is located inside the retaining ring. This double-arc-supported bearing structure, by mounting the roller structure on the surface of the inner ring and fitting the outer ring onto the roller structure, and simultaneously creating a groove on the inner wall of the outer ring with an externally threaded rod welded inside the groove, allows for the installation and fixation of the bearing. For disassembly, the nut can be removed, followed by the removal of the retaining ring, and then the inner ring and roller structure can be disassembled, allowing for subsequent replacement of the roller and reducing costs during use.

The invention provides a rolling shaft type pressing wheel, a walking type self-compaction moulding bed and a construction method.The rolling shaft type pressing wheel comprises two mounting plates, a plurality of connecting shafts and a plurality of rolling shafts, the two mounting plates are used for fixing a bottom plate, a first side plate and a second side plate of a foundation trench, and the bottom plate, the first side plate and the second side plate are used for forming a U-shaped ground beam pouring groove; one mounting plate is used for fixing the bottom plate and the first side plate, the other mounting plate is used for fixing the bottom plate and the second side plate, one end of the connecting shaft is connected with one mounting plate, and the other end of the connecting shaft is connected with the other mounting plate; the connecting shafts are used for being arranged in the length direction of the foundation trench and evenly connected with the two mounting plates, and the rolling shafts are sequentially and rotationally mounted between the two mounting plates, located below the connecting shafts and used for compacting the bottom of the foundation trench in a rolling mode. According to the rolling shaft type pressing wheel, compaction of the bottom of a foundation trench is achieved, and construction quality and safety are guaranteed.

The application provides an elevator compensation chain length measuring device and relates to the technical field of mechanical automation. The technical key points are that the device comprises a support frame and a length measuring sensor. Two groups of symmetrical stabilizing devices are arranged above the support frame. Each stabilizing device comprises two stabilizing rollers extending along the width direction of the support frame and a stabilizing belt. A pressing device is arranged above each stabilizing device. The pressing device comprises a pressing roller corresponding to the stabilizing roller and a pressing belt. A driving device is arranged above the pressing device to drive the pressing device to move in the vertical direction. A motor sliding table is arranged on the support frame to adjust the position of the length measuring sensor. The length measuring sensor is not affected by the smoothness of the surface of the compensation chain during the measurement. Meanwhile, the pressing device and the stabilizing device reduce the vibration and friction of the compensation chain during the length measurement, thereby reducing the possibility of error.

The utility model belongs to the field of door fences, and discloses a telescopic infant door fence which comprises at least one piece of fence cloth. The roller is mounted on one side of the fence cloth; a rolling shaft is coaxially arranged in the roller; one end of the fence cloth is fixed with the rolling shaft and then is wound on the periphery of the rolling shaft; longitudinal openings allowing the fence cloth to enter and exit are formed in the peripheral surface of the roller; the upper end of the roller is fixedly connected with a shell, and the lower end of the shell is connected with a base fixedly connected with an installation fixing face. The control part is arranged in the shell and is used for controlling the rotation and locking of the rolling shaft; the control part comprises a gear coaxially connected with the rolling shaft, a tooth-shaped structure capable of being meshed with the gear is arranged on one side of the gear, the tooth-shaped structure is meshed with the gear, locks the rolling shaft, prevents the rolling shaft from rotating, the tooth-shaped structure is separated from the gear, and the rolling shaft rotates to release or retract the fence cloth. One side of the fence cloth is fixed through the roller and the rolling shaft coaxially arranged with the roller, the fence cloth is wound on the periphery of the rolling shaft along with rotation of the rolling shaft, and recycling and releasing of the fence cloth are achieved.

The utility model discloses a feeding platform device which comprises a supporting bracket, a sundry material lower baffle plate, a loading baffle plate and a lifting mechanism, the lifting mechanism comprises a conveying belt, a motor, a speed reducer, a rack, a sugarcane hook, a driving roller, a driven roller, an inner rolling shaft, a side plate, a tensioning mechanism and an inner rolling shaft support. The lifting mechanism, the loading baffle and the sundry material lower baffle are all installed on the supporting support, and the rear end of the loading baffle is fixedly connected with a plurality of arc-shaped hooks. An inner rolling shaft bracket is fixed on the inner side of the rack, and an inner rolling shaft is arranged on the inner rolling shaft bracket; a side plate and a tensioning mechanism are fixed on the outer side of the rack; a driving roller and a driven roller are respectively arranged between the top end and the bottom end of the tensioning mechanism; the driving roller and the driven roller are covered with a conveying belt from top to bottom. And a sugarcane hook is arranged on the conveying belt. When the sugarcane conveying device is used, the motor drives the driving roller to rotate, mud and sand fall from gaps of the arc-shaped hooks, the sugarcane hooks lift sugarcanes upwards along with the conveying belt and then fall into follow-up operation machinery, and the purposes of mud and sand removal and feeding are achieved.

The utility model discloses a kind of rolling low friction deflector, belong to prestressed variable angle tensioning device technical field, solve the problem that the friction between steel strand and deflector in existing deflector is sliding friction, friction resistance is big, leading to the problem of big friction loss. It includes at least one fan-shaped steel plate, at least one layer of guiding structure is arranged on the steel plate along its radial direction, each layer of guiding structure includes multiple rollers, multiple rollers corresponding to each layer of guiding structure are distributed in the circumferential arc line of steel plate, each roller is rotatably connected with the steel plate. The rolling low friction deflector of the utility model can greatly reduce the friction resistance of prestressed tensioning, reduce engineering cost.

Fluted discs are installed on the two sides of a center shaft, variable-diameter discs are installed on the outer sides of the fluted discs through fixed disc bearings, each variable-diameter disc comprises a fixed disc, the fixed disc is provided with a plurality of fixed disc supporting arms in the radius direction, movable arms are slidably connected to the fixed disc supporting arms in a sleeving mode, and limiting rolling shafts are installed on the movable arms. The limiting rolling shaft is located in an arc-shaped limiting sliding groove formed in the disc face of the fluted disc. Arc-shaped supporting plates are installed at the top of the movable arm, a positioning connecting rod is installed between the two opposite arc-shaped supporting plates in the direction of the center shaft, arc-shaped roller plates are installed on the outer side of the positioning connecting rod, one of the adjacent edges of the adjacent arc-shaped roller plates is located below or above the other arc-shaped roller plate, and the arc-shaped roller plates and the arc-shaped roller plates jointly form the roller circumference of the winding roller. The fan-shaped roller side plates are installed on the side faces of the arc-shaped supporting plates, one sides of the adjacent fan-shaped roller side plates are located below or above the other sides of the adjacent fan-shaped roller side plates, and the fan-shaped roller side plates and the adjacent fan-shaped roller side plates jointly form the roller side face of the winding roller. Multi-size variable-diameter adjustment is achieved, the structure is stable, and adjustment and size locking are convenient.

The invention provides a saturated diving bell crown block transfer device, and relates to the technical field of saturated diving, the saturated diving bell crown block transfer device comprises a rack and a bottom frame, the bottom frame is arranged below the rack, a lifting point assembly is arranged below the bottom frame, the lifting point assembly is used for lifting a diving bell, and a winch guide wheel base is arranged at the middle end of the top of the rack; the winch guide wheel bases are used for being connected with winch slings, shaft seats are arranged at the four corners of the top of the rack, and rolling shafts are rotationally connected into the two sets of shaft seats on the same side. When the diving bell dives, the diving bell is lifted through the lifting point assembly and is lifted to the horizontal fixed rail in cooperation with a winch, the rolling shaft is driven by the driving motor to rotate, and the rail wheels run along the horizontal fixed rail and stably run to the releasing position of the lifting frame, so that the subsequent diving operation is completed; the working height of a lifting and recycling system of the diving bell is effectively reduced, and the saturated diving bell can stably run along the horizontal fixed track and is accurate and controllable.

The application discloses a high-strength anti-vibration truck hub bearing and relates to the bearing field.The hub is internally provided with an inner ring at both ends;the inner side of the inner ring is provided with an intermediate frame;the inner side of the intermediate frame is provided with a fixing sleeve;the inner side of the fixing sleeve is provided with a positioning sleeve;a plurality of roller grooves are uniformly formed in the intermediate frame;and a roller is rollingly connected in the inner part of each roller groove.When the hub is reversed in the forward gear, that is, when the truck is sliding on a slope, the straight surfaces of the top block and the bottom block are mutually clamped to block the hub from being reversed, thereby preventing the truck from sliding on the slope.When the truck is reversed, the driving mechanism of the rotating ring is linked with the gear operation, and the low gear is scraped, so that the driving mechanism drives the rotating ring to rotate, the rotating ring drives the bottom block to retract downward by means of the guide groove and the guide column, the bottom block is not in contact with the top block, and normal reversing operation is ensured.When the low forward gear is scraped, the rotating ring drives the bottom block to move upward.