An articulated cutting head and conveyor mount for sod harvesting machines. The invention provides a linkage design that can provide many benefits including: allowing the operator to see the cutting operation, enabling the high lifting of the cutting head for service and maneuvering, managing the vertical bending load of the ground reference roller, providing high transverse stiffness, maintaining the position of the conveyor relative to the cutting head. The linkage design can include fewer parts than previous designs while still being robust and durable. As such, cutting heads employing the linkage design of the present invention can produce higher quality slabs with less service and maintenance than when using current designs.

Some embodiments of a ground surface treatment system can include a flexible roller system having one or more of rollers arranged in a side-by-side position and include a flexible axle member extending through each row of rollers.

An agricultural system includes an agricultural row unit movable on a field between a first soil condition and a second soil condition, the first soil condition having a different soil hardness than the second soil condition. A down-pressure actuator applies an initial first pressure associated with the first soil condition. A soil-hardness sensing device is positioned at a distance D forward of the row unit and outputs a soil-hardness change signal when detecting a change from the first soil condition to the second soil condition. At least one memory device stores instructions that, when executed by at least one processor, cause the down-pressure actuator to change, in response to receiving the soil-hardness change signal, the initial first pressure to a different second pressure when the row unit encounters the second soil condition.

The disclosure describes, in one aspect, a system and method for controlling a rotation angle of a blade of a motor grader having a front frame operatively coupled to a rear frame at a point defining an articulation angle between the front and rear frames. The control system includes at least one sensor operatively associated with the blade, at least one sensor operatively associated with a wheel, at least one sensor operatively associated with at least one of the front frame or the rear frame, and a controller operatively coupled to the at least one sensors. The controller is adapted to determine a current position of the blade, determine a wheel steering angle, determine an articulation angle, and control the rotation angle of the blade based in part on the wheel steering angle and the articulation angle.

A coulter assembly for an agricultural implement. The coulter assembly includes a support structure and a disc blade rotatably mounted to the support structure. The coulter assembly also includes a spring assembly coupled to the support structure and configured to urge the disc blade into soil. The spring assembly includes a variable rate spring.

A cleanup device having a first board having a first edge, a second board having a first edge, a first hinge attached to the first edge of the first board and the first edge of the second board, an aperture defined by a portion of the first edge of the first board and a portion of the first edge of the second board, a first plate slidably attached to the first board, wherein the first plate is movable from a first, open position where the aperture is open to a second, closed position where the first plate extends over at least a portion of the aperture, and wherein a top surface of the first board is movable towards a top surface of the second board to form a V-shaped surface for directing dirt or soil off of the first board and the second board.

An agricultural machine (101; 201; 301) comprising two mainly parallel, in the direction of travel, cross-running disc implement rows (102a, 102c; 202a, 202b; 304a, 304b), wherein the orientation of the disc implements (102b, 102d; 203a, 203b; 302a, 302b) contained in the mentioned disc implement rows is arranged so that the fore row (102a; 202a; 304a) has disc implements that are mounted on a frame beam (110; 211; 303) and that are angled outwards and backwards towards the sides of the machine and in a dividing line mainly parallel to the direction of travel of the machine form a first point of change (208a, 304c), and the rear row (102c, 202b; 304b) has disc implements (102d; 203b; 302b) that are mounted on a frame beam (110; 211; 303) and that are angled inwards and backwards from the sides of the machine and in the dividing line form a second point of change (208b, 304a), wherein the fore row is adapted to throw soil from the first point of change outwards towards the sides of the machine and the other row is adapted to throw soil from the sides of the machine inwards towards the second point of change. The dividing line with the first point of change (208a, 304c), and with the second point of change (208b, 304) is arranged at a predetermined distance from the centre line of the machine (101; 201; 301) across the direction of travel.

A trailer includes a chassis having a hitch, an axle having a pair of tractive elements rotatably coupled to the chassis, an actuator coupled to the chassis and positioned to steer the pair of tractive elements, and a processing circuit. The processing circuit has an input for receiving a transmission gear of a tractor vehicle and a variable output for engaging the actuator. The processing circuit is configured to control the steering of the pair of tractive elements according to a control strategy that varies based on the transmission gear of the tractor vehicle.

A swing control apparatus and a swing control method for a construction machine are provided. The swing control apparatus includes a start position estimation unit, a stop target position calculation unit, and a swing motor position control unit. Even if an operator releases a lever or commands a stop at different times, an upper swing structure of the construction machine (for example, excavator) can be stopped within a predetermined range, and thus the inconvenience caused by an additional driving operation, which is required as the stop position differs according to the time point where the stop command starts, can be solved.

A turf cutter device, an infill extractor/collector device, and a turf wind-up device are used to facilitate the cost-effective removal of an infilled synthetic turf and the subsequent installation of a new turf at the same site, with minimal subsurface disruption. An infill extractor/collector device mounted on a motorized vehicle moves a relatively narrow strip of filled artificial turf from the surface, in front of the vehicle, and directs the strip to an infill removal station. The infill removal station inverts the strip and redirects the strip back toward the front of the vehicle, after agitating the strip to extract the infill. After redirecting the strip toward the front of the vehicle, the vehicle drives over the unfilled strip. Meanwhile, the extractor/collector device moves the extracted infill rearwardly to a bag located in a trailer. The turf cutter device is used prior to infill extraction, while the turf wind up device may be used before or after infill extraction, depending on whether infill extraction takes place at the field or at a remote site, respectively.

An apparatus for servicing roadways includes a frame configured to be secured to a prime mover. The apparatus further includes a grinding drum rotatably supported upon the frame. The apparatus still further includes a driving system supported upon the frame and configured to rotationally drive the grinding drum.

A system for determining a cut location at a work surface includes a position sensor and a controller. The controller stores a desired operating parameter and a final design plane of the work surface and determines an actual profile of the work surface. The controller determines a plurality of target profiles corresponding to different cut locations. The target profiles are based at least in part upon the cut location, a loading profile, slot parameters, and the actual profile of the work surface. The controller further determines an optimized target profile relative to the desired operating parameter and the optimized target profile defines an optimized cut location.

The invention concerns a drill bit, intended to be used with a down-the-hole drill and comprising a drill head (2) with a front surface provided with drill pins (3) and a shaft (4), whereby the shaft is narrower than the drill head and intended to be inserted in a manner that allows axial sliding into the end of a drill chuck that is a component of a down-the-hole drill and which shaft has a rear end part (6) that is somewhat thickened with a plane striking surface (7) against which a hammer piston (8) that is a component of the down-the-hole hammer drill is arranged to impact, that the drill head when viewed along its axial direction has a cylinder-shaped forward part (20) provided with cuttings channels (22), a rear cylinder-shaped part (21) that is located for the reception of drill cuttings at the same level or somewhat below the bottom (25) of the cuttings channels, whereby the diameter (D1) of the forward part is greater than the diameter (D2) of the rear part. In a drill bit that has high performance and a long useful life, and that is furthermore well-suited to be used for directed drilling, the cylinder-shaped forward part (20) of the drill head (2) has an axial length (L3) from the main plane of the front surface to a shoulder plane (26) located between the drill head (2) and the shaft (4) that is greater than the axial length (L4) of the cylinder-shaped rear part (21) of the drill head.

A brake control system and method for motor vehicles is provided with an electronic control unit, by which, when the motor vehicle is stationary, a parking brake function can be activated manually or automatically. Its deactivation occurs upon reaching a predefined release condition. In the presence of a release condition the brake pressure, which was built up for the parking brake function, is released in a time offset manner at least in relation to the axles of the vehicle by way of the control unit.

The present invention extends to a stacking mechanism having electrical actuators for stacking slabs of sod on a sod harvesting machine. The electrical actuators allow the stacking head to be driven in three axes. The stacking mechanism also includes position feedback sensors for reporting the position of the stacking head to enable precision when operating the stacking head at a fast rate. The stacking mechanism of the present invention also provides temporary pallet support wings to enable the continued stacking of slabs of sod on one pallet even while another pallet is being dropped from the sod harvesting machine.

A hitch on a vehicle is raised and lowered by a hydraulic actuator controlled by an electrically operated valve. A control system receives a command that indicates a designated velocity and uses the command to operate the valve. Based on a reference external force exerted on the hitch, the control system is configured with relationships for converting a plurality of command values to corresponding electric current levels for operating the valve. The control system compensates for effects due to differences between the actual force acting on the hitch and the reference external force. Velocity feedback adjusts the electric current level applied to the valve. The passive load force control provides a predictor of the hitch load force to eliminate overshoot/undershoot of hitch motion. During hitch motion, the velocity feedback also compensates for effects due to load and hitch geometry changes that occur.

An apparatus for extracting and collecting particulate infill from an infilled artificial turf field. A vehicle has a first forward end and a second rearward end. An infill extractor is located at the first end of the vehicle and adapted to extract infill from a strip of infilled athletic turf. Extracted infill falls into a bottom section of the infill extractor. An infill mover is secured to the vehicle and adapted to move the extracted infill from the bottom section of the infill extractor toward the second end of the vehicle. An infill collector is connected to the second end of the vehicle and operable to cooperate with the infill mover to collect the moved infill. The infill collector includes a frame that is laterally movable relative to the vehicle from an operative “in use” position to a stowed position.

A control system for a machine is disclosed. The system includes a ripper sensor associated with a ripper of the machine configured to generate a signal indicative of a position of the ripper. The system includes a steering command sensor associated with a steering control module of the machine. The steering command sensor is configured to generate a signal indicative of a steering command of the machine. The system further includes a controller configured to receive the signals indicative of the position of the ripper and the steering command of the machine. The controller is configured to execute an action based on the engaged state of the ripper and the steering command of the machine.

Disclosed is a coupler comprising a first structure, a first shaft rotatably supported by the first structure, a second structure supporting the first structure, and a moving device configured to move the first structure relative to the second structure.

According to embodiments of the invention, a TFT array substrate, a manufacturing method of the TFT array substrate and a display device are provided. The method comprises: depositing a metal film on a substrate, and forming a gate electrode and a gate line; forming a gate insulating layer and a passivation layer on the substrate; depositing a transparent conductive layer, a first source/drain metal layer and a first ohmic contact layer, and forming a drain electrode, a pixel electrode, a data line, and a first ohmic contact layer pattern provided on the drain electrode; and depositing a semiconductor layer, a second ohmic contact layer and a second source/drain metal layer, and forming a source electrode, a second ohmic contact layer pattern provided below the source electrode, and a semiconductor channel between the source electrode and the drain electrode.

An organic light emitting display device includes a light shield layer formed on a substrate and a buffer layer formed on an entire surface of the substrate, an oxide semiconductor layer and first electrode formed on the buffer layer, a gate insulation film and gate electrode formed on the oxide semiconductor layer while being deposited to expose both edges of the oxide semiconductor layer, an interlayer insulation film formed to expose both the exposed edges of the oxide semiconductor layer and the first electrode, source and drain electrodes connected with one edge and the other edge of the oxide semiconductor layer, respectively, and a protective film formed to cover the source and drain electrodes while exposing a region of the first electrode so as to define a luminescent region and a non-luminescent region.

An organic light emitting diode (OLED) display a includes: a substrate; an organic light emitting element on the substrate and including a first electrode, a light emission layer, and a second electrode; and an encapsulation layer on the substrate while covering the organic light emitting element. The encapsulation layer includes an organic layer and an inorganic layer. A mixed area, where organic materials forming the organic layer and inorganic materials forming the inorganic layer co-exist along a plane direction of the encapsulation layer, is formed at the boundary between the organic layer and the inorganic layer.

The present invention relates to a film for flip chip type semiconductor back surface to be formed on a back surface of a semiconductor element flip chip-connected to an adherend, the film for flip chip type semiconductor back surface containing an inorganic filler in an amount within a range of 70% by weight to 95% by weight based on the whole of the film for flip chip type semiconductor back surface.

There is provided a substrate for light-emitting element, including a mounting surface on which a light-emitting element is to be mounted, the mounting surface being one of two opposed main surfaces of the substrate. The substrate of the present invention is provided with a protection element for the light-emitting element, the protection element comprising a voltage-dependent resistive layer embedded in a body of the substrate, and comprising a first electrode and a second electrode each of which is in connection with the voltage-dependent resistive layer wherein the light-emitting element is to be mounted such that it is positioned in an overlapping relation with the voltage-dependent resistive layer.

An object is to manufacture a semiconductor device with high reliability by providing the semiconductor device including an oxide semiconductor with stable electric characteristics. In a transistor including an oxide semiconductor layer, a gallium oxide film is used for a gate insulating layer and made in contact with an oxide semiconductor layer. Further, gallium oxide films are provided so as to sandwich the oxide semiconductor layer, whereby reliability is increased. Furthermore, the gate insulating layer may have a stacked structure of a gallium oxide film and a hafnium oxide film.

A semiconductor device includes wiring layers formed over a semiconductor wafer, a via-layer between the wiring layers, conductive films in the wiring layers, and a via-plug in the via-layer connecting the conductive films of the wiring layers above and below, a scribe region at an outer periphery of a chip region along an edge of the semiconductor substrate and including a pad region in the vicinity of the edge, the pad region overlapping the conductive films of the plurality of wiring layers in the plan view, the plurality of wiring layers including first second wiring layers, the conductive film of the first wiring layer includes a first conductive pattern formed over an entire surface of said pad region in a plan view, and the conductive film of the second wiring layer includes a second conductive pattern formed in a part of the pad region in a plan view.

A method and a semiconductor device for incorporating defect mitigation structures are provided. The semiconductor device comprises a substrate, a defect mitigation structure comprising a combination of layers of doped or undoped group IV alloys and metal or non-metal nitrides disposed over the substrate, and a device active layer disposed over the defect mitigation structure. The defect mitigation structure is fabricated by depositing one or more defect mitigation layers comprising a substrate nucleation layer disposed over the substrate, a substrate intermediate layer disposed over the substrate nucleation layer, a substrate top layer disposed over the substrate intermediate layer, a device nucleation layer disposed over the substrate top layer, a device intermediate layer disposed over the device nucleation layer, and a device top layer disposed over the device intermediate layer. The substrate intermediate layer and the device intermediate layer comprise a distribution in their compositions along a thickness coordinate.

A display device comprising TFT elements having satisfactory characteristics and being easy to assemble. In the display device, a pixel emitting red light comprises a red color filter. The red color filter forms a light shielding film for the TFT elements in a driver circuit portion or in a pixel portion.

Provided are three-dimensional nonvolatile memory devices and methods of fabricating the same. The memory devices include semiconductor pillars penetrating interlayer insulating layers and conductive layers alternately stacked on a substrate and electrically connected to the substrate and floating gates selectively interposed between the semiconductor pillars and the conductive layers. The floating gates are formed in recesses in the conductive layers.

An electronic device includes a silicon carbide layer including an n-type drift region therein, a contact forming a junction, such as a Schottky junction, with the drift region, and a p-type junction barrier region on the silicon carbide layer. The p-type junction barrier region includes a p-type polysilicon region forming a P-N heterojunction with the drift region, and the p-type junction barrier region is electrically connected to the contact. Related methods are also disclosed.

An object is to provide a semiconductor device including an oxide semiconductor film, which has stable electrical characteristics and high reliability. A stack of first and second material films is formed by forming the first material film (a film having a hexagonal crystal structure) having a thickness of 1 nm to 10 nm over an insulating surface and forming the second material film having a hexagonal crystal structure (a crystalline oxide semiconductor film) using the first material film as a nucleus. As the first material film, a material film having a wurtzite crystal structure (e.g., gallium nitride or aluminum nitride) or a material film having a corundum crystal structure (α-Al2O3, α-Ga2O3, In2O3, Ti2O3, V2O3, Cr2O3, or α-Fe2O3) is used.

A semiconductor device, includes a semiconductor substrate, a first interconnect layer formed over the semiconductor substrate, a gate electrode formed in the first interconnect layer, a gate insulating film formed over the gate electrode, a second interconnect layer formed over the gate insulating film, an oxide semiconductor layer formed in the second interconnect layer, and a via formed in the second interconnect layer and connected to the oxide semiconductor layer. The gate electrode, the gate insulating film and the oxide semiconductor layer overlap in a plan view.

Semiconductor devices including a stressor in a recess and methods of forming the semiconductor devices are provided. The methods may include forming a trench in an active region and the trench may include a notched portion of the active region. The methods may also include forming an embedded stressor in the trench. The embedded stressor may include a lower semiconductor layer and an upper semiconductor layer, which has a width narrower than a width of the lower semiconductor layer. A side of the upper semiconductor layer may not be aligned with a side of the lower semiconductor layer and an uppermost surface of the upper semiconductor layer may be higher than an uppermost surface of the active region.

It is an object to manufacture a highly reliable semiconductor device including a thin film transistor whose electric characteristics are stable. An insulating layer which covers an oxide semiconductor layer of the thin film transistor contains a boron element or an aluminum element. The insulating layer containing a boron element or an aluminum element is formed by a sputtering method using a silicon target or a silicon oxide target containing a boron element or an aluminum element. Alternatively, an insulating layer containing an antimony (Sb) element or a phosphorus (P) element instead of a boron element covers the oxide semiconductor layer of the thin film transistor.

A semiconductor device which includes a thin film transistor having an oxide semiconductor layer and excellent electrical characteristics is provided. Further, a method for manufacturing a semiconductor device in which plural kinds of thin film transistors of different structures are formed over one substrate to form plural kinds of circuits and in which the number of steps is not greatly increased is provided. After a metal thin film is formed over an insulating surface, an oxide semiconductor layer is formed thereover. Then, oxidation treatment such as heat treatment is performed to oxidize the metal thin film partly or entirely. Further, structures of thin film transistors are different between a circuit in which emphasis is placed on the speed of operation, such as a logic circuit, and a matrix circuit.

A semiconductor film having an impurity region to which at least an n-type or p-type impurity is added and a wiring are provided. The wiring includes a diffusion prevention film containing a conductive metal oxide, and a low resistance conductive film over the diffusion prevention film. In a contact portion between the wiring and the semiconductor film, the diffusion prevention film and the impurity region are in contact with each other. The diffusion prevention film is framed in such a manner that a conductive film is exposed to plasma generated from a mixed gas of an oxidizing gas and a halogen-based gas to form an oxide of a metal material contained in the conductive film, the conductive film in which the oxide of the metal material is formed is exposed to an atmosphere containing water to be fluidized, and the fluidized conductive film is solidified.

A solder bump structure for a ball grid array (BGA) includes at least one under bump metal (UBM) layer and a solder bump formed over the at least one UBM layer. The solder bump has a bump width and a bump height and the ratio of the bump height over the bump width is less than 1.

Some embodiments include transistors having a channel region under a gate, having a source/drain region laterally spaced from the channel region by an active region, and having one or more dielectric features extending through the active region in a configuration which precludes any straight-line lateral conductive path from the channel region to the source/drain region. The dielectric features may be spaced-apart islands in some configurations. The dielectric features may be multi-branched interlocking structures in some configurations.

A microelectronic assembly includes a first component with first conductive elements; a second component with second conductive elements; a bond metal; and an underfill layer. The posts have a height above the respective surface from which the posts project. A bond metal can be disposed between respective pairs of conductive elements, each pair including at least one of the posts and at least one of the first or second conductive elements confronting the at least one post. The bond metal can contact edges of the posts along at least one half the height of the posts. An underfill layer contacts and bonds the first and second surfaces of the first and second components. A residue of the underfill layer may be present at at least one interfacial surfaces between at least some of the posts and the bond metal or may be present within the bond metal.

To provide a semiconductor device which has transistor characteristics with little variation and includes an oxide semiconductor. The semiconductor device includes an insulating film over a conductive film and an oxide semiconductor film over the insulating film. The oxide semiconductor film includes a first oxide semiconductor layer, a second oxide semiconductor layer over the first oxide semiconductor layer, and a third oxide semiconductor layer over the second oxide semiconductor layer. The energy level of a bottom of a conduction band of the second oxide semiconductor layer is lower than those of the first and third oxide semiconductor layers. An end portion of the second oxide semiconductor layer is positioned on an inner side than an end portion of the first oxide semiconductor layer.

It is an object to provide a highly reliable semiconductor device with good electrical characteristics and a display device including the semiconductor device as a switching element. In a transistor including an oxide semiconductor layer, a needle crystal group provided on at least one surface side of the oxide semiconductor layer grows in a c-axis direction perpendicular to the surface and includes an a-b plane parallel to the surface, and a portion except for the needle crystal group is an amorphous region or a region in which amorphousness and microcrystals are mixed. Accordingly, a highly reliable semiconductor device with good electrical characteristics can be formed.

A low resistivity interface material is provided between a self-aligned vertical heater element and a contact region of a selection device. A phase change chalcogenide material is deposited directly on the vertical heater element. In an embodiment, the vertical heater element in L-shaped, having a curved vertical wall along the wordline direction and a horizontal base. In an embodiment, the low resistivity interface material is deposited into a trench with a negative profile using a PVD technique. An upper surface of the low resistivity interface material may have a tapered bird-beak extension.

An amorphous oxide thin film containing amorphous oxide is exposed to an oxygen plasma generated by exciting an oxygen-containing gas in high frequency. The oxygen plasma is preferably generated under the condition that applied frequency is 1 kHz or more and 300 MHz or less and pressure is 5 Pa or more. The amorphous oxide thin film is preferably exposed by a sputtering method, ion-plating method, vacuum deposition method, sol-gel method or fine particle application method.

An embodiment of the present invention provides a TFT array substrate including: a base substrate (1) and thin film transistors. The thin film transistor includes a gate electrode (2), a semiconductor layer (5), a semiconductor protective layer, a source electrode (8) and a drain electrode (9). The semiconductor protective layer is disposed adjacent to the semiconductor layer (5) and includes a composite lamination structure, which includes a protective layer formed of an insulating material capable of preventing de-oxygen of the semiconductor layer (5) and an insulating layer formed of an insulating material to be etched more easily.

An object is to manufacture and provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which a semiconductor layer including a channel formation region serves as an oxide semiconductor film, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed after an oxide insulating film serving as a protective film is formed in contact with an oxide semiconductor layer. Then, the impurities such as moisture, which exist not only in a source electrode layer, in a drain electrode layer, in a gate insulating layer, and in the oxide semiconductor layer but also at interfaces between the oxide semiconductor film and upper and lower films which are in contact with the oxide semiconductor layer, are reduced.

Provided is a novel coated phosphor capable of effectively suppressing the adverse effects of hydrogen sulfide gas generated by the reaction between a sulfur-containing phosphor and moisture in the air. Provided is a sulfur-containing phosphor having a configuration in which ZnO compound containing Zn and O is present on the surface of a sulfur-containing phosphor having a host material which includes sulfur.

A transistor device includes a compound semiconductor body having a first surface and a two-dimensional charge carrier gas disposed below the first surface in the compound semiconductor body. The transistor device further includes a source in contact with the two-dimensional charge carrier gas and a drain spaced apart from the source and in contact with the two-dimensional charge carrier gas. A first passivation layer is in contact with the first surface of the compound semiconductor body, and a second passivation layer is disposed on the first passivation layer. The second passivation layer has a different etch rate selectivity than the first passivation layer. A gate extends through the second passivation layer into the first passivation layer.

Blast absorbing structures and system for use in absorbing blast forces exerted on a floor of a personnel cabin of a vehicle, are disclosed. The blast absorbing flexing structure comprises a bottom section forming a floor of the cabin, a first side section and opposing second side section, each side section extending from the bottom section and including a plurality of steps along a length of the second side section. The steps flex in response to a blast force. In another embodiment, the blast absorbing expanding structure comprises a force abatement device forming a floor of the cabin, a cover plate having a plurality of slots arranged around a perimeter of the plate. The cover plate is movable between a neutral position and a blast force position to diminish the blast forces prior to the blast forces to reaching an occupant of the cabin.

A device for use in a vehicle steering system, said device comprising at least one actuator affixed to a wheel linkage of at least one wheel of said vehicle steering system. The actuator comprises a rotation assembly engagable with a first wheel linkage segment, an electric motor for actuating movement of the rotation assembly via a gear box and one or more sensors integrally contained in the actuator for sensing one or more parameters selected from the group consisting of force, speed, turns and rotation. Rotation of the rotation assembly actuates linear movement of said first wheel linkage segment into and out of said actuator to thereby adjust one or more wheel parameters of said at least one wheel, and wherein said one or more sensors provide real time data to an actuator control unit integral to said actuator to self-adjust rotational parameters of said rotation assembly.

A four-wheel independent suspension system for an electric wheelchair includes a chassis, two front wheels each fixed to a front rod respectively, and two rear wheels each fixed to a rear rod respectively. The chassis includes a rail extending in a width direction of the chassis, each of the front and rear rods has one end connected to a square first connecting sleeve, in the first connecting sleeve is disposed a first shock absorber which includes a rectangular outer pipe, and a rectangular inner pipe disposed in and rotated degrees with respect to the outer pipe, the edges of the inner pipe are abutted against the inner surface of the outer pipe, between each of the edges of the inner pipe and the inner space of the outer pipe is disposed an elastic rubber, the inner pipe of each of the first shock absorbers is sleeved on the rail.