A kind of load transport vehicleTechnical field
The invention belongs to transporting heavy things equipment technical fields, are related to a kind of load transport vehicle, in particular to a kind of weight fortuneDefeated cart, the weight refers to that length or volume are larger, and heavier weight, such as can be the metal cylinders such as oxygen cylinder.
Background technique
The assembling processing of steel tower be unable to do without the welding of angle steel, and welding technique will use some protection gas, metal cylinderIt as the major storage device of protection gas, just transports, but metal cylinder weight is larger, carries because welding the change in place unavoidablyWant two even three people that could complete.
Many industrial and mining enterprises, which pass through, at present carries metal cylinder frequently with cart, and it is following that these carts usually require manpower completionTwo basic operations:
The first, cart is pushed into metal cylinder set-down location, then metal cylinder is removed to cart；
The second, cart is rotated, cart is kept to balance and cart is pushed to advance.
Although metal cylinder is transported essentially by cart, the case where metal cylinder being moved to avoid most people's power,The two basic operation processes also need to move metal cylinder, and also need additional mention other than pushing cart to advanceFor maintaining the power of cart balance, thus it is on the whole still time-consuming and laborious.
Summary of the invention
As described in the background section, common weight cart still inevitably needs first to remove weight to cartOn, and from the design of current various carts, for the stationarity for maintaining cart to carry out, in cart front end often notIt is the weight receiving structure on cart, therefore, even if still there are a certain distance with weight by cart close to weight.In order toExempt weight and move the step onto cart, save labour, it is proposed that will partially be blocked in weight when cart is close to weightStop portions (being often in the front end of cart) removal or bending between object and weight receiving structure, make weight receive knotStructure is closer to weight, however bend or remove in stop portions (obviously has the similar work for changing cart center of gravity with bendingWith) after, the center of gravity of entire cart is likely occurred transfer, and weight receiving structure can occur when receiving weight because of gravity center instabilityIt is unexpected.
A technical problem underlying to be solved by this invention is exactly cart weight after the bending of cart stop portions or removalObject receiving structure receives the problem that accident can occur when weight because of mass centre changing shakiness.
Load transport vehicle of the present invention, including vehicle frame, it is characterised in that the vehicle frame include frame body, movable end,It is arranged on movable end and is furnished with the movable end bull stick of first gear and is arranged in frame body and equipped with second gearTurbine wheel shaft, the first gear drive second gear, and the frame body is additionally provided with the third engaged with the turbine in turbine wheel shaftGear and movable supporting leg with third gear axis connection.
Movable end of the present invention can be to stablize the stationarity of weight transfer cart transport and be located at weight transfer cartThe part vehicle frame of front end, the stationarity are based on those skilled in the art to the theoretical judgment of structure stress balance.
After the movable end relative frame ontology rotation, movable end bull stick will be driven by first gear and second gearTurbine wheel shaft rotation, and the turbine in turbine wheel shaft drives the rotation of movable supporting leg by third gear, so that movable end is in phaseAfter frame body rotation, it can be replaced by movable supporting leg, the center of gravity of vehicle frame is made not change.First gear and the second toothWheel can be engaged directly, and rotating mechanism, such as gear set also can be set.
Even if the rotation (such as 15 °) of minute angle occurs for the movable end relative frame ontology, movable supporting leg is theIt can occur to rotate completely under the drive of three gears, that is, be entirely used for support frame body, those skilled in the art only need to adjustThe gear ratio of first gear and second gear can be realized easily.In fact, the rotation of minute angle has resulted in vehicle frame weightThe change of heart position, although in many cases, such change in location be it is smaller, after weight is moved in vehicle frame,Vehicle frame entirety gravity sharply increases, it would still be possible to accident occur because of center of gravity imbalance.It can be true using technical solution of the present inventionAfter the rotation of keep-alive moved end, the positional shift of frame mass centre is in controlled range always.
However, those skilled in the art are after continuing relative frame ontology rotation movable end, movable supporting leg still may be afterContinuous rotation, to lose the function of support frame body, therefore as further technological improvement, vehicle frame of the present invention is also wrappedInclude answering for connector, connection movable end bull stick and the turbine wheel shaft being inserted at least partly movable end bull stick or at least partly turbine wheel shaftPosition part and the fulcrum block in frame body and movable end relative rotation direction, the movable end are stretched multiple by fulcrum blockPosition part, the connector include the sliding sky slided for the movable end bull stick or the turbine wheel shaft along return unit draw directionBetween.
Movable end relative frame ontology rotational angle be more than a certain range after, movable end is divided into two by the fulcrum blockPart, described two parts respectively fulcrum rotation in fulcrum block, to stretch return unit, makes first gear and second gearIt is located remotely from each other, first gear is made not have the function of driving second gear.The fulcrum block can be set in movable end or vehicle frameOn ontology, or an individual components are pinched when needed between movable end and frame body.It is any with reset functionStructure may act as return unit of the present invention, be under normal conditions reset spring.
It is that existing cart still needs during push weight that the present invention, which needs another technical problem underlying solved,The problem of expending the manpower for maintaining cart balance, present invention employs following schemes:
The vehicle frame further includes bearing base, by the far vane connecting on transporting heavy things to bearing base and with bearing base and companyThe bindiny mechanism of frame body and bearing base is met, the bindiny mechanism includes:
Rotating part rotates bearing base relative frame ontology at least between object location and load-bearing position connecing；
And
Clutch part relatively rotates bearing base and frame body or opposing stationary；
The clutch part includes extensible member and abutment, and when so that extensible member being in stretching state, abutment is closeAnd extensible member is resisted, and when extensible member is in contraction state, abutment relative telescopic part is freely rotated；
When bearing base, which is located at, connects object location, the weight is carried by far vane, when bearing base is located at load-bearing position, instituteWeight is stated at least to be carried by bearing base.
The program at least makes those skilled in the art when pushing load transport vehicle or starting load transport vehicle, it is not necessary to willStrength is wasted in the relative equilibrium for maintaining bearing base and frame body, it is intended to it avoids after load transport vehicle starts transport,Bearing base relative frame ontology deflects and influences the normal transport operation of load transport vehicle.
More critically, bearing base is automatically performed from connecing object location and turn to load-bearing position, art technologyPersonnel exert a force to bearing base, make bearing base that the conversion of position occur, when bearing base goes to load-bearing position, bearing base passes through clutchWhat the effect nature of component can consolidate is located in frame body, any inclined without occurring in load transport vehicle transportational processTurn.
In addition, the bearing base be free to be rotated between object location and load-bearing position connecing, technical staff only needs letterSingle adjustment clutch part, can complete the conversion of bearing base position, such as when bearing base goes to load-bearing position, make extensible memberIn contraction state, bearing base can automatically return to and connect object location, greatly simplify the tedious steps of weight carrying.
Detailed description of the invention
Fig. 1 is a kind of overall structure diagram of load transport vehicle described in embodiment 1；
Fig. 2 is the structural schematic diagram of the first rotating block and the second rotating block described in embodiment 1；
Fig. 3 is the amplification schematic cross-section of abutment described in embodiment 1；
Fig. 4 is the partial enlargement structural representation of frame body described in embodiment 1 Yu bearing base junction；
Fig. 5 is another partial enlargement structural representation of frame body described in embodiment 1 Yu bearing base junction；
Fig. 6 is a kind of partial structural diagram of load transport vehicle described in embodiment 2.
Specific embodiment
Present embodiment is the supplement and detailed description to Summary.
Summary describes a kind of load transport vehicle, which includes frame body and bearing base, withIt realizes rotation of the bearing base in frame body and keeps bearing base opposite with frame body at least through clutch part when neededStatic, on this basis, the present invention further passes through three aspects and advanced optimizes.
One, the optimization that manpower is paid further is saved
For metal cylinder, the number of the liquefied gas in bottle will affect the center of gravity of metal cylinder, therefore, for differenceThe metal cylinder of center of gravity, is shipped on bearing base, and to go to the manpower paid of carrying position complete from object location is connect for bearing baseIt is complete different, need the rotation axis to bearing base relative frame ontology to be adjusted, the technical solution that the present invention provides be make it is describedRotating part includes the rotating member for being rotatablely connected frame body and bearing base, is fixed on rotating member and slides at least on bearing baseThe slidable adjustment component of dynamic moving member and adjusting moving member sliding distance on bearing base.
Moving member is relative to the movement of bearing base, and can be there are two types of situation: the first, bearing base be fixed, and moving member is mobile；TheTwo, moving member is fixed, and bearing base is mobile.When moving member is mobile relative to bearing base, only moving member is moved, the present inventionThe sliding position for moving member sliding is additionally arranged in the frame body, so that moving member can slide on sliding position, in addition,The rotating part further includes the positioning element being respectively located in moving member on bearing base and frame body, so that positioning elementWhen release, moving member slides on bearing base and frame body；When positioning element positions, moving member is fixed on bearing base and vehicle frameOn ontology.When those skilled in the art need to change the position of rotating member, positioning element is unclamped, and rotate bearing base, make load-bearingSeat maintains an equal level with frame body, so as to slide moving member on bearing base and frame body simultaneously, mixes up the position of moving member,Then moving member is positioned with positioning element again, is fixed on moving member in bearing base and frame body.
When bearing base relative movable parts are mobile, only bearing base is moved, and can at least make in clutch part in this wayExtensible member and abutment are separated from each other, and so that clutch part is lost the clutch function to bearing base and frame body, for this purpose, this hairThe bright rotating part further includes the fixed clutch part moving member slided in frame body on the clutch partner and at least.FromPartial movement part is closed with bearing base synchronizing moving, and can be filled using the positioning same or like with the positioning elementIt sets and clutch part moving member is positioned.
In order to adapt to sliding of the moving member on bearing base and/or frame body, it can be equipped with and appoint for moving member and bearing baseWhat matched slide construction, such as pulley and sliding rail, sliding slot and sliding block etc., in addition, the present invention is also equipped with for slide constructionSlidable adjustment component, the slidable adjustment component are used for sliding distance of the adjustment slide on bearing base, thus technical staff may be usedThe case where according to metal cylinder center of gravity, changes rotating member in bearing base by adjusting sliding distance of the moving member on bearing baseIt is the location of middle.
A kind of slidable adjustment component includes the screw rod being arranged on bearing base and the screw hole that is fixedly connected with moving member,Screw rod passes through screw hole, rotary screw rod hole can screw rod bearing base relative movable parts can be driven mobile.
Two, increase stability of the bearing base with frame body after opposing stationary
Object location is held from connecing object location and going to, bearing base is static by relative frame ontology, and bearing base passes through clutch part at this timeDivide and remain stationary the gravity that metal cylinder will be born in state, clutch part and coupling part with coupling part relative frame ontology,In transporting heavy things transport, inevitable road jolts, and can potentially damage the mechanical structure of clutch part and coupling part,It is permanent previous, it may occur that harmful deformation is so that lose corresponding function, and exacerbate metal cylinder during transportationVibration amplitude, the transport for some hazardous chemicals, this is clearly unacceptable.
For this purpose, the present invention in connection bearing base and the part of frame body, i.e., clutch part and coupling part, which are provided with, addsFixing structure.Compared to some cumbersome ruggedized constructions, ruggedized construction of the invention is simple and effective.For coupling partSpeech, the present invention make the rotating member include that the first rotating block connecting with frame body and second connect with bearing base rotateBlock, first rotating block and the second rotating block corresponding section are equipped with lock hole.For clutch part, the present invention makes extensible memberPlace opposite with abutment is equipped with lock hole.Locking pin is inserted into the lock hole, locking pin can be made to bear metal cylinderGravity, can reduce metal cylinder in this way and entire clutch part or/and coupling part damaged during transportation.
Three, the optimization of frame body and movable end connection structure and dependency structure
Load transport vehicle of the present invention, including vehicle frame, the vehicle frame include frame body, movable end, setting in activityOn end and it is furnished with the movable end bull stick of first gear and is arranged in frame body and is furnished with the turbine wheel shaft of second gear, it is describedFirst gear drives second gear, and the frame body is additionally provided with the third gear engaged with the turbine in turbine wheel shaft and with theThe movable supporting leg of three gear axis connections.The movable end should keep original state (phase with frame body in its natural stateFor the rotation of movable end relative frame ontology, namely do not rotate), therefore movable end bull stick is equipped with resetting-mechanism, instituteResetting-mechanism is stated to continue to apply the power for resetting movable end to movable end in the rotation of movable end relative frame ontology, it is any to haveThe component of reset function can be used as resetting-mechanism, such as reduction torsion spring, reset spring, reset strut etc..
These return units when movable end is in original state are generally possible to that movable end is made to continue to keep original state, butDuring load transport vehicle transport, jolting for road conditions is transported, it is possible to movable end can be rotated to relative frame ontologyDirection pushes, and causes movable end to swing, thus the present invention also provides fixed link, the movable end and frame body are equipped with confessionFixed link is each passed through the fixation hole in frame body and movable end i.e. by the fixation hole that fixed link passes through, those skilled in the artIt can.
Embodiment 1
See Fig. 1-5, a kind of load transport vehicle, including frame body 1, bearing base 2,4 rollings for being arranged under frame body 1The bindiny mechanism of wheel 3 and connecting vehicle frame ontology 1 and bearing base 2.
Frame body 1 is used to support entire bearing base 2 and constitutes the vehicle frame of load transport vehicle, including frame body ontology 4And movable end 5, the movable end 5 are connect with 4 articulated shaft 6 of frame body ontology, so that movable end 5 can be with relative frame ontologyOntology 4 rotates, and movable end 5 can be usually freely rotated with relative frame ontology ontology 4, but 5 relative frame ontology ontology 4 of movable endThere are two classical positions for turned position: the first, 5 relative frame ontology ontology of movable end is in closed state, i.e. movable end 5 and vehicleFrame ontology ontology 4 is in same plane (i.e. the state of movable end on the left of Fig. 1)；The second, 5 relative frame ontology ontology 4 of movable endIn fully unfolded position, at this point, plane locating for movable end 5 is in 90 ° relative to the plane of frame body ontology 4.5 phase of movable endFrame body ontology 4 is between above-mentioned two classical position, is unfolded state (i.e. the state of movable end on the right side of Fig. 1).
In the present embodiment, the movable end 5 and 4 articulated shaft 6 of frame body ontology are hinged, on articulated shaft 6 furtherReduction torsion spring 7 is set, and in the case where other no external force, movable end 5 can automatically reset under the action of reduction torsion spring 7 and closeConjunction state, the movable end 5 are typically provided with brake structure with frame body ontology 4, such as in the present embodiment, movable end 5 withFrame body ontology 4 is equipped with fixation hole (Fig. 1 does not show), and fixed link is inserted into movable end 5 and vehicle by those skilled in the art respectivelyFixation hole on frame ontology ontology 4, so that it may prevent completely the rotation of 5 relative frame ontology ontology 4 of movable end, the fixation holeSetting can according to those skilled in the art operate load transport vehicle when, according to the needs of use, make plane locating for movable end 5 withPlane stability locating for frame body ontology 4 is in a specific angle, such as 0 °, 90 ° or other angles.
The bearing base 2 includes bearing base 8 and the far vane 9 positioned at 8 bottom of bearing base, and far vane 9 is convenient for metalGas cylinder, which is transported on bearing base 2, to be arranged, and the present embodiment is the plate 9 for being inserted into metal cylinder bottom.
Bindiny mechanism includes rotating part and clutch part, and the rotating part can make 2 relative frame sheet of bearing baseBody 1 is freely rotated, but also there are two classical positions for the turned position of 2 relative frame ontology 1 of bearing base:
Object location is connect, at this point, the weight of metal cylinder is undertaken by far vane 9 substantially, usually connecing object location is to make far vane 9Positioned at the position of 2 lowest part of bearing base, but more common definition should be the pose pattern according to metal cylinder, and most can be advantageousThe position of far vane 9 is moved in metal cylinder.
Load-bearing position, at this point, the weight of metal cylinder is undertaken by bearing base 8 substantially, the load-bearing position is to make metal gasBottle is firm to be placed on transport vehicle described in the present embodiment, and the position consolidated when transport is at least kept, and what Fig. 1 was shown is exactly a kind ofLoad-bearing position.
To realize that bearing base 2 connecing the rotation between object location and load-bearing position, rotating part includes connecting vehicle frame sheetThe rotating member of body 1 and bearing base 2, the rotating member include the first rotating block 10 being connect with frame body 1 and with bearing base 2Second rotating block 11 of connection, the first rotating block 10 and the second rotating block 11 are rotatablely connected.
In load-bearing position or object location is connect, bearing base 2 can be automatically positioned in frame body 1, and the present embodiment passes throughClutch part realizes this function, and the clutch part includes the extensible member being fixed on bearing base 2 and is fixed on vehicle frameAbutment on ontology 1, extensible member include the telescopic seat being fixed on bearing base 2, reset spring 12 and telescopic pin 18, are stretchedSeat end is the movable chamber 13 being made of two fixed plates 30, and the two fixed plates 30 are equipped with leads to for what telescopic pin 18 passed throughHole, reset spring 12 is between two fixed plates 30, and one end is against in one piece of fixed plate 30 therein, and the other end is against and setsSet in the projection 31 in telescopic pin 18, in this way pulling telescopic pin 18 will compression reseting spring 12, thus in natural conditions,Flexible plunger 32 is always stretched out movable chamber 13 due to the effect of reset spring 12 by telescopic pin, and plunger 32 of stretching is close in abutmentThe side of extensible member is equipped with inclined-plane, and abutment includes that the effect end 16 of telescopic pin 18, the effect end 16 are compressed by the inclined-planeIt is additionally provided with and keeps out hole 17 for what the flexible plunger 32 passed through.The other end of the 18 relative telescopic plunger 32 of telescopic pin is to stretchEnd 33, with after pulling and stretching and stretch end 33, flexible plunger 32 will exit technical staff from keeping out in hole 17, and bearing base 2 again can be withRelative frame ontology 1 is freely rotated.
When multiple abutments are arranged in frame body, then extensible member passes through these abutments, so that it may be located in abutmentIt in frame body on location, realizes in addition to connecing object location and load-bearing position, the position of other positioning bearing bases.WhenSo, extensible member and abutment can also be separately positioned on frame body and bearing base.
The present embodiment is respectively provided with one first turn of axis connection respectively on the first rotating block 10 and the second rotating block 11The axis hole 19 of motion block 10 and the second rotating block 11 and with the equidistant satellite hole 20 of axis hole 19, specifically, in the first rotationTwo satellite holes 20 are set on block 10, a satellite hole 20 is then only set on the second rotating block 11, rotate bearing base 2, make theThe satellite hole of one rotating block 10 is opposite with the satellite hole of the second rotating block 11, is inserted into locking pin at this time, then bearing base 2 can be made to positionIn frame body 1, but more importantly, the weight of metal cylinder will by rotating member shaft 44 and locking pin shared,Stability of the bearing base 2 in frame body 1 is increased, the stability is sayed if of the invention in specific embodiment part,It can be improved service life of the load transport vehicle under the road conditions jolted.
Rotating part described in the present embodiment further includes moving member, and the moving member is that 11 bottom end of the second rotating block is arranged inTwo threaded rods 40, bearing base 2 are equipped with the elongated hole 41 passed through for two threaded rods 40, and bearing base 2 is pushed to make twoThreaded rod 40 moves in elongated hole 41, when arriving suitable position, then threaded rod 40 is fixed on elongated hole 41 with nut, is examinedThe weight for considering metal cylinder passes through 41 pressure-bearing of elongated hole on rotating member 2, to prevent elongated hole 41 due to metal cylinder is overweightLead to certain deformation, the present embodiment is also provided with bearing base reinforcement feature, and the bearing base reinforcement feature includes that setting is being heldTwo casings 42 on weight seat 2 and across the second rotating block 11 and the reinforcing bar 43 that is fixed to each other with the second rotating block 11,43 both ends of reinforcing bar are equipped with screw thread, and the through-hole passed through for 43 both ends of reinforcing bar is equipped on two casings 42, to be addedAfter 43 both ends of solid rod are each passed through through-hole, the fixation just realized between bearing base 2 and the second rotating block 11 is screwed respectively with nut,So as to greatly mitigate the gravity that metal cylinder is applied on elongated hole 41.
In specific embodiment part, the present invention recommend it is a kind of adjusting moving member with respect to 2 moving distance of bearing base portionPart, such component also can be applied on the present embodiment, i.e., threaded hole and silk are respectively set on moving member and bearing base 2Bar, makes screw rod pass through threaded hole, and such rotary screw rod can arbitrarily adjust the moving distance of 2 relative movable parts of bearing base.
In the present embodiment, bearing base reinforcement feature mentioned above has use in many places, these reinforcement features haveSimilar structure, such as frame body ontology reinforcement feature is just equipped on frame body ontology 4, it is equipped with and lives on movable end 5Moved end reinforcement feature, the frame body ontology reinforcement feature include two casings 45 being arranged on frame body ontology,The locating rod 47 and slided on frame body ontology 4 and be arranged in first that reinforcing bar 46 and reinforcing bar 46 are welded as a wholeFirst rotating block pedestal 48 of 10 bottom of rotating block, the first rotating block pedestal 48 are equipped with the elongated hole passed through for locating rod 4749, locating rod 47 and reinforcing bar 46 weld one end and are equipped with nut, and by tightening nut just the first rotating base 48 can positionOn frame body ontology 4.46 both ends of reinforcing bar are equipped with screw thread, are equipped on two casings 45 for 46 liang of reinforcing barHold across through-hole, after 46 both ends of reinforcing bar are each passed through through-hole, screwed respectively with nut just realize frame body ontology 4 withFixation between second rotating block 10, so as to greatly mitigate the gravity that metal cylinder is applied on elongated hole 49.
Movable end reinforcement feature is identical as frame body ontology reinforcement feature, is not described.Obviously, in the present embodiment,Frame body ontology reinforcement feature and movable end reinforcement feature have also each served as the function of clutch part moving member and moving memberEnergy.
Using when load transport vehicle, pushing directly at transport vehicle to metal cylinder described in the present embodiment, movable end 5 is unfolded,And bearing base 2 is in and connects object location, and far vane 9 is made to be inserted into metal cylinder bottom, completes metal cylinder and transports to load transport vehicleOperation, be then log out load transport vehicle, movable end 5 is closed automatically by reduction torsion spring 7, is rotated further by bearing base 2 to carrying positionIt sets.
Embodiment 2
Embodiment 2 provides another load transport vehicle, and the load transport vehicle and embodiment 1 are almost the same, differenceIt is the join domain of movable end and frame body, sees Fig. 6, the reduction torsion spring in embodiment 1 is arranged on movable end bull stick 69,To prevent 61 relative frame ontology 60 of movable end from rotating.
See that Fig. 6, the movable end 61 are equipped with movable end bull stick 69, are equipped with first gear 62, vehicle in the middle part of movable end bull stick 69Frame ontology 60 is equipped with the attachment base 70 of intermediate rotary shaft 68, turbine wheel shaft 66 and connection intermediate rotary shaft 68 and turbine wheel shaft 66, and centre turnsThe intermediate gear 71 engaged with first gear 62 is equipped in the middle part of axis 68, turbine wheel shaft 66 is equipped with second engaged with intermediate gear 71Gear 64, the frame body 60 be additionally provided with the third gear 67 engaged with the turbine in turbine wheel shaft and with 67 axis of third gearThe movable supporting leg 65 of connection, the attachment base 70 are equipped with the bearing block of support 67 axis of third gear.
Movable end bull stick 69 is connect with intermediate rotary shaft 68 by connector 63, and the connector 63 is equipped with long hole for movable endBull stick 69 is inserted into and can slide in the range of long hole.Connection movable end bull stick 69 and intermediate rotary shaft 68 is not shown in Fig. 6Reset spring, the effect of the reset spring is further the distance between movable end bull stick 69 and intermediate rotary shaft 68, makes firstGear 62 and 71 toe joint of intermediate gear, Fig. 6 is also not shown simultaneously relatively rotates direction positioned at frame body 60 and movable end 61On fulcrum block, the fulcrum block is generally arranged in movable end 61 or frame body 60, is located at movable end 61 close to vehicleOne end of frame ontology 60 or frame body 60 are close to one end of movable end 61, it is not shown, but retouching in the present embodimentThe human-subject test below with reference to those skilled in the art is stated, is not difficult to implement technical solution described in the present embodiment.In addition, this implementationIntermediate gear 71 and intermediate rotary shaft 68 in example can remove completely, and be substituted respectively by second gear 64 and turbine wheel shaft 66, withDrive mechanism is reduced, the energy loss in transmission process is reduced.
Movable end is divided into two parts by the fulcrum block, and after rotating movable end 61, first gear 62 passes through intermediate gear71, second gear 64, turbine finally drive movable supporting leg 65 rotate, make movable supporting leg 65 support frame body 60, when turnWhen dynamic angle is more than a certain range, the respectively fulcrum rotation in fulcrum block of described two parts, so that reset spring is stretched,Keep first gear 62 and intermediate gear 71 and second gear 64 separate, first gear 62 is made not have the function for driving second gear 64Can, at this moment, even if continuing to rotate movable end 61, movable supporting leg 65 will not be made to rotate.