Abstract:
The present invention relates to a hand lift Hand Truck, especially a kind of lorry Hand Truck with an adjustable carrier, including a chassis, a carrier and a lifting device. The lifting device has a moveable pulley block on the carrier, a fixed pulley block on the chassis and a pull rope passing round the fixed pulley block and the moveable pulley block in turn and the end of the pull rope is wrapped at a winding axis, rotatable on the chassis, a locking device between the chassis and the winding axis is used to control the pivoting of the winding axis. When the said hand Portable Lift Hand Truck is working, the winding axis is rotating and the pull rope is wound around the winding axis, thus to drive the moveable pulley block and the fixed pulley block to bring the carrier moving up and down, the locking device can stop the carrier at any height for convenience. The utility model is able to lift the goods to a height for operator&#39;s easy handling without bending over again and again; at the same time, as there are several moveable pulleys, the handling is easier and more efficient.

Description:
FIELD OF THE INVENTION  
       [0001]     The present utility model relates to a hand lift Hand Truck, especially a Portable Lift Hand Truck for lifting goods.  
       BACKGROUND TECHNOLOGY  
       [0002]     Based on the existing technology, the lightweight Portable Lift Hand Truck normally includes chassis, at least one pair of wheels rotatablely connected to the bottom of the said chassis, a handle on the upper end of the said chassis, a Hand Truck on the base of the said chassis for place goods. When using, the operators have to bend over to fetch or place goods, that may bring intensive labor and fatigue, even cause lumbar vertebrae diseases after long time working.  
       SUMMARY OF THE INVENTION  
       [0003]     The present utility model provides a Portable Lift Hand Truck for lifting goods and it can lift the goods from the ground to a comfortable height conveniently.  
         [0004]     The technical proposal of the present utility model is: A hand Portable Lift Hand Truck comprising: a chassis, a carrier, the said carrier is able to move up and down on the said chassis with the help of a lifting device, at least a pair of wheels, which are rotatablely connected to the said chassis, a handle on the upper end of the chassis; the said lifting device has a moveable pulley block on the carrier, a fixed pulley block on the chassis and a pull rope passing round the fixed pulley block and the moveable pulley block in turn, the said fixed pulley block is above the said carrier and the end of the pull rope is wrapped at a winding axis, rotatable on the chassis, a locking device between the chassis and the winding axis is used to control the pivoting of the winding axis.  
         [0005]     When the operators are handling, they can rotate the rocking handle to wrap the pull rope into the winding axis, and the moveable pulley block and the fixed pulley block will drive the carrier moving up and down along the guide way, the locking device can stop the carrier at any height for convenient handling.  
         [0006]     As the above technical proposal is applied, the present utility model is able to lift the goods to a height for operator&#39;s easy handling without bending over again and again; at the same time, as there are several moveable pulleys, the handling is easier and more efficient. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a schematic front elevation of embodiment 1 of a Portable Lift Hand Truck according to the present invention.  
         [0008]      FIG. 2  is a left view of embodiment 1 of a Portable Lift Hand Truck according to the present invention.  
         [0009]      FIG. 3  is a schematic elevation of service mode of embodiment 1 of a Portable Lift Hand Truck according to the present invention.  
         [0010]      FIG. 4  is a schematic elevation showing the state of locking of the locking device of embodiment 1 of a Portable Lift Hand Truck according to the present invention.  
         [0011]      FIG. 5  is a schematic elevation showing the state of unlocking of the locking device of embodiment 1 of a Portable Lift Hand Truck according to the present invention.  
         [0012]      FIG. 5  is a schematic elevation showing the state of folded handle of embodiment 1 of a Portable Lift Hand Truck according to the present invention.  
         [0013]      FIG. 7  is a back view of embodiment 2 of a Portable Lift Hand Truck according to the present invention (there is a retraction device on the chassis).  
         [0014]      FIG. 8  is a right view of the locking device of embodiment 2 of a Portable Lift Hand Truck according to the present invention  
         [0015]      FIG. 9  is a schematic cross-sectional elevation taken along line A-A of  FIG. 8   
         [0016]      FIG. 10  is a schematic cross-sectional elevation of the locking device of embodiment 2 of a Portable Lift Hand Truck according to the present invention  
         [0017]      FIG. 11  is a schematic elevation of the retraction device of embodiment 2 of a Portable Lift Hand Truck according to the present invention (the elastic piece is located on the end axis)  
         [0018]      FIG. 12  is a close-up view of B in  FIG. 11   
         [0019]      FIG. 13  is a K-direction view of  FIG. 12   
         [0020]      FIG. 14  is a schematic elevation of the retraction device of embodiment 2 of a Portable Lift Hand Truck according to the present invention (the elastic piece is located between the first connecting rod and the second connecting rod within one retraction unit)  
         [0021]      FIG. 15  is a back view of embodiment 2 of a Portable Lift Hand Truck according to the present invention (there is a retraction device on the chassis).  
         [0022]      FIG. 16  is a back view of embodiment 3 of a Portable Lift Hand Truck according to the present invention.  
         [0023]      FIG. 17  is a schematic elevation of service mode of embodiment 3 of a Portable Lift Hand Truck according to the present invention (back view).  
         [0024]      FIG. 18  is a top view of embodiment 3 of a Portable Lift Hand Truck according to the present invention.  
         [0025]      FIG. 19  is a close-up view of C in  FIG. 18   
         [0026]      FIG. 20  is a schematic front elevation of the sleeve of embodiment 3 of a Portable Lift Hand Truck according to the present invention.  
         [0027]      FIG. 21  is a bottom view of the sleeve of embodiment 3 of a Portable Lift Hand Truck according to the present invention.  
         [0028]      FIG. 22  is a top view of the sleeve of embodiment 3 of a Portable Lift Hand Truck according to the present invention.  
         [0029]      FIG. 23  is a schematic front elevation of the pulley housing of embodiment 3 of a Portable Lift Hand Truck according to the present invention.  
         [0030]      FIG. 24  is a bottom view of the pulley housing of embodiment 3 of a Portable Lift Hand Truck according to the present invention.  
         [0031]      FIG. 25  is a schematic cross-sectional elevation taken along line D-D of  FIG. 23   
     
    
       [0032]     Of which:  1 . chassis;  11 . longitudinal beam;  111 . projecting lug;  12 . handle;  13 . wheel;  14 . guide way;  15 . lead block;  16 . baffle;  17 . cross beam;  
         [0033]      2 . carrier;  21 . roller;  22 . loading part;  221 . slope;  23 . fix part;  
         [0034]      3 . lifting device;  31 . moveable pulley block;  32 . fixed pulley block;  33 . pull rope;  34 . pulley housing;  341 . the first fairlead;  35 . pulley;  
         [0035]      4 . locking device;  41 . stop lever;  42 . ratchet;  43 . claw;  44 . friction wafer;  441 . internal friction wafer;  442 . external friction wafer;  45 . reset torsion spring;  
         [0036]      5 . winding axis;  51 . rocking handle;  511 . hand grip;  52 . central axis;  522 . end cap;  53 . winding roller;  54 . elastic friction piece;  55 . sleeve;  551 . the second fairlead;  
         [0037]      6 . retraction device;  61 . retraction unit;  611 . the first connecting rod;  612 . the second connecting rod;  613 . intersecting axis;  614 . end axis;  62 . elastic piece;  63 . towing line;  
       DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0038]     FIGS.  1  to  6  illustrate a first embodiment of a Portable Lift Hand Truck according to the present invention. The hand Portable Lift Hand Truck comprising: a chassis  1 , at least a pair of wheels  13 , which are rotatablely connected to the said chassis  1 , a handle  12  on the upper end of the chassis  1  (refer the “upper” and “lower” positions to the  FIG. 1 ), and the chassis  1  is made up of a pair of longitudinal beams  11  extending vertically and a cross beam  17  traversing a pair of longitudinal beams  11   
         [0039]     On the opposite sides of a pair of longitudinal beams  11 , there are guide ways  14  extending vertically, the carrier  2  is connected to the guide ways  14  and is moveable; on the two opposite sides of the carrier  2 , there are rotatable rollers  21 , the rollers  21  are located inside the guide way  14  and in rolling contact with the inner wall of the guide wall  14 , the carrier  2  could move freely along the guide way  14  through a lifting device  3 . in order to make the carrier  2  fully stressed and move smoothly, the two rollers  21  on the each side should be located on the upper and lower end of the carrier  2 , the width of the opening of the guide way  14  is less than the width of the inside, these structures achieve a rolling friction contact between the carrier  2  and the guide way  14 , so the carrier  2  could move up and down along the guide way  14  very smoothly and the rollers  21  will not escape from the guide way  14   
         [0040]     The lifting device  3  has a moveable pulley block  31  on the carrier  2 , a fixed pulley block  32  on the chassis  1  and a pull rope  33  passing round the fixed pulley block  32  and the moveable pulley block  31  in turn, the fixed pulley block  32  is above the carrier  2 , the starting end of the pull rope  33  is fixed at the cross beam  17  and the end of the pull rope  33  is wrapped at a winding axis  5 , which is rotatable on the chassis  1 , a locking device  4  between the chassis  1  and the winding axis  4  is used to control the pivoting of the winding axis  5 . the rocking handle  51  is connected to the end of the winding axis  5 , turning the rocking handle  51 , the winding axis will be rotated as well to wind or release the pull rope  33 , in order to save space, There is a folding hand grip  511  on the rocking handle  51 , and at the same time, the hand grip  511  can elastically fixed to the rocking handle  51  with a spring, thus the hand grip  511  could keep two positions of using and folded stably, see  FIG. 6 .  
         [0041]     In  FIGS. 4 and 5 , the locking device  4  includes a rocking handle  51  and a stop lever  41  by the rocking handle  51 , the stop lever  41  is rotatively connected to the chassis  1 , when the locking device  4  is working, the stop lever  41  will stop the rocking handle  51 ; and when the locking device  4  is released, the stop lever  41  will leave the rocking handle  51 .  
         [0042]     When working, the goods are placed on the carrier  2 , then rotating the rocking handle  51  to drive the winding axis  5  to wind the pull rope  33 , with the combined action of the fixed pulley block  32  and the moveable pulley block  31 , the carrier  2  is lifted to a desired height, the said carrier  2  move upwards along the guide way  14  to the desired position, see  FIGS. 3 and 4 ; toggling the stop lever  41  to stop the rotation of the rocking handle  51  from the side, then the carrier  2  will be fixed to the chassis  1 ; when releasing the carrier  2 , toggling the stop lever  41  to leave the rocking handle  51 , rotating the rocking handle  51  reversely to release the pull rope  33 , the carrier  2  will be retracted to the bottom as of the forces of gravity, see  FIGS. 2 and 5 . As several moveable pulley blocks are applied, heavy goods can be lifted easier, thus to improve working efficiency.  
         [0043]     The carrier  2  has a loading part  22  and a fix part  23 , the moveable pulley block  31  is fixed to the fix part  23  and the loading part  22  extends to a horizontal plane and the end of the loading part  22  distal from the fix part  23  has a slope  221 , thus the carrier can carry the goods more easily, and then the operator just needs to rotate the rocking handle  51  to lift the goods easily. The operators need not to bend over again and again, thus to reduce labor intensity and save human resources.  
         [0044]     FIGS.  7  to  15  illustrate a second embodiment of a Portable Lift Hand Truck according to the present invention. The difference between these embodiments and the first one is that: there is a retraction device  6  between the chassis  1  and the carrier  2  to make the carrier  2  move down quickly,  FIG. 7  shows a retraction device  6  on the chassis  1  and  FIG. 15  shows a pair of retraction devices on the chassis  1  and several retraction devices  6  are available according to the demands.  
         [0045]     The said retraction device  6  has several retraction units  61  connecting one after another, the said retraction unit  61  has intercrossed first connecting rod  611  and second connecting rod  612 , the length of the first connecting rod  611  is the same as that of the second connecting rod  612  and the intersecting position is in the middle of the first connecting rod  611  and the second connecting rod  612 .  
         [0046]     The first connecting rod  611  and the second connecting rod  612  are hinge connected at the intercross; the upper end of the first connecting rod  611  of each retraction unit is hinge connected to the lower end of the second connecting rod  612  of the upside adjacent retraction unit, and the lower end of the first connecting rod  611  of each retraction unit is hinge connected to the upper end of the second connecting rod  612  of the downside adjacent retraction unit, and in at least one of the said several retraction units  61 , there is an elastic piece  62  between the first connecting rod  611  and second connecting rod  612 .  
         [0047]     The elastic piece  62  has many options, for example, if use tension spring as the elastic piece  62  and it is located at the upper end of the first connecting rod  611  and the second connecting rod  612  within one retraction unit  61 , see the  FIG. 14 , when the carrier  2  is lifted, the tension spring is forced to extend and when the carrier  2  is released, the torsion spring will come back quickly, the tension of spring make the first connecting rod  611  and the second connecting rod  612  move close to each other, as the several retraction units are linked, so the first connecting rod  611  and the second connecting rod  612  drive the entire retraction device  6  opening out, and then the carrier  2  is push off quickly; compressed spring is also available, it should be located between the lower ends of the first connecting rod  611  and the second connecting rod  612  within one retraction unit  61 , when the carrier  2  is lifted, the elastic piece  62  is compressed and when the carrier  2  moving down, the elastic piece  62  will release elastic force to drive the carrier  2  move down quickly.  
         [0048]     Of which, FIGS.  11  to  13  illustrate another preferred plan of a second embodiment of a Portable Lift Hand Truck according to the present invention. the first connecting rod  611  is hinge connected to the second connecting rod  612  at the intercross by the intersecting axis  613 , and the first connecting rod  611  is hinge connected to the second connecting rod  612  at the end by the end axis  614 , and the elastic piece  62  is torsion spring and is located on one end axis  614 , normally, in order to achieve force balance, we will set torsion springs on a symmetrical pair of the end axis  614 , thus to avoid deflection of the carrier  2 . Sometimes, the elastic piece  62  can also be set on the intersecting axis  613 , but in that case, the elastic force of the torsion spring shall be greater.  
         [0049]     The advantage is that: as the Portable Lift Hand Truck applies the retraction device  6  with the linkage structure, one more driving force exerted on the carrier  2  when the carrier  2  is moving down, thus to prevent the carrier  2  from being blocked when moving as lacking of force of gravity, and the problem of slow lowering rate and unsmooth lowering of the carrier  2  is solved.  
         [0050]     Besides, FIGS.  8  to  10  illustrate a locking device of another structure: the locking device  4  includes the ratchet  42  on the same winding axis  5  and the claw  43  on the chassis  1  to prevent the ratchet  42  from moving, the claw  43  engages with the ratchet  42 .  
         [0051]     The winding axis  5  includes a central axis  52  and a winding roller  53  fixed to the central axis  52 , the diameter of the winding roller  53  is more than that of the central axis  52 ; there is a rocking handle  51  on the winding axis  5 , there is a section of thread on the central axis  52  and there are screws on the rocking handle  51 , the rocking handle  51  is connected to the central axis  52  by such thread and screws. At the end of the central axis  52  connected to the rocking handle  51 , there is a fixed end cap  522 , and there is an elastic friction piece  54  between the end cap  522  and the rocking handle  51 ; There is a friction wafer  44  between the ratchet  42  and the rocking handle  51 ; There is a reset torsion spring  45  between the claw  43  and the chassis  1  for the claw  43  to reset. The elastic friction piece  54  in the embodiment is the compressed spring.  
         [0052]     The winding axis  5  and the locking device  4  can form two working states, and they are winding condition and winding-release condition; under the winding condition, the two sides of the friction piece  44  tightly contact with the ratchet  42  and the rocking handle  51  respectively, that means the winding roller  53  contacting with the ratchet  42  tightly and thus the ratchet  42  and the winding axis  5  are under rotary retaining and connected; when under the winding-release condition, the two sides of the friction piece  44  separate from the ratchet  42  and the rocking handle  51  respectively, and the ratchet  42  is rotatable and hitched around the winding axis  5 .  
         [0053]     Generally speaking, the ratchet  42  is made with metal, because the frictional coefficient between metals is small, we apply rubber or other non-metallic friction wafer  44  to contact against the ratchet  42 . in the embodiment, the friction wafer  44  includes the internal friction wafer  441 , the external friction wafer  442 , the internal friction wafer  441  is made of non-metallic materials, while the external friction wafer  442  is made of wear resistant metallic materials with strong intensity.  
         [0054]     When the winding axis  5  is winding, the rocking handle  51  continuously processes progressively under the effect of the screws and threads, the winding roller  53 , the ratchet  42 , the internal friction wafer  441 , the external friction wafer  442  and the rocking handle  51  on the winding axis  5  are getting closer and closer, their frictional forces stop rotation, continue rotating the rocking handle  51  to drive the winding axis  5  to wind the pull rope  33  and then to lift the carrier  2 ; during the rotation of ratchet  42 , the claw  43  gets over the effect of the reset torsion spring  45  to move from the bottom of teeth to the top of teeth of the ratchet  42 , when the operator releasing the rocking handle  51  during winding, as the claw  43  engaging with the ratchet  42 , and at the same time, the ratchet  42  still contacts tightly with the winding roller  53  on the winding axis  5 , so under the effect of the frictional force between the ratchet  42  and the winding roller  53 , the winding axis  5  will not automatically rotate back when drawn by the pull rope  33 .  
         [0055]     When the winding axis  5  is releasing winding, the rocking handle  51  screws out reversely, the winding roller  53 , the ratchet  42 , the internal friction wafer  441  and the external friction wafer  442  separate from each other, at this time, the ratchet  42  is rotatable and hitched around the winding axis  5 , continue releasing the rocking handle  51 , the rocking handle  51  will then stress the compressed spring, which contact with the rocking handle  51  and the end cap  522  tightly respectively, when the frictional force between the compressed spring and the rocking handle  51  and the end cap  522  is great enough, the rocking handle  51  will rotate with the winding axis  5  together, continue reverse rotation, the rocking handle  51  will drive the winding axis  5  to release winding.  
         [0056]     As operating the ratchet  42  in a separative way, when the winding axis  5  is winding, the rocking handle  51  can drive the winding axis  5  to wind, and during the process, once the rocking handle  51  is released, the rocking handle  51  will not rotate back; and when the winding axis  5  is releasing winding, the rocking handle  51  can drive the winding axis  5  to release winding, thus to ensure an easy and safe operation.  
         [0057]     When the winding axis  5  is winding, as the ratchet  42  on the winding axis  5  only allow single direction rotation, thus the ratchet  42  and the winding axis  5  are under rotary retaining and connected together; when releasing the rocking handle during winding, the winding axis  5  will self lock instead of automatically rotating back when drawn by the pull rope  33 , thus to ensure the safety of the operators and prevent goods from falling as the locking device fails to lock in time.  
         [0058]     FIGS.  16  to  25  illustrate a third embodiment of a Portable Lift Hand Truck according to the present invention: each pulley of the fixed pulley block  32  and the moveable pulley block  31  is covered by pulley housing  34 , the inside diameter of each pulley housing  34  is a little more than the diameter of each roller  35  and each pulley housing  34  has two first fairleads  341  for the pull rope  33  to pass through. The pull rope  33  passes in from one first fairlead  341  and passes out from the other first fairlead  341  after passing by the pulley  35 .  
         [0059]     There is a sleeve  55  outside the winding axis  5 , the sleeve  55  is fixed to the support of the winding axis  5 , and there is a second fairlead  551  on the sleeve  55  for the pull rope  33  to pass through.  
         [0060]     The advantage is that: the pull rope  33  will not escape from the pulley  35  or the winding axis  5  when the pull rope  33  around the fixed pulley block  32 , the moveable pulley block  31  and the winding axis  5  is under lifting or loosened condition, thus to efficiently prevent the dangers arisen herefrom and troubles to reinstall pull rope  33 .  
         [0061]     Besides, FIGS.  16  to  19  illustrate another retraction device  6  in a third embodiment. The retraction device  6  includes the elastic piece  62  in the hollow tube on the chassis  1 , the elastic piece  62  is the tension spring, one end of the elastic piece  62  is fixed to the chassis  1 , and the other end of the elastic piece  62  has a towing line  63  connected to the carrier  2 , there is lead block  15  on the bottom of the chassis  1 , the towing line  63  passes round the lead block  15  and then be fixed to the bottom of the carrier  2 .  
         [0062]     There are plural projecting lugs  111  integrated on the pair of longitudinal beams  11  of the chassis  1 , there is a baffle  16  integrated on the middle of the chassis  1 , the baffle  16  spans the chassis  1  and the two ends of the baffle  16  are fixed to the two sides of the chassis  1  respectively.  
         [0063]     When working, placing the goods on the carrier  2 , and then rotating the winding handle  321  forwardly to drive the winding axis  5  to wind the pull rope  33 , under the combined action of the fixed pulley block  32  and the moveable pulley block  31 , the pull rope  33  gets over the effect of the elastic piece  62  connected to the towing line  63  to lift the carrier  2 , the carrier  2  moves upwards along the guide way  14  to the desired position; when releasing the carrier, reversely rotating the winding handle  321  to release the pull rope  33 , and the carrier  2  will be drawn by the towing line  63  and retracted to the initial position.  
         [0064]     The advantage is that: the elastic piece  62  is in the hollow tube of the chassis  1  and the towing line  63  and lead block  15  are inside the hollow tube of the chassis  1 , the space inside the hollow tube of the chassis  1  is fully used and such design is also able to drive the empty carrier  2  to the reset position, and the design is not only nice, but also practical.  
         [0065]     Besides, the elastic piece  62  can use compressed spring, the end of the compressed spring is fixed to the chassis  1  and the other end of the compressed spring is fixed to the carrier  2 ; the compressed spring can also be set in the hollow tube of a pair of longitudinal beams  11  for a nice looking.