Abstract:
A luggage trolley comprises a dragging bracket, a retractable drawbar, and at least a wheel set on the bottom of the dragging bracket. On the dragging bracket there is a wheel-moving assembly that can be opened to the forward dragging direction and form a supporting point. The luggage trolley can be very smooth and stable when dragged because it can form a stable structure having three supporting points including the two wheels and a newly-added wheel of the moving wheel-assembly. The newly-added wheel is the pivot which bears the most weight of the luggage when the luggage inclines. It becomes the bearing support and greatly improves the mobility of the trolley when dragged and the stability of the trolley when standing.

Description:
FIELD OF THE TECHNOLOGY 
       [0001]    This application relates generally to transport trolleys and especially to a luggage trolley. 
       BACKGROUND 
       [0002]    Usually, a conventional luggage trolley employs two or four caster wheels, which is not light in weight, and not convenient to use. When using these traditional luggage trolleys, the user must hold the operative handle and tilt the trolley, including the luggage to an advancing direction so that the two wheels at the advancing direction become the center of the gravity. An upward force must be applied to grip the trolley and, at the same, time a forward force must be applied to drag the trolley. The user feels very tired after using these luggage trolleys for a long time since different forces are applied at the same time for operating the trolley. The situation may even be worse if the luggage is loaded with heavy articles. Meanwhile, the trolley is difficult to operate and may even turn over if the articles contained in the luggage are unevenly distributed. 
       SUMMARY 
       [0003]    Accordingly, an advanced trolley which is simple and convenient to operate is provided. 
         [0004]    In addition, a trolley of the aforesaid character which can be manufactured with low costs is provided. 
         [0005]    A luggage trolley comprises a dragging bracket, a retractable drawbar, and at least one wheel set on the bottom of the dragging bracket, wherein on the dragging bracket there is a wheel-moving assembly that can be opened to drag in a forward direction and form a supporting point. 
         [0006]    A luggage trolley incorporates the wheel-moving assembly which comprises a wheel shaft and a moving wheel. One end of the wheel-moving assembly is pivotally connected to the dragging bracket and can be opened to the dragging forward direction while the other end of the wheel-moving assembly is mounted with the moving wheel. 
         [0007]    A fixing assembly fixes the opening angle of the wheel-moving assembly. The fixing assembly comprises a sliding sleeve and two connecting rods. The sliding sleeve is mounted on the wheel-moving assembly and the two ends of each connecting rod respectively are pivotally connected to the sliding sleeve and the dragging bracket and can be rotated. 
         [0008]    On the wheel-moving assembly there is a location device to fix the relative position between the fixing assembly and the wheel-moving assembly. 
         [0009]    The location device is biased projection on the wheel-moving assembly. 
         [0010]    On the dragging bracket there is an opening-control device to open or pack up the wheel-moving assembly. The opening-control device comprises a rotating transverse axle radially connected to the wheel-moving assembly, wherein a block is set on the rotating transverse axle or the wheel-moving assembly, and a push key on the retractable drawbar can be used to drive the block and open the wheel-moving assembly when being pushed by a human being. 
         [0011]    The block transversely extends to connect the two ends of a rotating transverse axle. The retractable drawbar has double bars while at the bottom of the retractable drawbar a projecting push device is set in corresponding position to the block. 
         [0012]    The rotating transverse axle is eccentric and the block is set on the far end. A restorable spring is set on the other side of the block opposite to the push key. 
         [0013]    The block is set on the inner side of wheel-moving assembly. The retractable drawbar may be a single bar. At the bottom of the retractable drawbar, a projecting push device is set at corresponding positions to the block, with a bevel as the engaging interface between the block and the projecting push device. 
         [0014]    On the opposite side of the rotating transverse axle to the wheel-moving assembly, there is a projection with a restorable spring. 
         [0015]    The wheel-moving assembly comprises a wheel shaft and in the wheel shaft, a safety device is mounted. 
         [0016]    The safety device comprises a retractable lockpin radially protruding out of the wheel shaft, and a lock pole mounted inside the wheel shaft to control the lockpin by longitudinally moving. 
         [0017]    The bottom of retractable lockpin is an X-type biased device and the relative end of the lock pole is an inverse V-type structure while the two arms of an X-type biased device slides against the inverse V-type structure. 
         [0018]    On the corresponding positions of the dragging bracket and the retractable drawbar, there are anchor points to fit to each other when being mounted. 
         [0019]    The luggage trolley can be very smooth and stable when dragged because it can form a stable structure by 3 supporting points including the two wheels and a newly-added wheel, e.g., the moving wheel. The newly-added wheel is the pivot to which bears the most weight of luggage when the luggage is inclining. It becomes the bearing support and greatly improves the mobility of the trolley when dragged and the stability of the trolley when standing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is an illustration of a configuration of a trolley with luggage (showing the pack-up state of a wheel-moving assembly); 
           [0021]      FIG. 2  is an illustration of a configuration of the trolley with luggage (showing the open state of a wheel-moving assembly); 
           [0022]      FIG. 3  is an illustration of a configuration of the trolley with luggage (showing the state of being dragged); 
           [0023]      FIG. 4  is a side view of the inner structure of the trolley; 
           [0024]      FIG. 5  is a magnified view of a portion of  FIG. 4 ; 
           [0025]      FIG. 6  is an illustration of another embodiment of a trolley with luggage; 
           [0026]      FIG. 7  is an illustration of a wheel-moving assembly when being packed up; 
           [0027]      FIG. 8  and  FIG. 8-1  respectively are a connecting illustration of a rotating transverse axle and wheel shaft and a magnified view of part AA thereof; 
           [0028]      FIG. 9  and  FIG. 9-1  respectively are a solid view of a usage state as an ordinary two-wheel dragging bracket of a trolley and a magnified view of part AB thereof; 
           [0029]      FIG. 10 ,  FIG. 10-1  and  FIG. 10-2  respectively are a solid view of an open state of a wheel-moving assembly, a magnified view and a perspective view of part AC thereof; 
           [0030]      FIG. 11 ,  FIG. 11-1  respectively are an illustration of a safety device of a trolley and a magnified view of part AD thereof; 
           [0031]      FIG. 12  is an illustration of another embodiment of a trolley (showing the pack-up state of a wheel-moving assembly); 
           [0032]      FIG. 13  and  FIG. 13-1  respectively are a side view of the trolley embodiment of  FIG. 12  (used as an ordinary two-wheel structure) and a magnified view of part AE thereof; 
           [0033]      FIG. 14  and  FIG. 14-1  respectively are the side view of another embodiment of a trolley (showing the open state of a wheel-moving assembly) and the magnified view of part AF; 
           [0034]      FIG. 15  is an illustration of another embodiment of a trolley and luggage when the wheel-moving assembly is being used; 
           [0035]      FIG. 16  is an illustration of another embodiment of a trolley; 
           [0036]      FIG. 16A  is a magnified view of part AG shown in  FIG. 16 ; and 
           [0037]      FIG. 17  is an illustration of a working state of the trolley embodiment of  FIG. 16 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0038]    Various embodiments of a trolley are described with reference to the drawings, but the present invention is not restricted to the described embodiments. 
       Specified Embodiment 1 
       [0039]    As showed in  FIG. 1 , this embodiment employs a new type of dragging trolley comprising a dragging bracket  2 , a retractable drawbar  1 , and wheels  5 , as well as wheel-moving assembly  4  that is mounted on the bottom of the dragging bracket  2 . 
         [0040]    The retractable drawbar  1  is disposed at the top end of the dragging bracket in a sleeve arrangement and is retractable relative to the dragging bracket  2 . The structure making the retractable drawbar  1  extend and retract is the same as existing technology. The retractable drawbar  1  has a double-bar drawbar configuration. Luggage  6  is fixed at one side of the dragging bracket  2 . 
         [0041]    The wheel-moving assembly  4 , which is set on the side near the dragging direction of the dragging bracket  2 , comprises wheel shaft  41  and moving wheel  42  thereof. One end of the wheel shaft  41  is axially connecting to the side near dragging direction on the central beam  21  of the dragging bracket  2 , while the other end mounts with the moving wheel  42 . The moving wheel  42  can be rotated around the moving wheel axle. It also can be opened to the advancing direction of the dragging bracket  2  and forms a supporting point of the luggage (shown as  FIG. 2  and  FIG. 3 ). 
         [0042]    On the dragging bracket  2  there is mounted a supporting assembly  3  to fix the opening angle of the wheel-moving assembly  4 . In this specified embodiment, the supporting assembly  3  comprises two connecting rods  31  and a sliding sleeve  32 . The sliding sleeve  32  is slidably received on the wheel shaft  41  of the wheel-moving assembly  4  and is free to slide along with the wheel shaft  41 . The two connecting rods  31  are mounted at one end to a little opening. One end of each connecting rod is connected to the sliding sleeve  32 , the other end is connected to a mounting hole on the bottom of the wheel shaft on the dragging bracket  2 . The connecting rods can be freely rotated. When the wheel-moving assembly  4  is positioned closest near the dragging bracket  2 , the connecting rods  31  are also positioned close to the dragging bracket  2  and the sliding sleeve is on the top of the wheel shaft  41 . As shown in  FIG. 4  and  FIG. 5 , upon pivoting the wheel shaft  41  away from the dragging bracket  2 , the sliding sleeve  32  slides down along the wheel shaft  41 , driving the connecting rods  31  away from the dragging bracket  2 , until the angle between the wheel-moving assembly  4  and the connecting rod  31  is a stable 90 degrees. A location device  411  is positioned on the body of the wheel shaft  41  to fix them. The location device  411  can be set as a flexible bevel convexity on the wheel shaft  41 . After the sliding sleeve  32  slides across this location, the spring in the location device  411  will restore to fix the location of sliding sleeve  32 . 
         [0043]    The supporting assembly  3  is preferably a stay bar with one end connecting the bottom end of the wheel shaft  41  of the dragging bracket  2  and the other end being free to rotate. It works when fitted with the location device of wheel-moving assembly  4  (such as a location hole). After the wheel-moving assembly  4  is opened to the advancing direction of dragging bracket  2 , the stay bar is turned and its working end is made to fit in the location device of wheel-moving assembly  4 . Then the wheel-moving assembly is fixed in an opening state. 
       Specified Embodiment 2 
       [0044]    As shown in  FIG. 6 , the trolley of this embodiment comprises a dragging bracket  2 A, a retractable drawbar  1 A, and wheels  5 , as well as a wheel-moving assembly  4  that is disposed on the bottom of dragging bracket  2 A. 
         [0045]    The retractable drawbar  1 A is mounted on the upper end of dragging bracket  2 A in a sleeve arrangement and can slide along the dragging bracket  2 A. This retractable drawbar  1 A employs a single beam drawbar. The dragging bracket  2 A is embedded in the reverse side of the luggage  6 . 
         [0046]    In the same manner as embodiment 1, the wheel-moving assembly  4 , which is mounted on the dragging bracket  2 A in the side of the advancing direction, comprises a wheel shaft  41  and a wheel  42 . One end of wheel shaft  41  is hinged to the dragging bracket  2 A on the transverse beam in the advancing direction while the other end is mounted with the wheel  42 . The wheel  42  can rotate around the axle and is opened in the advancing direction of the dragging bracket  2 A to form a supporting point. On the dragging bracket  2 A a supporting assembly  3  is mounted to fix the opening angle of the wheel-moving assembly  4 , which comprises two connecting rods  31  and one sliding sleeve  32 . When the wheel-moving assembly  4  is positioned close to the dragging bracket, the connecting rod  31  is also positioned close to the dragging bracket while the sliding sleeve  32  is located on the top part of wheel shaft  41 . When turning the wheel shaft  41  away from the dragging bracket  2 A, the sliding sleeve  32  slides down along the wheel shaft  41  driving the connecting rods  31  away from the dragging bracket  2 A, until the angle between the wheel shaft  41  and the connecting rod  31  is 90 degrees. 
       Specified Embodiment 3 
       [0047]    As shown in  FIG. 7 , the improved trolley comprises a dragging bracket  2 , a retractable drawbar  1 , wheels  5  mounted on the bottom of dragging bracket  2 , a wheel-moving assembly, a sliding-rod assembly and control equipment for controlling the open or close position of the trolley. 
         [0048]    The retractable drawbar  1  has a double-pole drawbar configuration. On each side of the dragging bracket  2  there is a groove to receive the retractable drawbar  1  in a sleeve arrangement. The structure to fix the position of the retractable drawbar  1  is conventional. For example, a safety and location device  101  is mounted to control the extension and retraction of a protrusion on the retractable drawbar  1 , so that the retractable drawbar  1  can slide along the dragging bracket  2  and be fixed to a given position, as detailed described above. The luggage is fixed on one side of the dragging bracket  2 . 
         [0049]    A wheel-moving assembly which comprises a wheel shaft  41  and a wheel  42 , is set on the side of the pulling direction of dragging bracket  2 . One end of wheel shaft  41  is connected to a transverse beam  21  on the central part of dragging bracket  2  while the other end is mounted with the wheel  42 . The assembly can be opened toward the advancing direction of the dragging bracket  2  and form a supporting point (shown in  FIG. 4 ). 
         [0050]    The control equipment comprises: the transverse beam  21  with its block  16   b  and a push device  104  on the end of retractable drawbar  1  extending and facing the block position. The transverse beam  21  is connected with the dragging bracket  2  through a shaft  16   a , shown in  FIG. 8  and  FIG. 8-1 , in the middle of which is axially mounted with the wheel-moving assembly. The two ends of the transverse beam  21  extend to form two blocks  16   b . It is preferred that the transverse beam  21  is a partially centered rotating shaft and the block  16   b  is mounted on the apocentric part. This structure makes the center of gravity of the transverse beam  21  lean to the inner part and makes the wheel-moving assembly easier to be opened while also being much easier to pack up by under the force of gravity. On the opposite side of block  16   b  and push device  104  there is a restorable spring  16   c . When the retractable bracket  1  rises up to a fore-set position, the push device  104  will withstand the block  16   b . Upon continuing rising, the push device  104  drives the block  16   b  and causes the transverse beam  21  to rotate clockwise to open the wheel-moving assembly. 
         [0051]    The sliding-rod assembly comprises two connecting rods  31  and a sliding sleeve  32 . The sliding sleeve  32  surrounds the wheel shaft  41  of wheel-moving assembly and can slide freely along the wheel shaft  41 . The two connecting rods  31  are mounted with one side wide. One end of each connecting rod connects to the sliding sleeve  32  while the other end pivotally connects to the bottom bracket  113  of dragging bracket  2 . 
         [0052]    In addition, in the wheel shaft a safety device is mounted, as shown in  FIG. 11  and  FIG. 11-1 . The safety device comprises a retractable lockpin  112  axially extending out of the wheel shaft  41  and a lock rod  14   a  that is set in the wheel shaft  41  for moving and controlling the retractable lockpin  112  by longitudinal movement. The top part of the lock rod  14   a  extends through a transverse hole  16   d  on the transverse beam  21 . The bottom end of lock rod  14   a  is an inverse V-type structure. On the bottom end of retractable lockpin  112 , an X-type spring loaded device  14   b  is mounted. The two arms of the X-type spring loaded device  14   b  are mounted into the inner wall of the inverse V-type structure of lock rod  14   a  and are slidable against the inverse V-type structure. The lock rod  14   a  normally compresses the X-type spring loaded device  14   b  and retracts the retractable lockpin  112 . When the wheel-moving assembly is opened, the sliding sleeve  32  moves to the position of retractable lockpin  112  and takes the lock rod  14   a  up to release the X-type spring loaded device  14   b . The X-type spring loaded device  14   b  pushes the retractable lockpin  112  out of the wheel shaft  41  and stops the sliding sleeve  32 . 
         [0053]    On the dragging bracket  2  a few location holes are positioned to receive a location projection on the retractable drawbar  1  so that a different positional state is achieved and the user can adjust to get a most comfortable one. 
         [0054]    As  FIG. 1  shows, when the wheel-moving assembly is packed up, the location projection  22   a  of retractable drawbar  1  will mate with a location hole  23   a . When the location projection  22   a  mates with another location hole  23   b , as shown as  FIG. 9  and  FIG. 9-1 , the wheel-moving assembly is still packed up and the whole trolley can be used as a traditional two-wheel system. When the location projection  22   a  mates with the third location hole  23   c , as shown as  FIG. 10 ,  FIG. 10-1  and  FIG. 10-2 , the push device  104  will drive the block  16   b  and cause the transverse beam  21  to clockwise rotate so that the wheel-moving assembly is opened. 
         [0055]    After usage, pushing the safety and location device  101  and vertically pressing down the retractable drawbar  1  at the same time will result in the push device  104  releasing the block  16   b . Because of the force of restorable spring  16   c  and the gravity of wheel-moving assembly, the wheel-moving assembly will rotate counterclockwise until at last it goes back to a groove on a downward beam  110 . 
       Specified Embodiment 4 
       [0056]    As  FIG. 12  shows, this embodiment is adapted to be the trolley for another kind of structure. The trolley comprises a dragging bracket  2 , a retractable drawbar  1 , a wheel  5  mounted on the bottom of dragging bracket  2 , a wheel-moving assembly, a sliding-rod assembly and a control equipment for controlling the open or close position of the trolley. The luggage  118  is mounted on the trolley as shown in  FIG. 15 . 
         [0057]    The retractable drawbar  1  has a single-pole drawbar configuration. In the center of dragging bracket  2  is a groove to release the retractable drawbar  1  in a sleeve-relationship and let the retractable drawbar extend or retract. The structure to fix the retractable drawbar  1  is conventional. For example, a safety and location device  101  is mounted to control the extension and retraction of a location projection on the retractable drawbar  1 . The retractable drawbar  1  can slide along the dragging bracket  2  and be fixed at a given position, as detailed described above. 
         [0058]    The wheel-moving assembly which comprises a wheel shaft  41  and a wheel  42  is the same as shown in embodiment 3 and is positioned on the side of the pulling direction of dragging bracket  2 . One end of wheel shaft  41  connects to a transverse beam  21  on the central part of dragging bracket  2  while the other end is mounted with the wheel  42 . They can be opened to the advancing direction of the dragging bracket  2  and form a supporting point. 
         [0059]    The sliding-rod assembly, comprising two connecting rods and a sliding sleeve, is also the same as embodiment 3. The arrangement of the control equipment for controlling the open or close position is changed because the retractable drawbar  1  assumes a single-pole structure. 
         [0060]    As shown in  FIG. 13 ,  FIG. 13-1 ,  FIG. 14  and  FIG. 14-1 , a block  28   a  is positioned on the inner side of a wheel shaft adjacent the transverse beam  21 . A push device  104   a  positioned on the end of retractable drawbar  1  extends from and faces the block  28   a . The block  28   a  and the push device  104   a  have a bevel as the engaging interface with each other. When the retractable drawbar  1  rises up to some position, the push device  104   a  will withstand the block  28   a . When the retractable drawbar  1  continues to rise up, it will drive the block and force the transverse beam  21  clockwise rotate to cause the wheel-moving assembly to open. On the transverse beam  21  opposite to the side connecting the wheel-moving assembly a projection  16   e  with a restorable spring  16   c  is preferably mounted. 
         [0061]    Similar with the specification in the above embodiments, on the dragging bracket  2  there are a few location holes  23   a ,  23   b ,  23   c  and a location projection  22   a  is disposed on the retractable drawbar  1 . Different pull states are formed by the location projection being mated to different location holes. 
         [0062]    The operation process of this embodiment is the same as embodiment 3 above and need not be described further. 
       Specified Embodiment 5 
       [0063]    With reference to  FIG. 16  and  FIG. 16A , a principal difference between this embodiment and those previously described is that under the push device  104 , a stop device  105  is positioned on the bottom end of the retractable drawbar  1 . Correspondingly, a talus  106  is positioned on the connecting end of one of the connecting rods  31  to the dragging bracket  2 . This talus  106  engages the stop device  105  to stop the connecting rods  31  from opening. 
         [0064]    When the retractable drawbar  1  is raised the stop device  105  will release the talus  106 , shown in  FIG. 17 . Then, the connecting rods  31  can be opened by the push device  104 . The trolley otherwise functions in the same manner as described above for the other embodiments.