Abstract:
A handle assembly of luggage comprises a handle grip with a push button, two first sliding tubes, at least one pair of second sliding tubes, two support tubes, two first locking means each provided below each first sliding tube, at least one pair of second locking means each provided below each second sliding tube, and a flexible steel cable attached between handle grip and first locking means. This ensures a fully extended handle, a significant increase of the ratio of extendible maximum length to retractable minimum length of handle, and the retracted handle grip rested on the bezel without any gap.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a retractable handle for a locking device for a retractable handle of wheeled luggage and more particularly to such a locking device with improved characteristics. 
     2. Description of Related Art 
     Typically, a single locking device is provided in the retractable handle for controlling the handle in a retracted position and an extended position. That is, the retractable handle may be extended to a maximum length when towing on the ground by traveler as well as retracted into a minimum length (i.e., rested on the top of luggage) appropriate for stowage or transport. It is known that luggage equipped with a retractable handle is very popular among travelers. Thus many types of luggage with retractable handle are commercially available in which each type of luggage mounted with a unique locking device. For example, the single locking device comprises wedge members, springs, lock blocks (or pins), supporting members, detents, and connecting wires. 
     Various designs of locking devices have been found in a search as follows: U.S. Pat. No. 5,581,846 entitled “Controlling Handle Structure for Full Rods of a Luggage”, and U.S. Pat. No. 5,628,088 entitled “Multistage Adjustable Device for Trunk Bracket”. As to the complex retractable handle with multiple retaining slots, various designs thereof also have been found in a search as follows: Taiwanese Patent Published No. 337,100 entitled “Improved Retractable Handle of Luggage”; No. 362,404 entitled “Activation Mechanism for Retractable Handle with Multiple Retaining Slots of Luggage”; and No. 368,815 entitled “Improved Activation Mechanism for Retractable Handle with Multiple Retaining Slots of Luggage”. But these are unsatisfactory for the purpose for which the invention is concerned for the following reasons: 
     1. Complex in structure. 
     2. Susceptible to breakdown. 
     3. Time consuming in assembly. 
     4. A horizontal component force is applied on the slope because connecting wires, detents, and wedges interact with one another when user presses on the push button to activate the locking mechanism through the connecting wires. This horizontal component force may control the activation of lock blocks (or pins) and detents. However, an undesirable gap still exists between a fully retracted handle and the bezel. This is a significant drawback. 
     5. A horizontal component force is applied on the slope when lock blocks (or pins) are activated by slanted guide groove. This causes additional drawbacks in addition to those described above. In detail, the ratio of extendible maximum length to retractable minimum length is significantly lowered due to the implementation of multiple-segment longitudinal slanted guide groove. This limits the effective length of extended handle. Further, it has the disadvantages of complex in structure, difficult to adjust the assembly, low yield of finished product, and higher manufacturing cost. Thus improvement is desirable. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a locking device for handle assembly for significantly increasing the ratio of extendible maximum length to retractable minimum length of handle such that a predetermined extendible length is achievable. 
     It is another object of the present invention to provide a locking device for handle assembly wherein second locking device secures to the bottom of the second sliding tube. The second locking device has three members at most. Further, only a snapping is required to finish the assembly of second locking device and second sliding tube without any fastener. This second locking device has the advantages of simple in structure, quick assembly, and durable. 
     It is still another object of the present invention to provide a locking device for handle assembly wherein lock member of first locking device is provided at the bottom of first housing of the first locking device capable of directly moving into the lock hole of the second locking device so as to cause lock pin of the second locking device to become disengaged. There is no horizontal component force created on the slope as occurred in the prior art because the lock member of the first locking device directly inserts into the lock hole of second locking device as well as first locking device and second locking device are engaged in a planar surface. This ensures that there is no gap between the first and second locking devices such that the handle grip of the fully retracted handle may rest on the bezel. 
     To achieve the above and other objects, the present invention provides a locking device for handle assembly comprising: a first sliding tube; a first locking device detachably attached to the bottom of the first sliding tube; a second sliding tube for allowing the first sliding tube to slidingly move therein having a hole; a second locking device detachably attached to the bottom of the second sliding tube; a support tube for allowing the second sliding tube to slidingly move therein having a hole; and a first connecting means connected between a push button and the first locking device. 
     Whereby the handle is retracted when the push button is not pressed, the first sliding tube is received in the second sliding tube and the second sliding tube is received in the support tube, the projection of the first locking device is engaged with the lower hole of the second sliding tube, the bottom of the first locking device is biased against the top of the sliding block of the second locking device so as to move the lock member of the first locking device into the lock hole of the second locking device to cause the lock pin of the second locking device to retract into the support tube, whereby the handle is locked in a retracted position. 
     The push button is pressed. Then handle is pulled upward to cause the first locking device to move up so as to move the lock pin of the first locking means into lower hole of the second sliding tube. Grasp handle grip to pull first sliding tube upward for separating the lock member on the bottom of first locking device from lock hole of the second locking device. Then second locking device moves up as the second sliding tube and first sliding tube move up together until the second lock pin comes into contact with upper hole of the support tube and locks therein. Now handle is in a fully extended position for allowing luggage to be towed along the ground. 
    
    
     The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded view of a locking device for handle assembly of wheeled luggage of the invention; 
     FIG. 2 is a greatly enlarged fragmentary view showing the first and second locking devices of FIG. 1; 
     FIG. 3 is similar to FIG. 2 showing the lock block of first locking device; 
     FIG. 4 is similar to FIG. 2 showing the lock block of second locking device; 
     FIGS. 5A and 5B are first and second sectional views of first and second locking devices where handle is fully extended; 
     FIGS. 6A and 6B are first and second sectional views of first and second locking devices where second locking device is pressed by first locking device and handle is being retracted; and 
     FIGS. 7A and 7B are first and second sectional views of first and second locking devices where handle is retracted to its lowest position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1-4, there is shown a locking device for handle assembly of wheeled luggage constructed in accordance with the invention wherein handle assembly is provided on the back of luggage with a handle grip (not shown) received in a bezel on top of luggage. 
     Note that because the handle system is bilaterally symmetrical so that description of one side serves to describe the entirety. Thus the handle system of the invention comprises: a first sliding tube  10  having a lower hole  13  and an upper hole  12  attached to one end of handle grip by a known fastener; a first locking device  20  detachably attached to the bottom of first sliding tube  10 ; a second sliding tube  40  for allowing first sliding tube  10  to slidingly move therein having a top and lower holes  43  and  44  on a first side, an apertures  42  on first side, and a pin hole  45  on a second side; a first sleeve member  30  provided on the top of second sliding tube  40  having two detents  32  provided on two opposing sides matingly engaged with apertures  42  of second sliding tube  40 ; a second locking device  50  detachably attached to pin hole  45  of the second sliding tube  40  by a projection  513 ; a support tube  70  for allowing second sliding tube  40  to slidingly move therein having a top and lower holes  73  and  74  on a first and third sides, two apertures  72  on a second and third sides; and a second sleeve member  60  provided on the top of support tube  70  having two detents  62  provided on two opposing sides matingly engaged with apertures  72  of support tube  70 . 
     The first locking device  20  comprises a first housing  21  having an upper portion  210  with a guide groove  212  and a pin hole  213  such that pin  14  may insert through lower hole  13  of first sliding tube  10  and pin hole  213  to secure first locking device  20  and first sliding tube  10  together; and a lower portion  214  with a cavity  215  (FIG.  2 ); a spring  23  provided in the cavity  215  of first housing  21 ; a lock block  24  provided in the cavity  215  of first housing  21  having a projection  240  on a first side, an aperture  241  on a second side, and an opening  245  in communication with the aperture  241 ; a lock member  217  provided on the bottom of first housing  21 ; and a flexible steel cable  22  having an enlargement on one end (not shown) being secured to handle grip and an enlargement  221  on the other end being secured in the opening  245  through the guide groove  212 , cavity  215  (FIG.  2 ), and aperture  241  such that a pressing of the push button may be transmitted to first locking device  20  through the movement of flexible steel cable  22 . 
     The second locking device  50  comprises a second housing  51 , spring  52 , and second lock block  53  wherein the upper portion of the second housing  51  having a plurality of slots  516 , two opposing recesses  511 , and a lock hole  515  wherein a projection  513  is protruded inwardly on two opposite inner surfaces of flexible member  512  formed therebetween slots  516 , the projection  513  may engage with pin hole  45  of second sliding tube  40 ; the lower portion of the second housing  51  having a cavity  514  for receiving the second lock block  53  being in communication with lock hole  515  in the recess  511 ; and a projection  533  is protruded on one end of second lock block  53  for putting spring  52  thereon and a lock pin  531  is protruded on the other end of second lock block  53 . 
     The following is a description of the operation of handle assembly. 
     Referring to FIGS. 1-7, handle is retracted when push button (not shown) is not pressed (FIGS.  7 A and  7 B). First sliding tube  10  is received in second sliding tube  40  and second sliding tube  40  is received in support tube  70 . Projection  240  is biased by spring  23  to engage with lower hole  44  of second sliding tube  40  and lower hole  74  of the support tube  70 . The lock member  217  at the bottom of the first locking device  20  is biased against the lock hole  515  of the second locking device  50  so as to retract the lock block  53  of the second locking device  50  into the support tube  70 , whereby the handle is locked in a retracted position. 
     The push button is pressed (FIGS.  6 A and  6 B). Then handle is pulled upward. That is, flexible steel cable  22  of the first locking device  20  is moved up so as to bias spring  23  of the first locking device  20 . Further, lower hole  44  of projection  240  of lock block  24  clears lower hole  44  of second sliding tube  40  and lower hole  74  of support tube  70  (FIG.  6 A). As such, grasp handle grip to pull first sliding tube  10  upward for separating the lock member  217  at the bottom of first locking device  20  from lock hole  515  of the second locking device  50 . Then lock block  53  of the second locking device  50  retract into the upper hole  73  of support tube  70  and secured therein (FIGS.  7 A and  7 B). Once first sliding tube  10  is pulled up to cause projection  240  of lock block  24  of first locking device  20  to come into upper hole  43  of the second sliding tube  40  to lock therein (FIGS.  5 A and  5 B). Now handle is in a fully extended position for allowing luggage to be towed along the ground. To the contrary, press push button to retract handle which in turn causes pin  240  of lock block  24  attached to cable  22  to escape engagement with upper hole  43  of second sliding tube  40 . Whereby first sliding tube  10  may receive within second sliding tube  40  until lock member  217  at the bottom of first locking device  20  comes into contact with the lock hole  515  of the second locking device  50 . This causes lock pin  53  of second locking device  50  to clear upper hole  73  of support tube  70  (FIGS.  6 A and  6 B). Pin  240  of the lock block  24  of the first locking device  20  clears upper hole  43  of second sliding tube  40  when push button is pressed again. Then first sliding tube  10  may receive in second sliding tube  40  and second sliding tube  40  may receive in support tube  70 . Now the handle is fully retracted (FIGS.  7 A and  7 B). 
     Note that the first locking device  20  is a master device and second locking device  50  is a slave one. As such, the number of second locking device  50  may be added in other embodiments. Further, the number of second sliding tube  40  with a number of second locking device  50  having a lock member  217  at the bottom of second locking device  50  (except the lowest one) may be added too. As a result, a handle assembly with multiple locking devices and a plurality of constituent tubes are carried out, thereby enabling handle to extend and lock in one of a plurality of selective positions thereof. 
     While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.