Patent Publication Number: US-6339863-B1

Title: Multi-step positioning device of trunk pull rod

Description:
FIELD OF THE INVENTION 
     The present invention relates to a multi-step positioning device of a trunk pull rod, which is especially suitable to a pull rod fixing means being adjusted steplessly. 
     BACKGROUND OF THE INVENTION 
     Traveling for business or other purposes is prevailed currently, and thus trunks becomes a required tool in traveling. Telescopic pull rods are important components in the design of a trunk, which can provide great convenience to the travelers. Since the height of everyone is different, while it is preferred that the trunk is pulled by an angle of 45 degrees. In order to meet various demands, two sectional or multiple sectional pull rods are preferred and are widely used. Rods with two sections and one operation step is generally used in the design of trunks. Namely, after the upper section of the pull rod is pulled out, only the lower end of the upper sectional rod and the upper end of the lower sectional rod is positioned. The use of each sections of the rods is not well designed. There are some difference according to the height of the trunk. Therefore, a three sectional rod or a four sectional rod is designed. However, the operation of these multi-sectional rod is not preferred since it can not be fine adjusted. Therefore, a multi-sectional or stepless structure is designed. Furthermore, the positioning of the two sectional rod is not confined in a single position. Many positions serves to position the rod. Even every position is usable. The positions for positioning is conventionally installed with continuous holes. However, this will deteriorate the outlook, and weak the structure. In another design, the positioning structure is installed in the rod. FIG. 7 shows a prior art structure. A positioning piece  1  is installed in the outer rod. The positioning piece  1  is installed with a bank of positioning holes  11  for achieving the object of multiple step adjustment for satisfying the requirement of the user. As shown in the figure, the positioning piece is necessary to be installed in the rod, therefore, a buckling structure is installed in the outer rod  2 , in which a pair of inward protruding strips  11  are used. Although the shape of the outer rod  2  has a long elliptic shape, the inner rod has a square shape, and therefore, the visual feeling is effected. Another, the outer rod is a rectangular rod, while the inner rod is a square rod, but this is not good in visual feeling, since square rod looks very bulky. Thus, it is not met the requirement of compactness and it has many defects. Besides, a pull rod adjusting means of gears and racks is designed, wherein the gear must be adjusted precisely for positioning. It is inconvenient to the user. Furthermore, the whole structure is heavy and is almost not used commercially. An adjusting rod of teeth block and rack is designed, further. Although it has the advantages of steplessness, the application is limited. Too many adjustments cause the user not to select it properly. However, from the experiences of the applicant, there are a great extent in the design of the pull rod to satisfy the requirement of consumers. 
     SUMMARY OF THE INVENTION 
     Accordingly, the primary object of the present invention is to provide a multi-step positioning device of a trunk pull rod for using the space of the pull rod more efficiency so that the original two rod types are converted to a multiple rod type. Furthermore, elliptic rods are used instead of the conventional square rods. By the space between inner and outer rods to clamp the porous piece, the shape of the porous piece is formed as cambered rod for using space sufficient. Besides, the spring buckling buckling device is used to be buckled with the porous piece. Therefore, most of the requirement in use is satisfied. Moreover, the porous piece of the present invention is matched with a handle to be adjusted in positions so that the whole structure is more convenient. 
     Another object of the present invention is to provide a multi-step positioning device of a trunk pull rod, which can be used in the adjustment of a third sectional rod. Each section is used in an optimum condition. Each rod is retained in a specific shape for saving space. 
     In the present invention, A multi-step positioning device of a trunk pull rod has a pair of pull rods at two sides thereof. Each pull rod has an inner upper rod and an outer lower rod therein. The rod body has two sides of round arc shapes. After engaging the round arc portions of the two rods are formed with gaps. Porous pieces are placed in the gaps. The porous piece passes through the outer lower rod. The upper end of the outer lower rod is connected to an upper rod sleeve. Protruding buckles at two sides of the upper rod sleeve buckles with the buckling holes with respect to the outer lower rod. The lower end of the inner upper rod is connected to a lower rod sleeve. The slender end of the lower rod sleeve passes through the inner upper rod. The enlarged end portion has a part identical to the inner upper rod for being engaged with the porous piece. The enlarged end portion has a part having an inner diameter identical to that of the outer lower rod for being passing through the outer lower rod. The middle rod sleeve has a sliding groove at the lateral surface thereof for being inserted by a sliding block and a spring. The sliding block is connected to a driving piece. The driving piece passes through the inner upper rod to be connected to the pull piece of the handle. 
     The various objects and advantages of the present invention will be more readily understood from the following detailed description when reading in conjunction with the appended drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the present invention. 
     FIG. 2 is an exploded perspective view of the present invention. 
     FIG. 3 is a partial cross sectional view showing that the present invention is not moved. 
     FIG. 4 is a partial cross sectional view of FIG. 3 wherein the sliding piece is pressed. 
     FIG. 5 is a partial cross sectional view showing the pull rod in FIG. 3 being moved. 
     FIG. 6 is a cross sectional view along line A—A of FIG.  5 . 
     FIG. 7 is a perspective view of a prior art design. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIGS. 1 to  6  a multi-step positioning device of a trunk pull rod of the present invention is illustrated therein. The multi-step positioning device of a trunk pull rod has a pair of pull rods  3  installed towards the rear of the trunk. A handle  5  is connected between the two pull rods  3  includes an inner upper rod  31  and then outer lower rod  32 . The rod body of the pull rod  3  has two sides with a long elliptic shape. The round arc portions of the two rods  31  and  32  are engaged with one another, and thus a gap  30  is formed therebetween. A porous piece  34  is placed in the gap  30  at one or two sides. The porous piece  34  is fixed in the outer lower rod  32  and has a long cambered strip shape. A plurality of holes arranged in spaced manner are formed on the porous piece  34 . The upper end of the porous piece  34  bears against the lower end of the upper sleeve  36 , while the lower end of the porous piece  34  is formed with a lower inner fixing hole  59 . An outer fixing hole  60  is formed at the lower end of the outer lower rod  32 . A short pin  6  is inserted through the lower outer fixing hole  60  and the lower inner fixing hole  59  so that the object of fixing the porous piece  34  is achieved. A plug  7  is inserted in the outer lower rod  32 . The lower end of the plug  7  near the porous piece  34  is formed with a round groove  71  for engaging the porous piece  34 , and the short pin  6  inserts into the transversal hole  72  of the plug  7 . Therefore, the porous piece  34  is fixed. The cross section of the porous piece  34  can have a round arc shape, a polygonal shape, or another shape such as a round body with two parallel sides. 
     The upper end of the outer lower rod  32  is connected to the upper rod sleeve  36 . Each of the two sides of the upper rod sleeve  36  has a respective protruded buckle  37  for buckling the outer lower rod  32  with respect to a buckling hole  38 . The top  39  of the upper rod sleeve  39  is buckled in the top end of the outer lower rod  32 . The outer lower rod  32  has an upper end connected to an upper rod sleeve  36 . Two sides of the upper rod sleeves  36  each have a protruded buckle  37  for being buckled to the buckling hole  38  with respect to the outer lower rod  32 . The upper rod sleeve  36  has a top edge  39  the lower edge of which is buckled to the top surface of a middle tube  32 . 
     The lower end of the inner upper rod  31  is connected to the middle rod sleeve  40 . The slender end portion of the middle rod sleeve  40  passes through the inner upper rod  31 , and part of the enlarged end portion  42  thereof has an outer diameter identical to that of the inner upper rod  31 , part of that portion has an inner diameter identical to that of the outer lower rod  32  and passes through the outer lower rod  32 . The inner top surface of the middle rod sleeve  40  is formed with a through hole  43  for being inserted by a driving piece  52 . One end of the driving piece  52  is connected to a sliding piece  45 . The driving piece  53  passes through the inner upper rod  31  to be connected to a pull piece  51  on the handle  5 . The pull piece  51  is driven by a pressable piece  50 , or the pull piece  51  can be pulled directly. At least one end hole  44  of a sliding groove  49  is installed on enlarged portion  42  of the middle rod sleeve  40  facing the porous piece  34 . Each end hole  44  is passed by the buckling end  46  of the sliding block  45 . The buckling end  46  slides out of the end hole  44  of the middle rod sleeve  40  to be embedded in the hole  35  of the porous piece  34 , and then is buckled by the sliding block  45  so to position the two rods  31  and  32  to be motionless. If the buckling end  46  slides back to the end hole  44  of the middle rod sleeve  40 , then the position of the rods  31  and  32  is released and thus, each of rods  31  and  32  may move freely. A groove seat  56  in formed at one lateral surface of the sliding block  45  for fixing a fixing head  57  which is one end of the pull piece  51 . After the pull piece  51  passes through the sliding block  45 , it directly passes through one arc portion  58  for being formed as a rectangular bending to extend upwards to pass through the through hole  43 . 
     A pin hole  53  is installed near the lower end of the inner upper rod  31  . A fixing hole  47  is installed in the middle rod sleeve  40 . A pin  55  passes through the pin hole  53  to fix with the fixing hole  47  of the middle rod sleeve  40 . The middle rod sleeve  40  does not separate from the inner upper rod  31 . The movement of the middle rod sleeve  40  is completely driven by the inner upper rod  31 . Since the sliding block  45  of the present invention only provides an application of pulling upwards, a spring is arranged at one side of the sliding block  45 . In the pulling upward application shown in FIG. 4, a compressible spring  54  is installed between the sliding block  45  and the inner lateral surface of the middle rod sleeve  40 . 
     In summary in the present invention, a porous piece is installed between the elliptic rods to match with the fixing of the middle rod sleeve and the upper rod sleeve. If the porous piece is not very long, it can be combined with the middle rod sleeve. Then, the buckling end moves in the through hole of the middle rod sleeve. The driving piece connected to the sliding block serves to control the moving out or restoring of the buckling end. Because the handle has many different structures, the details will not be described herein. It is appreciated that the present invention uses a minimum volume and rods to complete the assembly of the present invention. The assembly work is easy and simple. It is suitable in pulling up and pushing down process. 
     Although the present invention has been described with reference to the preferred embodiments, it will be understood that the invention is not limited to the details described thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.