Patent Publication Number: US-2003223808-A1

Title: Length-adjusting device for elastic cord member

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to a length-adjusting device adapted for adjustably fastening an elastic cord member to an object and, more particularly, to such a length-adjusting device, which is easy to install and inexpensive to manufacture.  
       [0003] 2. Description of the Related Art  
       [0004] Elastic cord members are springy, and intensively used in motorcycles for fastening things. Recently, elastic cord members are commonly used in exercising apparatus. When in use, an elastic cord member may be matched with a length-adjusting device so that the user can conveniently adjust the length of the elastic cord member. FIG. 1 is a perspective view of a length-adjusting device according to the prior art. FIG. 2 shows an application example of the prior art length-adjusting device. This structure of length-adjusting device  90  is comprised of a mounting block  91 , and a cord member clamp  92 . The mounting block  91  comprises two through holes  911 ,  911 ′, a hook  912  extended from the periphery, and a pin  913  pivoted to the free end of the hook  912 . By means of the hook  912  and the pin  913 , the mounting block  91  can be conveniently fastened to, for example, one handle  941  of an exercising apparatus  94 . The cord member clamp  92  is comprised of a top clamping shell  921  and a bottom clamping shell  922 . The clamping shells  921 ,  922  are detachably fastened together. When fastened together, the clamping shells  921 ,  922  define two insertion holes  923 . The elastic cord member  93  is inserted through the through holes  911 ,  911 ′, and then secured to the insertion holes  923  of the cord member clamp  921 . The cord member clamp  921  further comprises a plurality of conical teeth (not shown) formed integral with the clamping shells  921 ,  922  and adapted to stop the elastic cord member  93  from movement relative to the cord member clamp  921 . This design of length-adjusting device is still not satisfactory in function and, has drawbacks as outlined hereinafter:  
       [0005] 1. The installation of this design of length-adjusting device is complicated. When in use, the user must insert one end of the elastic cord member  93  through one through hole  911  of the mounting block  91 , and then turned into a U-turn, and then inserted through the other through hole  911 ′. When adjusted to the desired length, the main section and endpiece of the elastic cord member  93  are respectively put in between the clamping shells  921 ,  922 , and then the clamping shells  921 ,  922  are fastened together to hold down the main section and endpiece of the elastic cord member  93  in the insertion holes  931 .  
       [0006] 2. The manufacturing cost of this design of length-adjusting device is high. Because the mounting block  91  comprises two through holes  911 ,  911 ′, a hook  912 , and a pin  913  and the cord member clamp  92  is formed of a top clamping shell  921  and a bottom clamping shell  922 , the manufacturing cost of the length-adjusting device is high.  
       SUMMARY OF THE INVENTION  
       [0007] The present invention has been accomplished to provide a length-adjusting device, which eliminates the aforesaid drawbacks. It is therefore the main object of the present invention to provide a length-adjusting device, which is easy to install.  
       [0008] It is another object of the present invention to provide a length-adjusting device, which is inexpensive to manufacture.  
       [0009] To achieve these objects of the present invention, the length-adjusting device is formed of a block body for the fastening of an elastic cord member. The block body has a first tunnel, a second tunnel and a third tunnel for enabling the elastic cord member to be inserted with one end thereof through the first tunnel and then detoured and inserted through the second tunnel and then detoured and inserted through the third tunnel and extended out of the third tunnel at a distance. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010]FIG. 1 is a perspective view of a length-adjusting device according to the prior art.  
     [0011]FIG. 2 shows an application example of the prior art length-adjusting device.  
     [0012]FIG. 3 is a perspective view of a length-adjusting device according to a first embodiment of the present invention.  
     [0013]FIG. 4 is a sectional view taken along line  4 - 4  of FIG. 3.  
     [0014]FIG. 5 is a side view of the length-adjusting device according to the first embodiment of the present invention.  
     [0015]FIG. 6 is an installed view of the length-adjusting device according to the first embodiment of the present invention, showing the elastic cord member inserted through the tunnels of the block body.  
     [0016]FIG. 7 is an applied view of the present invention, showing the length-adjusting device of the first embodiment of the present invention used in an exerciser.  
     [0017]FIG. 8 is a perspective view of a length-adjusting device according to a second embodiment of the present invention.  
     [0018]FIG. 9 is a sectional view taken along line  9 - 9  of FIG. 8.  
     [0019]FIG. 10 is a longitudinal view in section of a length-adjusting device according to a third embodiment of the present invention.  
     [0020]FIG. 11 is a perspective view of a length-adjusting device according to a fourth embodiment of the present invention.  
     [0021]FIG. 12 is a sectional view taken along line  12 - 12  of FIG.  11 .  
     [0022]FIG. 13 is a longitudinal view in section of a length-adjusting device according to a fifth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0023] Referring to FIGS.  3 ˜ 5 , a length-adjusting device  10  provided by a first preferred embodiment of the present invention is shown comprising a block body  20  shaped like a circular block. The block body  20  has a first tunnel  21 , a second tunnel  22 , a third tunnel  23 , an elongated slot  24 , and a peripheral groove  25 . The first tunnel  21  and the second tunnel  22  are radially disposed at two sides of the center of the block body  20 . The pitch between the first end  211  of the first tunnel  21  and the second end  222  of the second tunnel  22  is shorter than the pitch between the second end  212  of the first tunnel  21  and the first end  221  of the second tunnel  22 , therefore the first tunnel  21  and the second tunnel  22  show a substantially V-shaped arrangement. The peripheral groove  25  is connected between the second end  212  of the first tunnel  21  and the first end  221  of the second tunnel  22 . The third tunnel  23  and the elongated slot  24  are disposed between the first tunnel  21  and the second tunnel  22  in parallel to the axis of the block body  20  (i.e., the axes of the first tunnel  21  and second tunnel  22  are on a first plane, and the axis of the third tunnel  23  is on a second plane substantially perpendicular to the first plane).  
     [0024] Referring to FIG. 6 and FIG. 4 again, the elastic cord member  30  is inserted through the first end  211  and second end  212  of the first tunnel  21 , and then extended over the peripheral groove  25 , and then turned backwards and inserted through the first end  221  and second end  222  of the second tunnel  22 , forming a first turn  31  at the peripheral groove  25 , and then turned upwards and inserted through the third tunnel  23 , forming a second turn  32 . The endpiece  33  of the elastic cord member  30  extends out of the third tunnel  23  at a predetermined distance. The first turn  31  and second turn  32  of the elastic cord member  30  produce a friction resistance when the elastic cord member stretched, keeping the block body  20  firmly secured to the elastic cord member  30 . A belt  80  is fastened to the elongated slot  24  for the gripping of the hand, or for hanging on an object. FIG. 7 shows an application example of the present invention. As illustrated, the elastic cord member  30  has one end fixedly fastened to the exerciser  85  and the other end fastened to the length-adjusting device  10 , and the player holds the belt  80  of the length-adjusting device  10  to exercise the muscles of the arms. Further, the length-adjusting device  10  can be made having a hook and a spring latch for fastening.  
     [0025] The design of the peripheral groove  25  enables the elastic cord member  30  to be received in one side of the block body  20  to maintain the sense of beauty of the length-adjusting device  10 . The peripheral groove  25  can be a straight groove connected between the first tunnel  21  and the second tunnel  22 , forming a respective turn at each of the first and second tunnels  21 ,  22  to enhance the friction resistance between the elastic cord member  30  and the block body  20 .  
     [0026] As indicated above, the length-adjusting device achieves the following advantages.  
     [0027] 1. One single block design for quick installation. Because the length-adjusting device is a single block, the user can easily fasten an elastic cord member to the length-adjusting device and conveniently adjust the elastic cord member to the desired length.  
     [0028] 2. Because the length-adjusting device is formed of a single block, the manufacturing cost of the length-adjusting device is low.  
     [0029]FIGS. 8 and 9 show a length-adjusting device according to a second preferred embodiment of the present invention. According to this embodiment, the block body  41  of the length-adjusting device  40  has a smoothly arched peripheral section  42  and a straight peripheral section  43  connected between two distal ends of the smoothly arched peripheral section  42 . Actually, the block body can be variously shaped, for example, the block body can be shaped like a square block, rectangular block, trapezoidal block, oval block, etc.  
     [0030] Further, the number of tunnels of the block body is not limited to three. FIG. 10 shows a length-adjusting device according to a third preferred embodiment of the present invention. In addition to the first, second and third tunnels  52 ,  53  and  54 , the block body  51  of the length-adjusting device  50  further comprises a fourth tunnel  55  adjacent to the third tunnel  54  for the passing and positioning of the endpiece of the elastic cord member.  
     [0031]FIGS. 11 and 12 show a length-adjusting device according to a fourth preferred embodiment of the present invention. According to this embodiment, the block body  61  of the length-adjusting device  60  is a rectangular block, and the first tunnel  62  and the third tunnel  64  are arranged in parallel and spaced from the second tunnel  63  at two sides, i.e., the longitudinal axes of the first tunnel  62 , second tunnel  63  and third tunnel  64  are disposed on one plane and approximately in parallel to one another. When inserted through the tunnels  62 ,  63 ,  64 , the elastic cord member  30  shows a substantially S-shaped profile. Further, the block body  61  comprises at least one conical tooth  65  disposed in each detour for enhancing the positioning of the elastic cord member  30  in the block body  61 .  
     [0032] In the aforesaid first embodiment of the present invention, the first tunnel and the second tunnel are disposed on a first plane, and the third tunnel is disposed on a second plane. In the aforesaid fourth embodiment of the present invention, the first, second and third tunnels are disposed on one plane. Alternatively, the block body can be made having the three tunnels respectively disposed on different planes.  
     [0033]FIG. 13 shows a length-adjusting device according to a fifth preferred embodiment of the present invention. In addition to the first, second and third tunnels  72 ,  73 ,  74 , the block body  71  of the length-adjusting device  70  further comprises a fourth tunnel  75  for the passing and positioning of the endpiece of the elastic cord member.