Patent Publication Number: US-8967170-B1

Title: Adjustable positioning structure for a walking stick

Description:
FIELD OF THE INVENTION 
     The present invent relates to a walking stick, and more particularly to an adjustable positioning structure for a walking stick which is used to adjust a length of the walking stick easily. 
     BACKGROUND OF THE INVENTION 
     With reference to  FIGS. 13 and 14 , a conventional walking stick  60  contains a first rod  61 , a second rod  62 , and an adjustable position structure  70  defined between the first rod  61  and the second rod  62 . The adjustable positioning structure  70  includes a fitting post  71  and an expanding member  72 . The fitting post  71  is inserted into and retained with the second rod  62  and has an external screwing section  711  formed around an outer wall thereof, and the expending member  72  is screwed with the external screwing section  711  of the fitting post  71  and has a resilient retaining paw  721  fixed on a bottom end thereof. In addition, the fitting post  71  is further fitted into a conical holder  80  and has a support portion  712  for contacting with the conical holder  80 , wherein the conical holder  80  is obliquely biased against the resilient retaining paw  721 , such that the resilient retaining paw  721  of the expending member  72  expends outwardly to engage with an inner wall of the first rod  61 . As desiring to adjust a length of the walking stick  60 , the second rod  63  is rotated by a user so as to drive the fitting post  71  and the conical holder  80  to rotate, and the external screwing section  711  of the fitting post  71  and the expending member  72  are also driven to rotate, such that the expending member  72  engages with or disengage from the conical holder  80 , thus adjusting the length of the walking stick. 
     However, such a conventional walking stick has the following disadvantages: 
     1. The expending member  80  is expended by the conical holder  80  after rotating the fitting post  71 , such that the resilient retaining paw  721  of the expending member  72  engages with the inner wall of the first rod  61 . As the user intends to engage the retaining paw  721  of the expending member  72  with the inner wall of the first rod  61  more tightly, more force is exerted on the fitting post  71  by the user so that the fitting post  71  presses the expending member  72  forcefully, thus causing a laborious operation. Moreover, when exerting weight on the first rod  61 , the expending member  72  engages with the external screwing section  711  of the fitting post  71  overly, hence an operation of the expending member  71  and the fitting post  71  is stuck. 
     2. The external screwing section  711  of the fitting post  71  and the expending member  72  are rotated to adjust the length of the walking stick, and an outer surface of the second rod  62  is too smooth to grip the second rod  62  securely. Furthermore, the length of the walking stick is adjusted slowly and troublesomely by rotating the second rod  62 . 
     3. The resilient retaining paw  721  is made of plastic material and is applied to engage with the inner wall of the first rod  61 , so a friction resistance between resilient retaining paw  721  and the inner wall of the first rod  61  is small, the resilient retaining paw  721  cannot engage with the inner wall of the first rod  61  securely. 
     The present invention has arisen to mitigate and/or obviate the afore-described disadvantages. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide an adjustable positioning structure for a walking stick which is used to adjust a length of the walking stick easily. 
     Further object of the present invention is to provide an adjustable positioning structure for a walking stick by which a friction resistance between a first screwing section and a resilient loop is increased to enhance support safety. 
     Another object of the present invention is to provide an adjustable positioning structure for a walking stick which positions the walking stick securely. 
     To obtain the above objective, an adjustable positioning structure for a walking stick provided by the present invention contains: an outer rod, an inner rod, an actuation post, a pushing, and an expending member. 
     The outer rod includes a griping head disposed on a first end thereof and a limiting sleeve mounted on a second end thereof, the limiting sleeve has a shoulder formed on an inner wall thereof, and the outer rod also includes a first screwing section defined around an inner wall thereof. 
     The inner rod includes an anti-slip pad fixed on a first end thereof and a flange formed around a second end thereof, and the second end of the inner rod is inserted into the outer rod, such that the flange is limited by the shoulder of the limiting sleeve. The inner rod also includes a slot passing through a middle section thereof. 
     The actuation post includes a second screwing section defined around a first end thereof and a bushing fitted on a second end thereof. The bushing has a through hole horizontally formed therein, wherein the second screwing section of the actuation post is inserted into the outer rod, and the bushing is inserted into the inner rod. The actuation post also includes a holding sheath fitted on the inner rod and a bolt inserted through the holding sheath, the slot of the inner rod, and the through hole of the bushing. The actuation post further includes a stopping piece fixed on a middle section thereof. 
     The pushing member includes a conical face defined on a first end thereof, a second end inserted into the inner rod, an orifice formed thereon so as to inert the second screwing section of the actuation post, and a spring being biased against the pushing member and the stopping piece. 
     The expending member includes an aperture for fitting the expending member with the first end of the actuation post, a nut for screwing with the second screwing section so as to limit the expending member and the pushing member, a plurality of expansion sheets vertically extending around an outer wall thereof and surrounding around the actuation post, and a resilient loop fitted on a distal end thereof, such that the conical face of the pushing member pushes the plurality of expansion sheets to force the resilient loop, and then the resilient loop is biased against the first screwing section of the outer rod, thereby fixing the outer rod and the inner rod securely. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the assembly of an adjustable positioning structure for a walking stick according to a preferred embodiment of the present invention. 
         FIG. 2  is a perspective view showing the exploded components of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 3  is a cross sectional view showing the assembly of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 4  is a perspective view showing the operation of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 5  is a cross sectional view showing the operation of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 6  is another cross sectional view showing the operation of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 7  is also another cross sectional view showing the operation of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 8  is a diagram showing the application of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 9  is still another cross sectional view showing the operation of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 10  is another cross sectional view showing the operation of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 11  is another diagram showing the application of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 12  is also another diagram showing the application of the adjustable positioning structure for the walking stick according to the preferred embodiment of the present invention. 
         FIG. 13  is a perspective showing the exploded components of a conventional a walking stick with an adjustable positioning structure. 
         FIG. 14  is a cross sectional showing the operation of the conventional the walking stick with the adjustable positioning structure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 and 2 , an adjustable positioning structure for a walking stick comprises an outer rod  10 , an inner rod  20 , a driving shaft  30 , and a pushing member  40 . The outer rod  10  includes a griping head  11  disposed on a first end thereof and a limiting sleeve  12  mounted on a second end thereof, the limiting sleeve  12  has a shoulder  121  formed on an inner wall thereof and inner threads  122  above the shoulder  12 . The outer rod  10  also includes outer threads  13  arranged around an outer wall thereof so as to screw with the inner threads  122  of the limiting sleeve  12  and includes a first screwing section  14  defined around an inner wall thereof. The inner rod  20  includes an anti-slip pad  21  fixed on a first end thereof so as to abut against a ground and includes a flange  22  formed around a second end thereof, wherein the second end of the inner rod  20  is inserted into the outer rod  10 , such that the flange  22  is limited by the shoulder  121  of the limiting sleeve  12 . The inner rod  20  also includes a slot  23  passing through a middle section thereof and an actuation post  30 . The actuation post  30  includes a second screwing section  31  defined around a first end thereof and a bushing  32  fitted on a second end thereof, the bushing  32  has a screw hole  321  vertically arranged therein so as to screw with the actuation post  30  and has a through hole  322  horizontally formed therein, wherein the second screwing section  31  of the actuation post  30  is inserted into the outer rod  10 , and the bushing  32  is inserted into the inner rod  20 . The actuation post  30  also includes a holding sheath  33  fitted on the inner rod  20  and a bolt  34  inserted through the holding sheath  33 , the slot  23  of the inner rod  20 , and the through hole  322  of the bushing  32 . The holding sheath  33  has a groove  331  defined thereon so as to fit with a flexible ring  35 , such that the flexible ring  35  covers the bolt  34 . The actuation post  30  further includes a stopping piece  36  fixed on a middle section thereof, and the pushing member  40  includes a conical face  41  defined on a first end thereof, a second end inserted into the inner rod  20 , an annular rib  42  arranged around a middle section thereof and abutting against an opening of the inner tube  20 , an orifice  43  formed thereon so as to inert the second screwing section  31  of the actuation post  30 , and a spring  44  being biased against the pushing member  40  and the stopping piece  36 . The adjustable positioning structure also comprises an expending member  50 , and the expending member  50  includes an aperture  51  for fitting the expending member  50  with the first end of the actuation post  30 , a nut  52  for screwing with the second screwing section  31  so as to limit the expending member  50  and the pushing member  40 , a plurality of expansion sheets  53  vertically extending around an outer wall thereof and surrounding around the actuation post  30 , and a resilient loop  54  fitted on a distal end thereof, wherein a first surrounding tab  531  and a second surrounding tab  532  are arranged around the plurality of expansion sheets  53  and are provided to limit the resilient loop  54 , such that the conical face  41  of the pushing member  40  pushes the plurality of expansion sheets  53  to force the resilient loop  54 , and then the resilient loop  54  is biased against the first screwing section  14  of the outer rod  10 , thereby fixing the outer rod  10  and the inner rod  20 . 
     Referring further to  FIGS. 1-3 , in assembly, the bushing  32  is screwed with the actuation post  30  by using the screw hole  321 , and the through hole  322  of the bushing  32  is aligned with the slot  23  of the inner rod  20 , the limiting sleeve  12  is fitted onto the inner rod  20  so that the flange  22  of the inner rod  20  is limited by the shoulder  121  of the limiting sleeve  12 , thereafter the holding sheath  33  is fitted on the inner rod  20 , and the bolt  34  is inserted through the holding sheath  33 , the slot  23  and the through hole  322  so that the holding sheath  33  is connected with the bushing  32  and moves along the slot  23  of the inner rod  20 , the flexible ring  35  is fitted with the groove  331  of the holding sheath  33 , the anti-slip pad  21  is fitted with the second end of the inner rod  20 , and the spring  44  is fitted into the actuation post  30  from the second end of the inner rod  20  so as to abut against the stopping piece  36 . Furthermore, the pushing member  40  is fitted on the actuation post  30  by ways of the orifice  43  and pushes the inner rod  20 , such that the conical face  41  of the pushing member  40  extends out of the inner rod  20 , and the spring  44  abuts against the pushing member  40 . The resilient loop  54  is fitted on the plurality of expansion sheets  53  of the expending member  50  and is limited by the first surrounding tab  531  and the second surrounding tab  532 , the expending member  50  is fitted on the actuation post  30  by means of the aperture  51 , and the nut  52  is screwed with the second screwing section  31  of the actuation post  30 , thus connecting the expending member  50  with the actuation post  30 . The inner rod  20  is inserted into the outer rod  10  by means of the expending member  50 , and the inner threads  122  of the limiting sleeve  12  is screwed with the outer threads  13  of the outer rod  10 , thus preventing the inner rod  20  from remove from the outer rod  10 . Thereafter, the griping head  11  is screwed with the outer rod  10 , thus assembling the walking stick completely. 
     As shown in  FIGS. 2 ,  4  and  5 , in operation, since the spring  44  is biased against the pushing member  40  and the stopping piece  36  of the actuation post  30  so that the actuation post  30  controls the plurality of expansion sheets  53  to press the conical face  41  of the pushing member  40 , such that the resilient loop  54  contacts with the first screwing section  14  of the outer rod  10 , so when a user walks by using the walking stick, the griping head  11  is gripped and forced so that a gripping force is conducted to the outer rod  10 . Since the resilient loop  54  of the expending member  50  contacts with the first screwing section  14  of the outer rod  10 , the outer rod  10  drives the expending member  50  to press the conical face  41  of the pushing member  40 , such that the pushing member  40  drives the plurality of expansion sheets  53  to extend outwardly so as to support the griping head  11 , and the resilient loop  54  of the expending member  50  is expended by the plurality of expansion sheets  53  so as to contact with the first screwing section  14  of the outer rod  10  tightly. Preferably, a friction resistance between the first screwing section  14  and the resilient loop  54  is increased to enhance support safety. 
     Referring further to  FIGS. 6 and 7 , when the user holds the gripping head  11  or the outer rod  10  with one hand and grips the inner rod  20  or the ante anti-slip pad  21  with the other hand so as to pull the outer rod  10  and the inner rod  20  outwardly, it is not necessary to rotate a rotating element or to press a press button to extend the walking stick, thereby extending the walking stick easily. After extending the inner rod  20 , the inner rod  20  drives the pushing member  40  to remove from the expending member  50 , in the meantime, the actuation post  30  and the expending member  50  will not move with the inner rod  20 . Furthermore, the conical face  41  of the pushing member  40  does not press the plurality of expansion sheets  53 , so the resilient loop  54  does not contact with the first screwing section  14  of the outer rod  10 , thus extending the outer rod  10  and the inner rod  20  smoothly. Also, the spring  44  pushes the actuation post  30  so that the expending member  50  presses the pushing member  40  to position an extending length of the outer rod  10  and the inner rod  20 . As shown in  FIG. 8 , the walking stick is extended to support the user to step down the stairs. As desiring to retract the walking stick, as illustrated in  FIGS. 9 and 10 , the user holds the gripping head  11  or the outer rod  10  with one hand and grips the inner rod  20  with the other hand. Moreover, the user also clamps the holding sheath  33  with two fingers and pushes the holding sheath  33  toward the griping head  11 , such that the bolt  34  is driven by the holding sheath  33  to move along the slot  23  of the inner rod  20 , and the bushing  32  drives the actuation post  30  to move toward the griping head  11  so that the spring  44  is pressed by the actuation post  30 , and the plurality of expansion sheets  53  of the expending member  50  move away from the conical face  41  of the pushing member  40 , hence the resilient loop  54  does not contact with the first screwing section  14  of the outer rod  10 , and the outer rod  10  does not contact with the inner rod  20 , thereby retracting the walking stick quickly. It is preferable that the conical face  41  of the pushing member  40  moves away from the plurality of expansion sheets  53  so that the plurality of expansion sheets  53  and the resilient loop  54  retract inwardly, thereby retracting the walking stick easily. As shown in  FIGS. 11 and 12 , after the walking stick is retracted, the user can step up to the stairs and stand up by ways of the walking stick. Accordingly, the adjustable positioning structure of the present invention is applied to adjust a length of the walking stick easily and to position the walking stick securely. 
     While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.