Abstract:
An adjustable pole comprising an upper pole telescopically engaged with a lower pole. The adjustable pole further comprises a locking unit secured to an upper end of the lower pole. The locking unit comprises a housing having a lower bore engaged with the upper end of the lower pole. The housing further comprises an upper bore disposed above the lower bore for freely receiving the upper pole into and out of the lower pole. The housing further comprises a channel disposed adjacent the upper bore. The locking unit further comprises a lever rotatably supported within the channel between a locked position where the upper pole cannot move relative to the lower pole and an unlocked position where the upper pole may be moved. The lever comprises a tooth catch engaged with the upper pole and substantially shielded by the channel between the locked and unlocked positions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application Ser. No. 61/317,246 filed on Mar. 24, 2010, which is hereby incorporated by reference in its entirety into this specification. 
    
    
     BACKGROUND OF THE INVENTION 
     Referring to  FIG. 1 , a conventional adjustable pole assembly  10  is shown having an upper pole  14  telescopically mounted within a lower pole  12 . A locking unit  16  is secured to the upper end of lower pole  12 . Locking unit  16  has outward extending left and right flanges  18  and  20 . A lever  22  having a sharp edge  24  and a handle  26  is rotatably mounted within left and right flanges  18  and  20  and by a spring  28  between a normally biased locked position where sharp edge  24  securely engages upper pole  14  and an unlocked position upon depression of handle  26  where upper pole  14  can be adjusted. Conventional devices of this type suffer from various drawbacks. By way of example only, such conventional devices have a fully exposed sharp edge  24  that may inadvertently pinch and/or otherwise make contact with a person&#39;s finger or clothing during the unlocking and locking process thereby causing damage and/or injury. By way of further example, such conventional devices do not allow locking unit  16  to be quickly replaced at the work site. Still further, the rubber sleeve thumb grip  26  employed by such conventional devices becomes damaged by continuous contact and movement with spring  28 . 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide an adjustable pole having a locking unit that is safer to use than conventional devices. 
     Another object of the present invention is to provide an adjustable pole having a locking unit that can be easily replaced at the work site. 
     Another object of the present invention is to provide an adjustable pole having a locking unit that is more durable and has a longer life than conventional devices. 
     The present invention is an adjustable pole comprising an upper pole telescopically engaged with a lower pole. The adjustable pole further comprises a locking unit secured to an upper end of the lower pole. The locking unit comprises a one-piece unitary housing having a lower bore engaged with the upper end of the lower pole. The housing further comprises an upper or guide bore disposed above the lower bore for freely receiving and guiding the upper pole into and out of the lower pole. The upper and lower bores have a common central axis. The housing further comprises a channel disposed adjacent the upper bore. The channel comprises a floor, left and right sidewalls, and a top wall. The channel further comprises a slot having a first portion formed in the floor and a second portion formed in the top wall to provide access between the channel and the upper pole. The locking unit further comprises a lever rotatably supported within the channel between a locked position where the upper pole cannot move relative to the lower pole and an unlocked position where the upper pole may be moved. The lever comprises a handle portion disposed outward of the channel and a tooth catch engaged with the upper pole. The tooth catch is substantially shielded by the left and right sidewalls and top wall of the channel between the locked and unlocked positions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following description of the invention will be more fully understood with reference to the accompanying drawings in which: 
         FIG. 1  is a perspective view of a prior art adjustable pole; 
         FIG. 2  is a perspective view of an adjustable pole according to the present invention shown in a locked position; 
         FIG. 3  is an exploded perspective view of the adjustable pole showing a locking unit according to the present invention; 
         FIG. 4  is a cross-section of the adjustable pole in a locked position with the locking unit engaged with an upper pole; 
         FIG. 5  is a cross-section view of the adjustable pole in an unlocked position with the locking unit disengaged from the upper pole; 
         FIG. 6  is a front view of a housing of the locking unit; 
         FIG. 7  is a bottom view of the housing; 
         FIG. 8  is a top view of the housing; 
         FIG. 9  is a perspective view of a thumb grip according to the present invention; 
         FIG. 10  is a front view of a thumb grip; 
         FIG. 11  is a bottom view of the thumb grip; 
         FIG. 12  is a perspective of a spring according to the present invention; 
         FIG. 13  is a perspective view of a lever according to the present invention; 
         FIG. 14  is a cross-section view of a second embodiment of an adjustable pole according to the present invention with a locking unit shown in a locked position; 
         FIG. 15  is a cross-section view of the second embodiment showing the locking unit in an unlocked position; 
         FIG. 16  is a cross-section view of a third embodiment of an adjustable pole according to the present invention with a locking unit shown in a locked position; and 
         FIG. 17  is a cross-section view of the third embodiment showing the locking unit in an unlocked position. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 2 and 3 , an adjustable pole assembly  100  according to the present invention generally comprises a lower pole  102  having an upper end  106 , an upper pole  112  having a lower end  114 , and a locking unit  118 . Upper pole  112  is telescopically engaged within lower pole  102 . Locking unit  118  generally comprises a one-piece unitary housing  120 , a spring  172 , a lever  180  having a tooth catch  182 , and a thumb grip  188 . As shown by  FIG. 4 , in a normally biased state, tooth catch  182  secures upper pole  112  at a selected position relative to lower pole  102 . As shown by  FIG. 5 , upon depression of lever  180 , tooth catch  182  is completely disengaged from upper pole  112  allowing it to be adjusted upward or downward relative to lower pole  102 . Tooth catch  182  extends a short distance H outward of housing  120  and faces upper pole  112  thereby substantially shielding it from a person&#39;s finger or clothing during use. 
     With continued reference to  FIGS. 2 and 3 , lower pole  102  further comprises protrusions  108  and  110  extending outward from opposite sides of upper end  106 . Protrusions  108  and  110  are formed by a conventional crimping or plier tool. As will be described more fully herein, protrusions  108  and  110  provide a male fastener means to secure housing  120  of locking unit  118  to upper end  106  of lower pole  102 . Lower and upper poles  102  and  112  are made from conventional metal tubing such as aluminum and cut to the desired length. Lower pole  102  has an outside diameter of 1.000 inches and an inside diameter of 0.920 inches. Upper pole  112  has an outside diameter of 0.875 inches and an inside diameter of 0.798. 
     Referring to  FIGS. 6-8 , housing  120  comprises a lower bore  122  having an annular outer wall  124  beginning at a bottom end  130  and terminating at a floor or flange  132 . Lower bore  122  further comprises thru-holes  126  and  128  ( FIGS. 2 and 3 ) disposed on opposite sides of annular wall  124 . Lower bore  122  has a diameter slightly larger than the outside diameter of lower pole  102 . Upper end  106  of lower pole  102  is inserted into lower bore  122  until the top edge of upper end  106  abuts floor or flange  132 . Upon complete engagement of lower pole  102  with lower bore  122 , thru-holes  126  and  128  engage with protrusions  108  and  110 , respectively, of lower pole  120  thereby securing housing  120  on upper end  106 . The use of one or more holes or protrusions  108  and  110  on housing  120  allow housing  120  to be quickly dimpled to lower pole  102  by a portable hand held tool. Housing  120  is snapped onto lower pole  102  after dimpling is completed. This gives the advantage of easy on-site replacement of a damaged locking unit  118 . Another advantage of this method is with a simple plier type hand tool, a worker can dimple his/her own tooling for the application of locking unit  118 . 
     With continued reference to  FIGS. 6-8 , housing  120  further comprises an upper bore or guide  134  having an annular inner wall  136  and a top end  138 . Upper bore  134  freely guides upper pole  112  into and out of lower pole  102 . Upper bore or guide  134  has a diameter slightly larger than the outside diameter of upper pole  112 . Lower bore  122  and upper bore  134  share a common central axis. Lower bore  122  has a diameter D 1 . Upper bore  134  has a diameter D 2 . The diameter D 1  of lower bore  122  is larger than the diameter D 2  of upper bore  134  thereby preventing upper end  106  of lower pole  102  from entering upper bore  134 . 
     With continued reference to  FIGS. 6-8 , housing  120  further comprises a channel  140  extending substantially from bottom end  130  of lower bore  122  to top end  138  of upper bore Channel  140  comprises a floor  142 , lower left and right sidewalls  144  and  146 , and a top wall  160 . Top wall  160  has inside and outside surfaces  162  and  164 , respectively. Channel  140  further comprises upper left and right sidewalls  148  and  154  extending upward from floor  142 . Left sidewall  148  comprises a thru-hole  152  to receive one end of a pin or rivet  202  (shown in  FIG. 3 ). Right sidewall  154  comprises a thru-hole  158  to receive the opposite end of pin or rivet  202 . Channel  140  further comprises a slot  166  having a first portion  168  disposed in floor  142  and a second portion  170  disposed in top wall  160 . An upper end of first portion  168  of slot  166  is merged with second portion  170  of slot  166  to provide a continuous L-shaped slot  166  providing access between channel  140  and upper pole  112  disposed in upper bore  134 . First portion  168  of slot  166  extends from a point just above lower bore  122  to top wall  160 . Housing  120  may be made from conventional materials such as plastic and fabricated by conventional molding processes. 
     Referring to  FIG. 12 , spring  172  comprises a base portion  174  having spaced elongated members  173  and  175 . Spring  172  further comprises an upper portion  176  having an elongated loop portion  178  bent at about forty five degrees to base portion  174 . As best shown by  FIGS. 3-5 , base  174  of spring  172  rests upon or is engaged with floor  142  of housing  120 . A forward portion  177  of elongated members  173  and  175  are disposed between sidewalls  148  and  154  and are slighted compressed laterally so that spring  172  will not slide out of floor  142 . As will be described more fully herein, elongated loop portion  178  engages with a seat  198  and flange  199  (to be described) of thumb grip  188  to reduce relative movement of thumb grip  188  and spring  172  upon depression of thumb grip  188 . Spring  172  is made from a single piece of conventional spring steel and formed by conventional bending and cutting operations. 
     Referring to  FIGS. 3 ,  6 , and  13 , lever  180  rotates within channel  140  about pin or rivet  202 . Lever  180  comprises tooth catch  182  and handle  87  as previously described. Lever  180  further comprises a centrally located thru-hole  186 . Pin or rivet  202  passes thru hole  186  and thru-holes  152  and  158 . Tooth catch  182  has forward and rear sharp edges  183  and  184  separated by a valley  185  to grab or penetrate the outside surface of upper pole  112 . Forward and rear sharp edges  183  and  184  provide the advantage of additional gripping or holding power while minimizing damage to the pole. Handle  87  has an rectangular cross section that mates or engages within a cavity  200  (to be described) of thumb grip  188 . As best shown by  FIGS. 4 and 5 , tooth catch  182  of lever  180  rotates substantially within slot  166  of channel  140  and faces upper pole  112 . Only the uppermost surface of tooth catch  182  extends slightly above top wall  160  which has no sharp edges. The channel and slot design of locking unit  118  provides a significantly safer device than conventional locking devices. In other embodiments, as will be described more fully herein, lever  180  may be mounted lower in channel  140  so that all surfaces of tooth catch  182  are below top wall  160 . To provide sufficient gripping force, tooth catch  182  has a hardness greater than the material of upper pole  112 . Lever  180  may be made from a conventional metal such as stainless steel and fabricated by conventional machining operations. 
     Referring to  FIGS. 9-11 , thumb grip  188  comprises a front end  190 , a rear end  192 , a top  194 , and a bottom  196 . Thumb grip  188  further comprises a seat  198  that engages with elongated loop portion  178  of spring  172 . Thumb grip  188  further comprises a cavity  200  extending inward from front end  190 . Cavity  200  is sized to snugly receive handle  187  of lever  180 . Secure engagement of seat  198  and elongated loop portion  178  provides the advantage of a more stable locking unit that provides efficient transfer of spring energy to tooth catch  182  and upper pole  112 . Further, relative movement between thumb grip  188  and spring  172  is reduced thereby increasing the overall life of each part. Thumb grip  188  may be made from a conventional plastic material and fabricated by conventional molding processes. 
     Referring to  FIGS. 14 and 15 , where a second embodiment of locking unit  118  is shown. In  FIG. 14 , locking unit  118  is shown in a normally biased locked state where tooth catch  182  secures upper pole  112  at a selected position relative to lower pole  102 . In.  FIG. 15 , locking unit  118  is shown in an unlocked state where lever  180  has been depressed and tooth catch  182  is completely disengaged from upper pole  112  allowing it to be adjusted upward or downward relative to lower pole  102 . Tooth catch  182  is disposed below the top surface  164  of top wall  160  and faces upper pole  112  thereby substantially if not completely shielding it from a person&#39;s finger or clothing during use. 
     Referring to  FIGS. 16 and 17 , where a third embodiment of locking unit  118  is shown. In  FIG. 16 , locking unit  118  is shown in a normally biased locked state where tooth catch  182  secures upper pole  112  at a selected position relative to lower pole  102 . In.  FIG. 17 , locking unit  118  is shown in an unlocked state where lever  180  has been depressed and tooth catch  182  is completely disengaged from upper pole  112  allowing it to be adjusted upward or downward relative to lower pole  102 . Tooth catch  182  is completely disposed below top wall  160  of housing  120  and faces upper pole  112 . In this embodiment, second slot portion  170  of slot  166  has been removed from top wall  160 . Use of a solid top wall  160  further shields tooth catch  182  from a person&#39;s finger or clothing during use. 
     The foregoing description is intended primarily for purposes of illustration. This invention may be embodied in other forms or carried out in other ways without departing from the spirit or scope of the invention.