Extendable rod with a twist lock mechanism

Abstract

An extendable rod with a twist lock mechanism. The extendable rod comprises a first tube and a second tube configured to be coaxially disposed within the first tube via an open end of the first tube. The extendable rod comprises a locking mechanism configured between the first tube and the second tube. The locking mechanism is configured between the first tube and the second tube such that rotation of the second tube in a predefined direction with respect to the first tube causes the second tube to move from a first position to a second position away from the first tube and further restrict relative movement between the first tube and the second tube at the second position.

I claim: 
     
         1 . An extendable rod comprising:
 a first tube;   a second tube configured to be coaxially disposed within the first tube via an open end of the first tube; and   a locking mechanism configured between the first tube and the second tube, wherein the locking mechanism comprises:
 a stud that comprises external threads at a first end that is configured to be at least partially fitted into an open end of the second tube, and wherein a tapered mandrel is configured at a second end of the stud which extends within the first tube upon coaxially disposing the second tube within the first tube, wherein the tapered mandrel has a substantially frustoconical profile having diameter increasing in an axial direction moving away from the second tube; 
 a bush configured to be coaxially and rotationally disposed between an outer surface of the stud and an inner wall of the first tube at the open end of the first tube, wherein a first end of the bush comprises internal threads that is adapted to engage with the external threads of the stud; 
 at least two split bushes attached to or configured at a second end of the bush, such that the at least two split bushes remains coaxially disposed over an outer surface of the tapered mandrel; and 
 a rubber sleeve coaxially disposed between an outer surface of the at least two split bushes and the inner wall of the first tube; 
 wherein the locking mechanism is configured between the first tube and the second tube such that rotation of the second tube in a predefined direction with respect to the first tube causes the second tube to move from a first position to a second position away from the first tube and further restrict relative movement between the first tube and the second tube at the second position. 
   
     
     
         2 . The extendable rod as claimed in  claim 1 , wherein rotation of the first tube or the second tube in a clockwise direction causes the second tube to move towards the second position and further enable movement of the bush away from the second tube, resulting in sliding of the at least two split bushes over the tapered mandrel and correspondingly expanding the rubber sleeve. 
     
     
         3 . The extendable rod as claimed in  claim 2 , wherein the expansion of the rubber sleeve creates a frictional contact between the stud and the inner wall of the first tube to lock the second tube at the second position. 
     
     
         4 . The extendable rod as claimed in  claim 2 , wherein the clockwise rotation of the second tube or the first tube moves the second tube to the second position, thereby increasing the length of the rod and corresponding enable fitting of the rod against two opposite support surfaces. 
     
     
         5 . The extendable rod as claimed in  claim 1 , wherein rotation of the first tube or the second tube in a counter-clockwise direction causes the second tube to move towards the first position and further enable movement of the bush away from the second tube, resulting in sliding of the at least two split bushes away from the tapered mandrel and correspondingly contracting the rubber sleeve. 
     
     
         6 . The extendable rod as claimed in  claim 5 , wherein the bush is configured to prevent anti-locking of the second tube and the first tube when rotated in the counter-clockwise direction. 
     
     
         7 . The extendable rod as claimed in  claim 1 , wherein the second tube and the first tube are made of material selected from the group consisting of: cold-rolled steel, brass, high-grade steel, iron, aluminium or polymeric material. 
     
     
         8 . A locking mechanism for an extendable rod comprising a first tube and a second tube coaxially disposed within the first tube, the locking mechanism comprising:
 a stud that comprises external threads at a first end that is configured to be at least partially fitted into an open end of the second tube, and wherein a tapered mandrel is configured at a second end of the stud which extends within the first tube upon coaxially disposing the second tube within the first tube, wherein the tapered mandrel has a substantially frustoconical profile having diameter increasing in an axial direction moving away from the second tube;   a bush configured to be coaxially and rotationally disposed between an outer surface of the stud and an inner wall of the first tube at the open end of the first tube, wherein a first end of the bush comprises internal threads that is adapted to engage with the external threads of the stud;   at least two split bushes attached to or configured at a second end of the bush, such that the at least two split bushes remains coaxially disposed over an outer surface of the tapered mandrel; and   a rubber sleeve coaxially disposed between an outer surface of the at least two split bushes and the inner wall of the first tube;   
       wherein the locking mechanism is configured between the first tube and the second tube such that rotation of the second tube in a predefined direction with respect to the first tube causes the second tube to move from a first position to a second position away from the first tube and further restrict relative movement between the first tube and the second tube at the second position. 
     
     
         9 . The locking mechanism as claimed in  claim 8 , wherein the tapered mandrel is coupled to the stud at the second end using a thread connection. 
     
     
         10 . The locking mechanism as claimed in  claim 8 , wherein the at least two split bushes comprises an expansion anchor integrally formed with the bush.