Foldable furniture with a positioning unit

Abstract

A foldable furniture includes pivotally connected first and second parts. The first part includes a tubular portion that is formed with a retaining hole. An annular sleeve is sleeved slidingly around the tubular portion. A limiting member is disposed within the tubular portion, and includes a spring-biased limiting tongue projecting into the retaining hole of the tubular portion. The spring-biased limiting tongue is operable to move between an extended position, where the limiting tongue projects outwardly from the retaining hole to engage the sleeve so as to restrict movement of the annular sleeve on the tubular portion, and a retracted position, where the limiting tongue retracts into the retaining hole to disengage from the sleeve and permit movement of the annular sleeve on the tubular portion.

I claim:  
     
         1 . A foldable furniture comprising: 
 first and second parts pivoted to each other via a pivot, said first part including an elongated tubular portion that is formed with a retaining hole; and    a positioning unit including 
 an annular sleeve sleeved slidingly around said tubular portion and connected securely to said pivot in such a manner that said pivot projects radially and outwardly from said annular sleeve, and  
 a limiting member disposed within said tubular portion and including a spring-biased limiting tongue projecting into said retaining hole, said spring-biased limiting tongue being operable to move between an extended position, where said limiting tongue projects outwardly from said retaining hole to abut against and engage said annular sleeve so as to restrict movement of said annular sleeve on said tubular portion, and a retracted position, where said limiting tongue retracts into said retaining hole so as to disengage from said annular sleeve and permit movement of said annular sleeve on said tubular portion.  
   
     
     
         2 . The foldable furniture as defined in  claim 1 , wherein said annular sleeve includes an annular inner layer, and an annular outer layer circumferentially surrounding said inner layer, said outer layer having opposing flat end faces, said inner layer having a flat end face flush with one of said flat end faces of said outer layer, and a conical end face extending from the other one of said flat end faces of said outer layer, said tongue having a curved end that permits said conical end face to slide thereon, thereby permitting said tongue to move from said extended position to said retracted position.  
     
     
         3 . The foldable furniture as defined in  claim 2 , wherein said limiting member includes a V-shaped spring plate having spaced apart distal ends, said limiting tongue being fixed on one of said distal ends and being urged by said spring plate to move into said retaining hole.  
     
     
         4 . The foldable furniture as defined in  claim 3 , further comprising a limiting stop detachably mounted on said tubular portion adjacent to said conical end face of said annular sleeve, and cooperating with said limiting tongue so as to immobilize said annular sleeve on said tubular portion between said limiting stop and said limiting tongue when said limiting tongue is moved to said extended position and engages said flat end face of said inner layer of said sleeve.  
     
     
         5 . A positioning unit for positioning first and second parts of a foldable furniture, the first and second parts being pivoted to each other about a pivot, the first part including an elongated tubular portion that is formed with a retaining hole, said positioning unit comprising: 
 an annular sleeve adapted to be sleeved slidingly around the tubular portion, and connected securely to the pivot in such a manner that the pivot projects radially and outwardly from said annular sleeve; and    a limiting member adapted to be disposed within the tubular portion and including a spring-biased limiting tongue adapted to project into the retaining hole, said spring-biased limiting tongue being operable to move between an extended position, where said limiting tongue is adapted to project outwardly from the retaining hole to abut against and engage said annular sleeve so as to restrict movement of said annular sleeve on the tubular portion, and a retracted position, where said limiting tongue is adapted to retract into the retaining hole so as to disengage from said annular sleeve and permit movement of said annular sleeve on the tubular portion.    
     
     
         6 . The positioning unit as defined in  claim 5 , wherein said annular sleeve includes an annular inner layer, and an annular outer layer circumferentially surrounding said inner layer, said outer layer having opposing flat end faces, said inner layer having a flat end face flush one of said flat end faces of said outer layer, and a conical end face extending from the other one of said flat end faces of said outer layer, said tongue having a curved end that permits said conical end face to slide thereon, thereby permitting said tongue to move from said extended position to said retracted position.  
     
     
         7 . The positioning unit as defined in  claim 6 , wherein said limiting member includes a V-shaped spring plate having spaced apart distal ends, said limiting tongue being fixed on one of said distal ends so as to be urged by said spring plate to move into the retaining hole.  
     
     
         8 . The positioning unit as defined in  claim 7 , further comprising a limiting stop adapted to be mounted detachably on said tubular portion adjacent to said conical end face of said annular sleeve, and cooperating with said limiting tongue so as to immobilize said annular sleeve on the tubular portion between said limiting stop and said limiting tongue when said limiting tongue is moved to said extended position and engages said flat end face of said inner layer of said sleeve.