초록 ▼

A stepladder provided with a coupling frame in the shape of an equilateral triangle, a front support, a rear right support, a rear left support, and spread stoppers for stopping the front support, the rear right support, and the rear left support from spreading. The front support is rotationally att

A stepladder provided with a coupling frame in the shape of an equilateral triangle, a front support, a rear right support, a rear left support, and spread stoppers for stopping the front support, the rear right support, and the rear left support from spreading. The front support is rotationally attached to a front shaft of the coupling frame, the rear right fixing member is rotationally attached to a right shaft, and the rear left fixing member is rotationally attached to a left shaft. The rear left support and the rear right support are detachably mounted to the rear left fixing member and the rear right fixing member, respectively. The supports of the stepladder are coupled by the spread stoppers, whereby the three supports are restricted from being displaced forward, to the right rear, and to the left rear.

대표청구항 ▼

1. A stepladder comprising: a coupling frame having a front shaft, a right shaft and a left shaft that are connected with each other to form a triangle, the coupling frame being entirely formed from a pipe;a front support that is coupled to the coupling frame and includes a ladder and a first leg th

1. A stepladder comprising: a coupling frame having a front shaft, a right shaft and a left shaft that are connected with each other to form a triangle, the coupling frame being entirely formed from a pipe;a front support that is coupled to the coupling frame and includes a ladder and a first leg that can extend and contract;a rear right support that is coupled to the coupling frame by a rear right fixing member and includes a second leg that can extend and contract;a rear left support that is coupled to the coupling frame by a rear left fixing member and includes a third leg that can extend and contract; anda spread stopper that limits spreading of the front support, the rear right support, and the rear left support,a first coupling pipe of the front support being rotationally coupled to the front shaft of the coupling frame so as to permit said first coupling pipe to rotate about said front shaft,a second coupling pipe of the rear right fixing member being rotationally coupled to the right shaft so as to permit said second coupling pipe to rotate about said right shaft,a third coupling pipe of the rear left fixing member being rotationally coupled to the left shaft so as to permit said third coupling pipe to rotate about said left shaft, whereinthe rear left support and the rear right support are attached to the rear left fixing member and the rear right fixing member, respectively, in a removable manner,including the front support, the rear left support, and the rear right support form the stepladder, andthe spread stopper couples all said supports together so that the three supports are arranged to form a triangular pyramid and displacement of the three supports in three directions including a front direction, a rear right direction, and a rear left direction is restricted. 2. The stepladder according to claim 1, wherein the rear left fixing member includes a hollow pipe body that opens at a lower end thereof,the rear right fixing member includes a hollow pipe body that opens at a lower end thereof,a lower portion of the pipe body of each fixing member includes a cut out groove,a distal end section that extends upward from a body section of each support has a reduced outer diameter over a length that is inserted into the pipe body of a corresponding one of the fixing members, so that each support includes a step formed between the distal end section and the body section,a tip section of each support is tapered,the distal end section of each support includes a projection for positioning,the cut out groove of each fixing member has a width that is greater than an outer diameter of the projection,each cut out groove includes: a first linear section that extends upward from a cut end at an inner side of the lower portion of the pipe body of each fixing member and is parallel with an axis of the fixing member;an inclined section extending outward and diagonally downward from an uppermost position of the first linear section; anda second linear section that extends upward and downward from a lowermost position of the inclined section and is parallel with the axis of the fixing member, andwhen each support is inserted and coupled to the pipe body of a corresponding one of the fixing members, the projection is aligned with the cut end of the cut out groove after the distal end section of the support is inserted,the projection and the support are moved upward along the first linear section of the cut out groove,the projection and the support are moved downward along the inclined section from a position where the upward movement ends,the projection and the support are moved upward along the second linear section from a position where the downward movement ends, andcoupling of the support to the fixing member completes when the upward movement ends,when the coupling of each support completes, the lower portion of the pipe body of the fixing member is in contact with the step of the support, anda shape of the cut out groove of the lower portion of the pipe body of the rear right fixing member and a shape of the cut out groove of the rear left fixing member are symmetrical. 3. The stepladder according to claim 1, wherein a top operation platform is arranged between the coupling frame and the front support, andthe top operation platform is rotationally coupled to the coupling frame by a pipe and rotationally coupled to the front support by another pipe.