To solve the problem that a secular looseness generates and a large number of movable brackets do not satisfy a design strength because a clamping can not be conducted sufficiently on a structure in a conventional movable bracket and the movable bracket in a type having a structure requiring two axes opposes to an appearance aiming at a compactness.

A spherical projection is used for a bent section, and clamped and fixed by bracket itself, thus ensuring the clamping for a movable section, then attaining an improvement in an accuracy on the execution of works. The appearance is simplified because the two axes are not required and upper and lower and left and right sections are moved.