Patent attributes
A horizontal universal joint includes a first joint member and a second joint member. The first joint member is integrally formed by a frame insertion port and a female coupling port. The second joint member is integrally formed by a frame insertion port and a male coupling port. The female coupling port of the first joint member and the male coupling port of the second joint member are removably engaged via an elastic body. Teeth rows are formed at an inner peripheral surface of the female coupling port and an outer peripheral surface of the male coupling port meshing with one another. Depending on meshing positions of both teeth rows when the male coupling port is inserted into the female coupling port, the horizontal direction where the frame insertion port of the second joint member faces relative to the frame insertion port of the first joint member is changeable.