US Patent 7121723 Linear guide apparatus

A linear guide apparatus is provided with two (upper and lower) tracks of rolling element race tracks formed on a guide rail and of rolling element race tracks formed on a slider main body so as to oppose the rolling element race tracks on the respective sides, i.e., four tracks of race tracks in total. A recess is provided below the lower rolling element race track on the slider main body and the end cap fixed to an end face of the slider main body is provided with a projection that engages with the recess so as to determine a position of the end cap.