A seat horizontal movement switching section is operated in a horizontal direction for moving an entire seat in a horizontal direction. The self-lubricating oil tank is fixed on the slide block, and the self-lubricating oil tank has an oil-storage space and a lubricating unit. Raised posts formed by photoresist are patterned into columns oriented orthogonally to the bottom row electrodes. The toe portion receives the sole plate and is slidably attached to the heel portion. Each stake is dimensioned to abut a surface of a staple to apply pushing forces thereto.