| 摘要 |
PROBLEM TO BE SOLVED: To suppress generation of defective ball trays to improve productivity by integrally assembling a ball tray member and a cover member putting a retaining member between both members. SOLUTION: Retaining protrusions 19, 19,... are inserted into engaging holes 15, 15,... opened in the bottom face of a cover member from the lower side and the cover member is fit into a ball tray member. The lower end parts of communicating protrusions are fit into and abut on upper dent recess parts 193 of retaining protrusions 19, 19,... and screw holes and screw stopping holes 194 respectively match each other. The backside of each engaging hole 15 is formed into a counterbore large diameter recess part 151 in a bore almost same as the outer diameter of a flange 195 and the flange 195 is made housed thereinto so as not to be swollen out from the bottom wall 11. A small screw is inserted from the lower end face of each retaining protrusion 19 to be screwed to a screw hole 12 via a screwing hole 194. Thus the ball tray member and the cover member are integrally assembled preventing the retaining protrusion 19 from being drawn out. |
