Abstract: There are provided a rail 10 in which a rolling member rolling surface 11 is formed along the longitudinal direction, a block 20 in which a loaded rolling member rolling surface 27 is formed in an opening 25 comprising a through hole, a plurality of balls 70 disposed and housed between the rolling member rolling surface 11 and the loaded rolling member rolling surface 27 which circulate according to the relative motion of the rail 10 and the block 20. A sectional shape at right angles to the longitudinal direction of the rail 10 and a sectional shape of the opening 25 are formed into a mutually geometrically similar longitudinal shape. The block 20 is a box type with high rigidity. A contact angle of the ball 70 can be optionally changed by changing the positions alone of the rolling member rolling surface 11 and the loaded rolling member rolling surface 27 to be machined on one type of the block 20 and the rail 10.

Abstract: An open research and development method includes the steps of: sending membership solicitation information to a communications network from a predetermined server; causing an applicant for membership to report predetermined items from a network terminal operated by the applicant, by way of the communications network; performing examination operation on the reported information in connection with membership registration; registering the information about the applicant into a membership database on at least the condition that the applicant should have passed the examination operation; and accumulating, into a knowledge database, information which has been transmitted from members registered in the membership database by way of the communications network in relation to a specific topic.