Floating joint and ultrasonic vibration joining apparatus

A floating joint comprising a first connection and a second connection in which the first connection and the second connection are coupled with each other, wherein:

• said first connection includes:
• a shaft body, and
• a spherical portion for contact whose bottom surface is coupled with a tip of said shaft body and whose surface has a convex hemi-spherical shape coaxial with a longitudinal axis of the shaft body, said spherical portion for contact having a bottom surface exposed region being a part of the bottom surface of said spherical portion for contact protruding outward from an outer circumference of the tip of said shaft body,
• said second connection includes:
• a frame body having a recessed space that receives said spherical portion for contact, said recessed space accommodating the spherical portion for contact, said frame body having a bottom surface portion having a flat plate shape serving as a bottom surface of said recessed space and a side surface portion serving as a side surface of said recessed space, and said side surface portion having a shaft body facing region facing said shaft body,
• said shaft body is configured such that a first connection object is attachable thereto by screwing and said frame body is configured such that a second connection object is attachable thereto by screwing,
• said floating joint further comprises:
• a fixing member coupled with said frame body in said shaft body facing region and having a bottom surface facing region facing said bottom surface exposed region;
• and
• a pressure adjusting member provided between said bottom surface exposed region of said spherical portion for contact and said bottom surface facing region of said fixing member without a gap, and having elasticity,
• a single-point spherical contact relationship in which only a center point defined at an apex of said convex hemi-spherical shaped surface of said spherical portion for contact is in contact with a part of the flat plate shape of said bottom surface portion of said frame body is maintained, by an elastic power of said pressure adjusting member, and
• said spherical portion for contact has no other contact relationship with the flat plate shape of said bottom surface portion of said frame body other than said single-point spherical contact relationship by the center point of said spherical portion for contact.