Abstract: A coupler includes a first joint member, a holder, a second joint member, a sleeve, and a valve. The holder is attached to an outer circumference of the first joint member. The second joint member is detachably attached to the holder. The sleeve covers an outer circumferential surface of the holder and is displaceable by a first spring member. The valve is attached into the first joint member and changes the communication in the first joint member.

Abstract: A coupler includes a first joint member, a holder, a second joint member, a sleeve, and a valve. The holder is attached to an outer circumference of the first joint member. The second joint member is detachably attached to the holder. The sleeve covers an outer circumferential surface of the holder and is displaceable by a first spring member. The valve is attached into the first joint member and changes the communication in the first joint member.

Abstract: An O-ring is disposed on a front end surface of an abutted collar to prevent a fluid from leaking out of a flow passage when a socket and a plug of a tube joint is coupled to one another. A check valve of each of the socket and the plug, which prevents an outflow of the fluid when the socket and the plug are disengaged from each other, comprises the cylindrical collar (plug body) and a valve element. The valve element is disposed toward an inner diameter of the collar. The valve element has an O-ring disposed on the outer circumference of a columnar section coaxial with the collar.

Abstract: A tube joint comprises a first tube joint member; a second tube joint member joined to the first tube joint member; a sleeve attached to a joining portion of the first and second tube joint members, for joining and releasing the first and second tube joint members; a resilient member for urging the sleeve in the direction to join the first and second tube joint members to one another; and a protecting member for protecting the sleeve.

Abstract: An O-ring is disposed on a front end surface of an abutted collar to prevent a fluid from leaking out of a flow passage when a socket and a plug of a tube joint is coupled to one another. A check valve of each of the socket and the plug, which prevents an outflow of the fluid when the socket and the plug are disengaged from each other, comprises the cylindrical collar (plug body) and a valve element. The valve element is disposed toward an inner diameter of the collar. The valve element has an O-ring disposed on the outer circumference of a columnar section coaxial with the collar.

Abstract: A tube joint comprises a first tube joint member; a second tube joint member joined to the first tube joint member; a sleeve attached to a joining portion of the first and second tube joint members, for joining and releasing the first and second tube joint members; a resilient member for urging the sleeve in the direction to join the first and second tube joint members to one another; and a protecting member for protecting the sleeve.