Patent ID: 8900212

Claim:
A connection device, comprising: holding means spacing a syringe and a vial from each other or bringing the syringe and the vial close to each other; and a double-head cannula provided between lid members attached to the syringe and the vial for penetrating the lid members, wherein: the connection device is configured to switch from a pre-use state in which the holding means spaces the syringe and the vial from each other and the double-head cannula does not penetrate the lid members of the syringe and the vial, to a use state in which the holding means brings the syringe and the vial close to each other and the double-head cannula penetrates the lid members of the syringe and the vial to establish communication between internal spaces of the syringe and the vial, the holding means is composed of a syringe holding member to be attached to the syringe, and a cannula holding member which includes the double-head cannula, is located at a retracted position retracted with resect to the syringe holding member in the pre-use state, and is advanced to an advanced position abutting on the syringe holding member in the use state, the connection device further comprises separation preventing means which engages the syringe to prevent separation of the syringe from the syringe holding member when the cannula holding member is located at the retracted position, and releases an engagement state with the syringe to permit the separation of the syringe from the syringe holding member when the cannula holding member is located at the advanced position, the syringe holding member and the syringe are connected by screwing, and the separation preventing means is provided to the cannula holding member, and when the cannula holding member is located at the retracted position in the pre-use state, the separation preventing means engages the syringe to prevent rotation of the syringe and the syringe holding member, and when the cannula holding member is located at the advanced position in the use state, the separation preventing means releases the engagement state to permit the rotation of the syringe and the syringe holding member.