US Patent 8083734 Coolant dosing device

The invention relates to a coolant dosing device for the application of cryogenic gas for producing low temperatures as required e.g. in cryosurgery. The invention aims to ensure a disturbance-free operation in spite of often dirty gas and to exclude possible operating errors in the connection of capsules of the prior art. According to the invention, the coolant dosing device comprises a capillary tube that receives gas that has been filtered in the capsule and directly supplies it to the dispenser, thereby ensuring a disturbance-free operation. The low force connection between the capsule and the metering device by means of O-rings that are slipped over ensures a tight seal and an error-free operation.