Abstract: Percussion device for triggering the primer of a blasting charge of an actuation device. It comprises a striker (4) moveably housed and retained in a support (1), as well as a helical traction spring (7) of which one end (8) is secured to the striker. The other end (9) of the spring (7) is provided with a hook member (10) allowing to maintain the spring in a tensioned state and to suddenly release the spring to cause the percussion by spring contraction. The invention is particularly applicable to devices to sever cables, for example on boats, in case of dismasting.

Abstract: The invention relates to a disposable syringe which is not able to be used more than once for carrying out an injection.To this end, the syringe comprises means which permit the rearward return of at least a part of the piston body to be prevented when the said body occupies a position close to its position of maximum insertion in the cylinder. These means can, for example, be formed by a circular groove, in which can be engaged a peripheral rim of a resilient member integral with the body of the piston, thus causing the blocking of the said body.Applications are particularly in human and veterinary medicines.