Abstract: Large vibration tool, vibrating at ultrasonic frequency, especially for applications in the welding, joining or cutting of materials, especially thermoplastics, in cleaning or emulsifying by the activation of a liquid medium, in gas spraying or in shot blasting by blasting any kind of medium, made in the form of a circular sonotrode hollowed out at its center so as to produce a cavity allowing a shape approaching that of a bell to be obtained, said tool having a linking mass providing surface coupling with a vibrational excitation element; at least one circular membrane vibrationally excited at its center or at one end; and at least one tube-shaped final element, the end of which defines the working area of the sonotrode, linked to the linking mass via the said membrane, the latter transmitting the vibration to the said final element whose length is defined by a longitudinal vibration mode tuned to the said excitation frequency.

Abstract: Method of heating by emission of electromagnetic radiation, wherein at least one emitting source is arranged extending in the form of a resistive element matching as close as possible the geometry formed by the joint lines of the thermoplastic components to be joined together with a reflecting zone conforming likewise to the profile of the resistive element, then an energy source, such as, especially, an electric current, is caused to pass inside the said emitting source so as to cause, by the Joule effect and by focusing the released radiation onto the reflective surfaces, possibly coated with a metal film, a surface layer of material at the interface of the said components to melt, and then the radiating source is set back in a position which does not interfere with the joining of the components.

Abstract: Device for causing epicycloid vibration, characterized in that it comprises at least one shaft secured by one of its ends to a bed connected by elastic means to the frame of the machine and furthermore supporting a thermoplastic component, the said shaft being provided at this end with a magnetic outgrowth, which when made to rotate inside a plurality of magnetic fields brought about by switching on a plurality of electromagnets located about the said shaft, generates an epicycloid-type movement of the bed, the other free end of the shaft being, on the one hand, guided in rotation within the frame of the machine and, on the other hand, driven in rotation by a motor.

Abstract: A compound sonotrode for an ultrasonic welding tool includes a carrier block or adaptor mounted on an ultrasonic machine, and secondary sonotrodes or concentrators fixed to the carrier block by pins tuned to the resonance frequency of the assembly, so as not to disturb the vibratory mode of operation of the compound sonotrode.