Method and apparatus for vibration welding of thermoplastic components

Apparatus for forming a vibratory welded connection between end faces of first and second members and a junction piece, said members and said junction piece being composed at least in part of a thermoplastic material, and said junction piece comprising a first portion having a planar flange to be welded to the end faces of said first and second members and a second portion extending from and for supporting said first portion and comprising a removable tab that is an extension of said planar flange, said apparatus comprising:

• a) a vibratory head including a drive for vibrating said head in a predetermined plane at an amplitude of at least 0.4 mm and at a frequency of from 50 to 500 Hz;
• b) opposed first and second fixtures each having clamping structure for securing thereon a respective one of said first and second members so that said first and second members are supported so as to be movable independently of said vibratory head;
• c) a third fixture, connected to said vibratory head, configured to hold said removable tab of said second portion of said junction piece, and positioned to allow said first portion to engage said end faces and said planar flange of said first portion to extend at an angle with respect to each of said first and second members when said removable tab of said second portion is held by said third fixture;
• d) guide structure for guiding relative movement between said members and said junction piece in a direction perpendicular to said end faces such as to facilitate engagement between opposite sides of said junction piece and said first and second members respectively;
• e) pressure actuators coupled to said first and second fixtures to provide an engagement force between opposite sides of said junction piece and said first and second members;
• and
• f) a control system to regulate the operation of the vibration welding apparatus.