Intra-ruminal device

A method of assembling an intra-ruminal device, the method comprising:

• providing an intra-ruminal device comprising:
• a body substantially impervious to rumen fluids, the body defining a barrel having a first end and a second end, and an opening at the first end,
• at least one variable geometry device connected to and extending from the body to assist rumen retention,
• a dose of an active agent within the body to be accessible to rumen fluid via the first end, and
• a biasing arrangement within the body adapted to bias the active agent in the body towards the first end;
• loading the active agent into the barrel;
• attaching a cap located over the opening at the first end, the cap comprising an outlet in the top and having sidewalls that overlap a portion of the barrel to define an attachment zone, and located within the attachment zone is one or more protrusions and one or more corresponding weld cavities providing a localised point of contact between an outer wall of the barrel wall and an internal portion of the sidewall of the cap, wherein at least one of the one or more corresponding weld cavities comprises a void area formed between an inner surface of the cap side wall and the outer wall of the barrel in the attachment zone;
• and
• subjecting the attachment zone to ultrasonic vibrations to produce frictional heat energy at the one or more protrusions to substantially melt the one or more protrusions to form a weld between the one or more protrusions at at least one localised point of contact.

An intra-ruminal device, comprising:

• a body substantially impervious to rumen fluids, the body defining a barrel having a first end and a second end, and an opening at the first end,
• at least one variable geometry device connected to and extending from the body to assist rumen retention, a dose of an active agent within the body to be accessible to rumen fluid via the first end,
• a biasing arrangement within the body adapted to bias a plunger against the active agent in the body towards the first end, and
• a cap having a sidewall and top, the cap located over the opening at the first end and comprising an outlet in the top;
• wherein the sidewall overlaps a portion of the barrel to define an attachment zone, and located within the attachment zone is at least one protrusion that contacts with a substantially flat surface of the corresponding wall surface, the at least one protrusion providing a localised point of contact between an outer wall of the barrel and an internal portion of the sidewall of the cap to provide for an ultrasonic weld between the barrel and the cap at the attachment zone, wherein at least one of the at least one protrusions includes a corresponding weld cavity comprising a void area formed between an inner surface of the cap side wall and the outer wall of the barrel in the attachment zone.