A method of securing an injection needle in a flexible tube.

This invention is concerned with a method of securing an injection needle in a flexible tube, for an injector for medical, lubrication or other purposes.

There is a known kind of injector which comprises a pressurised ampoule, in the form of a small glass bottle with an elongate readily-frangible neck, a plastics. flexible tube having one end portion sealingly fitted over the bottle neck, and a metal injection needle mounted in, and projecting from, an opposite end portion of the tube. The needle is held in the tube by a plastics plug, which both retains the needle and seals the space between the tube and the needle. In use of this known injector, the neck of the bottle is broken to discharge a liquid (to be injected) from the bottle into the tube and so out through the needle.

That known injector is just one kind of injector in which an injection needle is mounted in a flexible tube, and other kinds of injector, for medical or other purposes, may employ similar arrangements.

The use of a plastics plug to mount the needle in the tube has been found to be disadvantageous.in various ways but in particular manufacture and insertion of the plug., to give a reliable seal, can be troublesome. Furthermore, difficulties can arise with the needle picking up plastics material from the plug during assembly of the needle with the plug. It is an object of the present invention to provide an improved method of securing an injection needle in a flexible tube.

The invention is characterised 'in that an end portion of the needle is inserted into the tube and a clamping band is crimped around the tube to compress the tube to secure the needle and seal the tube around the needle.

The tube may conveniently be of a plastics material but could be of any suitable material which will allow the tube to be appropriately deformed in the crimping process and seal against the needle. The band can also be of any suitable material, though some metals may be found to be the most satisfactory materials. The band may or may not be in the form of a continuous loop.

An injector and its manufacture will now be described, with reference to the accompanying drawing of the injector, to illustrate the invention by way of example.

The injector comprises a steel injection needle 10 inserted in, and projecting from, one end portion of a plastics flexible tube 12, and a pressurised ampoule, in the form of a sealed glass bottle 14, containing a liquid to be injected. The bottle comprises an elongate readily-frangible neck portion 16 over which an opposite end portion of the tube is sealingly fitted; in use of the injector the neck portion 16 can be broken to discharge the liquid from the bottle into the tube 12 and so out through the needle 10.

To retain the needle securely in the tube, and to seal between the tube and the needle, a metal band 18 is, in manufacture of the injector, placed around the tube and crimped to compress the tube against the needle.

Other embodiments of the invention could be for use in injecting lubricants, for example for use by a watch- maker, or other liquids.