Automatic injection device with audible indicator of completed injection

A device (1) for automatic injection of a product (6) into an injection site (7), the product being carried by a container (2) having an open proximal end (3) and a substantially closed distal end (4) carrying a needle (5) to provide an outlet port for the product from the container, and a piston (8) provided in the container and distally movable with respect to the container, the distal movement of the piston causing the product to be expelled from the container through the needle thereby realising the injection of said product, said device (1) comprising:

• a piston rod (9;
• 109;
• 209;
• 309;
• 409) intended to be coupled to said piston (8) in the distal direction during the injection,
• biasing means (18;
• 118;
• 218;
• 418) for causing distal movement of said piston rod (9;
• 109;
• 209;
• 309;
• 409) with respect to said container (2) during the injection,
• a housing (14;
• 214) designed for receiving at least partially said container (2), said piston rod (9;
• 109;
• 209;
• 309;
• 409) and said biasing means (18;
• 118;
• 218;
• 418),
• controlling means (13, 22;
• 110, 121, 117;
• 213, 214a, 215;
• 309, 321;
• 409, 421) designed for producing an audible indicator when said piston (8) is near said distal end (4) of the container (2) and the product (6) is substantially completely expelled from the container thereby providing an indication to a user that injection of the product is completed,
• said device (1) being characterized in that:
• said controlling means comprise at least one first element (13;
• 121;
• 213;
• 321;
• 421), being flexible or breakable and directly or indirectly coupled to said housing (14;
• 214) or to said piston rod (9;
• 109;
• 209;
• 309;
• 409), during the injection, and at least one second element (22;
• 110, 117;
• 214a, 215;
• 309;
• 409), said second element being coupled directly or indirectly to said piston rod (9;
• 109;
• 209;
• 309;
• 409) or to said housing (14;
• 214), during the injection, said first and second elements cooperating with each other at the end of injection under the effect of the said biasing means (18;
• 118;
• 218;
• 418) so as to produce said audible indicator.