Device for packaging and distributing a substance

A device for dispensing a product, comprising:

• a body;
• a sleeve movable relative to said body;
• a piston movable within said body and comprising a shaft coupled to said sleeve;
• a first coupling member between said shaft and said sleeve, said first coupling member having at least one extension engaged in an opening of said body, wherein said extension is movable within said opening relative to said body over an angular range;
• and
• a second coupling member between said body and said sleeve, said second coupling member being rotatable relative to said body over said angular range and rotatable relative to said sleeve beyond said angular range.

A device for dispensing a product, comprising:

• a body;
• a sleeve movable relative to said body;
• a piston movable within said body;
• and
• a piston driving mechanism comprising a first part and a second part, wherein:
• the first part comprises a screw having an end coupled to said piston and at least one longitudinal finger having an end coupled to said piston,
• the second part comprises an internally threaded hollow shaft, said screw being engaged in said internally threaded hollow shaft, the second part further comprising a collar coupled to said sleeve, and
• said longitudinal finger passes through an opening of a transverse wall of said body, said longitudinal finger being movable within said opening over an angular range so that said first part is rotatable relative to said body over said angular range.