Injection device

1. An injection device, comprising:

a housing having a distal end and a proximal end and an abutment surface provided near the proximal end of the housing, the abutment surface extending at least partially around a perimeter of the housing and facing away from the distal end and at least one engagement structure provided at the abutment surface;

a cap removably attached to the proximal end of the housing and having a proximal end and a distal end with an opening at the distal end of the cap, wherein internal dimensions of the opening correspond to outer dimensions of the proximal end of the housing, thereby allowing the cap to slip onto the proximal end of the housing;

and a first lifting pole pivotally arranged within the cap, the first lifting pole being pivotally connected to the cap at a proximal end of the first lifting pole by a pivotal connection and being arranged to bear against the abutment surface at a distal of the first lifting pole when the cap is in a fully attached position on the housing; wherein the first lifting pole extends from the abutment surface to the pivotal connection to the cap along an axis inclined relative to a longitudinal axis of the housing when the cap is in the fully attached position;

wherein relative rotational movement between the cap and the housing in a first direction around the longitudinal axis causes the distal end of the first lifting pole to engage with the at least one engagement structure and alignment of the first lifting pole with the longitudinal axis of the housing, thereby causing axial displacement of the cap relative to the housing toward a detached position of the cap.

2. The injection device of claim 1 , further comprising a second lifting pole.

3. The injection device of claim 2 , wherein the first and second lifting poles extend along axes, one of which is positively inclined to the longitudinal axis of the housing and the other of which is negatively inclined to the longitudinal axis of the housing when the cap is in the fully attached position.

4. The injection device of claim 3 , comprising two first and two second lifting poles.

5. The injection device of claim 3 , wherein pivotal connections of the first and second lifting poles are arranged to bias the first and second lifting poles respectively toward positively and negatively inclined positions.

6. The injection device of claim 2 , wherein the first and second lifting poles are molded into the cap.

7. The injection device of claim 1 , further comprising a needle shield for receiving a needle attached to the proximal end of the cap.

8. The injection device of claim 7 , wherein the needle shield is rotatable in relation to the cap.

9. The injection device of claim 1 , wherein the abutment surface extends around the whole perimeter of the housing, and a plurality of the engagement structures are provided on the abutment surface evenly distributed along the perimeter of the housing.

10. The injection device of claim 9 , wherein the engagement structures comprise protrusions extending from the abutment surface in a direction away from the distal end of the housing.

11. The injection device of claim 9 , wherein the engagement structures comprise recesses in the abutment surface.

12. The injection device of claim 1 , wherein the injection device is a disposable injector.

13. The injection device of claim 1 , wherein the injection device is a reusable injector.