Abstract: The invention relates to an injection device (100, 200, 300) which is capable of resisting proximal movements of a piston rod (107, 207, 307) relative to a housing (102, 202, 302), when the piston rod (107, 207, 307) is subjected to proximally directed forces below a threshold magnitude, and of allowing reversible proximal movements of the piston rod (107, 207, 307) relative to the housing (102, 202, 302), when the piston rod (107, 207, 307) is subjected to proximally directed forces of or above the threshold magnitude.

Abstract: The invention relates to an injection device (1, 100) configured to perform automatic priming upon removal of a protective cap (15, 115) from a cap receiving portion (9, 109) of a housing (2, 102). When mounted on the injection device (1, 100) the cap (15, 115) defines a first position for a drive member (10, 110) relative to the housing (2, 102), which drive member (10, 110) is capable of causing a piston rod (7, 107) to advance a piston (8, 108) in a reservoir (4, 104). Means (13, 120) are provided defining a second position for the drive member (10, 110) relative to the housing (2, 102). During removal of the cap (15, 115) from the cap receiving portion (9, 109) the drive member (10, 110) moves from the first position to the second position under the influence of a spring (11, 111), thereby causing the piston rod (7, 107) to pressurize the reservoir (4, 104).

Abstract: The invention relates to an injection device (100, 200, 300) which is capable of resisting proximal movements of a piston rod (107, 207, 307) relative to a housing (102, 202, 302), when the piston rod (107, 207, 307) is subjected to proximally directed forces below a threshold magnitude, and of allowing reversible proximal movements of the piston rod (107, 207, 307) relative to the housing (102, 202, 302), when the piston rod (107, 207, 307) is subjected to proximally directed forces of or above the threshold magnitude.

Abstract: The invention relates to an injection device (1, 100) configured to perform automatic priming upon removal of a protective cap (15, 115) from a cap receiving portion (9, 109) of a housing (2, 102). When mounted on the injection device (1, 100) the cap (15, 115) defines a first position for a drive member (10, 110) relative to the housing (2, 102), which drive member (10, 110) is capable of causing a piston rod (7, 107) to advance a piston (8, 108) in a reservoir (4, 104). Means (13, 120) are provided defining a second position for the drive member (10, 110) relative to the housing (2, 102). During removal of the cap (15, 115) from the cap receiving portion (9, 109) the drive member (10, 110) moves from the first position to the second position under the influence of a spring (11, 111), thereby causing the piston rod (7, 107) to pressurise the reservoir (4, 104).