TW201304831A - Injection system and actuating device for attachment to a pen-injector to form such injection system - Google Patents

Abstract

Injection system (1) comprising a pen-injector (2) including: a shell (3) having an elongated outer surface and proximal and distal sections, and an actuator (10) slidably mounted on the proximal section of the shell (3), wherein said injection system further comprises an actuating device (15) comprising: a lever (30) pivotally connected to the proximal section of the shell (3) and adapted to cover and press at least a part of the actuator (10) when actuated by a patient, a holding member (50) radially protruding from the outer surface of the shell (3) and adapted to bear on a patient's finger (61) while enabling the patient to actuate the lever (30) with another finger (62).

Description

An injection system and an actuation device for attachment to a pen-type injection device to form the injection system

The present invention is directed to an injection system and an actuation device for attachment to a pen-type injection device to form the injection system.

In particular, the present invention relates to an injection system containing a pen-type injection device for the patient to easily inject a product (especially a therapeutic or pharmaceutical product) to the patient itself.

More particularly, the present invention relates to an injection system including a pen type injection device including a housing and an injection mechanism for housing a container of a product to be injected, the injection mechanism being used for A dose of product is expelled from the container; the outer casing has an elongated outer surface extending along the central axis and has a proximal section and a distal section. The pen-type injection device also includes an actuator for actuating the injection mechanism, the actuator being slidably mounted on the proximal section of the housing along a central axis.

Conventional pen-type injection devices are almost incapable of being moved by patients or children whose dexterity is limited, especially by patients suffering from arthritis (especially rheumatoid arthritis). Therefore, it is impossible or difficult for such patients to inject the product into themselves using a conventional pen-type injection device.

The object of the present invention is to solve the above problems.

For this purpose, according to a first aspect of the invention, the invention provides An injection system of the type further includes an actuation device comprising: a lever pivoted to a proximal section of the housing by a pivotal connection having a pivot axis, the pivot axis being substantially perpendicular to the housing a central axis adapted to cover and press at least a portion of the actuator when the patient actuates the lever, the gripping member being at an axial distance from the pivot from the outer casing The outer surface projects radially, the gripping member being adapted to abut against a patient's finger while enabling the patient to actuate the lever with another finger.

Thus, the pen-type injection device can be held in the open hand of the patient, in particular in the palm of the patient, with the grip member resting against one finger and the lever being held by another finger (especially The thumb) moves with a limited amount of force. The actuation device makes it easy to hold and actuate the pen-type injection device, even if it is held and actuated by a patient with limited dexterity. This allows the patient to self-inject the product to be injected.

The grip member can include a curved tab having a recess that turns in a distal direction.

The rod is moveable in a radial plane containing the central axis and is movable in a direction in which the grip member extends, the pivotal connection and the gripping member being located on the same side of the central axis in the radial plane on.

In an embodiment, the lever member can be directly pivotally attached to the proximal section of the outer casing, and the grip member can be integrally formed with the outer casing.

In another embodiment, the actuation device can additionally include a body extending along the longitudinal axis and coaxially attached to the outer surface of the outer casing, the lever being pivotally coupled to the proximal portion of the body.

The body of the actuation device is releasably attached to the outer casing.

In particular, the body can be provided with a releasable attachment mechanism that engages the proximal side section of the outer casing.

The releasable attachment mechanism includes, for example, a collar that is coaxially snapped onto the outer surface of the outer casing of the pen-type injection device.

Furthermore, the grip member can be integrally formed with the body of the actuating device.

Further, the previously defined injection system may additionally comprise a container for the product to be injected and an injection mechanism housed within the housing containing a medicament for the treatment of arthritis.

According to a second aspect of the invention, the invention provides an actuating device for attachment to a pen-type injection device, the pen-type injection device having a housing and an actuator having an elongated outer surface extending along a central axis The actuator is slidably mounted along the central axis on a proximal section of the outer casing. The actuating device includes a body having a longitudinal axis and adapted to be coaxially attached to the outer surface of the outer casing, and a lever pivotally coupled to the proximal portion of the body by a pivotal connection, The pivotal connection has a pivot axis substantially perpendicular to the longitudinal axis, the lever being adapted to cover and press at least a portion of the actuator of the pen-type injection device when actuated by a patient; the grip member Radially projecting from the body at an axial distance from the pivotal connection, the gripping member being adapted to abut against a patient's finger while enabling the patient to actuate the lever with another finger.

The grip member can include a curved tab having a recess that turns in a distal direction.

The body may be provided with a releasable attachment mechanism adapted to engage the pen type note The proximal section of the housing of the firing device.

The releasable attachment mechanism includes, for example, a collar adapted to be snap-fitted to the outer surface of the outer casing of the pen-type injection device.

Further, the grip member may be integrally formed with the body.

Other objects and advantages of the invention will be apparent from the particular embodiments disclosed herein. These particular embodiments serve as non-limiting examples. This disclosure refers to the attached drawings.

In the drawings, the same reference numerals represent the same or similar elements.

Figures 1 to 4 represent a first embodiment of an injection system 1 which is used in particular by a patient to inject a dose of a therapeutic or pharmaceutical product, such as a drug or a drug.

In Figures 1 and 2, the injection system 1 comprises a pen-type injection device 2 having a generally cylindrical shape about a central axis A.

The pen type injection device 2 includes a cylindrical hollow outer casing 3 having a circular cross section. The outer casing 3 extends between the opposite proximal section 4 and the distal section 5 along a central axis A and presents an elongated inner surface 6 defining the casing 7 and an elongated outer surface 8 relative to the inner surface 6. The housing 7 is adapted to receive a container (not shown) for the product to be injected, and an injection mechanism (not shown) for discharging the product dose from the container. For example, the container and the injection mechanism together form a syringe that is received and retained within the housing 7 such that at least a portion of the needle of the syringe extends beyond the distal section 5 of the housing 3. In another embodiment, the injection mechanism can include a slidable mounting on the outer casing 3 along the central axis. The plug, and the needle secured to the outer casing 3, such that at least a portion of the needle extends out of the distal section 5 of the outer casing 3. In this other embodiment, a container can be disposed within the housing 7 to cooperate with an injection mechanism mounted on the housing 3.

To actuate the injection mechanism, a cylindrical actuator 10 having a circular cross section is mounted on the proximal section 4 of the outer casing 3. The actuator 10 extends between the lower surface 11 and the upper surface 12 along a central axis A; the lower surface 11 is disposed within the housing 7; the upper surface 12 projects from the proximal section 4 of the outer casing 3. The actuator 10 is mounted to slide along a stroke that extends along the central axis A. To actuate the pen-type injection device 2, the actuator 10 is lowered via the pressure exerted on its upper surface 12. The actuator 10 can then be resiliently biased or moved to an upright position for subsequent actuation.

The pen type injection device 2 disclosed in the present invention has a substantially cylindrical shape having a circular cross section, but the present invention is not limited thereto. The invention may have any other cross-section, such as an elliptical or polygonal shape, and more generally other shapes.

In order to easily hold and actuate the pen-type injection device 2, the injection system includes an actuation device 15.

In the first embodiment of Figures 1-4, the actuating device 15 is formed as a separate component and includes a body 16 mounted on the outer casing 3 of the pen-type injection device 2.

In Figure 3, the body 16 includes a collar 17 that surrounds the longitudinal axis B. In the embodiment represented, the collar 17 is cylindrical, in particular annular, around the longitudinal axis B. The collar 17 has an outer surface 19 and an inner surface 18 that defines an opening adapted to receive the pen-type injection device 2 for The collar 17 is fitted to the outer surface 8 of the outer casing 3. In order to improve the retention of the collar 17 on the outer casing 3, the inner surface 18 of the collar 17 and the outer surface 8 of the outer casing 3 may have complementary retaining mechanisms. In the representative embodiment, the complementary retainer forms the annular bead 20 on the inner surface 18 of the collar 17 and the annular groove 21 on the outer surface 8 of the outer casing 3.

Of course, the collar 17 (particularly its inner surface 18) may vary in shape and size to accommodate the shape and size of the outer surface 8 of the outer casing 3 of the pen-type injection device 2. Furthermore, although the cylindrical collar 17 is presented as being continuous to form an attachment element that fits along the central axis A of the pen-type injection device 2, the cylindrical collar 17 may be discontinuous, ie It is open in a direction perpendicular to the longitudinal axis B to form an attachment element that is assembled along the central axis A or that is clamped in a direction perpendicular to the central axis A.

The body 16 also includes a wall 25 that is disposed transversely to the longitudinal axis B and at a distance from the longitudinal axis B. In particular, the wall 25 is integrally formed with the collar 17 and extends from the collar 17 substantially along the longitudinal axis B to the proximal portion 26. The wall 25 is inclined relative to the longitudinal axis B and is remote from the longitudinal axis B. It should be noted that in other embodiments, the wall 25 may be straight along the longitudinal axis B, or the wall 25 may be part of the collar 17, and the proximal portion 26 is formed thereon.

The proximal portion 26 of the wall 25 supports the rod 30.

The rod 30 has a connecting end 31 and a free end 32 and presents a length between the connecting end 31 and the free end 32. The length of the rod 30 is greater than the transverse direction of the collar 17 (measured perpendicular to the longitudinal axis B) for reasons that can be understood from the description below; in the illustrated embodiment, the size corresponds to The diameter of the outer surface 19 of the collar 17. In the actuatable position shown in Figure 3, the rod 30 thus extends transversely with respect to the longitudinal axis B towards the longitudinal axis B and intersects the longitudinal axis B. The length of the rod member 30 is therefore greater than the transverse dimension of the pen-type injection device 2 measured perpendicular to the central axis A of the pen-type injection device 2; in the illustrated embodiment, this dimension corresponds to the diameter of the outer surface 8 of the outer casing 3. .

In Fig. 3, the rod 30 is bent between the connecting end 31 and the free end 32, and in the actuatable position of Fig. 3, presents a recess towards the collar 17. The lever member 30 has a lower surface 33 and an upper surface 34; the lower surface 33 faces the opening of the collar 17 in the actuatable position; the upper surface 34 is on the opposite side of the lower surface 33. The lower surface 33 is provided with a projection 35 in the form of a central button 36. The upper surface 34 is provided with a grip 37 (in the form of a transverse rib 38) disposed adjacent the free end 32 of the rod 30.

The lever 30 is pivotally mounted to the proximal portion 26 of the wall 25 by a pivotal connection. In a representative embodiment, the pivotal connection is a hinge 40 that includes a socket 41 extending along a pivot axis P and a pin 42 extending within the socket 41, the pivot axis P being substantially perpendicular to the longitudinal direction Axis B. In a representative embodiment, the socket 41 is attached to the proximal portion 26 of the wall 25 and the pin 42 is attached to the connection end 31 of the rod 30. In another embodiment, the attachment of the socket 41 and the pin 42 can be reversed.

In another variation, the lever member 30 can be coupled to the proximal portion 26 of the body 16 by a pivotal connection formed by the resiliently deformable portion and integral with both the lever member 30 and the wall member 25. Forming.

The body 16 additionally includes an arm 43 that is opposite the wall 25 from the collar 17 One side extends parallel to the longitudinal axis B. The arm 43 is intended to be in contact with the outer casing 3 of the pen-type injection device 2 and thus can be mated with the outer surface 8 of the outer casing 3. In particular, the arm 43 has an inner surface 44 that is curved about the longitudinal axis B and an outer surface 45 that is opposite the inner surface 44.

The grip member 50 and the arm 43 of the body 16 are integrally formed. The grip member 50 is provided such that when the actuating device 15 is mounted on the pen-type injection device 2, the patient can hold the pen-type injection device 2.

The grip member 50 is disposed at an axial distance from the pivotal connection 40 along the longitudinal axis B and projects from the outer surface 45 of the arm 43. In particular, the grip member 50 extends radially in the opposite direction to the longitudinal axis B with respect to the longitudinal axis B. In a representative embodiment, the grip member 50 has an end that is attached to the arm 43 and that is configured to be substantially aligned with the connecting end 31 of the rod 30 and the pivotal connection 40 along the longitudinal axis B. Due to this configuration, the rod 30 and the grip member 50 extend in the same radial plane, which includes the longitudinal axis B and the radial direction in which the grip member 50 extends, the pivot connection 40 and the grip member 50 in the diameter Arranged in the plane on the same side of the longitudinal axis B. Further, the lever member 30 and the grip member 50 in the actuatable position shown in FIG. 3 extend in opposite directions with respect to the longitudinal axis B. It should be noted, however, that the lever member 30 and the grip member 50 are disposed in any other suitable relative orientation so that the body 16 (and in particular the arm 43) is adaptable.

The shape and position of the grip member 50 is designed to be placed against the patient's finger while enabling the patient to actuate the lever 30 with another finger. The so-called "finger" means one of the five fingers of the hand (including the thumb). In this regard, the grip member 50 includes an arcuate fin 51. The flap 51 has There are opposing upper contact surfaces 52 and lower contact surfaces 53, and extend substantially laterally relative to the longitudinal axis B. The curvature of the flap 51 substantially matches the curvature of the patient's finger. The curvature of the flap 51 is advantageously in the recess 53A opposite the rod 30 so as to act as a lever when the lever 30 is pressed.

The grip member 50 of the present invention is not limited to being in the form of an arcuate fin 51. The grip member can be designed in any other suitable shape, for example the grip member can include one or more loops that form part of the loop.

As shown in FIG. 4, the body 16 of the actuation device 15 is coaxially attached to the outer surface 8 of the housing 3 of the pen-type injection device 2. In particular, the collar 17 is snap-fitted to the outer casing 3 of the pen-type injection device 2, the inner surface 19 of the collar 17 contacts the outer surface 8 of the outer casing 3, and the bead 20 of the collar 17 engages The groove 21 of the outer casing 3. The longitudinal axis B of the body 16 is coaxial with the central axis A of the pen-type injection device 2, and the proximal portion 26 of the body 16 is disposed adjacent the proximal section 4 of the outer casing 3.

In a representative embodiment, the collar 17 is snapped onto the proximal section 4 of the outer casing 3, although in other embodiments the collar can be fitted to any other portion of the outer casing 3. Thus, the wall 25 is sized to have a proximal portion 26 that is disposed adjacent the proximal section 4 of the outer casing 3.

As shown in Figures 1 and 2, once the actuation device 15 has been installed, the lever 30 is pivotally mounted (pivoted) in the vicinity of the housing 3 via the collar 17, wall 25, and pivot connection 40. On the side section 4. The pivotal connection 40 and the gripping member 50 are located on the same side of the radial plane in which the gripping member 50 and the rod 30 extend. Radial plane containing central axis A The pivot axis P is perpendicular to the central axis A of the pen type injection device 2. In the actuatable position, the lever 30 extends transversely with respect to the central axis A towards the central axis A. A connecting end 31 of the rod 30 is attached to a first side of the actuator 10 and a free end 32 of the rod 30 projects laterally relative to a second side of the actuator 10, the second side and the first side On opposite sides of the central axis A, respectively. The rod 30 covers the actuator 10 of the pen-type injection device 2 and contacts the upper surface 12 of the actuator 10 with a button 36; laterally measured relative to the central axis A, the free end 32 being disposed away from the actuator 10 distance. The rod 30 is moveable in a radial plane to actuate the actuator 10.

The inner surface 44 of the arm 43 of the actuator 15 contacts the outer surface 8 of the outer casing 3. The upper contact surface 52 and the lower contact surface 53 of the curved flap 51 extend substantially laterally with respect to the central axis A of the pen-type injection device 2, and the recess is turned in the distal direction, ie towards the distal section 5 of the outer casing 3.

As shown in Figures 6a, 6b, in order to inject the product contained in the container in the housing 7 of the pen-type injection device 2, the patient can hold the injection system 1 with his open hand 60. The curved flap 51 of the actuating device 15 abuts against the middle finger 61, and the lever 30 is pressed against the other side of the housing 3 by another finger (e.g., thumb 62) placed on the grip portion 37 of the member 30. Side section 4. Due to these configurations, the patient does not need to hold the hand 60 closed, and the pen type injection device 2 can be firmly grasped. Moreover, the free end 31 of the member 30 disposed at a distance from the actuator 10 reduces the force applied to move the actuator 10.

Although the present invention has disclosed an actuating device 15 that snaps onto the pen-type injection device 2, in other embodiments, the actuating device 15 can be permanently or removably attached to a pen-type injection in any other suitable manner. Device 2, the The body 16 is, for example, clamped, glued, or welded to the outer surface 8 of the outer casing 3. Further, the grip member 50 can be detached from the body 16, and the grip member and the body 16 are separately mounted on the outer casing 3, and the rod member 30 is articulated on the body 16.

Figure 5 shows a second embodiment of the injection system 1'.

In the second embodiment, the pen type injection device 2' is similar to the pen type injection device of the first embodiment, and the details will not be described. In Fig. 5, the elements of the second embodiment are similar to those of the first embodiment, given the same reference numerals and added a note of "'". These components are not described repeatedly. For details, please refer to the description already made.

The injection system 1' of the second embodiment differs from the injection system of the first embodiment primarily in the implementation of the actuation device 15' which forms an integrated assembly. In a second embodiment, the rod 30' is actually mounted directly on the proximal section 4' of the housing 3' of the pen-type injection device 2'; and is also shown in the form of an arcuate flap 51' The grip member 50' and the outer casing 3' of the pen type injection device 2' are integrally formed.

The connecting end 31' of the lever member 30' is pivotally mounted on the wall 25' and extends to the proximal portion 26' of the outer casing 3'. The wall 25' is disposed on the proximal section 4' of the outer casing 3'. Actuating device 15' includes, for example, a pivotally connected hinge 40'; the pivotal connection includes a socket 41' that extends along a pivot axis P', and a pin 42' that extends within the socket 41'. The socket 41' is mounted on the proximal portion 26' of the outer casing 3', and the pin 42' is mounted on the connecting end 31' of the rod member 30'. The attachment of the socket 41' and the pin 42' can be reversed.

The flap 51' protrudes from the outer surface 8' of the outer casing 3' and the upper contact surface 52' and lower contact surface 53' extend transversely relative to central axis A'.

The injection system 1' of the second embodiment operates in a similar manner to the injection system 1 of the first embodiment.

1,1’‧‧Injection system

2,2'‧‧‧ pen type injection device

3,3’‧‧‧ Shell

4,4’‧‧‧ proximal section

5,5’‧‧‧ distal section

6‧‧‧ inner surface

7‧‧‧Shell

8,8’‧‧‧ outer surface

10,10’‧‧‧ actuator

11‧‧‧ Lower surface

12‧‧‧ upper surface

15,15’‧‧‧Activity device

16‧‧‧Ontology

17‧‧‧ collar

18‧‧‧ inner surface

19‧‧‧ outer surface

20‧‧‧beads

21‧‧‧ slots

25,25’‧‧‧ wall

26,26’‧‧‧ proximal side

30,30’‧‧‧ rods

31, 31’ ‧ ‧ connection

32‧‧‧Free end

33‧‧‧ lower surface

34‧‧‧ upper surface

35‧‧‧ convex

36‧‧‧Center button

37‧‧‧ grip portion

38‧‧‧ transverse ribs

40,40’‧‧‧Pivot connection (hinge)

41,41’‧‧‧ Seat

42,42’‧‧ sales

43‧‧‧ Arm

44‧‧‧ inner surface

45‧‧‧ outer surface

50,50'‧‧‧ holding components

51,51’‧‧‧ (arc) fins

52, 52' ‧ ‧ upper contact surface

53A, 53A’‧‧‧ recess

53,53’‧‧‧ contact surface

60‧‧‧ hands

61‧‧‧ middle finger

62‧‧‧ Another finger

A, A’‧‧‧ central axis

B, B’‧‧‧ longitudinal axis

P, P’‧‧‧ pivot axis

1 is a perspective view of an injection system of a first embodiment of the present invention, the injection system including a pen type injection device and an actuation device including a lever member and a grip member attached to the assembly Figure 2 is a cross-sectional view of the injection system of Figure 1 in a longitudinal direction; Figure 3 is a side view of the actuation device of the injection system of Figure 1; Figure 4 is an exploded view of the injection system of Figure 1; 5 is a longitudinal sectional view of the injection system of the second embodiment of the present invention, the lever member of the actuating device is directly attached to the pen type injection device, and the grip member of the actuating device and the pen type injection device are integrally formed; FIG. 6a And 6b are perspective views of the use of the injection system of Fig. 1, exemplifying an injection system held by the patient's hand, with the gripping member resting against the middle finger of the patient while enabling the patient to actuate the lever with the thumb.

1‧‧‧Injection system

2‧‧‧ pen type injection device

3‧‧‧ Shell

10‧‧‧Actuator

15‧‧‧Actuating device

30‧‧‧ rods

50‧‧‧Bearing members

51‧‧‧ (arc) fins

60‧‧‧ hands

61‧‧‧ middle finger

62‧‧‧ Another finger

Claims (15)

An injection system comprising a pen-type injection device (2; 2'), the pen-type injection device comprising: a housing (3; 3') and an injection mechanism for housing a container of a product to be injected, the injection The mechanism is for expelling a dose of product from the container upon actuation, the outer casing (3; 3') having an elongated outer surface (8; 8') extending along a central axis (A; A') and having a near a side section (4; 4') and a distal section (5; 5'), and an actuator (10; 10') for actuating the injection mechanism, the actuator being along a central axis ( A; A') is slidably mounted on the proximal section (4; 4') of the outer casing (3; 3'), the injection system (1; 1 ') being characterized in that it additionally comprises an actuating device (15; 15'), the actuating device comprises: a lever (30; 30') pivotally connected to the housing by a pivotal connection (40; 40') having a pivot axis (P; P') The proximal section (4; 4') of (3; 3'), the pivot axis (P; P') being substantially perpendicular to the central axis (A; A') of the outer casing (3; 3'), When the patient actuates the rod (30; 30'), the rod (30; 30') is adapted to cover and press the stem At least a portion of the device (10; 10'), the grip member (50; 50'), at an axial distance from the pivotal connection (40; 40') from the outer surface of the outer casing (8; 8') projecting radially, the grip member (50; 50') is adapted to abut against a patient's finger (61) while enabling the patient to actuate the lever (30) with another finger (62); 30'). The injection system of claim 1, wherein the grip member (50) comprises a curved flap (51; 51') having a distal direction recess (53A; 53A'). An injection system according to claim 1 or 2, wherein the rod member (30; 30') is movable in a radial plane containing the central axis (A; A') and is engageable in the grip member ( 50; 50') moving in the direction of extension, the pivotal connection (40; 40') and the grip member (50; 50') being located in the same plane as the central axis (A; A') On the side. The injection system of claim 1 or 2, wherein the rod (30') is directly pivotally attached to the proximal section (4') of the outer casing (3'), and the grip member (50) ') and the outer casing (3') is integrally formed. An injection system according to claim 1 or 2, wherein the actuating device (15) additionally comprises a body (16) having an elongate axis (B) and coaxially attached to the outer casing (3) The outer surface (8) is pivotally attached to the proximal portion (26) of the body (16). The injection system of claim 5, wherein the body (16) of the actuation device (15) is releasably attached to the outer casing (3). The injection system of claim 5, wherein the body (16) is provided with a releasable attachment mechanism (17) that engages the proximal side section (4) of the outer casing (3). The injection system of claim 7, wherein the releasable attachment mechanism comprises a collar (17) that is coaxially fastened to the outer surface (8) of the outer casing (3). Such as the injection system of claim 5, wherein the grip structure The piece (50) and the body (16) of the actuating device (15) are integrally formed. An injection system according to claim 1 or 2, further comprising a container for the product to be injected and an injection mechanism housed in the outer casing (3; 3'), the container containing a drug for treating arthritis. An actuating device for attachment to a pen-type injection device (2) having a housing (3) and an actuator having an elongated outer surface extending along a central axis (A) (8) The actuator is slidably mounted on the proximal section (4) of the outer casing (3) along the central axis (A), the actuating device comprising: a body (16) having a longitudinal axis (B), and adapted to be coaxially attached to the outer surface (8) of the outer casing (3), a rod (30) pivotally connected to the body (16) by a pivotal connection (40) On the proximal portion (26), the pivotal connection (40) has a pivot axis (P) substantially perpendicular to the longitudinal axis (B), the lever (30) being adapted to cover when actuated by a patient And at least a portion of the actuator (10) that presses the pen-type injection device (2), the grip member (50) is at an axial distance from the pivotal connection (40) from the body (16) Radically protruding, the gripping member (50) is adapted to abut against a patient's finger (61) while enabling the patient to actuate the lever (30) with another finger (62). The actuating device of claim 11, wherein the grip member (50) comprises a curved flap (51) having a recess (53A) that turns in a distal direction. Actuating device of claim 11 or 12, wherein The body (16) is provided with a releasable attachment mechanism (17) adapted to engage the proximal section (4) of the outer casing (3) of the pen-type injection device (2). The actuating device of claim 13, wherein the releasable attachment mechanism comprises a collar (17) adapted to be snap-fitted to the outer casing (3) of the pen-type injection device (2) On the outer surface (8). The actuating device of claim 11 or 12, wherein the grip member (50) and the body (16) are integrally formed.