(19)
(11)EP 2 355 879 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
23.03.2016 Bulletin 2016/12

(21)Application number: 09826455.9

(22)Date of filing:  17.11.2009
(51)International Patent Classification (IPC): 
A61M 5/48(2006.01)
A61M 5/315(2006.01)
A61M 5/24(2006.01)
A61M 5/20(2006.01)
(86)International application number:
PCT/US2009/006146
(87)International publication number:
WO 2010/056367 (20.05.2010 Gazette  2010/20)

(54)

ADDITIVE FORCE DEVICE FOR DRUG DELIVERY PEN FOR INTRADERMAL MEDICATION INJECTION

ZUSÄTZLICHE KRAFTEINWIRKUNGSVORRICHTUNG FÜR EINEN WIRKSTIFFFREISETZUNGSSTIFT FÜR INTRADERMALE ARZNEIMITTELINJEKTION

DISPOSITIF DE FORCE ADDITIONNELLE DESTINÉ À UN STYLO DE DISTRIBUTION DE MÉDICAMENTS POUR UNE INJECTION INTRADERMIQUE DE MÉDICAMENTS


(84)Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

(30)Priority: 17.11.2008 US 193314 P

(43)Date of publication of application:
17.08.2011 Bulletin 2011/33

(73)Proprietor: Becton Dickinson and Company
Franklin Lakes, NJ 07417-1880 (US)

(72)Inventor:
  • BANIK, Robert
    Long Valley NJ 07853 (US)

(74)Representative: von Kreisler Selting Werner - Partnerschaft von Patentanwälten und Rechtsanwälten mbB 
Deichmannhaus am Dom Bahnhofsvorplatz 1
50667 Köln
50667 Köln (DE)


(56)References cited: : 
EP-A2- 0 338 806
US-A- 5 961 495
US-A1- 2006 173 439
US-A1- 2008 243 087
WO-A1-2006/045528
US-A1- 2006 106 362
US-A1- 2006 173 439
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Field of the Invention



    [0001] The present invention relates generally to a drug delivery pen for an intradermal medication injection. More particularly, the present invention generally relates to an additive force device for a drug deliver pen that facilitates intradermal medication injection. Still more particularly, the present invention is defined in claim 1 and provides a drug delivery pen having an additive force device that supplies additional injection force to the pen knob of the drug delivery pen to facilitate an intradermal high pressure injection of medication.

    Background of the Invention



    [0002] Insulin and other injectable medications are commonly given with drug delivery pens, whereby a disposable pen needle assembly is attached to facilitate drug container access and allow fluid egress from the container through the needle into the patient.

    [0003] As technology and competition advance, driving the desire for shorter, thinner, less painful, and more efficacious injections, the design of the pen needle assembly and parts thereof becomes more and more important. Designs need to proactively address ergonomically improving injection technique, injection depth control and accuracy, the ability to be safely used and transported to disposal, and protection against misuse while maintaining the ability to be economically manufactured on a mass production scale.

    [0004] The assembly and operation to a typical drug delivery pen, as shown in FIGS. 1 and 2, is described in U.S. Patent Application Publication No. 2006/0229562, published on October 12, 2006 and in U.S. Patent No. 6,248,095, issued on June 19, 2001.

    [0005] Drug delivery pens, such as the exemplary drug delivery pen 100 shown in FIGS. 1 and 2, are designed for subcutaneous injections and typically comprise a dose knob/button 24, an outer sleeve 13, and a cap 21. The dose knob/button 24 allows a user to set the dosage of medication to be injected. The outer sleeve 13 is gripped by the user when injecting medication. The cap 21 is used by the user to securely hold the drug delivery pen 100 in a shirt pocket, purse or other suitable location and provide cover/protection from accidental needle injury.

    [0006] FIG. 2 is an exploded view of the drug delivery pen 100 of FIG. 1. The dose knob/button 24 has a dual purpose and is used both to set the dosage of the medication to be injected and to inject the dosed medicament via the leadscrew 7 and stopper 15 through the medicament cartridge 12, which is attached to the drug delivery pen through a lower housing 17. In standard drug delivery pens, the dosing and delivery mechanisms are all found within the outer sleeve 13 and are not described in greater detail here as they are understood by those knowledgeable of the prior art. The distal movement of the plunger or stopper 15 within the medicament cartridge 12 causes medication to be forced into the needle 11 of the hub 20. The medicament cartridge 12 is sealed by septum 16, which is punctured by a septum penetrating needle cannula 18 located within the hub 20. The hub 20 is preferably screwed onto the lower housing 17, although other attachment means can be used, such as attaching to the cartridge. To protect a user, or anyone who handles the pen injection device 100, an outer cover 69, which attaches to the hub 20, covers the hub. An inner shield 59 covers the patient needle 11 within the outer cover 69. The inner shield 59 can be secured to the hub 20 to cover the patient needle by any suitable means, such as an interference fit or a snap fit. The outer cover 69 and the inner shield 59 are removed prior to use. The cap 21 fits snugly against outer sleeve 13 to allow a user to securely carry the drug delivery pen 100.

    [0007] The medicament cartridge 12 is typically a glass tube sealed at one end with the septum 16 and sealed at the other end with the stopper 15. The septum 16 is pierceable by a septum penetrating cannula 18 in the hub 20, but does not move with respect to the medicament cartridge 12. The stopper 15 is axially displaceable within the medicament cartridge 12 while maintaining a fluid tight seal.

    [0008] The backpressure in subcutaneous injections is not very large, while the backpressure associated with intradermal injections may be many times greater than that of subcutaneous injections. For example, the backpressure often exceeds 200 psi for an intradermal injection, while the backpressure for a subcutaneous injection is generally in the range of 30 - 50 psi. Thus, a need exists for a drug delivery pen that has a high mechanical gain to reduce thumb forces required to overcome the initial high breakout force in the cartridge during an intradermal injection.

    [0009] Existing intradermal drug delivery devices require a large force to inject the medication because of back pressure created from the intradermal layer, thereby making the intradermal injection difficult. Therefore, a need exists for a drug delivery pen that has an additive force device to add to the user's input force of depressing the injection button to allow an intradermal injection to be made with a low user force.

    [0010] Accordingly, a need exists for a drug delivery pen that facilitates intradermal medication injection.

    [0011] EP 0 338 806 A2 discloses a drug delivery pen having an internal torsion spring to help the user to inject the dose set.

    Summary of the Invention



    [0012] In accordance with the present invention defined in claim 1, an additive force device in combination with a drug delivery device is provided that supplies additional force during an injection by adding force to the user's force, thereby facilitating the intradermal medication injection.

    [0013] The additive force device includes an energy storage device, such as a torsion spring or a compression spring, used with a drug delivery pen, or other similar device, to aid a user during an injection by supplying additional force to a plunger of the drug delivery pen. Preferably, the additional force is supplied when a preset force is exceeded. The additive force device is loaded with a twist of a barrel, and then the dose is set on the drug delivery pen. The drug delivery pen is then used in its normal manner. When the force exerted by the user rises above a predetermined value, for example, five pounds or any other suitable ergonomic value, a mechanism releases the energy stored in the energy storage device to turn the pen's mechanism to effectively add force to the force exerted by the user.

    [0014] Objects, advantages, and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

    Brief Description of the Drawings



    [0015] The above benefits and other advantages of the various embodiments of the present invention will be more apparent from the following detailed description of exemplary embodiments of the present invention and from the accompanying figures, in which:

    FIG. 1 is a perspective view of an assembled drug delivery pen;

    FIG. 2 is an exploded perspective view of the components of the drug delivery pen of FIG. 1;

    FIG. 3 is a perspective view in cross section of an additive force device for a drug delivery pen for intradermal medication injection;

    FIG. 4 is an exploded perspective view of the additive force device of FIG. 3;

    FIG. 5 is a front elevational view of the additive force device of FIG. 3 prior to a dose being set;

    FIG. 6 is a front elevational view in partial cross section of the additive force device of FIG. 5;

    FIG. 7 is a perspective view of the additive force device of FIG. 5;

    FIG. 8 is a perspective view of the additive force device of FIG. 3 after a dose has been set;

    FIG. 9 is an exploded perspective view of the additive force device of FIG. 3;

    FIG. 10 is an illustration of the force input by a user and the resulting output force generated by a conventional drug delivery pen;

    FIG. 11 is an illustration of the force input by a user and the resulting output force generated by a drug delivery pen to which an additive force device according to an exemplary embodiment of the present invention has been connected;

    FIG. 12 is a table of the user input force and the resulting output force generated by a conventional drug delivery pen;

    FIG. 13 is a table of the user input force and the resulting output force generated by a drug delivery pen to which an additive force device according to an exemplary embodiment of the present invention has been connected;

    FIGS. 14 - 16 are side and front elevational views and a perspective view of a torsion spring;

    FIGS. 17 and 18 are elevational views of a additive force device of FIG. 3 connected to a drug delivery pen;

    FIGS. 19 and 20 are exploded perspective views of the additive force device and drug delivery pen of FIGS. 17 and 18;

    FIGS. 21 and 22 are side elevational views of the additive force device connected to a drug delivery pen of FIGS. 17 and 18;

    FIG. 23 is a side elevational view in cross section of the additive force device and drug delivery pen of FIG. 22;

    FIG. 24 is an enlarged elevational view in cross section of the additive force device of FIG. 23; and

    FIG. 25 is an enlarged elevational view in cross section in which the additive force device of FIG. 24 is rotated approximately 90 degrees.



    [0016] Throughout the drawings, like reference numbers will be understood to refer to like parts, components and structures.

    Detailed Description of the Exemplary Embodiments



    [0017] The following description and details of exemplary embodiments of the present invention are disclosed with reference to a typical drug delivery pen 100, as shown in FIGS. 1 and 2. However, the additive force device of the present invention may be used with any suitable drug delivery pen. The pen may be provided with a subcutaneous patient needle 11 as shown or with a shorter (approximately between 0.5 - 3 mm and preferably approximately between 1.5 - 2 mm) intradermal patient needle.

    [0018] In the exemplary embodiment of the present invention shown in FIGS. 3 - 25, the additive force device 111 is connected to an existing drug delivery pen 100 (FIGS. 1 and 2), as shown in FIGS. 17 - 25. An additive force device 111 is connectible with a drug delivery pen 100 to increase the amount of force exerted by a user on the pen knob 24 to facilitate injection. The additive force device 111 includes a first spring 121 and a loading barrel 135 connected to the first spring 121 for storing torque therein. A ratchet assembly 129 is connected to the loading barrel 135 and to the first spring 121. The ratchet assembly has a first position in which torque is stored in the first spring 121 and a second position in which torque is released from the first spring 121. An inner barrel 133 is connected to the ratchet assembly and to the drug delivery pen 100. The inner barrel 133 transmits the stored torque from the first spring 121 to the drug delivery pen 100 to increase an injection force thereof.

    [0019] The additive force device 111 includes a button 161 connected to a loading barrel 135. A lower ratchet 151 is connected to the loading barrel 135. An upper ratchet 125 is connected to the lower ratchet 151. A first spring 121 is disposed between the loading barrel 135 and the upper ratchet 125. The upper ratchet 125 is connected to an inner barrel 133. A second spring 127 is disposed between the inner barrel 133 and the lower ratchet 151. An outer barrel 131 is connected to the inner barrel 133 and to the knob 24 of the drug delivery pen 100. A fixing barrel 145 is connected to the outer barrel 131 and to the drug delivery pen 100.

    [0020] The button 161 has a substantially planar outer surface 163, as shown in FIG. 19. A protrusion 167 extends outwardly from an inner surface 165. A circumferential rib 169 extends around the protrusion, as shown in FIG. 20. The circumferential rib 169 facilitates securing the button 161 to the lower ratchet 151.

    [0021] The loading barrel 135 has an inner wall 181 and an outer wall 183. A groove 184 extends axially along an inner surface of the inner wall 181 and receives the rib 153 of the lower ratchet 151, thereby keying the loading barrel 135 to the lower ratchet 151. Preferably, a second groove is disposed diametrically opposite the first groove 184 to receive the second rib of the lower ratchet 151.

    [0022] The ratchet assembly 129 includes a lower ratchet 151 and an upper ratchet 125. The lower ratchet 151 has a base 155 and a shaft 157 extending outwardly therefrom. A rib 153 extends axially along an outer surface of the shaft 157. Preferably, a second rib is diametrically opposed to the rib 153. A plurality of teeth 158 are disposed on an upper surface of the base 155.

    [0023] The upper ratchet 125 has a base 191. A plurality of teeth 193 are disposed on a lower surface of the base 191. The plurality of teeth 193 of the upper ratchet 125 are adapted to engage the plurality of teeth 158 of the lower ratchet 151. An arm 192 extends upwardly from the base 191. Preferably, a second arm 192 is disposed diametrically opposite the first arm 192, as shown in FIG. 4. The arm 192 keys the upper ratchet 125 to the inner barrel 133. A wall 194 extends upwardly from the base 191 of the upper ratchet 125.

    [0024] A first spring 121 is disposed between the upper ratchet 125 and the loading barrel 135. A first end 122 of the first spring 121 is secured to the wall 194 of the upper ratchet 125, as shown in FIG. 24. A second end 124 of the first spring 121 is received by a surface 182 of the loading barrel 135. Preferably, the first spring 121 is a torsion spring, although any suitable spring may be used.

    [0025] An inner barrel 133 preferably has a substantially cylindrical shape and has an outer surface 144 and an inner surface 146, as shown in FIGS. 19 and 20. Splines extend axially along a portion of the outer surface 146 of the inner barrel 133. A base 147 is disposed within the inner barrel 133, as shown in FIGS. 24 and 25. A plurality of notches 149 are disposed on the inner surface 146 of the inner barrel and are adapted to key the inner barrel to corresponding notches 25 (FIG. 1) of the pen knob 24 of the drug delivery pen 100.

    [0026] A second spring 127 is disposed between the lower ratchet 151 and the inner barrel 133, as shown in FIGS. 24 and 25. A first end 172 of the second spring 127 engages the lower ratchet 151. A second end 174 of the second spring 127 is received by the base 147 of the inner barrel 133. Preferably, the second spring 127 is a compression spring, although any suitable spring may be used. The second spring 127 biases the lower ratchet 151 toward the upper ratchet 125 such that the teeth of the lower ratchet engage the teeth of the upper ratchet.

    [0027] An outer barrel 131 has a preferably substantially cylindrical shape and has an outer surface 136 and an inner surface 138, as shown in FIGS. 19 and 20. Flexible buttons 123 are movably formed in the outer barrel 131. A rib 148 extends axially along an outer surface 136 of the outer barrel 131. Preferably, a second rib is disposed diametrically opposite the first rib 148.

    [0028] A fixing barrel 145 has a base 132, as shown in FIG. 20. A wall 134 extends upwardly from the base 132. A groove 136 extends axially along an inner surface of the wall 134. Preferably, a second groove is disposed diametrically opposite the first groove 136. The groove 136 receives the rib 148 of the outer barrel, thereby keying the outer barrel to the fixing barrel 145. A pair of flexible legs 138 extends downwardly from the base and are adapted to secure the additive force device 111 to the drug delivery pen. Preferably, a window 171 is formed between the flexible legs 138 such that a dose setting window 31 of the drug delivery pen 100 is visible to a user after the additive force device 111 is connected to the drug delivery pen 100, as shown in FIG. 21.

    Assembly and Operation



    [0029] Energy is stored in an energy storage device, such as a torsion spring or a compression spring. The inner barrel 133 is attached to the pen knob 24 of the drug delivery pen 100 to transmit torque generated by the additive force device 111 to the drug delivery pen 100. Preferably, the inner barrel 133 is rigidly keyed to the outer sleeve 13 of the drug delivery pen 100. The outer sleeve 13 of the drug delivery pen 100 is preventing from rotating while torquing the barrel 135 of the force additive device 111 and storing energy (torque) in the torsion spring 121 by the engagement of the splines of the buttons 123 and the inner barrel 133. The torsion spring energy is held by a one-way ratchet system that is held together by the second spring 127. The fixing barrel 145 is attached to the outer sleeve 13 of the drug delivery pen 100 in any suitable manner, such as by a snap connect or friction fit. As shown in FIGS. 24 and 25, inwardly extending tabs 140 of the fixing barrel 145 may secure the fixing barrel to the drug delivery pen 100 by a snap connect.

    [0030] Although not limited thereto, the following description refers to the first spring 121 being a 1.4 in-lbs torsion spring 121 as shown in FIGS. 14 - 16. The first spring 121 may be loaded before or after connecting the additive force device 111 to the drug delivery pen 100 by twisting the loading barrel 135 while pressing the cantilever buttons 123. As the user grasps the loading barrel 135 and the buttons 123 are being flexed inwardly, the splines 142 of the outer barrel 131 engage the corresponding splines 143 of the inner barrel 133 to prevent the inner barrel 133 from rotating as the loading barrel 135 is rotated to load the torsion spring 121. The loading barrel 135 is keyed to the lower ratchet 151 by the groove 184 and rib 153. The compression spring 127 applies a constant biasing force on the lower ratchet 151 to contact the lower ratchet 151 with the upper ratchet 125 such that the teeth of the upper and lower ratchets engage. The upper ratchet 125 is keyed to the inner barrel 133 by the arms 192 engaging openings 138 in the inner barrel. By depressing the buttons 123, the splines of the outer barrel 133 and the inner barrel 131 engage such that the inner barrel is prevented from rotating when the loading barrel 135 is rotated. The plurality of teeth of the upper ratchet 125 slide over the plurality of teeth of the lower ratchet 151, thereby creating an audible indication that the first spring is being energized.

    [0031] After the additive force device 111 is connected to the drug delivery pen 100, the dose is set using the additive force device. The user grasps and rotates the loading barrel 135 to set the desired dose. The window 171 formed in the fixing barrel 145 allows the user to view the dose setting window 31 of the drug delivery pen. The fingers 123 are not flexed inwardly such that the pen knob 24 rotates with rotation of the loading barrel 135, thereby allowing the user to set the dose.

    [0032] The loading barrel 135 is keyed to the lower ratchet 151 such that the lower ratchet rotates with the loading barrel. The plurality of teeth 158 of the lower ratchet 151 engage the plurality of teeth 193 of the upper ratchet 125 because the second spring 127 biases the lower ratchet against the upper ratchet. The upper ratchet 125 is keyed to the inner barrel 133 by the arms 192 engaging the inner barrel, as shown in FIG. 25. The inner barrel 133 is keyed to the pen knob 24 such that rotation of the loading barrel 135 results in rotation of the pen knob 24. Accordingly, the rotation of the pen knob 24 moves the pen knob away from the outer sleeve 13 of the drug delivery pen 100 as with normal operation of the drug delivery pen.

    [0033] Outward movement of the pen knob 24 causes the pen knob to push the base 147 of the inner barrel 133 toward the button 161. The outer barrel 131 is keyed to the fixing barrel 145 by the rib 148 and groove 136, such that the outer barrel 131 moves axially relative to the fixing barrel 145. Accordingly, when the pen knob 24 moves outwardly, the resulting movement of the inner barrel 133 moves the outer barrel 131 along the axial groove 136 of the fixing barrel 145. The inner barrel 133 also pushes the second spring 127, which pushed the lower ratchet 151 and upper ratchet 125 as well as the loading barrel 135 outwardly. An injection may now be made with the drug delivery pen 100.

    [0034] To make an injection, the user pushes the button 161 of the additive force device 111 toward the drug delivery pen 100. The inner surface 165 of the button 161 contacts the loading barrel 135 such that the loading barrel moves with the button 161. Inward movement of the loading barrel 135 pushes the lower ratchet 151, which is keyed to the loading barrel, inwardly. The lower ratchet 151 and the upper ratchet 125 remain engaged such that rotation of the upper ratchet 125 is prevented and the energy stored in the first spring 121 is not released. The lower ratchet 151 pushes the compression spring 127, which in turn pushes on the base 147 of the inner barrel 133. Inward movement of the inner barrel 133 results in inward movement of the pen knob 24, which is keyed to the inner barrel 133, thereby administering medicament in accordance with normal operation of the drug delivery pen 100.

    [0035] When the force required to administer the medicament is greater than a predetermined preload, five pounds for example, the second spring 127 compresses such that the lower ratchet 151 is disengaged from the upper ratchet 125. When the plurality of teeth 158 of the lower ratchet 151 disengage from the plurality of teeth 193 of the upper ratchet 125, the upper ratchet 125 is free to rotate. The energy stored in the first spring 121 is released and causes the upper ratchet 125 to rotate. The rotation of the upper ratchet 125 causes rotation of the inner barrel 133, which is keyed to the upper ratchet 125. The rotation of the inner barrel 133 rotates the pen knob 24 because the pen knob 24 is keyed to the inner barrel. Accordingly, the torque stored in the first spring 121 is transmitted to the pen knob 24, thereby adding to the user input force. The medicament is administered with the drug delivery pen in accordance with normal operation thereof.

    [0036] The second end 124 of the first spring 121 is connected to the loading barrel 135. The inward movement of the loading barrel 135 (resulting from the button 161 being pushed inwardly) causes the splines 137 of the loading barrel 135 to engage the splines 141 of the outer barrel 131. The splines 137 of the loading barrel 135 and the splines 141 of the outer barrel 131 are initially spaced apart by the second spring 127. The splines 137 of the loading barrel 135 and the splines 141 of the outer barrel 131 engage when a user feels a high injection force. The outer barrel 131 is keyed to the fixing barrel 145, which is in turn keyed to the drug delivery pen 100. Accordingly, the loading barrel 135 is prevented from rotating such that the torque is delivered to the upper ratchet 125.

    [0037] The torsion supplied is translated to a linear force by the drug delivery pen's own mechanism and assists the user by supplying force over and above the user's finger applied force, thereby allowing the user to accomplish a more difficult intradermal medication injection.

    [0038] The force additive device 111 according to exemplary embodiments of the present invention adds force to aid the user during injection preferably when the user experiences a high injection force. When the user does not experience a high force, the force additive device 111 is not activated and remains cocked until additional force is required. Some users may not require the additional force, but the force additive device 111 remains cocked should a high injection force be experienced. No action is necessary when the force additive device 111 remains cocked.

    [0039] The force additive device 111 applies force to aid the user at the moment when the user experiences the high injection force and not before such time. Thus, the stored energy of the first spring 121 is applied when it is needed most and preferably only at such time. This configuration optimally utilizes the torque stored in the first spring 121 by applying the maximum amount of the stored energy to the highest pressure peak recorded on an intradermal pressure graph.

    [0040] A color indicator window may be added to visually alert the user when the device is cocked. For example, the color green may be used to indicate that the force additive device is cocked and the color red to indicate that the force additive device needs to be cocked.

    [0041] As shown in FIGS. 12 and 13, input forces and respective output forces are shown for a drug delivery pen with (FIG. 13) and without (FIG. 12) the force additive device. For example, a drug delivery pen without the force additive device outputs 7.14 pounds for a four pound input, as shown in FIG. 12. An output of approximately twenty pounds is required to overcome the intradermal back pressure. Adding a 1.4 in 1b torque to the pen barrel using the torsion spring of FIGS. 14 -16 adds output force to the drug delivery pen. As shown in FIG. 13, a 27.14 lb force is output when four pounds is input to a drug delivery pen 100 including the force additive device 111 such that the user input force of approximately 4 lb is sufficient to overcome intradermal back pressure. The results of FIGS. 12 and 13 are diagrammatically illustrated in FIGS. 10 and 11, respectively.

    [0042] The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the scope of the present invention. The description of exemplary embodiments of the present invention is intended to be illustrative. Various modifications, alternatives and variations will be apparent to those of ordinary skill in the art, and are intended to fall within the scope of the invention as defined in the appended claims and their equivalents.


    Claims

    1. An additive force device in combination with a drug delivery device, the combination comprising:

    a drug delivery device (100) having a dose setting knob (24) at an end thereof; and

    a separate additive force device (111) connectible to said dose setting knob (24) end of said drug delivery device (111) to increase the amount of force exerted by a user on the knob (24) to facilitate injection, said additive force device (111) including,

    a first spring (121);

    a loading barrel (135) connected to said first spring (121) for storing torque therein;

    a ratchet assembly (129) connected to said loading barrel (135) and to said first spring (121), said ratchet assembly (129) having a first position in which torque is stored in said first spring (121) and a second position in which torque is released from said first spring (121); and

    an inner barrel (133) connected to said ratchet assembly (129) and to said drug delivery device (100), said inner barrel (133) transmitting the stored torque from said first spring (121) to the drug delivery device (100) to increase an injection force thereof.


     
    2. The combination of claim 1, wherein
    said ratchet assembly (129) includes a lower ratchet (151) and an upper ratchet (125), each of said lower and upper ratchets (125, 151) having a plurality of teeth (158, 193) for engagement therebetween.
     
    3. The combination of claim 2, wherein
    said lower ratchet (151) is connected to said loading barrel (135) and/or said upper ratchet (125) is connected to said first spring (121).
     
    4. The combination of claim 3, wherein
    said inner barrel (133) is connected to said upper ratchet (125) and to the drug delivery device (100), and
    when said upper and lower ratchets (125, 151) are engaged torque is prevented from being released from said first spring (121), and when said upper and lower ratchets (125, 151) are separated said inner barrel (133) transmits the stored torque from said first spring (121) to the drug delivery device (100) to increase an injection force thereof.
     
    5. The combination of any one of claims 2-4, wherein
    a second spring (127) is disposed between said inner barrel (133) (133) and said lower ratchet (151) to bias said lower ratchet (151) against said upper ratchet (125).
     
    6. The combination of claim 5, wherein
    said lower and upper ratchets (151, 125) are engaged when said ratchet assembly (129) is in said first position, and said lower and upper ratchets (151, 125) are spaced apart when said ratchet assembly (129) is in said second position.
     
    7. The combination of any one of claims 1-6, wherein
    said inner barrel (133) is disposed in an outer barrel (131), said outer barrel (131) having a flexible button (123) for engaging said inner barrel (133) when torque is being supplied to said first spring (121) to substantially prevent movement of said inner barrel (131) and said lower ratchet (151).
     
    8. The combination of claim 5, wherein
    said first spring (121) is a torsion spring or wherein said second spring (127) is a compression spring.
     
    9. The combination of claim 5 or 8, wherein
    said second spring (127) has a preload of approximately five pounds.
     
    10. The combination of claim 7, wherein
    a fixing barrel (145) is connected to said outer barrel (131) and to said drug delivery device (100), said outer barrel (131) being axially movable within said fixing barrel (145).
     
    11. The combination of claim 10, wherein
    said loading barrel (135) being engaged with said outer barrel (131) when said ratchet assembly (129) is in said second position to substantially prevent movement of said loading barrel (135).
     
    12. The combination of claim 2, wherein
    said plurality of teeth (193) of said upper ratchet (125) slide over said plurality of teeth (158) of said lower ratchet (151) creating an audible signal during rotation of the loading barrel (135).
     
    13. The combination of any one of the preceding claims, wherein
    said inner barrel (133) is keyed to said drug delivery device (100).
     
    14. The combination of one of claims 5, 8, or 9, wherein
    axial movement of the loading barrel (135) pushes the lower ratchet (151), the lower ratchet (151) pushes the second spring (127), and the second spring (127) pushes the inner barrel (131) which results in movement of the pen knob (24).
     
    15. The combination of claim 14, wherein
    compression of the second spring (127) causes the lower ratchet (151) to disengage the upper ratchet (125), releasing the energy stored in the first spring (121).
     


    Ansprüche

    1. Zusatzkraft-Aufbringungsvorrichtung in Kombination mit einer Medikamentenzuführvorrichtung, wobei die Kombination aufweist:

    eine Medikamentenzuführvorrichtung (100), die an einem Ende mit einem Dosier-Einstellknopf (24) versehen ist; und

    eine separate Zusatzkraft-Aufbringungsvorrichtung (111), die mit dem den Dosier-Einstellknopf (24) aufweisenden Ende der Medikamentenzuführvorrichtung (111) verbindbar ist, um zwecks Erleichterung der Injektion den Betrag der von einem Benutzer auf den Knopf (24) ausgeübten Kraft zu erhöhen, wobei die Zusatzkraft-Aufbringungsvorrichtung (111) aufweist:

    eine erste Feder (121);

    einen Belastungszylinder (135), der mit der ersten Feder (121) verbunden ist, um eine Drehkraft in dem Belastungszylinder zu speichern;

    eine Ratschenvorrichtung (129), die mit dem Belastungszylinder (135) und mit der ersten Feder (121) verbunden ist, wobei die Ratschenvorrichtung (129) eine erste Position, in der Drehkraft in der ersten Feder (121) gespeichert ist, und eine zweite Position aufweist, in der Drehkraft aus der ersten Feder (121) freigegeben wird; und

    einen inneren Zylinder (133), der mit der Ratschenvorrichtung (129) und mit der Medikamentenzuführvorrichtung (100) verbunden ist, wobei der innere Zylinder (133) die gespeicherte Drehkraft von der ersten Feder (121) zu der Medikamentenzuführvorrichtung (100) überträgt, um eine Injektionskraft der Medikamentenzuführvorrichtung zu erhöhen.


     
    2. Kombination nach Anspruch 1, bei der
    die Ratschenvorrichtung (129) eine untere Ratsche (151) und eine obere Ratsche (125) aufweist, wobei jede der unteren und obere Ratschen (125,151) mehrere Zähne (158,193) zum gegenseitigen Zusammengriff zwischen den Ratschen aufweist.
     
    3. Kombination nach Anspruch 2, bei der
    die untere Ratsche (151) mit dem Belastungszylinder (135) verbunden ist und/oder die obere Ratsche (125) mit der ersten Feder (121) verbunden ist.
     
    4. Kombination nach Anspruch 3, bei der
    der innere Zylinder (133) mit der oberen Ratsche (125) und mit der Medikamentenzuführvorrichtung (100) verbunden ist, und
    bei Zusammengriff der oberen und unteren Ratschen (125,151) eine Freigabe von Drehkraft aus der ersten Feder (121) verhindert wird, und bei Trennung der oberen und unteren Ratschen (125,151) der innere Zylinder (133) die gespeicherte Drehkraft von der ersten Feder (121) zu der Medikamentenzuführvorrichtung (100) überträgt, um eine Injektionskraft der Medikamentenzuführvorrichtung zu erhöhen.
     
    5. Kombination nach einem der Ansprüche 2-4, bei der
    eine zweite Feder (127) zwischen dem inneren Zylinder (133) und der unteren Ratsche (151) angeordnet ist, um die untere Ratsche (151) gegen die obere Ratsche (125) vorzuspannen.
     
    6. Kombination nach Anspruch 5, bei der
    die unteren und oberen Ratschen (151,125) zusammengreifen, wenn sich die Ratschenvorrichtung (129) in der ersten Position befindet, und die unteren und oberen Ratschen (151,125) voneinander abgerückt sind, wenn sich die Ratschenvorrichtung (129) in der zweiten Position befindet.
     
    7. Kombination nach einem der Ansprüche 1-6, bei der
    der innere Zylinder (133) in einem äußeren Zylinder (131) angeordnet ist, wobei der äußere Zylinder (131) einen flexiblen Knopf (123) aufweist, um bei Aufbringung von Drehkraft auf die erste Feder (121) mit dem inneren Zylinder (133) zusammenzugreifen, damit eine Bewegung des inneren Zylinders (133) und der unteren Ratsche (151) im Wesentlichen verhindert wird.
     
    8. Kombination nach Anspruch 5, bei der
    die erste Feder (121) eine Torsionsfeder ist oder bei der die zweite Feder (127) eine Druckfeder ist.
     
    9. Kombination nach Anspruch 5 oder 8, bei der
    die zweite Feder (127) eine Vorbelastung von ungefähr fünf Pound hat.
     
    10. Kombination nach Anspruch 7, bei der
    ein Fixierzylinder (145) mit dem äußeren Zylinder (131) und mit der Medikamentenzuführvorrichtung (100) verbunden ist, wobei der äußere Zylinder (131) in dem Fixierzylinder (145) axial bewegbar ist.
     
    11. Kombination nach Anspruch 10, bei der,
    wenn sich die Ratschenvorrichtung (129) in der zweiten Position befindet, der Belastungszylinder (135) mit dem äußeren Zylinder (131) zusammengreift, um eine Bewegung des Belastungszylinders (135) im Wesentliche zu verhindern.
     
    12. Kombination nach Anspruch 2, bei der
    während einer Drehung des Belastungszylinders (135) die mehreren Zähne (193) der oberen Ratsche (125) über die mehreren Zähne (158) der unteren Ratsche (151) gleiten, wobei sie ein akustisches Signal erzeugen.
     
    13. Kombination nach einem der vorhergehenden Ansprüche, bei der
    der innere Zylinder (133) mit der Medikamentenzuführvorrichtung (100) verkeilt ist.
     
    14. Kombination nach einem der Ansprüche 5, 8 oder 9, bei der
    durch eine Axialbewegung des Belastungszylinders (135) die untere Ratsche (151) vorgedrückt wird, die untere Ratsche (151) die zweite Feder (127) vordrückt und die zweite Feder (127) den inneren Zylinder (133) vordrückt, was in einer Bewegung des Stift-Knopfs (24) resultiert.
     
    15. Kombination nach Anspruch 14, bei der
    ein Zusammendrücken der zweiten Feder (127) die untere Ratsche (151) veranlasst, die obere Ratsche (125) ausrücken zu lassen, wobei die in der ersten Feder (121) gespeicherte Energie freigegeben wird.
     


    Revendications

    1. Dispositif de force additionnelle en combinaison avec un dispositif d'administration de médicament, la combinaison comprenant :

    un dispositif d'administration de médicament (100) ayant un bouton de réglage de dose (24) au niveau d'une extrémité de celui-ci ; et

    un dispositif de force additionnelle distinct (111) pouvant être relié à ladite extrémité du bouton de réglage de dose (24) dudit dispositif d'administration de médicament (111) pour augmenter la quantité de force exercée par un utilisateur sur le bouton (24) pour faciliter l'injection, ledit dispositif de force additionnelle (111) comportant,

    un premier ressort (121) ;

    un cylindre de chargement (135) relié audit premier ressort (121) pour stocker un couple dedans ;

    un ensemble de cliquet (129) relié audit cylindre de chargement (135) et audit premier ressort (121), ledit ensemble de cliquet (129) ayant une première position dans laquelle le couple est stocké dans ledit premier ressort (121) et une deuxième position dans laquelle le couple est libéré dudit premier ressort (121) ; et

    un cylindre intérieur (133) relié audit ensemble de cliquet (129) et audit dispositif d'administration de médicament (100), ledit cylindre intérieur (133) transmettant le couple stocké à partir dudit premier ressort (121) au dispositif d'administration de médicament (100) pour augmenter une force d'injection de celui-ci.


     
    2. Combinaison de la revendication 1, dans laquelle
    ledit ensemble de cliquet (129) comporte un cliquet inférieur (151) et un cliquet supérieur (125), chacun desdits cliquets supérieur et inférieur (125, 151) ayant une pluralité de dents (158, 193) pour s'engager entre eux.
     
    3. Combinaison de la revendication 2, dans laquelle
    ledit cliquet inférieur (151) est relié audit cylindre de chargement (135) et/ou ledit cliquet supérieur (125) est relié audit premier ressort (121).
     
    4. Combinaison de la revendication 3, dans laquelle
    ledit cylindre intérieur (133) est relié audit cliquet supérieur (125) et au dispositif d'administration de médicament (100), et
    lorsque lesdits cliquets supérieur et inférieur (125, 151) sont engagés, le couple est empêché d'être libéré dudit premier ressort (121), et, lorsque lesdits cliquets supérieur et inférieur (125, 151) sont séparés, ledit cylindre intérieur (133) transmet le couple stocké à partir dudit premier ressort (121) au dispositif d'administration de médicament (100) pour augmenter une force d'injection de celui-ci.
     
    5. Combinaison de l'une quelconque des revendications 2 à 4, dans laquelle
    un deuxième ressort (127) est disposé entre ledit cylindre intérieur (133) et ledit cliquet inférieur (151) pour solliciter ledit cliquet inférieur (151) contre ledit cliquet supérieur (125).
     
    6. Combinaison de la revendication 5, dans laquelle
    lesdits cliquets inférieur et supérieur (151, 125) sont engagés lorsque ledit ensemble de cliquet (129) est dans ladite première position, et lesdits cliquets inférieur et supérieur (151, 125) sont espacés lorsque ledit ensemble de cliquet (129) est dans ladite deuxième position.
     
    7. Combinaison de l'une quelconque des revendications 1 à 6, dans laquelle
    ledit cylindre intérieur (133) est disposé dans un cylindre extérieur (131), ledit cylindre extérieur (131) ayant un bouton flexible (123) pour s'engager avec ledit cylindre intérieur (133) lorsqu'un couple est en train d'être fourni audit premier ressort (121) pour empêcher essentiellement le mouvement dudit cylindre intérieur (133) et dudit cliquet inférieur (151).
     
    8. Combinaison de la revendication 5, dans laquelle
    ledit premier ressort (121) est un ressort de torsion ou dans laquelle ledit deuxième ressort (127) est un ressort de compression.
     
    9. Combinaison de la revendication 5 ou 8, dans laquelle
    ledit deuxième ressort (127) a une précharge d'environ cinq livres.
     
    10. Combinaison de la revendication 7, dans laquelle
    un cylindre de fixation (145) est relié audit cylindre extérieur (131) et audit dispositif d'administration de médicament (100), ledit cylindre extérieur (131) pouvant se déplacer axialement à l'intérieur dudit cylindre de fixation (145).
     
    11. Combinaison de la revendication 10, dans laquelle
    ledit cylindre de chargement (135) étant engagé avec ledit cylindre extérieur (131) lorsque ledit ensemble de cliquet (129) est dans ladite deuxième position pour empêcher essentiellement le mouvement dudit cylindre de chargement (135).
     
    12. Combinaison de la revendication 2, dans laquelle
    ladite pluralité de dents (193) dudit cliquet supérieur (125) glissent sur ladite pluralité de dents (158) dudit cliquet inférieur (151) créant un signal audible au cours de la rotation du cylindre de chargement (135).
     
    13. Combinaison de l'une quelconque des revendications précédentes, dans laquelle
    ledit cylindre intérieur (133) est claveté sur ledit dispositif d'administration de médicament (100).
     
    14. Combinaison de l'une des revendications 5, 8, ou 9, dans laquelle
    le mouvement axial du cylindre de chargement (135) pousse le cliquet inférieur (151), le cliquet inférieur (151) pousse le deuxième ressort (127), et le deuxième ressort (127) pousse le cylindre intérieur (133) qui entraîne le mouvement du bouton de stylo (24).
     
    15. Combinaison de la revendication 14, dans laquelle
    la compression du deuxième ressort (127) amène le cliquet inférieur (151) à se désengager du cliquet supérieur (125), libérant l'énergie stockée dans le premier ressort (121).
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description