EP-4739373-A1 - DRIVE SPRING AND NEEDLE COVER SPRING FOR AN INJECTION DEVICE

EP4739373A1EP 4739373 A1EP4739373 A1EP 4739373A1EP-4739373-A1

Abstract

The present invention relates to an injection device (1) for dispensing a drug from a reservoir (3) through a needle (5). The injection device (1) comprises a housing (50) defining a longitudinal axis, a drive member (30) movable relative to the housing (50) to dispense the drug, a spring member (6) operatively coupled the drive member (30) to move the drive member in a dispensing direction and a needle cover (10) movable along the longitudinal axis relative to the housing (50) between a needle covering position and a retracted position defining a needle cover movement along a first distance. Additionally, the spring member (6) is operatively coupled to the needle cover (10) such that the needle cover movement causes the spring member (6) to compresses or expand.

Inventors

SCHRUL, CHRISTIAN
LOSER, PETER
TSCHIRREN, MARKUS
GLAUSER, OLIVER

Assignees

Ypsomed AG

Dates

Publication Date: 20260513
Application Date: 20240523

Claims (1)

PATENT CLAIMS 1. An injection device ( 1) for dispensing a drug from a reservoir (3) through a needle (5), the injection device (1) comprising a housing (50) defining a longitudinal axis; a drive member (30) movable relative to the housing (50) to dispense the drug; a spring member (6) operatively coupled the drive member (30) to move the drive member in a dispensing direction and a needle cover (10) movable along the longitudinal axis relative to the housing (50) between a needle covering position and a retracted position defining a needle cover movement along a first distance, characterized in that the spring member (6) is additionally and operatively coupled to the needle cover (10) such that the needle cover movement causes the spring member (6) to compresses or expand. 2. Injection device (1) according to claim 1, wherein the drive member (30) is a plunger rod which is biased by the spring member (6) before an injection. 3. Injection device (1) according to claim 1 or 2, wherein a movement of the needle cover (10) towards the retracted position causes the spring member (6) to compress while maintaining the plunger rod bias. 4. Injection device (1) according to claim 2 or 3, wherein the plunger rod (30) is hollow and the spring member (6) is a compression spring at least partially arranged inside the hollow plunger rod (30). 5. Injection device (1) according to any of claims 1 to 4, wherein the operative coupling of the spring member (6) to the needle cover (10) is provided by a rotation member (20) rotatable relative to the housing (50), wherein the rotation member (20) is adapted to transfer, by a rotational movement of the rotation member (20), the needle cover movement into an axial spring member compression movement. 6. Injection device (1) according to claim 5, wherein the spring compression movement defines a second distance wherein the rotation member (20) provides a transmission ratio such that the second distance is shorter than the first distance. 7. Injection device (1) according to any of claims 5 to 7, wherein the rotation member (20) includes a cam control (21, 25) adapted transfer a needle cover movement in proximal direction into the spring member compression movement in a distal direction. 8. Injection device (1) according to any of claims 5 to 7, further comprising a spring connector (40) adapted to move along the longitudinal axis and coupled to the rotation member (20) and further coupled to the spring member (6). 9. Injection device (1) according to claim 8, wherein the needle cover (10) is coupled to the rotation member (20) by a first cam (12) guided in a first cam groove (21) of the rotation member and the spring connector (40) is coupled to the rotation member (20) by a second cam (41) guided in a second cam groove (25) of the rotation member, wherein the rotation member (20) is rotatable around the longitudinal axis. 10. Injection device (1) according to claim 9, wherein the first cam groove (21) is angled to the longitudinal axis in a first angle and the second cam groove (25) is angled to the longitudinal axis in a second angle which is different than the first angle. 11. Injection device (100) according to any of claims 1 to 6, wherein the rotational member is a cantilever (120) rotatable around an axis perpendicular to the longitudinal axis of the housing (150), wherein a first end portion of the cantilever (120) is coupled to the needle cover (110) and a second end portion of the cantilever (120) is operatively coupled to the spring member (106). 12. Injection device (200) according to any of claims 1 to 6, wherein the rotational member is a toothed wheel (220) rotatable around an axis perpendicular to the longitudinal axis of the housing, wherein the needle cover (210) and the spring connector (240) each comprise a toothed rack (213, 214) engaging the toothed wheel (220). 13. Injection device (200) according to claim 12, wherein the toothed wheel (220) includes a first gearwheel (221) with a fist diameter and a second gearwheel (222) with a second diameter different than the first diameter. 14. Injection device (300) according to any of claim 1 to 4, wherein the spring member (320) comprises a first portion (321) coupled to the drive member (330) and a second portion (322) coupled to the needle cover (310) wherein the first portion (321) has a first outer diameter and the second portion (322) has a second outer diameter different from the first outer diameter, wherein the spring member (320) is made of a continuous spring winding connecting the first and second portion (321, 322). 15. Injection device (1) according to any of claims 1 to 14, wherein the injection device is an autoinjector with a housing (50) and the reservoir (3) is a prefilled syringe fixedly hold inside the housing (50).

Description

Drive spring and needle cover spring for an injection device FIELD OF THE INVENTION The present invention relates to drug delivery devices or medicament delivery devices for injecting, delivering, administering, infusing or dispensing substances and/or liquids such as insulin, hormone preparations or vaccines. It departs from an injection device comprising a housing, a drive member movable relative to the housing, a spring member operatively coupled to the drive member to move the drive member in a dispensing direction and a needle cover movable along a longitudinal axis relative to the housing. BACKGROUND OF THE INVENTION A variety of diseases exist that require regular treatment by subcutaneous administration of a medicament, and a number of drug delivery devices have been developed to support a patient in accurately and controllably delivering an amount of drug in a self-administration process. Delivery devices include injection devices that are removed from the injection site after each medication event or drug delivery process, as well as infusion devices with a cannula or needle that remains in the skin of the patient for a prolonged period of time. By way of example, diabetes may be treated by self-administration of insulin or its derivatives with the help of multi-variable-dose insulin injection pens. An injection pen device generally has an elongate device body defining a longitudinal main device axis. An automatic injection device has a motor or a drive spring for biasing a plunger rod and shifting a piston in a container barrel, wherein the drive spring may have to be charged or strained manually prior to injection of a dose. A manually powered delivery drive requires a user to manually provide the energy to move the piston, for instance by applying a distal force component to the injection device. The medicament dose to be injected may be manually selected by turning a dosage knob and observing the actual dialed dose from a dose window or display of the insulin pen. A dose is dispensed by inserting the needle into a suited portion of human skin and by moving the piston manually or by pressing a release button of an automatic injection device. Automatic injection devices may comprise an electronic dose dial mechanism to automatically set a dose. Also known is the use of autoinjectors with prefilled syringes. Autoinjectors usually comprise a body for housing the syringe as well as an automatic drive mechanism in order to move the plunger of the syringe upon actuation of the autoinjector. The drive mechanism of the autoinjector typically comprises a source of drive, such as a strong spring for moving a drive member, for example a rod, which acts on the plunger of the syringe. The prefdled syringe has a needle or cannula that is permanently attached to a first end of a syringe barrel or reservoir that is sealed at the opposing end by the plunger. For safety and hygiene reasons it is desirable that the needle does not protrude from a housing of the autoinjector with the exception of the time when the needle is used for injection of a medicament. Thus, either the autoinjector moves the needle out of the housing for the injection and back into the housing after injection or the autoinjector provides a needle cover or needle guard which may be moved to unsheathe the needle for an injection and which may be moved back in a needle covering position after the injection. The majority of autoinjectors are configured as single use devices which incorporate both the syringe and the drive mechanism in the same housing. Such devices are usually disposable for hygiene reasons. In order to reduce costs and complexity it is desirable to design injection devices with a small number of parts and components. WO11101379 Al discloses an auto-injector with a single compression spring for advancing a syringe with a needle, injecting a dose of medicament and retracting the syringe and needle. Under load of the compression spring a syringe holder, a syringe carrier and the syringe are pushed forward while no load is exerted onto the piston inside the syringe. The injection needle is then inserted into an injection site. Subsequently, the compression spring moves the stopper in dispensing direction. When the stopper has nearly bottomed out in the syringe a decoupling member has reached an end position and it pushes against latches to decouple a retraction sleeve from the housing, so the retraction sleeve may slide away from the needle. The syringe holder is taken along in counter-dispensing direction by the retraction sleeve. Thus, the syringe and needle are retracted into a safe position inside the housing, e.g. into the initial position. The plunger is pulled back too. W009007305 Al discloses an injection pen with an ampoule, an ampule holder and a piston rod operatively coupled to a drive spring. During the injection the drive spring drives the plunger rod in dispensing direction. When the piston rod is in an end positi