CROSS REFERENCE TO RELATED APPLICATIONS

The present application is the national stage entry of International Patent Application No. PCT/EP2017/081309, filed on Dec. 4, 2017, and claims priority to Application No. EP 16202659.5, filed on Dec. 7, 2016, the disclosures of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an injection device and to a method of removing a cap from a housing of an injection device.

BACKGROUND

Injection devices, such as auto-injectors, are known in the art for dispensing a medicament to the injection site of a patient. Such injection devices typically comprise a body and a cap. A needle syringe is located in the body. The cap is removably attached to the body to shield the needle of the needle syringe. To dispense the medicament, the cap is first removed from the body to expose the needle. The needle is then inserted into the body of the patient at the injection site to dispense the medicament.

It is important that the cap is held onto the body with sufficient force to ensure that the cap is not accidentally removed from the body during transport and storage of the injection device. This ensures that the needle is kept sterile and also prevents the sharp needle from causing injury. However, the force required to hold the cap and body together can make it difficult for the patient to intentionally remove the cap from the body prior to injection, particularly if the patient is elderly or infirm.

SUMMARY

In certain aspects, an improved injection device is provided.

According to some aspects, there is provided an injection device comprising: a housing for holding a syringe that has a needle at one end; a cap that is removably attached to the housing and has a needle shield to cover said needle; a gear assembly comprising first and second linear gears and a double gear, wherein the gear assembly is configured such that movement of the first linear gear in a first direction rotates the double gear to drive the second linear gear to urge the needle shield away from the housing; and, an actuator configured to move the first linear gear in the first direction.

The gear assembly and actuator may be configured to reduce the force that must be exerted by the patient to urge the needle shield away from the body. Therefore, separation of the needle shield from the body can be made easier. In addition, the gear assembly and actuator may allow for a controlled separation of the needle shield from the body. Furthermore, the double gear allows for a compact needle shield removal mechanism that is relatively easy to manufacture and assemble.

In one embodiment, the double gear comprises first and second portions that are fixed relative to each other and share a common rotational axis. In one embodiment, the first portion is configured to engage the first linear gear and the second portion is configured to engage the second linear gear. In one such embodiment, the actuator is configured to be slid by a user to move the first linear gear in the first direction.

The diameters of the first and second portions of the double gear may be the same. In an alternative embodiment, the diameters of the first and second portions are different.

In one embodiment, the gear assembly is configured to have a gear ratio such that a force exerted on the actuator is translated into a larger force being exerted on the needle shield. This reduces the force that must be exerted by the patient to urge the needle shield away from the housing.

In one embodiment, the double gear is rotatably coupled to the housing. In another embodiment, the double gear is rotatably coupled to the cap.

In one embodiment, the actuator is slidable in a longitudinal direction of the housing to urge the needle shield away from the housing. This sliding movement may be easier for the patient to perform and may allow for a more controlled removal of the needle shield from the housing.

In one embodiment, the actuator is located at a distal end of the cap and wherein the actuator is slidable towards a proximal end of the injection device to urge the needle shield away from the housing. Therefore, the patient may press the actuator against a flat surface, such as a table surface, to urge the needle shield away from the housing, This pressing motion simplifies operation of the actuator, particularly if the patient is elderly or infirm.

In another embodiment, the actuator is located at a distal end of the cap and wherein the actuator is slidable away from a proximal end of the injection device to urge the needle shield away from the housing. Therefore, the patient may pull the actuator to urge the needle shield away from the housing. This pulling motion simplifies operation of the actuator, particularly if the patient is elderly or infirm.

In one embodiment, the actuator comprises a space for receiving a finger of a patient.

In one embodiment, the first linear gear and/or second linear gear is configured to engage with the double gear. The first linear gear may be fixed relative to the actuator.

The second linear gear may be fixed relative to the needle shield.

In one embodiment, the first linear gear and/or second linear gear comprises a rack gear.

In one embodiment, one of the second linear gear and the rotary gear is on the housing and the other is on the cap. In an alternative embodiment, said one of the second linear gear and the rotary gear is on a part of the injection device other than the housing, for example, a needle sleeve of the injection device or a part of the syringe. In one embodiment, the injection device comprises a plurality of gear assemblies. This may allow for a more even and balanced exertion of force on the needle shield to urge the needle shield away from the body. For example, if the injection device comprises two gear assemblies then the gear assemblies may be located on opposite sides of the central axis of the injection device to apply a force to the needle shield from both sides of the central axis.

In one embodiment, the needle shield is configured to frictionally engage with said syringe when the cap is attached to the housing.

In one embodiment, the injection device further comprises a syringe having a needle at one end and being received in the housing, wherein the syringe contains a medicament.

In one embodiment, the injection device is an auto-injector.

According to some aspects, there is also provided a method of removing a cap from a housing of an injection device, wherein the housing holds a syringe that has a needle at one end and wherein the cap is removably attached to the housing and has a needle shield to cover the needle, the method comprising: moving an actuator relative to the cap or housing to move a first linear gear in a first direction to rotate a double gear, wherein the injection device comprises a second linear gear that is coupled to the double gear such that said rotation of the double gear drives the second linear gear to urge the needle shield away from the housing.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

