DRIVING MECHANISM FOR DRIVING A PLUNGER OF AN AUTO-INJECTOR TO SLIDE RELATIVE TO A RESERVOIR OF THE AUTO-INJECTOR AND AUTO-INJECTOR THEREWITH

A driving mechanism for driving a plunger of an auto-injector to slide relative to a reservoir of the auto-injector is provided. The driving mechanism includes a first transmission component, a driving component, a second transmission component, a third transmission component, a sliding component and a bracket. The driving component is for driving the first transmission component to rotate to drive the second transmission component to rotatably drive the third transmission component rotate together with the second transmission component, so as to drive the sliding component to slide relative to the third transmission component by the third transmission component to push the plunger to pump a drug out of the reservoir. The sliding component passes through a guiding portion of the bracket, and the guiding portion is configured to guide the sliding component to slide without any rotation. Besides, a related auto-injector is provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a driving mechanism and an auto-injector therewith, and more specifically, to a driving mechanism for driving a plunger of an auto-injector to slide relative to a reservoir of the auto-injector and an auto-injector therewith.

2. Description of the Prior Art

An auto-injector, e.g., an on-body injector, is a medical device designed to deliver a dose of a drug. However, the conventional auto-injectors available in the markets are unable to meet requirements of small volume, high driving power, long driving distance, long injecting period and accurate drug dose delivery rate. Therefore, an improvement of the auto-injector is urgently needed.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide a driving mechanism for driving a plunger of an auto-injector to slide relative to a reservoir of the auto-injector and an auto-injector therewith for solving the aforementioned problem.

In order to achieve the aforementioned objective, the present invention discloses a driving mechanism for driving a plunger of an auto-injector to slide relative to a reservoir of the auto-injector. The driving mechanism includes a first transmission component, a driving component, a second transmission component, a third transmission component, a sliding component and a bracket. The driving component is coupled to the first transmission component and for driving the first transmission component to rotate. The second transmission component is rotatably engaged with the first transmission component. The second transmission component is driven by the first transmission component to rotate when the driving component drives the first transmission component to rotate. The third transmission component is fixedly connected to the second transmission component. The third transmission component is driven by the second transmission component to rotate when the first transmission component drives the second transmission component to rotate. The sliding component is at least partially slidably disposed inside the third transmission component and coupled to the third transmission component. The sliding component is connected to the plunger. The sliding component is driven by the third transmission component to slide relative to the third transmission component when the third transmission component rotates. The bracket includes a guiding portion. The sliding component passes through the guiding portion. The third transmission component is rotatable relative to the bracket, and the guiding portion is configured to guide the sliding component to slide without a rotation.

According to an embodiment of the present invention, when the driving component drives the first transmission component to rotate around a first rotating axis, the first transmission component drives the second transmission component to rotate around a second rotating axis so as to drive the third transmission component to rotate around the second rotating axis together with the second transmission component, so that the sliding component is driven to slide relative to the third transmission component along a sliding direction parallel to the second rotating axis without the rotation around the second rotating axis.

According to an embodiment of the present invention, the first transmission component is a worm screw. The second transmission component is a worm gear. The third transmission component is a screw sleeve. The sliding component is a screw rod, and the driving component is an electric motor.

According to an embodiment of the present invention, the driving mechanism further includes a reducer coupled between the driving component and the first transmission component.

According to an embodiment of the present invention, the reducer is a gearbox.

According to an embodiment of the present invention, the guiding portion includes a sliding through hole structure. The sliding component slidably passes through the sliding through hole structure. A cross section of the sliding component matches with a cross section of the sliding through hole structure. The sliding component includes at least one first arc part and at least one first flat part connected to the at least one first arc part. The sliding through hole structure includes at least one second arc part and at least one second flat part connected to the at least one second arc part, and the at least one second arc part and the at least one second flat part are respectively corresponding to the at least one first arc part and the at least one first flat part.

According to an embodiment of the present invention, an internal thread structure is formed on an inner periphery of the third transmission component, and an outer thread structure is formed on the at least one first arc part of the sliding component.

According to an embodiment of the present invention, the bracket further includes a holding portion. The holding portion includes a rotation through hole structure, and the third transmission component rotatably passes through the rotation through hole structure.

According to an embodiment of the present invention, the bracket further includes a supporting portion. The supporting portion includes a platform structure, and the platform structure is configured to support a side of the third transmission component.

According to an embodiment of the present invention, the bracket further includes an accommodating portion. The accommodating portion includes an L-shaped structure, and the L-shaped structure is configured to accommodate the first transmission component.

In order to achieve the aforementioned objective, the present invention further discloses an auto-injector. The auto-injector includes a reservoir, a plunger and a driving mechanism. The plunger is slidably disposed inside the reservoir. The driving mechanism is for driving the plunger to slide relative to the reservoir. The driving mechanism includes a first transmission component, a driving component, a second transmission component, a third transmission component, a sliding component and a bracket. The driving component is coupled to the first transmission component and for driving the first transmission component to rotate. The second transmission component is rotatably engaged with the first transmission component. The second transmission component is driven by the first transmission component to rotate when the driving component drives the first transmission component to rotate. The third transmission component is fixedly connected to the second transmission component. The third transmission component is driven by the second transmission component to rotate when the first transmission component drives the second transmission component to rotate. The sliding component is at least partially slidably disposed inside the third transmission component and coupled to the third transmission component. The sliding component is connected to the plunger. The sliding component is driven by the third transmission component to slide relative to the third transmission component when the third transmission component rotates. The bracket includes a guiding portion. The sliding component passes through the guiding portion. The third transmission component is rotatable relative to the bracket, and the guiding portion is configured to guide the sliding component to slide without a rotation.

According to an embodiment of the present invention, when the driving component drives the first transmission component to rotate around a first rotating axis, the first transmission component drives the second transmission component to rotate around a second rotating axis so as to drive the third transmission component to rotate around the second rotating axis together with the second transmission component, so that the sliding component is driven to slide relative to the third transmission component along a sliding direction parallel to the second rotating axis without the rotation around the second rotating axis.

According to an embodiment of the present invention, the first transmission component is a worm screw. The second transmission component is a worm gear. The third transmission component is a screw sleeve. The sliding component is a screw rod, and the driving component is an electric motor.

According to an embodiment of the present invention, the driving mechanism further includes a reducer coupled between the driving component and the first transmission component.

According to an embodiment of the present invention, the reducer is a gearbox.

According to an embodiment of the present invention, the guiding portion includes a sliding through hole structure. The sliding component slidably passes through the sliding through hole structure. A cross section of the sliding component matches with a cross section of the sliding through hole structure. The sliding component includes at least one first arc part and at least one first flat part connected to the at least one first arc part. The sliding through hole structure includes at least one second arc part and at least one second flat part connected to the at least one second arc part, and the at least one second arc part and the at least one second flat part are respectively corresponding to the at least one first arc part and the at least one first flat part.

According to an embodiment of the present invention, an internal thread structure is formed on an inner periphery of the third transmission component, and an outer thread structure is formed on the at least one first arc part of the sliding component.

According to an embodiment of the present invention, the bracket further includes a holding portion. The holding portion includes a rotation through hole structure, and the third transmission component rotatably passes through the rotation through hole structure.

According to an embodiment of the present invention, the bracket further includes a supporting portion. The supporting portion includes a platform structure, and the platform structure is configured to support a side of the third transmission component.

According to an embodiment of the present invention, the bracket further includes an accommodating portion. The accommodating portion includes an L-shaped structure, and the L-shaped structure is configured to accommodate the first transmission component.

In summary, in the present invention, the driving mechanism not only has compact structure and high power and high efficiency transmission but also achieves a long sliding distance and a slow sliding speed of the sliding component and prevents any rotation of the sliding component during a sliding movement of the sliding component. Therefore, the present invention can meet requirements of small volume, high driving power, long driving distance, long injecting period and accurate drug dose delivery rate.

DETAILED DESCRIPTION

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top”, “bottom”, “left”, “right”, “front”, “back”, etc., is used with reference to the orientation of the Figure(s) being described. The components of the present invention can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. Also, if not specified, the term “connect” or “couple” is intended to mean either an indirect or direct electrical/mechanical connection. Thus, if a first device is connected or coupled to a second device, that connection may be through a direct electrical/mechanical connection, or through an indirect electrical/mechanical connection via other devices and connections.

Please refer toFIG.1toFIG.4.FIG.1andFIG.2are partial diagrams of an auto-injector1at different views according to an embodiment of the present invention.FIG.3andFIG.4are partial exploded diagrams of the auto-injector1at different views according to the embodiment of the present invention. As shown inFIG.1toFIG.4, the auto-injector1includes a reservoir11, a plunger12and a driving mechanism13. The plunger12is slidably disposed inside the reservoir11. The driving mechanism13is for driving the plunger12to slide relative to the reservoir11.

In this embodiment, the auto-injector1further includes a case14. The case14includes a first mounting part141and a second mounting part, which is not shown in the figures, detachable installed on the first mounting part141. The reservoir11and the driving mechanism13are mounted on the first mounting part141. The case14is configured to conceal the reservoir11and the driving mechanism.13for preventing damage of the reservoir11and the driving mechanism13.

However, the present invention is not limited to this embodiment. For example, in another embodiment, the case can be a one-piece structure with an opening to expose the reservoir and the driving mechanism.

Please refer toFIG.1toFIG.7.FIG.5andFIG.6are partial diagrams of the driving mechanism13according to the embodiment of the present invention.FIG.7is a partial sectional diagram of the driving mechanism13according to the embodiment of the present invention. As shown inFIG.1toFIG.7, the driving mechanism13includes a first transmission component131, a driving component132, a second transmission component133, a third transmission component134, a sliding component135and a bracket136. The driving component132is coupled to the first transmission component131and for driving the first transmission component131to rotate. The second transmission component133is rotatably engaged with the first transmission component131. The second transmission component133is driven by the first transmission component131to rotate when the driving component132drives the first transmission component131to rotate. The third transmission component134is fixedly connected to the second transmission component133, e.g., by a tightly fitting manner or an integrally forming manner. The third transmission component134is driven by the second transmission component133to rotate when the first transmission component131drives the second transmission component133to rotate. The sliding component135is at least partially slidably disposed inside the third transmission component134and coupled to the third transmission component134. The sliding component135is connected to the plunger12. The sliding component135is driven by the third transmission component134to slide relative to the third transmission component134when the third transmission component134rotates. The bracket136includes a guiding portion1361. The sliding component135passes through the guiding portion1361. The third transmission component134is rotatable relative to the bracket136, and the guiding portion1361is configured to guide the sliding component135to slide without any rotation.

When the driving component132drives the first transmission component131to rotate around a first rotating axis R1, the first transmission component131drives the second transmission component133to rotate around a second rotating axis R2perpendicular to the first rotating axis R1so as to drive the third transmission component134to rotate around the second rotating axis R2together with the second transmission component133, so that the sliding component135is driven to slide relative to the third transmission component134along a sliding direction S parallel to the second rotating axis R2without any rotation around the second rotating axis R2.

Specifically, the first transmission component131can be a worm screw. The second transmission component133can be a worm gear. The third transmission component134can be a screw sleeve. The sliding component135can be a screw rod. The driving component132can be an electric motor. However, the present invention is not limited to this embodiment. It depends on practical demands. For example, in another embodiment, the driving component can be a pneumatic motor, and the first transmission component can be a smaller gear wheel. The second transmission component can be a larger gear wheel.

Besides, in this embodiment, as shown inFIG.1toFIG.7, the driving mechanism13further includes a reducer137coupled between the driving component132and the first transmission component131. An input shaft and an output shaft of the reducer137can be respectively connected to the driving component132and the first transmission component131. The reducer137can have various reduction ratios to control a rotating speed of the first transmission component131, so as to control a sliding speed of the sliding component135.

Specifically, the reducer137can be a gearbox. However, the present invention is not limited to this embodiment. It depends on practical demands. For example, in another embodiment, the reducer can be a pulley and belt system. Alternatively, in another embodiment, the reducer can be omitted.

It should be noticed that the aforementioned configuration can not only have small occupied space and achieve high power and high efficiency transmission but also allow a rotating speed of the third transmission component134to be adjusted by adjusting a first reduction ratio between the first transmission component131and the second transmission component133and/or a second reduction ratio between the driving component132and the first transmission component, e.g., a gear ratio of the reducer137.

Furthermore, in this embodiment, as shown inFIG.1toFIG.4, the driving mechanism13further includes a control unit138and a power source139. The control unit138can be a circuit board for controlling the driving component132to actuate or stop a rotating movement of the first transmission component131and to control the rotating speed or a rotating direction of the first transmission component131. The power source139can be a battery for providing electricity to the control unit138and the driving component132.

In order to achieve configuration of the guiding portion1361to guide the sliding component135to slide without any rotation when the third transmission component134rotatably drives the sliding component135to slide, as shown inFIG.3toFIG.7, the guiding portion1361includes a sliding through hole structure13611. The sliding component135slidably passes through the sliding through hole structure13611. A cross section of the sliding component135matches with a cross section of the sliding through hole structure13611. The sliding component135includes two first arc parts1351opposite to each other, and two first flat parts1352opposite to each other and connected to the two first arc parts1351. The sliding through hole structure13611includes two second arc parts136111opposite to each other, and two second flat parts136112opposite to each other and connected to the two second arc parts136111. The two second arc parts136111and the two second flat parts136112are respectively corresponding to the two first arc parts1351and the two first flat parts1352. An internal thread structure1341is formed on an inner periphery of the third transmission component134, e.g., by plastic injection molding or insert molding, and an outer thread structure13511is formed on each of the first arc parts1351of the sliding component135. The aforementioned configuration can ensure no rotation of the sliding component135during a sliding movement of the sliding component135by a cooperation of the sliding component135and the sliding through hole structure13611, so as to meet a requirement of accurate drug dose delivery rate.

However, the structures of the sliding component and the guiding portion are not limited to this embodiment. For example, in another embodiment, the sliding component can include only one first arc part and one first flat part connected to the first arc part, and the sliding through hole structure can include only one second arc parts and one second flat part connected to the second arc part.

In addition, in order to achieve a stable rotating movement of the third transmission component134and make structure of the driving mechanism reasonably compact, as shown inFIG.3toFIG.7, the bracket136further includes a holding portion1362, a supporting portion1363and an accommodating portion1364. The holding portion1362is opposite to the guiding portion1361and includes a rotation through hole structure13621. The third transmission component134rotatably passes through the rotation through hole structure1362and is located between the holding portion1362and the guiding portion1361. The supporting portion1363is connected to the guiding portion1361and includes a platform structure13631. The platform structure13631can support a lower side of the third transmission component134to prevent the third transmission component134from accidently falling down. The accommodating portion1364is connected to the supporting portion1363and the holding portion1362and includes an L-shaped structure13641for accommodating the first transmission component131.

However, the present invention is not limited to this embodiment. It depends on practical demands. For example, in another embodiment, the accommodating portion can include a bending structure, a step-shaped structure, or a U-shaped structure. Alternatively, in another embodiment, at least one of the holding portion, the supporting portion and the accommodating portion can be omitted.

Detailed description for operational principle of the auto-injector1is provided as follows. Please further refer toFIG.5toFIG.9.FIG.8andFIG.9are diagrams of the auto-injector1in different states according to the embodiment of the present invention. As shown inFIG.5toFIG.9, after the auto-injector1is attached on a patient's body, the driving component132can be controlled by the control unit138to drive the first transmission component131to rotate around the first rotating axis R1with the reducer137. When the first transmission component131is driven to rotate around the first rotating axis R1, the first transmission component131drives the second transmission component133to rotate around the second rotating axis R2so as to drive the third transmission component134to rotate around the second rotating axis R2together with the second transmission component133, so that the sliding component135can be driven to slide relative to the third transmission component134along the sliding direction S without any rotation, so as to drive the plunger12to slide relative to the reservoir11from a position as shown inFIG.8to a position as shown inFIG.9to stably pump a drug out of the reservoir11to complete a drug injection.

In contrast to the prior art, in the present invention, the driving mechanism not only has compact structure and high power and high efficiency transmission but also achieves a long sliding distance and a slow sliding speed of the sliding component and prevents any rotation of the sliding component during a sliding movement of the sliding component. Therefore, the present invention can meet requirements of small volume, high driving power, long driving distance, long injecting period and accurate drug dose delivery rate.