Dispensing gun for delivering material from a cartridge

Abstract

A dispensing gun (1) intended to deliver material from a cartridge, comprising a frame (2) having a handle (21) and an injection gate (22) for connecting a cartridge, preferably a dental cartridge, a lever (3) having at least two teeth (31) and a piston (4) having at least two notches (41), said injection gate (22) being located in a distal part of the frame (2), - the dispensing gun (1) is provided with means for locking the cartridge directly onto the injection gate (22); - the dispensing gun (1) comprises means for pushing a piston (4) within the cartridge so that the material contained in the cartridge is expelled in a single piston stroke; - the dispensing gun (1) is configured such that the lever (3) assumes a starting state in which a first notch (41) of the piston (4) and a first tooth (31) of the lever (3) engage with each other such that the lever (3) and the handle (21) form an angle of approximately 90° before connecting a cartridge; A dispensing gun (1).

Description

[Technical Field]

[0001] The present invention relates to a dispensing gun (or dispenser) for cartridges. In particular, the dispensing gun of the present invention is advantageously suitable for delivering paste-like materials contained in cartridges. The present invention also relates to the use of the dispensing gun in the medical field, in particular in the dental or orthopedic field. [Background technology]

[0002] Cartridges suitable for mixing and dispensing multi-component dental restorative materials for placement in a patient's teeth are of particular interest in dental restorative applications. Dental restorative materials typically consist of a powder component and a liquid component, which are mixed to form a dental cement. In particular, cartridges for dental restorative applications have been developed in which specific amounts of powder and liquid components are pre-measured and stored in separate chambers to prevent accidental mixing of the two components. In such cartridges, the components can be released from the separate chambers at desired times and mechanically mixed together to form the dental cement that is dispensed from the cartridge.

[0003] Dispensing the material contained in the cartridge generally requires a dispensing tool, and in particular in the dental field, several dispensing guns have been developed for dispensing dental materials contained in cartridges.

[0004] For example, WO95 / 00078 discloses a dispensing gun having a cartridge holder for receiving a cartridge, but in WO95 / 00078 there is no means for locking the cartridge to the dispensing gun, and therefore the dispensing gun of WO95 / 00078 cannot ensure safe handling when operated by a physician.

[0005] Other dispensing devices, such as that disclosed in US2018 / 0185117, require the clinician to operate the device's lever several times to deliver the material contained in the cartridge. These dispensing devices are not ergonomic and often do not dispense the entire amount of material.

[0006] More specifically, the present invention aims to address these drawbacks by proposing a dispensing gun for dispensing material from a cartridge that is easy to operate while making the dispensing of material more reliable, in particular by reducing the risk of losing part of the material, and that also advantageously allows for the ejection of all the material contained in the cartridge in one stroke of the piston of the dispensing gun. Summary of the Invention

[0007] To this end, the subject of the present invention is a dispensing gun for cartridges, comprising a frame with a handle and an injection gate for connecting a cartridge, a lever with at least two teeth, and a piston (also called gun piston) with at least two notches, said cartridge preferably having a base area with at least two opposing locking wings, said injection gate being located in the distal part of the frame, - the dispensing gun is provided with means for locking the cartridge directly onto the injection gate; - the dispensing gun comprises means for forcing a gun piston within the cartridge such that material contained in the cartridge is expelled in a single piston stroke; - The dispensing gun is configured such that the lever assumes a starting state in which a first notch of the gun piston and a first tooth of the lever engage with each other so that the lever and the handle form an angle in the range of 80° to 120°, preferably 90°, before connecting a cartridge.

[0008] In a conventional manner, within the framework of the present invention, the terms "proximal" and "distal" refer to the position of a part of the dispensing gun relative to the operator (e.g., dentist), i.e., the term "proximal" refers to a position of the cartridge closer to the operator, while the term "distal" refers to a position farther from the operator.

[0009] According to one embodiment, the dispensing gun is further configured such that the lever has a final state in which, when the lever is pulled, a piston of the dispensing gun engages the cartridge, expelling all of the material initially contained in the cartridge, thereby dispensing the material while minimizing material loss.

[0010] According to one embodiment, the dispensing gun is configured such that the lever is maintained at a position between a start state and a final state, and further has an intermediate state in which the lever is ready to be used to extrude a material contained in a cartridge connected to the gun. Preferably, in the intermediate state, when the cartridge connected to the gun includes a piston, the gun piston is disposed near the cartridge piston. In the present invention, the term "near" refers to the relative positions of two elements (e.g., the relative positions of the gun piston and the cartridge piston) that are separated from each other by a distance of less than 10 mm, preferably less than 9, 8, 7, 6, 5, 4, 3, 2, or 1 mm. According to one embodiment, the term "near" refers to the relative positions of two elements (e.g., the relative positions of the gun piston and the cartridge piston) that are in direct contact with each other (i.e., the distance between them is zero). According to one embodiment, the expression "the distal end of the gun piston is near the proximal end of the cartridge piston" means that the surface of the distal end of the gun piston is at least partially or completely in contact with and covers the surface of the proximal end of the cartridge piston. In this way, the thrust force applied by the physician to the lever in the final state to expel the material from the cartridge is minimized. Advantageously, the dispensing gun is more ergonomic for the physician to handle and easier to use than existing guns.

[0011] According to one embodiment, the injection gate is configured to lock the cartridge having a base section with two opposing locking wings, and preferably the injection gate includes means for directly locking the outer sleeve of the cartridge via its two locking wings. In this manner, this particular configuration ensures proper positioning of the cartridge on the dispensing gun and provides a secure connection between the cartridge and the dispensing gun. As a result, the cartridge is held in place when the system (dispensing gun and cartridge) of the present invention is used and a thrust force is applied to deliver material.

[0012] According to one embodiment, the gun piston includes a rod configured to enter the interior volume of the cartridge when locked into the distal portion of the injection gate. In this way, during extrusion of the material, the gun piston effectively pushes the material toward the outlet nozzle of the cartridge, thereby extruding all of the material contained in the cartridge.

[0013] According to one embodiment, pivoting the lever from the starting position to the final position displaces the gun piston a distance in the range of 10 mm to 20 mm, preferably 14 mm to 16 mm, more preferably 15 mm to 18 mm. In this manner, pivoting the lever displaces the piston of the dispensing gun, so that when a cartridge is connected to the gun, the gun piston pushes against the cartridge piston, expelling all of the material contained in said cartridge. In the present invention, the term "in the range" is meant to include the ends of the range.

[0014] According to one embodiment, when the lever is in the actuated state, the distal end of the gun piston is positioned at the proximal end of the injection gate.

[0015] According to one embodiment, the frame comprises one or more ribs, preferably only one rib.

[0016] According to one embodiment, the dispensing gun includes a washer located behind a rib on the frame.

[0017] According to one embodiment, when the lever is in the intermediate state, the lever is maintained in a position between the start state and the final state by a spring plunger.

[0018] According to one embodiment, the injection gate comprises a proximal portion configured to connect to the distal end of the frame and a distal portion configured to connect and lock two opposing locking wings of the base section of the cartridge.

[0019] According to one embodiment, the frame is made of injection molded polymer and the injection gate is made of metal.

[0020] According to one embodiment, the injection gate is autoclavable and / or decontaminable. In this way, the injection gate can be easily cleaned and reused after use. In this invention, the term "autoclavable" refers to an object that can be sterilized in an autoclave. In this invention, the term "decontaminable" refers to an object that can be sterilized or cleaned to reduce or eliminate microorganisms present on the object.

[0021] Another object of the present invention refers to a system comprising a dispenser as defined above and a cartridge having a base section with two opposing locking wings. According to one embodiment, the inventive dispensing gun or the inventive system is useful in the dental or orthopedic field, preferably for bone or tooth restoration.

[0022] Another subject of the present invention is a method for dispensing material with a system comprising a cartridge having a base section with at least two opposing locking wings and a dispensing gun according to the present invention, the injection gate comprising a distal plate having an opening whose shape corresponds to the shape of the base section of the cartridge, the method comprising: - Before connecting the cartridge, under the action of the thrust applied to the lever, the lever and the handle must form an angle in the range of 80° to 120°, preferably approximately 90°, and the piston in the frame must be at a non-zero distance e from the distal end of the injection gate. x a first step of starting the dispensing gun, which includes placing the lever in a starting state in which a first notch of the piston and a first tooth of the lever are engaged with each other, such that a second step of locking a base section of the cartridge containing the material to be delivered to a distal portion of the injection gate; a third step of moving the piston of the dispensing gun to a position ready for use in extruding the material contained in the cartridge; a fourth step of dispensing the material contained in the cartridge, in which the piston is displaced within the cartridge so that all the material is expelled under the action of a thrust force applied to the lever until the lever is pulled (final state); The method includes:

[0023] Another subject of the invention is a method for dispensing a material contained in a cartridge by means of a dispensing gun as described above, comprising the steps of: - a first step of starting the dispensing gun of the present invention, which includes placing the lever in a starting state in which a first notch of the gun piston and a first tooth of the lever engage with each other so that the lever and the handle form an angle in the range of 80° to 120°, preferably approximately 90°, under the action of a thrust force applied to the lever; a second step of locking a base section of the cartridge containing the material to be delivered to a distal portion of the injection gate; a third step of moving the piston of the dispensing gun to a position ready for use in extruding the material contained in the cartridge; a fourth step of dispensing the material contained in the cartridge, in which the gun piston is displaced within the cartridge under the action of a thrust force applied to the lever until the lever is pulled (final state), preferably so that all the material is expelled in one stroke of the gun piston; The method includes:

[0024] Features and advantages of the present invention will become apparent from the following description of some embodiments of a dispensing gun according to the invention, given by way of example only and with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0025] [Figure 1] 1 is an exploded perspective view of a dispensing gun according to a first embodiment of the present invention. [Figure 2] 2 is a longitudinal cross-sectional view of the dispensing gun of the cartridge of FIG. 1 with the lever in an actuated state. [Figure 3] 3A is a side view of a dispensing gun of the present invention when the lever is in an intermediate state corresponding to a configuration in which the piston of the dispensing gun is in contact with the piston of the cartridge and ready to extrude material (FIG. 3A), and when the lever is in a final state corresponding to the end of material delivery (FIG. 3B). [Figure 4] FIG. 13 is a perspective view of an injection gate with means for safely connecting and locking the base section of a cartridge with two locking wings. [Figure 5] 1 is an exploded perspective view of a cartridge suitable for use in a dispensing gun according to a first embodiment of the present invention, suitable for mixing and dispensing a two-component material including a powder component and a liquid component. FIG. [Figure 6] 6 is a longitudinal cross-sectional view of the cartridge of FIG. 5 in an initial storage configuration of the cartridge. [Figure 7] 7 is a longitudinal cross-sectional view similar to FIG. 6, of the cartridge in a first operational configuration. [Figure 8] 7 is a longitudinal cross-sectional view similar to FIG. 6, with the cartridge in a second operational configuration. [Figure 9] 7 is a longitudinal cross-sectional view similar to FIG. 6, but with the cartridge in a dispensing configuration corresponding to the end of material delivery performed by the dispensing gun of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Dispensing Gun of the Present Invention FIG. 1 shows an exploded view of a dispensing gun 1 according to a first embodiment of the present invention, which is suitable for both locking the base section of a cartridge and then dispensing the material contained in the cartridge.

[0027] 1, dispensing gun 1 includes a frame 2 with a handle 21 and an injection gate 22 disposed at the distal end of frame 2. In this first embodiment, dispensing gun 1 includes a lever 3, a piston 4, a washer 51, a spring 52, a retaining ring 53, a spring plunger 54, and a pivot pin 23.

[0028] As can be seen in Figure 1, the frame 2 is gun-shaped and has a handle 21 that allows the physician to handle the dispensing gun with either the left or right hand. In the first embodiment of the dispensing device shown in Figures 1-3, the physician's palm must be placed over the handle 21 and the fingers of the physician's hand must be placed over the lever 3.

[0029] The lever 3 is attached to the frame 2 by a pivot pin 23, which connects the lever 3 to the frame 2 while allowing the lever 3 to move semicircularly around the axis of the pivot pin 23. To prevent friction between the pivot pin 23 and the lever 3, particularly when both the pivot pin 23 and the lever 3 are made of metal, the pivot pin may be surrounded by a protective sleeve 24. Preferably, the protective sleeve is made of a plastic material and has an open-ended cylindrical shape. The lever 3 includes a grip portion and a head. The head of the lever 3 includes one or more teeth 31. According to one embodiment, the head of the lever 3 includes 1, 2, 3, 4, 5, 6, or 7 teeth. According to one embodiment, the teeth on the head of the lever 3 are configured to cooperate with a gun piston 4. According to one embodiment, the gun piston 4 is a rod. According to one embodiment, the gun piston 4 includes one or more notches 41. According to one embodiment, the number of teeth 31 is the same as the number of notches 41. According to one embodiment, the gun piston 4 is a rod with at least two notches, preferably three to eight notches, more preferably seven notches, said notches being located in the central part of the gun piston 4.

[0030] As shown in Figures 2 and 3, when the dispensing gun is in use, the lever 3 successively assumes three distinct positions: a starting state (Figure 2), an intermediate state (Figure 3A), and a final state (Figure 3B).

[0031] The "starting state" in the present invention refers to the position of the lever 3 in which the first notch (41) of the gun piston (4) and the first tooth (31) of the lever (3) are engaged with each other so that the lever (3) and the handle (21) form an angle in the range of 80° to 120°, preferably approximately 90°, before connecting the cartridge. According to one embodiment, in the starting state, the lever (3) and the handle (21) form an angle of approximately 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95°, 96°, 97°, 98°, 99°, 100°, 101°, 102°, 103°, 104°, 105°, 106°, 107°, 108°, 109°, 110°, 111°, 112°, 113°, 114°, 115°, 116°, 117°, 118°, 119°, or 120°. According to one embodiment, the term "about" before a number means + or -10% of the value of said number, preferably + or -5% of this value, and more preferably + or -1% of this value. As seen in FIG. 2 , in the starting state, the distal end of the gun piston 4 is located at the proximal end of the injection gate 22. According to one embodiment, in the starting state, the distal end of the gun piston 4 is not within the internal volume of the injection gate 22. According to one embodiment, in the starting state, the rod of the gun piston 4 is not within the internal volume of the injection gate. According to one embodiment, in the starting state, the cartridge is not connected, held, and / or locked to the dispensing gun 1. According to one embodiment, the starting state is when the gun piston 4 is located within the frame 2 at a non-zero distance e from the distal end of the injection gate 22. x According to one embodiment, the distance e x is in the range of 1 mm to 17 mm, preferably 7 mm to 17 mm, more preferably 14 mm to 16 mm. x are 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, and 17mm.

[0032] In the present invention, the term "final state" refers to the position of the lever 3 when the lever 3 is fully pulled. As seen in FIG. 3B , in the final state, the longitudinal axis of the lever 3 is parallel to the longitudinal axis of the handle 21 of the dispensing gun. According to one embodiment, in the final state, pivoting the lever from the starting state to the final state results in maximum displacement of the gun piston 4 within the dispensing gun and / or maximum displacement of the piston of the cartridge locked to the dispensing gun. According to one embodiment, in the final state, pivoting the lever from the starting state to the final state preferably expels all of the material contained in the cartridge with one stroke of the gun piston 4 within the dispensing gun and / or one stroke of the piston of the cartridge locked to the dispensing gun.

[0033] 3A, the "intermediate state" refers to a position of the lever 3 between the start state and the final state defined above. According to one embodiment, in the intermediate state, the gun piston 4 engages the injection gate 22 and the distal end of the gun piston 4 is positioned outside the distal end of the injection gate 22. According to one embodiment, in the intermediate state, the cartridge is locked to the distal end of the injection gate and the distal end of the gun piston 4 is positioned close to, preferably in contact with, the piston of the cartridge, thus making the system ready to extrude material without extruding material.

[0034] 4, the injection gate 22 includes a distal plate 221 having an opening 222. The shape of the opening 222 corresponds to the shape of the base section of the cartridge. In this manner, the cartridge can engage with the injection gate 22 of the dispensing gun. According to one embodiment, the shape of the opening 222 corresponds to the shape of the base section of the cartridge having two opposing locking wings.

[0035] Injection gate 22 also includes means for locking a cartridge that has entered it. According to one embodiment, the means for locking a cartridge to dispensing gun 1 (and to injection gate 22) includes or consists of at least one hole in at least one side wall of distal plate 221 of injection gate 22. According to one embodiment, the means for locking a cartridge to dispensing gun 1 (and to injection gate 22) includes or consists of one hole 223 in each vertical side wall of distal plate 221 of injection gate 22. In this way, when a cartridge is pushed into the opening of distal plate 221 within the injection gate and the cartridge is rotated a quarter turn about its longitudinal axis, the locking wings of the cartridge fit into the holes in the two vertical side walls of injection gate 22, and the cartridge is safely locked to dispensing gun 1. According to one embodiment, the side walls of injection gate 22 have a thickness that is greater than the thickness of the base area and / or the locking wings of the cartridge.

[0036] cartridge The present invention also refers to a system including a dispensing gun 1 of the present invention and a cartridge 6. In the present invention, the cartridge may be any cartridge suitable for the dispensing gun 1 of the present invention. In particular, the cartridge may contain any suitable material that can be delivered by the dispensing gun 1 of the present invention; preferably, the material is a medical composition, such as a bone filler or a dental material. According to one embodiment, the cartridge may be a medical cartridge, such as a dental cartridge. According to one embodiment, the cartridge described in WO 2021 / 013752 is particularly suitable for use with the dispensing gun 1 of the present invention. According to one embodiment, the cartridge comprises a base region with at least one protrusion, a chamber for containing the material to be dispensed, a piston, and a dispensing nozzle. According to one embodiment, the cartridge comprises a base region having means for locking to the dispensing gun 1 of the present invention, preferably to the injection gate 22 of the dispensing gun 1. According to one embodiment, the means for locking the cartridge to the dispensing gun 1 includes or consists of at least two wings, preferably two opposing locking wings, present on the base region of the cartridge.

[0037] Figure 5 shows an exploded view of a cartridge 6 suitable for use with an instrument according to the present invention, suitable for both mixing and dispensing a two-component dental restorative material comprising a powder component and a liquid component. As can be seen in Figure 5, cartridge 6 comprises a continuous tubular member having a circular cross-section, configured for telescopic insertion while aligned along a longitudinal axis X-X'. In this embodiment, the tubular member of cartridge 6 includes, from outermost to innermost element, an outer sleeve 7, a barrel 8, a liquid receptacle 9, and a plunger 10.

[0038] The sleeve 7 comprises a body 71 including a proximal open end 711 and a distal end 712 defined by a distal wall 72 of the sleeve. A dispensing hole 73 is provided in the distal wall 72, from which extends a tubular dispensing nozzle 70 integrally formed with the body 71 of the sleeve. The thickness t of the peripheral wall 70a of the dispensing nozzle 70 is 70The diameter of the nozzle 70 decreases from the dispensing hole 73 toward the free end 70b of the nozzle. This particular geometry, in combination with the material of construction of the nozzle 70, which is a polymer, preferably a transparent polymer such as a clear amorphous copolyester in this example, allows the nozzle 70 to deform while maintaining a constant inner diameter when bent. In this manner, the nozzle 70 is steerable while still having a constant diameter for dispensing material.

[0039] The distal wall 72 of the sleeve 7 includes an internal piercing element 79 aligned with the dispensing hole 73, which is intended to pierce the frangible distal wall 89 of the barrel 8. The piercing element 79 is a tubular element that protrudes inwardly from the distal wall 72 of the sleeve so as to be in fluid communication with the dispensing hole 73. With this configuration, when the distal wall 89 of the barrel 8 is pierced, the tubular piercing element 79 forms a specialized passageway that guides the material contained in the barrel 8 directly to the dispensing hole 73, thereby limiting the loss of material within the space between the barrel 8 and the sleeve 7.

[0040] Inner diameter d of puncture element 79 79 is the diameter d of the dispensing hole 73 73 8. The opening in the distal wall 89 of the barrel 8 under the action of the piercing element 79 is thus of a size suitable to ensure a proper flow of the material to be dispensed. Around the piercing element 79, the sleeve 7 is provided with an annular (or ring-shaped) cavity 74, the bottom of which is formed by the inner surface of the distal wall 72, while the central wall of the ring is formed by the peripheral wall of the tubular piercing element 79 and the outer wall of the ring is formed by a beveled inner surface complementary to a corresponding beveled outer surface 88 of the barrel 8. These complementary beveled surfaces are designed to provide an efficient seal at the interface between the sleeve 7 and the barrel 8 adjacent the piercing element 79 and the dispensing hole 73, so as to restrict the passage of material in the space between the barrel 8 and the sleeve 7.

[0041] As shown in FIGS. 5 and 6, barrel 8 of cartridge 6 includes a proximal open end 81 and a distal end 82 defined by a frangible distal wall 89. Barrel 8 defines a chamber 85 configured to contain a powder component of a two-component dental restorative material. The material of construction of barrel 8 is selected to have a moisture content of 0.5 g / (m 2 ) at 23° C. and 85% RH at a film thickness of 100 μm to maintain a constant humidity level within chamber 85 suitable for protecting the hygroscopic powder component. 2 ·day). In particular, in this example, barrel 8 has a water vapor transmission rate (WVTR) of less than 0.4 g / (m) at 23°C and 85% RH when the film thickness is 100 μm. 2 According to another embodiment, the barrel 8 is made of a cyclic olefin copolymer (COC) having a WVTR of about 0.5 g / (m 2 ) at 23° C. and 85% RH at a film thickness of 100 μm. 2 The material is selected to have a water vapor transmission rate (WVTR) higher than 1000 kJ / s.

[0042] The distal wall 89 of the barrel 8 includes a central breakable portion surrounded by a sealing portion configured to cooperate with the inner surface of the distal wall 72 of the sleeve. Advantageously, the ratio of the surface area of ​​the breakable portion to the surface area of ​​the sealing portion is sized so that, after opening, the burrs of the opened breakable portion are completely separated from the dispensing hole 73 of the sleeve, while the support surface of the sealing portion forms a ring that is thin enough to limit the contact area. In this way, it is easier to achieve a seal with the distal wall 72 of the sleeve, and contact pressure is maximized to ensure a secure seal during dispensing of material. This configuration ensures proper flow of the dispensed material while limiting material loss.

[0043] The diameter of the breakable portion and the diameter of the piercing element 79 are also adjusted to maximize the breaking efficiency of the piercing element 79. For example, in the illustrated example, the diameter d 79 is approximately half the diameter d of the breakable portion. The breakable portion comprises six lines of weakness that are radially distributed in a star shape starting from the center of the distal wall 89. Each line of weakness extends beyond the thickness t of the remaining part of the distal wall 89. 89The thickness t is smaller than the center of the star. The stress is concentrated in the center of the star, so the destruction starts from the center of the star.

[0044] The arrangement of this line of weakness is configured to induce deformation of the corolla-shaped barrel distal wall 89 facing away from the dispensing nozzle 70 when acted upon by the piercing element 79. In practice, fracture of the distal wall 89 is obtained through displacement of the barrel 8 within the sleeve 7 along the longitudinal axis X-X' between a first position shown in Figure 6, in which the barrel distal wall 89 is at a distance e1 from the sleeve distal wall 72, and a second position (shown in Figure 9), in which the sealing portion of the barrel distal wall 89 contacts the inner surface of the sleeve distal wall 72, with the complementary bevel surfaces 83, 741 cooperating to provide a seal between the sleeve 7 and the barrel 8. As can be seen in Figures 7 and 8, the distance e1 between the barrel distal wall 89 and the sleeve distal wall 72 is greater than 0 in order to avoid unintentional dispensing of the material contained in the cartridge when the lever of the dispensing gun is in the start and / or intermediate states defined above. According to one embodiment, the distance e1 between the distal wall 89 of the barrel and the distal wall 72 of the sleeve is in the range of 1 mm to 5 mm, preferably 2 mm to 4 mm, and more preferably is about 3 mm.

[0045] The barrel 8 also includes two diametrically opposed tabs 88 near its proximal end 81. Each tab 88 is configured to receive within a corresponding housing 778 defined by locking wings 77 of the sleeve 7 located near the proximal end 711, thereby locking the barrel 8 in a first position relative to the sleeve 7. This locking configuration of the cartridge 6 ensures that the distal wall 89 of the barrel 8 remains a distance e1 from the distal wall 72 of the sleeve, thus allowing the cartridge 6 to be manipulated without risk of the distal wall 89 being punctured by the puncturing element 79, which allows the mixing step to be performed before the dispensing step.

[0046] Additionally, the barrel 8 includes an outer radial collar 86 configured to cooperate with an inner radial recess 756 formed by six clip members 75 circumferentially distributed within the body 71 of the sleeve 7. Cooperation between the outer radial collar 86 and the inner radial recess 756 allows the barrel 8 to be maintained in a first position relative to the sleeve 7 even when the tab 88 is disengaged from the housing 778, thus securing the cartridge 6 in the storage configuration even when the locking system 88 / 778 is not functional.

[0047] 8 , the body 71 of the sleeve 7 also comprises two diametrically opposed longitudinal grooves 78 near its proximal end 711, which are configured to guide the displacement of the tabs 88 of the barrel 8 as the barrel moves from the first position to the second position. The longitudinal grooves 78 provide positive guidance for the barrel 8 near the proximal end 711 as the barrel 8 moves towards the piercing element 79, while six guide ribs 76 circumferentially distributed within the body 71 of the sleeve provide positive guidance near the distal end 712. The guide means 76 and 78 improve the stability of the displacement of the barrel 8 to reach the dispensing configuration of the cartridge 6.

[0048] Chamber 85 of barrel 8 is sealed by a piston formed by the combination of liquid receptacle 9 and plunger 10. In this illustrative example, receptacle 9 is made of low-density polyethylene (LDPE), and plunger 10 is made of acrylonitrile butadiene styrene (ABS). Receptacle 9 has a proximal open end 91 and a distal end 92 defined by an openable distal wall 97. Receptacle 9 defines chamber 95 configured to contain a liquid component of a two-component dental restorative material. Distal wall 97 of receptacle 9 includes a detachable portion 98 attached to the remainder of the distal wall by an annular connector 99. Annular connector 99 includes a solid portion extending at an angle α of approximately 60° and a weakened portion having a thickness t less than the thickness t of the solid portion to form a hinge. This configuration allows the distal wall 97 of the receptacle 9 to be opened by breaking only the frangible portion, and thus the detachable portion 98 flips out of the receptacle 9 while still connected to the distal wall 97 of the receptacle 9 through the hinge formed by the solid portion.

[0049] The receptacle 9 is configured to move in sealing engagement within the chamber 85 of the barrel 8. To this end, the exterior of the receptacle 9 is provided with a peripheral sealing rib 93 configured to prevent a liquid component initially contained in the chamber 95 of the receptacle 9 from exiting towards the space between the barrel 8 and the receptacle 9 when the distal wall 97 of the receptacle opens and the receptacle 9 moves towards the distal wall 89 of the barrel.

[0050] In practice, the opening of the distal wall 97 of the receptacle 9 is obtained by a rod 109 extending distally from the distal wall 102 of the plunger 10. More precisely, the chamber 95 of the receptacle 9 is sealed by the plunger 10 movable within the chamber 95, the distal rod 109 of the plunger 10 being configured to apply pressure to the detachable portion 98 of the distal wall 97 of the receptacle. Prior to opening the distal wall 97, the powder component is sealed within the chamber 85 of the barrel 8, and the liquid component is sealed within the chamber 95 of the receptacle 9. The openable distal wall 97 of the receptacle can then be opened by applying pressure to the detachable portion 98 with the distal rod 109 of the plunger, and by applying vibration to the cartridge 6 in this operating configuration, either manually or by a vibrating mixer, the two components can be easily mixed at the desired time to produce the material to be dispensed.

[0051] The receptacle 9 comprises two inner circumferential grooves 96, 96′ configured to cooperate with two corresponding outer circumferential ribs 106, 106′ of the plunger 10 to maintain the plunger 10 at a distance e2 from the openable distal wall 97 of the receptacle 9 in the storage configuration of the cartridge 6. The cooperation between the inner circumferential grooves 96, 46′ and the outer circumferential ribs 96, 96′ is releasable under the action of a thrust force F0 applied to the proximal end 101 of the plunger 10, for example by an actuation machine, to reach the operating configuration of FIG. 7. The cooperating radial features 96, 106 and 96′, 106′ between the receptacle 9 and the plunger 10 enable the powder and liquid components to be separated, allowing the cartridge 6 to be secured in the storage configuration with the first component in the barrel chamber 85 and the second component in the receptacle chamber 95 without the risk of accidental mixing of the two components.

[0052] The barrel 8 also includes an inner circumferential groove 84 near its proximal end 81 that is configured to cooperate with an outer circumferential rib 94 of the receptacle 9 to maintain a distal wall 97 of the receptacle 9 at a specified distance from the distal wall 89 of the barrel 8 until a piston formed by the combination of the receptacle 9 and plunger 10 is moved toward the distal wall 89 of the barrel to dispense material. The cooperating radial features 84, 94 between the barrel 8 and the receptacle 9 enable a two-stage transition of the cartridge 6 to a dispensing configuration, obtained, for example, through the application of a thrust force F1 to the proximal end 101 of the plunger 10 by a dispensing gun of the present invention.

[0053] method The present invention also relates to a method for dispensing a material contained in a cartridge as defined above by means of a dispensing gun 1 according to the present invention as defined above, the method comprising the steps described below.

[0054] Initially, the dispensing gun 1 is in a start-up state as shown in FIG. 2, where the lever 3 moves the gun piston 4 to a distance e from the distal end of the injection gate 22 within the frame 2. x In this start-up configuration, the cartridge is not yet connected to the dispensing gun 1.

[0055] The base section of the cartridge is then pushed into the opening 222 of the injection gate 22. The opening 222 and the base section of the cartridge must have the same shape so that they fit together and the cartridge fits within the internal volume of the injection gate. The outer sleeve of the cartridge is then rotated a quarter turn along the longitudinal axis of the cartridge, locking each locking wing 77 into a hole in each vertical side wall of the distal plate 221 of the injection gate 22. In this way, when the dispensing gun is used with the cartridge, the locking wings 77 are held in place by the frame of the injection gate 22, ensuring safe handling for the physician.

[0056] After locking the cartridge to the dispensing gun 1, a thrust force F is applied to the lever 3 to pivot the lever 3 from the start state defined above to an intermediate state. Cooperation between the lever 3 and the gun piston 4 thus displaces the gun piston 4, engaging its distal end within the interior volume of the injection gate 22 to which the cartridge is locked, positioning the distal end of the gun piston 4 near the cartridge piston and ready to eject the cartridge material without performing an ejection. The intermediate state of the lever 3 is achieved by the action of the spring plunger 54. During this intermediate step, the barrel 8 is displaced from the first position to the second position relative to the sleeve 7 until the barrel's distal wall 89 contacts the sleeve's distal wall 72 and is broken by the piercing element 79. During this step, radial features 84, 94 between the barrel 8 and the receptacle 9 engage with each other, causing the barrel 8, receptacle 9, and plunger 10 to move together.

[0057] Finally, under the action of thrust F' on lever 3, gun piston 4 advances in the cartridge, and the distal end of gun piston 4 pushes against the piston of the cartridge formed by the combination of receptacle 9 and plunger 10, which is displaced relative to barrel 8, and in this step radial features 84, 94 between barrel 8 and receptacle 9 disengage from each other. In this way, the material to be dispensed is pushed as far as possible towards the dispensing nozzle of the cartridge, thus minimizing material loss.

[0058] Advantageously, the thrust force F' applied by the physician to lever 3 is slight and does not require the use of both hands. Advantageously, the amplitude of the physician's finger movement required to move lever 3 to expel material with the dispensing gun (i.e., to move lever 3 from the intermediate state to the final state) is small. Thus, the dispensing gun is more ergonomic and easier to use than conventional dispensing devices.

[0059] The invention is not limited to the examples described and shown, and in particular other materials and shapes than those mentioned above are contemplated for the components of the cartridge used in the dispensing gun according to the invention.

Claims

1. A dispensing gun (1) for a cartridge, said dispensing gun (1) comprising a frame (2) having a handle (21) and an injection gate (22) for connecting a cartridge (6) having a base area with at least two opposing locking wings, a lever (3) having at least two teeth (31), and a piston (4) having at least two notches (41), said injection gate (22) being located at a distal portion of said frame (2); the dispensing gun (1) comprises means for locking the cartridge directly to the injection gate (22); the dispensing gun (1) comprises means for pushing the piston (4) within the cartridge so that the material contained in the cartridge is expelled in a single piston stroke; The dispensing gun (1) is configured such that the lever (3) assumes a starting state in which a first notch (41) of the piston (4) and a first tooth (31) of the lever (3) are engaged with each other so that the lever (3) and the handle (21) form an angle in the range of 80° to 120° before the cartridge is connected; The injection gate (22) comprises a distal plate (221) having an opening (222) whose shape corresponds to the shape of a base section of a cartridge having two opposing locking wings that enable engagement of the cartridge within the injection gate (22) of the dispensing gun (1), and the injection gate (22) also comprises means for locking a cartridge that has entered the injection gate.

2. 2. The dispensing gun of claim 1, wherein the lever (3) is further configured to have a final state in which the lever (3) is pulled and a piston (4) of the dispensing gun engages with the cartridge, thereby expelling all of the material initially contained in the cartridge.

3. 3. The dispensing gun of claim 1 or claim 2, wherein the lever (3) is configured to further assume an intermediate state in which the lever (3) is maintained in a position between the starting state and the final state, the piston (4) is in close contact with the piston of the cartridge, and the dispensing gun is ready to be used to extrude the material contained in the cartridge.

4. A dispensing gun as described in any one of claims 1 to 3, wherein the injection gate (22) is provided with means for directly locking the outer sleeve (7) of the cartridge (6) via two locking wings (77) of the cartridge.

5. The dispensing gun according to any one of claims 1 to 4, wherein the piston (4) comprises a rod configured to enter the internal volume of the cartridge when locked to the distal portion of the injection gate (22).

6. Dispensing gun according to any one of claims 1 to 5, wherein pivoting of the lever (3) from a starting state to a final state causes a displacement of the piston (4) in the range of 10 mm to 20 mm.

7. The dispensing gun according to any one of claims 1 to 6, wherein when the lever (3) is in an actuated state, the distal end of the piston (4) is located at the proximal end of the injection gate (22).

8. The dispensing gun of any one of claims 1 to 7, wherein the frame (2) comprises one or more ribs, and the dispensing gun comprises a washer (51) located behind the rib of the frame.

9. A dispensing gun as described in claim 3, or any one of claims 4 to 8 in combination with claim 3, wherein when the lever (3) is in the intermediate state, the lever (3) is maintained in a position between the starting state and the final state by a spring plunger.

10. 5. The dispensing gun of claim 4, wherein the injection gate (22) comprises a proximal portion configured to connect to a distal end of the frame (2) and a distal portion configured to connect and lock two opposing locking wings of a base section of the cartridge.

11. The dispensing gun of any one of claims 1 to 10, wherein the frame (2) is made of injection molded polymer and the injection gate (22) is made of metal.

12. The dispensing gun of any one of claims 1 to 11, wherein the dispensing gun is autoclavable and / or decontaminable.

13. A system comprising a dispensing gun according to any one of claims 1 to 12 and a cartridge (6) having a base section with two opposing locking wings (77).

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