Patent Application
20240058097
The present invention relates to a dispensing gun (or dispenser) for a cartridge. Especially, the dispensing gun of the invention is advantageously suitable for delivering a pasty material contained in a cartridge. The present invention also concerns the use of the dispensing gun in the medical field, in particular in the dental field or in the orthopedic field.
Cartridges suitable for the mixing and dispensing of material are particularly interesting for dental restoration applications, in order to mix a multi-component dental restoration material and dispense it on a tooth of a subject. A dental restoration material classically comprises a powder component and a liquid component, which are mixed to form a dental cement. Especially, cartridges have been developed for dental restoration applications, in which certain amounts of a powder component and of a liquid component are previously weighed and accommodated in isolated chambers so as to prevent any accidental mixing of the two components. In such cartridges, the components can be released from the isolated chambers at a desired time and mechanically mixed with each other to form a dental cement that is dispensed from the cartridge.
For dispensing the material contained in the cartridge, a dispensing device is generally required. Especially, in the dental field, several dispensing guns have been developed for dispensing a dental material contained in a cartridge.
For example, WO95/00078 discloses a dispensing gun having a cartridge holder for receiving a cartridge. In WO95/00078, there is no means for locking the cartridge to the dispensing gun so that the dispensing gun of WO95/00078 cannot guarantee a safely handling when the practitioner operates.
Other dispensing devices, such as that disclosed in US2018/0185117, require the practitioner to operate the lever of the device several times for delivering the material contained in the cartridge. These dispensing devices are not ergonomic and often are not able to dispense the whole amount of the material.
It is these drawbacks that the invention is intended more particularly to remedy by proposing a dispensing gun for dispensing a material from a cartridge which is easy to operate while making the dispensing of the material more secure, in particular by limiting the risks of loss of a part of the material. The dispensing gun also advantageously allows the extrusion of the entire material contained inside the cartridge, in one single stroke of the piston of the dispensing gun.
For this purpose, a subject of the invention is a dispensing gun for a cartridge comprising a frame having a handle, an injection gate for connecting a cartridge, preferably said cartridge having a base section with at least two opposite locking wings, said injection gate being located at the distal part of the frame, a lever comprising at least two teeth and a piston (also called gun piston) comprising at least two notches, wherein:
In a conventional manner, within the frame of the invention, the terms “proximal” and “distal” refer to a position of portions of the dispensing gun with reference to an operator (e.g. a dentist), i.e. the term “proximal” refers to a position closer to the operator of the cartridge, while the term “distal” refers to a position that is more distant from the operator.
According to one embodiment, the dispensing gun is configured so that the lever further comprises a final state in which the lever is depressed and the piston of the dispensing gun is engaged in the cartridge so that the material initially contained in the cartridge has been entirely extruded. In this way, the material is dispensed while limiting the material losses.
According to one embodiment, the dispensing gun is configured so that the lever further comprises an intermediate state in which the lever is maintained in a position between the actuating state and the final state, so that the dispensing gun is ready to use for extruding the material contained in a cartridge connected to the gun. Preferably, in the intermediate state, when the cartridge connected to the gun comprises a piston, the gun piston is positioned close to the piston of the cartridge. In the present invention, the term “close to” refers to the relative position of two elements (for example, the relative position of the gun piston to the cartridge piston) separated each other of a distance lower than 10 mm, preferably lower than 9, 8, 7, 6, 5, 4, 3, 2 or 1 mm. According to one embodiment, the term “close to” refers to the relative position of two elements (for example, the relative position of the gun piston to the cartridge piston) in direct contact with each other (that-is-to say the distance between the gun piston and the cartridge piston is zero). According to one embodiment, the expression “the distal end of the gun piston is close to the proximal end of the cartridge piston” means that the surface of the distal end of the gun piston is in contact and covers at least partially or entirely the surface of the proximal end of the cartridge piston. In this way, the thrust force to be applied by the practitioner on the lever in the final state for extruding the material from the cartridge is minimized. Advantageously, the handling of the dispensing gun for the practitioner is more ergonomic and the use of the dispensing gun is easier than with existing guns.
According to one embodiment, the injection gate is configured for locking a cartridge which has a base section with two opposite locking wings, preferably the injection gate comprises means for directly locking the external sleeve of the cartridge via its two locking wings. In this way, this particular arrangement ensures a correct positioning of the cartridge on the dispensing gun and provides a safely connection between the cartridge and the dispensing gun. Consequently, when the system of the invention (dispensing gun with cartridge) is used and when a thrust force is applied for delivering the material, the cartridge holds in place.
According to one embodiment, the gun piston comprises a rod configured to be received in the internal volume of the cartridge when locked on the distal part of the injection gate. In this way, during the extrusion of the material, the gun piston efficiently pushes the material in the outlet nozzle of the cartridge and all the material contained in the cartridge is extruded.
According to one embodiment, the pivot of the lever from the actuating state to the final state displaces the gun piston of a distance comprised in the range from 10 mm to 20 mm, preferably from 14 mm to 16 mm; more preferably from 15 mm to 18 mm. In this way, the pivot of the lever leads to the displacement of the piston of the dispensing gun so that, when a cartridge is connected to the gun, the gun piston pushes the cartridge piston and leads to the extrusion of the entire material contained in said cartridge. In the present invention, the term “comprised in the range” means that the range terminals are included.
According to one embodiment, when the lever is in an actuating state, the distal end of the gun piston is located at the proximal end of the injection gate.
According to one embodiment, the frame comprises one or more ribs, preferably comprises only one rib.
According to one embodiment, the dispensing gun comprises a washer positioned behind the frame's rib.
According to one embodiment, when the lever is in the intermediate state, the lever is maintained in a position between the actuating state and the final state by a spring plunger.
According to one embodiment, the injection gate comprises a proximal part configured to connect the distal end of the frame and a distal part configured to connect and lock the two opposite locking wings of the base section of the cartridge.
According to one embodiment, the frame is made of an injected-molded polymer and the injection gate is made of metal.
According to one embodiment, the dispensing gate is autoclavable and/or decontaminable. In this way, the dispensing gate may be easily washed after use and may be reused. In the present invention, the term “autoclavable” refers to an object that may be sterilized in an autoclave. In the present invention, the term “decontaminable” refers to an object that may be sterilized or washed so that to decrease or delete the micro-organisms present on said object.
Another object of the invention refers to a system comprising the dispenser as defined above and a cartridge having a base section with two opposite locking wings. According to one embodiment, the dispensing gun of the invention or the system of the invention is useful in the dental field, or in the orthopedic field; preferably for bone or dental restoration.
Another subject of the invention is a method of dispensing a material by a system comprising a cartridge having a base section with at least two opposite locking wings and a dispensing gun according to the present invention, in which the injection gate comprises a distal plate with an aperture whose shape corresponds to the shape of the base section of the cartridge, said method comprising steps in which:
Another subject of the invention is a method of dispensing a material comprised in a cartridge by means of the dispensing gun as described above, comprising the following steps:
Features and advantages of the invention will become apparent from the following description of several embodiments of a dispensing gun according to the invention, this description being given merely by way of example and with reference to the appended drawings in which:
As visible in
As seen in
The lever 3 is attached to the frame 2 thanks to a pivot pin 23 allowing to connect the lever 3 to the frame 2 while keeping the ability for the lever 3 to move in a hemi-circular movement about the axis of the pivot pin 23. The pivot pin may be surrounded by a protecting sleeve 24 in order to avoid friction between the pivot pin 23 and the lever 3, especially when the pivot pin 23 and the lever 3 are both in metal. Preferably the protecting sleeve is made from plastic material and has a shape of open-ended cylinder. The lever 3 comprises a grip part and a head. The head of the lever 3 comprises one or more teeth 31. According to one embodiment, the head of the lever 3 comprises 1, 2, 3, 4, 5, 6 or 7 teeth. According to one embodiment, the teeth of the head of the lever 3 are configured for cooperating with the gun piston 4. According to one embodiment, the gun piston 4 is a rod. According to one embodiment, the gun piston 4 comprises 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 comprising at least two notches, preferably from 3 to 8 notches, more preferably 7 notches, said notches being located in the central part of the gun piston 4.
As presented in
The “actuating 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 together prior to connecting the cartridge so that the lever (3) and the handle (21) form an angle ranging from 800 to 120°, preferably of almost 90°. According to one embodiment, in the actuating state, the lever (3) and the handle (21) form an angle of about 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°, 1190 or 120°. According to one embodiment, the term “about” preceding a figure means plus or less 10% of the value of said figure, preferably more or less than 5% of this value, more preferably more or less than 1% of this value. As seen in
The “final state” in the present invention refers to the position of the lever 3 in which the lever 3 is fully depressed. As seen in
As visible in
As presented in
The injection gate 22 also comprises means for locking the cartridge upon received inside the injection gate 22. According to one embodiment, means for locking the cartridge to the dispensing gun 1 (and to the injection gate 22) comprise or consist of at least one hole on at least one side wall of the distal plate 221 of the injection gate 22. According to one embodiment, means for locking the cartridge to the dispensing gun 1 (and to the injection gate 22) comprise or consist of one hole 223 on each vertical side wall of the distal plate 221 of the injection gate 22. In this way, when the cartridge is pushed inside the injection gate through the aperture on the distal plate 221, then rotating the cartridge a quarter turn about the longitudinal axis of the cartridge leads to displace the locking wings of the cartridge inside the two holes of the vertical side walls of the injection gate 22 and leads to safely lock the cartridge on the dispensing gun 1. According to one embodiment, the side walls of the injection gate 22 have a thickness higher than the thickness of the base section and/or of the locking wings of the cartridge.
The present invention also refers to a system comprising the dispensing gun 1 of the invention and a cartridge 6. In the present invention, the cartridge may be any cartridge suitable with the dispensing gun 1 of the invention. Especially, the cartridge may contain any suitable material able to be delivered with the dispensing gun 1 of the invention, preferably the material is a medical composition such as for example a bone filling material 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 WO2021/013752 is particularly suitable to be used with the dispensing gun 1 of the invention. According to one embodiment, the cartridge comprises a base section with at least one protrusion, a chamber containing the material to be dispensed, a piston and a dispensing nozzle. According to one embodiment, the cartridge comprises a base section with means to be locked in the dispensing gun 1 of the invention, preferably on the injection gate 22 of the dispensing gun 1. According to one embodiment, means of the cartridge to be locked in the dispensing gun 1 comprise or consist of at least two wings located on the base section of the cartridge, preferably two opposite locking wings.
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. The distal wall 72 is provided with a dispensing hole 73, from which extends a tubular dispensing nozzle 70 formed in one piece with the body 71 of the sleeve. The thickness t70 of the peripheral wall 70a of the dispensing nozzle 70 decreases from the dispensing hole 73 toward a free end 70b of the dispensing nozzle. Thanks to this specific geometry combined to the constitutive material of the dispensing nozzle 70, which is a polymer, preferably a transparent polymer such as a transparent amorphous copolyester in this example, the dispensing nozzle 70 is deformable while being capable of retaining a constant internal diameter even when it is bent. In this way, the dispensing nozzle 70 is steerable while having a constant diameter for the dispensing of material.
The distal wall 72 of the sleeve 7 comprises an internal piercing element 79 in the alignment of the dispensing hole 73, which is intended to break a breakable distal wall 89 of the barrel 8. The piercing element 79 is a tubular element projecting internally from the distal wall 72 of the sleeve so as to be in fluid communication with the dispensing hole 73. Thanks to this arrangement, once the distal wall 89 of the barrel 8 has been broken, the tubular piercing element 79 forms a privileged passageway guiding the material contained in the barrel 8 directly to the dispensing hole 73, which limits the losses of material in the interspace between the barrel 8 and the sleeve 7.
The inner diameter d79 of the piercing element 79 is slightly higher than the diameter d73 of the dispensing hole 73. In this way, the opening created in the distal wall 89 of the barrel 8 under the action of the piercing element 79 has a size suitable to ensure a proper flow of the material to be dispensed. Around the piercing element 79, the sleeve 7 comprises an annular (or ring-shaped) cavity 74 whose bottom 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 external wall of the ring is formed by a beveled inner surface complementary to a corresponding beveled outer surface 88 of the barrel 8. The complementary beveled surfaces are designed to provide an efficient sealing at the interface between the sleeve 7 and the barrel 8 adjacent to the piercing element 79 and the dispensing hole 73, so as to limit the passage of material in the interspace between the barrel 8 and the sleeve 7.
As visible in
The distal wall 89 of the barrel 8 comprises 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 such that, after opening, the fins of the open breakable portion leave the dispensing hole 73 of the sleeve completely cleared, while the bearing surface of the sealing portion is a sufficiently thin ring to limit the contact area. In this way, the seal is easier to achieve with the distal wall 72 of the sleeve and the contact pressure is maximized to ensure sealing during the dispensing of the material. This arrangement ensures a proper flow of the material to be dispensed while limiting the material losses.
The diameters of the breakable portion and the piercing element 79 are also adjusted to maximize the breakage efficiency of the piercing element 79. For example, in the illustrated example, the diameter d79 of the piercing element 79 is of the order of half the diameter d of the breakable portion. The breakable portion comprises six weakened lines distributed radially in a star shape, starting from a central portion of the distal wall 89. Each weakened line has a thickness t lower than the thickness t89 of the rest of the distal wall 89. The central portion of the star makes it possible to have a stress concentration so that the breaking starts in the center of the star.
This arrangement of the weakened lines is configured to guide a deformation of the distal wall 89 of the barrel, when it is submitted to the action of the piercing element 79, in a corolla shape oriented away from the dispensing nozzle 70. In practice, the rupture of the distal wall 89 is obtained through a displacement of the barrel 8 in the sleeve 7 along the longitudinal axis X-X′ between a first position, visible in
The barrel 8 also comprises two diametrically opposed tabs 88 near its proximal end 81. Each tab 88 is configured to be received in a corresponding housing 778 defined by a locking wing 77 of the sleeve 7 arranged near the proximal end 711, so as to lock the barrel 8 in the first position with respect to the sleeve 7. This locked configuration of the cartridge 6 ensures that the distal wall 89 of the barrel 8 remains at the distance e1 from the distal wall 72 of the sleeve, so that the cartridge 6 can be manipulated without any risk of the distal wall 89 being pierced by the piercing element 79, which makes it possible to implement a mixing step prior to the dispensing step.
In addition, the barrel 8 comprises an outer radial collar 86 configured to cooperate with inner radial recesses 756 formed by six clipping members 75 distributed circumferentially inside the body 71 of the sleeve 7. The cooperation between the outer radial collar 86 and the inner radial recesses 756 makes it possible to keep the barrel 8 in the first position with respect to the sleeve 7 even when the tabs 88 are disengaged from the housings 778, thus allowing the cartridge 6 to be secured in a storage configuration even when the locking system 88/778 is not active.
As can be seen particularly in
The chamber 85 of the barrel 8 is sealed by means of a piston formed by the combination of the liquid receptacle 9 and the plunger 10. In this illustrative example, the receptacle 9 is made of low-density polyethylene (LDPE) and the plunger 10 is made of acrylonitrile butadiene styrene (ABS). The receptacle 9 comprises a proximal open end 91 and a distal end 92 defined by an openable distal wall 97. The receptacle 9 delimits a chamber 95 configured to receive the liquid component of the two-component dental restoration material. The distal wall 97 of the receptacle 9 comprises a detachable portion 98 attached to the rest of the distal wall by an annular connecting part 99. The annular connecting part 99 comprises a solid portion extending over an angle α of the order of 60°, and a weakened portion having a thickness t less than the thickness t of the solid portion, so as to form a hinge. This arrangement makes it possible to open the distal wall 97 of the receptacle 9 by rupturing only the weakened portion, so that the detachable portion 98 flips out of the receptacle 9 while remaining connected to the distal wall 97 of the receptacle 9 through the hinge formed by the solid portion.
The receptacle 9 is configured to move in sealing engagement in the chamber 85 of the barrel 8. To this end, the receptacle 9 is provided externally with a peripheral sealing rib 93 configured to prevent the passage of the liquid component, initially contained in the chamber 95 of the receptacle 9, toward the interspace between the barrel 8 and the receptacle 9, when the distal wall 97 of the receptacle is open and the receptacle 9 is moved towards the distal wall 89 of the barrel.
In practice, the opening of the distal wall 97 of the receptacle 9 is obtained thanks to 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 means of the plunger 10, which is movable in the chamber 95 and whose distal rod 109 is configured to apply a pressure on the detachable portion 98 of the distal wall 97 of the receptacle. Before the opening of the distal wall 97, the powder component is hermetically received in the chamber 85 of the barrel 8 and the liquid component is hermetically received in the chamber 95 of the receptacle 9. The two components can then be easily mixed together at a desired time, so as to form the material to be dispensed, by opening the openable distal wall 97 of the receptacle through application of a pressure on the detachable portion 98 with the distal rod 109 of the plunger and applying a vibration to the cartridge 6 in this activated configuration, either manually or by means of a vibration mixer.
The receptacle 9 comprises two inner peripheral grooves 96, 96′ configured to cooperate with two corresponding outer peripheral ribs 106, 106′ of the plunger 10 to keep the plunger 10 at a distance e2 from the openable distal wall 97 of the receptacle 9 in a storage configuration of the cartridge 6. The cooperation between the inner peripheral grooves 96, 46′ and the outer peripheral ribs 96, 96′ is releasable under the effect of a thrust force F0 applied on the proximal end 101 of the plunger 10, e.g. by means of an activation machine so that to reach the activated configuration in
The barrel 8 also comprises an inner peripheral groove 84 near its proximal end 81, which is configured to cooperate with an outer peripheral rib 94 of the receptacle 9 to keep the distal wall 97 of the receptacle 9 at a distance from the distal wall 89 of the barrel 8 before the piston formed by the combination of the receptacle 9 and the plunger 10 is moved towards the distal wall 89 of the barrel for the dispensing of the material. The cooperating radial features 84, 94 between the barrel 8 and the receptacle 9 make it possible to have a two-step transition of the cartridge 6 towards the dispensing configuration, obtained through the application of a thrust force F1 on the proximal end 101 of the plunger 10, e.g. by means of the dispensing gun of the invention.
The present invention also concerns a method of dispensing a material contained in a cartridge as defined above, by means of the dispensing gun 1 according to the invention as defined above, and comprises steps as described below.
Initially, the dispensing gun 1 is in the actuating state as shown in
Then, the base section of the cartridge is pushed inside the aperture 222 of the injection gate 22. The aperture 222 and the base section of the cartridge must have the same shape in order to fit together and enable the cartridge to be received in the inner volume of the injection gate. After that, the external sleeve of the cartridge is turned a quarter turn along the longitudinal axis of the cartridge in order to lock each locking wing 77 in the hole of each vertical side walls 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 retained by the frame of the injection gate 22, ensuring a safely handling for the practitioner.
After locking the cartridge on the dispensing gun 1, a thrust force F is applied on the lever 3 in order to pivot the lever 3 from the actuating state to the intermediate state as defined above. In this manner, the cooperation between the lever 3 and the gun piston 4 leads to the displacement of the gun piston 4 so that the distal end of the gun piston 4 is engaged in the inner volume of the injection gate 22 on which is locked the cartridge and so that the distal end of the gun piston 4 is close to the piston of the cartridge, ready to extrude the material of the cartridge but without implementing extrusion. The intermediate state of the lever 3 is achieved thanks to the action of the spring plunger 54. During this intermediate step, the barrel 8 is displaced relative to the sleeve 7 from the first position to the second position, until the distal wall 89 of the barrel is in contact with the distal wall 72 of the sleeve and broken by the piercing element 79. In this step, the radial features 84, 94 between the barrel 8 and the receptacle 9 are mutually engaged so that the barrel 8, the receptacle 9 and the plunger 10 move integrally with one another.
Finally, under the action of a thrust force F′ on the lever 3, the gun piston 4 advances inside the cartridge so that the distal end of the gun piston 4 pushes the piston of the cartridge formed by the combination of the receptacle 9 and the plunger 10 which is displaced relative to the barrel 8, the radial features 84, 94 between the barrel 8 and the receptacle 9 being mutually disengaged in this step. In this way, the material to be dispensed is pushed as far as possible towards the dispensing nozzle of the cartridge, thus limiting the losses of material.
Advantageously, the thrust force F′ to be applied by the practitioner on the lever 3 is slight and does not require the use of the two hands. Advantageously, the movement of the fingers of the practitioner to moves the lever 3 for extruding the material with the dispensing gun (i.e. for moving the lever 3 from the intermediate state to the final state) is of reduced amplitude. Thus, the dispensing gun is more ergonomic and easier to use than conventional dispensing devices.
The invention is not limited to the examples described and shown. In particular, other materials and shapes than those described above can be considered for the constitutive members of a cartridge to be used with a dispensing gun according to the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21305075.0 | Jan 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/051393 | 1/21/2022 | WO |
