Syringe

Abstract

The invention relates to a syringe, in particular for dispensing flowable dental materials, comprising a syringe housing, at least two storage chambers (12 and 14) for dental materials, which lie transversely adjacent to each other as viewed in the dispensing direction, and a mixing device (36), which has two mixing channels (54, 56, 58, and 60), wherein each mixing channel is connected to the outlet of a storage chamber (12 and 14). The mixing device (36) has a mixing zone (80), which is connected to a pre-mixing zone (64). The pre-mixing zone (64) has two inlets, one for each of the dental materials to be mixed, and an outlet, wherein the inlets point toward each other. The outlet of the pre-mixing zone (64) extends perpendicularly to the inlets. The inlet of the mixing zone (80) is connected to the outlet of the pre-mixing zone (64). The mixing zone (80) has an impact element for deflecting the pre-mixed flow of the dental materials to an outlet of the mixing zone (80).

Claims

1. A syringe for dispensing flowable dental materials, comprising a syringe housing, at least two storage chambers (12 and 14) for dental materials, which lie transversely adjacent to each other as viewed in the dispensing direction, and a mixing device (36), which has at least two mixing channels (54, 56, 58, and 60), wherein each mixing channel is connected to an outlet of a storage chamber (12 and 14), characterized in that the mixing device (36) has a mixing zone (80), which is connected to a pre-mixing zone (64) and in that the pre-mixing zone (64) has two inlets, one for each of the dental materials to be mixed, and an outlet, wherein the inlets point toward each other and the outlet of the pre-mixing zone (64) extends perpendicularly to the inlets, and in that an inlet of the mixing zone (80) is connected to the outlet of the pre-mixing zone (64) and in that the mixing zone (80) has an impact element which is configured to deflect the pre-mixed flow of the dental materials to an outlet of the mixing zone (80), and in that a deflection zone is disposed between the impact element and a cannula channel.

2. The syringe as claimed in claim 1, characterized in that in the pre-mixing zone (64) the mixing device (36) comprises a flow deflection which is configured in an acute-angled manner.

3. The syringe as claimed in claim 2, characterized in that the deflection in the pre-mixing zone (64) is effected in a plane relative to which the deflection in the mixing zone (80) forms a third dimension.

4. The syringe as claimed in claim 1, characterized in that the pre-mixing zone comprises two pre-mixing zones (64) that are arranged opposite each other, and in that at least one of the at least two mixing channels extends between each of the two pre-mixing zone (64) and each storage chamber outlet.

5. The syringe as claimed in claim 1, characterized in that storage chamber outlets comprise a circular cross section and/or that the at least two mixing channels (54, 56, 58, and 60) comprise a rectangular cross section and/or that the impact element (20) comprises a pyramid-shaped or cone-shaped or truncated cone-shaped or truncated pyramid-shaped cross section.

6. The syringe as claimed in claim 1, characterized in that the at least two mixing channels (54, 56, 58, and 60) extend from each outlet of the storage chamber (12 and 14), which at least two mixing channels diverge from each other.

7. The syringe as claimed in claim 1, characterized in that flow areas for the dental materials comprise a constant cross-sectional area starting from the storage chamber (12 and 14) to the mixing zone (80) and that the flow areas are configured free from discontinuities and wake spaces.

8. The syringe as claimed in claim 1, characterized in that each mixing channel comprises a length/diameter ratio of more than 2:1 between the outlet and the pre-mixing zone (64), in a branched area.

9. The syringe as claimed in claim 8, characterized in that the length/diameter ratio is between 3:1 and 10:1, between the outlet and the pre-mixing zone (64), in the branched area.

10. The syringe as claimed in claim 8, characterized in that the length/diameter ratio is between 4:1 and 6:1, between the outlet and the pre-mixing zone (64), in the branched area.

11. The syringe as claimed in claim 1, characterized in that the pre-mixing zone comprises two pre-mixing zones (64) and directions of flow of the dental materials between the two pre-mixing zones (64) point toward each other and toward the mixing zone (80).

12. The syringe as claimed in claim 1, characterized in that to the outlet of the mixing zone (80) a cannula (26) is connected which comprises a cannula channel (24) having a front tip with a small cannula tube (52) mounted thereon.

13. The syringe as claimed in claim 12, wherein the small cannula tube (52) is rotatable.

14. The syringe as claimed in claim 1, characterized in that a small cannula tube (52) is mounted in a slidably movable manner in a cannula (26) down-stream of a cannula channel (24) which is attached to the outlet of the mixing zone (80), wherein the small cannula tube (52) and the cannula channel (24) have diameters which differ from each other by less than 30%.

15. The syringe as claimed in claim 14, characterized in that the small cannula tube (52) is mounted in a slidably movable and spring loaded manner relative to the cannula channel (24), wherein the spring force points away from the mixing zone (80) and the sliding movability of the small cannula tube (52) relative to the cannula (26) is limited by stops.

16. The syringe as claimed in claim 14, wherein the small cannula tube (52) and the cannula channel (24) have diameters which differ from each other by less than 10%.

17. The syringe as claimed in claim 1, characterized in that the syringe (10) comprises two drives for dispensing material which can be actuated simultaneously and independently of one another, for dispensing material by pressing a small cannula tube (52) into a cannula (26) and for dispensing material by actuating an actuation element which acts on a shared piston drive for the storage chambers (12 and 14).

18. The syringe as claimed in claim 1, characterized in that at said deflection zone (30) inclined surfaces and baffles surround an inlet of the cannula channel (24) and point toward the impact element (20).

19. The syringe as claimed in claim 18, characterized in that the deflection zone (30) is configured as a truncated cone-shaped recess in a cannula (26) which extends across the mixing zone (80) and the impact element (20) and has a larger flow area than the cannula channel (24).

20. The syringe as claimed in claim 18, characterized in that normals of baffles which surround a cannula channel (24) of a cannula (26) extend parallel to the axis (22) of the cannula channel (24).

21. A syringe for dispensing flowable dental materials, comprising a syringe housing, at least two storage chambers (12 and 14) for the dental material, which lie transversely adjacent to each other as viewed in the dispensing direction, and a mixing device (36), which has at least two mixing channels (54, 56, 58, and 60), wherein each mixing channel is connected to the outlet of the storage chamber (12 and 14), characterized in that the mixing device (36) has a mixing zone (80) which is connected to a pre-mixing zone (64), and in that the mixing zone (80) has an impact element (20) for deflecting which is configured to deflect the pre-mixed flow of dental materials toward an outlet of the mixing zone (80), and in that a dosing device is configured such that it can be actuated by an actuation element for the shared piston drive of the pistons of the storage chamber independently of a pushing tip comprising a small cannula tube (52) which is mounted in or to a cannula (26) in a slidably movable manner, said cannula being connected to the outlet of the mixing zone (80), and in that a deflection zone is disposed between the impact element and a cannula channel.

Description

(1) FIG. 1 shows a sectional view of a part of an inventive syringe by showing the parts which are important for the invention;

(2) FIG. 2 shows a front view of an insert element in order to illustrate the embodiment according to FIG. 1 by showing the mixing channels, the pre-mixing zone and the mixing zone;

(3) FIG. 3 shows a sectional view of the insert element by showing the impact element;

(4) FIG. 4 shows a view of the partial flows of the mixing channels, the pre-mixing zone and the mixing zone according to the embodiment of FIG. 1; and

(5) FIG. 5 shows a sectional view of a modified embodiment of the inventive syringe.

(6) FIG. 6 shows a sectional view of a part of the inventive syringe.

(7) FIG. 7A shows a cross-sectional view taken at line C-C of FIG. 2.

(8) FIG. 7B shows a cross-sectional view taken at line D-D of FIG. 2.

(9) The syringe 10 illustrated in FIG. 1 comprises storage chambers 12 and 14 which are illustrated in a broken up view and which serve to receive dental materials. As dental materials of this type mixtures of the following material can be used:

(10) Mixture of bis-acrylamide derivative, water, alcohol, bis-methacrylamide dihydrogen phosphate, acrylamide amino acid, highly dispersed silicon dioxide, initiators, catalysts and potassium fluoride.

(11) It is to be understood that this list is not to be understood as an exhaustive list and that other materials can also be used.

(12) On the outlet side of the storage chambers outlets 16 and 18 are provided which lead to mixing channels whose configuration is explained below based on FIG. 2.

(13) The mixing channels guide respective partial flows of materials from the storage chambers 12 and 14 toward each other and end in pre-mixing zones which can also be seen from FIG. 2. Starting from the pre-mixing zones, partial flows are supplied to the mixing zone. A part of the mixing zone is covered by an impact element 20 which can be seen in FIG. 1. In this way, the materials that have now been mixed are deflected into the dispensing direction of the syringe, that is to say in the direction of an axis 22 of a cannula channel 24 which is configured in a cannula 26.

(14) On the inlet side of the cannula channel 24 a deflection zone 30 is configured which is opposite to the impact element 20. The deflection zone 30 comprises inclined surfaces 32 which surround the impact element 20 in their basic configuration and which are configured consensually with its inclined surfaces as well as baffles 34 which extend between the inclined surfaces 32 and the inlet of the cannula channel 24 and whose surface normal extends parallel to the axis 22.

(15) The mixing channels, the pre-mixing zone, the mixing zone including the impact element 20 and the deflection zone 30 together form an inventive mixing device 36.

(16) The cannula 26 is fitted or screwed onto the rest of the syringe 10 in a way known per se. In the exemplary embodiment illustrated, an insert element 40 pointing to the dispensing direction fits closely to its inside in which a major part of the mixing device 36 is configured.

(17) The insert device 40 also comprises a guide recess 42 which receives a guide element for driving pistons of the storage chambers 12 and 14 jointly.

(18) Upon actuation of a control button (not illustrated) which extends on the side of the syringe a drive element is actuated by means of push rods which extend to one another at an angle of 45 and which face toward each other, which drive element engages a gear rack and is used to move the pistons.

(19) The front end 50 of the cannula channel 24 comprises a recess for receiving a small cannula tube 52. The small cannula tube can also be seen from FIG. 5 in an exemplary embodiment, and is preferably mounted rotatably in the cannula channel 24. In the embodiment according to FIG. 1 it is mounted rotatably in the cannula channel but not slidably in the direction of the axis 22, while it is mounted slidably in the embodiment according to FIG. 5. It is to be understood that the embodiments of FIGS. 1 and 5as far as they differ from one anothercan be combined with each other, respectively, which means that, for instance, a slidable mounting can also be provided in the embodiment according to FIG. 1.

(20) FIG. 2 illustrates how the individual parts of the mixing device 36 can be realized in the insert element 40. Subsequent to the outlets 16 and 18 the mixing channels 54, 56, 58 and 60 extend, respectively. In this connection, the mixing channels 54 and 56 on the one hand and 58 and 60 on the other hand diverge from each other, respectively, for instance at an angle of between 20 and 70, preferably at an angle of between 40 and 50, for instance at an angle of 45. They are symmetrical to one another such that all mixing channels 54 to 60 form a diamond shape, when considered jointly.

(21) The mixing channels 54 to 60 each terminate in pre-mixing zones. In this connection, the mixing channels 54 and 58 terminate in the pre-mixing zone 62 and the mixing channels 56 and 60 in the pre-mixing zone 64. Each pre-mixing zone comprises fillets 68 and 70 toward the outside, respectively, that is to say at the side faces which are opposite to one another. The outlets 74 and 76 of the pre-mixing zones 62 and 64 point toward each other and lead to the mixing zone 80.

(22) The mixing zone 80 comprises the impact element 20 as a central element. The impact element 20 is configured either in the style of a flat pyramid or as a cone, or possibly as a truncated cone. Alternatively, it can be configured in the shape of a segment of a sphere or paraboloid. Across the impact element 20 the partial flows from the outlets 74 and 76 of the pre-mixing zones 62 and 64 collide with each other and are correspondingly post-mixed in the mixing zone 80.

(23) As can be seen from FIG. 3 the impact element 20 comprises a relatively large nose angle. Anyway, the nose angle is an obtuse angle and, for instance, amounts to between 110 and 160, preferably to about 135.

(24) It can be seen that the impact element 20 is configured completely in the insert element 40.

(25) It can be seen from FIG. 4 how the partial flows 100 in the mixing channels 54 to 60 diverge at first, starting from the outlets 16 and 18, and then collide with each other respectively in the pre-mixing zones 62 and 64 and are deflected thereat.

(26) Above the impact element 20 there is a further collision of the partial flows 102 and 104 into the third dimension, that is to say out of the drawing plane in FIG. 4. This double deflection in two dimensions also leads to the materials being mixed well.

(27) FIG. 5 shows a modified embodiment of the inventive syringe. In the rearward area of the cannula there is a gap 110 having a thickness of, for instance, 10 m between the cannula 26 and the insert element 40 which absorbs temperature-related movements of the individual parts of the syringe. Because of the shared entrance at the inlet of the cannula channel 24 the inventively intermixed material is squeezed out jointly.

(28) In the front area of the cannula channel 24 the small cannula tube 52 is guided in a slidably movable and rotatably movable manner. For this purpose, the cannula channel 24 is configured as a tube which is inserted into the cannula 26. Then, the small cannula tube 52 is guided on this tube 24. A compression spring 120 which is biased between the cannula 26 and a rearward thickened portion 122 of the small cannula tube 52 is received such that it surrounds the front area of the cannula channel 24. The movement of the small cannula tube 52 toward the front is limited by a stop 124 which acts against the thickened portion 122. Furthermore, on the outlet side the small cannula tube 52 is guided by a relatively narrow through-recess 126 of the cannula 26 such that a good lateral stabilization is possible due to the guidance which is spaced apart.

(29) As the small cannula tube can be rotated the syringe is particularly easy to handle even if it is actuated from the side, for instance, by means of a control button. In that case, the control button can remain at the same position, independent of whether the dentist treats the upper jaw or the lower jaw.

(30) In an advantageous embodiment a cannula tube 24 is fixedly attached in the cannula 26, for instance by adhesive bonding, pressing and injection-molding or by welding. In this embodiment the cannula is pushed onto the small cannula tube 52 in a rotatable manner.

(31) In a further modified embodiment the small cannula tube is configured of a flexible material which is preferably non-elastic and limp such that it remains at a certain position after it has been bent into a specific direction without resiling.

(32) In the exemplary embodiment illustrated the small cannula tube 52 is provided with an offset 128 on the end side. It is to be understood that the offset can be configured in a more extreme or less extreme manner than illustrated in FIG. 5. If the offset is small, it is possible to squeeze out dental material similar to a pushing tip by head-on pressure to the small cannula tube 52. The dental material has already been mixed perfectly when it is in the small cannula tube 52 such that the low flow resistance which occurs at the start and the end of the insertion of the small cannula tube does not have any unfavorable effect on the mixing process.

(33) In FIG. 6, dosing device 100 is shown in the storage chambers 12 and 14. FIG. 7A shows flow areas of the mixing channels 54 and 56 at line C-C of FIG. 2 FIG. 7B shows flow areas of the mixing channels 54 and 56 at line D-D of FIG. 2 These flow areas for the dental materials comprise a substantially constant cross-sectional area starting from the storage chamber (12 and 14) to the mixing zone (80) and are configured free from discontinuities and wake spaces.