Central core assembly and cosmetic container comprising such a central core assembly

Abstract

The invention relates to a central core assembly and a cosmetic product container comprising said central core assembly. The central core assembly comprises a central core (10), a screw tube (20), a guide piece (30), an elastic piece (40), and a nut (50). The central core and the guide piece are fixed together, the screw tube is screwed to the nut, the elastic piece is circumferentially fixed to the nut, the guide piece has a first gear tooth (32), the elastic piece has a second gear tooth (42), and at least one of the first and second gear teeth comprises a lower surface, a first inclined surface, and a second inclined surface, the angle between the first inclined surface and the lower surface being α1, and the angle between the second inclined surface and the lower surface being α2, α1 and α2 being different acute angles. (Figure for the abbreviation: Fig. 1)

Description

Title of the invention: Central core assembly and cosmetic container comprising such a central core assembly Technical field

[0001] The present invention relates to the technical field of cosmetic packaging, and more particularly to a cosmetic container for a central core assembly and a cosmetic container comprising the central core assembly. Prior art

[0002] Currently, cosmetic products have become an essential part of people's daily lives. In order to facilitate transportation and use, cosmetic products are packaged using specific containers before leaving the factory. In order to meet the varied packaging needs for different types of cosmetic products, cosmetic containers come in various shapes such as boxes, tubes, and pouches. The central core, also called the central tube, is the main component of tube-shaped containers. It is composed of the central tube itself, the piston, the screw, and the nut. When the nut is turned, it causes the screw and the piston to reciprocate inside the central tube. Known central tubes can be rotated in both directions, making the user experience uniform and unattractive. Presentation of the invention

[0003] In order to overcome the above-mentioned drawbacks, the present invention provides a central core assembly comprising a first gear tooth and a second gear tooth in mutual engagement. During use, the cooperation between the first gear tooth and the second gear tooth makes it possible to generate different resistance during clockwise and counterclockwise rotations, thereby improving the feel of use of the product and raising its quality level.

[0004] According to one aspect of the invention, a central core assembly comprises a central core, a screw tube, a guide piece, an elastic piece and a nut. The central core and the guide piece are fixed together, the screw tube is screwed to the nut, the elastic piece is circumferentially fixed on the nut. The guide piece comprises a first gear tooth, the elastic piece comprises a second gear tooth in mutual engagement with the first gear tooth. At least one of the gear teeth, the first gear tooth or the second gear tooth, comprises a bottom surface, a first inclined surface and a second inclined surface. The angle between the first inclined surface and the bottom surface is a1, and the angle between the second inclined surface and the bottom surface is a2. angles al and a2 are both acute angles and al is not equal to a2.

[0005] In one embodiment, the structure of the first gear tooth and the second gear tooth is identical, the upper surfaces of the first inclined surface and the second inclined surface are planar or curved, and a1 < a2.

[0006] In one embodiment, when the first gear tooth and the second gear tooth are in mutual engagement, the first inclined surface of the first gear tooth is in contact with the first inclined surface of the second gear tooth, and the second inclined surface of the first gear tooth is in contact with the second inclined surface of the second gear tooth. When the cosmetic material is screwed, the first inclined surface of the second gear tooth slides along the first inclined surface of the first gear tooth and gradually separates, or when the cosmetic material is screwed, the second inclined surface of the second gear tooth slides along the second inclined surface of the first gear tooth and gradually separates.

[0007] In one embodiment, the first gear tooth is uniformly and continuously arranged along the circumference of the guide piece, and the second gear tooth is uniformly and spaced apart along the circumference of the elastic piece.

[0008] In one embodiment, the number of first gear teeth is N times the number of second gear teeth, or the number of second gear teeth is N times the number of first gear teeth, where N is an integer from 1 to 10.

[0009] In one embodiment, the number of first gear teeth is 6 and the number of second gear teeth is 3, or the number of first gear teeth is 3 and the number of second gear teeth is 6.

[0010] In one embodiment, the screw tube comprises an attached screw and a piston, the screw and piston being a single molded part, or the screw and piston are of separate structure.

[0011] In one embodiment, the first gear tooth is disposed on the inner wall of the guide piece, or the guide piece comprises a gear tooth ring, the first gear tooth being disposed on the lower surface of the gear tooth ring, the gear tooth ring being secured to the inner wall of the guide piece by projecting ribs.

[0012] In one embodiment, the resilient part comprises a retaining ring and a spring, the second gear tooth being disposed on the upper surface of the retaining ring, the retaining ring being circumferentially secured to the nut by projecting ribs, the retaining ring and the spring being one piece in integrally molded plastic, or the retaining ring and spring are of separate structure, the spring being mounted on the nut.

[0013] The present invention also relates to a cosmetic product container comprising said central core assembly, a lid assembly and a bottom assembly. The central core assembly is mounted inside the bottom assembly, and the bottom assembly can drive the rotation of the nut. The lid assembly can be inserted and fixed on the bottom assembly in a removably manner.

[0014] The invention has the following advantageous effects.

[0015] The advantages of the present application are as follows: the central core assembly of the present application comprises a central core, a screw tube, a guide piece, an elastic piece and a nut. The central core and the guide piece are fixed together, the screw tube is screwed to the nut, the elastic piece is circumferentially fixed to the nut, the guide piece has a first gear tooth, the elastic piece has a second gear tooth which mutually engages with the first gear tooth, the first gear tooth and the second gear tooth have first and second inclined planes respectively.Thus, the nut can be rotated clockwise and counterclockwise, and the slopes of the first and second inclined planes are different, resulting in different resistance when rotating the nut clockwise and counterclockwise, so as to meet different customer needs. The central core assembly of the present invention has few components and a simple structure, which reduces the manufacturing cost and the difficulty of assembling the product. By mutually cooperating with the first gear tooth on the guide piece and the second gear tooth on the elastic piece, a smooth rebound feeling can be produced during use, which facilitates operation and control.In addition, different resistances can be generated when rotating and retracting cosmetic materials, thus improving the feeling of using the product and increasing its quality. Brief description of the drawings

[0016] [Fig.l] illustrates an exploded view of the central core assembly in Embodiment 1 of the present invention.

[0017] [Fig.2] illustrates a structural diagram of the screw tube in Embodiment 1 of the present invention.

[0018] [Fig.3] illustrates a structural diagram of the elastic part in embodiment 1 of the present invention.

[0019] [Fig.4] illustrates an exploded view of the central core assembly in the mode of embodiment 2 of the present invention.

[0020] [Fig.5] illustrates a structural diagram of the gear tooth ring in Embodiment 2 of the present invention.

[0021] [Fig.6] illustrates a structural diagram of the retaining ring in Embodiment 2 of the present invention.

[0022] [Fig.7] illustrates an exploded view of the screw tube in embodiment 2 of the present invention.

[0023] [Fig.8] illustrates a structural diagram of the metal spring in Embodiment 2 of the present invention.

[0024] [Fig.9] illustrates a structural diagram of the plastic spring in Embodiment 2 of the present invention.

[0025] [Fig. 10] illustrates a structural diagram of the central core assembly in Embodiment 2 of the present invention.

[0026] [Fig. 11] illustrates an exploded diagram of the central core assembly in Embodiment 3 of the present invention.

[0027] [Fig. 12] illustrates one of the structural diagrams of the central core assembly in Embodiment 3 of the present invention.

[0028] [Fig. 13] illustrates another structural diagram of the central core assembly in Embodiment 3 of the present invention.

[0029] [Fig. 14] illustrates one of the process diagrams of the central core assembly in Embodiment 3 of the present invention.

[0030] [Fig. 15] illustrates another process diagram of the central core assembly in Embodiment 3 of the present invention.

[0031] [Fig. 16] illustrates a structural diagram of the makeup container in Embodiment 2 of the present invention.

[0032] [Fig. 17] illustrates an exploded diagram of the makeup container in Embodiment 2 of the present invention.

[0033] [Fig. 18] illustrates one of the usage state diagrams of the makeup container in Embodiment 2 of the present invention.

[0034] [Fig. 19] illustrates another use state diagram of the makeup container in Embodiment 2 of the present invention.

[0035] [Fig.20] illustrates another use state diagram of the makeup container in Embodiment 2 of the present invention.

[0036] Reference signs:

[0037] 10 - a central core itself

[0038] 20 - a screw tube

[0039] 21 - a screw

[0040] 22 - a piston

[0041] 30 - a guide piece

[0042] 31 - a gear tooth ring

[0043] 32 - the first gear tooth

[0044] 33 - the first inclined plane

[0045] 34 - the second inclined plane

[0046] 40 - an elastic piece

[0047] 41 - a retaining ring

[0048] 42 - the second gear tooth

[0049] 43 - a spring

[0050] 50 - a nut

[0051] 60 - a cover assembly

[0052] 61 - an outer cover

[0053] 62 - an inner cover

[0054] 63 - the first suspended mass

[0055] 70 - a background assembly

[0056] 71 - an external background

[0057] 72 - an interior background

[0058] 73 - the second suspended mass

[0059] 74 - an outer intermediate ring

[0060] 75 - an inner intermediate ring

[0061] 76 - cosmetic materials Detailed description of the embodiments

[0062] The technical solutions of the embodiments of the present application will be clearly and completely described below in connection with the embodiments of the present application. Of course, the described embodiments are only a part of the embodiments of the present application, and not their entirety. Based on the embodiments of the present application, all other embodiments obtained without creative work by a person of ordinary skill in the art fall within the scope of protection of the present application.

[0063] It is to be noted that the terms "first", "second", etc. in the description and claims of the present application and in the aforementioned accompanying drawings are used to distinguish like subject matter and are not to be used to describe a particular order or sequence. It is to be understood that the data so used may, where appropriate, be interchanged so that the embodiments of the present application described herein may be implemented, for example, in an order other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", and any variation thereof, are intended to cover a non-exclusive inclusion, for example, a process, a method, a system, a product or apparatus comprising a series of steps or units shall not be limited to those steps or units, but may include other steps or units not explicitly listed or inherent in those processes, methods, products or equipment.

[0064] For ease of description, spatially related terms such as "above......", "over......", "on the upper surface of......", "above", etc., to describe the spatial location of a device or feature relative to other devices or features, as shown in the figure, the spatial location relative to other devices or features. It is understood that the term "relative in space" is intended to encompass different orientations in use or operation other than the orientation of the device shown in the drawings. For example, if the device is inverted in the accompanying drawings, a device described as being "above" or "on" other devices or configurations will later be positioned as being "below" or "on top" other devices or configurations, "or "beneath other devices or structures". Thus, the exemplary phrase "above......" may include "above......" and "below......". The device may also be positioned in other different ways (rotated 90 degrees or other orientations) and the relative spatial descriptions used herein are explained accordingly.

[0065] As illustrated in [Fig.l]-20, the invention relates to a central core assembly comprising a central core 10, a screw tube 20, a guide piece 30, an elastic piece 40 and a nut 50. The central core 10 is fixed to the guide piece 30, the screw tube 20 is screwed to the nut 50, and the elastic piece 40 is circumferentially fixed to the nut 50. The guide piece 30 comprises a first gear tooth 32, and the elastic piece 40 comprises a second gear tooth 42 which mutually engages with the first gear tooth 32. At least one of the gear teeth 32, 42 comprises a base surface, a first inclined surface 33 and a second inclined surface 34. The angle between the first inclined surface 33 and the base surface is al, and the angle between the second inclined surface 34 and the base surface is a2. Angles a1 and a2 are both acute angles and are not equal.In the present invention, the screw tube 20 and the nut 50 are screwed into each other by a thread. The screw tube 20 is located inside the nut 50, and the guide piece 30 and the center core 10 are arranged outside the screw tube 20 and the nut 50. The nut 50 extends through the guide piece 30 and, when rotated, can cause the screw tube 20 to move vertically along the center core 10, thereby squeezing out or retracting the cosmetic materials inside the screw tube 20. The elastic piece 40 is arranged on the outer wall of the nut 50 circumferentially, and it can rotate synchronously with the nut 50 when rotated. As shown in Figures 1 and 3, the inner wall of the elastic piece 40 is . provided with projecting ribs, while the outer wall of the nut 50 is provided with grooves. When the elastic part 40 is mounted on the nut 50, the ribs fit snugly into the grooves, thus ensuring circumferential attachment of the elastic part 40 to the nut 50 while allowing axial movement. Of course, other circumferential attachment means can also be used, for example, mutually snap-fit ​​ribs on the elastic part and the nut. During assembly, as illustrated in Figures 14 and 15, the first gear tooth 32 of the guide part 30 engages with the second gear tooth 42 on the elastic part 40.When in use, a noise occurs when the second gear tooth 42 exceeds the first gear tooth 32, which allows the user to determine the rotation angle and more precisely control the use process of the product, thereby improving the user's comfort.

[0066] The expression "at least one of the gear teeth 32, 42 comprises a base surface, a first inclined surface 33 and a second inclined surface 34" means that there are three possible situations: first, the first gear tooth 32 comprises a base surface, a first inclined surface 33 and a second inclined surface 34, and the structure of the second gear tooth 42 is not specified; second, the second gear tooth 42 comprises a base surface, a first inclined surface 33 and a second inclined surface 34, and the structure of the first gear tooth 32 is not specified; third, both the first gear tooth 32 and the second gear tooth 42 comprise a base surface, a first inclined surface 33 and a second inclined surface 34.

[0067] As illustrated in Figures 3 and 6, take the second gear tooth 42 as an example. The second gear tooth 42 is a boss that rises in the axial direction from the upper surface of the elastic piece 40. The lower surface of the second gear tooth 42 corresponds to the upper surface of the elastic piece 40 where it is located. The first inclined surface 33 and the second inclined surface 34 are two slopes. The angle between the first inclined surface 33 and the base surface is determined by the central axis of the first inclined surface 33 and the central axis of the base surface, while the angle between the second inclined surface 34 and the base surface is determined by the central axis of the second inclined surface 34 and the central axis of the base surface.Angles a1 and a2 are both acute angles, meaning that both the first inclined surface and the second inclined surface are gentle slopes, thus ensuring that nut 50 can rotate both clockwise and counterclockwise. The fact that a1 and a2 are not equal, i.e., a1 > a2 or a1 < a2, ensures that the slope of the first inclined surface is different from that of the second inclined surface, resulting in . different resistance when rotating the nut clockwise and counterclockwise, meeting different customer requirements.

[0068] The structure of the first gear tooth 32 and that of the second gear tooth 42 may be different. For example, the first gear tooth 32 comprises a bottom surface, a first inclined surface 33 and a second inclined surface 34, while the second gear tooth 42 is an ordinary hump structure, and vice versa. Optionally, as illustrated in Figures 14 and 15, the structure of the first gear tooth 32 and the second gear tooth 42 is the same, the top surfaces of the first inclined surface 33 and the second inclined surface 34 are planar or curved, a1 < a2.In this embodiment, the meaning of "the upper surfaces of the first inclined surface 33 and the second inclined surface 34 are planar or curved" is as follows: the upper surfaces of the first inclined surface 33 and the second inclined surface 34 are planar, or the upper surfaces of the first inclined surface 33 and the second inclined surface 34 are curved, the curve may be convex or concave; or the upper surface of the first inclined surface 33 is planar, the upper surface of the second inclined surface 34 is curved; or the upper surface of the first inclined surface 33 is curved, the upper surface of the second inclined surface 34 is planar, a1 < a2 means that the slope of the first inclined surface 33 is gentler than the slope of the second inclined surface 34.This definition of al < a2 is used to clearly explain the working process of the central core assembly and is not a structural limitation. In another embodiment, al can also be greater than a2.

[0069] As illustrated in Figures 14 and 15, when the first gear tooth 32 and the second gear tooth 42 engage with each other, the first inclined surface of the first gear tooth 32 fits against the first inclined surface of the second gear tooth 42, and the second inclined surface of the first gear tooth 32 fits against the second inclined surface of the second gear tooth 42. As illustrated in [Fig. 14], in one embodiment, when the nut 50 is rotated counterclockwise, the cosmetic materials are pushed outward while the elastic piece 40 also rotates counterclockwise. The second inclined surface of the second gear tooth 42 slides along the first inclined surface of the first gear tooth 32 and gradually separates therefrom.In other words, the second gear tooth 42 passes over the first gear tooth 32 along the first inclined surface and because of the gentler slope of the first inclined surface 33, less torque is required to force out the cosmetic materials. When the second tooth . gear 42 passes over a first gear tooth 32, the elastic piece 40 recovers, thereby bringing the second gear tooth 42 back into contact with the first gear tooth 32. In contrast, when the nut 50 is turned clockwise, the cosmetic materials are retracted inside the central core 10, and the second gear tooth 42 passes over the first gear tooth 32 along the second inclined surface, due to the steeper slope of the second inclined surface 34, more torque is required to retract the cosmetic materials.

[0070] In another embodiment, as illustrated in [Fig. 15], when the nut 50 is turned counterclockwise, the second inclined surface of the second gear tooth 42 slides along the second inclined surface of the first gear tooth 32 and gradually separates therefrom. In other words, the second gear tooth 42 passes over the first gear tooth 32 along the second inclined surface, because of the steeper slope of the second inclined surface 34, more torque is required to force out the cosmetic materials.In contrast, when the nut 50 is turned clockwise, the cosmetic materials are retracted inside the central core 10, and the second gear tooth 42 passes over the first gear tooth 32 along the first inclined surface, due to the gentler slope of the first inclined surface 33, less torque is required to retract the cosmetic materials.

[0071] As illustrated in Figures 3 to 5, the first gear tooth 32 is arranged uniformly and continuously along the circumference of the guide piece 30, while the second gear tooth 42 is arranged uniformly and spaced apart along the circumference of the elastic piece 40. The uniform and continuous arrangement of the first gear tooth 32 along the circumference of the guide piece 30 means that adjacent teeth of the first gear tooth 32 are connected to each other and all teeth of the first gear tooth are of the same size. The uniform and spaced arrangement of the second gear tooth 42 along the axis of the elastic piece 40 means that adjacent teeth of the second gear tooth 42 have an equal spacing distance and all teeth of the second gear tooth are of the same size.During use, the elastic part 40 is regarded as a moving part and the guide part 30 as a fixed part. By distributing a smaller number of gear teeth on the elastic part and a larger number of gear teeth on the guide part, the operating stability of the central core assembly can be ensured.

[0072] The number of first gear teeth 32 is N times the number of second gear teeth 42 where N is an integer from 1 to 10. Optionally, the number of first gear teeth 32 is twice the number of second gear teeth 42, or the number of second gear teeth 42 is twice the number of first gear teeth 32. Optionally, as shown in Figures 3 to 5, the number of first gear teeth 32 is 6 and the number of second gear teeth 42 is 3, or the number of first gear teeth 32 is 3 and the number of second gear teeth 42 is 6. Such a distribution of gear teeth can ensure the stability of the center core assembly during rotation, while allowing the center core to rebound smoothly during rotation, thereby facilitating operation and control.

[0073] As illustrated in Figures 1 and 2, in Embodiment 1, the screw tube 20 comprises a screw 21 and a piston 22 fixedly connected. The screw 21 and the piston 22 are formed as a single piece, thereby saving a set of molds and reducing the production costs of the product. In Embodiment 2, as illustrated in Figures 4 and 7, the screw 21 and the piston 22 are of separate structure. As illustrated in [Fig. 4], by separating the screw and the piston, the screw 21 can be manufactured using a harder first material to meet the overall strength requirements of the screw 21, while the piston 22 can be manufactured using a softer second material to meet the sealing requirements of the piston and the temperature requirements when filling products such as lipstick, lip balm, lip gloss, etc. As illustrated in [Fig.7], depending on requirements, the screw 21 and the piston 22 can also be made of plastic material.

[0074] As illustrated in [Fig.l], in Embodiment 1, the first gear tooth 32 is arranged on the inner wall of the guide piece 30, that is, it is formed directly on the inner wall of the guide piece 30, which reduces the production costs of the product, reduces the number of parts, and simplifies the installation process. In Embodiment 2, as illustrated in Figures 4 and 5, the guide piece 30 comprises a gear tooth ring 31, and the first gear tooth 32 is arranged on the underside of the gear tooth ring 31, which is fixed to the inner wall of the guide piece 30 by projecting ribs. In this embodiment, the gear tooth ring 31 is an independent part, which facilitates the formation of the first gear tooth 32 of an irregular shape.

[0075] As illustrated in Figures 1 and 3, in Embodiment 1, the elastic part 40 comprises a retaining ring 41 and a spring 43. The second gear tooth 42 is arranged on the upper face of the retaining ring 41, which is circumferentially fixed on the nut 50 by projecting ribs. The retaining ring 41 and the spring 43 are integrally molded plastic parts, i.e., the elastic part 40 is an integrally molded plastic part. This not only saves a set of molds and reduces production costs, but also makes all plastic products, such as the screw tube 20, the guide piece 30, the elastic piece 40 and the nut 50, made of polybutylene terephthalate (PBT), which facilitates product recycling. In embodiment 2, as shown in Figures 4 and 6-9, the retaining ring 41 and the spring 43 are of separate structure, with the spring 43 being mounted on the nut 50. In this case, as shown in [Fig. 8], the spring 43 may be a traditional metal spring, and the central core 10 may be made of aluminum, which reduces the production costs of the product. Alternatively, as shown in [Fig. 9], the spring 43 may also be a plastic part to facilitate product recycling.

[0076] It should be noted that the screw tube 20 may be a single piece or a separate structure, the guide piece 30 may be a single piece or a separate structure, and the elastic piece 40 may be a single piece or a separate structure. The six different component structures may be interchangeably combined. In Embodiment 1, as shown in [Fig. 1], the screw tube 20, the guide piece 30, and the elastic piece 40 are a single piece. In Embodiment 2, as shown in [Fig. 4], the screw tube 20, the guide piece 30, and the elastic piece 40 are a separate structure. In Embodiment 3, as shown in Figures 11-13, the screw tube 20 and the guide piece 30 are a single piece, while the elastic piece 40 is a separate structure. Of course, other combinations are possible, but not all of them are described here.

[0077] As illustrated in Figures 16-20, a cosmetic container includes a central core assembly, a lid assembly 60, and a bottom assembly 70. The central core assembly is installed inside the bottom assembly 70, and the bottom assembly 70 can drive the rotation of the nut 50. The lid assembly 60 can be inserted and removably secured to the bottom assembly 70. The lid assembly 60 includes an outer lid 61 and an inner lid 62 secured inside the outer lid 61. Between the outer lid 61 and the inner lid 62 is a first suspended mass 63. The bottom assembly 70 includes an outer bottom 71, an inner bottom 72, a second suspended mass 73, an outer intermediate ring 74, and an inner intermediate ring 75.The inner bottom 72 is fixed inside the outer bottom 71, the second suspended mass 73 is installed in the nut 50, the nut 50 is circumferentially fixed to the inner bottom 72 by protruding ribs, and the inner intermediate ring 75 is fixed inside the outer intermediate ring 74. The outer intermediate ring 74 is installed between the outer bottom 71 and the inner bottom 72, and the inner intermediate ring 75 is fixedly fitted into the central core 10. When in use, the user removes the cover assembly 60, as shown in the . [Fig. 19]. At this time, the cosmetic material 76 such as lipstick, lip balm, lip gloss, etc., is completely retracted inside the center core 10. By rotating the bottom assembly 70, the bottom assembly 70 drives the rotation of the nut 50, which in turn advances the cosmetic material 76 inside the plunger 22 for use by the user, as shown in [Fig. 20]. At this time, the cosmetic material 76 is completely out of the center core 10. The user can rotate the cosmetic material to different heights according to his needs.

[0078] It should be noted that for a person skilled in the art, there are several variations and improvements which can be made without departing from the concept of the present application, but which fall within the scope of protection of the present application. Therefore, the scope of protection of this application is defined by the appended claims.

Claims

Claims

1. A central core assembly, characterized in that it comprises a central core (10), a screw tube (20), a guide piece (30), an elastic piece (40) and a nut (50), the central core (10) and the guide piece (30) are fixed together, the screw tube (20) is screwed to the nut (50), the elastic piece (40) is circumferentially fixed on the nut (50), the guide piece (30) comprises a first gear tooth (32), the elastic piece (40) comprises a second gear tooth (42) which meshes with the first gear tooth (32), at least one of the gear teeth among the first gear tooth (32) and the second gear tooth (42) comprises a bottom surface, a first inclined surface (33) and a second inclined surface (34), the angle between the first inclined surface (33) and the lower surface is al, and the angle between the second inclined surface (34) and the lower surface is a2,angles al and a2 are both acute angles and al is not equal to a2.,

2. The central core assembly according to claim 1, characterized in that the structure of the first gear tooth (32) and the second gear tooth (42) is identical, the upper surface of the first inclined surface (33) and the second inclined surface (34) is flat or curved, and a1 < a2.

3. The central core assembly according to claim 2, characterized in that when the first gear tooth (32) meshes with the second gear tooth (42), the first inclined surface of the first gear tooth (32) is in contact with the first inclined surface of the second gear tooth (42), and the second inclined surface of the first gear tooth (32) is in contact with the second inclined surface of the second gear tooth (42), when the cosmetic material is screwed in, the first inclined surface of the second gear tooth (42) slides along the first inclined surface of the first gear tooth (32) and gradually separates, or when the cosmetic material is screwed in, the second inclined surface of the second gear tooth (42) slides along the second inclined surface of the first gear tooth (32) and gradually separates.

4. The central core assembly according to claim 1, characterized in that the first gear tooth (32) is arranged so uniform and continuous along the circumference of the guide piece (30), and the second gear tooth (42) is arranged uniformly and spaced along the circumference of the elastic piece (40).

5. The central core assembly according to claim 1, characterized in that the number of first gear teeth (32) is N times the number of second gear teeth (42), or the number of second gear teeth (42) is N times the number of first gear teeth (32), where N is an integer from 1 to 10.

6. The central core assembly according to claim 5, characterized in that the number of first gear teeth (32) is 6 and the number of second gear teeth (42) is 3, or the number of first gear teeth (32) is 3 and the number of second gear teeth (42) is 6.

7. The central core assembly according to any one of claims 1 to 6, characterized in that the screw tube (20) comprises a screw (21) and a piston (22), the screw (20) and the piston (22) being an integrally molded part, or the screw (21) and the piston (22) are separate structures.

8. The central core assembly according to any one of claims 1 to 6, characterized in that the first gear tooth (32) is arranged on the inner wall of the guide piece (30), or the guide piece (30) comprises a gear tooth ring (31), the first gear tooth (32) being arranged on the lower surface of the gear tooth ring (31), the gear tooth ring (31) being fixed to the inner wall of the guide piece (30) by projecting ribs.

9. The central core assembly according to claim 1, characterized in that the elastic part (40) comprises a retaining ring (41) and a spring (43), the second gear tooth (42) being arranged on the upper surface of the retaining ring (41), the retaining ring (41) being circumferentially fixed on the nut (50) by projecting ribs, the retaining ring (41) and the spring (43) being integrally molded plastic parts, or the retaining ring (41) and the spring (43) being separate structures, the spring (43) being mounted on the nut (50).

10. A container for cosmetic products, characterized in that it comprises a central core assembly as described in one of the claims- dications 1 to 9, a cover assembly (60) and a bottom assembly (70), the central core assembly is mounted inside the bottom assembly (70), and the bottom assembly (70) is capable of driving rotation of the nut (50), while the cover assembly (60) can be inserted and removed to seal onto the bottom assembly (70).