METHOD FOR MAKING A CUP UNIT OF A LIPSTICK CONTAINER

Description

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a lipstick and, more particularly, to method for making a cup unit of a lipstick container.

2. Related Prior Art

Referring to FIGS. 5 and 6, a conventional lipstick container 80 includes cylinders 81, 82 and 86 and a cup 84. The cylinder 82 includes a helical slit 83. The cylinder 86 includes a rectilinear slit 87. The cup 84 includes a boss 85 on an external side. The cylinder 82 is fitted in the cylinder 81 so that they are rotatable together with each other. The cylinder 86 is inserted in the cylinder 82 so that a portion of the rectilinear slit 87 is in communication with a portion of the helical slit 83. The cup 84 is inserted in the cylinder 86 so that the boss 85 is inserted in the section of the rectilinear slit 87 and the portion of the helical slit 83. A lipstick (not shown) includes a lower portion inserted in the cup 84. By rotating the cylinders 81 and 82 relative to the cylinder 86, the cup 84 is moved up and down relative to the cylinder 86 so that an upper portion of the lipstick is moved out of or into the cylinder 86.

In early days, the cup 84 is made of a plastic material such as PV and PC by injection molding. Thus, the boss 85 is solid and made in one piece with the cup 84. Such plastic cups can be found in Chinese Patent No. 107232736 or Taiwanese Patent No. I707643.

Now, such cups are made of metal such as aluminum for environmental protection. Such metal cups can be found in Chinese Patent No. 110801095. In such a case, the boss 85 is made on the external side of the cup 84 by punching an internal side of the cup 84. However, the boss 85 often does not extend long enough from the external side of the cup 84. Hence, the boss 85 does not extend adequately deep into the helical slit 83. As a result, the lipstick container 80 does not work properly.

The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.

SUMMARY OF INVENTION

It is the primary objective of the present invention to provide a method for making a reliable and effective cup unit of a lipstick container.

To achieve the foregoing objective, the method includes the step of providing a cup with a chamber, a wall extending around the chamber, and an aperture extending throughout the wall so that the aperture is in communication with the chamber. A rivet is provided with a head and a slender portion. The slender portion includes a first end connected to the head and a second end located opposite to the first end. The second end of the slender portion is enlarged so that the enlarged second end of the slender portion is tightly located against an internal side of the wall and that the head is tightly located against an external side of the wall. The head is insertable in helical slit of a cylinder of the lipstick container and a rectilinear slit of another cylinder of the lips stick container.

Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of the preferred embodiment referring to the drawings wherein:

FIG. 1 is a flow chart of a method for making a cup unit of a lipstick container according to the preferred embodiment of the present invention;

FIG. 2 is an exploded view of the cup unit at a first step of the method shown in FIG. 1;

FIG. 3 is a cross-sectional view of the cup unit at a second step of the method shown in FIG. 1;

FIG. 4 is a perspective view of the cup unit finished by the method shown in FIG. 1;

FIG. 5 is an exploded view of a conventional lipstick container; and

FIG. 6 is a perspective view of the lipstick container shown in FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIG. 1, there is a method for making a cup unit of a lipstick container according to the preferred embodiment of the present invention. The lipstick container is identical to the conventional lipstick container 80 described referring to FIGS. 5 and 6 except for including a cup unit (FIGS. 2 through 4) instead of the cup 84.

Referring to FIGS. 1 and 2, at 10, a cup 20 and a rivet 25 are provided. Both the cup 20 and the rivet 25 are made of metal such as aluminum.

The cup 20 is made with a wall 21 extending around a chamber 22. The wall 21 is made with an aperture 23 by drilling or punching for example. The aperture 23 is in communication with the chamber 22.

The rivet 25 is made with a head 24 at an end of a slender portion 26. Preferably, the head 24 is a solid portion. Preferably, the slender portion 26 is a tubular portion or at least a free end of the slender portion 26 located opposite to the head 24 is made tubular, i.e., made with a bore (not numbered) in it. A diameter of the head 24 is larger than a diameter of the slender portion 26. The diameter of the slender portion 26 is marginally smaller than a diameter of the aperture 23.

At 12, the slender portion 26 is inserted into the chamber 22 through the aperture 23. A free end (not numbered) of the slender portion 26 is located in the chamber 22. The head 24 is located on an external side of the wall 21.

Referring to FIGS. 1 and 3, at 14, the free end of the slender portion 26 is enlarged by a tool 30 so that the enlarged free end of the slender portion 26 is tightly located against an internal side of the wall 21 and the head 24 is tightly located against the external side of the wall 21.

The tool 30 can be driven manually, electrically, pneumatically, hydraulically or in any other manner. The tool 30 can be an impact riveter or a PLC robot. Preferably, the tool 30 includes a punching element 31 and a mold 32. The mold 32 receives the free end of the slender portion 26. The punching element 31 punches the head 24 to squeeze the free end of the slender portion into the mold 32. Thus, free end of the slender portion 26 is enlarged.

Referring to FIG. 4, the head 24 is located on the external side of the wall 21. Hence, the head 24 can be used as a boss inserted in the helical slit 83 and the rectilinear slit 87 described referring to FIGS. 5 and 6. The head 24 can be made with adequate thickness (or length) so that it is effectively insertable in the helical slit 83. Accordingly, the operation of the lipstick container is reliable.

The present invention has been described via the illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.