Method for Making a Cup Unit of a Lipstick Container

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

Referring to, a conventional lipstick containerincludes cylinders,andand a cup. The cylinderincludes a helical slit. The cylinderincludes a rectilinear slit. The cupincludes a bosson an external side. The cylinderis fitted in the cylinderso that they are rotatable together with each other. The cylinderis inserted in the cylinderso that a portion of the rectilinear slitis in communication with a portion of the helical slit. The cupis inserted in the cylinderso that the bossis inserted in the section of the rectilinear slitand the portion of the helical slit. A lipstick (not shown) includes a lower portion inserted in the cup. By rotating the cylindersandrelative to the cylinder, the cupis moved up and down relative to the cylinderso that an upper portion of the lipstick is moved out of or into the cylinder.

In early days, the cupis made of a plastic material such as PV and PC by injection molding. Thus, the bossis solid and made in one piece with the cup. 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 bossis made on the external side of the cupby punching an internal side of the cup. However, the bossoften does not extend long enough from the external side of the cup. Hence, the bossdoes not extend adequately deep into the helical slit. As a result, the lipstick containerdoes not work properly.

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

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.

Referring to, 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 containerdescribed referring toexcept for including a cup unit () instead of the cup.

Referring to, at, a cupand a rivetare provided. Both the cupand the rivetare made of metal such as aluminum.

The cupis made with a wallextending around a chamber. The wallis made with an apertureby drilling or punching for example. The apertureis in communication with the chamber.

The rivetis made with a headat an end of a slender portion. Preferably, the headis a solid portion. Preferably, the slender portionis a tubular portion or at least a free end of the slender portionlocated opposite to the headis made tubular, i.e., made with a bore (not numbered) in it. A diameter of the headis larger than a diameter of the slender portion. The diameter of the slender portionis marginally smaller than a diameter of the aperture.

At, the slender portionis inserted into the chamberthrough the aperture. A free end (not numbered) of the slender portionis located in the chamber. The headis located on an external side of the wall.

Referring to, at, the free end of the slender portionis enlarged by a toolso that the enlarged free end of the slender portionis tightly located against an internal side of the walland the headis tightly located against the external side of the wall.

The toolcan be driven manually, electrically, pneumatically, hydraulically or in any other manner. The toolcan be an impact riveter or a PLC robot. Preferably, the toolincludes a punching elementand a mold. The moldreceives the free end of the slender portion. The punching elementpunches the headto squeeze the free end of the slender portion into the mold. Thus, free end of the slender portionis enlarged.

Referring to, the headis located on the external side of the wall. Hence, the headcan be used as a boss inserted in the helical slitand the rectilinear slitdescribed referring to. The headcan be made with adequate thickness (or length) so that it is effectively insertable in the helical slit. 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.