Coating implements with material supply – Solid material for rubbing contact or support therefor – Including means to advance material
Reexamination Certificate
2002-12-27
2003-10-07
Nguyen, Tuan N. (Department: 3751)
Coating implements with material supply
Solid material for rubbing contact or support therefor
Including means to advance material
C401S055000, C401S068000, C401S087000, C424S064000, C106S038200
Reexamination Certificate
active
06629797
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Patent Application No. 2002-53902, filed on Sep. 6, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a writing implement having a structure that advances and retreats a bar type lead element into or out of a container, and more particularly, it relates to a writing implement having a structure that enables simple manufacturing process and automation of the manufacturing line, the writing implement having a tip end of the lead element molded into a smooth and complete shape, and the writing implement having a bar type lead element rendering no waste during advance and retreat, and a molding method of the lead element therein.
2. Description of the Prior Art
Generally, a writing implement having a bar type lead element therein has a structure in which the lead element is movably disposed inside of a column type hollow container to be advanced and retreated. When in use, the lead element is advanced out of the container, and then retreated into the container after the writing is finished.
For the advance and retreat of the lead element, the conventional writing implement includes a lead element supporting means that is linearly moved along the inside of the container, and an adjustment means that is rotatably connected to an end of the container and screw-engaged with the lead supporting means. Meanwhile, provided on the outer circumference of the lead supporting means are a plurality of grooves, while a plurality of corresponding protrusions are formed on the inner circumference of the container in an axial direction. Accordingly, as the protrusions are slid along in contact with the grooves, the lead supporting means is moved inside of the container in a linear direction.
Since the lead supporting means is screw-engaged with the adjustment means, the lead supporting means is subject to a propelling force in the axial direction when the adjustment means is rotated. And since the protrusions of the lead supporting means are in contact with the grooves of the container, the lead supporting means is linearly moved inside of the container in an axial direction, instead of being rotated. Accordingly, the bar type lead element, which is connected with the lead supporting means, is either advanced out, or retracted into the container.
Meanwhile, the bar type lead element is shaped by cooling thus solidifying the high temperature raw material in melt state at a room temperature. More specifically, a nozzle is inserted into the container to inject the melt raw material therethrough. Then by cooling the raw material in the container, the raw material solidifies into the shape identical to that of the interior of the container.
One example of conventional method of forming the lead element for the writing implement is as follows. First, with the lead supporting means being assembled with the adjustment means, the assembled lead supporting means and the adjustment means are connected to the rear end of the container. Next, the container is made stand upright with its front end facing upward, and the nozzle is inserted into the container through the front end of the container. Then, the raw material in melt state is injected into the container through the nozzle, and solidifies into the complete lead element.
However, according to the conventional method for forming the lead element, after the solidification of the raw material, the leading end of the lead element is formed plane. As the plane tip end of the lead element is not appropriate for writing, it is necessary to sharpen the leading end of the lead element. Accordingly, the manufacturing process becomes complex, and the automation of the manufacturing process is hardly achieved.
As another example of the conventional method of forming the lead element, there was a method that a pointed cap is connected to the front end of the container and the container is made stand upright with its front end and the pointed cap facing downside. Then the nozzle is inserted into the container through the rear end of the container, and the raw material in melt state is injected through the nozzle and solidifies therein.
By the above method, since the leading end of the lead element is formed inside of the pointed cap into a rounded point, requirements for the process of sharpening the leading end of the lead element after the solidification can be omitted. However, this method has the following drawbacks.
According to the second example of the conventional lead element forming methods, the lead supporting means is assembled in the container only after the injection of the melt raw material. Accordingly, the lead supporting means has to be assembled in the container immediately after the injection of the raw material into the container. The problem is that the assembling process of the lead supporting means and the container requires manual work, as it requires personal attention to accurately fit the grooves on the outer circumference with the protrusions formed on the inner circumference of the container. In other words, the assembling process can hardly be automated, and thus, efficiency in this process cannot be expected.
Further, in the case that the assembling of the lead supporting means is delayed, i.e., in the case that the lead supporting means is assembled after the raw material already solidifies to some extent, the lead supporting means and the container can be assembled incompletely, and as a result, the lead element can not be supported stably by the lead supporting means. With the lead element being supported by the lead supporting means unstably, the lead element is easily escaped out of the lead supporting means during the retreat because of the frictional force generated between the outer circumference of the lead element and the inner circumference of the container.
Meanwhile, the conventional writing implement constructed as above also has a problem of having a waste, such as the scrapes of the lead element during a movement of the lead element by the friction with the inner surface of the container.
More specifically, the conventional writing implement has the protrusions formed in an axial direction along the inner circumference of the container, another protrusions formed on the outer circumference of the lead supporting means for being connected with the protrusions of the container, and still another protrusions formed in an axial direction along the outer circumference of the lead element that has the corresponding shape as that of the inner circumference of the container. Further, being screw-engaged with the adjustment means, the lead supporting means is subject to the rotational force as well as to the propelling force when the adjustment means is rotated. The rotational force is exerted to the lead supporting means in a forward direction when the lead element is advanced, and then exerted in the opposite direction when the lead element is retreated. Meanwhile, the grooves of the lead supporting means and the protrusions of the container are formed at certain clearance. Accordingly, during the advance and retreat of the lead element, the lead element is subject to a pressure by the protrusions of the container in one and opposite directions as much as the distance of the clearance. As the lead element is pushed against the grooves, the lead element often collapses or its outer surface breaks off.
Further, the outer circumference of the lead element is concaved for an engagement with the inner circumference of the container. Thus, when the lead element is advanced out of the container, the writing implement has a degraded appearance due to such concaved surface.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the above-mentioned problems of the prior art, and accordingly, it is an object of the present invention to provide a writing implement enabling a simp
Amos Corporation
Dickstein , Shapiro, Morin & Oshinsky, LLP
Nguyen Tuan N.
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