Coating implements with material supply – Solid material for rubbing contact or support therefor – Including means to advance material
Patent
1996-11-20
1998-10-27
Stoll, William E.
Coating implements with material supply
Solid material for rubbing contact or support therefor
Including means to advance material
A43K 2122
Patent
active
058270000
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to writing instruments and more particularly to a modular mechanism for advancing the lead of a mechanical pencil.
Conventional mechanical pencils have a mechanism by means of which the pencil lead can be extended and retracted selectively by the user, often by depressing or twisting a button at the end of the pencil opposite the writing tip end. A drawback with conventional mechanical pencils of this type is that the mechanism can only take one particular size of pencil lead, for example 0.5 mm or 1 mm. There is generally no simple means by which the user can alter the pencil so that it can take a lead of a different size. If the user wishes to adapt the mechanical pencil to take a pencil lead of a different size, the user must disassemble the mechanism, which can be troublesome since reassembly requires that various springs and other components must be assembled in the correct order, and such components are often relatively small.
According to the present invention, there is provided a modular lead advancing mechanism receivable as an integral unit in a mechanical pencil, the mechanism having a lead feed for feeding a pencil lead out of a pencil, and force-transmitting means for transmitting a force from an operating button on the pencil to operate the lead feed.
The modular pencil mechanism can be simply fitted into a suitable pencil barrel adapted to receive the modular pencil mechanism. There are no loose components so that the user can easily change modules in order to be able to use pencil leads of a different size.
The modular pencil mechanism may have an outer sleeve having an external flange. The sleeve further may contain the operating parts of the mechanism, for example, the various springs, the lead feed clutch, etc. The external flange on the outer sleeve generally cooperates with a bearing surface within the barrel of an assembled pencil to provide support for the mechanism within the pencil barrel.
The force-transmitting means may be a lead guide which extends from, and is slidably movable within, the outer sleeve, the lead guide having a flange at its end opposite the writing tip end of the modular pencil mechanism. In an assembled pencil, the flange contacts a flange connected to the operating button of the mechanical pencil.
The mechanism may have a clutch for gripping the pencil lead, the clutch being fixed to, or integral with, the lead guide, there being a clutch band disposed around the clutch. Resilient means, for example a coil spring under compression, may be provided to act between the clutch band and the lead guide in order normally to tighten the clutch around the pencil lead.
Resilient means, such as a cushioning spring, may be provided to absorb shocks during writing or if the mechanical pencil in which the mechanism is fixed should be dropped on the writing tip end.
The present invention also includes a mechanical pencil structure having a modular pencil mechanism as described above.
Where the modular mechanism has an outer sleeve having an external flange, the pencil structure may have an internal annular recess which receives the flange. The pencil may have a tip portion removably fixed to a barrel, the tip portion being removable in order to allow the modular mechanism to be removed.
The pencil may have a button which may be depressed or twisted in order to forward or retract the pencil lead. Where the mechanism has a lead guide, depression or twisting of the button may cause the lead guide to be pushed forward within the mechanism in order to extend the pencil lead.
An example of the present invention will now be described with reference to the accompanying drawing, in which:
FIG. 1 is a cross-sectional view of a mechanical lead pencil structure;
FIG. 2 is a cross-sectional view of the writing tip end of the pencil of FIG. 1, showing the mechanism in more detail; and,
FIG. 3 is a cross-sectional view of a mechanism similar to that of FIGS. 1 and 2, however being constructed for a larger diameter pencil lead.
The mechanisms of FIGS. 1 and 2,
REFERENCES:
patent: 4620811 (1986-11-01), Kageyama
patent: 4969763 (1990-11-01), Kageyama et al.
patent: 4998837 (1991-03-01), Kageyama et al.
patent: 5052838 (1991-10-01), Tucker
patent: 5509743 (1996-04-01), Hao
Cekala Chester
Howley David A.
Parker Pen Products
Stoll William E.
LandOfFree
Writing instrument does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Writing instrument, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Writing instrument will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1608967