US 10,414,201 B2Granted

Pressure regulating device for writing tool and writing tool having the same

AssigneeSDI Corporation

InventorSzu-Yu Chen

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Abstract

A pressure regulating device for a writing tool has a deformable member. Minor air pressure variations in a pen tube of the writing tool can be regulated by deformation of the deformable member. Major air pressure variations in the pen tube can also be regulated by movement of the pressure regulating device. Thus, the pen tube of the writing tool can avoid internal air pressure imbalance caused by external high temperature or low air pressure. Before the writing tool is shipped from a manufacturer, the deformable member is pressurized in advance, such that the minor air pressure variation formed when a pen cap caps the writing tool offsets the air pressure pre-applied to the deformable member. Accordingly, ink inside an internal chamber does not spout out upon removal of the pen cap and the ink will not be overly dispensed or leak during writing.

Claims20

Dependent claims

A pressure regulating device for a writing tool, the pressure regulating device slidably mounted in a pen tube of the writing tool for dividing an interior space of the pen tube into an internal chamber and an external communication chamber, the pressure regulating device comprising:

a tubular member provided with an outer periphery abutting on an inner sidewall of the pen tube;
and
a deformable member disposed in the tubular member;
wherein when a pressure difference between the internal chamber and the external communication chamber is larger than a first predetermined value, the deformable member deforms toward the external communication chamber;
and
when the pressure difference between the internal chamber and the external communication chamber is larger than a second predetermined value, the pressure regulating device slides toward the external communication chamber relative to the pen tube;
wherein the second predetermined value is larger than the first predetermined value.

4 more elements

Dependencies are inferred from the claim text.