US 5,420,615 AGranted

Unitary body plotter pen

AssigneeKoh-I-Noor Inc.

InventorsWolfgang Witz, Bernd Bastiansen

Life of this patent

Estimating the term…

Loading patent…

Abstract

A unitary plotter pen construction useful as a disposable plotter pen. A writing tube is provided centrally and at the front end of a unitary hard plastic body element that defines a writing tube nib; a housing for a soft plastic pressure equalization chamber and an ink reservoir; and an adaptor structure for mounting with a plotter head. An axially extending pressure-equalization chamber is defined by soft plastic, lamella vent channel element that is inserted from the rear and axially against inner surfaces of the hard plastic body element. An upper end of the pressure-equalization chamber connects to the ink supply and a lower end connects to ambient air, through an annular cavity at the front end of the unitary body element. That annular cavity also may include transverse capillary spaces as a further protection against ink leakage from the pressure equalization chamber.

Claims8

Dependent claims

A tubular plotting pen having a writing ink reservoir, said plotting pen comprising:

(a) a unitary hard plastic body element having a front end and a rear end, said body element having an annular space proximate the front end thereof, said body element including
a writing tube nib portion that holds a writing tube,
a housing portion comprising a circular body potion, and
an adaptor portion configured to allow mounting of said plotting pen within a plotter head,
wherein said writing tube is fixed axially at the front end of said body element, wherein the rear end of said body element is rearwardly open, and wherein said body element has a central bore axially connecting said writing tube to the writing ink reservoir, the reservoir being disposed proximate to the rear end of said body element;
and
(b) a soft plastic vent channel element disposed within said housing portion at a location between the front and rear ends of said body element, said soft plastic vent channel element being inserted from the rear end of said body element in an axial direction into sealing engagement against a cylindrical inner surface of said body element at the location, said soft plastic vent channel element and said body element defining an axially extending pressure-equalization chamber therebetween;
wherein the pressure equalization chamber is communicated with writing ink in the central bore through a port in said soft plastic vent channel element that is proximate the rear end of said body element, and wherein the pressure equalization chamber is connected to ambient air through a passage in said body element that is proximate the front end of said body element;
and
wherein said soft plastic vent channel element comprises
(i) transversely extending lamella of a diameter less than an inner diameter of said circular body portion of said body element, and
(ii) a soft plastic annular sealing disc, that radially is compressed into sealing engagement by said body element within the annular space.

9 more elements

A tubular plotting pen having a writing ink reservoir, said plotting pen comprising:

(a) a unitary hard plastic body element having a front end and a rear end, said body element having an annular space proximate the front end thereof, said body element including
a writing tube nib portion that holds a writing tube,
a housing portion comprising a circular body portion, and
an adaptor portion configured to allow mounting of said plotting pen within a plotter head,
wherein said writing tube is fixed axially at the front end of said body element, wherein the rear end of said body element is rearwardly open, and wherein said body element has a central bore axially connecting said writing tube to the writing ink reservoir, the reservoir being disposed proximate to the rear end of said body element;
and
(b) a soft plastic vent channel element disposed within said housing portion at a location between the front and rear ends of said body element, said soft plastic vent channel element being inserted from the rear end of said body element in an axial direction into sealing engagement against a cylindrical inner surface of said body element at the location, said soft plastic vent channel element and said body element defining an axially extending pressure-equalization chamber therebetween;
wherein the pressure equalization chamber is communicated with writing ink in the central bore through a port in said soft plastic vent channel element that is proximate the rear end of said body element, and wherein the pressure equalization chamber is connected to ambient air through a passage in said body element that is proximate the front end of said body element;
and
wherein said soft plastic vent channel element comprises:
(i) transversely extending lamella of a diameter less than an inner diameter of said circular body portion;
(ii) a front sealing disc proximate a front end of said soft plastic vent channel element, said front sealing disc having a diameter equal to or greater than the inner diameter of said circular body portion;
and
(iii) a rear sealing disc proximate a rear end of said soft plastic vent channel element, said rear sealing disc having a diameter equal to or greater than the inner diameter of said circular body portion.

11 more elements

A tubular plotting pen having a writing ink reservoir, said plotting pen comprising:

(a) a unitary hard plastic body element having a front end and a rear end, said body element having an annular cavity proximate the front end thereof, said body element including
a writing tube nib portion that holds a writing tube, the annular cavity being concentric to said writing tube,
a housing portion comprising a circular body potion, and
an adaptor portion configured to allow mounting of said plotting pen within a plotter head,
wherein said writing tube is fixed axially at the front end of said body element, wherein the rear end of said body element is rearwardly open, and wherein said body element has a central bore axially connecting said writing tube to the writing ink reservoir, the reservoir being disposed proximate to the rear end of said body element;
and
(b) a soft plastic vent channel element, disposed within said housing portion at a location between the front and rear ends of said body element, said soft plastic vent channel element being inserted from the rear end of said body element in an axial direction into sealing engagement against a cylindrical inner surface of said body element at the location, said soft plastic vent channel element and said body element defining an axially extending pressure-equalization chamber therebetween;
wherein the pressure equalization chamber is communicated with writing ink in the central bore through a port in said soft plastic vent channel element that is proximate the rear end of said body element, and wherein the pressure equalization chamber is connected to ambient air through a passage in said body element that is proximate the front end of said body element;
and
wherein said plotting pen further comprises a disc element, disposed in the annular cavity, said disc element extending transversely to a longitudinal axis of said plotting pen and having capillary ducts formed therein.

7 more elements

Dependencies are inferred from the claim text.