MXPA00004812A - Writing instrument with cartridge spacing element - Google Patents

Abstract

An improvement for a writing instrument (10) consists of an elastomer spacing element (32) disposed within the interior (16) of the writing instrument (10). The improved writing instrument (10) accepts ink cartridges (18) that are within a range of lengths. Relatively short cartridges (18) are held in place, and prevented from independent movement by the spacing element (32). Conversely, relatively lengthy ink cartridges (18) cause the spacing element (32) to be compressed.

Description

WRITING INSTRUMENT WITH CARTRIDGE SPACING ELEMENTS BACKGROUND OF THE INVENTION TECHNICAL FIELD The present invention relates to an improvement for writing instruments, where the writing instrument can easily and economically accept ink cartridges longer or shorter than the normal length . Particularly, the improvement includes a resilient spacing element that decreases the nominal length of the cartridge chamber, but allows a compression contact with a cartridge longer than the nominal length. COMMENTS ON THE RELATED ART Instruments for writing with ink are well known in the art and are available in both disposable and non-disposable forms. The non-disposable forms typically employ replaceable ink cartridges that are inserted into a chamber within the instrument. When a replaceable ink cartridge runs out, a user simply removes it and inserts a new cartridge. Not all cartridges are suitable for all writing instruments; Non-disposable writing instruments that use ink cartridges are typically constructed with the intention of employing cartridges of a specified length. Accordingly, a user must frequently rely on a brand or type of cartridge for a particular writing instrument. What complicates this situation are cartridges that are close to normal size but in some way slightly shorter or slightly longer. The shorter cartridges may fit within a prior art writing instrument, but due to the fact that they have a length less than the normal length they remain loose inside the cartridge chamber. Even when the user can make use of the writing instrument with a cartridge of this type installed, the cartridge tends to slide in the chamber resulting in a noise and a feeling of instability in the user's hand, thus preventing the user from making smooth strokes. Ink cartridges slightly longer than normal length are similarly problematic. When a cartridge is substantially larger than normal, the user can realize at a glance that it will not fit inside the chosen writing instrument. However, in the case of cartridges that are only slightly larger than normal, the user will not be able to tell if the cartridge fits or not until the user tries to place it inside the cartridge chamber. Most non-disposable writing instruments consist of two or more separable sections which, when attached, create the cartridge chamber and wrap the ink cartridge. When the sections of a particular writing instrument are connected and released by screwing and unscrewing complementary threaded portions, the writing instrument may, by incompletely screwing together the portions enclose an excessively long cartridge. This is still unsatisfactory for the user, however, since the instrument has the tendency to further unscrew, to the point of disassembling. In addition, the incomplete joining of the instrument segments will probably cause a feeling of discomfort for the user. SUMMARY OF THE INVENTION Taking into account the disadvantages of the prior art, it is an object of the present invention to provide a writing instrument that can safely accept ink cartridges having a shorter than normal length, such that the cartridges do not move easily inside the cartridge chamber. It is a further object of the present invention to accept cartridges that are longer than normal without affecting the external appearance or assembly of the writing instrument. It is also an object of the present invention to offer the aforementioned advantages with a device that is both simple and occupies a small area within the writing instrument. In a writing instrument in accordance with the present invention, an improvement is provided that includes an assembly of spacing elements that allows the insertion and use of ink cartridges within a range of lengths. A conventional non-disposable writing instrument includes a main cylindrical portion enclosing a chamber in which an ink cartridge is located, an upper end from which the writing tip of the ink cartridge protrudes, and a lower end. Connected to the lower end of the writing instrument through a support member is a spacer element in the form of an O-ring. When the chamber is empty, the spacing element reduces the length of the ink cartridge chamber thus allowing relatively shorter ink cartridges to be inserted and comfortably lodged there. Relatively long cartridges can also be inserted, in this case the spacing element is compressed, thus lengthening the ink cartridge chamber. BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects and advantages of the present invention will be more readily apparent from the following detailed description to be read in conjunction with the accompanying drawings in which: Figure 1 is a perspective view of a writing instrument in accordance with the present invention; Figure 2 is a longitudinal sectional view of a writing instrument employing an embodiment of the present invention; Figure 3 is a longitudinal sectional view of a writing instrument in accordance with the present invention, with an ink cartridge placed there; Figure 4 is a partial cross-sectional view of the embodiment of the invention described in figures 2 and 3. DETAILED DESCRIPTION OF THE PRESENT INVENTION The following embodiments are described in the context of a writing instrument employing ink cartridges. Note that when the same reference number is repeated in relation to different figures, it refers to the corresponding structure in each figure. Figures 1 and 2 represent an illustrative embodiment of a writing instrument employing the present invention. The body of the writing instrument 10 consists of an upper portion 12 and a lower portion 14 which are rotatably joined to form a chamber 16 where an ink cartridge 18 (illustrated in Figure 3) is located. The button 26 is fixed on a lower portion 14 and forms an end of the writing device 10. When the writing instrument 10 is not being used, a cover 14 encloses the opposite writing end.

As can be seen in Figure 3, in normal operation, the upper portion 12 is fully connected to the lower portion 14 and the cartridge 18 substantially fills the longitudinal length of the chamber 16. The point 20 of the cartridge 18 extends through the a hole 22 of an upper portion 12 and a spacing element 32 reaches the lower end of the cartridge 18. In Figure 4, a button 26 can be observed to support a spacing element 32 for a flexible interaction with the cartridge 18. An element of spacing 32 compresses what is necessary to allow a writing instrument 10 to accept cartridges having a range of lengths. A cylindrical post 30, in this illustrative embodiment, extends from the surface 28 of the button 26, preferably at an angle of 90 °, to support a spacing element 32. The circumference of the opposite end of the post 30 is surrounded by a flange ring and, in accordance with what is described below, cooperates with the lower end of the cartridge 18. The outer diameter of the annular flange surrounding the upper end of the post 30 is larger than the internal diameter of the spacing element 32, thus ensuring an adjustment secure the spacing element 32 on the post 30. The cartridge 18 includes a hole extending inward from its opposite lower end button 26, of a slightly larger diameter than the annular flange surrounding the upper end of the post 30. When a relatively long ink cartridge is inserted, the hole receives the post 30 as a spacing element 32 is compressed. In an alternative embodiment, not illustrated, instead of being Overted by a flange, the upper end of the post 30 is chamfered. When an ink cartridge runs out, the user unscrews the main body of the writing instrument, removes the spent cartridge and inserts a new cartridge, typically by first inserting the tip into an upper portion 12 and then screwing a lower portion 14 over an upper portion 12. The present invention allows the user to insert a cartridge that does not extend fully towards the surface of the button 26 when the upper portion 12 and the lower portion 14 are screwed together. A spacing element 32 fills the space that would otherwise exist between the cartridge 18 and the button 26, thus preventing the cartridge 18 from slipping inside the chamber 16. Similarly, since a spacing element 32 can be compressed, the user can insert cartridges that are longer than a distance from the perforation 22 to the spacing element 32. Instead of being limited to the use of a cartridge -of that type with the upper and lower portions of the structure instrument partially unscrewed, a spacing element 32 will be compressed by the extended cartridge, and the post 30 will extend into the hole located in the corresponding end of the cartridge 18, without negative effect or affecting the appearance of the writing instrument. In an exemplary embodiment, the spacing element 32 is a deformed O-ring of 0.076 inches; Illustrative materials for its construction include various synthetic rubber materials such as nitrile, silicone and polyurethane. Depending on the material used, the maximum compression capacity of this mode is 0.018 inches. The above description is intended to illustrate, but not to limit. Accordingly, it will be apparent to those skilled in the art that modifications may be made with respect to the disclosed invention without departing from the scope of the claims presented below. For example, instead of using a spacer element in the form of an O-ring, thus providing a circular cross-section, an alternative embodiment employs a square cross-section.

Claims (12)

1. CLAIMS A writing instrument comprising: a main body having an elongated cavity within said body; an ink cartridge positioned within the elongated cavity of the main body, said cartridge having a length that does not exactly correspond to the elongated cavity; a spacer device positioned in said cavity at one end of said ink cartridge, comprising a flexible spacer and a spacer holder, said flexible spacer housing the length of the ink cartridge to provide a comfortable housing for the ink cartridge in the cavity.
2. The writing instrument according to claim 1, wherein the spacer is made of an elastomer.
3. The writing instrument according to claim 2, wherein the spacer is annular in shape.
4. The writing instrument according to claim 1, wherein the spacer holder is fixed on the main body.
5. The writing instrument according to claim 4, wherein the spacer is removably fixed on the spacer support.
6. The writing instrument according to claim 1, wherein the spacer flexibly contacts an ink cartridge shorter than a specified length, such that the independent movement of the ink cartridge within the ink cartridge is substantially eliminated. cavity of the writing instrument.
7. The writing instrument according to claim 1, wherein the spacer is compressed to allow the writing instrument to accept an ink cartridge longer than a specified length.
8. The writing instrument according to claim 1, wherein the spacer holder forms a first end of the main body.
9. The writing instrument according to claim 1, wherein the spacer holder comprises: a cylindrical body; a first end fixed on the spacer holder; And a second end opposite the first end.
10. The writing instrument according to claim 9, wherein the circumference of the second end of the spacer holder forms an annular flange.
11. 11. The writing instrument according to claim 9, wherein the ink cartridge comprises: a tip; a body, comprising a reservoir of ink; and one end; said end comprises a hole having a diameter greater than the diameter of the spacer holder.
12. 12. A writing instrument comprising: a main body defining a cavity for housing an ink cartridge, the ink cartridge having an associated length; and an annular element, composed of a compressible material, placed within a first end of the cavity; wherein the compression capability of the annular element allows the cavity to comfortably accommodate an ink cartridge having a length comprised within a range of lengths. The writing instrument according to claim 12, wherein the annular element is a bull. The writing instrument according to claim 13, further comprising a support post for securing the annular element on the main body.