EP0402558A1

EP0402558A1 - Extensible body ball pen

Info

Publication number: EP0402558A1
Application number: EP89830265A
Authority: EP
Inventors: Giuliana Mongardi
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-06-15
Filing date: 1989-06-15
Publication date: 1990-12-19

Abstract

The extensible body ball pen (1) comprises a handle outer body (2) housing, in its inside, a bottom portion (5) supporting a pen refill (4), and a top portion (6) associated with an outer end portion (7) preferably provided with a clip member (8), the bottom and top portions engaging with a double helical cam element adapted to cause the bottom portion to translate as the top portion is translated in an opposite direction.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an extensible body ball pen.
As is known ball pen are presently available,as well as other writing tools,which have very reduced size which can be increased as the pen is to be used.
These extensible writing instruments are generally formed by a cap member covering nearly completely the pen body and which,as the pen is used,can be engaged with the rear of the pen body,in order to increase the pen length and improve its handling characteristics.
These constructions,on the other hand,are rather impractical,since they include a separate element,that is the cap,which must be removed and then engaged with the rear of the pen body as the pen is to be used.
Other known pen embodiments comprise a snap driving mechanism,causing the writing point to be projected and withdrawn,without changing in any degree the length of the pen body.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide a new type of ball pen,having an extensible pen body the length variation of which can be obtained by a quick and easy movement,and which does not include any separate elements to be engaged at the rear of the pen body as an extension thereof.
Within the scope of this aim,a main object of the present invention is to provide such a ball pen which has a very reduced size,to be easily introduced in a bag,and which, in its use condition has a size which is comparable to that of a conventional ball pen.
Another object of the invention is to provide such a ball pen which comprises very simple and reliable operating means and which,moreover,can be made starting from easily available elements and materials,at a very small cost.
According to one aspect of the present invention, the above mentioned aim and objects,as well as yet other objects,which will become more apparent hereinafter,are achieved by an extensible body ball pen characterized in that said pen comprises an outer handle pen body housing, in its inside,a bottom portion holding a pen refill and a top portion associated with an outer end portion,said bottom and top portions engaging with a double helical cam element,adapted to cause the bottom portion to translate as the top portion is translated in an opposite direction.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will become more apparent from the following detailed description of a preferred embodiment thereof,which is illustrated,by way of an indicative but not limitative example,in the figures of the accompanying drawings,where:

figure 1 is a perspective schematic view in an exploded form illustrating the extensible body ball pen according to the present invention;
figure 2 shows a longitudinal cross-section view of the subject ball pen in the withdrawn or not use condition thereof;
figure 3 is another longitudinal cross-section view of the subject pen,in the projecting or use condition thereof;
figure 4 is a detail view showing a removable locking element for removably locking the bottom portion of the pen,the pen being shown in its use condition;
figure 5 is a schematic side view of the ball pen in its use condition;
and
figure 6 is a side view of the ball pen in its non use or withdrawn condition.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the figures of the accompanying drawings,the extensible body according to the present invention,which has been indicated overally at the reference number 1,comprises a handle or gripping outer body 2 which,as shown in the drawings,consists of two half bodies 2A and 28 which can be coupled to one another.
More specifically,the body 2 has an outer substantially square shape and is preferably provided,in its inside,with a cylindrical cavity or hollow indicated at 3.
In this cylindrical cavity 3 there are slidingly housed,as it will become more apparent hereinafter,a bottom portion 5,of cylindrical configuration,holding a pen refill 4 in its inside,and a top portion 6 also of cylindrical shape,and of hollow configuration,to the top end portion of which there is coupled an outer end portion 7,therewith a clip member is associated.
In the inside of the bottom portion 5 and top portion 6 there is provided a double helical cam element,consisting of a cylindrical bar 10,which is provided with two cylindrical helix slots 11 and 12,extending from the centre to the periphery and having opposite helix directions.
At an intermediate or middle portion there is provided an annular recess 13 therein there is engaged an abutment or stop resilient ring member 14,coupled in a corresponding annular groove 15 formed on the inner surface of the cylindrical cavity 3 of the body 2.
More specifically,said resilient ring member 14 is adapted to axially restrain the cylindrical bar 10 to prevent said bar from disengaging.
In the helical recesses 11 and 12 there are respectively engaged a first pin 20,rigid with the bottom portion 5 and a second pin 21,rigid with the top portion 6.
As shown,the pins 20 and 21 are slidingly hous ed in a longitudinal seat 23 which is correspondingly formed in the cylindrical cavity 3.
The engaging between the pins 20 and 21 and longitudinal recess 23 prevent the portions 5 and 6 from rotating,while allowing for them to translate.
Owing to the above disclosed coupling arrangement,if the top portion is subjected to a pulling force,this portion will be displaced so as to extend the pen body 2,with a consequent rotation of the bar 10,because of the engaging of the second pin 21.
As the bar 10 is rotated,because of the first pin 20 engaging in the first recess 11,the bottom portion 5 will be displaced in an opposite direction to the displacement of the top portion 6.
Thus,as the top portion 6 is caused to project or extend,the bottom portion 5 will be automatically extended to its writing condition,and the pen body will be brought to a length suitable for an easy handling.
In order to prevent the bottom portion 5 from being retracted because of the writing pressure exerted thereon,at the end of the first recess 11 there is provided a locking notch 30 in which can engage the pin 20,so as to prevent the bar 10 from rotating to retract the portions 5 and 6.
In order to withdraw said portions 5 and 6,it will be sufficient to press on the top portion 6 so as to cause the bar 10 to rotate and the portion 5 to withdraw.
From the above disclosure it should be apparent that the invention fully achieves the intended aim and objects.
While the invention has been disclosed and illustrated with reference to a preferred embodiment thereof,it should be apparent that the disclosed embodiment is susceptible to several modifications and variations all of which will come within the spirit and scope of the appended claims.

Claims

1- An extensible body ball pen,characterized in that said pen comprises an outer handle pen body housing,in its inside,a bottom portion holding a pen refill and a top portion associated with an outer end portion,said bottom and top portions engaging with a double helical cam element,adapted to cause the bottom portion to translate as the top portion is translated in an opposite direction.

2- A ball pen according to claim 1,characterized in that said body has an inside hollow in which there are slidingly housed said bottom and top portions.

3- A ball pen according to the preceding claims,characterized in that said helical double cam element consists of a cylindrical bar provided with a first and second helical hollow of opposite directions and extending from a middle portion of said bar.

4- A ball pen according to one or more of the preceding claims,characterized in that said bar is provided with a central hollow for housing a resilient ring member engaging in an annular groove formed on the inner cylindrical face of said body so as to prevent said bar from axially displacing.

5- A ball pen according to one or more of the preceding claims characterized in that said pen further comprises a first pin rigid with said bottom portion and housed in said first hollow or recess,and a second pin,rigid with said top portion and housed in said second hollow or recess,said first and second pins slidingly engaging in a longitudinal slot formed in said cylindrical hollow so as to prevent said bottom and top portions from rotating.

6- A ball pen according to one or more of the preceding claims characterized in that said first hollow is provided,at a free end portion thereof,with a locking notch adapted to engage with the first pin,to prevent said bottom portion from withdrawing because of a writing pressure.