GB2233610A - Compact pen with extendable body - Google Patents

Abstract

A pen has a main body 6 comprising two tubular sections positioned one inside the other, the inner section 4 houses the refill 5 and is able to slide partially in and out of the outer section 3 through a bush 9 adjacent to its open end, allowing extension of the pen to a suitable length for writing. A cap 1 connects to the main body 6 and encloses the nib of the pen when the inner section 4 is in its retracted position, resulting in a pen which is compact for storage. The inner section 4 incorporates means for controlling its sliding motion during extension or retraction by cooperation with grooves or depressions in the curved inner surface of the outer section 3. The means may comprise spring-loaded balls 10 which engage in depressions 13 or 16 so as to lock the body in its retracted or extended position. The balls may run along grooves 14, extending parallel to the pen axis, during the course of the sliding motion. The cap may incorporate means for attaching a key ring or cord. <IMAGE>

Description

COMPACT PEN This invention relates to a compact pen.

Pens are essential everyday tools for recording information.

There are pens which are designed to be compact in order to fit in a handbag, pocket or to connect to a key ring. Most such pens are designed to overcome the same problem in a novel way i.e. how to quickly and easily extend the pen to a reasonable length when required for writing from the compact storage size.

However, due to the limitations of their designs none of the key ring pens have the appearance of a conventional pen, few are suitable for manufacturing in metal, and most are also not suitable for connecting to other items, via a split ring or other type of connecting device, since they require writing to be carried out whilst still attached to this intermediate connection. This also makes writing uncomfortable when keys are connected.

According to the present invention there is provided a compact pen comprising two predominantly tubular sections positioned one inside the other, a pen refill and a detachable cap, where the detachable cap encloses the nib of the pen, the outer tubular section is closed off at one end and has a bush which forms the opening at the opposite end to allow the inner section to slide partially in and out, and the inner section houses the pen refill and incorporates, adjacent to the end opposite that from which the nib emerges, means for controlling the sliding motion of the inner section by cooperation with grooves or depressions in the curved inner surface of the outer section.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: - Figure 1 shows the pen as it would be stored, with inner section retracted and the cap attached to the main body of the pen. In this example the cap incorporates means for attaching an intermediate connecting device such as a split or key ring, a neck cord, or a connecting band.

Figure 2 shows the main body of the pen separated from the cap, the inner section of the main body being in the retracted position.

Figure 3 shows the main body of the pen with the inner section extended for writing.

Figure 4 shows a longitudinal section of the pen cut through the central axis and the points at which spring loaded balls touch the inner surface of the outer section when the inner section is in its retracted position, and the cap is attached to the main body of the pen (attachment ring not shown).

Figure 5 shows a cross sectional view of the main body of the pen at one of the positions where the balls touch the inner surface of the outer section, when the balls are moving along grooves as the pen is being extended.

Figure 6 shows a cross sectional view of the main body of the pen at the position where the balls touch the inner surface of the outer section, when the balls are located in depressions which lock the inner section in the extended position.

Referring to the drawings the pen comprises a detachable cap 1 which encloses the nib of the pen and may incorporate means 2 for attaching a connecting ring such as a key ring, a cord or any other intermediate connecting device, two predominantly tubular sections positioned one inside the other - the outer section 3 and the inner section 4, which together with the pen refill 5 housed in the inner section, form the main body of the pen 6.

In order to use the pen for writing from its storage position1 as shown in Fig 1, the main body of the pen 6 is first detached from the cap 1 by releasing the connection 7. This connection 7 is shown in Fig 2 as a simple press fit but could be any of a number of different connections such as a screw thread or a press fit in which the cap connects to the pen via three equidistant dimples which extend radially from the main body of the pen and which are compressed equally as the cap passes over them. After detachment, the cap 1 is left hanging on the aforementioned intermediate connecting device by the attachment ring 2, and the main body of the pen 6 can be extended for writing. In cases where the pen is not required to incorporate means 2 for attaching a connecting device, the cap can be adapted to connect to the plug 22, to further lengthen the pen.

Extension is carried out by holding the tapered part 8 of the inner section 4 and pulling outwards, away from the outer section 3. After initial resistance the pen extends smoothly until an audible click is heard, which indicates that the pen has reached its maximum extension. The pen is then locked in the extended position as shown in Fig 3 by twisting the inner section until a second click is heard. This is the position used for writing.

The smooth action in extending the pen is achieved by a combination of the bush 9 which forms the opening in the outer section 3 as shown in Fig 4, and the spring loaded balls 10 which extend from the curved surface of the inner section 4, and rotate or slide along grooves in the inner curved surface of the outer section 3. The motion of the balls 10 is arrested with the pen in each of the three positions - retracted, fully extended and locked, by means of the balls engaging in each of three sets of depressions adjoining the grooves.

The effect of pulling the inner section outwards from the retracted position is to compress the spring loaded balls 10 until they are released from the retracted position depressions 13. After the balls emerge from these depressions 13 they move into the extending tracks 14 as shown in Fig 5, which are straight grooves running parallel to the axis of the pen. Low friction plates 15 may be included to help the balls rotate as they move along the extending tracks 14. The motion of the balls is arrested on engaging in the fully extended position depressions 16, the click being produced as the balls spring into these depressions. The twisting motion required for locking the pen in the extended position compresses the spring loaded balls again until they are released from the extended position depressions 16, and move into the locking tracks 17, as shown in Fig 6.The locking tracks 17 are similar to the extending tracks 14 but run along the curve of the inner surface of the outer section, perpendicular to the extending tracks. The balls rotate or slide along the locking tracks until finally arrested by the locked position depressions 18, producing the second click as they spring into the depressions.

At each stage during the operation of extending (or retracting) the pen the studs 19 shown in Figs 5 & 6, which move in the guiding grooves 20 in the inner curved surface of the outer section, ensure that the balls do not come out of their grooves or over run the depressions. The guiding grooves 20 thus run parallel to the extending tracks 14 and the locking tracks 17. The studs do not normally touch either the base or the sides of the guiding grooves since the grooves are deeper than the studs are long, and the width of each groove allows the balls to make small deviations from their paths whilst ensuring that they never deviate beyond a point from which they will not spring back. Both the studs 19 and the balls 10 extend from the curved surface of a plug 11, which closes off the end of the inner sections opposite that from which the nib 12 emerges.

To increase the effectiveness of the locking action which locks the pen in the extended position, the guiding grooves 20 can be adapted to hold the studs 19 in this position.

In order to retract the pen from the locked position the inner section 4 is twisted in the opposite direction to that in which it was locked until an audible click is heard. The inner section is then pushed into the outer section, by holding the tapered part 8, until a second click is heard. The mechanism utilised in retracting the pen operates in the same way as that described above for extending the pen.

The pen refill 5 is replaced, when the pen is in the extended position1 by releasing the connection 23 shown in Fig 4 as a screw thread, which detaches the tapered part 8 from the inner section. The connection 23 could be one of a number of different connections such as a press fit or a bayonet type connection, but if a simple screw thread connection is used here it should tighten in the same direction as that in which the inner section is twisted to lock the pen, thus avoiding the possibility of this twisting motion unscrewing the connection.

The reverse twisting motion required for unlocking the pen can then be carried out by holding the cylindrical part of the inner section rather than the tapered part. An alternative arrangement for changing the pen refill 5 is to replace the two fixed plugs 11 and 22, which close off one end of the inner and outer sections respectively, with detachable ones connected by, for example a screw thread. The refill could then be changed in the retracted position by unscrewing the plug in the outer section, removing the inner section from the outer section, then unscrewing the plug in the inner section before replacing the refill.In this case the spring loaded balls 10 need to be permanently held in the plug 11 to facilitate removal of the inner section, where as in the arrangement described previously with the plugs 11 and 22 permanently fixed, there is no need to produce the plug, spring and balls as one unit.

One or more holes may be incorporated in the main body to allow air to flow in and out as the pen is being extended or retracted. A suitable hole 21 is shown in Fig 4, through the centre of the plug 22 which closes off the outer section 3.

The tubular part of the outer section 3 is suitable for manufacturing in a number of materials such as metal or plastic, but could also be a combination of two or more, for example - a thin walled metal tubing fitted with a moulded plastic lining containing all the grooves and depressions.

Instead of using the studs 19 for preventing the balls from leaving their grooves or depressions, it is possible to ensure that the spring 24 will not compress to this extent, by choosing a spring with a suitable solid length or adding a spacer through its centre.

A further, simpler example of the invention will now be described which has a similar construction to that described above and shown in the accompanying drawings, but which differs in the ways described below.

Instead of the spring loaded balls 10 running along grooves whilst the pen is being extended or retracted, they are free to rotate or slide in any direction along the curved inner surface of the outer section 3. The retracted and fully extended position depressions 13 and 16 are replaced with two circular grooves around the inner surface of the outer section, perpendicular to the axis of the pen.

To extend the pen from the retracted position, the inner section 4 is pulled outwards as in the first example, until an audible click is heard indicating that the pen has reached its fully extended position. This is the position used for writing.

The effect of pulling the inner section 4 outwards from the retracted position is to compress the spring loaded balls 10 until they are released from the retracted position groove They then rotate along the inner surface of the outer section 3 until arrested in the fully extended position by means of the balls 10 engaging in the extended position groove, the click being produced as the balls spring into this groove.

Since the balls are not required to rotate or slide along grooves, there is no need for the studs 19 and guiding grooves 20 described in the previous example. To ensure that the balls do not over run the extended position groove, the plug 11 from which the balls 10 extend could be given a larger diameter than the aperture of the bush 9. The bush 9 and the extended position groove can thus be spaced so that if the balls 10 over run the groove they are stopped as the plug 11 makes contact with the bush 9, in a position from which the balls will always spring back into the groove.Similarly, the space between the plug 22 which closes off one end of the outer section and the retracted position groove can be made such that the balls are prevented from over running this groove by the position in which contact is made between the two plugs 11 and 22 which close off the inner and outer sections respectively.

The pen can be retracted from the extended position by holding the tapered part 8 of the inner section 4 and pushing it into the outer section 3, until an audible click is heard which shows that the pen is fully retracted.

In either of the above examples the spring loaded balls 10 could be replaced with any spring loaded or resilient means for cooperating with grooves or depressions in the curved inner surface of the outer section 3, for example, any smooth spring loaded components incorporated in the plug 11, a different sort of plug 11 made from plastic with dimples on its outer surface - designed so that the dimples press against the inner surface of the outer section 3 in order that they can slide along it, or a spring steel ring with protruding -dimples connected to the inner section 4 and acting in a similar way to the plastic dimples.

Claims (10)

1. A compact pen comprising two predominantly tubular sections positioned one inside the other, a pen refill and a detachable cap, where the detachable cap encloses the nib of the pen, the outer tubular section is closed off at one end and has a bush which forms the opening at the opposite end to allow the inner section to slide partially in and out, and the inner section houses the pen refill and incorporates, adjacent to the end opposite that from which the nib emerges, means for controlling the sliding motion of the inner section by cooperation with grooves or depressions in the curved inner surface of the outer section.

2. A compact pen as claimed in Claim 1 wherein the means for controlling the sliding motion of the inner section press against inner curved surface of the outer section.

3. A compact pen as claimed in Claim 1 or Claim 2, wherein the means for controlling the sliding motion of the inner section rotate or slide along the curved inner surface of the outer section during extension or retraction, and click into grooves at the positions where the pen is fully extended or retracted.

4. A compact pen as claimed in Claim 1 or Claim 2, wherein the means for controlling the sliding motion of the inner section rotate or slide, during the operations of extension or retraction, along a series of one or more grooves connected end to end in the curved inner surface of the outer section, and click into depressions when the end of each groove in the operation is reached.

5. A compact pen as claimed in Claim 4, wherein studs which move in grooves in the inner curved surface of the outer section, are provided on the inner section adjacent the means for controlling the sliding motion of the inner section, to prevent deviations from the intended path of these means whilst the pen is being extended.

6. A compact pen as claimed in any preceding claim, wherein the means for controlling the sliding motion of the inner section are spring loaded balls.

7. A compact pen as claimed in any preceding claim, wherein means for attaching a connecting ring such as a key ring, a cord or any other intermediate connecting device are incorporated in the cap.

8. A compact pen as claimed in any preceding claim, wherein the means connecting the detachable cap to the the pen is a press fit in which the cap connects to the pen via three equidistant dimples which extend radially from the main body of the pen and which are compressed equally as the cap passes over them.

9. A compact pen as claimed in any preceding claim, wherein the pen refill is replaceable by releasing a connection near the end of the inner section from which the nib emerges.

10. A compact pen substantially as described herein with reference to Figures 1-6 of the accompanying drawings.