EP0220487B1 - Writing instrument - Google Patents

Abstract

The cap for the writing instrument comprises a jacket mounted slidably on a sealing insert or sleeve which provides a sealed moisture chamber for the writing tip when the cap is on the writing instrument. Near the writing tip there is a circular bulge on the shaft of the writing instrument which enters into a sealing engagement with an interior passage of the sealing insert. On putting the cap on the writing instrument the sealing insert is pushed over the circular bulge until it contacts a contacting stop on the jacket. Then the circular bulge presses tightly into the sealing insert and it locks the jacket to the writing instrument so that the entire arrangement is kept in that position until the cap is removed. A signal slider is attached with the sealing insert which is extendable out from the end of the jacket in order to signal in its extended position the proper seating of the cap on the writing instrument. Erroneous indications of a sealed state are prevented with our invention.

Description

The invention relates to a cap and a writing instrument according to the preamble of claim 1.

Writing instruments with a damp tip, e.g. B. fountain pens, felt pens or the like. If they are stored, they are covered with a cap in which a damp space encompassing the tip should be sealed as well as possible to prevent the tip from drying out. Dried paint, especially with felt-tip or fiber-tip pens, quickly clogs the capillaries between the fibers that form the tip of the pen and can thus prevent ink from flowing in, so that the pen can no longer be used, even if it contains a sufficient supply of paint, and is either expensive cleaned or, what is more common, must be thrown away.

It is therefore important to ensure that the cap is properly seated on the writing instrument after it has been used.

There are a number of proposals to solve this problem satisfactorily, but generally better solutions are achieved with a more complicated and therefore more complex structure, which is often too expensive, especially for disposable writing devices.

A known writing instrument with a cap according to the preamble of claim 1 is described in US Pat. No. 1,838,543 in the form of a fountain pen with a cap that can be attached. Near the spring of the fountain pen, an annular bead is arranged on its shaft and a sleeve that can be slipped onto the shaft is provided, which surrounds the annular bead at a distance. Within the sleeve, axially displaceable, there is a sealing insert which has a tubular sleeve-shaped section which is open towards the writing instrument and is surrounded by narrow leaf springs which extend in the longitudinal direction. The ends of the leaf springs facing the fountain pen are bent inwards. A compression spring arranged between the sleeve and the sealing insert presses it in the direction of the receiving opening of the sleeve. A specially shaped ring groove is formed on the inner wall of the sleeve. When the opening of the sleeve of the sealing insert facing the mouth of the sleeve reaches this annular groove, the leaf springs can spread outwards and engage with their ends in the wall of the annular groove, so that the sleeve is held in this position.

If the fountain pen is inserted into the sleeve, its ring bead comes into contact with the mouth of the sealing insert and pushes it deeper into the sleeve. The spread leaf springs are bent back and engage behind with their inwardly bent ends the annular bead so that it is firmly gripped and pressed against the mouth of the sealing insert, in such a way that a seal is achieved.

The end of the sleeve facing away from the writing instrument is closed and has an axially movable signal slide which is pressed outwards by its own spiral spring. The inner end of the signal slide is provided with locking claws which can grip around the spherical end of a pin which lies within the sleeve and is coaxial to it and which in turn is connected to the leaf springs.

If the sealing insert is fully inserted into the sleeve, a snap-in engagement occurs with the end of the signal pin. After releasing the shaft of the writing instrument, it is pushed out of the sleeve a little together with the sealing insert, so that the signal slide is drawn into the remote end of the sleeve. The retracted signal slide thus signals that the holder for fastening the ring collar at the mouth of the sleeve is closed, while the extended signal slide shows a contrary state.

What is essential in the known writing instrument is its functional sequence: when the sleeve is placed on the writing instrument, the sealing engagement between the sealing insert and the damp room is first made and only then is this state indicated by the signal slide. When the sleeve is removed from the writing instrument, the display of the sealed state is released first, and only then is this state itself canceled. This sequence of functions ensures that an untimely display does not remain.

However, this great advantage is paid for by a very complex and complex structure. In addition, the known mechanism is not completely reliable: due to inclined insertion of the writing instrument into the sleeve or due to the bending of one of the leaf springs mentioned, there is a risk that the ring bead does not engage with the mouth of the sleeve, but with the inwardly angled end of a leaf spring . In this case, the sealing insert is inserted into the sleeve, the leaf springs assume their engagement position and the signal slide shows a sealed position without a sealing engagement between the sealing insert and the writing instrument, because the ring bead is not between the mouth and the claw-like Ends of the leaf springs, but outside of this area. Furthermore, so that the mode of operation of the known device is not impaired, the sleeve can be moved with a relatively large amount of play relative to the shaft of the writing instrument. If there is an inadequate seal between the ring bulge and the mouth of the sleeve, the writing tip cannot be prevented from drying out in the long term.

Writing instrument caps are known from DE-OS-3401 739 and DE-OS-3441 435 which have a sealing insert which can be displaced in the longitudinal direction

have, which is movable by the writing instrument, the writing instrument being inserted into or pulled out of a tubular sleeve-shaped section of the sealing insert under frictional engagement. A signal pin is attached to the sealing insert, which is visible when the insert is fully pushed onto the writing tip. The axial movement of the sealing insert is controlled by a limit force lock, which is designed so that the limit force when unlocking is smaller and greater when locking than the friction force to be overcome when inserting or removing the writing tip. If in the known writing instrument cap, as a result of wear or unwanted lubrication, the friction force when pulling out the writing tip is reduced, so that the above-mentioned relationship is no longer maintained, it cannot be ruled out with certainty that the sealing insert in its face away from the opening of the cap Position remains after pulling out the writing tip and the signal pin thus incorrectly indicates the tight fit of the writing instrument.

From DE-GM-7 314439 a fountain pen plug cap is known which has a sealing insert into which the shaft of a writing instrument can be inserted. The writing instrument is provided with an annular bead, which is engaged behind by a corresponding sealing surface of the sealing insert when the writing instrument is inserted. A display of the tight fit of the writing instrument is not provided in the known plug cap.

From DE-GM-7 222 646 a closure cap of a fountain pen is known, in which the cap or its sleeve snaps onto the shaft of the writing instrument. For this purpose, an annular groove is provided on the shaft, which cooperates with a corresponding locking bar on the inner surface of the cap or the sleeve.

A similar latching between a writing instrument cap and the device shaft is provided in the subject matter of DE-GM-6 911 249, whereby in the object known from this document the writing instrument shaft is provided with an annular bead and the inside of the cap is provided with a corresponding counter groove.

From DE-PS-827 760 a fountain pen with a screw-on cap is known. The closure cap contains an axially displaceable sealing insert. The sealing insert is biased towards the open end of the cap by a spring. An indication of the sealing of the writing instrument tip has not been provided for the three last-mentioned writing instruments.

Based on this prior art, the invention has for its object to further develop such a writing instrument in such a way that, while maintaining its aforementioned advantageous functional sequence, its construction is significantly simplified and, at the same time, the possibility of a false indication with insufficient sealing intervention is virtually eliminated.

According to the invention, this object is achieved in a writing instrument according to the preamble by the features of the characterizing part of claim 1.

In the solution according to the invention, a surprisingly simple, but particularly effective and functionally reliable arrangement is achieved precisely through the interaction of a plurality of individual features. In the invention, a ring strip is first provided on the shaft of the writing instrument, which no longer seals, as before, with respect to the mouth of the sealing insert, but rather can be inserted into the sleeve, being on the inner wall of the sleeve during the entire displacement distance in each of the positions assumed fits tightly.

In the writing instrument according to the invention, the latching no longer takes place between the sealing insert and device shaft, but between the latter and the sleeve, the latching point being arranged in such a way that latching can only occur when the sealing insert is first pushed on from the annular bead by the annular bead its corresponding stop in the sleeve has been pushed back and after that the ring bar has penetrated the sleeve enough to ensure the desired sealing. This means that the locking point is only reached in the state in which the desired sealing of the damp room is inevitably established. If the sleeve is released before reaching the locking connection, it is pushed back by the spring from the writing instrument, regardless of whether the ring bar pushes the sealing insert in front of it without clamping or how far the ring bead was already pushed into the sealing insert, so that the User immediately notices that the desired locking position has not been reached.

The signal slider is rigidly connected to the sealing insert and only protrudes from the end of the sleeve when there is proper sealing engagement. The signal slider can only protrude from the sleeve when it is held in its retracted position, that is, when the locking engagement between the sleeve and the shaft has taken place. Has the locking engagement z. B. has not yet taken place or is already released when the sleeve is removed from the writing instrument, then the spring acting between the sleeve and the sealing insert inevitably moves the sleeve into a position relative to the sealing insert when released that the signal slider firmly connected to it is no longer recognizable from the outside is.

The locking engagement is achieved by means of combined friction / positive locking by forming a ring strip on the surface of the barrel of the writing instrument and / or on the inner surface of the sleeve or by forming an annular groove on the inside of the sleeve opposite the ring strip on the barrel.

The writing device lock according to the invention thus has no further part apart from the shaft with writing tip, the sleeve, the sealing insert and the spring. It is of remarkably simple construction, inexpensive to manufacture and at the same time much more reliable than the generic known writing instrument with its many and complicated individual parts. Ultimately, it reliably precludes incorrect displays of the insertion position if there is no sealing intervention.

According to a preferred embodiment of the invention, an inner annular flange is formed in the sleeve which, together with counter-stops which are formed on the sealing insert, forms the end stops for the movement of the sealing insert relative to the sleeve with its two surfaces pointing in the axial direction. The particular advantage of this arrangement is that the devices forming the stops for the two end stops of the sealing insert do not have to engage behind one another in a complicated manner, but can be simple, without, however, the overall length of the sealing insert increasing unduly. Thus, this configuration ultimately serves to further simplify the construction of the writing device according to the invention.

However, in order to achieve a saving in parts, according to an advantageous embodiment of the invention, one of the counter-stops is made of resilient pawls, so that the sealing insert with these counter-stops is first passed through the ring flange when the writing device is assembled, but then because of the pivoting out of the pawls in the opposite direction can no longer happen. The pawls are preferably assigned to the stop which prevents the sealing insert from escaping from the sleeve in the direction of the writing instrument, since, because of the tubular sleeve-shaped section which has a relatively large diameter, assembly preferably takes place from this side of the sleeve.

According to a preferred embodiment of the invention, however, the sleeve is closed at this end with a transparent hood, which surrounds the signal slide in its outer end position. As a result, the inside of the sleeve is not only secured against the ingress of dirt, but also an unintentional pressing of the signal slider is avoided when the sleeve is attached to the shaft.

The sleeve of the writing instrument according to the invention, like the generic writing instrument, can overlap the shaft of the writing instrument. A preferred embodiment of the invention, however, is characterized by a shoulder formed between the shaft and the ring bar or annular groove and a radial second shoulder between a socket of the shaft having the annular bead and the ring bar or annular groove, the distance being dimensioned such that when the engaged sleeve is pushed even further onto the shaft, this sits on the shoulder, while a distance remains between the mouth surface of the sealing insert and the radial second shoulder.

It is essential to assign the individual structural measures such that the sleeve already sits on the first shoulder before the mouth of the sealing insert has reached the second shoulder. In this way it is ensured that if the sleeve is excessively pushed onto the shaft, as can be done with careless use, the writing tip does not strike the bottom of the tubular sleeve-shaped section. Rather, this configuration ensures that the writing tip is always protected and, moreover, that a well-sealed damp room with optimal volume is always maintained.

The sealing engagement between the ring bar and the inner wall of the sealing insert always ensures that the sealing insert is pushed onto the writing instrument only as far as is forced as a result of the sleeve being pushed onto the writing instrument, and that the writing instrument only then moves out of the sealing insert again when the sleeve is removed from the writing instrument. As a result, the functional sequence which is so advantageous in the generic writing instrument is retained without, however, the disadvantages of the known writing instrument mentioned having to be accepted.

What is essential in the invention is the arrangement of the stops which are effective between the sealing insert and the sleeve. In this sense, a preferred embodiment of the invention also consists in the fact that, when the sleeve is removed from the writing instrument, the end of the sleeve facing the shaft protrudes from the sleeve. The advantage of this arrangement results in particular when the material of the preferably integrally formed sealing insert is colored uniformly in a color assigned to the writing color of the writing instrument when the sleeve is neutral colored. Because then, when the sleeve is attached, the signal slide shows the color of the writing fluid of the writing instrument, while when the sleeve is removed, the end of the sleeve protruding from this shows the same color, so that overall it is prevented that sleeves and writing utensils that do not belong together are accidentally put together.

The holding force of the locking device exceeds in the writing device according to the invention the restoring force of the spring.

The invention is explained below with reference to the drawing. In the schematic drawing, an embodiment of the invention is shown, an axial section through the front part of a writing instrument according to the invention with attached sleeve is shown to the left of the central axis dividing the drawing, while the removed sleeve is shown in axial section in the right half of the figure.

Terms used in the text below such as "above" and "below" refer to the representation in the drawing, i. H. to a vertical orientation of the writing instrument, with its writing tip pointing upwards.

The figure shows a writing instrument 8, which has an elongated, essentially circular cylindrical shaft, not shown in the figure.

A socket 9 is inserted into the open end of the shaft, the section adjacent to the shaft merging flush into the outer surface of the shaft and extending it by an annular section. This section is offset radially inwards, a shoulder 12 being formed which extends essentially radially to the axis of the writing instrument 8.

On the shoulder 12 is an almost circular cylindrical, but a little widening upward extension, which has three distributed over the circumference, outwardly projecting longitudinal ribs, which extend from the shoulder 12 from about to the middle of the extension. The upper end of the extension has a bead-like ring strip 14 as a projecting annular thickening.

The socket 9 is offset radially inwards on the upper side of the ring strip 14, a substantially radially extending second shoulder being formed.

On the radially inner circumferential edge of the second shoulder, a circular cylindrical, upwardly extending section is attached, which ends in an only slightly radially projecting annular bead 16, from the top of which the socket 9 tapers in the shape of a truncated cone and ends in an opening in which a writing tip 10 is attached. A cap is placed on the socket 9 of the writing instrument 8 and consists of a sleeve 1, a viewing hood 2, a sealing insert 3 and a helical compression spring 4.

The sleeve 1 is on the outside as a substantially circular cylindrical; elongated nozzle formed, the outer circumference of which corresponds substantially to that of the shaft of the writing instrument 8. At its end facing the collar 12, the sleeve 1 has a radial contact surface which delimits the mouth of the interior of the sleeve 1. The sleeve 1 is further provided with an internal through-bore which, starting at the mouth surface 11, has a first circular-cylindrical section which is chamfered and offset towards the mouth surface 11. This first circular-cylindrical section extends axially over a little more than the length of the longitudinal strips or ribs, which, starting from the radial inner circumference of the annular collar 12, run along the outer surface of the mount 9. These three (or more) ribs are dimensioned such that they come into engagement with the first bore section when the sleeve 1 is pushed on under a slight interference fit.

The upper or inner end of the first bore section merges into a second, relatively long cylindrical bore section which extends over almost two thirds of the axial sleeve length. Arranged near the beveled section is an inwardly projecting locking bar 13, which is jumped over and gripped behind by the ring bar 14 on the socket 9 when the sleeve 1 is placed on the writing instrument 8.

At the top of the relatively long circular cylindrical bore section, an inwardly projecting ring flange 7 is formed, with an essentially radially extending upper and an essentially radially extending lower surface, the end of which, however, changes into a truncated cone-shaped bevel. The inward-facing ring flange 7 is shown in the figure as a continuous flange, but can also be divided into separate projections.

A third circular-cylindrical bore section extends from the top of the ring flange 7 to the upper end of the sleeve 1, the inside diameter of which is a little smaller than that of the second long bore section.

In the upper part of the third cylindrical bore section, annular beads can be formed, which, however, only protrude a little radially inwards.

At the lower end of the third bore section, axial webs are formed on the inner circumferential surface thereof, which end at a common radial plane.

From above, the viewing hood 2 is inserted into the third bore section, which is made of transparent plastic and has a tubular section closed at the top, which is inserted into the opening of the third bore section of the sleeve 1 and with its mouth on the upward-facing Surfaces of the described axial webs.

The sealing insert 3, seen from the bottom upwards, has a first, essentially tubular sleeve-shaped section with a downwardly directed end face 20 and a precisely circular cylindrical inner surface 18. The upper part of this tubular sleeve-shaped section is widened outwards in such a way that the tubular sleeve-shaped section is good be guided in the second bore section of the sleeve 1

can.

The thickened tubular sleeve-shaped section is offset on the outside towards the top to form a shoulder, between which and the lower radial surface of the ring flange 7 the helical compression spring 4 is inserted.

On the upper end of the third cylindrical portion of the sealing insert 3, a conical part is placed, which merges into an upwardly extending central web. The interior of the conical part forms a damp room 15.

The inner diameter of the bore 18 of the tubular sleeve-shaped section is matched to the outer diameter of the annular bead 16 so that it can be pressed into the bore 18 in a sealing manner and with slight resistance, then between the upper part of the socket 9 and the frustoconical part of the sealing insert 3 the writing tip 10 receiving damp room 15 is completed.

Parallel to the central web extending upward from the tubular sleeve-shaped section, four circumferentially distributed, axially extending and radially outwardly protruding longitudinal webs are attached to the central web, which are offset radially inward approximately in the middle of their extent to form a bevel 21 are. In the position shown in the left part of the figure, this bevel 21 is supported precisely against the correspondingly designed conical surface on the underside of the ring flange 7 and forms with this end stop that the movement of the sealing insert 3 into the sleeve 1 and from the writing tip 10 limited (upward) away.

The top of the central web is extended by a signal slide 17, which is formed by a central pin and a flange seated on its underside, with radially extending viewing plates being arranged between the central pin and the flange. These viewing panels are offset radially from the central axis at equal angular distances from one another.

On the underside of the flange resilient pawls 6 are provided on both sides opposite each other, the downward facing surfaces of which lie in a radial plane.

In the position of the cap shown on the right in the figure, in which the sealing insert 3 is pressed out of the sleeve 1 by the compression spring 4 until the last section of the sealing insert 3 having the end surface 20 protrudes from the sleeve 1, the radial surface sits on the Underside of the pawls 6 on the upwardly facing radial surface 5 of the flange 7, whereby the second end stop is formed for the movement of the sealing insert 3.

If the position shown in the left part of the figure is adopted, in which the bevel 21 of the longitudinal webs of the sealing insert 3 lie against the flange 7 from below, then the signal slide 17 extends into the interior of the transparent viewing hood 2, so that it is good from the outside can be seen. However, if the sleeve 1 has been removed from the writing instrument 8 or is not properly seated on it, the signal slide 17 assumes the position shown in the right part of the figure, in which it is completely retracted into the interior of the sleeve 1 and is therefore no longer recognizable from the outside .

As can be seen from the left part of the figure, when inserting the writing instrument 8 with its socket 9 into the bore 18 of the sealing insert 3, the annular bead 16 first comes into contact with the countersunk edge of the end face 20, the entry of the annular bead 16 into the bore 18 is initiated.

When the writing instrument 8 is pushed further into the sleeve 1, the sealing insert 3 is moved by the annular bead 16 against the action of the compression spring 4 until the bevels 21 come into contact with the underside of the flange 7. Since the sealing insert 3 can no longer move further into the sleeve 1, the socket 9 with the annular groove 16 is pressed into the bore 18 (with a further effective pushing force). Here, the ring bar 14 enters the inside of the sleeve 1, runs over the bevel between the first and second holes, jumps over the locking bar 13, which is formed on the inner surface of the sleeve 1, and engages behind it, thereby producing a locking engagement. Immediately after snapping in, the mouth surface 11 of the sleeve 1 comes into abutment against the shoulder 12, so that the sleeve 1 can no longer be pushed onto the socket 9.

If the sleeve 1 is released in this position, it can no longer spring off from the socket 9 under the pressure of the spring 4, since the locking engagement between the two locking bars 13 and the ring bar 14 is so strong that it does not fall due to the force of the compression spring4 can be overcome more.

In this position, the signal slide 17 appears in the viewing hood 2 and indicates that the damp room 15 has been properly sealed.

As can be seen from the figure, the radial second shoulder adjoining the top of the ring strip 14 is in a position opposite the end face 20 of the sealing insert 3, but at a distance from this end face 20, while at the same time the mouth face 11 and the shoulder 12 sit on one another. This prevents the writing tip 1 from being pressed too deeply into the sealing insert 3 or the stop 7, 21 being damaged by pushing the cap too tightly onto the writing instrument 8.

When the sleeve 1 is removed from the writing instrument 8, the rear grip between the strips 13, 14 is released. If you now let go of the sleeve 1, it is immediately pushed upwards by the compression spring 4, as a result of which the signal slide 17 disappears from the viewing hood 2. Now the stop 5, 7 comes into effect. Pull the sleeve 1 even further down, the pulling force is transmitted to the sealing insert 3 via this stop 5, 7 and this in turn is pulled off the writing instrument 8, the annular bead 16, which is in sealing engagement with the inner surface of the bore 18, being pulled out of the latter. When he is released, the cap can be removed from the writing instrument and used. When the cap is removed, the lower part of the sealing insert 3 protrudes from the sleeve 1 (cf. right half of the figure).

A coloring of the sealing insert 3 in a color which corresponds to the color of the writing fluid used and is the same as the coloring of the signal slide 17 and the portion protruding from the sleeve 1 is provided, so that both with the cap attached and with the cap removed, at any time User can be recognized which writing instrument 8 this cap belongs to.

Claims (7)

1. A cap and writing instrument comprising a shank having a moist writing tip (10) and an adjacent annular bead (16) at one end, the cap having an elongate jacket (1) for pushing over the shank and containing an axially movable sealing insert (3) containing a tubular sleeve portion open at one end for inserting the writing tip (10), and when the writing tip (10) is inserted it cooperates with the annular bead (16) to seal a closed moist chamber (15) receiving the writing tip (10), the device also comprising a pressure spring (4) for moving the sealing insert relative to the jacket in the direction towards the writing instrument, and also comprising abutments (7, 21) on the sealing insert (3) and jacket for limiting their motion relative to one another, a signal slide (17) on the end of the jacket remote from the writing instrument and adapted to be pushed out in independence on the position of the sealing insert (3), and a locking device which holds the writing tip (10) in the sealing insert (3),
characterised in that
the annular bead (16) is slidable into the sealing insert (3) and is adapted to be brought into sealing and clamping engagement with the bore (18) of the tubular sleeve portion, the signal slide (17) is secured to the sealing insert (3), and the locking device has an annular ledge (14) or an annular groove on the shank which is adapted to be brought into engagement with a locking ledge (13) or a cooperating groove on the inner surface of the jacket (1), and an axial spacing is provided between the annular bead (16) and the locking device (13, 14) such that locking engagement can be made only when the sealing insert (3) has reached the end of its travel and rests on one of the abutments (7, 21) of the jacket (1) and the annular bead (16) is pressed in sealing-tight manner into the sealing insert (3).

2. A writing instrument according to claim 1, characterised in that the jacket (1) is formed with an internal annular flange (7), the two sides of which form the abutments (7, 21), and a counter-abutment (6,21) engaging behind the annular flange (7) is formed on the sealing insert (3) near the signal slide (17) and near the tubular sleeve portion respectively.

3. A writing instrument according to claim 2, characterised in that the counter-abutment cooperating with the pressure spring near the signal slide (17) comprises resilient latches (6).

4. A writing instrument according to any of claims 1 to 3, characterised by a transparent hood (2) disposed on the jacket (1) and surrounding the signal slide (17) in its outer end position.

5. A writing instrument according to any of claims 1 to 4, characterised by a shoulder (12) formed between the shank and the annular ledge (14) or annular groove, and a radial second shoulder between a shank mounting (9) comprising the annular bead (16) and the annular ledge (14) or groove, the spacing being dimensioned so that when the jacket (1) after engagement is pushed further onto the shank, the jacket rests on the shoulder (12), whereas a spacing is left between the radial second shoulder and the mouth surface (20) of the sealing insert (3).

6. A writing instrument according to claim 3, characterised in that the annular flange (7) and the latches (6) cooperating with the pressure spring (4) are disposed so that when the jacket (1) is removed, the mouth surface (20) of the sealing insert (3) projects from the jacket (1).

Images