WO1982000115A1

WO1982000115A1 - Propelling pencil

Info

Publication number: WO1982000115A1
Application number: PCT/DE1981/000108
Authority: WO
Inventors: Feintechnik Gmbh Schmidt
Original assignee: Heinzmann W; Schmidt R; Gazecki P
Priority date: 1980-07-05
Filing date: 1981-07-03
Publication date: 1982-01-21
Also published as: DE3025585A1; EP0055752A1; DE3025585C2

Abstract

In this propelling pencil the feed of the lead is effected by a pusher (12) by means of mechanical nippers. The nippers (25) are provided at the end thereof with a tongs' head shaped like a sphere (33) adhered into an inner cone of the sleeve (27). In the casing (7) there is arranged a spring device for the axial backward and forward motions of the moving lead, having clamping pliers (50, 51) for the spring controlled lead. The clamping pliers are also movable by the thrust of the pusher (21). The nippers (25) comprising the lead nipping device (10) is not in direct connection with the lead feed and backward motion device (12). Thereby, an automatic transport of the lead during writing is provided and, if desired, a manual feed of the lead is also possible.

Description

FINE MINING PEN

The invention relates to a fine lead pencil with automatic mine feed, with a sliding part mounted axially displaceably in the tip of the device, the lead with a frictionally locking lead, a lead clamping unit, consisting of an axially displaceable spring sleeve that is encased in an unloaded state stored clamping pliers for the lead, and with a lead magazine axially displaceable against spring force by means of an actuating pusher.

Such a fine lead pencil with automatic mine feed is known from DE-OS 28 37 586. This known pin only works as long as there is a lead in the lead protection tube inserted in the sliding part and in the lead clamping unit. The reason for this is that the lead is pulled out of the lead clamping unit by a lead brake in the spring-loaded sliding part and pushed forward. This has the disadvantage that, during normal writing use, the clamping pliers cannot open so far that the almost weightless lead can fall into the actual clamping zone of the clamping pliers. However, should this happen by accident, it will not be conveyed further since it moves back and forth with the clamping pliers because the mine is not held or supported at its rear end. The well-known fine lead pencil only works

OMPI _ automatically as long as a lead is clamped between the spring-loaded sliding part and the clamp. In the transition area, in which this is not the case, an automatic mine advance is not possible with the known pen.

This essentially also applies to the known fine lead pencils according to DE-OSen 26 11 608 and 27 29 320.

In contrast, the invention is based on the object of creating a fine lead pencil which is always ready for writing and in which automatic mine transport is guaranteed during writing and thus continuous writing is possible without interruption. All fine mines in a mine magazine should be able to be automatically brought into writing position and written off one after the other. At the same time, however, a manually operated mine feed should also be possible. Practice shows that an additional manual operation option cannot be dispensed with in an automated fine-lead pencil, e.g. to be able to transport a lead more quickly, to remove remnants of lead or to be able to advance or retract a longer lead protection tube protruding from the writing tip (for example for use in the drawing) together with the thin lead leads.

This object is achieved according to the invention in that the clamping pliers have at their front end a pliers head formed from two symmetrical spherical caps, which is attached to an inner cone of the clamping widening towards the front.

ÖRE ^

OMPI sleeve comes into contact with the fact that between the mine clamping unit and the mine magazine, a spring-loaded mine advance and replenishment unit is axially displaceable in the housing and is axially firmly connected to the advance part by means of a connecting sleeve, the mine advance and replenishment unit opening towards the front , spring-loaded locking mechanism for the mine, which can be released by pressing the actuating button, and that the mine clamping unit is not in direct connection with the mine feed and replenishment unit.

An essential feature of the invention is therefore that the mechanism which triggers the fully automatic mine feed and replenishment has three function units arranged one behind the other, which are arranged coaxially in a housing and are directly or indirectly connected to one another and work in mutual interaction. _

Advantageous embodiments of the invention are protected in the subclaims.

Exemplary embodiments of the invention are explained in more detail with reference to the figures. It shows: .

FIG. 1 shows a partially sectioned side view of a first embodiment of the fine lead pencil according to the invention, FIG. 2 shows a side view of a second embodiment corresponding to FIG. 1,

FIG. 3 shows a level development of the switching sleeve used in the embodiment according to FIG. 2,

FIG. 4 shows a side view of a third embodiment corresponding to FIG. 1,

Figure 5 is a section along the line V-V in Figure 4 and

FIG. 6 shows a section along the line VI-VI in FIG. 4.

The same reference numerals are used in all figures for identical or corresponding parts.

As can be seen from FIG. 1, the three functional units provided according to the invention for advancing the lead are arranged in the housing part consisting of tip 1 and connecting bushes 2 and 3 and a threaded connection 4, and the complete mechanism thus formed is by means of threaded connections 5 and 6 housed in the actual pen housing 7, 8.

The three functional units arranged one behind the other consist of a sliding part 9 mounted longitudinally displaceably in the tip 1, a lead clamping unit 10 arranged within the connecting sleeve 11 and a lead directly connected to the moving part 9 by means of connecting sleeve 11. and replenishment unit 12.

OMPI Behind the mine feed and replenishment unit 12, the pressure actuator required for manual operation is arranged, consisting of the mine magazine 13, the back pressure spring 16 arranged between two stops 14, 15, the mine feed 17 connected to the mine magazine 13 with mine inlet funnel 18, mine passage bore 19 and Stop collar 44, which consists of the eraser unit 20 mounted in the mine magazine 13 and the actuation button 21 placed on the mine magazine 13. The action of the back pressure spring 16 keeps the stop collar 44 in contact with a stop shoulder 45 fixed to the housing when the actuation button 21 is not pressed.

The sliding part 9 consists of a writing tip 22 which is mounted so as to be longitudinally displaceable in the tip 1 and which protrudes only very briefly from the tip 1, and a mine holding part 23 which is fixedly connected thereto and which resiliently surrounds the lead and thereby prevents the Clamp remnant leaving residual mine falls out. The lead holding part 23 can be a sleeve made in a known manner from rubber-elastic material or, as illustrated and preferred here, a sleeve which has elastically resilient extensions 24 which engage the mine in a force-fitting manner and hold it in place. However, any differently designed lead holding part can also be used if it elastically encloses and holds the lead.

The lead clamping unit 10 consists of the actual clamping pliers 25 with the guide bush 26 attached to the rear end of the pliers, the clamping sleeve 27 surrounding the pliers,

OMPI the compression spring 28 arranged between the clamping sleeve 27 and the guide bush 26 and the compression spring 29 arranged between the clamping sleeve 27 and the connecting bush 2.

The clamping pliers 25, which are mounted in the clamping sleeve 27 via the expanded guide collar 30 and with the guide bush 26 in the connecting sleeve 11 with small radial play against the very low force of the compression spring 28, have a clamping bore on the side facing the tip ¬ tion 31, which is smaller than the mine passage bore 32 and 35 closely surrounds the mine and holds securely against the writing pressure. The clamping pliers 25 are slotted over part of their length and thereby have at least two radially resilient arms which are pretensioned in such a way that the pliers head 33 is opened when the clamping pliers are moved towards the tip and the pliers head in the towards the tip widening conical clamping bore 34 slides along the clamping sleeve 27.

A special feature of the invention is the pliers head 33 formed from symmetrical spherical caps. As a result, such favorable frictional conditions are achieved between the pliers head 33 and the conical clamping bore 34 of the clamping sleeve 27 that a very weak compression spring 28 is sufficient to fit the clamping pliers 25 close and hold the lead 35 securely, but on the other hand there is no jamming of the pliers head 33 in the conical clamping bore 34, even if the lead 35 is loaded with strong pressure when writing, so that the force for releasing the pliers head 33 from the conical clamping bore 34 goes to zero, ie a mine can be pushed through the clamping pliers 25 which are closed due to the direction of action of the compression spring 28 without great effort. At least two radially outwardly directed webs 36, 37 are attached to the guide bushing 26 and the clamping sleeve 27, which protrude outward through longitudinal slots 38 of the connecting sleeve 11. The function of these webs is described below.

The clamping sleeve 27, which is longitudinally displaceable against the force of the compression spring 29, is guided with a narrow radial clearance over the enlarged collar 39 in the cylindrical connecting sleeve 11 and over the enlarged collar 40 in a narrowed bore 41 of the connecting bush 2.

This ensures that the mine clamping unit 10 is guided exactly centrally over its entire length, which is a considerable advantage for the mechanical system to function properly.

The movement of the clamping sleeve 27 to the end of the pin is limited by the abutment edge 42 of the clamping sleeve against the narrowed bore 41 of the connecting bush 2. In the direction of the tip, the path "A" of the clamping sleeve 27 is limited by the webs 37 resting against the shoulder 43 of the connecting bush 2. If the clamping sleeve 27 is displaced by this path "A" towards the tip during manual actuation of the pressure pin, the lead, which is mounted in the clamping sleeve 25 and has a lead 35 clamped therein, conveys the lead into and out of the writing tip by the same amount . The exact functional sequence is described below. At its end facing the tip, the connecting bush 2 has at least two radially inward-pointing webs 46 which engage through longitudinal slots 47 at the front end of the connecting bush 11. As a result, the connecting sleeve 11 is mounted non-rotatably in the housing, as is the sliding part 9 attached to it and the lead clamping unit 10, as a result of which the lead cannot rotate when writing.

The mine feed and replenishment unit 12 is non-positively connected to the sliding part 9 via the connecting sleeve 11 at the rear end thereof and is supported by the mine feed guide 17, which is supported on the end face of the mine feed and replenishment unit 12 and the end face Compression spring 48 is always pressed in the direction of the tip, so that the sliding part 9 always bears against the shoulder 49 of the tip 1 in its front position.

Instead of the compression spring 48, the mine feed and replenishment unit 12 and the mine feed 17 can be made of magnetic material, the magnetic forces being directed so that they repel each other. It is thereby advantageously achieved that the sliding part 9 is very softly cushioned, which is very pleasant when using the refill pencil, since a compression spring cannot be set in terms of force as much as magnetic forces.

Of course, two magnetic rings, which repel each other, can also be accommodated in the space "in which the compression spring 48 is shown.

OMPI Rolling elements 51 are arranged in a recess of the mine feed and replenishment unit 12 which is provided with widening inclined surfaces 50 and which are always pressed towards the central axis of the pin under the action of the compression spring 52 and the direction of the inclined surfaces 50 and thereby strive to to close the opening between the rolling elements. A mine 35 inserted between these rolling elements 51 is thereby held firmly enclosed, a movement of the. Mine in the direction of the tapered inclined surfaces 50 increases the holding pressure, while a movement in the opposite direction immediately removes the pressure because the rolling elements 51 slide along the inclined surfaces 50 without friction. The pressure plate 53 acting on the rolling elements 51 ensures that the rolling elements lie in one plane, as a result of which the force distribution on the lead takes place exactly symmetrically and makes the effect considerably more effective.

In a further recess 54 of the mine feed and replenishment unit 12, a pressure sleeve 55 is axially displaceably mounted, which is defined by a boundary 56 in the direction of the end of the pin and which has a tapered extension 57 on the side facing the tip, the end face of which is provided with inclined surfaces 58 tapering towards the front. The rear end of the pressure sleeve 55 is mounted in a recess 59 of the mine feed 17 and has a small distance "D" from the shoulder 60 of the mine feed 17 when the mechanism is at rest. If a lead 35 is clamped between the rolling elements 51, there is a minimal distance between the surface of the rolling elements and the inclined surfaces 58, so that the pressure effect on the lead is not impaired. If there is no mine between the rolling elements, the inclined surface 58 prevents the opening between the rolling elements from being completely closed and thus preventing a mine following from the mine magazine 13 from blocking the way into the mine feed and replenishment unit 12. With a slight movement of the pressure sleeve 55 in the direction of the pen tip, the rolling elements 51 are opened via the inclined surfaces 58 and open the way for the subsequent mine into the mine channel of the mechanics.

As effective. Rolling elements can be used with wheels with a circumferential profile adapted to the shape of the lead, rollers or balls which slide along the inclined surfaces 50 without friction. However, it is also possible to use other elements, such as shaped springs, clamping rings, toothed disks and the like, which exert a small pressure force on the lead in one direction of movement and increase the pressure force in the other direction of movement.

A feed sleeve 61 is fixedly connected to the lead feed 17. A further feed sleeve 62 is axially movable on this feed sleeve ^' Λ and is limited in its movement by the stop 63. A compression spring 64, which is supported on the feed sleeve 62 and the suction collar 44 of the lead feed 17, always holds the feed sleeve 62 at the stop 63 in the rest position.

1 has the following mode of operation. It is assumed that there is no mine in the actual mechanics, but that all mines are still in the mine magazine 13.

When the pin is held approximately vertically, the leads rest against the tapered bore of the pressure sleeve 55. A A lead can move in the narrower lead passage bore of the pressure sleeve 55 until it contacts the rolling elements 51. Since the opening between the rolling elements is slightly smaller than the lead diameter in this state, the lead cannot slip. If the mine magazine 13 is now pressed into the interior of the pin against the force of the compression spring 16 via the actuating button 21 anueli, the following functional sequence is triggered. The lead feed 17 moves to the tip of the pen, after overcoming the small distance "D" it hits the pressure sleeve 55, pushes it forward, the rolling elements 51 are also pushed forward over the inclined surfaces 58 and due to the position of the inclined surfaces 50 moved radially outwards, whereby the opening between the rolling elements 51 becomes so large that the mine 35 resting thereon can slip through and up to the closed clamping bore 31 of the clamping pliers -. 25 falls. With the forward movement ^'of the lead feeder 17, the feed sleeve attached thereto, the feed sleeve 62 also moves 61 and over which ent exciting compression spring 64 to the front. The feed sleeves 61, 62 initially move forward synchronously. After passing through the distance "B", which is smaller than the distance "C", the feed sleeve 62 meets with its front side on the webs 37 of the clamping sleeve 27 and moves them against the action of the compression spring 29 by the distance "A". corresponds to the mine advance, also with forward. When the clamping sleeve 27 moves by the distance "1, the clamping tongs 25 held in the clamping sleeve in the closed state under the action of the compression spring 28 are simultaneously dragged along. When the webs 37 of the clamping sleeve 27 abut the stop edge 43, displacement occurs with further pressure actuation of the mine magazine 13 the feed sleeve 61 in the direction of the pen tip and, after passing through the distance "C", meets the webs 36 of the guide bushing 26 which is firmly connected to the clamping pliers 25 and thereby displaces the clamping pliers against the action of the compression spring 28 relative to the clamping sleeve 27 in the direction Through the slightly outwardly biased spring arms of the clamp pliers 25, the parts of the Pliers head 33 corresponding to the diameter expansion of the conical clamping bore 34 in the clamping sleeve 27 radially outwards, at the same time the clamping bore 31 opens so far that the mine lying against it until now is cleared of the way and it can slide into the lead holding part 23 of the writing tip 22.

After this feed movement, the pressure on the mine magazine 13 is released. The action of the compression spring 16 triggers a movement in the direction of the end of the pin, at the same time all components which are moved forward are returned to their starting position by the action of the compression springs acting thereon. After this return stroke path has ended, the mine is firmly clamped in the clamping bore 31 and the rolling bodies 51.

Now the feed movement described above is repeated a number of times, each time the lead held in the clamping bore 31 is pushed forward by the feed path "A" and passes through the resilient extension 24 of the lead holding part 23, which non-positively encompasses the lead, and through the bore of the writing tip 22 until ready to write. From this point on, the fine lead pencil is ready for fully automatic operation. All the mines in the mine magazine can now be prescribed without interruption; a manual feed movement, as described above, is no longer necessary.

The fully automatic mine feed and replenishment has the following functional sequence. Due to the reduction in length of the mine during the writing operation the front side of the sliding element 9 with the Aufzeich ^¬ drying carrier is in contact with and is moved against the action of the very soft compression spring 48 into the pin inside. The mine feed and replenishment unit 12, which is connected to the sliding part 9 via the connecting sleeve 11, is likewise moved in the direction of the end of the pin. The mine is firmly clamped in ^¬ _d it is not influenced by this movement Mine clamping unit 10. The lead holding part 23 and the Wälz¬ body 51 also slide back through the downer mine. When the writing pressure is relieved, ie when the writing tip is lifted from the recording medium, the lead feed and supply unit 12 with the connecting sleeve 11 and the sliding part 9 is moved in the direction of the pen tip by the action of the compression spring 48 until the sliding part 9 on the shoulder 49 in the tip 1 is present. Since the rolling elements, due to the position of the inclined surfaces 50 and the action of the compression spring 52, firmly enclose the lead, the lead is also transported to the tip of the lead during the forward movement of the lead feed and feed unit 12 and by the action of the very weak spring 28 closed clamp pliers 25 ^' pushed through.

The lead is therefore not pulled out of the clamp pliers 25 by the lead holding part 23 arranged in the sliding part 9, as in known systems, but, as described above, the lead is pushed through the clamp pliers.

This arrangement according to the invention of the mine advance and replenishment unit 12 behind the mine clamping unit 10 which is arranged independently of this gives the decisive advantage that the mines can be prescribed completely because the first residual mine leaving the clamping tongs 25 is a follow-up mine is pushed in seamlessly, so that the clamp pliers 25 do not have to be opened to pass the subsequent lead, as in known systems.

So that another mine from the mine magazine 13 can get into the mine passage of the mine feed and replenishment unit 12 and can follow the first mine seamlessly, the pressure sleeve 55 is arranged on the mine feed and replenishment unit 12 so as to be longitudinally displaceable. During the above-described movement of the mine feed and replenishment unit 12 in the direction of the end of the pin, the pressure sleeve 55 is also carried along and is supported on the shoulder 60 of the mine feed 17 after having traveled a very short distance "D". The mine feed and replenishment unit 12 moves back a little further, the opening between the rolling elements 51 is enlarged via the inclined surface 58 of the pressure sleeve 55, the path into the mine clamping unit 10 is thus opened for the follow-up mine from the mine magazine 13, so that it can do so seamlessly follow the first mine. During the forward movement of the mine feed and replenishment unit 12, the pressure sleeve 55 is immediately pressed back against the boundary 56 by the spring bodies 51 under spring pressure, the roller bodies 51 encompass the mine lying between them and bring them in the direction of the pen tip.

Instead of the shoulder 60 of the lead feed 17 which delimits the path of the pressure sleeve 55, the pressure sleeve can be frictionally mounted within the recess 59 of the lead feed. Caused by this frictional engagement there is also a forced opening of the rolling elements 51 so that the secondary mine reaches the mine passage channel.

"gTfREA C _/

OMPI The above-described opening and closing of the rolling elements 51 by means of the pressure sleeve 55 takes place in the same rhythm as during the writing process, the sliding part 9 is moved into the interior of the pen or, when it is lifted from the drawing carrier, is pushed forward again by the pressure spring 48, as a result of which a fully automatic refill - and replenishment is guaranteed until the last mine from the mine magazine is used up.

Another embodiment of the invention is shown in FIGS. 2 and 3. For fine lead pens, which are mainly used for technical drawing, it is necessary that the protective tube 65 surrounding the lead protrudes from the tip 1 by a greater length than with pure pens, so that these fine lead pens can be used on the ruler or in the stencil. For these fine leads pens is very advantageous and is also generally desired that the long protective tube 65 can be pushed completely back into the tip of the pen when not in use, so that it is protected against damage and also does not damage the items of clothing when inserted into a jacket pocket calls.

Known devices for sinking the protective tube into the housing are very complex and complicated. According to the invention, the shifting part 9, which works independently of the mine clamping unit 10 and has a connecting sleeve 11 attached to it and the mine advance and replenishment unit 12, can be brought into an advanced writing position according to FIG. 2 and a retracted protective position by means of switching curves.

The structure and the mode of operation of the fully automatic mine feed and replenishment unit 12, the mine clamping unit 10, the sliding part 9 and the connecting sleeve 11 fastened between them correspond to the description of FIG. 1.

- ÜREΛ _ζ

OMPI At the rear end of the connecting bush 3, in the embodiment according to FIGS. 2 and 3, instead of the radially circumferential stop shoulder 45 in FIG. 1, a cam sleeve 66 is fixed immovably, which preferably has two diametrically opposed maximum points 67 and two minimum points 68. On a switching sleeve 72, which is non-rotatably connected to the mine magazine 13, preferably two diametrically opposed and radially outwardly projecting switching cams 69 are arranged, which, due to the action of the compression spring 16, between the cam sleeve 66 on the one hand and the stop 14 of the mine magazine 13 is arranged on the other hand, are engaged with the curve 70.

In the position shown in FIG. 2, the switching cam 69 is located at the maximum point 67 of the cam sleeve 66, which is preferably provided with a snap-in recess 71. This state corresponds to the position of the mechanical parts as shown in Fig. 1. Via the compression spring 48, which is supported between the switching sleeve 72 and the mine feed and replenishment unit 12 .., the sliding part 9 is held with the protective ear 65 in its front end position. The fine lead pencil is ready for fully automatic operation.

If the protective tube 65 is now to be brought into its retracted position, which is completely sunk in the tip 1, a rotary movement is carried out manually via the actuating pushbutton 21, as a result of which the switching sleeve 72 and the switching cams 69 arranged thereon also perform a rotary movement via the mine magazine 13 experience, which is preferably limited in the end positions by stop webs 73. Due to the action of the relaxed compression spring 16, the switching sleeve 72 is moved with the switching cams 69 in the direction of the end of the pin, the switching cams 69 slide back on the falling curve to its minimum point 68. The height difference between the maximum point 67 and the minimum point 68 of the switching curve 70 is preferably equal to or greater than the protrusion of the protective tube 65 to be sunk from the tip.

As a result of the backward movement of the switching sleeve 72 by the difference in height of the switching curve 70, the distance between the front of the switching sleeve 72 and the rear of the mine feed and replenishment unit 12 increases to such an extent that the compression spring 48 is completely free in this space and does not exert any force on the mine feed and replenishment unit 12 and thus on the sliding part 9. The fully automatic function of the mechanics is now switched off.

In order to push back the protective tube 65 now, as described in relation to FIG. 1, a manual pressure actuation of the mechanics is carried out, thereby opening the clamp pliers 25 and releasing the lead. Simultaneously with the release of the pusher, the sliding part 9 with the protective tube 65 and the refill held therein ready for writing can now be pushed back into the pen tip 1. In the retracted position of the switching sleeve 72, in which the switching cams 69 bear against the minimal track 68 of the * curve 70, the lead is held by the clamp 25, which is closed again. Due to the non-positive connection to the mine

OMPI adjacent mine holding part 23, which is fixed in place in the displacement part 9, the displacement part 9 is held in the retracted position and is thereby protected against damage.

In the switched-off position of the fully automatic mechanism, the fine lead pencil according to FIGS. 2 and 3 also offers an additional special feature. The fully retracted protective tube 65 can be pressed into its foremost, extended position by pushing the actuating button 21 forward once. Now the fine lead pencil can be handled like a known "full-slide pressure pencil", since the sliding part 9 is not under the action of the compression spring 48, and accordingly can slide back into the tip of the pencil without resistance in accordance with the wear of the pencil.

In order to switch on the fully automatic function of the mechanics again, the switching sleeve 72 with the switching cam 69 is rotated again by a rotary movement via the actuating button 21. The shift cam 69 moves from the minimum point 68 along-the curve 70 through ^~ the maximum point 67 in ^{^"ie"} Einrast¬ recess 71, the front of the control sleeve 72 moves toward the Minenvor- and -nachschubeinheit 12, the compression spring 48 is again .biased. The starting position for fully automatic operation according to FIG. 1 is thus reached again.

A further embodiment of the invention is shown in FIGS. 4 to 6. It is often desired that the refill and protective tube are not pushed forward flush, but that the refill protrudes a little from the protective tube and can therefore be written off more easily . This wish is also taken into account in this embodiment. The overall structure of the push pin mechanism with the three functional units arranged one behind the other is essentially the same as in the exemplary embodiments according to FIG. 1

OMPI and 2. The / outstanding amount E of the mine 35 from the displacement part 9 is brought about by a translation part arranged between the displacement part 9 and the mine feed and replenishment unit 12, the mine feed and replenishment unit being integrated in this translation part. Since the translation part is not to be loaded in terms of force, the compression spring 48 is shifted into the writing tip 22 in this embodiment.

When the lead 35 is being written off, the sliding part 9 is pushed back as before, after the sliding part 9 has been reached, the connecting sleeve 11, which is connected in a form-fitting manner, simultaneously moving back. At the inner end of the connecting sleeve a molded part 75 is attached, which receives a gear 76 in a transverse slot. This is engaged on the one hand with a toothed rack 77 in a sleeve 78 and on the other hand with a toothed rack 79 which is connected to a cup-shaped part 80 which receives the refill and supply unit 12 in a form-fitting manner. The rolling of the gear on the rack 77 causes a ratio of 1: 2 to the rack 79 in the arrangement shown. The pot-shaped part 80 with the mine feed and replenishment unit 12 is thus pushed back twice as much as that Sliding part 9 is pushed back. The rolling elements 51 slide over the lead held by the clamp 25. When the writing instrument is lifted off, parts 1, 11, 75, 76, 80 and 12 are brought back into the starting position by relieving the pressure spring 48. The mine 35 is held by the rolling elements 51 and pushed by the clamping pliers 25, also by twice the distance, so that the mine 35 finally protrudes from the sliding part 9 by a certain amount "E". The manual actuation from the rear actuation button 21 takes place practically in the same way, with only all functional units lying in front of the gear 76 remaining stationary under the action of the compression spring 48 and only the cup-shaped part 80 with the lead feed and feed unit 12 around one Predeterminable amount, which corresponds to the double amount of the trigger path, is pushed back.

Only when the actuating button 21 is released is the mine 35 moved forward. With this arrangement, an advance stroke with the clamp A closed by the amount A is no longer necessary. The clamping sleeve 27 can thereby be mounted in a stationary manner in the connecting bush 2 of the housing.

The clamp pliers 25 can be opened only for manually pushing back the lead 35 protruding from the sliding member 9, as a result of which the lead is released. When the pusher 21 is actuated, the sleeve 78 is pushed forward and, after having overcome the distance "D", it meets the web 81 of the guide bush 26 connected to the clamping pliers 25 and, as a result, pushes the clamping pliers 25 to the tip 1.

As in the exemplary embodiments described above, the follow-up link is pushed in via the pressure sleeve 55.

The 1: 2 gear ratio could also be converted to any other gear ratio, for example by using two different sized gears. ^'

Claims

PATENT CLAIMS

Fine lead pencil with automatic lead advance, with a sliding part mounted axially displaceably in the tip of the device, the lead guiding the lead in a frictionally locking manner, a lead clamping unit consisting of a clamping pliers for the Mine, and with a mine magazine axially displaceable against spring force by means of actuation pushers, characterized in that the clamping pliers (25) have at their front end a pliers head (33) formed from two symmetrical spherical domes, which is directed towards one at the front widening inner cone of the clamping sleeve (27) comes into contact, - ~ that between the spring clamping unit (10) and the mine magazine (13) a spring-loaded lead and replenishment unit (12) in the housing (7) is axially displaceable and via a Connection sleeve (11) is axially fixed to the sliding part (9), the mine feed and replenishment units it (12) has a spring-loaded locking mechanism for the lead (35) which opens towards the front and which can be released by moving the sliding part (9) backwards and independently of this by pressing in the actuating pushbutton (21), and that the male clamping unit (10) is not in direct connection with the mine feed and replenishment unit (12).

2. Fine lead pencil according to claim 1, characterized in that the refill and replenishment unit (12) has inclined surfaces (50) which widen towards the front and against which spring-loaded clamping bodies (51) rest, the inclined surfaces tapering from the front (58 ) against the mine feed and replenishment unit (12) axially displaceable between stops pressure sleeve (55) can be acted on from the rear, the pressure sleeve (55) being actuated by the mine magazine (13) and the sliding part (9).

3. Fine lead pencil according to claim 1 or 2, characterized in that the clamping sleeve (27) is loaded backwards by a pressure spring (29) supported on the housing and that clamping sleeve (27) and clamping pliers (25) together with a guide bush

(26) of the clamping pliers and a compression spring (28) supported on the clamping sleeve (27) and clamping pliers (25) are mounted coaxially in the connecting sleeve (11).

4. fine lead pencil according to claim 3, characterized in that the clamping sleeve (27) and guide bushing (26) each have radially outwardly directed webs (36, 37) which are in longitudinal slots (38) of the connecting sleeve (11) and leads ge protrude the outer diameter of the connecting sleeve (11).

5. Fine lead pen according to claim 4, characterized in that with the front end of the lead magazine (13) a lead feed (17) and with this a feed sleeve (61) is connected axially against the action of a compression spring (64) displaceable feed sleeve (62) is included, the webs (36, 37) being displaceable by axial displacement of the feed sleeves (61, 62) and the displacement of the clamping sleeve (27) being limited by a shoulder (43) fixed to the housing .

OMPI

6. fine lead pencil according to claim 5, characterized in that when the actuating button (21) of the web (37) of the clamping sleeve (27) from the front edge of the feed sleeve (62) is at a distance (B) which is smaller than that Distance (C) of the web (36) of the guide bush (26) from the front edge of the feed sleeve (61).

7. fine lead pencil according to claim 5 or 6, characterized gekenn¬ characterized in that the feed sleeve (62) at a stop

(63) of the feed sleeve (61) under the pressure of the compression spring

(64) is present.

8. fine lead pencil according to one of the preceding claims, da¬ characterized in that a compression spring (16) between a stop (14) of the mine magazine (13) and a ge-fixed stop (15) is clamped.

9. fine lead pencil according to one of claims 5 to 8, characterized in that the lead feeder (17) has a stop shoulder (44) which, when the push button (21) is not pressed, rests against a stop shoulder (45) fixed to the housing.

10. Fine lead pencil according to one of the preceding claims, characterized in that the sliding part (9) is loaded by a compression spring (48) against a shoulder (49) of the tip (1).

11. Fine lead pencil according to one of the preceding claims, wherein a lead holding part is firmly inserted in the sliding part, characterized in that the lead holding part (23) has projecting resilient extensions (24) which bear against the lead (35) with friction.

12. Fine lead pencil according to one of claims 2 to 11, characterized in that the clamping body (51) are wheels, the peripheral profile of which is adapted to the shape of the lead.

- ^ ÖRE ^

OMPI

13. Fine lead pencil according to one of claims 2 to 11, characterized in that the clamping body (51) are rolling elements in the form of balls or rollers.

14. Fine lead pencil according to claim 12 or 13, characterized gekenn¬ characterized in that the clamping body (51) by a compression spring (52) loaded pressure plate (53) are held in one plane.

15. Fine lead pencil according to one of claims 2 to 11, characterized in that the Klemmkδrper (51) are designed as shaped springs, clamping rings or toothed disks.

16. Fine lead pencil according to one of claims 2 to 15, characterized in that the pressure sleeve (55) in the mine feed and replenishment unit (12) is axially displaceably mounted and held by a limit (56).

17. Fine refill pin according to claim 16, characterized in that the rear end of the pressure sleeve (55) is mounted in an axially displaceable manner with friction in a recess (59) of the lead feeder (17) and a small distance when the actuating pushbutton (21) is not pressed (D) from a shoulder (60) of the mine feed (17).

18. Fine lead pencil according to one of claims 5 to 17, characterized in that an outer sleeve of the lead feed and replenishment unit (12) and the lead feed (17) consist of magnetic material and are magnetized in opposite directions.

19. Fine lead pencil according to one of the preceding claims, characterized in that the connecting sleeve (11) has longitudinal slots (47) which engage in the radially inwardly projecting webs (46).

20. Refill pin according to claim 19, characterized in that the compression sleeve (29) loaded by the compression spring (29). (27) when the actuating pushbutton (21) is not pressed with a stop shoulder (42) against a narrowed bore (41) formed by the webs (46).

21. Fine lead pencil according to one of the preceding claims, characterized in that an externally manually rotatable switching sleeve (72) by means of switching cams (69) on a housing-fixed cam sleeve (66) by means of a compression spring (16) is held in contact, the cam sleeve (66) has a scale curve (70) with maximum points (67) and minimum points (68) as well as snap-in depressions (71) for the switching cams (69), and that a compression spring (48) loading the mine feed and replenishment unit (12) is under pressure when the switching cams (69) are arranged at the maximum points (67) and is relaxed when the switching cams (69) are arranged at the minimum points (68).

22. Fine lead pencil according to claim 21, characterized in that the rotary movement of the switching sleeve (72) is limited by the stop webs (73) of the switching curve (70).

23. Fine lead pencil according to one of the preceding claims, characterized in that between the slide (9) and the mine feed and replenishment unit (12) increases the movement of the displacement part (9) to the movement of the mine feed and replenishment unit ( 12) transmitting translation part (76,77,79) is switched on.

24. Fine refill pencil according to claim 23, characterized in that the translation part has a molded part (75) fastened to the connecting sleeve (11) with a gear wheel (7) mounted on this, which, on the one hand, is connected to the actuating pusher ( 21) fixedly connected rack (77) and on the other hand is engaged with an axially displaceable rack (79), the displaceable rack (79) being firmly connected to the refill and supply unit (12).