Abstract:
A marking implement for marking activities such as marking of a drill hole or indicating a cutting/sawing edge, and includes a marking pen having a pen housing and an application reservoir held in a axially fixed manner therein and a protective cap with an elongate interior for partially accommodating the marking pen. The marking pen has a gripping region and, adjoining it, a thinner neck region, on which a nib is formed at the free end. The cap has an interior section for partially accommodating the gripping region and a narrower interior section for accommodating the neck region. Furthermore, a fastening clip is disposed on the outer surface of the cap. The clip is integrally formed on the protective cap with a fixed end in a region adjacent to the opening and, from there, tapers substantially to the end of the cap that faces away from the opening.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Field of the Invention  
         [0002]     The invention is concerned with a marking implement, in particular, for drawing, marking, or labeling drill holes, cutting edges, layout lines, or the like.  
         [0003]     In particular, in the course of a manual activity it is customary to mark a drill hole, a cutting or sawing edge, or a desired layout line in advance on part of a structure to be created, a wall, a ceiling, or the like. A ruler, a template, or the like is usually placed onto the object to be marked as an indication for the marking that is to be provided. Use is frequently also directly made of a further part that is to be attached to or disposed on the object to be marked as a template for the first part. For example, it is customary, to provide a drill hole serving to screw together two parts, to place a first part, which is provided with a pre-manufactured hole, onto a second part, into which a hole is to be drilled, in the desired fastening position and to mark the drill hole, which is to be provided, in advance on the second part through the hole in the first part.  
         [0004]     A writing instrument, in particular a pencil, ball-point pen, or fiber-tipped pen, is used generally for such marking work. However, the provision of markings by a conventional writing instrument is frequently associated with handling difficulties. Firstly, the points that are to be marked are accessible frequently only with difficulty using a conventional writing instrument. This applies, in particular, if a marking is to be provided at the bottom of a slim and deep hole or a line is to be drawn behind a wide spacing edge. A conventional writing instrument is frequently too wide for such marking work. Secondly, a sufficiently thin writing instrument is also often not very well suited to such marking activity due to lacking robustness, and, in particular, is subject to rapid wear and a high risk of damage.  
         [0005]     A fiber-tipped pen having a pen housing and an application reservoir, which protrudes out of the pen housing and is fixed in an axially movable manner, is disclosed, for example, in German Published, Non-Prosecuted Patent Application DE 100 49 488 A1. In the case of the known pen, the application reservoir is surrounded by a small protective tube that can be pushed back axially with respect to the application reservoir in the direction of the housing with a defined force being exerted to automatically readjust the small protective tube as the application reservoir is being used up in a manner corresponding to the particular period of use. A fiber-tipped pen is always used together with a corresponding protective cap that protects the nib of the pen against drying out.  
         [0006]     Furthermore, European Patent 0 752 932 B1 discloses a writing or drawing implement having a writing instrument and a removable cap. In this case, the cap is provided with a fastening clamp, which is fixed on the open side of the cap and is orientated with its free end in the direction of the closed end of the cap.  
       SUMMARY OF THE INVENTION  
       [0007]     It is accordingly an object of the invention to provide a marking implement that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that is particularly suitable for a marking activity of the type mentioned above.  
         [0008]     With the foregoing and other objects in view, there is provided, in accordance with the invention, a marking implement, including a marking pen having a pen housing having a relatively wide gripping region and a relatively thin neck region adjoining the gripping region, the neck region having a free end side and a nib on the free end side, and an application reservoir axially fixedly held in the pen housing, a protective cap defining an elongate interior opening out at a cap opening for at least partially accommodating the marking pen therein, the cap having an outer surface and an end facing away from the cap opening, the interior of the cap having, a relatively wide interior section for at least partially accommodating the gripping region of the marking pen and a relatively narrow interior section for accommodating the neck region of the marking pen, and a fastening clip being disposed on the outer surface of the cap, being integrally formed on the cap, having a fixed end connected to the cap in a region adjacent the cap opening, a free end closer to the end of the cap facing away from the opening than the fixed end, and tapering from the fixed end towards the free end.  
         [0009]     The marking implement includes a marking pen, in particular, a fiber-tipped pen, and a protective cap for the marking pen. The marking pen includes a pen housing and an application reservoir held in an axially fixed manner in it, and is divided into a wide gripping region and an axially adjoining, thin neck region. In such a case, a nib at which the application reservoir protrudes out of the pen housing is formed on the free end of the neck region. The protective cap has an elongate interior that opens out in an opening and is provided for partially accommodating the marking pen. The interior is matched to the shape of the marking pen. The interior includes, in particular, a narrow interior section for accommodating the neck region, and a wide interior section for partially accommodating the gripping region of the marking pen. A fastening clip is, furthermore, disposed on the outer surface of the protective cap. This fastening clip is integrally formed on the protective cap in a region adjacent to the opening and, from there, tapers substantially to the end of the protective cap that faces away from the opening.  
         [0010]     The above-described marking implement considerably simplifies marking and drawing work. As a result of its comparatively wide gripping region, the marking pen is, thus, stable and ergonomic, in particular, it can readily be grasped. On the other hand, the thin neck region of the marking pen makes it possible to provide a marking even at a point to which access is difficult, through a comparatively deep and narrow hole, or behind a wide spacing edge.  
         [0011]     The marking pen is not only effectively protected against drying out by matching the protective cap to the shape of the marking pen and, in particular, when the marking pen is inserted, by it accommodating not only the neck region thereof, but also part of the gripping region. On the contrary, the protective cap, thereby, also effectively protects the thin and, therefore, comparatively sensitive neck region of the marking pen against damage.  
         [0012]     In accordance with another feature of the invention, a particular simplification of the handling is obtained by providing the fastening clip according to the invention. This, namely, permits the protective cap to be fastened in the manner of a quiver with the opening upward to a pocket of the work clothes or the like, and therefore, in particular, to the body. Such a configuration enables the marking pen to be pulled in a simple manner, in particular, one-handed, out of the protective cap and to be inserted back after use into the protective cap (which is still fastened to the work clothes or the like). The effect achieved thereby is that the marking pen can be grasped at any time, but, on the other hand, for the period when it is not in use is well protected at all times against damage, drying out, etc. The possibility of fastening the marking implement on the body and the simple, one-handed usability are of particular importance during a marking activity, particularly because, here, as a rule, one hand is required for placing on and holding a ruler, a template, or a part used as a template, and there is not generally a secure possibility of depositing the marking pen within reach.  
         [0013]     In accordance with a further feature of the invention, to prevent the protective cap from becoming detached inadvertently from the pocket or the like to which it is fastened, when the marking pen is pulled out, at least one blocking element is formed on the inner surface of the fastening clip, the blocking element “clawing” against the material, the pocket or the like, in the manner of a barb and, therefore, counteracting an inadvertent pulling out of the protective cap. The or each blocking element is, preferably, in turn configured in the form of a resilient clip that is integrally formed on one side of the fastening clip. In such a form, the blocking element includes a retaining limb, with which it is integrally formed on the inner surface of the fastening clip, and a free limb that is angled away from this retaining limb. In such a case, the retaining limb protrudes from the inner surface of the fastening clip obliquely in the direction of the fixed end of the fastening clip while the free limb, in turn, is orientated obliquely in the direction of the inner surface of the fastening clip.  
         [0014]     In accordance with an added feature of the invention, to hold the or each blocking element in a stable manner on the fastening clip, on one hand, and in order to ensure good spring elasticity of the blocking element, on the other hand, the retaining limb is expediently configured such that it tapers from the inner surface of the fastening clip in the direction of the free limb. The formation of the free limb of the or each blocking element as a supporting plate enables, on one hand, a good retaining action of the or each blocking element to be achieved, but, on the other hand, effectively prevents the work clothes or the like, to which the protective cap is fastened, from being damaged, in particular, torn, by the blocking element.  
         [0015]     In accordance with an additional feature of the invention, the retaining limb tapers outwardly from the inner surface of the fastening clip in a direction of the free limb.  
         [0016]     In accordance with yet another feature of the invention, there is provided a sealing bead on the inner surface of the protective cap. By the bead, the marking pen, in the state in which it is inserted into the protective cap, is effectively protected against drying out. This protective effect is assisted, in particular, by configuring the sealing bead to surround the marking pen in its neck region in a sealing manner. The configuration namely keeps the interior volume of the protective cap surrounding the nib of the marking pen particularly small, as a result of which, the evaporation of the solvent of the pen ink is minimized.  
         [0017]     In accordance with yet a further feature of the invention, there is preferably provided a step-like shoulder between the gripping region and the neck region of the marking pen, which serves, in interaction with a stop provided in the interior of the protective cap, to limit the introducing distance of the marking pen into the protective cap in a well-defined insertion position.  
         [0018]     In accordance with yet an added feature of the invention, the outside diameter of the gripping region of the marking pen, on one hand, and the inside diameter of the wide interior section of the protective cap, on the other hand, are, preferably, matched to each other such that, when the marking pen is inserted into the protective cap, an annular gap is formed between the latter and the protective cap. Such a configuration effectively avoids the protective casing becoming soiled by particles of dust or the like adhering to the marking pen or the marking pen even becoming jammed in the protective casing. For such a purpose, the radial thickness of the annular gap is at least 0.2 mm. The radial thickness of the annular gap, preferably, lies in a range between 0.3 mm and 0.5 mm, in particular, at approximately 0.35 mm. In such a case, the marking pen is, preferably, held coaxially with the protective cap by a centering projection or a plurality of interacting centering projections that, when the marking pen is inserted, bears/bear against the outer circumference of the gripping region. The centering projection or the centering projections is/are, preferably, dimensioned such that it/they acts/act radially on the inserted marking pen in the gripping region and, therefore, retain it captively in the protective cap.  
         [0019]     In accordance with yet an additional feature of the invention, the application reservoir is fluidically connected to the nib.  
         [0020]     In accordance with again another feature of the invention, the application reservoir of the marking pen is surrounded in the region of the nib by a small protective tube that can be displaced back axially with respect to the application reservoir in the direction of the pen housing with a defined force being exerted. The small protective tube stabilizes the application reservoir in a particularly effective manner so that even rough surfaces that greatly stress the application reservoir in the region of the nib can be written on without the application reservoir being damaged, in particular, “frayed”, in the region of the nib. The ability of the small protective tube to be displaced back has the effect, on the other hand, that, as the application reservoir continues to be used up, the small protective tube is successively and automatically readjusted so that a writing performance that always remains the same is provided regardless of the degree to which the application reservoir is used up. The defined push-back force for the small protective tube is set, in particular, by the inside diameter of the small protective tube being matched, taking into consideration a frictional fit tolerance, to the diameter of the application reservoir. In such a case, the frictional fit tolerance determines the defined push-back force.  
         [0021]     To limit the push-back distance of the small protective tube with respect to the application reservoir and thereby, in particular, to specify a defined minimum length of the marking pen, in accordance with again a further feature of the invention, a stop, which is fixed on the housing, is provided for the small protective tube. This stop is, expediently, formed on the pen housing or on a part connected fixedly thereto. The application reservoir is, preferably, additionally stabilized in the region of the nib by a guide section, which is formed in the region of the nib in the pen housing, in particular, a guide hole, for the small protective tube.  
         [0022]     In accordance with again an added feature of the invention, the application reservoir includes two axially adjoining reservoir sections of different diameter. In such a case, a first, in particular, thinner, reservoir section is disposed in the region of the nib and is surrounded by a small protective tube that has an inside diameter matched, taking a frictional fit tolerance into consideration, to the diameter of this first reservoir section. A second reservoir section is disposed on the housing with respect to the first reservoir section. In this variant, the second reservoir section expediently forms a stop limiting the push-back distance of the small protective tube.  
         [0023]     The effect firstly achieved by providing that end of the small protective tube that is on the housing with an overhang is that the small protective tube is supported, in an entirely pulled-back position, flat against a housing stop or, if appropriate, against the wide reservoir section acting as a stop. As a result, a possible overcoming of the stop by exerting force on the small protective tube is made more difficult. Secondly, the overhang prevents the small protective tube from being able to be pulled off from the application reservoir in the direction of the nib. The overhang is configured such that it is either rotationally symmetrical with respect to the axis of the small protective tube or is formed by one or more tabs bent out of the circumferential surface of the small protective tube.  
         [0024]     In accordance with again an additional feature of the invention, to ensure a secure grip of the marking pen in the protective cap, provision is, preferably, made for at least one third, preferably, approximately 50% to 60%, of the axial length of the gripping region of the pen housing to be accommodated, in the inserted state, within the protective cap.  
         [0025]     In accordance with still another feature of the invention, the end of the marking pin that faces away from the nib bears a sealing sleeve of elastic material, in particular, rubber or plastic, which is pushed onto the gripping region and the edge of the sealing sleeve that faces the nib is configured to form a sealing lip. The sealing sleeve, and, in particular, its sealing lip, are constructed such that the sealing lip, when the marking pen is inserted into the protective cap, closes the opening of the protective cap in a dustproof and, preferably, also sprayproof manner so that a penetration of dust or spray into the protective cap is avoided at least when the marking pen is inserted. The sealing sleeve advantageously results in a further simplification of the handling by the end of the sealing sleeve that faces away from the nib being widened to form a wide and, therefore, particularly ergonomic supporting bulge.  
         [0026]     In accordance with still a further feature of the invention, the marking pen has a longitudinal end facing away from the nib, a sealing sleeve of elastic material is pushed onto the longitudinal end and has an edge facing the nib, and the edge of the sealing sleeve facing the nib forms a sealing lip sealing the cap opening when the marking pen is inserted into the cap.  
         [0027]     In accordance with still an added feature of the invention, the marking pen has a longitudinal end facing away from the nib and a sealing sleeve of elastic material at the longitudinal end, the sealing sleeve having an edge facing the nib and the edge of the sealing sleeve facing the nib forms a sealing lip sealing the cap opening when the marking pen is inserted fully into the cap.  
         [0028]     In accordance with a concomitant feature of the invention, the sealing sleeve has an end facing away from the nib and the end of the sealing sleeve facing away from the nib is widened to form a supporting bulge.  
         [0029]     Other features that are considered as characteristic for the invention are set forth in the appended claims.  
         [0030]     Although the invention is illustrated and described herein as embodied in a marking implement, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.  
         [0031]     The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0032]      FIG. 1A  is a side elevational view of a marking pen of a marking implement according to the invention;  
         [0033]      FIG. 1B  is a longitudinal cross-sectional and partially perspective view of a protective cap for the marking pen of the marking implement of  FIG. 1A  along section line IB-IB in  FIG. 2 ;  
         [0034]      FIG. 2  is a cross-sectional view of the protective cap of  FIG. 1B  along section line II-II in  FIG. 1B ;  
         [0035]      FIG. 3  is a fragmentary, enlarged, cross-sectional view of a blocking element of the fastening clip of  FIG. 1B ;  
         [0036]      FIG. 4  is a partially cross-sectional and partially side elevational view of the protective cap of  FIG. 1B  with the marking pin of  FIG. 1A  inserted therein;  
         [0037]      FIG. 5  is a fragmentary, partially cut-away side elevational view of the marking pin of  FIG. 1 ;  
         [0038]      FIG. 6  is a fragmentary, enlarged, cross-sectional view of a protective tube of the marking pen of  FIG. 1A ;  
         [0039]      FIG. 7  is a plan view of the protective tube of  FIG. 6  from the direction VII in  FIG. 6 ;  
         [0040]      FIG. 8  is a plan view of an alternative embodiment of the protective tube of  FIG. 6  from the direction VII in  FIG. 6 ;  
         [0041]      FIG. 9  is a side elevational view of an alternative embodiment of the marking pen of  FIG. 1A ;  
         [0042]      FIG. 10  is a partially longitudinal cross-sectional and partially side elevational view of the pen of  FIG. 9  in the protective cap of  FIG. 1B ;  
         [0043]      FIG. 11  is a fragmentary, longitudinal cross-sectional view of the marking pen of  FIG. 9 ;  
         [0044]      FIG. 12  is a side elevational view of another embodiment of the marking implement according to the invention with a protective cap and a marking pen inserted therein and with a sealing sleeve in a sealing postion where the opening of the protective cap is sealed to the marking pen; and  
         [0045]      FIG. 13  is a side elevational view of the marking implement of  FIG. 12  with the sealing sleeve in a non-sealing postion where the marking pen is slightly out of the cap and the opening of the protective cap is not sealed to the marking pen.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0046]     Mutually corresponding parts and sizes are always provided with the same reference numbers in all of the drawings.  
         [0047]     Referring now to the figures of the drawings in detail and first, particularly to  FIG. 1  thereof, there is shown a marking implement  1  including a marking pen  2  (illustrated in  FIG. 1A ) and a protective cap  3  (illustrated in  FIG. 1B ) into which the marking pen  2  can be inserted. The marking pen  2  is configured as a permanent marker and includes a pen housing  4  that is, preferably, of plastic. The marking pen  2  furthermore includes an application reservoir  5  of a fiber material, which is accommodated in a fixed position in the pen housing  4  and protrudes out of the pen housing  4  at a nib  6  of the marking pen  2 .  
         [0048]     The marking pen  2  is divided into a comparatively wide and substantially cylindrical gripping region  7  that faces away from the nib  6  and is formed by the pen housing  4 . This gripping region  7  is adjoined axially with respect to a pen axis  8  by a comparatively thin neck region  9  that bears the nib  6  on the free end side. The neck region  9  is formed by a conical housing section  10  and an approximately cylindrical bearing section  11  of the pen housing  4 , which section  11  adjoins the housing section  10  in the direction of the nib  6 .  
         [0049]     In the direction of the nib  6 , the pen housing  4  is extended by a thin small protective tube  12 , preferably, of metal, which surrounds the application reservoir  5 . The axial length of the neck region  9 , including the housing section  10 , the bearing section  11 , and the small protective tube  12 , is, preferably, at least 25%, in particular, approximately one-third of the axial length of the marking pen  2 . A step-shaped shoulder  13  is formed on the pen housing  4 , between the neck region  9  and the gripping region  7 .  
         [0050]     The protective cap  3 , which, likewise, preferably is of plastic, encloses an elongate interior  14  that opens out in an opening  16  at one longitudinal end  15 . The interior  14  has a shaping matched to the shape of the marking pen  2  and, to this extent, includes a narrow interior section  17  for accommodating the neck region  9  of the marking pen  2 , which region extends in a transition region  18  in the direction of the opening  16  to form a wide interior section  19 . The latter is provided for partially accommodating the gripping region  7  of the marking pen  2 . Between the narrow interior section  17  and the transition region  18 , an annular sealing bead  20  narrows the interior  14 . The interior  14  is formed substantially rotationally symmetrically with respect to a cap axis  21 . The protective cap  3  has an outer surface  22 , which substantially corresponds to the shape of the interior  14  and continuously expands, in particular, in a section corresponding to the transition region  18 .  
         [0051]     The protective cap  3  furthermore includes an elastically deflectable fastening clip  23  that is curved approximately in an S shape. The fastening clip  23  is integrally formed on the outer surface  22  with a fixed end  24  in a region of the protective cap  3  that is adjacent to the opening  16 , and runs from there along the protective cap  3  approximately parallel to the cap axis  21  at a certain distance from the outer surface  22  so that that free end  25  of the fastening clip  23  that faces away from the fixed end  24  faces away from the open longitudinal end  15  of the protective cap  3  and faces the opposite, closed longitudinal end  26  of the protective cap  3 .  
         [0052]     On an inner surface  27  of the fastening clip  23 , which surface faces the outer surface  22  of the protective cap  3 , the fastening clip  23  bears two blocking elements  28  that are offset axially with respect to each other. In the region of the free end  25 , the inner surface  27  is, furthermore, provided with a retaining projection  29  whose tip bears substantially against the outer surface  22 .  
         [0053]     The fastening clip  23  serves to fasten the protective cap  3  to a flat object, in particular, to a pocket of work clothes or the like. In such a case, the blocking elements  28 , which are described in greater detail below, provide, in particular, if the protective cap is fastened to a soft, flexible material, such as, for example, cloth, a particularly good retention, in the manner of barbs, which counteracts the protective cap  3  being pulled out of the pocket or the like. The retaining projection  29  is effective, in particular, if the protective cap  3  is fastened to a comparatively flat object, for example, a piece of paper or cardboard.  
         [0054]     As is apparent, in particular, from  FIGS. 2 and 3 , each blocking element  28  is in the form of a two-limbed spring clip. Each blocking element  28  is fixed to the inner surface  27  of the fastening clip  23  by a retaining limb  30 , the retaining limb  30  extending from the inner surface  27  obliquely in the direction of the opening  16 , and, therefore, also in the direction of the fixed end  24 , and tapering increasingly with increasing distance from the inner surface  27 . A knee  31 , at which the retaining limb  30  merges into a free limb  32 , is formed at that end of the retaining limb  30  that faces away from the inner surface  27 . The free limb  32  is angled away from the retaining limb  30 , preferably, by an angle of between 60° and 100° so that its free end  33  is, in turn, orientated obliquely in the direction of the inner surface  27 . As emerges, in particular, from  FIG. 2 , the free limb  32  is configured to perform a comparatively wide supporting surface  34  that provides particularly good resistance to the cloth of a pocket or some other soft object, to which the protective cap  3  is fastened, without, in the process, damaging or even tearing the cloth or object.  
         [0055]     As can be seen, in particular, in an overall view of  FIGS. 1B and 2 , three projection-like stops  39  are provided in the interior  14  of the protective cap  3  and interact with the shoulder  13  of the marking pen  2  to limit the introducing distance of the marking pen  2  into the protective cap  3  in a defined manner. In such a case, the stops  39  are offset in each case by an angle of 120° with respect to one another about the circumference of the protective cap  3 . Furthermore, three centering projections  35  are disposed offset in alternating fashion in respect to the stops  39  in the interior  14 . These centering projections  35  serve to center the marking pen  2  with respect to the protective cap  3  in the state in which it is inserted into the protective cap  3 , so that the pen axis  8  coincides with the cap axis  21 .  
         [0056]     This insertion position of the marking pen  2  in the protective cap  3  is illustrated in  FIG. 4 , in which it can be seen, in particular, that the centering projections  35  engage in the gripping region  7  of the marking pen  2  on the outer circumference thereof. In such a case, the centering projections  35  are dimensioned such that they act radially with a predetermined retaining force on the gripping region  7  so that the marking pen  2  is retained captively in the protective cap  3 . It is, furthermore, clear from the illustration according to  FIG. 4  that the outside diameter of the marking pen  2  in the gripping region  7  thereof is selected in relation to the inside diameter of the protective casing  3  in the corresponding, wide interior section  19  such that, in the inserted state, an annular gap  36  is formed between the gripping region  7  of the marking pen  2  and the protective casing  3 , the radial thickness of which gap is approximately 0.35 mm. The centering projections  35  in this case ensure that the thickness of the annular gap  36  is substantially constant around the circumference of the marking pen  2 , and that, in particular, the marking pen  2  does not, therefore, bear against the interior wall of the protective cap  3 . The annular gap  36  prevents the marking pen  2  from jamming in the protective cap  3  because of small particles of dust or the like that adhere to the gripping region  7 . In addition, the substantially contactless mounting of the marking pen  2  in the protective cap  3  avoids dust or other contaminants being rubbed off from the gripping region  7  of the marking pen  2  onto the interior wall of the protective cap  3 , which would gradually soil the protective cap  3  under dirty environmental conditions.  
         [0057]     The insertion position of the pen  2  with respect to the protective cap  3 , which position is illustrated in  FIG. 4 , is defined, in particular, by the shoulder  13  of the pen housing  4  striking against the corresponding stops  39  of the protective cap  3 . At the same time, in the inserted position, the sealing bead  20  bears circumferentially against the bearing section  11  of the pen housing  4 . As a result, the narrow interior section  17  with the nib  6  of the marking pen  2  enclosed in it is sealed off in an airtight manner with respect to the environment. The marking pen  2  is, thereby, protected against drying out.  
         [0058]      FIG. 5  shows, on an enlarged scale, a front section of the marking pen  2  in a longitudinal section, embodied in half a side, along the pen axis  8 . In  FIG. 5 , it can be seen, in particular, that the pen housing  4  contains a store or reservoir  40  for a liquid application medium. In such a case, the application medium used is, in particular, liquid ink based on alcohol as the solvent. An application medium of this type has the advantage, in particular, that it can be applied on virtually any desired surfaces, in particular, plastic, metal, stone, wood, or glass. It is, therefore, particularly suitable for marking operations in the trade sphere.  
         [0059]     The application reservoir  5 , which is illustrated in detail in  FIG. 5 , has a constant diameter over its entire length. The application reservoir  5  bears with a rear end section  41  against a stop  42  that is formed by the base  43  of a sleeve  44 . On its encircling collar  45  that protrudes away from the base  43 , the sleeve  44  is provided with a number of holes  46  through which the store  40  is connected fluidically to the application reservoir  5 . The sleeve  44  is fixed in the pen housing  4  by the collar  45 .  
         [0060]     To ensure a writing performance that remains the same regardless of the degree to which the application reservoir  5  is used up, the small protective tube  12  is guided such that it can be displaced back axially from the position illustrated in  FIG. 5  by a push-back distance  47  in relation to the pen housing  4  and the application reservoir  5 , which is in a fixed position with the pen housing  4 . In such a case, the inside diameter of the small protective tube  12  and the outside diameter of the application reservoir  5  are coordinated with each other such that the small protective tube  12  surrounds the application reservoir  5  with a predetermined frictional fit tolerance. The fit enables the small protective tube  12  to be displaced back on the application reservoir  5  with a force that is predetermined by the frictional fit tolerance. This force is dimensioned such that, in the course of the use of the marking pen  2 , the small protective tube  12  is gradually set back automatically as the application reservoir  5  is increasingly used up. To guide the small protective tube  12 , a hole is formed on the pen housing  4  as a guide section  48  for this purpose. The push-back distance  47  of the small protective tube  12  is limited toward the side facing away from the nib  6  by a stop  49  that is fixed on the housing and is formed by the edge of the collar  45 . A second stop  50 , which limits the push-back distance  47  toward the side facing the nib  6 , prevents the small protective tube  12  from being able to be pulled off over the nib  6 . In such a case, the stop  50  interacts with an overhang  51  of the small protective tube  12 , which overhang is disposed on the housing side and is illustrated on an enlarged scale in  FIGS. 6 and 7 . The overhang  51  is, preferably, configured, according to  FIGS. 6 and 7 , as an annular expansion of that edge of the small protective tube  12  that is on the housing side. As an alternative, the overhang  51  may, in accordance with  FIG. 8 , also be formed by one or more tabs  52  that are formed on that edge of the small protective tube  12  that is on the housing side and that are bent away approximately radially outward from the pen axis  8 .  
         [0061]      FIG. 9  illustrates an alternative embodiment of the marking pen  2 , which is provided especially for a particularly fine nib  6 . In this embodiment, the marking pen  2  includes a pen housing  4  that is configured identically to the pen housing  4  of the previously described variant in  FIG. 1A . However, instead of the small protective tube  12 , an extension tube  53  is inserted into the pen housing  4 . The outside diameter of the extension tube  53  is dimensioned, in particular, such that the extension tube  53  is connected to the pen housing  4  in a fixed position with a press fit. At an end facing the nib  6 , the extension tube  53  bears a conical guide element  54  for a small protective tube  12 , the guide element  54  having a comparatively small outside diameter that is matched to the diameter of the application reservoir  5 .  
         [0062]     In the same manner as the variant of the marking pen according to  FIG. 1A , the second embodiment of the marking pen  2  that is illustrated in  FIG. 9  can be inserted, as illustrated in  FIG. 10 , into the protective cap  3 .  
         [0063]      FIG. 11  illustrates a front section of the embodiment of the marking pen  2  according to  FIG. 9  in a longitudinal section. The illustration of  FIG. 11  shows that the application reservoir  5  is divided here into a first reservoir section  55  and a second reservoir section  56 . The first reservoir section  55  is disposed in a region adjacent to the nib  6  and has a comparatively small diameter substantially corresponding to the inside diameter of the small protective tube  12 . The second reservoir section  56  is disposed within the extension tube  53  and, therefore, on the housing side with respect to the first reservoir section  55 , and completely fills the extension tube  53 . Thereby, the second reservoir section  56  is, in particular, widened in relation to the first reservoir section  55 .  
         [0064]     Also in the case of the embodiment of the marking pen  2  according to  FIG. 9 , the small protective tube  12  can be displaced back axially in relation to the pen housing  4  including the extension tube  53  and in relation to the application reservoir  5 , which is in a fixed position with the pen housing  4 . In such a case, a central hole of the guide element  54  acts as the guide section  48 . The stop  49  on the housing side that limits the push-back distance  47  of the small protective tube  12 , is formed, according to  FIG. 11 , by the edge of the wide reservoir section  56 . In such a case, the overhang  51  of the small protective tube  12  acts as a supporting surface that prevents the small protective tube  12  from being pressed beyond the stop  49  into the wide second reservoir section  56 .  
         [0065]      FIGS. 12 and 13  show a variant of the marking implement  1 , in which a sealing sleeve  58  is pushed, in particular, pressed, onto the longitudinal end  57  of the marking pen  2  that faces away from the nib  6 . In such a case, the sealing sleeve  58  is of a flexible plastic or rubber.  
         [0066]     A sealing lip  59  is formed on an edge of the sealing sleeve  58  that faces the nib  6 . The sealing sleeve  58  and, in particular, the sealing lip  59  thereof, are dimensioned such that, in the inserted position of the marking pen  2  in the protective cap  3  illustrated in  FIG. 12 , the sealing lip  59  rests under pre-stress on the edge of the opening  16  so that, when the marking pen  2  is inserted into the protective cap  3  (as shown in  FIG. 12 ), the opening  16  is sealed off against the penetration of dust and spray. The end of the sealing sleeve  58  that faces the longitudinal end  57  of the marking pen  2  is, preferably, widened to form a supporting bulge  60  or supporting head, which improves the ergonomics and, therefore, the handling ability of the marking pen  2 .