EP1800895B1 - Pencil sharpener and method for manufacturing the same - Google Patents

Description

The invention relates to a pencil sharpener for sharpening a writing, painting or cosmetic pencil.

Conventional pencil sharpeners typically include a sharpener body into which a tapered pin guide channel is inserted. A laterally arranged on the pin guide channel paring knife carries from a rotating in the pin guide channel pin material, resulting in a sharpening of the pin. For catching Spitzabfall further container sharpener are known in which a tip insert with pin guide channel and paring knife a container is detachably mounted. By loosening the tip insert from the container it can be emptied.

For example, is from the GB 359,555A a container sharpener is known whose cylindrical container is adapted to the size of a human hand.

Next diverse utensils are known, are integrated in the lace inserts to ensure the possibility of sharpening when using the respective commodity. So is out of the GB 2 316 315A a finger positioning device is known, which positions the fingers of a human hand for the purpose of manicure when grasping. At the lower end of the finger positioning device, a tip insert is provided, which allows the tips of cosmetic pencils. Next is from the GB 2 308 328A a saw known in the handle of a tip insert is integrated.

To tip a pin in the manner described, some torque must be applied by a user to turn the pin to be sharpened against the peeling knife.

The invention has for its object to provide a pencil sharpener with improved handling. It is a further object of the invention to provide a method of manufacturing such an improved pen nib.

The first object is achieved according to the invention by a pencil sharpener comprising a handle with a central longitudinal axis and a tip insert inserted into the handle along the longitudinal axis with a pin guide channel and a paring knife, wherein the handle comprises a grasped by a human hand with thumb and forefinger base in which a thumb rest groove partially encircling the longitudinal axis and its at least one finger rest groove partially revolving around the longitudinal axis are formed.

The invention is based on the consideration that the manageability of a pen tip can be improved by improving the coupling of the pen tip to the human user. For this purpose, the tip insert along the longitudinal axis is introduced into a handle that can be well grasped as such by a human hand. The human-tool interface is further improved by the fact that the handle is at least partially formed on the inner contours of a curved human hand. In other words, the handle has at least partial areas, which are designed to be complementary to the inside of a curved human hand substantially. For this purpose, the handle comprises a base that can be grasped by the human hand with the thumb and forefinger, wherein the base is formed with a thumb rest groove partially encircling the longitudinal axis and with a finger rest groove extending at least partially opposite the longitudinal axis. Since the human hand is formed as a gripping hand, with the thumb opposite to the other fingers, thereby the handle between the thumb and at least one of the remaining fingers is kept good and strong. For this purpose, it is sufficient if the handle extends along the longitudinal axis in the most minimal case over a distance of the dimension of about a finger thickness. In this case, the handle of the pen nib would have a flat base with an approximately oval cross-section have, at the edge opposite the thumb rest groove and the finger rest groove are formed.

Due to the ergonomic design of the pencil sharpener by a handle which is formed in partial areas of the inner surfaces of a curved human hand, an improved power transmission is achieved by the user. Compared to conventional pencil sharpeners, a smaller force input is required to achieve the torque required for the sharpening process. In addition, the force entry deteriorating positions of the pen tip are prevented. The attitude is dictated by the Anformung to the human hand. Bad postures are avoided. The ergonomic design of the pencil sharpener makes it possible in particular children or users with limited manual skills to perform the sharpening process easily and easily. As a side effect of the pencil sharpener is also taken with a handle designed in this way and because of the ease of the pointed process like to hand. Especially children are therefore animated to more frequent tips.

The handle can in principle be formed in different parts of the curved human hand. An Anformung is particularly useful pressure points on which the human hand exerts pressure when grasping an object on this. This can be, for example, the palms or individual finger surfaces as such. If the surfaces of the handle are formed in the vicinity of the pressure grip points of the inner contour of a human hand, so the pencil sharpener is as such good in the hand and is easy to use.

In an advantageous embodiment of the invention, the handle is extended in the direction of the longitudinal axis, so that the base of the thumb rest groove opposite a plurality of parallel Fingerauflagerillen can be formed. Here, the base is formed at the point at which the Fingerauflagerillen are formed, the inner contour of the human hand, characterized in that the Finger rest grooves are separated from each other by intermediate webs. In this way, the handle fits into the surrounding this hand.

In a further advantageous embodiment of the invention, the handle is substantially formed by the body formed by the interior of a curved human hand. For this purpose, the base around the longitudinal axis substantially of a first, a second, a third and a fourth wall surface to rotate, wherein the wall surfaces are soft in the circumferential direction formed merge into one another. Each of the four wall surfaces has a specific area characteristic. The surface characteristic, ie the position and shape of the surface in three-dimensional space, for example, vary from wall surface to wall surface in the curvature both in the direction of the longitudinal axis and in the circumferential direction, as well as in introduced surface structures, such as Fingerauflagerillen, in particular corresponds to the first wall surface of a Thumb rest surface in which the thumb rest grooves are inserted. The second wall surface corresponds to a thumb ball support surface and lies with an enclosed base of the thumb ball and possibly a part of the metacarpal of the human hand. The third wall surface forms a finger support surface, in which in particular the finger support grooves are formed. The fourth wall surface is formed as a peripheral end surface whose dimension is determined by the circumference of the base. If the base can be completely encompassed by a human hand, then the fourth wall surface can only be designed to form the transition between the first and third wall surfaces. If the base is dimensioned such that it can not be completely encompassed by a human hand, then the fourth wall surface corresponds to the open part of the base which lies between the thumb and forefinger of the human hand and which is not engaged.

To support the thumb bale, the second wall surface or the surface of the thumb ball is saddle-shaped. For this purpose, the thumb ball support surface in the direction of the longitudinal axis has a concave and in the circumferential direction a convex curvature.

In an advantageous embodiment, the first wall surface or thumb rest surface is also saddle-shaped. This creates a concave curvature of the thumb rest surface in the longitudinal direction through the introduced thumb rest groove. The curvature of the thumb rest surface in the circumferential direction is convex with a small curvature to flat.

In an advantageous development of the invention, the third wall surface or finger support surface has a substantially arcuate cross section with a vertex transversely to the longitudinal axis. In this case, the or each finger support groove is formed at the vertex, so that the vertex line running parallel to the longitudinal axis on the wall surface has a wavy course. The remaining surface area of the third wall surface is essentially smooth. In this embodiment, the finger support grooves with the intermediate webs form the bearing surface for the finger area of the back finger bones. These stand opposite the thumb in the case of a loosely curved human hand. In other words, by such a base of the handle for a loosely enclosing hand pressure grip points formed in the area of the rear finger bones, whereby an ideal force input can be made for the purpose of sharpening. The handle is in this way ergonomically in a loosely curved human hand. Due to the fact that the finger rest grooves are arranged substantially in the region of the apex line of the third wall surface, a malposition of the pen nibbler is reliably avoided.

As stated, the fourth wall surface serves as a peripheral end surface. While first, second and third wall surface are formed with appropriate dimensioning of the base of the handle the inner sides of a human hand, the design of the fourth wall surface remains open. Depending on whether the first, second and third wall surface are arranged in the circumferential direction in a clockwise or counterclockwise direction, a pencil sharpener is created for left-handed or right-handed people.

If the fourth wall surface is shaped similar to the second wall surface, a uniform design of the handle is advantageously possible both for left-handed and for right-handed users. In this case, the fourth wall surface for a left hand forms a peripheral end surface that is not gripped by the hand. The second wall surface is hereby shaped as the thumb ball support surface. For a right hand, the fourth wall surface but at the same time forms a thumb ball support surface and is formed, for example saddle-shaped. The second wall surface then has the function of the peripheral end surface and is not encompassed by the human hand. By the specified embodiment of the handle, it is thus possible to provide a unified pen sharpener, which has an ergonomically designed handle for both left and right handed.

Conveniently, the base of the handle is integrally formed on the longitudinal axis a vertical, overhanging upper plateau surface. This ensures that the expended against the hand in the direction of the longitudinal axis of the pressure does not lead to slipping of the handle in the hand. This is safely prevented by the overhanging upper plateau surface, as it rests on umgriffener base of the curved human hand.

Appropriately, the overhanging part of the upper plateau surface finger recesses are molded for support on the thumb and forefinger. As a result, individual pressure points on the human hand are prevented, which would be uncomfortable for the user in the execution of the sharpening process. This also leads to an improvement of the interface between human hand and tool.

To set up the pen tip, it is advantageous if the base is formed a perpendicular to the longitudinal axis extending flat lower bearing surface. If the lower bearing surface consists of two mutually tilted flat surfaces, this can save material of the handle. At the same time, this embodiment allows a parking of the pen tip in two possible positions. Also, a free, not guided in a finger rest groove fingers of the inclined surface can be placed comfortably.

Advantageously, the tip insert is inserted approximately centrally parallel to the longitudinal axis in the base. As a result, an ideal force entry is achieved by the human hand in the pen sharpener for applying the torque required for the sharpening process.

In further advantageous embodiments of the invention, the tip insert is inserted into a bore for receiving Spitzabfall. To remove the spike, either the tip insert may be releasably inserted, or the bore passes through the base in full length so that the tip insert opposite to the bottom of the base a lid for emptying the bore can be attached.

In a further advantageous embodiment, the handle comprises materials of different elasticity. Thus, the handle may have a material of high elasticity and otherwise a material of lower elasticity at the points of the hand pressure points. The softer, higher elastic material in this case gives the hand pressure points, while the harder material of lower elasticity controls the predetermined handle loading. As a result, an optimal gripping position can be specified.

The second object is achieved by a method for producing a pen tip, wherein a substantially cylindrical body is provided in about the dimension of a human hand of a moldable mass with a space for the tip insert space, aligned along the cylinder axis placeholder, wherein the body is manually firmly embraced, whereby the body is at least a part of the inner contours of a human hand is formed, the molded body is optionally used with removed placeholder either as a raw template, with the help of a shaping processing technology in particular a casting, pouring, spraying -, turning, milling or laser machining technology, the handle is made, or the molded body is cured to the handle, wherein the placeholder is optionally taken before or after curing and wherein in the resulting by the placeholder Opening a tip insert is inserted.

By this manufacturing method, it is possible in a simple manner to provide a pencil sharpener having a handle which is partially formed on the inner contours of a curved human hand. The handle is created in a sense as an imprint of the human hand. For this purpose, it is possible in a known manner to use the impression of the human hand as a basic or raw form for other common manufacturing technologies. In particular, a negative or casting mold can be produced from the raw form, by means of which, for example, by means of plastic injection molding, the handle for the pencil sharpener can be produced. In this variant, the once created impression of the human hand is used as a template for a serial manufacturable pen sharpener.

Alternatively, it is also possible to make each one of the pen sharpeners by grasping the body by the later user himself, by the human hand, thereby molding his own hand into the handle of the pen nib. Curing the molded base of the handle creates a user-friendly pencil sharpener that fits perfectly in your own hand.

For curing the molded body, this advantageously comprises a plasticine made of a duroplastic, which can be molded in a soft form, the human hand. Subsequently, the body is cured, for example by a temperature treatment, which may optionally be carried out in a domestic oven. The personal pencil sharpener lies perfectly in the user's hand, resulting in a good force input to achieve the torque required for the sharpening process. In particular, children are thereby animated too frequent tips.

In a further advantageous embodiment, materials of different plasticity are used for the moldable mass. By a predetermined distribution of materials of different plasticity in the cylindrical body a certain influence on the shape can be achieved. In particular, the use of a material of high plasticity and a material of lesser plasticity allows to achieve certain points with high ductility, while other places are more likely to retain the original shape. For example, if the material of high plasticity on the outside of the cylindrical body and the material of lesser plasticity in the interior of the cylindrical body used, the softer material yields in the shaping by the human hand to the hand pressure points, while the harder material controls the handle molding as such.

In the production of the pencil sharpener, in particular those materials can be used which have a different elasticity in the final state.

Fig. 1 bis 4

in einer dreidimensionalen Darstellung jeweils einen Stiftspitzer mit einem teilweise den Innenkonturen einer gekrümmten menschlichen Hand angeformten Handgriff (aus verschiedenen Blickrichtungen),

Fig. 5

schematisch den Stiftspitzer gemäß den Fig. 1 bis 4, wie er von einem menschlichen Hand umgriffen wird, und

Fig. 6

in einem Längsschnitt den in den Stiftspitzer integrierten Spitzeinsatz mit einer Bohrung zur Aufnahme von Spitzabfall.

Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

Fig. 1 to 4

in a three-dimensional representation in each case a pencil sharpener with a part of the inner contours of a curved human hand molded handle (from different directions),

Fig. 5

schematically the pencil sharpener according to Fig. 1 to 4 as it is enveloped by a human hand, and

Fig. 6

in a longitudinal section of the integrated into the pen sharpener tip with a hole for receiving Spitzabfall.

In the Fig. 1 to 4 is shown from different points of view in three-dimensional representation of a pencil sharpener 1, which comprises an ergonomic handle 3 and a tip insert 4 inserted into the handle 3. The tip insert 4 is here inserted centrally substantially along the longitudinal axis of the handle 3. Also shown is a pin 6, as it is used for tips in the pin guide channel of the tip insert 4. At the same time, the pin 6 defines the longitudinal axis of the handle 3 or its base which can be grasped by the hand.

The base running along the longitudinal axis is circulated in total by four wall surfaces with characteristic properties.
In Fig. 1 the handle 3 is shown with a view of the third wall surface 7. The third wall surface 7 is formed as a finger support surface and has for this purpose introduced Fingerauflagerillen 8 and between the Fingerauflagerillen 8 extending webs 9. The third wall surface 7 has further perpendicular to the longitudinal axis, which is defined by the pin 6, a substantially arcuate course with a vertex. This is evident from the drawn contour line 10. The Fingerauflagerillen 8 are each attached to the vertex, so that there is a wavy crest line at this point in the direction of the longitudinal axis. On both sides of the Fingerauflagerillen 8, the third wall surface 7 is formed substantially flat.

The base of the handle 3, an upper plateau surface 11 is formed, which has a circumferential overhang 12. By the overhang 12, the plateau surface 11 of the base of the handle 3 is over, creating a support surface is created for the hand enclosing the hand. As a result, the pressure necessary for the sharpening process can be easily generated in the direction of the pin 6 or in the direction of the longitudinal axis.

Fig. 2 shows the pen sharpener 1 from a different direction. Across from Fig. 1 the third wall surface 7 is turned away to the left. You can still see the Fingerauflagerillen 8 and the intermediate webs 9. One looks obliquely from below against the underside of the upper plateau surface 11. To avoid pressure points of the underside of the upper plateau surface 11 finger recesses 14 are formed.

From the in Fig. 2 the viewing direction shown can be seen the second wall surface 16 of the base of the handle 3. The second wall surface 16 is formed substantially saddle-shaped. One recognizes the convex curvature in the circumferential direction and the concave curvature in the direction of the longitudinal or pin axis. Since the third wall surface 7 or finger support surface is arranged to the left of the second wall surface 16 or the surface of the thumb ball, the illustrated pencil sharpener 1 is designed ergonomically for a left-hander.

At the end opposite the pin 6 or the tip insert 4, the handle 3 has a flat lower bearing surface 18.

In Fig. 3 the pencil sharpener 1 is again shown from a different angle. It can be seen now that the third wall surface 7 or finger support surface at the bottom of the handle 3. From this representation it is apparent that the lower support surface 18 consists of two mutually bevelled part levels. In Fig. 3 is the upwardly inclined tilted part plane 18 'can be seen.

One looks at the third wall surface 7 or finger support surface opposite first wall surface 20, in which a thumb rest 21 is formed. The thumb rest 21 is formed substantially flat in the circumferential direction. Overall, a saddle-shaped shape of the first wall surface 20 results.

Between the first wall surface 20 and the third wall surface 7, the fourth wall surface 23 can be seen. This has, as can be seen from the drawn contour line 24, a convex curvature in the circumferential direction and a concave curvature in the longitudinal direction. In other words, the fourth wall surface 23 is similar to the second wall surface 16, namely saddle-shaped configured. If a right-handed person grasps the illustrated pencil sharpener 1, the fourth wall surface 23 serves as a thumb-ball support surface. The second wall surface 16 is exposed in this case between the thumb and the remaining fingers and then acts as a peripheral end surface. The pencil sharpener 1 shown is thus ergonomically shaped both for a left-handed and for a right-handed person.

From the in Fig. 4 In particular, the first wall surface 20 with molded-on thumb resting groove 21 can be seen. The design of the lower support surface 18 with a tilted part plane 18 'is clearly visible.

In Fig. 5 is the schematic in the Fig. 1 to 4 shown pen tip 1 as it is encompassed by a human left hand 26. One recognizes those in the human hand-based base 31 of the handle 3. The contour of the base 31 is formed by the first, second, third and fourth wall surface 20, 16, 7 and 23 respectively. Here, the first wall surface 20 is the thumb 29, the second wall surface 16 of the thumb ball, the third wall surface 7 of the fingers (shown are index finger 27 and middle finger 28) on; the fourth wall surface 23 serves as a peripheral end surface. It is not enclosed by the hand 26.

Next you can see the base 31 of the handle 3 molded upper plateau surface 11, which rests on the human hand 26 on the surface formed by the thumb 29 and index finger 27. The outline of the plateau surface 11 is shown here by dashed lines.

The tip insert 4 is inserted into the pencil sharpener 1 centrally in the base 31 of the handle 3. The tip insert 4 has two pin guide channels 33 with different diameters. In each of the pin guide channels 33, which are formed tapered, a paring knife 34 is used in each case to the tips of a pin used.

Fig. 6 shows the pen sharpener 1 with ergonomically trained handle 3 in a longitudinal section. The tip insert 4 with pin guide channel 33 and paring knife 34 is inserted by means of a cover 35 in a bore 37. The bore 37 is centrally inserted in the base 3 of the pen point 1. The lid 35 is removable for emptying the bore 37 of spiked waste.

In a alternative shown in dashed lines, the bore 37, which receives the tip insert 4, extends to the lower support surface 18. Here, the bore 37 is closed by means of a removable cover 38. In the dashed variant, the tip insert 4 can be firmly mounted in the handle 3. The bore 37 is emptied of garbage by the lid 38 is opened.

LIST OF REFERENCE NUMBERS

1

pencil sharpener

3

handle

4

sharpener insert

6

pen

7

third wall surface

8th

Finger support grooves

9

Stege

10

contour line

11

upper plateau surface

12

overhang

14

finger grooves

16

second wall surface

18

lower support surface

18 '

tilted part plane

20

first wall surface

21

Thumb support groove

23

fourth wall surface

24

contour line

26

human hand

27

index finger

28

middle finger

29

thumb

31

Base

33

Pin guide channel

34

paring knife

35

cover

37

drilling

38

cover

Claims (20)

1. Pencil sharpener (1) comprising a handle (3) with a central longitudinal axis having a sharpener insert (4) inserted in the handle (3) along the longitudinal axis with a pencil guide channel (33) and a paring blade (34),
   characterized in that
   the handle (3) comprises a base (31) capable of being gripped by a human hand (26) with the thumb (29) and the index finger (27), the base being provided with a formed thumb support groove (21) running partially around the longitudinal axis and lying opposite it at least one finger support groove (8) running partially around the longitudinal axis.
2. Pencil sharpener (1) according to Claim 1,
   characterized in that
   a plurality of parallel-oriented finger support grooves (8) are formed opposite the thumb support groove (21), and in that the finger support grooves (8) are separated from one another by interjacent steps (9).
3. Pencil sharpener (1) according to Claim 1 or 2,
   characterized in that
   the base (31) is surrounded around its longitudinal axis essentially by a first (20), a second (16), a third (7) and a fourth wall surface (23), in that the wall surfaces (20, 16, 7, 23) are formed in such a way as to blend softly into one another in the peripheral direction, in that the first (20) and the third (7) and the second (16) and the fourth wall surface (23) lie opposite one another in each case, the thumb support groove (21) being formed in the first (20) wall surface, and the one or more finger support grooves (8) being formed in the third wall surface (7), and in that the second wall surface (16) is essentially in the form of a saddle for the purpose of supporting the ball of the thumb.
4. Pencil sharpener (1) according to Claim 3,
   characterized in that
   the first wall surface (20) is also of saddle-shaped execution.
5. Pencil sharpener (1) according to Claim 3 or 4,
   characterized in that
   the third wall surface (7) possesses an essentially arched cross section with a vertex running transversely to the longitudinal axis, in that the one or more finger support grooves (8) is/are formed in relation to the vertex, so that the vertex line running parallel to the longitudinal axis on the wall surface (7) possesses an undulating course, and in that the remaining surface area is essentially smooth.
6. Pencil sharpener (1) according to one of Claims 3 to 5,
   characterized in that
   the fourth wall surface (23) exhibits a form similar to that of the second wall surface (16).
7. Pencil sharpener (1) according to one of Claims 1 to 6,
   characterized in that
   a projecting upper flat surface (11) perpendicular to the longitudinal axis is formed on the base (31).
8. Pencil sharpener (1) according to Claim 7,
   characterized in that
   finger recesses (14) intended to support the thumb and the index finger are formed beneath the projecting part (12) of the upper flat surface (11).
9. Pencil sharpener (1) according to one of Claims 1 to 8,
   characterized in that
   a lower flat support surface (18) running perpendicular to the longitudinal axis is formed on the base (31).
10. Pencil sharpener (1) according to Claim 9,
    characterized in that
    the lower support surface (18) is executed as two flat surfaces (e.g. 18') that are inclined in relation to one another.
11. Pencil sharpener (1) according to one of Claims 1 to 10,
    characterized in that
    the sharpener insert (4) is inserted centrally into the base (31) more or less parallel to the longitudinal axis.
12. Pencil sharpener (1) according to one of the foregoing claims,
    characterized in that
    the sharpener insert (4) is inserted into a bore (37) intended to receive sharpening waste.
13. Pencil sharpener (1) according to Claim 12,
    characterized in that
    the sharpener insert (4) is inserted in a detachable manner to permit emptying of the bore (37).
14. Pencil sharpener (1) according to Claims 12 or 13,
    characterized in that
    the handle (3) on its under side exhibits a closable opening to permit emptying of the bore (37).
15. Pencil sharpener (1) according to one of the foregoing claims,
    characterized in that
    the handle (3) consists of materials possessing different elasticity.
16. Pencil sharpener (1) according to Claim 15,
    characterized in that
    the handle (3) consists of one material of higher elasticity and one material of lower elasticity.
17. Method for the manufacture of a pencil sharpener (1) according to one of Claims 1 to 16, involving the following steps:

    - an essentially cylindrical body having more or less the same dimensions as a human hand (26) made from a formable mass is provided with a place holder aligned along the cylindrical axis to create room for the sharpener insert (4),

    - the body is securely gripped manually, for which purpose at least a part of the internal contours of a human hand (26) are formed on the body,

    - the formed body is either inserted with the place holder removed, as appropriate, as a rough pattern, with the help of which the handle (3) is manufactured by means of a forming process technology, in particular a casting, pouring, injecting, turning, milling or laser machining technology,

    - or the formed body for the handle (3) is cured, in conjunction with which the place holder is removed before or after the curing, as appropriate,

    - a sharpener insert (4) is inserted into the opening created by the place holder.
18. Method according to Claim 17,
    characterized in that
    the formable mass consists of a kneaded mass made of a thermosetting plastic, and in that the formed body is cured to form the handle, for example by means of a thermal treatment.
19. Method according to Claims 17 or 18,
    characterized in that
    materials of different plasticity are used for the formable mass.
20. Method according to Claim 19,
    characterized in that
    a material of higher plasticity and a material of lower plasticity are used.

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