EP1072364B1 - Tool handle - Google Patents

Abstract

The handle extends along the longitudinal axis from an endface (1) facing the tool to a rounded end (2). Over a considerable part of its length, the handle has a cross section roughly in the shape of a pentagon. The alignment of the pentagon remains unaltered along the length of the handle. The cross section may pass into a circle in the region of the rounded end and/or the endface facing the tool.

Description

There are a variety of different handle shapes of screwdrivers or similar tools. The oldest screwdrivers have a circular cross-section and an approximately convex longitudinal section. In addition to the circular cross-section and cross-sections are known based on a Zweierteilung or a Dreierteilung. These include cross sections in the form of a flattened circle and triangular and hexagonal cross sections. The polygonal cross sections have been chosen to improve the transmission of torques.

There is already a booklet for hand tools known (DE 9202672), which has a pentagonal cross-section. The edges of the pentagonal cross-section are rounded, with the arc length of the rounded portion of the cross-section being substantially the same throughout.

It has also been proposed a screwdriver handle having a pentagonal cross section at one point (DE 30 04 957 A1).

The invention is based on the object, an ergonomically improved handle for a screwdriver or to create a similar tool with which also a torque is to be transmitted. Tools of this type are, for example, screw clamps, where for tightening a screw movement must be performed, also chisels, files, hacksaws or the like. In which, for example, a rotation must be prevented, which means that also a torque must be applied, namely to prevent rotation.

To solve this problem, the invention proposes a tool handle with the features of claim 1. Further developments of the invention are the subject matter of the dependent claims, the wording of which as well as the wording of the abstract is incorporated by reference into the content of the description.

By present over a substantial part of the length of the handle cross-sectional shape in the form of a preferably rounded pentagon, the shape of the handle is better adapted to the human hand. Only in the end areas, where a user attacks for support, the pentagonal shape does not exist.

For symmetry reasons, the invention prefers the cross section in the form of an approximate regular pentagon. If symmetry is not required, such as with a handle for a hacksaw, an irregular pentagon can also be used.

In a further development of the invention can be provided that the cross-sectional shape has rounded corner portions, which lie on a circular arc with a lying in the longitudinal axis of the handle center. The pentagons are therefore not completely formed, but their sides are connected by rounded sections.

For example, these sides of the approximated pentagon shape may be slightly curved, with a much larger radius than the rounded corner portions. In particular, however, the sides of the cross-sectional shape may be rectilinear.

The handle terminating end tip of the handle serves to allow the user to rest on the handle. Optionally, it can also be used to exert a certain feed movement on the handle or the workpiece, for example, when a screw is to be screwed into wood. Since it is not about the transmission of torque to the handle here at this point, according to the invention, the cross section of the handle in the region of the end tip go into a circle.

Something similar also applies to the opposite end face, which is assigned to the workpiece. In the area of this end face, the user normally attacks only with his thumb and forefinger, for example to control only the orientation of the handle. Again, it may be provided according to the invention that the cross section merges into a circular shape.

To further improve the adaptation of the handle to the human hand, the invention provides that the handle has two points of local maximum cross-section, from which the handle merges into the respective end regions, namely the end face associated with the workpiece and the end tip. At least between these two points of a larger cross section or diameter according to the invention, the pentagonal shape of the cross section should be present.

The shape of the tool handle can be represented by a rotationally symmetrical body with longitudinally extending flats.

In a further development of the invention it can be provided that a line connecting the transition between the circular arc-shaped corner sections and the approximately rectilinear sides of the cross-sectional shape does not follow the longitudinal contour of the handle.

This can also be expressed as the angle over which the circular arc portion of the corners extends is not equal at all points of the handle.

In a further development of the invention it is provided that the tool handle has a position of the first cross-sectional maximum, which has a distance of about 30% of the length of the handle from the tip end of the handle.

In a further development of the invention, the tool handle has a position of a second maximum cross-section, which has a distance of about 60% to 70% of the length of the handle from the tip end of the handle.

In this case, the length of the handle is to be understood as the length available to the user for engagement, that is, starting from the tip of the blade up to a point at which the user supports his thumb and possibly the index finger.
In a further development of the invention, it can be provided that the diameter of the tool handle at the location of the first cross-sectional maximum is about 15% to 18% greater than at the location of the second maximum.

In a further development of the invention it can be provided that the approximated pentagonal shape of the cross section of the tool handle ends at the location of the second cross-sectional maximum and there transitions into a circular cross-sectional shape. It turned out that at this point a circle form makes sense, since with the ends of the index finger and thumb a leadership of the tool to be performed.

In a further development of the invention it can be provided that the longitudinal profile of the tool handle is formed from the point of the second cross-sectional maximum to concave, preferably up to the end of the handle associated with the tool. In this area, the tool can either be twisted quickly or carried out a support of the fingers.

In a further development of the invention can be provided that the smallest diameter of the handle between the location of the second cross-sectional maximum and the end of the handle associated with the tool.

In particular, it can be provided that the maximum diameter of the handle is about 70% to 80% larger than the smallest diameter of the handle.

In a development of the invention, it can be provided that the surface is made softer over at least part of the length of the handle than in the region of the free end of the handle. There, the material of the handle itself is up to the surface available. The softer surface may be made, for example, by a coating or otherwise. The free end of the handle preferably forms a semicircular striking cap.

For example, the handle body consists essentially entirely of impact-resistant polypropylene, while the softer surface may have a Shore hardness of about 75 to 85. For example, it may be a polyolefin-based elastomer.

In particular, it can be provided that the softer area of the surface is between the two diameter maxima extends, or in other words in the region of the handle, where this has its pentagonal cross-section.

Fig. 1

eine perspektivische Ansicht eines Schraubendrehergriffs nach der Erfindung;

Fig. 2

eine Seitenansicht des Schraubendrehergriffs der Figur 1;

Fig. 3

eine Stirnansicht des Schraubendrehergriffs von unten in Figur 2;

Fig. 4

einen Schnitt längs Linie IV-IV in Figur 2;

Fig. 5

einen Schnitt durch die Stelle des Handgriffs, wo dieser ein Querschnittsmaximum aufweist;

Fig. 6

einen Schnitt längs Linie VI-VI in Figur 2;

Fig. 7

einen Schnitt längs Linie VII-VII in Figur 2;

Fig. 8

einen Querschnitt durch die Stelle kurz vor der dem Werkstück zugeordneten Stirnfläche, wo der Griff seinen kleinsten Durchmesser aufweist;

Fig. 9

eine der Figur 2 entsprechende Seitenansicht.

Fig. 10

eine perspektivische Ansicht eines Werkzeuggriffs nach der Erfindung;

Fig. 11

eine Seitenansicht des Werkzeuggriffs nach der Erfindung;

Fig. 12

einen Längsschnitt durch den Werkzeuggriff;

Fig. 13

bis Figur 18 Querschnitte durch den Werkzeuggriff in verschiedenen Ebenen, die in Figur 11 angedeutet sind.

Further features, details and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention and from the drawing. Hereby show:

Fig. 1

a perspective view of a screwdriver handle according to the invention;

Fig. 2

a side view of the screwdriver handle of Figure 1;

Fig. 3

an end view of the screwdriver handle from below in Figure 2;

Fig. 4

a section along line IV-IV in Figure 2;

Fig. 5

a section through the location of the handle, where this has a cross-sectional maximum;

Fig. 6

a section along line VI-VI in Figure 2;

Fig. 7

a section along line VII-VII in Figure 2;

Fig. 8

a cross section through the point just before the end face associated with the workpiece, where the handle has its smallest diameter;

Fig. 9

one of Figure 2 corresponding side view.

Fig. 10

a perspective view of a tool handle according to the invention;

Fig. 11

a side view of the tool handle according to the invention;

Fig. 12

a longitudinal section through the tool handle;

Fig. 13

to Figure 18 are cross-sections through the tool handle in different planes, which are indicated in Figure 11.

Figure 1 shows a perspective view of a screwdriver handle without the blade associated with a screwdriver. The handle extends from a left front view facing end face 1, from which normally protrudes the blade with the tool, along a longitudinal axis to an end cap 2. The end cap 2 has a convexly curved shape. The length of the handle is about the width of a human hand. Depending on the size of the blade, which is approximately adapted to the size of the screw to be operated, the size of the handle may vary slightly.

FIG. 2 now shows a side view of the handle. At first glance, the handle seems to be asymmetrical. This follows from the cross-sectional shape of the pentagon, since the side view, for example, left shows a contour that follows the corners of the pentagons, while the flat side of the pentagons comes to rest on the right. The handle begins in Figure 2 at the rear end in a circular cross-section, see the section of Figure 4. From there, the cross-sectional shape is progressively pentagonal, proceeding to the plane 5, wherein the plane perpendicular to the longitudinal axis VV shows the point at which Handle has its largest cross section. This section is shown in FIG. It can also be seen from FIG. 5 that the outer sides of the cross section are formed by straight lines 3, while the corners 4 of the pentagon and the edges of the handle are rounded at 4. The pentagon is shown in dashed lines Circle 6 inscribed. It is a regular pentagon.

From the cross-sectional plane V on the diameter or the size of the cross-section decreases again to the transverse plane VI, where the size of the cross-section reaches a local minimum. This cross section is shown in FIG. Again, it can be seen that the side surfaces of the handle are formed in cross section by straight lines 3, while the edges 4 are more or less rounded.

From the level VI of the locally smallest cross section, the cross section or diameter expands again until the level VII is reached, where again a local maximum of the cross section is reached. This cross section is shown in FIG.

Now, the size of the cross section decreases again to a cross-sectional minimum in the plane VIII. As can be seen from FIG. 8, a circular cross-section is again present at this point, which then also remains up to the end face 1.

From a comparison of Figures 4 to 8 can be seen, as well as from Figure 3, that the orientation of the pentagons, which are formed by the cross sections, is maintained over the length of the handle.

Due to the pentagonal cross-sectional shape in the part of the handle in which the user engages with the closed hand to transmit torque, the handle is better adapted to the anatomical structure of a human hand, so that less fatigue even with prolonged use of a screwdriver.

The handle is designed substantially as a one-piece body, preferably made of impact-resistant polypropylene.

In a region which extends at least from the plane V to VII, the surface of the handle is made softer, for example by an encapsulation with an elastomer of Shore hardness of 75 to 85.

It is particularly favorable if this area with the softer surface is still somewhat longer, for example from level IV to level VIII.

The softer surface improves handling of the handle. In the area of the end 2, however, the hard base remains on the surface, so that this end can serve as a beating end. The same applies to the area between the plane VIII and the front end 1. This area serves to support the fingers, but not to transmit a torque.

Figure 10 shows in perspective a tool handle according to the invention, as it can be used for example for a screwdriver. The shaft of the screwdriver is not shown. However, the handle can also be used for clamping screw clamps, as a handle for hacksaws, as a handle for chisels or files. These tools are either to perform a rotating or screwing movement, or to secure a tool against rotation, which must also be achieved by applying a torque.

The tool handle extends from an end face 1, from which the shaft of a screwdriver would emerge, along a longitudinal axis to an opposite free end 2. In the region of the free end 2, the handle is rounded and thereby forms a dome. This crest lies in the use of the Tool on the palm or on the bale. Between these two ends, the tool handle has a position of a cross-sectional maximum, which is shown in Figure 11 by the plane VI-VI. The distance of this plane from the tip end 2 of the tool handle is about 30% of the length of the handle. The length of the handle is the distance between the free end and the front end face 1 to understand. In the area of this end face 1, the handle has a diameter broadening, at which a user can support his index finger or thumb. It would be conceivable to extend the handle from this end face 1, without this having any influence on the use of the handle when turning or screwing. Such an extension should not be included in the calculation of the length of the handle.

The handle has a second point with a cross-sectional maximum at a distance from the point of the largest diameter, in Figure 11, the level IV-IV. Between these two levels is a place, in Figure 11, the level V-V present at which a local cross-sectional minimum is present.

Starting from the free end of the blade 2 of the handle, this initially has a circular cross-section. At this point, no torque needs to be transmitted, so that the cross-section for reasons of symmetry is circular.

Starting from the plane VIII, the cross-section of the handle is gradually approached to a pentagon. The "corners" of the pentagon still remain rounded, with a radius of curvature centered in the longitudinal axis of the handle. The sides of the pentagons lie on straight lines. These straight sides of the pentagonal cross-section, viewed along the length of the handle, form flats 3, which can be seen in FIG. The places where the flat sides of the pentagons merge into the remaining curvature of the outer shape of the handle form lines 4. These lines 4 are not parallel to the indicated center 5 of the edges. So you do not follow the longitudinal contour of the handle.

The flats 3 terminate in the region of the point of the second cross-sectional maximum. At this point, the cross section of the handle becomes circular again. Subsequently, the value of the diameter gradually decreases to the level C, where the diameter has a minimum. Subsequently, the diameter increases again. As a result, the longitudinal profile between the plane IV-IV and the front end 1 is concave.

The longitudinal section of FIG. 12 is laid through a plane containing the longitudinal axis of the handle. From the comparison of the two outer contours one can see the asymmetry of the right to the left outer contour.

Figures 13 to 18 show cross sections through the shape of the handle. FIG. 13 corresponds to the plane IV-IV in FIG. 11. At this point, in the direction of the tool end of the handle, the zone with the concave outer contour begins in a longitudinal section. In the opposite direction begins here the portion of the handle in which the flats 3 are present. This is apparent from Figure 14, which represents a section through the position of the cross-sectional maximum corresponding to level V-V. Here it can be seen that the flats 3 form the side of a regular pentagon. These rectilinear sides of the pentagon are interconnected by curved corner portions 6, in which the cross-sectional contour lie on a circle whose center lies in the longitudinal axis 7 of the tool handle.

This shape of a pentagon rounded in the corner area continues to the plane VI-VI, see FIG. 15. Here, the location of the largest cross-sectional maximum is present. Subsequently, the cross-section, while retaining the pentagonal shape, decreases again in the direction of the plane VI-VII, shown in FIG. 16. pentagonal shape again in the direction of the plane VII-VII, shown in Figure 16.

In the subsequent level VIII-VIII, see Figure 17, the end of the flats 13 is reached, so that now again a circular cross section is present. This remains until the free end.

Example:

In one embodiment, the total length of the handle, starting from the frontal plane 1, 105 mm. This is a common size with screwdrivers.

The level VIII has, starting from the frontal plane 1, a distance of 17 mm, the level VII a distance of 38 mm, the level VI a distance 52 mm, the plane V a distance of 72 mm and the plane IV a distance of 95 mm.

The radius of curvature of the outer contour in the side view is between about 17 mm and about 25 mm.

The diameter of the handle in the embodiment just mentioned lies in the plane IV at about 26 mm when taking as a diameter the diameter of the circle in which the pentagon is inscribed.

In the plane V the diameter is about 36 mm, in the plane VI about 30 mm, in the plane VII at about 31 mm and in the plane VIII at about 20 mm.

Figure 2 shows a side view of the screwdriver handle from a direction parallel to a side of the pentagon forming the cross-sectional shape of the handle. It also follows that in Figure 2 to seeing left side edge is not symmetrical to the right side edge.

FIG. 9 now shows the handle from another direction, namely from a direction which extends radially and is arranged such that a rounded side edge 4 is arranged in the middle. This results in a symmetrical shape of the screwdriver handle.

The lines 3 forming the sides of the pentagon in the various sections of FIGS. 5 to 7 are, in the side view of FIG. 9, parts of surfaces 7 which appear as flats in the outer shape of the handle. These surfaces 7 are thus formed so that they are rectilinear in cross section through the handle.

Since the handle in the region of its axial ends has a circular cross-section, which then gradually merges into the pentagonal cross section, the surfaces 7 over the length of the handle have different widths, which is reinforced by the rounded edges of the edges 4 of the handle. This results in the shape of the handle to be seen in FIG.

Approximately in the area in which the surfaces 7 extend, the slightly softer surface texture of the handle is also present. The parts in which the surface is softer may also have a different color.

The example given in the description is only an example to give examples of the other dimensions by means of a screwdriver handle customary in its length dimension of 105 mm. With correspondingly smaller handles, the other dimensions change accordingly.

Claims (16)

1. Tool handle, especially for screw drivers, which

   1.1 extends along a longitudinal axis from a face surface (1) on the tool up to a rounded crest (2) and

   1.2 exhibits a cross-section approximately in the shape of a pentagon along a significant part of its length, whereby

   1.3 the orientation of the pentagonal shape does not change over the length of the handle,

   1.4 with two positions (V, VII) exhibiting a maximum cross-section, from which the handle blends into the respective end sections, whereby the pentagonal shape is at least embodied between these two positions (V, VII), and

   1.5 with a position (VI) of a local cross-section minimum between both the positions (V, VII) that exhibit maximum cross-section,
   characterized in that

   1.6 the position (V) of the first maximum cross-section from the crest end (2) of the handle exhibits a distance of about 30 % of the entire length of the handle and

   1.7 the position (VII) of the second maximum cross-section from the crest end (2) of the handle exhibits a distance of about 60 % up to 70 % of the length of the handle.
2. Handle according to Claim 1, in which the cross-section of the handle in the section of the end crest (2) and/or in the section of the face surface (1) relating to the work piece blends into a circle.
3. Handle according to Claim 1 or 2, with a position of minimum cross-section between the face surface (1) relating to the work piece and the adjoining maximum cross-section (VII), whereby the minimum cross-section exhibits the cross-sectional shape of a circle.
4. Tool handle according to one of the previous Claims, in which the cross-sectional shape exhibits rounded corner sections which lie on a circular curve with a middle point that lies in the longitudinal axis of the handle.
5. Tool handle according to Claim 4, in which the curve-shaped corner sections of the cross-sectional shape are connected by sides being between straight and convex in form.
6. Tool handle according to one of the previous Claims, in which the cross-section in the rest part of the length of the handle is concentric.
7. Tool handle according to one of the previous Claims, in which the shape is formed through a rotationally symmetrical body with flattenings (3) extending in longitudinal direction.
8. Tool handle according to one of the previous Claims, in which a line (4) connecting the transition between the curve-shaped corner sections and the particularly straight-running sides of the cross-sectional shape does not follow the longitudinal contour of the handle.
9. Tool handle according to one of the previous Claims, in which the diameter of the handle at the position (V) of the first maximum cross-section is about 15 % to 18 % larger than at the position (VII) of the second maximum cross-section.
10. Tool handle according to one of the previous Claims, in which the somewhat pentagonal cross-sectional shape ends at position (VII) of the second maximum cross-section.
11. Tool handle according to one of the previous Claims, in which the longitudinal profile from position (VII) of the second maximum cross-section on is formed concave, preferentially up to the end (1) of the handle relating to the tool.
12. Tool handle according to one of the previous Claims, in which the smallest diameter of the handle lies between position (VII) of the second maximum cross-section and the end (1) of the handle relating to the tool.
13. Tool handle according to one of the previous Claims, in which the maximum diameter of the handle is about 70 % to 80 % larger than the smallest diameter.
14. Handle according to one of the previous Claims, in which the surface at least along a part of the axial length of the handle is softer than in the end section (2) of the handle.
15. Handle according to Claim 14, in which the softer surface is intended to lie in the area between both outer cross-section maxima (V, VII).
16. Handle according to Claim 14 or 15, in which the softer surface is intended to lie in the section of the handle, where the latter exhibits its pentagonal cross-section.

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