EP1827766A1

EP1827766A1 - Handle

Info

Publication number: EP1827766A1
Application number: EP05824451A
Authority: EP
Inventors: Martin Holland-Letz
Original assignee: Felo Werkzeugfabrik Holland Letz GmbH
Current assignee: Felo Werkzeugfabrik Holland Letz GmbH
Priority date: 2004-12-23
Filing date: 2005-12-23
Publication date: 2007-09-05
Anticipated expiration: 2025-12-23
Also published as: US20070256276A1; EP1827766B1; ATE432796T1; US7877843B2; DE502005007435D1; DE102005037504B3; WO2006069759A1; ES2327143T3

Abstract

The present invention relates to a handle, in particular for use in a screwdriver. Such handle comprises an outer region having a first stiffness and an inner region comprising a second stiffness. According to the invention the second stiffness is smaller than the first stiffness. The inner region might be built with chambers and ribs wherein the chambers might be hollow or filled with a soft material, e.g. a gel or a soft porous or non-porous plastic material.

Description

HANDLE

The invention relates to a handle for

a screwdriver,

a screw clamp or

another device with which a force exerted on the lateral surface of the handle by the user torque to an arranged in the handle output member, such as a functional part or a blade of a screwdriver is transferable.

Furthermore, the invention relates to a method for producing such a handle.

STATE OF THE ART

A first further development of a handle for a screwdriver made of hard plastic to improve the feel has been proposed in US-PS 28 71 899. Accordingly, a prefabricated handle shell made of soft plastic is mounted on a handle core. Grip core and gripping jacket are positively connected to one another via profiles in order to transmit a torque in the circumferential direction. The use of soft plastic improves the grip of the handle. In a practical trial of the known handle, however, has shown that the soft grip coat lifts under heavy loads from the hard grip core and can form wrinkles. This "walking" called lifting the handle shell of the handle core leads in particular in case of continuous use of the known handle to a Painful blistering in the area of the user's palm and excessive stress on the hand bones causing inflammation.

To avoid the aforementioned disadvantages, it has been proposed in the following to join the grip core of a screwdriver cohesively with the grip shell, wherein the soft plastic

this form only distributed in the circumferential direction portions of the grip shell or

Surrounded in the circumferential direction closed the handle core

can, cf. in particular DE 92 02 550 W ₁ DE 43 04 965 A1, DE 295 15 833 W ₁ DE 195 39 200 A1, DE 295 17 276 U 1, DE 299 00 746 UI ₁ DE 299 04 082 W. Handles of this type are today mainly made of plastic by injection molding. For tools of higher quality as a good ergonomic design and feel of the handles are sought. In such handles made of two plastic components, the tool is anchored in a handle core made of hard plastic, and this handle core is encapsulated with a handle shell made of soft plastic, cf. For example, EP 0 627 974 B1. The handle shell made of soft plastic has a certain elasticity and gives a more pleasant gripping feeling than a handle, which is made only of hard plastic. The soft plastic also has u. U. a higher coefficient of friction than hard plastic. Therefore, with such a "2-component handle" higher torques can be transmitted as with a handle of the same size made of hard plastic. This is important for handles for screwdrivers, screw clamps, etc.

Further handles for deviating technology fields are known from DE 299 04 043 U1, DE 197 32 421 C2 and DE 101 13 368 A1.

OBJECT OF THE INVENTION

The invention is based on the object, taking into account the manufacturing possibilities and the mechanical properties of a handle for a screwdriver, a screw or other device with which a force exerted on the outer surface of the handle by the user torque to an arranged in the handle output member is transferable, and to propose a method of making the same, the Ergonomics and feel of the handle and / or the adjustment options of the handle to the respective hand of a user are improved, and thereby a good force and moment transfer from the hand of a user to the handle and on this example. On an output element such as a functional part or a Blade of a screwdriver is possible.

SOLUTION

The object underlying the invention is achieved by a handle according to the features of claim 1. Further embodiments of the handle for a screwdriver emerge according to the features of the dependent claims 2 to 32. Another solution of the invention underlying object is given by a A method according to the features of claim 33. Further embodiments of the method according to the invention emerge from the dependent patent claims 34 to 38.

DESCRIPTION OF THE INVENTION

In the following, the invention for use of the handle for a screwdriver will be explained for simplicity. The embodiments are analog transferable to the use of the handle for a screw clamp or other device with which a force exerted on the outer surface of the handle by the user torque to a arranged in the handle output member is transferable.

The invention is based on the finding that in the case of a design of a handle in accordance with the prior art mentioned at the outset, a conflict of objectives is to be solved:

On the one hand, the adaptability of the grip to the hand of a user and to hands of different sizes and thus an enlargement of the contact surface between the hand and the grip is increased when the stiffness of the grip jacket forming material is reduced.

- On the other hand, a possible stiff or hard material of the grip is desired for a transmission of high torques on the handle and / or for a stable even in hard applications lateral surface. This conflict of objectives is taken into account according to the prior art by a stiffness optimization depending on the individual case or by portions of the handle shell with high rigidity, which serve primarily a transmission of torque, and portions of the handle shell with low rigidity, which should improve the feel of the handle. In 2-component handles, as are known for example from DE 35 25 163, a compliance is not given in the area of the entire grip, because the hard grip core forms part of the grip surface and only other portions of the handle surface are coated with soft plastic. Furthermore, it has been shown that the handle sheath made of soft plastic in known handles usually only with a relatively small wall thickness, for example between 1, 5 and 3 mm, is formed and therefore not or only limited yielding. Finally, it has been shown that a design of the lateral surface of the handle with the soft plastic makes the lateral surface susceptible to damage.

According to the present invention, it is proposed that the handle has an outer region which has a closed lateral surface and interacts with the user's hand. The outer region is formed with an elastic material having a first rigidity. For example, the outer region can be an integral grip shell or a grip shell having a surface with different partial regions, for example a partial region made of a hard plastic and other partial regions made of a soft plastic. The different partial regions can be arranged alternately in the longitudinal direction and / or in the circumferential direction.

Furthermore, an inner region is provided according to the invention, the

a single, in a cross section in the circumferential direction circumferential chamber or

several evenly distributed in the circumferential direction chambers

having. These chambers are referred to in the claim using "at least one chamber", whereby either a single existing circumferentially rotating chamber, all chambers in several evenly distributed in the circumferential direction chambers or a part of several evenly distributed in the circumferential direction Chambers can be meant. The second rigidity of the at least one chamber is less than the aforementioned first stiffness.

A dimensioning of the outer region, for example, the extent in the longitudinal direction of the handle and / or in the radial direction, the inner region, the chambers and the number and arrangement and the choice of the first and second stiffness is such that upon application of the handle with usual Surface pressures of the outer region is deformable and with this deformation, a deformation of the chambers can be brought about. Accordingly, the inner region does not support the outer region as rigidly as possible and thus limits possible deformations of the outer region, but rather represents a radially yielding support. On the other hand, the user's hand acts on the outer region with a comparatively high first rigidity, resulting in a good Transmission of torque is possible. While the prior art follows the prejudice that the stiffness must increase radially inward in a handle, so the invention treads for the first time the way that - at least in partial peripheral areas - the stiffness can decrease radially inward.

By the embodiment according to the invention can be exploited that a higher specific normal force can be exerted by the user's fingers as by the palm. As a result, the outer area in the area of the fingers is more pronounced than in the area of the palm, which can increase the contact surface for the fingers and in the area of the fingers a greater force can be introduced into the handle. Due to the different yielding, seen in cross-section, the handle bulged more to the palm, which may correspond to the shape of a natural hand cavity. Overall, a much larger contact surface between the palm and the lateral surface of the handle can be formed according to the invention than in a handle according to the prior art.

The documents DE 101 13 368 A1 and DE 197 32 421 C2 disclose handles for a hammer. The user accelerates over the handle via a return movement of the hammer to an impact velocity, which defines the impulse during the hammer blow. To dampen the shock in an impact of the hammer head on the object to be hammered, the cited documents propose to provide an air pocket or a passage in the direction of impact, ie on the top and bottom of the handle, in Area of which can collide with the shock, the top and bottom of the handle, so that the impact is transmitted to the user with the interposition of suspension and / or damping. Notwithstanding this, according to the invention, a handle insert for a screwdriver, which is not about the attenuation of a possible shock, but rather on the one hand to a u. U. stiff transmission of torque in the circumferential direction and on the other hand the best possible adaptation of the handle to the user's hand. For this purpose, the internal chambers are evenly distributed over the circumference of the handle or extend completely in the circumferential direction.

Alternatively or cumulatively, the arrangement of the stiffer area in the area of the lateral surface-in contrast to 2-component handles in which the lateral surface is formed with the more flexible material-can lead to a hard outer surface that is resistant even in harsh operating conditions.

According to a further embodiment of the invention, a dimensioning and selection of the stiffnesses takes place such that the rigidity of the handle in the radial direction is smaller than the rigidity of the handle in the circumferential direction. This means that when a force is exerted in the circumferential direction, the deformation caused is smaller than the deformation which is caused with a corresponding radial loading of the handle with a deformation of the at least one chamber. The deformation in the circumferential direction is in particular smaller by at least a factor of 2, 5, 10 or 30 than the corresponding deformation in the radial direction.

According to one embodiment of the invention, the chambers are formed as hollow chambers. Thus, the second stiffness in the region of the hollow chambers is zero. This means that the outer regions radially outwardly of the hollow chambers form cantilevered areas, which can be made yielding depending on the selected radial wall thickness even with relatively high first stiffness under an evasive movement in the hollow chambers.

On the other hand, in the chambers may be arranged any material with the second stiffness, for example, be injected a soft plastic or a liquid, a powder or a gel, these materials fill the chambers in whole or in part. During a deformation of the outer region, the volume of the chambers may each remain constant by deforming portions of the outer region associated with the chamber radially inwardly, whereby in this area the chambers are reduced, while another portions of the same chambers can expand radially and accordingly the associated outer region is deformed radially outward. It is also possible that a plurality of chambers are connected to each other, so that u. One chamber reduces its volume due to deformation while another chamber increases its volume. As a transfer means of the aforementioned volume changes, for example, a gel can be used, which is displaced in one chamber or a portion of the chamber in another portion of the same chamber or another chamber on which or a less strong pressure of the user's hand acts. In this way, an adaptation to the user's hand not only by a deformation radially inwardly, but simultaneously by a deformation of other portions of the handle radially outwards.

The chambers may be oriented arbitrarily, for example with a longitudinal axis, which is oriented at a projection in a longitudinal plane of the handle obliquely to the longitudinal axis of the handle or transversely thereto. Also, the chambers may be "spirally" wound around the longitudinal axis of the handle. According to a particular proposal of the invention, the portions extend approximately in the longitudinal direction of the handle. About such chambers can be specifically acted on the stiffness behavior in the region of a peripheral segment of the handle. The casting cores for forming the chambers can be removed in a simple manner in the longitudinal direction in a production of the handle by means of an injection molding process. It is also possible that several chambers are arranged lying one behind the other in the longitudinal direction. This may, for example, be the case when the outer region consists of a one-piece gripping jacket, which is made in the manner of a sleeve by itself and is pushed onto the handle core.

According to a further embodiment of the handle according to the invention, the chambers are formed in the radial direction with a curvature. By a curvature of the outer contour of the chambers, the wall thickness of the outer area can be specified in this area, so that the wall thickness can be specified constructively according to the requirements, wherein in areas of reduced wall thickness, a particularly elastic behavior of the outer area can be brought about , In the same way, the Forming the wall thickness and influencing the elasticity can be achieved by the curvature of the outer contour of the chambers in the longitudinal direction does not follow the outer contour of the handle. On the other hand, it is possible that due to the curvature lying inside of the chambers areas with large radial extent are present in which, for example, a good connection of a functional part of a screwdriver can be made to the handle.

In the event that approximately a constant wall thickness of the outer region in the region of the chambers is desired, the curvature should be approximately matched to the curvature of the outer contour of the handle.

According to a further embodiment, the chambers may have a substantially constant over the longitudinal axis cross-section, which, for example, for a production of at least portions of the handle in an injection molding process, the hollow chambers can be molded with casting cores constant cross-section, whereby a removal of the casting core is simplified.

On the other hand, the chambers can also have a variable cross-section over the longitudinal axis, whereby the possibilities of influencing the rigidity and the variability can be increased over the longitudinal axis.

The chambers can be subsequently introduced, for example by means of holes or milling, in the inner region. In the event that at least the inner region of the handle is produced in an injection molding process, it is u. U. advantageous if the chambers are produced by casting cores during the injection molding process. In the event that the cores can not be removed directly on a straight or curved path from the inner region due to a curvature of the chambers and / or as a result of variable cross-sections, the elasticity of the inner region and / or the cores can advantageously be utilized, so that during removal of the casting cores deformations of the inner region and / or the casting cores occur.

If the handle is formed with a handle core and a grip jacket, then the inner region can optionally be formed in the grip core and / or in the grip shell. According to a particular embodiment of the handle, however, the inner region is in a radial transitional formed area between a handle core and a handle shell. In this case, the chambers, for example, in half, bounded by the handle core and the handle shell. This means that the chambers do not have to be introduced into the interior of the handle core and grip, but rather be formed by recesses or grooves of the handle core and / or the grip, recesses of handle core and grip coat can merge into each other. Such recesses or grooves can be produced, for example, by suitable design of a mold during injection molding of the handle core and / or the grip jacket or by subsequent introduction into the grip core and grip shell.

For a further inventive handle multiple chambers are separated by webs. About these webs, their material properties, profile and / or extent in the circumferential direction and radial direction can be done further influencing the feel and stiffness of the handle. On the other hand, via the webs, a connection of the outer region with lying within the inner region of the central areas of the handle, so that the design of the webs specifically affects the transmission of torque from the outer region to the central region, for example to a functional part of a screwdriver can be.

The webs may be oriented approximately radially in a cross section through the handle, with the result that the webs are acted upon by the pressing of the user's hand on the handle in the radial direction, ie in the longitudinal direction of the webs in the aforementioned cross section, while the transmission of torque applied to the webs with a shear stress in the circumferential direction or a bending moment about an axis parallel to the longitudinal axis of the handle.

Alternatively, the invention makes it possible that the webs in the cross section of the handle are inclined relative to a radial orientation at an inclination angle α. By choosing the angle of inclination α, the haptic properties and the stiffness can be further influenced by predetermining the stress of the webs with a normal force in the radial direction, with a bending moment and the mentioned shear stress in the use of the handle. According to a further proposal of the invention webs of different inclination angle α are present. If, for example, an angle of inclination α turns out to be advantageous for a transmission of torque in one direction, webs with the same amount of the angle of inclination, but of a different sign, can be provided so that an advantageous transmission of the torque in the opposite direction can also take place.

The chambers are preferably introduced via one side of the handle in the handle core and / or handle shell such that after the introduction of the chambers have these openings. These openings can be closed according to a proposal of the invention by means of a frontal cap, esp. At the rear end, which in this case thus closing and possibly sealing the chambers, but can also be multifunctional by the cap, the end of the Outside surface of the handle forms.

Furthermore, the invention proposes that the cap has at least one, the openings occlusive, rigid or elastic closure element. This may be a closure element for only one chamber or a single closure element for a plurality of openings of the chambers. For example, the closure element is designed as a ring. Such a ring or a closure element may be provided in addition to the closure of the openings with a color coding in the event that handles of different types are present.

According to a further embodiment of the handle, the cap is rotatable, which has advantages when applied to the cap normal forces in the direction of the longitudinal axis of the handle, for example, a screwdriver while the torque applied off the cap on the handle or a functional part of a screwdriver becomes.

The cap can be connected via a positive connection with the handle core and / or handle shell, for example via a latching connection, a locking connection, a thread o. Ä. Also possible is a frictional connection of the cap.

According to a further embodiment of the invention, the cap is connected via a cohesive solid connection. In this case, the cap can also be molded directly onto the further elements of the handle, in particular the grip core and / or grip shell. In a selection of the material for the outer region, it has proven to be advantageous to use a soft plastic having a hardness of 30 or 40 to 105 Shore A, for example, 30 or 50 to 85 Shore A, in particular 55 to 83 Shore A.

For a further embodiment of the invention, the chambers are bounded in the circumferential direction with webs and radially outwardly of the handle shell. Here, the grip casing may be formed with the end faces of the webs and with transition areas extending between these end faces. The transition areas can be "strip-shaped" and supported on the end faces of the webs. Are the webs sufficiently rigid, they can even stiff transmit torque. In addition, the transition areas are based on these rigid webs, so that forces applied in the transition regions are also transmitted to the webs, resulting in a good transmission of the torque at u. U. simultaneous yielding design can be given in the radial direction.

Extended possibilities for shaping the stiffness arise when materials with different stiffnesses are used for the webs, a material arranged in the chambers and the grip jacket. Here, the webs may be made of the same material as the handle core, for example, in one operation for an injection molding process, or other material.

For a further inventive handle an approximately central region of the lateral surface of the handle is formed in the circumferential direction alternately with the end faces of the webs and the transition regions. The approximately central region thus has the advantages explained above. In the approximately central area can thus be a particularly good

Transmission of torques with at the same time good adaptation to a hand of a

User done. For example, the central region also has the area of the handle with the largest outer diameter of the lateral surface. This central area is preceded by a front (and / or rear) area in the direction of the longitudinal axis of the handle (downstream). In the front (and / or rear) area extend the

Transition areas over the entire circumference of the lateral surface of the handle. As a result, a durable, continuous front (and / or rear) area can be provided, wherein u. U. a lower radial elasticity in this area can be accepted, since a lower radial adaptability to the user's hand is sufficient, for example, because here the diameter of the handle is already reduced in size, or only edge areas of the hand rest, which do not have to transmit large forces.

For a production of a handle, the invention proposes that first a handle core is produced, for example in an injection molding process. A grip core may have a recess lying inside for a replaceable functional part or be sprayed directly onto a functional part. Subsequently or in a parallel production step, casting cores are aligned in the direction of a longitudinal axis, in particular the longitudinal direction of the handle core, and distributed in the circumferential direction about the longitudinal axis. The casting cores are, u. U. together with the handle core, placed in a mold in which the cores (and u. U. The handle core) are coated with a handle shell in an injection molding process. In a subsequent method step, the casting cores are removed by movement in the direction of an end face, esp. The rear end face of the handle shell after curing of the grip. As a result, chambers are released, which have an opening in the region of the front side. Subsequently, the aforementioned openings or the chambers are at least partially closed.

According to a first embodiment of the method, a cap is used to close the openings, and thus the chambers. Further possibilities for influencing the stiffness arise for at least partial filling of the chambers with a material having the second rigidity.

Handle core and handle shell with the chambers can be made separately and connected together after curing. Alternatively, the grip coat can be connected to the grip core at the same time as an encapsulation of the casting cores.

Use can be a core slider to which the cores are attached as a "core finger" with orientation of the cores in the direction of the longitudinal axis and with a radial distance to the handle core. In this case, the casting cores can be moved with the core slider in a first step above the handle core. In a second method step, the grip shell is sprayed onto the handle core, wherein the chambers are molded. After the handle shell has hardened, the grip cores can be removed from the grip shell via the movement of the core slider. According to a development of this method, the cap has a closure element, wherein the closure element is inserted into a mold together with the grip core and the grip shell after removal of the casting cores. In this form, the cap is injected in an injection molding process, for example. In a third process step, wherein the injected material can press the closure member for closing the openings against the handle core and the handle shell and the material during the injection molding simultaneously cohesively with the handle core and / or the handle shell and the closure element connects.

Advantageous developments of the invention will become apparent from the dependent patent claims and the entire description. Further features are the drawings - in particular the illustrated geometries and the relative dimensions of several components to each other and their relative arrangement and operative connection - refer. The combination of features of different embodiments of the invention or features of different claims other than the selected back relationships is also possible and is hereby stimulated. This also applies to those features which are shown in separate drawing figures or are mentioned in their description. These features can also be combined with features of different claims.

BRIEF DESCRIPTION OF THE FIGURES

In the following, the invention will be further explained and described with reference to preferred embodiments of handles according to the invention shown in the figures.

Fig. 1 shows a handle for a screwdriver in a longitudinal section.

FIG. 2 shows a cross section M-II through the handle according to FIG. 1.

Fig. 3 shows a further embodiment of a handle for a screwdriver in a longitudinal section.

Fig. 4 shows a further inventive embodiment of a handle in one

Cross-section. Fig. 5 shows a further embodiment of a handle according to the invention with disassembled cap in a rear view.

Fig. 6 shows a further embodiment of a handle according to the invention in one

Cross-section.

Fig. 7 shows a further embodiment of a handle according to the invention in one

Longitudinal cut.

Fig. 8 shows a further embodiment of a handle according to the invention in one

Longitudinal cut.

9 shows a further embodiment according to the invention of a handle in a longitudinal section.

Fig. 10 shows a further embodiment of a handle according to the invention in one

Longitudinal cut.

FIG. 11 shows the configuration of the handle according to FIG. 10 in a cross section XI-XI.

Fig. 12 shows the configuration of the handle according to FIGS. 10 and 11 in a longitudinal section.

DESCRIPTION OF THE FIGURES

Fig. 1 shows an example of a handle 10 for a screwdriver 11, wherein the handle according to the invention can be used in conjunction with any tool.

The screwdriver 11 has a fixed or interchangeable inserted in the handle 10 functional part 12, for example, has a functional tip, not shown for an interaction with a screw or a suitable receptacle for a screwdriver use. The handle 10 has a handle core 13, the radially inner lying the functional part 12 while allowing a transmission of torque and normal forces in the direction of a longitudinal axis 14-14 receives. For example, the grip core 13 on the side facing away from the functional tip of the functional part 12 side of a paragraph 15 has a cylindrical outer surface 16, to which an end-side extension 17 connects. In the area of the lateral surface 16, a grip jacket 18, which is formed with a soft plastic, is sprayed onto it in an injection molding process. The outer surface of the grip shell 18 and a free outer surface of the handle core 13 form a continuous lateral surface 19, the outer contour 44 is adjusted in terms of ergonomics for a hand average size.

As can also be seen from FIG. 2, the handle 10 has six chambers 20 distributed in the circumferential direction about the longitudinal axis 14 and oriented in the direction of the longitudinal axis 14. The chambers

20 start from one of the functional tip facing away from end face 21 of the grip 18, have a circular ring segment-shaped cross section and are separated in the circumferential direction in each case by webs 22 from each other, wherein the webs of FIG. 2 may be tapered radially outward or have any cross-sectional profiles. Instead of the illustrated six chambers 20, any number of chambers 20 may be provided.

Radially outwardly from the chambers 20, the handle shell 18 forms an outer region 23, while an inner region 24 is formed with the webs 22 and the chambers 20. Radially inside of the inner region 24 of the handle core 13 is arranged with arranged in this functional part 12. According to FIG. 2, the connection between the grip core 13 and the grip jacket 18 can be reinforced in that the grip core 13 has ribs 25 which are received in corresponding radial, groove-shaped recesses 32 of the grip jacket 13. In principle, a connection between the handle core 13 and the grip jacket 18 can be made in a positive, frictional or cohesive manner, for example by means of an injection molding of the grip jacket 18 on the grip core 13.

The projection 17 is approximately cylindrically formed with a circumferential groove 27. A cap 28 has a first approximate hemispherical designating outer surface with an end face 28 which closes on the end face 21 of the chambers 20 formed openings 29. Radially inwardly lying, the cap 26 has spring arms 30 or a spring sleeve, which can be expanded radially outwardly / may under elastic bias and radially inwardly lying latching or locking elements 31 which due to the elasticity of the spring arm 30 in the in Fig. 1st Engage position shown in the groove 27. For the alternative embodiment of a handle 10 shown in FIG. 3, the chambers 20 have a radially curved longitudinal axis 33 and an increasing radial extent in the direction of the center of the chambers 20. The openings 29 are closed in this case with a circular disk 34 which is plugged onto the extension 17. For producing the cap 26, the grip core 13 and the grip shell 18 are inserted into an injection mold, in the cavities of which a cavity for the cap 26 remains free, which is filled during the injection of the plastic compound for the cap 26. Due to the buildup of pressure during the injection of the plastic compound, the annular disc 34 is pressed against the end face 21. The cap 26 is connected in this case cohesively to the extension 17 and the circular disk 34. Preferably, the annular disk 34 is made of plastic. The annular disk 34 may be configured, for example, in handles 10 of a screwdriver for different types of screwdrivers in different colors, so that the annular disc 34 serves as a color coding. In this case, the annular disk 34 extends to the lateral surface 19 of the handle 10 (see upper half plane of FIG. 3), while otherwise the annular disk 34 may be radially outwardly overmoulded by the material of the cap 26 (see lower half plane of FIG. 3). In Fig. 3, an annular groove 43 can be seen, with which the hollow chambers 20 are connected to each other, for example, for a pressure equalization of a arranged in the chambers 20 gel.

For the illustrated in Fig. 4 alternative embodiment of the invention, the inner region 24 is formed stepwise in the circumferential direction. The grip shell 18 has in the region of an inner circumferential surface radially inwardly directed projections 35 or ribs, the play in the circumferential direction receiving record in corresponding to the projections 35 in cross-section formed recesses 36 or grooves. Between the radially inner end face of the projections 35 and the bottom of the recess 36 a clearance 37 is provided, while between the inner circumferential surface of the grip 18 and the outer circumferential surface of the handle core 13, a game 38 is provided. In the event that the games 37, 38 are the same size, the games with a deformation of the grip shell 16 can be overcome simultaneously, whereby a stiffness increase against a radial compression of the handle 10 can be given constructive. In the case of the games 37 and 38 are formed differently, a non-linear increase in stiffness can be achieved. Handle shell 18 and handle core 13 have with the projections 35 and recesses 36 a kind of internal toothing with a rectangular profile and a corresponding external toothing. In the circumferential direction, the aforementioned teeth abut each other with a sliding fit. It is advantageous in this embodiment that increases with an increase in the contact pressure of the hand on the handle 10, the contact surface between the two aforementioned teeth, so that the torque can be transmitted via the contact force of the hand-dependent contact surfaces.

Fig. 5 shows a rear view of the handle 10 without cap 26, in which the end face 21 is visible. For the embodiment shown in Fig. 5, the chambers 20 are approximately half formed by an approximately semicircular radial recess 39 of the inner circumferential surface of the handle shell 18, while the other half of the chamber 20 of a cross-sectionally approximately semicircular recess 40 or groove of the Jacket surface 16 of the handle core 13 is formed. The cross-sectional profiles of the recesses 39 and 40 may of course also have other shapes than those shown.

For the embodiment shown in Fig. 6, the handle core 13 is formed at least in the illustrated cross section with a uniform hexagonal outer contour. The outer region 23 is bounded radially inwardly by an approximately circular inner contour 41. Six rectilinear webs 22 with wall thickness constant in the illustrated cross-section adjoin in a middle region 42 directly to the lateral surface 16 of the hexagonal-shaped grip core 13, cross over in the corner regions of the lateral surface 16 with adjacent webs 22 and extend up to their end regions the inner contour 41, where the webs 22 are materially and integrally connected to the outer region 23. For this embodiment, resulting chambers 20a, 20b with different cross-sectional contour, namely chambers 20a, the cross section is to be referred to in a first approximation as triangular, and chambers 2Ob ₁ whose cross section is to be referred to in a first approximation as trapezoidal. The wall thicknesses of the webs can also vary over their extension in the longitudinal direction and / or in the radial direction, as well as the arrangement to each other.

According to the embodiment shown in Fig. 7, the handle 10 has only a single, but in this case circumferential in the circumferential direction chamber 20. The handle shell 18 is made in the form of a sleeve extra than an injection molded part. The inner contour of the grip shell 18, for example, for a grip core 13 with ribs 25, is formed by a casting core, which is pulled out of this after curing of the grip 18. Furthermore, the inner contour has a radial bulge, which limits the chamber 20 radially outward. The elasticity of the grip 18 can be a pulling of the core for the Make possible the formation of the bulge, by expanding the handle shell 18 with a pull of the casting core.

The grip casing 18 is attached to the handle core 13 in a subsequent assembly step, wherein ribs 25 of the handle core enter into the corresponding recesses of the grip shell 18, so that between the handle core 13 and handle shell 18, the transmission of torque is enabled. At the end face 21 facing the cap 26, the grip jacket 18 has a spur toothing 45 extending over part of the diameter.

After attaching the grip shell 18 on the handle core 13, the parts are inserted into a further shape and fill this shape except for a cavity that corresponds to the shape of the cap 26 to be produced. When the plastic is injected into this cavity, a material connection of the cap 26 occurs both to the grip shell 18 and to the grip core 13. For this purpose, the handle core on the extension 17 with the annular groove 27, so that on the cap 27 and the handle shell 18 is fixed in the axial direction. At the same time, in addition to a transmission via the ribs 25, a torque is transmitted via the spur toothing 45 via the cap 26 into the grip core 13.

The handle core 13 is preferably made of a hard material such as hard plastic, wood, metal or aluminum and has a smaller diameter than the handle core 13 of known 2-component handles. The chambers 20 may be slightly tapered to facilitate removal of the cores. For chambers 20 with variable cross section, it is advantageous if the cross section of the chamber 20 in the region of the largest handle diameter is largest and decreases towards smaller handle diameters. In a modification of the embodiment shown in Fig. 5, the hollow chambers 20 may also be formed only in the form of a recess 39 from the handle shell 18 or in the form of only one recess 40 from the handle core.

To produce the handle 10, the handle core 13 is produced in a first production manner in a first injection mold, which is then inserted into a second injection mold, in which then the handle shell 18 is sprayed onto the handle core 13. Casting cores, in particular slides with core pins, in this case form the chambers 20. In a second method of manufacture, the grip jacket 18 is made separately from the handle core 13 and pushed axially onto the handle core. Handle core 13 and handle shell 18 are preferably glued together. In the grip casing 18, the chambers 20 are formed or corresponding grooves. Under certain circumstances, these grooves can complement each other with grooves in the handle core 13 to form larger chambers.

The length of the chambers 20 preferably corresponds approximately to at least the width of the handle 10 enclosing hand. The chambers 20 are disposed radially inwardly of the surface of the handle 10 surrounded by the surface of the user.

In the event that the cap 26 is not materially connected to the rest of the handle 10, the cap is preferably rotatable, wherein the cap 26 bears under axial load on the end face 21, while between the groove 27 and the latching or locking element 31st and radially inner end surfaces of the cap 26 and the end surface of the extension 17 remains a slight axial play.

Notwithstanding the illustrated embodiments, it is also possible that a plurality of chambers 20, in particular with a reduced radial extent, are arranged one behind the other in the radial direction or offset relative to one another.

FIG. 8 shows an embodiment which, unless otherwise stated, essentially corresponds to the embodiment according to FIG. However, in this case, the radially inner boundary of the chamber 20 is approximately rectilinear, while the radially outer boundary of the chamber 20 is curved more towards the outside in comparison to FIG. This has the consequence that decreases in the direction of the center of the longitudinal extent of the chamber 20, the wall thickness of the outer region 23 and a minimum reaches approximately in the range of the maximum diameter of the handle 10. As a result of a reduced wall thickness thus a large radial elasticity can be achieved.

9 shows a further exemplary embodiment of a screwdriver 11 with a handle 10, in which only one circumferential chamber 20 and extending approximately over half to two-thirds of the longitudinal extension of the handle 10 extending chamber 20 is provided. For this embodiment, the chamber 20 as a filling 46 with an elastic material at least partially, here completely filled. The filling 46 is preferably a soft plastic, which may have a porous or a closed structure. In particular, the filling 46 has a hardness in the range of 10 to 50 Shore A, wherein the hardness of the plastic may also vary, for example in the longitudinal direction or in the radial direction. The basic idea of an arrangement of an elastic material can also be applied to the embodiments illustrated in FIGS. 1 to 7, in particular to a plurality of chambers distributed in the circumferential direction.

A production of a handle 10 for a screwdriver 11 with at least one chamber 46 provided with a filling 46 is possible, for example, as follows:

a) For a first embodiment, the filling 46 is first applied to the Griffkem 13. This can in particular by spraying the filling 46 on the

Handle core 13 in a shape with the outer contour of the filling made or by separate production of the filling 46 and arrangement of the filling 46 in the solid state on the handle core 13, wherein a frictional or positive connection, the filling 46 can secure relative to the handle core 13. In a subsequent method step, the grip core 13 is inserted into a suitable mold with the filling 46 arranged thereon, and the grip jacket 18 is injected around the grip core 13 and the filling 46, thereby ensuring, in particular, a cohesive connection between the grip jacket 18 and the filling 46.

b) For an alternative manufacturing process, first the grip jacket 18 is sprayed onto the casting core using cores to form the chambers 20, as has already been explained above. After removing at least one core from the interior of the grip shell 18 and from the at least one chamber 20, the filling 46 is introduced into the at least one chamber 20. Preferably, the filling 46 is injected into the chamber 20 in the form of a soft plastic.

In contrast to the embodiment shown in FIG. 9, the filling 46 can extend only over a partial region of the at least one chamber 20. For example, the filling 46 may be formed as centrally arranged with respect to the longitudinal extension of the handle 10, radially oriented web or circumferential collar. It is also conceivable to form a radial gap between the filling 46 and the gripping jacket 18, so that the gripping jacket 18 only after being predetermined by the gap height elastic deformation to rest against the Fill 46 comes. To bring about the desired anisotropy of a high elastic compliance in the radial direction, but high rigidity in the circumferential direction contact surfaces between handle shell 10 and filling 46 may be formed larger in the circumferential direction than those in the radial direction, see. Also, Fig. 4. Also conceivable is the use of a composite material for the filling 46, for example, the injection of soft plastic into the chambers 20, if in these already stiffening elements are arranged.

10-12 show a further embodiment of a handle according to the invention 10. For this embodiment, the part of the handle core 13 having a cylindrical outer surface, which is surrounded by the grip shell 18, radially outwardly oriented webs 22. According to FIG around six evenly distributed over the circumference webs. The lateral surface 19 is formed with end faces 47 of the webs 22 extending in the direction of the longitudinal axis 14-14 of the handle 10. The end areas 47 of the webs 22 assigned to the end areas 47 are connected to one another via transition areas 48, the transition areas 48 having a constant wall thickness which is smaller than the wall thickness of the webs 22. In the cross section illustrated in FIG. 11, the transition areas are "pillow-like" and arcuately curved by the webs 22 outward. The chambers 20 are radially inwardly limited by the cylindrical surface of the handle core 13, in the circumferential direction of the webs 22 and radially outboard of the transition areas 48. For the illustrated embodiment, the handle core 13 is integrally formed with the "cap", so that the handle core 13th roughly as in the cross section "double-T-shaped" or "bone-shaped" is to call. The arranged in the chambers 20 material can be injected into a suitable shape with an inner contour corresponding to the inner contour of the transition regions 48. Following this, the material for the transition areas 48 can be injected into a different shape with an inner contour corresponding to the outer contour of the transition areas 48. The material of the transition regions and preferably also of the webs 22 is stiffer than the material arranged in the chambers 20.

As can be seen from FIG. 12, the end faces 47 of the webs 22 do not extend over the entire longitudinal extent of the lateral surface 19. Rather, in a front region 49 and a rear region 50, the lateral surface 19 is circumferentially formed circumferentially with the material of the transitional regions 48 , The end faces 47 of the webs 22 extend over the region of the handle in which this has the largest diameter and on which the palm of a user mainly rests. By the circular Bulges of the transition regions 48 in cross-section to the outside are formed pillow-like elevations, which largely continue in the direction of the longitudinal extent of the lateral surface 19 of the handle 10. The aforementioned pillow-like elevations are deformed radially inwardly upon application of manual forces.

In the figures, corresponding reference numerals have been used for different embodiments of the invention for comparable components.

Of course, the handle cross-sectional contour may also be different than the hexagon contour shown in the example. For example, it may also be a substantially round, four-edged, octagonal or oval contour. The arrangement of the chambers in the circumferential direction can then also be different than in the illustrated exemplary embodiments and be carried out in such a way that the desired radial elasticity is achieved.

LIST OF REFERENCE NUMBERS

Handle 20 chamber

Screwdriver 21 front side

Function part 22 bar

Handle core 23 Outer area

Longitudinal axis 24 inner area

Section 25 rib

Lateral surface 26 cap

Extension 27 groove

Grip 28 end face

Lateral surface 29 opening

Spring arm 40 recess

Latching or blocking element 41 inner contour

Recess 42 Middle area

Longitudinal axis 43 annular groove

Annular ring 44 outer contour

Projection 45 spur toothing

Recess 46 filling

Game 47 faces

Game 48 transition area

Recess 49 front area

the backstage area

Claims

First handle (10) for a screwdriver, a screw clamp or other device with which a force exerted on the outer surface of the handle by the user torque to a arranged in the handle output member is transferable, with a) an outer region (23) and an inner region (24), b) the outer region (23) having a lateral surface (19) and having an elastic material with a first stiffness, c) the inner region (24) uniformly distributed over the circumference chambers (20) or a circumferential circumferential chamber having a second stiffness, wherein the second stiffness is smaller than the first stiffness, and d) a dimensioning and selection of the stiffness is such that da) upon application of the handgrip (10) with forces of the user's hand the outer region (23) can be deformed radially inwardly and, with this deformation, deformation of at least one chamber (20) can also be brought about and db) acting in the circumferential direction on the handle forces are transmitted as torque.

2. Handle according to claim 1, characterized in that a dimensioning and selection of the stiffness is such that the rigidity of the handle in the radial direction is smaller than the rigidity of the handle in the circumferential direction.

3. Handle according to claim 1 or 2, characterized in that the at least one chamber (20) is designed as a hollow chamber.

4. Handle according to claim 1 or 2, characterized in that the at least one chamber (20) are formed as partially or completely filled with a liquid or gel hollow chamber.

5. Handle according to claim 1 or 2, characterized in that the at least one chamber (20) is partially or completely filled with soft plastic.

6. Handle according to one of the preceding claims, characterized in that extending the at least one chamber (20) approximately in the direction of the longitudinal axis (14-14) of the handle (10).

7. Handle according to claim 6, characterized in that the at least one chamber (20) is approximately rectilinear.

8. Handle according to claim 6, characterized in that the at least one chamber (20) has a curvature in the radial direction.

9. Handle according to claim 8, characterized in that the curvature of the curvature of the outer contour (44) of the handle (10) deviates.

10. Handle according to claim 8, characterized in that the curvature corresponds approximately to the curvature of the outer contour (44) of the handle (10).

11. Handle according to one of the preceding claims, characterized in that the at least one chamber (20) has over the longitudinal axis (33) largely constant cross-section.

12. Handle according to one of the preceding claims, characterized in that the at least one chamber (20) over the longitudinal axis (33) has a variable cross-section.

13. Handle according to one of the preceding claims, characterized in that the inner region (24) with the at least one chamber (20) in a radial transition region between a handle core (13) and a handle shell (18) is formed.

14. Handle according to one of the preceding claims, characterized in that the chambers (20) in the circumferential direction via webs (22) are separated from each other.

15. Handle according to claim 14, characterized in that the webs (22) are oriented radially.

16. Handle according to claim 14, characterized in that the webs (22) in the cross section of the handle (10) relative to a radial orientation at an inclination angle α are inclined.

17. Handle according to claim 16, characterized in that webs (22) different inclination angle α are present.

18. Handle according to one of the preceding claims, characterized in that the at least one chamber (20) in a handle core (13) and / or handle shell (18) is formed and at least one opening (29) through an end cap ( 26) or at least one closing element (annular disk 34) closing the openings (29) is closed.

19. Handle according to claim 18, characterized in that the cap (26) at least one of the openings (29) closing closure element (circular disk 34).

20. Handle according to claim 18 or 19, characterized in that the cap (26) is rotatable.

21. Handle according to one of claims 18 to 20, characterized in that the cap (26) is connected via a positive connection.

22. Handle according to one of claims 18 to 20, characterized in that the cap (26) is connected via a cohesive connection.

23. Handle according to any preceding claims 5 to 22, characterized in that the at least one chamber (20) is filled with a soft plastic having a hardness of 10 to 45 Shore A.

24. Handle according to any preceding claim, characterized in that the outer region (23) with a soft plastic having a hardness of 40 to 105 Shore A, in particular a hardness of 50 to 85 Shore A, is formed.

25. Handle according to one of claims 1 to 23, characterized in that the outer region (23) with a soft plastic having a hardness of 30 to 105 Shore A, in particular a hardness of 30 to 85 Shore A, is formed.

26. Handle according to one of the preceding claims, characterized in that the chambers (20) in the circumferential direction by radial webs (22) are limited and radially outwardly by the transition areas (48) formed with the lateral surface (19).

27. Handle according to claim 26, characterized in that the lateral surface (19) with the radially outer end faces (47) of the webs (22) is formed and between these end faces (47) with bridging regions (48).

28. Handle according to claim 27, characterized in that the webs (19) and the bridging regions (48) are formed with the same material.

29. Handle according to claim 27, characterized in that the webs (19) and the bridging regions (48) are formed with different materials.

30. Handle according to claim 28 or 29, characterized in that the webs (19) are formed integrally with the handle core (13).

31. Handle according to one of claims 26 to 30, characterized in that an approximately central region of the lateral surface (19) of the handle (10) in the circumferential direction alternately with the end faces of the webs (19) and the transition regions (48) is formed and this A front region (49) in the direction of the longitudinal axis (14-14) of the handle (10) is arranged upstream of the central region, in the region of which the transition regions extend over the entire circumference of the lateral surface (19) of the handle (10).

32. Handle according to one of claims 26 to 31, characterized in that an approximately central region of the lateral surface (19) of the handle (10) in the circumferential direction alternately with the end faces of the webs (19) and the transition regions (48) is formed and this central region a rear region (50) in the direction of the longitudinal axis (14-14) the handle (10) is arranged downstream, in the region of which the transition regions extend over the entire circumference of the lateral surface (19) of the handle (10).

33. A method for producing a handle (10) for a screwdriver, a screw clamp or other device, with which a force exerted on the lateral surface of the handle by the user torque to a arranged in the handle output member is transferable, in particular for producing a handle after one of claims 1 to 32, comprising the following method steps: a) producing a grip core (13), b) arranging casting cores oriented substantially in the direction of a longitudinal axis and distributed around the longitudinal axis in the circumferential direction or arranging a casting core which runs circumferentially in a mold c) sheathing the casting cores or the casting core with a grip shell (18) in an injection molding process, d) removing the casting cores or the casting core by moving at least one casting core in the direction of an end face (21) of the grip shell (18), whereby at least one chamber ( 20) is released, the one opening (29) in the area e) at least partially closing the at least one chamber (20) or opening (29).

34. The method according to claim 33, characterized in that the closing of the at least one opening (29) with a closure element (annular disc 34) or a cap (26).

35. The method according to claim 33, characterized in that the closing of the at least one chamber (20) takes place by at least partially filling the chamber (20) with a material whose stiffness is smaller than the rigidity of the grip jacket (18).

36. The method according to any one of claims 33 to 35, characterized in that in the method step b) the at least one casting core with the handle core (13) is inserted into the mold and with the production of the grip shell in an injection molding a cohesive connection of handle core ( 13) and handle shell (18) is produced.

37. The method according to claim 34 or 36, characterized in that after removal of the at least one casting core grip core (13) and grip shell (18) with at least one closure element (annular disk 34) for the openings (29) of the chambers (20) in one Form are inserted and in an injection molding process, the cap (26) is materially connected to the handle core (13) and / or handle shell (18).

38. The method of claim 34 or 36, characterized in that after removal of the at least one casting core handle core (13) and handle shell (18) form or frictionally connected to a cap (26) are connected.