Hand-held tool and method for producing such a hand-held tool

Abstract

A hand-held tool comprises a tool part and a handle surrounding a section of the tool part and connected to same in a torque-transmitting manner. The tool part comprises a connection contour used to connect the handle in a torque-transmitting manner at least in some areas, in a section surrounded by the handle. The handle comprises an inner handle piece which can be connected to the connection contour and surrounds same in a torque-transmitting manner. With the inner handle piece slid onto the connection contour, one or more outwardly-open casting channels are provided between the two parts. The handle further comprises an outer handle piece made of plastic, which during the course of a plastic moulding process is moulded around the unit comprising the tool part which has an inner handle piece connected to the connection contour thereof, wherein the at least one casting channel is at least partially filled with the plastic material which forms the outer handle piece. A method is also described for producing such a hand-held tool.

Claims

1. A hand-held tool comprising: a tool part and a handle surrounding the tool part, the handle connected to the tool part in a torque-transmitting manner; the tool part has a connection contour for the torque-transmitting connection to the handle at least in a section of the tool part surrounded by the handle, the connection contour having ribs which project outward and extend longitudinally along the connection contour, with casting channels open in a radial direction thereby provided between the ribs; the connection contour being a plastic part injection-molded around the section of the tool part and connected thereto in a torque-transmitting manner; the handle comprising an inner handle piece and an outer handle piece; the inner handle piece has an interior cavity which extends into the inner handle piece in a longitudinal direction, and the connection contour is arranged within said interior cavity and surrounded by the inner handle piece in a torque-transferring manner thereby forming a unit, wherein the casting channels provided between the ribs of the connection contour are closed in a radial direction by surfaces of the inner handle piece which surround the connection contour in the interior cavity of the inner handle piece; the outer handle piece made of a plastic material and formed around the unit consisting of the tool part with the inner handle piece arranged on the connection contour during a plastic molding process, wherein the plastic material of the outer handle piece extends through the casting channels provided between the connection contour and the inner handle piece and thereby permanently connects the inner handle piece to the connection contour of the tool part.

2. The hand-held tool of claim 1, wherein the inner handle piece is a plastic part produced in a tool separately from the production of the connection contour and the outer handle piece, and the inner handle piece is not injection-molded around the connection contour.

3. The hand-held tool of claim 1, wherein a cross section of the connection contour is constructed as a polygonal contour defined by a jacket surface, with free ends of the ribs of the connection contour terminating along the jacket surface and areas of the connection contour between the ribs receding from the jacket surface that surrounds the connection contour, wherein the inner handle piece does not engage or only partially engages said areas, and each of the areas forms one of the casting channels.

4. The hand-held tool of claim 1, wherein the inner handle piece is fixed on the connection contour by at least one catch.

5. The hand-held tool of claim 4, wherein an outer side of the connection contour carries the at least one catch which engages into a catch recess of the inner handle piece when the inner handle piece is slid onto the connection contour.

6. The hand-held tool of claim 1, wherein at least one outer surface section of the inner handle piece simultaneously forms an area of the outer surface of the handle of the hand-held tool.

7. The hand-held tool of claim 6, wherein an edge of the at least one outer surface section of the inner handle piece is formed by a sealing lip, the sealing lip configured to rest on the inner mold cavity of a molding tool during a plastic molding process for producing the outer handle piece.

8. The hand-held tool of claim 6, wherein the at least one surface section of the inner handle piece comprises a soft coating.

9. The hand-held tool of claim 6, wherein the least one surface section of the inner handle piece comprises one or more perforations filled with the material of the outer handle piece.

10. The hand-held tool of claim 9, wherein the one or more perforations are designed as writing and/or as a logo.

11. The hand-held tool of claim 1, wherein the hand-held tool is a screwdriver.

12. The hand-held tool of claim 11, wherein the screwdriver carries several rotary cam beads arranged circumferentially distributed on the outside of the handle, wherein at least a few of the rotary cam beads are inclined at least in sections opposite the longitudinal axis (L) of the handle extending in the direction of the blade of the screwdriver counter to the direction of screwing in, and that said rotary cam beads comprise a positioning surface on their side facing counter to the direction of screwing in, the positioning surface inclined at a slight angle opposite the jacket surface surrounding the handle.

13. A method for producing a hand-held tool with a tool handle connected to a tool part, comprising the following steps: molding a connection contour made of plastic around a section of the tool part, the connection contour having an outer rotary cam contour and casting channels open to the outside; sliding an inner handle piece onto the connection contour, the inner handle piece surrounding the connection contour in a torque-transmitting manner; and molding an outer handle piece made of plastic in a molding tool onto the inner handle piece located in the molding tool and connected to the connection contour, whereby the casting channels between the inner handle piece and the connection contour are at least partially filled with plastic provided for forming the outer handle piece, and therefore the inner handle piece is permanently connected to the connection contour.

14. The method of claim 13, wherein the connection contour and the outer handle piece are produced in a following plastic molding tool in successive steps, in contrast to the inner handle piece which is produced in a separate molding tool and is connected to the connection contour before the step of molding the outer handle piece.

15. The method of claim 13, wherein the inner handle piece is produced in a tool separately from the step of molding the connection contour around the tool part, and the inner handle piece is not injection-molded around the connection contour.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure is further described below with reference to the attached figures:

(2) FIG. 1 shows a screwdriver comprising a tool part and a handle in a perspective view;

(3) FIG. 2 shows the tool part of the screwdriver of FIG. 1 without the handle, with a connection contour arranged on it;

(4) FIG. 3 shows a front side perspective view of the connection contour of the tool part of FIG. 2;

(5) FIG. 4 shows a perspective view of an inner handle piece used to form the handle of the screwdriver of FIG. 1;

(6) FIG. 4a shows an enlarged partial section view of the inner handle piece of FIG. 4;

(7) FIG. 5 shows a perspective view into an inner rotary cam contour of the inner handle piece of FIG. 4;

(8) FIG. 6 shows a rear side perspective view of the inner handle piece shown in FIG. 4;

(9) FIG. 7 shows an enlarged view of a section from the handle of the screwdriver of FIG. 1; and

(10) FIG. 8 shows a schematic partial section view through the handle along the line A-B in FIG. 7.

(11) Before explaining the selected embodiments, it is to be understood that the present disclosure is not limited in application to the details of the particular arrangements shown and is capable of other embodiments. While certain embodiments are illustrated in reference to the figures, it is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting. Also, the terminology used herein is for the purpose of description and not of limitation.

DETAILED DESCRIPTION

(12) As seen in FIG. 1, screwdriver 1 as a hand-held tool comprises a tool part 2 and a handle 3. The tool part 2 is the blade of the screwdriver 1 which carries a rotary cam contour 4 on its free end. In the depicted embodiment, the rotary cam contour 4 is designed as a cross contour so that a cross-slot screw (not shown) can be activated with the screwdriver 1.

(13) The handle 3 of the screwdriver 1 is composed of several components. In the depicted embodiment, the handle 3 consists of two components, namely an inner handle piece 5 and an outer handle piece 6. Since the inner handle piece 5 forms, in part, the outer surface of the handle 3 of the screwdriver 1 in the depicted embodiment, this component is visible in FIG. 1. The inner handle piece 5 is produced in the depicted embodiment from a plastic with a greater degree of hardness according to Shore than the outer handle piece 6.

(14) FIG. 2 shows the tool part 2 of the screwdriver 1. The end section of the tool part 2 opposite the rotary cam 4 is provided with a connection contour 7. In the depicted embodiment, the connection contour 7 is molded around this end of the tool part 2 which is flattened like a spatula for this purpose. The connection contour 7 is constructed as a polygon, wherein it is designed so that the inner handle piece 5 can be connected to it in a torque-transmitting manner. The connection contour 7 comprises several ribs following the longitudinal extension of the tool part 2. A catch 8 is seated on each of two ribs 9 which diametrically oppose one another. The catches 8 are made of the same plastic material as the other components of the connection contour 7. The perspective view onto the back side of the connection contour 7 in FIG. 3 more clearly shows the cross-sectional geometry of the connection contour 7. The actual connection contour 7 is a polygonal contour surrounding the individual ribs (which is sketched in in dotted lines in the figure for emphasizing the geometry). In the depicted embodiment, the jacket surface 10 virtually surrounding the connection contour 7 is designed as a regular hexagon. The ribs 9 carrying the catches 8 comprise a flat side for carrying the catches 8. In respect to the hexagonal jacket surface 10 of the connection contour 7, casting channels 11 along the longitudinal extension of the connection contour 7 are provided (only a few are identified in FIG. 3 with lead lines and this reference numeral for illustration). The casting channels 11 are located between the ribs. The casting channels 11 are open on the end even when the inner handle piece 5 has been slid onto the connection contour 7.

(15) In the direction of the rotary cam contour of the tool part 2, the connection contour 7 ends in a plate 12.

(16) In the depicted embodiment, the tool part 2 comprises the blade produced from a tool part, the rotary cam contour 4 and the connection contour 7 molded on it.

(17) In order to produce the handle 3, the inner handle piece 5 shown in FIG. 4 has a contour complementary to the hexagonal connection contour 7 of the tool part 2 which is slid onto the connection contour 7. FIG. 5 shows a look into the rotary cam contour 12 of the inner handle piece 5, which contour 12 has a shape like a casing complementary to the connection contour 7. This shape of the rotatory cam contour 12 is also hexagonal, as can be clearly recognized from FIG. 5. Perforations 14 are introduced into the side surfaces 13 of this rotary cam contour 12. The surfaces of the perforations 14 rest on the exterior side surfaces of the ribs 9 at the positions corresponding to the catches 8 (see also FIG. 4). The catches 8 snap into these perforations 14 when the inner handle piece 5 has been slid sufficiently far onto the connection contour 7. This occurs when the front side of the inner handle piece 5 rests on the side of the plate 12 facing the connection contour 7.

(18) As seen in the depicted embodiment in FIG. 4, parts of the outer surface of the inner handle piece 5 form the outer surface of the handle 3 of the screwdriver 1. These outer surface sections 15 of the inner handle part 5 form a certain number of fields on the outside of the handle 3. The areas of the inner handle piece 5 which form these fields of the handle 3 are separated from each other so that the outer handle piece 6 can be formed between these fields. During the later construction of the outer handle piece 6, the recesses present on the inner handle piece 5 are filled with a plastic mass opposite the outer side of the areas of the inner handle 5 forming the fields. The areas forming the fields are constructed as hollow bodies, as is apparent from the view of the back side of the inner handle piece 5 in FIG. 6. In the depicted embodiment, the hollow body forming at least one field is provided with perforations in order to show the word WITTE and a logo. These perforations are also filled with the plastic mass in the following step of forming the outer handle piece 6. Since the color of the plastic forming the outer handle piece 6 differs from the color of the inner handle piece 5, the writing and the logo are then clearly apparent.

(19) To prevent coating the outer surface 15 of those areas of the inner handle piece 5 with the plastic mass used for the production of the outer handle piece 6, these areas of the inner handle piece 5 are limited or surrounded circumferentially by a sealing lip 16. FIG. 4a shows an enlarged view of an edge formation in the transition from a surface area 15 of the inner handle piece 5 forming the outer surface of the handle 3 to an adjacent area which is to comprise the outer handle piece 6. The sealing lip 16 is located at the border between these two areas. The sealing lip 16 is a thin continuation of material which extends a few tenths of a millimeter over the surface 15. During the production of the outer handle piece 6, the sealing lip 16 acts d against the inner wall of the mold cavity in which the outer handle piece 6 is molded.

(20) A symbol 17 visually indicating the type of the rotary cam contour 4 is also part of the inner handle piece 5, as is apparent from FIG. 6. Since the rotary cam contour 4 is a cross contour, the symbol 17 is also designed as a cross. The outer surface of the symbol 17, which can be recognized in FIG. 6, is not sprayed over by the plastic mass used to produce the outer handle piece 6. The outer surface of the symbol 17 is also provided with a circumferential sealing lip facing in the radial direction, such as was previously described on the surface areas of the inner handle piece 5 with respect to sealing lip 16.

(21) To form the outer handle piece 6, the tool part 2 (with the inner handle 5 slid onto its outer contour 7) is placed in a plastic molding tool. The mold cavity of this tool corresponds to the outer form of the outer handle piece 6 to be produced. Since three surface areas 15 of the inner handle piece 5 are circumferentially distributed with the same angular distance from each other in the depicted embodiment, which three surface areas 15 are not to be coated with the plastic mass forming the outer handle piece 6 and are each limited by a circumferential sealing lip 16 facing outward in a radial direction, the sealing lips act against the inner wall of the mold cavity under a certain prestress. This configuration centers the arrangement of the inner handle piece 5 with the tool part 2 connected to it inside the mold cavity. Therefore, additional centering measures are basically unnecessary in such an embodiment.

(22) The hollow spaces remaining in the tool cavity, which include the hollow spaces inside the inner handle piece 5 and the casting channels 11 between the inner handle piece 5 and the connection contour 7, are completely filled by the plastic mass introduced into the molding tool for molding the outer handle piece 6. Therefore, the plastic mass for forming the outer handle shell 6 is also used to connect the inner handle piece 5 to the connection contour 7 of the tool part 2.

(23) In a further embodiment not shown in the figures, an insulation is provided on the connection contour of the tool part extending to its rotary cam contour.

(24) Surface area 15 formed by the inner handle piece 5 (recognizable in FIG. 1 and shown on an enlarged scale in FIG. 7) carries a rotary cam bead 18 having its longitudinal extension, indicated by the writing WITTE, running inclined relative to the longitudinal axis L of the handle 3. The inclination takes place in a direction in which the closure facing the tool part 2 is inclined counter to the direction of screwing in (rotating to the right). The longitudinal axis L is sketched into the handle 3 in dotted lines in FIG. 7. The rotary cam bead 18 in the depicted embodiment is introduced through a first recess 19 and a second recess 20 in the outer jacket surface of the screwdriver handle 3. This means that the outer flat side 21 of the rotary cam bead 18 corresponds in its course to the outer, surrounding jacket surface of the handle 3. Therefore, the rotary cam bead 18 does not project over the usual jacket surface of the handle 3 in the embodiment shown. The handle 3 is designed in the shape of a barrel in a side view. The rotary cam bead 18 is located in the area of the greatest bulging out of this barrel shape. In the circumferential direction around the barrel shape, the jacket surface of the handle 3 in the area of the rotary cam bead 18 comprises three cycloidal arches having a greater radius of curvature which are connected by crown sections having a smaller radius of curvature. The crowns with the smaller radii of curvature are made available by the outer handle piece 6. Therefore, these crowns, of which one is designated with the reference numeral 22 in FIG. 7, extend parallel to the longitudinal axis L of the handle 3 adjacent to the inclined rotary cam beads 18.

(25) A positioning surface 23 facing counter to the direction of screwing in is made available by the recess 19. If a rotary moment is exerted on the handle 3 by a hand surrounding the handle 3, a part of the torque acting on it is brought into a moment directed in the direction of the rotary cam contour 4 on account of the alignment of the positioning surface 23 inclined relative to the longitudinal axis L. The depth line 24 of the recess 19 merges at both ends into the adjacent handle surface. This has the consequence that the positioning surface 23 successively increases from its end facing away from the tool part 2 toward its other end. The recess 19 itself is V-shaped in its cross-sectional geometry, as is schematically shown in FIG. 8. The opening angle of the flanks of the recess 19 is slightly more than 160.

(26) The torque bead 18 is limited in its screwing-in direction by the recess 20. A second positioning surface 25 is formed by the recess 20 and faces counter to the direction of screwing in. When a torque is applied onto the handle 3 by the hand of a user, not only is a rotary movement transferred onto the handle 3 by the recesses 19, 20 and the positioning surfaces 23, 25 formed as a consequence (for which the previously-described, longitudinally-axial rotary cam beads 18 also serve), but a part of the introduced moment is also diverted via both positioning surfaces 23, 25 in the longitudinal axial direction to the rotary cam contour 4, by which moment the screwdriver 1 quasi automatically follows the successive advance of a screw activated by the above, in any case as long as a torque is being applied.

(27) An embodiment that is not shown in the figures provides that only one of the two recesses shown in FIG. 7 is provided and, therefore, only one positioning surface is made available. An embodiment is also possible in which a rotary cam bead projects somewhat opposite the jacket surface of the other handle components.

(28) While a number of aspects and embodiments have been discussed, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations are possible. It is intended that the following claims are interpreted to include all such modifications, permutations, additions and sub-combinations, as they are within the true spirit and scope of the present disclosure and the claims. Each embodiment described herein has numerous equivalents.

(29) The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions to exclude any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Accordingly, it should be understood that although the invention has been specifically disclosed by selected embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims. Whenever a range is given in the specification, all intermediate ranges and subranges, as well as all individual values included in the ranges given are intended to be included in the disclosure. When a Markush group or other grouping is used herein, all individual members of the group and all combinations and sub-combinations possible of the group are intended to be individually included in the disclosure.

(30) In general, the terms and phrases used herein have their art-recognized meaning, which can be found by reference to standard texts, journal references and contexts known to those skilled in the art. The above definitions are provided to clarify their specific use in the context of the invention.

LIST OF REFERENCE NUMERALS

(31) 1 screwdriver 2 tool part 3 handle 4 rotary cam contour 5 inner handle piece 6 outer handle piece 7 connection contour 8 catch 9 rib 10 jacket surface 11 casting channel 12 rotary cam contour 13 side surface 14 perforation 15 outer surface 16 sealing lip 17 symbol 18 rotary cam bead 19 recess 20 recess 21 flat side 22 crown 23 positioning surface 24 depth line 25 positioning surface L longitudinal axis