EP0208942B1 - Handle - Google Patents

Abstract

A handle for tools, specifically for screwdrivers, is disclosed. The handle consists of two materials of different hardness, of which the harder material supporting the tool is incompressible under the forces occurring at operational load, whereas the other material permits slight elastic deformations under forces of load. In order to obtain a hand-sympathetic design which nevertheless transmits high torques, the two gripping zones of softer material are situated adjacent to a gripping zone of harder material located between them.

Description

The invention relates to a booklet for tools, in particular screwdrivers, according to the preamble of claim 1.

A booklet of this kind is known from US-A-2,871,899 and JP-A-60-2271. There the outer surface of the booklet, viewed in the longitudinal direction of the booklet, has grip zones of harder and softer material one behind the other. This is achieved by sheathing a partial length of the cylindrical stapling body with the soft body, whereby the tool-side end area, which makes up about a third of the total length, is exposed as a harder gripping zone. To secure the applied sleeve-like sheath against rotation, it engages with corresponding axially aligned projections in corresponding grooves of the stitching core. Such equipment made of rubber-like material, which can be viewed practically as a full covering, is disadvantageous in terms of handling; it turns out to be too "spongy". Especially when used continuously, wrinkles and increased static friction cause redness or even inflammation on the operating hand. The tool is not suitable for continuous use. The short, harder gripping zone is also reduced in diameter and is mainly used for the so-called "twine", ie for the initial penetration of the screws under low load. The application of a higher torque, however, is reserved for the area of the softly covered booklet end.

From DE-B 1 298 060, on the other hand, a screwdriver handle is known, which is specially designed from the point of view of the application of a high torque, that is to say that the handle can be stored well in the operating hand. The individual fillets, which are distributed around the circumference of the stitching body and are angled in this direction, allow a secure clamping grip.

The object of the invention is to design a generic tool in a technically simple, advantageous manner in such a way that high torques can be transmitted on the one hand, but on the other hand the grip is significantly improved and, above all, more pleasant to the hand.

This object is achieved by the invention specified in claim 1.

The subclaims are advantageous developments of the booklet according to the invention.

As a result of such a design, a generic booklet of increased utility value is achieved: the operating hand does not lose the grip on the non-deformable material of the booklet. On the other hand, the proportion of area of softer material is reduced, so that the disadvantages shown practically no longer occur when used continuously; the balanced division brings on the one hand the desired grip-friendly insertion in the operating hand and on the other hand the possibility of applying higher torques. This is optimized by the further measure that the intermediate zone of harder material is that of the largest diameter and the adjacent grip zones of soft material are designed in the form of truncated cones tapering towards the ends of the booklet. There is a kind of barrel shape. The ring intermediate zone, which has the largest diameter and lies in the middle of the hand, is thus available as a hard surface for the application of a high torque; it has the largest lever length (rotationally symmetrical) and forms the stable guiding zone for the re-gripping; the axially adjoining grip zones, on the other hand, are elastically flexible. The screwing speed is also increased due to the smaller cross-sectional truncated cones; the so-called "twirling" can be used here. It also proves to be advantageous that the grip zones of softer material are interrupted in the circumferential direction by intermediate sections of harder material. In this regard, a uniform, balanced hard / soft distribution of the available gripping surface can be achieved. A structure which corresponds to the grip-friendly structure of the tool booklet according to DE-B 1 298 060 with the added advantage of improved grip results from the fact that the grip zones of softer material form individual fillets which extend into the intermediate zone. As a result, this intermediate ring zone embedded in the elastic grip mass like a wheel body is consequently also fully structurally included in the measure for achieving good grip. In this way, a polygon is practically achieved in the cross-sectional area of the individual fillets. In addition, it proves to be advantageous that the end face facing away from the blade is equipped with a spherical dome made of hard plastic. This allows leverage to be exerted on the exercise book without the risk of stressing the palm of the hand. There is also good anti-slip protection for the overlying hand cavity, while the other hand causes the "twisting". Such a crest, on the other hand, even tolerates hammer blows. As a result of the structural measure that an annular fillet likewise made of resilient material adjoins the section tapering on the blade side, a flexibility which favors the grip is also obtained in this area close to the blade. It is also favorable that both tapered grip zones are realized in the form of elastic sheaths around a hard plastic core. The deforming forces are therefore distributed over areas of the tool handle that are undercut by harder material. It is favorable that the coats are molded on and connected via tunnel-like openings in the intermediate zone. The fact that ring grooves are formed further in the end faces of the intermediate zone increases the connecting zone between the two types of material. The "joint", which is also offset in planes, brings an advantageously large material accumulation, so that it does not tearing or spreading of the two bonded materials forming the tool booklet occurs. The circular ring zone is better than or a polygonal ring zone, especially for larger booklets. If the former is present, the polygonal shape of the blade-side end region has the advantage that the filed booklet cannot roll away. In addition, it proves to be advantageous that the gripping zones are made of softer material than pads used in depressions of the base body consisting of harder plastic material. This type of division into individual bodies even opens up the possibility of using different degrees of softness, so that a very special or individual loading of the booklet can take place in each case. Changing degrees of hardness of neighboring soft cushions can also be used. A simple and at the same time durable fixation is achieved if the recesses have undercut side walls for holding the positively seated upholstery. If particularly soft upholstery material is used, additional securing by gluing can also be added. The boundary connections between soft and hard can be mitigated, above all, by the fact that the upper area of the upholstery overlaps the recess edge. It is practically mushroom-shaped upholstery. The upper side is convex. The upholstery occupies an exposed position in relation to the harder handle body. The skin of the operating hand only lies on the harder grip areas mainly when the protruding area is pressed in. Furthermore, the invention proposes that the cushions are inserted in the region of the individual hollow legs and that they form a top side that is designed to be concave in the direction of the throat and that is convex in the transverse direction. Accordingly, they are hollow back-like cushions on the outside, the back of which is arched. From a manufacturing point of view, it proves to be advantageous that the cushions are designed uniformly with one another. If it is a matter of shapes leaving the symmetrical structure, it is favorable that the mutually identical pads in the two truncated cones are inserted upside down; namely, they can increase in width in the direction of the intermediate zone of the booklet with a larger cross section.

• Fig. 1 einen mit dem erfindungsgemäßen Heft ausgestatteten Schraubendreher in Seitenansicht, und zwar gemäß dem ersten Ausführungsbeispiel,
• Fig. 2 den Heftbereich dieses Schraubendrehers im Längsmittenschnitt bei nur partieller Wiedergabe der Schraubendreherklinge,
• Fig. 3 den Schnitt gemäß Linie 111-111 in Fig. 2, und zwar in gegenüber Fig. 2 vergrößerter Wiedergabe,
• Fig. 4 bis 6 dieverse Varianten dieses Heftes,
• Fig. 7 einen mit dem erfindungsgemäßen Heft ausgestatteten Schraubendreher in Seitenansicht, gemäß dem zweiten Ausführungsbeispiel,
• Fig. 8 den Heftbereich dieses Schraubendrehers im Längsmittenschnitt,
• Fig. 9 den Schnitt gemäß Linie IX-IX in Fig. 8,
• Fig. 10 den Schnitt gemäß Linie X-X in Fig. 8, und zwar in gegenüber Fig. 8 vergrößerter Wiedergabe und
• Fig. 11 das bedienungsgerecht in einer Handhöhlung einliegende Schraubendreherheft.

The subject matter of the invention is explained in more detail below with the aid of two illustrative exemplary embodiments. It shows

• 1 is a side view of a screwdriver equipped with the handle according to the invention, specifically according to the first exemplary embodiment,
• 2 shows the stitching area of this screwdriver in the longitudinal center section with only partial reproduction of the screwdriver blade,
• 3 shows the section along line 111-111 in FIG. 2, namely in an enlarged representation compared to FIG. 2,
• 4 to 6 the reverse variants of this booklet,
• 7 is a side view of a screwdriver equipped with the handle according to the invention, according to the second exemplary embodiment,
• 8 shows the stitching area of this screwdriver in the longitudinal center section,
• 9 shows the section along line IX-IX in FIG. 8,
• Fig. 10 shows the section along line XX in Fig. 8, in comparison with Fig. 8 enlarged and
• 11 shows the screwdriver booklet lying in a hand cavity in a user-friendly manner.

A screwdriver blade 1 with a hexagonal cross section is incorporated into the illustrated base body K.

The screwdriver handle has at its blade end an annular groove 2 which ends in the end of the handle in a collar 3 which can be polygonal according to FIGS. 4 and 7.

The other end of the stitching body section which attaches to the ring fillet 2 is designed in a modification of a basic barrel shape (see dash-dot line "F" in FIGS. 1 and 7). It is designed so that on both sides of an annular zone 4 in the plane x-x of the largest handle base body diameter D lying transverse to the blade 1 4 individual grooves 5 and 6 extend. The latter run in the longitudinal direction of the basic booklet body K. They are concave in this direction in such a way that the individual fillets 5, 6 from the ring zone 4 of the largest diameter of the booklet body D to the smaller diameter of the basic booklet body d 1 and d 2 drop. With regard to these sections, one can therefore speak practically of frustoconically tapering zones extending on both sides of the largest diameter in the manner of truncated cones. The latter are facing each other with their larger base areas.

In each case adjacent individual fillets 5 and 6 running alongside one another in the longitudinal direction collide to form a correspondingly concave apex edge 7. The latter is convexly rounded.

The individual fillets 5 and 6 are arranged in an angularly symmetrical arrangement about the longitudinal central axis y-y of the base body K of the booklet. Seen in the circumferential direction, the individual fillets 5, 6 form a rectilinear base 8 (see FIGS. 3 and 10), which could also be slightly concave. The angular distance between the individual fillets is 60 ° to each other.

The marginal edges 9 of the individual fillets 5 and 6 are rounded both in the transverse direction and in the longitudinal direction of the base body K. The curves are only made so far that only the edges generated by the fillet are broken, but otherwise there is a multifaceted basic shape with high grip.

The quite multifaceted gripping surface of the basic magazine body K has hard and soft-elastic grip zones. So are the tapered zones according to FIG. 2, ie the two truncated cones as soft grip zones W are realized, ie they are predominantly made of resilient, compressible material on the outside, such as, for example, soft plastic, rubber or the like. The intermediate zone 4, which has the larger diameter D and is of circular design, consists of hard, non-compressible material, in particular hard plastic, and with its exposed outer surface forms the hard grip zones H. The individual grooves 5 and 6 lying on the tapering zones also go into the hard plastic intermediate zone 4. These account for about a third to a quarter of the surface.

The ring-individual fillet 2 adjoining the zone tapering on the blade side is likewise made of the elastically flexible material according to FIG. 2. It is a relatively weakly hollowed section of the ring throat. The latter has a hard plastic core 10, which contains the end of the screwdriver blade 1 molded on the base body side and equipped with flattened wings 11. Such wings can be produced by flattening the shaft 1 of the blade 1, which is hexagonal in cross section. The elastically resilient zone consequently occurs in the shaft-covering overlap region as a jacket M 1 (FIG. 2).

As can be seen in FIG. 2, the hard plastic core 10 continues practically over the entire length of the base body K of the booklet. This section is designated 10 '. As a result, both tapered sections are formed in the form of elastic sheaths M2, M3 around the hard plastic core 10/10 '. The thickness of the shells M1, M2, M3 is essentially constant. This results in equivalent elasticity for the soft areas. The fingers of the holding hand do not "drown" in the elastic material. The core rather leads to a stabilizing basis.

The face of the section that tapers away from the blade in this direction is equipped with a dome-shaped tip 12 made of hard plastic. This can be a separately formed, subsequently attached individual component (as shown in FIG. 2) or, of course, an immediately molded tip. The multiple parts are recommended if such a crest 12 is to consist of even harder material, for example if such tool handles for chisels (chisels) are to be used. In the multi-part version, a central pin 13 of the dome enters a corresponding recess 14 in the end section of the hard plastic core 10.

The spherical top surface runs smoothly into the tapered zone made of elastic material.

As can also be seen in FIG. 2, the surface of the hard plastic core 10/10 'roughly matched to the surface shape of the base body of the booklet is strongly grooved or stepped. This leads to an intimate bond between the jacket-forming elastic material. Such a structure of the core proves to be particularly advantageous when the shells M1 to M3 are molded onto the core. In order to bring about an even more intimate bond between the elastic jacket interrupted by the hard plastic intermediate zone 4, the shells M2 and M3 are connected to one another due to tunnel-like openings 15 in the intermediate zone. A total of four such openings 15 arranged at the same angle are provided. The material bridges connecting the two sheaths M2 and M3 concealed with one another have the reference number 16. With regard to the openings 15, there are longitudinal bores which are parallel to the longitudinal center axis y-y and have the same spacing.

The end faces 4 'of the annular intermediate zone 4 have annular grooves 17. As a result, the adjacent soft material can step practically roof-shaped under the edge of the hard plastic ring zone 4. There is a larger joint area and thus a good adhesive bond.

The individual fillets 5 rise slightly, especially in the area of the stitching body on the blade. When inserting the end member of the index finger into the ring fillet 2, the thumb as a counterpart, ie its end member in the single fillet 5, finds a favorable support position and thus favors a quick and easy turning (so-called twisting) of the screwdriver, which occurs when a screw is screwed in before Tightening is one of the main functions of the screwdriver. The fold of the joint between the middle link and the end link comes to lie exactly in the ridge of the intermediate ring zone 4 of the largest diameter D of the basic body K of the booklet. When stored in this way, the thumb experiences its largest contact surface. The ball of the thumb and the wrist can therefore tightly enclose the base body K. The latter encompassing other fingers find equally favorable storage positions in the individual fillets 5 and 6, with the different lengths of the individual finger limbs and the position of the fingers being fully taken into account by designing the basic magazine body in a modification of a basic barrel shape. The single fillets 5, 6 and their special geometric arrangement provide optimal insert surfaces for the fingers and prevent the risk of the hand slipping off the staple body K. The overall strongly faceted surface still allows a certain adjustment to different indentation parts, since the elastic resilient grip zones W allow the appropriate adjustment. Nevertheless, high torque can be achieved via the harder ring zone, which has the largest diameter. 4 to 6, the resilient material surfaces W and the hard plastic areas H are each provided in a different division. The soft material extends into a polygonal end section E as a roll-away protection, which is so large that it is lying booklet comes into contact with the pad due to the weight of the blade.

The screwdriver booklet according to the second embodiment (FIGS. 7 to 11) is basically of the same structure; the reference numbers are used analogously, sometimes without textual repetitions.

The two grip zones W of softer material lying adjacent to the grip zone H of harder material are here divided on the one hand into the intermediate zone 4 of the largest diameter D, that is to say interrupted. As a result, soft zone fields lie within a practically lattice-like surface structure of the hard handle base body K. The interruption lies in the circumferential direction, as a result of which soft and hard grip zones W and H alternate with one another in this direction. Such a subdivision is also conceivable in the axial direction.

The grip zones W of other materials form single fillets which merge into the intermediate zone.

The grip zones W of softer material are designed as pads P which are inserted into depressions 18 of the base body K made of a harder material. Corresponding to the hexagonal cross section of this base body in the area of assignment, there are six recesses 18 distributed at equal angles on the circumference of the portions of the booklet which taper in the shape of a truncated cone. The depressions 18 have undercut side walls 19 on all sides. The undercut angle is 20 ° to the base of the recess. The side walls 19 are gripped behind by the correspondingly trapezoidal foot of the cushion P, so that there is a good support for the cushion P with correspondingly positive engagement.

In addition to this purely form-fitting holder using the elasticity of the material, it can also be inserted under a certain amount of pretension; in addition, an adhesive connection can be realized at the same time. On the other hand, a heat seal connection can be used at the same time when such pads P are injected or injected into the depressions. For this purpose, a plastic component corresponding to the tack material would be added to the cushion P, which is made of rubber, for example.

The cushions P protrude above the fillet 8 of the individual fillets 5, 6. Their upper side, when seen in the transverse direction, is convex. The bulge can extend over the entire transverse width of a single fillet. On the other hand, however, an upper-side curvature that is only near the edge is also conceivable, so that, as in the exemplary embodiment, the surface area of the upper side that remains between the transverse transverse curvatures runs parallel to the base of the recesses 18.

The transversely rounded edge region of the pads P overlaps the recess edge 20 like a lip.

In the axial direction, the cushions P take on a concave fillet shape to match the shape of the individual fillets 5, 6 (see FIG. 8). The section of the cushions projecting beyond the individual fillets 5 corresponds to approximately one third to one fifth of the total thickness of the cushions.

As can be seen, the cushions P are of identical design to one another (the slight deviations are due to the drawing). As a result of the individual fillets 5, 6 widening toward the diameter-widened intermediate zone 4, the cushions P have a corresponding, almost congruent plan. As a result, the ends of the pads P pointing in this central direction are somewhat wider. The assembly of the booklet is consequently carried out in such a way that the mutually identical pads P on the two truncated cones are used upside down.

On the other hand, a completely symmetrical cushion body is also conceivable.

All the new features mentioned in the description and shown in the drawing are essential to the invention, even if they are not expressly claimed in the claims.

Claims (16)

1. Handle for manual tools, in particular for screwdrivers, consisting of two materials (H/W) of different hardness, of which the harder material (H) bearing the tool is non deformable under the forces occurring due to the working stress, but the other softer material (W) allows slight elastic deformations under the stress forces of the hand, the outer surface of the handle having grip zones of harder and softer material lying alternately next to each other in longitudinal direction of the handle, characterized in that only two grip zones (W) of softer material lie adjacent in axial direction to one grip zone (H) of harder material arranged between them, and in that the grip zone (4) of harder material (H) encircling the handle is that with the largest diameter and the grip zone (W) of softer material adjacent to the latter is designed in the form of conoidal frustrums tapering to the ends of the handle.

2. Handle according to one or more of the preceding claims, characterized in that the grip zones (W) of softer material are interrupted in circumferential direction by intermediate sections (grip zones H) of harder material.

3. Handle according to one or more of the preceding claims, characterized in that the grip zones of softer material form individual flutes which extend into the intermediate zone (4).

4. Handle according to one or more of the preceding claims, characterized in that the end facing away from the blades is fitted with a cap shaped dome (12) of hard plastic.

5. Handle according to one or more of the preceding claims, characterized in that an annular flute (2), likewise consisting of elastic resilient matrial, adjoins the section tapering to the blade side.

6. Handle according to one or more of the preceding claims, characterized in that both the tapering grip zones are formed in the form of elastic jackets (M2, M3) around a hard plastic core (10').

7. Handle according to one or more of the preceding claims, characterized in that the jackets (M1, M2, M3) are moulded on and the latter two (M2, M3) are connected to each other via tunnel shaped passages (15) in the circular zone (4).

8. Handle according to one or more of the preceding claims, characterized by annular grooves (17) in the end faces (4') of the hard plastic intermediate zone (4).

9. Handle according to one or more of the preceding claims, characterized in that, with the circular shape of the intermediate zone (4), the end section on the blade side is polygonal and designed on the outside in soft material.

10. Handle according to one or more of the preceding claims, characterized in that the grip zones (W) of softer material are designed as paddings (P) set into hollows (18) of the basic body (K) consisting of harder material.

11. Handle according to one or more of the preceding claims, characterized in that the hollows (18) have undercut side walls (19) to retain the paddings inserted in a form fitting manner.

12. Handle according to one or more of the preceding claims, characterized in that the upper region of the paddings (P) overlaps the edge of the hollow (20).

13. Handle according to one or more of the preceding claims, characterized in that the padding (P) has a convexly curved upper side.

14. Handle according to one or more of the preceding claims, characterized in that the paddings (P) are inserted in the region of the individual flutes (5, 6) and form a convex upper side designed in transverse direction to the concave extent of the flutes.

15. Handle according to one or more of the preceding claims, characterized in that the paddings (P) are of mutually similar design.

16. Handle according to one or more of the preceding claims, characterized in that the paddings (P) of mutually similar design in the two conoidal frustums are inserted inversely to one another.

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