EP1230071A1

EP1230071A1 - Chisel

Info

Publication number: EP1230071A1
Application number: EP00987129A
Authority: EP
Inventors: Wolfgang Peetz
Original assignee: Hawera Probst GmbH
Current assignee: Robert Bosch Power Tools GmbH
Priority date: 1999-11-17
Filing date: 2000-11-16
Publication date: 2002-08-14
Also published as: WO2001036163A1; DE10057124A1

Abstract

The invention relates to a chisel (1) comprising a chisel head (4), a chisel shank (3) and a clamping shank (2), especially to a flat chisel or pointed chisel that is preferably used in a hammer drill. The inventive chisel shank (3) and/or the chisel head (4) comprise(s) axially extending recesses (7) and/or ribs (6) or webs (6).

Description

"Chisel"

The invention relates to a chisel according to the preamble of patent claim 1.

Chisels of this type have a chisel shank with a round or hexagonal cross section, the diameter of the chisel shank being dependent, inter alia, on the demolition performance which the respective chisel is to provide. Chisels are regularly equipped with larger diameter chisel shafts to increase performance. However, since the chipping performance of a chisel essentially depends on the acceleration or the speed at which the chisel hits the earthenware, increasing the performance of a chisel by increasing the diameter of the chisel shank is generally counterproductive.

With regard to the chisel head, it is disadvantageous that a solidly designed chisel head always has a high penetration resistance, which reduces its performance. Furthermore, due to its large mass, a massive chisel head has a negative effect on the chipping performance of the chisel, since this depends essentially on the acceleration or the speed at which the chisel is applied the chisel hits.

The invention has for its object to develop a chisel that optimally forwards the shock waves generated by the hand-operated electropneumatic hammer drill to the chisel head. Furthermore, it is an object of the invention to reduce the penetration resistance of the chisel head, to increase its stability and strength, to improve the demolition performance and to optimize the transmission of the shock waves through the chisel head onto the chisel cutting edge or chisel tip.

This object is achieved on the basis of a chisel according to the preamble of patent claim 1 according to the invention by the characterizing features of patent claim 1.

The chisel according to the invention with a chisel head, a chisel shank and a clamping shank, in particular flat or pointed chisels, preferably for use in a hand-operated electropneumatic hammer drill, e.g. B. with an SDS-Plus or SDS-Max insertion end, is characterized in that the chisel shaft and / or the chisel head has recesses and / or ribs or webs. With regard to the shank, this measure reduces the weight of the chisel compared to conventional chisels and achieves increased torsional rigidity and higher bending rigidity. The recesses provided on the circumference of the chisel shank, with the formation of rib-like reinforcements, are designed on the basis of examples from nature in order to achieve a lightweight construction. Furthermore, the surface tension is reduced because bending and torsional stresses in the recesses of the chisel shank are lower than on its peripheral surface. The recesses arranged on the side surface of the chisel head also greatly reduce the weight of the chisel and optimally distribute the shock wave impulse over the chisel edge or concentrated on the chisel tip. A narrow, rib-reinforced design of the chisel head further improves the penetration behavior of the chisel into the chisel material. The grooves also make it easier to remove material because they guide the removal in the direction of the longitudinal axis of the chisel. For the chisel shank and the chisel head, this "lightweight construction" enables inexpensive manufacture of high-quality chisels, in which the service life and efficiency are increased by simple measures. Compared to conventional chisels, there is a material saving, which is particularly economical because chisels are made from expensive, high-quality steels. It is also advantageous that less volume has to be deformed when the chisel is forged and the forging machine is thus protected. The recesses with reinforcing ribs lead to a considerable weight saving, which has a positive effect on the handling of a motor-driven hammer or a motor-operated hammer drill due to the smaller moving masses.

Alternatively to the production by e.g. B. Forging is also possible to manufacture the chisel from a drawn profile bar, e.g. B. as an endless extruded profile, the insertion end being either formed subsequently technically or by machining or attached by joining technology.

The core of the invention is therefore a reduction in mass compared to conventional chisel tools, which is achieved by a type of "lightweight construction" with recesses and reinforcing ribs or webs. This applies both to the chisel shank and independently of it to the chisel head.

Due to the low mass, the acceleration of the Tool and thus an increase in demolition performance. Despite the lower weight, there is a considerable increase in the strength of the tool and a significantly higher removal rate.

An advantageous embodiment of the subject matter of the invention provides that the recesses run parallel to a longitudinal axis of the chisel and / or in a cutting surface of the chisel head.

Another advantageous training of

Subject of the invention provides for the recesses to be designed with a part-circular, U-shaped, V-shaped or trough-shaped cross section. Such recesses can be made easily and with high accuracy.

According to a particular embodiment of the

The object of the invention is to arrange the recesses symmetrically or asymmetrically in the bit head and / or in the bit shank relative to one another. A symmetrical arrangement of the recesses makes it possible to keep the resilience of the chisel on the circumference at one level. An asymmetrical or at least partially asymmetrical distribution of the notches can be used to specifically eliminate unwanted vibrations, since the chisel shaft reacts differently, for example, to bending effects on the circumference from different directions. Such loads occur, for example, when chiseling in a narrow gap.

It is advantageous if the recesses merge into a chisel surface with rounded longitudinal edges. This avoids the creation of sharp edges that are particularly sensitive to stresses caused by torsional stresses and / or bending stresses. At such soft transitions from the recesses into the chisel surface, stress peaks that lead to cracks and breakage are avoided or total failure of the chisel.

It is further proposed according to the invention that the recesses are designed to be open or closed at the ends, with closed ends merging into the outer surface of the chisel in an arc. Particularly in the case of chisels with a large diameter of the chisel shank compared to the clamping shank, a transition of the clamping shank into a chisel shank with grooves open at the end of the clamping shank is particularly advantageous. This avoids the particularly break-prone transition from a small cross-sectional area to a large cross-sectional area. A closed design of the end-side recesses makes it possible to keep the transition between the clamping end and the chisel shank free from being influenced by the recesses. This can be particularly advantageous for chisels with a small shank diameter. Furthermore, "open cross sections" can be produced on the chisel shank using the extrusion process.

According to the invention, it is further proposed that the chisel head has at least one pocket-shaped recess in plan view, in particular approximately triangular or V-shaped or elliptical or U-shaped or circular, on at least one cutting surface. Such a recess favors chip evacuation, since the chisels are not removed accidentally, but are given a direction. Furthermore, the cross-sectional volume of the chisel head is reduced by these recesses and thus the penetration of the chisel into the chisel material is facilitated. The webs delimiting the recesses in the chisel head also improve the demolition behavior. In particular, they cause the occurrence of additional punctual stress peaks in the chiselled material and thus the breaking off of desired larger pieces of chiseled material, which increases the removal rate. The recesses with stiffening ribs also give the chisel head greater stability through shaping.

It is particularly advantageous if the axes of symmetry of the recesses on the chisel head are arranged parallel or at an angle (α) to the longitudinal axis of the chisel. This alignment directs and concentrates the shock waves on the chisel tip or chisel cutting edge.

An expedient embodiment of the subject matter of the invention provides that the longitudinal grooves extend over the entire or almost the entire chisel shank. As a result, the chisel shank has uniform mechanical properties and, in particular in the case of torsional loads, can yield over the entire length of the shank in extreme cases, without stressing sensitive cross-sectional transitions.

Finally, a further embodiment of the object of the invention provides for the longitudinal grooves to be axially spaced as longitudinal groove sections or to be offset on the circumference of the chisel shank. With such an arrangement, in particular longer chisel shafts can be adapted to the mechanical requirements in all areas of the chisel shank. For example, it may be useful to provide the transition areas from the chisel shank to the clamping end and the chisel head with a larger number of grooves to adapt the cross-sectional areas than the central area of the chisel shank.

An advantageous embodiment of the subject matter of the invention is also present if the chisel head has additional elevations on its side face to form a type of "chip breaker". These elevations serve as struts, which give the bit head additional stability Lend sections without greatly increasing the cross-sectional area of the chisel head.

Further details of the invention are described in the drawing using schematically illustrated exemplary embodiments.

Here shows:

Figure 1 is a side view of a chisel with six longitudinal grooves;

Figure 2 shows a section along the section line

II-II by the chisel shown in Figure 1;

Figure 3 is a side view of a chisel with three longitudinal grooves;

Figure 4 shows a section along the section line

IV-IV through the chisel shown in Figure 3;

Figure 5 is a side view of a chisel with four longitudinal grooves;

6 shows a section along the section line

VI-VI through the chisel shown in Figure 1;

Figure 5a is a side view of a chisel with a cross section of a wing profile;

Figure 5b is a right side view of the chisel shown in Figure 5a; Figure 5c is a side view of another

Chisel with a cross section of a wing profile;

Figure 5d is a right side view of the chisel shown in Figure 5c;

Figure 6a is a view of the chisel shown in Figure 5a from the direction Via - Via;

Figure 6b shows a cross section along the

Section line VIb - VIb through the chisel shown in Figure 5b;

FIG. 6c shows a view of the chisel shown in FIG. 5c from the viewing direction VIc-VIc;

FIG. 6d shows a section along the section line VId-VId through the chisel shown in FIG. 5d;

FIG. 7 shows a sectional view of a chisel shank of a chisel with four grooves open at the ends;

Figure 8 is a sectional view of a chisel shank of a chisel with three grooves open at the ends;

FIG. 9 shows a sectional view of a chisel shank of a chisel with six grooves open at the ends;

Figure 10 is an enlarged sectional view along the section line XX of the chisel shown in Figure 5;

Figure 11 is an enlarged sectional view taken along section line XI-XI of the bit shown in Figure 3;

FIG. 12 shows a sectional view of a chisel shank of a chisel with six grooves closed at the ends;

FIG. 13 shows a side view of a chisel head with recesses which are elliptical in cross section;

FIG. 14 shows a side view of a chisel head with recesses which are V-shaped in cross section;

FIG. 15 shows a side view of a chisel head with recesses which are U-shaped and triangular in cross section;

FIG. 16 shows a side view of a chisel head with a recess which is triangular in cross section;

FIG. 17 shows a side view of a chisel head with recesses which are U-shaped in cross section;

Figure 18 is a side view of a chisel head;

Figure 19 is a side view of a chisel head;

Figure 20 is a side view of a chisel head;

Figure 21 is a side view of a chisel head; Figure 22 is a side view of a chisel head;

Figure 23 is another side view of a chisel head;

Figure 24 is a side view of a wide chisel head;

Figure 25 is a sectional view taken along the

Section line XXV-XXV of the chisel head shown in Figure 24;

FIG. 26 shows a variant of a sectional view along the section line XXV-XXV of the chisel head shown in FIG. 24;

Figure 27 shows another variant of a

Sectional view along section line XXV-XXV of the chisel head shown in FIG.

Description of the embodiments:

A chisel 1 is shown in side view in FIG. This consists essentially of a clamping shank 2, a chisel shank 3 and a chisel head 4. As an SDS-Plus, the clamping shank 2 has engaging grooves 5 into which the chuck of an electrically or electropneumatically operated hammer drill, not shown, engages, with which the chisel 1 is driven The chisel shank 3 has webs or ribs 6 on a surface 6a, into which recesses 7 are made. The recesses 7 are preferably made by forging a Chisel blanks trained. The recesses 7 have longitudinal edges 8 which run parallel to a longitudinal axis 9 of the chisel. At transitions 10, 11, the chisel shank 3 merges into the chisel head 4 or into the clamping shank 2. The recesses 7, which are designed as grooves 12 or longitudinal grooves 12a, have closed ends 13, 1 toward the transitions 10, 11.

FIG. 2 shows a section through the chisel shank 3 of the chisel 1 shown in FIG. 1 (in FIGS. 2, 4, 6, 7, 8, 9 the hatching of the cut surfaces is dispensed with in order to keep the figures clearer) Sectional view clearly shows that the chisel 1 shown in Figure 1 has six recesses 7, which are separated by six webs or ribs 6. The recesses 7 or the webs or ribs 6 are arranged point-symmetrically to the longitudinal axis 9 of the chisel on the surface 6a of the chisel 1.

FIG. 3 shows a further chisel 1 which has three recesses 7 which are arranged on the surface 6a of the chisel shank 3 and which are separated by webs or ribs 6. The recesses 7 have closed ends 13 towards the chisel head 4. The recesses 7 merge towards the clamping shaft 2 with open ends 15 into the clamping shaft 2. Thus, the transition 11 is designed here so that the cross-sectional area changes only slightly from the clamping shank 2, which has a diameter d, to the chisel shank 3, which has a diameter D. This is the case because the cross-sectional area of the chisel shank 3 is calculated from a circular area 16 defined by the diameter D (shown with a broken line in FIG. 4) minus the cross-sectional areas 17 of the recesses 7.

FIG. 4 shows a section through the chisel shank 3 of the chisel 1 shown in FIG. 3. In this sectional view it becomes clear that the chisel 1 shown in FIG. 3 has three recesses 7, which are arranged point-symmetrically to the longitudinal axis 9 of the chisel on the surface 6a of the chisel 1. In cross section it can be seen that the recesses 7 are designed as trough-shaped recesses 18. Webs or ribs 6 are arranged between the trough-shaped recesses 18. These webs or ribs 6 serve as reinforcing ribs 19. The reinforcing ribs 19 give the chisel shaft 3 a rib profile 19b which brings about increased rigidity, strengthening and strengthening of the chisel shaft 3.

FIG. 5 shows a further chisel 1 which has four recesses 7 which are arranged on the surface 6a of the chisel shaft 3 and are separated by webs or ribs 6. The recesses 7 run towards the chisel head 4 into closed ends 13 or into open ends 13 '. The recesses 7 with open ends 15 merge into the clamping shaft 2.

FIG. 6 shows a section through the chisel shank 3 of the chisel 1 shown in FIG. 5. It is clear in this sectional view that the chisel 1 shown in FIG. 5 has four recesses 7, which are arranged point-symmetrically to the longitudinal axis 9 of the chisel on the surface 6a of the chisel 1 , In cross section it can be seen that the recesses 7 are designed as part-circular recesses 20. Webs or ribs 6 are arranged between the part-circular recesses 20.

Figure 5a shows another chisel 1 in side view. The chisel 1 has a clamping shank 2, a chisel shank 3 and a chisel head 4. The chisel head 4 ends in a cutting edge 53. 3 webs or ribs 6 run parallel to a chisel longitudinal axis 9 on the chisel shaft. These are arranged symmetrically to the chisel longitudinal axis 9. FIG. 5b shows a side view of the chisel 1 shown in FIG. 5a. In this view, further engagement grooves 5 on the clamping shank 2 can be seen. The chisel 1 is designed as a flat chisel 52, the chisel shaft 3 of which merges smoothly into the chisel head 4.

FIG. 6a shows a top view of the cutting edge 53 of the chisel 1 shown in FIGS. 5a and 5b. The chisel shaft 3 is designed as a profile bar 87 and has a wing profile 88 or a rib profile 88. This profile 88 has two wings or ribs 6, 90, 91 which extend in the direction of the cutting edge 53. The wings 90, 91 merge into one another in a fuselage area 92, the fuselage area 92 being of reinforced design. Compared to the fuselage area 92, the wings 90, 91 are designed to be slimmer and thus make it easier for the chisel to penetrate into the material to be processed. The torsion stiffness and the bending stiffness of the chisel 1 are decisively increased by the reinforced design of the fuselage area 92.

FIG. 6b shows a section along the section line VIb-VIb through the view of the chisel 1 shown in FIG. 5b. In the fuselage area 92, a dashed circle 93 indicates a rod-shaped core 94 which runs through the chisel shaft 3 and preferably represents a continuation of the clamping shaft 2 , The wings 90, 91 are designed such that their upper sides 90a, 91a and their lower sides 90b, 91b extend in the region of the core 94 as tangents 95 to the circle 93. As a result, the core 94 is enclosed by the wings 90, 91 and fully integrated. Small ribs 6 are formed at joints 96, 97 of the tangents 95.

FIGS. 5c and 5d show two side views of a further chisel 1, which is designed as a flat chisel 52. The chisel essentially consists of a clamping shank 2, a chisel shank 3 and a chisel head 4. The chisel head 4 ends in a cutting edge 53. Ribs or webs 6 are arranged on the chisel shank 3 parallel to the longitudinal axis 9 of the chisel.

FIG. 6c shows a plan view of the cutting edge 53 of the chisel 1 shown in FIG. 5c. The chisel shaft 3 is designed as a profile bar 87 which has a wing profile or a rib profile 88. The profile 88 essentially consists of two ribs or wings 6, 90, 91 which merge into one another in a fuselage area 92 of the chisel 1.

FIG. 6d shows a section along the section line VId-VId through the chisel 1 shown in FIG. 5d. A dashed circle 93 indicates a core 94 which passes through the chisel shaft 3 and is preferably to be regarded as a continuation of the clamping shaft 2. The wings 90, 91 have steps 98 on upper sides 90a, 91a and lower sides 90b, 91b. The steps 98 cause a broadening of the wing 6, 90, 91 to a Meißellängssymetrieebene 89 back and at the same time the formation of a further rippenfδrmigen gain 6. In the region of a Meißelquersymetrieebene 89 ^■ joints 96 form, 97 of the top sides 90a, 91a and lower sides 90b, 91b the wing 90, 91 hump 99. These rib-shaped humps 6, 99 have the function of small transverse wings 100 and serve in particular the increased torsional and bending stiffness of the profile, the profile design in the area of the chisel shank avoiding unnecessary mass and thus better energy transmission is achieved.

FIG. 7 shows an enlarged view of the section shown in FIG. 6 through the chisel shank 3 of the chisel 1 shown in FIG. 5. In FIG. 7 it can be seen that the part-circular recesses 20 are rounded Longitudinal edges 8 merge into the webs or ribs 6 of the chisel shaft 3. A dashed circle 21 indicates that the part-circular recess 20 is approximately quarter to semicircular in cross section. The circle 22 indicated by dashed lines shows that the rounded longitudinal edge 8 has an approximately quarter-circular shape in cross section.

FIG. 8 shows an enlarged view of the section shown in FIG. 4 through the chisel shaft 3 of the chisel 1 shown in FIG.

FIG. 9 shows an enlarged view of the section shown in FIG. 2 through the chisel shaft 3 of the chisel 1 shown in FIG. 1, the sectional view in FIG. 9 showing a chisel 1 with recesses 7 that are open at the ends. The recesses 7 are embodied here as U-shaped recesses 25 and give the chisel shank 3 a profile 26 with a spline-shaped cross section. Alternatively, the recesses 25 are provided with a V-shaped cross section 25a (indicated by dashed lines as an example).

Analogously to FIGS. 7 to 9, which show sectional representations of chisel shafts 3 with recesses 7 that are open at the end, FIGS. 10 to 12 show the corresponding chisel shafts 3 with recesses 7 that are closed at the end.

The section shown in FIG. 10 along the section line XX of the chisel 1 shown in FIG. 5 shows the recesses 7 which end in closed ends 13. It can be seen from FIGS. 1 to 12 that the chisel shafts shown have profiles which, compared to a conventional round profile and have a lower weight, have a higher torsional and bending stiffness. The weight saving achieved by the recesses allows the bit to be accelerated more quickly by the hammer drill, so that the demolition performance is greater. In addition, this improvement in the mechanical properties improves the transmission of the movement impulses generated by the hammer drill to the bit head, since less energy is lost in the bit shaft due to twisting and bending of the bit shaft. Furthermore, the chisel shaft is less sensitive to overloading due to torsion and bending than a conventional round profile, since torsional and bending stresses in the recesses weaken due to the shorter distance to the longitudinal axis of the chisel.

According to an embodiment variant, not shown, the chisel shank consists of a polygonal profile, in particular a square or pentagonal or hexagonal or octagonal profile, in which the individual side surfaces have recesses. In this way, the torsion and bending stiffness of the chisel shank is doubled due to its basic shape and the grooves made. Alternatively, the use of a profile with an oval cross section is provided with recesses which lead to the formation of ribs. This can preferably be used with wider spade chisels (spade width up to approximately 80 mm) for hand-held electrical or electropneumatic hammer drills or hammer drills.

Another embodiment variant, not shown, provides for the longitudinal groove sections to be axially spaced on the chisel shaft. For example, three shorter grooves can be arranged one behind the other. Furthermore, the longitudinal groove sections can be offset on the circumference of the chisel shaft be arranged. In this way it is possible to form sections with different mechanical properties.

According to a further embodiment variant, the chisel is produced as an extruded profile, into which the recesses have already been formed or can be introduced subsequently by forging and / or machining. The clamping shank is either also formed by forging and / or machining or welded to the chisel shank as a finished part.

FIG. 13 shows a chisel head 50 of a chisel 40 which merges into a chisel shank 51 which is only shown in part. The chisel head 50 is designed as a flat chisel 52. This has a cutting edge 53 and a front side surface 54 and a rear side surface 55. The cutting edge 53 merges into the side surfaces 54, 55 via a chisel cut 72, which is formed by a front cutting surface 72a and a rear cutting surface 72b. The bit head 50 is connected to the bit shaft 51 via a neck 56. Recesses 57 are arranged on the side surfaces 54, 55 (the side surface 55 cannot be seen in the illustration in FIG. 13). The recesses 57 shown in FIG. 13 have an elliptical cross section 58. The main axes 59 align the elliptical cross sections 58 approximately parallel to a longitudinal axis 60 of the chisel shaft 51. Between the recesses 57 there remain webs or ribs 41 which give the chisel head 50 high stability despite the reduction in material. On the rear side surface 55, the chisel head 50 is designed corresponding to the front side surface 54, the chisel head is formed symmetrically to a plane 42, in which the longitudinal chisel 60 and cutting edge 53 lie. FIG. 14 shows a further chisel head 50, on the side surfaces 54, 55 of which U-shaped recesses 61 are arranged, which have longitudinal axes 62. These are aligned at an angle α to the central longitudinal axis 60 of the chisel shank. The angle α is in a range from approximately 10 ° to 30 ° degrees. As a result of this angled alignment of the U-shaped recesses 61, the shock waves 63 (symbolically shown as small arrows) generated by a rotary hammer (not shown) are also guided on webs or ribs 41, particularly in edge regions 64 of the cutting edge 53. The chisel head 50 is formed symmetrically to a plane 42 in which the longitudinal chisel 60 and cutting edge 53 lie.

FIG. 15 shows a further embodiment of a chisel head 50. Geometrically different recesses 57 are arranged on the side surfaces 54, 55 of the chisel head 50. The recesses 57 arranged on the side surface 54 are a U-shaped recess 61 and two triangular recesses 65. All the recesses 57 are arranged symmetrically to the longitudinal axis 60 of the chisel. The triangular recesses 65 are arranged with base sides 66 at an angle β of approximately 30 ° to the longitudinal axis 60 of the chisel. Shock waves 63 are again indicated by small arrows. The U-shaped recess 61 serves as a wedge 67, which forces the shock waves 63 from their natural straight course along the longitudinal axis 60 of the chisel to radiate. This radial distribution, which is roughly aligned with the cutting edge 53, is supported by the triangular recesses 65. These have the effect that the edge regions 64 are also supplied with shock waves 63 in a targeted manner via detours 67. The recesses 57 are separated by differently shaped webs or ribs 41. The chisel head 50 shown in FIG. 15 is also formed symmetrically to a plane 42 in which the chisel longitudinal axis 60 and the cutting edge 53 lie.

FIG. 16 shows a further chisel head 50. The chisel head 50 is designed as a pointed chisel 68 and has a conical surface 69 and a cutting tip 70. A V-shaped recess 71 is arranged on the side surface 69.

FIG. 17 shows a further chisel head 50 of a further flat chisel 52, on the side surfaces 54, 55 of which recesses 57 designed as U-shaped recesses 61 are arranged. This forms ribs or webs 41 on the side surfaces 54, 55, which reinforce the bit head 50. Furthermore, the recesses 57, like all other recesses 57 on the chisel heads 50, act as chip breakers. A large chip (not shown) wedges in the recess 57 and is pushed and broken by the recess 57 and / or the ribs or webs 41 against the unbroken material in a subsequent blow generated by the hammer drill. The chisel head 50 shown in FIG. 17 is also formed symmetrically to a plane 42 in which a chisel longitudinal axis 60 and a cutting edge 53 lie.

FIGS. 18 to 26 show further variants of chisel heads 50.

FIG. 18 shows a chisel head 50 designed as a flat chisel 52. This chisel head 50 has a front side surface 54 and a rear side surface 55. The side surfaces 54, 55 point to a cutting edge 53. The cutting edge 53 merges into the cutting surfaces 54, 55 via a chisel cut 72. The chisel head 50 has a height H, the chisel cut 72 has a height h. The height h of the chisel cut 72 is approximately 1/15 of the height H of the chisel head 50. On the side surfaces 54, 55 are Recesses 57 are arranged, which are designed as U-shaped recesses 61. These run out towards the cutting edge 53 into the cutting surface 72a.

FIG. 19 shows a chisel head 50 designed as a pointed chisel 68. The chisel head 50 has a web or rib 41 designed as a protuberance 73 on a cone-shaped side surface 69. The protuberance 73 has a surface 75 that is curved parallel to the cutting surface 69. Alternatively, the surface 75 is flat and aligned with a bisector 76 parallel to a surface line 77 lying on the cutting surface 69.

FIG. 20 shows another chisel head 50 designed as a flat chisel 52. In addition to a cutting edge 53, the chisel head 50 has a chisel cut 72 and a side surface 54. On the side surface 54, ribs or webs 41 designed as elevations 73 are arranged, which are formed by elliptical projections 78. These have a curved surface 75. According to one embodiment variant, it is provided that the surface 75 is made flat or curved toward the cutting surface 54. In both versions 55 elliptical projections 78 are also provided on a rear side surface.

FIG. 21 shows a further chisel head 50 designed as a pointed chisel 68. The chisel head 50 has a recess 57 which is aligned with a cutting tip 70 and is designed as a drop-shaped recess 79. According to one embodiment variant, the pointed chisel 68 has a further drop-shaped recess 79 on its rear side, not shown.

FIG. 22 shows a chisel head 50 of a flat chisel 52, which has two recesses 57 on a front side surface 54 and a U-shaped elevation designed as a rib or web 41 74 owns. The U-shaped elevation 74 serves to reinforce the chisel head 50 towards a central region 80 of the cutting edge 53. The recesses 57 designed as triangular recesses 65 serve to save material. Edge areas 82, 83 of the chisel head 50 are reinforced by ribs or webs 41. Corresponding deformations are provided on the rear side surface 55, which cannot be seen.

FIG. 23 shows a chisel head 50 of a flat chisel 52 which has two recesses 57 which are designed as a U-shaped recess 74. At edge regions 82, 83, webs or ribs 41 are created by this U-shaped recess 74, which reinforce the bit head 50 up to a bit cut 72. In a central area 84 there is also a web or rib 41 which reinforces the chisel head. Corresponding deformations are provided on the rear side surface 55, which cannot be seen.

FIG. 24 shows a chisel head 50 of a flat chisel 52 which has three recesses 57 which are designed as U-shaped recesses 61. These are set back with respect to a side surface 54 and run out at edges 86 without a step into a cutting surface 72a of a chisel cut 72. Between the U-shaped recesses 61 there are four webs 41 by which the chisel head 50 is reinforced. According to an embodiment variant, which is also shown in FIG. 24, curved or U-shaped ribs 85 are formed on the cutting surface 54. These also serve to reinforce the bit head 50.

FIG. 25 shows a section along the section line XXV-XXV through the chisel head 50 shown in FIG. 24. This section drawing shows that the U-shaped recesses 61 are formed on the front cutting surface 54 and on the rear cutting surface 55. The webs or ribs 41 are closed between the U-shaped recesses 61 see. A chisel head cross section 86 is identified by the hatching. Its surface 94 is smaller compared to a dashed-edged surface 95 of a conventional chisel. The area 95 surrounded by dashed lines is calculated by multiplying a bit head thickness D1 by a bit head width Bl. The comparison applies to each cross-sectional area comparison carried out in an area A (see FIG. 24).

FIG. 26 shows a section along the section line XXV-XXV through the chisel head 50 shown in FIG. 24. This sectional drawing corresponds to the embodiment variant described in FIG. The ribs 85, which are curved or U-shaped on the side surface 54, can be seen here in section. As can be seen from FIG. 26, the ribs 85 run below the side surface of a conventional chisel head represented by the dashed lines C.

FIG. 27 shows, through the section along the section line XXV-XXV, a further embodiment of the chisel head 50 shown in FIG. 24. The chisel head 50 is formed on the side face 54 analogously to the sectional illustration in FIG. 25 and has U-shaped recesses 61 which are formed by Crosspieces or ribs 41 are limited. On the rear side surface 55, the chisel head 50 has ribs or webs 41 opposite the U-shaped recesses 61. The ribs or webs 41 arranged on the front side surface are opposite recesses 57 on the rear side surface 55. Thus, the chisel head 50 has a cross-sectional shape similar to that of a stiffened sheet.

The invention is not restricted to the exemplary embodiments described above. Rather, it also includes design variants within the scope of the property right claims. LIST OF REFERENCE NUMBERS

1 chisel

2 clamping

3 chisel shank

4 chisel head

5 engagement grooves

6 rib or web

6a surface

7 recess

8 long edge

9 Chisel longitudinal axis

10 transition

11 transition

12 groove

12a longitudinal groove

13 end

14 end

15 end

16 circular area

17 cross-sectional area

18 trough-shaped recess

19 reinforcement rib

19a rib profile

20 part-circular recess

21 circle

22 circle

23 polygonal profile

24 triangular profile

25 U-shaped recess

25 V-shaped cross section

26 splined profile 40 chisels

41 bridge or rib

42 level

50 chisel head

51 chisel shank

52 flat chisels

53 cutting edge

54 front side surface

55 rear side surface

56 neck

57 recess

58 elliptical cross section

59 main axis

60 chisel longitudinal axis

61 U-shaped recess

62 longitudinal axis

63 shock wave

64 edge area

65 triangular recess

66 basic page

67 detour

68 pointed chisels

69 cone-shaped side surface

70 cutting tip

71 V-shaped recess

72 chisel 72a cutting surface 72b cutting surface

73 survey

74 U-shaped elevation

75 surface

76 bisectors

77 surface line

78 elliptical projection

79 teardrop-shaped recess

80 mid-range 81 triangular survey

82 edge area

83 edge area

84 middle section

85 rib

86 Chisel head cross section

87 profile bar

88 wing profile

89 Longitudinal chisel plane

89 'Chisel transverse symmetry level

90, 91 wings

90a top

90b bottom

91a top

91b bottom

92 fuselage area

93 circle

94 core

95 tangent

96, 97 joint

98 level

99 humps

100 cross wings

Claims

Expectations:

1. Chisel with a chisel head, a chisel shank and a clamping shank, in particular flat or pointed chisels, preferably for use in a rotary or chisel or percussion hammer, characterized in that the chisel shank (3, 51) and / or the chisel head (4, 50) has recesses (7, 57) and / or ribs (6) or webs (6).

2. Chisel according to claim 1, characterized in that axially extending recesses (7, 57) and / or ribs or webs (6) parallel to a longitudinal axis of the chisel (9, 60) and / or in a side surface (54, 55) of the chisel head (4, 50).

3. Chisel according to claim 1, characterized in that the recesses (7, 57) a part-circular (20), U-shaped

(25), V-shaped (25a) or trough-shaped cross-section (18), the recesses (5, 57) preferably being delimited laterally by ribs or webs (6).

4. Chisel according to one of the preceding claims, characterized in that the recesses (7, 57) are arranged symmetrically or asymmetrically in the chisel head (4, 50) and / or in the chisel shank (3, 51) to one another.

5. Chisel according to one of the preceding claims, characterized in that the recesses (7, 57) with rounded longitudinal edges (8) merge into a chisel surface (6a) and / or into adjacent webs or ribs (6).

6. Chisel according to one of the preceding claims, characterized in that the recesses (7, 57) are formed with open ends (15, 13 ') or closed ends (13, 14), preferably closed ends (13, 14) merge into the chisel surface (6a).

7. Chisel according to one of the preceding claims, characterized in that the recesses (7, 57) in the chisel shaft (3, 51) and / or in the chisel head (4, 50) are formed by an axially extending longitudinal groove (12a).

8. Chisel according to one of the preceding claims, characterized in that the longitudinal grooves (12a) extend over the entire or almost the entire chisel shank (3, 51).

9. Chisel according to one of the preceding claims, characterized in that the longitudinal grooves (12a) are axially spaced as longitudinal groove sections or offset on the circumference of the chisel shank (3, 51).

10. Chisel in particular according to one of the preceding claims, characterized in that the chisel head (4, 50) on a lateral surface (69) or at least one side surface (54, 55) of at least two ribs or webs (6) delimited recesses (57 ) having.

11. Chisel according to one of the preceding claims, characterized in that the chisel head (4, 50) on at least one side surface (54, 55) has at least one pocket-shaped, in the top view in particular approximately triangular (65) or V-shaped (71) or has elliptical (58) or U-shaped (61) or circular recess (57).

12. Chisel according to one of the preceding claims, characterized in that the axes of symmetry (62, 66) of the recesses (57) on the chisel head (4, 50) are arranged parallel or at an angle (α, β) to the longitudinal axis of the chisel (9, 60) are.

13. Chisel according to one of the preceding claims, characterized in that the recesses (57) on the chisel head (4,50) have a geometric orientation in the direction of the shock wave course.

14. Chisel according to one of the preceding claims, characterized in that the chisel head (4, 50) of a flat or spade chisel (52) stiffening by bead-like on the side surfaces (54, 55) opposite webs or ribs (41) and recesses or depressions (57).

15. Chisel according to one of the preceding claims, characterized in that at least two ribs (6) or webs (6) of the chisel shaft (3) are designed as wings (90, 91) or transverse wings (100).

16. Chisel according to one of the preceding claims, characterized in that the wings (90, 91) have upper sides (90a, 91a) and / or lower sides (90b, 91b), the tangents (95) to a preferably circular-cylindrical core (94) form.

17. Chisel according to one of the preceding claims, characterized in that the upper sides (90a, 91a) and / or lower sides (90b, 91b) of the wings (90, 91) at abutments

(96, 97) form cusps (99) or transverse wings (100).

18. Chisel in particular according to one of the preceding claims, characterized in that the chisel head (4, 50) has at least one rib (6) or a web (6) on a lateral surface (69) or at least one side surface (54, 55) , which is designed as a crusher edge and / or additional stiffening.