Flat chisel
Patent Information
- Application Number
- EP2023814468
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-07
- Filing Date
- 2023-11-30
- Publication Date
- 2025-10-15
AI Technical Summary
Chisels used for chiseling mineral rock, such as concrete, often become lodged in the rock, causing work interruptions and the accumulation of chisel dust, which necessitates frequent site clearing, leading to inefficiencies and increased costs.
A chisel design featuring a working section with wedge-shaped cutting edges and radially extending ribs, where the ribs are locally thickened, particularly in the foot area, creating a larger cross-sectional area that prevents jamming and facilitates dust removal by allowing continuous movement and dust ejection during chiseling.
The design minimizes work interruptions by preventing chisel jamming and improving dust removal, allowing uninterrupted chiseling even at considerable depths, thereby reducing downtime and maintaining productivity.
Smart Images
Figure 1.1
Abstract
Description
[0001] flat chisel
[0002] Description
[0003] The invention relates to a chisel having a working section, a shank section, an insertion end and a longitudinal axis extending through the working section, the shank section and the insertion end, wherein at least one wedge-shaped cutting edge and a rib extending parallel or at least substantially parallel to the longitudinal axis and pointing radially away from the longitudinal axis are formed on the working section.
[0004] Such chisels are used on construction sites for chiseling mineral rock, such as concrete. However, while chiseling at a work site, such a chisel can become stuck in the rock, resulting in work interruptions, lost time, and thus high costs. It may also be necessary to interrupt chiseling to clear the work site of chisel dust if excessive amounts of chisel dust remain or accumulate at the work site, particularly in a chiseled recess.
[0005] The object of the present invention is therefore to offer a chisel which enables work to be carried out as uninterruptedly as possible or at least with particularly few interruptions.
[0006] The object is achieved by a chisel which has a working section, a shank section, an insertion end and a longitudinal axis running through the working section, the shank section and the insertion end, wherein at least one wedge-shaped cutting edge and a rib running parallel or at least substantially parallel to the longitudinal axis and pointing radially away from the longitudinal axis are formed on the working section, wherein the rib is locally thickened in at least one rib region.
[0007] In the rib area, the rib thus exhibits a local thickening. This local thickening can be located, in particular, in the base area of the rib. The base area can correspond to a region of the rib facing the interior of the bit, particularly toward the longitudinal axis.
[0008] An inscribed ellipse of a cross-section of the rib region may have a larger area than an inscribed ellipse of a cross-section of a region of the bit immediately adjacent to the rib region.
[0009] A longitudinal plane of the chisel can also be regarded as the longitudinal axis, for example in the case of a non-rotationally symmetrical chisel such as a channel chisel.
[0010] Studies have shown that such a local thickening can create a clearance between the chisel and the wall of the recess, for example, when chiseling into recesses. The chisel can thus remain mobile even during prolonged chiseling in the recess and even at considerable depths within the recess. This can prevent the chisel from jamming, or at least significantly reduce the risk of such jamming, requiring fewer or no work interruptions to free a jammed chisel from the recess.
[0011] It has also been observed that the local thickening improves the removal of chisel dust. In particular, chisel dust generated during chiseling can, through its own movement, reach at least an area of the chisel above the local thickening, i.e., toward the insertion end, of the local thickening. Continuous forward and backward movements of the chisel along its longitudinal axis can further accelerate the chisel dust, particularly during a backward movement, so that it can be thrown into the open even from relatively deep recesses. The improved removal can also prevent work interruptions or at least reduce their frequency.
[0012] The chisel can be designed as a flat chisel. The chisel can have a cutting edge with a non-vanishing, i.e., finite, cutting edge width. The cutting edge width can be, for example, at least 0.5 cm. The cutting edge can be designed as a prism. The working section can taper along at least one dimension, at least toward the cutting edge.
[0013] It is conceivable that the working section tapers towards the cutting edge in at least two mutually perpendicular dimensions. The chisel can thus combine the advantages of flat chisels and pointed chisels, especially in conjunction with its wedge-shaped cutting edge.
[0014] The ribs can extend in multiple dimensions. In particular, four ribs can be formed on the working section, particularly parallel or at least substantially parallel to the longitudinal axis and pointing radially away from the longitudinal axis.
[0015] At least one of the ribs, several of the ribs, especially all of the ribs, may be locally thickened.
[0016] At least two, in particular two, of the ribs may extend as side ribs along a plane encompassing the longitudinal axis.
[0017] At least two, in particular two, of the ribs may extend as vertical ribs perpendicular or at least substantially perpendicular to the plane.
[0018] Thus, the at least two side ribs and the at least two height ribs can have a cross-shaped cross-section.
[0019] To further improve the chisel's function as a flat chisel, at least one of the vertical ribs can be lower in height than at least one of the side ribs. The height of a rib can be defined as the greatest distance of all points of a rib from the longitudinal axis. Apart from the height and orientation, the vertical ribs and the side ribs can be designed similarly on the chisel.
[0020] The lateral ribs can direct crack formation in the treated subsoil during chiseling. The vertical ribs can create additional stresses in the subsoil, thus further accelerating crack formation.
[0021] Such a local thickening can be formed on at least one of the lateral ribs. It is also conceivable, or alternatively, that such a local thickening is formed on at least one of the vertical ribs.
[0022] The chisel can be produced without cutting, in particular by plastic molding, and / or by machining. Further features and advantages of the invention will become apparent from the following detailed description of exemplary embodiments of the invention, based on the figures of the drawing, which show details essential to the invention, and from the claims. The features shown therein are not necessarily to scale and are presented in such a way that the special features of the invention can be clearly seen. The various features can be implemented individually or in groups in any combination in variants of the invention.
[0023] The schematic drawing shows embodiments of the invention and explains them in more detail in the following description.
[0024] They show:
[0025] Fig. 1 a chisel,
[0026] Fig. 2 a working section of the chisel in a side view,
[0027] Fig. 3 the working section of the chisel in a plan view,
[0028] Fig. 4 a cross-section of the chisel,
[0029] Fig. 5 a working section of another chisel, and
[0030] Fig. 6 to 8 Cross sections of the chisel according to Fig. 5.
[0031] In the following description of the figures, the same reference numerals are used for identical or functionally corresponding elements to facilitate understanding of the invention.
[0032] Fig. 1 shows a side view of a chisel 10. The chisel 10 is designed as a flat chisel. It has a working section 12, a shank section 14, and a striking surface 16. At the free end of its working section 12, the chisel 10 has a cutting edge 18.
[0033] A longitudinal axis L runs through the working section 12, the shaft section 14 and the striking surface 16.
[0034] The chisel 10 can be driven into a substrate 20 by striking its striking surface 16, for example, using a machine tool (not shown in Fig. 1) mounted in the area of the striking surface 16. In the example according to Fig. 1, the substrate 20 is a mineral substrate, for example, reinforced concrete.
[0035] In the embodiment of the chisel 10 shown in Fig. 1, the working section 12 has a plurality of ribs 22. To simplify the illustration, only one of the ribs 22 is provided with a reference symbol in Fig. 1.
[0036] Over the service life of the chisel 10, the working section 12 usually wears out, but not the shank section 14, or at most to an insignificant extent.
[0037] A shank portion 14 is formed with a shank end 24. In the embodiment shown in Fig. 1, the shank end 24 can be formed as a hexagon and / or comprise such a hexagon. Alternatively, it is also conceivable for the shank end 24 to conform to a different standard, for example, a standard commonly referred to as "SDS-Plus" or "SDS-Max."
[0038] Fig. 2 shows the working section 12 of the chisel 10 in a side view and Fig. 3 in a top view.
[0039] The working section 12 has a tip zone 26, a middle zone 28 and a transition zone 30.
[0040] In the tip zone 26, the cross-section of the chisel 10 decreases along the longitudinal axis L to the cutting edge 18.
[0041] The cutting edge itself is designed as a prism and thus has a non-vanishing, i.e. finite, cutting edge width s, for example in the range of 0.5 to 5 cm.
[0042] A total of four ribs 22 are formed on the working section 12. Two ribs 22 extend as vertical ribs 32 along the height dimension HD (see Fig. 2). Two ribs 22 extend as lateral ribs 34 along the width dimension BD (see Fig. 3). They thus extend along a plane E encompassing the longitudinal axis L. In the illustration according to Fig. 3, the plane E runs parallel to the image plane of Fig. 3.
[0043] The vertical ribs 32 thus extend perpendicular to the plane E. In this exemplary embodiment, the vertical ribs 32 on the one hand and the side ribs 34 on the other hand are each formed in pairs as a mirror image of each other.
[0044] In the central zone 28, the width of the chisel 10 is constant or at least substantially constant, particularly apart from locally limited changes in the ribs 22.
[0045] In the transition zone 30, the cross-section is continuously adapted to the adjacent shaft section 14.
[0046] As can be seen particularly in Fig. 3, the side ribs 34 are locally thickened in rib regions 36. In this embodiment, the rib regions 36 are located in the tip zone 26.
[0047] Fig. 4 shows a cross section according to the section line IV from Fig. 3 through the working section 12 of the chisel 10. It can be seen that the height ribs 32 have a lower height HH, in particular measured along the height dimension HD, than the side ribs 34, which have a height HS, measured along the width dimension BD.
[0048] Fig. 5 shows a plan view of a working section 12 of another chisel 10. This embodiment also has side ribs 34 that are thickened within rib regions 36. In this embodiment, however, the rib regions 36 are located in the central zone 28. Thus, the rib regions 36 are located in a section of the chisel 10 in which its overall width is constant or at least substantially constant.
[0049] Fig. 6 to Fig. 8 show cross-sectional views according to the section lines VI, VII and VIII respectively from Fig. 5 of the chisel 10 according to the embodiment corresponding to Fig. 5.
[0050] In foot regions 38, the side ribs 34 have the same thicknesses D1 along the section lines VI and VIII, as can be seen in Fig. 6 and Fig. 8.
[0051] In foot regions 38, the side ribs 34 have a thickness D2 along section line VII, as can be seen in Fig. 7. The thickness D2 along section line VII (see Fig. 7) is thicker than the thickness D1 along section lines VI and VIII (see Fig. 6 and Fig. 8). An ellipse inscribed in the cross-section according to Fig. 7 has a cross-sectional area of A2. Ellipses inscribed in the cross-sections according to Fig. 6 and Fig. 8 each have cross-sectional areas of A1. The cross-sectional area A2 is larger than the cross-sectional area A1. A minimum distance between section lines VI and VIII, i.e. a minimum distance within which the thickness of the respective ribs, here the side ribs 34, is locally thickened, can be a maximum of 5 cm.
[0052] List of reference symbols
[0053] 10 chisels
[0054] 12 work sections
[0055] 14 Shaft section
[0056] 16 Face
[0057] 18 cutting edges
[0058] 20 Underground
[0059] 22 rib
[0060] 24 shank ends
[0061] 26 peak zone
[0062] 28 Middle Zone
[0063] 30 Transition zone
[0064] 32 vertical rib
[0065] 34 side rib
[0066] 36 rib area
[0067] 38 foot area
[0068] A1 cross-sectional area
[0069] A2 cross-sectional area
[0070] BD width dimension
[0071] D1 Thickness
[0072] D2 thickness
[0073] E Level
[0074] HD height dimension
[0075] HH height
[0076] HS height
[0077] IV Cutting line
[0078] VI Cutting line
[0079] VII Cutting line
[0080] VIII Cutting line
[0081] L Longitudinal axis s Cutting width
Claims
Patent claims Chisel (10) having a working section (12), a shank section (14), an insertion end (24), and a longitudinal axis (L) running through the working section (12), the shank section (14), and the insertion end (24), wherein at least one wedge-shaped cutting edge (18) and a rib (22) running parallel or at least substantially parallel to the longitudinal axis (L) and pointing radially away from the longitudinal axis (L) are formed on the working section (12), characterized in that the rib (22) is locally thickened in at least one rib region (36). Chisel according to the preceding claim, characterized in that the chisel (10) is designed as a flat chisel. Chisel according to one of the preceding claims, characterized in that the working section (12) tapers towards the cutting edge (18) in two mutually perpendicular dimensions (BD, HD).Chisel according to one of the preceding claims, characterized in that four ribs (22) are formed on the working section (12), in particular running parallel or at least substantially parallel to the longitudinal axis (L) and pointing radially away from the longitudinal axis (L). Chisel according to one of the preceding claims, characterized in that two of the ribs (22) extend as lateral ribs (34) along a plane (E) encompassing the longitudinal axis (L). Chisel according to one of the preceding claims, characterized in that two of the ribs (22) extend as vertical ribs (32) perpendicular or at least substantially perpendicular to the plane (E). Chisel according to one of the preceding claims, characterized in that at least one of the vertical ribs (32) has a lower height (HH, HS) than at least one of the lateral ribs (34).