Rotatable tool with axially adjustable stop sleeve, especially countersink

Abstract

A rotationally drivable tool comprising a core part (2) which is rotatably drivable about a rotational axis (1), which has a drive section (3) at one axial end and a working section (4) at the other axial end, and a fastening section (5) arranged between these sections (3, 4) for an adjusting sleeve (15), which can be fastened to the core part (2) in different axial positions by means of a locking member (17, 31) and which carries, on its side facing the working section (4), a stop sleeve (22) which has a substantially cylindrical wall (24) and is rotatable relative to the adjusting sleeve (15) and partially overlaps the working section (4), wherein the wall (24) of the stop sleeve (22) has one or more windows (23) which, when the stop sleeve (22) rotates with the rotating core part (2), allow a transparent axial zone to appear, allowing a clear view of the working section (4), characterized in thatthat the stop sleeve (22) made of plastic is pressed onto a tubular holding extension (19) of the adjusting sleeve (15) and the tool is designed as a screw tool holder in which the core part (2) has a hexagonal cavity in which a bit is inserted.,

Description

[0001] The invention relates to a rotationally drivable tool, with a core part which can be driven in rotation about a rotation axis and which has a drive section at one axial end and a working section at the other axial end and a fastening section arranged between these sections for an adjusting sleeve which is fastened to the core part in different axial positions by means of a locking element and which carries a stop sleeve which has an essentially cylindrical wall on its side facing the working section and which partially overlaps the working section and rotates with the rotating core part.

[0002] US 2,429,375 discloses a drill with a countersink, wherein an end portion of a stop sleeve has a window. EP 1 721 692 A1 also discloses a combination of a drill and a countersink. US 2,223,485 discloses a tool with an adjusting sleeve and a stop sleeve attached thereto. The stop sleeve has several windows that are open toward the free end of the stop sleeve. DE 85 34 297 U1 discloses a tool with a hexagon opening that can be inserted into a drill chuck.

[0003] A stop device is known from DE 101 54 434 B4. A core part has a clamping section for clamping into a drill chuck. This drive section is followed by a fastening section on which a pivot bearing sits. A stop sleeve is attached to the core part by means of the pivot bearing. The core part has an axial bore into which a drill shank can be inserted. It is held there by a grub screw. A working section is attached to the drill. This section consists of a countersink. The countersink is also attached to the drill with a grub screw.

[0004] DE 25 49 153 A1 describes an attachment for hand drills for driving screws. A screwdriver bit is inserted into a polygonal recess of a working section. A drive section is formed by a shaft that can be inserted into the chuck of a drill. An adjusting sleeve is screwed onto a threaded section located between the working section and the drive section, forming a fastening section, and is secured there by a lock nut. The front end of the adjusting sleeve forms a stop sleeve, which, like the sleeve in the previously described DE 101 54 434 B4, forms a depth stop.

[0005] A similar bit holder is described in EP 163 37 285 A1. There, a permanent magnet is additionally arranged in the front area of the stop sleeve.

[0006] Such a magnet arrangement is also described in DE 199 07 837 A1, in which the combined adjusting-stop sleeve screwed onto an external thread of a bit holder is fixed by a lock nut with a rubber ring in between.

[0007] The invention is based on the object of further developing a tool mentioned at the outset in a manner that is advantageous in use.

[0008] The problem is solved by the invention specified in claim 1

[0009] It is provided that the wall of the stop sleeve has one or more windows. These windows are arranged in such a way that they create a transparent axial zone when the stop sleeve rotates. This transparent axial zone allows a clear view of the working section. Preferably, several windows are arranged in the region of the cylindrical wall. The plurality of windows can be arranged in the circumferential direction and with a uniform angular distribution. However, they can also be located at different axial heights. In a preferred embodiment, the one or more windows are open at the edge of the stop sleeve assigned to the working section. The edge of the window preferably runs along a U-shaped contour line. The circumferential width of the windows preferably corresponds to the circumferential width of the spaces between the windows.In a particularly preferred embodiment, the stop sleeve has three or four end-face incisions, between which opaque window spaces are arranged. These incisions form the open-edged windows mentioned above. The stop sleeve is rotationally entrained by the rotationally driven core part via the adjusting sleeve. The stop sleeve is connected to the adjusting sleeve in such a way that relative rotation, even if stiff, is possible between the stop sleeve and adjusting sleeve. The stop sleeve is pressed onto the adjusting sleeve in such a way that it is captively fastened there. This is achieved by the connection between the adjusting sleeve and stop sleeve being formed by a positive fit that can only be broken by destruction. If the front, open-edged end edge of the stop sleeve strikes a workpiece, the stop sleeve is braked, while the adjusting sleeve, which is firmly connected to the core part, can continue to rotate.The stop sleeve is made of plastic and sits on a collar of the adjusting sleeve. It is pressed onto a tubular extension of the adjusting sleeve. A clamping shaft forms a drive section, with which the core part can be clamped into the chuck of a drill. The clamping section can be a hexagon into which the shaft of the drill can be inserted. The clamping shaft can have a hexagonal profile so that it can be inserted into a hexagonal cavity of a bit holder. The tool is designed as a screw tool holder. The core part has a clamping shaft. This is surrounded by a metal sleeve, within which the shaft is attached and a magnet is located. The magnet forms the base of a hexagonal cavity into which a hexagonal section of the bit can be inserted. An external thread is screwed onto the outer surface of the component forming this cavity.The adjusting sleeve, along with the stop sleeve attached to it, is screwed onto this external thread. Axial fixation is achieved with a lock nut, which is also screwed onto the external thread. A rubber ring is preferably placed between the lock nut and the stop sleeve.

[0010] The tool according to the invention is characterized by a special stop sleeve. This does not need to be made of a transparent material. Even if the stop sleeve is made of an opaque material, a cylindrical zone is formed in the rotary operating state, which appears transparent due to the rapid rotation. This transparent axial zone allows a clear view of the working section.

[0011] To prevent the stop sleeve from becoming detached from the adjusting sleeve during operation, an alternatively designed stop sleeve has a radially inward-facing collar that lies in an annular groove in the adjusting sleeve. The base of the annular groove is formed by the retaining extension. One wall of the annular groove is formed by a collar of a press ring that is pressed into an opening widening in the adjusting sleeve. In a further development of the invention, the edge region of the stop sleeve that comes into contact with the surface of the workpiece is made of a soft material. This soft zone can be formed from a soft lacquer or a soft plastic part. For this purpose, the stop sleeve can also be manufactured using a two-component injection molding process. In a preferred embodiment of the invention, the edge of the stop sleeve facing the workpiece is provided with a soft material zone, for example made of rubber or plastic.This soft material zone contacts the surface of the workpiece. Because it is soft and, in particular, has low frictional resistance to the workpiece surface, the workpiece is not damaged. In a preferred embodiment, the soft material zone is formed by a ring. The latter can have a groove into which the edge of the adjusting sleeve is inserted.

[0012] Examples of rotary tools are explained below using the attached drawings. They show: Fig. 1 the side view of a first embodiment (not according to the invention but with a stop sleeve 22 according to the invention), Fig. 2 the bottom view of a first embodiment, Fig. 3 a perspective view of the first embodiment in the non-rotationally driven state, Fig. 4 a perspective view of the first embodiment in the rotationally driven state, in which a quasi-transparent axial section spanning the working section is formed, Fig. 5 a section along the line VV in Fig. 1, Fig. 6 a section along the line VI-VI in Fig. 1, Fig. 7 an exploded view of the parts of the first embodiment, Fig. 8 a cut similar to the cut according to Fig. 6 of a second embodiment (not according to the invention but with a stop sleeve 22 according to the invention), Fig. 9 a cut similar to the cut of the Fig. 6 of a third embodiment according to the invention, Fig. 10 is a perspective view of a fourth embodiment in the form of a countersink (not according to the invention but with a stop sleeve 22 according to the invention), Fig. 11 a section along the line XI-XI in Fig. 10, Fig. 12 a section through an adjusting sleeve with associated stop sleeve of a further embodiment according to the invention, Fig. 13 shows a sectional view of a further embodiment of an adjusting sleeve provided with a stop sleeve according to the invention, Fig. 14 in perspective view the adjusting sleeve together with stop sleeve (not according to the invention but with a stop sleeve 22 according to the invention) according to Fig. 13, mounted on a core part, and Fig. 15 in a sectional view the interaction of the tool according to Fig. 14 with a workpiece.

[0013] In the Fig. The embodiment shown in Figures 1 - 6 is a countersink. The countersink consists of a core part 2, which is rotatable about a rotation axis 1. For rotational drive, the core part 3 has a drive section 3. This is designed as a hexagonal shaft. The drive section 3 is formed by one axial end of the core part 2. The other axial end of the core part 2 forms a working section 4. In the Fig. In the embodiment shown in Figures 1-7, the working section 4 is formed by a total of three cutting edges 8, which meet at a point and otherwise extend along the lateral surface of a cone. Chip flutes 9 extend between the three cutting edges 8. A reduced-diameter neck section 10 is axially spaced from the countersink head 4 formed in this way. A fastening section 5 is axially spaced from the neck section 10.

[0014] The fastening section 5 forms the largest diameter area of the core part 2 and carries an external thread 7. The external thread is interrupted by a total of three flats 6, wherein the flats 6 extend along the sides of an equilateral triangle lying in the cross-sectional plane of the core part 2. Rearward of the external thread 7 is a reduced-diameter cylindrical section 11, which merges into the aforementioned drive section 3, forming a truncated cone zone.

[0015] An adjusting sleeve 15, made of brass, has an internal thread 18 that can be screwed onto the external thread 7. In the area of the internal thread 18, the adjusting sleeve 15 has a radial bore 16 with an internal thread. A grub screw 17 is screwed into this radial bore 16, the tip of which can be turned against one of the flats 6.

[0016] A tubular retaining extension 19 adjoins the threaded portion of the adjusting sleeve 15 on the side facing the working section 4. This retaining extension 19 has a bevel 21 on its end face and, spaced therefrom, forms a step 20 opposite which a shoulder 29 is located. Overall, the retaining extension 19 forms an annular recess onto which a fastening section of a stop sleeve 22 can be slipped.

[0017] The stop sleeve 22 is made of a non-transparent plastic. It has a cylindrical wall 24 interrupted by windows 23. The edge 25 of the stop sleeve 22, facing toward the working section 4, has a total of three notches that form the said windows 23. The edge 23' of each window 23 extends along a substantially U-shaped contour line. The circumferential width of each of the three windows, which are evenly spaced circumferentially, is approximately the same size as the circumferential width of the gaps between the windows in the cylindrical section 24. However, four or more windows can also be provided instead of three windows.

[0018] The end face 28 of the stop sleeve 22, opposite the edge 25, lies in front of the shoulder 29 when assembled. In this area, the stop sleeve 22 forms a locking shoulder 26, which lies in front of the step 20. A bevel 27, adjacent to the end face 28, acts together with the bevel 21 as an assembly aid when the stop sleeve 22 is pressed onto the retaining extension 19. It sits there in a snap-locked, tight clamp fit. The stop sleeve 22 is captively attached to the retaining extension 19 with a positive fit.

[0019] However, the stop sleeve 22 is connected to the adjusting sleeve 15 in the circumferential direction in such a frictional manner that it can be rotationally dragged by the adjusting sleeve 15. If the edge 25 of the stop sleeve 22 strikes a workpiece, the rotational movement of the stop sleeve 22 is inhibited. This can occur until the stop sleeve 22 comes to a standstill. Since the locking connection between the stop sleeve 22 and the adjusting sleeve 15 allows relative rotation of both parts, the adjusting sleeve 15 can continue to rotate. Due to the connection of the adjusting sleeve 15 to the core part 2 via the grub screw 17, the adjusting sleeve 15 is connected to the core part 2 in a rotationally fixed manner. The stop sleeve 22 is, however, also fundamentally rotatably connected to the adjusting sleeve 15 via the rotationally symmetrical form-fitting connection.

[0020] The Fig. The second embodiment shown in Figure 8 differs from the first embodiment essentially only in that the core part 2 has an axial bore 12. A drill 33 is inserted into this axial bore 12. The drill is held by means of a grub screw 30 which is screwed into a threaded bore 13 in the drive section 3 of the core part 2. The threaded bore 13 is located in the larger-diameter cylinder section 11 described above. The tip of the grub screw 30 clamps itself to the outer wall of the shaft of the drill 33, so that the core part 2 is connected to the drill 33 in a rotationally fixed manner.

[0021] In this embodiment, the axial position of the adjusting sleeve 15 relative to the core part 2 can also be adjusted by loosening the grub screw 17 and then rotating the adjusting sleeve 15 relative to the external thread 7. Along with this, the edge 25 of the stop sleeve 22, which defines the insertion depth of the countersink head 4, is also displaced in the axial direction.

[0022] The Fig. The third embodiment shown in Figure 9 is illustrated as a bit holder. Adjusting sleeve 15 and stop sleeve 22 essentially correspond to the components designated by the same reference numerals in the two previously described embodiments. Unlike there, however, the adjusting sleeve 15 is held with a lock nut 31 screwed onto the external thread 7. A rubber ring 32 is arranged between the lock nut 31 and the front edge of the adjusting sleeve 15, which elastically deforms against the adjusting sleeve 15 when the lock nut 31 is screwed on.

[0023] The core part 2 is formed by a bit holder, as described, for example, in DE 199 07 837 A1. A magnet is located within the core part 2. The magnet forms the base of a hexagonal insertion opening for the bit 4, which forms the working section 4.

[0024] This design also allows an unrestricted view of the working section 4, i.e., the bit, while the tool is rotating. In this embodiment, the edge 25 of the stop sleeve 22 also forms a depth stop. Its axial position relative to the bit 4 defines the screw-in depth of a screw.

[0025] Instead of the bit, the hexagonal cavity of the Fig. 9 but also a countersink can be inserted, as shown in the Fig. 11. There, the working section 4 is not formed by a bit, but by a countersink head that forms cutting edges 8. The countersink head has a rear hexagonal section 34 that fits into a correspondingly designed hexagonal bore in the fastening section 5. This makes it possible to connect countersink heads of various designs to the fastening section. The cavity 35 can form an annular groove 37 in which a clamping ring is inserted in order to hold the hexagonal section 34 frictionally in the cavity 35. Alternatively, form-locking means, such as balls, can be provided that fit into corresponding recesses in the hexagonal section. Furthermore, it is possible to hold the hexagonal section 34 in the cavity 35 by means of a magnet.

[0026] In the Fig. 10 and Fig. In the fourth embodiment shown in Figure 11, the working section 4 formed by a countersink has an axial cavity 12 into which a drill 33 can be inserted. For axial fixation of the drill 33, the working section 4 has a radial bore 13 into which a grub screw 30 is screwed, which can be screwed against the shaft of the drill 33. The axial cavity 12 is aligned with an axial cavity 36 of the fastening section 5 or the drive section 3. This latter axial cavity 36 originates from the bottom of the polygonal cavity 35 and is designed as a blind bore. However, it can also be formed as a through-bore through the polygonal section of the drive section 3.

[0027] Between the adjusting sleeve 15 and the lock nut 31, an elastic ring 32 is provided. This can be formed by a rubber ring, as in the previously discussed embodiment. However, this ring 32 is preferably formed by a plastic ring that surrounds the external thread 7 at a radial distance. The material thickness of the ring can be approximately 3 mm. Its inner diameter is preferably 10 mm, its outer diameter preferably 15 mm. The ring can be made of plastic, in particular polyamide, but it can also be made of steel, brass, or aluminum. The Fig. The embodiment shown in Figure 9 can be equipped with such a ring.

[0028] Instead of the Fig. 10 and Fig. 11, a grub screw can also be used to fix the adjusting sleeve 15 to the fastening section 5.

[0029] Even in the Fig. In the embodiment shown in Figures 1 to 7, the core part 2 can be constructed in several parts. There, too, the working section 4 can be detachably connected to the fastening section 5. Here, too, a hexagonal plug connection can be provided to connect the working section 4 to the fastening section 5. However, it is also possible to provide a screw connection.

[0030] The Fig. Figure 12 describes another embodiment of an adjusting sleeve 15 and a stop sleeve 22 connected thereto. The stop sleeve has a soft zone at its edge 25 facing the workpiece. This soft zone can be formed by a softer plastic injection-molded there. It is also possible for the soft zone to be formed by a molded part that is positively connected to the rest of the body of the stop sleeve 22. However, the soft sleeve can also be formed by a lacquer.

[0031] In this embodiment, the stop sleeve 22 has a radially inwardly projecting collar 40 at its end opposite the edge 25, with which the stop sleeve 22 is connected to the adjusting sleeve 15. The collar 40 engages in an annular groove in the adjusting sleeve 15. The bottom of the annular groove is formed by the holding extension 19. Essential is a press ring 38 pressed into the opening of the adjusting sleeve 15. This forms a collar 39, which forms the wall of the aforementioned annular groove. As a result of this design, the stop sleeve 22 is positively and permanently connected to the adjusting sleeve 15. The connection does not come loose even if the stop sleeve 22 heats up during operation.

[0032] In the Fig. In the embodiment shown in Figures 13 to 15, the edge 25 of the adjusting sleeve 22 is inserted into a circumferential groove 42 of a ring 41. The ring can be made of rubber, Teflon, or another suitable material, for example, plastic. The material of the ring 41 is preferably soft. However, the ring particularly preferably has a surface that exhibits only low frictional resistance to the surface of the workpiece 44. The edge 25 can be glued to the bottom of the groove 42. However, it can also be manufactured with a slight oversize, so that it is inserted into the groove 42 in a clamping connection.

[0033] The Fig.Figure 15 shows a typical operating position. The working section 4 is designed as a countersink. A countersink has been created in a bore 43 using the countersink 4. The surface of the ring 41 facing the end face of the ring 41 is in contact with the surface of the workpiece 44. Since the surface of the ring 41 is soft and develops only low friction, no unsightly marks are left on the workpiece surface.

[0034] In the latter embodiment, the adjusting sleeve 15 is fixed to the core part 2 with a thread. This is advantageous in this and the previously described embodiment. However, it is also possible to dispense with the threaded connection in all embodiments and simply clamp the adjusting sleeve 15 to the core part, for example, using a radially screwable grub screw.

[0035] All disclosed features are (in themselves) essential to the invention. The disclosure of the application hereby fully incorporates the disclosure content of the associated / attached priority documents (copy of the prior application), also for the purpose of incorporating features of these documents into the claims of the present application.

Claims

[1] A tool capable of rotation, comprising a core part (2) which is capable of rotation about a rotational axis (1), which has a drive section (3) at one axial end and a working section (4) at the other axial end, and a fastening section (5) arranged between these sections (3, 4) for an adjusting sleeve (15), which can be fastened to the core part (2) in different axial positions by means of a locking member (17, 31) and which carries, on its side facing the working section (4), a stop sleeve (22) which has a substantially cylindrical wall (24) and is rotatable relative to the adjusting sleeve (15) and which partially overlaps the working section (4), wherein the wall (24) of the stop sleeve (22) has one or more windows (23) which, when the stop sleeve (22) rotates with the rotating core part (2), allow a transparent axial zone to appear, allowing a clear view of the working section (4), characterized bythat the stop sleeve (22) made of plastic is pressed onto a tubular holding extension (19) of the adjusting sleeve (15) and the tool is designed as a screw tool holder in which the core part (2) has a hexagonal cavity in which a bit is inserted. [2] Tool according to claim 1, characterized by that the one or more windows (23) are open at the edge of the stop sleeve (22) associated with the working section (4). [3] Tool according to one of the preceding claims, characterized by several, in particular three, windows (23) arranged at a uniform angular distribution around the axis of rotation (1). [4] Tool according to one of the preceding claims, characterized by that the edge (23') of the at least one window (23) runs on a U-shaped contour line. [5] Tool according to one of the preceding claims, characterized bythat the circumferential width of the windows (23) essentially corresponds to the circumferential width of the spaces between the windows. [6] Tool according to one of the preceding claims, characterized by that the fastening section (5) has an external thread (7) onto which an internal thread (18) of the adjusting sleeve (15) is screwed.

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