Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D16/00—Portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
  • B25D16/003—Clutches specially adapted therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2250/00—General details of portable percussive tools; Components used in portable percussive tools
  • B25D2250/165—Overload clutches, torque limiters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2250/00—General details of portable percussive tools; Components used in portable percussive tools
  • B25D2250/195—Regulation means
  • B25D2250/205—Regulation means for torque

Definitions

• Hand tool in particular drilling and / or Schlaqhammer
• the invention relates to a hand tool, in particular a drill and / or percussion hammer, according to the preamble of claim 1.
• Known handheld power tools of this type are provided with a safety coupling, which allows the operator to stop the power tool abruptly, e.g. when jamming a drilling tool, to protect against too high a reaction torque.
• Tool holder preferably integrally supporting inner hammer tube part, which is inserted with an end portion slidably inserted into the outer hammer tube part, effective.
• the Studentsrastkupplung has a plurality of over the circumference of the hammer tube equidistantly arranged locking balls, which engage radially displaceable and form-fitting in holes of the outer hammer tube part and tangentially positively tangentially positively immerse in the end portion of the inner hammer tube portion formed axial and on the other hand radially project beyond the circumference of the outer hammer tube portion ,
• An axially displaceably arranged on the outer hammer tube part coupling ring is pressed by a trained as a compression spring clutch spring with an inner cone on the projecting portion of the detent ball, whereby the detent balls radially acting force component is generated, which determines the limit torque of Studentsrastkupplung.
• the detent balls When exceeding this limit torque, the detent balls are pressed against the force of the coupling ring acting on the coupling spring radially outward, move the coupling ring against the force of the clutch spring and emerge from the axial recesses in inner hammer tube part off. Thereby, the connection of outer and inner hammer tube part is separated, and the outer hammer tube part can rotate freely on the inner hammer tube part, which is held over the tool in the workpiece, for example.
• the rotary drive of the hammer tube via the rotatably mounted on the outer part of the hammer tube drive gear, which is designed as a bevel gear and is driven by a reduction gear by an electric motor.
• the hammer tube is made in one piece and carries at its front end preferably integrally the tool holder.
• On the hammer tube which in turn is formed as a bevel gear drive gear, which is driven by a reduction motor of an electric motor.
• the hammer tube is either with the drive gear rotatably connected (operating mode impact drilling or drilling) or non-rotatably mounted on the housing (chiseling mode).
• the Studentsrastkupplung is arranged in a gear stage of the reducer.
• the hand tool of the invention with the features of claim 1 has the advantage that the novel Matterrastkupplung is compact and robust and can be realized with low-cost components.
• the hand tool can be equipped without structural changes of Matterrastkupplung both with a relative to the housing axially immovable and with a relative to the housing axially displaceable hammer tube, the hammer tube can be made one or more parts. Since the Kochrastkupplung is arranged even with a one-piece hammer tube on the hammer tube itself - and not as in the known hand tool with a one-piece hammer tube in the reducer - the Matterrastkupplung works at the low hammer tube speed, so that significantly longer service life of Studentsrastkupplung be achieved with constant torque. Also, the catching of the clutch is due to the lower speed much less wear intensive than in the known hand tool with arranged in the transmission overrunning clutch.
• the coupling sleeve of the novel Matterrastkupplung can be easily expanded into a multi-functional part by next to the actual coupling function still a bearing function for the hammer tube, a control function for the percussion and a carrier function for a switching ring for switching the operating modes "drilling" or "Schlagbohren ",” Chisel “and” Neutral "can be assigned.
• the slidably seated on the hammer tube coupling sleeve is received in a fixed bearing in the housing, so that the coupling sleeve also assumes a bearing function for the hammer tube.
• the plain bearing can be used in accordance with an embodiment of the invention explained below for controlling the striking mechanism.
• the coupling between the coupling sleeve and drive gear by means of a on the
• Coupling sleeve seated switching rings made with axial toothing.
• the axial toothing engages with an axial toothing formed on the coupling sleeve, preferably in a rear sleeve section facing away from the coupling ring.
• the switching ring can be coupled by axial displacement either with the drive tooth edge or the housing in a rotationally fixed manner.
• the coupling sleeve also assumes carrier function for the switching ring for switching the operating modes of the power tool.
• the hammer tube is axially displaceably mounted in the housing against the force of a return spring and limits the axial displacement by means of two stops formed on the housing and a counter-stop formed on the hammer tube.
• the front stop sets at axially unloaded hammer tube an idle position and the rear stop defines a working position for the hammer mechanism with axially loaded hammer tube. This makes it easy to idle the impactor by removing the contact pressure from the tool, e.g. by lifting or lifting the hand tool from the workpiece cause.
• the percussion mechanism is designed as Gutpolster Farbwerk and has a guided in the hammer tube, translationally driven piston and a piston spaced axially displaceable in the hammer tube, acting on the tool firing pin, wherein in the hammer tube of the piston and firing pin an air cushion is included.
• congruent radial bores are provided in the hammer tube and in the coupling sleeves whose arrangement is adapted to the displacement of the hammer tube so that they are covered in the working position of the hammer tube from the sliding bearing and pushed out in the idle position of the hammer tube from the sliding bearing and thus are open.
• FIG. 1 is a schematic side view of a hand tool, partially cut
• FIG. 2 shows a detail of a longitudinal section of the power tool in FIG. 1 with a hammer tube located in the working position
• FIG. 3 is a same view as in Fig. 2 with befindlichem in idle position hammer tube,
• Fig. 4 is an enlarged view of the detail IV in Fig. 2 at
• the machine tool shown schematically in FIG. 1 in side view and in the scope of interest here also in longitudinal section is called a hammer drill and / or percussion hammer, also known as a combination hammer. It has a housing 11 which contains a particular electric drive motor 12, which works via a gear 13 on a downstream drilling and / or impact mechanism. For this purpose, the gear 13 is in engagement with a drive gear 14, which is coupled to the rotary drive of a hammer tube 15 with this.
• the drive gear 14 is preferably formed as a bevel gear.
• the drive motor 12 and the gear 13 are on the drive gear 14, the hammer tube 15 and by means of this a tool holder 16, in which a tool 17 is held non-rotatably and axially displaceable, rotationally driven.
• a percussion mechanism 18 via the gear 13 by means of an upstream crank mechanism 19 driven in translation.
• a piston 20 reciprocally driven by the crank mechanism 19 and one of which is spaced apart from the piston 20 an air cushion 22 enclosing bat or firing pin 21, and a striker 21 in the hammer tube 15 downstream striker 23, which acts directly on the tool holder 16 held in the tool 17.
• Piston 20, striker 21 and striker 23 are axially displaceably guided in the hammer tube 15 and sealed against the inner wall of the hammer tube 15 airtight.
• a Botrastkupplung 24 is provided which separates the drive connection between the drive gear 14 and the hammer tube 15 when a limit torque is exceeded.
• the coupling 24 is z. B. designed as Kochrastkupplung.
• the fürrastkupplung 24 is shown in Fig. 2 and 3 only with the upper half-section.
• the fürrastkupplung 24 has two, by means of torque transmitting transmission elements in engagement coupling parts which are latched when a predetermined limit torque against a force is exceeded.
• the one coupling part is slidable from the hammer tube 15 or a part connected to the hammer tube 15 and the other coupling part from one on the hammer tube 15 seated coupling sleeve 25 is formed.
• the transmission elements are formed by locking balls 26 which are offset by equal circumferential angle to each other in radial bores 27 in the coupling sleeve 25 are guided radially displaceable.
• the radial bores 27 have a bore diameter which is slightly larger than the ball diameter of the detent balls 26.
• the detent balls 26 dive on the one hand in frustoconical detent recesses 28, which are offset by the same circumferential angle as the radial bores 27 in the coupling sleeve 25 in the hammer tube 15, and on the other hand project radially beyond the outer sleeve wall of the coupling sleeve 25.
• the conical locking recesses 28 have a decreasing to the bottom of the locking recesses 28 clear cross-section, wherein the cross section corresponds to the coupling sleeve 25 facing the bore hole cross-section of the radial bores 27 in the coupling sleeve 25.
• a coupling ring 29 which sits axially displaceable on the coupling sleeve 25, has an inner cone 291, with which he under the action of a clutch spring 30 on the
• the clutch spring 30 is formed for example as a compression spring which concentrically surrounds the hammer tube 15 and on the one hand on the coupling ring 29 and the other hand supported on the hammer tube 15 and the inner cone 291 the locking balls 26 acted upon by a radial force component, the locking balls 26 in the
• the hammer tube 15 is rotatably mounted in the housing 1, in its the tool holder nahname, front area by means of a housing 11th fixed pivot bearing 35 and in its rear region by means of a near the Matterrastkupplung 24 arranged plain bearing 36 which is also fixed in the housing 11 and the coupling sleeve 25 receives.
• the coupling sleeve 25 is provided in a side facing away from the coupling ring 29, the rear sleeve portion with an axial toothing 37 (FIG. 4), which meshes with a similar axial toothing 38 of an intermediate ring 46.
• the intermediate ring 46 forms the radial distance to a drive gear 14 formed on the axial toothing 47.
• the coupling sleeve 25 is fixed to the housing 11, and if the switching ring 39 is displaced to the right in FIG. 2, the coupling sleeve 25 is connected in a rotationally fixed manner to the drive gear 14.
• the hammer tube 15 is housed axially displaceable in the housing 11 against the force of a return spring 35 in the pivot bearing 35 and the plain bearing 36, wherein the axial displacement of the hammer tube 15 is limited by means of two formed on the housing 11 attacks and a trained on the hammer tube 15 counter-attack.
• rear stop which is formed by an annular shoulder 41 formed in the housing 11 is, specifies the working position for the percussion mechanism 18 at axially loaded hammer tube 15.
• the axial load of the hammer tube 15 is effected by the axial pressing of the tool 17 to the workpiece.
• the arranged on the hammer tube 15 counter-stop is formed by the spring plate 32, at the up to the
• Inner wall of the housing 11 reaching Tellerrand itself as a compression spring trained and concentric with the hammer tube 15 and the clutch spring 30 arranged return spring 40 is supported.
• the counter bearing of the return spring 40 is formed by a formed in the housing 11 radial shoulder 42.
• radial bores 43 and in the coupling sleeve 25 are introduced into the hammer tube 15, which are congruent.
• the radial bores 43, 44 are arranged offset by the same circumferential angle to each other.
• the radial bores 43, 44 arranged in coordination with the displacement of the hammer tube 15 so that they are in the
• Striker 21 and allows a short culvert, which in turn ensures a good seal and a low wear of Döpperdfchtung 45.
• the hammer tube 15 is moved from the tool 17 via the striker 23 against the force of the tool 17 when the tool 17 is held in the tool holder 16 and the workpiece is pressed axially against the hand tool Return spring 40 pushed into the working position shown in Fig. 2.
• the switching ring 39 is shown in its neutral or zero position. If the switching ring 39 is shifted in Fig. 2 to the right, so the coupling sleeve 25 is rotatably coupled to the drive tooth edge 14.
• the hammer tube 15 is set in rotation via the rotating drive gearwheel 14 and the detent coupling 24, which rotatorily drives the tool 17 via the tool receptacle 16, which is connected to it in a rotationally fixed manner. If the predetermined by the clutch spring 30 limit torque exceeded, for example, the fact that the rotating tool 17 sets in the workpiece, the detent balls 26 are pressed out of the cone-like detent recesses 28 under axial displacement of the coupling ring 29 against the clutch spring 30 radially outward until they are out of the Locking recesses 28 in the hammer tube 15 emerge (Fig. 4) and now the coupling sleeve 25 can rotate relative to the hammer tube 15.
• the described one-piece hammer tube 15 and a two- or multi-part hammer tube in the housing 11 may be rotatably mounted and axially fixed or axially displaceable.
• the two hammer tube parts, of which the front hammer tube part integrally carries the tool carrier, inserted into one another, but now rigidly connected Compared with the known hand tool with two-piece hammer tube now to be produced hammer tube is much cheaper because the two hammer tube parts not rotate into each other and therefore not the contact surfaces of the hammer tube parts must be ground.
• the hammer tube 15 can also be arranged axially fixed and executed in one or more parts. Then, however, eliminates the simple, described above "sleeve control" for opening the air cushion space at the transition of the impact mechanism in the idle.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Percussive Tools And Related Accessories (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=35045137

Family Applications (1)

Country Status (5)

Cited By (1)

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Citations (9)

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• 2004
  • 2004-09-30 DE DE200410047470 patent/DE102004047470A1/de not_active Withdrawn
• 2005
  • 2005-07-22 WO PCT/EP2005/053584 patent/WO2006034899A1/de active Application Filing
  • 2005-07-22 JP JP2007533973A patent/JP4778516B2/ja not_active Expired - Fee Related
  • 2005-07-22 CN CNB2005800333827A patent/CN100544896C/zh not_active Expired - Fee Related
  • 2005-07-22 EP EP05771980A patent/EP1819486A1/de not_active Withdrawn

Patent Citations (9)

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