EP0539382B1 - Hand-held electrical machine tool, in particular angle grinding machine - Google Patents

Hand-held electrical machine tool, in particular angle grinding machine

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Publication number
EP0539382B1
EP0539382B1 EP91909786A EP91909786A EP0539382B1 EP 0539382 B1 EP0539382 B1 EP 0539382B1 EP 91909786 A EP91909786 A EP 91909786A EP 91909786 A EP91909786 A EP 91909786A EP 0539382 B1 EP0539382 B1 EP 0539382B1
Authority
EP
European Patent Office
Prior art keywords
locking
machine according
handle
coupling
casing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP91909786A
Other languages
German (de)
French (fr)
Other versions
EP0539382A1 (en
Inventor
Dieter Schaefer
Erich Borst
Anton Reiter
Willi Sproesser
Manfred-Wilhelm Staebler
Fritz Kuettner
Bernhard Eicher
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP0539382A1 publication Critical patent/EP0539382A1/en
Application granted granted Critical
Publication of EP0539382B1 publication Critical patent/EP0539382B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B23/00—Portable grinding machines, e.g. hand-guided; Accessories therefor
    • B24B23/02—Portable grinding machines, e.g. hand-guided; Accessories therefor with rotating grinding tools; Accessories therefor
    • B24B23/028—Angle tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25F—COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR
    • B25F5/00—Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
    • B25F5/02—Construction of casings, bodies or handles

Definitions

  • the invention is based on an electric hand tool, in particular an angle grinder, of the type defined in the preamble of claim 1.
  • Hand tools in particular angle grinders, of the type mentioned at the beginning are exclusively equipped with an on and off switch which is actuated via the switch strip.
  • the switch strip is located on the underside of the handle and is actuated by at least one finger when the handle is grasped and kept actuated while working with the machine.
  • the ergonomic design of the handle such as cross-sectional shape and angle of inclination to the device axis, is optimized for a single working position of the machine.
  • the same applies to the arrangement of the switch strip which is often equipped with a switch-on lock and switch-on lock, which can be operated quickly and safely in this working position.
  • a hand tool is known from EP 0 267 472, the handle of which, together with the switch strip, can be rotated about its longitudinal axis with respect to the motor housing. A lock for the handle is not provided. This solution is therefore unsuitable for hand-held power tools in which a torque is to be transmitted to the tool or the hand of the operator via the handle.
  • An angle grinder for example, is used in addition to grinding or scrubbing for cutting work, such as cutting stone slabs.
  • the optimum working position mentioned above is usually given for the scrubbing working position, in which the grinding wheel points downwards, that is to say is approximately parallel to the switch strip.
  • the angle grinder is rotated 90 o around its longitudinal axis to the left or right so that the cutting disc is approximately perpendicular to the workpiece. This rotation puts the handle and the switch bar in an unfavorable position for the comprehensive hand. If the machine is turned to the left and the handle is gripped with the right hand, the switch bar comes to rest in the ball of the hand.
  • the switch bar can only be held and operated with the thumb. In both cases, the switch strip cannot be held securely and without fatigue. In addition, in the event of danger, the position of the switch-on lock and switch-on interlock cannot be reacted to and switched off quickly enough.
  • the gear head with a tool holder for the grinding and cutting disc is detachably arranged on the motor housing in a known angle grinding machine. After loosening four fastening screws and removing them from the holes, the gear head on the motor housing centering can be turned 90 o to the right or left. After that they are Reinstall the screws and screw the gear head onto the motor housing.
  • the disassembly and reassembly of the gear head on the motor housing is relatively complex, so that this known angle grinder is not suitable for applications in which adjustments often have to be made.
  • the electric hand machine tool according to the invention in particular an angle grinder, with the features of claim 1 has the advantage of simple and quick handling.
  • the handle or gear head on the motor housing can be turned until the tool holder and switch strip are assigned to the new working position of the machine.
  • the locking device is activated again and the clamping device is actuated.
  • Locking and clamping devices ensure optimal safety for the operator, since on the one hand a relative rotation of the handle or gear head to the motor housing is reliably excluded and on the other hand there is a fixed connection between the parts that can move with respect to one another. Both devices are structurally simple and space-saving to implement and insensitive to dirt and dust.
  • the clamping device is particularly expedient realized in that the handle or gear head has a shell-like housing which engages with a radially projecting collar in a circumferential groove on the motor housing and has a longitudinal slot in the collar area, and in that the clamping device has a clamping screw extending transversely to the longitudinal slot, which by means of a clamping lever in a thread can be screwed so that the housing areas formed on both sides of the slot can be moved towards one another while reducing the width of the longitudinal slot.
  • the collar is clamped radially in the circumferential groove of the motor housing.
  • Providing a tooth coupling between the clamping screw and the clamping lever in the locking device according to a further embodiment of the invention which can be released by axial displacement of a coupling part, makes it possible to readjust the clamping force of the clamping screw and ensures that the clamping lever always assumes a precisely defined end position in its clamping position.
  • the locking device is expediently realized in that in the motor housing a number of locking grooves corresponding to the number of required working positions of the machine are provided, which are offset by corresponding angles of rotation, and in that a locking cam is pivotally arranged in the shell housing, which is form-fitting can intervene in one of the locking grooves.
  • an inevitable coupling of the locking and clamping device is achieved in that the locking cam sits in a rotationally fixed manner on a coupling sleeve which coaxially surrounds the clamping screw and which, in turn, also one of the coupling parts of the tooth coupling is operatively connected via a claw coupling.
  • a contact element of an interrupter contact is arranged in the locking grooves on the one hand and on the locking cam of the locking device on the other hand, which contact element is located in the electrical connecting line between the on / off switch actuated by the switch strip and the electric drive motor and is designed in such a way that that it is only closed when the locking cam engages in the locking groove. This ensures that the circuit to the electric drive motor is interrupted when the handle or gear head is adjusted and is only restored after proper locking and tensioning.
  • the side view of the electrical angle grinder shown in FIG. 1 as an exemplary embodiment of a general electric hand-held power tool has a motor housing 10 which accommodates an electric drive motor (not shown), a gear head 11 on one end of the housing and a handle 12 on the other end of the housing.
  • a tool holder 13 can be seen, in which here a grinding wheel 14 is held, which is used in the extended position for scrubbing and in a broken line position rotated by 90 ° for separation.
  • the handle 12 consists of a handle 15, which is enclosed by the hand when working with the angle grinder, and of a bracket 16 attached to it in one piece, which covers the handle 15 on the underside while leaving a through opening 17 and when working with the angle grinder around the handle handle 15 placed down protective covers.
  • a switch strip 18 projects into the passage opening 17, which actuates an on and off switch for the electric drive motor.
  • the gear head 11 is fixed to the motor housing 10, preferably in one piece, while the handle 12 is rotated relative to the motor housing 10 and can be fixed in certain rotational positions on the motor housing 10 by means of a locking and clamping device, both of which are actuated by a tensioning lever 19 .
  • the handle 12 has a shell-like housing, hereinafter referred to as the shell housing 20, which engages with a radially projecting collar 21 in a circumferential groove 22 on the motor housing 10 for the rotatable mounting of the handle 12 on the motor housing 10.
  • the shell housing 20 has a longitudinal slot 23 (FIG. 3), which enables the collar 21 to be clamped radially at the base of the circumferential groove 22 by means of the clamping device 24.
  • the shell housing 20 is made of two half-shells which are held together by three screw connections 25.
  • the two half-shells 201 and 202 and one of the screw connections 25 can be seen in FIG. 3.
  • the longitudinal slot 23 is on the top of the Shell housing 20 is formed at the joint of the two half-shells 201, 202.
  • the clamping device 24 consists of a clamping screw 26 which extends directly below the longitudinal slot 23 transversely to the housing axis and passes through a bore 27 in one half-shell 201 and can be screwed into a threaded hole 28 provided in the other half-shell 202.
  • the tensioning screw 26 is actuated by the tensioning lever 19, as will be explained in more detail below.
  • the tensioning lever 19 At the end of the clamping screw 26 facing away from the threaded hole 28, the latter is firmly connected to a first coupling part 31 of a tooth coupling 30, which is supported via a coupling sleeve 29 against a wall region surrounding the bore 27, which is formed by an external depression 33 in the half-shell 201 .
  • the first coupling part 31 carries, on a section tapered in diameter, a ring gear with radially projecting coupling teeth 34, into which similar coupling teeth 34 of a ring gear engage on the second coupling part 32, which coaxially encompasses the first coupling part 31.
  • the second coupling part 32 is formed in one piece with the tensioning lever 19, which projects at a right angle from the second coupling part 32 and extends laterally on the shell housing 20.
  • a bolt 35 is screwed in at the end, which carries a collar 36.
  • a compression spring 38 is supported between the collar 36 and an annular web 37 in the interior of the hollow cylindrical coupling part 32.
  • the block length of the compression spring 38 and the axial length of the clutch teeth 34 are coordinated so that the second clutch part 32 can be axially displaced by pulling the tensioning lever 19 away from the shell housing 20 to such an extent that the clutch teeth 34 are disengaged from the first and second clutch parts 31, 32 are.
  • the locking device 40 allows the determination of the handle 12 in three different rotational positions of the motor housing 10, in a in Fig. 1 - basic position shown 3 and in two 90 o offset rotational positions by rotating the handle 12 about the housing longitudinal axis from the starting position can be adjusted to the left or right.
  • the motor housing 10 carries three housing pegs 41-43 which are offset by 90 ° from one another and which project radially into the interior and each carry a locking groove 44-46.
  • An arcuate web 52 connects the three locking pins 41-43 to each other, each of which is attached to the free end of the housing pins 41-43 and is integral with them.
  • a locking cam 47 interacts with the locking grooves 44 - 46 and can be pivoted into the locking grooves 44 - 46 in a form-fitting manner in order to fix the handle 12 on the motor housing 10.
  • the bolt-shaped locking cam 47 is seated in a rotationally fixed manner on the coupling sleeve 29, which is part of the locking device 40.
  • the coupling sleeve 29 is rotatably seated on the clamping screw 26 of the clamping device 24 and carries on an annular web 39 comprising the first coupling part 31 of the tooth coupling 30, claws 48 of a claw coupling 50, which interact with corresponding claws 48 on the end face of the second coupling part 32 of the tooth coupling 30.
  • the claws 48 on the coupling sleeve 29 and on the second coupling part 32 are designed such that when the second coupling part 32 is axially displaced in order to release the tooth coupling 30, the claws 48 remain in engagement with one another, so that the claw coupling 50 is not released in the process.
  • the handle 12 is to be turned so that the locking cam 47 is aligned with one of the locking grooves 44-46. Then the clamping lever 19 from the in Fig. 2nd dashed line position, in which rises above the handle 12, to pivot downward in the direction of arrow 49. During this pivoting movement, on the one hand, the coupling sleeve 29 is rotated via the claw coupling 50, as a result of which the locking cam 47 pivots into the corresponding locking groove 44 - 46.
  • the clamping screw 26 is rotated via the tooth coupling 30, which screwed deeper into the threaded hole 28 and thereby moves the two half-shells 201 and 202 of the shell housing 20 towards one another while reducing the width of the longitudinal slot 23.
  • the collar 21 of the shell housing 20 is pressed radially against the base of the circumferential groove 22 in the motor housing 10 and the handle 12 is clamped on the motor housing 10.
  • the tensioning lever 19 strikes against a stop 51 arranged on the outside of the shell housing 20. In this end position of the clamping lever 19, the locking cam 47 is pivoted fully into the corresponding locking groove 44-46.
  • the tensioning lever 19 is to be pulled axially away from the shell housing 20 until a stop is given by compressing the compression spring 38 to its block length. In this position, the teeth 34 of the tooth coupling 30 are disengaged and the clamping lever 19 is separated from the clamping screw 26. Since the dog clutch 50 remains closed, the connection between the locking cam 47 and the clamping lever 19 is maintained. The clamping lever 19 decoupled from the clamping screw 26 is now pivoted back somewhat in the direction of arrow 49 away from the stop 51 and released again.
  • the tensioned compression spring 38 engages the coupling parts 31 and 32 of the tooth coupling 30 again, and the tensioning lever 19 and the tensioning screw 26 are again connected to one another in a rotationally fixed manner.
  • the tension lever 19 is again pivoted in the direction of arrow 49 up to the stop 51 and the toothed screw 26 is screwed further into the threaded hole 28.
  • the clamping device 124 and locking device 140 are designed separately from one another and must be operated separately.
  • the handling is a bit more cumbersome, but the design is cheaper in terms of manufacturing costs.
  • the clamping device 124 is unchanged and corresponds to the clamping device 24 in FIG. 3.
  • the coupling sleeve surrounding the clamping screw 26, which is part of the locking device 40 in FIG. 3, has been omitted, so that the first coupling part 31 of the tooth coupling 30 is supported directly on the wall section of the depression 33 in the shell housing 20.
  • Corresponding components are therefore designated in FIG. 5 with the same reference symbols as in FIG. 3.
  • the locking device 140 is arranged diametrically to the clamping device 124 at the front transition of the bracket 16 into the handle handle 15 of the handle 12.
  • a locking lever 57 with a bearing pin 58 is pivotably mounted in a bearing sleeve 56 which is arranged in one piece on the half-shell 201.
  • One lever arm of the locking lever 57 is designed as an actuation button 59, while the other lever arm forms the locking cam 147.
  • the locking lever 57 is arranged in a recess 61 in the bracket 16 and is loaded by a spiral spring 60 such that the actuating button 59 protrudes from the recess 61 on the bracket 16 (Fig. 6).
  • the locking cam 147 engages in one of three locking grooves 144-146, which are arranged on the outside of the motor housing 10.
  • the locking grooves 144 - 146 are in turn offset by 90 o , so that the handle 12 can be rotated in the same way and locked and clamped in the same rotational positions.
  • the locking cam 147 automatically falls into the respective locking groove 144-146 due to the action of the spiral spring 60, so that only the tension lever 19 has to be actuated in the manner described. Two different levers only have to be actuated to release the clamping device 24 and the locking device 140.
  • the bracket 216 of the handle 12 also functions as a clamping lever for the synchronous actuation of the clamping device 224 and the locking device 240.
  • the bracket 216 is rotatably held at one end on two bearing journals 62, 63 , which protrude inwards on a half-shell 201 and 202 of the shell housing 20 and are aligned with one another.
  • the other end of the bracket 216 is releasably attached to the handle handle 15 by means of a snap lock 64 (FIG. 7).
  • the clamping device 224 (FIG. 8) in turn comprises the clamping screw 26 which on the one hand passes through the bore 27 in the half-shell 201 and on the other hand can be screwed into the threaded hole 28 in the other half-shell 202.
  • the bore 27 is made coaxially in one bearing pin 62 and the threaded hole 28 in the other bearing pin 63.
  • a coupling sleeve 229 which is rotatably connected to the bracket 216, is in turn rotatably seated on the clamping screw 26.
  • the coupling sleeve 229 is operatively connected to a decoupling member 65 via a tooth coupling 230 arranged on the end face.
  • the hollow cylindrical coupling member 65 carries a mushroom grip 66 in one piece at the free end and encloses a screw head-like section 67 of the clamping screw 26.
  • a bolt 35 is screwed on the end face, which carries a collar 36.
  • the compression spring 38 is supported between the collar 36 and an annular web 37 in the interior of the decoupling member 65.
  • the axial length of the coupling teeth of the tooth coupling 230 and the block length of the compression spring 38 are in turn coordinated with one another such that by pulling out the decoupling member 65 against the force of the compression spring 38, the coupling teeth of the tooth coupling 230 come out of engagement before the axial displacement of the decoupling member 65 by compressing the Compression spring 38 is blocked to block length.
  • the decoupling member 65 is connected in a rotationally fixed manner to the section 67 of the tensioning screw 26 via a claw coupling 250.
  • the claw coupling 250 is designed so that the non-rotatable connection remains even when the tooth coupling 230 is released.
  • Locking device 240 and clamping device 224 are positively coupled and are actuated simultaneously via the bracket 216.
  • the locking cam 247 (FIG. 7) is formed on the free end of the bracket 216 which projects beyond the pivot point and can be pivoted into three locking grooves 244-246 in the motor housing 10.
  • the locking grooves 244-246 are in turn introduced into housing pins 241-243 of the motor housing 10, which project into the interior of the housing offset by 90 ° to one another and are connected by the arcuate web 52. If the bracket 216 is fixed to the handle handle 15 by the snap lock 64, the locking cam 247 engages positively in one of the three locking grooves 244-246. If, after loosening the snap lock 64, the bracket 216 is pivoted in the direction of arrow 249 into the position shown in dashed lines in FIG. 7, the locking cam 247 is pivoted out of the respective locking groove 244-246.
  • an interrupter contact 69 is arranged between the on / off switch 68 actuated by the switch strip 18 (FIG. 7) for the electric drive motor of the angle grinder and the electric drive motor, and is always closed only when the bracket 216 is in a snap lock 64 snapped onto the handle 15 and thus the locking cam 247 is pivoted into one of the three locking grooves 244-246. If the locking cam 247 is swiveled out of the respective locking groove 244-246, the interrupter contact 69 is automatically opened and any power supply to the electric drive motor is interrupted.
  • each locking groove 244-246 is connected to one another when the locking cam 247 is pivoted in via a contact bridge 70 with two lateral contact surfaces 73 on the locking cam 247.
  • the one contact spring 71 in all three locking grooves 244-246 is connected to a first plug contact 74 and the other three contact springs 72 of the locking grooves 244-246 are connected to a second plug contact 75. While the first plug contact 74 is connected to an output of the two-pole on / off switch 68, a current brush of the electric drive motor is connected to the second plug contact 75.
  • the mode of operation of the positively coupled locking device 240 and clamping device 224 is similar to that described in FIGS. 1-3.
  • the bracket 216 is pivoted after the snap closure 64 has been released in the direction of the arrow 249, the locking cam 247 is pivoted out of the locking groove 244 and at the same time the power supply to the electric drive motor is interrupted.
  • the coupling sleeve 229, the tooth coupling 230, the decoupling member 65 and the Claw coupling 250 unscrewed the clamping screw 26 more from the threaded hole 28 so that the clamping connection between the collar 22 on the shell housing 20 and the circumferential groove 22 in the motor housing 10 is released.
  • the handle 12 can now be pivoted 90 o to the left or right into the new working position.
  • the bracket 216 is then pivoted back and locked in the snap lock 64.
  • the locking cam 247 pivots into the corresponding locking groove 245 or 246, the contact bridge 70 on the locking cam 247 connects the two contact springs 71, 72, and the interrupter contact 69 is closed.
  • the coupling sleeve 229 rotating with the bracket 216, the clamping screw 26 is in turn rotated via tooth coupling 230 and claw coupling 250 and screwed deeper into the threaded hole 28.
  • the two half-shells 201, 202 are thus clamped on the motor housing 10 in the manner described. An adjustment of the clamping force is possible through the uncoupling member 65 with mushroom grip 66.
  • the invention is not limited to the exemplary embodiment described. So the handle can be fixed and the gear head rotatably connected to the motor housing be. The clamping and locking device is then to be arranged between the gear head and the motor housing.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)

Abstract

The invention concerns a hand-held electrical machine tool, in particular an angle grinding machine, in which, to optimize the human-engineering aspects of the design, the handle (12) with its trigger bar (18) can rotate relative to the tool holder (13) on the drive head (11). In order to be able to change the relative position of the handle (12) and tool holder (13) over rapidly without complications occurring, the handle (12) can be locked against rotation in at least two rotational positions by means of a manually operated locking device (40) mounted on the motor casing (10) accommodating the electrical drive, the handle being held by a manually operated tensioning device (24) on the motor housing (10). In a preferred embodiment, the locking device (40) and the tensioning device (24) are positively coupled to each other and are operated simultaneously by a single tensioning lever (19).

Description

Die Erfindung geht aus von einer elektrischen Handwerkzeugmaschine, insbesondere Winkelschleifmaschine, der im Oberbegriff des Anspruchs 1 definierten Gattung.The invention is based on an electric hand tool, in particular an angle grinder, of the type defined in the preamble of claim 1.

Handwerkzeugmaschinen, insbesondere Winkelschleifmaschinen, der eingangs genannten Art sind heute ausschließlich mit einem Ein- und Ausschalter ausgerüstet, der über die Schalterleiste betätigt wird. Die Schalterleiste liegt an der Handgriffunterseite und wird beim Umfassen des Handgriffes von mindestens einem Finger betätigt und während des Arbeitens mit der Maschine betätigt gehalten. Die ergonomische Gestaltung des Handgriffes, wie Querschnittsform und Neigungswinkel zur Geräteachse, ist für eine einzige Arbeitsstellung der Maschine optimiert. Das gleiche gilt auch für die Anordnung der Schalterleiste, die häufig mit Einschaltsperre und Einschaltverriegelung versehen ist, die sich in dieser Arbeitsstellung schnell und sicher bedienen lassen.Hand tools, in particular angle grinders, of the type mentioned at the beginning are exclusively equipped with an on and off switch which is actuated via the switch strip. The switch strip is located on the underside of the handle and is actuated by at least one finger when the handle is grasped and kept actuated while working with the machine. The ergonomic design of the handle, such as cross-sectional shape and angle of inclination to the device axis, is optimized for a single working position of the machine. The same applies to the arrangement of the switch strip, which is often equipped with a switch-on lock and switch-on lock, which can be operated quickly and safely in this working position.

Durch die EP 0 267 472 ist eine Handwerkzeugmaschine bekannt, deren Handgriff gemeinsam mit der Schalterleiste um seine Längsachse gegenüber dem Motorgehäuse verdrehbar ist. Eine Arretierung für den Handgriff ist nicht vorgesehen. Daher ist diese Lösung für Handwerkzeugmaschinen ungeeignet, bei denen über den Handgriff ein Drehmoment auf das Werkzeug bzw. die Hand des Bedienenden übertragen werden soll.A hand tool is known from EP 0 267 472, the handle of which, together with the switch strip, can be rotated about its longitudinal axis with respect to the motor housing. A lock for the handle is not provided. This solution is therefore unsuitable for hand-held power tools in which a torque is to be transmitted to the tool or the hand of the operator via the handle.

Einige Handwerkzeugmaschinen werden in mehr als einer Arbeitsstellung für verschiedene Arbeitsgänge verwendet. Eine Winkelschleifmaschine z.B. wird neben dem Schleifen oder Schrubben auch für Trennarbeiten, z.B. Trennen von Steinplatten, verwendet. Die vorstehend angesprochene optimale Arbeitsstellung ist üblicherweise für die Arbeitsstellung Schrubben gegeben, in welcher die Schleifscheibe nach unten weist, also in etwa parallel zur Schalterleiste liegt. Bei Trennarbeiten hingegen wird die Winkelschleifmaschine um 90o um ihre Längsachse nach links oder rechts gedreht, so daß die Trennscheibe etwa senkrecht zum Werkstück steht. Durch diese Drehung kommt der Handgriff zusammen mit der Schalterleiste in eine ungünstige Lage zur umfassenden Hand. Wird die Maschine nach links gedreht und der Handgriff mit der rechten Hand umfaßt, kommt die Schalterleiste im Handballen zu liegen. Wird die Maschine nach rechts gedreht und mit der rechten Hand gehalten, kann die Schalterleiste nur noch mit dem Daumen gehalten und betätigt werden. In beiden Fällen ist ein sicheres und ermüdungsfreies Halten der Schalterleiste nicht möglich. Außerdem kann in Gefahrenfall im Hinblick auf die Lage von Einschaltsperre und Einschaltverriegelung nicht schnell genug reagiert und abgeschaltet werden.Some hand machine tools are used in more than one working position for different operations. An angle grinder, for example, is used in addition to grinding or scrubbing for cutting work, such as cutting stone slabs. The optimum working position mentioned above is usually given for the scrubbing working position, in which the grinding wheel points downwards, that is to say is approximately parallel to the switch strip. When cutting, however, the angle grinder is rotated 90 o around its longitudinal axis to the left or right so that the cutting disc is approximately perpendicular to the workpiece. This rotation puts the handle and the switch bar in an unfavorable position for the comprehensive hand. If the machine is turned to the left and the handle is gripped with the right hand, the switch bar comes to rest in the ball of the hand. If the machine is turned to the right and held with the right hand, the switch bar can only be held and operated with the thumb. In both cases, the switch strip cannot be held securely and without fatigue. In addition, in the event of danger, the position of the switch-on lock and switch-on interlock cannot be reacted to and switched off quickly enough.

Um die vorstehend beschriebenen Nachteile zu umgehen, ist bei einer bekannten Winkelschleifmaschine der Getriebekopf mit Werkzeugaufnahme für die Schleif- und Trennscheibe lösbar am Motorgehäuse angeordnet. Nach Lösen von vier Befestigungsschrauben und deren Entfernung aus den Bohrungen läßt sich der Getriebekopf auf der Motorgehäusezentrierung um 90o nach rechts oder links drehen. Danach sind die Schrauben wieder einzuführen, und der Getriebekopf ist am Motorgehäuse festzuschrauben. Die Demontage und erneute Montage des Getriebekopfs am Motorgehäuse ist relativ aufwendig, so daß diese bekannte Winkelschleifmaschine nicht für Einsatzfälle geeignet ist, bei denen öfters verstellt werden muß.In order to avoid the disadvantages described above, the gear head with a tool holder for the grinding and cutting disc is detachably arranged on the motor housing in a known angle grinding machine. After loosening four fastening screws and removing them from the holes, the gear head on the motor housing centering can be turned 90 o to the right or left. After that they are Reinstall the screws and screw the gear head onto the motor housing. The disassembly and reassembly of the gear head on the motor housing is relatively complex, so that this known angle grinder is not suitable for applications in which adjustments often have to be made.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße elektrische Handwerkzeugmaschine, insbesondere Winkelschleifmaschine, mit den Merkmalen des Anspruchs 1 hat den Vorteil der einfachen und schnellen Handhabung. Nach manuellem Lösen der Klemm- und Verriegelungsvorrichtung - also ohne Montagewerkzeuge - kann der Handgriff oder Getriebekopf am Motorgehäuse gedreht werden, bis die für die neue Arbeitsstellung der Maschine vorteilhafte Zuordnung von Werkzeugaufnahme und Schalterleiste gegeben ist. Dann wird die Verriegelungsvorrichtung wieder aktiviert und die Klemmvorrichtung betätigt. Verriegelungs- und Klemmvorrichtung sorgen für eine optimale Sicherheit für den Bedienenden, da einerseits eine Relativverdrehung von Handgriff bzw. Getriebekopf zum Motorgehäuse sicher ausgeschlossen und andererseits eine feste Verbindung zwischen den zueinander beweglichen Teilen gegeben ist. Beide Vorrichtungen sind konstruktiv einfach und platzsparend zu realisieren und unempfindlich gegen Schmutz und Staub.The electric hand machine tool according to the invention, in particular an angle grinder, with the features of claim 1 has the advantage of simple and quick handling. After manually loosening the clamping and locking device - i.e. without assembly tools - the handle or gear head on the motor housing can be turned until the tool holder and switch strip are assigned to the new working position of the machine. Then the locking device is activated again and the clamping device is actuated. Locking and clamping devices ensure optimal safety for the operator, since on the one hand a relative rotation of the handle or gear head to the motor housing is reliably excluded and on the other hand there is a fixed connection between the parts that can move with respect to one another. Both devices are structurally simple and space-saving to implement and insensitive to dirt and dust.

Durch die in den weiteren Ansprüchen aufgeführten Maßnahmen sind vorteilhafte Weiterbildungen und Verbesserungen der im Anspruch 1 angegebenen Handwerkzeugmaschine, insbesondere Winkelschleifmaschine, möglich.Advantageous further developments and improvements of the hand-held power tool specified in claim 1, in particular an angle grinder, are possible through the measures listed in the further claims.

Die Klemmvorrichtung wird gemäß einer bevorzugten Ausführungsform der Erfindung besonders zweckmäßig dadurch realisiert, daß der Handgriff oder Getriebekopf ein schalenartiges Gehäuse aufweist, das mit einem radial vorspringenden Bund in eine Umlaufnut am Motorgehäuse eingreift und im Bundbereich einen Längsschlitz aufweist, und daß die Klemmvorrichtung eine quer zum Längsschlitz sich erstreckende Spannschraube hat, die mittels eines Spannhebels in einem Gewinde verschraubbar ist, so daß die beidseitig des Schlitzes ausgebildeten Gehäusebereiche unter Reduzierung der Breite des Längsschlitzes aufeinanderzu bewegt werden können. Dadurch wird der Bund radial in der Umlaufnut des Motorgehäuses verspannt.According to a preferred embodiment of the invention, the clamping device is particularly expedient realized in that the handle or gear head has a shell-like housing which engages with a radially projecting collar in a circumferential groove on the motor housing and has a longitudinal slot in the collar area, and in that the clamping device has a clamping screw extending transversely to the longitudinal slot, which by means of a clamping lever in a thread can be screwed so that the housing areas formed on both sides of the slot can be moved towards one another while reducing the width of the longitudinal slot. As a result, the collar is clamped radially in the circumferential groove of the motor housing.

Durch das Vorsehen einer durch Axialverschiebung eines Kupplungsteils lösbaren Zahnkupplung zwischen Spannschraube und Spannhebel in der Verriegelungsvorrichtung gemäß einer weiteren Ausführungsform der Erfindung ist ein Nachstellen der Klemmkraft der Spannschraube möglich und sichergestellt, daß der Spannhebel in seiner Klemmstellung immer eine exakt definierte Endlage einnimmt.Providing a tooth coupling between the clamping screw and the clamping lever in the locking device according to a further embodiment of the invention, which can be released by axial displacement of a coupling part, makes it possible to readjust the clamping force of the clamping screw and ensures that the clamping lever always assumes a precisely defined end position in its clamping position.

Gemäß einer bevorzugten Ausführungsform der Erfindung wird die Verriegelungsvorrichtung zweckmäßig dadurch realisiert, daß im Motorgehäuse eine der Anzahl der erforderlichen Arbeitsstellungen der Maschine entsprechende Zahl von Verriegelungsnuten vorgesehen sind, die um entsprechende Drehwinkel versetzt sind, und daß im Schalengehäuse ein Verriegelungsnocken schwenkbar angeordnet ist, der formschlüssig in jeweils eine der Verriegelungsnuten einzugreifen vermag.According to a preferred embodiment of the invention, the locking device is expediently realized in that in the motor housing a number of locking grooves corresponding to the number of required working positions of the machine are provided, which are offset by corresponding angles of rotation, and in that a locking cam is pivotally arranged in the shell housing, which is form-fitting can intervene in one of the locking grooves.

Eine zwangsläufige Kopplung von Verriegelungs- und Klemmvorrichtung wird gemäß einer bevorzugten Ausführungsform der Erfindung dadurch erreicht, daß der Verriegelungsnocken auf einer die Spannschraube koaxial umgebenden Kupplungshülse drehfest sitzt, die ihrerseits mit einem der Kupplungsteile der Zahnkupplung über eine Klauenkupplung in Wirkverbindung steht. Diese Zusammenfassung von Klemm- und Verriegelungsvorrichtung zu einer einzigen Baueinheit hat den Vorteil, daß nur ein einziger Betätigungshebel vorhanden ist und damit - abgesehen von der einfacheren Handhabung - sichergestellt ist, daß mit der Verriegelung immer eine Verspannung und umgekehrt einhergeht. Anders als bei getrennter Ausführung von Verriegelungs- und Klemmvorrichtung muß nicht nach jedem Umstellen gesondert geprüft werden, ob beide Vorrichtungen aktiviert sind.According to a preferred embodiment of the invention, an inevitable coupling of the locking and clamping device is achieved in that the locking cam sits in a rotationally fixed manner on a coupling sleeve which coaxially surrounds the clamping screw and which, in turn, also one of the coupling parts of the tooth coupling is operatively connected via a claw coupling. This combination of clamping and locking device into a single unit has the advantage that there is only a single actuating lever and thus - apart from the simpler handling - it is ensured that there is always tension and vice versa with the locking. In contrast to the separate version of the locking and clamping device, it is not necessary to check separately after each changeover whether both devices are activated.

In einer weiteren Ausführungsform der Erfindung ist in den Verriegelungsnuten einerseits und an dem Verriegelungsnocken der Verriegelungsvorrichtung andererseits jeweils ein Kontaktelement eines Unterbrecherkontaktes angeordnet, der in der elektrischen Verbindungsleitung zwischen dem von der Schalterleiste betätigten Ein- und Ausschalter und dem elektrischen Antriebsmotor liegt und so ausgebildet ist, daß er nur bei in die Verriegelungsnut eingreifendem Verriegelungsnocken geschlossen ist. Damit ist gewährleistet, daß bei der Verstellung von Handgriff oder Getriebekopf der Stromkreis zum elektrischen Antriebsmotor unterbrochen ist und erst wieder nach ordnungsgemäßer Verriegelung und Verspannung hergestellt wird.In a further embodiment of the invention, a contact element of an interrupter contact is arranged in the locking grooves on the one hand and on the locking cam of the locking device on the other hand, which contact element is located in the electrical connecting line between the on / off switch actuated by the switch strip and the electric drive motor and is designed in such a way that that it is only closed when the locking cam engages in the locking groove. This ensures that the circuit to the electric drive motor is interrupted when the handle or gear head is adjusted and is only restored after proper locking and tensioning.

Zeichnungdrawing

Die Erfindung ist anhand von in der Zeichnung dargestellten Ausführungsbeispielen in der nachfolgenden Beschreibung näher erläutert. Es zeigen:

Fig. 1
eine Seitenansicht einer elektrischen Winkelschleifmaschine,
Fig. 2
eine Seitenansicht des Handgriffes in Verbindung mit einem Motorgehäuseabschnitt der Winkelschleifmaschine in Fig. 1, teilweise geschnitten,
Fig. 3
einen Schnitt längs der Linie III-III in Fig. 2,
Fig. 4
ausschnittweise eine Draufsicht des Handgriffs in Fig. 2,
Fig. 5
eine gleiche Darstellung wie in Fig. 3 einer Winkelschleifmaschine gemäß einem weiteren Ausführungsbeispiel,
Fig. 6
ausschnittweise einen Längsschnitt gemäß Linie VI-VI in Fig. 5,
Fig. 7
eine Seitenansicht eines Handgriffs und eines Gehäuseabschnitts einer Winkelschleifmaschine gemäß einem dritten Ausführungsbeispiel, teilweise geschnitten,
Fig. 8
einen Schnitt längs der Linie VIII-VIII in Fig. 7.
The invention is explained in more detail in the following description with reference to exemplary embodiments shown in the drawing. Show it:
Fig. 1
a side view of an electric angle grinder,
Fig. 2
3 shows a side view of the handle in connection with a motor housing section of the angle grinder in FIG. 1, partly in section,
Fig. 3
2 shows a section along the line III-III in FIG. 2,
Fig. 4
Detail of a plan view of the handle in Fig. 2,
Fig. 5
3 shows an angle grinder according to a further exemplary embodiment,
Fig. 6
sections of a longitudinal section along line VI-VI in Fig. 5,
Fig. 7
2 shows a side view of a handle and a housing section of an angle grinder according to a third exemplary embodiment, partly in section,
Fig. 8
a section along the line VIII-VIII in Fig. 7th

Beschreibung der AusführungsbeispieleDescription of the embodiments

Die in Fig. 1 in Seitenansicht zu sehende elektrische Winkelschleifmaschine als Ausführungsbeispiel für eine allgemeine elektrische Handwerkzeugmaschine, weist ein einen nicht dargestellten elektrischen Antriebsmotor aufnehmendes Motorgehäuse 10 auf, an dessen einer Gehäusestirnseite ein Getriebekopf 11 vorstent und an dessen anderer Gehäusestirnseite sich ein Handgriff 12 fortsetzt. Am Ende Getriebekopfes 11 ist eine Werkzeugaufnahme 13 zu sehen, in welcher hier eine Schleifscheibe 14 gehalten ist, die in der ausgezogen dargestellten Position zum Schrubben und in einer strichliniert dargestellten, um 90o gedrehten Position zum Trennen verwendet wird. Der Handgriff 12 besteht aus einem Stielgriff 15, der beim Arbeiten mit der Winkelschleifmaschine von der Hand umschlossen wird, und aus einem daran einstückig angesetzten Bügel 16, der auf der Unterseite den Stielgriff 15 unter Belassung einer Durchgrifföffnung 17 überzieht und beim Arbeiten mit der Winkelschleifmaschine die um den Stielgriff 15 gelegten Finger nach unten schützend abdeckt. An der dem Bügel 16 zugekehrten Unterseite des Stielgriffs 15 ragt eine Schalterleiste 18 in die Durchgrifföffnung 17 hinein, die einen Ein- und Ausschalter für den elektrischen Antriebsmotor betätigt. Der Getriebekopf 11 ist fest mit dem Motorgehäuse 10, vorzugsweise einstückig, verbunden, während der Handgriff 12 relativ zum Motorgehäuse 10 gedreht und mittels einer Verriegelungs- und Klemmvorrichtung, die beide mit einem Spannhebel 19 betätigt werden, in bestimmten Drehstellungen am Motorgehäuse 10 festgelegt werden kann.The side view of the electrical angle grinder shown in FIG. 1 as an exemplary embodiment of a general electric hand-held power tool has a motor housing 10 which accommodates an electric drive motor (not shown), a gear head 11 on one end of the housing and a handle 12 on the other end of the housing. At the end of the gear head 11, a tool holder 13 can be seen, in which here a grinding wheel 14 is held, which is used in the extended position for scrubbing and in a broken line position rotated by 90 ° for separation. The handle 12 consists of a handle 15, which is enclosed by the hand when working with the angle grinder, and of a bracket 16 attached to it in one piece, which covers the handle 15 on the underside while leaving a through opening 17 and when working with the angle grinder around the handle handle 15 placed down protective covers. On the underside of the handle 15 facing the bracket 16, a switch strip 18 projects into the passage opening 17, which actuates an on and off switch for the electric drive motor. The gear head 11 is fixed to the motor housing 10, preferably in one piece, while the handle 12 is rotated relative to the motor housing 10 and can be fixed in certain rotational positions on the motor housing 10 by means of a locking and clamping device, both of which are actuated by a tensioning lever 19 .

Wie insbesondere in Fig. 2 zu sehen ist, weist dem Handgriff 12 ein schalenartiges Gehäuse auf, im folgenden Schalengehäuse 20 genannt, das zur drehbeweglichen Halterung des Handgriffs 12 am Motorgehäuse 10 mit einem radial vorspringenden Bund 21 in eine Umlaufnut 22 am Motorgehäuse 10 eingreift. Im Bundbereich 21 weist das Schalengehäuse 20 einen Längsschlitz 23 (Fig. 3) auf, der ein radiales Festklemmen des Bundes 21 am Grunde der Umlaufnut 22 mittels der Klemmvorrichtung 24 ermöglicht. Aus fertigungstechnischen Gründen ist das Schalengehäuse 20 aus zwei Halbschalen hergestellt, die durch drei Schraubverbindungen 25 zusammengehalten sind. In Fig. 3 sind die beiden Halbschalen 201 und 202 und eine der Schraubverbindungen 25 zu sehen. Der Längsschlitz 23 ist dabei an der vom Bügel 16 abgekehrten Oberseite des Schalengehäuses 20 an der Stoßstelle der beiden Halbschalen 201,202 ausgebildet.As can be seen in particular in FIG. 2, the handle 12 has a shell-like housing, hereinafter referred to as the shell housing 20, which engages with a radially projecting collar 21 in a circumferential groove 22 on the motor housing 10 for the rotatable mounting of the handle 12 on the motor housing 10. In the collar region 21, the shell housing 20 has a longitudinal slot 23 (FIG. 3), which enables the collar 21 to be clamped radially at the base of the circumferential groove 22 by means of the clamping device 24. For technical reasons, the shell housing 20 is made of two half-shells which are held together by three screw connections 25. The two half-shells 201 and 202 and one of the screw connections 25 can be seen in FIG. 3. The longitudinal slot 23 is on the top of the Shell housing 20 is formed at the joint of the two half-shells 201, 202.

Die Klemmvorrichtung 24 besteht aus einer Spannschraube 26, die sich unmittelbar unterhalb des Längsschlitzes 23 quer zur Gehäuseachse erstreckt und durch eine Bohrung 27 in der einen Halbschale 201 hindurchtritt und in einem in der anderen Halbschale 202 vorgesehenen Gewindeloch 28 verschraubbar ist. Die Betätigung der Spannschraube 26 erfolgt durch den Spannhebel 19, wie im einzelnen noch nachfolgend dargelegt wird. An dem vom Gewindeloch 28 abgekehrten Ende der Spannschraube 26 ist diese fest mit einem ersten Kupplungsteil 31 einer Zahnkupplung 30 verbunden, der sich über eine Kupplungshülse 29 an einen die Bohrung 27 umgebenden Wandbereich abstützt, der durch eine äußere Einsenkung 33 in der Halbschale 201 gebildet ist. Der erste Kupplungsteil 31 trägt an einem im Durchmesser verjüngten Abschnitt einen Zahnkranz mit radial vorspringenden Kupplungszähnen 34, in die gleichartige Kupplungszähne 34 eines Zahnkranzes am zweiten, das erste Kupplungsteil 31 koaxial umgreifenden Kupplungsteil 32 eingreifen. Das zweite Kupplungsteil 32 ist einstückig mit dem Spannhebel 19 ausgebildet, der rechtwinklig von dem zweiten Kupplungsteil 32 absteht und sich seitlich am Schalengehäuse 20 erstreckt. In dem ersten Kupplungsteil 31 ist ein Bolzen 35 stirnseitig eingeschraubt, der einen Bund 36 trägt. Zwischen dem Bund 36 und einem Ringsteg 37 im Innern des hohlzylindrischen Kupplungsteils 32 stützt sich eine Druckfeder 38 ab. Die Blocklänge der Druckfeder 38 und die Axiallänge der Kupplungszähne 34 sind so aufeinander abgestimmt, daß durch Herausziehen des Spannhebels 19 weg vom Schalengehäuse 20 das zweite Kupplungsteil 32 soweit axial verschoben werden kann, daß die Kupplungszähne 34 vom ersten und zweiten Kupplungsteil 31,32 außer Eingriff sind.The clamping device 24 consists of a clamping screw 26 which extends directly below the longitudinal slot 23 transversely to the housing axis and passes through a bore 27 in one half-shell 201 and can be screwed into a threaded hole 28 provided in the other half-shell 202. The tensioning screw 26 is actuated by the tensioning lever 19, as will be explained in more detail below. At the end of the clamping screw 26 facing away from the threaded hole 28, the latter is firmly connected to a first coupling part 31 of a tooth coupling 30, which is supported via a coupling sleeve 29 against a wall region surrounding the bore 27, which is formed by an external depression 33 in the half-shell 201 . The first coupling part 31 carries, on a section tapered in diameter, a ring gear with radially projecting coupling teeth 34, into which similar coupling teeth 34 of a ring gear engage on the second coupling part 32, which coaxially encompasses the first coupling part 31. The second coupling part 32 is formed in one piece with the tensioning lever 19, which projects at a right angle from the second coupling part 32 and extends laterally on the shell housing 20. In the first coupling part 31, a bolt 35 is screwed in at the end, which carries a collar 36. A compression spring 38 is supported between the collar 36 and an annular web 37 in the interior of the hollow cylindrical coupling part 32. The block length of the compression spring 38 and the axial length of the clutch teeth 34 are coordinated so that the second clutch part 32 can be axially displaced by pulling the tensioning lever 19 away from the shell housing 20 to such an extent that the clutch teeth 34 are disengaged from the first and second clutch parts 31, 32 are.

Die Verriegelungsvorrichtung 40 ermöglicht die Festlegung des Handgriffs 12 in drei verschiedenen Drehstellungen am Motorgehäuse 10, und zwar in einer in Fig. 1 - 3 gezeigten Grundstellung und in zwei um 90o versetzten Drehstellungen, die durch Drehen des Handgriffs 12 um die Gehäuselängsachse aus der Grundstellung nach links oder rechts einstellbar sind. Hierzu trägt das Motorgehäuse 10 drei um 90o gegeneinander versetzte Gehäusezapfen 41 - 43, die radial ins Innere vorspringen und jeweils eine Verriegelungsnut 44 - 46 tragen. Ein kreisbogenförmiger Steg 52 verbindet die drei Verriegelungszapfen 41 - 43 miteinander, wobei er jeweils am freien Ende der Gehäusezapfen 41 - 43 ansetzt und mit diesen einstückig ist. Mit den Verriegelungsnuten 44 - 46 wirkt ein Verriegelungsnocken 47 zusammen, der zur Festlegung des Handgriffs 12 am Motorgehäuse 10 formschlüssig in die Verriegelungsnuten 44 - 46 eingeschwenkt werden kann. Der riegelförmige Verriegelungsnocken 47, dessen Form aus Fig. 2 zu erkennen ist, sitzt drehfest auf der Kupplungshülse 29, die Bestandteil der Verriegelungsvorrichtung 40 ist. Die Kupplungshülse 29 sitzt drehbar auf der Spannschraube 26 der Klemmvorrichtung 24 und trägt auf einem das erste Kupplungsteil 31 der Zahnkupplung 30 umfassenden Ringsteg 39, Klauen 48 einer Klauenkupplung 50, die mit entsprechenden Klauen 48 an der Stirnseite des zweiten Kupplungsteils 32 der Zahnkupplung 30 zusammenwirken. Die Klauen 48 an der Kupplungshülse 29 und an dem zweiten Kupplungsteil 32 sind so ausgebildet, daß bei Axialverschiebung des zweiten Kupplungsteils 32 zwecks Lösen der Zahnkupplung 30 die Klauen 48 miteinander in Eingriff bleiben, die Klauenkupplung 50 also dabei nicht gelöst wird.The locking device 40 allows the determination of the handle 12 in three different rotational positions of the motor housing 10, in a in Fig. 1 - basic position shown 3 and in two 90 o offset rotational positions by rotating the handle 12 about the housing longitudinal axis from the starting position can be adjusted to the left or right. For this purpose, the motor housing 10 carries three housing pegs 41-43 which are offset by 90 ° from one another and which project radially into the interior and each carry a locking groove 44-46. An arcuate web 52 connects the three locking pins 41-43 to each other, each of which is attached to the free end of the housing pins 41-43 and is integral with them. A locking cam 47 interacts with the locking grooves 44 - 46 and can be pivoted into the locking grooves 44 - 46 in a form-fitting manner in order to fix the handle 12 on the motor housing 10. The bolt-shaped locking cam 47, the shape of which can be seen in FIG. 2, is seated in a rotationally fixed manner on the coupling sleeve 29, which is part of the locking device 40. The coupling sleeve 29 is rotatably seated on the clamping screw 26 of the clamping device 24 and carries on an annular web 39 comprising the first coupling part 31 of the tooth coupling 30, claws 48 of a claw coupling 50, which interact with corresponding claws 48 on the end face of the second coupling part 32 of the tooth coupling 30. The claws 48 on the coupling sleeve 29 and on the second coupling part 32 are designed such that when the second coupling part 32 is axially displaced in order to release the tooth coupling 30, the claws 48 remain in engagement with one another, so that the claw coupling 50 is not released in the process.

Zum Klemmen und Verriegeln des Handgriffs 12 am Motorgehäuse 10 ist der Handgriff 12 so zu drehen, daß der Verriegelungsnocken 47 mit einer der Verriegelungsnuten 44 - 46 fluchtet. Dann ist der Spannhebel 19 aus der in Fig. 2 strichlinierten Stellung, in welcher der über den Handgriff 12 emporragt, in Pfeilrichtung 49 nach unten zu schwenken. Bei dieser Schwenkbewegung wird zum einen über die Klauenkupplung 50 die Kupplungshülse 29 gedreht, wodurch der Verriegelungsnocken 47 in die entsprechende Verriegelungsnut 44 - 46 einschwenkt. Zum anderen wird über die Zahnkupplung 30 die Spannschraube 26 gedreht, die sich tiefer in das Gewindeloch 28 hineinschraubt und dadurch die beiden Halbschalen 201 und 202 des Schalengehäuses 20 unter Reduzierung der Breite des Längsschlitzes 23 aufeinanderzu bewegt. Durch diese Bewegung der Halbschalen 201,202 im Bereich des Längsschlitzes 23 wird der Bund 21 des Schalengehäuses 20 radial an dem Grund der Umlaufnut 22 im Motorgehäuse 10 angepreßt und der Handgriff 12 am Motorgehäuse 10 geklemmt. Am Ende der Schwenkbewegung schlägt der Spannhebel 19 an einem außen am Schalengehäuse 20 angeordneten Anschlag 51 an. In dieser Endstellung des Spannhebels 19 ist der Verriegelungsnocken 47 voll in die entsprechende Verriegelungsnut 44 - 46 eingeschwenkt.To clamp and lock the handle 12 on the motor housing 10, the handle 12 is to be turned so that the locking cam 47 is aligned with one of the locking grooves 44-46. Then the clamping lever 19 from the in Fig. 2nd dashed line position, in which rises above the handle 12, to pivot downward in the direction of arrow 49. During this pivoting movement, on the one hand, the coupling sleeve 29 is rotated via the claw coupling 50, as a result of which the locking cam 47 pivots into the corresponding locking groove 44 - 46. On the other hand, the clamping screw 26 is rotated via the tooth coupling 30, which screwed deeper into the threaded hole 28 and thereby moves the two half-shells 201 and 202 of the shell housing 20 towards one another while reducing the width of the longitudinal slot 23. As a result of this movement of the half-shells 201, 202 in the region of the longitudinal slot 23, the collar 21 of the shell housing 20 is pressed radially against the base of the circumferential groove 22 in the motor housing 10 and the handle 12 is clamped on the motor housing 10. At the end of the pivoting movement, the tensioning lever 19 strikes against a stop 51 arranged on the outside of the shell housing 20. In this end position of the clamping lever 19, the locking cam 47 is pivoted fully into the corresponding locking groove 44-46.

Zum Nachstellen der Klemmkraft der Spannschraube 26 ist der Spannhebel 19 axial weg vom Schalengehäuse 20 herauszuziehen, bis durch Zusammendrücken der Druckfeder 38 auf ihre Blocklänge ein Anschlag gegeben ist. In dieser Stellung sind die Zähne 34 der Zahnkupplung 30 außer Eingriff, und der Spannhebel 19 ist von der Spannschraube 26 getrennt. Da die Klauenkupplung 50 geschlossen bleibt, bleibt die Verbindung zwischen Verriegelungsnocken 47 und Spannhebel 19 erhalten. Der von der Spannschraube 26 abgekoppelte Spannhebel 19 wird nunmehr in Pfeilrichtung 49 weg vom Anschlag 51 etwas zurückgeschwenkt und wieder losgelassen. Beim Loslassen bringt die gespannte Druckfeder 38 die Kupplungsteile 31 und 32 der Zahnkupplung 30 wieder in Eingriff, und Spannhebel 19 und Spannschraube 26 sind wieder drehfest miteinander verbunden. Der Spannhebel 19 wird wieder in Richtung Pfeil 49 bis an den Anschlag 51 geschwenkt und dabei die Zahnschraube 26 weiter in das Gewindeloch 28 hineingeschraubt.To readjust the clamping force of the tensioning screw 26, the tensioning lever 19 is to be pulled axially away from the shell housing 20 until a stop is given by compressing the compression spring 38 to its block length. In this position, the teeth 34 of the tooth coupling 30 are disengaged and the clamping lever 19 is separated from the clamping screw 26. Since the dog clutch 50 remains closed, the connection between the locking cam 47 and the clamping lever 19 is maintained. The clamping lever 19 decoupled from the clamping screw 26 is now pivoted back somewhat in the direction of arrow 49 away from the stop 51 and released again. When released, the tensioned compression spring 38 engages the coupling parts 31 and 32 of the tooth coupling 30 again, and the tensioning lever 19 and the tensioning screw 26 are again connected to one another in a rotationally fixed manner. The tension lever 19 is again pivoted in the direction of arrow 49 up to the stop 51 and the toothed screw 26 is screwed further into the threaded hole 28.

In der in Fig. 3 gezeigten Relativlage von Handgriff 12 und Motorgehäuse 10, bei welcher der Verriegelungsnocken 47 in die mittlere Verriegelungsnut 44 eingreift, ist eine Arbeitsstellung der Winkelschleifmaschine gegeben, in welcher diese zum Schrubben verwendet wird. Für Trennarbeiten sind mittels des Spannhebels 19 die Klemmvorrichtung 24 und die Verriegelungsvorrichtung 40 zu lösen und der Handgriff um 90o nach rechts oder links zu drehen. Begrenzt wird diese Drehbewegung durch zwei Anschlagnasen 53,54 im Innern des Motorgehäuses 10 und einem Anschlagnocken 55 im Innern des Schalengehäuses 20. Wenn die Anschlagnase 53 oder 54 an dem Anschlagnocken 55 anliegt, fluchtet der Verriegelungsnocken 47 mit der Verriegelungsnut 45 bzw. 46. In dieser Stellung wird dann durch Betätigen des Spannhebels 19 der Handgriff 12 in gleicher Weise wie beschrieben am Motorgehäuse 10 verriegelt und festgeklemmt. In allen übrigen Relativlagen des Handgriffes 12 zum Motorgehäuse 10 wird ein Betätigen des Spannhebels 19 dadurch verhindert, daß der Verriegelungsnocken 47 unmittelbar vor dem bogenförmigen Steg 52 liegt und dadurch nicht geschwenkt werden kann. Der Spannhebel 19 nimmt dabei die mittlere, in Fig. 2 strichliniert dargestellte Lage ein. Wie aus der in Fig. 4 abschnittweise dargestellten Draufsicht des Handgriffs 12 zu erkennen ist, steht in dieser Lage der Spannhebel 19 weit in den Stielgriff 15 vor und behindert hier ein Umschließen des Stielgriffes 15 mit der Hand. Dadurch wird der Benutzer der Winkelschleifmaschine darauf aufmerksam, daß der Handgriff 12 nicht ordnungsgemäß am Motorgehäuse 10 verriegelt und verspannt ist. In der Draufsicht gemäß Fig. 4 ist auch noch einmal deutlich die Klauenkupplung 50 zwischen dem ersten Kupplungsteil 31 der Zahnkupplung 30 und der Kupplungshülse 29 zu sehen.In the relative position of the handle 12 and motor housing 10 shown in FIG. 3, in which the locking cam 47 engages in the central locking groove 44, there is a working position of the angle grinder in which it is used for scrubbing. For separating work, the clamping device 24 and the locking device 40 are to be released by means of the tensioning lever 19 and the handle turned 90 o to the right or left. This rotary movement is limited by two stop lugs 53, 54 in the interior of the motor housing 10 and one stop cam 55 in the interior of the shell housing 20. When the stop lug 53 or 54 abuts the stop cam 55, the locking cam 47 is aligned with the locking groove 45 or 46 this position is then locked and clamped on the motor housing 10 in the same way as described by actuating the clamping lever 19. In all other positions of the handle 12 relative to the motor housing 10, actuation of the tensioning lever 19 is prevented by the fact that the locking cam 47 lies directly in front of the curved web 52 and cannot be pivoted as a result. The tensioning lever 19 assumes the middle position shown in broken lines in FIG. 2. As can be seen from the plan view of the handle 12, which is shown in sections in FIG. 4, in this position the clamping lever 19 protrudes far into the handle handle 15 and prevents the handle handle 15 from being enclosed by hand. As a result, the user of the angle grinder is made aware that the handle 12 is not properly locked and braced on the motor housing 10. In the top view according to FIG. 4, the dog clutch 50 between the first coupling part 31 of the tooth coupling 30 and the one is clearly again Coupling sleeve 29 can be seen.

Bei dem in Fig. 5 und 6 dargestellten Ausführungsbeispiel einer Winkelschleifmaschine sind Klemmvorrichtung 124 und Verriegelungsvorrichtung 140 getrennt voneinander ausgeführt und müssen getrennt bedient werden. Die Handhabung ist dadurch etwas umständlicher, jedoch ist die konstruktive Ausführung hinsichtlich der Herstellungskosten günstiger.In the exemplary embodiment of an angle grinding machine shown in FIGS. 5 and 6, the clamping device 124 and locking device 140 are designed separately from one another and must be operated separately. The handling is a bit more cumbersome, but the design is cheaper in terms of manufacturing costs.

Die Klemmvorrichtung 124 ist unverändert und stimmt mit der Klemmvorrichtung 24 in Fig. 3 überein. Die die Spannschraube 26 umgebende Kupplungshülse, die Bestandteil der Verriegelungsvorrichtung 40 in Fig. 3 ist, ist entfallen, so daß sich das erste Kupplungsteil 31 der Zahnkupplung 30 unmittelbar an dem Wandabschnitt der Einsenkung 33 im Schalengehäuse 20 abstützt. Übereinstimmende Bauteile sind daher in Fig. 5 mit gleichen Bezugszeichen wie in Fig. 3 bezeichnet.The clamping device 124 is unchanged and corresponds to the clamping device 24 in FIG. 3. The coupling sleeve surrounding the clamping screw 26, which is part of the locking device 40 in FIG. 3, has been omitted, so that the first coupling part 31 of the tooth coupling 30 is supported directly on the wall section of the depression 33 in the shell housing 20. Corresponding components are therefore designated in FIG. 5 with the same reference symbols as in FIG. 3.

Die Verriegelungsvorrichtung 140 ist diametral zur Klemmvorrichtung 124 am vorderen Übergang des Bügels 16 in den Stielgriff 15 des Handgriffs 12 angeordnet. In einer an der Halbschale 201 einstückig angeordneten Lagerhülse 56 ist ein Verriegelungshebel 57 mit einem Lagerbolzen 58 schwenkbar gelagert. Der eine Hebelarm des Verriegelungshebels 57 ist als Betätigungstaste 59 ausgebildet, während der andere Hebelarm den Verriegelungsnocken 147 bildet. Der Verriegelungshebel 57 ist in einer Ausnehmung 61 im Bügel 16 angeordnet und wird von einer Biegefeder 60 derart belastet, daß die Betätigungstaste 59 aus der Ausnehmung 61 am Bügel 16 vorsteht (Fig. 6). Dabei greift der Verriegelungsnocken 147 in eine von drei Verriegelungsnuten 144 - 146, die außen am Motorgehäuse 10 angeordnet sind. Die Verriegelungsnuten 144 - 146 sind wiederum um 90o gegeneinander versetzt, so daß der Handgriff 12 in gleicher Weise gedreht und in den gleichen Drehstellungen verriegelt und verspannt werden kann. Bei Erreichen der Schwenkstellung fällt der Verriegelungsnocken 147 infolge der Wirkung der Biegefeder 60 selbsttätig in die jeweilige Verriegelungsnut 144 - 146 ein, so daß nur noch der Spannhebel 19 in der beschriebenen Weise betätigt werden muß. Lediglich zum Lösen der Klemmvorrichtung 24 und der Verriegelungsvorrichtung 140 sind zwei verschiedene Hebel zu betätigen.The locking device 140 is arranged diametrically to the clamping device 124 at the front transition of the bracket 16 into the handle handle 15 of the handle 12. A locking lever 57 with a bearing pin 58 is pivotably mounted in a bearing sleeve 56 which is arranged in one piece on the half-shell 201. One lever arm of the locking lever 57 is designed as an actuation button 59, while the other lever arm forms the locking cam 147. The locking lever 57 is arranged in a recess 61 in the bracket 16 and is loaded by a spiral spring 60 such that the actuating button 59 protrudes from the recess 61 on the bracket 16 (Fig. 6). The locking cam 147 engages in one of three locking grooves 144-146, which are arranged on the outside of the motor housing 10. The locking grooves 144 - 146 are in turn offset by 90 o , so that the handle 12 can be rotated in the same way and locked and clamped in the same rotational positions. When the swivel position is reached, the locking cam 147 automatically falls into the respective locking groove 144-146 due to the action of the spiral spring 60, so that only the tension lever 19 has to be actuated in the manner described. Two different levers only have to be actuated to release the clamping device 24 and the locking device 140.

Bei dem in Fig. 7 und 8 ausschnittweise dargestellten weiteren Ausführungsbeispiel einer Winkelschleifmaschine fungiert der Bügel 216 des Handgriffes 12 zugleich als Spannhebel zur synchronen Betätigung von Klemmvorrichtung 224 und Verriegelungsvorrichtung 240. Hierzu ist der Bügel 216 an einem Ende drehbar auf zwei Lagerzapfen 62,63 gehalten, die jeweils an einer Halbschale 201 bzw. 202 des Schalengehäuses 20 nach innen vorstehen und miteinander fluchten. Das andere Ende des Bügels 216 ist mittels eines Schnappverschlusses 64 an dem Stielgriff 15 lösbar befestigt (Fig. 7).In the further exemplary embodiment of an angle grinder shown in detail in FIGS. 7 and 8, the bracket 216 of the handle 12 also functions as a clamping lever for the synchronous actuation of the clamping device 224 and the locking device 240. For this purpose, the bracket 216 is rotatably held at one end on two bearing journals 62, 63 , which protrude inwards on a half-shell 201 and 202 of the shell housing 20 and are aligned with one another. The other end of the bracket 216 is releasably attached to the handle handle 15 by means of a snap lock 64 (FIG. 7).

Die Klemmvorrichtung 224 (Fig. 8) umfaßt wiederum die Spannschraube 26, die einerseits durch die Bohrung 27 in der Halbschale 201 hindurchgeht und andererseits im Gewindeloch 28 in der anderen Halbschale 202 verschraubbar ist. Dabei ist die Bohrung 27 in dem einen Lagerzapfen 62 und das Gewindeloch 28 in dem anderen Lagerzapfen 63 koaxial eingebracht. Auf der Spannschraube 26 sitzt wiederum drehbar eine Kupplungshülse 229, die drehfest mit dem Bügel 216 verbunden ist. Die Kupplungshülse 229 ist über eine stirnseitig angeordnete Zahnkupplung 230 mit einem Entkupplungsglied 65 in Wirkverbindung. Das hohlzylindrisch ausgebildete Entkupplungsglied 65 trägt am freien Ende einstückig einen Pilzgriff 66 und umschließt einen schraubenkopfartigen Abschnitt 67 der Spannschraube 26.The clamping device 224 (FIG. 8) in turn comprises the clamping screw 26 which on the one hand passes through the bore 27 in the half-shell 201 and on the other hand can be screwed into the threaded hole 28 in the other half-shell 202. The bore 27 is made coaxially in one bearing pin 62 and the threaded hole 28 in the other bearing pin 63. A coupling sleeve 229, which is rotatably connected to the bracket 216, is in turn rotatably seated on the clamping screw 26. The coupling sleeve 229 is operatively connected to a decoupling member 65 via a tooth coupling 230 arranged on the end face. The hollow cylindrical coupling member 65 carries a mushroom grip 66 in one piece at the free end and encloses a screw head-like section 67 of the clamping screw 26.

In diesem Abschnitt 67 ist stirnseitig ein Bolzen 35 eingeschraubt, der einen Bund 36 trägt. Zwischen den Bund 36 und einen Ringsteg 37 im Innern des Entkupplungsglieds 65 stützt sich die Druckfeder 38 ab. Die axiale Länge der Kupplungszähne der Zahnkupplung 230 und die Blocklänge der Druckfeder 38 sind wiederum so aufeinander abgestimmt, daß durch Herausziehen des Entkupplungsgliedes 65 gegen die Kraft der Druckfeder 38 die Kupplungszähne der Zahnkupplung 230 außer Eingriff kommen, bevor die Axialverschiebung des Entkupplungsgliedes 65 durch Zusammenpressen der Druckfeder 38 auf Blocklänge blockiert wird. Das Entkupplungsglied 65 ist über eine Klauenkupplung 250 mit dem Abschnitt 67 der Spannschraube 26 drehfest verbunden. Die Klauenkupplung 250 ist dabei so ausgebildet, daß die drehfeste Verbindung auch bei gelöster Zahnkupplung 230 bestehen bleibt.In this section 67, a bolt 35 is screwed on the end face, which carries a collar 36. The compression spring 38 is supported between the collar 36 and an annular web 37 in the interior of the decoupling member 65. The axial length of the coupling teeth of the tooth coupling 230 and the block length of the compression spring 38 are in turn coordinated with one another such that by pulling out the decoupling member 65 against the force of the compression spring 38, the coupling teeth of the tooth coupling 230 come out of engagement before the axial displacement of the decoupling member 65 by compressing the Compression spring 38 is blocked to block length. The decoupling member 65 is connected in a rotationally fixed manner to the section 67 of the tensioning screw 26 via a claw coupling 250. The claw coupling 250 is designed so that the non-rotatable connection remains even when the tooth coupling 230 is released.

Verriegelungsvorrichtung 240 und Klemmvorrichtung 224 sind zwangsgekoppelt und werden gleichzeitig über den Bügel 216 betätigt. Hierzu ist an dem freien, über den Schwenkpunkt hinausragenden Ende des Bügels 216 der Verriegelungsnocken 247 (Fig. 7) ausgebildet, der in drei Verriegelungsnuten 244 - 246 im Motorgehäuse 10 eingeschwenkt werden kann. Die Verriegelungsnuten 244 - 246 sind wiederum in Gehäusezapfen 241 - 243 des Motorgehäuses 10 eingebracht, die um 90o zueinander versetzt in das Gehäuseinnere vorstehen und durch den kreisbogenförmigen Steg 52 verbunden sind. Ist der Bügel 216 durch den Schnappverschluß 64 am Stielgriff 15 festgelegt, so greift der Verriegelungsnocken 247 formschlüssig in eine der drei Verriegelungsnuten 244 - 246 ein. Ist nach Lösen des Schnappverschlusses 64 der Bügel 216 in Pfeilrichtung 249 in die in Fig. 7 strichliniert gezeigte Stellung geschwenkt, so ist der Verriegelungsnocken 247 aus der jeweiligen Verriegelungsnut 244 - 246 ausgeschwenkt.Locking device 240 and clamping device 224 are positively coupled and are actuated simultaneously via the bracket 216. For this purpose, the locking cam 247 (FIG. 7) is formed on the free end of the bracket 216 which projects beyond the pivot point and can be pivoted into three locking grooves 244-246 in the motor housing 10. The locking grooves 244-246 are in turn introduced into housing pins 241-243 of the motor housing 10, which project into the interior of the housing offset by 90 ° to one another and are connected by the arcuate web 52. If the bracket 216 is fixed to the handle handle 15 by the snap lock 64, the locking cam 247 engages positively in one of the three locking grooves 244-246. If, after loosening the snap lock 64, the bracket 216 is pivoted in the direction of arrow 249 into the position shown in dashed lines in FIG. 7, the locking cam 247 is pivoted out of the respective locking groove 244-246.

Als weitere sicherheitstechnische Maßnahme ist zwischen dem von der Schalterleiste 18 betätigten Ein-/ Ausschalter 68 (Fig. 7) für den elektrischen Antriebsmotor der Winkelschleifmaschine und dem elektrischen Antriebsmotor ein Unterbrecherkontakt 69 angeordnet, der immer nur dann geschlossen ist, wenn der Bügel 216 im Schnappverschluß 64 am Stielgriff 15 eingerastet und damit der Verriegelungsnocken 247 in eine der drei Verriegelungsnuten 244 - 246 eingeschwenkt ist. Ist der Verriegelungsnocken 247 aus der jeweiligen Verriegelungsnut 244 - 246 ausgeschwenkt, so wird automatisch der Unterbrecherkontakt 69 geöffnet und jegliche Stromzufuhr zu dem elektrischen Antriebsmotor unterbrochen. Zur Realisierung dieses Unterbrecherkontakts 69 sind in jeder Verriegelungsnut 244 - 246 zwei Kontaktfedern 71, 72 angeordnet, die bei eingeschwenktem Verriegelungsnocken 247 über eine Kontaktbrücke 70 mit zwei seitlichen Kontaktflächen 73 am Verriegelungsnocken 247 miteinander verbunden werden. Die eine Kontaktfeder 71 in allen drei Verriegelungsnuten 244 - 246 ist mit einem ersten Steckkontakt 74 und die anderen drei Kontaktfedern 72 der Verriegelungsnuten 244 - 246 sind mit einem zweiten Steckkontakt 75 verbunden. Während der erste Steckkontakt 74 mit einem Ausgang des zweipolig ausgebildeten Ein-/Ausschalters 68 verbunden ist, ist an dem zweiten Steckkontakt 75 eine Strombürste des elektrischen Antriebsmotors angeschlossen.As a further safety measure, an interrupter contact 69 is arranged between the on / off switch 68 actuated by the switch strip 18 (FIG. 7) for the electric drive motor of the angle grinder and the electric drive motor, and is always closed only when the bracket 216 is in a snap lock 64 snapped onto the handle 15 and thus the locking cam 247 is pivoted into one of the three locking grooves 244-246. If the locking cam 247 is swiveled out of the respective locking groove 244-246, the interrupter contact 69 is automatically opened and any power supply to the electric drive motor is interrupted. To implement this interrupter contact 69, two contact springs 71, 72 are arranged in each locking groove 244-246, which are connected to one another when the locking cam 247 is pivoted in via a contact bridge 70 with two lateral contact surfaces 73 on the locking cam 247. The one contact spring 71 in all three locking grooves 244-246 is connected to a first plug contact 74 and the other three contact springs 72 of the locking grooves 244-246 are connected to a second plug contact 75. While the first plug contact 74 is connected to an output of the two-pole on / off switch 68, a current brush of the electric drive motor is connected to the second plug contact 75.

Die Wirkungsweise der zwangsgekoppelten Verriegelungsvorrichtung 240 und Klemmvorrichtung 224 ist ähnlich wie zu Fig. 1 - 3 beschrieben. Mit Schwenken des Bügels 216 nach Lösen des Schnappverschlusses 64 in Pfeilrichtung 249 wird der Verriegelungsnocken 247 aus der Verriegelungsnut 244 ausgeschwenkt und gleichzeitig die Stromzufuhr zum elektrischen Antriebsmotor unterbrochen. Mit Schwenken des Bügels 216 wird über die Kupplungshülse 229, die Zahnkupplung 230, das Entkupplungsglied 65 und die Klauenkupplung 250 die Spannschraube 26 mehr aus den Gewindeloch 28 herausgedreht, so daß sich die Klemmverbindung zwischen dem Bund 22 am Schalengehäuse 20 und der Umlaufnut 22 im Motorgehäuse 10 löst. Der Handgriff 12 kann nunmehr um 90o nach links oder rechts in die neue Arbeitsstellung geschwenkt werden. Danach wird der Bügel 216 wieder zurückgeschwenkt und im Schnappverschluß 64 verrastet. Dabei schwenkt der Verriegelungsnocken 247 in die entsprechende Verriegelungsnut 245 oder 246 ein, die Kontaktbrücke 70 am Verriegelungsnocken 247 verbindet die beiden Kontaktfedern 71,72, und der Unterbrecherkontakt 69 ist geschlossen. Durch die mit dem Bügel 216 mitdrehende Kupplungshülse 229 wird wiederum über Zahnkupplung 230 und Klauenkupplung 250 die Spannschraube 26 gedreht und tiefer in das Gewindeloch 28 hineingeschraubt. Damit werden die beiden Halbschalen 201,202 in der beschriebenen Weise am Motorgehäuse 10 festgeklemmt. Ein Nachstellen der Klemmkraft ist durch das Entkupplungsglied 65 mit Pilzgriff 66 möglich. Dieses ist gegen die Kraft der Druckfeder 38 zu ziehen, und zwar weg vom Schalengehäuse 20, bis durch Zusammendrücken der Druckfeder 38 auf Blocklänge ein Anschlag gegeben ist. In dieser Stellung ist die Zahnkupplung 230 gelöst und der Bügel 216 kann ohne Verdrehen der Spannschraube 26 etwa zurückgeschwenkt werden. Mit Loslassen des Pilzgriffes 66 stellt die Druckfeder 38 über die Zahnkupplung 230 die drehfeste Verbindung zwischen dem Bügel 216 und der Spannschraube 26 wieder her. Der Bügel 216 kann wieder in den Schnappverschluß 64 eingeklinkt werden, wobei sich die Spannschraube 26 tiefer in das Gewindeloch 28 hineinschraubt und die Klemmkraft vergrößert ist.The mode of operation of the positively coupled locking device 240 and clamping device 224 is similar to that described in FIGS. 1-3. When the bracket 216 is pivoted after the snap closure 64 has been released in the direction of the arrow 249, the locking cam 247 is pivoted out of the locking groove 244 and at the same time the power supply to the electric drive motor is interrupted. With pivoting of the bracket 216, the coupling sleeve 229, the tooth coupling 230, the decoupling member 65 and the Claw coupling 250 unscrewed the clamping screw 26 more from the threaded hole 28 so that the clamping connection between the collar 22 on the shell housing 20 and the circumferential groove 22 in the motor housing 10 is released. The handle 12 can now be pivoted 90 o to the left or right into the new working position. The bracket 216 is then pivoted back and locked in the snap lock 64. The locking cam 247 pivots into the corresponding locking groove 245 or 246, the contact bridge 70 on the locking cam 247 connects the two contact springs 71, 72, and the interrupter contact 69 is closed. Through the coupling sleeve 229 rotating with the bracket 216, the clamping screw 26 is in turn rotated via tooth coupling 230 and claw coupling 250 and screwed deeper into the threaded hole 28. The two half-shells 201, 202 are thus clamped on the motor housing 10 in the manner described. An adjustment of the clamping force is possible through the uncoupling member 65 with mushroom grip 66. This is to be pulled against the force of the compression spring 38, namely away from the shell housing 20 until a stop is given by compressing the compression spring 38 to block length. In this position, the tooth coupling 230 is released and the bracket 216 can be pivoted back approximately without turning the clamping screw 26. When the mushroom grip 66 is released, the compression spring 38 restores the rotationally fixed connection between the bracket 216 and the clamping screw 26 via the tooth coupling 230. The bracket 216 can be snapped back into the snap lock 64, the clamping screw 26 screwing deeper into the threaded hole 28 and the clamping force being increased.

Die Erfindung ist nicht auf das beschriebene Ausführungsbeispiel beschränkt. So kann der Handgriff fest und der Getriebekopf drehbar mit dem Motorgehäuse verbunden sein. Die Klemm- und Verriegelungsvorrichtung ist dann zwischen Getriebekopf und Motorgehäuse anzuordnen.The invention is not limited to the exemplary embodiment described. So the handle can be fixed and the gear head rotatably connected to the motor housing be. The clamping and locking device is then to be arranged between the gear head and the motor housing.

Claims (21)

  1. Electric hand machine tool, particularly an angle grinding machine, having a motor casing (10) containing an electric drive having a gear head (11), which projects from one end face of the casing and carries a tool mounting, and having a handle (12) extending from the other end face of the casing, arranged in a manner which allows it to be rotated relative to the motor casing and containing an ergonomically situated switch bar (18) for switching on the electric drive, characterised in that the handle (12) or the gear head (11) is locked on the motor casing (10) manually and without auxiliary tools in at least two turned positions, positive connection being made by means of a locking device (40; 140, 240), and frictional connection being made by means of a tightenable clamp device (24; 124; 224), the two being simultaneously operable by means of a tightening lever.
  2. Machine according to Claim 1, characterised in that the handle (12) or the gear head (11) has a shell-like casing (20) which engages by means of a radially projecting collar (21) in a groove (22) extending around the motor casing (10) and, in the collar region, has a longitudinal slot (23), in that the clamp device (24; 124; 224) has a tightening screw (26) which extends transversely to the longitudinal slot (23) and can be screwed into a screw thread (28) by means of the tightening lever (19), and by which the casing regions on both sides of the longitudinal slot (23) can be moved towards one another, thus reducing the width of the longitudinal slot (23).
  3. Machine according to Claim 2, characterised in that the connection of the tightening screw (26) and tightening lever (19) is made by a toothed clutch (30), which can be released by axial movement of the tightening lever (19).
  4. Machine according to Claim 3, characterised in that the first coupling part (31) of the toothed clutch (30) is joined to the tightening screw (26) for rotation therewith, in that the second coupling part (32), joined to the tightening lever (19) for rotation therewith, coaxially surrounds the first coupling part (31), in that a compression spring (38) effecting the engagement of the two coupling parts (31, 32) is supported between the second coupling part (32) and a radial support shoulder (36) on the first coupling part (31), and in that the axial length of the interengaging coupling teeth (34) of the toothed clutch (30) and the solid length of the compression spring (38) are adapted to one another in such a way that, through axial movement of the second coupling part (32) against the restoring force of the compression spring (38), the coupling teeth (34) of the two coupling parts (31, 32) can be brought out of engagement.
  5. Machine according to one of Claims 2 to 4, characterised in that the locking device (40; 140) has at least two locking slots (44, 45, 46; 144, 145, 146), disposed in the motor casing (10) and offset by an angle of rotation, and a locking cam (47;147) swivellable in the shell casing (20) and capable of engaging positively in each case one of the locking slots (44 - 46; 144 - 146).
  6. Machine according to Claim 5, characterised in that the locking cam (47) is mounted on and rotatable with a coupling sleeve (29) which coaxially surrounds the tightening screw (26) and is operatively connected to the second coupling part (32) of the toothed clutch (30) by means of a claw clutch (50) which is so constructed that its coupling parts remain in engagement with one another on the uncoupling of the toothed clutch (30) by axial movement of the second coupling part (32).
  7. Machine according to Claim 6, characterised in that each locking slot (44 - 46) is formed in a casing peg (41 - 43) projecting radially into the interior from the motor casing (10), and in that the at least two casing pegs (41 - 43) are connected together by a web (52) having the shape of a circular arc and being so disposed that it prevents the swivelling of the locking cam (47).
  8. Machine according to one of Claims 4 to 7, characterised in that the second coupling part (32) of the toothed clutch (30) is integral with the tightening lever (19) which extends at right angles to the second coupling part (32) and is disposed laterally on the shell casing (20).
  9. Machine according to Claim 8, characterised in that the toothed clutch (30) and the claw clutch (50) and their appertaining coupling parts (31, 32) are disposed in an external cavity (33) in the shell casing (20) and only the tightening screw (26) and the coupling sleeve (29) project into the interior of the shell casing (20).
  10. Machine according to Claim 8 or 9, characterised in that the swivelling movement of the tightening lever (19) is limited by a stop (51) fixing the tightening and locking position.
  11. Machine according to Claim 5, characterised in that the locking cam (147) is mounted on and rotatable with a locking lever (57) held swivellably in the shell casing (20), in that the locking lever (57) is loaded by a bending spring (60) in the direction in which the locking cam (147) is swivelled into the locking slot (144 - 146), and in that the locking lever (57) projects sufficiently far out of the shell casing (20) for manual operation against the force of the bending spring (60).
  12. Machine according to Claim 11, characterised in that the handle (12) has a bow (16) which covers the switch bar (18) at a distance therefrom and which is preferably integral with the handle (12), and in that the locking lever (57) is disposed in the bow (16) and its operating surface (59) projects out of a recess (61) in the bow (16).
  13. Machine according to Claim 12, characterised in that the at least two locking slots (144 - 146) are disposed in the outer peripheral surface of the motor casing (10).
  14. Machine according to Claim 12 or 13, characterised in that the clamp device (124) is disposed diametrically opposite the locking device (140).
  15. Machine according to one of Claims 5 to 14, characterised in that a stop boss (55) is disposed on the motor casing (10) and at least one stop lug (53, 54) cooperating therewith is disposed on the shell casing (20), and in that the stop boss (55) and the stop lug (53, 54) are so disposed relative to one another that, when they bear one against the other, the locking cam (47; 147) and a locking slot (44 - 46; 144 - 146) of the locking device (40, 140) are in alignment with one another.
  16. Machine according to Claim 2, characterised in that the connection between the tightening screw (26) and the tightening lever (19) is made via an uncoupling member (65), which is connected on the one hand to the tightening lever (216) by way of a toothed clutch (230) and on the other hand to the tightening screw (26) by way of a claw clutch (250), the toothed clutch (230) being releasable through the axial movement of the uncoupling member (65).
  17. Machine according to Claim 16, characterised in that the tightening lever (216) is held swivellably, coaxially with the tightening screw (26), in the shell casing (20) and is joined to and rotatable with a coupling sleeve (229) coaxially surrounding the tightening screw (26) and carrying the one toothed ring of the toothed clutch (230), in that the uncoupling member (65) is in the form of a sleeve which is provided with a mushroom handle (66) and which coaxially embraces the free end, forming the one coupling part of the claw clutch (250), of the tightening screw (26), and on the one hand forms the other coupling part of the claw clutch (250) and on the other hand carries the other toothed ring of the toothed clutch (230), in that a compression spring (38) effecting the engagement of the toothed rings of the toothed clutch (230) is supported between a support shoulder (37) on the uncoupling member (65) and a support shoulder (36) on that end (67) of the tightening screw (26) that forms the other coupling part of the claw clutch (250), and in that the axial length of the interengaging coupling teeth of the toothed clutch (230) and the solid length of the compression spring (38) are adjusted to one another in such a way that through axial movement of the uncoupling member (65) against the restoring force of the compression spring (38), the coupling teeth of the toothed clutch (230) can be brought out of engagement.
  18. Machine according to Claim 17, characterised in that the locking device (240) has at least two locking slots (244 - 246), disposed in the motor casing (10) and offset by an angle of rotation, and a locking cam (247) attached, preferably integrally, to the tightening lever (216) and capable of engaging positively in each case one of the locking slots (244 - 247).
  19. Machine according to Claim 18, characterised in that the tightening lever is in the form of a bow which covers the switch bar (18) at a distance therefrom and which, at its end remote from its pivot point, can be locked to the handle (12) by means of a snap fastener (64).
  20. Machine according to one of Claims 5 to 19, characterised in that a contact element (71, 72, 70) of a breaker contact (69) is in each case disposed in the locking slots (244 - 246), on the one hand and on the locking cam (247), on the other hand, said breaker contact being connected in the electric connecting line between an on/off switch, which can be operated by the switch bar (18), for the electric drive motor [sic] and being so designed that it is closed only when the locking cam (247) has been swivelled into the locking slot (244 - 246).
  21. Machine according to Claim 20, characterised in that, in each locking slot (244 - 247), two contact springs (71, 72) are provided which lie opposite one another at a distance from each other, one of which is connected to a first plug contact (74), while the other is connected to a second plug contact (75), an output pole of the on/off switch (68), which is in the form of a two-pole switch, being connected to the first plug contact (74) and one current brush of the electric drive being connected to the second plug contact (75), and in that the locking cam (247) has, on two opposite sides, contact surfaces which are connected via a contact bridge (70) and which bear against the two contact springs (71, 72) when the locking cam (247) is in the locking position in the locking slot (244 - 246).
EP91909786A 1990-07-17 1991-05-28 Hand-held electrical machine tool, in particular angle grinding machine Expired - Lifetime EP0539382B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4022668 1990-07-17
DE4022668A DE4022668A1 (en) 1990-07-17 1990-07-17 ELECTRIC HAND TOOL, IN PARTICULAR ANGLE GRINDING MACHINE
PCT/DE1991/000455 WO1992001535A1 (en) 1990-07-17 1991-05-28 Hand-held electrical machine tool, in particular angle grinding machine

Publications (2)

Publication Number Publication Date
EP0539382A1 EP0539382A1 (en) 1993-05-05
EP0539382B1 true EP0539382B1 (en) 1994-10-19

Family

ID=6410426

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91909786A Expired - Lifetime EP0539382B1 (en) 1990-07-17 1991-05-28 Hand-held electrical machine tool, in particular angle grinding machine

Country Status (7)

Country Link
US (1) US5407381A (en)
EP (1) EP0539382B1 (en)
JP (1) JP3032006B2 (en)
BR (1) BR9106644A (en)
DE (2) DE4022668A1 (en)
ES (1) ES2064106T3 (en)
WO (1) WO1992001535A1 (en)

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Also Published As

Publication number Publication date
DE4022668A1 (en) 1992-01-23
US5407381A (en) 1995-04-18
DE59103294D1 (en) 1994-11-24
EP0539382A1 (en) 1993-05-05
ES2064106T3 (en) 1995-01-16
JPH05508353A (en) 1993-11-25
BR9106644A (en) 1993-06-08
WO1992001535A1 (en) 1992-02-06
JP3032006B2 (en) 2000-04-10

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