Clamping device

Abstract

A clamping device for axially clamping a disk-shaped tool on a flange of a spindle of a machine tool, includes a clamping disk which rests against the tool in a friction-fitting manner in the clamped state, a screw which is screwed into a threaded receiving opening in an end face of the spindle, an operating element which is connected to the screw in a rotationally fixed manner, and a first securing element which interacts with a corresponding second securing element provided on a flange such that when the screw is at least partly introduced into the receiving opening, the clamping disk is rotationally secured to the flange in a form-fitting manner, where the clamping disk can be rotated relative to the screw and the operating element. The first securing element can be rotated relative to the screw and is mounted in a rotationally fixed manner relative to the clamping disk.

Claims

1. A clamping device for axially clamping a disk-shaped tool on a flange of a drivable spindle of a hand-held machine tool, comprising: a clamping disk, wherein the clamping disk is restable against the disk-shaped tool in a friction-fitting manner in a clamped state; a screw, wherein the screw is screwable into a threaded receiving opening formed in an end face of the spindle; an operating element, wherein the screw and the operating element are each an individual component and wherein the screw and the operating element are is connectable to each other in a rotationally fixed manner such that a manual force introduced into the operating element is transmitted to the screw in a form of an application torque; and a first securing element, wherein the first securing element interacts with a second securing element provided on the flange such that when the screw is at least partly introduced into the receiving opening, the clamping disk is rotationally secured to the flange in a form-fitting manner, wherein the clamping disk is rotatable relative to the screw and the operating element; wherein the first securing element is rotatable relative to the screw and is mounted in a rotationally fixed manner relative to the clamping disk; wherein the first securing element is an individual component which is a sleeve with a polygonal internal profile and wherein the second securing element has an external profile that corresponds to the polygonal internal profile of the first securing element such that the first securing element is pushable onto the second securing element; wherein the clamping disk has a central recess and wherein the first securing element has an external profile that corresponds to the central recess such that the first securing element is insertable into the clamping disk.

2. The clamping device according to claim 1, wherein a thread of the screw is only capable of engaging in the thread of the receiving opening if, in an assembled condition of the clamping device, the first securing element has, at least partly, a form-fit interaction with the second securing element.

3. The clamping device according to claim 1, wherein the operating element is a cover which encloses the clamping disk at least partially.

4. The clamping device according to claim 1 further comprising a bearing, wherein the bearing provides for rotational decoupling of the screw and clamping disk if the clamping disk is rotationally secured to the flange in a form-fitting manner.

5. The clamping device according to claim 1, wherein the operating element, the clamping disk, and the first securing element are arranged coaxially with respect to one another on the screw and secured to the screw by a retaining ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of a clamping device according to the invention with a disk-shaped tool in an assembled condition of the clamping device;

(2) FIG. 2 is a perspective view of the clamping device in a disassembled condition of the clamping device without the disk-shaped tool;

(3) FIG. 3 is a perspective view of the clamping device in a disassembled condition of the clamping device;

(4) FIG. 4 is a side cross-section view of the clamping device along line of intersection A-A in FIG. 1;

(5) FIG. 4a is a cross-section view of the clamping device along line of intersection B-B in FIG. 4;

(6) FIG. 5 is a further side cross-section view of the clamping device along line of intersection A-A in FIG. 1;

(7) FIG. 5a is a cross-section view of the clamping device along line of intersection B-B in FIG. 5;

(8) FIG. 6 is a perspective view of the spindle;

(9) FIG. 7 is a side cross-section view of the spindle;

(10) FIG. 8 is a perspective view of the first securing element; and

(11) FIG. 9 is a further perspective view of the first securing element.

DETAILED DESCRIPTION OF THE DRAWINGS

(12) A clamping device 1 according to the invention is shown in an assembled condition in FIG. 1.

(13) The clamping device 1 essentially comprises a screw 2, an operating element 3, a first running disk 24, a needle roller thrust bearing 23, a second running disk 25, a clamping disk 7, a first securing element 8 and a counter-clamping disk 9 (see FIGS. 1, 2, 3). The clamping device 1 interacts with a spindle 10 of a hand-held machine tool not shown in the Figures. The spindle 10 additionally includes a second securing element 12, which is located on a flange 13 of the spindle 10 (see FIGS. 2, 3).

(14) The clamping device 1 serves for axial clamping of a disk-shaped tool 14 to the flange 13 of the driven spindle 10 shown on the right in FIG. 1. The driven spindle 10 belongs to a hand-held machine tool not shown in the Figures, which may, for example, be an angle grinder. The disk-shaped tool 14 may, for example, be a plate-shaped grinding wheel.

(15) It is, however, also possible for the disk-shaped tool 14 to be a flat cutting disk. The hand-held machine tool (not shown) may be an angle grinder or similar. Alternatively, the clamping device according to the invention may also be implemented in a non-hand-held machine tool.

(16) The clamping device 1 incorporates a clamping disk 7 which, in an assembled or clamped condition of the clamping device 1, rests against the tool 14, for example, a plate-shaped grinding wheel, in a friction-fitting manner, in order to clamp it to the spindle 10 of the hand-held machine tool (not shown).

(17) The screw 2 is a central screw, which, in the assembled condition, holds together the entire clamping device 1. The screw 2 includes a screw head 2a and a thread 2b, which can be screwed into a thread 15, which is formed in a receiving opening 16 on a free end face 17 of the spindle 10.

(18) The operating element 3 is formed essentially as a cover with a central recess 18. The recess 18 serves to receive and provide a form-fit connection of the operating element 3 with the screw 2. As a result of the form-fit of operating element 3 and screw 2, the operating element 3 is connected to the screw 2 in a rotationally fixed manner such that a manual force introduced into the operating element 3 by rotation of operating element 3 in a radial direction R is transmitted to the screw 2 in the form of an application torque. The form-fit connection between the screw 2 and the operating element 3 is achieved by means of a corresponding profile device on the central recess 18 of operating element 3 and the screw head 2a of the screw 2. Alternatively, the screw 2 and the operating element 3 can also be designed as a single piece, or joined by means of a substance-to-substance bond (adhesive bonding, welding, soldering or similar).

(19) The first securing element 8 of the clamping device 1 is designed as a sleeve with a hexagonal internal profile 19 in the implementation example shown in FIG. 1 (see also FIGS. 8 and 9). It is thus essentially similar to a nut with hexagonal socket. In addition, the first securing element 8 incorporates a polygonal external profile 20 at one end 8a. As shown in particular in FIG. 8, the polygonal external profile 20 is essentially a square profile with chamfered corners.

(20) The clamping disk 7 has an essentially square recess 21 in the center. The shape of the recess 21 corresponds to the square external profile 20 of the first securing element 8, so that the square external profile 20 of the first securing element 8 can be inserted into the square recess 21 of the clamping disk 7. As a result, the first securing element 8 and the clamping disk 7 can be connected to each other in a form-fitting manner.

(21) Alternatively, the first securing element 8 and the clamping disk 7 can also have a different external profile and recesses that correspond to one another. Furthermore, the first securing element 8 and the clamping disk 7 can also be designed as a single piece, or joined to one another by means of a substance-to-substance bond.

(22) A second securing element 12 that corresponds to the first securing element 8 is positioned on the flange 13 of the spindle 10. As shown in particular in FIGS. 2, 3, 6, the second securing element 12 incorporates a hexagonal external profile 22 which corresponds to the hexagonal internal profile 19 of the first securing element 8. If hexagonal internal profile 19 of the first securing element 8 is engaged with the hexagonal external profile 22 of the second securing element 12, not only the first securing element 8 and the second securing element 12 but also the clamping disk 7 and the flange 13 are rotationally secured to each other in a form fitting manner.

(23) As already mentioned above, this is realized in the present implementation example in such a way that the external profile 20 of the first securing element 8 projects into the corresponding recess 21 of the clamping disk 7, the internal profile 19 of the first securing element 8 is pushed onto the external profile 22 of the second securing element 12, and the screw 2 is screwed in direction N through the clamping disk 7, the first securing element 8, the disk-shaped tool 14 and into the receiving opening 16 equipped with the thread 15 of the spindle 10 (see FIG. 3). The clamping disk 7, the first securing element 8 and the second securing element 12 are thus connected to each other in a form-fitting manner.

(24) According to the invention, the first securing element 8 of the clamping device 1 can be rotated relative to the screw 2, and is mounted in a rotationally fixed manner relative to the clamping disk 7.

(25) The clamping device 1 has, in the present case, a bearing 23 in the form of a needle roller thrust bearing which is supported between two running disks 24, 25. The bearing 23 designed as a needle roller thrust bearing serves for rotational decoupling of screw 2 and clamping disk 7, if the clamping disk 7 is rotationally secured to the flange 13 in a form-fitting manner.

(26) As can also be seen in FIG. 1, the screw 2, the operating element 3, the two running disks 24, 25, the first securing element 8 and the clamping disk 7 are arranged coaxially in respect of one another.

(27) In the assembled condition (see FIG. 2), the operating element 3, the clamping disk 7, the first securing element 8, the two running disks 24, 25 and the needle roller thrust bearing 23 are arranged on the screw 2, and secured to the latter by means of a retaining ring 26 in the form of a snap ring. An additional ring 27 serves to ensure that the force acting axially in the assembled condition of the clamping device 1 is redirected such that a radial force component arises on the retaining ring 26.