Bayonet coupling and machining unit with such bayonet coupling

Abstract

A bayonet coupling for mounting of a tool on a drive shaft of a machining unit. The drive shaft is connected to the tool via a bayonet coupling, which includes two coupling parts. The one coupling part is provided with a receiving groove for an engaging tab placed on the other coupling part. The receiving groove has a first section with an extension parallel to the axis of rotation and the second section of the receiving groove has an extension transverse, perpendicular, to the axis of rotation, so that the tool is driven via the engagement of the bayonet coupling.

Claims

1. A system comprising: a bayonet coupling, a tool with tool elements, and a driveshaft attached to a motor for driving the tool about an axis of rotation, wherein the bayonet coupling is configured for mounting of the tool with tool elements on the drive shaft wherein the drive shaft is connected in driving manner either directly or indirectly to the tool via the bayonet coupling, and wherein the bayonet coupling comprises two coupling parts, the one coupling part being provided with a receiving groove for an engaging tab on the other coupling part, which receiving groove has a first section with an extension parallel to the axis of rotation and a second section with an extension transverse, perpendicular, to the axis of rotation, so that the tool is driven via the engagement of the bayonet coupling, wherein the second section of the receiving groove has an extension on either side of the first section, so as to form a T-shaped receiving groove, and the bayonet coupling is devised with at least one locking tab with barbs for engaging with a corresponding toothing or a number of projections to establish a locking engagement of the locking tabs with the toothing or the projections upon rotation of the tool.

2. The system according to claim 1, wherein each locking tab comprises a weakening line so that the locking tab is damaged when the tool is removed from the drive shaft's hub portion.

3. The system according to claim 1, wherein one or more of the toothings or projections are placed on a hub portion on the drive shaft, and at least one locking tab is placed in a bore of the tool, and the bore is designed to receive the hub portion.

4. The system according to claim 1, wherein the coupling part with the receiving groove is the hub portion, the receiving groove being arranged at an outer perimeter of the hub portion, and the coupling part with the engaging tab is arranged in the bore of the tool.

5. The system according to claim 4, wherein the engaging tab comprises two locking tabs directed against one another, and the toothing or the projections are arranged in the receiving groove's second section.

6. The system according to claim 1, wherein the coupling part with the engaging tab is a hub portion, the engaging tab being arranged on an outer perimeter of the hub portion, and the coupling part with the receiving groove is arranged in the bore of the tool.

7. The system according to claim 6, wherein the receiving groove's boundary contains locking tabs on either side of the receiving groove's first section, and the toothing or the projections are arranged on the hub portion on the dorsal engaging surface of the engaging tab.

8. The system according to claim 1, wherein the one coupling part is provided with at least two receiving grooves, and the second coupling part is provided with at least two engaging tabs, so that the number of receiving grooves is at least the same as the number of engaging tabs.

9. The system according to claim 1, wherein the receiving groove's second section has a size such that the engaging tab can slide into it without risk of movement in the direction of the axis of rotation.

10. A machining unit, for grinding, sanding, polishing or similar work tasks, wherein the machining unit comprises the system according to claim 1.

11. A bayonet coupling for engaging a tool to be driven about an axis of rotation by a drive shaft of a machine, the bayonet coupling comprising: a first coupling part and a second coupling part, the first coupling part having a receiving groove for an engaging tab on the second coupling part, wherein the receiving groove has a first section with a first extension and a second section with a second extension transverse, perpendicular, to the first extension, wherein the second section of the receiving groove has an extension on either side of the first section, so as to form a T-shaped receiving groove, and at least one locking tab with barbs configured to engage with a corresponding toothing or a number of projections and to establish a locking engagement of the locking tabs with the toothing or the projections.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows a bayonet coupling for securing of a onetime-use tool to a drive shaft in a machining unit;

(3) FIG. 2 shows a coupling part of the bayonet coupling on a hub portion of a drive shaft;

(4) FIG. 3a shows the hub portion's coupling part from a first angle; and

(5) FIG. 3b shows the hub portion's coupling part from another angle;

(6) FIG. 3c shows the hub portion's coupling part from another angle;

(7) FIG. 3d shows the hub portion's coupling part from another angle;

(8) FIG. 4 shows the toothing or projection on the hub portion;

(9) FIG. 5 shows a tool with bore with resilient tabs; and

(10) FIG. 6 shows details of the bore with resilient tabs and a lower collar.

DETAILED DESCRIPTION

(11) The embodiment is described in relation to a bayonet coupling with two couplings, where the coupling part with the receiving groove is placed on the outside of a hub portion, seated on a drive shaft, while the coupling part with the engaging tab is placed in a bore. The bore is part of a tool. The bayonet coupling may have a different configuration, as described above.

(12) FIG. 1 shows a tool 1 which is to be secured to a drive shaft 2. The drive shaft 2 is driven by a motor (not shown in the figures) for rotation about an axis of rotation 16. The tool has mounted tool elements 3, such as grinding elements or polishing elements. On the drive shaft is seated a hub portion. The hub portion is designed with two receiving grooves 5, while only one receiving groove can be seen in FIG. 1. The tool 1 has a bore 6 placed centrally on the outside of the tool 1. Further down in the bore are two engaging tabs 7 (only one engaging tab can be seen in FIG. 1). As mentioned above, it is possible to have more or fewer receiving grooves and engaging tabs.

(13) The hub portion 4 has a T-shaped receiving groove 5, and when the hub portions 4 is placed in the bore 6 the tool 1 can be rotated both clockwise and counterclockwise, and thus establish a locking engagement both in clockwise and counterclockwise rotation. This ensures that the machining unit is firmly seated on the drive shaft, regardless of the direction in which the tool rotates.

(14) FIG. 2 shows a hub portion, respectively right and left part of the second section of two different receiving grooves 5.

(15) FIGS. 3a-3d shows the receiving groove from different angles. On the hub portion 4 shown there are two receiving grooves, each having a first section and a second section, which second section is divided into a right part 9 and a left part 8.

(16) FIG. 4 shows the hub portion 4 with the right part of the second section of the receiving groove 9 and the left part of the second section of the receiving groove 8. In both right and left parts of the second section of the receiving groove there is placed a toothing 11. The toothing faces away from the first section of the receiving groove and interacts as a ratchet with the bore's locking tabs. The toothing ensures that the tool cannot rotate opposite the locking direction, for example, if the rotation stops suddenly, thereby ensuring that the tool does not drop off during use.

(17) FIG. 5 shows the outside of the tool 1. The bore 6 is placed centrally on the outside of the tool 1. In the bore 6 are placed two engaging tabs 7 opposite each other.

(18) FIG. 6 shows the inner portion of the bore. There are two engaging tabs 7, each one comprising two locking tabs 12, where the locking tabs are facing each other. On the outside of the locking tabs there is formed a barb 13. The barbs of the locking tabs form the second part of the ratchet together with the toothing 11 in the receiving groove 5 (FIG. 4).

(19) The locking tabs 12 furthermore have a weakening line 14. When the bayonet coupling is removed, the locking tabs 12 will be bent or broken off, so that it is possible to turn the two parts of the bayonet coupling against the ratchet. The use of weakening lines is preferable for onetime use of machining units.

(20) In the lowermost portion of the bore 6 there is placed a collar 15, which is perpendicular to the bore 6. The collar 15 means that the hub portion 4 cannot go through the tool 1, but instead the hub portion 4 is maintained at the height where the receiving groove 5 and engaging tab 7 have the proper height so that they easily engage with each other. Furthermore, the hub portion will be clamped between engaging tabs and the collar and thus ensure that the tool has no movement axially along the axis of rotation during use.

(21) Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(22) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements. The mention of a “unit” or a “module” does not preclude the use of more than one unit or module.

FIGURE REFERENCES

(23) 1. Tool 2. Drive shaft 3. Tool elements 4. Hub portion 5. Receiving groove. 6. Bore 7. Engaging tab 8. Left part of second section of the receiving groove 9. Right part of second section of the receiving groove 10. First section of the receiving groove 11. Toothing 12. Locking tab 13. Barb 14. Weakening line 15. Collar 16. Axis of rotation