DEVICE FOR POLISHING AN OPTICAL SURFACE OF OPTICAL LENSES, POLISHING MACHINE AND METHOD FOR POLISHING

Abstract

A device for polishing an optical surface of lenses, a connecting element for being fitted on a polishing machine on one end of the device, and a polishing wheel on another end, the polishing wheel having an axially disposed drive shaft running radially to a longitudinal center axis of a spindle, the device having a crown or bevel gear by which the polishing wheel is drivable via the drive shaft by a rotary spindle part, the crown or bevel gear formed by a cogwheel disposed on one end of the drive shaft and by a crown or bevel wheel rotatably mounted on a fixed bearing sleeve running coaxially to the spindle of the polishing machine, an additional toothing on an outer circumference of the crown or bevel wheel for driving the polishing wheel via the drive shaft via a toothed wheel driven by a separate drive motor.

Claims

1. A device (1) for polishing an optical surface (2) of optical lenses (3), comprising a connecting element (5) for being fitted on a polishing machine (4) being provided on one end of the device (1), and a polishing wheel (11) being disposed on another end of the device (1), said polishing wheel (11) having an axially disposed drive shaft (15) running radially to a longitudinal center axis (14) of a spindle (9) of the polishing machine (4), and the device (1) having a crown gear or a bevel gear (18) by which the polishing wheel (11) is drivable via the drive shaft (15) by a rotary part (8) of the spindle (9) of the polishing machine (4), wherein the crown or bevel gear (18) is formed by a cogwheel (19) disposed on one end of the drive shaft (15) and by a crown or bevel wheel (23) rotatably mounted on a fixed bearing sleeve (21) of the device (1), said bearing sleeve (21) running coaxially to the spindle (9) of the polishing machine (4), an additional toothing (25) being provided on an outer circumference (24) of the crown or bevel wheel (23), the polishing wheel (11) being drivable via the drive shaft (15) by means of said toothing (25) via a toothed wheel (28) driven by a separate drive motor (26).

2. The device according to claim 1, wherein, on an end of the connecting element (5) directed at the polishing machine (4), the connecting element (5) has a bearing pin (6) which is receivable and mounted by a clamping system (7) of the rotary part (8) of the spindle (9) of the polishing machine (4), and that a mounting frame (13) for receiving and supporting the polishing wheel (11) is provided on an end of the connecting element (5) facing away from the polishing machine (4).

3. The device according to claim 2, wherein the clamping system (7) is a hydraulic expansion chuck.

4. The device according to claim 2, wherein the drive shaft (15) of the polishing wheel (11) is mounted on lateral legs (16) of the U-shaped mounting frame (13).

5. The device according to claim 2, wherein the drive shaft (15) protrudes over one side of the mounting frame (13), the cogwheel (19) being mounted on the protruding part (20) of the drive shaft (15).

6. The device according to claim 2, wherein the polishing wheel (11) is mounted between the two lateral legs (16) of the mounting frame (13) so as to have low backlash.

7. The device according to claim 1, wherein the outer circumference of the polishing wheel (11) has an elastic rubber coating (10).

8. The device according to claim 7, wherein the outer circumference of the elastic rubber coating (10) has a convex surface.

9. The device according to claim 1, wherein the bearing sleeve (21) has a retaining element (29) for the drive motor (26), in or on which the drive motor (26) with its longitudinal center axis (27) is disposed parallel to the longitudinal center axis (14) of the spindle (9) of the polishing machine (4).

10. A polishing machine (4) for polishing an optical surface (2) of optical lenses (3) using a device (1) according to claim 1.

11. A method for polishing an optical surface (2) of optical lenses (3) using a device (1) according to the claim 1 or a polishing machine (4), comprising the following steps: a. Positioning the polishing wheel (11) with its elastic rubber coating (10) on the surface (2) of the lens (3); b. Rotating the spindle (9) of the polishing machine (4) around its longitudinal center axis (14) while the crown or bevel wheel (23) is blocked while simultaneously rotating the polishing wheel (11) around the longitudinal center axis (14) of the spindle (9) of the polishing machine (4) and the longitudinal center axis (31) of the drive shaft (15), the cogwheel (19) rolling on the blocked crown or bevel wheel (23) at a constant transmission ratio; c. Changing the transmission ratio between the crown or bevel wheel (23) and the cogwheel (19) while simultaneously changing the speed or changing the rotating direction of the polishing wheel (11) by operating the drive motor (26).

12. The method according to claim 11, wherein the rotating direction of the drive motor (26) is switched, the speed of the polishing wheel (11) being changed.

13. The method according to claim 11, wherein the speed of the drive motor (26) is changed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Hereinafter, a preferred embodiment of the device will be described in more detail with reference to the drawings.

[0022] FIG. 1 shows a longitudinal section through the device according to the invention,

[0023] FIG. 2 shows a diagram of a first example of a profile imprint and

[0024] FIG. 3 shows a diagram of a second example of a profile imprint.

DETAILED DESCRIPTION

[0025] Device 1 shown in FIG. 1 is provided for polishing an optical surface 2 of optical lenses 3, such as aspheres, spheres, plane surfaces and free formed surfaces, eyeglass lenses and the like, and is preferably disposed on a CNC polishing machine 4. To this end, one end of device 1 has a connecting element 5, which is provided with a bearing pin 6 on the end directed at polishing machine 4. Bearing pin 6 of connecting element 5 is provided for establishing a connection and for power transmission between polishing machine 4 and device 1 and is receivable and mounted by a clamping system 7, which can be a hydraulic expansion chuck, for example, of a rotary part 8 of a spindle 9 of polishing machine 4.

[0026] For polishing optical surface 2 of optical lenses 3, a polishing wheel 11 provided with an elastic rubber coating 10 is provided on another end of device 1, said polishing wheel 11 having a convex surface on outer circumference 12 of rubber coating 10 and being disposed and mounted on an end of connecting element 5 of a U-shaped mounting frame 13, said end facing away from polishing machine 4. Polishing wheel 11 is disposed on an axially disposed drive shaft 15 running radially to a longitudinal center axis 14 of spindle 9 of polishing machine 4, said drive shaft 15 preferably being mounted on lateral legs 16 of U-shaped mounting frame 13 by means of rolling bearings 17, polishing wheel 11 being disposed between two lateral legs 16 on drive shaft 15 so as to have low backlash.

[0027] Furthermore, device 1 has a crown gear or a bevel gear 18 which serves to drive polishing wheel 11 by means of rotary part 8 of spindle 9 of polishing machine 4 via drive shaft 15. Crown or bevel gear 18 is formed by a cogwheel 19 disposed on an end of drive shaft 15, drive shaft 15 protruding over one side of mounting frame 13 or over one of the two legs 16 of mounting frame 13 and cogwheel 19 being mounted on the protruding part 20 of drive shaft 15.

[0028] Crown or bevel gear 18 is formed by a crown or bevel wheel 23 rotatably mounted on a fixed bearing sleeve 21 of device 1 via preferably additional rolling bearings 22, said bearing sleeve 21 running coaxially to spindle 9 of polishing machine 4. An additional toothing 25 is disposed on an outer circumference 24 of crown or bevel wheel 23, polishing wheel 11 being drivable via drive shaft 15 by means of said toothing 25 via a toothed wheel 28 driven by a separate drive motor 26, whose longitudinal center axis 27 is disposed at a distance and parallel to longitudinal center axis 14 of spindle 9 of polishing machine 4. For fastening drive motor 26, bearing sleeve 21 has a correspondingly disposed retaining element 29.

[0029] Hereinafter, the method for polishing an optical surface 2 of optical lenses 3 using device 1 and polishing machine 4 will be described in more detail.

[0030] Firstly, polishing wheel 11 with its elastic rubber coating is positioned on surface 2 of lens 3 disposed in a workpiece clamping system 30 of polishing machine 4, whereupon spindle 9 of polishing machine 4 begins to rotate around its longitudinal center axis 14 while crown or bevel wheel 23 is blocked while polishing wheel 11 simultaneously rotates around longitudinal center axis 14 of spindle 9 of polishing machine 4 and longitudinal center axis 31 of drive shaft 15. Cogwheel 19 rolls on blocked crown or bevel wheel 23 at a constant transmission ratio.

[0031] Changing the transmission ratio between crown or bevel wheel 23 and cogwheel 19 while simultaneously changing the speed and/or changing the rotating direction of polishing wheel 11 is effected by operating drive motor 26.

[0032] In addition, the rotating direction of drive motor 26 can be switched, the speed of polishing wheel 11 also being changeable. Furthermore, the speed of drive motor 26 can also be changed.

[0033] As previously mentioned, the transmission ratio between crown or bevel wheel 23 and cogwheel 19 changes as soon as drive motor 26 is switched on. Accordingly, the speed of polishing wheel 11 changes. Drive motor 26 can control the rotational speed and the rotating direction irrespective of spindle 9 of polishing machine 4.

[0034] FIG. 2 shows an example of a profile of the polishing imprint with a running spindle 9 of polishing machine 4 and stationary rotation of polishing wheel 11 which is compensated by the rotation of drive motor 26.

[0035] FIG. 3 shows an example of a profile of the polishing imprint with a running spindle 9 of polishing machine 4 and a rotation of polishing wheel 11.