Arrangement for providing centre displacement in a machine tool

Patent metadata

Field	Value
Publication number	US-12226839-B2
Application number	US-202017606142-A
Country	US
Kind code	B2
Filing date	Apr 24, 2020
Priority date	Apr 24, 2019
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

Fastening an object onto a lathe, such that the location of the centre of rotation of the object may be adjusted relative to the centre of the lathe axis, wherein the centre of rotation of the object relative to the centre of the lathe may be displaced steplessly and biaxially, according to a predetermined calculation, without removing the object from the chuck.

First claim

The invention claimed is:

1. An arrangement for providing centre displacement in a machine tool, which arrangement comprises:
A) a fastening element for receiving a workpiece or a tool means,
B) a body for fastening the fastening element onto the machine tool, which body comprises a body outer rim shaped as the circumference of a circle,
C) a first centre displacement section,
D) a second centre displacement section, which centre displacement sections are arranged between the fastening element and the body to connect the fastening element with the body,
E) which first centre displacement section comprises:
i) a first inner rim shaped as the circumference of a circle and rotatably arranged onto the body outer rim,
ii) a first outer rim shaped as the circumference of a circle and arranged eccentrically relative to the first inner rim, such that their centre points are not aligned, and
iii) a first aperture which passes through the first centre displacement section and is concentric with the first inner rim,

F) and which second centre displacement section comprises;
i) a second inner rim shaped as the circumference of a circle and rotatably arranged onto the first outer rim,
ii) fastening element fastening means which are configured to fasten the fastening element to the second centre displacement section eccentrically relative to the second inner rim, and
iii) a second aperture which passes through the second centre displacement section, which arrangement further comprises:

G) an end flange which is sized larger than the second aperture and is provided between the second centre displacement section and the fastening element, and
H) a pressure medium operated actuator which is coupled via the first and the second aperture to the end flange, such that
I) in a first mode of the actuator the end flange is located farther from the body, such that the centre displacement sections are rotatable relative to each other and to the body, and that
J) in a second mode of the actuator the end flange is located closer to the body, the centre displacement sections being thereby locked relative to each other and to the body.

2. The arrangement according to claim 1 , wherein the body has a front wall which is configured to be elastically bendable by the effect of pressure of a pressure medium and arranged to operate as a part of the pressure medium operated actuator.

3. The arrangement according to claim 2 , wherein the front wall comprises at least one groove for facilitating the movement of the front wall.

4. The arrangement according to claim 2 , wherein the body forms a pressure chamber which is configured to hold a pressure medium and which chamber operates as said pressure medium operated actuator, the pressure of the pressure medium being arranged to bend the front wall.

5. The arrangement according to claim 4 , wherein the pressure chamber comprises a connector to be coupled with a pressure source external to the chamber.

6. The arrangement according to claim 4 , wherein the pressure needed for moving the end flange is generated in the chamber.

7. The arrangement according to claim 6 , wherein a screw hole and a matching screw plug are arranged in connection with the pressure chamber, which screw plug is turned towards the chamber in order to increase pressure in the chamber.

8. The arrangement according to claim 4 , wherein a back wall of the pressure chamber is bendable and that the arrangement comprises a second actuator which is arranged to act on said back wall.

9. The arrangement according to claim 2 , wherein the actuator is in its first mode when the front wall is forced by the effect of pressure of the pressure medium to bend towards the fastening element, and in its second mode when the front wall is in its rest mode.

10. The arrangement according to claim 2 , which comprises a hydraulic cylinder which is arranged to bend the front wall.

11. The arrangement according to claim 2 , wherein the end flange is provided with a drive pin which extends through the first aperture and the second aperture and is coupled to the front wall to move with the front wall.

12. The arrangement according to claim 1 , which comprises a hydraulic cylinder which is coupled to the end flange for moving the end flange.

13. The arrangement according to claim 1 , which comprises more than two centre displacement sections.

14. The arrangement according to claim 1 , wherein the centre displacement sections are sized relative to one another in such a way that the fastening element is centrable along the centre line of the arrangement.

15. The arrangement according to claim 1 , wherein the pressure medium comprises liquid.

16. The arrangement according to claim 1 , wherein the fastening element is intended for fastening a workpiece to the machine tool.

17. The arrangement according to claim 1 , wherein the fastening element is intended for fastening a tool.

18. The arrangement according to claim 1 , wherein the machine tool is a lathe, a lathe-mill, or a machining centre.

Assignees

• Aalto Univ Foundation Sr

Inventors

• Kuosmanen Petri
• Viitala Raine
• Vainio Valtteri

Classifications

• Y10T279/14

  Eccentric · CPC title

• B23B31/0261

  for centering the tool · CPC title

• B23B31/36 Primary

  with means for adjusting the chuck with respect to the working-spindle · CPC title