Joining system and method of detachably and securely joining two members

• US 5,845,384 A
• Filed: 06/14/1996
• Issued: 12/08/1998
• Est. Priority Date: 06/14/1995
• Status: Expired due to Term

• Current Assignee: Fritz Schunk GmbH & Company KG Fabrik Fur Spann-Und Greifwerkzeuge
• Original Assignee: Fritz Schunk GmbH & Company KG Fabrik Fur Spann-Und Greifwerkzeuge
• Inventors: Retzbach, Thomas
• Primary Examiner(s): Watson, Robert C.
• Application Number:
  US08/675,462
• Time in Patent Office: 907 Days
• Field of Search: 72/402, 29/252, 29/243.52, 29/283.5, 29/816, 29/505, 29/515, 29/517, 29/520, 29/522.1, 29/450, 29/282
• US Class Current: 29/450
• CPC Class Codes: B23P 11/022 by using pressure fluids
• CPC Class Codes: F16B 4/002 engaging or disengaging by means of fluid pressure
• CPC Class Codes: F16D 1/0805 with radial clamping due to deformation of a resilient body or a body of fluid F16D1/091 takes precedence; elastic couplings F16D3/80; fluid pressure clutches F16D25/04
• CPC Class Codes: F16D 1/0829 with radial loading of both hub and shaft by an intermediate ring or sleeve F16D1/0817, F16D1/0823, F16D1/093 take precedence
• CPC Class Codes: F16D 1/0858 due to the elasticity of the hub (including shrink fits)
• CPC Class Codes: Y10T 29/4987 Elastic joining of parts
• CPC Class Codes: Y10T 29/5383 having fluid operator
• CPC Class Codes: Y10T 29/53987 Tube, sleeve or ferrule
• CPC Class Codes: Y10T 29/53996 by deforming

Abstract

A joining system for repeatedly but securely joining two members, where one member is temporarily deformed during the joining process in such a way that an effective peripheral contour corresponds to the corresponding effective peripheral contour of the other member with a given tolerance, and after the two members have been positioned, a tight pressure fit of the two effective peripheral contours is established by at least partial elastic recovery of the deformable member. According to this invention, the original peripheral contour of the deformable member has some sections inside the peripheral contour of the other member and has some sections outside that peripheral contour. The deformation of at least one member takes place through the controlled action of radial compressive forces on certain sections of the peripheral contour of the deformable member. The tight mutual pressure fit of the two peripheral contours is achieved in predetermined peripheral sections by elastic recovery of the deformable member.

Claims

1. A system for repeated tight joining of two generally concentric members which, in their non-deformed state, have at least a partial interference fit, said system comprising:

a first member having a permanent peripheral contour;

a second deformable member formed with a peripheral surface having first portions which are inside the peripheral contour of said first member and having second portions which are outside the peripheral contour of said first member;

means for applying radial forces to said second member in at least two predetermined circumferentially spaced locations to temporarily deform said second member to conform said peripheral surface to the shape of said peripheral contour of said first member to enable said first and second members to be joined together, whereby an interference fit is formed between said first and second members when the radial forces are removed from said second member and said second member returns, at least partially, to its original shape.

2. The system according to claim 1, wherein:

said first member is a rigid shaft;

said second, deformable member is a hollow body;

said hollow body has a polygonal inside peripheral contour with arc-shaped inside peripheral sections and curved outside transitional sections that can undergo elastic deformation until they are congruent with the outside peripheral contour of said rigid shaft.

3. The system according to claim 2, wherein:

said hollow body is designed as a cylindrical socket and said shaft has a cylindrical peripheral contour, where the effective inside peripheral contour of said socket is formed with three angularly spaced peripheral sections with a shallow curvature and three transitional curves, said peripheral sections and said transitional curves alternating around the peripheral contour of said socket, said socket being adapted to be deformed to an approximately circular shape by radial forces acting radially inward on said transitional curves, where the largest diameter of the peripheral contour of said deformed socket is slightly larger than the diameter of said shaft.

4. The system according to claim 1, wherein:

said first member is formed with a recess therein;

said second deformable member is formed as a hollow body;

the original outer peripheral contour of said hollow body has some sections inside the peripheral contour of the recess and other sections outside the peripheral contour of the recess and it is deformable by the radial forces acting radially outward on the sections inside the peripheral contour of the recess.

5. The system according to one of claims 1 to 4, wherein the effective peripheral contours of the two members are quadrilateral or polygonal with arc-shaped sections.

6. The system according to one of claims 1 to 4, wherein:

said deformable hollow cylindrical member has a reduced wall thickness in the sections that are exposed to the forces acting radially.

7. A method for detachably tight joining of two generally concentric members which, in their non-deformed state, have at least a partial interference fit, the method comprising the steps of:

deforming at least one of the members by radial forces during the joining operation;

positioning the deformed member in the intended joining position with respect to the other member; and

releasing the radial forces whereby a tight joint is created by a subsequent elastic recovery of the deformed member;

wherein the peripheral contour of the deformable member is provided with some peripheral sections inside the effective peripheral contour of the other member and with other peripheral sections outside the effective peripheral contour;

the radial forces are exerted on predetermined peripheral sections of the peripheral contour of the deformable member so its effective peripheral contour corresponds to the effective peripheral contour of the other member within a given tolerance; and

after positioning the two members, the peripheral sections that are not exposed to the radial forces are brought in tight press fit with the peripheral contour of the other member by elastic recovery of the deformed member.

8. The method according to claim 7, wherein the method applies for repeatable mounting of a deformable hollow body on a fixed contour shaft:

the inside peripheral contour of the hollow body is provided with some peripheral sections that are inside the effective peripheral contour of the shaft and with other peripheral sections outside the contour; and

the radial forces act from the outside to the inside of the deformable hollow body are brought to bear on the peripheral sections outside the peripheral contour.

9. The method according to claim 7, wherein the method applies for repeated mounting of an elastically deformable hollow body in a recess of a fixed contour member:

the outer peripheral contour of the deformable hollow body is provided with some peripheral sections located inside the effective peripheral contour of the fixed contour member and with some peripheral sections outside the effective peripheral contour of the fixed contour member; and

the radial forces act from the inside to the outside of the deformable hollow body are brought to bear on the inside peripheral sections.

10. The method according to one of claims 7 to 9, wherein:

the polygonal peripheral contour of the deformable member is produced by machining.

11. The method according to one of claims 7 to 9, wherein

the polygonal peripheral contour of the deformable member is produced by compression molding without cutting.

12. A device for mounting a deformable hollow body on a shaft, comprising:

a housing having a central recess with several press jaws arranged in said recess with an angular offset relative to each other and having a chucking device for forced displacement of said press jaws;

said press jaws have on their inside peripheral surface at least one projection opposite a peripheral section of the deformable hollow body that is outside the peripheral contour of said recess;

said chucking device being shaped and configured to produce a pressure that acts radially inward on said press jaws; and

said deformable hollow body having a polygonal inside peripheral contour with arc-shaped inside peripheral sections and curved outside transitional sections that can undergo elastic deformation until they are congruent with the outside peripheral contour of a rigid shaft wherein said deformable hollow body is designed as a cylindrical socket, where the effective inside peripheral contour of said socket is formed with three angularly spaced peripheral sections with a shallow curvature and three transitional curves, said peripheral sections and said transitional curves alternating around the peripheral contour of said socket, said socket being adapted to be deformed to an approximately circular shape by radial forces acting radially inward on said transitional curves, where the largest diameter of the peripheral contour of said deformed socket is slightly larger than the diameter of said shaft.

13. The device according to claim 12, wherein said chucking device is hydromechanical, having one hydraulic pressure chamber on the radial outside of each said press jaw and each has a control element arranged so it can move in said housing.