Piston-cylinder assembly with a bellows

• US 7,032,896 B2
• Filed: 05/13/2002
• Issued: 04/25/2006
• Est. Priority Date: 05/11/2001
• Status: Expired due to Fees

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Sachs AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Hupperich, Volker-Oliver, Collis, John
• Primary Examiner(s): SICONOLFI, ROBERT
• Application Number:
  US10/144,328
• Publication Number:
  US 20020189441A1
• Time in Patent Office: 1,443 Days
• Field of Search: 267/220, 267/221, 267/140, 267/152, 267/153, 267/33, 267/64.23, 267/64.24, 267/122, 188/322.17, 280/124.146, 280/124.147
• US Class Current: 267/122
• CPC Class Codes: B60G 2202/312 The spring being a wound spring
• CPC Class Codes: B60G 2204/1242 on a damper, e.g. MacPerson strut
• CPC Class Codes: B60G 2204/128 Damper mount on vehicle body or chassis
• CPC Class Codes: B60G 2204/45021 for limiting upper mount movement of a McPherson strut
• CPC Class Codes: F16F 9/38 Covers for protection or appearance
• CPC Class Codes: F16F 9/58 Stroke limiting stops, e.g. arranged on the piston rod outside the cylinder F16F9/49 takes precedence

Abstract

Piston-cylinder assembly, comprising a container tube, in which a piston rod is guided with freedom of axial movement, which rod is at least partially covered by a sheath tube with at least one elastic fold, where a resilient stop pad is provided concentrically to the piston rod, the end of which pad comes to rest against an end cap during the inward travel of the piston rod, which end cap rests against the container tube in the fully assembled piston rod assembly. The stop pad, the sheath tube, and the end cap form a preassembled unit which is independent of the piston rod assembly, the end cap being pressed onto the container tube by the resilient stop pad during the inward travel of the piston rod into the container tube.

Claims

1. A piston cylinder assembly comprising:

a container tube,

a piston rod guided axially in said container tube,

a resilient stop pad fitted concentrically to the piston rod,

an end cap fitted to the container tube, said end cap being pressed onto the container tube by the resilient stop pad when the piston rod is moved into the container tube, and

a sheath tube fitted to said stop pad and to said end cap, said sheath tube having at least one elastic fold and covering said piston rod between said stop pad and said end cap, said sheath tube, said resilient stop pad, and said end cap being formed as separate parts and assembled to form a preassembled unit which can stand independently of said piston rod and said container tube.

2. A piston-cylinder assembly as in claim 1 wherein said resilient stop pad comprises a form-locking profile which engages said sheath pad in a form-locking manner.

3. A piston-cylinder assembly as in claim 2 wherein said resilient stop pad has an end facing away from said end cap, said form-locking profile being formed on said end.

4. A piston-cylinder assembly as in claim 1 wherein said end cap comprises a circumferential flange which engages said sheath tube in a form-locking manner, said end cap having a radially resilient area near said flange.

5. A piston-cylinder assembly as in claim 4 wherein said end cap comprises axial slots which divide said flange into segments, said circumferential flange being formed on said segments.

6. A piston-cylinder assembly as in claim 1 further comprising a fastening element having a sleeve section, said resilient stop pad having a cylindrical section which engages inside said sheath tube and together with said sheath tube is pressed into said sleeve section.

7. A piston-cylinder assembly as in claim 1 wherein said end cap extends axially beyond said sheath tube.

8. A piston-cylinder assembly as in claim 1 wherein said sheath tube is a bellows.

9. A piston-cylinder assembly as in claim 4 wherein said sheath tube has a circumferential channel, said circumferential flange engaging in said channel in a form-locking manner.

10. A piston-cylinder assembly as in claim 5 wherein said segments have distal ends, said circumferential flange being spaced from said distal ends.

11. A piston-cylinder assembly as in claim 1 wherein said sheath tube has a top end fitted to said stop pad and a bottom end fitted to said end cap.

12. A piston-cylinder assembly as in claim 11 wherein said end cap extends axially beyond said bottom end of said sheath tube.

13. A piston-cylinder assembly as in claim 11 wherein said stop pad is received in said bottom end of said sheath tube prior to fitting said bottom end to said end cap.