Tensioning device for pre-stressing an assembly with a threaded rod

Patent metadata

Field	Value
Publication number	US-10569401-B2
Application number	US-201615091675-A
Country	US
Kind code	B2
Filing date	Apr 6, 2016
Priority date	Apr 9, 2015
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

The invention provides a tensioning device having a traction element and a body. The traction element includes a first lower portion of the traction element that resides in a tie-rod that is able to interlock with a threaded rod and a second upper portion of traction element that resides in a piston, the first and second portions of traction element being integral in displacement. The traction element is axially moveable in a bore of the body and co-axially mounted around the traction element, the body providing a first lower portion of the body that resides in a tubular support sleeve and a second upper portion of body that resides in a cylinder. An annular chamber is formed between the traction element and the body and intended to receive a pressurized fluid.

First claim

The invention claimed is:

1. A tensioning device comprising:
a traction element, and
a body, wherein
(a) the traction element provides a first traction element lower portion that includes a tie-rod able to interlock with a threaded rod located along a central axis of the tensioning device, and a second traction element upper portion that includes a radial flange forming a shoulder between the first traction element lower portion and a piston extending axially therefrom, the first traction element lower portion and the second traction element upper portion being a single, one-piece member, the first traction element lower portion and the second traction element upper portion being integral in displacement;
(b) the traction element is axially movable in a bore of the body mounted co-axially around the traction element, a first body lower portion that includes a support tubular sleeve having an outer cylindrical surface facing radially outwardly from the central axis, and a second body upper portion that includes a cylinder and a radial base extending inwardly therefrom, wherein the second body upper portion includes a circumferential axial collar which extends from the second body upper portion to form a second bore, the support tubular sleeve being located inside the second bore such that the circumferential axial collar overlies a portion of the support tubular sleeve; and
(c) an annular chamber is formed between the traction element and the body and is intended to receive a pressurized fluid;
(d) the annular chamber is formed axially between the radial base of the second body upper portion and the radial flange of the second traction element upper portion and radially between the cylinder of the second body upper portion and the first traction element lower portion; and wherein
(e) the device provides a first sealing means mounted radially between the second body upper portion and the first traction element lower portion, and a second sealing means mounted radially between the second body upper portion and the second traction element upper portion, the two sealing means being positioned axially on either side of the annular chamber to ensure sealing of the annular chamber, wherein when the radial flange is in contact with the radial base, the piston is adjacent to the cylinder with no component therebetween except for one of the two sealing means, the traction element being configured such that: (1) the shoulder of the second traction element upper portion is positionable against the radial base of the second body upper portion of the body, (2) an outer surface of the second traction element upper portion is positioned adjacent to and opposingly facing an inner surface of the bore of the second body upper portion, and (3) the second traction element upper portion and the first traction element lower portion define a threaded bore to threadably engage the threaded rod.

2. The device according to claim 1 , wherein the bore comprises a first bore portion and a second bore portion, the second bore portion co-axial to the first bore portion, wherein the first traction element lower portion is disposed within the first bore portion and is axially movable, and the second traction element upper portion is disposed within the second bore portion and is axially movable.

3. The device according to claim 2 , wherein the annular chamber is formed radially between the second bore portion and the first traction element lower portion.

4. The device according to claim 1 , wherein the tensioning device provides a docking key disposed within the first body lower portion and co-axially mounted around a nut screwed on the threaded rod, and a drive pin having an end that cooperates with the docking key and passes through a radial opening provided in the first body lower portion.

5. The device according to claim 1 , wherein the second body upper portion provides at least one conduit to be supplied by the pressurized fluid and connected to the annular chamber.

6. The device according to claim 1 , wherein the first sealing means and the second sealing means are each separately arranged within a respective cavity provided on one of the body and the traction element to come in sliding contact with the other of the body and the traction element to prevent leakage of the pressurized fluid and maintain the pressure between the body and the traction element.

Assignees

• Skf Ab

Inventors

• Ribault Patrice
• Alegre Marc

Classifications

• B25B29/02 Primary

  Bolt tensioners · CPC title

• B23P19/067 Primary

  Bolt tensioners (for hand tools B25B29/02) · CPC title

• F16B31/043

  Prestressed connections tensioned by means of liquid, grease, rubber, explosive charge, or the like (hydraulic bolt tensioners B25B29/02) · CPC title

• F16J15/06

  with solid packing compressed between sealing surfaces · CPC title