Screw tensioning device

Patent metadata

Field	Value
Publication number	US-11207767-B2
Application number	US-201615747519-A
Country	US
Kind code	B2
Filing date	Jul 15, 2016
Priority date	Jul 28, 2015
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A screw tensioning device for tensioning or loosing tensionable screw connections comprises a fixation element to be connected to a screw, a support element moveable relative to the fixation element. The support element is arranged moveable relative to the fixation element to apply tension to or remove tension from the screw. A piston is positioned and movable within the fixation element. A volume containing a hydraulic fluid is defined at least partly by the piston, the fixation element or the support element. The movement of the piston manipulates the volume and thereby moves the fixation element with respect to the support element.

First claim

The invention claimed is:

1. A screw tensioning device for tensioning or loosing tensionable screw connections comprising:
a support element,
a fixation element having an upper-end and a lower-end, the fixation element including a cylindrical recess and a first bore, the first bore formed within the fixation element and extending along a main axis of the fixation element to the cylindrical recess, the cylindrical recess disposed in the lower-end and configured to receive a screw, the fixation element disposed within and moveable relative to the support element and arranged to be moved relative to the support element to apply tension to or remove tension from the screw, and
a piston positioned within said first bore and movable within the fixation element, wherein:
the support element, the fixation element and the piston define a variable volume within the screw tensioning device;
the variable volume contains a fluid;
the variable volume comprises a piston portion and an effective portion;
the piston portion is defined by a space between the piston and the first bore formed within the fixation element;
the effective portion is defined by a space between the support element and the fixation element;
the piston portion and the effective portion are connected by one or more second bores in the fixation element that extend perpendicular to said main axis of the fixation element from the piston portion to the effective portion and provide for flow of the fluid between the piston portion and the effective portion;
the piston is configured in the first bore to provide that movement of the piston in the first bore towards the upper-end of the fixation element displaces fluid from the piston portion into the effective portion; and
the displacement of the fluid into the effective portion increases pressure in the effective portion pushing the fixation element relative to the support element in a tension creation direction to create tension in the screw without using an external hydraulic pump;
wherein the piston comprises a threaded portion that is engaged such that rotation of the piston about the main axis of movement of the piston in a first direction causes the piston to move relative to the fixation element in the first bore towards the upper-end of the fixation element to increase tension in the screw, and rotation of the piston about the main axis of movement of the piston in an opposite direction causes the piston to move relative to the fixation element in the first bore towards the lower-end of the fixation element to decrease tension in the screw.

2. The screw tensioning device of claim 1 , wherein the piston is connected to the fixation element by a threaded connection.

3. The screw tensioning device of claim 1 , wherein the piston comprises a first end and a second end and a shaft there between, and wherein the variable volume is defined by the shaft, the support element and the fixation element.

4. The screw tensioning device of claim 1 , wherein a first end of the piston comprises a sealing portion with a larger diameter than the shaft.

5. The screw tensioning device of claim 1 , wherein the fixation element is housed at least partly in the support element.

6. The screw tensioning device of claim 1 , wherein a base area of the piston portion is smaller than a base area of the effective portion.

7. The screw tensioning device of claim 1 further comprising a sealing element between the fixation element and the piston configured to seal the variable volume in a direction of a second end of the piston.

8. The screw tensioning device of claim 1 further comprising a sealing element between the fixation element and the support element configured to seal the variable volume.

9. The screw tensioning device of claim 1 , wherein a main axis of movement of the piston is parallel to a main axis of the screw.

10. A method for manipulating tension within a screw connection, comprising:
positioning a support element on a component to be connected by the screw connection, wherein:
the support element has a fixation element disposed within and moveable relative to the support element and arranged to be moved relative to the support element to apply tension to or remove tension from a screw of the screw connection, the fixation element having an upper-end and a lower-end, the fixation element comprising a cylindrical recess and a first bore, the first bore formed within the fixation element and extending along a main axis of the fixation element to the cylindrical recess, the cylindrical recess disposed in the lower-end and configured to receive the screw,
a piston is positioned within said first bore and movable relative to the fixation element,
the support element, the fixation element and the piston define a variable volume within the screw tensioning device; and
the variable volume contains a fluid,

connecting the fixation element to the screw to which tension is to be applied or removed,
moving linearly the fixation element in respect to the support element by moving the piston relative to the fixation element in the first bore in the fixation element, wherein:
the piston is moved in a direction in the first bore that causes the fluid contained in the variable volume to be displaced from a piston portion defined by the first bore of the fixation element and the piston into an effective portion defined by the support element and the fixation element;
the piston portion and the effective portion are connected by one or more second bores in the fixation element that extend perpendicular to said main axis, thereby providing fluid communication from the piston portion to the effective portion, and wherein moving linearly the fixation element in respect to the support element comprises linearly moving the piston and increasing a pressure of the fluid in the effective portion by forcing the fluid through the second bore into the effective portion and pushing the fixation element relative to the support element in a tension creation direction to create tension in the screw without using an external hydraulic pump;
wherein the piston comprises a threaded portion that is engaged such that rotation of the piston about the main axis of movement in a first direction causes the piston to move relative to the fixation element in the first bore towards the upper-end of the fixation element to increase tension in the screw, and rotation of the piston about the main axis of movement of the piston in an opposite direction causes the piston to move relative to the fixation element in the first bore towards the lower-end of the fixation element to decrease tension in the screw.

11. The method of claim 10 , wherein the variable volume comprises the piston portion and the effective portion.

Assignees

• Caterpillar Energy Solutions Gmbh

Inventors

• Guisasola Inigo

Classifications

• B25B29/02 Primary

  Bolt tensioners · 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

• B23P19/067

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