GB2562096A

GB2562096A - Screw tensioning device

Info

Publication number: GB2562096A
Application number: GB1707167.1A
Authority: GB
Inventors: Guisasola Inigo
Original assignee: Caterpillar Energy Solutions GmbH
Current assignee: Caterpillar Energy Solutions GmbH
Priority date: 2017-05-05
Filing date: 2017-05-05
Publication date: 2018-11-07
Also published as: GB201707167D0; DE102018110517A1

Abstract

Disclosed is a screw tensioning device suitable for tensioning or loosening multiple fasteners. The device includes a body member 26 defining a first cylindrical bore 36 and a second cylindrical bore 40 fluidly connected to the first cylindrical bore. The device also includes a first fixation element 52 movably positioned in the first cylindrical bore to define a first variable volume 54, and a second fixation element 90 movably positioned in the second cylindrical bore to define a second variable volume 92. The fixation elements comprise a plug end adapted to be threadably connected to the fasteners to be tensioned. The screw tensioning device further includes a piston 76 supported within the body member, movable between first and second positions. Movement of the piston between the first and second positions manipulates the first and second variable volume to selectively apply or release force on a first fastener connected to the first fixation element and a second fastener connected to the second fixation element. The second fixation elements may include a plurality of fixation elements positioned within a plurality of cylindrical bores.

Description

(54) Title of the Invention: Screw tensioning device

Abstract Title: Screw tensioning device for multiple fasteners (57) Disclosed is a screw tensioning device suitable for tensioning or loosening multiple fasteners. The device includes a body member 26 defining a first cylindrical bore 36 and a second cylindrical bore 40 fluidly connected to the first cylindrical bore. The device also includes a first fixation element 52 movably positioned in the first cylindrical bore to define a first variable volume 54, and a second fixation element 90 movably positioned in the second cylindrical bore to define a second variable volume 92. The fixation elements comprise a plug end adapted to be threadably connected to the fasteners to be tensioned. The screw tensioning device further includes a piston 76 supported within the body member, movable between first and second positions. Movement of the piston between the first and second positions manipulates the first and second variable volume to selectively apply or release force on a first fastener connected to the first fixation element and a second fastener connected to the second fixation element.

The second fixation elements may include a plurality of fixation elements positioned within a plurality of cylindrical bores.

⁵⁶ PJj] _QA on 136

FIG. 2

1/6

FIG. 1

2/6

FIG. 2

3/6

4/6

100

FIG. 4

5/6

106

FIG. 5

6/6

FIG. 6

-1SCREW TENSIONING DEVICE

Technical Field

The present disclosure relates to coupling of components of a machine, and more particularly to a screw tensioning device for tensioning or loosening fasteners used for coupling the components.

Background

In various applications, two or more machine components are coupled together to form an assembly. Often, the two or more machine components are coupled together using fasteners. The fasteners, such as screws, studs, rods, and bolts, are inserted through holes of the machine components and are further tightened using nuts. These fasteners are also preloaded under a predetermined tension, after insertion through the holes and prior to tightening using nuts, to firmly secure the assembly of the components.

Typically, screw tensioning devices are used to preload the fasteners under the predetermined tension. In particular, a screw tensioning device is connected to a fastener to apply the predetermined tension on the fastener and thereafter, a nut is tightened to the fastener to maintain the fastener under the predetermined tension. In cases of multiple fastener connections, separate screw tensioning device is connected to each fastener to apply the predetermined tension on each individual fastener. However, connecting the separate screw tensioning devices with each of the fasteners in multiple fastener connections may be cumbersome and time consuming. Moreover, each of the fasteners may not be equally subjected to the predetermined tension when separate screw tensioning devices are used.

JP Publication Number 2010/155288 (the ’288 publication) discloses a bolt tensioner. The bolt tensioner includes an annular jig openable along a circumferential direction and a plurality of cylinder chambers arranged along the circumferential direction. The bolt tensioner also includes a common passage which supplies a hydraulic pressure to the cylinder chambers at the same time

-2and a plurality of pistons. The bolt tensioner further includes a plurality of corresponding bolt connecting parts connected to a plurality of bolts, a plurality of corresponding piston connecting parts, and a plurality of reaction receiving members for receiving a reaction from a flange. Connecting structures are also formed between the corresponding bolt connecting parts and the corresponding piston connecting parts for engaging the pistons with the bolts, so as to be disengaged along an axial direction in accordance with a relative positional movement between the bolt connecting parts and the piston connecting parts. However, the bolt tensioner, as disclosed in the’28 8 publication, requires an external source of hydraulic pressure for actuating the plurality of pistons to tension the bolts.

Summary of the Disclosure

In one aspect of the present disclosure, a screw tensioning device for tensioning or loosening multiple fasteners is provided. The screw tensioning device includes a body member defining a first cylindrical bore and a second cylindrical bore fluidly connected to the first cylindrical bore. The screw tensioning device also includes a first fixation element movably positioned in the first cylindrical bore of the body member to define a first variable volume. The first fixation element includes a plug end adapted to be threadably connected to a first fastener of the multiple fasteners. The screw tensioning device also includes a second fixation element movably positioned in the second cylindrical bore of the body member to define a second variable volume. The second fixation element includes a plug end adapted to be threadably connected to a second fastener of the multiple fasteners. The screw tensioning device further includes a piston supported within the body member and movable between a first position and a second position. Movement of the piston between the first position and the second position manipulates the first variable volume and the second variable volume to selectively apply and release force on the first fastener connected to the first fixation element and the second fastener connected to the second fixation element.

-3Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

Brief Description of the Drawings

FIG. 1 is a diagrammatic perspective view of a screw tensioning device, according to an embodiment of the present disclosure;

FIG. 2 is a diagrammatic sectional view of the screw tensioning device taken along a line A-A’ in FIG. 1;

FIG. 3 is a diagrammatic perspective view of a screw tensioning device, according to another embodiment of the present disclosure;

FIG. 4 is a diagrammatic sectional view of the screw tensioning device taken along a line B-B’ in FIG. 3;

FIG. 5 is a diagrammatic sectional view of a portion of the screw tensioning device taken along a line C-C’ in FIG. 3; and

FIG. 6 is a diagrammatic sectional view of the screw tensioning device taken along a line D-D’ in FIG. 3.

Detailed Description

Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts.

FIG. 1 and FIG. 2 illustrate different views of a screw tensioning device 10 for tensioning or loosening multiple fasteners 12. The screw tensioning device 10 may be used to preload or untighten the multiple fasteners 12 (shown in FIG. 2) by tensioning or loosening the multiple fasteners 12. The fasteners 12 may be any tensionable connection device, such as a screw, a bolt, a rod, a stud, etc., that may be stretched by applying force and is able to store an amount of elastic energy. In the present embodiment, the fasteners 12, as shown in FIG. 2, are screws, each of which includes a first end 14 adapted to be threadably fixed to a

-4first component 16, a second end 18 opposite to the first end 14 and extending out of a second component 20, and an elastic part 22 that is positioned between the first end 14 and the second end 18 and that may be stretched by applying force on the second component 20.

As shown in FIG. 2, the fasteners 12 couple the first component 16 to the second component 20 using multiple nuts 24. Specifically, to couple the first component 16 to the second component 20, each of the fasteners 12 are fixed to internal threads of the first component 16 and a nut of the multiple nuts 24 may threadably coupled to a respective fastener 12 to hold the fastener 12. In an example, the first component 16 may be a crank case and the second component 20 may be a turbo charger mount.

Referring again to FIGS. 1 and 2, the screw tensioning device 10 of the present disclosure is used to couple or uncouple the first component 16 and the second component 20 by tensioning or loosening the multiple fasteners 12. The screw tensioning device 10 includes a body member 26. In an example, the body member 26 includes a first cylindrical portion 32, which forms an upper part of the body member 26, and a plurality of second cylindrical portions 34 extending outwardly from the first cylindrical portion 32. The plurality of second cylindrical portions 34 forms a lower part of the body member 26 and is adapted to be positioned on the second component 20. Each of the plurality of second cylindrical portions 34 is positioned on the second component 20 such that each second cylindrical portion 34 surrounds a fastener 12 of the multiple fasteners 12.

The body member 26 further defines a first cylindrical bore 36 and a plurality of second cylindrical bores 40 (two cylindrical bores are shown in FIG. 2). The first cylindrical bore 36 extends through the first cylindrical portion 32 and the plurality of second cylindrical bores 40 extend through the plurality of second cylindrical portions 34. In one embodiment, the first cylindrical bore 36, as

-5shown, may be positioned at a center of the body member 26 and the plurality of second cylindrical bores 40 may be arranged equally spaced from each other along a circle concentric with the center of the body member 26. Further, as shown in FIG. 2, the first cylindrical bore 36 may include a first wider portion 28 and a first narrow portion 38 such that the first cylindrical bore 36 forms a stepped bore, and each of the plurality of second cylindrical bores 40 may include a second wider portion 42 and a second narrow portion 44 such that each of the second cylindrical bores 40 forms a stepped bore.

The body member 26 may also define one or more channels 46 that fluidly connect the first cylindrical bore 36 to each of the second cylindrical bores 40. The channels 46 may extend radially outward from the first narrow portion 38 of the first cylindrical bore 36 to the second narrow portions 44 of the second cylindrical bores 40. In one embodiment, the channels 46, as shown, may be defined in walls 50 of the body member 26 and may allow a flow of hydraulic fluid from the first cylindrical bore 36 to each second cylindrical bores 40.

The screw tensioning device 10 further includes a first fixation element 52 movably positioned within the first cylindrical bore 36. The first fixation element 52 along with the body member 26 partly defines a first variable volume 54. In an example, the first fixation element 52 is movable along the first cylindrical bore 36 based on displacement of hydraulic fluid from the first variable volume 54.

The first fixation element 52 includes a first head end 56, and a first plug end 58 opposite to the first head end 56. The first head end 56 is positioned within the first wider portion 28 of the first cylindrical bore 36 to partly define an effective portion 60 of the first variable volume 54. The first head end 56 includes a vent opening (not shown) closed by a screw 64. The vent opening is in fluid connection with the effective portion 60 of the first variable volume 54 to

-6selectively allow removal of gases and/or air from the effective portion 60 of the first variable volume 54. The first head end 56 further includes a groove (not shown) extending along a perimeter thereof to receive a sealing member 68. The sealing member 68 seals the hydraulic fluid within the effective portion 60 of the first variable volume 54.

The first plug end 58 of the first fixation element 52 may be positioned within the first narrow portion 38 of the first cylindrical bore 36. The first plug end 58 is connectable to a first fastener 70 of the multiple fasteners 12. Specifically, at the first plug end 58, the first fixation element 52 includes a recess 72 that houses the first end 14 of the first fastener 70. At the first plug end 58, the first fixation element 52 also includes internal threads (not shown). The internal threads engage with threads of the second end 18 of the first fastener 70 to couple the first fastener 70 with the first fixation element 52, while the first end 14 of the first fastener 70 threadably engages with the first component 16. Hence, due to such a coupling of the first fastener 70, movement of the first fixation element 52 in the first cylindrical bore 36 applies tension or removes tension from the fasteners 12 to preload or untighten the first fastener 70. In particular, movement of the first fixation element 52 away from the second component 20 in the first cylindrical bore 36 applies force on the first fastener 70 to tension the first fastener 70. Further, movement of the first fixation element 52 towards from the second component 20 in the first cylindrical bore 36 releases force on the first fastener 70 to remove tension in the first fastener 70.

As shown in FIG. 2, the first fixation element 52 includes a bore 74 extending from the first head end 56 to the recess 72. The bore 74 has a diameter less than a diameter of the recess 72 and a diameter of the first wider portion 28 of the first cylindrical bore 36. The bore 74 is adapted to slidably receive a piston 76 therein to form a piston portion 78 of the first variable volume 54. In an example, the piston portion 78 and the effective portion 60 together form the first variable volume 54. The first fixation element 52 further includes one or more openings

-780 extending radially outwards from the bore 74 to the first wider portion 28 of the first cylindrical bore 36. The openings 80 allow a flow of hydraulic fluid from the bore 74 into the effective portion 60 of the first variabfe vofume 54 formed between the first fixation element 52 and the body member 26.

In particular, the piston portion 78 and the effective portion 60 are fluidly connected to each other through the openings 80 such that hydraulic fluid disposed within the first variable volume 54 may move back and forth between the piston portion 78 and the effective portion 60 through the openings 80. Further, to keep hydraulic fluid from leaking from the first variable volume 54 when hydraulic fluid flows from the piston portion 78 to the effective portion 60, the screw tensioning device 10 includes a first O-ring 82 and a second O-ring 84 disposed in a first groove (not shown) of the piston 76 and a second groove (not shown) of the first fixation element 52, respectively.

In one embodiment, the piston 76 is movable within the bore 74 between a first position and a second position to displace the hydraulic fluid between from the piston portion 78 to the effective portion 60, and vice versa. To move the piston 76 between the first position and the second position, a cap member 66 is coupled to the piston 76. The cap member 66 is adapted to engage with an external device (not shown), such as a wrench, that is adapted to rotate the cap member 66 to cause movement of the piston 76 between the first position and the second position. In an example, the cap member 66 is threadably coupled to the piston 76. Alternatively, the cap member 66 may be press-fitted to the piston 76 or an integral portion of the piston 76.

The movement of the piston 76 between the first position and the second position manipulates the first variable volume 54. In particular, when the piston 76 is moved in an upward direction from the second position (shown in FIG. 2) to the first position at which volume of the piston 76 portion is minimum, hydraulic

-8fluid displaces out of the piston portion 78 into the effective portion 60 through the openings 80. This increases a pressure within the effective portion 60 to move the first fixation element 52 in a direction away from the first fastener 70. The movement of the first fixation element 52 away from the first fastener 70 applies force on the first fastener 70 to be stretched or tensioned.

Thereafter, i.e. after the hydraulic fluid flows into the effective portion 60, the hydraulic fluid displaces from the effective portion 60 into the plurality of second cylindrical bores 40, through the channels 46, for tensioning or loosening second fasteners 88 of the multiple fasteners 12. In FIG. 2, only two second fasteners 88 are illustrated. Each of the second fasteners 88 includes the first end 14 adapted to be threadably connected to the first component 16, and the second end 18 extending out of the second component 20.

As shown in FIGS. 1 and 2, the screw tensioning device 10 includes a plurality of second fixation elements 90 that engages with the second ends 18 of the second fasteners 88. The plurality of second fixation elements 90 is positioned in the second cylindrical bores 40 of the body member 26 and movable along the second cylindrical bore 40 for tensioning or loosening the second fasteners 88. Although in FIG. 1 six second fixation elements 90 are shown, a number of the second fixation elements 90 may be greater than or less than six, depending upon a number of the fasteners 12 to be tensioned or loosened.

Referring to FIG. 2, only two second fixation elements 90 are illustrated. For explanation purposes, the plurality of second fixation elements 90 are described with reference only to one second fixation element. However, it is understood that description provided herein is equally applicable to other second fixation elements, without departing from the scope of present disclosure.

--9-The second fixation element 90 defines a second variable volume 92 in fluid communication with the first variable volume 54. In an example, the second variable volume 92 is defined by the space between the second fixation element 90 and the body member 26. In an example, the second fixation element 90 is movable along the second cylindrical bore 40 based on displacement of hydraulic fluid between the first variable volume 54 and the second variable volume 92.

As shown in FIG. 2, the second fixation element 90 includes a second head end 94, and a second plug end 96 opposite to the second head end 94. The second head end 94 is positioned within the second wider portion 42 of the second cylindrical bore 40 and adapted to partly define the second variable volume 92. The second head end 94 includes a groove (not shown) extending along a perimeter thereof for receiving a sealing member 86. The sealing member 86 seals the hydraulic fluid within the second variable volume 92.

The second plug end 96 is positioned within the second narrow portion 44 of the second cylindrical bore 40 and connectable to a second fastener 88 of the multiple fasteners 12. Specifically, at the second plug end 96, the second fixation element 90 includes a recess 97 that houses the first end 14 of the second fastener 88. At the second plug end 96, the second fixation element 90 also includes internal threads (not shown). The internal threads of the second fixation element 90 engage with threads of the second end 18 of the second fastener 88 to couple the second fastener 88 with the second fixation element 90, while the first end 14 of the second fastener 88 is threadably engaged with the first component 16. Hence, due to such a coupling of the second fastener 88, movement of the second fixation element 90 along the second cylindrical bore 40 applies tension or removes tension in the second fastener 88 to preload or untighten the second fastener 88. In particular, movement of the second fixation element 90 away from the second component 20 in the second cylindrical bore 40 applies force on the second fastener 88 to preload the second fastener 88. Further, movement of

-10the second fixation element 90 towards the second component 20 in the second cylindrical bore 40 removes force on the second fastener 88.

In an embodiment, the multiple fasteners 12 may be subjected to a predetermined tension. The predetermined tension may be determined based on a pressure of the hydraulic fluid in at least one of the first variable volume 54 and the second variable volume 92. In an example, to determine the pressure of hydraulic fluid in the first variable volume 54 and the second variable volume 92, the second variable volume 92 may be fluidly connected to a pressure metering device 98. The pressure metering device 98 may include, but not limited to, a manometer.

FIG. 3 and FIG. 4 illustrate different views of a screw tensioning device 100 for tensioning or loosening multiple fasteners 102, according to another embodiment of the present disclosure. The screw tensioning device 100 is used to preload or untighten four fasteners 102. Only two fasteners 102 are shown in FIG. 4. The fasteners 102 are adapted to couple a first component 104 to a second component 106 using four nuts 108 (shown in FIG. 4). In an example, the first component 104 is a connecting rod and the second component 106 is a connecting rod cap. The screw tensioning device 100 of the present disclosure is used to stretch the multiple fasteners 102 such that a nut 108 may be tightened or loosened to preload or untighten the respective fastener 102.

In the present embodiment, the screw tensioning device 100 includes a body member 110, a first fixation element 112, and three second fixation elements 114, individually indicated as 114-1, 114-2 and 114-3. The body member 110 includes an elongated portion 116 and four cylindrical portions 118, individually referred to as a first cylindrical portion 118-1, a second cylindrical portion 118-2, a third cylindrical portion 118-3, and a fourth cylindrical portion 118-4.

-11The elongated portion 116 is adapted to be disposed along a length of the second component 106. Further, each of the first cylindrical portion 118-1, the second cylindrical portion 118-2, the third cylindrical portion 118-3, and the fourth cylindrical portion 118-4 is adapted to be positioned on the second component 106 such that each cylindrical portion 118 surrounds a fastener 102 of the multiple fasteners 102. In an example, each of the first cylindrical portion 118-1, the second cylindrical portion 118-2, the third cylindrical portion 118-3, and the fourth cylindrical portion 118-4 extends orthogonally from the elongated portion 116. In one embodiment, the elongated portion 116 is a closed cuboidal shaped member having a front face 120, a rear face 122 (shown in FIG. 4) opposite to the front face 120 and a plurality of side faces 124 extending between the front face 120 and the rear face 122.

As shown in FIG. 3, the body member 110 further defines a first cylindrical bore 126 and a plurality of second cylindrical bores 128, individually indicated by numerals 128-1, 128-2, and 128-3. In one embodiment, the first cylindrical bore 126 is formed in the first cylindrical portion 118-1. Further, the second cylindrical bores 128-1, 128-2, and 128-3 are formed in the second cylindrical portions 118-2, the third cylindrical portion 118-3, and the fourth cylindrical portion 118-4, respectively.

The first cylindrical bore 126 is adapted to receive the first fixation element 112. Further, the first cylindrical bores 128-1, the second cylindrical bore 128-2, and the third cylindrical bore 128-3 are configured to individually receive the second fixation elements 114-1, 114-2, and 114-3, respectively.

Referring now to FIG. 5, a sectional view of the screw tensioning device 100 showing the first fixation element 112 and the second fixation element 114-2 is illustrated. As shown in FIG. 5, the first fixation element 112 is movably positioned within the first cylindrical bore 126 to define a first variable volume

-12138. In one embodiment, the first variable volume 138 includes an effective portion 141 defined by the closed space between the first fixation element 112 and the body member 110 and a piston portion 186 (shown in FIG. 6), which is explained in detail with reference to FIG. 6. The first variable volume 138 may store hydraulic fluid therein. The hydraulic fluid displaces forth and back between the effective portion 141 and the piston portion 186 to cause movement of the first fixation element 112 within the first cylindrical bore 126.

In an example, the first fixation element 112 may include a first head end 140, and a first plug end 142 opposite to the first head end 140. The first head end 140 may include a vent opening (not shown) in fluid connection with the first variable volume 138. The vent opening is adapted to be closed by a screw 144 to selectively allow removal of gases from the first variable volume 138. The first head end 140 also includes a groove (not shown) extending along a circumference thereof. The groove receives a sealing member 146 to seal the hydraulic fluid within the first variable volume 138.

Further, the first plug end 142 may be connectable to a first fastener 150 of the multiple fasteners 102. Specifically, at the first plug end 142, the first fixation element 112 may include a recess 148 that houses a second end 152 of the first fastener 102-1. At the first plug end 142, the first fixation element 112 also include internal threads (not shown) that engage with the second end 152 of the first fastener 102-1 to couple the first fastener 150 with the first fixation element 112, while a first end 154 (shown in FIG. 4) of the first fastener 150 engages with the first component 104.

Due to such a coupling of the first fastener 150, movement of the first fixation element 112 in the first cylindrical bore 126 applies tension or removes tension from the first fastener 150 to preload or untighten the first fastener 150. In particular, a movement of the first fixation element 112 away from the second

-13component 106 applies force on the first fastener 150 to preload the first fastener 150. Further, a movement of the first fixation element 112 towards from the second component 106 releases force on the first fastener 150.

Referring again to FIG. 5, one second fixation element, i.e. the second fixation element 114-1 is shown. For explanation purposes, one second fixation element, i.e. the second fixation element 114-1 is described herein below. It is understood that description of the second fixation element 114-1 is equally applicable to other second fixation elements 114-2 and 114-3, without departing from the scope of the present disclosure. The second fixation element 114-1 is movably positioned within the second cylindrical bore 118-2 to define a second variable volume 155. In an example, the second variable volume 155 is defined by the closed space between the second fixation element 114-1 and the second cylindrical bore 118-2. In one embodiment, the second fixation element 114-1 may be movable within the second cylindrical bore 118-2, based on displacement of hydraulic fluid from the second variable volume 155.

The second fixation element 114-1 includes a second head end 156, and a second plug end 158 opposite to the second head end 156. The second head end 156 includes a groove (not shown) extending along a circumference thereof to receive a sealing member 162, for example an O-ring. The sealing member 162 seals the hydraulic fluid within the second variable volume 155.

The second plug end 158 is connectable to a second fastener 164 of the multiple fasteners 102. Specifically, at the second plug end 158, the second fixation element 114-1 includes a recess 166 that houses a second end 168 of the second fastener 164. At the second plug end 158, the second fixation element 114-1 also includes internal threads (not shown) that engage with threads of the second end 168 of the second fastener 164, to couple the second fastener 164 with the second fixation element 114-1, while a first end (not shown) of the second fastener 164

-14engages with the first component 104. Due to such a coupling of the second fastener 164, movement of the second fixation element 114-1 within the second cylindrical bore 128-1 applies or removes force on the second fastener 164 to preload or untighten the second fastener 164.

FIG. 6 illustrates a diagrammatic sectional view of the screw tensioning device 100 taken along a line D-D’ in FIG. 3. The screw tensioning device 100 further includes a bore 172 defined within the elongated portion 116 of the body member 110. In an embodiment, the bore 172 is defined along a central axis of the body member 110 such that the bore 172 opens on the front face 120 of the elongated portion 116. The bore 172 includes a wide portion 174 and a narrow section 176 such that the bore 172 forms a stepped opening. The bore 172 is in fluid communication with the first variable volume 138. In an example, to fluidly connect the bore 172 to the first variable volume 138, the screw tensioning device 100 includes a channel 178 extending along a length of the elongated portion 116.

The screw tensioning device 100 further includes a piston 180 supported within the body member 110. The piston 180 includes a first end 182 and a second end 184 distal to the first end 182. In the present embodiment, the piston 180 is positioned within the bore 172 of the body member 110 such that the piston portion 186 of the first variable volume 138 is formed. Specifically, the piston portion 186 is formed between the second end 184 of the body member 110 and the piston 180.

The piston 180 may be movable between a first position and a second position within the bore 172 to displace the hydraulic fluid between the piston portion 186 and the effective portion 141 of the first variable volume 138. At the first position, the first end 182 of the piston 180 may be disposed at the narrow section 176 of the bore 172. Conversely, at the second position, the first end 182 of the piston 180 may be disposed at the front face 120 of the elongated portion 116.

-15Referring now to FIGS. 5 and 6, movement of the piston 180 between the first position and the second positon manipulates the first variable volume 138 and the second variable volume 155. In particular, when the piston 180 moves from the first position to the second position, hydraulic fluid disposed in the piston portion 186 displaces into the effective portion 141. This causes movement of the first fixation element 112 away from the first fastener 150. The movement of the first fixation element 112 away from the first fastener 150 causes the first fastener 150 to be stretched or tensioned. Simultaneously, i.e. after the hydraulic fluid is pushed into the effective portion 141, hydraulic fluid flows from the first variable volume 138 into the second variable volume 155 through an opening 188. This increases a pressure within the second variable volume 155, which in turn, moves the second fixation element 114-1 away from the second component 106. The movement of the second fixation element 114-1 away from the second component 106 causes the second fastener 164 to be stretched or tensioned.

In an embodiment, each of the multiple fasteners 102 may be subjected to a predetermined tension. The predetermined tension may be determined based on a pressure of the hydraulic fluid in at least one of the first variable volume 138 and the second variable volume 155. In an example, to determine the pressure of hydraulic fluid in the first variable volume 138 and the second variable volume 155, the first variable volume 138 is fluidly connected to a pressure metering device 190.

Industrial Applicability

The present disclosure relates to the screw tensioning devices 10, 100 that may be used to couple or uncouple the first component 16, 104, for example a crank case, to the second component 20, 106, for example a turbo charger mount. To couple the first component 16, 104 to the second component 20, 106, the second component 20, 106 is positioned next to the first component 16, 104 and the

-16fasteners 12, 102 are inserted into the second component 20, 106 and connected to the first component 16, 104 by a threaded connection. The fasteners 12, 102 extend out from the second component 20, 106 to the first component 16, 104 and the nuts 24, 108 are tightened to the fastener 12, 102.

As mentioned earlier, the first fixation element 52, 112 is movably positioned in the first cylindrical bore 36, 126 of the body member 26, 110 and is connectable to the second end 18, 152 of the first fastener 70, 150 by the threaded engagement. To create a tension in the first fastener 70, 150, the piston 76, 180 mounted in the first fixation element 52, 112 is moved away from the second component 20, 106, for example by turning the piston 76, 180 using the cap member 66 and the external device. By moving the piston 76, 180, the piston portion 78, 186 of the first variable volume 54 decreases and the hydraulic fluid is pushed from the piston portion 78, 186 to the effective portion 60, 141. Therefore, the effective portion 60, 141 increases in volume as the hydraulic fluid is displaced into the effective portion 60, 141. Consequently, the first fixation element 52, 112 is moved along the first cylinder bore 36, 126 to stretch the first fastener 70, 150 into a predetermined tension. Thereafter, to retain the first fastener 70, 150 in the predetermined tension, the nut 24, 108 is tightened on the first fastener 70, 150. The nut 24, 108 may be tightened using a tool, such as a wrench, which may be inserted through openings (not shown) of the body member 26, 110.

Simultaneously, the hydraulic fluid flows from the first variable volume 54 into the second variable volumes 92. This increases a pressure in the second variable volume 92, which in turn causes the second fixation element 90, 114 to move away from the second component 20, 106. Consequently, the second fasteners 88, 164 are stretched into a predetermined tension.

-17The screw tensioning device 10, 100 may also be used to loosen the multiple fasteners 12, 102. For example, to loosen the first fastener 70, 150 and the second fastener 88, 164, the first fixation element 52, 112 and the second fixation element 90, 114 are positioned around and coupled to the first fastener 70, 150 and the second fastener 88, 164 respectively.

The piston 76, 180 is further moved between the first position and the second position to displace the hydraulic fluid from the piston portion 78, 186 to the effective portion 60, 141. As described earlier, the movement of the piston 76, 180 increases the pressure in the effective portion 60, 141 and thus, in the second variable volume 92. This causes the first fixation element 52, 112 and the second fixation elements 90, 114 to stretch the first fastener 70, 150 and the second fasteners 88, 164, simultaneously. Thereafter, the nuts 24 are loosened using a tool, such as a wrench which may be received through openings formed in cylindrical portions, such as the second cylindrical portions 34, and the cylindrical portions 118 of the body member 26, 110, respectively. After loosening the nut 24, 108, the piston 76, 180 is moved towards the second component 20, 106 to release the tension in the first fastener 70, 150 and the second fasteners 88, 164. Therefore, the screw tensioning device 10, 100 of the present disclosure offers a comprehensive approach for tensioning or loosening multiple fasteners 12, 102 simultaneously.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

--18-Global Claim Set

Claims

What is claimed is:

1. A screw tensioning device (10, 100) for tensioning or loosening multiple fasteners (12, 102), the screw tensioning device (10, 100) comprising:

a body member (26, 110) defining a first cylindrical bore (36, 126) and a second cylindrical bore (40, 128) fluidly connected to the first cylindrical bore (36, 126);

a first fixation element (52, 112) movably positioned in the first cylindrical bore (36, 126) of the body member (26, 110) to define a first variable volume (54, 138), the first fixation element (52, 112) having a plug end (58, 142) adapted to be threadably connected to a first fastener (70, 150) of the multiple fasteners (12, 102);

a second fixation element (90, 114) movably positioned in the second cylindrical bore (40, 128) of the body member (26, 110) to define a second variable volume (92, 155), the second fixation element (90, 114) having a plug end (96, 158) adapted to be threadably connected to a second fastener (88, 164) of the multiple fasteners (12, 102); and a piston (76, 180) supported within the body member (26, 110) and movable between a first position and a second position, wherein movement of the piston (76, 180) between the first position and the second position manipulates the first variable volume (54, 138) and the second variable volume (92, 155) to selectively apply and release force on the first fastener (70, 150) connected to the first fixation element (52, 112) and the second fastener (88, 164) connected to the second fixation element (90, 114).

2. The screw tensioning device (10, 100) of claim 1, wherein the second fixation element (90, 114) includes a plurality of fixation elements (90, 114) movably positioned within a plurality of cylindrical bores (40, 128) to collectively define a variable volume (92, 155), the plurality of fixation elements (90, 114) being

-19adapted to be threadably connected to a plurality of second fasteners (88, 164) of the multiple fasteners (12, 102).

Intellectual

Property

Office

Application No: Claims searched:

GB 1707167.1 1-2