TECHNICAL FIELD The present invention concerns a method for the loosening of bolt or nut from a bolt joint, or for the provision of an abutment force on the distal end of the bolt joint in the application or tightening of the bolt joint.

BACKGROUND When bolt joints have been tightened for a longer time they may be difficult to loosen using usual tools. Thus, there is a problem to loosen bolt joints when they have been tightened a longer time and especially when they have rusted in or got stuck in another way.

Normally, various different tools and/or methods are used for trying to loosen the screw or the nut of the bolt joint from the attached place. Examples of tools and methods which may be used in the loosening of the bolt joint are that holes are drilled in the screw and a so-called "easy out", which is a form of screw extractor, is screwed-in. Furthermore, a nut may be welded onto the attached screw and then it is tried to be loosened using a socket wrench, universal pliers, or the like tools, or it may be tried to loosen the bolt joint by heat and/or by rust-removing agent.

All methods may be cumbersome to use and there is risk of the bolt joint being broken apart. Often these tools or methods neither work satisfactory. SUMMARY

Therefore, the main object of the present invention is primarily to find a method, which, among other things, solves the above-mentioned problems easily and efficiently and which works in a satisfactory way. The object of the invention is achieved by a method for loosening as well as tool according to what is defined in the independent claims. The dependent claims further define developments of the method as well as the tool.

The method according to the present invention is essentially characterized in that an at least three-part tool is utilized, which comprises movably actuatable locking and wedge elements as well as a central turnable frame part and turnable locking sleeve surrounding the same as well as turnable outside sleeve, which frame part and which turnable sleeves are provided with threads, the tool being actuated by torsional force whereby pressing, clamping, as well as pulling force are provided for the unscrewing or tightening of the bolt or the nut at the bolt joint in question. The locking sleeve situated internally in the tool is actuated to be screwed clockwise after the tool has been placed to surround the bolt head or the nut, the surrounding outside sleeve after that being screwed also in the clockwise direction to provide a lifting force, whereupon the frame part situated internally in the tool is actuated to be turned in the counter- clockwise direction, until the bolt joint comes loose or for the clamping of the same when the opposite end thereof is being attached, or the locking sleeve situated internally in the tool being actuated to be screwed counter-clockwise after the tool has been placed to surround the bolt head or the nut, the surrounding outside sleeve after that being screwed also in the counter- clockwise direction to provide a lifting force, whereupon the frame part situated internally in the tool is actuated to be turned in the clockwise direction, until the bolt joint comes loose or for the clamping of the same when the opposite end thereof is being attached.

The invention also concerns a tool for carrying out a method for the loosening of bolt or nut from bolt joints or for the provision of abutment force to the distal end of bolt joints in the application of bolt joints according to the invention. In addition to above-mentioned prior art, there are problems when it is desired to apply bolt joints in narrow places, such as in boats and in other places and where someone is needed to make resistance when tightening from the opposite end of the bolt joint. If necessary, it is possible to saw a gash in the end of the screw and make resistance internally in the nut using a screwdriver from the same side as the nut is tightened on the screw.

Thus, an additional main object of the present invention is to solve the problem of a working tool in a reliable and economic way.

Said additional object is achieved by a tool according to the present invention. The tool comprises at least three parts extending along a common axial centre axis, a locking sleeve and an outside sleeve, which pair wise surround a central frame part, of which are provided with co-operating threads, as well as that also the central frame part has threads co-operating with the surrounding adjacent locking sleeve. A number of locking and wedge elements are carried by the tool, whereby the threads allow the parts to be displaced in relation to each other so that torsional force on the tool provides pressing, clamping, as well as pulling force.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is described below in the form of a preferred embodiment example, reference being made to the accompanying drawings.

Figure 1 schematically shows a picture of a tool and which forces that act due to the action of the tool on a bolt joint,

Figures 2-3 schematically show in steps in perspective the use of the tool, Figure 4 schematically shows lined up examples of parts which may be included in the tool as seen in perspective obliquely from the front, Figures 5-6 schematically show the tool in section view in inactive loosening position I and in active loosening position II, respectively,

Figure 7 schematically shows in perspective, obliquely from above, a central frame part,

Figure 8 schematically shows a spring bracket of a spring means for a locking and wedge element,

Figure 9 schematically shows a perspective view of the locking and wedge element with spring means in active mounting position,

Figure 10 schematically shows a perspective view of the application of the tool to a bolt joint,

Figure 1 1 schematically shows a section view of the tool and the bolt joint in an active loosening position, and

Figure 12 schematically shows a perspective view of the application of the tool to a bolt joint.

DESCRIPTION OF EMBODIMENT EXAMPLES

Different aspects of the invention are illustrated below together with the appurtenant drawings for describing embodiment examples.

In Figures 1-3, a tool 4 is shown according to the present invention, wherein the tool 4 can be coupled together with a levered turning tool 30. The turning tool 30 may be of conventional kind, such as, for instance, a ratchet wrench, socket wrench, spanner, or the like. By the levered turning tool 30, which is coupled together with the tool 4 according to the present invention for easily and efficiently provide the loosening of a bolt 31 or a nut 32 from a bolt joint 33 or for the provision of an abutment force to the distal end 33B of the bolt joint in the application of the bolt joint 33, see Figures 10-1 1 , the tool 4 is readily actuated by a turning motion of the turning tool 30. As shown in Figures 5-6, the bolt joint 33 is running through an object, wherein the nut 32 is positioned on one side of the object and a bolt head 34 arranged on the bolt 31 is positioned on the other side of the object. One or the other side of the object forms a backing 35, against which the tool 4 abuts when it is applied in relation to the nut 32 or the bolt head 34.

In the invention, examples are shown only for usually used right-threaded bolt joints and screw joints, but should the invention be used for left-threaded bolt joints and screw joints, it is required that threads and turning directions are opposite those described below and shown in the drawings. According to the invention, a method is executed by manually using the tool 4, which at least is three-part. The tool 4 comprises movably actuatable locking and wedge elements 5 as well as a central turnable frame part 3 and turnable sleeves 1 , 2 connecting the same, which frame part 3 and which turnable sleeves 1 , 2 are provided with threads 6-9. The tool 4 is actuated by a torsional force 10, whereby by means of the tool 4 a pressing force 1 1 is provided to the backing 35, as well as a clamping force 12 and a pulling force 13 to the bolt 31 or the nut 32, for providing unscrewing or tightening of the bolt joint 33. After the tool 4 has been placed against the backing 35 so that it surrounds the bolt head 34 or the nut 32, a locking sleeve 1 situated internally in the tool 4 is screwed in the clockwise direction to provide a clamping force to the bolt 31 or the nut 32. Next, a surrounding outside sleeve 2 is screwed also in the clockwise direction to provide lifting force of the bolt joint 33 by the outside sleeve 2 actuating the backing 35 by a pressing force, whereupon the frame part 3 being central internally in the tool 4 is actuated to be turned in the counter-clockwise direction, until the bolt joint 33 comes loose by a pulling force to the bolt 31 or the nut 32 being provided, or for the clamping of the same when the opposite end thereof is being attached.

As shown in the figures, the locking sleeve 1 is arranged surrounding around the frame part 3, so that the frame part 3 can run inside the locking sleeve 1 . The outside sleeve 2 is arranged surrounding around the locking sleeve 1 , so that the locking sleeve 1 and the frame part 3 can run inside the outside sleeve 2.

When the locking sleeve 1 is screwed clockwise, it moves in a downward direction in relation to the frame part 3. By the downward direction, the locking sleeve 1 actuates locking and wedge elements 5, which are at least partly arranged between the frame part 3 and the locking sleeve 1 , so that the locking and wedge elements 5 engage with the bolt 31 or nut 32 of the bolt joint 33, see Figures 9-12. The locking and wedge elements 5 are formed so that when they engage under the bolt head 34 or the nut 32 for providing a wedge action between the bolt head 34 or the nut 32 and the backing 35. The backing 35 may, as has been described above, consist of the proper object against which the bolt joint 33 abuts and is locked or of a washer 35A. The locking sleeve 1 is initially screwed in the clockwise direction by hand and is then tightened by tool until the nut 32 is rigidly attached with about half the recommended tightening torque of the bolt joint 33. The outside sleeve 2 is then screwed down in the clockwise direction against the backing 35 to provide lifting force, and suitable torque is also here about half the recommended tightening torque of the bolt joint 33. Finally, the central frame part 3 is turned in the counter-clockwise direction, until the nut 32 wishes to come loose. If necessary, it is possible to, by means of a screwdriver, not shown, which is lowered in a centrally situated through-channel 14 in the central frame part 3, actuate a sawn groove 39 in the head 34 of the bolt.

The tool 4, which is suitable for carrying out a method according to the present invention, comprises at least three parts 1-3 extending along a common central axial centre axis 22, the turnable sleeves 1-2 of which, which pair wise surround the central frame part 3, are surroundingly provided with co-operating threads 8-9, as well as that also the central frame part 3 has threads 6-7 cooperating with the surrounding adjacent locking sleeve 1 . A number of locking and wedge elements 5 are furthermore carried by the tool 4, whereby the threads 6-9 allow the parts 1-3 to be displaced in relation to each other so that torsional force 10 on the tool 4 provides pressing 1 1 , clamping 12, as well as pulling 13 forces. The internal central frame part 3 is formed of a bar or sleeve, and is provided with the central axial through-channel 14 and external threads 6 along a certain section A, see Figure 4. The frame part 3 is furthermore provided with external key grip 15 as well as internal key recess 16 situated at the upper end portion 3A of said frame part. The internal central frame part 3 supports, along the circumference of the same, the distributing locking and wedge elements 5, which are pivotably mounted at the lower end portion 3B of the frame part, and received in recesses 17 in the lower end portion 3B of the frame part. The locking and wedge elements 5 have an essentially flat under side 25 and a pointed edge portion 26 as well as an upper pivot mounting portion 27 and a lower clamping jaw portion 28. Furthermore, the locking and wedge elements 5 are actuated by spring force from spring means 18 so that they can be brought to an inactive turned-out position of rest I, see Figure 5. The spring means 18 are formed, for instance, of piano wire or leaf springs shaped to arches and the spring means 18 are received in recesses 19-20 situated in the locking and wedge elements 5 and/or in the frame part 3, see Figures 8-9. Alternatively, the spring means 18 may be formed of a resilient element such as, for instance, a piece of material manufactured from suitable elastic or resilient material. Suitable materials for the spring means 18 in this case may, for instance, be nitrile rubber, natural rubber, or other suitable elastomers as well as resilient plastic materials. Furthermore, the outside sleeve 2 of the tool 4 has internal threads 9 at the upper end portion 2A thereof while the central locking sleeve 1 has both internal threads 7 at the upper end portion 1A thereof as well as external threads 8 along the major part of the length extension L of the locking sleeve, see Figures 5-6. The central locking sleeve 1 has a lower press portion 21 . which is adapted and intended to pressingly actuate the locking and wedge elements 5 to move in a direction inward toward 24 the centre 22 of the tool 4 when the locking sleeve 1 is screwed downward on the frame part 3, the press portion 21 being formed at the lower end portion 1 B of the downwardly tapering jacket 23 of the locking sleeve 1 . A complete tool 4 according to the invention may suitably comprise a central frame part 3, two surrounding sleeves 1 , 2, three locking and wedge elements 5, as well as three spring means 18, which are assembled to a screwable unit by means of suitable mounting tools, and the parts preferably consist of metal, e.g. steel or another hard metal, which may be hardened and tempered with coating if desired or be hardened or treated in another desired manner. The spring means 18 may alternatively be formed of the material of the proper locking and wedge elements 5. Preferably then of rubber, plastic, or of other elastic and resilient material. In Figure 7, there is shown how the frame part 3 at the upper end portion 3A thereof has fitting recesses 36-37 to form different internal key recesses 16, fitting to turning tools, around the central channel 14. Possibly, a friction increasing rubber washer 38, see Figure 6, may be arranged as shim between the backing 35 and the lower end portion 2B of the outside sleeve 2 to increase the friction. If the friction increases, said outside sleeve 2 will climb safer upward along the threads 8 of the locking sleeve 1 upon loosening of the joint and the tool 4. By the letter C, the maximal lifting height of the tool is designated.

In the use of the tool 4, the nut 32 or the bolt head 34 is actuated by the clamping force 12 from the locking and wedge elements 5 in a first stage when the locking sleeve 1 is screwed clockwise down on the frame part 3, since the locking and wedge elements 5 are pressed inward toward the nut 32 or the bolt head 34 by the locking sleeve 1. Simultaneously, the pointed edge portion 26 of the locking and wedge elements is wedged in between the nut 32 or the bolt head 34 and the backing 35. In a second stage, the outside sleeve 2 is screwed clockwise down over the locking sleeve 1 so that the lower end portion 2B contacts the backing 35. When the lower end portion 2B contacts the backing 35, the backing 35 is actuated by the pressing force 1 1 from the outside sleeve 2 at the same time as the bolt joint 33 is actuated by the pulling force 13, by the fact that the pressing force 1 on the backing 35 is transferred to the bolt joint 33 via the tool 4. When the tool 4 in a third stage is actuated by a torsional force 10 counter-clockwise by means of the levered turning tool 30, which is coupled together with the frame part 3, the pressing force 1 1 on the backing 25 and the pulling force on the bolt 31 or the nut 32 increase until the torsional force 10 can be transferred by the tool 4 to the bolt 31 or the nut 32 and in such a way loosen the bolt joint 33.

The directions of rotation in the method described above apply to right- threaded bolt joints and for left-threaded bolt joints the opposite directions of rotation apply.

Nature and function of the invention should clearly have been appreciated from the above-mentioned and by what is shown in the drawings. The invention is however not limited to the embodiments described above and shown in the accompanying drawings. Modifications are feasible, particularly as for the nature of the different parts, or by using an equivalent technique, without departing from the protection area of the invention, such as it is defined in the claims.