Washer, fastener provided with a washer, method of and power tool for fastening objects

1. A washer, comprising a body having an axis, a radially outer part, a radially inner part and at least one resistive point, said radially outer part having a first bearing face surface located at one axial side and adapted to cooperate with a nut and a second bearing face surface located at an opposite axial side and adapted to cooperate with an object, said radially inner part having at least one third turning resistant surface adapted to cooperate with a thread of a bolt, so that when the nut is turned and turns the bolt said body of the washer stops the bolt from turning and thereby the nut creates a pull on the bolt which elongates the bolt in an axial direction and applies to said turning resistant surface an axial force which overcomes the at least one resistive point so that said radially outer part of said body does not move axially, while said radially inner part of said body of the washer with said turning resistant surface cooperating with the thread of the bolt is allowed to be pulled axially when the bolt elongates, wherein said radially outer part and said radially inner part are configured so that inside said radially outer part, an axial space remains, into which said radially inner part moves as it is pulled axially when the bolt elongates wherein said radially outer part and said radially inner part are configured so that inside said radially outer part, a free axial space remains, into which said radially inner part moves as it is pulled axially when the bolt elongates.

2. A washer as defined in claim 1 , wherein said radially outer part prevents initially an axial displacement of the radially inner part which is engaged with the bolt, and thereafter said radially outer part is broken at said at least one resistive point under the action of the axial force.

3. A washer as defined in claim 1 , wherein said body is formed as a one-piece integral element, which subsequently is broken at said at least one resistive point under the action of the axial force.

4. A washer as defined in claim 1 , wherein one of said parts has a deformable formation which forms said resistive point and is formed so as to prevent initially an axial displacement of said radially inner part which is engaged with the bolt, and thereafter said formation is deformed under the action of the axial force to allow an axial displacement of said radially inner part engaged with the bolt relative to said radially outer part of said body.

5. A washer as defined in claim 4 , wherein said formation is formed as a radially outwardly extending skirt-shaped portion.

6. A washer as defined in claim 4 , wherein said formation is formed as a radially outwardly extending knurl-shaped portion.

7. A washer, comprising a body having an axis and provided with a first bearing face surface located at one axial side and adapted to cooperate with a nut, a second bearing face surface located at an opposite axial side and adapted to cooperate with an object, at least one third turning resistant surface adapted to cooperate with a thread of the bolt, said body having at least one resistive point arranged so that when the nut is turned and turns the bolt said body of the washer stops the bolt from turning and thereby the nut creates a pull on the bolt which elongates the bolt in an axial direction and applies to said body of the washer an axial force which overcomes the at least one resistive point so that a portion of said body of the washer is allowed to be pulled axially when the bolt elongates, wherein said body has two parts which are press fit over one another so as to form said resistive point, so that an axial displacement of said parts relative to one another is initially prevented, and thereafter under the action of the axial force one of said parts is axially displaced relative to the other of said parts, wherein said two parts including a radially inner part and a radially outer part, wherein said radially outer part and said radially inner part are configured so that inside said radially outer part, an axial space remains, into which said radially inner part moves as it is pulled axially when the bolt elongates wherein said radially outer part and said radially inner part are configured so that inside said radially outer part, a free axial space remains, into which said radially inner part moves as it is pulled axially when the bolt elongates.

8. A fastener for connecting two parts which constitute an object, comprising a bolt having a thread; a nut screwable on said bolt; and a washer to be applied between the nut and the object and including a body having an axis, a radially outer part, a radially inner part and at least one resistive point, said radially outer part having a first bearing face surface located at one axial side and adapted to cooperate with the nut and a second bearing face surface located at an opposite axial side and adapted to cooperate with the object, said radially inner part having at least one third turning resistant surface adapted to cooperate with the thread of said bolt, so that when the nut is turned and turns the bolt said body of the washer stops the bolt from turning and thereby the nut creates a pull on the bolt which elongates the bolt in an axial direction and applies to said turning resistant surface an axial force which overcomes the at least one resistive point so that said radially outer part of said body does not move axially, while said radially inner part of said body of the washer with said turning resistant surface cooperating with the thread of the bolt is allowed to be pulled axially when the bolt elongates, wherein said radially outer part and said radially inner part are configured so that inside said radially outer part, an axial space remains, into which said radially inner part moves as it is pulled axially when the bolt elongates wherein said radially outer part and said radially inner part are configured so that inside said radially outer part, a free axial space remains, into which said radially inner part moves as it is pulled axially when the bolt elongates.

9. A fastener as defined in claim 8 , wherein said radially outer part prevents initially an axial displacement of said radially inner part which is engaged with the bolt, and thereafter said radially inner part is broken at said at least one resistive point under the action of the axial force.

10. A fastener as defined in claim 8 , wherein said body is formed as a one-piece integral element which includes said parts, which subsequently is broken at said breaking point under the action of the axial force.

11. A fastener as defined in claim 8 , wherein one of said parts has a deformable formation which forms said resistive point and is formed so as to prevent initially an axial displacement of said radially inner part which is engaged with the bolt, and thereafter said formation is deformed under the action of the axial force to allow an axial displacement of said radially inner part engaged with the bolt relative to said radially outer part of said body.

12. A fastener as defined in claim 11 , wherein said formation is formed as a radially outwardly extending skirt-shaped portion.

13. A fastener as defined in claim 11 , wherein said formation is formed as a radially outwardly extending knurl-shaped portion.

14. A fastener for connecting two parts which constitute an object, comprising a bolt having a thread; a nut screwable on said bolt; and a washer to be applied between the nut and the object and including a body having an axis and provided with a first bearing face surface located at one axial side and adapted to cooperate with the nut, a second bearing face surface located at an opposite axial side and adapted to cooperate with the object, and at least one third turning resistant surface adapted to cooperate with the thread of said bolt, said body of said washer having at least one resistive point arranged so that when the nut is turned and turns the bolt said body of the washer stops the bolt from turning and thereby the nut creates a pull on the bolt which elongates the bolt in an axial direction and applies to said body of the washer an axial force which overcomes the at least one resistive point so that a portion of said body of the washer is allowed to be pulled axially when the bolt elongates, wherein said body has two parts which are press fit over one another so as to form said resistive point so that an axial displacement of said parts relative to one another is initially prevented, and thereafter under the action of the axial force one of said parts is axially displaced relative to the other of said parts, wherein said two parts including a radially inner part and a radially outer part, wherein said radially outer part and said radially inner part are configured so that inside said radially outer part, an axial space remains, into which said radially inner part moves as it is pulled axially when the bolt elongates said two parts including a radially inner part and a radially outer part wherein said radially outer part and said radially inner part are configured so that inside said radially outer part, a free axial space remains, into which said radially inner part moves as it is pulled axially when the bolt elongates.