Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B31/00—Screwed connections specially modified in view of tensile load; Break-bolts
  • F16B31/02—Screwed connections specially modified in view of tensile load; Break-bolts for indicating the attainment of a particular tensile load or limiting tensile load
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S411/00—Expanded, threaded, driven, headed, tool-deformed, or locked-threaded fastener
  • Y10S411/924—Coupled nut and bolt
  • Y10S411/929—Thread lock
  • Y10S411/931—Superposed nuts

Definitions

• the invention relates to a torque nut or torque screw, i.e. a fastening device with fastening threads, i.e. threads which are operative for the fastening function of the device and with an indication means which is integrated in the device to be released at a predetermined tightening torque, comprising an inner fastening member having said fastening threads and outside of the inner fastening member an outer female member rotatable by means of a spanner, a pair of pliers, a screw driver, or other tool, said female member being connected to the inner fastening member by means of a coupling having a sufficient strength to transfer to the inner fastening member a torque of the magnitude for which the fastening device is designed, and wherein the outer female member is provided, at the tightening of the coupling, to be released and rotated relative to the inner fastening member but not until the predetermined torque is exceeded.
• the purpose of the invention is to provide torque nuts and torque screws which can take over the "indication function" of the dynamometric tool, i.e. which can be tightened with a predetermined torque by means of a conventional tool.
• This can be achieved therein that the coupling between the outer female member and the inner fastening member consists of a conical screw coupling.
• the predetermined torque can be set by a certain tightening of the screw coupling.
• the outer female member consists of a nut according to a first preferred embodiment of the invention, wherein the predetermined torque is set by a certain tightening of the screw coupling between the outer nut and the inner fastening member.
• the inner fastening member also may consist of an inner nut, wherein the inner nut, according to an embodiment , may be longer than the outer nut and extend between the outer nut in its two ends.
• the inner fastening member may have an outwardly directed flange or other abutment means in its outer end, against which abutment means the outer nut is tightly screwed with such a force that the joint between the outer nut and the inner fastening member can be released only by the application of said predetermined torque.
• the outer end of the inner fastening member which o preferably is designed as a flange, further may have a hexagonal outer cross-section in order to provide lands for a wrench for easing off the inner fastening member when the joint shall be undone.
• the inner fastening member may also be provided with a hex socket for an Allen key or with grooves for a screw driver in its outer end.
• the fastening member comprises a head designed as a nut with conical threads, the imaginary point of the cone being directed away from the fastening threads of the fastening member.
• a screw having conical threads cooperative with the conical threads in said head, wherein said screw having conical threads is rotatable by means of a spanner, a pair of pliers, a screw driver
• said screw having conical threads is joined to the fastening member by a certain tightening of the conical screw joint in order to transfer, to the fastening member, torques of a magnitude for which the fastening member is designed, while said screw having conical threads in said head is provided, when tightening the fastening member, to
• Fig. 1 illustrates, partly in section, a first preferred embodiment in which the inner fastening member consists of a nut;
• Fig. 2 illustrates a second embodiment, in which the inner fastening member consists of a screw;
• Fig. 3 shows a modification of the embodiment, where the inner fastening member consists of a screw
• Fig. 4 illustrates still another embodiment of the invention.
• Fig. 1 there is shown a screw-nut joint consisting of a torque nut, generally designated 1, and a conventional screw 2.
• a pair of plates 3, 4 or the like have a through-hole for the screw 2 and are clamped together between the screw head 6 and the torque nut 1.
• the plates 3, 4 are clamped between the screw head 6 and an inner nut 7, which is included as an inner fastening means in the torque nut 1.
• the inner nut 7 has normal, straight fastening threads 8, cooperative with the threads 9 of screw 2.
• the inner nut 7 has a longer axial extension than the outer nut 10 and the inner end portion 11 of it abuts the object - the plates 3, 4 - which are clamped in the joint.
• a radially - outwardly - directed flange 12 which preferably has a hexagonal section to provide wrench lands for a conventional spanner for the undoing of the joint.
• the thread 13 between the inner 7 and the outer nut 10 is conical, sloping towards the screw head 6.
• the threads in the thread coupling 13 are cut in the same direction as the screw threads 9, i.e. are normally right-threaded.
• the outer nut 10 is screwed tightly on the inner nut 7, such that it has been brought to close engagement with flange 12, which is possible by a proper dimensioning of the diameters of the two nuts 7, 10 in sections of the thread coupling 13. Thereafter, the nut 10 has been tightened somewhat more against the flange 12.
• a very favourable development of forces is achieved in the joint between the two nuts 7 and 10 in the torque nut 1.
• the torque nut 1 When operated, the torque nut 1 is screwed on the screw 2 in the normal way, e.g. by means of an adjustable spanner, a monkey wrench, a ring spanner, or other type of open- ended spanner, slip joint pliers or similar tools.
• an adjustable spanner e.g. a monkey wrench, a ring spanner, or other type of open- ended spanner, slip joint pliers or similar tools.
• the inner nut 7 with its inner portion 11 is well in engagement with the plate 3
• the joint is tightened still more.
• the outer nut 10 is eased, wherein the joint is prevented from being tightened too much. Due to the fact that the thread coupling 13 is conical there is a correspondence between the easing torque and the torque with which the inner nut 7 and the outer nut 10 initially has been united to each other.
• the joint can be prestressed or locked by increasing the tightening of the outer nut 10.
• the cortical thread coupling 13 under the condition that the axial displacement and the sloping angle of the cone are comparatively small.
• the sloping angle should be 1-5°, preferably 1-3°. It should also be noted that the pitch of thread coupling 13 is substantially smaller than that of the fastening threads 8.
• the inner fastening member i.e. the inner nut 7
• the inner fastening member i.e. the inner nut 7
• a conventional tool If the flange 12 is hexagonal, a conventional spanner can be used. If it is round, various types of pliers can be used.
• the inner fastening member consists of a screw T cooperating with a nut 6*.
• the screw T is provided with fastening threads 8' cooperative with threads 9' in the nut 6'.
• the outer nut 10 is identical with a corresponding outer nut in the torque nut in the foregoing embodiment. Details having identical correspondences in the above embodiment therefore have been given the same reference numerals.
• the screw T is provided with a hex socket 15 for an Allen key.
• the function is analogous with what has been explained with reference to the foregoing embodiment.
• FIG. 3 there is an inner fastening member in the form of a screw 17 cooperating with an outer nut 20. Between a screw head 21 and the nut 20 there is provided a conical thread joint 23. The fastening threads of screw 17 are designated 18. On screw 17 there is also a flange 22 intended to function as an abutment against the object which shall be clamped by means of a screw/nut joint in which the screw 17 forms a part.
• the flange 22 can be said to correspond to portion 11 at the embodiment according to Fig. 2.
• nut 20, in that end which is opposite of screw 17, has an hex socket 25 for an Allen key. This is used for tightening the joint in the same manner as. according to the embodiment of Fig. 2.
• the embodiment according to Fig. 4 comprises a screw 27 with fastening threads 28 and a screw head 31 designed as a nut.
• a screw 30 having the same function as the nuts 10 and 20, respectively, according to the foregoing embodiments.
• a conical thread coupling 33 Between screw 30 and nut 31 there is a conical thread coupling 33.
• the conicity is such that the imaginary point of the cone is turned away from the fastening threads 28.
• a hex socket 35 for an Allen key in the screw 30 In order to rotate the screw 30 there is a hex socket 35 for an Allen key in the screw 30.
• the surface 34 of the screw head 31 serves as an abutment against a working piece.
• the internally conical shape of the screw head 31 can be achieved by pressing against the previously arranged screw 30.
• the screw 27 When operated, the screw 27 is screwed tight by means of an Allen key in the hex socket 35.
• the surface 34 of screw 31 has been brought into contact with the work piece (not shown), the joint is further tightened. Finally, when the torque exceeds a predetermined torque, the inner screw 30 is eased.
• the gap 30 is provided.
• the screw head 31 can be used, which for this purpose is gripped by a suitable tool.
• the exterior of the screw head 31 for this purpose can be hexagonal or be provided with splines or the like to provide improved wrench lands for a spanner.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
• Rotary Pumps (AREA)
• Iron Core Of Rotating Electric Machines (AREA)
• Hand Tools For Fitting Together And Separating, Or Other Hand Tools (AREA)

Priority Applications (14)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26660967

Family Applications (1)

Country Status (14)

Cited By (4)

Families Citing this family (5)

Citations (5)

Family Cites Families (4)

• 1991
  • 1991-01-16 SE SE9100131A patent/SE467797B/sv unknown
• 1992
  • 1992-07-15 AU AU24919/92A patent/AU672757B2/en not_active Ceased
  • 1992-07-15 JP JP50396994A patent/JP3237847B2/ja not_active Expired - Fee Related
  • 1992-07-15 ES ES92918232T patent/ES2102515T3/es not_active Expired - Lifetime
  • 1992-07-15 DK DK92918232.7T patent/DK0650560T3/da active
  • 1992-07-15 KR KR1019940704843A patent/KR100224511B1/ko not_active IP Right Cessation
  • 1992-07-15 WO PCT/SE1992/000519 patent/WO1994002749A1/en active IP Right Grant
  • 1992-07-15 AT AT92918232T patent/ATE151506T1/de not_active IP Right Cessation
  • 1992-07-15 DE DE69218972T patent/DE69218972T2/de not_active Expired - Fee Related
  • 1992-07-15 CA CA002138269A patent/CA2138269C/en not_active Expired - Fee Related
  • 1992-07-15 US US08/362,569 patent/US5688088A/en not_active Expired - Fee Related
  • 1992-07-15 EP EP92918232A patent/EP0650560B1/en not_active Expired - Lifetime
• 1994
  • 1994-12-23 NO NO945010A patent/NO945010D0/no unknown
• 1995
  • 1995-01-11 FI FI950134A patent/FI105288B/sv not_active IP Right Cessation

Patent Citations (5)

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