GB2540339A

GB2540339A - Nuts and bolts

Info

Publication number: GB2540339A
Application number: GB1510135.5A
Authority: GB
Inventors: Parker Simon
Original assignee: Punk Couplings Ltd
Current assignee: Punk Couplings Ltd
Priority date: 2015-06-11
Filing date: 2015-06-11
Publication date: 2017-01-18
Anticipated expiration: 2035-06-11
Also published as: GB201510135D0; GB2540339B

Abstract

A nut 10 or bolt 20 comprising an inner member 22, an intermediate annular member 14 , 24 and an outer annular member 26. The outer surface of the inner member is spherical and the inner surface of the intermediate member is spherical and the outer surface is convex. The members share a common axis when aligned. The intermediate member is constrained to rotate (pivot, swivel, revolve, turn) with respect to the inner member about a first axis and the outer member is constrained to rotate with respect to the intermediate member about a second axis. Optional features include a flange, an elongate projection, loading slots, a threaded aperture and a splined shank.

Description

NUTS AND BOLTS

[0001] This invention relates to nuts and bolts.

[0002] Mechanical couplings are well known. Examples include couplings for coupling angularly misaligned shafts, universal joints, constant velocity joints, couplings for coupling a drive shaft to a driven shaft, couplings for connecting a torque shaft to a structural element of, for example, a suspension system.

[0003] In some engineering applications two structural members with non-parallel faces are required to be fixed together with one or more nuts and bolts. By a bolt engaging with a tapped or threaded hole in a structural element. To avoid bending forces being generated within the fixing misalignment devices such as special spherical washer assemblies are used to compensate for the non-parallel faces. However these tend to be limited in their angular misalignment range to a few degrees.

[0004] According to the present invention a component being a nut or a bolt comprises: • an inner member, and an outer annular member and an annular intermediate member, each member, when aligned having a common axis and a common centre on the axis; • the inner member having an outer convex spherical periphery; • the intermediate annular member having an inner spherical concave periphery into which the outer convex periphery of the first annular member is received; • the intermediate member having an outer convex periphery and the outer member having an inner spherical concave periphery into which the outer convex periphery of the intermediate member is received; • the intermediate member being constrained to rotate with respect to the inner member about a first axis; and • the outer member being constrained to rotate with respect to the intermediate member [0005] Preferably the first axis is perpendicular to the common axis.

[0006] Preferably the second axis is perpendicular to both the first axis and the common axis.

[0007] The side surface of the outer member which will engage against an item to which the component is to be fixed is normally planar.

[0008] For most practical purposes the outer surface of the outer member is hexagonal to receive a spanner, but may be other shapes where special keys are used to bolting or unbolting.

[0009] Ideally, but not essentially, the outer periphery of the outer member has a flange extending outwards perpendicularly to the common axis and one side of the flange to engage with item to which the nut or bolt is to be fixed.

[0010] In one arrangement the outer convex periphery of the inner member has at least one elongate projection projecting into an elongate slot in the concave inner periphery of the intermediate member, each projection and elongate slot being elongate in a plane containing or parallel to the common axis, the slot and projection projecting in the direction of the said plane, and arranged to co-act with the pair of members to transmit torque between the members.

[0011] In such an arrangement the outer convex periphery of the intermediate member has at least one elongate projection projecting into an elongate slot in the concave inner surface of the outer member, each projection and elongate slot being elongate in a plane containing or parallel to the common axis, the slot and projection projecting in the direction of the said plane, and arranged to co-act with the pair of members to transmit torque between the members.

[0012] Preferably the intermediate member and the outer member have a pair of diametrically opposed loading slots extending halfway across their width to enable the introduction of the inner member into the concave inner periphery of the intermediate member, and to be retained axially by the intermediate member and the introduction of the intermediate member into the concave inner periphery of the outer member and to be retained axially by the outer member.

[0013] The loading slots of the nut or bolt should be outward facing away from the planer side surface of the outer members to maximise the axial loading capability.

[0014] For most practical applications the said members, other than the outer member, comprise spherical segments including a common centre.

[0015] A spherical segment is a portion of a sphere between with a pair of parallel planes.

[0016] In an alternative arrangement, one or more of the pairs of elongate projections and elongate slots is replaced by an axle mounted in one member extending into a borehole in the other, the axle being aligned with the first axis or second axis as appropriate.

[0017] As a nut, the inner member has a central threaded aperture to receive the thread shank of such as a bolt.

[0018] As a bolt, the inner member has a threaded shank extending axially, to pass through, say, items to be joined together, with by engaging in a threaded aperture on an item or the threaded aperture of a nut.

[0019] As a bolt the inner member may have internal splines to receive external splines towards one end of what otherwise is a threaded shaft. The end has a cap to engage the side of the inner member opposite the side comprising the plane, [0020] Other features of the invention are found in the claims and/or the accompanying description.

[0021] This invention would be of particular use in civil engineering, ship building, heavy industrial and aerospace. It may offer advantages in earthquake ‘proofing’ steel frame structures by allowing some minor movement during the flexing of the structure.

[0022] This invention allows for up to 15 degrees misalignment per component, (up to 30 degrees total of a nut and bolt together according to the invention) and offers geometrically perfect loading on the thread bolt section i.e. it is entirely axially tensile loaded, with no bending or radial loading.

[0023] Examples of the invention are illustrated in the accompanying figures, in which [0024] Figure 1 shows a nut in accordance with the invention: [0025] Figure 2 shows the nut of figure 1 exploded to illustrate the individual components; [0026] Figure 3 shows a bolt according to the invention; [0027] Figure 4 shows the bolt of figure 3 exploded to illustrate the individual components; and [0028] Figure 5 shows an assembly comprising the nut and bolt of figures 1 to 4.

[0029] In Figures 1 and 2 a nut 10 comprises an inner annular member 12, and an outer annular member 16 and an annular intermediate member 14. Each member 12, 14 and 16, when aligned, has a common axis X and a common centre C on the axis X.

[0030] The inner member 12 has an outer convex spherical periphery 120 and a central bore122 whose axis is common with the axis X. The inner periphery 124 of the inner member 12 has a thread 126 which will engage with an external thread on a shank screwed into the bore 122.

[0031 ] The outer convex spherical periphery 120 of the inner member 12 has diametrically opposite elongate first projections 128 extending radially of and parallel to the common axis X. The outer surface of each of the projections 128 is a partial sphere concentric with the spherical convex surface 120 or a partial cylinder whose axis is common with the central axis X of the inner member 12.

[0032] The projections extend into first complementary slots 146 in the inner concave inner periphery 140 of the intermediate member 14. The projections 128 and slots 146 constrain the inner member 12 and intermediate member 14 to be rotatable one relative to the other about a second axis Y of rotation through and perpendicular to the axis X.

[0033] The intermediate annular member 14 has an inner spherical concave periphery 140 into which the outer convex periphery 120 of the inner member 12 is received.

[0034] The intermediate member 14 has an outer convex periphery 144 and the outer member 16 has an inner spherical concave periphery 160 into which the outer convex periphery 144 of the intermediate member 14 is received.

[0035] Second elongate projections 148 extend radially of, and parallel to, the axis X from the convex spherical surface 144 of the intermediate member 14. The outer surface of each of the projections 148 is a partial sphere concentric with the spherical convex surface 140 or a partial cylinder whose axis is common with the central axis of the intermediate member 14.

[0036] The projections 148 extend into complementary, second, slots 166 in the inner concave surface 160 of the outer member 16. The second projections 148 and second slots 166 are perpendicular to the first projections 128 and first slots 146. They constrain the intermediate member 14 and outer member 16 to be rotatable one relative to the other about a third axis Z of rotation through the centre point C, and perpendicular to both the common axis X and second axis Y.

[0037] The outer surface of the 164 of the outer member is normally formed as a hexagon (as in the surfaces of conventional bolts to receive a spanner). However, for special applications the outer member may be formed as another polygon or otherwise be adapted to receive a particular key.

[0038] The side surface 162 of the outer member 16 which will engage against an item to which the nut is to be fixed is planar.

[0039] A flange 168 extending outwards from the outer member 16 perpendicularly to the common axis X with one side 169 of the flange 168 to engage with item to which the nut is to be fixed, the side 169 having a common planer surface with the side 162 of the outer member 16.

[0040] The intermediate member 14 and the outer member 16 each have a pair of diametrically opposed loading slots 141 (intermediate member) and 161 (outer member) extending halfway across their width to enable the introduction of the inner member 12 into the concave inner periphery 120 of the intermediate member 14, and to be retained axially by the intermediate member 14 and the introduction of the intermediate member 14 into the concave inner periphery 160 of the outer member 16 and to be retained axially by the outer member.

[0041] The loading slots 161 of the outer member 16 are in the opposite side of the member 16 to the side surface 162.

[0042] In Figures 3 and 4 a bolt 20 comprises an inner annular member 22, and an outer annular member 26 and an annular intermediate member 24. Each member 22, 24 and 26, when aligned, has a common axis X and a common centre C on the axis X.

[0043] The inner member 22 has an outer convex spherical periphery 220 and a central bore 222 whose axis is common with the axis X. The inner periphery 224 of the inner member 22 has splines 226 which engage with external splines 232 at one end of a threaded shank 23 extending from the bolt 20, the end of the shank 23 has a cap 234 which engages the side 227 of the inner member 22. The shank 23 extends from the bolt co-axially with common axis X on the side of the bolt to engage with an item to be bolted. It can be seen that when the bolt is deployed, the cap 234 bears against side 227 holding the shank 23 in place longitudinally, the engaging splines 226 and 232 hold the shank in place against rotation.

[0044] The outer convex spherical periphery 220of the inner member 22 has diametrically opposite elongate first projections 228 extending radially of and parallel to the common axis X from the convex spherical surface 228 of the inner member 22. The outer surface of each of the projections 228 is a partial sphere concentric with the spherical convex surface 220 or a partial cylinder whose axis is common with the central axis X of the inner member 22.

[0045] The projections extend into first complementary slots 246 in the inner concave surface 240 of the intermediate member 24. The projections 228 and slots 246 constrain the inner member 22 and intermediate member 24 to be rotatable one relative to the other about a second axis Y of rotation through and perpendicular to the common axis X.

[0046] The intermediate annular member 24 has an inner spherical concave periphery 240 into which the outer convex periphery 220 of the inner member 22 is received.

[0047] The intermediate member 24 has an outer convex periphery 244 and the outer member 26 has an inner spherical concave periphery 260 into which the outer convex periphery 244 of the intermediate member 24 is received.

[0048] Projections 248 extend radially of, and parallel to, the common axis X from the convex spherical surface 244 of the intermediate member 24. The outer surface of each of the projections 248 is a partial sphere concentric with the spherical convex surface 244 or a partial cylinder whose axis is common with the central axis of the intermediate member 24.

[0049] The projections 248 extend into complementary, second, slots 266 in the inner concave periphery 260 of the outer member 26. A plane containing projections 248 and slots 266 is orthogonal to a plane containing the first projections 228 and first slots 246. The combination of projections 248 and slots 266 constrain the intermediate member 24 and outer member 26 to be rotatable one relative to the other about a third axis Z of rotation through the centre point C, and perpendicular to both axis X and second axis Y.

[0050] The outer surface 264 of the outer member 26 is normally formed as a hexagon (as in the surfaces of conventional bolts to receive a spanner). However, for special applications outer member may be formed as another polygon or otherwise be adapted to receive a particular key.

[0051] The side surface 262 of the outer member 26 which will engage against an item to which the bolt 20 is to be fixed is planar.

[0052] A flange 268 extending outwards from the outer member 26 perpendicularly to the common axis X with one side 269 of the flange 268 to engage with item to which the nut is to be fixed, the side 269 having a common planer surface with the side 262 of the outer member 26.

[0053] The intermediate member 24 and the outer member 26 each have a pair of diametrically opposed loading slots 241 (intermediate member) and 261 (outer member) extending halfway across their width to enable the introduction of the inner member 22 into the concave inner periphery240 of the intermediate member 24, and to be retained axially by the intermediate member 24 and the introduction of the intermediate member 24 into the concave inner periphery 260 of the outer member 26 and to be retained axially by the outer member 26.

[0054] The loading slots of the nut or bolt should be outward facing away from the surface 262 to engage an item to with the nut is to be fixed to give maximum axial load capability.

[0055] Turning to figure 5 a nut 10 and bolt 20, each according to the invention, are used to assemble a first wedge shaped element 50 below to a second wedge shaped element 52 which is 90° to the first giving a compound angle of 15/15 degrees. The flange 268 and side surface 262 of bolt 20 are engaged against the first wedge 50 and the shank 23 of the bolt 20 is inserted through holes 51 and 53 respectively in the first wedge element 50 and second wedge element 52 extending below. The nut 10 is screwed onto shank 23 by the internal threads 126 of inner member 12 engaging the external threads 230 of shank 23. As the surface 162 of outer member 16 of nut 10 engages the wedge element intermediate of nut 10 member 14 rotates about axis Y with respect to inner member 12 of nut 10 and the outer member 16 of nut 10 rotates about axis Z with respect to the intermediate member 14, allowing the surface 162 and flange 168 engage flush against the sloping side of wedge element 52. The elements of the bolt 20 remain aligned with the outer member 26 not rotating with respect to intermediate member 24 and intermediate member 24 not rotating with respect to inner member 22. As the nut 10 is tightened the splines 226 and 232 prevent rotation of the shank 23, and the cap 234 bears against surface 227 of bolt 20. (The bolt head is misaligned due to the 15o/15o degrees compound angle).

[0056] It will be clear that in figure 5, the bolt 20 could be replaced by a conventional bolt if the first wedge element 50 was replaced by a plain board. Likewise if the second wedge element 52 was replaced by a plain board, nut 10 could be replaced by a conventional nut. However, in situations where the both outer faces present themselves at angles to the hole through which a bolt is to pass rather than being substantially orthogonal, then both the nut 10 and bolt 20 would be used. As described earlier the use of a nut and bolt according to the invention will allow for up to 15/15 degree compound angle.

[0057] Although the examples show the first and second axes perpendicular to one another and the first axis perpendicular to the common axis, the component will work, albeit less well if this is not the case provided that the axes are not parallel, [0058] The operation of the invention is analogous to the coupling described in pending international patent application PCT/GB2014/053679, the content of which is incorporated by reference.

[0059] The pairs of projections and slots 128 and 146, 148 and 166, 228 and 246, 248 and 266, can be replaced by individually of completely by a combination of axles mounted in bores aligned on the desired axis of rotation of one element about the other. The axle and bores are aligned about the axis of which it is desired that the member into which the axle fixed should rotate with respect to the element in which the bore formed. This arrangement is analogous to the arrangements described in pending PCT Patent Application PCT/GB2014/053680, the content of which is incorporated by reference.

[0060] The invention provides is a geometrically perfect fixing system that is purely in tension between the bolt head and the nut, irrespective of the accuracy of the structures sandwiched between the nut and bolt head. The invention is particularly useful in aligning or pulling together sprung flexible plates, adjusting themselves continuously during the clamping process i.e. not digging as would conventional fixings.

[0061] In figure 5, if the aperture 53 in the second wedge was threaded and the diameter and pitch of the threaded shank 23 matched, the bolt 20 could be screwed into the second wedge 52, without the need of a nut. As a further alternative the shank 23 could be self-tapping and be screwed directly through wedge 50 into wedge 52.

[0062] In description the axes of rotation of the outer member about the intermediate member and of the intermediate member about the inner member are perpendicular to one another and to the central axis X. Although this is the preferred arrangement, the axes need only be at angles to one another, although the operation of the device is less effective.

Claims

1. A component being a nut or a bolt comprising: • an inner member, and an outer annular member and an annular intermediate member, each member, when aligned having a common axis and a common centre on the axis; • the inner member having an outer convex spherical periphery; • the intermediate annular member having an inner spherical concave periphery into which the outer convex periphery of the first annular member is received; • the intermediate member having an outer convex periphery and the outer member having an inner spherical concave periphery into which the outer convex periphery of the intermediate member is received; • the intermediate member being constrained to rotate with respect to the inner member about an first axis; and • the outer member being constrained to rotate with respect to the intermediate member about a second axis.

2. A component being a nut or a bolt according to claim 1 characterised in that the outer periphery of the outer member has a flange extending outwards perpendicularly to the common axis and one side of the flange to engage with item to which the component nut is to be fixed.

3. A component being a nut or a bolt according to claim 1 or 2 characterised in that the outer convex periphery of the inner member has at least one elongate projection projecting into an elongate slot in the concave inner surface of the intermediate member, each projection and elongate slot being elongate in a plane containing or parallel to the common axis, the slot and projection projecting in the direction of the said plane, and arranged to co-act with the pair of members to transmit torque between the members.

4. A component being a nut or a bolt according to claim 3 characterised in that the outer convex periphery of the intermediate member has at least one elongate projection projecting into an elongate slot in the convex inner periphery of the outer member, each projection and elongate slot being elongate in a plane containing or parallel to the common axis, the slot and projection projecting in the direction of the said plane, and arranged to co-act with the pair of members to transmit torque between the members.

5. A component according to any one of claims 1 or 2 characterised in comprising one or a diametrically opposed pair of axles disposed radially of the common centre of intermediate and outer members and coupling the said members to constrain the said members to be rotatable one relative to the other about the axle(s), the axis of the axles being perpendicular to the common axis and to the axis about which the intermediate member rotates about the inner member.

6. A component according to any one of claims 1,2 or 5 characterised in comprising one or a diametrically opposed pair of axles disposed radially of the common centre of inner and intermediate members and coupling the said members to constrain the said members to be rotatable one relative to the other about the axle(s), the axis of the axles being perpendicular to the common axis and to the axis about which the outer member rotates about the intermediate member.

7. A component according to any preceding claim in which the first axis is perpendicular to the common axis.

8. A component according to claim 7 in which the second axis is perpendicular to both the first axis and the common axis.

9. A component according to any preceding claim characterised in that the intermediate member and the outer member have a pair of diametrically opposed loading slots extending halfway across their width to enable the introduction of the inner member into the concave inner periphery of the intermediate member, and to be retained axially by the intermediate member and the introduction of the intermediate member into the concave inner periphery of the outer member and to be retained axially by the outer member.

10. A component according to claim 9 characterised in that the loading slots of the nut or bolt should be outward facing away from the planar side surface of the outer member.

11. A component according to any preceding claim characterised in that inner member and intermediate comprise spherical segments including a common centre.

12. A component according to any preceding claim characterised in that the inner member has a central threaded aperture to receive a thread shaft.

13. A component according to any preceding claim characterised in that the inner member has a threaded shaft extending axially therefrom.

14. A component according to claim 13 characterised in that the inner member has a central aperture the periphery of the aperture having splines engaging which corresponding splines on the shank, to retain the shank form rotating with respect to the inner member.

15. A component according to claim 13 or 14 characterised in that the shank has an end cap engaging the side of the inner member.

16. A component comprising a nut and bolt, the nut being as claimed in claim 12 and the bolt as claimed in any one of claims 13 to 15.

17. A component comprising a nut or a bolt substantially as hereinbefore described with reference to the accompanying drawings.