CA2794673C - Load-relief washer for threaded fasteners therefor - Google Patents
Load-relief washer for threaded fasteners therefor Download PDFInfo
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- CA2794673C CA2794673C CA2794673A CA2794673A CA2794673C CA 2794673 C CA2794673 C CA 2794673C CA 2794673 A CA2794673 A CA 2794673A CA 2794673 A CA2794673 A CA 2794673A CA 2794673 C CA2794673 C CA 2794673C
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- 230000013011 mating Effects 0.000 claims abstract description 28
- 230000000295 complement effect Effects 0.000 claims abstract description 3
- 238000000034 method Methods 0.000 claims description 15
- 230000000712 assembly Effects 0.000 description 7
- 238000000429 assembly Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 230000004913 activation Effects 0.000 description 5
- 230000033001 locomotion Effects 0.000 description 5
- 230000009467 reduction Effects 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 230000002265 prevention Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000005381 potential energy Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 239000013590 bulk material Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
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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
- F16B43/00—Washers or equivalent devices; Other devices for supporting bolt-heads or nuts
- F16B43/009—Washers or equivalent devices; Other devices for supporting bolt-heads or nuts with a wedging effect in order to adjust the height of the washer
Abstract
A load relief washer assembly for threaded fasteners comprises a lower washer piece, an upper washer piece, a plurality of complimentary stepped features which further comprise the mating surfaces of said lower washer and said upper washer, such that sufficient rotation of said upper body relative to said lower body aligns said complementary stepped features allowing said upper body and said lower body to move toward each other, thereby reducing the overall height of the load relief washer assembly.
Description
Load-Relief Washer for Threaded Fasteners Therefor The present invention relates to a load-relief washer for threaded fasteners.
More specifically, the present invention relates to the use of a multiple part washer with complimentary stepped or castellated features to selectively eliminate the tensile load in a bolt or stud.
BACKGROUND OF THE INVENTION
Galling is a common complication that arises when fastening or disassembling threaded components. Galling can result in damage to the threaded features or seizing of said components.
Such damage or seizing can often be costly to repair or remedy. Galling is a form of adhesive wear and material transfer between metallic surfaces during operations in which relative motion of said surfaces is involved. The fastening of threaded components, in which interlocking threaded features are slid past each other under high loads, is an industrial operation which is notably prone or vulnerable to galling. Galling is a major concern in said application because the same features which promote galling, such as material ductility, metal on metal contact, friction, and high compressive loads, are not only present, but are indeed necessary features for operation.
However, galling can also occur at relatively low loads since localized pressure and energy density are greater than their respective macroscopic values. It is these local values which can result in elevated friction, promote material transfer, and induce phase transition. When two metallic surfaces, such as complimentary screw threads, are forced together, the high points or asperities found on each surface are the initial mating points. It is possible for said asperities to penetrate the opposing surface upon application of relative movement, thereby initiating plastic deformation and frictional forces between said surfaces. The induced pressure is highly localized, and the small region upon which the pressure is applied is termed the contact zone.
Said pressure elevation yields increased friction heating and adhesive forces, thereby resulting in initiation of material transfer, creation of additional protrusions, and growth of said protrusions.
Furthermore, galling is especially likely when disassembling threaded fasteners which have been in service for several years due to additional debris from local oxidation, foreign contaminants, and the breakdown, seepage, and removal of assembly lubricants.
The high ductility of commonly used machine screws can be considered a requisite characteristic for substantial material transfer and galling. Frictional heating is greatly related to the size, shape, and material properties of the plastic zones that surround the penetrating objects.
Correspondingly, brittle fractures rarely generate copious amounts of heat due to the small, transitory plastic zones. If the height of the protrusion grows larger than a critical threshold value, it may penetrate the brittle oxide layer of the complimentary mating surface. As a result, said protrusion could cause damage to the ductile bulk material on which the oxide layer originally formed, thus creating a region of plastic flow around said protrusion. Thus, the geometry, loading conditions, and relative motion of the protrusion govern the material flow, contact pressure, and thermal profile during sliding.
In the dynamic sliding contact of nut torqueing, increasing axial compressive force is proportionally equal to a rise in potential energy and thermal energy in the aforementioned localized system. Thus, the high loads and relative rotation associated with the torqueing of threaded nuts onto and off of threaded counterparts are particularly susceptible to galling.
Additionally, as the nut is turned further and sliding progresses, additional energy is supplied to
More specifically, the present invention relates to the use of a multiple part washer with complimentary stepped or castellated features to selectively eliminate the tensile load in a bolt or stud.
BACKGROUND OF THE INVENTION
Galling is a common complication that arises when fastening or disassembling threaded components. Galling can result in damage to the threaded features or seizing of said components.
Such damage or seizing can often be costly to repair or remedy. Galling is a form of adhesive wear and material transfer between metallic surfaces during operations in which relative motion of said surfaces is involved. The fastening of threaded components, in which interlocking threaded features are slid past each other under high loads, is an industrial operation which is notably prone or vulnerable to galling. Galling is a major concern in said application because the same features which promote galling, such as material ductility, metal on metal contact, friction, and high compressive loads, are not only present, but are indeed necessary features for operation.
However, galling can also occur at relatively low loads since localized pressure and energy density are greater than their respective macroscopic values. It is these local values which can result in elevated friction, promote material transfer, and induce phase transition. When two metallic surfaces, such as complimentary screw threads, are forced together, the high points or asperities found on each surface are the initial mating points. It is possible for said asperities to penetrate the opposing surface upon application of relative movement, thereby initiating plastic deformation and frictional forces between said surfaces. The induced pressure is highly localized, and the small region upon which the pressure is applied is termed the contact zone.
Said pressure elevation yields increased friction heating and adhesive forces, thereby resulting in initiation of material transfer, creation of additional protrusions, and growth of said protrusions.
Furthermore, galling is especially likely when disassembling threaded fasteners which have been in service for several years due to additional debris from local oxidation, foreign contaminants, and the breakdown, seepage, and removal of assembly lubricants.
The high ductility of commonly used machine screws can be considered a requisite characteristic for substantial material transfer and galling. Frictional heating is greatly related to the size, shape, and material properties of the plastic zones that surround the penetrating objects.
Correspondingly, brittle fractures rarely generate copious amounts of heat due to the small, transitory plastic zones. If the height of the protrusion grows larger than a critical threshold value, it may penetrate the brittle oxide layer of the complimentary mating surface. As a result, said protrusion could cause damage to the ductile bulk material on which the oxide layer originally formed, thus creating a region of plastic flow around said protrusion. Thus, the geometry, loading conditions, and relative motion of the protrusion govern the material flow, contact pressure, and thermal profile during sliding.
In the dynamic sliding contact of nut torqueing, increasing axial compressive force is proportionally equal to a rise in potential energy and thermal energy in the aforementioned localized system. Thus, the high loads and relative rotation associated with the torqueing of threaded nuts onto and off of threaded counterparts are particularly susceptible to galling.
Additionally, as the nut is turned further and sliding progresses, additional energy is supplied to
2 the system. Initially, there is limited energy loss in the system (contact zone), since heat conduction away from the contact zone is significantly inhibited by the relatively small cross sectional area for thermal transport, and correspondingly low conductance, on the system boundary. The result is a corresponding increase in energy density and temperature in the contact zone, and said energy accumulation can damage the contact surfaces and alter their plastic behavior. Furthermore, the combination of direct contact and plastically deforming flow fields can result in the constitution of a common plastic zone in which the high energy density, pressure, and temperature promote inter-surface bonding. Generally, this greatly increases apparent adhesion as well as the force needed for further nut advancement or removal. In some cases this can cause seizing of the nut onto the threaded component, and removal of said nut requires time-consuming or destructive techniques such as cutting of the nut or screw. Reducing or eliminating the compressive load between threads greatly reduces the likelihood of galling due to a decrease in localized potential energy and frictional heating in the system.
One possible method of galling prevention is the use of a tensioning system to stretch the bolt before turning the nut off. Examples of such tensioning systems include hydraulic bolt tensioners and hydraulic nuts. However, the use of such systems can be time intensive and often require additional hydraulic machinery to produce the requisite operating pressures. Furthermore, said tensioning methods involve temporarily increasing the compressive load on the bolted component during disassembly, which may be undesirable in some circumstances.
Examples of hydraulic tensioning devices can be found in United States patent numbers 4,998,453;
5,527,015; and 7,673,849.
Another possible method of galling prevention is the use of a plurality of jackbolts to mechanically tension and unload the main stud or bolt. Contrary to the previously described
One possible method of galling prevention is the use of a tensioning system to stretch the bolt before turning the nut off. Examples of such tensioning systems include hydraulic bolt tensioners and hydraulic nuts. However, the use of such systems can be time intensive and often require additional hydraulic machinery to produce the requisite operating pressures. Furthermore, said tensioning methods involve temporarily increasing the compressive load on the bolted component during disassembly, which may be undesirable in some circumstances.
Examples of hydraulic tensioning devices can be found in United States patent numbers 4,998,453;
5,527,015; and 7,673,849.
Another possible method of galling prevention is the use of a plurality of jackbolts to mechanically tension and unload the main stud or bolt. Contrary to the previously described
3 hydraulic tensioning systems, this method has the advantage of not necessitating an increase of the compressive load on the bolted components during disassembly.
However, this method of disassembly can be time intensive since multiple jackbolts must be unloaded for each main stud, often employing an iterative, step-wise unloading scheme.
Examples of multiple jackbolt devices can be found in United States patent numbers 3,618,994; 4,338,037; and 4,622,730.
An additional method of galling prevention is through the use of non-standard bolts or nuts. For example, United States patent number 8,206,072 describes a quick release nut which may be selectively disengaged from the fasteners threads.
However, it is often necessary to employ standardized fasteners in order to comply with industry guidelines. Thus, the use of a specialty quick-release nut may be undesirable.
There is therefore a need for a load-relief washer which obviates the aforementioned problems.
OBJECTS OF THE INVENTION
The present invention is directed to a load relief washer assembly for associated fasteners. The load relief washer assembly comprises:
a first body having a substantially annular shape with a through hole for an associated bolt or stud or threaded fastener to pass, and having a top surface and bottom surface, wherein the top surface has a plurality of stepped features or castellated features which form mating surfaces and a plurality of sliding planes;
a second body having a substantially annular shape with a through hole for the associated bolt or stud or threaded fastener to pass, and having a top surface and bottom surface, wherein the bottom surface has a plurality of stepped features or castellated features which form mating surfaces and a plurality of sliding planes;
wherein the stepped features or castellated features and the sliding planes of the first body and second body are complementary to one another; and whereby, in use, when the load relief washer is assembled with the associated bolt, stud, or threaded fastener, the first body may be rotated relative to the second
However, this method of disassembly can be time intensive since multiple jackbolts must be unloaded for each main stud, often employing an iterative, step-wise unloading scheme.
Examples of multiple jackbolt devices can be found in United States patent numbers 3,618,994; 4,338,037; and 4,622,730.
An additional method of galling prevention is through the use of non-standard bolts or nuts. For example, United States patent number 8,206,072 describes a quick release nut which may be selectively disengaged from the fasteners threads.
However, it is often necessary to employ standardized fasteners in order to comply with industry guidelines. Thus, the use of a specialty quick-release nut may be undesirable.
There is therefore a need for a load-relief washer which obviates the aforementioned problems.
OBJECTS OF THE INVENTION
The present invention is directed to a load relief washer assembly for associated fasteners. The load relief washer assembly comprises:
a first body having a substantially annular shape with a through hole for an associated bolt or stud or threaded fastener to pass, and having a top surface and bottom surface, wherein the top surface has a plurality of stepped features or castellated features which form mating surfaces and a plurality of sliding planes;
a second body having a substantially annular shape with a through hole for the associated bolt or stud or threaded fastener to pass, and having a top surface and bottom surface, wherein the bottom surface has a plurality of stepped features or castellated features which form mating surfaces and a plurality of sliding planes;
wherein the stepped features or castellated features and the sliding planes of the first body and second body are complementary to one another; and whereby, in use, when the load relief washer is assembled with the associated bolt, stud, or threaded fastener, the first body may be rotated relative to the second
4 body along the sliding planes, the stepped features or castellated features of the first body and the second body align allowing the first body and the second body to move toward one another which reduces an overall height of the load relief washer assembly; thereby reducing a tensile load to the associated bolt, stud, or threaded fastener.
According to a preferred embodiment, the first body and the second body may each include four of the stepped features or castellated features and plurality of sliding planes.
According to a preferred embodiment, the first body and the second body may each include eight of the stepped features or castellated features and a plurality of sliding planes.
According to a preferred embodiment, the substantially annular shape first body may be dodecagonal.
According to a preferred embodiment, the substantially annular shape first body may further comprise splines along an outer perimeter to assist with rotating the first body relative to the second body.
According to a preferred embodiment, the substantially annular shape first body may further comprise a plurality of transverse holes.
According to a preferred embodiment, the first body may further comprise a geometric feature on the surface opposite the surface having the stepped feature or castellated feature to aid in or inhibit rotation of the first body.
According to a preferred embodiment, the second body may further comprise a geometric feature on the surface opposite the surface having the stepped feature or castellated feature to aid in or inhibit rotation of the second body.
According to a preferred embodiment, the first body may further comprise a surface finish on the surface opposite the surface having the stepped feature or castellated feature to aid in or inhibit rotation of the first body.
4a According to a preferred embodiment, the second body may further comprise a surface finish on the surface opposite the surface having the stepped feature or castellated feature to aid in or inhibit rotation of the second body.
The invention is also directed to a method to activate a load relief washer assembly as defined herein, when a load relief washer is assembled with an associated bolt, stud, or threaded fastener. The method comprises the steps of:
a) aligning the stepped features or castellated features of the first body and the second body by rotating the first body relatively to the second body along the sliding planes; and b) allowing the first body and the second body to move toward one another for reducing the overall height of the load relief washer assembly thereby reducing the tensile load to the associated bolt, stud, or threaded fastener.
The invention is also directed to the use of the load washer assembly as defined herein, when a load relief washer is assembled with an associated bolt, stud, or threaded fastener for reducing the tensile load to the associated bolt, stud, or threaded fastener.
Accordingly, an object of this invention is the prevention of galling threaded features during the disassembly of bolted assemblies by reducing the load on said threaded features prior to disassembly.
Another object of this invention is the reduction of the load on the aforementioned threaded features without a corresponding increase of the axial tensile bolt load.
An additional object of the invention is to increase the speed of disassembly of bolted assemblies by eliminating the need for hydraulic machinery and the slow process of tensioning.
An additional object of the invention is to allow the use of industry standard threaded 4b fasteners such as threaded rods, bolts, studs, or nuts.
Another object of the invention is to increase the speed of the unloading process of bolted assemblies by requiring only a partial rotation of one part of the washer to remove the bolt load.
Other objects and advantages of the present invention will become obvious to the reader upon an understanding of the illustrative embodiments about to be described or will be indicated in the claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
BRIEF SUMMARY OF THE INVENTION
To attain these and other objects which will become more apparent as the description proceeds according to one aspect of the present invention, there is provided a load-relief washer for threaded fasteners.
More specifically, in accordance with the present invention, there is provided a load relief washer assembly for threaded fasteners (FIGS. 1 to 13) comprising a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features (4) which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2). The lower washer (1) and the upper washer (2) each include a hole (5) in their body through which a main bolt or stud may pass.
There is also provided a load relief washer assembly (FIGS. 14 to 19) combined with a threaded bolt (9) with an integrated bolt head (7) and a threaded nut (8) to clamp two work pieces (6) together. The load relief washer assembly comprises a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features (4) which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2). The lower washer (1) and the upper washer (2) each include a hole (5) in their body through which the main bolt (9) passes. The tensile load in the main bolt (9) acts through the top work piece (6) and the nut (8) to compress the lower washer (1) and the upper washer (2) of the load relief washer assembly together.
To activate the load relief washer, the upper washer (2) is rotated relative to the lower washer (1), sliding along the mating surfaces (3). Once enough relative rotation between the lower washer (1) and the upper washer (2) is achieved, the complimentary stepped features (4) align, allowing the lower washer (1) and the upper washer (2) to move toward each other. Said movement creates a gap (10) between the upper washer (2) and the nut (8), thereby reducing the tensile load in the main bolt (9). The reduction of the tensile load in the bolt (9) corresponds to a reduction in the forces on the threaded features of the nut (8) and the main bolt (9); thus, the bolted assembly may be disassembled with minimal risk of galling.
There is also provided another embodiment of the load relief washer assembly (FIGS. 20 to 21) comprising a lower washer piece (11), an upper washer piece (12), sets of four complimentary stepped features (14) which comprise the mating surfaces of the lower washer (11) and the upper washer (12), and a plurality of sliding planes (13) created by the interface of the lower washer (11) and the upper washer (12).
There is provided another embodiment of the load relief washer assembly (FIG.
22) comprising a lower washer piece (15), an upper washer piece (16), 8 sets of complimentary stepped features (18) which comprise the mating surfaces of the lower washer (15) and the upper washer (16), and a plurality of sliding planes (17) created by the interface of the lower washer (15) and the upper washer (16).
There is provided another embodiment of the load relief washer assembly (FIGS.
23 to 25) comprising a lower washer piece (19), an upper washer piece (20) with a dodecagonal feature, a plurality of complimentary stepped features (22) which comprise the mating surfaces of the lower washer (19) and the upper washer (20), and a plurality of sliding planes (21) created by the interface of the lower washer (11) and the upper washer (12).
There is provided another embodiment of the load relief washer assembly (FIGS.
26 to 28) comprising a lower washer piece (23), an upper washer piece (24) with a splined feature (25), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (23) and the upper washer (24), and a plurality of sliding planes created by the interface of the lower washer (23) and the upper washer (24).
There is provided another embodiment of the load relief washer assembly (FIGS.
29 to 30) comprising a lower washer piece (26), an upper washer piece (27) with a plurality of transverse holes (28), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (26) and the upper washer (27), and a plurality of sliding planes created by the interface of the lower washer (26) and the upper washer (27).
There is also provided an embodiment with multiple load relief washer assemblies (FIGS.
31 to 32) combined with threaded bolts (30) and threaded nuts (8) to clamp common flanges (29) together. The load relief washer assemblies each comprise of a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes created by the interface of the lower washer (1) and the upper washer (2). The lower washer (1) and the upper washer (2) each include a hole in their body through which a main bolt or stud may pass.
Other aspects and advantages will be more readily apparent as the present invention becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like elements throughout the figures.
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a top isometric view showing the load relief washer assembly according to an embodiment of the present invention.
FIG. 2 is a bottom isometric view of FIG. 1 showing the stepped features.
FIG. 3 is a side view of FIG. 1 showing the alignment of various parts.
FIG. 4 is a bottom view of FIG. 1 showing the hole through which the main stud or bolt may pass.
FIG. 5 is a bottom isometric view of FIG. 1 with the bottom washer removed showing the top washer.
FIG. 6 is a side view of FIG. 1 with the bottom washer removed showing the stepped features of the top washer.
FIG. 7 is a bottom view of FIG. 1 with the bottom washer removed showing the layout of the top washer.
FIG. 8 is a top isometric view of FIG. 1 with the top washer removed showing the bottom washer.
FIG. 9 is a bottom isometric view of FIG. 1 with the top washer removed showing the flat surface of the bottom washer.
FIG. 10 is a side view of FIG. 1 with the top washer removed showing the stepped features of the bottom washer.
FIG. 11 is a top isometric view showing the load relief washer assembly in the activated position according to an embodiment of the present invention.
FIG. 12 is a bottom isometric view of FIG. 11 showing the stepped features.
FIG. 13 is a side view of FIG. 11 showing the alignment of various parts.
FIG. 14 is an isometric view of a load relief washer with a bolted assembly including a headed bolt, a nut, and two clamped work pieces.
FIG. 15 is a side view of FIG. 14 showing a load relief washer with a bolted assembly including a headed bolt, a nut, and two clamped work pieces.
FIG. 16 is a full section view of FIG. 14 showing a load relief washer with a bolted assembly including a headed bolt, a nut, and two clamped work pieces.
FIG. 17 is an isometric view of an activated load relief washer with a bolted assembly including a headed bolt, a nut, and two work pieces.
FIG. 18 is a side view of FIG. 17 showing an activated load relief washer with a headed bolt, a nut, two clamped work pieces, and a gap between the nut and top washer.
FIG. 19 is a full section view of FIG. 17 showing an activated load relief washer with a bolted assembly and a gap between the nut and top washer.
FIG. 20 is a top isometric view showing a load relief washer assembly according to an embodiment of the present invention with three step levels.
FIG. 21 is a bottom isometric view of FIG. 20 showing a load relief washer assembly with three step levels.
FIG. 22 is an isometric view showing a load relief washer assembly according to an embodiment of the present invention with 8 sets of stepped features.
FIG. 23 is a top isometric view showing a load relief washer assembly according to an embodiment of the present invention with a dodecagonal feature on the top washer.
FIG. 24 is a bottom isometric view of FIG. 23 showing a load relief washer assembly with a dodecagonal feature on the top washer.
FIG. 25 is a top view of FIG. 23 showing a load relief washer assembly with a dodecagonal feature on the top washer.
FIG. 26 is a top isometric view showing a load relief washer assembly according to an embodiment of the present invention with a splined feature on the top washer.
FIG. 27 is a bottom isometric view of FIG. 26 showing a load relief washer assembly with a splined feature on the top washer.
FIG. 28 is a top view of FIG. 26 showing a load relief washer assembly with a splined feature on the top washer.
FIG. 29 is an isometric view showing a load relief washer assembly according to an embodiment of the present invention with transverse holes on the top washer.
FIG. 30 is a side view of FIG. 29 showing a load relief washer assembly with transverse holes on the top washer.
FIG. 31 is an isometric view of multiple load relief washers with a bolted assembly including headed bolts, nuts, and two clamped circular flanges.
FIG. 32 is a side view of FIG. 31 showing multiple load relief washers with a bolted assembly including headed bolts, nuts, and two clamped circular flanges.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the annexed figures, the preferred embodiments of the present invention will be herein described for indicative purposes and by no means represent limitations.
The figures and description attached to it are only intended to illustrate the idea of the invention. As to the details, the invention may vary within the scope of the claims. So, the size and shape of the tension relief system may be chosen to best fit the fastened assembly.
Also, as used hereinabove and hereinafter, the term "stud" generally refers to stud, bolt, rod and other similarly shaped fasteners used in securing assemblies.
In accordance with the present invention, there is provided a load relief washer assembly for threaded fasteners (FIGS. 1 to 19) comprising a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features (4) which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2). The lower washer (1) and the upper washer (2) each include a hole (5) in their body through which a main bolt or stud may pass.
A first embodiment of the present invention is best shown in FIGS. 1 to 3 and FIGS. 13 to 19. Its components comprise a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features (4) which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2). A threaded bolt (9) passes through holes (5) in the bodies of the lower washer (1) and the upper washer (2) and mates with a threaded nut (8) to clamp two work pieces (6) together. The stud (9) can pass through holes in the two work pieces (6) wherein the stud (9) can have an integral hex head (7) (see FIGS. 14 to 19) to allow it to be turned into place using external means, such as a hex socket. Alternatively, the stud can pass through holes in the two work pieces (6) and thread into a standard nut under the bottom work piece (6), or the stud (9) can be threaded into the bottom work piece (6).
The tensile load in the main bolt (9) clamps the load relief washer assembly and the work pieces (6) together, thereby making the load relief washer part of the bolted assembly. The nut (8) bears down on the upper washer (2), and the top work piece (6) similarly compresses the lower washer (1). However, relative movement of the upper washer (2) and the lower washer (1) towards each other is inhibited by their raised, stepped features (4); thus, the tensile load in the main bolt (9) is transferred to the plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2).
To activate the load relief washer, the upper washer (2) is rotated relative to the lower washer (1), sliding along the mating surfaces (3). In this example, a hexagonal shaped feature is included to aid in achieving said rotation though external means, such as a hex socket. Once enough relative rotation between the lower washer (1) and the upper washer (2) is achieved, the complimentary stepped features (4) align, allowing the lower washer (1) and the upper washer (2) to move toward each other. As the overall thickness of the bolted assembly is reduced, bolt stretch of the main stud (9) is alleviated and the tensile load lessens. If necessary, the height of the bolted assembly can be reduced past the point of removing stretch of the main stud (9), thereby creating a gap (10) between the upper washer (2) and the nut (8). The reduction of the tensile load in the bolt (9) corresponds to a reduction in the forces on the threaded features of the nut (8) and the main bolt (9); thus, the bolted assembly may be disassembled with minimal risk of galling.
It is to be understood that even though a stud (9) with an integral head (7) has been shown, the use of other types of studs and other types of mating techniques between the studs and work pieces (6) are also contemplated. For example, the mating of the stud (9) with the lower work piece (6) could be effected with a normal threaded nut which is threaded on a stud until it abuts on and mates with the lower work piece (6). Therefore, the present invention is not limited to a particular mating technique between the stud (9) and work pieces (6).
In another embodiment, multiple instances of the present invention are shown installed on the face of a circular flange (FIGS. 31 to 32). The stud bolts (30) are inserted through the lower washers (1), upper washers (2), threaded nuts (8), and the corresponding flanges (29) that are mating together.
There is provided another embodiment of the load relief washer assembly (FIGS.
20 to 21) comprising a lower washer piece (11), an upper washer piece (12), sets of four complimentary stepped features (14) which comprise the mating surfaces of the lower washer (11) and the upper washer (12), and a plurality of sliding planes (13) created by the interface of the lower washer (11) and the upper washer (12). The greater number of stepped features (14) allows activation to be achieved with less rotation of the lower washer (11) and the upper washer (12).
There is provided another embodiment of the load relief washer assembly (FIG.
22) comprising a lower washer piece (15), an upper washer piece (16), 8 sets of complimentary stepped features (18) which comprise the mating surfaces of the lower washer (15) and the upper washer (16), and a plurality of sliding planes (17) created by the interface of the lower washer (15) and the upper washer (16). The greater number of sets of complimentary stepped features (18) allows activation to be achieved with less rotation of the lower washer (15) and the upper washer (16) and can change the load distribution.
Also, it is to be understood that even though select step-like features have been shown, the use of other types and shapes of the steps (4) are also contemplated. For example, said features could be castellated, slightly angled, or linear rather than annular.
Therefore, the present invention is not limited to the particular type, shape, or number of the steps (4).
There is provided another embodiment of the load relief washer assembly (FIGS.
23 to 25) comprising a lower washer piece (19), an upper washer piece (20) with a dodecagonal feature, a plurality of complimentary stepped features (22) which comprise the mating surfaces of the lower washer (19) and the upper washer (20), and a plurality of sliding planes (21) created by the interface of the lower washer (11) and the upper washer (12). The dodecagonal feature is included to aid in achieving relative rotation of the lower washer (11) and the upper washer (12) though external means, such as a 12-point socket.
There is provided another embodiment of the load relief washer assembly (FIGS.
26 to 28) comprising a lower washer piece (23), an upper washer piece (24) with a splined feature (25), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (23) and the upper washer (24), and a plurality of sliding planes created by the interface of the lower washer (23) and the upper washer (24). The splined feature (25) is included to aid in achieving relative rotation of the lower washer (23) and the upper washer (24) though external means, such as a splined socket.
There is provided another embodiment of the load relief washer assembly (FIGS.
29 to 30) comprising a lower washer piece (26), an upper washer piece (27) with a plurality of transverse holes (28), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (26) and the upper washer (27), and a plurality of sliding planes created by the interface of the lower washer (26) and the upper washer (27).
The transverse holes (28) are included to aid in achieving relative rotation of the lower washer (26) and the upper washer (27) though external means, such as a spanner wrench or tommy wrench.
Also, it is to be understood that even though hexagonal and other select features have been shown to aid in activation of the device, the use of other types of aids are also contemplated. For example, activation could be aided by rectangular, toothed, gear-like, or roughed features. Additionally, no supplementary activation aiding feature is necessary.
Therefore, the present invention is not limited to a particular feature to aid in achieving relative rotation of the lower washer (1) and the upper washer (2).
Obviously, even if only some shapes of load relief washer assemblies have been shown and described, the skilled addressee will understand that the lower washer (1) and the upper washer (2) of the present invention could be provided in a variety of shapes and sizes according to the specific needs of a specific bolted assembly.
Thus, although preferred embodiments of the invention have been described in detail herein and illustrated in the accompanying figures, it is to be understood that the invention is not limited to these precise embodiments and that various changes and modifications may be effected therein without departing from the scope of the present invention.
According to a preferred embodiment, the first body and the second body may each include four of the stepped features or castellated features and plurality of sliding planes.
According to a preferred embodiment, the first body and the second body may each include eight of the stepped features or castellated features and a plurality of sliding planes.
According to a preferred embodiment, the substantially annular shape first body may be dodecagonal.
According to a preferred embodiment, the substantially annular shape first body may further comprise splines along an outer perimeter to assist with rotating the first body relative to the second body.
According to a preferred embodiment, the substantially annular shape first body may further comprise a plurality of transverse holes.
According to a preferred embodiment, the first body may further comprise a geometric feature on the surface opposite the surface having the stepped feature or castellated feature to aid in or inhibit rotation of the first body.
According to a preferred embodiment, the second body may further comprise a geometric feature on the surface opposite the surface having the stepped feature or castellated feature to aid in or inhibit rotation of the second body.
According to a preferred embodiment, the first body may further comprise a surface finish on the surface opposite the surface having the stepped feature or castellated feature to aid in or inhibit rotation of the first body.
4a According to a preferred embodiment, the second body may further comprise a surface finish on the surface opposite the surface having the stepped feature or castellated feature to aid in or inhibit rotation of the second body.
The invention is also directed to a method to activate a load relief washer assembly as defined herein, when a load relief washer is assembled with an associated bolt, stud, or threaded fastener. The method comprises the steps of:
a) aligning the stepped features or castellated features of the first body and the second body by rotating the first body relatively to the second body along the sliding planes; and b) allowing the first body and the second body to move toward one another for reducing the overall height of the load relief washer assembly thereby reducing the tensile load to the associated bolt, stud, or threaded fastener.
The invention is also directed to the use of the load washer assembly as defined herein, when a load relief washer is assembled with an associated bolt, stud, or threaded fastener for reducing the tensile load to the associated bolt, stud, or threaded fastener.
Accordingly, an object of this invention is the prevention of galling threaded features during the disassembly of bolted assemblies by reducing the load on said threaded features prior to disassembly.
Another object of this invention is the reduction of the load on the aforementioned threaded features without a corresponding increase of the axial tensile bolt load.
An additional object of the invention is to increase the speed of disassembly of bolted assemblies by eliminating the need for hydraulic machinery and the slow process of tensioning.
An additional object of the invention is to allow the use of industry standard threaded 4b fasteners such as threaded rods, bolts, studs, or nuts.
Another object of the invention is to increase the speed of the unloading process of bolted assemblies by requiring only a partial rotation of one part of the washer to remove the bolt load.
Other objects and advantages of the present invention will become obvious to the reader upon an understanding of the illustrative embodiments about to be described or will be indicated in the claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
BRIEF SUMMARY OF THE INVENTION
To attain these and other objects which will become more apparent as the description proceeds according to one aspect of the present invention, there is provided a load-relief washer for threaded fasteners.
More specifically, in accordance with the present invention, there is provided a load relief washer assembly for threaded fasteners (FIGS. 1 to 13) comprising a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features (4) which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2). The lower washer (1) and the upper washer (2) each include a hole (5) in their body through which a main bolt or stud may pass.
There is also provided a load relief washer assembly (FIGS. 14 to 19) combined with a threaded bolt (9) with an integrated bolt head (7) and a threaded nut (8) to clamp two work pieces (6) together. The load relief washer assembly comprises a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features (4) which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2). The lower washer (1) and the upper washer (2) each include a hole (5) in their body through which the main bolt (9) passes. The tensile load in the main bolt (9) acts through the top work piece (6) and the nut (8) to compress the lower washer (1) and the upper washer (2) of the load relief washer assembly together.
To activate the load relief washer, the upper washer (2) is rotated relative to the lower washer (1), sliding along the mating surfaces (3). Once enough relative rotation between the lower washer (1) and the upper washer (2) is achieved, the complimentary stepped features (4) align, allowing the lower washer (1) and the upper washer (2) to move toward each other. Said movement creates a gap (10) between the upper washer (2) and the nut (8), thereby reducing the tensile load in the main bolt (9). The reduction of the tensile load in the bolt (9) corresponds to a reduction in the forces on the threaded features of the nut (8) and the main bolt (9); thus, the bolted assembly may be disassembled with minimal risk of galling.
There is also provided another embodiment of the load relief washer assembly (FIGS. 20 to 21) comprising a lower washer piece (11), an upper washer piece (12), sets of four complimentary stepped features (14) which comprise the mating surfaces of the lower washer (11) and the upper washer (12), and a plurality of sliding planes (13) created by the interface of the lower washer (11) and the upper washer (12).
There is provided another embodiment of the load relief washer assembly (FIG.
22) comprising a lower washer piece (15), an upper washer piece (16), 8 sets of complimentary stepped features (18) which comprise the mating surfaces of the lower washer (15) and the upper washer (16), and a plurality of sliding planes (17) created by the interface of the lower washer (15) and the upper washer (16).
There is provided another embodiment of the load relief washer assembly (FIGS.
23 to 25) comprising a lower washer piece (19), an upper washer piece (20) with a dodecagonal feature, a plurality of complimentary stepped features (22) which comprise the mating surfaces of the lower washer (19) and the upper washer (20), and a plurality of sliding planes (21) created by the interface of the lower washer (11) and the upper washer (12).
There is provided another embodiment of the load relief washer assembly (FIGS.
26 to 28) comprising a lower washer piece (23), an upper washer piece (24) with a splined feature (25), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (23) and the upper washer (24), and a plurality of sliding planes created by the interface of the lower washer (23) and the upper washer (24).
There is provided another embodiment of the load relief washer assembly (FIGS.
29 to 30) comprising a lower washer piece (26), an upper washer piece (27) with a plurality of transverse holes (28), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (26) and the upper washer (27), and a plurality of sliding planes created by the interface of the lower washer (26) and the upper washer (27).
There is also provided an embodiment with multiple load relief washer assemblies (FIGS.
31 to 32) combined with threaded bolts (30) and threaded nuts (8) to clamp common flanges (29) together. The load relief washer assemblies each comprise of a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes created by the interface of the lower washer (1) and the upper washer (2). The lower washer (1) and the upper washer (2) each include a hole in their body through which a main bolt or stud may pass.
Other aspects and advantages will be more readily apparent as the present invention becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like elements throughout the figures.
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a top isometric view showing the load relief washer assembly according to an embodiment of the present invention.
FIG. 2 is a bottom isometric view of FIG. 1 showing the stepped features.
FIG. 3 is a side view of FIG. 1 showing the alignment of various parts.
FIG. 4 is a bottom view of FIG. 1 showing the hole through which the main stud or bolt may pass.
FIG. 5 is a bottom isometric view of FIG. 1 with the bottom washer removed showing the top washer.
FIG. 6 is a side view of FIG. 1 with the bottom washer removed showing the stepped features of the top washer.
FIG. 7 is a bottom view of FIG. 1 with the bottom washer removed showing the layout of the top washer.
FIG. 8 is a top isometric view of FIG. 1 with the top washer removed showing the bottom washer.
FIG. 9 is a bottom isometric view of FIG. 1 with the top washer removed showing the flat surface of the bottom washer.
FIG. 10 is a side view of FIG. 1 with the top washer removed showing the stepped features of the bottom washer.
FIG. 11 is a top isometric view showing the load relief washer assembly in the activated position according to an embodiment of the present invention.
FIG. 12 is a bottom isometric view of FIG. 11 showing the stepped features.
FIG. 13 is a side view of FIG. 11 showing the alignment of various parts.
FIG. 14 is an isometric view of a load relief washer with a bolted assembly including a headed bolt, a nut, and two clamped work pieces.
FIG. 15 is a side view of FIG. 14 showing a load relief washer with a bolted assembly including a headed bolt, a nut, and two clamped work pieces.
FIG. 16 is a full section view of FIG. 14 showing a load relief washer with a bolted assembly including a headed bolt, a nut, and two clamped work pieces.
FIG. 17 is an isometric view of an activated load relief washer with a bolted assembly including a headed bolt, a nut, and two work pieces.
FIG. 18 is a side view of FIG. 17 showing an activated load relief washer with a headed bolt, a nut, two clamped work pieces, and a gap between the nut and top washer.
FIG. 19 is a full section view of FIG. 17 showing an activated load relief washer with a bolted assembly and a gap between the nut and top washer.
FIG. 20 is a top isometric view showing a load relief washer assembly according to an embodiment of the present invention with three step levels.
FIG. 21 is a bottom isometric view of FIG. 20 showing a load relief washer assembly with three step levels.
FIG. 22 is an isometric view showing a load relief washer assembly according to an embodiment of the present invention with 8 sets of stepped features.
FIG. 23 is a top isometric view showing a load relief washer assembly according to an embodiment of the present invention with a dodecagonal feature on the top washer.
FIG. 24 is a bottom isometric view of FIG. 23 showing a load relief washer assembly with a dodecagonal feature on the top washer.
FIG. 25 is a top view of FIG. 23 showing a load relief washer assembly with a dodecagonal feature on the top washer.
FIG. 26 is a top isometric view showing a load relief washer assembly according to an embodiment of the present invention with a splined feature on the top washer.
FIG. 27 is a bottom isometric view of FIG. 26 showing a load relief washer assembly with a splined feature on the top washer.
FIG. 28 is a top view of FIG. 26 showing a load relief washer assembly with a splined feature on the top washer.
FIG. 29 is an isometric view showing a load relief washer assembly according to an embodiment of the present invention with transverse holes on the top washer.
FIG. 30 is a side view of FIG. 29 showing a load relief washer assembly with transverse holes on the top washer.
FIG. 31 is an isometric view of multiple load relief washers with a bolted assembly including headed bolts, nuts, and two clamped circular flanges.
FIG. 32 is a side view of FIG. 31 showing multiple load relief washers with a bolted assembly including headed bolts, nuts, and two clamped circular flanges.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the annexed figures, the preferred embodiments of the present invention will be herein described for indicative purposes and by no means represent limitations.
The figures and description attached to it are only intended to illustrate the idea of the invention. As to the details, the invention may vary within the scope of the claims. So, the size and shape of the tension relief system may be chosen to best fit the fastened assembly.
Also, as used hereinabove and hereinafter, the term "stud" generally refers to stud, bolt, rod and other similarly shaped fasteners used in securing assemblies.
In accordance with the present invention, there is provided a load relief washer assembly for threaded fasteners (FIGS. 1 to 19) comprising a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features (4) which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2). The lower washer (1) and the upper washer (2) each include a hole (5) in their body through which a main bolt or stud may pass.
A first embodiment of the present invention is best shown in FIGS. 1 to 3 and FIGS. 13 to 19. Its components comprise a lower washer piece (1), an upper washer piece (2), a plurality of complimentary stepped features (4) which comprise the mating surfaces of the lower washer (1) and the upper washer (2), and a plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2). A threaded bolt (9) passes through holes (5) in the bodies of the lower washer (1) and the upper washer (2) and mates with a threaded nut (8) to clamp two work pieces (6) together. The stud (9) can pass through holes in the two work pieces (6) wherein the stud (9) can have an integral hex head (7) (see FIGS. 14 to 19) to allow it to be turned into place using external means, such as a hex socket. Alternatively, the stud can pass through holes in the two work pieces (6) and thread into a standard nut under the bottom work piece (6), or the stud (9) can be threaded into the bottom work piece (6).
The tensile load in the main bolt (9) clamps the load relief washer assembly and the work pieces (6) together, thereby making the load relief washer part of the bolted assembly. The nut (8) bears down on the upper washer (2), and the top work piece (6) similarly compresses the lower washer (1). However, relative movement of the upper washer (2) and the lower washer (1) towards each other is inhibited by their raised, stepped features (4); thus, the tensile load in the main bolt (9) is transferred to the plurality of sliding planes (3) created by the interface of the lower washer (1) and the upper washer (2).
To activate the load relief washer, the upper washer (2) is rotated relative to the lower washer (1), sliding along the mating surfaces (3). In this example, a hexagonal shaped feature is included to aid in achieving said rotation though external means, such as a hex socket. Once enough relative rotation between the lower washer (1) and the upper washer (2) is achieved, the complimentary stepped features (4) align, allowing the lower washer (1) and the upper washer (2) to move toward each other. As the overall thickness of the bolted assembly is reduced, bolt stretch of the main stud (9) is alleviated and the tensile load lessens. If necessary, the height of the bolted assembly can be reduced past the point of removing stretch of the main stud (9), thereby creating a gap (10) between the upper washer (2) and the nut (8). The reduction of the tensile load in the bolt (9) corresponds to a reduction in the forces on the threaded features of the nut (8) and the main bolt (9); thus, the bolted assembly may be disassembled with minimal risk of galling.
It is to be understood that even though a stud (9) with an integral head (7) has been shown, the use of other types of studs and other types of mating techniques between the studs and work pieces (6) are also contemplated. For example, the mating of the stud (9) with the lower work piece (6) could be effected with a normal threaded nut which is threaded on a stud until it abuts on and mates with the lower work piece (6). Therefore, the present invention is not limited to a particular mating technique between the stud (9) and work pieces (6).
In another embodiment, multiple instances of the present invention are shown installed on the face of a circular flange (FIGS. 31 to 32). The stud bolts (30) are inserted through the lower washers (1), upper washers (2), threaded nuts (8), and the corresponding flanges (29) that are mating together.
There is provided another embodiment of the load relief washer assembly (FIGS.
20 to 21) comprising a lower washer piece (11), an upper washer piece (12), sets of four complimentary stepped features (14) which comprise the mating surfaces of the lower washer (11) and the upper washer (12), and a plurality of sliding planes (13) created by the interface of the lower washer (11) and the upper washer (12). The greater number of stepped features (14) allows activation to be achieved with less rotation of the lower washer (11) and the upper washer (12).
There is provided another embodiment of the load relief washer assembly (FIG.
22) comprising a lower washer piece (15), an upper washer piece (16), 8 sets of complimentary stepped features (18) which comprise the mating surfaces of the lower washer (15) and the upper washer (16), and a plurality of sliding planes (17) created by the interface of the lower washer (15) and the upper washer (16). The greater number of sets of complimentary stepped features (18) allows activation to be achieved with less rotation of the lower washer (15) and the upper washer (16) and can change the load distribution.
Also, it is to be understood that even though select step-like features have been shown, the use of other types and shapes of the steps (4) are also contemplated. For example, said features could be castellated, slightly angled, or linear rather than annular.
Therefore, the present invention is not limited to the particular type, shape, or number of the steps (4).
There is provided another embodiment of the load relief washer assembly (FIGS.
23 to 25) comprising a lower washer piece (19), an upper washer piece (20) with a dodecagonal feature, a plurality of complimentary stepped features (22) which comprise the mating surfaces of the lower washer (19) and the upper washer (20), and a plurality of sliding planes (21) created by the interface of the lower washer (11) and the upper washer (12). The dodecagonal feature is included to aid in achieving relative rotation of the lower washer (11) and the upper washer (12) though external means, such as a 12-point socket.
There is provided another embodiment of the load relief washer assembly (FIGS.
26 to 28) comprising a lower washer piece (23), an upper washer piece (24) with a splined feature (25), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (23) and the upper washer (24), and a plurality of sliding planes created by the interface of the lower washer (23) and the upper washer (24). The splined feature (25) is included to aid in achieving relative rotation of the lower washer (23) and the upper washer (24) though external means, such as a splined socket.
There is provided another embodiment of the load relief washer assembly (FIGS.
29 to 30) comprising a lower washer piece (26), an upper washer piece (27) with a plurality of transverse holes (28), a plurality of complimentary stepped features which comprise the mating surfaces of the lower washer (26) and the upper washer (27), and a plurality of sliding planes created by the interface of the lower washer (26) and the upper washer (27).
The transverse holes (28) are included to aid in achieving relative rotation of the lower washer (26) and the upper washer (27) though external means, such as a spanner wrench or tommy wrench.
Also, it is to be understood that even though hexagonal and other select features have been shown to aid in activation of the device, the use of other types of aids are also contemplated. For example, activation could be aided by rectangular, toothed, gear-like, or roughed features. Additionally, no supplementary activation aiding feature is necessary.
Therefore, the present invention is not limited to a particular feature to aid in achieving relative rotation of the lower washer (1) and the upper washer (2).
Obviously, even if only some shapes of load relief washer assemblies have been shown and described, the skilled addressee will understand that the lower washer (1) and the upper washer (2) of the present invention could be provided in a variety of shapes and sizes according to the specific needs of a specific bolted assembly.
Thus, although preferred embodiments of the invention have been described in detail herein and illustrated in the accompanying figures, it is to be understood that the invention is not limited to these precise embodiments and that various changes and modifications may be effected therein without departing from the scope of the present invention.
Claims (16)
1. A load relief washer assembly for associated fasteners, comprising:
a first body having a substantially annular shape with a through hole for an associated bolt or stud or threaded fastener to pass, and having a top surface and bottom surface, wherein the top surface has a plurality of stepped features or castellated features which form mating surfaces and a plurality of sliding planes;
a second body having a substantially annular shape with a through hole for the associated bolt or stud or threaded fastener to pass, and having a top surface and bottom surface, wherein the bottom surface has a plurality of stepped features or castellated features which form mating surfaces and a plurality of sliding planes;
wherein the stepped features or castellated features and the sliding planes of the first body and second body are complementary to one another; and whereby, in use, when the load relief washer is assembled with the associated bolt, stud, or threaded fastener, the first body may be rotated relative to the second body along the sliding planes, the stepped features or castellated features of the first body and the second body align allowing the first body and the second body to move toward one another which reduces an overall height of the load relief washer assembly;
thereby reducing a tensile load to the associated bolt, stud, or threaded fastener.
a first body having a substantially annular shape with a through hole for an associated bolt or stud or threaded fastener to pass, and having a top surface and bottom surface, wherein the top surface has a plurality of stepped features or castellated features which form mating surfaces and a plurality of sliding planes;
a second body having a substantially annular shape with a through hole for the associated bolt or stud or threaded fastener to pass, and having a top surface and bottom surface, wherein the bottom surface has a plurality of stepped features or castellated features which form mating surfaces and a plurality of sliding planes;
wherein the stepped features or castellated features and the sliding planes of the first body and second body are complementary to one another; and whereby, in use, when the load relief washer is assembled with the associated bolt, stud, or threaded fastener, the first body may be rotated relative to the second body along the sliding planes, the stepped features or castellated features of the first body and the second body align allowing the first body and the second body to move toward one another which reduces an overall height of the load relief washer assembly;
thereby reducing a tensile load to the associated bolt, stud, or threaded fastener.
2. The assembly as claimed in claim 1, wherein the first body and the second body each include four of the stepped features or castellated features and plurality of sliding planes.
3. The assembly as claimed in claim 1, wherein the first body and the second body each include eight of the stepped features or castellated features and a plurality of sliding planes.
4. The assembly as claimed in any one of claims 1 to 3, wherein the substantially annular shape first body is dodecagonal.
5. The assembly as claimed in any one of claims 1 to 4, wherein the substantially annular shape first body further comprises splines along an outer perimeter to assist with rotating the first body relative to the second body.
6. The assembly as claimed in any one of claims 1 to 5, wherein the substantially annular shape first body further comprises a plurality of transverse holes.
7. The assembly as claimed in any one of claims 1 to 6, wherein the first body further comprises a geometric feature on the surface opposite the surface having the stepped feature or castellated feature to aid in rotation of the first body.
8. The assembly as claimed in any one of claims 1 to 7, wherein the second body further comprises a geometric feature on the surface opposite the surface having the stepped feature or castellated feature to aid in rotation of the second body.
9. The assembly as claimed in any one of claims 1 to 6, wherein the first body further comprises a surface finish on the surface opposite the surface having the stepped feature or castellated feature to aid in rotation of the first body.
10. The assembly as claimed in any one of claims 1 to 6 and 9, wherein the second body further comprises a surface finish on the surface opposite the surface having the stepped feature or castellated feature to aid in rotation of the second body.
11. The assembly as claimed in any one of claims 1 to 6, wherein the first body further comprises a geometric feature on the surface opposite the surface having the stepped feature or castellated feature to inhibit rotation of the first body.
12. The assembly as claimed in any one of claims 1 to 6 and 11, wherein the second body further comprises a geometric feature on the surface opposite the surface having the stepped feature or castellated feature to inhibit rotation of the second body.
13. The assembly as claimed in any one of claims 1 to 6, wherein the first body further comprises a surface finish on the surface opposite the surface having the stepped feature or castellated feature to inhibit rotation of the first body.
14. The assembly as claimed in any one of claims 1 to 6 and 13, wherein the second body further comprises a surface finish on the surface opposite the surface having the stepped feature or castellated feature to inhibit rotation of the second body.
15. A method to activate a load relief washer assembly as defined in any one of claims 1 to 14 when a load relief washer is assembled with an associated bolt, stud, or threaded fastener, the method comprising the steps of:
a) aligning the stepped features or castellated features of the first body and the second body by rotating the first body relatively to the second body along the sliding planes; and b) allowing the first body and the second body to move toward one another for reducing the overall height of the load relief washer assembly thereby reducing the tensile load to the associated bolt, stud, or threaded fastener.
a) aligning the stepped features or castellated features of the first body and the second body by rotating the first body relatively to the second body along the sliding planes; and b) allowing the first body and the second body to move toward one another for reducing the overall height of the load relief washer assembly thereby reducing the tensile load to the associated bolt, stud, or threaded fastener.
16. Use of the load washer assembly as defined in any one of claims 1 to 14 when a load relief washer is assembled with an associated bolt, stud, or threaded fastener for reducing the tensile load to the associated bolt, stud, or threaded fastener.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2794673A CA2794673C (en) | 2012-11-02 | 2012-11-02 | Load-relief washer for threaded fasteners therefor |
| CN201380048895.XA CN104641126B (en) | 2012-07-23 | 2013-07-22 | Off-load gasket assembly for threaded fastener |
| EP13745272.8A EP2875245B1 (en) | 2012-07-23 | 2013-07-22 | Load-relief washer assembly for threaded fasteners |
| JP2015524361A JP6336445B2 (en) | 2012-07-23 | 2013-07-22 | Load relief washer assembly for threaded fasteners |
| PCT/US2013/051470 WO2014018443A1 (en) | 2012-07-23 | 2013-07-22 | Load-relief washer assembly for threaded fasteners |
| MX2015001155A MX351532B (en) | 2012-07-23 | 2013-07-22 | Load-relief washer assembly for threaded fasteners. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2794673A CA2794673C (en) | 2012-11-02 | 2012-11-02 | Load-relief washer for threaded fasteners therefor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2794673A1 CA2794673A1 (en) | 2014-05-02 |
| CA2794673C true CA2794673C (en) | 2016-06-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2794673A Active CA2794673C (en) | 2012-07-23 | 2012-11-02 | Load-relief washer for threaded fasteners therefor |
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| Country | Link |
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| CA (1) | CA2794673C (en) |
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| Publication number | Publication date |
|---|---|
| CA2794673A1 (en) | 2014-05-02 |
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