Composite gasket for force indication and looseness prevention

Abstract

The present invention relates to a composite washer (100) for force indication and prevention of fastener loosening. The composite gasket includes a top portion (120) having a circumferential extension about an axis, an elastic portion (130) having a circumferential extension about the axis, a base portion (140) having a circumferential extension about the axis, where the top portion, the elastic portion and the base portion are connected to each other, where the elastic portion is arranged between the top portion and the base portion, and where the elastic portion is arranged between the top portion and the base portion. Wherein there is a central opening (102) having an extension along the axis through the top portion, the resilient portion and the base portion. Further, the composite gasket is arranged in a primary state in which the elastic portion is visible at the lateral surface of the composite gasket, and wherein the composite gasket is arranged in a secondary state in which the elastic portion is visible at the lateral surface of the composite gasket. The elastic portion is compressed by the top portion and the base portion such that the elastic portion is hidden by at least one of the top portion and the base portion at a lateral surface (104) of the composite gasket. Accordingly, a composite washer is provided that indicates a tightening force on a fastener and resists loosening of the fastener.

Description

Technical Field

[0001] The present invention relates to the field of washers and in particular to washers for improving the tightening of fasteners such as bolts, nuts, screws or clamps. Background Art

[0002] Fasteners (such as bolts, screws, nuts or clamps) are widely used to mechanically connect or attach two or more objects together. In some cases, it is necessary to apply the fastener with a specific tightening force. If the tightening force is less than required, the fastener may loosen, which may lead to serious consequences. On the other hand, if the tightening force is higher than required, the excessive force applied to tighten the fastener may cause damage to the object connected by the fastener or the fastener itself. Nowadays, torque wrenches and screwdrivers with preset torque meters are intended to solve this problem by allowing users to control the tightening force applied. However, if such tools are used, it is a tedious process to tighten multiple fasteners with different tightening force requirements. In addition, many handheld tools are heavy and expensive, and may even become impractical for fasteners that require a large amount of tightening force. Even further, due to lack of space, it may be dangerous or even impossible to use handheld automated tools to tighten fasteners that are located in inaccessible or exposed places.

[0003] Furthermore, a fastener that is applied with exactly the required tightening force may accidentally loosen due to repeated forces or vibrations, which may cause the fastener to slowly loosen. Metal washers are often used to prevent loss of tightening force used to tighten the fastener. Accordingly, there is a need in the art to ensure that a fastener is applied with the correct tightening force while also ensuring that the fastener remains securely tightened. Summary of the invention

[0004] At least some of the above mentioned disadvantages are overcome by the present disclosure according to the independent claims. Preferred embodiments are set out in the dependent claims.

[0005] According to one aspect of the present disclosure, there is provided a composite washer for force indication and preventing fastener loosening, the composite washer comprising a top portion having a circumferential extension around an axis, a resilient portion having a circumferential extension around the axis, a base portion having a circumferential extension around the axis, wherein the top portion, the resilient portion and the base portion are connected to each other, wherein the resilient portion is arranged between the top portion and the base portion, wherein there is a central opening having an extension extending along the axis through the top portion, the resilient portion and the base portion, wherein the composite washer is arranged in a primary state in which the resilient portion is visible at a lateral surface of the composite washer, and wherein the composite washer is arranged in a secondary state in which the resilient portion is compressed by the top portion and the base portion so that the resilient portion is hidden by at least one of the top portion and the base portion at the lateral surface of the composite washer.

[0006] The present disclosure is based on the recognition that the composite washer provided will provide a visual aid to the user, which indicates whether a sufficient amount of tightening force has been applied to tighten the fastener. This indication is shown in the following way: when the elastic portion is no longer visible at the lateral surface of the composite washer, a sufficient amount of tightening force has been applied. By changing the stiffness of the elastic portion (for example, by changing the shape of the elastic portion), the compression force required to compress the composite washer to its secondary state can be modified as required. This allows a plurality of composite washers each having a separate level of stiffness to be supplied for a plurality of fasteners each having a separate required tightening force. Thus, the user is able to quickly tighten a plurality of fasteners according to the individual requirements of the tightening force without using multiple tools and without adjusting any settings of a single tool, which is advantageous. Another advantage of the present invention is that when the composite washer is compressed to its secondary state, thereby indicating that a sufficient tightening force has been applied, the elastic portion is completely hidden at its lateral surface. Thus, the user will clearly recognize that no further force is required and thus minimize the risk of human error. In the secondary state of the composite washer, the top portion and the base portion do not necessarily have to reach direct contact to hide the elastic portion at the lateral surface of the composite washer. For example, the top portion and the base portion can overlap or be close enough to contact to hide the elastic portion so that it is not visible at the lateral surface of the composite washer. Another advantage of the present disclosure is that the elastic material will visually indicate whether the tightening force is loosened over time. The user who visually inspects the fastener will immediately recognize that the fastening element needs to be tightened by seeing the elastic portion at the lateral side of the composite washer. Thus, the composite washer according to the present disclosure enables a large number of fasteners to be checked quickly and safely. Even further, as a reaction when compressed, the elastic material presses against the top portion and the base portion. Therefore, the composite washer applies an expansion force toward the fastener and the fastener is toward the object being fastened. Thus, the friction between the fastening element and the object against which the fastening element is fastened is increased, which is conducive to improving the resistance of the fastening element to resist rotation. This is further conducive to reducing the risk of loosening the fastening element due to vibration from the load displacement on the fastening element. Thus, a composite washer is provided that indicates tightening force on a fastener and resists loosening of the fastener.

[0007] According to another embodiment, the elastic portion has a longitudinal extension along the axis from the upper portion of the elastic portion via the middle portion to the lower portion, wherein, when the elastic portion is not compressed, the first inner diameter at the upper portion is different from the second inner diameter at the middle portion. This provides that when the composite washer is compressed from its primary state to the secondary state, the elastic portion can be smoothly compressed. The risk of the elastic portion receiving an undesirable and potentially harmful tilting deformation during compression is thereby greatly reduced. This is advantageous for extending the life of the composite washer. Changing at least one of the first inner diameter or the second inner diameter of the upper portion and the middle portion can further enable the compression resistance of the elastic portion to be nonlinear. For example, the closer the composite washer is to its secondary state, the amount of additional tightening force required to compress the composite washer a specific distance can be increased. This can be beneficial when tightening the fastener to prevent the fastener from loosening after tightening.

[0008] According to another embodiment, the first inner diameter is smaller than the second inner diameter. This provides that the middle portion of the elastic part is thinner than at least one of the upper part and the lower part. This is advantageous for enabling the elastic part to deform uniformly when compressed by the top part and the base part. Further, it can reduce the risk of the elastic part being damaged due to clamping.

[0009] According to another embodiment, the elastic portion comprises a groove extending circumferentially around the inner surface of the elastic portion facing the axis. This provides that the deformation of the elastic portion is controlled by the groove, so that when the composite gasket is compressed from its primary state to its secondary state, the groove also helps to control the movement line of the top part and the base part. This is advantageous for promoting the alignment of the movement line with the direction of the axis.

[0010] According to another embodiment, the elastic part is in direct contact with the top part and the base part. This enables the user to modify the friction between the elastic part, the top part and the base part to a greater extent. If necessary, the part can be changed to have a high friction connection. This improves the ability of the part to withstand rotational movement relative to each other. This is beneficial for not producing rotational wear of the parts of the composite washer, thereby extending its life. Alternatively, the part can be changed to have a low friction connection so that the parts can rotate relative to each other around the axis. Further, the elastic part can be directly glued to at least one of the top part and the base part, which further helps to prevent disengagement due to internal rotation.

[0011] According to another embodiment, the elastic part is made of the material polyurethane. This provides many advantages. Polyurethane has great thermal stability. This is advantageous for ensuring that the mechanical properties of the elastic part are not significantly affected by temperature during the expected outdoor temperature range. Therefore, the user can rely on the accuracy of the composite gasket to correctly indicate the required tensioning force, regardless of the outdoor temperature. Polyurethane is further advantageous because it has great durability to chemicals, oils and water. Moreover, polyurethane is resistant to wear and external impact, allowing it to resist a large amount of force without permanent deformation. Polyurethane further has the advantage that it is easy to color and make transparent. It is also conceivable that the elastic material is EPDM rubber. It is advantageous to use EPDM rubber because it has great durability to UV radiation, chemicals and water. EPDM is further advantageous because it has great shock absorption characteristics. Even further, EPDM shows very small changes affected by temperature, making it suitable for use in composite gaskets used outdoors.

[0012] According to another embodiment, the elastic portion has a visually different color, such as red or green. This provides for the user to visually identify the elastic portion. This is advantageous for ensuring the visual load indication function of the composite gasket. It may be advantageous to use colors associated with meanings, red may for example indicate danger, while green may be used to indicate safety.

[0013] According to another embodiment, the elastic portion is fluorescent. This provides that the elastic portion emits light or any other electromagnetic radiation that has been absorbed from the light source. This is advantageous for facilitating the user to determine whether the elastic portion is visible at the lateral surface of the composite gasket. This is particularly advantageous during night time, as the visibility of the fluorescence is enhanced in the dark.

[0014] According to another embodiment, the resilient portion is glued to the top portion and the base portion. This provides for easy assembly of the composite gasket. It is further advantageous to create a uniform contact surface between the resilient portion, the top portion and the base portion.

[0015] According to another embodiment, the top portion comprises an outer top wall portion extending circumferentially around the axis and wherein the outer top wall portion has a longitudinal extension towards the base portion, wherein the base portion comprises an outer base wall portion extending circumferentially around the axis and wherein the outer base wall portion has a longitudinal extension towards the top portion. This provides that the top wall portion and the base wall portion can limit deformation of the elastic portion at its radially outer end. The top wall portion and the base wall portion can also serve as a protective surface for the composite gasket.

[0016] According to another embodiment, the outer top wall portion and the outer base wall portion are arranged to be separated in the primary state and to contact in the secondary state. This provides that the top wall portion and the base wall portion can stop the compression of the composite gasket. This is advantageous for preventing the elastic portion from receiving excessively high compression forces that cause damage. The composite gasket is preferably designed so that when the top wall portion and the base wall portion are placed in contact, a sufficient amount of tightening is applied. Further, when the composite gasket is compressed to its secondary state, the user applying the tightening force will immediately feel that the compression of the composite gasket is hindered because the composite gasket becomes stationary. Thus, the user knows that a sufficient amount of force has been applied. This is advantageous for avoiding applying too much tightening force to the fastener.

[0017] According to another embodiment, the outer top wall portion is arranged at an outer circumference of the top portion and wherein the outer base wall portion is arranged at an outer circumference of the base portion.

[0018] According to another embodiment, the top portion includes a top engagement portion, which engages with the elastic portion so that the connection between the elastic portion and the top portion is maintained, and wherein the base portion includes a base engagement portion, which engages with the elastic portion so that the connection between the elastic portion and the base portion is maintained. This provides that, except by the top engagement portion and the base engagement portion, the top portion, the elastic portion and the base portion do not need to be attached to each other by other means. In order to enable the top engagement portion and the base engagement portion to engage with the elastic portion, the elastic portion is preferably shaped so that the first inner diameter at its upper portion and the third inner diameter at its lower portion are less than the second inner diameter of its middle portion. The elastic portion can be, for example, C-shaped. The elastic portion with a C-shaped cross section can be arranged so that the top engagement portion engages with the upper portion of the C-shaped cross section, and the base engagement portion engages with the lower portion of the C-shaped cross section. The top engaging portion and the base engaging portion are preferably engaged with the resilient portion, such that the connection between the top portion, the resilient portion and the base portion is maintained when the composite washer is used according to its intended purpose. Further, the connection is preferably not strong enough to prevent the user from disassembling the composite washer when needed. It is further conceivable that if the top portion, the base portion and the resilient portion are attached to each other only by the top engaging portion and the base engaging portion, it may be desirable to enable the top portion, the base portion and the resilient portion to rotate independently relative to each other around an axis. To facilitate this, when the composite washer is in its primary state or secondary state, the surfaces of the top portion and the base portion that are in direct contact with the resilient portion are preferably smooth to produce a low friction connection between the surfaces and the resilient portion. This is advantageous for increasing the clamping force of the fastener relative to the applied tightening force.

[0019] According to another embodiment, the top engaging portion comprises a first inclined surface extending circumferentially around the axis, and wherein the first inclined surface faces away from the axis and towards the base portion, and wherein the base engaging portion comprises a second inclined surface extending circumferentially around the axis, wherein the second inclined surface faces away from the axis and towards the top portion. This provides for easy assembly of the composite gasket. The first inclined surface and the second inclined surface allow the resilient portion to slide to its intended position with minimal force, where it engages with the top engaging portion and the base engaging portion. The top engaging portion and the base engaging portion further ensure that the resilient portion remains in its intended position.

[0020] According to another embodiment, the top portion comprises a first contact portion and the base portion comprises a second contact portion, wherein the first contact portion is in direct contact with the second contact portion. This provides that the top portion and the base portion are in contact in the primary state and the secondary state of the composite gasket. Thereby, the top portion can constrain the base portion in at least one direction. This is advantageous in avoiding undesired displacement of the base portion relative to the top portion.

[0021] According to another embodiment, the first contact portion restricts lateral movement of the second contact portion in a plane perpendicular to the axis. This provides that the top portion will restrict movement of the base portion in a plane perpendicular to the axis. This is advantageous to ensure that the top portion and the base portion are displaced relative to each other only in the direction of the axis, thereby avoiding tilting loading or the like.

[0022] According to another embodiment, the first contact portion comprises a first locking element and the second contact portion comprises a second locking element, wherein the first locking element engages with the second locking element such that the connection between the first contact portion and the second contact portion is maintained.

[0023] This provides that the top portion, the resilient portion and the base portion can remain connected due to the first locking element and the second locking element. Further, the composite gasket can advantageously be assembled by compressing the top portion towards the base portion along the axis. The first contact portion and the second contact portion are preferably connected with a force high enough to maintain the connection of the composite gasket during the intended use of the composite gasket, but low enough to enable disassembly of the gasket when required.

[0024] According to another embodiment, at least one of the top portion and the base portion comprises a recessed portion in the inner surface in contact with the elastic portion. This provides an improved ability to apply glue to the top portion and the base portion. Recessed portions are advantageous because more glue can be applied between the top portion or the base portion and the elastic portion. Recessed portions are further advantageous because they provide an irregular surface, which can improve the ability of the glue to bind towards the top portion or the base portion.

[0025] According to another embodiment, at least one of the top part and the base part comprises an outer surface, which is perpendicular to the axis and faces away from the elastic part, wherein the outer surface comprises an outer recess. This provides an improved ability to withstand rotational movement, which is advantageous because the top part or the base part can be locked against the object against which the fastener is fastened via the outer recess. Thereby, the rotational movement of the composite washer relative to any of the above objects is hindered. This is advantageous for preventing the fastener from loosening.

[0026] According to another embodiment, the outer recesses extend radially relative to the axis. This provides that the outer recesses are angled in a direction transverse to the direction of rotation of the composite washer, which is beneficial in providing rotational resistance to the fastener or the object against which the fastener is fastened.

[0027] According to another embodiment, a system for anchoring a post of a fence to a building construction is provided, the system including a composite washer. The use of a composite washer as a load indicator for a fastener for a fence on a building construction is particularly advantageous because the consequences of an accidental loosening of a fastener are serious. The composite washer will indicate by visual inspection whether the tightening force applied is sufficient to securely fasten the fence. Composite washers that allow visual inspection are further advantageous for fences on building construction because the fasteners to which the composite washers are applied can be arranged in exposed locations. Therefore, the location may be difficult to reach or it may be dangerous to reach the location. Thus, by using a composite washer and a load indicator, the requirement to apply torque to the fastener for inspection is removed.

[0028] According to another embodiment, the system further comprises a clamp for clamping the structure with a clamping force, wherein the composite washer is arranged so that the composite washer is compressed by the clamping force. This provides that the composite washer can indicate the clamping force of the clamp. It is further advantageous to arrange the composite washer so that it is compressed by the clamping force, because the composite washer will always be compressed when the clamp clamps the structure. Therefore, the user will be sure that the composite washer is not forgotten and will automatically be reminded by the force indicating the composite washer that a sufficient amount of clamping force has been applied. In addition, due to the expansion effect of the composite washer when compressed, the clamp will automatically be prevented from loosening.

[0029] According to another embodiment, the system further comprises a wing nut arranged for compressing the composite washer and the clamp. By providing a wing nut, a user is able to apply a tensioning force on the wing nut, for example using a hammer, and thereby tension the system for anchoring a column. This is advantageous because, due to the composite washer, the user is able to apply a large amount of force while still ensuring that the applied force is within the desired tensioning range.

[0030] According to another embodiment, the composite washer is used as a safe load indicator. This provides a visual indicator of the composite washer that can be used to indicate that the load is within the range of the lifting device. This is beneficial for preventing the lifter from being overloaded (i.e. when the load is greater than the lifting capacity of the lifter).

[0031] According to another embodiment, a system for indicating a safe lifting force is provided, the system comprising a composite washer. According to another embodiment, the system for indicating a safe lifting force further comprises: a lower lifting pin, the lower lifting pin comprising a lower flat portion and a lifting portion; and an upper lifting pin, the upper lifting pin comprising an upper flat portion and a bearing portion, wherein the lifting portion is arranged to be lifted and the bearing portion is arranged to bear a load, wherein the washer is arranged between the lifting portion and the bearing portion, such that when the system is lifted and bears a load, the lower flat portion and the upper flat portion are arranged to compress the composite washer along the axis.

[0032] According to another embodiment, the lower flat portion comprises a lower aperture and the upper flat portion comprises an upper aperture, and wherein the carrier portion and the lifting portion are arranged to extend through the lower aperture and the upper aperture, respectively. This provides a system that can be used in conjunction with a lifting device to indicate a safe lifting force. By providing apertures in the upper and lower lifting pins, the lateral surface of the composite washer can be fully visible to the user. This is advantageous for enabling the user to see the load indication given by the composite washer as clearly as possible. The components of the composite washer are preferably adapted so that the load is less than the capacity of the lifting device as long as the composite washer has not reached its secondary state.

[0033] It should also be noted that, unless explicitly stated otherwise, the inventive concept relates to all possible combinations of features. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present disclosure is described in the following illustrative and non-limiting detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0035] Figure 1 is a visualization of a composite gasket according to an embodiment of the present disclosure.

[0036] Figure 2a and Figure 2b yes Figure 1 Visualization of a composite gasket in its primary state and in its secondary state.

[0037] Figure 3 is a cross-sectional view of a composite gasket according to an embodiment of the present disclosure.

[0038] Figures 4 to 10 Additional embodiments of the present disclosure are shown.

[0039] Fig.11 A system for anchoring a fence post to a building structure is shown, the system including a composite washer.

[0040] Figure 12 to Figure 13 Another embodiment of a system for anchoring a fence post to a building structure is shown, the system including a composite washer and a clamp.

[0041] Fig.14 is a visualization of the system used to indicate safe lifting force.

[0042] Fig.15 is an exploded view of the components included in the system for indicating safe lifting force.

[0043] All the figures are schematic, not necessarily drawn to scale, and generally show only the parts necessary for the elucidation of the present disclosure, wherein other parts may be omitted or merely suggested. Throughout the figures, the same reference numerals refer to the same, or substantially the same, features. DETAILED DESCRIPTION

[0044] For simplicity, construction details have been omitted in the following description, which may be considered as basic knowledge to a skilled person and do not contribute to describing the essence of the inventive concept.

[0045] Reference now Figure 1 , Figure 2a , Figure 2b and Figure 3 A first illustrative embodiment of a composite gasket 100 is described. Figure 1A composite washer 100 is shown that includes a top portion 120, a resilient portion 130, and a base portion 140. The top portion 120 has a circumferential extension around an axis A. The resilient portion 130 has a circumferential extension around an axis A. The base portion 140 has a circumferential extension around an axis A. The top portion 120, the resilient portion 130, and the base portion 140 are connected to each other, wherein the resilient portion 130 is arranged between the top portion 120 and the base portion 140, so that there is a central opening 102 that passes through the top portion 120, the resilient portion 130, and the base portion 140 along the axis A. The central opening 102 has a diameter that is large enough to allow a portion of a desired component, such as a shank of a fastener, to extend through the central opening 102. In the disclosed embodiment, the top portion 120 includes an outer top wall portion 121 and an inner top wall portion 128 that extend circumferentially around the axis A. The outer top wall portion 121 and the inner top wall portion 128 have a longitudinal extension parallel to the axis A, toward the base portion 140. The outer top wall portion 121 is further arranged at the outer circumference of the top portion 120, and the inner top wall portion 128 is arranged at the inner circumference of the top portion 120. The base portion 140 includes an outer base wall portion 141 and an inner base wall portion 148 extending circumferentially around the axis A. The outer base wall portion 141 and the inner base wall portion 148 have a longitudinal extension parallel to the axis A, toward the top portion 120. The outer base wall portion 141 is arranged at the outer circumference of the base portion 140, and the inner base wall portion 148 is arranged at the inner circumference of the base portion 140. The top portion 120 and the base portion 140 are preferably made of metal (such as steel or aluminum). However, it is conceivable that the top portion 120 or the base portion 140 can be made of any hard and durable material. The elastic part 130 is made of an elastic material, and preferably of polyurethane. It is also conceivable that the elastic part 130 is made of, for example, EPDM rubber. Figure 1 The composite gasket 100 in FIG. 1 is shown in a primary state S1. In the embodiment shown, the elastic portion 130 is glued to the top portion 120 and the base portion 140. When the composite gasket 100 is in its primary state S1, the top portion 120 is not in direct contact with the base portion 140. Therefore, the elastic portion 130 is visible at the lateral surface 104 of the composite gasket 100. The elastic portion 130 is preferably colored with a visually different color, such as red or green. Alternatively, the elastic portion 130 can be fluorescent. Figure 2a and Figure 2bThe primary state S1 and the secondary state S2 of the composite gasket 100 are shown, respectively. The composite gasket 100 is arranged to be in its primary state S1 when uncompressed. In the primary state S1, the top portion 120 and the base portion 140 are separated by the elastic portion 130. Therefore, the elastic portion 130 is visible at the lateral surface of the composite gasket 100. The composite gasket 100 is arranged to be compressed along the axis A so that the composite gasket 100 is compressed to its secondary state S2. When the composite gasket 100 is in its secondary state S2, the elastic portion 130 is hidden by the top portion 120 and the base portion 140 at its lateral surface 104. In the present embodiment, the composite gasket 100 is further configured so that the outer top wall portion 121 and the outer base wall portion 141 are separated in the primary state S1 and are in contact in the secondary state S2. As in Figure 1 As seen in FIG. 1 , the inner top wall portion 128 and the inner base wall portion 148 are similarly arranged such that they are separated in the primary state S1 and are in contact in the secondary state S2 . Figure 3 Shown from Figure 1 AA of the composite gasket 100 in its primary state S1. The elastic portion 130 has a longitudinal extension in a direction parallel to the axis A. In the embodiment shown, the elastic portion 130 has a rectangular cross section. The elastic portion 130 is in direct contact with the top portion 120 and the base portion 140.

[0046] Reference now Figures 4 to 10 A total of seven additional exemplary embodiments of composite washers 200, 300, 400, 500, 600, 700, and 800 are described. All seven exemplary embodiments have similarities to those of reference 1. Figure 1 , Figure 2a , Figure 2b and Figure 3 The first exemplary embodiment of the composite gasket 100 described is of substantially similar construction. The nomenclature of the details is similar for all seven additional embodiments, except for the first digit of the reference numerals which refers to the respective exemplary embodiment of the composite gasket.

[0047] Reference now Figure 4 A second illustrative embodiment of a composite gasket 200 is described. Figure 4 A cross section of a composite gasket 200 is shown, wherein the gasket is in its primary state S1. The elastic portion 230 has a longitudinal extension in the direction of the axis A from an upper portion 231 via a middle portion 232 to a lower portion 233. The elastic portion 230 has a first inner diameter D1 at the upper portion 231, which is smaller than a second inner diameter D2 at the middle portion 232, wherein a third inner diameter D3 is smaller than the second inner diameter D2. Therefore, the elastic portion 230 is provided with a concave inner surface.

[0048] Reference now Figure 5 A third illustrative embodiment of a composite gasket 300 is described. Figure 5 The composite gasket 300 is shown in its primary state S1. In the embodiment shown, the resilient portion 330 comprises a groove 334 having a circumferential extension around the inner surface of the resilient portion 330 facing the axis A. The groove 334 has a concave shape which, in the embodiment shown, is positioned on the resilient portion between the inner top wall portion 328 and the inner base wall portion 348.

[0049] Reference now Figure 6 A fourth illustrative embodiment of a composite gasket 400 is described. Figure 6 A composite gasket 400 is shown, wherein the gasket is in its primary state S1. In the illustrated embodiment, the top portion 420 includes a top engaging portion 422. The top engaging portion 422 engages with the elastic portion 430 so that the connection between the elastic portion 430 and the top portion 420 is maintained. More particularly, the top engaging portion 422 radially protrudes from the inner top wall portion 428 in a direction away from the axis A at the end of the inner top wall portion 428 closest to the base portion 440. In other words, the top engaging portion 422 constitutes a lip extending radially outward from the inner top wall portion 428. The top engaging portion 422 has a circumferential extension around the axis A. The top engaging portion 422 protrudes away from the axis A by a distance that is long enough to engage with the elastic portion 430 to maintain the connection between the top portion 420 and the elastic portion 430. Further, the base portion 440 includes a base engaging portion 442. The base engaging portion 442 engages with the elastic portion 430 so that the connection between the elastic portion 430 and the base portion 440 is maintained. More specifically, the base engaging portion 442 radially protrudes from the inner base wall portion 448 in a direction away from the axis A at the end of the inner base wall portion 448 closest to the top portion 420. In other words, the base engaging portion 442 constitutes a lip extending radially outward from the inner base wall portion 448. The base engaging portion 442 has a circumferential extension around the axis A. The base engaging portion 442 protrudes away from the axis A by a certain distance that is long enough to enable it to engage with the elastic portion 430 to maintain the connection between the base portion 440 and the elastic portion 430. In the present embodiment, the elastic portion 430 has a C-shaped radial cross-section. This is to improve the ability of the top engaging portion 422 and the base engaging portion 442 to engage with the elastic portion 430. As Figure 6As shown, the top engaging portion 422 engages with the upper portion of the C-shaped cross-section of the resilient portion 430, and the base engaging portion 442 engages with the lower portion of the C-shaped cross-section of the resilient portion 430. The interconnection of the top portion 420, the resilient portion 430, and the base portion 440 is preferably high enough to maintain the interconnection when the composite gasket 400 is used according to the intended use of the composite gasket 400, and is preferably low enough to enable the user to disassemble the composite gasket 400 when necessary. In the present embodiment, the top engaging portion 422 includes a first inclined surface 423 that extends circumferentially around the axis A and away from the axis A and toward the base portion 440. Further, the base engaging portion 442 includes a second inclined surface 423 that extends circumferentially around the axis A and away from the axis A and toward the top portion 420.

[0050] Reference now Figure 7 A fifth illustrative embodiment of a composite gasket 500 is described. Figure 7 The composite gasket 500 is shown, wherein the gasket is in its primary state S1. In the illustrated embodiment, the top portion 520 includes a first contact portion 525, and the base portion 540 includes a second contact portion 545. The first contact portion 525 is in direct contact with the second contact portion 545 in the primary state S1 of the composite gasket 500 and in the secondary state S2 of the composite gasket. In the illustrated embodiment, the first contact portion 525 has a circumferential extension around the axis A and a longitudinal extension parallel to the axis A, toward the base portion 540. The second contact portion 545 has a circumferential extension around the axis A and the first contact portion 525 and a longitudinal extension parallel to the axis A, toward the top portion 520, wherein a portion of the first contact portion 525 and a portion of the second contact portion 545 extend in parallel. The first contact portion 525 and the second contact portion 545 engage with each other so that they restrict relative movement to each other in a plane perpendicular to the axis A. In other words, the first contact portion 525 and the second contact portion 545 are generally arranged concentrically with each other. In the illustrated embodiment, the elastic portion 530 has a fourth inner diameter D4 at an upper portion 531 of the elastic portion 530 , which is greater than a fifth inner diameter D5 at a middle portion 532 of the elastic portion 530 .

[0051] Reference now Figure 8 A sixth illustrative embodiment of a composite gasket 600 is described. Figure 8 The composite gasket 600 is shown in which the gasket is in its primary state S1. Figure 7In contrast to the composite washer shown, the first contact portion 625 has a circumferential extension around the second contact portion 645. The first contact portion 625 includes a first locking element 624 extending circumferentially around the axis A. In the embodiment shown, the first locking element 624 includes a circumferential surface having a sixth inner diameter D6, which is slightly smaller than the seventh inner diameter D7 of the remainder of the first contact portion 625. The second contact portion 645 includes a second locking element 644. The second locking element 644 extends circumferentially around the axis A and is arranged to have an outer diameter greater than the sixth inner diameter D6 of the first locking element 624. The first locking element 624 is arranged to engage with the second locking element 644 when the composite washer 600 is in its primary state S1, so that the connection between the first contact portion 625 and the second contact portion 645 is maintained. Thereby, the second locking element 644 restricts the base portion 640 from moving away from the top portion 620 by abutting toward the first locking element 624.

[0052] Reference now Fig. 9 A seventh illustrative embodiment of a composite gasket 700 is described. Fig. 9 A composite gasket 700 according to another embodiment is shown. The top portion 720 includes an inner recess (not shown) located on the inner surface of the top portion 720, which is perpendicular to the axis A and in contact with the elastic portion 730. The base portion 740 includes an inner recess (not shown) located on the inner surface of the base portion 740, which is perpendicular to the axis A and in contact with the elastic portion 730. The inner recesses of the top portion and the inner recesses of the base portion 740 extend radially relative to the axis A and are evenly distributed. In the embodiment shown, the top portion 720 further includes an outer surface, which is perpendicular to the axis A and faces away from the elastic portion 730, wherein the outer surface includes an outer recess 727. The outer recess 727 extends radially relative to the axis A. The base portion 740 further includes an outer surface, which is perpendicular to the axis A and faces away from the elastic portion 730, and includes similar outer recesses (not shown) that extend radially relative to the axis A.

[0053] Reference now Fig.10 An eighth illustrative embodiment of a composite gasket 800 is described. Fig.10 The composite gasket 800 is shown in its primary state S1. The composite gasket 800 includes a top portion 820, a resilient portion 830, and a base portion 840. The top portion 820 includes an inner top wall portion 828 and a top engaging portion 822. The inner top wall portion 828 and the top engaging portion 822 have the same Figure 6The inner top wall portion 428 and the top engaging portion 422 shown in the fourth exemplary embodiment shown have similar functions. The top engaging portion 822 engages with the elastic portion 830 so that the connection between the elastic portion 830 and the top portion 820 is maintained. More specifically, the top engaging portion 822 radially protrudes from the inner top wall portion in a direction away from the axis A at the end of the inner top wall portion 828 closest to the base portion 840. The base portion 840 includes an inner base wall portion 848 and a base engaging portion 842. The inner base wall portion 848 and the base engaging portion 842 have similar Figure 6 The inner base wall portion 448 and the base engaging portion 442 shown in the fourth illustrated embodiment are similar in function. The base engaging portion 842 engages with the resilient portion 830 so that the connection between the resilient portion 830 and the base portion 840 is maintained. More specifically, the base engaging portion 842 radially protrudes from the inner base wall portion in a direction away from the axis A at the end of the inner base wall portion 848 closest to the top portion 820. In this embodiment, the top engaging portion 822 includes a first inclined surface 823 that extends circumferentially around the axis A and away from the axis A and toward the base portion 840. The base engaging portion 842 includes a second inclined surface 843 that extends circumferentially around the axis A and away from the axis A and toward the top portion 820. The top engaging portion 822 includes a third inclined surface 829 that extends circumferentially around the axis A and away from the axis A and away from the base portion 840. The base engaging portion 842 includes a fourth inclined surface 849 extending circumferentially about the axis A and facing away from the axis A and away from the top portion 820. The third and fourth inclined surfaces engage the resilient portion 830 and thus have corresponding inclined surface portions.

[0054] Reference now Figures 11 to 13 A total of two exemplary embodiments of systems 900, 1000 for anchoring fence posts to building structures are described.

[0055] Reference now Fig.11 A first exemplary embodiment of a system 900 for anchoring a fence post to a building structure is described. Fig.11A system 900 for anchoring a post of a fence to a building structure is shown, the system including a composite washer 100. The system 900 includes an anchoring structure 903 and a fastener 904, which is arranged to fasten the anchoring structure 903 to the building structure B. In the embodiment shown, the fastener 904 is a concrete bolt. The composite washer 100 is arranged between the fastener 904 and the anchoring structure 903, so that when the anchoring structure 903 is fixed to the building structure B by the fastener 904, the composite washer is compressed. The shank of the fastener 904 extends through the central opening 102 of the composite washer 100. The composite washer 100 is further arranged to be compressed to its secondary state S2 when the required tensioning force has been applied to the fastener 904. It is contemplated that the fastener may be a fastener of other types other than a bolt, such as a screw or a nut.

[0056] Reference now Fig.12 and Fig.13 A second exemplary embodiment of a system 1000 for anchoring a fence post to a building structure is described. Fig.12 and Fig.13 A system 1000 for anchoring a post of a fence to a building structure is shown according to another embodiment. The system 1000 includes a clamp 1001 for clamping a structure of a building structure with a clamping force and a composite washer 100. The composite washer 100 is arranged so that it is compressed by the clamping force. The system 1000 for anchoring a post of a fence further includes a wing nut 1002, which is arranged to compress the composite washer 100 while tensioning the clamp 1001. The clamp 1001 may further include a threaded rod 1005, a fixed clamping member 1006 attached to one end of the threaded rod 1005, and a movable clamping member 1007, which is arranged at the threaded rod 1003 so that the movable clamping member can move along the threaded rod 1005. The wing nut 1002 is threadedly engaged with the threaded rod 1005. Composite washer 100 is compressed when the user places the clamp at the structure, contacts clamping members 1006, 1007 with opposite sides of the structure (such as a floor), and tightens wing nut 1002. Sufficient clamping force has been achieved when the elastic portion is no longer visible between the top and base portions of composite washer 100.

[0057] Figure 14 to Figure 15 A system 1100 for indicating a safe lifting force is shown, the system comprising the composite washer 100. The system 1100 for indicating a safe lifting force comprises a lower lifting pin 1110 and an upper lifting pin 1120. Fig.14100. An exploded view of the system 1100 is shown in FIG. The lower lifting pin 1110 includes a lower flat portion 1111 formed as a circular plate, and a lifting portion 1112 connected to the lower flat portion at the center of the lower flat portion 1111 so that the lifting portion 1112 protrudes in a direction perpendicular to the flat surface of the lower flat portion 1111. The lifting portion 1112 includes an opening at an end thereof, which is the end farthest away from the lower flat portion 1111. Further, the lower flat portion 1111 includes two lower orifices 1113, one on each side of the lifting portion 1112 and equidistant from the center of the lower flat portion 1111. The system for indicating the safe lifting force 6 further includes an upper lifting pin 1120. The upper lifting pin 1120 includes an upper flat portion 1121 formed as a circular plate, and a bearing portion 1122. The bearing part includes two arms connected to the upper flat part 1121 and protruding from the circular plate surface of the upper flat part 1121 in the vertical direction. Each of the two arms of the bearing part 1122 includes an opening for attaching a load at its end farthest from the upper flat part 1121. The upper flat part 1121 includes an upper orifice 1123 at its center. The system 1100 for indicating a safe lifting force is assembled so that the composite washer 100 is mounted on the lower lifting pin 1110 so that the lifting part 1112 extends through the opening of the composite washer 100. The upper lifting pin 1120 is installed together with the lower lifting pin 1110 and the composite washer 100 so that the lifting part 1112 extends through the upper orifice 1123 of the upper lifting pin 1120, and so that the two arms of the bearing part 1122 extend through the opening of the composite washer 100 and the two orifices 1113 of the lower lifting pin. The load is attached to the upper lifting pin 1120. Thereafter, the system 1100 for indicating a safe lifting force can be lifted by the lifting device in the opening of the lower lifting pin 1110 and carries the load attached to the two openings of the upper lifting pin 1120. When the system 1100 for indicating a safe lifting force is lifted, the lower flat portion 1111 and the upper flat portion 1121 will compress the composite gasket 100 with a force equal to the lifting force. The composite gasket 100 is preferably modified such as not to be fully compressed so that as long as the lifting force is within the safe load of the lifting device, the composite gasket reaches the secondary state S2. Therefore, the user using the system will have a visual indicator showing whether the lifting force is within the safety limit of the lifting device. The elastic portion 130 of the composite gasket 100 is preferably colored with a visually different color, such as green.

[0058] While the present disclosure has been shown and described in detail in the drawings and foregoing description, such showing and description are to be considered illustrative or exemplary and not restrictive. The present disclosure is not limited to the disclosed embodiments.

[0059] Other variations of the disclosed embodiments may be understood and effected by those skilled in the art in practicing the claimed disclosure, from a study of the drawings, the present disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A composite washer for force indication and preventing fastener loosening, the composite washer comprising: a top portion having a circumferential extension around the axis, an elastic portion having a circumferential extension around the axis, a base portion having a circumferential extension around the axis, wherein the top portion, the elastic portion and the base portion are connected to each other, wherein the elastic portion is arranged between the top portion and the base portion, wherein there is a central opening having an extension along the axis through the top portion, the elastic portion and the base portion, wherein the composite gasket is arranged in a primary state in which the elastic portion is visible at a lateral surface of the composite gasket, and Wherein, the composite gasket is arranged in a secondary state, in which the elastic portion is compressed by the top portion and the base portion so that the elastic portion is hidden by at least one of the top portion and the base portion at the lateral surface of the composite gasket.

2. The composite gasket according to claim 1, wherein: The elastic portion has a longitudinal extension along the axis from an upper portion of the elastic portion via a middle portion to a lower portion, wherein a first inner diameter at the upper portion is different from a second inner diameter at the middle portion when the elastic portion is uncompressed.

3. The composite gasket according to claim 2, wherein: The first inner diameter is smaller than the second inner diameter.

4. A composite gasket according to any preceding claim, wherein: The resilient portion includes a groove extending circumferentially around an inner surface of the resilient portion facing the axis.

5. A composite gasket according to any preceding claim, wherein: The elastic portion is in direct contact with the top portion and the base portion.

6. A composite gasket according to any preceding claim, wherein: The elastic part is made of the material polyurethane.

7. A composite gasket according to any preceding claim, wherein: The elastic portion has a visually distinct color, such as red or green.

8. A composite gasket according to any preceding claim, wherein: The elastic portion is fluorescent.

9. A composite gasket according to any preceding claim, wherein: The elastic portion is glued to the top portion and the base portion.

10. A composite gasket according to any preceding claim, wherein: The top portion includes an outer top wall portion, which extends circumferentially around the axis, wherein the outer top wall portion has a longitudinal extension toward the base portion, wherein the base portion includes an outer base wall portion, which extends circumferentially around the axis, and wherein the outer base wall portion has a longitudinal extension toward the top portion.

11. The composite gasket according to claim 10, wherein: The outer top wall portion and the outer base wall portion are arranged to be separated in the primary state and to be in contact in the secondary state.

12. The composite gasket according to claim 11, wherein: The outer top wall portion is arranged at an outer circumference of the top portion, and wherein the outer base wall portion is arranged at an outer circumference of the base portion.

13. A composite gasket according to any preceding claim, wherein: The top portion includes a top joining portion, which is joined to the elastic portion so that the connection between the elastic portion and the top portion is maintained, and wherein the base portion includes a base joining portion, which is joined to the elastic portion so that the connection between the elastic portion and the base portion is maintained.

14. The composite gasket according to claim 13, wherein: The top engaging portion includes a first inclined surface extending circumferentially around the axis, and wherein the first inclined surface faces away from the axis and toward the base portion, and wherein the base engaging portion includes a second inclined surface extending circumferentially around the axis, and wherein the second inclined surface faces away from the axis and toward the top portion.

15. A composite gasket according to any preceding claim, wherein: The top portion includes a first contact portion and the base portion includes a second contact portion, wherein the first contact portion is in direct contact with the second contact portion.

16. The composite gasket according to claim 15, wherein: The first contact portion restricts lateral movement of the second contact portion in a plane perpendicular to the axis.

17. The composite gasket according to claim 15, 15 or 16, wherein: The first contact portion includes a first locking element and the second contact portion includes a second locking element, wherein the first locking element engages with the second locking element such that a connection between the first contact portion and the second contact portion is maintained.

18. A composite gasket according to any preceding claim, wherein: At least one of the top portion and the base portion includes an inner recess in an inner surface that contacts the elastic portion.

19. A composite gasket according to any preceding claim, wherein: At least one of the top portion and the base portion includes an outer surface that is perpendicular to the axis and faces away from the resilient portion, wherein the outer surface includes an outer recess.

20. The composite gasket according to claim 19, wherein: The outer recesses extend radially relative to the axis.

21. A system for anchoring a fence post to a building structure, the system comprising a composite washer according to any preceding claim.

22. A system for anchoring a fence post to a building structure as claimed in claim 21, wherein: The system further includes a clamp for clamping the structure with a clamping force, wherein the composite washer is arranged such that the composite washer is compressed by the clamping force.

23. A system for anchoring a fence post to a building structure as claimed in claim 21 or 2222, the system further comprising a wing nut arranged to compress the composite washer and the clamp.

24. The composite gasket according to any one of claims 1 to 19, wherein: The composite washer is used as a safe lifting force indicator.

25. A system for indicating a safe lifting force, the system comprising a composite washer according to any one of claims 1 to 19.

26. The system for indicating a safe lifting force according to claim 25, further comprising: a lower lift pin comprising a lower flat portion and a lift portion; as well as an upper lifting pin comprising an upper flat portion and a carrier portion, wherein the lifting portion is arranged to be lifted and the carrier portion is arranged to carry a load, Therein, the gasket is arranged between the lifting portion and the load bearing member portion, such that when the system is lifted and carries a load, the lower flat portion and the upper flat portion are arranged to compress the composite gasket along the axis.

27. A system for indicating safe lifting force, wherein: The lower planar portion comprises a lower aperture and the upper planar portion comprises an upper aperture, and wherein the carrier portion and the lifting portion are arranged to extend through the lower aperture and the upper aperture, respectively.

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