TECHNICAL FIELD

This invention relates to fasteners. More specifically, this invention relates to a safety clasp for mechanical fasteners and to a method of applying a safety clasp to a mechanical fastener.

BACKGROUND ART

[0001] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0002] When working at heights with mechanical tools, workers often do not have sufficient storage or hands available to them when having to make adjustments or repairs to apparatus that needs to be serviced, repaired, replaced, or manipulated. When working with large mechanical fasteners, for example, there have been instances in the past of components of such fasteners falling from a height and injuring workers below, especially when loosening fasteners associated with load-engaging apparatus, such as multi- tonnage shackles.

[0003] It is an object of this invention to address certain of the shortcomings of existing mechanical fastener systems of which the Applicant is aware, and/or to at least provide the public with a useful choice.

SUMMARY OF THE INVENTION

[0004] According to one aspect of the invention there is provided a safety clasp for securely engaging a mechanical fastener. The safety clasp includes: a body defining a seat for receiving a mechanical fastener, the mechanical fastener being securable to a complementary fastening member; at least two primary engagement formations/members extending from the seat for engaging the mechanical fastener; and a tether-engaging component for tethering the safety clasp to an anchor point external to, and separate from, the mechanical fastener. The tether-engaging component is rotatable relative to the body.

[0005] In one embodiment, the safety clasp comprises a tether attached to the tether-engaging component.

[0006] The mechanical fastener may be a bolt, a threaded shaft, a shackle pin, or a nut, the mechanical fastener having faceted surfaces provided thereon.

[0007] The, or each, faceted surface may be in the form of a multifaceted formation/member provided on the bolt, shaft, pin, or nut, most typically in the form of a hex-nut having six facets. [0008] The primary engagement formations/members typically each engage a respective faceted surface of the mechanical fastener. In an embodiment the primary engagement formations/members include two opposing primary engagement formations that engage opposing faceted surfaces of the mechanical fastener. [0009] When the mechanical fastener is in the form of a hex- nut having six faceted surfaces, the primary engagement formations/members of the safety clasp may be configured to engage with two or more respective faceted surfaces of the hex-nut.

[0010] The number of primary engagement formations/members may be commensurate with the number of faceted surfaces or gripping surfaces of the mechanical fastener to be gripped. For a hex nut, therefore, the seat may include six primary engagement formations/members .

[0011] When in the form of a threaded shaft or spindle or shackle pin having a hexagonal gripping surface provided at one end thereof, the primary engagement formations/members may engage with two or more of the respective facets of the hexagonal gripping surface .

[0012] The primary engagement formations/members may each be shaped and dimensioned to snugly receive a desired size of gripping surface, and/or together with the seat may define a cavity to receive the mechanical fastener.

[0013] In one embodiment, the primary engagement formations/members comprise six tabs extending from a periphery of the seat to define a hexagonal cavity to receive the mechanical fastener, wherein the mechanical fastener is a hex nut or hex bolt head .

[0014] As such, the primary engagement formations/members may engage with the gripping surface in a light interference fit or press fit manner, in one embodiment. In another embodiment, the engagement formations/members may extend past an edge of the gripping surface, thereby to allow each of the primary engagement formations/members to be receivable at least partially around, or over, the faceted surfaces, thereby to securely fasten the safety clasp to the mechanical fastener.

[0015] One or more of the primary engagement formations/members may be provided with a secondary engagement member, typically in the form of fasteners that serve to clamp or bolt the safety clasp to the mechanical fastener. [0016] At least one of the primary engagement formations/members may be provided with a secondary engagement member to increase the purchase of the body on the fastener.

[0017] In certain embodiments, each of the primary engagement formations/members may be provided with a secondary engagement member. [0018] In one embodiment, the or each secondary engagement member comprises a grub screw, which is received through a threaded aperture in the respective primary engagement formation/member. The grub screws may be adjustable to protrude inwardly from the primary engagement formations/members to grip the mechanical fastener .

[0019] Once attached, each secondary fastener may be provided with a restraining formation/member to prevent loosening (such as by rotational movement) of the secondary fastener, or to serve as an indicator of movement of the secondary fastener relative to the engagement formation/member, or relative to other secondary fasteners .

[0020] Typically, the restraining formations/members may be in the form of a thin-section wire that passes through, or is tightly associated with, the secondary engagement members, thereby to prevent accidental or incidental loosening of the secondary engagement members in operation. The ends or the wire may be twisted or otherwise secured together. The secondary engagement members may each comprise a transverse aperture to receive the restraining wire.

[0021] As such, each primary engagement formation/member may be provided with a secondary engagement member in the form of a grub screw received through, and rotatably adjustable within, a threaded aperture defined within one or more of the primary engagement formations/members, thereby to engage with each the faceted surfaces of the mechanical fastener.

[0022] To further aid secure location of the engagement formations/members, each facet or face of the gripping surface may be provided with an indent or aperture for receiving the secondary engagement formation/member. [ 0023 ] When applied to a nut, a tertiary engagement formation/member may be provided, proximal the nut, typically in the form of a split pin which passes through the body of a bolt or shackle pin to which the nut is affixed. The tertiary engagement formation/member may be directly or indirectly tethered to the body. In one embodiment a split pin is connected to the tether by a secondary tether. The tether-engaging component may comprise an annular portion or be connected to a component having an annular portion, the annular portion being rotatably mounted on the body to enable relative rotation between the tether-engaging component and the body. In one embodiment the tether-engaging component has an arm that extends from the annular portion, with the tether attached to the arm near the distal end of the arm.

[ 0024 ] The body may comprise a neck or groove to receive the annular portion, with a flange or lip at an end of the neck or groove to restrain the annular portion relative to the body. In some embodiments, the neck or groove may provide a bearing surface for the annular portion to bear against the body as it is rotated.

[ 0025 ] As such, when the tether is attached to the anchor point (e.g. such as a body of a shackle) the tether may be attached to a fixed formation such that the tether prevents the safety clasp (and thus also the mechanical fastener being held thereby) from falling, should the mechanical fastener separate from the complementary fastening member to which it would have been attached.

[ 0026 ] When in the form of a shackle, the mechanical fastener to be secured by the safety clasp of the invention would be in the form of an end hex nut that is fitted to a shackle pin that extends through a shackle body to which the tether is to be attached. [ 0027 ] Of course, the safety clasp of the invention may also be used to secure an end of the shackle pin, should the shackle pin ever separate from the body of the shackle while at height. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 shows a three-dimensional exploded view of an embodiment of a safety clasp in accordance with one aspect of the invention;

Figure 2 shows a three-dimensional assembled view of a safety clasp of Figure 1, attached to a nut of a shackle pin;

Figure 3 shows a cross-sectional side view of a safety clasp in of Figure 2, when attached to a fastener.

DETAILED DESCRIPTION OF EMBODIMENTS

[0029] The following embodiments, given by way of example only, are described in order to provide a more precise understanding of the subject matter of a preferred embodiment or embodiments. [0030] In the figures, incorporated to illustrate features of a non-limiting example embodiment, like reference numerals are used to identify like parts throughout the figures.

[0031] With reference to the Figures, reference numeral 10 is used throughout this specification to indicate, generally, a safety clasp of the invention.

[0032] Figure 1 shows an exploded view of one embodiment of a safety clasp 10 of the invention, comprising a body 12 for securely engaging a mechanical fastener 14. The body 12 is shaped and dimensioned to define a cavity with a seat 12.1 for snugly receiving or cradling the fastener 14. The fastener 14, as shown in Figure 1, is typically a hex-nut that is used to secure a shackle pin 16 of a shackle 18. Such shackles frequently need to be opened or adjusted at height by a worker in a sling using manual tools, which can result in the fastener 14 dropping from great height, causing potential injuries or damage below. The shackle pin 16 typically includes a threaded section 16.1 that engages with a complementarily threaded interior surface 14.1 of the hex- nut 14. The body 12 defines a through hole to receive the shackle pin 16 through the body when it is secured to the nut 14.

[0033] The shackle pin is usually additionally secured using a tertiary engagement member typically in the form of a pin such as a split pin 17 to prevent the shackle pin loosening from the nut 14. The split pin 17 is first removed from the shackle pin when a worker needs to remove the fastener 14 from the shackle pin, and in turn remove the shackle pin 16 from the shackle to release a load (not shown) .

[0034] Referring to Figure 1, the safety clasp 10 of the invention further includes six primary engagement formations/members in the form of tabs 20 extending upwardly from the body 12 at a periphery of the seat 12.1. The tabs 20 are shaped and dimensioned to be approximately the same size and shape as the facets 14.2 of the hex nut 14. As such, the tabs 20 line up with, and slide across, the facets 14.2 of the hex nut 14 when the safety clasp 10 is placed over the hex nut 14 prior to the nut 14 being secured to the shackle pin 16. The tabs 20 and seat 12.1 together define a cavity to receive the nut.

[0035] In certain embodiments (not shown) , provision is only made for two diametrically opposed tabs 20 that engage with two diametrically opposed facets 14.2 of the hex nut 14, while in other embodiments use can be made of three, four, or five radially spaced tabs 20. Of course, it falls within the scope of the invention to have the actual arrangement of the tabs 20 be in concordance with the desired application and fastener type to which the safety clasp 10 is to be applied.

[0036] While it is within the scope of the invention to have the tabs 20 of the safety clasp 10 positioned such that they securely hold the nut 14 by way of a friction fit, press fit, or a light interference fit, in the embodiment shown, secondary engagement members in the form of one of more grub screws 22 (of which only one is shown in Figure 1 for purposes of clarity) pare provided in apertures 20.1 defined through each of the tabs 20. Of course, not each tab 20 requires a grub screw 22, but certain embodiments in certain safety applications will require each tab 20 to have a grub screw 22 threadedly secured therein to bite into and interact with each facet 14.2 of the hex nut 14. The grub screws can be adjusted to protrude inwards from the tabs, to grip or otherwise engage the hex nut 14.

[0037] The safety clasp 10 has a tether-engaging component 24 for operably engaging a tether 26. In the embodiment shown, the tether engaging component is a single member in the form of arm 24. An aperture 24.1 at an end of the arm 24 distal to the main body 12 serves as attachment point for a first end 26.1 of tether 26. The tether 26 in turn is attached to the body of the shackle 18, by way of second end 26.2 (best seen in Figure 2) .

[0038] In this way, one can securely tether the safety clasp 10 and associated fastener/nut 14 to prevent the fastener/nut 14 from falling when loosened from the shackle pin 16. The tether may comprise a wire, cable, chain, or other flexible member capable of supporting the weight of the safety clasp body 12 and associated fastener 14. The split pin 17 may also be directly or indirectly tethered to the safety clasp and/or to the shackle 18 to prevent the pin being dropped inadvertently.

[0039] To further aid secure location of the primary engagement formations/members (i.e. tabs 20), each facet 14.2 of the nut 14 may optionally be provided with an indent or aperture 14.3, best shown in Figures 1 and 3, for receiving part of the secondary engagement members, i.e. an end of the grub screws 22. In this way, more secure engagement is provided to secure the safety clasp 10 to the fastener 14.

[ 0040 ] As shown in Figures 2 and 3, usefully, the tether- engaging component 24 is rotatably mounted to the body 12 (and thus seat 12.1), such that the seat 12.1 and associated nut 14 can rotate relative to the tether-engaging component 24. In this way, the nut 14 and associated seat 12.1 can be loosened or fastened while the safety clasp 10 is in situ. That is, the clasp body 12 and nut 14 can be rotated for loosening or fastening while the safety clasp 10 is tethered to a shackle or other stationary tether point, without the tether wrapping around the fastener. [ 0041 ] The clasp body 12 and thereby the nut 14 can preferably tightened or loosened by hand. Alternatively, the exterior surface of the clasp body 12 may be shaped to provide purchase for a tool such as a wrench.

[ 0042 ] The tether component 24 further comprises an annular portion 24.2 that encircles an annular neck portion 12.2 of the body 12. The arm 24 is held in place by way of a flange 12.3 at the end of the neck portion 12.2. The neck portion 12.2 and flange 12.3 are fixed to the portion of the body forming the seat 12.1. For example, the neck 12.2 and flange may be integrally formed and welded or otherwise fixed to the portion of the body forming the seat 12.1. Alternatively the neck portion 12.2 may be integrally formed with the seat 12.1 and the flange 12.3 welded or otherwise fixed to the neck portion, or the neck 12.2, flange 12.3 and rest of the body may be integrally formed. Together the neck portion and annulus 24.2 form a swivel assembly 12.4.

[ 0043 ] The grub screws 22, in one embodiment, each may be provided with a transverse aperture through which a restraining formation/member in the form of a thin section wire 28 can be passed. This ensure that, once the grub screws 22 are firmly secured, they can all be strung together using the wire 28 and the ends or the wire twisted together or suitably secured to each other or to the body to ensure that the grub screws 22 do not inadvertently loosen due to vibration or mechanical shocks imparted to the shackle 18 during operation.

[0044] Instead of a wire through the grub screws, other restraining means may be provided. For example, a cover or ring that extends over the ends of the grub screws and around external surface of the tabs. In one embodiment a resilient ring, for example a plastic, silicone, or rubber ring, may be provided with internal protrusions for engaging the hex apertures in the ends of the grub screws. The ring or cover may be resilient and stretchable over the tabs 20 for a tight grip. The external surface of the tabs may have a groove, recess, or locating feature to locate the wire, ring, cover, or other restraining means on the body 12.

[0045] While the safety clasp 10 is illustrated secured to a nut, it will be apparent that the safety clasp 10 of the invention also finds use in securing an end (typically in the form of hex head 16.1) of the shackle pin 16, thereby to also prevent the shackle pin 16 from falling from height during the loading and unloading of loads.

[0046] Advantageously, the safety clasp 10 can be fitted to commercially available fasteners and shackles, providing a more versatile and cost effective safety solution than custom manufacturing tethered fasteners.

[0047] The safety clasp 10 is intended to be fixed to the nut 14, pin head 16.2, or other fastener before installation, to prevent such assembly steps being performed at height or in difficult environments. When tethered to a shackle 181 or other component, the safety clasp 10 advantageously provides a useful safety measure, to prevent the fastener 14 attached to the safety clasp from being dropped from height during operation in load engaging applications.

[ 0048 ] Optional embodiments of the present invention may also be said to broadly consist in the parts, elements and features referred to or indicated herein, individually or collectively, in any or all combinations of two or more of the parts, elements or features, and wherein specific integers are mentioned herein which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[ 0049 ] It is to be appreciated that reference to "one example" or "an example" of the invention is not made in an exclusive sense. Accordingly, one example may exemplify certain aspects of the invention, whilst other aspects are exemplified in a different example. These examples are intended to assist the skilled person in performing the invention and are not intended to limit the overall scope of the invention in any way unless the context clearly indicates otherwise. [ 0050 ] It is to be understood that the terminology employed above is for the purpose of description and should not be regarded as limiting. The described embodiment is intended to be illustrative of the invention, without limiting the scope thereof. The invention is capable of being practised with various modifications and additions as will readily occur to those skilled in the art .

[ 0051 ] Various substantially and specifically practical and useful exemplary embodiments of the claimed subject matter are described herein, textually and/or graphically, including the best mode, if any, known to the inventors for carrying out the claimed subject matter. Variations (e.g. modifications and/or enhancements) of one or more embodiments described herein might become apparent to those of ordinary skill in the art upon reading this application.

[0052] The inventor (s) expects skilled artisans to employ such variations as appropriate, and the inventor (s) intends for the claimed subject matter to be practiced other than as specifically described herein. Accordingly, as permitted by law, the claimed subject matter includes and covers all equivalents of the claimed subject matter and all improvements to the claimed subject matter. Moreover, every combination of the above described elements, activities, and all possible variations thereof are encompassed by the claimed subject matter unless otherwise clearly indicated herein, clearly and specifically disclaimed, or otherwise clearly contradicted by context.

[0053] The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate one or more embodiments and does not pose a limitation on the scope of any claimed subject matter unless otherwise stated. No language in the specification should be construed as indicating any non-claimed subject matter as essential to the practice of the claimed subject matter.

[0054] The use of words that indicate orientation or direction of travel is not to be considered limiting. Thus, words such as "front", "back", "rear", "side", "up", down", "upper", "lower", "top", "bottom", "forwards", "backwards", "towards", "distal", "proximal", "in", "out" and synonyms, antonyms and derivatives thereof have been selected for convenience only, unless the context indicates otherwise. The inventor (s) envisage that various exemplary embodiments of the claimed subject matter can be supplied in any particular orientation and the claimed subject matter is intended to include such orientations.

[0055] The use of the terms "a", "an", "said", "the", and/or similar referents in the context of describing various embodiments (especially in the context of the claimed subject matter) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "including", "having", "including", "comprising", and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to") unless otherwise noted.

[0056] Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value and each separate sub ^¬ range defined by such separate values is incorporated into the specification as if it were individually recited herein. For example, if a range of 1 to 10 is described, that range includes all values there between, such as for example, 1.1, 2.5, 3.335, 5, 6.179, 8.9999, etc., and includes all sub-ranges there between, such as for example, 1 to 3.65, 2.8 to 8.14, 1.93 to 9, etc.

[0057] Accordingly, every portion (e.g., title, field, background, summary, description, abstract, drawing figure, etc.) of this application, other than the claims themselves, is to be regarded as illustrative in nature, and not as restrictive; and the scope of subject matter protected by any patent that issues based on this application is defined only by the claims of that patent.