FASTENER INCLUDING REMOVABLE HEAD AND TAMPER-RESIST PART

BACKGROUND

[0001] A fastener is a connector between structural members and may refer to a mechanical medium or device that mechanically joins or affixes two or more objects together. Fasteners may be used to form a joining between parts and may resist shear and bending. Fasteners can be used in different applications such as electronics, casings, wood constructions, and other applications in various fields of art. A variety of different designs and materials can be implemented for the fastener for different applications or features, which may include bolts, screws, pins and rivets.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIGS. 1 A and 1 B are perspective views of a fastener according to an example.

[0003] FIGS. 2A-2D illustrate examples of the fastener respectively having different shank structures.

[0004] Fig. 3A and 3B illustrate examples of the fastener including a tamper- resist part.

[0005] Fig. 3C illustrates a tamper-resist part movably provided within a cavity, according to an example.

[0006] FIGS. 4A illustrates the fastener including a main body and a drive head joined with a female portion, according to an example.

[0007] FIGS. 4B illustrates a main body of the fastener fastened to a female portion after a drive head of the fastener sheared off from the main body of the fastener, according to an example. [0008] Fig. 5A illustrates a female portion corresponding to the fastener, where the shank and/or the female portion is/are plasticizable or moldable, according to an example.

[0009] Fig. 5B illustrates a sink of a female portion corresponding to the fastener that partially covers the main end portion of the fastener according to an example.

[0010] Fig. 6A illustrates the fastener being fastened to a female portion corresponding to the fastener, where arrows indicate directions of force while the fastener is being fastened to the female portion, according to an example.

[0011] Fig. 6B illustrates an annular cross-section of a stress concentrator of the fastener along the dotted line as illustrated in Fig. 6A.

[0012] Fig. 7 illustrates an example of the fastener 1 having structures to resist the unfastening of the fastened fastener 1 according to an example.

[0013] Fig. 8 illustrates an example of structural arrangements of the protrusion 125 and the thread profile of the thread 111.

DETAILED DESCRIPTION

[0014] Reference will now be made in detail to examples, examples of which are illustrated in the accompanying drawings. In this disclosure, when the specification states that one constituent element is "connected to" another constituent element, it includes a case in which the two constituent elements are connected to each other with another constituent element intervened therebetween as well as a case in which the two constituent elements are directly connected to each other. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

[0015] According to an example, a variety of different designs and materials can be implemented for a fastener 1 . For example, the fastener 1 may be a threaded, partially threaded or unthreaded fastener. The fastener 1 may be a type of bolted connections to fasten two elements together. For example, the fastener 1 may be a threaded, partially threaded or unthreaded bolt that can be inserted, tightened or bolted into an opening or a mating thread or can be used in conjunction with nuts. For example, the fastener 1 may be a threaded, partially threaded or unthreaded screw or its related type. The fastener 1 may be a pin that is not threaded and can be used to keep two or more elements in alignment. For example, the fastener 1 may be a rivet type fastener or a nail type faster. A fastener according to an example may include various types of fasteners including clips, rivets and locking features.

[0016] According to an example, the fastener 1 may be made of and/or include different types of materials. For example, the fastener 1 may be made of or include plastic. For example, the fastener 1 may comprise one or more of ferrous materials such as steel, non-ferrous inorganic materials such as aluminum, and brass, and/or organic materials such as plastics. For example, the fastener 1 may be made of or include metal or a metal alloy such as aluminum, brass, and/or steel including carbon steel, alloy steel, stainless steel, corrosion-resistant (CRES) steel, and high nickel corrosion resistant stainless steel. For example, the fastener 1 may be made of or include a material other than metal, such as plastic resin such as a moldable/molded engineering plastic, polycarbonate, polyamide, polyurethane, and polyethyleneterapthalate (PET) in any available grades, wood, and/or fiber. One or more types of materials, including the materials listed above, can be combined or mixed to make, construct or manufacture the fastener 1. According to an example, the fastener 1 may receive subsequent coatings or plating, such as chrome, nickel, cadmium, thread locker, thread lubricants, etc. The fastener 1 may be formed from one or combinations of various processes such as forging, cutting, forming, casting, milling, etc.

[0017] According to an example, the fastener 1 may be used to create a non permanent joint or non-permanent joints, which can be removed, unfastened, disjoined, or dismantled without damaging the joining components. For example, the fastener 1 may be a removable fastener such as a removable bolt or screw. [0018] According to an example, the fastener 1 may be used to create a permanent joint or permanent joints, which may discourage, suppress, block, interfere or hinder removing, unfastening, disjointing or dismantling, for example, without damaging the joining components. For example, the fastener 1 may be a non-removable fastener such as a non-removable bolt or screw.

[0019] According to an example, the fastener 1 for creating a permanent joint or the fastener 1 as a non-removable fastener 1 , locking fastener 1 , tamper- resist fastener 1 , anti-drilling fastener 1 , anti-tampering fastener 1 , and/or security fastener 1 may be used for a variety of purposes, such as for securing fasteners as well as for the anti-tampering, theft and vandalism protection, joint securing context. The fastener 1 for creating a permanent joint or the non removable fastener 1 may be used for construction parts, wood workings, electronics, various casings including casings for electronics, or consumable for electronics. According to an example, various types of fasteners can be implemented and/or modified as the fastener 1 to discourage tampering or unintended, unnecessary, unauthorized removal of the fastener 1 fastened to create a permanent joint, for example, to protect potential damages resulted from removing the permanent joint.

[0020] According to an example, the fastener 1 may include a main body 100 and a drive head 200 that is removable from the main body 100. The drive head is to receive force applied to fasten the fastener 1. According to an example, the fastener 1 may further include a stress concentrator 300, as a stress concentrating portion 300, stress concentrating bridge 300, and/or stress concentrating joint 300, which connects and joins the drive head 200 and the main body 100. According to an example, the drive head 200 may include a stress concentrator 300 formed on the main end portion 120, wherein the stress concentrator 300 is to be torn when the threshold amount of force is applied to the drive head. According to an example, the drive head 200 may include a stress concentrator 300 formed on the main end portion 120, wherein the stress concentrator is to be torn by the threshold amount of force applied to the drive head. According to an example, the drive head 200 may include a stress concentrator 300 formed on and/or coupled to the main end portion 120 included in the main body 100. According to an example, the main end portion 120 may include a stress concentrator 300 formed on and/or coupled to the drive head 200. According to an example, the stress concentrator 300 may be provided between the main end portion 120 and the drive head 200. According to an example, the stress concentrator 300 is to be deformed, torn, ruptured, sheared off, and/or divided by the threshold amount of force applied to the drive head, detaching the drive head 200 from the main body 100. According to an example, the drive head 200 may include a stress concentrator 300 formed on the main end portion 120, wherein the stress concentrator 300 is to be torn through when the threshold amount of force is applied to the drive head 200. According to an example, the drive head 200 may include a stress concentrator 300 formed on the main end portion 120, wherein the stress concentrator 300 is to be torn through repeatedly and consistently, at about a constant force level when the threshold amount of force is applied to the drive head 200.

[0021] According to an example, the fastener 1 may include a main body 100 including a shank 110 and a main end portion 120. The fastener 1 may include a drive head 200 extending from the main end portion 120. The main end portion 120 may be one end of the main body 100 from which the removable drive head 200 is extending from. The main end portion 120 may be one end of the main body 100 that is connected to the removable drive head 200 or to a part connecting the main body 100 and the drive head 200. For example, the main end portion 120 may be a main fastener head 120 of the fastener 1 that is not designed to be removed from the main body 100 of the fastener 1.

According to an example, the main end portion 120 may include a main fastener head 120 having a lower surface from which the shank 110 extends. In the case of the main body 100 forming a headless-type fastener, the main end portion 120 may be an end of the shank 110 toward the removable drive head 200 or a portion formed on an end of the shank 110 or between the shank 110 and the drive head 200. The shank 110 of the main body 100 means a portion of the fastener 1 under the main end portion 120, such as a portion under the main fastener head 120, and/or a male portion to be inserted into a female portion 500, bossing 500 or nut 500 to form the fastener joining, and/or a portion forming a shaft portion of the fastener 1. For example, in the case of the main body 100 forming a headless-type fastener, the main body 100 itself or the entire portion of the main body 100 may form the shank 110, or a portion of the main body 100 forming the shaft-shaped portion or the male portion may be the shank 110.

[0022] According to an example, FIGS. 1 A and 1 B are perspective views of the fastener 1 according to an example.

[0023] As shown in FIGS. 1 A and 1 B, the fastener 1 according to an example includes the main body 100 and the drive head 200 extending from or connected to the main body and is removable from the main body 100 or can shear off from the main body 100. According to an example, various types and/or structures of fasteners can be implemented or based for the structure or shape of the main body 100. For example, the main body 100 may be a screw- type, pin-type or bolt-type or their related structure. A bolt-type of the main body 100 is shown in FIGS. 1A and 1 B as an example. According to an example, the fastener 1 as shown in FIGS. 1Aand 1 B is provided with a plurality of heads 200 and 120. One head 200 among the plurality of heads 200 and 120 can shear off from the main body 100 of the fastener 1 when a certain amount of force such as torque is applied. A threshold amount of the force or torque may be set for the fastener 1.

[0024] As shown in FIGS. 1 A and 1 B, the fastener 1 may include a main body 100 that includes a shank 110 and a main end portion 120 and a drive head 200 extending from the main end portion 120.

[0025] According to an example, the main body 100 may take different forms or shapes depending on its intended application. The main body 100 of the fastener 1 may be a type of fastener that does not have a main fastener head or being a headless fastener type. If a type of fastener that does not have a main fastener head or being a headless fastener type, a portion of the main body 100 connected to the drive head 200, or a portion from which the removable drive head 200 is connected to, attached to, formed on, and/or extending from, or a portion around the removable drive head 200, is the main end portion 120 of the main body 100. For example, Fig. 2A is a perspective view of the fastener 1 having the main body 100 being a headless fastener type. As shown in Fig. 2A, the main body 100 has the main end portion 120 that is not in a shape of a fastener head and connected to the removable drive head 200 via the stress concentrator 300. As shown in Fig. 2A, when the drive head 200 shears off from the main body 100, the main body 100 becomes a type of fastener that does not have a main fastener head or that is a headless fastener type.

[0026] According to an example, the shank 110 or the bolt shaft 110 may take different forms or shapes, such as different diameters and lengths, depending on its intended application. For example, FIGS. 1 A-1 B and 2A-2D illustrate different types of the fastener 1 having different shank 110 structures. As shown in FIGS. 1A and 1 B, the shank 110 may form a bolt-type structure. As shown in Fig. 2C, the shank 110 may form a threadless shank, such as a pin-type structure. As shown in Fig. 2D, the shank 110 may form a screw-type structure.

[0027] For example, in the case of the main body 100 forming a headless- type fastener, the main body 100 itself or the entire portion of the main body 100 may form the shank 110, or a portion of the main body 100 forming the shaft shaped portion or the male portion may correspond to the shank 110. For example, Fig. 2A illustrates an example of the shank 110 being a major portion of the main body 100 in a headless type fastener along with the removable drive head 200. According to an example, the shank 110 may include a thread 111 , unthreaded portion 112 or both of the thread 111 and unthreaded portion 112. The thread 111 or the threaded portion may be a left-hand thread or a right-hand thread. For example, the entire portion of the shank 110 or most portion of the shank 110 may be threaded to form the thread 111 , or only a portion of the shank 110 may be threaded to form the thread 111 , or the entire portion of the shank 110 may not be threaded to form the unthreaded portion 112. As shown in Fig. 1A, the entire portion of the shank 110 may be threaded. As shown in Fig. 1 B, the shank 110 may be partially threaded and include the threaded portion 111 and the unthreaded portion 112. As shown in Fig. 2C, the shank 110 may be unthreaded and include the unthreaded portion 112. [0028] According to an example, the thread 111 may be based on general thread types, such as unified fine pitch threads (UNF), unified coarse thread (UNC), etc. The thread 111 may be based on a specific thread type, such as buttress, acme, etc. For example, the thread 111 may be formed in a general helical manner or follow splines or polynomial elements. The thread 111 may be tapered similar to National Pipe Tapered threads (NPT).

[0029] According to an example, the drive head 200 may include a drive portion 210 through which a force can be applied or transferred. The drive portion 210 may be arranged to receive various types of force, for example, in various directions, such as torque, pushing force, and/or pulling force. For example, the drive portion 210 may be formed around a side surface of the drive head or formed on an upper surface of the drive head. The drive portion 210 may be an outer profile of the drive head 200 at which a torque tool may engage. The drive portion 210 may be in a form of a protrusion, surface pattern, recess or void having a variety of shapes such as a polygonal, circular, cross, or linear shape. For example, the drive portion 210 may be a recess formed on the upper surface of the drive head 200. For example, the drive format of the drive portion 210 may be based on internal or external drive features, such as TORX®, Philips, Common, Square, hex drive (Hex head), etc. For example, as shown in Fig. 1 B, the drive head 200 including the drive portion 210 may be a hexagonal head for actuation by a wrench or a ratchet nut. The drive head 200 may attach to and/or be extended from the main end portion 120 through the stress concentrator 300. For example, as shown in Fig. 1 B, the drive portion 210 may be a recess having a cross-sectional shape of a hexagon.

[0030] The drive head 200 may be separated from or removable from the main end portion 120 when a threshold amount of force is applied to the drive head 200. According to an example, the fastener 1 may include a stress concentrator 300. In this case, the drive head 200 and the main end portion 120 are connected, coupled, and/or bridged through the stress concentrator 300. When the threshold amount of force is applied, the threshold amount of force causes the stress to the stress concentrator 300 to shear off. [0031] According to an example, the main end portion 120 of the fastener 1 may include a structure or material for a permanent joint. The fastener 1 may be used to create a permanent joint or permanent joints, which may discourage, suppress and/or hinder removing, unfastening, disjointing and/or dismantling, for example, and/or further securing the joining components, for example, from potential damages. For example, the fastener 1 may be a non-removable fastener such as a non-removable bolt or screw. The main end portion 120 of the fastener 1 may be designed for the purpose of the permanent joining or for being the non-removable fastener 1 .

[0032] According to an example, the main end portion 120 may include a cavity 122 and a tamper-resist part 121 embedded in the cavity 122. The tamper-resist part 121 is to hinder the unfastening or removal attempt of the fastener 1 that already formed the permanent joint after the drive head 200 is sheared off or removed from the main end portion. For example, the tamper- resist part 121 may include a material or structure that hinders the force from being applied to the main end portion to suppress unfastening of the fastener 1 , or that hinders the reshaping, remolding or recessing at least a portion of the main end portion 120 or the tamper-resist part 121. According to an example, the tamper-resist part 121 may be placed in cavity 122 in a variety of different ways. For example, the tamper-resist part 121 may be welded, soldered, swedged, or press-fitted in the cavity 122.

[0033] According to an example, the fastener 1 may include a main body 100 including a shank 110 and a main end portion 120, a drive head 200 extending from the main end portion 120 and removable from the main end portion 120 when a threshold amount of force is applied to the drive head 200, and a tamper-resist part 121 embedded in a cavity 122 provided in the main end portion 120.

[0034] According to an example, a variety of different structures or shapes may be implemented in forming the tamper-resist part 121. For example, the tamper-resist part 121 may have a shape based on a sphere, cube, cuboid, cylinder, prism, cone, pyramid, ring or any combination thereof. According to an example, the tamper-resist part 121 may be provided in the cavity 122 to be movable to hinder the force to be applied to the main end portion 120. For example, the tamper-resist part 121 may be rotatable in the cavity 122. For example, the tamper-resist part 121 may be provided to be rotatable, such that rotational force applied toward the main end portion to rotate and unfasten the main body 100 of the fastener 1 . For example, a force such as torque applied by a tool such as a screw driver or ranch contacting the surface of the tamper- resist part 121 , may be diverted by a rotation of the tamper-resist part 121 provided in the cavity 122 to be rotatable. For example, the tamper-resist part 121 may have a shape corresponding to a sphere, ring, or cylinder, to be rotatable at the main end portion 120.

[0035] The tamper-resist part 121 may be made of a material, mixture of materials, or chemical compound. For example, tamper-resist part 121 may be made of at least one material including steel such as hardened tool steel, a metal alloy such as tungsten carbide, ceramic, a compound having a molecular arrangement of carbon molecules such as diamonds and carbon fibers, nano scale carbon or material structure such as nanotube, nanofiber or nanosheet, and/or moldable resins such as plastics, or any combination thereof, or any variety of materials.

[0036] According to an example, various shapes may be implemented as the shape of the tamper-resist part 121 , which may be provided to be movable or static. According to an example, the tamper-resist part 121 may be provided to be movable, rotatable or spinnable within the cavity 122. For example, the tamper-resist part 121 may be movable in the cavity 122. For example, the tamper-resist part 121 is rotatable in the cavity 122.

[0037] For example, the tamper-resist part 121 provided to be movable may deter or divert force applied to the main end portion 120 provided including the sphere-shaped tamper-resist part 121. For example, when a torque applying tool, such as a driver or screw extractor, is used to apply torque tamper, disjoin or unfasten the fastener 1 , or when a tool to reshape, modify, recess, or drill into the main end portion 120, such as a drill or extractor drill bit, the tamper-resist part 121 is to be contacted by such tools contacting the main end portion 120 of the fastener 1 , and the torque applied by such tools is to be applied at least partially to the tamper-resist part 121 or the sphere 121 may be spun by the torque applied, thereby diverting the torque from being applied to the main end portion 120, thereby providing a tamper-resist function.

[0038] According to an example, various shapes may be implemented as the shape of the tamper-resist part 121 , which may be provided to be movable or static. Fig. 3Aand 3B illustrate examples of the fastener 1 including the tamper- resist part 121 according to an example. As shown in Fig. 3A, the tamper-resist part 121 may be provided in a sphere shape. The sphere-shaped tamper-resist part 121 may be provided to be static or provided to be movable. As shown in Fig. 3B, the tamper-resist part 121 may be in a cuboid or cylinder shape.

[0039] For example, Fig. 3C illustrates the tamper-resist part 121 movably provided within the cavity 122. As shown in Fig. 3C, the cavity 122 is provided in a shape that has a first space 1221 to house the sphere 121 and a second space 1222 extending through the main end portion 120 and the drive head 200. After the drive head 200 shears off or removed from the fastener 1 , the cross-section of the second space 1222 formed by the removal of the drive head 200 is to have a size, a cross-sectional area or a diameter smaller than the size or diameter of the tamper-resist part 121 , so as to hold the tamper- resist part 121 to stay and be movable in the cavity 122.

[0040] According to an example, the main end portion 120 may include a first material having a first hardness, and the tamper-resist part 121 may include a second material having a second hardness different from the first hardness.

[0041] According to an example, the tamper-resist part 121 may include a material having a mechanical property — such as strength, stiffness, hardness, and/or toughness — that is sufficient to withstand or resist a physical reshaping or remolding of the main end portion 120, such as drilling, recessing, pressing or shear force-based, friction-based or traction-based unfastening. According to an example, the main end portion 120 may include a first material having a first mechanical property, and the tamper-resist part 121 may include a second material having a second mechanical property different from — e.g., softer than or harder than, weaker than or stronger than, etc. — the first mechanical property. According to an example, the main end portion 120 may include a first material having a first mechanical property, and the tamper-resist part 121 may include a second material having a second mechanical property same as or substantially same as the first hardness. For example, the tamper-resist part 121 embedded in the cavity 122 is to be at least partially exposed on a surface of the main end portion 120 when the drive head 200 is removed from the main end portion 120, wherein the surface of the main end portion 120 has a first mechanical property and the tamper-resist part 121 includes a material having a second mechanical property different from the first mechanical property. For example, the tamper-resist part 121 embedded in the cavity 122 may be at least partially exposed on a surface of the main end portion 120, where the surface of the main end portion 120 has a first mechanical property, and the tamper-resist part 121 may include a material having a second mechanical property higher, more, stronger, and/or harder than, or same as the first mechanical property.

For example, the main end portion 120 may include a first material having a first hardness or a first toughness, and the tamper-resist part 121 may include a second material having a second hardness or a second toughness different from — e.g. , higher than or lower than — the first hardness or the first toughness. For example, the main end portion 120 may include a first material having a first hardness or a first toughness, and the tamper-resist part 121 may include a second material having a second hardness or a second toughness same as or substantially same as the first hardness or the first toughness. For example, the tamper-resist part 121 embedded in the cavity 122 is to be at least partially exposed on a surface of the main end portion 120 when the drive head 200 is removed from the main end portion 120, wherein the surface of the main end portion 120 has a first hardness (or toughness) and the tamper-resist part 121 includes a material having a second hardness (or toughness) different from the first hardness (or toughness). For example, the tamper-resist part 121 embedded in the cavity 122 may be at least partially exposed on a surface of the main end portion 120, where the surface of the main end portion 120 has a first hardness (or toughness), and the tamper-resist part 121 may include a material having a second hardness (or toughness) harder than, softer than or substantially same as the first hardness (or toughness).

[0042] For example, the tamper-resist part 121 , such as the tamper-resist parts 121 shown in Fig. 3A or Fig. 3B may include or be made of material having a high level of hardness, such as hardened tool steel, tungsten carbide, ceramic, or diamond. According to an example, the tamper-resist part 121 including or made of the material having the high level hardness may be provided to be static or movable.

[0043] According to an example, the shank 110 of the main body 100 may be fastened or inserted into a medium by being screwed, bolted, spun, forced, drilled or pushed into the medium. According to an example, the shank 110 of the main body 100 may be fastened to or inserted into a corresponding female portion 500, such as bossing 500 or nut 500, to form the fastener joining by the fastener 1. For example, Fig. 4A illustrates the fastener 1 including the main body 100 the drive head 200 joined with the female portion 500. FIGS. 4B illustrates the main body 100 of the fastener 1 fastened to the female portion 500 after the drive head sheared off from the main body 100.

[0044] According to an example, anti-unfastening features in addition to the tampering-resist part 121 , such as anti-rotation features as well as features to prevent unfastening, removal or tampering by drilling can also be incorporated into the design of the fastener 1 to prevent loosening of fasteners by vibration, creep or tampering.

[0045] For example, the female portion 500 may include a structure or material that will provide an additional tamper-resist feature. For example, the main body 100 such as the shank 110 may include material that may be replasticized, fuse with or be re-moldable with respect to a portion of the fastener 1 fastened to the female portion 500. For example, the female 500 portion may include material that may be replasticized, fuse with or be re- moldable with respect to a portion of the fastener 1 fastened to the female portion 500. According to an example, the fastener 1 may include a feature to provide a space, such as a relief cut having the relief depth 111-1 as a relief space for the plasticizable material such as plastic to flow back into after the plastic stress during fastening the fastener 1 relieves, thereby allowing a relatively less force for fastening while making extracting the fastened fastener 1 more difficult, especially after the plastic has stress relieved. According to an example, varying thread profiles such as having the first thread profile 111 and the second thread profile 1112 or varying the cross-sectional shape(s) of the shank may provide the relief space. For example, the female portion may have a structure, such as a sink or counter sink for counter-sinking, that covers at least a portion of the fastener 1 , to further barrier or hinder the access to a portion of the fastener fastened to the female portion 500. For example, Fig. 5A illustrates the shank 110 or the female portion 500 having a replasticizable and/or moldable portion that may be replasticized or molded around the surface of the shank 110 or the thread 111 of the fastener 1 , according to an example. As shown in Fig. 5A, the moldable inner-portion may be remolded or fused onto a surface of the thread 111 to provide additional hold.

[0046] For example, Fig. 5B illustrates a sink 510 that partially covers the main end portion 120 according to an example. As shown in Fig. 5B, the sink 510 or the countersink 510 covers at least a portion of the main end portion 120 of the fastener 1 , to further barrier or hinder the access to the main end portion 120 of the fastener fastened to the female portion 500.

[0047] According to an example, when parts are assembled with the fastener 1 , a set level of force such as torque may be applied based on the structure of the fastener 1 . Too much torque can damage the fastener 1 and or parts and too little force such as torque on a fastener can create an unstable joint, which may result in the fastener 1 failing out and causing problems in the larger system. According to an example, as the drive head 200 is separated from the main body 100 of the fastener, the means of applying mechanical force to the fastener 1 is removed and the joint may be considered properly torqued and permanent. [0048] According to an example a threshold amount of force, such as torque, to tear, deform, rupture, separate, shear off and/or remove the drive head 200 around/from the main end portion 120, can be set based on the fastening strength of the fastener 1. According to an example, the fastening strength of the fastener 1 can be controlled by setting the threshold amount of force to tear, deform, rupture, separate, shear off and/or remove the drive head 200.

[0049] According to an example, the threshold amount of the force such as torque may be controlled or set at a level, based on the structure, material, and/or material treatment of the stress concentrator 300. For example, the threshold amount of force such as torque or shearing force may be based on material, geometry and heat treatment with respect to the stress concentrator 300.

[0050] Fig. 6A illustrates the fastener 1 being fastened to the female portion 500, where arrows indicate directions of force while the fastener is being fastened to the female portion 500, according to an example. Fig. 6B illustrates an annular cross-section of the stress concentrator 300 along the dotted line as illustrated in Fig. 6A, where the symbol “D” refers to the outer diameter of the annular cross-section of the stress concentrator 300 and the symbol “d” refers to the inner diameter of the annular cross-section of the stress concentrator 300.

[0051] For example, the threshold amount of the torque to shear off the drive head 200 may be set at a level T _max , based on the following Equation (1):

[0052] Tmax = (TT / 16) Tmax (D ⁴ - d ⁴ ) / D Equation (1 )

[0053] where “D” is the outer diameter of the annular cross-section of the stress concentrator, “d” is the inner diameter of the annular cross-section of the stress concentrator 300, and T _max is a value intrinsic to the ultimate sheer strength of the material forming the stress concentrator 300.

[0054] According to an example, various portions of the fastener 1 may include additional structural features to further discourage, resist or hinder the unfastening attempt of the fastener 1 being fastened into a medium or the female portion 500 and with the drive head removed. For example, the main end portion 120 as a main fastener head 120 may include a structural feature that may further secure the fastening of the fastener 1 , increase holding power of the fastener or may provide additional resistance such as traction or friction to resist the unfastening of the fastened fastener 1. For example, the shank 110 may include a structural feature that may further secure the fastening of the fastener 1 or may provide additional resistance such as traction or friction to resist the unfastening of the fastened fastener 1 .

[0055] For example, an arrangement or variation in the shape of the shank 110 and/or the thread 111 profile may be set in various ways to further provide holding power of the fastener 1 , which includes variables regarding thread type, lead, pitch, start, single thread and twin thread, thread length, length of engagement, nominal hole size, boss structure such as the outside diameter of boss and counterbore width, thread spacing, directionality and/or thread angle. For example, buttress or acme thread types may be implemented.

[0056] According to an example, in case of the fastener 1 being a bolt, screw or related types, a surface of the main fastener head 120 may include a structural feature such as a protrusion, tooth, ramp, or any combination thereof, to provide friction or traction in a direction opposite to the fastening direction or a reverse rotational direction. According to an example, the thread 111 of the fastener 1 may have a directional thread feature that to provide additional resistance or holding power against the unfastening or reverse-rotational direction. According to an example, the structural features of the main fastener head 120 and the shank 110 may be combined to provide a combined holding power and resistance to unfastening.

[0057] According to an example, the fastener 1 may be to be fastened by the force applied in a fastening direction of the fastener 1 , the shank 110 may include a thread 111 having a thread profile, wherein the thread 111 having the thread profile is to cause a first friction against the force in the fastening direction and a second friction higher than the first friction against a reverse force in a direction opposite to the fastening direction. [0058] According to an example, the fastener 1 may be to be fastened by the force applied in a fastening direction of the fastener 1 , the lower surface of the main fastener head 120 may include a protrusion 125 protruding from the lower surface, wherein the protrusion 125 is to contact a surface to cause a first friction against the force in the fastening direction, and a second friction higher than the first friction against a reverse force in a direction opposite to the fastening direction.

[0059] According to an example, the fastener 1 may be fastened by first torque in a fastening direction of the fastener, where the shank 110 may include the thread 111 to generate a first friction against the first torque in the fastening direction, and a second friction higher than the first friction against second torque in an opposite direction opposite to the fastening direction. According to an example, the fastener 1 may be to be fastened by first torque in a fastening direction of the fastener, where the main end portion 120 may be the main fastener head 120 having a lower surface from which the shank 110 extends from, and where the lower surface may include a protrusion 125 protruding from the lower surface to contact another surface to generate a first friction against the first torque in the fastening direction and a second friction higher than the first friction against second torque in a opposite rotational direction opposite to the fastening direction.

[0060] For example, Fig. 7 illustrates an example of the fastener 1 having structures to resist unfastening of the fastened fastener 1 according to an example. As shown in Fig. 7, the main fastener head 120 may include a protrusion 125 protruding from a lower surface of the main fastener head 120. The shank 110 may include a thread 111 having a thread profile that will provide different levels of frictions against different directions of torque. For example, the thread 111 may include a first thread profile 1111 and a second thread profile 1112 different from the first profile to generate different levels of friction against different directions of torque. Fig. 8 illustrates an example of structural arrangements of the thread profile of the thread 111. As shown in Fig. 8, the relief depth 111-1 , relief rake angle 111-2, relief clearance angle 111-3, and/or a number of structural shapes that will provide additional friction against a set direction of torque such as an anti-reverse feature may be set to generate different friction levels of the thread 111 in different torque directions. Moreover, according to an example, providing a space such as a relief cut having the relief depth 111-1 may provide a relief space for the plastic to flow back into after the plastic stress during fastening the fastener 1 relieves, thereby allowing a relatively less force for fastening while further resisting withstanding and/or hindering extracting the fastened fastener 1 , especially after the plastic has stress relieved. According to an example, varying thread profiles such as having the first thread profile 111 and the second thread profile 1112 or varying the cross-sectional shape(s) of the shank may provide the relief space. For example, the relief depth 111-1 may be set between the major and minor diameters of the thread 111. For example, the relief rake angle 111-2 may be set from about 80 degrees to about 90 degrees. For example, the relief clearance angle may be set from 0 degrees to about 20 degrees. According to an example, when the thread 111 and the shank 110 are fastened to a plasticizable material such as plastic, the thread profile of the thread 111 set based on the example illustrated in Fig. 8 may allow reliefs for plasticizable material to flow back into the thread profile, which will provide different levels of frictions against different directions of torque, thereby allowing a relatively less force for fastening while making extracting the fastened fastener 1 more difficult, especially after the plastic has stress relieved.

[0061] The fastener 1 according to an example may be used for various applications in construction parts, wood workings, electronics, various casings including casings for electronics, or consumable for electronics. For example, the fastener 1 according to an example may be used for joining wood panels, doors and road signs. For example, the fastener 1 according to an example may be used for joining parts for electronics and its related consumables. For example, the fastener 1 according to an example can be used in joining casing for communication device components or its casing. For example, For example, the fastener 1 according to an example can be used in joining parts or casings for computing devices such as a personal or business computer or its peripheral devices. For example, the fastener 1 according to an example can be used in joining various casings, devices, components, parts or consumables. For example, the fastener may be fastened to a part of the image forming apparatus or a component couplable to the image forming apparatus. Further, the expression "image forming apparatus" as used herein includes an apparatus that processes printing data generated at a terminal such as a computer communicating through a wired connection or wirelessly, which may be a computer for personal and/or business use, a remote server communicating data across a network or the internet, and/or a wireless mobile device such as a smartphone or tablet, to perform printing. Examples of the image forming apparatus may include particulate-based image forming apparatuses. As an example of an image forming apparatus, electrophotographic image forming apparatuses are used to produce hardcopy documents from electronic data. Toner-based image forming apparatuses are an example. In an electrophotographic image forming apparatus, a pattern of electric charges is formed corresponding to the image to be printed. Charged toner is then attracted to the image pattern to develop the image. The image can then be transferred to a print medium, such as a sheet of paper. The toner can then be securely attached to the print medium and delivered as a hardcopy document. The component couplable to the image forming apparatus may include a consumable component such as a printing cartridge, an ink cartridge, or a waste toner container. The component couplable to the image forming apparatus may include a mechanical device such as a mechanical post-printing processor or device and/or an electronic device such as a controller for a post-processing device. Consumables and components for an image forming apparatus, such as laser jet printer supplies have various parts and features that combine to create components that contribute to the electrophotographic printing process and user satisfaction. For example, laser printer cartridges are assembled using many types of fastening methods including welding, adhesives, screws, bolts, retainers, clips, rivets, locking features and other types of fasteners.

Assembling using fasteners such as bolts and screws is a way of joining parts together. The fastener 1 according to an example is capable of providing a consistent torque during assembly while preventing tampering with supply subassemblies and parts.

[0062] For example, the fastener 1 for an image forming apparatus or for a component for an image forming apparatus such as a consumable cartridge may include the main body 100 including the shank 110 and a main end portion 120, a drive head 200 extending from the main end portion, and a tamper-resist part 121 embedded in a cavity 122 provided in the main end portion120, where the drive head 200 is removable from the main end portion 120 when a threshold amount of force is applied to the drive head 200. According to an example, the fastener 1 may be provided to be fastened to a part of an image forming apparatus, or to a component couplable to the image forming apparatus. For example, the component couplable to the image forming apparatus may include a consumable cartridge.

[0063] According to an example, the fastener 1 may be used in various applications in various fields of technology and engineering, which may include constructions, iron-working, wood-working, metal-working, vehicle building, electronics and casings.

[0064] While various examples have been described with reference to the drawings, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.