CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit under 35 U.S.C. §119(e) of co-pending U.S. Provisional Application No. 63/279,216 entitled “WASHER FABRICATION METHOD” filed November 15, 2021, which is incorporated herein by reference.

TECHNICAL FIELD

[0002] The subject disclosure is directed to new and improved method for fabricating washers. Various types of washers, including wedge-locking washers, can be produced through this method. The method involves forming a washer preform. The washer preform is pretreated with a brazing solution before being stacked with a second washer preform. The two washer preforms are sinter brazed together with a predetermined breakaway strength. Then, the two parts can be separated from one another to form two washers in the final step.

BACKGROUND ART

[0003] Conventional washers are disc shaped objects that include a pair of essentially parallel, flat surfaces with a central hole for a screw shank. The essentially flat characteristic of the parallel surfaces does not facilitate the engagement of one washer to another washer for locking purposes.

[0004] Another type of washer is known as a locking washer. Such washers can be used in a locking system in which the washers are arranged in a pair with cam pattern sides facing and engaging each other. The main cam surface inclination can be larger than the pitch of the threads to cause a positive and efficient locking of a fastening element.

[0005] One particular type of locking washer arrangement involves a locking washer having teeth on one side and cams on the other side. The teeth can engage with a surface of a screw head, nut or an element to be attached. One possible shape is a leaning pyramidal shape. The teeth can extend, radially, on the locking washer surface. The other side of the known lock washers can have a cam pattern.

[0006] Various methods for fabricating washers are known. Conventional washers can be manufactured from a strip blank that is fed to pass several forming or punching stations. The punching stations can utilize various upper and lower tools. In some arrangements, the pattern of teeth can be formed on and can cover, substantially, an upper surface. A pattern of cams can formed on and can cover, substantially, the lower surface of the washer.

[0007] These conventional washer fabrication processes have several disadvantages and problems. For example, undesired displacements can occur between the stations during feeding in the die arrangement to cause the formation of defective washers. In some instances, the total amount of blank material can be quite high. For the case of wedgelocking washers designed for a 2-piece live load assembly, there’s an added step of joining the washers together with a sacrificial adhesive which requires large amounts of cumbersome machinery.

[0008] Furthermore, there can be restrictions related to the cam and teeth cover on each side of the washers, which decreases the possibility of forming load bearing surfaces. Also, the outer periphery can be punched out and can receive a sharp edge, which causes problems in the further processing of the washer. Accordingly, there is a need for an improved washer fabrication process.

DISCLOSURE OF INVENTION

[0009] In various implementations, a method for producing a washer is provided. Metal powder is compacted to form a first washer preform. The first washer preform is pretreated with a brazing solution or a sacrificial metal sheet. The first washer preform is stacked with a second washer preform. The first washer preform is joined to the second washer preform, so that the first washer preform can be separate from the second washer preform by applying a predetermined breakaway stress. The first washer preform is separated from the second washer preform to form the washer from the first washer preform.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. l is a perspective view of a hybrid or standard wedge lock washer in accordance with this disclosure.

[0011] FIG. 2A is a fragmentary side elevation view in cross section of a fastening system in accordance with this disclosure.

[0012] FIG. 2B is a fragmentary side elevation view in cross section of another embodiment of a fastening system in accordance with this disclosure.

[0013] FIG. 2C is a fragmentary side elevation view in cross section of another embodiment of a fastening system in accordance with this disclosure.

[0014] FIG. 2D is a fragmentary side elevation view in cross section of another embodiment of a fastening system in accordance with this disclosure.

[0015] FIG. 3 is a perspective view of another embodiment of a hybrid or standard wedge lock washer in accordance with this disclosure.

[0016] FIG. 4A is a perspective view of another embodiment of a hybrid or standard wedge lock washer in accordance with this disclosure. [0017] FIG. 4B is a fragmentary perspective view of a surface for the embodiment of a hybrid or standard wedge lock washer shown in FIG. 4A.

[0018] FIG. 5 illustrates an embodiment of an exemplary process in accordance with the described subject matter.

MODES FOR CARRYING OUT THE INVENTION

[0019] The subject disclosure is directed to new and improved method for fabricating washers. Various types of washers, including wedge-locking washers, can be produced through this method. The method involves forming a washer preform. The washer preform is pretreated with a brazing solution before being stacked with a second washer preform. The two washer preforms are sinter brazed together with a predetermined breakaway strength. Then, the two parts can be separated from one another to form two washers in the final step. [0020] The detailed description provided below in connection with the appended drawings is intended as a description of examples and is not intended to represent the only forms in which the present examples can be constructed or utilized. The description sets forth functions of the examples and sequences of steps for constructing and operating the examples. However, the same or equivalent functions and sequences can be accomplished by different examples.

[0021] References to “one embodiment,” “an embodiment,” “an example embodiment,” “one implementation,” “an implementation,” “one example,” “an example” and the like, indicate that the described embodiment, implementation or example can include a particular feature, structure or characteristic, but every embodiment, implementation or example can not necessarily include the particular feature, structure or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment, implementation or example. Further, when a particular feature, structure or characteristic is described in connection with an embodiment, implementation or example, it is to be appreciated that such feature, structure or characteristic can be implemented in connection with other embodiments, implementations or examples whether or not explicitly described.

[0022] Numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments of the described subject matter. It is to be appreciated, however, that such embodiments can be practiced without these specific details. [0023] Various features of the subject disclosure are now described in more detail with reference to the drawings, wherein like numerals generally refer to like or corresponding elements throughout. The drawings and detailed description are not intended to limit the claimed subject matter to the particular form described. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the claimed subject matter.

[0024] The disclosure relates to a method for fabricating washers that can be used in various fastening systems. The washer can be made through a modified powder metallurgy process. The process is more efficient than conventional washer fabrication methods and uses less material. The washers can be made from metal powders that use recycled materials. The use of powder metallurgy processes can allow the hybrid or standard wedge lock washer to be made from a wider variety of metals and metal alloys, including metals and metal alloys that cannot be fabricated into washers through conventional processes.

[0025] Referring to FIG. 1, a hybrid or standard wedge lock washer, generally designated by the numeral 100, can be manufactured in accordance with the disclosed process. The hybrid or standard wedge lock washer 100 has an essentially disk-shaped body 110 with an outer ring 112, an inner ring 114, and a bore 116 extending through the inner ring 114. The outer ring 112 can perform the functions of a locking washer. The inner ring 114 can perform the functions of a conventional washer.

[0026] The outer ring 112 is bound by a contoured outer edge 118 and a contoured inner edge 120. The contoured outer edge 118 represents the outer surface of the hybrid or standard wedge lock washer 110 and forms an outer rim for the hybrid or standard wedge lock washer 110. The contoured inner edge 120 represents a boundary between the outer ring 112 and the inner ring 114. The inner ring 114 is bound on the opposite side by the bore 116, which forms an inner rim for the hybrid or standard wedge lock washer 110.

[0027] The outer ring 112 has an engagement surface 122 that functions as a locking washer engagement surface. The engagement surface 122 includes a plurality of wedges 124. Each wedge 124 has a raised edge 126 and lowered edge 128. The wedges 124 are contoured to form a plurality of crests and troughs around the contoured outer edge 118 of the outer ring 112. The crests and troughs can enhance the ability of the outer ring 112 to engage other surfaces, frictionally.

[0028] The wedges 124 abut one another to form a radial pattern on the engagement surface 122. Each raised edge 126 and lowered edge 128 extends radially and perpendicularly from a longitudinal axis, generally identified as D in FIGS. 2A-2D, projecting through the bore 116.

[0029] One exemplary wedge 130 is connected to an abutting wedge 132 by a face 134 that extends perpendicularly from the engagement surface 122. The face 134 is bound by the raised edge 136 on the wedge 130, the lowered edge 138 on the wedge 132, the contoured outer edge 118, and the contoured inner edge 120.

[0030] The inner ring 114 has a pair of essentially flat surfaces 140, 142 on opposite sides of the hybrid or standard wedge lock washer disc-shaped body 110. The essentially flat surfaces 140, 142 provide the inner ring 114 with the ability to function as a conventional washer.

[0031] The outer ring 112 and the inner ring 114 can be made from the same material or different materials. In some embodiments, the outer ring 112 and the inner ring 114 are unitary or integral and/or made from the same mass of material.

[0032] The outer ring 112 and the inner ring 114 can be made from can be made from any suitable material through any suitable manufacturing method. Suitable materials include flexible, semi-flexible, rigid, or semi-rigid materials. Suitable materials also include metals, ceramics, plastics, and composites. Specifically, suitable materials can include metals.

[0033] The metal is selected from the group consisting of carbon steel, spring steel, stainless steel, copper, brass, aluminum, titanium, iron, bronze, zinc, silicon bronze, Inconel, Monel, and Hastelloy.

[0034] The hybrid or standard wedge lock washere 100 is manufactured using a modified powder metallurgy process. Powder metallurgy processes include such processes as powder forging, hot isostatic pressing, metal injection molding, electric current assisted sintering, and additive manufacturing techniques. In such processes, powder metal can be stamped into a blank and put into an oven, so that the particles can be sintered together.

[0035] The powder metallurgy processes can be performed efficiently by using powder that contain a significant amount of recycled metal contents and by producing less waste material through the production of net shape or near-net shape products.

[0036] Referring now to FIGS. 2A-2D with continuing reference to the foregoing figures, various embodiments of a fastening system, generally designated by the numerals 200A- 200D, are shown. The embodiments of the fastening systems 200A-200D include hybrid or standard wedge lock washers 210A-210D that have the ability to function as either a conventional washer or a locking washer. The hybrid or standard wedge lock washers 210A- 210D are essentially identical to the hybrid or standard wedge lock washer 100 shown in FIG. 1.

[0037] The fastening systems 200A-200D include the hybrid or standard wedge lock washers 210A-210D, a shank member 212, a nut 214, and a bearing element 216. The shank member 212 connects the nut 214 to the bearing element 216. The nut 214 is positioned at one end 218 of the shank member 212. The bearing element 216 includes a hole 220 that receives the other end 222 of the shank member 212. In these exemplary embodiments, the shank member 212 is threaded and the bearing element hole 220 is configured to receive the threaded shank member 212.

[0038] Referring to FIG. 2A, an embodiment of the fastening system 200A is shown in which the hybrid or standard wedge lock washer 210A functions like a conventional washer between the nut 214 and the bearing element 216. The shank member 212 inserts through a bore 224A in the hybrid or standard wedge lock washer 210A. The bore 224A is essentially identical to the bore 116 shown in FIG. 1.

[0039] In this exemplary embodiment, a bottom surface 226A of the hybrid or standard wedge lock washer 210A abuts an upper surface 228 of the bearing element 216. The hybrid or standard wedge lock washer bottom surface 226A is an essentially flat surface that is essentially identical to the flat surface 142 shown in FIG. 1.

[0040] Unlike known fastening system that include a conventional washer, the fastening system 200 A can be configured to have an engagement surface 230 A frictionally engaging the nut 214 to provide an additional locking capability within the fastening system 200 A. The frictional engagement of the engagement surface 230 A against the nut 214 can lock or fix the shank member 212 into place between the nut 214 and the bearing element 216. The engagement surface 230 A can be essentially identical to the engagement surface 122 shown in FIG. 1.

[0041] Referring to FIG. 2B, another embodiment of the fastening system 200B is shown in which the hybrid or standard wedge lock washer 210B functions like a locking washer between the nut 214 and the bearing element 216. The shank member 212 inserts through a bore 224B in the hybrid or standard wedge lock washer 210B. The bore 224B is essentially identical to the bore 116 shown in FIG. 1.

[0042] In this exemplary embodiment, the hybrid or standard wedge lock washer 210B is positioned in an upside down configuration in which an essentially flat hybrid or standard wedge lock washer bottom surface 226B engages the nut 214. The upper surface 228 of the bearing element 216 abuts an engagement surface 230B for the hybrid or standard wedge lock washer 210B to lock or to fix the shank member 212 in place.

[0043] The engagement surface 230B of the hybrid or standard wedge lock washer 210B can deform the upper surface 228 either permanently or temporarily when the hybrid or standard wedge lock washer 210B is made from a material that is harder than the material for which the bearing element 216 is made. The configuration is particularly useful when the bearing element 216 is made from wood or plastic and the hybrid or standard wedge lock washer 21 OB is made from a metal that is harder than wood or plastic.

[0044] Referring to FIG. 2C, another embodiment of the fastening system 200C is shown. The fastening system 200C is particularly adapted for applications in which there is a significant amount of vibration. In this exemplary embodiment, a hybrid or standard wedge lock washer 210C and a locking washer 232C are positioned between the nut 214 and the bearing element 216. The shank member 212 inserts through both the hybrid or standard wedge lock washer 210C and the locking washer 232C.

[0045] The hybrid or standard wedge lock washer 210C is with its engagement surface 230C facing the nut 214 and a mating surface 234C on the locking washer 232C facing the bearing element 216. The engagement surface 230C abuts the mating surface 234C, so that the surfaces are frictionally engaged.

[0046] The engagement surface 230C and the mating surface 234C can be contoured with a plurality of crests and troughs in the same manner in which the engagement surface 122 shown in FIG. 1 is contoured. In some embodiments, the mating surface 234C is contoured to form a plurality of crests for inserting into troughs on the engagement surface 230C.

Similarly, the mating surface 234C can be contoured to form a plurality of troughs for receiving crests on the engagement surface 230C to lock the hybrid or standard wedge lock washer 210C against the locking washer 232C. In such embodiments, the engagement surface 230C and the mating surface 234C are interlocking, so that the hybrid or standard wedge lock washer 210C does not slip against the locking washer 232C, particularly when the environment includes a significant amount of vibration.

[0047] It should be understood that fastening system 200C can be configured with the hybrid or standard wedge lock washer 210C and the locking washer 232C in opposite positions. In such embodiments, the hybrid or standard wedge lock washer 210C abuts the nut 214 and the locking washer 232C abuts the bearing element 216. The engagement surface 230C abuts and frictionally engages the mating surface 234C.

[0048] Referring to FIG. 2D, another embodiment of the fastening system 200D is shown. Like the embodiment shown in FIG. 2C, the fastening system 200D is particularly adapted for applications in which there is a significant amount of vibration. Unlike the embodiment shown in FIG. 2C, the fastening system 200D includes two identical hybrid or standard wedge lock washers 210D positioned with the engagement surfaces 230D facing one another in abutment and in frictional engagement. [0049] It should be understood that any of the fastening systems 200A-200D shown in FIGS. 2A-2D can be sold as individual components individually or in groups of individual components. It should also be understood that the fastening systems 200A-200D can be sold in kits in unassembled, partially assembled, or fully assembled form.

[0050] Referring to FIG. 3, another embodiment of a hybrid or standard wedge lock washer, generally designated by the numeral 300, can be manufactured using a modified powder metallurgy process. Like the hybrid or standard wedge lock washer 100 shown in FIG. 1, the hybrid or standard wedge lock washer 300 has an essentially disk-shaped body 310 with an outer ring 312, an inner ring 314, and a bore 316 extending through the inner ring 314. The outer ring 312 can perform the functions of a locking washer. The inner ring 314 can perform the functions of a conventional washer.

[0051] Unlike the embodiment shown in FIG. 1, the hybrid or standard wedge lock washer 300 includes a recess 318 separating the outer ring 312 from the inner ring 314. In this exemplary embodiment, the recess 318 is essentially circular and is positioned between the outer ring 312 and the inner ring 314. The outer ring 312, the inner ring 314, the bore 316, and the recess 318 are essentially concentric with one another. The inclusion of the recess 318, which can be a drafted recess, can make it easier to fabricate the hybrid or standard wedge lock washer 300 using conventional tooling and/or fabrication methods.

[0052] In some embodiments, the inner ring 314 can be omitted entirely, so that the bore 316 extends to an inner edge on the outer ring 312.

[0053] Referring to FIGS. 4A-4B, another embodiment of a hybrid or standard wedge lock washer, generally designated by the numeral 400, can be manufactured using a modified powder metallurgy process. Like the hybrid or standard wedge lock washer 100 shown in FIG. 1 and the hybrid or standard wedge lock washer 300 shown in FIG. 3, the hybrid or standard wedge lock washer 400 has an essentially disk-shaped body 410.

[0054] Unlike the embodiments shown in FIG. 1 and FIG. 3, the hybrid or standard wedge lock washer 400 is configured to be countersunk into a base 412. In this embodiment, the base 412 is a spherical countersunk base. As shown in FIGS. 4A-4B, an upper surface 414 of the hybrid or standard wedge lock washer 400 can include an engagement surface 416 that is similar in appearance with the outer ring 312 of the hybrid or standard wedge lock washer 300 shown in FIG. 3.

[0055] Further, it should be understood that, in some embodiments, the base 412 can include wedged on an upper surface to provide for use with a standard washer top. [0056] Referring to FIG. 5 with continuing reference to the foregoing figures, a method 500 for making a washer in accordance with the described subject matter is shown. In this exemplary embodiment, the washer can be essentially identical to the hybrid or standard wedge lock washer 100 shown in FIG. 1, to the hybrid or standard wedge lock washers 210A- 210D shown in FIGS. 2A-2D, to the hybrid or standard wedge lock washer 300 shown in FIG. 3, and/or to the hybrid or standard wedge lock washer 400 shown in FIGS. 4A-4B.

[0057] The method 500 can also be used to form conventional washers. In some embodiments, the washer can have the configuration of the washer shown in U.S. Design Patent No. D602,349, which is incorporated by reference.

[0058] At 501, a metal powder is formed. In this exemplary embodiment, the metal powder can be formed of multiple metals to facilitate the formation of a hybrid or standard wedge lock washer that is formed from a metal alloy.

[0059] At 502, a metal powder is compacted into a washer preform. In this exemplary embodiment, the compacting step can be performed through any conventional or unconventional powder metallurgy compacting step. In some embodiments, Step 502 is performed in a flexible mold.

[0060] At 503, the washer preform is pretreated with a brazing solution. The brazing solution can be any one solution or combination of solutions that are commonly used in brazing operations. The brazing solution is selected to be compatible or otherwise useful with the material that forms the washer preform.

[0061] At 504, the washer preform is a first washer preform that is stacked with a second washer preform. In this exemplary embodiment, the first washer preform is essentially identical to the second washer preform.

[0062] At 505, the first washer preform is joined to the second washer preform, so that the preforms have a predetermined breakaway stress. In this exemplary embodiment, the first washer preform is sinter brazed to the second washer preform. In other embodiments, the first washer perform is joined to the second washer preform in a series of joint sub steps that include sintering and brazing.

[0063] The predetermined breakaway stress between the first washer preform and the second washer preform that is produced in Step 505 should be sufficient to allow the first washer preform to separate from the second washer preform under live fastening loads. In some embodiments, the joined first washer preform and second washer preform can be plated with a metal, a metal alloy, or a metal compound. In this exemplary embodiment, the metal, metal alloy, or metal compound can include zinc, chrome, gold, or other suitable metal, metal alloy, or metal compound.

[0064] At 506, the first washer preform and the second washer preform can be separated with the first washer preform forming a washer having an essentially disk-shaped body with an outer ring and an inner bore extending therethrough. The outer ring includes an engagement face with a plurality of wedges forming a plurality of crests and troughs.

[0065] The process 500 can utilize metal powder raw materials, such as iron powder, nickel powder, and chromium powder, as well as alloys thereof, to form the washer preforms. The powder can include various additives, such as additives such as lubricant wax, carbon, and/or copper.

[0066] The process 500 can form metal parts that include various alloys and elemental metals, such as iron, iron alloys, nickel alloys, and chromium alloys. Suitable iron alloys include cast irons, gray irons, white irons, ductile irons, malleable irons, wrought iron, steels, crucible steels, carbon steels, spring steels, alloy steels, maraging steels, stainless steels, weathering steels, tool steels, and other specialty steels Suitable nickel alloys include chromel, ferronickel, hastelloys, inconels, monels, nichrome, and nickel-carbon alloys. Suitable chromium alloys include chromium hydride and ferrochrome. The alloys can be superalloys and/or high performance alloys.

Supported Features and Embodiments

[0067] The detailed description provided above in connection with the appended drawings explicitly describes and supports various features of a method for fabricating a washer. By way of illustration and not limitation, supported embodiments include a method of producing a washer, the method comprising: compacting metal powder to form a first washer preform; pretreating the first washer preform with a brazing solution; stacking the first washer preform with a second washer preform; joining the first washer preform to the second washer preform, so that the first washer preform can be separate from the second washer preform by applying a predetermined breakaway stress; and separating the first washer preform from the second washer preform to form the washer from the first washer preform.

[0068] Supported embodiments include the foregoing method, further comprising: forming the metal powder from a plurality of metal components selected from the group consisting of elemental metals, alloys, and metal compounds. [0069] Supported embodiments include any of the foregoing methods, wherein the first washer preform is essentially identical to the second washer preform.

[0070] Supported embodiments include any of the foregoing methods, wherein the joining step includes sinter brazing the first washer preform to the second washer preform. [0071] Supported embodiments include any of the foregoing methods, wherein the joining step includes sintering the first washer preform to the second washer preform and brazing the first washer preform to the second washer preform.

[0072] Supported embodiments include any of the foregoing methods, further comprising: plating the first washer preform and the second washer preform with a metal mixture after the first washer preform was joined to the second washer preform.

[0073] Supported embodiments include any of the foregoing methods, wherein the metal mixture includes a metal component selected from the group consisting of an elemental metal, an alloy, and a metal compound.

[0074] Supported embodiments include any of the foregoing methods, wherein the washer is a hybrid or standard wedge lock washer.

[0075] Supported embodiments include any of the foregoing methods, wherein the hybrid or standard wedge lock washer includes an essentially disk-shaped body with an outer ring and an inner bore extending therethrough; and wherein the outer ring includes an engagement face with a plurality of wedges forming a plurality of crests and troughs.

[0076] Supported embodiments include a product produced by any of the foregoing methods.

[0077] Supported embodiments include an apparatus, a system, and/or means for implementing any of the foregoing methods or portions thereof.

[0078] Supported embodiments include any products produced by the foregoing methods.

[0079] Supported embodiments can provide various attendant and/or technical advantages in terms of improved efficiency and/or savings with respect to washers that can be made through powder metallurgy processes to reduce or to eliminate waste material.

Supported embodiments include washers that can be made with metal powders that include a substantial amount of recycled material.

[0080] The detailed description provided above in connection with the appended drawings is intended as a description of examples and is not intended to represent the only forms in which the present examples can be constructed or utilized.

[0081] It is to be understood that the configurations and/or approaches described herein are exemplary in nature, and that the described embodiments, implementations and/or examples are not to be considered in a limiting sense, because numerous variations are possible. The specific processes or methods described herein can represent one or more of any number of processing strategies. As such, various operations illustrated and/or described can be performed in the sequence illustrated and/or described, in other sequences, in parallel, or omitted. Likewise, the order of the above-described processes can be changed.

[0082] Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are presented as example forms of implementing the claims.