A) TECHNICAL FIELD

[0001] The present invention generally relates to a fastener and particularly relates to a rivet like fastener for joining a plurality of surfaces. The present invention more particularly relates to a twin-sided flush fastener with reduced overall dimension for permanently affixing two or more structural members together.

B) BACKGROUND OF THE INVENTION

[0002] Fasteners are the most widely used means to join two or more objects or surfaces together. The fastener provides a mechanical strength to the affixed surfaces for longer periods. There are various types of fasteners available such as rivets, screws, carriage bolts, tapping screws and the like which can be used for different purposes according to the requirements. The fastener may be removable or permanently fixed based on the manufacturing and requirement.

[0003] One of the existing prior art methods provide a method and system for rivet fastener with a round or domed head. The round head fastener is a flush type rivet which is inserted into the apertures of the structural members to be joined. The rivet is then set by punching. Once the fastener is set, the end part of the fastener protrudes out of the finished riveting work. The thin protrusion does not give an aesthetic finished look to the joined structure.

[0004] Another prior art provides a fastener for joining two structural members permanently. The shank diameter of the fastener is greater than 3.0 mm and the head diameter is greater than 5.0 mm. Because of the above dimensions, the fastener is limited to be used only in the aperture diameter greater than 3.0 mm and not in structures having apertures with decreased diameter.

[0005] Hence, there is need to provide a fastener with reduced overall dimension to fit into holes/apertures of smaller diameter. Further, there is a need for a fastener which upon deformation gives an aesthetic look to the joined surfaces with no bulging part.

C) OBJECT OF THE INVENTION

[0006] The primary object of the present invention is to provide a flush fastener with reduced overall dimensions to join a plurality of surfaces having apertures of smaller diameter.

[0007] Another object of the present invention is to provide a flush faster which can be accommodated into apertures of lesser space constraint.

[0008] Yet another object of the present invention is to provide a flush fastener which on flattening flush with both sides of the surfaces to provides an aesthetic clean appearance to the joined surface.

[0009] Yet another object of the present invention is to provide a flush fastener whose length can be controlled based on the thickness of the surfaces to be joined.

[0010] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

D) SUMMARY OF THE INVENTION

[0011] The present invention generally relates to a flush fastener comprising an elongated shank portion and a shank head provided on at least one end of the shank portion. The flush fastener is provided with a dimension to secure a plurality of surfaces having pre-drilled holes of less dimension by creating a mechanical interlock between the plurality of surfaces.

[0012] According to an embodiment of the present invention, the shank portion of the flush fastener is cylindrical in shape adapted to extend through the apertures on the plurality of surfaces. The shank portion is at least one of hollow rivet or a solid rivet.

[0013] According to an embodiment of the present invention, the shank head is deformed to a flat structure such that the deformed shank head fills the pre-drilled holes to affix the plurality of surfaces permanently.

[0014] According to an embodiment of the present invention, a tool having a punch is utilized to deform the shank head of the flush fastener to interlock the plurality of surfaces.

[0015] According to an embodiment of the present invention, the flush fastener is formed of a stainless steel or a mild steel material.

[0016] According to an embodiment of the present invention, the flush fastener is twin-sided for securing a plurality of surfaces having pre-drilled holes aligned with the holes of the other surfaces being countersunk.

[0017] Embodiments of the present invention further provide a method of fastening a plurality of surfaces having pre-drilled holes. The method comprises inserting a flush fastener into the predrilled holes on the plurality of surfaces, verifying a required protrusion of the flush fastener from an opposite end of the insertion, flattening a protruded part of the flush fastener by a punching means. The flattening fills the gap of the aperture and permanently joins the plurality of surfaces together thereby providing an aesthetic appearance from both sides of a riveted object.

[0018] According to an embodiment of the present invention, the pre-drilled holes in each of the plurality of surface are coaxially aligned to form a single cylindrical aperture where the pre-drilled hole is any of a free hole or a countersunk hole.

[0019] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

E) BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

[0021] FIG. 1 illustrates a side perspective view of the flush fastener, according to an embodiment of the present invention.

[0022] FIG. 2 illustrates a front view of the flush fastener, according to an embodiment of the present invention.

[0023] FIG. 3 illustrates the flattened flush fastener, according to an embodiment of the present invention.

[0024] FIG. 4A and 4B illustrates the process of inserting the flush fastener and adjustment of the plurality of surfaces to be affixed, according to an embodiment of the present invention.

[0025] FIG. 5A and 5B illustrates a punching means and process for flattening the shank portion of the flush fastener inserted in the surfaces to be affixed, according to an embodiment of the present invention.

[0026] FIG. 6A and 6B illustrates the permanently affixed surfaces after flattening the flush fastener, according to an embodiment of the present invention.

[0027] Although the specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.

F) DETAILED DESCRIPTION OF THE INVENTION

[0028] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

[0029] The present invention generally relates to a rivet like twin-sided flush fastener for joining two or more surfaces together. The flush fastener comprising an elongated shank portion and a shank head provided on at least one end of the shank portion. The flush fastener is provided with a dimension to secure a plurality of surfaces having pre-drilled holes of less dimension by creating a mechanical interlock between the plurality of surfaces. The end part of the shank is referred to as shank end. The shank end of the flush fastener is deformed or upset to a flat surface by punching or hammering. The deformed or upset shank end fills the hole and affixes the objects to be joined permanently. Here, the flush fastener is formed of a stainless steel or a mild steel material.

[0030] The shank portion of the flush fastener is cylindrical in shape adapted to extend through the apertures on the plurality of surfaces. The shank portion is at least one of hollow rivet or a solid rivet.

[0031] A punch is utilized to deform the shank head of the flush fastener to interlock the plurality of surfaces.

[0032] The method of fastening a plurality of surfaces having pre-drilled holes comprises inserting a flush fastener into the predrilled holes on the plurality of surfaces, verifying a required protrusion of the flush fastener from an opposite end of the insertion, flattening a protruded part of the flush fastener by a punching means. The flattening fills the gap of the aperture and permanently joins the plurality of surfaces together thereby providing an aesthetic appearance from both sides of a riveted object.

[0033] The pre-drilled holes in each of the plurality of surface are coaxially aligned to form a single cylindrical aperture where the pre-drilled hole is any of a free hole or a countersunk hole.

[0034] The sided flush fastener permanently joins two surfaces together. The surfaces include but not limited to metal sheets, electrical appliances, telecommunication products, computers casing, electronic gadgets enclosures and the like.

[0035] The flush fastener is provided with a reduced overall dimension to fit into holes of smaller diameter. The preferred dimensions of the flush fastener of the present invention includes a shank diameter of 1.9 mm, shank head diameter of 3.5 mm and the hole size where the flush fastener is to be inserted is 2.0 mm.

The dimensions of the flush fastener can be varied based on the requirement. The dimensions of the flush fastener which can be varied include but not limited to the diameter of the shank, diameter of the shank head, thickness of shank head, length of the fastener etc.

[0036] The smaller dimension of the flush fastener occupies less space and thus solves the issue of space constraint while joining a plurality of surfaces together.

[0037] FIG. 1 illustrates a side perspective view of the flush fastener, according to an embodiment of the present invention. The flush fastener 100 is the twin-sided flush fastener. The flush fastener 100 comprises an elongated shank portion 102 which is cylindrical in shape with a constant diameter throughout its length. The proximal end of the shank portion 102 is defined to be shank head 101. The shank head 101 is a thick cylindrical shaped structure with a diameter greater than the diameter of the shank portion 102. The distal end of the shank portion 102 is defined as shank end 103. The shank portion 102 is adapted to be inserted into the coaxial holes of a plurality of surfaces to be joined. The shank end 103 is then punched and flattened to affix the plurality of surfaces permanently. Here the fastener shank can be either a hollow structure or solid structure which is made of either stainless steel or mild steel.

[0038] FIG. 2 illustrates a front view of the flush fastener, according to an embodiment of the present invention. The flush fastener 100 is a twin-sided flush fastener, as the fastener can have double sided face such that it avoids the projection on the bottom side once the fastener is fixed which in turn saves spaces. The shank portion 102 of the flush fastener 100 is cylindrical in shape with a uniform diameter 1.9 mm along its length. The shank portion 102 of the flush fastener 104 resembles a rectangular shaped structure when viewed from the front. The shank portion 102 is inserted into the coaxial holes of the surfaces to be affixed. The shank head 101 is the thick cylindrical shaped structure with a diameter of 3.5 mm. the dimensions of the flush fastener 100 is such that it can be inserted into an aperture having a diameter as small as 2 mm. further, based on the requirements, the diameter of the shank portion 102 and the shank head 101 of the fastener 100 can be altered and also the thickness of the shank head 101 can be altered.

[0039] FIG. 3 illustrates a flattened flush fastener, according to an embodiment of the present invention. The flush fastener 100 is the twin-sided flush fastener. The long cylindrical section of the flush fastener 100 is the elongated shank portion 102 with constant diameter. The proximal end of the shank portion 102 is the shank head 101. The shank head 101 is the thick cylindrical shaped head with the constant diameter greater than the diameter of the shank portion 102. The distant end of the shank portion 102 is defined as shank end 101. The shank portion 102 is inserted into the hole, formed by coaxially aligning the holes of the plurality of surfaces. With respect to FIG. 3, the flush fastener 100 is in flattened or in an upset state. The shank end 103 is punched and flattened by a tool having a punching means. After punching the shank end 103 by a punching mean, the flattened shank end 103 deforms to a shape having the diameter more than the original diameter. The punching of the shank end 103 also reduces the length of shank portion 102. The flush fastener 104 affixes the two or more surfaces with a firm and close fitting.

[0040] FIG. 4A and 4B illustrates the process of inserting the flush fastener and adjustment of the surfaces to be affixed, according to an embodiment of the present invention. With respect to FIG. 4A, two surfaces 202 and 203 are selected. The selected surface 202 and 203 comprises a hole/aperture 201 at a desired position. The flush fastener 100 is inserted into holes of predefined diameters (preferably at least 2.0 mm). The hole is either a free hole or a countersunk hole. The surface 202 and 203 are aligned coaxially with respect to the corresponding holes 201. The flush fastener 100 is positioned above one of the holes 201 formed by coaxially aligning the surfaces (202 and 203). The flush fastener 100 is then inserted into the coaxially aligned hole of the surfaces 202 and 203. Before inserting the flush fastener 104 into the coaxially aligned hole, the axial length of the hole is measured and corresponding flush fastener 100 is selected with suitable dimensions. The preferred diameter of the shank portion is 1.9 mm and the hole diameter is 2.0 mm.

[0041] With respect to FIG. 4B, the flush fastener 104 is inserted into the coaxially formed hole. The shank end 103 of the flush fastener 104 protrudes out from the rear/opposite end of the surface 203. The surface 202 is below the surface 203 with the flush fastener 100 ready to be flattened.

[0042] FIG. 5A and 5B illustrates a punching means and process for flattening the shank end of the flush fastener inserted in the surfaces to be affixed, according to one embodiment of the present invention. The flush fastener 100 is designed for joining a plurality of surfaces having pre-defined holes. The pluralities of surfaces are arranged such that the pre-defined holes define a continuous free hole or a countersink hole. The shank portion 102 of the flush fastener 100 conforms into the predefined holes such that the shank end 103 adapted to be flattened projects out of the co-axially aligned holes.

[0043] With respect to FIG. 5A, a solid rectangular punching means 501 is adopted for clearly understanding the fastening process. However, punching tools of different shape and size can be adapted for punching the fasteners to join the surfaces. The punching means 501 is positioned to a specific area over the surface 203, where the flush fastener 104 is protruding out. The FIG. 5B illustrates the flush fastener 100 being punched by the punching means 501. When the punching means 501 applies a force on to the protruded flush fastener 100, the end of the flush fastener 100 is flattened to a different shape. The flattening process is performed over the surface 203. The flattened shank end provides a strong mechanical interlock and affixes the surfaces 202 and 203 permanently.

[0044] FIG. 6A and 6B illustrates the permanently affixed surfaces after flattening the flush fastener, according to an embodiment of the present invention. As shown in FIG. 6A, the final finished product illustrates two surfaces 202 and 203 affixed with the flattened flush fastener 100. When the flush fastener 100 is set, the shank head 101 in the hole is flattened and radially expanded to become substantially flush with the surface 203.

[0045] FIG. 6B is a rear end view of the finished product comprising the surfaces 202 and 203 affixed with the flattened flush fastener 104. The shank portion 102 inserted into the holes and the shank end 103, when punched becomes tightly pressed and creates a continuous surface in pressure relationship with the holes. Thus the holes are filled by the radial expansion of the shaft head 101, shaft portion 102 and the shaft end 103. The flush fastener 100 forms a clean fit in the holes on both sides with no part (shank head and shank end) bulging out of the holes and thus providing an aesthetic appearance.

[0046] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.

G) ADVANTAGES OF THE INVENTION

[0047] The various embodiments of the present invention provide a twin sided flush fastener with reduced overall dimensions.

[0048] The shank end and the shank head of the flattened flush fastener do not bulge out of the finished riveted work.

[0049] The flush fastener provides an aesthetic appearance after flattening the shank end as both the sides flush better with the surfaces.

[0050] The flush fastener even affixes two extreme edges of any surfaces by overcoming the manufacturability issues of others.

[0051] The flush fastener herein is simple in design and durable in construction and can be manufactured by low cost techniques from a variety of easily available materials like steel and other alloys.

[0052] The flush fastener can be employed to affix various surfaces comprising metal sheets, electrical appliances, telecommunication products, computers casing, electronic gadgets enclosures etc.

[0053] The flush fastener provides adequate force to hold the deformed different surfaces together thereby providing an improved seal between the affixed surfaces.

[0054] Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the disclosure with modifications. However, all such modifications are deemed to be within the scope of the
claims.

[0055] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.

CLAIMS

What is claimed is:

1. A flush fastener comprising:

an elongated shank portion; and

a shank head provided on at least one end of the shank portion;

wherein the flush fastener is provided with a dimension to secure a plurality of surfaces having pre-drilled holes of less dimension by creating a mechanical interlock between the plurality of surfaces.

2. The flush fastener of claim 1, wherein the shank portion is cylindrical in shape adapted to extend through the apertures on the plurality of surfaces.

3. The flush fastener of claim 1, wherein the shank portion is at least one of hollow rivet or a solid rivet.

4. The flush fastener of claim 1, wherein the shank head is deformed to a flat structure such that the deformed shank head fills the pre-drilled holes to affix the plurality of surfaces permanently.

5. The flush fastener of claim 1, wherein a tool having a punch is utilized to deform the shank head to interlock the plurality of surfaces.

6. The flush fastener of claim 1, wherein the fastener is formed of a stainless steel material or a mild steel.

7. The flush fastener of claim 1, wherein the fastener is twin-sided for securing a plurality of surfaces having pre-drilled holes aligned with the holes of the other surfaces being countersunk.

8. A method of fastening a plurality of surfaces having pre-drilled holes, the method comprises:

inserting a flush fastener into the predrilled holes on the plurality of surfaces;

verifying a required protrusion of the flush fastener from an opposite end of the insertion; and

flattening a protruded part of the flush fastener by a punching means;

wherein the flattening fills the gap of the aperture and permanently joins the plurality of surfaces together thereby providing an aesthetic appearance from both sides of a riveted object.

9. The method of claim 8, wherein the pre-drilled holes in each of the plurality of surface are coaxially aligned to form a single cylindrical aperture where the pre-drilled hole is any of a free hole or a countersunk hole.