JPH0320106A - Hogring fastener, tool and method - Google Patents

Abstract

PURPOSE: To prevent any interference between hog ring fastener legs relatively inexpensively by arranging them at such an offset angle as is enough to stagger their ends when they are looped and to position them after the looping nearer to each other in the crossing region. CONSTITUTION: A generally U-shaped hog ring fastener 22 comprises a base 24 and a pair of legs 26 each having an end 28. The legs 26 are parallel to each other in respective planes perpendicular to the base 24, but offset to each other at such an angle as permits the ends 28 to cross freely while the fastener 22 is deformed. The offset angle is set small enough to permit the legs 26 to touch or pass each other in a crossing region 32 when the fastener 22 is formed into a final ring 34. The legs 26 are thus free of interference despite of their easy manufacture.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to hog ring fasteners, improvements in fastener assemblies, methods of manufacturing hog ring fasteners and fastener assemblies, and tools for applying hog ring fasteners.
Regarding the method. [Description of the Prior Art] Hog Ring Fasteners Deformable metal fasteners, called hog rings, are used in a variety of applications to form rings around various types of workpieces. For example, in the furniture industry, hog rings are used to attach furniture materials to wire or rod supports. One known hog ring fastener consists of a single piece of wire formed into a curved C-shape with pointed, converging legs.
The fastener is deformed by the tool during application, causing the legs to approach and intersect, forming a loop around the workpiece. Known hog ring fasteners are often assembled in strips or sticks and delivered to the tool one at a time from a magazine. U.S. Patent No. 2.055,
No. 257 and No. 2,678,443 disclose examples of C-shaped hog ring fasteners.

Hog ring fasteners are designed with a structure or shape that prevents opposing legs from abutting and interfering with each other when the hog ring fastener is transformed into a hoop or ring. Interference is undesirable because it prevents the fastener from forming into the desired ring shape and causes jamming and wear and damage of the fastener application tool. The most popular method for preventing interference between the legs of a hog link is to offset the tips of the opposing legs or to chamfer them in opposite directions. An example is found on page 3, lines 32-44 of US Pat. No. 2,174,152. Another known method is to provide an offset to the legs of a C-shaped fastener. Leg or tip offsets are described in U.S. Pat. No. 2,678,443, column 3, pages 29 to 32, and in FIG. A tool with oppositely beveled tips and an offset of the legs during application is disclosed in U.S. Pat. No. 2,921,31.
It is disclosed in No. 5. A stable is a U-shaped preformed wire fastener with parallel legs each perpendicular to the base or curve. Automated manufacturing and packaging equipment has been developed to economically produce and assemble stables. Despite their cost advantages, stables have never been used as often as hog ring fasteners. One reason for this is that inwardly sloping legs are preferred over parallel legs for fastener applications. Furthermore, staples are most economical if they are tipped by chamfering along a plane perpendicular to the plane in which the base and legs are located. This type of tip is called an rCJ tip,
No offset is provided to prevent interference between the legs when forming the ring. A stable with an offset tip chamfered in the cross-sectional direction is also available.
Known as DJ tips, this requires more expensive manufacturing methods.

To employ some of the advantages of stable manufacturing techniques, shaped wire hog ring fasteners with straight bases and legs have been provided. A hog ring having this shape is disclosed in US Pat. No. 2,921,315. As with conventional staples, the legs and base all lie in a common flat plane. Unlike traditional stables, the legs are not perpendicular to the base, but rather
Trapezoidally inclined towards each other. This shape precludes the use of automated packaging and handling equipment used with stables. In order to prevent interference between the legs when the hog ring fastener is formed into a ring shape, the legs are made of relatively expensive r
Equipped with a DJ tip.

Known hog ring fasteners are made by forming wire into the desired shape. Because C-shaped fasteners are expensive to form, many hog ring fasteners are
Currently, it is of the almost trapezoidal type described above. These fasteners can be made with equipment and methods similar to those used in the manufacture of certain staples. However, manufacturing costs are high due to the need to slope the legs of the fastener toward each other as well as the need for oppositely oriented beveled surfaces at the ends of the legs that feature oppositely oriented rDJ tips. "DJ tips cannot be manufactured economically even with the most efficient multi-wire fabrication equipment. Many stable fasteners are made using multi-wire methods; This is an economical and efficient method of producing staples with a "C" tip defined by a chamfered surface perpendicular to the fastener plane. ．． This type of tip is formed by cutting the material from a flat row of adhesive wire prior to shaping. This material is rectangular, and the legs are formed by bending the material and making corners perpendicular to the sides. This manufacturing method has not been used to make hog ring fasteners because it does not allow for offsets in the tips or legs of the fastener.

The known hog ring application tool includes a magazine from which the hog rings are introduced one at a time into a pair of application jaws. These jaws hold the hog ring while being advanced towards the nose of the tool, but do not deform it when the jaws reach the end of their travel path.
Pushed together by a mechanical link system, the hog rings are deformed into a ring shape in one deformation step. An example of this type of tool is U.S. Pat. No. 2,174,152;
It is disclosed in the same No. 2,678,443. U.S. Pat. No. 2,055,257 discloses a hog ring application tool of this type in which the tool jaws are arranged to offset and bend the legs of the fastener into an overlapping condition.

From column 1, line 29 of U.S. Pat. No. 2,921,315, reference is made to a proposal for continuous deformation of the C-shaped hog ring during advancement of the jaws towards the nose of the tool. , this cannot produce a satisfactory effect. The resulting objective of this proposal is to hold the fastener firmly in the jaws. This proposal is unacceptable because the full width of the leg spacing is not maintained.

SUMMARY OF THE INVENTION The main object of the present invention is to provide the legs in parallel planes to enjoy the advantages of existing stable manufacturing and handling equipment while avoiding interference problems between the legs when formed in a ring. An object of the present invention is to provide an improved hog ring fastener having parts. Another object is to provide a hog ring fastener that uses an inexpensive rCJ tip, as well as an assembly of hog ring fasteners and a method of manufacturing the assembly on multi-wire manufacturing equipment. Still another object of the invention is an improved tool for applying a hog ring fastener having legs in a horizontal plane and for attaching the fastener to a workpiece with the legs inclined towards each other;
The purpose is to provide a method. Briefly, the object and advantage of one aspect of the present invention is to provide a wire having a straight base a, a central portion, and a pair of ends forming legs at opposite ends of the base. This is accomplished by providing some hog ring fasteners. The legs lie in separate planes parallel to each other and at right angles to the base. According to the invention, the legs are angularly offset from each other. According to another aspect of the invention, the hog ring fastener assembly is a glued stick of similar hog ring fasteners, each generally U-shaped and having a base and a pair of legs. The base is located in the first plane and the legs are located in the second plane.
, located on the third plane. These second and third planes are parallel to each other and perpendicular to the first plane. According to the invention, the legs in the second plane are angularly offset from the legs in the third plane.

The present invention also provides a method of manufacturing a hog ring fastener assembly by advancing a number of wires in parallel side-by-side in rows along a flat plane and gluing the wires together. The material is cut from the end of this row. Each blank consists of a number of side-by-side wire sections of equal length extending parallel to each other in a first direction. The material is 2
It is folded along two heel lines to form a U-shaped hog ring fastener stick. According to the method of the present invention, in the cutting step, the wire is cut along a cutting Ifr line that is inclined at a certain bias angle with respect to a normal line perpendicular to the first direction. The bend line is parallel to this cutting line. Another aspect of the invention relates to a method of applying a generally U-shaped hog ring fastener having a base and two legs parallel to each other and in a plane perpendicular to the base. The method includes the steps of aligning the fastener with the fastener application area and performing an initial deformation of the fastener after this alignment step to tilt the legs toward each other while leaving a gap between the ends of the legs. Include. The fastener is advanced into the application area after the initial deformation step, and the gap is maintained during this advancement step. A second deformation step is performed in the application area to deform the fastener into a ring shape. Briefly, a hog ring application tool according to the present invention includes a jaw set having a pair of normally open pivoted shows. The jaw set can be moved from a rest position to a fastener application area in a single drive stroke, and the jaws can be moved toward each other during the closing movement. Means are provided for introducing hog rings into these jaws.

A linkage means is connected between the drive means and the jaw set to move the jaw set in a drive stroke. A stop means stops the jaw set in the fastener application area at the end of the drive stroke. The linkage means includes means for closing the show and deforming the hog ring into a ring in response to stopping the jaw set. The linkage means engages cam means which pre-deforms the hog ring by forcing the jaws to partially close only during the first part of the drive stroke, and which drives the hog ring while preventing further closing of the jaws. The jaw set can be moved further during the stroke. The invention, together with these and other objects and advantages, may be best understood from the following detailed description of an embodiment of the invention, which is illustrated in the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, FIGS. 1 and 2 illustrate generally at 20 an assembly consisting of a series of similar fasteners 22 constructed in accordance with the principles of the present invention. As seen in FIGS. 3 and 4, each fastener 22 is a piece of wire generally U-shaped and has a base 24 and a pair of legs 26, each having an end 28.
It includes. Fastener 22 is a type of fastener used to form a ring or hoop around a workpiece and is known as a hog ring. Figures 3-6 show how the fastener deforms into an annular or ring shape during application. The initial form of a single-piece fastener 22 is shown in FIG. In this first configuration, the legs 26 are parallel to each other and the base 2
4 lies in a plane that is perpendicular to 4. During implementation of the fastener application method according to the invention, the fastener is partially deformed or predeformed in a first deformation step, as can be seen in FIG. In this first stage, the base 24 is connected to the central castle 30.
It is partially bent, curved, or arched at the point. As a result, the legs 26 are slightly inclined towards each other. This inward angle facilitates proper engagement of the fastener 22 with the workpiece.

Following the first deformation step, a second or final deformation step occurs, the result of which is shown in FIG. Region 30 is further deformed by bending, curving, and warping. The legs 26 intersect and overlap each other at the crossing regions 32. The deformed base 24 containing the castle 30 and the inner portion of the legs 26 form a ring 34.

As the fastener 22 deforms to create the loop 34, it is important to prevent the ends 28 of the legs 26 from abutting and interfering with each other. According to the invention, interference of the ends 28 is avoided by the angular offset between the legs 26 shown in FIG. leg 26
are not parallel to each other while they lie in parallel planes. Instead, each leg 26 extends from the base 24 at a slightly different angle. The offset angle between the legs 26 is large enough to allow the end 28 of each leg 26 to move freely across another leg during deformation of the fastener 22. Also, the offset angle is small enough that the legs 26 will touch or cross each other at the intersection area 32 when the hoop 34 is formed. If the gap or spacing between the legs 26 at the intersection area 22 is too large, certain workpieces, such as fine wire, fabric fines, etc., may escape from the hoop 34. The optimum value for the offset angle depends on the dimensions of the fastener 22 and the wire from which it is made. A currently preferred offset angle range is from about 2 degrees to about 10 degrees, and a currently preferred offset angle is about 5 degrees. One aspect of the invention is a fastener 22 and a fastener assembly 2.
This is a method to create 0. This method is shown schematically in FIG. 7 and partially in FIG. Preferably, a conventional multi-wire staple manufacturing process is modified in accordance with the principles of the present invention to produce the fastener assembly 20. In this method, a number of individual wires 36 are supplied from a source (not shown) in flat, flat, side-by-side rows. The rows of wires 36 are moved through an application station 38 where an adhesive or bonding agent (usually in liquid form) is applied to the rows. The adhesive or bonding agent is then allowed to dry or harden. A drying or curing station 40 is provided for drying or curing the adhesive by applying heat, air, etc. Depending on the material used, air drying can be used. At this point in the manufacturing process, each wire 36 is glued to an adjacent wire 36 to form a flat, planar web or strip. A cutting station containing a cutting blade or cutting tool 42,44 cuts the material 4 from the end of the wire 36 to which it is glued.
Cut out 6. Unlike the traditional method of cutting the wire along a line perpendicular to its length, the tools 42, 44
is placed at a bias angle (FIG. 8) offset from the normal. The side edges of the blank 46 are defined by and coincide with the direction or length of the wire 36. The edges of the blanks are parallel to each other and are angularly offset from a line perpendicular to the side edges by a bias angle of 48 minutes. In traditional multi-wire methods, rectangular blanks are cut at a cutting station. In the method of the present invention, the material is a non-rectangular parallelogram, and opposing corners are alternately defined by 48 plus and minus bias angles of 90 degrees. The blank 48 is conveyed to a forming station that includes cooperating shaping tools 50, 52. These forming tools are closed over the material to form the material into a fastener assembly 2o. In this shaping operation, a corner 54 of the assembly is created where the leg 26
is deformed so that it protrudes from the base 24. After this forming operation, all legs 26 have the same length and are parallel to each other. All legs 26 on one side of assembly 20 lie in a first flat plane, all legs on the opposite side of assembly 2o lie in a second flat plane, and all bases 24 lie in a second flat plane. Located on a flat plane of 3. The first and second planes are parallel to each other wS1, and the second plane is parallel to the third plane.
perpendicular to the plane. The corners 54 are somewhat rounded or gradually varying, and the first. Construct right-angled corners between the third plane and between the second and third planes. In traditional multi-wire manufacturing methods, shaping tools are positioned to form corners such that the corners lie along lines perpendicular to the direction of the individual wires. Conversely, according to the present invention, as shown in FIG. It will be placed. The edges of the tool are parallel to the front and back edges of the blank 46 and the assembly 20
, the corners 54 are parallel to the fastener ends 28 and the legs 26 are all the same length. Unlike conventional fastener assemblies made by known multi-wire manufacturing techniques, assembly 20 does not occupy a rectangular cylindrical volume.
Instead, the ends of the assembly are eighty. It can be tilted or moved to one side by an angle of 48 degrees. The angular offset between the side edges of the blank 46 and the forming tools 50, 52 causes the legs 26 to
extend from the base 24 at different angles to provide individual fasteners 22 with offset angles as shown in FIG. A[1] The solid body 20 is approximately groove-shaped with a long axis extending along its length. Each leg 26 and each base 24 are inclined with respect to this longitudinal axis. Fastener 22 and assembly 20 have important advantages not achieved by known hog ring fasteners. One of these advantages is that it can be made economically on modified conventional multi-wire staple manufacturing equipment. Additionally, assembly 20 can be handled and packaged at low cost by existing machinery for other fasteners. Because the planes of the legs 26 of the assemblies 20 are parallel, the assemblies can be nested together into a dense and efficient packing row.

Another important advantage is that the wire 36 is cut away by the tools 42, 44.
This means that when the fastener 22 is pinched and cut, a tip is provided at the end 28 of the fastener 22. Many known hog ring fasteners with parallel or symmetrical legs use opposing rDJ tips to prevent interference between the legs when the fastener is formed into a hoop or ring. In this known construction, the ends of the opposite legs of one fastener are defined by planes parallel to the fastener base and inclined in opposite directions. This rDJ
The tip cannot be shaped using a simple cutting tool using the multi-wire method. In practical terms, the "D" tip must be made in a more expensive manner than cutting and shaping one wire at a time with a cutting tool.

The tips of the fasteners 22 are of a different type known as rCJ tips and extend the length of the blank 46 from the leading edge to the trailing edge, and thus have two tips extending the length of the formed assembly 20. It is composed of intersecting inclined planes. The inclined surface is located in a plane that is not parallel to the fastener base 24. Alternatively, if one of the cutting tools 42 or 44 is dull, the tip may be configured by a single plane along either the interior or exterior of the fastener leg 26. When using any of the alternative rCJ tips, shaping the tip at end 28 is easily and economically accomplished by the improved multi-wire manufacturing method according to the present invention by simply cutting off the end of wire 36. ．． 9 and 10, there is shown generally at 60 a hog ring application tool constructed in accordance with the invention. A housing 62 includes a handle portion 64 and a head portion 66 which surrounds a pneumatically actuated drive piston 68 which is normally located in the illustrated park or rest position. When the user depresses the trigger 70, pressurized air flows from the inlet fitting 72 behind the piston 68, actuating the tool 60 to release one hog ring.
A driving stroke for application of the fastener 22 is performed. A track member 7 is mounted on the front cover 75 of the housing 62.
4 is supported, and this track member is connected to the fastener 22.
Fastener application area 7 where is applied to the workpiece (not shown)
It extends forward towards 6. A showset 78 is supported on the track member 74 for reciprocating movement between a normal standby or rest position M (Figs. 9-1l) and a fastener application position at the end of the drive stroke (Fig. 13). ing.
A linkage system 84 connected to drive rod 86 between drive piston 68 and jawset 78 acts to advance the jawset and close jaws 80,82. Fastener 22 is attached to track member 7 by bracket 90.
The fastener assemblies 20 are fed one at a time from a magazine 88 mounted on the front of the fastener assembly 20. Magazine 88 is of conventional construction and includes spring loaded bushers 9l. This pusher forces the fastener 22 upwardly so that it is pinched and gripped by the jaw set 78 as the forwardmost fastener 22 is driven from its standby position. As seen in FIG. 10, the lower surfaces of jaws 80, 82 are offset and angled to match the angularly offset orientation of fasteners 22 of assembly 20. The jaws grip the fastener 22 in the area of the corner 54, but are at a different height relative to the track member 74 to properly engage the fastener. This angled or offset fastener position is maintained throughout the drive stroke. The jaws 80, 82 are formed at the forward ends of a pair of jaw levers 92, 94 which are pivotally mounted intermediate therebetween to a downwardly projecting pin of a reciprocating shuttle block 96. This block 96 includes a downwardly projecting runner 98 that moves in a track (not shown) on track member 74 to a forward stop defined by surface l00 and to a forward stop on track member 74. It slides between a rear stop position provided by screw 102 securing the shuttle block. Linkage system 84 includes jaw levers 92, 94
includes two links 104, 106 pivotally connected to the rear end of the . The rear ends of links 104, 106 are pivotally connected together to a drive joint lO8 attached to the front end of drive rod 86. According to one feature of the invention, during the drive stroke the fastener 22 is deformed in two separate deformation stages. The first stage is
As can be seen in Figures 2 and 5, this occurs in the first WIA movement portion where the fastener is pre-deformed. Here, the legs are tilted inward leaving a gap. This shape is ideal for applying the fastener to the workpiece and remains without further deformation as the fastener is advanced through the remaining drive stroke and into the fastener application area. A pair of cam members 110, 112 are provided on track member 74, one for each path of runner 98. During the first portion of the drive stroke, these cam members contact cam follower surfaces 114 on links 104,106. The cam follower surface 114 is connected to a relief surface 116 provided on the underside of the links 104, 106, and
The preliminary deformation operation in step 2 is limited to a short portion of the drive stroke. Tool 6
0 includes a nose portion 11B with a pair of guide fingers 120 extending into the fastener application region 76. These fingers 120 are useful for gathering, positioning, and holding the workpiece, or for positioning the tool 60 relative to the workpiece. In operation, tool 60 is initially in a standby or rest position with drive piston 68 retracted as shown in FIG. The assembly 20 of the fastener 22 is in the magazine 8
8, the rearmost fastener 22 is pushed by the pusher 9l toward the drive position (FIG. 10) and aligns with the jaws 80,82. Pressurized air is pipe joint 7
2 into the housing 62. Actuation of trigger 70 to initiate a fastener application operation causes piston 68, drive rod 86 and drive coupling 10 to
8 moves forward and begins the drive stroke. Linkage system 84 pushes jawset 78 forward, which in turn pushes shuttle block 96 forward. At the beginning of the drive stroke, the jig g-80,82 cuts one fastener 22 from the assembly 20 supported by the magazine 88. Because links 104.106 tend to spread,
Jaws 80, 82 are moved to the closed position. However, the closing force is overcome by the mechanical resistance to deformation of the fastener 22 and acts to firmly grip the fastener 22 without deformation. Early in the first part of the drive stroke, links l04, 106
cam follower surfaces 114 engage cam abutments 110, 112. As a result, links 104, 106 are pushed from the position of FIG. 11 to the position of FIG. 12. Thus, the jaws 80,82 are forced together into a partially closed position. This partial closure results in a first fastener deformation stage in which the fastener 22 is predeformed and the legs are tilted inward toward the preferred fastener application position. The @1 deformation stage ends when the cam follower 114 passes through the abutments 110, 112 and enters the relief area created by the provision of the relief surface 116 by the abutments 110, 112. When this occurs, the abutment 110
, 112 to link 104.106,
Closing of jaws 80, 82 and deformation of fastener 22 is interrupted. As the drive stroke continues, the gap between the fastener legs is maintained as the jawset 78 advances into the fastener application area 76. When jawset 78 and shuttle block 96 reach the end of their drive stroke, launch 98 engages stop surface 100 and stops, as shown in FIG. Drive piston 6
8. Drive rod 86 and drive joint 108 continue to move forward. As a result, links 104, 106 are pivoted further apart, forcing the show into a closed position. The fastener 22 is deformed into a ring shape around the workpiece in the area between the guide fingers 120. Following the drive stroke, the pressure behind the drive piston 68 is released and the tool is returned to its parked position, ready to apply the next fastener. Although the invention has been described with respect to the embodiments illustrated in the drawings, it is not intended that the scope of the invention be limited in detail as defined in the claims.

[Brief explanation of drawings]

FIG. 1 is a side view of a fastener assembly according to the present invention. FIG. 2 is a bottom view of the fastener assembly of FIG. 1. FIG. 3 is a front view of one of the fasteners in the assembly taken from line 3--3 of FIG. 1 in a plane parallel to the base of the fastener; Figure 4 shows the gIl of the fastener along line 4-4 in Figure 3.
This is a front view. FIG. 5 is a view similar to FIG. 3, showing the fastener in a first deformation stage in the fastener application method according to the invention. FIG. 6 is a view similar to FIG. 5, showing the fastener in the final deformation stage of the fastener application method according to the invention. FIG. 7 is a schematic diagram illustrating steps in a method of manufacturing the fastener assembly of FIGS. 1 and 2 in accordance with the present invention. FIG. 8 is a fragmentary top view illustrating a portion of a method of manufacturing a fastener assembly. FIG. 9 is a side view of a hog ring application tool having the features of the present invention. Figure 10 is a front view of the tool shown in Figure 9. FIG. 11 is a fragmentary top view of the tool of FIG. 9, illustrating the beginning of the hog ring application drive stroke. FIG. 12 is a diagram similar to FIG. 11, and shows an intermediate portion of the hog ring application drive stroke. Figure 13 is the 11th
, is a diagram similar to Figure 12, and is a diagram showing the results of the hog ring application drive process. In the drawings, 20... fastener assembly. 22-... Fastener, 24... Base, 26
... Leg, 3 4-... Ring, 36... Wire, 38-
...Coating station, 4o...Drying or curing station, 42.44...Cutting tool, 46...
・Material, 4 8-... Bias angle, 50.52... Shaping tool. 54--Corner corner, 60--Hog ring application tool, 62--Housing jig, 64--Handle part,
66... Head portion, 6 B-... Drive piston, 7
0... trigger, 74-} rack member, 75... front cover, 76... fastener application area, 78... one jaw set, 80, 82... jaw, 84... linkage system, 8 6-... Drive rod, 88... Magazine, 9l... Pusher, 92.94-... Jaw lever 96... Shuttle block, 104, 1
06... Link, 110, 112... Cam member. 1
20...Guide finger

Claims (8)

[Claims] (1) A hog ring fastener of a type that deforms into a ring shape to surround a workpiece, and includes an integral main body including a base disposed in a substantially U-shape and two legs; the legs are arranged along a straight line joined by right-angled corners, and each leg is arranged at an offset angle from each other, the offset angle causing the ends of the legs to be aligned when deformed into a ring. The offset angle is large enough to cause the legs to move offset from each other, and the offset angle is small enough to position the legs adjacent to each other in the intersection area after the legs are deformed into an annular shape. Hogling fasteners. (2) The hog ring fastener of claim 1, wherein the offset angle is between 2 degrees and 10 degrees. (3) The hog ring fastener of claim 2, wherein the offset angle is about 5 degrees. 4. The hog ring fastener of claim 1, wherein the leg has a tip defined by an inclined surface located in a plane non-parallel to the base. 5. The hog ring fastener of claim 4, wherein said leg has an end having a "C" tip. 6. The hog ring fastener of claim 1, wherein said right-angled corner includes a rounded transition joining said leg to an opposite end of said base. (7) A hog ring fastener according to claim 1, characterized in that said integral body portion is made of wire having a uniform cross section throughout, and said leg portions are of the same length. - Fastener. 8. The hog ring fastener assembly of claim 1, wherein the fastener has sides adhered to each other, wherein all of the bases are in a first plane and all of the legs are in a first plane. 2. An assembly located in a third plane, the second and third planes being parallel to each other and perpendicular to the first plane.