JPS6360241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally comprises a multi-piece fastener, and more particularly, a multi-piece fastener comprising a pin and an upsetting collar that exerts a tensile force on the pin and a reaction force on the collar to cause the collar to engage the pin. The present invention relates to a multi-piece fastening device of the type designed to be installed by a tension tool.

A conventional tension-type two-piece fastener includes a pin and a collar adapted to be seated over the pin. The pin has an elongated shank with a head at one end, a plurality of locking grooves and a plurality of tension grooves defined by generally uniform diameter peaks alternating with generally uniform diameter valleys. These tension grooves are provided in the separable pin tail portion of the shank. The pin is inserted into the prepared opening in the workpieces to be joined, and the collar is subsequently applied to the shank of the pin. An installation tool having a jaw assembly is applied to the pin, wherein a tension force can be applied to the pin by adapting the installation tool's jaws having a plurality of teeth to engage the selected number of tension grooves. . The installation tool also includes an upsetting anvil that engages the collar in reaction to the pulling force and upsets the collar into engagement with a locking groove in the shank of the pin. ing. As the magnitude of the pulling force continues to increase, the pin tail portion of the shank separates at the breakneck portion of the pin shank between the locking groove and the tension groove. Discard the pin tail and complete the installation work. However, this pin tail portion is a cost factor for the fastener that contributes nothing to the tightened joint since it only serves to assist in the installation of the fastener.

These pin tails typically have a substantially greater number of tension grooves than are necessary to properly install the fastener. One of the reasons why this excessive number of tension grooves is required, i.e., the excessive length of the pin tail, is to ensure that a sufficient number of tension grooves are engaged with the jaws of the installation tool to install the fastener. This is to ensure that the necessary tensile force is obtained. Engaging an insufficient number of tension grooves with a jaw will cause the engaged tension grooves to wear out before completing the installation of the fastener, thus removing the partially installed fastener. New fasteners will need to be installed.

The cost of this material attributable to this long pin tail may not be significant enough to cause much concern if such tension-type fasteners are made of inexpensive materials, but if the fasteners are This is not necessarily true if the material is made of a more expensive metal, such as titanium, which is commonly used in the industry. In the latter case, reducing to an absolute minimum the amount of material required and therefore the costs associated with the fastening, and in particular reducing the amount and associated costs of that material which does not contribute to the strength of the fastener installed. Thus, it is highly desirable to reduce disposable pin tails. However, 1
One problem is that a minimum number of grooves must be engaged with the jaws of the tool to ensure that wear is eliminated.

Accordingly, it is an object of the present invention to provide a multi-piece fastening device that minimizes the amount of disposable pin tail material. In a preferred form of the invention, the required minimum length of the tension grooves is only as many as necessary to provide sufficient strength to take the installation forces exerted by the installation tool when all grooves are engaged. The pin tail portion of the pin is reduced and formed. In a different form of the invention, the pin tail portion is eliminated altogether and the tension groove is provided within an axially inwardly extending opening in the pin portion of the fastener. In both of these embodiments, the tension grooves are designed to cooperate with the installation tool's jaws to eliminate engagement with less than the minimum number of tension grooves required before tension is generated. This eliminates the possibility of the grooves being worn away.

Thus, the present invention provides a multi-piece fastening device that can substantially reduce or eliminate the length of the pin tail and eliminate the possibility of wearing out the fastener. Reducing the length of the pin tail or eliminating it entirely provides cost savings benefits that are important when using expensive materials.

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

The drawings, especially Figures 1 to 3, generally contain 10
1 shows a tension-type two-piece fastener according to the present invention shown in FIG. The fastener includes a pin 12 inserted into aligned respective openings 14 and 16 of workpieces 18 and 20, and an upsetting collar 22 assembled to the pin.

The pin 12 has a shank portion 24 with a head 26 at one end, and a pin tail portion 2 at the other end.
8 and a plurality of locking grooves 30 arranged between them.
There is. The shank portion 24 between the locking groove 30 and the pin tail portion 28 also includes a break neck groove 32.
is provided. It should be noted that the head 26 of the pin 12 can be of the shear or tension type, and can also be of the protruding type as shown, or of the recessed type if desired. The locking groove 30 may also be of any suitable construction, such as of the type illustrated and described in US Pat. No. 3,915,053. Similarly, collar 22 may be of any suitable type desired.

The pin tail portion 28 of the pin 12 is generally conical in shape and includes a plurality of tension grooves 34 therealong. The tension grooves 34 are each defined by successive alternating peaks 36-42 and valleys 44-50. As shown, breakneck groove 3
Continuous peaks 36 to 4 progressing outward from 2
2 each have a smaller diameter than any of the preceding peaks. Similarly, each valley 44-50 has a diameter that is smaller than the diameter of any preceding valley.

A portion of installation tool assembly 52 is shown in FIGS. 1-3. The assembly 52 includes an anvil 54 having a hole 56 extending inwardly from an end 58;
A collet assembly 60 extends through the bore 56, but generally extends outwardly beyond the end 58. A collet assembly carrier member 62 is reciprocally disposed within an enlarged diameter hole 64 provided in anvil 54, with hole 56 opening therethrough. The outer end of the bore 56 is provided with an outwardly flared, generally frustoconical surface portion 96.

Collet assembly 60 includes a tubular collection jaw structure 67 terminating in a longitudinally segmented jaw section 68 having a plurality of radially inwardly extending teeth 70. The Jyo structure 67 has a longitudinally extending center hole 7 extending inwardly.
There are 2. The joe portion 68 has three joe sections that are resiliently located in a normally open position. Collet assembly 60 has a spring-loaded ejector pin or mandrel 74 that is movably disposed within bore 72 and is pushed outwardly between teeth 70 of jaw portion 68 by a biasing spring 78. is being energized. A flange portion 76 is provided at the inner end of the ejection pin 74, and one surface 77 of the flange portion 76 is provided with a pressure spring 78.
The opposite surface 79 engages an annular shoulder 81 provided within the jaw structure 67 to retain the ejection pin 74 . Pressing spring 78
The other end is seated in a retaining ring 80 that is seated within a groove 82 in the inner end of the collection structure 67.

As previously mentioned, the jaw portion 68 is comprised of a plurality of resilient fingers or sections that have a plurality of axially inwardly extending slits extending only a portion of the length of the collect jaw structure 67. It can be formed by providing 83. Alternatively, the fingers can be provided by making the collection structure 67 from a plurality of separately machined sections. In any event, the outer surface of the collector portion 68 includes an anvil assembly 54.
A sloped or frustoconical surface portion 84 is provided which is engageable with the surface 66 of the. The working mechanism portion of the installation tool 52 may be of any suitable conventional construction, such as the type shown in U.S. Pat. No. 3,329,000. As will be appreciated, when an operator uses the fastener 10
The tool 52 is activated in a tension stroke in which the tool is installed, and then released to activate the tool 52 in a return stroke.

As seen in FIG. 2, when the installation tool 52 is applied to the fastener 10, the distal surface 8 of the pin tail 28
6 engages the rounded end 88 of the ejection pin 74, thereby causing the ejection pin 74 to extend longitudinally into the hole 72.
to compress spring 78. after that,
Tool 52 is applied in its tensioning stroke to move collet carrier member 62 longitudinally relative to anvil assembly 54. As the jaw portion 68 moves longitudinally or axially inwardly relative to the anvil assembly 54, the surface 66 engages the ramped surface 84 and forces the separate fingers of the collector jaw portion 68 radially inwardly. and moving the teeth 70 into engagement with the tension grooves 34 of the pin tail portion 24. When the jaw portion 68 is in the fully closed position, the outer surface 89 engages the side wall 56 of the bore along its length axially outwardly away from the ramp 84 and transfers the tensile force to the pin 12. 2. Holds the fingers of the jaw portion 68 closed when applied.

Thereafter, continued relative movement between the anvil 54 and the collet carrier 62 causes the surface 66 and the portion of the hole 56 thereof to engage the upsetting collar 22 and the upsetting collar 22 to lock into the locking groove 30 of the pin 12. engage with. After that, the tensile force is increased and the pin tail portion 24
In addition, the breakneck groove 32 is ruptured to separate the pin tail portion 28 from the installed fastener. Hole 5
6 is of sufficient length to ensure complete engagement with surface 89 over the entire length of travel of collet assembly 60. The operator then releases the installation tool 52 from its tension stroke, thereby actuating the installation tool 52 into its return stroke, which causes the collet assembly 60 to move axially outward relative to the anvil assembly 54. The tool 52 is then returned to its ready position shown in FIG. At the same time, in the return stroke, the upsetting anvil 5
4 is retracted from the upset collar 22. The jaw portion 68 is then moved radially outwardly to the open position and the separated pin tail portion 28 is ejected therefrom by outward movement of the ejection pin 74. The installation tool 52 is then prepared for application to the next fastener to be installed.

As previously mentioned and best seen in FIGS. 4 and 5, the jaw teeth 70 are located on the pin tail portion 2.
8 peaks 36 to 42 and alternating valleys 44 to 5
It is desirable to have a ring that is complementary to zero and is defined by peaks 90-96 and alternating valleys 98-104. The diameter “A” of the pin tail portion 28 measured at the valley 44 is approximately equal to or somewhat greater than the diameter “B” of the pin tail portion 28 measured at the crest 38. Similarly, valley 4
The diameter of each of the pin tail portions 28, measured at 6 and 48, is approximately equal to or somewhat greater than the diameter of the crests 40 and 42, respectively. Similarly, it is desirable that the jaw teeth 70 of the collet assembly 60 have a shape that complements the shape of the pin tail portion 28 so that the diameter of the aperture defined by and measured by the valley 100 is such that the jaw teeth 70 of the collet assembly 60 are completely shall be smaller than or equal to the diameter of the opening defined and measured by its crest 90 when in the closed position. Similarly, the diameter of each aperture defined by and measured by valleys 102 and 104 is less than or approximately equal to the diameter of each aperture defined by and measured by crests 92 and 94, respectively. Thus, proper and complete application of the installation tool 52 to the pin tail portion 28 will result in full interlocking of the jaw teeth 70 with the tension grooves 34. In this structure, the top of Jiyo 90 in the closed position
The diameter of the peak 90 of the pin tail is larger than the diameter of each of the peaks 38, 40, and 42 of the pin tail. The same is true for Jiyo crest 92 relative to pin tail crests 40 and 42 and Jiyo crest 94 relative to pin tail crest 42.
This also applies to the case of Thus, Jiyo's peak 9 only occurs when both sets of peaks are properly aligned.
0,92,94 are pin tail peaks 36,38,4
0, thereby ensuring that all crests of the pin tail are gripped by all crests of the jaw, or not at all. Thus, for some reason, the operator may not be able to fully or completely apply the installation tool 52 to the pin tail section 28 prior to tool action, and the jyo section may fail to properly axially position the pin tail section. When 68 is closed, the teeth 70 of the jaw and the tension groove 30 do not mesh with each other, so that the tool circulates through the tension groove 34 without wearing it down. This is called idle motion. This state is
The result of incorrect alignment can be seen in Figure 5. Thus, when the jaw portion 68 is in the fully closed position, the opening defined by the crests 90 opens to the axially outwardly disposed crests 38, 4.
0 or 42, but the same is true for Jiyo crest 92 compared to pin tail crests 40 and 42, and for Jiyo crest 94 compared to pin tail crest 42. Thus, according to the invention, if the tool is positioned such that the jaw teeth 70 are in incomplete engagement with all of the tension grooves 34, the collar 12
Since no tightening is performed, the length of the pin tail can be reduced to a minimum without worrying about wear of the tension groove.

Although the invention has been illustrated and described with respect to a pin having a pin tail portion with four tension grooves 34, the particular number is not critical. However, it is possible to provide several tension grooves, each having a shear area such that the sum of the shear areas of the tension grooves that engage the installation tool can support the tensile force necessary to fully install the fastener. It's important. Note that in order to optimize material usage and minimize the amount of material required, the effective total shear area is selected to be a preselected minimum magnitude. Ideally, the minimum effective shear area will be sufficient to undergo the maximum shear stress imposed by the maximum expected load. However, this minimum shear area is set larger than its ideal value to accommodate manufacturing, dimensional, and material tolerances. By providing the above structure with a minimum number of tension grooves having the minimum required total effective shear area, the length of the pin tail portion 28 can be reduced to a minimum. This is a length approximately equal to the nominal diameter of the smooth shank portion of pin 12.

Further, each of the peaks 36 to 42 of the pin tail portion 28 and each of the peaks 90 to 96 of Jiyo has a sufficient radius of curvature at the top, so that, for example, the peak 36 of the pin tail portion and the peak 90 of Jiyo have a radius of curvature. It should also be noted that activating the tool 52 when positioned in the direction cams the tool 52 to assist it in fully engaging or disengaging all tension grooves 34. No.
This arrangement reduces the possibility that the jaw portion 68 will be damaged or destroyed if the crests 36 and 90 are so aligned when the tool 52 is applied.

Additionally, although the present invention is illustrated as including a pin 12 provided with a break neck groove 32, in some applications the pin tail portion may be attached to the pin member 12 without the break neck. You can also leave it as is.

Note that the diameter of hole 56 represents the final swaged diameter of collar 22. This, of course, limits the maximum diameter of the surface 89 of the jaw portion 68. At the same time, the wall thickness of the jaw portion 68 is limited by the hoops of the teeth 70. By using a generally conical shape in the area of the tooth 70 in accordance with the pin tail portion 28, the wall thickness of the jaw portion 68 increases across the valley 104, thereby providing a uniform diameter of the pin tail portion 28.
The strength is increased compared to the case where the teeth 70 are provided. Thus, an additional advantage of the conical shape is that
This is because the strength of the jaw portion 68 is increased.

Although the present invention has been illustrated and described with respect to a fastener having a pin tail portion of minimum length, the pin tail portion may be omitted entirely in some cases. To this end, different forms of the invention are illustrated and described with reference to FIG. Fastener 10 shown in FIG.
5 is a shank portion 1 with a head 110 at one end;
08 including pin 106. pin 106,
Workpieces 116 and 118 are shown loaded into prepared openings 112 and 114, respectively, with pins 106 having upsetting collars 12.
0 is included. In the shank part 108,
A plurality of annular locking grooves 12 on the outer periphery near the end 124
2 is provided, into which a collar 120 is installed during installation of the fastener.

The pin 106 is provided with an aperture extending axially inwardly from its end 124 with crests 130, 132, 134 and alternating valleys 13.
A plurality of tension grooves 128 are provided, defined by 6, 138, 140.

Tension tool 142 includes an anvil portion 144 having an axially extending hole 146 .
6 opens outwardly through end 148 and has a generally frustoconical surface 150 immediately adjacent thereto. Collet assembly 152 includes a mandrel 153 movably disposed within bore 146 .
3 has a forwardly expandable nose portion 154 that has lobes that match those of the tension grooves 128 and has a number of toothed outer surfaces that are engageable with these grooves. Nasal portion 154 is comprised of a plurality of axially extending fingers or sections and has an axially extending hole 156 therein in which is disposed an expansion pin 158 that extends through hole 1.
56 to move the axial extension of nose portion 154 radially outwardly.

Thus, to install the fastener 105, the nose portion 154 is inserted into the opening in the end 124 of the pin 106. At this time, the fingers or sections of nose portion 154 move radially inward to permit insertion as described above. Thereafter, tool 142 is applied to move pin 158 axially into hole 156;
This causes the axially extending section of the nose portion 154 to expand radially into engagement with the tension groove 128, thus causing the installation tool 142 to exert a tension force on the pin 106 and relative movement of the anvil portion 144 into the collar. 120 can be swaged to engage locking groove 122.

The particular number of tension grooves 128 provided within the end 124 of the pin 106 is selected to ensure a total shear area sufficient to resist the forces required to install the fastener. All peaks 130 to 13
4 with corresponding teeth of nose portion 154, the relative diameters of the alternating crests 130-134 and valleys 136-140 and the corresponding valleys and crests of nose portion 154 are as shown in FIGS. 1-5. As shown in the figure, the size and shape are such that it has the characteristics of "entering" and "not entering" with the above-mentioned idle operation. This allows fewer than all tension grooves to be provided in the nose section 154 of the installation tool.
The possibility of engagement is eliminated and the likelihood of wear is also reduced.

Thus, the present invention provides a tension-type fastener in which the length of the pin tail can be substantially reduced to the minimum length necessary to receive the tensile forces required to install the fastener. In a different form of the invention,
The pin tail is completely removed. By reducing the length of the pin tail, significant cost savings can be achieved without any reduction in strength or ease of installation, especially in fasteners made of metals such as titanium.
Additionally, the tension groove and associated jaw portion of the installation tool are designed to effectively reduce the likelihood that the tension groove will become susceptible to wear due to improper positioning or premature action of the installation tool.

In this way, the multiple-piece tightening device of the present invention can remove unnecessary parts that do not affect tightening from the pin tail end, and also can perform the tightening work reliably and smoothly due to the idle operation. This has the advantage of reducing the cost of pin materials.

[Brief explanation of the drawing]

The drawings show an embodiment of a multi-piece fastening device according to the invention, in which FIG. 2 is a view similar to FIG. 1, but showing the installation tool in initial engagement with the fastener; FIG. Figure 3 is similar to Figure 1, but shows the fastener in an installed state with the pin tail part separated from the fastener, and Figure 4 shows the state of engagement between the mounting tool and the pin tail part. 5 is an enlarged partial cross-sectional view of the pin tail of the fastener shown in FIGS. 1 to 3, and FIG. 5 is a similar view to FIG. FIG. 6 is a view similar to FIG. 2, but illustrating an alternative form of the invention, illustrating the incorrect relationship between the tail portions. 12,106... Pin, 22,120... Collar, 30,122... Lock groove, 34,128...
Tension groove, 52, 142...Mounting tool, 54, 14
4...Anvil, 60,152...Collection assembly,
68... Jiyo part, 70... Teeth.

Claims (1)

[Scope of Claims] 1. A tension-type clamping device for attaching a plurality of workpieces to each other, comprising: a pin having an elongated shank portion and a head provided at one end of the shank portion; a locking groove;
When installing the tightening device, the locking groove is swaged into the collar for locking engagement;
a plurality of tension grooves provided in the shank portion; these tension grooves engage the jaws of the installation tool to set the tightening device by a tension force applied through the tension grooves; In a tension-type tightening device defined by alternating peaks and valleys, the diameter of the peaks is equal to the diameter of the head 2.
6; meshing with the corresponding teeth 70 of the jaws 67 of the installation tool in a manner increasing 42-36 or decreasing 134-130 as one advances from the end of the shank portion opposite 106 to said head; A tension-type clamping device characterized in that, by a tight engagement, a substantially precise gripping engagement of the jaws of the installation tool and the tension groove of the pin is made before tensioning of the pin is carried out. 2. The tensioning groove of claim 1, wherein the tensioning groove 128 has a maximum diameter section 134 within an opening extending from the opposite end of the shank portion and adjacent the opposite end. Mold clamping device. 3. The shank portion includes a pin tail portion 28 at an end opposite the head, and the locking groove is provided between the head portion of the shank and the pin tail portion, and the locking groove is provided between the plurality of tension grooves. 2. A tension-type tightening device according to claim 1, wherein said pin tail portion has its smallest diameter portion adjacent said opposite end. 4. A break neck groove 32 is provided between the shank portion and the position of the pin tail portion, and the installation tool is configured to separate the pin tail portion from the shank portion when installation of the tightening device is completed. A tension-type tightening device according to claim 3, characterized in: 5. The tension type tightening device according to claim 3 or 4, wherein the pin tail portion has a length approximately equal to the nominal diameter of the pin. 6 Elongated shank part and 1 of this shank part
An installation tool for installing a tightening device having a pin having a head at an end, the installation tool having a plurality of tension grooves in the anvil and in the shank portion. a collet assembly provided with a jaw, the installation tool applying tension to the pin to displace the anvil into engagement with the collet assembly, and the installation tool applies a tension force to the pin to displace the anvil and engage the collet assembly. The jaws of the installation tool have a plurality of teeth that engage the plurality of tension grooves, and the jaws are in an open position. an attachment tool actuated from to a closed position, in one position the tension groove grips and in the other position releases the tension groove, the teeth being defined by alternating crests and valleys; At the summit 96-
90 is provided inside the jaw so that its diameter continuously decreases in a direction away from the front end of the jacket, or the diameter continuously increases in a direction away from the front end of the jacket. Peaks 42-36; 134-13 are provided on the outside of the jaw and correspond to the outer tension groove and the inner tension groove of the shank portion of the installation tool.
1. A tightening device installation tool, characterized in that the tool engages with 0, respectively. 7. The tension groove has crests and valleys similar in shape to the crests and valleys of the teeth at one position, and the crests of the teeth each engage beyond one of the crests of the tension groove, and 7. The tightening device installation tool of claim 6, wherein the tool has a diameter sufficient to jump over each successive crest when the jaw is then in said one position. 8 The anvil 54 has a central hole for seating the collar onto the pin and the teeth of the jaw are defined by a plurality of sections 68 in guiding engagement with the central hole 56. 8. The tightening device installation tool according to claim 7, wherein the tightening device installation tool is adapted to be moved to a certain position. 9. Claim 8, wherein said jaw comprises a portion having teeth extending beyond the center hole of the anvil when in said other position.
Tightening device installation tool as described in section.