US3695089A

US3695089A - Electromagnetic riveting machine

Info

Publication number: US3695089A
Application number: US26582A
Authority: US
Inventors: William C Seekins
Original assignee: Hughes Tool Co
Current assignee: Boeing Co; Hughes Tool Co
Priority date: 1970-04-08
Filing date: 1970-04-08
Publication date: 1972-10-03
Anticipated expiration: 1989-10-03

Abstract

An electromagnetic riveting machine comprising a hand-held selectively actuatable electromagnet having means to support a rivet relative to a striker bar positionable on the opposite side of the workpiece from the electromagnet. The striker bar comprises a metal bar pivotally held within a metal frame and biased away from the work surface by a flat spring member acting against the frame. If desired, a permanent magnet may be attached to each of the portions of the tool so as to ensure proper placement thereof relative to one another.

Description

United States Patent Seekins [451 Oct. 3, 1972 [54] ELECTROMAGNETIC RIVETING MACHINE [72] Inventor: William C. Seekins, Los Angeles,

Calif.

[73] Assignee: Hughes Tool Co., Aircraft Division, Culver City, Calif.

[22] Filed: April 8, 1970 [21] Appl. No.2 26,582

[52] US. Cl, ..72/430, 72/445, 72/446, 7 227/ 131 [51] Int. Cl. ..B2lj 15/24 [58] Field of Search....l8/DlG. 33', 72/430, 445, 446, 72/416; 227/131; 29/243.53, 243.54

[56] References Cited UNITED STATES PATENTS 2,752,061 6/1956 Michlein ..227/131 X 2,088,350 'I/l937 Shanks et a1 ..227/l3l Shafi' ..72/416 X 2,313,843 3/ l 943 3,581,373 6/ 1971 Murdoch et a]. ..29/243.54 3,600,928 8/ 1971 Retherford ..'.....72/452 X Primary Examiner-J. Spencer Overholser Assistant Examiner-John E. Roethel Attorney-Smyth, Roston & Pavitt [57] ABSTRACT An electromagnetic riveting machine comprising a hand-held selectively actuatable electromagnet having 5 Claims, 3 Drawing Figures 1 ELECTROMAGNETIC RIVETING MACHINE BACKGROUND OF THE lNVENTlON deformed or upset so that it spreads radially beyond the adjacent hole diameter so that it cannot be removed therefrom.

In prior art devices, rivets have normally been put into position in two ways. In the oldest method, the rivet is positioned in the-aligned holes and a large, heavy bucking bar is positioned against the headed end of the rivet and a pneumatic rivet gun is used to deform the other end of the rivet.

This method is satisfactory in a large number of applications, but depends upon the availability of space for the positioning and holding of the bucking bar. When space is not available, the method cannot be utilized.

The inherent difficulty found in the older method has been solved to a great extent through the use of what has become known as blind rivets. Such rivets are SUMMARY OF THE INVENTION The present invention relates to an electromagnetic riveting machine capable of upsetting standard rivets.

, Further, the machine is capable of upsetting such rivets in otherwise inaccessible places and can be manufactured to be much smaller and lighter than previously available pneumatic riveting guns.

Basically, the machine comprises two elements, one of which is positioned on each side of the structure which is to be riveted. One element consists of a selectively actuatable electromagnet to which a rivet support is attached. The second element comprises a striker bar which is held in a position away from the .structure to be riveted by a spring acting between the bar and a supporting wire frame.

In use, the first element is positioned on one side of a workpiece so that the rivet support holds the headed end of a standard rivet in aligned holes and, in effect,

acts as a bucking bar. The second element is positionedon the opposite side of the workpiece so that a free end of the striker bar is positioned above the end of the rivet which is to be upset. The electrom agnet in the first element is actuated, creating a magnetic field which acts upon the striker bar to draw it toward the electromagnet, and consequently the rivet, against the force of the spring. The weight and mass previously required in pneumatic riveting guns is effectively replaced by the momentum of the striker bar as it impacts the free end of the rivet. Cyclic actuation of the electromagnet causes repetitive upsetting strokes by the striker bar until the rivet is fully upset.

If desired, a permanent magnet may be mounted upon the second element supporting frame to cooperate with either a second permanent magnet or a second electromagnet on the first element so as to be able to position the elements relative to one another in blind areas.

The use of structure embodying the concepts of the present invention allows rivets to be upset very quickly, and allows strong riveting in previously inaccessible areas. Additionally, the riveted structure will be stronger than heretofore possible since the standard rivet provides'greater strength than is available with the well-known, hollow-shanked blind rivet. As an added feature, use of a machine embodying this invention will allow less expensive fabrication of riveted structures which would otherwise be possible with the use of-blind rivets since standard rivets are less expensive than blind rivets.

Other advantages, objects, modes, and embodiments of this invention will become obvious to those skilled in the art through reference to theDetailed Description and accompanying drawing which illustrate what are presently considered to be preferred embodiments of the best mode contemplated for utilizing the novel principles of the invention which is intended to be limited only by the recitation of the claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation of a first embodiment of the electromagnetic riveting machine formed in accordance with the present invention;

FIG. 2 is a perspective illustration of one element of the machine shown in FIG. 1'; and

FIG. 3 is a plan view of an alternate embodiment of a machine formed in accordance with the present invention.

DETAILED DESCRIPTION pivotally supports a striker bar 29 for movement toward and away from the rivet 23. A leaf spring 31 is suitably fixed to the bar 29 by means such as screws or rivets 33. The spring acts against a transverse member of the frame 27 so as to bias the striker bar 29 to the position illustrated in FIGS. 1 and 2.

In use, an operator inserts the rivet 23 into the aligned holes in the workpiece 25 and then positions the electromagnet element so that the rivetsupport 19 holds the head end of the rivet as shown and acts as a bucking bar.

The striker bar element is positioned on the opposite side of the structure to be riveted so that the free end of the bar is positioned over the shank of the rivet. i

The electromagnet 11 is then actuated by the operation of trigger l7, causing a magnetic field to be created which acts upon the striker bar 29 so as to draw it into upsetting contact with the rivet 23 in a very rapid pivoting motion relative to the frame 27.

When trigger 17 is released, the striker bar will return to' the illustrated position due to the influence of spring 31. Repeated operation of trigger 17 will result ina like number of strokes by the striker bar 29 .until the shank of the rivet 23 is fully upset and the next rivet can be put into place.

The embodiment-of the invention illustrated in FIG. 3, has'a great deal of structure which is identical to that found in the previously described embodiment. That structure which is identical has been provided with identical labels preceded by the numeral 1"; electromagnet 11 therefore becomes 111, etc. No further description is'deemed necessary.

As shown, the electromagnet 111 has a rivet support 151 thereon having a recessed portion 153 for the support of the head of a rivet 154 which is not meant to be flush with the surface ofthe adjacent workpiece 125.

A striker bar 155 is pivotally supported on the frame 127 and has an upsetting recess 157 at the free end thereof so as to control the amount of upsetting of the shank of the rivet. In other words, the recess 157 will prevent the shank from being upset to a degree greater than that determined to be necessary when the structure to be riveted is designed.

An auxiliary frame 161 is suitably fastened to the frame 127 or the striker bar 155 so that a permanent magnet 163 is suitably supported relative to the striker bar. a

An arm 165 mounted on the handle 113 supports a magnet 167 which may be either a permanent magnet or may be a second electromagnet which is selectively actuated'either by the trigger 117 or by other suitable means.

Magnets

163 and 167 are suitably positioned, by auxiliary frame 161 and arm 165 so that they cooperate with one another to ensure the proper alignment of the electromagnet and the striker bar elements. Thus, for example, if the electromagnet element is held against the adjacent workpiece 125 and moved in a direction parallel to the surface thereof, the striker bar 155 will be moved in a similar direction and distance since the magnet l63 will tend to follow the magnet 167.

In manufacturing machines utilizing the concepts of the present invention, it will be apparent to those skilled in the art that the electromagnet actuating trigger could be replaced by an automatic triggering mechanism which will produce far more rapid movementof the striker bar. Further, a rheostat could be added to the system so that the strength of the magnetic field generated by the electromagnet could be adjusted was to take into account the characteristics of the workpieces .which are to be riveted. Additionally, the elements could be coated with a suitable substance, such 'as Teflon, to prevent scratching of the surfaces of the workpieces and to aid in dragging the striker bar into position, e. g., when the embodiment shown in FIG. 3 is utilized.

Thus, the applicant has disclosed two embodiments of new and improved concepts in machines which may be utilized in the riveting art and which yield a true advance in tl}at art. Maggdfurther modifi ations and alterations 0 these em iments, as we] as other embodiments, will be obvious to those skilled in the art without exceeding the scope of the invention which is defined in the following claims:

I claim:

1. In a machine for fixing a rivet to structure comprising one or more workpieces with a rivet head on one side of the structure and an upset portion on the other side thereof,

a first element having means for supporting the headed end of the rivet, means for creating an electromagnetic field, and means for activating and deactivating said electromagnetic field and a second element having a supporting frame,

a magnetically attractable striker bar pivotally mounted in said supporting frame, and a biasing means between said supporting frame and said striker bar and biasing said striker bar to a position away from the end of a rivet to be upset. 2. The machine of claim 1 wherein said first element further includes alignment means thereon and said second element further includes I alignment means thereon which cooperate with said first element alignment means to properly align said first and second elements relative to one another and to a rivet to be upset. 3. The machine of claim 2 wherein said first element alignment means and said second element alignment means both comprise magnetic elements suitably aligned to be mutually attractive. 4. The machine of claim 1 wherein said striker bar includes an upsetting surface thereon and means for limiting the upsetting of a rivet by limiting the pivotal travel of said upsetting surface. 5. A riveting machine comprising a first element having means for generating an electromagnetic force field and I means for supporting one end of a rivet relative to workpieces to be fastened together by a rivet and a second element having means, responsive to an electromagnetic force field, for moving toward and upsetting the other end of a rivet supported by said first element and means for biasing said upsetting means away from a rivet supported by said first element, said first and second elements each including a magnetic locating and positioning member thereon for ensuring proper positioning of said first and second elements relative to a rivet to be upset and to one another.

Claims

1. In a machine for fixing a rivet to structure comprising one or more workpieces with a rivet head on one side of the structure and an upset portion on the other side thereof, a first element having means for supporting the headed end of the rivet, means for creating an electromagnetic field, and means for activating and deactivating said electromagnetic field and a second element having a supporting frame, a magnetically attractable striker bar pivotally mounted in said supporting frame, and a biasing means between said supporting frame and said striker bar and biasing said striker bar to a position away from the end of a rivet to be upset.

2. The machine of claim 1 wherein said first element further includes alignment means thereon and said second element further includes alignment means thereon which cooperate with said first element alignMent means to properly align said first and second elements relative to one another and to a rivet to be upset.

3. The machine of claim 2 wherein said first element alignment means and said second element alignment means both comprise magnetic elements suitably aligned to be mutually attractive.

4. The machine of claim 1 wherein said striker bar includes an upsetting surface thereon and means for limiting the upsetting of a rivet by limiting the pivotal travel of said upsetting surface.

5. A riveting machine comprising a first element having means for generating an electromagnetic force field and means for supporting one end of a rivet relative to workpieces to be fastened together by a rivet and a second element having means, responsive to an electromagnetic force field, for moving toward and upsetting the other end of a rivet supported by said first element and means for biasing said upsetting means away from a rivet supported by said first element, said first and second elements each including a magnetic locating and positioning member thereon for ensuring proper positioning of said first and second elements relative to a rivet to be upset and to one another.