US3218701A

US3218701A - Riveting means and method

Info

Publication number: US3218701A
Application number: US229650A
Authority: US
Inventors: Douglas G Downes
Original assignee: Judson L Thomson Manufacturing Co
Current assignee: Judson L Thomson Manufacturing Co
Priority date: 1962-10-10
Filing date: 1962-10-10
Publication date: 1965-11-23
Anticipated expiration: 1982-11-23

Description

Nov. 23, 1965 D. G. DOWNES 3,218,701

RIVETING MEANS AND METHOD Filed Oct. 10, 1962.

44 INVENTOR.

DOUGLAS DOWNES MQWW ATTORN EYS United States Patent 3,218,701 RIVETING MEANS AND METHOD Douglas G. Downes, Natick, Mass, assignor to Judson L. Thomson Manufacturing Company, Waltham, Mass., a corporation of Massachusetts Filed Get. 10, 1962, Ser. No. 229,650 12 Claims. (Cl. 29-464) The present invention relates to clinching rivets and more particularly to an improved jig and methods of forming and employing the jig. The jig of this invention is particularly useful for positioning a multiplicity of elements to be clinched together in a rivet clinching machine as well as for clinching rivets on a single element.

It is often desirable to rivet together a plurality of preformed elements having preformed rivet holes. Normally the preformed parts are hand assembled and clinched in conventional riveting machines. The operator normally places a rivet in a conventional hand riveting machine with the head down and the shank of the rivet extending upwardly. The operator then slides the rivet hole in each piece to be riveted, over the shank of the rivet and activates a hand riveting machine, such as an arbor press, to bring a hammer into engagement with and peen over the free uppermost end of the rivet while the rivet head is supported by an anvil. As the operator places each workpiece on the rivet care must be taken to align each hole with the rivet shank. This method is extremely time consuming and limits production rates since the machine can work no faster than the hand assembly process which is greatly slowed down by the alignment step. It is particularly time consuming where the workpieces being riveted together must rotate with respect to one another, as no self aligning projection can be formed on the workpieces in such cases.

In another method, costly dies of various types are used to position the workpieces to be clinched together in preselected positions in the riveting machine. These dies must be specially formed for each configuration of each workpiece to be clinched together. In many cases, the configurations of the parts are irregular or highly complex adding further to the cost of forming dies. Due to the high cost involved in this method, the previously described hand assembly method is employed for riveting such workpieces except in those cases where large numbers of similar parts or sets of parts are to be clinched together.

It is an important object of this invention to provide a jig for use on a rivet clinching machine for accurately and efiiciently positioning a multiplicity of elements to be clinched together in a method which may be easily automated.

It is another important object of this invention to provide a jig for use on a rivet clinching machine for accurately and efiiciently positioning a single element allowing a rivet to be clinched to the element.

It is another important object of this invention to provide a method of forming jigs in accordance with the preceding objects which are extremely inexpensive, utilize scrap materials and can be carried out in a minimum of time using a minimum of mechanical skill.

It is still another object of this invention to provide a method of clinching together and positioning a multiplicity of elements in a conventional riveting machine using an inexpensive jig in accordance with preceding objects, which method is easily automated and allows mass production at high manufacturing rates.

It is a still further object of this invention to provide a method of clinching a rivet through a hole in a single element using an inexpensive jig formed in accordance with the preceding objects.

'ice

According to the invention, a jig is preferably formed by die cutting from a member one of the elements of a multiplicity of elements to be clinched together. This results in the member being formed with a blank having a cutout conforming with the outline of the element. The element is then replaced in the cutout. A hole for a rivet shank is preferably die cut into the element at the same time that it is cut out of the blank. The blank is provided with holes so that it may be pinned or otherwise secured after further processing to the rivet machine to support the workpieces being processed between the hammer and anvil. The cutout is then further shaped and cut so that other elements to be joined to the first element may be projected through the cutout.

In use, the jig is relocated in the preselected position on the riveting machine and the second element or a plurality of elements is inserted through the cutout portion and about an upstanding conventional pilot of a riveting machine. The first element is then reinserted into the cutout portion with the bore of the first and second element coaxially aligned. A rivet is positioned with its head or head uppermost and coaxially aligned with the bores. A hammer is then actuated to clinch the rivet with the elements between the hammer and the anvil. This method minimizes the time required for clinching the rivet and assembling the parts as well as drastically reduces the cost of the jig since the member may be a scrap piece from which the first element has been out. In addition, the method is well suited to automation since positive positioning of the elements is easily accomplished. Positive positioning is extremely important when clinching shoulder rivets to plural elements which rotate about said rivet.

In an alternate embodiment of the invention a rivet may be clinched to a single element employing a jig made from a scrap member.

These and other objects and advantages of the present invention will be more clearly understood when considered in connection with the accompanying drawings is which:

FIG. 1 is a cross-sectional view showing a completed clinched rivet assembly of this invention;

FIG. 2 is an exploded view of two elements and a rivet therefor;

FIG. 3 is a top plan view of a scrap member of this invention having a cutout;

FIGS. 4 and 5 are top plan views of the member of FIG. 3 showing further processing thereof;

FIG. 6 is a cross-sectional view through an assembly tcl)1 be riveted showing portions of a known riveting mac me;

FIG. 7 is a side View partially in cross section of a single riveted element; and

FIG. 8 is a cross-sectional view through a rivet assembly showing portions of a known riveting machine.

FIG. 9 is a fragmentary perspective view of a dowel pin useful in this invention.

With reference now to the drawings and particularly FIGS. 1 and 2, a rivet assembly 10 i shown assembled and clinched in accordance with the method of this invention. The rivet assembly 10 preferably comprises a rivet 4 having a flat head 5, a shoulder 6, shank 7 and a clinched end 8. The particular type of rivet employed may vary considerably, for example, beaded rivets, straight shank rivets and flat ended solid rivets may be used if desired. However, the invention is particularly useful for securing rivets having shoulders as illustrated.

A first element 2 is joined to a second element 3 in facing adjacent planar alignment. In the illustrated embodiment, the clinched end 8 actually bites into the second element 3 preventing rotation of the rivet in relation to the second element 3 but allowing rotation of the first element 2 with respect to the rivet and second element 3. In alternate embodiments of the invention, the clinching force may be increased or straight shank rivets may be employed so as to prevent rotational movement of the elements if desired.

The first element 2 preferably has a planar configuration having a curved outline with a rivet shoulder receiving bore 9 extending perpendicular to the plane of the element. The element 2 may have any outer configuration according to its particular desired usage and may, as in the illustrated embodiment of the invention, comprise a linkage or conductive member arm which has a wave outline. The linkage arm 2 is cut preferably by die cutting or stamping it from a fiat or planar member 20, thereby simultaneously forming the member 20 with a blank having a cutout 21 which conforms closely with the outline of the element. Any procedure which utilizes a die to cut the element from sheet stock may be employed in this invention and considered to be included in the term die cutting. The second element 3 may have varying outer configurations but is preferably formed in the same manner as the first element and in the illustrated embodiment is a planar linkage bracket 3 which has a bore 11 of slightly smaller diameter than the bore 9 and is adapted to receive the shank portion of the rivet 4. Both the first element 2 and the second element 3 may vary considerably in thickness size, outline and number of rivet bores provided. The bracket 3' may have an outer outline covering a larger area than the end portion of the linkage arm 2 which carries the bore 9.

The particular materials employed for the member 20, first element 2 and second element 3 may vary. Any materials capable of being stamped or cut from sheet stock may be used. For example, the elements may be composed of plastics, such as nylon, polyethylene, styrene or metals such as steel, tin, copper, etc.

In prior art procedures the member 20 from which the first element 2 is cut is normally discarded or considered to be scrap. However, in this invention the member 20, which is normally scrap, is useful in forming the inexpensive and highly accurate jig of the present invention.

The jig is formed by firstrepositioning the first element 2 within the corresponding cutout 21 of a scrap member 20. In some cases the element 2 may be only partially cut from the member 20 and allowed to remain in the cutout portion until later processing of the jig. Any first element cut by the same die used in forming the cutout 21 may be repositioned in the scrap member 20. As used in connection with positioning in the cutout 21 the term first element may in this application be any first element cut by the same or an identical die as the cutout. As shown in FIG. 4 the bore 9 of the first element 2, While located in the cutout21 is then positioned directly above a pilot of a conventional riveting machine and their respective axes are coaligned. This may be done preferably, by replacing the pilot of the machine with a dowel pin such as partially shown in FIG. 9, having an outer diameter only slightly smaller than the diameter of bore 9. The member 20 is then pushed downwardly against the pressure of bellows 32 until the top of the dowel pin projects through or into bore 9 and thereby coaligns the respective axes of the bore 9 and dowel pin. Because these elements have substantially the same diameters there is a greater degree of accuracy than would be the case if the pilot were used since the pilot of necessity must have a much smaller diameter than the bore so as to accommodate the thickness of the rivet shank. Locating holes 23 which preferably are provided in the scrap member 20 previous to the prior positioning or at anytime after the scrap member is located in the riveting machine are then located on the riveting machine by suitable means or marking for subsequent securing. These holes 23 are used to receive screws or other attachment means for firmly and precisely locking and positioning the scrap member 20 in a conventional riveting machine so that the axis of the pilot is coaxial with the bore 9 when an element 2 is located within the jig.

After correlating the holes 23 of the member 20 with marks on the riveting machine so that the member 20 may be secured to the machine with the pilot of the machine aligned with the axis of bore 9, the member 20 may be removed for the subsequent formations of an additional cutout.

The cutout 25 may be formed by die stamping or other cutting or grinding means after points 22 have been located and marked. Points 22 are marked while the element 2 is in cutout 21 using the center of bore 9 as a reference point. These points 22 are preferably marked when the member 20 carrying element 2 is located in a riveting machine as described in the previous paragraph. Points 22 define the perimeter of cutout 25 and may be shaped to be slightly larger than element 3 but conforming generally in outline thereto but preferably locate a circle having a diameter larger than any width of element 3. As indicated the scrap member 20 preferably is removed from the riveting machine and the cutout 25 made whereupon the scrap member is located and secured to the riveting machine by means of screws passing through holes 23 into the machine.

The jig 29 is shown in its completed form in FIG. 5. A substantial portion of the cutout 21 adjoins the enlarged cutout 25 allowing a first element 2 to be positively positioned by the remaining portion of cutout 21 with the axis of the bore 9 aligned with the axis of pilot 34.

The improved and inexpensive jig of this invention may be used in conventional riveting machines such as riveting machines of the type partially shown in FIG. 6. A support plate 33 is horizontally located by a resilient spring bellows 32. A reciprocally moveable pilot 34 having a narrow diameter portion 39 with a blunted end 40 extends upwardly towards a centrally located hole in the support plate 33. An anvil 50 surrounds the pilot portion 39 and is fixedly mounted within the support plate 33 and is adapted to pe-en the lower end of a rivet as will be described. A reciprocably moveable hammer or plunger and stem 30 is axially aligned with and mounted for reciprocation towards the pilot 34. Support plate 33 has a centrally located recess 31 which forms a locating means for positioning the second element or bracket 3 with its bore 11 coaxially aligned with pilot 34. In some embodiments of the invention the recess 31 is larger than the outline of the second element and simply permits the second element 3 to be recessed so that its top surface is in facing planar relation with a plane drawn through the lower surface of the jig 29 when the jig 29 is positioned in the riveting machine. In these embodiments the position of bore 11 is fixed by placing the element 3 in the riveting machine with the pilot entering bore 11.

The completed jig 29 is preferably firmly attached to the support plate 33 by conventional attaching means such as screws passing through locating holes 23. Alternatively fixed locating pins may be provided in the riveting machine adapted to extend vertically from the support plate and enter holes 23.

In use, the second element or bracket 3 is projected through the enlarged cutout 25 of the jig 29 and into its predetermined position in the recess 31 with the bore 11 surrounding the pilot portion 39. The cutout 25 is large enough to allow passage of bracket 3 therethrough when the bracket and jig are in planar alignment. Subsequently, the first element 2 is reinserted into the cutout portion 21 with an end thereof projecting into the enlarged cutout 25 and with bore 9 coaxially aligned with bore 11 and pilot 34. In this position the elements 2 and 3 are in adjacent facing planar relationship and the pilot end 40 projects about /8 inch above element 2. A conventional rivet feed may be employed to automatically feed a rivet 4 into the position shown in FIG. 6 and the rivet 4 is aligned by the pilot end 40. Subsequently the rivet may be positioned within the bores 9 and 11 by bringing the hammer 30 down to clinch the end 8 between the anvil 50 and hammer 30 as the pilot 34 is reciprocated to a lowermost position (not shown).

It is a feature of this invention that shoulder rivets such as 4 can be positively aligned with a first bore 9 and a second bore 11 using the novel jig 29. In many cases the bore 9 has a radius of as little as 0.0005 inch larger than the diameter of shoulder portion 6. Positive, rapid alignment as by the present invention may be easily and efiiciently accomplished.

In an alternate embodiment of the invention, a single element such as 2 having a preformed bore 9 may have a solid rivet 41 clinched thereon as shown in FIG. 7. In this case the member as shown in FIG. 4 having the single cutout 21 is the completed jig. The jig 20 is located in a riveting machine of the type illustrated generally in FIG. 8 having a resilient bellows 42 supporting a ring shaped horizontal mounting plate 43. A conventional anvil 44 is fixedly located below a central cutout of plate 43 and a reciprocally moveable hammer 45. In some cases the anvil 44 may be reciprocally moveable along a vertical path having an uppermost limit on a plane through the top surface of plate 43.

In the alternate embodiment, the jig 20 with the element 2 positioned in cutout 21 is placed on the surface of plate 43. A locating or dowel pin (not shown) having a diameter slightly smaller than bore 9 and snugly fitting in the bore is then positioned through bore 9 and replaces the anvil 44 in the machine. This step locates bore 9 in its desired position with respect to anvil 44, the axis of the pin and the mechanism which secures it. When the proper alignment is achieved jig 20 is screwed or otherwise fastened to plate 43 through holes 23 and the pin is removed and anvil 44 is replaced. The anvil thereby is coaxial with bore 9. Successive elements 2 can then be positioned in cut-out 21 and riveted by inserting a rivet 41 with its solid shank down into bore 9. The hammer 45 then strikes the rivet head and clinches the free shank end against anvil 44.

It is a feature of this invention that the use of the scrap jig 29 allows positive positioning of elements to be clinched in riveting machines. The cutout portion 21 in the jig is exactly matched to the outline of a portion of element 2 since they are made from the same or an identical die. The clinching procedure may be easily automated by providing conventional feeding apparatus to place the elements in their predetermined positions and remove the assembly from the riveting machine.

A further feature of this machine is that the rivet 4 is placed within the bores 9 and 11 with its head 5 in an uppermost position and the shank 7 extending downwardly. This feature allows the workpieces or elements to be clinched to be positively positioned previous to the positioning of the rivet and facilitates ease of assembly of the parts.

One more feature of the machine is that the jig may be formed of an inexpensive scrap member having a cutout portion formed by an actual die cutout of one of the elements. Any errors in die construction thereby would appear both in the jig and the members thus insuring positive positioning and close fitting of the element 2 in the jig. The jig can be used to successively position identical pairs of elements cut from the same die in the riveting machine.

While there has been shown and described specific embodiments of the present invention, it should be under stood that those skilled in the art may now make many modifications and variations thereof. For example, a plurality of jigs 29 may be employed when more than two elements are to be riveted together. When a third element is used between elements 2 and 3, a second jig 29 having suitable cutout portions as above described partially conforming to the outline of the third element will be located between the support plate 33 and the first jig 29. In this case it is only necessary that all the

cutouts

21 and 25 of the first jig 29, be at least as large as the

cutout portion

21 and 25 of the second jig.

In another modification of the invention, when the second element or bracket 3 is die stamped, the cutout scrap member of the die stamping may be employed and firmly afiixed to the support plate 33 to locate bracket 3 in the riveting machine. In this modification the recess 31 may be eliminated and support plate 33 is substantially planar.

The breadth of this invention is to be construed as limited only by the spirit and scope of the appended claims.

What is claimed is:

1. A method of forming a jig for use on a rivet clinching machine,

said jig being useful for positioning a multiplicity of elements to be clinched together by a rivet, said method comprising die cutting a first one of said elements from a member whereby said member is formed as a blank having a cutout shaped to conform with the outline of said one element,

replacing said one element in said cutout,

locating the position of said member by said one element located in said cutout through which said rivet is to extend, and

further shaping said cutout whereby said other elements may be projected through said cutout. 2. A method of forming a jig for use in a rivet clinching machine,

said jig being useful for positioning a multiplicity of elements to be clinched together by a headed rivet,

cutting a first one of said elements from a member whereby said member is formed into a blank having a cutout shaped to conform with the outline of said one element,

positioning said one element is said cutout,

while said one element is in said cutout locating the position in said one element through which said rivet is to extend to position said member, and further shaping a portion of said cutout whereby at least one other element may be projected through said further shaped cutout portion after said first element is removed from said member and said first element may be replaced in said member in abutting relation with said other element.

3. A method of forming a jig for use on a rivet clinching machine having a coaxially aligned hammer and pilot, said jig being useful for positioning a plurality of elements to be clinched together by a rivet, said means comprising,

said one element having a bore therein adapted to receive a rivet,

locating said one element in said cutout,

locating said member with said element contained therein in a preselected position between said hammer and said pilot with said bore coaxially aligned with said pilot,

further shaping a portion of said cutout in the vicinity of said bore to allow at least one other of said plurality of elements to pass through said cutout when said other element is in planar alignment with said blank.

4. A method in accordance with claim 3 and further comprising the step of afiixing said member in said preselected position to said rivet clinching machine whereby successive elements corresponding in outline to said one element may be successively positioned in said cutout.

5. A method in accordance with claim 3 wherein said member and said element are substantially coplanar.

6. A method in accordance with the method of claim 3 wherein said pilot is replaced by a dowel pin having a diameter adapted to allow said bore to snugly and slideably surround said dowel pin, and

said member with said one element contained therein is located in a preselected position dictated by said bore surrounding said dowel pin. 7. A method of assembling a plurality of elements to be clinched together with a rivet clinching machine, said machine having a horizontally extending support plate with locating means on said support plate for locating a first of said elements adjacent thereto, a pilot extending below and perpendicular to said plate adjacent to means defining an opening in said plate and a jig formed by (1) cutting a second of said elements from a member whereby said member is formed into a blank having a cutout shaped to conform with the outline of said second element, said second element having a bore therein adapted to receive a rivet, (2) locating said second element in said cutout, (3) locating said member with said second element contained therein in a preselected position coaxially aligned with said pilot, (4) further shaping a portion of said cutout in the vicinity of said bore to allow said first element to pass through said cutout when said first element is in planar alignment with said member,

said assembling method comprising positioning said first element adjacent said support plate and located in said locating means, relocating said second element in said cutout overlying and in facing relation with said first element with preformed rivet receiving bores of said first and second elements being axially aligned with each other and with said pilot,

positioning a rivet above said second element with the shank of said rivet extending downwardly from a head of said rivet,

forcing said shank into said first and second element bore and clinching said rivet.

8. A jig useful for assembling and locating a plurality of elements in a rivet clinching machine adapted to clinch said elements together with a rivet, said jig comprising,

a member having a means defining a cutout,

said means defining a cutout having a first portion cut by a die which is the same die used to cut a first element of said plurality of elements and a second portion coextensive with said first portion and larger than a portion of said first element and the outline of a second element of said plurality of elements, whereby said first portion of said means defining a cutout corresponds to a first portion of said first element and said second portion of said means defining a cutout allows passage of said second element therethrough.

9. A jig in accordance with claim 8 wherein said member is substantially planar and positioning means are provided therein for positioning said member in a riveting machine.

10. A method of forming a jig for a riveting maching, said riveting machine comprising a support plate, an anvil and a hammer axially aligned with said anvil, said method comprising,

cutting a first element having a rivet hole therein from a surrounding member whereby a cutout corresponding in outline to said element is formed in said member,

locating said element in said cutout and axially aligning said rivet hole with said anvil and hammer, and afiixing said member to said support plate.

11. A method in accordance with claim 10 wherein said element is riveted in said machine and subsequently removed from said machine whereby successive elements corresponding in outline to said element may be positioned in said cutout and riveted.

12. A reusable jig for use in a riveting machine, comprising a member,

said member having a cutout therein conforming in outline to an outline of a first element to be positioned in said jig,

said cutout being formed by a die used to out said element,

and means on said member for attaching said member to said riveting machine whereby successive elements substantially identical to said first element can be successively positioned in preselected positions in said riveting machine.

References Cited by the Examiner UNITED STATES PATENTS 2,829,488 4/1958 Valli 59-79.5

WILLIAM J. STEPHENSON, Primary Examiner.

Claims

1. A METHOD OF FORMING A JIG FOR USE ON A RIVET CLINCHING MACHINE, SAID JIG BEING USEFUL FOR POSITIONING A MULTIPLICITY OF ELEMENTS TO BE CLINCHED TOGETHER BY A RIVET, SAID METHOD COMPRISING DIE CUTTING A FIRST ONE OF SAID ELEMENTS FROM A MEMBER WHEREBY SAID MEMBER IS FORMED AS A BLANK HAVING A CUTOUT SHAPED TO CONFORM WITH THE OUTLINE OF SAID ONE ELEMENT, REPLACING SAID ONE ELEMENT IN SAID CUTOUT, LOCATING THE POSITION OF SAID MEBER BY SAID ONE ELEMENT LOCATED IN SAID CUTOUT THROUGH WHICH SAID RIVET IS TO EXTEND, AND FURTHER SHAPING SAID CUTOUT WHEREBY SAID OTHER ELEMENTS MAY BE PROJECTED THROUGH SAID CUTOUT.