US3111868A - Apparatus for joining refractory brick channels and hangers - Google Patents

Description

Nov. 26, 1963 R. M. FOCHT 3,111,868

APPARATUS FOR JOINING REFRACTORY BRICK CHANNELS AND HANGERS Original Filed Dec. 1, 1959 3 Sheets-Sheet 1 85 55 I 1 ROBERT M. FOCHT ATTORNEY 10 I 6 INVENTOR R. M. FOCHT 3,111,868

APPARATUS FOR JOINING REFRACTORY BRICK CHANNELS AND HANGERS Nov. 26, 1963 Original Filed Dec. 1, 1959 FIG. 5.

INVENTOR ROBERT M. FOO HT BY WW ATTORNEY Nov. 26, 1963 R. M. FOCHT 3,111,868

APPARATUS FOR JOINING REFRACTORY BRICK CHANNELS AND HANGERS Original Filed Dec. 1, 1959 3 SheetsSheet 3 7 FIG.6. u w 7. FIG. 9

' -2 52 l III. A 68 a 5 3| 17/ 69 79 i 40 4a I 24 1 I +45 38 l 84 l 1 11 45 A2 37 as as a1 a; FIG. H. 44 43 7 FIG.7.

37 I 53 INVENIOR ROBERT ItFOCHT FIG. 8. V

ATTORNEY United States Patent 3,111,868 APPARATUS FOR JOHNENG REFRACTORY BRICK CHANNELS AND HANGERS Robert M. Focht, Lansdale, Pa, assignor to E. J. Lavino and Company, Philadelphia, Pa.

Original application Dec. 1, 1959, Ser- No. 856,395, now Patent No. 3,031,748, dated May 1, 1962. Divided and this application July 25, 1960, Ser. No. 45,017

8 Claims. (Cl. 78-46) This invention relates to the art of manufacturing refractory brick and more particularly the manufacture of such brick having embedded therein a reinforcing metal channel and hanger tab.

In the manufacture of refractory brick use is made of metal channel members which are embedded in the body of the brick, where the brick is formed or manufactured for specialized uses, and such channels are also attached to hanger tabs for use in fixing or securing the brick in place.

The insertion of the metal reinforcing channels into the body of the brick or into the brick material as it is being formed or pressed into shape, has heretofore created certain problems which have made it diflicult to produce a brick which is free of certain internal stresses which tend to cause the brick to crack.

This is a divisional application of application Serial No. 856,395, filed December 1, 1959, now Patent No. 3,031,- 748, granted May 1, 1962.

In a copending application filed by Walter J. Thomas, Sr. and myself, a description of the problems involved and the manner in which they develop is given, together with a means by which this problem is solved or overcome. As set forth in the application in question, the metal channels hereto-fore used had solid webs between the sides or legs thereof, and because of this, when the channel is pressed into the brick material, leg iirst, the legs are caused to separate or spread, which sets up stresses in the metal at the angles between the legs and the web which results in the tendency of the legs to pull back toward their original parallel relationship, thus leaving certain voids in the brick material which produce undesirable cracks and weakness in the finished brick. The solution of the problem whereby the metal channel can be introduced into the brick material in the usual manner without setting up the stresses and without resulting in the formation of voids in the brick material, is accomplished by splitting the internal channel web from each end through a portion of its length. Where the metal channel is equipped with the hanger tabs which heretofore have been attached to the channel web, it then became necessary to devise a means whereby the tab could be secured to the web in such a manner as not to interfere with the function of the split of the web. It is accordingly an object of the present invention to provide a novel method of attaching the hanger tab to the web of the reinforcing channel in such a manner that the tab will be so secured to the channel web that when the stresses are applied to the logs of the Web as the channel is being forced into the brick material, the attachment will become loosened, at least on one side of the split of the web, so that the function of the split will not be interfered with or defeated.

A further object of the invention is to provide a method of staking together two pieces of metal in a new and novel manner which will permit the separation of the pieces under certain circumstances resulting from the imposition of a predetermined degree of strain or tension placed upon the connection.

Still another object of the invention is to provide a new and novel type of apparatus whereby the operation of staking the metal parts together in accordance with the present invention may be easily and quickly carried out.

3,11 1,868 9atented Nov. 26, 1963 Broadly the method of the present invention consists in providing one of the two pieces of material with an aperture or a pair of apertures and then locating the aperture over a die point carried by a member set in an anvil with the member having a channel therein around the base of the die point, the die point being of frusto-conical form. The other piece of metal to be staked to the apertured piece is then placed over the aperture and a tapered punch is then forced down against the other piece of metal with suflicient pressure to extrude a portion of the metal of the upper piece into the aperture of the underlying piece of metal and around the die point, forcing the extruded metal into the channel around the base of the die point and laterally against the under surface of the apertured piece of metal so as to form between the two pieces of metal a locking stake or rivet and a locking key which is designed to yield when a sufficient amount of strain is placed upon the coupled pieces of metal.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents, are therefore intended to be embraced by those claims.

In the drawings:

FIG. 1 is a perspective view of a split web metal channel having a hanger tab secured thereto and indicating in broken outline the body of the brick in which the channel is embedded;

PIG. 2 is an exploded View showing an end portion of the split web channel as it appears before the angled tab is afiixed, and the angled tab, and illustrating the apertures in the latter through which portions of the web metal are extruded to form the securing stake;

FIG. 3 is a view in top plan of the apparatus for effecting the securement of the tab to the channel web;

FIG. 4 is a longitudinal section taken substantially on the line 4--4 of FIG. 3, but showing the stripper plate and carrier block separated and in relationship thereof either prior to or immediately following the punching op eration;

FIG. 5 is a longitudinal section taken substantially on the line 55 of FIG. 3, showing the device in a closed position;

FIG. 6 is a transverse section taken on the line 66 of FIG. 3;

FIG. 7 is a bottom plan view of the pressure pad or stripper plate;

FIG. 8 is a top plan view of the die table;

FIG. 9 is a detail sectional view on an enlarged scale through a portion of the anvil and a die member and showing in section the angled portion of the hanger tab and a portion of the channel web with the punch in raised position preparatory to downward movement for extruding the metal of the web;

FIG. 10 is a sectional detm'l on an enlarged scale taken in the plane of section line 66, but illustrating only one die member and an end portion of the punch and showing the formation of the extruded metal stake or rivet;

'FIG. 11 is a sectional detail illustrating on an enlarged scale the completed stake by which the two portions of the channel reinforcement and tab are secured together.

Referring now more particularly to FIGS. 1 and 2, the numeral 10 generally designates a metal channel member of the type used for reinforcing refractory brick, which channel, as here illustrated, is modified in accordance with the invention disclosed and claimed in the hereinbefore referred-to co-pending application to permit the side legs of the channel to spread when the channel is pressed into the refractory brick material in the procedure of manufacturing the brick. The channel member ltl comprises the side leg portions 1?. and the connecting web 14 therebetween. The web 14 is provided at each end with a centrally located longitudinally extending slit 1%. The slits l8 terminate short of the transverse center of the web so that there is a central solid portion of the web which is designated 14 and the web is provided with apertures Ztl each of which spans a slit 1% and which apertures facilitate the positioning of the channel on the hereinafter described table of the die press apparatus.

The slits 18 as formed initially in the web have an edge portion bent inwardly slightly throughout, as indicated at 22. However, the slit at the end of the channel to which the hereinafter described hanger tab is attached, has a portion of the edges thereof from the outer end of the web inwardly brought into the same plane as indicated at 18', as a result of the pressing of the hanger tab to the channel web.

The hanger tab which is attached to the web portion of the channel, is generally designated 24. This hanger member comprises a strip of flat metal having a long part as and a shorter right angularly turned end part 2-8 and the width of this part 2% is less than the distance between the channel legs 12 whereby the angled end part 23 can be placed against the inner face of the web between the legs.

In FIG. 1 the hanger tab is shown in fixed position against the channel web and it is held in this position by the securing stakes hereinafter described and here indicated in FIG. 1 by the reference character Ell.

Referring now to FIG. 2, it will be seen that the angled end portion 28 of the tab has the two apertures 31 therein whereas the web portion of the channel at opposite sides of the portion of the slit which is designated 18', is imperforate.

The body part 26 of the hanger tab has a slot 32 formed therein and the metal tongue which is struck from this body part 26 is turned inwardly and is designated 33. This tongue is pressed into the brick material in the formation of the brick to facilitate or assist in forming a good looking connection between the channel member and the brick material.

The apparatus designed for carrying out the method of pinning or riveting the hanger tab to the web 14 with the angled portion 28 of the hanger tab disposed across a portion of the slit 1%, is illustrated in FIGS. 3 to 8. In these figures the numeral 35 generally designates the apparatus which embodies a head plate 36 and a bottom or base plate 37 which are disposed in spaced superposed relation. The base plate carries a pair of upstanding guide posts 38 which at their upper ends enter guide openings 39 formed in the head plate and pass through guide sleeves 4t? secured to the underside of the head plate 35 as illustrated particularly in FIG. 6.

Mounted upon the top of the base plate 37 is a table supporting block ll. This block is of substantial height and length and is relatively narrow in its cross section as shown most clearly in FIG. 6, and it may be secured in upright position in a suitable manner to the base plate as by the use of screw bolts 42 having the heads 43 thereof counter-sunk in the underside of the base plate, as indicated at :4. The threaded portions of the bolts 42. pass upwardly into the threaded bores 4-5 in the block 41.

The base plate 37 and block 4 1 are also provided with bores to receive dowels 42'.

One end face of the block 41 is cut away to form an inwardly extending recess 46 which receives the tongue portion 3-3 of the hanger tab when the tab and channel member are in position for riveting or staking together, as hereinafter described, and the end face of the block 4-1 above the recess as is grooved or slotted as indicated at 4 7 to facilitate the placement of the hanger tab in position.

For convenience of description the end face in which the recess 46 and slot 57 are formed will be referred to as the front end of the lower die part.

The numeral 48 generally designates an elongate plate which functions and will be described as the table on which the web portion of the metal channel rests in the operation of the apparatus. This table is of a width approximating that of the table block 41 and has a forward end portion 49 which is flush with the front end or front face of the block 41 and across which the slot 47 is extended, as indicated at 50.

The table plate is fixed to the top of the block 41 in a suitable manner, as for example, by the use of Allen screws or bolts 51, which are counter-sunk in the top of the table plate and are threaded into bores in the top of the table block as illustrated. Also the table and support block are provided with bores to receive dowels 51.

The top surface of the table at the forward end thereof is formed with the recess 52. This recess extends across the full width of the table and to the forward end thereof and has a depth approximating the thickness of the angled portion 28 of the hanger tab.

Formed in the forward end of the table in the recessed area 5?; are two apertures 53 into each of which is set a die member 54. These die members are in the form of cylindrical bodies and each has its top surface flush with the surface of the table recess 52 and the center of each die member is formed with the upwardly extending frustoconical point or button 55 which is encircled at its base 'by a channel 56, which extends below the top surface of the die member as best seen in the enlarged sectional details forming FIGS. 9 and 10. This channel is illustrated as being U-shaped and one side of the channel forms a continuation of the side of the frusto-conical point or button.

The forward end of the table plate, that is, the end designated 49 in which the recess 52 is formed, becomes an anvil as will be hereinafter apparent, against which the thrust of the hereinafter described punches is directed. Also it will be seen that the die members are set in the anvil end of the table in a line transversely of the table and spaced equi-distantly from the longitudinal center thereof.

As shown in FIGS. 5 and 8, the table is of substantial length and projects a substantial distance rearwardly from the block 4 1. The top surface of the table is formed throughout the major portion of its length from the back end thereof with a rectangular channel 57. This channel terminates short of the recess 52, at the hereinafter described centering stud. At the forward end of the channel the table plate or body has two longitudinally spaced holes 53 formed therein which, when the table is secured by the screw bolts 51 to the top of the block 41, are aligned with passages 59 extending downwardly through the block 41 and through the base plate 37.

The holes 58 are designed to receive the shank end 6%) of a locating or centering stud 61 which projects above the top surface of the table as shown in FIG. 5 and is employed for locating the metal channel on the table, as will be hereinafter set forth.

Fixed to the underside of the head plate 35 is an elongate punch carrier block which is generally designated 62. This block is held firmly in position against the underside of the head plate by the countersunk machine bolts or screws ss.

As shown most clearly in FIG. 6, the punch carrier block 62 is of a width somewhat greater than the width of the table block 4d and it also extends at its forward end beyond the forward end of the table block 41, as shown in FIG. 5.

The punch carrier block 62 is provided with guide passages or bores 64 which are on the longitudinal center of the block and located one adjacent to each end of the block, and these bores receive dowels 65 fixed to the head plate as illustrated.

The punch carrier block also is formed with a number of spring housing chambers each of which in designated 66. Six of these chambers are here illustrated, there being two which are spaced on the longitudinal center of the block, and four arranged in rectangular relationship at the mid portion of the block, and in each of these chambers there is housed an expansion spring 67. The spring housing chamber 66 opens through the bottom of the block 62 to bear against the top of the hereinafter described pressure pad or stripper plate.

Adjacent to the forward end of the block 62 there are formed the two transversely spaced bores 63 which extend vertically through the block and each of these bores has fixed therein a punch pin 69, which pins are positioned to be axially aligned each with a frusto-conical point or button carried by the underlying die member and the lower end or punch end of each punch pin is tapered as indicated at 7% and terminates in the blunt or flat circular end face 71. The diameter of this end face is approximately that of the bottom of the annular channel 56.

The punch pins 69 are held in position in their respective bores 68 by set screws 72 which are threaded into opposite side faces of the punch carrier block 62.

The numeral 73 generally designates a flat plate forming a pressure pad or stripper plate. This stripper plate is approximately the same width and length as the punch carrier block 62 against the underside of which it is positioned, and it is maintained in connection with the block 62. for limited up an down movement by stripper bolts 7% which, as shown in FIG. 4, are positioned or located for sliding movement in bores 75 formed vertically through the block 62 with the threaded lower end 7a of the bolts secured in and to the plate 73 while the head 77 of the bolt is located for free movement in vertical passages 7:; formed in the head plate 35.

As shown in FIG. 4, the springs 67 bear upon the top of the pressure pad or stripper plate and thus when the head plate is elevated by a suitable means, the block 62 and the stripper plate will separate to a certain extent, the limit of separation being controlled by the difference between the height of the block 62 and the length of the portion of the bolt 74 between the threaded end 76 and the head 77.

The stripper plate 73 is provided with the two transversely spaced vertical openings 79 in proper position to receive the lower ends of the punch pins 69 and the punch pins are adjusted axially so that when the stripper plate is forced away from the block 62 by the springs 67, the tapered ends of the punch pins will be drawn into the openings 79 and when the head plate is forced downwardly and the pressure pad or stripper plate '73 comes to rest upon the web portion of a channel member straddling the table 48, the punches will be projected below the bottom face of the stripper plate 73 to perform the desired punching operation.

Secured across and to the under face of the plate 73 at the forward end thereof is a locating bar 80, the same being fixed in position by a machine bolt 81 and the bar is maintained in proper position transversely of the under face of the stripper plate by dowels 82 which are press fitted or otherwise secured in appropriate openings in the press bar and the stripper plate.

In the operation of the apparatus for performing the method of attaching the hanger tab to the web portion of the metal channel, the head plate is elevated to the proper extent to permit the tab and channel to be placed in position on the table. The angle portion 23 is then placed in position on the anvil surface of the table, such surface being the bottom of the rectangular recess formed in the top of the table, with the die points or buttons 55 located in the apertures 31. As will be seen upon reference to FIG. 5, when the tab is placed in this position, the main portion 26 thereof will be extended downwardly across the front of the table block 41 and the tongue 33 will be extended into the recess 46.

The channel body lid is then placed on the table with the legs in straddling relation thereover, the web portion lying upon the top of the table. The channel is properly located on the table by the engagement of the locating stud 61 in the opening 29 of the web and when the channel is so positioned on the table a portion of the slotted end thereof will be located over the previously placed angled part 28 of the hanger tab.

The channel 57 formed longitudinally in the top surface of the table receives the inturned edge of each of the slots 13, thus permitting the web to lie firmly and flat on the top of the table, and by means of suitable pressing apparatus the head plate is then forced downwardly and the pressure pad will first come to rest upon the top of the channel web and as will be readily obvious, continued pressure will then close the gap between the pressure pad or stripper plate and the underside of the block 62 against the resistance of the springs 67 and the locating bar will act to assure proper relationship of the channel and hanger tab to each other. Thus the punch pins will be projected from the openings 7e against the channel web in line with the openings 31 in the underlying angle portion of the tab 24. The metal of the channel web will thus be forced by the tapered flat end surfaced portions 79 of the punch pins into the openings 33 and will be distributed radially and extruded into the U-channel 56 to spread laterally for a slight distance against the under face of the angled portion 23 of the tab.

Simultaneousiy with this punching and extruding operation the edge portion of that channel is lying over the tab part 28 and the unslotted surface of the table beyond the locating stud 61, will be brought into the same plane, as shown at 18 in FIG. 1.

To permit the desired operation the pressure pad or stripper plate is provided with suitable sockets as indicated at 83 in line with the bores 58 so that the positioning stud 61 secured in one of the bores can project beyond the under face of the stripper plate.

FIG. 11 illustrates on an enlarged scale the details of the stake or rivet thus formed. In this figure it will be seen that the metal of the web has been removed in the area designated 84 and extruded into the opening 31 lying beneath the punch pin to form a stake or rivet 8-5, and the portion of the extruded metal which has been forced into the channel 56 forms an annular locking key 86 so that the two parts, namely, the web portion of the channel and the angle portion 28 of the hanger tab, are thus locked together. However, this locking key is of such character that when the channel member is forced into the refractory brick material in the operation of pressing the brick and the stresses applied to the legs of the channel cause the legs to spread, the locking key will be broken away or displaced sufficiently, at least in one of the openings 32 to permit separation of the edges of the portion 18' of the slit and thus prevent the establishing of stresses in the angle member at the corners between the legs and the web to a degree which would cause the legs to tend to come back to their former positions and form undesirable voids or weak places in the brick after the pressing force on the brick material has been removed.

As will be seen from reference to FIG. 11, the rivet or stake formed in the manner described is hollow, having the downwardly opening pocket or chamber 87. Thus the stake wall nearest to the end to which the annular key 86 is joined is relatively thin and this further facilitates the releasing of the coupling between the channel web and tab under the circumstances above described.

For operating the apparatus hereinabove described, use may be made of any suitable pressing mechanism for forcing the head plate 35 downwardly and elevating it as required. For example, the device may be and has been used in a standard mechanical or hydraulic press of sufficient open height and capacity to accommodate the device. In this connection the base plate 37 is fastened to the bolster of the press, while the head plate 35 is fastened to the reciprocating slide of the press. No illustration of such a mechanism has been made as it is believed that it will be readily obvious how the apparatus may be secured s,111,ses

I? in a standard mechanical or hydraulic press in the manner stated.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined in the appended claims, and all cianges that fall within the metes and bounds of the claims, or that form their functional as well as conjointly cooperative equivalents, are therefore intended to be embraced by those claims.

I claim:

1. Apparatus for eifecting the connecting of a metal channel member having a web portion and a metal tab having an aperture in one end by pressing metal of the channel web into the aperture of the tab; said apparatus comprising a table having a top surface formed to support the channel member with the web portion thereof lying on the table surface, the table at one end having a recess in the surface thereof extending to the end of the table to receive the apertured portion of the tab, the surface of the bottom of the recess forming an anvil, a stationary die member carried by said table and having a portion projecting upwardly from said anvil surface and said upwardly projecting portion having a maximum diameter only slightly less than the predetermined diameter of the tab aperture, a vertically movable structure overlying the anvil, a punch member carried by said structure in alignment with the die member and movable to a working position relative to the die member short of actual contact therewith, and means coacting with the lower end of the said upwardly projecting portion of the die member to receive metal forced by the punch member from the channel web and effect the simultaneous formation of a hollow rivet and the locking together of the channel web and tab in one operation of the punch and further to effect formation of a relatively thin weakened area in the rivet around the end thereof remote from the punch member to facilitate the rupturing of the rivet and separation of said web portion and tab.

2. The invention according to claim 1, with a pin projecting upwardly from the surface of the table in a predetermined spaced relation with tie end of said recess remote from said one end of the table and upon the longitudinal center of the table for engagement by a part of the channel web when the channel is placed on the table to maintain the channel in position relative to the tab.

3. The invention according to claim 1, wherein the die member is in the form of a frustum of a cone and the said means includes a recess at the base of the cone and lying below the anvil surface and extending laterally a. slight distance beyond the base of the cone.

4. The invention according to claim 1, wherein the die member is in the form of a frustum of a cone and the said means includes a U-shaped annular recess encircling the base of the cone with the inner side of the U forming a continuation of the side of the cone.

5. The invention according to claim 1, with a bar member connected to and extending across the underside of said vertically movable structure adjacent to the recessed end of the said table and in a position to move in a vertical path across said end of the stripper plate in the downward movement of the plate in the performance of a punching opera-tion and to maintain the channel and the tab in proper relationship with one another.

6. Apparatus for releasably coupling together an end of a metal channel web and an end part of a flat hanger tab by means of a formed hollow rivet portion of the web secured in an aperture of said part of the hanger tab; said apparatus comprising a table having a top surface for supporting the metal channel to the Web of which the apertured part of a tab is to be fixed, the table surface having a shallow recess therein at one end thereof and the recess extending to and opening through the said one end of the table, the recess being dimensioned to receive the apertured end part of a flat hanger tab and having a depth approximating the thickness of said tab end part, the surface of the bottom of the recess forming an anvil, a stationary die member set in the table and having a top surface coplanar with the anvil surface and the die memher having a central upwardly tapering point projecting above the said top surface and terminating in the plane of the table suriace, said point being dimensioned to have a diameter at its base only slightly greater than the diameter of the aperture in the tabend, a vertically movable structure overlying the anvil, a punch carried by and fixed to said structure in alignment with the die member and movable to a working position relative to the point of the die member short of actual contact therewith, and means at the base of the die member and lying below the said top surface of the die member for receiving metal forced from the channel web and into the aperture of the end part of a tab around the die point by the punch and said means diverting the metal laterally to the under side of the part of the tab lying on the anvil to effect in one operation the formation of a hollow rivet and the locking together of a channel web and the apertured end part of a tab, with said hollow formed rivet having an encircling relatively thin weakened wall portion in the area of the laterally diverted metal of the web for facilitating the rupturing of the rivet for separation of the web and tab joined thereby.

7. The invention according to claim 6 wherein said die point is in the form of a 'r-ust'um of a cone and the said means at the base of the point comprises an annular recess encircling the base of the cone with the inner side of the recess forming a downward continuation of the side of the cone, the recess being U-shaped in cross section.

8. The invention according to claim 6 with a bar member carried by and extending across the under side of said vertically movable structure at the said recessed end of the table and positioned to be moved downwardly by said movable structure to extend across the said one end of the table simultaneously with the operation of the punch to engage a tab member having the angular end part thereof on the anvil and maintain the tab member angular part and the channel web in proper relationship one with the other.

References Cited in the file of this patent UNITED STATES PATENTS 636,916 Mergenthaler Nov. 14, 1899 1,252,289 Murray Ian. 1, 1918 2,348,998 Pease May 16, 1944 2,430,377 Vorreyer Nov. 4, 1947 2,514,659 McOlun-g July 11, 1950 21,713,197 Schmidt July 19, 1955 2,754,877 Gasstrom July 17, 1956 2,870,533 Benham Jan. 27, 1959

Claims (1)

1. APPARATUS FOR EFFECTING THE CONNECTING OF A METAL CHANNEL MEMBER HAVING A WEB PORTION AND A METAL TAB HAVING AN APERTURE IN ONE END BY PRESSING METAL OF THE CHANNEL WEB INTO THE APERTURE OF THE TAB; SAID APPARATUS COMPRISING A TABLE HAVING A TOP SURFACE FORMED TO SUPPORT THE CHANNEL MEMBER WITH THE WEB PORTION THEREOF LYING ON THE TABLE SURFACE, THE TABLE AT ONE END HAVING A RECESS IN THE SURFACE THEREOF EXTENDING TO THE END OF THE TABLE TO RECEIVE THE APERTURED PORTION OF THE TAB, THE SURFACE OF THE BOTTOM OF THE RECESS FORMING AN ANVIL, A STATIONARY DIE MEMBER CARRIED BY SAID TABLE AND HAVING A PORTION PROJECTING UPWARDLY FROM SAID ANVIL SURFACE AND SAID UPWARDLY PROJECTING PORTION HAVING A MAXIMUM DIAMETER ONLY SLIGHTLY LESS THAN THE PREDETERMINED DIAMETER OF THE TAB APERTURE, A VERTICALLY MOVABLE STRUCTURE OVERLYING THE ANVIL, A PUNCH MEMBER CARRIED BY SAID STRUCTURE IN ALIGNMENT WITH THE DIE MEMBER AND MOVABLE TO A WORKING POSITION RELATIVE TO THE DIE MEMBER SHORT OF ACTUAL CONTACT THEREWITH, AND MEANS COACTING WITH THE LOWER END OF THE SAID UPWARDLY PROJECTING PORTION OF THE DIE MEMBER TO RECEIVE METAL FORCED BY THE PUNCH MEMBER FROM THE CHANNEL WEB AND EFFECT THE SIMULTANEOUS FORMATION OF A HOLLOW RIVET AND THE LOCKING TOGETHER OF THE CHANNEL WEB AND TAB IN ONE OPERATION OF THE PUNCH AND FURTHER TO EFFECT FORMATION OF A RELATIVELY THIN WEAKENED AREA IN THE RIVET AROUND THE END THEREOF REMOTE FROM THE PUNCH MEMBER TO FACILITATE THE RUPTURING OF THE RIVET AND SEPARATION OF SAID WEB PORTION AND TAB.

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