US2447589A - Rivet stem puller and cutter - Google Patents

Description

- L. P. MELLERIO ETAL 2,447,359

RIVET STEM FULLER AND CUTTER 2 sheets-sheet 1' Filed June 20, 1944 NNN Aug. 24,1948. P. MELLERIQy ETAL 2,447,589

RIVET STEM FULLER AND CUTTER 2 Sheets-Sheet 2 Filed June 20, 1944 B-czS/P Cooper' Fw. fd A Patented Aug. 24,l 1948 lTED STATES PATENT OFFICE 2,447,589 RIVET STEM FULLER AND CUTTER Application .l une 20, 1944, Serial No. 541,230 lin Great Britain November 23, 1943 7 Claims. l

This invention is concerned with that class of rivet-setting in which a hollow rivet is upset by being expanded by the head of a mandril of which the shank or stem extends through the rivet from a pulling implement engaging the flange end thereof. Since a mandril may be used but once, an object of the invention is to provide an implement that will first do the upsetting and thereafter sever the mandril adjacent to but outside the flange end of the rivet in such a way as to swage the remnant of the mandril remaining in the rivet. The swaging thus produced will retain the remnant in the rivet where it will serve not only to close the throat of the rivet but also to reinforce the shear strength of the assemblage.

A-novel feature of a rivet-setting tool embodying the invention is provided by a combination including one means for upsetting a rivet by pulling a mandril, another means for swaging and severing the mandril between the pulling means and the rivet, and actuating mechanism by which the pulling means and the severing means will be operated successively. As herein illustrated, the actuating mechanism includes a lazy tongs the collapsing movement of which produces the effective movement of the mandril by which its head is pulled into a rivet to do the upsetting. The same lazy tongs carry a striker into engagement with an element of the swaging and severing means which is thereupon actuated by continuing the collapsing movement of the tongs after the upsetting stage is completed. Thus, one collapsing stroke of the tongs rst does the upsetting and thereafter does the swaging and the severing.

Referring to the drawings,

Fig. 1 is a plan View of the illustrative tool with part of a lazy-tongs mechanism, which it embodies, broken away and with a pair of swaging cutters, with which the tool is provided, shown in section;

Fig. 2 is a plan View showing the lazy-tongs mechanism, of which part only is shown in Fig. 1;

Fig. 3 is a sectional view taken on the line III- III of Fig. l;

Fig. 4 is a sectional View taken on the line IV- IV of Fig. 1;

Fig. 5 is a sectional View taken on the line V--V of Fig. 1;

Fig. 6 is a sectional View taken on the line VIv VI of Fig. 1;

Fig. 7 is an elevational View of the two cooperating cutters with which the illustrative tool is provided:

Fig. 7a is a detail sectional view taken on the line VlIa-Vlla of Fig. '7;

Fig. 8 is a detail elevational View of part of the lazy-tongs mechanism seen in Fig. 2;

Fig. 9 is a detail perspective View, partly in section, showing a rivet, with a severed portion of a mandril therein, which has been set by the use of the illustrative tool;

Fig. 10 is a sectional View of the set rivet shown in Fig. 9;

Fig. 11 is a sectional view of the set rivet shown in Figs. 9 and 10, but with the plane of section at right angles to that of Fig. 10; and

Fig. 12 is a sectional view similar to Fig. 10, but showing a set rivet in which the severed end of the portion of the mandril which remains in the rivet does not project outwardly beyond the head of the rivet.

In Figs. 9 to 12 the severed end portion of the mandril is shown conventionalized to a precision of geometric form which .may not always be exactly obtained in the severing of a metal mandril although the result will have equivalent elect.

The illustrative tool comprises a supporting plate I having secured thereto a. handle 3 which will be held in one'hand by the operator when the tool is manipulated. The plate I has projecting therefrom a lug 5 in which is a bore which serves as a guideway in which a rod 'I is slidably mounted. The rod 'I is affixed by screw-threads to a, rectangular block 9 (see Figs. 1, 2 and 4) The block 9 has recesses II at opposite sides thereof and in these recesses are received rolls I3 mounted on pins I5 carried at the bifurcated end portions of two levers Il which are pivoted on pins I9 fixedly mounted in lugs 2l formed on the plate I (see particularly Fig. 6). At their other end portions the levers II have pins 23 xed in them (see particularly Figs.v 1 and 3) which project at each side of the levers. One pin 23 (the uppermost in Fig. 1) is received in slots 25 formed at the end portions of two similar levers 2l. The other pin 23 is received in slots 2S Vformed at the bifurcated end portion of a lever 3|. The lever 3| lies between the levers 21 and all three are connected by a pivot pin 33 (see particularly Fig. 8) which has a large head 35 constituting a striker, the purpose of which will be hereinafter described. The levers 21 and 3| have links 31 pivoted to them at their far ends and the links 31 are pivoted together on a pin 39 carried by a, knob 4I. The levers I1, 21 and 3I and the links 31 form a lazy-tongs mechanism by which the rod l will be moved in one direction lengthwise of aV 3 mandril in consequence of moving the knob 4| in the opposite direction, but the movement of the rod will be relatively short and powerful. The lost-motion connection provided by the pins 23 and slots 25 and 29 enables the levers 21 and 3 to continue their `collapsing movement despite stoppage of the levers v|1.

The rod 1 has an axial bore 43 therein which is just large enough to receive the stem portion of a mandril M. Mandrils used for this work have stems of sufficient ductility to undergo considerable swaging in the process of beingsevered by the cutters hereinafter described. When a mandril has been inserted in the `bore 43 it can be secured therein by a clamp screw 45 threaded in the rod 1 and having an operating handle l|51. The bore 43 in the rod connects z with another bore 49 of larger diameter. In the bore 49 is received a plunger 5| which at its right-hand end (Fig. 4) is engaged by one end of a compression spring 53 the other 4end of which bears against the block 9. As seen in Fig. "l, when the Amandril M is inserted 'in 'the tool its Aend Aengages the plunger 5| and -moves ythe plunger Vto 'compress the spring 53. When the clamp screw 45 is loosened, vthe portion -of `the mandril Vremaining inthe -tool `is moved outwardly bythe plungeriil to remove it or permit its 'readyremovaL The tool is provided -with two cutters 55, 51 which swage and sever the stem of the mandril M after the Ariveting operation. The cutters 55., 51 VVare respectively 'held by screws 59 to a pair of jaws provided by llevers 5I, 63, the cutters having serrated faces 65 which engage similar serrated iaoes'onthe jawsto insure/that the cutters/maintain their positions with respect `to the 'jaws Referring to Figs. 1 and-5,'the lever .0| 'has Yformed on it two arcuate iianges 61 whichjare `separated by -a suflicient distance to allow clearance between themior'the rod "1. The lever 63 has formed on it two similar 'arcuate lianges 69 which 'areseparatediby a greater distance than the flanges 61'and straddle'the latter. 'Ihelever El has at each outer surface thereof (Fig. 5) an arcuate groove Tl and the lever B3 has similar arcuate grooves 13 which are arranged concentrically with the grooves 1I. Two plates 15, A11 areplovided, one at each side'o'f the levers, and each has a circular rib embedded in one of the grooves 1| and one of the grooves '13. A screw 3| is 'threaded 'in one of the flanges B1 and has an unt'hreaded portion 83 extending through bores in .one of the flanges -|59, the plate T1 and in the plate I. The screw 8| has a head 85 received in a counterboredportion of the plate l. The length of the portion 83 of the screw is sufficient to prevent clamping the .parts when the screw is tightened. Another screw 81 is threaded in the other flanges 61 y.and .has .an unbhrsadd portion 8.9 which extends throuehlbres in theY other flanges 69 and in theplate v15. The screw `81 has a head l9| which is received in Aa counterbored Yportion of the plate 15. The ribs 1,3 and grooves 1l, 13 provide bearing-surfaces permitting relative angular `movement of the levers, lil and 63 about an axis .perpendicular to ths'ais .of the'rod 1.

The-free ends of the levers 6|, 63 are offset Vto clear-the levers I1 (Fig. 4) and -areconnected by toggleflinks 951and .pivotpins S83 and 91, .thelatter also connecting the kneeoffthe toggle and the :yoke 99 of a stem 10| arranged toslide endwise .in a .bearing |03 which projects from the plate vl, The Lpath of the `knee of the togglefis parallel with the path of the mandril-gripping means. The stem IUI carries a headed screw |05 arranged to be struck and moved by the aforesaid head 35 when the collapsing movement of the lazy tongs is nearly spent. The adjustment of the screw L05 with respect lto the stem :l0-I determines the `location of the point of impact at which the head becomes effective to actuate the toggle. A lock nut |01 may be used to maintain adjustment.

Normally the cutters 55, 51 are separated as shown .in Figs. 1 and '1 by a tension spring |09 Whiohis stretched between pins on the levers 5| and 63. The separation of the cutters under the action of the spring |09 is limited by the enrgagement of the right-hand face (Figs. 1 and 4) of the yoke 50 with the left-hand face of the lug |03. Movement of the stem |01 toward the left (as looked at in Figs. 1 and 4) closes the cutters.

The cutters 55, 51 constitute a pair of blunt nippers'that swage the mandril stem in the process'of severing it. The operative end ||5 of the cutter 55 has two angularly related vfaces -which meet'to form a point, the angle of the point ybeing about '140 (Fig. 1). The faces I|1 of the cutter 51 form a yV-shaped trough or notch the vertex ||`9 of which is attened oli. In Fig. 7a the operative end ||5 of the cutter 55 at the locality of the point is of square section but the opposing surface of the cutter 51 is beveled to deflect some of the metal of the mandril toward the rivet. The arrangement is such `that when thevcutters are brought together the pointed end l5 tends to split the mandril stem by deflecting some of the metal at each side in a direction away from the axis of the stem. Consequently, when the lmandril stem is finally severed, the severed end of the portion left in the rivet will be swaged laterally beyond the 'diameter of the rivet bore. Using cutters of the character described (though it will be realized that other forms of swaging means might be used to give Adifferent deforming results) produces a fishtail formation F, the width of the Yishtail (Figs. 9 and l0) being appreciably greater than the original diameter of'the mandril stem, at the locality of severing, and greater than the diameter of the bore in the rivet.

The construction and arrangement of the elements are such that the lazy-tongs Vmechanism is effective first to pull the head of a mandril into a rivet and thereafter, but while .maintaining the pulling force, to cause operation of the ` cutters 55, 51. The operation of thecutters is derived from the aforesaid head or striker 35 after the levers |1 have beenmoved as faras need be `to complete the .rivet-setting operation. To allow continued movement of the lazy-tongs mechanism while thelevers v|.1 and the rod 1 remain stationary (or substantially so) but maintain the rivet-setting pull, the aforesaid Lpivot pins '23 are installed in the slots 25 inthe levers 21 and in .the slot 29 in thelever '3L Normally the pins -23 are maintained at the left-han'dends (as seen in Fig. 1) oi their slots by compression springs |2| which areseated at their right-hand ends in the levers 21 and 3|, and attheir lefthand-ends bear against small bearingvblocks |23 which are slidable and have incurved surfaces which `bear .against the rounded ends tof the levers l1. Consequently, when the levers H are arrestedzby the resistance encountered, .theknob 4| .and the head or striker "35 may .continuato move toward the left (as looked at in Fig. 2) .by

virtue of longitudinal movement' of the levers 21 and 3| along the pins 23 asv aresult of the lost motion afforded by the springs |2| and the pinand-slot connections. This feature enables the head 35 to engage thescrew [|95 and thereby operate the cutters 55, 51.

The plate I has a lug |25 in which are threaded a stop-screw |21 and a setscrew |29. The tool may, as hereinafter described, be operated in two different manners in one of which the stopscrew |21 is employed and in the other of which it is not'. In'the latter case it may be removed or screwed to the right (as looked at in Fi-g. 4) into an inoperative position.

To use the. described vtool a mandril M with a rivet R, thereon will be thrust into the bore 43 in the rod 1and clamped vtherein bythe screw 45. At this stage the lazy-tongs mechanism will be extended as illustrated in Fig. 2, the rod 1 will be in its extreme left-hand position (as looked at in Fig. 4), and the cutters 55,- 51 will be separated to allow the mandril stem .to lie between them. Before the mandril stem is clamped it will be moved to the right (as looked at in Fig. 4) until the head of the rivet R contacts with the front faces of the cutters 55, 51 (see Fig. l) The cutters serve, during the rivetsetting operation, as an anvil to hold the rivet head up to the work while the mandril is being pulled.

Having loaded the tool, the operator will next present the tool to the work (say two sheets of metal torbe secured together) which will have already had a hole formed to receive the rivet. The 'operator will hold the handle 3 of the tool in his left hand, leaving the right hand free to shift the knob 4| of the lazy-tongs mechanism toward the work. It will first be assumed that the stop-screw |21 has been removed or has been adjusted to an inoperative position.

vThe thrust exerted by the operator against the knob 4| causes the cutters 55, 51 to hold the rivet head firmly against the work. In addition, however,the lazy-tongs mechanism due to movement' about pins i9 moves the block 9 and rod 'l toward the right (as looked at in Fig. 4). This serves to pull'the head H of the mandril M into the setting end portion of the rivet and thereby to expand that portion of the rivet and draw the expanded metal thereof tightly against the work. The arrangement is such that until the mandril has been` pulled sufficiently to complete the up-` setting the springs I2! hold the levers 21, 3| so that the pins 23 are at the left-hand ends (as looked at in Fig. 1) of their slots 25, 29. When, however, the mandril has been pulled as far as Vit can go, the springs |2| will yield to permit the levers 21, 3| and links 31 to continue their collapsing movement despite stoppage of the lever |1. The construction is such that the striker 35 will have approached close to, but not yet struck, the screw |65 at the stage when the mandril is arrested, but eventually the striker will operate the cutters to swage the mandril and sever it adjacent to the head of the rivet. It will be appreciated that in setting a rivet the illustrative tool serves to maintain the rivetsetting pull on the mandril up till the moment when parting of the mandril stem occurs. It will also be appreciated that in the described operation of the tool the maximum pull imparted to the mandril is dependent upon the strength of the springs |2|. In setting rivets in work of different thicknesses the mandrils may need to be moved through. different distances but the' coming into operation of the cutters occurs only afterV the striker 35 has advanced far enough to engage the screw |05 which can be adjusted to postpone such engagement until the pulling motion of the mandril is arrested. If desired, the screw |21 may be adjusted to arrest the pulling motion of the mandril instead of depending upon the rivet and the riveted Work for that purpose, but in either case the springs |2| will permit and absorb the latter stages of collapsing movement of the levers 21 and 3| during which the toggle links will be straightened while the levers |1 remain stationary.

After a rivet has been set and the mandril severed, the tool will be removed from the work and the handle 41 will be turned to release the portion of the mandril which is left in the tool. Immediately that mandril portion is released, the spring 53 will operate the plunger 5| to eject the mandril portion or to move it into a position from which the operator can readily withdraw it The operation of the tool when the stop-screw 21 is operative is similar except that in this case' the stop-screw |21 will occupy a position (such as that shown in Figs. 1 and 4) in which it serves to set a predetermined limit to the distance through which the mandril may be pulled with respect to the rivet. Thus, in setting successive rivets of the same length in work of the same thickness with the same setting of the stopscrew |21 the mandrils will be pulled a uniform distance until the right-hand side (as looked at in Figs. 1 and 4) of the block 9 engages, and is stopped by, the stop-screw B21. The springs |2| then yield to permit further movement of the head 35 until it engages the screw |05 and causes operation of the cutters. The stop-screw |21 will be so adjusted that the stroke imparted to a mandril will lbe just sufficient to cause adequate setting of the rivet. With different thicknesses of work to be riveted, the stop-screw |21 may require to be set in different positions.

` A rivet R which has been set by the use of the illustrative tool in accordance with either of the aforesaid methods is shown in Figs. 9, 10 and 11. It will be seen that the head I-I of the mandril M has been drawn into the setting end portion of the rivet to expand the rivet and to'cause the work to be firmly gripped between the head of the rivet and the expanded portion of the rivet. The portion of the mandril left in the rivet serves to plug the bore of the rivet and considerably increases the shear strength of the joint. It will be observed in Figs. 9, l0 and 11 that the metal of the rivet at the setting end portion thereof not only has surrounded the head of the mandril but also somewhat contracted over the head of the mandril in a known manner. At the severed end of the mandril a fishtailF has been formed (see Figs. 9 and 10) of a width greater than the diameter of the bore in the rivet. This fishtail F will therefore serve as a second head on the mandril portion and, together with the preformed head H, prevent the mandril portion from being dislodged from the rivet. The side of the severed end part of the mandril shown in Figs. 9 and 10 is that which has been engaged by the cutter 55 and the fishtail at this side has a recess (best seen in Fig. 9) indented ,by the point of the cutter 55.

In Figs. 9, 10 and 11 the severed end of the mandril portion is shown as projecting slightly beyond the head of the rivet. Furthermore, .the throat of the rivet .has a slight 4flareiin which the fishtail may be nested or countersunk .by driving the mandril back to the position representedin Fig. l2. A light tap of a hammer will produce this result and will still leave the iishtail in a condition to retain the mandril in the rivet.

Having described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

l. A rivet-setting tool comprising means arranged to grip a portion of the stem of a .rivetsetting mandril, means arranged to swage and sever the stem between said gripping means and a hollow rivet surrounding another portion oi the stem, toggle means arranged to operate said swaging and severing means, a supporting structure by which said means are all maintained in assembled relation, and an actuating mechanism arranged to shift said gripping means and the knee of 'said toggle means successively and both lengthwise of the mandril to upset a rivet and swage the mandril.

2. A rivet-setting tool comprising means arranged to grip a portion of the stem of a rivetsetting mandril, means arranged to swage and sever the stem between said gripping means and a hollow rivet surrounding another portion ofthe stem, toggle means arranged to operate said swaging and severing means, a supporting structure by which said means are all maintained in assembled relation, a lazy tongs arranged toV shift said gripping means in a direction to upset the rivet with collapsing movement of the tongs, and a striker carried by an intermediate portion of the lazy'tongs for operating said toggle means with supplemental collapsing movement of the tongs after the rivet-upsetting component of such movement.

3. A rivet-setting tool comprising means arranged to grip a portion of the stem of a rivetsetting mandril, means arranged to brace the head of a hollow rivet surrounding the stem and sever the stern between the rivet and said gripping means, a supporting structure by which said means are maintained in cooperative relation, and an actuating mechanism arranged to shift said gripping means lengthwise of `the rivet far enough to complete the upsetting thereof `without bending the mandril or operating .said .severing 'means and thereafter to operate said severing means while continuing to stress .the .gripping means in the upsetting direction, said actuating mechanism including a yieldable connection that enables the mandril-gripping means to remain stationary while the severing means is in operation. l

4. A tool as set forth in claim 2 in which the lazy tongs .lncludesa lost-motion connection that enables the V-mandril-gripping means to remain stationary while the tongs foperate said -itoggle means.

i5. -A )rivet-setting tool comprising Vmeans -arranged to grip a portion iofthe-stemaof a `rivetsetting mandril, .means arranged to swage and sever .the stem betweensaid .gripping means and a hollow rivet surrounding another .portion of the stem, fa supporting fstructure by which said means are maintained in `assembled relation, :an actuating member, means vby which said actuating member is `guided toward and from the work along a path extending lengthwise lvoi the mandril, .and means operable by travel of 'said actuating member toward the work for shifting said gripping means in the opposite .direction to upset .a rivet, said .swaging and .and severing means lbeing operable bytfurther travel of said actuating member toward the Ywork after vcompletion of the rivet-upsetting component oi fsuch travel.

6. A tool 'as 'set forth in claim 2 in which `the toggle .means includes an :adjustable member arranged to vary the location of the point inthe path of said striker at which .the latter becomes effective to operate the toggle means.

7. A rivet-setting ,tool .comprising 'means arranged to 'grip a portion .of the stem of fa rivetsetting mandril, a pair of jaws provided with blunt nippers arranged to swage and sever 'the stem between said gripping means and a hollow rivet surrounding .another portion of the stem, said nippers having one 'a point to indent `and spread a 'portion of the mandril 'stem :and the other having angularly `related stem-engaging faces forming a notch `in register with `said point, a supporting structure by which said means and said jaws are maintained in assembled relation, and an actuating mechanism 'arranged 'to shift said gripping means and thereafter operate said jaws and thereby upset the rivet -before closing said nippers.

'LUCIEN PAUL MELLERIO. BASIL POMEROY COOPER.

REFERENCES CITED The following vreferences yare of record in the file of vthis patent-z UNITED STATES PATENTS Number -Name Date 1,7 66,035 Nielsen June 24, `1930 FOREIGN PATENTS Number Country Date 371,817 Italy July 5, 1939

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