US2797596A - Rivet guide and pressure pad assembly - Google Patents

Description

July 2, 1957 G. F. sEELY l 2,797,596

' RIVET GUIDE AND PRESSURE PAD ASSEMBLY Filed Dec. 2, 1952 4 Sheets-Sheet. l

' .y v l lNvENToR mi "um Y $0,600 625545)/ I BY ATTORNEY July 2, 1957 G. F. SEI-:LY 2,797,596

' RIvET GUIDE AND PRESSURE PAD ASSEMBLY Filed De, 2, 1952 l A sheets-mer. 2

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Elif- INVENTOR faena/v 555545)/ W M A ATTORNEY G. F. SEELY RIVET GUIDE AND PRESSURE PAD ASSEMBLY July Z, 1957 4 Sheets-Sheet. 5

Filed uw. 2, 1952 INVENTOR @fad/v H ffzf X BY M W ATTORNEY July 2, l957 G. F. sEELY 2,797,596

i EIvET GUIDE AND PRESSURE PAD ASSEMBLY l Filed Dc. 2, 1952 4 sneetssneet 4 ATTORNEY United SMCS Patent nrvEr GUIDE AND PRESSURE PAD ASSEMBLY Gordon F. Seely, Utica, N. Y., assgnor to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New York Application December 2, 1952, Serial No. 323,619

6 Claims. (Cl. 7852) rlhis invention relates to a rivet guide and pressure pad assembly for a riveting machine.

In riveting operations, particularlywhen the work consists of large sheets, it is often diicult to align the rivet with the rivet dolly prior to heading the rivet, since the rivet dolly is obscured by the sheets. Much time can be spent by the operator in making certain that there is proper alignment, and he is subject to error due to haste, or misjudgment, which renders the riveting operations inefficient and accordingly costly. Furthermore, in the riveting together of stacked sheets, it is important that the sheets be firmly pressed together during the riveting operation so that the rivet is properly set, and to prevent spreading out of the rivet between the sheets, the latter which assure proper alignment of a rivet with a rivet dolly prior n to rivet heading.

Another object is to provide a means whereby the `work i on which the riveting operations are being performed isk firmly held together during the riveting operation.

A further object is to provide an assembly including a rivet guide means and pressure pad means which can be easily attached to a riveting machine, which is simple in structure, reliable in operation, of low initial and maintenance cost, and which will improve the efficiency of riveting operations, particularly when working on large sheets.

These and further objects of the invention will become more apparent from the following specification and the relative drawings, wherein:

Fig. l is a partial view of a stationary riveting machine, showing an embodiment of the subject invention, as applied thereto;

Fig. 2 is a sectional view of the subject invention as attached to the riveting machine, and at twicethe scale as shown in Fig. 1;

Fig. 3 is a plan View as seen from line 3-3 of Fig. 2;

Fig. 4 is a plan View of a rivet guide element shown in Fig. 2;

Fig. 5 is a sectional view of the rivet guide element as seen from line 5-5 in Fig. 4;

Fig. 6 is a fragmentary plan view of the underside of the end of the rivet guide element, and at twice the scale as shown in Fig. 4;

Fig. 7 is a plan view of a pressure pad element as shown in Fig. 2;

Fig. 8 is a sectional view of the pressure pad element as seen from line 8 8 in Fig. 7;

Fig. 9 is a fragmentary plan view of the underside of the end of the pressure pad element as shown in Fig. 7;

Fig. 10 is an end view as seen from line lll-10 of 'ice Fig. 2, and showing conditions existing after rivet alignment with the rivet dolly and just prior to commencement of the rivet heading operation;

Fig. 10a is a sectional view as seen from line 10a-10a of Fig. l0, and at approximately one-and-a-half times the l Fig'.- lla is a sectionalview as seen from line 11a-11a of Fig. r11, and at approximately one-and-a-half times the i scale of Fig. 1l;

Fig. 12 is an end view similar to Fig. l0, but showing the conditions existing at a late stage in the rivet heading operation;

Fig. 12a is a sectional view as seen om line 12a-12a, of Fig. l2, and at approximately one-and-a-half times the scale of Fig. l2;

Fig.` 13 is an end View similar to Fig. l0, but showing the conditions existing at the completion of the rivet headl ing operation, and with the riveting machine plunger being retracted and out of engagement with the rivet; and

Fig. 13a is a sectional View as seen from line 13a-13a of Fig. 13, and at approximately one-and-a-half times the scale of Fig. 13.

Referring now to Fig. l, numeral 20 indicates a riveting -A machine of generally standard style well known to the Y, art, and having C type jaws, an upper jaw 21, and lower jaw 22, the upper jaw 21 having mounted thereon a cylinder 23, in which is reciprocably maintained a piston y 24, to which is aixed at the lower side a plunger 26. 1

At the top end of cylinder 23 is a hose 27, which admits pressure iiuid, such as oilfor air, to the upper end of the f cylinder to drive the piston 24 downwardly for the riveting operation, while at the lower end of the cylinder is a hose '28, which admits pressure uid to the lower end of the cylinder to raise the piston after completion of the riveting operation. The alternate conduction of pressure iiuid through hoses 27, 28- is achieved by means of a common type of auxiliary pressure unit, not shown.

A rivet guide and pressure pad assembly 29,- illustrative of an embodiment of the invention, is shown attached to the lower jaw 22 of the riveting machine. As more clearly seen in Figs. 2 and 3, the assembly 29 comprises a pressure pad element 31, and a rivet guide element 32, which is secured to the top of the pressure pad, such as by means pressure pad 31, said spring being under compression to urge the assembly 29 toward uppermost position, as shown. A set screw 38 is arranged near the end of the pressure pad 31 and is extendable from the underside thereof to engage the surface of lower jaw 22 to regulate the extent of the uppermost position of the assembly.

A rivet dolly 39 is removably seated in -the lower jaw 22, the top end of the dolly being shaped to conform to f the type `of rivet head it is desired toi form. The dolly 39 is of course in axial alignment with the piston plunger v As best seen in Figs. 7 to 9, the pressure pad 31 has a slot 41 at the free end to allow for clearance with the body of the dolly 39, while on each side of the slot is a Q lraised portion, or boss 42, the top of which supports the free end of the rivet guide 32. The slot 41 has a chlamfer 43 to assure full clearance with the body of the dolly 39,

for the style indicated. Ears 34 may be integral with i Patented July 2, 19575.

the pressure pad 31, or be separately formed and welded thereto, as shown.

The rivet guide `element 32 is fashioned from a flat prece `of metal, a .free-end portionl44=pbeingrstepped .11p-

wardly so thlatwhen assembled toth'epressure-,padi :31, the

bottom of end portion 44 willengage-thetop'surface-of the bosses 42, and be supportedthereby. Anrelongated holel 46, formed .in .the rivet guide 32, removes `amajor portion of the body of the rivet guide, while a `slot 47, splits the end portion 44. By means ,of .such `construct1on, the halved portions or nibs `45of the end portion 44, can'be Yforced apart, and will resume original position .when released, due to the resiliency ofthe metal Vfrom which thexrivet guide isformed. In `the end'portionv44, is 'formed a V-shaped slot 48, at the vertex 'of which is formed la hole 49, part yof.thecircumference of-'said hole being eliminated bythe slot 48. At the underside of the nibs 45, and surrounding hole 49, is formed a counterbore 51, thepurposefor which. willbe lbetter understood hereinafter. The diametenof hole 49 .is slightly larger than the shank of the rivet to be headed,.the .center of hole 49 being in alignment .with the center of the dolly 3 9, when the assembly 29, is mounted in Working positron on thelower jaw 22.

Considering now the operation of the invention for,

riveting operations, rivets 25 '(orily one shown) are rst placed in preformed holes in work sheets 30, so that the unheaded Shanks extend beneath. While the drawings show a, plurality of work sheets, the two upper sheets thereof being of greater thickness than the bottom sheet, and Va fiat head rivet 25 having `two shank diameters, it is to be understood that the sheets need not be of such number, nor-*of different thickness, nor need the rivets be'of such'style, or of varying diameter, since the invention `Will work-equally well with any number of sheets, tand anytype of rivet, so long as the extendedrivet shank can beproperly engaged bythe rivet guide nibs '45.

The-operator now moves the work sheets 30, with extended rivet "25, in the direction ofthe assembly 29 until `the'shankof the `rivet engages a portion of slot 48, of the rivet guide 32. -Further movement of the sheets toward the assembly resul-ts in the rivet shank being finally positioned within'the hole 49; it is to be noted that the rivet shank will slightly spread the nibs 45, 'in the process of -entering the hole 49, so that a snap action is effected-whereby the rivet shank is locked in proper'position. The `rivet being lnow Iautomatically in correct'alignment `with the dolly 39, the rivet heading operation can begin.

`Referring now to Figs. l to 13a, the rst of said figures illustrates the condition immediately preceding the beginning ofthe heading operation. The piston plunger 26 `has engaged the top of the rivet and motion downwardly, i. e., toward the dolly 39, is about to begin. Fig. a shows, in enlarged manner, the relative position, land condition of the `rivet at said stage of the operation.

In Figs. 11 and 11a, the rivet 25 has engagedthe dolly 39and heading of the rivet has'begun. Note that the pressure ofthe plunger 26 has forced the stacked sheets, rivet, and the assembly 29, downwardly with the result that `the spring 37, ,acting through the pressure pad 31, land -rivet guide portion 44, has caused Athe work sheets 30 to be firmly pressed together. `Further notice may be `had that the nibs have been forced apart slightly, due to the fact-that the shank diameter of the rivet has been increased as a result `of the pressure reaction by the dolly 39.`

In Figs. l2 and 12a, the heading of the rivet has further progressed so that la portion of .the rivet head being formed has already engaged the underside ofthe bottom, work sheet, in the area adjacent the rivet hole. The pressure of the spring 37 is still pressing the work sheets firmly together, while the nibs 45, have been forced further apart. The spreading of nibs 45 expands the counter- 4 bore 51 to a size which permits the upper dolly `39 to enter within the counterbore.`

In Figs. 13 and 13a the rivet head has been fully formed, land the piston plunger 26 is shown moving away from contact with the top end of the set rivet. The work sheets have been moved Vupward ,to initial position, due to action of the spring 37, while the nibs 45 have been fullyexpanded, and are in engagcment'withthe sides of the newly formed rivet head. It will be seen that the counterbofre 51, 'formed about the hole 49 in theguide portion 44, allows `the metal sheets to be moved `closer to the dolly 39, so that a rivet head yof shorter height 'but grefater-areamayrbe formed.

The operator now pulls the riveted sheets away from the assembly 29, and as soon asithe nibs 45 release the rivet head they snap back into initial position. The operator can now repeat the riveting operations on the next rivet in substantially the same fashion.

The axial pressure exerted on the rivet by the hydraulic piston 24 will vary according to the size of rivet, material of the rivet, 'type of head to be formed, hardness of the rivet, and whether it is to be squeezed hot or cold. This ,pressure is Iimmaterial insofar as this invention is concerned except that it must be sufficient to form a given head on la given rivet, and at the same time spread the rivet guide 32 .with the radial pressure resulting from the forming of the head of the rivet.

It will be appreciated that the spring37 is designed for satisfactory operation within agiven range, hence, when thin sheetsfare to beriveted, the proper spring size will depend upon the conditionof the sheets, i. e., flatness, irregularities, etc. The yrivet guide nibs 45, do not exert 'enough pressure upon the rivet shank to have any effect on 'the final headshlape; the desired form of rivet head isimmaterial-since the invention is equallyefective when forming heads of the ush type, or countersunk type. The dimensions of the pressure pad and rivet guide depend upon the rivet size, type of head to be formed,

space requirements, etc. Such design factors are those which can `be ,established by persons skilled in the art, having once been given the general idea of the features and possibilities of the subject invention. Furthermore, While the `invention has been shown and described for operations on rivets arranged with the heads on top and with the unheaded shanks extending from the underside of the work sheets, it is conceivable that the invention -could be easily adapted for use on rivets whose Shanks extend upward from the top side of the work sheets, if such an arrangement would be found desirable.

While an embodiment of the invention has been shown as applied to a stationary type of riveting ma chine, it will be recognized that the application is not limited thereto, it being possible to utilize the invention on machines of the portable type, and further, 4that certain re-arranging, alteration, and redesigning may be effected without departing from the spirit of the invention as set forth in the appended claims.

If desired,.either the rivet guide 32 or the pressure pad 31 could be used separately to serve its particular purpose or they can ybe `used in cooperation with each other as shown.

What is claimed is:

l. In a riveting machine, an assembly for attachment to a lower jaw of the machine comprising in combination, a rivet guide element having a rivet guidingand holding means for locating a rivet in proper position for the heading thereof, a pressure pad element pivotally aixed at one end to said lower jaw and aixedly supporting said rivet guide element, and a compression means acting on the pressure pad element to urge the assembly away from the lower jaw of the machine,

wherein the guiding and holdingmeans of the rivet guide i element includes a pair of nibs resiliently arranged for movement in a horizontal plane, and having a rivet maintaining portion including a rivet guiding slot.

`end of the` 2. In a riveting machine, an assembly according to claim 1, wherein the nibs are integral with the body of the rivet guide element, and wherein the rivet maintaining portion includes an area of reduced cross-section, while the rivet guiding slot is V-shaped, the apex thereof being in the rivet maintaining portion.

3. In a riveting machine, an assembly according to claim 2, wherein the rivet maintaining portion of the rivet guide element is arranged to provide a hole having a diameter the center of which coincides with the center of a rivet heading dolly positioned in the lower jaw of the riveting machine.

4. In a riveting machine, an assembly according to claim 3, wherein the nibs are adapted to be forced apart as a result of the rivet head being formed, and which are adapted to assume initial position when the formed rivet head is withdrawn therefrom.

5. In a riveting machine, an assembly according to claim 4, wherein the nibs are in a raised horizontal plane relative the horizontal plane of the major portion of the rivet guide element, and wherein the under surface of each nib is in engagement with bosses formed on the top of the pressure pad element.

6. In a riveting tool for use in operations in which the unheaded rivet Shanks project from the underside of the work piece, including a yoke member, a rivet dolly disposed in a lower arm of the yoke, and a piston plunger disposed in the upper arm of the yoke in axial alignment with the dolly; a rivet guide and pressure pad unit comprising: an elongated rivet guide element having at its forward end a pair of fingers resiliently spreadable in a horizontal plane so as to guide the shank of a rivet through a V notch defined between the ends of the fingers to a hole at the vertex of the notch, the hole being of a diameter slightly greater than that of the shank permitting the fingers to resiliently clamp about the latter after the shank has been received in the hole; a pressure pad in underlying supporting 'contact with the guide element, having at one end a bifurcation beneath the hole and V notch of the guide element and closely receiving therein an upper portion of the dolly; the opposite ends of the guide element and pressure pad being fastened together and pivotally supported by a common pivot pin as a unit to the lower arm; spring means urging the forward end of the unit in an upward direction about the shank of a rivet received in the hole of the guide element; and adjustable means in the rear of the unit engageable with the lower arm of the yoke to limit the extent of the said upward movement of the unit.

References Cited in the le of this patent UNITED STATES PATENTS 687,289 Thornton Nov. 26, 1901 1,328,905 Sexton Jan. 27, 1920 1,675,773 Tissler July 3, 1928 2,148,883 Taylor et al. Feb. 28, 1939 2,377,032 Osborne May 29, 1945 2,511,506 Hruby June 13, 1950

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