US2654257A - Electrically powered blind riveting tool - Google Patents

Description

Oct. 6, 1953 J. N. HENSHAW 2,654,257

ELECTRICALLY POWERED BLIND RIVETING TOOL Filed Dec. 30, 1950 2 Sheets-Sheet 1 Inventor James N. Hens/70w Oct. 6, 1953 J. N. HENSHAW 4, 7

' ELECTRICALLY POWERED BLIND RIVETING TOOL Filed Dec. 30, 1950 2 Sheets-Sheet 2 Inventor B (S A orne y rfiwnes N Hens/10w Patented Oct. 6, 1953 U NIITZE'D PATENT o-FFIC .J ameszNorman-Henshaw, Leicester, .England, as-

signor -to United :Shoe Machinery Corporation, Flemington, .N. 41., .a corporation 'of. New-Jersey 'Application December 30, 1950, TS'erlal No. Z3,610 Jln'eGrcat T-Britain February' .8,.:1.95ll

,1 .Claim. 1

This invention relates to means for imparting reciprocating motion-to axto'ol powered by a rotor. As hereinafter exemplified the inventionupertains especially to power-operated blind riveting tools and more particularly to an electrically driven tool of a type adapted to .install a two-part rivet in a structure accessiblefrom one side only. It will be understood that-use-of the inventionisuby no means necessarily limited to application in riveting tools.

A common form of blind rivet comprises 'a tubular member of ductile metal having apreformed head anda nail-alike mandril extending axially through the throat of .the member. .A powerful riveting tool is required first togrip and retract the stem of the mandril endwise relative.

to the member so that the mandrilhead will-upset .and expand the inaccessible endof the member, and second, to tension the .mandril'further after the upsetting so:that theeexpendable .mandril stem'is separated .from theinstalled rivet. .A manual-type tool'used to insert-such rivetsand employing mandril-gripping tongs with high mechanical advantage is, for example, disclosed in U. S. LettersPatent No. 1,829,696 granted to H. N. Wylie et al. Also, power-operated tools of-pneumatic and hydraulic types have hitherto been quite extensively used for setting -blind rivets. For developing the requisite fluid operating pressures in these devicesrather .cumbersome and costly apparatus and controls therefor have usually been needed, although in some instance the organizations have included separately .maneuverable hand tools for applying the rivet..setting forces-transmitted to them.

A primary object of this invention is to provide an improved means for changing rotary .motion, such as that of an electric motor, to reciprocating motion for effectively actuating aremote instrumentsuch as a riveting tool which may be readily manipulated at the rivet setting locality.

In accordance with this objecta feature of the invention is the provision in a' blind riveting tool comprising a normally stationary power unit including a member rotatably driven by electrical means, of a rivet manipulating hand unit, a flexible cable for transmitting axial movement of the memberto actuate thehand unit, and means .for deriving such axial movement of the member during its rotation.

Theaboveand other'features of the invention, together'with 'novel arrangements and combinations of parts will now'be'more fully-describe'd'in connection with one illustrative embodiment and the accompanyingfdrawingsthereofjln' which".

Eig lis a side elevation, partly in section, .of the rivet manipulating hand unit of a preferred form of tool embodying the invention, portions of the casing being broken away toreveal details of construction;

. Fig. 2 is a sideelevation, .partly in central longitudinal section, of the powerunitportion of the illustrative tool; and I .Fig. 3ris-a detail of speed; reduction ,parts'taken on :a plane connecting arrows A and as viewed when looking :in :thezdirection of the arrowsAin Fig. 2.

vThepower unit v'comprisesan electric motor I 0 (Fig. 2),,,=pr.eferably1o'f about 4/4 H.1P.,:to which is affixed a .reductiongear :housing'-I-Zhaving-a1base plate l-4 .secured'byboltstoa cradle I16. .-A housing :IZBior the major portion :of the ,actuating mechanismis secured-by bolts 29 to the housing 1.2, the housings 2 .and It :being: spaced. bye-a *cylindrical member -212.

Adriveshaft 2'4 of the .motor l0 isxcoaxialwith a driven shaft 326 .rotatablyimounted within the housing :l'8. Viewing Fig. 2 :irom the left, rotation of .the' shaft;2-4 is in a counterclockwise direction, enlarged portion mnofktheshaft 25 is carried :in :a :ball bearing I39. :speed lredu'ction mechanism of any .typieian'd hereirrgenerallyidesign'ate'd 432 may :-be "used ;in coupling -.tl1e *shaft J4 and shaft portion 223. .The zre'ducti'on gearing about :to be described .is of :welleknown type'arid is,;in this -instance,ipneferably arranged 13021601782139 the shaft 26 "at 3/ oftthesspee'diofithe shaft 24. .:A gear. 34 is :rotatablyimounted on anteecentrictportion 36 of the ishafti iland held against'endwi-se movement iin one :ldire'ction aby a I flange 38 of the latter. An internal' gear fi (Figs. 2ia'nd 3) fixedly.'mounted on the boltsIZil, :h as 'fil teeth, and meshes with the gear 34 having teeth. The gear-3'4is accordingly rotated 'Lthe speed of the shaft 924 :but -in' the opposite direction. Rot'ation ofthe gear .34 is transmittedto the shaft 26 byia coupling of the well-knownioldham type, :thegear 3'4::having'-an1integral spline 42 arrangedito slide f'll'lffa iceyway of :a :conpling disk 44.. The disk 44 isprovided With-a secondikeyway at rightzang'les toitheione just mentionedin orderitoxaccommohatea-spline' i'e integral with theshaftpor-tionfiii.

The housing 18 1s providedwi-th an internal cylindrical bearingor 'surface' 48 'for 'a-cylindrica-l cam 50 mounted on the shaft 26. This "cam 5t ofthe'power-unit iscapableofipiston like'movement axially of the bearing "'48 to actuate "the hand unit in a "manner hereinafter't'o be described. Accordingly, the cam 50 is'spli ned'to the shaft 2% "for rotation therewith "and is "secured to means connecting with the hand unit as will now be explained. An annular plate 52, secured to an end of the cam 58 having a cavity, serves to maintain a thrust bearing 54 therein and against a flanged portion 56 of a sleeve 58 which extends coaxially of the cam 50 and through the bearing and through the plate 52. A portion 66 of the sleeve 56 is of reduced diameter providing a shoulder 62 against which a sleeve 64 is clamped by means of a nut 66 threaded on the sleeve 58. The sleeve 64 is provided with a keyway 66 and is arranged for axial movement in a bearing I formed in the housing I6, a pin I2 projecting from the latter and engaging the keyway 68 to lock the sleeve 64 against rotation. A rod I4 threaded into the sleeve 58 receives one end of a stranded central wire or cable portion I6 of a Bowden cable. A flexible outer casing 18 of the cable terminates in a sleeve 86, a reduced portion of which fits in a bore in the housing I6. An outer sleeve 82 and a cap 66 screwed onto a boss of the housing I8 secure the sleeve 88 in position.

When the tool is not in operation, and though its motor Ill be running, the sleeve 56 is stationary, its relative position being as shown in Fig. 2. In this initial position the sleeve 58 is releasably held by engagement of a springpressed plunger 66 with a recess in the sleeve 64. Also, as viewed in Fig. 2, the plunger 86 is then holding the idling cam 56 at the right-hand end of the bearing 48.

Means for cooperating with the cam 56 to move it axially of the housing I8 are mounted in a cylindrical member 88 secured thereon. A cam slot 96 formed in the cam 56 is of rectangular cross section, having opposite side walls 92, 94 and a bottom wall 96. The walls 82, 94 are radial, and a bearing 98 mounted for vertical movement in the member 88 rotatably supports a cam roll I00 by means of a stud I02. The bearing 98 is backed by a compression spring I64 which urges it downward to effect engagement of the roll I66 with the slot 96. To permit free rotation of the cam 56, the roll is normally retained above the slot by means of a pawl I06 pivotally aflixed by means of a pin II]? to the member 68 and engageable with an annular groove I68 formed in the bearing 98. The bottom wall 96 of the groove,

if considered as progressing in one direction around the cam 56, is of gradually diminishing depth until the bottom wall merges with the external cylindrical surface of the cam 50. In this locality of the merging, the wall 96 is in a position so to raise the bearing 98 and roll I06 that the pawl I86 may engage the groove I68 and maintain the roll I09 in its lifted and inoperative position.

The hand portion of the tool, shown in Fig. 1, comprises a casing III] to which a pistol grip handle H2 is aifixed. The casing III) has a centrally bored, conical anvil I I4 secured to one end and provides a cylindrical bearing for a sleeve I I6 coaxial with the anvil. Connections with the cable I6, to be described, are provided for moving the sleeve II6 relatively to the anvil, and mechanism within the sleeve and actuated thereby is employed to grip and retract the mandril portion of a rivet to be installed. Any suitable mandril gripping and tensioning mechanism may be used, a preferred type somewhat similar to that disclosed in the above cited Wylie et al. patent being hereinafter described.

An end of the sleeve II6 adjacent to the anvil has an internal frusto-eonical surface 8. A

plug I26 secured in the other end of the sleeve II6 engages one end of a compression spring I22, its other end engaging a block I24. The latter supports a pair of leaf springs I26, I26 to each of which a collet jaw I28 is afilxed. The arrangement is such that the jaws are urged apart, the spring I22 urging the jaws I28 toward the surface II8. Actual movement of the jaws into cooperative relation with that surface is controlled by a spring-backed latch I68 (one form of which is more fully disclosed in my copending application Serial No. 188,930, filed October '1, 1950, now United States Letters Patent No. 2,575,416, granted November 20, 1951) extending transversely through the casing IIB. A pivot pin I34 extends transversely of the sleeve II6 to bridge a pair of parallel and opposite flat links I36, I36. Each of the upper ends of the links I36 is pivotally connected to an end of a link I38, the links I38, I38 being pivotally afiixed at their other ends to the casing III). The lower ends of the links I36, I36 are bridged by a pin I46 to which a sleeve I42 fast to the cable I6 is pivotally secured. The cable casing 73 terminates in a sleeve I44 clamped in an extension piece I46 of the casing H8.

For controlling the pawl I66 of the power unit a trigger I58 associated with the handle H2 is arranged to be manually depressed against the resistance of a spring I52, thereby closing a switch I 54. A wire I56 preferably bound to the cable casing I6 connects the switch I54 with a source of electrical energy and a solenoid I58 (Fig. 2) mounted on the housing I8. A core I68 of the solenoid is arranged to be drawn against the resistance of a spring I62 when the solenoid is energized by pressing the trigger I58. A pair of links I64, I64 (only one shown in Fig. 2) is pivotally supported on the core I66 and has pivotal connection with a shifter yoke I66. The latter straddles the member 88 and is fulcrumed on the pin H68 aflixed thereto. A forked end of the yoke I66 embraces a pin I10 secured to the pawl I06.

In operating the illustrative tool, its parts initially being in the relative positions indicated in Figs. 1 and 2, the mandril stem of a blind rivet is first inserted in the bore of the anvil I I4 and extends between the collet jaws I 26, the preformed head of the tubular portion of the rivet abutting the anvil externally. The latch I38 is next actuated to enable the spring I22 to move the jaws against the surface I I8 and so cause them to engage and grip the mandril. When the hand unit has been moved as required to insert the projecting portion of the rivet assembly in the hole in a structure to b riveted, the anvil I I4 should hold the preformed rivet head against the accessible Side of the structure. The trigger ISO is then depressed, the energized solenoid I58 acting against the spring I62 via the core I66, links I66, and yoke I66 to pivot the pawl I66 on the pin I61 and so disengage the pawl from th groove I88. The released bearing 69 and the roll I60, under the influence of the spring Hi l, are moved toward the cam 56. As soon as the latter has rotated its cam groove 66 so as to permit entry of the roll I66 therein, the roll and groove cooperate to effect axial movement of the cam 56 together with the sleeves 58 and 64. The path of the groove 96 is such that during rotation of the cam 56 through the initial its axial movement is to the left as viewed in Fig. 2, the sleeve 56 and the rod I4 also thereby being pulled to the left. As a result the recess in the sleeve 64 is shifted to the left and out of alignment with the plunger 86, and the cable I6 is pulled in a working stroke in one direction relative to its casing I8. But in the next 180 of a working cycle the efiect of the groove!!!) and roll I89 is to move the cam to the right and back to its initial position, the cam acting against the flanged portions 56 of the sleeve 58 and relatively shifting the cabl I6 and the sleeve 64 until the plunger 89 is again seated in the sleeve recess.

As a consequence of the cable I6 being retracted within the casing 18 by operation of the power unit during the first half of its cycle, the mandril gripping mechanism of the hand unit is actuated, the links I36, I36 being swung counterclockwise (viewing Fig. 1) by the cable. Accordingly, the sleeve I I6 and closed collet paws I28 are separated from the anvil I M to tension the mandril, upset the tubular rivet, and finally strain and break the mandril stem. The operator releases the trigger I50 as soon as the mandril has broken, thereby deenergizing the solenoid I58 and freeing the pawl I95 for engagement with the groove I09 under the influence of the spring I62. The groove I98 is positioned for this engagement during the second half of the cycle by means of the bearing 98 being raised by the lifting action of the bottom wall 96 on the roll I99. Also, the return movement of the cable 16 relative to its casing I8 during this second half of the cycle seats the plunger 86, returns the sleeve H6 and jaws I28 to the relative positions indicated in Fig. l, the jaws then being apart for the reception of the next rivet to be installed.

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

A power unit for driving reciprocable remote mechanism of a manually movable tool, including a cable connected to said mechanism, and normally fixed power means for shifting said cable to operate said mechanism, said means comprising a motor, a rotary cam connected to said cable and driven by the motor, said cam having a pcripheral groove extending with increasing depth through 360 of rotation and between axial extremes spaced to correspond with 180 of rotation, a member mounted on the power means and engageable with the cam groove to move the cam back and forth axially, means associated with the power means for retaining the member disengaged from the groove when the cam has completed a cycle, and means, responsive to the closing of an electrical circuit, for releasing said member retaining means.

JAMES NORMAN HEN SHAW.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,053,7 8 Huck Sept. 8, 1936 2,088,859 Huck Aug. 3, 1937 2,205,772 Bowersox June 25, 1940 2,474,056 Larsen June 21, 1949 2,478,886 De Swort Aug. 9, 1949 2,484,471 Shinn Oct. 11, 1949 2,548,411 Vache Apr. 10, 1951 2,578,599 Korsgren Dec. 11 1951

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