US2774430A - Latching means for die set retainers - Google Patents

Description

Dee. 18, 1956 w. J; BLAZEK LATCHING MEANS FOR DIE SET RETAINERS Filed NOV. 8, 1955' /0 INVENTOR W'JfilaZek United States Patent '0 LATCHING MEANS FOR DIE SET RETAINERS William J. Blazek, New Lexington, Ohio, assignor to Lempco Products, Inc., Bedford, 01110, a corporation of Ohio 7 Application November 8, 1955, Serial No. 545,694 8 Ciaims. (Cl. 164- -118) This invention relates to guide appliances for the die sets of punch presses and other reciprocatory machine tools.

A punch and die set is an assembly consisting of an upper member called the punch holder or plate and a lower member called the die holder or plate. The lower or under surface of the punch holder and-the upper or top surface of the die holder are those on which the punch and die sections of a finished punch press tool are mounted, although these positions are sometimes reversed. In use, the die holder is clamped to the bed or bolster plate of the punch press, while the upwardly extending punch holder shank is fastened in the clamping hole provided therefor in the sliding punch press ram. The tool is actuated by the reciprocating motion of the ram. Mating guide posts and bushings of an assembled die set assist in maintaining tool alignment during die setting and the operation of the tool in the punch press.

These guide posts and bushings are employed in maintaining the punch and die details in true alignment or registry during ram-produced reciprocatory movement of at least certain of the ball bearings therein are disposed under compressive loading forces.

Accordingly, it is an object of the invention to provide an antifriction guide assembly for die sets wherein improved means are provided for efiecting proper position- 7 ing of the bearing-carrying retainers of such guide assemthe punch and punch holder relative to the die and die holder. In conventional constructions, the posts are of plain cylindrical formation and are carried by and depend rigidly in relatively spaced order from associated punch holders. These depending postsare received and have a close working fit in longitudinal holes or bores formed in cooperative die holder mounted stationary bushings. The operation, longevity and accuracy of such plain guide posts and bushings have been improved by interposing pressure-loaded antifriction bearings between annularly spaced surfaces of the posts and bushings, as disclosed in the prior patent to Connor, No. 2,422,774, granted June 24, 1947.

In such antifriction guide devices, die alignment is obtained by providing one of the holders, usually the punch holder, of a die set with a bushing having a cylindrical bore formed therein for receiving a cylindrical coaxial post provided on the other holder when relative movement of the holders during Working strokes of the press takes place. Undesired lateral motion in such guide devices is precluded by providing each device with a tubular retainer or' sleeve carrying a plurality of spaced ball elements of uniform diameter, each of the elements having a diameter slightly greater than the width of the annular space formed between the post of the appliance and adjacent inner cylindrical surface of the bushing bore repress, and at the same time to maintain the retainers U throughout such stroke movements in positions in which blies, whereby to cause the retainers to be maintained in alignment-producing and antifriction engagement with associated stationary and movable guide members.

Another object of the invention is to provide an improved guiding and alignment-maintaining assembly for machine press die sets having movable bearing-carrying retainers disposed in coaxial relation with interfitting stationary and movable guide members, and wherein positive and simplified means are provided for maintaining such retainers, at all stages of relative movement of said members, in predetermined operative order with respect to said members, whereby to maintain at least certain of the bearings of said retainers under confined conditions of compressive loading and yet to permit the same to move longitudinally of the guide assemblies concomitantly with the movable members thereof but at a different rate of linear speed.

A further object is to provide the ball-bearing-carrying retainers of such guide assemblies with yieldable stop means adapted for engagement with associated stationary members of the assemblies, whereby to determine proper initial operating positions of the retainers in admitting of antifriction retention thereof in association with the interfitting stationary and movable members of the assemblies throughout their operating strokes, said stop means being automatically retractable to assume inactive positions when engaged by said members. during periods-of relative longitudinal movement therebetween,

For a further understanding of the invention, including additional objects, constructional andoperational features and advantages thereof, reference should now be had to the following description and accompanying drawing,

wherein: Y

Fig. 1 is a view partly in side elevation and vertical section of an antifriction guide assembly for machine press die sets, and illustrating the bearing retainer stop and locating means of the present invention incorporated therein;

Fig. 2 is a fragmentary detail vertical sectional View disclosing on a greater scale one of the enlarged ballbearing-receiving seats of an antifriction guide assembly retainer formed in accordance with the present invention, and showing the ball-bearing occupying an enlarged seat resiliently displaced in-an outward direction for retainer- Fig. 4 is a view similar to Fig. 1 and illustrating another modified form of the present invention, wherein the stop means for indexing the operative positions of the bearing retaining members comprise spring-pressed post shoulderengaging catch devices separate from the bearings of the sleeve members;

.Fig. 5 is a fragmentary detail vertical sectional view on an enlarged scale of one of the catch devices of Fig. 4 and associated parts; a

Fig. 6 is a detail plan view' of a resilient split ring or band adapted for use in connection with the foregoing stop and positioning determining devices. Referring to the drawings by numerals, and more particularly to the. disclosure contained in Figs. 1 and 2, the

movable punch and stationary die holders 10 and 11,

1 respectively, of a die set, are provided with one or more antifriction guide assemblies 12. The latter are employed for maintaining the holders 1!) and 11', and parts carried thereby, in proper alignment or positions of :r'elative registryduring working movements of a p'un'lchfpress, or other machine-tool on which such a die set is mounted.

In this instance, each assembly is shown as comprising a cylindrical'bushing 13 rigidly; carried by and arising" from an opening formed in the die holder 11 of the die set The bushing provides an internal cylindrical bore and the groove 21, the ring or band 22 .is in a somewhat circumferentially contracted state. so that its expansive energy is directed outwardly on the ball elements 18a, causing the latter to be seated in the relatively restricted outer portions of the seats or openings 17d. This 'is done r so that the elements 18a will be maintained in'contact with the shouldered edge 20 with suflicientrfirmness'to' V sustain the weight of the retainer and to preventjits drop- 7 7 ping intotheilower part 'of'the bushing bore'14;

14 of uniform diameter throughout its length, the bore having machined: ground, hardened and/ or polished Wall surfaces held to close dimensional tolerances. Thernovable plate 15 of each assembly carries ta fixed,rigid, depending pin or 'post; 15 having cylindrical outerwall sur faces-of uniform diam'eter substantially throughout the As: the post '15 descends: firom its elevated position at the start of'itsworking stroke, the. same moves into pres v jsure-loadingcontact withf'the ball elements 18 disposed immediately below the elements 1811. -Since the elements 18 cannot move radially outwardly of the retainer after length thereof, these surfaces being heldwithi'n closefdi-j,

n ensional' limits byfmachining and otherwise finishing, and hardeni'ng the same to a true cylindrical contour.

Mounted for linear movement 'in each guide assembly the manner of theselernents.ltimibutfare cornined positively in their seats againstYsuch radial movement,and are, also, additionally' held byfpressing against the wall surface of the bore 14, it will betevident that the ball ele- 21 3 ,a tubular, sleeve-like, bearing retainer 16', the' latter f V having'accurately finished inner and outer cylindrical 7 surfaces of uniform diameterhardened, polished or otherwise treated after the manner of forming the complemental surfaces of the post and bearing members. Each i retainer is formed with a plurality of transverse relatively spaced openings (17 constituting seats for the rotatable retention of a plurality of ball-bearing elements'IS. The I: a

wall thickness of each retainer is less than the radial width of an annular space 19 formed between each interfitting pair of guide bushings and posts when the latter are disposed in relatively telescoped order Each bear i V 7 ing element, however, possesses a diameter slightly greater 7 than the radiaI width of the space'19 rec'eiving the same;

This enlarged diameter is important in the operationnof guide appliances of this character, in'that when a'post 15 descends so that" its lower end is' positioned jn'the upper part of the innep bore 20 of can associated retainer', 1 andzat theisame timeinthe-uppfer'part of the'bore 14 of 'Janfassociated guide bushing 13, certain oi the ball bear; f

i pthpost has reached itsffull upwardipositionof travel,- i 5 at which'time' the above-definedcycle may be repeated. Q 3

' ingielements'will be engaged by the'post and crowded thereby intoengagemjent with the inner bushing wall to 7 place the post-engaged ball elements of the sleeve under :compressive forces. The ball elements so engaged' are rotatei'with the result that the-retainer 'moves down wardly conconiit'antly with the descending post, buttat a lower rate of linear travel. juclrmotion is continued as v the ball elements areprogressivelyjengaged by the descending post, producing a positive guiding action where- V in lateralrnotionis eliminated andaccuracy thereby obe tained inpunch'and die'registry."

' and stationary members of the die setiwhic'h' members have been here shown as comprising the movablefpostflfi' and the stationary bushing 13; although this order might be reversed if desired: T

WhenIthe post '15- is elevatedto assume a startingposi tion, the lower iend 'thereof is"prferably positioned so g V ,mediately'- below the'eleme'nt's Q1819, thereby: placing: the

that it does, not confine one or-m'ore'bearings 18 by apply-1 i 1 i i a ing compressive forces' thereto. Undentheseiconditions I of relative release'and to prevent theretainer fromdrop; ping 'gravitationallyinto the bushing bore 14,, certain of V the bearings,18, those here shown at 18a, a-re disposed] in horizontaltorder forcontact withftlieiiuppcnfshoulder storming edge 26: of the bushing. The bearings ISa are I pressedoiltwardlyandradially ofethe retaineribody by; e

i lateral r novement in the'enlarged openings'tconstituting V the seats 17a. The relatively enlargedjinneiiendsw "of the' openings'17a -communicatewith'an ann'ulargroove" 21in which-'isjpositioned a split resilient' or, band" I L Another variation ,of thisiconstruction isfdisclosedj 5 V H Figs. ands5 vjwherein, the: annular groove 24, formedqf 1 in, the bottom portion "of the ,post:15:,' is provided withfa V shoulder 25 for engagenien'tj with the inner beveledtends' 'of a plurality: 'of radially positioned latchjmembers26.

'ments18 so engaged are positivel'y'rotated1and placed 20 under loading compression by the descending post. The positiverotation thus imparted to the compressively loadf' ed ball elements causes the retainer to descend and move simultaneously with the post'bnt'at a lower" rate of travel, thus overcoming the actionof the spring 22 in cau sing the ball elements 18a to move radially inwardly to clear 'the shoulder 20. 7

Under these conditions, the support of thefloating retainer no'longer depends on the engagement of the springpres-sed ball elements 18a in contacting the bushing shoulder or edge 20, but such supporting function is borne by the tight compression-producing forces which the descending post developsr'for application to the ball ele-,

ments 18 and the walls of the bore 14. The retainer isthus caused to travel in about one to'two ratiofwith" 'the post *as the latter moves either downwardly or up; Wardly on its working strokes, so that the spring-pressed' ball elements 182: donot again, support the retainer until "Q'Inthe form of the invention illustrated'in Fig.3; the

' same features of control and operation a re' esse'ntiallyr present, but in this form the ball elements shown tat- 18b, 'areflforced inwardly andradially of the reta ne 16 by V the action'of' the resilient; ring 'or-band 2}; In this constructio'n, the retainer i-ssupported -firorn the lower end of the post 1 5 when the latter occupies its elevated-position 1 through engagement with am -annular recess or' groove a 23 formed-.inand extending around the lower part of the V i post;- The openings 17b of the-"retainer '16 in this latter V form of my'i'nventio n are oppositely formedor disposed V; 'with respect to the openings 7170 so th atrtherelativelyr enlarged regions of the openings 17b'are disposed toward f the outside of'th'e retainer rather-3'thanthe inner side; 7

thereof, V V motion-disclosed in Fig. 3, when the post In th con descends'on its working stroke; the ballelernents 7 181) "are,

displaced outwardljfifthus releasing-the jassiociated re,

tain'er from itsassociation of suspendedsupport from f the lower end-of the post; However; at this-time the descending post engages 7 ball elements 18 disposed ime'ngag'ed elements 18 tinder compression-{and causing regulated'descent of the-retainriatla 'l'qwerirate of travel 'thanthe descending; post, as; previously-explained. when, [i the post returns to -its elevated position after completing,

its gcycle of -moveinent, the ball elements isb arel'again i seated in the'reces's or girooveg23to;supporttheretainer, 'or sleeve} f i I These member's-rarev slidably' mounted in the openings ment with the post groove 24 and its shoulder 25 by the spring ring 22, the latter being seated in'notches formed in the outer ends of the latch members. It will be evident that with the use of this construction, when the post descends on its working stroke, the engagement of the conical wall surfaces of the groove 24 with the inner ends of the latch members 26, results in outward radial movement of the latch members against the resistance of the spring ring 22. The sleeve is thus released for controlled downward movement with the post as the post engages the ball elements 18 to impart compressive loading thereto.

Through the use of the means described, or the equivalent thereof, the vertically movable'ball-bearing-carrying retainer or sleeve members of antifriction die set guide assemblies are positively supported or retained against movement in a predetermined positional relation to the associated movable and stationary members of the guide assembly. Further, the construction of the positioning means of the present invention is such that the retainersupporting function thereof is released or removed automatically with the descent of the moving member of the assembly on its working stroke, so that the retainer member will be caused positively to move linearly with the associated movable member at a controlled relative rate of travel throughout the full working stroke of said movable member. When the latter returns to its normal or starting position the retainer member returns with it andoccupies a predetermined positional relationship therewith. At this time the ball elements of the retainer member are relieved of the compressive forces resulting from their simultaneous contact with contiguous surfaces of the movable and stationary guide members of the assembly. The telescopic relation between the guide members during a working stroke and the interposition of the retainer member with its ball ele ments, enables the retainer member to be movably positioned in its established relation with said guide members. The retainer, it will be observed, moves in unison with an associated post when the bearing elements are unloaded, but when said elements are loaded or pressure confined between the post and bushing, the postcarried retainer holding means arereleased to admit of independent relative movement of the retainer with respect to the post, or other movable member normally carrying the same.

Various other modifications maybe made within the scope of the following claims, including the employment of posts of square or polygonal cross-sectional formation and roller bearing elements rather than ball bearing elements. Also, dual walls of sheet metal may be used in the formation of the retainers rather than the solid wall types shown.

I claim:

1. Guide mechanism for the die sets of presses, comprising: a stationary member; a movable member disposed in coaxial order with the stationary member and movable longitudinally into and out of interfitting relationship therewith; a retaining sleeve occupying an annular space formed between said memberswhen the latter are disposed in interfitting order; ball elements rotatably movable in socket-forming openings provided therefor in the wall of said sleeve and having antifriction guiding engagement with the adjacent wall surfaces of said members defining said space, said elements when in simultaneous contact with said member surfaces being placed under compression loading whereby to cause said sleeve to travel linearly concomitantly with and at a controlled rate relative to that of the associated movable guide member; and means for positively supporting said sleeve in a fixed predetermined positional order with respect to said movable and stationary guide members when the movable member assumes a position removing the same from compressive engagement with the ball elements.

pliances of the type embodying interfitting stationary and movable guide members. there being a floating ballbearing retaining sleeve movably interposed between said members, the bearings of said sleeve receiving compressive loading through opposing simultaneous contact with said members during working mov'ement thereof; and retractable latch means for supporting the sleeve of said appliance in a definite positional order in relation .to said members when support normally afforded said sleeve through compressive loading of said bearings is removed as a result of change in relative positions of said members. 3. Alignment maintaining antifriction guide means for die sets, comprising: relatively movable axially arranged socket and post members; a sleeve formed for movable interposition between said socket and post members when the latter are disposed in interfitting order; ball bearings rotatably positioned in spaced seat-forming openings provided therefor in the cylindrical wall of said sleeve, said bearings being of uniform diameter and arranged in said sleeve openings to project equidistantly beyond the inner and outer wall surfaces of the sleeve for simultaneous compressive contact with adjacent wall surfaces of said socket and post members during interfitting longitudinal movement of one of said last-named members with respect to the other, whereby to produce movement of the sleeve in a linear direction concomitantly with relative movement between said members; and means operative when said members attain relative positions in which the bearings of said sleeve are relieved of sustaining compressive forces produced by simultaneous contact of said bearings with said members to effect the support of said sleeve in a definite operational position relative to said members.

4. Alignment maintaining antifriction guide means for die sets, comprising: relatively stationary and movable axially arranged socket and post members; a sleeve positioned for longitudinal movement between the post and sleeve members, said sleeve being formed with spaced openings for the rotatable reception of ball elements,

a the latter being of such diameter as to engage simultane- 5. ,Die set aligning and guiding means as defined in claim 4, and wherein said latching means are disposed I radially of the guide means and have releasable engagement with the movable guide member when the latter is advanced on an operating stroke.

6. Die set aligning and guiding means as defined in claim 4, and wherein said latching means comprises at least one of said ball elements positioned in the opening provided therefor in said sleeve for radial movement; and resilient means positively displacing the latching ball element radially to maintain the same in a position in which it protrudes yieldably on one side of the sleeve to a greater extent than the remaining ball elements, said protruding ball element having releasable sleeve-supporting contact with one of said guide members when the latter occupy relative positions in which said ball elements are relieved of compressive loading.

7. Die set aligning and guiding means as defined in and by claim 4, and wherein said latching means includes in said sleeve an enlarged seating opening for the reception of at least one of said ball elements, said seating 7 "7 sleeve t i gre erextent t an rem ining. ball ele 'when the post and; socket members occupying'relqtiye positions in whicht s aid sleeve-c arried ball elements. erre-v relieved of cornressive loading; and resilient means 'co '7 operative Wlih; theprbtruding ball elementto maintain the; same,;intheabsence of preponderant opposing forces in;its position'of'rnaximum protrusion inwhich said element engages one of said membersin retractable sleeves n'pportingIelation, i i

' 8-. The/combination with;antifrietion die set guiding and'ali gn ing means, said means being o'f the type; em

bodyin'g ,zi;. bnshingmember carried by one of the plates of a die setand having a bore arranged to receive axially a post member earried byanotl le die set plate, said membersibeingjrelatively movable to cau se the post member.

to m oyeintoi and out of the-bore of said bushing member there being a floating sleeve arranged for relatiye move-. ment longitudinallyand axially. of and between said member, the cylindrical wall of said sleeve being formed with se ating iogening s for the receptionhof a' plurality ing movements of saidmembersb No references cited.

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