US2846278A

US2846278A - Positioning means for guide assemblies of punch press die sets

Info

Publication number: US2846278A
Application number: US545649A
Authority: US
Inventors: William J Blazek
Original assignee: LEMPCO PRODUCTS Inc
Current assignee: LEMPCO PRODUCTS Inc
Priority date: 1955-11-08
Filing date: 1955-11-08
Publication date: 1958-08-05
Anticipated expiration: 1975-08-05

Description

Aug. 5, 1958 w. J. BLAZEK 2,846,278

POSITIONING MEANS FOR GUIDE ASSEMBLIES OF PUNCH PRESS DIE SETS Filed Nov. 8, 1955 3 Sheets-Sheet 1 WJBZazek ATTORNEY g- 5, 1958 w. J. BLAZEK 2,846,278 POSITIONING MEANS FOR GUIDE AS BLIES OF PUNCH PRESS DIE SET Filed Nov. 8, 1955 5 Sheets-Sheet 3 INVENTOR W J Blaze/c ATTORNEY PDSITIONING MEANS FUR Gilmll ASSEMBLIES F PUNCH PREES DEE SETS William J. Blazek, New Lexington, Ohio, assignor to Lfierongco Products, inc, Eedford, Ghio, a corporation 0 Application November 8, 1955, Serial No. 545,649

6 Claims. (Cl. ENDS-6) This invention relates to punch press die sets, and more particularly to registry-maintaining, antifriction, guide devices for use in connection with such die sets.

The present invention aims primarily to provide position-maintaining means for the movable bearing retainers of antifriction die set guiding and aligning devices. Such devices are formed customarily so that a punch-carrying movable holder of a die set is provided with guide posts which are axially receivable for relative longitudinal movement in longitudinal holes or bores of stationary bushings carried by a complemental die holder of the set. In association with these parts, tubular ball-bearing retainers of the movable floating type surround the posts and are arranged and held so that ball elements carried thereby are disposed in annular receiving spaces provided between the outer wall surfaces of the posts and the adjacent inner wall surfaces of the bushing bores, the ball elements being disposed in simultaneous contact with post and bushing surfaces.

This construction is such as to provide for accurately guided and confined reciprocatory movement on the part of the die and punch-supporting holders of a die set. The construction eliminates undesired lateral motion between parts and enables the punch and die members of the set to be brought into and out of true forming contact with work pieces positioned between the same in the press. Such alignment of the relatively movable die and punch members is made possible through the use of said ball element guide devices, and results in prolonging the working life of the punch and die members, as well as enabling the same to produce more rapidly and accurately forming operations on work pieces.

Such pressure-loaded ball-bearing guiding devices for die sets are disclosed, for example, in the prior patent to Conner No. 2,422,774, granted June 24, 1947. in assembling these devices, however, it is important that the ball-bearing retainers of each complete guide assembly be inserted in the bores or openings formed therefor provided in associated bushings and that at such time the retainers be disposed in a definitely positioned manner on the lower ends of the associated posts. This condition is present particularly when the guide assembly is of the type in which the posts thereof move vertically into and out of the upper open ends of the bushing bores.

In this type of die set guide apparatus, upon the descent of the posts into the open upper ends of the bushing bores, the outer cylindrical surfaces of the posts engage the ball elements of the retainers and force the same against the complemental inner cylindrical walls of associated bushing bores or holes. Since the diameter of each ball element of the beraing retainers is such that it exceeds slightly s 2,3452% Patented Aug. 5, 1958 portant, therefore, in the proper functioning of each guide that the floating bearing-retainers move at a controlled rate concomitantly with the posts in providing antifriction holder guidance, whereby to minimize wear and maintain positive alignment between the relatively movable die set parts.

Because of the floating characteristics of the ballbearing retainers, that is, the absence of any direct physical connection between the retainers and associated posts and bushings, it has been somewhat diflicult for machinists to so assemble each guide and dispose the retainers so that the bearing elements thereof will maintain their pre-loaded positions throughout fullback and forth stroke movements of the guide assembly. If, for example, a retainer should drop and remain in the bottom of the bore of an associated bushing, or otherwise fail to move with its reciprocatory post, excessive friction, part wear and looseness would develop rapidly and impairment and loss of guiding function of the guide assembly caused to take place.

The present invention, therefore, has for one of its primary objects to provide an improved positioning means for use in association with such antifriction guide appliances for die sets, whereby in assembling the parts thereof it is necessary, as a result of the presence of the positioning means, to arrange the parts of the guide assembly in their proper or required relative order in producing the operative assembly.

A further object is to provide antifriction guide appliances for machine tool die sets of the type utilizing floating bearing retainers of the tubular open-ended type and which are interposed, when in use, between the guide posts and bushings of the die sets, and to provide in connection with such appliances novel supporting and positioning means for maintaining the retainers operatively interposed between the posts and bushings in all their working positions, said positioning means serving during active operation thereof to preclude movement on the part of said retainers to positions in which all the antifriction bearing elements positioned therein would be removed from simultaneous pressure engagement with contiguous surfaces of associated posts and bushings.

An additional object is to provide retainer-positioning means of this character which is so formed that it will function to support in definite positions the retainers on their associated posts when the latter are fully elevated and removed from bushing bores, so that the retainers therein will be held automatically in proper positions and adapted, when the posts are lowered for insertion in the bushings, to maintain the ball elements thereof under pressure loading in all operative or working positions of the die set.

These and other objects of my invention will become more apparent from the following description of certain embodiments thereof, the latter being illustrated by the accompanying drawings forming a part of this specification.

In the drawing:

Fig. 1 is a vertical sectional view taken through an antifriction guide assembly for punch press die sets, and disclosing the same equipped with the bearing retainer positioning appliance of the present invention;

Fig. 2 is a similar view of the guide assembly and disclosing the relative positions of the movable and stationary parts thereof when in a lowered or telescoped position;

Fig. 3 is a transverse horizontal sectional view taken on the plane indicated by the line 33 of Fig. 2;

Fig. 4 is a detail perspective view of a tubular bearing retainer utilized in the apparatus of the present invention;

Fig. 5 is an enlarged transverse horizontal sectional view disclosing one of the antifriction ball elements in 3 its seatedposition in the bearing retainer of the guide assembly, and disclosing the relationship of the ball element with the outer surface of the guide post and the associated inner surface of the bushing of the assembly;

Fig. 6 is a detail vertical sectional view disclosing a modified form of the invention,-wherein the guide bushing is carried by the movable. part of the die set and disclosmg the positioning appliance of the present'invention as supported from the movable bushing;

Fig. 7 is a similar view disclosing still another modified form of the invention in which thebushing of the guide assembly is also carried'by a movable partof the die set, the post of the assembly being shown as stationarily mounted;

Fig. 8 is a vertical sectional view disclosinga further modified formof the invention in which the bearing retainer of the guide assembly is supported from the movable pin or post of the die set by a positioning appliance comprising spring-pressed r-adiallydirected plungers;

Fig. 9 discloses in vertical cross section a still further modified form of the invention in which the positioning means are associated with a movablepost and include a frangible dowel element;

Fig. 10 is a similar view showing a fabricatedtype of bearing retainer;

Fig. 11 is a vertical sectional view of a modified form of the invention in which the guide: assembly includes posts, bushings and retainers of polygonal cross sectional formation;

Fig. 12 is a horizontal sectional view on the

line

12,12 of Fig. 11.

Referring more particularly to the drawings, the die set, as here shown, comprises a movable punch-holder 10 and a stationary die-holder 11. It will be understood that an appropriate punch and die construction, not shown, is adapted to be suitably clamped to these holders and, through relative movement therebetween, brought into and out of forming engagement with Work pieces placed between the same. In providing means for maintaining the alignment of the holders 10 and 11 during relative movement thereof, so that the punch and die devices carried thereby will be brought into precise registry during work-forming operations, there is provided between said holders a plurality of guide assemblies, as indicated at A.

As shown inFigs. 1 to 5, inclusive, each of these assemblies includes a cylindrical post 12 having a machined and hardened outer surface which possesses a uniform diameter throughout the length thereof, the upper .end of said post being pressed or otherwise retained in an opening 13 provided for the reception thereof in the holder 10. Likewise, the die holder 11 includes an upstanding tubular bushing 14 having an axial hole or bore 15 of uniform diameter throughout its length, the walls of the bore being machined, hardened or otherwise finished to precise dimensions, after the manner of the exterior walls of the pin or post 12. When the punch holder 10 moves downwardly, so that the postenters the associated bushing bore 15 .for coaxial longitudinal movement therein, an annular space 16 is produced between the outer surfaces of the post 12 and the inner surfaces of said bushing bore 15.

Received in this space is a floating, tubular, ballbearing retainer 17, the latter havingcylindrical, accurately formed, inner and outer surfaces between whichand in the wall of the bushing there extendtransverse horizontal openings 18. These openings include seats for .the reception and retention of antifriction devices, which, as here shown, are in the form of ball bearings 19, although other types of antifriction bearings may be used when the cross-sectional formation of the .posts and bushings are accordingly modified. It will be noted from Fig. 5 that the diameter of each bearing 19 is such .that when held by the .retainer the same will project beyond the -,innet and outer vertically disposed cylindrical surfaces of 4 the retainer. Thus, as the punch plate or holder is lowered, the bearing elements of the retainer will be brought into pressure-confined engagement with the wall surfaces defining the bore 15 of the bushing 14 and the complemental outer surfaces of the post 12.

With the parts of the guide assembly arranged as shown in Fig. 1, wherein is illustrated the normal positions of the members of the die set at the beginning of the downward working stroke of the plate 10, it will be observed that the retainer 17 has about one-half of its total length positioned in the upper end of the bore 15. Also, in Fig. 1, the extreme lower end of the post 12 is shown as having just entered and disposed somewhat below the horizontal plane defining the upper edge of the bushing 14. With the parts in thisposition the ball hearing or bearings 19, confined between and in simultaneous contact with the coaxial telescoping portions of the post 12 and the bushing 14, are brought under forces of compression. Upon downward movement of the post these forces produce positive turning movement of the ball elements 19 which are engaged simultaneously byboth post and bushing, so that the retainer 17 is caused to move downwardly concomitantly with the post 12 at a controlled but somewhat reduced or lowered rate of linear travel. 'Due' to the pressure loading of the ball bearings 19, and as the descent of the post 12 continues, true vertical movement takes place with an absence of lateral relative motion on the part of the elements of the assembly, so that the dies carriedby the holders 10 and 11 are maintained in proper alignment and registry.

When the holder 10 and its associated post or posts 12 reach their positions of maximum descent, as shown in Fig. 2, the lower end of the pin or post 12 will be disposed somewhat below the lower edge of the retainer 17. In this latter position, the retainer will have its lower edge disposed above in spaced relation from the bottom surface 20 of the bore 15, the retainer being held against dropping to said bottom surface as a result of the compressive loading of the ball-bearing elements 19. When the post 12 is raised, the retainer moves with it .until approximately the positions indicated in Fig. 1 are again reached, thus completing the cycle of operation.

In connection with this assembly and installationv thereof, certain diificulties have been encountered in .the

matter of correctly ascertaining the required relative.ar-.

rangement of the bearing retainers in relation, to the movable and stationary parts of the guideasseniblye In order to positively establish such relation, 'theinvention provides an improved positioning appliance,,indicated.in its entirety at 21, for locating and supporting theretainer in predetermined relation to the associated parts of the die set on which the appliance is carried. In the-formofthe invention illustrated in Figs. 1 and 2, the'lowerporden of the post is formed, as shown in Figs. land2, with an axial bore 22, the latter having a closed innerend and its outer end threaded for the reception of tubular bushing 23. The bushing slidably receives-the indexing device which includes a stem 24'having a disk-likehead 25 fastened to or formed with its lower end and a smaller enlargement 25a on its upper end.

When the movable posts 12 are disposed well above the horizontal plane defining the top of the bushings 14, the retainers 17 are first positioned around said posts, the indexing devices 21 being thereafter joined with the posts by threading the bushings 23 carrying the same into the lower end of the pin bores 22. In this manner, the retainers will be permitted to move downwardly on the head disks 25 of the appliances and assume approximately the position of operation disclosed in Fig. 1, which shows the positions of the guide parts at the upper end of the working stroke of the press. As so positioned, the press and die setmay be operated under normal conditions of reciprocation. When the parts of the guide assembly reach-their extreme telescopedor lowered positions, as in Fig. 2, the heads 25 of the indexing appliances rest loosely or freely on the bottom surfaces 20 of the bores 15, with the stems 24- of said appliances projecting into the bores 22..

In this connection, it will be observed that the indexing or positioning appliances are carried by the movable parts of the guide assembly, which in Fig. l constitutes the posts 12, and is adapted to have supporting and locating engagement with the retainers 17. This is done in order to actively support the retainers when said posts are elevated and with the ball elements of the retainers removed from pressure contact with contiguous post and bushing surfaces. The appliance, however, is relieved of its retainer-supporting and locating function when the ball elements 19 are in compressive pressure-loaded contact with adjoining bearing and post walls of the guide assembly, as will be readily understood.

The construction is, of course, susceptible to certain mechanical variation. For instance, as shown in Fig. 6, the movable punch holder a, instead of carrying a post carries a bushing, shown at Ma, for movement in unison therewith. The post 12a in this instance is stationarily mounted in connection with the die holder 11a. The positioning appliance 21a, employed for determining the positions of the retainer 17a, comprises, as here illustrated, a hollow circular collar or frame 26 which, at its upper end, is formed with an internal flange 2'7 surrounding the bearing or bushing 14a and normally resting upon an annular seating rib 23 formed with and projecting exteriorly from the outer wall surfaces of the bushing 14a. The lower part of the collar 26 includes an inturned flange 29 which is extended to engage with the lower edge of the retainer 17a, whereby to locate the positions of said retainer with relation to the movable hearing or bushing 14a in providing for the requisite location of the parts prior to pressure loading of the ball bearings 19a.

In the form of the invention illustrated in Fig. 7, the holder 10!) also carries a movable hearing or bushing 1417. In this instance, the lower open portion of the bearing or bushing 14b has its wall structure formed with an opening 30 in which is positioned a fixed stud of frangible material and shown at 31. The inner end of this stud is received in a longitudinal slot or recess 32 formed in the outer wall of the bearing retainer shown at 17b, and which admits of relative longitudinal movement between the bushing and sleeve.

In the assembly disclosed in Fig. 8, the post 12c is rigidly carried by the movable punch holder 100. Toward its lower end, the post 120 is formed with a transversely extending opening 33 in which is positioned a pair of transversely aligned dowels 34 which are normally forced apart by an intervening coil spring, shown at 35, the outer ends of the dowels being receivable in an annular groove or corresponding depression 36 formed in the inner wall of the retainer 170. As the post 12c moves longitudinally relative to the retainer, the dowels 34 move inwardly of the opening 33, against the resistance of the spring 35, to compensate for the inequalities of linear motion of the retainer and post.

Another variant of the present invention is illustrated in Fig. 9, wherein the figure depicts a post 12d carried by the movable membed 16d, the post being provided contiguous to its lower end with a transverse opening 37 which is adapted to align with one or more openings 38 formed in the upper edge portion of a bearing retainer 17d. A frangible dowel pin 39 may be positioned in the aligned

openings

37 and 38, as shown in Fig. 9, in locating and retaining the retainer in its proper position on the post 12d, but which parts or shears when the poe and retiner move at different rates of linear travel.

As shown in Fig. 10, the bearing retainer 17@ instead of being formed from a tube having a solid wall is fabricated to include lightweight inner and outer concentrically disposed, relatively spaced

walls

40 and 41, respectively. The walls are united at their ends by being spot welded or otherwise joined with separating rings 42. In this instance, one of the rings carries a positioning pin 39a which is adapted to be received in a transverse opening 37:: formed in an associated post Me. The

walls

40 and 41 at appropriately spaced intervals are formed with transversely aligned openings 18a having opposite tapering or coined ball-seating surfaces 43, which allow maximum protrusion of the spherical bearing elements 1? without sacrifice in the thickness of the retainer walls.

In Figs. 11 and 12, the posts 12], the bores 15 of the bushings l4 and the retainers 17 are substantially square in cross section or of other polygonal form to ad mit of the employment of roller-type bearing elements 19 as well as the spherical type previously described. The positioning means 241 and 25 function in the same manner in this guide construction as the corresponding means of Fig. 1.

In summary, it will be observed that the present invention provides improved indexing appliances which may be readily applied to antifriction guide assemblies of punch press die sets for part location-determining purposes. The construction of the appliances is essentially simple and effective and the same will interfere with the normal functioning of the guide means during operation of an associated press. However, the indexing device does provide for, and in fact makes mandatory, that there shall be proper positioning of the bearing retainers of such assemblies during initial grouping of the elements thereof, so that through such indexing means predetermined relative motion is caused to take place between the post, bearing and retainer members, whereby to minimize wear and secure long operating life on the part of such devices and associated parts of die sets.

I claim:

1. In a die set embodying a pair of relatively vertically movable upper and lower die-supporting sections, relatively telescoping upper and lower post and bushing members carried respectively by said die-supporting sections, said post and bushing members being movable vertically relative to one another, and a vertically arranged tubular bearing retainer normally positioned between said post and bushing members and including a plurality of antifriction rolling elements extending inwardly and outwardly from the walls of said retainer for rolling engagement with opposed surfaces of said post and bushing members; that improvement which comprises means slidably carried by the upper of said post and bushing members in depending relation thereto and being engageable with the lower end portion of said bearing retainer to hold the latter in predetermined depending relation to the upper of said post and bushing members when said post and bushing members are removed from one another.

2. A die set as defined in claim 1, wherein the post constitutes the upper of said post and bushing members and is formed at the lower end with an axial bore, and wherein said last-named means comprises a stern extending downwardly and outwardly from the lower end of said post and slidably retained in the axial bore of said post, and a head carried on the outer end of said stem and extending laterally outwardly beyond the sides of said post to engage and support the lower end portion of said retainer.

3. A die set as defined in claim 1, wherein the bushing constitutes the upper of said post and bushing members, and wherein said last-named means comprises a hollow frame slidably retained on said bushing and extending downwardly therefrom and having a laterally inturned flange to engage and support the lower end portion of said retainer.

4. In a die set embodying vertically arranged, relatively telescoping but removable post and bushing members and a vertically arranged hearing-retaining sleeve arranged to fit between said post and bushing members when the latter occupy relatively telescoped positions;

that improvement which comprises means carried-by one of saidmembers for limited axial sliding movement relative'thereto for holding said sleeve in a given indexed position relative to said last-named member when said post and bushing members are removed from one another, said means being engageable with the lower end portion ofusaid sleeve and providing for vertical reciprocating movementvof said sleeve between said post and bushing members when the latter are positioned in relatively telescoping arrangement.

5. A dieset as defined in claim 4, wherein said post member is formed with an axial bore, and said lastnamed means comprises a stem extending outwardly from the lower end of said post and slidably retained in the axial bore thereof, and a head carried on the outer 15 2, 22,7 5

end of said stem andextending laterally outwardly beyond the sides of said postto engage and support the lower end portion of said sleeve when said post member is removed from said bushing member. 7

6. A die set as defined in claim 4, wherein said bushing member is provided with an outwardly extending seating rib, and said last-named means comprises a hollow frame slidably retained on said bushing by said seating rib and having a laterally inturned flange to engage and supportvthe lower end portion of said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS Conner June 24, 1947 Conner June 24, 1947