US1562988A - Power press - Google Patents

Description

Npv. 24, 1925- 1,562,988

J- NELSON POWER P RESS Filed NOV. 1922 4 Shoots-Sheet 1 [Kw/armor;

{NovL 34, 1925.

J. NELSON 7 POWER PRESS Filed Nov, 2. 1922 4 Sheets-Sheet z Ewan-ton kn J? on, 0% m,

Nov. 24, 1925- 1 1,562,988

J. NELSON POWER PRESS Filed Nov. 2. 1922 4 Sheets-Shut 3 fie Pas ed N... 24, 1925. i

" tum-.1 's'rA'r s i 1,562,988- PATENT. orrlcs.

Joan NELSON, or cnrcneo, rumors, ASSIGNOR- rdmnonnrrn r001. & MANUFAC .TURING COMPANY,- or cnrcneo, rumors, A conronn'rron or rumors.

rower.

PRESS.

Application filed November 2, 1922. Serial Ko. 598,698.

To all whom; it may concern:

Be it known that I, JOHN NELSON, a citizen of the United States, and a resident of Chicago, Cook County, and State of Illinois, have invented certain new and useful Tine provements in Power Presses, of-which the. following is declared to be a full, clear, and exact description.

This invention relates to power presses and one of its principal objects is to provide pressure operated balancing means whereby the usual heavy fly wheel nay be dispensed with. Another object is to provide pressure operated balancing means for the ram, which will enable the press to be built with a lighter crank shaft than is required for a press of the same capacity and power as one equipped withthe balancing means embodying the present invention. Another object is to provide means for storing up energy, (independent of the fly wheel) onthe up stroke of the ram. Another object is to provide means for storing up energy on the up stroke of the ram, (independent of the fly wheel), and for delivering said stored up energy to the ram on its down stroke, in lines parallel with the direction of movement of the ram. Another object is to provide means for storing up energy on the up stroke of the ram, (independent of the fly wheel), and for utilizing said stored up energy in conjunction with the usual crank shaft of the press.

This invention has been designed for use in connection with presses which employ draw-ring or blank holding mechanism'to apply pressure to the marginal portions of the blank while the press is doing its work, and one of the objects of the present invention-is to provide improved means for operating the draw-ring. In certain classes of work it is important that greater pressure be applied to the draw-ring at certain places than at others, and one of the objects of this invention is to provide means for producing additional pressure uponthe drawring at anyone or more various places thereon as is desired. Other objects and advantages will occur in the course of this specification, and with all of said objects and advantages inview, this invention consists in the several novel features hereinafter fully set forth and more particularly defined in the appended claims.

The invention is clearly illustrated in the 65 accompanying drawings, in which:

Fig. l is a side elevation, partly broken out, of a power press embodying a simple form of the present invention, showing the ram at the top of its up stroke; Fig. l is a diagrammatic view of compressed air tanks used in connection with the press; Fig. 2 is a vertical cross section of the press taken on the line 22 of Fig. 1, showing the ram at the bottom of the down stroke;

Fig. 3 is a view, partly in plan and partly in horizontal section, the line of section being indicated at 33 in Fig. 1; Fig. 4 is a View, partly in under plan and partly in horizontal section, the line of section being indicated at 44 in Fig. 1; Fig. 5 is a detail, vertical section of certain members of the draw-ring actuating means, the line of section being indicatedat 5-5 in Fig. 3; Fig. 6 is a view similarto Fig. 5 but showing the parts in a different position; Fig. 7 is a detail, horizontal section taken on the line 7-7 of Fig. 5; Fig. 8 is a detail, horizontal section taken on the line 8-8 of Fig. 5'; Fig. 9 is a vertical longitudinal section through a fragment of'a die press illustrat ing'a modified form of draw-ring mechanism.

Referi'ng first to Figs. 1 to 8, inclusive,

which illustrate the preferred embodiment of the invention, the reference character 10 designates thebase, 11 the bed, 12- the bolster and 13 the upright side frame members of a power press of ordinary and well known construct-ion. Resting upon and secured to the bolster, is the female die 14, and cooperating therewith is the punch or-male die 15, which is secured to the ram 16 by bolts as is well understoed. The ram 16 is guided upon the side frame members 13 to move lengthwise thereof. Connectin rods 17 connect the ram 16 withthe cradks' 18 of the crank shaft 19, as is well understood, and the crank shaft is journaled in bearing boxes 20 formed in the upper ends of the-side frame members 13. A back geared press is illustrated in thedrawings, and as shown, the

crank shaft 19, is driven from a main drive I i shaft 21, by a pinion 22 on the main drive shaft-.21, and a. gear wheel 23 on'the crank 1 5 shaft, which gear wheel meshes with said pinion. Clutch mechanism ,(not shown) may be provided, as is customary for startabsorbed by the pressure operated balancing means employed in connection therewith.

It is also to be observed that the usual heavy fly wheel or balance wheel is dispensed with. Otherwise, the general construction of the press proper is practically similar to that of the ordinary and well known die presses.

Secured to the arch bar 24 is a cylinder 1 25, closed at the top by a cylinder head 26 and open at the bottom. In said cylinder 25 is apiston 27, which is connected to the ram 16 by pistons rods 28, there being at least one piston rod on each side of the crank shaft, extending through lugs 29 formed upon an upwardly extending rib portion 30' of the ram. Lock nuts 31 threaded on the lower ends of said piston rods 28, on the opposite sides of the said lugs 29, rigidly connect the piston rods 28 with the ram. On the up stroke of the ram, the piston 27 compresses the air in the cylinder 25, and on the down stroke of the piston, the compressed air acts in conjunction with the crank shaft in forcing the piston down during its working stroke. It will also be observed that the power derived from the compressed air is exerted through the piston rods 28, in lines parallel with the direction of movement of the ram.

It is preferred to maintain a constant sup sure may be had in'the reservoir and cylinder 25, with this arrangement, so that a practically uniform pressure may be had upon the piston 27 at all times. Moreover, with the use of the air pressure, as an aid 'to the crank shaft, less power need be employed for driving said crank shaft, and because of the application of the power from I the cylinder to the ram on lines parallel with the movement of the ram, the crank shaft may be made of lighter construction than usual in presses of this kind.

The invention has been shown in connection with a press employed in'drawing metal and as is customary, a draw-ring 34 is em ployed, which draw-ring conforms generally to the shape of the die 14, and saiddraw-ring is bolted or otherwise secured to' a draw-ring plate 35. The draw-ring 34 and draw-ring plate 35 have openings 34" therethrough, for the punch on d1e 15. The draw-ring plate 35 is carried by a pluralit of stems or -rods 36, which have. reduce portions 36 that extend through the draw-ring plate 35, and are secured thereto by nuts 36, threaded on the upon their upper ends. When in the position seen in Fig. 1, the pistons or plungers 38 rest upon the upper face of the ram 16 and support the draw-ring late and draw-' ring above the die 14 throng the instrumentality of the stems or rods 36. 4

The pistons 38 are contained in cylinders 39, bolted orotherwise secured to the ram 33, and located in each cylinder, above the piston 38 is a stati'onarily supported circular or disk like block 40, that forms the upper head of the cylinder 39. Said stationary heads 40 are supported by, and rigidly fastened-to head supporting members 41 which are shown in the formof tubular members that are rigidly connected with the arch bar 24 and project down therefrom. As shown, the ,upperends of the tubular members are reduced to provide shoulders that bear against the under sides and have pistons or plungers 38 secured of the arch bar, and threaded on the upper ends of said tubular members are nuts 42, that bear against the upper side of the arch bar. A regulatablc and substantially constant supply of compressed air is maintained in the cylinders 39 between the heads 40 and pistons 38 and for this purpose an air reservoir 43 is provided which communicates with a pipe 43 and branches 43* that lead into'the upper ends of said tubular head supporting members 41.. It will be observed that by reason of the air pressure on the tops of the pistons 38, the draw-ring, when it is lowered into contact with the wprk, is held in pressing contact therewith, which pressure is maintained substantially constant during the time that the punch .or die 15 is performing its work. i

In the work of drawing certain shapes, it is sometimes necessary to place greater pressure upon certain parts of the marginal portions of the blank than upon others so' as to prevent those portiorrsof the blank from being drawn down out of 'sha e, and improved means have been provi edfor applying additional pressure at a plurality pressure devices are employed.

duced portions 46 which extend through the draw-ring plate and have nuts 46* threaded upon their lower threaded ends. The cylinders 44 contain wateig'oil or other liquid-above'the pistons 45, and regulatable nieans are provided for affording restricted or unrestricteddischarge passages from the cylinders 44 whereby when pressure is applied to the liquid contents of the cylinders containing the restricted discharge passages, said contents may escape comparatively slowly, and at a pre-determined flow so as to maintain a substantially constant pressure against the pistons 45, there being means for permitting the liquid to freely reenter the cylinders upon the outward strokes of the pistons. In the embodiment of the invention illustrated, each cylinder 44 has a partition or a head 46 at its upper end, in which is one or more ports 47 through which the liquid contents may pass in either direction. These ports are shown in arcuate form'in Fig. 7. Below eachhead or partition 46 1S a valve member, here shown in the form of a disk 48, (see Fig. 8)

which also is provided with arcuate ports 49, which 111.9118 position may coincide with the ports of the head or partition 46, to.

obtain a discharge port of maxmum area, but by turning the valve disk 48, the solid portions thereof may be caused to overlap the ports 47 of, the head 46 so as to decrease the area of said ports 47 to any degree desired, thereby decreasing the size of the discharge orifice or orifices from the cylin.

1 der 44, and determining the amount of pressure on the piston in the cylinder. As shown, each valve disk 48 is mounted upon a valve stem 50 which extends up through a central orifice in the head 46 and is connected to a hand lever 51 by means of which the valve disk 48 may be turned to regulate the area of the discharge orifices. Upon the upper end of the valve stem 50 is secured a sleeve 52 by a pin or otherwise, and a stem 53, secured to the hand lever 51, enters said sleeve 52 and has a sliding connection there with, but is non-rotatively connected thereto, as for instance, by a pin 54 that is secured in the stem and-enters vertical slots in the sleeve 52. The valve disk 48 normally seats against the lower face of the head 46 and it held inseating engagement therewith by a coiled compression spring 56 which is interposed between the upper face of the head 46 and the lower end of the sleeve 52. The upper end of the stem 53 is mountedin a bearing 57 supported by arms 58 that extend from the wall 59 of a chamber above the cylinder 44 into which the liquid is-forced by the action of the piston 45, and said Wall 59 may, if desired, be a continuation of I the wall of the cylinder- 44. For holding the head lever 51 at any pie-determined position, a tooth segmental rack (30 may be provided upon the upper end of the annular wall 59 with which engages a tooth (31 on the hand lever.

In the operation of the power press described, a metal blank indicated at A n Fig. 2 is placed upon the lower die 14, while the ram 16 is at the top of its up stroke. The draw-ring 34 is now suspendedfrom the rain, and the pistons 38 that carry the draw.- ring plate, ders 39. As the crank shaft 19 is revolved, the ram 16 is moved downward, carrying before it the draw-ring 34, and the air pressure upon the piston 27 in the cylinder 25 cooperates with the crank shaft, to apply force to the punch or die 15 during the working stroke 'of the press. Before the punch engages the blank, the draw-ring has come into contact with the marginal portions thereof. as seen in Fig. 2, and is thereupon held if: pressing engagement with the blank by the action of the compressed air in the cylinders. 39 on the tops of the pistons 38. As the ram 16 continues its downward working stroke,

above are under pressure in the cylinand draw-ring 34. The pressure on the.

draw-ring remains substantially constant punch or die 15 is the blank. I

During the up stroke of the ram, the punch or die 15 is raised, and as soon as the ramenperforming its work on gages the lower faces of the pistons 38, it

lifts said pistons, and therewith the draw ring plate, and draw-ring, thereby raising it above the lower die 14. \Vhen the auxiliary or hydraulic pressure devices are used, or when one or more of them is used for ekerting greater pressure upon the blank at certain'places thereon, the

during the entire interval of time that the valve disk 48 of each working cylinder 44,

which is to be used, is set to regulate the area of the discharge orifices of that cylinder.

Duringthe first portion of the down stroke of the ram, the pistons 45in all. ofthe cylinof the rods 36*.

ders 44 travel down with the ram, and cylinders, but as soon as the d raw-ring encounters the blank, the movement of the pistons is arrested although the cylinders 44 continue their downward movement during the remainder of the down stroke. The result is that the liquid in the working cylinders 44 is displaced slowly through the restricted ports therein, and'pressure is thereby put upon the tops of the pistons -15 of said working cylinders, whereby additional pressure is produced upon the blank under said working cylinders. Those portions of the blank are thereby held more firmly between the drawring and lower die than other portions of the blank. This pressure upon the blank is maintained constantly until the ram reaches the lower end of its down stroke and on the up stroke of the ram the cylinders 44 are lifted with .the rain, thereby increasing the distance between the pistons 45 and heads 46, whereupon, the valve disks '48 are unseated, ermitting the liquid to rapidly reenter the lnteriors of the pistons 44. It is to be understood that the chambers above the pistons 44 should be of suflicient capacity to contain all of the liquid which is displaced in the associated cylinder 44.

In the modified form of the invention illustrated in Fig. 9, in place of using a fluid for placing pressure upon the draw-ring 344, spring pressure is utilized. In this form of the invention, shouldered rods 36 are disposed about the dies and extend through the ram 16, draw-ring 34 and bolster 12. The rods-36" have heads or shouldered portions 36 at their upper ends which rest upon the ram, and shouldered-portions 36 therebelow which are adapted to engage with the upper face of the draw-ring 34. The rods also have shouldered portions 36 below the draw ring, which are adapted to engage with the lower side thereof. This arrangement provides means wherebythe rods 36 have a limited amount of play with respect to the draw-ring and with respect to the ram. Spring pressure is applied to the draw-ring by coiled compression spring 36 confined under pressure between some member of the press, as for instance, the bolster, and a cross bar 36 which is. held upon the rods 3 r by nuts 36, threaded on the lower ends In the operation of this form of the invention, the draw-ring is held up above the lower die 14 by the shoulders 36 of the rods 36", the rods being normally held upward against the action of the springs 36 by the engagement ofthe ram 16 with the heads 36 of the rods. As theram descends,

'the'coiled compression springs force the rods 36? downward,fthereby lowering the draw-ring upon the'work, and as the ram continues to descend, it leaves the heads 36, thereby permitting the coiled compression springs to draw the shoulders 36 of the rods against the upper side of the drawring, thereby placing pressure upon the. blank held between the draw-ring and the lower die. During the up stroke of the ram,

the draw-ring is held down until the ram' engages the heads 36 of the rods 36 and lifts the latter and therewith the draw-ring.

While the invention has been illustrated in connection with a die press for drawlng metal, it is not the intention of the inventor to limit the invention thereto, as it is applicable to various types of power presses.

From the above it is to be observed that the compressed air cylinder at the top of the press aids the crank shaft in its work and relieves it of the usual strain occasioned during its working stroke. Furthermore, that when the draw-ring has been brought intov pressing engagement with the work, the pressure on the work remains constant through the. entire working stroke of the press. Furthermore, that abnormal pressure may be obtained upon the work at any place or places around its marginal pgrtion and that the de ree of pressure may regulated tosuit tie requlrements.

More or less variation of the exact details of construction is possible without departing from the spirit of this invention;

I desire, therefore, not to limit myself to regulating the pressure in each pressure device.

2. In a ower press, in combination with its ram, 0 a draw-ring movable with said ram into engagement with the work, compressed air cylinders mounted on said ram and istons in said cylinders connected with the raw-ring, non-compressible fluid pressure cylinders mounted on said ram having restricted discharge orifices leading therefrom, and pistons in said cylinders connected with'the draw-ring.

3. In a power press, in combination with its ram, of a drawming, movable with said ram into engagement with the work, comprest'ed air cyllnders mounted on said ram and pistons in said cylinders connected with the draw-ring, non-compressible fluid pressure cylinders mounted on said ram havingregulatable restricted discharge orifices leading therefrom, and pistons in said cylinders connected with the draw-ring.

4. In a power press, combination with its ram, of a draw-ring, movable withsaid ram into en agement with the work, hydraulic cylinders mounted on said ram, said cylinders having regulatable restricted discharge orifices leading therefrom, and pistons in said cylinders connected to Said draw-ring. V

5. In a power press, in combination with its ram, of awork holder movable with said ram into engagement with the work, a plurality of hydraulic pressure devices connected to said work holder and means for regulating the pressure in each pressure device.

'6. In aower press, in combination with its ram, 0 a work holder movable with said ram into engagement with 'the work, compressed air cylinders mounted on said ram and pistons in said cylinders connectedwith' the work holder, non-compressible fluid pressure cylinders mounted on said ram having restricted discharge orifices leading therefrom, and pistons in said cylinders connected with the work holder..

7. In a power press, in combination with its ram, of a draw ring movable with the ram into engagementwith the'work, a plurality of fluid pressure devices connected to the draw ring, and means for regulating the pressure in each of the fluid pressure devices.

8. In a power press, in combination with its ram, of a draw ring movable with the ram into engagement with the work, a plupressure in each of the fluid pressure devices independently, one with respect to the other. 9. In a power press, in combination with its ram, of a draw ring movable with the ram into engagement with the work, a plurality of fluid pressure devices connected to the' draw ring, and means for regulating the ressu're in each of the fluid pressure devices lndependently, one withv respect to the other, andat will. V 10. ha power press, in combination with its ram, of. a draw ring movable'with the ram into engagement with the work, a. plurality of fluid pressure devices connected to the draw ring, and means for regulating thepressure. in each of the fluid pressure devices.

11. In a power press, the combination with its ram, of draw-ring associated with said ram and movable therewith into engagement with the work, fluid pressure cylinders mounted upon the ram, pistons, one in each a cylinder connected with the draw-ring, and a compressed air reservoir communicating with said cylinder.

- JOHN NELSON.

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