US2482280A - Shock cushioning pneumatic press - Google Patents

Description

- Sept. 20, 1949. s. LERMA 2,482,280

SHOCK CUSHIONING PNEUMATIC PRESS Filed Jan. 12, 1948 3 Sheets-Sheet l 45 llil HAND CONTROL Al NLET FOOT GONTROL STEPHEN LERMA INVENTOR ATTORNEY Sept. 20, 1949. s. LERMA 2,482,280

SHOCK CUSHIONING PNEUMATIC PRESS Filed Jan. 12, 1948 3 Shee'tsSheet 2 -\J STEPHEN LERMA INVENTOR ATTORNEY Sept. 20, 1949. s. LERMA 2,482,280

SHOCK CUSHIQNING PNEUMATIC PRESS Filed Jan. 12, 1948 3 Sheets-Sheet 3 ATTORNEY iiill: 1

N 1 m J q- STEPHEN LERMA INVENTOR. LL

Patented Sept. 20, 1949 UNITED STATES" PATENT OFFICE 2,482,280 snooK CUSHIONING PNEUMATicPR Ess Stephen Lerma- Flushing, N. Y. Application January 12,. 194s,.ser1a1N6. 1,ss1-

2 Claims. (01 113-45) This invention relates to an apparatus for controlling the operation of apneumatic press and more particularly to mechanism for gradually increasing the magnitude of the impact on the work in a press during each power stroke. In order to produce high grade formed articles,

it is necessary that the various steps in forming the articles by the pressing method shall be accomplished under accurate control. It is also required that the pressing or deforming of a.

blank shall not be carried .out at too great a rate of deformation. When the forming is carried out at too rapid a rate, there is produced an internal stress which either alters the material or even causes rupture of the material.

An object of this invention is to provide an improved multi-stage single stroke pneumatic press in which a composite plunger or working member may. have an advance movement and then at desired points in the advancement of the composite plunger, increasing and pre-determined pressure stages are made available automatically to the maximum pressure of the press.

Another object of this invention is to provide an initial spring cushioned low pressure impact on the work by the composite plunger.

Another object of this invention resides in the provision of an inlet valve which is automatically 7 opened to cause the fluid in the high pressure air cylinder to be delivered to a cushioning device at a desired stage of the working stroke of the a slidable cup shaped extension member on the.

composite plunger forming an intermediate pres sure chamber, an air relief valve being in communication with the' intermediate pressure chamber, whereby the air pressure in the intermediate pressure chamber may be varied to provide an intemediate pressure impact less than the full pressure plunger impact of the press.

With the above and other objects in view, the invention will be hereinafter more particularly aid control valve.

of parts will be shown in the accompanying drawvings and pointedout in the claims which form part of this specification. p

' R'eference willnow-be had to the drawings,

wherein like numerals of reference'designate corresponding parts" throughout the several views,

.in which I Figure l is a frontelevationof the pneumatic shock cushioning-press, the plunger cylinder be- ;lng shown incross-section.

Figure 2 is a front elevation on an enlarged scale, the intermediate pressure chamber being shown in cross-section. I

Figure 3 is a top plan view of a hand operated Figure 4 is a side elevationfpartly in crosssection of the controlvalve shown in Figure 3. r In the illustrated embodiment of the invention,

the'numeral it indicates a pneumatic press comprising a base H from which extends upwardly a frame, [2 which supports a mam air cylinder l'3. The cylinder [3 is closed by a cover I4 having a boss I5.for guiding a plunger l6.

Inside'the cylinder 13 apiston I! which .is

suitably secured to the upper end portion, of the plunger 16. A coil spring I8 is interposed between the cover l4 and the piston l! for supporting the plunger in upright position.v

The pistonil'l .is actuated by compressedair which] is supplied through air hose 20 and through'a' globe valve 2| which is suitably connected'to an aperture22' in the upper portion of the cylinder l3. 1

For the purpose of provldinga safety feature in the operation of the press l0, there are two hand operated air control valves 23 of identical design and respectively secured at each side of the base H.

Each valve 23 comprises a rectangular body 24 having an inlet 25 and an outlet 26. Resiliently supported in the body 24 by a spring 21 is contacting relation with the upper end of the valve 28;

V A hand operated lever 32 is pivotally mounted on a pin 33 in abracket 34 secured to the body 24; When the lever 32 is down pressed, it causes the push rod 30 to lower the-right-hand valve 28 from its seat and to permit compressed air to pass through the inlet 25, through the valve describedand the combination and arrangement body 24 and out through the outlet 26. The compressed air then passes through a hose 35, through the left-hand valve 23, through a hose 36, to the globe valve 2|.

The valves 23 must'be operated simultaneously by both hands of the operator in order to supply compressed air to the plunger l6. This keeps the hands of the operator away from the upper and lower plate members of the die set 31, 38.

The piston I! may. however be actuated by compressed which is supplied from afoot operated control valve 40 secured to the floor, adjacent to the press ID. The control valve 40 may be of the type shown in Patent Number 2,388,560 and needs no furthi dis'cr' iiiiiion. l It is to be noted that the air from the cylinder I3 is discharged through an aperture 41 iii the cylinder wall when the uppeit iabe 'o'f'the bistiin I! passes below the aperture.

For the purpose of cushioning the shock 'of the upper die set plate member 31 against the work, I'prbl'fiide a clip shaped plunger extension '42 which S1idab1y mounted at the lower "end i305." tion of the plunger Hi. The member 42 fis supported oh the lunger 1 6by retaining 43 fixed in the member 42 and passing through slots 44 "ih the'plil'nger f6.

An open coil compression spring 45 is inter 'pb'sed between the IOWET efld f the manger l and -a horizontal surface in a recess or intermediate pressure charribeiflii in the plunger extension 42, T e spring 45 maintains the hori- 'zo'nt'al surface of the recess 46 in the'plunge'r exlower end-oi the plunge v It is to be noted that the compression spring '45 exerts "a consid rable pressure in a downward direction against the plunger extension -42 and when the plungerf|'6 low'ei's tlie upper the 'set -hiember 31 against the work, a low pressure impact 'is. exerted on the work by the s rin 45 f prior 'to the exert on of the'i iiljpressure plunger impact of the .iire's's 10. This low pressure impact takes p la"c"e curing theftiine it takes for the lower end of the plunger l6 to reac'l'hthe upper surface oia boss orihipact head it inside the plunger extension 42.

For the purpose or-iiirther cushioni g the shock f the upper the set platejm'ember '3! 'aga'ii 'stthe work, I provide "an"l'elohgatdipassage l "way 48 in theplun'ger Hi. The passageway '48 eitend's from "the upper surfac i the pistoirll down to waive chamber is inside the plunger 1'6. An inlet valve 54 is slidably mounted "the chamber 49 with the valve head 51 seated "iii a. tapering valve seat 52. A j'coil springer "is interiposed between the upper surface of the verve chamber 49 and the upper surface of the valve head 5I-.

it is to benoted that a valve o erating screw ja l is threadably mounted iil th'e boss '41 anirmay "be adjusted With-relation to the lower surface 6? 'thevalve head 5I so that prior to the contacting relation of the lower surface off the .-.p'lung'er T6 with the upper surface of the boss 41 the screw 54 will raise rthe valve -50 ofi its seat and .permit compressed air from the cylinder 13 to enter the intermediate pressure chamber 46 through the passageway.

- a bly connected in communication with the recess 46. The valve 55 well known in -the art, may be set to maintain the pressure in the intermediate tension 42 in spaced-apart "relation from the 4 V the work greater than the impact produced by the spring 45.

'It is further to be noted that continuation of a single power stroke finally brings the full- 5 pressure plunger impact on the work.

It will thus be noted that there has been provided a multi-stage impact cushioning pneumatic press comprising a single power stroke composite plunger adapted to deliver step-bystep increasing Zpiessiires; on the tfvoi'h fsdjtl'ifat the deformation or forming of the work willbe gradual and prevent rupture of the material, and which will "also increase the life of the die parts.

i In iipei'atib'nfasthe die parts 31, 38, are brought together, there is a compression of the spring 45,

which results in a soft impact on the work.

I-herising pin $4 opens the valve 50 and allows compressedair to enter the chamber 46, a

predetermined amount v of which is set to escape higher and p'r'edetermined impact-on the work.

' "relief Y e a erture i'sfthen shut off by the lowered piu hger la' and a blow -'o' f full impact is delivered on the work. 7

Inste'a'd o'f bringing 'th'e-di'e parts 31, 38, together with the iii-ll impaetahd taking a chance of damaging the material worked upon, this ste by- "s'tep impact arrangement *subdivides' the total inipact into three stages. a v I the arrangement shown. the relief valve 5'5 connected below the lower' face of the plunger 116 and eah relieve the pressure only when the die pa scies are operating relation; that is, rinlv-Eiii'riii the meineritaryperiod when the work is compressed. 1

It will be. een that this invention provides iheai s 'ior co -troilihg the iiovv or a pressure 'fluid to afid frdn a plphge'r 'susta'ihed cushioning clevijce airiiis adaptabletovaribu's'kinds "of presses.

Iii practice. the lower end portion 51 "of the 'piu ig'er e tension =4? is threaded to permit the juppendi'e'me'ihbei' '3'! 'to be 'tliieadably adjusted th reohanrl 'th eh secured ih position by a bolt '58. Figures lahd2 show a pipe"60 'c'onnected"to the lower portidhjof the plunger extehsion d'z. The pi e 60 is in al'iii'ein'eht with a pipe 256 for the Iii accordance with the patent statutes I have described and illustrated the 'p'rei'er'ieaehi bodirnents (if my 'inveritionjbuteit will 'be. understood that various changes and modifications can'be n;ia d e therein "without departing from. the. spirit of the invention as dehn'edby the appended e is- 1 v having an air pressure cylinder, .9, piston sli'dab'le insaid-cylinder and comprisinga .plunger extenl- V ingthrough one endo f-tlie cylinder, said plunger having a cup-shaped extension member s'lidably mounted-at its lowerend viliile retained thereon against disengagement, la compression spring ina chamberior med between said extension member and the lower end oi plunger and exerting pressure against the low er face oi? said plunger, said spring limiting the impact or said extension through the relief valve 55, thereby providing a member on the work, a spring-closed inlet valve slidably mounted in said plunger, means in said extension member adapted to open said inlet valve upon substantial compression of said first named spring, said valve when open admitting air under pressure from said cylinder to said chamber to cause controlled pneumatic pressure impact on the work, a pressure relief valve communicating with said chamber, an impact head on the extension member arranged to contact the lower face of said plunger after the inlet valve has been opened, and means for closing communication between the relief valve and the chamber just before the impact head engages the plunger.

2. In a multi-stage impact cushioning press having an air pressure cylinder, a piston slidable in said cylinder and comprising a plunger extending through one end of the cylinder, said plunger having a cup-shaped extension member slidably mounted at its lower end while retained thereon against disengagement, a compression spring in a chamber formed between an inner face of said extension member and the lower end face of said plunger and exerting pressure against the lower face of said plunger, said spring limiting the initial impact of said extension member on the work, a spring-closed inlet valve slidably mounted in said plunger, adjustable means in said cup-shaped extension member adapted to open said inlet valve upon substantial compression of said first named spring, said inlet valve when open admitting air under pressure from said cylinder to said chamber to cause controlled pneumatic pressure impact on the work, an adjustable pressure relief valve communicating with said chamber, an impact head on the extension member arranged to contact the lower face of saidplunger after the inlet valve has been opened, and means for closing communication between the relief valve and the chamber just before the impact head engages the plunger.

STEPHEN LERMA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 790,566 Eicher May 23, 1905 1,544,573 Glasner July 7, 1925 1,844,250 Hawkins Feb. 9, 1932 1,937,908 OBrien Dec. 5, 1933 2,163,517 Oeckl June 20, 1939 2,344,114 Sedgwick Mar. 14, 1944

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