US2494396A - Air valve with adjustable shutoff control - Google Patents

Description

Jan. 10, 1950 F. M. LITTELL 2,494,396

AIR VALVE WITH ADJUSTABLE SHUTOFF CONTROL Filed May 31, 1946 2 Sheets-Sheet l Jan. 10, 1950 2,494,396

AIR VALVE WITH ADJUSTABLE SHUTOFF CONTROL Filed May 31, 1946 2 Shets-Sheet 2 'I V w ///4L- ggggi Patented Jan. 10, 1950 :PAZTfENT Oi'FFEI GE J ..Littell, Maohine Company, iflhicagoglll ra corporation ofzIllinois 'ApplioationfMaytfil, 1946,:SeriabNo.-'673,554

,2 Claims.

{Ifhe invention-relates-to valves, particularly air ablast valves ortthespecial-stype as shown ;in-Patrents Nos,.:2 ,080,724 ;a:nd:2;302-,242 and hast-for an aobieo t :provide improved ivalve structure f delivering a controlled air blast for ;.removing.

rworkpieoeszandwaste ,rnateri-alif-romwthe working surface of munch presses ior similar machines.

AnothenobjeGt-nf the invention resides in the provision of lair ,blast valves for: purposes as describ dhavingipist nmeans orthe dash p t yp ifor ;regulating the closing; of=thevalve1member ias regard-seach valve rwherehy opening of :the valve .Inemberjs:followedabyieitherr a-rapid or-adelayed ;clesing, depending onxtheeadjustmentoithei =tonme ns.

.An ther object .0.1 :the invention-resides in :the ip vi i fz e aved actionairblast valves which will employ piston and cylinder structure "for -'regu1 tin theclosing-action :of :the valve:-.member ofeach valve and whichmaybe adjusted-over a wide range to suit all requirements as regards :such valves.

-With-these and other-objects in-viewitheinvenytionmayconsist of certain'novel featuresof constru tionand operation =as-wi11zbe more fully described 1 and particularly 4 pointed out in .the specification, drawin seandeclaims appended hereto.

In the drawings which :illustrate an embodiment of the invention and wherein like-reference characters are .used to designate like parts- Figure l is aaside elevational view of a punch press showingga typical installation of the invention with anainblast valve supportedhya side irame member and an air nozzle supported .by the ed plate;

i ure 2 is a longitudinal sectional view taken substantially through the center-of the air "valve .of the invention and showing structural details of the .--same; a

.Eigure 3 :is a 'topplanview of the valve structureshownin Figural;

i ur 4 a bo tom plan view of the valve stru re; and a 7 Figure is a transverse sectional view taken along line 5-5 of Figure .2 and-looking in the dir ction f the arrows- Th installation of the invention is adapted for attachment .to a punch press id as shown in Figure 1, and includes an air nozzle connecting with an air valve for supp ying a blast of air to the die 1,! or other work-supporting surface for removing the workpiece irom the press. The air valv of the invention is provided with operating m ans to he presently described adapted .ior in which is integral "with the valve stem 30.

is rotated-iduring-roperationiof the press YandAaeieordingly the air-valvesis actuated at' the -end-iof reach 3 press operation "to supply 32,11 air blast idf controlled tdur-ationtor-thus removeathe workpiece .f-r.om the press and-which also :maintains thed-ie relean for the next punching operation.

Referring torFigure zof'the drawings,-.the' imz'proved" valvezstructure .of-the: invention essentially consists-10f a body portion of t-suitabl'e metal such i as ihrass TOI :the :like, designated/in its 'entirety by 44. The rear endliof theibodwportion ZM'ilS-IPYO- "-videdwith-a tubularzpart-ilizby meansof which the body :member is gripped and supported .-.1n :adjusted'positionionfthelpunch pressinroperative associated relation with team 1-2. The forward end of the bodysportion M-is formed-wither cylinder part l 6 which is cored zfor .reeeiving a piston comprising an element. ofthe-dash potzmeans v previously referred to. The extreme for-ward endof *the body member 14 is provided-With an extension orear 41,:the-same havingpivotally secured thereto "the :operating lever of the present "valve structure vand "which operating :lever is dip rectly actuatedby .cam not the punchpress.

f ..-a transversely extending bore 24 formed internally of the :body portion 14. Thesaid body portion is threaded'at-opposite ends-of :the bore 24, the upper'threadedend receiving the pipe plug 25 and the :lower threaded end receiving the pipe coupling 26 by means of which the air delivery pipe 1-2?! is secured to the :bodymember in com.- municating -relation with the bore. 7 1 l The valve opening, -rdefined by the valve seat 212, is normally closed by the vailve member 28 The stem 3!! extends through bore 24 "and through V the cylinder part it .of the valve body 14 .to pro tennittent actuation by a cam such as i2, whicl1 ject'from the forward end 'of the same, as-clearly shown in Figures 2 and 3. The coil spring 31, located within chamber I 8 and confined between valve member 28 and the pipe coupling 20 yieldinsly maintains the valve member against its seat 2'2, permitting movement, however, .of the valve member against the tension of the spring to open the passage 23. When valve member 28 is open 3 air under pressure from the inlet pipe 2| is delivered to bore 24 and thus to delivery pipe 21. The forward end of the valve body, from which projects the valve stem 30, is provided with the extension or ear I! to which is pivotally secured the actuating lever 32. The lever is suitably secured to extension I! as at 33, which is approximately half-way between the extremities of the lever. It will be observed that the lever is approximately of right angular shape, having one leg extending vertically in front of the valve body [4 and having its other leg extending horizontally under the forward end of said valve body. Lever 32 may be considered as cored internally to provide spaced side members and within which the extension I! is located. The roller 34 is also located within the spaced side members of the lever, the same being journalled by the pin 35. Roller 34 is positioned in alignment with the projecting end of stem 30 and said roller is adapted to contact stem 38 to reciprocate the stem and thus open valve member 28 upon actuation of the lever member in the proper direction. The lever member 32 also carries at its extreme upper end a roller 36 which is journalled by stud 31. Said roller is adapted to have contact with cam 12 and as the high point of said cam engages the roller the lever 32 will be oscillated ina counter-clockwise direction, Figures 1 and 2, with the result that stem 30 is reciprocated to open valve 28 as described. In accordance with the invention, the closing of valve 28 is delayed so that an air blast of the proper duration will be delivered to the die H or other work supporting surface of the press. This structure will now be described.

The cylinder part I6 of the valve body is cored to provide a cylinder 38 which opens on the undersurface of said part. A piston 48 is located in said cylinder for reciprocating movement, which movement is imparted thereto by the lever member 32. The piston 48 is connected to lever member 32 by the connecting link 4! pivotally secured at one end to the piston by means of pin 42 and at its opposite end to said lever member by pin 43. The compression end of the piston is provided with a leather washer 44 and which is effectively maintained in desired cupped formation by the metal insert 45, the insert being secured to the piston by screw 46. The cylinder 38 is provided with an air inlet passage 41 and an air discharge passage 48. The air inlet passage 4'! is equipped with a valve element designated 58 which is suitably threaded asat into cylinder part It. The valve element 58 functions as a suction valve to admit air through passages 52 into the cylinder 38 upon a suction stroke of the piston. The valve stem 53 carries at its lower end the valve 54 and which is normally held in closed position against valve element 50 by means of the coil spring 55. Said spring is located within a bore formed in the upper end of valve member 50 and is confined between said valve elementand-washer 56 secured to the end of the stem 58 by screw 51. Valve 54 will open only upon downward movement of piston 40 since the vacuum created by said downward movement of the piston is operative to overcome the tension of spring 55. This downward movement of valve 54 allows air to enter chamber 38 from openings 52. The valve 54 closes since it is tensioned by spring 55 just as soon as the vacuum within chamber 38 has been relieved. On the up stroke of piston 48 the air within chamber 38 will be compressed and forced from the same through the discharge passage 48. However, said discharge passage is provided with the needle valve screw 58 threaded at 60 to the cylinder part I8 and which may be adjusted to close off the air discharge passage 48 to any extent desired. The air flowing past the needle valve screw 58 is exhausted to the atmosphere through passage 6!.

The air valve of the invention is suitably supported by the side frame member 82 of a punch press or the like having the die member H, as previously described. The cylindrical portion l5 of the valve body is suitably fastened to the split collar member 63 supported by the adjustable ball socket structure 64 and which is secured to the side frame member 62. As a result of the ball socket structure 64 and the collar member 63 the air blast valve may be adjusted in proper longitudinal position with respect to the cam l2 and in proper rotative position as regards said cam. Air under pressure is supplied to the valve by means of the air inlet pipe 2! and in a controlled manner the pressure medium is supplied to the air delivery pipe 21 connecting with the nozzle 65 supported in adjusted position by 66 adjacent the die I 1 comprising the work supporting surface of the press.

During operation of the press the cam 12 is rotated and upon each revolution thereof the high point of cam l2 will effect movement of lever member 32 in a counter-clockwise direction as previously explained. This movement of the lever member will produce reciprocation of stem 38 to open valve member 28, thereby admitting air under pressure through the air delivery pipe 21 to nozzle 65. Actuation of lever member 32, as above described, will also produce downward movement of piston 48. This downward movement or suction stroke of the piston will draw in a supply of air through the vacuum valve 54 which will immediately close when the suction within chamber 38 has been relieved. When the high point of cam 12 has passed beyond roller 36 the coil spring 3i will become effective for closing valve member 28. Opposition to this closing action, however, is offered by the piston 48 which in moving upwardly compresses the air within chamber 38 and a certain time interval is required before all the air from chamber 38 can escape through the adjustable orifice 48. The piston 48 in combination with the needle valve screw 58 functions as dash pot means to delay return of the valve member 28 to a closed position. By adjustment of the needle valve screw 58 the rate of discharge of the air within chamber 38 can be regulated so that the closing action of valve member 28 can be controlled to suit operating conditions for the particular press to which the valve structure is applied.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. An air blast valve of the character described, in combination, a body portion having an air passage provided with a valve seat, a valve for said seat having a stem extending through the body portion and projecting from the forward end of the same, resilient means located rearwardly of the valve in contact therewith for maintaining the valve closed, a lever member pivoted to the forward end of the body portion and operative to reciprocate the stem to cause opening of the valve upon pivotal movement of the lever member in one direction, said forward end of the body portion providinga chamber, a piston within said chamber, means operatively connecting the piston and said lever member so that the piston has a suction stroke upon pivotal movement of the lever to openthe valve and has a compression stroke upon pivotal movement of the lever for closing the valve, and other means controlling the admission to and discharge of air from said chamber, whereby the pivotal movement of said lever member is delayed in a direction to delay losin of the valve.

2. An air blast valve of the character described, in combination, a body portion having an air passage provided with a valve seat, a valve for said seat having a stem extending through the body portion and projecting from the forward end of the same, resilient means located rearwardly of the valve in contact therewith for maintaining the valve closed, a lever member pivotally secured intermediate its ends to the forward end of the body portion, one leg of said lever member being operative upon pivotal movement of the member in one direction to reciprocate the stem to cause opening of the valve, said forward end of the body portion providing a chamber, a piston within said chamber, means operatively connecting the piston and said other leg of the lever member, whereby the piston has a suction stroke upon pivotal movement of the lever member to effect opening of the valve and a compression stroke upon pivotal movement of the lever member for closing the valve, and means controlling the discharge of the pressure medium from the chamber upon the compression stroke of the piston.

FREDERICK M. LITTELL.

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

UNITED STATES PATENTS Number Name Date 557,292 Turner Mar. 31, 1896 FOREIGN PATENTS Number Country Date 501,997 Germany July 8, 1930

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