US2631573A - Valve mechanism - Google Patents

Description

March 17 1953 v MUNI l l ro HR M 5M a g U l 'nl j! J2 Il ill G I G INVENTORS' .Perry B. Le Wu# BY MM45 i arson )yf/M7 /l HTWMFX March 17, 1953 P. B. LEvlTT ETAL 2,631,573

VALVE MECHANISM Filed sept. 9, 195o s Sheets-snede l IN V EN TOR. Percy B. Lea/1'# T /1 ou a as /lnderson BY 22K/fw; 9.0%@

. IITTURNEY.'

P. B. LEVITT ET AL VALVE MECHANISM March 17, 1953 Flled sept 9 195o Patented Mar. 17, 1953 UNITED STATES PATENT yOFF ICE VALV MEGHANISM Percy Levitt, Millburn, and lhomahs Anderson,

Roselle, N, J., assignors vto Cities .Service Re- Search and Development Company, New York, N. Y corporation of New Jersey Application September 9, 1950, Serial N0. '183,962 6 iCAlalni'S. (Cl. 121-464) This invention relates 'to valve mechanisms, `and is more especially :concerned with valves devsignedto vadmit and discharge air to the cylinder of a compressed-air-'driven pump.

It is an object fof this invention to 'provide a simple and sturdy valve mechanism for use in a high speed vcon'lpressed-air-driven pump, apartir:- ularly for use 'in 1handling grease yor other viscous materials, such 'as the high pressure greas- Aing apparatus disclosed in U. S. Patent No.

yIt lis a further object of this invention to .provide a valve mechanism in which all operating and actuating .parts are completely enclosed and protected against dust and dirt, .and in which the valve plungers are self-lubricating.

It is still ano-ther object -to .provide a valve structure in which the air inlet and outlet ports can be made of relatively large lcross-sectional 'area compared to the 'overall size of the valve structure, and which, when 'in -open position, are not obstructed by valve stems Aor other objects 'tending to crier resistance Vtothe free ow of :ali-r through the ports.

In order that those skilled in the ar't may more -fully appreciate the construction of the new valve mechanism `and vlits manner of operation, it will he more fully :described in connection With 'the accompany-lng drawings., in which Fig. l is a View, 'partly V'in Vcross--sectio'm of a grease dispensing apparatus of the type `disclosed in U. S. -Pate'nt 2,007,113, and incorporating the improved vvalve m'ecl-ia'n-is'm 'of the in- Vventiony .on line'Z-Q of Fig. 2.

Fig. 4 is a Vertical cross-'sectional view of the valve and air cylinder as it .would appear when in a position to admit air to the cylinder, and

Fig. 5 is a vertical cross-sectional view of the valve and air cylinder las it would appear when in a position to exhaust air 'if-rom the cylinder.

IReferring more .particularly to Fig. 1 grease is placed in a pressure reservoir I fitted with yan air-tight cover .plate :2, to which vair may Vbe admitted through an fair line -3. When air under pressure 'is admitted tothe reservoir ift-he grease will tend to be forced fout of the pressure reservoir l through aline .4 tted withta foot valve `5 Vinto the pumping cylinder i6 of an 1'air-soperated spun-ip 1. When operating with soft grease, it may not be necessary to place air pressure in ,reservoir i, but when operating with lhard greases, pressures from to 300 p. s. i. may be vnecessary vto force the grease into pumping cylinder 6. .On Ithe downward stroke of the piston plunger I0, foot valve 5 will close and grease will be forced through a grease 'line Il., provided with a check Valve I2, to an appropriate grease gun (not shown), and on the upward stroke of the piston plunger il), foot valve l5 will open, and grease will vbe delivered from the pressure reservoir I through the line Il into the pumping cylinder 6.

Referring now more particularly to Figs. 4 and 5, in Fig. 4 it will be noted that valve plunger 3l is in raised position so as to permit free flow of air into the air cylinder I9 of the pump through intake air port M whereas valve plunger 38' is in lowered position, so as to close oli exhaust port 45 and prevent the escape of air therethrough. Compressed air, entering the cylinder I9 through port 44 and its associated air passage 42, will then force the piston I6 and plunger to downward, forcing grease into grease vline Ii. As the piston IE nears the end of its downward stroke, as illustrated in Fig. 5, it Willmake contact with an actuating rod I3, shifting the rod downward. This downward shifting of .the rod i3 will, as will more particularly be explained hereafter, cause the valve mechanism 5Fl to snap into .the position shown i-n Fig. 5-, vin which position valve plunger v3l will block-01T air port M, shutting off the flow of `air to the cylinder, while valve plunger 38 is in retracted position, opening exhaust port i5 to allow air to escape from the cylinder.

With exhaust port 45 open, pressure in the cylinder will rapidly be reduced to atmospheric, and the piston l5 will be returned to the position shown in Fig. 4 by spring Il, compressed between the piston I6 and the bottom wall I S of the cylinder I9. As the piston approaches the upper end of its stroke, it will again make contact with actuating rod I3, this time shifting the rod upwardly. This upward shifting of the rod I3 will cause the valve mechanism 50 to snap back into the position shown in Fig. 4, and the piston will begin its downward stroke under the influence of air admitted through port 4-4.

-As shown in Figs. 4 and 5 actuating rod I3 fits loosely with a hole, slightly shorter than the length of the vpiston stroke, in the piston plunger Iii, the rod I3 having an enlarged head I4 at the lower end thereof, of such size andfshape as to ymake 'contact with (a bushing .I 5 at the upperl end of the hole in the piston plunger I0 when the piston is at its lowest position, as illustrated in Fig. 5. The upper portion of the actuating rod I3 passes through a stufling box 20 in the upper wall 2| of the air cylinder I3 and the base plate 22 of the valve assembly, the base plate 22 being secured to the upper wall 2l as by bolts 22'. It will be appreciated, of course, that the various parts of the valve mechanism may be mounted directly on or in the upper wall 2 I, in which case the base plate 22 may be dispensed with, but for ease in servicing and replacing` the valve mechanism, the unitary valve structure illustrated in the drawings is preferred. rihe end of the actuating rod I3 iits within a hole 23 in a block 24 and is attached thereto as by a set screw 25, although any other means of attachment may be used. The hole 23 preferably extends through the block 24' in order to facilitate adjustment of the rod I3. The block 24, which is provided with slots 26, is slidably mounted on a vertical post 2l which is attached to the base plate 22 of the valve assembly in an3 convenientmanner, such as by threading it into oase pla-te 22.

rihe block 24 is connected by a pair of resil ient members such as springs 33, to the middle joint 3l of a toggle member 32, the upper arms of which are connected to a fixed pivot, illustrated in the drawings as a rod 33 passing through the post 2l and the slots 25 of the clock 2d. The lower arms oi the toggle member 33 are hingedly connected to a pair of rocker arms 34 near one end thereof, the rocker `arms 315i being pivotally mounted on a pair of spa-ced lugs 35 aiiixed to the base plate Z2 of the valve assembly. In order t achieve economy of space, the rod I3 and post 21 are centrally located between the rocker arms 34. The rocker arms 33, which may be braced as by studs 36 connecting their ends, carry a pair oi blocks 3'! and 38 into which are fitted valve plungers 3l and 38', the blocks being held in position by pins 39 and l0 passing through slots lli in the rocker arms 34. Obviously, the crosssectional area of the valve plungers 3i and 3S may be widely varied without affecting the size of the other parts oi the valve mechanism, and may be of such area that the air cylinder i9 may be rapidly filled and evacuated without appreciable back-pressure due to friction in the intake and exhaust lines, thus enabling Ythe pump to be continuously operated at high speeds.

Preferably, when the plungers are equidistant from the rocker arm pivot, as illustrated, they are or equal cross-sectional area, in order to balance the forces acting against each end of the rocker arm. However, if they are spaced at unequal distances from the pivot, their respective crosssectional areas should be such that forces resulting from air pressure in the cylinder are balanced, so that the valve will not shift from one position to another in the middle of the upward and downward strokes of the piston.

Valve plunger 3l moves slidably within and operates to control the intake air port 42 and valve plunger 38 similarly operates to control the exhaust air port 43. Intake air port l2 connects with air line 3 by an air passage fifi, which is threaded to receive a standard air connection, and. exhaust air port 43 is connected with an air passage 35, which vents to the atmosphere.

Those parts of the valve assembly lying above the base plate 22 are protected against dust and dirt by a cover plate 35, attached to the base plate i2 as by bolts 4l. It will also be observed that the actuating rod I3 is entirely enclosed within the pump, and is protected from any out- 4 side interference while the pump is in operation.

Referring now more particularly to Fig. 4, which illustrates the position in which the valve parts would be when starting up the pump, air is admitted to the cylinder I9 through intake air passage 43 and intake air port 42. Air will now flow into the cylinder I9, forcing the piston I6 down to a position at which the shoulder of the emerged head 'Ill on the end of the actuating rod i3 will come into contact with the bushing I5 at the upper end of the hole in the piston plunger Ill. A further downward movement of the piston plunger It will pull the actuating rod I3 with its attached block 25 downward causing the center line of the springs 33 to pass, in a downward direction, the nxed pivot 33 of the toggle member 32. As they pass this fixed pivot, the springs 30 will cause a downward resultant force to be applied to the middle joint 3l of the toggle member 32 causing the rocker arms 3d to snap rapidly to the position shown in Fig. 5, in which position the air intake port t will be closed by its associated valve plunger 3l and at the same time the exhaust air port i3 will be opened, by withdrawal of its associated valve plunger 33.

The piston i3 will then start on its upward journey under the inuence of the spring II. Near the end of the piston stroke the end of the rod I3 will come in contact with the bottom of the hole in the piston plunger lil, tending to force the rod I3 upward. As the actuating rod I3 moves under the influence or the pump piston I6, it will move the block upwards, and cause the center line of the springs 33 to cross the xed pivot 33 of the toggle member 32. The resultant force exerted by the springs 33 on the middle joint 3| of the toggle member 32 will then be in an upward direction moving the rocker arms 34 rapidly back to the position shown in Fig. 4, moving intake valve plunger 3l upwards and allowing air to ilow into the air cylinder I9 through the inlet air port 42, and at the same time causing the exhaust valve plunger 33 to move downward to block ofi the exhaust air port 43. Air may now ow into cylinder It to start the piston on its pumping stroke. Y

When :operated in an .upright position, the Valve stems and the operating rod may be made self-lubricating by placing a layer of oil on the surface of the lbase plate. -Iit has been -found that, with the valve plungers 31 :and 38 and air ports i2 .and `fit machined to fit so 'that no air will be 'blown upward past the Valve plungers, and when using ,lea-ther .packing in the stuing boX `20 through which rod I3 passes, 'there is no leakage of oil into the air :cylinder after long periods Voi use, and the rod and valve stems need no additional lubrication.

Having now described our invention, what We claim as new and useful is:

1. A valve assembly, :including iin combination a base plate, a rocker arm fpivotally mounted on said base plate, valve :plungers connected to each end of said rocker arm, and operable to con-trol the flow of air through an inlet air` passage and an outlet air pass-age in said base plate, a vertical post mounted on said base plate, a toggle member connecting one end :of the rocker arm with a fixed pivot .on the post, .a .block slidably mounted on the post, a resilient member conneeting the center pivot of the toggle mechanism and the block, and means fsor moving the block along the -post whereby yto cause the center line of the resilient member to pass `from one; side of the xed vpivot to the other.

2. VA valve .assembly including in combination air cylinder, a rocker yarmpivotally mounted y cylinder, a @toggle member connecting one end of the rocker arm with a xed pivot on the post, a block slidably mounted on the post, :a resilient member connecting the center pivot of the toggle member and the block, a rod connect-ed to the block and passing into .the interior of the air cylinder, `and means f-or moving the said nod vand attached block whereby to cause lthe center line of the resilient member to pass from one slide of the xed pivot on the post to the other.

3. A valve assembly including in combina-tion an air cylinder, a rocker arm pivotally mounted on said cylinder, valve plungers connected to either end o1" 'said rocker ,arm andopenable to control the fioW of :air thnough an air inlet apassage .and an air outlet passage in the said cylinder, a vertical :post mounted on the-cylinder, a toggle member connecting one end of the rocker arm with a rfixed pivot on the post, a resilient member connecting the center pivot of the toggle member with a rod passing into the interior of the ai-r cylinder, and means for .moving the said rod whereby to cause the center line of the resilient member to pas-s from one side of th-e -ixed pivot on the post to the other.

4. A valve assembly inclu-ding in combinati-on an air cylinder, .a piston reciprocably mov-able in said air cylinder, a rocker arm pivotally mounted on said cylinder, valve plungers connected to either Iend `of said rocker larin and operable to control the Jdow of air through .an air inlet passage and an .air outlet Apassage in said cylinder, a vertical post mounted Ion said cylinder, a toggle member connecting one end of the rocker arm with a iixed pivot on the post, a block slidably mounted on .the post, a resilient member connecting the center pivot of the toggle member with Ithe block, a yrod connected to the block and passing into the interior of the air cylinder, the said rod being connected to the pist-on by means of a lost-motion connection in such manner that the rod will be move-d by the piston at each end of its stroke for a ydistance sufficient to cause the center line of the resilient member to pass from one side of the fixed pivot on the post to the other.

5. A valve assembly including in combination an .air cylinder, a pist-on reciprocably movable in said `air cylinder, la Irocker arm .pivotally mounted on said cylinder, valve fplung-ers connected to either end of said rocker arm .and :operable to control the flow ofair 5throu-gh `an yali-r inlet passage and .an air outlet passage in said cylinder, a vertical post mounted :on said cylinder, a toggle member connecting one end :of the rocker arm with Aa fixed pvot on the post, a resilient member connecting the center pivot of the toggle .member with a rod passing into the interior of the lai-r cylinder, the said rod being connected to the piston by means of a los -motio-n connection in such manner that .the rod will be moved by the piston aft each end of its stroke for a distance sufcient to cause the center line of the resilient member to pass from Ione side Aof the xed pivot on the post tothe other.

6. The valve assembly according to claim 5 in which the valve plungers are of such cross-sectional Iarea that the resultant forces ydirected against each end of the rocker arm due to air pressure in the. cylinder are substantially equal.

IPERCY B. LEVITT. THOMAS ANDERSON.

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

UNITED STATES PATENTS Number Name Date 223,943 Myers Jan. .27, 1880 1,825,411 Murphy Sept. 29, 1931 2,065,144 Miller et .al Dec. 22, 1936

Images