US1348084A - Vacuum fuel-feed device - Google Patents

Description

C. S. BURTON.

VACUUM FUEL FEED DEVICE.

APPLICATION nuzo AUG-16.19%.

1,348,084, Patented July 27, 1920.

2 SHEETS-SHEET I c. s. BURTON.

VACUUM FUEL FEED DEVICE. APPLICATION man nums. ma.

1,348,084, Patented July 27, 1920.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

CHARLES S. BURTON, 0F OAK PARK, ILLINOIS. ASSIGNOR TO STEWART-WARNER SPEEDOMETER CORPORATION, OF CHICAGO. ILLINOIS. A CORPORATION OF VIR- GINIA.

VACUUM FUEL-FEED DEVICE.-

Specification of Letters Patent.

Patented July 27. 1920.

To all 'tIIHI/Il 2'! may eon/era:

lie it known that 1 (lnaumcs S. liUltlHN, a eitizen ol' the l nited States, and a resident of the village of Oak Park, in the eountv ol' (ooh and the Slate ol lllinois..

have invented certain new and useful llllprovements in Vaeuum Fuel-Feed lleviees, ol' \vhieh the following is a sptwiliealiou, referenre living had to the at'eompauyiin; drawings, forming a part thereof.

The purpose of this invention is to hrovide an improved eonstruetion of vacuum fuel Feed deviees for internal eomhustion engines \vhieh shall he partieularly adapted for furnishing the Fuel lifted from a lowlevel main supply tankwvhen the suction availahle is low in small quantities and short intervals as it is thus lifted. and othen wise to adapt the deviee to have greater feeding' and storage eapaeity wilhin given over-all dimensions. ll eonsists in the elements and features ol eonstruetion shown and deserihed as iudiealed in the t-laims.

In the drawings;

Figure l is a vertieal seetion ol' the upper portion eomprising the entire valve eontrolling ('oilneeliions and operating float Ill a deviee embodying this inventioin th lower part of the float ehamher and the reservoir ehamher heing hroken away.

Fig. is a seetion in a plane at right angles to that of Fig. 1, showing the same construction, with a middle portion oi the vertieal extent of the reserve ehamher hroken away to reduee the eompass of the view.

I Fig. 3 is a seetion at the line Zl3 on ig. lis a section at the line 44 on Vi". L looking upward.

ig. 5 is a detail seetion at the line 5 on Fig. 4. looking radially inward.

The prohlem the solution oi whieh is attempted in this invention, is to adapt a var uum fuel t'eed deviee of the type eomprising a vaeuum ehamher and. a reserve ehambe! and whieh derives the suction for operating it from the manifold of the engine \v-hirli is to he served, to release and deliver to the reserve ehamher the liquid fuel whieh is sucked up from the main low-level supply tank into the vaeuum eha uhen at the shortest praetiea le intervals when the eonditiou is such that the supply is low and the suelion light; these two eonditvions heing usuall v eoiu-nrrent, that is the. suetion hein; light nhenevel'lhe eonditions have for some time heen sueh as to reduee th revserve supply to :1 low point.

In the familiar lleviees for this purpose now in eonnnon use. there is employed what is known as a snap aetion l'or eausing a quiek reversal of the situation of the valves whieh eontrol the (lfllllllltllltt in the vaeuum ehamher of atmospherie pressure or suetion. This snap aetion is constructed to Cause the ehane'e of level of the liquid in the vacuum ehamher, hy means of the tioat therein, to shift eertain valvtwlperating lever eonneetions with \vhieh the snapsprin;: is conuerted, as the float rises or falls. moving one eonneetion of the spring until its line of reaetion extends past the tulerum of the, le\er eonueeled thereto. the spring at this stage heine' at maximum tension, and therefore reaeting to eontinue the throw of the levers in the direetion in \vhieh they have heen moving to thuwteusion the spring. In slu-h strlu'tlll'e the reaeting spring furnishes the sole meehanieal three for moving the valve or valves to he shifted; and sinee the valves in question are held by the suction in resistanee to the movement to he thus auseth the spring must he'eonstrueted to have at this stage of maximum tension adequate tension to move the valves against the maximum suetion: heeauso ohviously the spring tension is constructional, and will not he ehanged hy the ehanging conditions of suelion. but must he adequate for the extreme eonditions whieh may arise.

Now in any eonstruetion in whieh the valve levers are actuated only hy the springs and the lloat obtains no direet'aetion on the valve-operating eonneetion, inasmueh as the tension of the snap-spring is overeome hy the huoyaney or weight of the float in musing the reversion of the valve situation. and the operative'huoyaney or operative weight ol' the lloat depends on the extent to whieh the lloat is depressed in or held up out of the liquid hy the spring resistant-e there eannoi he any variation in the height to \vhieh the liquid must rise or the depth to whieh it nmst fall in order to reverse the valve situation: and the quantity of liquid taken in and delivered at eaeh eyele oi the operation of the deviee, must always be the same whatever he the suction operating, and whatever the condition of the device as to reserve supply. It follows that in such a structure the purpose of the present invention, namely, as above stated, to adapt the device to receive and deliver small charges to the reserve chamber, so as to make such deliveries quickly when the reserve supply is low, can only be accomplished by making the structure so that small charges shall be received and delivered at all times and under all circumstances,

It will also be evident upon consideration, that with a given rise and fall of the liquid level in the vacuum chamber requisite for reversing the valve action, the frequency of such change, which depends upon the quan tity of liquid going in and out to make the change, can be increased,-that is the quantity can be reduced,*by reducing the cross section of the vacuum chamber in which the liquid level rises and falls in such change, or by reducing the amount of such change of level, that is, the vertical dimension of the space thus filled and emptied. And it will be further observed that the cross-section of the space in the vacuum chamber thus filled and emptied depends upon the difference in cross-section of the chamber itself and the cross-section of the float operating therein, and can be reduced, therefore, only by, causing these two cross sections 0 approximate each other, that is by reducing the width of the space in the chamber around the float. 'And it will be further observed that the reduction of the change of level occurring at each reversal of the valve situation with a float of a given crosssection, can be reduced onl v by reducing the spring resistance against which the float operates.

All these considerations enter into the problem and into the solution of it which is embodied in the structure shown, which will now be described.

In the structure shown in the drawings, 1 is the reservoir or reserve chamber of the device; 2 is the vacuum chamber which is suspended in the reservoir or reserve chamber, 1, having for that purpose at its upper cod :1 horizontal flange, 2, which laps upon an interiorly protruding flange, 1, of the chamber, 1. 3 is a cap member which covers bothchambers and has a flange, 3, which laps upon the margins of the flanges. 1 and 2, which are bound to said flange, 3". by bolts, (1, thereby securing the three principal members of the structure firmly together, suitable packing being interposed between said flanges for makin the joints liquidtight. 4 is a check va ve past which the liquid is discharged into the reserve chamber.

5 is a buoy in the vacuum chamber conthe stitutiug part of the means for alternating the dominance of suction and atmospheric pressure in that chamber, hereinaftcr more particularly described, being the means for reversing the valve situation upon change of level of the liquid in the vacuum chamber. Th s buoy is calculated as to relative weight and volume to balance upon submersion in the liquid fuel to the depth indicated by the dotted line, at, on said buoy, and to have operative buoyancy adequate for overcoming the resistance of the snap-action spring hereinafter described, upon being further submerged to the line, a, and to have operative weight suiiicient for overcoming the resistance of the snap action spring upon being nil-submerged or held up while the ll( uid level falls to the line, p.

The buoy, 5, is suspended in the vacuum chamber by means of a bell crank lcvcr, (1, whose, horizontal arm is in the form of a bail embracing the buoy from one side, and whose vertical arm extends downward from the fulcrum of the lever which is t'ulcrumed on the wall of the vacuum chamber most conveniently at 7 on lugs 7, 7, depending from the cap member, 3. 8 is the snap-action spring which in the construction illustrated. is a compression spring coiledabout a guide link or stem, 9, which is pivoted by its head, 10, at its lower end between lugs, 7-7, which depend rigidly from the cap 3, the upper end of thi stem passingj loosely through the cross-neck conmeeting the two parallel downwardly extending arms. 6, of the bell-crank-lever 6, so that said link or stem 9 has sliding pivotal engagement with said lever arm. The bail member of the bell-crank-lever engages trunnions 5 at opposite sides of the float, the chord of the arc of movement of the axis of the pivotal connection of'the lever to the fioat at the trunnions being substantially vertical, so that the lateral or horizontal displacement of the float in the swing of bell-crank-lever is negligible. 12 is a second bail which embraces the float vertically, extending up around the' lower end of the float and having its ends engaged with the trunnion, 5 by which the bell crank lever is connected to the float, the ends of the bail, 12, being slotted at 12', for their engagement with their trunnions to provide for lost motion between the float, and thereby between the bell crank lever,and said bail, 12, the length of the slots and the extent of this lost motion being designed to be substantially the amount of the throw of the bell crank lever at the ends of its bail member-from th intermediate position at which the snap-spring is alined with the bell crank lever fulcrum, to the limit of the throw caused by the spring in either directioni' from this middle position: The bail 12, is pivotally connected with a lever 13, which extends across under the lower end of the buoy, 5. being itself in the form of a bail, that is. having both ends upturned alongside the buoy, one end being fulcrumcd at H on the wall of the vacuum chamber, and most conveniently on the lower ends of the lugs, 7, 7, depending from the cap 3. The other end which extends up to substantially the same level as the tulcrum,that at the rind-position of thc' throw of the lever is rigidly attached to a substantially horizontal cross-head, 15, which engages looselyg but. substantially without lost motion except as slight pivotal motion is permittcd,-lhc stems of the an! lion controlling valve, to. and the atmos phere inlet valve, 17, controlling respec tively, the suction outlet, 18, and atmosphere inlet, it), formed in the cap member. 3, which closes the vacuum chamber at the top,

For obtaining the desired compactness of construction, so as to have within given dimensions over all a maximum storage capacity of the entire device, and at the same time the possibility of occupying said maximum capacity with the liquid, and adapting the device to deliver minimum charges with maximum Frequency from the vacuum cham be! to the reserve chamber. the construction shown involves certain details requiring particular n'iention.

Space in the vacuum chamber obtained for the springsnap action involving the bell crank lever with its downward cxtcnding arm (3, the spring 8 with its guide and stop and space for the swing or throw of the bell crank lever arm and spring. and all this with the minimum enlargement of the liquid capacity of the vacuum chamber around the float, by forming the vacuum chamber with a pocket or outwardly eX- tending recess 30 at one'side, intruding into the annular space between the outer wall of the reserve chamber and the wall of the vacuum chamber at the upper end of said space at one side, this pocket being radially extended as far as it may be consistently with leaving room for the flange 2 of the vacuum chamber to seat upon the inturned flange 1 of the reserve chamber, as already described. At the opposite side of the buoy, the vacuum chamber is provided with a similar pocket 20 dimensioned radially substantially the same as the pocket 30, but ex tending cirrumfcrentially with respect to the vacuum chamber and reserve ehambera sullicicnt distance to accommodate the atmosphere valve 17, suction valve l6, and the ports respectively which they control, with adequate distance between them to accommodate on the outside of the chamber above the shoulder hereinafter mentioned. the neoessauv fittings for connections with the said ports. The cap member 3 contains the up per part of the vacuum chamber which is reduccd in diameter so as to exceed the di-- amctcr ol' the float only by a sullicient amount to a fl'ord necessary clearance for the free movement oi the latter up and down. This causes the said cap 3 to require at its lower end for its junction with the members 1 and 2 of the structure, the flange 75 abo\e mentioned, hose outer diameter is the same as the outer diameter of the member 1, so that it laps upon the top of the marginal flanges of said other two members i and :2. This flange thus overhangs the pockets iii] and 2 and through it there are Formed the two ports mentioned, viz: suction outlet port 18, atmosphcrc inlet port iii. and said cap is formed with a segmental boss ii of sullicicnt circumtercntial extent to embrace these two ports which are bored in the boss from the upper end. the rods of the bores being plugged as shown, and the bores being tapped laterally for the necessary connections, namely the suction pipe 25 leading to the su tion port, and the atmospheric inlet pipe :18; and the same boss 3* is extended inwardly over the head of the cap to ac commodate the fuel inlet port 21. which is bored into the boss radially to meet a vertical bore from the under side of the cap, as seen in dotted line in Fig. 5. and in full line as to its mouth in Fig. 4. The outer end of this radial bore allords connection l'or the fuel supply pipe 12 which leads l'roin the main tanlt. This boss is extended at 27 over the flange radially, to overhang thc annular interval bctwccn the vacuum chamber and the reserve chamber to all'ord opportunity i'o' atmospheric connection by the duct 27, from thc top of the rcscrvc chamber into the atmosphere inlet passage leading to the vacuum chamber above the atmosphere valve. as has been customary in devices oi this character heretofore, for convenienceol' coimecting both said air passages with a single air pipe 28 which may extend to any desired height or to any desired point at a distance, for the discharge of any vapor ot' the liquid fuel which may be generated in either of the chambers under conditions causing the device to become highly heated.

The operation of the (flevice in view of the construction described and the din'icnsions of the float for operative buoyancy and weight as above described, is as follows:

Assuming the entire device empty and connected with a suction resulting in producing a partial vacuum in the vacuum chamber and causing the inflow of liquid fuel from the main low tank into the 'acuum chamber, the

latter being filled to a level which will first down by the resistance of that spring becomes submerged more deeply notwithstanding it will be found to have been lifted to the position shown in dotted line in Fig. l (but less. it will be observed. than the rise of the liquid level), at \vhieh position the snap-action spring 8 is under the maximumtension. the bell erank lever arm (3 being alined with said spring.

.\t this position the excess oi. rise ol the liquid level from the buoy-lmlancing position indicated by the line, m. over the rise of the buoy during said rise of the liquid will be an amount dependent largely upon the tension of the spring. 8. l'pon .the liquid rising an appreeiable amount above this level. the reaetion ol' the snap-action spring H \vhieh oeeurs upon the lever arm ('r being carried past the position of alinemeut with the sprin will cause the buoy to be lifted to the position shown by line, 1', in Fig. 5, unless the su tion operating upon the at mosphere valve 17 whirh is up to that time. closed. (the suction port and valve being open). is more than can be overeome by the reaction of said snap-artion spring. it is intended that this spring shall be of sneh a tension as to open the atmosphere valve un der conditions of the lowest suction under which the device will properly function or is expected to be operated. or at least. under some relatively low suction. ll the suction is still lower than this. the valve will all the more certainly be opened by the re-artion ol' the spring at the point indicated. lt' the suetiou is greater than the minimum at whieh the snap-action spring is designed to operate for such opening of the valve. thl! snapaetion connection being carried past. t'ie center so that the spring is in position to react. the further movement of the bell crank lever and the further rise of the float will be halted until further rise of liquid in the 'aeuiun chamber. causing deeper immersion of the buoy in the liquid and greater ell'eetive, buoyancy of the float. renders that buoyancy sullieient to overcome the suction on the at mospl ere valve: whereupon. sueh point being passed. the valve will yield and snap open to the full extent. the bell (rank lever completing its swing in the direction for such opening and the float rising to the position shown by dotted line in Fig. 52. which is the high position of the float and the limit of its upward range of movement.

The 'alve situation being reversed by this movement of the float. that is to say. the suction valve being closed and the atmosphere valve opened. the contents of the vacuum'ehamber will descend by gravity past the outlet valve 4 into the reserve chamber 1. As the level of liquid in the vacuum chamber falls. the buoy will fall with the liquid level but substantially half as fast as the level alls. because it will fall against the resistance of the snap-action spring 8, until by this resistance the tloat has become nnsulunergtal by being held up while the liquid level was falling to the line 71 on the lloat; and upon the further fall of liquid an apprta'iable increment below this point, the aeeumulatwl etl'eetive weight of the float overcoming the resistance of the snap-action spring H will earry the bell erauk lever arm (3" past the position of alinement with the spring. and the spring will complete the throw carrying the bail member of the bell eranlt lever down and permitting the. float to deseend to the low-level position shown in tall lines in Fig. 1. again reversing the valve situation. that is. ('losing the atmosphel'e valve and opening the sur-tion valve. lllhllllll'll as in this action the suetion valve will have to be pulled oll' its seat against the uetion. it will be seen that it' the surlion hold on this valve is greater than can be overcome by the reaction of the snapspring H. the descending movement ol' the lloat will be halted at the po ition ol' maximum tension of the spring. that is to say at the point at which the trunnions 5" reach the lower end ol' the lots. 12. in the bail l2, and the parts will there remain until i'urlher l'all ol' lhe liquid level has rendered the tllt'tllYt' weight of the lloat by reason of its further unsulnnergen e. sullieient to overcome this suetion pull. then the action will be completed. the [hall eompleting its deseent to the low limit above mentioned. it, will be seen tla-rel'ore. that the ehange ol' liquid level ori-urring in earh cycle ol' the operation of the device will have a mininnnn determined by the tension of the .\llil|] sprin \Illtl tension being designed. as above stated with reference to a eertain assumed minimum suction operating from the valve: and that it will have a maximum determined by the deepest snlunersion and the highest emersion ol' the buoy. the submer sion for said minimum being when the buoy is positioned at the halting point in the rising movement.-that is. when the snapaetion spring is alined with the bell t'l'illlh' lever arm. tl. a'nd the emersion for said minimum being when the lloal. reaches the halting point in its descent. The maxin'uun change of the level will therefore be the full height of the lloat. while the minimum will be the distance between the lines. 'I/L and p; and that the minimum change of level will' occur under eonditions of low sugion. It will be seen also that the continuance of conditions of low suction while the reserve chamber contains a low reserve supply, that is, anywhere below the bottom of the vacuum chamber. will result in corresponding frequency of repetition of the filling and diseharging action of the vacuum chamber; that is to say, the vacuum chamber will make deliveries at short intermum lifting force, and providing a pocket for this upper end portion of the float entirely above the level of said valved. ports, am] by reducing the diameter of the chamber at this point to the minimum which will accommodate the tloat and avoiding the positioning of any of the operating elements in the space around the lloat which would increase the retplircmcnt of the diameter, for their accommodation, there is provided the shoulder above which all the tluid connections can be made. so that these lluid connections are all brought within a maximum compass over-all which is no greater than required for the chambers without these connections.

'The total result of the several dctail fea tures of construction above pointed out is that the entire device within a given compass over-all in both vertical and horizontal directions has substantially the maximum capacity for the liquid fuel under the conditions under which it may be tilled to maximum capacity. and has a pre-determincd minimum ol' the liquid charge rcceivcd and delivered at each cycle ol the action under the conditions requiring frequency of such action.

I claim:

1. In a vacuum t'nel teed device comprising a. vacuum chamber and a reserve chamber, the vacuum chamber having the following lluid connections. viz: (1) a fuel supply inlet. a fuel supply outlet to the reserve chamber (3) a. suction outlet. and (l) :l] atmosphere inlet; means in the vacuum chamber for alternating the dominance of suction and pressure comprising a buoy mounted for movement by change ol liquid level in said vacuum chamber; a valve device controlling certain of said tluid conncclions. and operating connections to the valvc device from the buoy comprising a snapaction spring. the buoy being positively (Ulk ncctcd opcratively with the valve dcvite in dependently ol' the snap-action spring; said operating connections containing a lost nu tion joint; the snap-action spring being con nccted l'or its tcnsiouing by the mmemcnt ol' the buoy through the range 01' said lost motion.

'1. lit a construction such as dclincd in claim l. the buoy bring pivotally suspended and lnning two connections from its sits ]H'llHlu!l pivots. ouc consisting ot a lcvcr ha\ ing its fulcrum support on the vacuum hamber wall. the snupaclion spring opcratiug on said lcvcr. lhc olhcr cxlcudiug to the valve and containing the lost motion joint 3. in a construction defined in claim 1 foregoing, the buoy being carried by two lifting elements the snap-action spring being connected for operating on one of them, and the other containing the lost-motion joint.

4. In a construction defined in claim 1 foregoing, the buoy being pivotally suspended, and having two connections from its suspension pivots. one of said connections com prising a bail embracing the buoy horizontally. and the other comprising a hail embracing it vertically.

5. In a construction delined in claim 1 foregoing, the buoy being pi votally suspendcd and having two hails for so suspending it.-one bail embracing it vertically and the other bail embracing it horizontally, the vertical hail being positioned and connected to embrace the buoy from below by upward extending arms: whereby the same and the connections therefrom 't'or operating valves are accommotlated in space necessarily providcd tor the liquid. to the avoidance of special provision for such acconunmlatiou.

('1. In a construction delined in claim 1, foregoing. the buoy being pivotally carried, the carrying means comprising two bails. one embracing the buoy horizontally and the other embracing it. vertically from below upward, the operating connections for the last mentioned bail to the valve consisting of a lever t'ulcrumed on the. vacuum chamber wall at one side of the buoy and having its engagement with the valve at the o po it ide. and having a droop to reach the bail connection and accommodate the lloat between its fulcrum and its valve conucction.

T, in a construction defined in claim 1,

l'oregoing. the vacuum chamber being eX- tclulctl and protruded above the top of the reserve chamber with reduced diameter to acconnnodatc the buoy atv the elevated posi tion of the latter. the valved lluid connections being made at the shoulders which results around such extension.

H. ln a construction such as defined in claim l. the vacuum clnunbcr being extendcd and protruded abmc the top of the rescrvc chamber with reduced diameter o no conunodate the buoy al the elevated position ol' the lattcr. valve lluld connections being made at thc shoulder resulting around such extension,

In testimony whcrcoi'. l have hereunto et in) hand this 115th day of .\llglt$t. 1918, nt hi ugo. lllinnis.

('ll,\ HLICS S. BURTON.

Images