US2351304A - Fluid transfer apparatus - Google Patents

Description

June 13, 1944. w. T. TABB 2,351,304

FLUID TRASFER APPARATUS original Filed oct. '22. 1940 Patented June 13', 1944 UNITED STATES PATENT ortica FLUID TRANSFER. APPARATUS Warner T. Tabb, Brooklyn, N. Y., assigner to Eisemann Corporation, a corporation of Dela- Ware Original application ic'tober 22, 1946, Serial No.

362,179. Divided and this 17, 1942, Serial No. 435.117

(ci. ies-eos) Y y, p

substantially horizontal and the pump chamber 8 Cla.

' parts frictional engagement between which is relatively minimized thus reducing tendency of wear which might eventually require replacement or repair, can be readily and easily assembled and disassembled, is emcient in operation to transfer duid eectlvely at a relatively uniform rate and is capable of eilicient high frequency operation;

and structural embodmentsof such apparatus which can readily and economically be made and assembled in mass production while assuring efficient use and operation thereof.

More specific objects of the invention are the provision of such apparatus characterized by a pump chamber formed by cooperation of a casing and a diaphragm having lateral rigidity and certain spring characteristics with diaphragm biasing leaf-like spring structure having certain spring characteristics mounted in the chamber in a manner to provide certain net spring characteristics for combined diaphragm and spring construction; and to provide such apparatus wherein the mounting and characteristics of said diaphragm structure are such that an outwardly projecting diaphragm operating member mounted on the diaphragm is properly and emciently guided in its operation. without necessitating use therefor of bearing supports or like guiding means which might tend to introduce undesirable problems of construction, manufactureand wear; and which assure emclent operation of said apparatus by mechanical means that may tend in operation to flex said diaphragm only inwardly.

Another object of the invention is the provision in such apparatus of suitable fluid passages past a diaphragm biasing spring disc structurewithin vthe pump chamber of such a diaphragm pump.

either through the diaphragm or around the periphery thereof, which assures eilicient use and operation thereof.

A further object of the invention is to provide such diaphragm pump structure which, though adapted to enect operation when mounted in a position other than with the diaphragm thereof application March thereabove which may be termed the vertical .pump position," it is particularly eiiective for continuous emcient operation when mounted in such vertical pump position, the casing structure deiining at least a portion of the pump chamber. the inlet and outlet passages communicating therewith and valves structures inthe passages being such and cooperating in a manner as to assure effective escape of lndrawn relatively light foreign fluid, such as air or gaseous liquid when a liquid, e. g. hydrocarbon fuel, is being transferred by the pump.

Other objectsl of the invention will in part be` obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts, which will be exemplified in the construction hereinafter set forth and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing, .in which:

Fig. 1 is a top plan view of one embodiment of the apparatus of the present invention; and

Fig. 2 is a sectional view takenon line 2-2 of lFig. 1.

Various diaphragm pump structures have been` proposed for use in transferring uids, both gas-V eous and liquid. For example, such structures have been proposed for use in both mechanical and electrical gasoline injection systems as wellA as for use in fuel supply systems of internal combustion engines of the Diesel type, oil burners and the like. Many of such structures, however,l

have been of such construction as to require extremely careful and costly machining and fitting of parts, treating of material to harden frictionally engaging parts, and costly and frequently inl,

of packing to prevent leak-2.v

complicated making assembly and disassembly difficult, subject t0 Weaillof 1.' frictionally engaging parts making repair orfre-' Y placement of parts eventually necessary, andiinemcient provisions age; and have been emcient and non-uniform in operation. Further, `such structures have been such as to make their use in systems requiring high speed operation, for example fuel supply systems for internal combustion engines, extremely uncertain and unsuitable.

These and other difficulties are eiiciently alleviated by the apparatus of the present invention willen/ns' Been found to be highly satisfactory for use, by way of example, in fuel supply systems for Diesel engines. The diaphragm pump structure of the invention has no working parts characterized by frictional engagement oi!- guiding bearings, other than a roller, if desired, used I as a cam follower to impart movementto a diaphragm operating member vor rod. 'Ihe diaphragm operating member is preferably anchored to the diaphragm to project outwardly therefrom V the roller I9 carried thereby to permit without contact free reoiprocation of the latter therethrough.

The diaphragm I2 and the casing Il cooperate -to provide a pump chamber 21 on the side walls of which are formed a plurality of circumferentially spaced seats 2628v providing al plurality of intermediateiiuidpa'ssages 294-29 past the seats 28-28. A diaphragm biasing leaf-like spring structure 30, preferably formed of one or more laminae of sheet steel of disc configuration is mounted in the chamber 21 with its periphery supportedk on the seats Z8-28 preferably with at least small lateral clearance. yThis spring structure 30 is provided with a central aperture 3| which engages over theinner end 22 of the operating rod and the structure mounted thereon prefand forms a biasing abutment for the central portion of the diaphragm structure to obtain the desired biasing action. The diaphragm structure has certain spring characteristics as does the spring structure and these are so correlated as to give net spring characteristics for the combined spring and diaphrI .m structures as to make for desired action.

Inlet and outlet passages having valves therein are provided in the casing to communicate with the pump chamber. The apparatus may be u'sed efficiently in a variety of positions but preferably is mounted vertically with the passages communicating withI the chamber through the top of the casing and the valves therein positioned angularly with respect to each other. The portions of the seats of said valves, preferably of the check valve type, nearest each other are at highest elevation with'v that of the outlet `valve above that of the inlet valve. This permits effective escape at each pump cycle of indrawn relatively light foreign fluid, such as air and gaseous fuel when liquid fuel is being transferred, whereby tendency to build up in the pump chamber a body of such foreign fluid or gaseous matter that might eventually prevent eflicient operation of the pump is eliminated.

Referring tothe drawing like numerals refer to like partsthroughout. A base member or plate I is provided with an annular seat I l upon which seats the periphery of a diaphragm I2. The diaphragm I2 may comprise one or more laminae of sheet steel and preferably has a gasket ring I3 located on either side of the periphery thereof. A casing I4 of general cup-shape and preferably domed at the top has an annular seating surface I5 adapted to cooperate with theV seat II on the baselil to clamp the diaphragm I2 and gaskets I3, I3 therebetweeen in a fluid-tight manner,

erablyrecelving the nut 23 with at least'small lateral clearance at points of greatest lateral dirnensionwith the portions adjacent the aperture bearing against the washer 24 to form a biasing abutment for the diaphragm structure.

This spring' structure 30 may be cupped and positioned as shown in the drawings. Obviously i the position of the spring lstructure 30 may be reversed provided the seats 28-28 and the diaphragm structure or anchorage structure of the operating rod are suitably altered to accommodate such reversal. The position and shape of the spring structure will be largely dictated by the results desired, the dimensions such as relation of thickness of spring structure to diameter, degree of initial cupping, etc. Forsome purposes substantially fiat disc spring structure may be desirable, such as where the diaphragm is to be flexed in opposite directions from an intermediate y neutral position which may be determined by a 40 in the least strain on the diaphragm.. 'I'he use of a fiat spring structure assures compactness of pump construction.

suitable screws Iii-I6 being used to clamp the i parts together.

An operating member or a rod I'I` is anchored centrally to the diaphragm I2 ,to project outwardly therefrom. This member preferably comprises a fork I8 between the legs of which is rotatably mounted a roller I9 constituting a cam follower adapted to ride on the outer surface of. a cam 20. A flange 2| at the base of the operating member I-'I provides a bearing shoulder for a central portion of the diaphragm I2 and an inner.

stud end 22 thereof projects through a central aperture in the diaphragm I2jand is externally threaded to receive a nut 23 between which and the flange 2I is clamped the diaphragm structure with an interposed washer 24 and suitable gasketA rings 25, 25.

The base member l0 is provided centrally with A fiat or initially uncupped diaphragm, such as that shown by way of example in the drawing, has certain well dened characteristics as a spring in and of itself. These are such as may tend to result in excessive pressure of the cam follower against the cam in the positions of maximum ilexure of the diaphragm, such as the innermost position of the diaphragm and associated parts of the structure shown in the drawing. Further in such a structure those characteristics may tend to prevent the cam follower from effectively following the cam in the outermost position of the diaphragm. The plotted curve of those diaphragm characteristics is found to be of great curvature indicating that the rate of change of positive and negative pressures may be of an objectionable degree under certain conditions making it advisable to use very small diaphragm deflections.

This may be compensated for or effectively corrected by the use of `an initially cupped spring -a hole 26 larger than the operating rod I1 and 75 pump 0I1Sfruti0n While making for simple and chamber on the outlet compact pump construction assures long life for the diaphragm and its operating mechanism and eillcient pump performance with the use oi diaphragm and biasing spring structure of simple design.

The casing Il is provided with a pair of opposed bosses 32 and 33 having respectively internally threaded recesses 34 and 3i to receiveiiuid supply municating with the pump chamber 21 through:

suitable valve structure located therein. These valves preferably are of they check valve type so mounted in their respective chambers as to permit uid to flow into 'the pump chamber 21 from the inlet side and iiuid to ow out of lthe pump side,l as indicated in the drawing.

The check valve 12in the inlet chamber 31, as is more fully described in my copending application Serial No. l362,180, filed October 22, 1940, comprises a sleeve-like cage 43 having a seat t4 formed thereon against which is biased a valve plate 45 by a leaf-like spring structure 46 centrally apertured to receive a stud structure 41 preferably anchored to the valve plate d5, with spacing means B8 interposed between e the valve plate structure t5 and the spring structure t6 to form opposed abutments whereby the valve plate can be biased to its seat and the parts of the valve assembled in the cage #i3 vby a splitring i9 seated within a'groove in the cage Q3 and bearing against peripheral portions of the spring structure B6. The base of the cage t3 is machined out at 50 to forin a tapered throat for the valve port.

The check valve in the outlet chamber d@ is similar in construction to the check valve in the inlet chamber'31 except perhaps in one particular. The check valve on the inlet side is preferably provided with a hole El through the cage d3 which communicates with the annular recess adjacent to and surrounding the valve seat on the chamber side thereof at substantially its highest point as showii. Such a hole having no purpose in the check valve or the outlet passage may be omitted. In the crown of the domed chamber wall adjacent the tapered throat 5B of the outlet valve cage :43 at its point of highest elevation is machined a way 52 to cooperate with the surface of -thethroat 50 of the outlet valve,l

the upwardly inclined inner surface of the pump chamber 21 andthe hole El, to provide an escape Way for relatively light foreigniiuid that may be drawn into the pump chamber with the fluid being transferred, for example, air and fuel fumes, when hydrocarbon fuel is being transferred. This will prevent undue accumulation of gaseous medium in the transfer pump chamber which might tend to affect eillcient operation thereof and possibly prevent in the ultimate any transfer of fluid.

Pulsation eliminators may be provided in the inlet and outlet passages by forming recesses 53,- 53 in the caps 38 and si and trapping a body of air therein by flexible diaphragms 54, 54 of resilient material, such as neoprene, each held in position on an annular seat 55 by a press-fitted ring 56.

Vphragm causes the outlet valve to unseat and By 'way of example the transfer pump ofthe present invention may be mounted by means of mounting ears 33-33 on the basemember I0 upon the case of a high pressure' injecting apparatus for feeding fuel to a Diesel engine. Such injecting apparatus may comprise a plurality` of high pressure injecting pump devices, one for each cylinder of the engine, all operated by acommon cam. The circumferential surface of Athis cam may be provided with lobes equal in number to the number of high pressure injecting devices so that each revolution of the cam, such as 20, will result in a number of complete trans fer pump cycles equal to the number of high pressure injecting devices each of which is operated during one cam revolution. Such operation obviously will be of very high frequency A. and it has been found that the apparatus of the present invention with the provision of diaphragm travel offabout .0125" on each side of the neutral position will perform its functions under such conditions in a highly satisfactory manner. It will further be noted that with such a mounting of the device all of the parts thereof can easily and readily be assembled from the top.

In operation when the koperating rod is lifted upwardly bya cam the resultant inward flexing of the diaphragm against the biasing action of the springstructure minimizes the space-of the pump chamber and when the cam permits theoperating rod to be moved outwardly by the biasing spring structure partial vacuum is created in the pump chamber producing a differential in pressure on opposite sides of the inlet-valve suilicient to open the same and cause uid td ow into the pump chamber. When the operating rod is again moved inwardly the inlet valve automatically closes, and pressure built up in the pump chamber by inward flexing of the diafluid to be delivered through the outlet passage from the pump chamber'. When the biasing spring structure is againv permitted to move the diaphragm outwardly the outlet valve automatically closes and the cycle is then repeated.

It will thus 'be seen that the objects set forth aboveare efficiently attained by apparatus oi' the present invention and since certain changes may be made in the above construction and difi ferent embodiments or the invention could be made without departing from the scope thereof, it is intended that all matter contained. in the above description or shown in the accompanying drawingI shall be interpreted asillustrative and not in a limiting sense.4

It is also to be understood that l-the following claims are intended to cover all of the generic and specilcfeatures of the invention herein described, and all statementsy voi? the scope of the` invention whichas a matter be said to fall therebetween.

Having described my invention what I claim as new and desire to secure by Letters Patent, is:

1. Fluid transfer apparatusv comprising, in coma casing, a exible diaphragm peripherally supported on said casing and cooperating therewith to form a pump chamber above said diaphragm, inlet and outlet passages in the top of said casing, valves located in the passages with of language, might I the seat of the inlet vvalve inclined with respect to a horizontal plane, the portion of said inlet valve seat'at highest elevation being adjacent said outlet valve with at least a portion oi the latter' being located above the portion of the inlet valve which is at highest elevation whereby indrawn 'relatively light fluid or gases that would otherwise tend to collect immediately below said inlet valve will pass to said outlet valve and escape therethrough, there being no intervening structure to interfere with such flow.

2. Fluid transfer apparatus comprising, in combination, a domed casing, a flexible diaphragm peripherally mounted on said casing, inlet and outlet passage through the top of said casing, inlet and outlet valves respectively located in said inlet and outlet passages, said diaphragm and said valves cooperating with said casing to denne a pump chamber above said diaphragm, the portions of said chamber immediately adjacent said inlet valve having defining surfaces inclined with respect to a horizontal plane upwardly toward said outlet valve, so that relatively light fluid or gases that would tend to co1- lect in said chamber adjacent the inlet valve will pass upwardly therefrom toward said outlet valve and escape therethrough.

3. Fluid transfer apparatus comprising, in combination, a domed casing, a exible diaphragm peripherally mounted on said casing and cooperof hole extendingv therethrough from the chamber side of the valve substantially at the point of highest elevation, and the chamber side'of the cage of the outlet valve and the chamber wall pointsin the top of said casing structure, a valve located in the inlet ,passage having a seat, said outlet passage having a throat a portion of the margin of which is located at an elevation higher than the elevation at which the highest portion r of said seat is located, said casing structure berelative elevation than that of the outlet valve, y

the wall of said chamber and valves structures being so shaped and constructed as to provide an upwardly inclined way from that portion of the inlet valve on the chamber side at highest elevation to that portion of the outlet valve at highest elevation.

4. Fluid transfer apparatus comprising, in combination, a domed casing to define the upper portion of a pump chamber, inlet and outlet passages in the top of said casing converging down- I wardly toward each other, valve cages mounted in said passages substantially transversely thereof with that in the inlet passage having a downwardly facing seat and that in the outlet passage an upwardly facing seat at a relatively wardly toward each other, valve cages mounted in said passages substantially transversely thereof with that in the inlet passage having a downwardly facing seat and that in the outlet passage an upwardly facing seat with the inlet valve seat nearer the chamber wall than the outlet valve seat, the cage of the inlet valve having a tween the highest portion of said seat and the mentioned portion of the margin of the throat of said outlet passage being so shaped and constructed as to provide for free upward passage of l indrawn relatively light foreign fluid and resultant escape of substantially all thereof.

7. Fluid transfer apparatus comprising in combination, a domed casing providing a pump chamber, inlet and outlet passages communicating to the pump chamber through the top of said casing, na valve located in the inlet passage having a seatjin the throat thereof, said outlet passage having a throat a portion of the margin of which is located at an elevation higher than the elevation at which the highest portion of said seat is located, said casing structure between the highest portion of said seat and the mentioned portion of the margin of the throat of said outlet passage being so shaped and constructed as to provide an upwardly inclined wayvfrom the former to the latter for escape of indrawn relatively light foreign fluid.

8. Fluid transfer apparatus comprising, in combination, a domed casing, a flexible diaphragm peripherally mounted on said casing and cooperating therewith to form a pump chamber above said diaphragm, inlet and outlet passages leading to and from the chamber through the top of said casing and converging inwardly toward each other with the outlet passage having a throat, valve seats and cooperating valves in said passages disposed substantially transversely thereof with the highest portion of the seat of the inlet valve located at a lower relative elevation than a portion of the margin of the outlet passage throat, the wall of said chamber between the passages and associated valve and throat structures being .so shaped and constructed as to provide an upwardly inclined way from that portion of the inlet valve on the chamber side located at highest elevation to that portion of the margin of the throat of the outlet passage located at higher elevation.

. WARNER T. TABB.

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