US2377251A - Pump - Google Patents

Description

May 29, 1945. c. c. s. LE CLAIR 2,377,251

PUMP

Filed May 22, 1944 2 Sheets-Sheet 1 mula ln o, "am

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My 29, 1945. c. c. s. LE CLAIR 2,377,251

i I PUMP a I .Filed May 22, 1944 2 sheets-sheet 2 Patented May 29, 1945 UNITED STATES PATENT OFFICE PUMP @'ainille' Glare' Slfnklig: Le Clair, Acton',y London,A England Application Mayzz, 1944;,,SerialA ne. sae-,69a nl Greavrliain May 26; 19113V e claims. rel. ree-e411) the leakage of the liquid and, obviously; the

fewer leakage paths there are the better". One of the main leakage paths in a plunger type of pumpris lol'etiveer'lv the plunger and its cylinder or" past its stuflingv box if sileli is tted.

According. to the'pes'ent inventio,. a pump is characterized by the feature that the pumping operations are carried out by at least onehollow collapsible and expansible pumlg'lrgv member arranged within al container for fluids,i meansi for causing the pressure of the fluid within` the container to fluctuate so to cause the collapsing and (or) expanding off the member' in order to change the container volumemof the memben an inlet Val-vey for permitting fluid from a supplyr source to enter the member when the latter is expanded,4

and an outlet valve for permitting fluid, drawn into-the member when the member is expanded, to be dischargedA from the member tor. the` place of use of the fluid when the member is collapsed.

lThe said collapsible and eiiparisible hollow member may take various forms. For example,` tmay consist of a bellows-like device, a-tube of elliptical section, which may either be straight or curved, in the manner of= aBourdolr tube.

By theuse of such a pumpingvmemberinot only i is the principal leakage path eliminated, but stop means may be provided for limiting` its travel or pulsationso that its discharge per` pulsation may be reducedto some predetermined and exceedingly small quantity. In this way, a pump having an extremely small deliveryl can be constructed without resort to parts too Smalll for satisfactory manufacture.

As mentioned above, according to the present invention, the said hollowpumping member is expanded and oollapsedvby uctuating fluid pressure, such as*l hydraulic, actingupon the member, and in order to accomplish this, the meln ber is arranged within a pressure tight container wherein the pressure may be 'i'lctuated through a predetermined range.

Such an arrangement has several advantages. For example, tpermit'sv a multiplicity of collapsible and expansible pumping elements, each capaille of' extremely small discharge; i0- iiehoused within one container, the pressure 'withir'iA which te fleiuaijed by" a'siiigle pump of malicia@7 4israeley Furnier, byl limiting the rangecf against which eaclijindlvidual pumping' element will deliver; maybe-limited te suinesil-fefiguresow that, sliciilil' a delivery pipejlieecnie Clegg-"eliv up;

, for example; hiep-fessure will fiot'loilil'cl` up u'iiiiil' riaeuieialfesplace. A p

iiiadiiliigm' iothesiijmesnsrefeired-i above,

.trisL discharge eerriiulsiieri may be een:

vieil-eil1 by verving' v1li@ design df trie" pumping meneer; Thil-s, ifi trie of a time fleliiisticai Fig.- 2` is' a sectionall View of a modification iii llich the pumping members consist of cu'vd" elliptical tubes.

A number Of hollow, metallic collapsible fnen'lbers I are mounted in'side apressure-tigl'lt c'orltainer 2. 'l'hese collapsible members are in the form of bellows; as .previously mentioned.

f be` adjusted axially' and fixed iii its adl'usiii position livA a lockiiuts: The 'plunge-'ris fclir'iled through which a fresh charge of oil is admitted when the bellows expands, the oil being taken through a. pipe I6 from an oil supply source I1 external to the pressure tight container 2 but adjacent thereto and integral therewith.

The fluctuating pressure is provided by a single pump, hereinafter called the main pump, comprising a plunger I8 operatingpin a cylinder I9 integral with the container 2 and oil supply source I1.

This pump cylinder I9 is provided with an inlet port 20 adapted to be uncovered by the plunger I8 at the end of its outward or suction stroke. There is no discharge Valve in the ordinary sense of the term, but a relief valve 2| is fitted between the pressure-tight container and the oil supply source I'I such that should the pressure in the former rise beyond a predetermined figure, the valve allows any excess oil to return to the supply source. The pump plunger is pressed outwards by a spring 22 and operated by a rotating shaft 23 and eccentric or cam 24.

At the outward end of the inlet stroke of the plunger I8, the inlet port 2U is uncovered and oil from the supply source flows into and charges the cylinder I9. On its inward or discharge stroke the plunger rst closes the inlet port 20 and then forces the entrapped oil forward through a port 25 into the pressure-tight container 2, raising the pressure in the container andat the same time collapsing all the collapsible bellows I and discharging a predetermined quantity of oil from each. If, as will generally occur, this takes place before the main pump has finished its stroke, any excess oil'delvered by the latter will pass through the said relief valve 2| back to the supply source I'I. On the next suction stroke of the main pump this amount plus the amount discharged by the bellows will pass once again through the inlet passage 2U into the pump cylinder and the cycle will be repeated.

The construction shown in Fig. 2 is similarto that shown in Fig. 1 in that it comprises a pressure-tightcontainer 2A which is closed by a cover 1A and is integral with an oil supply source IIA. A hollow housing 6A is attached to the cover 1A and spring-urged inlet and outlet valves IA and |3A are also fitted. The outlet valves provide communication with outlet pipes I4A leading to the place of use of the oil and the inlet valves connect with the inlet pipes IBA leading from the supply source I1A. A relief valve 2IA is also fitted. Instead of bellows devices,` however, use is made of curved metal tubes 26 of elliptical sectionV resembling Bourdon tubes. The upper end of each tube communicates with the passage IIA in the housing BA while its lower end is closed by a cap 21. As in the preceding construction, the apparatus is provided with a main pump comprising a plunger IBA slidable in a cylinder ISA, an inlet port A providing communication between the interior of the cylinder and the oil supply source I'IA when the plunger is at the end of its suction stroke, and an outlet port A providing yconstant communication between the cylinder and the pressure-tight container 2A. The plunger is operated by a cam or eccentric 24A mounted on arctating shaft 23A. On the discharge stroke of the plunger IBA, oil under pressure is forced from the cylinder ISA through the port 25A into the container 2A. The pressure of the oil in the container alters the section and shape of, and collapses, the tubes 26 thereby forcing oil from the tubes into the hollow interior of the housing 6A, andA thence past the outlet valves I3A through the discharge pipes I4A to the place of use. Towards the end of the discharge stroke of the plunger IBA after the tubes 26 have collapsed any excess oil delivered is discharged back to source via the relief valve ZIA. When the plunger I8A is moved in the opposite direction, however, the pressure immediately drops, the tubes 26 again expand and oil is drawn from the oil supply source ITA through the pipes ISA and past the inlet valves I5A into the interior of the housing 6A and into the tubes 26 to replace that previously expelled from the latter. At the end of the suction stroke, the inlet port 20A is once more uncovered and the pump chamber is replenished as previously explained.

The tubes 26 could be straight instead of being curved. Whatever form of pumping member is used, however, it is desirable that the whole of the internal container volume of the member with its associated passages from the inlet valve to the discharge valve should have an upward trend towards the latter so that any air which may gain admission can find its way past the discharge valve by levitation.

Stop means (not shown) may be provided for limiting the collapsing of the elliptical tube and such means may be adjustable.

In the construction shown in Fig. 1, the stop means 4 may be external to the collapsible members, limiting their free shape, instead of limiting their collapsed shape internally as shown.

The main pump may draw fluid from, and discharge fluid past the relief valve 2I or 2IA back to, a supply source separate from that from which the collapsible members draw their supply, and the main pump may itself be separate from either the supply source or the pressure container and connected thereto by pipe connections.

It will be understood that the pump may be constructed in the form of a multiple pump unit as described above, which comprises two or more collapsible and expansible or flexible pumping members, or it may comprise a single pumping member. A multiple pump unit may comprise one or more main pumps and the pumping members may be arranged in the same or in indi- Vidual pressure-tight containers.

I claim:

1. A pump comprising a pressure type container for fluids, at least one hollow collapsible and expansible pumping member within said container, a source of fluid to be pumped, at least one main pump which receives fluid from said supply source and forces it into said container so as to cause the pressure of the fluid in said container to fluctuate thereby causing said member to collapse and expand to change its container volume, at least one hollow housing associated with said container having an inlet port and an outlet port, check valves controlling the ow of iiuid through said ports, said member being mounted to communicate with the interior of said housing, and means connecting the inlet port with said fluid source.

2. The combination set forth in claim 1 wherein said hollow collapsible and expansible pumping member consists of a bellows device.

3. The combination set forth in claim l wherein said hollow collapsible and expansible pumping member consists of a, tube of elliptical section.

4. The combination set forth in claim l including stop means positioned to limit the extent of movement of said pumping member, so that its discharge per pulsation may be reduced to some predetermined and small quantity.

5. The combination set forth in claim 1 wherein said hollow collapsible and expansible pumping member consists of a bellows device, and including stop means to limit the extent of movement of said bellows device.

6. The combination set forth in claim 1 wherein said hollow collapsible and expansible pumping member consists of a bellows device, and including adjustable stop means to limit the extent of movement of said bellows device to any desired and predetermined amount.

7. The combination set forth in claim 1 wherein said source of uid is in communication with the main pump cylinder through an inlet port controlled by the pump plunger, and wherein the main pump cylinder 1s in constant communication with said container through an outlet port.

8. The combination set forth in claim l wherein said source of fluid is in communication with the main pump cylinder through an inlet port controlled by the pump plunger, and wherein the main pump cylinder is in constant communication with said container through an outlet port, and including pressure-relief means in said container to allow any excess fluid to be returned to said source whenever the pressure in said container rises above a predetermined value.

CAMILLE CLARE SPRANKLING LE CLAIR.

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