US1934740A - Pump - Google Patents

Description

B. F. SCHMIDT Nov. 14, 1933.

PUMP

Filed Sept. 28, 1951 3 Sheets-Sheet l gvmge'ntoc B. F. SCHMIDT Nov. 14, 193s.

PUMP

Filed Sept. 28. 1951 3 Sheets-Sheet 2 B. F. SCHMIDT Nov. i4,

PUMP

Filed sept. 28, 1931 )Patented Nov.. i4, 1933 Benjamin F. sont, Les cies, cam.

Application September 28, 1931 Serial No. 585,42?

is claims. (ci. ies-2te) This invention relates to, pumps and particularly pertains to said proof pumps of the type including a piston reciprocable in a body of mercury or other protective liquid of greater density than a fluid to be pumped, and more especially appertains to improvements in pumps of the character set forth in my copending applications for United States Letters Patents, Serial Number 465,835, led July 7, 1930, and Serial Number 498,943, led November 29, 1930.

An object of the invention is to provide a pump of the reciprocal piston type in which the piston is so arranged as to be protected by a body of P liquid, such as mercury, entrapped within the pump casing in such manner as to inhibit the passage of sand or other granular substances contained in the fluid being pumped, between the contiguous wearing surfaces of the piston and the walls of the pump, and whereby the discharge 0 of sand or other granular solids associated with the iiuids in the pump will be facilitated.

Another object is to provide a pump of the above character which is so formed as to maintain a protective liquid in and around a hollow or tubular pump piston in substantially predetermined proportions interiorly and exteriorly thereof, and whereby the possibility of loss of the protective liquid during operation of the pump will be obviated.

With the foregoing objects in view, together with such other objects and advantages as may subsequently appear, the invention resides in the parts and in the combination, construction and arrangement of parts hereinafter described in the accompanying drawings, in which:

Figure 1 is a viewA in vertical section partly in elevation of a pump and with parts broken away, illustrating one embodiment of the invention, the pump piston being shown in its lowermost position; r

Figure 2 is a diagrammatic view`of the pump shown in Figure 1 as seen in section and elevation on a reduced scale for illustrating the mode of operation of the pump;

Figure 3 is a view similar to that of Figure 2, but showing the pump piston in an elevated position;

Figure 4 is a detail in cross section as seen on the line 4-4 of Figure 1;

Figure 5 is a detail in cross section as seen on the line 5-5 of Figure 1;

Figure 6 is a detail in cross section asseen on the line 6-6 of Figure 1;

and claimed and illustrated by way of example.

Figure 7 is a detail in vertical section as se on the line 7-'7 of Figure 3; 5

Figure 8 is a detail in cross section taken on the line 8-8 of Figure 7 Figure 9 is a detail in cross section taken on d@ the line 9 9 of Figure '1;

Figure 10 is a perspective view with parts broken away depicting the portion of the pump shown in Figure 7;

Figure 11 is a view in vertical section of a pump 65 with parts broken away illustrating another form of the invention, and showing the pump piston in its lowermost position;

Figure 12 is a diagrammatic view in section and elevation of the pump shown in Figure 11 70 on a reduced scale showing the piston in its lowermost position;

Figure 13 is a View similar to Figure 12 showing the piston in an elevated position;

Figure 14 is a detail in cross section taken on 75 the line 14-14 of Figure 11;

Figure 15 is a view in elevation taken on the line 15-15'of Figure 11;

Figure 16 is a view in vertical section as seen on the line 16-16 of Figure 11;

Figure 17 is a view in horizontal section taken on the line 17--17 of Figure 11.

Referring to the drawings'more speccally, in which corresponding reference characters indicate corresponding or similar Aelementsl in the several views, A indicates a pump barrel which has a lower end wall 41 formed with an intake opening 42; the end Wall 41 being here shown as comprising a plug which is threaded into the pump barrel, and from which bottom wall 41 is erected-an intake tube B, the lower end of which 'is shown as screwed into engagement or other- Wise joined with the wall or plug 41. The tube B projects upwardly into the pump barrel A and terminates in suitable spaced relation from the bottom wall 41, and has' its outer periphery spaced from the inner periphery of the pump barrel in concentric relation thereto; the barrel A and tube B being cylindrical in form.

Reciprocally mounted within the pump barrel A 10g and surrounding the intake tube B is a tubular piston C carried on a pump rod D; the interior of the piston being in open communication at the lower end thereof with the interior of the pump barrel. The tube B and piston C are of such lengths relative to the elected length of stroke of the piston that the lower end portion of the latter is maintained at all times during operation of the pump interposed between the tube B and the barrel A, and the piston is so arranged that when in its lowermost position, its lower end will be disposed adjacent the bottom wall of the pump barrel.

Entrapped within the lower portion of the pump barrel is a body of suitable protective liquid F having a density or specic gravity exceeding that of a fluid to be pumped and sufiicient to float granular solids associated with such uid, and which liquid F is insoluble in the fluid being pumped. For the purpose of brevity, this liquid F will be hereinafter referred to as mercury.

The mercury body F is confined in the space between the tube B and the pump barrel A and extends on opposite sides of the lower portion of the piston C to produce a mercury column G interiorly of the piston occupying a space between the lower portion of the piston and the tube B, and also to afford a mercury column H exteriorly of the piston occupying the space between the lower portion of the piston and the pump barrel A.

The relative levels of the mercury columns G and H will vary during reciprocation of the piston by reason of displacement of the mercury body during movement of the piston, but the present invention contemplates the provision of a means or construction whereby the relative volumes of the mercury columns G and H will be maintained substantially uniform or will be caused to assume denite relations from time to time in event vof any variation in their relative volumes, and whereby the levels of the mercury columns G and H will be caused to lie on substantially predetermined planes when the piston is disposed in its lowermost position.

A seal E is provided between the piston and the pump barrel which may be of any suitable construction. l

In the form of the invention shown in Figures l to 10 inclusive, the upper end of the intake tube B is fitted with a normally closed upwardly opening valve J, here shown as comprising a ball 43 arranged in a cage 44 carried on the upper end of the tube B, and which ball normally rests by gravity on a seat 45 whereby communication between the intake tube B and the interior of the piston C is normally closed on down stroke of the piston and when the piston is at rest, but which is open on up-stroke of the piston to admit fluid being pumped to the interior of the piston.

The upper end of the piston C is formed with a passage 46 which leads from the interior of the piston to the exterior thereof, and which passage is tted with an upwardly opening valve K here shown as comprising a ball 47 which normally rests on a valve seat 48 thereby normally closing the passage 46 during up-stroke of the piston and when the piston is at rest, but which ball moves off the seat to open the passage 46 when the piston is moving on its down stroke.

The piston C includes a cylindrical shell 49 having a threaded tubular extension 50 on its lower end, on which is mounted the seal E here shown as comprising a series of cup leathers 51 held in place by crowding rings 52 screwed onto the threaded extension 50. The cup leathers are so arranged that on up-stroke of the piston they will effect such close contact with the walls of the pump barrel A as to effect lifting of the column of liquid in the pump casing thereabove. The column H of the mercury extends above the cup leathers 51 a distance exceeding the length of stroke of the piston and is carried with the latter during the stroke thereof so as to maintain a body of mercury between the liquid being pumped and the piston cup leathers 51, and the mercury column His of such length in excess of the length of the piston stroke that such volume of mercury as may pass the cup leathers will not lower the level of said mercury column H to a point such that liquid in the pump barrel above the mercury column will be lowered sufficiently to contact the portion of the pump barrel contacted at any time by the cup leathers.

The principal feature of the present invention resides in the provision of an automatically actuated valve structure in the piston for controlling the relative volumes and levels of the mercury columns G and H, and which structure, in the form of the invention shown in Figures 1 to 10, inclusive, embodies an annular valve L interposed between the intake tube B and the piston shell 49 in circumferentially spaced relation thereto and mounted for vertical reciprocal movement independent of the piston.

The valve L when in its uppermost position abuts at its upper end against the under side of a partition M extending between the intake pipe B and the piston C and. carried by the latter, and which partition is formed with ports 53 aording a communication between the spaces within the piston y on opposite sides of the partition and which ports are arranged to be closed by the valve L when the latter is in its uppermost position. The lower end of the valve L is tapered as indicated at 54 and is designed when the valve is in its lowermost position to contact a beveled seat 55 formed on the inner periphery of the piston shell 49 to eiect closure of the upper ends of a series of passages 56 leading downwardly from the seat 55 and opening exteriorly of the shell 49. The valve L is thus double acting and is operable on reciprocation thereof, as will presently be described, to open and close the ports 53 and passages 56.

Extending upwardly from the upper margin of the annular valve L is a pair of stems 57 which pass through a pair of diametrically opposed ports 53 and the upper ends of which stems are afxed to the lower end of a tubular sleeve 58 which encircles the intake pipe B in spaced relation thereto and the exterior of which is spaced from the interior of the piston shell 49. The sleeve 58 is formed of a metal, such as iron, which will float when sulciently submerged in mercury; the sleeve thus serving in effect as a oat to maintain the valve L in its uppermost position when the mercury column D in which a portion of the sleeve is submerged is of such height Within the piston as to effect flotation of the sleeve. The sleeve 58 and valve L and stems 5'1 are formed of such weight and are arranged in such relation to the column G of mercury within the piston that when the level of the mercury is at a predetermined point when the piston is in its lowermost position, as indicated for example by the line a-a in Figure 2, the valve L will be disposed in its lowermost position, and also such that when this level of the mercury is slightly increased, as indicated by the line b-b in Figure 2, the valve Ll will be elevated to its uppermost position.

The sleeve 58 is formed with a series of openings 59 extending therethrough circumferentially thereof at a point approximating what may be termed the high level of the mercury column G indicated by the line b-b in Figure 2 for the purpose of decreasing the buoyancy of the sleeve when the latter is submerged in the mercury such distance that the mercury will enter the openings 59.

In order to eflect a seal between the partition M and the intake pipe B a packing 60 is carried by the-partition and arranged to slidably contact thereon; the upper margin of the valve N being beveled as indicated at 62 to conform to the seat 61. its seated positionby reason of its being buoy.-

ant in the mercury column H but to insure rapid seating of the valve a plurality of springs 63 are arranged to bear upwardly against the lower end thereof.

As a means for facilitating assemblage of the valve structure just recited the shell 49 is formed with an intermediate section O the lower end of which is screwed into engagement with the upper end of the extension 50 and the lower portion of which section isireducedin external diameter to provide an annular space to accommodate the valve N and which section O is provided with the passages 56 and the valve seats 55 and 61.

The upper end portion of the section O is screwed into the lower end of the shell 49 proper and has its upper end arranged to bear against the upper side Xof the partition M to hold the latter in position against a shoulder 65 formed interiorly of the shell.

On downstroke of the piston, the .valve J is closed and valve K opens to permit fluid therebeneath to flow upwardly through the passage 46 into the pump barrel above the plunger where it is entrapped and subsequently elevated and advanced to discharge by the repeated upstrokes of the pump piston in the manner common to pumps of the reciprocal piston type. 'As the piston moves downwardly, it displaces a portion of the mercury body F, thereby causing the mercury column G to rise in the piston around the tube B so that the level of the mercury column G will then be spaced above the level of the outer mercury column H; the mercury flowing past the valve L and through the. ports 53 by reason of the valve L then being in its lowermost position. If perchance no mercury was added to the column G on the previous upstroke of the piston the valve L will remain in its lowermost position throughout the downstroke `of the piston by reason of their then being insumcient mercury in the column G to float the sleev'e 58, but in event of the volume of the column G being increased, which generally occurs on each upstroke of the piston, the valve L will be elevated relatively to the piston the moment that sufiicient mercury has flown through the ports 53 to float the sleeve 58 then closing the ports 53 and openingl the upper ends of the passages 56 which condition will endure when the piston reaches its lowermost position as shown in Figures 1 and -2. The level of the column G will then be slightly above normal.

In event an' amount of mercury has been added to the column G on the upstroke of the piston in excess of such asv will act to effectclosing of the ports 53 by the valve L, such amount will be forced back into the outer mercury column H as the piston C approaches the terminus of its down stroke through the passages 56; -the partition M then acting as a plunger to force the excess mercury through the passages 56. The

The valve N is normally maintained in valve N willl then readily open under the pressure of mercury forced through the passages 56, and closing when this pressure terminates..

It should be noted that the displacement of the mercury of the body F and the consequent rise of the level of the column G, takingplace at the end of the down stroke of the piston C,

will not cause the valve L to float and assumeits uppermost position closing the-ports 53 in the partition M, unless an amount of mercury has leaked into column G. Consequently, any leakage into column G such as will raise the level above that ordinarily reached at the end of the downstroke of piston C may be utilized to float valve L into position closing ports 53, provided said valve will close said ports and the leakage will be returned to column H, before the levels of the columns are varied toy an extent such as would expose the sand entrapped on the tops of the columns to the workingsurfaces of the pump piston and barrel.

When the valve L closes the ports 53, the partition M entraps the portion of column G below 'it and acts as a piston, exerting such pressure on the mercury thus entrapped, that as the piston C nears the end of its downstroke, the mercury in an amount equivalent to the leakage from column H will be forced through ports 56 back into column H. The pressure of the mercury passing through ports 56 will vopen the valve N. The column G in thus being approximately restored to its normal level permits valve L to gravitate to its lowermost position closing the ports 56, when the piston begins its upstroke. Since the valve L maintains its lowermost position closing ports 56-at all times except .at the end of downstroke of piston C in case the leakage has occurred, it `is clear that the high pressure created in column G, incident to the beginning of the downstroke of piston C as necessary to open valve K, will be preventedfrom causing valve N to open.

had

The lower end of the intake pipe B may betted with a foot valve P, but not necessarily so; the valve being here shown as comprising a ball 66 arranged in a chamber 67 in the lower end wall 41 and normally resting on a seat 68 through which the intake opening 42 passes.

The operation of the pump just described is as follows: On upstroke of the piston C, a suction is induced interiorly of the latter such as to effect intake of the liquid or fluid to be pumped from intake tube B through the valve J, which body of liquid accumulates on top of the mercury column G and is confined within the piston C during the upstroke of the latter. The seal E will then act to elevate the mercury column H and the column of fluid thereon previously delivered Ato the pump barrel to effect discharge of a portion of such fluid. On up- "I stroke of the piston, the valve L moves to itsv pressure on the mercury columnv H, a portion of the mercury from the column H may be forced downwardly past the cup lleathers 51 and-added to the volume of the mercury body beneath the piston. It is apparent that if the seal between thepiston and cylinder walls was suiciently tight, the column H of mercury above the cup leathers would be maintained constant at al1 times, and there would be no passage of mercury downwardly past the cup leathers. However, this would be practically impossible to construct, as to form the cylinder or pump barrel free of small pockets can not be readily effected, and hence some slight leakage of mercury downwardly past the seal E will necessarily take place.

In the modification shown in Figures 11 to 17, inclusive, the seal E is disposed interiorly of the piston instead of exteriorly thereof and is arranged to coact between the walls of the intake tube B and the piston in effecting the pumping action; the cup leathers 51 being held in place on the tube B by rings 52 screwed on the latter.

A further modification is shown comprising a by-pass tube 90 located within the intake tube B having its end portions opening through the walls of the tube B through ports 91 and 92; the port 91 opening to the interior of the piston above the seal E and the port 92 opening to the interior of the pump barrel below the piston and beneath the seal E, and located in the by-pass 90 is a downwardly opening valve 93. The valve 93 is normally maintained closed by a spring 94, although it will ordinarily float to its seated position. This valve 93 and the by-pass tube 90 serve the purpose Aof the valve N and passages 56 in the construction shown in Figure 7.

In this construction the valve L is employed only for controlling the ports 53 in the partition M; being actuated in the manner before described. Y

However, in this arrangement the mercury columns G and H are preferably on a level with each 'other when the piston is in its lowermost position as shown in Figure 12, at which time the valve L is floated to its port closing position, and when the piston moves upwardly the level of the outer column H is lowered relatively to that of the inner column G as shown in Figure 13,' otherwise the operation is similar to that described with reference tothe construction shown in Figures 1 to l0, inclusive; upstroke of the piston effecting intake through tube B of the liquid being pumped which liquid is delivered into the casing A above the mercury column H, and downstroke of the piston effecting displacement of the liquid above the mercury column upwardly in the pump casing.

Any excess mercury as may be caused to flow from the outer column H to the inner column G past the packing E. on the upstroke of the piston will be directed back to the column H through the by-pass tube 90 on the succeeding downstroke of the piston thus maintaining a uniform level of the mercury interiorly and exteriorly of the piston.

I claim:

1. In a pump, a barrel, a piston therein, independently entrapped columns of sealing fluid in which the working surfaces of said piston and barrel are immersed, means for conveying pumped fluid from beneath said columns of sealing fluid to a point thereabove, and means for maintaining said columns at predetermined levels relative to said working surfaces, including pressure creating' means operative on one co1- umn to force sealing fluid into the other column.

2. In a pump, a barrel, an upstanding valved intake tube in said barrel, a tubular piston telescoping said tube, independently entrapped columns of sealing fluid disposed interiorly and exteriorly of said piston and immersing the working surfaces of said piston and barrel, and means for maintaining said columns at predetermined levels relative to said working surfaces, including means operative between the piston and said tube for creating pressure on and forcing fluid from the interior column to the exterior column.

3. In a pump, a barrel, a piston therein, independently entrapped columns of sealing fluid in which the working surfaces of said piston and barrel are immersed, means for conveying pumped fluid from beneath said column of sealing fluid to a point thereabove, and means for maintaining said columns at predetermined levels relative to said working surfaces, including pressure means which when leakage occurs from one column to another, operates to return said leakage.

4. In a pump, a barrel, a piston therein, independently entrapped columns of sealing fluid in which the working surfaces of said piston and barrel are immersed, means for conveying pumped fluid from beneath said columns of sealing fluid to a point thereabove, and means for maintaining said columns at predetermined levels relative to said working' surfaces, including pressure creating means operative in one.column to return leakage to the other column.

5. In a pump, a barrel, a piston therein, in-

dependently entrapped columns of sealing fluid 'in which the workingsurfaces of said piston and barrel 'are, immersed, means for conveying pumped fluid from beneath said columns of sealing fluid to a point thereabove, means for maintaining said columns at predetermined levels relative to said working surfaces, and piston actuated means operating in one column to force therefrom sealing fluid which has leaked therein from the other column.

6. In a pump, a barrel, a piston therein, columns of sealing fluid in which theworking surfaces of said piston and barrel are immersed, means for conveying pumped fluid from beneath said columns of sealing fluid to a point thereabove, and means for maintaining said columns at predetermined levels relative to said working surfaces, including a valved by-pass, also a means rendering said by-pass inoperative when said columns are at predetermined levels.

'7. In a pump, a barrel, a .piston therein, columns of sealing fluid in which the working surfaces of said piston and barrel are immersed, means for conveying pumped fluid from beneath said columns of sealing fluid to a point thereabove, and means for maintaining said columns at predetermined levels relative to said working surfaces, including a valved by-pass, also a means rendering said by-pass operative only after leakage of fluid from one column to another.

8. In a pump, a barrel, a piston therein, columns of sealing fluid in which the working surfaces of said piston and barrel are immersed, means for conveying pumped fluid from beneath said columns of sealing fluid to a point thereabove, and means for maintaining said columns at predetermined levels relative to said working surfaces, including a. valved by-pass, also a pressure creating means operative in one column to force fluid through said by-pass.

9. In a pump, a barrel, a piston therein, columns of sealing fluid in which the working surfaces of said piston and barrel are immersed, means for conveying pumped fluid from beneath said columns of sealing fluid to a point thereabove, means for maintaining said columns at predetermined levels relative to said working surative when said columns are at predetermined levels.

10. In a pump. a barrel, a piston therein, independently entrapped columns of sealing fluid in which the working surfaces of said piston and barrel are immersed, means for conveying pumped fluid from beneath said columns of sealing fluid to a point thereabove, means for maintaining said columns at predetermined levels relative to said working surfaces, including pressure creating means operative on one column to force sealing fluid into the other column, and means for rendering said pressure creating means inoperative when the columns are at predetermined levels.

ll. En a pump, a barrel, an upstanding valved intake tube in said barrel, a tubular piston telescoping said tube, columns of sealinguid disposed interiorly and exteriorly of said piston and immersing the working surfaces oi said piston and barrel, and means for maintaining said columns at predetermined levels relative to said working surfaces, including a partition between said piston and said tube and having a port therethrough, a Toy-pass between said columns, and a float valve controlling said port and said by-pass.

l2. ln a pump, a barrel, an upstanding valved intake tube in said barrel, a tubular piston telescoping said tube, columns of sealing fluid disposed interiorly and exteriorly of said piston and immerslng the working surfaces of said piston and barrel, and means for maintaining said columns at predetermined levels relative to said',

working surfaces, including a partition carried by said piston and surrounding and having a workini,r it with said tube below the level of said interior column, said partition having a port therein, and a oat valve controlling said port, said tube having a valved passage .therein below said partition, communicating the two columns with one another.

i3. In a pump, a barrel, an upstanding valved intake tube in said barrel, a tubular piston telescoping said tube, independently entrapped co1- umns of sealing fluid disposed interiorly and exteriorly of said piston' immersing the working surfaces oi said piston and barrel, a partition extending between said piston and said intake tube having ports therein, a normally open closure for said ports adapted and arranged to effect closing of said ports under the urge of accumulating sealing fluid interiorly of said piston, and means controlled by closing of said ports for transferring sealing uid from the interior columnto the exterior column.

14. In a pump, a barrel, an upstanding valved intake tube in said barrel, a tubular piston telescoping said tube, independently entrapped columns of sealing fluid extending interlorly and exteriorly of said piston, a partition extending betweensaid intake tube and said piston and carried by the latter, said partition being formed with ports leading therethrough, means for closing said ports actuated by the sealing fluid interiorly of said piston, a passage way in said piston below said partition affording a communication between the columns of sealing fluid interiorly and exteriorly oi said piston, and means actuated by the sealing uid exteriorly of said piston for closing said passage way.

l5. In a pump, a barrel, an upstanding valved intake tube in said barrel, a tubular rpiston telescoping said tube, independently entrapped columns of sealing fiuid disposed interiorly and exteriorly oi said piston and immersing the working surface of said piston, a passage way in the side wall of said piston for aiording a communication between the columns of sealing uid, means for closing said passage way interiorly of said piston, means controlled by the accumulation of sealing fluid interiorly of said piston for operating said last named means to open said passage way adapted on down stroke of the piston to impose a pressure on the interior column of sealing uid in excess of pressures in the exterior column of sealing fluid thereby causing transfer of a portion oi the sealing fluid from the inner column to the outer column.

16. In a pump, a barrel having an intake opening at its lower end. a reciprocable piston in said barrel, an intake tube projectinginto said piston from said opening, sealing fluid entrapped in said barrel, a seal separating said sealing fluid into two columns one of which extends around the exterior of the lower portion of said piston and the other of which extends interiorly of said piston and terminates below the upper end of said tube, a partition extending between said piston and tube, said partition being submerged in the sealing fluid within said piston, and being formed with ports, means controlled by the column of uid within said piston for closing and opening said ports, and a normally closed passage leading from the interior of said piston below said partition to the exterior of said piston through which sealing fluid will pass from the interior column to the exterior column on down stroke of said piston when said ports are closed.

BENJAMIN F. SCHMIDT.

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