US3330217A

US3330217A - Pump

Info

Publication number: US3330217A
Application number: US473349A
Authority: US
Inventors: John W Baur; Walter M Jones
Original assignee: Binks Sames Corp
Current assignee: Binks Sames Corp
Priority date: 1965-07-20
Filing date: 1965-07-20
Publication date: 1967-07-11
Anticipated expiration: 1984-07-11

Description

July 11, 1967 J. w. BAUR ETAL 3,330,217

PUMP

Filed July 20, 1965 5 1 i. 7 105 92 fg 55 a! d E j five/722K; @fwam m a w /awfiggcww United States Patent 3,330,217 PUMP John W. Baur, lenview, and Walter M. J ones, Evanston,

Ill., assiguors to Biuks Manufacturing Company, Chicago, Ill., a corporation of Delaware Filed July 20, 1965, Ser. No. 473,349 2 Claims. (Cl. 103-168) The present invention relates to pumps, particularly to a pump of improved construction facilitating fabrication of pumps for corrosive and abrasive liquids, such as polyurethanes containing methyl ethyl hydroxide, and other materials of a highly corrosive and/or abrasive character.

A primary object of the invention is to provide a pump in which the piston is mounted in limited spaced relation to the cylinder walls by means of readily replaceable packings, whereby to minimize machining of the piston and cylinder and thereby to facilitate formation of the piston and the cylinder of commercially available materials highly resistant to corrosion and abrasion.

Another object of the invention is to provide an improved pump in which the piston and cylinder are unitized members without valves or ports whereby further to facilitate their formation of corrosion and abrasion resistant materials.

A further object of the invention is the provision of a pump which may readily be disassembled for repair and replacement of its constituent parts, including the piston and the cylinder.

A still further object of the invention is the provision of a pump for corrosive and/ or abrasive liquids in which the piston is formed of ceramic material and in which means are provided for maintaining the ceramic material under compression.

These other objects of the invention will become apparent from the following detailed description.

Now, in order to acquaint those skilled in the art with the manner of making and using our improved pump, we shall describe, in connection with the accompanying drawings, preferred embodiments of the pump and preferred manners of making and using the same.

In the drawings, wherein like reference numerals indicate like parts;

FIGURE 1 is a vertical sectional view of a pump made in accordance with the present invention showing the piston in its down position;

FIGURE 2 is a plan view of the pump of FIGURE 1; and

FIGURE 3 is a vertical sectional view of a second embodiment of the pump showing the piston thereof in raised or up position.

Referring now to the drawings, and particularly to FIGURE 1, our improved pump is characterized by a relatively simple piston assembly and a cylinder and valve assembly 11. The assembly 11 comprises a pair of tubular members defining the pump cylinder 14, and a pair of simplified valve structures defining an inlet valve 16 and a by-pass valve 18.

According to an important feature of the present invention, the cylinder 14 comprises a first or upper section 26, preferably formed from square bar stock, having a central bore and provided adjacent its lower end with a downwardly facing interior shoulder 28 and interior threads 30, and a second or lower section 32 having, at the upper end thereof, external threads 34 for engagement with the threads of the section 26. The upper annular edge of the section 32 supports a ring 35 having an upwardly facing annular recess of V cross-section, and a plurality of chevron packing glands or rings 36 are received in the V. The section 32 may be threaded into 3,330,217 Patented July 11, 1957 the section 26 to urge the rings 36 upwardly into abutment with a ring 40, the bottom surface of which is of V shape in cross-section conformably to receive the chevron packing. The ring 40 is in turn abutted against the shoulder 28 and thus the rings 36 are compressed as the section 32 is tightened into the section 26, the compressive force thus applied resulting in radially inward extension of the rings 36 for sealed engagement with the piston 10. Rotation of the section 32, if formed from tube stock, is facilitated by a spanner ring 42 having circumferentially spaced holes therein for reception of a spanner Wrench. It will be appreciated that the packing rings 36 may be taken up from time to time, as required, in response to wear. A combined seal and lock nut 44 is threaded on the threads 34 and engaged with the bottom of section 26 to lock the two sections in adjusted position.

The upper end of the upper section 26 is provided with a bore 58 accommodating slidable passage of the pump piston, the bore being formed with an upwardly open counterbore 60 provided with internal threads 64 for threaded reception of a plug or gland nut 66 having a central bore 68. The bottom edge of the nut 66 is formed with an annular recess of V cross-section for reception of chevron packing rings 70, the bottom-most one of which rests on a metal support ring 72 whose upper surface is of V cross-section and whose bottom surface rests on shoulder 62 defined between bore 58 and counterbore 60. The plug 66 thus forms take-up means for the sealing rings 70 to cause the same to seal about the piston 10, in much the same manner as the sealing rings 36.

The upper section 26 is further formed with a radial port 54 immediately below the upper seal 70, and a pair of

radial ports

86 and 88 immediately above and below the sealing means 36. The upper port 54 comprises the pump outlet, the same preferably being threaded for reception of an outlet fitting, and the

ports

86 and 88 together with the valve 18 comprise a bypass between the two sections of the cylinder.

The valve 18 comprises a valve block 90 suitably secured to the fiat side face of the section 26, as by screws 92. The block is provided with a pair of vertically spaced

transverse bores

94 and 96 aligned respectively with the

ports

86 and 88, and a through-bore 98 interconnecting the

bores

94 and 96. O-rings 99 positioned in counterbores at the outer ends of the

ports

86 and 88 elfect a seal between the cylinder section 26 and the valve block 18.

The vertical bore 98 in the valve block is stepped between the

bores

94 and 96 to receive and form a stop for a valve seat 100 slidably inserted in the bore and sealed relative thereto by O-rings 102 carried by the seat. Resting on the seat is a ball retainer 104 which traps a valve ball 106 in cooperative relation wtih the seat to form therewith an upwardly opening one-way valve. Pipe plugs 108 and 110 close the upper and lower ends of the bore 98, and a spring 112 is confined between the upper plug 108 and the retainer 104 to maintain the retainer and the valve seat in fixed positions in the bore.

The lower section 32 of the cylinder is provided adjacent its upper end with a plurality of radial bores 114 located as close as possible to the sealing means 3536 and communicating with the port 88-96. Preferably the upper end of section 32 is necked down and the lower end of section 26 is undercut to form an annular chamber assuring communication between the bores 114 and the port 88-96. At its lower end, the section 32 is provided with an external thread for detachable reception of the valve 16.

The valve 16 is comprised simply of a valve seat 116, a valve ball 118 and a ball retainer 120 (similar, respectively, to

elements

100, 106, 104) and an attaching collar 122 therefor. Preferably, the lower end of the section .stroke;

32 has a slight counterbore to form a shoulder or seat for the ball retainer 120, whereby to fix the assembly in the lower end of the section upon threaded attachment of the collar122. The cylinder assembly 12, or at least the lower end portions thereof, may be directly immersed in the fluid to be pumped, or a siphon hose may be connectedto the threaded bore 124 in the collar 122, whereby said bore constitutes the inlet of the pump.

The piston in the FIGURE 1 embodiment of the invention may be formed of one or more members comprising a relatively large diameter lower body portion 130 spaced from the inner periphery of the \

housing sections

26 and 32 and slidably engaging the inner periphery of the packing rings 36, and an upper stern portion 132 of smaller diameter than the body portion 130 and defining therewith an upwardly facing shoulder 134. The portion 132 of the piston extends upwardly through the bore 53 and the bore 68 in the plug 66 in limited spaced relation thereto, the same slidably engaging the inner periphery of the packing rings 70. At its upper end, above the cylinder assembly 12, the piston is provided with a screw threaded end portion 76 ment thereto of a pump operating air motor or the like.

From the position illustrated in FIGURE 1, the piston may be moved upwardly by the air motor or the other drive means therefor to cause check ball 118 .to lift from the seat 116 to permit the passage of liquid into the lower end of the chamber 14 to substantially fill the volume of the chamber below the piston body 130. As the piston moves downwardly, the check valve 118 is closed and the check valve 106 is forced open by the liquid be? ing displaced by the piston body 130, whereupon liquid flows through bores 114,

ports

88 and 96, bore 98 and

ports

94 and 86 into the upper portion of the cylinder 14 above the seals 36. The liquid so displaced fills the upper portion of the chamber 14 above the piston body part 130, and the remainder of the liquid discharged from beneath the part 130 on the downstroke of the piston is delivered through the outlet 54. On the next upstroke of the piston, the material or liquid in the chamber 14 above the piston part 130 will be delivered through the outlet because the check valve 106 is then closed and the upwardly advancing piston part 130 is decreasing the vol 'ume of the portion of the chamber 14 thereabove (note FIGURE 3). At the same tune, the piston is causing material to be drawn into the lower end of the cylinder through the inlet 124 to repeat the cycle described.

Preferably, the

piston parts

130 and 132 are so dimensioned relative to one another and the cylinder that one-half of the material drawn into the lower end of the cylinder. on each upstroke of the piston is delivered through the outlet 54 on the next downstroke of the piston and the other readily accomplished by making the stem part 132 of the piston one-half the cross-sectional area of the body part 130. A specific example is as follows:

Cylinder Cylinder section 32 Cylinder section 26 Piston part 130 Stroke 5 inches.

With the above dimensions, the displacement of the piston part 130011 its downstrokeis 11 cubic inches per and the displacement of the shoulder portion 134 of the piston (i.e., the area of part 130 minus the area of part 132 multiplied by 5) equals 5.5 cubic inches per stroke. Thus, when the piston is on its downstroke, it will discharge about 11 cubic inches of liquid from the lower part of chamber 14 into the by-pass 18. However, at the same time, the portion of chamber 14 above the piston and wrench flats 77 to facilitate .attachhalf thereof is delivered through the r outlet on the next upstroke of the piston. This is most through the outlet. Thus, only 5.5 cubic inches remain to be delivered through the outlet. Then, on the upstroke of the piston, the chamber 14 above the piston is decreased in volume by 5.5 cubic inches, and since there is no other place for the liquid to go, it will be delivered through the outlet. Because the piston is continuously operating on this 2 to 1 ratio, the result is a substantially constant fluid output from the pump.

Important features of this invention include: First, the piston is significantly smaller than the cylinder, has clearance relative to the walls of the cylinder and engages only the relatively flexible sealing rings 36 and 70. Second, fluid is transferred from one section of the. cylinder to the other via the valve 18, whereby no porting of any kind is required in the piston and the same may be solid. Third, the pump, due to the location of the

parts

114, 86 and 94 and the valve 18, is completely self-purging. Fourth, the entire pump is assembled and quickly disassembled in a most expedient manner by a few screw threaded connections. Y

The fourth feature facilitates ready replacement and adjustment of the parts subject to wear, i.e., valves 106 and 116418 and the

seals

36 and 70. To adjust seals .70, it is only necessary to adjust the gland nut 66; and

to'replace these seals, the gland nut and the old seals are removed, new seals inserted and the nut re-applied. The seals 36 are adjusted by loosening the lock nut 44, relatively adjusting the

cylinder sections

26 and 32, and retightening the nut. To replace the seals, it is only neces-. sary to separate the sections. The balls and the seats of the valves 16 and 18 are freely exposed for replacement simply by removing the plug 108 and the collar 122, re spectively. Thus, even if the pump is used with extremely abrasive and/ or corrosive materials, the four components most susceptible to wear are readily adjusted and/or re placed.

Since the cylinder 14 has no metal to metal contact with the piston 10, machining required on the two is only standard machining as opposed to precision formation of complex surfaces, ports, etc. Thus, both may economically and conveniently be made of stainless steel or any other material having extremely high resistance to corrosion and/ or abrasion, even though it may be a. very difficult material to work or machine. It is preferred to form the cylinder section 26 of square bar stock;'the necessary length being cut from the bar, necked down at its upper end to form a mounting neck, and bored, counterbored and tapped to form the various bores, ports and shoulders described. The lower section 32 may be similarly formed, or may if desired be made from commonly available stainless steel tubing of a standard diameter.

Similarly, the piston 10 has no metal to metal contact with the cylinder assembly 12, engages only the

flexible seals

36 and 70 and does not require any porting, valving or the like. Thus, the piston also may economically and conveniently be made of extremely tough corrosion and abrasion resistant material, since it requires no complex or precision machining. Specifically, the piston may and preferably is solid and may, for example, be made of stainless steel or a like material. A solid rod of stainless steel may be turned or ground to define the body and stem portions and 132 and the

connection portions

76 and 77, or the same may be made of rods of different diameters (as required) welded or otherwise secured together in coaxial relation. In either case, the rod or rods but even then the

seals

36 and 70 are readily adjustable and/or replaceable to compensate for the wear without detriment to the pump or its operation. In any unusual case, the piston may readily be replaced simply by removing the valve 16 and extracting the piston. In instances where the corrosive and/or abrasive action of the material is extremely severe, even more durable materials may be utilized to form the piston 10.

Specifically, referring to FIGURE 3, we have illustrated a second embodiment of our pump wherein the piston is formed of ceramic material loaded solely in compression, whereby even ceramic material may be utilized for high pump pressures in the order of 3,000 or more pounds per square inch. The cylinder 12 is of the same construction as illustrated in FIGURES 1 and 2, and description thereof is not repeated. The piston 10, which in essence remains of solid construction, is characterized by a relatively large, lower body section 130a comprising a first ceramic tube and a relatively small upper stern portion 132a comprising a second ceramic tube. If desired, the lower tube may be molded with an upwardly open socket guidably to receive the upper tube in coaxial relation therewith. A rod 140, preferably of stainless steel, extends through the tubes and has a flange 141 at its lower end engaging the bottom of the lower ceramic tube and a threaded upper end 142 projecting upwardly from the tubes. A nut 144 threaded onto the upper end of the rod engages the upper end of the upper ceramic tube 132a and compressively preloads both tubes between the nut and the flange 141. The result is a composite solid piston practically impervious to corrosion and abrasion.

Thus, all of the objects and the advantages of the invention have been shown herein to be attained in a convenient, economical and practical manner.

While we have shown and described what we regard to be preferred embodiments of our invention, it will be appreciated that various changes, rearrangements and modifications may be made therein without departing from the scope of the invention, as defined by the appended claims.

We claim:

1. In a reciprocating pump: a cylinder assembly consisting essentially of a first cylinder member having open ends, a second cylinder member detachably telescoped at one end thereof into one end of said first member, a first seal between said ends of said first and second members variably compressible thereby, a third cylinder member detachably telescoped at one end thereof into the opposite end of said first cylinder member, a second seal of smaller diameter than said first seal between said ends of said first and third members variably compressible thereby, an outlet in said first member adjacent said third member, and an inlet valve detachably mounted on the other end of said second member; a by-pass comprising a body detachably secured to the side wall of said first member adjacent said one end thereof and extending to opposite sides of said first seal, said first and second members and said body having intercommunicating ports therein establishing communication between immediately opposite sides of said first seal, and a one way valve in said body accommodating fluid flow from said second member to said first member; and a stepped solid piston reciprocable in said cylinder members including a relatively large diameter piston portion extending through said first seal of a smaller diameter than and reciprocable within said first and second members, and a relatively small diameter stem portion reciprocable in said first member and extending through said second seal and said third member; said seals engaging longitudinally spaced portions of said piston and slidably guiding said piston for reciprocable movement in spaced relation to the walls of said cylinder members, said second and third members being adjustably telescoped into said first member for independent external adjustment of said seals.

2. In a reciprocating pump as set forth in claim 1: said members, said body and said valves comprising corrosion resistant machinable materials; said piston consisting essentially of a relatively large diameter ceramic tube comprising said piston portion, a relatively small diameter ceramic tu'be comprising said stem portion, and a corrosion resistant tie rod extending from end to end and compressively uniting said ceramic tubes.

References Cited UNITED STATES PATENTS 28,012 4/1860 Ramsden 103168 302,003 7/ 1884 Knorp 92258 412,942 10/1889 Babcock 103216 756,993 4/ 1904 Unzicker 103168 1,133,778 3/ 1915 Wrightson 92258 1,621,142 3/1927 Vogel 103-168 1,751,350 3/1930 Moyer et a1. 92258 2,730,957 1/1956 Riede 103153 ROBERT M. WALKER, Primary Examiner.

HENRY F. RADUAZO, Examiner.