Pump

Sept. 15, 1953

J. J. LYTH

PUMP

2,651,997

Piled May 29, 1950

Sheets-Sheet 1

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/rwentor

Jahn J. Lyth /Mf&amp;vtey

Sept. 15, 1953

J. J. LYTH

PUMP

2,651,997

Filed May 29, 1950

Sheets-Sheet 2

<img file="US2651997A_D0002.tif" />

Fig. 3 /nvendor

John J. Lyth

Patented Sept. 15, 1953

2,651,997

UNITED STATES PATENT OFFICE

2,651,997 PUMP

John J. Lyth, Valleyfield, Quebec, Canada

Application May 29,1950, Serial No. 165,051 (Cl. 103—44) features and combinations of features herein disclosed, together with all such modifications thereof and substitutions of equivalents therefor as are within the scope of the appended claims.

⁵ In the accompanying drawings which illustrate embodiments of the invention now preferred but to the details of which the invention is not limited:

Fig. 1 is a view of the pump, half in side eleva¹⁰ tion and half in section on the line I—I of Fig. 2.

Fig. 2 is a view of the pump, half in end elevation and half in section on the line 2—2 of Fig. 1..

Fig. 3 is a view similar to Fig. 1 illustrating a. modification.

¹⁵ Referring more particularly to the drawings,, i I designates a preferably cylindrical or tubular body member, the length of which is preferably materially less than the diameter thereof, having: at least one hollow neck 12 communicating with:

the interior thereof, and a hollow foot 13, the: interior of which is completely isolated from the: interior of the body. In Fig. 1 the body is shown provided with a single neck 12 leading from the: highest point of the body and in Fig. 3 it is shown:

²⁵ as having an additional neck I2^a leading from, the lowest point of the body. The neck 12 preferably extends vertically upward from the body and, for compactness, the neck I2^a may extend laterally with downward inclination, whereby 30 the distance between the top of the neck 12 and the bottom of the foot 13 may be the same in both forms and permit of interchangeability without altering the elevation of a pipe connected to the neck 12. The interior of the body consti35 tutes an impelled liquid chamber 14. When the liquid to be handled is free from suspended solids which might accumulate in the body, the neck 12 alone may suffice for both ingress and egress of liquid and is located at the uppermost point 40 of the body to permit escape of air or vapour which, if it could accumulate, would seriously interfere with efficient pumping operation, as will be readily understood. For dealing with suspensions from which solid matter might settle in the body, the necks 12 and I2^a provide for separate egress and ingress, respectively, of the suspension, the ingress preferably being at the bottom, as shown, so that incoming suspension will pick up and carry with it any solids tending to 50 settle out; and the egress being preferably at the top, for the reason already given. Obviously, the. direction of flow may be reversed if desired.

It will be noted that, except where the neck; or necks and the foot attach, the wall of the body 55 is of uniform rectangular cross-section which,, combined with the cylindrical form, produces a mass in which little or no undesirable internal, stress will be produced on cooling from a high;

Claims.

This invention relates to pumps and especially to pumps for handling liquids or suspensions which cannot be pumped satisfactorily, or at all, by ordinary pumps because of corrosive or abrasive or clogging effect of the liquid or suspension on the working parts of ordinary pumps, or because the liquid or suspension would be contaminated by the material of ordinary pumps.

Pumps of the above type customarily comprise separate passages for an impelling liquid and for an impelled liquid or suspension, separated by a member movable by the impelling liquid to move the impelled liquid, such member being usually a flexible diaphragm. Pumps of this type heretofore used have a number of practical disadvantages, such as complicated and expensive construction, difficulty in renewing diaphragms, the form and arrangement of the diaphragms, and unbalanced or otherwise faulty transmission of power from the impelling liquid to the impelled liquid.

The primary object of the present invention is to provide a pump of the aforesaid type which is simple and inexpensive in construction; in which the impelled liquid passages are readily accessible for cleaning and the diaphragms for cleaning and renewal without disturbing any of the connections of the pump. A concomitant object is to provide a diaphragm pump in which the diaphragms and the movement of impelled liquid in the pump may be under constant observation. A further object is to provide a pump so constructed that the body thereof may be formed of glass or ceramic material. A still further object is to provide a double diaphragm pump in which the pressure of impelling liquid is applied to the best advantage and equally to both diaphragms. Another object is to provide a diaphragm which will be exceptionally durable. Various other objects and the advantages of the invention may be ascertained from the following description and the accompanying drawings.

Broadly speaking, the invention consists in a pump comprising a chamber for an impelled liquid and chambers for an impelling liquid arranged on opposite sides of the impelled liquid chamber and separated therefrom by circular, circularly corrugated diaphragms, and a plunger pump associated with said impelling liquid chambers in suchwise as to deliver exactly equal flows of liquid to the two chambers, the diaphragms being readily removable for cleaning and replacement; the form of said chambers being such as to permit of making them of glass, ceramic or moulded plastic, and also being such as to prevent the accumulation of air, vapour or solids in the impelled liquid chamber.

In greater detail, the invention consists in the

2,661,997 temperature, such as that incident to a molten or fused state of the material or to the firing of ceramics.

The body may be composed of any material suitable for the service to be required of the pump. The material may be metal, vulcanite, plastic, glass or. a ceramic'and it is a feature of. the invention that the form of the body and its neck or necks and foot is such as to avoid the creation of internal stresses which would adversely affect the strength of the body if moulded of glass or a, ceramic. A plastic suitable for use in making' the body, known under the trade.name.'TiUCite,’’· has adequate mechanical strength,and .rigidity, is,, inert to most acids and alkalis and has the added advantage of being transparent. If transparent; plastic or transparent glass is used as the body material,, the, conditions-within -the .body may be kept under constant observation during operation of the pump.

If desired, the inner surface of the body and its necks 12. and 12^a may -be provided with-ajining 5, of material. adapted to resist corrosion by.. the impelled, liquid, or to protect the liquid, against contamination by the material of the body; The. nature of-the lining.material will depend on the nature of the liquid,- to_; be/handled .by. the_: pump.. Materials, such- as lead,, aluminum, silver, vulcanite, vitreous,,enamel,, wax, plastic or- even glass, may be used, the ^election depending, on the natures of the impelled liquid and of the body, material. The.,lining, contemplated is· in one. piece covering the entire interior, of the body and neck or necks,and extending, a, suitable distance over· the, end surfaces of the body and;neck or, necks, as indicated;at. (6, so, as to protect these surfaces against corrosion by.-liquid_?entering'between them; and elements, abutting, them.

The interior 17 of the foot 13 tapers upwardly, and communicates at its.upper.end .with two equal and.oppositely extending, passages 18.leading, to the ends of the body. The, combined cross-sectional areas of . the two passages, l8..-are_:suhstaii₇. tially equal to the maximum.cross-sectional ,areaof the foot interior 17.,

Pished or cup-shaped. concave end caps 19, each of a depth equal,;to substantially, half the . length of the body, are provided for the body and have flanges; 20; extending radially beyond the body and, formed- with· apertures 21 beyond the ₅₀circumference of the.body.· Attaching bolts 22 extend from cap, to, cap and through the flange apertures 21 and are provided with nuts 23 bear-.' ing against the outer, .or remote, surfaces of the-cap. flanges 20, whereby the body may be tightly ₅₅clamped between the caps? If the ,spacing of thebolts 22. so requires,, the body may be,formed with passages .24 adjacent-the.neck 12, and foot . 13, ' through which certain. of. the· bolts. may. pass. The caps 19 are provided with ppr.ts.25.registering. ₆₀with the body , passages- 18 and communicating. the interiors 26 of both caps with the foot pas-, sage 17, these interiors. 26 being, impelled liquid, chambers. The end-caps may be formed of any suitable material, such as.metal,, vulcanite, plas-nR tic or glass.

A. substantially circular,, flexible, and. elastic . diaphragm 27 is provided at each end of the body 11, the peripheral . portion of each diaphragm ^ extending, between the end of the ..body- and the adjacent surface of the closure cap 19 therefor. These, diaphragms are formed with circular cor- , rugations concentric . with, -one another (indwith the diaphragm. The diaphragm; separates theImpelled liquid chamber !4 of the body from. the..

impelling liquid chambers 26 of the caps. The peripheral portions of the diaphragms act as gaskets between the caps 19 and the ends of the body I ί to ensure liquid tight joints. To facilitate making of such joints between the caps and body around the passages. 18, the diaphragms preferably-have· radially extending portions 28 formed with openings 29' in register with the passages 18 and ports 25. The diaphragms may 10 be formed of any suitable flexible and elastic material which is inert and impervious with respect to the impelled liquid in chamber 14 and the impelling liquid-in chambers 26. Physically suitable materials: are nubber and certain of the plastics now readily available on the market. One such plastic is that known under the trade name

Tygon” and has the additional advantage of being transpar ent.

Each- impelling- fluid chamber 2 6 is provided at its; highest,- point· with. an air- vent_: cock, 3 0 and one of these, may, have a? funnel shaped outlet 31 to-facilitate.filling: the- chambers 26.with the impelling fluid;

The structure heretofore;· described is mounted by means of. its foot 13 on a closed reservoir 32 for impelling, liquid, the interior 17, of the foot communicating-with; the interior, of. the reservoir at the top thereof, One end: of; the reservoir is closed by a plate, 33; having; a tubular extension 34-projecting· into., the.-reservoir. and provided.in its inner, portion with a-replaceable., bushing 35 of antifriction material, such.as brass or bronze, and in-its .outer portion with a .packing gland 36,’ also of antifriction material.. Packing 37 is com35 Pressed between the bushing and gland to make hquid.tight: contact with a plunger 38 adapted to be,reciprocated .in. the bushing and gland by any suitable mechanism.

When .installed,- the, pump is .associated, with a 40 conduit for impelled, liquid communicating with the chamber 14. through-the neck 12, or necks 12 and 12», and having · check valves, one on each side of the pump, to control the direction of liquid flow.·. With, the. plunger 38 at midstroke the 45 reservoir 32, chambers, 26 and; connecting passages are completely filled with an impelling liquid, such as water, both vent cocks 30being open and the liquid being,introduced through the funneE3i.- As.the neck, passage . 17 leads from the । highest point of. the.-, reservoir,. entering water displaees-air-m the reservoir and in the chambers 26. so. that-none remains in the.system to inter^^Y^pum^pin_a action. ^{When the} system is .filled, · bo uh cocks 3 S are closed,, and . the water becomes a hydraulic-transmission between the plunger 38.and the diaphragms?

In operation, when the plunger moves inwardly of the reservoir- it forces liquid from the reservoir through the foot.-. passage 17, body· passages 18 and cap ports 25 into the chambers 26, thereby displacing liquid therein to -force the diaphragms toward .one another; and-. into the . chamber 14 thus displacing liquid from the chamber 14 into the.conduit to which: it is connected. When the plunge? moves outwardly of the reservoir, it draws ^ba?4.v.^he fluid from..the chambers 26 and thereby moves· the diaphragms away from nZd^nOtl^^r ™_^{draw im}P^elled &gt; liquid into the chamber !4.1 The.-checfcvalves associated with the pump ensures unidirectional liquid flow in the. conduit.

- The . volumetric displacement of the plunger determines./the amount of . flexion of -the diaphragms and by varying the stroke or the diameter, or both . stroke, and diameter,· of . the .75

2,661,997 s

plunger, the displacement of the diaphragms may be varied from nothing to a maximum at which the diaphragms are, in their central portions, substantially flattened against one another or against the caps according to the direction of plunger movement. The number and depth of the corrugations are such that at maximum displacement of the diaphragms the corrugations merely tend to be straightened out by flexion and the diaphragms are not subjected to destructive radial tension. The cross-sectional areas of the two passages 18 being equal, and together equalling the cross-sectional area of the foot passage 17, ensures that the flows of impelling liquid to and from the two chambers 28 are always equal, thus ensuring equal displacements of the diaphragms, while the depth of the caps being substantially half the length of the body ensures that the maximum inward and outward displacements of the diaphragms are equal and that the diaphragms cannot be excessively displaced in either direction.

The removal of nuts 23 at either end of the pump releases both caps 19, which may be removed without displacing any of the connections 25 of the pump and will enable easy removal of both diaphragms for cleaning or renewal and also will afford unobstructed access to the chamber 14. This feature is especially important if the pump is used for foodstuffs and must be cleaned at 3 frequent intervals of time.

The removable sleeve 34 permits of very quickly altering the capacity of the pump by substituting a sleeve carrying a plunger of different diameter, complete with packing already in place. 35 Also, in event of leaky packing, a replacement assembly of sleeve, packing and plunger can be inserted more quickly than packing alone can be replaced.

As previously pointed out, the body and caps, 40 or either body or caps, can be made of transparent material, such as glass or plastic, and the diaphragms of transparent plastic, so that the flow of both impelling and impelled liquids and the physical condition of the diaphragms may be 45 under constant observation. This is of importance in cases where the impelled liquid would be detrimentally affected by leaking of impelling liquid thereinto.