Air cleaner
United States Patent 2150745

This invention relates to improvements in apparatus for cleaning air and other gases, and more particularly to air cleaners of the liquid bath type, the invention being highly desirable for use in connection with carbureters on internal combustion engines, air compressors, air breaking systems...

Mieras, Merritt A.
Hallerberg, Theodore W.
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Other Classes:
55/329, 55/385.3, 55/DIG.21, 55/DIG.27, 181/229
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This invention relates to improvements in apparatus for cleaning air and other gases, and more particularly to air cleaners of the liquid bath type, the invention being highly desirable for use in connection with carbureters on internal combustion engines, air compressors, air breaking systems and other mechanisms wherein a supply of clean air is desirable, the invention having other uses and purposes as will be apparent to one skilled in the art.

Air cleaners, when used on carbureters must be designed to occupy a space available beneath the hood of an automobile after the engine, carbureter and other attachments have been installed. In the case of down-draft carbureters, wherein the air cleaner is usually mounted on top of an upwardly extending pipe, this space is very frequently materially limited. Accordingly, the cleaners must be designed with a minimum height, and yet perform with the desired efficiency and with no carry-over of cleansing liquid into the carbureter. The internal structure of the cleaner must therefore not only be able to effectively remove dirt from the air, but in the case of a liquid bath cleaner, must be able to remove entrained liquid from the air which leaves the cleaner.

In some instances, it is also desirable to incorporate a muffler or silencer arrangement with the air cleaner, and consequently the difficulty in designing a cleaner to occupy a relatively limited space is considerably aggravated because the muffler arrangement also requires space in addition to. the working parts of the cleaner. In addition, in the manufacture of air cleaner, a saving of material is an exceedingly important factor, because economic production is a necessity.

With the foregoing in mind, it is an object of the present invention to provide a highly efficient liquid bath air cleaner capable of occupying a very limited space.

Another object of this invention is the provision of a liquid bath air cleaner having an interior arrangement causing an activation of the liquid in a novel manner resulting in increased cleansing efficiency and permitting the cleaner to be made in a relatively reduced size.

Still another object of this invention is the provision of an air cleaner of the character set forth herein having a casing and baffle arrangement designed to provide an efficient and complete comminglement of incoming air with cleansing liquid within a very limited space.

It is also a feature of this invention to provide an air cleaner having a liquid sump and a baffle so arranged in relation to the liquid sump that incoming air will cause an activation of sump liquid somewhat in the manner of a continuous wall of liquid around the baffle as a core, resulting in an efficient deposition of dirt in the bottom of the liquid sump, where the same is readily accesible when the cleaner itself is cleansed, and where dirt once removed from the air is not again tossed in the path of air traveling through the cleaner.

This invention also provides an air cleaner structurally arranged to reduce restriction without loss of efficiency, thereby eliminating the likelihood of cleansing liquid being carried through the cleaner, preventing to a great extent loss of horsepower of the engine and increasing the fuel efficiency of the engine.

The invention further provides an air cleaner having a casing shaped to reduce restriction and also permit the relative size of the cleaner to be reduced without loss of capacity.

It is a further feature of the invention to provide an-air cleaner structurally arranged to prevent drifting or creeping of cleansing liquid along the wall adjacent the outlet and thus be carried over by outgoing air.

Another feature of the invention is the provision of an air cleaner having a free, substantially dead air space adjacent the outlet to prevent cleansing liquid from crawling or moving by capillary attraction along the outlet wall.

Another object of this invention resides in the provision of an air cleaner having an arrangement insuring a thorough comminglement of incoming air with cleansing liquid in a confined space, a subsequent centrifuging of liquid from traveling air, and a filtering of air after the centrifuging operation to insure the ultimate removal of fine particles of both entrained liquid and dirt.

It is also a feature of this invention to provide an air cleaner of compact yet highly efficient construction having associated therewith a muffler arrangement designed to silence engine noises exiting through the carbureter of an engine.

Still another object of this invention is the provision of a combined air cleaner and carbureter muffler with the entire structure so arranged as to occupy a limited space beneath the hood 'of an automobile.

While some of the more salient features, characteristics and advantages of the present invention have been above pointed out, others will become apparent from the following disclosures 56 taken in conjunction with the accompanying drawings, In which: Figure 1 Is a part sectional, part elevational view of a combined air cleaner and carbureter muffler embodying principles of the present invention, showing one-half the structure in eleva-' tion and the other half in central vertical sec-e tion; Figure 2 is a reduced plan sectional view taken substantially as indicated by the staggered section line II-II of Figure 1; Figure 3 is also a plan sectional view taken substantially as indicated by the section line I--rII of Figure 1; and Figure 4 is an enlarged fragmentary side elevational view of the centrifuging element, taken substantially as indicated by the line IV-IV of Figure 3.

Figure 5 is an enlarged fragmentary sectional view taken from the central part of Figure 1.

As shown on the drawings: As an illustrated embodiment of the present invention, there is shown an air cleaner of a hat or bonnet type for disposition on top of a vertically 23 rising intake conduit for a down-draft carbureter.

The air cleaner is circular in shape and embodies an annular inlet passage through which the air travels downwardly, then upwardly inside the cleaner, and then descends through a central outso let passage Into the intake of the carburetor.

It will be appreciated that the structure illustrated is by way of example, to properly set f9rth the invention, and that the cleaner may equally as well be used with the air intake pipe for varS5 lous mechanisms, as outlined hereinabove, and it will also be appreciated that the inlet and outlet of the cleaner may be variously located and the cleaner itself variously shaped without departing from the principles and spirit of the invention.

The cleaner preferably comprises a casing made up of two separable parts, an upper section generally indicated by numeral 5, a lower section generally indicated by numeral 6, and the lower section carries therewith a carbureter muffer or silencer arrangement generally indicated by numeral 7. Each of the casing sections and the carbureter muffler is formed of a plurality of parts and also has a plurality of other parts fixedly assoclated therewith. Hereinafter, the various parts are described as welded in their respective positions, if they are not removable, merely for the purpose of clarity and because spot welding is a simple way of connecting the parts. However, it will be distinctly understood that the parts may be secured together in any suitable manner, such as by brazing, riveting or the like.

Each of the casing sections and the parts associated therewith are preferably di-formed or stamped, this being an economical manufacturing method.

With reference to the illustrated apparatus as a whole, it will be noted that the muffler part 1 projects outwardly beyond the cleaner part, as 6 seen in Figure 1. This arrangement permits the disposition of the combined cleaner and muffler beneath a sloping portion of the hood of an automobile where the apparatus would not fit if it were all of the diameter of the mufer part 7. The lower casing section I includes, preferably in one piece, an outer wall 8, a bottom wall 9 and an inner wall 10. This Inner wall I is stepped to provide a shoulder against which an outlet conduit II abuts, the conduit being spot welded to Ti the inner wall above the shoulder. With this construction, it will be seen that the lower casing section provides an annular liquid sump for a cleansing liquid 12, such as used crankcase oil, for example. .The bottom wall 9 preferably slopes downwardly and outwardly so that the sump is S deeper adjacent the outer wall 8. The upper margin of the outer wall is preferably turned inwardly, as indicated at 13 a distance beyond any other portion of the wall to prevent cleansing liquid from splashing out of the cleaner in the event it is violently agitated by a jarring or bumping of the apparatus to which the cleaner is attached.

The upper casing section 5 includes an outer wall 14 preferably integral with a dome-shaped top 15 centrally dished as indicated at 18.

The two casing sections are held together in operative position by means of a bolt 17 threadedly engaged in a bushing 18 spot welded or otherwise secured to a yoke formed of two light and s0 complemental parts 19 each having a bulged central portion to fit the bushing and turned end portion 20 spot welded to the wall 10 of the lower section I. The bolt extends upwardly through the dished portion of the upper section where it is gg engaged by a thumb nut or the equivalent 21. If so desired, the thumb nut may be made a substantially integral part of the bolt and connection established with the bushing 18 in a known manner. 0g In the present instance, the interior parts of the air cleaner are preferably carried by the upper section. An upwardly curved annular member 22 defines the cleaner outlet, this member having a plurality of relatively narrow and widely g spaced legs 23 spot welded to the top 15 of the casing section. The lower portion of this member is shaped, as at 24, to hold a gasket 25 against which the upper edge of the conduit II abuts when the casing sections are joined. The upper 10 edge of the conduit II is preferably turned inwardly to provide a tighter engagement with the gasket.

Spot welded to the inner face of the annular member 22 Is a vertically extending conduit 21 for telescopic association with the conduit II, this conduit 26 having an outwardly flared upper end 27 shaped to provide an annular open space 27a which will be substantially a dead air space and prevent sump liquid 12 from crawling, creeping, g0 rising by capillary attraction or otherwise moving along the undersurface of the part 21 and thus be carried over by outgoing air into the carbureter or other mechanism.

Near the lower end thereof, the conduit 26 is g5 provided with a plurality of spaced tongues or lugs 28 struck therefrom. These tongues support a split spring ring 29 thereupon, which split ring is of the usual construction of a split ring, tends to contract, and may be opened for removal. The 0o split ring supports a baffle 30, seen clearly in Figures 1 and 2, and the arrangement of which Is very important to the efficient operation of this invention.

The baffle 30 is annular and extends to a point u adjacent the casing wall 8, leaving an annular opening 31 between the outer edge of the bame and the wall. The baffle is somewhat concavoconvex in shape with the concave side uppermost, but the outer part of the baffle is nearly straight T0 and extends substantially obliquely, in keeping with the oblique bottom wall 9. It is preferable to have the baffle substantially submerged, that is, with the initial sump liquid level above the bame, but for use on an automotive vehicle, it is deemed ty preferable to have the inner edge of the baffle project above the initial liquid level to lessen the likelihood of back splashing over the inner baffle edge due to road roughness, etc. If the cleaner is used on a stationary mechanism, the danger of back splashing is not present and the baffle may be submerged.

The baffle also includes a plurality of upwardly extending legs 32 which are preferably relatively narrow to leave wide open spaces 33 therebetween.'-The legs terminate at their upper ends in an integral flange 34. At the inner side thereof, this flange is formed into the shape of a channel 35 opening outwardly.

A filter element in the form of one or more layers of screen 36 is disposed above the baffle in spaced relationship thereto to provide a free air passage therebetween. This screen filter slopes downwardly and outwardly away from the outlet opening of the cleaner and has the outer end supported by an inwardly turned margin 37 on the wall 14 of the upper casing section, and the inner end of the screen filter is engaged in the aforesaid channel 35 integral with the baffle. Immediately above the screen filter 36 and resting thereupon is a centrifuging element generally indicated by the numeral 38. The centrifuging element is best seen in Figures 1, 3 and 4, and includes an outer wall 39 lying against the inner 80 face of the wall 14 of the upper casing section.

Both these walls 39 and 14 are shouldered, as indicated at 40, so that the wall 14 effectively supports the centrifuging element in proper position.

At this point, it should be noted that the wall 14 is preferably a divided wall in two separate parts, the line of division occurring at 41, and the lower part being removable from the upper part, the edges of the two parts abutting. The wall 39 of the centrifuging element is preferably spot welded to the lower part of the wall 14 so that the. lower part of the wall 14, the centrifuging element, the screen filter 36, and the baffle 30 may all be removed upon the removal of the spring ring 29.

The centrifuging element includes an inner annular flange part 42 also seated in the aforesaid groove 35 integral with the baffle. The body portion 43 (Figure 3) of this element slopes downwardly and outwardly away from the cleaner outlet in accordance with the slope of the screen filter 36. At the outer end thereof, the sloping portion merges in a curve with the outer wall 39.

From this sloping portion, a plurality of blades 44 are struck upwardly so that the upper edges of the blades are substantially in the same plane with the flange part 42.

A filter element 45 is supported by the fan blades, this element being preferably a circular mass of curled cattle tail hair, although other substances might be utilized. Above the filter means 45 is a multiple layer of screen 46, preferably a double layer, and the screen is preferably of such mesh as to prevent ignition of the filter 5 mass in the event an internal combustion engine backfires through the carbureter and cleaner.

The screen 46 underlies the flare 27 of the conduit 26 and is thus held in position, it in turn maintaining the filter mass in position at the top of the cleaner.

As pointed out hereinabove, the releasement of the nut 21 or the removal of the bolt 17, as the case may be, permits the upper cleaner section to be withdrawn from the lower section, thereby 76 affording access to the spring ring 29, which ma" be removed, and thereby releases for removal the contents of the upper casing section.

In use, air may enter the casing through the annular passage defined by the outer wall 8 of the lower section and the outer wall 14 of the upper section, this inlet passageway being protected from falling dirt and debris by means of an annular hood 47, if so desired. The hood Is, of course, preferably spot welded to the upper casing section and shaped to perform its duties as well as enhance the general appearance of the cleaner.

It will be especially noted that the upper casing section 14 is of less diameter above a region 14a than therebelow. In other words, the casing section is stepped in at the curve 14a to lessen restriction at the inlet and likewise materially reduce the chance of liquid carry-over through the outlet. In addition, such shaping of the parts to increase the size of the inlet permits the cleaner as a whole to be of less diameter than if the wall 14, in this instance, were of the same diameter throughout, with no lessening of capacity.

Material may thus be saved, materially adding to manufacturing economy. In this instance, the carbureter muffler arrangement 7 is attached to the lower casing section. The muffler may be formed in two parts, an upper part 48 and a lower part 49, interlocked together by an annular bead 50. The upper wall of the part 48 slopes in accordance with the bottom wall 9 of the cleaner, and adjacent its inner margin it is offset, as indicated at 51, to support an annular gasket 52 and hold the same in abutment with the lower wall of the cleaner to prevent leakage of both noise and air between these parts.

After the offset the upper wall of the part 48 extends vertically in a cylindrical portion 53 which is spot welded to the wall 10, preferably inside the yoke 19. An outlet conduit 54 having a flared end 55 spot welded to the offset portion 51 is in direct communication with the aforesaid conduit II to further define the outlet passage from the cleaner.

The wall of the lower part 49 of the muffler terminates in a downwardly turned margin 56 to 45 support a gasket 57 effecting a seal between this wall and a short conduit 58 spot welded to the wall and arranged for a clamping attachment around the intake pipe of a carbureter. The intake pipe of the carbureter will abut the gasket 50 57 to further. enhance the seal. Another conduit 59 is welded to the upper face of the bottom wall and is telescopically associated with the conduit 54 but spaced therefrom to provide an opening therebetween leading directely into the hollow 55 interior of the muffler 7.

The present invention, which may be made very compact, is highly efficient in action. Incoming air descends in the annular passage between the walls 8 and 14 and contacts the sump 60 liquid above the baffle. The initial rush of air, assuming that an internal combustion engine equipped with a cleaner is started, will sweep the sump liquid away from the upper surface of the baffle, the air thoroughly commingling with the liquid. Much of the heavier dirt particles retained by the air will be removed by contact with the sump liquid and washed over the inner edge of the baffle by the action of the air. The air 70 turns, as indicated by the long arrows in Figure 1, upwardly, passing through the screen 36 which removes further dirt from the air and tends to cause an initial separation of liquid from the air. The air is then centrifuged by the element 38 so as to be urged toward the outer wall of the casing and thus made to follow a longer path to the outlet. The centrifuging action further removes some of the entrained sump liquid from the air, and any remaining particles of dirt or entrained liquid will be removed from the air by the filter mass 48. Upon passing through the filter mass, the air turns inside the top of the cleaner and descends through the outlet passage to the carbureter. The flare 27 on the conduit 26 and dead air space 2Ta tends to keep the air in the central or outer part of the filter mass and prevents sump liquid from creeping up the wall 26. During the cleaning process, sump liquid removed from the air by the filter 45 will drip back into the air path through the screen 38 and tend to maintain this screen filter clean. The sump liquid, with the present construction will follow the course indicated by the heavy arrows, that is, a goodly portion of sump liquid, that which is not carried up into the filter mass by the traveling air. In this instance, the liquid will rise through the annular space 31, due to the fact that it seeks its own level and also by the aspirating action of incoming air, is washed over the baffle and descends over the Inner edge of the baffle, carrying the heavier dirt particles therewith back into the sump. These dirt particles will follow the slope of the bottom wall 9 and tend to accumulate in an annular mass, as indicated at 81, adjacent the lowermost and outermost part of the cleaner.

Too much liquid will not be educed through the space 31, however, because this space is disposed Ua radially outward adjacent the casing wall, while the imperforate part of the baffle underlies the region of higher air velocity, namely, adjacent the turned margin 37 of the wall 14.

Such disposition of the dirt removed from the air prevents this dirt from being carried back into the cleaner and again removed by incoming air.

The dirt, being heavier than the air or sump liquid, will remain substantially in the position indicated at 61 and will not be agitated sufficiently to be carried up into the cleaner by the flow of oil around the bafle. The finer dirt particles removed by the screen 36 and the filter 45 will be washed downwardly towards the baffle by returning liquid removed from the traveling air and thus reach a position where they will be washed over the inner edge of the baffle in the manner above described.

The particular disposition of the baffle and the substantial submersion of all or the major part thereof below the initial liquid level greatly aids in providing the foregoing action and the circulation of sump liquid around the baffle, as indicated by the small heavy arrows. Such action results in a high cleansing efficiency, and as a result, the cleaner may be made in a smaller size than would be the case if the baffle were permitted to project materially above the initial liquid level, and yet have adequate efficiency and no carry-over of liquid into the carbureter.

At the same time that air is sucked through the cleaner by the action of the internal combustion engine, noises developed in the engine manifold and similar locations will exit through the carbureter in the form of sound waves which will pass through the passageway II into the interior io of the muffler 7 and be neutralized In a known manner.

It will be noted that, if the muler is not deemed necessary or desirable, a conduit, such as 60, may be attached directly to the cleaner in lieu of the portion 53 of the upper wall of the muffer.

From the foregoing, it is apparent that we have provided an air cleaner capable of functioning with adquate efficiency, with no carry-over of entrained liquid into the carbureter or other apparatus with which the cleaner may be used, and which may be made in a relatively small size to occupy a very limited space. It is also apparent that we have provided a combined form of air cleaner and carbureter muffler with the proportion of parts so sized as to fit within a limited area and beneath a sloping portion of an automobile hood, if such disposition is desired. Further, the entire device is simple in construction, easy and economical to manufacture and assemble, requires little or no attention during operation, with the exception of removing the dirt and supplying additional sump liquid at periodic intervals, and is extremely durable.

We are aware that many changes may be made 33 and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and we, therefore, do not purpose limiting the patent granted hereon otherwise than is necessitated by the prior art.

We claim as our invention: 1. In an air cleaner, a casing having an inlet and means defining a central outlet opening through the bottom of the casing, said casing having a liquid sump therein around the outlet, a filter element around the outlet above the sump, and an arcuate member around the inner end of the outlet having a concave lower face defining a space above said filter element. A 2. In an air cleaner, a casing having an inlet and a centrally disposed outlet defined by conduit means, said casing having a sump for cleansing liquid, and outwardly flaring means associated with the inner end of said conduit means, said as means presenting a hollow part towards the path of incoming air and providing substantially a dead air space adjacent the outlet.