US2031589A - Filter - Google Patents

Description

Feb. 25, 1936. R. N. BURCKHALTER ETAL 2,031,589

. FILTER Filed July'll, 1932 2 Sheets-Sheet 1 2 f7' j jf" 2 22 21 4Z R. N. BURCKHALTER ET AL FILTER Feb. 25, 1936.

Filed July 11, 19152 2 Sheets-Sheet 2 Patented Feb. 25, 1936 UNITED STATES PATENT OFFICE mma mmm Nash Bmkhauer and 'James Marshall Osburn, Michigan City, Ind., assgnors to Michlana Products .Corporatom Michigan City, Ind., a. corporation of Indiana Application July' 11, 1932, Serial No. 621,905

Claims.

-Fig. 1 is an elevation o f the complete lter' mounted on theY crank case of an engine;

Fig. 2 is a vertical section taken on the line 2 2 of Fig. 1;-

Fig. -3 is a. transverse Asection villustrating one step in the manufacture of the illter element PrOPel';

Fig. 4 is a plan viewl of a blank used in makln the filter element proper; y

But these drawings and the corresponding specic description are used for the purposej of illustration and disclosure, and are not intended to impose limitations on the claims.

The lter casing -includes a shell I0 about 54%" outside diameter drawn from 12 gauge sheet steel, the lower end of which nts in a groove Il in the top of a base casting l2 of aluminum, cast iron, or the like. This casting is substantially in the form of a cup having a. machined face |3,' at one side extended by ilanges |4'to receive bolts I5 for mounting the lter on the crank case IG,

or other place that it is to be used. 'I'here is an integral projection Il extending inwardly from the machined face and provided with a. threaded bore I8 aligned with the axis of the shell l0, to

receive the lower threaded end of the tube I9, l-" outside diameter, and f'g" inside diameter, which has-a numberof relatively large perforations 20 along the intermediate portion of its length, and is threaded at the top 2| to receive a, cap nut y22 by which the shell l0 is made fast to the base. The tube I9 is locked to the 'base casting by a. nut 45l?.

' The base is bored horizontally at 24 and vertically at 25 to form an inlet passage which is extended upwardly by tube 26 to a point above the top of the base casting, whereby substantially lthe entire interior of the base is made available as a sump, or collecting chamber 26 for foreign matter intercepted by the screen, and commonlycalled sludge. y

The base is also bored horizontally at 21 to the lower end of the bore I8 forming an outlet PaSSge.

' from the inner flanges 48 and 49, and they are (Cl. Zlib-'165) drops,'many engineers require a by-pass for all lter installations, so that the bearings may not be starved by tardy ilow of cold oil through the lter. To'meet this requirement the outlet and inlet are connected by a by-pass 28 in the `form 5 of a vertical bore in the base casting which is normally closed by a ball 29, held against a. seat 30 by a spring 3l compressed by a. nut 32.

As thus far described, the structure is well known and has been selected to illustrate an ap-l plication of the lter embodying the present invention. Y

The actual filtering of the oil is done by a barrel-shaped wire element 33 comprising 208 vertical wires per inch of circumference, each 15 about ve-thousandths of an inch in diameter and interwoven with 16 horizontal wires per inch vertically about seven-thousandths of an linch in diameter. Both Monel metal and phosphor bronze have been found satisfactory in use and, of course, other metals may be used.

In making this lter element a rectangular blank 34 (Fig. 4) is cut from a sheet and the Acorners 35 are beveled. The edges 36, 31 and 38, vare dipped rst in llux and then in molten solder,

the blank is rolled about a mandrel 39 and the edges 36 and 40 brought into overlapping relation on an aluminum strip 4I, after which they are soldered by applying heat and pressure, as by running a heavy soldering iron along the overlapping edges.

The ends of the barrel thus formed are sealed with two sheet metal heads 42 and 43, by folding the marginal portion, as best shown in Fig. 2, to grip what was formerly the edge portions 3 31, 38. The solder that has beenl picked up on these edge portions forms beads 44 and 45.`

When the screen is being assembled with the heads, the outer anges 46 and 4,1 are spaced bent to the position shown in Fig. 2 by rolling along the area indicated by 50, which has the eect of folding the sheet metal about the soldered bead and leaving the edge 5l slightly spaced from the screen so that there will be no danger of cutting.A The joint thus' formed is'V practically-'a seal against the passage of oil, orv at least against the passage of any foreign matter sought to be excluded.

'Ihe heads 42 and 43 are held in proper spaced relation by disks 52 and 53 of 12 gauge sheet steel threaded on the sleeve I9. In the process of assembly, disk 52 isfthreaded on the sleeve and locked by the nut 54.. A nut 55 is threaded Qn the lower end of the sleeve and run down against the inner portion of the head 43 andv clamped' by a nut 56.

'I'he tube I9-, and parts assembled thereon, forms a unit to be sold in commerce and assembled in suitable casings, which is accomplished in the instance shown by screwing the lower end of the sleeve into the bore I8, emplacing the shell, and screwing up the cap nut 22.

In operation the oil enters through the inlet 24 and passes into the shell, filters through the wire element 33, runs through the openings 20 Cil into the tube I9, and passes to the outlet 21, provided, of course, it is not too viscous to filter, in which case the ball 29 will rise and the fiow will be shunted directly from the linlet to the outlet.

.In the normal operation, however, with oil in the usual temperatures of service, all ow will be through the alter. The so1ia\matr wm, of course, collect against the wires forming the lter element and there will be an appreciable pressure from without, tending to collapse it. This tendency is resisted in the present instance by a grating 59 formed of 9 gauge steel wire wound in a helix with the convolutions 11g" on centers.

As the pressure on the inlet side rises the wire element will bend inwardly between the convolutions of the grating 59 andthe corrugated spring 56 and the head 43 will yieldv sufilciently to make this bending quite appreciable. Upon the pressure being relieved, however, as for instance by slowing down or stopping the motor, the wire element will resume its normal position under the reaction of the spring 56 and the inherent resiliency of the head 43, lwith the result that a great deal of the accumulatedforeign matter will be shed and settle down into the sump 26, from which it may be drawn away from time to time by removing the plug 60.

It has been found in practice that this iiexure and recovery of the screen throws, oil! about eighty (80%) percent of the accumulated sludge, hence, the emciency of the screen to pass oil is maintained over a considerable period of use determined by the foulness of the oil and the volume of the sump.

, The bending of the vertical wires about the convolutions of the grating tends to localize the strain and relieve lthe joints between the screen and the heads.

The horizontal (warp) wires 66 are practically straight while the vertical. wires-6l are bent in and out to pass between .each two adjacent horizontal wires and each vertical wire crosses and contacts with each of two verticalwires next to it. (Figs. to 9 are an attempt to show the relation on a large scale). Y v The 208 vertical wires five-thousandths of an inch in diameter. would actually present a combined width of one and forty-thousandths (1-40/ 1000") when laid parallel and in contact,`

but in the fabric described they are compacted within an inch of horizontal width, (the fortythousandths of an inch excess being absorbed .ric are indirect and irregular.

`at the intersections where they each contact is in illtering is a question that experts may answer derently and perhaps with conflict. An attempt to explain the operation in detail might result in error. The above description of and the drawings showing the best known construction for use in filtering oil used with internal combustion engines is suicient for this disclosure. Many such lters (hailing a barrel-shaped element 711g" long and 3 in diameter with the by-pass adjusted for a pressure differential of 3% lbs. to 4 lbsg) have given excellent service with four and six cylinder truckengines.

'Appropriate modications for various uses are contemplated and intended to be covered.

` We claim as our invention:-

1. In a filter of the type comprising a casing having an inlet and an outlet and a perforated tube within the casing in communication with the outlet, the combination of a barrel grating surrounding Athe tube, a barrel screen surrounding the grating and-sustained by the grating against inlet pressure, heads sealed to the tube and the end of the barrel screen and means for yieldingly resisting the shortening of the screen barrel.

2. In a filter ofthe type comprising a casing having an inlet ,and an outlet and a perforated tube within the casing in communication with the outlet, the combination of a barrel grating surrounding the tube, a barrel screen surrounding `the grating and sustained by the-grating against inlet pressure, heads sealed to the tube and the end of the barrel screen. one thereof being flexible in an axial direction, the barrel screen comprising a great many fine wires lengthwise and a small number of fine wires crosswise whereby the passages through it are long and narrow, and spring means for resisting the longitudinal contraction of the screen.

3. In a filter of the type comprising a casing having an inlet and an outlet and a perforated tube within the casing in communication with the outlet, the combination of a barrel grating surrounding the tube and having continuous cir# cumferential ribs, a barrel screen surrounding the grating and sustained by the grating against inlet pressure and heads fast on the tube adjacent to the ends of thegrating and sealed to the ends f of the screen, one thereof being yieldable and spring means resisting the shortening of the screen.

4. In a filter of the type comprising a casing having an inlet and an outlet and a perforated tube within the casing in communication with the outlet, the combination of a barrel grating surrounding the tube, a barrel screen surrounding the grating and sustained,by the grating against inlet pressure, and headswsealed to the tube and the end of the barrel screen, at least one of the heads being yieldable to tension on the screen whereby the latter may bend into the passages of the grating under the inlet pressure.

and the ends of the barrel screen, and spring means resisting the shortening of the screen.

6. IA commercial unit for filters comprising a central tube perforated along the intermediate part of its length, a pair of heads fast on the tube, one beyond each end of the`perforated part,

a barrel screen extending between the heads and sealed to them, the screen having a multitude of fine longitudinally elongated perforations, a series of circumferential ribs for sustaining the screen against external pressure, and spring means re' sisting the longitudinal contraction of the screen.V

Q7. A commercial unit for filters comprising a `Wire screen having ne Woof strands in juxtaposed relation and relatively widely spaced warp strands, and resilient means for resisting the screenformed of flexible material; means for di- -rcting the flow through the screen inwardlya series of spaced ribs forming a backing for the screen against the inlet pressure, and resilient means for resisting inward bowing of the screen between the ribs.

9. In an oil ltena casing having inlet and discharge passages, a. filter member within said casing between said passages, said member comprising a. screen element of woven wire having an unfolded substantially smooth surface and having a multiplicity of fine, indirect elongated passages therethrough, means for resiliently resisting the distortion of said member by the pressure'of oil on said surface, and a sump beneath said lter member. l

10. In an oil fllteya barrel screen of fine woven wire, resilient means to mount the screen at its

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