Oil filter

Aug. 31, 1943.

H. G. EISLER

OIL FILTER

Filed Dec, 5, 1938

2,328,131

Sheets-Sheet 1

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INVENTOR.

Tfe/try G. EZster

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ATTORNEYS.

Aug. 31, 1943.

H. G. EISLER

OIL FILTER

2,328,131

Filed Dec. 5, 1938

Sheets-Sheet 2

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INVENTOR.

BY

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ATTORNEYS. J,,

Patented Aug. 31, 1943

2,328,131

UNITED STATES PATENT OFFICE

2,328,131

OILFILTER

Henry G. Elsler, Wilmette, Hl.

Application December 5, 1938, Serial No. 243,937

Claims. (Cl. 177—311)

The present invention relates in general to oil filters, and more in particular to oil filters for use in connection with internal combustion engines, especially the engines or motors of trucks and automobiles. The object of the Invention, generally stated, is to provide an improved and efficient device of this character.

A special object of the invention is to reduce the cost of manufacture of the filter to a minimum, which is accomplished by a special arrangement of parts which eliminates the housing usually provided for the filter can or cartridge.

A further object is the provision of an arrangement which will give a warning to the driver in the event that the filter cartridge should become plugged with sediment to such an extent as to impede the proper flow of oil.

A further object is to provide a new and improved filter cartridge which is highly efficient in purifying the oil and which is especially designed to cooperate in the operation of the warning device above referred to.

Other features and the advantages of the invention will be pointed out in the course of the following description, in which reference is made to the accompanying drawings.

In the drawings,

Fig. 1 is a vertical section through the complete filter, except for a portion of the filter cartridge which is not shown in section;

Fig. 2 is an elevation of the complete filter and support, showing also the circuit arrangement for the warning signal;

Fig. 3 is a top view of the filter cartridge, with a part of the upper end closure broken away; and

Figs. 4, 5, and 6 show details of the construction of the filtering element in the filter cartridge.

Referring to the drawings, the filter can or cartridge comprises a cylindrical metal wall 25, a lower perforated end member or bottom 26, a top member 33 of peculiar configuration, and a false top or spacer member 32, together with the filtering material which is packed in the cartridge. The main filtering element is a compact roll of filtering material formed in a novel maimer which will first be described.

The construction of the above mentioned roll can be readily understood from Figs. 4, 5, and 6. The reference character 50 indicates a sheet of laminated crepe paper, which is about eight and one-half inches wide and several feet long. A suitable material may be purchased on the market under the trade name of Kimpak,” and comprises about twenty leaves of crepe paper rather loosely adhering together. In forming the roll, the sheet 50 is laid out flat and a strip of corrugated pressed fiber board 51 is placed on top ₅ thereof, with the lower edge of the strip of fiber board in alignment with the lower edge of the sheet, as at 53. The sheet 50 is then folded over at 54, covering the strip 5i. A second strip 52 of corrugated fiber board is next laid down on IO the folded-over portion of sheet 50 and the remainder of the sheet is folded at 85 back over the strip 52. In order to retain the parts temporarily, a loose stitching may be employed, as indicated at 56.

The folded sheet 50 with the inserts 5t and 52 is next wound on a mandrel to form a roll, and after the end is suitably secured, the complete roll is removed from the mandrel and is ready for assembly in the cartridge.

2Q In filling the cartridge, the inside and the bottom may first be painted with glue or shellac. A layer 27 of coarse fibrous filter material is then placed in the bottom of the can, after which the rolled up sheet 50 may· be inserted, as shown in 2_δ Fig. 1. The center of the roll is then tightly packed with cotton waste, which expands the roll slightly so that it fits close within the wall 25 of. the cartridge, to which it adheres. Several discs 29 of felt are now placed on top of the roll, 30 followed by a layer 30 of ground bone, and several more discs of felt 31. The spacer disc 32 is then inserted, after which the top member 33 may be secured in place by means of a machine which rolls the edge of the top member and the 35 upper edge of the can together in known manner.

The top member 33 has a central raised portion 34, in the center of which there is a single opening 11 for the exit of oil. The top may be stiffened by ribs 35, seen in Figs. 1 and 3. The ₄q spacer 32 is provided so that the oil, after passing through the filtering material, will have free access to the opening 11, which would not be the case if the filtering material extended into contact with top member 33. A disc of metal gauze 45 could be used in place of the perforated disc 32.

The filter cartridge is clamped between two concave steel stampings 2 and 15, no housing in the usual sense being provided. The whole is supported on a rectangular frame which may be 50 seen clearly in Fig. 2. This frame comprises ends 42 and 43 of U-shaped cross-section, and sides 40 and 41, which may be welded to the end pieces. This frame may be supported on or adjacent the motor in any suitable manner.

The lower concave stamping 15 rests on the

2,828,131 end piece 43 of the frame, being provided with a transverse channel 20 to receive it. This stamping also has formed therein a small extension having a vertical wall 16 which is drilled to receive the coupling member 17. This coupling member is secured to the stamping by means of a nut 19 and provides for connecting the inlet pipe 18. The pipe 18 comes from the oil pressure line of the motor.

The stamping 15 is formed with an annular ledge 22, on which the bottom of the filter car-, tridge rests, a gasket 21 being interposed to prevent leakage of oil. The space between the bottom of the can and the bottom of the concave stamping 15 forms a sump for the accumulation of coarse sediment and impurities. . Oil entering the sump from the inlet pipe has access to the filter through the perforations in the bottom of the cartridge.

The upper concave stamping 2 is similar to the lower stamping 15, and has an annular ledge 5 which rests on the upper rim of the cartridge, a gasket 10 being provided at this point also to prevent leakage of oil. As in the case of the lower stamping 15, the upper stamping 2 has an extension formed with a vertical wall 3 to which the coupling 12 is secured by means of the nut 14. The outlet pipe 13 extends to the crank case of the motor.

As previously noted, the filter cartridge is clamped between the two stampings 2 and 15. To accomplish this, the upper end piece 42 has a threaded opening in which the bolt 44 is located. At the end of the bolt there is a member 46 which lies in the depression 4 in the upper stamping 2. When the bolt 44 is screwed down, the member 46 presses the upper stamping firmly down against the filter cartridge. The lock nut 45 is provided to prevent the bolt 44 from shaking loose.

The arrangement for actuating the warning signal includes a bronze spring member 8 which is screwed to the upper stamping 2 by means of a heavy machine screw 6, a nut threaded onto the machine screw, and a pair of insulating washers, as shown in Fig. 1. An additional binding post nut 7 is provided for attachment of a conductor. The spring member 8 is tensioned downward and has a flat portion at the end which is normally in engagement with the top of the cartridge and partially closes the opening i i, there being a small opening 9 in the spring which is in register with opening fl. The cartridge is grounded to the frame by means of the spring 36, which is held under the nut 14 and presses against the top of the cartridge. Fig. 2 shows the circuit arrangement. Conductor 47 extends to the ignition apparatus, and S is the usual ignition switch which connects the ignition circuit with the battery B. One end of conductor 48 is connected under the binding post 7, while the other end connects to the signal lamp L, located on the instrument panel. The other side of the lamp is connected to the ignition circuit, as shown.'

The operation of the complete filter will now be described. In Figs. 1 and 2 the equipment is shown in normal condition, that is, in its condition when the motor is not running. When the ignition switch is closed, the ignition circuit is completed in the usual manner, and at the same time a circuit is completed for the lamp L, said circuit including the grounded battery b’ the switch S, lamp L, conductor 48, spring 8, the cartridge, and the spring 36 to ground. The lamp I, lights up, therefore, as soon as the ignition is turned on.

When the motor is started up, the oil pump develops pressure in the lubricating system, and 5 oil will flow through the inlet pipe 18 into the sump beneath the filter cartridge. As soon as the sump becomes filled, pressure is developed which forces oil into the filter cartridge through the perforated bottom 26. Passing through the filtering material in a manner which will be explained more in detail later, the oil soon fills the space beneath the top 33 and begins to flow out through the opening JI and the small opening 9 in the spring 8. Due to the small size of 15 opening 9, however, pressure immediately builds up which forces the spring 8 upward and breaks the circuit of lamp L. The lamp is accordingly extinguished, which advises the operator that oil is flowing through the filter. The oil that 20 passes the filter accumulates in the space above the filter cartridge until it reaches the level of the. outlet pipe 12, when it begins to drain back into the crank case. Outlet pipe 13 should have ample capacity so as to take care of, all the oil 25 that can come through.

Describing the filtering action more in detail, the coarser particles of dirt, metal, carbon, etc., are deposited in the sump due to the decrease in the velocity of the oil after emerging from the 30 inlet pipe 18. Other coarse particles, including some of the lighter carbon particles, are intercepted by the layer of fibrous filtering material 27. The principal filtering action, however, takes place in the roll formed of the laminated 35 sheet 50, which intercepts all the finer impurities.

Referring particularly to Fig. 1, also Fig. 6, it will be seen that there are a plurality of vertical channels such as 60—63, which are formed by the corrugated strip 51. These channels are 40 closed at the top by the laminated sheet 50, but are open,, at the bottom, and are arranged in spiral formation within the cartridge. That is, a horizontal section of the cartridge would reveal a system comprising a large plurality of 45 these channels in a spiral starting at the margin of the waste filling 28 and expanding outward to the wall 25 of the cartridge. There is also a second spiral system of vertical channels such as the channels 64—67, which are open at the 50 top and closed at the bottom, and which are formed by the corrugated strip 52. The two channel systems are separated by the laminated sheet 50.

After the oil has passed the fibrous material ₅₅ 27, it enters the vertical channels 60—63 and flows upward, filling these channels. As soon as the first channel system is filled, pressure develops, which forces the oil through the laminated sheet 50 into the second channel system which includes channels such as 64—67. The oil reaches ⁰⁰ the second channel system as clean oil and then passes through the layers of felt 29 and 30 and the intervening layer of ground bone 30. The felt layers are provided to retain the ground bone, which functions to remove the fatty acids ⁰⁵ which may be formed to some extent by decomposition of the oil.

It 'will be seen from the foregoing that the arrangement comprising the rolled laminated „ sheet 50 with the interspersed layers of corrugated fiber board 51 and 52 provides a large filtering area within a comparatively small space.

The large filtering, area enables the filtering material to pass a large quantity of oil per min75 ute, considerably more than can flow through

2,328,131 the opening 11 in the top of the cartridge. The size of this opening therefore determines the filter output under normal conditions. As dirt and Impurities accumulate, the sheet 50 will gradually become clogged up and gradually the capacity of the filtering material for passing oil will be reduced. Eventually the filtering capacity will fall below the outlet capacity and will approach the capacity of the small opening 9 in spring 8. At the point where the opening 9 can handle all the oil that comes through, the oil will, of course, cease to exert any upward pressure on spring 8. Some time before this point is reached, however, the tension of the spring will overcome the oil pressure and the spring will again come into engagement with the· top of the cartridge, re-closing the circuit of lamp L. The driver is thus notified that the filter is not functioning properly and that a new cartridge should be inserted. The relative size of openings II and 9 and the tension of spring 8 are so adjusted with regard to the life of the filter cartridge that the lamp L will be lighted as soon as the cartridge has become clogged to an extent which seriously impairs its efficiency.

The filter cartridge can be exchanged for a new one at any time in a very simple manner. When the motor is not running, there is no oil pressure, and the oil in the sump will drain back through inlet pipe 18, except for a small quantity below the level of the pipe. On unscrewing the bolt . 44, the pressure against the cartridge is relieved, and it can readily be broken away from the gasket 21 at the bottom and the gasket 10 at the top. These gaskets are preferably large enough so that they are retained by the surrounding rims of the stampings 15 and 2. As soon as the seal is broken at the gaskets, the oil above the cartridge will flow down the sides thereof into the sump whence it is drained off by pipe 18. The steel stamping 2 may now be raised sufficiently to allow the old cartridge to be removed. A new cartridge is then inserted; the steel stampings 2 and 15 are adjusted to the proper position if necessary; and the bolt 44 is tightened up again.

The new filter described and shown herein has many advantages over prior filters. One of the principal advantages is the reduced cost, which is due in part to the omission of the usual housing, and to the simplicity of the remaining parts. The filter cartridge is highly efficient, but is nevertheless inexpensive and can be replaced with facility when its useful life has expired. Finally, the arrangement of the signal lamp L gives the driver a continual check on the operation of the filter. . This lamp lights every time when the ignition is turned on preparatory to starting the motor and goes out when the motor starts, lighting up again, however, if the filter cartridge should become clogged. This arrangement, therefore, not only constitutes a warning system for giving notice of a defective filter cartridge, but insures that any defect in the warning system itself will be promptly made known to the operator by the failure of the lamp to light responsive to the closure of the ignition circuit.