US2373349A - Oil purifying and cooling system - Google Patents

Description

April 10, 1945. J. J. SERRELL OIL PURIFYING AND COOLING SYSTEM Filed July 4, 1942 2 Sheets-Sheet 1 1M PURE OEL.

COOLER.

(.aE iL \MDURE OIL.

FICTTL IQ mum NG' INVENTOR John J. Sex Yell BY WQ A TTORNE Y Filed July 4, 1942 2 Sheets-Sheet 2 INVENTOR John J. Ser f-1L BYWQ ATTORNEY Patented Apr. 10, 1945 2,313,349 on. PURIFYING AND COOLING SYSTEM John J. Serrell, Philadelphia, Pa., asslgnor to Sharples Corporation, Philadelphia, Pa., a corporation of Delaware Application-July 4,1942, Serial No. 449,831

19 Claims. (Cl. 233-11) The present invention pertains to an oil purifying system designed to remove impurities from used oil and condition it for re-use, by treatment of this oil in a circulating system including an oil purifier, which may be a centrifugal separator, and a cooler. While the invention maybe employed in 'oil purifying systems used in'garious combinations, it was'conceived for use in' min: nection with a purifying system associated with the motor of a vehicle, such as an airplane, and can best be understood by discussion of problems incident to such a combination.

The invention, in its broader aspects, may be used in connection with the type of cooling and purifying system described in the prior application to Leo D. Jones, Serial No. 319,587, filed February 19, 1940, or in that covered by Leo D. Jones application, Serial No. 390,462, filed April 26, 1941.

The nature and importance of the present invention, in two of its principal embodiments as described hereinafter, can best be understood by e of the 30 pounds a preliminary consideration of problems. arising in purification and cooling of aviation engine oil by passage of that oil by means of the scavenge pump of the aviation engine through means for cooling and centrifugally purifying the oil. In this connection, we shall first discuss problems involved in passage of the oil through a purifying system involving a cooler and centrifugal separator, in the order named, toa storage tank, in accordance with the prior application of Leo D. Jones, Serial No. 319,587.

In a system of this kind, it is desirable that the total pressure developed at the scavenge pump be below a certain permissible maximum. which may, for the purposes of our discussion, be considered as arbitrarily set at 30 pounds per square inch. A certain minimum drop in pressure through the centrifugal (or other type of purifier) is inevitable. and in cases in which the centrifugal rotor is driven by the turbo action of the oil flowing through it, as in that application, this drop in pressure may be in the neighborhood of 15 to pounds per square inch under most operating conditions. In addition to this drop in pressure in passing through the rotor of the centrifuga1. there is a drop in pressure due to the resistance to flow of the oil through the o l cooler, and a further small drop-due to resistance in the conduits connecting the scavenge pump, cooler, centrifugal and storage tank, respectively. There is no difficulty in operation of such a system under normal conditions of operation, since the sum of the pressure drops across the individual elements of the system in passing from the scavenge pump through the purifying and cooling elements to the storage tank does not exceed the permissible 30 pounds per square inch pressure at the scavenge pump.-

Certain conditions of operation may, however, serve to cause an increase in the resistance of the elements of the system through which theoil passes, with the result that a pressure in excess limit must be developed if the oil is to be passed through all of these elements. The system must'accordingly be designed to provide relief under such a condition.

. One proposal for solving this difliculty is that involved in Carter Patent 1,711,658, in which both the centrifugal and the oil cooler are bypassed in case the pressure at a point in the line of flow in advance of these elements exceeds the predetermined permissible limit. This solution is not acceptable; however, for the adoption of such an arrangement entails omission of the cooling operation. It is only. necessary for us to imagine a condition in which the relief valve spring is broken or in which some impediment in the line of flow of liquid through the centrifugal occurs, in order to comprehend the disastrous consequences which might result from use of a system in which the cooler is by-passed whenever the centrifugal is by-passed. While there is no harm in by-passing the oil around the cooler at times in the cycle of operation when the resistance to flow through the centrifugal is high because of the high viscosity of the 011 due to coldness thereof, if the centrifugal and cooler should be by-passed simultaneously due to cloggage or spring breakage at a stage in the engine operation when oil which is hot enough to require cooling in being passed through the system by the scavenge pump,.failure of the motor would be a probable result, 7

Another conceivable solution of this problem would be to place the cooler at a point in advance of the centrifugal in the line of flow of the oil through the cooling and purifying system, and provide a relief valve for by-passing the centrifugal in case the pressure in advance of the centrifugal exceeds a predetermined limit. By operating in this manner, oil would be passed through the cooler at all times, but it would be passed I through the centrifugal rotor only at the times when the resistance through the centrifugal exceeded a pre-determlned maximum. Such a system is also subject to a serious objection, since the particular amount of pressure drop in passing through the centrifugal is not the critical factor, the important thing being to maintain the total maximum.

Any attempt to solve the problem by arranging the centrifugal in advance of the cooler and bypassing the centrifugal by a relief valve controlled by the pressure drop across the centrifugal would also be inadequate, for the same reason discussed immediately above.

The present invention provides a system by which all of the above difliculties are avoided. It includes within its broad scope arrangements in which the cooler may be placed either in advance of or beyond the centrifugal in the line of flow of the oil through. the system, but it provides means which will, in either case, effect byof the centrifugal without bypassing the cooler, this by-passing function being controlled by the total pressure developed in the system in the neighborhood of the scavenging pump, regardless of the relative location of the centrifugal and the cooler.

A more complete understanding of the invention may be had by referenc to the following detailed description in the light of the attached drawings, in which,

Figure l is a flow sheet illustrating the system of the invention as applied in a combination in which the cooler precedes the centrifugal in the line of flow,

Figure 2 illustrates a system in which the re- 1 lative positions of the cooler and centrifugal are reversed as compared to Figure 1,

Figure 3 illustrates a valve and centrifugal combination designed for practice of the invention in accordance with Figure 1 (parts being shown diagrammatically in this figure) and Figure 4 is a detailed cross section illustrating details of a valve and centrifugal combination designed for practice of the invention in accordance with Figure 2 of the drawings.

In the form of the invention illustrated in Figure 1 of the drawings, the impure oil is removed from the source III, which may be the crank case of an engine, but a pump II, which may be the scavenging pump of the engine. This oil is passed through the cooler l2 and valve It to a centrifugal II, where it is subjected to centrifugation to remove impurities. Oil discharged from the centrifugal I: is passed to storage tank I, from which it may be returned to the engine for re-use as desired.

A by-pass line ll connects the valve It with a part of the system beyond the centrifugal i3.

response to the pressure of oil whose pressure has been reduced by flow through the cooler ii, the valve It will be actuated to cutout the cantrifugal and thus keep the pressure within the desired limit, any time that this pressure-threatens to exceed that limit.

The detailed operation of the valve It will be evident from consideration of Figure 3 of the drawings. As here illustrated, this valve is built into thecasing surrounding the centrifugal, and is connected with the feed nozzle of the centrifugal in such a way as to by-pass oil around the centrifugal (i. e., the rotor) through the casing to the discharge point from the casing, upon development of a pre-determined pressure at the scavenging pump it. As here illustrated, the conduit II which interconnects the cooler I! with the centrifugal I I communicates with a valve housing ll formed in the upper portion 3| of the centrifugal casing. This valve housing. is provided with a cylindrical valve-containing chamber adapted to serve as a guide for the movement of a valve cylinder 32, During the normal passage oi oil through the cooler l2 and centrifugal ll, this valve cylinder is forced into the righthand position illustrated in Figure 3 of the drawings b the pressure of the spring 38 against an inwardly projecting flange ll of the valve. when the valve is in this position, oil from conduit ll enters the annular passage ll defined by annular flanges between which the valve cylinder 32 is adapted to slide, and the oil passes from this annular passage into the nozzle 88 through which it is fed to the centrifugal rotor it. After pin-incation in this rotor by means of the rotation thereof to effect centrifugation of the oil, it is discharged into the casing 31 surrounding the rotor and passes thence through conduit is to storage tank ll.

The valve cylinder 32 is provided with slots II along a Portion of its length, the cylinder being retained by spring a in a position in which these slots are out of communication with the annular passage 38 during normal feed of the oil through the centrifugal. The conduit is (Figures 1 and 3) is interconnected with a liquid receiving space adjacent the closed end I! of the valve cylinder 11, and liquid from this conduit is accordingly forced into contact with the head I! of the valve -32. -As long as the pressure exerted against the outer side of the head II by the liquid from conduit II is not greater than that exerted in an opposite direction against the valve by the spring 33,

The by-pass line I! may, for example, connect with the conduit leading from centrifugal II to storage tank II, or it may pass oil directly into the storage tank. The system is designed for passage of the oil, under all normal conditions of operation, through the centrifugal l3, but it includes special provision for actuation of the valve I, in case the pressure at the scavenging pump reaches a pre-determined limit, for by-passing oil through the conduit I! (which may be the interior of the centrifugal casing) to the extent necessary to prevent development of prohibitive pressure. To this end, a branch conduit I! interconnects a portion of the conduit between scavenging pump II and cooler II with the valve l6, and serves to actuate this valve to by-pass oil to conduit [1. whenever the pressure in the conduit it reaches the pre-determined limit. By controlling the by-passing function of the valve IS in response to the pressure in the conduit [5 (which is practically the same as the pressure at the pump l I), instead of controlling this valve in this valve will maintain the. position illustrated in I the drawings. The spring 33 exerts a force against this valve adjusted to oflset the effect of any pressure up to the maximum pressure permissible ill at the zone of communication of the conduit I! with the head I! of this valve. When the pressure from the conduit i6 exceeds this pre-determined pressure, the valve 32 will move toward the left with respect to the other parts illustrated in Figure 3, with the result that the slots II in the valve cylinder 32 will bring the space 35 into .communication through separate outlets I with the space surrounding the rotor in the centrifugal casing, with the result that the oil passed from the space 35 directly through the outlets 40 is by-passed around the centrifugal directly to the discharge conduit I! from the casing 81, without being passed through the rotor. Sufllcient oil will thus be by-passed, at the same time that a -part of the oil may be passing through the centrifugal rotor, to relieve the pressure which might otherwise b built up at the scavenging pump ll,

within the bellows and the exterior thereof.

asvaass thus achieving the result of bv-passing the centrlfugal in response to the pressure at the scavenging pump. instead of in response to the pressure in the conduit through which the oil flows from the cooler toward the centrifugal.

Figure 2 illustrates a modification of the invention in -which the centrifugal is mounted in advance of the cooler. As here illustrated, impure oil from the crank case .or other container 2. is passed by the scavenge or other pump II through a valve to a centrifugal 22, where it is purified, and the purified oil discharged from the centrifugal is passed from the centrifugal casing through cooler II to storage tank 24. In

practice of the invention in accordance with this system, the oil maybe discharged through the cooler 23 under the pressure of gas incorporated in the oil by the scavenge pump, this gas accumulating in a gas-proof centrifugal. In this embodiment of the inven-, tion, a by-pass conduit 2! interconnects the valve 25 with a portion of thesystem through which it is fed to the cooler '13, without being passed through thecentrifugal 22. The provision of an ordinary by-pass valve. would not be satisfactory for this purpose, since such valves ordinarily operate in response to differences in pressure between an upstream and downstream portion of the liquidunder treatment. In the present instance, if the by-pass. valve is to protect the scavenging pump 2i, it must prevent development of an excessive pressure at the scavenging pump, regardless of the pressure in other parts of the system. The by -passing function is accordingly controlled by the difference between the pressure P in the line connecting the scavenging pump with the valve -25 and the pressure p, which may be the pressure of the ambient atmosphere or some pre-determ'ined and definite pressure less than the maximum permissible pressure, but must not be a pressure capableof varying to the extent that the pressure directly on the downstream'side ofthe valve It varies. The pressure 1) may, for example, be variable to the extent that the pressure in the conduit connecting the cooler 21 with the storage tank it varies, since the pressure prevailing in that conduit is ordinarily only slightly above that of the ambient atmosphere.

An example of a combination of an upper tion of the conduit connecting the cooler 23 with the storage tan II. There are two advantages from such a connection. In the first place, these portions of the system are under pressure which is ordinarily the ambient atmospheric pressure or a pressure very close thereto, with the result that the difference in pressures (P-p) between the conduit 58 and the conduit 51 connecting the scavenging pump with the valve 25 is substantially equal to (only, slightly less than) the total pressure at the scavenging pump. A spring 58 within tire bellows ll tends to force the valve 52 casing surrounding the portion of the centrifugal casing with a valve designed for practice of the invention in accordance with Figure 2 is there illustrated, the valve mechanism is mounted on the upper portion ll of the centrifugal casing as in Figure 3, and oil from the scavenging pump under pressure P is adapted to be fed into the valve housing through a connection 5|. Theconnection I communicates directly with a connection ii to the feed nozzle of the centrifugal, which corresponds to the conduit 21 of Figure 2 of the' drawings. A relief valve 52 co-operates with a valve seat 53 to prevent by-passing of the oil with respect to the centrifugal as long as the pressure P is below the pre-determined maximum. A bellows N is secured to the valve 52 and is also secured at 55 to the casing surrounding the bellows in such a manner as'to prevent leakage of gas or liquid between the space A conduit 56 interconnects a portion of the valve casing communicatin with the interior of the bellows N with, a zone of substantially constant pressure. This conduit may, for example, be connected with the storage tank 2! or with a porillustrated in Figure 4. As

against its seat. When the pressure on the oil entering the connection Ill provides suflicient force against the valve 52 to overcome the opposite force of the spring 58 and whatever pressure may exist within the bellows at 2-5, the valve 52 will be forced from its seat and oil by-passed around the centrifugal as indicated by the arrow 2 and the corresponding line on Figure 2 of the flow sheet. In this embodiment as in the embodiment of Figures 1 and 3, it will thus be seen that the centrifugal is by-passed at any time at which the total pressure at the pump ll exceeds the predetermined limit, and in this embodiment also, the performance of the by-passlng function is dependent upon the total pressure at the scavenging pump, rather than upon any local difference in pressure between the parts of the system immediately in advance of and immediatel beyond the by-pass valve.

Instead of venting the interior of the bellows 54' to atmospheric or some other relatively fixed pressure, the end of this bellows opposite to the valve 52 may be closed and sealed at any given atmospheric, sub-atmospheric or super-atmospheric pressure, so long as that pressure is sufficiently low to permit the valve 52 to open when the pressure in the conduit 51 exceeds the set limit. If the bellows is closed and sealed in this manner, the conduit 56 may be omitted, and the spring 58 may also be omitted if desired. In such case, the closed end of the bellows will, of course, be positioned against some fixed abutment in the valve housing, since the pressure within the be]- lows is dependent upon its volume, after the amount of gas which it contains is once fixed.

Various modifications are possible within the scope of the invention, and I do not therefore wish to be limited except by the following claims.

I claim:

1. In an oil purifying system, the combination comprising as elements an oil cooler, an oil puriher, a pump for impelling oil through both said purifier and said cooler, and means responsive to development of a pre-determined pressure at a part of said system between said pump and the first of said elements to which saidoillis passed from said pump for causing the oil to by-pass said purifier, without by-passing said cooler, said part of said system between said pump and said cooler for causing the oil to by-pass said purifier without by-passing said cooler, said means being independent of the pressure in said system between said purifier and said cooler.

3. In an oil purifying system, the combination 4 I I p comprising as elements fier, a pump for impelling oil through be I cooler for causing I tween said purifier an oil cooler, an oil purl fi'er, a pump for impelling oil through said purifier and said cooler, and means responsive to thedifi'ercnce between the system'between said pump and the first of said pressure at a part of said tion comprising elements to which said oil is passed from said pump and the pressure at a part of said system through which said oil through both of said elements for causing the oil to by-pass said purifier without by-passing said cooler. I I

I 4. An oil purifying ystem as defined in claim 3 in which the oil is passed. through said purifier before being passed through said cooler.

5. an oil purifying system as defined in claim 3 in fore being passed through said purifier.

6. In an oil purifying system, the combination comprising as elements an oil cooler, an oil purie fier, a pump for impelling oil through both said purifier and said cooler, and a valve responsive to development of a pre-determined pressure at a part of said system between said pump and the I first of said elements to which said oil is passed fromsaid pump for causing the oil to by-pa'ss said purifier without ivy-passing said cooler, said valve being independent of the pressure in said system between said purifier and said cooler.

7. In an oil purifying system, the combination comprising as elements an oil cooler, an oil purisaid purifier and said cooler by conduits through which said oil is passed first to said cooler and then to said purifier, and a valve responsive to development of a pre-determined pressure at a part of said system between said pump and said the oil to by-pass said purifier without by-passing said cooler, said valve being independent of the pressure in said system "between said purifier and said cooler.

8. In an oil purifying system, the combination comprising as elements an oil cooler, a centrifugal oil purifier, a pump for impelling oil through both said purifier and said cooler, sive to development of a pre-determined pressure at a part of said system between said pump and the first of said elements to which said oil is passed from said pump for causing the oil to bypass said purifier without b -passing said cooler, said means being independent of the pressure in said system between said purifier and said cooler.

9. In an oil purifying system, the combination comprising as elements an oil cooler, a centrifugal oil purifier, a pump for impelling oil through both said purifier and said cooler by conduits through which said oil is passed first to said cooler and then to said purifier, and means responsive to development of a pre-determined pressure at a part of said system between said pump and said cooler for causing the oil to by-pass said purifier without by-passing said cooler, said means being independent of the pressure in said system beand said'cooler.

10. In a liquid purifying system, the combination comprising as elements a liquid cooler, a liquid purifier, a pump for impelling liquid through said purifier and said cooler, and means responsive to development of a predetermined pressure at a part of said system between said pump and the first of said liquid is passed from said pump for causing the liquid to by-pass said purifier without bypassing said cooler, said means being independent of the pressure in said system between said purifier and said cooler.

fiows after passing which the oil is passed through said cooler beand means responsaid elements to which stream from said pump and purifier and. said 11. In a liquid purifying system, the combinaas" elements a liquid cooler. a D D upstream from both'said cooler I'for impelling liquid purifier and said cooler, a valve liquid purifying system downliquid purifier, a

through both said interposed in said stream for said ifier, one portion of. said valve being connected to a portion of said system upstream from both said purifier and saidIcooler and another portion of said valve being connected to a portion of said system downstream from both saidpurifier and and downstream parts of said system for causing said valve to be operated to by-pass said purifier without by-pa'ssing said cooler when said pressure difference 12. In a exceeds a predetermined limit.

interposed in said liquid purifying system downstream from said pump and cooler and upstream connected to a portion from both said purifier of said system upstream and said cooler and an other portion of said valve being connected to a portionoi" said system downstream from both said purifier and said cooler, and means responsive to the difierence in pressure at the parts of said valve connected to the aforementioned respective parts of said system upstream from IbOth said purifier and said cooler and downstream from bothsaid purifier and said cooler for causing said valve to be operated to by-pass said purifier without. by-passing said cooler when said pressure difference exceeds a predetermined limit.

13. In a liquid purifying system, the combination comprising as elements a liquid .cooler, a liquid purifier, a pump upstream from both said purifier and said cooler for through both said purifier and said cooler by cond ts through which liquid is passed first to said purifier and then to said cooler, a valve interposed in said liquid purifying system downupstream from said purifier, one portion of said valve being connected to a portion of said system upstream from both said purifier and said cooler and another portion of said valve being connected to a portion of said system downstream from both said purifier and said cooler, and means responsive to the difference in pressure at the parts of said valve connected to the aforementioned parts of said system upstream from both said purifier and said cooler and downstream from both said purifier and said cooler for causing said valve to be operated to by-pass said purifier without by-passing said cooler when said pressure difference exceeds a predetermined limit.

14. In a liquid purifying system, the combination comprising as elements a liquid cooler, a

liquid purifier, a pump upstream from both said pump and upstream from said pursaid purifier and said cooler, and means responsive to the pressure at the part of said valve connected to said portion of the system upstream from both said purifier and said cooler for causing said valve to be operated to by-pass said purifier without by-passing said cooler when said pressure exceeds a predetermined limit.

15. In a liquid purifying syste the combination comprising as elements a liquid cooler, a liquid purifier, a pump upstream from both said purifier and said cooler for impelling liquid through both said purifier and said cooler by conduits through which said liquid is passed first to said cooler and then to said purifier, a valve interposed in said liquid purifying system downstream from said pump and cooler and upstream from said purifier, one portion of said valve being connected to a portion of said system upstream from both said purifier and said cooler, and means responsive to the pressure at the part of said valve connected to said portion of the system upstream from both said purifier and said cooler for causing said valve to be operated to by-pass said purifier without thy-passing said cooler when said pressure exceeds a predetermined limit.

16. In a liquid purifying system, the combination comprising as elements a liquid cooler, a liquid purifier, a pump upstream from both said purifier and said cooler for impelling liquid through both said purifier and said cooler by conduits through which liquid is passed first to said purifier and then to said cooler, a valve interposed in said liquid purifying system downstream from said pump and upstream from said purifier, one portion of said valve being connected to a portion of said system upstream from both said purifier and said cooler, and means responsive to pressure at the part of said valve connected to said portion of the system upstream from said purifier for causing said valve to be operated to by-pass said purifier without by-passlng said cooler when said pressure exceeds a predetermined limit.

17. In an oil purifying system, the combination comprising as elements an oil cooler, an oil purifier, a pump for impelling oil through said purifier and said cooler, and means responsive to the difference between, the pressure at a part of said system betwen said pump and the first of said elements to which said oil is passed from said pump and a pressure at least as low as the pressure at a part of said system through which said oil flows after passing through both of said elements for causing the oil to by-pass said purifier without by-passing said cooler.

18. An oil purifying system as defined in claim 17 in which the" oil is passed through said purifier before being passed through said cooler.

19. An oil purifying system as defined in claim 1'7 in which the oil is passed through said cooler before being passed through said purifier.

JOHN J. SEER-ELL.

CEB'I'lFICA'IE 0F common.

Patent No. 2,37 ,51i9.

April '10-, 1.91.5.

JOHN J. SERRELL.

It is hereby certified tint error appears in the printed specification of the above-numbered patent requiring correction as follows: column, line Mr, for "but a" read "by a--;

and that the said Letters Patent should for the word "for" read --jfran-;

Page 2, first page 11., second column, line 7,

be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 31st day of July, A. D. 1915,

(Seal) Leslie Frazer Acting Conmissioner of Patents.

said purifier and said cooler, and means responsive to the pressure at the part of said valve connected to said portion of the system upstream from both said purifier and said cooler for causing said valve to be operated to by-pass said purifier without by-passing said cooler when said pressure exceeds a predetermined limit.

15. In a liquid purifying syste the combination comprising as elements a liquid cooler, a liquid purifier, a pump upstream from both said purifier and said cooler for impelling liquid through both said purifier and said cooler by conduits through which said liquid is passed first to said cooler and then to said purifier, a valve interposed in said liquid purifying system downstream from said pump and cooler and upstream from said purifier, one portion of said valve being connected to a portion of said system upstream from both said purifier and said cooler, and means responsive to the pressure at the part of said valve connected to said portion of the system upstream from both said purifier and said cooler for causing said valve to be operated to by-pass said purifier without thy-passing said cooler when said pressure exceeds a predetermined limit.

16. In a liquid purifying system, the combination comprising as elements a liquid cooler, a liquid purifier, a pump upstream from both said purifier and said cooler for impelling liquid through both said purifier and said cooler by conduits through which liquid is passed first to said purifier and then to said cooler, a valve interposed in said liquid purifying system downstream from said pump and upstream from said purifier, one portion of said valve being connected to a portion of said system upstream from both said purifier and said cooler, and means responsive to pressure at the part of said valve connected to said portion of the system upstream from said purifier for causing said valve to be operated to by-pass said purifier without by-passlng said cooler when said pressure exceeds a predetermined limit.

17. In an oil purifying system, the combination comprising as elements an oil cooler, an oil purifier, a pump for impelling oil through said purifier and said cooler, and means responsive to the difference between, the pressure at a part of said system betwen said pump and the first of said elements to which said oil is passed from said pump and a pressure at least as low as the pressure at a part of said system through which said oil flows after passing through both of said elements for causing the oil to by-pass said purifier without by-passing said cooler.

18. An oil purifying system as defined in claim 17 in which the" oil is passed through said purifier before being passed through said cooler.

19. An oil purifying system as defined in claim 1'7 in which the oil is passed through said cooler before being passed through said purifier.

JOHN J. SEER-ELL.

CEB'I'lFICA'IE 0F common.

Patent No. 2,37 ,51i9.

April '10-, 1.91.5.

JOHN J. SERRELL.

It is hereby certified tint error appears in the printed specification of the above-numbered patent requiring correction as follows: column, line Mr, for "but a" read "by a--;

and that the said Letters Patent should for the word "for" read --jfran-;

Page 2, first page 11., second column, line 7,

be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 31st day of July, A. D. 1915,

(Seal) Leslie Frazer Acting Conmissioner of Patents.

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