APPLICATION OF RICE

MARTIN, Judge.

The question the court must answer in this appeal is whether appellants' novel air cleaner, as represented by claims 1, 2 and 3 of their application serial No. 816,556 entitled "Air Cleaner" filed on May 28, 1959, is an obvious variation of the devices of the prior art. No claims stand allowed in the application, which is stated to be a continuation-in-part of application serial No. 698,474 filed November 25, 1957 for an "air cleaner device."

The centrifugal air cleaner appellants disclose is useful on internal combustion engines or air-compressors, particularly under very dusty conditions. The air cleaner is of simple construction and is "self cleaning" in operation. Reference to the accompanying figures of the application will aid in an understanding of the structure and operation of the device:

Figure 1 shows the air cleaner consisting of separator portion 10 mounted on the air intake of an internal combustion engine such as that of a tractor, with a hose 15 connected to a vacuum developing portion or venturi 16 mounted on the engine exhaust. Cross section views of those two portions of the device are seen on the right and left of Figure 2. In operation, when the engine is running, air is drawn into the cleaner via cap 30 following the path indicated by arrows A and B. The air flows over inclined vanes 29 which impart a "spiral swirling motion" to it. As the air is drawn downward in its spinning path, entrained dirt is centrifugally thrown toward the outer wall 20 of the "tank" or can-shaped separator portion of the air cleaner. The dirt and some air enters collecting chamber 17 by passing through the space 26 between the wall 20 and baffle 25, while relatively clean air enters carburetor air intake 12 via tube 11. The air-entrained dirt passes out of chamber 17 into hose 15 as indicated by the arrow we have labeled C. The air and dirt is drawn out by the action of the venturi or vacuum developing device 16. Exhaust gases exit from the engine as shown by the arrow we have labeled E. As the gases pass through the tapered section 44 they draw the dust laden air from hose 15 as shown by the arrow we label D.

There is no question that the cleaner is operable and has achieved some degree of commercial success. However, it is our view that the appellants' claimed air cleaner1 is an obvious variation of the following references:

  Schutz              1,496,908    June    10, 1924
  Altgelt             2,033,368    March   10, 1936
  Société (French)    1,106,384    Dec.    19, 1955

The Altgelt reference is relied on to show a cap used on the intake of a tractor air cleaner. The reference is used only in conjunction with the rejection of claim 2, the sole claim calling for a cap.

The major reference, Société, describes "fluid separators operating by centrifugal force," to be used particularly for the separation of moisture from steam. The detailed description will be by way of reference to the drawing therein:

The drawing shows a tubular separator section or "connection" 1 which is the same size as the steam line to which it is connected by employing flanges 2 at either end. Helical fins 7 are mounted within the tubular section. Moist gases or steam flow downwardly in the direction of arrow A, while the helical surfaces produce "a rotation of the gas or steam current." A larger annular casing 3 is spaced around a slot 4 and funnel-shaped surface 5 and together define a collection chamber. Société states:

A valve "or usual condensate extraction device" is provided at outlet 6 to tap off the moisture that has been separated.

Schutz is directed to a "suction air cleaner" used for "eliminating dust from the air before it enters the carburetors of internal combustion engines," and which is "non-clogging in operation." The suction air cleaner of Schutz clearly is a centrifugal type cleaner, the dust laden air being caused to "whirl with high velocity" by tangential inlet projections or fins and the engine suction. The dust is ejected at the bottom of a downward path by use of a venturi, while the clean air is directed upwardly to the engine intake by a conical baffle. As we view the rejection of the examiner and the decision of the board, the Schutz reference was used for two purposes. First, to show the exhaust driven "Venturi tube" or vacuum developing device, and second, to show the concept of such a venturi device in combination with an air cleaner as the means by which dust is ejected.

Claims 1 and 3 were rejected by the examiner as "unpatentable over Société in view of Schutz," while claim 2 was so rejected "further in view of Altgelt," and the board affirmed. Since the differences in the claimed structure and that of the references are readily apparent, we take "unpatentable over" as meaning obvious within the meaning of 35 USC 103.

As will be apparent from their arguments discussed below, appellants seem to misconstrue the rejection. The differences in the separator portion of the structure claimed, as compared to that of Société, were deemed obvious by the examiner and the board, and we agree, while the combination of the separator portion with venturi and cap, and their use on internal combustion engines at normal air pressures are equally obvious to those in the art as shown by Schutz and Altgelt. With regard to the differences, the examiner and board are not combining the references by modifying the structure of Société by reference to structure shown in Altgelt or Schutz. With regard to the combination, it is evident that centrifugal separation operates on the differences in density between the carrier gas and the solid or liquid particles to be separated. The references thus cannot be said to be from non-analogous arts and thereby not combinable. We shall discuss these two aspects of the rejection separately below.

I The Differences

Appellants' major contention concerning the differences in their structure as compared to Société appears best summarized by the argument that:

Appellants, in supporting that position, urge certain differences between their device described as a "tank" and the Société device which is termed a "tube." We take these differences as merely verbal.

Appellants also point to various internal structural modifications that must be made in Société in order to overcome the claimed differences. While we have considered all the arguments, we will discuss only the major ones here.

Appellants point to the fact that the claimed collection chamber is radially spaced inside the walls of the main air chamber while that of Société is outside. This difference is not convincing since Société discloses:

Further, appellants have pointed to no results traceable to this feature which would indicate that it is other than an obvious matter of design choice.

Much discussion has been had by appellants and the examiner about the effect of the claim limitation:

After careful analysis and discussion of flow paths, air pressure and velocity, the examiner concluded that this limitation:

The gist of appellants' response is that:

We fail to see how such a general allegation in a brief can rebut the relationships between flow paths, air pressure and velocity stated by the examiner to be the same herein as in Société. The examiner analyzed, with reference to the well-known Bernoulli principle,2 the effect structural differences might have on the operation of appellants' device as compared to that of Société. Appellants do not challenge the statements as being incorrect, but assert that a reference by the examiner to the Bernoulli principle alone is not proper here. It was perhaps the best means available to the examiner of explaining the reasons for his conclusion of obviousness, and since unrebutted by factual evidence of any critical relationship in position or size, or of any difference in effect or result, we think the position of the examiner to be sound. Appellants have failed to show that the change in the vanes, the use of an inner rather than outer collection chamber and the use of a smaller output tube, for example, as compared to Société, result in a difference in function or give unexpected results. Such changes in design of the various features are no more than obvious variations consistent with the principles known in that art.

II The Combination

We see little merit in the objections to the combination of Altgelt, as showing the cap, and Schutz, as showing the venturi tube, with Société. As the board noted:

Although appellants contend the board erred in stating: "Appellants have presented no arguments indicating that these features are of particular significance to the particular separator structure shown," the present arguments are not well taken in view of appellants' reply brief before the board which stated: "Admittedly the cap is shown in Altgelt and a suction [a venturi tube] shown in Schutz." Appellants now urge that:

That description of what the cap does describes precisely what the cap in the air cleaner of Altgelt does. Contrary to appellants' contention, the vacuum inducing device is shown in the prior art.

We grant that Schutz does use his venturi in an alternative fashion, i. e., the exhaust and dust laden air inputs are reversed. The examiner in his answer pointed this out but stated:

We agree, and also note that Schutz teaches his arrangement to be a six to ten-fold improvement over the suction available by the very arrangement which appellants use.

We are satisfied that the cap and venturi elements emphasized by appellants are obvious additions which are taught by the Schutz and Altgelt references to be useful as a matter of choice in the combination. No unexpected result stems from their use in the combination; the combination works as expected.

Our view of this controversy is not changed by the many variations in the argument that the structure is novel. In view of the above we affirm the decision of the Board of Appeals.

Affirmed.

SMITH, J., concurs in the result.