Application of Andrew Alford

300 F.2d 929, 49 C.C.P.A. 1003

• Court: Court of Customs and Patent Appeals
• Decided: June 8, 1962
• Docket: Patent Appeal 6757
• Status: Published

Opinions

MARTIN, Judge.

This appeal is from the decision of the Patent Office Board of Appeals affirming the action of the Primary Examiner in refusing to allow claims 19, 20 and 22 of application Serial No. 596,-930, filed July 10, 1956, entitled “Coaxial Choke Coupler.” Claim 21, the only other claim in the application, was allowed by the examiner.

Claim 19 is representative of the appealed claims and reads as follows:

“19. A coaxial choke coupler for transmitting high frequency energy over a band in the range from 100 megacycles to 5000 megacycles about a mean frequency, said coupler comprising, coaxial inner and outer conductors, inner and outer insulating sections in said inner and outer conductors respectively, said sections dividing each conductor into first and second portions, said inner conductor insulating section being coextensive with the first and second portions of said inner conductor along the axis common to said conductors for a distance substantially equal to a quarter wavelength for energy in said center conductor insulating section of said mean frequency, said outer conductor having a pair of opposed spaced flanges at adjacent ends of said first and second portions thereof extending radially outward from an orthogonal to said common axis, said outer conductor insulating section being a thin annular disk orthogonal to said common axis with opposite sides in contact with both opposed faces of said spaced flanges for a radial distance substantially equal to a quarter wavelength for energy in said outer conductor insulating section at said mean frequency.”

Appellant’s application discloses a coaxial choke coupler for connecting two coaxial cable sections to transmit electrical energy therebetween at high frequencies of an order of 100 megacycles to 5000 megacycles. In connection with high frequencies, it is disclosed that the coupler operates with slight leakage and a minimum of impedance between the line sections. The application states:

“The devise of the present invention may have many uses, as for instance in mounting a high, ultra high, or super high frequency transmitter on top of a low frequency insulated radio tower. In this case the problem is to transmit these very high frequencies through the tower which is insulated and maintained at potential above the ground without disturbing the existing electric system.”

The coupler includes an inner conductor spaced concentrically within a hollow outer conductor with the conductors adapted for connection at each end to the corresponding conductors of one of the coaxial' cable portions to be interconnected. A longitudinal or sleeve type insulating joint having a length corresponding to a quarter wavelength at the mean or average frequency to be transmitted is interposed midway in the inner conductor of the coupler. Interposed in the outer conductor is a radial or disc type insulating joint comprising two opposed disc members which extend orthogonally outward in spaced insulated relationship. The radial distance that the discs extend from the outer conductor portions is made equal to approximately a quarter wavelength at the mean frequency of the energy to be transmitted.

The application also discloses a modified construction referred to as a three stage coupler. That structure does not require description here since the additional features it involves are not recited in the claims on appeal.

The references relied on are:

June 4, 1946 Espley 2,401,344

October 19, 1948 Salisbury 2,451,876

February 17, 1948 Garfitt (British) 598,375

The Espley patent discloses a coaxial coupler for transmitting high frequency energy between two coaxial cable portions. Joint sections are interposed in both the inner and outer conductors of the coupler. The joint in the inner conductor is of the longitudinal type and is described as being a quarter wavelength in length. The joint in the outer conductor comprises a longitudinal sleeve section formed by an end portion of increased diameter coaxially surrounding the other end portion over a length corresponding to a quarter of a wavelength.

The Salisbury patent discloses a high frequency coaxial line coupler which, like that of Espley, utilizes sleeve type joints of a quarter wavelength in both the inner and outer conductors.

The British patent to Garfitt relates to a coupler for connecting two wave guide portions which are relatively offset or are arranged for relative angular movement. The coupler comprises a continuous central conductor having an end extending into the interior of each of the wave guide portions and an outer conductor which is separated into two sections and disposed concentrically about the central conductor between the surfaces of the wave guide portions. It is stated in the patent that the central conductor, “instead of being supported inside the outer conductor by spacers of solid dielectric material as is usual in the coaxial cable type of feeder,” is supported by a rectangular metal plate or septum secured to the inside of the outer conductor.

The construction of the outer conductor of Garfitt is described as follows:

“The outer conductor of the feeder arrangement 3 is split transversely into two coaxial parts S' and S" at a point clear of the septum 7, the parts S' and S" being fixed respectively to the waveguide portions 1 and 2. A capacity joint 8 is provided between the adjacent ends of the parts 3' and S" to reduce energy leakage. This may be of either of the forms illustrated in section in Figures 2 and 3. The spacing of the overlapping parts may be about 1 mm. and the length of the passage between them equal to about one quarter of a wavelength (of the transmitted energy in air).” [Emphasis ours.]

Figure 2, referred to in the quotation, shows a longitudinal or sleeve type joint in the outer conductor. Figure 3 shows a radial or disc type joint such as is employed in appellant’s coupler.

The examiner rejected the claims on the ground that use of a disc type coupling or joint in place of the sleeve type joint in the outer conductor of the coaxial couplers of Espley and Salisbury would be obvious to one skilled in the art in view of Garfitt’s showing of sleeve and disc type joints as alternatives for use in the outer conductor of his coupling device. In connection with that holding, the examiner stated:

“Applicant’s device and the references of record are all concerned with the passage of energy without substantial radiation. The inner conductor by its use of the quarter wavelength sleeve joint will appear as a solid conductor for the band of frequencies to be passed. Although the inner conductor of Garfitt is solid, its teaching of the alternative use of sleeve or disc coupling for the outer conductor is not impaired since the inner conductors of the primary references can also be considered as a solid conductor for the band of frequencies involved. Although Garfitt will not provide D.C. or low frequency isolization [isolation] both Espley and Salisbury will, and the rejection has been made on the combination of these references. It will be noted * * * that the couplings of Garfitt are used to reduce ‘energy leakage’ or radiation.”

It was further stated by the examiner that:

“The contention that the combination produces a new and unexpected result is not considered persuasive since the result set forth by applicant is inherent in the obvious combination of the references and hence does not confer patentability on the claimed combination. * *

In affirming the examiner’s rejection, the board stated:

“In our opinion the substitution of a radial type joint such as shown in Fig. 3 of Garfitt for the joints of the basic references would [be] obvious to one skilled in the art, since Garfitt teaches the interchangeable use of the longitudinal and radial choke joints for preventing radiation losses in a coaxial choke coupler.”

Appellant concedes that “the change made * * * in modifying a prior art coaxial choke coupler having sleeve joints in the inner and outer conductors to include a disc line joint instead of the sleeve joint in only the outer conductor is but a slight change mechanically.” He contends, however, that his coupler is not obvious under 35 U.S.C. 103, urging in support of the contention that the coupler provides new and unexpected results.

Relying on Loom Company v. Higgins, 105 U.S. 580, 26 L.Ed. 1177 and In re Ratti, 270 F.2d 810, 46 CCPA 976, appellant appears to take the position that the production of a new or improved result, rather than unobviousness, is the criterion to be applied to a rejection on a combination of references. However, these decisions, rendered more than seventy-five years apart, actually demonstrate, consistently with 35 U.S.C. § 103, that unobviousness is a requirement for patentability and that the results attained amount only to evidence which may be pertinent to the determination of whether that requirement is met.

Referring to the present case, appellant states:

“The new and unexpected results of the claimed invention are established by the affidavit * * * and accompanying Exhibit 1 * *

That exhibit, which reports tests said to have been made in 1950 under appellant’s guidance, includes a graph comparing leakage losses of a coaxial choke coupler having a disc joint in its outer conductor and a sleeve joint in its inner conductor with the losses of a coupler having sleeve joints in both its inner and outer conductors. Although the examiner and the board have questioned the significance of a comparative test between these two devices, they do not dispute appellant’s contention that the graph indicates that the tested device having a disc joint in its outer conductor had less leakage loss than the tested device using a sleeve joint in the outer conductor.

In referring to that exhibit, appellant’s attorney asks:

“Would a man of his stature have an engineering report prepared back in 1950 describing the differences in results between his invention and a comparable prior art device involving tedious careful measurements unless his sincere expert opinion was that the differences in results were unpredictable and at that time unexplainable ?”

Although appellant’s reason for having the report prepared is not itself material, we think that his attorney's query leads to consideration of the factors which are determinative of the controlling issue here. In 1950, the Espley, Salisbury and Garfitt patents had all recently become available to the public. A person of ordinary skill in the art, with the objective of providing a coaxial coupler for use in the range of frequencies here involved, would have found in Garfitt a suggestion that a disc type joint, as well as a sleeve type joint, could be used to reduce energy leakage or radiation from the separated outer conductor, such as the outer conductor of the Espley or Salisbury coupler. There being no disclosure in Garfitt that either one of these joints is more effective than the other in reducing leakage, it is our opinion that it would have been obvious to construct a coupler using each of the outer joints disclosed by that reference and make comparative tests of leakage to determine which construction was most effective for the purpose at hand. Upon the tests showing, as appellant’s report indicates they would, that the coupler with the disc joint permits less leakage, it would be obvious for the worker to choose that construction. As a matter of fact, the tests that appellant did make had that effect.

Appellant argues that the matter of maintaining low leakage is not the only problem associated with coaxial choke couplers. He states in his brief:

“In its decision affirming the Examiner, the Board of Appeals discussed only one of the problems associated with coaxial choke couplers, the problem of maintaining low leakage radiation from the exposed gap in the outer conductor * * *. The Board did not discuss the problem of maintaining a low VSWR¹ over a wide bandwidth in the high frequency range while intercoupling both the inner conductors and the outer conductors by a low effective series capacity (low capacity presents high impedance at low frequencies) to effectively isolate the two coaxial transmission lines, inter-coupled by the invention, at low frequencies * * *.

******

“We recognize and have always conceded that a disc line quarter wavelength choke joint is old. Its property of presenting a low impedance between conductors that it intercouples has long been recognized as the equivalent of the same property of a quarter wavelength sleeve joint. But the properties of a disc line joint different from those of a sleeve joint not recognized in the prior art are that it will radiate less leakage power with a wider gap while still coacting with an inner conductor sleeve joint to provide a coaxial choke coupler with a low VSWR over a wide bandwidth.”

We do not find appellant’s contentions to indicate error in the board’s decision. It is not disputed that the substitution of the quarter wavelength disc joint of Garfitt for the quarter wavelength sleeve joints in the outer conductors of the couplers of the basic references results in a coupler of the construction defined in the claims on appeal. The structure which is obvious from the prior art thus would, as indicated by the examiner, inherently provide the same results and properties as the device claimed by appellant.

Appellant’s arguments concerning maintenance of a low standing wave ratio are not persuasive for another reason also. Although the affidavit and exhibit, by which appellant states the “new and unexpected results of the claimed invention are established,” report measurements of the standing wave ratio of a coupler having a flange type joint, they do not provide a comparison with any other structure. Such measurements obviously fail to establish superiority as to that characteristic.

Appellant also argues that a disc joint permits the use of a wider gap. That argument is not significant since the application does not disclose a particular gap width or that this width should be greater than in a sleeve type joint.

The decision of the board is affirmed.

Affirmed.

1 . VSWR, not defined in the application, apparently is an abbreviation of voltage standing-wave ratio. See Radio Engineering, Terman, Third Edition, McGrawHill (1947), page 79, footnote 1 which reads:

“Standing-wave ratio as used here is expressed in terms of voltage (or current) and is sometimes referred to as voltage-standing wave ratio (abbreviated VSWR), to distinguish from the ratio expressed in terms of power (proportional to the square of the voltage).”

Standing-wave ratio is described in Terman as a measure of the relationship of reflected and incident waves in a transmission line.