In re Liddell

69 F.2d 370, 21 C.C.P.A. 939, 1934 CCPA LEXIS 35
CourtCourt of Customs and Patent Appeals
DecidedMarch 19, 1934
DocketNo. 3408
StatusPublished

This text of 69 F.2d 370 (In re Liddell) is published on Counsel Stack Legal Research, covering Court of Customs and Patent Appeals primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
In re Liddell, 69 F.2d 370, 21 C.C.P.A. 939, 1934 CCPA LEXIS 35 (ccpa 1934).

Opinion

-Geaham:, Presiding Judge,

delivered the opinion of the court:

The appellant filed an application in the United States Patent Office for a patent on certain alleged improvements in filters, particularly a filtering unit for the removal or recovering of solid substances suspended in fluids. Several claims were allowed, but claims 47, 48, 49, 50, 51, 52, and 53 were rejected by the examiner, which rejection was affirmed by the Board of Appeals. The claims are very lengthy. The Board of Appeals has cited claim 47 as typical. This claim reads as follows:

47. A hollow metal edge-filter having large filtering surface in relation to the mass of metal thereof, and having its free filtering area large in relation to its surface and divided into apertures of small dimension by metal parts that are of small dimension between said apertures and are of relatively larger dimension in a direction normal to said filtering surface and resistant to pressure in said direction, which comprises a continuous metal ribbon having narrow edges and relatively wide faces; the width of the ribbon bearing such relation to the thickness thereof that bending of the ribbon in the normal plane of the width thereof buckles the ribbon out of that plane; the ribbon having a uniform curvature in the plane of its width and the metal of the ribbon being permanently set, thereby rendering permanent said curvature, and one wide face of the ribbon being provided with irregularities; the ribbon being in the form of a 'hollow substantially cylindrical helix comprising a multiplicity of turns with the width of the ribbon substantially normal to the axis .of the helix; the curvature of the helix in a plane normal to the axis thereof [940]*940bearing such relation to tbe permanent curvature of tlie ribbon in tbe normal plane of its width that tbe ribbon constituting tbe helix lies in nonbuckled form, with all parts of the plane of the width of the ribbon substantially normal to the axis of tbe helix, with the edges of the successive turns of the ribbon in substantial alinement and with the wide faces of successive turns of the ribbon in opposed relation and said irregularities engaging the opposed face of an adjacent turn of the ribbon and in part spacing adjacent turns of the ribbon; and means for holding said turns of the ribbon against relative movement.

Appellant’s device consists of a combination of elements, the particular device which is shown by his disclosure being constructed and adapted for use as an oil filter in internal combustion engines. The device consists of a cylinder enclosing a filtering unit. The cylinder has an inlet for the fluid to be filtered, through which the oil or other substance enters. After the oil is forced through the filter, an outlet is provided through which the oil can leave the cylinder and enter into the oil circulation of the engine. The filter unit comprises a cylinder, the walls of the cylinder being a helix formed from a flat metal ribbon, which ribbon is quite thin in relation to its width, and is provided with projections of predetermined height extending from one face thereof. The ribbon is preferably preformed, with one edge longer than the other, so that the ribbon has a definite uniform curvature, thereby allowing it to be formed into a helix with its faces transverse to the axis of the helix and with the projections of one turn in contact with the smooth face of the adjacent turn. Such an arrangement creates a series of small, narrow, elongated openings through the walls of the filter unit, by means of which oil or fluid entering the interior of the cylinder may be forced through these small openings, which openings are so sized that solid material contained in the fluid may be retained by the wall of the filter unit.

The fluid to be filtered may be passed from the outside inwardly between the turns of the helix, or from the inside outwardly, but the inventor states in his specification that he prefers the former arrangement to facilitate cleaning of the filtering unit. The metal ribbon is preferably so formed that it is thinner in the direction in which the fluid is flowing, so that the apertures have diverging walls and there is less liability of the clogging of the filter. Various methods of sustaining the flat ribbon helix are shown in the application. In one form of the device the caps at the ends of the filter are held against the opposite end turns of the helix by means of tie rods which extend the entire length of the filter unit, inside of the helix and in contact with it. In another form, a fluted drum similarly located is used. In another form, the adjacent turns of the helix are secured to each other by means of solder..

[941]*941The tribunals of the Patent Office rejected the claims in issue here on the following references:

Evans, 207802, Sept. 10, 1878.
LaicUaw, 456829, July 28, 1891.
Eynon, 491341, Feb. 7, 1893.
King, 765182, July 19, 1904.
Gobbi (British), 30303, Dec. 28, 1909.
Coates (British), 282846, Jan. 5, 1928.
Swedish patent, 62832, Apr. 27, 1927.

The Board of Appeals has found that as to the shaping of the thin ribbon which composes the helix, the principal reference is the Gobbi patent. However, the rejection of the claims in issue here rests not upon the Gobbi patent exclusively, but upon various elements disclosed in all of the references cited.

An examination of these references will, we think, show that the various elements which make up the combination here involved are disclosed by the references cited. The Gobbi patent discloses a filter of circular form, built up of a “ spiral metallic ribbon or plate, so that the spirals are superposed, these spirals having on one side interstices separating each of the turns of the spiral, by which the filtration is effected.” The drawings accompanying this patent disclose a formation of this ribbon of metal of the same character as that involved here, each superposed spiral being supported on projections extending radially across the width of the ribbon. The principal controversy about this reference arises from the claim of the appellant that Gobbi does not show these ribbon elements to be arranged in the form of a hollow substantially cylindrical helix.” It is thought by the appellant that inasmuch as Gobbi describes his ribbon element to be arranged in a spiral, that this does not support the language “ substantially cylindrical helix.”

The word “ spiral ” is thus defined in Webster’s New International Dictionary (1932) :

Spiral 1. Geom. a. The path (generally plain) of a point that moves round an axis while continuously receding from (or approaching) it. b. A helix.

The word “ helix ” is thus defined by the same lexicographer:

Helix 1. Aything having a spiral form, as an electrical conducting coil ;***&. Math. The curve formed on any cylinder, esp. a right circular cylinder, by a right line in a plane that is wrapped round the cylinder, as an ordinary screw thread; any curve, on a developable surface, that rolls out into a right line when the surface is flattened out upon a plane.

As to this feature, the Board of Appeals states:

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69 F.2d 370, 21 C.C.P.A. 939, 1934 CCPA LEXIS 35, Counsel Stack Legal Research, https://law.counselstack.com/opinion/in-re-liddell-ccpa-1934.