In re Lundal

175 F.2d 446, 36 C.C.P.A. 1105
CourtCourt of Customs and Patent Appeals
DecidedJune 28, 1949
DocketNo. 5586
StatusPublished

This text of 175 F.2d 446 (In re Lundal) 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 Lundal, 175 F.2d 446, 36 C.C.P.A. 1105 (ccpa 1949).

Opinion

Jackson, Judge,

delivered the opinion of the court:

This appeal is from a decision of the Board of Appeals of the United States Patent Office affirming that of the Primary Examiner, finally rejecting all of the claims, 9 to 17, inclusive, 19 to 25, inclusive, and 28, of an application for a patent, serial No. 494,966, filed July 16, 1943, entitled “Separator and Separation Process,” as unpatentable over the cited prior art.

Claim 28 was further held by the board as failing to define a structure that will produce the result sought by appellant. Three article claims and two process claims were allowed.

The cited references are:

Strezynski, 1,893,005, January 3, 1933.
Strezynski, 2,022,814, December 3, 1935.
Hall, 2,214,831, September 17, 1940.

The device defined in the rejected claims is a centrifugal separator used in separating fractions of sour cream, which are concentrated butter fat, skim-milk and coagulated proteins. In the operation of the device, it is said that the free flow of the cream is not blocked or obstructed by the accumulation of unwanted materials, such as coagulated proteins.

The centrifuge, as shown in appellant’s drawing, comprises what is called a primary or interior separation chamber and a final or secondary outer separation chamber, both surrounded by a centrifugal bowl of the rotary type which forms the wall of the final separation chamber. The bowl rests upon, and is driven, by a tapered shaft which extends into a complementary conical hollow spindle. The spindle is [1106]*1106integral with the central portion of the lower wall of the outer separator bowl. The bowl is constructed so that the lower section thereof is joined to the upper section a short distance above a plane which is the maximum diameter of the bowl between its upper and lower extremities. Along the maximum diameter are a number of outlets through which the heaviest fraction of separation, such as coagulated proteins, may be discharged. Connected with the upper portion of the conical surface of the outer bowl is a conical cap section secured by a coupling which locks the upper and lower parts of the bowl together. At the top of the bowl, the wall tapers ;into a centrally formed neck portion, partially closed by a ring dam and a screw coupling. An outlet for the discharge of the intermediate fraction of separation, such as skim-milk, and another outlet for the discharge of the lighter fraction, such as concentrated cream or concentrated milk fat, are coaxial with the neck of the device. The centrifuge is fed by means of a tube which extends downwardly and centrally of the said neck. The lower portion of the tube is expanded outwardly, forming the primary or interior separation chamber. The secondary or final separation chamber is bounded by the wall of the infeed tube and the interior surface of the outer bowl. In the outer bowl are a series of stratifying or separating disks running through the middle thereof and held in position by vanes on the surface of the tube and vanes integral with the cap portion of the outer bowl. Through the wall of the primary separation chamber and running inwardly therefrom toward the axis of rotation are escape tubes designed as passageways for the lighter constituents from the primary chamber into what is called the neutral zone of the secondary separation chamber. The mouths of those tubes face directly aligned openings in all the stratifying disks, and that portion of the device consisting of those openings is said to be the neutral or intermediate zone.

It is stated that the interior ends of the escape tubes are placed closer to the axis of rotation than to the interior wall of the said tube for the reason that, as so constructed, material which has not been subjected to primary separation in the first or primary chamber is prevented from entering the tubes through which it could pass into the secondary separation chamber.

The centrifuge separator bowl disclosed by appellant is commonly known as a “balanced bowl.” That type of bowl is said to comprise the positioning of the apertures in the stratifying disks in the neutral zone for the materials being separated. It is further said that the neutral zone is determined by the prevailing static heads of the liquids of different specific gravity in the axial outlet tubes through which the concentrated cream and the skim milk are discharged. Near the bottom of the interior of the primary separating chamber are tubular [1107]*1107ports extending through the wall thereof, directly to the outer zone of the secondary chamber, at a point beyond the neutral zone, for the passage of the heavier fractions of separation. Those fractions after having passed into the secondary chamber, are extended by means of centrifugal force upwardly along the interior wall of that chamber until discharged at the passages which are placed around the device at its widest diameter. It is said that together with thé coagulated proteins, enough skim-milk passes so that the ports remain in a clean condition.

On the interior wall of the infeed tube, integral therewith, and extending lengthwise and inwardly thereof in a radial direction, are a number of vanes. They extend downwardly to the same number of the said discharge tubes.

The Strezynski patent, 1,893,005, relates to a balanced centrifugal-separator bowl and the device of the patent, as it appears from the drawing thereof, seems very similar to that defined in the rejected claims. There is disclosed a downwardly and centrally positioned feed tube with an expanded lower end forming the primary separation chamber. There is a secondary chamber formed by the outer wall of the device and the walls of the said tube and interior chamber. Within the secondary chamber there are stratifying disks and a neutral zone extending therethrough. The only material difference, in our opinion, between the device of the patent and that of appellant, is that the escape tubes from the primary to the secondary chamber do not face the neutral zone, and the passages for the heavier materials do not extend from the interior chamber beyond the neutral zone in the secondary chamber. The latter tubes face the neutral zone of the device. It is stated in the specification of the patent that,

In my improved bowl the portion of the lighter component which separates in the tubular shaft flows through the tubes r to the zone of lighter component inside the bowl so that the discs are required to separate from the heavier component only that portion of the lighter component which does not separate under the lesser centrifugal force in the tubular shaft.

The Strezynski patent, 2,022,814, likewise discloses a balanced centrifugal bowl. It was cited by the examiner as disclosing a discharge port for the heavier ingredients not shown in the former Strezynski patent. The examiner held that to provide the device of the former Strezynski patent with the peripheral discharge means disclosed in the latter Strezynski patent would not involve invention.

The Hall reference relates to a centrifuge for clarifying and standardizing milk. In the device of the patent milk is forced upwardly by means of a pump into a centrifuge through a tube and two small ports into a discharge tube which is expanded at its lower end. From [1108]*1108that end there is a discharge tube which does not extend beyond the vanes in the separating chamber.

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Bluebook (online)
175 F.2d 446, 36 C.C.P.A. 1105, Counsel Stack Legal Research, https://law.counselstack.com/opinion/in-re-lundal-ccpa-1949.