Application of Cletis L. Roberson

296 F.2d 484, 49 C.C.P.A. 784
CourtCourt of Customs and Patent Appeals
DecidedDecember 20, 1961
DocketPatent Appeal 6717
StatusPublished

This text of 296 F.2d 484 (Application of Cletis L. Roberson) 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
Application of Cletis L. Roberson, 296 F.2d 484, 49 C.C.P.A. 784 (ccpa 1961).

Opinion

MARTIN Judge ’ ’

. ,, , , This is an appeal from that part of a ÍT°n °f Üppea s. °* th/ Umted States Patent Office which affirmed the examiner s rejection of claims 7-9, 14, 15 and 18 of appellant s apphcation for a patent on “Production of Uniform Continuous Fibers of Thermoplastic Material. The board reversed the ex-arnmer as to his rejection of two claims an t eystan a owe .

^ ^ Claims 8 and 14 are illustrative and state:

“8. The method of producing continuous mineral fibers having end-to-end uniformity in diameter compnsmg providing a molten body of thermoplastic mineral material, flowing a stream of said material through a temperature-controlled zone, allowing said stream to cool on emission from said zone, attenuating said cooling stream directly from said zone into a continuous fiber, winding said fiber into a round package rotated at a uniform angular speed in a winder, said attenuation being effected by forces supplied by the winder acting on said fiber, and gradually decreasing the viscosity of successive adjacent portions of said stream as they pass through said zone by gradually increasing the' temperature of said zone to increase the rate of flow of material there-through in matched relation to the general rate of build up in diameter of the package.
“14. Fiber producing apparatus comprising in combination a container f or a molten body of thermoplastic material, an electrically'heated feeder associated with said container for forming a plurality of streams of said material, a rotary winder for attenuation of said streams into con- ' «nuous fibers and for winding said fibers into a package, a gathering device between said feeder and winder for grouping said fibers into a strand before being wound into said kage temperature-measuring means for measuring the temperature of said feeder and for aupply of control signals proportional to gaid temperature measurements, presettable control means arranged to receive said bontrol signals to regu_ ]ate the temperature of said feeder ftt a preset valu6; and means for sup. plying auxiliary signals to said control means to vary the temperature of said feeder in substantially matched relation to cyclic variations in the rate of attenuation of said fibers..”

The referenees relied on by tHe examiner and tbe board are. •

„ . „ Brenzmger 1>980,6 0 Nov. 13, 1934; Slaytei , 50,9 5 ar. 2, ^ , K me 2,214,332 Sept 10, 1940; Simison et a . 2,407,295 Sept 10 19-46; Dickey et al. 2,491,606 Dec. 20, 9 .

This application relates to the production of continuous mineral fibers by mechanical attenuation of streams flowing from a molten body of a thermoplastic mineral material such as glass. It appears to be common to form a plurality of continuous fibers, gather them into a single strand as they are formed, and *486 wind the strand in uniform layers on a rotating collection spool. The force for fiber attenuation is provided by the winder. It is stated to be customary to collect a strand on the rotating spool at linear speeds of 15,000 to 20,000 feet per minute for 15 to 30 minutes. The strand is then broken and the resulting strand package replaced with an empty collection spool.

When, as was apparently customary in the prior art, the collection spool is rotated at a uniform angular speed and the molten material held in the feeder at a uniform temperature, a gradual decrease in fiber diameter is observed during a collection cycle because, suggests appellant, the linear speed of attenuation is dependent on the diameter of the collection spool and this varies from its diameter when empty to the diameter of the completed package of spool plus collected fibers. Thus the linear speed of attenuation gradually increases during the collection cycle. Since the amount of molten material flowing as a stream through a spinning orifice is constant at a given temperature, the gradual increase in linear attenuation speed produces a gradual decrease in fiber diameter.

' Appellant’s problem was the production of mineral fibers of uniform diameter. Appellant appears to have solved this problem by gradually increasing the temperature of the thermoplastic material flowing from the feeder to match the increase in linear attenuation speed with package build-up. When a strand package of desired size has been collected, the material temperature is allowed to drop to its value at the start of the collection cycle and then collection of a fresh strand package is started. 1 ****According to appellant, the mineral material, particularly glass, becomes less viscous as its temperature is increased. Therefore, the material flows more and more freely from the feeder, thus meeting the gradually increasing demand for fiber material as the fiber attenuation speed increases. The result is a uniform fiber diameter.

It is this process of producing “continuous mineral fibers having end-to-end uniformity in diameter” which is recited in appealed claims 7-9.

Appellant also claims as his invention, apparatus for producing, fibers by the process of claims 7-9. The apparatus disclosed appears to include the usual container for molten material, an electrically-heated feeder to form a plurality of fiber-forming streams, a rotary winder to attenuate the partially formed fibers and collect the fibers after they have been gathered into a strand, and thermocouple means to sense the feeder temperature and send electrical signals to a control unit whereby the feeder can be maintained at a fixed predetermined temperature. In addition, appellant’s apparatus includes means for sending additional electrical signals into the temperature control circuit in accord with a predetermined time-intensity pattern so that the control unit will cause the feeder temperature to rise and fall during a strand collection cycle in accord with appellant’s method. As to this time-patterned auxiliary signal, appellant states that it “is arranged to oppose the thermocouple signal as it increases, to falsely indicate to the unit 29 2 that the temperature of the feeder is gradually diminishing. That is, the regulator unit receives a false temperature signal which causes it to allow the current flow through the feeder to gradually increase and consequently effect a gradual increase in temperature of the feeder.”

During a collection cycle, appellant programs the auxiliary signal so that it is gradually increased during a collection, raising the temperature of the feeder, for example, from 2300°F to 2315°F during 20 minutes, and then is cut off completely, allowing the feeder temperature to return to 2300°F during the few seconds neces *487 sary to replace the completed strand package with an empty collection spool.

Appellant discloses two specific auxiliary signal generators but it is not necessary to describe them since their details are not recited in the appealed claims.

The rejection of the appealed claims is based entirely on the obviousness of the claimed process and apparatus in view of a combination of prior art patents.

The principal reference relied on is Simison et al. which discloses a process and apparatus for forming glass fibers.

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296 F.2d 484, 49 C.C.P.A. 784, Counsel Stack Legal Research, https://law.counselstack.com/opinion/application-of-cletis-l-roberson-ccpa-1961.