(dissenting in part).
I concur in the conclusion reached by the majority except with respect to claim 8. That claim, as noted in the majority opinion, is broad enough to cover a system in which the position of the by-pass valve is controlled by the flow through a single orifice, as well as one in which it is controlled by flow through two orifices. Jensen’s claim 11, on the other hand, is limited to a construction in which control is effected in accordance with the differential of pressures across two orifices.
It is apparent that appellant’s claim 8 is much broader than Jensen’s claim 11 and would cover structures differing radically from that to which the latter claim is limited. For example, claim 8 is readable on a system in which the movement of the valve is effected by exerting pressures from opposite sides of one of the orifices on opposite ends of the valve plunger and biasing the plunger by means of a spring assisting the pressure from the downstream side of the orifice, so that the valve will be held in normal operating position while the flow through the orifice is normal but will be shifted by the spring to bypassing position if there is a failure to flow through the orifice with a resultant equalization of the pressures on opposite sides of it. Clearly such a system would represent an invention entirely distinct from that of Jensen’s claim 11.
The fact that a broad claim embraces the subject matter of a narrower one does not, in itself, establish that the two are drawn to the same invention, and this court has repeatedly so held. In re Frey, 182 F.2d 184, 37 C.C.P.A., Patents, 1052; Andrews v. Wickenden, 194 F.2d 729, 39 C.C.P.A., Patents, 860; Emerson v. Beach, 215 F.2d 290, 42 C.C.P.A., Patents, 711. As clearly indicated by those cases, a difference in scope alone, if great enough, may be sufficient to preclude a holding that two claims are drawn to the same invention. While it is not expressly stated in those decisions it appears to be implicit therein that two claims differing only in scope are not directed to the same invention if the narrower one involves one or more features involving invention over what is claimed in the broader one. Here it seems apparent that the mere broad concept of controlling the valve position by the flow through a single orifice, as recited in appellant’s claim 8, would not in any way suggest the specific control by differential pressures across two orifices, to which Jensen’s claim 11 is limited. The latter claim, therefore, includes an inventive feature not found in the former and hence the two are not drawn to the same invention.
In evaluating claim 8 the majority appear to have given substantial weight *153to the fact that appellant does not actually disclose a system in which control of the valve is effected by one orifice only. In my opinion, that is not material here. Claim 8 is in no way ambiguous and must therefore be given the broadest interpretation it will reasonably support. In re Egan, 159 F.2d 452, 34 C.C.P.A., Patents, 843, and cases there cited. As was said in Graver Tank & Mfg. Co. v. Linde Air Products Co., 1949, 336 U.S. 271, 69 S.Ct. 535, 538, 93 L.Ed. 672, “It would accomplish little to require that claims be separately written if they are not to be separately read.” See also In re Cresswell, 187 F.2d 632, 38 C.C.P.A., Patents, 917, and cases there cited. Claim 8, as conceded in the majority opinion, is broad enough to cover the control of the valve by one orifice alone, and the fact that appellant does not specifically disclose a single orifice control should have no bearing on the scope of that claim or on the question as to whether it is for the same invention as claim 11 of Jensen. The latter question should be determined by a comparison of the claims themselves rather than the specific disclosures on which they happen to be based.
It should be noted that the majority recognized, in connection with its consideration of claim 10, that this court has held, in a case involving estoppel to copy claims from a patent for interference purposes (In re Frey, supra), that
“ * * * in the use of the word ‘covering’ in the case of Cryns v. Musher, supra [161 F.2d 217, 34 C.C.P.A., Patents, 963], there was no intention to hold that a broad claim which merely covers the invention of a patent claim is a claim to substantially the same invention as the patent claim so as to avoid es-toppel. * * *”
The majority characterizes the issue in that and like cases as “somewhat analogous” to that here involved but con-eludes that “claim 10 is not a broad which ‘merely covers’ the invention of Jensen’s claim 11.” In the majority’s consideration of claim 8, however, it completely ignores the rule set forth in the Frey case and, in fact, flies squarely in the teeth of that rule. When the majority states, as it does, that
“Claim 8 reads on a means which is responsive to flow through (pressure differentials at) two orifices because flow through two includes flow through one. Claim 8 does not say ‘only one’ and so it must be construed as meaning ‘at least one.’ ”
it is, in fact, saying that because claim 8 “covers” Jensen’s claim 11, it is drawn to the same invention.
I am of the opinion that the issue involved in the Frey case, supra, is more than merely “somewhat analogous” to that here involved; in essence, there is no difference between the two issues. In both cases, the question to be asked is: “are the claims drawn to substantially the same invention?” The ground rules that apply to one, therefore, should with equal force apply to the other.
Further to be noted is the fact that in In re Howard, 53 F.2d 896, 19 C.C.P.A., Patents, 759, this court approved the issuance of a patent to each of two inventors containing claims which differed only in scope, notwithstanding the fact that their disclosures were identical so far as the essential features claimed were concerned.
There is clearly nothing of record to show that the single-orifice control covered by appealed claim 8 is the equivalent, in patentable respects, of the specific two-orifice control to which Jensen’s claim 11 is limited. In my opinion, therefore, Jensen does not claim the invention of appealed claim 8, and the decision of the board with respect to that claim should be reversed.