Defendants, Bebry Bedding Corporation (Bebry) and R. H. Macy & Co., Inc. (Macy) appeal from a decree and order for injunction and accounting (judgment) wherein the trial court determined that plaintiff, Castro Convertible Corporation (Castro), is the owner of reissued Letters Patent No. 24,128 (reissue application date December 13, 1954; reissued March 13, 1956, replacing original Letters Patent No. 2,664,145 issued December 29, 1953), in the name of Catherine B. Creveling and Elmer L. Pennell (the Creveling patent); that claims 1, 2, 3, 4, 5, 6, 9 and 11, 12, 13 and 14 of Re No. 24,128 are valid and have been infringed by Bebry and Macy; that Letters Patent No. 2,785,416 issued to *307Bebry on March 19, 1957 (application filed December 3, 1953) and the claims therein are invalid; that Bebry’s counterclaims should be dismissed; that an injunction issue against defendants permanently enjoining them from infringing; and that defendants account to plaintiff for damages resulting from such infringement.
On this appeal appellant argues that the action must be considered as purely one of patent infringement and patent validity. Certain background facts bear upon a proper resolution of these issues presented.
Castro is a retailer of convertible furniture (convertible into beds) which it sells through a chain of 38 retail stores. Bebry since 1936 has been a manufacturer of such furniture. Macy is a large retail department store with branches selling such furniture.
In the summer of 1952, Mrs. Creveling and her co-inventor Mr. Pennell submitted to Castro a model of a hassock or ottoman, which by an unfolding process became a bed. A model offered by them a year earlier to Castro had been rejected. The 1952 model, which the trial court found embodied the invention covered by the Creveling patent, was accepted by Castro.
This model, embodying the Creveling patent principles, Castro submitted to Bebry for manufacture. Bebry, never having seen a folding ottoman bed before, expressed doubt as to its possibilities of success but for an order of 1,000 agreed to manufacture the Creveling ottoman exclusively for Castro. Bebry was informed that the Creveling patent application was pending. About a year later (approximately Fall, 1953), Bebry delivered the production model to Castro which accepted it and soon thereafter placed the ottomans on sale. Some 5,000 were sold by Bebry to Castro in the first full year of manufacture. In December, 1953, shortly after Castro’s acceptance of the production model, without Castro’s knowledge, Bebry filed a patent application for an ottoman bed. Bebry did not inform his patent attorney who prepared his patent application that he had the Creveling model in his possession. A patent was issued on this application on March 19, 1957.
In the meantime Macy, which had been handling a nonfolding ottoman bed without too much success, became aware of the Creveling ottomans advertised by Castro and tried to buy them from Bebry. Despite the agreement to sell exclusively to Castro, Bebry in January, 1955, commenced selling the ottomans to Macy. On Februaiy 8, 1955, these suits for patent infringement, injunction and accounting were brought against Bebry and Macy.
Briefly stated appellants rely upon three fundamental points, (1) the failure of the trial court to apply the proper legal determinants in the resolution of the infringement and validity issues (“the claims measure the invention”) ;1 (2) erroneous application of the principle of equivalence; and (3) invalidity because of prior art.
The facts as found by the trial court were supported by substantial evidence. The court not only heard and saw the witnesses including the experts but made a visual inspection of the ottoman beds and saw motion pictures and still pictures disclosing the methods of operation.
In arguing invalidity defendants rely heavily on prior disclosures shown in the Frank patent No. 1,945,186 issued in January, 1934, for a folding couch or davenport, and the Freedman patent No. 1,265,073 issued in May, 1918, for a bed structure for davenports. The trial court, however, found that these patents were not anticipatory and that there was no evidence that any of them had or could have functioned in actual operation. Significance also may be attached to the fact that there had been no successful commercial development of either the Freedman or Frank principles *308since 1918 and 1934, respectively. Yet when the Creveling-Castro ottoman was marketed in 1954, it achieved immediate commercial success. See Waring Products Corp. v. Landers, Frary & Clark, 2 Cir., 1959, 263 F.2d 160. In addition, from the testimony of a Bebry official came “persuasive evidence that the ottoman was not obvious even to those closely allied with the bed business” (181 F.Supp. 493, 495). Upon the entire record, the trial court was amply justified in concluding that the “Creveling patent is valid.”
With regard to the Creveling claims, there is great similarity to the Bebry structure except in the means by which the inner mattress frame is raised or lowered during the folding and unfolding operations. Appellant claims that there are basic structural and operational differences between the Creveling and Bebry mechanisms by which this operation is accomplished. The resolution of these technical and mechanical questions must, of necessity, be within the realm of expert testimony. The trial court found that the testimony of defendants’ expert was “unpersuasive” and that the testimony of other key witnesses for defendants on disputed issues of fact was unconvincing. Conversely, the trial court accepted as credible the testimony of plaintiff’s expert whom he characterized as highly skilled in the convertible bed furniture art and found that the crisscross legs used by Bebry, which Bebry urged constituted a different structure and principle of operation, were not new in the art; that they perform substantially the same function in substantially the same way to obtain the same result,2 and were equivalent to the single toggle lever of the Creveling patent; and that the use of such a mechanism would have been obvious to an ordinary mechanic in the art. These fact conclusions of the trial court were amply supported by the evidence and justify the conclusion of law that the Bebry ottomans infringed upon the Creveling patent.
The finding of equivalency of the Bebry means for raising and lowering the inner mattress frame to the Creveling mechanism also requires the conclusion that the Bebry patent is invalid for lack of invention over the earlier Creveling structure.
The counterclaims of Bebry were properly dismissed.
The judgment (decree, order for injunction and accounting) is affirmed.
. Milcor Steel Co. v. George A. Fuller Co., 1942, 316 U.S. 143, 62 S.Ct. 969, 86 L.Ed. 1332.
. Graver Tank & Mfg. Co., Inc. v. Linde Air Products Co., 339 U.S. 605, 608, 70 S.Ct. 854, 94 L.Ed. 1097.