The court finds the three claims of the Beckwith patent in suit valid. The field undoubtedly is narrow, and the elements old, but they seem to have been brought together, through the application of definite mechanical skill, into such combination that they act substantially as one organization effecting a distinct improvement.

The defendants’ structure infringes. Nathan v. Howard, 143 Fed. 889, 75 C. C. A. 97; Vrooman v. Penhollow, 179 Fed. 297, 102 C. C. A. 484.