When this patent was before us, less than two years ago, we thought that Woerheide had added a simple but decidedly efficacious improvement to the roofing art. Prior to his invention the problem of fastening prepared roofing to the roof was in a most unsatisfactory condition. The devices then used, large-headed nails, round metal caps, nails and cement, proved wholly insufficient. None of them solved the problem. The roofing material was torn, a tight joint was not produced and the roofs continued to leak. Unless *904some remedy for these radical defects was found the prepared roof industry could not be successfully continued. We have, then, a valid patent for a simple but useful device which successfully solved the problem in a highly useful art. The claims in issue are entitled to a liberal construction and the sole question here is, are they infringed? When the case was here before it was stated in the appellant’s brief as follows:
“It is undoubtedly the fact that plaintiff’s cleat is the first sheet metal roofing cleat commercially introduced in this country for the purpose of securing prepared roofing.”
The advantages of this cleat over the tin caps and large-headed nails in use at the date of Woerheide’s invention, are manifest. The cleat prevented gaps and buckling which occurred when the large-headed nails and similar devices were used. There were no intervals in the pressure of the cleats, it was continuous. The nearest approach to this continuous pressure found in the prior art is the wooden strips, but such strips will bend, crack, split and decay. They can never have che-endurance and the inflexibility necessary for a roofing cleat. The problem of producing a suitable holder for prepared roofing was not as simple as it now appears, after the result is accomplished. Wood could not be utilized for the reasons just stated. Sheet metal could not be made effective; it would not hold the roofing rigidly between the nailing domes. It may be that if -we search this and analogous arts we may find every separate element of Woerheide’s invention but we are convinced that never before Woerheide were they combined in a cleat for holding prepared roofing material upon a roof so as to prevent buckling and leaking.
The defendant has shown considerable ingenuity in its effort to avoid infringement. To a casual observer the patented device seems quite different from the defendant’s device. It will be seen, however, upon closer examination that the defendant has all the valuable features of the patented structure, although to the ordinary observer they look very different.
The cleat, arched transversely and having greater length than breadth, the narrow crown, the abrupt side walls leading from crown to base, tire ends of the cleat, being closed by strengthening stay portions, drawn from the crown to the base and connecting the side walls to resist outward movement thereof, all are present in both of defendant’s structures.
The decree is affirmed with costs.
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