This suit is brought on letters patent No. 67,046, granted to Joseph L. Hall, the appellant, July 23, 1867, for an 'improvement in connecting doors and casings of safes.' The only claim alleged to have been infringed is claim 3, which is in these words:
'(3) The concial or tapering arbors, 1, in combination with two or more plates of metal, in the doors and casings of safes and other secure receptacles, the arbors being secured in place in the plates by keys, 2, or in other substantial manner.'
In regard to what is embraced in this claim the specification says:
'The nature of this invention consists in * * * securing a series of plates forming a casing or door of the safe by means of conical or tapering arbors, which, being tapped in from the outside of the door or casing, and keyed upon the inside, present serious obstacles to the removal of successive plates forming the body of the safe. Figure 1 represents a perspective view of a safe embodying my invention. Figure 2 is a horizontal section of part of the same. Figure 3 is a detail view, in cross-section, of the door of the safe, showing the shape of, and manner of securing, an arbor. The most approved manner of securing together the numerous plates forming the casings and doors of safes is by means of screws tapped in from one series of pairs or triplets of plates from the inside presenting no rivet heads upon the outside surface of the safes. * * * In the doors of safes the outer plate, D, is secured to the plate, E, F, by screws, b, countersunk in the plate, F. * * * The fourth plate, I, has about the same area as the plate, E. It is secured to the plate, F, by screws, e, which pass through the inner plate, K, in which they are countersunk. * * * In order to still further secure together the plates forming the door of the safe, I use a conical arbor, 1, or a number, if necessary; they are introduced in openings through the series of plates, being tapped into the two innermost of all the plates, and keyed in position. A smooth surface in the plane of the outer face of the door is presented, giving no means of removing the arbors, I, even should the key, 2, be removed. * * * Since the doors of safes are more exposed than any other part of them, it is necessary to embody in their construction such devices, which in themselves are the simplest, as shall effectually bar forcible entrance to the safes. The introduction of arbors for the purpose of more effectually binding in one compact mass the series of alternate iron and steel plates in the doors or bodies of safes will very much protract the labors of the burglar; indeed, it will be necessary, in order to remove one sheet in succession, to cut out the arbors, which are made of the hardest steel. The arbors may be tapped through the entire series of plates, and the inner end rivet-headed instead of keyed, as shown in the drawing, or the inner plate, as well as other in the series of plates, may be put together in sections, and, fitting into notches in the arboror arbors, secure them in position. In this latter construction the arbors need not be conical, but may have any cross-section, tapering longitudinally.'