Specifications and drawings of patents relating to electricity issued by the U. S. Volume 57 - Tapa blanda

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1888 Excerpt: ... telephonic receiver. Fig. 2 is a 7c separate elevation and side view of the armature and support. Fig. 3 is a detached edge view and side view section of the bird's-eyemaple tympan with holes in it. Fig. 4 is an end view of the instrument. Fig. 5 is an edge 7s view, and Fig. 6 is a side view, of the armature-support in the form of a cross. A represents the core of the magnet, which core may be permanently magnetized, and B denotes the helix or coils of the same. 80 In order to intensify the action of one end of the magnet, tfie mass of soft irou C is attached to the other pole thereof. Opposite the other pole thereof is the armature D, in the form of a short thick piece of iron, as aforesaid, that 85 is fastened to the elastic support E, which is made as before stated, and sustains the armature in proximity to the pole of the magnet; but the support is free to move as the armature is vibrated by the variations in the mag-90 netism. At the other side of the armaturesupport E there is a projection, F,that rests against the tympan G. This tympan will operate with the other parts, heretofore named, when made of any suitable material; but I find 95 that a veneer of bird's-eye maple is the best, becanse it has no tone of its owu when vibrating, in consequence of the knotty nature of the wood. The edges of the tympan G are clamped be-io0 tween the rings H I so as to be properly held, and one of these rings is formed upon or con nccted with the handle portion of the instrument, that is composed of a case surrounding the electro-magnet. In the casing below the ring H several openings, O, are made, so that 5 the air is not confined upon either side of the tympan. One way of making such openings is to form the upper part of the case with lugs or arms, the spaces betw...