Loud speaker cones for radio receiving sets

摘要

291,563. Naylor, C. H. April 4. 1927, Diaphragms, - A loud-speaker diaphragm of substantially conical shape and having a curved generating line is constructed of spirally arranged segments of thin material. In one method of constructing such a diaphragm, a number of strips of the form shown in Fig. 2 are wound spirally on a pattern turned to the desired inner shape of the diaphragm, the strips covering the whole surface of the pattern and being temporarily held in position by an adhesive substance, such as wax. A second layer of strips is then laid on the first having their spirals in the opposite direction, the two layers being gummed or glued together. When dry, the shaped diaphragm, shown in Fig. 3, is removed from the pattern. Fig. 4 shows a modified form of diaphragm produced by interlacing the two layers of strips, with or without a pattern. The finished diaphragm, which is preferably of exponential form is coated inside and out with shellac varnish &c. The Provisional Specification describes a diaphragm fixed at its edge of largest diameter and whose axial length is greater than one third of its base diameter.