Slater Lewis screw-top patent

LEWIS'S PATENT SELF-BINDING

INSULATOR.

THE object of this invention, which is shown by the figure, is to dispense with the usual binding wire. The binding is effected by hooking on the line an iron clip of horseshoe shape, and then inserting the coarse conical screw, which is cut on the end of the insulator, between the said clip and line-wire. On giving the insulator a turn and a quarter it becomes rigidly fixed in its position, and all chafing and friction is entirely overcome and cut or broken wires are prevented from "running back." If, in some districts, it is considered desirable, the clip may be dispensed with and the binding effected with No. 8 wire. It may also be soldered fast to the line, and yet, notwithstanding this, the insulator may be detached and re-attached instantly without in any way disturbing the binder. The porcelain is kept clean and free from the usual coating of rust, not only by reason of the iron clip which encircles the insulator being galvanised after it is bent to shape, but in consequence of the total absence of friction and "working" of the wires.

Owing to the fact that the clip for gripping the wire touches the insulator at but three points only, it seems probable that a line fitted with the new invention would test better than in the case where the ordinary binding wire, which closely encircles the porcelain, is used. Mr. Lewis's binder is the best we have yet seen, and the advantages which it possesses are so obvious that they need not be enumerated. The general principle of the idea is certainly highly ingenious, and of its efficiency there can be, we think, no doubt. The important item of cost, however, must not be overlooked, and when we consider that the present system of binding costs but £d. per insulator, and that, although not perfect, it cannot be said to be inefficient, it is clear that the margin of profit which could be made from any substitute would be very small. It must not be forgotten, however, that cost is not the only point to be considered.