The Locke high tension insulators

[Trade Journal]

Publication: The Electrical Engineer

New York, NY, United States
vol. XXIV, no. 494, p. 398, col. 1-2



In a patent issued to Mr. Fred M. Locke, of Victor, N. Y., the inventor describes a method of constructing insulators, possessing special, high insulating properties.

Insulators heretofore have been constructed higher than they are broad, but Mr. Locke has found that these insulators have been defective owing to their short diameter and spread. He has, therefore, found in actual practice, that it is necessary to increase the spread with respect to the height, and this for two reasons: First, the increase of its efficiency as an insulator, and, second, that it allows of the use of a shorter, and therefore a stronger, insulating pin, which is particularly desirable in high-voltage power transmission.


Locke's High Tension Insulators.


Mr. Locke has observed that in the ordinary insulators, as above described, the edge comes so close to the supporting pin or the support upon which it is mounted that the current arcs from the edges of the insulator to the pin or support upon which it is mounted. To obviate this difficulty he has constructed an insulator as broad or broader than it is high and provided it with one or more skirts or petticoats, as shown in the accompanying illustrations.

In one of the forms illustrated Mr. Locke also provides the insulator with a bead or trough upon its periphery to conduct the water to certain points, so that the dripping will take place at points remote from the support upon which the pin is mounted. He is thereby enabled to prevent the water from accumulating upon the entire lower edge of the outer skirt, which would otherwise form a conductor for the current, which, when it had passed around the point nearest the support, would otherwise arc across.

Insulators of this "helmet" type are employed on the Niagara transmission to Buffalo and on the Lachine transmission to Montreal.


Keywords:Power Transmission : Niagara : Imperial Porcelain Works : Fred Locke : U-925 : U-937
Researcher notes:Note that U-937 (left) was used on the Niagara-Buffalo line as well as the Lachine line to Montreal. The insulator on the right is U-925.
Supplemental information: 
Researcher:Elton Gish
Date completed:May 22, 2005 by: Elton Gish;