Can anybody give me some information on this type of coil? Front and back have no sliding panels, just flat pieces held on with small brads. All 3 have brass tops on them. Is this an early type coil or an after market type coil. Thanks,
From Bruce's Black Book:
FORD COIL EVOLUTION
K-W became the major supplier in 1913. The early K-W coil was 5-3/8 x 3-1/4 x 2-1/4” with the location of the contacts lower on the side, and the bottom located near the rear of the box. The top was a flat sheet of brass held to be box with six round-head brass screws. These coils used the standard vibrator components.
Sometime in early calendar 1913 the box was redesigned to the standard (5 x 3-1/2 x 2-1/8”) size with the contacts in the standard location. These coils were made by K-W and Ford. The two sides were flat pieces of wood, glued on one side, and nailed with ten brads on the other. The brass top was held with six screws. The hardware on the top was all brass.
The location of the nails used to hold the cover to the box was rearranged, changing the number required from ten to eight.
Removed two center holes for the vibrator base (the brass top) screws., changing the number required from six to four.
Removed notes specifying the stationary side of the box to be glued in place, and the cover to be held in place with eight nails. Also specified the stationary side of the box to be tongue and grooved in place; the cover to be tongue and grooved on one end and two sides and to be secured with two nails at the lower end. The nails carried the factory number of T6744.
Removed “experimental” note from Machine and Die Casting Drawings for the composition coil unit boxes.
Design changes in the composition boxes. (The factory drawings are incomplete and do not indicate the nature of the changes.) Note: both wood and composition boxes were in production at the same time.
Wooden design. Removed holes for vibrator base screws and connecting wires from the top. Called for holes in the top for the vibrator and adjusting bolt, and four holes for vibrator bolts, short and long. The brass top is no longer used. The vibrator parts are now mounted directly on the black-painted top wood. The various screws and nuts are now steel.
Discontinued the composition coil boxes.
The name “Ford” is now burned in to the side of the box. The design of the vibrator is changed, eliminating the “grub” screw in the mounting bracket. The vibrator spring contact is still held with two screws.
The construction of the wood box is simplified. The tongue-and-groves are now larger (fewer in number).
Specified the name “Ford” in script to be placed on the edge of the piece that forms the top of the box; letters to be rolled in.
T6793A2 adopted as the new factory number, Ford design coils. T6793A1 (the older design) was designated for “outside design.” Note: the drawings survive. There is no detectable difference in the two types.
The vibrator components are again revised; the vibrator spring is now riveted to the mounting base.
Look up Joseph A. William's Patent No. 1,092,417 for an Ignition Apparatus for more information on that coil.
The patent was filed March 5, 1913 and granted April 7, 1914.
Williams became the W of the KW Coil Company.