Pushing to the final frontiers of railroad model detailing, ACCURAIL has developed the first HO scale magnetic coupler that is a correctly scaled and proportioned representation of the prototype. Previous offerings in this field have suffered from poor appearance due to incorrect proportions; the width and length of the coupler are more than one third oversize, while the height is actually undersize, in an attempt to reduce the overall bulk of the coupler. Because of the increase in length, model cars coupled in a train have more than the correct amount of space between cars. In addition, the standard mounting box that has been in use for these couplers for over forty years is wider than a correctly scaled replica of the car center sill, making the detailing of this important area of the model impossible.The PROTO HO ACCUMATE is correctly sized, and is shaped to model the appearance of the actual AAR type E coupler. The length of the coupler, when mounted in its own draft gear box, is designed to provide the scale striker to coupler pulling face distance. The draft gear box itself is detailed to represent the prototype sills, draft lugs, and coupler yoke. This box is long enough to extend all the way to the body bolster on a model of a typical car, but can be cut shorter if need be. In this shortened form, the PROTO HO ACCUMATE is adaptable to HOn3.Although the PROTO HO ACCUMATE features a reduced profile, this profile is designed to mate with the standard couplers used in HO scale. While the width of the coupler shank has been decreased to fit the narrow draft gear, a corresponding increase has been made in the depth of each half-shank, so the resulting shanks have 95% of the cross section, and therefore strength, of the standard ACCUMATE
The ACCUMATE consists of two shank pieces that pivot around a common post, herein referred to as the hook, which carries the knuckle profile, and the blade. When coupled, the hooks are sprung into engagement, much like the common horn-hook style coupler, the blades provide the buffing, or pushing, surface. An interlock between the hook and blade limit their motion relative to one another, and provide for a stable surface to be pushed against.The integrally molded springs are sized to bias the hook toward the coupled position, and are located within the coupler box where there is enough room for springs designed to operate at a low level of strain, as in the familiar horn-hook. A stop molded onto the blade prevents the hooks from springing past the gathering range of the knuckle profile.A mild steel pin is mounted to the underside of the hook so that a magnet mounted in the track can draw it aside to effect uncoupling. In addition, the inside of the knuckle profile is shaped generally circular, so that a specially shaped tool, the SWITCHMAN can be inserted and rotated to easily spring the couplers apart without jamming or snagging as is the case with existing pivoted knuckle designs.Note that the knuckle profile has NO draft angle. This is important because this feature significantly increases the number of cars that can be pulled in a train, as the draft angle in operation becomes a camming angle that tends to lift one coupler over and out of its mate. See the recent MicroTrains advertising in the Hobby press for a discussion of this topic and their solution to it.