| On 5-Knuckle hinges, the knuckles on the 2er leaf carry the lateral load where they contact the hinge pin. The pin is fixed (or tight) in the 3er leaf and the 2er leaf rotates around it. The greatest force exerted on hinges by the door is the vertical load. This load is carried by the joint(s) between the knuckles. When bearings are used, they are expected to ease the job of carrying that load. In order for the bearing to perform that function, the dimensions that the knuckles are manufactured to are controlled so that the joint that has the bearing carries the load. All other joints have a small amount of clearance so that they do not contact each other, thereby allowing the bearing to do its job without added friction from other joints. The specific joint where the bearing is located is not relevant to its ability to carry the weight of the door. At one time, all of the major hinge manufacturers made their 5-Knuckle standard weight hinges with the bearings located “inboard” Some of the manufacturers use a mounting method for their bearings which was difficult to machine for and to assemble in the “inboard” position. When they realized that it would be easier for them to do this work at the “outboard” position, they changed to that location, purely for the ease of manufacturing. McKinney did not choose to follow that path, just because the others did. Our methods of manufacture did not require it and the expense in machinery and tooling changeovers would have been cost prohibitive |
