Roller clutches include a cage and a plurality of energizing springs, one for each of a plurality of rollers, The springs may be retained just by the force of their own compression between a pocket and roller. More often, however, the springs are mechanically latched to the cage, so that they and the cage form a subassembly. There are several known means of latching the springs to the cage. A common type of cage has a series of vertical cross bars and adjacent cross bars, or equivalent structure, arranged in pairs so as to form radially opening slots. A commonly used energizing spring is the accordion type with a series of oppositely opening V shaped folds. When this type of cage and spring are used together, the spring is generally mounted by press fitting the next to last fold over the vertical cross bar, which simultaneously pushes the last fold into the slot. A latch structure of some type then clicks into place over or under a surface of one of the cross bars at the spring is pushed home to keep the next to last fold in place. An example of one possible latch structure is disclosed in U.S. Pat. No. 3,902,580 to Johnson, assigned to the assignee of the current invention. There, a spring finger bent out of a side of the mounting fold clicks under an edge of the vertical cross bar. Another possible approach is disclosed in U.S. Pat. No. 4,187,937 to Kitchin, also assigned to the assignee of the current invention. There, a short tab bent out of the tail of the last spring fold clicks under the horizontal cross bar as the next to last spring fold is predded onto the vertical cross bar.
While the last latch structure is rigid, it is somewhat difficult to assemble. During the spring attachment process, care must be taken to assure that the short latching tab ends up right under the inner surface of the horizontal cross bar, or very close to it, so that it can click solidly into place. The stroke with which the spring mounting fold is pushed into place must therefore be fairly closely controlled and monitored, and the tolerance "window" is not large. While this can be and has been done, tight tolerance assembly processes are inevitably more difficult and expensive. The latching structure disclosed in U.S. Pat. No. 4,782,928, also assigned to the assignee of the current invention, provides an improved latch for the same type of cage and spring that has a greater assembly tolerance window. A downwardly extending resilient flange and an upwardly extending resilient finger grasp the horizontal cross bar directly between them to provide a positive latch. The resilience of the flange and finger provide an increased zone of stability, and the attachment stroke need not be as closely monitored. The particular cage to which this spring is attached, however, happens to have sufficient room outside of the outer surface of the horizontal cross bar for the downwardly bent flange to work. That will not be the case for all cages of that general type. In some cages, the outer surface of the horizontal cross bar is so close to the periphery of the cage that there is no significant room available there for any latching structure to work.