Linear motion guide unit with end recessed retainer

DETAILED DESCRIPTION In accordance with the present invention, there is provided an improved retainer for use in a linear motion guide unit.
Typically, a linear motion guide unit includes an elongated rail, a slider, a plurality of rolling members interposed between the rail and the slider and a retainer for retaining the rolling members in position.
The present invention is concerned with such a retainer for use in a linear motion guide unit, and, in particular, with a novel structure of such a retainer.
In accordance with a preferred embodiment of the present invention, there is provided a retainer which is generally elongated in shape and having a shape which allows to be located in a gap between the rail and the slider for retaining the rolling members in position.
The slider or the rail is provided with a pair of stoppers for limiting the movement of the retainer in the longitudinal direction so as to prevent the retainer from slipping away from the present unit.
The retainer is formed with a recessed portion at each end therefor for receiving therein a corresponding one of the stoppers at least partly when the retainer is located at its corresponding limit location so as to increase an effective stroke of the retainer relative to the slider or rail.
In another embodiment of the present invention, a retainer has a horizontal section and a pair of vertical sections extending vertically from the opposite sides of the horizontal section, thereby defining a generally U-shaped cross section.
The horizontal section of the retainer is formed with a recessed portion at each end thereof.
As a further modification, the horizontal section of the retainer is formed with at least one window.
Preferably, the shape of each of the recessed portions of the retainer is identical to that of a part of the window.
In this case, an elongated stock member having a generally U-shaped cross section and formed with a plurality of windows of a predetermined shape, same or different in size, spaced apart and arranged along the longitudinal axis is prepared and such a stock member is cut transversely to provide a retainer having a desired length and having a structure of the present invention