A planetary reduction gear comprising pairs of partial planetary gears, two partial internal gears and a sun gear or comprising pairs of partial planetary gears, two partial sun gears and an internal gear in which partial planetary gears mesh with partial internal gears or with partial sun gears independently. One of the partial gears is fixed to the input shaft or to the casing. The other partial gear is loosely connected to the input shaft or to the casing by a spiral coupling which allows the...

This invention provides a bearing retainer for a sliding mechanism for use in a machine tool, especially a press. The bearing retainer has a tubular or generally cylindrical retainer body. The retainer body has a plurality of supporting holes to support rollers. Tongue-like portions are formed at the edge portions of each supporting hole for preventing a roller from falling out of the supporting hole. Cavities are provided between the adjacent supporting holes. Each cavity permits the edge porti...

A shutter includes a shutter panel 10 having a plurality of plates 1 which are rotatably connected to one another by hinge members 2, and a pair of guide rails 4 formed with guide grooves 40 which slidably hold opposite end edges of the shutter panel 10. By using the hinge members 2 which connect the adjacent plates 1 to each other so that the plates are rotatably bent only in a direction in which a curvature becomes greater than a portion of the guide groove 40 having a minimum curvature, it is...

In a fastening tool in which fastening members may be inclined as they are threadedly inserted together whereby almost no displacement load is applied to the members, a member having a bolt through hole with a tapered seat surface, and a fastening bolt that includes a bolt body provided about its outer periphery with a male thread, and a head provided on an end of the bolt body that has a diameter greater than that of the bolt body, in which the head has a lower outwardly curved tapered surface ...

A shutter has a shutter panel and a pair of guide rails that hold both end portions of the shutter panel slidably. The guide rails have curved portions. Each of the guide rails includes straight members having parallel tie plates and an interval plate connecting central portions of the tie plates resulting in an H-shaped section. Each of the guide rails includes corner members having curved plates succeeding to the tie plates. Both end portions of the shutter panel are inserted slidably between ...

A guide device includes a shaft member and a column. The column has a through hole formed therein and the shaft member penetrates the through hole of the column. A plurality of pockets are formed on an inner circumferential surface of the through hole of the column. The pockets are disposed on a plurality of cross sectional planes that are perpendicular to an axial direction of the column. In each pocket, there are provided an outer race or roller rolling axially on an outer circumferential surf...

A needle roller bearing includes a plurality of needle rollers that each have first and second end portions and that are disposed circumferentially around a shaft, a cylindrical first retainer member having a plurality of first notches each respectively adapted to rotatably support the first end portion of a respective one of the rollers, and a cylindrical second retainer member located spaced apart from and opposite the first retainer member and having a plurality of second notches each respect...

A guide apparatus (1) slidably supports a shaft member (2) and a column (3) relative to each other. The column (3) has a through hole (3a) formed therein and the shaft member (2) penetrates the through hole (3a). In the column (3), there is provided a slide mechanism (5) formed of a plurality of cylindrical rolling elements (50) adapted to roll axially on an outer circumference (2a) of the shaft member (2). The column (3) is formed of a plurality of split members (31, 32, 33, 34) that are divide...

A shutter panel (10) in which respective longer sides of slats (12) made of synthetic resin are connected through hinge mechanisms to be freely bendable manner, wherein the hinge mechanisms include one hinge member and another hinge member. Each hinge member has a connecting groove that is opened outwardly. By fitting and coupling the longer sides of the slats into the connecting grooves respectively, smooth opening and closing of the shutter panel (10) can be performed because of decreasing war...