Abstract: An image display system includes a server having a first image database that stores a first image having a first file format for movable image display; a second image database that stores a second image having the same display contents as the first image and a second file format for static image display; and an image distributor for distributing, in response to an image display request from a user terminal, the first and second images corresponding to the request. The user terminal has a movable image display unit for movably displaying the first image from the server; a static image display unit for statically displaying the second image; and a switch for switching the movable image display unit and the static image display unit.

Abstract: A ring installation method and a ring installation jig which are capable of performing an installation operation with high efficiency in which an anti-slip-off ring made of an elastic metal material is uniformly expanded to be fitted on a pin's end and pushed to an engagement position to be mounted thereon. The jig has (i) an expansion guide member which has, at its front, a working face to be brought into contact with an end of a chain-coupling pin for positioning and has a ring expansion guide section on its outer periphery and to which a propulsive force is applied; (ii) an expansion claw fitted on the expansion guide member for expanding and supporting the anti-slip-off ring and moving it to the pin's end; (iii) an elastic body for applying a pressing force to the expansion claw; and (iv) a pusher for pushing the anti-slip-off ring which has been expanded by the expansion claw into an annular space defined by a link of the chain and the pin.

Abstract: A crawler-type vehicle undercarriage including a track frame, an idler, a sprocket, a crawler encompassing the idler, track rollers, and the sprocket and the idler, the sprocket and the track frame located to line up in a straight line comprising the crawler-type vehicle undercarriage comprising (i) an idler avoided from pivoting upwardly or downwardly relative to the track frame, (ii) a first arm pivotally mounted at the bottom of the track frame, and (iii) a second arm pivotally connected to end portion of the first arm. The track roller unit adjacent the sprocket is preferably pivoted about a pivot center of the first arm positioned at the bottom of the track frame and toward the idler relative to a pivot center of the second arm. The track roller travel improves a flexibility of the track roller to the crawler, and work in a high tractive force is carried out with the track rollers providing unchangeable real contact areas to the ground.