2results about How to "Small stretch" patented technology

This invention relates to the field of hydraulic support installation technology in fully mechanized coal mining faces, specifically to a hydraulic support adjustment device for coal mines. The device includes a left upper sliding plate, a middle upper plate movably connected to one side wall of the left upper sliding plate, a right upper sliding plate movably connected to one side wall of the middle upper plate, and push-moving jacks installed on one side walls of the left and right upper sliding plates. A left lower base plate is installed on the lower surface of the left upper sliding plate, a middle lower base plate movably connected to one side wall of the left lower base plate, and a crossbeam movably connected to the upper surface of the middle upper plate. This invention uses the middle lower base plate, left lower base plate, and right lower base plate to form a lower base plate, and the middle upper plate, left upper sliding plate, and right upper sliding plate to form an upper sliding plate, creating a two-layer structure. To facilitate the transportation of non-removable parts, a U-shaped groove guide and guide slider are used to guide the middle upper plate during use, reducing the risk of displacement of the middle upper plate due to the extension and retraction of the push-moving jacks.

The utility model relates to the technical field of lift equipment, specifically relates to a telescopic extension ladder, including positioning portion and telescopic portion, positioning portion and telescopic portion sliding connection, to this to realize the height change of folding ladder, make it suitable for different operation scene, the positioning portion includes first ladder frame, and the sidewall of first ladder frame is provided with the guide slot, and the telescopic portion includes second ladder frame, and the inboard of second ladder frame is equipped with the guide convex edge of cooperation with guide slot, guide convex edge, and the outside is equipped with the guide pulley of first ladder frame adhesion, and the effect of guide pulley is: reduce the fit gap of the slide of two ladder frames when retracting, the maximum degree reduces the shaking of whole ladder, and the operation is safer, and when the second ladder frame retracts, the original sliding friction with first ladder frame changes the rolling friction with smaller friction coefficient, not only makes the extension ladder more convenient when retracting, but also can lighten the abrasion between two ladder frames when the extension ladder retracts and slides to the maximum, prolongs the service life of telescopic ladder.