Abstract: A window opening and closing assembly capable of controlling an opening angle of the window effectively is disclosed. The assembly comprises a base with a groove along a longitudinal direction thereof, a slider inserted in the groove, an arm rotatably mounted on the base, a handle rotatably placed at a portion of the base and having a worm gear at an end thereof, a worm wheel meshing with the worm gear, and a switch for controlling the location of the slider. Wherein the slider has an angled side inwardly angled at a side of the first sliding portion thereof and the arm has a straight side for restricting a rotation angle thereof. Thus, an opening angle of a window can be controlled by an operation of the straight side and angled side.

Abstract: A concrete pile construction method and an apparatus used for improving soft earth ground by constructing reinforced bar concrete pile structures in the earth. The purpose of the present invention is to provide a process for securing firm concrete piles having a reinforced bar core with uniform concrete by a pile apparatus in which projections are radially formed and a conical-shaped bit is formed pointedly on the pile apparatus.

Abstract: The present invention relates to a concrete pile construction method and an apparatus used for improving soft earth ground by constructing reinforced bar concrete pile structures in the earth. The purpose of the present invention is to provide a process for securing firm concrete piles having a reinforced bar core with uniform concrete by means of a pile apparatus in which projections are radially formed and a conical-shaped bit is formed pointedly on said pile apparatus.

Abstract: A window opening and closing assembly capable of controlling an opening angle of the window effectively is disclosed. The assembly comprises a base with a groove along a longitudinal direction thereof, a slider inserted in the groove, an arm rotatably mounted on the base, a handle rotatably placed at a portion of the base and having a worm gear at an end thereof, a worm wheel meshing with the worm gear, and a switch for controlling the location of the slider. Wherein the slider has an angled side inwardly angled at a side of the first sliding portion thereof and the arm has a straight side for restricting a rotation angle thereof. Thus, an opening angle of a window can be controlled by an operation of the straight side and angled side.