Abstract: A cross-shaped beam laser ray device having a housing containing a battery, a laser diode driver circuit, a laser diode, and a convex lens. A transverse columnar faceted lens, respectively, with a cap having an aperture through its center is fastened to the front extremity of the housing. The transverse columnar faceted lens is aligned vertically with the laser rays such that afer laser rays are emitted by the laser diode and converged through the convex tens, the transverse columnar faceted lens refracts them into a cross-shaped beam that is projected through the aperture and appears as cross hairs when directed onto the surface of a targeted object.

Abstract: A cross-shaped beam laser ray device comprised of a housing containing a battery, a laser diode driver circuit, a laser diode, and a convex lens, and a transverse columnar faceted lens, respectively, with a cap having a aperture through its center fastened to the front extremity of the housing. The transverse columnar faceted lens is aligned vertically to the laser rays such that after laser rays are emitted by the laser diode and converged through the convex lens, the transverse columnar faceted lens refracts them into a cross-shaped beam. that is projected through the aperture and appears as cross hairs when directed onto the surface of a targeted object.

Abstract: A method of synchronized survey with computer aid with which a working drawing of engineering is transformed into a drawing file in the computer. The drawing file on the screen accompanying with the window page can appear locations and coordinates of a reference point, a rear view point or all control points specifically. The computer and the theodolite connect with a modem respectively to transmit data related to survey to each other by way of communication network. Place the theodolite at the reference point in the job site and the locating prism at the rear view point or each control point. The screen of display in the computer may appear the location of locating prism in the working drawing on the instant such that the operator of locating prism may be informed to move toward a correct operating point.

Abstract: An easily-combinable and movable speaker case includes two side boards, a front holed board, a speaker support board, an electric circuit board, a rear control board, a cap board, a bottom board, and a pull member. The two side boards are spaced apart parallel and respectively has a plurality of vertical position grooves and posts spaced apart on an inner surface for inserting the front holes board, the speaker support board, the electric circuit board and the control board in the position grooves of the two side board. Then the cap board and the bottom board are respectively fixed on and under the two side boards with screws. Further two rollers are fixed under the bottom board to permit the speaker case inclinedly move on the ground by pulling the pull member.

Abstract: A three-dimensional laser levelling and angle-calibrating instrument includes: a stand; a magnetically-attractive laser level having a horizontal bottom attractable on the stand, a vertical wall perpendicular to the horizontal bottom and a first laser illuminator mounted on the laser level for projecting a horizontal laser ray for levelling purpose; and a magnetically-attractive laser angle calibrator having a second laser illuminator and attracted on the vertical wall of the laser level for projecting a vertical laser light line for checking a verticality.