Abstract: A writing board structure includes a frame, a writing tablet of glass, and a background piece corresponding in size and shape to the writing tablet. The writing tablet and the background piece are held together in the frame such that a rear surface of the writing tablet comes in contact with a front surface of the background piece. The front surface of the background piece is provided with a white coating which is intended to furnish a front surface of the writing tablet with a white background. The front surface of the writing tablet is used for writing or drawing erasably with a pen, chalk, or the like.

Abstract: A foldable frame comprises a folding structure to enable a plurality of horizontal support rods of the framework to be folded and unfolded. As the horizontal support rods are folded, a plurality of upright support rods of the framework are drawn together. The folding structure comprises two movable joints and a connection rod. The movable joints are located at the midpoints of the horizontal support rods. The connection rod is pivotally fastened between the midpoints of two horizontal support rods.

Abstract: A rack includes a horizontal framework for holding or displaying various things. The horizontal framework can be adjusted in height by a plurality of expandable units by which the horizontal framework is mounted on a base. The expandable units are formed of an outer tube, and an inner tube slidably fitted into the outer tube in conjunction with a locating structure having a cylindrical seat, a sleeve, and an elastic lock ring. The lock ring is retained in one end of the sleeve which is rotatably fastened to the cylindrical seat. The bottom end of the inner tube is slidably fitted into the top end of the outer tube and is embraced by the lock ring which is made compact to embrace tightly the bottom end of the inner tube when the sleeve is turned clockwise. The lock ring is relieved of the pressure when the sleeve is turned counterclockwise.

Abstract: A barbecue grill includes a base on which a first expandable unit and a second expandable unit are uprightly mounted such that the first expandable unit is fastened to two first cross bars of a stand, and such that the second expandable unit is fastened to two second cross bars which are rested on the first cross bars. A charcoal holder is supported by the first cross bars. A cooking grid or plate is supported by the second cross bars. As the stand is adjusted in height by the first expandable unit, the charcoal holder and the cooking grid are simultaneously raised or lowered. As the second expandable unit is adjusted, the second cross bars are caused to move away from or toward the first cross bars, thereby resulting in an adjustment in distance between the cooking grid and the charcoal holder.

Abstract: A leakproof fountain pen with a ballbearing tip includes an upper casing threadedly engaged to an ink flow guide. An ink reservoir has an open end received by an annular base of the ink flow guide. The upper casing combines with the ink flow guide to form a chamber for collecting ink which may flow from the ink reservoir. The ink flow guide further comprises an axial vent hole communicated with the atmosphere; an axial ink hole to serve as a path for ink flowing to and from the chamber and the ink reservoir; and an axial control hole having a flow portion with a bigger diameter. A gravity post is movably disposed inside the flow portion and can block the passage of ink between the ink reservoir and the control hole. A plug unit acts as a support for the gravity post. A first end of the ink flow guide is substantially V-shaped with the lowest point at the opening of the ink hole to direct the collected ink from the chamber towards the ink hole when the pen is held upright.

Abstract: An ink which consists of 17-20% by weight of a graphite powder, 17-20% by weight of a lubricating oil having a low viscosity and a low melting point, 44-47% by weight of oleic acid extracted from vegetable oil, 15-17% by weight of ethylene glycol, and 450-500 ppm of ferrous sulfate, the oleic acid and the ethylene glycol reacting with one another and serving as a carrier, and the ferrous sulfate catalyzing the reaction between the oleic acid and the ethylene glycol.