Abstract: The present disclosure provides polyester elastomers, polyester elastomer compositions, and methods of preparing polyester elastomers and polyester elastomer compositions. The polyester elastomers in the present disclosure are prepared by reacting at least one di-carboxylic acid or tri-carboxylic acid, at least one mono-carboxylic acid, and at least one polyol. The crosslinked polyester elastomers can be formulated into various personal care formulations.

Abstract: A dust cover comprises a plurality of shied plates which are equal in shape and progressively reduced in size. The shield plates are joined together such that they expand and retract along an axial direction; a linking device formed of a plurality of link rod units which have two rod members equal in length. The two rod members are pivoted together at the midpoint such that two ends of the two rod members form a pair of opening-closing arms. Two arms of each one end of each link rod unit are pivoted with two arms of other link rod unit to form two pivoting points pivoted in the lower side of the same shield plate.

Abstract: A dust cover comprises a plurality of shied plates which are equal in shape and progressively reduced in size. The shield plates are joined together such that they expand and retract along an axial direction; a linking device formed of a plurality of link rod units which have two rod members equal in length. The two rod members are pivoted together at the midpoint such that two ends of the two rod members form a pair of opening-closing arms. Two arms of each one end of each link rod unit are pivoted with two arms of other link rod unit to form two pivoting points pivoted in the lower side of the same shield plate.

Abstract: This invention is a dust-proof protection cover with connecting rods. It includes several protecting cover boards in the same shape with different sizes. The sizes of protecting cover boards are decreasing and their connection will form a structure that can expand and contract along the same axis. On the bottom board of each protecting cover board, there is a sliding trough. In addition, there is a linking device is made of many connection shafts. All these connection shafts will form a device with serial protection cover that can expand and contract.

Abstract: This invention is a dust-proof protection cover with connecting rods. It includes several protecting cover boards in the same shape with different sizes so that they are slidably engaged to each other. The sizes of protecting cover boards are decreasing and their connection will form a structure that can expand and contract along the same axis. On the bottom board of each protecting cover board, there is a sliding trough. In addition, there is a linking device is made of many connection shafts. All these connection shafts will form a device with serial protection cover that can expand and contract.