HYDRAULIC DRAFT GEAR FOR ELEVATOR

PROBLEM TO BE SOLVED: To provide a hydraulic gear for an elevator capable of reducing an overall height. SOLUTION: This hydraulic draft gear for an elevator comprises a cylinder 2 standing in a pit 1 of a hoistway and filled with working oil O inside, and a plurality of plungers 3-5 shrinkably fitted with the cylinder 2 in an upward and downward direction, formed with sequentially smaller diameters, and concentrically overlaid on each other. The hydraulic draft gear is provided with an orifice hole 9, in which the working oil O circulates according to a downward movement of the plungers 3-5, an elongated conical member 11, whose tip is freely inserted in the orifice hole 9, and a return spring 7 returned to an initial position after the plungers 3-5 move downward, in the cylinder 2. The return spring 7 comprises a first spring 7a and a second spring 7b split into two in the upward and downward direction, and a disc 10 having the elongated conical member 11 is interposed between the first spring 7a and the second spring 7b displaceably upward and downward. COPYRIGHT: (C)2010,JPO&INPIT