DE2655135A1 - Extended action lift arm ram assembly - has interconnected cylinders adjacent to each other with pistons extending in opposite directions - Google Patents

Abstract

The hydraulic or pneumatic assembly is for lifts and hoists etc. having two cylinders alongside each other and inter-connected. One piston extends to one side and the other towards the other, and the working faces of the pistons are of the same size, so that they extend simultaneously. Alternatively there can be three rams, one piston having a working face of area equal to the sum of those of the other two, which extend in the opposite direction from it, or four rams, two pistons extending to each side. Compared with existing designs the invention gives double the height of lift without increasing the space required by the ram.

Description

Hydraulic or pneumatic cylinders

for elevators and hoists.

Hydraulic elevators or hoists are operated by cylinders with pistons (ofAx piston) driven. The stroke of the piston must normally match the stroke of the elevator or lifting equipment. With high delivery heights it is often difficult to open the cylinder to be placed under the elevator car in the floor. Likewise is the funding height of the elevator is limited if the cylinder is located next to the car in the shaft will. As alternative solutions are known: The use of telescopic cylinders and also the use of cylinders in connection with ropes or chains. In the latter Trap, the stroke of the cylinder is multiplied by the use of pulleys. These facilities are complex and expensive. In the first case a synchronous telescopic cylinder must be used be used to achieve good driving characteristics and in the 2nd case the car must be provided with a safety gear.

In the formation of the cylinder according to the invention, are the two cylinders, as shown in FIG. 1, are arranged next to one another and with one another connected so that 1 piston can extend upwards and the other downwards. There the downward extending piston presses on an abutment, becomes the cylinder system moved up. The piston moving upwards thus moves around its own Lifting height up plus lifting height of the 2nd piston. So the entire stroke is almost double as big as the cylinder length.

To the moment created by the side by side arrangement of the cylinders To make it ineffective, 3 cylinders can be combined as shown in Figure 2. It is advantageous to choose the piston area of one cylinder as large as the entire one Piston surfaces of the other two cylinders.

With 4 cylinders of the same size, a combination can be made accordingly Execute Figure 3, also outside of the cylinder system, no moment acts.

Claims (3)

Claims Ü) Hydraulic or pneumatic cylinders for elevators and Hoists characterized by: a) The 2 cylinders connected side by side and such are arranged that 1 piston after one and the other piston after the other Side can extend. b) The effective piston areas aD of the two pistons are equal, so that the extension takes place at the same time. 2.) Claim according to 1, characterized in that a) 3 cylinders side by side connected and arranged so that 2 pistons to one side and 1 piston can extend to the other side, wherein b) the effective piston area of the one Piston is equal to the sum of the two piston areas of the other pistons. 3.) Claim according to 1, characterized in that a) 4 cylinders side by side connected and arranged so that 2 pistons to one side and 2 pistons extend to the other side, where b) the effective piston areas of the after one side extending piston is equal to the effective piston area of the after the other side is the extending piston.