PL209812B1 - Pantograph mechanism - Google Patents

Description

The subject of the invention is a pantograph mechanism, intended for the parallel displacement of loads or members of other mechanisms attached to one of its members. Such a mechanism can be used in the processes of lifting and lowering loads while maintaining the horizontal movement of the load and without swinging it.

In the pantograph mechanism, the main body is moved in parallel through an array of arms connected to it, between itself and the base element. In order to ensure the parallel movement of the beam, it is necessary to synchronize the sides of the system. For this purpose, the arms are coupled with tie gears or gears. Such solutions provide a rigid connection between the sides of the system.

The pantograph lifting mechanism known from use has a supporting beam called a traverse, which forms the load base to which the load-bearing material is attached. The beam is moved by the proper lifting mechanism. The arms together with the beam constitute a pantograph mechanism. This mechanism is symmetrical about the vertical axis of the system. To ensure guidance of the load, it is necessary to synchronize the movement of both sides of the system. Such a system must ensure non-skid cooperation of the cable-wheel, therefore the most appropriate mechanism is a chain transmission. When the beam is lifted with the lifting mechanism, the arms rotate, and the lifting mechanism may be a cable, belt, chain, rack, hydraulic, screw or other mechanism. The drawbar of the system provides the same angle of rotation of the arms on both sides of the pantograph mechanism.

The essence of the pantograph mechanism according to the invention consists in the fact that a synchronous lifting mechanism is embedded in the support structure in the form of a system of two double-rod actuators symmetrically attached to each other, driven by the movement of the arms through joints. Moreover, the arms are mounted in flat joints fixed in the supporting structure.

Preferably, the system of two double-rod cylinders is equipped with valves that desynchronize the movement of the arms in the event of overload.

It is also advantageous if the double-rod cylinders are pivoted to the support structure by means of joints.

The advantage of the invention is the simplicity of the structure and the possibility of building protection, enabling the desynchronization of the arms movement in case of excessive load asymmetry without fear of damaging the structure. The system of double-rod cylinders is a synchronous lifting mechanism with a hydraulic drive.

The subject of the invention in an exemplary embodiment is shown in the drawing which shows the kinematic diagram of a pantograph mechanism with a synchronous hydraulic drive.

P r z k ł a d 1

The pantograph mechanism with a synchronous hydraulic drive is built on a support structure 1 which is a fixed base, relative to the other members, and the flat joints 2 connected with it, in which the arms 3 are mounted, connected with additional arms 4 with flat joints 5. Rod 6, performing parallel movement, it is connected with additional arms 4 with flat joints 7. The movement of the beam 6 is forced by the movement of the arms 3, moved by double-rod actuators 8 and 9. The arms 3 are connected through joints 10 with actuators 8 and 9.

The upward movement of the beam 6 takes place by forcing the liquid through the conduit 12 into the cylinder chamber 8. The liquid from the second cylinder chamber 8 is forced through the conduit 13 into the cylinder chamber 9, causing its piston to move symmetrically and synchronously in relation to the movement of the cylinder piston 8. The liquid from the second cylinder chamber 9 is forced into the tank through a line 14.

The downward movement of the beam causes pressure to be applied through the line 15 to the actuator chamber 8, which forces the liquid from the actuator 8 to 9 through the line 16 and forcing the liquid from the second actuator chamber 9 into the tank through the line 17.

Maintaining the symmetry of movement is guaranteed by the same chamber capacity of both actuators.

P r z k ł a d 2

The pantograph mechanism with a synchronous hydraulic drive is made as in the first example, with the difference that the actuator connection system has built-in safety valves 18 and 19, which at a certain pressure difference on both sides of the system cause the arms 3 to be desynchronised in the event of overload. Excessive pressure in one branch of the system is supposed to cause

The flow of liquid into the reservoir, rather than into the chamber of the symmetrical actuator. This arrangement protects the pantograph mechanism against damage in the event of too large differences in loads in both branches of the system.

After the safety valves are actuated, the mechanism system should be brought to symmetry.

Claims (3)

1. The pantograph mechanism has a beam for moving loads or driving members of other mechanisms, seated between the arms symmetrical with respect to the vertical axis of the system, characterized in that the supporting structure (1) has a synchronous lifting mechanism in the form of a system of two double-rod actuators (8 and 9) fixed symmetrically to each other, synchronously driving the arms (3) through the joints (10), moreover, the arms (3) are mounted in flat joints (2) fixed in the supporting structure (1). 2. The pantograph mechanism according to claim 1 The method of claim 1, characterized in that the system of two double-rod cylinders (8 and 9) is equipped with valves (18 and 19) that desynchronize the movement of the arms (3) in the event of an overload. 3. The pantograph mechanism according to claim 1 The method of claim 1, characterized in that the double-rod cylinders (9) are pivoted in the supporting structure (1) through joints (11).