Industrial manufacturers of machines or vehicles are organized in different assembly lines. During this construction stage, operators assemble heavy pieces that constitute the machine to be manufactured. Some need to be wedged or adjusted to assure a perfect mechanical assembly and the proper functioning of the machine.

Unfortunately, those actions can be complicated by small spacing or by strong thrusts. Those complications increase the risk of work accidents for the operators performing the wedging of industrial parts with non adapted tools such as the manual effort lever.

The wedging of parts during the mechanical assembly

A french manufacturer of handling equipment came to us with the objective to find an inflatable wedging and adjustment system for its parts. Indeed, on their production line, their operators have to wedge heavy parts, even very heavy ones such as the inner boom of the telescopic arm. This one must be held and pushed into place to set the wedges.

Until today, operators were using manual effort levers. Those levers have very small and metallic effort surfaces. In addition, by using this tool by hand, the agents are close to the machine and to the strong thrusts parts. When tilting and pushing, the tool can slip at any time. The operators could find themselves clamped with the hand clenched between the parts, which would return to their original position.

The cases of work accidents are then high, resulting in handicaps for the staff concerned. On the industry side, this will lead to administrative procedures, time losses on the machine’s manufacturing, and finally money losses.

This is why the manufacturer was looking for a more reliable, more secure, and simpler solution to protect his staff. To meet his needs, some constraints had to be respected :

  • weight to be pushed: about 100kg,
  • available width: 100 mm,
  • available length: 3 to 4 m,
  • insertion zone: between 5 and 10 mm,
  • lifting height: 4mm.
Lifting bag for wedging parts

Pronal Lifting bag as an inflatable effort lever

To meet the needs of our partner, we diverted one of our leading products: the VTR lifting bag. This inflatable solution is used in particular by electrical transformers, for the wedging and adjustment of their winding.

Its conception and qualities allow it to meet every expectation of the users. As for its basic use, it has many advantages :

  • protection of the  pressurized parts thanks to its flexible surface,
  • simple and fast use compared to traditional methods,
  • reduction of the operators working time,
  • easy insertion in the most confined spaces thanks to its low thickness,
  • tailored to each situation.
wedging of parts
calage de piéces

As its contact surface with the parts is larger than the metallic lever, the thrust is better distributed. In addition, being made of rubber, its adherence means that it does not slip against smooth surfaces of the parts. The risks of work accidents are then drastically reduced.

The use of the inflatable system is simple. It is done with the help of an air inlet which will put the solution under pressure. This application allows the operator to have more distance on the heavy mechanical part and to be more protected. Thanks to the lifting bag, he gains in safety but also in comfort because once inflated, the operator can use both of his hands. The system is also fast to use, speeding up the wedging part and thus, the production lines of the handling equipment.

Therefore, Pronal supplied 12 lifting bags of 9 mm wide, with a 100mm outlet in the edge for air supply.

PRONAL lifting bags are totally innovative in our company. They are used to hold the different elements of the booms of our machines during the wedging operations. The operator is then in possession of both of his hands, which brings him work comfort and safety during the operation. Those lifting bags were set up in order to replace the lever effort that we used before, which caused a few accidents because of their shifts
Production manager


Thanks to this solution, the operator saved time on the assembly of its machine. The remote inflatable system of the lifting bag has brought a work confort and significant safety during the process of wedging parts. The risk of work accidents has been reduced a lot with this solution which has replaced the lever effort. The production line has accelerated, allowing the manufacture of more machines.

Here, the lifting bags were used to push the mechanical parts. They can be used in other ways in the industrial manufacturing process like braking conveyor rollers.

inflatable liftings bags
100 kg
9 mm

Would you like more information on this project?

Vous pouvez contacter nos experts qui sont adeptes de ce genre de projet pour avoir plus d’informations et être conseillé

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