Making Blobs with a Textile Mould 315 Fig.23.Width cross sections 5.4 Manipulating Inflated Elements The possibilities to fundamentally change the form of an inflated structure are lim- ited.The form can merely be influenced.The curvatures are always existent and that is also the intention.There are simple examples from daily life where inflated structures are used and deformed.For example a car tire has a flat outer surface. In the rubber of the tire steel rings are embedded to prevent the tire from having a round cross-section (Fig.24).An airbed is also an example where the form is influenced.There are partitions that hold the upper and lower side together when the airbed is inflated.These partitions make the cavities that exist in an airbed.In this way different sorts of shapes can be made with the aid of pneumatic structures. A number of possibilities to influence pneumatic forms will shortly be described. Pressure Surfaces By pressing two sides of a pneu with the aid of 2 so-called pressure surfaces,the pneu gets an elliptic shape.At the contact surface with the pressure surfaces,the pneu will follow the form of the pressure surfaces.The same effect appears when two pneus are pushed against each other.The contact surface is in this case flat (Fig. 25)- Fig.24.Cross-sections of a bicycle Fig.25.Pneu with pressure surfaces tire and a car tire Tension Cable By tightening a tension cable around a pneu,the pneu can be laced up.At the position of the tension cable a sharp line appears (Fig.26).Making Blobs with a Textile Mould 315 Fig. 23. Width cross sections 5.4 Manipulating Inflated Elements The possibilities to fundamentally change the form of an inflated structure are lim￾ited. The form can merely be influenced. The curvatures are always existent and that is also the intention. There are simple examples from daily life where inflated structures are used and deformed. For example a car tire has a flat outer surface. In the rubber of the tire steel rings are embedded to prevent the tire from having a round cross-section (Fig. 24). An airbed is also an example where the form is influenced. There are partitions that hold the upper and lower side together when the airbed is inflated. These partitions make the cavities that exist in an airbed. In this way different sorts of shapes can be made with the aid of pneumatic structures. A number of possibilities to influence pneumatic forms will shortly be described. Pressure Surfaces By pressing two sides of a pneu with the aid of 2 so-called pressure surfaces, the pneu gets an elliptic shape. At the contact surface with the pressure surfaces, the pneu will follow the form of the pressure surfaces. The same effect appears when two pneus are pushed against each other. The contact surface is in this case flat (Fig. 25). Fig. 24. Cross-sections of a bicycle tire and a car tire Fig. 25. Pneu with pressure surfaces Tension Cable By tightening a tension cable around a pneu, the pneu can be laced up. At the position of the tension cable a sharp line appears (Fig. 26)