We define supports the connection elements between bearing structures and articulated screws. The supports are available in two different dimensions version: with 150 mm distance hole, type Astra and Aura, and with 220 mm distance hole, type Vega and Vela. All models are realized by lost-wax casting of stainless steel Aisi 316 L and guarantee a load capacity of 200 Kgs per arm (800 Kgs. for the four-arm support). The value of resistance were calculated with FEM at design stage and subsequently guaranteed by testing carried out by internationally acknowledged institutes. (certificates
are available on request).
The accessories used for the realization of punctual structural glass façades are subject to different load combinations:
- A: Load charges that could be determined by wind pressure and snow load, in case of rooftops and coverings, that create a perpendicular stress on the glass pane;
- B: Charges created by the glass weight that gives a shearing force on the articulated screws (rotules) and so a parallel stress on the glass pane;
- C: Additional tension due to thermic expansion in case the fixing system is too constrained.
For this reason the support has different types of hole.
The purpose of different drilling typologies on the support arm is to absorb the various expansion and stress of the glass and further to give more regulation during the installation. The diagram illustrates drilling type A that present on the top left arm has a 15 mm diameter hole which do not allows any movement of the articulated screw and fix strongly the glass to the structure; then presents on the top right arm has a slot hole that allows the sliding on the horizontal axis; in the end the two bottom arms have 20 mm diameter holes that allow the expansion on the vertical and oblique axis.
According to the position of the support into the facade the project planner should indicate the different drilling typology. Using this method the direction of the expansion is fixed thus avoiding the creation of critical points of pressure between glass sheets that can be really dangerous for glass resistance.
- A: Metallic structures carpentry made with steel or iron piles or beams.
- B: Tension or flexible structures, by this type of structure is possible to obtain facade with a visual aspect very light and clear, the dimension of the structure is only the cable and the spacer between cable and supports.
- C: Mixed structure where are used both previous typology of structures.