The permitted deflection (40 to 50 mm) of the suspended mass in relation to the mounting base limits reaction under shock. No efficient vibration protection is offerred during shock.
– Natural frequency (vertical and lateral) under load of 5 to 8 Hz.
– Maximum deflection under load: – vertical : ± 50 mm*; lateral : ± 45 mm*.
– H in rest position.
– H – 6 mm under nominal load (deflection under load = 6 mm).
* maximum forces corresponding to 10 times the load.
The SANDWICH mounting comprises one or more layers of elastomer bonded to flat, parallel metallic plates. These mountings may be cylindrical or rectangular. They are designed to withstand very high compressive loads. The range of mechanical characteristics is governed by the hardness of the rubber and the number of intermediate metallic plates.
These mountings can support compression from 20 to 100 bars.
The metal plates usually receive a phosphate anti-corrosion treatment.
The elastomer is polychloroprene which provides a high resistance to atmospheric exposure.
These parts are usually supplied in VHDS (very high density silicone) rubber and the full reference should include:
– the letter S,
– the appropriate grade which corresponds:
– to the youngs modulus of the rubber under static compression in accordance with ASTM D945 (ref. 33 to 77),
– or to the stiffness measured on a part (ref. 16 to 25).
There are several types of stops:
– Cylindrical or DIABOLO stops.
– Conical progressive stops.
– LEVAFLEX progressive stops with central cavity.
– EVIDGOM stops.
The EVIDGOM mounting is formed from two thick conical membranes, joined at their bases to create a highly elastic mounting.
There are three variations:
– All rubber EVIDGOM.
– EVIDGOM with bonded fixing.
– EVIDGOM with a diamond or square mounting plate (fixing plate supplied as a separate kit).
