1) пружина
2) источник, родник
3) нижняя часть (арки, свода)
- air spring
- bow spring
- buffer spring
- close-wound spring
- constant-force spring
- contact spring
- cussion spring
- damping spring
- door spring
- door hinge spring
- flat spring
- hard spring
- helical spring
- hillside spring
- latch spring
- retaining spring
- return spring
- stratum spring
- weightless spring