Best Times to Go to Florence, Italy. Avoid summers if you can, it's hot and packed with sweating tourists in July and August. That said, there's hardly a time you won't encounter tourists in Florence. If you must go in summer, make hotel reservations early.
Helical. Helical (adjective) is having a spiral form of many rounds. Helical can be a hairstyle curl, loop fold of a ribbon that serves as pony and a repeated dialogue of an actor that gives twist to the audience.
The helical gears are a refinement over spur gears. The teeth on helical gears are specially cut at an angle, so as to face the gear. As two teeth on the gear system engage, it starts a contact on one end of the tooth which gradually spreads with the gear rotation, until the time when both the tooth are fully engaged.