Vein bursting is a common condition. I would recommend that you discuss this with your doctor as it may be a a sign of an underlying disorder that requires treatment. First of all, everyone occasionally experiences veins bursting. This results in an ecchymosis, or a bruise.
Couplings & Flexible Shafts. Couplings are devices used to connect two shafts together and are divided into two categories: Rigid and Flexible. Both are used for the purpose of transmitting power, rigid couplings being more limited in applications as compared to flexible couplings.
Definition of trigger. 1  1a : a piece (such as a lever) connected with a catch or detent as a means of releasing it; especially : the part of the action moved by the finger to fire a gunb : a similar movable part by which a mechanism is actuated trigger of a spray gun.