STILL ON A CACTUS ROLL. I am well known for my inability to turn away an orphan plant. I even go searching for them. Our local Lowes has a reduced table and if I am in the area I always stop in to take a look. In the past I have found some very nice plants on that table and I get satisfaction for restoring them to good health. However, if this week I was thinking about reducing the number of potted plants I have, all thoughts were out of my head today when I espied these cactus on the $1 table.
Figure 1: A ratchet featuring gear (1) and pawl (2) mounted on base (3). A ratchet is a mechanical device that allows continuous linear or rotary motion in only one direction while preventing motion in the opposite direction. Ratchets are widely used in machinery and tools. Though something of a misnomer, ratchet is also often used to refer to ratcheting socket wrenches, a common tool with a ratcheting handle.
A ratcheting screwdriver incorporates a ratchet inside its handle, with a gear wheel and two pawls. A ratcheting screwdriver has a switch in its handle with which the user can choose which direction will be the restricted one. Thus, if driving a screw, clockwise is the restricted direction; that is, the handle won't be able to turn clockwise independently of the shaft.