This form of billiards is usually equipped with sixteen balls-a cue ball and fifteen object balls-all of them played on a pool table that has six pockets built into the rails that split the cushions. If you hit that exact spot with the cue ball then the object ball will be pocketed. If you’re aiming the center of the cue ball to hit the coin, then you’re going to miss. Billiards is a reference name given to three different cue sports. Yet other sources indicate that a variant of a ball-and-mallet game evolved into Billiards. Transform your leisure area with our top-rated game tables. Lightweight: Wooden tables are lighter than slate tables, making them easier to move or reposition. Longer handles are as a rule better in torque tools; the farther from the plug the torque can be applied, the easier it is to detect and control fine movement. Right: With all of the cuts at the shear line, the plug can rotate freely within the shell. Right: Side view, with part of the shell and plug cut away to expose the six pin stacks. Rotation of the plug within the shell operates the locking mechanism. In the locked state the plug is prevented from rotating by a set of movable pin stacks, typically under spring pressure, that protrude from holes in the top of the opening in the shell into corresponding holes drilled into the top of the plug.

See Figure 2. The plug will be blocked from rotating if any pin stack is lifted either not far enough (with the cut still in the plug below the shear line) or too far (with the cut pushed above the shear line and into the shell); to rotate, all pin stacks must have a cut at the shear line. Left: The correct key lifts the pin stacks to align the cuts at the shear line. The plug/shell border is called the shear line. Pin tumbler lock picking consists of raising the cuts on each pin stack to the shear line, one by one, until the plug turns freely. Note the border between the plug and shell, which forms the shear line, and the cuts in each pin stack resting within the plug. See Figure 1. (In practice, the cuts are produced by stacking pin segments of particular lengths, not by actually cutting the pins; hence the term "pin stack.") With no key in the lock, all the pin stack cuts rest within the plug. And of course there is the surest and fastest method of all: the use of the correct key. Picking locks requires skill, practice, and the use of rather unusual (and not widely available) tools.

With practice, even this keyway will eventually seem easy to maneuver. In practice, of course, locks aren't perfect: the pin holes in the plug are slightly out of alignment with respect to the shell and the pins and pin holes are each of a slightly different diameter. In an ideal lock, all of the pin holes in the plug would be in perfect alignment with the corresponding holes in the shell, the centerline of the plug would be exactly parallel to that of the shell, and all of the pins would be exactly the same diameter. Other classes of attack, not discussed here but at least as worthy of study and scrutiny, include lock decoding, which is concerned with producing a working key based only on access to the external interface of the lock, lock bypass, which aims to unlatch the underlying locking mechanism without operating the lock at all, and forced entry, which, as the term suggests, involves the destructive application of force to the lock or its surroundings. The height (or cut depth) of a key under each pin stack position is called its bitting; the bitting of a key is the "secret" needed to open a lock.

It's aimed at working locksmiths, and has a broad discussion of picking techniques and principles, albeit with less depth than the Finch book. A key that is bitted to the wrong depth in even one pin position will not operate the lock. Criminals generally prefer either procuring a key or forced entry for speed, certainty, and stealth, notwithstanding whatever property damage or evidence is left behind. From the attacker's perspective, too, lock picking is rarely the most efficient, most economical, fastest, or easiest method of entry. Surreptitious entry (e.g., for espionage or law enforcement surveillance) is likewise often best accomplished by obtaining a key or through the use of specialized decoding or bypass tools designed to quickly and quietly defeat the locks used by the target. When a key is inserted into the keyway slot at the front of the plug, the pin stacks are raised within the plug and shell. The plug can rotate freely only if the key lifts every pin stack's cut to align at the border between the plug and shell. Left: Cylinder face, the lock's "user interface." Note the keyway, which is cut into the plug, which in turn sits inside the shell. The basic design consists of a rotatable cylinder tube, called the plug, linked to the underlying locking mechanism.

In case you loved this information and you would like to receive more info about what is billiards kindly visit our own web site.

• 이전글
• 다음글

• 수정
• 삭제
• 목록
• 글쓰기