Bridge movement In modern watch movements, the back plate is replaced with a series of plates or bars, called bridges. Three-quarter plate movement In the 18th century, to make movements thinner, part of the back plate was cut away to make room for the balance and balance cock. All the parts of the watch were mounted between the two plates except the balance wheel, which was mounted on the outside of the back plate, held by a bracket called the balance cock. The back plate has various shapes:įull plate movement In this design, used in the earliest pocketwatches until the 18th century, the back plate was also circular. One of these plates, the front plate just behind the face, is always circular, or the same shape and dimensions as the movement. In watch movements the wheels and other moving parts are mounted between two plates, which are held a small distance apart with pillars to make a rigid framework for the movement. The movement parts are separated into two main categories: those belonging to the ébauches and those belonging to the assortments. Each specific watch movement is called a caliber. Watch movements come in various shapes to fit different case styles, such as round, tonneau, rectangular, rectangular with cut corners, oval and baguette, and are measured in lignes, or in millimetres. Types of movements A modern bridge watch movement Pendulums usually have an adjustment nut under the bob, while balance wheels have a regulator lever on the balance spring. The oscillator always has some means for adjusting the rate of the clock. A pendulum movement has a pendulum hangar usually attached to a sturdy support on the back, from which the pendulum is suspended and a fork which gives the pendulum impulses. It swings back and forth, with a precisely constant time interval between each swing, called the beat. Oscillator The timekeeping element, either a pendulum or a balance wheel. Each time the escape wheel moves forward it also gives the pendulum or balance wheel a push to keep it moving. It consists of a gear called an escape wheel which is released one tooth at a time by a lever that rocks back and forth. Escapement An escapement is a mechanism that allows the wheel train to advance, or escape a fixed amount with each swing of the balance wheel or pendulum. A separate set of wheels, the motion work, divides the motion of the minute hand by 12 to move the hour hand and in watches another set, the keyless work, allows the hands to be set. The wheels in a typical going train are the centre wheel, third wheel, and fourth wheel. Large gears known as wheels mesh with small gears known as pinions. Wheel train A wheel train is a gear train that transmits the force of the power source to the escapement. The barrel or pulley has gear teeth on it which drives the center wheel. The mainspring or pulley has a mechanism to allow it to be wound up, which includes a ratchet to prevent it from unwinding. The movement is made of the following components: Power source Either a mainspring, or a weight suspended from a cord wrapped around a pulley. Mechanical movements Ī mechanical movement contains all the moving parts of a watch or clock except the hands, and in the case of pendulum clocks, the pendulum and driving weights. One source recommends servicing intervals of: 3–5 years for watches, 15–20 years for grandfather clocks, 10–15 years for wall or mantel clocks, 15–20 years for anniversary clocks, and 7 years for cuckoo clocks, with the longer intervals applying to antique timepieces. Mechanical movements get dirty and the lubricants dry up, so they must periodically be disassembled, cleaned, and lubricated. When buying a quality pocketwatch from the mid-19th to the mid-20th century, for example, the customer would select a movement and case individually. In modern mass-produced clocks and watches, the same movement is often inserted into many different styles of case. The movement of a digital watch is more commonly known as a module. The term originated with mechanical timepieces, whose clockwork movements are made of many moving parts. In horology, a movement, also known as a caliber or calibre ( British English), is the mechanism of a watch or timepiece, as opposed to the case, which encloses and protects the movement, and the face, which displays the time.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |