The Tower Clock
08.09.10
Historically, you can trace the development of mechanical watches for different types and in relation to regional conditions , which had considerable influence on the occurrence of the important centers of the watch industry , the establishment of schools watchmakers world significance and to differentiate the level of craft and art industry in various European countries and other parts of the world .
The main and almost the only material clock , especially in the early period of their construction, it was iron , from which produced not only all of the frame, and shafts , gears , tribe , etc. Medieval blacksmiths and metalworkers were , strictly speaking , the first watchmakers that created large clock . Forge technique strongly influenced the design elements of the mechanism , such as a wedge connection of the frame , the fastening gear lateral wedges on the shafts to protect against axial displacement. Permanent connection happens then riveted or welded.
Significant changes in the shape can be traced primarily to frames hours . Bearing Angle column in the oldest tower clock originally had a shape similar to the reference columns of the temple , on the transverse and longitudinal strips frame they were usually rotated by 45 °. Sometimes the frame is not solid and resembles a bird-cage , had a light design . Corner column , also from flat metal strips , and later began to make straight. From above , they ended decorated ornamental heads , and below – legs . Ornamental elements were initially form polygonal pyramidal or round heads , borne by an arched shank.
Since the beginning of XVII century. increasingly began to appear on the clock flat heads of riveted iron , bent into curls . Around the same time, maybe a little earlier , there were pointed forged heads , such as a turret mechanism, which was originally installed on the tower of the fortress Orlik in South Bohemia . Some tower clock XVII century. found bearing columns of circular section .
With a monumental clock tower at Westminster Palace in London, appeared in the construction of tower clocks , some new elements . Besides the already mentioned differential locking the shutter , there were already significant changes in the frame. Instead of the usual cage frame , which was used for centuries, Dent and Denison prefers a horizontal frame with rollers arranged in a common horizontal plane.
There is no doubt that the production of gears was the most difficult of all construction hours. Large gear clock produced separate parts , which are then assembled into a coherent whole . The main bearing element of such gear has been the hub , usually with four luchevidnymi spokes.
The ends of the spokes pass through the side of the crown with machined gear cutting. Fixed connections made by welding in the forge . Sometimes the weld replaced or strengthened by rivets. A detailed examination of the crown gear then shows a method of manufacturing the teeth . On the sides of crowns of certain mechanisms are still traces of labeled circles basins , showing the height of the teeth . The tops of teeth watchmakers mark cores .
The line connecting beaten Punch deepening of the wheel center showed the symmetry axis of the tooth profile . Shafts of the wheels were originally four-sided cross-section , six – or octahedral , and later became watchmakers prefer round profiles . Tsevochnye ( alfalfa ), tribe , usual clock , are the following example of prefabricated parts of the clock mechanism . In punched or drilled holes in their ends were fixed studs , steel tubes that serve as teeth. Riveted kit is placed on the shaft and secured by transverse wedge longitudinal displacement .
Several of these indications of the old technology could lead to the mistaken view that the medieval watchmakers worked with only very limited means and methods. However, we must not forget that even with half of the XIV century . began to emerge in Europe first chime with sophisticated astronomical instruments , which could not do without concentric hollow shafts .
These concentric shafts were , according to store messages , and paduevskie Chimes , built in the 60- ies of the XIV century . Giovanni Dondinom , as well as about half a century younger Prague’s Astronomical Clock . The successful solution for those times certainly complicated the production of long hollow shafts was a prerequisite for mutual images day and night movement of the sun, moon and stars on the general round clock face .
Effect of isolation of Britain from the early directions of technological development of watchmaking in the European continent , is characteristic of this country, however, and later , visibly manifested in the construction of British clock , which, along with the classic cage frame appeared very simple vertical frame with horizontal axes of wheels located in a common vertical plane. As in other countries, in England, iron was very expensive material .
Therefore, some English watchmakers from the Mainland were made of iron very limited number of parts , such as shafts and gears , but the frame of hours , they produced only from the thick wooden beams . One of the few surviving evidence of this are , for example , old wooden clock tower in Heddon Hall in Derbyshire . In the western areas of England, rich in iron ore , a frame clock produced in most cases of iron . Opening with a wooden or metal vertical frame , which became characteristic of the British towers ” chasostroitelstva , yet still preserved in various cities of this country – in Cal stock , Cornwall, at the Tower of St. Nicholas in Dorset and in some other cities .
Mention should be made giryah , which remained for centuries one of the traditional means of driving more hours. During the first three centuries since the emergence of mechanical watches , such weights are made entirely of stone .At the tower they were first raised by hand using a large clockwork wheels, equipped with multiple handles for staff . Clockwork wheel is mounted directly on the drum shaft drive wheel . The difficulty of lifting cargo weighing up to several quintals forced to seek for this lifting , which appeared in the form of gear consisting of a small tribe on the auxiliary winding shaft and a large gear with a latch and ratchet wheel on the drive shaft .
Tags: horizontal frame, material clock, mechanical watches, monumental clock, separate parts, Tower Clock