Product category:
Ballscrews, Linear Guides, Jacks, Dampers
News Release from: Huco Dynatork | Subject: Lead screws
Edited by the Engineeringtalk Editorial
Team on 06 December 2004
Lead screws help in stained glass
restoration
A bespoke and failsafe stone manipulator designed by Scorpion Lifting Systems for use in renovation work at Lincoln Cathedral includes standard Huco lead screws.
The Dean's Eye rose window at Lincoln Cathedral is testimony to the skill of 13th century craftsmen For nearly 800 years this beautiful feature has stood the test of time but, to ensure its conservation for the enjoyment of future generations, The Dean's Eye is now the subject of a substantial restoration programme
Thanks to some modern technology however, safe and secure access to this precious work of art has been assured so that new stone tracery may be installed.
The skill involved here was provided by 21st century specialist Scorpion Lifting Systems.
The bespoke and failsafe stone manipulator that Scorpion designed for this application naturally had to meet stringent demands both for the safety of personnel and for the efficient handling of window elements.
Any mishap at the window height of 150m could be truly catastrophic.
The resultant mechanism therefore comprises high performance components and includes standard Huco lead screws.
These trapezoidal threaded spindles drive the system's y- and z-axis movement.
The Scorpion stone manipulator was designed and built specifically to locate, grip and manoeuvre four particular carved stone pieces, employing special stone holding fixtures.
Although the maximum weight of these carved stones is up to 250kg, the system is in fact rated at full extension to 312kg.
The y-axis lead screw that drives the extending reach arms, comprises two elements joined by a rigid steel coupling, also supplied by Huco.
The two sections have opposite hand threads and are anchored at either end by lead screw drivers.
The arms run in two precision channels that are in turn attached to the z-axis mechanism by two heavy and bolted angle irons.
The z-axis lead screw lifts and lowers the device slideways along which the stonework and fixtures move in the z plane.
It is actuated by means of a height adjustment wrench.
A large thrust bearing is fitted between the lead-screw-supporting flange and floating bronze bush to reduce the effort required to move the z-axis slideway.
The steel lead screws supplied by Huco are manufactured to DIN103 and use rolled threads for high tensile strength and accuracy.
They are also highly resistant to abrasion and corrosion and provide a maximum lead deviation of only 0.15mm over a 300mm length.
One of the main reasons for choosing Huco lead screws for this application was their proven ability to operate efficiently in arduous conditions.
Significant airborne dust is inescapable in this Lincoln Cathedral project yet, despite this prevailing hazard, Scorpion reports lead screw performance to be "very, very good".
After many years of conservation work on the stained glass of the Dean's Eye window, the medieval stone tracery was removed during February this year and is now being recorded in detail.
The installation of the new tracery began in May and is expected to be completed by December 2004.
Isothermal glass will then be inserted on the outside of the window forming a double-glazing barrier to protect the medieval glass from the elements. Request a free brochure from Huco Dynatork ...
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