A needle dam is a weir designed to maintain the level or flow of a river through the use of thin "needles" of wood. The needles are leaned against a solid frame and are not intended to be water-tight. Individual needles can be added or removed by hand to constrict the flow of the river, forming a sluice. Image File history File links Download high resolution version (1024x768, 125 KB) Needle dam in the Reuss River, Lucerne, Switzerland File links The following pages link to this file: Lake Lucerne Reuss River Needle dam ... Image File history File links Download high resolution version (1024x768, 125 KB) Needle dam in the Reuss River, Lucerne, Switzerland File links The following pages link to this file: Lake Lucerne Reuss River Needle dam ... The River Reuss is one of the larger rivers in Switzerland. ... Lucerne (German: Luzern) is a city in Central Switzerland with a population of 60,274 (31 December 2003), capital of the canton of Lucerne. ... The bridge and weir mechanism at Sturminster Newton on the River Stour, Dorset. ... A sluice is a water channel that is controlled at its head by a gate. ...
One early needle dam maintains the level of Lake Lucerne in Lucerne, Switzerland by restricting the flow of the Reuss River. Other needle dams were built in the United States in the 19th century. Lake Lucerne (German: Vierwaldstättersee, lit. ... Lucerne (German: Luzern) is a city in Central Switzerland with a population of 60,274 (31 December 2003), capital of the canton of Lucerne. ... The River Reuss is one of the larger rivers in Switzerland. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ...
Once the dam is in place, a second needle fills in the dam perimeter to the top of the dam with a lower-viscosity encapsulant.
The needle dispenses encapsulant in a spiral pattern as it moves toward the center of the fill area.
This positional control is crucial when dam material is dispensed as close as.005" from the wire bond or component area, and the dispenser must be positioned at less than half of the clearance (.0025").
Feeds |
Contact