TMC Catalog

Optical Tops, Breadboards, & Supports (continued)Options & Accessories (continued)ToprestraintbracketUpperand lowertiebarsFloorrestraintbracketLaser ShelfTMC tables larger than 36 in. x 72 in.(900 x 1,800 mm) and supported atleast 18 in. (450 mm) above thefloor can be fitted with a laser shelf.The shelf consists of an additionalundrilled 2 in. (50 mm) thick breadboardattached to the bottom plateof the table. Though such a supportsystem will not match the performanceof direct mounting ofequipment to the table’s top surface,for less sensitive appli cations thisarrangement can save valuableworking space on the top.In some cases, our tiebars mayinterfere with shelf mounting.Contact us if you are in doubt.Laser Shelf Ordering ChartShelfModelDescription W L81-172-01 Shelf-imperial hardware 24" 48"81-172-02 Shelf-metric hardware 600 mm 1200 mm81-173-01 Shelf-imperial hardware 24" 72"81-173-02 Shelf-metric hardware 600 mm 1800 mmOrder as a complete set or order thebreadboard separately.EarthquakeRestraint SystemTMC’s earthquake restraint bracket systemprovides increased safety and stabilityfor optical tables in high-risk earthquakeareas without affecting table performance.The TMC earthquake restraint system relieson top brackets and upper tiebars to controlmotion of the table top and, where severeoccurrences are anticipated, floor bracketswith lower tiebars to secure the supportstructure to the floor. Under normal conditions,there is no contact between the topbrackets and the support structure, so thatperformance of the optical top and thevibration isolation system are not affected.Clearances are large and brackets arelightweight, stiff, well-damped,unobtrusive and encapsulated with softelastomer to provide gradual snubbing.Our earthquake restraint bracket systemcan be retrofitted to an installed TMCoptical table or specified with a new order.Inferior, competitive designs may dependon large, pendulum-like structures thathang below the table top and connect tothe floor. Since pendulums characteristicallyhave low resonant frequencies, these addonstructures lower the resonant frequencyof the table top and degrade complianceand damping. In addition, the floorconnection creates a potential rigidcoupling between table top and floor,which can compromise vibration isolationif it drifts out of calibration.44 www.techmfg.com • 978-532-6330 • 800-542-9725 (Toll Free) • Fax: 978-531-8682 • sales@techmfg.com