ACOUSTIC SHIELD FOR WOODWORKING MACHINE Russian patent published in 2007 - IPC B27B5/29 

FIELD: woodworking equipment, particularly noise-reduction components thereof.

SUBSTANCE: acoustic shield comprises case and damping chambers arranged inside the case and provided with orifices made in damping chamber orifice from sawing disc sides. Each orifice has compressed air cavity and is provided with sound-absorbing insert with acoustic material arranged therein. The sound-absorbing insert is separated from compressed air cavity with partition. Some orifices of each damping chamber are communicated through channels made as projections of orifices and made in acoustic material of sound-absorbing insert and partition, which isolates damping chamber from compressed air cavity. Damping chamber orifices are made as slot perforations having perforation factor of not less than 0.25. Sound-absorbing insert is made as integral member or is assembled of sound-absorbing members. Each sound-absorbing member has case inscribed in corresponding damping chamber contour. Front and rear walls of sound-absorbing member cases are made of stainless steel or galvanized sheet having 0.7 mm thickness and provided with 25÷50 μm polymeric protective-and-decorative coating or of 1.0 mm aluminum sheet with 25 μm coating. Case height h is related to width b thereof as h/b=1.0÷2.0. Optimal ratio between assembled case thickness s' and width b thereof is s'/b=0.1÷0.15. Optimal ratio between acoustic material thickness s and assembled case thickness s' is s/s'=0.4÷1.0.

EFFECT: increased noise damping efficiency and decreased energy output for noise damping.

6 cl, 2 dwg