Muffler insert, and systems, methods and apparatus for making

Abstract

Sound-attenuating mufflers and muffler inserts, and systems and uses of such mufflers and muffler inserts. Continuous fiberglass roving is fed to a pneumatic jet head which fluffs the roving and presents the fluffed roving to a delivery wand at the exit end of the jet head. The delivery wand is moved along a predetermined three-dimensional path such that the wand delivery tip travels along a predetermined three-dimensional path inside a mold while-depositing fluffed fiberglass strands into the mold along the predetermined path. A terminal end portion of a liquid resin conduit is mounted to the fiberglass-dispensing wand, as part of the delivery tip, and drip-feeds liquid resin onto the fiberglass as the fiberglass is being deposited in the mold. The undulating, up and down movement of the delivery tip produces a wave-like undulating pattern in the appearance of the rovings in the resulting molded product.

1 . A molded fiberglass-based sound attenuating muffler insert core comprising a generally shape-constant cured mixture of continuous fiberglass roving and cured liquid resin binder, said insert core having an outer surface configured to interface with an inside surface of a muffler shell into which said insert core is adapted to be assembled so as to provide fiberglass-based sound attenuation in such muffler when such muffler is fully assembled,
 whereby such muffler insert core is adapted to maintaining a relatively constant shape configured to interface with such inside surface of such muffler shell,   wherein said continuous fiberglass roving has been fluffed so as to reduce a density of such roving, and wherein said fluffed roving, in elevation view, of said insert core, exhibits a conspicuously wave-like, undulating pattern.   
     
     
         2 . A muffler insert core as in  claim 1  wherein portions of said fluffed roving deviate from the wave-like undulating pattern. 
     
     
         3 . A muffler insert core as in  claim 1  wherein portions of said fluffed roving randomly deviate from the wave-like undulating pattern. 
     
     
         4 . A muffler insert core as in  claim 2  wherein portions of said fluffed roving exhibit generally isolated circular patterns. 
     
     
         5 . A muffler insert core as in  claim 1 , said insert core having been fabricated by inserting an exit wand tip of a jet head into a core mold, and moving said exit wand tip along an up and down zigzag path while delivering the fluffed fiberglass roving into the mold. 
     
     
         6 - 28 . (canceled) 
     
     
         29 . A muffler insert core as in  claim 4  wherein the circular patterns of said constrained fiberglass roving are generally isolated from one another. 
     
     
         30 . A muffler insert core as in  claim 1  wherein said fluffed fiberglass roving in said insert core comprises continuous-length fluffed fiberglass roving. 
     
     
         31 . Use of a molded fiberglass-based sound attenuating muffler insert in a vehicle muffler wherein the muffler insert comprises a combination of fiberglass roving and cured liquid resin binder, the muffler insert having an outer surface configured to interface with an inside surface of a shell of the muffler, the muffler insert being adapted to maintain a relatively constant shape while being inserted into the muffler shell, and being configured to interface with the inside surface of the muffler shell, and wherein the fiberglass roving has been fluffed so as to reduce a density of such fiberglass roving and wherein the fluffed roving, constrained by the cured liquid resin binder, in elevation view of the insert, prior to the insert being inserted into the muffler shell, exhibiting undulating, and other curvilinear, patterns, and wherein the cured liquid resin binder is susceptible to being burned off by heat of engine exhaust gases passing through the muffler whereby the burning off of the cured liquid resin binder releases the constraint of the resin binder on the fiberglass after the insert has been placed inside the muffler shell and exposed to the engine exhaust gases. 
     
     
         32 . Use of a molded fiberglass-based sound attenuating muffler insert as in  claim 31  wherein the fiberglass roving is a continuous-length fiberglass roving in the muffler insert. 
     
     
         33 . Use of a molded fiberglass-based sound attenuating muffler insert as in  claim 31  wherein portions of the fluffed constrained fiberglass roving deviates from such undulating patterns. 
     
     
         34 . Use of a molded fiberglass-based sound attenuating muffler insert as in  claim 31  wherein portions of the fluffed constrained fiberglass roving deviates randomly from such undulating patterns. 
     
     
         35 . Use of a muffler insert core as in  claim 31  wherein portions of the fluffed constrained fiberglass roving exhibit generally circular patterns. 
     
     
         36 . Use of a muffler inset core as in  claim 31  wherein the circular patterns of the constrained fiberglass roving are generally isolated from one another. 
     
     
         37 . Use of a muffler insert core as in  claim 31 , the insert core having been fabricated by inserting an exit want tip of a jet head into a core mold and moving the exit want tip along an up and down zigzag path while delivering the fluffed fiberglass roving and resin into the mold. 
     
     
         38 . Use of a muffler insert core as in  claim 31  wherein the fluffed fiberglass roving in the insert core comprises continuous-length fluffed fiberglass roving.