 Image Number 3 for United States Patent #4284443.
A single stage hot bonding process for manufacturing composite honeycomb core structures, such as airplane control surface structures, capable of withstanding bending and shear stresses, is disclosed. The single stage hot bonding process includes the steps of bonding a low density honeycomb core to a high density honeycomb core, shaping the combined honeycomb core, adhesively attaching spar caps to opposing surfaces of the high density honeycomb core, adhesively attaching a skin to the spar caps and the low density honeycomb core and curing the composite structure in an autoclave. Additionally, if the low density honeycomb core is shaped so that its upper and/or lower surfaces slope toward the opposing surface and join in an edge opposite the high density honeycomb core, such as in the case of airplane control surface structures, the hot bonding process further includes the steps of securing a tab of cured adhesive to the edge of the low density core before the skin is attached, and securing the tab during curing so as to prevent the lateral component of the fluid pressure in the autoclave from causing the lateral movement of the core relative to the skin.
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