Insulated block

Claim 1

The combination of a preformed building block of concrete and at least one preformed generally U-shaped open ended insulating insert therefor; said block having generally parallel and planar top and bottom surfaces with at least one top-to-bottom through cavity of generally rectangular cross section, said block also having opposite generally parallel side sections and at least two transverse webs of substantially uniform thickness extending between said side sections, integral at opposite ends with the side sections and defining said cavity in cooperation with said side sections, the said generally rectangular cross sectional configuration and dimensions of said cavity being subject to variation within a significant range during manufacture, said insert being of a light weight cellular heat insulating and fire retardant material and having an external configuration which is generally rectangular and adapted to enter said cavity in the block, the insert when so entered having its connecting portion extending along and engaging one of said webs, its opposite legs extending along and respectively engaging said opposite side sections of the block, and its open end and the end surfaces of its legs adjacent the opposite web, the insert thus being disposed with top and bottom surfaces of its legs and connecting portion adjacent and substantially parallel respectively with said block top and bottom surfaces and defining a second and somewhat smaller top-to-bottom through cavity within itself, and the dimension between said top and bottom insert surfaces being equal to or less than the corresponding dimension between the block top and bottom surfaces such that neither of said surfaces projects beyond the adjacent block top and bottom surface, and said insert being cross sectionally compressible with its legs slightly flexible transversely so as to accommodate said cross sectional variation in said block cavity and to provide for slight compression and firm engagement of insert external surfaces with the cavity wall and for secure frictional retention of the insert in the block cavity, said transverse block web adjacent said end surfaces of the insert and its open end having a pair of similar top-to-bottom through slots extending respectively adjacent said leg end surfaces, and said insert legs being sufficiently long and flexible respectively to enter said slots, said transverse block web adjacent said connecting web also having a top-to-bottom through slot, said insert having an integral external top-to-bottom extending projection on its said connecting portion entering said slot, and each of said slots having a depth at least one fourth (1/4) the thickness of its web, so as to locally reduce the web thickness, a width at least three fourths (3/4) of an inch, and a total volume equal to at least one fourth (1/4) the volume found by multiplying web thickness times web height times the width at the mouth of the slot.