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US 3,942,362 AGranted
Roof truss testing machine
OwnerJames R. Kellerinventor
Life of this patent
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OwnerJames R. Kellerinventor
Estimating the term…
A truss to be tested is laid on its side on a table having an upstanding flange along one side. A load cell is interposed between one end of the bottom chord of the truss and the table flange and a block is interposed between the opposite end of the bottom chord and the table flange. A flattened flexible tube is disposed on edge along a similar flange on the opposite side of the table. Blocks are inserted between the flexible tube and the top chord of the truss to simulate a uniform snow load when the tube is inflated. One-half the total load is measured directly by the load cell and the deflection of the center of the bottom chord is measured by a scale on the table. If the deflection remains within an allowable amount so as not to close a limit switch within a prescribed loading interval, a timer actuates a rubber stamp to mark the truss as having passed the test.
A truss testing machine comprising a table adapted to support a truss lying on it side, upstanding abutment flange means on one side of said table, an abutment block on said table arranged to bear horizontally against said flange means and provide an abutment against one longitudinal edge of the truss at one end thereof, a force indicating load cell on said table arranged to bear horizontally against said flange means and provide an abutment against said edge of said truss at the opposite end thereof, an upstanding abutment flange extending along the opposite side of said table, a flattened flexible tube on said table sealed at its ends and extending along said second flange, a series of pressure transmitting blocks on said table disposed between said tube and the opposite longitudinal edge of said truss, an air pressure supply source to inflate said tube, and a vacuum supply source to evacuate said tube, the inflation of said tube causing said pressure transmitting blocks to apply substantially uniform loading along the length of the truss.
A truss testing machine for a truss having a bottom chord member and a top chord member, a flattened flexible tube closed at its ends extending the length of said top chord member and arranged to apply substantially uniform loading along the length of said top chord member when the tube is inflated, means for inflating and evacuating said tube, means engaging the ends of said bottom chord member arranged to prevent substantial movement of said ends when said top chord member is loaded by inflation of said tube, means to indicate the magnitude of said loading, and means to indicate excessive deflection of the truss under said loading.
Dependencies are inferred from the claim text.