Means and method for tensioning wire

Claim 2

A FACILITY FOR MANUFACTURING CORED PRESTRESSED CONCRETE SLABS HAVING A LENGTH NO GREATER THAN ABOUT 60 FEET, EACH SLAB HAVING AN INTEGRAL HOMOGENEOUS MASS OF CONCRETE WITHIN WHICH ARE INDIVIDUALLY TENSIONED STEEL STRANDS LONGITUDINALLY OF THE SLABS WITHIN THE CONCRETE AND BONDED THERETO THROUGHOUT THE LENGTH THEREOF, SAID FACILITY INCLUDING A STEEL CASTING FORM STRUCTURE HAVING A WALL PORTION THROUGH WHICH STRANDS TO BE TENSIONED EXTEND TO PROVIDE EXTRA STRAND LENGTH, A SLEEVE-LIKE STRAND CHUCK ADAPTED TO BE DISPOSED ABOUT A STRAND AT THE EXTRA STRAND LENGTH, SAID STRAND CHUCK, WHEN INSTALLED AND GRIPPING SAID STRAND, PREMITTING THE STRAND THEREIN TO REMAIN STRAIGHT, MEANS FOR ENGAGING SAID STRAND CHUCK AND TENSIONING SAID EXTRA STRAND LENGTH, SAID STRAND CHUCK MOVING WITH STRAND ELONGATION AWAY FROM THE CASTING WALL PORTION, AND MEANS DISPOSED BETWEEN SAID WALL PORTION OF SAID CASTING FORM STRUCTURE AND SAID STRAND CHUCK AND PHYSICALLY SEPARATE FROM SAID CHUCK AND HAVING PASSAGES THERETHROUGH FOR LOOSELY ACCOMMODATING A STRAND TO PROVIDE INCOMPRESSIBLE SPACING MEANS ABOUT SAID EXTRA STRAND LENGTH BETWEEN SAID CHUCK AND WALL PORTION, SAID INCOMPRESSIBLE SPACING MEANS INCLUDING SLEEVE-LIKE COOPERATIVELY THREADED MEMBERS ADAPTED TO BE TURNED WITH RESPECT TO EACH OTHER FOR TELESCOPING ACTION FOR LENGTH ADJUSTMENT, SAID INCOMPRESSIBLE SPACING MEANS ALSO INCLUDING MEANS FOR EXPOSING PART OF THE EXTRA STRAND LENGTH BETWEEN SAID CHUCK AND SAID WALL PORTION TO STRAND SEVERING MEANS WHEREBY AFTER STRAND TENSIONING AND ELONGATION AND AFTER ADJUSTMENT OF THE LENGTH OF SAID SPACING MEANS AND TRANSFER OF THE STRAND TENSIONING FORCE TO SAID SPACING MEANS (RESULTING FROM THE REMOVAL OF EXTERNAL STRAND TENSIONING MEANS), SAID CASTING FORM AND ASSOCIATED INCOMPRESSIBLE SPACING MEANS AND STRAND CHUCKS WITH TENSIONED STRANDS MAY BE HANDLED FOR CURING OF THE CASTING AND THEREAFTER PERMIT STRAND SEVERANCE AT THE EXPOSED EXTRA STRAND LENGTH PORTION TO RELIEVE THE TENSION THROUGHOUT THE EXTRA STRAND LENGTH, SAID THREADED LENGTH ADJUSTING MEANS REQUIRING ADJUSTMENT ONLY WHEN SAID EXTRA STRAND LENGTH IS SUBSTANTIALLY FREE OF TENSION AND OBVIATING THE NECESSITY FOR USING CONSIDERABLE TURNING FORCE AT ANY TIME.

Claim 3

IN THE MANUFACTURE OF PRESTRESSED CONCRETE SLABS HAVING STEEL STRANDS LONGITUDINALLY THEREOF BONDED TO THE CONCRETE AND LONGITUDINALLY TENSIONED TO A SUFFICIENTLY HIGH DEGREE AND THE SLABS HAVING SUCH A LENGTH THAT A REDUCTION IN STRAND ELONGATION INCIDENT TO THE STRAND GRIPPING ACTION OF A STRAND CHUCK OF THE TYPE HAVING JAWS BEARING ON A STRAIGHTING LENGTH OF STRAND RESULTS IN A SIGNIFICANT DROP IN STRAND TENSION, THE STEPS WHICH COMPRISE: DISPOSING A STRAND LONGITUDINALLY OF A CASTING FORM AT A DESIRED POSITION IN THE CASTING REGION WITH SAID STRAND EXTENDING BEYOND SAID CASTING FORM THROUGH AT LEAST ONE END OF THE CASTING FORM TO PROVIDE A STRAND GRIPPING PORTION EXTERNALLY BEYOND SAID ONE CASTING FORM END, ANCHORING THE STRAND PORTION ADJACENT THE OTHER CASTING FORM AND TO PERMIT STRAND TENSIONING FROM SAID EXTERNAL STRAND GRIPPING PORTION, APPLYING A STRAND CHUCK OF THE AFOREMENTIONED TYPE TO A PART OF THE STRAND GRIPPING PORTION, TENSIONING SAID STRAND TO CAUSE STRAND ELONGATION AND MOVEMENT OF SAID STRAND CHUCK AWAY FROM SAID ONE CASTING FORM END UNTIL A DESIRED STRAND TENSION HAS BEEN OBTAINED, ADJUSTING THE OVERALL LENGTH BETWEEN THE CHUCK GRIPPING PART AND A STATIONARY FORM PART OF A SUBSTANTIALLY INCOMPRESSIBLE METALLIC SPACING MEANS LOOSELY DISPOSED ABOUT THE TENSIONED STRAND LENGTH EXTERNALLY OF THE CASTING FORM TO TAKE UP ALL ADDED STRAND LENGTH WITHOUT CHANGING THE STRAND TENSION, SAID ADJUSTING INCLUDING THE STEP OF RELATIVELY ROTATING TWO, TELESCOPING, COOPERATIVELY THREADED METAL MEMBERS DISPOSED OVER TENSIONED STRAND AND HAVING AN OPEN AREA EXPOSING SAID STRAND, FREEING SAID STRAND CHUCK FROM EXTERNAL FORCE GENERATING MEANS USED IN STRAND TENSIONING TO TRANSFER THE FORCE FOR MAINTAINING STRAND TENSION TO SAID SUBSTANTIALLY INCOMPRESSIBLE SPACING MEANS, REPEATING THE STRAND TENSIONING PROCEDURE FOR DESIRED SLAB STRANDS, CASTING THE CONCRETE SLAB IN THE CASTING FORM, SAID CASTING INCLUDING DISPOSING THE ENTIRE FORM AND ASSOCIATED INCOMPRESSIBLE SPACING MEANS AND STRAND CHUCK FOR EACH TENSIONED STRAND IN AN ENVIRONMENT FOR CURING TO ESTABLISH A BOND BETWEEN TENSIONED STRANDS AND CONCRETE, AND AFTER CURING, SEVERING EACH TENSIONED STRAND THROUGH SAID OPEN AREA AT A REGION BETWEEN THE STRAND CHUCK AND SAID ONE END OF THE CASTING FROM WHEREBY SAID STRAND CHUCK IS RE-USABLE AND SAID COOPERATIVELY THREADED MEMBERS MAY BE EASILY TURNED WITH RESPECT TO EACH OTHER FOR DISASSEMBLY.

Claim 4

IN THE MANUFACTURE OF PRESTRESSED CONCRETE SLABS HAVING STEEL STRANDS LONGITUDINALLY THEREOF BONDED TO THE CONCRETE AND LONGITUDINALLY TENSIONED TO A SUFFICIENTLY HIGH DEGREE AND THE SLABS HAVING SUCH A LENGTH THAT A REDUCTION IN STRAND ELONGATION INCIDENT TO THE STRAND GRIPPING ACTION OF A STRAND CHUCK OF THE TYPE HAVING JAWS BEARING ON A STRAIGHTING LENGTH OF STRAND RESULTS IN A SIGNIFICANT DROP IN STRAND TENSION, THE STEPS WHICH COMPRISE: DISPOSING A STRAND LONGITUDINALLY OF A CASTING FORM AT A DESIRED POSITION IN THE CASTING REGION WITH SAID STRAND EXTENDING BEYOND SAID CASTING FORM THROUGH AT LEAST ONE END OF THE CASTING FORM TO PROVIDE A STRAND GRIPPING PORTION EXTERNALLY BEYOND SAID ONE CASTING FORM END, ANCHORING THE STRAND PORTION ADJACENT THE OTHER CASTING FORM AND TO PERMIT STRAND TENSIONING FROM SAID EXTERNAL STRAND GRIPPING PORTION, APPLYING A STRAND CHUCK OF THE AFOREMENTIONED TYPE TO A PART OF THE STRAND GRIPPING PORTION, TENSIONING SAID STRAND TO CAUSE STRAND ELONGATION AND MOVEMENT OF SAID STRAND CHUCK AWAY FROM SAID ONE CASTING FORM END UNTIL A DESIRED STRAND TENSION HAS BEEN OBTAINED, ADJUSTING THE OVERALL LENGTH BETWEEN THE CHUCK GRIPPING PART AND A STATIONARY FORM PART OF A SUBSTANTIALLY INCOMPRESSIBLE METALLIC SPACING MEANS LOOSELY DISPOSED ABOUT THE TENSIONED STRAND LENGTH EXTERNALLY OF THE CASTING FORM TO TAKE UP ALL ADDED STRAND LENGTH WITHOUT CHANGING THE STRAND TENSION, SAID ADJUSTING INCLUDING THE STEP OF RELATIVELY ROTATING TWO, TELESCOPING, COOPERATIVELY THREADED METAL MEMBERS DISPOSED OVER TENSIONED STRAND AND HAVING AN OPEN AREA EXPOSING SAID STRAND, FREEING SAID STRAND CHUCK FROM EXTERNAL FORCE GENERATING MEANS USED IN STRAND TENSIONING TO TRANSFER THE FORCE FOR MAINTAINING STRAND TENSION TO SAID SUBSTANTIALLY INCOMPRESSIBLE SPACING MEANS, REPEATING THE STRAND TENSIONING PROCEDURE FOR DESIRED SLAB STRANDS, CASTING THE CONCRETE SLAB IN THE CASTING FORM, SAID CASTING INCLUDING DISPOSING THE ENTIRE FORM AND ASSOCIATED INCOMPRESSIBLE SPACING MEANS AND STRAND CHUCK FOR EACH TENSIONED STRAND IN AN ENVIRONMENT FOR CURING TO ESTABLISH A BOND BETWEEN TENSIONED STRANDS AND CONCRETE, AND AFTER CURING, SEVERING EACH TENSIONED STRAND THROUGH SAID OPEN AREA AT A REGION BETWEEN THE STRAND CHUCK AND SAID ONE END OF THE CASTING FROM WHEREBY SAID STRAND CHUCK IS RE-USABLE AND SAID COOPERATIVELY THREADED MEMBERS MAY BE EASILY TURNED WITH RESPECT TO EACH OTHER FOR DISASSEMBLY.