Explosive tendon-tensioning means

Claim 2

An explosive tendon-tensioning means for tensioning a concrete reinforcing tEndon anchored on one end to a body of concrete and having a free end extending through the body of concrete, said tensioning means comprising hollow outer barrel means having an inward end and an outward end and being embedded in said concrete, with said free end of said tendon extending into said inward end of said hollow outer barrel means, tendongripping means within said hollow outer barrel, explosive means within said hollow barrel for exerting a substantial force on said tendon-gripping means for driving said tendon-gripping means outwardly into a tensioned condition and retaining means for retaining said tendon means in tensioned condition following the tensioning thereof by said explosive means.

Claim 3

The invention of claim 1 additionally including shock-absorbing means between said explosive means and said tendon-gripping means for cushioning the force imparted to said tendon-gripping means and said tendon by said explosive means.

Claim 4

The invention of claim 2 wherein said shock-absorbing means comprises a body of soft deformable metal.

Claim 5

The invention of claim 3 wherein said outer barrel means comprises a main cylinder member concentrically oriented with respect to said tendon and having an end cap connected to and covering the inward end of said main cylinder which faces inwardly into said body of concrete with said end cap having an aperture through which said tendon member extends from said body of concrete.

Claim 6

The invention of claim 4 wherein said retaining means includes a plurality of radially apertured discs each of which is in peripheral engagement with a serrated surface on the interior of a cylindrical inner barrel fixedly connected in concentric manner to said main cylinder and has an axial aperture received over the outer surface of an axially positioned tendon guide member of hollow cylindrical configuration having an axial aperture concentrically oriented with respect to said main cylinder through which said tendon extends with said apertured discs being of generally conical configuration so that said discs are easily moved in a first direction by said explosive means as said tendon means is being tensioned but being prevented from movement in an opposite direction by the engagement of its periphery with said serrated surface.

Claim 7

The invention of claim 5 wherein said tendon-gripping means includes a conical segmented wedge clamp member matingly received within a conical opening in a drive block having an inward side and an outward side which is concentrically fitted within the hollow outer barrel with said conical segmented wedge clamp member being defined by a plurality of radially oriented wedge members which are urged toward said tendon by outward movement of said drive block to grip said tendon which extends through an axial passageway in said segmented wedge clamp member.

Claim 8

The invention of claim 6 wherein said tendon guide member includes a radial base flange having an inward face and an outward face with the inward face abutting against the inward side of said end cap and an axially aligned guide tube extending a substantial distance outwardly from said base flange coaxially with respect to said outer barrel means and having an axial passageway through which said tendon extends and wherein said explosive means is located adjacent the outward face of said base flange and additionally including a thrust block with an inward face and an outer face encircling said guide tube with its inward face adjacent said explosive means and having a periphery matchingly received within said inner barrel with the innermost one of said apertured discs being mounted adjacent the outer face of said thrust block, a plunger ring encircling said tubular guide adjacent the outermost one of said discs and having an inward face and an outward face with its outward face engaging said body of soft deformable metal with said body of soft deformable metal encircling said guide tube adjacent the outward side of said plunger ring and engages said drive block on its Inward side.

Claim 9

The invention of claim 1 wherein said tendon-gripping means includes a conical segmented wedge clamp member matingly received within a conical opening in a drive block having an inward side and an outward side which is concentrically fitted within the hollow outer barrel with said conical segmented wedge clamp member being defined by a plurality of radially oriented wedge members which are urged toward said tendon by outward movement of said drive block to grip said tendon which extends through an axial passageway in said segmented wedge clamp member.

Claim 10

The invention of claim 8 wherein said outer barrel means comprises a main cylinder member concentrically oriented with respect to said tendon and having an end cap connected to and covering the inward end of said main cylinder member which faces inwardly into said body of concrete with said end cap having an aperture through which said tendon member extends from said body of concrete.

Claim 11

The invention of claim 9 wherein said retaining means includes a plurality of radially apertured discs each of which is in peripheral engagement with a serrated surface on the interior of a cylindrical inner barrel fixedly connected in concentric manner to said main cylinder and has an axial aperture received over the outer surface of an axially positioned tendon guide member of hollow cylindrical configuration having an axial aperture concentrically oriented with respect to said main cylinder through which said tendon extends with said apertured discs being of generally conical configuration so that said discs are easily moved in a first direction by said explosive means as said tendon means is being tensioned but being prevented from movement in an opposite direction by the engagement of its periphery with said serrated surface.