Hydraulic tightening-up device for very high stresses

Claim 2

A hydraulic tightening-up device for connecting together two plate elements or the like initially in contact one to the other, but which undergoes working stresses which tend to move one away from the other, said device comprising a rod passing through said first and second plates having at one of its ends an enlarged head which engages the outer surface of the second plate, at the other end of said rod is mounted a cap which abuts against the outer surface of the first plate through an interposed device having a variable volume, said variable volume device including a substantially sealed annular chamber defined by said rod and two flexible annular walls substantially perpendicular to the rod axis, said walls being sealed closed at their radial outer peripheral edges one to another and can be strained at least in the direction of the axis of said rod by an inner pressurized fluid, means being provided for supplying said pressurized fluid into said chamber which is connected to a fluid source so that contact between the two plates is due to the direct effect of the application of the fluid pressure, which one of said two flexible walls of said chamber transmits directly to the outer surface of the first plate while the other fiexible wall of said chamber transmits the effect of the fluid pressure to said cap and which through this latter pressure causes the tensioning of said rod which in turn causes its head to press against the outer surface of the second plate.

Claim 3

A hydraulic tightening-up device according to claim 1, wherein the working length of the rod is such as to maintain the two plates in contact prior to the application of the working stresses, with the variable volume device in place, the parts of the device being proportioned to provide a pre-tensioning at least equal to the maximum of the working stresses acting to move the plates away from each other and thus break the contact.

Claim 4

A hydraulic tightening-up device according to claim 1, wherein the annular chamber is defined by two annular flexible diaphragms having corrugated walls, one of said flexible diaphragms abutting against the inner surface of the cap and the other against the outer surface of the first plate, the surface portions of the cap and of the first plate, which abut said two diaphragms respectively, being shaped in such a manner as to match with the outer surfaces of said flexible corrugated walls, locking means being provided and arranged along the radial outer peripheral edges of said two annular diaphragms in order to seal the edges of the diaphragms together.

Claim 5

A hydrAulic tightening-up device for connecting together two plate elements or the like initially in contact one to the other, but which undergoes working stresses which tend to move one away from the other, said device comprising a rod passing through said first and second plates having at one of its ends an enlarged head which engages the outer surface of the second plate, at the other end of said rod is mounted a cap constituted of an upper and a lower part, of which the lower part abuts against the outer surface of the first plate, interposed between said upper and lower part of said cap is a device having a variable volume, said variable volume device including a substantially sealed annular chamber defined by said rod and two flexible annular walls substantially perpendicular to the rod axis and sealingly connected at their radial outer peripheral edges and which can be strained at least in the direction of the axis of said rod by an inner pressurized fluid, means being provided for supplying said pressurized fluid into said chamber which is connected to a fluid source so that contact between the two plates is due to the effect of the application of the fluid pressure, which one of said two flexible walls of said chamber through the lower part of the cap transmits the effect of the fluid pressure directly to the outer surface of the first plate while the other flexible wall of said chamber transmits the effect of the fluid pressure through the upper part of said cap and through this latter pressure causes the tensioning of said rod which in turn causes its head to press against the outer surface of the second plate.

Claim 6

A hydrAulic tightening-up device for connecting together two plate elements or the like initially in contact one to the other, but which undergoes working stresses which tend to move one away from the other, said device comprising a rod passing through said first and second plates having at one of its ends an enlarged head which engages the outer surface of the second plate, at the other end of said rod is mounted a cap constituted of an upper and a lower part, of which the lower part abuts against the outer surface of the first plate, interposed between said upper and lower part of said cap is a device having a variable volume, said variable volume device including a substantially sealed annular chamber defined by said rod and two flexible annular walls substantially perpendicular to the rod axis and sealingly connected at their radial outer peripheral edges and which can be strained at least in the direction of the axis of said rod by an inner pressurized fluid, means being provided for supplying said pressurized fluid into said chamber which is connected to a fluid source so that contact between the two plates is due to the effect of the application of the fluid pressure, which one of said two flexible walls of said chamber through the lower part of the cap transmits the effect of the fluid pressure directly to the outer surface of the first plate while the other flexible wall of said chamber transmits the effect of the fluid pressure through the upper part of said cap and through this latter pressure causes the tensioning of said rod which in turn causes its head to press against the outer surface of the second plate.

Claim 7

A hydraulic tightening-up device according to claim 4 wherein the annular chamber is defined by two annular flexible diaphragms having corrugated walls, one of said flexible diaphragms abutting against the upper part of the cap and the other against the lower part of the cap which in turn abuts against the outer surface of the first plate, the surface portions of the cap which abut said two diaphragms respectively being shaped in such a manner as to match with the other surfaces of said flexible corrugated walls, locking means being provided and arranged along the outer and inner peripheral edges of said two annular diaphragms in order to seal the edges of the diaphragms together.

Claim 8

A hydraulic tightening-up device according to claim 5, wherein the radial outer peripheral edges of the annular flexible diaphragms are connected one to the other with the interposition of a lock washer and the outer peripheral edges are locked to the body of the first plate by a plurality of screws with the interposition of an annular member provided to evenly distribute the pressure along said edges.

Claim 9

A hydraulic tightening-up device according to claim 4, wherein the body of the rod has a substantially axial hole, said hole communicating with at least one radial conduit leading to the annular chamber formed between the two diaphragms near their centre orifice, said axial conduit being connected to a pipe feeding the pressurized fluid through a pipe union, said feeding pipe being associated with stop and control means.