Mechanical blanket clamp in rotating head assembly

A press apparatus for use in a papermaking machine, comprising:

• a backing roll rotatably mounted to a machine frame;
• an elongated nip shoe fixed to the machine frame and having a concave surface which is urged against the backing roll to define a nip with the backing roll to engage a paper web between the nip shoe and the backing roll;
• a blanket which extends through the nip such that the web is disposed between the blanket and the backing roll;
• a first head and a second head rotatably mounted to the frame on either side of the shoe;
• a clamp ring mounted to at least the first head, wherein the clamp ring is slidable on the first head to move axially along the first head, and wherein the clamp ring has an outwardly facing inclined surface;
• a plurality of clamp wedge segments mounted to the first head and radially positionable with respect to the first head, each clamp wedge segment having an inwardly facing inclined surface which engages with the outwardly facing inclined surface of the clamp ring;
• a head ring fixed to the first head and having portions disposed radially outwardly of the clamp wedge segments;
• and
• means for advancing the clamp ring axially with respect to the first head to engage the plurality of clamp wedges and drive portions of the clamp wedges radially outwardly to engage the blanket against the head ring, and thereby clamp the blanket to the first head.

A press apparatus comprising:

• a rotatably mounted backing roll;
• an elongated concave shoe, the shoe being urged toward the backing, roll to define an extended nip therebetween for the passage therethrough of a paper web;
• a blanket defining an endless loop, wherein the blanket extends through the nip such that the web is disposed between the blanket and the backing roll, the blanket having a first lateral edge and a second lateral edge spaced in the cross machine direction from the first lateral edge;
• at least one head mounted for rotation about an axis with respect to the shoe;
• a clamp ring mounted on the head for axial displacement thereon;
• portions of the clamp ring which define a wedge surface facing outwardly from the head;
• a plurality of wedge segments engaged with the clamp ring wedge surface, wherein each wedge segment has an inclined surface which engages with the clamp ring wedge surface such that axial displacement of the clamp ring with respect to the head causes the simultaneous radial displacement of all wedge segments;
• a generally cylindrical head ring which is substantially coaxial with the head and which has portions which encircle the wedge segments, and which is fixed to the head, wherein portions of the blanket extend between the wedge segments and the head ring, and wherein the clamp ring is selectably positionable to alternatively cause the wedge segments to fixedly clamp the blanket to the head, and to release the blanket from engagement with the head for removal from the apparatus;
• means for advancing the clamp ring axially with respect to the head to engage the plurality of clamp wedges and drive portions of the clamp wedges radially outwardly to engage the blanket against the head ring, and thereby clamp the blanket to the head;
• and
• means for forming a seal between the clamped blanket and the clamp ring, the means for forming a seal being independent of and spaced from the wedge segments.

A press apparatus comprising:

• a rotatably mounted backing roll;
• an elongated concave shoe, the shoe being urged toward the backing roll to define an extended nip therebetween for the passage therethrough of a paper web;
• a blanket defining an endless loop, wherein the blanket extends through the nip such that the web is disposed between the blanket and the backing roll, the blanket having a first lateral edge and a second lateral edge spaced in the cross machine direction from the first lateral edge;
• at least one head mounted for rotation about an axis with respect to the shoe;
• a clamp ring mounted on the head for axial displacement thereon;
• portions of the clamp ring which define a wedge surface facing outwardly from the head;
• a plurality of wedge segments engaged with the clamp ring wedge surface, wherein each wedge segment has an inclined surface which engages with the clamp ring wedge surface such that axial displacement of the clamp ring with respect to the head causes the simultaneous radial displacement of all wedge segments;
• a generally cylindrical head ring which is substantially coaxial with the head and which has portions which encircle the wedge segments, and which is fixed to the head, wherein portions of the blanket extend between the wedge segments and the head ring, and wherein the clamp ring is selectably positionable to alternatively cause the wedge segments to fixedly clamp the blanket to the head, and to release the blanket from engagement with the head for removal from the apparatus;
• a plurality of pistons which are connected to the head and which extend axially, wherein the clamp ring is engaged with the pistons, and wherein introduction of fluid between the clamp ring and the pistons serves to drive the clamp ring axially with respect to the head to engage the plurality of clamp wedges and drive portions of the clamp wedges radially outwardly to engage the blanket against the head ring, and thereby clamp the blanket to the head;
• and
• an inflatable seal which extends between the clamped blanket and the clamp ring, the seal serving to retain pressure within the blanket, and wherein loss of the seal does not affect the clamping of the blanket to the heads.