Pressure-balanced wide web guide roller

Claim 2

A pressure-balanced guide roller assembly adapted for the conveyance of wide webs, comprising in combination: a non-rotaTing, substantially rigid head traverse extending centrally through the entire length of the roller assembly and connected to a frame-support on each end thereof; a plurality of roller segments arranged axially adjacent to one another on the head traverse so as to form an outwardly substantially continuous, generally cylindrical roller assembly for contact with a running web or the like; an independent bearing unit rotatably supporting each roller segment, each bearing unit including a non-rotating sleeve surrounding the head traverse; means for adjustably positioning each bearing unit relative to the head traverse, including means for radially biasing each bearing unit and its roller segment in opposition to the contact pressure exerted by the web against the roller assembly; and means for restraining the adjustment displacements of each bearing unit to motions of the bearing unit center along only a single displacement path within a radial plane.

Claim 3

A guide roller assembly as defined in claim 1, wherein: the adjustment restraining means includes a pivot connection between each bearing unit and the sleeve of the head traverse, the axis of the pivot connection being parallel to the rotational axis of the roller segment and radially spaced with respect thereto in a plane which is substantially at right angles to the direction of contact pressure on the roller assembly; and the biasing means exerts a pivoting moment on the bearing unit about its pivot connection which is opposed to the pivoting moment resulting from the contact pressure.

Claim 4

A guide roller assembly as defined in claim 2, wherein: the pivot connections are arranged on a longitudinal outside face of the head traverse and include for each bearing unit a pivot pin attached to the sleeve of the bearing unit and a pivot block attached to the head traverse.

Claim 5

A guide roller assembly as defined in claim 1, wherein: the adjustment restraining means includes a straight-line guide connection between each bearing unit and the head traverse for reciprocating adjustment motions of the bearing units, the orientation of the straight-line motion path being substantially in alignment with the direction of contact pressure on the roller assembly; and the force exerted on each bearing unit by its biasing means is substantially in opposite alignment with said straight-line motion path.

Claim 6

A guide roller assembly as defined in claim 4, wherein: the straight-line guide connections include parallel straight-line guide rails on the head traverse and cooperating guide members on the bearing units which are laterally oppositely spaced in relation to the bearing unit axis, the straight-line guide rails being arranged on the outside of the head traverse; and the biasing means is arranged between said straight-line guide connections, in general alignment with the straight-line motion path of the bearing unit axis.

Claim 7

A guide roller assembly as defined in claim 4, wherein: the straight-line guide connections include radially inwardly oriented paralled guide plungers which are fixedly attached to the bearing unit sleeves and matching guide sleeves which are solidary with the head traverse, the guide plungers engaging the guide sleeves for reciprocating radial adjustment motion.

Claim 8

A guide roller assembly as defined in claim 6, wherein: the biasing means directly engages the inner ends of the guide plungers.

Claim 9

A guide roller assembly as defined in claim 1, wherein: the biasing means includes a separate, independent bias-producing member for each bearing unit.

Claim 10

A guide roller assembly as defined in claim 1, wherein: the biasing means includes means fo equalizing the biasing forces acting on all the bearing units regardless of their adjustment positions in relation to the head traverse.

Claim 11

A guide roller assembly as defined in claim 9, wherein: the biasing means includes a pressurized fluid pressure medium to whose pressure the bearing units are separately exposed in such a way as to create identical biasing forces on all bearing units.

Claim 12

A guide roller assembly as defined in claim 9, wherein: the biasing means further includes a fluid-filled pressure chamber having flexible wall portions; and the bearing units engage the flexible wall portions of the pressure chamber on contact surfaces of substantially equal effective area.

Claim 13

A guide roller assembly as defined in claim 11, wherein: the adjustment restraining means includes a pivot connection between each bearing unit and the sleeve of the head traverse, the axis of the pivot connection being parallel to the rotational axis of the roller segment and radially spaced with respect thereto in a plane which is substantially at right angles to the direction of contact pressure on the roller assembly; the head traverse is a hollow, tubular member; the pressure chamber of the biasing means is accommodated inside the head traverse; and the bearing units include stems mounted on their sleeves which extend radially toward the inside of the head traverse and against exposed flexible wall portions of the pressure chamber, the effective contact surface defined between each stem and its associated flexible wall portion being located at such a distance and angle in relation to the axis of the associated pivot connection that the plane which is defined by the pivot axis and by the midpoint of the contact surface is substantially perpendicular to the adjustment motion path of the stem at the contact surface.

Claim 14

A guide roller assembly as defined in claim 12, wherein: the pressure chamber is a hose-like flexible pressure cushion which is confined over a major portion of its outer surface within the cavity of the head traverse; and each bearing unit stem includes a rounded head at its inner end with which it engages a wall portion of the pressure cushion, the rounded head defining the effective contact area.

Claim 15

A guide roller assembly as defined in claim 12, wherein: the pressure chamber is constituted primarily of rigid walls, the wall portions in the vicinity of each bearing unit stem being flexible to ensure transmission of the biasing force at the effective contact area and to allow for adjustment displacements of the stem relative to the pressure chamber.

Claim 16

A guide roller assembly as defined in claim 14, wherein: the flexible wall portion in the vicinity of the bearing unit stem is a membrane covering an opening in a rigid wall of the pressure chamber, one side of the membrane being in contact with the pressure medium, the other side bearing against the stem, and the wall opening defining the size of the effective contact area.

Claim 17

A guide roller assembly as defined in claim 14, wherein: the flexible wall in the vicinity of the bearing unit stem is a bellows sealingly attached to an opening in a rigid wall of the pressure chamber, the bottom of the bellows bearing against the stem, and the wall opening defining the size of the effective contact area.

Claim 18

A guide roller assembly as defined in claim 4, wherein: the head traverse is a hollow tubular member; and the biasing means includes a pressurized fluid pressure medium to whose pressure the bearing units are separately exposed in such a way as to create identical biasing forces on all the bearing units.

Claim 19

A guide roller assembly as defined in claim 17, wherein: the straight-line guide connections include radially inwardly oriented parallel guide plungers which are fixedly attached to the sleeves of the bearing units and matching guide sleeves which are solidary with the head traverse, the guide plungers engaging the guide sleeves for reciprocating radial adjustment motion; the biasing means further includes a piston surface on each guide plunger and a cylinder space inside each guide sleeve, the piston surface and cylinder space cooperating in such a way that, when pressurized, they create a biasing force on the beariNg unit which is in opposition to the contact pressure on the roller assembly; and the pressurized fluid pressure medium is in simultaneous communication with all cylinder spaces.

Claim 20

A guide roller assembly as defined in claim 17, wherein: the biasing means further includes a fluid-filled pressure chamber arranged inside the head traverse and having flexible wall portions; and the bearing units include stems mounted on their sleeves which extend radially toward the inside of the head traverse and against exposed flexible wall portions of the pressure chamber, the effective contact surfaces between the stems and the flexible wall portions being substantially identical for each bearing unit.

Claim 21

A guide roller assembly as defined in claim 19, wherein: the pressure chamber is a hose-like flexible pressure cushion which is confined over a major portion of its outer surface within the cavity of the head traverse; the straight-line guide connections include guide sleeves which are solidary with the head traverse, the guide sleeves cooperating with the stems of the bearing units to form said straight-line guide connections; and each bearing unit stem further includes a rounded head at its inner end with which it engages a wall portion of the pressure cushion, the rounded head defining the effective contact area.

Claim 22

A guide roller assembly as defined in claim 19, wherein: the head traverse is a square-tubular hollow member; the pressure chamber is constituted by the cavity of the head traverse itself; the straight-line guide connections are arranged on the outside of the head traverse, on two opposite walls which are parallel to the adjustment motion path; and the head traverse further includes openings on a third wall in concentric alignment with the stems of the bearing units; each opening being covered by a flexible membrane, one side of the membrane being in contact with the pressure medium and the other side bearing against the stem.

Claim 23

A pressure-balanced guide roller assembly adapted for the conveyance of wide webs, comprising in combination: a non-rotating, substantially rigid head traverse extending centrally through the entire length of the roller assembly and connected to a frame-support on each end thereof; a plurality of roller segments arranged axially adjacent to one another on the head traverse so as to form an outwardly substantially continuous, generally cylindrical roller assembly for contact with a running web or the like; an independent bearing unit rotatably supporting each roller segment, each bearing unit including a non-rotating sleeve surrounding the head traverse; means for adjustably positioning each bearing unit relative to the head traverse, including means for radially biasing each bearing unit and its roller segment in opposition to the contact pressure exerted by the web against the roller assembly; and means for restraining the adjustment displacements of each bearing unit to motions within a radial plane; and wherein: the head traverse has a generally cylindrical outer surface; the sleeves of the bearing units have a cylindrical bore forming an annular, longitudinally elongated gap between it and the head traverse; the bearing unit positioning and biasing means includes at least two independent, oppositely arranged fluid-filled arcuate pressure cushions of flexible material extending through the consecutive longitudinal gaps between the bearing unit sleeves and the head traverse so as to support the bearing units by their sleeves, thr pressure cushions being arranged to leave angular intervals between their longitudinal edges; and the displacement restraining means includes guide collars between the bearing units, the guide collars being fixedly connected to the head traverse and arranged to cooperate with the adjacent sleeves of the bearing units in such a way as to prevent said sleeves from rotating relative to the pressure Cushions, while delimiting the adjustment displacements of the bearing units to two degrees of freedom within a radial plane.

Claim 24

A pressure-balanced guide roller assembly adapted for the conveyance of wide webs, comprising in combination: a non-rotating, substantially rigid head traverse extending centrally through the entire length of the roller assembly and connected to a frame-support on each end thereof; a plurality of roller segments arranged axially adjacent to one another on the head traverse so as to form an outwardly substantially continuous, generally cylindrical roller assembly for contact with a running web or the like; an independent bearing unit rotatably supporting each roller segment, each bearing unit including a non-rotating sleeve surrounding the head traverse; means for adjustably positioning each bearing unit relative to the head traverse, including means for radially biasing each bearing unit and its roller segment in opposition to the contact pressure exerted by the web against the roller assembly; and means for restraining the adjustment displacements of each bearing unit to motions within a radial plane; and wherein: the head traverse has a generally cylindrical outer surface; the sleeves of the bearing units have a cylindrical bore forming an annular, longitudinally elongated gap between it and the head traverse; the bearing unit positioning and biasing means includes at least two independent, oppositely arranged fluid-filled arcuate pressure cushions of flexible material extending through the consecutive longitudinal gaps between the bearing unit sleeves and the head traverse so as to support the bearing units by their sleeves, thr pressure cushions being arranged to leave angular intervals between their longitudinal edges; and the displacement restraining means includes guide collars between the bearing units, the guide collars being fixedly connected to the head traverse and arranged to cooperate with the adjacent sleeves of the bearing units in such a way as to prevent said sleeves from rotating relative to the pressure Cushions, while delimiting the adjustment displacements of the bearing units to two degrees of freedom within a radial plane.

Claim 25

A guide roller assembly as defined in claim 22, wherein: the guide collars and the bearing unit sleeves have oppositely facing axially extending guide teeth with which they cooperate to delimit the adjustment displacements of the bearing units.

Claim 26

A guide roller assembly as defined in claim 22, wherein: the displacement restraining means includes means for guiding the bearing unit sleeves in relation to the guide collars so as to limit the adjustment displacements of each bearing unit to a single motion path.

Claim 27

A guide roller assembly as defined in claim 22, wherein: the guide collars are centered on the head traverse in the angular intervals between the arcuate pressure cushions and include arcuate recesses for the accommodation of the latter.

Claim 28

A guide roller assembly as defined in claim 1, wherein: the biasing means includes pressurized fluid pressure medium to whose pressure the bearing units are separately exposed in such a way as to create identical biasing forces on all bearing units; the assembly further comprising: means for selectively compensating the biasing forces on those end bearing units whose roller segments are not contacted by the running web.

Claim 29

A guide roller assembly as defined in claim 26, wherein: the compensating means includes a fluid-filled compensation chamber between the bearing unit sleeve and the head traverse at the side opposite the direction of radial outward-bias on the bearing unit, and means for pressurizing said fluid.

Claim 30

A guide roller assembly as defined in claim 1, further comprising: means for continuously lubricating each bearing unit from an outside supply of lubricant, the lubricating means including a supply conduit running along the outside of the head traverse and branch lines leading to the bearing units.

Claim 31

A guide roller assembly as defined in claim 28, further comprising: flexible peripheral seals between the edges of adjacent roller segments, and sealing bellows at both extremities of the roller assembly so as to substantially enclose the entire interior space inside the roller assembly; the lubricating means including means for supplying pressurized oil to the branch lines, the latter including atomizing nozzles to create a lubricating oil mist inside the roller assembly.

Claim 32

A guide roller assembly as defined in claim 1, further comprising: means for rotatably adjusting the head traverse relative to its frame supports for the purpose of resetting the orientation of the biasing means and of the displacement restraining means in relation to the direction of web pressure on the roller assembly.

Claim 33

A pressure-balanced broad-stretching roller assembly for use in the conveyance of wide webs, comprising in combination: a non-rotating, substantially rigid, gently curving head traverse extending centrally through the entire length of the roller assembly, the curvature of the head traverse being concave in the direction of web advance; swivelling frame supports on each end of the head traverse; means for rotably adjusting the head traverse relative to its frame supports for the purpose of aligning the head traverse curvature in relation to the web direction; a plurality of roller segments arranged axially adjacent to one another on the head traverse so as to form an outwardly substantially continuous, generally cylindrical, but gently curved roller assembly for contact with the running web; an independent bearing unit rotatably supporting each roller segment, each bearing unit including a non-rotating sleeve surrounding the head traverse; means for adjustably positioning each bearing unit relative to the curved head traverse, including means for radially biasing each bearing unit and its roller segment in opposition to the contact pressure exerted by the web against the roller Assembly; and means for restraining the adjustment displacements of each bearing unit to motions within a radial plane.

Claim 34

A pressure-balanced broad-stretching roller assembly for use in the conveyance of wide webs, comprising in combination: a non-rotating, substantially rigid, gently curving head traverse extending centrally through the entire length of the roller assembly, the curvature of the head traverse being concave in the direction of web advance; swivelling frame supports on each end of the head traverse; means for rotably adjusting the head traverse relative to its frame supports for the purpose of aligning the head traverse curvature in relation to the web direction; a plurality of roller segments arranged axially adjacent to one another on the head traverse so as to form an outwardly substantially continuous, generally cylindrical, but gently curved roller assembly for contact with the running web; an independent bearing unit rotatably supporting each roller segment, each bearing unit including a non-rotating sleeve surrounding the head traverse; means for adjustably positioning each bearing unit relative to the curved head traverse, including means for radially biasing each bearing unit and its roller segment in opposition to the contact pressure exerted by the web against the roller Assembly; and means for restraining the adjustment displacements of each bearing unit to motions within a radial plane.

Claim 35

A guide roller assembly as defined in claim 31, wherein: the adjustment restraining means includes means for restraining the adjustment displacements of each bearing unit to motions of the bearing unit center along only a single motion path within said radial plane.