Roll tensioner
AssigneeZIH Corp.
InventorsPhillip Breyer, Douglas L. Harb, Thomas M. Zevin, Alexander Peter
Life of this patent
Estimating the term…
Abstract
An image forming device includes a roll tensioner adapted to hold a medium roll rotatably mounted thereon for providing a printable medium strip to the imaging device. The roll tensioner comprises a torsion mechanism exerting torsion to the printable medium strip that tends to pull back the printable medium strip and, thus, to prevent slack of the printable medium strip, the roll tensioner further including a torsion control mechanism to prevent the torsion from getting too large to stop the rotation of the printable medium roll, the roll tensioner also including a clutch mechanism to prevent damage to the torsion mechanism.
Claims19
A device adapted to be coupled into an imaging device, comprising:
- a tubular sleeve, said sleeve being adapted to rotate bidirectionally;
- a shaft rotatably inserted in said sleeve;
- a first end cap coupled to said shaft at a first end, said first end cap having an inner tunnel adapted to allow said shaft to pass through and having a center section of generally hexagonal shape on outer periphery;
- a second end cap coupled to said shaft at a second end, opposite to the first, said second end cap having an inner tunnel adapted to allow said shaft to pass through and having a center section of generally cylindrical shape on the outer periphery;
- a torsion mechanism positioned in said sleeve and encircling said shaft;
- and
- a slip mechanism positioned in said sleeve and coupled to said torsion mechanism, said slip mechanism being adapted to cause said torsion mechanism to rotate freely in a first rotational direction relative to said tubular sleeve and being adapted to cause said torsion mechanism to resist rotation in a second rotational direction, opposite to the first, until a torsion in the torsion mechanism is increased to reach a predetermined threshold value, said slip mechanism maintaining the torsion of the torsion mechanism at approximately the threshold value when the torsion reaches the threshold value.
The device of claimed 1, wherein said torsion mechanism comprises a coil spring encircling said shaft, said coil spring having a first bent extrusion at a first end coupled to said first end cap.
A device adapted to be coupled into an imaging device, comprising:
- a tubular sleeve, said sleeve being adapted to rotate bidirectionally;
- a shaft rotatably inserted in said sleeve;
- a torsion mechanism positioned in said sleeve and encircling said shaft;
- a slip mechanism positioned in said sleeve and coupled to said torsion mechanism, said slip mechanism being adapted to cause said torsion mechanism to rotate freely in a first rotational direction relative to said tubular sleeve and being adapted to cause said torsion mechanism to resist rotation in a second rotational direction, opposite to the first, until a torsion in the torsion mechanism is increased to reach a predetermined threshold value, said slip mechanism maintaining the torsion of the torsion mechanism at approximately the threshold value when the torsion reaches the threshold value;
- a clutch mechanism coupled to said torsion mechanism and encircling said shaft, said clutch mechanism being adapted to allow said torsion mechanism to rotate freely in the first rotational direction and to resist in the second rotational direction;
- a slip means coupled to said clutch mechanism and affixed to said shaft, said slip means being adapted to prevent the torsion of said torsion mechanism to increase over the threshold value;
- a slip clutch encircling said shaft, said slip clutch being adapted to resist rotation in the second rotational direction and to rotate freely in the first rotational direction;
- and
- a clutch sleeve securely coupled to said torsion mechanism at a first end and encircling said slip clutch, said clutch sleeve being adapted to rotate freely in the first rotational direction and to resist rotation in the second rotational direction by said slip clutch.
A tension system adapted to be incorporated into an imaging device, comprising:
- a support frame adapted to be positioned within the imaging device, said support frame having first and second slots respectively located at opposite ends of said support frame wherein said first slot has a hexagonal contour at its receptive bottom and said second slot has a round contour at its receptive bottom;
- and
- a torsion roller, said torsion roller having first and second end caps wherein a portion of said first end cap has a keyed periphery adapted to be inserted into the first slot and a portion of said second end cap has a round periphery adapted to be inserted into the second slot and the first slot is small enough to not accept the second end cap, said torsion roller being adapted into be rotated freely in a first rotational direction and being adapted to resist rotation in a second rotational direction, opposite to the first, until a torsion within said torsion roller is increased to reach a predetermined threshold value.
A device adapted to be coupled into an imaging device, comprising:
- a tubular sleeve, said sleeve being adapted to rotate bidirectionally;
- a shaft rotatably inserted in said sleeve;
- a torsion mechanism positioned in said sleeve and encircling said shaft;
- and
- a slip means positioned in said sleeve and coupled to said shaft, said slip mechanism being adapted to cause said torsion mechanism to rotate freely in a first rotational direction relative to said tubular sleeve and to resist rotation in a second rotational direction, opposite to the first, until torsion in the torsion mechanism is increased to reach a predetermined threshold value, said slip means maintaining the torsion of the torsion mechanism at approximately the threshold value when the torsion reaches the threshold value and being adapted solely to prevent the torsion of said torsion mechanism from increasing over the threshold value independent of the rate of accumulation of torsion in the torsion mechanism.
Dependencies are inferred from the claim text.