1. A liquid droplet-jetting apparatus which jets a droplet of a liquid, the liquid droplet-jetting apparatus comprising:
a flow passage unit which includes a plurality of pressure chambers arranged along a plane, a plurality of nozzles communicated with the pressure chambers, respectively, and a common liquid chamber communicated with the pressure chambers; and
an energy-applying mechanism which applies discharge energy to the liquid in the pressure chambers, wherein the common liquid chamber includes:
an inflow port into which the liquid to be supplied to the pressure chambers is inflowed;
a main portion which extends in a first direction;
a connecting portion which has an end connected to one end of the main portion, which extends in a second direction, and which has a cross-sectional area, in a direction perpendicular to the second direction, smaller than a cross-sectional area of the main portion in a direction perpendicular to the first direction; and
an extended portion which has an end connected to the other end of the connecting portion on a side opposite to the main portion, which extends in a third direction, and which has a cross-sectional area, in a direction perpendicular to the third direction, greater than the cross-sectional area of the connecting portion;
wherein the pressure chambers are arranged in the first direction;
wherein the main portion has a substantially constant cross-sectional area in the direction perpendicular to the first direction; and
wherein the inflow port is provided on the main portion at an area on a side opposite to the connecting portion, with the pressure chambers being intervened between the inflow port and the connecting portion.
2. The liquid droplet-jetting apparatus according to claim 1;
wherein the common liquid chamber is defined by a wall surface of the flow passage unit, and a portion, of the wall surface, which defines the connecting portion of the common liquid chamber, protrudes as compared with portions, of the wall surface, which define the main portion and the extended portion, respectively.
3. The liquid droplet-jetting apparatus according to claim 1;
wherein the flow passage unit further includes a bridge which has both ends held by a wall surface, of the flow passage unit, defining the common liquid chamber; and the connecting portion is defined by the bridge and the wall surface.
4. The liquid droplet-jetting apparatus according to claim 1;
wherein the cross-sectional area of the extended portion is 12 to 13 times the cross-sectional area of the connecting portion.
5. The liquid droplet-jetting apparatus according to claim 1;
wherein the cross-sectional area of the extended portion is greater than the cross-sectional area of the main portion.
6. The liquid droplet-jetting apparatus according to claim 1;
wherein the connecting portion includes a plurality of connecting sub-portions; the extended portion includes a plurality of extended sub-portions; and the connecting sub-portion and the extended sub-portions are alternately formed in the first direction.
7. The liquid droplet-jetting apparatus according to claim 1;
wherein the common liquid chamber includes a first liquid chamber and a second liquid chamber;
wherein the main portion, the connecting portion and the extended portion are provided on each of the first and second liquid chambers; and
wherein the flow passage unit further includes a linking portion which links an end, of the extended portion belonging to the first liquid chamber, on a side opposite to the connecting portion and an end, of the extended portion belonging to the second liquid chamber, on a side opposite to the connecting portion.
8. The liquid droplet-jetting apparatus according to claim 7;
wherein the linking portion extends in a fourth direction, and a cross-sectional area of the linking portion in a direction perpendicular to the fourth direction is greater than the cross-sectional area of the extended portion.
9. The liquid droplet-jetting apparatus according to claim 1;
wherein the energy-applying mechanism includes a piezoelectric layer which faces the pressure chambers, and a pair of electrodes which apply an electric field to the piezoelectric layer to change a volume of the pressure chambers.
10. The liquid droplet-jetting apparatus according to claim 9;
wherein the piezoelectric layer includes a plurality of individual piezoelectric layers which are stacked in a multilayered form.
11. The liquid droplet-jetting apparatus according to claim 1;
wherein a gap is formed in the flow passage unit at an area which overlaps with the common liquid chamber and which is located on a side opposite to the pressure chambers in a direction perpendicular to the plane.
12. An ink-jet printer which performs recording on a recording medium by jetting liquid droplets of an ink, the ink-jet printer comprising:
an ink-jet head including a flow passage unit which includes a plurality of pressure chambers arranged along a plane, a plurality of nozzles communicated with the pressure chambers respectively, and a common liquid chamber communicated with the pressure chambers;
and an energy-applying mechanism which applies discharge energy to the ink in the pressure chambers; and
a transport mechanism which transports the recording medium in a predetermined direction, wherein the common liquid chamber includes:
an inflow port into which the liquid to be supplied to the pressure chambers is inflowed;
a main portion which extends in a first direction;
a connecting portion which has an end connected to one end of the main portion, which extends in a second direction, and which has a cross-sectional area, in a direction perpendicular to the second direction, smaller than a cross-sectional area of the main portion in a direction perpendicular to the first direction; and
an extended portion which has an end connected to the other end, of the connecting portion, on a side opposite to the main portion, which extends in a third direction, and which has a cross-sectional area, in a direction perpendicular to the third direction, greater than the cross-sectional area of the connecting portion;
wherein the pressure chambers are arranged in the first direction, the main portion has a substantially constant cross-sectional area in the direction perpendicular to the first direction, and the inflow port is provided on the main portion on a side opposite to the connecting portion, with the pressure chambers being intervened between the inflow port and the connecting portion.
13. The ink-jet printer according to claim 12; further comprising;
a carriage which is movable in a direction intersecting the predetermined direction with the ink-jet head placed thereon.
14. The ink-jet printer according to claim 13;
wherein the cross-sectional area of the extended portion is greater than the cross-sectional area of the main portion.
15. The ink-jet printer according to claim 13;
wherein the connecting portion has a plurality of connecting sub-portions; the extended portion has a plurality of extended sub portions; and the connecting sub-portions and the extended sub-portions are alternately formed in the first direction.
16. The ink-jet printer according to claim 12;
wherein the common liquid chamber is defined by a wall surface of the flow passage unit, and a portion, of the wall surface, which defines the connecting portion of the common liquid chamber, protrudes as compared with portions of the wall surface which define the main portion and the extended portion, respectively.
17. The ink-jet printer according to claim 12;
wherein the flow passage unit further includes a bridge which has both ends held by a wall surface, of the flow passage unit, defining the common liquid chamber, and the connecting portion is defined by the bridge and the wall surface.
18. The ink-jet printer according to claim 12;
wherein the cross-sectional area of the extended portion is 12 to 13 times the cross-sectional area of the connecting portion.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Apparatus for producing wood chips that includes:
a rotatable disc having a series of spaced apart radially extended slots passing between a front face and a rear face of said disc;
a primary chipper knife mounted along a radial wall of each slot at the entrance to said each slot for slicing chips from a wooden work piece that is placed in contact with the front face of said disc and directing said chips into said each of said slots;
a counter knife unit mounted within each of said slots behind said primary chipper knife;
said counter knife unit further including a first series of chip contact elements each having a first height for initially engaging chips leaving said primary chipper knife to reduce the size of said chips;
said counter knife unit further including a second series of chip contact elements each having a second height that is less than the height of said first chip contact elements and being arranged to engage said chips leaving said first series of contact elements to further reduce the size of said chips.
2. The apparatus of claim 1 wherein each chip contact element contains a linear blade for engaging chips as said chips move through said slots to reduce the size of said chips.
3. The apparatus of claim 2 wherein said blades are inclined toward the direction of rotation of said disc.
4. The apparatus of claim 3 wherein each blade contains a linear cutting edge that is generally aligned along the longitudinal axis of each slot.
5. The apparatus of claim 3 wherein each blade contains a linear cutting edge that is offset from the longitudinal axis of each slot at an angle of between 0\xb0 and 20\xb0.
6. The apparatus of claim 2 wherein the first and second series of chip contact elements are integrally attached to a common base.
7. The apparatus of claim 6 wherein each of the chip contact elements in said second series are situated between a pair of chip contact elements in said first series.
8. The apparatus of claim 7 wherein each of said chip contact elements in said second series is arranged to contact chips leaving said first series of chip contact elements about midway along the width of the chips leaving said first series of contact elements.
9. The apparatus of claim 2 wherein said chip contact elements of said first series are mounted upon a first base and said chip contact elements in said second series of contact elements are mounted upon a second base.
10. The apparatus of claim 9 wherein said second base is mounted in contact with said first base.
11. The apparatus of claim 1 that further includes a third series of chip contact elements each having a third height that is less than said second height of the chip contact elements in said second series of chip contact elements and which are arranged to engage chips leaving said second series of chip contact elements to further reduce the size of said chips.
12. The apparatus of claim 11 wherein each of the chip contact elements in said third series is situated between one of the chip contact elements in said second series and one of the chip contact elements in said first series.
13. A method of producing wood chips within a wood chipping machine having a rotatable disc that contains radially disposed slots that pass through said disc, said method including the steps of:
mounting a primary knife at the entrance of each slot for separating chips from work pieces that are brought into contact with said rotating disc and directing said chips through said slot;
mounting counter knife unit within each slot downstream from said primary knife;
providing said counter knife unit with a first series of chips contact elements for engaging the chips slices leaving said primary knife to reduce the size of said chips;
providing said counter knife unit with a second series of chip contact elements for engaging chips leaving the said first series of contact elements to further reduce the size of said chips.