Abstract: The present invention relates to a method of producing a sheet metal gear in which a metal sheet (2) is used as a starting material and a gear is formed in the outer peripheral edge of the metal sheet. The object of the production method is to finish easily and accurately pitches of valleys and peaks of the gear which is formed in a simple production facility. The time period required for completing the formation of the gear in the outer peripheral edge of the metal sheet is shortened, thereby enhancing productivity. According to the production method, in the initial preparation step, a number of places of the outer peripheral edge of the circular metal sheet (2) which are arranged with a regular pitch are punched out in the axial direction, thereby forming preliminary valleys and preliminary peaks. Then, the method transfers to a gear forming step.

Abstract: In an ink tank, a main ink chamber is contiguous to a sub ink chamber containing an absorption member, and an air communication hole is formed on the top of the sub ink chamber. The absorption member holds ink pressure constant by capillary attraction of the absorption member. First, ink in the sub ink chamber is consumed with consumption of ink. When ink is consumed in a predetermined amount, air passes through the absorption member and a meniscus forming portion to form bubbles, which then move to the main ink chamber. Ink pressure is held constant by surface tension of the meniscus forming portion. Even if ink remains in a small amount, the ink leading portion makes the meniscus forming portion wet for holding ink pressure.

Abstract: In an ink tank, there are provided a main ink chamber containing a capillary vessel member, and an intermediate ink chamber. When the ink is consumed, the ink held by capillary force of a capillary vessel member is supplied via a communication port from a joint port. The same amount of air as the amount of the consumed ink is conducted from the atmospheric communication port into the main ink chamber. The conducted ink is supplied via a groove formed in a lid to an upper surface of the capillary vessel member. As a result, the air is entered into the capillary vessel member under better condition. In a plane portion of the lid, the ink is in contact with only the capillary vessel member, and the ink remaining this portion is reduced. Thus, the ink using efficiency is increased.

Abstract: A main ink chamber with a through-hole contains a capillary member. An intermediate ink chamber is provided on the side wall of the main ink chamber. A path communicatively interconnects the main ink chamber and the intermediate ink chamber. A second meniscus forming member is disposed in a joint port, to thereby prevent ink leakage. In a print mode, ink flows from the main ink chamber to the joint port, through a meniscus forming member that is disposed in the through-hole. Air bubbles mingled into the ink move along the slanting upper wall of the path by their buoyant force, and are accumulatively stored in the upper part of the intermediate ink chamber. When ink is reduced to zero in the main ink chamber, air bubbles are introduced into the intermediate ink chamber through the meniscus forming member. As a result, the liquid level of the intermediate ink chamber is quickly reduced, thereby indicating a state that ink is used up.

Abstract: An ink supply device for supplying ink to a print head, the device containing a main ink chamber, an intermediate ink chamber, a first meniscus forming member with pores between the main and intermediate ink chambers and a joint portion between the first meniscus forming member and the print head. The ink supply device holds ink by negative pressure maintained therein and extends the efficiency of the ink supply device. Preferably, the intermediate ink chamber is hermetically sealed.

Abstract: Considering the differential pressure .DELTA.P between pressures applied to both faces of a meniscus formation member, the differential pressure .DELTA.P becomes the maximum when an ink supply unit is left standing with the meniscus formation member placed upward. At this time, water head PH of ink attempting to fall due to gravity is applied to the inner face of the meniscus formation member in the same direction as negative pressure PR of a capillary member. Thus, the differential pressure .DELTA.P becomes .DELTA.P=PR+PH. The bubble point pressure PB of the meniscus formation member is set greater than the maximum value of the differential pressure, .DELTA.P=PR+PH, whereby air does not enter an ink tank through the meniscus formation member.

Abstract: An ink supply device for use in an ink jet printer comprising a main ink chamber in communication through a communication hole with a sub-ink chamber containing an ink absorbing member therein. A meniscus film forming member covering the communication hole and communicating the main ink chamber with the sub-ink chamber; the member having a first surface facing the interior of the main ink chamber and an opposite second surface. An ink guide member extending into a lower portion of the main chamber and also being in contact with the first surface of the film forming member, wherein as ink in the main ink chamber is consumed a differential pressure between the first and second surfaces of the film forming member causes a gradual expansion of a liquid meniscus film into an air bubble on the film forming member to maintain a constant negative pressure in the main ink chamber.

Abstract: The present invention relates a method of producing a sheet metal poly-V groove pulley in which a thickened annular peripheral wall of an outer peripheral side of a base plate is holding held and pressed so as to increase the axial length of the annular peripheral wall, thereby forming a drum wall and preliminary ears projected from the root portion of the drum wall, and thereafter a step of forming poly-V grooves and ears is performed so that poly-V grooves and ears which are obtained by further projecting the preliminary ears and have a single layer structure are formed on the drum wall. According to this method, the preliminary ears are previously formed and then further projected so as to form the ears. Even when a sheet metal member is thin, therefore, ears of a single-layer structure which has a sufficient projection degree can be obtained.

Abstract: Ink-jet recording apparatus to reduce the change of the pressure of ink in the inside of ink discharge nozzles in an ink-jet recording apparatus as well as to improve the efficiency of use of ink. In the condition where an ink tank is used in an ink-jet recording apparatus, an ink joint provided in the lower end portion of the ink tank communicates with ink discharge nozzles of a head tip. Upon reception of air pressure from above, ink kept by a porous ink keeper stored in the inside of the ink tank is permitted to be supplied to the head tip. The ink tank is formed so that the internal volume of the ink tank increases in order from the lower portion to the upper portion. Accordingly, when the initial residual quantity of ink is relatively large, the change of the pressure (negative pressure) of ink in the inside of the head tip as caused by consumption of ink can be reduced.

Abstract: The present invention is adapted to form, at the center of a plate-like metallic blank, a case-like boss projecting from one lateral side of the blank, by: curving the plate-like metallic blank such that the blank is convex punching a hole in the top of the curved blank: and bending an arcuate portion of the blank between an outer peripheral edge portion and a hole peripheral portion of the blank in the direction opposite to the convex direction thereof with the outer peripheral edge portion of the blank restrained from extending radially outwardly. Thus, the method of the present invention is adapted to form, with the use of a small press machine, a boss having a sufficient thickness and a sufficient projecting height even though the boss has a small inner diameter, without the thickness of the initial material reduced so much in the course of the production steps.

Abstract: To form a seal ring groove in the outer peripheral surface of a steel plate having a circular contour, the present invention provides a method of producing fluid-chamber component elements by which the peripheral portion of the steel plate held by and between a pair of rotary molds is thickened with the use of a roller before the seal ring groove is formed. According to the method of the present invention, a preliminary thickened portion is first formed at the peripheral portion of the steel plate. Then, there is formed, at the outer peripheral surface of the steel plate, a final thickened portion having such a thickness that the seal ring groove can be formed therein. This prevents the steel plate from being buckling by a pushing force applied by a roller at the time when forming the final thickened portion.

Abstract: The invention presents a manufacturing method of making poly-V pulleys for bending the peripheral end part of the disc-shaped sheet metal blank in concave or convex form, flattening the bent portion so as not to elongate it in the radial direction, increasing the thickness of the peripheral end part of the disc-shaped sheet metal blank, forming the thickened sheet metal blank into a cup form, and forming poly-V grooves at the outer side of the peripheral wall of the cup-shaped blank, and the products thereof. By increasing the thickness of the part corresponding to the peripheral wall of the cup-shaped blank in the stage of the disc-shaped sheet metal blank, the peripheral wall of the cup-shaped blank may be increased in thickness by a simple press machine and at high efficiency.

Abstract: The invention relates to a sheet metal made poly-V pulley in which poly-V grooves (10) to be engaged with poly-V belt are formed in the outer circumference of peripheral wall (5) of a cup-shaped blank (3) integrally forming the peripheral wall (5) extending in the direction orthogonal to the bottom wall (6) at the end part of the bottom wall (6), and annular ears (7, 9) of single layer projecting outward in the radial direction for preventing dislocation of the poly-V belt are formed at both ends of the peripheral wall (5), wherein the end part inner surface side of the bottom wall (6) side of the peripheral wall (5) is bulged inward in the radial direction when forming the ears (7) or before forming the ears (7) to thicken the bottom wall side end part of the peripheral wall, and hence the wall thickness of the bottom wall (6) side end part of the peripheral wall (6) is maintained even when a thin cup-shaped blank (3) is used, so that the problems of the strength, material cost and weight increase may be sol