Patent ID: 7344375
Filing Date: 2008-03-18
Classification: A61C

Abstract:
1. A pushing device for a tooth restoration material mixed and kneaded in a capsule, comprising: a cylindrical piston rod for pushing a tooth restoration material housed in a capsule for a tooth restoration material, the piston rod having a head part and a through hole, where the head part has at least a part, which has a larger outer diameter than an outer diameter of the backward side, at the front end side, and the through hole is provided along the whole length of the piston rod, and having at least more than one slit at a front end thereof and locking through holes provided in a side part at the rear end side thereof, where the locking through holes have a smaller diameter than that of the through hole, reach to the through hole, and are opposed each other; a leak preventive cover having a front end opening part contacted with a rear end part of the capsule for a tooth restoration material to be mounted, a housing part for housing the head part of the piston rod, an inserting hole for inserting a portion at the backward side from the head part of the piston rod slidably in the axial direction at the backward side of the housing part, and a small diameter portion and a large diameter portion on the outer periphery thereof, where the small diameter portion is provided at the front end side, and the large diameter portion is provided at the rear end side; a ratchet body having an upward wall part having a release body inserting part from the frontward side to the backward side at a center part in the width direction, a frontward wall part having a piston rod inserting hole provided for inserting the rear end part of the piston rod, and both side wall parts having a hole for a piston rod fixing pin provided through at the frontward side, and having a rack part for a ratchet formed on a lower edge at the rear side of the hole for a piston rod fixing pin, where the piston rod inserted into the piston rod inserting hole is fixed by a piston rod fixing pin, which is inserted into the both locking through holes of the piston rod, and the both holes for a piston rod fixing pin; a compression coil spring provided along the outer periphery of the piston rod, between a rear face of the leak preventive cover and a front face of the frontward wall part of the ratchet body; a housing body having a mounting part at which the capsule for a tooth restoration material is mounted, a supporting path for slidably inserting the small diameter portion of the leak preventive cover, a guiding path in which the piston rod, the compression coil spring and the ratchet body are provided movably in front and rear directions while contacting to the upward wall part of the ratchet body, a through hole for a lever shaft provided at the both side wall parts at a lower side of the guiding path, a grip part provided at the rear end side of the guiding path, and an opening part for a release body at a position of an upper side of the guiding path, where the position of the opening part for the release body is at least connected to the release body inserting part of the ratchet body when the ratchet body is moved at the most backward side so as to be positioned at an initial position and where the mounting part, the supporting path and the guiding path are provided in this order from a front end toward the back at an upper part of the housing body; a ratchet body locking plate spring, which is for constantly giving force for upwardly pressing the ratchet body so as to prevent movement of the ratchet body in the front and rear directions, and the rear end of the plate spring is fixed at the backward side from the guiding path in the housing body a locking pawl which is at the front of the plate spring is inserted into a root part of the cogs of the rack part for a ratchet of ratchet body; a lever having a lever body rotatably mounted on a lever shaft fixed at the through hole for a lever shaft of the housing body, a torsion spring being provided along the outer periphery of the lever shaft and constantly giving force for downwardly rotating the backward side from the lever shaft of the lever body, and a pressing body having one end part axially supported at the backward side from the lever shaft of the lever body and constantly receiving a force for inserting a pressing pawl formed at another end thereof into the root part of the cogs of the rack part for a ratchet of the ratchet body which is positioned at the frontward side from the locking pawl of the ratchet body locking plate spring, where the force is given by a spring for a pressing body provided between the pressing body and the lever body, and where, when a portion at the backward side from the lever shaft of the lever body is upwardly rotated while resisting against the rotating force given by the torsion spring and the pressing forces given by the compression coil spring and the ratchet body locking plate spring, the pressing pawl of the pressing body frontwardly presses the root part of the cogs of the rack part for a ratchet of the ratchet body so as to frontwardly move the cogs of the rack part for a ratchet body by just one cog, and when the force for upwardly rotating the portion at the backward side from the lever shaft of the lever body is canceled, the pressing pawl of the pressing body is inserted into a root part of the cogs, which is just one cog behind the cogs of the rack part for a ratchet moved by the pressing pawl of the pressing body, so as to return the lever body to the initial position; The release body having a pressing part provided between the both side wall parts of the ratchet body, and a button part which is continuously formed above the pressing part, has a smaller area of a transverse section than an area of a transverse section rectangular to the moving direction of the pressing part, and is projected from the opening part for a release body of the housing body, where, when the button part is downwardly pressed, the pressing part downwardly moves the locking pawl of the ratchet body locking plate spring and the pressing pawl of the pressing body of the lever, which are inserted into the root part of the cogs of the rack part for a ratchet of the ratchet body, so as to cancel the locking state to the rack part for a ratchet; and a stopper means for controlling to stop the ratchet body, which is backwardly moved by the pressing force of the compression coil spring, at the initial position, when the locking state of the locking pawl of the ratchet body locking plate spring and the pressing pawl of the pressing body of the lever to the rack part for a ratchet is canceled by the release body; wherein an auxiliary compression coil spring is provided along the outer peripheries of the leak preventive cover and the compression coil spring, between a front end side of the guiding path of the housing body and the frontward wall part of the ratchet body.