Plastic article or earthenware shaping or treating: apparatus – With safety feature – Secondary means to prevent accidental motion – or means to...
Reexamination Certificate
2001-06-27
2004-01-20
Mackey, James P. (Department: 1722)
Plastic article or earthenware shaping or treating: apparatus
With safety feature
Secondary means to prevent accidental motion, or means to...
C164S153000, C164S342000, C164S347000, C425S556000, C425S593000, C425S444000
Reexamination Certificate
active
06679698
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a die clamping apparatus with an ejecting mechanism for separating molded articles from a die assembly, which may be used for a die-casting machine or a plastic injection molding machine.
2. Description of the Related Art
In an injection molding machine for molding a resin material such as a plastic material, a die clamping apparatus for a die assembly is provided, which die clamping apparatus is provided with an ejector or pushing-out mechanism for detaching a molded article from the die assembly. The die clamping apparatus is for closing and opening a die assembly. At the closed condition by the die clamping apparatus, the die assembly is subjected to a clamping operation at a desired clamping force in the die assembly. The ejector mechanism in the die clamping apparatus is provided with ejector pins, which are selectively projected into a cavity formed by the die assembly. Namely, when the die assembly is opened as the result of a completion of a molding process, the ejector pins are projected into the cavity, thereby causing a finished product to be removed.
In a prior art construction, an ejector pin of an ejecting mechanism and the die are separately operated by different actuators. Thus, the prior art construction is defective in that a construction is complicated and a cost is increased.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a die apparatus capable of overcoming difficulties in the prior art.
Another object of the present invention is to provide a die apparatus capable of obtaining a positive operation of a pushing-out operation in relation to the opening/closing operation of the die clamping apparatus.
According to a first aspect of the invention, a die apparatus is provided, comprising: a stationary die; a stationary die plate on which the stationary die is held; a moving die; a moving die plate on which the moving die is held while the moving die being faced with the stationary die; die clamping means for selectively opening and closing the dies as well as for clamping the dies; at least one pushing-out pin selectively projected from and retracted to the moving die; a movable member connected to the pushing-out pin and arranged movably with respect to the moving die plate, and; means for constraining the movement of the movable member in the die opening and closing directions when the movable member is moved to a predetermined die opening position, such that, with respect to the moving die plate moved further in the die opening direction from the predetermined die opening position or moved in the die closing direction toward the die opening position, only the movement of the movable plate is constrained by the constraining means.
In the operation of the first aspect of the invention, the movement of the movable member connected to the pushing-out pin in the die opening direction is constrained by the constraining means when the moving die plate is moved to the die opening position. A further movement of the moving die plate in the die opening direction from the die opening position allows only the movement of the moving die plate, while the movable member to be kept stopped. As a result, a relative movement is obtained between the movable member and the moving die plate, which cause the pushing-out pin to be projected from the moving die, which causes a product to be separated.
After the completion of the ejection of the product, the moving die plate is returned to the die opening position in the die closing direction. During the movement, the movable member is also constrained by the constraining means. As a result, the pushing-out pin connected to the movable member is retracted to the die surface of the moving die. Namely, in the present invention, a retraction of the pushing-out pin to the moving die is not done by a spring force as is the case in the prior art but is done by the movement of the moving die itself. Thus, a reliable retraction of the pushing-out pin to a predetermined position can be obtained even in a situation where a desired function of a return spring is lost under a reason that molten metal is attached and solidified to the coil spring.
According to a second aspect of the present invention, a die apparatus is provided, which comprises: a stationary die; a stationary die plate on which the stationary die is held; a moving die; a moving die plate on which the moving die is held while the moving die being faced with the stationary die; die clamping means for selectively opening and closing the dies as well as for clamping the dies; at least one pushing-out pin selectively projected from and retracted to the moving die; a movable member connected to the pushing-out pin and arranged movably with respect to the moving die plate; means for constraining the movement of the movable member in the die opening and closing directions when the movable member is moved to a predetermined die opening position, such that, with respect to the moving die plate moved further in the die opening direction from the predetermined die opening position, only the movement of the movable plate is constrained by the constraining means, thereby generating a resultant relative movement between the movable member and the moving die plate, so that the pushing-out pin is projected from the moving die, which causes a molded product to be pushed out, and; means for preventing the moving die plate from being moved at least in the forward direction from the die opening position after the completion of the pushing-out operation for a separation of a molded product so long as the constraining operation by the constraining means is maintained.
In this second aspect of the invention, the die clamping means comprise a link housing and drive means arranged between the link housing and the moving die plate for generating a die clamping force, and wherein the constraining means constrains the movable member with respect to the to the link housing.
In the second aspect of the invention, the constraining means comprise an actuator mounted on one of the link housing and the moving die plate for causing the link housing and the moving die plate to be engaged with each other.
In the operation of the second aspect of the invention, the movement of the movable member connected to the pushing-out pin in the die opening direction is constrained by the constraining means when the moving die plate is moved to the die opening position. A further movement of the moving die plate in the die opening direction from the die opening position allows only the movement of the moving die plate, while the movable member to be kept stopped. As a result, a relative movement is obtained between the movable member and the moving die plate, which cause the pushing-out pin to be projected from the moving die, which causes a product to be separated from the moving die.
When the moving die plate is in the die opening position, the movable member is constrained by the constraining means and the moving die plate is prevented from being moved with respect to the movable member from the home position in the die closing direction, so that the moving die plate is prevented from being moved from the die closing direction from the die opening direction so long as the constraining means is operated. Thus, the present invention can function as a safety mechanism which prevents the die apparatus from being accidentally closed.
According to a third aspect of the present invention, a die apparatus is provided, which comprises: a stationary die; a stationary die plate on which the stationary die is held; a moving die; a moving die plate on which the moving die is held while the moving die being faced with the stationary die; die clamping means for selectively opening and closing the dies as well as for clamping the dies; at least one pushing-out pin selectively projected from and retracted to the moving die; a movable member connected to the pushing-out pin and arranged movably with respect to the moving die pl
Abe Yuji
Ishibashi Hiroshi
Tsuji Makoto
Yokoyama Hiroshi
Mackey James P.
Pillsbury & Winthrop LLP
Toshiba Kikai Kabushiki Kaisha
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