Metal founding – Means to shape metallic material – Pressure shaping means
Reexamination Certificate
1995-11-13
2001-04-17
Lin, Kuang Y. (Department: 3205)
Metal founding
Means to shape metallic material
Pressure shaping means
C164S119000
Reexamination Certificate
active
06216766
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a device to effect a fluid-tight coupling around a pipe serving to convey molten material, as part of the connection between a low pressure diecasting machine and a pressurizable receptacle in which the molten material is prepared. The device disclosed is well suited for application to a pipe fashioned from fragile material, insertable typically through one wall of the receptacle, which comprises a body having an inlet end that is located internally of the receptacle and a head at the pipe outlet end whose surface can be coupled in fluid-tight association with a mold coupled to the low pressure diecasting machine.
A low pressure diecasting machine of the type in question is mounted on and connected to a receptacle containing molten material in a manner such that the pipe is aligned and connected with the injection nozzles of a mold connected to the machine.
The prior art systems employed in making such a connection, while based on a variety of techniques, are similar inasmuch as all permit removing the machine from the receptacle. In effect, the machine rests on the receptacle during operation and can be moved to a non-operating position whenever the need arises to gain access to the inside of the receptacle. To ensure the features of a removable connection that can be successfully operated, the pressure-tight fit between the nozzles and the front end surface of the head of the pipe is obtained by interposing seals of gaskets of suitable thickness. The efficiency of the sealing action in containing the pressure of the molten material is somewhat critical, given that the tightness of the fit between the front end surface of the pipe and the nozzle of the mold relies only on a suitably strong force of compression.
In practice, this is achieved by packing the space between the machine and the head of the pipe to an overall depth nominally greater than that of the existing gap, so that the fluid-tight barrier will be established by a compressive force provided by the total weight of the low pressure diecasting machine.
Quite apart from the operational inconvenience and the empirical nature of such a system, selection of the optimum condition depends on a process of trial and error. The working principle underlying this method of connection tends to result in a high degree of structural stress on the pipe. In other solutions, the receptacle is forced vertically into association with the diecasting machine through the agency of suitable lifting means, the force in this instance being applied laterally.
Owing to the intense and uncontrollable impact of these stresses, rupture of the pipe frequently occurs, particularly when the pipe, as already intimated, is made of a fragile material, such as silicon nitride or other ceramics typically utilized in the context of low pressure diecasting processes for aluminum alloys.
Conversely, the application of a smaller compressive force to the sealing medium might well diminish the risk of pipe rupture, but would not ensure an efficient sealing action to accommodate the pressure of the fluid flowing at high temperature through the pipe. In short, a solution that succeeds both in avoiding the risk of rupture to the pipe and in ensuring an efficient seal must necessarily involve a compromise between the two opposing requirements outlined above.
OBJECT OF THE INVENTION
Accordingly, the object of the present invention is to overcome the aforementioned drawbacks, providing a solution to the problem of ensuring an efficient sealing action between pipe and mold by adopting a novel arrangement for compressing the interposed sealing medium, and allowing for adjustment of the force by which the sealing action is assured.
SUMMARY OF THE INVENTION
The stated object is realized by a device in which a pipe for conveying molten material can be coupled adjustably and in a pressure-tight fit as part of the connection between a low pressure diecasting machine and a pressurizable receptacle for preparation of the molten material.
The pipe passes through one wall of the receptacle and has a body affording a head coinciding with an outlet end whose front surface can be coupled to the mold of the low pressure diecasting machine together with an interposed sealing medium. The design of the device takes account of the fact that the outer surface of the pipe as supplied by the manufacturer has at least one portion which is angled in relation to the axis of the pipe itself. In a preferred embodiment described below, the outer surface of the pipe comprises a portion of the head that has a substantially frustoconical shape.
The device itself comprises three wedges disposed circumferentially around the pipe between the head and the wall of the receptacle. Each wedge has a surface matched to the aforementioned angled portion of the pipe in such a manner that the surfaces can be coupled together. In addition, the three wedges are mounted slidably on corresponding ways and are thus capable of movement in relation to the wall of the receptacle, transversely to the axis of the pipe through the agency of an actuator means. The movement is brought about between a non-operating at-rest position of the wedges spaced from the pipe, and an operating position of close proximity of the wedges to the pipe in which the wedges apply an axial force such as will tend to draw the pipe outward from the receptacle and, in consequence, cause the head to be clamped together with the sealing medium against the mold of the low pressure diecasting machine. The three wedges are thus able to generate the requisite sealing action, at least across the front end surface of the head, in opposition to the pressure of the molten material flowing along the pipe.
The principal advantage of a device according to the invention is that the optimum clamping force for a given pipe can be determined by a continuous incremental type of adjustment in which the weight of the machine plays no part whatever.
REFERENCES:
patent: 3163897 (1965-01-01), Sylvester
patent: 4995535 (1991-02-01), Ooya et al.
patent: C-1 156 942 (1964-05-01), None
patent: A-53 279 (1967-05-01), None
patent: B-1 508 753 (1969-04-01), None
patent: A-0 379 420 (1990-07-01), None
patent: 573053 (1958-02-01), None
patent: 573054 (1958-02-01), None
patent: 6-114529 (1994-04-01), None
Patent Abstracts of Japan vol. 17 No. 103 (M-1374), Mar. 2, 1993 & JP-A-04 294854 (Toyota Motor) Oct. 19, 1992 *abstract*.
Benni Gianni
Muneratti Giorgio
Darby & Darby
Lin Kuang Y.
Reynolds Wheels International Ltd.
LandOfFree
Fluid-tight coupling device for a feeder pipe does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fluid-tight coupling device for a feeder pipe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluid-tight coupling device for a feeder pipe will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2551611