This invention relates to crimping machines for radially crimping or contracting the socket of a hose fitting onto the end of a hose and more particularly to a crimping die assembly for use in such crimping machines.
In the production of hose assemblies, it is common to permanently secure a hose fitting onto the end of a hose by deforming or crimping an outer socket of the fitting around the hose end to compress the hose end between the socket and a fitting nipple positioned inside the hose bore. To accomplish the crimping, it is a common practice to utilize a circular array of pie-shaped die segments to physically engage the fitting socket and reduce the socket in diameter, thereby securing the fitting to the hose end.
In the art of hose crimping, a common practice is to utilize a rigid die cage assembly to fix the die segments in a circular array. A die cage assembly is advantageous because it aligns the die segments for proper interaction with a die plate and facilitates ease of use by allowing the crimp machine operator to handle one assembly instead of several individual die segments. A conventional die cage assembly provides a further advantage of maintaining the die segments in a spaced apart position prior to the crimping operation to allow insertion of a hose fitting into a central axial bore between the die segments. The insertion is typically accomplished by incorporating a spring positioned between the die cage and the die segments, which is used to force the segments radially outward to enlarge the central bore.
Conventional crimping machines typically employ an engagement mechanism for receiving a die cage assembly. Once received within the crimping machine, the central bore of the die segments may be reduced by actuating a hydraulic ram to drive the die cage assembly into a die plate. The die segments typically have a radially outer conical cam surface that engages a frusto-conical bore of the die plate as the die cage assembly is driven into the die plate. The engagement of the die plate and the die segments converts the axial movement of the die cage assembly into radial contraction of the die segments by the camming action of the conical outer surface of the die segments against the bore of the die plate. The camming affect reduces the central bore of the die segments, thereby engaging and reducing the diameter of the fitting socket and securing the fitting to the hose end.
A further advantage of a die cage assembly is that it allows the crimp machine operator to easily interchange assemblies. The die cage assembly can be readily removed from the engagement mechanism on a crimping machine and replaced with another assembly containing a different array of die segments. Therefore, one crimp machine may be employed to crimp several different hose and fitting combinations over a broad range of diameters.
While the use of a die cage assembly offers several advantages, such as ease of handling and interchangeability, it also has undesirable limitations. One key limitation is that only fittings that have a terminal end capable of passing through the relatively small central bore between the die segments may be crimped in a conventional die cage assembly. Thus, such a limitation prevents a fitting having a terminal end in the shape of a large elbow from passing through the central bore of the die segments.
The present invention is directed to a hinged die cage assembly that allows an upper plate assembly to pivot about a lower plate assembly. When the upper plate assembly is pivoted to an xe2x80x9copenxe2x80x9d position, large elbow hose fittings are permitted to pass through the central bore of the die segments.
In accordance with an embodiment of the present invention, a die cage assembly is provided that includes an upper plate assembly and a lower plate assembly. The upper plate assembly includes an upper back plate attached to an upper front plate by a first plurality of fasteners. The lower plate assembly includes a lower back plate attached to a lower front plate by a second plurality of fasteners. The upper back plate and lower back plate cooperate to form a first hinge portion and the upper front plate cooperates with the lower front plate to form a second hinge portion. The first hinge portion and second hinge portion are joined such that the upper plate assembly is able to pivot about the lower plate assembly at the first and second hinge portions. The upper and lower plate assemblies are adapted to receive a plurality of die segments for radially inwardly crimping a fitting onto an end of a hose.
The present invention is advantageous because it allows passage of large elbow hose fittings that would not pass through the central bore of the die segments in a conventional die cage. The invention is further advantageous because it achieves the aforementioned result without destroying the integrity of a conventional die cage assembly.