Water Jet

Cutting head for a water jet cutting assembly

Water Jet Abstract
An improved cutting head for a water jet cutting assembly utilizing water or other liquid medium at ultra high pressure, with the cutting head including an assembly with an elongated body having a central bore along its axis and including a delivery nozzle at the distal end of the assembly. Alignment of the components is maintained by incorporating a process of manufacture which utilizes the formation of a single bore extending through the body so as to both form and maintain axial alignment of the components. The arrangement is further characterized by having mating surfaces which are free of gaskets or other packing material, thereby establishing, maintaining, and preserving proper axial alignment of components.

Water Jet Claims
What is claimed is:

1. A cutting head for a water jet cutting assembly comprising, in combination:

(a) an elongated body having a central axis, a main bore coaxial with said central axis, a counterbore having a flat annular surface at the base thereof, an inlet adjacent said counterbore along with an outlet disposed in opposed relationship to said inlet, and a mixing chamber interposed between said inlet and outlet;

(b) a jeweled orifice assembly including a mounting shoulder mounted upon said flat annular surface, said jeweled orifice assembly comprising a cylindrical body with a flanged head and a jewel receiving cavity within said flanged head and positioned coaxially with said main bore for mounting a jeweled orifice adjacent said inlet, a flow channel formed within said jeweled orifice assembly and extending from said assembly toward said outlet and arranged coaxially with said main bore;

(c) the flanged head of said jeweled orifice assembly having an undersurface in planar mating relationship with said flat annular surface;

(d) an inlet adaptor positioned coaxially within said counterbore and having a flanged forward head disposed in opposed relationship to said jeweled orifice assembly and with the said flanged forward head having a planar surface in mating contact with the outer surface of the flanged head of said jeweled orifice assembly;

(e) the bore within said body adjacent said outlet having a nozzle member retained therewithin, the nozzle member having a bore formed concentrically therethrough for receiving a flow of water from the bore of said jeweled orifice assembly, and means for retaining said nozzle member coaxially within said main bore, said retaining means including mating conically configured threaded surfaces.

2. The cutting head for a water jet cutting assembly as defined in claim 1 being particularly characterized in that a mixing chamber is positioned within said body, said mixing chamber being enclosed within a cylindrical insert member having a "T" bore formed therewithin, and with the mixing chamber being disposed adjacent the intersection of the leg and cross bore segments of said "T", and with the leg segment of said "T" bore being adapted to receive a charge of abrasive for introduction into said mixing chamber.

3. The cutting head for a water jet cutting assembly as defined in claim 2 being particularly characterized in that means are provided for orienting the position of said cross bore segment within said body.

4. The cutting head for a water jet cutting assembly as defined in claim 1 being particularly characterized in that means are provided for forcibly retaining said jeweled orifice assembly against the surface of said adaptor to form a seal zone between mating surfaces of said jeweled orifice assembly and said inlet adaptor and between the mating surfaces of the jeweled orifice assembly and said cross bore segment.

5. The cutting head for a water jet cutting assembly as defined in claim 1 being particularly characterized in that the outlet of said body is disposed along a conically shaped distal tip portion of said body.

Water Jet Description
FIELD OF THE INVENTION

The present invention relates generally to an improved system for fluid jet cutting machines having cutting heads for producing a high velocity fluid jet for penetrating and cutting through a workpiece. More specifically, the present invention relates to such a cutting head having means for introducing an abrasive particulate material into the flow, and additionally is configured in a manner permitting ease of assembly and alignment of the flow channel as it extends through the cutting head, including that portion of the flow passing through the abrasive mixing chamber.

Water jet cutting machines are widely used for operation in cutting and/or forming patterns in metallic, glass, ceramic, and other materials. Water jet cutting systems and machines have particular utility in connection with articles fabricated or formed of materials having brittle or poor mechanical properties. Additionally, water jet cutting systems have been found highly useful in connection with the formation of intricate or complex patterns without the creation of burrs or other anomalies requiring post-cutting treatment. As such, water jet cutting systems are highly useful in a wide variety of applications.

In connection with the cutting head portion of the system, a number of such devices have been known in the past. Among these are that device disclosed in Chalmers U.S. Pat. No. 5,018,670, commonly assigned, and the substance of which patent is hereby incorporated by reference.

In order to facilitate ease of assembly and alignment of the cutting head, the present invention is provided with components having configurations which simplify alignment of the components of the flow channel through the cutting head, and furthermore simplify the formation of seals between mating surfaces of individual components.

With the system of the present invention, a cutting head is provided which creates a water jet into which a suspension of abrasive particulate material has been introduced. Introduction of abrasive materials increases the rate at which workpieces may be cut and finished. For example, fluid jet cutting systems employ pumps characterized as intensifiers which increase the pressure of water in the system to the ultra-high level, such as in the range of 60,000 psi. This high pressure water is forced through a jewel nozzle having a small orifice therein in order to generate a jet flow of high velocity. The abrasive materials are added to the flow downstream from the orifice in a mixing chamber, at which point the abrasive material is entrained into the flow stream of the water jet. Upon leaving the mixing chamber, the flow stream enters and passes through a nozzle from which the abrasive-ladened flow exits the system. The nozzle assists in directing the jet along its path toward the workpiece.

In order to extend the lifetime of the individual components, it is essential that the components through which the flow forming the water jet passes be in proper axial alignment. Component misalignment can result in damage to the bores, and such damage is typically immediate and extensive. Accordingly, it is important that alignment be facilitated and maintained.

The formation of seals between mating surfaces of components is also of importance. In the past, various added components are utilized to create seals. In the present invention, however, mating surfaces are provided which are machined to an appropriate tolerance so that the surfaces are capable of withstanding the forces imposed by the ultra high pressure water, and hence seals are formed without the necessity of added components such as "O"-rings and the like.

In order to create the initial alignment which is readily maintained, the body of the cutting head is bored axially from end-to-end, specifically from the inlet end to the outlet end. A counterbore is formed adjacent the inlet end, with the base of the counterbore forming a shoulder surface. This shoulder surface assists in aligning a jeweled seat assembly therewithin, and the presence of the elongated bore through the body assures appropriate alignment of the components along the axis of the bore so formed.

SUMMARY OF THE INVENTION

In accordance with the present invention, a cutting head is provided for a water jet cutting system or assembly, with the cutting head comprising an elongated body having an axially extending main bore therethrough, along with a counterbore extending through a portion of the length of the elongated body. An inlet is adjacent one end of the counterbore, with an outlet being provided at the opposed end of the body. A mixing chamber is interposed between the inlet and outlet ends, and a jeweled seat assembly is mounted on the shoulder formed at the base of the counterbore. The jeweled seat assembly comprises a cylindrical body with a flanged head, and having a bore extending therethrough. A jewel receiving cavity is formed in the head of the jeweled seat assembly, with the underside of the head of the jewel seat assembly forming a seal with the base of the counterbore. The flow channel is formed by the jewel, and extends through the body, passing through the mixing chamber from which abrasive particulate may be introduced into the flow. A nozzle is mounted within the bore of the body, with the nozzle having a flow receiving bore arranged coaxially therewithin, with the nozzle being ultimately retained within the bore formed through the body. In this arrangement, therefore, the individual components are assembled in such a way that effective seals are provided along mating surfaces, and furthermore the fabrication techniques employed facilitate ease of both initial alignment and means for retaining alignment of components forming the flow channel formed by the jeweled orifice and extending through the entire assembly including the nozzle discharge tip.

Therefore, it is a primary object of the present invention to provide an improved water jet cutting head having components formed and configured in a fashion which facilitates ease of alignment during assembly, and with the alignment being effectively retained.

It is a further object of the present invention to provide an improved water jet cutting head having components designed and configured to preserve axial alignment over extended periods of time, with the cutting head being further provided with a mixing chamber permitting the effective introduction of abrasive particulate into the flow.

Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawings.