Cutting Head

This disclosure relates generally to a waterjet cutting system. More specifically, the disclosure relates to a cutting head that utilizes water for cutting operations.

Waterjet cutting systems utilize a cutting head with precisely aligned components through which water may be combined with abrasives to form a cutting stream. An intensifier or high pressure pump supplies a pressurized stream of water to the cutting head. The stream of water passes through an orifice to form a focused stream of water. Simultaneously, abrasive particles may be metered into a feeding tube that supplies the abrasive particles to a wear insert of the cutting head. The abrasive particles are drawn into the wear insert by a venturi vacuum that occurs due to the stream of water flowing through the wear insert, such that the stream of water accelerates the abrasive particles through the wear insert. The accelerated abrasive particles, along with the water stream, exit the focusing tube as a cutting stream traveling at high speed. The cutting stream is configured to cut a material, and although a catcher is utilized, expended abrasive particles may be transferred to exposed components of the waterjet cutting system and surroundings in the form of dust. This dust contamination can create fitment issues with components of the cutting head. Such issues cause misalignment of the components in the cutting head such that alignment of the focusing orifice of the focusing tube with the orifice is not possible, and, therefore, the cutting stream flowing therein unevenly strikes a surface of the focusing orifice causing uneven wear and an unpredictable cutting stream.

Fitment issues of the components of the cutting head may also occur due to a tolerance stack introduced by the components of the cutting head. The components of the cutting head in the prior art include a collet that slides onto a focusing tube such that a collet nut is able to be threaded over the collet and the focusing tube and onto a cutting head body into which the focusing tube extends and through which a focusing orifice extends in alignment with an orifice of the cutting head body. A tight tolerance, or allowable variation, of each of the components is required to avoid the fitment issues, and controlling the tolerance of each component minimizes the tolerance stack that may affect the alignment of the focusing orifice with the orifice. Because such tight tolerances are required for proper functioning of the cutting head, it is desired that the tolerance stack be minimized and that contaminants that might affect the alignment of the cutting head be minimized.

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the invention will be apparent from the following detailed description of the embodiments and the accompanying drawing figures.

The embodiments described herein relate to a cutting head that includes a cutting head body with an integrated collet. A wear insert secured within the cutting head body is flow connected to an orifice through which a focused stream of water flows and a feed tube through which abrasive particles are metered. The abrasive particles are drawn into a venturi chamber of the wear insert by the focused stream of water that flows therethrough. The stream of water accelerates the abrasive particles being metered into the venturi chamber toward and through a focusing tube secured by the integrated collet. The integrated collet aligns the orifice with a focusing orifice of the focusing tube. A nut is configured to secure the integrated collet to the focusing tube and to seal an interior of the cutting head body.

The drawing figures do not limit the invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.

The following detailed description references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized, and changes can be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the invention is defined only by the appended claims, along with the full scope of the equivalents to which such claims are entitled.

In this description, references to “one embodiment,” “an embodiment,” or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment,” “an embodiment,” or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments but is not necessarily included. Thus, the technology can include a variety of combinations and/or integrations of the embodiments described herein.

An embodiment of a cutting headshown infor use in an abrasive waterjet cutting system is described herein. The cutting headincludes a cutting head bodywith an integrated colletthat is formed integral with the cutting head bodyand that is configured for setting and maintaining an alignment of the components of the cutting head. The integrated colletis configured to secure a nozzle or focusing tubewithin the cutting head bodysuch that a cutting stream formed by accelerated abrasive particles and a high speed water stream advances through the focusing tubeduring a cutting operation. Alignment of components during assembly of the cutting headis required to ensure a consistent cutting stream and to minimize wear of the components of the cutting head, including the focusing tube, due to a high speed and high pressure of the stream of water and abrasive through the cutting head.

Integration of the integrated colletwith the cutting head bodydecreases a tolerance stack of the cutting headby reducing the number of components of the cutting head, eliminating a level of tolerance stack-up inherent in the prior art. The reduction in components and decrease in the tolerance stack of the cutting headpermits an overall tolerance requirement to be achieved when the cutting headis assembled such that the cutting headmeets functional requirements. The integrated colletalso facilitates initial alignment and repeatability of the alignment of the components during reassembly of the cutting headafter the cutting headhas been disassembled, such as for cleaning or repair.

A stream of water that has been pressurized by an intensifier and/or pump is supplied to the cutting headthrough tubing formed to accommodate high pressures. The stream of water passes through an orificein the cutting head body. The orificeprovides a constricted section such that a velocity of the stream of water is increased as it passes through the orificeand forms a focused stream of water. As shown in, the water orificeis provided at a rearward endof the cutting head. The stream of water flows through the orificeand into a wear insertthat is secured within the cutting head bodyby a securing screw. The wear insertis in flow communication with the focusing tube.

An abrasive feed tubeis secured to the cutting head bodyand provides a metered flow of abrasive to the cutting head. The abrasive is supplied to the feed tubefrom a hopper by a hose having a friction fitting that is securable to the feed tube. In an embodiment, the feed tubeincludes screw threads at an end thereof for securing the feed tubeto the cutting head body. A sealing ringmay be provided between the feed tubeand the cutting head bodysuch that contaminants, including, for example, water, abrasive, and abrasive and cut material dust, are prevented from entering an interior of the cutting head bodyor getting between components of the cutting head.

A venturi chamberof the wear insert, which may also be referred to a mixing chamber, is positioned between the orificefrom which the stream of water flows and the focusing tubefrom which a cutting stream is discharged. The stream of water exits the orificeand flows through the wear insert. The feed tubeis secured to the cutting head bodysuch that the abrasive is fed into the venturi chamberof the wear insert. Speed of the stream of water through the wear insertcreates a venturi vacuum that draws the abrasive into the wear insert. The abrasive particles are accelerated to, at, or near the speed of the water stream within the venturi chamber and exit into the focusing tubewith the stream of water.

The focusing tubeextends through the integrated colletsuch that the focusing tubeis secured in alignment with the wear insert. The focusing tubeincludes a focusing orificethat is aligned with the orificesuch that the cutting stream is precisely focused as it flows through the focusing tube. Misalignment, contamination, or other imperfections affect a quality of the cutting stream, a quality of a cut in a material, and a speed of deterioration of, at least, the focusing tube.

The focusing tubeis removably secured within the integrated colletof the cutting head body. The integrated colletis a collar that extends from and is integral with the cutting head bodyand secures the focusing orificeof the focusing tubein alignment with the orifice. The integrated colletfacilitates repeatable alignment of the focusing orificeof the focusing tubewith the orifice. The cutting head bodywith the integrated colletincludes at least two radial surfaces, an interior cylindrical surfacehaving an interior diameter approximately equal to or slightly greater than an exterior diameter of the focusing tubeand an exterior surfacethat is tapered toward a forward end(see) of the cutting head bodyand may have one or more grooves and/or slots or serrations (not shown) that extend parallel to a longitudinal axis of the focusing tube. The focusing tubeis insertable in the forward endof the integrated colletand extends therefrom. In an embodiment, the integrated colletuniformly and centrally secures the focusing tubesuch that the focusing tubedoes not move within the integrated collet, and, in an embodiment, does not move at least laterally within the integrated collet. In an embodiment shown in, the integrated colletincludes longitudinal serrations (not shown) that extend parallel to the longitudinal axis of the focusing tube, such that when the beveled nutis tightened therearound, as described herein, the beveled nutengages the serrations causing the integrated colletto clamp down on the focusing tube.

In, the exterior surface of the cutting head bodyincludes a first surfacethat is able to form a seal with beveled nut, a second surfacethat extends parallel to the longitudinal axis of the focusing tube, and a third surfacethat extends toward and may gradually narrow or taper toward the forward endand forms the integrated collet. The second surfacepreferably includes threads (not shown) formed therearound, and the beveled nutis threadingly securable to the second surfaceof the cutting head bodyto secure the cutting head bodyaround the focusing tubeand/or to seal the interior of the cutting headfrom contaminants.

The beveled nutincludes an interior radial surface that mates with the exterior surface of the cutting head bodyand the integrated collet. In, the interior radial surface includes a shoulder or flangethat is formed on and extends from the beveled nutto sealingly secure the beveled nutaround the first surfaceof the cutting head body, a threaded portionthat includes threads (not shown) and is threadingly securable onto the second surfaceof the cutting head body, and a locking portionthat applies pressure to the third surfacethat forms the integrated collet. The threaded portionof the beveled nutthreadingly engages the second surfaceof the cutting head body. The locking portionapplies pressure to the integrated colletwhen the beveled nutis threaded onto second surfaceof the cutting head bodysuch that the integrated colletis compressible to apply a uniform clamping pressure to the focusing tubeto secure it in a central, aligned position.

One or more sealing ringssecured in one or more groovesthat extend in the exterior surface of the cutting head bodyand/or in the beveled nutprevent contaminants from entering an interior of the cutting head, such as, for example, in between the threads of the beveled nutand the threads of the cutting head body, on the interior cylindrical surfaceof the cutting head body, or between other components of the cutting head. Prevention of such exposure to contaminants in the cutting headmaintains the alignment of the focusing orificeto the orificeand facilitates repeatability of the alignment. In an embodiment shown in, the sealing ringextends in the groovearound the first surfaceof the exterior surface of the cutting head body. In an embodiment, the beveled nutis in covering relationship with at least the first surface, the second surface, and the third surfaceof the cutting head body. In an embodiment, the beveled nutis in covering relationship with the one or more sealing ringsthat extend around the cutting head body.

The cutting head bodywith the integrated collet, the beveled nut, and the one or more sealing ringsare securement features that secure the focusing tubesuch that the focusing orificeis in alignment with orifice, and a cutting steam from the focusing tubeaccurately and precisely forms a cut in a material. These securement features prevent the focusing tubefrom becoming misaligned or from moving during use and/or align the focusing tubewhen assembled. Alignment of the focusing tubeincludes alignment of the focusing orificewith the orifice. Providing such alignment minimizes wear, and especially uneven wear, of the focusing tube. Misalignment of the focusing orificeand the orificecauses the cutting stream to impact a surface of the focusing orificecausing uneven wear of the focusing tube, an imprecise cutting stream, and an inaccurate cut. The securement features also enable robotic applications, including robotic replacement of the focusing tubeand robotic use of the cutting headdue to the precision and repeatable accuracy of assembly and reassembly of the cutting head.

As shown in, an abrasive shieldis secured to the focusing tubeby a set screw. The abrasive shieldmay be flat or be in a shape of a cone such that a concave portion of the cone is directed toward the discharge or forward or cutting endof the cutting headto redirect the expended abrasive particles away from the beveled nut, preventing possible contamination of the interior of the cutting head. The focusing tubeextends through a base or collarsecured to the middle of the abrasive shieldand the set screwsecures the baseto the focusing tube. The abrasive shieldmay be selectively positioned along a length of the focusing tubeto optimize shielding.

Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present disclosure. Embodiments of the present disclosure have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present disclosure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims.