BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:
FIG. 1 is a schematic three-dimensional view showing a typical flute and the tone holes associated therewith;
FIG. 2A is a schematic side view showing the formation of pre-opening holes drilled in a flute body;
FIG. 2B is a schematic cross-sectional view showing how a pulling ball is used to form a tone hole in a flute body in accordance with the prior art;
FIG. 2C is a schematic view showing how a tone hole has now been formed using the pulling ball shown in FIG. 2B;
FIG. 3A is a schematic cross-sectional view showing how the pre-opening holes are formed in a flute body in accordance with the subject invention;
FIG. 3B is a schematic cross-sectional view showing how a pre-forming tool is used to form a tone hole approximation in accordance with the subject invention;
FIG. 3C is a schematic view showing a tone hole approximation now formed in the flute body;
FIG. 3D is a schematic view showing how the forming tool of the subject invention is used to form the completed tone hole;
FIG. 3E is a schematic view showing a tone hole now formed in the flute body;
FIG. 4 is a schematic three-dimensional front view showing a preferred embodiment of a tone hole forming tool in accordance with the subject invention;
FIG. 5 is a schematic cross-sectional view of the tone hole forming tool shown in FIG. 4; and
FIG. 6 is a schematic cross-sectional view showing the distal end of the forming tool shown in FIGS. 4 and 5.
DETAILED DESCRIPTION OF THE INVENTION
Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.
FIG. 1 shows flute 10 with tone holes 5a-5c. The configuration of tone holes 5a-5c is critical for high quality flutes. In the prior art, a CNC machine is used to drill pre-opening holes 12a-12d, FIG. 2A in flute body 10. The holes could also be punched. Flute body 10 is then removed from the CNC machine and taken to an extrusion station. There, an arbor (not shown) is placed in flute body 10 and pulling ball 14, FIG. 2B is placed in the flute body through open end 16. Chimney 19 is used as a forming die. Shaft 18 is then threaded onto pulling ball 14 through hole 12a in flute body 10 and shaft 18 is connected to a press machine which then rotates pulling ball 14 and urges it out of the flute body to form tone hole 5a, FIG. 2C. The remainder of the tone holes are formed in the same way with pulling balls individually pulled up through pre-opening holes 12b, 12c and 12d. Next, the flute body is returned to the CNC machine where the tops of all the tone holes are machined (“faced”) to render them level. Finally, the edges of the tone holes are rolled outwardly to finish them.
Thus, forming tone holes requires the use of different machinery, different jigs and fixtures, and different tools resulting in a time consuming and costly process. Also, since the configuration of the tone holes is critical, there is the possibility of inaccuracies and dimensions which do not meet specifications each time the flute body is moved, fitted with a different arbor, and/or loaded into a machine or press.
In one preferred embodiment in accordance with the subject invention, the primary tone hole forming operations all take place in a CNC machine. Arbor 22, FIG. 3A is placed in flute body 10 and loaded into a CNC machine where endmill 24 is used to form the pre-openings 12a and the like in the flute body. The chip drops down into the hollow arbor and does not interfere with subsequent operations. Next, pre-forming tool 26, FIG. 3B in combination with die (“chimney”) 28 is used to form tone hole approximation 5a′, FIG. 3C. The side wall 30 of tone hole approximation 5a′ is not yet true and the opening 32 may be 0.045″ or more too small (e.g., 0.510″ in diameter). Next, forming tool 40, FIG. 3D is inserted into the flute body transversely into the flute body through tone hole approximation 5a with the distal end 42 of forming tool 40 in its contracted configuration and ball bearings 44a, 44b recessed. Then, forming tool 40 is reconfigured into its expanded configuration with ball bearings 44a, 44b driven outward and forming tool 40 is withdrawn (e.g., rotated and pulled) out of body 10 through chimney 28 to form tone hole 5a, FIG. 3E now with true side wall 30 and opening 32 both meeting the specified tolerances (e.g., opening 32 is now 0.555″ in diameter). In the same manner, all the tone holes are so formed within the same CNC machine using the same forming tool for forming some tone holes and different diameter forming tools of the same basic configuration for forming other tone holes. After withdrawing chimney 28, finishing work, such as machining the top of a tone holes (facing) and rolling the edges of the tone holes, can also take place in the same CNC machine.
The preferred tone hole forming tool includes shaft 50, FIGS. 4-6 with distal end 52 to be inserted transversely into the body of a musical instrument as discussed above. Distal end 52 includes sockets 53 (see FIG. 6) spaced about its periphery (e.g., 4 or 5 sockets) and ball bearings 44a, 44b, and the like mounted in the sockets. Shaft or plunger 54 is movable within body 50 (either by mechanical action or pneumatically, for example) in order to contract and expand the bearings. As shown more clearly in FIG. 5, shaft 54 includes reduced diameter distal portion 60 which may be continuous in the form of a groove extending circumferentially around the distal end of shaft 54 or, instead, may be discrete spaced pockets for receiving the bearings. In either case, when shaft 54 is in the position shown in FIG. 6, ball bearings 44a, 44b are driven outward from the periphery of body 50 rendering the distal end 52 of body 50 the proper size of the resulting tone hole (e.g., in the example above, 0.555″ in diameter). When shaft 54 is moved either mechanically or pneumatically in the direction of arrow 70, FIG. 6, ball bearings 44a, 44b are free to retract into groove 60 rendering them flush, or nearly flush, with the periphery of body 50 allowing 0.500″ diameter body 50 to be inserted into a tone hole approximation (see FIG. 3D). When shaft 54 is then moved opposite the direction of arrow 70, ball bearings 44a, 44b are driven outward from the periphery of the shaft to form the tone hole as body 50 is rotated and pulled out of the flute body.
Typically, all the components of tool 40, FIG. 4 are made of metal (e.g. hardened steel). In one example, to form one exemplary tone hole, body 50 had an outer diameter of 0.500″, an inner diameter of 0.250″, shaft 54 had an outer diameter of 0.250″, and ball bearings 44 had a diameter of 0.156″. The dimensions in the example above, however, are exemplary only and different diameter tools can be used to form different diameter tone holes. Also, the bearings used need not be round and instead could be cylindrical in shape, cone shaped, or configured in other shapes.
The result is a robust tool useful in a CNC machine where, according to one preferred embodiment of this invention, most or even all of the steps associated with forming tone holes can take place. Note that in accordance with the prior art, FIG. 2B, a pulling ball 14 had to be manually inserted into the open end of flute body 10, screwed on the shaft 18, pulled out, removed from shaft 18, and reinserted in the flute body 10, and then re-attached to shaft 18 four times to produce four tone holes. In accordance with the subject invention, in contrast, all the tools shown in FIGS. 3A-3E including forming tool 40, FIG. 3D can be automatically retrieved and used by a properly programmed CNC machine. The result is a serious labor and cost savings.
In the prior art, forming a tone hole cannot take place in one machine because, when the holes are drilled, the chips would fall directly on the pulling ball beneath the hole. The chips would then interfere with the quality formation of a tone hole. In the subject invention, the chips fall into hollow arbor 22, FIG. 3A. Since performing tool 26, FIG. 3B comes from the outside instead of the inside, the chips never interfere with the quality formation of the tone hole. Also, chimney 19, FIG. 2B typically gets in the way of facing and rolling. In the subject invention, chimney 28, FIG. 3 is removable while the flute and arbor remain in the existing setup, thus allowing facing and rolling to be accomplished in the same setup as hole piercing and tone hole extrusion. Generally, though not necessarily, rolling requires that the extruded tone hole be allowed to “float” in order for the rolling tool to be exactly centered in the extruded tone hole. Floating is desirable because the rolling operation is extremely sensitive to the slightest off centering and because, when the rolling setup is different than the extrusion setup, the center is likely to be slightly off. Better quality tone holes are produced by the tool of this invention because there is relatively more spinning force and less extrusion force than in the prior art. In addition, the spinning force is achieved by rotating ball bearings 44 washed in coolant, as opposed to the prior art where a fixed pulling ball with a lubricant was employed. It is believed a process which favors spinning forces over extrusion forces produces a higher quality surface finish on the inside of the tone hole, as well as less distortion to the flute tube surrounding the extruded tone hole due to the gentler, less stressful technique. One other consideration with regard to quality is that a fixed pulling ball tends to “load up” with dust or grit coming off the inside of the tone hole being extruded. This build up of metal dust starts to interfere with subsequent pulls, and thus requires the fixed pulling ball to be regularly cleaned, often manually. Using the process of this invention, there is much less metal dust build up since the ball bearings rotate freely, and whatever dust does build up is cleansed by the flood coolant of the CNC.
Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The invention applies to musical instruments other than flutes, for example. The words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments. Other embodiments will occur to those skilled in the art and are within the following claims.
In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant can not be expected to describe certain insubstantial substitutes for any claim element amended.
Patent Application
20080083315
