Patent Application
20180036900
The following disclosure relates generally to arbors for circular saws and, more particularly, to arbors for securely attaching saw blades to drive shafts of circular saws and associated systems and methods.
A variety of existing circular saws include a motor-driven, rotatable drive shaft. Typically, a saw blade is removably coupled to the drive shaft via an arbor. The arbor is generally a two-piece device that includes an interior portion and an exterior portion. The interior and exterior portions are positioned on opposite sides of a central hole in the saw blade, with the interior portion positioned between the saw blade and a body of the saw. A bolt can be extended through the exterior and interior portions of the arbor and the central hole in the saw blade, and threaded into the drive shaft to secure the saw blade to the drive shaft. A friction fit or a shaped opening (e.g., a knockout opening) is typically used to reduce slippage between the saw blade and the drive shaft. With a friction fit, the bolt is tightened to drive the interior and exterior portions of the arbor towards each other and press against the blade positioned therebetween. If the bolt is insufficiently tightened and/or if the blade is subjected to significant drag forces, the blade can slip with respect to the drive shaft and the arbor. Slippage of the blade can interrupt cutting operations and/or produce inaccurate or otherwise defective cuts.
With knockout openings, the interior portion of the arbor includes an engagement feature that is positionable within a complimentary-shaped knockout opening in the saw blade. The engagement feature and the knockout opening often have complimentary diamond shapes, and the engagement feature extends outwardly, away from the drive shaft, and into the knockout opening to engage the blade. The engagement feature is generally designed to extend outwardly a distance that is less than or equal to the thickness of the saw blade. The bolt can then drive the interior and exterior portions of the arbor toward each other and against the blade, without the engagement feature contacting the exterior portion and preventing the interior portion and exterior portion from securely contacting the blade. In most cases, the diamond shaped engagement feature and the corresponding knockout opening can help reduce slippage between the blade and the drive shaft. Slippage can still occur, however, if the engagement feature does not stay positively engaged within the blade via the knockout opening. If a relatively thick saw blade is used, for example, the engagement feature may not extend a significant enough depth into the knockout opening. Excessive forces on the blade and/or insufficient tightening of the bolt can then result in movement of the blade that disengages the engagement feature from the knockout opening and results in blade slippage.
The following disclosure describes various embodiments of arbors for circular saws and associated systems and methods. In several embodiments, an arbor includes a coupler and a flange. The coupler can include an interior mounting face and an engagement feature, and the engagement feature can be shaped to extend through an opening in a saw blade. The flange can include an exterior mounting face and a recess, and the recess can be shaped to at least partially receive the engagement feature. The flange and the coupler can be configured to fixedly attach the saw blade to a drive shaft of the circular saw, with the saw blade clamped at least partially between the interior mounting face and the exterior mounting face.
In other embodiments, the arbors described herein and the associated devices, systems and methods can have different configurations, components, and/or procedures. Still other embodiments may eliminate particular features, components and/or procedures. A person of ordinary skill in the relevant art, therefore, will understand that the present technology, which includes associated devices, systems, and procedures, may include other embodiments with additional elements or steps, and/or may include other embodiments without several of the features or steps shown and described below with reference to
As discussed above, existing arbors may not adequately prevent slippage of a saw blade relative to a corresponding drive shaft. The present technology includes several embodiments of arbors and associated systems and methods that have engagement features for significantly reducing or even preventing the opportunity for slippage between a saw blade and the arbor. In some embodiments, such arbors can be referred to as “slipless arbors.” As used herein, the term “slipless arbors” refers to arbors that prevent or significantly reduce opportunities for slippage between an arbor and an associated saw blade. Certain details are set forth in the following description and
In the Figures, identical reference numbers identify identical, or at least generally similar, elements. To facilitate the discussion of any particular element, the most significant digit or digits of any reference number refers to the Figure in which that element is first introduced. For example, element 102 is first introduced and discussed with reference to
In the illustrated embodiment, the coupler bore 108b includes two opposing flat surfaces 112 (only one flat surface 112 visible in
In the illustrated embodiment, the engagement feature 210 extends past the opening 302 in the saw blade 300, such that the saw blade 300 is axially offset from the forward face 211 of the engagement feature (i.e., offset in a direction along an axial axis A). The axial offset between the saw blade 300 and the forward face 211 of the engagement feature 210 can help to prevent the saw blade 300 from moving off of the engagement feature 210, and thereby significantly reduce the opportunity for slippage between the saw blade 300 and the arbor 100. Specifically, when the saw blade 300 is positioned on the coupler 104 with the engagement feature 210 extending through the hexagonal opening 302, the close fit of the hexagonal opening 302 and the hexagonal wall 212 prevents rotation of the saw blade 300 with respect the arbor 100. Absent deformation of the saw blade 300 or the arbor 100, slippage of the saw blade 300 with respect to the arbor 100 is only possible when the engagement feature 210 moves out of the opening 302. The axial offset of the saw blade 300 and the forward face 211 of the engagement feature 210 reduces undesired movement of the engagement feature 210 out of the opening 302, and thereby reduces the opportunity for slippage. In several embodiments, the axial offset between the saw blade 300 and the forward face 211 of the engagement feature 210 can be at least partially dependent on an axial offset between the forward face 211 and the interior mounting face 208. In some embodiments, the axial offset between the forward face 211 and the interior mounting face 208 can be 3 mm. In other embodiments, the axial offset between the forward face 211 and the interior mounting face 208 can be between 1 mm and 5 mm, or between 1 mm and 30 mm.
In addition to eliminating or significantly reducing slippage and providing flush-cut capabilities, arbors configured in accordance with the present technology are expected to reduce or eliminate saw path deflection during cutting operations. When a force is applied to a conventional circular saw to advance the saw along a cutting path, the saw will tend to stray or deflect away from the direction of the force at a slight angle, and thereby deviate from the intended cutting path. Without being bound by any theory or mechanism of action, the inventor believes that the arbor 100 can include dimensions that help to reduce or eliminate such saw path deflection. More particularly, the arbor 100 can be constructed with the gap 106 (
The inventor has determined that particular dimensions of the arbor 100 can position the saw blade 300 at a location that significantly reduces or eliminates saw path deflection. For example, in one embodiment, an axial distance from the shoulder 117 of the coupler 104 to the interior mounting face 208 can be between 20 mm and 35 mm, or about 27.5 mm. The inventor has determined that for particular circular saws, an axial offset of 27.5 mm between the shoulder 117 and the interior mounting face 208 significantly reduces saw path deflection. In other embodiments, the distance between the shoulder 117 and the interior mounting face 208 can be larger or smaller than 27.5 mm. For example, the distance between the shoulder 117 and the interior mounting face can be between 5 mm and 100 mm or between 20 mm and 40 mm.
In some embodiments, other dimensions can determine the proper positioning of a blade to reduce or eliminate saw path deflection. For example, in one embodiment, an axial distance between the interior face 115 of the coupler 104 and the interior mounting face 208 can be 32.5 mm to provide significantly reduced saw path deflection. In other embodiments, the distance between the interior face 115 of the coupler 104 and the interior mounting face 208 can be larger or smaller than 32.5 mm (e.g., between 5 mm and 100 mm or between 25 mm and 45 mm).
The arbor 100 and associated components described herein can be constructed using a variety of materials and manufacturing methods known in the art. For example, the arbor 100 can be machined from metal and/or metal alloy stock materials (e.g., steel or aluminum) via a milling machine, a vertical or horizontal machining center, a multi-tasking machine, or other manufacturing machines and/or tools. In some embodiments, the arbor 100 can be cast formed via metal and/or metal alloys. In other embodiments, the arbor 100 can be formed from plastics, composites, metals and/or other materials via a 3D printer or via other manufacturing methods.
The present technology can include a variety of methods for reducing slippage between an arbor and a circular saw blade. A particular method can include forming an arbor having an engagement feature shaped to extend through an opening in a circular saw blade. Forming the arbor can include forming a coupler that includes the engagement feature, and forming a flange having a recess shaped to receive the engagement feature.
From the foregoing, it will be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the present technology. Those skilled in the art will recognize that numerous modifications or alterations can be made to the components or systems disclosed herein. For example, an embodiment described above included an interior portion or coupler having an engagement feature, and an exterior portion or flange having a recess. In other embodiments, an interior portion or coupler can include a recess and an exterior portion or flange can include an engagement feature shaped to be at least partially received in the recess of the coupler. Moreover, certain aspects of the present technology described in the context of particular embodiments may be combined or eliminated in other embodiments. Furthermore, while advantages associated with certain embodiments have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the present technology. Accordingly, the inventions are not limited except as by the appended claims.
This application claims priority to U.S. Provisional Patent Application No. 62/370,104, entitled “ARBORS FOR CIRCULAR SAWS AND ASSOCIATED SYSTEMS AND METHODS,” filed Aug. 2, 2016, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62370104 | Aug 2016 | US |
