Patent Application
20150298273
269/315, 269/318, 83/468.8, 144/253.1, 29/592,
This invention relates to jigs and fixtures for the purposes of positioning and repositioning a workpiece in woodworking and metalworking applications—specifically concerning assemblies commonly referred to as a work-stops. This invention principally applies to the use of radial chop saws, though there are legitimate applications in milling, routing, and other similar activities.
The woodworking and metalworking industries utilize cutting stations—equipment which often is comprised of a rotating saw blade that is moved or moves in relation to a work piece in order to cut or grind material—and often use jigs in order to enhance the effectiveness of these cutting stations. In particular, jigs that are meant to act as contact boundaries for material that is to be cut—henceforth referred to as “stops” or work-stops—are employed to correctly position material meant for modification activities (i.e. cutting, shaping, paring, scoring, grinding and the like). The market does not supply a channel-based work stop for cutting stations that is equally suited for metalworking and woodworking applications while remaining pragmatic, economical, and modifiable for the contemporary operator.
Channel-based work-stop assemblies can be characterized as work-stops which use a rail or track system to allow for proper alignment and mobility of the work-stop in relation to the modifying instrument (i.e. cutting or shaping equipment or tools), and can be classified into three principal types: flip-away, indexable or index-based, and hybrid-style work-stops. Flip-away systems are able to be temporarily removed from the material work piece plane, which is often accomplished through a “flipping” movement of axial rotation away from the material work-piece plane (as in patent no. U.S. Pat. No. 7,798,187 B1). Flip-away systems allow for quick and relatively easy operation, but are often criticized for imprecision and can suffer from excessive pliability. Indexable systems (such as those in U.S. Pat. No. 3,994,484 A or U.S. Pat. No. 2,618,300 A) are able to be indexed to specific coordinate. Indexable systems are often rigid and remain consistent through multiple cutting operations, but their design forces them to remain in the material work-piece plane for as long as a coordinate is to be kept. Hybrid-style work-stops (such as in U.S. Pat. No. 5,337,641) employ elements of the previous work-stop types in order to benefit from the advantages of both. Unfortunately, many hybrid-style stops also propagate the drawbacks of the aforementioned work-stop types: without employing impedimenta, most channel-based work-stops can realistically offer either speed, precision, or a compromise between the two. Those few hybrid-style stops that claim to offer both factors without adding superfluous actions or mechanical complications are often expensive and complex.
The invention improves upon existing hybrid-style work-stops and jigs by employing a basic yet novel design which affords more than a compromise between speed and precision. Illustrations and explanations herein will detail how the invention employs the desirable features of aforementioned channel-based flip-away and indexable work-stop types, while minimizing the drawbacks of these. Furthermore, the invention supports this claim through a system design that need be neither prohibitively expensive nor overly convoluted, and can be readily modified in order to comply with different specifications. These and advantages of the invention will be apparent from the forthcoming description and drawings.
Note: The inventor requests that the patent application be not limited to the dimensions given hereafter; any specific dimensions of certain items are included in order to assist with the understanding of the present invention and the edification of the patent application. It is impractical to establish a single standard for all cutting stations, as requirements may vary widely from station to station (indeed, this fact is one of the reasons for the present invention's design in the first place). It is for these reasons that while some specific attributes are given in the following descriptions and parts list, some items are not specifically sized.
The preferred embodiment of the present invention is an assembly that attaches to a rail [20] made from strut channel (such as the design proposed in U.S. Pat. No. 2,345,650 A, colloquially referred to as “Unistrut” or simply “strut”) and works in conjunction with said strut rail to comprise a work-stop. After the stop is installed on the strut rail [20], the operator can tighten the vertical socket head bolt [11] in order to clamp the stop in place. The operator can then un-clamp and re-clamp the assembly wherever he or she chooses by loosening and tightening the vertical socket head bolt [11] in order to provide or remove a semi-permanent table boundary at the stop block [3]. In the case of radial arm saws, for example, this boundary serves to determine the length of a piece of cut material, and can be used to repeatedly produce similar cut lengths. If the operator wishes to drastically alter the length at which a piece will be cut, he or she can loosen the bolt [11] and reposition the entire assembly before re-tightening. If the operator wishes to minutely alter the length at which a piece will be cut, he or she can adjust the adjustment hex head bolt [6] to index the stop block [3] into the desired cutting coordinate. After cutting, the operator can then flip the stop arm [2] and stop block [3] around the pivot point of the horizontal socket head bolt [5] in order to vacate the work-stop from the work-piece plane—the space which extends from the table [22] and the fence [23] surfaces that accommodates the material to be cut. When the work-piece plane is made vacant in this manner, an operator can use the work table surface with impunity, yet will be able to reacquire the previously dialed-in cut coordinate simply through rotating the stop arm [2] and stop block [3] back into the work-piece plane.
Hardware
Apertures
Accompanying Pieces (Those not Expressly Included in the Present Invention)
The embodiments of the present invention in which an exclusive property or privilege is claimed are defined as follows:
The preferred embodiment of the present invention consists of four principal parts: the T-nut [4] is designed to reside in the channel gap [33] of a strut rail [20] which is in the “channel-up” orientation (as in
Seven pieces of hardware and corresponding apertures that are cut into the four principal parts of the preferred embodiment comprise an assembly which is designed to complement a y-coordinate work fence [23] extension, which is made of strut channel [20], for use with power equipment—such as radial chop saws [21]—or other tools that shape and modify a work piece. The present invention is clamped to the strut rail [20] through a tightening (clockwise) rotation of the vertically aligned socket head bolt [11] which serves to fasten the assembly to the strut [20] by drawing one block—the T-nut [4]—upward, and another block—the main body [1]—downward onto the strut's rolled bead [31] in the following manner: the socket head bolt [11] is a partially-threaded metal bar that is inserted into and through the main body [1] through a partially counter-bored aperture [12] and is turned in the clockwise direction when in contact with the threads of the tapped T-nut through hole aperture [14] in order to draw the T-nut [4] upward as the socket head bolt [11] applies pressure downward on the main body [1].
The stop arm [2] has of four apertures: one [15] is meant to allow for the flip-away action, while the other three apertures [16, 17] allow for the indexing action. In regards to flipping or “flip-away” action, the stop arm [2] is affixed to the main body [1] by means of a ½-13 socket head bolt [5] measuring 1.5″ in length which is fit through a 0.5″ through hole [15] in the stop arm [2] and is tightened through the interaction of the bolt's [5] threads and the threads of a tapped hole [13] drilled to a 0.75-1.0″ depth within the main body [1]. Before the present invention is installed in a strut channel but after an acceptable level of tightness—clamping strength—has been established between the stop arm [3] and the main body [1], a set screw [10] may be tightened into the set screw intersection aperture [18] until the set screw [10] makes contact with the horizontal bolt [5]. The installation of a set screw [10] lets the flip-away resistance be set to a level that is tight enough to keep cutting coordinate tolerance, but loose enough to allow for uninhibited operation. The set screw [10] is not a necessary component in the scope of the present invention, though it [10] is important if the assembly is to keep precise tolerances for an extended period of use.
In regards to indexing actions of the preferred embodiment, there are two 0.3125″ drilled apertures [16] that accommodate one 5/16″ shoulder bolt at 1.25″ length [7] each, and one 0.3230″ drilled and tapped aperture that accommodates a ⅜-16 hex head bolt [6] at 1.5″ length. The two 5/16″ shoulder bolts [7] are both first inserted through a return spring [8] and through the flip arm [2] at the 0.3125″ apertures [16] and then are threaded through a jam nut [9] before they are threaded into the stop block [3] at one of two 0.2031″ tapped stop block apertures [19]. In the preferred embodiment, the jam nuts [9] that are on the shoulder bolts [7] are then tightened against the stop block [3], securing the connection of the stop block [3] to the stop arm [2] by clamping the connection of the shoulder bolts [7] and the stop block apertures [19]. In addition to securing the stop block [3], these shoulder bolts [7] traverse within and are aligned by the 0.3125″ apertures [16] of the stop arm in order to keep the work-stop surface of the stop block [3] square with the stop arm [2] and by extension square with the strut fence [20] and the cutting agent [21, 28]. In the preferred embodiment, the return springs [8] that are penetrated by the shoulder bolts [7] provide constant pressure between the stop arm [2] and the shoulder bolts [7], which serves to eliminate lash, or backlash, as much as is mechanically feasible. The aperture [17] that is tapped at ⅜-16 and the ⅜-16 hex head bolt [6] that allow for the indexing of the stop block [3] along the x-axis are located between the previously mentioned shoulder bolts [7] and 0.3125″ alignment apertures [16]. While other work-stops include adjustment capabilities, the preferred embodiment sets the indexing apparatus in line with that which is to be adjusted—the work-piece itself—so as to minimize the possibility of flexion and deflection whenever force is applied, therefore minimizing the threat of throwing the entire assembly out of true. When the adjustment hex head bolt [6] is threaded through the correct aperture [17] and makes contact with the stop block [3], this creates a new “zero” for the work-stop surface of the stop block [3]. This “zero” acts as a point from which minute adjustments can be made, according to the precise cutting coordinates that are necessary. The adjustable hex head bolt [6] has a ⅜-16 thread pattern, and is installed into a corresponding ⅜-16 tapped aperture. Those familiar with the industry will know that a ⅜-16 thread pattern refers to the fact that a ⅜″ diameter bolt with that thread pattern, when in a nut or tapped hole with that same thread pattern, will travel one inch for every sixteen 360° revolution.
While operators may elect to alter their procedural steps within reason, a typical cutting activity—while using the present invention on a typical cutting station as seen in
1. The preferred embodiment can be used in various existing systems. Many cutting stations currently use strut channel (such as Unistrut, proposed in U.S. Pat. No. 2,345,650 A, but also those systems offered by Cooper Industries, Power Engineering Co., etc.) as a fence extender. The preferred embodiment is used with solid channel (as seen in
Provisional application No. 61/854,682 filed on Apr. 30, 2013; confirmation no. 5486 Application Ser. No. 14/257,203 371(c) Date Apr. 21, 2014; confirmation no. 2430
