Stackable washer

Abstract: A stackable roofing washer (18) which has a central aperture (20) which can receive a fastener which passes through a roofing material and into the roofing underlay. The washer (18) has at least one notch (64, 66) in its periphery which can co-operate with a rib in a chute of a washer dispensing machine to prevent a stack of the washers from cascading when the chute is tipped.

Description: This invention relates to roofing washers which are stacked in a chute for use in the fastening of one or more layers of roofing material, such as a blanket of roofing insulation or a roofing membrane, to an underlayment, such as a wooden roof or a corrugated metal roof. To fasten the roofing material, roofing washers are individually positioned on the material and a fastener having a head, such as a screw, is driven through a central aperture of the washer, through such material, and into the underlayment, until the fastener bears against the washer. Herein, terms such as "roof" and "roofing" are to be broadly understood, so as to cover roofs, decks, ceilings, and similar structures. Generally, a washer-dispensing and fastener-driving machine is used to dispense washers individually on the roofing material, and to then drive the fastener into the underlayment. The washers are usually stacked in a magazine in the machine ready for dispensing. Roofing washers are disclosed in Dewey U.S. Patent Des. 263,678, Dewey U.S. Patent Des. 263,927, and Dewey U.S. Patent Des. 263,928, which are assigned to Illinois Tool Works Inc. of Chicago, Illinois, the applicant hereof. All of the washers have a central aperture, which is adapted to receive a fastener, and are embossed with a pattern of ribs so as to have positive relief and planar areas on its upper face and negative relief and planar areas on its lower face. The ribs on the washers are functional, as well as ornamental, since the ribs strengthen and rigidify the washers, which can therefore be made from thin blanks. Ordinarily, when stackable washers, such as those according to any of the Dewey patents noted above, are made in a mechanical or hydraulic press employing metal-working dies, a lubricating medium is used which tends to leave some residue on each washer. It is uneconomical to clean such residue from each washer. Because such residue tends to be somewhat adherent, and because the washers tend to be tightly stacked, it is difficult to dispense the washers individually in a washer-dispensing machine, since a plurality of such washers tend to be simultaneously displaced from a stack of such washers in such a machine, whereby the machine can become jammed. Although the washers noted above are typically square, except for rounded corners, circular roofing washers and oblong roofing washers also are known. Circular roofing washers have particular utility with roofing membranes, which tend to be easily punctured. Washers with countersunk apertures are preferred for overlying more compressible material, such as a blanket of roofing insulation, whereas washers without countersunk apertures are preferred for overlying less compressible material, such as a roofing membrane, which would be typically applied over a blanket of roofing insulation. It is desirable to countersink the heads of fasteners used to fasten a blanket of roofing insulation to an underlayment, if a roofing membrane is to be later applied over the blanket of roofing insulation, in an effort to avoid puncturing the roofing membrane where the fastener heads would underlie the roofing membrane and where a worker might step carelessly or unwittingly. Stackable washers according to Dewey U.S. Patent Des. 268,678, as produced from steel blanks and embossed to countersink their central apertures relative to positive relief on their upper faces and negative relief on their lower faces, and as sold by ITW-Buildex (a division of Illinois Tool Works Inc.) of Itasca, Illinois, have enjoyed commercial success in the United States in recent years. Washers are known which include features suitable for ensuring the correct orientation of the washer. FR-A-966,761 shows an example of one such washer which includes two notches in the outer circumference of the washer. According to the present invention, a stackable, individually machine-dispensable, roofing washer for use with roofing material, such as a blanket of roofing insulation or a roofing membrane, the washer being arranged to be stacked in a stack receiving chute, and has a periphery, and a central aperture adapted to receive a fastener, and is characterised in that the washer is formed with one or more notch in its periphery, the or each notch adapting the washer and a like overlying and underlying washer in a stack to fit into a washer stack-receiving chute of a washer-dispensing machine, the or each notch corresponding with a rib in the chute to restrain washers in a stack against cascading from the stack if the chute is tipped, and in that the washer includes radial ribs arranged so that the entire periphery of the washer is separated from like overlying and underlying washers in a stack. Preferably the roofing washer is embossed with a pattern of ribs which stiffen the washer, and the ribs are preferably spaced outwards from the central aperture, so as to provide positive relief and planar areas on one of the faces, and negative relief and planar areas on the other of the faces. Moreover, when a stack of such washers is made for use in the washer-dispensing and fastener-driving machine described above as provided by this invention, such relief forms camming surfaces on the given one of the broad faces of each such washer. Each washer may be advantageously made from a steel blank, which may be so embossed in a mechanical or hydraulic press employing matched dies and a lubricating medium, and which may be previously or subsequently galvanized. As embossed, such washer is nestable with like overlying and underlying washers in a stack such that positive relief on such washer nests into negative relief on an overlying washer in the stack, and such that positive relief on an underlying washer in the stack nests into negative relief on such washer. Preferably, the washers are embossed such that each washer and like overlying and underlying washers in a stack contact each other at three or more places, which are defined by ribs on such washer and ribs on like underlying and overlying washers in the stack, and which define tangent planes intersecting planes defined by planar areas on each of the broad faces of such washer at angles more than 45° but less than 90°, preferably about 60°. These places, which are located where positive relief nests into negative relief, are spaced from the central aperture of such washer and from the peripheries of such washer and of like washers in the stack. Consequently, such washer and like overlying and underlying washers in the stack are spaced from each other around their entire peripheries, so as to facilitate their being individually machine-dispensible with little tendency to adhere to each other even if coated partly or wholly with residue of a lubricating medium. If tangent planes, as defined by the ribs where each washer provided by this invention and like overlying and underlying washers in a stack contact each other, were to intersect planes defined by planar areas on each of tne broad faces of the washer at angles of 45° or less, such washer and like overlying and underlying washers in the stack could be tightly stacked, rather than spaced from each other around their entire peripheries. Angles less than 90° are required for nesting. As mentioned above, angles of about 60° are preferred. Theoretically, two stacked washers can contact each other at three places only. Practically, however, two stacked washers can appear to contact each other at more than three places. This invention does not distinguish between actual contact, in a theoretical sense, and apparent contact, in a practical sense. In some forms that have been envisioned, each washer provided by this invention is embossed with radial ribs, preferably with at least three ribs, the rib or ribs defining positive relief on the given one of its broad faces, defining negative relief on the other one of its broad faces, and defining such places where the washer and like overlying and underlying washers in a stack contact each other. The ribs of such washer may be advantageously disposed in regularly spaced intervals around its central aperture. Preferably, such washer is embossed with four such ribs, which extend in radial directions relative to the central aperture. The broad faces of such washer may be substantially square with four such ribs extending diagonally along the broad faces. Desirably, if such washer is used to overlie more compressible material, such as a blanket of roofing insulation, rather than less compressible material, such as a roofing membrane, such washer may be also embossed so as to countersink its central aperture relative to positive relief on the given one of its broad faces and to negative relief on the other one of its broad faces. Such washer may be further embossed, as for ornamental purposes or for strengthening and rigidifying purposes, so long as any further embossing does not cause such washer and like overlying and underlying washers in a stack to be no longer separated around their entire peripheries. Preferably, if such washer is embossed so as to have positive relief on one broad face and negative relief on its other face, so as to have a countersunk portion, which includes its central aperture, or so as to achieve both purposes, the notch or notches are located so as to perform another function, namely to ensure that the broad face having positive relief is the upper face when the washer is fitted into the chute with the rib or ribs fitting into the notch or notches of such washer. To achieve this, the notch or notches should be placed assymetrically. The rib or ribs prevent the washer from being rotated when fitted into the chute and from being inverted when fitted into the chute. A stack of washers, each having a notch or spaced notches for purposes described above, may be advantageously packaged in a container, which is fittable with the stack into a washer-receiving chute having a rib or spaced ribs fittable into the notch or notches, and which has side walls covering peripheries of the washers in the stack, except for a slot or spaced slots exposing the notches and allowing the rib or ribs to fit through the slot or slots into the notch or notches to restrain the washers in the stack against cascading from the stack if the chute is tipped so as to tip the stack. The container may be openable to allow washers in the stack to drop from the container when the container is fitted into the chute of the dispensing machine. The washer according to this invention is preferably circular, but may be square with the ribs extending diagonally. Washers according to this invention can be used in any washer dispensing machine including ribs in the chute for co-operation with the notches on the washer. Preferably, the washers are used in a washer-dispensing and fastening-machine according to our co-pending European Application No. 90301033.8 with publication no. EP-A-0 383 458 from which this application is divided. Particular embodiments of washers according to this invention will now be described with reference to the accompanying drawings, in which:- Figure 1 is a perspective view of a stack of roofing washers in a container having a removable lower cover; Figure 2 is a greatly enlarged, partly fragmentary, exploded, perspective view of the stack of roofing washers in the container; Figure 3 is a plan view of a washer; and Figures 4, 5 and 6 are greatly enlarged, fragmentary, sectional views, as taken along lines 21--21, 22--22 and 23--23 respectively of Figure 3 in the directions indicated by arrows. As shown in Figures 3 to 6, each washer 18 is substantially square, except for rounded corners 302, 304, at its leading edge 306 and rounded corners 308, 310, at its trailing edge 312. Each washer 18 is provided, at one lateral edge 314, with a notch 64, which is spaced by a given distance from its trailing edge 312. Each washer 18 is provided, at its opposite lateral edge 316, with a notch 66, which is spaced by a greater distance from its leading edge 306. The notches 66, 64, adapt each washer 18 to fit into a chute 50 of a washer dispensing-machine with a rib 60 fitting into the notch 64 and with a rib 62 fitting into the notch 66. When the stack of such washers 18 is fitted into the chute 50, the respective ribs, by fitting into the respective notches in the washers 18 in the stack, restrain the washers 18 in the stack against cascading from the stack S if the machine including the chute 50 is tipped so as to tip the stack. Unlike previous arrangements, there is no need for an overlying weight to restrain the washers 18 in the stack from cascading. Generally, each washer 18 is made from a steel blank by embossing such blank as in a mechanical or hydraulic press (not shown) employing matched dies and a lubricating medium, so as to have positive relief and planar areas on its upper face, so as to have negative relief and planar areas on its lower face, and so as to have a countersunk portion 330, which includes the central aperture 20 of such washer 18. Positive relief on the upper face of such washer 18 provides camming surfaces. The notches 64, 66 cause such washer 18 to be assymetrically shaped, as the chute 50 is shaped, thereby to ensure that the broad face having positive relief is the upper face with the countersunk portion 330 below the periphery of such washer 18. The ribs 60, 62 prevent such washer 18 from being inserted in an improper orientation into the chute 50. As shown, each washer 18 is embossed with an ornamental and functional pattern of ribs including an annular rib 340 in a circular pattern around the counter-sunk portion 330, and annular rib 342 in an octagonal pattern around the annular rib 340, peripheral ribs 344, 346, 348, 350, in a square pattern along peripheral areas of such washer 18 and radial ribs 352, 354, 356, 358, along diagonal paths, between straight sections of the annular rib 342 and intersections formed by the peripheral ribs 344, 346, 348, 350. Such ribs, which strengthen and rigidify such washer 18, define positive relief and planar areas on one broad face of such washer 18 and negative relief and planar areas on the other face of such washer 18. Thus, in the stack comprising a plurality of washers 18, positive relief defined by such ribs on each washer 18 nests into negative relief defined by such ribs on an overlying washer in the stack and positive relief defined by an underlying washer in the stack nests into negative relief defined by such ribs on such washer 18. The radial ribs 352, 354, 356, 358 are configured in cross section so as to define at least three places, which are located where positive relief nests into negative relief, at which each washer 18 and like overlying and underlying washers in the stack contact each other, and which define tangent planes T intersecting planes P defined by planar areas on each of the upper and lower faces of such washer 18 at angles more than 45° but less than 90°, preferably 60°, as shown in Figure 5, which shows several of the washers 18 from the stack, and in which such an angle is indicated by β. Consequently, each washer 18 and like overlying and underlying washers 18 in the stack are spaced from each other around their entire peripheries and between planar areas on such washers 18, as shown in Figure 6, in which the leading edges 306 of several of the washers 18 from the stack are shown. Because they are spaced from each other around their entire peripheries and between planar areas thereon, such washers 18 have little tendency to adhere to each other when dispensed individually by the machine even if coated partly or wholly with residue of a lubricating medium. As shown in Figures 1 and 2, the stack of washers 18 may be conveniently packaged in a container 260, which may be advantageously thermo-formed from a suitable, opaque, polymeric material, such as polyethylene terephthalate or polypropylene, or which may be alternatively made from paperboard or card stock with glued flaps. A removable, lower cover 262 is provided, which may be similarly thermo-formed or otherwise made, as from the material of the container 260. As shown in Figure 2, the stack may be conveniently left in the container 260, after the cover 262 has been removed, when the stack is inserted manually into the washer-receiving chute 50 of a washer-dispensing machine, which provides sufficient clearance for such a container having thin walls. The container 260 has a top wall 264, a rear wall, which is hidden in Figures 1 and 2, a front wall 266, a side wall 268, which is shown fragmentarily in Figures 1 and 2, and a side wall 270. When the stack is left in the container 260, the container 260 rests on edge portions of a shuttle of a washer-dispensing machine, so as to span the recessed rear portion of the shuttle, when the shuttle is in the displaced position. Otherwise, as shown, the container 260 is seated across the shuttle. The top wall 264 and the side wall 268 are provided with a vertical slot 274, which is disposed so as to expose the notches 64 in the washers 18 in the stack S. The top wall 264 and the side wall 270 have a vertical slot 276, which is disposed so as to expose the notches 66 in the washers 18 in the stack. Thus, the slot 274 permits the rib 60 in the chute of the washer-dispensing means to fit through the slot 274 into the notches 64 in the washers 18 in the stack and the slot 276 permits the rib 62 to fit through the slot 276 into the notches 66 in the washers 18 in the stack, thereby to restrain the washers 18 in the stack against cascading from the stack S if the machine including the chute 50 is tipped so as to tip the stack. The front wall 266 has an inverted V-shaped cutout 278, which facilitates handling the stack in the container 260, after the cover 262 has been removed, as when the stack is to be manually inserted into the chute 50. Similarly, the front wall may have an inverted V-shaped cutout (not shown) at its lower edge. As a preliminary step, operation of the machine requires the stack of roofing washers 18, either in the container 260 after the cover 262 has been removed or apart from any container, to be manually inserted into the washer-receiving chute 50 with the rib 60 fitting into the notches 64 in the stacked washers 18 and with the rib 62 fitting into the notches 66 in the stacked washers 18.

Claims: A stackable, individually machine-dispensable, roofing washer (18) for use with roofing material, such as a blanket of roofing insulation or a roofing membrane, the washer (18) being arranged to be stacked in a stack receiving chute, and having a periphery, and a central aperture (20) adapted to receive a fastener, characterised in that the washer is formed with one or more notch (64, 66) in its periphery, the or each notch (64, 66) adapting the washer (18) and a like overlying and underlying washer in a stack to fit into a washer stack-receiving chute (50) of a washer-dispensing machine, the chute being provided with a rib (60, 62) corresponding to the or each notch (64, 66) to restrain washers in a stack received by the chute (50) against cascading from the stack if said chute (50) is tipped, and in that the washer (18) includes radial ribs (352, 354, 356, 358) arranged so that the entire periphery of the washer (18) is separated from like overlying and underlying washers (18) in a stack. A stackable, individually machine-dispensable, roofing washer (18) according to claim 1 further characterised in that the washer is embossed with a pattern of ribs (352, 354, 356, 358), which stiffen the washer (18) and are spaced outwards from the central aperture (20), so as to provide positive relief and planar areas on one of the faces, and negative relief and planar areas on the other of the faces, the washers being nestable with like overlying and underlying washers (18) in a stack (S) with the washer and the like overlying and underlying washers contacting each other at three or more places, which are defined by their ribs (352, 354, 356, 358), and which define tangent planes intersecting planes defined by planar areas on each of the faces of the washer at angles of more than 45° but less than 90°. A stackable washer according to claim 1 or 2, in which is embossed so as to countersink (330) the central aperture (20). A washer according to any of the preceding claims, which is embossed to have a countersunk portion (330), which includes the central aperture (20), and an assymetrically placed notch or notches (64, 66), the notch or notches ensuring that the countersunk aperture (330) is below the periphery of the washer (18) when it is fitted into a chute (50) with the ribs (60, 62) fitting into the notch or notches (64, 66). A stack of roofing washers comprising the washer (18) of any of the preceding claims and like overlying and underlying washers (18) packages in a container (260), having side walls (260, 270) covering peripheries of the washers (18) in the stack, except for a slot (274, 276) exposing the or each notch (64, 66) and allowing the or each rib (60, 62) of a chute (50) to fit through the slot (274, 276) into the notch (64, 66) to restrain such washers (18) in the stack against cascading from the stack if the chute (50) is tipped so as to tip the stack, the container (260) being openable to allow washers in the stack to drop from the container (260) when the container (260) is fitted into the chute (50). A washer according to any one of the preceding claims, which is embossed with radial ribs (352, 354, 356, 358) defining positive relief on one of its faces, defining negative relief on the other of its faces, and defining places where the washer (18) and like overlying and underlying washers (18) in a stack contact each other. A washer according to any one of the preceding claims, which is substantially square and wherein the ribs (352, 354, 356, 358) extend diagonally.

Inventors: BEACH JOHN R, HASAN SYED RIAZ-UI, HINDMAN CRAIG ALLAN, NOREN DONALD W, SANTI ERNEST SCOTT, BEACH, JOHN R., HASAN, SYED RIAZ-UI, HINDMAN, CRAIG ALLAN, NOREN, DONALD W., SANTI, ERNEST SCOTT
Applicants: ILLINOIS TOOL WORKS, ILLINOIS TOOL WORKS INC.
Application year: 1990
Main classification: F16B43
IPC codes: F16B43, E04D5, E04D3, B25B23, E04D15