# US 5,704,571 A · Cable tray and method of installation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,704,571 A - Document ID: US5704571A - Status: Granted - Kind: A - Application number: 08/307,304 - Filed: 1994-09-16 - Granted: 1998-01-06 - Earliest claimed: 1994-09-16 - Inventors: James M. Vargo - Web page: https://patentgrep.com/patent/US5704571A ## CPC - H02G 3/0456: {Ladders or other supports} - F16L 3/2431: {the special member being inserted and subsequently rotated to a limited extent} - H02G: INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES - F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL ## Abstract A cable tray that can be easily assembled at a construction location and which provides a configuration that can be modified to adapt to various on-site requirements. A preferred configuration of the cable tray disclosed herein includes a commercially standard strut suspended from an overhead surface and having a U-shaped rung fastened to the strut. The system provides a fastening system that can be installed using conventional, readily available, high-speed driver systems. The cable tray of the present invention may be mounted so as to depend from horizontal surfaces or may be directly bolted to a vertical surface. Further, the cable tray may be adapted to provided a two-tier cable tray even after installation of the primary cable tray. Various fastening systems are disclosed which attach the rung to the strut. The system is primarily designed to be highly modular so that installers can adapt individual components to particular vagrancies of a building under construction during installation of the cable tray. ## Claims ### Claim 1 A method of installing a cable tray, comprising the steps: (a) attaching an elongate strut having an elongate open recess to a building; (b) positioning an elongate rung transversely across the recess; (c) attaching the rung to the strut with a mechanical fastener after attaching the strut to the building; and (d) installing cable onto the rungs and substantially parallel to the strut. ### Claim 2 (depends on 1) The method of claim 1 wherein the step of attaching the strut to the building includes attaching a threaded rod to the building and attaching the strut to the threaded rod. ### Claim 3 (depends on 2) The method of claim 2 wherein the strut is suspended from a ceiling by the threaded rod. ### Claim 4 (depends on 1) The method of claim 1 further comprising the step of attaching the fastener to the rung before the rung is positioned transversely across the recess. ### Claim 5 (depends on 1) The method of claim 1 wherein the strut is attached to a vertical surface. ### Claim 6 (depends on 1) The method of claim 1 wherein the strut defines an aperture and the positioning step includes positioning a portion of the rung through the aperture. ### Claim 7 (depends on 1) The method of claim 1 wherein the fastener includes a nut-plate that is received in the recess such that it transversely spans the recess. ### Claim 8 (depends on 1) The method of claim 1 further comprising the steps of attaching a second strut to the strut of claim 1 and positioning a second rung against the second strut and attaching the second rung to the second strut with a second mechanical fastener. ### Claim 9 A method of installing a cable tray in a building, comprising the steps: (a) attaching a plurality of rods to the building; (b) attaching a plurality of struts to the rods wherein each strut includes surfaces that define an elongate open recess; (c) attaching a plurality of rungs to the plurality of struts after the struts have been attached to the rods; and (d) installing cable onto the plurality of rungs and substantially parallel to the plurality of struts. ### Claim 10 (depends on 9) The method of claim 9 further comprising the step of abutting together ends of the struts to form a continuous length of the plurality of struts having a continuous length of the recesses therein. ### Claim 11 (depends on 9) The method of claim 9 wherein the struts define a plurality of apertures and the step of attaching the struts to the rods includes inserting ends of the rods into some of the apertures and installing a fastener onto the rods. ### Claim 12 (depends on 9) The method of claim 9 wherein the step of attaching the rungs to the struts includes attaching a mechanical fastener to each rung and to the struts. ### Claim 13 (depends on 12) The method of claim 12 wherein the mechanical fastener comprises a bolt and a nut-plate adapted to be received in the recess and to impinge upon the surfaces that define the recess so as to prevent rotation of the nut-plate when the bolt is rotated. ### Claim 14 (depends on 9) The method of claim 9 further including the steps of attaching a second plurality of struts to the plurality of struts of claim 9 such that the struts of claim 9 and the second plurality of struts are substantially parallel, and attaching a second plurality of rungs to the second plurality of struts thereby forming a second cable tray. ### Claim 15 (depends on 9, 14) The method of claim 14 wherein the second plurality of struts are attached to the struts of claim 9 before the rungs of claim 9 are attached to the struts of claim 9. ### Claim 16 (depends on 9, 14) The method of claim 14 wherein the second plurality of struts is attached to the struts of claim 9 after the rungs of claim 9 are attached to the struts of claim 9. ### Claim 17 (depends on 9) The method of claim 9 wherein the rungs further include distal arms connected to the bight portions thereby forming a region between the bight and the arms wherein the rungs are attached to the struts such that the struts are outside the region. ### Claim 18 (depends on 9) The method of claim 9 wherein the rungs further include distal arms connected to the bight portions thereby and forming a region between the bight and arms wherein the rungs are attached to the struts such that the struts are inside the region. ### Claim 19 A method of installing a cable tray in a building, comprising the steps: (a) attaching a plurality of struts to a planer surface wherein each strut includes surfaces that define an elongate recess; and (b) attaching an arm of a plurality of rungs to the plurality of struts after the struts have been attached to the planer surfaces by attaching a mechanical fastener to each rung and to the struts. ### Claim 20 (depends on 19) The method of claim 19 wherein the mechanical fastener comprises a bolt and a nut-plate adapted to be received, within the recess and to impinge upon the surfaces that define the recess so as to prevent rotation of the nut-plate when the bolt is rotated. ### Claim 21 A method of making a cable tray comprising: (a) removably attaching a series of bar-like rungs to a length of standard commercially-available channel having rolled edges at an elongate channel opening using removable mechanical fasteners to secure the rungs to the channel such that the rungs extend at least partially across the channel opening thereby defining a cable path that is substantially parallel to the channel. ### Claim 22 (depends on 21) The method of claim 21 further including the step of attaching the mechanical fasteners to the rungs before attaching the rungs to the channel. ### Claim 23 A cable tray for holding a plurality of cables, comprising: (a) an elongate channel-shaped, commercially-available strut defining an elongate recess bounded by interior walls; (b) a rung having an attachment portion arranged transversely and spanning the elongate recess; and (c) a mechanical fastener for connecting the rung to the strut. ### Claim 24 (depends on 23) The cable tray of claim 23 wherein the strut includes opposing rolled edges and the mechanical fastener is adapted to be received in the recess and engage the rolled edges. ### Claim 25 (depends on 23) The cable tray of claim 23 wherein the rung includes a loop and the mechanical fastener is a cam that can be received within the loop and jammed against a portion of the strut. ### Claim 26 (depends on 23) The cable tray of claim 23 wherein the rung is U-shaped in profile having a bight and distal arms thereby forming a region between the bight and arms and the rung is attached to the strut such that the strut resides within the region. ### Claim 27 (depends on 23) The cable tray of claim 23 wherein the rung is U-shaped in profile having a bight and distal arms thereby forming a region between the bight and arms and the rung is attached to the strut such that the strut resides outside the region. ### Claim 28 (depends on 23) The cable tray of claim 23 wherein the fastener comprises a bolt and a nut-plate that is received within the recess and impinges against the interior walls that bound the recess such that rotation of the bolt does not rotate the nut-plate. ### Claim 29 (depends on 21, 23) The cable tray of claim 23 further comprising a second strut that is fixedly connected to the strut of claim 21 and a second rung and second mechanical fastener for attaching the second rung to the second strut thereby forming a double cable tray. ### Claim 30 A cable tray for holding a plurality of cables, comprising: (a) a strut defining an elongate open recess and further defining a plurality of apertures; (b) a rung having a U-shaped elevation including an elongate bight and distal arm portions; and (c) a mechanical fastener adapted to fixedly connect the rung to the strut such that the bight transversely spans the recess. ### Claim 31 (depends on 30) The cable tray of claim 30 wherein the fastener is an elongate shaft having an eccentric cross-section. ### Claim 32 (depends on 31) The cable tray of claim 31 wherein the fastener is located between a portion of the bight and an outside surface of the strut. ### Claim 33 (depends on 31) The cable tray of claim 31 wherein the fastener further includes an axially located recess for receiving a tool for rotating the fastener. ### Claim 34 (depends on 30) The cable tray of claim 30 wherein the bight includes a loop and the rung further comprises an annular ring that rests in the loop and is received through the aperture and wherein the fastener is located within the ring and impinges upon a surface of the strut. ### Claim 35 (depends on 30) The cable tray of claim 30 wherein the mechanical fastener comprises a bolt and a nut plate wherein the nut plate is received within the recess. ### Claim 36 A method of installing a cable tray in a building, comprising the steps: (a) attaching a plurality of rods to the building; (b) attaching a plurality of struts to the rods wherein each strut defines a plurality of apertures and includes surfaces that define an elongate recess; and (c) attaching a plurality of rungs having a bight portion including a loop to the plurality of struts after the struts have been attached to the rods by inserting the loops through the apertures. ### Claim 37 (depends on 36) The method of claim 36 wherein the step of attaching the rungs to the struts further includes inserting a cam into the loops of the rungs after the loops have been inserted through the apertures. ### Claim 38 A cable tray for holding a plurality of cables, comprising: (a) a strut defining an elongate recess and further defining a plurality of apertures; (b) a U-shaped rung including an elongate bight and distal arm portions, wherein the bight includes a loop that is received in one aperture of the strut; and (c) a mechanical fastener located within the loop such that it impinges on the strut to fixedly connect the rung to the strut such that the bight transversely spans the recess. ### Claim 39 (depends on 38) The cable tray of claim 38 wherein the fastener has an eccentric cross-section and is compressively loaded between the loop and the strut surface. ### Claim 40 A method of installing a cable tray, comprising the steps: (a) attaching an elongate strut having an elongate open recess to a building; (b) positioning an elongate rung transversely across the recess and positioning a portion of the rung into the recess; (c) attaching the rung to the strut with a mechanical fastener after attaching the strut to the building; and (d) installing cable onto the rungs and substantially parallel to the strut .