Patent Publication Number: US-8530744-B2

Title: Rail wiring duct

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 12/367,922 filed Feb. 9, 2009, which claims priority to U.S. Provisional Application No. 61/027,965, filed Feb. 12, 2008, the subject matter of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to an industrial enclosure, and more particularly, to a wiring duct for the industrial enclosure. 
     Typically, electronic components, such as cube relays, feed through terminal blocks, PLC interface modules, servo control breakout boards, circuit breaker terminal blocks, and/or fused terminal blocks, are mounted to a DIN rail, and in turn, the DIN rail is mounted to an industrial enclosure, such as a control panel, which protects the electronic components from the surrounding environment. Wiring ducts are disposed on either side of the DIN rail for routing cables to and from the electronic components. 
     While space is generally limited in the enclosure, as well as the surrounding environment, a sufficient amount of space must be provided for dissipating heat generated by the electronic components and for accessing the electronic components, as well as an interior portion of the wiring ducts. For example, the DIN rail may be mounted to the back of the enclosure. Typically, the wiring ducts are spaced apart from the electronic components by about 63.5 mm (2.5 inches). Alternatively, the DIN rail may be mounted to a DIN rail standoff, which elevates the DIN rail above the back of the enclosure by about 49.9 mm (1.96 inches). While the DIN rail standoff improves accessibility, the spacing remains unchanged. 
     Therefore, there is a need for a smaller, more compact wiring duct that provides enough space for dissipating heat generated by the electronic components and for accessing the electronic components, as well as the interior portion of the wiring duct. 
     SUMMARY OF THE INVENTION 
     Certain embodiments of the present invention provide a DIN rail wiring duct. The DIN rail wiring duct has a top, a bottom, and a side. The DIN rail wiring duct includes a base. The base has a top wall, a bottom wall, a sidewall, and a divider wall, which define a channel and a channel opening for accessing the channel. The DIN rail wiring duct also includes a cover for the channel opening. The cover has a top wall and a sidewall substantially perpendicular to the top wall. The top wall of the cover is removably connected to the top wall of the base and the sidewall of the cover is rotatably connected to the sidewall of the base such that the channels are accessible through the channel openings from the top and the side of the DIN rail wiring duct when the cover is rotated from a closed position to an open position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top front perspective view of a rail wiring duct according to a first embodiment of the present invention. 
         FIG. 2  is an exploded top front perspective view of the rail wiring duct of  FIG. 1 . 
         FIG. 3  is a front view of the rail wiring duct of  FIG. 1 , showing two covers in a closed position. 
         FIG. 4  is a partial enlargement of a mounting slot in the rail wiring duct of  FIG. 1 . 
         FIG. 5  is a cross-sectional view taken along lines  5 - 5  of  FIG. 1 . 
         FIG. 6  is a cross-sectional view taken along lines  6 - 6  of  FIG. 5 . 
         FIG. 7  is a front view of the rail wiring duct of  FIG. 1 , showing a first cover in an open position and a second cover removed therefrom. 
         FIG. 8  is a partial enlargement of the rail wiring duct of  FIG. 1 , showing a hinge mechanism and a latch mechanism. 
         FIG. 9  is a partial enlargement of the hinge mechanism in the rail wiring duct of  FIG. 1 , showing a cover in an open position. 
         FIG. 10  is a partial enlargement of the hinge mechanism in the rail wiring duct of  FIG. 1 , showing a cover removed therefrom. 
         FIG. 11  is a top front perspective view of a machine screw and a T-nut. 
         FIG. 12  is a cross-sectional view taken along lines  5 - 5  of  FIG. 1 , showing an alternative to the first embodiment of the present invention that utilizes the machine screw and the T-nut of  FIG. 11 . 
         FIG. 13  is a cross-sectional view taken along lines  6 - 6  of  FIG. 5 , showing the alternative to the first embodiment of the present invention that utilizes the machine screw and the T-nut of  FIG. 11 . 
         FIG. 14  is a top front perspective view of a rail wiring duct according to a second embodiment of the present invention. 
         FIG. 15  is an exploded top front perspective view of the rail wiring duct of  FIG. 14 . 
         FIG. 16  is a front view of the rail wiring duct of  FIG. 14 , showing two covers in a closed position. 
         FIG. 17  is a front view of the rail wiring duct of  FIG. 14 , showing a first cover in a first open position and a second cover in a second open position. 
         FIG. 18  is a front view of the rail wiring duct of  FIG. 14 , showing a top wall and a divider wall that are partially removed therefrom. 
         FIG. 19  is a top front perspective view of a rail wiring duct according to a third embodiment of the present invention. 
         FIG. 20  is an exploded top front perspective view of the rail wiring duct of  FIG. 19 . 
         FIG. 21  is a front view of the rail wiring duct of  FIG. 19 , showing two covers in a closed position. 
         FIG. 22  is a front view of the rail wiring duct of  FIG. 19 , showing a first cover in a first open position and a second cover in a second open position. 
         FIG. 23  is a front view of the rail wiring duct of  FIG. 19 , showing an integrally formed top wall and divider wall that is partially removed therefrom. 
         FIG. 24  illustrates a cover for the rail wiring duct of  FIG. 1  according to an alternative embodiment of the present invention. 
         FIG. 25  is a side view of the cover of  FIG. 24  on the rail wiring duct of  FIG. 1 , showing the cover being flexed and rotated from a closed position to an open position. 
         FIG. 26  is a side view of the cover of  FIG. 24  on the rail wiring duct of  FIG. 1 , showing the cover in an open position. 
     
    
    
     The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, certain embodiments are shown in the drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-10  illustrate a rail wiring duct  100  according to a first embodiment of the present invention. The rail wiring duct  100  includes a base  110  and two covers  120 . Each of the covers  120  is attached to the base  110  by a hinge mechanism  130  on one side and a latch mechanism  140  on the other side. The rail wiring duct  100  may be foamed from any suitable material, but is preferably formed from a plastic material, such as polyvinylchloride (“PVC”). The rail wiring duct  100  is preferably formed by extrusion followed by one or more secondary operations, such as punching of fingers and holes, as necessary. 
     As shown in  FIG. 1 , the rail wiring duct  100  is secured to a backplane  10  of an industrial enclosure (not shown). A DIN rail  30  is secured to the rail wiring duct  100 , and DIN rail mounted components  40 , such as cube relays, feed through terminal blocks, PLC interface modules, servo control breakout boards, circuit breaker terminal blocks, and/or fused terminal blocks, are secured to the DIN rail  30 . Wires  50  connecting the DIN rail mounted components  40  are routed through the rail wiring duct  100 . It is likewise contemplated that the rail wiring duct  100  may be installed in a variety of other environments. 
     As best seen in  FIG. 3 , the base  110  includes a top wall  150 , a bottom wall  160 , two sidewalls  170 , and a divider wall  180 , which may be integrally formed or affixed together. The top wall  150 , the bottom wall  160 , the sidewalls  170 , and the divider wall  180  define two channels  190  and two channel openings  195  for accessing the channels  190 . The channel openings  195  are accessible from both the top and the side of the rail wiring duct  100 . 
     As best seen in  FIG. 4 , the top wall  150  of the base  110  includes a DIN rail mounting slot  152  and two DIN rail alignment ribs  151 . The DIN rail  30  is positioned between the DIN rail alignment ribs  151  and secured to the top wall  150  using a plurality of fasteners  153 , such as screws, as shown in  FIGS. 4-6 , and/or T-nuts, as shown in  FIGS. 11-13 . For example, the DIN rail  30  may be screwed directly into the DIN rail mounting slot  152 , as shown in  FIGS. 4-6 . Alternatively, the DIN rail  30  may be screwed into T-nuts disposed in the DIN rail mounting slot  152 , as shown in  FIGS. 11-13 . 
     As best seen in  FIG. 3 , the bottom wall  160  of the base  110  includes a first bottom wall section  161  and a second bottom wall section  162 . The wall thickness of the bottom wall  160  may be varied to provide additional support for the DIN rail  30  and the DIN rail mounted components  40 . For example, as shown in  FIG. 3 , the wall thickness BWT 1  of the first bottom wall section  161  is greater than the wall thickness BWT 2  of the second bottom wall section  162 , as well as the nominal wall thickness NWT of the rail wiring duct  100 . The second bottom wall section  162  includes a plurality of mounting holes  163  for attaching the rail wiring duct  100  to the backplane  10  of the industrial enclosure (not shown) using a plurality of fasteners  164 , such as rivets, as best seen in  FIG. 2 . 
     As best seen in  FIG. 3 , the divider wall  180  includes a first divider wall section  181 , a second divider wall section  182 , and a third divider wall section  183 . The shape and/or configuration of the divider wall  180  may be varied to provide additional support for the DIN rail  30  and the DIN rail mounted components  40 . For example, as best seen in  FIG. 3 , the first divider wall section  181  and the third divider wall section  183  are substantially V-shaped, with the latter being inverted. The second divider wall section  182  is straight and bridges the first divider wall section  181  and the third divider wall section  183 . Additionally, the wall thickness of the divider wall  180  may be varied to provide additional support for the DIN rail  30  and the DIN rail mounted components  40 . For example, the wall thickness DWT 2  of the second divider wall section  182  and the wall thickness DWT 3  of the third divider wall section  183  are greater than the wall thickness DWT 1  of the first divider wall section  181 , as well as the nominal wall thickness NWT of the rail wiring duct  100 . The second divider wall section  182  includes a plurality of through holes  184  for routing the wires  50  between the channels  190 . 
     As shown in  FIG. 3 , each of the covers  120  is substantially L-shaped and includes a top wall  121  and a sidewall  122 . The top wall  130  of the base  110  and the top walls  121  of the covers  120  collectively form a top wall of the rail wiring duct  100 . Similarly, the sidewalls  170  of the base  110  and the sidewalls  122  of the covers  120  collectively form the sidewalls of the rail wiring duct  100 . As described below in more detail, the top wall  121  of the cover  120  includes one or more components of the latch mechanism  140 , and the sidewall  122  of the cover  120  includes one or more components of the hinge mechanism  130 . 
     As shown in  FIG. 2 , the top wall  150  of the base  110  includes a plurality of top wall fingers  155 . Similarly, the sidewalls  170  of the base  110  include a plurality of sidewall fingers  175 . The fingers  155 ,  175  are separated by a plurality of slots  156 ,  176 . Each of the fingers  155 ,  175  includes one or more pairs of ears  157 ,  177 . The ears  157 ,  177  help to retain wires  50  in the slots  156 ,  176 , particularly when the covers  120  are opened or removed. As described below in more detail, the top wall fingers  155  include one or more components of the latch mechanism  140  and the sidewall fingers  175  include one or more components of the hinge mechanism  130 . 
     As shown in  FIG. 8 , the rail wiring duct  100  includes the hinge mechanism  130  and the latch mechanism  140 . The hinge mechanism  130  connects the sidewall  122  of the cover  120  to the sidewall  170  of the base  110  and allows the cover  120  to rotate from a closed position CP, as shown in  FIGS. 1 ,  3 , and  8 , to an open position OP, as shown in  FIGS. 7 and 9 . Additionally, the hinge mechanism  130  is separable and allows the cover  120  to be disconnected and removed from the base  110 , as shown in  FIGS. 7 and 10 . The latch mechanism  140  connects the top wall  121  of the cover  120  to the top wall  150  of the base  110 , and locks the cover  120  in the closed position CP. 
     As best seen in  FIG. 8 , the hinge mechanism  130  includes a ball  131  and a socket  132 . The ball  131  is disposed on the base  110  of the rail wiring duct  100 , at a distal end of each sidewall finger  175 . The socket  132  is disposed on the cover  120  of the rail wiring duct  100 , at a distal end of the cover sidewall  122 . The socket  132  is formed by two socket arms  133 . One of the socket arms  133  includes an undercut  134 , which secures the ball  131  within the socket  132 . As best seen in  FIG. 9 , the ball  131  is free to rotate within the socket  132 . As best seen in  FIG. 10 , the socket arms  133  are resiliently deflectable, which allows the ball  131  to be inserted into or removed from the socket  132 . Therefore, the base  110  and the cover  120  of the rail wiring duct  100  are rotatably and removably connected by the hinge mechanism  130 . 
     Additionally, as best seen in  FIG. 8 , the latch mechanism  140  includes a latch arm  141 , a latch pocket  142 , and a release arm  143 . The latch arm  141  is disposed on the base  110  of the rail wiring duct  100 , at a distal end of each top wall finger  155 . The latch pocket  142  and the release arm  143  are disposed on the cover  120  of the rail wiring duct  100 , at a distal end of the cover top wall  121 . The latch pocket  142  is formed by a pocket arm  144  and a portion  145  of the release arm  143 . The latch arm  141  engages the latch pocket  142 , locking the cover  120  in the closed position CP. When the release arm  143  is depressed, the latch arm  141  disengages from the latch pocket  142 , unlocking the cover  120  and allowing the cover  120  to rotate from the closed position CP to the open position OP. 
     In certain embodiments of the present invention, the cover  120  may include one or more flexible wall sections and one or more rigid or inflexible wall sections. For example, as best seen in  FIG. 24 , the sidewall  122  of the cover  120  includes a first wall section  123 , a second wall section  124 , and a third wall section  125 . The first wall section  123  is disposed between the second wall section  124  and the third wall section  125 . The first wall section  123  is relatively flexible compared to the second wall section  124  and the third wall section  125 . Conversely, the second wall section  124  and the third wall section  125  are relatively rigid or inflexible compared to the first wall section  123 . The top wall  121  of the cover  120  is also relatively rigid or inflexible compared to the first wall section  123 . For example, the first wall section  123  may be made from flexible PVC, and the second wall section  124 , the third wall section  125 , and the top wall  121  may be made from rigid PVC. As shown in  FIG. 25 , the first or flexible wall section  123  allows the sidewall  122  of the cover  120  to bend or flex, making the latch mechanism  140  easier to disengage, and therefore, the cover  120  easier to open and/or remove. As shown in  FIG. 26 , the first or flexible wall section  123  is resilient. That is, the sidewall  122  of the cover  120  returns to its original form after being released. 
       FIGS. 14-18  illustrate a rail wiring duct  200  according to a second embodiment of the present invention. The rail wiring duct  200  is similar to the rail wiring duct  100  of  FIG. 1 , except that the rail wiring duct  200  includes an angled, dual hinge-cover  220  and a removable divider wall  280 . 
     As best seen in  FIG. 16 , the cover  220  is oriented at an angle A of about 45 degrees with respect to the bottom wall  260  of the base  210 . The angle A may be varied from about 0 degrees to about 90 degrees. Varying the angle A of the cover  220  changes the profile of the rail wiring duct  200 , which may be advantageous in installations where space is limited. 
     As best seen in  FIGS. 16-17 , each of the covers  220  includes two hinge mechanisms  230 , which allow the cover  220  to rotate from a closed position CP, as shown in  FIG. 16 , to one of two open positions OP 1 , OP 2 , as shown in  FIG. 17 . Additionally, the cover  220  is removable at one or both of the hinge mechanisms  230 . 
     As best seen in  FIG. 18 , the top wall  250  and the divider wall  280  are removable from the base  210 , which allows the top wall  250  and/or the divider wall  280  to be formed from a different material than the base  210 . For example, the base  210  of the rail wiring duct  200 , including the bottom wall  260  and the sidewalls  270 , may be extruded from a plastic material, such as PVC, while the divider wall  280  is extruded from a metal, such as aluminum. One advantage of forming the divider wall  280  from a different material than the base  210  is to provide additional support for the DIN rail  30  and the DIN rail mounted components  40 . Additionally, a top wall  250  and a divider wall  280  that are removable are easier to manufacture using existing punching technology. 
       FIGS. 19-23  illustrate a rail wiring duct  300  according to a third embodiment of the present invention. The rail wiring duct  300  is similar to the rail wiring duct  100  of  FIGS. 1-13 , except that the rail wiring duct  300  includes an elevated, dual-hinge cover  320  and an integrally formed, removable top wall  350  and divider wall  380 . 
     As best seen in  FIG. 21 , the top wall  350  of the base  310  is substantially U-shaped and includes top wall fingers  355 . The top wall fingers  355  are substantially parallel to the sidewall fingers  375  and extend beyond the DIN rail  30 . Consequently, the covers  320  are elevated with respect to the DIN rail  30 . Compared to the rail wiring duct  100  of  FIGS. 1-10 , the sidewalls  322  of the cover  320  have been shortened and the sidewalls  370  of the base  310  have been lengthened, although other configurations are likewise contemplated. Additionally, similar to the sidewall fingers  375 , the top wall fingers  355  are vertically oriented, and thus, easier to manufacture using existing punching technology. 
     As best seen in  FIGS. 21-22 , each of the covers  320  includes two hinge mechanisms  330 , which allow the covers  320  to rotate from a closed position CP, as shown in  FIG. 21 , to one of two open positions OP 1 , OP 2 , as shown in  FIG. 22 . Additionally, the covers  320  are removable at one or both of the hinge mechanisms  330 . 
     As best seen in  FIG. 23 , the top wall  350  and the divider wall  380  are integrally formed and removable from the base  310 , which allows the top wall  350  and the divider wall  380  to be formed from a different material than the base  310 . For example, the base  310  of the rail wiring duct  300 , including the bottom wall  360  and the sidewalls  370 , may be extruded from a plastic material, such as PVC, while the top wall  350  and the divider wall  380  may be extruded from a metal, such as aluminum. One advantage of forming the top wall  350  and the divider wall  380  from a different material than the base  310  is to provide additional support for the DIN rail  30  and the DIN rail mounted components  40 . Additionally, a top wall  250  and a divider wall  280  that are integrally formed and removable is easier to manufacture using existing punching technology. 
     While particular elements, embodiments and applications of the present invention have been shown and described, it is understood that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teaching. It is therefore contemplated by the appended claims to cover such modifications and incorporate those features that come within the spirit and scope of the invention.