Abstract:
A camera skid and thrust nozzle assembly for supporting a camera while being positioned in a tubular pipe or conduit spaced. from any wall of the conduit and permitting movement of the assembly along the conduit. The assembly includes a cage rotatably fastened to a high pressure fluid tractor nozzle, wherein the cage can rotate about an axis through the tractor nozzle. A camera support structure is fastened within the cage for rotation of the support structure about the axis independent of rotation of the cage. The camera support structure has a weight attached thereto for urging rotational orientation of the camera support structure within the cage according to a sensed external gravitational force on the assembly.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority of U.S. Provisional Application No. 61/804,639, filed Mar. 23, 2013, and No. 61/912,458, filed Dec. 5, 2013, both entitled Camera Skid Tractor Nozzle Assembly. These applications are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     A high pressure rotary nozzle and tractor device is disclosed in U.S. Patent Application Publication No. 20120205405. A high pressure fluid switching valve tractor device for use with a nozzle is also disclosed in U.S. Pat. No. 8,667,987. These publications are hereby incorporated by reference in their entirety. Such nozzles and tractor devices are particularly well suited to industrial uses where the operating parameters can be in the range of 1,000 to 40,000 psi and flow rates of 5 to 150 gpm, and when rotary nozzles are employed, rotating speeds of 10 to 1000 rpm or more may be needed. 
     For inspection of sewer lines and other large buried or surface piping systems there is a need for a robust mechanism for viewing such systems internally to better understand blockages, restrictions and obstructions without unearthing and breaking open the system. Several solutions to this problem have been identified. One such system places a camera on a sled at the end of a hose that has jet nozzles to propel the sled down the piping ahead of the hose. However, the hose naturally has some twist as it is advanced and retracted which tends to cause the sled to tip over. Therefore there is a swivel that is installed to allow the hose to roll while the sled stays upright. However, friction in the swivel at operating pressure apparently prevents this swivel from performing the desired function. Thus the sled upon which the camera is mounted tips over and becomes submerged in whatever fluid is within the piping, especially when trying to negotiate around bends in the piping system. The present disclosure addresses this difficulty in a new manner. 
     SUMMARY OF THE DISCLOSURE 
     Embodiments in accordance with the present disclosure eliminate a fluid carrying swivel to address the above difficulty. One embodiment in accordance with the present disclosure includes a camera module mounted on a camera tray that is rotatably supported from journal bearings on an axle that extends through one end of a cage skid that is, in turn, fastened to a tractor nozzle that is attached to an end of a high pressure hose. Such a hose may be pressurized to somewhere between 100 psi to 20000 psi, depending on the service for which it is designed. 
     The cage skid is preferably made of a central bearing sleeve having three or more radially extending ribs that extend outward from the central bearing sleeve and bend so as to extend parallel to the central bearing sleeve to a point beyond the camera tray. These ribs then reconnect around the camera module so as to present a protective cage structure around the camera module. The three or more ribs are preferably axially symmetric, so that if the cage rotates on its axis, the camera module is held at an elevation above an anticipated liquid level in the conduit or pipe. This axle is rotatably supported by the skid and the same axle rotatably supports the camera tray such that it can freely rotate to remain upright as the cage rotates on its axis. The axle extends axially from a tractor nozzle that may have a plurality of rearwardly directed nozzle tips to provide a forward thrust on the skid so as to at least assist in propelling the skid through a length of pipe in a piping system such as a sewer line. A conventional high pressure hose is attached to the tractor nozzle. 
     Another embodiment could involve two skids positioned in parallel contacting the bottom of a pipe if the pipe is large enough. Such a configuration would greatly reduce the likelihood of tipping of the cage skids and thus improve assurance the camera module would not likely become submerged in fluid within bottom portion of a pipe through which it is being propelled by fluid jets. 
     Another embodiment of an assembly in accordance with the present disclosure includes a camera module mounted on a camera tray that is rotatably supported from an axle that extends through one end of a cage skid that is, in turn, fastened to a rotary bearing in turn mounted to a rotary nozzle and to a switcher tractor nozzle such as is disclosed in U.S. Patent Publication No. 20120205405 mentioned above. This switcher tractor nozzle is then attached to an end of a high pressure hose. Such a hose may be pressurized to somewhere between 100 psi to 20000 psi, depending on the service for which it is designed. The cage skid is preferably made of a central bearing sleeve having three or more radially extending ribs that extend outward from the central bearing sleeve and bend so as to extend parallel to the central axial bearing sleeve to a point beyond the camera tray. These ribs then reconnect around the camera module so as to present a protective cage structure around the camera module. The skid rotatably supports the same axle as the camera tray such that it can freely rotate to negotiate piping bends. The axle extends axially from a tractor nozzle that may have a plurality of rearwardly directed nozzle tips to provide a forward thrust on the skid so as to at least assist in driving the skid through a length of pipe in a piping system such as a sewer line. 
     In both of these embodiments described above, the camera module is preferably mounted to a separate journal bearing sleeve on the common axle via a radially offset camera tray such that the centerline of the camera is parallel to the axle, but the entire center of gravity of the module and tray is displaced from the axle. In this way the gravitational force on the overall assembly will keep the camera module vertically aligned as the cage skid assembly is propelled along the piping. Similarly the cage skid is fastened to the common axle by another journal bearing sleeve so that the skid is free to rotate on the axle separately so as to readily negotiate bends and around obstacles in the piping segment in which it is inserted. 
     A third embodiment in accordance with the present disclosure is designed for large diameter piping systems such as those having a diameter greater than 18 inches. In this embodiment each of the three ribs is fitted with a frame extension that supports two spaced wheels. Thus the cage skid is supported on three frame extensions each having a set of wheels. The cage skid then rolls along the inside pipe wall. Each end of the frame extension may be quickly attached or detached from the skid rib via a couple of bolts that sandwich the rib therebetween. 
     A fourth embodiment in accordance with the present disclosure is designed for essentially small/moderate diameter piping systems within a range of between 4-10 inches. In this embodiment the skid cage takes the form of a unitary cylindrical can shaped housing having an open front portion, a tubular mid portion and a cup shaped rear portion. The camera is again mounted for rotation on a shaft within the housing. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a composite of a side view, front and rear end views and several perspective views of a first embodiment of a camera skid assembly in accordance with this disclosure. 
         FIG. 2  is a composite of a side view, front and rear end views and several perspective views of a second embodiment of a camera skid nozzle assembly in accordance with this disclosure. 
         FIG. 3  is a perspective view of an assembled skid as shown in either  FIG. 1 or 2  with wheeled extensions on each of the skid ribs. 
         FIG. 4  is a perspective view of a further camera skid assembly for use in small to moderate pipe diameter systems. 
         FIG. 5  is an exploded perspective view of the assembly shown in  FIG. 4 . 
         FIG. 6  is a longitudinal sectional view of the assembly of  FIGS. 4 and 5  taken along the line  6 - 6  in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  includes several views of a first embodiment  100  in accordance with the present disclosure. Skid nozzle assembly  100  includes a camera module  102  mounted on a camera tray  104  that is rotatably supported from an axle  106  that extends through one end of a cage skid  108 . The cage skid  108  is, in turn, fastened to a tractor nozzle  110  that is attached to an end of a high pressure hose (not shown). Such a hose may be pressurized to somewhere between 100 psi to 20000 psi, depending on the service for which it is designed. The cage skid  108  is preferably made of a central bearing sleeve having three or more radially extending ribs  112  that extend outward from the central bearing sleeve and bend so as to extend parallel to the central bearing sleeve to a point beyond the camera tray. These ribs  112  then reconnect around the camera module  102  so as to present a protective cage structure around the camera module  102 . This axle  106  supports the cage  108  and also the camera tray  104 . The axle  106  extends axially from a tractor nozzle  110  that may have a plurality of rearwardly directed nozzle tips  114  to provide a forward thrust on the skid  108  so as to at least assist in driving the skid through a length of pipe in a piping system such as a sewer line. The cage skid  108  also preferably has a set of three or more radial support struts  116  that extend outward to support the axially extending portions of the ribs  112 . 
       FIG. 2  shows a second embodiment of an assembly  200  in accordance with the present disclosure. Nozzle skid assembly  200  includes a camera module  202  mounted on a camera tray  204  that is rotatably supported from an axle  206  that extends through one end of a cage skid  208  that is, in turn, fastened to a rotary bearing  210  in turn mounted to a rotary nozzle  222  and to a switcher tractor nozzle  214  such as is disclosed in U.S. Patent publication No. 20120205405 mentioned above. This switcher tractor nozzle  214  is then attached to an end of a high pressure hose (again, not shown). Such a hose may be pressurized to somewhere between 100 psi to 20000 psi, depending on the service for which it is designed. The cage skid  208  is preferably made of a central bearing sleeve  216  on the axle  206 . The sleeve  216  also has three or more radially extending ribs  218  that extend outward from the central bearing sleeve  216  and bend so as to extend parallel to the central axial bearing sleeve  216  to a point beyond the camera tray  204 . These ribs  218  then reconnect around the camera module  202  so as to present a protective cage structure around the camera module  202 . This axle  206  rotatably supports the cage skid  208  and separately the camera tray  204  such that it can freely rotate. A set of three radial struts  220  each extends from the sleeve  216  to one of the ribs  218  to provide rigid support for the cage assembly  208 . The axle  206  extends axially from a rotary bearing  210  that may optionally be in turn connected to a rotary cleaning jet nozzle  222  and another nozzle  212 . This nozzle  212  is then connected to the switcher tractor nozzle  214  that includes both cleaning and a plurality of rearwardly directed nozzle jet tips to provide a forward thrust on the skid so as to at least assist in driving the skid through a length of pipe in a piping system such as a sewer line. 
     In both of these embodiments described above, the camera module  102 ,  202  is preferably mounted to a separate journal bearing sleeve on the common axle  106 ,  206  via a radially offset camera tray  104 ,  204  such that the centerline of the camera is parallel to the axis of the axle  106 ,  206 , but the entire center of gravity of the module and tray is displaced from the axle. In this way the gravitational force on the overall assembly will keep the camera module vertically aligned as the cage skid assembly is propelled along the piping. Similarly the cage skid  108 ,  208  is fastened to the common axle  106 ,  206  by another journal bearing sleeve  124 ,  216  so that the skid  108 ,  208  is free to rotate separately on the axle  106 ,  206  so as to readily negotiate bends and around obstacles in the piping segment in which it is inserted. 
     A further embodiment of the camera skid assembly in accordance with the present disclosure is shown in a perspective view in  FIG. 3 . This skid assembly  300  incorporates a skid assembly as described above with reference to  FIG. 1 or 2  for use in large diameter piping systems, such as for deploying the skids  100  and  200  in pipes greater than about 18 inches in diameter. 
     Skid assembly  300  includes one of skids  100  or  200  and a set of three wheeled frame extension assemblies  302 . Each frame extension assembly includes a pair of elongated side plates  304 , a front wheel  306  and a rear wheel  308 . The pair of side plates  304  are fastened to and sandwich therebetween one of the ribs  112 ,  212 . The side plates  304  also sandwich and support axles  310  for the wheels  306  and  308 . 
     Each of the extension assemblies  302  is clamped to its rib  112 ,  212  via two bolt holes  312  and pairs of bolts and nuts (not shown). One of each pair of bolts in the holes  312  is threaded through the interior space of the rib  112 ,  212  and the other outside the rib  112 ,  212  so as to capture the rib  112 ,  212  between the side plates  304  and each pair of bolts. This clamping technique is exemplary. Other fastening techniques may be utilized, that are known, to secure each of the extension assemblies  302  to the skid  100 ,  200 . 
     A fourth embodiment of a camera skid assembly  400  is shown in  FIGS. 4-6 . This assembly  400  is similar to those assemblies  100  and  200  in that all carry a rotatably mounted camera assembly  102 . In this embodiment  400 , however, the cage  402  is of reduced size such that the assembly can be utilized in piping/conduit systems having a diameter between, for example, 4-10 inches. In this embodiment, the cage  402  is essentially a hollow can structure having a cup shaped open front cage portion  404 , a straight tubular mid portion  406 , and a cup shaped rear cage portion  408 . An axially centered tubular bearing sleeve  410  is fixed to and extends rearward from the rear cage portion  408 . Bearing sleeve  410  may be welded in place on the rear cage portion  408  or otherwise fastened thereto. 
     The rear cage portion  408  is rotatably fastened to a tractor nozzle  110  via the bearing sleeve  410  and an axle bolt  412  that extends through a pair of bushing bearings  414  in the bearing sleeve  410 . The axle bolt  412  is threaded into the head end of the tractor nozzle  110 . Operation of the tractor nozzle  110  is as previously described above. 
     Preferably the mid cage portion  406  is welded to or otherwise fastened to the rear cage portion  408  prior to assembly of the camera module into the rear cage portion  408 . The rear cage portion  408  and the mid cage portion  406  each preferably has at least one opening  416  to permit access to camera module controls. 
     The head or front cage portion is a hollow cup shaped solid body that has a central opening through which the camera can see down the piping system into which the assembly is inserted. Fixed to an interior surface of the front cage portion  404  is a generally rectangular weight block  420 . This weight block  420  provides the mass to keep the camera assembly  102  and the cage  402  properly aligned due to gravity as the skid  400  is pushed by the tractor nozzle  110  along a pipe in which it is deployed. 
     The camera assembly  102  is removably fastened to the mid cage portion  406  so as to rotate with the cage  402 . The mid cage portion  406  has a pair of diametrically opposed slotted flanges  424 . The camera assembly  102  has opposing flanges  426  which slide into and onto the flanges  424  as is shown in the assembled view of  FIG. 4 . In this way the camera assembly  102  is sandwiched between the mid cage portion  406  and the front cage portion  404 . During assembly, first the rear cage portion  408 , with mid cage portion fixed thereto, is assembled via the axle bolt  412  to the tractor nozzle  110 . Then the camera assembly  102  is slipped into the mid cage portion  406  such that the flanges  424  and  426  overlappingly engage and the weight block  420  slides beneath the camera assembly  102 . Finally, the front cage portion  404  is fitted to the rear and mid cage portions  406  and  408  so that a capture bolt  422  aligns with a threaded recess in the weight block  420 . The capture bolt  422  carried by the rear cage portion  408  is then threaded into the weight block  420  to draw the cage portions  408  and  404  together to complete the assembly. 
     When fully assembled, the cage  402  can rotate freely about the bearing axle  412 . When held horizontal as is shown in  FIG. 6 , gravity will locate the weight block  420  downward thus properly orienting the camera  102  within the cage assembly  402 . In this embodiment the weight block  420  orients both the camera  102  and the cage  402  itself together in order to produce an erect image from the camera assembly  102 . Preferably the flanges  424  and  426  are sized such that they do not protrude substantially beyond the side wall of the tubular mid cage portion  406  so that interference with proper orientation of the assembly  400  and snagging is minimized during deployment. 
     Alternatively a combination of a switching valve such as disclosed in U.S. Pat. No. 8,667,987 could be connected in tandem with a rotary cleaning nozzle  212 , and nozzle  212  may include a rotational speed limiting device such as a viscous damper as disclosed in U.S. Pat. No. 5,964,414 in order to maintain nozzle rotational speeds within a desired range. Other configurations could also be used. For example, rotary bearings  210  may be incorporated between the tandem components, and additional tractor nozzles may be incorporated into the component string of the assembly other than is specifically described and shown in the accompanying figures as may be needed for an encountered piping system being explored. 
     All such changes, alternatives and equivalents in accordance with the features and benefits described herein, are within the scope of the present disclosure. Such changes and alternatives may be introduced without departing from the spirit and broad scope of my invention as defined by the claims below and their equivalents.