Abstract:
A self-aligning apparatus comprising a ball bearing assembly mounted on a base plate and supporting an axle on which is mounted a video camera. In response to the force of gravity, the axle rotates such that the camera maintains a line-of-sight parallel to the cable of a crane or similar heavy equipment such that the video camera constantly views the work site of the hook element of the equipment. The equipment operator can view in real time images transmitted by the camera there reducing dependency on ground observers and improving safety.

Description:
[0001]    This application claims priority of U.S. Provisional Patent Application No. 60/318,980 filed Sep. 13, 2001 by Jason W. Peeples. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention is directed towards a device to position a camera so as to allow operators of certain types of heavy construction equipment to view directly a potentially obscured work site. More specifically, it is an apparatus to continuously align a camera with the vertical axis of the cable element of a crane with the view directed to the hook element on the cable, thereby allowing the operator to view directly the position of the hook in relation to a load and the surrounding work site when it might otherwise be out of the operator&#39;s line-of-sight. A further purpose of the invention is recording a real time record of the operation of a crane for safety records.  
         BACKGROUND OF THE INVENTION  
         [0003]    Cranes are used to lift, move, and position loads of over 300 mT. To avoid injury to workers and damage to both the load being moved and other structures and equipment, operators depend on observers to signal how, when, and where to move loads.  
           [0004]    Two major elements of a crane, in addition to the power source, are the boom and cable. The boom is attached at its base to a platform and is capable of being raised by elevating the opposite end, by increasing the angle between the boom and the platform. The length of the boom and the angle to which it can be elevated determine the height to which the crane can lift a load within its design capacity. A heavy extendable/retractable cable is supported by the boom and actually connects the load to the boom by means of a hook or other device. The boom and integrated cable, supports, and pulleys are connected to base, or platform that includes the operator&#39;s station. The base of many cranes is rotatable, frequently in a full circle.  
           [0005]    The cable and hook extend from the distal end of the boom, and in response to gravity unless physically prevented, the cable assumes an attitude vertical to the earth&#39;s surface. It is important to position the boom such that the cable is directly over a load so that the cable is at right angles to minimize potential harm arising from dragging the load.  
           [0006]    If a load is not directly under the distal end of the boom, as the load is lifted, the load may be damaged by dragging as gravity forces the cable to its natural vertical position. As the load is lifted, the load may swing, potentially damaging its surroundings or injuring workers. Uncontrolled movement of the load may also damage the crane itself. Similarly, it is important to visually follow the load as it is moved and unloaded or disconnected from the cable.  
           [0007]    Safety of operation of the lifting equipment depends to a significant extent on the Operator&#39;s view of the work site; the point a which a load will be connected and lifted, the path through the load will be moved by the boom, and the point at which the load will be delivered and the position in which it is to be placed.  
           [0008]    Because of obstructions and similar conditions, crane operators frequently cannot directly view the site at which a load is to be picked-up, deposited, or the entire area through which the load is to be moved. As a result operators frequently dependent upon ground observers, or flagmen to indicate by common hand signals the location of the hook relevant to the load so that the hook can be properly connected to the load. Hand signals are used to guide the movement of the load and to position the load properly at its destination point. Delays in the flagman finding an appropriate position from which to signal, delays in signaling, misunderstandings in visual or oral communications may delay moving construction activities, may result in damage to the material to be moved or to structures adjacent, or most seriously, incorrect, misinterpreted, or delayed signals can result in serious injuries to the flagman, or to other workers. Accordingly, there remains room for variation and improvement in the art related to safety of certain construction equipment.  
         SUMMARY OF THE INVENTION  
         [0009]    A purpose of the invention is a vertically self-aligning apparatus that responds to changes in the angle of elevation of the boom of a crane so as to maintain the field of vision of a camera mounted on the apparatus, in a constant, vertical plane parallel to the cable of the boom providing a view of the work site and hook element of the crane. The invention includes a video monitor with video recording capabilities to preserve images transmitted by the video camera. An axle is rotatably connected by its proximal end to a ball bearing assembly, and the ball bearing assembly is attached to a base plate. The base plate connects the entire apparatus to the boom structure of a crane. The camera is enclosed in a box-like, frame structure and may be protected by a compressible material. The camera is positioned in the frame so as to have an unobstructed line-of-sight from the frame structure. The frame structure with the enclosed camera is physically attached to the distal end of the axle at a point above its center of gravity such that the line-of-sight of the camera is vertically downward, parallel to the crane&#39;s cable and includes the hook element of the cable. As the angle of elevation of the boom changes, the line-of-sight of the camera remains vertical to the earth&#39;s surface and parallel to the cable as a result of the axle in conjunction with the ball bearing assembly rotating in response to gravity, the response being a direct function of the location of the point of attachment of the frame structure and axle. Images are transmitted to a monitor convenient for viewing by the operator of the crane. The monitor may include means to record the transmitted images. The ability to view directly the cable, hook, and work-site reduces dependency on and inadequacies of ground observers, thereby reducing the danger of injuries and damage to materials and equipment and increasing the efficiency of operation of the equipment.  
           [0010]    These and other features, aspects, and advantages of the present invention will become better understood with reference to the following figures, descriptions, and appended claims 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 illustrates on the boom of a crane in which the self-aligning apparatus may be located, the boom, cable, and camera line-of-sight.  
         [0012]    [0012]FIG. 2 A illustrates the basic camera unit including the frame structure and camera.  
         [0013]    [0013]FIG. 2B illustrates the basic camera.  
         [0014]    [0014]FIG. 2C provides detail of a camera positioned in the camera frame.  
         [0015]    [0015]FIG. 2D provides detail of the camera frame structure.  
         [0016]    [0016]FIG. 3A provides several views of the device illustrating the relationship among major components including the camera unit, axle, bearing assembly, and base plate.  
         [0017]    [0017]FIG. 3B provides details of a magnet positioned in the base plate to serve as a means of securing the base plate to the boom.  
         [0018]    [0018]FIG. 4 provides details of an alternative base plate.  
         [0019]    [0019]FIG. 5 illustrates a mechanical means to adjust the center of gravity of the camera unit.  
         [0020]    [0020]FIG. 6 illustrates a complex, multi-component, extendable axle with gear and power means to extend and retract an interior axle element.  
         [0021]    [0021]FIG. 7 illustrates an optional source of illumination of the work site to ensure at least minimal light for camera operation.  
         [0022]    [0022]FIG. 8 illustrates a first alternative assembly of the apparatus.  
         [0023]    [0023]FIG. 9A illustrates a side view of a second alternative assembly of the apparatus.  
         [0024]    [0024]FIG. 9B illustrates a top view of the second alternative assembly of the apparatus illustrated in FIG. 9A. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENT  
       [0025]    Reference now will be made to preferred embodiments, one or more examples of which are set forth below. The examples are provided by way of explanation of the invention, not as limitations of the invention. One skilled in the art will readily recognize that modifications and variations of the present invention can be made without departing from the scope and purpose of the invention. Specific features described for individual embodiments can be combined to yield additional embodiments; thus, it is intended that such combinations and modifications are within the scope of the appended claims and their equivalents. The following detailed description presents other objectives, features, and aspects of the present invention. One of ordinary skill in the art will recognize the present description of exemplary embodiments only, not as limiting broader aspects of the present invention that are embodied in the exemplary constructions.  
       EXAMPLE 1  
       [0026]    In describing the various figures, the same reference numbers are used consistently to identify the same element, part, or aspect of the invention. Once described in relation to a figure, detailed descriptions of an element, part, or aspect of the invention are not repeated, although reference numbers may appear in several figures.  
         [0027]    As illustrated in FIG. 1, the self-aligning apparatus  1  is located  2  near the fly tip (proximal end)  3  of the boom  5 . The cable  7  extends vertically downward from the fly tip  3  and extends from a heavy-duty take-up drum  15 . The boom  5  and other unidentified elements support the cable and enable the angle of inclination of the boom to be changed. The self-aligning apparatus  1  is located  2  at or near the fly tip  3  and positioned to afford an unobstructed line-of-sight  11  downward from the apparatus. The line-of-sight  11  from a camera in the camera unit  20  is vertically downward and parallel to the cable  7 . The field of vision  14  of a camera in the camera unit is centered in the line-of-sight  11  and is conical in geometry, such that it includes the hook  12  attached to the cable  7  and load  13 . One of average skill in the art recognizes that for cranes equipped with a jib assembly, the distal end of the jib assembly would correspond to the fly tip of the boom.  
         [0028]    As illustrated by a cross section diagram, FIG. 2A, the camera unit  20  comprises two major elements: a video camera  21  and a frame structure  22 . The video camera is an electrically powered instrument capable of transmitting images to a monitor. Cameras of this type and varying in complexity are commercially available. See for example B&amp;H PhotoVideo-ProAudio, 420 Ninth Ave., New York City, N.Y. 10001. The frame structure  22  is a box-like unit designed to encase and protect the video camera  21 .  
         [0029]    A wide variety of available video cameras may be adapted for this purpose. FIG. 2B illustrates diagrammatically minimum basic parts of the video camera  21 . The two major parts are the camera lens system  23  and the camera body  24 . One of average skill in the art understands technical aspects of a video camera, as well as its basic function and operation. Specific details as to size, shape, and weight of the camera are significant factors only to the extent that they must be known in order to fabricate an appropriate frame structure  22 . The frame structure  22  supports the camera and provides the physical connection between the camera unit  20  and axle  40  as illustrated in FIG. 2D.  
         [0030]    [0030]FIG. 2C illustrates details of the major parts and organization of the frame structure as they relate to these functions. The frame structure  22  comprises a box-like unit with a top piece  25 , a bottom piece  26 , the bottom piece  26  having an opening  27  located and positioned so that the camera lens  23  has an unobstructed line-of-sight from the frame structure  22 . The frame structure further comprises sidepieces  28  a back piece  29 , and a front piece  30  shown in FIG. 2D. The common edges of the top piece  25 , side pieces  28 , bottom piece  26 , and back piece are securely joined as illustrated in FIG. 2C. The front piece  30  provides access to the interior  31  of the box-like unit and the video camera  21  enclosed therein. The front piece  30  contacts edges of the top piece  25 , side pieces  28 , and bottom piece  26  and is connected to these elements of the frame structure by hinges  34  positioned along one edge with a secure latch  36  on the opposite edge or by threaded fasteners joining the front piece  30  to the sides it contacts. A compressible material such as or sponge rubber covers and is adhesively bonded to the inner surfaces  31  of the top piece  25 , the side pieces  28 , the bottom piece  26 , and the front piece  30 . When the camera  21  is properly positioned in the frame structure  22 , the lens  23  is centered in the opening  27  in the bottom piece  26 .  
         [0031]    When the front piece  30  is properly positioned and secured, the front  30  and back  29  pieces hold the camera in position. One skilled in the art will recognize that, depending on The shape of the camera, additional compressible material may be required to support the camera along any internal surface of the frame structure. Such additional padding does not alter the fundamental nature, scope, or intent of the invention. The frame structure may be fabricated from a wide variety of lightweight materials. Aluminum is a suitable material, but other metals, alloys, and synthetic materials are acceptable. As illustrated in FIG. 2C, the top, bottom, side, and front pieces are solid. The invention anticipates the use of strips of materials to fabricate each piece as an open center, frame-like rectangle without modifying the nature, scope, or intent of the invention.  
         [0032]    [0032]FIG. 2D illustrates the camera unit  20  attached to the axle at a rotational point  35  on the back piece  29 . The point is located vertically above the center of gravity of the camera unit and positioned horizontally such that, from any initial point with the axle  40  freely rotating, a line passing vertically through the lens  23  representing the center of the line-of-sight of the camera is vertical to the horizontal plane and will remain with this orientation in response to rotation of the axle  40  as the angle of elevation of the boom  5  of FIG. 1 is changed.  
         [0033]    To determine the proper point of attachment of the axle to the camera unit, the center of gravity must be located with respect to the surface of the back piece  29  when the camera is positioned properly in the frame structure. The laws of physics define the center of gravity as the point at which the force of gravity is considered to act. The center of gravity can be determined analytically following laws well known in physics, but it is easier and more practical to determine this point experimentally. See for example, Giancoli, D.C., Physics Principles with Applications, 5th ed. Prentice Hall, Upper Saddle River, N.J. chapter 7, which chapter 7 is by reference herein incorporated in its entirety.  
         [0034]    Experimentally, the center of gravity of an object is described as the intersection of two or more lines each of which passes from independent points on the surface of the object in a path vertical to the horizontal plane. If the center of gravity is on a line vertical to the horizontal plane and directly below a pivot point, the body will not rotate. If the line is not vertical to the horizontal plane, in the absence of mechanical interference, the object will rotate in response to the force of gravity until the vertical relationship is established. See for example Giancoli, D.C., Physics Principles with Applications, 5th ed. Prentice Hall, Upper Saddle River, N.J., which text is by reference herein incorporated in its entirety.  
         [0035]    [0035]FIG. 3 illustrates the fundamental elements of the rotational unit  100  (base plate  60 , axle  40 , and sealed bearing assembly  50 ) and its relationship with respect to the camera unit  20 . The proximal end  42  of an axle  40  is tightly pressed into the bore  52  of a sealed bearing assembly  50 . A bearing hub receptacle  51  is machined into the base plate  60 , and the sealed bearing assembly  50  including the axle  40  is tightly pressed into and held securely by the bearing hub receptacle  51 . As illustrated in cross section FIG. 3B, the bearing hub receptacle  51  is shaped such that the sealed bearing assembly  50  cannot be forced through the bearing hub receptacle  51 . One of average skill in the art understands how the sealed bearing assembly  50  is pressed onto the axle  40  and how the sealed bearing assembly with the axle in pressed into and held by the bearing hub receptacle  51 .  
         [0036]    The back face  59  of the base plate  60  is attached to the boom at a point  2  on the fly tip  3  as diagramed in FIG. 1. Various methods may be used to attach the base plate to the boom. Mechanical clamps well known in the art and magnets do not require manufacture approved installation; whereas welding or drilling and bolting through the boom structure to secure the base plate to the boom may require such special installation for safety of the boom structure. FIG. 3B illustrates the back side  59  of the base plate  60  with a magnet positioned in the back surface as a circular structure circumscribing the bore  52 . The base plate may be machined or molded to receive the magnet, and the magnet may be held in position by a variety of means including bolts, rivets, or special adhesives.  
         [0037]    The axle  40  rotates freely with the inner race  57  of the bearing assembly  50 . The Outer race is held securely, positioned in the bearing hub receptacle  51  and does not rotate. The distil end  41  of the axle  40  is attached at a point  32  on the back face  29  of camera unit frame structure  22 .  
         [0038]    The base plate  60  is most commonly made of a metal, such as aluminum with a magnet  66  for mounting the base plate on the boom positioned in the back side  59  of the base plate  60 . The shape is not limiting and can be modified for convenience to fit a specific point on a given boom. Specific dimensions are given as illustrations, not as limitations. Rectangles approximately 15 cm×15 cm are suitable. Minimum thickness of the base plate is determined by the minimum depth of the sealed bearing hub assembly  51 , which in turn is determined by the width of the sealed bearing assembly. By way of illustration, not limitation, minimum depths of 0.5 cm to 1.5 cm are appropriate for bearing assemblies with corresponding thickness. These thickness are increased to allow positioning of a magnet as the desired means to attach the base plate to the boom of the crane.  
         [0039]    Sealed bearing assemblies similar to those commonly used in the automotive industry are readily available from a variety of commercial sources. Dimensions of appropriate bearing assemblies for the preferred sealed bearing assembly, include, in addition to depth, outer diameter, which determines the diameter of the bearing hub receptacle and inner (bore) diameter. Dimensions of appropriate bearings in addition to width range by way of example from about approximately 1.00 cm to 5.00 cm bore diameter and 3.00 cm to 10.00 cm out side diameter. Suitable bearings are available through SKF, Chicago Rawhide, Elgin, Ill. 60123.  
         [0040]    The axle is generally steel, although other materials are acceptable so long as they are adapted to having the sealed bearing assembly pressed on to them. The diameter is a function of the diameter of the bore of the sealed bearing assembly, assuming the axle is of adequate size to support the camera unit. Diameters range from 0.50 cm to 5.00 cm. The length of the axle varies from 10 cm to 100 cm. The major cause for variation is to allow the camera unit to be positioned with an unobstructed line-of-site on the boom. One skilled in the are recognizes that dimensions of the sealed bearing assembly and diameter of the axle increase as the weight of the camera unit increases and as the length of the axle increases. However acceptable dimensions can be determined without excessive experimentation.  
         [0041]    An electric heating element  65  controlled by a thermostat (not shown) may be positioned around or against the sealed bearing  50  or optionally an electric heating element can be used to heat the entire base plate  60 , including the sealed bearing. Such optional heating helps to ensure that low ambient temperatures do not increase the viscosity of the sealed bearing lubricant thereby inhibiting its free rotation and vertical alignment of the camera as the elevation of the boom changes.  
         [0042]    One skilled in the art recognizes that a sealed bearing assembly, although convenient is not essential. Other commercially available bearing assemblies are anticipated by the invention. In addition, one skilled in the art recognizes that the base plate  60  may be fabricated in two sections as shown in FIG. 4, a base and a bearing hub receptacle attached to the base, commonly by welding.  
         [0043]    Because the axle rotates in conjunction with the bearing assembly, the point of attachment  35  of the axle  40  to the frame structure  22  constitutes the pivot point for the camera unit and for the camera that structure supports. For the camera constantly to face vertically downward, an appropriate point of attachment of the axle to the camera unit which point in practice is the back piece  29  of the frame structure at a point above the center of gravity on a line vertical to the horizontal plane when the line, if extended to the line-of-sight of the camera, would be the same as the line of sight of the camera.  
         [0044]    [0044]FIG. 5 illustrates a mechanical means to effectively lower the center of gravity of the camera unit  20 . A stud piece  70  is threaded into the axle  40  on a radius of the axle  71  such that the vertical centerline of the stud piece  72  is parallel to the line-of-sight  11  of the camera  21 . One skilled in the art recognizes that this relationship is readily achieved by first positioning the stud piece  70  and then aligning the camera unit  20  and attaching it to the axle  40  as previously described. A weight  73  is threaded to the distal end  74  of the stud piece  70 . The stud piece  70  and attached weight  74  act in a pendulum-like fashion causing the axle to rotate in response to the force of gravity as the elevation of the boom is changed. Given the vertically parallel planes of the camera line-of-sight and the stud piece and weight, the desired line-of-sight is assured and maintained.  
         [0045]    [0045]FIG. 6 A illustrates a mechanically extendable axle unit  81  comprising an outer sleeve  82 , longitudinally hollow element  83  with a proximal end  84  and a distal end  85 . A flange  86  is formed at the proximal end  85 .  
         [0046]    The outer face  87  of the flange  86  contacts and is fixed to the face  88  of an electric motor  89 . A longitudinally hollow inner sleeve  90  with a distal end  91  and a proximal end  92  is inserted into the outer sleeve  82 . The camera unit  20  as previously described is attached to the distal end  91  of the inner sleeve  90 .  
         [0047]    A worm gear travel means  93  is attached near the proximal end  92  to, and centered in the longitudinal hollow core  94  of the inner sleeve  90 . The worm gear travel means  93  comprises structural supports  94  and a nut structure  95  with a threaded aperture  96 .  
         [0048]    A threaded axle unit  97  with a distal end  98  and a proximal end  99  is threaded through the nut structure  95 . The proximal end  99  is mechanically connected to the drive shaft  100  of the electric motor  88 .  
         [0049]    The outer sleeve  82  is pressed into the bearing assembly  50 . The inner face  101  of the flange  86  contacts the bearing assembly  50  and limits the depth of insertion. The bearing assembly  50  with the inserted extendable axle unit  81  is pressed into the bearing hub receptacle  51  and secured by mechanical means, such as a pin or set screw.  
         [0050]    [0050]FIG. 6B provides details of the worm gear travel means  93 , with four support elements  94  supporting the nut structure  95  with its threaded aperture  96 . The support elements  94  are attached at points  102  on the inner surface of the inner sleeve such that the nut structure is centered in the longitudinally open core  103  of the inner sleeve  90 . The camera unit  20  is attached at a point  32  to the distal end  91  of the inner sleeve  90 .  
         [0051]    The threaded axle unit  97  is directly coupled to and rotates with the drive shaft  100  of the electric motor  89 . At least one key  104  is positioned longitudinally along the length of and fixed to the outer surface of the inner sleeve  90 . The key  104  fits into a longitudinal groove  105  formed along the length of the inner surface of the outer sleeve.  
         [0052]    The key  104  when positioned in the slot  105  prevents the inner sleeve from rotating with the threaded axle because the outer sleeve is anchored by the bearing assembly  50 . Thus, when the threaded axle rotates with the motor drive shaft in one direction, the inner sleeve moves in one direction, and when the motor rotation is reversed, the inner sleeve moves in the opposite direction. The electric motor is reversible and controlled by a switch convenient to the equipment operator. Stop devices at each end of the threaded axle prevent over extension or retraction of the threaded axle. A pendulum device as described with respect to FIG. 5 may be positioned on the outer sleeve.  
         [0053]    The relationships among certain major components of the extendable axle are summarized in FIG. 6C. The camera unit  20  is attached at a point  32  to the inner sleeve  90 . The threaded axle  97  is coupled to the drive shaft  100  of a small, reversible electric motor  89 . The outer sleeve  82  is connected by a flange face  87  to the motor to the gear assembly  50  by the opposite side of the flange.  
         [0054]    [0054]FIG. 7 illustrates a source of illumination  120  of the work site attached to the camera unit  20 . As illustrated, the source of illumination is attached to the front surface of the camera unit. One skilled in the art recognizes that the source of illumination could be attached to other positions on the camera unit  20  without changing the scope of the invention. The point of attachment is below the center of gravity of the camera, or is compensated for by the stud piece  70  and weight  73  as described for FIG. 5. The source of illumination comprises at least a base plate  121  or means by which the source of illumination may be attached to the camera unit or otherwise to the device. A light receptacle  122  is attached to the base plate  121 . The receptacle is threaded to receive and wired to permit the normal operation of a high intensity electric light bulb  123 . The receptacle is appropriately insulated to prevent short circuits and related problems. The bulb  123  is encloses in a reflector unit  124  that includes a lens system  125  directs the light to the work site. The light is directed and focused along the same vertical plane as the line-of-sight of the camera. The receptacle  122  is electrically connected  126  to the power source of the equipment on which it is mounted.  
       EXAMPLE 2  
       [0055]    [0055]FIG. 8 illustrates a first alternative arrangement of the rotatable parts of the apparatus  2 . The distal end  203  of the axle  40  is firmly anchored to a point  201  on the boom  5  near the tip of the boom  3 . The bearing hub receptacle  51  is attached to one side of the frame  22  and the sealed bearing assembly  50  is positioned as previously described. The proximal end  202  of the axle  40  is positioned in the bore  52 . In this configuration, the axle is fixed and does not rotate, but the camera unit  20  rotates. To foster rotation additional weights  204  may be positioned in the base of the frame  22 .  
       EXAMPLE 3  
       [0056]    As illustrated in FIG. 9B, the self-aligning apparatus  1  is positioned immediately in front of and above the tip of the boom  5  rather than to the side of the boom  5  and cable  7  as illustrated in previous examples. The rotational assemble in this example comprises two base plates  60 A and  60 B, each of which has an accompanying sealed bearing assembly  52 A and  52 B. The axle  40  passes horizontally through the upper half of the frame structure  91  (in FIG. 9A) well above the center of gravity of the complete camera unit, and the axle  40  and frame structure are connected such that the frame structure cannot rotate around the axle. One end of the axle is pressed into the bore of one sealed bearing assembly and the opposite end of the axle is pressed into the bore of the other sealed bearing assembly. Support brackets  91 A and  91 B are firmly attached to opposite, exterior sides of the boom  5  near the tip  94 . Base plates  60 A and  60 B are attached securely to the boom on each side. As the angle of the boom changes, the axle rotates and the camera positioned in the frame structure rotates to maintain the vertical line-of-sight  11  as previously described.  
       EXAMPLE 4  
       [0057]    This feature is common to all of the preceding examples. For operational safety of the crane, power is delivered to shutoff switches located on the boom assembly, and as required on the jib assembly. The switches prevent over elevation of the boom or jib. Commonly, electrical plug units connect a main electrical service line to the shutoff switch. Safety considerations mandates that the security of these plugs be maintained. Power to operate the camera, extendable axle, and light is also provided by the main electrical service line. To ensure security of the plug units, a locking T-splice plug is inserted between the female and male elements of the plug unit. If the camera is separately powered from the electrical system of the crane, the T-splice plug is not necessary.