Patent Publication Number: US-7584704-B2

Title: Assembly for aligning and interlocking an electro-monorail system and vertical lift station

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to electro-monorail systems (EMS) that interact with vertical-lift-stations (VLS), and more particularly to an assembly for aiding the alignment of and interlocking the EMS and VLS in a fixed condition. 
     2. Discussion of Prior Art 
     Electro-monorail systems (EMS) have been developed to facilitate the assembly, fabrication and inventory of a multi-step multi-nodal process. In the automotive industry, for example, EMS are frequently utilized to facilitate the stamping, welding, painting, or general assembly processes of an auto-body work in progress. These systems utilize a main rail to interconnect a plurality of nodes, and support a carrier that is propelled from node to node by continuous electric potential within the rail. As such, the load carrying main rail includes a series of conductive slats and shoes followed by a grounding slat. The carrier includes a series of front and rear bushings for receiving the oscillating electric current, and wheels which rollingly engage raceways defined by the main rail. Where overhead EMS configurations are provided, each node typically features a vertical lift station (VLS) that translates into and out of an operable position, wherein a VLS rail is positioned adjacent the EMS main rail. Once in position, the carrier is able to travel upon the VLS rail, so as to be lowered within the work cell. Finally, when the work is complete, the VLS is raised to the operable position, so that the carrier can proceed to the next station. 
     The entry and exit of the carrier upon the VLS rail, however, present commonly experienced concerns caused by misalignment and/or deflection. More particularly, it is appreciated by those of ordinary skill in the art that as the carrier enters the VLS rail, the VLS descends a small yet significant dimension. This action by the VLS causes, among other things, the rear bushing of the carrier to drag on the main rail. By catching the end of the carrier, a downward force equal to the weight of the carrier and payload acts upon the end of the main rail. As a result, the relatively lightweight main rail, which is often formed of aluminum, may be caused to inelastically deform due to insufficient structural capacity. As the carrier exits the VLS, the descended configuration may cause the carrier to strike the EMS at the exit point, which may further cause inelastic deformation at the exit point. Meanwhile, the front and rear bushings of the carrier are often damaged from constant dragging and striking of the main rail. 
     Various measures have been implemented to structurally support and reduce misalignment and deflection at the EMS-VLS interface, including the addition of massive steel beams to reinforce the existing framework. These measures have achieved little success and have not been incorporated due to costs, work cell space, and inefficiency of operation. Instead, damaged EMS, VLS rail, and carrier components are typically allowed to undergo gradual degradation until replacement. 
     Thus, there remains a need in the art for an improved measure for reducing the likelihood of misalignment and deflection at an EMS-VLS interface, and the damages caused thereby. 
     BRIEF SUMMARY OF THE INVENTION 
     Responsive to this need, the present invention concerns an assembly for aiding alignment and interlocking a main rail of an EMS and a VLS rail. The assembly aids the proper alignment of the VLS rail as it translates into an operable position adjacent the main rail. The assembly further includes a clamping device for holding the main and VLS rails in a fixed condition, so as to reduce the likelihood of deflection during carrier translation on and off of the VLS rail. As such, the invention is useful for extending the useful life of the main rail, VLS rail, and carrier, and reducing repair and replacement costs associated therewith. 
     A first aspect of the present invention generally concerns the configuration of the assembly for aiding the alignment of the VLS rail and main rail, as the VLS translates into the operable position. In this regard, the assembly includes an elongated locator pin fixedly connected to the VLS rail at or near the interface, and presenting an average cross-sectional pin diameter. The assembly further includes a receiver fixedly connected to the main rail at or near the interface. The receiver includes a cradle having divergently tapered walls, so as to present a maximum cradle wall spacing at and a minimum cradle wall spacing opposite the distal end of the walls. The pin and receiver are cooperatively configured so that the pin diameter is less than the maximum cradle wall spacing and greater than the minimum spacing, and cooperatively positioned so that the pin enters the cradle and is funneled towards the minimum spacing as the VLS rail translates into the operable position. 
     A second aspect of the present invention concerns the configuration of the assembly for interlocking the VLS and main rails in a relatively fixed condition. In this regard, the assembly includes an EMS engaging structure fixedly attached to the main rail at or near the interface. The assembly also includes a VLS rail engaging structure fixedly attached to the VLS rail at or near the interface. Lastly, the assembly includes a clamping device configured to produce a holding force when the VLS rail is in the operable position and the structures are attached to the main and VLS rails. The clamping device is configured to apply the force to the EMS and VLS rail engaging structures, so that the main and VLS rails are biased towards and held in the fixed condition. 
     Yet further aspects, embodiments, and advantages of the present invention, including the use of a pneumatic power clamp having a toggle lock, and a magnetized pin and receiver combination, will be apparent from the following detailed description of the preferred embodiment(s) and the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       A preferred embodiment(s) of the invention is described in detail below with reference to the attached drawing figures, wherein: 
         FIG. 1  is a rearward isometric view of an aligning and interlocking assembly having a left swing arm in accordance with a preferred embodiment of the present invention, a partial segment of an EMS main rail, and a partial segment of a VLS rail; 
         FIG. 1   a  is a frontward isometric view of the assembly shown in  FIG. 1 ; 
         FIG. 2  is a rearward isometric view of an aligning and interlocking assembly having a right swing arm in accordance with a preferred embodiment of the present invention, a partial segment of an EMS main rail, and a partial segment of a VLS rail; 
         FIG. 2   a  is a frontward isometric view of the assembly shown in  FIG. 2 ; 
         FIG. 3  is left side elevation view of the assembly, partial EMS main rail, and partial VLS rail shown in  FIG. 1 , particularly illustrating a left swing arm clamping device, and a locator pin and pin holder fixedly attached to the VLS rail; 
         FIG. 3   a  is a top view of the assembly, partial EMS main rail, and partial VLS rail shown in  FIG. 1 ; 
         FIG. 3   b  is a rear elevation view of the assembly, partial EMS main rail, and partial VLS rail shown in  FIG. 1 ; 
         FIG. 3   c  is a right side elevation view of the assembly, partial EMS main rail, and partial VLS rail shown in  FIG. 1 , particularly illustrating a multi-section bracket interconnecting the clamping device and EMS main rail; 
         FIG. 3   d  is a top view of the assembly shown in  FIG. 1 , particularly illustrating the main and VLS rail interconnecting fasteners; 
         FIG. 4  is a front elevation view a locator pin in accordance with a preferred embodiment of the present invention; 
         FIG. 4   a  is a side elevation view of the locator pin shown in  FIG. 4 ; 
         FIG. 4   b  is a top view of the locator pin shown in  FIG. 4 ; 
         FIG. 4   c  is a top view of a locator pin in accordance with a preferred embodiment of the present invention, particularly illustrating a wire coil and a magnetically permeable core; 
         FIG. 5  is an isometric view of a VLS rail engaging pin holder adapted for interconnecting a locator pin and the VLS rail, in accordance with a preferred embodiment of the present invention; 
         FIG. 5   a  is a side elevation view of the pin holder shown in  FIG. 5 ; 
         FIG. 5   b  is a front elevation view of the pin holder shown in  FIG. 5 ; 
         FIG. 5   c  is a top view of the pin holder shown in  FIG. 5 ; 
         FIG. 6  is a front elevation view of a receiver cradle in accordance with a preferred embodiment of the present invention; 
         FIG. 6   a  is a side elevation view of the cradle shown in  FIG. 6 ; 
         FIG. 7  is a side elevation view of a receiver key for engaging the receiver cradle in accordance with a preferred embodiment of the present invention; 
         FIG. 7   a  is front elevation view of the key shown in  FIG. 7 ; 
         FIG. 8  is a top surface view of an EMS bracket/receiver mounting plate for interconnecting the receiver cradle and bracket to the EMS main rail in accordance with a preferred embodiment of the present invention, particularly illustrating a plurality of engaging holes and a cradle stop projection; 
         FIG. 8   a  is a side elevation view of the mounting plate shown in  FIG. 8 ; 
         FIG. 8   b  is a front elevation view of a partial assembly in accordance with a preferred embodiment of the present invention, wherein the cradle shown in  FIG. 6  is in a vertically fixed positioned defined by a receiver key shown in  FIG. 7  and the mounting plate shown in  FIG. 8 ; 
         FIG. 9  is a side elevation view of a swing arm in accordance with a preferred embodiment of the present invention; 
         FIG. 9   a  is a bottom view of the swing arm shown in  FIG. 9 , particularly illustrating the lift pad engaging holes; 
         FIG. 10  is a top view of a lift pad adapted for connecting to the swing arm and engaging the locator pin, in accordance with a preferred embodiment of the present invention; 
         FIG. 10   a  is a side elevation view of the lift pad shown in  FIG. 10 ; 
         FIG. 11  is left rearward isometric view of an EMS engaging structure (multi-section bracket) adapted for interconnecting the clamping device, receiver cradle, and EMS main rail, in accordance with a preferred embodiment of the present invention; 
         FIG. 11   a  is a right rearward isometric view of the structure shown in  FIG. 11 ; 
         FIG. 11   b  is a top view of the structure shown in  FIG. 11 ; 
         FIG. 11   c  is a front elevation view of the structure shown in  FIG. 11 , particularly illustrating the EMS main rail engaging section; 
         FIG. 11   d  is a left elevation view of the structure shown in  FIG. 11 , particularly illustrating the receiver engaging section; and 
         FIG. 11   e  is a rear elevation view of the structure shown in  FIG. 11 , particularly illustrating the clamping device engaging section. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As best shown in  FIGS. 1 and 2 , the present invention concerns an assembly  10  for aiding the alignment of and interlocking in a fixed condition a main rail  12  of an electro-monorail system (EMS) and a vertical lift station (VLS) rail  14 . The assembly  10 , as henceforth described and illustrated, is duplicitously added to the pre-existing EMS-VLS combination at each interface  16  (i.e., each point of entry and exit to each station) defined by the rails  12 ,  14 . Each assembly  10  provides additional structural rigidity at the interface, produces a holding force that acts to reduce deflection and recession during load transfer, and promotes the proper alignment of the VLS rail  14  as it translates to an operable position adjacent the main rail  12 . The assembly  10  is further configured so as not to obstruct the carrier travel zone ( FIG. 3 ). 
     Turning to the structural configuration of the illustrated embodiment, the assembly  10  generally includes a receiver  18 , a locator pin or rod  20 , and more preferably, a clamping device  22 . As shown in  FIGS. 1 through 3   d , the receiver  18  and locator pin  20  are cooperatively configured so that the locator pin  20  enters the receiver  18  as the VLS rail  14  is raised into the operable position. The locator pin  20  is fixedly attached to the VLS rail  14  at or near the interface  16 . As shown in  FIGS. 4 ,  4   a  and  4   b , the pin  20  presents an elongated member having a longitudinal length and a maximum cross-sectional diameter. The pin length is dimensioned in accordance with relative pin and receiver spacing, and more particularly to ensure that a sufficient portion (e.g., at least 25%) of the pin  20  is received by the receiver  18 . It is therefore preferable to abut the pin  20  and receiver  18  adjacent the interface  16  ( FIGS. 1 through 2   a ). The pin  20  presents an oblong cross-sectional shape ( FIG. 4 ) that defines a curvilinear upper receiver engaging surface  20   a , and flat structure and device engaging surfaces  20   b , which promote flush interaction therewith. As also shown in  FIGS. 4   a - b , the pin  20  defines at least one fastener receiving hole to facilitate interconnection. 
     The preferred assembly  10  includes a VLS engaging structure or pin holder  24  for interconnecting the pin  20  and VLS rail  14  ( FIGS. 1 and 2   a ). As shown in  FIGS. 5 through 5   c , the pin holder  24  presents an angle member having a VLS rail engaging leg  24   a , a device engaging leg  24   b , and a raised section  24   c  for added resistance to bending. As shown in  FIGS. 1 ,  2  and  3 , the pin holder  24  is configured to retain the pin  20  adjacent the angle defined by the raised section  24   c  and device engaging leg  24   b . To that end, the holder  24  defines two dowel receiving holes within the raised section  24   c  and a perpendicular through-hole within the device engaging section  24   b  ( FIG. 5   a ) for aligning with the pin  20  and receiving a plurality of removable fasteners  25  (typ.), such as bolts, plugs, dowels, etc. The remainder of the holes are defined by the VLS engaging section  24   a  and includes at least one dowel hole ( FIG. 5   a - b ) for connecting to the VLS rail. Thus, the device engaging and raised sections  24   b - c  are cooperatively configured to space the pin  20  from the VLS rail  14 , and provide a sufficient catch for engaging the clamping device  22 . 
     As shown in  FIGS. 6 and 6   a , the preferred receiver  18  includes a cradle  26  comprising two projecting side walls  26   a . The walls  26   a  define divergently tapered inner wall surfaces that cooperate to present a maximum wall spacing at and a minimum wall spacing opposite the distal end of the walls  26   a . The cradle  26  and pin  20  are cooperatively configured so that the maximum pin diameter is less than the dimension of the maximum spacing but larger than the minimum wall spacing. In this configuration, it is appreciated that the tapered configuration of the walls  26   a  acts to funnel the pin  20  towards the minimum spacing, thereby guiding the pin  20  and attached VLS rail  14  towards the alignment defined by the minimum spacing. In the illustrated embodiment, the minimum wall spacing further presents a seat  26   b  opposite the distal end of the walls  26   a . The seat  26   b  and pin  20  are cooperatively configured to form superjacent layers. More particularly, the seat  26   b  presents a curved surface having a lateral radius of curvature slightly greater than (e.g., 105%) the radius of curvature that defines the receiver engaging pin surface  20   a.    
     As assembled, the cradle  26  is adjacently positioned next to an EMS/receiver mounting plate  28 . At its base, the cradle  26  defines a notch  26   c  for receiving a receiver key  30 . More particularly, and as shown in  FIGS. 7 and 7   a , the receiver key  30  presents an elongated rectangular member having a key projection  30   a  configured to be inserted within the notch  26   c . The key  30  is oriented within the notch  26   c , so as to also be adjacent the plate  28  ( FIGS. 6 and 7   a ). Finally, the key  30  defines a plurality of plate engaging holes that function to fixedly connect the key  30 , and therefore the cradle  26  to the plate  28  ( FIG. 7 ). 
     As shown in  FIGS. 8 and 8   a , the EMS/receiver mounting plate  28  presents a planar rectangular structure for interconnecting the cradle  26  and EMS engaging structure  32  to the EMS rail  12 . As such, the preferred mounting plate  28  defines a plurality of engaging through-holes for adjustable interconnection with the EMS structure  32 , key  30 , and rail  12 . The preferred mounting plate  28  further defines a mounting plate projection  28   a  parallel to the long sides of the rectangle, and extending from a short side near one corner to the mid-point of the adjacent long side ( FIG. 8 ). The mounting plate projection  28   a  functions as a stop for the cradle  26 , so that the key  30  and stop  28   a  are cooperatively configured to hold the cradle  26  in a vertically fixed position as shown in  FIG. 8   b.    
     The structural components of the assembly  10 , including the pin  20 , receiver  18 , and VLS engaging structure  24 , are preferably formed of high-grade steel or another material comparable in compression, tensile and shear strength. In an alternative embodiment, however, the locator pin  20  and receiver  18  further present magnetically attractive elements, so that a holding force is produced when within close proximity of each other. In addition to or in lieu of the clamping device  22 , the pin  20  and receiver  18  in this configuration provide an interlocking mechanism for holding the rails  12 ,  14  in a fixed condition. More preferably, and as shown in  FIG. 4   c , the pin  20  may comprise a highly magnetically permeable core  34  and a wire coil  36  wound around the core  34 . The coil  36  is coupled to a controlled source (not shown) of electric potential so that an electric current flow can be produced therein and a resultant magnetic field generated. Thus, as is appreciated in the art, the pin  20  in this configuration presents a non-permanent magnet that is controllable by an operator. For example, once the pin  20  is received by the receiver  18 , the core  34  can be magnetized to lock the rails  12 ,  14  in place, and then de-magnetized to allow the VLS rail  14  to descend. 
     More preferably, and as best shown in  FIGS. 1 through 3   d , the assembly  10  further includes a clamping device (or lock)  22  fixedly attached to the stationary EMS rail  12  at or near each interface  16 . The assembly  10  includes either a left or right side actuating device  22  (compare,  FIGS. 1  and l a  (left), and  FIGS. 2 and 2   a  (right)) depending upon whether an entry or exit interface is engaged. As previously mentioned, the clamping device  22  is configured to produce the holding force so that it equally and oppositely engages the main and VLS rails  12 ,  14 . 
     In this configuration, the clamping device  22  includes a pivotal swing arm  38  that presents a distal arm end. The assembly  10  is configured so that the arm  38  contacts and transmits the force to the pin  20  when in the engaging position shown in  FIGS. 1 through 2   a . Once the carrier is properly positioned on the VLS rail  14 , the swing arm  38  is able to rotate downward a minimum angle (e.g., 30 degrees), which allows it to clear the rail  14  as the VLS descends into the work cell. More preferably, the arm  38  is configured to swing at least 60 and not more than 120 degrees (see,  FIG. 3  showing the rotated arm in hidden-line). To that end, the clamping device  22  further functions to also produce a return force that causes the arm to disengage the pin  20  and swing downward. 
     The arm  38  presents an integral structure that features an arched elbow  38   a  and a raised portion  38   b  for added structural capacity (see  FIGS. 9 and 9   a ). At the distal end of the arm  38 , a lift pad engaging section  38   c  is presented for connecting the arm  38  to a lift pad  40  ( FIGS. 10 and 10   a ). The pad engaging section  38   c  defines a flat engaging surface and a plurality of engaging holes for aligning with a plurality of engaging holes defined by the lift pad  40 . 
     The preferred arm  38  is pivotably coupled to a driven mechanism (not shown) that is fluidly coupled to a pneumatic power source (also not shown). As such, the clamping device  22  further includes an accumulator tank  42  that is fluidly coupled to the source, and configured to equilibrate, so that a constant air pressure (e.g., 80 psi) is maintained. Alternatively, however, the clamping device  22  may be driven by conventional electro, electromechanical, or hydraulic means. Finally, the preferred clamping device  22  also includes a toggle-lock mechanism (also not shown), so that once the arm  38  swings past an activation point towards the engaging position, the mechanism locks the arm  38  in place to guard against a sudden loss of air pressure. The return force, in this configuration, causes the toggle-lock to reset. 
     As previously mentioned and shown in  FIGS. 1   a  and  2 , the clamping device  22  is fixedly connected to the EMS main rail  12  by an EMS engaging structure  32 . As shown in  FIGS. 11 through 11   e , the preferred structure  32  presents a multi-section bracket. More particularly, the bracket  32  comprises planar EMS engaging, receiver engaging, and device engaging sections  32   a - c , wherein the receiver engaging section  34   b  is orthogonally oriented relative to the other two sections  32   a,c . The sections  32   a - c  define a series of fastener receiving holes for alignment with the aforementioned device  22 , receiver  18 , and main rail  12 , and for receiving a plurality fasteners. For example, the EMS engaging section  32   a  defines a plurality of four holes, the receiver section  32   b  defines two upper region holes for connecting to the cradle  26 , and the device engaging section  32   c  defines a plurality of six holes, wherein the middle two are dowel receptacles  44  (typ.). For added structural rigidity, the preferred bracket  32  further includes a series of longitudinal flare sections  32   d  perpendicularly buttressing the EMS, receiver, and device engaging sections  32   a - c.    
     To effect the autonomous function of the assembly  10 , the EMS or VLS are preferably communicatively coupled to the clamping device  22 . More particularly, the EMS or VLS is configured to notify the clamping device  22  when the VLS rail  14  is in the operable position, and as such further includes necessary sensory and communication technology. In this configuration, the preferred clamping device  22  is programmably configured to produce the force only upon notification that the VLS rail  14  is in the operable position. Further, the clamping device  22  preferably includes a sensor (not shown) operable or is otherwise configured to determine when the swing arm  38  is in the engaging position. To avoid damaging the clamping device  22  or VLS rail  14 , the clamping device  22  is configured to notify the VLS when the swing arm  28  is or is not in the engaging position, and the VLS is configured to translate to the operable position only when the arm  28  is not in the engaging position. Finally, it is further desirous for the carrier to be communicatively coupled to the clamping device  22 , so as to inform the clamping device  22  of its departure from the station. In this respect, the clamping device  22  is preferably configured to produce the return force and disengage the pin  20 , only when notified of the departure of the carrier. The VLS or EMS, clamping device  22 , and carrier may communicate through conventional wire or wireless technology, and be interfaced by a programmable controller (also not shown). 
     Further and more detailed structural disclosure is provided in the various figures (see generally,  FIGS. 1 through 11   a ) with the understanding that the illustrated embodiment is exemplary in nature, non-exhaustive, and secondary relative to the description of the present invention provided herein. 
     The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments and modes of operation, as set forth herein, could be readily made by those skilled in the art without departing from the spirit of the present invention. The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus, assembly, or method not materially departing from but outside the literal scope of the invention as set forth in the following claims.