Abstract:
A two-way assembly consisting of a chassis-frame ( 11 ) formed by two branches ( 17 ) and ( 18 ) articulated pivoting about two end pins ( 21 ) and ( 22 ) each bearing two inclined guide rollers ( 14 ) along a rail ( 8 ). The chassis-frame ( 11 ) is longitudinally movable relative to the road axle ( 2 ) for reversing an automatically guided travel direction by the effect of a reversing actuator ( 15 ). The chassis-frame ( 11 ) can be lifted after the rollers ( 14 ) have disengaged from the guide rail ( 8 ) by a lifting mechanism acting on the chassis-frame arms. The axle ( 12 ) is automatically guided by a subassembly guided ( 9 ) by the chassis-frame ( 11 ). The guided subassembly ( 9 ) capable of being displaced transversely at the rear about a pivot point located in the proximity of the front rollers. The invention is particularly advantageous to manufacturers of rail-mounted road vehicles.

Description:
This invention concerns a bidirectional guide rail assembly for the axle of a road vehicle. 
     BACKGROUND OF THE INVENTION 
     Numerous rail guide devices for vehicles already exist. 
     Specifically, the inventions of the Société LOHR INDUSTRIE relate to a guide arm with two angled guide wheels which move along a guide rail. 
     This arm provides directional reference for an automatic steering mechanism. 
     The guide arm located at the front of the axle can be duplicated by using an arm at the rear of the axle. 
     For example, if the wheels on the axle lose traction or if strong cross winds or some other factor cause the vehicle to drift, it is desirable to eliminate excess pressure on the guide assembly by allowing the rear arm to slightly shift in a lateral direction over a specific area. 
     Another invention of the Société LOHR INDUSTRIE addressing this issue, filed in France as No. 97 01709, concerns a directional assembly with a limited lateral offset. 
     This bidirectional assembly consists of two independent double guide arms, one in the front and one in the rear. Each arm has an angled guide wheel engaged on a guide rail and moving along the rail, with the rear arm having the capacity for clearance. 
     The capacity for clearance is possible because of flexible transverse deformations in the connection between the arms and the chassis. 
     The front and rear guide means are not interconnected by a rigid mechanical assembly; therefore each arm can be raised individually, requiring complex assembly and controls. 
     SUMMARY OF THE INVENTION 
     One of the first goals of the invention is to provide a rigid connection between the front and rear guide wheels, thereby eliminating the formation of any angle between the arms and the guide rail, which is a configuration that can easily lead to derailment. 
     Another primary goal of the invention is to propose a simple and reliable method for modifying the configuration and allowing the vehicle to remain in guided mode when the direction of operation is reversed. 
     A secondary goal of the invention is to provide a bidirectional self-guiding assembly allowing easy transition between automatic guided mode along a rail to manual mode, in which the driver steers the vehicle. 
     A third goal of the invention is to allow the guide wheels to be raised during operation by simply freeing the mechanism holding the guide wheels together, followed by raising the assembly by using the lifting arms. 
     A fourth goal is to ensure that the guide wheels are firmly engaged on the guide wheels and locked in position. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the invention will become apparent from the following description, furnished by way of a non-limitative example, with reference to the drawings, wherein: 
     FIGS. 1 and 2 are general perspective views showing the bidirectional assembly according to the invention in the raised or neutral position (manual mode) and in the guided motion position, respectively; 
     FIGS. 3 and 4 are front views showing the bidirectional assembly according to the invention first in raised position and then in lowered position, engaging the rail; 
     FIG. 5 is a perspective with the elements separated to show the various component parts of the guide assembly according to the invention; 
     FIG. 6 is a detailed perspective view from the rear showing the extremity actuated by the reverse cylinder; 
     FIGS. 7 through 9 are schematic view of the guide assembly seen from above showing the positions of the separating elements in the three basic configurations without lateral movement, i.e., displacement in a first direction, raised position, and displacement in a second direction. 
     FIGS. 10 and 11 are schematic views showing two positions of lateral movement in opposite directions; 
     FIG. 12 is a perspective view of the assembly showing a variation with a longitudinal contact plate. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Bidirectional guide assembly  1  according to the invention is joined to a vehicle axle  2  having wheels  3  and  4  by means of an articulation  5  shown schematically by central connecting block  6  between vehicle axle  2  and a central axle block  7 . This articulation, which may be a ball-socket articulation, only transmits directional movement if the vehicle axle is a directional axle. 
     This bidirectional assembly is designed to guide vehicle axle  2  or to activate the directional wheels and guide them along guide rail  8  while providing the vehicle axle with lateral clearance, known as lateral offset, whatever the direction of movement. 
     In terms of function, this assembly can be divided into two essential sub-assemblies, a guiding sub-assembly  9  and a guided sub-assembly  10 . The first sub-assembly  9  is longitudinally displaceable in relation to axle  2 . 
     A dual interface connection connects each extremity of the chassis-frame  11  to guided sub-assembly  10  so that they are longitudinally displaceable in relation to the vehicle. 
     Guiding sub-assembly  9  is composed of a chassis-frame  11  which is self-supporting when positioned for movement along guide rail  8  and supported by vehicle axle  2  when in the raised position, that is, when configured to be guided manually by the driver of the vehicle. 
     Chassis-frame  11  comprises at each extremity a front pair  12  and a rear pair  13  of guide wheels such as wheels  14  angled in a downward-pointing V engaged on guide rail  8 , supporting the chassis-frame and moving it along said guide rail. 
     The dual interface connects each extremity of chassis-frame  11  to each extremity of guided assembly  10  by means of a composite articulation with a movable portion allowing each one, by means of longitudinally displacing the chassis-frame  11  relative to the vehicle and relative to the vehicle axle  2 , to alternate between the pivoting-axle state, or the angular transverse clearance state for automatic guidance, passing through the non-functioning state to the automatic guided state corresponding to the central position. 
     As indicated, guiding sub-assembly  9  is longitudinally and translationally displaceable in relation to axle  2  and essentially in the vehicle axle due to the action of inversion cylinder  15 , alternating between one extreme position of longitudinal operation relative to the rail and the opposite extreme position of longitudinal operation in the other direction. This reversal of end positions corresponds to the reversal in the vehicle&#39;s direction of operation in guided mode using directional rod  16 . 
     The change takes place by passing into a neutral central position, in which chassis-frame  11  can be raised and in which the guide wheels are not engaged on guide rail  8 . The bidirectional assembly becomes inactive and axle  2  is then guided manually by the driver across the direction of the vehicle activating the appropriate control connected to central axle block  7 , or directly to axle  2  or to the directional wheels, in order to change direction. 
     Following these general considerations, the different parts and elements comprising the bidirectional assembly of the invention will be examined in detail. 
     The chassis-frame  11  is formed of two longitudinal halves or branches  17  and  18  pivotably attached at each extremity to a longitudinal axle parallel to the longitudinal axle of the vehicle. 
     It is possible, as in the variation shown in the drawings, to have two straight-bodied, tubular branches  17  and  18  with inwardly curved extremities connecting at the tips at hinges  19  and  20 , which over lap to form a continuous cylindrical housing occupied by a portion of the end pivot axle  21 ,  22 , constituting the pivot assembly that joins the hinges to each other. Because of the right-left symmetry, end pivot axles  21  and  22  are aligned. 
     The upper portions of hinged elements  19  and  20  on pivoting branches  17  and  18  of frame  11  are each followed by support plates  23  and  24 , which are complex in form and fulfill several functions. 
     Said support plates  23  and  24  have a lower vertical portion which serves as an individual guide wheel support  25 ,  26 , and  27 ,  28  with a guide wheel such as wheel  14  attached to each one by means of a moving connection providing the necessary operational play. 
     The two opposing guide wheel supports are inclined at the same angle as the wheels and are attached precisely with some degree of elastic deformation. 
     Guide wheel supports  25  through  28  extend upward and curve inward horizontally, giving rise to half-plates  29  through  32  with hooked ends designed to move together laterally to form a plate support  23  or  24  for guiding and supporting movable separating elements  33  and  34  when the frame is raised, as well as to allow lateral clearance for these elements. Each movable spacing element  33  and  34  serves as a spacer and also assumes other functions such as that of a pivot axle between chassis-frame  11  and guided sub-assembly  10  for the movable spacing element located at the front, that of clearance block for the movable separation piece located at the rear, or that of a pivot block for branches  17  and  18  of frame  11 . 
     Each of the interface connections is an articulation incorporating an end piece  33  or  34  of guided sub-assembly  9  and a support longitudinally movable relative to the vehicle which constitutes the upper portion of each extremity of guiding sub-assembly  9 . 
     Support plates  23  and  24  define a support with dual levels which can be inclined when the branches of chassis-frame  11  pivot. They each consist of the side-by-side arrangement of two half-plates  29 , 30  and  31 ,  32  with hooked ends moving next to each other and tilting together or apart from each other as the branches of the chassis-frame ( 11 ) pivot up or down to allow displacement of the guide wheels in relation to one another. 
     The two half-plates  29 ,  30  and  31 ,  32  define a central opening  35  which is pear-shaped with a narrow median portion  36  separating a large clearance opening  37  directed toward the central portion of chassis-frame  11  and a small guide opening  38  each directed toward one extremity of chassis-frame  11 . Support plates  23  or  24  are each traversed by one of the movable separating elements  33  or  34  as they are displaced in the longitudinal axle of the directional assembly along central opening  35  to narrowed portion  36 . 
     Large opening  37  has converging edges  39  and  40 . These edges converge toward a narrowed median zone  41  corresponding to narrowed portion  36  near the entry of small opening  38  (FIG.  6 ). 
     Each central opening  35  is displaced while guided by a movable separating piece; its edges support corresponding movable separating piece  33  or  34  at the level of its upper portion. 
     Each extremity of branches  17  and  18  of chassis-frame  11  forms a single mono-block element incorporating three functions: guide wheel support, pivoting articulation between branches  17  and  18 , and movable sliding/guiding support for each end piece of guided sub-assembly  10 . 
     Preferably, separating elements  33  or  34  are shaped like coil-axles with the cylindrical central portion  42  forming the axle and with two end flanges  43  and  44 . 
     Support plates  23  and  24  along with their related functional elements are located inside chassis-frame  11 . 
     The invention also concerns an embodiment in which the functional groups of support plates  23  and  24  and the associated guide wheels  14  are arranged in the reverse configuration, that is, with support plates  23 ,  24  outside chassis-frame  11  and guide wheels  14  inside chassis-frame  11 . 
     Each separating element  33  and  34  can assume three characteristic positions: an automatically guided directional position within small opening  38 , a limited lateral clearance position within large opening  37 , and a neutral intermediate position at the entry to narrowed portion  36 , the latter being the configuration in which the frame is raised, that is, in the inoperative state when it is in the intermediate position between the two openings in narrowed portion  36 . 
     The width of small opening  38  when connecting the supporting half-plates must be smaller than the diameter of cylindrical axle  42  of separating elements  33  or  34  in order to lightly push wheels  14  together after clearing narrow portion  36 , that is, to impose a force impelling them toward each other when they are engaged on guide rail  8 . 
     Guided sub-assembly or central mechanism  10  is composed of a cross axle  45  pivotally connected to the vehicle axle  2  by central connecting block  6 . In manual mode, when chassis frame  11  is in the non-functioning, raised position, cross axle  45  may remain immobile and in turn, the directional wheels are steered by another control which takes over; optionally, rod  16  is no longer subjected to the pivoting movement of the automatic bidirectional assembly. 
     Cross axle  45  has a double cross shape with two transverse structures  46  and  47 , each having a pivoting arm  48  and  49  attached to it. 
     The unit formed by the two connecting pivoting arms  48  and  49  constitutes the articulated connection between guided sub-assembly  10  and displaceable guiding sub-assembly  9 . 
     Pivoting connecting arms  48  and  49  each consist of two branches  50 ,  51  and  52 ,  53  with angled ends, joined at the angled extremities located above cross-axle  45  by a transverse pivot axle  54  integral with the bodies of separation elements  33  or  34 . The opposite extremities of the branches of pivoting arms  48  and  49  are pivotably attached to the extremities of transverse structures  46  and  47  forming central cross axle  45 . 
     Separation elements  33  and  34  are formed by tubular axle  42  terminating in two end flanges  43  and  44  allowing them to rest on support plates  23  and  24 . It is obvious that end flanges  43  and  44  must be larger in diameter than the large opening  37  in support plates  23 , and  24 . 
     Said support plates  23  and  24  are duplicated at the lower portion by sliding plates  55  and  56 , which are flat and made as a single piece. Generally triangular in shape, each has a central opening  57  which is pear-shaped or similar to the opening in support plates  23  and  24 . Said sliding plates  55  and  56  are inseparable and the top of each one extends into a solid or tubular axle element, each of which forms one of the end axles  21  and  22 . 
     The support plates and the sliding plates are guided in displacement along separation elements  33  and  34  when chassis-frame  11  moves translationally. 
     The motion originates from the action of dual reverse cylinder  15  articulated between the subsurface of one longitudinal extremity of cross axle  45 , for example, the axle that receives directional rod  16  by means of pivoting articulation  58 , and one of the sliding plates  55  or  56  by means of pivot axle  59  attached between two elements. 
     The bidirectional assembly according to the invention is completed by a lifting mechanism  60 , which may consist, for example, of a pneumatic or hydraulic drive means  61  with an articulated rod which pivots two lifting arms  62  and  63  with hooked ends  64  and raises or lowers them. Lifting arms  62  and  63  are pivotably articulated to cross axle  45  on central axle block  7 . Their hooked ends  64  contact the branches  17  and  18  of chassis-frame  11 , causing them to pivot upward slightly during the first lifting phase as far as the block that abuts the halves of upper support pieces  23  and  24 , thus disengaging guide wheels  14  and finally raising the unit and releasing guide wheels  14  from guide rail  8 , as described in detail below. 
     The end hooks  64  of lifting mechanism  60  do not engage the branches of chassis frame  11 . They merely constitute a second lateral block which provides additional security by limiting lateral offset in axle  2  if traction is lost. 
     The bidirectional assembly also comprises a flexible transverse plate  65 , preferably spring-loaded, applying permanent flexible pressure and pressing down upon the guide wheels on the guide rail, and also a supplemental flexible force pushing guide wheels  14  together so they will grip rail  8 , thereby providing the security of elastic recall by pivoting downward. 
     In branch  18 , either near direction control rod  16  or formed within this branch, there is a downward deformation  66  forming a recess designed to eliminate any harmful interference between chassis frame  11  and the direction control rod. 
     FIG. 12 shows a variation of the lifting assembly in which the guide wheels are not released from the guide rail. The constant downward preconstraint takes the form of permanent localized contact on the upper portion of each separating element  33  or  34 . This flexible preconstraint consists of flexible pressure which, in the embodiment shown, arises from the extremities of a fixed longitudinal spring-loaded plate  67 . Each extremity  68  or  69  of the plate contacts upper flange  70  or  71 , respectively, of each separation element  33  or  34 . The upper plane formed by the two half plates  29 ,  30  and  31 ,  32  located side by side slides below these flanges when chassis frame  11  is longitudinally displaced at the moment the reverse cylinder reverses the direction of movement. 
     This variation is also distinguished by a different lifting mechanism. Referring to FIG. 12, note that the lifting mechanism uses the pivoting connecting arms  48  and  49  on guided sub-assembly  10 . The drive means is a separating cylinder  72  attached parallel to guide rail  8  between two branches similar to the two pivoting connecting arms. Separating cylinder  72  comprises a shaft  73  and a body  74 . The free end of shaft  73  is articulated to a housing  75  and body  74  to another housing  76  integral with the adjacent branch of pivoting arms  49  and  48 , respectively. The cylinder may have two shafts. In this case, the second shaft is attached to the corresponding housing. 
     During the lifting operation, this cylinder works by separating the two pivoting connecting branches which, when pushed, are forced into an upward pivoting motion and are lifted when they encounter the flexible downward push of longitudinal contact plate  67 . Because of the constant flexible contact on half-plates  29  through  32  arranged side by side exerted by the ends of longitudinal plate  67  through flanges  70  and  71 , the lifting motion does not necessarily cause the guide wheels to have previously separated, even if not locked together. 
     The invention also relates to a simplified variation (not shown) in which the chassis frame  11  is no longer formed of two pivoting branches  17  and  18 , but is formed of a rigid frame or perimeter. 
     As before, in this variation the guide wheels are vertically pressed against the guide rail by some type of flexible downward pressure originating from one or more sources to improve wheel guidance. It is obvious that in this embodiment, it is not possible to disengage the wheels during the lifting operation. Therefore, the wheels must be removed from the rail at the end of the guided zone. 
     Three modes of operation are distinguished: 
     manual mode in which frame  11  is raised; 
     operation in automatic guided mode in one direction with limited lateral movement; 
     operation in automatic guided mode in the other direction with limited lateral movement. 
     The transition from one automatic guided mode to the other occurs due to the action of reverse cylinder  15  when the vehicle is stopped. 
     In automatic guided mode, the front separation element, for example element  33 , is located inside small opening  38  in the support plate, for example support plate  23  located near the front, while rear separation element  34  occupies a central position in the large opening  37  of rear support plate  24  in order to allow a certain amount of angular lateral clearance for axle  2 . 
     The passage from one guided mode, subjected to the rail in one direction (FIG. 7) to the other guided mode in the other direction (FIG. 9) occurs by virtue of action on cylinder  15 . The cylinder acts on the opposing side plate  55  and either pushes or pulls frame  11  with its support plates  23  and  24  relative to axle  2  to reverse the positions of separating element  33  and  34  relative to the corresponding lights. 
     Separating element  33  or  34  occupying small opening  38  in support plate  23  or  24  is always the forward separating element in the direction of operation. It serves as the pivot center for automatic guiding. In this position, the presence of the front separating element prevents guide wheels  14  from leaving rail  8 , maintaining them close together by separating the adjacent half-plates. 
     FIGS. 10 and 11 show the lateral clearance of axle  2  allowing an angular deviation “a” relative to the direction transverse to the vehicle. 
     The transition to the manually guided mode (FIG. 8) occurs when reverse cylinder  15  places frame  11  in a median position, which corresponds to the two tubular portions  42  having exited the narrowed portion  41  of central opening  35 . The wheels are thus freed from pivoting in relation to each other. 
     Next is the lifting operation. As with the variation shown in the first drawings, the lifting operation takes place when a drive means  61  acts on the rod of lifting mechanism  60 . The pull on the extremities of lifting arms  62  and  63  makes them pivot upward and thus raises branches  17  and  18  of chassis frame  11  up to the level of the connection between the two half plates of each support plate  23  or  24  (FIGS.  3  and  4 ). 
     The chassis frame  11  raises up and guide wheels  14  lift and are freed from rail  8  at the same time as the pivots and the mechanically associated elements such as pivoting connection arms  48  and  49 , assuming an upper position in which the extremities of lifting arms  62  and  63  force branches  17  and  18  of frame  11  against flexible transverse plate  65 . The latter element provokes a flexible downward push, thus producing a locking and immobilizing effect against the hooked extremities of lifting arms  62  and  63 . 
     During this movement, pivoting connection arms  48  and  49  of guided sub-assembly  10  pivot upward, since the first extremities of the arms are driven into an ascending motion by separation elements  33  and  34 , which are themselves raised by chassis frame  11 . 
     In the variation in FIG. 12, lifting occurs through the use of a horizontal separation cylinder  72 . On command, this cylinder causes the pivoting connection arms of the guided sub-assembly pivots to separate and pivot, thus freeing the guide wheels from the guide rail. 
     To return to the automatically guide mode, the reverse operations are performed. 
     The guide wheels are repositioned in locked configuration on the rail, having either been previously separated or not, depending upon the embodiment. 
     However, in the simplified variation with the rigid chassis frame, which is not shown, it is necessary to engage the guide wheels by passage through a guide entry zone.