Railway wheel apparatus for a road vehicle
TECHNICAL FIELD 
     This invention relates to apparatus for mounting at the rear of a road vehicle so as to adapt the vehicle for operation on railway tracks whereby flanged wheels and an associated axle are lowered and raised relative to the vehicle frame. 
     BACKGROUND ART 
     Known devices for adapting a road vehicle for use on railway tracks ordinarily contemplate the provsion of flanged wheels pivotally mounted on the vehicle frame and arranged to swing through an arc so as to raise or lower the flanged wheels as desired. Such prior art structures project outwardly from the vehicle frame and thus require additional space and are not well adapted for sidewise movement relative to the vehicle frame so as to accommodate minor misalignment between the road vehicle wheels and the railway tracks. 
     DISCLOSURE OF THE INVENTION 
     According to this invention in one form, flanged wheels and their associated axle are raised and lowered vertically relative to the vehicle frame instead of being moved through an arc. In addition the apparatus includes toggle structures which are arranged to swing in planes which are disposed in general alignment with and parallel to the axle on which the flanged railway wheels are mounted so that sidewise movement of the flanged wheels relative to the vehicle frame and to the railroad tracks is readily accomplished thus avoiding tedious alignment of the vehicle road wheels with the railway tracks. More specifically a pair of flanged wheels mounted in spaced relation on an axle are interconnected with a road vehicle frame by means of a first pair of spaced apart toggle structures which are pivotally connected at one end thereof to the axle together with a second pair of spaced apart toggle structures which are pivotally connected at one end thereof respectively to the other ends of the first pair of toggle structures and in turn are pivotally connected at their other ends to the vehicle frame whereby extension of said toggle structures into substantial alignment with each other effects downward lowering of the axle and wheels and angular movement of the toggle structures relative to each other effects retraction of such structures whereby the axle and wheels are raised and fluid motors for extending and retracting the toggle structures relative to each other. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings, 
     FIG. 1 is a perspective view of a road vehicle to the rear end of which a railway wheel apparatus constructed according to this invention is mounted; 
     FIG. 2 is a view from the rear of apparatus formed according to this invention and which depicts the flanged wheels and their associated axle spaced to the left side of railway tracks; 
     FIG. 3 is a view similar to FIG. 2 but which shows the flanged wheels and axles spaced to the right side of the railway tracks; 
     FIG. 4 shows the flanged wheels properly aligned with and mounted on the railway tracks; 
     FIG. 5 depicts apparatus in its retracted position; 
     FIG. 6 shows the apparatus in its lowered or extended position; 
     FIG. 7 shows a locking pin provided according to a feature of the invention; and 
     FIG. 8 is an enlarged cross sectional view taken on the line designated 8--8 in FIG. 6. 
    
    
     BEST MODE OF CARRYING OUT THE INVENTION 
     In the drawings, the numeral 1 generally designates a truck on which railway wheel apparatus 2 formed according to this invention is mounted. 
     In FIGS. 2, 3, and 4, the numeral 3 designates a part of the frame of vehicle 1. A pair of support elements 4 and 5 are secured as by suitable bolts 6 to the frame 3. A base plate 7 is bolted or otherwise secured to the lower portions of support elements 4 and 5. 
     Flanged wheels 8 and 9 are mounted on axle 10 and are adapted for cooperation with railway tracks 11 and 12. Axle 10 is interconnected with the frame 3 and support elements 4 and 5 as well as base plate 7 by means of a first pair of toggle links 13 and 14 together with a second pair of toggle links 15 and 16. Toggle link 13 is pivotally connected at 17 to axle 10 while toggle link 14 is pivotally connected at 18 to axle 10. Toggle structure 13 is pivotally connected with toggle structure 15 at pivot 19 to form one toggle while toggle structure 14 is pivotally connected to toggle structure 16 at pivot 20 to form another toggle. Toggle structure 15 is pivotally connected with the base plate 7 and support element 4 by pivot 21 while toggle structure 16 is pivotally connected with support element 5 and base plate 7 at pivot 22. 
     As is apparent particularly in FIGS. 2 and 3, toggle structure 13 comprises a pair of spaced coincidental toggle links 13a and 13b while toggle structure 15 comprises a pair of spaced coincidental toggle links 15a and 15b. In like fashion, toggle structure 14 includes a pair of spaced coincidental toggle links 14a and 14b while toggle structure 16 includes a pair of spaced coincidental toggle links 16a and 16b. 
     When the flanged wheels and axle are in their retracted or upper positions, the parts occupy the positions represented in FIGS. 1 and 5. When the apparatus is extended into its lower position the parts occupy the positions shown in FIGS. 4 and 6. 
     For the purpose of imparting operating movement to toggle structures 13 and 15, operating means in the form of a fluid motor generally designated at 25 is provided and includes a cylinder 25a and a piston not shown but having a piston rod 25b. The right hand end of piston rod 25b is pivotally connected at pivot 26 with a structure 27 secured by welding or otherwise to the axle 10 at approximately the mid point thereof. Cylinder 25a is partially between links 15a and 15b and between toggle links 13a and 13b and is pivotally connected thereto by pin 19 so that outward movement of piston rod 25b relative to cylinder 25a tends to swing toggle structure 15 in a clockwise direction about pivot 21 while such operating movement imparts swinging movement to toggle structure 13 in a counterclockwise direction about pivot 17 so that ultimately these structures 13 and 17 occupy the positions as shown in FIG. 4. 
     Operating movement is imparted to the fluid motor 25 from a source of fluid pressure not shown through a pair of flexible conduits 27 and 28. Flow through these conduits is controlled by conventional valve means generally designated at 29 and which includes a manually operated control lever 30. Thus in order to drive the piston rod 25b outwardly and toward the right as viewed in FIG. 2 relative to cylinder 25a, fluid pressure is supplied through conduit 27 to the left hand end of cylinder 25a and fluid is discharged from cylinder 25a through conduit 28 in conventional fashion due to appropriate operation of manual lever 30. If it is desired to retract piston rod 25 fluid is supplied to cylinder 25a through conduit 28 and is discharged from cylinder 25a through conduit 27 due to appropriate operation of manual lever 30. 
     In like fashion, a similar fluid motor 31 is associated with toggle structures 14 and 16 and includes a cylinder 31a and a piston not shown and an associated piston rod 31b. Piston rod 31b is pivotally connected at 32 to structure 27 and the cylinder 31a is pivotally connected at pivot 16a. Control of fluid motor 31 is by means of conduits 33 and 34 together with manually operable control lever 35. 
     With the railway wheel apparatus disposed in its uppermost position as represented by FIG. 5, the apparatus is lowered by supplying fluid pressure such as hydraulic liquid to the cylinders 25a and 31a through conduits 27 and 33 thereby to extend or straighten the toggle structures 13, 15 and 14, 16 so as to cause the parts to occupy the positions represented in FIG. 4 at which the flanged wheels 8 and 9 are in cooperative contact with the rails 11 and 12 respectively. 
     Since the toggle structure 13,15 and 14,16 operate in a plane parallel to an in general alignment with the axle 10, these structures do not protrude outwardly to any significant extent beyond the frame 3 of the vehicle 1 and parts associated therewith. Of course, this action of the cooperating parts imparts up and down vertical movement to the flanged wheels 8 and 9 and the associated axle 10 rather than causing movement of the wheels and axle through an arcuate path as is the practice with known structures. 
     According to another feature of this invention, it is not essential that the vehicle road wheels be precisely aligned with the railway tracks when the vehicle is positioned to allow the flanged wheels to move downwardly and into engagement with the railway tracks. This aspect of the invention is represented at FIGS. 2 and 3. In FIG. 2, the road vehicle wheels are not precisely aligned with the vehicle tracks 11 and 12 and lowering of the axle and flanged wheels 8 and 9 may be accompanied by sidewise movement of the axle and wheels simply by appropriate control of the manual levers 30 and 35. As shown for example in FIG. 2, the flanged wheels 8 and 9 are to the left of the railway tracks 11 and 12. In order to cause those wheels to move toward the right and into proper alignment with the railway tracks without moving the vehicle, it is simply necessary to supply fluid to cylinder 25a through conduit 27 and simultaneously to withdraw fluid from cylinder 25a through conduit 28. This action causes the piston and associated piston rod 25b to move toward the right relative to cylinder 25a and thus imparts a force to the axle 10 which is toward the right and which moves the axle 10 and wheels 8 and 9 toward the right. Simultaneously hydraulic fluid is supplied to cylinder 31a through conduit 34 and fluid is withdrawn from cylinder 31a through conduit 33 to allow the piston rod 31b to move inwardly and toward the right relative to cylinder 31a and such movement imparts a sidewise force to pivot 32 and to axle 10 through support 27 which cooperates with the force applied by piston rod 25b and in cooperative fashion to align the wheels 8 and 9 with the tracks 11 and 12 as shown in FIG. 4. 
     In like fashion, if the initial position of wheels 8 and 9 is to the right of tracks 11 and 12 as shown in FIG. 3, the manual operating levers 30 and 35 are appropriately manipulated so as to move the axle 10 and wheels 8 and 9 toward the left to occupy a proper position atop the tracks 11 and 12 as shown in FIG. 4. 
     For the purpose of mechanically securing the toggle structures such as 14 and 16 in their extended position as shown in FIG. 6, mechanical interlocking means is provided and includes a locking aperture 40 formed in at least one link comprising the toggle structure such as 16 which when disposed in the extended or lowered position as shown in FIG. 6, coincides with an aperture not shown formed in one of the links such as 14a forming a part of toggle structure 14. Into these coinciding apertures, a locking element 42, best shown in FIG. 7, is inserted so as to secure these parts against relative movement. The locking element, as shown in FIG. 7, includes a chain 42a for retaining the locking element when disposed in unlocked condition, the chain being secured to an associated toggle structure, and a flange 43 together with a transverse extension 44 and a locking portion 45. Thus with the locking portion 45 inserted into the coincidental apertures 40 and the associated aperture in 14a which is not shown the flange 43 limits the inward travel of locking portion 45. 
     In order to prevent inadvertent dislodgment of the locking pin 42 from the coincident apertures, a holding ledge 46 is secured to the link such as 16a, the leg 47 of device 46 being welded to the link 16a and the ledge portion 48 extending toward the aperture 40. Thus with the locking pin 45 properly inserted so that the flange 43 engages the link 16a, the transverse extension 44 of locking pin 42 is swung underneath the ledge portion 48 of the ledge 46 so as to prevent outward dislodgment of the locking pin 42. 
     When the mechanism is operated to its retracted or upper position, the locking aperture 41 formed in link 16a swings into coincidence with the locking aperture not shown but which is formed in link 14a. Thereafter a locking pin, such as 42 is inserted through the coincidental locking apertures to secure the parts in their elevated positions and the transverse extension 44 of locking pin 42 is swung underneath the holding ledge 48a of the holding device 46a which is secured to link 16a adjacent the locking aperture 41. 
     An abutment element 50 is fixedly mounted on a part of two of said toggle structures and engages a part of the other associated toggle structure for arresting relative movement thereof at the approximate limit of extended movement of the toggle structures. 
     INDUSTRIAL APPLICABILITY 
     Railway wheel apparatus for a road vehicle formed according to this invention is particulalry advantageous because it provides for lowering flanged wheels vertically rather than through an outwardly swinging arc and thus avoids interference with other objects and conserves space underneath the vehicle body. The invention also is especially adapted to provide for lateral shifting of the flanged wheels and the associated axle relative to the road vehicle whereby precise alignment of the road vehicle wheels with the railway tracks is not necessary, thereby greatly facilitating easy transition from roadway service to service on railway tracks.