Abstract:
An elastic rail fastening device for securing a rail to a concrete tie having a spike secured therein. A top pressing spring engages the top surface of the rail flange for holding the rail against the tie. One end of the spring is supported beneath a shoulder on the metal spike. A spring receiver is fitted to the tie, and the other end of the top spring bears thereagainst. A side spring is inserted between the side of the rail flange and the spring receiver to receive transverse pressure working on the rail.

Description:
FIELD OF THE INVENTION 
     This invention relates to a device for fastening a rail to a concrete tie or the like. 
     BACKGROUND OF THE INVENTION 
     In fastening a rail to a concrete tie or the like according to a conventional method, the rail is placed on the tie, with a pad laid between the rail base and the tie. Both edges of the rail base are held by plate springs that are fastened from above to the tie with bolts and nuts. Where many trains run at high speeds, therefore, vibrating rails can loosen the bolts, thereby floating from the tie and causing derailment. Consequently, this type of fastening device has required substantial inspection and maintenance. 
     Many of the conventional bolt-nut-less fastening devices receive the transverse force, which is exerted by the rail pressed sideward by the wheel, directly with steel spikes preset in the concrete tie. When the transverse pressure becomes excessive, it can break the concrete tie due to the pressure being transmitted through the steel spikes. 
     To eliminate the aforementioned shortcomings in the conventional fastening devices, this invention interposes a side spring between the rail and the concrete tie. This side spring elastically receives the transverse pressure and thereby keeps the concrete tie free from the excessive force. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partly cross-sectional plan view showing an embodiment of the elastic rail fastening device according to this invention. 
     FIG. 2 is a cross-sectional elevation viewed along the lie A--A of FIG. 1. 
     FIG. 3 is a plan view of a pad. 
     FIG. 4 shows the right side of the pad. 
     FIG. 5 is a side elevation of a steel spike. 
     FIG. 6 shows the right side of the spike. 
     FIG. 7 is a plan view of a top pressing spring. 
     FIG. 8 is a side elevational view of the top spring. 
     FIG. 9 is a plan view of a side spring. 
     FIG. 10 is a side elevational view of the side spring. 
     FIG. 11 is a plan view of a spring receiver. 
     FIG. 12 is a side elevational view of the spring receiver. 
     FIG. 13 shows the right end of the spring receiver. 
     FIG. 14 schematically illustrates how the device of this invention is fitted by use of an installation tool. 
    
    
     DETAILED DESCRIPTION 
     As shown in FIGS. 1 and 2, a rail fastening device according to this invention includes a top pressing spring 5 which is supported at one end by being held under the sidewardly projecting chin 2a formed at the top of a steel spike 2, which spike is fixedly buried in a concrete tie 1. The other end of spring 5 is supported by the upper step 3a of a spring receiver 3. The lower side of the upturned portion of the spring 5 holds the flange top 4a of a rail 4. The spring receiver 3 is longitudinally wedge-shaped, with the back thereof adapted to contact the raised edge 1a of the concrete tie 1. The fastening device also comprises a side spring 6 that is inserted between the lower step 3b of the spring receiver 3 and the flange side 4b of the rail 4. 
     To be more precise, the rail 4 is transversely laid on the scooped or recessed portion of the concrete tie 1, with a pad 7 of insulating material interposed therebetween. As seen in the plan view of FIG. 1, the raised edges 1a at both ends of the recessed portion of the concrete tie 1 extend aslant at a slight angle relative to the longitudinal direction of the rail, but parallel to each other. The pad 7 is made of an elastic, electrically insulating substance. As shown in FIGS. 3 and 4, the pad 7 has opposed notches 7a to avoid interference by the steel spikes 2. At the same time, the steel spikes 2 as positioned in the notches 7a prevent the movement of the pad 7. 
     The steel spike 2 (which may be made of other metals than steel) is preset in the recessed portion of the concrete tie 1. As shown in FIGS. 5 and 6, the steel spike 2 has an enlarged lower portion 2b to prevent slip-out at its lower end when embedded in the tie, a flange 2c welded midway, and a top projection 2a facing away from the rail. The portion below the middle flange 2c is buried in the concrete tie 1. Coated with synthetic resin 8 etc., this buried portion is electrically insulated from the concrete tie 1. 
     The top pressing spring 5 depresses the flange top 4a of the rail 4. As shown in FIGS. 7 and 8, the top pressing spring 5 comprises a sheet of elastic material, such as spring steel, which is bent into a substantially elliptical shape, thus being bent through approximately 270° as illustrated. In the middle of one free end thereof, which constitutes the bottom when bent, there is formed a rectangular opening 5c to pass therethrough the head of the steel spike 2. An opening 5d (FIGS. 7 and 8) to catch the hook 10 of an installation tool 9 (FIG. 14) is provided in the side of the spring opposite to the rail. The other free end 5b, close to which the opening 5d is perforated, is projected below the horizontal extension of the opposite free end 5a. The top pressing spring need not always be shaped as described above, but in any way so far as it can depress the rail flange top 4a, with one end thereof supported by the steel spike. 
     The side spring 6 is placed between the flange side 4b of the rail 4 and the lower step 3b of the spring receiver 3. As shown in FIGS. 9 and 10, the side spring 6 is a square bar of elastic material shaped like a spectacle frame. That is, spring 6 is formed from an elongated straight bar, with the ends being bent inwardly to form a pair of adjacent partial loops. The straight portion 6a thereof rests on the spring receiver 3. Desirably, the internal width b 1  between the two curved ends or loops of the side spring 6 is equal to, or slightly greater than, the width b 2  of the steel spike 2. The two free ends 6b are spaced at the same distance H from the straight portion 6a so as to effectively perform the function of a spring. 
     The spring receiver 3 of electrically insulating material has two steps 3a and 3b on its rail side, as shown in FIGS. 11 to 13. A replaceable, stepped angle 3c is fastened with screws to the surface of the receiver. The spring receiver 3 is longitudinally wedge-shaped. The back 3d and the bottom 3e of the receiver 3 are so shaped as to fit the edge of the recessed portion of the concrete tie 1. 
     OPERATION 
     To fasten a rail 4 with the device of this invention, the pad 7 is placed so that the notches 7a contain the steel spikes 2 as preset in the recessed portion of the concrete tie. The rail 4 is then placed in position on the pad. 
     Next, the side spring 6 is placed so that the curved ends of loops thereof hold the spike therebetween with the fronts of these loops contacting the flange side 4b l of the rail 4. The head of the steel spike 2 is then passed through the rectangular opening 5c in the bottom of the top pressing spring 5 so that the one free end 5a thereof is supported under the projecting chin or shoulder 2a of the steel spike. The hook 10 of the installation tool 9 is inserted in the opening 5d in the other free end of spring 5. As shown in FIG. 14, a rail grip or channel 11 at the remote end of the tool 9 is placed on the rail 4. The tool lever 12 is then urged upwardly (counterclockwise in FIG. 14) so that hook 10 exerts a lifting force on the spring end 5b, and the spring receiver 3 is slid along the edge 1a of the tie 1, with the tapered end thereof at the head. The side spring 6 is placed on the lower step 3 b of the receiver 3. By lowering the lever 12 of tool 9, the free end 5b of the top pressing spring 5 is placed on the upper step 3a of the receiver 3 (FIG. 2). The tool 9 is then detached. This work is done on both sides of the rail 4. The rail flange tops 4a are thus depressed from both sides by the bottom of the upturned top pressing springs 5, and the flange sides 4b held between the side springs 6, thus fastening the rail 4 in position. 
     As evident from the above description, the fastening device of this invention depresses the rail flange top with the top pressing springs and holds the rail flange sides between the side springs. This permits securing the rail to the tie. Further, it prevents the breaking of the concrete tie, with the side springs 6 springs 6 elastically receiving the transverse pressure exerted by the running wheels along the rail. 
     Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.