DETAILED DESCRIPTION OF INVENTION

[0019] FIG. 1 illustrates a rail fastening system constructed according to the present invention and denoted generally by the reference numeral 10. System 10 includes a cast shoulder 12, an elastic rail spring clip 14, and an insulator 16. When applied to a railroad tie 18, which is preferably made of concrete or similar material, system 10 secures a railroad rail 20 to the tie 18. Preferably, two of the rail fastening systems 10 are used for each tie 18 on each rail 20, with one fastening system on the field side of each rail and another fastening system on the gauge side of each rail. The ties 18 are spaced apart and extend transversely to the rails 20 in the usual manner.

[0020] With reference to FIG. 2, the cast shoulder 12 of the present invention includes an anchoring portion 22 and a receiving portion 24. Anchoring portion 22 preferably includes two vertically extending legs 26 having flared lower ends 28 for attachment with concrete railroad tie 18. Preferably, the legs 26 are embedded in the tie 18 when the tie is cast. Receiving portion 24 includes a bottom surface 30 and two opposing sides 32. Bottom surface 30 is generally horizontal and is connected with the anchoring portion 14 and with the opposing sides 32. Preferably, bottom surface 30 also includes a ramped guide piece 36 for receiving elastic rail spring clip 14.

[0021] Opposing sides 32 each include a base 38 mounted on top of the bottom surface 30 and a more narrow wall 40 extending upwardly from the base 38. Preferably, because the width of the base 38 is greater than the width of the wall 40, the wall 40 extends from the outer edge of the base 38, relative to center of the bottom surface 30, such that the top of each base 38 provides a horizontal ledge surface 41 for accepting the elastic rail spring clip 14. Projecting inwardly toward the center of the shoulder 12 from the top of each of the opposing sides 32 is a flange piece 34. Preferably, each flange piece 34 includes a generally horizontal top surface 42 and an inwardly facing surface 44. The underside portion of each flange 34 has an inclined portion 46 which slopes downwardly as it extends toward the rail and connects with a generally horizontal portion 47 which closely overlies the elastic rail spring clip base when the clip is installed.

[0022] Flange piece 34 is arranged in a special configuration. On the top portion of each flange 34, a side edge 34a of the flange angles inwardly toward an axis centered between the opposing sides 32. The edges 34a converge as they extend toward the rail 20 such that the distance between the edges of the two flange pieces 34 decreases from the back of the receiving portion 24 to the front relative to the location of the rail 20. The convergence of the edges is such that the distance between the two edges 34a progressively decreases. The minimum distance between edges 34a is at a throat 48 which has a width less than the undeflected width of the arms of the clip 14.

[0023] Adjacent to the throat 48, each flange piece 34 is provided with a notch 50 which is recessed into edge 34a. Each notch 50 is bounded by two substantially vertical surfaces perpendicular to one another. Preferably, the notch 50 defines a square cut-out having a first surface 49, generally perpendicular to the vertical wall 32, which functions as a catch to impede the backward migration of the elastic spring clip 14 once the tips of its arms have passed beyond the throat 48. Additionally, the notch 50 includes a second surface 51, generally parallel to wall 32, which is of a sufficient length to allow the spring clip arms 54 to rest within the notch 50 without substantially extending beyond the receiving portion 24. As would be readily understood, structures having rounded or angled edges between the surfaces of the notch 50 are considered within the scope of the present invention, as are other configurations and arrangements of the edges 34a.

[0024] Preferably, the bottom surface 30, opposing sides 32 and flange pieces 34 are cast as a single piece. As is understood by those skilled in the art, the implementation of the bottom surface 30, opposing sides 32, and/or flange pieces 34 as separate components connected to one another is within the scope of the present invention.

[0025] With continued reference to FIG. 2, elastic rail spring clip 14 preferably includes a substantially horizontal base piece 52, two spaced apart arms 54 extending from the base 52 and two substantially horizontal tips 56 at the free ends of the arms 54. The tips are curved back generally toward the base 52. Preferably, spring clip arms 54 are compressible toward one another from a noncompressed or normal width to a compressed width by the application of a sufficient compression force.

[0026] With reference to FIGS. 3, 4, 5 and 6, the present invention allows pre-assembly of the elastic rail spring clip 14 to the cast shoulder 12 prior to the onsite implementation of the rail fastening system. The elastic rail spring clip 14 is applied into the back of the receiving portion 24 of cast shoulder 12 (the side opposite the rail 20) such that the base 52 passes between the vertical walls 40, and above the horizontal surfaces 41. As illustrated in FIG. 5, the bottom of base portion 52 of the elastic rail spring clip 14 contacts the top of the horizontal surface 41 and guide piece 36 as the spring clip progresses forwardly. Additionally, base portion 52 contacts and moves along surface 46. Inner surface 44, base 38 and guide piece 36 serve to guide and secure the elastic spring clip 14 as it passes into the cast shoulder 12.

[0027] After entering the back of the receiving portion, the elastic rail spring clip 14 continues to move into the cast shoulder 12 to a point where the substantially vertical leading ends 54a (see FIGS. 5 and 6) of the decompressed spring clip arms 54 contact the edges 34a, whereafter additional movement of the clip causes arms 54 to deflect toward one another. The spring clip arms 54 are gradually compressed as they move along the converging edges 34a toward the throat 48. After the leading ends of arms 54 pass the throat, the compressive force is removed and the arms 54 then spring outwardly in the notches 50 against surfaces 51. It should be understood that alternative methods of compressing the spring clip arms 54 are within the scope of the present invention.

[0028] As best illustrated in FIGS. 3 and 5, upon moving past throat 48, the spring clip arms 54 decompress, causing the arms to enter and rest in notches 50. Surface 49 provides a stop that engages the arms and prevents any backward migration of the decompressed spring clip 14. As illustrated in FIG. 3, the length of the second surface 51 allows the spring clip 14 to rest decompressed without extending substantially beyond the forward edge of the receiving portion 24. At this time, the system 10 has reached the preinstallation position where the clip 14 is partially assembled to the cast shoulder 12. As illustrated in FIG. 5, the shoulder 12 is imbedded into the concrete tie 18 and taken to the construction site. The cast shoulder 12 may be imbedded into the concrete tie 18 either prior to or after being coupled with the elastic spring clip 14.

[0029] As illustrated in FIGS. 4 and 6, at the construction site, rail insulator 16 is placed on the rail flange 20. Elastic spring clip 14 is then driven onto the insulator and rail flange such that the tip portions 56 of the arms contact and exert a rail hold down, force on the insulator 16 and rail. Additionally, as the spring clip 14 moves forward, the base portion 52 of the spring clip 14 enters the space beneath surface 47 and is closely received therein to assure that the arms 54 exert a strong force downwardly to secure the rail 20 in place. Thus, the only additional assembly required at the construction site is the placement of the insulator 16 and the provision of a driving force to the elastic rail spring clip 14 to fully assemble it.

[0030] With reference to FIGS. 3 and 4, the rail fastening system 10 also facilitates the disengagement of the rail hold down force from the elastic spring clip 14 without decoupling the spring clip 14 from the cast shoulder 12. To disengage the spring clip force, a backward migration force is applied to the spring clip 14 such that it the elastic spring, clip arms 54 at the most only minimally contact the insulator 16 and the rail hold down force is removed. Preferably, the backward migration force is sufficient to cause the spring clip anus 54 to reside within the notches 50 such that first surfaces 49 prevent any further backward migration. The second surfaces 51 allow the spring clip arms 54 to reside in the notches 50 without extending unduly beyond the edge of the bottom surface 30. To reapply the hold-down force, a driving force is applied to the back of the spring clip to push it forward such that the tips 56 of the spring clip arms 54 again contact the insulator and secure the rail 20.

[0031] The present invention allows for the partial pre-installation coupling of the elastic rail spring clip and the cast shoulder. Accordingly, some of the labor intensive actions can be accomplished prior to shipping the rail fastening system and concrete ties to the rail site thereby reducing the more costly labor required in the field to secure a rail to the tie. Further, the clips 14 are matched one to one with the shoulders 12 by being preassembled to them. Thus, clips are not subject to being misplaced as can occur when they are shipped to the site separately. Additionally, the present invention allows a previously mounted rail to be serviced/replaced without requiring a complete decoupling of the rail fastening system, thereby reducing the labor and time required to carry out such work.

[0032] From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.

[0033] It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

[0034] Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.