RAILROAD TIE

Abstract

An improved railroad tie comprises a monolithic elongate tie body divided into a pair of end sections and a narrow mid section interconnecting the pair of end sections. Further, the top surface of each end section divided into a proximal and distal surface sections interconnected by a rail seat section whereon a rail is fixedly mounted. The proximal and distal surface sections slope downwards, in opposing directions, as they extend longitudinally from the rail seat section and connect the top surface of the mid section and the extreme lateral edge of the top surface of the end section respectively. The mid section is of uniform trapezoidal cross-section. The railroad tie further comprises a plurality of steel rebars cast within the tie body.

Description

BACKGROUND

Technical Field

This invention relates to railway engineering and more particularly to railroad ties.

Concrete railroad ties are reinforced or pre-stressed concrete beams generally configured to have a uniform and trapezoidal cross-section. Steel bars are typically embedded into a railroad tie for reinforcement purposes. The top surface at each end of the railroad tie is fitted with a rail attachment means (called fastening system). The base of the railroad tie is wider than its top surface so as to have the ties-ballast contact pressure less than the allowable amounts. Although these typical railroad ties are effective in carrying out their purpose, they are not optimally designed and hence not cost-effective. More particularly, although, the central section of the railroad tie is not subjected to the same amount of load as the end sections of the railroad tie, nonetheless, the former is “invested” with the same amount of raw material (concrete). This superfluous material on the central section not only makes the railroad tie expensive but also bulky and heavy. Furthermore, the amount of steel bars used in the conventional ties is not optimum.

Therefore, in the light of the above discussion, there is a need in the art for an improved railroad tie that has an optimal design, and is thereby cost-effective. Such a railroad tie should also possess all mechanical and structural characteristics required by the international standards.

SUMMARY

The present invention is an improved railroad tie which aims to address the above mentioned need: to have an optimal structural configuration and thereby, being cost-effective. The railroad tie is a longitudinal beam which comprises a monolithic elongate tie body divided a pair of end sections interconnected by a mid section. The top surface of each end section includes a rail seat section whereon a rail sits. The mid section is narrower and is of uniform trapezoidal cross-section. Compared to the typical concrete railroad ties discussed above, the railroad tie of the present invention consumes lesser amount of raw material, i.e., concrete and steel, owing to the narrow structural configuration of the mid section. Steel bars are cast within the railroad tie for pre-stressing. The improved railroad tie, while possessing all the mechanical and structural characteristics required by international standards, is lighter, less bulky, and essentially cost-effective compared to traditional concrete railroad ties. Also, less ballast is needed for the railroad tie since its structural configuration causes a more uniform stress distribution of the pressure on the ballast and thereby less stress concentration on and within the ballast layer.

The other objects and advantages of the embodiments herein will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of the perspective view of the railroad tie according to the present invention.

FIG. 2 is an illustration of the front view of the railroad tie according to the present invention.

FIG. 3 is an illustration of the plan view of the railroad tie according to the present invention.

FIG. 4 is an illustration of the perspective view of the end section of the railroad tie according to the present invention.

FIG. 5 is an illustration of the plan view of the end section of the railroad tie according to the present invention.

FIG. 6 is an illustration of the perspective view of the mid section of the railroad tie according to the present invention.

FIG. 7 is an illustration of the sectional side view of the mid section of the railroad tie according to the present invention.

FIG. 8 is an illustration of the front view of the railroad tie with dimensions in accordance with the present invention.

FIG. 9 is an illustration of the plan view of the railroad tie according to the present invention.

FIG. 10 is an illustration of the sectional side view of the mid section of the railroad tie according to the present invention.

FIG. 11 is an illustration of the side view of the railroad tie according to the present invention.

FIGURES

Reference Numerals

• 10 . . . Railroad tie
• 12 . . . Tie body
• 14 . . . End section
• 16 . . . Mid section
• 18 . . . Proximal surface section
• 20 . . . Distal surface section
• 22 . . . Rail seat section
• 24 . . . Lateral groove
• 26 . . . Lateral ridge
• 28 . . . Top surface of the mid section
• 30 . . . Rebar

DETAILED DESCRIPTION

In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

Referring to FIGS. 1 through 3, the present invention comprises a railroad tie 10, which serves as a base for railroad tracks. The railroad tie 10 transfers the load from the track onto the ballast, whereon the railroad tie 10 is placed. The railroad tie 10 is preferably made of pre-stressed reinforced concrete, which, compared to the commonplace reinforced concrete, offers better compressive strength, longer life expectancy, and easier maintenance.

Still referring to FIGS. 1 through 3, the railroad tie 10 comprises a monolithic elongate tie body 12 defined by an elongate top surface, an elongate substantially flat bottom surface, a pair of opposing elongate side surfaces connecting the longitudinal edges of the top and bottom surfaces, and a pair of opposing end surfaces connecting the lateral edges of top, bottom, and side surfaces. At any point along the length of the tie body, the width of the top surface is lesser than that of the bottom surface. More particularly, the tie body 12 is of a substantially trapezoidal cross-section at any point along the length thereof. This trapezoidal structural configuration of the tie body 12 helps the railroad tie 10 in uniformly distributing load from the track to the ballast. The bottom surface may be coarse or may be provided with gripping indentations in order for the tie body to have traction on the ballast, which helps resisting any movement of the railroad tie on the ballast.

The length of the tie body is divided into three sections, viz., a pair of end sections 14, and a mid section 16 interconnecting the pair of end sections. Referring to FIGS. 4 and 5, the top surface of each end section can be divided into three sections, viz., a proximal surface section 18, a distal surface section 20, and a rectangular rail seat section 22 interconnecting the proximal and distal surface sections 18 and 20. The rail seat section 22 receives a rail attachment means thereon. Each lateral edge of the rail seat section 22 terminates in a lateral groove 24 of uniform cross-section. A lateral ridge 26 of uniform cross-section extends from the lateral edge of each groove 24.

Still referring to FIGS. 4 and 5, the proximal surface section 18 interconnects the lateral edge of a ridge 26 and the lateral edge of the top surface of the mid section 16 wherein, the width of the lateral edge of the proximal surface section 18 extending from the ridge 26 is greater than that of the opposing lateral edge of the proximal surface section 18 connecting the top surface of the mid section 16. The proximal surface section 18 slopes downward as it extends from the ridge 26 towards the mid section 16. The distal surface section 20 interconnects the lateral edge of the other ridge 26 and the top edge of the of the corresponding end surface wherein, as in the earlier case, the width of the lateral edge of the distal surface section 20 extending from the ridge 26 is greater than that of the opposing lateral edge of the distal surface section 26 connecting the end surface. The distal surface section 20 also slopes downward as it extends from the ridge 26 towards the mid section 16. The slope of the initial portions of the proximal and distal sections 18 and 20 longitudinally proceeding from the ridges 26 is steeper compared to that of the latter portions of the proximal and distal surface sections 18 and 20 joining the mid section 16 and the end surface respectively.

Referring to FIGS. 6 and 7, the mid section 16 of the tie body 12 is narrow compared to the pair of end sections 14, i.e., the height and width of the mid section 16 is lesser than that of the pair of end sections 14. The mid section 16 of the tie body 12 is of uniform substantially trapezoidal cross-section. The width of the rail seat section 22 is greater than that of the top surface 28 of the mid section 16.

Referring to FIG. 7, the railroad tie 10 further comprises a plurality of elongate steel rebars 30 embedded longitudinally into the tie body 12. Preferably, two sets of rebars 30 are cast within the tie body 12. Each set includes three rebars 30 that are horizontally aligned. The sets are placed such that each rebar 30 of a set is vertically aligned with a rebar 30 from the other set.

While there is a myriad of possibilities as to, to what dimensions the railroad tie 10 is to be made, FIGS. 8 through 11 depict the preferred dimensions in centimeters. The Table depicts the tolerances for the railroad tie 10 made of the preferred dimensions.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.

Although the embodiment herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.

TABLE
Dimensional Characteristics	Tolerances
Railroad tie length immediately after stage of conveying	±6	mm
pre-stressed form
Cross-sectional dimension of the railroad tie	±3	mm
Position of the geometric center of the rebars compared	±3	mm
to the geometric center of concrete section
Cover of the rebars	±5	mm
Straightforwardness of lateral direction of railroad tie	±6	mm
Concavity or convexity of rail seat section in any direction	±0.5	mm
Inward slope of rail seat section	1 in ± 400
Deflection and slope of rail seat section along the	1 in 100
longitudinal length
Distance between central axis of rail seat section and the	−0.25	mm
location of imposing connection system force on railroad	±0.75	mm
Change range of width on sleeper	Max 6 mm

Claims

1. A railroad tie comprising:

(a) an monolithic elongate tie body defined by an elongate top surface, a substantially flat elongate bottom surface, a pair of opposing elongate side surfaces connecting the longitudinal edges of the top and bottom surfaces, and a pair of opposing end surfaces connecting the lateral edges of the top, bottom and side surfaces, the tie body longitudinally divided into: (i) a pair of end sections, the top surface of each end section longitudinally divided into: (aa) a rail seat section whereon a rail is fixedly mounted; (bb) a proximal surface section sloping downwards as it extends longitudinally from a lateral edge of the rail seat section; and (cc) a distal surface section interconnecting the other lateral edge of the rail seat section and the top edge of the corresponding end surface, the distal surface section sloping downwards from the rail seat section to the end surface; and (ii) a mid section interconnecting the pair of end sections, the mid section being narrower than the pair of end sections; and

(b) a plurality of elongate rebars cast within the tie body longitudinally wherein the rebars are horizontally and vertically aligned.

2. The railroad tie of claim 1 wherein, the tie body is made of pre-stressed concrete.

3. The railroad tie of claim 1 wherein, the rebars are made of steel.

4. The railroad tie of claim 1 wherein, a lateral groove extends from each lateral edge of each rail seat section, the groove is of uniform cross-section, the lateral edge of the groove terminating in a lateral ridge of uniform cross-section, the proximal and distal surface sections extending from the lateral edges of the respective ridges.

5. The railroad tie of claim 1 wherein, the rail seat section is rectangular.

6. The railroad tie of claim 1 wherein, the mid section is of uniform trapezoidal cross-section.

7. The railroad tie of claim 1 wherein, at any point along the length of the tie body, the width of the top surface is lesser than that of the bottom surface.

8. The railroad tie of claim 1 wherein, the width of the top surface of the mid section is lesser than that of the rail seat section.

9. The railroad tie of claim 1 wherein, the width of the proximal surface section extending from the lateral edge of the rail seat section is greater than that of the proximal surface section connecting the top surface of the mid section.

10. The railroad tie of claim 1 wherein, the width of the distal surface section extending from the lateral edge of the rail seat section is greater than that of the distal surface section connecting the end surface.

11. The railroad tie of claim 1 wherein, the slope of the proximal and distal surface sections is steeper as they extend downwardly from the respective lateral edges of the rail seat section; the slope being steeper till a portion along the length thereof.

12. The railroad tie of claim 1 wherein, the rebars are divided into a plurality of sets wherein, each set comprises a plurality of horizontally aligned rebars, and each set is disposed one below another.

13. The railroad tie of claim 12 wherein, the plurality of sets comprises two sets.

14. The railroad tie of claim 12 wherein, each set comprises three rebars.

15. A railroad tie comprising:

(a) an monolithic elongate tie body made of pre-stressed concrete, the tie body defined by an elongate top surface, a substantially flat elongate bottom surface, a pair of opposing elongate side surfaces connecting the longitudinal edges of the top and bottom surfaces, and a pair of opposing end surfaces connecting the lateral edges of the top, bottom and side surfaces, the tie body longitudinally divided into: (i) a pair of end sections, the top surface of each end section longitudinally divided into: (aa) a rectangular rail seat section whereon a rail is fixedly mounted; (bb) a proximal surface section sloping downwards as it extends longitudinally from a lateral edge of the rail seat section; and (cc) a distal surface section interconnecting the other lateral edge of the rail seat section and the top edge of a corresponding end surface, the distal surface section sloping downwards from the rail seat section to the end surface; and (ii) a mid section interconnecting the pair of end sections, the mid section being of uniform cross-section, the mid section being narrower than the pair of end sections, the mid section being of uniform trapezoidal cross-section; and

(b) a plurality of elongate steel rebars cast within the tie body longitudinally wherein the rebars are divided into a plurality of sets wherein, each set comprises a plurality of horizontally aligned rebars, each set is disposed one below another such that the rebars are vertically aligned too.