US3866830A

US3866830A - Elastomeric railroad crossing structure

Info

Publication number: US3866830A
Application number: US395207A
Authority: US
Inventors: Richard D Hein; Gary L Fordyce
Original assignee: General Tire and Rubber Co
Current assignee: Aerojet Rocketdyne Holdings Inc
Priority date: 1973-09-07
Filing date: 1973-09-07
Publication date: 1975-02-18
Anticipated expiration: 1992-02-18
Also published as: GB1469784A; DE2442660A1; ZA743412B; ES427844A1; AU472929B2; DE2442660B2; CA1008832A; JPS5336641B2; DE2442660C3; AU7144474A; JPS5055006A

Abstract

A railroad crossing structure which includes a plurality of elongated center section pad members and a plurality of elongated outside field section pad members. The pad members are of width substantially the same as the center spacing between adjacent cross ties which are fastened to and span adjacent cross ties. Each pad member comprises an elongated arch member having horizontal flanges extending along each side of the arch member which is adapted for respective connection to adjacent cross ties with the longitudinal axis of the arch member disposed substantially parallel to the axes of the ties. A plurality of tension support rods are connected in chordal position across the arch of the arch member and along the flanges which are adapted to support the arch member against spreading with consequent vertical deflection when a vertical load is imposed downwardly on the arch member. A rectangular elastomeric pad body corresponding in shape to the length and width of the arch member and flanges is bonded to the upper surfaces and the arch member.

Description

United States Patent Hein et al.

[ Feb. 18, 1975 Primary ExaminerRobert S. Ward, Jr. Assistant ExaminerRichard A. Bertsch [5 7] ABSTRACT A railroad crossing structure which includes a plurality of elongated center section pad members and a plurality of elongated outside field section pad members. The pad members are of width substantially the same as the center spacing between adjacent cross ties which are fastened to and span adjacent cross ties. Each pad member comprises an elongated arch member having horizontal flanges extending along each side of the arch member which is adapted for respectiveconnection to adjacent cross ties with the longitudinal axis of the arch member disposed substantially parallel to the axes of the ties. A plurality of tension support ods' are connected in chordal position across the arch of the arch member and along the flanges which are adapted to support the arch member against spreading with consequent vertical deflection when a vertical load is imposed downwardly on the arch member. A rectangular elastomeric pad body corresponding in' shape to the length and width of the arch member and flanges is bonded to the upper surfaces and the arch member.

28 Claims, 7 Drawing Figures 3 IO 26 (l PATENTEI] FEB] 8 i975 SHEET 10F 3 3,866,830 snmzor 5, mm 6 A PATENTED FEB 1 8 I975 H mm m @w PATENTEB FEB] 8IE175 sum I 3 HF ELASTOMERIC RAILROAD CROSSING STRUCTURE BACKGROUND OF THE INVENTION This invention generally pertains to composite railroad crossing structures which incorporate elastomeric materials and more specifically pertains to an improved railroad crossing structure including a plurality of structural traffic pads adapted to be fastened to adjacent railroad ties to span between the ties. Each such unit comprises an elastomeric body incorporating an integral and substantially rigid arch support member.

It has been long recognized that, where roads, streets and highways cross railroad tracks, a smooth transition of both railroad and pavement through such crossing is highly desirable even at low vehicle speeds and essential at high vehicle speeds for the sake of personal safety and to prevent vehicle and cargo damage. Various metal, concrete, wood and elastomeric structures have been devised in attempting to reduce or eliminate the problem of rough crossings. Of these the elastomeric types of structures are deemed to be superior for a number of reasons set forth below with respect to the accomplishments attained by the present invention.

DESCRIPTION OF THE PRIOR ART SUMMARY OF THE INVENTION The present invention provides a smooth railroad crossing structure which will not chip, splinter, crack, spall, corrode or rot.

The present invention also provides a railroad crossing structure which may be readily installed without heavy or specialized equipment and with minimum preparation of railroad ties as normally found in place.

The present invention also provides a structure having an improved ratio of weight to resistance to vertical compression.

The structure of the present invention may be provided of individual sections or pads with each section adapted to span and to be fastened to two adjacent railroad ties whereby a movable hinge relationship is established between the ties and such section which will allow a respective tie to deflect or pump slightly, as happens when the loaded wheels of a railway car truck passes over such tie, without loosening the attachment of the pad section to the tie.

The present invention provides individual pad sections which are sufficiently narrow in width to be installed to closely match the width of the roadway pavement.

The present invention provides a structure which may be readily adapted to railroad tracks which are either straight or curved.

LII

The present invention also may be provided with anti-skid grooves disposed parallel to roadway traffic to produce greater resistance to side skid or fish-tailing of automobile vehicles.

The foregoing and other provisions and advantages are attained in a railroad crossing structure which includes a plurality of elongated center section pad members and a plurality of elongated outside or field section pad members. The pad members are of width substantially the same as the center spacing between adjacent cross ties. The pads are fastened to and span adjacent cross ties. Each pad member comprises an elongated upwardly extendingarch member having horizontal flanges extending along each side of the arch member. Each flange is adapted for respective connection to adjacent cross ties with the longitudinal axis of the arch member disposed substantially parallel to the axes of the ties. A plurality of tension support rods are connected in chordal position across the arch of the arch member and along the flanges. The tension support rods are adapted to support the arch member against spreading with consequent vertical deflection when a vertical load is imposed downwardly on the arch member. A rectangular elastomeric pad body corresponding in shape to the length and width of the arch member and flanges is bonded to the upper surfaces of the flanges and the arch member. The pad body defines a horizontal traffic supporting surface disposed above the arch member and the flanges. The traffic supporting surface may be provided. with anti-skid grooves.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary elevational cross sectional view taken along the line 1-1 of FIG. 2 showing the center section pad of the present invention and portions of the field section pads as installed at a railroad crossing.

FIG. 2 is a plan view of a portion of a railroad crossing as provided with the crossing structure of the present invention. I

FIG. 3 is an enlarged partly sectional view of the installation as viewed in FIG. 1.

FIG. 4 is a cross sectional view as taken along the line 44 of FIG. 2.

FIG. 5 is an enlarged plan view of a field section pad as shown in FIG. 2.

FIG. 6 is an elevational partly sectional view of the field section pad shown in FIG. 5.

FIG. 7 is an elevated cross sectional view taken along the line 7-7 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT The same or functionally similar elements as illustrated in the various views of the drawings are designated with the same number.

Referring to FIGS. 1 4, there is shown a railroad crossing structure 10 of the present invention. Crossing structure 10 typically includes a pair of rails 12 supported on a plurality of cross ties 14. The rails 12 are fixed to each of the ties 14 by means of spikes l6 driven through holes in tie plates 18 whereby the offset heads of the spikes 16 serve to grip the sole flange of each rail into fixed relation against each tie plate.

Mounted between adjacent cross ties l4 and between the rails 12 are'plurality of elastomeric center section traffic pads 20. Pads 20 will be later described more 3 fully in view of the structural detail shown in FIGS. 3 and 4.

As also shown in FIGS. 1 and 2, outside the rails 12 and between adjacent cross ties 14, there are mounted a plurality of elastomeric field section traffic pads 22. The pads 22 will be later described more fully with reference to the structural detail shown in FIGS. -7.

Each of the center section traffic pads 20 is seen in FIGS. 14 to be generally rectangular in external configuration as viewed from the top, the sides and the ends. As best seen in FIGS. 3 and 4, each traffic pad 20 is a composite structure generally comprising an elastomeric body 24 which is molded to substantially a rectangular external shape and molded in bonded relation to and about a supporting arch member 26. The curve of the arch member 26 terminates on each side with a horizontally extending support flange 28.

Vertical holes are provided through the body 24 and flanges 28, through which drive spikes or screws 30 may be driven into the ties 14 to fasten the pad 20 securely to adjacent ties 14. The arch member 26 spans the space between the ties 14 with the longitudinal axis of the arch member disposed substantially parallel to the longitudinal axes of the ties 14.-

A plurality of tension support bolts or rods 32 are connected in tension across a chord of arch member 26 immediately above flanges 28 as shown in FIGS. 2 and 3. These tension support members may be carriage bolts, threaded tie rods or the like as shown and are preferably installed after the elastomer of body 24 has been molded and cured into shape and in bonded relation about arch member 26 as shown. The purpose of the tension support rods 32 is to stiffen arch member 26 by preventing any tendency of flanges 28 to spread apart when a vertical load is impressed down on traffic pad 20 and arch support member 26.

The top of traffic pad member 20 is a generally flat surface 34 in which may be molded anti-skid grooves 36 as shown. Such grooves 36 are preferably molded longitudinally along the surface 34 which is the direction of automobile traffic along the pavement and across the crossing structure as installed.

As shown in FIG. 3 the ends of the elastomeric body 24 terminate in a downwardly extending apron 38 having a water run off lip 39 extending out from its lower end. The length of the traffic pad is provided to closely fit between the rails 12 whereby the lip 40 is deflected in by the head of rail 12 as the pad 20 is installed. The lip 40 springs back into forceful contact with the web of rail 12 when the pad 20 is seated.

As shown in Hg. 4 the width of the elastomeric body 20 is provided approximately the same as the centerline spacing between the cross ties 14. When installed as shown any bulge as caused by loading of the traffic pad 20 near to its edge will bring the sides of the pad 20 into force transmitting contact with its adjacent pad. Thus, when the pads 20 are installed in close proximity as shown, a mutual reinforcing and load bearing relationship is established.

As shown in FIG. 3 the holes provided for fastening spikes 30 may be sealed from water and detritus by means of plugs 40, shown in dashed lines.

As also shown in FIGS. 2 and 3, a plurality of flexure cavities or holes 42 may be provided in the elastomeric body 24 at the thicker sections of rubber along the sides of arch member 26. The reasons for provision of these cavities include: the cavities give room for flexure of the elastomer under loading and the cavities reduce the overall weight and amount of elastomer used in the traffic pad 20.

When the crossing structure 10 is installed as a curving rather than straight section of track, the ends of the traffic pads 20 are installed more closely together on the inside of the curve than the outside or by drawing the arch member 26 closer together by means of tension rods 32 on the inside of the track curve. As can readily be seen, the relative spacing between adjacent cross ties will be so small as to be negligible even on sharply curved tracks.

As can be seen with reference to FIGS. 3 and 4 all the surfaces of the arch member 26 and the flanges 28 are covered with a layer of elastomer which is bonded to the metal. Though the elastomer serves no structural purpose when provided as such a layer it does serve to protect the metallic elements against corrosion.

FIGS. 1 and 2 depict the flanges 28 of traffic pad 20 supported in spaced relation above the cross ties 14 by an elastomeric pad termed a spacer or filler pad 44. Filler pad 44 may be provided of nearly any material capable of supporting automotive loading but is preferably provided of an elastomer which may be reinforced with fiber or metal as known in the art. The reason for the provision of filler pad 44 is that the traffic pad 20 is normally provided of sufficiently low height so as to be horizontally even with the tops of light weight, i.e., short height, rails and the filler pads 44 then provide increased height for traffic pad 20 when installed with heavier and taller rails.

The field (outside) section traffic pad 22 is shown in FIGS. 57. As seen by the designated numbers, much of the construction of the field section traffic pad 22 is the same as the center section traffic pad 20. As with traffic pad 20, the pad 22 is provided with an elastomeric body 24, supported by an arch support member 26. Flanges 28 are provided which are adapted to be connected to cross ties by means of spikes or screws (not shown). Tension support members 32 are provided as previously described.

As can be seen, on comparison of FIGS. 1 and 6, the track or rail end of pad 22 is provided with a solid shoulder 46 of elastomer which is adapted to abutt the head of rail 12 and provide a smooth transition between the top of the rail and the surface 34 of pad 22. The field end of pad 22 is provided with a closure wall 48. The purpose of the closure wall 48 is to prevent entry of detritus under arch member 26. Also, when the crossing structure 10 has been installed as shown in FIG. 2, the combined closures 48 on the field side of the crossing can serve as a form for pouring concrete or for tamping asphalt for the pavement (not shown) adjacent to the crossing.

When desired the ends of the arch member 26 may be rolled, crimped or beveled inwardly to some extent to provide a greater thickness of elastomer at the beginning of the supporting function of arch support 26 within the traffic pad 20 and/or 22. Such a bevel is indicated in dashed lines at 50 in FIG. 3.

The preferred material for elastomeric body 24 is neoprene, selected for its superior ozone and weathering resistance. Other weather resistant materials may be provided, however, such as certain grades of butyl rubbers, ethylene polypropylene rubbers, polysulfide rubbers, silicone rubbers and the like and dictated by effectiveness vs price. A less expensive filler material may be used as desired. Elastomeric body 24 preferably is provided of hardness in the range of about 5070 durometer, for example.

The foregoing description and drawings will suggest other embodiments and variations to those skilled in the art, all of which are intended to be included in the spirit of the invention as herein set forth.

That being claimed is:

1. An elastomeric railroad crossing pad member comprising:

A. an elongated arch member having an upwardly extending arch and including horizontal flanges extending from each side of said arch,

B. said arch member being of width substantially the same as the center spacing of adjacent railroad ties,

C. said arch member being adapted for respective connection through said flanges to adjacent railroad ties with the longitudinal axis of said arch member disposed substantially parallel to the axes of said railroad ties,

D. a plurality of tension support means connected in chordal relation across the arch of said arch member and along the tops of said flanges, and

E. an elastomeric pad body defining a horizontal upper surface and bonded to the upper surfaces of said arch and said flanges.

2. The pad member of claim 1 wherein said tension support means comprise carriage bolts connected across said arch.

3. The pad member of claim 1 wherein said tension support means comprise tie rods connected across said arch.

4. The pad member of claim 1 wherein said elastomeric pad body is neoprene.

5. The pad member of claim 1 wherein said elastomeric pad body is of 50-70 durometer hardness.

6. The pad member of claim 1 wherein grooves are defined in a longitudinal direction along said upper surface.

7. The pad member of claim 1 further including filler pads of selected thickness adapted to be disposed between said flanges and said railroad ties.

8. The pad member of claim 1 wherein the ends of said arch are beveled inwardly.

9. A railroad crossing structure including a plurality of elastomeric center section pad members and a plurality of elastomeric field section pad members with each pad member of said pad members comprising:

A. an elongated arch member having an upwardly extending arch and including horizontal flanges extending from each side of said arch;

B. said arch member being of width substantially the same as the center spacing of adjacent railroad ties;

C. said arch member being respectively connected through said flanges to adjacent railroad ties with the longitudinal axis of said arch member disposed substantially parallel to the axes of said railroad ties;

D. a plurality of tension support means connected in chordal relation across the arch of said arch member;

E. said tension support means being adapted to support said arch against spreading responsive to imposition of a vertical load downwardly on said arch member;

F. an elastomeric pad body defining a horizontal upper surface and bonded to the upper surfaces of said arch and said flanges; and i G. the arrangement being such that a mutual reinforcing and vertical load bearing relationship is established by adjacent said pad members.

10. The structure of claim 9 wherein said tension support means comprise carriage bolts connected across said arch.

l l. The structure of claim 9 wherein said tension support means comprise tie rods-connected across said arch.

12. The structure of claim 9 wherein said elastomeric pad body is neoprene.

13. The structure of claim 9 wherein said elastomeric pad body is of 50-70 durometer hardness.

14. The structure of claim 9 wherein grooves are defined in a longitudinal direction along said upper surface.

15. The structure of claim 9 further including filler pads of selected thickness disposed between said flanges and said railroad ties.

16. The crossing structure of claim 9 wherein the ends of said arch are beveled inwardly.

17. An elastomeric railroad crossing pad member comprising:

B. said arch member being adapted for respective connection through said flanges to adjacent railroad ties with the longitudinal axis of said arch member disposed substantially parallel to the axes of said railroad ties,

C. a plurality of tension support means connected in chordal relation across the arch of said arch member and along the tops of said flanges.

D. an elastomeric pad body defining a horizontal upper surface and bonded to the upper surfaces of said arch and said flanges, and

E. said pad member being adapted to establish a mutual reinforcing and vertical load bearing relationship with another said pad member when the two said pad members are adjacently connected to a common railroad tie.

18. The pad member of claim 17 wherein the ends of said arch are beveled inwardly.

19. The pad member of claim 17 wherein said tension support means comprise carriage bolts connected across said arch.

20. The pad member of claim 17 wherein said elastomeric pad body is neoprene.

21. The pad member of claim 17 wherein said elastomeric pad body is of 50-70 durometer hardness.

22. The pad member of claim 17 wherein grooves-are defined in a longitudinal directio n along said upper surface.

23. The pad member of claim 17 further including filler pads of selected thickness disposed between said flanges and said railroad ties.

24. The pad member of claim 17 wherein'sa'idtension support means comprise tie rods connected across's'aid arch.

25. The pad member of claim '24 wherein said elastomeric pad body is neoprene.

3,866,830 7 8 26. The pad member of claim 25 wherein grooves are between said flanges and said railroad tie. defined in a longitudinal direction along said upper surf 28. The pad member of claim 27 wherein said elastoace.

27. The pad member of claim 26 further including mer'c pad body of 50-70 durometer hardness" filler pads of selected thickness adapted to be disposed 5

Claims

1. An elastomeric railroad crossing pad member comprising: A. an elongated arch member having an upwardly extending arch and including horizontal flanges extending from each side of said arch, B. said arch member being of width substantially the same as the center spacing of adjacent railroad ties, C. said arch member being adapted for respective connection through said flanges to adjacent railroad ties with the longitudinal axis of said arch member disposed substantially parallel to the axes of said railroad ties, D. a plurality of tension support means connected in chordal relation across the arch of said arch member and along the tops of said flanges, and E. an elastomeric pad body defining a horizontal upper surface and bonded to the upper surfaces of sAid arch and said flanges.

4. The pad member of claim 1 wherein said elastomeric pad body is neoprene.

9. A railroad crossing structure including a plurality of elastomeric center section pad members and a plurality of elastomeric field section pad members with each pad member of said pad members comprising: A. an elongated arch member having an upwardly extending arch and including horizontal flanges extending from each side of said arch; B. said arch member being of width substantially the same as the center spacing of adjacent railroad ties; C. said arch member being respectively connected through said flanges to adjacent railroad ties with the longitudinal axis of said arch member disposed substantially parallel to the axes of said railroad ties; D. a plurality of tension support means connected in chordal relation across the arch of said arch member; E. said tension support means being adapted to support said arch against spreading responsive to imposition of a vertical load downwardly on said arch member; F. an elastomeric pad body defining a horizontal upper surface and bonded to the upper surfaces of said arch and said flanges; and G. the arrangement being such that a mutual reinforcing and vertical load bearing relationship is established by adjacent said pad members.

11. The structure of claim 9 wherein said tension support means comprise tie rods connected across said arch.

12. The structure of claim 9 wherein said elastomeric pad body is neoprene.

17. An elastomeric railroad crossing pad member comprising: A. an elongated arch member having an upwardly extending arch and including horizontal flanges extending from each side of said arch, B. said arch member being adapted for respective connection through said flanges to adjacent railroad ties with the longitudinal axis of said arch member disposed substantially parallel to the axes of said railroad ties, C. a plurality of tension support means connected in chordal relation across the arch of said arch member and along the tops of said flanges. D. an elastomeric pad body defining a horizontal upper surface and bonded to the upper surfaces of said arch and said flanges, and E. said pad member being adapted to establish a mutual reinforcing and vertical load bearing relationship with another said pad member when the two said pad members are adjacently connected to a common railroad tie.

20. The pad member of claim 17 wherein said elastomeric pad body is neoprene.

22. The pad member of claim 17 wherein grooves are defined in a longitudinal direction along said upper surface.

24. The pad member of claim 17 wherein said tension support means comprise tie rods connected across said arch.

25. The pad member of claim 24 wherein said elastomeric pad body is neoprene.

26. The pad member of claim 25 wherein grooves are defined in a longitudinal direction along said upper surface.

27. The pad member of claim 26 further including filler pads of selected thickness adapted to be disposed between said flanges and said railroad tie.

28. The pad member of claim 27 wherein said elastomeric pad body is of 50-70 durometer hardness.