GB1575654A

GB1575654A - Base plate for bolt and clip arrangement for elastically fastening rails

Info

Publication number: GB1575654A
Application number: GB2329777A
Authority: GB
Original assignee: Kawasaki Steel Corp
Current assignee: JFE Steel Corp
Priority date: 1976-07-14
Filing date: 1977-06-01
Publication date: 1980-09-24
Also published as: JPS5312104U; FR2358509A1; JPS5543124Y2; FR2358509B1; DE2729357A1; DE2729357B2; BR7704584A; DE2729357C3

Description

(54) BASE PLATE FOR BOLT AND CLIP ARRANGEMENT FOR ELASTICALLY FASTENING RAILS (71) We, KAWASAKI STEEL CORPORA TION, of No. 1-28, 1, Chome, Kitahonmachi-Dori, Fukiai-Ku, Kobe City, Japan, a company organized according to the laws of Japan, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a base plate adapted to receive a bolt and clip arrange ment for elastically fastening a flanged rail to a support member.

Rails for railways, and more particularly tracks for overhead travelling cranes, are often elastically fastened by means of spring clips to beams having a steel frame construction or to girders for the cranes. With the development of iron sleepers, such elastic fastening has been widely used for tracks in factories or for general purpose rails, with the aid of base plates for the clips which are embedded in concrete sleepers.

Conventional base plates used for this purpose are formed with an engagement groove for receiving a T-head of a fastening bolt in order to support a reoction force which is derived from the clamp action of a spring clip used for restraining a flange of the rail. The engagement groove of the groove or T-slot consisting of a groove having a width which is slightly larger than the outer diameter of the shank of the bolt, and an enlarged bottom groove which is substantially commensurate in size with the T-head of the bolt. Such base plates have necessarily been produced on the tables of machine tools which enable the plates to be securely mounted for machining. It has been impossible for base plates having such a T-shaped groove to be drop forged by means of a single die.

Base plates having the above described T-shaped groove may be produced by casting. However, the mechanical strength of the cart base plate is not generally sufficient to support the high reaction force which acts on the base plate when it is used for fastening rails. A drop forged base plate may be machined to form the T-shaped groove for the purpose of producing a finished base plate which has the required mechanical strength. However individual machining of the T-shaped grooves of numerous base plates introduces an expense which cannot generally be accepted for practical purposes. It is desirable therefore, to provide base plates having the required mechanical strength which can be produced by drop forging with a single die and which do not require any expensive machining of the slot.

According to the present invention there is provided a base plate adapted to receive a bolt and clip arangement for elastically fastening a flanged rail to a support member, which base plate comprises: (i) a thin bed plate capable of attachment to the support member and including a pair of limbs and a body portion connecting the limbs; and (ii) a pair of jaws which extend upwardly from the respective limbs and which have respective inner faces which together defined an upwardly tapered slot adapted to receive and engage the bolt head, and respective side faces for positioning adjacent a side of the flanged rail, wherein the limbs and that part of the body portion adjacent the jaws together define a recess to permit insertion of the bolt in the slot, and wherein the bed plate is provided with peripheral upwardly extending ribs and, at a position remote from the jaws, with an upwardly extending ridge for supporting a first end of the clip when the clip is positioned on the bolt with the second clip end in contact with the rail.

Preferably the inner faces of the jaws have rounded tapered shoulders. These are preferably continuously upwardly tapered to facilitate, in the case where the base plate is produced by forging, the removal of the forging die from the slot.

The ribs and ridge of the bed plate may result in the collection of fluid on the surface of. the plate. Accordingly it is preferred that the ridge is provided with a notch to permit the draining of fluid which has collected on the bed plate. It is preferred, tooi that the recess is part rectangular in cross section to facilitate the insertion of the bolt, preferably a T-head bolt, in the slot.

In certain rail systems, shims are inserted between the jaws of the base plates and the rail flanges in order to adjust the distance between the rails. In such systems it is preferred that the jaws are curved to co-operate with the shim to prevent the shim from moving out of position.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example to the accompanying drawings in which: Figure 1 is a plan view of a track elastically fastened to a girder by means of clips supported on base plates according to the invention; Figure 2 is an enlarged sectional view taken along the line 2-2 in Figure 1; Figure 3 is an enlarged sectional view taken along the line 3-3 in Figure 1; Figure 4a is a plan view of a preferred embodiment of the base plate according to the invention; Figure 4b is a side elevation of the base plate of Figure 4a -as viewed in the direction of the arrow 4b; Figure 4c is a sectional view of the base plate of Figure 4a taken along the line 4c-4c;; and Figure Sa and 5b are respectively front and side elevations of a T-head bolt preferably used in combination with base plates according to the invention.

- 'R;eferring to Figures 1, 2 and 3, there are shown flanged rails 1 and 11 connected by connecting plates 4 and bolts 5 (Figure 1), which rails are elastically clamped or fastened through a tie pad 3 (Figures 2 and 3) to a girder 2 for a crane by means of spring clips or retainers 8 using T-bolts 7, nuts 9 and washers 10 supported on base plates 6 according to the invention.

The base plate 6 according to the invention comprises a pair of jaws 11 with ffppòsed inner faces and with respective side faCes - fdr positioning adjacent the flanged rails 1 or 11. The inner faces define therebetween a bplt engagement groove or slot 12 which is upwardly tapered as shown in Figures 4a and 4b. The slot 12 is open at the bottom, being defined there by the pair of limbs (not numbered) from which the jaws upwardly extend, and by the body portion (not numbered) of a thin bed plate 13. The limbs and that part of the body portion which is adjacent the jaws 11 define a part rectangular recess 14 which communicates with the slot 12.

The slot 12 has at its bottom the largest width b1 and at its top the smallest width b2. Stepped shoulders 15 intermediate the top and the bottom of the slot 12 are preferably formed in rounded tapers as shown in Figure 4b. It is also preferable to provide slopes t in the inside of the slot for facilitating drawing or removing a drop forging die from the forged base plate. The bed plate 13 is provided along one periphery opposite th jaws 11 with a ridge 16 for supporting one end of the spring clip 8.

The above arrangement makes it possible to use a unitary die for producing the base plate by drop forging. As can be seen from Figure 4c the thickest part of the base plate is at the jaws 11, which are much thicker than the bed plate 13. Such a considerable difference in thickness may cause a thermal contraction strain in the plate during cooling after hot forging. To alleviate this problem the thin bed plate is provided at its periphery between the ridge 16 and the jaws 11 and along the recessed portion 14 with upwardly extending ribs 17 and 18, so that the bed plate is substantialy surrounded by the ribs 17, 18 and ridge 16. Thus the bed plate 13 is effectively reinforced by these ribs and the ridge, so enabling the bed plate to be of thinner construction.Even if the bed plate were not of such thin construction, the ribs and ridge would effectively alleviate the contraction strain in the plate.

In order to prevent rainwater from collecting in the depression on the plate surrounded by the ribs and ridge, the ridge 16 is, for example, preferably provided at its mid portion with a notch 19.

In use, the base plates 6 are securely fixed onto the girder 2 by welding along their peripheries p, q and r as shdwn in Figure 4a. One pair of plates 6 is arranged on the girder 2 spaced at a predetermined distance which is substantially equal to the width of flanges of the rails 1 (Figure 2) or at a distance which is sufficient to accom odate the flange of the rail and gauge blocks or shims 20 as spacers (Figure 3). After the tie pad 3 has been located between the plates 6, the rails 1 and 1' are positioned on the pad 3 and then their flanges are retained by means of the spring clips 8 to fix the rails relative to the girder 2.

It is clear from a comparison of Figure 2 with Figure 3 that the bolts 7, T-head in the embodiment shown, are not always vertical with respect to the plane of the bed plate; they may often assume tilted positions. Accordingly, shoulders 22 of the T head 21 of the bolt 7 are preferalily rounded so as to be in point contact with the shoulders 15 of the jaws 11 of the base plate as shown in Figures Sa and 5b; thereby there is ensured a positive fastening of the rails even if the T-head bolts are slightly tilted, and vertical movements of the rails 1 and 1l due to elastic deformation of the tie pad 3 are acommodated.

The spring clip 8 as shown in Figures 2 and 3, which is used in combination with the base plate of the invention, has a front (second) end portion which is slightly downwardly inclined to be, in use, in contact with the upper surface of the flange of the rail. The clip is also formed with an apen ture through which the shank of the T-head bolt passes; adjacent its aperture the clip is bent substantially perpendicularly to the plane of its aperture defining portion, and the end of the bent portion is further bent back upwardly to form a first end (a Ushaped edge in section) which is adapted to engage the ridge 16 of the base plate 6.

The spring clip 8 which therefore respectively engages the flange of the rail and the base plate at its front (second) and rear (first) ends is clamped in position by tightening the nut 9 threadedly engaged with the bolt 7, the T-head of which engages the jaws of the base plate, so that the rails 1, 11 are elastically fastened to the girder 2. Such an operation of the clip 8a is well known by those skilled in the art, so that it will not be described in further detail.

Adjusting shims are often interposed between the jaws 11 of the base plates and the flanges of the rails 1, 11 so as to adjust the track-gauge or the distance between the rails. In this case it is required to prevent the shims from being raised. To this end the front ends of the jaws 11 of the base plate preferably have curved or convex surfaces 23 and the surface of the shim to be in contact therewith is in the form of a curved or concave surface in mating relationship to the curved surface of the base plate, as shown in Figures 3 and 4c.

In the embodiments of the invention as described above, the ridge and ribs which are formed integrally with and surround the bed plate serve to eliminate the thermal contraction strain after hot forging which is caused by the considerable difference in thickness between the jaws and remaining portions of the base plate; the thickness of the jaws is much greater than that of the remaining portions since the jaws are exclusively subjected to the reaction force of the elastic fastening of the rails. The bolt engagement slot between the jaws, which has no bottom wall and so forms a through opening, makes it possible to use a single die for drop forging and so facilitates massproduction of the base plates.Moreover, the bolt engagement slot, by virtue of having no bottom wall, serves to provide an appropriate crowbar receiving notch and hence facilitates removal of the base plate from the girder by means of a crowbar or lever.

Such removal is necessary after gauging the weld in the even of incomplete welding of the base p]ate to the girder or on replaces ment of worn base plates. Accordingly the bolt engagement slot makes it easy to repair the rail or track assembly, which is advantageous in production and use of the assembly. Furthermore, the ribs at the peripheries of the base plate facilitate fillet welding around the bed plate and prevent flashing or burring around the bed plate due to flowing out of the weld, which would otherwise result in an unaesthetic appearance. The configuration of the bolt engagement slot in conjunction with the recess of the base plate serves to facilitate the insertion of a T-head bolt into the slot, and so may improve the efficiency of assembly rail systems incorporating the base plates of the invention.

The specific embodiment as hereinbefore described thus provides a base plate for a bolt and clip arrangement for electrically fastening a rail to a support member, which base plate is generally inexpensive to manufracture without sacrificing mechanical strength, easy to install, maintain, repair and replace, and rugged and durable in use.

Further, the base plate is substantially devoid of the thermal contraction strain which has hitherto been caused in similar plates by the considerable difference in thickness between the jaws and remaining portion of the plate, which makes it possible to use a single drop forging die to facilitate mass-production of the plate. In addition, the base plate is of a configuration which will receive a crowbar so that the plate may be removed from, for example, a girder by a crowbar in the event of in complete welding of the base plate to the girder or when it is required to replace a worn base plate. The plate also has a ridge and ribs at its peripheries to facilitate fillet welding around the base plate and to prevent a flash or burr around the plate due to flowing out of weld which would otherwise result in a fixed plate having an un-aesthetic appearance. The recess and slot of the base plate facilitate the insertion of for example a T-head bolt into the slot, thereby enabling an improvement to be made in the efficiency of assembly and use of a rail system incorporating such base plates.

WHAT WE CLAIM IS 1. A base plate adapted to receive a bolt and clip arrangement for elastically

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. head 21 of the bolt 7 are preferalily rounded so as to be in point contact with the shoulders 15 of the jaws 11 of the base plate as shown in Figures Sa and 5b; thereby there is ensured a positive fastening of the rails even if the T-head bolts are slightly tilted, and vertical movements of the rails 1 and 1l due to elastic deformation of the tie pad 3 are acommodated. The spring clip 8 as shown in Figures 2 and 3, which is used in combination with the base plate of the invention, has a front (second) end portion which is slightly downwardly inclined to be, in use, in contact with the upper surface of the flange of the rail. The clip is also formed with an apen ture through which the shank of the T-head bolt passes; adjacent its aperture the clip is bent substantially perpendicularly to the plane of its aperture defining portion, and the end of the bent portion is further bent back upwardly to form a first end (a Ushaped edge in section) which is adapted to engage the ridge 16 of the base plate 6. The spring clip 8 which therefore respectively engages the flange of the rail and the base plate at its front (second) and rear (first) ends is clamped in position by tightening the nut 9 threadedly engaged with the bolt 7, the T-head of which engages the jaws of the base plate, so that the rails 1, 11 are elastically fastened to the girder 2. Such an operation of the clip 8a is well known by those skilled in the art, so that it will not be described in further detail. Adjusting shims are often interposed between the jaws 11 of the base plates and the flanges of the rails 1, 11 so as to adjust the track-gauge or the distance between the rails. In this case it is required to prevent the shims from being raised. To this end the front ends of the jaws 11 of the base plate preferably have curved or convex surfaces 23 and the surface of the shim to be in contact therewith is in the form of a curved or concave surface in mating relationship to the curved surface of the base plate, as shown in Figures 3 and 4c. In the embodiments of the invention as described above, the ridge and ribs which are formed integrally with and surround the bed plate serve to eliminate the thermal contraction strain after hot forging which is caused by the considerable difference in thickness between the jaws and remaining portions of the base plate; the thickness of the jaws is much greater than that of the remaining portions since the jaws are exclusively subjected to the reaction force of the elastic fastening of the rails. The bolt engagement slot between the jaws, which has no bottom wall and so forms a through opening, makes it possible to use a single die for drop forging and so facilitates massproduction of the base plates.Moreover, the bolt engagement slot, by virtue of having no bottom wall, serves to provide an appropriate crowbar receiving notch and hence facilitates removal of the base plate from the girder by means of a crowbar or lever. Such removal is necessary after gauging the weld in the even of incomplete welding of the base p]ate to the girder or on replaces ment of worn base plates. Accordingly the bolt engagement slot makes it easy to repair the rail or track assembly, which is advantageous in production and use of the assembly. Furthermore, the ribs at the peripheries of the base plate facilitate fillet welding around the bed plate and prevent flashing or burring around the bed plate due to flowing out of the weld, which would otherwise result in an unaesthetic appearance. The configuration of the bolt engagement slot in conjunction with the recess of the base plate serves to facilitate the insertion of a T-head bolt into the slot, and so may improve the efficiency of assembly rail systems incorporating the base plates of the invention. The specific embodiment as hereinbefore described thus provides a base plate for a bolt and clip arrangement for electrically fastening a rail to a support member, which base plate is generally inexpensive to manufracture without sacrificing mechanical strength, easy to install, maintain, repair and replace, and rugged and durable in use. Further, the base plate is substantially devoid of the thermal contraction strain which has hitherto been caused in similar plates by the considerable difference in thickness between the jaws and remaining portion of the plate, which makes it possible to use a single drop forging die to facilitate mass-production of the plate. In addition, the base plate is of a configuration which will receive a crowbar so that the plate may be removed from, for example, a girder by a crowbar in the event of in complete welding of the base plate to the girder or when it is required to replace a worn base plate. The plate also has a ridge and ribs at its peripheries to facilitate fillet welding around the base plate and to prevent a flash or burr around the plate due to flowing out of weld which would otherwise result in a fixed plate having an un-aesthetic appearance.The recess and slot of the base plate facilitate the insertion of for example a T-head bolt into the slot, thereby enabling an improvement to be made in the efficiency of assembly and use of a rail system incorporating such base plates. WHAT WE CLAIM IS

1. A base plate adapted to receive a bolt and clip arrangement for elastically

fastening a flanged rail to a support member, which base plate comprises: (i) a thin bed plate capable of attachment to the support member and including a pair of limbs and a body portion connecting the limbs; and (ii) a pair of jaws which extend upwardly from the respective limbs and which have respective inner faces which together define an upwardly tapered slot adapted to receive and engage the bolt head, and respective side faces for positioning adjacent a side of the flanged rail, wherein the limbs and that part of the body portion adjacent the jaws together define a recess to permit insertion of the bolt in the slot, and wherein the bed plate is provided with peripheral upwardly extending ribs and, at a position remote from the jaws, with an upwardly extending ridge for supporting a first end of the clip when the clip is positioned on the bolt with the second clip end in contact with the rail.

2. A base plate according to claim 1 wherein the inner faces of the jaws have rounded tapered shoulders.

3. A base plate according to claim 1 or 2 which is a forged artifact.

4. A base plate according to claim 3 wherein the inner faces of the jaws ;are continuously upwardly tapered to facilitate removal of a forging die from the slot.

5. A base plate according to any one of the preceding claims wherein, in the plane of the bed plate, the recess is part rectangular in cross section.

6. A base plate according to any one of the preceding claims wherein the ridge is provided with a notch to permit the draining of fluid collected on the bed plate.

7. A base plate according to any one of the preceding claims wherein the side faces of the jaws are curved to permit co-operation with a shim adapted for disposition between the base plate and the rail.

8. A base plate according to claim 1 substantially as described with reference to Figures 1, 2, 3, 4a, 4b or 4c of the accompanying drawings.

9. A base plate according to claim 1 substantially as described with referance to

10. A rail system comprising a securing means which incorporates a base plate according to any one of the preceding claims.