US3558050A

US3558050A - Rail support device

Info

Publication number: US3558050A
Application number: US768689A
Authority: US
Inventors: Roger Paul Sonneville
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-10-31
Filing date: 1968-10-18
Publication date: 1971-01-26
Anticipated expiration: 1988-01-26
Also published as: FR1550287A; ES358901A1; SE343352B; DE1806424A1; BE720924A

Abstract

Railway track support device wherein the tie has a substantially vertical passageway for receiving the head and a part of the shank of a tightening-down bolt of rail-fastening means and a substantially horizontal passageway intersecting the vertical passageway. An elastically yieldable metal strip is interposed between said head and the upper face of the horizontal passageway. This strip bears on said upper face when a nut is tightened on said bolt.

Description

United States Patent [72] Inventor Roger Paul Sonneville 5 Rue Maurice Ravel 92, Saint Cloud, France {21] Appl. No. 768,689 [22] Filed Oct. 18, 1968 [45] Patented Jan. 26, 1971 [32] Priority Oct. 31, 1967 [33] France [31] 126493 [54] RAIL SUPPORT DEVICE 8 Claims, 3 Drawing Figs.

[52] US. Cl 238/349, 238/283 [51] Int. Cl E0lb 9/30 [50] Field ol'Search 238/117, 310, 315, 331,349, 350, 283

[56] References Cited UNITED STATES PATENTS 1,220,443 3/1917 Miller 238/343 2,132,571 10/1938 Maney r 238/349 2,479,932 8/1949 Hunnicutt r 238/349 2,656,115 10/1953 Sonneville 238/351 3,039,695 6/1962 Harmsen 238/117 3,147,921 9/1964 Delcroix.... 238/310 3,362,639 H1968 Van Sant 238/349 FOREIGN PATENTS 1,110,506 10/1955 France 238/349 Primary Examiner-Arthur L. LaPoint Assistant ExaminerRichard A. Bertsch Att0rneyRobert E Burns RAIL SUPPORT DEVICE The present invention relates to devices for fastening rails to railway sleepers or ties.

As concerns wood sleepers, a coach-screw screwed in the wood is a conventional means for fastening the rail to the railway sleeper. Unfortunately, whenit is employed alone, the coach-screw lacks elasticity and to maintain the rail firmly integral with the sleeper, frequent tightening is necessary.

This lack of elasticity of the coach-screw is remedied by interposing between, on one hand, the head of the screw and the base of the rail and, on the other hand, a rear support face on the rail support, a fastening member consisting of a strip of spring steel. However, this fixing by means of a fastening member and coach-screw also has serious drawbacks due above all to the very principle of the anchoring of the coachscrew screwed in the wood of the sleeper. As it is subjected to a practically static and permanent tensile stress on the part of the elastically yieldable fastening member, the coach-screw tends to move gradually out of the wood. This concerns a loosening due to the gradual and irreversible plastic deformation of the wood inherent in its capillary and cellular structure under the effect of the high pressure exerted by the threads of the coach-screw. This tendency to loosen without unscrewing is aggravated by the fact that the threads of the coach-screw bare on the wood in regions in which its'structure is greatly weakened by the drilling and screw-threading which cut the fibers and capillary passages.

Note that these phenomena are accentuated by the aging of the wood.

Further, the conventional coach-screw has another funda mental drawback, namely the pitch of its screw thread is usually large, for example on the order of l2 mm. This feature of the coach-screw makes it very difficult to achieve a precise and carefully adjusted clamping, since a small rotation of the coach-screw results in a relatively large downward movement of its head. In modern track-laying yards, in which mechanical coach-screw screwing devices are used, it is practically impossible to stop the screwing just when the head of the coachscrew-the fastening strip if one is provided--touches the edge of the rail flange. Now, any excess clamping deteriorates the wood against which the threads of the coachscrew bear and there can occur a loss of elasticity of the fastener which thus accelerates the aging and loosening of the fastening device.

Despite the amplitude of the available elasticity of the fastening member, it is clear that at the end of a number of years, wear and electrolytic corrosion phenomena in the regions of contact between the spring steel strip and the rail flange result in a loss of efficiency of the fastener. This loss, or reduction in the pressure exerted on the rail, is the quicker as the response curve" of the fastener is stiffer.

These drawbacks fortunately occur only after long service in the track, but they are such as to adversely affect the economy of use of wood sleepers since the coach-screw maintenance and consolidating costs become prohibitive.

The object of the invention is to provide a support device for a railway track rail comprising in combination a sleeper and a fastener having a bolt and a nut, wherein the sleeper comprises a roughly vertical passageway for receiving the head and a part of the shank of the bolt and a roughly horizontal passageway which intersects the said vertical passageway, an elastically yieldable metal strip being interposed between the head of said bolt and the upper face of said horizontal passageway, said strip bearing on said upper face when said nut is tightened on said bolt.

Preferably, the horizontal passageway roughly parallel to the rail and in the vicinity of the middle of the vertical dimension of the sleeper, that is, in the strongest region of a wooden sleeper.

lnterposing an elastically yieldable strip between the head of the bolt and the sleeper permits distributing the tightening stress over a larger zone and consequently reducing the pressure per unit area.

Moreover, the regulation or adjustment of the clamping force is much more precise than in the case of a coach-screw since the pitch of the bolt can be chosen to be about one-fifth of that of a coach-screw.

Further features and advantages of the invention will be apparent from the ensuing description with reference to the ac-' companying drawing.

In the drawing;

FIG. I is a partial cross-sectional view of a track having a rail support device according to the invention, which is shown in its clamped-down position;

FIG. 2 is a sectional view of the device, taken along line 2-2 of FIG. I, before it is clamped down, and

FIG. 3 is a sectional view of this device taken along line 3-3 of FIG. 2.

An improved rail support device R according to the invention is shown in the drawing, this device mainly comprising a sleeper or tie T, a fastener comprising a bolt B and a nut E and a fastening member C.

A sole element S is interposed in the known manner between the rail and the sleeper and the fastening member bears on the flange of the rail and on a pad c, which is for example of elastomer.

Formed in the sleeper T are two passageways, namely a passageway I having a roughly vertical axis X-X and, in the presently-described embodiment, a circular section, and a horizontal passageway 2 having a rectangular section. The diameter of the vertical passageway is slightly greater than the diagonal of the head tof the bolt B which must be inserted in this passageway.

The horizontal passageway 2 is blind (see FIG. 2) and extends from one of the lateral faces of the sleeper in a direction parallel to the rail R. It is provided at a level slightly lower than midway up the height of the sleeper, that is, in the vicinity of the neutral axis of the cross section of the sleeper and, in the case of a sleeper of wood, in the strongest part. This horizontal passageway has a width I greater than the diameter d of the vertical passageway 1 (FIG. I). It intersects the latter and terminates in an end wall 2a located at a distance from the axis X-X which is such that the correct positioning of a strip 3 is achieved, as will be explained in more detail hereinafter (FIG. 2).

The vertical passageway extends downwardly to a level lower than the lower face of the passageway 2 so as to form a cavity 4 whose depth is slightly greater than the axial extent of the head 1 of the bolt B.

This bolt is preferably a bolt having a hammer head, such as that described in the French Pat. application No. 40,225 filed on Nov. 30, I965 by the Applicant, and including a forehead portion whose shape can be seen in FIG. 3 and which locks the bolt when clamping.

Disposed between the oblong head r of the bolt B and the upper face of passageway 2 is the elastically yieldable strip 3 which is seen in the free state in FIG. 2. This strip of spring steel is curved and has its concavity facing upwardly. It has an oblong aperture 5 whose major dimension is in the direction of the length of the strip. The dimensions of this aperture are slightly greater than those of the head t'of the bolt B so as to allow placing the latter in position.

The strip 3 has a length between one-half of the width of the sleeper and its effective width L (FIG. 2) and a width which is slightly less than the width 1 of the horizontal passageway and less than one-half the length of the strip so as to utilize in the best possible manner the weight of the spring steel.

For example, the strip 3 can have a length of about 15 cm, and a width of about 5-6 cm, the width 1 of the passageway 2 being 6 cm.

The fastener is mounted in the device according to the invention in the following manner. The strip 3 is introduced into the passageway 2 through the lateral entrance of the latter until the center of the aperture 5 is roughly in alignment with the axis of the vertical passageway I. This is advantageously carried out in the workshop when the sleeper is machined and the apertures are drilled. The strip 3 is held stationary, for example by rails driven vertically in the upper or lower face of the sleeper in the region of the ends of the strip.

When laying the track, and preferably after the rail has been placed in position, the bolt B is introduced downwardly into the vertical passageway l. The hammer head 1 passes through the aperture (FIG. 2) and at this moment a rotation of 90 of the bolt anchors the head I under the strip 3 and the forehead a abuts the longitudinal walls of the aperture 5. The fastening member C and the nut E are then placed in position by hand.

When the nut E is tightened, for example by means of a mechanical screwing device, the initially curved strip 3 progressively straightens and is finally applied throughout its length against the upper face of the passageway 2, whereas the fastener member C bends downwardly so as to come into contact with the edge of the rail flange (FIG. 1).

The initial curvature of the strip 2, its initial camber (FIG. 2) and its thin thickness are so calculated and arranged that when the head I of the bolt B exerts the force required for correctly clamping down the fastening member C, namely usually between 1,200 and L500 kg., the strip L is perfectly plane and exerts on upper face of the passageway 2 a pressure which is as uniform as possible without reaching the elastic limit of the treated spring steel of the strip 3. It is of course of interest, though this has not been shown in the drawing, to use a strip 3 of variable section obtained by deformation of the cross section or from a rolled steel having a variable thickness, so that this strip has a higher modulus of inertia in its part (which is subjected to the highest stress and weakened by the aperture 5 than at its ends where it is subjected to practically no stress.

it is easy to realize that the invention, one embodiment of which has just been described, achieves the object, that is, the assembly of the sleeper, the bolt B and the strip 3 does not have the drawbacks of the coach-screw support and fastening device it is intended to replace indeed:

The tensile force exerted upwardly by the bolt fixing the rail is transmitted to the sleeper through the strip 3 in the form of an almost uniform very low pressure, since it is distributed over a large area. A tensile force of 1,500 kg. on the bolt therefore results a pressure of the order of kg./sq. cm. exerted by the strip on the wood in the soundest and hardest part thereof. This pressure is not only considerably less than that exerted by the screw threads of a coach-screw subjected to the same tensile fore force but also very greatly less than the pressure which results in a plastic deformation of the wood. In this way, a stable anchoring is achieved with certainty throughout the useful life of the wooden sleeper. The device according to the invention can be moreover adjusted at any moment; the retightening of the bolt to compensate possible slackenings having no destructive effect on the wood of the sleeper as in the case of the coach-screw.

The adjustment of the tensile force exerted by the bolt, by the screwing of the nut is much easier and more precise than with a coach-screw, since the pitch of the bolt is about onefifth of that of a conventional coach-screw.

if the anchoring device according to the invention is associated, as in the foregoing description, with the aforementioned fastening member and if the elastically yieldable strip 3 is given characteristics close to those of this fastening member, an effective amplitude of elasticity is imparted to the assembly which is close to double that presently obtained with the same fastening member clamped down by a simple coachscrew.

The device according to the invention is therefore much less sensitive than the known device to irregularities in the clamping when laying the track and to the effects of slackening due to aging and wear. The effective life of the sleeper and its fastening means is consequently markedly prolonged with a reduction in and a simplification of the maintenance operations which largely compensates the slightly higher price of the fastener according to the invention.

The advantages of the improved rail support device according to the invention have been above all explained in the case of a wooden sleeper. it is clear that some of these advantages, and in particular the increased elasticity, can also be put to use in sleepers of concrete or in supports considered as too rigid. its utilization can also facilitate the use of welded rails of great length.

It is clear that many modifications can be made to the embodiment of such a support assembly. Among other things, the shapes, dimensions and orientations of the passageways can be modified and adapted to the conditions of utilization and to the forms of the bolts and strips employed. Moreover. although the fact of constructing the passageway 2 in the form of a blind cavity facilitates the positioning of the strip 3, this arrangement is not absolutely essential and this passageway can communicate with the two opposite lateral faces of the sleeper.

Although a specific embodiment of the invention has been described, many modifications and changes may be made therein without departing from the scope of the invention.

I claim: 7

l. A railway track rail support device comprising in combination a tie and rail fastening means including a nut, a bolt having an oblong head and a shank, and a fastener located around said bolt and between said nut and the upper faces of the tie and of the adjacent flange of the rail, said tie having a substantially vertical passageway for receiving said head and a part of said shank and a substantially horizontal passageway which has an upper face and intersects the said vertical passageway, an elastically yieldable metal strip interposed between said head and said upper face of the horizontal passageway, said strip having in its center part an oblong opening whose length is slightly greater than the length of said head of said bolt and whose width is slightly greater than the width of said head but less than the length of said head, said metal strip being curved, when said fastening means is not yet tightened down, and having a concave face directed toward said upper face of the horizontal passageway, said metal strip bearing throughout its surface on said upper face when said nut is tightened on said bolt.

2. A device as claimed in claim 1, wherein said horizontal passageway is blind and extends from one lateral face of the tie beyond said vertical passageway an extent which allows placing said metal strip in position.

3. A device as claimed in claim 1, wherein said vertical passageway extends beyond the bottom of said horizontal passageway an extent sufiicient to accommodate said head of said bolt and allow rotation of said head under said metal strip.

4. a device as claimed in claim 1, wherein said strip has a length between one half of the width of said tie and the effective width of the tie.

5. A device as claimed in claim 1, wherein said strip has a width slightly less than the width of said horizontal passageway.

6. A device as claimed in claim 1, wherein said strip has a variable cross section which decreases from its center part to its ends.

7. A device as claimed in claim 1, where in said strip has a width less than one half of the length of said strip.

8. A railway track rail support device comprising in combination a tie and rail fastening means including a nut, and a bolt having a head and a shank, said tie having a substantially vertical passageway for receiving said head and a part of said shank and communicating only with horizontal surfaces of said tie, and a substantially horizontal passage communicating only with vertical surfaces of said tie and having an upper face at an intersection with said vertical passageway, an elastically yieldable metal strip interposed betweensaid head and said upper face and bearing on said upper face when said nut is tightened on said bolt, said metal strip having an opening therein, and means for passing the head of the bolt through said opening in a downward direction and for securing said bolt against subsequent removal upwardly through said open-

Claims

1. A railway track rail support device comprising in combination a tie and rail fastening means including a nut, a bolt having an oblong head and a shank, and a fastener located around said bolt and between said nut and the upper faces of the tie and of the adjacent flange of the rail, said tie having a substantially vertical passageway for receiving said head and a part of said shank and a substantially horizontal passageway which has an upper face and intersects the said vertical passageway, an elastically yieldable metal strip interposed between said head and said upper face of the horizontal passageway, said strip having in its center part an oblong opening whose length is slightly greater than the length of said head of said bolt and whose width is slightly greater than the width of said head but less than the length of said head, said metal strip being curved, when said fastening means is not yet tightened down, and having a concave face directed toward said upper face of the horizontal passageway, said metal strip bearing throughout its surface on said upper face when said nut is tightened on said bolt.

3. A device as claimed in claim 1, wherein said vertical passageway extends beyond the bottom of said horizontal passageway an extent sufficient to accommodate said head of said bolt and allow rotation of said head under said metal strip.

8. A railway track rail support device comprising in combination a tie and rail fastening means including a nut, and a bolt having a head and a shank, said tie having a substantially vertical passageway for receiving said head and a part of said shank and communicating only with horizontal surfaces of said tie, and a substantially horizontal passage communicating only with vertical surfaces of said tie and having an upper face at an intersection with said vertical passageway, an elastically yieldable metal strip interposed between said head and said upper face and bearing on said upper face when said nut is tightened on said bolt, said metal strip having an opening therein, and means for passing the head of the bolt through said opening in a downward direction and for securing said bolt against subsequent removal upwardly through said opening.