CA1042402A - Wooden sleeper, particularly suitable for railway track - Google Patents
Wooden sleeper, particularly suitable for railway trackInfo
- Publication number
- CA1042402A CA1042402A CA241,851A CA241851A CA1042402A CA 1042402 A CA1042402 A CA 1042402A CA 241851 A CA241851 A CA 241851A CA 1042402 A CA1042402 A CA 1042402A
- Authority
- CA
- Canada
- Prior art keywords
- sleeper
- inserts
- insert
- wooden
- wood
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 241001669679 Eleotris Species 0.000 title claims abstract description 83
- 239000002023 wood Substances 0.000 claims abstract description 28
- 239000000463 material Substances 0.000 claims description 11
- 239000004033 plastic Substances 0.000 claims description 10
- 229920003023 plastic Polymers 0.000 claims description 10
- 238000005336 cracking Methods 0.000 claims description 6
- 230000003466 anti-cipated effect Effects 0.000 claims description 4
- 239000011121 hardwood Substances 0.000 claims description 3
- 239000013013 elastic material Substances 0.000 claims description 2
- 239000000306 component Substances 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 3
- 125000006850 spacer group Chemical group 0.000 description 3
- 208000020401 Depressive disease Diseases 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 230000009514 concussion Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000002674 ointment Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 239000011150 reinforced concrete Substances 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B9/00—Fastening rails on sleepers, or the like
- E01B9/38—Indirect fastening of rails by using tie-plates or chairs; Fastening of rails on the tie-plates or in the chairs
- E01B9/40—Tie-plates for flat-bottom rails
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B3/00—Transverse or longitudinal sleepers; Other means resting directly on the ballastway for supporting rails
- E01B3/02—Transverse or longitudinal sleepers; Other means resting directly on the ballastway for supporting rails made from wood
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Mechanical Engineering (AREA)
- Machines For Laying And Maintaining Railways (AREA)
- Railway Tracks (AREA)
- Road Paving Structures (AREA)
Abstract
Abstract of the Disclosure A wooden sleeper is disclosed which is particularly suitable for use in railway tracks or tracks for heavy machinery. In those zones of the load-bearing surface of the sleeper which are subjected to pressure in use, at least one groove or recess is provided, and at least one pad is installed in the groove or recess. The pad redirects the load from a direction per-pendicular to the wood grain to a direction parallel or oblique to the wood grain.
Description
1~4Z9~Z
Tile invention relates to a wooden sleeper used particularly in railway tracks or as a cross-tie for heavy machinery.
Wooden, steel or reinforced concrete sleepers are used in railway tracks. Wooden sleepers are usually made in the form of a solid piece and are cut in such a manner that the wood grain is always perpendicular to the direction of the railway track. Large pulsating compression forces occur in the sleepers at the points where the rails are affixed, which thereby causes plastic strain at those points. Metal sole-plates are commonly used under the rails to distribute the compression forces over a larger area of the sleeper.
However, while these sole-plates give a certain protection against premature mechanical deterioration of the sleeper, crushing of the wood will occur after the sleeper has been in use for several years. The crushing deformation may extend as deep as 20 mm and will consequently also result in weakening the mounting of the sole-plate screws. Although crushing of the wood will occur more rapidly when the wood material is soft, it also occurs in hard wood.
Prevention of plastic strain is particularly important for high speed train operation since no plastic strain is allowed in the sleepers used in railway tracks for trains travelling at a speed greater than 140 km/h.
From West German Offenlegungsschrift No. 1,910,210, there is known a wooden sleeper in which a plurality of reinforcing elements are provided which are made of a material having greater strength than wood. The elements are used where the load is applied and are perpendicular to the load-bearing surface. The spacing between the elements is at least 31.8 mm and they are usually in the form of cylindrical epoxy resin pins cast in drillings which are also perpendicular to the wood grain.
Sleepers consisting of several wooden pieces have also been used for railway tracks in order to reduce costs. Using such a technique, wood of a lower quality may be used for the sleeper. In construction of this type, however, the pressure created by the rail or sole-plate is perpendicular to the direction of the wood grain and plastic strain and crushing of the wood - 1- ~
~()4Z4(~
follow in the same manner as in one-piece sleepers.
An object of the present invention is to improve the strength and the life of wooden sleepers.
In accordance with the present invention, we provide a wooden sleeper particularly suitable for use in railway tracks or tracks for heavy machinery~ said sleeper being provided in each rail-mounting zone thereof with at least one insert of material harder than the wood of the sleeper and improving the compressive strength of the sleeper in places where anticipated loads may exceed the strength of the wood, the or each insert being wedge-shaped in cross-section, with the thin edge thereof being directed downwardly.
and being glued in a complementarily-shaped groove or recess in the rail-bearing surface of the unrestrained sleeper in a zone where high loads are to be anticipated, and each groove or recess and insert running transversely at right angles to the longitudinal centre line of the sleeper.
The inserts used in the recesses or grooves in the sleeper result in a vertically applied load being distributed over a larger area and the load direction being more favourable for the compressive strength of the wood, since this strength is 6 - 10 times higher lengthwise than crosswise of the wood grain.
The results of tests indicate that when sleepers in accordance with the invention are used in railway tracks, the plastic strain of a sleeper under the load of a rail pressing against it can be reduced almost ten times.
The inserts may be made of any suitable material which is harder than the wood used for the sleeper, for example they may be made of hard wood, of wood hardened with plastics material, or of plastics materials.
Each insert may be a single solid piece or be made up of several pieces. A
rail, when mounted on the sleeper, rests against the sleeper on a single wedge or several such wedges glued in lateral grooves cut in the sleeper .
lhe force of the load acting from the rail against the sleeper is resolved into a component perpendicular to the wood grain in the sleeper and a com-ponen~ parallel to said grain.
Each wedge-type insert consists of two or more components which may or may not be interconnected. Where use is made of wooden wedge-type inserts, the wood grains in these inserts may run laterally relative to the force acting from the rail against the sleeper. Particularly suitable for the inserts is a wood having hardness and Fracture strength improved by impregnating it with plastics material.
The inserts~ as well as the grooves made for these inserts in a sleeper may be shaped in such a manner as to prevent the inserts from falling out of the sleeper. In such a case the inserts as well as the grooves receiving these inserts may have the shape of a prism with a pentagonal base.
The rail or the plate rests against the horizontal face of the insert. Two faces opposite to this face transmit to the sleeper the force of the rail pressing against the sleeper, while the two adjacent faces are thrust faces preventing the inserts from falling out of the sleeper.
The inserts may be a little smaller in cross-section relative to the cross-section of the grooves cut in the sleeper. A layer of a binding material or an elastic spacer is sandwiched in such a case, between the insert and the bottom of the groove. This layer constitutes a spacer which may be of rubber, enabling an absolutely uniform transmission of forces from the insert to the wood of the sleeper, said spacer being at the same time a sealing layer between the insert and the sleeper. The inserts used in sleep-ers according to the invention can also fulfill an additional ~unction besides the heretofore described transmission and redirection of forces acting on the sleeper. They can be used as elements preventing the sleepers from cracking along the grain (it is generally known that sleepers tend to crack lengthwise in service under the influence of weather and under mechanical loads). This can be achieved when the contacting faces of each insert and the associated groove in the sleeper are curvilinear in contour, thus causing the insert to operate in the sleeper in a way similar to a clamp stapling the sleeper laterally.
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:
; .
- .-- 1~)4;~ Z
Figure 1 illustrates a portion of a sleeper in accordance with a first embodiment of the invention, in a vertical section along the centre line of the sleeper, with a rail supportcd thereon, and including rail-mounting elements;
Figure 2 is a plan view illustrating the same portion of the sleep-er as Figure 1 but omitting the rail and rail-mounting elements, Figures 3 to 5 are s~ctional views similar to Figure 1, but illustrating sleepers in accordance with second, third and fourth embodiments of the invention, respectively;
Figure 6 is a sectional view similar to Figure 1 but illustrating a modification of the first embodiment of the sleeper in that rubber separat-ors are included;
Figure 7 illustrates part of a sleeper in accordance with a fifth embodiment of the invention equipped with inserts preventing cracking of the sleeper in the lengthwise direction, the view being a vertical section along the line A-A in Figure 8;
Figure 8 is a plan view of the sleeper shown in Figure 7;
Figure 9 is a vertical section through the sleeper shown in Figures 7 and 8, along the line B-B in Figure 8;
Figure 10 is a plan view of a part of a sleeper in accordance with a sixth embodiment of the invention, also equipped with inserts preventing cracking of the sleeper in the lengthwise direction; and Figure 11 illustrates the sleeper shown in Figure 10 in a vertical section along the line C-C in Figure 10.
Referring firstly to Figures 1 and 2, the sleeper in accordance with the first embodiment of the invention is denoted by the reference numeral 1 and is provided with two inserts 2 positioned under each rail when the rails are mounted in position, said inserts having in cross-section the form of wedges rounded at their thin edges. Each insert 2 is fitted into a groove milled in the sleeper 1. The cross-sections of the grooves match the ~:
shapes of the inserts 2. A gap is left between the bottom of each groove and the bottom or rounded portion of the pertaining insert. The inserts 2 3. _ 4_ , 1~)4;~4V;:
extend over the whole width of the sleeper 1. ~ conventional steel sole plate 3 rests against each pair of inserts 2 and is fixed to the sleeper 1 by means of four screws 4. A rail 6 is fixed to the plate 3 by means of clamps 5.
The force F of plate 3 pressing against each insert 2 is resolved, in accordance with the principle of action of a wedge, into two force compon-ents Fl and F2, with which the side faces of inser~ 2 act on the sleeper 1.
The forces Fl and F2 are directed diagonally relative to the grain of the sleeper, and horizontal components Fll and F21 of the said forces, which horizontal components are parallel to the grain of wood, are greater than the vertical components F12 and F22, which are perpendicular to the grain. The force P is thus resolved first of all along the grain, and only a minor component thereof acts laterally to the grain. Irrespective of this favourable redirection of forces, the inserts 2 give rise also to another desired effect. The area of contact between inserts 2 and sleeper 1 is greater than the free area of plate 3. In this way the pressures per unit area over the sleeper are lower when the inserts 2 are used, than would be the case if the inserts 2 were not used and the plate 3 presses directly against the sleeper.
Referring now to Figure 3, in the sleeper according to the second embodiment there is but a single insert 2 under each rail 6, said insert consis~ing of two parts. In the sleeper of the third embodiment of the invention, shown in Figure 4~ there are six inserts 2 under the plate 3 of each individual rail 6. In this latter case, the two inserts 2a and 2b nearer each flank of the plate 3 result in an improved grip of the screws 4 in the wood, because thP wood is compressed near the said screws. In the fourth embodiment illustrated in Figure 5, both the inserts and the grooves receiving the said inserts same have a different cross-sectional shape in order to prevent the inserts 2 from falling out of the sleeper. Each insert has two oblique walls 7 near its top face, said walls resting against the faces of grooves suitably milled in sleeper 1. The inserts 2 are fitted into the sleeper by pushing them in along the centre lines of the grooves.
.. .. .
. :: ; . . ~ .. ..
~4~Z4~2 In the modification of the first embodiment, illustrated in Figurc 6, a layer of an elastic material such as rubber is sandwiched between the face of each of the grooves in the sleeper and the face of the associated insert 2, in order to absorb concussion, to serve as a seal or as an electric insulating layer.
In the fifth and sixth embodiments of the invention, illustrated in Figures 7 to 11, the inserts 2 redirect the compressive forces as hereinbefore described above, and also prevent lengthwise cracking of the sleeper. In the fifth embodiment illustrated in Figures 7 to 9, the flanks and the thin edge of each wedge-shaped insert are rounded in the longitudinal direction, i.e. transversely of the sleeper, the cross-sectional dimensions of the wedge-shaped insert being greater at its ends than at its middle portion, both widthwise and depthwise. The grooves are of course complementarily shaped and, in this way, as is illustrated in Figures 8 and 9, each insert 2 "saddles" and closes the sleeper laterally.
In the sixth embodiment illustrated in Figures 10 and 11, the flanks and the thin edges of the inserts 2 are corrugated or undulating and the grooves are complementarily shaped. The resulting protuberances and depres-sions extending in the upwards direction on and in the two flanks of each insert may be arranged so that each protuberance in one flank is opposite ~o a depression in the other (the left-hand insert in Figure 10) or so that each protuberance or depression in one flank is opposite to a protuberance or depression in the other (the right-hand insert in Figure 10). These pro-tuberances and depressions result in the sleeper 1 being clasped laterally, thus preventing lengthwise cracking thereof.
Manifestly, the invention is not restricted exclusively to the embodiments thereof hereinbefore described. ~;
Sleepers according to the invention may also be used where wooden elements have hitherto been used for the transmission of high loads directed laterally relative to the wood grain, for example as in wooden elements designed for various heavy machinery or tools, or in tracks for heavy machines. ;~
: .
Tile invention relates to a wooden sleeper used particularly in railway tracks or as a cross-tie for heavy machinery.
Wooden, steel or reinforced concrete sleepers are used in railway tracks. Wooden sleepers are usually made in the form of a solid piece and are cut in such a manner that the wood grain is always perpendicular to the direction of the railway track. Large pulsating compression forces occur in the sleepers at the points where the rails are affixed, which thereby causes plastic strain at those points. Metal sole-plates are commonly used under the rails to distribute the compression forces over a larger area of the sleeper.
However, while these sole-plates give a certain protection against premature mechanical deterioration of the sleeper, crushing of the wood will occur after the sleeper has been in use for several years. The crushing deformation may extend as deep as 20 mm and will consequently also result in weakening the mounting of the sole-plate screws. Although crushing of the wood will occur more rapidly when the wood material is soft, it also occurs in hard wood.
Prevention of plastic strain is particularly important for high speed train operation since no plastic strain is allowed in the sleepers used in railway tracks for trains travelling at a speed greater than 140 km/h.
From West German Offenlegungsschrift No. 1,910,210, there is known a wooden sleeper in which a plurality of reinforcing elements are provided which are made of a material having greater strength than wood. The elements are used where the load is applied and are perpendicular to the load-bearing surface. The spacing between the elements is at least 31.8 mm and they are usually in the form of cylindrical epoxy resin pins cast in drillings which are also perpendicular to the wood grain.
Sleepers consisting of several wooden pieces have also been used for railway tracks in order to reduce costs. Using such a technique, wood of a lower quality may be used for the sleeper. In construction of this type, however, the pressure created by the rail or sole-plate is perpendicular to the direction of the wood grain and plastic strain and crushing of the wood - 1- ~
~()4Z4(~
follow in the same manner as in one-piece sleepers.
An object of the present invention is to improve the strength and the life of wooden sleepers.
In accordance with the present invention, we provide a wooden sleeper particularly suitable for use in railway tracks or tracks for heavy machinery~ said sleeper being provided in each rail-mounting zone thereof with at least one insert of material harder than the wood of the sleeper and improving the compressive strength of the sleeper in places where anticipated loads may exceed the strength of the wood, the or each insert being wedge-shaped in cross-section, with the thin edge thereof being directed downwardly.
and being glued in a complementarily-shaped groove or recess in the rail-bearing surface of the unrestrained sleeper in a zone where high loads are to be anticipated, and each groove or recess and insert running transversely at right angles to the longitudinal centre line of the sleeper.
The inserts used in the recesses or grooves in the sleeper result in a vertically applied load being distributed over a larger area and the load direction being more favourable for the compressive strength of the wood, since this strength is 6 - 10 times higher lengthwise than crosswise of the wood grain.
The results of tests indicate that when sleepers in accordance with the invention are used in railway tracks, the plastic strain of a sleeper under the load of a rail pressing against it can be reduced almost ten times.
The inserts may be made of any suitable material which is harder than the wood used for the sleeper, for example they may be made of hard wood, of wood hardened with plastics material, or of plastics materials.
Each insert may be a single solid piece or be made up of several pieces. A
rail, when mounted on the sleeper, rests against the sleeper on a single wedge or several such wedges glued in lateral grooves cut in the sleeper .
lhe force of the load acting from the rail against the sleeper is resolved into a component perpendicular to the wood grain in the sleeper and a com-ponen~ parallel to said grain.
Each wedge-type insert consists of two or more components which may or may not be interconnected. Where use is made of wooden wedge-type inserts, the wood grains in these inserts may run laterally relative to the force acting from the rail against the sleeper. Particularly suitable for the inserts is a wood having hardness and Fracture strength improved by impregnating it with plastics material.
The inserts~ as well as the grooves made for these inserts in a sleeper may be shaped in such a manner as to prevent the inserts from falling out of the sleeper. In such a case the inserts as well as the grooves receiving these inserts may have the shape of a prism with a pentagonal base.
The rail or the plate rests against the horizontal face of the insert. Two faces opposite to this face transmit to the sleeper the force of the rail pressing against the sleeper, while the two adjacent faces are thrust faces preventing the inserts from falling out of the sleeper.
The inserts may be a little smaller in cross-section relative to the cross-section of the grooves cut in the sleeper. A layer of a binding material or an elastic spacer is sandwiched in such a case, between the insert and the bottom of the groove. This layer constitutes a spacer which may be of rubber, enabling an absolutely uniform transmission of forces from the insert to the wood of the sleeper, said spacer being at the same time a sealing layer between the insert and the sleeper. The inserts used in sleep-ers according to the invention can also fulfill an additional ~unction besides the heretofore described transmission and redirection of forces acting on the sleeper. They can be used as elements preventing the sleepers from cracking along the grain (it is generally known that sleepers tend to crack lengthwise in service under the influence of weather and under mechanical loads). This can be achieved when the contacting faces of each insert and the associated groove in the sleeper are curvilinear in contour, thus causing the insert to operate in the sleeper in a way similar to a clamp stapling the sleeper laterally.
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:
; .
- .-- 1~)4;~ Z
Figure 1 illustrates a portion of a sleeper in accordance with a first embodiment of the invention, in a vertical section along the centre line of the sleeper, with a rail supportcd thereon, and including rail-mounting elements;
Figure 2 is a plan view illustrating the same portion of the sleep-er as Figure 1 but omitting the rail and rail-mounting elements, Figures 3 to 5 are s~ctional views similar to Figure 1, but illustrating sleepers in accordance with second, third and fourth embodiments of the invention, respectively;
Figure 6 is a sectional view similar to Figure 1 but illustrating a modification of the first embodiment of the sleeper in that rubber separat-ors are included;
Figure 7 illustrates part of a sleeper in accordance with a fifth embodiment of the invention equipped with inserts preventing cracking of the sleeper in the lengthwise direction, the view being a vertical section along the line A-A in Figure 8;
Figure 8 is a plan view of the sleeper shown in Figure 7;
Figure 9 is a vertical section through the sleeper shown in Figures 7 and 8, along the line B-B in Figure 8;
Figure 10 is a plan view of a part of a sleeper in accordance with a sixth embodiment of the invention, also equipped with inserts preventing cracking of the sleeper in the lengthwise direction; and Figure 11 illustrates the sleeper shown in Figure 10 in a vertical section along the line C-C in Figure 10.
Referring firstly to Figures 1 and 2, the sleeper in accordance with the first embodiment of the invention is denoted by the reference numeral 1 and is provided with two inserts 2 positioned under each rail when the rails are mounted in position, said inserts having in cross-section the form of wedges rounded at their thin edges. Each insert 2 is fitted into a groove milled in the sleeper 1. The cross-sections of the grooves match the ~:
shapes of the inserts 2. A gap is left between the bottom of each groove and the bottom or rounded portion of the pertaining insert. The inserts 2 3. _ 4_ , 1~)4;~4V;:
extend over the whole width of the sleeper 1. ~ conventional steel sole plate 3 rests against each pair of inserts 2 and is fixed to the sleeper 1 by means of four screws 4. A rail 6 is fixed to the plate 3 by means of clamps 5.
The force F of plate 3 pressing against each insert 2 is resolved, in accordance with the principle of action of a wedge, into two force compon-ents Fl and F2, with which the side faces of inser~ 2 act on the sleeper 1.
The forces Fl and F2 are directed diagonally relative to the grain of the sleeper, and horizontal components Fll and F21 of the said forces, which horizontal components are parallel to the grain of wood, are greater than the vertical components F12 and F22, which are perpendicular to the grain. The force P is thus resolved first of all along the grain, and only a minor component thereof acts laterally to the grain. Irrespective of this favourable redirection of forces, the inserts 2 give rise also to another desired effect. The area of contact between inserts 2 and sleeper 1 is greater than the free area of plate 3. In this way the pressures per unit area over the sleeper are lower when the inserts 2 are used, than would be the case if the inserts 2 were not used and the plate 3 presses directly against the sleeper.
Referring now to Figure 3, in the sleeper according to the second embodiment there is but a single insert 2 under each rail 6, said insert consis~ing of two parts. In the sleeper of the third embodiment of the invention, shown in Figure 4~ there are six inserts 2 under the plate 3 of each individual rail 6. In this latter case, the two inserts 2a and 2b nearer each flank of the plate 3 result in an improved grip of the screws 4 in the wood, because thP wood is compressed near the said screws. In the fourth embodiment illustrated in Figure 5, both the inserts and the grooves receiving the said inserts same have a different cross-sectional shape in order to prevent the inserts 2 from falling out of the sleeper. Each insert has two oblique walls 7 near its top face, said walls resting against the faces of grooves suitably milled in sleeper 1. The inserts 2 are fitted into the sleeper by pushing them in along the centre lines of the grooves.
.. .. .
. :: ; . . ~ .. ..
~4~Z4~2 In the modification of the first embodiment, illustrated in Figurc 6, a layer of an elastic material such as rubber is sandwiched between the face of each of the grooves in the sleeper and the face of the associated insert 2, in order to absorb concussion, to serve as a seal or as an electric insulating layer.
In the fifth and sixth embodiments of the invention, illustrated in Figures 7 to 11, the inserts 2 redirect the compressive forces as hereinbefore described above, and also prevent lengthwise cracking of the sleeper. In the fifth embodiment illustrated in Figures 7 to 9, the flanks and the thin edge of each wedge-shaped insert are rounded in the longitudinal direction, i.e. transversely of the sleeper, the cross-sectional dimensions of the wedge-shaped insert being greater at its ends than at its middle portion, both widthwise and depthwise. The grooves are of course complementarily shaped and, in this way, as is illustrated in Figures 8 and 9, each insert 2 "saddles" and closes the sleeper laterally.
In the sixth embodiment illustrated in Figures 10 and 11, the flanks and the thin edges of the inserts 2 are corrugated or undulating and the grooves are complementarily shaped. The resulting protuberances and depres-sions extending in the upwards direction on and in the two flanks of each insert may be arranged so that each protuberance in one flank is opposite ~o a depression in the other (the left-hand insert in Figure 10) or so that each protuberance or depression in one flank is opposite to a protuberance or depression in the other (the right-hand insert in Figure 10). These pro-tuberances and depressions result in the sleeper 1 being clasped laterally, thus preventing lengthwise cracking thereof.
Manifestly, the invention is not restricted exclusively to the embodiments thereof hereinbefore described. ~;
Sleepers according to the invention may also be used where wooden elements have hitherto been used for the transmission of high loads directed laterally relative to the wood grain, for example as in wooden elements designed for various heavy machinery or tools, or in tracks for heavy machines. ;~
: .
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A wooden sleeper particularly suitable for use in railway tracks or tracks for heavy machinery, said sleeper being provided in each rail-mounting zone thereof with at least one insert of material harder than the wood of the sleeper and improving the compressive strength of the sleeper in places where anticipated loads may exceed the strength of the wood, the or each insert being wedge-shaped in cross-section, with the thin edge thereof being directed downwardly, and being glued in a complementarily-shaped groove or recess in the rail-bearing surface of the unrestrained sleeper in a zone where high loads are to be anticipated, and each groove or recess and insert running transversely at right angles to the longidutinal centre line of the sleeper.
2. A wooden sleeper as claimed in claim 1, wherein the inserts are of wood impregnated with plastics material.
3. A wooden sleeper as claimed in claim 1, wherein the inserts are of hard wood.
4. A wooden sleeper as claimed in claim 1, wherein the inserts are of plastics material.
5. A wooden sleeper as claimed in claim 1, wherein the thin edge of the or each wedge-like insert is rounded.
6. A wooden sleeper as claimed in claim 1, wherein the grooves or recesses and the inserts have cross-sectional configurations of such shape as to prevent falling of the inserts out of the sleeper.
7. A wooden sleeper as claimed in claim 1, 2 or 3, wherein a layer of elastic material is sandwiched between the face of each groove or recess and the face of the insert fitted therein.
8. A wooden sleeper as claimed in claim 1, wherein the insert or at least one of the inserts and the respective groove in each rail-mounting zone of the sleeper include end portions which are of greater cross-section, both width-wise and depth-wise than the remainder, in order to protect the sleeper against longitudinal cracking.
9. A wooden sleeper as claimed in claim 8, wherein the flanks of inserts and associated grooves are longitudinally corrugated or undulating.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PL1974176555A PL100999B1 (en) | 1974-12-17 | 1974-12-17 | WOODEN PRIMING ESPECIALLY FOR RAILWAY TRACKS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1042402A true CA1042402A (en) | 1978-11-14 |
Family
ID=19970143
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA241,851A Expired CA1042402A (en) | 1974-12-17 | 1975-12-16 | Wooden sleeper, particularly suitable for railway track |
Country Status (8)
| Country | Link |
|---|---|
| CA (1) | CA1042402A (en) |
| DE (1) | DE2554625C3 (en) |
| FI (1) | FI60584C (en) |
| GB (1) | GB1494379A (en) |
| NO (1) | NO754285L (en) |
| PL (1) | PL100999B1 (en) |
| SE (1) | SE418874B (en) |
| SU (1) | SU805956A3 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10711406B2 (en) | 2018-01-10 | 2020-07-14 | Voestalpine Nortrak Inc. | Keyway tie |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3529679A1 (en) * | 1985-08-20 | 1987-02-26 | Martini Anita | Rail fastening |
| DE3709034A1 (en) * | 1986-10-08 | 1988-04-21 | Siegfried Keusch | DEVICE FOR FASTENING A RAIL ON A SILL |
| DE4212679B4 (en) * | 1992-04-15 | 2005-02-24 | Bwg Gmbh & Co. Kg | Arrangement of a rail |
-
1974
- 1974-12-17 PL PL1974176555A patent/PL100999B1/en unknown
-
1975
- 1975-12-04 DE DE2554625A patent/DE2554625C3/en not_active Expired
- 1975-12-08 SU SU752196557A patent/SU805956A3/en active
- 1975-12-09 GB GB50343/75A patent/GB1494379A/en not_active Expired
- 1975-12-16 SE SE7514208A patent/SE418874B/en unknown
- 1975-12-16 CA CA241,851A patent/CA1042402A/en not_active Expired
- 1975-12-16 FI FI753545A patent/FI60584C/en not_active IP Right Cessation
- 1975-12-16 NO NO754285A patent/NO754285L/no unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10711406B2 (en) | 2018-01-10 | 2020-07-14 | Voestalpine Nortrak Inc. | Keyway tie |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2554625A1 (en) | 1976-06-24 |
| GB1494379A (en) | 1977-12-07 |
| SU805956A3 (en) | 1981-02-15 |
| PL100999B1 (en) | 1978-11-30 |
| SE7514208L (en) | 1976-06-18 |
| DE2554625C3 (en) | 1979-03-22 |
| NO754285L (en) | 1976-06-18 |
| FI60584B (en) | 1981-10-30 |
| FI753545A7 (en) | 1976-06-18 |
| FI60584C (en) | 1982-02-10 |
| DE2554625B2 (en) | 1978-07-20 |
| SE418874B (en) | 1981-06-29 |
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