Steel rail web polishing device

Abstract

The utility model discloses a steel rail web polishing device, which relates to the technical field of metallurgy and comprises a first support frame, a driving motor, a first rotating shaft, a first grinding wheel, a second rotating shaft, a second grinding wheel, a plurality of first distance adjusting devices, a plurality of second distance adjusting devices, a second support frame and a plurality of guide wheels, the top of the first rotating shaft is in transmission connection with a driving motor; the first grinding wheel is connected with the first rotating shaft; the top of the second rotating shaft is in transmission connection with a driving motor; the second grinding wheel is connected with the second rotating shaft, and the first grinding wheel and the second grinding wheel are used for grinding the rail waist of the steel rail; the first distance adjusting device can drive the first rotating shaft to get close to or away from the second rotating shaft; the second distance adjusting device can drive the second rotating shaft to get close to or away from the first rotating shaft; the multiple guide wheels are rotationally connected to the second supporting frame and used for making contact with the treads of the steel rails, the structure is simple, use is convenient, and the working efficiency is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of metallurgy, in particular to a rail waist grinding device. Background Art

[0002] As we all know, rails are long hot-rolled products with extremely complex cross-sections. The rail manufacturer's trademark and rail furnace number are usually printed on the rail waist to trace the rail production process. Rails are delivered in fixed lengths, and the common fixed lengths are 100 meters and 25 meters. When delivering 25 meters, the rails need to be cut into four sections. The rail trademark or furnace number will appear at the end of the 25-meter fixed-length rail. During rail welding or punching and connection, in order to ensure the flatness of the rail waist, the rail manufacturer needs to grind the rail waist at the time of delivery to grind off the rail trademark and the corresponding furnace number mark. The grinding depth of the rail after grinding is required to be no more than 0.5mm to prevent the cross-sectional width of the rail waist from being reduced due to the grinding of the rail waist. However, the waist of the rail is a straight line connected by curves. During the grinding process, the depth of the rail mark is inconsistent on the waist of the rail. When the part of the mark on the waist of the rail is ground flat, it is easy to form a grinding mark larger than 0.5mm in the middle of the waist of the rail, which is not allowed in the rail grinding. Utility Model Content

[0003] The utility model aims to provide a rail waist grinding device to solve the problems existing in the above-mentioned prior art, with simple structure, convenient use and effective improvement of work efficiency.

[0004] To achieve the above purpose, the utility model provides the following solutions:

[0005] The utility model provides a rail waist grinding device, comprising: a first support frame, a driving motor, a first rotating shaft, a first grinding wheel, a second rotating shaft, a second grinding wheel, a plurality of first distance adjustment devices, a plurality of second distance adjustment devices, a second support frame and a plurality of guide wheels, wherein the driving motor is fixedly connected to the top of the first supporting frame, and the output shaft of the driving motor passes through the first supporting frame; the first rotating shaft is rotatably connected to the first supporting frame, and the top of the first rotating shaft is transmission-connected to the driving motor; the first grinding wheel is fixedly connected to the bottom of the first rotating shaft; the second rotating shaft is rotatably connected to the first supporting frame, and the top of the second rotating shaft is transmission-connected to the driving motor; the second grinding wheel is fixedly connected to the bottom of the second rotating shaft, and the first grinding wheel and the second The grinding wheel is used to be arranged on both sides of the rail to grind the waist of the rail; the first distance adjustment device is fixedly connected to the first side of the first support frame, and the other side is used to be rotatably connected to the first rotating axis, and the extension or shortening of the first distance adjustment device can drive the first rotating axis to approach or move away from the second rotating axis; one end of each second distance adjustment device is fixedly connected to the second side of the first support frame, and the other side is used to be rotatably connected to the second rotating axis, and the extension or shortening of the second distance adjustment device can drive the second rotating axis to approach or move away from the first rotating axis; the second support frame is used to be fixedly connected to the first support frame; the plurality of guide wheels are used to be rotatably connected to the second support frame, and each guide wheel is used to contact the tread of the rail.

[0006] Preferably, it also includes a first belt and a second belt, the first pulley and the second pulley are arranged on the output shaft of the driving motor, the third pulley is arranged on the top of the first rotating shaft, and the fourth pulley is arranged on the top of the second rotating shaft, the first belt is used to link the first pulley and the third pulley, and the second belt is used to link the second pulley and the third pulley.

[0007] Preferably, the first distance adjustment device includes a first screw, a first bidirectional threaded sleeve, a second screw and a first rotating shaft, one end of the first screw is used for fixed connection with the first support frame, and the other end is used for threaded connection with the first bidirectional threaded sleeve, one end of the second screw is used for fixed connection with the first rotating shaft, and the other end is used for threaded connection with the first bidirectional threaded sleeve, and the rotation directions of the first screw and the second screw are opposite, and the first rotating shaft is used to be sleeved on the outside of the first rotating shaft and be rotatably connected with the first rotating shaft.

[0008] Preferably, the second distance adjustment device includes a third screw, a second bidirectional threaded sleeve, a fourth screw and a second rotating shaft, one end of the third screw is used for fixed connection with the first support frame, and the other end is used for threaded connection with the second bidirectional threaded sleeve, one end of the fourth screw is used for fixed connection with the second rotating shaft, and the other end is used for threaded connection with the second bidirectional threaded sleeve, and the rotation directions of the third screw and the fourth screw are opposite, and the second rotating shaft is used to be sleeved on the outside of the second rotating shaft and be rotatably connected to the second rotating shaft.

[0009] Preferably, the guide wheel includes an arc contact surface and two wing plates, the two wing plates are fixedly connected to the two ends of the arc contact surface, the distance between the two wing plates is the same as the distance between the two vertical side surfaces at the top of the rail, and the arc contact surface is completely consistent with the rail tread.

[0010] Preferably, the bottom edge of the wing plate in contact with the vertical side surface is an arc transition structure.

[0011] Preferably, it also includes a first nut and a second nut, a first threaded section is provided at the bottom of the first rotating shaft, the first grinding wheel is sleeved on the first threaded section, and the first nut is threadedly connected to the first threaded section and is provided above the first grinding wheel, and the second nut is threadedly connected to the first threaded section and is provided below the first grinding wheel.

[0012] Preferably, it also includes a third nut and a fourth nut, a second thread segment is provided at the bottom of the second rotating shaft, the second grinding wheel is sleeved on the second thread segment, and the third nut is threadedly connected to the second thread segment and is provided above the second grinding wheel, and the fourth nut is threadedly connected to the second thread segment and is provided below the second grinding wheel.

[0013] Preferably, it further comprises a handle, wherein the handle is fixedly connected to a side of the second support frame away from the first support frame.

[0014] Preferably, the line of the first grinding wheel used for contacting the waist of the rail is a circular arc line, and the circular arc line is consistent with the curvature of the waist of the rail.

[0015] Compared with the prior art, the utility model has achieved the following technical effects:

[0016] The utility model provides a rail waist grinding device. When grinding a trademark, the first grinding wheel and the second grinding wheel are parallel and flush with the trademark to be polished. The first distance adjustment device is used to adjust the spacing of the rail waist of the first grinding wheel rail, and the second distance adjustment device is used to adjust the spacing of the rail waist of the second grinding wheel rail, that is, the grinding amount is adjusted. The drive motor is started, and the first rotating shaft and the second rotating shaft of the motor rotate to drive the first grinding wheel and the second grinding wheel to perform grinding. Pre-grinding is performed first, and the distance adjustment device of the grinding wheel shaft 12 is adjusted to control the grinding amount. During the grinding process, both hands hold the second support frame tightly to maintain balance during the grinding process. The trademark side is hot-stamped, which protrudes about 2mm from the rail waist surface, and the furnace number is printed at a depth of about 1mm below the rail waist surface. According to the trademark or furnace number to be polished, the first distance adjustment device and the second distance adjustment device on both sides are adjusted to control the grinding amount. After the grinding amount is controlled, grinding is usually completed in one pass, and there is no need for repeated grinding. However, the grinding amount of each pass should be appropriately adjusted according to the hardness of the rail. When the rail is harder (the hardness of the hot-rolled state is low, and the hardness of the heat-treated state is high), it can be adjusted to be completed in one pass, or it can be ground in multiple passes. The device can be flexibly applied to the grinding of the waist of hot-rolled or heat-treated rails. It is flexible and easy to use, and has strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a front view of the rail waist grinding device provided by the utility model;

[0019] Figure 2 A side view of the rail waist grinding device provided by the utility model;

[0020] Figure 3 This is a schematic structural diagram of a first distance adjustment device in a rail waist grinding device provided by the utility model;

[0021] In the figure: 1. first support frame; 2. drive motor; 3. first rotating shaft; 4. first grinding wheel; 5. second rotating shaft; 6. second grinding wheel; 7. first distance adjusting device; 8. second distance adjusting device; 9. second support frame; 10. guide wheel; 11. first belt; 12. second belt; 13. first screw; 14. first bidirectional threaded sleeve; 15. second screw; 16. arc contact surface; 17. wing plate; 18. handle; 19. rail. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] The utility model aims to provide a rail waist grinding device to solve the problems existing in the above-mentioned prior art, with simple structure, convenient use and effective improvement of work efficiency.

[0024] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0025] The utility model provides a rail waist grinding device for a steel rail 19, such as Figures 1 to 3As shown, it includes: a first support frame 1, a drive motor 2, a first rotating shaft 3, a first grinding wheel 4, a second rotating shaft 5, a second grinding wheel 6, a plurality of first distance adjustment devices 7, a plurality of second distance adjustment devices 8, a second support frame 9 and a plurality of guide wheels 10, the drive motor 2 is fixedly connected to the top of the first support frame 1, and the output shaft of the drive motor 2 passes through the first support frame 1; the first rotating shaft 3 is rotatably connected to the first support frame 1, and the top of the first rotating shaft 3 is transmission-connected to the drive motor 2; the first grinding wheel 4 is fixedly connected to the bottom of the first rotating shaft 3; the second rotating shaft 5 is rotatably connected to the first support frame 1, and the top of the second rotating shaft 5 is transmission-connected to the drive motor 2; the second grinding wheel 6 is fixedly connected to the bottom of the second rotating shaft 5, the first grinding wheel 4 and the second grinding wheel 6 are used to be arranged on both sides of the rail 19 to grind the waist of the rail 19; the first distance adjustment device is fixedly connected to a first side of the first support frame 1, and the other side is used to be rotatably connected to the first rotating shaft 3, and the extension or shortening of the first distance adjustment device 7 can bring The first rotating shaft 3 is moved closer to or away from the second rotating shaft 5; one end of each second distance adjusting device 8 is fixedly connected to the second side of the first support frame 1, and the other end is used to be rotatably connected to the second rotating shaft 5, and the extension or shortening of the second distance adjusting device 8 can drive the second rotating shaft 5 to move closer to or away from the first rotating shaft 3; the second support frame is used to be fixedly connected to the first support frame 1; a plurality of guide wheels 10 are used to be rotatably connected to the second support frame 9, and each guide wheel 10 is used to contact the tread of the rail 19, and the grinding trademark is parallel and flush with the first grinding wheel 4 and the second grinding wheel 6 to be parallel and flush with the trademark to be ground, and the first distance adjusting device 7 is used to adjust the spacing of the first grinding wheel 4 and the rail 19 of the rail waist, and the second distance adjusting device 8 is used to adjust the spacing of the second grinding wheel 6 and the rail 19 of the rail waist, that is, the grinding amount is adjusted, and the driving motor 2 is started, and the first rotating shaft 3 and the second rotating shaft 5 of the motor rotate, driving the first grinding wheel 4 and the second grinding wheel 6 to grind, and pre-grinding is performed first, and the grinding wheel shaft 12 distance adjusting device is adjusted to control the grinding amount. During the grinding process, hold the second support frame 9 tightly with both hands to maintain balance during the grinding process. The trademark side is hot-stamped, which protrudes about 2mm from the rail waist surface, and the furnace number is printed at a depth of about 1mm below the rail waist surface. According to the trademark or furnace number being ground, adjust the first distance adjustment device 7 and the second distance adjustment device 8 on both sides to control the grinding amount. After controlling the grinding amount, it is usually completed in one time, and there is no need for repeated reciprocating grinding. However, the grinding amount of each pass should be appropriately adjusted according to the hardness of the rail 19. When the rail 19 is harder (the hardness in the hot-rolled state is low and the hardness in the heat-treated state is high), it can be adjusted to be completed in one time, or it can be ground in multiple passes. The device can be flexibly used for grinding the waist of the hot-rolled or heat-treated rail 19. It is flexible to operate and easy to use, and has strong practicality.

[0026] In a preferred embodiment, the rail waist grinding device of the rail 19 also includes a first belt 11 and a second belt 12, the first belt 11 wheel and the second belt 12 wheel are arranged on the output shaft of the driving motor 2, the third belt pulley is arranged on the top of the first rotating shaft 3, and the fourth belt pulley is arranged on the top of the second rotating shaft 5. The first belt 11 is used to connect the first belt 11 wheel and the third belt pulley, and the second belt 12 is used to connect the second belt 12 wheel and the third belt pulley. The distance adjustment between the first rotating shaft 3 and the second rotating shaft 5 and the output shaft of the driving motor 2 is slight. The height of the protruding part to be polished is 2mm, the maximum negative deviation is 0.5mm, and the maximum polishing depth is 2.5mm. The transmission is performed by setting the first belt 11 and the second belt 12. The belt transmission can adapt to the slight adjustment of the first rotating shaft 3 and the second rotating shaft 5. After adjusting the distance, the loose state of the belt can be accepted and can continue to be transmitted. If the adjustment distance increases after the sanding contour is repaired, causing the belt to loosen, a belt tensioning adjustment wheel can be added according to the belt state.

[0027] In a preferred embodiment, the first distance adjustment device 7 includes a first screw 13, a first bidirectional threaded sleeve 14, a second screw 15 and a first rotating shaft. One end of the first screw 13 is used to be fixedly connected to the first support frame 1, and the other end is used to be threadedly connected to the first bidirectional threaded sleeve. One end of the second screw 15 is used to be fixedly connected to the first rotating shaft, and the other end is used to be threadedly connected to the first bidirectional threaded sleeve 14. The rotation directions of the first screw 13 and the second screw 15 are opposite. The first rotating shaft is used to be sleeved on the outside of the first rotating shaft 3 and is rotatably connected to the first rotating shaft 3. It has a simple structure and is easy to use. The first screw 13 and the second screw 15 can be brought closer or farther away by rotating the first bidirectional threaded sleeve 14.

[0028] In a preferred embodiment, the second distance adjusting device 8 includes a third screw, a second bidirectional threaded sleeve, a fourth screw and a second rotating shaft, one end of the third screw is used to be fixedly connected to the first support frame 1, and the other end is used to be threadedly connected to the second bidirectional threaded sleeve, one end of the fourth screw is used to be fixedly connected to the second rotating shaft, and the other end is used to be threadedly connected to the second bidirectional threaded sleeve, and the rotation directions of the third screw and the fourth screw are opposite, and the second rotating shaft is used to be sleeved on the outside of the second rotating shaft 5 and rotatably connected to the second rotating shaft 5. It has a simple structure and is easy to use. The first screw 13 and the second screw 15 can be brought closer or farther away by rotating the first bidirectional threaded sleeve 14.

[0029] In a preferred embodiment, the guide wheel 10 includes an arc contact surface 16 and two wing plates 17. The two wing plates 17 are fixedly connected to the two ends of the arc contact surface 16. The distance between the two wing plates 17 is the same as the distance between the two vertical side surfaces at the top of the rail 19. The arc contact surface is completely consistent with the tread of the rail 19. The arc contact surface is composed of three arcs, which are R200mm, R70mm and R16mm respectively. Figure 2 At the same time, the guide wheel has two wing edges for limiting the width of the rail head of the rail 19.

[0030] In a preferred embodiment, the bottom edge of the wing plate 17 that contacts the vertical side surface is an arc transition structure to prevent the side surface of the rail 19 from being scratched during rolling.

[0031] In a preferred embodiment, it also includes a first nut and a second nut, a first thread segment is provided at the bottom of the first rotating shaft 3, the first grinding wheel 4 is sleeved on the first thread segment, and the first nut is threadedly connected to the first thread segment and is provided above the first grinding wheel 4, and the second nut is threadedly connected to the first thread segment and is provided below the first grinding wheel 4.

[0032] In a preferred embodiment, a third nut and a fourth nut are also included, a second thread segment is provided at the bottom of the second rotating shaft 5, the second grinding wheel 6 is sleeved on the second thread segment, and the third nut is threadedly connected to the second thread segment and is provided above the second grinding wheel 6, and the fourth nut is threadedly connected to the second thread segment and is provided below the second grinding wheel 6.

[0033] In a preferred embodiment, a handle 18 is further included. The handle 18 is fixedly connected to a side of the second support frame 9 away from the first support frame 1 .

[0034] In a preferred embodiment, the first grinding wheel 4 and the second grinding wheel 6 have the same structure, and the line of the first grinding wheel 4 used to contact the waist of the rail 19 is an arc line, which matches the curvature of the waist of the rail 19. The specific grinding wheel surface is an arc of R400, not a straight line, and the size is determined according to the curvature of the waist of the rail 19. This is the key to ensuring uniform grinding of the waist of the rail 19 during the grinding process and preventing local grinding from exceeding the standard. The grinding of the worn sand contour should also be performed according to the radius of R400mm.

[0035] During use, first assemble the device, such as Figure 2As shown. Adjust the distance between the grinding wheel and the rail waist on the rail 19 to control the grinding distance between the grinding wheel and the rail waist, that is, adjust the grinding amount. Adjust the position of the grinding wheel on the rail waist of the rail 19 through the grinding wheel locking nut at the end of the grinding wheel shaft, usually parallel and flush with the grinding trademark. Start the drive motor 2, the motor drives the grinding wheel shaft to rotate, and the grinding wheel shaft drives the grinding wheel for grinding. Pre-grinding is performed first, and the distance adjustment device of the grinding wheel shaft 12 is adjusted to control the grinding amount. During the grinding process, both hands must hold the bracket handle 18 tightly to maintain balance during the grinding process. The trademark side is hot-stamped, which protrudes about 2mm from the rail waist surface, and the furnace number printing number is about 1mm below the surface of the rail waist. According to the grinding trademark or furnace number, adjust the grinding wheel distance adjustment devices on both sides to control the grinding amount. After the adjustment device controls the grinding amount, grinding is usually completed in one time, and there is no need for repeated grinding. However, the grinding amount of each pass should be appropriately adjusted according to the hardness of the rail 19. When the rail 19 is harder (high hardness in hot-rolled state and low hardness in heat-treated state), it can be adjusted to be completed in one time, or it can be ground in multiple passes.

[0036] It can be seen from the examples that the device can be flexibly applied to the grinding of the waist of the hot-rolled or heat-treated rail 19, is flexible to operate, easy to use, and has strong practicality.

[0037] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A rail waist grinding device, characterized in that: include: The first support frame, A driving motor, wherein the driving motor is fixedly connected to the top of the first supporting frame, and an output shaft of the driving motor passes through the first supporting frame; A first rotating shaft, wherein the first rotating shaft is rotatably connected to the first supporting frame, and the top of the first rotating shaft is transmission-connected to the driving motor; A first grinding wheel, wherein the first grinding wheel is fixedly connected to the bottom of the first rotating shaft; A second rotating shaft, the second rotating shaft is rotatably connected to the first supporting frame, and the top of the second rotating shaft is transmission-connected to the driving motor; a second grinding wheel, wherein the second grinding wheel is fixedly connected to the bottom of the second rotating shaft, and the first grinding wheel and the second grinding wheel are used to be arranged on both sides of the rail to grind the waist of the rail; A plurality of first distance adjustment devices, wherein the first distance adjustment devices are fixedly connected to a first side of the first support frame, and the other side is used for rotationally connecting to the first rotating shaft, and the extension or contraction of the first distance adjustment devices can drive the first rotating shaft to approach or move away from the second rotating shaft; A plurality of second distance adjustment devices, one end of each of the second distance adjustment devices is fixedly connected to the second side of the first support frame, and the other end is used to be rotatably connected to the second rotating shaft, and the extension or shortening of the second distance adjustment device can drive the second rotating shaft to move closer to or farther from the first rotating shaft; A second support frame, the second support frame is used to be fixedly connected to the first support frame; as well as A plurality of guide wheels are provided, wherein the plurality of guide wheels are used for rotationally connecting to the second support frame, and each guide wheel is used for contacting the tread of the rail.

2. The rail waist grinding device according to claim 1, characterized in that: It also includes a first belt and a second belt, the first pulley and the second pulley are arranged on the output shaft of the driving motor, the third pulley is arranged on the top of the first rotating shaft, and the fourth pulley is arranged on the top of the second rotating shaft, the first belt is used to link the first pulley and the third pulley, and the second belt is used to link the second pulley and the third pulley.

3. The rail waist grinding device according to claim 2, characterized in that: The first distance adjustment device includes a first screw, a first bidirectional threaded sleeve, a second screw and a first rotating shaft, one end of the first screw is used to be fixedly connected to the first support frame, and the other end is used to be threadedly connected to the first bidirectional threaded sleeve, one end of the second screw is used to be fixedly connected to the first rotating shaft, and the other end is used to be threadedly connected to the first bidirectional threaded sleeve, and the first screw and the second screw have opposite rotation directions, and the first rotating shaft is used to be sleeved on the outside of the first rotating shaft and be rotatably connected to the first rotating shaft.

4. The rail waist grinding device according to claim 3, characterized in that: The second distance adjustment device includes a third screw, a second bidirectional threaded sleeve, a fourth screw and a second rotating shaft, one end of the third screw is used to be fixedly connected to the first support frame, and the other end is used to be threadedly connected to the second bidirectional threaded sleeve, one end of the fourth screw is used to be fixedly connected to the second rotating shaft, and the other end is used to be threadedly connected to the second bidirectional threaded sleeve, and the rotation directions of the third screw and the fourth screw are opposite, and the second rotating shaft is used to be sleeved on the outside of the second rotating shaft and be rotatably connected to the second rotating shaft.

5. The rail waist grinding device according to claim 1, characterized in that: The guide wheel includes an arc contact surface and two wing plates, the two wing plates are fixedly connected to the two ends of the arc contact surface, the distance between the two wing plates is the same as the distance between the two vertical side surfaces of the top of the rail, and the arc contact surface is completely consistent with the rail tread.

6. The rail waist grinding device according to claim 5, characterized in that: The bottom edge of the wing plate for contacting the vertical side surface is an arc transition structure.

7. The rail waist grinding device according to claim 1, characterized in that: It also includes a first nut and a second nut. A first threaded section is provided at the bottom of the first rotating shaft. The first grinding wheel is sleeved on the first threaded section. The first nut is threadedly connected to the first threaded section and is provided above the first grinding wheel. The second nut is threadedly connected to the first threaded section and is provided below the first grinding wheel.

8. The rail waist grinding device according to claim 7, characterized in that: It also includes a third nut and a fourth nut. A second threaded segment is provided at the bottom of the second rotating shaft. The second grinding wheel is sleeved on the second threaded segment. The third nut is threadedly connected to the second threaded segment and is provided above the second grinding wheel. The fourth nut is threadedly connected to the second threaded segment and is provided below the second grinding wheel.

9. The rail waist grinding device according to claim 1, characterized in that: It also includes a handle, which is fixedly connected to a side of the second support frame away from the first support frame.

10. The rail waist grinding device according to claim 1, characterized in that: The line of the first grinding wheel used for contacting the waist of the rail is a circular arc line, and the circular arc line is consistent with the curvature of the waist of the rail.

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