RAIL GRINDING MACHINE AND METHOD FOR GRINDING A RAIL OF A TRACK

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. § 119, of German Patent Application DE 102024209 981.3, filed October 15, 2024; the prior application is herewith incorporated by reference in its entirety.

FIELD AND BACKGROUND OF THE INVENTION

The contents of German patent application DE 102024 209 981.3 is incorporated by reference.

The invention relates to a rail grinding machine and a method for grinding a rail of a track. The rail grinding machine can in particular be manually moved and tilted by means of a handle. In particular, the rail grinding machine is designed for manual moving and manual tilting on exactly one rail.

Published, non-prosecuted German patent application DE 1274610 A (corresponding to U.S. patent No. 3,427,758 A) discloses a rail grinding machine for grinding a rail of a track. The rail grinding machine can be moved manually on exactly one rail. The rail grinding machine comprises a chassis frame, on which rollers are arranged. A machine framework is mounted on the chassis frame between the rollers. A frame part is mounted on the machine framework, which can be adjusted in height relative to the machine framework and the chassis frame by means of a spindle drive. A grinding device, which comprises a drive motor, is attached to the frame part. To grind the rail, a grinding wheel can be driven in rotation about an axis of rotation by means of the drive motor. To profile the rail, the machine framework with the grinding device arranged thereon is pivoted relative to the chassis frame.

SUMMARY OF THE INVENTION

The object of the invention is to create a rail grinding machine for grinding a rail of a track which has a simple design and is very convenient to use.

With the foregoing and other objects in view there is provided, in accordance with the invention, a rail grinding machine for grinding a rail of a track, by manually moving and manually tilting on exactly one said rail. The rail grinding machine includes a machine frame and two rail guide units for guiding the rail grinding machine on exactly one said rail. The rail guide units are spaced apart from one another in a longitudinal direction. The rail guide units are disposed on the machine frame. The rail grinding machine further has a grinding tool, a grinding unit having a drive motor and a tool holder for driving the grinding tool in rotation about an axis of rotation, and a height adjustment device for adjusting a height of the grinding unit relative to the machine frame and has a guide. The guide of the height adjustment device defines a guide plane, and the axis of rotation is spaced apart from the guide plane. A handle is use for manually moving the grinding unit.

This object is achieved by a rail grinding machine having the features of the independent claim. The rail grinding machine can be moved in particular on a rail and/or tilted on a rail by means of the handle. This makes it possible in particular to profile the rail using the grinding tool by means of head grinding and/or side grinding. The height adjustment device is arranged on the machine frame. The grinding unit is arranged on the height adjustment device for height adjustment relative to the machine frame. An improved view of the grinding tool and the grinding point on the rail is enabled by virtue of the fact that the axis of rotation of the grinding unit is spaced apart from the guide plane. The axis of rotation is spaced apart from the guide plane in particular in the region of the tool holder, such that during operation of the rail grinding machine, a contact area of a grinding tool held in the tool holder with the rail to be ground is spaced apart from the guide plane. The axis of rotation runs in particular substantially parallel to the guide plane. The axis of rotation is in particular spaced apart from the guide plane in a transverse direction. The transverse direction forms in particular a normal vector to the guide plane.

The guide plane is defined or spanned by the guide. If the guide comprises, for example, two guide units, the guide plane is defined by the central longitudinal axes of the guide units. The guide plane runs in particular parallel to the longitudinal direction. If the rail grinding machine is located on a rail, the guide plane and/or the longitudinal direction runs in particular substantially parallel to the rail or a rail longitudinal direction. The guide is preferably a linear guide. An adjustment direction of the guide runs in particular perpendicular to the longitudinal direction and/or perpendicular to the transverse direction.

The rail grinding machine is configured, in particular, for manual movement and/or manual tilting on exactly one rail of a track. For this purpose, the rail grinding machine comprises exactly two rail guide units for guiding the rail grinding machine on exactly one rail. The exactly two rail guide units are arranged on the machine frame at a distance from one another in the longitudinal direction. The machine frame is thus arranged in the longitudinal direction between the exactly two rail guide units. The longitudinal direction corresponds to a longitudinal rail direction when the rail grinding machine is arranged on the exactly one rail. In particular, the rail grinding machine does not have a rail guide unit for guiding the rail grinding machine on an adjacent additional rail. Because the entire rail grinding machine is tilted for grinding the rail, in particular for profiling the rail, the grinding unit cannot be pivoted relative to the machine frame. The grinding unit can therefore only be displaced linearly relative to the machine frame using the height adjustment device.

The height adjustment device and/or the grinding unit is preferably arranged between the rail guide units in the longitudinal direction. The rail guide units define a longitudinal axis. The guide plane is spaced apart from the longitudinal axis of the rail guide units in the transverse direction. The grinding unit is arranged in particular on a side of the guide plane facing the longitudinal axis. The rail guide units can preferably be pivoted relative to the machine frame about the longitudinal axis. The handle can in particular be pivoted together with the rail guide units about the longitudinal axis. For this purpose, the handle is attached to the rail guide units in a fixed or lockable manner, for example. The handle can be pivoted and locked relative to the rail guide units. The handle is in particular bow-shaped. The handle is laterally spaced apart from the guide plane.

The height adjustment device comprises in particular a spindle drive for adjusting the height of the grinding unit. The spindle drive comprises a spindle axis. The spindle axis can be arranged in the guide plane or spaced apart from the guide plane. The spindle axis is preferably spaced apart from the guide plane in the region of the tool holder. The spindle axis can be spaced apart from the axis of rotation. The spindle axis can be arranged in such a way that the spindle axis lies between the guide plane and the axis of rotation in the region of the tool holder or the axis of rotation lies between the guide plane and the spindle axis in the region of the tool holder or the guide plane lies between the spindle axis and the axis of rotation in the region of the tool holder.

The drive motor is used to drive the tool holder in rotation about the axis of rotation. During operation of the rail grinding machine, a grinding tool is attached in or to the tool holder. The grinding tool can be driven in rotation about the axis of rotation via the tool holder by means of the drive motor. The tool holder is, for example, designed as a flange to which the grinding tool is attached or screwed. In order to grind the rail, the grinding unit and a grinding tool driven in rotation thereby can be moved and/or tilted by means of the handle relative to the rail to be ground. By virtue of the fact that the axis of rotation of the tool holder is spaced apart from the guide plane, the guide does not impair the view of the rail head and the grinding tool, such that an operator has an unrestricted view of the rail head and the grinding tool. The design for spacing the axis of rotation from the guide plane is simple. The rail grinding machine thus has a simple design and is very convenient to use.

The rail grinding machine guarantees a simple design and convenient use. The distance A of the axis of rotation from the guide plane in the transverse direction ensures that an operator has an unrestricted view of the rail head and the grinding tool. The axis of rotation is spaced apart from the guide plane by the distance A in particular in the region of the tool holder. The distance A is substantially constant, but can slightly vary depending on an angular position of the axis of rotation. The distance A of the axis of rotation from the guide plane preferably lies within the claimed range in the entire region of the tool holder. The grinding unit comprises the drive motor and the tool holder, which can be driven in rotation by means of the drive motor. A grinding tool is preferably held or attached in or on the tool holder. The grinding tool is designed as a grinding stone, for example. The drive motor and/or the tool holder and/or the grinding tool preferably do(es) not intersect the guide plane. For this purpose, the distance A is in particular selected accordingly.

The rail grinding machine guarantees a simple design and very convenient use. The machine frame is designed in particular as a machine framework. For this purpose, the machine frame comprises the lower longitudinal member and the upper longitudinal member, as well as a first side member and a second side member. The side members connect the lower longitudinal member and the upper longitudinal member to the machine framework. The guide is attached to the lower longitudinal member and the upper longitudinal member between the side members when viewed in the longitudinal direction. The guide is attached directly and/or indirectly to the lower longitudinal member and/or to the upper longitudinal member. For example, the guide is attached to the upper longitudinal member indirectly via a spindle drive support. The guide is in particular a linear guide. The guide comprises in particular at least two guide units, which are attached to the lower longitudinal member and the upper longitudinal member spaced apart from one another in the longitudinal direction. The guide units are attached directly and/or indirectly. The guide units are therefore arranged between the side members. The lower longitudinal member and/or the upper longitudinal member has a curved shape. The curved shape extends away from the axis of rotation in particular in the transverse direction. The lower longitudinal member preferably extends from the rail guide units in a curved shape away from the axis of rotation. The side members and/or the upper longitudinal member extend(s) accordingly in a curved shape away from the axis of rotation.

In a further embodiment of the rail grinding machine, the at least one guide unit defines the guide plane and the adjustment direction. The adjustment direction runs in particular parallel to the guide plane. The adjustment direction preferably runs perpendicular to the longitudinal direction and/or transverse direction. The at least one guide unit is used in particular as a linear guide. The at least one guide unit is arranged on the machine frame, in particular on a lower longitudinal member and an upper longitudinal member. The at least one guide unit is arranged in particular between two side members, which connect the lower longitudinal member and the upper longitudinal member to one another. The at least one guide unit is attached directly and/or indirectly to the lower longitudinal member and/or to the upper longitudinal member. The guide preferably comprises at least two guide units, which are arranged on the machine frame spaced apart from one another when viewed in the longitudinal direction. The at least two guide units preferably run parallel to one another and define the guide plane and the adjustment direction. For example, the central longitudinal axes of the at least two guide units define the guide plane.

In another embodiment of the rail grinding machine, the guide is used to adjust the height of the grinding unit. For this purpose, the grinding unit is arranged on the guide. The at least one damping element is used for vibration damping and/or vibration decoupling of the handle. Vibrations caused by the grinding and the drive motor and transmitted from the grinding unit to the guide are damped by the at least one damping element and thus at least partially decoupled from the handle. The at least one damping element is arranged between the guide element and the machine frame. The at least one damping element is preferably arranged between the guide element and a lower longitudinal member and/or between the guide element and an upper longitudinal member. The guide element is designed as a guide bar, for example. The guide bar has, for example, a round, oval or polygonal cross-section. The guide bar can be hollow.

In an added embodiment of the rail grinding machine, the respective guide element is arranged between the lower damping element and the upper damping element. The lower damping element and the upper damping element are arranged on the machine frame. The lower damping element is preferably arranged on a lower longitudinal member and the upper damping element on an upper longitudinal member. The lower damping element and/or the upper damping element is attached directly and/or indirectly to the lower longitudinal member and/or to the upper longitudinal member. The lower damping element and the upper damping element enable improved vibration damping and/or vibration decoupling of the handle.

In a further embodiment of the rail grinding machine, thanks to the different spring stiffnesses, the damping elements prevent undesired oscillation of the grinding unit. The at least one guide unit acts in particular as a fixed and floating bearing due to the different spring stiffnesses. The spring stiffness of the lower damping element is preferably greater than the spring stiffness of the upper damping element.

In an additional embodiment of the rail grinding machine, the carriage enables the grinding unit to be easily attached to the guide and/or a simple height adjustment of the grinding unit by means of a spindle drive. The carriage comprises in particular at least one first carriage section to which the grinding unit is attached and one second carriage section to which the spindle drive is attached. The second carriage section runs in particular transversely to the first carriage section. The spindle drive is arranged in particular between the carriage, in particular the second carriage section, and the machine frame, in particular the upper longitudinal member.

In yet another embodiment of the rail grinding machine, the grinding unit and the spindle drive are preferably attached to the carriage. The grinding unit is in particular attached to a first carriage section, whereas the spindle drive is attached to a second carriage section. The second carriage section runs in particular transversely to the first carriage section. The spindle drive is preferably attached between the carriage, in particular the second carriage section, and the machine frame, in particular an upper longitudinal member. An operator has an unrestricted view of the grinding unit, in particular the grinding tool and an associated grinding point thanks to the fact that the grinding unit and the spindle drive are attached to the carriage independently of one another.

In yet a further embodiment of the rail grinding machine, the spindle drive can be spaced apart from the machine frame as a result of the fact that the spindle axis is spaced apart from the guide plane when viewed in the transverse direction. This simplifies the design. The height adjustment device preferably comprises a spindle drive support, which is attached to the machine frame, in particular to the upper longitudinal member, and on which the spindle drive is mounted. A spindle nut of the spindle drive is preferably attached to the spindle drive support, whereas a spindle of the spindle drive is rotatably mounted on the carriage. The spindle drive comprises in particular a handwheel for manual operation. The spindle axis is preferably spaced apart from the axis of rotation in the transverse direction, in particular in the region of the tool holder. This avoids obstructing the view of the rail head and the grinding tool.

In an added embodiment of the rail grinding machine, the spindle drive can be easily attached to the machine frame and a substantially unrestricted view of the rail head and grinding tool is enabled due to the fact that the spindle axis runs between the guide plane and the axis of rotation when viewed in the transverse direction. The spindle axis runs between the guide plane and the axis of rotation in particular in the region of the tool holder. The spindle axis runs in particular parallel to the guide plane and/or the axis of rotation. The spindle axis is preferably at a distance B from the guide plane in the transverse direction, wherein: 1 cm ≤ B < 40 cm, in particular 3 cm ≤ B ≤ 30 cm, in particular 4 cm ≤ B ≤ 20 cm, and in particular 5 cm ≤ B ≤ 10 cm. In particular: B < A. The spindle axis is preferably at a distance B from the guide plane in the region of the tool holder.

In another added embodiment of the rail grinding machine, the machine frame preferably forms a machine framework, which comprises a lower longitudinal member, an upper longitudinal member and side members. The side members connect the lower longitudinal member with the upper longitudinal member. The spindle drive can be attached directly or indirectly to the upper longitudinal member. For example, the spindle drive can be attached to the upper longitudinal member via a spindle drive support. The arrangement of the spindle drive on the upper longitudinal member easily enables the grinding unit to be precisely guided. The height adjustment device preferably comprises a spindle drive support, which is attached to the upper longitudinal member. A spindle nut of the spindle drive is attached to the spindle drive support, whereas a spindle of the spindle drive is rotatably mounted on the carriage. The spindle drive comprises in particular a handwheel for operation.

In another embodiment of the rail grinding machine, the at least one damping element is used in particular for vibration damping and/or vibration decoupling of a handwheel of the spindle drive. The at least one damping element is, for example, arranged between a carriage and the spindle drive and/or between the spindle and the handwheel.

In another additional embodiment of the rail grinding machine, the grinding unit is arranged in an intermediate space between the guide plane and the handle due to the fact that the axis of rotation is arranged on a side of the guide plane facing the handle, in particular in the region of the tool holder. As a result, the rail grinding machine can be easily and conveniently moved and/or tiled by an operator by means of the handle, wherein at the same time simple height adjustment and an unrestricted view of the rail head and grinding point is possible.

In a further embodiment of the rail grinding machine, an in particular unrestricted view of the rail head and grinding point is possible due to the fact that the axis of rotation, in particular in the region of the tool holder, and possibly also the spindle axis are arranged on a side of the guide plane facing away from the handle.

In an added embodiment of the rail grinding machine, the exactly two rail guide units are arranged on the machine frame at a distance from one another in the longitudinal direction. The longitudinal direction runs essentially parallel to a longitudinal direction of the rail to be ground. Because the exactly two rail guide units can be pivoted about the longitudinal axis relative to the machine frame, different processing positions of the exactly two rail guide units can be set. This particularly increases the flexibility and operating comfort when grinding the rail. For example, different rail profiles or rail types and switch areas can be ground. The exactly two rail guide units each comprise, in particular, a base body that is arranged on the machine frame so that it can be pivoted about the longitudinal axis.

In yet another embodiment of the rail grinding machine, the exactly two rail guide units each comprise, in particular, a base body that is arranged on the machine frame so as to be pivotable about a longitudinal axis. The two dish-shaped discs and the guide roller are arranged on the respective base body. The two dish-shaped discs are arranged, in particular, at an angle relative to one another and are rotatable about associated axes. Preferably, the exactly two rail guide units each comprise a guide hook. The guide hook is arranged, in particular, on the base body. The design of the exactly two rail guide units ensures high flexibility and high operating comfort when grinding a rail.

The invention is further based on the object of creating a method for grinding a rail of a track which enables a high level of operating comfort.

The advantages of the method according to the invention correspond to the already described advantages of the rail grinding machine according to the invention. In particular, the method according to the invention can be further developed with any feature described in connection with the rail grinding machine according to the invention. Because the rotational axis of the grinding unit is arranged at a distance from the guide plane, an improved view of the grinding tool and the grinding point on the rail is possible. This enables, in particular, profiling of the rail using the grinding tool by means of a head grinding and/or a side grinding with a high level of operating comfort. The grinding of the rail, in particular, the profiling of the rail, is carried out by manually moving and manually tilting the rail grinding machine on the exactly one rail to be ground using the handle. The height adjustment of the grinding unit relative to the machine frame is carried out by means of the height adjustment device. The grinding tool is rotated around the rotation axis by means of the tool holder and the drive motor.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in a rail grinding machine and a method for grinding a rail of a track, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a first perspective view of a rail grinding machine according to a first exemplary embodiment with a height adjustment device and a grinding unit arranged thereon;

FIG. 2 is a second perspective view of the rail grinding machine;

FIG. 3 is a side view of the rail grinding machine;

FIG. 4 is a front view of the rail grinding machine;

FIG. 5 is a first sectional view of the rail grinding machine taken along the section line V-V shown in FIG. 3;

FIG. 6 is a top view of the rail grinding machine to illustrate clear viewing areas;

FIG. 7 is a second sectional view taken along the section line VII-VII shown in FIG. 6 to illustrate the height adjustment device of the rail grinding machine without the grinding unit;

FIG. 8 is a perspective view of a rail grinding machine according to a second exemplary embodiment;

FIG. 9 is a perspective view of a rail grinding machine according to a third exemplary embodiment; and

FIG. 10 is a top view of the rail grinding machine in FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawings in detail and first, particularly to FIGS. 1-7 thereof, there is shown a first exemplary embodiment of the invention. A rail grinding machine 1 shown in the figures is used for grinding a rail 2 of a track 5. The track 5 comprises rails 2, 3 in a conventional manner, which are attached to sleepers 4. The track 5 is shown in FIG. 4.

The rail grinding machine 1 comprises a machine frame 6, two rail guide units 7, 8 for guiding the rail grinding machine 1 on the rail 2, a grinding unit 9, a height adjustment device 10 for adjusting the height of the grinding unit 9 relative to the machine frame 6 and a handle 11 for manually moving the grinding unit 9 or the rail grinding machine 1.

The first rail guide unit 7 and the second rail guide unit 8 are arranged on the machine frame 6 spaced apart from one another in a longitudinal direction x. In a working position, in which the rail grinding machine 1 is arranged on the rail 2, the longitudinal direction x runs substantially parallel to a rail longitudinal direction of the rail 2. The first rail guide unit 7 and the second rail guide unit 8 can be pivoted about a longitudinal axis 12 relative to the machine frame 6.

The rail guide units 7, 8 respectively comprise a base body 13, which is arranged on the machine frame 6 so that it can be pivoted about the longitudinal axis 12. Furthermore, the rail guide units 7, 8 respectively comprise two dish-shaped discs 14, 15, a guide roller 16 and a guide hook 17. The dish-shaped discs 14, 15 are arranged at an angle relative to each other and can be rotated about associated axes 18, 19. The rail guide units 7, 8 can be placed against the rail 2 in various pivot positions in the conventional way in order to carry out a grinding operation.

The machine frame 6 is designed as a machine framework. The machine frame 6 comprises a lower longitudinal member 20, an upper longitudinal member 21, a first side member 22 and a second side member 24. The first side member 22 and the second side member 23 are spaced apart from one another in the longitudinal direction x and connect the lower longitudinal member 20 with the upper longitudinal member 21. The lower longitudinal member 20 has a curved shape and extends from the rail guide units 7, 8 in a transverse direction y away from the longitudinal axis 12. The transverse direction y runs perpendicular to the longitudinal direction x. The side members 22, 23 and the upper longitudinal member 21 are together U-shaped and arranged relative to the rail guide units 7, 8 in such a way that the upper longitudinal member 21 extends away from the longitudinal axis 12 in the transverse direction y corresponding to the lower longitudinal member 20.

The height adjustment device 10 is attached to the machine frame 6. The height adjustment device 10 comprises a guide 24, a carriage 25, a spindle drive support 26, a spindle drive 27 and a damping element 39. The guide 24 is a linear guide. The guide 24 is used to adjust the height of the grinding unit 9 in an adjustment direction z. The adjustment direction z runs perpendicular to the longitudinal direction x and the transverse direction y.

The guide 24 contains a first guide unit 28 and a second guide unit 29. The guide units 28, 29 are spaced apart from one another in the longitudinal direction x and respectively attached to the lower longitudinal member 20 and to the spindle drive support 26, which is in turn attached to the upper longitudinal member 21. The first guide unit 28 comprises a first guide element 30, on which a first guide sleeve 31 is displaceably guided. Accordingly, the second guide unit comprises a second guide element 32, on which a second guide sleeve 33 is displaceably guided. The guide elements 30, 32 are designed as guide bars. The guide elements 30, 32 are attached to the lower longitudinal member 20 and via the spindle drive support 26 to the upper longitudinal member 21. The guide elements 30, 32 run parallel to one another in the adjustment direction z. The guide sleeves 31, 33 can accordingly be displaced between the lower longitudinal member 20 and the upper longitudinal member 21 in the adjustment direction z. The guide elements 30, 32 and the associated guide sleeves 31, 33 have, for example, a circular cross-section.

The first guide unit 28 has a first central longitudinal axis M1. Accordingly, the second guide unit 29 has a second central longitudinal axis M2. The central longitudinal axes M1, M2 run parallel to one another in the adjustment direction z. The central longitudinal axes M1, M2 define a guide plane E of the guide 24. The longitudinal direction x and the adjustment direction z run parallel to the guide plane E. The transverse direction y runs perpendicular to the guide plane E and forms a normal vector.

The carriage 25 is attached to the guide sleeves 31, 33 and can be moved together with them in the adjustment direction z. The carriage 25 has a first carriage section 34 and a second carriage section 35, which runs substantially transversely to the first carriage section 34. The first carriage section 34 extends substantially in the longitudinal direction x and the adjustment direction z. By contrast, the second carriage section 35 extends substantially in the longitudinal direction x and the transverse direction y. The spindle drive support 26 runs substantially parallel to the second carriage section 35. The spindle drive support 26 is attached to the upper longitudinal member 21. The spindle drive support 26 extends substantially in the longitudinal direction x and the transverse direction y.

The grinding unit 9 is attached to the height adjustment device 10 and can be moved in the adjustment direction z by means of the height adjustment device 10. The grinding unit 9 is attached to the first carriage section 34.

The spindle drive 27 is used to move the grinding unit 9 in the adjustment direction z. The spindle drive 27 comprises a spindle nut 36, a spindle 37 and a handwheel 38. The spindle drive support 26 has a through opening 40. The spindle nut 36 is attached to the spindle drive support 26 concentrically to the through opening 40. The through opening of the spindle nut 36 has a diameter that is at most as large as the diameter of the through opening 40. The spindle 37 is screwed into the spindle nut 36 and runs through the spindle nut 36 and the through opening 40. A first end 41 of the spindle 37 is rotatably connected to the damping element 39. The damping element 39 is fixedly connected to the second carriage section 35. The handwheel 38 is attached to a second end 42 of the spindle 37. The carriage 25 and the grinding unit 9 attached thereto can be lowered in the adjustment direction z by rotating the spindle 37 about a spindle axis 43 by means of the handwheel 38, or raised against the adjustment direction z if the direction of rotation is reversed. The damping element 39 is used for vibration damping of the spindle drive 27. The damping element 39 is used in particular for vibration decoupling of the grinding unit 9 and the spindle drive 27.

The grinding unit 9 comprises a drive motor 44, a fuel tank 45, a clutch 46 and a tool holder 47. The drive motor 44 is only shown in FIGS. 1, 3, 4 and 5. The drive motor 44 is designed as an internal combustion engine and supplied with fuel by means of the fuel tank 45. The drive motor 44 is connected to the clutch 46, which is in turn connected to the tool holder 47. The tool holder 47 can be or is driven in rotation about an axis of rotation 48 by means of the drive motor 44. A grinding tool 49 is held or attached in or on the tool holder 47. The grinding tool 49 can be driven in rotation about the axis of rotation 48 together with the tool holder 47. The tool holder 47 does not intersect the guide plane E. The tool holder 47 is, for example, configured as a flange to which the grinding tool 49 is attached or screwed. The grinding tool 49 is, for example, a grinding stone. The clutch 46 is used to decouple the drive motor 44 and the tool holder 47 with respect to axially acting force peaks and/or force peaks acting about the axis of rotation 48, so that force peaks are dampened.

The axis of rotation 48 is spaced apart from the guide plane E in the transverse direction y. The axis of rotation 48 is spaced apart from the guide plane E in the transverse direction y in particular in the region of the tool holder 47 and grinding tool 49. This is shown by way of example in FIG. 5. The axis of rotation 48 is arranged on the same side of the guide plane E as the longitudinal axis 12. The following applies in particular for a distance A of the axis of rotation 48 from the guide plane E in the transverse direction y: 1 cm < A ≤ 40 cm, in particular 3 cm ≤ A ≤ 30 cm, in particular 4 cm≤ A ≤ 20 cm, and in particular 5 cm ≤ A ≤ 10 cm.

The spindle axis 43 is arranged between the guide plane E and the axis of rotation 48 when viewed in the transverse direction y. The spindle axis 43 is therefore spaced apart from the guide plane E and the axis of rotation 48 in the transverse direction y. The spindle axis 43 is arranged on the same side of the guide plane E as the axis of rotation 48. The spindle axis 43 is at a distance B from the guide plane E in the transverse direction y, wherein the following applies in particular for the distance B: 1 cm ≤ B < 40 cm, in particular 3 cm ≤ B ≤ 30 cm, in particular 4 cm ≤ B ≤ 20 cm, and in particular 5 cm ≤ B ≤ 10 cm. In particular: B < A.

The handle 11 is used to manually move the rail grinding machine 1 along the rail 2 and/or to manually tilt the rail grinding machine around the rail 2. By moving the rail grinding machine 1 by means of the handle 11, the grinding unit 9 for grinding the rail 2 is also moved manually. The handle 11 is arranged on the same side of the guide plane E as the spindle axis 43 and axis of rotation 48. The spindle axis 43 and axis of rotation 48 are arranged between the guide plane E and the handle 11 when viewed in the transverse direction y. The spindle axis 43 and axis of rotation 48 are thus arranged on a side of the guide plane E facing the handle 11. The grinding unit 9 is arranged in an intermediate space between the guide plane E and the handle 11.

The handle 11 is bow-shaped. The handle 11 comprises a lower longitudinal bar 50, an upper longitudinal bar 51, a first side bar 52 and a second side bar 53. The first side bar 52 and the second side bar 53 are spaced apart from one another in the longitudinal direction x and connect the lower longitudinal bar 50 with the upper longitudinal bar 51. The upper longitudinal bar 51 is used substantially as a handle bar for an operator.

The handle 11 is attached to the rail guide units 7, 8 and can be pivoted together with them about the longitudinal axis 12. In addition, the handle 11 can be adjusted relative to the rail guide units 7, 8 by pivoting and locked in the set pivot position. A foldable stand 54 is attached to the lower longitudinal bar 50 for setting down the rail grinding machine 1.

The rail grinding machine 1 works as now described.

The rail grinding machine 1 is first positioned with the rail guide units 7, 8 on the rail 2 to be ground. The rail guide units 7, 8 are set and locked in a desired pivot position about the longitudinal axis 12. The grinding tool 49 is driven in rotation about the axis of rotation 48 by means of the drive motor 44. An operator holds the rail grinding machine 1 by the handle 11.

The grinding tool 49 can be moved in the adjustment direction z by the operator by means of the handwheel 38 and fed to the rail 2. In the position of the rail grinding machine 1 shown in the figures, head grinding is carried out on a rail head 2‘ of the rail 2. For head grinding, the operator can manually move the rail grinding machine 1 along the rail 2 by means of the handle 11.

Due to the fact that the axis of rotation 48 is spaced apart from the guide plane E in the transverse direction y in the region of the tool holder 47, the rail grinding machine 1 forms clear viewing areas S1 and S2, which are arranged between the rail guide unit 7 and the grinding tool 49 or between the second rail guide unit 8 and the grinding tool 49 when viewed in the longitudinal direction x. The clear viewing areas S1 and S2 are shown in particular in the top view according to FIG. 6. The clear viewing areas S1 and S2 give the operator a clear view of the rail 2 or the rail head 2‘ to be ground. Corresponding clear viewing areas S1 and S2 result when the operator tilts the rail grinding machine 1 in the direction of the machine frame 6 around the rail 2 in order to carry out side grinding of the rail head 2‘. During the grinding operation, the spindle drive 27 for adjusting the height of the grinding unit 9 is vibration-damped by means of the damping element 39.

A second exemplary embodiment of the invention is described below with reference to FIG. 8. Unlike the first exemplary embodiment, the first guide unit 28 additionally comprises a lower damping element 55 and an upper damping element 56. The first guide element 30 is attached to the lower longitudinal member 20 by means of the lower damping element 55 and to the spindle drive support 26 or the upper longitudinal member 21 by means of the upper damping element 56. Accordingly, the second guide unit 29 comprises a lower damping element 57 and an upper damping element 58. The second guide element 32 is attached to the lower longitudinal member 20 by means of the lower damping element 57 and to the spindle drive support 26 or the upper longitudinal member 21 by means of the upper damping element 58. The damping elements 55 to 58 are used for vibration decoupling of the grinding unit 9 and the handle 11. Vibrations acting on the guide 24 from the grinding unit 9 during the grinding operation are damped by means of the damping elements 55 to 58 such that the vibrations acting on the machine frame 6 and the handle 11 are reduced.

The lower damping elements 55, 57 respectively have a first spring stiffness, whereas the upper damping elements 56, 58 respectively have a second spring stiffness. The first spring stiffness is different to the second spring stiffness. The first spring stiffness is in particular greater than the second spring stiffness. This prevents undesired oscillation of the height adjustment device 10 or of the grinding unit 9 attached thereto. Reference is made to the description of the preceding exemplary embodiment in terms of the further design and further mode of operation.

A third exemplary embodiment of the invention is described below with reference to FIGS. 9 and 10. Unlike the preceding exemplary embodiments, the spindle axis 43 and axis of rotation 48 are arranged on a side of the guide plane E facing away from the handle 11. The spindle axis 43 and axis of rotation 48 are arranged on a first side of the guide plane E, whereas the handle 11 is arranged on a second side of the guide plane E. In contrast to the preceding exemplary embodiments, the handle 11 is therefore arranged on the other side of the guide plane E. The grinding unit 9 is therefore not arranged in an intermediate space between the machine frame 6 and the handle 11. This also results in clear viewing areas S1 and S2 on the rail head 2‘ of the rail 2 to be ground. The drive motor 44 is not shown in FIGS. 9 and 10. Reference is made to the description of the preceding exemplary embodiments in terms of the further design and further mode of operation of the rail grinding machine 1.

Generally speaking, the individual features of the exemplary embodiments can be combined in any way.