The invention relates to a hydraulic damping device. The invention relates also to a hinge arrange- ment provided with the hydraulic damping device. Fur- ther, the invention relates also to a machine provided with the hinge arrangement.

BACKGROUND OF THE INVENTION

Different kind of machines may comprise vari- ous hatches, hoods or doors that may be rather heavy and therefore an uncontrollable closure of the hatch- es, hoods or doors may lead to hazardous situations or even injuries.

Various devices have been introduced in con- nection with the hatches, hoods, or doors for avoiding uncontrollable closing of them. However, these are of- ten intended only for lighter use or they need extra space or are exposed to damages.

Hydraulic damping devices of different types are frequently used, for instance in vehicles, in or- der to influence the mutual movements between differ- ent components. However, these may be intended for a rather light use and their assembly may be rather com- plicated.

OBJECTIVE OF THE INVENTION

The objective of the invention is to allevi- ate the disadvantages mentioned above.

SUMMARY According to a first aspect, the present in- vention provides a hydraulic damping device in a hinge arrangement arranged to connect a hatch or a hood or a door to a support surface of a mine machine comprising a housing having a cylinder space defined by a cylin- drical inner wall of the housing, a piston arranged movably in the cylinder space, a piston rod arranged to the piston and extending to the outside of the housing, means for moving the piston from a first po- sition, in which the piston rod is in a retracted po- sition, to the second position, in which the piston rod is in an extended position, and a fluid tank oper- ationally connected via fluid channel to the cylinder space.

According to the invention the damping device is configured to dampen a movement of the piston and the piston rod from the extended position of the pis- ton rod to the retracted position of the piston rod achieved by an external force directed to the piston rod, wherein a fluid flow is achieved by pressing with the piston the fluid from the cylinder space to the fluid tank via the fluid channel, and the device com- prises means for returning the piston to the extended position of the piston rod when the external force is not directed to the piston rod.

According to a second aspect the present in- vention provides a hinge arrangement arranged to con- nect a hatch or a hood or a door to a support surface of a mine machine comprising a first hinge part, a second hinge part, a hinge axis, wherein the first and/or second hinge part are arranged to rotate rela- tive to each other around the hinge axis. The hydrau- lic damping device, according to any one of embodi- ments mentioned below or above alone or in combination of other embodiment, may be arranged in the hinge ar- rangement. The first hinge part or the second hinge part or a contacting part may be arranged to contact and press the piston rod. In an embodiment a contact- ing part may be arranged to the first hinge part or to the second hinge part. In an embodiment the first hinge part or the second hinge part or the contacting part may be arranged to contact and press the piston rod of the hydraulic damping device at least in a por- tion of an angle of rotation of the hinge parts about the hinge axis.

According to a third aspect the present in- vention provides a mine machine comprising a hatch or a hood or a door. The hatch or the hood or the door may be connected to a support surface of the machine with a hinge arrangement according to any one of em- bodiments mentioned below or above alone or combined with other embodiment.

The technical effect is that by damping de- vices may be used in relation to different kind of hatches or hoods or doors to absorb an impact of un- controllable closing of the hatch or the hood or the door and therefore avoiding objects to catch the clos- ing hatch or hood or door and an edge of the opening the hatch or hood or door is intended to cover. The damping device may be a safety device arranged to ve- hicles or machinery with hatches or hoods or doors. The further technical effect is that the hinge ar- rangement may comprise the damping device and there- fore they form a compact combination of the hinge and the damping device.

The dumping device, the hinge arrangement and the machine are characterized by what is stated in the independent claims.

Some other embodiments are characterized by what is stated in the other claims. Inventive embodi- ments are also disclosed in the specification and drawings of this patent application. The inventive content of the patent application may also be defined in other ways than defined in the following claims. The inventive content may also be formed of several separate inventions, especially if the invention is examined in the light of expressed or implicit sub- tasks or in view of obtained benefits or benefit groups. Some of the definitions contained in the fol- lowing claims may then be unnecessary in view of the separate inventive ideas. Features of the different embodiments of the invention may, within the scope of the basic inventive idea, be applied to other embodi- ments.

In an embodiment of the hydraulic damping de- vice the piston may be arranged to divide the cylinder space to a first chamber on a first side of the piston and to a second chamber on a second side of the pis- ton. The first chamber and the second chamber may be connected with each other via first and second flow channels arranged in the piston. A valve may be ar- ranged to the piston, said valve may be arranged to allow flow of fluid via first flow channels in a first direction of flow and to keep the first flow channels closed in a second direction of flow, the first direc- tion of flow being when the piston is moved from a first position in which position the piston rod is in the retracted position to a second position in which position the piston rod is in the extended position, and the second direction of flow being when the piston is moved from the second position, in which second po- sition the piston rod is in the extended position, to the first position, in which first position the piston rod is in the retracted position.

In an embodiment of the hydraulic damping de- vice an adjusting device may be arranged for adjusting of the damping effect by adjusting of flow rate of the fluid. In an embodiment the adjusting device may be arranged for adjusting of the damping effect by ad- justing of flow rate of the fluid via the second chan- nel between the first chamber space and the second chamber space. In an embodiment the damping effect may be adjusted by adjusting an intake or an output of re- placement air via a vent arranged to the damping de- vice. An advantage for embodiments is that the damping device with an adjusting device may be easily adapted to be utilized with various different embodiments.

In an embodiment of the hydraulic damping de- vice the adjusting device may comprise a tapered pin arranged or formed on a spindle arranged in a boring of the piston rod. In an embodiment the spindle may be arranged in a boring arranged in a longitudinal axis of the piston rod and extending to the second flow channel. In an embodiment a threading may be arranged on an inner surface of the boring for the spindle and a counter threading may be arranged on the spindle. An advantage for these embodiments is that the adjusting device may be easy to set up for different embodiments by turning the spindle by a tool, such as by a screw- driver, for example from a slot arranged on an end of the spindle.

In an embodiment of the hydraulic damping de- vice means for returning the piston to the extended position of piston rod may comprise a spring. In an embodiment the spring may be arranged to the cylinder space between the piston and an end of the cylinder space. An advantage is that a spring is a simple and reliable solution for the returning means of the pis- ton and the piston rod.

In an embodiment of the hydraulic damping de- vice the fluid tank may comprise pressure means. An advantage for this embodiment is that by it is a suf- ficient way to keep the fluid pressure in the damping device high enough to move the piston and the piston rod of the damping device to the extended position of the piston rod.

In an embodiment of the hydraulic damping de- vice the fluid tank may comprise a cylinder space and a second piston arranged movably in the cylinder space and a spring arranged to press the piston towards the fluid channel part of the cylinder space. In an embod- iment a spring may be arranged to the fluid tank for pressing the piston of the fluid tank and keeping the fluid pressure in the damping device high enough to move the piston and the piston rod of the damping de- vice to the extended position of the piston rod.

In an embodiment of the hydraulic damping de- vice the fluid tank is arranged in the housing. An ad- vantage for arranging the fluid tank in the housing is that a compact structure for the combination of the damping device and the fluid tank may be achieved. In an embodiment of the hydraulic damping device the hy- draulic damping device may comprise a plurality of fluid tanks. In an embodiment the housing may be com- prise a plurality of fluid tanks arranged in the one housing of the damping device. An advantage is that the housing may be made to form a block that comprises space for the piston, the piston rod and the fluid tanks and the fluid channels. The damping device may form a compact module that is easy to connect with a hinge arrangement and/or a support structure. The damping device may also be formed as strong and for heavy duty uses, such as for use with mine machines.

In an embodiment of the hydraulic damping de- vice the housing may comprise a fixing point to a hinge part. In an embodiment of the hydraulic damping device the housing the fixing point is a threaded hole. An advantage for arranging a fixing point in the damping device for the hinge part is that it may be help for connecting the damping device and the hinge to a support structure.

In an embodiment of the hinge arrangement the hinge arrangement is arranged to connect a hatch or a hood or a door to a machine or a vehicle. In an embod- iment the hinge arrangement may be connected to a min- ing machine.

In an embodiment of the hinge arrangement the damping device and the first hinge part or the second hinge part may be arranged to common fixing points.

In an embodiment of the machine the hatch or the hood is connected to the structures of the machine with a hinge arrangement according to any one of the embodiments mentioned above alone or in combination with other embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illus- trate embodiments of the invention and together with the description help to explain the principles of the invention. In the drawings:

Figure 1 is a schematic representation of a side view of a cross section of an embodiment of a damping device, a piston in an extended position,

Figure 2 is a schematic representation of a side view of a cross section of an embodiment of a damping device, a piston in a retracted position,

Figure 3 is a schematic representation of a cross section of line A-A of figure 4 of an embodiment of a damping device,

Figure 4 is a schematic representation of an embodiment a damping device from direction of arrow B of Figure 3,

Figure 5 is a schematic representation of an embodiment of a hinge arrangement with a damping de- vice,

Figure 6 is a schematic representation of an embodiment of a machine utilizing an embodiment of a hinge arrangement with a hatch, the hatch in an opened position, In the figures, some embodiments are shown simplified for the sake of clarity. Similar parts are marked with the same reference numbers in the figures.

DETAILED DESCRIPTION

In figures 1 and 2 is schematically and sim- plified illustrated an embodiment of a hydraulic damp- ing device 1. In an embodiment of a hydraulic damping device 1 may comprise a housing 2. The housing may comprise a cylinder space 3. The cylinder space may be defined by an inner wall 4 of the housing 2. In an em- bodiment the inner wall 4 may be cylindrical wall. The cylinder space 3 may have a first end wall 5 and a second end 6. In an embodiment the second end 6 may be a disc like piece connected to the housing 2, for ex- ample on a shoulder arranged on an edge of an opening of the housing 2. A piston 7 may be arranged movably in an axial direction of the cylinder space 3. The piston 7 may be arranged slidably against the inner wall 4. In an embodiment a piston rod 8 may be ar- ranged to the piston 7. In an embodiment the piston rod may be extending to the outside of the housing 2. In the second end 6 of the cylinder space may comprise an opening 23 for the piston rod 8. The piston rod is slidably and sealingly mounted to the second end of the cylinder space, wherein the piston rod extends through an opening 23 of the second end. On or more sealing members may be mounted to a wall of the open- ing 23 in form a fluid tight seal between the second end 6 and the surface of the piston rod.

In an embodiment the dumping device 1 may further comprise means for moving the piston 7 from a first position, in which the piston rod 8 is in a re- tracted position (figure 2), to the second position, in which the piston rod 8 is in an extended position (figure 1).

In an embodiment of the dumping device a flu- id tank 20 may be operationally connected via fluid channel 19 to the cylinder space 3.

In an embodiment the damping device 1 may be configured to dampen a movement of the piston 7 and the piston rod 8 from the extended position of the piston rod 8 to the retracted position of the piston rod 8 achieved by an external force directed to the piston rod 8. In an embodiment a fluid flow may be achieved by pressing with the piston 7 the fluid from the cylinder space 3 to the fluid tank 20 via the flu- id channel 19. In an embodiment a throttle of an ori- fice of the flow channel may provide the damping ef- fect with help of the flow of the fluid from the cyl- inder chamber to the fluid tank.

In an embodiment the damping device may com- prise means for returning the piston 7 to the extended position of the piston rod 8 when the external force is not directed to the piston rod. In an embodiment means for returning the piston may comprise a spring member arranged between the piston 7 and the first end wall 5 of the cylinder space 3. In an embodiment the spring member may be a coil spring. In an embodiment the returning means may comprise other arrangements as presented in some of the embodiments below.

In an embodiment the piston 7 may be arranged to divide the cylinder space 3 to a first chamber 9 on a first side of the piston 7 and to a second chamber 10 on a second side of the piston. The first chamber 9 and the second chamber 10 may be connected with each other via first flow channels 11 arranged in the pis- ton 7. In an embodiment the first flow channels may be arranged on a longitudinal direction of the piston. In an embodiment the first flow channels 11 may be ar- ranged divided on a circle at a distance in a radial direction from the piston rod 8. In an embodiment a valve 18 may be arranged to the piston. The valve 18 may be arranged to allow flow of fluid via first flow channels 11 in a first direction of flow and to keep the first flow channels 11 closed in a second direc- tion of flow. In an embodiment the valve 18 may be an annular disc. In an embodiment the annular disc form- ing the valve 18 may be arranged to move or bend so that the fluid may flow in the first direction of flow but keep the first fluid channels 11 closed in a sec- ond direction of flow. The first direction of flow be- ing when the piston is moved from a first position in which position the piston rod is in the retracted po- sition to a second position in which position the pis- ton rod is in the extended position, and the second direction of flow being when the piston is moved from the second position, in which second position the pis- ton rod is in the extended position, to the first po- sition, in which first position the piston rod is in the retracted position. In an embodiment second flow channels 13, 14 may be arranged in the piston 7 to connect the first chamber 9 and the second chamber 10 with each. In an embodiment second flow channels may comprise a longitudinal flow channel 12 and radial flow channels 14. In an embodiment the radial flow channels may be arranged divided on a from the longi- tudinal channel to the cylindrical surface of the pis- ton rod 8. A plurality of radial channels 14 may be ranged to form a through holes from the first chamber space 9 via the longitudinal channel 13 to the second chamber part of the cylinder space 3.

In an embodiment of the damping device an ad- justing device 15 may be arranged for adjusting of the damping effect by adjusting of flow rate of the fluid. In an embodiment adjusting device may be arranged to adjusting intake/output of replacement air via a vent 39 arranged to the damping device. In an embodiment the damping efficiency may be adjusted by the viscosi- ty of the fluid. In an embodiment the damping effi- ciency may be improved by using a hydraulic fluid with a higher viscosity, and vice versa, the damping effi- ciency may be reduced by using a hydraulic fluid with a lower viscosity in the damping device. In an embodi- ment the damping efficiency may be adjusted with char- acteristics of a spring, such as spring rate, suitable for returning the piston from retracted position of the piston rod to the extended position of the piston rod 8.

In an embodiment of the damping device the adjusting device 15 may be arranged for adjusting of the damping effect by adjusting of flow rate of the fluid via the second channel 13, 14 between the first chamber space 9 and the second chamber space 10.

In an embodiment the adjusting device 15 may comprise a tapered pin arranged or formed on a spindle 16 arranged in a boring arranged in a longitudinal ax- is of the piston rod 8 and extending to the second flow channel 13, 14 of the piston.

In an embodiment the means for returning the piston 7 to the extended position of piston rod 8 may comprise a spring.

In an embodiment of the hydraulic damping de- vice the fluid tank 20 may comprise pressure means. The pressure means may be arranged to keep the fluid pressure at a suitable level in order to affect the damping effect and possibly also to achieve the re- turning of the piston from the first position to the second position (i.e. the extended position of the piston rod). By arranging pressure means to the fluid tank it may be possible to maintain fluid pressure high enough also in situations in which a position of the damping device is disadvantageous for its opera- tion. In an embodiment the fluid tank 20 may com- prise a cylinder space and a second piston 21 arranged movably in the cylinder space and a spring 22 arranged to press the piston towards the fluid channel 19 part of the cylinder space. In an embodiment an opening of the fluid channel 19 may be arranged on a portion of the fluid tank between piston and the end of the fluid tank. In an embodiment the opening of the fluid chan- nel 19 may be made on a side wall of the fluid tank 20. In an embodiment of the damping device a vent 39 may be arranged to an opposite portion of the fluid tank in relation to fluid channel opening 19. In an embodiment adjusting device may be arranged to adjust- ing intake/output of replacement air via the vent 39 arranged to the damping device.

In an embodiment of the damping device the fluid tank 20 may be arranged in the housing 2. In an embodiment the hydraulic damping device may comprise a plurality of fluid tanks 20. In the embodiment of the figure the damping device may comprise two fluid tanks 20. This makes it possible to keep a fluid pressure at a suitable level and equally distributed. Redundant fluid tanks may also reduce possibilities of malfunc- tion of the damping device. In an embodiment the fluid tank or fluid tanks or a reserve fluid tank may be ar- ranged to be operationally connected to the damping device via a pipe or a hose. In an embodiment the flu- id tank or fluid tanks may be arranged to be opera- tionally connected to the cylinder space of the damp- ing device via a pipe or a hose. In an embodiment the fluid tank or the fluid tanks or the reserve fluid tank may be arranged as a separate unit or separate units in relation to the housing 2 of the damping de- vice 1.

In an embodiment the housing 20 may comprise a fixing point to a hinge part and/or the support structure. In an embodiment the fixing point may be a threaded hole. In an embodiment the threaded hole is arranged on a housing on a surface of an opposite end of the housing in relation to the piston rod.

In an embodiment a hinge arrangement 30 may comprise a first hinge part 31, a second hinge part 32, a hinge axis 33, wherein the first hinge part and/or second hinge part are arranged to rotate rela- tive to each other around the hinge axis 33. The hy- draulic damping device 1 according to any one of em- bodiment mentioned above or below alone or in a combi- nation with other embodiments may be arranged in the hinge arrangement. The first hinge part 31 or the sec- ond hinge part 32 or a contacting part 40 may be ar- ranged to contact and press the piston rod 8 at least in a portion of an angle alpha a of rotation of the hinge parts about the hinge axis. A form and shape of the contacting part 40 may be configured to according to the embodiment to contact the end of the piston rod 8 when the hinge i.e. the first hinge part and/or the second hinge part is moved around the hinge axis (from open state to a closed state). The closed state is presented in figure 4 with a dotted line. In an embod- iment the hatch 41 or the hood or the door connected to the support surface 42 via the hinge arrangement may be arranged to contact the piston rod 18 of the damping device 1. As it can be seen from figure 5 the dotted line of the contacting part 40 may have pressed the piston rod 8 in a closed position of the hatch 41 and the damping device 1 may have dampened the closing of the hatch 41 at least in an end portion of the closing movement of the hatch 41. In an embodiment the contacting part 40 may be arranged to one of the hinge parts 31, 32. In an embodiment the contacting part 40 may be arranged to the other hinge part than which the housing 2 of the damping device 1 is fixed with. In an embodiment the hinge arrangement 30 may be arranged to a hatch 41 or a hood or a door of a ma- chine 100 or a vehicle.

In an embodiment the machine 100 may be a mine machine or a construction machine e.g. a rock drilling rig, a development drill, a tunneling drill- ing machine, a surface drilling machine, a bolting or reinforcing vehicle, a rock removal machine, a long hole drill rig, an explosive charging machine, a load- er, a transport vehicle, a loading machine, or hauling machine, setting vehicle of gallery arcs or nets, a concrete spraying machine, a crusher, a measuring ve- hicle, or a passenger transport vehicle. In figure 6 the machine 100 may be a loading or a hauling machine. In the mine machines there may be rather heavy hatches or hoods, whereby it is advisable in view of safety aspects to use a hinge arrangement 30 with a damping device 1 with the hatches 41 or hoods.

In an embodiment of the hinge arrangement the damping device 1 and the first hinge part 31 or the second hinge part 32 may be arranged to common fixing points 28. In an embodiment the common fixing point 28 may be a threaded hole. In an embodiment the threaded hole may be arranged on a housing 2 of the damping de- vice 1. In an embodiment the fixing point 28 may be arranged on the wall of the housing. In an embodiment the fixing point may be arranged to an end 29 of the housing, opposite to the end of the housing the piston rod 8 is configured to extend.

In an embodiment the machine 100 may comprise a hatch 41 or a hood or a door. In an embodiment the hatch 41 or the hood or door may be connected to a support surface 42 of structures of the machine by the embodiment of the hinge arrangement 30 mentioned above or in a combination with other embodiments mentioned above. In an embodiment a through hole 45 may be ar- ranged through a structure of a support surface 42. A fixing member 44, such as a screw of bolt, may be ar- ranged to extend from a first side of the support sur- face 42 to the second side of the support surface and through an opening arranged to the first hinge part 31 so that the end extending through the support surface 42 and the first hinge part 31 may be positioned to the fixing point 28 of the housing 2 of the damping device 1. A compact hinge arrangement comprising a hinge and a damping device may be easily fixed to the structures of a machine and to a hatch 41.

It is obvious to a person skilled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways. The invention and its embodiments are thus not limited to the examples described above, instead they may vary within the scope of the claims.

Reference symbols

1 Damping device

2 Housing

3 Cylinder space

4 Cylindrical inner wall

5 First end wall

6 Second end

7 Piston

8 Piston rod

9 First chamber

10 Second chamber

11 First flow channel

12 Flow channel opening

13 Second flow channel

14 Third flow channel

15 Flow adjusting member

16 Spindle

17 Slot 18 Check valve (non-return valve)

19 Fluid channel

20 Fluid tank

21 Second piston

22 Spring member

23 Opening

24 Retaining ring

25 Fluid tank first end

26 Fluid tank wall

27 Fluid tank second end

28 Fixing point

29 Wall of the housing

30 Hinge arrangement

31 First hinge part

32 Second hinge part

33 Hinge axis

39 Vent

40 Contacting part

41 Hatch or hood

42 Support surface

44 Fixing member

45 Through hole 100 Machine