A forestry winch with a mechanical stop switch

Abstract

A forestry winch with a mechanical stop switch for termination of winding the rope (1) on the drum of the winch. The mechanical stop switch comprises a movable part (3), a Bowden cable (6), wherein the end element of the pulling rope is arranged to interact with the movable part (3), to which a Bowden cable (6) is attached so that upon interaction of the end part with the movable part the Bowden is moved towards a clutch of the winch. As the other part of the Bowden cable is attached to a part of the clutch, the movement of the Bowden towards the clutch shifts said clutch to stop winding of the rope.

Description

Field of the invention

[0001] The present invention belongs to the field of mechanical engineering, more precisely to the field of safety devices for forestry winches. The invention relates to a forestry winch with a mechanical stop switch for termination of winding the rope on the drum of the winch.The technical problem

[0002] During winding of a rope onto a drum of a winch the user often terminates winding too late and the rope is then stuck between layers of rope on the drum or the rope or its end is torn. In all cases work has to be terminated and the problem addressed. Often the rope is terminally damaged, in particular if it was stuck between layers on the drum and thus compressed or permanently deformed. The deformed rope can be unwound with a large pulling force, as smaller forces are not sufficient. In case the winding of the rope onto the drum of the winch is not timely stopped, it may even damage other constructional elements of the winch, most commonly the guide of the rope.

[0003] The technical problem, which is solved by the present invention, is a constructional design of a mechanism for reliable and almost immediate termination of winding (pulling) function in a winch. This means that the termination of the winding function in a winch has to be suitable for winches with electrical, hydraulic or mechanic control of the unwinding sheave, including winches with our without a driven sheave.

[0004] The purpose and the aim of the invention is such constructional solution for termination of winding that will enable safe winch operation, prevent any damage on the machine and equipment and will consequently decrease the costs for winch maintenance.State of the art

[0005] European patent EP3095748 discloses a solution of a winch with a safety mechanism for switching off winding of a rope, is that switching off of the end switch (10) releases a pushing (5) element, which is pushed into the end switch by a rotatably mounted washer (6) on an accessory (3a) on a rope guide, when the accessory of an end piece due to winding of the pulling rope reaches the washer and pushes it into its final position. The mechanism may be installed in winches with electric, hydraulic or mechanic steering of winding and unwinding of the pulling rope with or without a driven sheave. This solution differs from the present invention in that the termination of winding is not exclusively mechanical.

[0006] JPS6050697U discloses an automatic stop device for a winch for an automobile, according to the preamble of claim 1, comprising: a rotary piece rotatably supported about a fulcrum provided on a material, wherein a stopper formed in the vicinity of a free end of a rope of the winch is adapted to push an end portion of the rotary piece when the rope of the winch is wound, and the other end of a wire fixed to a clutch operating arm whose one end is turned on and off for turning on and off a clutch of a PTO is positioned toward a surface of an intermediate portion of the rotary piece in a direction of a winch body. This solution differs in the function of intermediate elements between the rotary piece and the clutch. Description of the solution of the technical problem

[0007] The technical problem is solved as defined in the independent claim, wherein the preferred embodiments are defined in dependent claims.

[0008] The essence of the forestry winch with a mechanical stop switch according to the invention is in that the end part of a rope is arranged for interaction with a movable part to which a Bowden cable is attached so that upon interaction (contact) of the end part with the movable part the Bowden is moved towards a clutch of the winch or its handle. As the other part of the Bowden cable is attached to a part of the clutch, movement of the Bowden towards the clutch shifts it in neutral (idle), because movement of the Bowden releases a restraining element, which has kept the clutch in the gear during winding of the rope. The end part of the rope may push the movable part directly or indirectly via a mechanical intermediate part and a pushing element. A characteristic of the mechanical stop switch according to the invention is in that the end element of the pulling rope may trigger switching off of the pulling process, which is enabled with a transfer of movement of the Bowden that allows transmission of mechanical forces or energy between two machine elements, in this case it thus mechanically switches the handle of the clutch, which terminates the pulling process.

[0009] The mechanical stop switch comprises: a movable part installed on a housing of a guide of a pulling rope, which is wound on the drum of the winch, a Bowden cable, which connects the said movable part with a clutch, wherein the Bowden is connected with the movable part so that the latter may move the Bowden; a wire rope, which runs inside the Bowden cable, and is attached to the housing of the rope guide; a clutch with a restraining element for ensuring connection with the drum drive; a release element, which is on one side attached to the Bowden and on the other side to the clutch near the restraining element, so that it may release the restraining element and thus dislocates the clutch from the drum drive;

[0010] Wherein the movable part upon interaction with the end part of the rope causes movement of the Bowden and consequently moves the release element so that the clutch moves away from the drive axis and is immediately stopped.

[0011] The movable part may be made as a one piece element or may comprise a holder and an accessory or a guide and a bush, which is movable inside the said guide, or in any other suitable way. In case the accessory is designed as a bush, through which the rope runs, the wider part of the bush is the part for interaction with the end part of the rope. In case the accessory is designed as a bush, through which the pulling rope runs, the wider part of the bush is the one into which the end part of the rope hits. The bush may be via suitable elements connected with the wire rope and the Bowden, so that the latter may be moved towards the clutch. Preferably the accessory is designed so that it is connected to the pushing plate on the housing of the rope guide, wherein through the pushing plate the pulling rope with the end piece runs, the end piece being arranged to push the pushing plate, which causes movement of the movable part as well as the Bowden towards the clutch.

[0012] An alternative variant is that winding and unwinding is controlled hydraulically, wherein the hydraulics essentially comprise a hand- or leg-controlled manual hydraulic pump connected to a reservoir for hydraulic liquid and to a hydraulic cylinder via hydraulic pipes. The hydraulic cylinder is in this embodiment the restraining element, which controls the position of the clutch with regards to the drum drive. When the manual hydraulic pump is started pressure in the hydraulic system is created and the hydraulic cylinder attached with its piston directly or indirectly to the clutch pushes the later in contact with the drum drive, so that the drum is in contact with a sprocket. Consequently, the drum starts rotating and winding of the rope and thus pulling of the load is initiated. A further component is a hydraulic valve provided near the Bowden, so that movement of the latter triggered by activation of the movable part upon interaction with the rope end part results in switching of the state of the hydraulic valve, which in turn results in deactivation of winging (pulling of the load). The valve is connected to the Bowden or to the movable part directly via the valve's handle, while the said valve is also connected with the reservoir and consequently the hydraulic cylinder. As the valve is connected into the hydraulic scheme, it is able to change the pressure, so that the hydraulic cylinder directly or indirectly attached with its piston to the clutch removes it from the drum drive (i.e. drum axle), wherein the drive is terminated between the sprocket and the drum. Thus, winding is terminated and pulling of the load no longer occurs. Said valve, cylinder and pump may be any suitable known in the field.

[0013] The mechanical stop switch may be installed in any winch with electrical, hydraulic or mechanical control of winding and unwinding of the pulling rope with or without an unwinding sheave.

[0014] The forestry winch with the mechanical stop switch according to the invention will be described in further detail based on exemplary embodiments and figure 1, which shows a possible embodiment of the mechanism according to the invention.

[0015] A usual forestry winch has a pulling rope, which is mounted perpendicularly to the axis of a drum and swings along the longitudinal axis of the drum, wherein the rope is guided via directing cylinders towards an exit opening. On the outer side of the frame of the winch a console with a housing of an unwinding sheave may be mounted, wherein it is movably or rotatably mounted around the vertical axis or around an axis which is slightly slanted from the said vertical axis.

[0016] The forestry winch with the mechanical stop switch according to a possible embodiment is characterized in that the end part 11 of the pulling rope 1 is arranged to move the movable part 3, which preferably comprises a pushing plate 31, a transverse element 32 and a holder 33, wherein the transverse element 32 connects the pushing plate 31 with the holder 33. Upon interaction of the end part 11 the movable part 3 is moved towards the direction of winding of the rope 1, wherein the pushing plate 31 is in its bottom part 31a movably installed on the bottom part of the exit part 22 of the housing 2 of the pulling rope 1 guide. The pushing plate 31 is movably attached to the housing 2 in order to maintain a suitable distance so that the movable part 3 may be moved upon interaction with the end part 11. The movable part 31 is installed in the upper part of the housing 2. A wire rope 4 is fixedly mounted onto the housing 2 in the mounting 41, the said wire 4 being enclosed with the Bowden 6, which is movable and mounted into the holder 33 of the movable part 3 in the mounting 5, which is partially visible in figure 1. The Bowden 6 is cut in figure 1, however its other part is connected to the clutch, preferably to the release element installed on a part of the clutch where the restraining element is provided, the latter ensuring contact with the drum drive during winding. Upon contact of the movable part 3 or the pushing plate 31 with the end part 11 of the pulling rope 1, the holder 33 is together with the Bowden 6 moved in the direction towards the clutch, which enables a direct switching off of the clutch that otherwise enables winding of the pulling rope onto the drum of the winch. Upon movement of the Bowden 6 in the direction towards the clutch (not shown in the figure) the release element mounted on a part of the clutch (preferably on its handle) is released, so that the clutch is dislocated and moved away from the drive, thereby terminating rotation of the drum. The Bowden may be attached to the part of the clutch or to the release element in any suitable way that allows movement of the clutch into neutral (idle) upon movement of the Bowden. Another possible solution is also to attach the Bowden to a handle of the clutch, the handle causing the clutch to shift into neutral.

[0017] The forestry winch with the mechanical stop switch according to a possible embodiment is made so that onto the housing of the winch the housing 2 of the rope 1 guide is movably mounted, the rope 1 having an end part 11. On the upper part of the housing 2 two holes are provided in the axis that is transverse to the longitudinal axis of the housing 2. In the bottom part of an exit part 22 of the housing 2 two holes are provided in the axis transverse to the longitudinal axis of the housing 2, wherein through the holes sides 31b of the pushing plate 31 are mounted. This allows movable (swivel, rotation) mounting of the bottom part of the pushing plate 31, which has a hole for the pulling rope 1 and a site for connection with the transverse element 32 in the upper part of the plate 31.

[0018] The transverse element 32 is preferably designed as a long base element with an elongation on each side, both elongations being bent for 90° from the base element. It is equipped with suitable holes for connection with the pushing plate 31 and the holder 33. Below the basic element a mounting 41 for fixed mounting of the wire rope 4 is provided.

[0019] The holder 33 preferably comprises a base plate with two elongations, which are provided on each side and enable movable mounting into the housing 2. On the upper part of the base plate is a mounting for the transverse element 32, below it a mounting for the Bowden 6, which may be any suitable mounting that allows movement of the Bowden once the holder 33 is moved due to the interaction of the plate 31 with the end part 11 of the pulling rope 1. In this way movement of the Bowden 6 is allowed, which transfers the pushing force onto the movable part of the clutch of the drum. Preferably the clutch is designed with a restraining element of any type, which enables holding the clutch in contact with the drum drive and thus winding of the rope. The clutch is also provided with a release element, which is on one side attached to the Bowden 6 and on the other side to the clutch near the restraining element, so that the release element may release the restraining element and consequently moves the clutch away from the drum drive. One of the possibilities is that the release element has a groove into which the restraining element may be moved. This allows simple and reliable mechanical connection for switching off rotation of the drum of the winch.

[0020] The winch with the mechanical stop switch is preferably equipped with the movable part, of which the pushing plate comes into contact with the end part of the pulling rope, which runs through the opening of the said plate. The pushing plate enables reliable operation and triggers movement of the holder and the Bowden only in case the end part on the rope interacts with the plate. Then, the latter moves, due to its rigid connection with the holder via the transverse element, the Bowden attached to the holder may be moved towards the clutch. This causes a movement in the part of the clutch and release of the restraining element in the clutch, thereby causing the clutch to dislocate from the drum. Consequently winding of the rope is immediately terminated.

Claims

1. A forestry winch with a mechanical stop switch, a pulling rope (1) and a drum, wherein the mechanical stop switch comprises: - a guide for the pulling rope (1), - a housing (2) for the guide, - a clutch, - a movable part (3) installed on the housing (2) of the guide of the pulling rope (1), which is wound on the drum of the winch, - a Bowden cable (6), - a wire rope (4), which runs inside the Bowden cable (6), - wherein the clutch is provided with a restraining element for ensuring connection with the drum drive; - a release element, - the end part (11) of the rope (1) is arranged for interaction with the movable part (3), characterized in that - the wire rope (4) is attached to the housing (2); - the release element is on one side attached to the Bowden cable (6) and on the other side to the clutch near the restraining element, so that it may release the restraining element and thus dislocates the clutch from the drum drive; - the Bowden cable (6) connects the said movable part (3) with the clutch, wherein the Bowden cable is connected with the movable part (3) so that the latter may move the Bowden cable (6), - the Bowden cable (6) is attached to the movable part (3), so that upon interaction of the end part (11) with the movable part (3) the Bowden cable (6) is moved towards the clutch of the winch; and - the other part of the Bowden cable (6) is attached to a part of the clutch, so that movement of the Bowden towards the clutch shifts it in neutral, as the restraining element, which has kept the clutch in the gear during winding of the rope, is released, - such that the movable part (3) interaction with the end part (11) of the rope (1) causes movement of the Bowden cable (6) and consequently moves the release element so that the clutch moves away from the drive axis and the winding of the rope onto the drum of the winch is immediately stopped.

2. The forestry winch with a mechanical stop switch according to claim 1 characterized in that the end part of the pulling rope may press onto the movable part directly or indirectly via a mechanical intermediate part and a pushing element.

3. The forestry winch with a mechanical stop switch according to any of the preceding claims, characterized in that the movable part (3) is made in one piece or is made from several pieces.

4. The forestry winch with a mechanical stop switch according to claim 3, characterized in that the movable part (3) comprises a holder and an accessory, or a guide and bush, or a pushing plate (31) connected to the holder (33) with a transverse element (32).

5. The forestry winch with a mechanical stop switch according to claim 4, characterized in that the movable part (3) comprises the pushing plate (31), the transverse element (32) and the holder (33), wherein the transverse element (32) connects the pushing plate (31) with the holder (33); wherein the said movable part (3) upon contact with the end part (11) of the pulling rope (1) is moved in the direction of winding of the rope (1), and wherein the pushing plate (31) is in its bottom part (31a) movably mounted on the housing (2) of the rope (1) guide, while the movable part (3) is installed in the upper part of the housing (2); and wherein the wire rope (4) is fixedly mounted onto the movable part (3), said wire rope (4) being surrounded by the Bowden (6), which is movable and is mounted on the holder (33) of the movable part (3) in a mounting (5).

6. The forestry winch with a mechanical stop switch according to claim 5, characterized in that the transverse element (32) is preferably designed as a long base element with an elongation on each side, both elongations being bent for 90° from the base element; and that the transverse element (32) is equipped with suitable holes for connection with the pushing plate (31) and the holder (33), wherein below the base element a mounting (41) for fixed mounting of the wire rope (4) is provided.

7. The forestry winch with a mechanical stop switch according to claim 6, characterized in that the holder (33) preferably comprises a base plate with two elongations, which are provided on each side and enable movable mounting onto the housing (2); that on the upper part of the base plate is a mounting for the transverse element (32), below it a mounting for the Bowden (6), which may be any suitable mounting that allows movement of the Bowden once the holder (33) is moved due to the interaction of the plate (31) with the end part (11) of the pulling rope (1).

8. The forestry winch with a mechanical stop switch according to any of the preceding claims, characterized in that the clutch is designed with a restraining element of any type, which enables restraining the clutch in contact with the drum drive and thus winding of the rope.

9. The forestry winch with a mechanical stop switch according to the preceding claim, characterized in that the said release element has a groove, into which the restraining element is moved.

10. The forestry winch according to claim 9, characterized in that winding and unwinding is controlled hydraulically, wherein the hydraulics essentially comprise a hand- or leg-controlled manual hydraulic pump connected to a reservoir for hydraulic liquid and to a hydraulic cylinder via hydraulic pipes, wherein the hydraulic cylinder acts as the restraining element, which controls the position of the clutch with regards to the drum drive, and wherein the manual hydraulic pump is arrange to create pressure in the hydraulic system and to push the hydraulic cylinder attached with its piston directly or indirectly to the clutch in contact with the drum drive, so that the drum is in contact with a sprocket and thus pulling of the load is initiated; and in that a further component is a hydraulic valve provided near the Bowden, so that movement of the latter triggered by activation of the movable part upon interaction with the rope end part results in switching of the state of the hydraulic valve, which in turn results in deactivation of winding, wherein the valve is connected to the Bowden or to the movable part directly via the valve's handle, while the said valve is also connected with the reservoir and consequently the hydraulic cylinder, and wherein the valve is arranged to change the pressure upon activation of the movable part, so that the hydraulic cylinder directly or indirectly attached with its piston to the clutch removes it from the drum drive thus terminating winding of the rope.

11. The forestry winch with a mechanical stop switch according to any of the preceding claims, characterized in that the winch may have electrical, hydraulic or mechanic control of the unwinding sheave, including winches with our without a driven sheave.

Images