A winch with an arrangement for controlling a cable thereof

Abstract

 A winch comprises a driven drum, a cable (6) configured to be wound around the drum and an elongated element (15,16) extending in an endless loop around at least two diverting members (17-20) and configured to bear against the cable (6) at a distance to the drum so as to by friction to the cable (6) move in said endless loop upon movement of the cable (6) along a part (23a,23b) of said loop. The winch further comprises means configured to be able to transfer power to at least one member (17-20) in engagement with the elongated element (15,16) so as to affect the ability of said element (15,16) to move in the endless loop and consequently the cable (6) to move along said part (23a,23b) of the loop.

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a winch comprising a driven drum, a cable configured to be wound around the drum and an elongated element extending in an endless loop around at least two diverting members and configured to bear against the cable at a distance to the drum so as to by friction to the cable move in said endless loop upon movement of the cable along a part of said loop.

[0002] The invention relates to such a winch of any conceivable type, which can be arranged on tractors, stationary or mobile building cranes, boom trucks, vessels, emergency vehicles etc., but a winch arranged on some type of tow truck may be mentioned as a typical example without restricting the invention thereto.

[0003] Such a winch is used for lifting or pulling heavy objects. Arranged at a tow truck the winch is used for pulling other vehicles out of ditches or moving trees lying on the road, as two examples. In another example, such a winch arranged at a building crane is used for lifting and moving building materials on a construction site, such as steel beams or concrete pipes.

BACKGROUND ART

[0004] A winch of the type described in the introduction is previously known through the document DE 203 19 073 U1.

[0005] The winch described in said document is arranged at a mobile crane vehicle and is used for lifting heavy objects. The arrangement comprising said elongated element extending in an endless loop around two diverting members is used to brake the movement of the cable towards the drum when the cable is being wound on the drum so as to establish a well-organized winding of the cable on the drum. Said arrangement comprised in the winch described in said document is a complicated and ineffective solution for controlling the cable, inter alia since it comprises hydraulic cylinders to move the arrangement for controlling its influence on the cable.

[0006] A common problem in use of such winches described when arranged at for example a tow truck is that the cable is very complicated to unwind from the drum because it can have a weight of several hundred kilograms.

SUMMARY OF THE INVENTION

[0007] The object of the present invention is to provide a winch of the type defined in the introduction being improved in at least some aspect with respect to such winches already known, through for example said document.

[0008] This object is according to the invention obtained by providing such a winch, which is characterized in that the winch comprises means configured to be able to transfer power to at least one member in engagement with the elongated element so as to affect the ability of said element to move in the endless loop and consequently the cable to move along said part of the loop. By transferring power to a member in engagement with said element, an ability of the element to efficiently influence the movement of the cable is obtained in an uncomplicated and by that reliable and cost-efficient way.

[0009] According to an embodiment of the invention at least one counter support member is arranged at the opposite side of the cable relative to the elongated element in said part of the loop so as to there urge the cable against said elongated element for movably fixing the cable between this element and the counter support member. Said counter support member may be for instance a fixed plate and may also be a further elongated element. Said counter support member increases the ability of said element to act upon the cable for influencing the movement thereof.

[0010] According to another embodiment of the invention said means able to transfer power to said at least one member is able to impede a movement of the element in said part of the loop in the same direction as the cable move along said part of the loop when the cable is being wound on the drum and said means is consequently able to brake the movement of the cable towards the drum. This feature of the invention enables winding of the cable on the drum without the cable being tangled thereon. According to another embodiment of the invention said means able to transfer power to said at least one member is able to influence said at least one member to move the elongated element in the endless loop in such a direction that the cable is fed from the drum by friction to the elongated element in said part of the endless loop. This feature enables easy and smooth feeding of the cable from the drum, which cables in normal winches of the type described in the introduction are very heavy and complicated to handle.

[0011] According to another embodiment of the invention the winch comprises a control unit configured to control the operation of said means. Said control unit enables uncomplicated and efficient control of said means and consequently of the influence of the element on the movement of the cable.

[0012] According to another embodiment of the invention the winch comprises at least one spring member configured to establish pressure of said elongated element to the cable, preferably controllable by means configured to control the pressure of said elongated element to the cable to switch between at least two modes, a first high-pressure mode and a second low-pressure mode. Said spring member is used to, in said high-pressure mode, enable high friction force between said element and the cable, for better possibility of said element to influence the movement of the cable. Said means configured to control the pressure of said element to the cable enables control of the pressure according to the circumstances.

[0013] According to another embodiment of the invention said means able to transfer power to said at least one member comprises motor means, preferably hydraulic motor means, preferably operable by motor means configured to drive the drum. With motor means said member and consequently said elongated element is easy and effective to drive and control. Hydraulic motor means are effective for the driving of winches and are commonly used thereto. Therefore, with hydraulic motor means to transfer power to said at least one member it is uncomplicated to connect said motor means with the motor means to drive the drum of any hydraulic motorized winch for easy operation and control of said power transferring motor means.

[0014] According to another embodiment of the invention said at least one member in engagement with said elongated element is one of said diverting members. Transferring power to one of said diverting members is an uncomplicated and effective way to influence said elongated element and consequently the ability for this to influence the movement of the cable.

[0015] According to another embodiment of the invention at least one of said diverting members is provided with engagement means engaging engagement means of said elongated element. Engaging connection between said at least one diverting member and said elongated element enables easy control and efficient use of said element.

[0016] According to another embodiment of the invention said elongated element is provided with a plurality of segments connected to each other and at least partially movable relative to each other, said elongated element being preferably a chain. An elongated element provided with movable segments provides advantages such as the feasibility to form each segment out of a hard and rigid material without restricting the bendability of the element. A chain is a specially suitable form of an hard element still being flexible.

[0017] According to another embodiment of the invention said elongated element is provided with friction means configured to bear against the cable along said part of the loop. Said friction means provides the possibility of high friction force between said element and the cable and increases the ability of said element to influence the movement of the cable without sliding with respect thereto.

[0018] According to another embodiment of the invention at least one third, preferably a majority, of said segments are provided with friction means. One third of said segments being provided with friction means ensures a possibility to obtain sufficient influence of said element on the cable. A majority of said segments being provided with friction means further increases the maximum possible influence of said element on the movement of the cable.

[0019] According to another embodiment of the invention the winch comprises cable guiding means, preferably arranged on both sides of said part of the loop along the cable, so as to guide the cable in a suitable position along said part of the loop. Said cable guiding means ensures good contact between said elongated element and the cable so as to ensure optimal ability of said element to influence the cable.

[0020] According to another embodiment of the invention said elongated element and said at least two diverting members are arranged within a casing, preferably formed by at least two parts removable from each other, so as to allow removal of a second part from a first part for maintenance operations. Said casing protects said elongated element and said at least two diverting members from being dirty and/or damaged. The possibility to remove the casing parts from each other allows easy maintenance work of said element and said diverting members, such as regularly cleaning or replacement of those.

[0021] According to another embodiment of the invention the winch comprises pressure means arranged at the opposite side of said part of the loop relative to the cable along said part of the loop, so as to establish pressure of said elongated element to the cable in said part of the loop. Said pressure means provides the ability to reach optimal utilization of said elongated element.

[0022] According to another embodiment of the invention the winch comprises a further elongated element extending in an endless loop around at least two diverting members and configured to bear against the cable at a distance to the drum so as to by friction to the cable move in said endless loop upon movement of the cable along a part of said loop. Said further elongated element increases the ability to efficiently influence the movement of the cable.

[0023] According to another embodiment of the invention the winch comprises means configured to be able to transfer power to a member in engagement with said further element so as to affect the ability of said further element to move in said endless loop and consequently the cable to move along said part of the loop. The ability to influence the movement of the cable increases with two elements bearing on the cable and power transferred on both elements through a said member in engagement therewith.

[0024] According to another embodiment of the invention said means comprising motor means are configured to be able to transfer power to at least two members, at least two elongated elements being motorized drivable by said means through said at least two members. Said at least two elongated elements being motorized drivable by said means further increases the ability to control the cable.

[0025] According to another embodiment of the invention the winch comprises two said elongated elements being formed and/or operating equally. Two equally formed and/or operating elements ensures uncomplicated and effective operation of said elements.

[0026] Further advantages as well as advantageous features of the invention will appear from the following description of embodiments of the invention.

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0027] With reference to the appended drawings, below follows a specific description of an embodiment of the invention cited as an example.

[0028] In the drawings:

Fig 1 is a simplified side-elevation view of a winch according to an embodiment of the invention in operation,

Fig 2 is an enlarged perspective view of a part of the winch shown in Fig 1, and

Fig 3 is a further enlarged view of an arrangement for controlling the cable of the winch shown in Fig 1, with the second part of the casing being removed.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0029] A winch according to an embodiment of the invention is illustrated in the appended Figures 1-3 and will now be described while at the same time making reference to all these Figures. The winch 1 is arranged at a telescopic boom 2 at a tow truck 3 and comprises a drum 4 connected to a hydraulic motor 5 to drive the drum to rotate and a cable 6 configured to be wound around the drum and extending on the upper side of the telescopic boom from the drum towards and through a cable guiding arrangement 7 at the very end of said boom. An arrangement 8 for controlling the cable 6 is arranged at the upper side of the boom 2 between the drum 4 and the cable guiding arrangement 7, and is also guiding the cable.

[0030] The arrangement 8 is provided with a casing 9 formed by two main parts 10, 11, a first part 10 fixedly arranged by for example welding at the telescopic boom 2 and a second part 11 movably attached to said first part by securing means 12, such as screws, to enable uncomplicated removal of said second part of the casing from said first part for maintenance operations, such as cleaning or replacement of components arranged inside the casing.

[0031] Two similar assemblies 13, 14, each comprising an elongated element 15, 16 extending in an endless loop around two diverting members 17-20, are arranged within the casing 9 at opposite sides of the cable 6. Said elongated element is in each assembly a chain provided with segments 21 made of a hard material, such as steel, and movably connected to each other. Each segment is provided with friction means 22 of a material with a high coefficient of friction with respect to the cable, such as rubber, and configured to bear against the cable at a part 23a, 23b of said endless loop so as to provide the ability for the element 15, 16 to move in said endless loop by friction to the cable 6 when the cable is moving along said part of the loop. A pressure member 24, 25 is arranged at the other side of the respective element in said part of the loop relative to the cable to establish pressure of the element and consequently the friction means 22 in said part 23a, 23b of the loop to the cable 6.

[0032] Said diverting members 17-20 are in this embodiment of the invention gear wheels configured to engagingly connect to the respective element 15, 16. One of said diverting members in each assembly 13, 14, such as the members 17 and 19, is drivable by a respective hydraulic motor 26, 27 arranged partly outside the casing 9 on said second part 11 thereof. The hydraulic motors arranged at said arrangement 8 for controlling the cable 6 are provided with a hydraulic block 28 connected to a hydraulic block 29 arranged at the hydraulic motor 5 to drive the drum 4 by means of a hydraulic hose 30 so as to transfer power to said members 17, 19 by means of the hydraulic motor to drive the drum. A valve block 31 is arranged at the hydraulic motor to drive the drum, for control of all said hydraulic motors 5, 26, 27.

[0033] This constitutes a very simple way to connect said hydraulic motors 26, 27 for transfer of power to said element 15, 16 to an hydraulic system already existing, so that existing winches may easily be modified for providing a winch according to the present invention.

[0034] The assembly 14 located in the lower part of the arrangement 8 as shown in Fig 3 is fixedly arranged at said first part 10 of the casing 9 while the assembly 13 located in the upper part of the arrangement as shown in this Figure is movably arranged inside the casing by means of spring members 32, 33 configured to establish pressure of the elongated element 15 of said assembly to the cable 6 and the pretension of these spring members are controllable by means 34, 35, such as screws, so as to control the pressure of said elongated element to the cable to switch between at least two modes, a first high-pressure mode and a second low-pressure mode.

[0035] Cable guiding means 36, 37 are also arranged inside said casing 9 on both sides of said part 23a, 23b of the loop along the cable 6 so as to guide the cable in a suitable position between the friction means 22 of the element 15, 16 of each assembly 13, 14 along said part of the loop.

[0036] It is shown in Fig 1 how the winch 1 according to the embodiment of the invention described can be used to drag a vehicle 38 out of a ditch. The operation and features of the winch for this use is described below.

[0037] When the tow truck 3 is parked in front of the vehicle to be dragged out of the ditch the cable 6 has to be unwound from the drum 4 to provide such a length of free cable 39 that a hook 40 arranged at the end of the cable reaches the front of the vehicle in the ditch. The driver of the tow truck pulls a lever 41 on the valve block 31 to switch the winch to feeding-mode. The drum is decoupled and the hydraulic motor 5 to drive the drum activates the hydraulic motors 26, 27 at the arrangement 8 for controlling the cable via the hydraulic hose 30. The hydraulic motors transfer power to one 17, 19 of the two diverting members 17-20 in engagement with respective element 15, 16 to move each element in such a direction that the part of the elements being in said part 23a, 23b of the loops moves in the direction away from the drum 4. The pressure members 24, 25 and the spring members 32, 33 provides a high possible friction force of the friction means 22 to the cable 6 and the cable may by this be fed from the drum by the power transferred to the members 17, 19 from said hydraulic motors 26, 27.

[0038] When the length of free cable 39 needed is reached the driver stops the feeding of the cable from the drum, either by stopping the driving of the members 17, 19 or by releasing the pressure of one element 15 to the cable by controlling the spring members by the means 34, 35 for controlling the spring members.

[0039] The driver then connects the hook 40 of the cable 6 to the front of the vehicle 38 in the ditch and switches the winch 1 to pulling-mode with the valve block 31. The drum 4 starts to wind the cable thereon and the vehicle is consequently dragged out of the ditch. When the winch is in pulling-mode the elements 15, 16 are either running in their loops along with the cable through friction of the friction means 22 thereto or the winch is in a mode in which the pressure of one element 15 to the cable is released or kept low by the spring members 32, 33 via the means 34, 35 for controlling the spring members.

[0040] When the vehicle 38 is out of the ditch the hook 40 of the cable 6 is released therefrom and the cable has to be wound on the drum 4 so that the tow truck 3 can drive to another location. The driver do then by the valve block 31 switch the winch 1 to winding-mode and the hydraulic motor 5 at the drum starts to make the drum rotate so that the cable is being wound thereon. The spring members 32, 33 exerts pressure on one 15 of the elements and the cable is being urged between the friction means 22 of the two elements 15, 16 along their said part 23a, 23b of the loops. The hydraulic motors 26, 27 at said arrangement 8 for controlling the cable 6 impedes movement of the elements in said part of the loops in the same direction as the cable moves along said part of the loops by acting upon the members 17, 19 so that the movement of the cable towards the drum 4 is controllably braked. By the braking force applied on the cable this is being strained and can be wound on the drum without being tangled thereon. The braking force of said arrangement can vary between hundreds of N and thousands of N according to for example the weight of the cable 6.

[0041] The invention is of course not in any way restricted to the embodiments thereof described above, but many possibilities to modifications thereof will be apparent to a person with ordinary skill in the art without departing from the scope of the invention as defined in the appended claims.

[0042] The engagement means being gear teeth according to an embodiment of the invention may be any type of engagement means, such as for instance sticks, engaging engagement means of said elongated element being for instance holes in a chain.

[0043] The further elongated element may be any one of the elements shown in Fig 3 or even another elongated element.

[0044] The spring force controlling means being screws in the embodiment of the invention described may of course also be other mechanical means suitable for controlling spring members and even non-manually controlled means.

[0045] The spring members being mechanical springs may also be for example hydraulic cylinders or electrically controlled pumps.

[0046] The control unit being a valve block in the embodiment described may be any type of control unit, such as a wireless remote control or an electrical control switch.

[0047] The members being gear wheels in the embodiment described may also be of another type of members with the ability to engagingly connect to the respective elongated element. Each element may be engagingly connected to more than two members, such as for instance three, five, ten or even more.

[0048] The means configured to transfer power to said members in engagement with the respective elongated element may obtain this transfer power by acting directly upon said members or indirectly by acting upon for instance an axle connecting to said members, and said directly or indirectly acting may be of any type, such as mechanical, by medium pressure etc.

[0049] The members through which power is transferred to the elements from the power transferring means may be other members than said diverting members, such as for instance gear wheels arranged outside of said endless loops.

[0050] The choice of material of parts of the winch according to the embodiment of the invention suggested is not restricting the invention thereto, but the material choices of these parts could vary in a wide range according to the circumstances.

[0051] The concept - driven drum - is including all types of drums that can be used in such winches described in the introduction which are not manually powered drums. Such driven drums may be driven by one or more motors, pressure pumps, mechanical devices or other driving means.

[0052] "Cable" as used in this disclosure is to be interpreted broadly and shall cover all objects acting as a cable and not be restricted to a particular type of cable, but may accordingly be any type of cable-like element suitable for use in such winches described, such as a steel-cable, a rope, a wire formed of a synthetic material or another type of cable-like element.

[0053] The diameter of the cable to be used in a winch according to the invention should be at least 10 millimetres.

[0054] In a possible embodiment of the invention said elongated element is provided with resilient friction means, such as parts of elastic material arranged on a chain, and is arranged in such a way, that the cable is movably fixed along said part of the loop between said resilient friction means and the counter support member or the further elongated element arranged at the opposite side of the cable relative the elongated element in said part of the loop, by a constant pressure of said resilient friction means in said part of the loop to the cable along said part of the loop.

[0055] In the case of having the winch arranged on a vehicle it may as an alternative be arranged on a block directly upon the chassis of the vehicle instead of on a boom.

Claims

1. A winch (1) comprising a driven drum (4), a cable (6) configured to be wound around the drum (4) and an elongated element (15,16) extending in an endless loop around at least two diverting members (17-20) and configured to bear against the cable (6) at a distance to the drum (4) so as to by friction to the cable (6) move in said endless loop upon movement of the cable (6) along a part (23a,23b) of said loop, characterized in that the winch (1) comprises means (26,27) configured to be able to transfer power to at least one member (17-20) in engagement with the elongated element (15,16) so as to affect the ability of said element (15,16) to move in the endless loop and consequently the cable (6) to move along said part (23a,23b) of the loop.

2. A winch (1) according to claim 1, characterized in that at least one counter support member is arranged at the opposite side of the cable (6) relative to the elongated element (15,16) in said part (23a,23b) of the loop, so as to there urge the cable (6) against said elongated element (15,16) for movably fixing the cable (6) between this element (15,16) and the counter support member.

3. A winch (1) according to claim 1 or 2, characterized in that said means (26,27) able to transfer power to said at least one member (17-20) is able to impede a movement of the element (15,16) in said part (23a,23b) of the loop in the same direction as the cable (6) move along said part (23a,23b) of the loop when the cable (6) is being wound on the drum (4) and said means (26,27) is consequently able to brake the movement of the cable (6) towards the drum (4).

4. A winch (1) according to any of the preceding claims, characterized in that said means (26,27) able to transfer power to said at least one member (17-20) is able to influence said at least one member (17-20) to move the elongated element (15,16) in the endless loop in such a direction that the cable (6) is fed from the drum (4) by friction to the elongated element (15,16) in said part (23a,23b) of the endless loop.

5. A winch (1) according to any of the preceding claims, characterized in that the winch (1) comprises a control unit (31) configured to control the operation of said means (26,27).

6. A winch (1) according to any of the preceding claims, characterized in that the winch (1) comprises at least one spring member (32,33) configured to establish pressure of said elongated element (15) to the cable (6), preferably controllable by means (34,35) configured to control the pressure of said elongated element (15) to the cable (6) to switch between at least two modes, a first high-pressure mode and a second low-pressure mode.

7. A winch (1) according to any of the preceding claims, characterized in that said means (26,27) able to transfer power to said at least one member (17-20) comprises motor means, preferably hydraulic motor means, preferably operable by motor means (5) configured to drive the drum (4).

8. A winch (1) according to any of the preceding claims, characterized in that said at least one member (17-20) in engagement with said elongated element (15,16) is one of said diverting members (17-20).

9. A winch (1) according to any of the preceding claims, characterized in that at least one of said diverting members (17-20) is provided with engagement means (42) engaging engagement means (43) of said elongated element (15,16).

10. A winch (1) according to any of the preceding claims, characterized in that said elongated element (15,16) is provided with a plurality of segments (21) connected to each other and at least partially movable relative to each other, said elongated element (15,16) being preferably a chain.

11. A winch (1) according to any of the preceding claims, characterized in that said elongated element (15,16) is provided with friction means (22) configured to bear against the cable (6) along said part (23a,23b) of the loop.

12. A winch (1) according to claim 10 and 11, characterized in that at least one third, preferably a majority, of said segments (21) are provided with friction means (22).

13. A winch (1) according to any of the preceding claims, characterized in that the winch (1) comprises cable guiding means (36,37), preferably arranged on both sides of said part (23a,23b) of the loop along the cable (6), so as to guide the cable (6) in a suitable position along said part (23a,23b) of the loop.

14. A winch (1) according to any of the preceding claims, characterized in that said elongated element (15,16) and said diverting members (17-20) are arranged within a casing (9), preferably formed by at least two parts (10,11) removable from each other, so as to allow removal of a second part (11) from a first part (10) for maintenance operations.

15. A winch (1) according to any of the preceding claims, characterized in that the winch (1) comprises pressure means (24,25) arranged at the opposite side of said part (23a,23b) of the loop relative to the cable (6), so as to establish pressure of said elongated element (15,16) to the cable (6) in said part (23a,23b) of the loop.

16. A winch (1) according to any of the preceding claims, characterized in that the winch (1) comprises a further elongated element (15,16) extending in an endless loop around at least two diverting members (17-20) and configured to bear against the cable (6) at a distance to the drum (4) so as to by friction to the cable (6) move in said endless loop upon movement of the cable (6) along a part (23a,23b) of said loop.

17. A winch (1) according to claim 16, characterized in that the winch (1) comprises means (26,27) configured to be able to transfer power to a member (17-20) in engagement with said further element (15,16) so as to affect the ability of said further element (15,16) to move in said endless loop and consequently the cable (6) to move along said part (23a,23b) of the loop.

18. A winch (1) according to claim 7 and 17, characterized in that said means (26,27) comprising motor means are configured to be able to transfer power to at least two members (17-20), at least two elongated elements (15,16) being motorized drivable by said means (26,27) through said at least two members (17-20).

19. A winch (1) according to any of the preceding claims, characterized in that the winch (1) comprises two said elongated elements (15,16) being formed and/or operating equally.

Drawing