A WINCH

Abstract: A winch comprises a drive pulley (13) for a lifting cable (14) which is rotatable in optional direction by means of a driving motor (10), and a guide means (17) for the lifting cable (14) which is connected to the drive pulley (13) through a slip coupling (26, 27, 28) and arranged for limited rotation, the lifting cable being movable by said guide means between an engagement position, in which it is located in drive engagement with the drive pulley (13), and a release position, in which it is located out of drive engagement with the drive pulley (13) and is supported by an alternative supporting means (18) for the lifting cable (14), over which the lifting cable (14) may be let out without being driven from the drive motor (10). The guide means (17) is arranged to move the lifting cable (14) between the engagement position and an axially displaced release position in which the lifting cable (14) is supported axially at the side of the drive pulley (13) by the alternative supporting means (18).

Description: A winch The present invention relates to a winch which in the first place is intended to be used as an anchor winch on sailing boats or yachts and on motor boats but which may be utilized also for various other purposes. More particularly, the invention relates to a winch of the kind comprising a drive pulley for a lifting cable which is rotatable at choice in one direction or the other by means by a driving motor, and a guide means for the lifting cable which is connected to the drive pulley through a slip coupling and arranged for limited rotation around the rotary axis of the drive pulley, the lifting cable being movable by said guide means between an engage¬ ment position, in which it extends in a bight around the drive pulley and is located in drive engagement there- with, and a release position, in which it is located out of drive engagement with the drive pulley and extends in a bight around an alternative supporting means for the lifting cable over which the lifting cable may be let out without being driven from the drive motor. A winch of said kind is previously known through EP-B 0 284 581. In this known winch, the guide means is formed by a member having the shape of a sector of a cylinder and mounted for limited rotation thereof, said member also forming said alternative supporting means. This member is located radially outside the drive pulley and axially in front of the latter and it is arranged to be swung around the rotary axis of the drive pulley between an inactive position below the drive pulley and an active position in which it is located above the drive pulley and can hold the lifting cable in a release posi¬ tion in which said cable is held lifted up in a radial direction from the drive pulley. In practice, this con¬ struction of the known winch is unfavourable in several respects. Firstly, the two parts of the lifting cable cannot be permitted to extend substantially parallel to each other from the drive pulley or said sector- shaped member. On the contrary, they must form a con¬ siderable angle with each other. However, even if the lifting cable is arranged in this manner, it may happen that said cable will get hitched to the drive pulley and get jammed between the latter and said member. Naturally, this is totally unacceptable as it may result in very serious damages and accidents. The invention has for its purpose to provide an improved winch of the kind above specified which elimi¬ nates the above described disadvantages as well as other disadvantages of the known winch. The winch according to the invention proposed for the above purpose is primarly characterized in that the guide means is arranged to move the lifting cable between the engagement position and an axially displaced release position in which the lifting cable is supported axially at the side of the drive pulley by the alternative supporting means. As a consequence of the fact that, in the winch according to the invention, in the release position, the lifting cable is axially displaced from the drive pulley, the above described disadvantages of the known device are totally avoided. Moreover, the alternative supporting means may be designed so as to be capable of supporting the lifting cable on an arc-shaped curved supporting surface extending through an angle of 180° instead of through a maximum angle of only about 90° as is the case in the known device. The lastmentioned fact means that the lifting cable need not be subjected to any abrupt change in its direction at the ends of said supporting surface. Also in the winch according to the invention, the alternative supporting means for the lifting cable may be formed by the guide means or a member rigidly connected thereto. However, the alternative supporting means may in¬ stead preferably consist of a separate supporting member for the lifting cable located in relation to the drive pulley at the opposite side of the guide means. This supporting member may consist of a stationary member. However, preferably, it may instead consist of a sup¬ porting wheel for the lifting cable mounted on the driving shaft for the drive pulley. Said supporting wheel may either be rigidly mounted on said shaft for rotation in unison therewith or it may be rotatably journalled on said shaft. In all three cases, the supporting member may be arranged to exert a limited braking action on the lifting cable when the lifting cable is let out over the supporting member. Hereby, it is possible to prevent the lifting cable from being let out in a totally uncon¬ trolled manner over the supporting member as a result of its own weight. If the winch constitutes an anchor winch and the lifting cable consists of an anchor cable carrying an anchor, said braking action may be selected in such a manner that during anchoring, the movement of the cable will be braked as soon as the anchor ceases to exert a pulling force on the cable. If the supporting member consists of a stationary member or a member ridigly mounted on the driving shaft for the drive pulley and rotatable in unison with said shaft, said braking action may be achieved by providing the supporting member with a supporting surface for the lifting cable consisting of a friction material. If the supporting member consists of a supporting wheel rotatably mounted on the driving shaft for the drive pulley, said braking action may instead be obtained by arranging the supporting wheel to engage the lifting cable and to be brought into rotation by the lifting cable when the latter is let out but simultaneously to be subjected to a limited braking action from braking means contacting the supporting wheel . According to the invention, the guide means may suitably consist of a generally circular disc-shaped member, comprising a portion, projecting radially out- side the drive pulley and having two cut out tongues which are bent in mutually opposite axial directions and extend towards each other as seen in the circum¬ ferential direction and which define a passage opening for the lifting cable between their free ends. Morevoer, the alternative supporting means may preferably have a conically tapered supporting surface for the lifting cable tapering off in direction towards the guide means, in order hereby to facilitate a trasfer of the lifting cable from said supporting means to the drive pulley by the guide means. Below the invention will be further described with reference to the accompanying drawings, in which:- Figures 1 and 2 are perspective views of a winch according to the invention, showing the winch in two different states, Figure 3 is a side elevation of the winch, showing it in a third state, Figures 4, 5 and 6 are front views of the winch, showing it in three different states, Figure 7 is a partial view in longitudinal section of the winch and Figure 8 is a corresponding partial view in longi¬ tudinal section of a winch of a slightly modified con¬ struction. The winch shown in Figures 1 - 7 comprises a re¬ versible electric driving motor 10 and a self-locking reduction gear 11 provided with a projecting, at least approximately horizontal driving shaft 12 for a drive pulley 13 for a lifting cable consisting of a chain 14. in order to facilitate an effective drive engagement between drive pulley 13 and chain 14, the drive pulley is provided with a central peripheral groove 13A and two peripheral rows of wedge-shaped projections 13B lo¬ cated at opposite sides of said groove. Drive pulley 13 is non-rotatably connected to driving shaft 12 by means of a key 15 (Figure 7) which extends into a keyway 16 in the drive pulley. Hereby, drive pulley 12 may be rotated at choice in one direction or the other by being driven from motor 10 through gear 11. Reference numeral 17 designates a guide means for chain 14 which is rotatably mounted on driving shaft 12 and formed as a disc-shaped member. This guide means serves to facilitate a movement of chain 14 between an engagement position, shown in Figures 1 and 4 and in which the chain extends in a bight around drive pulley 13 and is in drive engagement therewith, and a release position, shown in Figures 3 and 6 and in which the chain is located out of drive engagement with the drive pulley and extends in a bight around a supporting wheel 18 serving as an alternative supporting means for the chain. Suppor- ting wheel 18 is located in relation to drive pulley 13 at the opposite side of guide means 17 and it is non- rotatably connected to driving shaft 12 by means of a key 20 which extends into a keyway 19 (Figure 7) in the supporting wheel. Furthermore, supporting wheel 18 is kept in an axially fixed position on driving shaft 12 by being held between a shoulder 21 of said shaft and a locking ring 22 which is received in a peripheral groove in the driving shaft. Guide means 17 comprises a portion 17A projecting radially outside drive pulley 13 and provided with two cut out tongues 23 and 24 which are arcuately bent in mutually opposite axial directions. These two tongues extend in circumferential direction towards each other and define between their free ends a passage opening 25 for chain 14. Guide means 17 is slip coupled to drive pulley 13 by means of a slip coupling. This slip coupling com¬ prises two thin discs 26 and 27 of a plastic material with suitable friction properties, located at opposite sides of the central portion of guide means 17, and a cup spring 28. This cup spring rests with an inner por¬ tion thereof against a shoulder 29 on driving shaft 12, and, by means of outer peripheral portions thereof, it pushes the two discs 26 and 27 and the intermediate guide means 17 in axial direction towards the adjacent side of drive pulley 13. Reference numeral 30 designates a nut which is mounted on a threaded outer end portion of driving shaft 12 and by means of which the contact pressure of the slip coupling may be adjusted. Guide means 17 cannot be rotated unlimitedly around driving shaft 12 but only within a limited angle range of about 310°. This limitation of the possible rotation of the guide means is obtained by means of a sector-shaped projection 31, which extends in a radial outward direction from guide means 17, and a co-operating fixed stop 32. In the drawings, this stop has been shown as consisting of a rod which is secured to the casing of reduction gear 11 and against which projection 31 may be brought to rest with one or the other of its two opposite radially extending edges 31A and 31B. In Figures 1 and 4, guide means 17 has been shown in one of its two end positions, while in Figures 3 and 6, it has been shown in its other end position. In both cases, tongues 23 and 24 are located in positions in which they leave chain 14 uninfluenced by them. Below the manner of operation of the above-described winch will be explained in greater detail with reference to a preferred field of use, namely the use of the winch as an anchor winch on a motor boat or a sailing boat or yacht. In this case, one part 14' of chain 14 is assumed to be connected to an anchor, not shown, which may subject said part to a downwardly directed pulling force, while the other part 14" of the chain is assumed to extend downwards into a chain box or the like, not shown. If driving motor 10 is inoperative and the chain is simultaneously in its engagement position shown in Figures 1 and 4 and in which it is supported by drive pulley 13 and located in engagement therewith, the chain will be held firmly in a stationary position by the winch. When drive pulley 13 is then brought into rotation in a clockwise direction according to Figure 4 by starting the driving motor 10, the anchor connected to chain part 14' will be heaved up and chain part 14" will simultaneous¬ ly be fed down into the chain box. When the anchor has been heaved up, motor 10 may be stopped either manually or automatically by utilizing suitable sensing means. The winch then keeps the anchor in its weighed position as a result of the self-locking function of reduction gear 11. However, if desired, the anchor may be secured in this position by suitable separate locking means. When heaving up the anchor as above described, guide means 17 will be uninfluenced and remain in its position shown in Figures 1 and 4. When the anchor is to be dropped, driving motor 10 is started and brought to rotate for a short period of time in a direction opposite to the above-mentioned rotary direction. Drive pulley 13 will then be rotated in a counter-clockwise direction according to Figure 4 and rotate guide means 17, which is slip coupled thereto, from the position shown in Figure 4 to the position shown in Figure 6 while passing the intermediate position shown in Figure 5. During this rotation of guide means 17, tongue 23, which projects radially outside drive pulley 13 and, in the starting position according to Figure 4, is located between the two chain parts 14' and 14", will be moved into contact with chain 14 at its part 14" and then successively bring the bight of the chain previously located in engagement with drive pulley 13 out of engage¬ ment with the drive pulley and transfer it to supporting wheel 18, on which said bight of the chain will rest along its entire length when guide means 17 reaches the position shown in Figure 6. As soon as the guide means has reached this position, the driving motor may be stopped. Chain 14 may then be let out over supporting wheel 18 by the action of the pulling force exerted by the anchor without being driven from the driving motor 10. In order to make it possible for supporting wheel 18 to exert a certain braking action on chain 14 and hereby to prevent a continued letting out of the chain under the action of its own weight when the anchor has reached the current anchorage ground, the supporting wheel as a whole or at least an outer peripheral portion thereof may consist of a rubber material or any other suitable material offering a relatively high friction. When the desired length of chain 14 has been let out over supporting wheel 18, the chain may be brought back into engagement with drive pulley 13 by putting driving motor 10 into operation for a short period of time in order to rotate guide means 17 in a clockwise direction from the position according to Figure 6 to the position according to Figure 4. This retransfer of the chain from supporting wheel 18 to the drive pulley is effected by tongue 24, which projects radially in front of the supporting wheel, and is facilitated by the fact that the supporting wheel is provided with a frusto-conical peripheral supporting surface for chain 14 tapering in direction towards guide means 17. Figure 8 shows a winch according to a modified embodiment of the invention. This winch differs from the winch according to Figures 1 to 7 in that supporting wheel 18' is rotatably mounted on driving shaft 12 instea of non-rotatably connected thereto. Furthermore, supporti wheel 18' is provided with a row of wedge-shaped peri¬ pheral projections 33 which may be brought into engage¬ ment with chain 14 to ensure that supporting wheel 18' will be brought into rotation by the chain when the latter is let out over the supporting wheel. Hereby, it is possible by means of suitable sensing and indication means, not shown, to provide an indication of the chain length let out over the supporting wheel. In order to make it possible, also at the winch according to Figure 8, to obtain a certain braking of chain 14 when letting out the chain over supporting wheel 18', the supporting wheel may be arranged to be subjected to a limited braking action from braking means provided in contact therewith and consisting for instance of a brake disc 34, which is non-rotatably mounted on the driving shaft, and a cup spring 35, provided in con¬ tact with said brake disc. The invention is not restricted to the embodiments above described and shown in the drawings. Instead, many other embodiments are feasible within the scope of the invention. For instance, it could be mentioned that the alternative supporting means for the lifting cable may consist of a stationary member mounted on a fixed portion of the winch. Moreover, the winch may be designed for use with another type of lifting cable than a chain, for instance a lifting cable consisting of a rope.

Claims: Cl a ims 1. A winch, comprising a drive pulley (13) for a lifting cable (14) which is rotatable at choice in one direction or the other by means of a driving motor (10), and a guide means (17) for the lifting cable which is connected to the drive pulley through a slip coupling (26, 27, 28) and arranged for limited rotation around the rotary axis of the drive pulley, the lifting cable being movable by said guide means between an engagement position, in which it extends in a bight around the drive pulley (13) and is located in drive engagement therewith, and a release position, in which it is located out of drive engagement with the drive pulley and extends in a bight around an alternative supporting means (18; 18') for the lifting cable (14) over which the lifting cable may be let out without being driven from the drive motor (10), characterized in that the guide means (17) is arranged to move the lifting cable (14) between the engagement position and an axially displaced release position in which the lifting cable (14) is supported axially at the side of the drive pulley (13) by the alternative supporting means (18; 18'). 2. A winch according to claim 1, characterized in that the alternative supporting means consists of a separate supporting member (18; 18' ) for the lifting cable (14), located in relation to the drive pulley (13) at the opposite side of the guide means (17). 3. A winch according to claim 2, characterized in that said supporting member (18) consists of a stationary member. 4. A winch according to claim 2, characterized in that said supporting member consists of a supporting wheel (18; 18' ) for the lifting cable (14) mounted on the driving shaft (12) for the drive pulley (13). 5. A winch according to claim 4, characterized in that said supporting wheel (18) is ridigly mounted on the driving shaft (12) for the drive pulley (13) for rotation in unison therewith. 6. A winch according to claim 4, characterized in that said supporting wheel (18') is rotatably journalled on the driving shaft (12) for the drive pulley (13). 7. A winch according to any of claims 2 to 6, characterized in that said supporting member (18; 18' ) is arranged to exert a limited braking action on the lifting cable (14) when the lifting cable is let out over the supporting member. 8. A winch according to claim 3 or 5 and claim 7, characterized in that the supporting member (18) is pro¬ vided with a supporting surface for the lifting cable (14) consisting of a friction material. 9. A winch according to claims 6 and 7, characterized in that the supporting wheel (18') is arranged to engage the lifting cable (14) and to be brought into rotation by the lifting cable when the latter is let out but simul- taneously to be subjected to a limited braking action from braking means (33, 34) contacting the supporting wheel . 10. A winch according to any of the preceding claims, characterized in that the guide means (17) consists of a generally circular disc-shaped member, comprising a portion (17A), projecting radially outside the drive pulley and having two cut out tongues (23, 24) which are bent in mutually opposite axial directions and extend towards each other as seen in the circumferential direc- tion and which define a passage opening (25) for the lifting cable (14) between their free ends. 11. A winch according to claim 10, characterized in that the alternative supporting means (18; 18' ) has a conically tapered supporting surface for the lifting cable (14) tapering off in direction towards the guide means (17).

Inventors: LUNDSTROEM OLOF ROLAND, LUNDSTROEM, OLOF, ROLAND
Applicants: LUNDSTROEM OLOF ROLAND, LUNDSTROEM, OLOF, ROLAND
Application year: 1996
Main classification: B66D1
IPC codes: B63B21, B66D1