Abstract:
A winch drive comprising a portable power tool having a bit ( 4 ) shaped to fit the drive socket ( 11 ) at the top of a winch ( 12 ). The power tool includes a self-tailing device ( 14 ) and is preferably battery driven.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a winch drive, particularly for a boat or yacht. 
     2. Description of Related Art 
     Winches are commonly used on yachts or other boats for tensioning or pulling running rigg, usually a line wound around the drum of the winch. The winch is normally rotated manually, and a standard shaped socket is provided in the top of the winch into which the correspondingly shaped end of a handle is inserted. Rotation of the handle rotates the winch and tensions the line. Manually rotating the winch can be difficult work, particularly under certain conditions, eg with heavy load and/or in bad weather. 
     It is known to power some forms of winch by means of an electric motor situated below deck immediately under the winch. Such a motor takes up valuable under-deck space, and can be difficult to access for servicing. 
     SUMMARY OF THE INVENTION 
     An object of this invention is to provide a winch drive, which is simple to operate and does not occupy under-deck space. 
     The invention provides a winch drive as claimed in claim  1 . 
     Although the shaped bit may be retractable, it is preferably integral with the power tool. 
     Preferably, the power tool is battery driven, and the batteries are rechargeable. The batteries may be accommodated within a handle of the power tool or in a separate detachable battery housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described with reference to the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a first embodiment of a winch drive in accordance with the invention but not showing the self-tailing device, 
     FIG. 2 is a perspective view of a second embodiment of a winch drive in accordance with the invention but not showing the self-tailing device, 
     FIG. 3 is a plan view of a winch showing the standard socket for engagement by the shaped end of a winch handle, 
     FIGS. 4A, B and C are underside views of shaped bits for the power drives of FIGS. 1 and 2, and 
     FIG. 5 is a side view of the winch drive of FIG.  1  and showing the self-tailing device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1 a winch power drive comprises a body  1  housing an electric motor  2  drivingly connected via a shaft  3  to a shaped bit  4 . 
     The body  1  also houses one or more batteries  5 , which are preferably rechargeable via a connection terminal  6 . The portion  7  of the body  1  housing the battery  5  may be detachable for ease of recharging. The body  1  may be provided with finger-shaped recesses  1 ′ to facilitate gripping by the operator. 
     The winch drive has a handle  8 , which may be detachable, to prevent rotation of the body  1  while the shaped bit  4  is driven by the electric motor  2 . 
     The body  1  also has a forward and reverse switch  9  as well as a high/low speed control button  10 . 
     The self-tailing device is described with reference to FIG.  5 . 
     The winch drive in FIG. 2 is similar to that shown in FIG. 1, but has a different shape. As shown in FIGS. 1 and 2, the battery or batteries  5  may be contained either in a detachable battery housing  7  or in the handle  8 . 
     The bit  4  of the winch drive is shaped to engage the standard socket at the top of a winch  12 , as shown in FIG.  3 . The bit  4  may have the shape as shown in FIG. 4A,  4 B or  4 C to fit snugly into the socket  11 . 
     In accordance with the invention, and as shown in FIG. 5, the winch drive has a self-tailing device  14 . This comprises two spaced, annular-shaped discs  15 ,  15 ′, one of which (here  15 ′) is resiliently movable away from the other disc against the bias of a spring (not shown). The self-tailing device  14  also has a line guide  16 . 
     In use the winch drive is placed on top of the winch so that the bit  4  engages the socket  11  as shown in FIG.  5 . The line  13  is wound around the winch  12  and the end  17  of the line is wound around the line guide  16  and drawn between the discs  15 ,  15 ′ against the bias of the spring (not shown). Thus, the end  17  of the line  13  is firmly held by the self-tailing device  14  to free both hands for operation of the winch drive. 
     The operator holds the body  1  of the winch drive and the handle securely and switches on the electric motor to drive the winch to tension the rope  13  to the required degree. 
     The winch can be driven at different speeds or torque by operation of the speed and/or torque control button  10 , and also by operation of the forward and reverse switch  9 . The standard construction of a boat winch  12  is such that when the socket  11  is rotated in one direction the winch rotates at one speed, whereas when the socket is rotated in the opposite direction the winch rotates in the same direction as previously, but at a different speed. 
     When the line is to be released, the end  17  is merely pulled out from between the discs  15 ,  15 ′ and unwound from the winch  12 . 
     The self-tailing device need not be as shown in FIG. 5 but may be adapted from any standard self-tailing device normally applied to winches. 
     Although the winch drive shown in the drawings is battery driven, it could, for example, be driven by a wind-up clockwork motor directly, or by a clockwork motor via an electric generator.