Winch with reverse rotation protection

A winch drum having a cable wrapped around a cylindrical surface of the drum and clamped to one end plate of the drum is modified by the addition of a member which inhibits reverse winding of the cable onto the drum. The member is attached to the clamped end of the cable and includes a tubular portion which is arcuate so as to follow the curvature of the cylindrical surface of the drum with a part cylindrical plate portion which projects outwardly to one side of the cable so as to lie flat against the cylindrical surface of the drum. When the cable is paid out to the maximum position, the member leaves the drum and impacts the frame of the winch to prevent or inhibit continued rotation of the drum in the payout direction which would otherwise cause winding of the cable in the reverse direction. The device for preventing reverse winding is particularly useful in winches which include a safety brake to restrict and control payout of the cable.

BACKGROUND OF THE INVENTION 
This invention relates to a winch which includes a member attached to the 
cable adjacent its fixed end to the winch drum to prevent or inhibit 
continued rotation of the drum in a direction to pay out the cable which 
would otherwise cause reverse winding of the cable onto the drum. 
Winches of course generally include a drum mounted in a frame and rotatable 
relative to the frame. The drum includes a cylindrical surface around 
which a cable is wound. With the cable wound in a first direction from a 
first fixed end of the cable, rotation of the drum in the same first 
direction acts to pay out the cable and rotation of the drum in the second 
opposed direction acts to wind in the cable. 
If the winch drum is rotated in the first direction paying out the cable to 
a position angularly beyond the position in which all of the cable is paid 
out, the cable is kinked back on itself and then is wound in the second 
direction around the drum. 
In many winches the direction of winding of the cable onto the drum is of 
little importance except that of course it reverses the direction of 
rotation necessary to wind in and payout the cable. 
However some winches, particularly those used for safety situations include 
a brake which will prevent the winch drum from rotating in the payout 
direction in the event that there is a significant pulling force on the 
cable due to for example the falling of a person being winched or pulled 
in. 
One example of a winch of this type is shown in U.S. Pat. No. 5,344,121 of 
the present inventor. 
In the event that a winch of this type is taken beyond the maximum payout 
position of the cable and the cable rewound in the opposed direction, the 
brake becomes inoperative and the safety provided by the winch is 
compromised. 
Up till now this problem has been inhibited simply by providing markings on 
the cable to warn the user that the end position is approaching. However 
situations have been encountered where the warning markings have been 
ignored and the winch drum rotated beyond the maximum payout position so 
that the cable is wound in the opposed or wrong direction. 
SUMMARY OF THE INVENTION 
It is one object of the present invention, therefore, to provide an 
improved winch which has enhanced safety features. 
According to one aspect of the invention there is provided a winch 
comprising: a winch cable; a winch drum having a cylindrical surface for 
receiving turns of the winch cable wrapped therearound; means mounting the 
winch drum for rotation about an axis longitudinal of the cylindrical 
surface; the winch cable having a first end attached to the drum for 
rotation therewith and a second free end for attachment to an object to be 
wound in and being wrapped around the drum in a first direction such that 
rotation of the drum in the first direction pays out the winch cable and 
such that rotation of the drum in the second opposed direction winds in 
the cable; and a member attached to the cable adjacent the first attached 
end for inhibiting winding of the cable onto the drum in the second 
direction in the event that the drum is rotated in the first direction 
angularly beyond a position in which all of the cable is paid out.

DETAILED DESCRIPTION 
The winch shown in FIGS. 1, 2 and 3 comprises a winch drum 10 including a 
cylindrical drum portion 11 having a cylindrical outer surface 12 for 
receiving a winch cable 13 wrapped therearound in parallel side by side 
turns and in rows of those turns. The drum further includes circular end 
plates 14 and 15 which are attached to ends of the cylindrical drum 
portion 11 to define a receptacle for the wrapped turns of cable. The drum 
is mounted on a shaft 16 carried in bearings of a frame generally 
indicated at 18. The frame includes two side plates 19 and 20 together 
with end plates 21 and 22 interconnecting the side plates 19 and 20. Thus 
the frame forms a rectangular structure usually having an open top and an 
open bottom at which the drum 10 is exposed. The shaft 16 is attached to a 
handle 23 which can be manually actuated by hand grasp portion 24 for 
rotating the shaft 16 and therefore the drum in either direction for 
paying out and winding in the cable 13. A brake 25 is provided between the 
shaft and the frame so as to restrict rotation of the drum in the payout 
direction except when the handle is rotated to payout the cable in a 
controlled manner. Thus the brake will prevent uncontrolled pulling of the 
cable in the event that a significant force is applied to the cable. 
The cable includes an attached first end 26 which is connected to the drum 
10 by a suitable clamp. In the example shown the clamp comprises a screw 
fastened collar 27 which engages the end 26 and clamps it to the end plate 
14. The cable further includes a free end 28 for attachment to an object 
to be moved by the winch. In the figures, the cable is shown in a 
condition in which the majority of the cable is paid out so that only a 
few turns of the cable remain on the drum including an end turn 29 of the 
cable at the end plate 14 and two adjacent turns 30, 31 laid down in 
helical manner adjacent the end turn 29. 
The above described structure of winch is entirely conventional and it will 
be appreciated that the illustration is relatively schematic showing only 
one simple example of a winch driven by a simple handle. It will of course 
be appreciated that the structure of the winch can be modified in many 
different ways or within the knowledge of one skilled in the art. 
In the present invention the conventional winch is modified by the addition 
of a member 40 which is attached to the cable adjacent the attached end 26 
to prevent or inhibit reverse winding of the cable onto the drum. 
Thus it will be appreciated that, as best shown in FIG. 2, from the 
attached end 26 the cable is wrapped around the drum in a first direction 
41 so that the cable is wrapped in a clockwise direction toward the free 
end 28. It will be further appreciated that rotation of the drum by the 
handle 23 in the first direction 41 will cause payout of the cable from 
the drum. Also it will be appreciated that rotation of the drum in a 
second opposed direction 42 will cause wind up of the cable onto the drum. 
In the event that the drum is rotated in the direction 41 to effect payout 
of the cable to a position in which the attached end 26 passes the 
position that the cable leaves the drum, the cable will commence rotation 
in the opposite direction, in the absence of the additional member 40 
which prevents or inhibits such rotation. 
The member 40 comprises a first portion 43 in the form of a rigid arcuate 
portion having a length of arc less than 180.degree.. In particular the 
portion 43 comprises a tube through which the cable passes with that tube 
to form an arc and with that tube having an inside surface following the 
curvature of the surface 12. The tube has a first end 44 closely adjacent 
or at the attachment end 26 of the cable and a second end 45 spaced 
angularly around the drum surface 12. The cable is clamped inside the tube 
or spot welded to the tube to prevent the tube from sliding off the cable 
or moving along the cable. As the portion 43 comprises a tube, the ends of 
the cable are fixed relative to the portion 43. 
The member 40 further includes a plate portion 46 which is attached to the 
first portion 43 and extends outwardly therefrom to one side thereof. The 
plate portion 46 is part cylindrical in shape so that it is arcuate in 
transverse cross section as best shown in FIG. 2. The curvature of the 
plate follows the curvature of the surface 12 so that it lies flat against 
the surface 12. The length of the plate so that is arranged so that it 
extends from a first end 47 attached to the tube portion 43 to a second 
end 48 closely adjacent the end plate 15 of the drum. The plate portion 
also has side edges 49 and 50 angularly spaced around the drum. The width 
of the plate between the side edges 49 and 50 is slightly less than the 
length of the tube 43 between the ends 44 and 45. 
In normal operation, when the cable is initially wound around the drum, the 
member 40 lies down onto the surface 12 with the tube portion 43 lying 
adjacent or butting the end plate 14 in view of the fact that it is 
adjacent the clamped end 26 of the cable which is attached to the end 
plate 14. 
Further rotation of the drum in the direction 42 to wind in the cable 
causes the cable to wind in turns wrapped around the drum and thus 
overlying the outer surface of the plate portion 46. If properly guided 
the cable lies in turns which are side by side as shown but of course this 
is not necessary for proper winding of the cable and the cable may wrap 
freely around the drum at various axial positions along the length of the 
drum to build up wraps of turns around the drum. In any event all of the 
turns lie on top of the outer surface of the plate portion 46. 
When the drum is turned in the direction 41 to payout the cable, the cable 
is freely paid out to a position approaching the clamped end 26 at which 
is provided a marker 60 on the cable for indicating to the operator that 
the cable is approaching the end and should not be further paid out. 
In the event that the marker 60 is ignored and continued rotation of the 
drum in the direction 41 occurs, the cable continues to be paid out until 
the end 45 of the tube 43 reaches a position adjacent the bottom of the 
drum, at which time it is pulled away from the drum so that the portion 43 
carrying the plate 46 is pulled away from the drum and carried on that 
portion of the cable which depends from the bottom of the drum below the 
clamp 27. This action tends to twist the cable so that the plate portion 
projects outwardly away from the cable in the form of a flap. In the event 
that the drum is yet further rotated in the direction 41, the clamp 27 
commences rotation around with the drum from a position adjacent the 
bottom of the drum upwardly toward the left in the view of FIG. 2 and the 
flap provided by the plate portion 46 impacts a bottom edge 21A of the end 
plate 21 and thus inhibits or prevents further rotation of the drum in 
that direction. At this position it is entirely clear to the operator that 
there is an inhibition of the movement and the operator cannot continue to 
rotate the drum in that direction without causing damage to the structure. 
Thus when the operator has realized that the rotation in the direction 41 
is inhibited, the operator will reverse the direction to rewind the cable 
onto the drum. This movement in the direction 42 causes the tube portion 
43 to be laid back down in its initial position adjacent the end plate 14. 
Similarly the plate portion 43 is laid back down onto the surface 12 
allowing further turns of cable to be wrapped. 
While the member as described and shown in the embodiment includes the 
tubular portion 43 and the plate portion 46, both of which are arcuate, it 
will be appreciated that alternative shapes can be used which act to 
inhibit the movement of the cable in the reverse direction. 
Since various modifications can be made in my invention as herein above 
described, and many apparently widely different embodiments of same made 
within the spirit and scope of the claims without departing from such 
spirit and scope, it is intended that all matter contained in the 
accompanying specification shall be interpreted as illustrative only and 
not in a limiting sense.