Monitoring operation of a winch

A method of operating a winch having a winch drum mounted in a housing to reel in and pay out the cable over a plurality of repeated cycles of use during a period of use of the winch. A digital counter is mounted on the housing so as to be responsive to each rotation of the drum in both directions and arranged to generate a total count during the period of use which is indicative of the number cycles so that the winch can be taken out of operation for service when the number of rotations reaches a predetermined maximum. The digital counter includes a follower contacting a raised portion on an edge of the drum so as to be moved by the raised portion for actuating each count of the digital counter.

The invention relates a winch and to a method of monitoring operation of 
the winch to ensure safety of operation. 
BACKGROUND OF THE INVENTION 
In U.S. Pat. No. 5,344,121 of the present inventor there is disclosed a 
winch which is designed particularly for use in protecting a person 
entering an underground or unsafe area so that the person can be supported 
against falling and can be returned to a safe location in the event that 
the person becomes incapacitated. 
Winches of this type are now mandated when a person enters an underground 
location such as a tank or pipe line to ensure that the person is not 
injured by falling while entering the location and to ensure that the 
person can be retrieved to the surface in the event that the person 
becomes incapacitated due to injury or noxious gases. 
Winches of this type are carefully manufactured to particular tolerances 
and also are of the type which include a braking system so that the cable 
is held against further paying out once it is pulled. A manually operable 
handle cranks the winch drum in a direction to pay out the cable and in a 
direction to reel in the cable. In the paying out direction the handle is 
cranked to release the brake so as to allow the cable to be gradually paid 
out at a rate determined by the manual cranking of the drum rather than by 
the rate of pulling. The cable is therefore winched down into the 
underground location with the person generally as the person climbs down 
an entry ladder. In the event of falling, the brake holds the drum against 
further rotation in the paying out direction and allows the operator on 
the surface to crank the drum in the reeling in direction to pull the 
person back to the surface. 
It is of course important in winches of this type that they be maintained 
in proper operating condition so that there is no breakdown in an 
emergency situation. It is generally therefore not satisfactory that the 
winch is merely be repaired when broken but that there be a proper service 
procedure and time table by which it is maintained in proper operating 
condition. 
Up till now, such a servicing procedure has been based upon a time period 
so that it is proposed that the winch be returned for servicing after a 
predetermined period of time for example six months to ensure that 
servicing is of sufficient frequency to prevent breakdown. 
However this simple statement has generally been found to be insufficient 
to ensure that servicing occurs on the mandated time period. Generally the 
winch it self does not carry any indication of the date for servicing so 
that it is quite possible that the winch remains in operation for a period 
long past the due date. Generally nothing on the winch itself confirms to 
the operator that it is beyond its due date for service and therefore the 
winch is continued to be used. In practice this system does not lead to a 
proper servicing of the equipment. 
Secondly this system does not take into account different levels of usage. 
Some winches of this type are used heavily on a repeated basis and some 
are merely available for an emergency situation and therefore are used 
very infrequently. The specification of a predetermined time period for 
service does not take into account these different levels of usage. 
SUMMARY OF THE INVENTION 
It is an object of the present invention, therefore, to provide an improved 
winch and an improved method for servicing a winch which allows the winch 
to be maintained in a proper serviceable condition at all times. 
According to the invention, therefore, there is provided a winch 
comprising: 
a winch housing; 
a winch drum mounted in the housing for rotation about an axis of the drum 
for reeling in and paying out a cable; 
a drive member for driving rotation of the drum; 
the drum being arranged for rotation to reel in and pay out the cable over 
a plurality of repeated cycles of use during a period of use of the winch; 
and a digital counter mounted on the housing so as to be responsive to 
rotation of the drum, the digital counter being arranged to generate a 
total count during the period of use which is indicative of the number 
cycles. 
Preferably the digital counter is arranged so as to be responsive to each 
rotation of the drum. 
Preferably the digital counter is arranged so as to be responsive to each 
rotation of the drum during both movement in a direction for paying out 
the cable and in a direction for reeling the cable. 
Preferably the drum includes a raised portion thereof located so as to move 
past the digital counter and wherein the digital counter includes a 
follower contacting the drum so as to be moved by the raised portion for 
actuating each count of the digital counter. 
Preferably the follower comprises a roller. 
Preferably the raised portion is provided on a axially facing surface of 
the drum such that the raised portion moves the follower of the digital 
counter in an axial direction. 
Preferably the surface is provided on the peripheral edge of the drum. 
Preferably the digital counter includes a counter face exposed at an 
opening in the housing and wherein there is provided a cover attached to 
the housing and covering the digital counter. 
Preferably the counter face is located on a surface of the housing adjacent 
the drum and facing axially toward the drum, the opening being provided in 
a plate of the housing on one side of the drum and wherein the digital 
counter is mounted on a side of the plate opposite to the drum, the cover 
being mounted on the plate on the side thereof opposite the drum. 
Preferably the drum includes a shaft having a receptacle thereon for a 
manually operable handle, the shaft having a brake thereon arranged to 
halt rotation of the drum in a direction to pay out the cable in the event 
of the pulling of the cable.

DETAILED DESCRIPTION 
A winch 10 comprises a housing 11 formed by a back plate 12, a front plate 
13 and a base plate 14. The housing supports a drum 15 between the front 
plate and the back plate for rotation on a shaft 16 carried in bearings 17 
on the front plate and the back plate. The front and back plates have an 
arched upper edge 18 and a flat bottom edge 19 with the latter attached to 
the flat base plate 14. The back plate 12 as best shown in FIG. 3 is 
substantially simply a flat plate. The front plate 13 includes a flange 20 
which projects forwardly from a plate portion 21 so as to define a recess 
22 for receiving operating elements of the winch. The recess is covered by 
a cover plate 23 having a flat plate portion parallel the plate 21 and a 
flange 25 co-operating with the flange 20 at an overlapping lip 26. The 
cover plate 23 is bolted to the plate 13 so as to maintain the recess 22 
fully enclosed and the operating elements protected from tampering and 
damage. 
The drum 15 includes a cylindrical core portion 28 on which a cable 29 is 
wound. The cable passes through one of a pair of holes 30, 31 in the base 
plate 14 so that the cable can be reeled in by rotation of the shaft and 
the drum in one direction and can be paid out by rotation of the shaft and 
drum in the opposed direction. 
The drum includes a first side plate 32 adjacent to the back plate 12. The 
drum includes a second side plate 33 opposite to the side plate 32 and 
defining there between and annular receptacle for the cable 29 on the core 
portion 28. 
The side plate 33 includes a cylindrical flange portion 34 extending 
axially away from the core portion 28 and the cable and surrounding the 
shaft 16. The cylindrical sleeve portion 34 has an end surface 35 facing 
axially away from the end plate 32. The cylindrical sleeve portion 34 has 
a hollow interior 36 with a plurality of gear teeth 37 facing inwardly of 
the surface 36. A cylindrical flange 38 is formed on the rear surface of 
the front plate 13 and surrounding the outside surface of the cylindrical 
portion 34. 
A drive gear wheel 40 co-operates with the teeth 37 for driving the drum in 
rotation about the axis of the shaft 16. The gear wheel 40 is mounted on a 
shaft 41 carried in bearings on the plate 13. The shaft 41 carries a brake 
42 which co-operate with pivotal pawls 43 mounted on the plate 13. The 
brake co-operate with a sleeve 44 surrounding the shaft 41 and projecting 
outwardly through a hole 45 in the cover 23. On the end of the sleeve 44 
is provided a receptacle 46 for receiving manually operable handle shown 
schematically at 47. Rotation of the handle in one direction about the 
axis of the shaft 41 therefore drives the shaft 41 in the clockwise 
direction where the shaft is free to rotate and slip relative to the pawls 
43 thus driving the drum in a direction to reel in the cable. Rotation of 
the handle in the opposite direction drives the brake 42 against the pawls 
43 so that the drum is held against rotation in this direction unless the 
handle is driven in that direction sufficient to release the brake and 
thus allow the cable to be paid out. 
A more detailed description of the brake construction is shown and 
described in the above mentioned U.S. Pat. No. 5,344,121 of the present 
inventor 
A winch of this type has been manufactured and sold for a number of years. 
The winch as shown in the drawings has a drive system which applies drive 
only directly through the shaft 41 to the drum. As shown in the above 
patent, an alternative arrangement includes a second shaft with a chain 
communicating from a gear wheel on the second shaft to a gear wheel on the 
shaft 41 so as to allow a two speed drive system. The present invention 
may be applied to either of these types of winch. 
In accordance to the present invention, a winch as described above in 
modified by the addition of a digital counter 50. The digital counter 50 
includes a body 51 having a plurality of counter wheels 52 mounted within 
the counter body and exposed at a face 53 of the counter body. The counter 
is driven by a top shaft 54 so that reciprocation of the shaft 54 about a 
vertical axis through an angle of the order of 45.degree. causes 
incremental movement of the counter wheels to effect counting of a total 
of the number of reciprocations of the shaft 54. A reset screw 55 is 
provided on the bottom of the counter body and can be manually rotated to 
reset the counter wheels back to zero. The counter body includes a back 
plate 56 which covers a surface 57 of the body opposite to the face 
surface 53 with a back plate extending to each side of the body so that 
the body can be fastened to the plate portion 21 of the front plate 13 by 
four screws 58. 
The shaft 54 is operated in its reciprocating movement by a lever 60 
clamped onto the shaft 54 by a screw 61 so that the lever 60 projects 
outwardly to one side of the shaft. A spring 62 is attached to the 
clamping screw 61 and pulls the lever 60 in a counter clockwise to an 
initial position from which it is moved to effect counting of the strokes 
of reciprocation. 
The lever 60 is actuated by a cranking mechanism generally indicated at 70 
which co-operate with a raised portion 71 on the edge 35 of the 
cylindrical portion 34. The cranking mechanism includes a mounting block 
72 which is attached to the plate portion 21 of the front plate 13 at an 
opening 73 in the plate portion. The mounting block 72 carries a lever 74 
mounted on a shaft 75 for rotation about an axis which is parallel to the 
plate portion 21 and parallel to the bottom edge of that plate portion. 
The lever carries a roller 76 which rolls on the surface 35 and is pressed 
against that surface by the spring 62 communicating forces to the lever 60 
which pushes against the lever 74 and thus pivots the lever 74 toward the 
surface 35. The roller 76 is mounted a pin 77 carried on the lever 74. The 
pin 77 is below shaft 75 and above the lever 60. 
The raised portion 71 extends axially from the surface 35 by a height H 
which is sufficient to effect movement of the lever 74 to cause the 
reciprocation of the lever 60 to actuate a counting operation of the 
counter. 
Each rotation of the drum therefore whether occurs in the pay out direction 
or the reel in direction causes the raised portion 71 to pass the lever 74 
once for each rotation thus effecting an increment in the counter of one 
for each rotation. 
As shown in FIG. 1, the plate 13 includes a portion 13A thereof which 
extends outwardly from the flange 38 in the area adjacent the base plate 
11 so as to form a generally triangular area on the inwardly facing 
surface of the plate 13. The counter face 51 is provided at an opening 13B 
in the portion 13A of the plate 13. The counter wheels are therefore 
readily available in this area so as to provide a total count of the 
number of rotations of the drum. The lever mechanism operating the 
counter, the counter body and the manually operable screw of the counter 
body are all protected in the interior 22 of the front plate 13. 
In operation, the winch is repeatedly used during a period of operation for 
a plurality of cycles in which the cable is paid out and reeled in each 
times a person enters and area from which they are to be protected. Each 
pay out and reel in will cause a rotation of the drum through a number of 
turns of the drum depending upon the distance in which the person moves. 
The number of cycles and the number of turns of the drum in each cycle 
cause a predetermined amount of wear on the winch. The counting of the 
number of turns therefore provides an indication of this wear which is an 
indication of the number of cycles through which the winch has been used 
and the actual number of turns of the drum. When the counter reaches a 
predetermined maximum number, the winch clearly indicates this number on 
the visible counter. A label immediately adjacent the counter provides an 
indication of the maximum number of rotations which are acceptable before 
the winch needs to returned for service. The label is indicated at 100 and 
indicates the maximum number together with the requirement that the winch 
be returned for service. 
It is immediately apparent therefore to a user of the winch when the 
maximum number of operations has been exceeded so that the user is 
inhibited from using the device and it is clear to the user that a 
liability is incurred by using the device beyond its stated allowable 
number of operations. 
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 department 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.