Choker fair-lead assembly for tractors

A stationary upright frame is arranged to be mounted on the rear of a tractor and has a horizontal axis fair-lead drum over which choker cables from the drive drum of the tractor are reeved. The horizontal axis fair-lead drum is slidably supported in the upright frame for vertical adjustment by fluid operated cylinders whereby the drum can be moved from a low center of gravity position to an elevated position which holds the choker cables up off the ground.

BACKGROUND OF THE INVENTION 
This invention relates to a new and novel choker fair-lead assembly for 
tractors. 
Heavy duty tractors are commonly used for skidding logs between various 
points. In such operation, choker cables are used having means at the end 
thereof for attachment to a log and having their other ends attached to 
the powered winch drum of the tractor. The winch drum is at a relatively 
low point on the tractor so as to maintain the center of gravity of such 
tractor at a low point. When the tractor is returning for another load, 
the choker cables drag along behind, and frequently when the tractor is 
maneuvered along its various returning paths and for connection to another 
load, it runs over the dragging choker cables and tears them off. Such of 
course requires the costly replacement of the choker cables and 
furthermore may damage portions of the tractor. 
SUMMARY OF THE INVENTION 
According to the present invention and forming a primary objective thereof, 
a choker fair-lead assembly is provided which is adapted for use with 
tractors in an arrangement such that choker cables attached to the powered 
winch drum can be elevated and thus raised off the ground and out of the 
way of the tractor when the latter is running empty, the structure also 
including the objective of allowing the fair-lead assembly to operate in a 
lowered adjusted position if desired to provide a center of gravity of 
pull for the tractor at a low point. Since the winch drum can be raised, a 
log being dragged can be lifted at its forward end to clear obstructions 
such as stumps. 
Another object is to provide a choker fair-lead assembly of the type 
described that is simple in construction and operation and readily 
adaptable to existing tractors. 
In carrying out the objectives of the invention, the assembly includes a 
mounting base plate arranged to be secured to a tractor just above the 
winch drum. This base plate supports an upright frame providing slidable 
movement for a horizontal axis fair-lead drum over which choker cables 
from the winch drum extend. The drum is associated with vertically 
extensible drive means arranged to move and hold the drum at selected 
vertical positions on the frame. The drive means preferably comprise 
multiple stage fluid operated cylinders one on each side of the frame for 
end support of the drum. The structure of the present assembly facilitates 
ready attachment to present day tractor structures, including existing 
tractors. 
The invention will be better understood and additional objects and 
advantages will become apparent from the following description taken in 
connection with the accompanying drawings.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
With particular reference to the drawings, the numeral 10 designates a 
conventional tractor of a suitable type that is capable of use in the 
woods for skidding logs. Such tractor has a powered winch drum 12 mounted 
on one end thereof, usually the rear end, by side frames 14 integral with 
the tractor. Tractors 10 of this type usually are provided with a canopy 
frame 16. 
According to the present invention, a base plate 18 is supported on the 
winch drum housing and has vertical side plates 20 extending down the 
sides of the winch drum housing. These sides plates have a bottom segment 
20a and such segment and its plate are clamped around a projecting shaft 
portion 17 of the winch drum. Base plate 18 is of the shape shown in FIG. 
4 and has a rear recess 22 accommodating the chokers C in the operation of 
the fair-lead, as will be more apparent hereinafter. A front recess 24 in 
the base plate 18 may also be provided to make clearance for the chokers 
in certain positions of the latter. 
A pair of side frames 30 are secured, as by welding, to the base plate 18 
and are secured together at the top by a frame member 32. The side frames 
have reinforced connection to the tractor by gusset plates 34 adjacent the 
bottom welded between the tractor and such side frames. Top stabilizing 
arms 36 are secured, as by welding, between the upper portion of the side 
frames 30 and the tractor canopy frame 16. Arms 36 preferably include 
rubber grommet connections 38 with the tractor to provide a 
shockproof-type connection between the upright frame 30 and the canopy 
frame 16. In a preferred arrangement, the upright frame 30 is tilted 
rearwardly a slight amount as best seen in FIG. 3. 
Each of the side frames 30 has a vertical guide slot 40 slidably receiving 
slide blocks 42 having apertures 44 providing bearing support for end stub 
shafts 46 of a horizontal fair-lead drum 48 over which the chokers from 
the winch drum 12 operate. Slide blocks 42 are movable in slots 40 to 
provide guided movement of the drum 48 vertically in the side frames 30 
and have end plates 50 overlapping inner and outer surfaces of the side 
frames to provide a positive guided movement. Bearing liners 52 are 
provided in all sliding surfaces between the members 30 and 42, 50. 
Outer guide plates 50 are integral with inverted U-shaped brackets 54 
secured to the piston rod of fluid operated cylinders 56 secured at the 
bottom to side plates 20 and at the top to the top wall of the U-shaped 
brackets 54. The bottom and top connections for the fluid operated 
cylinders comprise pivotal connections 58 which allow for slight frame 
movement if such should occur under a heavy load on the frame. Cylinders 
56 preferably comprise multiple stage cylinders to facilitate a relatively 
long driving stroke but a short retracted length of the assembly. 
Side boxes 53, broken away in FIGS. 1, 2 and 3 and shown in full lines in 
FIG. 4, are secured as by welding, to the outer sides of the frame 30 and 
enclose the cylinders 56 and the brackets 54 for protection. Suitable 
access plates, not shown, are removably mounted on the lower end of each 
side box to provide access to the cylinders. Top frame member 32 of the 
side frames is extended rearwardly a short distance and vertical fair-lead 
guide bars 60 are supported between such top plate extension and the base 
plate 18. These vertical guide bars are disposed on opposite sides of the 
frame and serve to guide the chokers laterally as they operate over the 
drum 48. Guide bars 60 preferably have a rotatable mount. 
In the operation of the present choker fair-lead assembly, the one or more 
chokers C pass from the winch drum 12 over the top of the horizontal 
fair-lead drum 48, a clearance for the chokers past the base plate 18 
being through the recess 22. When the operator is returning to connect to 
another load, the chokers can be wound inwardly on the drum 48 and the 
latter elevated a selected amount whereby the chokers hang free of the 
ground. When the tractor is pulling a load, the operator can decide the 
vertical position at which the drum 48 is to be located. Preferably, the 
drum 48 at this time is lowered so that the center of gravity of pull is 
at a lowered point, whereby the tractor can pull a load almost as heavy as 
if the choker cables came directly off the drum 12 to the load. The drum 
can be raised a little, however, if it is desired to lift the forward end 
of the log over an obstruction such as a stump. 
According to the present invention, the choker fair-lead assembly is 
provided that can raise the choker cables to an elevated position so that 
the tractor can maneuver while unloaded without running over the choker 
cables, and furthermore a low center of gravity can be provided by 
lowering the drum when pulling heavy loads. If desired, however, the drum 
48 can be maintained in an elevated position when the tractor is operating 
with light loads. Suitable controls can be provided for operation of the 
cylinders 56 either in the cab or at the winch, or both. 
It is to be understood that the foam of my invention herein shown and 
described is to be taken as a preferred example of the same and that 
various changes in the shape, size and arrangement of parts may be 
resorted to without departing from the spirit of my invention, or the 
scope of the subjoined claims.