Restraint mechanism for a control lever

In construction machines it quite common to utilize a plurality of control levers to manipulate a multitude of implements. It has often been a problem to quickly and accurately establish a connection between the control lever and the implement since the control lever is often quite some distance away from the mechanism that controls the implement. In many instances multiple personnel are required to properly assemble the various components. This leads to added expense and complexity of the assembly process. The present invention includes a restraint mechanism for a control lever that positively holds the control lever at a preselected location with respect to an established operational pattern. With the control lever locked in the preselected location, the connection of the control lever with the remaining components may be done in an extremely efficient and cost effective manner

TECHNICAL FIELD 
This relates generally to control levers and more particularly to a 
mechanism used to restrain the control lever from movement. 
BACKGROUND ART 
In construction machines it is very common to have multiple levers at an 
operators disposal to control the movement of the machine as well as the 
implements that are attached to the machine. These levers are commonly 
positioned within an operator station mounted on the machine and are 
connected by various linkage arrangements to control valves that in turn 
control the various implements and machine functions. It is very important 
that these levers are adjusted properly with respect to the connecting 
linkage to insure efficient operation of the machine. In many instances, 
the adjustment of these linkages occurs at a location that is remote from 
that of the control levers. It is important therefore to have a positive 
mechanism to hold the control lever in a preselected position, usually the 
neutral position, so that proper adjustment may be made to the connecting 
linkage. In many instances one individual is required to maintain the 
position of the control lever in the neutral position while a second 
adjusts the connecting linkage. Aside from being an inefficient use of 
personnel, it also lends itself to an inaccurate adjustment in the event 
two people are not available when it is necessary to make the proper 
adjustments. 
The present invention is directed to overcoming one or more of the problems 
as set forth above. 
DISCLOSURE OF THE INVENTION 
In one aspect of the invention a restraint mechanism for a control lever is 
disclosed. The restraint mechanism includes a base plate that defines a 
preselected path of movement for the control lever that includes a 
preselected location for a neutral position of the control lever. A bail 
member having a recess defined therein is mounted to the base plate for 
pivotal movement with respect thereto between a first position wherein the 
recess is in contact with the control lever to maintain the control lever 
in its neutral position and a second position wherein the recess is moved 
away from contact with the control lever to permit movement of the control 
lever. A means for locking the bail in one of its first or second 
positions is also included. 
With a control mechanism as set forth above, the control lever for an 
implement for a machine may be positively held in place in a preselected 
position, such as a neutral position, while the connecting links between 
the control lever and the implement are connected or adjusted. In doing 
so, the service and adjusting procedure is greatly simplified and the 
manpower required to perform the procedure is greatly reduced.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring now to the drawings, it can be seen that a control lever 10 is 
positioned to extend upwardly from a control module 12. The control module 
is positioned within a housing 14 in the cab of a construction machine or 
the like and controls the operation of an implement such as a winch, for 
example. The housing 14, which is only partially shown in the drawings, 
encases the control module and mounts a plate 16 on an upper portion 
thereof that defines an opening 17 that will be described in greater 
detail hereinafter. 
Referring to FIG. 2 it can be seen that the control lever 10 extends 
through the opening 17 in plate 16 to a location within the cab that is 
optimally within easy operating distance of an operator when he is in 
position to operate the machine. The opening 17 is defined by a series of 
connected channels or slots that are formed in the plate 16 to provide a 
preselected pattern of movement for the control lever. The slots are 
formed generally in an "M" configuration with respect to the operator and 
the control lever is of sufficient size to move freely along and between 
each of the slots. Movement in a first leg of the "M", or slot 18 as 
viewed in the drawings, corresponds to a specific implement function while 
movement in a second leg of the "M", or slot 20, will result in a 
different implement function. Movement in a third slot 22, positioned 
between the first and second slots, actuates a third implement function. A 
fourth slot 24, extends along an upper extremity of the slots and 
interconnects all of them. The fourth slot acts as a neutral slot when the 
control lever is moving from one slot to the next. One of the edges 26 of 
the fourth slot is angled and forms a slight recess 28 that is 
substantially centrally positioned along the edge 26 and is positioned for 
alignment with the third slot 22. 
A pair of bracket members 30 and 32 are secured to the housing 14 on 
opposing sides of the slots formed in the plate 16. Bracket 30 is mounted 
adjacent the first slot 18 and extends upwardly a distance sufficient to 
define a centrally disposed bore 34. The second bracket member 32 is 
positioned adjacent the second slot 20 and, like the first bracket, 
extends upwardly from housing 14 and defines a bore 36 (FIG. 1) that is 
substantially centrally disposed therethrough. 
A bail member 38 is positioned in overlying relationship to the slot 
pattern. The bail member is formed from a rod or similar cylindrical stock 
and defines a first leg portion 40 that has a diameter that may be 
received within the bore 34 of the first bracket member 30. Likewise, the 
bail member 38 defines a second leg portion 42 that is received in the 
bore 36 of the second bracket 32. A third portion 44 of the bail member 
extends between the first and second portions, connecting them together. 
The third portion 44 is angled to form a recess 46 that is substantially 
centrally positioned along the third portion. The angled portion 44 gives 
the bail member an overall configuration similar to that of an inverted 
"W" as positioned in relation to the operator. The location of the recess 
46 is such that it is in alignment in opposing fashion with the recess 28 
defined in the fourth slot 24. The opposing recesses 46 and 28 are spaced 
from one another a distance that is just large enough to receive the 
diameter of the control handle. In this position, the control lever is 
captured in a preselected neutral position, which in the illustrated 
implement, is a position that corresponds to a "brake on" condition for a 
winch. The bail member may be rotated to a second position away from 
contact with the control lever to allow the control lever freedom to move 
within and between any of the slots. 
A handle member 48 has a first end portion 50 that is secured to the first 
leg portion of the bail member 38. A second end portion 52 extends 
outwardly from the first portion 50 and defines a grasp for the handle 
member. The first portion 50 has a rounded surface 51 that terminates at a 
pair of detents 54 and 55 respectively that are positioned approximately 
180 degrees apart. The first detent 54 joins the rounded surface 51 at a 
juncture that forms a small cam lobe 56. In a similar fashion, a second 
cam lobe 58 is defined at the juncture between the second detent 55 and 
the rounded surface 51. 
A locking means, generally shown at 60, is shown as a spring member 61 of 
the type that is formed from sheet metal, spring steel or the like. The 
spring member includes a base member 62 that is adapted to be mounted to 
the housing 14 by a pair of bolts 64. A leg portion 66 is sprung from the 
base member 62 and extends upwardly from the base member. The base member 
is mounted adjacent the handle member 48 so that the leg portion 66 is 
biased against the first portion 50 of the handle 48. The leg portion 66 
defines a projection 68 that has a configuration that will allow it to 
nest within the detents 52 and 54. When engaged with either of the 
respective detents, the leg portion will maintain the handle member 50 in 
either of its first or second positions. 
Industrial Applicability 
In operation, the control lever 10 is shown to control multiple implement 
functions, through its movement within the preselected slot pattern, such 
as a winch assembly for example. In the disclosed embodiment, the control 
lever is operable in the first slot and second slots 18 and 20 to control 
the direction of rotation of the winch assembly. When operating in the 
third slot 22, the various brake functions for the winch assembly are 
controlled. When the control lever is operating in the fourth slot 24, the 
brake is maintained in the "on" position while the control lever is moved 
from one winch function to the other thus maintaining the winch in 
substantially a neutral condition. During this movement, the bail member 
38 is maintained in its second position as is shown in phantom lines in 
FIG. 2. In this position, the handle member 48, and thus the bail member 
38, is rotated to the right from the position shown in FIG. 3. In this 
position, the second detent 55 is engaged with the projection 68 defined 
on the leg portion 66 of the spring means 60, allowing the control lever 
to move unimpeded within the control pattern. 
When it is desirable to maintain the control lever 12 in a preselected 
neutral position, such as during assembly or after service, the handle 
member 48 may be rotated to the left as viewed in FIG. 3 to move the bail 
member 38 toward the control lever. When this motion is initiated, the cam 
lobe 58 will engage the leg portion 66 of the spring member and move the 
projection out of engagement with the detent 54 as rotation of the handle 
member occurs to permit movement of the bail member. The handle and bail 
members are permitted to rotate approximately 180 degrees until the first 
detent falls into engagement with the projection 68 of the leg portion 66. 
When in this position, the recess 46 of the bail member is aligned with 
the recess 28 defined by the fourth slot 24. The angled third portion 44 
of the bail member will move the control lever into a position between the 
aligned recesses 28 and 46 where it is captured and further movement 
within the control slots is prevented. 
It is to be understood that while this restraint mechanism is shown in 
conjunction with the operation of a winch assembly, it is well within the 
scope of the subject invention to be applicable to other implement 
controls as well. It is apparent that this restraint mechanism may be used 
to fix the position of a control lever in a preselected location. In doing 
so, the connections between the control module and the control lever may 
be established with the control lever in a known position. In doing so, 
the connections may be established by a single individual whether during 
initial installation or after the performance of some type of service 
procedure. This results in an extremely efficient and cost effective 
design. 
Other aspects, objects and advantages of this invention can be obtained 
from a study of the drawings, the disclosure and the appended claims.