Motion controller handrest with lever lock

A dragline comprises a main chassis, a mechanism for moving the main chassis over the ground, a boom mounted on the main chassis, a sheave rotatably mounted on the boom, a dragline bucket, a hoist rope reeved over the sheave and having an end connected to the bucket to raise and lower the bucket, a drag rope connected to the bucket to pull the bucket toward the main chassis and to allow the bucket to move away from the main chassis, and an operator station on the main chassis, the operator station including a control lever apparatus for permitting an operator to control one of the mechanism, the hoist rope and the drag rope. The control lever apparatus includes a housing having therein a control mechanism for operating one of the mechanism, the hoist rope and the drag rope, a control lever mounted on the housing and operably connected to the control mechanism, the control lever being movable in a single plane relative to the housing, a shroud generally exterior of the housing, the shroud providing a rest for supporting an operator's hand gripping the control lever, and a locking mechanism mounted on the shroud and including a locking member which is movable relative to the housing for selectively capturing the control lever and thereby preventing movement of the control lever relative to the housing.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to operator controls for apparatus such as 
earth moving equipment or construction and mining equipment. 
2. Description of Related Art 
Conventional mining equipment includes an operator control station having 
one or more control levers for controlling various components of the 
equipment. A control lever is typically pivotally mounted on a housing 
which contains a control mechanism operated by the lever. The control 
mechanism is operably connected to the component being controlled. 
SUMMARY OF THE INVENTION 
The invention provides an improved control lever apparatus of the type 
described above. The control lever apparatus includes a locking mechanism 
exterior of the housing for capturing the control lever and thereby 
preventing movement of the control lever relative to the housing. The 
locking mechanism preferably includes a locking member which is movable 
relative to the control lever for capturing the control lever. 
The invention also provides a control lever apparatus including a shroud 
exterior of the housing. The shroud has an upper surface which provides a 
rest for an operator's hand gripping the control lever. Preferably, the 
shroud supports the above-mentioned locking member. 
More particularly, the invention provides a control lever apparatus for 
operating a dragline or similar equipment. The control lever apparatus 
includes a housing which is mounted to a surface by fasteners. The housing 
has therein a control mechanism for operating the walking mechanism, hoist 
rope or drag rope of the dragline. A control lever is movably mounted on 
the housing and operably connected to the control mechanism. The control 
lever is movable in a single plane relative to a vertical position. A 
generally U-shaped, plate-like shroud is mounted exterior of the housing 
by the same fasteners mounting the housing to the surface. The upper 
surface of the shroud provides a handrest for the operator. A locking 
member or plate is supported underneath the upper portion of the shroud 
for sliding movement relative thereto between an extended position and a 
retracted position. The plate has therein a notch. When the plate is 
extended, the notch captures the control lever in the vertical position 
and thereby prevents movement of the control lever relative to the 
housing. 
In conventional draglines, the brakes for the walking mechanism, hoist 
rope, and drag rope are automatically released or disengaged when the 
control lever is moved from the vertical position. The locking mechanism 
prevents accidental movement of the control lever from the vertical 
position, such as when the control lever is accidentally bumped by the 
operator leaving his seat to take a break, and thereby prevents release of 
the brakes and unexpected movement of the component controlled by the 
control lever apparatus. By supporting an operator's hand gripping the 
control lever, the shroud reduces operator fatigue. The shroud and locking 
mechanism can be mounted exterior of the control lever housing on new or 
existing equipment with minimal expense and complexity. 
Other features and advantages of the invention will become apparent to 
those skilled in the art upon review of the following detailed 
description, claims and drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Illustrated in the drawings is a dragline 1 embodying the invention. The 
dragline 1 includes a main chassis 2 which has a walking mechanism 3 
operable in known manner to move the dragline 1. A boom 4 is mounted at 
its lower end or foot 5 on the main chassis 2. A mast assembly 6 is 
provided to support the upper end 7 of the boom 4. A sheave 8 is rotatably 
mounted on the upper end 7 of the boom 4, and an elongated lifting element 
or hoist rope 9 is reeved over the sheave 8. A dragline bucket 10 is 
suspended from one end 11 of the hoist rope 9. The other end 14 of the 
hoist rope 9 is connected to a conventional hoist drum (not shown) on the 
chassis 2. The hoist drum is operated in known manner to raise and lower 
the hoist rope 9 and bucket 10. The dragline also has a conventional 
service platform 18 located at the upper end 7 of the boom 4. 
One or more drag ropes 15 are connected to the bucket 10. In order to 
simplify the drawing, FIG. 1 shows a single drag rope 15 connected to the 
bucket 10, but in actual practice more than one drag rope 15 is frequently 
required. The drag rope 15 is controlled by an operator to pull the bucket 
10 toward the main chassis 2 and to release the drag rope 15 to allow the 
bucket 10 to move away from the main chassis 2. The dragline 1 also 
includes an operator station 16, described in further detail below, from 
which the operator controls the dragline 1. The dragline 1 as thus far 
described is conventional and will not be described in greater detail. 
The operator station 16 includes (see FIG. 2) a seat 20 for the operator, 
and right and left control lever apparatus 21 and 22 for controlling the 
walking mechanism 3, hoist rope 9 and drag rope 15. The right control 
lever apparatus 21 controls the hoist rope 9. Depending upon the position 
of a mode selection switch (not shown), the left control lever apparatus 
22 controls the drag rope 15 and walking mechanism 3. However, the 
controls as stated can be just the opposite. The control lever apparatus 
21 and 22 are mirror images of each other, and only the control lever 
apparatus 21 will be described in detail. 
The control lever apparatus 21 includes (see FIGS. 2-6) a housing 23 fixed 
on a generally horizontal surface 24 by fasteners 25. The housing 23 has 
therein (see FIG. 5) a control mechanism 26 (shown schematically) for 
operating the drag rope 15. An elongated control lever 27 (FIGS. 3-5) is 
operably connected to the control mechanism 26. The control lever 27 is 
pivotally movable about a horizontal axis 28 (FIGS. 4 and 5) relative to 
the housing 23 and is movable relative to a vertical position illustrated 
in FIGS. 3-5. In the illustrated arrangement, the control lever 27 is 
movable only in a single vertically extending plane 29 (FIGS. 4 and 5). 
Movement of the lever 27 is indicated by broken arrows in FIG. 3. In other 
arrangements (not shown), movement of the control lever 27 is not 
restricted to a single plane. 
A shroud 30 is mounted exterior of the housing 23. The shroud 30 is a 
plate-like member bent into an inverted U-shape. The shroud 30 includes an 
upper portion 31 having opposed upper and lower surfaces 32 and 33. The 
upper surface 32 provides a rest for supporting (see FIGS. 3 and 4) an 
operator's hand gripping the control lever 27. In an alternative 
arrangement (not shown), the upper surface 32 is padded with a material 
such as foam or fabric to ensure comfort of the operator's hand. The 
shroud 30 also includes (see FIGS. 3 and 6) opposite side portions 34 and 
35 depending from the upper portion 31. The lower end of each side portion 
34 and 35 has thereon two inwardly extending ears 36. The fasteners 25 
extend through apertures 37 (FIG. 6) in the ears 36, through apertures 
(not shown) in the housing 23, and into apertures (not shown) in the 
surface 24 to secure the shroud 30 and the housing 23 to the surface 24. 
A locking mechanism 38 (FIG. 3) is mounted on the shroud lower surface 33. 
The locking mechanism 38 includes (see FIG. 6) a locking member or plate 
39 having an upper surface 40, opposed front and rear edges 41 and 42, 
opposed right and left edges 43 and 44 and a flange 45 depending from the 
front edge 41. The plate 39 is slidably supported by brackets 46 and 47 
which are mounted on the lower surface 33 of the shroud upper portion 31 
and which respectively engage the right and left edges 43 and 44 of the 
plate 39. The plate 39 is slidable relative to the shroud 30 between an 
extended position shown in FIGS. 3, 4 and 5 and a retracted position shown 
in FIG. 2 and shown in phantom in FIG. 4. When the plate 39 is in the 
retracted position, the front edge 41 and a substantial portion of the 
plate 39 are beneath the shroud upper portion 31. The remainder of the 
plate 39 extends to the right of the shroud 30 as shown in FIG. 2. The 
front edge 41 is proximate the control lever 27 and has therein (see FIGS. 
3, 4 and 6) a notch 48 for capturing the control lever 27 and thereby 
preventing movement of the control lever 27 relative to the housing 23. 
The notch 48 has (see FIG. 6) an open end 49 and an inner portion 50. The 
notch 48 is flared at the open end 49, and the width of the notch 48 at 
the open end 49 is sufficiently greater than the outside diameter of the 
control lever 27 that the control lever 27 is easily guided into the notch 
48. The inner portion 50 of the notch 48 has a width approximately equal 
to, but slightly greater than, the outside diameter or width of the 
control lever 27, to substantially prevent any movement of the control 
lever 27 when the control lever 27 is captured in the inner portion 50 of 
the notch 48. Movement of the control lever 27 is prevented to the extent 
necessary to prevent the brake on the hoist rope 9 from being released as 
long as the control lever 27 is housed in the inner portion 50 of the 
notch 48. The front edge 41 of the plate 39 engages the control lever 27 
to prevent capture of the control lever 27 when the control lever 27 is 
not in the vertical position shown in FIG. 1. The flange 45 extends 
downwardly from the front edge 41 to prevent the plate 39 from sliding too 
far into the brackets 46 and 47 in the retracted position, and to provide 
a grip for the operator to slide the plate 39 between the retracted and 
extended positions. 
In other embodiments of the invention (not shown), the locking mechanism 38 
can be configured differently. For example, the locking member 39 may 
rotate or move in a manner other than sliding relative to the shroud 30. 
Also, in some embodiments, the locking member 39 may be fixed such that 
the control lever 27 is moved into the notch 48. Further, in some 
embodiments, the locking mechanism 38 may be mounted on the control lever 
27 or housing 23 instead of on the shroud 30.