The invention relates to the positioning and operation of controller towers for backhoes. More specifically, it relates to a method, system and apparatus for safely and securely positioning controller towers to allow the operator to easily and conveniently move the traditional swivel seat often associated with backhoe cabs into and out of the backhoe operating position.
Backhoes are often equipped with an operator station having a dual position swivel seat which allows the operator to remain seated as he/she pivots between loader and backhoe operations. Such a provision normally requires movable controller towers as controller towers that are properly located for optimum operator convenience and comfort in backhoe operation usually interfere with the operator's legs and/or with the seat as the operator pivots between backhoe and loader functions. The movable controller towers usually have two basic positions: (1) the stow position which allows the operator to move the swivel seat into and out of the backhoe operating position; and (2) the backhoe operating position which allows the operator to comfortably operate the backhoe when the swivel seat is in the backhoe operating position.
Conventional movable controller towers are mounted such that one controller tower is located on each side of the seat, each controller tower being secured in either of the two basic positions via releasable cable and latch mechanisms.
The inventors recognize that conventional movable controller towers require a significant amount of extra hardware for cable and latch mechanisms as well as extra labor to produce and assemble the hardware. Further, the additional hardware occupies precious portions of limited available space that could be used for other valuable purposes. Finally, the transverse shaft, commonly shared by both controller towers in some conventional systems, is exposed to the detriments of the environment as it is located under the cab floor; it also reduces functionality in the system by requiring simultaneous movement of the towers.
The invention overcomes each of the above mentioned limitations of conventional controller towers via an elegantly simple mechanism. Simple mounting brackets are fixedly attached to portions of the frame or floor on either side of the seat. A shaft, some ball bearings and a snap ring secure each tower to the mounting brackets via a hole in the brackets and serve as a pivot for the independent movement of each tower to each of its positions. A gas filled strut, operatively attached to each tower and corresponding mounting bracket, provides a toggle or over-center effect as each tower is moved from one of its two positions to the other. Thus, an operator may change the position of a tower by pushing or pulling a portion of the tower structure. Adequate extending forces of each strut keeps each of the towers in either of their dual positions, thus eliminating the need for cables and latches to lock the towers. The common rotational shaft, present in some conventional systems, is also eliminated, increasing available space on the underside of the floor for greater access to other components. Finally, the time and cost for parts and labor for each controller tower are reduced.
Embodiments of the invention will be described in detail, with references to the following figures, wherein:
The mounting bracket 110 includes a first mounting side 110a containing mounting holes 110d and 110e; a second mounting side 110b containing mounting holes 110f and 110g; and center portion 110h, including two controller tower stop assemblies 114 and 115, a hole 112 for attaching the strut assembly 120 to the mounting bracket 110, and a race 110c for pivotally attaching the controller tower 130 to the mounting bracket 110. The mounting bracket 110 is securely attached to left frame members 170 and 171 as well as the cab floor 180 via mounting holes 110d, 110e, 110f and 110g by means well known in the art. See
The strut assembly 120 includes a conventional gas filled strut 121 having a first end 121a and a second end 121b. The first and second ends 121a, 121b are constructed for attachment to working structures in manners well known in the art via eyelets 122, each eyelet having three dimensional rotation characteristics.
The movable controller tower 130 includes a mounting plate 131 having two square positioning holes 133 for positioning a first stiffening rib 137a and a square hole 136 for positioning rotationally fixed screw 126. Attached to the mounting plate, via welding are a hose harness 137a, a second stiffening rib 137b, a third stiffening rib 137c, a pivot shaft 134 and a controller cage 150. The stiffening ribs 137a, 137b and 137c are positioned as shown in
The armrest assembly 140 includes a strong and rigid support arm 142 having a pivot hole 144 and an adjustment hole 143. The support arm 142 may be constructed of a metal such as steel. The armrest assembly 140 also includes a soft surface mounted to the support arm 142. The soft surface may be provided by a padded roller 141 rotationally mounted to the support arm 142 as in the embodiment described and illustrated herein (see
The mounting plate 131 is operatively attached to the first end 121a of the gas filled strut 121 via the square hole 136, the screw 126, the spacer 129, the eyelet 122a, a spacer 123 and the nut 124. The second end 121b of the gas filled strut 121 is attached to the mounting bracket 110 via nut 124, bolt 125, hole 112, eyelet 122b and three spacers 123, 123, 123 as shown in
The mounting plate is rotationally attached to the mounting bracket 110 via the pivot shaft 134, ball bearings 191, 192, a spacer 193, a snap ring 194 and the race 110c. During assembly of the mounting plate 131 to the mounting bracket 110, ball bearings 191 and 192 press fit into the hole provided by the race 110c. The pivot shaft 134 is then slip fitted into the ball bearings 191 and 192, the spacer 193 is fitted over the pivot shaft 134 and, finally, the snap ring 194 is assembled to the pivot shaft 134 via shaft groove 135. Thus, movement of the mounting plate 131 at the pivot shaft 134 is constrained by the mounting bracket 110 in all directions excepting a rotational motion about an axis of the pivot shaft 134.
The gas filled strut 120 is compressive and is assembled to the controller tower 130 and the mounting bracket 110 such that it is shortest at an intermediate position between the stow and backhoe operating positions of the controller tower 130 (see
Resistance to movement from the stow position or the backhoe operating position is sufficient to keep the controller tower 130 in that position. The application force required to overcome the resistance may be preset at a minimum of, for example, 20 pounds.
The stops 114 and 115 define each of the rotational limits for movement, i.e., the stow position and the operating position, respectively, for the controller tower 130. In the stow position, surface 131a contacts the stop 114 and prevents further movement of the controller tower 130 away from the intermediate position. In the operating position, the surface 131b contacts the stop 115 preventing further movement of the controller tower 130 away from the intermediate position.
Having described the illustrated embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
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Number | Date | Country | |
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20050055852 A1 | Mar 2005 | US |