Abstract:
The backhoe loader of the present invention allows an operator to move the backhoe loader without having to take the time to turn the seat around or use the backhoe to push the backhoe loader to the desired location. In addition to the standard front controls that are found on every backhoe loader, rear controls similar to the front controls are added. The front and rear controls are connected to a master switch which determines whether the front or rear controls are used to operate the backhoe loader&#39;s drivetrain and brake systems.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Technical Field  
         [0002]     The present invention relates to the field of drivetrains for heavy machinery, and more particularly to the area of a drivetrain for a backhoe loader.  
         [0003]     2. Description of Related Art  
         [0004]     Backhoe loaders, commonly called backhoes, have been in existence since at least the 1960&#39;s. They are used to dig ditches to lay pipes and underground cable, set up foundations for buildings, create drainage systems, and the like. One of the most common applications for a backhoe loader is the basic job of digging a trench with the backhoe and then back-filling it with the loader.  
         [0005]     A backhoe loader is an interesting machine because it is actually three pieces of construction equipment combined into a single unit: a backhoe, a loader and a tractor. Each piece of equipment is suited to a particular sort of work.  
         [0006]     The core structure of a backhoe loader is the tractor. Similar to tractors used in farming, the backhoe tractor is designed to move easily over numerous types of terrain from rough to smooth and/or muddy to dry. Employed are a powerful diesel engine, large rugged tires, and a cab with basic steering controls (a steering wheel, brakes, etc.) located in the front cab of the backhoe loader. The tractor component is used for moving the other two components from place to place. The operator also maneuvers it when using the loader.  
         [0007]     The loader component is attached at the front end of the backhoe loader. The loader can do several different things. In many applications, it is used like a big, powerful dustpan or coffee scoop. The loader is mostly used to pick up and carry large amounts of loose material. It is also used to smooth things over like a butter knife or to push dirt like a plow. The operator controls the loader while driving the tractor with controls located in the front end of the backhoe loader.  
         [0008]     The backhoe is the main tool of the backhoe loader and is attached to the back end of the machine. It is used to dig up hard, compact material, usually earth, or to lift heavy loads, such as a sewer box. Basically, the backhoe has three segments: the boom, stick, and bucket. The backhoe is especially suited for digging ditches for sewer and utility lines, digging foundations, and grading. In using the backhoe, the operator parks the tractor and turns the seat around to face the back end. Backhoe loaders are atypical in that during operation the operator will turn completely around and face the rear of the machine away from the driving controls.  
         [0009]     When operating the backhoe loader, the operator selects whether the tractor and/or loader will be used or whether the backhoe will be used. If the backhoe is to be used, then a disk mounted in the front of the rear axle locks the input shaft from the transmission to prevent the backhoe loader from moving forward or in reverse.  
         [0010]     Because the boom, stick, and bucket have a finite length, the backhoe can only dig in a relatively limited area. Therefore, when an operator is using the backhoe to dig a relatively large area, for example a foundation, the backhoe loader must be moved after only a portion of the area is dug out. To move the backhoe loader, the operator must turn the seat around to the front and drive the tractor to the desired location, often only a few feet away.  
         [0011]     Because this process is time consuming, most operators will use the backhoe to push the tractor to the new location. This process is undesirable because the force of the backhoe pushing into the ground will leave the surface uneven and often unusable for the task the backhoe was performing. In addition, such a process can be harmful to the backhoe loader.  
         [0012]     Therefore, it is desirable to be able to move the backhoe loader without having to take the time to turn the seat around or use the backhoe to push the backhoe loader to the desired location. It would be preferable if an existing backhoe loader could quickly modified in a cost effective manner without taking away any of the functions of the backhoe loader.  
       SUMMARY OF THE INVENTION  
       [0013]     The backhoe loader of the present invention allows an operator to move the backhoe loader without having to take the time to turn the seat around or use the backhoe to push the backhoe loader to the desired location. This is achieved by adding rear controls similar to the front controls that are found on every backhoe loader. The front and rear controls are connected to a master switch which determines whether the forward or the rearward controls are used to operate the backhoe loader&#39;s drivetrain and braking system.  
         [0014]     The master switch is connected to the electrical solenoids for the drivetrain shuttle that controls the transmission on the backhoe loader as well as being connected to the backhoe&#39;s hydraulic braking system.  
         [0015]     The rearward controls can be quickly and easily installed on an existing backhoe loader. By adding the rearward controls, an operator can move the backhoe loader to a desired location without having to turn the seat around or use the backhoe to push the backhoe loader to the desired location.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:  
         [0017]      FIG. 1  is a planar side view of a backhoe fitted with a modified drivetrain in accordance with the present invention;  
         [0018]      FIG. 2  is a cross sectional schematic view of the backhoe of  FIG. 1 ;  
         [0019]      FIG. 3  is a planar view of a master switch in accordance with the present invention for use in the backhoe of  FIG. 1 ; and  
         [0020]      FIG. 4  is a cross sectional schematic view of a second embodiment of a backhoe fitted with a modified drivetrain in accordance with the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0021]     In the descriptions that follow, like parts are marked throughout the specification and drawings with the same numerals, respectively. The drawing figures are not necessarily drawn to scale and certain figures may be shown in exaggerated or generalized form in the interest of clarity and conciseness.  
         [0022]      FIG. 1  shows a typical backhoe loader  102  using a powertrain and having loader  118 , tractor  116 , backhoe  104  and stabilizer legs  112 . For example purposes, the backhoe loader  102  is based on a Caterpillar® 420D model. The powertrain is a CATO powertrain.  
         [0023]     At front  120  of backhoe loader  102  is loader  118 . At back  122  of backhoe loader  102  are stabilizer legs  112  and backhoe  104 . Backhoe  104  comprises bucket  106 , stick  108 , and boom  110 . In between back  122  and front  120  is operating station  114  and tractor  116 . Inside tractor  116  is the transmission used to drive and position backhoe loader  102 . The transmission is controlled by controls inside operating station  114 .  
         [0024]      FIG. 2  is a side view of inside of inside operating station  114 . Operating station  114  can be divided into three portions: forward portion  204 , middle portion  206 , and rearward portion  208 . Forward portion  204  is provided for use when backhoe loader  102  is driven or loader  118  is operated. Rearward portion  208  is used when operating the backhoe  104 .  
         [0025]     Middle portion  206  contains the seat, gauges and controls. The gauges provide information such as the fuel level and oil temperature. The controls include, among other known controls, cutoff switch  212  and master switch  210 . Cutoff switch  212  is a safety switch and prevents backhoe loader  102  from being controlled from the controls in rearward portion  208 . Cutoff switch  212  is operationally connected to master switch  210  via electrical wire  234  and, if set to a disengage position, will prevent the controls in rearward portion  208  from controlling backhoe loader  102 .  
         [0026]     Master switch  210  determines if the controls at forward portion  204  control the transmission, or if the controls at rearward portion  208  control the transmission and braking system.  FIG. 3  is a picture of master switch  210  wherein the controls in forward portion  204  will be used.  
         [0027]     Referring again to  FIG. 2 , forward portion  204  contains steering wheel  214 , control lever  216 , accelerator pedal  218  and brake pedal  220 . To operate backhoe loader  102  using the controls located in forward position  204 , master switch  210  is moved to the forward portion controls position (See  FIG. 3 ), the stabilizer legs  112 , if lowered, are raised, and control lever  216  is set to either forward/drive position or reverse position.  
         [0028]     When control lever  216  is set to the forward/drive position, a signal is sent to master switch  210  via forward control wire  228   a . If the position of master switch  210  is in the forward controls position, the signal is transmitted to electrical solenoid  238  via primary forward control wire  234  and transmission  240  of backhoe loader  102  is set for forward motion. If the position of master switch  210  is in the rearward controls position, then the signal is not transmitted to electrical solenoid  238 .  
         [0029]     When control lever  216  is set to the reverse position, a signal is sent to master switch  210  via forward control wire  228   a . If the position of master switch  210  is in the forward controls position, the signal is transmitted to electrical solenoid  238  via primary reverse control wire  236  and transmission  240  of backhoe loader  102  is set for reverse or rearward motion. If the position of master switch  210  is in the rearward controls position, then the signal is not transmitted to electrical solenoid  238 .  
         [0030]     Master switch  210  is operationally connected to backhoe loader&#39;s  102  electrical solenoid  238  via primary forward control wire  234  and primary reverse control wire  236 . Electrical solenoid  238  controls backhoe loader&#39;s  102  transmission  240 .  
         [0031]     As is known in the art, electrical solenoid  238  is an electrically operated, magnetic switching device which controls hydraulic circuits in the transmission by controlling a flow of pressurized hydraulic fluid. A plunger inside electrical solenoid  238  is spring loaded to the closed position and when energized, the plunger is pulled up to allow pressurized hydraulic fluid to flow.  
         [0032]     If backhoe loader  102  is to be moved forward, then control lever  216  is moved to the forward position and accelerator pedal  218  is pressed to give backhoe loader  102  forward momentum. If backhoe loader  102  is to be moved in reverse, control lever  216  is moved to the reverse position and accelerator pedal  218  is pressed to give backhoe loader  102  reverse or backward momentum.  
         [0033]     When accelerator pedal  218  is pressed, a signal is sent to master switch  210  via control wire  228   b . If the position of master switch  210  is in the forward controls position, the signal is transmitted to transmission  240  and backhoe loader  102  is accelerated in the forward or reverse direction depending on the position of control lever  216 . If the position of master switch  210  is in the rearward controls position, then the signal is not transmitted to transmission  240 . Direction is controlled by steering wheel  214 . The brakes are controlled with brake pedal  220 .  
         [0034]     Brake pedal  220  may be a split brake pedal wherein pressing the left partition of brake pedal  220  engages braking system  242  on the left wheel and pressing the right partition of brake pedal  220  engages braking system  242  on the right wheel. If both partitions on brake pedal  220  are pressed equally, then the braking system on the right and left wheel are equally engaged to provide even deceleration. The braking systems on the right and left wheels are hydraulically controlled as is known in the art.  
         [0035]     When brake pedal  220  is activated, hydraulic fluid is pumped into a caliper in brake system  242  via hydraulic line  250 . The pumped hydraulic fluid causes a piston in the caliper to press against the brake rotor. The friction from the piston in the caliper pressing against the brake rotor slows the rotation of the tire and the movement of backhoe loader  102 .  
         [0036]     To control backhoe loader  102  using the controls in rearward position  208 , master switch  210  is moved to the rear portion controls position (See  FIG. 3 ) the stabilizer legs  112 , if lowered, are raised and axle brake  244  locks the input shaft from engaging with the transmission. Rearward portion  208  contains backhoe controllers  226   a  and  226   b , forward accelerator  222  and reverse accelerator  224 .  
         [0037]     If backhoe loader  102  is to be moved forward, then forward accelerator  222  is activated to give the backhoe loader  102  forward momentum. When forward accelerator  222  is activated, an electrical signal is sent from forward accelerator  222  to master switch  210  via electrical wire  230   a . If the position of master switch  210  is in the rearward controls position, the signal is transmitted to electrical solenoid  238  via primary forward control wire  234 . Also, master switch  210 , via electrical wire  248 , sends a signal to axle brake  244  to release the lock on the input shaft thereby allowing the transmission to engage the input shaft and rotate the tires to provide forward momentum for backhoe loader  102 .  
         [0038]     As soon as forward accelerator  222  is deactivated, axle brake  244  locks the input shaft from the transmission. If the position of master switch  210  is in the forward controls position, then the signal is not transmitted to electrical solenoid  238  or to axle brake  244 . Also, if cutoff switch  212  is set to the disengage position, then the signal is not transmitted to electrical solenoid  238  or to axle brake  244 .  
         [0039]     If backhoe loader  102  is to be moved backward, then reverse accelerator  224  is activated to give the backhoe loader reverse or backward momentum. When reverse accelerator  224  is activated, an electrical signal is sent from reverse accelerator  224  to master switch  210  via electrical wire  230   b . If the position of master switch  210  is in the rearward controls position, the signal is transmitted to electrical solenoid  238  via primary reverse control wire  236 . Also, master switch  210 , via electrical wire  248 , sends a signal to axle brake  244  to release the lock on the input shaft thereby allowing the transmission to engage the input shaft and rotate the tires to provide rearward momentum for backhoe loader  102 .  
         [0040]     As soon as reverse accelerator  224  is deactivated, axle brake  244  locks the input shaft from the transmission. If the position of master switch  210  is in the forward controls position, then the signal is not transmitted to electrical solenoid  238  or to axle brake  244 . Also, if cutoff switch  212  is set to the disengage position, then the signal is not transmitted to electrical solenoid  238  or to axle brake  244 .  
         [0041]     In another embodiment shown in  FIG. 4 , forward accelerator  222  and reverse accelerator  224  are located on backhoe controllers  226   a  and  226   b  respectively and can be activated by the fingers of an operator. This is unlike the forward accelerator  222  and reverse accelerator  224  that are located on the floorboard of backhoe loader  102  of the backhoe loader  102  shown in  FIG. 2 . Also, forward accelerator  222  and reverse accelerator  224  in  FIG. 4  may be located on the side of backhoe controllers  226   a  and  226   b  respectively such that they may be activated by pressure from a knee or leg of an operator. Additional locations for the forward and reverse accelerator will be apparent to persons of ordinary skill in the art.  
         [0042]     By using forward accelerator  222  and reverse accelerator  224  the backhoe loader  102  can be moved without having to turn the operator&#39;s seat around and use the controls in the forward portion  204  or use the backhoe  104  to push the backhoe loader  102 .  
         [0043]     By having forward and reverse controls at the rear portion  208  of the backhoe loader  102 , the backhoe loader  102  can be moved without having to turn the seat around or use the backhoe to push the backhoe loader to the desired location.  
         [0044]     Although the invention has been described with reference to one or more preferred embodiments, this description is not to be construed in a limiting sense. There is modification of the disclosed embodiments, as well as alternative embodiments of this invention, which will be apparent to persons of ordinary skill in the art, and the invention shall be viewed as limited only by reference to the following claims. For example, the invention could be applied to other backhoe loaders other than the one described in the detailed description.