Drive on Roller Brake Dynamometer Shuttle System, Trailer and Method of Using Same

A vehicle brake testing dynamometer which is portable presents a problem at the location of use as to positioning the dynamometer on the road surface such that vehicles can be driven onto it for brake testing. The length of the dynamometer corresponds generally to the width of the vehicle which will be driven onto it. The dynamometer when transported must be turned such that its longitudinal axis is parallel to the direction of travel to minimize its width and allow it to be hauled on a trailer. The dynamometer normally does not carry its own transport wheels as it needs to sit solidly on the ground when being used to test truck brakes.

Thus, among the problems to which this invention is directed is that of loading and unloading the dynamometer on a trailer and when at a brake testing location the positioning of the dynamometer so that trucks may be driven onto it for brake testing.

The patent to Vaughn, et al. 5,148,703, Sep. 22, 1992, discloses a vehicle inspection trailer wherein the trailer wheel system is pivotable between a transport trailer position to a brake testing position where the dynamometer is on the ground and the trailer wheels are pivoted out of the way. This system combines the dynamometer and trailer into a single unit but has no means of turning the dynamometer once placed on the ground so that it is transverse to the roadway and is in a position for trucks to drive onto it. My invention provides a system which meets these needs.

This invention involves a drive on roller brake dynamometer, a trailer for loading and unloading and the method of use. The dynamometer has shuttle wheels which are adapted to be raised and lowered at each end of the dynamometer. The shuttle wheels may be driven forwardly, rearwardly or in opposite directions to pivot and position the dynamometer as desired. The shuttle wheels are in continuous engagement with the dynamometer rollers and thus rotate freely when raised and engage the ground when lowered to move the dynamometer as desired. Bi-directional controls for the rollers effect the three positioning movements.

The trailer for transporting the dynamometer has a bed which tilts to position the rear end on the ground for loading and unloading. An endless chain extends around sprockets at the front and rear ends of the bed and includes a tongue which extends from the chain to an end of the dynamometer for pulling the dynamometer on and off the tilted bed. The chain is positioned in the top surface of the bed and the dynamometer frame slides along the trailer bed frame when being loaded and unloaded.

The method of use of the trailer and shuttle system includes positioning the dynamometer lengthwise on the trailer by pulling it onto the trailer bed through use of the tongue connected to the chain in the bed of the trailer. When the test site has been reached, the bed is tilted downwardly at the rear and the conveyor chain on the bed is operated in the opposite direction to pull the dynamometer off the bed and onto the ground. When the dynamometer is free of the trailer the rollers are operated which in turn drive the shuttle wheels. A power cylinder is operated to pivot the shuttle wheels into ground engagement thereby allowing the dynamometer to be moved forwardly, rearwardly or rotated by operating the shuttle wheels at each end of the dynamometer in opposite directions. Ordinarily the dynamometer will be rotated one quarter turn to position it transversely of the roadbed thereby allowing vehicles to be driven onto it. When the dynamometer is to be transported again, the step by step process is reversed wherein the shuttle wheels are again lowered into engagement with the ground and then the rollers are operated to position the dynamometer parallel to the direction of travel and at the rear of the trailer. The tongue on the trailer bed conveyor chain is connected to the dynamometer frame and the conveyor chain is operated to pull the dynamometer onto the bed of the trailer whereupon it is tilted to the raised horizontal position making it ready for being transported. The hydraulic power system of the dynamometer is connected via quick-couplers to power the chain drive motor.

FIG. 1 is a perspective view of the roller brake dynamometer in its position ready for a truck to be driven onto it for testing the truck brakes.

FIG. 2 is a perspective view showing the dynamometer on a trailer to be used for transporting the dynamometer between vehicle brake test locations.

FIG. 3 is a top plan view of the trailer.

FIG. 4 is a side elevation view thereof with the dynamometer on the trailer.

FIG. 5 is a partial top plan view of the dynamometer.

FIG. 6 is a cross sectional view taken along line 6--6 in FIG. 5 showing the dynamometer in its raised position with the shuttle wheels engaging the ground.

FIG. 7 is a view similar to FIG. 6 but showing the dynamometer lowered onto the ground with the shuttle wheels raised off of the ground.

FIG. 8 is a cross sectional view taken along line 8--8 in FIG. 3 showing the conveyor chain on the bed of the trailer and the lock pin for holding the trailer bed in a raised position.

FIGS. 9-14 are side elevational views showing the dynamometer and step-by-step positions between being loaded on the trailer and unloaded onto the ground.

FIG. 15 illustrates the dynamometer unloaded onto the ground and being rotated a quarter turn for being positioned to allow a truck to be driven on a single lane of a road.

FIG. 16 is a view similar to FIG. 15 but showing the unloading and positioning steps completed with the dynamometer ready for testing vehicle brakes and the trailer being ready to be pulled out of the way.

The roller brake dynamometer of this invention is referred to generally in FIG. 1 by the reference numeral 10 and is shown in FIG. 2 loaded on a trailer 12 for hauling between truck brake testing sites.

The dynamometer 10 includes an elongated frame 14 having first and second wheel engaging rollers 16 and 18 spaced apart in end to end relationship for engagement with wheels at opposite ends of a common truck axle. A second set of rollers 20 and 22 are also in end to end relationship and spaced from the first set of rollers 16 and 18 to also engage the truck wheels such that one wheel is engaged by rollers 16 and 20 and the other wheel is engaged by rollers 18 and 22. Hydraulic motors 24 rotate the rollers which have knurled surfaces for engaging the truck tires.

The shuttle wheel system is shown in FIGS. 5-7 and includes a shuttle wheel 26 associated with each roller. The shuttle wheels 26 are carried on the lower ends of arms 28 which pivot about an axis common to the longitudinal axis of rotation of the rollers. The ends of the arms 28 opposite the wheels 26 are engaged by an actuation rod 30 which interconnects side by side arms 28 and in turn is connected to a rod 32 connected to a power cylinder 34 pivotally mounted through a hinge bracket 36 to the frame 14. It is seen in FIGS. 5-7 that the shuttle wheels 26 continuously engage the knurled rollers and thus the shuttle wheels rotate whenever the rollers are rotating. When the dynamometer frame 14 is resting on the ground, as is the case when it is being used to test vehicle wheel brakes, the shuttle wheels 26 are raised off the ground and rotate freely as the rollers rotate when driving the vehicle wheels. Operation of the power cylinder 34 as seen in FIG. 6, pivots the shuttle wheels lifting the machine frame off the ground so that the entire frame is by its rollers resting on the shuttle wheels, thereby allowing further rotation of the rollers to drive the shuttle wheels 26 and cause the dynamometer to move forwardly or rearwardly or rotate about its own center axis if the rollers 18 and 22 are driven in opposite directions from the rollers 16 and 20 at the opposite end.

When it is desired to move the dynamometer 10 to another test location, the oppositely disposed set of ramps 40 associated with each set of rollers are folded upwardly to the position of FIG. 2 and held in this position by a strap 42.

The loading of the dynamometer 10 onto the trailer 12 is done in a reversed step by step procedure from the unloading as illustrated in FIGS. 9-16 which will be described later.

The trailer 12 is best shown in FIGS. 3, 4 and 8 and includes a bed frame 44 pivoted to a trailer frame 46 about an axis 48. The trailer frame 46 is carried on wheels 50 and includes a trailer tongue 52. A spring loaded pin 54 mounted on the trailer frame 46 engages an opening 56 in an upstanding member 58 on the forward end of the bed frame 44 to hold the bed frame in a horizontal raised position.

An endless conveyor chain 60 extends along a rail 61 lengthwise of the trailer bed frame 44 along the longitudinal center and engages sprockets 62 and 64 at the front and rear ends respectively of the rail 61. The chain 60 includes a top section 60A and a bottom section 60B. The top chain section 60A includes a connecting link 66 adapted to engage the forward end of a tongue member 70 having its rear end in engagement with the forward end 72 of the dynamometer frame 14 as seen in FIG. 4. A hydraulic motor 74 is located on the bed frame 44 as seen in FIG. 3 and powers the endless conveyor chain 60 through a shaft 76.

A control console 78 is positioned at one end of the dynamometer 10 and includes an engine (not shown) for driving a hydraulic pump in turn connected by the lines 80 as seen in FIG. 15 to the hydraulic motor 74 on the trailer 12.

The unloading of the dynamometer 10 as shown in FIGS. 9-16 starts with the dynamometer on the trailer as seen in FIG. 9 in a transport position. The trailer bed frame 44 is first pivoted to its down position as seen in FIG. 10 by releasing the pin 54 and moving dynamometer slightly rearward. A motion dampening cylinder attached to bed frame and trailer frame controls pivoting speed seen in FIG. 4. Next, the conveying chain 60 is operated rearwardly to push the dynamometer 10 off the trailer bed frame 44 through pressure applied through the tongue 70 as seen in FIGS. 11-14. A roller 82 at the rear end of the dynamometer 10 engages the ground 38 first and raises the dynamometer off the trailer bed frame 44 as seen in FIGS. 11 and 12. Continued rearward movement of the conveyor chain 60 moves the dynamometer 10 totally onto the ground as seen in FIG. 14 at which time the tongue 70 and hydraulic lines may be disconnected from the dynamometer allowing the trailer 12 to be moved out of the way.

As seen in FIGS. 15 and 16, the loading and unloading operation is seen on a single lane road bed and the dynamometer 10 is now rotated one quarter turn between the solid line position in FIG. 15 to the transverse dash line position wherein it is ready to receive vehicles for brake testing purposes. In FIG. 16 the unloading operation is complete and the dynamometer 10 is ready to be operated to test vehicle brakes and the trailer 12 is ready to be moved away. When the testing operation has been completed, the reverse procedure may be followed for loading the dynamometer 10 back onto the trailer 12 for being moved to the next test site.