Material distributing mechanism

March 8, 1966

3,239,148

S. R. ETNYRE

MATERIAL DISTRIBUTING MECHANISM

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United States Patent Office

3,239,148

Patented Mar. 8, 1966

3,239,148

MATERIAL DISTRIBUTING MECHANISM Samuel R. Einyre, Oregon, HI., assignor to E. D. Etnyre &amp; Co., Oregon, HI., a corporation of Illinois Filed Dec. 26, 1963, Ser. No. 333,519

Claims. (Cl. 239—159)

The present invention relates to a mobile material spreading vehicle and more particularly to the material spreading mechanism.

Trucks for distributing liquid surfacing material on roads have required auxiliary engines to operate pumps which transmit material carried in storage tanks to spray bars from whence the material, often times asphalt, is sprayed on the road. Problems have arisen in applying a preset uniform amount of material on the road surface. First, it is necessary to apply a sufficient amount of material in order to meet strictly enforced specifications. Secondly, it is undesirable to apply an excessive amount of material more than necessary to bind the aggregate, as this not only is an expense out of the distributor’s pocket but also creates “fat” areas presenting patches of slippery pavement.

In the past, spreader units required two men, one man in the cab to drive the truck and a second man to adjust the speed of the engine which powered the pump. In such an operation, if the truck speed is not maintained at an exact value, the material is not applied uniformly at the desired rate since it is difficult to adjust the auxiliary engine speed to compensate for truck speed variations. Attempts to use pumps other than positive displacement units have given unsatisfactory results, even though the flow rates of the pumps can be adjusted, because with variable delivery pumps the quantity of material pumped varies substantially with change in temperature and viscosity of the material. Hence, the pump adjustment does not reliably control the rate of material application.

It is an object of the present invention to provide a material spreading assembly carried on a vehicle for coating road surfaces and the like which uses the vehicle power source and effects a selected material application rate that remains substantially constant even with vehicle transport speed variations.

It is another object of the present invention in accordance with the above to provide a more efficient material spreading vehicle by utilizing the vehicle power source to operate the material spreading assembly thus eliminating the maintenance problems and necessity for additional personnel as well as the weight of an auxiliary power unit.

It is further an object of the present invention in accordance with the above to provide a material spreading assembly which is versatile in that a complete range of material application rates are obtainable from zero to full pumping capacity, while at the same time allowing quick and convenient selection of the zero or full material pumping positions. It is a correlative object of the present invention to provide a material pumping unit which is conveniently usable to either discharge material through a spray bar or feed material to a storage tank for later spraying.

It is an overall object of the present invention to provide an economically manufacturable and easy to maintain material spreading or distributing system which is easily adaptable to standard material distributing vehicles.

Other objects and advantages of the invention will become apparent upon reading the detailed description and upon reference to the drawings in which:

FIGURE 1 is a perspective of a vehicle adapted with an assembly for distributing material on road surfaces embodying the present invention;

FIG. 2 is a schematic of the pumping unit of the material distributing assembly for showing the operation of the pump to remove from or fill up the carrying tank with road surfacing material; and

FIG. 3 is a schematic of the controls for operating the power transmitting means from the vehicle power train to the pump.

While the invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to be limited to the illustrated embodiment but intend to cover the alternative and equivalent constructions which are included within the spirit and scope of the invention as defined by the appended claims.

Turning now to the drawings, shown in FIG. 1 is a vehicle 10 provided with a material distributing or spreading assembly 11 embodying the present invention. The vehicle includes a chassis 12 carrying a tank 13 on its rear portion and having a cab 14 at its forward portion. The cab includes an engine 15α as a part of the vehicle power train 15. Disposed just above a road surface at the rear of the chassis 12 is a spray head 16 provided with a plurality of nozzles 18 through which surfacing material is sprayed onto the road. For pumping material, in the exemplary embodiment asphalt, from the tank 13 to the spray head 16, a pump 19 is provided. In the present instance, the pump 19 takes the form of a positive displacement gear pump. Other types of positive displacement pumps may be used, however this general type of pump which directs all the material at its input to its output can best cope with changes in material properties, i.e. viscosity and temperature.

As is best shown in the schematic of FIG. 2, the pump 19 is positioned in a system 20 of fluid conveying conduits. For pumping material to the spray head 16 as during normal surfacing operation, the pump 19 is connected to the tank 13 by an input conduit 21. An exhaust conduit 22 is provided on the other side of the pump to connect the latter with the spray head 16 to complete the material flow line to the spray head. Both conduits are provided with two-way valves 23, 24, respectively for by-passing the spray head 16 to convey material directly between the tank 13 and a connector conduit 25. In that instance the flow line is completed between the conduit 25 and the tank 13 through valve 24 by a pipe 26 coupling the latter with the tank 13. The by-pass operation of the system 20 is explained subsequently.

In accordance with the present invention an infinitely variable drive having a complete range of speed ratios for selectively operating the pump 19 from vehicle power train 15 is provided to effect a uniform predetermined rate of material distribution. In the present instance the infinitely variable drive takes the form of a hydrostatic transmission system 28. The system includes a pump 30 and a motor 31. The pump 30 is coupled to the power train 15 through a power-take-off drive 32 and a power shaft 33. In response to operation of the p.t.o. drive 32, the pump 30 effects hydraulic fluid flow through a pair of hydraulic lines 34, 35 thereby transmitting drive to the motor 31 which is coupled to the positive displacement pump 19 through a shaft 36. The pump 30 includes a reaction plate (not shown) which is adjustable by the control assembly 37 to both vary the rate as well as reverse the direction of flow of hydraulic fluid from the pump 30. Selective control of the fluid flow thus controls the rotational speed and direction of the output shaft 36 of the hydraulic motor 31. The pump 30 is fully adjustable to vary the hydraulic fluid flow in the lines 34, 35 between zero and maximum flow, thus providing a complete range of speed ratios for application of surface material at predetermined rates. It is clear that the hydraulic motor 31 responds proportionately to variations in speed of the power train 15 because the pump 30 is

3,239,148 directly coupled thereto. Accordingly, if the power train speed and thus the vehicle speed are increased, the motor 31 speeds up to increase the quantity of fluid delivered at the spray bar 16 assuring a constant rate of material application to the surface. The application rate can be selectively adjusted by operating control assembly 37 which moves the pump reaction plate to change the speed ratio between the p.t.o. shaft 32 and the motor output shaft 36. In summary, the variable drive 28 provides a versatile drive transmitting means from the power source or train 15 to the positive displacement pump 19 for selecting a drive-speed ratio between zero drive and full drive.

Rate of material application is selected by manually operating the control assembly 37. As best shown in FIG. 3, in the present instance the assembly includes a Bowden wire 40 connected through a lost motion device 41 and a control linkage assembly 42 to the hydraulic pump 30. The Bowden wire 40 is a coaxial cable having a manually movable control cable 43 with one end connected to a shaft 44 on which is mounted a knob 45 and the opposite end carrying a retainer washer 46 slidably received in a cylinder 48 of the lost motion device 41. Downward movement of the knob 45 forces the retainer washer 46 against an end wall 48α of cylinder 48 and thereby moves the cylinder longitudinally. Pulling up on the knob effects longitudinal movement of the cylinder 48 in the opposite direction with the washer 46 acting through a spring 47 against an annular retainer 486 to move the cylinder in the opposite direction. The retainer 486 has a central opening 53 to slidably receive control cable 43. The lost motion device will be further explained in subsequent paragraphs of the present application in relation to another feature of the invention allowing easy selection of maximum operating speed for pump 30.

The control linkage assembly 42 couples the lost motion device 41 to a pump control arm 54. In the exemplary embodiment the assembly 42 includes a rod 49 suitably fastened at one end to a cylinder end wall 48α for example by a weld connection, and pivotably attached at the opposite end to a lever 50 fulcrumed at a point 51. Longitudinal movement of the rod 49 in response to actuation of the cylinder 48 pivots the lever 50 and moves a link 52. The latter is coupled to pump control arm 54 which itself effects positioning of the reaction plate in hydraulic pump 30. The hydraulic pump is thereby set to pump a predetermined quantity of fluid to hydraulic motor 31 and operate the positive displacement pump 19 at a speed to pump surfacing material at a desired rate ordinarily measured in gallons per minute.

An operator must adjust the position of knob 45 to obtain a desired rate of applictaion of surfacing material. The knob 45 will select the operating speed for pump 19 so as to force a selected number of gallons per minute through the nozzles 18 of spray bar 16. The application rate to the road surface depends upon the width of the spray bar 16 and the speed of the vehicle 10. For displaying to the operator the gallons per minute being pumped, a pump tachometer 62 is provided in the cab 14. A bitumeter 63 transposes the engine speed into speed of the vehicle in feet per minute. The operator can use a computator (not shown) or other scale to get a reading of what pumping rate is necessary for a particular distribution speed and a particular spray bar width to obtain a desired material application rate. Once the pump is set, engine speed variation does not affect the application rate.

To select a setting for the knob 45 which will provide a desired surfacing material application rate, the valves 23, 24 respectively are positioned so that the pump 19 will recirculate the surfacing material from tank 13. By operating the pump with the valves positioned to recirculate, the tachometer 62 shows the gallons per minute pumped with the knob 45 at a particular setting. Thus, when the lower valve 24 is positioned to direct material from pump 19 to the spray bar 16, the selected gallons per minute of surfacing material is pumped to the spray bar to spread material on the surface at the desired rate.

To fix the knob 45 in the selected operating position, as shown in FIG. 3, a spacer 55 is threaded on an upright 5 stud 56 which is locked in position by a knurled locking nut 57 also threaded on the stud 56. In the pulled-out or “up” position (see FIG. 3), the knob 45 sets the hydrostatic pump 30 in neutral. When knob 45 is pushed downward and in contact with the spacer 55, the hydro30 static pump 30 is set to power the surfacing material handling pump 19 at a selected speed. The setting of the spacer 55 can be adjusted, and thus the position to which knob 45 can be pushed down is also adjusted by turning the locking nut 57 so that the spacer and locking 15 nut are separated, then threading the spacer to a new position. The locking nut 57 is then threaded so that it engages the spacer and the two are locked together again. Thus, a fixed operating position for the knob 45 is provided so that it can be conveniently moved from the 20 pulled-out or hydrostatic pump 30 off position to the pushed-in or hydrostatic pump 30 drive transmitting position.

Summarizing operation of the control assembly, the knob 45 which is ordinarily located in the vehicle cab 25 is pulled upwardly as shown in FIG. 3 thereby placing the pump 30 in the off position or zero speed ratio position and power is not transmitted from the power train 15 to the positive displacement pump 19. By pushing the knob 45 downwardly the hydraulic pump 30 is selec30 tively adjusted to a position so that the hydraulic motor 31 operates the positive displacement pump 19 at a speed which effects a predetermined rate of surfacing material application, i.e., a certain number of gallons of surfacing material are forced through the pump 19 to the spray bar 35 16. Adjusting the spacer 55 fixes the adjusted position to which the manually operable knob 45 can be pushed down and thus the selected operating position for hydrostatic pump 30 transmitting drive to the material handling pump 19. For example, turning the spacer 55 on the threaded 40 stud 56 so as to direct it upwardly closer to knob 45 positions the reaction plate in the hydrostatic pump 30 so that a smaller portion of the speed from the p.t.o. shaft 32 is transmitted to the positive displacement pump 19. In other words, the speed ratio is further reduced from the maximum ratio of 1 to 1. Of course, turning the 45 spacer 55 in the opposite direction, downward in FIG. 3, provides increased speed ratios with the pump 19 operating more closely to the speed of the p.t.o. shaft.

It is another feature of the present invention that the pump 19 can be operated at a maximum speed from the 50 power train 15 without affecting the position of the control assembly setting means, in the present instance the knurled nut 55. For this purpose the lost motion device 41 and a set of controls 56, 58 respectively are provided for overriding the position of the control assembly knob 55 45. These are coupled to the fulcrumed lever 50 by respective chains 64, 65. Explaining the operation of the lost motion device and override controls and turning to the manual control 56 adapted for controlling pump operation from the rear of the vehicle, the control 56 in60 eludes a knob 59 and a control cable 60 connected through the chain 64 to the fulcrumed lever 50. Pulling on knob 59 effects pivoting of the lever 50 about point 51 to operate arm 54 which adjusts the reaction plate in pump 30 for increased output pump operation. The lever 50 is 65 allowed to pivot even though the knurled nut 55 remains stationary thereby holding the control cable 43 to a fixed position because the lost motion device cylinder 48 can move relative to the control cable 43 upon compression of the spring 47. As was explained previously, the spring 70 retainer 486 is provided with a central opening 53 to allow relative movement between the retainer and the control cable. The operation of the override control, control 58, is the same as that of control 56 except that it is installed in the cab of the vehicle and is fixed to the lever 75 50 on the opposite side of the fulcrum point 51. Because

3,239,148 of the chain connection between the respective controls 56, 58, and lever 50, one override control can be operated without affecting the other.

For transmitting material between the connector conduit 25 and the tank 13 the valves 23, 24, respectively, are turned clockwise so as to bypass an upper portion 21« of input conduit 21 and the spray head 16. Material is thereby pumped through pipe 26. This adjustment of the fluid conveying systm 20 is desirable when it is necessary to fill the tank 13 or to empty it.

The unit is returned to its normal operating position in which material is sprayed from the nozzles 18 by releasing the respective controls 56, 58 and allowing the position of knob 45 to control operation of the hydrostatic transmission pump 30. At the same time the respective valves 23, 24 are turned counterclockwise so as to complete a flow line between the tank 13 and spray head 16 through input conduit 21, positive displacement pump 19 and exhaust conduit 22.

In connection with the operation of the hydrostatic transmission 28, there is shown in FIG. 1 an overflow reservoir system 61 to recover leakage hydraulic fluid from the pump 30 and motor 31 respectively. The detailed operation of the latter as well as the reservoir system are not set forth herein as the present invention is concerned only with the general operating principles of the hydrostatic transmission. In connection therewith it is emphasized that other transmission systems could be used which provide an infinite selection of drive-speed ratios to operate a positive displacement pump.

The schematic of FIG. 2 shows an exemplary valving installation for practicing the present invention. It is, of course, within the knowledge of those skilled in the art to adapt the installation to perform operations ancillary to effecting uniform application of surfacing material to roadways and the like simply by providing additional valves and conduits.

It is clear from the foregoing that the present invention provides an efficient and easily adaptable system for effecting uniform application of surfacing material to roadways and the like. The system has the advantage of reducing both the manpower required in the past as well as the weight and -cost of auxiliary equipment. These economical features have been achieved in addition to obtaining improved results by effecting uniform application of surfacing material even with variations in transport speed of the vehicle.