US1717704A - Paving machine - Google Patents

Description

June 18, 1929. F, GREENE 1,717,704

PAVING MACHINE Original Filed Nov. 23, 1921 6 Sheets-Sheet l I N V EN TOR.

FPEO 5. spas/v5 A TTORN E Y June 18, 1929. F, GREENE 1,717,704

PAVING MACHINE Original Filed NOV. 23, 1921 6 Sheets-Sheet 2 FIG- 4- FIG- 2 INVENTOR.

FRED E. GPfE/V A TTORNEY June 18, 1929. F. E. GREENE PAVING MACHINE Original Filed Nov. 23, 1921 6 Sheet -Sheet.

INVENTOR.

FRED 1 GPE/V,

BY W

A TTORNY F. E. GREENE PAVING MACHINE June 18, 1929.

Original Filed Nov. 23, 1921 6 Sheets-Sheet INVENTOR.

FPED 1 GPE/V.

ATTORNEY June 18, 1929. F. E. GREENE 1.717.70

PAVING MACHINE Original Filed Nov. 23, 1921 6 sh ets-sh t 5 INVENTOR.

FPEO 5 GPE/V ATTORNEY June 18, 1929. F. E. GREENE 17.704

PAVING MACHINE Original Filed Nov. 23, 1921 a'sheets-sheet 6 IN VENTOR FPED 5. apes/v5.

ATTORNEY Patented June 18, 1929.

' UNITED STATES PATENT OFFICE.

FRED E. GREENE, 0F ESCALON, CALIFORNIA, ASSIGNOR TO BESSIE B. GREENE, 0]! BERKELEY, CALIFORNIA.

PAVING MACHINE.

Application filed November 23, 1921, Serial No. 517,186. Renewed May 1, 1929.

This invention relates to machines for mixing, cooking and laying paving materials.

The object is to provide a. self-propelled unitary structure by means of which the various ingredients enteringinto a finished paving material can be mixed in proper proportions, heated and cooked uniformly and delivered at the desired place along the road bed at theproper temperature for laying.

It is essential to the success of any paving material that it be uniform as to the proportion of ingredients, temperature and length of cooking and temperature at which the same is laid. Lack of uniformity in any of these respects will injuriously afiect the finished paving. In other words, unless the material be of uniform texture or density throughout and laid at uniform temperatures the contraction and expansion will be uneven and likewise the strength and resistance of the material will be unequal so that in time cracks, depressions or ridges will develop which under the shocks of traffic will cause early deterioration of the paving.

In and by the present invention I provide a self-propelled vehicle or train on which is mounted a mixing and cooking drum for the combined ingredients. The particular paving material which the present machine is designed to produce consists preferably of asphalt, aggregate and limestone. On the self-propelled machine is arranged a large heating-vat to prepare the asphalt. The asphalt is'maintained at such a degree of temperature as to keep it in a fluid state and'a pump is provided for keeping up a circulation of the; liquid asphalt throughout the vat. Adjacent the intake end of the mixing drum is provided a measuring tank into which liquid asphalt is pumped from the heating vat. Also adjacent the end of the cooking drum is a large measuring vessel to contain the aggregate and limestone and said measuring vessel is supplied by.

means of an elevator. The limestone is dum ed into. a hopper leading directly to the e evator, and the aggregate, consisting of crushed rock and sand, or sand and gravel is fed to the elevator from a preheating drum. The purpose of this preheating step is to thoroughly dry the aggregate and raise the temperature thereof to facilitate assimilation with the asphalt. The preheating drum is provided with a novel heating arrangement and the material isfed there:

through in a manner to insure uniform heating. When the measuring vessels at the intake end of the drum are filled with the desired proportions of ingredients both vessels are opened to discharge their contents into the mixing drum. This mixing drum is provided with a novel mechanism for thor oughly agitating the mixture and a heating device is provided for raising the temperature of the mixture to a comparatively high temperature, say for instance 250 to 300 degrees. After the mixture has been thoroughly agitated and cooked for a suflicient length of time the material is discharged from the opposite end of the drum and falls directly to the ground. At this time the vehicle on which the mechanism is mounted is driven along at such a rate of speed as to distribute the material where needed. In this manner I obtain a superior paving material and one which can be laid at a temperature of 300 degrees or over.

One form which my invention may assume is exemplified in the following description and illustrated in the accompanying drawings, in which:

Figure 1 shows a side elevation of a machine embodying my invention.

Fig. 2 shows a front elevation of the same.

Fig. 3 shows a similar View with a por- 3 tion of the forward end broken away.

Fig. 4 shows a rear elevation of the machine.

Fig. 5 shows a side elevation opposite to that shown in Fig. 1.

Fig. 6 shows a sectional view of the preheating drum.

Figs. 7, 8 and 9 show cross sectional views taken on the lines correspondingly numbered of Fig. 6.

Fig. 10 shows a sectional view partly in elevation of the cooking and mixing drum.

Figs. 11 and 12 show cross sectional views of the same taken on the lines ll11 and 12-12, respectively.

Fig. 13 shows a detail view in elevationof the weighing mechanism for the various ingredients.

Referring to Fig. 1, the entire mechan sm is shown as mounted on a frame 10 having tractor wheels 11 and steering wheels 12 at opposite ends. A motor 13 is shown at one end of the frame adjacent the tractor wheels, and steering and control apparatus 14 are arranged at the opposite end, which for convenience will be-designated as the front end of the machine.

At the front end of the frame is arranged a cooking and mixing drum 15, the details and construction of which are shown in Figs. to 12, inclusive. It includes an in closed drum 16, revolubly mounted by means of peripheral tracks 17, upon rollers 18. The drum is driven by means of a ring gear 19 arranged on the rear end and meshing with a drive pinion 20, the latter being operated by suitable transmission mechanism 20 ex tending rearwardly of the main frame and operatively connected with the motor or power plant 13.

The inside of the'drum has longitudinally extending rods 21 fastened to the opposite end walls and carrying inclined blades 22 at intervals. There are three sets of rods and blades and the. latter are so arranged relatively that they describe an interrupted spiral or worm, tending to move the material rearwardly. The drum is inclined downwardly at its forward end so that the natural tendency is for the material to pile up at the forward end, but the action of the blades is such as to move the material rearwardly and thus a longitudinal movement is imparted to the material in addition to the other movement caused by the rotation of the drum. In this manner a thorough agitation of the mixture is brought about.

At thefor-ward endof the drum which constitutes the discharge end there are arranged three vanes 23, so shaped as to scoop the material up as the drum rotates and feed the same to the discharge opening. This opening is normally closed by a plate 24 rotatably mounted upon a crank arm 25. The shaft 26 for the crank arm is journalled on standards 27 fastened to the main frame and a lever 26 is provided for raising and lowering the door and locking the latter in a closed position. When the door is closed it rotates with the 'drum and keeps the mixture from discharging. When, however, the material has been; sufficiently mixed and cooked the door is raised, whereupon the material is free to be discharged, falling directly to the ground along the chute 2.7. The vehicle at this time is driven rearwardly.

Around the drum 15 is arranged a housing 28 having a compartment 28 beneath the drum, in which is located an oil burner 29.

The housing is spaced from the walls of the drum so as to permit theheated air to pass between, and a chimney 30 is arranged at the top of the housing for the escape of the products of combustion.

Near the center of the frame 10 and at the rear end of the cooking and mixing drum are upright supporting members 31 on one side of which is arranged an asphalt measuring tank 32 carried on a scale-beam 33. Between the uprights is a measuring tank 34 for the aggregate and limestone, this tank being also supported on a scale-beam 35. The asphalt tank has adischarge pipe 36 opening into a chute 37, which latter communicates with the interior of the mixing drum at the rear end thereof. Also the tank 34 has a gate 38 at its lower end to discharge the contents into said chute.

The asphalt measuring tank is supplied from a heating vat 39 mounted centrally on the frame 10. This vat has a heating apparatus 40 beneath it. To fill the heating vat from an outside source and keep the liquid asphalt in circulation I provide a pump 43. This pump has its intake connected with the bottom of the vat or optionally with an outside source. A pipe 44 extends from the discharge of the pump back to the vat, with a branch 45 communicating with the measuring tank, there being suitable valves for controlling the circulation of the liquid asphalt as desired.

The measuring tank 34 is supplied from an elevator 46 arranged at one side of the mainframe as best shown in Fig. 5. The lower end of the elevator has a hopper 47 arranged near the ground so that limestone or the like may be conveniently dropped therein. a chute 48 leading from the discharge end of a preheating drum 49. I This drum is mounted at the rear end of the machineand is intended to receive aggregate such as sand, gravel, etc., for reheating the same. The material is supp ied to the drum. by means of an elevator 50 carried at the rear end of the frame and having a hopper 51 conveniently disposed to permit the material to be dumped therein. heating drum are best shown in Figs. 6 to ,9, inclusive. This drum includes an outside cylinder 52 having peripheral. tracks 53 rotatably mounted on ro1lers- 54,the latter 'being driven by a suitable transmission mechanism 55 operatively' connected with the power plant; There'is an inside cyhnder 56 carried coaxially with the outside cylinder and having a burner 58 arrranged at its rear end. The front'end of the inside cyl-.

inder is open so as to permit the heated air-to pass betweenv the two cylinders. There is a discharge flue 59 at the rear endlof-the drum leading from the space between the two cylinders so that the heated air makes a complete circulation longitudinally of the drum before passing out through the flue 59.

The inside cylinder has radial vanes 60 on its exterior and the outside cylinder has serrations or pockets 61 on its interior. The sand and gravel lies between the two. cylinders and is picked up by the pockets on the outside cylinder and carried approximately one-half revolution. It then falls onto the outsidecylinder and is carried by the vanes Communicating with the hopper is The details of the pre-- 60 about one-third revolution when it again drops to the bottom of the outside cylinder. The drum is slightly inclined downwardly at the forward end of the machine so that the material is gradually moved forwardly as the drum rotates. The discharge opening is located at the forward end of the drum and material is directed thereto by vanes 62 fastened to the end wall of the drum. The discharge of the material is preferably continuous and the heating arrangement is such that the material will be sufficiently heated as it passes from one end to the other of the drum.

For larger machines than that here shown it may be desirable to construct the same in two separate units, arranging the cooking and mixing drum on one chassis, and the remainder of the mechanism on another chassis.

Various other changes in the construction and arrangement of the several parts herein shown and described may be employed without departing from the spirit of my invention as disclosed in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a machine for preparing paving materials, a portable frame, a rotatable drum arranged longitudinally thereon for mixing the combined materials, said drum having a discharge opening in one end, a closure for the discharge opening rotatably mounted on a stationary support, said drum being inclined downwardly towards its discharge end, and having on its interior spirally arranged vanes tending to move the material away from the discharge end, whereby the material is given a longitudinal as Well as a rotary motion, and means for heating said drum, and means for delivering material from the mixing drum directly on to the ground while the vehicle is in motion.

2. In a machine for preparing paving materials, a portable frame, a rotatable drum arranged longitudinally thereon for mixing the combined materials, said drum having a discharge opening in one end, a closure for the discharge opening rotatably mounted on a stationary support, said drum being inclined downwardly towards its discharge end and having on its interior spirally arranged vanes tending to move the material away from the discharge end, whereby the material is given a longitudinal as well as a rotary motion, and means for heating said drum, said heating means comprising a casing surrounding the drum and a burner beneath said drum arranged within the said casing, and means for delivering material from the mixing drum directly on to the ground While the vehicle is in motion.

FRED E. GREENE.

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