US2295519A

US2295519A - Apparatus for surfacing roads

Info

Publication number: US2295519A
Application number: US351302A
Authority: US
Inventors: Arnold S Millikin; Henry M Pickard
Original assignee: Jaeger Machine Co
Current assignee: Jaeger Machine Co
Priority date: 1940-08-04
Filing date: 1940-08-04
Publication date: 1942-09-08
Anticipated expiration: 1959-09-08

Description

p 8, 1942. A. s. MILLIKIN'; arm.

APPARATUS FOR SURFAQKING ROADS Filed Aug. 4, 1940 4 Sheets-Sheet 1 INVENTORS.

' Arnold 5.Millik|n.

Henry M. Pickard.

Mm WWW I A TTORN 5 p 1942- A. s. MlLLlKlN ETAL 2,295,519

APPARATUS FOR SURFACING ROADS Filed Aug. 4. 1940 4 Sheets-Shet 2 [N VENTORS. Arnold S.Mil|ikm.

Henry M.Pickard BY 1M m,

A TTORNE Y5 p 8, 1942. A. s. MILLIKIN ETAL APPARATUS FOR SUI (FACING ROADS 4 Sheets-Sheet 3 Filed Aug. 4, 1940 as 8i Fig 7 eke [I v r m s c m a M. N Y m m a w H A p 8, 1942. A. s. MlLLlKlN El'AL 2,295,519

I APPARATUS FOR SURFACING ROADS Filed Aug. 4. 1940 4 Sheets-Sheet 4 INVENTQRS.

Arnold atg dlikir anl'y It: or

A TTORNE Y5 reamed an. 8, 1942 APPARATUS FOR SURFACING ROADS Arnold S. Millikin and Henry M. Pickard,

Columbus, Ohio, assignors to The Jaeger Machine Company, Columbus, Ohio, a corporation of Ohio Application August 4, 1940, Serial No. 351,302

14 Claims.

Our invention relates to apparatus for surfac ing roads. It has to do, more particularly, with.

apparatus for producing a smooth and level surface on a layer of material which is being applied to an old road surface or to a rough graded surface. 'The invention is useful with various materials such as bituminous mixes, concrete, et cetera.

One of the objects of our invention is to provide apparatus for surfacing roads which is of such a nature that the irregularities of the surface being covered by the material will be averaged out in the finished surface so that the finished surface will be free of sharp irregularities or bumps.

Another object of our invention is to provide apparatus for surfacing roads which is of such a nature that it may be used in resurfacing old road surfaces to produce a surface having the same general grade as the old surface with the sharp irregularities thereof eliminated or to-produce a surface having an entirely difierent grade from the surface being covered.

Another object of our invention is to provide an apparatus for surfacing a road which includes a finishing member adapted to smooth and level the surface of the material being applied, the

apparatus being of such a nature that the finishing member resting on the layer of material will not support any substantial weight of the machine in order to prevent undue compaction of the layer of material so as not to retard the curing or setting of the material.

Another object of our invention is to provide apparatus of the type indicated which is very effective but which is relatively simple.

The apparatus which we preferably employ consists of two main units. These units are a material feeding unit and a material finishing and leveling unit. The material feeding unit may be of any suitable type and is carried by suitable traction means which operate upon the sub-grade .or the old road surface being covered. The finishing unit is'assoclated with the material feeding unit in such a manner that relative vertical movement between these two units is permitted as the apparatus moves along. The finishing unit embodies a transversely extending screed member which is disposed behind the material feeding unit. The material feeding unit serves to feed and deposit the material in front of the screed member on the surfacebeing covered, and the screed member acts to level off the material and to smooth it.

feeding unit operates on the rough sub-grade or old road surface, it will be moved vertically because of such irregularities. To reduce such movement, the unit is preferably carried by relatively long caterpillar traction elements. These substantially prevent small irregularities from affecting this unit. However, the larger and sharp irregularities in the surfacebeing covered will still produce some vertical movement of this unit.

This vertical movement of the material feeding unit has a tendency to move the screed of the finishing unit, which is pulled along behind the feeding unit, vertically and thereby cause the sharp irregularities of the surface being covered to be reflected in the finished surface. We pro- I vide means connected with the finishing unit and with the feeding unit for automatically controlling the level of the screed member so as to average out the sudden rises and depressions of go the surface being covered as reflected in the finished surface. In other words, if the surface being covered has sharp rises and depressions, these will be reflected in the finished surface but will be gradual rises and depressions so as to be almost unnoticeable. Consequently, the surface produced by our apparatus will be a very smooth riding surface.

The preferred embodiment of our invention is illustrated in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:

Figure 1 is a perspective view of a machine embodying the principles of our invention.

Figure 2 is a side elevation of the machine.

Figure 3 is a rear view of the finishing unit showing the hydraulic means for controlling the elevation of the screed associated therewith.

- Figure 4 is a diagrammatic view of our machine showing it in operation and illustrating how small irregularitiesof the surface'being covered have substantially no effect on the machine.

Figure 5 is a similar view illustrating how the machine functions when the material feeding unit starts to pass up over a sharp bump.

Figure 6 is a vertical sectional view taken through one of the automatic control valves which is associated with the hydraulic mechanism that automatically controls the level of the screed.

Figure '7 is a similar view but taken at right angles to that of Figure 6.

Figure 8 is a vertical sectional view taken through a check valve which is also associated with the hydraulic system that controls the level It will be apparent that since the material of the screed;

Figure 9 is a perspective view of the rear end of our machine illustrating how'the means for erably has been previously mixed, and to deposit it on the surface being covered in front of the unit 2. The unit 2.is adapted to level off and surface such material.

The unit I may be of any suitable type. The

' specific structure of this unit does not form a part of the present invention. It is merely necessary that it be of such a nature that it will receive the material and feed it to the unit 2.

For example, it may be similar to the material receiving and spreading imits disclosed in the patents to Mosel, Nos. 2,054,436 and 2,054,437,

which issued September 15, 1936. Othertypes of feeding units may also be employed. For example, the hopper 3 of the unit I may be provided with a movable bottom 3a in the form of an endless conveyer which will serve to feed the material rearwardly and deposit it in front of the unit 2. The hopper 3 preferably receives the mixed material froma dump truck or other suitable source. I r

The unit I is carried by a pair of relatively long caterpillar traction units 4. These units 4 will pass over small irregularities of the sub-grade or old roadsurface without any appreciable vertical movement of the unit I.

The unit 2 consists of a transversely extending screed member 5 and a U-shaped supporting frame 5 from which it is suspended. This U-shaped supporting frame 6 consists of forwardly extending draw plates I which extend along the opposite sides of the unit I and which have their; forward ends pivotally connected thereto, as at 8. The pivot points 8 are located substantially midway between the front and rear ends of the unit I so that vertical movement of the unit I will have a minimum efiect on the unit 2. The rear ends of the plates 1 are connected to the lower portions of upstanding screed supports and guides 9. These screed sup ports and guides 9 are rigidly joined together by means of a transversely extending beam I 0. The screed 5 is suspended from the supports 9 in a manner to be explained later.

The entire weight of the unit 2 is carried by a pair of longitudinally extending runner members II. Each of these runner members II is disposed directly inside the plate I. These runner members are comparatively long and each of them is pivotally connected, as at I2, to the plate I. The pivot point I2 is located substantially midway between the front and rear ends of the plate I and substantially midway between the 'front and rear ends of the runner II. A pivot I2a carried at the front end of runner II operates in an arcuate slot I 2b formed in the plate 1. Each plate I carries a vertically disposed plate I3.which is mounted thereon for vertical adjustment by means of the pin and slots I4.

' The plates -I3 are provided at the ends of the screed unit 5 and are adapted to limit spreadmember and to form straight edges on the layer of material produced by the machine.

The screed unit 5 consists of a beam I5. From the beam I5, there is suspended a screed. memberv or finishing member I6. The member I6 may be suspended from the member I5 by means of the adjustable bolts I1. However, itis to be understood that we may employ any suitable type of screed unit. For example, we may use a screed unit of the type disclosed in the co-pending application of Millikin and Apel, executed on the 29th day of July i940. A rotatable screw spreading member 3bor spreading member of any other suitable type, may be disposed in front of the screed unit to spread the material laterally before it is acted on by the screed. This screw maybe carried by the unit 2 or the unit I and may be of a type disclosed in the said Mosel patents.

In order to suspend the screed unit 5 from the supports 9, we provide the following structure. This structure comprises a piston rod I9 which has its lower end secured to the end of the beam I5. The upper end of this rod I3 carries a piston 20 which is disposed in a vertically disposed hydraulic cylinder 2I. The cylinder 2i is carried on the upper end of the support 9 between the spaced columns 311 and 9b thereof. The beam I5 of the screed unit has its ends disposed between the columns 9a and 9b of the supports 9 and these columns function as guides for guiding vertical movement of the screed unit. Each of the hydraulic cylinders 2| has a line 22 leading from the upper end thereof and a line 23 leading from the lower end thereof. The

lines

22 and 23 are'connected to an automatic control valve 24. The details of this valve 24 will be described later.

} Two valves 24 are provided and they are located adjacent the ends of the screed unit 5. Each of these valves has its cylindrical housing immovably supported by a bracket 25 on the beam I5 of the screed unit. Each of the valves 24 has a rod or stem 26 projecting from the lower end thereof. This stem is vertically movable relative to the housing of the valve. It has its lower end hingedly connected at 21 to the upper end of a sleeve 23. The lower end of the sleeve isinteriorly threaded and receives the threaded pin 29. This pin 29 has its lower end pivotally connected, as at 30, toa bracket 3 I. The bracket 3I isrigidly connected to the vertical portion 32 of a leveling arm 33.

is pivotally connected to the side of the unit I. 4

Suitable guides 35 may be provided on the unit I for preventing lateral movement of the arms 33 but for permitting vertical movement thereof. The points 34 are substantially in alignment with the points 8 where the units I and 2 are pivotally connected together. Furthermore, the points '34 are almost at the same level as the points 3 so that they will be close to the line of pull between the units I and 2.

The lower ends of the portions 32 of the arms 33 are turned rearwardly, as at 36; The extreme rear ends of these arms are pivotally connected as at 3'I, to the upper ends of the links 38. The links 38 carry collars 33 on their lower ends which are rotatively carried by a transversely extending shaft 40. This shaft 40 has collars 4I keyed thereon which are provided with depending portions 42 that are pivoted, as at 43, to brackets 44 This arm extends for- '55 wardly over the screed unit 5 and then downhave their forward ends pivotally connected to.

the screed unit, as at 45. The rear ends of these draw bars are integrally secured to the collars 39. A transverse shaft 48 has its ends connected to the bars 41 and is disposed parallel .to the shaft 45. The

shafts

45 and 49 serve to keep the draw bars '41 parallel with each other. It turnbuckle 55 is connected to each end of the shaft 49 and its lower end is pivotally connected to the pan 45, as at By'adiusting these turnbuckles, the pans 45 may be adjusted to the proper position relative to bars 41.

It is desirable to adjust the stems 25 of the valves 24 in and out of the valve housings in order to vary theelevation of the points 85.. For this purpose, each ofthe valves 24 has a shaft 52 rotatably carried thereby. The lower end of this shaft 52 has a flanged gear 59' keyed thereon which meshes with a gear 54 keyed on the lower end of the stem 25. By rotating shaft 52, the

' sleeve 28 is rotated and causes the pin 29 to thread into or out, of the sleeve. Consequently, this raises or lowers the point 95 and, changes the distance between the valve 24and pan 45.

' Thus, by rotating the shafts 52, the elevation of y the pans 45 relative to the screed member l8 can be adjusted.

The structure of each of the valves 24 is illustrated best in Figures 6 and '1. Each valve comprises a cylindrical housing having the stem 25 projecting from the lower end thereof, as previ ously explained. The valve stem 25 is slidably mounted in a packing gland 55 threaded into the lower end of the valve housing. This stem 25 carries axially spaced enlargements or collars 55, 51-, 58 and 59 which fit tightly within the valve housing but which do notinterfere with vertical movement of the stem within the housing. Thus,

a middle annular chamber 55, an upper annular chamber 5| and a lower annular chamber 52 are produced around the valve stem. The valve housing is provided with an inlet port 53, which is always in communication with the chamber 80. The wall of the valve housing has a vertical passageway 54 formed therein which is provided with an upper opening 85 that always communicates withthe chamber 8| and a lower opening 58 that always communicates with the chamber 52. The passage 54 is provided with an outlet opening 81 formed in the wall of the valve housing. The wall of the valve housing is also pro-v vided with an upper port 88' and a lower port 59 which are normally closed by the portions 58 and 51 of the valve stem.

As indicated best in Figure 3, the inlet ports 53 of the two valves 24 are connected together by a line 10. The outlet ports'of the two valves are connected together by a line 1|. The conduits 23 are connected to the ports 58 of thetwo valves and the conduits 22 are connected to the ports 59 of the two valves. The line is connected by means of a high pressure line 12 to the discharge side of a hydraulic pump 19. The inlet side of the pump is connected by a line 14 to an oil tank 15. A line 15 connects the line 12 to the line 1|. This line 15 has an adjustable automatic relief valve 11 incorporated therein. A connection is provided between the line 15 and mally seats. The ball 88 is held on its seat by a spring 81 which may be adjusted to vary the the port 85 required to unseat the line 12 and a variable pressure control valve 18 is incorporated therein. A low pressure line 18 is connected to the line 15 and leads to the bottom of the tank 15.

Each of the lines 2: has a check valve to mcorporated therein. The structure of this check valve is illustrated in Figure 8. This check valve spring may be varied to vary-the pressureof incoming liquid necessary to unseat the ball 82. A'by-pass passageway 84 extends around the ball check valve 82. This passageway includes a port 85 upon the upper end of which a ball 85 norforce of the upward pressure of liquid through the ball 85 from its seat. The port 85 communicates with outlet passage 88. This valve 88 will function in -a manner to be described later. The inlet 8| is connected to opening 85 in valve 24 by a portion of line 23.

In using our machine, the pans are adapted normally to be disposed at the same level as the finishing member l8. In starting to laythe material, the pans 45 may be adiusted to the proper height by means of the shafts 52. For example, if it is desired to lay six inches of material, the pans 45 will be adjusted to a height six inches above the lower edges of the runners The pans will preferably be disposed on the surface of a previously laid layer which the new layer. roduced by our machine, is adapted to join, or planks or other suitable temporary supports of the proper thickness behind the machine. The screed unit 5 will then be raised automatically by the hydraulic means until the member I5 is at the same level as the pans'45. From an inspection of Figure 3, and Figures 6, 7 and 8, and

from the following description, the manner in which this is accomplished will be clear. Since the member I5 is initially lower than the pans 45, the stems 28' of the valves 24 will be forced upwardly, because the leveling arms 32 will have I been swung upwardly about pivots 34, exposing the openings. and 59. The oil pump 13 will force oil under pressure through line 12, line 18,

through inlets 58 of the valves 24, through chambers 80, through the upper openings 58, through check valves 85 and conduits 28 into the lower ends of the screed hoisting cylinders 2|. This will move the pistons 25 upwardly. Part of the oil in the upper ends of. the cylinders 2| will be forced into the lines 22, through openings 59.

. through chambers 52, through openings 55 and passageways 54, through the line 1| and into the line 18, into the line 19 and then into the tank I 15. The pump 18 will maintain, in the system,

the pressure for which the relief valve 11 is set. When the screed unit is lifted to a height such that the member I5 is at the same level as the pans 45, the valve stem 25' will have been returned to its neutral position indicated in Figure 'I because the levelof the pans 45 and the member |8 will coincide at this time. This is accomplished because when the screed unit 5 is lifted, the housings of the valves 24 are moved upwardly relative to the stems 28. when the member I5 is at the same level as the pans 45;" the portions 51 and 58 of the stems will be in covering relationship to the openings 58 and 89. If the pans 45 are initially set at a lower level than the fln- .ishing member I8, the hydraulic system will func-q tion in a similar manner to lower the screed unit until the pans 45 and the member I3 are at the same level.

The valves 80 are provided to prevent settling or gradual lowering of the screed unit 5. When the valve 24 is in proper condition to allow the oil to enter inlet 3| of valve 80, associated therewith, the ball 82 willbe unseated. However, if

the weight of the screed unit 5 starts to force the oil back through line 23 past the ball 32, the ball will be seated. Thus, settling of the screed will be precluded. However, the by-pass 84 is provided to permit the oil to flow from line 23 back past the ball valve =82 when desired. This is desirable when the valves 24 are in such position that oil will be supplied to the upper ends of cylinders 2I to force the pistons downwardly. Then the pressure of the oil will be suflicient to unseat ball 86 and allow the oil to pass through by-pass 84. The spring 3'! is set so that the weight of the screed alone is not suflicient to unseat the ball 86. To unseat the ball 86, there must also be positive pressure exerted on the upper ends of the pistons 20 by oil entering the upper ends of cylinders 2| which will produce an increased pressure in lines 23.

. After the machine is adjusted and the laying of the material begins, it will function in the manner illustrated in Figures 4 and 5. The pans 45 and the member I6 will be at the same level. The 'pans 45 will be riding on the surface of the layer of material produced by the machine. As the machine moves along, the material is fed from the unit I and is deposited in front of the screed unit 5. Member I6 of the screed unit will level off this material to a predetermined height. As indicated in Figure 4, because of the long traction members 4, small irregularities in lower the screed member I automatically. Movement of the unit I relative. to the unit 2 in the manner indicated will move the housings of the valves 24 upwardly relative to the stems 26 of the valves. This will uncover the

openings

63 and 39, in the manner previously described, and will allow the'oil to be displaced from the lower ends of the cylinders 2| to the upper ends thereof so as to lower the screed unit. When the line AB and the lineCD are again in parallelrelationship, the valves 24 will cease to ,function and the screed unit will, at this time, be in its original position and will be held in such position until the lines AB and CD areagain out of parallel relationship. This leveling out process will be a gradual process, as the machine moves forward, and, therefore, will eliminate all sharp bumps and will'produce a smooth riding surface. The extent of movement of the screed unit relative to the extent of the vertical movement of the unit I is governed by the ratio of I the distance from the points 34 to the points 31 the surface being covered will be bridged thereby and will not cause any appreciable vertical move- I ment of the unit I. The thickness of the. layer of the material is obtained as previously indicated by shortening or lengthening the distance between the valves 24 and the pans 45, which may be accomplished by rotating the shafts 52.

The screed member I6 will operate in the same plane as-long as the line CD remains parallel with the line AB passing through the pivot point 34 where the leveling arm 33 is pivoted to the unit I. lower surfaces of the pans 45 and the finishing member I6'of the screed. Line AB is the average contour of the base. and CD are parallel, the valves 24 will not function and the hydraulic system will merely serve to keep the screed unit at the predetermined level. As the machine moves along, the runners II will also bridge small irregularities so that they will not produce vertical movement of the unit 2. The runners serve to support all of the weight of the screed unit which is not supported by the unit I. Thus the weight is kept off of the screed unit 5 so that it will not compress the layer of material to an undesirable extent.

As indicated in Figure 5, if the lines AB and CD become non-parallel, due: to the unit I, for

The line CD corresponds to the As long as the lines AB example, passing up over a sharp rise in the surface being covered, the valves 24 will function to change the level of the screed unit. When the unit I tilts rearwardly and downwardly in the manner indicated in Figure 5, there is a tendency for the member I6 to be lifted. This would produce a sharp bump in the finished surface unless some means were provided to overcome it. The valves 24 will, however, act to withthe distance from the points 30 to the points 31. We have found that a suitable ratio is 12 to 1 although other ratios may also be used.

If the runners I I ride over sharp irregularities and cause vertical movement of the unit 2, the valves 24 will function in a manner similar to that described in the preceding paragraph to change the level of the screed member. For example, if the member I8 is lifted, the housings of the valves 24 will be lifted relative to the stems 26. This will automatically lower the screed unit in the manner previously described. When the lines AB and CD are again in parallel relationship, the valves 24 will cease to function. This vertical movement of the screed'unit, caused by the unit I moving vertically or the runners II moving vertically, will be compensated for andthe sharp irregularities of the surface over which they operate will not be present in the finished surface. but will be averaged out.

In Figure 9, we have illustrated how our magrade line set along the edge of the surface being covered. As indicated, we may provide a form or line E which is supported on stakes F and is set at a predetermined grade line. One

of the pans 45 is eliminated, the shaft 40a is extended and carries a roller 45a, or other suitable member, which will roll on the form E. The other pan will operate on the finished layer as before. The machine will functionexactly the same as before with the exception that a new grade line, corresponding to that of line E, will be produced on the finished layer at the side adjacent the form E regardless of the grade of. the surface over which the machine passes. In some instances, it may be desirable to provide rollers 45a at both sides which cooperate with forms E. In; such instances, a complete new grade corresponding to that of the forms E may be established. The unit I will pass over the irregularities of the sub-grade or old road surface, but the rollers 45a operating on the forms E will cause automatic adjustment of the screed to average out these irregularities.

In Figure 10, we show a roller 45a operating on a concrete curb G. The machine will lay the material next to the curb to a level corresponding to that of the curb, if desired. Thus, the machine may be used for joining effectively one layer of material to another layer disposed along the edge thereof.

It will be apparent from the above description tical ,movement of the supporting frame as the that we have provided apparatus for surfacing roads which is of such a nature that the irregularities of the surface being covered by the material will be averaged out in the finished surface so that the finished surface will be free of sharp irregularities or bumps. Our apparatus is of sucha nature that it may be used in resurfacing an old road to produce a surface having the same general grade as the old surface with the'sharp irregularities thereof eliminated or it may cooperate with a new grade line, set along the edge of the road, to produce'a surface having an entirely different grade from the surface being covered. Furthemore, it will be apparent that the apparatusis of such a nature that the finishing member resting on the layer of material will not support any substantial weight of the machine. Consequently, the material will not be compressed to such an extent that it will be sealed and will retard curing or setting thereof. Our apparatus is very efiective but is relatively simple.

Although we specify that the hydraulic system automatically controls the level of the screed machine moves along.

4. A machine for surfacing a road comprising a leveling member adapted to act upon material applied to the surface to be covered, means for supporting said member on the machine for vertical movement, said means comprising a hydraulic cylinder and piston'unit, means for supporting said machine for movement along the surface to be covered, said means operating on the surface to be covered, and means'for automatically changing the vertical position of said a leveling member on the machine in accordance unit, it is to be understood that it can be employed for controlling the level of any leveling or similar member provided on a road building machine.

Various other advantages will be apparent from the preceding description, the drawings and the following claims.

Having thus described our claim is:

l. A machine for surfacing a road or the like comprising a unit embodying a screed member, a frame for supporting said screed member, a hydraulic cylinder and piston unit for suspending said screed member on said frame for vertical movement, means for supporting said frame for movement along the surface to be covered, automatic means for actuating said cylinder and pise ton unit to change the elevation of said screed" invention, what we on said frame to compensate for vertical movement of said frame as the machine moves along the surface to be covered, said means comprising a control member adapted to operate on the finished surface produced by the screed, said control member being connected to a control valve which serves to actuate said cylinder and piston unit whenever the frame moves vertically relative to said control member.

2. A machine according to claim 1 wherein the means for supporting said frame embodies longitudinally extending elongated runner members which slide along the surface to be covered and which are pivotally connected to said frame.

3. A machine for surfacing a road or the like comprising a unit embodying a screed member, a frame for supporting said screed member, a hydraulic cylinder and piston unit for suspending said screed member on said frame for vertical movement, means for supporting said frame for movement along the surface to be covered, automatic means for actuating said cylinder and piston unit to change the elevation of said screed on said frame to compensate for vertical movement of said frame as the machine moves along the surface to be covered, said means comprising a control member normally disposed at the same control member whenever the screed is moved vertically relative to the control member by ververtical movement relative thereto and adapted with vertical movement of the machine as it moves along over the surface to be covered, said means comprising a control member supported on the machine forvvertical movement relative to the leveling member and adapted to ride on a surface having a predetermined grade line, said control member being connected to a control valve which serves to actuate said cylinder and piston unit to move said leveling member vertically on the machine in an opposite direction whenever the leveling member moves vertically relative to the control member in one direction during movement of the machine along the surface to be covered.

5. A machine for surfacing a road comprising a material feeding unit, means for supporting said unit for movement along the surface to be covered, said means operating on the surface to be covered, a material-leveling unit embodying a leveling member disposed behind the first unit and adapted tolevel oif material supplied by said unit, means for supporting said secondunit for movement along the surface to be covered, said means operating on the surface to be covered, means for connecting said units together to permit relative vertical movement thereof, hydraulic cylinder and piston units for supporting said leveling member on the second unit, and means for automatically changing the vertical position of said leveling member as the machine moves vertically in passing along over the surface to be covered, said means comprising a control member supported on the'machine for vertical movement relative to the leveling member and adapted to ride on a surface having a predetermined grade line, said control'member being disposed at a point behind said leveling member and being connected to the rear end of a lever arm,

said lever arm having its forward end 'pivotally connected to said first-named unit, a control valve for actuating said cylinder and piston units, said control valve being connected to said lever arm at a point intermediate the points of connection of said arm to said control member and t to said'first-named unit.

,16. A machine for surfacing a road comprising a leveling member adapted to act upon material applied to the surface to be covered, means for supporting said member on the machine for vertical movement, said means comprising hydraulic cylinder arid piston unit forsuspending said leveling member on the machine, means for supporting said machine for movement along the surface to be covered, said means operating on the surface to be covered, and means for auto- 6 Y to operate upon the surface produced by said leveling member, said control member being connected to a control valve which serves to actuate said cylinder and piston units to move said leveling member vertically on the machine in an opposite direction whenever the leveling member moves vertically relative to the control member in one direction during movement of the machine;

along the surface to be covered.. g

7. A machine for surfacing a road comprising a material feeding unit, means for supporting said unit for movement along the surface to 'be covered, "said means operating on the surface to be covered, a material-leveling unit embodying a' leveling member disposed behind the first unit and adapted to level off material supplied by said unit, means for supporting said second unit for movement along the surface to be covered, said means'operating on the surfaceto be covered, means for connecting said units together to permit relative movement thereof, hydraulic cylinder and piston units for suspending'said leveling member from the second unit, and means for automatically changing the vertical position of said leveling member as the machine moves vertically in passing along over the surface to be covered, said means comprising a control member supported on said second-named unit behind said leveling member for vertical movement relative thereto and adapted to operate upon the surface produced by said leveling member, said control member being connected to the rear end of a lever 'arm, said lever arm having its forward end pivotally connected to said flrstnamed unit, a control valve for actuating said cylinder and piston units, said control valve being connected to saidlever arm at a point intermediate the points of connection of said arm to said control member and to said first-named unit and bein actuated by movement thereof. I

' 8. A machine for surfacing a road comprising a leveling member adapted to act upon material applied to the surface to be covered, means for supporting said member on the machine for vertical movement, said means comprising'hydraulic cylinder and piston units, means for supporting said machine for movement along the surface to be covered, said means operating on the surface to be covered, and means for automatically changing the vertical position of said leveling member on the machine in accordance with vertical movement of the machine as it moves along over the surface to be covered, said means comprising a control member supported on the machine for vertical movement relative to the leveling member at a point behind said leveling member and adapted to ride on a surface having a predetermined grade line, said controlmember being carried by therear end of a lever am, said lever arm having its forward end pivotally connected to the machine at a point in front of said leveling member, a control valve for actuating said cylinder and piston units, said surface to be covered, said means operating on the surface to be covered, and means for automatically changing the vertical position of said leveling member on the machine in accordance I with vertical movement of the machine as it moves along over the surface to be covered, said means comprising a'c'ontrol member supported on the machine behind said leveling member for vertical movement relative thereto and adapted to operate upon the surface produced by said leveling member, said control member being carried by the rear endof a lever arm, said lever arm having its forward. end pivotally connected to the machine at a point in front of said leveling member, a valve for controlling said cylinder and piston unit, said control valve being connected to said lever arm at a point intermediate the point of connection of said arm to said control member and tosaid machine.

10. A machine for surfacing a road comprising a unit supported for movement along the surface to be covered by means operating on said surface,

I a a material leveling unit embodying ,a leveling member adapted to act upon material applied to the surface to be covered, means for supporting said leveling member on the second-named unit and adapted to be actuated to move said leveling member to various vertical positions on said second-named unit, means for supporting said sec-. ond-named unit for movement along the surface to be covered, said means operating along the surface to be covered, means for connecting said units together to permit relative vertical movement thereof, and means for actuating said levelin: member supporting means to automatically change the vertical position of said leveling member as the machine moves vertically in passing along over the surfacelto be covered, said means comprising a control member supported on the machine for vertical movement relative to the leveling member at a point behind ,said leveling member and adapted to ride on a surface having a predetermined grade-line. said control member A being carried by the rear end of a lever arm, said lever arm having its forward end pivotally connected to said first-named unit, said lever arm being operatively'connected'to said leveling mem-.

ber supporting means at a point intermediate the ends of said arm so as to actuate'said leveling member supporting means to move said leveling member vertically in an opposite direction whenever the leveling member moves vertically relative to the control member in one direction during movement of the machine along the surface to be covered.

11. A machine for surfacingta road comprising surface to be covered, said means operating along the surface 'to be covered, means for connecting said units together to permit relative vertical movement thereof, and means for actuating said leveling member supporting means to automatically change the vertical positionof said leveling member as the machine moves vertically in passing along over the surface to be covered,

said means comprising a control member supported on the machine for vertical movement relative to the leveling member at a point behind said leveling member and adapted to ride on the surface produced by said leveling member, said lever arm having its forward end pivotally connected to said first-named unit, said lever arm being operatively connected to said leveling member supporting means at a point intermediate the ends of said arm so as to actuate said leveling member supporting means to move said leveling member vertically in an opposite direction whenchine and adapted to be actuated to move said leveling member to various vertical positions on the machine, and means for actuating said levela ing member supporting means to automatically ever the leveling member moves vertically relative to the control member in one direction during movement of the machine along the surface to be covered.

12. A machine for surfacing a road comprising supporting means for supporting the machine for movement along the surface to be covered, a material leveling member adapted to act upon material applied to the surface to be covered, means for supporting said leveling member on the machine and adapted to be actuated to move said leveling member to various vertical positions on the machine, and means for actuating said leveling member supporting means to automatically change the vertical position of said leveling member as the machine moves vertically in p along over the surface to be covered, said ineans comprising a control member supported on themachine for vertical movement relative to the leveling member at a point behind'said leveling member and adapted to ride on a surface having a predetermined grade line, said control member being carried by the rear end of a lever arm, said lever arm having its forward end pivotally connected to the machine, said lever arm being operatively connected to said leveling member supporting means at a point intermediate the ends of said arm so as to actuate said leveling member supporting means to move said levelin member vertically in an opposite direction whenever the leveling member moves vertically relative to the control member in one'direction during movement of the machine along the surface to be covered.

13. A machine for surfacing a road comprising supporting means for supporting the machine for movement along the surface to be covered, a ma terial leveling member adapted to act upon material applied to the surface to be covered, means for supporting said leveling member on the machange the vertical position of said leveling member as the machine moves vertically in'passing along over the surface to be covered, said means comprising a control member supported on the machine for vertical movement relative to the leveling member at -a point behind said leveling member and adapted to ride on the surface produced by said leveling member, said control meanher being carried by the rear end of a lever am, said lever arm having its forward end pivotally connected to the machine, said lever arm being operatively connected to said leveling member supporting means at a point intermediate the ends of'said arm so as to actuate said levelin member supporting means to move said leveling member vertically in an opposite direction whenever the leveling member moves vertically relative to the control member in one direction duringmovement of the machine along the surface to be covered.

a leve member adapted to act upon material applied to the surface to be covered, means for supporting said leveling member on the machine and adapted to be actuated to move said leveling member to various vertical positions on the ma.- chine, means for supporting said machine for movement along the surface to be covered, and means for actuating said leveling member supporting means to automatically change the vertical position of said leveling member on the machine as the machine moves vertically in passing along over the surface to be covered, said means comprising a control member supported on the machine for vertical movement relative to the leveling member and adapted to ride on a surface having a predetermined grade line, said control member being operatively connected to said leveling member supporting means so as to actuate said leveling member supporting means to move said leveling member vertically in an opposite direction whenever the leveling member moves vertically relative to the control member in one direction during movement of the machine along the surface to be covered.

ARNOLD S. HENRY M. PIC.

: chine for surfacing a road comprising