US3015257A - Hydraulically operated pavement finishing machine - Google Patents

Description

Jan. 2, 1962 .1. H. APEL ETAL HYDRAULICALLY OPERATED PAVEMENT FINISHING MACHINE Filed July 24, 1957 8 Sheets-Sheet 1 INVENTORS JOHN H. APEL ROBERT J. BEESON BY CORBETT, MAHONEY, MILLER & RAMBO l ML Jan. 2, 1962 J. H. APEL ETAL HYDRAULICALLY OPERATED PAVEMENT FINISHING MACHINE Filed July 24, 1957 8 Sheets-Sheet 2 INVENTORS JOHN H. APEL ROBERT J. BEESON CORBETT, MAHONEY, MILLER A RAMBO Jan. 2, 1962 J. H. APEL ETAL 3,015,257

HYDRAULICALLY OPERATED PAVEMENT FINISHING MACHINE Filed July 24, 1957 8 Sheets-Sheet 3 INVENTORS JOHN H. APEL ROBERT J. BEESON CORBETT, MAHONEY,MILL.ER 8 RAMBO Jan. 2, 1962 J. H. APEL ETAL 3,015,257

HYDRAULICALLY OPERATED PAVEMENT FINISHING MACHINE Filed July 24, 1957 8 Sheets-Sheet 4 "ML FR 33 FHA INVENTORS JOHN H. APEL BY ROBERT J. BEESON QORBETT, MAHONEY, MILLER 8. RAMBO BY I Jan. 2, 1962 J. H. APEL ETAL HYDRAULICALLY OPERATED PAVEMENT FINISHING MACHINE Filed July 24, 1957 8 Sheets-Sheet 5 FIG. IO

INVENTORS JOHN H. APEL ROBERT J. BEESON Y coR zrr, MAHONEY,MILLER & RAMBO Jan. 2, 1962 J. H. APEL ETAL 3,015,257

HYDRAULICALLY OPERATED PAVEMENT FINISHING MACHINE Filed July 24, 1957 8 Sheets-Sheet 6 FIG. ll

INVENTORS JOHN H. APEL. ROBERT J. BEESON BY CORBETT, MAHONEY, MILLER 8- RAMBO Jan. 2, 1962 J. H. APEL ETAL 3,015,257

HYDRAULICALLY OPERATED PAVEMENT FINISHING MACHINE Filed July 24, 1957 8 Sheets-Sheet 7 FIG. l5

INVENTORS JOHN H. APEL BY ROBERT J. BEESON CORBETT, MAHONEY, MILLER & RAMBO Jan. 2, 1962 J. H. APEL ETAL 3,015,257

HYDRAULICALLY OPERATED PAVEMENT FINISHING MACHINE Filed July 24, 1957 8 Sheets-Sheet 8 INVENTORS JOHN H. APEL ROBERT J. BEESON BY CORBETT, MAHONEY, MILLER 8\ RAMBO United States Patent 0 3,015,257 HYDRAULICALLY OPERATED PAVEMENT FINISHING hIACHINE John H. Apel and Robert J. Beeson, Columbus, Ohio, as-

signors to The Jaeger Machine Company, Columbus, Ohio, a corporation of Ohio Filed July 24, 1957, Ser. No. 673,943 Claims. (CI. 94-45) Our invention relates to a hydraulically operated pavement finishing machine. The machine of this invention will be described as a machine for finishing concrete pavements, but it should be understood that it is not limited thereto and can be used for finishing pavements of other materials.

Accordingly to this invention, we provide a finishing machine which comprises a frame carried by driven wheels for movement along the pavement to be finished. For example, if the pavement is formed of concrete laid between forms, the frame will be carried by tramming or propelling wheels which operate on such forms. The wheels are driven by independently controllable hydraulic motors at each side of the frame so that steering is possible by driving the wheels at one side at a higher speed from those at the other side. The frame is composed of telescoping transverse tubular sections so that the frame can be adjusted for pavements of different widths. This adjustment is made by means of hydraulic units associated with these sections. At its front end, the frame carries a forward screed. This screed can be elevated by mechanism which is controlled by a hydraulic unit associated therewith. This screed is reciprocated 'by a hydraulic screed-driving motor connected thereto. Rearwardly of the forward screed on the frame there is carried another screed, which is preferably a diagonal screed and which is reciprocated by the hydraulic screed-driving motor which is also connected thereto. This screed is also preferably elevated under control of a hydraulic unit and, in addition, the angular position of this screed preferably is changed by hydraulic units associated therewith. The angular adjustment of the rear screed can be made regardless of the telescoped position of the frame sections. For transportation, the frame is provided with a pair of transporting wheels which are adapted to roll transversely of the frame at right angles to the direction in which the trarnming wheels operate. These wheels are normally disposed in raised inoperative position on the frame but hydraulic units are associated therewith for lowering them into supporting position. For cooperating with these transporting wheels and their adjusting mechanism, a hydraulic jack is attached to the frame and is so associated therewith that by proper manipulation of the jack and the transporting wheels, a three-point support of the machine is possible independently of the side forms so that the machine may be maneuvered ofi the side forms for transportation to a new location. Associated with the jack is a tongue structure by means of which the machine may be pulled to another location and the jack is adjustable on'the frame to a raised inoperative position which it normally occupies so as not to interfere with movement of the machine on the transporting wheels. Thus, all units of the machine are hydraulically operated and the machine can be controlled in the finishing action and can also be manipulated for transportation by a single operator with a minimum of effort.

The accompanying drawings illustrate a concrete finishing machine embodying the principles of our invention but it is to be understood that details thereof may vary without departing from basic principles.

In these drawings:

FIGURE 1 is a side elevational view of a concrete finishing machine in which our invention is embodied.

FIGURE 2 is a plan view of the machine.

FIGURE 3 is a diagrammatic plan view illustrating the width adjusting structural arrangement of the machine.

FIGURE 4 is a front elevational view of the structural arrangement of FIGURE 3.

FIGURE 5 is a transverse vertical sectional view taken along line 55 of FIGURE 4 showing the telescoping tube sections forming part of the width adjusting structural arrangement.

FIGURE 6 is a vertical sectional view taken axially through the tube sections along line 66 of FIGURE 5.

FIGURE 7 is a plan view illustrating the structural arrangement for supporting and positioning the diagonal screed of the machine.

FIGURE 7a is a sectional view showing the pivotal connection of the screed support tube.

FIGURE 8 is a transverse vertical sectional view taken substantially along line 38 of FIGURE 7.

FIGURE 9 is a detail in side elevation showing one of the adjustable transporting wheels and the arrangement for operating it.

FIGURE 10 is a transverse sectional view taken along line 10-10 of FIGURE 2 showing the structural arrangement for supporting and elevating the front screed of the machine.

FIGURE 11 is a diagrammatic plan view of the tramming wheels driving arrangement at one side of the machine.

FIGURE 12 is a side view of the machine showing one of the elevating jacks and the tongue used for transporting the machine.

FIGURE 13 is a plan view of the hydraulic motor and drive mechanism for reciprocating the front and diagonal screeds.

FIGURE 14 is a plan view showing the two hydraulic pumps ofthe machine arranged in tandem and the motor for driving them.

FIGURE 15 is a top view showing the connection between one end of the rear diagonal screed and the associated adjustable side frame section.

FIGURE 16 is a side view of the structure of FIGURE 15.

FIGURE 17 is a schematic view of the hydraulic system of the machine.

With reference to the drawings, in FIGURES 1 and 2, we have shown the general structure of our machine. The machine consists basically of the frame 20 which is carried by the tramming Wheels 21; the front screed 22, supported at the forward end of the frame; the rear or diagonally adjustable screed 23, supported intermediate the front and rear of the frame; the adjustable transporting wheel units 24, disposed at the forward and rearward ends of the frame intermediate the sides thereof; and the lifting jack unit 25 disposed at one side of the frame and associated with the pulling'tongue unit 26 at that side.

The frame 20 (FIGURE 2) is fabricated into substantially rectangular form and extends transversely of the surface to be paved being supported at its four corners by the trarnming wheels 21. If this machine is being used to finish concrete, the wheels 21 will operate on side forms as indicated in FIGURES 1 and 12. The frame 20 includes a fixed central section 30 which supports an operators platform 31 and adjustable side sections 32 each of which supports a pair of the wheels 21.

At each of its forward and rearward ends (FIGURES 3 and 4) the section 30 is provided with a pair of vertically spaced transversely extending tube supports 33 which are joined rigidly together by the vertically disposed transversely extending plate 34. The plates 34 are rigidly connected together by the forwardly and rearwardly extending beams 35 which support the platform 31. The

side frame sections '32 each includes the forwardly and rearwardly extending beam 36, which carry the wheels 21, and the inwardly extending tubular arms 37 which are rigidly connectedto the members 36 at right angles thereto and are arranged in vertically spaced pairs for cooperation with the tubes 33. These members 37 telescope within the adjacent ends of the tubes 33, as shown in FIGURES and 6. Thus, the side frame sections 32 can be adjusted in and out relative to the central fixed frame section 30.

We provide a hydraulic arrangement for adjusting either of the side sections 32 independently of the other. This hydraulic arrangement is shown best in FIGURES 1, 3 and 4, but is also indicated in FIGURES 2 and 17. v The frame-adjusting hydraulic arrangement comprises the four ram units (FIGURE 3) which are arranged in pairs of rams 40 and 41 at each side of the frame, the two units of each pair being connected between the adjustable side frame section 32 and the fixed frame section 30. Each ram unit comprises a cylinder 42 (FIGURE 4) which is anchored at 43 at its inner end to a bracket depending from the fixed frame section 30, and which has an outwardly extending piston rod 44 that is anchored at 44a to the side beam member or housing 36.

As indicated in FIGURES l and 11, each pair of tramming wheels at each side of the machine is driven by means of a hydraulic motor. These motors are supported on the beams 36 and are designated by the numerals 45 and 46 in FIGURE 2 and may be of the rotary gear type. As will be explained later, these motors are controlled independently to aid in keeping the machine in proper position on the side forms. By selectively driving the motors at different speeds, steering in the proper directions can be obtained. The drive for only one pair of the tramming wheels is shown in FIGURE 11 but both drives are identical; The motor 45 drives a gear reduction unit 47 through a chain and sprocket drive 48. This gear unit 47 drives a rearwardly extending chain and sprocket drive 49 and a forwardly extending chain and sprocket drive 50. The rearwardly extending chain and sprocket drive 49 drives a downwardly extending chain and sprocket drive '51 which directly drives the axle 52 that carries the forward wheel 21. The forwardly extending chain and sprocket drive 50 drives a downwardly extending chain and sprocket drive 53 which directly drives the rear axle 54 that carries the rear wheel 21.

The front screed structure 22 is illustrated best in FIG- URES 1, 2, and 10. The screed itself is of usual nonextensible rigid construction but is associated with the frame 20 of the machine, is reciprocated, and is elevated, by a novel structural arrangement. In actual use, as shown in FIGURE 10, the screed 22 rests on the side forms. The forward and outer corner of each of the movable side sections 32 are provided with downwardly and forwardly extending thrust arms 60. The forward end of each of these arms carries a vertically disposed thrust roller 61 and the pair of these rollers at each side of the machine is positioned within a laterally extending guide 62 attached to the rear side of the screed 22 adjacent the end thereof which keeps the screed in association with the rollers. Thus, the screed is free to reciprocate transversely of the machine at the forward end of the frame but the thrust rollers 61 engage the rear side of the screed and provide the proper thrust thereon as the screed advances into the material, the rollers preventing the development of excessive friction. Furthermore, these thrust rollers are always adjacent the side forms, since they are always positioned at the sides of the ma chine, regardless of the position of the extended side frame sections 32. The guides 62 are elongated and will permit the proper lateral extension of either of the frame sections 32 without interfering with the transverse reciprocation of the screed.

The screed is reciprocated by means of a crank and pitman arrangement 63 shown in FIGURES 2 and 13,

and, as indicated above, the screed is so associated with the frame that reciprocation thereof is not interfered with regardless of the adjustment of the side frame sections 32. The crank and pitman structure is driven by a shaft 64 which is supported by the central section 30 of the frame and extends forwardly therefrom, as shown in FIGURES 2 and 13. This shaft 64 is directly driven by a laterally extending chain and sprocket drive 65 which is driven by a transversely extending chain and sprocket drive 66 from a rotary type hydraulic motor 67 supported on the platform 31.

For elevating the screed 22, we provide the arrangement shown best in FIGURES 1 and 10. This elevating means is carried by the forwardly and upwardly extending supporting arms 76, one of which is carried adjacent each forward and outer corner of the fixed central frame section 39. These arms 70 carry a rockable shaft 71 extending transversely of the machine. Keyed to this shaft 71 are the forwardly extending crank arms 72 which carry the adjustable depending links 73 that are pivoted thereto. The lower ends of these links are provided with clevis fittings 74 which carry the cradle rollers 75. These rollers 75 engage screed support rods 76 which are rigidly carried by the screed 22 and extend longitudinally thereof. Thus, the connection between the elevating mechanism and the screed permits longitudinal reciprocation of the creed, or reciprocation transversely of the machine.

The shaft 71 is rocked by means of a single crank arm 77 keyed thereto intermediate the ends thereof. This crank arm 77 is pivotally connected by a clevis fitting 78 to the forwardly extending piston rod of the screed elevating hydraulic ram 79. This ram 79 has its rear end pivotally supported at 80 on the forward end of the fixed central frame section 30. It will be apparent from a comparison of the full line and dotted line positions. of FIGURE 10 that the ram 79 can be actuated to quickly elevate the screed 22 when desired. This elevation of the screed will not interfere with the pitman arrangement 63 since the pitman rod will merely pivot during this elevation.

The diagonal screed 23 is shown best in FIGURES 1, 2, 7, and 8. The screed itself isof usual non-extensible rigid construction but is associated with the frame 20 of the machine, is reciprocated, is angularly adjusted, and is elevated, by a novel structural arrangement. In actual practice, as shown in FIGURE 8, this screed also rests on the side forms. The rear side of the screed is engaged adjacent each end thereof by means of the thrust rollers which operate within elongated guides 86 attached to the rear side of the screed, this arrangement being similar to that described for the screed 22. Each roller 85 is carried by a roller support bracket 87 (FIG- URES 1 and 7) which is secured to and depends from the. outer end of a tube 88 that telescopes into the adjacent end of the main screed-supporting tube 89. This main screed support 89 extends transversely of and is pivoted to the fixed central section 30 of the frame 20 by the depending pivot structure 99 which is shown best in FIGURES 1, 2 and 7.

The brackets 87 face outwardly and straddle the edges of the inwardly facing arcuate guide and bearing plates 93 carried by the movable frame sections 32. To provide for movement of the roller-supporting brackets 87 with the adjustable side sections 32 of the frame so that the rollers 85 will always engage the screed adjacent the sides of the machine and, therefore, adjacent the side forms, the brackets 87 are provided with the capscrews 91 which operate in arcuate guides 92 carried by the plates 93. Each section 32 (FIGURES 2, 15 and 16) is provided with a plate 93 rigidly secured thereto that has the guide slot .92 formed therein adjacent its outer edge. The capscrews 91 operate in this slot 92 and their caps rest on the brackets 87. When the screed support 89 is swung about the pivot 90, the capscrews 91 will operate in this guide slot 92. Thus, swinging of the screed will be permitted regardless of the adjusted positions of the side frame sections 32. Furthermore, extension of the frame sections 32 relative to the main section 3% will be permitted and will move the brackets 37 with them since the tube support members 88 will telescope in and out of the main tube support 8?. Thus, the screed support and guide structure will always be at the sides of the machine where they will function most effectively.

The angular position of the screed 23, as will be understood from the above, is determined by the adjustment of the screed support tube 89 about the pivot 92') carried by the frame section 30. This adjustment is accomplished by means of a pair of hydraulic rams 100 and 101. These rams are rigidly carried by the rear frame member 33 (FZGURES 2 and 7) of the fixed central frame section 38. The rams 100 and 181 extend forwardly and the piston rods thereof are provided at their forward ends with universal thrust bearings 102 associated with the ends of the screed support 89. Thus, by selectively actuating rams 100 and 101, the angular position of the screed 23 about the pivot 90 can be controlled readily.

The elevating means for this screed 23 is similar to that described for the forward screed 22. This means includes the depending links 103 which are provided with cradle rollers 194 beneath the support rods 165 which extend longitudinally of the screed. The upper ends of the links 193 are pivotally connected to the pair of crank arms 166 which are keyed on the outer ends of a transversely eX- tending rockable shaft 197. The shaft 107 is rotatably supported by a pair of forwardly extending brackets 103 which are rigidly secured to the main screed support 89 towards the ends thereof and an intermediate support bracket 113 rigidly attached to the member 89 and extending upwardly therefrom. This shaft 107 is rocked by means of a crank arm 109 keyed thereto intermediate its ends and extending downwardly and rcarwardly. The outer end of this arm 113-? is pivoted at 11(l to the piston rod of a hydraulic ram 111. This ram 111 has its rear end pivoted at 112 to the supporting bracket 113. Thus, by proper control of the ram 111, the screed 23 can be elevated, as indicated by a comparison of the full line and dotted positions of FIGURE 8, and thus elevation will not interfere with the crank and pitman reciprocating arrangement now to be described.

The screed 23 is reciprocated by a pitman arrangement 115 (FIGURES 2, 7, and 13) and this will not interfere with the elevating mechanism since the pitman structure will merely pivot during elevation of the screed. This pitman structure 115 is driven by means of a shaft 116 which is supported by the central fixed section 31) of the frame. The shaft 116 is driven by a chain and sprocket drive 117 which is driven by the shaft 64 previously mentioned. Between the pitman arrangement 115 and the shaft 116, which is on the fixed support, is a flexible coupling or universal joint 119 which will permit the angular adjustment of the screed 23 Without interfering with the drive.

As previously indicated, the transporter wheel units 24 are provided for the purpose of transporting the machine to different locations. These units 24 are illustrated best in FIGURES l, 2, and 9. Each unit 24 is associated with one of the transversely extending forward or rear tube supports 33 of the fixed frame section 30 of the machine. Each unit comprises a Wheel 125 preferably of the pneumatically tired type which is carried by a yoke 126 that is rigidly attached to a triangular plate 127. This plate 127 is pivoted on a horizontal pivot 128 which is provided at the upper side of the tube 33. By swinging the plate 127 about the pivot 128, the wheel 125 can be raised or lowered relative to the member 33 and the frame section 30, as indicated by a comparison of the dotted and full line positions of FIGURE 9.

For rocking the plates 127 about their respective pivots 128, hydraulic rams 129 and 130 are provided. Each ram 129 or 130 is pivoted for vertical swinging movement to the associated frame member 3-3 at the point 131. The outer end of the piston rod of each of the rams is pivoted at 132 to the outer end of the associated plate 127. Thus, by proper control of each of the rams 129 and 130 the selected wheel 125 can be raised or lowered relative to the associated frame member 33. The pivots 128 of the two Wheel units are in lateral alignment with each other and are preferably so located that when the wheels are lowered a line passing through their axles will be to the left of the longitudinal center line of the machine so that the center of gravity of the machine will be to the right of the frame of the machine.

To aid in removing the machine from the side forms for transportation, a hydraulic jack 25 is associated with the right hand side of the machine, as previously indicated. During operation of the machine on the side forms, this jack is in inoperative or dotted line position shown in FIGURE 12. The jack is in the form of a ram which is pivoted at 135 to the side beam 36 of the side rame section 32. It is normally locked in its uppermost position by means of a latch pin 136 which is extended through aligning openings and lugs depending from the member 36 and projecting from the corresponding side of the cylinder of the ram. When the pin 136 is released, the ram 25 will swing down into the full line position shown in FIGURE 12. It is automatically locked in such position by a latch 137 pivoted to the member 36. By proper control of the ram 25, when it is in the full line position shown in FIGURE 12, the right hand end of the frame may be lifted to clear the tramming wheels 21 at that side of the form. Thus, if the ram 25 and the wheel units 24 are properly controlled relative to each other, a three point support of the machine can be obtained so as to lift all of the tramming wheels 21 from the side forms.

To pull the machine transversely off the side forms, the draught tongue structure 26 is provided at the right hand side of the machine. This tongue 26 is pivoted to the side frame member 36 at 140 for vertical swinging movement. it it normally locked in its upper inoperative position, during use of the machine on the side forms, by means of a bar 141 which is pivoted at its outer end to the outer end of the tongue 142 and which is connected at its inner end by a removable lock pin 143 to the upstanding lugs 144 carried by the frame member 36. To swing the tongue 26 down into operative position, it is merely necessary to remove the pin 143 to release the bar 141. It can then be locked rigidly in horizontal position by means of a removable pin 145 which cooperates with lugs 146 carried by the member 36 and adapted to receive the inner end of the bar 141. The raised right hand end of the machine can then be supported by means of the tongue 26 which will be attached to a pivot lug on a truck or tractor by a pin or bolt passing through an opening 147 in the outer end of the tongue.

The platform 31 on the frame section 30 will carry the power unit of the machine which in this instance is illustrated as an internal combustion engine 150 that is shown in FIGURES l, 2 and 14. This engine through a sprocket and chain drive 151 (FIGURE 14) is shown as driving two hydraulic pumps 152 and 153 disposed in tandem although a different number of pumps may be used if desired to obtain the necessary hydraulic pressure for operating all the hydraulic units of the machine. These pumps withdraw hydraulic fluid from the supply tank 154 which is also carried by the platform 31. For controlling all of the hydraulic units, a bank of valves is provided on an upstanding console 155 which is located at the front edge of the platform 31 as shown in FIG- URES 1 and 2, and each of these valves is operated by an upstanding hand lever 156.

The hydraulic system for operating the various hydraulic units is illustrated diagrammatically in FIGURE 17.

The pump 152 is a pump comprising two units in tandem. The pump 153 comprises three units in tandem.

The pump 152 is provided with two pressure outlet lines 161 and 162, connected to the respective units thereof, and with a common inlet line 164. The line 164 connects to the supply tank 154. The line 161 connects to one end of a group 150 of valves and a return line 163 connects to the other end of the group and to the tank 154.

Starting at the right hand side of the group of valves 160 in FiGURE 17, it will be noted that the valve 175 controls the hydraulic jack 25. This valve 175 is a fourway threeposition valve and will be spring loaded to return to neutral but can be shifted in one direction to raise the jack and in the other direction to lower the jack. The valves 176, 177, 178, 179, and 189, now to be discussed, will be of the same type, having a neutral position and operative positions on either side of neutral, being spring-returned to neutral. The next valve 176 is connected to the ram 129 for controlling one of the wheel units 24. This valve will be of a similar type and can be moved from neutral into one position or the other to raise or lower the wheel of the unit 24 which it controls. The next valve 177 is connected to the ram 130 which independently controls the other wheel unit 24. The next valve 178 is connected to the ram 111 which controls elevation of the diagonal screed 23 and can be moved from neutral position in either direction to either raise or lower the screed. The next valve 179 is connected to the ram 79 for raising or lowering the screed 22. The next valve 181) is connected to the rams 100 and 101 which control the angular position of the screed 23. This valve will permit fluid to flow back and forth from the pressure sides of the rams 100 and 101. The opposite sides of the rams 1% and 101 are connected by a line 181. Therefore, the valve 180 can be moved from neutral in either direction to change the angle of the screed 23. The next valve 182 is connected to the screed reciprocating motor 67. The next valve 183 is also connected to themotor 67. Between the valves 182 and 183, the pressure line 162 from the pump 152 is connected to the group of valves 160. Valves 182 and 183 are identical and each is a two-position four-Way valve. Each valve is a detent type and can be moved from neutral into detent position to drive the motor. The valves 182 and 183 are so connected in the system that valve 182 is forone speed, valve .183 is for another speed, and the two valves operate-d together provide for a third faster speed. Thus, the screeds 22 and 23 can be reciprocated at selected speeds.

One of the pressure lines 165 from the pump 153 runs to one end of the group of valves 166, another pressure line connects to the group intermediate the ends thereof, and the other pressure line 168a connects to another group of valves 168. A common return line 169 leads from the valve groups 166 and 168 to the tank 154. A common inlet line 170 leads from the tank 154 to the sections of the pump 153.

Starting at the left of the group 166 in FIGURE 17,

the valve 185 is connected to a line 186 which joins the pressure ends of the rams 40 and its opposite side is connected to a line 187 which joins the opposed ends of the rams, these rams controlling extension of one side section 32 of the frame, as previously indicated. This valve 185 is a four-way, three-position valve, being spring loaded into neutral. Moved one way from neutral it will extend the frame, section and the other Way will contract the frame section. The next valve 188 is of the same type and one side is connected by a line 189 to one end of the rams 41, for the other frame section, and the other ends of the rams are connected together by a line 190. These valves 185 and 188 can be operated independently to extend or contract either of the side frame sections 32. The next valve 191 is connected to the trarnming motor 46 and is a four-way three-position valve which has a neutral position, a detent forward position, and a detent reverse position. The next valve 192 is of the same type and connects to the tramming motor 45. The pump pressure line 167 connects between this valve and the next valve 193. The valves 193, 194, 195, and 196, now to be discussed, are of the same type as the valve 191. The valve 193 also connects to the motor 46 and the next valve 194 also connects to the motor 45. The next valve 195 connects to the motor 46 while the succeeding valve 196 connects to the motor 45. For one speed of the machine the valves 193 and 194 are actuated to drive it forwardly or in a reverse direction, both tramming motors operating at the same speed. Valves 191 and 1212 can be used for another speed and a third speed can be selected by using the valves 195 and 196. The valves for either motor 45 or 46 can be selected relatively to obtain differences in speed at the two sides of the machine. Any combination of the three valves at either side can be selected and it is thus possible to obtain seven forward speeds or seven reverse speeds.

It will be apparent from the above description that we have provided a machine for finishing pavement surfaces which is completely hydraulically controlled. The machine is moved along the pavement by tramming wheels which are driven by hydraulic motors that can be controlled independently to aid in steering the machine. The frame is composed of telescoping tubular sections which are telescoped and extended by hydraulic units which are independently controllable for operating the telescoping structure at either side. Thus, adjustments in accordance with variations with the pavement can be readily made. .The machine includes thqforward screed which is reciprocated by a hydraulic motor and which is elevated by a hydraulic unit. a rearscreed which is reciprocated by the same motor and is elevated by an independent hydraulic unit. The angular position of the rear screed is controlled by bydraulic'units and the extension or contraction of the frame is permitted regardless of the angular position of the screed. For transportation, hydraulically actuated transporting wheel units are provided and an elevating hydraulic jack is associated therewith.

it is apparent that this machine can be controlled easily by a single operator who can concentrate on the material finishing operation rather than on making the various adjustments which in a machine of this general type ordinarily are difiicult to make and require considerable concentration and time of the operator.

According to the provisions of the patent statutes, the principles of this invention have been explained and have been illustrated and described in what is now considered to represent the best embodiment. However, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

Having thus described our invention, what we claim is:

l. A pavement material working machine comprising a frame, traction means for supporting the frame for movement longitudinally along pavement material so as to work the material, said frame including a main central section and a side section at each side thereof, means etween each side section and the central section for connecting them together for lateral extension and retraction of the side section relative to the central section, a screed support carried by said frame, said screed support being pivoted to the said central frame section for movement about a vertical axis, interconnecting guide and support portions carried by the screed support and each side frame section, respectively, the guide and support portion carried by the screed support being connected thereto for movement laterally of the central frame section in accordance with lateral extension and retraction of the It also includes I cooperating side frame section, said means for connecting the frame sections together comprising telescoping frame members, said main screed support comprising a main central portion having telescoping end portions, said main central portion being pivoted to said main frame section at said vertical axis, said guide and support portions being carried by the side frame sections and the cooperating end portions of the screed support, said telescoping end portions of the Screed support carrying thrust rollers which are mounted on vertical axes and which engage the rear side of the screed to take the thrust exerted against the screed, said thrust rollers being carried by support brackets for rotation about said vertical axes, said brackets carrying said guide portions which are in the form of guide members that operate in arcuate guide slots on guide members carried by said frame side sections.

2. A machine according to claim 1 in which said arcuate guide slots are in guide plates carried by said side frame sections, said telescoping end portions being below said plates and the brackets carried thereby carrying the guide members which extend upwardly into said slots and are provided with cap portions which rest on the guide plates.

3. A pavement material Working machine comprising a frame, traction means for supporting the frame for movement longitudinally along pavement material so as to work the material, said frame including a main section and a side section having traction means connected to the outer side of each, means between the two sections for connecting them together for lateral extension and retraction to thereby adjust the lateral spacing of said traction means, a'screed support carried by said frame, said screed support including a main portion pivoted to the main frame section for movement about a vertical axis and an end portion connected thereto for extension and retraction relative thereto, a screed carried by said main portion of the support, a laterally adjustable connection between said end portion of the support and said screed, and laterally interlocking but arcuately slidable guide and support portions carried by the end portion of the screed support and the frame side section for permitting supported arcuate swinging of the screed support end portion relative to said frame side section and so that said screed support end portion will extend and retract laterally with said frame side section in accordance with lateral extension and retraction of said frame side section relative to said main frame section in order that said guide and support portions will be adjacent said traction means of said frame side section regardless of the lateral position of said frame side section.

4. A pavement material working machine comprising a frame, traction means for supporting the frame for movement longitudinally along pavement material so as to work the material, said frame including a main central section and a side section at each side thereof having traction means connected to the outer side of each, means between each side section and the central section for connecting them together for lateral extension and retraction of the side section relative to the central section to thereby adjust the lateral spacing of said traction means, a screed support carried by said frame, said screed support including a main portion pivoted to the central frame section for movement about a vertical axis and an end portion connected to each end thereof for extension and retraction relative thereto, a screed carried by said main portion of the support, a laterally adjustable connection between each of said end portions of the support and said screed, and laterally interlocking but arcuately slidable guide and support portions carried by each end portion of the screed support and the cooperating frame side section for permitting supported arcuate swinging of the screed support end portion relative to said frame side section and so that said screed support end portion *will extend and retract laterally with said frame side section in accordance with lateral extension and retraction of said frame side section relative to said central frame section in order that said guide and support portions will be adjacent said traction means of said frame side section regardless of the lateral position of said frame side section.

5. A machine according to claim 4 in which said means for connecting the frame sections together comprise telescopirig frame members, said main portion of the screed support having the end portions telescoping therewith, said connection between each of said end portions of the support and the frame comprising thrust rollers which are mounted on vertical axes on said end portions and which engage the rear side of the screed to take the thrust exerted against the screed, laterally extending guides carried by the rear of the screed in which said rollers move upon relative lateral movement of the screed and end portions of the support, said guides being vertically movable relative to said rollers to permit elevation of the screed relative to said screed support, and means carried by the main portion of the screed support for elevating said screed.

References Cited in the file of this patent UNITED STATES PATENTS 1,662,257 Valerio Mar. 13, 1928 1,840,970 Noble Jan. 12, 1932 1,932,601 Price Oct. 31, 1933 2,054,263 McCrery Sept. 15, 1936 2,426,703 Millikin et a1 Sept. 2, 1947 2,681,231 Kondracki June 15, 1954 OTHER REFERENCES Construction Methods and Equipment, March 1954, volume No. 36, pp. 164, 166 and 168.

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