US3442189A

US3442189A - Concrete spreader

Info

Publication number: US3442189A
Application number: US579667A
Authority: US
Inventors: Maurice E Robinson; Robert E Jokinen
Original assignee: Cleveland Equipment Corp
Current assignee: Cleveland Equipment Corp
Priority date: 1966-09-15
Filing date: 1966-09-15
Publication date: 1969-05-06
Anticipated expiration: 1986-05-06

Description

y 6, 1969 M. E. ROBINSON ETAL 3,442,189

CONCRETE SPREADER Filed Sept. 15, 1966 Sheet of4 ATM 5. & Gen/6'.

y 1969 M. E. ROBINSON ETAL 3,442,189

CONCRETE SPREADER Filed Sept. 15, 1966 Sheet 3 of 4 M 50 5:735; 5472145405 firf/. (2 (4/9.

y 1969 M. E. ROBINSON ETAL 3,442,189

CONCRETE SPREADER Filed Sept. 15, 1966 7-7 7 I INVENTORS Maurice Z-xfiobzhsazz Hobart 5: J lfi'nezz United States Patent 3,442,189 CONCRETE SPREADER Maurice E. Robinson, Livonia, and Robert E. Jokinen, Taylor, Micl1., assignors to Cleveland Equipment Corporation, Garden City, Mich., a corporation of Michigan A Filed Sept. 15, 1966, Ser. No. 579,667 Int. Cl. E01c 19/48; B65g 15/00, 17/00 US. Cl. 94-46 6 Claims ABSTRACT OF THE DISCLOSURE Apparatus for spreading concrete onto a road bed and including a carriage having a central frame and extensible and retractable side frames. The carriage supports an endless belt which has a carrying run that is at all times coextensive with the length of the frame and a traveling plow having drive means which are extensible and retractable to accommodate adjustment of the side frames on the central frame.

This invention relates to apparatus for spreading concrete over a given area, and more particularly to apparatus for automatically uniformly distributing concrete over a given area, such as a roadbed or the like.

It is one object of the present invention to provide apparatus for spreading concrete over a given area, such as a roadbed, which is adapted to receive concrete at one location and to automatically distribute the concrete uniformly over the roadbed.

It is another object of the invention to provide apparatus for uniformly spreading concrete over a roadbed which apparatus is readily adjustable for use on roadbeds of different widths.

It is another object of the invention to provide apparatus for automatically spreading concrete in uniform distribution transversely across a roadbed wherein the distributed concrete is struck off by the apparatus to a predetermined roadbed contour.

The foregoing, and other objects, are achieved in an apparatus which includes a carrage adapteid to be supported upon and driven in movement along the raillike forms which define the sides of a roadbed. The carriage is constructed with a central frame portion and opposite side frames which are telescopically mounted within the central frame so that the width of the carriage can be adjusted to the desired width of the roadbed on which the apparatus is to be used. An endless conveying belt extends transversely across the entire width of the carriage and is driven by a reversible drive motor, so that the upper or carrying run of the belt can be driven in either direction, thereby permitting concrete to be loaded onto the belt from either side of the machine. A concrete receiving hopper is mounted above the belt at the side from which concrete is to be received, and the carrying run of the belt is driven in a direction carrying concrete discharged onto the belt from the hopper transversely across the carriage toward the opposite side of the roadbed. A travelling plow is mounted upon the carriage for movement in either direction transversely across the carriage. A deflector plate on the travelling plow overlies the conveyor belt to the deflect concrete from the belt rearwardly from the carriage. In operation, the belt is driven at a constant speed, and the travelling plow is driven automatically in back-and-forth movement at uniform speeds from one side of the carriage to the other, thereby deflecting concrete from the conveying belt in uniform distribution transversely of the roadbed. A wiper arm is supported above the carrying run of the conveyor belt on the opposite side of the carriage to remove any concrete remaining on the belt.

The conveying belt and travelling plow drive means are so supported upon the carriage that transverse adjustment of the carriage to adapt the apparatus to a roadbed of a given width automatically increases or decreases the length of the carrying run of the belt and also the distance travelled by the travelling plow.

Concrete deflected from the belt is discharged onto the roadbed in front of a contoured strike-off plate carried by the carriage. Normally, a reservoir of concrete is maintained in front of the strike-off plate and forward movement of the carriage leaves a uniformly compacted and accurately contoured bed behind the carriage.

Means in the form of an arcuate plate are provided rearwardly of the belt and spaced from the side form below the hopper to direct the deflected concrete towards the roadbed immediately adjacent the form below the hopper.

Other objects and features of the invention will become apparent by reference to the following specification and to the drawings.

In the drawings:

FIGURE 1 is a front elevation of a concrete spreading apparatus embodying the present invention;

FIGURE 2 is a schematic view illustrating the relationship of the concrete conveying belt and pulleys of the apparatus of FIGURE 1;

FIGURE 3 is a schematic view showing details of the travelling plow drive means;

FIGURE 4 is a top plan view of the left portion of the apparatus of FIGURE 1;

FIGURE 5 is a detail cross-sectional view taken on approximately line 5-5 of FIGURE 4;

FIGURE 6 is an enlarged fragmentary side View as viewed from the hopper end of the conveyor;

FIGURE 7 is a transverse vertical sectional view taken along lines 77 of FIGURE 4;

FIGURE 8 is a schematic diagram of an electrical control circuit for the apparatus of FIGURE 1; and

FIGURE 9 is a schematic diagram of a hydraulic drive system for the apparatus.

General description Referring first particularly to FIGURES l, 4 and 5, a concrete spreader embodying the present invention includes a carriage, defined by a central frame designated generally 10 and left and right handled. side frames designated generally 12 and 14, respectively, as viewed in FIGURE 1 of the drawings. The carriage is supported for movement upon a roadbed by wheel assemblies designated generally 16 which are mounted in side frames 12 and 14 and adapted to ride along the tops of the retaining forms F which define the sides of the roadway upon which the concrete is to be spread. Each of side frames 12 and 14 is provided with a set of wheels 16 at both its front and rear ends. To adapt the carriage for use on roadbeds of different widths, the side frames 12 and 14 are telescopically received within central frame 10, by structure to be described below, so that the width of 3 the carriage may be adjusted in accordance with the width of the roadbed.

The apparatus further includes an endless belt conveyor designated generally 18 which extends transversely across the entire width of the carriage. Concrete to be distributed upon the roadbed is poured into a hopper designated generally 20 located at one side of the carriage which discharges the concrete onto the upper run of conveyor 18 which then conveys the concrete transversely across the roadbed. A travelling plow assembly designated generally 22 is mounted upon the carriage for back-and-forth movement transversely across the roadbed and is cooperatively associated with the upper run of the belt of conveyor 18, so that concrete is deflected from the belt at a location transversely of the roadbed dependent upon the transverse position of the travelling plow. By continuously feeding concrete onto the upper run of belt 18 and by continuously driving the travelling plow 22 back and forth across the entire width of the roadbed, an even distribution of concrete transversely of the roadbed is achieved.

Extending entirely across the roadbed at the rear of the carriage is a strike-off plate assembly designated generally 24 which, as the carriage is driven in movement along the roadbed, strikes off concrete previously poured upon the roadbed from the carriage in the manner best illustrated in FIGURE 5.

Central frame-side frame structure Central frame 10 consists of three transversely extending

frame subassemblies

26, 28 and 30. Each of

subassemblies

26, 28 and 30 is of substantially identical construction and of a cross sectional ocnfiguration typified by that of subassembly 30 in FIGURE 5. Subassembly 30 includes a middle frame member 32 of hollow, box-like configuration, and channel-shaped upper and

lower frame members

34 and 36, respectively. Near each end of each frame subassembly, side plates 38 are fixedly secured to the front and rear sides of middle frame member 32 and project above and below the upper and lower sides of frame member 32. As best seen in FIGURE 5, this arrangement provides a confined trackway within which are slidably received hollow, box-like upper and lower frame members 40 and 42 which are fixedly secured to the respective side frames 12 and 14, the reference numerals 40 and 42 being provided with subscripts R or L in the drawings, members 40R and 42R being rigidly fixed to right side frame assembly 14, while

members

40L and 42L are rigidly fixed to the left side frame member 12.

Frame members

32, 34 and 36 of each of the central frame subassemblies are fixedly secured to each other by a suitable number of vertical straps, such as 44, in the case of

subassemblies

26 and 30, by vertical box frame members 46, which are fixedly secured to

members

32, 34 and 36 by any suitable means such as welding. The three

subassemblies

26, 28 and 30 of the central frame are further secured to each other in parallel, spaced, frontto-rear relationship by suitable front-to-rear frame members, such as 48 (FIGURE 4), many of these front-torear frame members having been omitted from the drawings for sake of clarity. As indicated in FIGURE 4, three sets of upper and lower frame members 40, 42, are provided on each side frame 12 and 14, and in each case are slidably received in the

corresponding frame subassemblies

26, 28 or 30 of central frame 10.

It is believed apparent that the cooperative relationship between the

central frame subassemblies

26, 28 and 30, and the corresponding frame members 40 and 42 of the respective side frame assemblies enable the two side frame assemblies 12 and 14 to be moved toward or away from each other, within limits, by virtue of the sliding, guided interengagement between members 40 and 42 and the central frame subassemblies. This relationship permits the distance between wheels 16 on the respective side assemblies to be varied in accordance with the width or spacing between the forms F defining the side of the roadbed.

Because of the substantial weight of the structures involved, transverse adjustment of side frames 12 and 14 relative to central frame 10 is accomplished by the use of jacks, and normally a substantial amount of force must be exerted to shift the frame assemblies relative to each other. If necessary, clamp means, not shown, may be provided to lock the respective frames in their adjusted position relative to each other.

As best seen in FIGURE 1, vertical posts 46 are extended upwardly substantially above the upper run of conveyor 18 and support, at their upper end, a platform 50 which supports a gasoline motor driven generator assembly designated generally 52. For convenience, a control panel 54 has been schematically illustrated as being mounted upon the housing of motor generator 52. The machine operator stands on platform 50 during operation of the machine.

Concrete conveyor structure Conveyor 18 includes an endlesss belt 56 (FIGURES 1 and 2) whose upper run extends between end rolls 58 and 60, which are respectively mounted on the outboard sides of side frames 12 and 14. The upper run of the belt is supported on an extensible tray 59 which is carried intermediate the

subframe assemblies

26 and 28. A plurality of rollers 61 journalled on the side frame 12 support the carrying run of the belt 56 below the hopper 20 to provide additional support for the heavy load of the concrete within the hopper.

The lower run of belt 56 extends transversely inwardly from end roll 58 to a first direction changing roll 62 which is rotatably mounted between the inner ends of the two forward side frame members 42L. From roll 62, belt 56 then extends outwardly to a second direction changing roll 64 which is rotatably mounted between

central frame subassemblies

26 and 28 at the left-hand side of the central frame. Belt 56 then extends entirely across the central frame to a second direction changing roll 66 similarly mounted at the right-hand side of central frame 10, and thence inwardly to still another direction changing roll 68 which is rotatably mounted between the inner ends of the two forwardmost side frame members 42R. From roll 68, belt 56 then extends outwardly to end roll on the right-hand side frame.

The orientation of the belt, rollers, central frame and side frame is schematically illustrated in FIGURE 2. It will 'be noted from FIGURE 2 that direction changing rolls 64 and 66 are mounted upon central frame 10, and hence the distance between these rolls does not vary. End roll 58 and direction changing roll 62 are mounted upon the left-hand side frame 12, while end roll 60 and direction changing roll 68 are similarly mounted upon the right-hand side frame 14 Assuming that central frame 10 and side frame 12, referring to the schematic diagram of FIGURE 2, are held stationary, and that side frame 14 is moved to the right, movement of side frame 14 to the right will shift end roll 60 and direction changing roll 68 to the right by equal distances, because these two rolls are mounted upon side frame 14 in fixed relationship to each other. The increase in distance between end rolls 58 and 60 is automatically compensated for by the corresponding decrease in the distance between direction changing roll 68 and direction changing roll 66, thereby providing an automatic adjustment of the length of the upper or carrying run of belt 56 upon transverse adjustment of the side frames relative to the central frame.

In the disclosed apparatus, end roll 58 is constituted as the driving roll of conveyor 18 by coupling roll 58 (see FIGURE 6) to an electric motor 70, mounted in side frame 12, by means of a chain and sprocket connection designated generally 72. Preferably motor 70 is a reversible motor, so that the belt may be driven in either direction. As shown, hopper 20 from which concrete is deposited on the belt is located at the left-hand side of the machine and in this case movement of the upper run of belt 56 would be to the right, as viewed in FIGURE 4.

In the event it is inconvenient to load from the left-hand side, hopper 20 may be mounted on the opposite or righthand side of the machine, in which case it would be necessary to reverse the direction of drive of belt 56.

Hopper The hopper 20 is ilustratively shown as a sectionalized member and, as shown in FIGURE 6, includes a central section 73 and oppositely disposed end sections 74. The central section 73 includes a pair of spaced plates 75 one which is provided with an opening 76. Means are provided for regulating the amount of flow from the hopper onto the conveyor belt and, in the illustrated embodiment, the regulating means includes a plate 77 vertically adjustable on the inner side of the plate 75 having the opening 76. The plate 77 is provided with an elongated vertical slot 78 which receives a bolt 79 to maintain the plate 77 in vertical adjusted position with respect to the opening 76 thereby regulating the flow of concrete from the hopper onto the conveyor belt.

The outer sections 74 of the hopper are movably interconnected to the center section 73 for movement toward and away from the center section to force the concrete towards the center section 73 and the opening 76. In the illustrated embodiment, the outer sections 74 are connected to the center section 73 by a hinge 80 with means for moving the sections 74 from the solid lines shown in FIGURE 6 to the dotted line position of FIGURE 6. The moving means may be an electric motor and suitable connections or a hydraulic system, which is illustratively shown and includes a pair of fluid cylinders 81, each pivotally secured through a lug 82 to the frame section 12. The free ends of piston rods 83 are pivotally connected to the sections 74 through second lugs 84. Suitable fluid pressure may be supplied from a source, to be described later, through the appropriate ends of the cylinders 81 to thereby extend or retract the rods 80 and move the section 74 between the first and second positions.

Travelling plow Travelling plow 22 includes a flat platform 86 (FIG- URES 4 and 7) which is supported for movement transversely across the apparatus by four wheels 87 supported upon a pair of extensible spaced tracks 88 carried by upstanding frame members 89 and 90 which form integral parts of the respective side frame assemblies 12 and 14, respectively (FIGURE 1). A deflector plate 91 is secured to the lower surface of the paltform 86 with the lower edge of plate being supported closely adjacent the upper surface of belt 56. The function of deflector plate 91 is to deflect concrete carried on the upper run of belt 56 rearwardly onto a discharge chute or plate 92 which is an extension of the tray 59 and extends from the tray rearwardly and downwardly beyond frame subassembly 28 to discharge concrete from belt 56 into the space between

frame subassemblies

28 and 30.

Deflector plate 91 is detachably mounted in a fixed position upon platform 86, so that its inclination relative to the belt can be reversed from that shown in FIG- URE 4, in the event concrete is fed from the opposite end of conveyor 18. The lower portion of the deflector plate may be in the form of a removable resilient member 93 engaging the upper surface of the belt 5 6.

Travelling plow 22 is driven in movement transversely of the apparatus by a cable arrangement best shown schematically in FIGURE 3. Each end of the travelling plow is coupled to one end of a cable, one cable 94 extending from the left end of the plow, as viewed in FIGURE 3, around a direction changing pulley 96 which is mounted upon the upstanding frame member 89 (FIGURE 1) which forms an integral part of left side frame assembly 12. From pulley 96, cable 94 is extended to a drum 98 mounted for rotation upon the platform 50 of central frame 10. Cable 94 is wrapped about drum 98 with several turns and its end is fixedly attached to drum 98.

A mirror image cable arrangement is connected to the opposite end of plow 22, with a second cable 100 being trained around a direction changing pulley 102 mounted upon an upstanding frame member fixedly secured to right side frame assembly 14. Cable is then wrapped in several turns about a second drum 104 rotatably supported upon central frame 10. The two drums are rotatably coupled to each other as by a belt and pulley arrangement designated generally 106, so that the two drums rotate simultaneously in the same direction and at the same speed when drum 104 is driven in rotation by a reversible drive designed 108. Because

cables

94 and 100 are wrapped in opposite directions about their respective drums, as cable is unwound from one drum, the other cable is wound onto the other drum. For example, if drums 98 and 104 are simultaneously driven in a clockwise direction as viewed in FIGURE 3, cable 100 will be wound onto drum 104, while at the same time, cable 94 will be unwound from drum 98 by an equal amount. Winding of cable 100 onto drum 104 draws travelling plow 22 to the right, as viewed in FIGURE 3, this action being permitted by the corresponding unwinding of cable 94 from drum 98. To drive travelling plow 22 in the opposite direction, the direction of rotation of the two drums is reversed.

The excess cable wound on the respective drums permits automatic compensation of the distance travelled by the travelling plow, when side frames 12 and 14 are transversely adjusted relative to central frame 10. As the adjustment is made, the drive coupling between drive 108 and drum 104 is temporarily disconnected and as the side frames move outwardly, cable is unwound from the drums to compensate for the increased spacing.

The travelling plow is normally driven in automatic cyclic movement under the control of control circuits to be described below. To automatically reverse the direction of travel of travelling plow 22 when it approaches one side of the apparatus, limit switches LS1 and LS4 are mounted upon a frame member 89 of left side frame 12, and limit switches LS2 and LS3 are mounted upon the corresponding frame member 90 of right side frame 14. Limit switch actuating members are mounted upon suitable post assemblies such as 110 and 112 fixed to the travelling plow and provided with actuators such as A1, A4, respectively located upon post 110 to actuate limit switches LS1 and LS4, and actuators A2 and A3 mounted upon post 112 to respectively actuate limit switches LS2 and LS3.

The control circuit, to be described below, also includes means for temporarily halting the travelling plow when it reaches the most leftward position adjacent the hopper 20. When the travelling plow 22 is at its most leftward position and is halted, the concrete passing from the chute is forced outwardly beyond the discharge chute or plate 92 towards the lefthand side of the roadbed. To insure that some concrete is deflected towards the left edge of the roadbed, means are provided for directing the deflected concrete toward the edge: of the roadbed when the travelling plow is halted at the left-hand side of the carriage.

This means is illustratively shown as an arcuate plate 114 (FIGURES 4 and 7) fixedly secured to the discharge chute or plate 92. The arcuate plate 114 has one end in alignment with the associated end of the deflector plate 91, in its most leftward position, and the opposite end curved and directed towards the form F disposed below the hopper side of the carriage. In this manner, when the travelling plow and deflector plate are halted at the most leftward position, the deflector plate 91 has its rearward end in alignment with the arcuate plate 114 and, with concrete being forced out of the opening 76 in the hopper 20 and directed rightwardly by the continuously moving conveyor belt 56, the concrete strikes the deflector plate 91 directing it rearwardly towards the roadbed. The

arcuate plate 114 re-directs the concrete towards the side edge of the roadbed formed by the form member F.

The opposite side of the carriage is also provided with wiper means which will deflect any concrete remaining on the belt after it has passed the deflector plate of the plow means 22. The wiper means includes a plate 116 supported on the lower surfaces of the spaced tracks 88. The wiper plate or arm 116 is disposed at an angle to the upper surface of the belt and has an engaging portion 118 which may be in the form of a resilient member for constantly engaging the upper surface of the belt 56. The wiper means will insure that all concrete or other material deposited upon the belt will be removed therefrom before the belt begins its return pass below the roller 60.

Strike-off plate Strike-off plate assembly 24 includes an elongate plate 120 which extends transversely of the apparatus for the entire width between the roadbed defining forms F and is shaped with a lower edge 121 corresponding to the desired cross section of the roadbed surface. In the usual case, the strike-off plate is fabricated for the particular roadbed. However, if desired, the strike-off plate may be a sectionalized member having end portions 121a and 1211; which have arcuate lower surfaces and a central portion 121c telescopingly received in openings of the end portions 121a and 1211) although the central portion of the roadbed will be fiat when the carriage is in the extended position, this arrangement will be satisfactory when placing a first rough layer of concrete on the roadbed.

Plate 120 is supported at opposite sides of central frame 10 by upwardly projecting screws, such as 122, which are fixedly secured to the plate as by a bolt and bracket assembly 124 (FIGURE 5) and are threadably received within a nut 126 rotatably supported in central frame 10.

In one form of the invention, a reversible electric drive motor 128 is coupled to drive nut 126 by means of a bevel gear coupling designated generally 130. In FIGURES 4 and 5, only the screw 122 at the left-hand side of the machine is shown, a similar screw 122 and nut 126 assembly being located at the corresponding position at the opposite or right-hand side of central frame 10. The screw and nut assembly (not shown) is driven from motor 128 by a bevel gear and shaft arrangement designated generally 132. Rotation of motor 128 in one direction rotates the two nuts 126 to lift strike-off plate 120 upwardly, while rotation of motor 128 in the opposite direction reverses the direction of rotation of the nuts to lower plate 120.

As best seen in FIGURE 5, during normal operation of apparatus, concrete will be piled upwardly in front of strike-off plate 120. To prevent piled up concrete from discharging over the sides and top of forms F, a depending skirt plate 134 is fixedly secured to each side frame to project downwardly from the side frame to a location below the top of form F. Plate 134 is located transversely of the apparatus, so that it is in sliding contact with the inner side surface of form F. Skirt plate 134 extends forwardly from strike-off plate 120 a sufiicient distance to prevent concrete piled up in front of plate 120 from spilling over the top of the forms.

Traction drive Many forms of suitable traction drives are available for driving the apparatus in movement along forms F. In view of the fact that wheels 16 are mounted in the respective side frames 12 and 14 which are transversely adjustable relative to central frame 10, it is preferable that a drive be employed which does not require a direct mechanical driving connection between the wheels and a prime mover located upon the central frame. In FIG- URES 1 through 7, inclusive, the drive means for traction wheels 16 takes the form of a reversible motor 170 associated with each of the four sets of wheels and coupled to the wheels through a suitable chain and sprocket drive connection schematically illustrated at 172 in FIGURE 4. The length of the electric power cables by means of which electric power is supplied from motor generator set 52 to the individual drive motors can readily compensate for transverse adjustment of the side frames relative to the central frame.

In FIGURE 9, a somewhat modified form of control and drive means for the apparatus is disclosed, in which embodiment, individual reversible hydraulic motors 170H are substituted for the electrical motors 170.

Operation In FIGURE 8 is disclosed a schematic electrical control diagram for controlling operation of the various electrical motors employed in operating the FIGURES 1 through 5 embodiment. The portions of the circuit which control the traction, belt, plow, strike-01f and hopper motors are indicated by the barckets at the right-hand side of the diagram, the reference numeral referring to the specific motor or motors involved being indicated in parentheses beneath the appropriate legend.

Traction drive motors 170 are reversible and controlled by two alternatively energized

relays

1F and 1R, relay 1F being energized to cause motors 170 to drive the apparatus in a forward direction, while relay 1R energizes motors 170 to drive in the reverse direction.

Conveyor belt drive motor 70 is controlled by relay 3M, the electrical connections to the belt motor for driving in the forward or reverse direction having been omitted from the drawing.

Relay 3R and timing relays 1TR and 2TR are control relays employed during automatic cyclic operation of travelling plow 22.

The travelling plow drive motor 108, like the traction drive motors 170, is controlled by forward and reverse

relays

4F and 4R, respectively. Strike-off motor 128 is controlled by two relays, SU and SP, respectively energized for upward or downward movement of the strike-off blade.

The hopper sections may be moved by a reversible electric motor (not shown) which is controlled by upward and downward relays 6U and 6D, respectively, energized by switches in the respective circuits of the relays.

In preparing the apparatus for operation, side frames 12 and 14 are transversely adjusted relative to central frame 10 in accordance with the width of the roadbed as defined by the distance between the opposite side forms F. As described above, in connection with the detailed description of conveyor 18 and travelling plow 22, this adjustment of the frame automatically adjusts the conveyor and travelling plow drive arrangement. After the frame of the machine has been adjusted, receiving hopper 20 is opened, and the electrical connections to conveyor belt drive motor are set so that conveyor belt 56 will be driven in the proper direction.

Movement of the apparatus along the trackway defined by forms F is controlled by manually operable push buttons FWD and REV, respectively connected in series with relays 1F and IR. To cause the apparatus to drive in the forward direction, push button FWD is pressed to close its contacts, thereby completing a circuit across supply lines L1 and L2 through the normally closed contacts of stop button and the normally closed contacts 1Ra which are closed at all times except when relay IR is energized. When relay 1F is energized, it closes its normally open contacts 1Fa which bypass the manually actuated push button FWD, thereby locking in relay 1F to maintain relay 1F energized upon release of push button FWD. With relay 1F energized, traction motors 170 drive the apparatus in a forward direction. Forward driving movement continues until the manually operable stop button 180 is depressed to open the circuit to relay 1F.

Operation to drive in the reverse direction is similar, driving movement of drive motors 170 in the reverse di- 9 rection being initiated by manually depressing reversing button REV to energize relay 1R. Normally, the traction drive motors are employed only intermittently.

Conveyor belt drive motor 70 is started by depressing start button 182 momentarily to energize relay 3M. Once energized, relay 3M closes its lock-in contacts 3Ma which bypass start button 182. Once started, belt motor 70 will continue to drive until stopped by depression of the manually actuated stop button 184 which opens the circuit to relay 3M.

In normal operation of the machine, travelling plow assembly 22 is driven on an automatic cycle in which the plow assembly continuously drives from one side of the apparatus to the other in back-and-forth movement. As explained above, concrete which is to be poured upon the roadway is fed into the apparatus through hopper 20' onto the longitudinally central portion of belt '56 which conveys the concrete from hopper 20 in a ribbon or stream which extends from hopper 20 transversely across the apparatus to whatever point at which the travelling plow assembly 22 is located. The travelling plow is driven in constant speed movement and concrete is fed onto the belt from hopper 20 at a uniform rate. With belt 56 and travelling plow 22 moving at respective constant speeds, concrete will be deflected from the belt in uniform distribution transversely across the roadway. The speed of movement of travelling plow 22 is slower than that at which belt 56 is driven, so that when travelling plow 22 is moving in the same direction as the belt, the faster speed of the belt 56 continuously brings concrete into engagement with deflector plate 91. Because the relative speed between the belt and travelling plow is greater when the plow is moving in the direction opposite to that of movement of the belt, the amount of concrete dispensed or distributed on the roadway during a complete traversal of travelling plow 22 in a direction upstream of the belt will be substantially greater than that distributed during one complete transverse movement of the plow downstream of the belt. However, the rate at which concrete is dispensed or distributed onto the roadway is constant throughout each entire transverse movement of plow 22, although the rate obviously varies in accordance with the relative direction of movement of the belt and plow.

Preferably, both belt drive motor 70 and travelling plow drive 108 are provided with suitable speed adjustment means, not shown. In some instances, it may be desirable to drive the plow at one speed while it is moving in the same direction as the belt and at a different speed while it is moving upstream of the belt.

To condition the apparatus for automatic cyclic operation, a cycle start button 186 is depressed to energize a cycle relay 3R which then locks itself in through its control contacts 3Ra which bypass start button 186. In addition to depressing start button 186, a selector switch SS is shifted to its AUTO position to connect line L1 to point 188 in the control circuit to the plow drive control relays 4F and 4R, the circuit from line L1 going through the AUTO position of selector switch SS and also through contacts 3Rb which are closed upon energization of control relay 3R.

Automatic cyclic movement of travelling plow 22 between its end limits of movement is under the control of limit switches LS1, 2, 3 and 4, two of which are mounted respectively upon each of posts 89 and 90 on left and right side frames 12 and 14. Limit switches LS1 and LS2 each have a set of normally open contacts which are closed when the plow reaches one or the other end limit of movement, limit switch LS1 being located on post 89 on the left side frame 12, while limit switch LS2 is mounted in the corresponding position upon right side frame 14.

Limit switch LS1, when closed by movement of travelling plow 22 to its extreme limit of approach to left side frame 12, energizes a timing relay 1TR. Timing relay 1TR controls three normal or undelayed contacts one of which is a normally open lock-in contact lTRa connected in series with a normally closed contact Z'IRa to bypass the contacts of limit switch LS1 so that momentary closing of contacts LS1 energize relay ITR and lock it in through contacts lTRa and 2TRa. Subsequent movement of the plow away from left side frame 12 and the consequent opening of contacts LS1 have no effect on the energization of relay 1TR.

A similar circuit is employed to control the energization of relay 2TR, this latter circuit including normally open limit switch contacts LS2 and lock-in contacts 2TRb which are closed by the energization of relay 2TR and normally closed contacts lTRb.

The normally closed contacts 2TRa and lTRb automatically de-energize the timing relay to which they are connected upon energization of the other of the two timing relays. The energizing circuits of the two timing relays 1TR and 2TR are thus such that de-energization of one timing relay can be accomplished only by energizing of the other, and hence one of the two timing relays is energized at all times.

Assuming the plow 22 to be moving away from left side frame 12 and toward right side frame 14, relay ITR will be energized because the plow, at the conclusion of its movement toward left side frame 12, closed relay con tacts LS1 to energize relay 1TR and. lock-in contacts lTRa and 2TRa maintain relay 1TR energized upon the subsequent opening of contacts LS1 as the plow moved away from left side frame 12 toward right side frame 14.

Upon the energization of relay 1TR a time delayed closing of contacts lTRd was initiated. The delayed closing of lTRd temporarily halts the plow in its most leftward position. Upon the closing of contacts lTRd, energization of a plow control relay 4F was accomplished, since the closing of the delayed closing contacts lTRd completed the circuit from point 188 through normal closed contacts 2TRc, normal closed limit switch contacts LS3, and normally closed contacts 4Ras. Energization of relay 4F causes plow drive motor 112 to drive in a direction winding cable onto drum 104 and simultaneously unwinding cable from drum 98, thereby driving the travelling plow to the right, as viewed in FIGURE 1.

Driving of plow 22 toward right side frame 14, continues until limit switch actuators A2 and A3 strike their respective limit switches LS2 and LS3.

Actuation of limit switch LS2 closes its contacts to energize relay 2TR. Energization of relay 2TR immediately opens its contacts 2TRa, thereby de-energizing relay 1TR.

Actuation of limit switch LS3 opens its normally closed contacts, thereby breaking the circuit to relay 4F to stop driving movement of the plow drive 112. De-energization of relay 4F is further assured by contacts 2TRc which are opened immediately upon the energization of relay 2TR by the closing of limit switch contacts LS2.

Energization of relay 2TR after the reset time delay closes contacts 2TRd, thereby energizing plow control relay 4R via normal closed contacts lTRc, LS4 and normal closed contacts 4Fa, the latter contacts having closed immediately upon the de-energization of relay 4F. Energization of relay 4R causes plow drive 108 to drive in the opposite direction, winding cable onto drum 98 and simultaneously unwinding cable from drum 104, thereby driving the plow from right to left, as viewed in FIGURE 1.

Arrival of plow 22 at its leftward limit of movement, as viewed in FIGURE 1, closes limit switch contacts LS1 and opens contacts LS4 to de-energize relay 2TR and simultaneously energize relay lTR to reverse the direction of drive of travelling plow.

In the event it is wished to manually control the movement of travelling plow 22, selector switch SS is switched from the AUTO position shown in FIGURE 6 to the .I-IAND position. With selector switch SS in this position,

manually operable contacts F and R replace the time delayed closing contacts lTRd and 2TRd in the energizing circuits to the plow control relays 4F and 4R. Hand operation of the plow control permits the plow to be stopped at selected points in the event an uneven distribution of concrete is desired.

Strike-off motor 128 is controlled to drive in up and down movement, respectively, by relays SU and D which are respectively energized by manually operable push button switches UP and DOWN. Normal closed contacts 5Da and 5Ua are connected in the respective energizing circuits of relay SU and 5D to prevent simultaneous energization of both relays.

The circuit disclosed in FIGURE 8 illustrates a suitable control circuit for controlling operation of the apparatus wherein the various driving movement of the traction, belt, plow, strike-off device and hopper sections is by electrical motors.

In FIGURE 9, there is shown an exemplary schematic diagram of an arrangement wherein the drive in traction, and of the plow, belt and strike-01f device, is under the control of hydraulic motors.

In the hydraulic drive arrangement, traction drive motor 170 and plow drive 108 are replaced by reversible rotary hydraulic motors schematically illustrated at 170H and 108H, respectively, in FIGURE 9. Belt drive motor 70 is likewise replaced with a rotary hydraulic motor 70H. Strike-ofi? drive motor 128 and the associated screw and nut connections are replaced by a pair of doubleacting hydraulic cylinders 128H.

Traction motor 170I-I is hydraulically connected to a source of hydraulic pressure such as the schematically illustrated PUMP of FIGURE 9 and a low pressure return or exhaust E by a three-position, four-way reversing valve 200. Valve 200 may take the form of any of a large number of commercially available valves of this type in which the valve spool is normally held in a centered position and is actuated to either of two end posi tions by electrical solenoids. In the FIGURE 9 embodiment, an electrical circuit generally similar to that in FIGURE 8 may be employed to control the various solenoids, in which case, the solenoids controlling valve 200 would correspond to relays 1F and IR of FIGURE 8 and would be controlled by the corresponding electrical circuitry indicated in FIGURE 8. When valve 200 is in the center or neutral position, the high pressure supply line 202 from the PUMP is connected directly within the valve to exhaust outlet E.

Plow motor 112H is controlled by a two-position solenoid actuated valve 204 whose solenoids correspond as indicated to

relays

4F and 4R of the FIGURE 8 embodiment. In the event it is desired to hold the plow stationary while the pump is in operation, a valve 206 may be connected in the branch conduit 208 connecting pressure line 202 to valve 204 to shut off flow through line 208.

In the hydraulic embodiment, a common branch line 210 is connected to supply pressure from pressure line 202 via conduit 212 to belt motor 78, or alternatively via conduit 214 and a four-way reversing valve 216 to the strike-off drive motor 128H. A two-position valve 218, which may be controlled by solenoid 3M of the electrical circuit of FIGURE 6 is connected to act as a three-way valve to selectively connect line 210 either to line 212 or to line 214. Four-way reversing valve 216 is similar to reversing valve 200, with the exception that all of its ports are blocked when the valve is in its centered or neutral position. Valve 216 may be controlled by solenoids SU and 5D with appropriate circuitry, such as that illustrated in FIGURE 6. A shut-off valve 220 may be located in conduit 210.

The hopper sections 73 and 74 are moved relative to each other by a two-position solenoid actuated valve 221 whose solenoids correspond as indicated to relays 6U and 6D of the FIGURE 8 embodiment. The valve is connected by branch conduit 222 to pressure line 202 with a valve 224 in the branch conduit 222 to shut off flow through conduit 222.

While one form of structure and two alternative forms of controls have been disclosed, it will be apparent to those skilled in the art that the disclosed structures may be modified. Therefore, the foregoing description is to be considered exemplary rather than limiting, and the true scope of the invention is that defined in the following claims.

We claim:

1. Apparatus for spreading concrete on a roadbed comprising a carriage including first and second frame elements interconnected for lateral expansion and retraction of spaced free ends of said elements, an endless belt having a carrying run extending between said spaced free ends, a spaced pair of roller means secured to each of said elements and supporting said endless belt, said roller means being movable with said elements to vary the length of said carrying run to correspond to the spacing between said free ends, traveling plow means mounted on said carriage for movement along said carrying run for deflecting concrete from said carrying run onto the roadbed, reversible drive means on said carriage for said traveling plow means, cable means interconnecting said plow means and said drive means, and pulley means fixed on said first and second frame elements and supporting said cable means whereby extension and retraction of said elements increases and decreases the spacing between said pulley means to vary the effective length of said cable means.

2. Apparatus for spreading concrete on a roadbed comprising a carriage having a central frame and opposed side frame mounted for transverse movement relative to said side frame to increase or decrease the spacing of spaced free ends of said side frames for accommodating roadbeds of varying width, endless conveying means mounted on said carriage and having a flat carrying run extending transversely of said carriage between said free ends, a pair of rollers secured to each said central and side frames and supporting said endless conveyor whereby relative movement of said side frames on said central frame will vary the length of said carrying run, plow means supported on said carriage for movement along said carrying run between spaced free ends, drive means on said central frame for said plow means and extensible cable means connecting said drive means and said plow means.

3. Apparatus as defined in claim 2 in which said pair of rollers on each of said side frame includes an and roller adjacent said free end and a direction changing roller spaced from said free end whereby said end rollers define said carrying run, and said pair of rollers on said central frame respectively being disposed between an end roller and a direction changing roller of one of said side frames.

4. Apparatus as defined in claim 2 in which said drive means includes spaced drums on said central frame and said extensible cable means includes a direction changing pulley on each side frame and a pair of cables respectively connected to one of said drums and said plow means and supported by one of said pulleys whereby increasing or decreasing the spacing between said free ends varies the effective length of said cables.

5. In combination with a supporting frame having a central section and extensible and retractable side sections operatively connected to said central section for increasing and decreasing the effective length of said frame, an endless conveyor on said frame, end rolls on remote ends of said side sections supporting said conveyor and defining a carrying run, a traveling plow supported on said frame above said carrying run and adapted to deflect material from said traveling run, drive means fixed to said central section for driving said traveling plow, direction changing pulleys carried by the side section at said remote ends and extensible cable means having opposite ends respectively connected to said plow and said drive means and engaging said pulleys whereby extension and retraction of said side frames on said cen- 2,099,071 11/1937 Lundbye 198-188 tral frame varies the effective length of said cable means. 2,768,732 10/ 1956 Muhlen'bruch 198139 6. The combination as defined in claim 5, including 2,788,116 4/1957 Wood 198139 the further improvement of a direction changing roll on 2,962,949 12/1960 ODea 94-45 each side section inwardly of each end roll and a pair of 5 3,054,334 9/ 1962 Barber et a1. 9446 direction changing rollers on said central frame with OTHER REFERENCES each dlrectlon changlng roller disposed between the end roll and the direction changing roll of one of said side M g P b P 2, recelved 1967- frames' References Cited 10 JACOB L. NACKENOFF, Primary Examiner.

UNITED STATES PATENTS 1,967,178 7/1934 Jaeger 94-44