US2225481A - Road paver - Google Patents

Description

Dec. 17, 1940. A. E. LUNDBYE ROAD PAVER Filed Nov. 19, 1937 6 Sheets-Sheet 1 INVENTOR M 6 BY e d65 TTORNEYS Dec. 17, 1940. A. E. LUNDBYE ROAD PAVER 6 Sheets Sheet 2 Filed Nov. 19, 1937 INVENTOR ATTORNEY Dec. 17, 1940. A. E. LUNDBYE ROAD PAVER 6 Sheets-Sheet 3 Filed NOV. 19, 1937 ATisRiEY W Dec. 17, 1940. A. E. LUNDBYE ROAD PAVER 6 Sheets-Sheet 4 Filed NOV. 19, 1957 Dec. 17, 1940. A. E. LUNDBE ROAD PAVER Filed Nov. 19, 1957 6 Sheets-Sheet 5 Dec 17, 1940. A. E. LUNDBYE ROAD PAVER- e Sheets-Sheet 6 Filed Nov. 19, 1937 r QMN 6 INVENTOR mmfimw Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE 25 Claims.

This invention relates to a road paver and more particularly to a machine for laying and grading stone and asphalt mixes upon roadways and resurfacing the same or in providing an original surface or base for the road. The machine can be used for laying and grading either cold mixes of stone, asphalt and solvent or hotmixes of asphalt and aggregate.

In laying and grading asphalt and stone mixes on a roadway considerable difficulty has been encountered by reason of the fact that the stone and asphalt mix is very heavy and difiicult to handle and lay to an accurate surface. It is the principal object of this invention to provide a machine which lays and grades heavy mixes of asphalt and stone or the like; which will handle large quantities of such mixes and rapidly and accurately grade the same to provide the smooth and. uniform surface desired; and which accomplishes this without requiring any handling of the asphalt, the mix being dumped directly into the hopper of the machine from the trucks used for transporting the mix to the job.

Another object of the invention is to provide such a machine which is supported in whole or in part on the surface laid by the machine to obtain a smooth and uniformly surfaced roadway and. in which the weight of the machine is carried by a large area of supporting surface so that the machine has a minimum tendency to displace the freshly paved material. This is particularly important in laying such materials as asphalt and sand which are laid as a very soft body and which, before hardening, are easily indented. To this end the machine is supported by a pair of continuous steel belts or tracks which pass around large rollers at the rear end of the machine and under supporting rollers between these main rollers, each of these steel belts thereby providing a smooth continuous surface for supporting. the machine on an extended area of the freshly paved material.

Another object of the invention is to provide means for preventing paving material from accidentally becoming lodged on the inside of the belt and thereby being crushedbetween the belt and the rollers as the machine is propelled.

Another object is to provide a shoe at each end of each belt which provides a solid backing for the belt in the space between each large roller and the adjacent supporting roller, these shoes thereby providing a solid backing across this gap which would otherwise be unsupported.

Another object is to provide a mounting for the endless belt and roller assembly which permits the entire assembly to tip and thereby adapt itself to any crown in the strip of pavement being laid.

Another object is to provide a simple and effective adjustment for the spacing of the main rollers, this adjustment adjusting the tension of the endless steel belt and the friction between the belt and the driving roller.

Another purpose is to provide a simple means for keeping the outer surface of each endless belt free from adhering lumps of asphalt or other material and also to provide a simple and effective means for oiling the outer surface of each belt so as to reduce the tendency of the belt to pick up any material.

Another aim of the present invention is to provide a self-propelled paver having a hydraulic drive, the motor driving a hydraulic pump which is employed to propel the paver.

Another object of the invention is to provide such a hydraulic drive which includes a separate hydraulic motor for each side of the machine, the adjustment of these motors thereby permitting of steering the machine.

Another aim of the invention is to provide such a paver which includes a hopper mounted at the front end together with a raker bar in the hopper and a reciprocating cutter bar at the bottom of the hopper which cuts off the column of material in the hopper to provide a paved surface having the desired thickness and crown, both the raker bar and, the reciprocating cutter bar being driven by hydraulic motors.

Another aim of the present invention is to provide a hydraulic lift for the cutter bar assembly, this hydraulic lift permitting of readily adjusting the cutter bar to provide a paved strip of the desired thickness.

Another aim of the invention is to provide such a paver which issupported exclusively on the freshly laid surface and in which the-cutter bar can be adjustably inclined with reference to the line of movement of the paver, this adjustment being provided so that thepaver can be made to follow dips and rises in the roadway being surfaced, the cutter bar having its front end tipped downwardly when passing over a rise in the roadway and having its front end tipped upwardly when passing beyond the center of a dip in the roadway.

Another object of the invention is to provide a power operated cut-off in the bottom of the hopper for rendering all or any part of the hopper inoperative, thereby to lay a strip of any desired width or to close 011' the hopper discharge entirely when it is desired, for example, to cross an intersecting road and not do any paving. In the preferred embodiment of this cut-off the cut-off is operated hydraulically and can be adjusted to lay a strip of any desired width within close dimensions. To this. end the power cut-off consists of a plurality of narrow plates which can be coupled together in any desired number and are shifted by a hydraulic piston to a position under the hopper opening in which they operated to reduce the effective width of the hopper or close it off completely or are retracted to an inoperative position.

Another object is to provide a simple and effective edger plate for the last plate forming part of the power operated closure, the cutter bar coacting with this edger plate to provide a square shoulder at the corresponding side of the strip being laid.

Another object is to provide a combined heated shoe and brush for heating and brushing abonding material against the shoulder of a strip against which the strip is being laid. In laying roadways of substantial width it is frequently necessary to lay the roadway in a plurality of parallel contiguous strips. In order to secure a firm bond between the successive trips the present invention proposes a heater which rides along the shoulder of the strip already laid and heats this shoulder and also a bonding material applied to the shoulder so that when the paving material is paved up to and against this shoulder a firm bond is obtained.

In the accompanying drawings:

Fig. 1 is a top plan view of a. paver embodying the invention, the hydraulic piping between the different pumps and the different hydraulic motors being represented diagrammatically.

Fig. 2 is a side elevation thereof.

'Fig. 3 is a horizontal fragmentary section, taken on line 33, Fig. 2.

Fig. 4 is a similar section, taken on line 4-,

Fig. 2.

Fig. 5 is a fragmentary vertical transverse section, taken on line 5--5, Fig. 2.

Fig. 6 is a fragmentary vertical longitudinal section, taken on line 6-6, Fig. 5.

Figs. 7, 8, 9 and 10 are vertical, fragmentary transverse sections, taken on the correspondingly numbered lines on Fig. 6.

Fig. 11 is an enlarged fragmentary top plan View of the hopper at the front end of the paver.

Fig. 12 is a fragmentary vertical longitudinal section, taken on line l2-l2, Fig. 11.

Fig. 13 is a fragmentary vertical transverse section, taken on line Iii-I3, Fig. 12.

Fig. 14 is a vertical fragmentary transverse section, taken on line I l-I4, Fig. 11.

Fig. 15 is a vertical fragmentary transverse section, takenon line l5--l5, Fig. 12.

Fig. 16 is a view similar to Fig. 11 showing a modified form of means for blocking off portions of the hopper to vary its effective width.

Fig. 17 isja fragmentary vertical longitudinal section, taken on line I'I l'|, Fig. 16.

Fig. 18 is a fragmentary front elevation of the machine showing a heating shoe and brush mounted thereon, together with the heating means associated with the heating shoe', this shoe being used to condition the shoulder of a strip already laid to secure a bond between it and the strip being laid.

Fig. 19 is a vertical longitudinal section, taken on line l9-l9, Fig. 18.

Fig. 20 is a top plan view of the heating shoe and brush.

Fig. 21 is a generally horizontal section, taken on line Zl-Zl, Fig. 20.

The main frame 25 of the carriage is shown as being composed of a plurality of longitudinal channel beams suitably connected by cross channels to support the various working parts of the paver. On this frame is mounted an operators platform 26 on the rear end of which is mounted a gas engine 21 which provides the motive power for propelling the paver and operating its continuously moving parts as well as certain of the controls as hereinafter described. At its front end the carriage 25 supports a hopper 28 includ ing side walls 29 and 30, a vertical rear wall 3! and an inclined front wall 32, this front wall 32 being supported by suitable angles 33, 34 and 35 connecting the side walls 29 and 3B. The materials are dumped into this hopper and pass out through the opening 36 in the bottom thereof, this material being leveled to a predetermined height and crown, as hereinafter described, as the paver travels along. The paver is shown as supported exclusively on the freshly laid surface formed as the material passes out of the hopper and in order to support the paver on a broad area and thereby minimize any tendency of the paver to sink into the freshly laid material, the paver is supported at its opposite sides by an endless steel tread or belt, the lower stretch of which rides on the freshly laid pavement and provides a. broad bearing support for the entire machine. The supporting or tractor structures at the opposite sides of the machine are identical in construction and operation and hence a description of one will be deemed to apply to both.

The numeral 40 represents an endless steel belt or track, this belt passing around a driving roll 4| at the rear of the machine and a front roll 42 at the front of the machine. The endless steel belt or track 40 is preferably made of a band of saw steel, the ends being welded to form an endless track, this track forming, of course, a smooth continuous traction surface.

The rear driving roll 4 l as best shown in Fig. 5, is fast to an axle 43, the opposite ends of which are journaled in the depending legs of a U-shaped bracket 44. This bracket is connected at its inner upper corner by a pivot pin 45 to a stationary bracket 46, this stationary bracket being suitably secured to one of the longitudinal channel beams constituting the main frame 25 of the carriage. A vertical rod 41 is pivotally connected to the outer upper corner of the bracket 44 and extends downwardly through the adjacent outermost longitudinal channel of the paver, a compression spring 48 being interposed between the bottom of this channel and a pair of nuts 49 at the bottom of the rod 41. The front roll 42 is mounted in a somewhat similar manner, this front roll being rotatably mounted on a stationary axle 55, this axle being carried at its opposite ends in a pair of blocks 56, 56, each of which is slidably mounted in one of the depending arms of a U-shaped bracket 51. The blocks 56, 56 are slidable lengthwise of the paver for the purpose of adjusting the tension of the steel belt or track 40 as hereinafter described. The inner upper corner of the U- shaped bracket 5'! is connected by a pivot pin 58 with a bracket 59, this bracket being suitably secured to the main frame of the machine and the opposite corner of the bracket 5'! being supported by a rod 60 pivotally connected thereto, this rod extending downwardly through the outermost channel of the frame and being supported by a compression spring 6| interposed between the bottom of'this channel and a pair of nuts62 at the-lower end of the rod 60. I I

It will be seen that this mounting for the rolls 4I,'42 permits the tractor assembly at each side of the paver to move about an axis extending longitudinally of the paver and thereby tip slightly and adapt itself to any crown in the strip being laid. I

In order to render the lower stretch of the steel belt 40- completely effective as a bearing surface throughout its length, this stretch is backed by a plurality of small rollers 65 under which the steel belt 40 passes, as best shown in Fig. 6, these rollers being provided in a row extending from the large front roll 42 to the rear driving roll 4|. Each of these rollers 65, as best shown in Fig. 8, are rotatably mounted on a supportingv pin legs of the bracket 57 supporting the front roll '42, as best shown in Fig. 10. It will therefore be seen that the mounting for the small rollers 65 is rigid with the mountings for the front and rear main rolls 42, 4| and that the small rollers 65 thereby provide an antifriction backing support for the lower stretch of the belt 40. Paving material is prevented from falling between the plates 6'! and hence onto the rollers 66 and the inside of each belt 40 by a top plate 69 connecting each pair of angle bars 68 and extending from the front roll to the rear roll as best shown in Fig. 6.

It is, of course, highly undesirable for pieces of road paving material to fall over the edge of the belt to a position where they would be crushed between the belt 40 and the rolls 4|, 42 and the rollers 65. To prevent this a felt seal is provided at each side of each tractor assembly between each side plate 6'! and the adjacent edge of the steel belt 40, this felt seal extending into the front and rear rolls 4| and 42 so as to completely prevent stone or asphalt from running over the edge of the belt and, of course, that part of the belt traversed by the rollers 65. For this purpose an angle bar 10 is secured along the lower edge of each of the side plates 61, the lower flange of each of these angle bars 10 extending to a point adjacent the corresponding faces of the rollers 85. Each of these angle bars, as best shown in Fig. 7, has welded thereto a pair of depending metal strips H which form a longitudinal downwardly facing channel 12. In this channel is arranged a felt strip 13 which is backed by a small metal strip 14. The felt strip 13 is pressed against the upper face of the lower stretch of the steel belt 40-by a plurality of small compression springs 15 arranged alongside the upper or inner part of the channel and bearing downwardly against the metal strip 14. The front end of each of the felt strips 13, as best shown in Fig. 3, terminates adjacent the side of a shoe 80. At each side of this shoe 80 a felt strip 8| is mounted thereon, the felt strip 8| forming a continuation of the felt strips 13 and the front ends of the felt strips 8| entering grooves 82 provided in the periphery and near the edge of the front roll 42. Preferably an additional seal 83 is provided across the joint of each of the felt strips 13 and 8|. Each of the shoes 80 is supported, and its felt strip 8| held yieldingly in engagement with the upper surface of the steel band 40 by springs 84 which bear downwardly against arms 85 projecting outwardly from opposite sides of each shoe 80. The upperends of each of the springs 84 bear against the arm'Bl of a bracket 81, the brackets 81 being secured to the stationary front axles 55, as best shown in Fig. 10.

A similar shoe 90 is arranged under the rear roll 4| and carries a pair of felt strips 9| which project into peripheral grooves 92 provided at the opposite sides of the rear roll 4|. The felt strips 9| form a continuation of the long strips 13 and are held in sealing engagement with the steel band 40 by compression springs 93 which are .interposed between ears 94 mounted on the It will be seen that the felt strips 13, 8| and 9| completely fill the space between each plate 61 and the adjacent edge of the steel band 40 and that these strips extend from the front roll 42 to the rear roll 4| and into grooves provided in these rolls so that no stone or paving material can roll over the edge of the steel band 40 and be crushed between the band and the rollers 65 or the main rolls 4|, 42. It will further be noted that the shouldersof each roll 4| and 42 are beveled, as indicated at 96, the bevels 96 removing any road paving material which becomes lodged on the extreme edges of the lower stretch 'of the steel band 40.

In order to keep the traction surface of the steel band free from material a scraper I00 is mounted "the outer surface of the steel band 40.

Each of the castings 81 is also preferably provided with the rearwardly extending arm I03, these arms carrying spring loaded scrapers I04 which engage and scrape the surface of the front roll 42, the purpose of the scrapers I04 being to remove any material which accidentally gets on the inside of the belt 40 and is transferred to the front roll 42. Similarly each of the rear rolls is preferably scraped by spring loaded scrapers III) which are suitably mounted on the top plate 69 at each side of the paver in any suitable manner. The scrapings from the scrapers I04 and H0 fall upon the top plates 69, as best shown in Fig. 6, from which they can be conveniently removed.

In order to reduce the tendency of the steel band 40 to pick up road paving material it is preferably oiled. For this purpose an oil tank I05 is provided having discharge pipes I06 which distribute oil over the upper stretch of each steel 'belt 40under control of a valve I0'I. This oil is spread over the surface of each steel band 40 by a spring loaded felt pad I08 carried by an arm I09 which is mounted on and projects rearwardly from the corresponding U-shaped bracket 51, as best shown in Fig. 6.

Means are also provided for adjusting the tenvice, indicated generally at II5, as best shown in side plates 61 and arms 95 projecting out from "the opposite sides of each shoe 90.

which connects the links H1 and I20.

Fig. 4. Each of these adjusting devices includes a pair of links H6 and I I1 pivotally connected to one another and to the main frame 25 as indicatedat H8, and a second pair of links II9, I20 pivotally connected to one another and to a rod I2I which is guided for movement lengthwise of the machine by a bearing bracket I22. The ends of the links H6 and H9 are connected by a link I23 and a screw I24 extends through the link I23 and threadingly engages a link I25 An adjusting wheel I26 is secured to the end of each of the screws I24 and bears against the link I23 so that upon turning the hand wheel I26 in the proper direction the links I23 and I24 are brought together and the rod I2I moved toward the front end of the paver. The front end of each of the rods I2I is connected by a compression spring I21 with the adjacent sliding block 56 and it will therefore be seen that by adjusting the hand wheels I26 the tension of the steel belt can be regulated.

The paver is hydraulically propelled by a pair of hydraulic motors I30, each of which drives a chain I3I passing around a large sprocket I32 keyed to the end of the corresponding rear axle 43. Fluid under pressure is supplied to each of these motors by a pump I34 which is driven by the gas engine 21, as best illustrated in Fig. 1. The outlet line I35 of each of the pumps I34 connects with a manually adjustable valve I36 which can be set to deliver any desired amount of the fluid to the motor I30 either through a line I31 or a line I38. If the fluid is supplied through the line I31, the line I38 serves as a return line, the return fluid passing through the valve I36 and through a line I39 to a common discharge I40. This common discharge leads to a fluid supply tank I4I from which the fluid is Withdrawn through a manifold I42 which supplies all of the hydraulic pumps driven by the motor 21. It will be seen that each valve I36 can be adjusted to deliver fluid to the corresponding motor I30 in either direction thereby rendering the paver capable of being propelled either forwardly or backwardly. It will also be seen that by the relative adjustment of the two valves I36 the paver can be steered since driving one of the steel belts 49 faster than the other will necessarily turn the paver in a corresponding direction.

The trucks supplying the paving material to the machine are backed up against the hopper 28 with the rear wheels of the truck against rollers I45 each of which is rotatably mounted on a shaft I46 carried by brackets I41, these brackets being mounted on an I-beam I48 which extends across the machine immediately below the front hopper wall 32. The I-beam I48 can be secured at its ends tothe side walls 29 and 30 of the hopper in any suitable manner. As the paver is propelled along it slowly pushes the truck ahead thereby permitting of gradually dumping the road paving material into the hopper as the paving operation proceeds. The material in the hopper is broken up and distributed by the blades I50 of a raker bar I5I, the ends of this raker bar being journaled in the side Walls 29 and 30 of the hopper in any suitable manner. Preferably the raker bar is square in cross section and the blades I50 are of L-shaped form and connected to the square sides of the raker bar by bolts I52 so that the pitch of the blades I50 can be adjusted to obtain any desired spreading or distributing effect, depending upon the type of material being laid. Theraker bar is driven by a sprocket I55 and a chain I56, these being arranged in a suitable housing I51 and the chain being driven by a sprocket I58 mounted on the jack shaft I59. This jack shaft I59 is driven by a hydraulic motor I60 through a chain and sprocket drive I6I. 5

Fluid for driving the hydraulic motor I60 is supplied by a pump I62 driven by the motor 21. The outlet line I63 from the pump I62 connects with a valve I64 having a handle I65 which can be moved to deliver fluid through a line I66 to 10 the hydraulic motor I60 and thereby operate the rotary raker bar I5I. The return line I61 from the motor I60 leads to the common return I40.

As the paver moves along the column of material contained within the hopper 28 is out off 15 at a predetermined height by a reciprocating cutter bar assembly indicated generally at I10. This cutter bar assembly includes a toothed cutter bar which is reciprocated transversely of the paver to smoothly cut off the paving material to .20 the desired grade; the cutter bar assembly is vertically adjustable to provide a strip of pavement of the desired thickness; the assembly is also capable of being adjustably tilted to follow the long undulations of the road and lay a strip of uni- 25 form depthand the cutter bar is also capable of being crowned so as to lay a strip having any desirable crown.

To this end the cutter bar assembly includes an angle bar I'II which extends the full width 30 of the machine and is located immediately in rear of the rear hopper wall 3!. Each end of the main supporting bar I1I is supported by a piston rod I12 whichis pivotally connected to the corresponding end of the bar I1I in any suitable .95 manner; Each piston rod I12 forms part of a hydraulic lifting jack I13. These hydraulic lifting jacks are independently supplied with fluid under pressure delivered by a pump I14 which is driven by the gas engine 21. To this end, the 40 outlet I15 of this pump I14 connects with a valve I15 having a handle I11 which can be set to deliver any desired amount of fluid through either an outletline I18 connecting with one end of one of the jacks I13 or a line I19 connecting with 45 the other end of this jack I13. Similarly, the pump outlet line I15 also connects with a valve I16a having a handle I11a which can be set to deliver any desired amount of fluid through either an outlet line I18a connecting with the 50 other jack I13 or a line I19a connecting with the other end of this last jack. The valve I16 is so constructed that in one position it connects the pressure line I15 with, say, the line I19 and at the same time connects the other line I18 with a 55 line I89 leading to the common return line I40. Similarly, the valve I16a is so constructed that in one position it connects the pressure line I15 with, say, the line I190. and at the same time connects the otherline I18a with the line I89 60 leading to the common return line I40. It Will therefore be seen that by adjusting the handles I11 and Illa fluid can be admitted to either or both the jacks I13 to positively either raise or lower either or both ends of the cutter bar as- .65 sembly of which the cross bar I1I forms the main supporting member.

The bar I1I carries a track I80 which is so mounted as to be adjustably crownable. For this purpose, as best shown in Fig. 13, a cam or ec- 70 centric shaft IBI is mounted on the supportin bar HI and on this shaft are mounted a plurality of eccentrics I82 in spaced relation therealong. This shaft is adjustably rotated by turning a I hand wheel I63 fixedly mounted on the upper end of a rotatable post I84, the lower end of this post being operatively connected with the cam shaft I8I by a worm and worm gear drive I85. Each cam I82 is embraced by a yoke I36 fixed to the upper end of a post I81. These posts extend through openings provided in the horizontal flange of the angle bar I'II and at its lower end each is fixed to the curvable track I80. The opposite ends of the track I80 are suitably supported by brackets I88 at the opposite ends of the angle bar I1 I. The cams I82 are so set that by manually adjusting the cam shaft I8I the posts I81 are moved to crown the track I80 to a greater or less degree as may be desired. I

The cutter bar, as best shown in Figs. 12 and 13, includes a channel bar I99 which is arranged with its flanges projecting upwardly directly under the track I90. At intervals the flanges of the channel I90 are notched as indicated at I9I to secure greater flexibility of the channel in following the curvature of the track I80. At spaced intervals brackets I92 are mounted on and project upwardly from the channel I90, these brackets carrying a pair of rollers I93, I94 which ride on the upper and lower surfaces of the track The cutting of the material is effected by a plurality of plates I95 which are replaceably secured to the underside of the channel I90 and the channel I90. It will be seen that the rollers I96 hold the channel I90 against rearward displacement' and at the same time permit this channel to be reciprocated back and forth. In order to permit a large amount of vertical adjustment of the cutter assembly by the jacks I13 the rear wall 3I of the hopper terminates a substantial distance short of the ground and a plate 230 is secured at its upper edge to the upper edge of the main supporting angle bar I1I of the cutter bar assembly. This plate 200 extends forwardly into engagement with the rear face of the rear wall'3I of the hopper and turns down- .wardly to a point below the uppered'ge of the 'channel bar I90. It will therefore be seen that this plate 200 tends to prevent the material from flowing over the top of the channel bar and at the same time moves up and down with the cutter bar assembly The plate 200 is shown as having welded to its lower front face a plurality of spaced forwardly projecting plates 20I, the purpose of these plates being to in part support the load of the material within the hopper and also to insure that no large sized lumps of material or rocks strike the teeth of the cutter bar. Since the plate 299 is mounted on a non-reciprocating part of the cutter bar assembly the plates 20I remain stationary. In order to permit of a high lift of the entire cutter bar assembly each plate 20I is formed to provide a slot 202 between its upper part and the plate 200, the rear wall 3I of the hopper entering these slots 202 as the cutter bar assembly is raised. The plates 20I also function in conjunction with the power cutoff, as hereinafter described, to relieve the'power cutoff of a part of the load.

Additional means are also preferably provided to prevent paving material from flowing over onto the cutter bar assembly. To this end a plurality of vertical, upstanding plates 293 are weldedto the front face of the channel bar I00, as best shown in Fig. 12, and extend upwardly along the back of the plate 200 in closely spaced relation thereto. The plates 203 are spaced the entire width of the hopper and the spaces between these plates are coincident with the notches I9I pro- :1

vided in the flanges of the channel bar I90, as best shown in Fig. 13, so as not to. interfere with the flexing of the channel bar I90 in laying a crowned roadway. As an additional precaution a plate 204 is welded to the upper faces of the 2 forwardly projecting teeth I95 in advance of each .plate 203 and in advance of the cross plate 200, as best shown in Fig. 12. It will therefore be seen end heads of the motor and is connected at each end with a bracket 201, these brackets being secured to the sides of the channel bar I90, as best shown in Fig. 13. The fluid for operating the motor 205 is supplied from the pump I14 through line I15 and is delivered, under control of a valve handle 208, to a line 209 connected by a flexible tube 2I0 to the motor 205. The fluid from the motor is returned through a flexible conduit 2II to a line 2I2 leading to the common return line I I40. The reciprocation of the piston rod 206.can'

be effected by any suitable manner as by the provision of a valve rod 2I3 which admits the fluid alternately to opposite sides of the piston. and is shifted by an arm 2I4 carried by one of the brackets 206.

Since the paver is supported exclusively on a strip of pavement already laid it will be appreciated that it is necessary for the operator to adjust the position of the cutter bar when going up and down grades. Otherwise, when once start- 1 ed on an upgrade, the paver would tend to continue going onan upgrade when, for example, reaching the top of a rise in the road. To permit of readily adjusting the cutter bar to follow the course of the subgrade or road being paved and lay a strip of uniform thickness, means are provided at each side of the paver for tilting the cutter bar assembly which means are preferably constructed as follows:

Mounted at each end of the main angle bar I1I of the cutter bar assembly is a bracket 2| 5 to the upper and lower ends of which are pivotally connected a pair of links 2I6 which extend forwardly in parallel relation. These links are of the same length and at their forward ends are' pivotally connected to a lever 2I1. This lever is pivotally connected by means of a bracket 2I8 to the corresponding side wall of the hopper, the pivotal connection between each lever 2I1 and the bracket 2 I8 being halfway between the pivotal connections between the lever 2I1 and the links 2I6. It will be seen that the parallel links 2 I6 permit of the vertical adjustment of the cuthopper opening 36. .cross 'bar 235 which is provided-with openings 236 or backwardly the cutter bar assembly is tilted correspondingly. The means for so tilting each lever 2I'I comprise a rod 2 I9 which has threaded engagement with a sleeve 22!] which is pivotally connected to the extreme upper end of the lever 2I'l. The rod2l9 is suitably journalled at its rear end on the main frame and is operatively connected to the vertical post 22I by means of a pair of bevel gears. The post 22l is turned by means of a hand whee1222. It will be understood that'instead of having separate hand wheels 222 at the opposite sides of the paver, only one such hand wheel could be provided to simultaneously adjust the levers 2| I at opposite sides of the machine.

In the form of the invention shown in Figs. 1-15, a power cutoff -isprovided by means of which the effective widthof the hopper can be reduced to any desired degree. The power cutoff is actuated by a piston within each of a plu- 'rality of cylinders 223, each of these pistons actuating a piston rod 224. These power cutoff *pistons are double acting, the front ends of the cylinders being supplied with and relieved of fluid under pressure through a common pipe .225 and the rear ends of the cylinders'being supplied with-and relieved of pressure through a common pipe 226. 'The pipes 225 and 226 connect with the valve I64 and the operation of the pistons is controlled by'a valve handle 22'! which can be operated toadmit fluid under pressure from the line I62 to either the pipe'225 or the pipe 226, that pipe which is not so connected with the supply line I62 being connected with a return line 228 which discharges into the common return line I40.

adjacentthe rear edge of the inclined front wall 32 of the hopper and'its piston rod 224 is pivotally connected, as indicated at 232, to-a pair of "ears 233 fast to the underside of the front end ofasliding plate 234. Each of these plates 234 is retractible from a position'in which its rear edge is arranged adjacent thelower end of the rear hopper wall 3| to a position in which its rear-edge is arranged adjacent the loweredge of the front hopper wall 32 whereby the plates 234 serve asa-part of the means for blockingofl the The plates 234 slide upon a for the piston rods HI and the rear end of each of theplates- 234 is held downby engagement with a channel 231 whichextends from one side of the hopper tothe other under the front hopper Eachof :the plates 234 is bent downwardly at its rear endas indicated at-238 so as to form a flange to which a series of cutoff plates can'be connected in tandem so as to move with the plates 234. Any number of these plates can be so.connectedtherebyto adjust the eifective width .of the hopper. vAs best shown in Figs. .11, 1.4 and 15 eachof these plates 240 is in the form of a long narrow strip arranged parallel with the plates234 and to each is welded an upper plate 24I anid-a lower plate 242,-these plates extending beyond one edge of the plates 240 so as to form 113 and that by tilting the lever 2I'l forwardly -a groove 243. The rear end of each of the plates 24!! is bent downwardly to form a flange 244 and the plates are arranged in series each plate 234 having one edge fitting into the groove 243 of the next plate 240 and this plate 240 having its edge fitting into the groove'of the next succeeding plate 240 and so on.

To couple the plates 234 and 243 the rear flange of the plate 234 is provided with a hole receiving a bolt 245, this bolt also extending through a tie: bar' 246 riveted to the rear flange 244 of the adjacent plate 240. Each of the plates 243 is provided with a tie bar 246 which is adapted to be attached to the next preceding plate 240 by means of a bolt. It will be seen that by this arrangement any number of plates 24!! can be tied to its plate 234 and that this can be readily accomplished while the cutoff is in a partly retracted position, at which time the tie bars 246 are .readily accessible from the front end of the paver.

Each of the plates 246 has a pair of holes 253. These holes are so positioned as to be covered by the plates MI and 242 in the assembled condition of the plates 240 and therefore only the holes 259 of the last plate 240 of each series is exposed. These holes are employed for securing anedger plate I at the end of the hopper opening. For this purpose, as best shown in Fig, 14,

the edger plate 25I is provided at its upper edge with a flange 252 which is bolted through the holes 250 by bolts 253. The lower edge of this edger plate, as best shown in Figs. 12 and 14, carries a pair of rearwardly projecting bars 254 which project under the cutter bar I96. These bars 254 serve to mold a square shoulder at the corresponding edge of the strip being laid, the cutter bar reciprocating in close proximity to the upper edges of these bars. If desired the edger plate 25I may be additionally strengthened by the provision of an angle 255 which can be secured by means of a bolt 256 in one of the series of holes provided in the cross bar 235. The front end of each of the plates 240 is also slotted as indicated at 251 so as to clear the plates ZDI and completely close off the hopper.

In the modified form of the invention shown in Figs. 16 and 17 a different form of means for blocking oif variable amounts of the hopper is shown. The hopper is of substantially the same construction as that disclosed in Figs. 1-15 and the same reference numerals have therefore been employed and distinguished by the sufiix a. As shown in Figs. 16 and 17 the front wall 32a of the hopper is provided with a series of holes 266 nearits lower edge and the rear wall 3Ia. of the hopper is provided with a series of corresponding holes 26 I. The hopper. is blocked off by a pair of telescopic plates 262 and 263, the plate 2-63'sliding under the plate 262, as best shown in Fig. 16, and forming an extension thereof. Each of the plates 262 and 263 is trough shaped and its front edge is secured through the holes 260 to the front wall 32a of the hopper by means of bolts 264. The rear edge of the plates 262 and 263 is secured through the holes 26I to the rear wall 3Ia of the hopper by bolts 265. It will be seen that by this construction the plates 262 and 263 can be made of comparatively light material so that the bolts 264 and 265 draw the edges of the trough shaped blocking off plates tightly into engagement with the respective hopper walls. Further it will be seen that by removing the bolts the plate 263 can be moved along the hopper to provide any desired width The compression spring 291 is interposed beof hopperopening. The holes 268 and 26| can, of course, be provided in any spacing to vary the degree of adjustability. The end plate 263 is also preferably provided with an edger plate 286 generally similar. to the edger plate I in the preferred construction, this plate and its extensions 261 serving to mold a square corner at the edge of the strip.

In laying a series of parallel strips of pavement it is, of courseQhighly desirable to secure a 'firm bond between the edges of the successive strips. It has been found that this bond can be improved by heating the edge of the strip already laid just before the succeeding strip is laid against it and at the same time applying to this edge a coating of hot asphalt. To this end the paver can be equipped with a heating shoe and brush applying device shown in Figs. 18-20. As there shown the I-beam I48 supports a generally vertical plate 218 which extends from one hopper wall 29 to the opposite hopper wall 38.

Near the center of this plate 218 is mounted a small tank 21I which is adapted to be filled with asphalt and a chamber 212 is provided on the underside of this tank 21I through which the flame of a blow torch 213 is projected. The ex.- haust line from the chamber 212 includes a flexible tube 214, the other end of which connects and discharges into a shoe 215. This shoe is provided with a flat bottom or ironing face 216 which merges into rounding ends and side walls, the side opposite the ironing face 216 being open. The gases'from the flexible conduit 214 are discharged into the shoe at the front end thereof and are directed by the rounding front wall against the ironing face 216, these gases escaping through the opening back of the shoe. The

shoe is connected by a generally vertical pivot pin 288 with a fitting 28l which carries a horizontal stud 282. This fitting is supported by ears 283 at the lower end of a post 284. The stud 282 projects through the ears 283 and a nut 285 is provided which clamps the fitting 28I in fixed relation to the post 284 so that the ironing face 216 of the shoe 215 is held at a fixed angle which can, however, be changed by loosening the nut 285. The post 284 is carried by the ends of two horizontally extending arms of a yoke 286, the post 284 being vertically movable relative to the yoke 286 but being held against turning by a key 281. The downward limit of movement of the post 284 with reference to the yoke 286 is limited by a pin 288 which can be inserted in one of a plurality of holes 289 thereby to adjust the elevation of the shoe 215. The post 284 and shoe 215 are yieldingly held in the extreme downward position permitted by the pin 288 by a compression spring 298 interposed between the upper arm of the yoke 286 and a washer 29I, this washer being in turn supported by a pin 292 in one of the holes 289.

The yoke 286 iscarried by a stud 295. fixed to and projecting outwardly from a bracket 296 The stud 295 is horizontally disposed and the bracket 286 is free to rotate thereon so that the shoe 215 is free to move toward and away from the center of the machine and thereby adapt itself to irregularities in the shoulder of the strip which it heats and irons. The shoe 215 is yieldingly held against this shoulder by a compression spring 291 which surrounds a rod 298. This rod is secured at one end to an ear 299 which projects rearwardly from the bracket 298 and extends through an opening provided in an ear 388 projecting upwardly from the bracket 296.

tween the ear 388 and a nut 38I at the end of the rod 298, this nut adjusting the tension of the spring 296 and thereby the pressure at which the shoe 215 is held against the shoulder of the strip already laid.

The shoe 215 is followed by a brush 385 which applies hot asphalt from the tank 21I to the heated and ironed shoulder of the strip already laid. This brush includes bristles 386 mounted in a hollow brush back 381, this back 381 having arms 388 each of which is pivotally connected to the shoe 215 as indicated at 288 so that the brush 385 is movable toward and from the shoulder of the strip already laid independently of the shoe vby a flexible line 3 under control of a valve 3I2. This flexible line 3 discharges into a pipe 3| 3 which extends through the brush 385 and distributes the hot asphalt among the bristles 386 for application to the shoulder of the strip already laid.

Operation In laying a road with the paver the operator starts the motor 21, this motor driving the pumps I82, I14 and I34 for propelling the machine and operating the different hydraulic mechanisms. If the strip to be laid is less than the total width of the hopper, the operator then couples as many of the plates 248 to the plate or plates 234 as may be required to reduce the effective width of the hopper. He does this by securing the tie plates 246 of as many plates 248 as may be needed, in tandem, to the plate or plates 234. This compels the corresponding plates 248 to slide in unison with the plate 234. If only a small part of the paver is to be blocked off only one of the plates 234 is employed and a suitable number of the plates 248 secured in tandem to it. Under these circumstances the valves 226 controlling the operation of the other three cylinders 223 are closed so as to render all of the other plates 234 inoperative. If, however, a greater amount of the hopper is to be blocked off than that controlled by one plate 234, one or more of the other cylinders 223 are rendered operative by opening the corresponding valve or valves 229. Thereafter the operator turns the valve handle 221 to admit fluid from the pump I26 to the line 225. This conducts fluid under pressure to the operative cylinders 223 and moves the corresponding piston rod or rods 224 rearwardly. This thereby shifts the corresponding plate or plates 234 rearwardly carrying along the corresponding attached blocking ofi plates 248. At the extreme stroke of .the pistons these plates are all disposed across the bottom opening of the hopper and supported by the cross bars 235 and 231. The operator then attaches the blocking off plate 25I to the endmost of the plates 234 by means of the bolts 253 which pass through the upper flange of the blocking off plate 25I and through the holes 258 of the last plate 248. This edger plate 25I serves to mold a square corner at the corresponding side of the comparatively narrow strip being laid, its extensions 254 extending under the cutter bar.

The operator then turns the post I84 to obtain the desired crown in the strip of pavement being laid. Turning this post, as shown in Fig. 13, turns the icam shaft IBI therebyrotating the cams I82 'which-areso'disposed as to crown the track 1819 to a greater or less degree as the camshaft IBi :is rotated, these cams-being 'operatively connected with the track :by'means of the yokes I86 at the upper ends of the posts 187. The'crown- :ingof the track effects a similar crowning of the channel I90 which reciprocates along this track andhence effects a corresponding crown in the strip'of pavement being la-idrsince the teeth 495 which cut off the column of material falling through the hopper to a predetermined height are mounted directly'on the underside of this channellilll. Theoperator then turns'thevalve'handle I-"I'l and-I'lla to-el'evate or'depress either-or .bothendsofthe'cutter bar-assembly to provide the'desired thickness in either side of the strip being laid. The turning of this handle I'I'I admits fluid under pressurerfrom the pump I'M to either the line I'I8 orthe line I19, this being under-controlof the operator throughthehandle All. This admits fluid to the upper or-lower end o'f-the hydraulic jack I13 at therrighthand side of the'paver and therefore either-raises or lowers thelinks I12 at thesame side of the -machine accordingly. Similarly the manipulation of the valve handle Illa admits fluid to either the line I'I8a. or Ilsa and operates the jack I13 at the lefthand side of thepaver. The links IIZ-support the opposite. ends of the main'bar l 'II of the cutter'bar assembly and it will therefore be seen thatthis manipulation of the valve handles IT! and -I 'I'Ia adjuststthe elevation of the opposite ends of the cutter bar I90 as may be desired.

The operator then throws the valve handle I65 to start the rotaryraker bar II. Opening the valve controlled by the handle I65 admits fluid from the pump -I62 through the line I 63 and thence through the line-IE6 to-the hydraulic motor '00, the spent fluid being returned through the line I01 to'the common return I40. The motor lfit, as best-shown in Fig. 2, is connected by a pair of-chain-drives I BI and I56 with'the rotary'raker-bar .I:5I and hence rotates this bar. .Theoperatorthen throws the valve handle 208 to vstart'the reciprocation of the cutter bar. Throwingthis handle'admits fluid from the pump I14 .throughthe line I15 to the line 209 connected by means of the flexible conduit 2I0 with'the motor 205 which reciprocates the raker bar I90, the spent fluidbeing returned through the flexible conduit 2H and line ..2I2 to the common return Hi0. As the pistonrod 206 of thecutter harmotor moves the angle bar I 90 to one extreme of its movement theflngerZM shifts the valve=2I3 so as to cause the motor 205 to move the piston rod 205 back to its other extreme position, the valve 2I3 thereby serving to secure uniform reciprocation of the, cutter bar I90 which carries the cutting teeth I95.

A truck load of. pavingmaterial is then brought up to the paver and dumped into the hopper. This material is broken up and distributed by the rotary raker bar and forms a column supported by the roadway. The operator then opens the valves I35 .to propel .the paverforwardly. Gpen- .ing the valves I30 admits fluid from the tractor pumps I34 through the lines I35 and I3! to both of the hydraulic motors I30, the spentfluid being returned through the lines I38, valves I 30 and lines I39 to the commonreturn I 40. Adjusting the valves I35 to deliver different amounts of fluid permits of steering the mechanism and reversing these valves effects a reverse movement of the paver. The hydraulic motors I30, through the otherwise be the case.

thento be followed, the operator adjusts the hand :backinto parallelism simple adjustment of the hand wheels 222 perchains I3I, drive the rear rolls II at the opposite sides of the machine. The steel belts -40 pass tightly around these rolls and the corresponding front rolls 42 and hence these steel belts are advanced and the paver'propelled forwardly. As .the paver moves forwardly the teeth I95 of the cutter bar I00 cutofi the base of the column of paving material contained within the'hopper and the steel belts-40 ride up on this material. After the required thickness'of-material is being de- -2I9 and tilt-the lever 2-I'I rearwardly. This tilts the entire cutter'barassembly I so that the teeth I95 toeup. .This adjustment causes the cutting line tofollow up-the-grade and hence continue the laying of a-strip of-uniform'thickness instead of cutting into the sub-grade as would Assuming a long rise is wheels 222 so as .to bring the cutting teeth I95 of the .cutter'bar assembly back into parallelism with the roadway. Assuming that thenthe crest of .the rise is reached, theoperator adjusts the hand wheels 222 .so.as-to cause .the teeth I95 of the cutter-bar assembly to toe downwardly. This adjustment causes the paver to follow over the crest after which the teeth .I95 .can be brought .It will be seen that the mits of applying a 'layer of paving material of uniform thickness over dips and rises in the road beinglaid without disturbing the general adjustment of the height of .thecutter bar assembly.

As the pavermoves along it is supported not merely by theffront and rear rolls-M, 42 but also by the intermediate stretches of the steel belts 40, each of these intermediate stretches being backed by the rollers 65 which in turn support a structure connected and supporting the -main axles of the, machine. 'Further, material is prevented from falling over on top of the lower stretch of each belt 40 by the felt seal which extends the full length of each sideof each roller stretch of the belts 40 and enters the grooves 82 .and 92 provided in the front and rear rolls. This edges of the main rolls 4| and 42 are beveled so that any material falling overon the extreme edge of eitherbelt is forced out by the beveled edges of the rollers.

In order to prevent the belts 40 from picking up material, oil is sprayed thereon from the pipe I06, as best illustrated in Fig. 6, this .011 being distributed by the felt pad I08. Further, the exterior of this belt is scraped by the scrapers I00 and I02 which remove any material which does adhere. By makingthe treads in the form of endless steel belts theyare readily kept clean and are supported on a broad area .of.the freshly laid pavement so that the paver can be used in laying very soft material into which a paver without a broad supporting area would sink and leave track marks in theflnished surface.

From the foregoing it isapparent that the 'present invention-provides a paver which is'very simple in construction, considering the function which it performs, which is easily adjustable in opening and grading means for supporting said its operation from the operator's platform, particularly by the provision of the various hydraulic adjustments, which is supported exclusively on the finished surface thereby assuring that. the strip of pavement laid is smoothly and uniformly surfaced and not responsive to irregularities in the sub-grade and which at the same time is readily manoeuvered so as to lay a strip of uniform thickness.

I claim as my invention:

1. In a road paver of the character described, a carriage, a hopper at the front end of said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening and means in rear of said hopper opening and grading means for supporting the entire weight of said carriage exclusively on the freshly laid strip of paving material.

2. In a road paver of the character described, a carriage, a hopper at the front end of said car'- riage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening, means for adjustably raising and lowering said grading means, means for reciprocating said grading means transversely of the line of movement of said carriage and means in rear of said hopper opening and grading means for supporting the entire weight of said carriage exclusively on the freshly laid strip of paving material.

3. In a road paver of the character described, a carriage, a hopper at the front end of said carriage and having an opening inits bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening and means in rear of said hopper opening and grading means for supporting the entire weight of said carriage exclusively on the freshly laid strip of paving material comprising a front roll and a rear roll, an endless tread passing around said rolls and means for driving one of said rolls.

4. In a road paver of the character described, a carriage, a hopper at the front end ofsaid carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening and grading means in rear of said hopper opening and grading means for supporting said carriage on the freshly laid strip of paving material comprising a tractor assembly at each side of the carriage consisting of a front roll, a rear roll and an endless tread passing around said rolls, means pivotally connecting at least one of said tractor assemblies to said carriage and permitting said tractor assembly to tilt about a horizontal axis extending in the direction of movement of the carriage, and spring means yieldingly resisting the said tilting movement of carriage on the freshly laid strip of paving material, comprising a tractor assembly at each side of the carriage consisting of a front roll, a rear roll and an endless tread passing around said rolls, means pivotally connecting at least one of said tractor assemblies to said carriage and persisting the said tilting movement of said tractor assembly, said tilting movement permitting said tractor assembly to adapt itself to any crown formed in the strip being laid and means for adjusting the effective pressure exerted by said spring means.

6. In a road paver of the character described, a carriage, a hopper mounted at the front end of said carriage and having an opening in its bot tom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening, means for adjustably varying the crown of said grading means to provide a corresponding crown in the strip being laid and means in rear of said hopper opening and grading means for supporting said carriage on the freshly laid strip of paving material comprising a tractor assembly at each side of said carriage consisting of front and rear brackets, an axle supporting each of said brackets, a roll carried by each of said axles and an endless tread passing around said rolls, the said brackets of atleast one of said tractor assemblies being pivotally connected at one side to said carriage to tilt about a common axis extending along the line of movement of said carriageand a spring connecting the opposite side of each of said brackets with said carriage to permit said tractor assembly to tilt and adapt itself to the crown being provided in the strip of paving material being laid.

7. In a road paver of the character described, a carriage, a hopper mounted at the front end of said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening, means for adjustably varying the crown of said grading means to provide a corresponding crown in the strip being laid and means in rear of said hopper opening and grading means for supporting said carriage on the freshly laid strip of paving material comprising a tractor assembly at each side of said carriage consisting of front and rear brackets, an axle supporting each of said brackets, a roll carried by each of said axles and an endless tread passing around said rolls, the said brackets of at least one of said tractor assemblies being pivotally connected at one side to said carriage to tilt Y about a common axis extending along the line of movement of said carriage and a spring connecting the opposite side of each of said brackets with said carriage to permit said tractor assembly to tilt and adapt itself to the crown being provided in the strip of paving material being laid and each of said tractor assemblies also including a bar connecting its front and rear brackets and a plurality of spaced rollers mounted on said bar and'engaging the upper face'of the lower stretch of said tread and forming a backing therefor.

, 8. In a road paver of the character described,

a carriage, a hopper at the front end of said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage 'an endless integral smooth steel bel-t passing around said rolls and means for driving one of said rolls, each of said rolls having the extremities of its periphery beveled thereby to repel paving material accidentally lodging on the edges of the lower stretch of said belt and passing between said belt and either of said rolls.

9. In a road paver of the character described,

a carriage, a hopper at the front end of said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, meansv mounted on said carriage for grading the paving material discharged from said hopper opening and means in rear of said hopper opening and grading means for supporting said carriage onthe freshly laid strip of paving material, comprising a front roll and a rear roll having. substantially cylindrical peripheries,. an endless integral smooth steel beltpassing around said rolls,. means for driving one of said rolls and spring means for yieldingly urging said rolls apart.

10. In a road paver of the character described, a. carriage, a hopper at the. front end of said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material dischargedfrom said hopper opening and means in rear of said hopper opening and grading. means. for supporting said carriage on the freshly laid strip of paving material, comprising. a front roll and a rear roll having substantially cylindrical peripheries, an endless integral smooth steel belt passing around said, rolls, means for driving one. of said rolls,,, and means for adjusting said rolls toward and from one another to; adjust the'tension of said belt comprising a horizontally sliding mounting for one of. said. rolls, a pair of. toggle links extending. generally lengthwise of. the line of movement of thepaverand connected at one end to said sliding mounting and at its other. end to a for gradingthe paving material discharged from said hopper opening and means in rear of said hopper opening and grading means for supporting said carriage on the freshly laid strip of paving material; comprising a front roll and a rear roll having substantially cylindrical peripheries, an endless integral smooth steel belt passing around said rolls, means for driving one of said rollsandmeans for adjusting said rolls toward and'from one another toadjust the tension of said belt comprising a horizontally sliding mounting for one of said rolls, two pairs of toggle links extending generally lengthwise of the line of; movement of. the paver and: eachpair con- :nectedfat one end to said sliding mounting and at. itsother end to a fixed part of the carriage and a. screw connecting said pairs of toggle links and adapted when turned to move said pairs of toggle links toward and from one another to extend and retract the links thereof.

12. In a road paver of the character described, a carriage, a hopper at the front end of said carriage. and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening and means in rear of said hopper opening and grading means for supporting said carriage on the freshly laid strip of paving material, comprising a front axle and a rear axle, front and rear rolls mounted on said axles, an endless tread. passing around said rolls, a bearing bracket supported by each of said axles and supporting said carriage, a bar connecting said brackets, a plurality of spaced rollers mounted on said bar and engaging the upper face of the lower stretch of said tread and forming a backing. therefor and means for yieldingly urging said rolls apart comprising a bearing block slidably mounted in one of said brackets and carrying the corresponding axle, a pair of toggle links extending generally lengthwise of said bar and pivotally connected at one end thereto, a spring connection between the other end of said toggle linkage and said sliding block and a transverse screw operatively connected to said toggle linkage to extend and retract the links thereof.

13. In a road paver of the character described, a carriage, a hopper at the front end of said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening and means in rear of said hopper opening and grading means for supporting-said carriage. on the freshly laid strip of paving, material comprising a front roll and a rear roll having substantially cylindricalperipheries, an endless integral smooth steelbelt passing around said rolls, means for driving one of said rolls and means for preventing paving material from flowing over onto the upper face of the lower stretch of said belt, comprising a pair of flexible strips arranged lengthwise of the line of movement of the paver and along the opposite edges of the lower stretch of said belt and means yieldingly; holding said strips and urging saidstrips downwardly into engagement with the upper face of said lower stretch.

14. In aroad paver of the character described,

a carriage, a hopper at the front end of said carriage and having an opening in itsbottom ex"- tending transversely of the line of movement of said. carriage, means mounted on said: carriage for grading the paving material discharged from said. hopper opening and means in rear of said hopper opening and grading means for supporting said carriage on the freshly'laid strip of paving material comprising afrontroll and a rear roll having substantially cylindrical peripheries, an endless integral smooth steel belt passing around said rolls, means for" driving one of said rolls and means'for preventing paving material from flowing over onto therupper face of the lower stretchv of saidbelt, comprising a pair; of flexible strips; arranged" lengthwisewof the line. of movement. of. the pawn and along the opposite edges of thelbwer stretch. of saidibelt andv means yieldingly holding said strips. and urging said strips. downwardly into engagement. with the. upper'face'of said11owten stretch, the: opposite ends means for supportingsaid cutter bar, means for adjusting saidsupporting means vertically with of said strips entering peripheral grooves provided in the peripheries of said rolls.

15. In a road paver of the character described, a carriage, a hopper at the front end of. said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening and means in rear of said hopper opening and grading means for supporting said carriage on the freshly laid strip of paving material, comprising a front axle and a rear axle, front and rear rolls mounted on said axles, an endless tread passing around said rolls, a

bearing bracket supported by each of said axles and supporting said carriage, a bar connecting said brackets, a plurality of spaced rollers mounted on said bar and engaging the upper face of the lower stretch of said tread and forming a backing therefor, and means for preventing paving material from flowing over onto the upper face of the lower stretch of said belt, comprising a pair of flexible strips arranged lengthwise of the line of movement of the paver and along the opposite edges of said lower stretch of said belt and spring means interposed between said bar and said strips for yieldingly urging said strips downwardly into engagement with the upper face of said lower stretch.

16. In a road paver of the character described, a carriage, a hopper at the front end of said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, means mounted on said carriage for grading the paving material discharged from said hopper opening and means in rear of said hopper opening and grading means for supporting said carriage on the freshly laid strip of paving material, comprising a front roll and a rear roll having substantially cylindrical peripheries, one of said rolls being mounted on a fixed axis and the other being movable lengthwise of the line of movement of the paver, an endless integral steel belt passing around said rolls, means for driving that roll mounted on a fixed axis, spring means for yieldingly urging said rolls apart and means movable with the non-driving roll for cleaning the exterior surface of said belt.

1'7. In a road paver of the character described, a carriage, a hopper on said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, a fiat cutter bar arranged adjacent and parallel with said opening and arranged to grade the paving material discharged from said opening, means for reciprocating said cutter bar longitudinally, means for adjusting said cutter bar vertically and means providing a fine adjustment for'the effective elevation of said cutter bar comprising means providing a tilting mounting for said cutter bar and permitting said cutter bar to tilt about an axis generally parallel and eccentric to its cutting edge and extending transverse of the line of movement of the paver and means for adjustably tilting said cutter bar about said axis to vary the effective elevation of said cutting edge along its entire length.

18. In a road paver of the character described, a carriage, a hopper on said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, a flat cutter bar arranged adjacent and parallel with said opening and arranged to grade the paving material discharged from said opening, means for reciprocating said cutter bar longitudinally,

reference to said carriage and means providing a fine adjustment for the elevation of said out ter bar comprising. a link pivotally connected to said supporting means and extendingforwardly therefrom generally parallel with the line of movement of the paver, means pivotally-supporting the front end of said link on said carriage,

and means for adjustably rotating said supportl ing means about its pivotal connection with said link thereby to adjust the vertical position of the cutting edge of said cutter bar.

19. In a road paver of the character described,

a carriage, a hopper on said carriage and having an opening in its bottom extending transversely 'of the line of movement of said carriage, a flat cutter bar arranged adjacent and parallel with said opening and arranged to grade the paving material discharged from said opening, means for reciprocating said cutter bar longitudinally,

means for supporting said cutter bar, means for adjusting said supporting means vertically relative to said carriage and means providing a fine adjustment for the effective elevation of said for adjustably rotating said second bracket to effect a tilting movement of said first bracket anda corresponding vertical movement of thecutting edge of said cutter bar.

t -In a road paver of the character described, a carriage, a hopper mounted on said carriage and having an opening in its bottom extending transversely of the line of movement of saidcarriage, a supporting bar arranged in rear of said hopper and extending transversely of the line of movement of said carriage, a cutter bar arranged parallel with said supporting bar and arranged to grade the paving material discharged from said opening, supporting means carried by said cross bar and supporting said cutter bar and permitting longitudinal reciprocation thereof, means for adjusting said supporting bar vertically relative to said carriage and means for reciprocating said cutter bar comprising a motor cylinder mounted on said supporting bar, a piston in said cylinder, a piston rod connected to said piston and extending outwardly from said cylinder, means operatively connecting said piston rod with said cutter bar and means controlled by the reciprocation of said cutter bar for alternately introducing fluid under pressure into said cylinder at opposite sides of said piston to effect reciprocation of said piston.

21. In a road paver of the character described, a carriage, a hopper mounted on said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, a cross bar arranged in rear of said hopper and parallel with said opening, a cutter bar arranged parallel with said dross bar and airranged to grade the paving material discharged from said hopper opening, means for supporting said cutter bar from said cross bar and permitting longitudinal reciprocation of said cutter bar, means on said cross bar for reciprocating said cutter bar and means for independently raising and lowering the opposite ends of said crossbar comprising a hydraulic jack arranged at each side of said carriage and operatively connected with the corresponding end of said crossbar and means on said carriage for selectively-admitting fluid under pressure to said hydraulic jacks.

22. In a road. paver of the character described, a carriage, a hopper mounted on said carriage and having an'opening in its bottom extending transversely of theline of movement of said carriage, means connected with said carriage for a carriage, a hopper mounted on said carriage and having an opening inits bottom extending transversely of the line of movement of said carriage, means connected with said carriage for grading the paving materialdischarged from said hopper opening, atractor assembly supporting each side of said carriage and arranged in rear of said hopperopening and grading means and supporting the entire weight of said carriage exclusively on the freshly laid strip of paving material, each of said tractor assemblies including front and rear rolls and an endless tread connecting said rolls, and means for propelling, the paver comprising .a prime mover mounted on said carriage, a hydraulic pump driven by said prime mover, a hydraulic motor operatively connected to one roll of each tractor assembly and means for selectively delivering fluid under pressure from said pump to said motors thereby to permit of steering the paver.

24. In a road paver of the character described, a carriage, a hopper on said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, a cutter bar arranged adjacent the rear wall of said hopper and serving to grade the material being discharged therefrom, means for reciprocating said cutter bar, means for adjusting the elevation of said cutter bar and means for preventing the paving material in said hopper from escaping over said cutter bar, comprising an upstanding plate secured to said cutter bar ex-v tending lengthwise thereof and arranged .immediately to one side of the plane of the rear wall of said hopper and sealing the opening therebetween. V

25. In a road paver of the character described, a carriage, a hopper on said carriage and having an opening in its bottom extending transversely of the line of movement of said carriage, a cutter bar arranged adjacent the rear wall of said hopper and serving to grade the material being discharged therefrom, means for reciprocating said cutter bar, means for adjusting the elevation of said cutter bar and means for preventing the paving material in said hopper from escaping over said cutter bar, comprising a pair of upstanding plates secured to said cutter bar extending lengthwise thereof and arranged on opposite sides of the plane of the rear wall of the hopper and sealing the opening therebetween.

' AXEL E. LUNDBYE.

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