US2084068A - Road finishing machine - Google Patents

Description

June 15, 1937. w. u. VINTON ROAD FINISHING MACHINE Filed March 1'7, 1934 4 Sheets-Sheet 1 June 1937- w. u. VINTON 2,084,06

ROAD FINISHING MACHINE Filed March 17, 1934 4 Sheei s;Sheet 2 .fm/entor William [1. Vz'nzon y %gj% A Ztorney June-35,, 1937. w. u. VHNTON ROAD FINISHING MACHINE- Filed March 17, 1934 4 Sheets-Sheet 3 Attor ey W. U. VINTON ROAD FINISHING MACHINE June 15, 137

4 Sheets-.-Shee. 4

Filed March 17, 1934 Inventor William H Vinton Attorney Patented in... 15, 1937 UNETED STATES PATENT oFFlcE 21 Claims.

The invention provides a continuous longitudinal road finishing machine, that is to say, a machine for use in the forming of concrete roads and the like, its screed lying longwise of the roadway, and its action being automatic and continuous.

The operations that are usual in laying concrete roads, and the machines that are'used in performing those operations, are frequently referred to hereinafter, in describing the present invention. Ihe usual practice is therefore now described as follows:-

First usual operation.The paver, so called, advances intermittently, this being a power machine that mixes the concrete, deposits it at different places in the width of the roadway, and spreads it, approximately only, to the desired road surface.

Second usual operation-Close behind the paver a finishing machine, so called, usually follows. This machine is also a power driven machine. It may better be described herein as a transverse finishing machine, because its screed lies transverse of the roadway, this name distinguishing it from the present invention, which is a longitudinal finishing machine. The screed of said transverse finisher reaches right across the roadway, its ends resting upon the forms at the edges of the roadway, whereby the depth of its out is regulated by said forms.

Said screed has an oscillatory movement, longwise of itself, and at the same time it advances with the machine as a whole, along the roadway. Said screed is arched to conform to the crown desired for the roadway.

Third usual operation-After the said transverse finisher, a hand-operated treatment usually follows, and it is this hand operation that the present invention is designed to replace. The

hand operation is as followsz-Two bridges stand across the roadway- A bull float" lies longwise of the roadway, in the gap between the two bridges. And two men, on the bridges, grasp plow handles attached to the fi'oat and work it,

entirely by hand power, its function being to smooth down the undulations left by the transverse finisher.

Fourth usual operation.Finally a belting machine, so called, usually follows, in order to give a roughness to the actual surface, to provide a grip for rubber tires.

As stated above, it is in the third of the foregoing four operations that the present invention is meant to be employed. That is. to say, it will replace the hand-operated longitudinal screed of float by a power-operated longitudinal screed, for use in correcting the faults left by the transverse screed of the transverse finisher.

When the present invention is employed for said third operation, said first, second and fourth operations will still be desirable, andwill still be performed in the same way as hitherto, except that fewer treatments bythe transverse finisher, second operation" above, will then suillce. Whereas it is now usually specified that said transverse finisher must return and advance over the same ground again, covering the ground perhaps as many as three times in all, it will then sufiice for it to cover the ground once only. Thus a saving will be efiected in respect of said second operation, in addition to advantages in the operation which the present invention itself performs, namely, the third operation.

Truth of the riding surface in the direction of trafiic, that is, longwise of the road, is obviously more important than truth in the crosswise direction. And the present invention, by introducing mechanical accuracy into the longwise treatment of the road, supplies the desired truth in the longwlse direction, thus enabling the ever increasing stringency of the regulations of highway departments to be met.

Another advantage is that, being power driven, the invention can deal with concrete of a stifier consistency than the hand fioat can. Accordingly, a. longer time-interval can be allowed to precede it. Thus it may be timed to follow the transverse finisher after an interval which allows the concrete to approach its initial set, by which time much of the excess water of the wetter batches of concrete deposited by the paver will have had time to escape into the sub-grade or into the air, whereby the concrete as a whole will have become more uniform in consistency, and consequently the tendency for hollows to be formed, due to unequal final shrinking, subse-- quent to all operations, will be reduced.

Other advantages will appear in the course of the description.

In the drawings:

Fig. 1 is a plan of a complete machine with some minor parts broken away or removed.

Fig. 2 is an end sectional elevation on line 2-2, Fig. 1, with some parts broken away and some parts removed.

Fig. 3 is a cross sectional elevation on line 3--3, Fig. 1, with some gearing removed.

Figs. 4 and 5 are details of the main-shaft reversing clutch shown in Fig. 1, Fig. 4 being a plan, and Fig. 5 being an end view, both being partly in. section.

Fig. 6 is an end elevation showing detail of some of the gears of Fig. 2.

Fig. 7 is a diagram, showing the general course travelled by the screed relative to the direction of the road, the oscillatory movement of the screed endwise of itself being here disregarded. Fig. 8 is a diagram, showing all of the three simultaneous movements of the screed, namely,

oscillating, and transverse of the road, and advancing along the road.

Figs. 9 and 10 show the retarding device which retards the forward end of the screed, Fig. 9 being a side sectional elevation, and Fig. 10 being a front elevation.

Figs. 11, 12, and 1-3 are details of the shoe at the rear end of the screed, and associated parts, including automatic lift-over mechanism. Of these'figures, Fig. 11 is a plan; Fig. 12 is a side elevation, that is, viewed from the side of the screed, the view being sectional, on line I2-l2, Fig. 13, and the hinged plate being removed; and Fig. 13 is a front elevation, that is, viewed longwise of the screed, partly in section.

Referring to the drawings:-

The action of the machine will be best understood by referring first to the two diagrams, Figs. 7 and 8:--

In Fig. 7, the screed l, in position I, is ready to start. The roadway 2 is to be finished or screeded, and the arrow 3 represents the direction of advance of the machine as a whole as it works, the main part of the machine at rear being here indicated by the charend 8 still having the same tardiness. in relation to said rearward end 5.

At the point 9, the crosswise travel mechanism reverses, whereupon the second stroke of the machine begins. Said rearward end 5 then travels a short distance to the left without said forward end 6 having begun to travel, until position III is reached, in which position said forward end 6 slants as much to the right as originally it did to the left. Then the whole screed begins to move, and moves, at a constant slant, to the left, treating the shaded parallelogram or diagonal zone l0, until position IV is reached. Then, at point II, reversal again takes place, and the third stroke of the machine begins, it now travelling again to the right.

At position V the forward end of the screed again slants to the left, as it did at position I, and the treatment of the shaded parallelogram or diagonal zone Ila begins, which treatment is, in the diagram, discontinued at position VI.

The overlapping of the zones is such that all parts of the road surface, after the machine has finished its first stroke, receive two treatments at least. In order to demonstrate this fact, said parallelogram or diagonal zone l0 may be taken as an instance, as follows:-

Assume, then, that said second stroke of the screed has just been completed, during which stroke it has treated the whole of said parallelogram l0, and has halted at said position IV. Said parallelogram l0 may be said to consist of two triangles, namely, a lower triangle l3 and an upper triangle i4, separated by the broken line i5. Therefore both of said triangles have Just received' a treatment, the result of said second stroke. But said lower triangle i 3 had already received an earlier treatment during said first stroke of the screed, making two treatments in triangle.

all for the lower triangle; and said upper triangle i4 is just about to receive a second treatment, as part of said third stroke of the screed, which will make two treatments in all for the upper That is to say, the whole of said parallelogram III has been, or will be as the machine proceeds, treated twice.

There is, moreover, a small portion of said parallelogram I! which receives a total of three. treatments, namely, the narrow strip lia which lies between said broken line I! and the broken line It. But there is no portion which receives less than two treatments.

Generalizing from the preceding two paragraphs, it is to be noted that, after the first stroke of the machine, no portion of the road surface receives less than two treatments. Also that the two treatments are from almost opposite directions, which is of great importance, as is hereinafter explained.

Also it is to be noted that sometimes the right-hand edge I! of the screed is the screed's leading or cutting edge, and sometimes the lefthand edge is such.

Referring more particularly to Fig. 8:-

A movement not indicated in Fig. 7 is a constant oscillation of the screed endwise of itself.-

That oscillation is indicated in Fig. 8, in which figure the point [9, chosen as an instance, in said screed i, will, if the machine is started, trace the path indicated by the line Ila, due to the three simultaneous movements of the screed, namely, first, its movement of translation to the right, across said roadway 2; second, its movement of advance, along said roadway; and, third, its movement of oscillation, endwise of itself.

While a screed is being translated, sideways of itself, in its work, it may push protruding stones in the direction of its translation, leaving holes in the concrete at rear of such stones. This is apt to happen notwithstanding the smoothing effect of any simultaneous oscillatory movement of the screed, endwise of itself. But, if the screed can be made to work back again over the same ground, in substantially the opposite direction, said holes will be filled up more effectively than if the screed went back empty, and then covered the ground a second time in the original direction. Hence the importance of the fact demonstrated hereinabove that, in the present invention, the screed, in the regular course of its movements, treats all parts of the road surface twice, from substantially opposite directions.

'The object in retarding the forward end of the screed as described is three-fold. First, it increases the tendency to push forward, as well as sideways, relative to the road, the excess concrete which the working edge of the screed dislodges. Second, it avoids an exact parallelism in the ,two treatments aforesaid of the surface, thereby avoiding any tendency to accentuate, in the second treatment, any ridges and furrows left by the first treatment. And, third, it reduces the tendency of the paving material near the rear end of the screed to escape round that end, and thus to form a ridge across the pavement.

Trains or groups of gearing contained in the machine are as follows:

Referring more particularly to Figs. 1, 2, and 32- The engine 20 drives the power output shaft 2|, which, by means of suitable gearing, drives the first cross shaft 22, which in turn, by means of suitable gearing, drives the second cross shaft 28.

Said second cross shaft 28 actuates what may be described as the second train of gearing, as follows:--

Said second cross shaft 23 drives the central bevel wheel 24, which is always-in mesh with the 5 two bevel wheels 25 and 26. These wheels, co-

operating with the clutch gear hereinafter described, cause the main shaft 21 to be driven in one direction or the other, there being no pause at neutral position. Said first cross shaft 22 actuates what may be described as the first train of gearing, as follows:-

Said first cross shaft 22 by suitable gearing drives the sliding shaft 29, Fig. 1, which, by means of the small pinion 30 at its end, drives the large pinion 3| when saldsliding shaft 29 is slid into gear by means of the clutch lever 32, Fig. 3.

Said large'pinion 3| is integral with a sleeve 33 which sleeve has at one end the clutch dogs 34, and carries at its other end the sprocket 35, which, by means of the chain 36 and sprocket .31, drives the sleeve 38, which drives the travel shaft 39, which drives the travel wheels 46 and 4|, which wheels, rolling respectively upon the forms 42 and 25. 43, placed at, the edges of said roadway 2, cause the whole machine either to advance in the di rection of the arrow 44, or to retreat.

Further details of the gearing in said two trains are given at the end of this specification.

The moving of the machine as a whole is accomplished as follows: v

When the engine is running, said first and second'cross shafts 22 and 23 are both always running.

Said first train of gearing gears downward. Consequently, when said first train is in gear with said large pinion' 3|, as hereinabove described, the machine travels at its slower speed, and such slow travel is in one direction only, namely, the

40 forward direction.

But, when said sliding shaft 29 is out of gear with said large pinion 3|, the clutch may be put into gear with said clutch dogs 34, whereupon said large pinion 3| will be caused to drive 45 said travel shaft 39 at its faster speed, to travel the machine at its faster speed, either advancing w or retreating, according-to the direction in which said main shaft 21 is running at the moment. The endwise oscillating of the screed, hereinbefore described, is accomplished as follows:-

Said main shaft 21 has at its ends the cranks 48 and 49, actuating the connecting rods 56 and 5|, causing the oscillator bar 52 to move backward and forward of the roadway, whereby, with I A worm 56, upon said main shaft 21, gears into the worm wheel 51 running idle upon the screed: chain driver-shaft 58 at the right of the machine;

70 When the clutch 59 is thrown into gear with said worm wheel 51, said driver shaft is caused to revolve in one direction or the other, according to the direction in which said main shaft 21 happens to be running at the moment.

76 Sprockets 69 and 6|, mounted upon said driver shaft 56, operate the rearward and forward screed- chains 62 and 63, which chains pass over sprockets- 63a and 63b mounted upon a driven shaft 64, provided at the left of the machine. The ends of said rearward screed-chain 62 are at- 5 tached at points 65 and 66, Fig. 3, to the rearward shoe 61 at the rearward end of said screed And, similarly, the ends of said forward screed-chain 63 are attached to the forward By these means the screed is translated from side to side of said roadway 2, its direction, either to right or to left of. said roadway, depending upon the direction of rotation, at the moment, of said driver shaft 53, which in turn depends 15 for its direction upon the direction, at. the mo-- ment, of said main shaft 21.

second, a movement of oscillation of the screed 30 endwise of itself and third, a movement of translation of the screed across the roadway. And it will be noted that all three of such movements can be caused to occur simultaneously.

The engine and most of the gearing above described are carried on the non-continuous platform 68a, which is carried by the frame ,69 of the machine.

The reversing of the direction of translation of the screed, from one side of the road to the 40 other, at the right moment, is accomplished as follows Referring more particularly to Figs. 1, 4, and V In Fig. 4 the full lines show the reversing mech- 45 anism when on dead centre and just about to spring over; and the dotted lines show the condition after the spring-over has taken place.

Said rearward screed chain 62 .passes through the channel-shaped, guide 10, and carries the 50 chain stop 1|. Said channel 10 is attached by means of the plate 12 to the sliding block 13 into which block is pivoted the vertical post 14, having upon it the swinging horizontal arm 15.

When said stop 1| during the course of its travel upon said chain in the direction of the arrow 12a, Fig. 4, meets said channel, it pushes said channel along in front of it, meantime compressing the spring 16 until said swinging arm 1 15 is in line with the clutch arm 11, a dead-centre condition having been thereby reached. A momerit later, whilethe chain still travels, the

spring-over takes place, causing said block 13 to slide a little further to the right, as shown by the dotted position of said block in Fig. 4, where it is stopped by the block-stop 19, the block carrying with it said channel 10, and said post 14, and said swinging arm 15.

The spring meantime causes said swinging arm 15 to assume its dotted position, Fig. 4,. which in 70 turn causes said clutch arm 11 toassume its dotted position, which in turn, by means of its downwardly projecting finger 82, causes the ,clutch member 83 toslide out of engagement with said bevel wheel 25 and into gear with said -bevel wheel 20, (the new position of said clutch member being not shown in the drawings) thereby causing the direction of said main shaft 21 to be reversed.

Immediately thereupon, said chain 02 travels in the opposite direction, carrying said chain stop 1I away from said channel, and eventually bringing a second chain stop, not shown, to push the channel at its other end, and to thereby again reverse the movement at the right moment.

Said clutch arm 11 is pivoted at 84. Attached to it is the swivelling eyelet 05, through which said swinging arm 15 is free to run.

In practice, a hand-operated mechanismis Fig. 1.

The retarding of the forward end of the screed hereinbefore described, is accomplished as follows:-

Referring more particularly to Figs. 1, 9, and 10:-

Said screed-chain driver-shaft 59 has its said forward sprocket 0| running loosely upon it, while. near said sprocket, the gapped wheel 90 is fixed rigidly to said shaft. The pin 9|, projecting in axial direction from said sprocket, enters the arcuate gap 92 provided in said wheel 90.

When said driver shaft 58 is put in motion in either direction, the 'fact that said forward sprocket 6| is loose upon it causes said forward screed chain 63 to remain without motion until said pin 9| has reached either end of said gap 02,

as shown by the two dotted positions of said pin in Fig. 10, whereupon motion of said screedchain will begin, because said sprocket GI will then be driven by said gapped wheel 90.

Upon said driven shaft 64, whereas the rearward sprocket 63a is rigid, the forward sprocket 83b is loose, permitting the latter to accord itself to any lost motion of said driver-sprocket GI. Accordingly, said forward screed-chain 93, attached at its ends to said forward shoe 68 as hereinbefore described, transmits the movements of said sprocket 6i, including the losses in motion of said sprocket, to said shoe, therebyeffecting the desired retarding of the forward end of the screed.

Mechanism for governing the working'depth of the screed is as follows:

Referring first more particularly to Figs. 1, 2, and 3, the rear template 95 and the forward template 96, Fig. 1, are rigid members arched to the desired road contour, as shown in side view in Fig. 3, and are attached to contiguous parts of i said frame 69. Said rearward and forward shoes 61 and G8 are supported respectively .by said templates, upon which they are free to run or slide; and said screed- chains 62 and 63 pull said shoes either to the right or to the left across the roadway, as hereinbefore described.

By these means, the weight of the screed is carried by the templates, and the templates, in turn, are carried by, or are a part of, the machine itself. And it follows that the regulating of the depth of the cut of the screed is a matter relative to the templates, or to the frame of the machine, quite independently ofthe forms.

This arrangement is in contrast with that of the transverse finishing machine described in Second usual operation" above, in which the screed rests, not upon the machine, but upon the forms at theedges of the road. That transverse finisher has also further disadvantages as follows:(l) Any unevennesses in the forms directly affect the screed, causing ridges and furrows crosswise of the roadway, whereas'in the present invention the length of the wheel-base of the machine softens said unevennesses of the forms;

(2) In the transverse machine, the fact that the forms which carry the screed, and the machine that moves the screed, are separate entities tends to cause a vibration in the transmitting of the motion, resulting in crosswise furrows; and (3) In the transverse machine, the screed must be a long one, because it must span the whole roadway, and therefore must be correspondingly strongly braced and heavy, to prevent any springing of its arch during work, which would cause untruth in the road contour; whereas in the present invention the screed can be as short as may be found convenient.

That-is to say, several marked disadvantages, inherent when the screed rides upon the road "forms, are eliminated by the present invention,

- in which the screed rides upon templates, which in that direction; whereas, in the present invention, the movement of the screed sideways of itself is relative to the frame of the machine.

An automatic lift-over" mechanism, for preventing concrete from being wiped off, over the forms, at the sides of the road, is as follows: 1'3Referring more particularly to Figs. 11, 12 and In those figures the screed I, with its rearward shoe 61, is shown near the other end of its cross: wise travel, as compared with Figs. 1 and 3.

Said rear template 9! is attached to a contiguous portion of said frame 69 of the machine, Fig. 12, as hereinbefore related. Also attached to said frame is the bracket 91 from which are suspended the rigid plate 90, Fig. 13, and the hinged plate 99. The latter ishinged to said rigid plate by the hinge I00, and is permitted to rise upward by the bolts IOI passing freely through the slots I02 in said bracket 91. I

Upon said template 95 said rearward shoe 61 slides, ashereinabove described, during most of the Journey of the screed from side to side of the roadway, at which times. the screed forms the concrete to the line I03, Fig. 13, as shown by the dotted position VII of said screed I.

Rising from said shoe are brackets I05 and f I08 carrying inwardly projecting lips I01 and I09.

Referring to Fig. 13:-When the screed I is at said dotted position VII, said lip I 01 will be at its dotted position VII. Thereafter, while the movement of the mechanism progresses further to the right, pulled by said rearward screed chain 82, said lip I01 will slide upward upon said hinged plate 99 until it reaches its full-lined position aforesaid. It will then have'lifted said shoe 61 to its suspended position, as shown in full lines in the drawings, and, at the same time, will have lifted said screed I from said dotted position VII p a,os4,oos to its full-lined position, during which time said screed will have formed the concrete I09 to the line III! at a higher elevation than the dotted line III, to which it is'desired, eventually, to form it.

Continuing the whole movement still further to the right, said lip- IIi'I will keep said shoe suspended until said lip has passed beyond said rigid plate 98. Thereupon the ,whole 01' the suspended mechanism will drop. That'is to say, said shoe 8! will again rest slidably upon said template 95, while said lip I01 and screed I will be in the dotted position VIII. The automatic reversal of the direction of sideway travel of the screed,

in so doing, passing along said dotted line III,

while said lip I01, leaving its said dotted position VIII, will pass under said rigid plate 99,.lifting the latter to enable it so to do, the latter thereafter dropping to its normal position ready fora repetition of the process. v A corresponding automatic lift over mechanism is provided at the other end of said rearward template 95. Also the mechanisms are repeated in respect of said forward template 96.

By these means such amount of concrete as is pushed along by that edge of the screed which is, at the time, the working edge, is not swept over the form, but is swept inward of the roadway, to fill up low places.

Some further details of Figs. 11, i2, and 13 are as follows:---

A U-bracket I I2 suspends the screed by means of the adjustable hanger-bolts II 3 from the axle II4 of the wheels H5; running on said shoe 61. Bythese means the height of the screed relative to the shoe, andhence relative to the template, is adjusted, while the wheels facilitate the oscillation aforesaid of the screed endwise of itself.

Also, the employment of said U-bracket II 2 makes it possiblefor said template to stand at a convenient clearance above the concrete, while none, the less carrying the weight of the screed.

as aforesaid, consists of a worm I I9, carried upon said "shaft 2i, gearing into the worm-wheel I20 on said cross shaft 22.

The gearing aforesaid, as between said first and second cross-shafts 22 and 23, consists of sprockets I2I and I22 on said shafts respectively, geared together by the chain I23.

The gearing aforesaid, as vbetween said =first cross-shaft 22 and said sliding shaft 29, consists of the worm- I24 carried upon said cross shaft, gearing into the worm-wheel I25 carried upon the jack-shaft I26, which shaft carries also the pinion I21, gearing into the pinion I28 upon said sliding shaft.

I claim:

1. A road finishing machine 7 comprising a screed, means for causingsald screed to automatically treat twice, from substantially opposite directions, a portion of a roadway. and means for causing the angular set 'of the leading edge of said screed, during said second treatment, to be substantially out of parallel with the angular set which had been employed by the leading edge during said first treatment.

2. A road finishing machine comprising a screed, means for continuously translating and returning said screed in a direction substantially transverse of its length while such screed operates, and automatic retarding means for causing the front end of'said screed to lag behind its rear end during such translations and returns.

3. A road finishing machine comprising, when in position upon a roadway, a screed lying substantially longwise of the roadway, means for translating said screed from side to side of the roadway, and automatic means for raising said screed above its operating elevation when near the end of a translation and for lowering same ,again before its return translation, whereby excess paving material may be wiped inward of the roadway rather than be .wiped off the roadway.

4. A road finishing machine comprising a. machine frame, a screed, means for translating said screed in a direction substantially transverse of its length and for returning it in the opposite direction,'a lip attached to said screed, and a hinged sloping plate attached to said frame, said plate being adapted to co-operate with said lip to liftsaid screed above its working elevation during translation in said first direction, and being adapted to allow said lip to pass under it during said return. I

5. A road finishing machine comprising a screed, a shoe at a higher elevation than said screed, a bracket attached to said screed and supported by said shoe, a track along which said shoe is adapted to be travelled in a direction crosswise of said screed, and a guide extending downward from said shoe adapted to prevent tilting of said screed sideways of itself during operation.

6. .The method of making a concrete road and truing its surface which consists in spreading concrete to a first approximation in respect of truth of surface, and thereafter reaching a second and a third approximation respectively by means of two cutting operations free from press- 'ing operations, such cutting operations being performed in each case by a mechanically operated screed having a. cutting edge guided by spring-free means to cut to a definite cutting plane in respect of depth, each such screed accordingly cutting off such concrete as stands as excess above said cutting line, and pushing said excess before it, said two screeds lying at substantially different angles in relation to the direction of the roadway.

7. In a road'surface truing machine, a slicing and pushing screed adapted to slice off the high parts from a mass of plastic road material without pressing down upon the residue of such.-

its

mass, and to push such sliced off material before ,I

8. In a road surfacetruing machine, a slicing and pushing screed, and means for translating said screed in either direction approximately transverse of its length, said screed being adapted to sliceoif the highplaces from a mass of plastic road material without pressing down upon the residue of such mass, and to-push such sliced of! material before it, when said screed is translated in either of said directions.

10 9. A road pavement truing machine comprising, when in operating position above 'a roadway, a cutting screed, lying approximately at least longwise of the roadway mechanically operated means for continuously translating said screed from sideto side of the roadway,- against the resistance of its cutting, and mechanical,

- non-elasticmeans for automatically controlling translation in the direction of either of said faces, to cut a shaving of substantial depth from a high part of a plastic mass of road material, to push such sliced of! material before it, and to allow substantially allof same to drop downward to fill a depression, said 'screedduring such operations not pressing downward upon the material to displace it.

10. A road pavement truing machine as claimed in claim 9, said side faces rising abruptly and in substantially a straight line from said downward face, whereby said sliced ofi material may befree to drop the more cleanly away from saidfaces.

11. A road pavement truing "machine as claimed in claim -9, said translating -means acting in a. plane substantially close to the plane of travel of the bottom of said screed, whereby tendency to tilt said screed, during said translation of same against the resistance of said material, is a 12. A road pavement truing machine as claimed in claim 9,. said depth controlling means comprising templets transverse of the roadway; means movable along said templets supporting the ends of said screed withoutthe intervention of springs, and means for preventing tilting of said screed relative to said templets in theldirection longwise of said templets.

13. A road pavement truing machine as claimed in claim 9, said depth controlling means comprising templets transverse of the roadway, shoes supporting the screed without the intervention of springs, said shoes being adapted to be moved along said 'templets and having substantial lengthof bearing along said templets to. prevent their tilting longwise thereof, and

means carried by said shoes for substantially preventing the tilting of said screed relative to said show.

'. 14. A road finishing machine comprising when in operating position above a roadway a screed,

means-for continuously translating and returning said screed in a direction substantially transverse of its length while such screed operates,

and.,automatic,retarding' means for causing the.

front end of said screed to lag behind the rear end during such translations and returns, said retarding means comprising a horizontal shaft at each side of the screedfa sprocket it each end of each said shaft, a front and rear chain passing respectively around the front and rear pairs of sprockets and connected to means movable with' the front and rear ends respectively of said screed, whereby said chains are adapted .to translate said screed when said shafts are revolved, said front sprockets being loose upon said shafts, said retarding means further comprising a wheel rigid: upon each said shaft adjacent said front sprockets, and mechanismfor causing lost motion between said front sprockets. T

15. A road finishing machine comprising a screed, means for translating said screed'crosswise of the roadway, and means for reciprocating said screed longwise of the roadway during said wheels and said translation, said reciprocating means com prising a bar extending crosswise of the roadway for substantially the full width of the roadway,

a front stop and a rear stop located on said screed, 'slidable along'said bar, and means operating at the ends of said bar to give said bar a reciprocating movement longwise of the roadway; I e V 16. A road finishing machine as claimed in I claim It, guides being provided for guiding said bar during'said reciprocation, whereby said bar is prevented from exerting angular pressure downward upon said screed.

17. In a road finishing machine, a mechanically operated screed, and mechanical means for translating said screed from 'sideto side of a roadway, .saidmeans comprising shoes, draft ele-.'

ments' attached to said shoes, and brackets at the ends of the'screed, said brackets and screed constituting a unit, the brackets resting by the force -'of gravity upon the shoes, whereby said unit can be removed from the machine without any unfastening.

I 18. The method of making a concrete road, which includes the steps of spreading concrete to a first approximation'of the truth of'surface to be obtained, then subjecting. the concrete in a cutting and pushing action at its surface portion, the direction of said cutting and pushing being substantially crosswise of the roadway, so

as to effect a further approximation of the'final truth of surface to be obtained, and at the same time to cause a substantial proportion of the concrete so cut to he pushed along while lying upon the main laid bodythereof, shifting crosswise of the roadway, thereby to fill voids or depressions in the surface portions of the main body of concrete.

19. The method as claimed in claim 18, said cutting and pushing further causing said substantial proportion of the concrete to be moved to and fro crosswise of the road without being forced off the edge of the main body of concrete the surface of which is being brought to final truth or accuracy. I

20. The method of making a concrete road and truing its surface, which consists in spreading concrete-to a first approximation in respect of truth of surface, and thereafter cutting the upper-surface portions of the concrete in a direction crosswise of the roadway, at the same time shifting the cut portions in a direction laterally across the roadway while lying upon the

Images