US1741459A - Road screed - Google Patents

Description

Dec. 3l, 1929. w. HELTZEL 1,741,459

ROAD SCREED Filed Sept. 17, 1927 2 sheets-sheet 1 HAN Dec. 3l, 1929. J. w. HELTzr-:L

ROAD S GREED Patented Dec. 31, 1929 Y A UNi'rE TATES PATENT ori-ics JOSEPH WILLIAM HELTZEL, F WARREN, OHIO ROAD scREED Application filed September 17, 1927. Serial No. 220,284.

The present invention relates to concrete screed being broken away, and parts in rear road finishers or machines which are enibeing omitted for sake of clearness. Y ployed for finishing off the surface of a con- Fig. 2 is a front View of the main screed, crete road under construction, and the inven with the secondary screed removed.

tion has for an obj ect the provision of a novel Fig. 3 is a fragmentary side elevation of the 55 and improved screeding or strike olf device finishing machine on an enlarged scale. by means of which the surface of the road F ig. 4 is a horizontal section on the line may be formed with a crown of desired mag- 4-4 of F ig. 3 on an enlarged scale. nitude or may be made flat such as at turns Fig. 5 is a section on the line 5 5 of Fig. 4. or bends in the road. Fig. 6 is an enlarged section on the line 6-6 60 Another object of the invention is the proof Fig. l through the main and secondary vision in a finishing machine of a main screed screeds.

or strikeoff which is adapted to give the sur- Fig. 7 is a fragmentary elevation of the face of the road the desired crown, in coinlever for flexing the secondary screed, showbination with a secondary screed or strikeoff ing modifications. 65

that is adjustable for gradually decreasing Fig. 8 is a fragmentary view illustrating the crown until the surface of the road is flat another modification in the control of the secand then gradually restoring the crown, as ondary screed. the machine approaches and moves away The main screed or strikeoff comprises an from a bend or turn in the road. It is the angle iron 11 with a forward upstanding 70 practice to crown the road 0r to have the surflange and a lower rearwardly' extending face thereof conveXed transversely when the flange, and a plate l2 of suitable width on road is straight or substantially straight and which the lowei' flange of the angle iron is to have the surface fiat at curves or turns in riveted, welded, or otherwise secured adjacent 5 the road, with the road inclined transversely to the forward edge of said plate. The angle and higher at the outer edge of the curve than iron and plate are of a length greater than at the inner edge, S0 that the utility of the `the width of theroad, so that the vplate'12 of present invention will be apparent.` j the screed is slidable on the side rails or 'Sion of a Secforms 18 which define the sides or edges of the Another object is the provi l 0 Ondary screed of novel Construction t0 be asroad under construction. Deflectors 14 are 80 senibled with a main screed for adjustment to SGCUTQ- t0 the @Ild pOFOIlS Of the angle IOIl decrease the crown of the road until the sur- 1l ilbOW the lbllS 13 Ol CleflGCtlIlg the maface of the road is flat, and vice versa, and tGIll inwardly.

attrait@entre that narrante naar 85 screed l y t i A loosely at their forward ends with the angle V-lew Whlch Wm be appment as th-e'descmplonoitudilfially of itself transverseljgrofctleie 40 non poceedsthe mventmn resldes 1n the Conroal. The screed is reciprocated bv means of 90 dtructlon and arrangeme-nt of .part-stas here' a rock shaft 17 having` an arm 18u connected mafter descrlbed and damned 1t heilig under" by a link 19 with thebscreed and the screed sood that chailges .can be made Wlthm @he may be lifted off the road by ineans of chains Scope of ls Claimed Without depatmg or flexible elements 20 connected tothe screed from the Spuit of .thi mventlon'. and to a transverse shaft 21 mounted on the 95 The invention is illustrated in the accom- Carriage Or frame 16 for Winding the Chains panying drawings, whereinthereon A Figure l le a TOD View Of 2L COIlClet@ lOfLd The main screed above described is adjustfinisher having the improvements iIlCOrpO- able, being resilient so that it may be bowed 100 rated therein, a portion of the secondary Vor sprung upwardly intermediate its ends.

TSI

In order to adjust the screed to the desired crown of the road, a truss 22 is secured at its ends to the angle iron 1l near opposite ends thereof, and an adjusting bolt or stay 23 is connected to the central portion of the screed and passes upwardly slidably through the cen ral portion of the truss 22, and nuts 24 are threaded on said bolt above and below the truss. By adjusting the nuts 24 the central portion of the screed may be raised and lowered to bend or bow the screed to the desired crown or curvature.

The secondary screed or strikeoff is adapted for attachment to and removal from the main screed, being a separate and distinct unit although when assembled with the main screed the two screeds cooperate one with the other. The secondary screed comprises an angle iron 25 having a rear upstanding flange and a. lower forwardly extending flange. The rear flange bears rearwardly against the upstanding flange of the angle iron 11, as seen in Fig. 6. rlhe secondary screed also includes a rearwardly inclined upwardly extending plate 26 having a rearwardly extending flange 27 at its lower edge secured on the lower flange of the angle iron 25 by means of bolts 28, rivets or other securing elements. The angle iron 25 and plate 26 are resilient so as to be capable of being sprung or bowed. The plate 2G being` inclined rearwardly will facilitate the springing of said plate, and to further facilitate springing` of said plate it may be formed with slits 29 and 30, as seen in 1Eig. l. The slits 29 extend upwardly from the lower edge of the plate 26 and through the flange 27 while the slits 30 extend downwardly from the upper edge of the plate, said slits being in staggered arrangement. Then the plate 26 is sprung upwardly between its ends the upper slits 30 open slightly and the lower slits 29 close, while the lower slits 29 open slightly and the upper slits 30 close when the secondary screed is straightened out.

The secondary screed is disposed in front of the main screed between the dellectors 14, and the plate 26 will serve as a baffle to prevent the aggregate in front of the screeds from passing over the screeds.

In order to attach the secondary screed to the main screed, bolts 31 or other securing elements are carried by the angle iron 25 near the ends thereof and pass through horizontal slots 32 in the angle iron l1 of the main screed, thereby permitting the secondary screed to be sprung without interference.

The means for adjusting the secondary screed includes a lever 33 extending from the fender of the machine to one side thereof and fulcrumed on a bracket 34 bolted or otherwise secured tothe truss 22 of the main screed. Said lever has a short inner arm connected by a link 35 with the angle iron 25, whereby the long arm of the lever may be -adj usted upwardly and downwardly for bowing or straightening out the secondary screed with considerable leverage.

In order to conveniently adjust the lever 33, a slotted post 36 is secured to the angle iron 25 at one end thereof, and a nut 37 is slidable vertically in said post and has a pin and slot connection 38 or other suitable connection with the lever 33. The nut 37 engages a vertical screw 39 mounted in the post 36, and said screw has a hand wheel 40 at its upper end whereby the screw beconveniently rotated to raise and lower the nut 27 and long arm of the lever 33.

When the machine is operating along a straight or substantially straight stretch of road, the secondary screed may be bowed or sprung upwardly so that its lower surface (lower surface of the bottom flange of the angle iron 25) is flush with the lower surface of the plate l2, in order that the secondary screed will cooperate with the main screed for crowning the surface of the road, although if desired the secondary screed may be sprung higher than the plate 12. l/Vhen the machine is approaching a curve or bend in the road, the hand wheel 40 may be turned slowly or at intervals so as to gradually raise the long arm of the lever 33 and depress the link 35 and intermediate portion of theV secondary 9 screed, in order that the crown of the road will be gradually reduced and eliminated until the secondary screed is straight to produce a flat surface in the road at the bend or turn, and as the machine moves away from the bend or turn the hand wheel 40 may be rotated in the opposite direction to gradually spring the secondary screed upwardly and thereby restore the crown. It is thus possible to manually adjust or set the secondary screed to reduce and eliminate the ycrown and then gradually restore the same, for predetermined distances.

rlfhe adjustment of the secondary screen may also be accomplished automatically from a gear wheel 4l or other wheel or membery which is rotatable with the propelling mechanism ofthe machine. The gear wheel 4l may be a part of the gearing which propels the machine, so that the wheel 4l rotates in accordance with the movement of the machine on the side rails. Therefore, by operably connecting the wheel 4l and screw 39, the secondary screed may be adjusted in ratio to the distance of movement of the screed. As shown, a pinion 42 meshes with the gear wheel 41, and a shaft is slidable through said pinion and is rotated therewith.v A hand lever 44 is provided for sliding the shaft, and a pair of bevel gears 43 are secured on said shaft 45 to mesh alternately with a bevel gear 47 secured on a exible shaft 46 which has a worm 48 carried by the post 36 and meshing with a worm wheel 49 secured on the screw 39 below the hand ist wheel 40. The shaft 46 has universal joints 50 and a telescopic joint 5l to permit of flexibility, so that the screw 39 may reciprocate with the screeds without disturbing the operative connection. By moving the hand lever 44 either bevel gear 43 may be brought into mesh with the bevel gear 47, so that the screw 39 may be rotated in either direction for raising or lowering the long arm of the lever 33. It is thus possible to gradually straighten out and then bow the secondary screed through predetermined distances of movement of the machine when approaching and leaving a bend or turn in the road without requiring manual adjustment, other than the making and breaking` of the connections between the driving member of the machine and the screw 39. If manual adjustment is desired the worm 48 or worm wheel 49 may be loosened so as not to interfere with the rotation of the screw 39 by the hand wheel 40.

The screeds are made of metal, and the main screed is fairly rigid, so as to be substantial when sprung to different curvatures, while the secondary screed is more freely bendable to be quickly bent from full-crown to straight position and vice versa.

In some cases the secondary or front screed may be bowed slightly higher than the rear or main screed, so that the intermediate portion thereof is one-eighth of an inch (more or less) higher than the intermediate portion of the main screed. The front or secondary screed will then finish the surface slightly higher than intended, and the main screed following will finish off' the surface to the desired crown, and the material or aggregate will be smoothed out so as to eliminate all voids and thus produce a smoother surface or finish.

Fig. 7 shows the lever 33 corresponding with the lever 33 above described, projecting through the post 36 and provided with a handle 40 for swinging said lever, and the lever may be held in various positions by means of a pin 37 inserted through apertures in the lever and post, whereby the secondary screed may be maintained in different flexed positions. By swinging the lever the secondary screed may be bent upwardly and downwardly, and the lever may be changed by removing and inserting the pin 37 as the machine moves predetermined distances.

Fig. 8 illustrates another modification in the means for controlling the secondary screed. Thus, a nut 37 is carried by the truss 22 of the main screed, and a vertical screw 39 is threaded through said nut and has a hand wheel 40 at its upper end for conveniently rotating said screw. The lower end of the screw has a swivel connection 35 with the secondary screed, in order that the secondary screed may be conveniently bent upwardly and downwardly, said screw being located at the center of the machine.

Having thus described the invention, what is claimed as new is 1. A secondary screed comprising an angle iron having a rear upstanding flange for attachment to the main screed of a. concrete road finishing machine and having a lower forwardly extending flange, and an upwardly extending plate secured on said lower flange.

2. A concrete road finishing machine including a member operable in the propelling of the machine, an adjustable screed, and an operative connection between said screed and member for adjusting the screed as the machine is moved.

3. A concrete road finishing machine having a member movable as the machine is propelled, a main screed, a secondary adjustable screed movable from crown to straight position and vice versa, and an operative connection between the secondary screed and said member for adjusting the secondary screed in either direction in the movement of the machine.

4. A concrete road finishing machine having a member operable by the propelling of the machine, a main screed, a secondary screed having its end portions connected with the main screed, and an operative connection between the intermediate portion of the secondary screed and said member for s ringing the secondary screed either upwar ly or downwardly by the movement of the machine.

5. A screed including an upwardly extending sheet metal plate having slits extending from its upper and lower edges and in staggered arrangement.

In testimony whereof I hereunto afiix my signature.

JOSEPH WILLIAM HELTZEL.

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