US3415173A - Extension attachment for a paving machine - Google Patents

Description

Dec. 10, 1968 J. M. PAUL 3,415,173

EXTENSION ATTACHMENT FOR A PAVING MACHINE Filed Aug. 21, 1967 2 Sheets-Sheet 1 20 FI 5.1 r L IO 14 L F] f is all 22 a4 32 3 n In "I d/ 3| 2 4 o 63 Z a o u o 3 I 5 I 6| v 2 JOHN M. PAUL INVENTOR BY BUG/(HORN, ELORE; KLAROU/ST 8 SPAR/(MN AT 7' ORNE 5 FIG. 4

Dec. 10, 1968 J. M. PAUL 3,415,173

EXTENS ION ATTACHMENT FOR A PAVING MACHINE Filed Aug. 21. 1967 2 Sheets-Sheet 2 zz w y/ JOHN M. PAUL IN VE N TOR BUCKHOR/V, BLOHE, KLAROU/ST a SPAR/(MAN ATTORNEYS United States Patent 3,415,173 EXTENSION ATTACHMENT FOR A PAVING MACHINE John M. Paul, Portland, Oreg., assignor t0 Rogers Construction, Inc., Portland, Oreg., a corporation of Oregon Filed Aug. 21, 1967, Ser. No. 662,158 17 Claims. (Cl. 9445) ABSTRACT OF THE DISCLOSURE This application discloses an asphalt paving machine having a screed for laying down a mat of asphalt of predetermined width and thickness. The machine includes improved screed extension sections incorporating quickcoupling connection means for rapidly extending, in increments as required, the eiIective width of the screed and thus increasing the width of the mat laid. Each screed section, including the main screed section, includes opposite end plates which adjoin similar end plates on adjoining screed sections. One end plate of each screed section is provided with a pair of spaced U-shaped female connecting blocks having a generally wedge shaped inner recess opening in either the forward or rearward direction of travel of the machine. The opposite side plate of each screed section has a pair of spaced, wedge shaped male connecting blocks which slidably interengage the female blocks of the adjacent screed section when inserted within the recesses of the latter 'blocks. This requires that the two screed sections to be joined are moved in a fore-and-aft direction relative to one another. When interengaged, the male and female connecting blocks interlock along dovetailed surfaces of each so as to prevent longitudinal separation of the screed sections in use. The complementary configurations of the male and female connecting blocks inherently limit the extent of sliding interengagement possible so that the various screed sections are accurately aligned with one another when joined together. A stop member on each screed section engageable with the rear end of the connected adjacent screed section is to prevent fore and aft separating movement of the screed sections when the machine is moving.

BACKGROUND OF THE INVENTION (a) Field of the invention This invention relates to screed extension attachments for paving machines and more particularly an improved connecting means for quickly and accurately attaching screed extensions to the main screed of the paving machine.

(b) Description of the prior art Prior known connecting means for screed extension attachments have required an inordinate amount of time, up to two hours or more, to modify a paving machine for paving different widths through the addition or removal of extension sections. Screed sections of prior machines have been bolted to one another at numerous points, and the connections could not be made without dismantling almost totally each screed section into its separate elements. Often too, accurate alignment of the various screed sections required time-consuming shim ming.

Others have attempted to solve the above problem, as evidenced by the US. Patent 3,155,021 to J. F. Sauer et al. The connection means of such patent incorporates an adjusting screw and booking arrangement for drawing together pairs of adjoining screed sections. However, such an arrangement has most of the disadvantages of prior devices in that access to the adjusting screw is difficult. An additional problem with such an arrangement is that the connections become loose when the machine is in operation from vibrations which are usually intentionally induced in the screed members.

SUMMARY OF THE INVENTION The present invention overcomes the problems as mentioned above with respect to the prior art by providing a screed connecting means which enables the rapid joining together of screed sections in accurate alignment without having to disassemble and reassemble any elements of either screed section. The connection is accomplished in only a few minutes through a simple sliding fore and aft interengagement of two screed sections placed sideby-side. When this occurs, wedge shaped male connecting blocks on one side face of one screed section interlock with female connecting blocks on the adjoining side face of the other screed section. The wedging interengagement of the male and female blocks and their complementary configurations provide for accurate alignment of the joined screed sections each time they are connected together.

The principal objects of the present invention are to provide:

1) An improved means for quickly and easily connecting screed extension sections to the screed of a paving machine;

(2) An improved connecting means for joining together screed sections quickly and yet in accurate alignment with one another;

(3) Improved screed extension attachments which can be quickly and accurately attached to and removed from paving machines and which, while installed, will maintain their proper alignment;

(4) Improved screed connecting means which can be incorporated in existing conventional paving machines, screeds and screed attachments;

(5) An improved connection for screed extension attachments which will not become disconnected or loose when subjected to vibrations;

(6) Improved screed extension attachments which are relatively simple and inexpensive to manufacture, install and maintain; and

(7) An improved connection for screed extension attachments which is long-wearing.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the present invention will become more apparent from the following detailed description which proceeds with reference to the accompanying drawings wherein:

FIG. 1 is a side elevational view of a paving machine incorporating the present invention;

FIG. 2 is an enlarged perspective view of a rear end portion of the paving machine of FIG. 1 as viewed from above and slightly to the left and behind the screed of such machine;

FIG. 3 is a side elevational view of the main screed section of the machine as viewed along the line 3--3 of FIG. 2;

FIG. 4 is a side elevational view of a screed extension section adjoining the main screed section as viewed along the line 44 of FIG. 2;

FIG. 5 is a partial rear end view of several connected screed sections taken approximately along the line 5-5 of FIG. 2;

FIG. 6 is a vertical sectional view through the adjoining side plates of a pair of interconnected screed sections taken approximately along the line 66 of FIG. 4, but on a scale greatly enlarged from that of FIG. 4;

. FIG. 7 is a partial top plan view of the side plate portion of the screed section of FIG. 3 taken approximately along the line 77 of FIG. 3; and

FIG. 8 is a partial top plan view of the side plate portion of the extension section of FIG. 4 taken approximately along the line 88 of FIG. 4, but oriented in its proper adjoining relationship with respect to the screed section of FIG. 7.

DETAILED DESCRIPTION With reference to the drawings, FIG. 1 discloses a typical asphalt paving machine indicated generally at 10 having a front end portion 12 including a hopper 14 for receiving asphalt from a dump truck, and a rear end portion 16 incorporating a screed 18 for laying a flat mat of asphalt on a graded surface. Power is transmitted from an engine 20 to an endless track 22 for driving the machine. In general, asphalt dumped into the hopper 14 is conveyed rearwardly by an internal conveyor (not shown) to spreading screws 24 which distribute the material to the ground surface directly in front of the screed 18. A moldboard 26 (FIG. 3) attached to the front of the screed distributes the asphalt evenly and without segregation of the mix, while a strikeoff blade 28 attached to the lower front of the screed meters and precompacts the asphalt ahead of the screed.

Referring to FIG. 3, the screed 18 is pivoted at its upper front end by a pin 29 to a pivot arm 30 carried by the frame of the machine. An adjusting screw 31 is received within a nut member 32 (FIG. 2) on the frame of the machine and abuts at its lower end a block 34 on the upper rear end of the screed for adjusting the angle of attack of the screed with relation to the ground surface.

The screed itself is generally of hollow box-like construction and includes, in addition to the moldboard and strikeoff blade at its front end, a flat bottom screed plate having upturned front and rear ends 41 and 42 re spectively, a rear end plate 44, oppositely disposed side plates 46, and a cover plate 48 which serves as a heat shield. A heat duct or flue 50 extends longitudinally through the interior of main screed section 18 to distribute heat from an oil or gas heater (not shown) carried by the paver to the screed plate. Each of the opposite side plates 46 has a central opening 52 therethrough to permit the transmittal of heat to attached screed extension sections such as shown in FIG. 2. However, an end cover plate such as the end plate 54 of FIG. 2 is placed over the side plate 46 to prevent excess loss of heat through the opposite sides of the screed if there are no extension sections attached.

In the illustrated paver two screed extension attachments 56, 58 are attached to the left side of the paver, as shown in FIG. 2, to extend the effective laying width of the machine. A plurality of such extension sections may be attached to both sides of the main screed 18 to extend the effective width of the screed from, for example, a normal ten feet up to sixteen feet in one-half, one or two foot increments, depending on the width of each extension section. For example, extension section 56 might be two feet wide, whereas extension section 58 might be one foot wide to extend the width on one side of the machine a total of three feet. Screw extensions (not shown) are also available so that the spreading screw 24 distributes material evenly throughout the full extended width of the screed.

With reference especially to FIGS. 2 and 4, each screed extension section 56, 58, like main screed section 18, is generally of hollow box-like construction and has elements comparable to those on the main screed including a moldboard extension 26a, a strikeoff plate extension 28a, a screed plate extension 40a, a rear end wall extension 44a and a top cover plate 48a. The opposite sides of each screed extension section are also bounded by a pair of opposite side plates 46a which are identical to the opposite side plates 46 of the main screed section 18. The only major difference between the two screed sections 56, 58 is the difference in the idth of the two sections, as already noted. The various elements of each screed section just described are bolted or welded to one another as will be evidenced from FIG. 2. Unlike the main screed section 18, the extensions 56 and 58 each have a pair of upwardly extending handles 60, 61, one at the rear end of top plate 48a and the other on a cross brace extending between a pair of gussets 62, 63 which help support the moldboard 26a at the front of the screed section. As previously mentioned, the outer side of the outermost screed section 58 is enclosed by an end cover plate 54 to prevent the escape of heat from such end.

As described thus far, the illustrated screed extension sections do not differ greatly from prior known screed extension sections. The primary difference lies in the manner in which the various extension sections are connected to one another and to main screed section 18, and in the connecting means for accomplishing this. The connecting means are provided on the opposite side plates 46, 46a of each screed section, including main screed section 18. The connecting means includes a pair of longitudinally spaced, generally wedge shaped male connecting blocks 64, 64a, on one side plate 46 of one screed section 18 as shown in FIG. 3, and a cooperative pair of female connecting blocks 70, 70a in corresponding positions on an adjoining side plate 46a of the adjacent screed section 56 as shown in FIG. 4. Thus one side plate of each extension screed section carries a pair of the male blocks, whereas the opposite side plate of the same extension section carries a pair of the female blocks, so that any one screed extension section can be connected to any other screed extension section or the main screed on the same side of the paver. The male blocks on one section sliddingly interengage the female blocks on an adjacent section when the two sections are placed together side-by-side with one slightly behind the other and then moved into lateral alignment with one another in a fore and aft direction.

The male blocks of each side plate are connected by machine screws 65 to the outer face of the plate, one to a forward section of the plate forwardly of opening 52 and the other to a rear section of the plate rearwardly of such opening. The opposed wedging side edge surfaces 66, 67 of both male blocks on each plate converge in the same direction of elongation of the plate.

The female connecting blocks 70 and 70a are each of generally U-shape and include a generally vertically extending base portion 71 and a pair of opposite leg portions 72, 73. The inner edge surfaces of the leg portions diverge to define a wedge shaped recess 74 which is complementary in size and shape to the male connecting blocks 64, 64a. The recesses of the female blocks open in a rearward direction so that by placing the screed section 56 in side-by-side relationship to the main screed section 18 and slightly ahead thereof, and then by moving screed section 56 rearwardly relative to the main screed section, the male connecting blocks of screed section 18 will enter the recesses 74 of the female connecting blocks on screed section 56.

When the male and female blocks of adjacent screed sections are interengaged as shown in FIG. 6, there is an interlocking of the male and female blocks to prevent lateral separation of the connected screed sections from one another through the provision of dovetail bevels on the mutually interengaged side edge surfaces of the male and female blocks. More specifically, the wedging side edge surfaces 66, 67 of each male blocks are beveled inwardly toward one another in a direction proceeding from the outer face 76 of the block toward the opposite inner face thereof. However, the wedging inside edge surfaces 78, 79 of legs 72, 73 of each female block are beveled outwardly away from each other proceeding in a direction from the outer face 80 of the female block to the opposite inner face thereof. Base portion 71 of each female block has an inner edge surface which inherently provides a means for limiting the extent of sliding interengagement of a cooperative male block within the recess of the female block. Thus, with the male and female blocks properly positioned on their respective side plates, accurate alignment of the various screed sections will result every time the sections are connected together without the necessity of making any special adjustments through the use of shims or other means.

The end cover plate 54 of FIG. 2 also carries, on its inside face, male or female connecting blocks as required so that such plate can readily be attached to the outer side plate of the outermost screed section.

For additional rigidity of the connections, if found necessary or desirable, openings are provided through the adjoining gussets 62 and 63 of screed sections 18, 56 and 58 as shown in FIG. 5, and the adjoining gussets are bolted together by bolts 82.

With the male connecting blocks tapering inwardly in a forward direction as shown in FIG. 3, and the corresponding female connecting blocks opening in a rearward direction as shown in FIG. 4, and with the male blocks being affixed to the main screen section on the frame of the paving machine, forward movement of the paving machine will tend to drive the female connecting blocks more securely about the male blocks so that no additional connecting means need be required. However, should the paving machine be reversed, or should the direction of opening of the blocks be reversed, the tendency of the machine would be to slidingly separate the male and female blocks. Accordingly, a stop means 84 is provided at the right hand rear end of at least one of the two connected screed sections, as viewed in FIGS. 5 and 8, to prevent sliding separation of the connected screed sections when the machine is driven in one of its two opposite directions. The stop means includes a sleeve 86 carried by a bracket 88 attached to the upturned rear end of screed plate 4011. An arm 90 is slidable within sleeve 86 and threadedly carries at one end a stop screw 92. When the male and female blocks of adjoining screed sections are interengaged, arm 90 is extended so that it overlaps the rear end of the adjoining screed section, and stop screw 92 is screwed into abutment with the rear end of the adjoining screed section to prevent rearward movement of the latter section relative to the section carrying the stop. Pins 93 extending through the stop arm maintain the arm in its extended position until removed.

With connecting means as thus described, the various screed sections can be connected together or disconnected from one another in the previously described manner in only a very few minutes, where as in the past well over an hour has been required to carry out this operation. Furthermore, existing screeds and screed extension attachments can be easily modified to incorporate the illustrated connecting means. With reference to FIGS. 7 and 8, this is done simply by removing existing side plates of the screed sections and replacing them with side plates 46 and 46a, incorporating the male and female connecting blocks shown. As shown in FIG. 7, each side plate 46 incorporating the male connecting blocks is connected at its opposite ends by machine screws 100 to one flange of each of a pair of upstanding angle members 102, 103 affixed to the inside surfaces of the upturned ends .of screed plate 40. These angle members are positioned so that side plate 46 is positioned inwardly of the outer edge of the screed plate. Similarly, the adjoining side plate 46a of adjacent screed section 56 carrying the female connecting blocks is connected by machine screws to angle members 104, 105 which are in turn connected to the upturned ends of screed plate 40a. Shims 106, 107, between angle members 104, 105 and the side plate 46a; position such side plate so that its outer surface is in vertical alignment with the outer edge of screed plate 40a of such section. Thus, when the male and female connecting blocks of the adjacent screed sections are interengaged, the outer edges of the screed plates of such sections will actually or at least very nearly abut one another.

Preferably main screed section 18 carries a pair of forwardly tapering male connecting members 64, 64a on both of its opposite side plates 46 as shown in FIG. 3, or alternatively a pair of forwardly opening female members on both of its opposite side plates. In this way the forward driving force of the main screed will interact with the rearward driving forces of the extension sections to drive the connecting members of the main and extension sections into firm interlocking engagement with one another. However, if one of the above suggested arrangements is used, the extension sections on the opposite sides of the main screed sections cannot be interchanged without reversing the opposite side plates of each extension section for proper correlation of the connector members.

However, this can be done with minimum of difficulty because of the general identity and symmetry of the various side plates 46 except for the connector members thereof.

If the main screed section 18 carries male connecting members on its left-hand side plate, as viewed in FIG. 5, and female connecting blocks on its opposite side plate, and if each screed extension section similarly carries male blocks on its left-hand side plate and female blocks on its opposite side plate, the various screed extension sections will be interchangeable on either the right or the lefthand side of the machine without any modification of the sections. Also, if the foregoing arrangement were reversed, the same would be true. However, with such an arrangement the extension sections on one side of the main screed would tend to pull away from the main screed during forward movement of the machine.

Furthermore, the female blocks could open in either a forward or a rearward direction, in which case the male blocks on the adjoining side plates would have to be positioned accordingly. It is also possible to provide each side plate with one male and one female block if desired,

Having illustrated and described a preferred embodiment of my invention, it should be apparent to those having skill in the art that the same permits of modification in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of the following claims.

I claim:

1. A connection device for connecting together screed sections of a paving machine so as to extend the effective working width of the machine, each of said screed sections including a bottom screed plate and opposite side wall portions adjoining side by side relationship a corresponding side wall portion of a laterally adjacent screed section, said conection device comprising:

a female connecting member on one side wall portion of one said screed section,

a male connecting member on an adjacent side wall portion of another screed section to be joined to said one screed section,

said male member being complementary in shape to said female member,

said male and female members being slidably interengageable through fore and aft movement of their respective screed sections relative to one another.

2. A device according to claim 1 including interlocking means on said male and female members preventing separation of the connected screed sections when said members are interengaged.

3. A device according to claim 1 including means on at least one of said male and female members limiting the extent of slidably interengaging movement of said male member inwardly of said female member.

4. A device according to claim 2 including means on at least one of said male and female members limiting the extent of slidably interengaging movement of said male member inwardly of said female member.

5. A device according to claim 1 wherein there are two of said female connecting members on one said side wall portion and two corresponding male members on the adjoining said side wall portion, with said male and female members respectively being longtiudinally spaced apart in the direction of travel of said machine near the opposite ends of their respective screed sections.

6. A device according to claim 1 wherein one side wall portion of each screed section is provided with said female member and the opposite side wall portion of the same screed section is provided with said male member.

7. A device according to claim 1 wherein said female member is of generally U-shape as viewed in plan with a recess defined by the U opening in a forward or rearward direction when the associated screed section is operably connected to said machine.

8. A device according to claim 7 wherein said recess is generally wedge-shaped in plan and the cooperative said male member has a complementary wedge shape for sliding interengagement within the recess of said female memher.

9. A device according to claim 2 wherein said interlocking means includes a dovetail bevel on cooperative surfaces of said male and female members.

10. A device according to claim 7 wherein the U- shaped female member includes a pair of leg portions and wherein said interlocking means includes a dovetail bevel on an inner recess-defining surface of at least one of said leg portions slidably engageable with a corresponding dovetail beveled outer edge surface of said male member.

11. A device according to claim 1 including stop means on at least one of said two adjoining screed sections operable upon interengagement of said male and female members for preventing relative fore and aft movement of said screed sections relative to one another during travel of said machine.

12. A screed section for a paving machine,

said section being of a generally hollow box-like construction having:

an upstanding front wall portion,

a bottom screed plate,

an upstanding rear wall portion,

and a pair of upstanding opposite side plates,

a female connecting block on one of said opposite side plates,

a male connecting block on the opposite said side plate,

said female connecting block being generally of U-shape as viewed in plan and defining either a forwardly or a rearwardly opening recess in the operative position of said screed plate.

13. A screed section according to claim 12 wherein said male connecting block has at least one wedging surface for cooperation with a corresponding wedging surface of a female connecting block on an adjoining screed section.

14. A screed section according to claim 13 wherein said female connecting block has at least one wedging surface for cooperation with a corresponding wedging surface 'on a male connecting block on an adjoining screed section.

15. A screed section according to claim 12 wherein said male and female connecting blocks each have a dovetail beveled surface for interlocking engagement with a corresponding surface of a connecting block on an adjoining screed section.

16. A connection device for connecting together a pair of screed sections on a paving machine, said device comprising,

a generally U-shaped block member having a base portion and a pair of legs extending unidirectionally from opposite ends of said base portion, so as to define a recess between said legs,

each said leg having opposed face surfaces and an inwardly directed fiat edge surface diverging from the corresponding surface of the opposite said leg in a direction outwardly of said base portion,

said inwardly directed edge surfaces of said legs being beveled in a direction extending from one face surface to the other face surface.

17. A connection device according to claim 16 including a second block member for cooperation with said U- shaped member,

said second block member being generally wedge shaped and including a pair of opposed broad face surfaces and a pair of fiat opposite side edge surfaces converging toward one another so as to define wedging surfaces,

said wedging surfaces being beveled in a direction extending from one face surface to the other of said second block member,

the size and shape of said second block member being complementary to the size and shape of said recess defined by said first block member whereby said second block member is slidably interengageable within the recess of said first bolck member and inseparable from said first block member when thus interengaged in one direction normal to the direction of sliding interengagement.

References Cited UNITED STATES PATENTS 1,995,450 3/1935 French 94-45 2,002,661 5/1935 French 94-45 3,155,021 11/1964 Sauer 94-45 3,309,971 3/1967 Domenighetti 94-45 NILE C. BYERS, 111., Primary Examiner.

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