VARIABLE WIDTH MATERIAL DISTRIBUTION SYSTEM FOR ASPHALT PAVERS AND THE LIKE

Abstract: An asphalt paver, of the type having a power extendable floating screed, is provided with a power extendable auger-like material distribution mechanism (50,51), such that the width of the distribution mechanism can be varied with the width of the screed.

Description: This invention relates to an auger-like material distribution device for asphalt pavers and the like in which the auger-shaft includes an inboard section provided with an auger consisting of permanently mounted deflector plate means said auger-shaft also includes a telescoping outboard section which is axially adjustable with respect to the inboard section, as described in DE-B-1163356. In the laying of asphalt pavement roadways, for example, it is common to utilize floating screed type pavers. In pavers of this type, a paver tractor is advanced along the roadbed, typically pushing ahead of it a truck containing a supply of hot asphalt. The hot asphalt material is conveyed to the back of the paver, by internal conveyor means, and deposited in front of the floating screed. The paving material is distributed in front of the screed, and then leveled and smoothed by the advancing screed, as it travels over the just deposited asphalt material. In as much as the internal conveyor means of the paver is typically narrower in width than the screed, conventional floating screed pavers are provided with transversely disposed rotating auger-like distribution means, positioned directly in front of the screed. The auger-like means serve to move the deposited asphalt material laterally, and to distribute it with some degree of uniformity in front of the advancing screed. Ideally, the transverse width of the auger-like means is approximately the same as the width of the screed, in order to assure distribution of the paving material to the extremities of the screed. In order to accommodate laying of pavement mats of different width, the design of conventional paving machines typically has provided for the use of extension attachments for both the screed and auger facilities. Thus, for the over-the-road travel, either self-powered or by truck, the paver is configured for minimum width. At the job site, extension attachments are mounted to the screed and to the auger-like distributor, to increase the paving width of the machine to meet the demands of the job. It has been known heretofore to construct a floating screed paver with a power extendable/retractable screed arrangement, enabling the operator of the paver to vary the effective width of the screed at any time, even while the paver is in motion and in operation. Originally, such power variable screed arrangements were utilized primarily in connection with special paving jobs, such as driveways, parking lots, etc. where considerable width variability might be expected. Increasingly, however, paving contractors are preferring power variable screed constructions even for extended highway paving, where there may be minimum variability in the width of the paving mat. Such power variable screed facilities provide the contractor with a great degree of flexibility, and also can result in considerable saving of set-up and knockdown time at the beginning and end of paving operations. An advantageous form of such power variable screed for an asphalt paver is described in U.S. Patent No. 4,379,653. One of the shortcomings of asphalt paving equipment utilizing any of the existing power variable screed arrangements is that the auger-like mechanisms, utilized for distributing the paving material across the full width of the screed, do not vary along with the adjustments in screed width. This can cause problems in the uniformity of the pavement mat, particularly near the outer extremities of an extended screed. One attempt to overcome problems of this type is reflected in the Fisher et al. United States Patent No. 3,907,451, in which auger devices are mounted directly on a movable strike-off element such that, when the strike-off element is moved in a laterally outward direction, it carries the auger mechanism with it. This does little to solve the material distribution problem, however, because moving the augers in an outward direction leaves an area in the center, where the bulk of the material is being deposited, without means to move it laterally outward. Further, the mounting of an auger on a screed or strike-off element serves to impose widely varying reaction forces on the screed or strike-off element, which can have the effect to introducing undesirable variations in the finish of the pavement mat. Pursuant to the present invention, the outboard section is provided with an auger consisting of permanently mounted deflector plate means which are shaped and sized to pass between or inter fit with said deflector plate means of the inboard section when said inboard and outboard sections are retracted to shorten the length of said auger-shaft, said deflector plate means of each telescoping outboard section thus being so related to the deflector plate means of an adjacent inboard section as to provide a lateral material distribution deflector plate configuration which is infinitely adjustable between the extended and retracted positions of said inboard and outboard sections. The new arrangement represents a vast improvement in existing asphalt pavers with power variable screeds, in that under all conditions it is assured that there will be an effective distribution of the paving material laterally in front of the extended screed. To advantage, the power extendable material distribution mechanism of the invention is mounted and supported on the paver tractor, independently of the floating screed, so that the action of the screed is not affected by the variable reaction forces typically acting upon the distribution mechanism. In a highly advantageous form, the power extendable distributor arrangement of the invention is comprised of telescopically associated augerlike sections, each containing a plurality of paddle-like deflector plate segments arranged to an angle to the rotational axis of the auger mechanism. When the mechanism is in its fully condensed or retracted position, the various deflector segments optimally may be aligned to form a more or less continuous helix, although that is not necessary to the invention. When extended or partially extended, the deflector segments are distributed over the full length of the device and act with a high degree of effectiveness on the deposited paving material to provide a desired degree of uniformity in the distribution thereof out to the farthest reaches of the extended screed. Among other features of the invention, the power variable auger-like distributor mechanism of the invention is designed to be suitable for operation in the extremely hostile environment, such as that represented by hot asphalt material, in which the distributor mechanism is immersed or partially immersed during normal operations. Initially, the asphalt material is hot and plastic, but it accumulates and hardnes over time, such that any mechanism operating in its environment must be rugged and dependable in construction, and have a measure of self-cleaning action to minimize the likehood of the mechanism being "frozen" by congealed asphalt. As a subsidiary feature, the apparatus of the invention incorporates an advantageous form of telescoping material confinement panel structure, positioned in front of the telescoping distributor mechanism and extendable or retractable along with it. The confinement panel works in cooperation with the screed to confine the deposited paving material, but in front of and behind the distributor mechanism, over its adjustably extended length. In addition, the panel structure serves as an extendable guard, so that workmen are fully protected from accidental contact with the rotating distributor plates. It is also an object of the present invention to provide four quadrants of flighting to form a helical configuration which are removably secured to telescoping rails so that individual flight members or quadrants can be removed and replaced upon breakage without necessiting a substitution of an entire telescoping auger section. It is the further object of the present invention to provide paddle sections which are provided with rectangular channel connector castings which fit into square tube paddle carrying sections by a tongue and groove arrangement, and can be bolted thereto. It is still another feature of the present invention to provide replaceable paddle elements on telescoping auger sections, having fastening channels which are interconnected to other channel sections on a telescoping auger arrangement. Another object of the present invention is to provide an outer support bearing with a bearing housing which is located at the extreme outer end of the telescoping auger assembly, so that when the auger is fully extended it is not necessary to push the paving material laterally out past the bearing and its housing in order to get the full width paving mat. In the past, the regular auger had its outer bearing positioned about one foot inward from the extreme outer end. The present telescoping auger is especially advantageous when utilized with a power extendible screed so that the operator, during operation, can alter the paving width, as well as the configuration, as desired. There is no requirement that the operation of the paving apparatus be halted while the operator makes changes or adjustments to either or both the auger and the screed. For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments and to the accompanying drawing. Fig.1 is a side elevational view of a typical form of floating screed asphalt paver incorporating a power extendable material distributor mechanism according to the invention. Fig. 2 is an enlarged view illustrating features of construction of the new power extendable distributor mechanism, showing the mechanism in a fully extended condition. Fig. 3 is an enlarged, fragmentary, exploded view of the distributor mechanism of Fig. 2, illustrating the manner in which the respective sections thereof are telescopically assembled. Figs. 4 and 5 are end elevational views of the respective parts illustrated in the perspective view of Fig. 3. Fig. 6 is a cross sectional view taken on line 6-6 of Fig. 2, illustrating the parts of Figs. 4 and 5 in an assembled condition. Fig. 7 is a cross sectional view as taken generally on line 7-7 of Fig. 2. Fig. 8 is a fragmentary perspective view of a telescoping confinement panel structure for use in connection with the telescoping distributor arrangement. Fig. 9 is an enlarged cross sectional view as taken generally on line 9-9 of Fig. 8. Fig. 10 is a front elevational view of the telescoping panel arrangement, illustrating the confinement panel in its fully retracted condition. Fig. 11 is an enlarged, fragmentary cross sectional view of a modified form of power extendable distributor arrangment suitable for use in the paver of Fig. 1. Figs. 12-14 are illustrations of a second modified form of power extendable distributor structure incorporating principles of the invention, Figs. 12 and 14 illustrating the mechanism in extended and retracted positions respectively, and Fig. 13 representing a cross sectional view taken generally on line 13-13 of Fig. 12. Figs. 15-17 are illustrations of a still further modified form of telescoping, power extendable distributor arrangement, with Figs. 15 and 17 showing the distributor in extended and retracted conditions respectively, and Fig. 16 representing an end elevational view thereof Figs. 18 and 19 are illustrations of a still further modified form of power extendable distributor mechanism according to the invention, illustrating the distributor mechanism in extended and retracted conditions respectively. Fig. 20 is an enlarged cross sectional view showing a further embodiment of an extendible distributor mechanism for a paving machine. Fig. 21 is a fragmentary view of the distributor mechanism shown in Fig. 20 in which the respective inboard and outboard sections are telescopically assembled. Fig. 22 is an end elevational view showing a distributor mechanism for a paving machine. Fig. 23 is a sectional view in enlarged form taken along the lines 23-23 of Fig. 22. Fig. 24 is a partial sectional and a partial elevational view of a deflector plate of the power extendible distributor mechanism showing the tongue and groove bolt-on casting for removably affixing a deflector plate to a central drive mechanism. Fig. 25 is a view taken along the lines 25-25 of Fig. 24 Fig. 26 is a view taken along the lines 26-26 of Fig. 24, and Fig. 27 is a front elevational view of a left hand paddle showing the channel-shaped casting for removable attachment to a central drive shaft. Referring now to the drawings, and initially to Figs. 1-10 thereof, the reference numeral 10 designates generally a typical form of floating screed type asphalt paver in which the features of the invention are incorporated. The paver is self-powered by an engine 11 and has at its' forward end a load carrying hopper 12 for receiving hot asphalt paving material from a dump truck positioned directly in front of the paver. In typical operation, the paver pushes the truck along the roadbed, with the truck continually discharging material into the hopper 12. When the truck is emptied, the paver continues paving, using the reserve of material contained in the hopper 12,while the new truck is brought into position in front of the paver. A conventional paver includes internal conveyor means (not shown)which convey the hot asphalt material rearward, deposting it at the back of the paver tractor, as indicated at 13. In the illustrated paver apparatus, a power extendable screed 14, comprising a center screed section 15 and opposite side, laterally extendable screed elements 16, is attached to the paver tractor by means of tow arms 17 at each side. The tow arms 17 are attached to the paver at tow points 18, which are vertically adjustable such that the angle of attack of the floating screed assembly 14 may be controllably varied during paving to maintain a level paving surface. The power extendable screed structure may be in accordance with the before mentioned Brown U.S. Patent No. 4,379,653. Directly in front of the screed assembly 14 is an auger-like material distributor mechanism, generally designated by the reference numeral 19 and to be described in greater detail. Asphalt material deposited by the conveyor means accumulates in a pile in front of the screed, in a relatively narrow area determined by the width of the conveyor means. The distributor mechanism 19 conventionally is in the form of a rotating auger-like device, which serves to distribute the paving material 13 laterally outward toward the end extremities of the screed. Conventionally, a paver includes left and right side distributors, arranged to distribute the paving material outward in both diretions from the center of the paving machine. In accordance with the present invention, the opposite side distributor mechanisms 19 are telescopically extendable laterally such that, during paving, the length of the distributors may at all times properly correspond with the extended width of the screed 14. Referring now to Figs. 2-7, there are shown details of construction of a power extendable distributor mechanism used in the paver apparatus of Fig. 1. As shown in Fig. 2, left and right side distributor assemblies 19a, 19b are supported and driven, preferrably at the inboard ends, by means of a drive box 20, which is attached to and forms part of the paver tractor. Internally, the drive box 20 includes drive means, typically chains and sprockets etc., for rotating the respective distributor shafts 21, 22, either independently or in unison, depending upon the control facilities provided. In the drawings, details are shown of only the left-hand distributor assembly 19a, it being understood, of course, that the complementary, right side distributor is similarly constructed. Support for the outboard end of the distributor 19a is provided by a bearing 23 carried by a vertically adjustable bearing bracket 24 rigidly attached to an outboard support arm 25. The outboard support arm is itself supported by a relatively large diameter, telescoping tube assembly, generally designated by the reference numeral 26, which in the illustrated apparatus comprises three telescoping tubes, 27, 28 and 29. The inboard tube 29 is mounted at its inner end adjacent the drive box 20 and is supported outboard of the drive box by means of a frame plate 30 forming part of the paver tractor frame. The structure of the telescoping tubes is shown in more detail in Fig. 10. The inboard tube 29 is shown to have an internal collar 31 secured to its open end, by means of an attached flange 32 bolted to a second flange 33 carried at the end of the tube 29. The internal sleeve 31 serves as a slide bearing for the intermediate tube 28, which carries an external sleeve 34 at its inboard end. The sleeve 34 serves as a bearing engaging the internal wall of the inboard tube 29. In the illustration of Fig. 10, considerable clearances are shown between the walls of the telescoping tubes and the bearing sleeves, in order to simplify understanding of the drawings. In actual practice, all of these parts will be constructed to have a relatively close sliding fit. As will be evident in Fig. 10, the respective bearing sleeves 31, 34 will abut against each other when the intermediate tube 28 is extended telescopically to a predetermined limit position. The intermediate tube 28 is similarly provided at its outboard end with an internal bearing sleeve 35 slideably supporting the outboard tube 27. The latter, at its inboard end, is provided with an external bearing sleeve 36. The respective bearing sleeves 35, 36 function in the same manner as the bearing sleeves 31, 34, providing for a close sliding fit of the telescoping tubes 27, 28 and also serving to provide a limit stop for telescoping extension of the outboard tube 27. Controlled extension and retraction of the telescoping support 26 is provided by means of a controllable hydraulic cylinder 37 anchored at its inboard end 38 and having an extendable actuator rod 39. The outer end of the actuating rod 39 is attached to the outboard support plate 25, desirably in straddling relation to the adjustable bearing support 24, so as to be substantially aligned therewith. To this end, the actuating rod 39 is attached to a bracket 40, which is bolted to the support plate 25 by a plurality of spacer bolts 41, arranged to straddle the bearing support 24. In one particularly preferred embodiment of the invention, the rotating distributor mechanism 19a includes inboard and outboard telescopically arranged distributor sections 50, 51. The inboard distributor section 50 (see Figs. 3 and 4) comprises a series of three "square" tubular structural elements 52-54 arranged in side by side relation and secured together by linear welds 55 to form a unitary structure. At its inboard end, this assembly is attached to a drive coupling 56, through which the distributor section is driven from the drive box 20. Mounted on the outer tube members 52, 54 are a series of deflector plates or paddles 57, alternate ones of which are positioned in staggered relation along the length of the inboard section, rotationally displaced by 180°. These deflector plates are secured to the tube members 52, 54 by welding, as at 58, and typically are in the form of a segment of a disc or circle, covering an angle of approximately 90°. As reflected in Figs. 3 and 4, the inner portions of the disc segments are removed and notches 59 are formed in the radially inner portions of the disc segments, such that the structural tube members 52, 54 are partly received therein, providing a highly secure mounting for the deflector plates. When assembled, the deflector segments form diametrically opposed 90° segments of a circular structure, the center of which is coincident with the axis of the center tube member 53, which is also the rotational axis of the distributor assembly. Extending lengthwise along the inboard distributor section 50, over approximately the outer half thereof, are four drive rails 60 of a triangular cross sectional configuration. One side of the drive rails is seated against a flat supporting surface 61 formed by the deflector segments 57, and the drive rails are secured to the deflector segments as well as to the respective tube members 52, 54 by welding. Each of the drive rails 60 has a radially inwardly facing drive surface 62, and these surfaces, on adjacent drive rails, form a dovetail-like slot arrangement. As shown in Figs. 3 and 5, the outboard distributor section 51 comprises a spaced pair of "square" tubular structural members 63, 64 joined together at their outboard ends by an end cap structure 65. A "square" shaft 66 is secured at its outboard end to the end cap 65 and extends inward, between and in parallel relation to the tubular members 63, 64. The corners of the square shaft 66 have been removed, and the dimensions of the bar are otherwise suitable to be closely received within the interior of the central tubular member 53 of the inboard distributor section 50. The outboard tubular structural members 63, 64 mount deflector plates 67, which are generally similar to the deflector plates 57 of the inboard distributor section, and are mounted on the tubular members 63, 64 in the same manner as the deflector plates 57 and secured by welding. Pairs of triangular drive rails 68 are welded to the tubular members 63, 64 and extend lengthwise thereof over approximately the inner half of the tubular members (see Fig. 2). The orientation of the drive bar 68 is such that the diagonal surfaces 69 thereof face generally radially outward from the central axis, with adjacent pairs of the drive rails being in the form of dovetail-like elements complementary to the dovetail-like elements formed by adjacent pairs of the drive rails 60. When the respective inboard and outboard distributor sections are telescopically assembled, the central drive shaft 66 is received internally of the central tube member 53, and the spaced apart tube members 63, 64 of the outboard unit straddle the central tubular member 53 of the inboard unit. As reflected in Fig. 6, the inwardly facing drive rails 60 interfit with the outwardly facing drive rails 68, so that their respective diagonal surfaces are in facing/contacting relation. Because of the dovetail-like configuration, the inwardly facing drive rails serve to confine the outwardly facing drive rails, and thus position and confine the spaced tubular members 63, 64 which are otherwise secured only at their outer end extremities, by the cap member 65. As is reflected in Fig. 6, the respective inboard and outboard distributor sections mount their opposed sets of deflector plates 57, 67 with a 90° rotational displacement, such that the deflector plates of one section can be received within the open spaces provided by the deflector plates of the other section. Optimally, the sets of deflector plates can be so positioned and arranged on the respective distributor sections that, when the respective inboard and outboard sections are telescoped to a fully retracted or closed condition, the deflector plates generally align themselves in sequence to form a substantially continuous helix. It is by no means necessary to the invention, however, that the plates align themselves in any position to form a substantially continuous helix. To advantage, the respective deflector plates are arranged to provide some degree of clearance space 70 between adjacent deflector edges, whenever two plates are aligned, in order to facilitate one plate passing the other properly during telescopic extending and retracting movements. As reflected in Fig. 2, the inboard distributor section 50 will, in normal operations of the paver, be driven through the inboard drive cap 56, from the main drive box 20. The rotational motion of the inboard section is transmitted to the outboard section, in any operative position of extension or retraction, in part through the central drive shaft 66 and in part through the pairs of drive rails 60, 68. The central drive shaft 66, transmits torque to the outboard end cap 65, and the cap imparts rotational motion to the outer ends of the outboard tubular structural members 63, 64. Torque is also imparted to the inner portions of the tubular members 63, 64 through the action of the drive rails 60, 68, which cause the otherwise free ends of the tubular members 63, 64 to be confined by and rotationally carried with the tubular members 52-54 of the inboard distributor section. Thus, in any extended or retracted position of the outboard distributor section 51, the latter is driven not only at its outboard extremity, but also over some extended inboard portion, depending upon the degree and location of overlap between the respective sets of drive rails 60, 68. In general, there is no significant advantage in extending the drive rails over the full length of the respective auger sections. There should be at least several inches of overlap of the rails when the outboard auger section is fully extended, as in the position shown in Fig. 2. It is thus adequate for a similar degree of overlap to be provided when the outboard section is fully retracted. If desired, however, the inboard rail sections 60 may be extended inward further, to provide better confinement of the otherwise free ends of the tubular structural members 63, 64. Adjustable positioning of the outboard distributor section 51 is accomplished, even during power operation of the distributor, by simply extending or retracting the fluid actuator 37. This serves to extend the outboard distributor section as well as the telescoping tubular support 26, which carries the outboard bearing bracket 24. Typically, separate left side and right side controls will be provided for the opposite side material distributors. These may be operated in unison with or independently of the power extension means for the screed sections 16. Normally, the distributors will be extended or retracted along with the screed extensions 16, but it may be desirable to provide for independent controls so that distributor extension, in relation to screed extension, may be an additional control variable available to the paver operator. As will be readily appreciated, when the outboard distributor section is extended, there is somewhat less continuity of the deflector plates with the deposited paving material. If necessary or desirable, the rotational speed of the distributor can be varied as a function of its length. Quite typically, however, rotational speed of the distributor is a function of the height of the paving material at or near the outboard end, under the control of a position sensing switch, such that any adjustment in rotational speed is automatically accommodated by the switch itself. In a typical asphalt paving apparatus, it is advantageous to provide a confinement structure directly in front of the auger-like material distributor devices. The deposited paving material is thus confined in front and behind the auger-like distributor, by means of the panel structure, in front, and the floating screed, in back. In accordance with one aspect of the present invention, a confinement panel structure is provided which extends or retracts along with the material distributor mechanism, such that the paving material is properly confined in any extended or retracted position of the distributor. To particular advantage, the extendable confinement panel structure is mounted on the same telescoping support arrangement that carries the outboard bearing bracket for the extendable distributor mechanism. As will be understood, the extendable confinement panel also serves to provide a safety guard for the front side of the rotating distributor mechanism. With reference now particularly to Figs. 1, 2 and 7-10, the variable width confinement panel structure includes outboard, intermediate and inboard confinement panels 100-102, which are carried respectively by the outboard, intermediate inboard telescoping tubes 27-29. The inboard guard panel 102 may be welded across its full top width to the inboard support tube 29 and extends over the exposed outer portion of that tube, from the frame plate 30 to the end flange 32. The lower edge of the panel 102 is bent upward, at 103, to stiffen the panel and to provide a confining channel area 104 (see Fig. 9) for an adjacent panel. Along the inner edge of the confinement panel 102 there is welded a stiffening plate 105, which may be bolted or otherwise secured to the tractor frame plate 30 to rigidfy the structure. The flange 33, welded at the outer end of the inboard support tube 29 is provided with a downwardly extending portion 106 (see Fig. 8) providing means for guiding and supporting portions of the adjacent, intermediate panel 101. Pursuant to the invention, the intermedite panel 101 is secured to the intermediate support tube 28 is only by a narrow neck portion 107 adjacent the outer edge of the panel. The inboard portions of the intermediate panel, along its entire upper edge 108 up the neck portion 107, are recessed as shown in Fig. 8 to provide a clearance underneath the larger diameter inboard support tube 29. A flange 109, welded to the outer extemity to the intermediate support tube 28, has a portion 110 extending vertically downward for the full height of the intermediate panel. The flange portion 110 is joined with the intermediate panel only in a short region 111 adjacent the neck 107, and again along a narrow area 112 where the lower edge extremity 113 of the intermediate panel is bent upward. Between these two extremities, where the panel 101 is welded to the stiffening flange 110, the latter is recessed (as at 114 in Fig. 9) to slideably receive and guide the outboard panel 100. The outboard confinement panel is secured only along its outboard vertical edge, where it is welded to a downward extension 115 of the outboard support arm 125. In the illustrated arrangement, the lower edge extremity 116 of the outboard panel is folded over flat against the main surface of the panel forming a stiffening rib, which is received in an enlargement 117 of the recess 114 in the outer arm extension 115. As reflected particularly in Figs. 8 and 9, the bent-around lower end portions 103, 113 and 116 of the respective confinement panels 102, 101, 100 serve dual purposes. First, they stiffen and strengthen the lower end portions of the panels. Second, each provides a guide and confinement for the other to accommodate telescoping extending and retracting movements. Thus, the free lower portion of the intermediate panel 101 is confined by the cooperative relationship between the upwardly bent lip portions 103, 113. The otherwise free inner portion of the outboard panel 100 is guided and confined by the upwardly bent portion 113. The folded-over portion 116 of the outboard panel serves to provide an increased bearing area and also provides structural stiffening. To guide and confine the free upper, inboard portion of the intermediate panel 101, an arrangement of guide bars is provided, which is shown particularly in Figs. 8 and 9. These are shown in the illustration with substantial clearance, in order to facilitate an understanding of the structure. In the actual device the parts will be constructed to provide reasonably close sliding fits. Welded to the inboard support tube 29 is a first guide housing plate 120, which is welded along its top edge to the tube 29 and along its outboard edge to the support flange 106. The housing plate 120 is parallel to but spaced forward of the fixed, inboard confinement plate 102. Welded to the lower margin of the housing plate 120, along its inside lower edge, is a guide bar 121. An intermediate guide bar 122 is welded to the intermediate guard plate 101 through an interposed spacer bar 123 which in turn is welded directly to the surface of the intermediate panel. As shown in Fig. 9, the upper portion of the intermediate panel 101 is confined on the back side by the fixed inboard panel and on the front side by the cooperating of the front surface of the guide bar 122 with the back surface of the housing plate 120. The confronting surfaces of the respective guide bars 121, 122 serve to provide vertical support for the intermediate plate. As shown in Fig. 9, the guide bar 122 extends downward, substantially below the lower edge of the spacer bar 123, providing a downwardly opening guide slot 124 adapted to receive the upper edge margin of the outboard confinement panel 100. The extendable confinement panel structure is shown in Fig. 8 in a fully extended condition and in Fig. 10 in a fully retracted condition. The construction of the extendable panel is simple and effective, yet extremely rugged and suitable for the heavy duty service to which equipment of this type is subjected. It is not intended, of course, that the extendable confinement panel structure function as a screed or strike-off, but it nevertheless must be capable of withstanding relatively severe abuse because of the nature of the intended service. In the illustrated form of the invention, the extendable confinement panel is effectively an integral part of the power extendable distributor structure. However, it will be understood that, if appropriate, the power extendable panel arrangement might be utilized to advantage even with a conventional paver device such as the type utilizing movable auger means mounted on a variable width strike-off, for example, or even for use where bolt-on auger extensions are used. In either case, the use of a power extendable confinement panel would minimize opportunities for job-site workmen to create an unsuitable operating condition by reason of their failure to bolt on a panel extension, for example, when attaching a distributor extension. In a modification of the power extendable material distributor mechanism of the invention, shown in Fig. 11 of the drawing, the inboard and outboard auger-like distributor sections are constructed with a different form of drive rail configuration. In the Fig. 11 version, the inboard section includes three structural tubular members 152-154 welded together in a common plane and otherwise constructed in a manner similar to the inboard distributor section 50 previously described. In place of the drive rails 60 or triangular cross sectional configuration, however, the Fig. 11 modification employs a simple guide bar 200 on the forward-rotating side of each of the tubular members 152, 154, and an L-shaped guide bar 201 on the trailing side of those tubular members (assuming a clockwise direction of rotation as viewed in Fig. 11). The outboard distributor section 151 comprises a spaced pair of tubular structural members 163, 164 corresponding generally to the members 63, 64 of the first described embodiment. In place of the drive rails 68 of triangular configuration, however, the tubular members 163, 164 have welded to their inside surfaces elongated drive plates 203 which extend lengthwise of the distributor section and have leading and trailing edge margins 204, 205 projecting laterally beyond the side edges of the tubular members. When the distributor structure of Fig. 11 is rotated in a clockwise direction, the tubular members 152, 154 of the driven inboard section will "push" against the plate margins 205, while the L-shaped drive rails 201 will "pull" on the exposed plate margins 204, to impart the necessary drive torque to the inboard portions of the outer auger section. The outer extremity of the outboard section is of course driven by means of the central "square" bar 166 in the same manner as the previously described embodiment. The drive rail arrangement of the Fig. 11 embodiment is somewhat simpler and less expensive to construct that the arrangement of the principal described embodiment, although the latter is perhaps functionally superior. In the modifications of Figs. 12-14, a power extendable distributor arrangement is provided in which deflector plates cover an arcuate segment of approximately 180°. Accordingly, all of the segments of one orientation are mounted on the outboard distributor section, while all of the plates of the opposite orientation are mounted on the inboard distributor section. An end cap structure 300 is provided, having a shaft projection 301 for attachment to the drive box mechanism 20 of the paver. From one side of the inboard end cap 300 projects an internal bar or shaft 302 while on the opposite side of the axis there extends a hollow tubular member 303. The outboard distributor section 351 is substantially a mirror image of the inboard section 350, having an outboard end cap 304 mounting in parallel relation a bar or shaft 305 and a tubular structural member 306. A shaft projection 307 is arranged for reception in the outboard bearing member of the basic apparatus as heretofore described. Each of the bar members 302, 305 is telescopically received within the tubular member 306, 303 of the opposite distributor section. Welded or otherwise secured to the respective tubular members 303, 306 are a series of semicircular helical segments 308 which, in the illustrated arrangement, are provided with spacer sleeves 309. Thus, depending on the overall length of the respective distributor sections, a plurality of semicircular paddle-like deflector segments may be welded along the length of the tubular members to provide "semi helix". In the position of full retraction of the distributor mechanism, as shown in Fig. 14, the structure is substantially equivalent to a conventional auger, with helix-like material deflector means. In the fully extended position, shown in Fig. 12, the half sections are functional at the inboard and outboard extremes, and there typically is some overlap of auger segments in the intermediate section. In the further modification of Figs. 15-17, there is shown a form of telescopically extendable distributor in which the individual deflector plate segments 405-409 are of semicircular projected configuration (Fig. 16) and in which each of several telescoping segments 401-404 contains two such 180° segments, one disposed at a relatively large acute angle to the shaft axis, and the other being disposed at a relatively smaller acute angle. The arrangement is such that, when the telescoping sections are extended, there is functional overlap between adjacent 180° sections that are disposed at the smaller angle to the auger axis. By functional overlap, it is meant that the auger segments are either physically overlapped as shown in Fig. 15, or if not physically overlapped, at least sufficiently close together that paving material is transferred from one auger section to the next and thus is effectively continuously advanced outwardly by rotation of the auger mechanism. In the modification of Fig. 15, the large angle/small angle arrangement of each pair is alternated in successive telescoping sections. Accordingly, when the structure is partially or fully retracted, the low angle, 180° segments can pass each other without interfering. A condition of full retraction is achieved when the large angle segment of one telescoping section approaches the low angle segment of the adjacent telescoping section, substantially as reflected in Fig. 17. In the modification of Figs. 18 and 19, continuous helix sections 501 are provided which, in the extended configuration of the distributor mechanism, form a continuous or almost continuous helix. In the condensed or retracted configuration of the distributor, each of a plurality of distributor sections 502 is spirally retracted upon an adjacent section, providing a generally continuous helix of double thickness, as shown in Fig. 18. To this end, each of the illustrated distributor segments 501 consists of approximately 720° of spiral. The middle 360° portion is secured, as by welding, to a tubular sleeve section 503, while a 180° portion 504 on each end is supported in cantilever fashion. Each segment has a shaft portion 504, which telescopes into the adjacent tubular section 503. When the assembly is retracted, the adjacent sections are rotated and telescopically condensed with a helical movement. The cantilever supported helix sections slide one behind the other and "wind" themselves over the adjacent tubular sections 502. Referring to Figs. 20-27, there are shown details of construction of a power extendible distributor mechanism used in a paver of the type illustrated in Fig. 1, and described hereinbefore. As seen in Figs. 20-23, the rotating distributor mechanism referred to generally by the numeral 620 includes inboard and outboard telescoping distributor sections referred to generally by the numerals 622 and 624, respectively. The inboard distributor section 622 comprises a series of three rectangular-shaped structural members 626, 628 and 630 arranged in side by side relation and secured together by welds to form a unitary structure. At its inboard end this assembly is attached to a drive mechanism (not shown) through which the inboard section is rotated. Mounted on outer tubular members 626 and 630 are reflector plates of paddles 632, 634, respectively. It should be evident that the plate 632, 634 is a full length auger paddle while plate 635 is a kickback paddle. The paddles 632, 634 are positioned in staggered relation along the length of the inboard section and rotationally displaced by 180° degrees, thus, when assembled, the deflector plates formed diametrically opposed 90 degree segments of a circular structure, the center of which is coincident with the axis of the center tube member 628, which is also the rotational axis of the distributor assembly. As seen in Figs. 20-23, the outboard distributor section 624 comprises tubular structural members 636 and 638 welded or otherwise secured to an end plate (not shown) and to a shaft 629 which telescopes within center tube member 628 in a plane at right angles to the mounting plane of tubular members 626 and 630. A cover shield 654 is shown in Figs. 22 and 23 for the inner bearing assembly 655. The tubular structural members 636 and 638 slide along tube 628 in order to assume an extended position but are not attached to tube 628. Consequently, the outboard distributor section, when extended, is cantilevered with respect to the inboard distributor section 622. The outboard tubular structural members 636 and 638 mount the deflector plates or paddles 640 and 642, respectively, which are generally similar to the deflector plates 632, 634 of the inboard distribution section, except that deflector plate 640 is the end paddle of the outer section, while deflector plate 642 is a full length auger paddle of the outer section. In Fig. 21 it will be noted that the end casting 647 is shorter than the other castings. However, there is no change in effect by using the shorter casting on the auger. It should be evident that the inboard and outboard distributor sections 622 and 624 have opposing deflector plates with a 90 degree rotational displacement so that the opposing deflector plates in one of the sections can be slid into and received in the open spaces 644 between opposing deflecting plates of the other section. When the outboard section 624 is fully retracted within the spaced deflecting plates of the inboard section, the auger configuration is that of a substantially continuous helix. As will be noted in Fig. 20, there is a clearance 644a between the adjacent edges of the deflector plates so that there is no interference between the deflector plates of the outboard and inboard sections 622 and 624, respectively, during outboard telescoping and inward retracting movements thereof. The deflector plates of both the inboard and outboard distributor sections 622 and 624 are provided with bolt-on castings 646 in the form of an inverted channel-shaped members, as clearly seen in Figs. 24-27 of the drawings. Castings 646 are provided with holes 648 in the front and rear thereof trough which bolts 650 can be inserted and nuts 652 affixed thereto, thus, removably securing each of the deflector plates to the respective tubular structural members adjacent thereto. Consequently, the inverted channel-shaped connecting members are interconnected to each other in a tongue and groove arrangement, as seen in Fig. 20. Thus, each of the channel-shaped connecting members are provided with an extension 646a which will push against flange 646b of the adjacent channel-shaped connecting member, while the other leg of each channel-shaped member is provided with a flange 646b which interconnects with the projection 646a of the adjacent channel-shaped member to form a tongue and groove interlocking construction about the entire assembly of tubular structural members. The tongue and groove arrangement also functions to assist in supporting any side loads exerted on the cantilevered portions of the two tubes 636 and 638 of the outboard distributor section 624. It should be apparent that upon breakage of any individual deflector plates or paddle, in the present material distribution assembly, and the same can be removed from the distribution assembly and replaced rapidly and effectively with another paddle or deflector plate segment. As seen in Figs. 24-27, the replaceable paddle or deflector plate are each provided with an inverted channel member having one leg provided with an extension 646a while the other leg is provided with a flange 646b. The inverted channel 646 is also provided with aligned holes 648 through which a bolt and nut attachment is made to the respective outer and inner distributor section, especially structural members 626 and 630, as well as structural members 636 and 638. A central drive shaft 629 of the inboard section 622 imparts rotational movement to the outboard section 624 in any extended or retracted position of the outboard section by means of the driving connection between the rotating drive shaft 629 which closely interfits within the center rectangular-shaped tube member 628. As a result a drive means (not shown) may rotate both inboard and outboard telescoping distributor sections in either extended or retracted modes. The apparatus of the invention represents a significant advance in the construction of material distributor mechanisms, for asphalt paving machines in particular, because of the active need and desirability for variable width paving and/or the need or desirability of power extendable/retractable paving equipment, giving the equipment the capability of occasional utilization for variable width paving requirements. Heretofore, variable width paving has been accomplished principally with the use of power extendable screed and strike-off arrangements. The previously known equipment, while far superior to conventional fixed width equipment, nevertheless has suffered from the disadvantage that the guard-like material distribution facility has not been extendable and retractable along with the screed. One previous attempt to deal with this shortcoming, the Fisher et al. U.S. Patent No. 3,907,451 falls far short of achieving such a purpose. First, there in fact is no provision for extending or retracting the auger-like distributor. Rather, the auger is merely repositioned so as to cooperate with the outboard areas of the screed or strike-off. This tends to satisfy one need at the expense of another (the center area). Additionally, the movable auger arrangement is mounted on the screed or strike-off itself, such that the significant and highly variable reaction forces on the auger are necessarily imparted to the screed, having a potentially undesirable effect upon the smoothness of the pavement mat. In the preferred form of the applicant's invention, the power extendable distributor mechanism is mounted directly by the paver tractor, and not by the screed. Thus, the screed is isolated from both the weight and the reaction forces of the auger. Additionally, separate mounting of the extendable distributor mechanism allows for independent control of distributor extension vis-a-vis screed extension, so that an additional control capability is available to the paver operator. In a highly advantageous form of the invention, a telescoping cantilever support structure, which provides outboard bearing support for the rotating, extendable material distribution device, also mounts a telescoping panel structure providing a material confinement means on the front side of the distributor. The panel structure is formed of a plurality of overlapping, flat panels, carried by the telescoping members of the bearing support and extendable and retractable along with the material distribution device. The structure of the invention greatly enhances the performance of paving equipment with power extendable screed facilities by assuring that the lateral distribution of paving material will always be properly related to the extended width of the screed. It should be understood of course that the specific form of the invention herein illustrated and described is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

Claims: An auger-like material distribution device for asphalt pavers and the like in which the auger-shaft includes an inboard section (50) provided with an auger consisting of permanently mounted deflector plate means (57) said auger-shaft also includes a telescoping outboard section (51) which is axially adjustable with respect to the inboard section, characterized in that the outboard section (51) is provided with an auger consisting of permanently mounted deflector plate means (67) which are shaped and sized to pass between or inter fit with said deflector plate means (57) of the inboard section (50) when said inboard and outboard sections are retracted to shorten the length of said auger-shaft, said deflector plate means (67) of each telescoping outboard section (51) thus being so related to the deflector plate means of an adjacent inboard section (50) as to provide a lateral material distribution deflector plate configuration which is infinitely adjustable between the extended and retracted positions of said inboard and outboard sections. Device according to claim 1, characterized by mounting means for rotatably mounting the inboard end of said inboard section (50), said outboard section (51) beign drivingly connected to said inboard section for rotation in unison, a telescoping cantilever bearing support means (26) extending laterally outward adjacent said material distribution sections, said bearing support means (26) including at least one telescopically extendable and retractable outboard part (27), bearing means (23) carried by said bearing support means (26) and rotatably supporting outer portions of said outboard section (51), controllable power means (37) for extending and retracting said outboard part (27) and said outboard section (51). Device according to claim 1 or 2, characterized in that one of the sections (50) comprises a series of three elongated tubular structural members (52, 53, 54) secured in side-by-side relation and supporting first deflector plate means (57) which are mounted on the radially outer ones of said structural members and extending over arcuate segments of not more than approximately 90°, the other section (51) comprising a central shaft (66),telescopically received within and drivingly engaged by the central structural member (53) the other section (51) further including a pair of spaced apart tubular structural members (63, 64) mounted in cantilever fashion to the outboard end of said central shaft (66) and positioned in closely straddling relation to said central structural member (53) between the first deflector plate means (57), second deflector plate means (67) being mounted on said spaced apart tubular structural members (63, 64), in the arcuate regions between the first deflector plate means to accommodate relative movement of the respective sets of deflector plate means, one past the other. Device according to any of claims 2-3, characterized by a telescopically extendable confinement panel structure mounted on the bearing support means (26) and being positioned in leading relation to the material distribution sections (50, 51) the panel structure comprising a plurality of overlapping slideably related panels (100, 101, 102) positioned adjacent the material distribution sections and extendable and retractable therewith. Device according to any of claims 3-4, characterized in that the drive means comprise pairs of elongated rail-like elements (60) mounted on the structural members (52, 54) of one section (50) for slideable engagement with cooperative elongated drive elements (68) mounted on the structural members (63, 64) of the other section (51). Device according to claim 5, characterized by adjacent pairs of said rail-like elements (60) forming dovetail-like connecting means for both driving and confining free end portions of said spaced structural members (63, 64). Device according to any of claims 1-6, characterized by said paving apparatus comprising a self-propelled tractor and a variable width floating screed (14), said material distribution device (19) being mounted on said tractor and being structurally independent of said floating screed. Device according to claim 1, characterized in that the device comprises a plurality of auger-like sections (401, 402, 403), each such section mounting a first and a second deflector plate means (405-408), each covering an arcuate segment of approximately 180°, one of said plate means (405, 407) being disposed at a relatively larger arcuate angle to the axis of the device and the other (406, 408) being disposed at a relatively smaller angle to said axis, and the deflector plates of adjacent auger sections being arranged in complementary orientation such that, on the same side of said device, deflector plates of the first type alternate with deflector plates of the second type. Device according to claim 1, characterized in that the deflector plate means (501) has a helix-like configuration extending for an angle greater than 360°, the end portions of the deflector plate means being mounted in cantilever fashion and being adapted to helically interfit with portions of an adjacent helix-like deflector plate means (504) in the retracted configuration of said device. Device according to any of claims 4-9, characterized in that the panels have their lower edge margin (116) bent upward to form a guide trough for the lower portion of an adjecent movable panel. Device according to claim 1, characterized in that the deflector plate means are each provided with a tongue and groove arrangement (646a, 646b) interconnected with adjacent deflector plate means when said telescoping material distribution device is in its retracted position, or is partially extended. Device according to claim 11, characterized in that it includes a plurality of rectangular tubular structural elements (630, 636) the tongue and groove arrangement comprising a channel-shaped member (646) provided with means (648) for removably attaching the member to the elements. Device according to claim 12, characterized in that the driving channel-shaped member (646) is provided with spaced holes (648) and that there are aligned spaced holes in the adjacent rectangular structural elements (630, 636) for removably fixing said deflector plates to a center driving shaft member (628).

Inventors: CRAIG, ANDREW F.
Applicants: WHITE CONSOLIDATED INDUSTRIES, INC.
Application year: 1987
Main classification: E01C19
IPC codes: E01C19