US3217621A

US3217621A - Street and highway paver

Info

Publication number: US3217621A
Application number: US79413A
Authority: US
Inventors: Elisha S Kubala
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-12-29
Filing date: 1960-12-29
Publication date: 1965-11-16
Anticipated expiration: 1982-11-16

Description

Nov. 16, 1965 E. s. KUBALA 3,217,621

STREET AND HIGHWAY PAVER Filed Dec. 29, 1960 5 Sheets-Sheet 1 VVE/v70@ Eli ha $.Kubala mgl wm wmm mm@ vm v n .nw Qn S mm Nov. 16, 1965 E. s. KUBALA STREET AND HIGHWAY PAVER 5 Sheets-Sheet 2 Filed DSC. 29, 1960 E lsha 5. Kuba/a ATTORNEY NOV- 15, 1955 E. s. KUBALA 3,217,621

STREET AND HIGHWAY PAVER Filed Dec. 29, 1960 5 Sheets-Sheet 3 Elisha S. Kuba/a by da @W ATTORNEY Nov. 16, 1965 E. s. KUBALA 3,217,621

STREET AND HIGHWAY PAVER Filed Deo. 29, 1960 5 Sheets-Sheet 4 Fig. Il

Elisha S. Kuba/a ATTORNEY Nov. 16, 1965 E. s. KUBALA STREET AND HIGHWAY PAVER 5 Sheets-Sheet 5 Filed Deo. 29. 1960 E /isha S. Kuba/a ATTORNEY United States Patent O 3,217,621 STREET AND HIGHWAY IAVER Elisha S. Kubala, 1439 NE. 29th St. Oklahoma City, Okla. Filed Dec. 29, 1960, Ser. No. 79,413 7 Claims. (Cl. 94-48) My invention relates to improvements in vibrated pan-type surfacing apparatus.

INTRODUCTION The general concept of vibrating freshly laid concrete, before it begins to set, is well known. As applied to the laying of concrete pavement, this technique produces the beneficial results of dewatering and densifying the concrete before it hardens, resulting ultimately in a stronger pavement.

Two well known species of apparatus for surfacing concrete With the aid of vibration are the vibratory screed, in which the concrete leveling action of the machine is largely dependent upon a transversely reciprocating strike-off member having auxiliary vibrators attached to it, and the vibrating pan, in which the leveling action is produced principally by hard, downward, high frequency vibratory impulses transmitted to the surface of the concrete by a tamping member having little or no transverse movement. The mode of operation found in vibrating pan apparatus is believed more compatible with the production of strong pavement than that of the vibratory screed. Nevertheless, the latter type of apparatus appears to have enjoyed considerably wider commercial acceptance, despite many efforts in the past to produce an acceptable vibrated pan type of machine. Because the vibrated pan type machine relies primarily on vibration instead of transverse reciprocation of its concrete contacting means, the intensity of vibration required in such a machine is of necessity considerably more potent than that normally produced in the vibratory screed machines in which the vibration is only an accessory of their mode of operation.

In practice, the required intensity of vibration for a successful pan type machine has led to a number of problems, among which are the problems of metal fatigue and undue shaking of the supporting frame, i.e. carriage, of the machine. This may well explain the poorer than expected acceptance of such machines. Accordingly, despite the many prior attempts at producing an acceptable vibrated pan type machine, there remains a demand for improvements therein which alleviate or lessen the above described problems.

OBI ECTS It is a principal object of this invention to fulfill the above described demand. Another object of this invention is to provide a vibratory paving machine adaptable not only for shaking paving material, but also for subjecting it at the same time to a vigorous tamping action.

It is also an object of this invention to provide improved means for connection of the concrete-contacting member of a paving machine with the carriage thereof whereby the transmission of vibrations through said connection is minimized.

Another object of this invention is to provide a vibrated pan-type paving machine which is comparatively light in weight, inexpensive to construct, highly resistant to failure due to crystallization of vital parts and capable of compacting concrete to a very high density at relatively high speed.

THE INVENTION BROADLY I have found that the above objects, and other objects which will readily become apparent to one skilled in the j 3,217,621 Patented Nov. 16, 1965 art from the drawings and the following: description, are fuliilled by a paving machine having: a carriage and propulsion means therefor; a pan; rotary vibration producing means mounted upon said pan and adapted to rotate about an axis generally perpendicular to the line of travel of the machine; and a vibration filtering system associated with said pan and said carriage, said vibration filtering system comprising a multiplicity fof filter units, each of said filter units comprising spring means, a first member secured to said spring means, a second member supportively associated with said first member in `a manner allowing substantially horizontal reciprocatory motion of said second member with respect to said first member parallel to the line of travel of the machine, and means for securing said lter unit to said pan and said carriage.

My invention will become better understood by reading the description of it which follows in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the several figures and in which sectional views are taken in the direction of the reference arrows on the ends of each section line. In the drawings:

FIGURE 1 is a back elevation of the machine in place upon curb forms.

FIGURE 2 is similar to FIGURE l except that in FIG- URE 2 the pan is raised clear of the pavement.

FIGURE 3 is a section through the pan and main beam of the machine.

FIGURE 4 is a section through the wheel extension shafts showing the pan raising apparatus.

FIGURE 5 is a top view of the pan raising apparatus of FIGURE 4.

FIGURE 6 is a detail view of the wheel drive assembly taken from outside the end of the machine..

FIGURE 7 is a perspective view of a broken out portion of the machine taken from the back and looking towards one end of the machine from a point near its center.

FIGURE 8 is a detail of the eccentric rotor shown in FIGURE 7.

FIGURE 9 is a sectional view of the rotor of FIGURE 8, showing a broken out portion of the main beam and depicting the mode of vibration of the pan.

FIGURE 10 is a perspective detail View taken from the front of the machine loo-king towards the wheels. The seat assembly, control station and control rods have been omitted from this view for the sake of clarity.

FIGURE ll is a schematic diagram of the hydraulic power distribution system for operation of the machine.

FIGURE l2 is a top view of the machine in place upon curb forms, with the motors, pumps and. control rods removed for the sake of clarity. Similar omissions are made in FIGURES 13 through 15.

FIGURE 13 is a front elevation of the machine finishing a dat slab.

FIGURE 14 is a front elevation of the machine with the wheels adjusted to ride upon curb forms while finishing a crowned street.

FIGURE l5 shows a front elevation of the machine finishing one half width of a crowned street with one set of wheels adjusted to ride upon the curb, the other upon a form level with the crown of the street at its center.

FIGURE 16 is a perspective view showing the sleeve and stub shaft relationship of a vibration lilter unit.

It should be understood that the above-mentioned drawings and the description which follow are given by way of illustration, not limitation, and represent only what is presently considered by the inventor to be a preferred embodiment of his invention. It is obvious and should be readily apparent to those skilled in the art that modifications and changes can be made without departing from the spirit of this invention. Therefore it is intended that all such changes shall be included within the purview of the claims appended hereto.

THE CARRIAGE The carriage is a rolling support for the machine and derives its support from the forms (FIGURES 1 and 2) containing a body of concrete 21, shown here with preformed curbs. The heart of the carriage assembly is the main beam 23, which runs across the greater part of the Width of the machine. Upon the main beam are located wheel assemblies and means for raising and lowering them; a control station; the power plant and power distribution system; thrust absorbers; and hangers for the vibration filtering means which support all or part of the weight of the pan, depending upon whether the machine is in operation or not.

The main beam 23 of the machine is an I beam having a hump or a crown at its center. Thus, the main beam has a higher elevation at the center of the machine than at the sides thereof.

Stationed at approximately equidistant points across the top of main beam 23 are hangers 39 (see FIGURE 3), supported by posts 40, welded directly to the top of the beam. The hangers aid in supporting the pan in a manner to be explained below and carry guide blocks 4l on their upper surfaces for steadying control rods 38. Located at various points along main beam 23 between said hangers are a reservoir 143 and a number of bases 42 for a gasoline engine 141 and various hydraulic motors and valves which are controlled by the control rods 38. These motors and valves are part of the power distribution system which will also be explained later. The control rods all terminate in handles at a control station 29 on one side of the carriage.

The carriage is constructed in such a manner that the gauge and elevation of its wheel assemblies 33 may be varied. Adjustments have been provided to give several different ranges of wheel height relative to the beam (and the pan). The machine has been provided with the means to continuously vary the wheel height within said ranges and may, within limits, be adjusted to any width of pavement, as well. One or more of the above functions is carried out by the stanchions 24, fulcrum plates 30, pivotable arms 25, extensible shafts 26 and lift cylinders 28, which will now be described in detail as to their placement and manner of cooperation.

The upright stanchions 24 are Welded directly to the ends of the main beam. Several feet inboard of said stanchions on the main beam are located fulcrum plates 30, which depend from cross-beams 31 welded directly to beam 23 (see FIGURE 10). Each fulcrum plate on the machine is provided with three holes 45, 46 and 47, which correspond to three different fulcrum points around which the pivotable arms 25 may be caused to swing. Said arms are secured by nuts 48 and bolts 49 which may easily be removed for the purpose of changing the fulcrum point.

In order to steady the arms 25, they have been connected by a cross-brace 50 and have been provided with buffers 51 (see FIGURES 4 and 5). The inner faces of the arms 25 freely slide up and down over the vertical faces of the buffers, which prevent the arms 25 and their cross-brace 50 from twisting the fulcrum plates 30 as the carriage moves backwards and forwards.

The outer ends of the pivotable arms 25 have box sections 32 which slidably receive extensible shafts 26 and hold said shafts in place by means of set screws 52. The shafts 26 are secured to wheel assemblies on each side of the machine.

As shown in FIGURES 4 and 5, the stanchions 24 are fabricated of angle iron stock 53, leaving a space which is partially closed in by smaller angles 54, resulting in a track which accommodates a slide 55. To the slide 55 is connected one end of lift cylinder 28, the other end 4 of said cylinder being connected to cross-brace 50. In order to prevent damage to the cylinder and x a uniform limit of downward travel for both sides of the machine, each slide 55 is provided with stops 73 welded to the front of said slides. Said stops are positioned in such a manner that they halt further downward travel of the beam, when the cylinder is almost fully retracted, by contacting the top surface of cross-beam 50.

The upward thrust of cylinder 28, exerted through the slide 55, is borne by a long adjusting screw 56 threaded into a cap 57 welded to the head of stanchion 24 and said screw being held safe against unintended change of position by a lock-nut 58. The bottom of said screw abuts the head of the bracket 59 by which cylinder 28 is pivotably secured to the slide 55.

Changes in the gauge of the machine are made by loosening the setscrews 52 and sliding the extensible shafts 26 on each side of the machine in or out until the desired gauge is obtained. Then the set-screws 52 are Ietightened.

Each of the holes 45, 46 and 47 in fulcrum plates 30 corresponds to three ranges of wheel height, high, medium and low, respectively. For work on flat slabs without curbs, the low range (holes 47) would be used. For work on streets with low or high curbs, medium or high range (holes 46 or 45 respectively) would be employed. By means of the long adjusting screws 56, the fulcrum point of the retracted lift cylinders 28 may be adjusted up or down to level the Wheels after the fulcrum point of the arms 25 has been shifted. Then, once the range has been set, as outlined above, the lift cylinders 28 may be extended by feeding hydraulic fluid under pressure to them, thus lifting the beam (and the pan) to any height within the limits of extensibility of the cylinders. Not only are the height ranges of the left and right sides of the machine adjustable independently of one another, but also the same is true of the lift cylinders, as will be shown during the description of the power distribuation system.

Directing the attention now once again to` the wheel assemblies shown in FIGURES 1 and 2, it will be observed that atop the assembly 33 on the same end of the machine las the control station 29 is a box frame 34, auxiliary seat mount 35 and seat 36. Said seat may be mounted either upon the box frame or the auxiliary mount, and the auxiliary mount may itself be mounted outboard of the frame 34 as shown in FIGURES l and 2 or inboard of said frame (not shown). The purpose of the multi-position seat assembly is to make it possible to locate an operator sitting upon said seat at a convenient distance from the fixed control station 29, no matter how little or how far the wheel assemblies 33 are extended from the carriage.

All of the wheels on the machine are driving wheels. However, the left Wheel assembly and right wheel assembly both have their own individual driving motor which makes it possible to drive one set of wheels faster than the other, or even to completely stop one set of wheels while the other set continues to drive its side of t're machine forward or backwards. This innovation makes it possible for the machine to negotiate short radius turns.

A hydraulic motor 61 (see FIGURE l0) located on a motor post 60, welded to the frame of each wheel assembly 33 turns the wheels of each assembly (see FIG- URE 6) through a reducer 64, drive chain 63, and sprockets 65, located on the wheels 66. The wheels rotate on shafts 67 journaled in bearings 68 allixed to the side frames 69 of each wheel assembly 33.

THE PAN Partially surrounding the main beam across its entire length is the pan, which has a high front face '70, a wide bottom (concrete contacting) face 71 and a low rear face 72 (see cross section in FIGURE 3). As may be observed in FIGURES l, 2, 7, l0 and 12-15, the pan is divided -into six individual sections 81-86, each of said sections being pivotally linked to its neighbor by front splice plates 91-95 and rear splice plates 1111-105. Each splice plate is welded to one of two adjacent pan sections and held fast to the other section by nuts and bolts. For instance, in FIGURE the splice plate 91, which joins together pan

sections

81 and 82, is welded to the front face of pan section 81 and secured by bolts to the front face of section 82. The bolts securing the front and rear splice plates may be loosened for the purpose of adapting the pan for forming a contour, such as a crown in the pavement being laid. The bolt holes in the pan which are hidden behind the splice plates are enlarged to permit the movement necessary for such adaptation.

Near each side of the pan, the front face of the terminal pan section is cut back to prevent interference between the pan and the buffers 51 which have been purposely projected forward of the front of the pan in order to keep the pivotable arms 25 from striking the pan when said arms are in their lowest position. This is best illustrated in FIGURE 10 in which the arrow numbered 75 indicates the place to which the front face of pan section 81 has been cut back. In order to guard against the overilow of concrete into the pan across the top of this cntaway portion, flexible skirt 74 having a cut-out 76 for the buffer 51 to pass through is secured to the pan in place of the cut-away portion of its front face.

By adding extensions (not shown) it is possible to increase the overall span or length of the pan. Such extensions may be fabricated of sheet steel in the form of open-top boxes which should have the same depth and width as the ends of pan sections 81 and 86. The extensions, which can be made in several lengths, may be detachably bolted to the ends of the outer pan sections so that the bottom, front and rear faces of the extensions are flush with fthe bottom front and rear faces of the pan sections to which they are attached.

As an aid to proper distribution of the poured concrete in preparation for the first contact of thepan therewith, the inventor prefers to provide the pan with an auxiliary leveling device rigidly secured in spaced apart relation to the front face of the pan. In this embodiment of the invention (see FIGURES 3, 10 and 12-15) said leveling device consists of a plurality of plates 112415 (shown best in FIGURE 12) which are about the same length as the pan sections 82-85 respectively, to which said plates are joined by rigid Spacer bars 122-126. To the ends of the plates 112 and 115 nearest the wheel assemblies 33 are attached plates 111 and 116, which are somewhat shorter in span than the plates 112 through 115, but are similarly supported by rigid spacer bars 121 and 127 respectively. Deilectors or wings 110 and 117 are provided at fthe outer extremities of plates 111 and 116 respectively, said wings being also supported by side braces 120 and 12S respectively.

Proportionally longer spacer bars are used for each successive plate in progression from spacer bar 124, which is at the center of the yauxiliary leveler between plates 113 and 114, to the outermost spacer bars 121 and 127. Therefore the outermost plates extend further forward than the inner or middle plates and the outer ends of the deflectors, which are at an even greater angle with the pan front than said plates (as seen in FIGURE 12), extend further forward than any other part of said leveling device.

The manner of fastening the aforesaid plates to the spacer bars is such that the contour of the lower edges of the plates may always be set to approximate the contour of the pan, no matter whether the pan is set for a flat or crowned pavement. This is accomplished by overlapping adjacent plates at that spacer bar which is common to each and securing said overlapping plates to their common spacer bar by a means of fastening which may be loosened to allow pivotal motion of said plates about an axis perpendicular thereto. For instance, as

shown in FIGURE 10, adjacent plates 111 and 112 overlap at spacer bar 122 and are aixed thereto by a machine screw 118 threaded into the front of the brace 122. Each of the plates 111-116 -is joined in a like manner to its neighboring plates and spacer braces.

The aforesaid machine screws, which pass through oblong vertically oriented slots in the end of each plate, such as slot 119 in plate 111, are set tightly while the machine is in operating condition. For adjustment of the contour created by the plates, the machine screws are loosened at the same .time the bolts on the pan section splice plates are loosened. As the angle of each pan section with the horizontal is changed, a like change ris created in the angle of the plate in front of it, since.

each pan section controls the position of the spacer bar attached to it `and said spacer bar controls the position of the plate in front of the individual pan section. Since the position of each plate is governed by the position of the pan section in front of which said plate is mounted the contour of the auxiliary leveling device is controlled by the pan contour. When the adjustment of the pan and auxiliary leveling device has been completed, the machine screws may be retightened. The oblong slots allow the elevation of the plates to be varied with respect to the bottom surface 71 of the pan. The inventor prefers to have the bottom of each plate parallel to but elevated slightly above the bottom of the corresponding pan section. Said elevation generally falls within the range of 1A inch to 3A inch depending upon the slump ratio of the concrete being laid.

Mounted upon the back of the panare facilities for attaching thereto the necessary vibrators and vibration filtering system. The facilities for attaching the vibration lters to the back of the pan include standards ISU-136. In this embodiment of my invention the standards take the form of short lengths of angle iron welded to the inside surfaces of the back and the bottom of the pan. Standards 131-135 are adjacent the rear splice plates 101-105 and are attached to pan sections 81-85 respectively. Standards and 136 are attached to pan sections 81 and 86 respectively in close proximity to the ends of the main beam 23.

As shown in FIGURES 7 through 9, the vibrator mounts 129 are secured to the pan by welding them to the inside surface of the back of the pan and to the inside surface of the bottom of the pan. A stifener 137 is employed to impart rigidity to the pan in the vicinity of the vibrator. Said stitfener is welded to the mounts 129 and to the inside surface of the bottom of the pan and runs parallel to the back `of the pan.

THE VIBRATION PRODUCING MEANS` The vibrators must operate in a manner such that the pan motion produced thereby is a combination of circular or elliptical motion in a vertical plane and transverse waves resulting in vibratory up and down motion across the width of the pan. Various methods of providing the requisite Vibration are known and many feasible means might be employed. Therefore, it is to be understood that it would not be a departure from the spirit of my invention, nor from the scope of the appended claims to substitute other means of producing the simultaneous orbiting and vibration described above.

A simple and effective means of producing the needed vibrations is shown in FIGURES 7 through 9. Inside a tubular casing 77 attached to mounts 129 is eccentric rotor 78 with shafts 79 and weight 80 journaled in bearings 88 so as to rotate about an axis perpendicuar to the line of travel of the machine. One of the shafts carries a pulley 89. The inventor has determined that rotors having eccentrics 1%. inches in diameter and 14 inches long, placed 1A inch off center and rotated at 3000 to 5000 r.p.m. will give adequate vibration in a machine with a 28 foot pan. The resulting pan motion has a vertical corn- 7 ponent of 3/16 inch and a horizontal component of 1A inch.

Two vibrators are employed in the preferred embodiment of my invention. However, additional vibrators may be utilized if desired. When two are used, the effective center of each should be stationed halfway between the center of the pan and one of its two ends (see FIG- URES 1 and 2). This manner of locating the vibrators aids in the establishment of desirable transverse vibrations. It is possible to interconnect the rotors in order to keep them out of phase; however, practical experience has shown such interconnection to be unnecessary in the now preferred embodiment of this invention. The normal variations in speed and torque between the independent vibrator driving motors 90 and the occasional slippage of the drive belts 140 which transmit power from the motors 90 to the vibrator drive pulleys 89 insure that the vibrators will remain out of phase a sufficient proportion of the time for most work.

THE PROPULSION SYSTEM Any suitable mode of propulsion may be utilized, but the inventor prefers to drive this machine by means of a gasoline engine which turns a hydraulic pump for supplying hydraulic fluid under pressure to a fluid distribution system and hydraulic motors connected thereto. The gas engine 44 is mounted on top of the main beam 23 near the center, as shown in FIGURES l and 2. The hydraulic pump 142 is monuted on the main beam between the gas engine 44 and an oil reservoir 43 for hydraulic fluid. The pump 142, as shown more fully in FIGURE l1, is provided with a relief valve 144, which is ported to the reservoir 143 through a reservoir return line 145. An oil filter 147 may be inserted at any desired point in the system, such as between the reservoir and pump, to collect any foreign material which manages to find its way into the system.

For distribution of the pressurized hydraulic fluid discharged from the continuously operating pump there is a pressure manifold pipe 146. The manifold, as well as the reservoir return line 145 are secured and sheltered within the overhang of the main I beam 23 as shown in FIGURES 3 and 7. At various points along the manifold and return lines, which run almost the entire distance across the span of the main beam 23, are ports at which fluid under pressure is distributed to the wheel drive motors' 61, vibrator drive motors 90 and lift cylinders 28 and ports through which spent fluid from said motors and cylinders is returned to the reservoir.

The vibrator motors 90 are variable speed motors. Each motor has its own cut-off valve 148, 149 and

throttle valve

150, 151 for Varying the rate of flow of hydraulic fluid through the motor, thus providing a means of varying its speed. Since each motor has its own throttle valve its speed may be individually regulated.

Each of the lift cylinders 28 is provided with a Y valve 153, 154 by means of which fluid under pressure may be admitted to the cylinders to raise the pan or by means of which any amount of fluid in the cylinder may be ported to the reservoir. There is also a neutral position in which all of the ports of said valve are closed, permitting no fiuid to enter or leave said cylinder. Since each cylinder is provided with its own independent valve,

the height of each cylinder may be varied and held ind L! 148, 149, the Y valves 153, 154 and the reversing

valves

155, 156 on bases 42 near their respective motors, and to utilize the control rods 38 to actuate them. The

throttle valves

150, 151, 157 and 158 are all mounted upon the control station, where the operator may adjust them conveniently from time to time when necessary.

THE VIBRATION FILTERING SYSTEM Without an effective means of filtering vibrations developed in the pan, the vibrations would he transmitted to the carriage of the machine and tear it apart by shearing off bolts, loosening nuts and crystallizing vital structural members. The inventor has developed a filtering system which is simple, effective and trouble-free. It has proven its ability over months of testing to almost entirely eliminate damage to the machine carriage due to vibration transmission.

The system comprises a multiplicity of identical filter units 160-166, 170-176 located at the front and rear of the pan adjacent the joints between pan sections and near the ends of the beam 23 (see FIGURES l, 2 and l2-15). Each of the above-mentioned units comprises a sleeve 180, a stub shaft 181, a long 4bolt 182, lock nuts 183, lower spring 184, upper spring 185 and bolt head 186. The rear units 1619-166 are afiixed by welding or other suitable means of fastening to standards 13G-136 which have been provided therefor. The front filter units 171- 175 are welded to the front pan section splice plates 91-95 respectively, the remaining front filter units 178 and 176 being welded directly to the front faces of pan sections 81 and 86 respectively. All the sleeves 180 are positioned on the pan so that their axes are at right angles to the axes of the vibrator rotors, which are parallel to the front of the pan. The positions of all the sleeves in the units 160-166 and 170-176 are exemplified by the positioning shown in FIGURES 3, 7 and l0 of the sleeves 188 in

filter units

162, 172, 164, 170 and 171.

We now turn to a description of unit 164 in FIGURE 7, which is illustrative of all the other filter units in the machine save for the manner of attachment to the pan, in which unit 164 differs from the front filters in the manner explained above. Within sleeve 180 is the stub shaft 181 which has a diameter such that it fits closely, but is able to move axially in said sleeve, parallel to the line of travel of the machine, with a minimum amount of friction. Through a diametric hole approximately midway between the ends of stub shaft 181 is threaded the bolt 182. Oversize clearance holes 187 are provided in the sleeve 186 for said bolt to pass through. The diameter of the aforementioned holes should exceed the diameter of the bolt 182 by an amount which is at least equal to the maximum horizontal component of the motion of the pan under operating conditions. (See FIGURE 16.) On the bolt, above the sleeve 180 are lock nuts 183, which constrain upwardly the lower spring 184. Spring 184 is held in place on the bolt between said lock nuts and the bottom of the hanger 39, through which the bolt 182 passes. Between the upper surface of hanger 39 and the head 186 of the bolt is the upper spring 185.

The purpose of the upper springs is to yieldably support some or all of the Weight of the pan and to dissipate downward impulses which might otherwise pass from the pan to the carriage. Therefore, the springs 185 should be sufliciently powerful so that the full weight of the pan is not great enough to fully compress them. To understand the importance of this requirement, it is necessary to note that a fully compressed spring is inelastic to forces tending to compress it further and that an unyielding body will transmit vibratory impulses more readily than a yieldable body.

The purpose of the lower springs is to regulate the size of the vertical component of the motion of the pan and to cushion upwardly directed impulses which might otherwise rack the carriage. By loosening the lock nuts and then tightening them upwards the tension on the lower 9 springs may be increased. Increasing the tension of the lower springs increases their resistance to the upward movement of the pan and therefore has the effect of diminishing the vertical component of the pan movements.

` The upper and lower springs cooperate to maintaln the pan at the proper height with respect to the carriage and forms while the machine is in motion. The lower springs aid, as explained in regulating the vertical component of the pan gyrations. The nature of the combination of hangers, springs, bolt and lock nuts is such that there is no non-resilient connection involved therein which is capable of transmitting vertical vibratory impulses undiminished from the pan to the carriage. i Horizontal fore and aft vibrations are dissipated between' the` sleeve 180 and stub shaft 1&1. As the pan gyrates, it has a horizontal component of motion which is shared by the sleeves 180, which are attached to the pan. However, since the stub shaft and sleeve are able to slide with respect to one another, the stub shaft and the carriage tend towards a smaller component of horizontal motion than the pan. This is a result of the fact that no horizontal component of force can be transmitted t-o the stub shaft and carriage beyond the amount of force required to move the sleeve back and forth over the stub shaft. By suitable means of alleviating friction between stub shaft 181 and sleeve 180, such as 'by lubrication, it is possible to reduce the coefficients of both the starting and sliding friction between these two parts to the extent that the transmission of horizontal fore and aft vibrations from the pan to the hangers by way of the vibration filters is minimized. V- Itis clear that certain changes might be made without departing from the scope of this invention. For instance, it would be possible to atiix the stub shafts 181 to the pan instead of securing the sleeves 180 to the pan. The bolts 182 would then be secured directly to the sleeves and not to the stub shafts. Clearly, the filter, although altered slightly, would still protect the carriage just as well without departing in principle from the mode of operation of the preferred embodiment disclosed herein. It is equally obvious that many equivalents for the

springs

184 and 185 could be substituted therefor without departing from the spirit of this invention.

OPERATION OF THE MACHINE In the course of normal operation, concrete mix is piled in front of the preliminary leveling plates which strike `off the concrete a fraction of an inch higher than the level of the pan. As the -machine proceeds forward, the level- Aing plates push a substantial body of concrete ahead of them. The concave shape of the leveling device aids in keeping the excess concrete in front of the machine. In order to absorb the thrust of the concrete `against the pan assembly, thrust springs 189 and spring guides 19d are provided at intervals across the front of the main beam Y23 (see FIGURE 3).

n l Since the preliminary leveling device is rigidly secured to the pan, it vibrates at the same frequency as the pan and densities the mix partially while striking it olf. The lpreliminary leveling device is followed by the pan which simultaneously pounds and vibrates the concrete beneath it. As the pan passes lover a given area of concrete mix, the mix within said area is caused to vibrate en masse. Not only does the pan transmit vertical impulses to the body of mix, but it also transmits positive horizontal impulses in two directions. The circular or elliptical motion of the pan sends out horizontal impulses parallel to the forms. The out-of-phase vibrator rotors also induce transverse waves which travel through the pan and are transmitted to the concrete wherein said Waves travel perpendicular to the forms.

The resultant three-dimensional agitation of the mix is highly effective in forcing the aggregates to migrate 4to the bottom and settle into intimate inter-locking contact with one another, while the lines are forced to the surface. The vibrations produced by this machine are hard enough to force a considerable amount of water out of the concrete along with entrapped air from deep within the mix. Densification of the mix and settling of the aggregates are performed so satisfactorily with the machine, that it has been found unnecessary to subsequently bull-float the concrete surface in most cases.

If it is necessary to make a second pass over the concrete surface to obtain the proper smoothness, this is easily accomplished. By valving fluid to the lift cylinders 2S, the pan may be lifted clear of the concrete (as shown in FIGURE 2). At the same time, the drive motor valves and 156 should be reversed, causing the machine to back up to the point at which the second pass is to begin. The pan will then be lowered and the drive motors 61 will be started driving forward again.

The concentration of machine components and weight about a single transverse beam as disclosed in this embodiment of the invention, makes it possible to build paving machines with a very short wheel-base. This is a distinct advantage, since it makes it possible for the machine to negotiate short radius curves with ease. In order to improve the negotiability of this machine still further, the inventor has conceived the idea of providing independent drives for the wheels on opposite sides of the machine. Thus on very short radius curves, the Wheels on the inside of the curve may be slowed or stopped While the outer wheels continue to rotate at normal speed to traverse the longer arc of the outside of the curve.

The new concept of paver construction embodied herein was conceived in an attempt to discover a Way of making a single paver do many different kinds of work with only the simplest of modifications being required during the transition from one type of work to another. The resulting machine is capable of paving not only highways, as shown in FIGURES 13 and 15, but also streets with curbs already in place, as shown in FIGURES 1, 2, 12 and 14. Not only may a full crowned street be laid as shown in FIGURE 14, but also very wide crowned streets may be laid in two or more sections, as illustrated in FIGURE 15. FIGURE. 15 shows the wheels on one side of the machine riding upon curb forms, while the opposite wheels are running on a form which runs at pavement height down the center of the road bed. Other kinds of work which may be performed by this machine will suggest themselves to those skilled in the art upon a careful consideration of the above description and examples.

Having fully described a preferred embodiment of his invention, the inventor claims:

1. A paving machine having: a pan; vibration producing means mounted upon said pan; and a carriage with propulsion means therefor, said carriage being adapted to transporting and maintaining said pan at the correct Working level for finishing paving material being treated by said machine, said carriage comprising a horizontal main beam, vertical stanchions disposed upwardly from the ends of said main beam, adjustable fulcra secured to said main beam inboard of said stanchions, pivotable arms secured to said adjustable fulcra and extending outwardly therefrom in a generally horizontal attitude, tracks formed in said stanchions, a slide confined within each of said tracks and adapted for vertical adjustment therein, means for adjusting and maintaining `the position of said slide within said track, lifting means interposed and connected between said. slide and said pivotable arms, receptacles in said pivotable arms, telescoping shafts housed within said receptacles for variable extension outwardly therefrom and wheel assemblies secured to said telescopic shafts, each of said wheel assemblies being provided with individually controllable motor means.

2. A paving machine having: a carriage and propulsion means therefor; hanger means mounted on said carriage;

a pan; rotary vibration producing means mounted upon said pan and adapted to rotate about an axis generally perpendicular to the line of travel of the machine; and a vibration filtering system connected with said pan and said carriage, said vibration filtering system comprising a multiplicity of identical filter units at spaced intervals across said carriage, each of said filter units comprising spring means, generally vertically disposed means connected with said spring means and said hanger means for generally vertical reciprocation, a first generally horizontal member secured to said generally vertically disposed means, and a second generally horizontal member connected in supportive engagement with said first gennerally horizontal member for horizontal reciprocation with respect thereto and generally parallel to the line of travel of the machine, said second generally horizontal member being secured to said pan.

3. A paving machine having: a carriage and propulsion means therefor, said carriage being provided with forwardly and rearwardly projecting hanger means at a plurality of spaced points across said carriage for seating spring means; a pan having a front and rear; rotary vibration producing means mounted upon said pan and adapted to rotate about an axis generally perpendicular to the line of travel of the machine; and a vibration filtering system connected with said pan and said carriage, said vibration filtering system comprising a multiplicity of pairs of filter units secured to said hanger means and to said pan, each of said pairs of filter units comprising a pair of sleeves secured to said pan, one at the front and one at the rear thereof, said sleeves being in a horizontal attitude with their axes parallel to the line of travel of the machine, each of said sleeves having a hole therein, said hole having a dimension parallel to the direction of travel of the machine which is at least equal to the maximum horizontal vibration component of the pan under operating conditions, a reciprocable stub-shaft in each sleeve, a member associated with each sleeve and being disposed reciprocably in a vertical attitude in said hanger means, the member extending through the hole in said sleeve and being secured to said stub-shaft, a first spring means, means for retaining said first spring means on said member above said hanger means, a second spring means, and means for retaining said second spring means on said member below said hanger means.

4. A paving machine having: a carriage and propulsion means therefor; a pan; vibration producing means mounted upon said pan and adapted to set up vibrations in said pan having generally vertical and horizontal components; a vibration filtering system connected with said pan and said carriage, said vibration filtering system comprising a multiplicity of filter units, each of said filter units comprising spring means, means connected with said spring means for generally vertical reciprocation, means supportively connected with said vertical reciprocation means for generally horizontal reciprocation with respect to said vertical reciprocation means, and means for securing said filter units to said pan and said carriage; and said carriage comprising a horizontal main beam, vertical stanchions disposed upwardly from the ends of said main beam, adjustable fulcra secured to said main beam inboard of said stanchions, pivotable arms secured to said adjustable fulcra and extending outwardly therefrom in a generally horizontally attitude, tracks formed in said stanchions, a slide confined Within each of said tracks and adapted for vertical adjustment therein, means for adjusting and maintaining the position of said slide within said track, lifting means interposed and connected between said slide and said pivotable arms, receptacles in said pivotable arms, telescoping shafts housed within said receptacles for variable extension outwardly therefrom and wheel assembly secured to said telescopic shafts, each of said wheel assemblies being provided with individually controlled motor means.

5. A paving machine having: a carriage and propulsion means therefor; hanger means mounted on said carriage; a pan; rotary vibration producing means mounted upon said pan and adapted to rotate about an axis generally perpendicular to the line of travel of the machine; a vibration filtering system connected with said pan and said carriage, said vibration system comprising a multiplicity of filter units, each of said lter units comprising spring means, means connected with said spring means and disposed in a vertical attitude in said hanger means for generally vertical reciprocation, means supportively connected with said vertical reciprocation means for generally horizontal reciprocation with respect to said vertical reciprocation means and generally parallel to the line of travel of the machine, and means for securing said filter units to said pan and said carriage; and said carriage comprising a horizontal main beam, vertical stanchions disposed upwardly from the ends of said main beam, adjustable fulcra secured to said main beam inboard of said stanchions, pivotable arms secured to said adjustable fulcra and extending outwardly therefrom in a generally horizontal attitude, tracks formed in said stanchions, a slide confined within each of said tracks and adapted for vertical adjustment therein, means for adjusting and maintaining the position of said slide within said track, lifting means interposed and connected between said slide and said pivotable arms, receptacles in said pivotable arms, telescoping shafts housed within said receptacles for variable extension outwardly therefrom and wheel assembly secured to said telescopic shafts, each of said wheel assemblies being provided with individually controlled motor means.

6. A paving machine having: a carriage and propulsion means therefor, said carriage being provided with forwardly and rearwardly projecting hanger means at a plurality of spaced points across said carriage for seating spring means; a pan having a front and rear; rotary vibration producing means mounted upon said pan and adapted to rotate about an axis generally perpendicular to the line of travel of the machine; and a vibration filtering system connected with said pan and said carriage; said vibration filtering system comprising a multiplicity of pairs of filter units secured to said hanger means and to said pan, each of said pairs of filter units comprising a pair of sleeves secured to said pan, one at the front and one at the rear thereof, said sleeves being in a horizontal attitude with their axes parallel to the line of travel of the machine, each of said sleeves having a hole therein, said hole having a dimension parallel to the direction of travel of the machine which is at least equal to the maximum horizontal vibration component of the pan under operating conditions, a reciprocable stub-shaft in each sleeve, a member associated with each sleeve and being disposed reciprocably in a vertical attitude in said hanger means, the member extending through the elongated slot in said sleeve and being secured to said stub shaft, a first spring means, means for retaining said first spring means on said member above said hanger means, a second spring means, and means for retaining said second spring means on said member below said hanger means; and said carriage comprising a horizontal main beam, vertical stanchions disposed upwardly from the ends of said main beam, adjustable fulcra secured to said main beam inboard of said stanchions, pivotable arms secured to said adjustable fulcra and extending outwardly therefrom in a generally horizontal attitude, tracks formed in said stanchions, a slide confined within each of said tracks and adapted for vertical adjustment therein, means for adjusting and maintaining the position of said slide within said track, lifting means interposed and connected between said slide and said pivotable arms, receptacles in said pivotable arms, telescoping shafts housed within said receptacles for variable extension outwardly therefrom and wheel assembly secured to said telescopic shafts, each of said wheel assemblies being provided with individually controlled motor means.

'7. A paving machine having: a carriage and means for moving said carriage along a strip of concrete; a concrete contacting pan mounted on said carriage; vibration producing means mounted upon said pan for setting up vibrations in said pan having generally vertical and hori* zontal components in the direction of travel of said machine; and a plurality of vibration dissipating units interconnecting said pan and said carriage at a plurality of spaced points across said carriage, said vibration dissipating units comprising vertical damping means including spring means for damping vertical components of vibration between said pan and said carriage, said dissipating units also including horizontally reciprocating means for generally maintaining the horizontal position of said pan with respect to said carriage as said machine moves along such strip while permitting horizontal movement of said pan parallel to said horizontal components over a distance which is as great as the horizontal component of vibration of said pan when vibrating in contact with such a strip of concrete.

References Cited by the Examiner UNITED 1/1925 1/1934 4/1936 4/1936 5/1936 lll/1937 3/1938 5/1939 9/1940 12/1940 12/1957 l/1959 11/1961 1/1962 STATES PATENTS Ord 94--48 Gordon 914-48 Clitford 94-48 Hertvvig 94-48 McCrery 94--48 Baily 94--48 Baily 94-48 Schieferstein 94--48 Venable 94--48 Baily 94-48 Northcote 2SC-414.5

Westberg ZBO- 43.23

Nave 94-48 Apel 94-45 2O JACOB L. NACKENOFF, Primary Examiner.

WILLIAM l. MUSHAKE, Examiner.

Claims

2. A PAVING MACHINE HAVING: A CARRIAGE AND PROPULSION MEANS THEREFOR; HANGER MEANS MOUNTED ON SAID CARRIAGE; A PAN; ROTARY VIBRATION PRODUCING MEANS MOUNTED UPON SAID PAN AND ADAPTED TO ROTATE ABOUT AN AXIS GENERALLY PERPENDICULAR TO THE LINE OF TRAVEL OF THE MACHINE; AND A VIBRATION FILTERING SYSTEM CONNECTED WITH SAID PAN AND SAID CARRIAGE, SAID VIBRATION FILTERING SYSTEM COMPRISING A MULTIPLICITY OF IDENTICAL FILTER UNITS AT SPACED INTERVALS ACROSS SAID CARRIAGE, EACH OF SAID FILTER UNITS COMPRISING SPRING MEANS, GENERALLY VERTICALLY DISPOSED MEANS CONNECTED WITH SAID SPRING MEANS AND SAID HANGER MEANS FOR GENERALLY VERTICAL RECIPROCATION, A FIRST GENERALLY HORIZONTAL MEMBER SECURED TO SAID GENERALLY VERTICALLY DISPOSED MEANS, AND A SECOND GENERALLY HORIZONTAL MEMBER CONNECTED IN SUPPORTIVE ENGAGEMENT WITH SAID FIRST GENNERALLY HORIZONTALLY MEMBER FOR HORIZONTAL RECIPROCATION WITH RESPECT THERETO AND GENERALLY PARALLEL TO THE LINE OF TRAVEL OF THE MACHINE, SAID SECOND GENERALLY HORIZONTAL MEMBER BEING SECURED TO SAID PAN.