US3272559A - Pavement cutting and earth excavating device - Google Patents

Description

Sept. 13, 1966 HAYNES 3,272,559

PAVEMENT CUTTING AND EARTH EXCAVATING DEVICE Filed June 21, 1965 9 Sheets-Sheet 1 INVENTOR.

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Sept. 13, 1966 HAYNES 3,272,55

PAVEMENT CUTTING AND EARTH EXGAVATING DEVICE Filed June 21, 1965 9 Sheets-Sheet 2 a INVENTOR. laws 51, HAY/V515 Sept. 13, 1966 L. E. HAYNES 3,272,559

PAVEMENT CUTTING AND EARTH EXCAVATING DEVICE Filed June 21, 1965 9 Sheets-Sheet 4 INVENTOR. T l E 104/75 [1 HAY/v55 A TTOP/VEYS Sept. 13, 1966 HAYNEs 3,272,559

PAVEMENT CUTTING AND EARTH EXCAVATING DEVICE Filed June 21, 1965 9 SheetsSheet 5 I N VEN TOR f [:1 522 Lou/5 1 HAY/V515 Sept. 13;, 1966 H Y 3 272559 PAVEMENT CUTTING AND EARTH EXGAVATING DEVICE Filed June 21, 1965 9 Sheets-Sheet 6 h: ar/e0 a INVENTOR. laws .A HAY/V515 Sept. 13, 1966 L. wmmga 337172559 PAVEMENT CUTTING AND EARTH EXCAVATING DEVICE Filed June 21, 1965 9 Sheets-Sheet 9 Tlca-ZZ PUMP 24E] 24C 24]] 24E 24F INVENTOR. T .L E."-

oufs .6, HA wvas B 9 nrrop/vars United States Patent 3,272,559 PAVEMENT CUTTING AND EARTH EXCAVATING DEVICE Louis E. Haynes, 302 S. 6th St., Union City, Tenn. Filed June 21, 1965, Ser. No. 465,611 42 Claims. (Cl. 299-47) This invention relates to a powered device for removing earth surfacing material, such asphalt, gravel or the like, or for removing large quantities of earth to a depth of up to about eighteen inches on a continuous basis. More particularly, but not by way of limitation, the present invention relates to an excavating or pavement cutting device which utilizes a plurality of sequentially reciprocated blades in conjunction with forward motions supplied by a tractor or other self-propelled machine for removing earth, asphalt and similar materials from the surface of the earth. This application is a continuationin-part of my United States application 268,133 filed March 26, 1963 now United States Patent No. 3,219,388.

A great variety of earth working apparatuses of various types have been developed and many of such devices have been directed toward the removal of a substantial quantity of earth from the surface of the ground to varying depths, with such removal being effected in a continuous manner. Other devices related to the earth removing devices include machines which are designed to remove slabs of concrete or asphalt from the surface of a roadbed for the purpose of renewing the surface, or simply for the purpose of reclaiming some of the materials of construction for other uses. Machines of this type have generally been large and complicated and, in some instances, have functioned quite well for some specific utilization, such as removing large quantities of dirt, but have not been sufficiently versatile to permit their use in a variety of operations where surface materials of varying hardness or density and consistency are encountered.

The present invention comprises a machine which can be utilized for a variety of purposes, and which is characterized by an ability to remove larger quantities of surface materials from the earth than has heretofore been possible using different types of bladed structures in which the blades are fixed and power for scraping or removing the surface of the earth is developed primarily by a self-propelled vehicle to which the blades are attached. The apparatus of the invention is further characterized by great versatility in that the machine may be employed for removing stumps in the course of clearing new ground, removing without substantial disturbance, a layer of desired thickness of the earth and then relaying this layer in substantially the same position in which it was located prior to removal, removing and conveying from the site of removal substantial quantities of earth where it is desired to excavate the earth to a certain depth and removing hard surfaces, such as asphalt or pavement, in instances where it may be desired to resurface a roadbed or to destroy an old road while salvaging some of the materials of construction therefrom.

All of the principles which form the basis of the operation of the present invention have not been heretofore entirely unknown. The apparatus of the invention relies primarily upon two forces for developing the cutting, severing and excavating effectiveness of the apparatus, these forces being (a) a rectilinear reciprocating drive imparted to a plurality of blades which are driven in out-of-phase or sequential relation to each other, and (b) the forward motion which is applied to the machinery as a whole by a self-propelled vehicle, such as a tractor. Blades which move with a rectilinear or reciprocating motion have heretofore been utilized in small handdriven machines for removing carpet or linoleum from a floor, but such machines have been entirely unsuitable for uses of the type to which the present apparatus is adapted, and have not been required to have the mechanical strength of construction, or to deliver the power to the reciprocating blades which necessarily characterize the apparatus of the present invention.

Broadly described, the pavement cutting and earth excavating apparatus of the present invention comprises, in combination, a self-propelled vehicle including a prime mover or engine; a power takeoff from the prime mover; a framework spaced from the self-propelled vehicle and carrying a plurality of blades movably mounted on the framework for reciprocation or rectilinear motion in horizontal planes substantially even with or below the lower surface of the ground engaging portions of the selfpropelled vehicle; power transmission means connected between the blades and the power takeoff for driving the blades in sequential, or out-of'phase relation to each other; multiple point hitch connection elements interconnecting the framework and the self-propelled vehicle; and actuating means on the self-propelled vehicle for actuating the multiple point hitch connecting elements to raise and lower the framework, and to incline the framework and the blades carried thereby with respect to a horizontal plane.

To more specifically describe certain aspects of the invention, the framework which is connected to the selfpropelled vehicle by the multiple point hitch connecting elements includes a pair of vertically extending, horizontally spaced side walls or plates extending parallel to the direction of movement of the reciprocating blades; a material supporting inclined ramp positioned adjacent the blades and extending upwardly and rearwardly therefrom; and a material moving conveyor positioned adjacent the ramp for receiving material therefrom and extending transversely between the vertically extending side walls of the framework.

Various types of drive systems may be used for driving the blades in reciprocation from the power takeoff of the self-propelled vehicle. Several preferred types of these will be described in the detailed description of the invention which follows hereinafter. In each instance, however, the blades are reciprocated in a direction corresponding to the direction of travel of the self-propelled vehicle and framework, and the blades are moved in outof-phase relation to each other; that is, one of the blades will complete a cutting stroke as another is commencing its cutting stroke, and as yet another is retracting from its cutting stroke, etc. The cutting forces which come into play to remove the surface of the earth or surfacing material, such as pavement, are thus (a) the forward motion of the self-propelled vehicle and (b) the reciprocating motion of the cutting blades. In a preferred embodiment of the invention, means is provided for synchronizing these two motions so that the machine can be used efficiently in varying types of soils, or in removing surfacing materials of varying hardness and consistency.

Since less force is required to move materials to the rear of the framework away from the cutting blades if the inclination of the inclined ramp and conveyor is relatively small, a preferred construction of the invention further contemplates a low profile conveyor arrangement in which the transmission between the power takeofi and the blades is a novel combination of elements compactly constructed for occupying a minimum of space below the conveyor.

In operation, the framework carrying the reciprocating blades is driven or pulled by a tractor or the like so as to cause the reciprocating blades to bite into the earth or through the pavement or other surface material, according to the purpose to be accomplished. As the framework is pulled along the gro-und, the blades are sequentially reciprocated into and out of the earth at a depth determined by an initial setting on the multiple point hitch connection. The excavated earth or removed surface material is forced to the rear of the framework and onto the conveyor. Any desired disposition may be made of the dirt moved by the conveyor. It has been found that a considerably greater rate of earth and surfacing material removal can be accomplished with the apparatus of the invention than has been attainable with any device known to applicant which has heretofore been used for this same general purpose.

From the foregoing description of the invention, it Will have 'become apparent that it is an important object of the present invention to provide an earth excavating and pavement cutting, or surface material removing, device which can quickly and efficiently remove large quantities of earth or surfacing material, and convey such material to a location where it may be conveniently disposed of in any manner desired.

A further object of the present invention is to provide a mechanically rugged, self-propelled apparatus which can be used to slice away a surface layer of the earth to any depth desired up to about eighteen inches.

An additional object of the present invention is to provide an earth excavating apparatus which includes a plurality of reciprocating blades driven in sequence by novel, mechanically rugged drive systems which can be operated from a power takeoff on a tractor or similar self-propelled vehicle.

Another object of the invention is to provide a selfpropelled earth excavating apparatus which can effectively remove a layer of earth without an undesirably high degree of disturbance to the earth, and then permit the earth to be redeposited in substantially the same location from which it was removed.

Another object of the present invention is to provide a device which can effectively remove asphalt from a roadbed and convey the cut portions of the asphalt to a suitable heated tank where the asphalt can be quickly remelted and respread, thus saving considerable cost.

A further object of the invention resides in the provision of a device which can be quickly and effectively attached to a conventional land surface self-propelled vehicle in a manner which permits the device to he driven into the earth to a desired depth, at which the depth the device will automatically level off and proceed to remove the earth along a horizontal plane therein.

Another object of the invention is to provide means connected to the cutter blades of the device for removing asphalt or other surfacing materials so as to reciprocate some of these blades out of phase with other blades to thereby make the device continuously effective for cutting pavement or asphalt.

An additional object of the invention is to provide an earth excavating and surfacing material removing device which can be driven by a self-propelled vehicle using a power takeoff therefrom, and including means for synchronizing the rate of movement of the self-propelled vehicle and excavating device along the ground with the reciprocating movement of the cutting blades which are provided in the device.

Another object of the invention is to provide an earth excavating device which is efficient in operation, and which requires a minimum number of parts and maintenance.

An additional object of the invention is to provide an earth excavating and pavement cutting device which is very strongly constructed, is mechanically durable and is characterized by a long and trouble-free operating life.

In addition to the foregoing described objects and advantages, other objects and advantages will become apparent as the following detailed description of the invention is read in conjunction with the accompanying drawings which illustrate various aspects and embodiments of the invention.

In the drawings:

FIGURE 1 is a side elevational view of one embodiment of the present invention showing a tractor vehicle in use to control the orientation of excavation elements relative to the ground and to propel the apparatus in its operation.

FIGURE 2 is a detail view illustrating the elements utilized to connect the earth excavating and pavement cutting device of the invention to a tractor by a four point hitch connection, and showing the manner in which the hitch links and the driving elements connected thereto are used to adjust the elevation and vertical inclination of the pavement cutting device with respect to the ground.

FIGURE 3 is a View similar to FIGURE 2 illustrating the earth excavating and pavement cutting device as it is positioned by the actuating elements of a tractor preparatory to driving the device into the ground.

FIGURE 4 is a plan view further illustrating the manner in which the earth excavating and pavement cutting device is connected to the tractor by a plurality of hitch links.

FIGURE 5 is a longitudinal sectional view through the center of one embodiment of the apparatus of the invention, and illustrating the relationship of the various components utilized in the invention, except for the selfpropelled vehicle or tractor which supplies the power for operation of the apparatus.

FIGURE 6 is a sectional view showing the interior of the gear box which houses the gearing used to interconnect a drive shaft with a crankshaft used in the invention.

FIGURE 7 is a sectional view taken substantially along the plane of the line 7-7 of FIGURE 5.

FIGURE 8 is a sectional view taken substantially along the plane of the line 88 of FIGURE 5 and illustrating the guide means used for guiding the reciprocating cutter blades utilized in the embodiment of the invention illustrated in FIGURES 1 through 9.

FIGURE 9 is a fragmentary side elevational view of the apparatus of the invention with the cover housing for the conveyor drive assembly removed to more clearly illustrate the latter.

FIGURES 10 through 16 illustrate a different embodiment of the present invention, various aspects and details of which are depicted in the several figures as follows:

FIGURE 10 is an elevational view illustrating the manner in which the earth excavating and pavement cutting framework and reciprocating blades are connected to a self-propelled vehicle, such as a farm tractor, using a three point hitch connection.

FIGURE 11 is a longitudinal sectional view taken in a vertical plane through the earth excavating and pavement cutting portion of the apparatus illustrated in FIG- URE 10 and showing the moving parts of this portion of the apparatus as such parts would appear if one of the vertically extending side walls or plates of the framework were removed.

FIGURE 12 is a longitudinal sectional view taken in a vertical plane and extending through the earth excavating and pavement cutting portion of the invention illustrated in FIGURE 11 with the FIGURE 12 section being taken near the centerline of the framework used to support the dirt moving conveyor and the reciprocating blades.

FIGURE 13 is a plan view of the earth excavating and pavement cutting portion of the invention as it appears when viewed from the above with the conveyor belt and lowermost conveyor roller removed in order to better illustrated certain elements of the invention.

FIGURE 14- is a horizontal sectional view taken through the earth excavating and pavement cutting portion of the machine along line 1414 in FIGURE 11.

FIGURE 15 is a perspective view of the earth excavating and pavement cutting portion of the assembly shown in FIGURE 10.

FIGURE 16 is a section taken along line 16-16 in FIGURE 13.

FIGURES 17, 18 and 19 illustrate yet another embodiment of the invention which is particularly useful by reason of the low profile conveyor, and low surfaces over which the excavated dirt is moved, and which incorporates a novel transmission system which is enclosed in a sealed lubricating chamber, and a particularly sturdy drive system for the reciprocating blades. The several figures in this series may be described as follows:

FIGURE 17 is a perspective view illustrating the modified embodiment of FIGURES 17 through 19 as it appears when detached from the self-propelled vehicle to which it is adapted to be attached by a three point hitch connection.

FIGURE 18 is a side elevational view of the earth excavating and pavement cutting device depicted in FIG- URE 17 as the same would appear with one of the vertically extending side plates removed. A portion of the hollow central partition which houses the vertically extending drive shaft utilized in this embodiment of the invention has been broken away to better show the position of the drive shaft.

FIGURE 19 is a sectional view taken along the horizontal plane defined by line 1919 in FIGURE 18.

FIGURES 20 and 21 illustrate yet another embodiment of the invention in which yet a different drive system is used to convey power from the power takeoff on a self-propelled vehicle to the reciprocating blades used in the earth excavating and pavement cutting portion of the invention. In these figures, FIGURE 20 is a view of the earth excavating and pavement cutting portion of the apparatus similar to that shown in FIGURE 18, i.e., this portion of the apparatus as it would appear when viewed in elevation with one of the vertically extending side plates removed, and a portion of the hollow central partition broken away to better illustrate the drive shaft.

FIGURE 21 is a horizontal sectional view taken along the plane defined by line 2ll21l in FIGURE 20. A portion of the gear drive used in this embodiment of the invention has been broken away in order to better illustrate the manner in which the several gears carrying eccentric studs or pins are utilized to drive the reciprocating blades in out'of-phase relation to each other.

FIGURE 22 is a partially schematic view of a modified drive system which is utilized in a preferred embodiment of the invention for driving the reciprocating cutting blades used in the invention in out-of-phase relation. This figure depicts the manner in which the hydraulic drive system is adapted to permit the rate at which the blades are reciprocated to be synchronized with the rate at which the self-propelled vehicle used to move the earth excavating and pavement cutting device is advanced along the ground.

FIGURE 23 is a sectional view taken along line 23--23 of FIGURE 22.

FIGURES 24a-24f are schematic sectional views taken through several of the fluid injection and discharge ports used in the hydraulic drive system depicted in FIGURES 22 and 23, and showing the manner in which these ports are circumferentially spaced around a solid cylinder throughwhich they extend.

Referring now to the drawings in detail, and particularly, to FIGURES 1 through 4, the main framework used in the earth excavating and pavement cutting device of the invention is designated gene-rally by reference character It). The framework includes a pair of horizontally spaced, vertically extending side Walls 12 and 14 which are connected to each other by a transversely extending plate 16 which is secured to the vertically extending plates 12 and 14 at the lower edges thereof. The vertically extending side walls 12 and 14 each have secured adjacent the rear edge 18 thereof, a pair of vertically spaced connecting pins, the uppermost of which are designated by reference character 29, and the lowermost of which are designated by reference character 22. Pivotally connected to the pins and 22 are pairs of elongated hitch links 24- and 26. The links 24 connected to the uppermost pins 20 are utilized for canting or inclining the framework 10 with respect to the surface of the earth, as hereinafter explained. The hitch lengths 24 are connected at their other ends to a hydraulic cylinder 27 or other actuating mechanism disposed on a suitable self-propelled vehicle, such as a tractor designated generally by reference character 28 and illustrated in FIGURE 1. The large hitch lengths 26 which are connected at one of their ends to the lowermost pins 22 on the framework 10 are rigidly secured at their other ends to an arm 30 on the tractor 28, which arm 39 is pivotally connected to a support beam 32 for pivotation about a pivotal axis 34. The arm 30 is driven in its pivot-a1 movement by a suitable hydraulic cylinder 36 mounted on the tractor and fixed to an upright stanchion 38.

Power for the operation of the earth excavating and pavement cutting apparatus of the invention is developed by the engine an of the tractor 28, and is transmitted to the reciprocating blades mounted on the framework 10 (as hereinafter described) by a suitable power takeoff 42 from the engine '40. The power takeoff 42 is connected to a coupling shaft 43 which is connected through a universal joint 4-4 to a drive shaft 46 which enters a gear box 43 mounted on the horizontally extending transverse plate 16. A bevel ring and pinion type gear 49 is mounted in the gear box 48 as illustrated in FIG- URE 6. The bevel ring and pinion gear 49 is used to drive a crankshaft designated generally by reference character 50 from the drive shaft 46.

The crankshaft 50 extends transversely across the framework 10 and is journaled at its ends in a pair of bearings 52 and 54 mounted on the vertically extending side plates 12 and 14 (see FIGURE 7). The crankshaft 50 is provided with a plurality of radially offset, circumferentially spaced throw portions 56 which are spaced from each other along the longitudinal axis of the crankshaft. The number of throws 56 which are provided correspond in number to the number of reciprocating blades which will be utilized in the invention as hereinafter explained. The circumferential spacing of the throws is preferably equal and corresponds to 360 divided by the number of throws which are provided (four in the illustrated embodiment).

Connecting rods or crank arms 58 are pivotally jouirnaled at one of their ends 60 on each of the throws 56. At their opposite ends 62, the crank arms 58 are pivotally connected by means of crank pins 63 (see FIGURE 5) to knuckle bearings 64 which are rigidly secured in horizontally spaced relation to the rear portions of each of a series of elongated cutter blades designated generally by reference character 66. The construction of the cutter blades may perhaps best be understood by referring to FIGURES S and 7. Each of the cutter blades 66 includes an enlarged head 68 which is tapered to a sharp cutting edge '70 at the forward end thereof. The cutter blades 66 further include a transversely reduced shank portion 72 which is connected to, or formed integrally with, the enlarged head 68, and which supports at its rearmost end the bearing knuckles 64. It will also be noted in referring to FIGURE 5 that the enlarged head 68 of each of the cutter blades is thicker in its vertical dimension than the reduced shank portion 72 of the blade.

In order to support the cutter blades 66 in their reciprocating movement, hereinafter described, a cutter blade supporting bar 74 extends transversely across the framework 10 and is secured to the lower edges of the vertically extending side plates 12 and 14. Spaced above the cutter blade supporting bar 74 by a distance sufficient to permit the reduced portions 72 of the cutter blades to be extended therethrough is a cutter blade retaining bar 76. The cutter blade retaining bar 76 is provided with a relatively flat lower surface and an arcuate or concavely dished upper surface so as to permit the reduced shank portions 72 of the cutter blades 66 to slide against the lower surface of the cutter blade retaining bar and to permit a conveyor to be mounted in juxtaposition to the forward, upper surface of the cutter blade retaining bar for a purpose hereinafter explained.

In order to guide and to maintain the position of the cutter blades 66 in the course of their reciprocating motion, a plurality of spacer guide plates 80 are provided between the cutter blade supporting bar '74, and the cutter blade retaining bar 76 at spaced intervals along the transverse extent of these members, with the spacing between the spacer guide plates corresponding to the width of the reduced shank portions 72 of the cutter blades 66. It will thus be seen in referring to FIGURE 8 that the spacer guide plates 86, the cutter blade supporting bar 74 and the cutter blade retaining bar 76 provide channels in which the cutter blades may move during reciprocation, which channels function to maintain the alignment of the cutter blades and guide them in their move-ment.

For the purpose of preventing an accumulation of dirt around the cutter blades 66, and to permit excavated dirt to be moved to a position for permitting more convenient disposal, the apparatus of the invention is provided with an endless conveyor belt 84 which is extended over a forward roller 86 positioned in the concavely dished upper surface of the cutter blade retaining bar 76, and a rear roller 88 spaced vertically above the crankshaft '50. The drive for the conveyor 84 is obtained by mounting a sprocket or pulley 90 on the end of a shaft 92 which carries the roller 88. The pulley 96 is positioned above a sprocket or pulley 94 carried on one end of the crankshaft 50 which projects through the side wall 12, as best illustrated in FIGURES 7 and 9. An endless belt 96 drivingly interconnects the pulleys 90 and 94- so that the rotary motion of the crankshaft 50 is transmitted to the shaft 92 to which the conveyor roller 88 is keyed. A suitable cover or housing 98 is secured to the vertically extending side wall 12 and covers the pulleys 90 and 94 and the belt 96, as best illustrated in FIGURES 3 and 9.

An arcuate slide plate 100 is secured between the vertically extending side walls 12 and 14 of the framework 10 and is positioned to the rear of the conveyor belt 84 to receive dirt therefrom and convey the dirt to the rear of the framework. Any suitable means of disposal may be provided on the framework in addition to the conveyor 84 and slide plate 100, such as a heated hopper for receiving materials such as asphalt or pavement for melting these materials for reutilization. There may also be an additional conveyor system (not shown) connected to the rear of the framework 10 for removing dirt excavated by the apparatus to a remote location, or for loading the dirt into a hopper, dump truck or similar device.

In the operation of the embodiment of the invention illustrated in FIGURE 1, the framework 10 can initially be elevated and inclined with respect to the surface of the earth by means of the hitch links 24 and 26 as illustrated in FIGURES 2 and 3. The heavy, more mechanically sturdy links 26 are employed for bodily lifting the framework 10 out of the earth, or above the surface of the earth, and the links 24 are utilized to cant or incline the framework with respect to the surface of the earth. After positioning the apparatus, as illustrated in FIGURE 3, the tractor 2%; or other driving, self-propelled vehicle is moved forwardly in the direction of the framework 10 and, at the same time, power is transmitted to the cutter blades 66 via the power takeoff 42 and shafts 43 and 46. As the tractor 28 moves forward, the framework 10 is forced into the earth and is then leveled out by the use of the hitch links 24, accompanied by a gradual lowering of the hitch links 26. The power input to the gear box 48 drives the crankshaft 50 through the ring and pinion gearing 49 located in the gear box. As the crankshaft 54 is rotated, the horizontally spaced eccentric throws 56 located thereon are also rotated and cause the connecting rods 58 to move with an oscillating movement which is translated to rectilinear or reciprocating motion by reason of the pivotal connection between the connecting rods and the throws 56 at one of their ends, and the bearing knuckles 64 via the crank pins 63 at their other ends.

It will be noted in referring to FIGURE 5 that the forward or power stroke delivered to the cutter blades 66 through the connecting rod 58 occurs at the time when the connecting rods are most nearly aligned with the path of motion of the cutter blades. Stated differently, the forward or cutting stroke of the cutter blades 66 commences as the eccentric throws 56 approach the transverse plate 16 in their clockwise rotating movement and continues as the throws pass through their point of nearest approach to the transverse plate 16. This construction considerably improves the mechanical strength of the power transmission structure, and increases the operating life of the cutter blade drive mechanism.

As the cutter blades are reciprocated or driven in rectilinear motion, they are guided in this motion by the cutter blade supporting bar 74-, the cutter retaining bar 76 and the spacer guide plates 80. The cutter blades 66 are driven forwardly into the earth by the motion of the crankshaft 50 and through the connecting rods 58 so that the cutter blades have a compound motion imparted to them by the drive system from the power takeoff 42, as well as the forward motion of the tractor 28. The motion of the tractor 23 and the cutter blades can be synchronized to give maximum digging effectiveness in soils of varying consistencies and hardness. The level at which the blades 66 cut through the earth can be adjusted by proper manipulation of the hitch links 24 and 26, and the machine is capable of removing earth at depths up to nearly two feet.

As the earth removed by the cutter blades 66 moves toward the tractor 28 by reason of the forward motion of the tractor, it passes over the cutter retaining bar 76 and onto the conveyor belt 84. The conveyor belt moves the loose earth upwardly and onto the slide plate 100. From the slide plate 100 the dirt may be removed to a remote location for disposal, or may be permitted to return to the earth as in a plowing operation, or in an operation where it is merely desirable to loosen or move the upper surface of the soil. The machine as thus far described can also be used for removing a hard surfacing material, such as asphalt or other paving material when it is desired to renew or replace the surface of a roadbed. The asphalt is sheared away or cut to a desired depth by the cutter blades 66 and the pieces of asphalt are carried upwardly by the conveyor belt 84 and deposited on the slide plate 100. From the slide plate 106 the asphalt may be deposited in a melting vat (not shown), further conveyed to a dump truck or disposed of in any other suitable manner.

Another form or embodiment which the invention may assume is illustrated in FIGURES 10 through 16 of the drawings. In referring to these figures, a tractor vehicle 106 of the agricultural type is positioned ahead of a framework 108 which carries the earth excavating and pavement cutting apparatus used in the invention. The framework 108 includes, similarly to the embodiment illustrated in FIGURES 1 through 9, a pair of vertically extending, horizontally spaced side walls 116 and 112. A horizontally extending, forward transverse blade support member 114 is connected at each of its opposite ends to the side walls 110 and 112, as well as to the forward end of a pair of horizontal Q blade support plates 116 secured to the lower edge of each of the side walls and 112.

The side walls 110 and 112 are further interconnected by a transverse, generally L-shaped brace 118 which is spaced upwardly from the lower ends of the side walls 110 and 112 and toward the rear, vertical edges 12f) thereof. Another structural element interconnecting the side walls 110 and 112 is a large angle iron, gear box-supporting, transverse beam 122 which extends between the side walls adjacent the upper edges 123 thereof and provides a support for a gear box and drive shaft as hereinafter explained.

A blade shank guideway designated generally by reference character 124- extends transversely between the side walls 112 and 110' and is secured at its opposite ends to the lower edges thereof. The blade shank guideway 124 includes a lower plate 126, an upper plate 128 and a plu rality of spacer members (not visible) which function to retain the upper and lower plates 128 and 126, respectively, in spaced relation to each other, and also to guide the cutter blades in their reciprocation motion, as will be hereinafter explained. The lower plate 126 of the blade shank guideway 124 extends rearwardly in the framework 112 in horizontal coplanar alignment with the lower edges of the side walls 112 and {111} to a point slightly beyond the rear edges of the side walls.

The lower plate 126 is provided with a plurality of slots or apertures 132 in transversely spaced relation therealong to permit dirt moved rearwardly by the cutter blades and infiltrating under the conveyor (hereinafter described) to gravitate from the machine during the operation thereof. The upper plate 128 of the blade shank guideway 124 carries a plurality of rollers which are journaled therein and are positioned to bear against the upper surface of the shanks of the cutter blades as the same are reciprocated through or between the upper and lower plates 128 and 126, respectively, as hereinafter explained.

Welded or otherwise suitably secured to each of the side walls 110 and 112 at positions adjacent the forward edge 134 thereof, and spaced well up on the respective side walls are a pair of outer hitch brackets 136 and 138, respectively. The outer hitch brackets 136 and 138 are provided with a plurality of channels having apertures in the sides thereof to permit the outer hitch links which are secured therein to be transversely adjusted in their points of attachment as may be desired. In referring to FIGURE 10, it will be noted that the framework 112 is connected to the tractor 1116 by a three point hitch connection which includes outer hitch links 140 which extend from the brackets 136 and 138 to the tractor 106, and which are connected to suitable actuating means on the tractor to permit the framework 108 to be raised or lowered in a vertical direction, as hereinafter more fully explained.

A third bracket for connecting the third and central hitch link which extends between the tractor 1116 and the frame 103 is provided by a pair of braces 142 which are welded or otherwise suitably secured at one of their ends 144 to the outer hitch brackets 136 and 1 38, and which are bent inwardly over a major portion of their length and then upwardly at their upper ends 146 to provide parallel opposed ears forming a hitch bracket to receive one end of the central hitch link 1148. The upper ends 146 of the members 142 are apertured as designated by reference character 150 (see FIGURE 11) to permit a pin to be passed through the end of the central hitch link 148 and the upper ends 146 of the members 142. The hitch link 148 is connected at its forward end to an actuating mechanism (not visible), such as a hydraulic piston and cylinder assembly, on the tractor 106 to permit the framework 108 to be pivoted about a horizontal axis extending through the points of connection of the outer hitch links 140 to their respective hitch brackets 136 and 133. In order to add structural strength and support to the members 142, a pair of angle braces 154 are extended 19 between the transverse angle iron beam 122 and the members 142, as best illustrated in FIGURE 13.

The cutter blades employed in the embodiment of the invention illustrated in FIGURES 10 through 16 are somewhat similar to the cutter blades illustrated in the embodiment of the invention depicted in FIGURES 1 through 9 and previously described. The cutter blades are designated generally by reference character and include a sharpened cutting edge portion 162 and a shank portion 164 extending rearwardly from the cutting edge. The shank portion 164 of each cutter blade 160 is slidingly supported on the transverse blade support member 114 and the lower plate 126 of the shank guideway 124. It will also be noted in referring to FIGURE 12 that the shank portions 164 of the cutter blades 16 pass beneath the upper plate 128 of the shank guideway 124 and are in contact with the rollers 132 carried thereby.

In order to guide and further support the shank portions 164 of the blades 160 during the reciprocating motion of the blades, a plurality of double channel guide bars 165 are extended between the shank guideway 1 24 and the transverse blade support member 114, as illustrated in FIGURES 13 and 16. The channel guide bars 165 are horizontally spaced from each other and are positioned to slidingly engage the side edges of the shank portions \164 of the blades 160. The I-shaped crosssectional appearance of the guide bars 165 is illustrated in FIGURE l6. In the illustrated embodiment, the guide :bars 165 include a lower plate 166, a top plate 167 and a spacer bar 168 between the lower and top plates.

In order to protect the laterally outer edges of the shank portions 164 of the two outermost blades 160 from becoming impacted with dirt during operation of the apparatus, a pair of horizontally extending protective cover plates 169 are secured along each of the side walls 110 and 112 just above the blades. Confining guideways or channels are thus formed for these particular blade shank portions by the horizontal support plates 1 16 and the cover plates 169 attached in pairs to each of the side Walls 110 and \112.

In order to better facilitate movement of the frame 108 along the ground during an earth excavating or pavement cutting operation, a shaft 170 is positioned at the lower rear end of the framework 108 and is journalled in horizontally spaced brackets 17'1 welded or otherwise secured to the lower plate 126- and the side walls 110 and 112. A roller 158 is keyed to the shaft 170' and projects slightly below the lower plate 126 to reduce the frictional drag of the framework 108 as it is pulled behind the tractor 106.

The transmission system utilized to drive the cutter blades 160 in reciprocating, out-of-phase motion includes a includes a power input shaft 172 which is adapted for connection through a universal joint 173 to a power takeoff shaft 174 extending from the tractor 106. The power input shaft 172 extends through a journal block 175 supported from the upper ends 146 of the members 142 and into a gear box 176 mounted centrally on the transverse angle iron beam 122. A ring and pinion or other suitable gear (not seen) enclosed in the gear box 176 transmits the rotational movement of the power input shaft 172 to a transverse drive shaft 177. The transverse drive shaft 177 extends through a journal block mounted on the transverse angle iron beam 122 near the end thereof and is keyed at its outer end to a drivesprocket 178. A portion of the transverse angle iron beam 122 is cut away to permit a drive chain 179 to be extended around the drive sprocket 178 and downwardly along the side wall 110.

At its lower end the drive chain 179 is passed around a driven sprocket 18% which is mounted on one end of the crankshaft 181. The crankshaft 181 is shaped similarly to the crankshaft 50, as illustrated in the FIGURE 1 through 10 embodiment, and which has been described in referring thereto. Thus, the crankshaft 181 is provided with a plurality of radially offset, circumferentially staggered throws 182 spaced from each other over its length and corresponding in number to the number of cutter blades used in the apparatus. Similarly also, the throws 182 are arranged circumferentially around the crankshaft 181 to provide out-of-phase actuation of the blades 160. The crankshaft is extended through a plurality of journal-carrying, trapezoidally-shaped vertical blocks 183, and is rotatably supported in journals carried thereby. The vertical blocks 183 are secured at their lower ends or bases to the lower plate 126, and at their upper ends to the L-shaped brace 118.

Each of the throws 182 on the crankshaft 181 is connected by means of a crank pin 184 to one end of a connecting rod 185 which is secured by a pin 186 extending through its other end to a connecting bracket 187 secured to, and extending upwardly from, the shank portion 164 of one of the cutter blades 160. Thus, each of the cutter blades 160 is connected by a connecting rod 185 to one of the throws 182 of the crankshaft 181.

The conveyor system used in the embodiment illustrated in FIGURES through 16 is best illustrated in FIGURES ll, 12 and of the drawings. The conveyor system includes an endless belt conveyor 188 which is extended around a pair of rollers 189 and 190 mounted in the positions illustrated in FIGURE 11. The roller 189 is supported on a shaft 191 which is carried by a plurality of vertical shaft supporting members 192 secured at their lower ends to the lower plate 126 and projecting upwardly and rearwardly therefrom so as to position the roller 189 slightly to the rear of the framework 108. At its end which is most proximally positioned with respect to the side wall 112, the shaft 191 is provided with a drive sprocket 193 which permits the shaft to be driven in rotation by a chain 194- extended around the sprocket 193 at one end thereof, and around a second sprocket 195 which is connected to the opposite end of the crankshaft 181 from the end thereof which carries the driven sprocket 180.

The roller 190 is keyed to a shaft 196 which is rotatably journaled in the side walls 110 and 112 of the framework 108.

In order to protect the transmission mechanism and the moving blade shanks 164 from impaction by dirt which may slip off the conveyor belt 188 and gravitate downwardly within the framework 108, a pair of overhanging protective plates 197 are secured to the side walls 110 and 112 and extend outwardly over the opposed edges of the endless conveyor belt 188, and preferably bear lightly thereagainst to form a seal to prevent by-pass of dirt. It will be noted in referring to FIGURE 11 that the cover plate 197 which is secured to the side wall 110 is either slotted or is interrupted and broken away over a portion of its length in order to permit the chain 179 interconnecting the drive sprocket 178 with the driven sprocket 180 to be passed through the cover plate.

A final element which is incorporated in the embodiment of the earth excavating and pavement cutting apparatus illustrated in FIGURES 10 through 16 is a lift plate 198 which is utilized to receive dirt loosened and removed by the cutter blades 160, and to move this dirt upwardly onto the endless conveyor belt 188. The lift plate is illustrated in section in FIGURES 11 and 12, and in elevation in FIGURES l3 and 15 and is designated by reference character 198. It will be noted in referring to the sectional views of the lift plate 198 that the plate is inclined with respect to the vertical at approximately the same angle as the angle of inclination of the endless conveyor belt 188, and that the lift plate 198 is aligned with the conveyor belt so that dirt can move smoothly from the lift plate onto the conveyor belt. The lift plate 198 extends transversely across the framework 108 and is secured at its opposite ends by bolting to anchor 12 plates 199 welded or otherwise suitably attached to each of the vertically extending side walls and 112.

In the operation of the embodiment of the invention illustrated in FIGURES 10 through 16, the framework 108 is attached behind the tractor 106 by a three point hitch connection utilizing the outer hitch links and the central hitch link 148. The outer hitch links 140 can be lifted upwardly to vertically elevate or lower the framework 108 when it is desired to pull the framework out of the ground or lower it into a resting position thereon. The central hitch links 148 can be extended in length by a conventional actuating mechanism on the tractor 106 to cause the framework 108 to pivot about a horizontal axis extending through the hitch brackets 136 and 138.

By canting or inclining the framework 108 with respect a to the surface of the earth, it may be caused to bite downwardly or dig into the earth, and the setting on the central hitch link 148 determines the depth to which the cutter blades will dig before the framework levels out and assumes a horizontal position. An interesting aspect of the invention is that the framework will automatically level out at a selected depth without further actuation of the central hitch link 1148 as a result of the change in the vertical position of the framework 108 with respect to the tractor 106 as the framework settles down to the desired depth. This action occurs because of the fixed radius of the central hitch link 148 once its length is set, and the manner in which the framework is pivoted on the two outer hitch links 140.

Once the cutter blades 160 have reached the desired cutting depth, the excavating operation commences or, alternatively, in a different use of the apparatus, the surfacing material, such as asphalt or other paving material, commences to be stripped away to a desired depth. The cutter blades are driven in rectilinear or reciprocating motion by power delivered from the power takeoff 174 of the tractor 106. Thus, the power input shaft 172 is driven in rotation and, through the gearing located in the gear box 176, drives the drive shaft 177 in rotation. Through the sprockets 178, chain 179 and drive sprocket 180, the crankshaft is caused to rotate in the journals provided in the journal-carrying blocks 183. Rotation of the crankshaft 181 in turn causes the cutter blades 160 to be rotated in out-of-phase relation because of the manner of connection of the connecting rods to the throws 182 of the crankshaft, as hereinbefore explained.

As dirt or paving material is cut away by the cutter blades 160, it moves up over the lift plate 198 and moves onto the endless conveyor belt 188. The endless conveyor belt is driven in rotation by power delivered through the chain 194 to the sprocket 193 mounted on one end of the shaft 191 carrying the conveyor roller 189. As the endless conveyor belt 188 moves in a counterclockwise fashion, as viewed in FIGURE 11, the excavated dirt is moved rearwardly in the framework 108 and is deposited on the ground to the rear of the framework, or may be conveyed to a dump truck or otherwise handled as may be desired. The roller positioned to the rear of the framework 108 and projecting slightly below the lower surface of the lower plate 126 functions to reduce the frictional drag which the framework 108 imposes on the tractor 106 and permits the apparatus to be moved forward more easily.

A modified embodiment of the invention is illustrated in FIGURES 17, 18 and 19. The portion of this embodiment there illustrated comprises the frame carrying the conveyor mechanism and the cutter blades for slicing through the earth and removing the earth as the framework is advanced by a tractor or other suitable selfpowered vehicle (not shown). The framework is designated generally by reference character 200 and includes horizontally spaced, vertically extending side walls 202 and 204. Mounted on the side wall 204 adjacent the forward vertical edge 206 thereof, and at a position relatively high on the side wall is an outside hitch bracket 208 having a plurality of horizontally spaced channels and apertures 210 for facilitating the connection of an outside hitch link thereto by use of a pin or other suitable means. A second outside hitch bracket 212 is provided in a corresponding position on the side wall 202 adjacent the front edge 214 thereof, and also includes a plurality of horizontally spaced channels defining horizontally aligned apertures 213 to accommodate a hitch pin. As in the case of the embodiment illustrated in FIGURES through 16, the hitch brackets 208 and 212 provide points of connection for the outer or lateral hitch links used in a three point hitch connection for connecting the framework 200 to a tractor or other self-powered vehicle.

The vertically extending side walls 202 and 204 are interconnected by a horizontally extending base plate 216 which extends between and is secured to the lower edges of the vertically extending side walls. The horizontal base plate 216 extends from the rear edges 218 of the side walls 202 and 204 to a position about two-thirds of the way forward on the side walls where it terminates in a transversely extending forward edge 220. A transmission housing, designated generally by reference character 222, is welded or otherwise suitably secured to the upper surface of the horizontal base plate 216 at a position relatively close to the forward transverse edge 220 thereof, and extends horizontally across the framework 200 between the side walls 202 and 204. The transmission housing 222 includes a front wall 224, a back wall 226, and a horizontal cover plate 228. The construction of the transmission housing 222 is such that all of the intersecting walls and the cover plate are sealingly connected to each other so that the housing may be filled with a suitable lubricant, and the ingress of fine dust or water to the interior of the housing is prevented.

Secured to the lower rear corners of the side walls 202 and 204 are a pair of roller supporting brackets 230 which project rearwardly from the framework 200 and support suitable journal blocks 232 which receive the opposite ends of a shaft 234. The shaft 234 carries a roller 236 which is keyed thereto and is positioned to roll along the surface of the ground which is exposed after the cutter blades of the apparatus have removed the surface layer from the ground in the manner hereinafter described.

A vertically extending partition and shaft housing assembly designated generally by reference character 240 is positioned approximately midway between the side walls 202 and 204, and extends upwardly to a position slightly below the uppermost edges 242 of the vertically extending side walls 202 and 204. The vertical partition and shaft housing assembly 240 comprises a rear portion which is constructed to include horizontally spaced, vertically extending side plates 244, a top wall 246 interconnecting the vertically extending side plates and a vertically extending rear wall 248 interconnecting the side plates 244 (see FIGURES 17 and 19). To the rear of the transmission housing 222, the vertically extending side plates 244, and the vertically extending rear wall 248 are of a length to extend to, and contact, the horizontal base plate 216. A step is provided in the partition and shaft housing assembly to permit its forward end to fit over the transmission housing 222 so that the lower edges of the forward portions of the side plates 244 are secured to the cover plate 228 of the transmission housing.

At its forward end, the partition and shaft housing assembly 240 includes a pair of converging side plates 252 which are secured at their rearmost vertical edges 254 to the forward edge of the side plates 244, and which converge to a common leading edge 256, as illustrated in FIGURE 17. The shaft housing assembly 240 thus has a V-shaped fonw-ard portion which permits the earth removed by the cutter blades, as hereinafter explained, to be cleanly and evenly divided by the converging forward walls 252 of the shaft housing assembly and to flow past the shaft housing with a minimum of frictional resistance.

The forward portion of the shaft housing assembly 240 is supported upon a transverse blade support rod 250 which extends between, and is connected at its ends to, the side walls 202 and 204 of the framework 200. A .pair of inclined lift plates 262 are welded or otherwise suitably secured at one of their end edges to the con verging forward walls 252 of the shaft housing assembly 240, and at their other end edges to the side walls 202 and 204 of the framework 200 (see FIGURES 17 and 19). The lift plates 262 terminate with their leading edges vertically spaced above the transverse blade sup port rod 260, as best illustrated in FIGURE 18. The trailing edges of the inclined lift plates 262 are secured to the forward edge of the cover plate 228 of the trans mission housing 222.

For the purpose of receiving and moving toward the rear of the framework 200, dirt moved onto the cover plate 228 of the transmission housing 222 by the lift plate 262, a pair of endless belt conveyor assemblies, designated generally by reference characters 268 and 270, respectively, are positioned between the shaft housing assembly 240 and the two side walls 202 and 204. The conveyor assemblies 268 and 270 each include a forward roller 272 keyed to a shaft 274 which is journaled at its opposite ends in the respective side plate 244 of the shaft housing assembly 240 and in the respective vertically extending side wall 202 or 204. The conveyor assemblies 263 and 2 70 each further include a rear roller 276 keyed to a shaft 278 which is journaled at its opposite ends in appropriate journal housings 279 supported by the side walls 202 and 204. The roller- s 276 and 272 of each conveyor assembly support an endless belt 280 which supports and moves the dirt from the cover plate 228 of the transmission housing 222 to the rear of the frame 200. The endless belts 230 of the conveyor assemblies 2&8 and 270 may be moved by driving either of the rollers 272 and 27s in rotation by a suitable engine or motor carried on the framework 200 or, more desirably, by a driving belt or chain extended from the gearing located in a gear box mounted on the frame 200 and subsequently described, through the shaft housing 240 to the shafts 278 which carry the rollers 276.

The power transmission system used in the em bod-iment of the invention illustrated in FIGURES 17, 18 and 19 includes a power input shaft 284 having a coupling member 286 disposed on the end thereof for coupling through a universal joint to the power takeoff of a tractor vehicle or other self propelled vehicle having a prime mover disposed thereon. A power input shaft 284 passes through a journal box 28% mounted on the forward end of the shaft housing assembly 240 and through a cylindrical, lubricant packed casing 290 into a gear box 292 which is mounted on the top of the shaft housing assembly 240 in the position best illustrated in FIG- URE 18. The journal box 288 has secured thereto a pair of upwardly extending hitch plates 294 which are provided with aligned openings or apertures 296 and which thus form a hitch bracket facilitating the connection of the central hitch link (not shown) used in a standard three point hitch connection to the framework 200.

Suitable gearing, such as a ring and pinion gear of the type illustrated in FIGURE 9, is disposed in the gear box 292 and is used to transmit the rotational motion of the power input shaft 284 to a vertically extending drive shaft 300 illustrated in FIGURE 18. The ver- .tically extending drive shaft 300 passes downwardly in walls 202 and 204 thereof, and carries a plurality of connect-ing pins 310 which are spaced at longitudinal intervals along the drive plate. The pins 310 project downwardly from the drive plate 308 and are each secured at their lower ends to a cam plate 312. The cam plate 312 is supported by anti-friction bearings in a cam plate support member 314 which extends transversely across the housing 200 and is positioned entirely within the transmission housing 222. The cam plate support member 314 is secured in the transmission housing 222 by welding or otherwise suitably attaching its opposite ends to the side walls 202 and 204 of the framework 200.

Each of the cam plates 312 has a downwardly projecting drive stud 316 secured to the lower surface thereof in a position closely adjacent the periphery of the cam plate, and the drive studs 316 are, in the case of each of the cam plates 312, disposed at different circumferential spacings around the respective cam plates from the position of attachment thereto of the connecting pins 310 secured to the lower surface of the cam plate. The peripheral or circumferential spacing of the drive studs 316 and the pins 3 10 around the periphery of the several cam plates 312 is determined by the number of cutter blades, hereinafter described, which are to be utilized. The described spacing is incorporated in the apparatus for the purpose of driving the cutter blades in ou-t-of-phase relation to each other, and the sector of the peripheral surface of the several cam plates which is interposed between the connecting pins 310 and the drive studs 316 is arrived at by dividing 360 degrees by the total number of cutter blades which are incorporated in the machine.

The drive studs 3 16 carried by the cam plates 312 are each engaged at their lower ends by an upwardly projecting keywvay formed by a pair of transversely extending, parallel guide rods 313 welded or otherwise suitably secured across the top of a pair of tubular members 3120. The tubular members 3 constitute portions of the cutter blade assembly which will next be described in detail.

The cutter blade assemblies are best illustrated in FIG- URES 18 and 19 and are designated generally by reference character 32 2. A plurality of the assemblies are employed, and in the illustrated embodiment of the inrvention sixe of the assemblies are utilized. Each of the assemblies 322 includes a cutter blade 323 having a sharpened cutting edge 323a formed at the forward or leading end thereof. The cutter blades 323 each further include a shank portion 324 which has mounted thereon at the rear edge of the cutter blades 32?: an angle iron bracket 326. The angle iron brackets 326 may be secured to the shank portions 324 of the respective cutter blades 32 3 by bolting, as illustrated in FIGURE 18, as well as by welding or other suitable means.

The forward ends of the tubular members 320 extend through the angle iron brackets 326 and are secured to the angle iron brackets so that the brackets and the cutter blades 323 carrying the respective brackets are made to move with the tubular members 320. It will be noted in referring to FIGURE 19 that a pair of the tubular members is extended through and connected to the angle iron bracket 326 on each cutter blade 323, and that each pair of tubular members 320 associated with each of the brackets 326 is provided with the guide rods 318 in which one of the drive studs 316 is caused to move, as hereinafter described. Each of the tubular members 320 extends through a sleeve 330 mounted on the outside of the forward wall 224 of the transmission housing 222. Each of the sleeves 330 includes a packing gland (not shown) which forms a fluid-tight seal around the respective tubular member 320 which passes therethrough so that the tubular member may reciprocate in the sleeve 330 without loss of lubricating fluid contained within the transmission housing 222. There is also provided .a Sylphon or bellows structure 331 which has one of its 16 ends secured around the sleeve 330 and its other end around the forward portion of each tubular member 320.

At their ends opposite the ends which are passed through and secured to the angle iron brackets 326, each of the tubular members 320 telescopingly receives a cylindrical guide rod 334 which projects inwardly from the rear wall 226 of the transmission housing 222 in the manner best illustrated in FIGURES 18 and 19. The guide rods 334 are of a length to project a major portion of the transverse distance across the transmission housing 222, and are firmly secured or anchored to the rear wall 226 of the transmission housing 222 by welding, bolting, or any other suitablevmeans. The guide rods 334 fit slidingly within the tubular members 320 for purposes of guiding these members in their reciprocating or rectilinear movement, as will be hereinafter described in greater detail.

In the operation of the embodiment of the invention illustrated in FIGURES 17, 18 and 19, the framework 200 and the various structural elements carried thereby are connected to a suitable self-powered vehicle, such as a tractor of the type illustrated in FIGURES 1 and 10, using the three point hitch connection illustrated in FIG- URE 10 with the outer hitch links being connected to the outer hitch brackets 208 and 212 provided on the side walls 202 and 204 of the framework 200. It should be pointed out that the framework 200 can be elevated by the use of the hitch brackets in the same manner as has been previously described in referring to the embodiment shown in FIGURES 10 through 16, and that the framework may be pivoted about an axis extending through the hitch brackets 208 and 212 by manipulation of the central hitch link which is attached to the central bracket formed by the vertical hitch plates 294. In this way, the excavating and pavement cutting apparatus of this embodiment may be regulated in the depth to which it penetrates the soil.

The power for driving the blade assemblies 322 in rectilinear or reciprocating motion is developed from the self-powered vehicle, and is transmitted to the blade assemblies through the power input shaft 284 which is connected through the coupling 286 to the power takeoff on the vehicle. The rotational motion of the power input shaft 284 is transmitted through suitable gearing in the gear box 292 to the drive shaft 300 which in turn drives the drive disc 304 in rotational movement. The rotational movement of the drive disc 304 is transmitted to the drive plate 308 which in turn drives each of the cam plates 312 in rotational movement. The cam plates can move freely in the support member 314, and in undergoing rotational movement, impart rectilinear motion to each pair of tubular members 320 connected to each of the cutter blades 323.

The timing of the stroke of each of the blades 323 is dependent upon the spacing of the respective drive stud 316 from the connecting pins 310 around the periphery of the respective cam plate 312, as herein-before described. As each cam plate 312 rotates, its drive stud 316 bears against the guide rods 318 and causes the tubular members 320 to move forwardly and rearwardly with respect to the frame 200. Any transverse component of movement of the drive studs 316 with respect to the tubular members 320 results in movement of the drive studs transversely in the track provided by the guide rods 318, but does not effect any lateral or transverse movement of the tubular members.

As the tubular members 320 are caused to reciprocate in the manner described, they are guided and supported by the cylindrical guide rods 334 which are telescoped within the tubular members 320. The tubular members 320 slide easily through the sleeves 330 mounted on the forward wall 224 of the transmission housing 222, and effectively push the cutter blades 323 forward from the framework into the earth during the cutting portion of the stroke, and then retract the blades toward the frame- 17 work following the cutting portion of the stroke. The several blades 232 carry out their strokes in out-of-phase relation to each other so that some of the blades are being retracted as other blades are moving forward on the cutting portion of the stroke.

In addition to the general features and salient advantages which have hereinbefore been described as characterizing the earth excavating and pavement cutting devices of the present invention, the embodiment illustrated in FIGURES 17 through 19 possesses several additional advantageous structural features which should be briefly described. In some operations in which it is desired to remove a crust or surface layer from the earth, and then redeposit this crust in substantially the same location from which it was removed in a relatively undisturbed state, it is desirable to provide a relatively low profile or slight inclination to the surfaces over which the dirt must move in passing from the front to the rear of the framework 200. The power transmission used to drive the blade assemblies 322 of the FIGURES 17 through 19 embodiment is particularly designed to permit this to be acomplished, being relatively compact and capable of confinement within a small space not requiring a large amount of room above the base plate 216.

Moreover, the manner in which the transmission is constructed and the specific mounting arrangement utilized for the tubular members 320 used to drive the blades 323 in their rectilinear motion lends itself to enclosure of the system within a fluid'tight transmission housing 222 which can be filled with a lubricant which constantly bathes all of the moving parts except the drive shaft 300 and the power input shaft 284 with the lubricant. The sealed system also has the advantage of preventing the ingress of any dirt or dust to the moving parts of the system. The manner in which the tubular members are supported and slide in the sleeves 330 and on the guide rods 334 permits the blade assemblies 322 to be operated with a minimum of frictional drag or resistance, and it will be apparent in referring to FIGURES 18 and 19 that the parts which are frictionally engaged during movement are constantly subjected to immersion in the lubricating fluid.

The conveyor assemblies 368 and 370 which are positioned toward the rear of the framework 200 and are sloped gently upwardly fnom the cover plate 278 of the transmission housing 222 also provide minimal resistance to the flow of excavated dirt through the framework and to the rear thereof. It is also to be pointed out that the converging plates 252 used in the forward portion of the shaft housing assembly 240 permit the dirt to be moved around and past the shaft housing assembly with a minimum of resistance or choking within the framework 200.

A further embodiment of the invention which is somewhat similar to that shown in FIGURES 17, 18 and 19, but employing a different power transmission system therein is illustrated in FIGURES 20 and 21. The similarity of the embodiment shown in these figures to the embodiment which has been described immediately above and depicted in FIGURES 17, 18 and 19 has prompted the use of identical reference numerals where identical parts are illustrated. It will thus be seen in referring to FIGURES 20 and 21 that the only difference in the construction of this embodiment from that illustrated in the foregoing described figures is in the manner in which the gearing and transmission elements located within the transmission housing 222 are constructed and arranged.

In FIGURE 20, the drive shaft 300 extends through the journal 302 mounted on the cover plate 228 of the transmission housing 222. The lower end portion of the drive shaft 300 passes through a bearing 348 in a gear supporting plate 350 which extends transversely across the housing 200, and is secured at its opposite ends to the side plates 202 and 204. Secured to the lower end of the drive shaft 300 in a position below the gear supporting plate 350 is a driving gear 352 which is positioned substantially midway between the side walls 202 and 204. The driving gear 352 is keyed to the drive shaft 300 for rotation therewith and engages by teeth located on its outer periphery, a pair of larger driven gears 354 disposed on opposite sides of the driving gear 352 and in transverse alignment beneath the transverse gear supporting plate 350. The driven gears 354 are but two of a plurality of driven gears corresponding in number to the number of cutter blades 323 which are employed. The driven gears 354 are disposed in a transverse line extending across the framework 200 and lying beneath the gear supporting plate 350. Each of the driven gears 354 meshes with the next adjacent driven gear so that all of the driven gears 354 are driven from the drive gear 352 located in the center of the framework 200 and keyed to the drive shaft 300. Each of the driven gears 354 is supported on a stub shaft 355 which is journaled in a suitable bearing carried by the drive gear support plate 350. The driven gears 354 are also preferably movably supported by suitable anti-friction bearings on a transverse lower support plate 360 which extends across the framework 200 and is secured at its opposite ends to the side walls 202 and 204.

Depending downwardly from the lower surface of each driven gear 354 is a drive stud 356' which is radially offset from the rotational axis of the respective driven gear 354. The drive studs 356 are circumferentially offset from each other in their relation to the rotational axes of the several driven gears 354, and it is this circumferential spacing of the several drive studs 356 which permits the cutter blades 323 to be reciprocated in outof-phase relation to each other. As in the case of the drive studs 316 provided in the embodiment of the invention illustrated in FIGURES 17, 18 and 19, the drive studs 356 attached to the driven gears 354 and in the embodiment of the invention under discussion engage a trackway formed by a pair of transversely extending guide rods 318 which are connected to the upper surfaces of the pair of tubular members 320 used to drive the blades 323.

The operation of the embodiment of the: invention illustrated in FIGURES 20 and 21 is substantially identical to that described in referring to the embodiment of FIGURES 17, 18 and 19. The advantage of the former embodiment, however, is that the construction of the transmission permits even a lower profile dirt supporting and moving surface to be achieved, and thus permits less disturbance of the earth when it is to be returned to its former position in certain types of agricultural opera tions. The power transmission structure used in the embodiment of the invention illustrated in FIGURES 20 and 21 functions by taking the rotational power input delivered by the drive shaft 300 and transmitting this to rotational movement of the driven gears 354 as they are driven by the driving gears 352. As the driven gears 354 rotate, their respective drive studs 356 engage the guide r-ods 318 and cause the various pairs of tubular members 320 included in the blade assemblies 322 to undergo a reciprocating motion, causing the blades 323 to bite into the earth in the manner hereinbefore described.

A different type of power transmission system used to drive the cutter blades in reciprocating movement is illustrated in FIGURES 22 and 23 of the drawings. This power transmission system is particularly useful in the earth evacuating and pavement cutting apparatus of the invention in that it permits a dirt supporting surface of very low profile to be obtained in the apparatus, and also facilitates synchronization between the speed at which the self-powered vehicle towing the cutter blade carrying framework is moved, with the rate at which the cutter blades per se are reciprocated. An advantage of such synchronization is to permit the machine to be used with maximum effectiveness in varying types of soils, or for removing surfacing materials of varying hardness and consistencies. For example, in some instances it may be desirable to have the self-powered vehicle moving in the direction of travel of the apparatus at substantially the same linear rate of speed as the blades are moved forward in their cutting stroke, and retracted toward the framework following the cutting stroke. In this way, the relative movement of the blades with respect to the earth during the retraction portion of the stroke is zero and no frictional drag is imposed upon the machine as a result of the necessity for the blades to move backwardly or rearwardly through accumulated earth, and in scraping, frictional engagement with the exposed surface of the earth from which the upper layer has been removed.

Referring initially to FIGURE 22, a hydraulic fluid reservoir 380 is connected by a conduit 381 to a hydraulic pump 382 which is powered by a power input shaft 384 adapted to be connected to the power takeoff on the selfpowered vehicle or tractor (not shown). A suitable power output shaft 386 is connected through suitable power transmission linkage (not shown) to the power input shaft 384 and is extended from the hydraulic pump 382 to a variable speed transmission housing 388.

The variable speed transmission housing 388 encloses adjustable gearing (not visible) which permits the rotational movement of the power output shaft 386 to be transferred to a speed control shaft 390 through step-u or step-down transmission gearing which can be adjusted by use of a governor screw 392 to permit the revolutions ratio between the power output shaft 386 and the speed control shaft 390 to be varied as may be desired for purposes hereinafter explained in greater detail. The speed control shaft 390 extends through a fluid-tight bearing 394 provided in one of the end walls 396 of a manifold housing 398. The opposite end of the speed control shaft 390 is journaled in the opposite end wall 396 of the manifold housing 398 to permit the speed control shaft to be rotated in the manifold housing.

The speed control shaft 390 carries a solid drum 400 which is keyed to the speed control shaft for rotation therewith. The drum 400 is formed with a plurality of fluid injection and fluid discharge ports extending diametrically through the drum, with the fluid injection ports being designated by reference characters 402, 404, 406 and 408. The fluid discharge ports are designated by reference characters 410, 412, 414 and 416. It will be noted that the fluid injection and discharge ports 402 through 416 which are provided in the drum 400 extend through the drum at different angles and have variously positioned openings on the periphery of the drum as shown in FIG- URES 22 and 24. Each adjacent pair of fluid injection and discharge ports, such as, for example, the ports 402 and 410, have openings on the periphery of the drum 400 which extends through arcs of 90 and are offset from each other in a circumferential direction by 90 (see FIGURES 24a-24f). The purpose of this arrangement will be subsequently explained.

The manifold housing 398 encloses a cylindrical drum housing 420 which sealingly surrounds the drum 400. The manifold housing 398 also includes a partition 422 which divides the portion of the manifold housing 398 outside the drum housing 420 into a discharge manifold space 424 and an injection manifold space 426. The injection manifold space 426 is placed in communication with the interior of the drum housing 420 by a plurality of tubular injection passageways 430, 432, 434 and 436 which correspond in number to the number of cutter blades used in the apparatus. A conduit 438 interconnects the injection manifold space 426 with the hydraulic pump 382 and a conduit 440 interconnects the discharge manifold space 424 with the reservoir 380.

The drum housing 420 is provided with a plurality of fluid discharge passageways 446, 448, 450, and 452 which place the interior of the drum in communication with the discharge manifold space 424. The fluid injection passageways 430-436 are positioned in coplanar alignment with the fluid discharge passageways 446-452, and the several passageways are longitudinally aligned with the transverse planes through the drum 400 which contain the respective fluid injection ports 402-408 and fluid discharge ports 410-416.

Disposed on the opposite side of the drum housing 420 from the injection and discharge passageways 430-452, and in coplanar alignment therewith, are a plurality of fluid injection and discharge conduits 402a-416a, each of which communicates with the interior of the drum housing 420. The fluid injection and discharge conduits are numbered according to the respective fluid and discharge ports with which they register during rotation of the drum 400. Thus, the fluid injection conduit 402a registers with the fluid injection port 402, the fluid discharge conduit 410a registers with the fluid discharge port 410, the fluid injection conduit 404a registers with the fluid injection port 404, etc. The period of registry or communication is in each case equal to one-fourth the period of one revolution of the drum 400, and the communication is established between each port and its respective injection or discharge conduit twice during each revolution of the drum. The circumferential spacing of degrees between the peripheral openings of the discharge ports 410-416 from the peripheral openings of the injection ports 402-408 (between each adjacent pair thereof) assures that upon completion of the period of communication between an injection port and its aligned injection conduit, the period of communication between the adjacent discharge port and its aligned discharge conduit will be commenced.

The fluid injection conduits 402a-408a, and fluid discharge conduits 410a-416a are connected at their ends opposite the ends entering the drum housing 420 to a piston housing designated generally by reference character 460. The piston housing 460 is partitioned or divided into a plurality of piston chambers 462, 464, 466, and 468 by a plurality of transversely extending partitions 470, 472, and 474 with the number of piston chambers provided being equal to the number of cutter blades which are to be used in the apparatus. Mounted within each of the piston chambers 462-468 for reciprocating movement therein is a piston 476. Each of the pistons 476 is generally rectangular in configuration and carries studs or protuberances 476a at each of its ends which slidingly engage guide slots 479 formed in the respective partitions 470- 474 with which the ends of the respective piston are in contact. This arrangement of the mounting of the pistons 476 is best illustrated in FIGURE 23. The peripheral surfaces of the pistons 476 are provided with a rubber gasket 481 or other suitable sealing member to prevent by-pass of fluid by the piston during operation of the apparatus.

The transverse partitions 470 and 474 are each provided with an air vent port 477 disposed in the forward portion thereof so as to permit the air located in the piston chambers 462-468 on the forward side of the pistons 476 to be vented into the next adjacent piston chamber during the cutting stroke of the pistons, as hereinafter described. Connected to each of the pistons 476 and extending through the forward wall 478 of the piston housing 460 are a pair of piston rods 480 which are secured to an angle iron or flange 482 bolted, welded, or otherwise suitably secured, to the shank portion 484 of a cutter blade designated generally by reference character 486. Thus, each of the cutter blades 486 is driven through two piston rods 480 by one of the pistons 476 contained in each of the piston chambers 462-468.

The operation of the power transmission system depicted in FIGURES 22-24 commences when the hydraulic pump 382 is energized by power delivered thereto from the power takeoff of the tractor via the power input shaft 384. Simultaneously with the actuation of the hydraulic pump 382, the power output shaft 386 is caused 2.1 to rotate. It should be pointed out that the power output shaft 386 may be merely an extension of the power input shaft 384, or the two shafts may be connected by a suitable kinematic chain which does not interfere with the operation of the hydraulic pump 3 82.

As the hydraulic pump 382 is actuated, hydraulic fluid is drawn from the reservoir 380 via the conduit 381 and is circulated through the conduit 438 from the hydraulic pump to the injection chamber 426 of the manifold housing 3-98. Hydraulic power fluid contained within the injection manifold space 426 is passed through one of the injection passageways 430-436 at a time when the corre sponding injection port 402-408 in the drum 400 is aligned therewith.

It has been previously pointed out that the injection ports 402-408 in the drum 400 are each provided with opposed peripheral openings on the drum which each extend over 90 degrees of the circumference of the drum. The injection ports thus each become aligned and in communication with their respective injection passageways 430-436 twice during each rotation of the drum, with each period of communication being equal to one-fourth the total period of one drum revolution. The circumferential arrangement of the injection ports 402-408 and discharge ports 410-416 is such that, for example, when the injection port 402 becomes aligned with its respective injection passageway 430, the discharge port 410- which is paired with the injection port 402 is out of alignment with both its respective discharge passageway 446 and its respective discharge conduit 410a. It will thus b seen that hydraulic power fluid is injected into the piston chamber 462 via the injection passageway 430, injection port 402, and injection conduit 402a at this time, but no hydraulic power fluid is permitted to leave the chamber 462 by reason of the non-alignment of the discharge port 410 with the discharge conduit 410a and the discharge passageway 446.

The piston 476 in the piston chamber 462 is thus driven forward to cause the blade 486 carried by its piston rods 480 to be driven into the earth ahead of the excavating apparatus. Air ahead of the piston is vented through the air vent port 476 into the adjacent piston chamber 464, and thus forces the piston 476 carried therein rearwardly or into a retraction stroke. It is thus necessary that the discharge port 412 be aligned with its respective discharge conduit 41 2a and discharge passageway 448 during a major portion of the cutting stroke of the piston 476 located in the piston chamber 462. Stated diiferently, the discharge port 412 is passed through the drum 400 at substantially the same angle, and opens at both ends over the same sector of the periphery of the drum, as the injection port 402 so that hydraulic power fluid contained within the piston chamber 464 may be discharged therefrom at the time that hydraulic power fluid is being introduced to the piston chamber 462.

Upon completion of the cutting stroke of the piston 476 located in the piston chamber 462, the injection port 402 will move out of registry or communication with its respective injection conduit 402a and injection passageway 430 so that the flow of hydraulic power fluid to the piston chamber 462 is interrupted. Just as the injection port 402 moves out of registry with the injection conduit 402a after 90 degrees of rotation of the drum 400, the discharge port 410 is moving into registry with the discharge conduit 410a and the discharge passageway 446. The piston 476 in the piston chamber 462 is thus ready to be retracted, and to discharge hydraulic fluid from the piston chamber 462 through the discharge conduit 410a, the discharge port 410, and the discharge passageway 446 into the manifold discharge space 424.

At the same time that the discharge port 410 moves into communication with the discharge conduit 410a and the discharge passageway 446, the injection port 404 is moving into communication with the injection conduit 404a and the injection passageway 43 2. Hydraulic power fluid can thus at this time be admitted to the piston chamher 464 from the manifold injection space 426 and can drive the piston 476 contained therein forward in a cutting stroke. The flow of air through the air vent port 476 is reversed and, combined with the resistance offered by the dirt ahead of the excavating apparatus to the movement of the blade 484 carried by the piston 476 located in chamber 462, causes this piston to move rearwardly and force hydraulic power fluid out of the chamber 462 and into the manifold discharge space 424 via the discharge conduit 410a, the discharge port 410 and the discharge passageway 446.

The manner in which the remaining two pistons located in the piston chambers 466 and 468 are synchronized in their movements is substantially identical to that which has been described with respect to the pistons located in piston chamber- s 462 and 464. It should be pointed out, however, that the injection port 406 is set on a different angle, and its openings in the cylinder 400 include different circumferential angles on the drum, than either of the injection ports 402 or 404, and the same is true of the injection port 408. The discharge ports 414 and 416 also extend at an angle with respect to the discharge ports 410 and 412. The effect of this angular arrangement is to cause the blades 486 carried by the pistons disposed in the piston chambers 466 and 468 to undergo the cutting and retraction phases of their strokes at different times from the cutting and retraction strokes of the blades carried by the pistons 476 located in the chambers 462 and 464. Thus, the out-o f-phase cutting action of the cutter blades which has been hereinbefore described in referring to other embodiments of this invention is attained in the hydraulic drive system depicted in FIG- URES 22, 23 and 24.

As fluid is sequentially discharged through the respective discharge conduits 4l0a-416a, discharge ports 410-416 and discharge passageways 446-452, the hydraulic power fluid accumulating in the manifold discharge space 324 returns to the power fluid reservoir 380 by way of the discharge conduit 440. The cycle of the hydraulic power fluid is thus completed.

An important aspect of the type of drive system illustrated in FIGURES 22 and 23 as incorporated in the earth excavating and pavement removing apparatus of the present invention is the ability to synchronize the linear speed of the cutter blades 486 during their reciprocation with the forward movement of the self-powered vehicle which moves the framework carrying the transmission apparatus and blade assemblies along the ground during operation of the device. With a given speed of rotation of the power input shaft 384 as developed from the power takeoff on the tractor, the tractor will move at a corresponding linear speed or rate of advance over the surface of the ground. The power output shaft 386 will also be correlated to the speed of the tractor, and will increase or decrease in rotational speed as the speed of the tractor is increased.

The rate at which the cutter blades 486 are reciprocated by the hydraulic power fluid will, however, be determined by the rotational speed of the power output shaft 306, and by the speed at which this shaft is permitted to drive the speed control shaft 390. By a proper adjustment of the governor screw 392, the gear ratio between the shafts 386 and 390 may be varied to vary the speed of the speed control shaft 390 and thus vary the speed of rotation of the drum 400. By varying the speed of rotation of the drum 400, the period of time over which the several injection ports 402-408 and discharge ports 410-416 are sequentially in communication with their corresponding injection conduits 402a-40i8a and discharge conduits 410a-416a, and also the corresponding injection and discharge passageways, can be varied as desired. Thus, the length of the strokes of the blades 486 can be controlled and, provided the hydraulic pump 382 develops suificient power, the speed of the stroke of each of the blades 486 can also be controlled. This

Claims (1)

1. 35.EXCAVATING APPARATUS FOR REMOVING A SURFACE LAYER FROM THE EARTH COMPRISING: A PRIME MOVER; A POWER TAKEOFF FROM SAID PRIME MOVER; A FRAMEWORK HAVING A TOP PORTION, A FORWARD PORTION, A REAR PORTION AND A GROUND ENGAGING PORTION; A PAIR OF OUTER HITCH BRACKETS MOUNTED ON THE FORWARD PORTION OF SAID FRAMEWORK ADJACENT THE SIDES OF SAID FRAMEWOFK AND IN HORIZONTAL ALIGNMENT WITH EACH OTHER; A CENTRAL HITCH BRACKET MOUNTED ON SAID FRAMEWORK TOWARD THE CENTER THEREOF AND VERTICALLY OFFSET FROM THE LINE OF HORIZONTAL ALIGNMENT OF SAID OUTER HITCH BRACKETS WHEREBY SAID FRAMEWORK CAN BE PIVOTED ABOUT A HORIZONTAL AXIS EXTENDING THROUGH SAID OUTER HITCH BRACKETS BY A HITCH LINK CONNECTED TO SAID CENTRAL HITCH BRACKETS; ACTUATING MEANS CONNECTED TO SAID HITCH BRACKETS FOR ACTUATING SAID HITCH BRACKETS TO MOVE SAID FRAMEWORK RELATIVE TO A PLANE SUBSTANTIALLY COPLANAR WITH THE SURFACE OF THE GROUND OVER WHICH SAID EXCAVATING APPARATUS IS MOVED; A PLURALITY OF CUTTER BLADES MOVABLY MOUNTED ON THE FORWARD PORTION OF SAID FRAMEWORK IN ALIGNMENT WITH THE GROUND ENGAGING PORTION THEREOF; DIRT SUPPORTING MEANS EXTENDING UPWARDLY AND REARWARDLY IN SAID FRAMEWOFK FROM A LINE IN JUXTAPOSITION TO THE UPPER SURFACE OF SAID CUTTER BLADES TO RECEIVE MATERIAL SEVERED BY SAID CUTTER BLADES AND SUPPORT AND LIFT SAID MATERIAL AS IT MOVES REARWARDLY WITH RESPECT TO SAID FRAMEWORK; AND POWER TRANSMISSION MEANS ON SAID FRAMEWORK AND HAVING AN INPUT END CONNECTED TO SAID POWER TAKEOFF AND AN OUTPUT END CONNECTED TO SAID CUTTER BLADES FOR RECIPROCATING AT LEAST TWO OF SAID CUTTER BLADES ON SAID FRAMEWORK IN OUT-OF-PHASE RELATION TO EACH OTHER AND IN A DIRECTION OF MOVEMENT ADVANCING FROM, AND RETURNING TO, THE FORWARD PORTION OF SAID FRAMEWORK, SAID POWER TRANSMISSION MEANS INCLUDING TIMING MEANS ADAPTED TO MOVE AT LEAST ONE OF SAID BLADES FORWARDLY WITH RESPECT TO SAID FRAMEWORK AT A DIFFERENT TIME THAN THE TIME AT WHICH ANOTHER OF SAID BLADES IS MOVED FORWARDLY WITH RESPECT TO SAID FRAMEWORK, SAID TIMING MEANS BEING DISPOSED BENEATH SAID DIRT SUPPORTING MEANS AND TO THE REAR OF SAID CUTTER BLADES.

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