US3559545A - Earth tamper - Google Patents

Abstract

Earth tamper with a main frame having spaced, reinforced cross members with two trunnions extending normal to the cross members and parallel to a central tongue. A perimeter subframe carrying two tamper wheels is pivotally mounted on each trunnion permitting subframe oscillations when compacting uneven grades. The subframes shift axially between the cross members and along the trunnions when travel direction is reversed placing in engagement alternate sets of force transfer members on main and subframe minimizing bending moments upon tamper wheel axles. Four, independently rotatable tamper wheels of spaced, open ring, spoked construction with sheepsfoot elements projecting outwardly from the ring facilitate short radius turning of the unit without disturbing compacted material. Nonengaging cleaner bars are set on the subframe between adjacent wheel rings. A second form of earth tamper includes only one perimeter subframe mounted upon a trunnion with main frame. Two, independently rotatable tamper wheels with cleaners are mounted on the subframe.

Description

United States Patent Fred Joseph Caron [72] Inventor Primary Examiner.lacob L Nackenoff Citr s H ig t- C Attorney-Flehr. Hohbach, Test, Albritton & Herbert [21] Appl. No. 844,465 [22 Filed July 24, 1969 [4S] Patented Feb. 2, 1971 ABSTRACT: Eanh tamper with a main frame having spaced, 73 A i Caron Compactor C reinforced cro'ss members with two trunnions extending nor- West Sacramento, Calif. mal to the cross members and parallel to a central tongue. A acorporation f C lif ni perimeter subframe carrying two tamper wheels is pivotally mounted on each trunnion permitting subframe oscillations when compacting uneven grades. The subframes shift axially between the cross members and along the trunnions when travel direction is reversed placing in engagement alternate I 54] EARTH TAMPER sets of force transfer members on main and subframe minimiz- 10 Claims 8 Drawing Figs. ing bending moments upon tamper wheel axles. Four, independently rotatable tamper wheels of spaced, open ring, Cl 94/50 spoked construction with sheepsfoot elements projecting outl l Cl E016 19/24 wardly from the ring facilitate short radius turning of the unit of Search without disturbing compacted material Nonengaging cleaner bars are set on the subframe between adjacent wheel rings. [56] References A second form of earth tamper includes only one perimeter UNlTED STATES PATENTS subframe mounted upon a trunnion with main frame. Two, in- 2,437,524 3/ 1948 Harrison 94/50 dependently rotatable tamper wheels with cleaners are 2,587,463 2/ l952 Guignard 94/50 mounted on the subframe.

28 s 3| 58 l3 9 27 I6 Uh [1 lEq l7 I I U \L I l U L6 v SHEET 2 BF 4 n 1 I I!!! 1/ FI IG 5 INVENTOR. FRED JOSEPH. CARON ATTORNEYS v PATENTEU FEB? 1911- SHEET 0F 4 FlG '8 INVENTOR. FRED JOSEPH CARON FIGJ BY 7 I ATTORNEYS EARTH TAMPER BACKGROUND OF THE INVENTION This invention concerns improvements to earth tampers and particularly earth tam'pers of the sheepsfoot type.

Sheepsfoot rollers, in general, were designed and adapted to be propelled by track laying tractors. This combination is characterized in operation by moderate to low compaction speeds and avoidance of short radius turns where the sheepsfoot could p|ow out compacted material already in place.

The advent of the rubber-tired tractor characterized by relatively high working speeds and short radius turning created the need for a compatible sheepsfoot tamper which would work at a higher speed and which would be turned in a short radius without destructive effect to the compacted material in place.

The predominant design of the prior art earth tampers or sheepsfoot rollers comprised a large hollow steel drum serving as both a ballast compartment for wet sand or water, andas a support for the outwardly projecting sheepsfoot shanks and caps. The drum in certain arrangements had its own subframe mounted, in turn, to a main or principal frame. Cleaner mechanisms were placed close to the drum surface between the sheepsfoot element to remove clay and other materials which tended to bridge over. This raker bar construction frequently imposed a braking effect due to the rakers being operated in close drag-contact with the solid drum.

For transport of earth tampers of this variety from one job site to another, different schemes were employed. Certain of the earth tampers of narrow dimensions were transported without disassembly on machinery carriers and the limitation of highway load widths determined the maximum size of the tamper. Other earth tampers were partially disassembled for transport and reassembled at the new job site. Sheepsfoot of this construction were of larger overall width than the former and disassembly was usually achieved by disassembly of the principal framework.

Where the drum type sheepsfoot roller was employed, transport of the unit required that the ballast be drained from the drum and left at the first job site.

SUMMARY OF THE INVENTION AND OBJECTS The invention, in summary, comprises a main frame for an earth tamper including a longitudinally extending, central tongue member with crossmembers'rigidly secured thereto extending laterally from each side thereof. Two wheel-frame guide members or trunnions are arranged parallel to the central beam member, each guide member extending between and rigidly secured to the spaced crossmembers, Two wheelframe assemblies are provided, one mounted on each wheelframe guide member and each assembly includes a generally rectangular perimeter frame mounting two independently rotatable earth tamping wheels with wheel cleaner extending between the subframe and wheels. The wheel frame assembly is free to pivot about the wheel guide member when traversing uneven ground and the wheel-frame assembly is shiftable longitudinally along the axis of the guide member during change of direction of travel. Complementary mounted pusher and reaction members are arranged on the main frame and wheel frame, respectively, to transfer motive forces from the main frame to the wheel-frame assembly.

An object of this invention is to provide an improved earth tamper which is readily disassembled for transport from one job site to another.

Another object of the invention is to provide an earth tamper of the sheepsfoot type having a plurality of independently rotatable, open-ring wheels upon which are mounted sheepsfoot tamping elements, the wheels being mounted in groups of two upon a subframefree to oscillate or pivot about an axis parallel to the direction of travel.

Another object of the invention is to provide an earth tamper of the type described wherein the motive forces are applied through a central tongue member and are distributed therefrom to wheel mounting subframes in a manner which minimizes bending moments at the wheel axles.

Another object of the invention is to provide an improved earth tamping wheel of the sheepsfoot type including a wheel cleaner arrangement permitting deep penetration of the tamping elements while minimizing braking and drag effects between the cleaner mechanisms and the wheels being cleaned.

A further object of the invention is to provide an improved earth tamper having a double-oscillation suspension of multiple, free wheeling, compaction wheels, which tamper unit may be turned within its own width without increased draft, plowing, or disturbing compacted material already in place and which is complementary in operating characteristics to quick turning, rubber-tired tractors.

Further objects and features of the invention will appear from the drawings taken in conjunction with the specification.

BRIEF DESCRIPTION OF DRAWINGS FIG. I is a plan view of an earth tamper of the present invention.

FIG. 2 is an elevation view, partially broken away, of the earth tamper shown in FIG. I.

FIG. 3 is an enlarged, fragmentary sectional view along the line 3-3 in FIG. 1.

FIGS. 4 and 5 are each sectional views like FIG. 3 but taken respectively along the lines 44 and 5-5 of FIG. 1.

FIG. 6 is an enlarged transverse view, partially fragmentary, along the lines 6-6 of FIG. 1 showing one set of two tamper wheels operating on a horizontal grade while the other set operates on an inclined grade.

FIG. 7 is a plan view of a second form of an earth tamper of the present invention.

FIG. 8 is an elevation view of the earth tamper shown in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An earth temper 10 of the present invention is shown generally in FIGS. 1 and 2 and comprises a main frame 11 upon which are mounted two, substantially identical wheelframe assemblies I2 and 13.

The main frame 11, FIGS. I-6, includes a longitudinally extending central beam or tongue member 14 which is provided at the forward end with a hitch 16 for connection to a tractor (not shown) for moving the tamper I0 across the fill. The opposite end of the tongue or beam 14 is provided with a pusher plate 17 which serves to protect the end of the beam from aggressive thrust imparted by vehicles pushing against the plate 17. The central beam or tongue member 14 extends the full length of the main frame and is the principal load carrying member on' the earth tamper I0. The central beam 14 may be fabricated by joining together, toe-to-toe, a pair of l2- inch, 45-pound structural channel members 18, FIG. 3, which at the forward end'may be supplemented by a further pair of 12 inch channels 19 set back-to-back to the channels I8. Being of substantial section, the tongue or beam member I4 is capable of withstanding substantial forces which may be imparted to it during earth working operations of the tamper without noticeable deformation.

Box-sections, crossmembers 2I24 are rigidly secured, as by welding, to the sides of the tongue member and project outwardly therefrom in a transversely aligned, longitudinally spaced apart relationship. A brace member 26 is rigidly secured between an outer end of each crossmember and the tongue member 14, as in FIG. 1. Acting together, the brace member 26, central beam I4, and the associated crossmember serve as a horizontal platform to support a ballast element 27, preferably in the form of a wedge-shaped concrete block 27 equipped with a lifting hook 28 Ballast 27 may be supplied to the earth tamper 10 in various amounts depending upon the specifications and requirements of the work being performed. The ballast maintains its position on the main frame solely from the action ofgravity and friction between the ballast and frame members. This arrangement of ballast is distinct from the employed in prior sheepsfoot tampers wherein the hollow drum was usually filled with water or wet sand to obtain the desired weight for compaction.

A wheel-frame guide member or trunnion 29 extends between the erossmembers 21-23. and between the crossmcmbers 22-24. The trunnion is rigidly secured to the crossmembers as shown in FIGS. 4 and 5. The guide member 29 or trunnion is cylindrical in cross section and may be fabricated from structural tubing sized in accordance with its function of supporting and guiding the wheel-frame assembly described below.

Being that the wheel-frame assemblies 12 and 13 are virtually identical, the description below will apply to both. Each wheel-frame assembly includes a generally rectangular perimeter frame 31, FIGS. 1, 2 and 6, within which are mounted two tamper wheels of open ring, spoked configuration, comprising an outboard wheel 32 and an inboard wheel 33. As shown, the wheel 32 includes three spaced rings and the wheel 33, four rings, although the number of rings may be varied depending on the width of the machine required.

The perimeter frame 31 may be fabricated from structural box members and includes three longitudinally extending members 34 (FIG. 6), two being arranged on the sides and one being somewhat centrally disposed in the region of connection with the trunnion 29, FIGS. 1 and 6. The end members 36 are rigidly secured to the long members 34. Pillow blocks 37 are mounted in midspan of the long members 34, for receiving the ends of an axle 38 of the tamper wheel. Thus, a pair of pillow blocks 37 on the long members 34 support a tamper wheel which rotates independently of the other tamper wheels.

The arrangement of the wheel-frame assembly and the main frame 11 is such as to permit eaeh wheel frame assembly to shift longitudinally along the guide members 30 when the tamper changes direction. Further, each wheel-frame assembly may pivot about the axis of the guide members, FIG. 6, to permit more effective tamping or earth treatment on berms and inclines. To this end, the perimeter frame 31 has a length somewhat shorter than the distance between the cross arms 21-23 and 22-24, 24, as shown in FIG. 1 of the main frame. The perimeter frame 31 is united for rapid disassembly to the main frame by the connector 41.

The connector or split coupling 41, FIGS. 4 and 5, is mounted to each wheel-frame end member 36 by two plates 42, 43 arranged respectively on the outside and inside of the end member 36, and placing the axis of the connector 41 a distance below the end member 36. It will be also appreciated here that the axis or the connector 42 and guide member 29 is arranged below the axis of the tamper wheels which are mounted in pillow blocks arranged on the member 34, as is evident from FIG. 6. Thus, the wheel-frame assembly pivots about an axis arranged below the axis of rotation of the tamper wheels.

The connector or split coupling 41 cooperates with the wheel-frame guide member 29 to permit the wheel-frame assembly to pivot about the axis of the guide member and to slide axially therealong. To facilitate these functions, the internal surface of the split coupling is provided with suitable bearing materials well known in the art. The connector or split coupling provides for ready disassembly of wheel-frame assembly from the main frame. To this end a lower or removable portion 44 of the coupling is dismountableby unsecuring the fasteners or bolts 43. Then the subframe assembly, including tamper wheels, may be vertically lifted from the main frame for transporting the earth tamper over the highway in a compact condition.

Referring to 'FIGS. 3-5, to transfer motive forces from the central beam or tongue 14 to the wheel-frame assemblies, each crossmember 21-24 is equipped, adjacent its ends, with two pusher members 46-47. The pusher member 46 is arranged adjacent to the guide member and the pusher member 47 is disposed inwardly adjacent to the central beam member 14. The pusher members 46,47 are rigidly secured to the crossmembers on the side thereof facing the perimeter wheelframe and extend upwardly for engagement therewith. A gusset 48 rigidly secured to the crossmcmber and pusher member reinforces each pusher member longitudinally of the main frame.

Complementary arranged reaction members are included on the perimeter frame of the wheel-frame assembly. The outer plate 42 of the connector 41 serves as one reaction member, and laterally inwardly thereofa plate 50, FIG. 6, is positioned for engagement with the pusher member 47 to serve as a second reaction member.

When the earth tamper I0 is towed or pushed to the left as viewed in FIGS. 1 and 2, there is a space 49 between the reaction and pusher members adjacent to the forward portion of the tamper, FIG. 4. The reaction and pusher members to the rear of the tamper arc in contact as shown in FIG. 5. Thus, the motive forces are carried from the tongue member 14 to the crossmembers 23, 24 and the pusher members 46, 47 of the main frame to the wheel-frame subassemblies, the reaction members of which engage the pusher members 46, 47. When the earth tamper 10 is moved in the opposite direction, the wheel-frame assembly shifts longitudinally along the guide member 29 so that the conditions illustrated in FIGS. 4 and 5 are reversed. An important advantage of this arrangement is that the towing forces are taken by the main and subframes without applying *bending stresses to the wheel axles.

The wheel-frame assembly may also oscillate aboutthe axis of the guide member, FIG. 6, so that one or both wheel assemblies may be inclined with respect to the main frame; Stop means 51 are provided between the central beam member 14 and the wheel-frame assembly, FIGS. 1 and 6, and includes a reinforced cutout in the central beam 14 supplied with inclined plates 52 which are positioned to be engaged by the inboard pillow blocks 37 when the frame assembly is tilted upwardly as shown in FIG. 6. When the frame assemblies are tilted oppositely, e.g., the inboard members 34 being elevated over the outboard members 34, the inboard long side members 34 of the wheel-frame assemblies engaged and thus limit upward movement or tilting action of the subassemblies and protects the inboard wheel from engagement with the central beam 14.

As may be seen from FIG. 1, the outboard tamper wheels 32 are mounted for rotation substantially entirely outwardly of the main frame and the inboard wheels 31 rotated in a zone disposed entirely inwardly of the compass of the main frame. Each wheel is independently joumaled to the perimeter frame assembly and thus is free wheeling so as to permit the earth tamper 10 to be turned within its own radius without increased draft, plowing, or disturbing compacted material already in place. This feature makes the earth tamper 10 particularly adaptable to darn work and areas where a limited working space is available. The earth tamper is also compatible with the high speeds and quick turning characteristics of rubberwheeled tractors.

Each tamper wheel includes an axle 56 mounted with its opposite ends in one of the pillow blocks 37 and the axle is rigidly secured to.a cylindrical hub member 57. A plurality of axially spaced apart rings 58 are rigidly secured to the hub 57 by an array of radially extending spokes 59 which preferably are of cylindrical cross section and of a diameter substantially identical to the ring width to avoid bridging and collection of material between adjacent spokes.

Earth tamping feet 61 including a shank 62 and cap-63 are secured upon and project outwardly from the peripheral surface of each of the rings 58 in evenly spaced relation. The tamping feet 61 on adjacent rings may be staggered relative to each other.

Raker bars 66 are fixedly secured to the end members 36 of the perimeter frame and extend through the gaps between adjacent rings on the wheels to prevent rocks, clay and other unwanted material from lodging there permanently. The openring sheepsfoot wheel and raker bar arrangement described allows deep penetration through soft material from the tip of the cap to the surface of the hub, without excessive rolling resistance or the possible bridging-over effect in the fill which is a common characteristic of solid-drum sheepsfoot compactors.

OPERATION When considering the operation of the earth tamper 10, it should first be assumed that the tamper is delivered to the job site in knocked-down condition for the reason that in the assembled condition the earth tamper is too large to be moved over the highways as a legal load. The main frame 11 may be unloaded from the machinery carrier and setupon blocking at a suitable height so as to receive each of the two wheel-frame assemblies 12, 13. The split coupling, or connector41, at each end of the wheel-frame assembly 12 or 13, is disassembled, if that operation has not been previously performed, by removing the lower portion 44. Each wheel-frame assembly is placed with the use of a crane or the like so that the connectors 41 engage the upper portions of the trunnions or guide members 29. Thereafter the lower portion of the coupling 44 is secured in place with the two fasteners and the tamper 10 is then ready to be connected to a tractor for work. It will be understood that the wheel-frame assemblies during transport from one site to another have mounted thereon the inner and outer tamper wheels 32, 33, and that it is unnecessary to dismount the wheels from the subframe assemblies for transport purposes. Thus, to assemble or disassemble the earth tamperlO it is necessary only to deal with eight fasteners of the four couplings or connectors 41. l

The ballast blocks 27, when such are needed, may be mounted upon the ballast platforms to achieve the compaction required by the job specification.

When the compactor is towed from rest, the pusher members 46, 47 on the main frame move forward into engagement with the reaction members 48 on the wheel frame, thus transferring the propelling forces from the main frame to the two subframes. Between the forward sets of complementary positioned reaction and pusher members there is at this time a space 49 between the main frame and wheel-frames so as to insure clearance, preventing bindingof the members which would prevent the wheel-frames from oscillating freely on the trunnions.

When the tamper 10 is turned in a short radius in a clockwise direction as viewed in FIG. 1, the forward pusher and reaction members pertaining to the wheel frame assembly 12 come into engagement while the rearwardly disposed reaction and pusher members pertaining to the wheel-frame assembly 13 are engaged. The wheels on the right-hand wheelframe assembly are each free to move in the direction reverse to the wheels in the left-hand frame, left-hand wheel-frame assembly 13. Permitting the wheels of one frame to turn independently of those of another provides the feature that the tamper 10 may be turned in a short radius without the inner wheels in the turn plowing out the previously compacted material. When the earth tamper 10 is employed upon a berm or bank such as indicated in FIG. 6, one wheel-frame with a set of compaction wheels may pivot on the wheel guides permitting the wheels to operate conforrnably on the bank, while the other compaction wheels operate on the flat portion. Similar oscillations of the wheels-frames on the wheel guides or trunnions occur as uneven grades are traversed.

SECOND EMBODIMENT of employing five axially spaced rings 58 supporting the tamping feet 61, previously described.

The main frame 71 includes a forward tongue member 76 fixed secured to the transversely extending cross members 77, 78 and braced with respect thereto by the struts 79. The forward portion of the tongue members 76 is equipped with a hitch assembly 81. Being generally rectangular in outline. the main frame includes'side frame members 82, 83 and rear crossmembers 84. A wheel-frame guide member or trunnion 86 extends from the rear cross member 84 to the tongue member 76.

The wheel-frame assembly 72 is constructed and arranged substantially similar to the wheel-frame assembly 13, prcviously described, with the exception of the location of the split coupling connector members 85 which are disposed in midspan of the end members 87 of the subframe. The other details of the connector 85 are identical to that shown in FIGS. 4 and 5. Pusher members 91 are arranged on the main frame crossmembers in confronting relationship to the reaction members 92 disposed on the end members of the peripheral frame of the wheel-frame assembly and function similar to the relationship described previously in relation to FIGS. 4 and 5. Raker or cleaner bars 66 are also provided on the subframe extending through the gaps between adjacent rings 58.

The earth tamper 70 is particularly satisfactory on smaller operations and may be equipped with ballast blocks 93 similar to those described above. The wheel subframe assembly oscillates about the guide member or trunnion 86 and the two tamping wheels 72 are each free wheeling, permitting the tamper 70 to be turned in a very small space without digging up the ground previously compacted.

It will be seen from the foregoing that there has been disclosed an improved earth tamping machine which may be readily disassembled so as to permit the wheel-frame subassemblies to be removed from the main frame and placed on a road carrier. The present tamper is of an arrangement giving a wide working track yet being transportable without exceeding the highway width limits requiring special permits for road travel. The subject earth tamper is simple and rugged in design and incorporates free wheeling characteristics for the tamper wheels so that the unit may be turned around in a small area without digging up the previously compacted fill.

While the above description has been set forth in compliance with the Patent Statutes and Rules, the invention is not limited except as defined in the following claims.

Iclaim:

1. An earth tamper comprising a main frame structure including a longitudinally extending, central tongue member, hitch means on one end of said tongue member serving to connect said earth tamper to a tractor vehicle, crossmembers rigidly secured to said tongue member extending laterally from each side of the centerline thereof at two longitudinally spaced locations, at least one wheel-frame guide member arranged parallel to said tongue member extending between and rigidly secured to said spaced crossmembers, and a wheelframe assembly mounted on each wheel-frame guide member, said assembly including a generally rectangular, perimeter wheel-frame, two compaction wheels each mounted on said wheel-frame for independent rotation, said main frame and wheel-frame assembly being dimensioned to permit limited longitudinal movement of said assembly between said spaced crossmembers, means connecting said wheel-frame guide member of said main frame and said wheel-frame assembly in a connection permitting said assembly to pivot about the axis of said guide member and to shift longitudinally thereof during change of direction of said earth tamper, and complimentary mounted pusher and reaction means on said main frame and said wheel-frame, respectively, to transfer motive forces from said main frame to said wheel-frame assembly.

2. The earth tamper defined in claim 1 wherein said pusher and reaction means are arranged in forward and rear sets at each end of said wheel-frame assembly, the forward set of said pusher and reaction means being in nonengagement during forward motion of said tamper, and the rear set being in nonengagement during rearward motion of said tamper.

3. The earth tamper defined in claim I wherein said connector means is readily disengageablc permitting ready dismounting of said wheel frame assembly from said main frame permitting shipping of said tamper over the road to another work site.

4. The earth tamper defined in claim 1 and further including at least at the forward portion of said tamper, members extending between said tongue and said crossmembcrs serving to define a ballast platform and ballast in solid form disposed on said platform.

5. The earth tamper defined in claim I wherein said wheel frame guide member is aligned with the centerline of said ton gue and member.

'6. The earth compactor defined in claim 1 wherein said main frame includes two wheel-frame guide members laterally spaced from the centerline of said tongue member and disposed parallel thereto, and two said wheel-frame assemblies mounted upon the respective guide members.

7. An earth tamper comprising a main frame structure including a longitudinally extending, central tongue member, hitch means at one end of said tongue member to connect said tamper with a tractor vehicle, pusher plate means on the other end of said tongue member to receive thrust from a pusher vehicle, crossmembers rigidly secured to said tongue member extending laterally therefrom on each side of the tongue centerline at two longitudinally spaced locations intermediate the ends of said tongue member, two wheel-frame guide members each arranged parallel to said tongue member and spaced laterally outwardly therefrom, one on each side of the tongue centerline, each guide member extending between two spaced crossmembers and being rigidly secured thereto, and two wheel-frame assemblies, one arranged on each side of the tongue centerline and disposed upon one of the wheel-frame guide members, each wheel-frame assembly including a generally rectangular, perimeter wheel-frame disposed above one of said wheel-frame guide members, connector means between said wheel-frame and its associated guide member extending downwardly from the end portions of said wheelframe, said connector means being pivotable with respect to said guide member, permitting said wheel-frame assembly to oscillate about the axis of said guide member, two compaction wheels of the sheepsfoot type mounted on each wheel-frame, each wheel being independently rotatable with respect to the other wheel about an axis arranged above the axis of said guide member, compaction wheel cleaner means mounted on said wheel-frame in operative relative to said compaction wheels, said main frame and said wheel-frame assemblies being dimensioned to permit longitudinal movement of said wheel-frame assemblies in the spaced between said crossmembers, and complementary arranged pusher and reaction means on the crossmembers of said main frame and the end members of said wheel-frames, respectively, serving to transfer motive forces from said main frame to said wheel-frame assemblies.

8. The earth tamper defined in claim 7 wherein each compaction wheel includes a cylindrical, axially extending hub, an axle including means for mounting said wheel to said wheelframe, means serving to mount said hub to said axle, a plurality of axially spaced apart rings having a diameter substantially greater than that of said hub, a plurality of cylindrical spokes rigidly mounting said rings to said hub, said rings having an axial width substantially equal to the width of said spokes, sheepsfoot compaction means arranged on said rings projecting radially outwardly therefrom, said wheel being constructed and arranged so that dull penetration for compaction is substantially unobstructed by wheel structure between laterally adjacent rings from the ends of said sheepsfoot compaction means to the outer surface of said hub.

9. Earth tamper defined in claim 7 wherein stop means are provided for limiting pivoting of said wheel-frame assemblies on said wheel-frame guide members.

10. The earth tamper defined in claim 1 wherein there is provided compaction wheel cleaner means mounted on said wheel-frame in operative relation to said compaction wheel.

Claims (10)

1. An earth tamper comprising a main frame structure including a longitudiNally extending, central tongue member, hitch means on one end of said tongue member serving to connect said earth tamper to a tractor vehicle, crossmembers rigidly secured to said tongue member extending laterally from each side of the centerline thereof at two longitudinally spaced locations, at least one wheel-frame guide member arranged parallel to said tongue member extending between and rigidly secured to said spaced crossmembers, and a wheel-frame assembly mounted on each wheel-frame guide member, said assembly including a generally rectangular, perimeter wheel-frame, two compaction wheels each mounted on said wheel-frame for independent rotation, said main frame and wheel-frame assembly being dimensioned to permit limited longitudinal movement of said assembly between said spaced crossmembers, means connecting said wheel-frame guide member of said main frame and said wheel-frame assembly in a connection permitting said assembly to pivot about the axis of said guide member and to shift longitudinally thereof during change of direction of said earth tamper, and complimentary mounted pusher and reaction means on said main frame and said wheel-frame, respectively, to transfer motive forces from said main frame to said wheel-frame assembly.

2. The earth tamper defined in claim 1 wherein said pusher and reaction means are arranged in forward and rear sets at each end of said wheel-frame assembly, the forward set of said pusher and reaction means being in nonengagement during forward motion of said tamper, and the rear set being in nonengagement during rearward motion of said tamper.

3. The earth tamper defined in claim 1 wherein said connector means is readily disengageable permitting ready dismounting of said wheel frame assembly from said main frame permitting shipping of said tamper over the road to another work site.

4. The earth tamper defined in claim 1 and further including at least at the forward portion of said tamper, members extending between said tongue and said crossmembers serving to define a ballast platform and ballast in solid form disposed on said platform.

5. The earth tamper defined in claim 1 wherein said wheel frame guide member is aligned with the centerline of said tongue and member.

6. The earth compactor defined in claim 1 wherein said main frame includes two wheel-frame guide members laterally spaced from the centerline of said tongue member and disposed parallel thereto, and two said wheel-frame assemblies mounted upon the respective guide members.

7. An earth tamper comprising a main frame structure including a longitudinally extending, central tongue member, hitch means at one end of said tongue member to connect said tamper with a tractor vehicle, pusher plate means on the other end of said tongue member to receive thrust from a pusher vehicle, crossmembers rigidly secured to said tongue member extending laterally therefrom on each side of the tongue centerline at two longitudinally spaced locations intermediate the ends of said tongue member, two wheel-frame guide members each arranged parallel to said tongue member and spaced laterally outwardly therefrom, one on each side of the tongue centerline, each guide member extending between two spaced crossmembers and being rigidly secured thereto, and two wheel-frame assemblies, one arranged on each side of the tongue centerline and disposed upon one of the wheel-frame guide members, each wheel-frame assembly including a generally rectangular, perimeter wheel-frame disposed above one of said wheel-frame guide members, connector means between said wheel-frame and its associated guide member extending downwardly from the end portions of said wheel-frame, said connector means being pivotable with respect to said guide member, permitting said wheel-frame assembly to oscillate about the axis of said guide member, two compaction wheels of the sheepsfoot type mounted on each wheel-frame, each wheel being independently rotatable with respect to the other wheel about an axis arranged above the Axis of said guide member, compaction wheel cleaner means mounted on said wheel-frame in operative relative to said compaction wheels, said main frame and said wheel-frame assemblies being dimensioned to permit longitudinal movement of said wheel-frame assemblies in the spaced between said crossmembers, and complementary arranged pusher and reaction means on the crossmembers of said main frame and the end members of said wheel-frames, respectively, serving to transfer motive forces from said main frame to said wheel-frame assemblies.

8. The earth tamper defined in claim 7 wherein each compaction wheel includes a cylindrical, axially extending hub, an axle including means for mounting said wheel to said wheel-frame, means serving to mount said hub to said axle, a plurality of axially spaced apart rings having a diameter substantially greater than that of said hub, a plurality of cylindrical spokes rigidly mounting said rings to said hub, said rings having an axial width substantially equal to the width of said spokes, sheepsfoot compaction means arranged on said rings projecting radially outwardly therefrom, said wheel being constructed and arranged so that dull penetration for compaction is substantially unobstructed by wheel structure between laterally adjacent rings from the ends of said sheepsfoot compaction means to the outer surface of said hub.

9. Earth tamper defined in claim 7 wherein stop means are provided for limiting pivoting of said wheel-frame assemblies on said wheel-frame guide members.

10. The earth tamper defined in claim 1 wherein there is provided compaction wheel cleaner means mounted on said wheel-frame in operative relation to said compaction wheel.

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