Патент USA US3085493код для вставки
April 16, 1963 a. v. CHRISTENSEN 3,085,483 COMPACTION WHEELS Filed April '7, 1958 5 Sheets-Sheet 1 INVENTOR. BRUCE V. CHRiSTENSEN BY ATTY April 16, 1963 B. v. CHRISTENSEN 3,085,483 COMPACTION WHEELS Filed April 7, 1958 5 Sheets-Sheet 2 INVENTOR. BRUCE V. CHRISTENSEN BY Wax/oz: ATTY. April 16, 1963 B. v. CHRISTENSEN 3,085,483 commcnon WHEELS Filed April 7. 1958 5 Sheets-Sheet 3 INVENTOR. BRUCE V. CHRISTENSEN BY M CWJC ATTY. April 16, 1963 B. v. CHRISTENSEN 3,085,433 COMPACTION WHEELS Filed April 7, 1958 5 Sheets-Sheet. 4 INVENTOR. BRUCE V. CHRISTENSEN BY Wayne/2% @ z/v?: ATTY. April 16, 1963 B. v. CHRISTENSEN 3,085,483 COMPACTION WHEELS Filed April 7, 1958 5 Sheets-Sheet 5 LO Q INVENTOR. BRUCE V. CHRQSTENSEN Ll. BY ATTY United States Patent 0 ” "ice 1 3,085,483 Patented Apr. 16, 1963 2 a compaction wheel or roll in which the pads of a 3,085,483 plurality of annular rows on the wheel are so propor Bruce V. Christensen, Berrien Springs, Mich., assignor to Clark Equipment Company, a corporation of Michigan Filed Apr. 7, 1958, Ser. No. 726,884 6 Claims. (Cl. 94--50) varying ground pressure. Such tamping action provides COMPACTIQN WHEELS tioned and arranged that as the wheel rolls over the surface of the ground the pad area in contact with the ground varies sharply at frequent intervals during a revo lution and provides a tamping action due to the rapidly more compaction per pass to a speci?ed depth thereby This invention relates to devices for compacting loose more effectively using the machine weight available than earth and the like, and more particularly to compaction 10 is possible with prior art rolls of the pad type, yet main wheels or rolls of the pad type. taining practically the same surface ?nish and other ad It has been demonstrated previously that compaction vantages. Reasonable buoyancy is maintained due to the wheels or rolls comprising a plurality of raised, out— rapid action, proper size and spacing of the pads and wardly curved, spaced apart pads making up a broken the increase in soil density proportional to the loading. roll surface can be utilized for compacting loose earth Another wheel of the same general construction on the and for other similar operations, such as a construction same machine may be constructed and arranged in such being in contrast to the solid roll type, sheep’s foot type a manner as to pack the earth in the unpacked areas left and other wheels and rolls of the prior art. Patent by the spacing between rows of pads and between indi 2,754,734, Gardner, dated July 17, 1956, illustrates such a pad type roll. Gardner discloses a roll in which the vidual pads in a single row, in order to provide an even more uniformly and thoroughly compacted surface after total pad area pressing against the arc of contact with 20 the material being rolled, when totalled across the width of the roll, remains constant as the roll progresses there by providing constant pressure against the material being one pass of the machine. For a clearer and more complete understanding of my invention, reference should be had to the accompanying drawing in which rolled. FIGURE 1 is a side elevation of a rolling machine The object of my invention is to provide a pad type 25 equipped with wheels embodying the present invention, roll with improved rolling characteristics which increases the compaction achieved for each pass of the roll, or, more explicitly, which increases the compaction achieved to a speci?ed depth, for each pass of the roll. Assuming that it were desired to increase the compac tion per pass at a speci?ed depth utilizing the structure taught by Gardner, there are three things which could be varied. These three possibilities are: (1) increasing the pad width, (2) reducing the ground contact area, or (3) increasing the weight on the roll. Taking the possibility of increasing the pad width FIGURE 2 is a larger side elevational view of one of the front wheels of the machine in FIGURE 1, FIGURE 3 is an end elevation of the wheel of FIG URE 2, more speci?cally a view from the front of the right front wheel, FIGURE 4 is a partial sectional view of the wheel of FIGURE 2, along the line 4—4 of FIGURE 2, FIGURE 5 is an enlarged side elevational view of one of the rear whels of the rolling machine, FIGURE 6 is an end elevation of the wheel of FIG URE 5, and FIGURE 7 is a partial sectional view of the wheel of FIGURE 5 along the line 7-7 of FIGURE 5. overcome the advantage of increased compaction result 40 Referring to the drawing, I have shown in FIGURE ing from such increase in width. Some such disad 1 a bulldozer machine 10 which is equipped also for ?rst, there is a limit to the extent to which the pad width can be increased without incurring disadvantages which vantages are discussed in the Gardner patent. Another disadvantage is that if the spaces between rows of pads are too small it may not be possible to use cleaners having teeth extending into such spaces, and it has been found that cleaners are necessary on pad type compactor rolls for some materials. The second possibility—-reducing the ground contact would be accomplished by reducing the number of an nular rows of pads on each wheel or roll, but this, of course, would have the obvious disadvantage of reducing the width covered by each pass and thus increasing the number of passes required to compact a given ground area. This possibility, that is, reducing the ground con tact area, might also result in lack of sut?cient buoyance, with the result that the pads would punch through the surface of the earth being compacted and provide a rough surface ?nish approaching that of the sheep’s foot type use as a rolling machine. This machine comprises a body portion 11 housing a prime mover such as a diesel or other internal combustion engine, along with other components necessary for propelling the machine. It is equipped with a pair of front compaction wheels 12, only one of which is visible in this view, and a pair of rear compaction wheels 14, only one of which is visible. The machine 10 includes a bulldozer blade 18 although this blade forms no part of the present invention. The machine 10 also includes an operator‘s station 20 and other components and features necesary for a machine of this type. In FIGURES 2, 3 and 4 of the drawing one of the front wheels 12 of the machine is illustrated in greater detail. 55 Each wheel 12 includes a centrally located ?at ring or annular member 20 provided with openings 22. for lug bolts for connecting the wheel 12 to the hub of the roll ing machine. It will be seen from FIGURE 4 that mem With regard to the third possibility, that of increasing ber 29 is the ‘main structural member of the wheel and 60 the weight of the machine, such a change has the dis that it has a pair of cylindrical rings 24 and 26 welded advantage of making the machine more costly and un or otherwise secured to the sides thereof. A plurality of wieldy, and it also has the disadvantage, mentioned pre spoke portions 28 are secured to one side of member 20 viously in connection with possible reduction of ground and to ring 24, while an equal number of spoke portions contact area, of causing the pads to punch through the 65 30 are secured to the other side of member 20 and to ground surface. ring 26, in alignment with spoke members 28 respectively. It will be thus understood that the object of my in Portions 28 and 30 are rigidly secured to the intervening vention is to provide a pad type roll of improved operat member 20 and the respective rings by welding or other ing characteristics which will provide more compaction equivalent means, and each portion 28 combines with its per pass to a speci?ed depth than would be provided by aligned portion 30 to form a complete spoke member a roll of the Gardner construction on a machine of the 70 28, 30. same weight, pad width and area covered per pass. Spokes 28, 30 carry four outer rings 32, 34, 36 and 38, In carrying out my invention in one form I provide compactor instead of a smooth ?nish. 3,085,483 and around the periphery of these rings are secured a plurality of spaced outwardly curved pads which I have indicated by the numerals 40, 42, 44 and 46 respectively, for the four rings. It will be observed that all pads 42 and 44 are identical, and that all pads 40 and 46 are identical, with a minor exception mentioned hereinafter, and that the pads on all rings are uniformly spaced around the respective rings. It will be noted also that pads 40 and 44 are in alignment transversely of the wheel while 4 44 on both the front and rear wheels are four inches wide and approximately 1]. inches long measured along the outer curved ground engaging surface. In this same ex ample, the pads 40 and 46 of the front wheels are 3 inches wide and approximately ll inches long, while the pads 41 and 47 of. the rear wheels are 5 inches by approximately ll inches. In these wheels the lateral spacing between rows of pads is 3 inches and 2 inches, being 3 inches for spaces A and B on wheel 12 and spaces E and F on wheel pads 42 and 46 are in alignment with each other but are 10 14. and 2 inches for space C on wheel 12 and space D on staggered with respect to pads 40 and 44. All of the fore w. eel 14; while the pads in all rows are uniformly spaced going components maliing up the wheel are rigidly sc curcd together to form a compaction wheel or roller hav ing a broken cylindrical compaction surface composed of raised outwardly curved individual pads. around the periphery and the spacing between adjacent individual pads in all rows is approximately 2%‘; inches. Thus, the ground contacting area of the pads is approxi mately 52% of the total cylindrical area of the wheel in The wheel illustrated in FIGURES 2, 3 and 4 is the cluding both pads and intervening spaces for the front right front wheel of the vehicle 10. The left front wheel wheel 12, while for the rear wheel 14 the percentage is is the mirror image of this wheel. It will be observed approximately 57%. It will be appreciated that these that in the front wheels the main structural member 20 percentages may be varied somewhat, depending upon the is offset laterally somewhat from the center of the wheel. 20 characteristics of the soil or other material being com FIGURES 5, 6 and 7 show the right rear wheel of vehi pacted, without departing from the present invention. cle 10, with FIGURE 5 being an enlarged side elevational The improved compaction provided by these Wheels view and FIGURE 6 an elevational view looking from results from the numerous sharp changes in unit pressure the front of the vehicle while FIGURE 7 is a partial sec on the ground as each wheel rolls over it. This will be tional view along the line 7~-7 of FIGURE 5. The basic understood by referring to the two dashed lines drawn structure of this wheel is generally similar to that of the transversely across the pads in FIGURE 3. Assume for front wheel previously described and I, therefore, have purposes of illustration that the wheel is in a position indicated by the same identifying numbers the correspond such that the line 56 is directly at the bottom of its travel ing parts on this wheel. It will be observed that on this and, therefore, that the portions of the pads along this rear wheel the main supporting member 20 is located 30 line, and also areas of the pad along both sides of the centrally of the whcel, so the rear wheel is somewhat dif line, of course, are in contact with the ground. The pad ferent in this respect. area in contact with the ground at this time is thus a func It will be observed that the pad arrangement of the rear tion of the width of all four pads. wheel differs from the front wheel in that wider pads are Assume now that the wheel has rolled until the line used to form the. two outer rows of pads, and this has 54 is directly at the bottom. At this time the pad area been indicated in FIGURES 6 and 7 by utilizing for the center rows of pads the same numerals 42 and 44 and in contact with the ground is approximately half that at the time when line 56 was at the bottom of the wheel for the wider outside pads the numerals 41 and 47. The travel. There has been a sharp change in the unit pres rear wheel illustrated in the last three ?gures of the sure applied by the wheel on the gorund, and this pro drawing also differs from the front wheel in that the 40 duces a very desirable tamping action. In this particular outer compacting surface of the pads of the rear wheel example the ‘change in unit pressure on the ground is ap is not a true cylinder but the rows of pads are tapered slightly, that is, the circumferential rows of pads have decreasing diameters away from the longitudinal axis of the vehicle, forming, in effect, a broken frustro conical surface. This can be seen in FIGURES 6 and 7 which are exaggerated from the actual construction in order to illustrate this feature. The line 49 in FIGURE 6 shows proximately in the ratio of 1:2, although it is not exactly this in the usual case because of the fact that the wheels tend to sink ‘into the ground more as the pressure in creases which increases the contact area and decreases the unit pressure. It will be understood that with this design the unit pressure provided by each wheel varies con~ tinuously as the wheel rotates, thus providing a continuous the outline of a true cylinder. The reason for this con tamping action as the rolling machine moves along the struction is that the rear wheels on machine 10 are the 50 ground. This increases the efficiency of the compacting steering wheels, and as a result are arranged to have a small amount of camber. Making the outer compaction surface of the wheels slightly tapered compensates for this camber and provides for the ground engaging portion action, resulting in more compaction per pass to a given depth for a given machine weight than with prior art pad type compacting rolls. The particular machine described and illustrated herein of the outer surface of the wheel to be approximately weighs approximately 34,500#. With the pad and Wheel horizontal. It will be appreciated that the opposite rear dimensions given hereinbefore this provides a ground line wheel is tapered in the other direction to compensate for pressure variations between a maximum of approximately the opposite camber in that wheel. 1080# per linear inch of wheel width and a minimum of It should be kept in mind in connection with compac 540# per lineal inch of pad width, assuming the load is tion wheels or rolls of this type that the pads must be 60 divided among the Wheels in proportion to their ground of such size and arrangement that there is sut?cient pad contacting areas. area in contact with the ground at all times to buoy up The front and rear wheels of the machine It} comple the machine or ?oat it on the surface of the ground, and ment each other in their compacting action inasmuch as not let the pads punch through the surface of the ground they are in alignment on the respective sides of the ma a considerable amount as with a sheep’s foot roller, for 65 chine and the pad patterns on the front and rear wheels example. On the other hand, there must be sut?cient are such that the pads on the rear wheel tend to cover the open space around the pads, and the pads must be raised areas not compacted by the front wheels and vice versa sufficiently away from the main structure of the wheel, providing thereby a move uniformly compacted area in that the dirt being compacted does not clog the spaces the path of the machine. around the pads and thus, in effect, produce a roller hav 70 ‘It will be observed that the corners are cut off two of ing a solid surface and having the consequent disadvan the pads in the left row in both FIGURES 3 and 6. This tages inherent with solid rolls. was not done to change the compacting action but rather In one typical machine, in which the outside diameter was necessary with the wheels illustrated herein to permit of all wheels is approximately 60 inches, the pads 42 and 75 the installation of cleaners which are not shown in this 3,085,483 drawing. The absence of corners on these two pads does not affect signi?cantly the compacting operation of these wheels. When reference is made in the subsequent claims to uniform pads or rectangular pads it should be under stood that it is intended to cover also pads such as these with insigni?cant changes in the uniform pattern or from rectangular shape. Also, that individual pads are slightly curved, even though referred to herein, for clarity and convenience, in terms which ordinarily are applied to pla nar ?gures. Similarly, it should be understood that where reference is made in the claims to an approximately cylindrical wheel, it is intended to cover minor variations from cylin drical such as the slightly tapered wheel-s 14. 6 greater than the width of the narrowest of the adjoining pads, the pads in the two center rows being of approxi mately equal width, the pads in the two outer rows being approximately equal in width and different than the width of the said center rows, the space area between and around the said pads and within the margins of the cylin der equalling at least approximately 43% of the total cylindrical surface area, and one each the center and out side rows being staggered approximately half a pad length with respect to the other two rows whereby as the roll 10 moves over the surface of the ground the pad area in contact with the ground varies sharply at frequent inter vals during a complete revolution to provide tamping ac~ tion on the ground. 3. A rolling machine having four compaction wheels, Other means such as eccentric axles and vibrating means 15 each wheel comprising a central supporting structure and attached to the wheel or roller have been used previously four annularly ‘arranged rows of approximately rectangu to secure a tamping type action by a wheel or roller, but lar outwardly curved thin ground engaging pads rigidly it has been found possible to secure superior tamping action with the construction disclosed and illustrated here in at far less cost than any prior art construction of which I am aware. Moreover, with this construction it is not necessary to design and construct a special machine for compacting operation only. The machine 10 illus trated is a multi-purpose machine which is useful as well joined to the supporting structure in raised relation to form an approximately cylindrical broken rolling surface, all of the said pads being of approximately equal extent circumferentially, the adjacent pads in all the said rows being uniformly spaced apart circumferentially and adja cent rows on each individual wheel also being spaced apart axially by an amount not exceeding the width of the for other operations. It serves readily as a bulldozer or a 25 narrowest of the adjoining pads, the two center rows of towing tractor merely by removing the present compac tion wheels and installing instead rubber tired wheels, an operation which can be performed in the ?eld in a short pads on all wheels being approximately equal in width, the two outer rows of pads on the wheels on one end of the machine being approximately equal to each other ‘ but less in width than the center rows, the outer rows of It will be readily understood that the present invention 30 pads on the wheels at the other end of the machine being is not limited to the speci?c con?guration, size and spac approximately equal to each other but wider than the ing of pads described and illustrated herein, but that one said center rows, the wheels on each side of the machine or more of these can be varied to suit speci?c conditions. being in alignment so that each pair of front and rear It will be understood also that whel I have disclosed a wheels cooperates in compacting the soil, and one row of 35 skeletal wheel construction and peripheral rings for mount‘ pads of a certain width in each wheel being staggered ing the individual pads to raise them above the main por approximately half a pad length with respect to the other time. tion of the wheel structure, that it is possible to use other means for raising the pads, such as individual spokes, for example, beneath each pad connecting it to the remainder duplicate row in that wheel whereby as the wheels roll over the surface of the ground the pad area on each wheel in contact with the ground varies sharply at fre of the wheel structure. It is essential, however, that the 40 quent intervals to provide a tamping action on the ground. pads ‘be raised to provide ready egress for dirt which 4. A compaction roll for mounting on a vehicle, com passes through the spaces between pads during rolling. prising a central supporting structure, four annularly ar It is preferable that the wheel structure be of the skeletal ranged rows of approximately rectangular outwardly type to further facilitate the disposal of such dirt; however, curved thin ground engaging pads rigidly joined to the said in some cases it may be desirable for the main body of supporting structure in raised relation to form an approx the wheel to be hollow in structure making it possible to imately cylindrical broken rolling surface, the dimensions add water and thus increase the weight of the wheel and and spacing of said pads being proportional to the dimen of the entire rolling machine. sions and spacing set out hereinafter for a typical roll Thus, while I have illustrated and described herein a approximately 60 inches in diameter: the pads of the two preferred embodiment of my invention, it will be under center rows approximately 11 inches circumferentially by stood that modi?cations may be made. I intend to cover approximately 4 inches axially and the two outer rows by the appended claims all such modi?cations falling approximately 11 inches circumferentially by approxi within the true spirit and scope of my invention. mately 3 inches axially, the adjacent pads in all of the I claim: said rows being spaced apart approximately 27/16 inches, 55 1. A compaction wheel comprising four rows of raised the said two center rows being spaced apart approximately annularity arranged outwardly curved thin ground engag 3 inches axially and one of the center rows being spaced ing pads, all pads being of greater extent circumferentially approximately 3 inches axially from one of the outer rows than axially, the pads in one pair of the rows being of and the other center row being spaced approximately 2 similar axial extent but of substantially different axial inches axially from the other outer row, the pads on one extent than the other pair of rows, and the individual 60 each of the center and outside rows disposed in axially rows of each pair being mutually staggered with respect to each other, whereby as the wheel rolls over the surface of the ground the pad area in contact with the ground varies sharply at frequent intervals during a complete alignment and the pads on the other two rows being staggered approximately half a pad length with respect to the ?rst two said rows whereby as the roll moves over the surface of the ground the pad area in contact with the revolution to provide a tamping action on the ground. 65 ground varies sharply at frequent intervals during a com 2. A compaction roll for mounting on a vehicle, com plete revolution to provide a tamping action on the prising a central supporting structure, at least four an ground. nularly arranged rows of approximately rectangular out 5. A compaction roll for mounting on a vehicle, com wardly curved thin ground engaging pads rigidly joined prising a central supporting structure, four annularly ar 70 to the said supporting structure in raised relation to form ranged rows of approximately rectangular outwardly an approximately cylindrical broken rolling surface, all of the said pads being of approximately equal extent cir cumferentially, the adjacent pads in all the said rows being curved thin ground engaging pads rigidly joined to the said supporting structure in raised relation to form an approximately cylindrical broken rolling surface, the di uniformly spaced apart circumferentially and adjacent mensions and spacing of said pads being proportional to rows also being spaced apart axially by an amount not 75 7 3,085,483 the dimensions and spacing set out hereinafter for a typi~ cal roll approximately 60 inches in diameter: the pads of the two center rows approximately 11 inches circum ferentially by approximately 4 inches axially and the two outer rows approximately 11 inches circumferentially by approximately 5 inches axially, the adjacent pads in all of the said rows being spaced apart approximately 2%.; S proximately 2 inches axially from the other outer row; and for the two wheels at the other end of the machine the pads of the two center rows approximately 11 inches circumferentially by ‘approximately 4 inches axially and the two outer rows approximately 11 inches circumferen tially by approximately 5 inches axially, the adjacent pads in all of the said rows of the last-mentioned two wheels inches, the said two center rows being spaced approxi being spaced apart circumferentially approximately 27/16 mately 3 inches axially and one of the center rows being spaced approximately 3 inches axially from one end of the 10 inches, the said two center rows of each of the said last mentioned wheels being spaced apart approximately 3 outer rows and the other center row being spaced approx inches axially and one of the center rows being spaced imately 2 inches axially from the other outer row, the approximately 3 inches axially from one of the outer rows pads on one each of the center and outside rows disposed and the other center row being spaced approximately 2 in axial alignment and the pads on the other two rows being staggered approximately half a pad length with re 15 inches axially from the other outer row, the front and rear Wheels on each side of the machine being in align spect to the ?rst two said rows whereby as the roll moves ment whereby the front and rear wheels of each pair co over the surface of the ground the pad area in contact operate With each other in compacting the soil, and one with the ground varies sharply at frequent intervals dur each of the center and outside rows of pads of each wheel ing a complete revolution to provide a tamping action on being staggered approximately half a pad length with re the ground. 20 spect to the other two rows of that wheel whereby as the 6. A rolling machine having four compaction wheels, wheels roll over the surface of the ground the pad area each wheel comprising a central supporting structure and on each Wheel in contact with the ground varies sharply four annularly arranged rows of approximately rectangu at frequent intervals to provide a tamping action on the lar outwardly curved thin ground engaging pads rigidly ground. joined ‘to the supporting structure in raised relation to form an approximately cylindrical broken rolling surface, References Cited in the ?le of this patent the dimensions and spacing of said pads being propor tional to the dimensions and spacing set out hereinafter for typical wheels approximately 60 inches in diameter: for the two Wheels at one end of the machine the pads 30 of the two center rows approximately 11 inches circum ferentially by approximately 4 inches axially and the two outer rows approximately 11 inches circumferentially by approximately 3 inches axially, the adjacent pads in all of the rows of the said two wheels being spaced apart circumferentially approximately 27/16 inches, the said two center rows of each such Wheel being spaced apart ap proximately 3 inches axially and one of the center rows being spaced approximately 3 inches axially from one of UNITED STATES PATENTS 243,463 1,432,984 2,674,165 2,754,734 Schaefer _____________ __ June 28, Eburne ______________ __ Oct. 24, Paramythioti __________ __ Apr. 6, Gardner _____________ __ July 17, 1881 1922 1954 1956 2,895,390 Gardner _____________ __ July 21, 1959 734,479 591,437 Germany ____________ __ Apr. 16, 1943 Great Britain _________ __ Aug. 18, 1947 FOREIGN PATENTS OTHER REFERENCES Roads and Engineering Construction, page 90, October the outer rows and the other center row being spaced ap 40 1954.