US2677995A - Vibratory earthworking roller - Google Patents

Description

May 11, A1954 c. w. WOOD 2,677,995

VIBRATORY EARTHWORKING ROLLER Filed Nov. 5, 1948 2 Sheets-Sheet l Mk/wr May l1, 1954 C. w. WOOD 2,677,995

VIBRATORY EARTHWORKING ROLLER Filed Nov. 5, 1948 2 Sheets-Sheet 2 Patented May 11, 1954 This invention relates to road making equipment and more particularly to roller construei tions employed in conipacting road surfacing ma* terials.

It is a common practice in road making to draw some form of heavily weighted roller struc ture over loose materials which have been freshly placed upon a roadway so that such materials may ce forced into a desired compact relationship. This practice is followed in the preparation of dirt nlls, crushed rock foundations, various foundation aggregates7 oiled earth compositions used for top layers, asphaltic mixtures employed as uppermost surfacing layers, and the like. However, when rolling down applications of most of these layer-forming materials, it would be preferable if all them could be compacted to a much greater degree than has been the current operating practice.

As one aspect of this invention, l' have discovered that roller structures employed for compacting road surfacing materials in operative position upon roadways may be made more eiiicient by incorporating therein means which irnpart a powerful vibratory action to the roller, inasmuch as such a vibratory roller structure, when drawn across the applied layer of road forming material renders much more dense the resultant compacted layers, and as a consequence produces a more durable and a more serviceable highway.

it is, therefore, an object of this invention to provide a road working roller construction provided with means for vibrating the structure as it is drawn over surfacing material applied to a roadway so that the surfacing material is compacted to a much greater degree than is possible by action of the mere weight oi' the roller structure.

It is also an object of the invention to ern ploy high speed rotary mechanical means, such as accentrically mounted weighting masses, to effect the desired vibration.

Another object of the invention is to provide means which will control the vibration so that it may be applied in desired directions with respect to the surface of the roadway, and it is an incidental object to control the resultant vibration and apply it as required for best effect.

Still another object of the invention is to use the axle means upon which an earth working roller is mounted as a means through which the vibratory influences are imparted.

An additional object is to employ means eccentrically mounted adjacent the axis oi the earth working roller and adapted to be power driven by way of the rollers axle for the application of the vibratory movements and impulses. l

Other objects of the invention and the various features thereof, will become apparent to those skilled in the art upon reference to the following speciiication and the accompanying drawings wherein certain embodiments of the invention are disclosed by way oi illustration.

In the drawings:

Fig. 1 is a side elevation oi an earth working roller embodying the improvements ci this invention;

Fig. 2 is a top plan View of the structure shown in Fig. 1;

Fig. 3 is a transverse vertical section taken from the line 3-3 of Fig. l;

Fig. i is a vertical sectional as indicated by the line t-li of Fig. 3;

Fig. 5 is a vertical section similar to that of Fig. @i but illustrating a modincation of the vibration-producing means for the earth working roller; and

Fig. 6 is a fragmentary longitudinal section as indicated by the line li-5 of Fig. 5.

The drawings illustrate a road engaging roller i@ mounted upon'and supporting a chassis or frame I2 which in turn supports a power plant it from which are driven means within the roller it for producing the required vihratory effect.

i-Iaving particular refer-ence to Fig. 3, one power plant lli is illustrated as comprising an internal combustion engine i5 of conventional construction which is used in conjunction with a conventional radiator it and serves to actuate any appropriate transmission means contained within a conventional transmission housing i6 equipped with a conventional clutch shifting lever 2li or other appropriate power controlling device.

The implement frame i2 may comprise side rails 2i of I-beam construction as illustrated and such cross rails as required. These include forward cross rails E2 upon which the power plant it is mounted and its rearward cross rail 22d. In the form illustrated, the forward portion of the frame E2 carrying the power plant ld is offset downward. with respect to the rearward portion of the frame i2, the parts being appropriately connected and braced as through the medium of angularly disposed, intermediate frame sections 2 la shown in Fig. l. rThis arrangement serves to lower the power plant lli somewhat with respect to the road engaging roller it. The forward portion ci the frame l2 is conveniently provided with converging tongue members 23 which carry at their forward, contacting ends any appropriate hitch 2s for connection 0i the roller structure to a tractive implement by means of which the roller is drawn along the surface being prepared, the most forward cross rail 22 bracing the rearward portion oi the tongue structure.

The frame l2 is supported from the roller l0 through the medium of elongated, heavy rubber mounts 2t, best seen in Figs. l and 3. The upper edges of these rubber mounts 25 are mounted in upper brackets 2'3 carried by the adjacent portions of the side rails 2|, andthe lower edges of the rubber mounts 25 are carried in lower brackets 2l provided at the edges of bracket plates (Fig. 3) mounted upon the-tops` of appropriate bearings 28 in which are joui-nailed the opposite ends of an axle 30 for the roller lil.

The roller ifi comprises an outer, road engaging shell in the form of a cylindrical drum t2 which contains within it an inner cylindrical shell 33 constituting aninner frame member, the drum 32 and the shell 33 being rigidly carried by drum heads Eli. The heads 34 carry bearing rings 35 constructed to provide journals for bearings SS on the axle 30. The bearing rings are appropriately secured to the drum heads Sfl, as by means of: the screws 31 shown in Fig, 3. If required, flanged portions of the rings may carry suitable packing 38.

In the form oi' construction illustrated, particularly in Figs. 3 and 4, the axle liti is provided within the frame-forming shell 33 with an eccentrically disposed weightdil illustrated as being an elongated cylindrical mass whichv revolves within the shell 33 when the axle 3Q is rotated in its bearings 28.

Rotation of the axle 3Dfis effected from a drive shaft t?. which extends from thetransmission housing i3 of the power plant, i4* and carr'es appropriate sprockets 43 which receive drive chains dll'or \fbelts that pass to and around sprockets or V-pulleys de nxed on one end of the axle 30. Thus, by proper actuation of the clutch lever 2li on the transmission housing |13 the chains 115.- are energized and the axle 3U rotated in its bearing 28 and also in the bearings 350i the roller lo. Under these circumstances the eccentric weight 49 fixed on the axle 3i) is caused to revolve at high speed. Such a speed maybe in the order of 1000 to 50Go revolutions per minute, and as a consequence the eccentricity of the weight 49 produces a high degree of vibration, as hereinafter more fully explained.

ln order properly to tension the drive chains M or belts, idle sprockets 46 or belt idle-rs (Fig. l) may be employed, these beingcarried as by means of a plunger el cushioned against appropriate spring means in a housing 4,8 mounted upon the adjacent portion of the frame I2. If required to apply additional weight eifectivc upon the road engaging roller IG, a weight box 159y may be mounted upon the rear ofthe implement frame I2 for the purpose of receiving appropriate ballast.

A modiiication oi?V the vibration-producing structure shown in Figsg 3 and 4- is illustrated in Figs. 5 and G. This construction makes it possible to control the direction or plane of applied vibration to a very large extent by providing for rotational balance in a plane at right angles to the desired plane of applied vibration. Here, two sets of cooperating eccentrically disposed weighting masses are employed. In this instance, the

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axle 30 carries a plurality of spaced, narrow eccentric weights fiile instead of the single elongated weight iii of the other form, and these eccentric weights dta are staggered with respect to a plurality of spaced, narrow eccentric weights 50 which may be ci the crescent formation shown in Fig. 5. The eccentric weights 58 are secured to the inner wall of a rotating frame member or carrier illustrated as being in the form of a cylindrical shell 52 occupying,r the position of the inner shell 33 of the other form. The shell 52 is provided with a head 53 at each end, and each head is mounted upon the by means oi ball or equivalent bearings li?! somewhat as illustrated in Fig. 6. Each head ES provided also with an integral bearing ring 55 which carries ball or equivalent bearings 55 by of which the respective head Si of the drum 22 is thus indirectly-journalled on the shalt 3Q. Flanges 58 serve both to retain the bearings Eil appropriate packing means.

The shaft 30 is adapted to be rotated in the main bearings 28 by means et a bevel gear 60 fixed thereon, and the inner carrier member 52 is adapted to be rotated upon the axle 3Q as by means of a bevel 52 journalled upon the shaft 30 through ball bearings or the like and fixed to the adjacent bearing ring of the Shell 52. lnthe form shown two bevel gears E@ and .32 are driven through an intermediate bevel gear 64 from a drive shaft 55 which would be in turn driven from the power plant ll. As an alternative, the shaft 30 could be driven shown in Fig. 3, in which case the beveled gear 62 would be driven from the beveled gear 6B through the medium of the gear Gti serving as an idler, the shaft t5 then serving as a mounting means for the gear 64.

It will be apparent, that when one of the gears and 62 is driven in one direction, other is driven in the opposite direction, such counterrotational relationship being indicated by arrows in Fig. 5. Thus, when the eccentric weights G00, are in` opposition to the eccentric weights 5B, as illustrated in Fig. 5, the entire vibration-producingA unit is balanced, provided the masses of the weights lilla and the masses of the weightsl 50 are equal as would commonly be the case. However, when the shaft 30 and the carrier member or shell 52 has been rotated 90 from the position of Fig. 5, the eccentric weights 40a are then in apposition, by reason of the fact that they have their centers of mass aligned. At this stage the parts of the vibration-producing unit are ina maximum condition of unbalance and as a consequence the eccentric forces acting to produce vibrational impulses are eifective in a plane in which are disposed both the axis of the shaft 3G and the radius in which lie the centers of mass ofthe eccentric bodies constituting the weights dta and 5i?. Thus, in each 3660 cycle the weights ta and 5B are twice in balance and twice in unbalance.

Operation When the road rolling structure of this invention is to be placed in operation, the hitch 24 is connected to any oppropriate tractivc implement by which* the device may be drawn slowly along the roadway, or tractive means maybe applied to the road rolling structure itself, if desired. Prior to moving the roller li) upon the road surface, the power plant IE is placed in operation, and when the roller I@ is to be moved upon the material to be compacted, the clutch lever is shifted to actuate the drive chains 4d and turn the axle 30 in its bearings 2B. As the axle turns within its bearings 23, it also turns within the bearing rings of the drum head 311 where the form of structure shown in Fig. 3 is employed. Thus, while the roller I0 is being drawn or propelled forward at a very slow rate, for example lAr-S miles per hour, the eccentric weight d0 is being revolved within the inner shell 33 at a vibratory rate of speed which may be in the range of 1000 revolutions per minute to 5000 revolutions per minute or other appropriate rate. In actual practice, it has been found that such a high rotating speed of the axle 30 produces in the roller I0 a vibration of a magnitude to compact the underlying road surfacing material to a very much greater degree than is possible when pulling across it a roller structure of the same weight. In fact, the additional compacting action is far greater than can be obtained by increasing the weight of the roller structure to any practicable extent. As a consequence of rolling down a layer of road surfacing material with a roller equipped with the described vibrating mechanism, a very much firmer and denser layer of surfacing material is produced than possible heretofore, and such surfaces are much more durable and therefore offer much longer service under the pounding of heavy traffic and overloads. In specific instances I have found that the `compacting of loose, road surfacing materials spread on a roadway being built or repaired, commonly represents a compacting increase of as much as 20 percent.

When using the construction illustrated in Figs. 5 and 6, the impacting impulses are directed very largely in a vertical plane inasmuch as the vibrational. influences are directed upward and downward while substantially rotational balance is provided transversely, although important impact is accomplished regardless of the direction of the rotational unbalance. Thus, it is preferable to set up the vibrating apparatus so that the centers of the masses of the eccentric weights a on the shaft 30 are in horizontal balance with respect to the centers of the masses of the eccentric weights on the inner wall of the rotating shell '52. As a consequence, rotation of the two sets of eccentric bodies provided by the series of weights 40a and the series of weights 50 through an arc of 90 from either of their positions of transverse balance, results in maximum off-balance, that is, when their centers lie vertically above or vertically below the axis of the axle 30. Thus, in that part of the rotational cycle when all the centers of the masses of the two sets of weights flc and 50 are disposed vertically downward, the resultant vibrational impulse is downward, and when such centers are disposed upward along a vertical radius, the vibrational impulse is upward, whereas when such centers reach the horizontal they are horizontally opposed and the vibrational impulses become balanced or neutralized. Therefore, the vibrational inuences are largely controlled to be operative substantially linearly in a vertical plane in which the axis of the axle 30 is disposed. Stated in other words, in each cycle of 360 rotation, there are two horizontal stages of balance where the centers of masses of the weights lilla are in opposition to the centers of masses of the weights 50 and the whole vibrational unit is balanced so as to yield a substantially neutral condition. Also in each said cycle, there are two alternating stages of maximum unbalance, that is, when the centers of the masses 40a are in apposition with the centers of the masses of the weights 50. When these centers are up the vibrational impulse is upward, and when they are down the vibrational impulse is downward. Thus, the movement of the eccentric weighting masses are synchronized to yield the desired vibrational conditions.

The speed of the engine I5 of the power plant i4 may be regulated to produce a rate of revolution of the axle 30 and the eccentrically weighted shell 52 in the form of Figs. 5 and 6 to correspond best with the natural period of vibration of the apparatus as a whole. If necessary, the weight in the weight box 49 may be varied to effect the required vibratory conditions. The elongated, heavy rubber mounts Z5 between the implement frame I2 and the mountings of the rolls i0 adequately absorb any objectional transmission vibration between the roller ld and the frame i2 that might otherwise take place.

' In a similar manne-r, the speed of the engine I5 may be adjusted to cause the rotational speed of the shaft 30 and its eccentric weight l0 in the form of Fig. 3 to conform properly with the vibration period of the apparatus as a whole and thereby establish optimum operating conditions.

Inasmuch as variations of the generic invention herein disclosed will become apparent to those skilled in this art, it is intended to protect all such modincations as fall within the scope of the patent claims.

l claim my invention:

l. ln combination in a road working device: a roller adapted to engage a road surface and be moved therealong; axle means journalled within said roller; eccentrically disposed weighting means carried by said axle means and adapted to be rotated at speeds to vibrate said roller on said surface; a member rotatable within said roller adjacent and upon said axle means; eccentrically disposed weighting means on said member and rotatable therewith; and means for rotating said member'and said axle means in opposite directions.

2. A combination as in claim 1 including cooperating bearing means on said roller and axle means journalling said axle in said roller.

3. A combination as in claim 1 wherein said rotating means comprises gear means for rotating said member and axle means at the same speed.

4. In a combination in a road-working implement: a road surface engaging roller; axle means upon which said roller is rotatably mounted; framework in which said axle means is journalled; carrier means rotatably mounted within said roller about said axle means; eccentrically disposed weighting means carried by said carrier means; power means; and means connecting said power means to said carrier means to rotate said carrier means and its weighting means to vibrate said roller.

5. In combination in a road-working implement: a road surface engaging roller; axle means rotatably mounted in said roller; framework in which said axle means is journalled; eccentrically disposed weighting means fixed on said axle means to cause vibration of said roller upon rotation of said axle means; power means mounted upon said framework; means connecting said power means and axle means to rotate said axle means and its weighting means at vibratory speeds; eccentrically weighted carrier means rotatably mounted upon said axle means 7. and within said roller; and means connecting said power means to said carrier means for rotating said carrier means oppositely to the direc tion of rotation of said axle means.

6. In combination in a road working implement: a roller adapted to 'travel upon a roadway; axle means on which said roller is rotatably mounted; framework on which said axle means is mounted; viloration-producinfT means mounted on said axle means for iinpa ne' vibration effects to roller when being moved over aid roadway; power means connected to said axle means to actuate said axle means and said vibration-producing means; second vibration-produc ing means inovably mounted in said roller ad jacent axie means and movable with respect to the first mentioned vibration-producing means; and means connecting said second vibration-producing means with said power means for actuatingr second '-.fibrationproducing means.

7. A combination as in claim 6 wherein the actuating connections between said vibrationn producing means and power means are connested with said power means to rotate the two vibratioinproduoing means in opposite directions and move such vibration-producing means successiveiy between positions of opposition and apposition for successively prodri-ciner conditions of balance and imbalance to eir'ect vibration.

8. A combination as in claim wherein: said second vibraton-producing means includes a rotary member and both of said vibration-preducing means include eccentrically mounted weig ting means respectively carried by said axle means and said rotary member; and drive means is provided connecting' said power means with said axle means and said rotary member for rotating said eccent 1ieally mounted means in opposite directions for successively producing conditions of balance and imbalance to effect vibration.

9. In combination in road-working equipment:

a roller adapted to travel upon a roadway; axle means rotatably mounted in said roller; a carrier journalled within said roller upon said axle means; framework means in which said axle means is mounted; power means on said framework means; driving means between said power means and said axle means to drive the latter; vibration-producing means connected with said axle means and driven therefrom; second vibration-producing means carried by said carrier and cooperating with the nrst mentioned Vibration-producing means; and additional driving means between said carrier and said power means for operating both vibration-producing means from said power means.

i0. A combination as in claim 9 including gear means connecting the two vibratiomproducing means for relative movement by said drive means and drive connections into positions of balance maximum unbalance with. respect to each other for producing vibration of said roller.

1l. A combination as in claim 9 wherein the two driving means include means connecting said axle means and carrier to actuate said axle means and carrier in opposite directions` to effect movement of said vibration-producing means between positions of balance and maximum unbalance with respect to each other to vibrate said roller.

References Cited in the ile Of this patent UNITED STATES PATENTS lumber Name Date 1,943,137@ Jackson Jan. 9, 1934 2,325,763 Baily et al. Dec. 3l, 1935 2,655,974: ("reiner Sept. i219, 1936 2,096,911 Moore, Jr Oct. 26, 1937 2,248,478 Mall July 8, 1941 FOREIGN PATENTS Number Country Date 588,506 Great Britain May 27, 1947

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