US3255682A - Compacting apparatus - Google Patents

Description

June 1966 s. GlERTZ-HEDSTROM 3,255,682

COMPACT ING APPARATUS Original Filed May 12, 1959 Fig.1

INVENTOR. STIG GIERTZ-HEDSTROM ATTORNEYS United States Patent 3,255,682 COMPACTING APPARATUS Stig Giertz-Hedstrom, Knivsta, Sweden, assignor to Aktiehoiaget Vihro-Verken, Stockholm, Sweden, a corporation of Sweden Continuation of application Ser. No. 812,748, May 12, 1959. This application June 9, 1964, Ser. No. 373,702 Claims priority, application Sweden, Nov. 12,1958,

0,478/58 1 Claim. (Cl. 9450) The invention disclosed and claimed herein is a continuation of application Serial No. 812,748, filed on May 12, 1959 in the United States Patent Office and now abandoned.

This invention, generally, relates to compacting apparatus and, more particularly, to apparatus of the type adapted for use in compacting earth, gravel, and other materials in construction projects.

In the past, vibratory as well as nonvibratory rollers have been used, for example, in road building and the like. The vibratory type of roller has been found to exhibit excellent compacting abilities which are desirable for compacting earths of the non-clay type, whereas vibratory rollers offer very little compacting effect in earths having high clay content, due to the high elasticity of clayish earths.

To compact clayish earths, that is, earths having a high clay content, the practice has been to increase the surface pressure exerted on the clayish earth, primarily by increasing the weight of the roller. An example of such a roller is the so-called rubber wheel roller which, even though it is extremely heavy, is still incapable of effecting a particularly high degree of compactness and, in addition, is unwieldly and awkward to maneuver.

It also has been the practice in the past to increase surface pressure by providing the surface of a roller with radially-projecting spikes or. studs (so-called sheeps feet) which cause a kneading and caking of even clayish earths. This type of'apparatus is superior, in certain instances, to the compacting effect obtainable by a rubber wheel roller.

However, there are disadvantages even in the heretofore known type of sheeps foot compacting apparatus. For example, the sheeps foot apparatus used in the past compacts only a relatively shallow layer of earth and the compacting achieved during each pass over a particular area is dependent directly upon the radial length and the face area of each sheeps foot. It has been found that the length of each sheeps foot cannot be increased materially because, apart from the weakening structural effect it produces in each sheeps foot, an excessive radial length tends to break up the earth already compacted as each thus-formed sheeps foot commencesits upward movement from the lowermost, downwardly-extending, compacting position.

Accordingly, an object of the present invention is to provide a compacting apparatus superior to any compacting apparatus known heretofore.

It is also an object of the invention to provide a compacting apparatus which combines a vibratory motion with a sheeps foot apparatus to present a unique, novel, and particularly advantageous compacting apparatus.

A further object of the invention is to provide a compacting apparatus which overcomes the disadvantages characteristic of compacting apparatus heretofore known.-

According to the invention, generally, a plurality of radiallyextending projections, or studs (so-called sheeps feet) are formed over the surface of a roller. In addition to the arrangement of the sheeps feet, a means is provided for effecting a vibratory motion to the roller and to the sheeps feet, or projections.

The invention provides, among its advantages, a considerably more deep-reaching and laterally reaching compacting effect as compared with heretofore-known compacting apparatus. Moreover, this advantage is achieved, according to the invention, Without the necessity of increasing the radial length of the sheeps feet or the weight of the roller.

Actually, according to the new and novel structural arrangement of the invention, the vibrations generated by the vibratory unit transmit compacting motion not only through the surface of the roller cylinder itself but, also, through the projections, or sheeps feet, that penetrate the ground layer supporting the roller.

In addition to the above, it has been found that highly clayish earths do not adhere'to the roller of the invention and, as a result thereof, the projections actually penetrate further into the earth than with compacting apparatus heretofore known.

Other objects and advantages of the invention will became apparent to one skilled in the art to which the invention pertains from the following detailed description of the presently preferred embodiment thereof, which is described with respect to the accompanying drawings in which similar reference characters represent corresponding parts in the several views and wherein:

FIG. 1 is a view in side elevation of a compacting apparatus in accordance with a preferred embodiment of the invention; and

FIG. 2 is a plan view of the embodiment of the invention shown in FIG. 1 wherein certain sections are broken away to show underlying structural arrangements.

Referring now particularly to the preferred embodiment of the invention for illustrative purposes only, however, the campacting apparatus includes a frame 1 and a cylindrical roller 2 suitably journaled to support the frame 1. A plurality of projections, spikes, studs, or the like, 3 (so-called sheeps feet) are mounted on the surface of the roller 2 to extend substantially radially therefrom.

A principal purpose of the projections 3 is to penetrate the material to be compacted as the roller 2 is moved along a desired path. Of course, the projections 3 may take any of a number of possible configurations, a preferable configuration for the projections 3 being that of a truncated pyramid, as shown for illustrative purposes in the drawings.

Extending axially througth the roller cylinder 2 is a drive shaft, or axle 4, arranged to drive two axiallyspaced vibrators. Each of these vibrators, known per se heretofore, has an annular rolling track 5 serving as a circular race for a' ball 6. Of course, the ball 6 is entirely unrestricted concerning its freedom of movement along the track 5, and the ball 6 is moved along the track 5 by means of a dog member 7 which is keyed rigidly to the shaft 4.

To generate the vibratory motion in the surface of the roller cylinder 2 and also in the projections 3, the shaft 4 is rotated by means of an elastic transmission in the form of a belt drive comprising one or more V-belts 9. These belts 9 transmit power from a prime mover 8, or drive means, mounted on the rear portion of the frame 1.

The actual vibratory effect is amplified by a weight 10 fixed eccentrically between the vibratory units shown in the drawings. The vibratory movements imparted to the roller 2 and the projections 3 by the rotating elements, independently of roller rotation, are directed radially of the shaft 10. Such vibrations of the flat surfaced projections 3 effectively compact material into which the projections extend.

To protect the frame 1 from the vibratory motions generated and developed by the apparatus, the frame 1 is suspended from the roller cylinder 2 by resilient members 13 so that the vibratory motions are not transmitted to the frame 1. This is advantageous not only in protecting the drive means 8 from such vibrations, but also in preventing the frame 1 and the drive means 8 from exerting a vibration-damping effect on the apparatus.

The invention may be embodied in other specific forms without departing from the essential characteristics thereof. Hence, the present embodiments are to be considered in all respect as merely illustrative and not as being restrictive the scope of the invention being indicated by the appended claim rather than by the foregoing description, and all modifications and variations as fall within the meaning and purview and range of equivalency of the appended claim are therefore intended to be embodied therein.

I claim:

A compacting machine comprising a frame structure including a pair of bearings, a hollow roller having roller bearings and carrying a plurality of radially extending, outward converging, tapered earth engaging projections, each having a face at its extremity which is substantially parallel to the surface of the roller, the projections being arranged in a multiplicity of closely adjacent circumferential rows whose combined base areas occupy at least one half of the surface area of the roller, the tapered projections in alternate rows being staggered in a generally checker arrangement whereby the edges of the bases of the projections in one row extend circumferentially at least to the edges of the bases of the projections in adjacent rows and each having a flat outermost surface which is generally one quarter of the area occupied by the base of each projection, a driven rotatable shaft extending through the roller and supported by the roller bearings therein, said shaft also being journaled in the frame bearings, a vibration generator disposed in the roller including weight means unbalanced with respect to the shaft and rotated by the shaft concentrically therewith to impart vibratory movements to the radial projections independently of the rotation of the roller, said vibratory movements being directed in all radial directions from said shaft to compact material into which the radial projections extend, drive means mounted on the frame, and means coupling the drive means to the shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,384,469 9/1945 Kalix 94--50 2,677,995 5/1954 Wood 94-50 2,868,094 1/1959 Anderson 9450 FOREIGN PATENTS 571,105 8/1945 Great Britain.

CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, Examiner.

Images