US 2312471 A
Description (OCR text may contain errors)
March 2, 1943. J, Low v 2,312,471
I sg EP. FOOT TAMPER Filed Aug. 3, 1940 Patented Mar. 2, 1943 UNITED STATES PATENT. OFFICE SHEEP FOOT TAMPER John J. Low, Los Angeles, Calif.
Application August 3, 1940, Serial No. 350,453
My invention relates to tampers of the sheep foot type as used on tamping rollers for compacting the ground in the building of roads and the like. Such tampers comprise a foot and a shank and are usually formed of cast metal in a single piece with the'shank secured to the periphery of a cylindrical roller by a weld joint. The tampers are applied to the roller in circumferential and longitudinal rows so as to stud the roller with a multiplicity of the tampers and with such an arrangement that the feet of the tampers leave an unbroken tread-mark in the surface of the ground being tamped.
Continued use of the tampers on the roller cause the feet thereof to become excessively worn or otherwise damaged, and thus require replacement. Where each tamper is cast in a single piece the time, the difficulty and expense involved in replacing the tamper will be appreciated.
It is a purpose of my invention to provide a sheep foot tamper which is so constructed that the foot thereof is removably mounted on the remainder of the tamper or that portion which is permanently secured to the roller, whereby the foot may, when necessary, be readily removed and replaced without the necessity of disturbing the welded joint or performing Welding operations or the use of any special tools or fastening means.
Where the feet of the tampers are demountable as set forth, it is necessary, particularly where each foot is elongated as in my invention, that they be mounted on the roller so that all of the feet of any one circumferential row extend lengthwise circumferentially of the roller and that they be uniformly spaced from those ofan adjacent row in order to accommodate between the rows an implement for removing accumulated earth from the feet under rotative movement of the roller.
It is also a purpose of my invention to provide in a sheep foot .tamper having a demountable foot, means by which the foot may be mounted on the roller only in such a position that it is alined longitudinally with the feet of adjacent tampers of a circumferential row, thereby accomplishing the advantages above set forth.
A further purpose of my invention is the provision of a sheep foot tamper embodying a base for welding to the roller, a foot, a connection between the foot and base by which the two have detachable telescopic wedge engagement with each other, and means embodied in the connection by which the foot is alined on the base.
I will describe only two forms of sheep foot tampers each embodying my invention and will then 'point out the novel features thereof in claims.
In the accompanying drawing:
Fig. 1 is a view showing in side elevation one form of sheep foot tamper embodying my invention.
Fig. 2 is a longitudinal sectional view taken on the line 2-2 of Fig. 1. V
Fig. 3 is a transverse sectional view taken on the line 3-3 of Fig. 1.
Fig. 4 is a fragmentary view showing in end elevation a tamping roller having applied thereto sheep foot tampers of the form shown in Fig. 1.
Fig. 5 is a view showing in side elevation'another form of sheep foot tamper embodying my invention. I
Referring specifically to the drawing in which similar reference characters refer to similar parts in each of the several views, and particularly to the form of my invention illustrated in Figs. 1 to 4, inclusive, the tamper embodies a shank element and a demountable foot element generally indicated at S and F, respectively. The shank element S is formed of cast steel so that by a weld joint it may be readily and rigidly fixed on the periphery of a cylindrical metallic roller R as illustrated in Fig. 4. The foot element F is likewise formed of cast steel but sufiiciently hardened to render it resistant to abrasive wear.
The shank element S is shown as comprising an elongated body II] on one end of which is an integral shank I I having a taper of relatively low pitch. The large end of the shank II is of less diameter than the confronting end of the body ill to form at the junction of the two an annular shoulder l2. At that end of the body I0 remote from the shank is a base [3 integral therewith and having a bearing surface 14 which is concave to conform to the curvature of the periphery of the roller R to which it is adapted to be welded. As illustrated, the base l3 extends at its ends the same distance from the body l0 and hence may be secured to the roller R without regard to which end is foremost in respect to the circumference of the roller.
The shank |I,in addition to being tapered as described, is formed at diametrically opposed points with grooves or indentations l5, l5. These grooves extend from the free end of the shank inwardly and may terminate in inclinedgshoulders H5 at points spaced fromthe shoulder l2. It is important to note that the grooves increase in depth from the free end of the shank inwardly in such manner that they are straight from end to end and therefore parallel to the major axis of the shank.
The foot element F embodies a collar I! the inner periphery of which is tapered to conform to the taper of the shank l I so that when the latter is extended into the collar it will have wedged frictional engagement therewith. The foot element also embodies a foot l8 formed integral with the collar I! and having a tread portion [9 of arcuate form. The curvature of the tread portion I9 is such that with the foot element mounted on the shank element and the latter secured to the roller R, such tread portion will extend in the direction of the circumferential length of the roller and concentric of the roller axis.
The tread portion l 9 may terminate at its rear end in a heel 20 and at its forward end in a toe 2|. As shown, the heel 20 and the toe 21 are rounded in continuation of the tread portion 19 so as to impart to the end faces of the foot a continuous curvature. Thus, on rotating the roller R the tread will be brought into and out of contact with. the surface being tamped with only a minimum disturbance of the ground or other inaterial being tam'ped.
To cause the root of each tam er to function as described, it is necessary that the foot element be alined on the shank II, with the heel 20 forwardrnost and the toe 2| rearwardm-o'staboutthe periphery of the roller. To facilitate and insure such'alinement the aforedescr-ibedgrooves l are provided on the shank H and tongues 22,;22 on the inner periphery of the collar ll. These tongues 22 likewise are formed at diametrically opposed points on the inner side of the collar H. Furthermore, they increase in thickness from their inner ends outwardly to correspond to the increase in depth of the grooves I5. By thisconstruction of grooves and tongues the latter have sliding interfitting engagement with the grooves for initially fixing the circumferential position of the collar on the shank. The inner ends of the tongues terminate in shoulders 23, which, in the inner extreme portion of the collar on the shank, may abut the shoulders P6 of the grooves. As shown, the tongues and grooves are formed on the side portions of the collar and shank but obviously they may bedisposed at "any other point,
about the periphery of the two. v v V In practice, the shank elements S of a multiplicity of the tampers are welded at their bases to the outer periphery of the roller R so as to project radially therefrom and preferably in rows extending circumferentially and longitudinally about the roller. To each shank element S is applied a foot element F by placing the collar I! on the shank I 1 and then turning the collar until the tongues 22 register with the grooves 15, when the collar can be slid inwardly on the shank to a point where the tapered walls of the collar and shank have frictional contact one with the other. By now driving the collar on the shank the two are caused to have such tight wedged engagement with each other as to lock the foot element on the shank element against any possibility of accidental displacement of the foot "element during rotation of the roller. Should it be necessary to remove and replace any one of the foot elements, it can be readily detached by driving it outwardly lengthwise of the shank to free it therefrom. A new foot can now be quickly applied and properly positioned on the shank through the alining action of the tongues and grooves.
Referring now to Fig. 5, I have here shown another form of sheep foot tamper embodying a complete reversal of the parts comprising the tamper shown in Fig. 1. Such reversal consists in forming the base I 3 with an interiorly tapered collar l1, and the foot l8 with a tapered shank Il Similarly, the collar Il is formed with tongues 22 and the shank with grooves l5 in which the tongues are received to aline the foot I 8 on the collar-Il The purpose of this reversed arrangement of parts is to avoid forming all parts of the tamper of cast steel as in the first form of my invention. With the reversed arrangement it is likewise necessary to form the base I3 and the collar ll of cast steel to permit welding of the base to the roller. However, the foot I8 the integral body Ill and the shank ll may all be formed of cast iron Without the liability of the iron shank being broken during use on the roller. is avoided by reason of the fact that the tapered iron shank, being as it is, telescoped'within the steel collar, is compressed by the collar to strengthen the shank rather than weaken it.
Although I have herein shown and described grooves and tongues as the means embodied in the 'telescop'ed interconnection of the foot and base of either tamper for alining the foot and collar on the shank or the roota'nn shank on the collar, it is to be understood that other alining means may be employed without' depar'ting from the spirit and scope of my invention 'so long as such alining means permits of the tight tapered engagement of the shank and collar to secure the shank within the collar against accidental uncoupling.
I claim: 7
1. A sheep foot tam er, comprising "a fnetal base, a collaron the base having an internal taper, tongues on the inner periphery ofsaid collar extending lengthwise thereof, a metallic foot havinga shank tapered-at its outer end "to conform to the internaltaper of said collar, said shank having grooves lengthwise therein to 'sl idably' receive said tongues.
2. In a sheep foot tamper; a base and a foot; a tapered shank member formedon said base, and a collar member formed on said foot-and taper-ed internally to have detachable telescopic wedge engagement "with said shank member; and coacting means on said members for aiming said foot on said base, said means having spaced surfaces longitudinally and in parallelism with the major axis of said members, so that the shank member can be telescoped'into and frictionally locked in the "collar member only when the foot is alined on the base.
3. In a sheep foot tamper; a base and a foot; a tapered shank member formed on said base, and a collar member formed on said foot and tapered internally to have detachable telescopic wedge engagement with said shank member; and coacting means on 'said members for alining said foot on said base, said means comprising a pinrality of spaced longitudinal tongues on one oi said members, and said other member having a plurality of cooperating spaced longitudinal grooves therein.
JOHN -J. LO'W.