US3160190A

US3160190A - Snow tread

Info

Publication number: US3160190A
Application number: US251698A
Authority: US
Inventors: Daniel N Jediny
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-01-15
Filing date: 1963-01-15
Publication date: 1964-12-08
Anticipated expiration: 1981-12-08

Description

United States Patent O M 3,160,190 SNOW TREAD Daniel N. Jediny, 212 Washington Ave., Garfield, NJ. Continuation of application Ser. No. 156,320, Dec. 1, 1961. This application Jan. 15, 1963, Ser. No. 251,698 Claims. (Cl. 152-209) This application is a continuation of my application Serial No. 156,320, led December 1, 1961 now abandoned, and relates to snow treads for solid or pneumatic tires or for crawler plates.

I provide by my invention a novel snow tread through which effective traction on snow or ice-covered ground is obtainable without sacrifice of smooth riding performance on clear road surface.

I contemplate a snow tread which during travel on snow or ice will develop from the snow or ice particles a tread-entrapped pattern of peripheral -icy cleats for increasing traction, relying on the fact that snow or ice coheres with itself, by a process of fusion, more durably than with any other substance.

My invention provides a snow tread in which the tread surface is interrupted by la pattern of recesses or cells opening substantially at the tread surface to induct snow or ice particles during travel on snow or ice-covered ground, each cell internally structured to entrap, retain, and mold the inducted frozen material into a compact, congealed, icy mass which, by reason of preferential adherence thereto of ground snow or ice particles, will build up outwardly into an eifectively peripherally protrusive ice-like cleat lacting like a permanent cleat of metal or plastic but having the great advantage of disappearing upon transition of the tread toy a clear ground surface.

According to my invention, entrapment of the snow or ice particles within the tread cell is preferably effected by dimensioning the cell with an internal girth exceeding the size of its intake opening, l may provide for Such relation between the internal girth of the cell and the size of the opening by indenting or notching the side wall or walls of the cell but preferably I propose to are one or more of the sides of the cell toward the inner end, providing a cell having the shape of the frustrum of a hollow cone or pyramid. Alternatively, my invention contemplates entrapment `of the snow or ice particles Within the cell by a supplemental trapping device inside the cell. Such trapping device may be a porous, tined, or mesh structure. Each cell may be supplied with its individual trap, or a plurality of the cells may be respectively supplied with trap elements consisting of portions of a common web or net, of wire or plastic, extending through solid tread rubber from one cell to =and across another. I further contemplate that both a larger internal girth of cell and supplemental trapping means may be used together for maximum entrapping effect on the snow or ice particles inducted through the cell intake end.

My invention contemplates the use of either an unlined tread recess or cell or, for maximum traction on dense snow or ice, the lining or formation of the cell by metal or plastic material. Such lining may be along one or more walls of the tread recess.

It is a characteristic of the cleat breeding recess or cell of my novel snow tread that its side Wall or walls are to have effective rigidity for maintaining the intake or outer end open under the weight of the vehicle equipped with the snow tread, whereby the intake end will be prepared to induct snow or ice particles during travel on snow or ice-covered roads. The desired rigidity may be attained through use of the metal or plastic lining inside the recess or by proportioning the recess with a large intake opening relative to the depth of the recess. A preferred proportion is one in which the mean dimension of 3,160,190 Patented Dec. 8, 1964 the intake opening is in the order of twice the depth of the recess. This proportion provides the requisite rigidity and also has the advantage of avoiding wedging and retention of stones, commonly spherical, inside the recess.

According to my invention, the inner or blind end of the cleat breeding recess in my novel snow tread is provided with a projection pointing toward the outer, open end and serving to divent and deflect inducted snow or ice material toward the sides of the recess so as to facilitate and insure the molding of the material into the entrapping shape of the recess.

I contemplate that the cleat breeding recess may be disposed longitudinally or transversely of the direction of tread travel or both longitudinally and transversely, as in the case of individual recesses within the tread.

According to my invention, each recess may have a separate lining or a plurality of the recesses may be formed around protruding cells of a metal or plastic web imbedded in the tread rubber, these cells then serving as linings for the plurality of recesses.

Other objects and advantages of my invention will appear from the subsequent description, the claims, and the drawings, wherein:

FIG. l is a vertical section through a portion of one form of my novel snow tread, this portion being shown in riding traction on snow and with already developed impermanent congealed snow cleats;

FIG. 2 is a detail section through an unlined cleat breeding recess of conical frustrum shape;

FIG. 3 similarly shows a conieally lined cleat breeding recess or cell;

FIG. 4 is an outside, broken view of a fragment of the rim of a snow tread formed with an illustrative pattern of recesses at least some of which are internally provided with snow entrapping meshes;

FIG. 5 is a section along line 5-5 of FIG. 4;

FIG. 6 is a section along line 6-6 of FIG. 5;

FIG. 7 is an outside, broken view of a small fragment of my novel snow tread with recesses formed around projecting cells of a web embedded in the tread rubber; and

FIG. 8 is a section along lines 8-8 of FIG. 7.

Referring particularly to FIG. 1, the snow tire there indicated is provided in its tread layer 10, of rubber, with one or more circumferential arrangements of individual cleat breeding recesses 11. Each recess 11 is characterized by an internal girth greater than the area of the open outer end, the shown recess having this characteristic by virtue of being shaped conically, as in FIG. 2, or pyramidally, as in FIG. 6, with its smaller end being the open end along the tread surface or plane. The side walls of the recesses have effective enough rigidity to maintain their outer open ends open under riding pressure. Such rigidity is obtained for the shown recess by la recess depth in the order of one-half the mean dimension of the outer open end. This proportion gives the necessary rigidity and also prevents stones from lodging in the recess.

The convergence of the recess 11 toward the open end serves to entrap snow or ice inducted into the recess. As the vehicle equipped with the snow tread rides on a snowcovered road, `the ground snow is forced by the Weight of the vehicle and load into the recesses meeting the snow. The snow forced into the recess is softened by the warmth of the tread and by the friction of compression and packs under pressure into a dense, ice-like mass molded to the internal shape of the recess and since this shape is convergent toward the periphery of the tread, the resulting molded icy slug is entrapped in the recess. In order to aid and insure the molding of the inducted frozen material to the shape of the recess, the inner end of the recess is formed with a projection 12 pointing toward the intake opening and serving to divent ntruded snow toward the side wall or walls of the recess.

When the icy slug entrapped in a recess 11 again meets the ground snow, its moist exposed end almost immediately unites or fuses with a quantity of the ground snow, a cohesive freezing between the exposed surface of the entrapped icy slug and the contacted snow taking place under riding pressure and as the excess heat in the area of contact between the slug and the ground snow rapidly diifuses into the surrounding snow on the ground. At this point, it may be noted that the cohesive force or adhesion between the snow and the exposed surface of the entrapped icy slug far exceeds the adhesion between the snow `and the tread rubber between recesses and is of considerably more durable nature. The accretion, by fusion, of ground snow to (the exposed end of the entrapped icy slug in the tread has the effect, in itself, of improving traction of the tread over the snow, since the accreted icy slug already begins to act as a cleat. When the portion of the Itire with the icy slug turns up and away from the ground, a forcible separation of the slug together with its accreted quantity of snow takes place with respect to the ground snow, and a next recessed portion of the tire turns into the snow.

Thus, during turning of the snow tire, each of the recesses 11 meets and presses into the ground snow and inducts -a quantity of snow which molds into an icy slug entrapped in the recess. As the tread continues its travel over the snow, each of 'the entrapped icy slugs grows outwardly by successive accretions of ground snow over and around the exposed end, into an icy cleat designated C in FIG. 1. A pattern of ice-snow cleats C thus is built up at spaced positions on the tire rim, by preferential adherence or coherence of the ground snow with the entrapped icy slugs in -the recesses 11. These impermanent cleats C promote traction over the snow-covered ground by reason of their cohesive action with the ground snow and by reason of their penetration into the snow. The amount of snow accumulated on the entrapped icy slug in a recesses 11, or the size of the protruding portion of the ice cleat C, depends on the number and arrangement of the recesses and, also on the temperatures of the ambient air, the tread and the ground snow, and on the density and depth of the ground snow.

When the tread and its developed pattern of cleats C encounter ground thinly covered by snow or ice, the cleats accumulate less and less of the snow or ice particles and diminish toward the plane of the tread. When the cleats have declined to the tread plane, there will still not be a complete loss of cleat-like traction because the remnant icy slugs captivated in the recesses 11 are relatively more rigid than the tread rubber and their outer edges will scrape any thin layers of ice or snow they encounter, imparting a gear like traction eifect to the tire. The scraped snow or ice particles also will serve to replenish the icy slugs and prevent their decline to less than eifective length.

When the tread passes from snow or ice covered ground to bare ground, the icy cleats C including the entrapped portions disappear by melting away due to the warmth of the tread generated by the riding friction. The tread then functions as a cleatless tread to provide smooth riding traction on the bare ground.

While the tread with unlined recesses functions effectively even on dense snow or ice, the lined recesses are preferred where dense snow or Vice-covered roads prevail. This is because the more rigid lining material will more eiectively scrape up dense snow or ice than the unlined recess.

The lining material may be metal or plastic. For the metal lining, spring metal or equivalent ilexible metal is preferred. Any suitable, hard, durable plastic, including hard rubber, may be used as lining material. The lining may be single, separate units for the respective recesses or may be multiple units formed from a common web.

FIG. 3 shows an example of a unit-lined cleat breeding recess in the tread. In the shown example, the lining unit 13 is an inverted conical frustrum fitted snugly into the receptive cavity in the tread rubber. Projecting tines 13a anchor the lining securely in place. The outer edge of fthe lining reaches substantially to the tread surface plane. Other shapes of lining may be used. For a pyramidal cavity, one or more of its side Walls may be fitted with a lining. The blind or inner end of the cavity or the lining for the cavity will be formed with a projection 13b serving the same purpose as the projection 12 in recess 11 (FIG. 2).

The linings for a plurality of cavities in the tread may be connected units, as indicated in the example shown in FIGS. 7 and 8. Here a web 15, either a continuous ring or a section of a ring and made of metal or plastic, is formed with projecting cells 15a. The cells may have any suitable snow-ice entrapping shape, pyramidal, conical, or the equivalent. As shown, the cells are open-ended conical frustrums. In the manufacture of the tire, the web 15 and cells 15a become imbedded in the tread rubber to the level of the outer, smaller ends of the cells. Provision is made for blocking both ends of the cells against intrusion of rubber except for a projecting intrusion 16 having the same purpose as projection 12 (FIG. 1) or projection 13b (FIG. 3).

When the snow tread formed with the lined cavities tnavels on relatively soft snow, the form-ation of icy cleats takes place the same as for a snow tread formed with unlined cavities. When the snow tread with lined cavities travels on packed or dense snow or ice, the sharp and unyielding outer edges of the linings scrape up packed snow or ice particles which accumulate in the lined cavities, condensing therein to form icy slugs molded to the entrapping shape of the lined cavities. By the same process described before, the icy slugs unite at their outer, exposed ends with further scraped up snow or ice particles and build up to protruding ice-like cleats which reach slightly beyond the tread surface. The size of the proltruding portion of the cleat is not as massive as When the cleat builds up from soft snow, for the reason that an ice-covered pavement or a pavement coated by densely packed snow presents an extremely hard surface. The entrapped cleats, though smaller, still serve through their cohesive coaction with the ground snow or ice, to provide improved, gear-like traction on the snow or ice-covered pavement.

Instead of relying on the shape of the cavity to retain the snow-ice mass which builds up into a cleat, -a trapping element may be used within the cavity. The trapping element may be individual to a cavity or may be a part of a trapping web extending through the tread rubber into a plurality of the cavities. As illustrated in FIGS. 4 and 5, a trapping web 17 is moulded within the tread body and reaches across longitudinal grooves 18 and individual, pyramidal recesses 19. The trapping web is of metal or plastic and may be a perforated web or a wire-mesh, as shown. The plane of the trapping element within a cavity is closer to the inner end of the cavity than to its outer, tread surface end, a small space being preserved between the trapping element and Ithe inner end of the cavity to enable snow or ice particles to pack solidly on both sides of the trapping element. The trapping membrane or mesh should be exible enough to prevent its being permanently crushed inwardly to the bottom of the cavity when the tire rolls over pebbles and small stones. Snow inducted in the cavi-

ty

18 or 19 during travel on a snow-covered road condenses on both sides of the wire mesh yand clings thereto, forming a nucleus for any icy slug which takes the shape of the cavity.

Entrapment of the snow in a cavity 19 is not only effected by the wire mesh but by the convergence toward the outer end of a pair of opposite side walls of the cavity, indicated in FIG. 6.

Also shown in FIGS. 4 and 5 is a longitudinal cleat breeding recess 20 which entraps snow by convergence 0f the side walls toward the outer, open end. The recess 20 is formed Iat the bottom with a longitudinal rib or projection 21 for deflecting the inducted snow-ice mass to the sides of the recess, insuring the molding of the inducted mass to the entrapping shape of the recess. Similarly, the

recesses

18 and 19 also may be provided with projections for the same purpose.

To prevent the congealed mass or cleat ice trapped in rthe longitudinal recess from slipping around the tire, the recess is interrupted at intervals along the length by cross pieces such as the cross piece 22 integral with the tread lrubber.

While the invention has been disclosed in connection with particular embodiments, it is understood that variations may be made without departing from the principle of the invention; therefore, I intend to be limited only as indicated by the following claims.

What is claimed is:

1. A snow tread for traction on snow or ice-covered ground as well :as on bare ground surface, said tread being characterized by a recess open at its outer end along the tread surface to induct snow or ice material during travel of the tread on snow or ice-covered ground, said recess being internally structured to entrap the inducted snow or ice material as a congealed, icy slug for uniting at its exposed end with further encountered ground snow or ice material to develop into an icy traction-promoting cleat.

2. The invention as defined in claim 1, the entrapping structure of the recess comprising a lateral wall structure of greater girth than the area of the snow inducting end.

3. The invention ias dened in claim 1, the entrapping structure of the recess comprising an inwardly ared lateral wall structure.

4. The invention as delined in claim 1, the entrapping structure of the recess being constituted by a pyramidal lateral wall structure converging toward the open outer end of the recess.

5. The invention as defined in claim l, the entrapping structure of the recess being constituted by a conical lateral wall structure converging toward the open outer end of the recess.

6. The invention as defined in claim l, said recess having an effectively rigid side wall structure for maintaining the outer end of the recess open under riding pressure.

7. The invention as dened in claim l, said recess being provided with a projection pointing from the inner, blind end of the recess toward the outer end to deect the inducted snow to the side of the recess and insure molding of the inducted mass to the internal shape of the recess.

8. The invention as dened in claim 1, said recess being lined with material of greater rigidity than the tread material.

9. The invention as deiined in claim 1, said recess being provided internally with a t-ted individual lining of material more rigid than the -tread material.

10. The invention according to claim l, the tread being formed with a plurality of individual recesses and a plurality of connected relatively rigid cells imbedded in the tread material and around which the individual recesses are formed, the cells serving as linings for said recesses.

11. The invention according to claim l, the snow tread being provided with a pattern of such recesses including a recess extending longitudinally along the tread rim.

12. The invention according to claim 1, the entrapping structure comprising a supplemental snow-ice trap element across the recess.

13. The invention according to claim l2, said trap element being Ia porous membrance crossing the recess be- -tween its inner and outer ends.

14. The invention according to claim 13, said membrane being a Wire mesh.

15. The invention according to claim 14, said wire mesh being a section of a web of wire mesh imbedded in the tread and extending therethrough :across a plurality of said recesses.

References Cited in the file of this patent UNITED STATES PATENTS 952,014 Morris Mar. 15. 1910 1,105,880 Cooper Aug. 4, 1914 2,424,647 Bernkull July 29, 1947 2,575,439 Billingsley Nov. 20, 1951 FOREIGN PATENTS 798,397 France Mar. 10, 1936 1,163,341 France Apr. 21, 1958

Claims

1. A SNOW TREAD FOR TRACTION ON SNOW OR ICE-COVERED GROUND AS WELL AS ON BARE GROUND SURFACE, SAID TREAD BEING CHARACTERIZED BY A RECESS OPEN AT ITS OUTER END ALONG THE TREAD SURFACE TO INDUCT SNOW OR ICE MATERIAL DURING TRAVEL OF THE TREAD ON SNOW OR ICE-COVERED GROUND, SAID RECESS BEING INTERNALLY STRUCTURED TO ENTRAP THE INDUCTED SNOW OF ICE MATERIAL AS A CONGEALED, ICY SLUG FOR UNITING AT ITS EXPOSED END WITH FURTHER ENCOUNTERED GROUND SNOW OR ICE MATERIAL TO DEVELOP INTO AN ICY TRACTION-PROMOTING CLEAT.