CA2245309A1 - Studded traction assist strip - Google Patents

Abstract

A studded traction assist strip for providing emergency traction in the event of snow or ice conditions resulting in a stuck vehicle. The strip includes a generally flat and thin elongate body formed from a resilient rubber material. The body further includes a road facing surface and a wheel facing surface. The road facing surface including a plurality of metal studs extending therefrom for gripping icy surfaces, and the body further includes a plurality of transverse grooves for gripping when said body is in an extended position and to facilitate forming a compact roll for storage when the traction strip is not in use. In a further embodiment, a plurality of gripping elements extend through the body for gripping underlying icy surfaces. The gripping elements including a head extending from the wheel facing surface, and a root extending from the road facing surface. The gripping elements are sized and shaped to transfer force from the wheel of a vehicle riding over the body to the underlying icy surface.

Description

Title: STUDDED TRACTION ASSIST STRIP
FIELD OF THE INVENTION
This invention relates generally to the field of traction assist strips of the type that may be used in icy or snowy conditions to provide extra traction to a vehicle whose wheels are slipping because of ice, snow or the like. In particular, this invention relates to a traction assist strip of the type that may be inserted between a wheel and the surface to provide additional traction.
BACKGROUND OF THE INVENTION
In the northern climates motorists, of both cars and trucks, have to contend with snow and ice conditions. Often, snow and ice will accumulate around a vehicle at a time when the vehicle is stationary. Other times, a vehicle may drive into an unplowed area where the snow or ice is so deep, that the vehicle is required to slow down or stop. Owing to the significant inertia of a car or truck, in the event that it is stopped in snow or ice conditions, it can be difficult to reestablish sufficient traction between the wheels and the road surface to cause the vehicle to again move. This is especially true for vehicles which may stop on inclines, such as for example on a hill or the like. Even very slight grades can become impassable under slippery conditions.
When cars become stuck, it is often necessary to get out of the car and physically push the car through the snow or ice until better traction is available for the drive wheels. In cases where the vehicle operator is alone or not physically strong, there may be no way to cause the vehicle to move.
This can create safety problems, because the vehicle operator may then be left exposed to the cold weather without being able to reach the safety of a heated building. Alternatively, in running the vehicle engine there is a risk of being exposed to carbon monoxide poisoning from the engine fumes.
Such dangers cause people to avoid travelling in extreme conditions where possible, but it is not always possible. Thus every winter thousands of motorists end up stuck or trapped by snowy conditions.
In the past, various devices have been proposed for avoiding these problems by providing devices intended to improve the traction of the vehicle in snowy or icy conditions. For example, U.K. patent application 2,087,320 in the name of Alvers, which was published May 26, 1992, shows a mat for preventing wheel slip. The mat comprises low-density polythene, and is in the form of a rectangular sheet approximately 0.4" thick, 9" wide and 30"
long. Extending adjacent to the side edge margins of the sheet on both sides are longitudinal ribs and transversely extending on both sides of the sheet are transverse ribs. The ribs are approximately 2.5mm thick and 2.5mm high.
While providing some assistance, this design is inefficient in that in cold conditions, low-density polythene can also become hard, brittle and even, if cold enough slippery. Further, low widely spaced transverse ribs of the device are not substantial enough, nor effective enough, in providing traction in extremely icy conditions for example.
Other devices have been proposed which are in the form of a rug-type traction mat (U.S. patent no. 3,008,643 dated November 14, 1961 ), a traction strip including a sheet of flexible material and a plurality of equally sized metal channels, (U.S. patent no. 4,211,366 dated July 8, 1980), and a traction pad having a rectangular mat portion with one end provided with a wedge shape and having groups of substantially conical shaped projections extending from both sides of the mat, (U.S. patent no. 4,223,835 dated September 23, 1980). Each of these prior devices, while addressing some concerns, does not provide a fully adequate solution.
SUMMARY OF THE INVENTION
What is required is a simple, inexpensive traction assist strip which can provide sure traction in even the slipperiest conditions, including sheer ice.
Preferably such a traction assist strip would be easily fabricated, and yet be sturdy enough to withstand difficult cold weather conditions. The traction assist strip should include high frictional coefficient materials, such as rubber, rather than plastic, which will not change in characteristics over the temperature range of most weather. Additionally, the strip should include gripping assistance for the most extreme icy conditions, such as metal studs. As well, the strip should be easily and compactly storable, so that it can be kept at hand in case of an emergency.
According to the present invention there is provided a traction assist strip for providing traction to a vehicle tire, said traction assist strip comprising:
a generally flat and thin elongate body formed from a resilient rubber material;
said body including a road facing surface and a wheel facing surface; and a plurality of gripping elements extending through said body for gripping underlying icy surfaces, said gripping elements include a head exposed on said wheel facing surface, and a free end extending from said road facing surface, said gripping elements being sized and shaped to transfer force from a wheel of a vehicle riding over said body to said underlying icy surface.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the attached drawings in which preferred examples of the instant invention are discussed, by way of example only, and in which:
Figure 1 is an isometric view from above of a traction assist strip according to the present invention;
Figure 2 is an edge view of the traction assist strip of Figure 1;
Figure 3 is a bottom plan view of a portion of the traction assist strip of Figure 1;
Figure 4 is an enlarged view of an end detail of the traction assist strip of Figure 1.

Figure 5 is a schematic view of a preferred pattern on the upper surface of the traction assist strip of Figure 1.
Figure 6 is an edge view of a traction assist strip according to the present invention;
Figure 7 is a bottom plan view of a portion of the traction assist strip of Figure 6; and Figure 8 is a view from above of the top surface of the traction assist strip of Figure 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Figure 1 shows a traction assist strip or mat, generally identified as 10.
The traction assist strip 10 has a lower, road facing surface 12, and an opposite upper, wheel facing surface 14. The traction assist strip 10 is in the form of a body which is generally elongate and thin, having side edges 16 and ends 18. Preferably, the length of the strip when used for passenger automobiles, is 48", the width is approximately 8", and the height is about 3/4 of an inch. A larger truck size can also be used which is 48" long and 24" wide as well, to comfortably fit under the dual wheels of a typical truck.
Of course these dimensions are offered as guidance only and particular vehicles having nonstandard dimensions could require other widths of traction assist strip.
In a first preferred embodiment, shown in Figs. 2, 3, and 5, the upper surface 14 is preferably provided with a pattern, for improving traction. The preferred pattern is in the form of hexagonal imprints 15, about 0.25 inches across, which are pressed into, or pressed out of the upper surface 14. An example of such a pattern is shown in Figure 5. These patterns need not stand very proud of the surface, and may be thought of as merely being dimpling which extends up about 1/32 to 1/16 of an inch.
Referring to Figure 2, an edge detail of the traction assist strip 10 is shown. Preferably, the traction assist strip 10 is provided with a plurality of transverse grooves 20, which extend fully from side to side of the strip. The most preferred transverse grooves are 3/16 of an inch wide and 1/8 of an inch deep. Also, it is preferable that the grooves are formed with acute bottom corners, shown at 21 and 22. These bottom corners assist in gripping, and thus sharp 90° corners are preferred to rounded corners.
Also shown in Figure 2 is a stud 30, of the type that has a protruding metal head 32, a base flange 34, and a pointed threaded root 36. Ideally, the stud is threaded into the body of the device between grooves. It is preferred for each stud 30 to include a keyway, such as slot 38 for facilitating screwing the stud into the body of the traction strip. Additionally, the slots 38 may assist in providing traction in the event the slots 38 are transversely oriented.
As shown in Figure 3, a regular pattern of studs can be employed, wherein the studs are placed in transverse rows every 4", with each stud being 2" apart from its neighbor in the row. Also, it is preferable to indent the start of the rows from the side edges of the strip 10 , by about 7/8 of an inch. In the most preferred form of the first embodiment of the invention, there are provided approximately 48 such studs.
Also as can be seen in Figure 3, a plurality of transverse grooves are formed, ideally about 3/4 of an inch apart. It will be appreciated by those skilled in the art that the precise dimensions given can be varied without departing from the scope of the invention as defined in the attached claims.
A second preferred embodiment is shown in Figs. 6, 7, and 8. This embodiment has a similar overall form, but different preferred dimensions from the first preferred embodiment. It can also contain transverse grooves 20 on the road facing surface 12 of about 1/4" wide. The overall length may be 24" with 24 studs embedded within.
As shown in Fig. 6, the second preferred embodiment is distinguished by the use of gripping elements or bolts 46 that penetrate both the wheel facing surface 14 and the road facing surface 12. The bolts 46 have a protruding head 48 that is exposed on the wheel facing surface 14, a base nut 50, and a free end 52 that extend below the road facing surface 12. In this sense _$_ 15, although such a pattern may still be provided. The free end 52 preferably protrudes about'/2" below the road facing surface, and may be provided with a pointed end similar to the pointed threaded root 36 used with the first embodiment as shown in Fig. 2. As shown in Fig. 7, the bolts 46 can be employed in a regular pattern similar to the spatial arrangement of the studs 30 in Fig. 3. Fig. 8 shows a view looking down on the top of the wheel facing surface 14. The protruding heads 48 of the bolts 46 are arranged, as shown, four to a row with each row transversely placed about 4" apart.
The second preferred embodiment has the advantage of providing greater ground gripping engagement because of the protruding heads 48.
Snow and ice typically comprise a layer which may vary in thickness and is likely uneven. The flexible mat of both embodiments may lie closely over any ruts of surface irregularities. Absent the protruding head 48, the weight of the wheel is generally spread across the surface of the mat. However, when the mat with protruding heads 48 is used, the weight of the wheel on the protruding 48 causes a local high pressure on the flexible mat, causing the mat to collapse or deform more. This has the beneficial effect of allowing the lower protruding end of the bolt 46 to extend further down, allowing it to bite into the underlying layer of ice and snow.
Furthermore, by having the protruding head 48 extend above the surface of the compressible mat, the full pressure of the vehicle tire is passed directly along the rigid bolt body into the ground. Thus, in addition to providing the extension noted above, as the bolt 46 is a rigid body, and as the protruding head 48 is proud of the wheel facing surface, the full weight on the protruding head 48 is passed to the lower end. This also facilitates gripping.
Additionally, the second preferred embodiment presents a larger and sharper-edged contact area with snow and ice on the road facing surface 12 by its use of the protruding free end 52 rather than the head of a hexagonal nut. This further enhances gripping.

exposed means that the head can be contacted by a wheel, but this term covers a head that is countersunk into the wheel facing surface. The most preferred form is for the head 48 to be proud of the wheel facing surface as shown. In order for the gripping element 46 to be more securely attached to the mat, it is preferred that the protruding head 48 and base nut 50 both have a cross-sectional area larger than the area of the free end 52. Most preferably the base nut 50 is in the form of a nylon lined lock nut to prevent unintentional loosening of the base nut 50. Various sizes of steel bolts may be used, and in particular it has been found that 1" to 1'/2" inch long, having a'/" diameter sized bolts provide adequate results. Those skilled in the art will appreciate that other bolt sizes will also work, if there is sufficient bolt length to permit the weight of the car to be transferred from the road facing surface to the underlying icy surface.
It is also preferable that the gripping elements or bolts 46 possess certain characteristics of composition and structure. As the traction assist strip is used in conditions of snow and ice, it is preferable that the gripping elements or bolts 46 be composed of a material that has characteristics of being resistant to corrosion and oxidation, or to any decay from water contact.
Further, the gripping elements or bolts 46 should also be constructed to be sufficiently rigid so as to impart force from the weight of a passenger car or a dual wheeled truck to the underlying icy surface, and to cut into the icy surface, without buckling. Stainless steel is a good example of a preferred material that possesses these desirable characteristics of both corrosion resistance and structural strength. Other steels may also be used, provided they have sufficient strength and corrosion resistance such as a grade five standard bolt.
The protruding head 48 preferably extends about 1/8" above the surface of the wheel facing surface 14, and preferably has a plurality of edges, for example a hexagonal shape, to aid in gripping by the slipping wheel. Due to the presence of the protruding heads 48 on the wheel facing surface, there is no particular preference for this surface to have an imprinted pattern _g_ The second preferred embodiment also provides a more secure attachment of the gripping element 46 to the mat. By being more secure on both top and bottom, the possibility of the bolts 46 being expressed out of the mat, underthe combined effects of distortion and torque from the vehicle tire is reduced to a large measure. Thus, for good results, the gripping elements or bolts 46 are sized and shaped to transfer wheel load directly to an underlying icy surface.
Lastly, as the second preferred embodiment uses a strip of the same overall material, dimensions, and thickness, and also contains the same transverse grooves 20 as the first preferred embodiment, the strip can be rolled with equal facility.
Turning to Figure 4, an end detail is provided for all of the preferred embodiments of the traction assist strip. As can be seen, at least one end of the traction strip is preferably bevelled as shown at 40, to facilitate inserting the end of the traction strip 40 between a vehicle wheel (shown as 42 in ghost outline) and the ground, shown as 44. While the extent of the bevel could vary, a 45° angle, with a side of approximately 1" or 1 1/4" long, provides reasonable results. Of course the preferred bevel is one where the thickness tapers to a point at the road facing surface, to form a slight ramp, as shown. A bevel in the opposite direction, which could form a small overhang could also work, but is less preferred.
It can now be appreciated that the body of the traction strip is most preferably formed from a high-density rubber material. Most preferably, the high-density rubber material has a Shore durmoeter rating of between 65 and 75 on the A scale. In particular with respect to the embodiment of the traction assist strip shown in Figs. 2 and 3, it will be appreciated that the body is preferably made from a material that is sufficiently dense and is of a sufficiently integral material that it can adequately grip the threads of the root 36 of the stud 30 under adverse conditions. In other words the studs 30 must be mounted into the road facing surface of the body in such a manner that sufficient shear strength is provided to prevent the studs 30 from ripping out under use in actual conditions. The embodiment shown in Figs. 6, 7, and 8 also benefits from use of such a sufficiently dense and integral material. The most preferred form of achieving this is to use the relatively high density rubber noted above which is sufficiently strong and has provided reasonable results. Other alternatives include using reinforcing elements to provide additional strength for materials which have a lower shear strength. It can now be appreciated that plastics which become brittle under cold temperatures are not satisfactory for this purpose.
The preferable material for the body is a form of rubber, with the most preferred form being rubber of the type that is recycled from old automobile and truck tires, and from trim and flashings from other rubber products. This rubber is a high-density material, is very durable and has sufficient shear strength, and has a high frictional coefficient for vehicle tires, even at extreme cold temperatures. Additionally it remains relatively flexible at extremely cold temperatures aiding in the ability of the strip to be placed in position in spite of uneven ground or snow conditions immediately adjacent the tire for which traction is being provided. Additionally, being recycled, it can be obtained at a reasonable cost and prevents waste by way of unnecessary disposal. Thus, recycled rubber is the most preferred material from which to make the traction assist strip of the present invention.
It can further now be appreciated that the transverse grooves provide an additional function to gripping the surface. When the high-density rubber traction pad is to be stored, it is preferred to be rolled into a tight bundle.
The strip 10 when made of the preferred thickness and from the preferred rubber according to the present invention is somewhat stiff (although still flexible) and therefore, can be difficult to roll into a tight roll. A tight roll is preferred for storage reasons. The transverse grooves act to increase the bending ability of the traction assist strip (in the manner of living hinges) thereby facilitating the storage of the traction assist strip in a tight roll.
By being compact and secure, the traction assist strip can be easily stored in a trunk or the like in a rolled up manner.

It will also be appreciated that the transverse grooves can be formed in the wheel facing surface, in addition to or in substitution for those formed in the road facing surface as shown in the figures. Generally it is preferred to roll the strip with the studs pointing inwardly, because the studs are quite aggressive and if they are left extending out of the roll, they can cause some damage to adjacent equipment. This is especially true if the roll is stored in a trunk or the like and is bounced around during use of the vehicle.
Outwardly extending studs would be undesirable for being likely to cause scarring of the adjacent surroundings.
It will be appreciated by those skilled in the art that various modifications and alterations can be made to the invention without departing from the broad scope of the appended claims. For example, while the preferred material is recycled tire rubber, other high-density rubbers may also provide adequate results, if they provide enough strength to grip a threaded stud or bolt and have a high enough coefficient of friction to provide the needed traction to vehicle tires.

Claims (29)

1. A traction assist strip for providing traction to a vehicle tire, said traction assist strip comprising:

a generally flat and thin elongate body formed from a resilient rubber material;
said body including a road facing surface and a wheel facing surface;
and a plurality of gripping elements extending through said body for gripping underlying icy surfaces, said gripping elements including a head exposed on said wheel facing surface, and a free end extending from said road facing surface, said gripping elements being sized and shaped to transfer force from a wheel of a vehicle riding over said body to said underlying icy surface.

2. The invention of claim 1 further including at least one bevelled edge to facilitate inserting the body between a wheel and a surface.

3. The invention of claim 1 wherein said gripping elements are bolts with free ends.

4. The invention of claim 3 wherein said bolts include a hexagonal head to facilitate threading said bolts into said body.

5. The invention of claim 1 wherein said body is formed from high-density rubber.

6. The invention of claim 5 wherein said high-density rubber is recycled rubber.

7. The invention of claim 5 wherein said high-density rubber is made from rubber having a Shore durometer rating of about 65 to 75.

8. The invention of claim 5 wherein said high density rubber is sufficiently strong to retain said gripping elements in place during use.

9. The invention of claim 1 wherein said gripping element is secured by a head in contact with the wheel facing surface and by a base nut in contact with the road facing surface, said head and said base nut both having a cross-sectional area larger than the area of the free end of said gripping element.

10. The invention of claim 9 wherein said head extends from said wheel facing surface and is sized and shaped to facilitate gripping of the wheel facing surface by the vehicle tire.

11. The invention of claim 10 wherein said head is shaped and said shape is a hexagon.

12. The invention of claim 3 wherein the portion of said gripping element that extends from the road facing surface is sized and shaped to facilitate gripping of the underlying icy surfaces.

13. The invention of claim 1 wherein said gripping elements are sized and shaped to be large enough to facilitate gripping of both the vehicle tire on the wheel facing surface and the underlying icy surfaces on the road facing surface, and also small enough to enable the traction assist strip to fold into a compact roll for storage.

14. The invention of claim 13 wherein said gripping elements are sized and shaped to be small enough so that a plurality of gripping elements may be inserted across the width of the traction assist strip, and so that in typical use a plurality of gripping elements will make contact with the vehicle tire.

15. The invention of claim 14 wherein said gripping elements are arranged in rows of four across a traction assist strip that is approximately 8" wide, said rows being spaced approximately 4" apart.

16. The invention of claim 1 wherein said head extends approximately 1/8" from the wheel facing surface and said free end extends approximately 1/2" from the road facing surface.

17. The invention of claim 3 wherein said gripping elements are bolts or about 1 1/2" long.

18. The invention of claim 3 wherein said gripping elements are composed of a material that is resistant to corrosion and oxidation.

19. The invention of claim 18 wherein said gripping elements are made of grade five steel.

20. The invention of claim 1 wherein said gripping elements are constructed to be sufficiently rigid to impart force from the weight of a vehicle to the underlying icy surface, without buckling.

21. The invention of claim 1, further including transverse grooves formed on said body.

22. The invention of claim 21, wherein said transverse grooves are formed on said road facing surface to facilitate gripping of the underlying icy surface.

23. The invention of claim 21 wherein said transverse grooves have a depth of between 0.1 and 0.3 of the thickness of the body.

24. The invention of claim 21 wherein said grooves extend fully from one side of the body to the other.

25. The invention of claim 21 wherein said grooves are spaced between 1" and 3/4" apart.

26. The invention of claim 21, wherein said gripping elements are positioned on said body, not in said grooves.

27. The invention of claim 1, wherein the position of the gripping elements and the presence of said transverse grooves facilitate forming the traction assist strip into a compact roll for storage.

28. The invention of claim 1 wherein said traction assist strip is sized for passenger cars and is approximately 24" long and approximately 8" wide.

29. The invention of claim 1 wherein said traction assist strip is sized for dual wheeled trucks and is approximately 48" long and approximately 24"
wide.