Anti-slip apparatus

[57] ABSTRACT

A film or web of rubber or the like is formed with patterns of small closely spaced vacuum cups on each of its faces. When compressed between two surfaces, both of which are smooth, the cups of the two faces grip the two respective surfaces to restrain slippage, but due to the small size of the individual cups, local release is prompt as the area of applied pressure shifts. In applications such as bathing sandal soles or baseball bat grips, Signed cups of the two faces may be vented each to each, so that vacuum release on either face of the gripping element automatically releases the other face.

Claim, 11 Drawing Figures

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PATENTED jul 18 tare

3,676,940

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3,676,940

ANTI-SLIP APPARATUS

The present invention pertains to improvements in anti-slip apparatus, being directed to means for preventing undue displacement or slide between two relatively smooth surfaces.

Over a period of years, vacuum cups have been applied to a variety of anti-slip devices, ranging from certain early automobile tire treads to modern bath mats and sport shoe soles. However, while articles such as the latter two types have been successful within their particular scopes, certain drawbacks inherent in the manner in which the cup principle has hitherto been applied have prevented realization of the later’s full potentialities as a measure of safety. For example, the usual mat having an under side layer of cups adapted to adhere to the bottom of a tub or shower bath furnishes a measure of safety, but that measure is limited to the immediate stationary area of the mat itself; numerous accidents occur when bathers step from the mats to adjacent slippery surfaces such as open tub bottoms or tile bathroom floors, the latter either bare or protected only by such hazardous makeshifts as towels or similar readily shiftable articles. To apply a vacuum mat to every danger spot on which a person may wish or chance to step has been too cumbersome for general practice; in fact, many an experienced traveller has been faced with accommodations having no safety mat whatever unless he has troubled to bring it himself.

The same dangerous condition occurs, often to even greater extent, in other locations such as the tile margins of swimming pools, particularly where children or young adults may be at play. Since, as noted above, it has been found impractical to supply the usual stationary vacuum mats to all potential danger areas, the logical conclusion is that the protection must be carried by the individual himself or herself in the form of footwear. Here again however, the forms of footwear hitherto available do not lend themselves to this purpose without interfering with the other requirements of the user’s activity, namely, quick and easy release of the vacuum grip, together with extreme lightness, ease of putting on and removal, and minimum restraint in walking, running or swimming. These deficiencies as to the prior art have been largely due to two related factors. In the first place, as typefied in sports shoes, the vacuum cups have been provided only on the bottoms of relatively stiff soles, so that the gripping effect by the soles is confined to the underlying engaged surface. Secondly, the sizes of vacuum cups employed have been relatively large, causing high localized gripping effects with correspondingly high energy requirements to effect release. As a result of these factors, it has been necessary to provide comparatively heavy upper means to retain the article firmly on the wearer’s foot, in order to avoid displacement and flapping as the vacuum grip is overcome. While, as previously mentioned, the above type of structure may be suited to ordinary sport shoes and the like, it would obviously be too cumbersome for use in the field of very light and thin slip-restraining devices as contemplated herein.

In view of the above and related considerations, an object of the present invention is to provide improved anti-slip apparatus including a flexible sheet-like element having means on both its faces for gripping both of two surfaces between which it may be compressed.

A further object is to provide apparatus of the above nature in which the gripping means on each face of the sheet-like element comprises a pattern of vacuum cups.

A further object is to provide an element of the above type in which each pattern is composed of a relatively large number of closely spaced cups of small individual dimension, so that local release of their gripping effect is readily accomplished as pressure is withdrawn therefrom.

Another object is to provide a gripping element of the above nature in which the two face patterns are matched back-toback, whereby the tensional effect necessary to release a cup of either face pattern may be supplied directly through its matching cup of the other face pattern.

A further object is to provide apparatus of the above type in which the cups on each face of the gripping element are vented to their respective backing cups on the other face of the element, whereby ready local release of the gripping effect may be facilitated.

A further object is to provide apparatus of the above nature in which the gripping element comprises the sole of an article of safety footwear.

Another object is to provide apparatus of the above nature in which the sheet-like element is formed as a sleeve adapted to serve as a non-slip gripping means for use on implements such as baseball bats and the like.

Other objects and advantages of the invention will become evident during the course of the following description in connection with the accompanying drawings, in which

FIG. 1 is a flatwise or plan view of a typical gripping sheet or element embodying the invention;

FIG. 2 is an enlarged sectional view in the region 2—2, FIG. 1;

FIGS. 3 and 4 are similarly enlarged sections showing alternative detail formations of the gripping element;

FIG. 5 illustrates the application of the invention to a device for restraining slippage between the ball of a bather’s foot and an underlying surface;

FIG. 6 similarly shows the invention embodied in a guard for the user’s heel;

FIG. 7 illustrates a form in which the non-slip element comprises the complete sole and under-heel portion of a foot appliance;

FIG. 8 is an enlarged view illustrating the compression of the gripping sole element between a user’s foot and an underlying surface;

FIG. 9 illustrates the ready local release of the gripping vacuum;

FIG. 10 similarly illustrates the gripping and ready release of the alternative form shown in FIG. 4, and

FIG. 11 shows the use of the invention in a non-slip grip for a baseball bat.

Referring to FIG. 1, the numeral 20 generally indicates an anti-slip element of soft rubber or equivalent plastic material embodying primarily a thin web 21. A pattern of closely spaced small vacuum cups 22 is formed on one face of the web 21, this face for convenience being hereinafter termed the upper face. Referring to the enlarged typical sections, FIGS. 2 and 3, it will be seen that a similar plurality of downwardly directed cups 23 is formed on the lower face of the web 21, the individual cups 23 being disposed in vertical alignment with respective upwardly facing cups 22. In the embodiment shown in FIG. 2, each pair of aligned cups 22 and 23 is interconnected via a central orifice 24 which serves as a vent between them.

FIG. 5 shows the manner in which the invention is embodied in an appliance 25 adapted to prevent or effectively restrain slippage between a smooth underlying surface and the ball of a user’s foot 26. As will be seen, the anti-slip element 20 comprises the bottom portion or sole of the appliance, a thin over-reaching band 27 being provided to retain the appliance in proper position when the device’s double gripping function is not in process, the latter as when the foot 26 is raised in stepping or walking. Similarly, in FIG. 6, the element 20 comprises the underlying portion of a heel guard 28, while in the form 29 shown in FIG. 7 the element 20 underlies the entire bottom surface of the wearer’s foot 26. (In ordinary prior parlance, the general form shown in FIG. 7 might be referred to as a “bathing slipper,” but as the term “anti-slip slipper” would constitute an obvious ambiguity, such nomenclature has been avoided herein.)

The manner in which the anti-slip element 20 performs its functions of localized clinging action and easy release is shown in greatly enlarged detail FIGS. 8 and 9, which for example typefy the relationships occurring when the user of an appliance such as those shown in FIGS. 5 or 7 applies the ball of his foot 26 to an underlying slippery surface 30. As the user’s weight is applied the foot naturally flattens somewhat, as shown in FIG. 8, compressing the element 20, so that the cups

3,676,940 and 23 are flattened in the area of pressure application, expelling a large part of their air or water content and thereby empowering them to exert the clinging effect characteristic of vacuum cups. It will be noted that the clinging effect is applied not only to the underlying surface 30 by the cups 23, but also by the upper cups 22 to the wearer’s foot 26; the latter provision prevents shifting tendency to displacement of the device from the foot, without requirement for relatively heavy fastening means.

FIG. 9 illustrates the easy releasing feature of the device. When a start to walk or a shifting of the wearer’s position causes the usual upward bending or rolling movement of the foot sole, the mechanical pressure is released from the cups 22 and 23 in the immediate zone of separation, so that the respective pairs of upper and lower cups in this zone tend to be expanded or drawn apart to release their joint clinging action, the anti-slip effect meanwhile being maintained by the remaining cups still under pressure. During release it is immaterial whether the upper or lower cup of each pair is first drawn out of sealing engagement with its respective adherent surface, since by provision of the connecting orifice 24, breaking the vacuum in either cup instantly releases the other. Due to the small actual size of the cups, (exaggerated in FIGS. 1, 8 and 9 as noted) the extent of separation necessary to release each pair is correspondingly small, so that the local resistance to release in turn is too small to cause any delayed jerking effect which could interfere with normal activity of the wearer, such as running along the margin of a swimming pool. Thus the device provides slip restraint in the immediate area of pressure application wherein the requirement for such resistance is localized, in other words, only where and when needed, eliminating any necessity for large stationary mats; at the same time, the top-and-bottom clinging action of the cup combinations themselves allows both the web 21 and the band 27 to be so thin and flexible as to cause no significant interference either with ready removal and replacement in bathing, or with swimming, walking or related activities as noted.

The anti-slip function described is brought about in the same characteristic manner by the heel guard appliance 28, FIG. 6, and by the combined or full sole version 29, FIG. 7.

In the alternative form of the anti-slip element 20α, shown in FIGS. 4 and 10, each pair of interconnected cups consists of a relatively large cup 31 and a matching smaller cup 32, the pattern being so arranged that the larger cups 31 of adjacent pairs are directed alternately upward and downward. This embodiment may be employed in cases wherein it is desirable to reduce the over-all thickness of the element 30α to a minimum, as illustrated in FIG. 10. The general operation is the same as that described above, except that due to their reduced areas the smaller cups 32 tend to release first, in a sense acting mainly as release valves for their connected larger cups 31.

FIG. 11 shows a typical use of the invention in an appliance other than footwear. In this example the element 20 is formed as a sheath 33 adapted to be employed as a non-slip safety grip on the handle 34 of a baseball bat 35. The form of bat in present popular use incorporates a handle portion so small in diameter that the user’s often perspiring hand grip thereon can readily become insecure, a fact made evident in the frequent accidental hurlings of bats into the ranks of spectators or players, with obvious danger of injury. The sheath 33, when compressed between the bat handle and the user’s hands, provides significant inner and outer vacuum gripping effect and consequent resistance to slip in the manner previously described; similarly, the described quick and easy vacuum release feature permits the batter to drop the bat at once after (and if) he hits the ball. Thus the device is adapted to provide protection against dangerous slip without the use of sticky pine tar or the like, though obviously it may be employed in conjunction therewith if desired. In addition to its anti-slip function, the resilient sleeve 33 cushions the batter’s hands against the danger of numbing or prolonged tingling effects frequently resulting from imperfect engagement of the bat with the ball, for examples, when the ball is hit either on the extreme end of the bat or just above the handle.

In the foregoing description the diagonal rectangular pattern of cup arrangement, as shown in FIG. 1, has been taken as typical. However, obviously any other pattern such as a circular, hexagonal, or spiral arrangement, may be employed when found advantageous in a particular form of appliance. Similarly, for particular services the pattern may include pairs of cups formed without direct interconnection, as shown in FIG. 3. Furthermore, it will be evident that slip-restraining advantages of the double faced vacuum gripping means may be employed in industrial as well as household and sporting appliances. Thus, while the apparatus has been described in preferred form, it is not limited to the precise embodiments illustrated, as various modifications may be made without departing from the spirit of the invention as defined within the scope of the appended claims.