METHOD FOR IMPROVING GRIPPING PROPERTIES OF FOOTWEAR, AND A DEVICE FOR UTILIZATION OF THE METHOD

Abstract: A method for improving the gripping properties of footwear in relation to a surface, and a device for utilization of the method. The invention can be applied to footwear having a sole of rubber, synthetic rubber or similar material, which can be reshaped when made subject to heat. According to the invention, the footwear is pressed against an electrically heatable pattern creating member (3, 3', 3'') during a predetermined period of time and/or until a predetermined depth of penetration has been achieved. As a further modification, the sole of the footwear is brought into contact with a granular material, e.g. sand, during the above operation, or as an immediately following operation.

Description: Method for improving gripping properties of footwear, and a device for utilization of the method The present invention relates to a method for improving gripping properties of footwear, and a device for utilization of the method. Particularly when roads are slippery, it is extremely desirable to use footwear having good gripping properties in relation to the surface on which movement takes place. In order to achieve this object, it is previously known to use frost-nails and similar engagement means, which normally are attached to the footwear by means of straps, arranged to project outwardly from the sole of the footwear. Such means for grip improvement are not always available, and must be attached/removed in accordance with the nature of the ground surface. To leave such means attached, when for example entering solid and hard floor surfaces, e.g. marble covered floors, increases the risk for injuries by slipping, and to perform attachment/removal operations in accordance with existing ground surface is difficult and time-consuming, particularly for elderly persons. As an alternative, footwear may be used having soles of rubber, synthetic rubber or similar material, which have an accentuated pattern with good gripping properties in relation to the ground surface. There is a disadvantage, since existing pattern in a relatively short period of time due to wear looses the original good properties, which can not be restored. The more such footwear is used, the risk is increased for injuries by slipping, and the cost involved for replacing the footwear by new footwear prevents such action with desired short intervals of time. The object of the present invention is to disclose a method, and a device for utilization of the method, eliminating the above discussed disadvantages. The present invention can be applied to all types of footwear having a sole ' of rubber, synthetic rubber or similar material, i.e. prevailing materials for soles of footwear intended for bad weather conditions. The main and characteristic features of the method according to the present invention are disclosed in the following main claim, and the characteristic features relating to a device according to the present invention are disclosed in the subclai s related to said device. The method according to the present invention is more fully described below with reference to an example of a basic embodiment of a device for utilization of the method as shown in the enclosed drawings, in which:- Fig. 1 shows a perspective view of an embodiment for utilization of the method according to the present invention, Fig. 2 shows the embodiment shown in Fig. 1 when used, and Fig. 3 shows a view of how footwear is affected by means of the device shown in Figs. 1 and 2. With reference to Fig. 1, the shown embodiment of a device according to the present invention includes a box-shaped base member 1, having a plate member 2 forming an upper plane, movable in relation to the box-shaped base member 1 as indicated by means of arrows. The plate member 2 is arranged with a number of through apertures, each one arranged surrounding a pointed member 3, 3 ' , 3" projecting towards the upper plane. A U-shaped member 4 is attached to an end portion of the base member 1, having two control means attached to the upper and interconnecting part. The box-shaped member 1 encloses an electrically heatable element, arranged to facilitate heating of the pointed members 3, 3 ' , 3", and a time circuit is also arranged, whereby the time period in which the electrically heatable element is connected can be predetermined. When used, the person wishing to improve the gripping properties of the footwear stands on the device, as shown in Fig. 2. The plate member 2, which is resiliency supported in relation to the box-shaped base member 1, is now depressed downwardly towards the base member 1, whereby the pointed members 3, 3 " , 3" project past the upper plane defined by the plate member 2. The extent of this movement is used as a measurement of the load imposed on the plate member to determine that the weight of the OMPl person exceeds a certain limit, e.g. 45 kg. Provided that this condition is fulfilled, an electric switching means enclosed within the box-shaped base member 1 is closed, forming a part of the electric supply circuit intended to feed a voltage to the electrically heatable element. To accomplish the above mentioned supply of voltage, it is further required that the person in question by means of the hands influences both control means 5, 5 ' , and that the weight influenced switching means is operated, in which case the electrical circuit for voltage supply to the electrically heatable element is closed. Simultaneously, the time surveillance circuit is operated, which after a predetermined interval of time interrupts the voltage supply to the electrically heatable element. To accomplish a subsequent voltage supply, it is required that both the control means 5, 5 " , comprising electric switching means, and the weight indicating switching means, return to uninfluenced positions, i.e. that the voltage supply circuit is interrupted at this three points. When voltage is supplied, the heat from the electrically heatable element is transferred to the pointed members 3, 3 ' , 3", and due to the load imposed by a person standing on the plate member 2, said member 2 is moved downwardly, thereby causing the pointed members 3, 3 " 3" to project a corresponding distance past the the upper plane defined by the plate member 2. The result is more closely illustrated in Fig. 3, in which figure the total number of pointed members 3, 3 ' , 3" are not shown. Said figure is only intended to illustrate how the sole 6 of footwear is affected during the time period when the pointed members 3, 3 ' , 3" are heated, and how these have penetrated the sole 6 and associated heel, thereby forming a wafer-shaped pattern. The material moved by the penetration of the pointed members 3, 3 " , 3" into the sole 6 and associated heel results in formation of parts projecting outwardly from the sole 6 and the heel, having fairly sharp portions, which considerably improve the gripping properties of the footwear. It should be mentioned, that the penetration of the heated pointed members 3, 3 ' , 3" into the footwear does not result in any loss of material in the sole 6 or associated heel, but only in reshaping of existing material. In order to further improve the gripping properties of footwear in ' BUREA OMPI vvi relation to a surface, the frictional properties may also be improved by means of a granular material, e.g. sand, spread out as a thin layer on the plate member 2. When a change in shape is accomplished by means of the heated pointed members 3, 3 ' , 3", the material of the sole 6 is obviously made soft, and granular particles penetrate the material, in which they are maintained. As a result, the sole 6 receives, apart from the previously discussed preferably wafer-shaped pattern, also a surface similar to abrasive paper, which results in extremely good gripping properties in relation to ice or other similar surfaces. For applications in which adjacently located but individual pointed members 3, 3 ' , 3" are used for reshaping soles 6 of footwear, and the associated heels, the plate member 2 may advantageously comprise of a grate-shaped member. However, also other types of members can be used for reshaping purposes, e.g. blade-shaped members having a straight or any other desired direction of extension, the plate member 2 obviously being arranged with through slots having an extension corresponding to said reshaping members. Furthermore, each reshaping member may also be arranged individually and resiliently movable in relation to the other reshaping members, in order to achieve compensation for the distance in line of extension existing between the sole 6 and associated heel in footwear. It has also been stated, that sand or other granular material may be applied as a thin layer covering the plate member 2, but it is also obviously possible to place a box of sand or similar material adjacent to the device, in which case the person who has accomplished reshaping of the footwear directly moves to the box-shaped member containing sand or similar material, whereby said material adheres to the sole 6, which has been made soft by heat. In order to avoid excessive application of heat to.the footwear to be reshaped, it is obviously possible to include a thermostatic control device, which during the heating stage maintains the temperature of the pointed members 3, 3 ' , 3" below a predetermined maximum level. As an example of a further modification can be mentioned, that the control means 5, 5 ' obviously can be located differently to what has been shown and described, e.g. attached against a wall surface. It should also be emphasized, that the safety devices disclosed above, a weight influenced switching means and manually operable switching means (the control means 5, 5 ' ), have only been included to increase safety when using the device, and that these completely or partly can be disregarded, or replaced by other similar means, intended to establish necessary safety with regard to unintentional connection of the power supply circuit to the heating element. Furthermore, it may also be advantageous to arrange the pointed members 3, 3 " , 3", or similar members used, coated by a material reducing the risk for adherance, e.g. a coating of the material marketed under the Trade Mark "Teflon". Previously mentioned time circuit, intended to avoid any risks for an excessively deep penetration by the pointed members 3, 3 ' , 3" into the footwear, may also be replaced by a surveillance circuit, which causes interruption of the voltage supply to the electrically heatable element when the pointed members 3, 3 ' , 3" have penetrated the footwear a certain and predetermined distance. Combinations of such a device for surveillance of penetration depth and of a time circuit may obviously also be used. The above description, and the disclosure of the drawings, only intend to serve as example of embodiments within the scope of the inventive thought and the following claims, and do not intend to serve as any restriction to a specific embodiment for utilization of the method according to the invention. OMPI

Claims: Claims 1. A method to improve the gripping properties of footwear in relation to a surface, c h a r a c t e r i s e d i n, that the sole (6) of the footwear is pressed against an electrically heated and pattern creating means (3, 3 ' , 3"), and that the pressure is maintained during a predetermined interval of time and/or until a predetermined depth of penetration has been achieved. 2. A method according to claim 1, c h a r a c t e i s e d i n, that in connection with the operation of pressure application, or as an immediately following step, the sole (6) of the footwear is brought into contact with a granular material, which thereby adheres against the sole (6). 3. Device for util zation of the method according to any one of claims 1 and 2, c h a r a c t e r i s e d i n, that it includes an electrically heatable pattern creating member (3, 3 ' , 3"), which when heated is pressed against the sole (δ) of the footwear, and maintained heated and pressed against the footwear during a predetermined period of time and/or until a predetermined depth of penetration has been achieved. 4. Device according to claim 3, c h a r a c t e r i s e d i n, that the electrically heatable pattern creating member (3, 3 " , 3") is arranged to extend through apertures taken up in a plate member (2), and that said plate member (2) is arranged to form an upper plane at the pattern creating member (3, 3 " , 3"), arranged to move in direction towards said pattern creating member (3, 3 ' , 3") when made subject to a load, whereby said pattern creating member (3, 3 " , 3") takes up a position extending past said upper plane. 5. Device according to claim 4, c h a r a c t e r i s e d i n. that an electrical switching means is arranged to form a part of the voltage supply circuit to the electrically heatable element which heats the pattern creating member (3, 3 ' , 3"), and that said means is arranged to close the voltage supply circuit when the plate member (2) is made subject to a load exceeding a predetermined limit. OMPI 6. Device according to any of claims 3 - 5, c h a r a c t e r i s e d i n, that at least one manually operable electric switching means (5, 5') is arranged adjacent to the device, preferably located at a distance in direction upwards from the device, and that said switching means (5, 5') when operated result in a supply of voltage to the electrically heatable element, which heats the pattern creating member (3, 3 " , 3"). 7. Device according to any of claims 3 - 6, c h a r a c t e r i s e d i n, that a time circuit is arranged to monitor the period of time while the pattern creating member (3, 3 " , 3") is being heated from the point of time when voltage supply commences, and/or that a device is arranged to interrupt said voltage supply when the pattern creating member (3, 3', 3") has penetrated a predetermined distance into footwear placed on the plate member (2). 8. Device according to any of claims 3 - 7, c h a r a c t e r i s e d i n, that the pattern creating member (3, 3 " , 3") comprises a number of individual members, alternatively having a pin-shaped line of extension, or being longitudinally extending members, arranged located separated but adjacently in relation to each other. 9. Device according to any of claims 3 - 8, c h a r a c t e r i s e d i n, that the pattern creating member (3, 3 " , 3") comprises a number of individual members, arranged resiliently movable in relation to each other. 10. Device according to any of claims 3 - 9, c h a r a c t e r i s e d i n, that a layer of granular material, e.g. sand, is arranged by the upper plane of the plate member (2), or that such a layer is available in the immediate neighbourhood of said plate member (2). OMPI

Inventors: GEBELIUS SVEN RUNO VILHELM, GEBELIUS, SVEN, RUNO, VILHELM
Applicants: GEBELIUS SVEN RUNO VILHELM, GEBELIUS, SVEN, RUNO, VILHELM
Application year: 1984
Main classification: A43D95
IPC codes: A43B13, A43D95, B29C35, B29C59, B29D31