A FERRULE

Abstract: A ferrule for a stick or crutch consists essentially of rubber and includes a support body (2) and a sleeve (3) connecting with said body. The sleeve (3) is grooved or fluted circumferentially with crests and troughs of the grooves extending generally parallel with the sleeve axis. The end-part (31) of the sleeve (3) connecting with the support body (2) increases in diameter in a direction towards the supporting body (2).

Description: A FERRULE The present invention relates to a ferrule of the kind defined in the preamble of Claim 1. A ferrule that is fitted to the end of a walking stick, crutch, or equivalent device which supportively contacts the ground in use will conveniently consist entirely of an essentially springy, elastic material, such as rubber, that functions to generate a high degree of friction between itself and the ground. The ferule includes a support body and a sleeve whose one end connects with the support body, wherewith the sleeve and the body define a recess or cavity into which said end can be inserted. One problem with ferrules of this kind is that it should be possible to fit the ferrules to shaft ends whose respective diameters vary within a relatively wide range. Accordingly, an object of the invention is to provide a ferrule that can be fitted easily to shaft ends which have diameters within a relatively wide range. Another object is to provide a ferrule that can be removed fairly easily from the end of a shaft to which it is fitted. A further object of the invention is to provide a ferrule that can be fitted to non-round ends of such shafts, and also to shaft-ends whose diameter varies along their respective lengths. These objects are achieved with a ferrule constructed in accordance with the invention. The inventive ferrule for supporting sticks, walking sticks, skiing sticks and like devices is defined in the accompany Claim 1. Further embodiments of the inventive ferrule will be apparent from the accompanying dependent claims. In the case of one embodiment of the invention at present preferred the end section of the sleeve that connects with the support body has a diameter which increases towards said body. Moreover, the sleeve is designed with a fluted or grooved wall, where the crests and troughs of the wall configuration extend generally parallel with the sleeve axis. As a result of the orientation of the grooves, the sleeve is relatively rigid flexurally and therewith offers stable connection of the ferrule, and particularly its supporting body, to the end of the shaft, while enabling the sleeve to be readily adapted to shaft ends of varying diameters and shapes. Because the shaft-end portion connecting with the supporting body widens towards said body, no troublesome material stresses will occur in the sleeve wall in the proximity of the supporting body. In other respects, the ferrule, and particularly its supporting body, may have a design similar to the design of the ferrule described and illustrated in Swedish Patent Application No. 9903197-3. The basic concept of the invention can be considered to lie in establishing in the sleeve wall a number of ribs that are disposed in spaced relationship around the periphery of the sleeve and that extend generally in the axial direction of said sleeve, wherewith mutually adjacent ribs are held together by material bridges which spread generally along the length of respective ribs and which are adapted to offer circumferentially a much lower stretch resistance than the ribs. In preferred embodiments of the invention, the material bridges may be generally U-shaped in cross-section so as to enable the legs of the bridges to bend apart while offering relatively low resistance when the diameter of the sleeve shall be widened. The webs of respective bridges may therewith form further ribs. An exemplifying embodiment of the invention will now be described with reference to the accompanying drawing, in which Figure 1 is a side view of an inventive ferrule; Figure to is an end view of the sleeve belonging to the ferrule: Figure 3 is an end view of the supporting body belonging to the ferrule; and Figure 4 shows schematically an axially section view of the ferrule. The ferule 1 includes a support body 2 and a sleeve 3 connected thereto. The part 31 of the sleeve 3 connecting with the support body 2 has an internal diameter that increases in a direction towards the body 2.1t will be seen from Figure 2 that the wall of the sleeve 3 includes generally axially extending recesses 31 and 32 on the inner wall and the outer wall respectively of the sleeve. The recesses 31, 32 alternate in the peripheral direction of the sleeve such as to impart an grooved or fluted configuration to the sleeve 3, as viewed from Figure 2. It can be said in this regard that the sleeve 3 comprises a number of mutually parallel ribs 40 disposed in mutually spaced relationship around the perimeter, or circumference, of the sleeve 3, said ribs extending generally in the axial direction of the sleeve. The ribs are mutually connected by generally U-shaped material bridges 41, as seen from the Figure 2 illustration. At least the sleeve 3 consists of an elastomeric material, such as rubber, and in a relaxed or non-loaded state has the configuration shown in Figure 2. When fitting the ferrule 1 to a shaft-end that has a larger diameter than the free inner diameter of the relaxed sleeve 3, the material bridges 41 will bend in response to the application of a relatively small force, so as to allow the sleeve 3 of the ferrule to receive shaft ends whose respective diameters vary over a relatively wide range. The generally U-shaped bridges 41 can be considered to include a web and web- connecting legs which at their opposite end are integral with the ribs 40. The webs of respective bridges can also be considered as constituting ribs. In one variant of the illustrated embodiment, the bridges 41 are formed of relatively thin material which can be stretched so as to enlarge the diameter of the sleeve 3. However, the sleeve 3 will preferably have a fluted or grooved configuration that permits widening of the sleeve diameter by bending out the bridges 41. As will be seen from Figures 1 and 4, the sleeve 3 has a generally constant diameter along its length, up to the part 31 where the inner diameter of the sleeve 3 is widened in a direction towards the support body 2. The inner surface of the support body is preferably provided with a metal washer or plate 22. The increase in the diameter of the wall 3 towards the support body 2 conforms to range of diameters which allows the ends of shafts to be received without the occurrence of hazardous forces in the connection between the wall 3 and the supporting body 2. It will be seen from Figure 2 that the flutes or grooves 32 also extend along the diameter- widened part of the sleeve 3, up to the support body 2. The inner grooves or flutes 31 extend correspondingly, preferably also up to the body 2 in the proximity of the support washer or plate 22. It will be seen from Figure 3 that the side of the support body 2 proximal to the ground in use is convex in shape and has disposed around the ferrule axis a plurality of U-shaped support surfaces which seen peripherally have pair-wise a total width that increases with distance from the ferrule axis.

Claims: CLAIMS 1 A ferrule for that end of the shaft of a supporting stick, crutch or like device that supports against the ground, wherein the ferrule is comprised essentially of a springy resilient material, such as rubber, that will generate a high degree of friction in contact with the ground, and wherein the ferrule includes a supportive body (2) and a sleeve (3) which connects with said body and into which said end of the shaft can be inserted such as support against said body, characterized in that the wall of the sleeve (3) is comprised essentially of a plurality of elongate ribs (40) which are disposed in mutually spaced relationship around the periphery of said sleeve (3) and extend generally in the axial direction of the sleeve (3); and in that mutually adjacent ribs (40) are held together by material bridges (41) which spread generally along the length of the ribs (40) and which are adapted to offer substantially less stretch resistance than the ribs (40) in a circumferential direction. 2 A ferrule according to Claim 1 , characterized in that the bridges are U-shaped and adapted to bend significantly in a plane normal to the sleeve in response to a change in the free internal diameter of the sleeve. 3 A ferrule according to Claim 1 or Claim 2, characterized in that the sleeve has a generally constant wall thickness along its length and in that the sleeve has an end section which connects with the supportive body (2) and which has a diameter that increases towards the supportive body (2). 4 A feπule according to Claims 1 - 3, characterized in that the bridges are generally U- shaped as seen in a plane normal to the sleeve axis. 5 A ferrule according to Claim 4, characterized in that the bridges (41) and the ribs (40) are defined by generally axially extending recesses in the inner and the outer surfaces of the sleeve (3). A ferrule according to any one of Claims 1 - 5, characterized by a support washer or plate (22) which is positioned on the inside of the supporting body (2) and which functions to distribute the load from said shaft-end to said support body. A ferrule according to any one of the preceding Claims, characterized in that the wall of the sleeve (3) is grooved circumferentially, wherem the crests and troughs of the grooves extend parallel with the sleeve axis.

Inventors: SKEPPSTEDT STAFFAN, SKEPPSTEDT, STAFFAN
Applicants: PERSON OCH ORGANISATIONSPOETIK, SKEPPSTEDT STAFFAN, PERSON- OCH ORGANISATIONSPOETIK, SKEPPSTEDT, STAFFAN
Application year: 2001
Main classification: A45B9
IPC codes: A45B9, A61H3