EP0077313B1

EP0077313B1 - Flexible slalom pole

Info

Publication number: EP0077313B1
Application number: EP82850199A
Authority: EP
Inventors: Kjell Lindskog; Johan Thorsten Hellzen
Original assignee: Individual
Current assignee: LINDGREN, LARS; LINDSKOG Kjell Jan-Erik
Priority date: 1981-10-13
Filing date: 1982-10-12
Publication date: 1987-03-25
Also published as: DE3275814D1; EP0077313A1

Description

This invention relates to a slalom gate pole of the type including a flexible joint intermediate its ends, permitting the pole to bend from an original position and thereafter return automatically to said original position, and two longitudinally spaced end portions interconnected by the flexible joint, said joint including two longitudinally spaced portions each connected to one of the two end portions of the pole, a longitudinally oriented helical spring sandwiched between said two portions of the joint, retaining means comprising a longitudinally oriented coil spring arranged to urge said two portions of the joint toward one another to longitudinally compress the helical spring, said retaining means further comprising a connecting number extending in the longitudinal direction of said coil spring.
There are known in the art different articles having a flexible joint permitting the article to be bent and subsequently to return to its original position. To exemplify such an article reference is made to DE-C-124 746 which discloses a muscle training appliance with a flexible joint. Said joint comprises two portions each connected to a portion of the muscle training appliance and being held together by an adjustable biassing means acting against at least one of said portions of the joint, and a helical spring located between said portions of the joint and through which a connecting member extends, said spring being exposed to a force of the biassing means at least when the muscle training appliance is bent.
The helical springs used in the known flexible joints of the type described are made of spring wires having a circular cross-section. Such springs have very small contact surfaces between their adjacent spring turns making such springs and, thus, joints including such springs, very instable which is very disadvantageous in connection with slalom gate poles in view of the fact that such poles have to come to a standstill very quickly after being bent and ought not to sway in their original position even if they are subjected to strong wind.
The present invention is designed to overcome the above-noted disadvantages that are attendant upon the construction and use of slalom gate poles having a flexible joint.
This invention is characterized by a provision of a slalom gate pole having a flexible joint of the type described, said joint being provided with a helical spring of a spring wire having rectangular cross-section and said joint being rotatably connected to at least one of the two portions of the joint.
In the following, an embodiment of this invention is described in greater detail and with reference to the accompanying drawing, in which Fig. 1 is a section through a slalom gate pole with a flexible joint according to the invention and Fig. 2 is a section through an alternative clamping means included in the flexible joint.
In Fig. 1, an article 1 is shown in the form of a slalom gate pole comprising a flexible joint 2. The article, i.e. the slalom gate pole 1, comprises at least two portions 1 a and 1 b, between which the joint 2 is located, and which may consist of a plastic material, but any other material, for example rubber, wood or metal, may be used for said portions 1a, 1b. In a slalom gate pole the joint 2 is located closer to the lower end of the pole than to the upper end thereof, as shown in Fig. 1, but the position of the joint, of course, can be varied and must be adapted to the function and purpose of the pole, in which the present joint 2 is comprised as an essential part.
In the embodiment shown in the drawing, the joint proper 2 comprises a joint body 3 in the form of a helical spring of a spring wire 3a with rectangular cross-section, and two opposed mounting sleeves 4a, 4b each located on one side of the joint body 3, against which sleeves the spring 3 abuts with its ends. The mounting sleeves 4a, 4b are formed each with an outer surface 6 constituting a holder for the intended portion 1 a or 1b, and on which the intended portion 1a, 1b can be retained detachably by friction or by connection in another suitable and expedient way.
Through the joint body, i.e. the spring 3, and the mounting sleeves 4, a flexible connecting member 7 extends for holding together the mounting sleeves 4 and spring 3. When not affected, the turns of said spring abut or are adjacent to each other. Said connecting member 7 may be a chain, steel wire, for example piano wire, wire, plastic rod, rubber wire or the like. The connecting member 7 can be enclosed by a hose coil wound tightly, for example, of a spring steel wire or plastic wire, in order when desired to increase the diameter of the connecting member so that no lateral play can occur between the hollow joint body 3 and the connecting member 7.
Instead of, or in combination with such a protection, or a protection of some other kind around the connecting member 7 a number of stacked, relatively short distance sleeves 40 with suitable material thickness can be arranged in the space between the joint body 3 and the connecting member 7 in order to reduce or adapt the size of said space. These distance sleeves 40 have an outer diameter being only slightly smaller than the inner diameter of the joint body in order also to act as a guide for the joint body, i.e. the spring 3, so that its different turns cannot be displaced in lateral direction relative to each other, but are maintained in place even when the spring 3 is bent.
The connecting member 7 is at least at one end formed as or provided with a threaded portion 8, which carries a washer 9 and at least one nut 10. A spring 11 is clamped between said washer 9 and the adjacent mounting sleeve 4a. At its other end portion, the connecting member 7 is formed as or provided with a conic anchoring portion 41, which is located in a corresponding conic seat 42 in a holder 43. Said holder rests against a shoulder 44 formed in the mounting sleeve 4b and is located within the mounting sleeve 4b.
In the embodiment shown in Fig. 2 said other end portion of the connecting member 7 is formed as a threaded portion 45, which extends through the holder 43 and carries the anchoring portion 41 in the form of a nut being conic at one end and having its seat 42 in the holder 43. Said holder 43 is guided at the end of the portion 1b and rests against the end surface of said portion with a peripheral edge surface. The holder 43 can be formed so as with its end surface 47 to rest directly against the end surface 48 of the mounting sleeve. By this embodiment the advantage is gained that the tension of the spring 11 can be adjusted from outside by the nut 41 without having to dismount the slalom gate pole, which, however, is the case at the embodiment shown in Fig. 1.
The spring 11 comprised in the joint 2 cooperates with the connecting member 7 and exercises a force adjustable in size, which tends to compress the spring 3 acting as the joint body, and due to the fact that the connecting member 7 is flexibly and movably attached relative to the pole it is rendered possible to bend said pole in all directions against the action of the spring 11, which during the bending of the pole is stretched additionally and being charged in order together with the spring 3 to return the slalom gate pole 1 to its original position as soon as the force bringing about the bending ceases. During said return movement the kinetic energy is taken up to a certain extent by the spring 11 every time it assumes the position shown in Fig. 1, whereby no appreciable after-vibrations occur but on the other hand a certain damping of the vibrations is obtained.
In order to additionally increase the damping of vibrations when the slalom gate pole returns from its bent position and to effect a delay of said return movement from a bent position, there is provided at least one elastic brake means 49 for co-operating with the inner surface of the slalom gate pole. Each of said means 49 consists of an elastic member, for example of rubber, and is arranged in a movable manner on the connecting member 7 between the washer 9 and a washer 50 abutting the nut 10. Said elastic members are so formed that they have their peripheral surface 51 contacting the inner surface of the slalom gate pole 1 in a greater or less degree. The contact pressure of the members against the inner surface of said pole in the original position, i.e. in the position shown in the Figure, is adjustable by means of the nut 10 in the embodiment shown in Fig. 1, and by means of the nut 41 in the embodiment shown in Fig. 2.
Upon bending of the slalom gate pole, the spring 11 is compressed and increases its spring force, whereby the brake means 49 are compressed additionally, resulting in that the contact pressure of the brake means against the inner surface of the portion 1a increases and gives rise to increased friction between the brake means 49 and the inner surface of the portion 1a, which friction tends to counteract the sliding occurring between the brake means 49 and said inner surface both when the slalom gate pole is bent and it returns from its bent position. In this position the friction forces between the inner surface of the portion 1a a and the brake means 49 are at its greatest in the embodiment shown in Fig. 1, and the brake means bring about a delay of the return of the slalom gate pole from the bent position and at least at the beginning a slower return of said pole to its original position. By this action of the brake means no after-vibrations occur, but the pole assumes its original position almost directly.
The friction forces produced by the brake means 49 depend to some extent on the inner diameter of the pole. By changing this diameter in one way or another along one or more of the sliding paths of the brake means, the arising friction forces can be controlled and adjusted according to demand and desire.

Claims

A slalom gate pole of the type including a flexible joint (3) intermediate its ends, permitting the pole to bend from an original position and thereafter return automatically to said original position; the pole comprising two longitudinally spaced end portions (1a, 1b) inter-connected by said flexible joint; said joint including two longitudinally spaced portions (4a, 4b) each connected to one of said portions of the pole, a longitudinally oriented helical spring (3) sandwiched between said two portions of the joint (4a, 4b), retaining means comprising a longitudinally oriented coil spring (11) arranged to urge said two portions of the joint (4a, 4b) toward one another to longitudinally compress said helical spring (27), said retaining means further comprising a connecting member (7) extending in the longitudinal direction of said coil spring (11), characterized in that the helical spring (3) is of a steel wire having a rectangular cross-section, and that said helical spring (3) is rotatably connected to at least one of the two portions of the joint (4a, 4b).