Telescopic element, particularly for frames of folding bicycles

Abstract: A telescopic element, particularly for frames of folding bicycles, comprising a sliding inner element (302) that can be locked in an operating position within an outer element (301) by a quick locking element (307), the locking element comprising a ring that is normally in the position for locking the axial movement of the inner element (302) with respect to the outer element (301), the locking element (307) being movable radially by means of a release button (310).

Description: The present invention relates to a telescopic element, particularly for frames of folding bicycles. The need has been felt for a telescopic element that can be quickly locked and released from the normal operating position but at the same time is also extremely resistant to the stresses to which it is subjected, for example when it is included in the frame of a bicycle or the like. GB-A-1 435 312 discloses all of the features of the preamble of claim 1. A principal aim of the present invention is to provide an extendable element provided with a quick and safe locking means. Within the scope of this aim, an object of the present invention is to provide a telescopic element that is compact especially in the region provided with the locking means. Another object is to provide a telescopic element that does not have troublesome and dangerous protrusions, especially with respect to its use as an element of a bicycle frame. This aim, these objects, and others which will become apparent hereinafter are achieved by a telescopic element, particularly for frames of folding bicycles, as defined in claim 1. Further characteristics and advantages of the invention will become apparent from the following detailed description of a preferred but not exclusive embodiment thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein: figure 1 is a lateral elevation view of a folding bicycle in the operating position, provided with the telescopic element according to the invention; figure 2 is a view, similar to the preceding one, but in an almost-folded position; figure 3 is a longitudinal sectional view of the telescopic element according to the invention in closed position; figure 4 is an enlarged-scale partial longitudinal sectional view of the locking means of the telescopic element in the locking position; figure 5 is a view, similar to the preceding one, in the released position; figure 6 is a sectional view, taken along the plane VI-VI of figure 4. With reference to the above figures, a folding bicycle, generally designated by the reference numeral 1, comprises a frame constituted by a lower member 2 that rotatably supports a rear wheel 3 at its rear end. The pedal crank shaft 4 is rotatably supported in a median position. A saddle post 11 is pivoted to the lower member 2 at the pedal crank shaft coupling axis, and a handlebar post 12 is pivoted at the front end of the member 2. The posts 11 and 12 are substantially parallel to each other and are joined by an upper member 13 pivoted to the end of the posts 11 and 12. The handlebar post 12 constitutes a supporting element for a head tube 20 that is articulated to the raised portions 21 and 22 formed at the ends of the post 12. The telescopic element 30 is provided in order to lock the frame in the desired position and can be arranged at a diagonal of the articulated parallelogram. As shown in figure 2, the bicycle is folded very easily; after releasing the telescopic element 30, folding occurs, in practice, by turning the saddle post towards the rear wheel. The telescopic element 30 is constituted by an outer element 301 that telescopically couples to an inner element 302 through a locking means 303. The inner element has a tip 304 provided with a tapered guiding portion 305 and an annular groove 306 adapted to be engaged by a locking ring 307 associated with the locking means 303. The locking ring 307 is accommodated in an appropriate annular seat 308 formed in a wider region 309 of the end of the outer element 301. The locking element 307 has a button 310 that acts in contrast with a flat spring 311 which is fixed by means of a screw 312 in a position lying diametrically opposite to the button 310. The spring 311 tends to keep the locking ring 307 normally engaged with the annular groove 306 of the tip 304, so as to keep said tip 304 locked at the wider portion 309, as shown in figure 4. The wider portion 309 furthermore has a stroke limiting element 313 for the tip 304 in the locking position, shown in figure 4. Figures 3 and 4 are views of the telescopic element 30 in the closed position that corresponds to the operating position of the bicycle, shown in figure 1. If one wishes to fold the bicycle and must therefore extend the telescopic element 30, it is sufficient to press the button 310 to move the ring 307 radially, in contrast with the spring 311, as shown in figure 5, thus releasing the annular groove 306 so as to allow the tip 304 to extend outwardly. In order to return the bicycle to the operating position, it is not necessary to act on the button 310 again, since the tapered portion 305 of the tip 304 forces the ring 307 to move radially when the tip 304 is inserted in the wider portion 309. In practice it has been observed that the invention achieves the intended aim and objects, a quick and safe locking/release system for a telescopic element having been provided. Another advantage of the invention resides in the fact that there are no awkward protruding elements that are furthermore dangerous in a bicycle frame. The telescopic element according to the invention is susceptible of numerous modifications and variations, all of which are within the scope of the invention. Of course, the materials employed, as well as the dimensions, may be any according to the requirements and the state of the art. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims: A telescopic element, particularly for frames of folding bicycles, comprising a sliding inner element (302) that can be locked in an operating position within an outer element (301) by a quick locking means (303), said locking means comprising a locking element (307) that is normally in the position for locking the axial movement of said inner element with respect to said outer element, characterized in that said locking element comprises a rigid locking ring (307), said locking ring being radially movable in an annular seat (308) formed in one of said inner or outer elements, for the release of said inner element (302). The telescopic element according to claim 1, characterized in that said locking ring (307) is arranged at the ends of said inner (302) and outer (301) elements. The telescopic element according to claim 1, characterized in that said locking ring (307) engages an annular groove (306) formed in the other one of said inner (302) or outer (301) elements. The telescopic element according to claim 3, characterized in that it comprises a button (310) to actuate the radial movement of said locking ring (307), said button being actuatable from the outside against an elastic element (311). The telescopic element according to claim 4, characterized in that said elastic element (311) is constituted by a flat spring associated with said annular groove (306). The telescopic element according to claim 3, characterized in that said annular seat (308) is formed inside a wider portion (309) of said outer element (301), said annular groove (306) being formed on the outside of the end of said inner element (302). The telescopic element according to claim 3, characterized in that said inner element (302) comprises a tip (304) provided with a tapered guiding portion that is adapted to enter at said locking ring (307) to move said locking ring radially in order to lock said inner element within said outer element (301).

Inventors: FERRARIN FRANCIS, FERRARIN, FRANCIS
Applicants: IDIT INTERNAT DESIGN N V, IDIT, INTERNATIONAL DESIGN N.V.
Application year: 1996
Main classification: B62K15
IPC codes: B62K15, F16B7