Joints and connections – Articulated members – Lockable at fixed position
Reexamination Certificate
1999-11-17
2001-06-26
Canfield, Robert (Department: 3635)
Joints and connections
Articulated members
Lockable at fixed position
C403S104000, C403S109100, C135S075000, C280S823000
Reexamination Certificate
active
06250839
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a length-adjustable tube, in particular for ski poles or walking sticks, with at least one outer tube and an inner tube, which can be inserted in a telescope-like manner into the outer tube for adjusting the tube length. Also included is an expansion device which has an expansion element. The expansion element can be approximately radially spread apart and by means of which the inner tube can be axially clamped in plane in the outer tube.
BACKGROUND OF THE INVENTION
Since the expansion element used with the expansion device is generally made of a relatively hard plastic material, a problem arises, in that for clamping the expansion device it is necessary to fix the respective expansion element in place on its circumference in the outer tube already at the start of the expanding movement. This is not easily assured in view of the diametric tolerances of the outer tube and the inner tube of a length-adjustable tube.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a length-adjustable tube of the type mentioned at the outset, wherein gripping of the expansion device inside of the outer tube is assured in every case.
The expansion element of the expansion device is provided with at least one flexible friction element in the area which can be approximately radially spread apart, for the purpose of compensating diameter tolerances between the inner tube and the outer tube, and extends past its exterior circumference.
It has been achieved by means of the measures of the present invention that, independently of the diametric tolerances between the outer tube and the inner tube, the flexible friction element(s) grip(s) in every case, and it is also prevented that the expansion element, which is made of a relatively hard plastic material, possibly might not fit into the outer tube.
In the axial extension of the expansion element the friction element is provided with a crowned outer contour which is at least flush at both ends with the outer circumference of the expansion element area. This assures an always problem-free insertion of the expansion element into the outer tube. Possible other damage of the expansion element in case of too small diameter differences between the inner and outer tubes are also prevented by means of this.
A preferred embodiment of an expansion device for a length-adjustable tube results from the friction element being constituted by a slit ring, which is axially fixed in place in an annular groove of the expansion element. This embodiment has the advantage that, following the production of the expansion element, the slit ring can be applied in a simple manner on it by being elastically widened. It is useful here to embody the slit ring to be in two layers, wherein the inner layer is made of relatively hard plastic material, and the outer of a flexible plastic material so that a resiliently elastic application and holding of the slit ring on the expansion element is possible.
Further embodiments of the friction element(s) on the expansion element are characterized in that the expansion element is provided with molding in which the flexible friction elements are provided as inserts, which have been preferably evenly distributed over the circumference, or the flexible friction elements are designed to be elongated in the axial direction, on the flexible friction elements are designed as dots, or that the inserts have been extruded into the moldings.
REFERENCES:
patent: 2275330 (1942-03-01), Tveten
patent: 2456205 (1948-12-01), Magder
patent: 2494878 (1950-01-01), Jensen
patent: 2533733 (1950-12-01), Jensen
patent: 2542967 (1951-02-01), Waechter
patent: 4134703 (1979-01-01), Hinners
patent: 4238164 (1980-12-01), Mazzolla
patent: 4324502 (1982-04-01), Pickles
patent: 5460458 (1995-10-01), Caceres
patent: 5769104 (1998-06-01), Uenura
patent: 5786147 (1999-03-01), Longo
patent: 5803643 (1998-09-01), Patelli et al.
patent: 5897268 (1999-04-01), Deville
patent: 5908214 (1999-06-01), Dinardo
patent: 6045288 (2000-04-01), Pasternak et al.
patent: 267 177 (1950-06-01), None
patent: 1 058 889 (1959-06-01), None
patent: 9319933 (1994-04-01), None
patent: 19509081C1 (1996-06-01), None
Canfield Robert
Jones Tullar & Cooper P.C.
LandOfFree
Length-adjustable tube, specially for ski poles or walking... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Length-adjustable tube, specially for ski poles or walking..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Length-adjustable tube, specially for ski poles or walking... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2536712