Land vehicles – Ski or skate appliance or attachment – Ski pole
Reexamination Certificate
1998-09-25
2001-07-03
Johnson, Brian L. (Department: 3618)
Land vehicles
Ski or skate appliance or attachment
Ski pole
C280S821000, C135S082000
Reexamination Certificate
active
06254134
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a shock absorbing device for rods or poles being used for skiing, for excursions, for walking, for crutches and similar articles.
BACKGROUND OF THE PRIOR ART
It is known that the practice of skiing both when one goes downhill as well as at the bottom, requires the use of poles in a variety of situations with variable intensity and frequency above all as a function of the particular type of activity being carried out. In particular, during skiing when one goes downhill the poles are used as assistance elements during the phases of the departure and thrust in maintaining the equilibrium and in applying the trajectory, and also when one goes uphill.
On the contrary, in sking at the bottom and also during the practice of walking in ski boots, the poles are used to complete the motion of the legs following typically the cadence in a synchronous manner. Both these situations involve stresses of different nature and intensity which are transmitted to the limbs which maneuver the poles. Specifically in sking when one goes downhill these stresses are typically short, of great intensity and relatively sporadic and irregular. On the contrary, in skiing at the bottom, the stresses result more prolonged and of lower intensity but with high frequency of repetition typically equal to the forward steps. In every case for activities which are carried out with substantial intensity and/or extension of the period of time and in a particular manner for professional athletes, these stresses are capable of favoring or determining pathological conditions of the articulations of the upper limbs, in particular the wrists and the elbows. For the purpose of obviating these drawbacks there have been already adopted for some time shock absorbing devices above all on the poles which are used for the practice of skiing on a road (ski roller) and on the poles being used for pedestrian excursions. These known devices consist essentially of a simple spiral spring which is placed internally and coaxially with the pole. These devices may be placed at the level of the handgrips, or the tips, but also in any other intermediate position of the pole.
In actual practice these devices have given unsatisfactory results and in some instances have produced the opposite result during use. The absence of damping in fact brings about a constant tension of muscles and tendonitis of the limbs in elastic bearing and favor the occurrence of troubles such, for instance in the tendonitis In addition, these devices are capable of increasing the total weight of the pole and also increase the final cost for the user. These devices have been partially eliminated with a shock absorbing device for poles and similar articles described in Italian patent application, No. VI95A000131, dated Aug. 3, 1995, filed in the name of the applicant as in the present application. This device provides similarly to the devices of known type the presence of two cylinders coaxial with the longitudinal axis of the structure to be dampened, one of the two cylinders being placed partially within the other, with the possibility of sliding with respect to the same in the presence of stresses which occur on the structure during use following the contact with the bearing surface and is characterized mainly by the fact that it utilizes an elastomer as the elastic means.
Both the device described hereinabove as well as other devices which have been proposed for the same purpose operate with a damping action only in one direction of motion, generally from the position of rest in the direction of compression so that the result is they are substantially rigid in the opposite direction. Consequently the return of the rest position of the elastic element following the removal of the load causes a dry recoil which for instance amounts to a nuisance also because of the noise being generated over prolonged use.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a shocking absorbing device for poles and similar articles which is free of the drawbacks described hereinabove and which in particular is effective in a dampening action in both the two phases, that is the phase of compression followed by the phase of traction. In particular with the device of the present invention in addition to achieving a shock absorbing action of the impact of the pole with the ground in a manner to generate a feeling of comfort in the limb which performs the maneuver the following results are possible:
the axial motion is adequately dampened;
the relation between both the compression force or positive force and the traction force or negative force and the deformation does not result linear with substantial initial yielding and a progressive stiffening;
transmission of the maximal pair required by the internal blocking mechanism which has an expansion screw and which is ordinarily adopted in the telescopic poles for the purpose of joining reciprocally the parts which constitute the pole and/or the pole with the handgrip;
the device which is contained in the interior of the pole or in one of the portions of the pole requires a minimal axial space, has substantially reduced weight and allows to assemble rapidly the various components with economical results.
The following results are achieved according to a first embodiment of the invention by providing that in the known constructive solution described hereinabove, that is the constructive solution composed of two cylinders which are coaxial and which slide reciprocally, the intermediate elastic element results firmly anchored with its two opposite bases to the corresponding surfaces of the bearing of the two above bodies.
As it is easily understandable with this constructive device the shock absorbing action occurs in addition to obviously during the compression phase of the elastic element also during the subsequent expansion phase, that is the traction phase due to the internal elastic return which the same structure being expanded carries out.
For the purpose of preventing that the return course, that is the expansion course turn out to be excessive and causing the yielding of the elastic element or the separation from the bearing bases, there is provided the action of a structure which carries out a rigid end course which intervenes after a certain predetermined traction course. This end course structure is advantageously applied to the extremity of a floating shaft, the latter being integral with one of the two coaxial cylindrical bodies which slide reciprocally one with the other.
According to another embodiment of the invention for the purpose of generating a shock absorbing action both during the compression as well as during the traction phase, there is provided the use always in the interior of the coaxial cylindrical bodies which slide reciprocally one with respect to the other, of two elastic means which operate on the two faces of the common bearing face of the cylinder which is placed internally.
With this second constructive solution the shock absorbing action is further reinforced by providing that at least one of the two elastic means which are placed one opposite to the other has a dimension such that it may slide against the containing wall so that during the compression phase it operates as a typical friction piston.
A good shock absorbing device which offers constant elastic elements and suitably not linear, in addition to the use of an elastomer is achieved by using conical or bi-conical metallic springs.
The maximal compactedness and light weight of the shock absorbing device is achieved by using a single elastic element which operates both during the traction and during the compression phase and which is provided with a lock for stopping the shaft, the shaft being obtained with an elastomer of a foamed polyurethane of the type for instance commercially known under the names of CELLESTO or POLYCEL or with metallic springs of the type “bovolo” which means a twisting spring with conical helix and rectangular section or particular conical spring
Avery Bridget
Bucknam and Archer
Gabel srl
Johnson Brian L.
LandOfFree
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