Horology: time measuring systems or devices – Cases – With protection means
Reexamination Certificate
1998-06-05
2001-03-13
Miska, Vit (Department: 2859)
Horology: time measuring systems or devices
Cases
With protection means
C368S319000
Reexamination Certificate
active
06200020
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an operating means with a seal, for a timepiece, according to the introductory part of claim
1
. For sealing operating organs of a timepiece usually O-rings are applied. Since these do not always seal the inside of the timepiece to a satisfactory degree, already for some time there has been undertaken a variety of efforts to develop seals with improved sealing properties, in that the cross sectional shape of the O-rings has been dropped.
From CH 562 468 a dust-tight crown for timepiecees is known, which comprises an elastically deformable sealing packing with an S-shaped bent cross sectional shape. Although this sealing packing in comparison to O-rings on the side of the inner space is formed out differently than on the side which faces the surroundings, this packing acts roughly equally in both directions, i.e. that on excess pressure in the timepiece inner space it has a similar sealing behaviour as with a excess pressure in the surroundings.
On the one hand a packing of such a shaping ensures that a formation of a considerable excess pressure in the inside of the timepiece cannot occur since it comprises a tapering packing part which in such a situation comes away from the wall of the bore.
If however the pressure of the surroundings of a timepiece equipped with such a crown increases, for example on diving, then this packing likewise only puts up a small resistance to the penetration of matter into the inside of the timepiece on account of the shaping of the mentioned packing part.
Furthermore this solution has the disadvantage that on placing back the winding axis, from the hand setting position into the basic position, particles of dirt from the tapering packing part may be co-transported into the inside of the timepiece. By way of the contamination of the sealing region the danger of penetration of water is also considerably larger.
Furthermore such a crown requires an exact length setting and assembly of the winding-up shaft.
With CH 453 221 there is shown an operating organ with an L-shaped seal which comprises a conical sealing surface which is in contact with the outer walling of a sleeve arranged in the timepiece housing. This sleeve is formed conically so that the placing of the crown onto the sleeve can be carried out simply. In the placed-on condition the sealing is deformed so far that the conical sealing surface blends into a cylindrical one and accordingly bears on the sleeve over the whole circumference with a close fit, and with a relatively large pretensioning. For the purpose of an additional increasing of the bearing force the sealing is designed in a manner such that it broadens towards the inside in the direction to the axis.
As a rule the solution implies a differing sealing behaviour in both directions, however it has the effect that it only prevents penetration of matter into the inside of the timepiece in a limited manner and that a rapid reduction of excess pressure in the timepiece is not possible.
According to CH 324 259 between a bore in the crown and the outer walling of the sleeve there is arranged a sealing ring with a V-shaped cross section in whose wedge-shaped annular groove there is arranged a metal ring which is axially impinged by a spring. By way of the spring pressure the two arms of the V-shaped sealing ring are radially expanded in order to produce a bearing force on the one hand with respect to the sleeve and on the other hand to the bore of the crown.
Also with this solution there may arise a considerable excess pressure on the inside of the timepiece.
Furthermore CH 304 789 shows sealing disks which in each case bear on an annulus-shaped surface in a deformed manner and under pretension.
Although with this solution a reduction in excess pressure in the timepiece is possible, narrow limits are set to the axial path of the winding-up shaft.
Moreover also an exact length setting of the winding-up shaft is required.
BRIEF SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an operating means which
given surrounding excess pressure excellently seals,
given surrounding negative pressure permits a rapid pressure compensation,
does not require an exact length setting and assembly of the shaft,
permits a sufficiently large movement path of the shaft,
as well as keeping away dirt particles from the sealing region and from the inside of the timepiece.
The solution according to the invention is to be deduced from the features of claim
1
.
By way of the fact that the operating means according to the invention is provided with a lip seal which is orientated such that the concentric skirting-shaped lip faces from the inner space of the timepiece to the surroundings, the lip with an increasing excess pressure of the surroundings is pressed more heavily on the cylinder jacket shaped surface region, from which there arises an excellent sealing.
In reverse, with a negative pressure the lip is advantageously so deformed in the timepiece that it is pressed away from the cylinder jacket shaped surface region and forms a passage for a rapid reduction of pressure.
The lip sealing thus acts without additional displaceable elements as an automatically actuating valve.
Furthermore a lip sealing in the suggested alignment has the advantage that it acts as a dirt stripper and thus prevents access of dirt particles to the sealing region as well as to the inside of the timepiece. By way of this the sealing region remains constantly clean and the danger of entry of water is considerably reduced. For example and additionally provided O-ring likewise remains clean in this manner and its quality of sealing, in particular with respect to water, remains.
Sealing region is to be understood as contact surfaces of the seal as well as of the parts of the operating means in contact with this or with the timepiece, i.e. surface regions of the seal as well as surface regions of for example the outer or inner wallings of the sleeve, of the cover of the timepiece housing etc., according to the embodiment form of the operating means according to the invention.
In contrast to an O-ring, with the lip seal there is still a further advantage of great importance: O-rings on account of their manufacture comprise a circular seam which is located at the location of the largest circumferential line. With seals of small dimensions, this seam, as is the case in the field of timepiecees, is characterized by prominent irregularities of the surface, which considerably compromise their sealing qualities. With a lip seal on the other hand at the sealing locations, i.e. in those regions which are in contact with the walling of the bore there are no seams present. Also this contributes considerably to the improvement of the tightness.
The operating means according to the invention further comprises the advantage that by way of the application of a lip seal no exact length setting and assembly of a possibly provided shaft is required and without problem a larger path of this shaft may be provided for. With this it may be the case of a hand-setting or winding-up shaft or likewise.
According to a further advantageous formation according to the invention a screwed crown comprises a further O-ring which is compressed on screwing on the cover, this resulting in the advantage of a further sealing security in the case of an increase in external pressure as occurs for example on diving. The sealing properties of the lip seal of the operating means according to the invention are however superb in the manner that on diving there neither enters any water when the cover is not screwed down.
The operating means according to the invention may for example be a screwed or non-screwed crown, a pushpiece, a correcter, a switch or likewise.
REFERENCES:
patent: 2773347 (1956-12-01), Froidevaux
patent: 3130539 (1964-04-01), Davis
patent: 3164954 (1965-01-01), Soguel
patent: 3376701 (1968-04-01), Grohoski et al.
patent: 3475901 (1969-11-01), Soguel
patent: 3485036 (1969-12-01), Feurer
patent: 237996 (1945-09-01), No
Griffin & Szipl, P.C.
Meco SA Grenchen
Miska Vit
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