US2188688A - Watch crown seal - Google Patents

Description

Jan. 30, 1940. e. MACK WATCH CROWN SEAL Filed D90. 1, 1937 2 Sheets-Sheet l [Ml e17 to" ea/7e fo/waml yac Jan. 30, 1940.

G. E MACK 2,188,688

WATCH CROWN SEAL Filed Dec. 1, 1937 2 Sheets-Sheet 2 Patented Jan. 30, 1940 eerie WATCH CROWN SEAL George Edward Mack, Truro, Nova Scctia, Canada Application December 1, 1937, Serial No. 177,436

3 Claims.

The principal objects of this invention are to provide an extremely simple and inexpensive means for sealing the stem or winding arbor orifice in watches against the entry of dust or water and. which will automatically adjust itself to compensate for wear, thereby protecting the movement from erosive and corrosive elements.

A furtherand important object is to protect the crown stem from accidental distortion or breakage and to provide a smooth winding action.

The principal feature of the invention consists in the provision of angular contact bearing surfaces on the watch case or pendant and on the crown and maintaining such surfaces in constant pressure bearing contact thereby providing an effective seal against the ingress of water or dirt.

A further and important feature resides in the novel formation of a sealing seat in the watch case of the separable section type with respective portions of the seat formed in respective sections or the case and adapted to mate about the crown stem to iormfa peripheral sealing seat when the sections are closed together.

In the accompanying drawings Figure 1 is an enlargedplan View of a watch having part of the bezel and cover removed and disclosing a portion of the winding and setting mechanism to which my invention is applied.

Figure 2 is an enlarged part sectional elevational view of a portion of the structure illustrated in Figure 1 showing the crown in its sealing position.

Figure 3 is a plan view of the mechanism illustrated inFigure 1 showing the position of the parts when the crown and stem are moved outwardly in the setting operation.

Figure 4 is a view similar to Figure 1 of a modified form, of the invention.

Figure 5 is a side elevational view of the sectional casing on a reduced scale showing the mating portions of the sealing seat formed in the respective portions of the separable casing.

In the manufacture of watches it has been customary to form the case or pendant with a circular orifice through which the crown stem extends, usually in a close turning fit, and in some cases the crown or pendant or both have been formed with bafiie flanges, of more or less complicated and necessarily fragile construction, in an attempt to prevent the ingress of dust but as far as I am aware none of these have accomplished the desired result of eifectively sealing the stem orifice against the ingress of dust or Water.

The watch mechanism herein shown is that of a well known. type in which a double springactuated clutch mechanism is mounted on. the crown stem.

The stem 5 is formed with a squared portion upon which the inner clutch or castle wheel 2 is sliclahiy and non-rotatably mounted, the outer ratchet face 3 of which engages the winding clutch and the inner ratchet face of which is adapted to engage the setting gear 5.

An annulariy grooved collar 5 is secured upon the stem 5 and the set lever l, which is pivotally mounted on a pin 8 on the movemen frame is provided with a pin 5 at one end which extends into the groove of the said collar so that when the stem is pulled outwardly for setting the movement the lever l is rocked on the pin 8.

The lever '3 is formed with a cam latch H! which operatively engages the shipper I! which is piv- Cit otall'y mounted on the screw 12 and operatively I engages in the annular groove l3 of the clutch 2 to move same longitudinally on the stem l to connect the stem with either the winding or setting clutch.

The shipper spring M is here shown as part of the plate it? and is provided with a notched end it which engages a pin ll on the outer end of the set lever l and exerts a constant spring pressure on the set lever and through the pin 9 and collar 6 exerts a constant inward spring pressure thrust upon the stem I when in the or- 3? dinary or winding position. The notched end of the spring 64 is adapted to mount the pin I! on the outer end of the set lever when the stem is pulled outwardly for setting and temporarily holds the stem in its outward position.

In the structure as illustrated in Figure 4 the shipper arm H pivotally mounted on the screw I2 is engaged by the cam end H) of the set lever I which is pivoted on the fixed pin 8'. The inner end. of the set lever l engages the annular groove in the collar 3 which is fixed on the stem I so that when the crown 25] is pulled outwardly, this bell crank lever i shifts the shipper arm II to the setting position.

The-lever l is provided with a pin 11 which is engaged by the bevelled surface l'l of the notched end of the shipper spring l4 and maintains a constant inward thrust on the spindle I so that the bevelled face of the crown is maintained in constant pressure contact with the tapered seat in the watch case.

The form of winding and setting mechanism varies considerably in difierent makes of watches but all watches have a structure the equivalent of that described, in that the shipper spring exerts a constant inward pressure on" the stem holding the winding mechanism in gear therewith.

It is important to note that according to the invention herein contained, the bevel portion of the crown is so placed that its engagement with the seat takes place well prior to the return of the stem, shipper spring and set lever to what would otherwise be their normal winding position, so that the full co-operation of the shipper spring is obtained in its urge to return to normal or neutral position, thereby definitely ensuring that the bevelled stem and case surfaces will be maintained in full pressure-sealing contact and providing at the same time compensation for wear of such surfaces.

As herein shown the case l8, or a pendant when used, is provided with a circular orifice [9 which is bevelled inwardly and presents an angled seat.

The crown 2B, which is suitably secured on the outer end of the stem l is formed with a tapered portion 2|, having the same angle of bevel as the seat l9, which is adapted, on the inward movement of the stem, to engage the seat l9 and as the shipper spring exerts a constant inward pressure on the stem the tapered surface of the crown is held in spring pressed contact with the tapered seat i9 and forms a dust and water-tight seal. These closely engaging and concentric surfaces form an accurate bearing for the spindle so that it will always turn smoothly.

It will also be readily appreciated that the constantly engaging taper of the crown with the taper seat will support the spindle and prevent distortion of the stem in the event of the crown being struck with. any lateral force. Further it will be understood that any wear occurring between the tapered surfaces will be automatically taken up by the spring-actuated movement of the stem.

The extreme simplicity of the device will be readily apparent and the invention can be readily applied to any design of watch.

Another feature of importance is that the taper fit of the crown and seat not only supports the stem but acts as an anchor to hold the movement from shifting in the case.

What I claim as my invention is:

1. In a watch having a bevelled stem orifice in the case, the combination with the shipper spring and co-operating set lever and stem, said parts having a normal neutral relation with the stem in normal winding position, of a crown mounted on said stem having a bevelled surface positioned to sealingly engage the bevelled-stem orifice, all of said parts being so constructed and arranged as to effect said sealing engagement at a point intermediate of the inward travel of the stem to normal winding position to prevent the full return of said shipper spring and co-operating parts to their normal position, whereby the urge of the shipper spring to assume normal position is utilized to maintain definite pressure-sealing engagement between the respective bevelled surfaces and compensate for wear therebetween.

2. In a watch having a case formed in separable sections, a crown stem having a conically surfaced portion, and spring'means for urging said crown s'tem to normal winding position, a conically surfaced seat composed of mating portions formed respectively in the'separable sections of the case and so co-operatively related to the aforesaid parts as to effect sealing engagement with said comically surfaced stem portion at such point in the return movement of the stem as to prevent its spring-urged displacement to normal winding position.

3. Means as claimed in claim 2 in which said separable casing sections are of the type. having overlapping portions with the conical seat portion of one case section underlying the conical seat portion of the other case section in an effective dust-excluding stepped joint.

GEORGE EDWARD MACK.

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