US1435642A

US1435642A - Mainspring arbor for timepieces

Info

Publication number: US1435642A
Application number: US467390A
Authority: US
Inventors: Ernest H Horn
Original assignee: WATERBURY CLOCK CO
Current assignee: WATERBURY CLOCK CO
Priority date: 1921-05-06
Filing date: 1921-05-06
Publication date: 1922-11-14
Anticipated expiration: 1939-11-14

Description

E. H. HORN.

MAINSPRING ARBOR FOR TIMEPIECES.

APPLICA'HON FILED MAY6,192L

Patsnted Nov. 14, 1922.

Patented Nov. 14, 1922.

UNITED STATES PATENT OFFICE.

ERNEST H. HORN, OF WATERBURY, CONNECTICUT, ASSIGNOR TO WATERBURY CLOCK CO., OF WATERIBURY, CONNECTICUT,

A CORPORATION.

MAINSPRING ARBOR FOR TIMEPIECES.

Application filed May 6,

To all whom it may concern:

Be it known that I, ERNEST H. HORN, a citizen of the United States, residing at WVaterbury, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Mainspring Arbors for Timepieces; and I do hereby declare the following, when taken in connection with the accompanying drawings, and the characters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this application, a'nd'represent in Fig. 1 a perspective View of a main-spring arbor constructed in accordance with my invention.

Fig. 2 a plan view thereof with the inner end of the main-spring shown as applied to the annular notched rib of the arbor-hub.

Fig. 3 a detached plan view of the inner end of the main-spring showing its conpling-slot.

Fig. 4 a view of the arbor in end elevation with the inner end of the main-spring in longitudinal section and shown in the position which the said end assumes when the spring is unwound, at which time the end of the spring engages with the safety-abutment of the arbor.

Fig. 5 a corresponding view showing the spring as wound and its inner end as engaged with the draft-abutment of the arbor.

Fig. 6 a sectional view on the line 66 of re.

1y invention relates to an improved main-spring arbor for time-pieces, the object being to produce, at a low cost for manufacture, a simple and reliable arbor constructed to provide not only an improved integral draft-abutment but also a safetyabutment arranged to prevent the spring from disengaging itself from the arbor when the spring is unwound.

With these ends in view, my invention consists in a main-spring arbor for timepieces characterized by an annular rib transversely notched to produce, at one operation, a draft-abutment engaged by the inner end of the spring when the same is wound and an opposed safety-abutment positioned to be engaged by the extreme inner end of the spring when the same is unwound.

My invention further consists in a main- 1921. Serial No. 467,390.

spring arbor ior timepieces having certain details of construction as will be hereinafter described and pointed out in the claim.

In carrying out my invention, as herein shown, I employ a main-spring arbor 6, having trunnions 7 and 8, a faced-off couplingshoulder 9 and a hub 10 of approved construction. The hub 10, which slightly exceeds the width of the main-spring 11, is formed with a centrally-arranged. integral, annular rib 12, which, by a single milling "operation, is transversely cut through to form a segmental notch 13, the bottom of which coincides in curvature with; the eriphery of the hub. The cutting of the notch 13 results in the production of what, for convenience, I shall call a draft-abutment 14 and a corresponding safety-abut ment 15, these abutments facing each other and being tangential to the periphery of the hub and, therefore, hook-like in their relations to the ends of the coupling-slot 16 in the inner end of the spring 11, in which the said slot, (which is a trifle wider than the width of the rib 12, as shown. in Figure 2,) is placed with regard to the extreme end of the spring, so as to produce a transverse tie-piece 17, narrower than the length of the said notch. WVhen the spring is applied to the arbor, the tie-piece 17 enters the notch 13, as shown in Figures 2, 4t and 5. Then, when the spring is placed under tension, the forward edge 18 of the tie-piece is engaged with the draft-abutment 14, as shown in Figure 5. Now, in the event of an excessive unwinding of the spring, the inner end thereof is driven back in the notch 13, at which time the outer edge 19 of the tiepiece is crowded against the safety-abutment 1.5 and the spring prevented from disengaging itself from the arbor, which 'is, in arbo-rs as ordinarily constructed, a frequent source of annoyance, calling for a considerable expenditure of time on' the part of jewelers and watchmakers doing repairing and cleaning operations.

My improved arbor is easy produce, since the draftand safety-abutments of its annular rib are produced by a single milling operation, which is much cheaper than upsetting the metal to form an integral hook and also much cheaper than to insert a separate pin to form a drafthook, to say nothing of the advantage seand cheap to cured, under my invention by the concurrent production of a safety-abutment, as described.

I claim:

A main-spring arbor for time-pieces the said arbor having a hub formed with a cen-r trally located, integral, annular rib provided with a transverse segmental notch, the end Walls of Which are opposed to each other and respectively constitute draftand safety-abutments and the floor of which conforms in curvature to the curvature of the said hub.

In. testimony whereof, I have signed this specification in the presence of two suh- 15 scribing Witnesses.

ERNEST H. HQRN. Witnesses:

J. R. PUTNAM,

C. H. HALL.