US3015933A

US3015933A - Electric timepiece contact mechanism

Info

Publication number: US3015933A
Application number: US755198A
Authority: US
Inventors: Koehler Fred
Original assignee: Hamilton Watch Co
Current assignee: Hamilton Watch Co
Priority date: 1958-08-15
Filing date: 1958-08-15
Publication date: 1962-01-09
Anticipated expiration: 1979-01-09

Description

Jan. 9, 1962 F. KOEHLER 3,015,933

ELECTRIC TIMEPIECE CONTACT MECHANISM Filed Aug. 15, 1958 INVENTOR Fred Koeh/er ATTORNEY United States Patent 5 lvania y Filed Aug. 15, 1958, Ser. No. 755,198

6 Claims. (CI. 58-28) This invention relate to an electric timepiece and more particularly relates to an improved adjustable mounting for the spring contact in a battery operated electric timeiece.

p In a battery operated electric timepiece of the type shown in assignees Patent No. 2,662,366 to Fred Koehler, a magnetic bar is carried by the balance staff and is periodically impulsed by the pole pieces of a pair of electro-magnets. The periodic impulses are created by cyclically connecting the electro-magnets to the battery and this periodic connection is accomplished by a sprmg contact mechanism.

In the type watch shownin the aforementioned Koehler patent, this contact mechanism consists of an elongated contact spring which is fixedly mounted at one end and which carries a movable contact at its other end. A 'camrning means is attached to an intermediate portion of the spring and periodically forces the free end carrying the contacts into engagement with stationary contacts. The elongated spring extends past the index wheel of the timepiece and the camming means on the spring engages the teeth of the index wheel so as to cause the desired movement of the contact-carrying end of the spring as the index wheel is rotated under control of the balance staff and its associated parts.

The tension with which the contact spring cam presses against the teeth of the index wheel is somewhat critical in that this tension serves the dual purpose of holding the index wheel in position between impulses from the balance staff and also breaking the electric contact. If the tension of the spring is too low, it can cause the contact to stick and can also cause the sweep second hand of the timepiece to run away when the hands of the timepiece are set to time. Too high a tension requires excessive energy to move the index wheel and results in a low motion of the balance wheel.

In the Koehler type timepiece shown in the aforementioned patent, the adjustment of the tension in the contact spring is initially made at the factory and is: not readily changed except by returning the timepiece to the factory. In those instances where it is necessary for jewelers to upset the tension, it is difiicult to reset it to the proper value without returning the timepiece to the factory.

It is accordingly a primary object of the present invention to provide an improved battery operated timepiece of the type generally shown in the aforementioned Koehler patent having an improved mounting of the contact mechanism which permits of accurate adjustment of the contact tension.

It i another object of the invention to provide a battery operated electric timepiece of the foregoing type where an adjustment of the contact mechanism may be made by the average jeweler without the necessity of returning the timepiece to the factory.

It is another object of the invention to provide a battery operated electric timepiece of the foregoing type wherein the tens-ion of the contact spring is clearly indicated on a suitable indicia in the timepiece, so that a jeweler may return the setting of the tension to its original value if it once is altered.

It is a still further object of the invention to provide an improved contact mechanism of the foregoing type Patented Jan. 9, 1962 "ice which is simple in construction and economical of manufacture.

These and further objects andadvantages of the invention will become more apparent upon reference to the following specification and claims and the appended drawing in which the sole figure is a partial plan view of a battery operated electric timepiece of the type shown in Koehler Patent No. 2,662,366 incorporating the contact mechanism of the present invention.

Referring to the figure of the drawing, there are shown two electro-

magnet coils

10 and 12 mounted on the

legs

14 and 16 of a core 18. Pole pieces 20- and 22 extend inwardly from the ends of the legs 14- and 16 and are preferably of the bifurcated type shown in assignees copending application Serial No. 743,370, filed June 20, 1958.

The balance staff 24 is mounted between the pole pieces 20 and 22 and carries the magnetic bar 26 which is shown in phantom. The pole pieces 20 and 22 are preferably bifurcated so that the ends of the bar 26 pass between the bifurcations. The balance stalf carries a roller 28 having a slot 30- therein which receives the vertical end 32 of a spring carried by the balance staff in the manner shown in detail in the aforementioned Koehler patent. The end 32 of this spring is free to move in the slot 30' to perform the indexing function in the manner described in that patent. The toothed index wheel is pivoted at 36 in a bridge 38 covering the train of the timepiece. The spring end 32 engages the teeth of the index wheel 34 and advances the index wheel in a clockwise direction as the balance staff oscillates.

The construction discussed thus far has been previously described in Koehler Patent No. 2,662,?) 66 and in assignees aforementioned application, Serial No. 743,370. The subject matter of the instant invention resides in the mounting of the elongated contact spring 40.

As in the timepiece shown in the Koehler patent, the contact spring 40 carries a cam 42 intenmediate its ends and this cam may be formed of a jewel or of a suitable metal such as carbo-loy. The end of the spring 40' carries a suitable contact 44 for engagement with the stationary contact of the timepiece (not shown) as in the timepiece shown in the Koehler patent. Each time that the index wheel 34 is advanced one tooth in a clockwise direction, the tooth engaging cam 42. urges the spring 40 downwardly in the figure of the drawing, so that the movable contact 44 engages the stationary contact of the timepiece to energize the electro-rnagnets and thereby magnetically attract the bar 26.

According to the invention the end 46 of the spring 40 is connected in any suitable manner, such as by welding, to the end 48 of an arm 50. The arm 50 is pivotally secured to the bridge 38 at 52 and is provided with a pointer 54 at its opposite end. Suitable indicia 56 are provided on the bridge 38 to cooperate with the pointer 54 to indicate the position of the arm 50. A locking screw 58 passes through a slot 60 in the arm 50 and screwthreadedly engages the bridge 38. The bridge 38 is arcuately cut away at 62 to permit pivotal movement of the end 48 of lever 50 about pivot 52.

It will be apparent that the position of the lever 50 determines. the tension with which the cam 42 is urged against the index wheel 34. Once the tension is properly set the locking screw 58 may be tightened to lock the lever in position, and this position may be accurately noted or recorded by means of pointer 54 and indicia 56. If it is subsequently necessary for a jeweler to upset the setting of the lever 50 for one type of repair or another, it is possible toaccurately reset the tension by simply returning the pointer 54 to the same position which it occupied before the original adjustment was upset. In this manner it becomes possible for jewelers to adjust the contact tension which heretofore has been adjustable only at the factory. r

It will be apparent that the mounting of the contact spring provided according to this invention is simple of adjustment and permits of accurate return to an original factory made setting. The construction is economical while at the same time providing material advantages in eliminating the necessity for return of timepieces to the factory.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is: I

1. 'In a combined contact and index mechanism for an electric timepiece, a toothed index wheel, an elongated contact carrying spring extending past said index wheel, cam means attached to said spring intermediate its ends and engaging said index wheel, a lever attached to one end of said contact spring, and means pivotally mounting said lever on said timepiece for adjustment of the tension with which said cam means engages said index wheel.

In a combined contact and index mechanism for an electric timepiece, a toothed index wheel, an elongated contact carrying spring extending past said index wheel, cam means attached to said spring intermediate its ends and engaging said index wheel, a lever attached to one end of said contact spring, means pivotally mounting said lever in saidtimepiece for adjustment of the tension with which said cam means engages said index wheel, and locking means for locking said lever in position.

3. In a combined contact and index mechanism for an electlic'timepiece, a toother index wheel, an elognated contact carrying spring extending past said index wheel,

cam means attached to said spring intermediate its ends and engaging said index wheel, a lever attached to one end of said contact spring, means pivotally mounting said lever in said timepiece for adjustment of the tension with which said cam means engages said index wheel, locking means for locking said lever in position, and indicia means cooperating with said locking means to accurately indicate the position of said mounting means.

4. In a combined contact and index mechanism for an electric timepiece, a toothed index wheel, an elongated contact carrying spring extending past said index wheel, cam means attached to said spring intermediate its ends and engaging said index Wheel, a mounting member attached to one end of said cont-act spring, means pivotally mounting said mounting member in said timepiece for adjustment of the tension with which said cam means engages said index wheel, locking means for locking said mounting member in position, and indicia means cooperating with said locking means to accurately indicate the position of said mounting means, said mounting member comprising a lever pivoted intermediate its ends to the framework of said timepiece, said end of said contact spring being connected to one end of said lever.

5. A mechanism asv set out in claim 4 wherein said lockingmeans comprises a screw passing through a slot in said mounting member and screwthreadedly engaging said framework of said timepiece.

6. A mechanism as set out in claim. 5 wherein the other end of said lever comprise a pointer and said indioi-a comprises a scale on said framework beneath said pointer.

References Cited in the file of this patent UNITED STATES PATENTS 835,516 Giroud Nov, 13, 1906 2,125,638 Hubert Aug. 2, 1938 2,626,500 Westlake Jan. 27, 1953 FOREIGN PATENTS 19,015 Great Britain July 7, 1904