US2942410A

US2942410A - Stem actuated seconds setting stopstart mechanism

Info

Publication number: US2942410A
Application number: US767221A
Authority: US
Inventors: Kenneth H Schoenrock
Original assignee: Hamilton Watch Co
Current assignee: Hamilton Watch Co
Priority date: 1958-10-14
Filing date: 1958-10-14
Publication date: 1960-06-28
Anticipated expiration: 1977-06-28

Description

June 28, 1960 K. H. SCHOENROCK 2,942,410

STEM ACTUATED SECONDS SETTING STOP-START MECHANISM Filed Oct. 14, 1.958

{3) INVENTOR Kennefh Schoen rock ATTORNEYS States STEM ACTUATED SECONDS SETTING STOP- START MECHANISM Filed Oct. 14, 1958, Ser. No. 767,221

8 Claims. (Cl. 58-79) This invention relates to electric watches and more particularly relates to a mechanism for utilizing the motion of the setting stem of the watch to perform secondary functions during the time that the setting stem is used to set the watch hands.

In a battery powered electric watch of the general type shown in assignees application of Biemiller and Reese, Serial No. 578,843, filed April 13, 1956, the balance assembly carries a moving coil which cooperates with a series of stationary permanent magnets to impulse the balance wheel and staff which in turn drives the train of the watch through a suitable indexing mechanism. In this type of arrangement, the stem which is usually used to wind the main spring of an ordinary watch has no function other than to be used for the setting of the hands. In prior Watches the stem has thus been designed to move from a normal in position to an out setting position for setting the hands of the watch. In the aforementioned electric watch of assignee, in the in position, a wheel carried by the clutch lever is disengaged from the minute wheel so that ordinarily there is no drag on the train because of the setting wheel.

This type of Watch is designed to use an absolute minimum of electrical power so that a maximum life can be obtained with an extremely small source of electro-chemical power. In the watch shown in the aforementioned copending application, the power is periodically connected to the moving coil by means of a com mutating arrangement, so that if the balance assembly comes to rest, no power is supplied to the coil and the watch will not start. That is to say, the watch is not self-starting and has to be given a shake or some agitation in order to cause the balance wheel to oscillate until the first contact is made and the coil energized by the primary cell.

Another feature of the operation of the same type watch is the fact that the power drive extends from the balance wheel, through the indexing gear, and then through the train of the watch to the hand. Upon resetting by the use of the previously described setting stem, the wheels of the train are caused to spin in a manner which, on some occasions causes diificulties in the watch.

In one arrangement designed to eliminate this difficulty assignee has utilized a mechanism actuated by the movable setting stem, so that when the stem is moved out in order to set the hands of the watch, the index mechanism is held in position so that the wheels of the train will not spin. In addition to this, the mechanism also brings the balance assembly to rest in a predeter mined position such that the commutator or switching arrangement disconnects the battery from the coil to conserve the battery. This same predetermined position also insures that the hairspring which causes the balance wheel to oscillate is in a cocked position so that upon release of the setting stem, the energy stored in the hairspring returns the balance wheel to oscillation and starts the watch. This is intended to obviate the necessity for the shaking or other agitation previously necessary to atent I start the watch and to eliminate undue strain on the pivots of the balance wheel staff.

According to the present invention, there is provided an improved mechanism for performing the same function wherein the locking of the balance wheel and consequently the index wheel is more positive and wherein the watch is caused to start by means of a positive ion pulse imparted to the balance staff through the movement of the stem to its inactive position.

It is accordingly a primary object of the present invention to provide in a battery operated electric watch a mechanism which cooperates with the setting stem to simultaneously prevent spinning of the train wheels upon setting of the watch, stop motion of the balance wheel during setting of the watch, and positively impulse the balance wheel upon the termination of the setting operation so as to again start the watch.

It is another object of the invention to provide an electric watch having the foregoing type of mechanism which is provided in such a manner as to necessitate the addition of an absolute minimum number of parts to the already crowded watch case.

These and further objects and advantages of the invention will become more apparent upon reference to the following specification and claims and appended drawing wherein:

Figure 1 is a top plan view of the mechanism of this invention; and

Figure 2 is a schematic of the electrical circuit of the watch.

Reference is had to the copending application of Reese and Detwieler showing a similar mechanism and its environment and to the application of Biemiiler and Reese, Serial No. 578,843, filed April 13, 1956, showing the details of the electric watch. Referring to the drawing, a pillar plate generally indicated at it has mounted therein a balance stalf l2 and a reciprocable setting stem 14, having a stem end 16. The setting stem is adapted to be moved longitudinally to an outer hand setting position and returned to an inner inactive position.

The balance staif 12 carries a roller 18' having a slot 2i) in its peripheral edge. This same roller also carries an indexing jewel 22 which is adapted to engage the teeth 24 of an indexing gear 25. As is described in detail in assignees copending application of Bienu'ller and Schoenrock, Serial No. 623,176, filed January 2, 1957, the slot 20 on the roller 18 is positioned so that it is generally opposite to the jewel 22 for a purpose presently to become apparent.

A lever 26 is attached to the pillar plate It by means of a shoulder screw 28. This lever has one end 30 formed with an upstanding tab 3'2 which is engaged by the end 16 of the setting stem 14. Attached to an edge 34 of the lever 26, as by means of a pair of welds, is one end 36 of a spring 38 having its other end 40' in engagement with a pin 42 or other abutment ahixed to the pillar plate 10. The spring 38 is under tension in this position and urges the lever 26 to rotate in a clock wise direction. In the position of the lever and setting stem shown in the figure of the drawing this tendency to rotate is stopped by the abutment of the tab 32 against the end 16 of the setting stem 14 which is shown in its inward or inactive position.

The end 44 of the lever 26 is formed with a cam finger 46 which is adapted to enter the slot 2% in the roller 18 when the setting stem 14 is pulled out in order to set the hands of the watch. As the setting stem is pulled out, the lever 26 pivots under the influence of the spring 38 bringing the cam finger 46 into the slot 20' in the roller 18. A portion of the pillar plate may be milled out to provide a guide for the end 44 of the Patented June 28, 1960 lever 26 as described in further detail in the copending' application of Reese and Detwieler. The position of the lever when the cam finger 46 engages the slot 20 is .shown in broken lines in the drawing.

the setting stem 14 is turned in order to set the hands of the watch, spinning of the train wheels is prevented by the teeth 24 of the indexing gear 25 engaging the indexing jewel 22 which is positively locked in position by means of the cam finger and slot.

The position of the roller 18 is so arranged with re spect to the electrical contact carried by the balance staff 12 and designated by a switch 50 in Figure 2 that in the position in which the balance staff is brought to rest, the circuit between the primary cell 52 which powers the watch and the coil 54 on the balance wheel is broken to insure that there is no drain on the battery 52 during the time that the hands of the watch are being set. The switch 50 may be a contact mechanism of the type shown in assignees copending application Sen'al No. 551,791, filed December 8, 1955, and the coil 54 may be of the type shown in the previously mentioned Biemiller and Reese application Serial No. 578,843, filed April 13, 1956.

While the balance wheel and hairspring are not shown, the roller 18 is so positioned on the staff 12 that when the lever 26 is pivoted to the broken line division so that cam finger 46 enters slot 29, the hairspring is cocked in such a manner as to tend to rotate the balance staff and roller in a counter-clockwise direction. This brings the right side 48 of the slot 20 into engagement with the right side of the cam finger 46. When the setting stem 14 is returned to its inner inactive position and the lever 26 rotates back to the solid line position shown in the drawing, the cam finger 46 positively pushes the side of'the slot 20 to the right or in a clockwise direction to positively move the balance wheel and thereby start the watch. This action is positive in nature and does not rely upon the energy stored in the hairspring for the restarting action.

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 de soription, 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:

l. In an electric watch having a reciprocable setting stem, a spring driven balance staff, a roller on said staff and a projection on said roller for driving a train index- 'ing gear by periodically engaging the teeth thereof; a

being so disposed with respect to said projection that said of said indexing gear when said conjugate surface of said roller is engaged by the mating surface of the other end of said lever to prevent rotation of said indexing gear and its connected train.

2. An electric watch as set out in claim 1 wherein said lever is movable by said setting stem' into a position wherein said other end engages said roller so that said conjugate surfaces are in mating position, and into a second position wherein said other end of said lever is clear of said roller, said conjugate surfaces being so shaped that movement of said lever from said first to said second position imparts a positive impulse to said roller to cause rotation of said staff.

3. An electric watch as set out in claim 2 wherein said surface on said roller is so disposed that the spring driving said balance staff is cocked during engagement of said lever with said surface on said roller.

4. An electric watch as set out in claim 2 including a battery and coil means periodically energized by said battery under the control of switching means actuated by movement of said balance staff, said surface on said roller being so disposed that said battery is disconnected from said coil means when said lever engages said roller.

5. In an electric watch having a pillar plate having mounted therein a reciprocable setting stem having an outer setting position and an inner inactive position, a spring driven balance staff, a roller on said staff and a projection on said roller for driving a train driving indexing gear by periodically engaging the teeth thereof; a lever pivotally secured to said pillar plate and having one end in engagement with said setting stem, spring means connected to said lever and urging said one end thereof into constant engagement with said setting stern so that upon reciprocation of said setting stem said lever rotates, a cam finger on the other end of said lever, said roller having a slot therein shaped to receive said cam finger when said setting stem is in its setting position to hold said roller and staff stationary when so engaged, said slot on said roller being so disposed with respect to said projection that said projection is held in the path of movement of the teeth of said indexing gear when t i said slot of said roller is engaged by said cam finger on 7 said lever to prevent rotation of said indexing gear and its connected train.

6. An electric watch as set out in claim 5 wherein said cam finger and slot are so shaped that movement of said lever out of engagement with said roller imparts a positive impulse to said roller to rotate said balance staff.

7. An electric watch as set out in claim 6 wherein said slot on said roller is so disposed that the spring driving said balance staff is cocked during engagement of said cam finger and said slot.

8. An electric watch as set out in claim 6 including a battery and coil means periodically energized by said battery under the control of switching means actuated by movement of said balance staff, said slot on said roller being so disposed that said battery is disconnected from said coil means when said slot is engaged by said cam finger.

References Cited in the file of this patent UNITED STATES PATENTS Ensign et al. Dec. 23, 1958