US2889471A - Contact control for electric watch - Google Patents

Description

June 2, 1959 V R. M. JACKSON 1 2,889,471

CONTACT CONTROL FOR ELECTRIC WATCH Filed Aug. 22, 1957 2 Sheets-Sheet 1 FIG. 2 so L k )CI INVENTORY RODERICK M. JACKSON ATTORNEY June 2, 1959' R. M. JACKSON 2,889,471

CONTACT CONTROL FOR ELECTRIC WATCH Filed Aug. 22, 1957 2 Sheets-Sheet? II FIG. 3 32 2 FIG. 1

INVENTOR 86L RODERICK M. JACKSON ATTORNEY United States Patent ten Watch Company, Lancaster, Pa., a corporation of Pennsylvania Application August 22, 1957, Serial No. 679,641

7 *Claims. (Cl. 307-132) invention relates to an is'ochronal device and more particularl relates to a completely portable electrically driven isochronal device having an improved control switching arrangement. M IIi assignees" copending a plication Serial No. 660,003, filed May 31; 1957, there is disclosed an isochronal device which provides electric or electronic power having various characteristics through the use of a switching arrangement carried by an oscillating staff. That device is a self-powtiered device utiliZing an extremely small battery which sustains a staif in oscillator motion at an accurate and hired frequency. This stair carries contacts which control an electronic device which is itself the load for the system or which modifies the signalfroin the isochronal device to provide an output signal having the desired electrical characteristics. The staff carries at one time the prime meter, the oscillatory isochrohal arrangement, and the switching device, and according to certain embodiments or that invention, the contacts essential to the operation of the prime mover or isochronal element were also iitili'zed as the contacts of the signal generator. While this arrangement is generally satisfactory, it has been fo'lfliicl that there is a very definite limit on the current which can he carried by the ccntro1 switch contacts.

According to the present invention, it has now been found that it is possible to provide heavier control confacts and a more eirecti'v'e switching action it the stair carried contacts are eliminated and replaced with stationary contacts which cooperate with a single reciprocating contact. This reciprocating contact is carried and reciprocatcd by a pallet actuated by a roller carried on the stair. According to an important feature of the invention, the contact members are formed of magnetic material which it has been found prevents chattering, arcing and undesired opening or the circuit.

7 It is accordingly a primary object of the present invsn tion to provide an im roved isochronal device which is completely portable and electrically driven and which forms the controlling element of electric or electronic equipment.

It is another object of the invention to provide an isoehronal device of the foregoing type having magnetic contacts operated through a pallet assembly.

It is another object of the invention to provide an isochronal device of the foregoing type wherein the contact system minimizes chattering and arcing and is possessed of a long life.

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

Figure l is a plan view of the isochronal device with the balance cock removed;

:Figure 2 is a vertical section taken along the line 2-2 of Figure 1';

Figure 3 is a partial vertical view taken along the line 3-3 of Figure l and showing the shunt arrangement;

Figure 4 is a partial detail plan view of the roller table and pin shown in Figures 1 and 2;

Figure 5 is a schematic showing of the contact system arranged to provide a square wave signal;

Figure 6 is a schematic diagram showing the use of the isoc'hronal device as an inverter; and

Figure 7 is an isochronal device utilized to control the flashing of a lamp.

Referring to Figures 1, 2 and 3 the isochronal element of the invention comprises a mounting plate 10 which carries a stall 12 in a bearing 14, which may be a jeweled bearing if desired. The upper end of the staif 12 is journaled in a similar bearing in a balance cock 16 mounted on a mounting block 18 by means of a pair of screws which are received in holes 20 in the mounting block 18.

The stafi 12 carries a balance wheel shown generally at 22 and which consists of a hub 24, crossarms 26 and rim 28. Suitable poising and balancing screws 30 are mounted in the rim for counterbalancing the coil presently to be described. The rim 28 of the balance wheel is interrupted at the side opposite the screws 30 and a generally pie-shaped coil 32 is mounted between the ends of the rim by means of a pair of small brackets 34 and 36 which are cemented to the coil and attached to the rim by means of screws 38 and 40. One end of the coil 32 is connected to the rim 28, as at 42, while the other end of the coil is wrapped around and soldered to a bracket 44 to which contact strip 46 is attached by means of a screw 48.

The contact strip is secured to the bracket 44 by the screw 48 passing through a slot 50 in the contact strip. This slotted connection allows the contact strip to be positioned radially of the balance wheel to provide for any small differences in the size of the coils or in the distance that the coil is mounted from the balance staff.

A roller table 52 is carried by the hub 24 and serves to support the contact strip 46. A layer of insulation 54 prevents the contact strip 46 from contacting the roller table 52 and hub 24. The contact strip curves substantially in a semi-circle around the staff and terminates in a vertical finger 56. The roller table also carries on the extended portion thereof a pin 58.

A spiral hairspring 60 is mounted on the staff 12 and has its outer end fastened to a pin 62 on the balance cock 16. A regulator assembly 64 is also mounted on the balance cock 16 and has a pin 66 engaging the hairspring 60 in a conventional manner.

-A plate 68 secured to the mounting plate 10 carries a first post 76 and a second post '72. Each of these posts has respectively mounted thereon a collet 74 and 76 and each post is insulated from the plate 68 and mounting plate 10 by an insulating sleeve 78. The collets 74 and 76 are friction held to their respective posts and may be rotated about the posts. Slots 80 and 82 are formed in the respective collets 74 and 76 and are angularly positioned with respect to each other by the aforementioned rotation.

A controlling spring arm 84 is mounted in the slot 80 of coll'et 74. A second spring arm 86 is mounted in the slot 82 of the co'llet 76. The second spring arm 86 is mounted at a slightly higher level above the mounting plate 10 than is the controlling spring arm '84 and is pre vented from swinging over and beyond the arm 84 by a tab 88 which projects upward from the spring arm 84 into the path of swinging movement of the arm 86. The second spring arm 86 carries at its end a substantially conical shaped contact 90 adapted to engage the vertically positione'd end '56 of the contact strip 46.

' The first spring arm 84 mounted in the collet 74 serves as a controlling and limiting member, through engagement of the second spring arm 86 with the vertical tab 88 and is hereafter referred to as the controlling spring arm. The second arm 86 carries the contact 90 and is hereinafter referred to as the contact carrying spring arm. The controlling spring arm 84 is longitudinally adjustable in the slot 80, which longitudinal adjustment controls the position at which its end 92 "contacts the forward face of the pin 58 as shown in Figure 4, being adjustable between the limits as shown in the solid lines to that shown in the broken lines. This adjustment can be used to partially control the duration of contact.

The controlling spring arm 84 is still further adjusted in its angular relation to the contact carrying spring arm 86 by rotating the collet 74 about the post 70. The latter of these adjustments can be made during the operation of the isochronal device. The contact carrying spring arm 86 is adjustable in a like manner, that is, longitudinally in the slot 82 and angularly by moving the collet 76 about its post 72. This, too, partially controls the duration of contact. Further, the angular adjustment of the collet 76 on the post 72 provides stress in the contact spring arm 86 and determines the force between the contact 90 and the upright end 56 of contact strip 46.

Each of the spring arms is normally positioned angularly so that if unrestrained they would cross one above the other. This crossing, however, is prevented by the engagement of the spring arm 86 with the vertical tab 88 so that both spring arms are maintained in a stressed position, each directing a force against the other.

" The spring arms are rectangular in cross section and are comparatively long. The comparative length of the spring arms permits the balance wheel on its oscillation in a clockwise direction in Figure 1, wherein no contact is made, to move the spring arms from the path of the contact with a minimum expenditure of energy. The pin 58 is generally hemispherical in shape with the flat surface 92 disposed to engage the controlling spring arm 84 when the balance wheel rotates in a counterclockwise direction. The hemispherical backside 94 of the pin is cut away at 96 so as to permit a quick disengagement of the pin with the controlling spring arm.

A pair of small cylindrical magnets 98 and 100 are mounted on a shunt member 102 which is received in a cutaway portion 104 of the mounting plate 10. The magnets are disposed beneath the radial arms 106 and 108 of the pie-shaped coil 32. The magnets are secured in position by being friction-fitted into bores in a non-magnetic member 110 which is fastened to the mounting plate 10. A second shunt member 112 overlies the magnets 98 and 100 and is mounted on a pair of posts 114 and 116 carried by the bottom shunt 102. The two shunts are secured together onto the posts by a pair of screws and the posts and screws may be of a magnetic material. The upper surface of the magnets 98 and 100 are of opposite polarity. A suitable battery is connected to the mounting plate 10 to which one end of the coil is grounded through the balance wheel, staff, hairspring, balance cock and mounting post 18. The other terminal of the battery is connected to the post 72 which carries the contact spring arm 86. Upon oscillation of the balance wheel current flowing from the battery energizes the coil at the moment that it is in the magnetic field and produces a magnetic thrust against the coil which is transmitted to the balance wheel. This impulse together with the reaction of the hairspring produces oscillating motion of an isochronal nature.

The oscillation of the balance wheel moves the roller table 52 and its pin 58 and contact finger 56. The oscillating movement of the pin 58 and the contact member 56 causes the forward face of the pin 58 to engage the end of the controlling spring arm 84 and move it upwardly. Swinging movement of the controlling arm is followed by a like movement of the contact carrying spring arm 86 in the same direction by reason of the stress within the arm. Further movement of the pin 58 in a counterclockwise direction moves the controlling arm 84 upwardly causing the end to move across the forward face 92 and bringing the contact into engagement of the contact point 90 wtih the face of the finger, the movement of the contact carrying spring arm is restrained and the stress within that arm is partially absorbed at the contact making point.

It is thus seen that the contact 90 is urged against the face of the finger 56 with a predetermined force so that there is no possibility of chatter between the contact point and the finger.

This minimizes arcing between the contact point and finger and holds the contact against the finger throughout the contact making period with substantially the same force. Further movement of the roller table and its accompanying pin 58 moves the end of the controlling spring arm 84 over the rounded edge 118 of the pin 58 whereupon it drops sharply away from the pin because of the cutaway face 96. This sharp dropping snaps the upright tab 88 of the controlling spring arm against the contact carrying spring arm causing a sharp break in the contact, snapping the spring arms 84 and 86 back to a normal position.

During the contact making operation, that is from the time the contact 90 contacts the face of the finger 56 until it is broken by movement of the controlling spring arm 84, there is a relative motion across the face of the upright finger 56 by the contact 90. This tends to preserve a clean contact-making surface at all times.

During the backward movement of the balance wheel the spring arms areengaged by the pin 58 and swung from the path of its movement. This engagement takes place by the end of the controlling arm 84 engaging the face 96 of the pin 58 and moving both the spring arms downwardly until the end of the controlling spring arm 84 slips past the edge 118 of the pin. The comparative long length of the spring arms makes it possible for the balance wheel to push the spring arms out of position on its backward oscillation with a minimum expenditure of energy and with a minimum of interference with the isochronal movement.

The battery used to energize the coil may he an extremely small battery of the disc type such as is shown in assignees copending application Serial No. 550,565, filed December 2, 1955. With such a small battery the entire isochronal element may be constructed in ex tremely miniaturized form and is capable of running for extended periods of time in excess of a year.

According to the present invention, the contacts 132, 134 and 136 are formed of a magnetic metal having the relatively high conductivity desired. I have found that this provides a positive contacting action which prevents the pallet contact from being accidentally jarred loose between impulses from the balance wheel 22. This arrangement also prevents chattering and arcing between the contacts. Since the balance wheel serves as an isochronal element, it is undesirable to remove any appreciable amount of power from the balance wheel during the course of its oscillation. Accordingly, if the balance were to be utilized to stress the resilient spring in order to hold the pallet contact 132 in engagement with either of stationary contacts 134 and 136, this would:

deleteriously affect the timekeeping accuracy and hence,

the control function of the unit. With magnetic contacts, the balance wheel and pallet are utilized to bring the pallet contact 132 so close to either of the stationary contacts 134 and 136 that magnetic action makes the contact and holds the contact until it is broken by the pallet returning in the opposite direction.

Referring to Figure 5, the isochronal control unit is shown serving as a square wave generator. The stationary contacts 134 and 136 are connected to a load resistor which is connected in series with a battery 152. The

pallet 126 is grounded through its journal 128 and the lower terminal of the battery 152 is also connected to ground to form the return circuit. It will be apparent that as the balance wheel 22 oscillates, a square wave signal is formed on the load resistor 150.

Referring to Figure 6, the isochronal device is shown as a chopper to transform direct current into pulsating direct current. Stationary contacts 134 and 136 are connected together and to one terminal of the primary 154 of a transformer 156. The other terminal of the primary 154 is conencted to a battery 158 which is connected to ground. The secondary 160 of transformer 156 is connected to a load 162. As the balance wheel oscillates the direct current from the battery 158 is transformed into a pulsating direct current in the transformer 156 which may be utilized in any suitable load 162. It will be apparent that the voltage may be stepepd up or down.

Referring to Figure 7, there is shown a still further embodiment of the isochronal unit wherein it is utilized to flash a light. The stationary contacts 134 and 136 are connected together and to one terminal of a suitable lamp 164. The other terminal of this lamp is connected to a battery 166 which is grounded. It will be apparent that as the balance wheel oscillates and the movable contact 132 alternately engages stationary contacts 134 and 136, the lamp 164 is alternately turned on and off. Such a device may find uses in numerous fields, one of which may be as roadside flashers wherein the isochronal unit is constructed in a rugged and simplified manner.

It will be apparent that a unit of this type may be supplied in a very small size and may be completely portable. The unit is operative over very long periods of time dependent only upon the life of the battery involved. While two batteries have been discussed, one operating the isochronal element and the other operating the load, it will be obvious that the load battery may be used to drive the isochronal unit also. While it will be apparent that the contacts illustrated can carry only a limited current, it will also be apparent to those skilled in the art that it is possible to utilize this limited current to control high current switching devices such as thyratrons or similar devices. Control circuits suitable for this use are shown in assignees copending application No. 660,003, filed May 31, 1957.

The invention may be embodied in other specific forms without departing from the spiiit or essential characteristics thereof. The present embodiments are 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:

l. A miniature isochronal device comprising a frame member, a staff mounted for oscillation in said frame member, a coil mounted for oscillation with said staff,

means creating a magnetic field through which said coil oscillates, a battery cooperating with switching means for energizing said coil periodically, and a pallet driven by said staff and controlling switch contacts for periodically closing a connection to a load, said switch contacts being magnetic.

2. A miniature isochronal device comprising a frame member, a staff mounted for oscillation in said frame member, a coil mounted for oscillation with said staff, means creating a magnetic field through which said coil oscillates, a battery cooperating with switching means for energizing said coil periodically for oscillation in one direction, spring means for oscillating said coil in an opposite direction, and a pallet driven by said staff and controlling switch contacts for periodically closing a connection to a load, said switch contacts being magnetic.

3. A miniature isochronal device as claimed in claim 2 wherein said spring means is a hairspring.

4. A miniature isochronal device comprising a frame member, a staff mounted for oscillation in said frame member, a balance wheel carried by said staff, a coil mounted eccentrically on said balance wheel, means creating a magnetic field through which said coil oscillates, a battery cooperating with switching means for energizing said coil periodically, and a pallet driven by said staff and controlling switch contacts for periodically closing a connection to a load, said switch contacts being magnetic.

S. A miniature isochronal device comprising a frame member, a staff mounted for oscillation in said frame member, a coil mounted for oscillation with said staff, means creating a magnetic field through which said coil oscillates, a battery cooperating with switching means for energizing said coil periodically, a pallet driven by said staff and controlling switch contacts for periodically closing a connection to a load, said pallet being forked at one end to engage a pin carried by said staff, said pallet carrying a magnetic contact at the other end, a metal shaft carrying said pallet and being electrically connected to the contact carried by said pallet, and at least one stationary magnetic contact which is periodically engaged by said pallet carried contact as said staff oscillates.

6. An isochronal device as set out in claim 5 wherein said pallet carried contact and stationary contact are connected to make and break a circuit from a source of DC. power to a transformer.

7. An isochronal device as set out in claim 5 wherein said pallet carried contact and stationary contact are connected to make and break a circuit from a source of DC power to a lamp to cause periodic illumination of said lamp.

References Cited in the file of this patent UNITED STATES PATENTS 2,266,037 Henninger Dec. 16, 1941 2,278,061 Dalkowitz Mar. 31, 1942 2,288,183 Dalkowitz June 30, 1942

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