US2948821A

US2948821A - Motor for electric watches

Info

Publication number: US2948821A
Application number: US631686A
Authority: US
Inventors: John A Van Horn; Philip E Biemiller; James H Reese
Original assignee: Hamilton Watch Co
Current assignee: Hamilton Watch Co
Priority date: 1956-12-31
Filing date: 1956-12-31
Publication date: 1960-08-09
Anticipated expiration: 1977-08-09

Description

1960 J. A. VAN HORN ETAL 2,943,821

MOTOR ELECTRIC WATCHES Filed D60. 31, 1956 3 Sheets-Sheet 1 INVENTORS 1 Jo/mAVan Horn, PM]? tTBfemfl/eriq Jamasfl Eees e ATTORNEY 1960 .1. A. VAN HORN ETAL 2,943,821

MOTOR ELECTRIC WATCHES Filed D60. 31, 1956 I 3 Sheets-Sheet 2 IN VENTOR v John AVafl Horn, Pfiz'fi 'v EBiemi/ler James [1 Fee 5 6 BY W ' ATTORNEY Aug. 9, 1960 .1. A. VAN HORN ETAL 2,948,821

' MOTOR ELECTRIC WATCHES Filed Dec. 31, 1956 3 Sheets-Sheet 3 INVENTOR JofinA. Van Horn, P/II'II 'U [.fiiemi/kr Mlzmesfifieese ATTORNEY United States Patent MOTOR FOR ELECTRIC WATCHES John A. Van Horn, Lancaster, Philip E. Biemiller, Landisville, and James H. Reese, Manheim, Pa., assignors to Hamilton Watch Company, Lancaster, Pa., a corporation of Pennsylvania Filed Dec. 31, 1956, Ser. No. 631,686

8 Claims. (Cl. 310-27) source and the means for converting the electrical energy into mechanical energy. Further, it is obvious that there is a definite limit upon the amount of electrochemical energy which can be built into a wrist watch case. Because of the space limitation it is essential that the component parts of the electric wrist watch, including the battery, the oscillating frequency controlling element, the magnets maintaining the permanent magnetic field, and the mechanical movement, be designed so that the space within the watch casing is utilized with a maximum degree of efficiency. While many attempts have been made to solve this problem satisfactorily, we are not aware that any electric wrist watch has ever been successfully marketed.

It is accordingly a primary object of the present invention to provide an electric wrist watch wherein both the source of electrochemical power and the means for transforming the electric power into mechanical power are designed so as to utilize the space within the watch casing with a maximum degree of efficiency.

It is another object of the invention to provide an electric watch designed so as to provide a relatively large space for the electrical drive means.

It is another object of the invention to provide an electric watch having a rotatable coil which also serves as the balance wheel of the watch and which occupies a much larger space than heretofore occupied by balance wheels in watches.

It is another object of the invention to provide an electric watch wherein the balance staff is concentrically located within the watch casing.

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

Figure 1 is a plan view of a watch constructed according to the present invention;

.through 3 with the upper pole bridge removed showing the train bridge and wheels;

Figure 5 is a plan view of the watch of Figures 1 through -4 showing the contact system; and v Figure 6 is an illustration of the indexing system of the watch of Figures 1 through 5. I

Referring more particularly to the figures of the draw- 5 ing, particularly Figures 1 and 3, thereis shown a watch 1' consisting of a pillar plate 10 having a first arcuate pole piece 12 mounted thereon at one side thereof, and having 'lower pole bridge arms 58 and 60.

Ice 2,948,821

-Patented Aug. 9, 1960 a second arcuate pole piece 14 mounted at the other side thereof diametrically opposite pole piece 12. Arcuate pole piece 12 is provided with a sector shaped extension 16 having side faces 18 and 20, while arcuate pole piece 14 is provided with a sector shaped extension 22 having vertical side faces 24 and 26.

Pole pieces

12 and 14 and their sector shaped

extensions

16 and 22 are formed of a magnetic material such as low carbon steel. The pillar plate 10 is formed of a suitable non-magnetic material such as brass or nickel silver.

The outer peripheral faces of

extensions

16 and 22 of

pole pieces

12 and 14 are fiush with the outer periphery of the pillar plate 10. A permanent magnet 28 in the shape of a half ring extends about the upper half of the pillar plate and has ends 30 and 32 which accurately engage both the arcuate surfaces 34 and 36 of

pole pieces

12 and 14 and the side surfaces 18 and 24 of their

extensions

16 and 22, as is best seen in Figure l. A primary cell 38 also in the shape of a half ring encircles the lower half of the pillar plate, as seen in Figure 1, and has

ends

40 and 42 engaging the arcuate surfaces 44 and 46 of

pole pieces

12 and 14 and the side faces 20 and 26 of

pole piece extensions

16 and 22. The internal construction of the primary cell may be similar to that disclosed in assignees copending application Serial No. 558,151, filed January 9, 1956, now abandoned.

Extending from the lower edge of the right pole piece 14 is a pole bridge 48 which lies on the pillar plate 10, as seen in Figure 3. This is referred to as the lower pole bridge. The lower pole bridge 48 has diverging vertical sides 50 and 52 and terminates in a vertical side 54 just over the center line of the pillar plate. A square recess 56 is cut into the lower pole bridge so as to form a pair of lower pole bridge arms 58 and 60.

The left pole piece 12 is provided with a similar pole bridge 66 at its upper edge in Figure 3, and this .pole bridge extends inwardly towards the center of pillar plate 10. The pole bridge 66 is spaced from the pillar plate 10 and is referred to as the upper pole bridge. Upper pole bridge 66 is provided with a pair of diverging

side faces

68 and 70 and with a vertical inner edge 72 which is just on the other side of the center line of the pillar plate from the pole piece 12. Upper pole bridge 66 is provided with a square recess 74 defining a pair of upper

pole bridge arms

76 and 78. It will be noted that the upper

pole bridge arms

76 and 78 partially overlie the In these overlying portions the thickness of all pole bridge arms is increased so as to provide oppositely disposed pole bridge arm faces 62 and 64 on the lower pole bridge and 80 and 82 on the upper pole bridge, as seen in Figure 2. It will be understood by those skilled in the art that a pair of intense magnetic fields of like magnetic polarity are provided between the pole bridge faces 62 and 80 and 64 .and 82.

Fastened to the top of the extension 22 on arcuate pole piece 14 is a tab 84 of a balance cock 86 which extends into the center of the pillar plate. Balance cock '86 is secured to extension 22 on pole piece 12 by means pillar plate 10. A regulator pointer 96 connected to a conventional regulator assembly is also carried atop the balance cock 86.

Carried by balance staff 92 is a coil, shown generally at 98, consisting of a pair of spaced parallel sides 100 'and 102 joined by

arcuate ends

104 and 106. The coil I 98 may be encased in a sheet of synthetic resin 108, which is shown as being transparent for ease of illustration. The sheet of synthetic resin 108 is in turn carried by 'a collet 110, best seen in Figure 2. A suitable hair spring 112 is also carried on balance staff 92 by' means of a collet 114.

Referring to Figure 5, the balance staff 92 carries a roller plate 116 of insulatingmaterial uponwhich is mounted a pair of

sapphire insulators

118 and 120. Between insulators 118 and 120 a gold' contact point 122 is mounted and this is connected to one end of the coil 98. The upper sapphire insulator-120 in Figure 5 has a diagonal face 124, while the lower sapphire insul'atdr122 has a diagonal edge 126. The diagonal surfaces 124 and 126 converge in the direction of a contact arm, but insulator 120' is longer than insulator 126 sothat surface 124 protrudes farther from the" balance staff than does surface 126. The gold contact point 122' has a: diagonal surface 123 which is an extension'o'f the diagonal surface 126 of insulator 118;.

Cooperating with the sapphire insulators and gold contact point is. a contact spring arm 130 carried by a spring clip 132' mounted on. an insulator, not shown, on the pillar plate. This spring. clip is connected to one terminal of the battery 38. Theother terminal of battery 38 is grounded to the watch frame. One terminal of the coil 98' is connected to the balance wheel so that it is connected to the grounded terminal of the battery. It will thus be seen that. a circuit to the; coil 98' may be completed. when the contact spring'130 contacts the gold contact point 128.

Referring to Figure 5, it willbe seen that when the coil 9% rotates in a clockwise direction the end of contact spring arm 130 contacts gold contact point 128 momentarily to energize the coil. The roller table 116 is so disposed on the balance staff 92 that this contact occurs when the parallel coil sides 10,0 and 102 are. in the position shown in Figure 1. When these coil sides are in this position it will be seen that an upper portion of coil side 100 is between the pole bridge faces 62 and 80, whilev the lower end. of coil sidev 102 is between the pole bridge faces 64 and 82. If the left end of permanent magnet 28 is a north pole and the right end is a south pole, as shown in Figure 1,. and if the. coil 98' is connected so that current flows therethrough in aclockwise direction in. Figure 1, the energization of the coil. causes impulses to

coil sides

102 and 100 tending to rotate the coil in a clockwise direction.

After such an impulse the coil. rotates in a clockwise direction until the hair spring 112 arrests its movement and reverses its direction of rotation. As the coil moves in a counterclockwise. direction the contact spring arm 130 is prevented from engaging the gold contact point 1'28 by the extending end 124 of sapphire insulator 120, so that the coil rotates counterclockwise freely until the hair spring 112 again reverses its direction of rotation. The coil then commences to rotate in a clockwise direction and contact spring arm 130 again contacts gold contact point 128 to provide another impulse to move the; coil in a clockwise direction. This oscillation continues at a rate determined by the characteristics of, the hair spring and balance wheel assembly, in a manner well known to those skilled in the art. Other types of contact mechanisms may also be used, such as those disclosed in assignees, copending applications Serial No. 406,396, filed January 27, 1954, now Patent No. 2,806,908 and Serial No. 551,791, filed December 8, 1955, now Patent No. 2,889,410.

Referring to Figures 3 and 4, a train bridge 136 is mounted on pillar plate 10 and provides bearing support for a train 138, seen in Figure 4. This train may be of the type disclosed in assignees copending application Serial No. 409,934, filed. February 12, 1954, now Patent No. 2,888,797.

Referring to Figure 6, the train 138 is driven by means of an index. roller 140 mounted on the balance staff 92 and'having a sector 142 extending therefrom. The sector 1'42 cooperates with a pair of intermeshing toothed in- 4

dexing wheels

144 and 146 carried beneath the coil as seen in Figure 2'. A suitable detent, not shown, may be provided for the indexing wheels and this may be of the type shown in assignees copending application Serial No. 409,934, filed February 12, 1954, now Patent No. 2,888,797. As the sector 142 rotates in a counterclockwise direction it clears tooth 1 48 on index wheel 144 and engages tooth onindex wheel: 146 rotating index wheel 146 a half tooth in a clockwise direction. The sector 142' continues past tooth- 150i The clockwise movement of index wheel 146' moves index wheel 144 in a counterclockwise direction through the meshing gears of the two index wheels to place tooth 148 in a position where: it is engaged by the sector 142 when the sector returns on the clockwise oscillation of the balance staff. This moves index wheel 144 a half tooth in a counterclockwise direction, which is the same direction in which it is moved by the interengagement with index wheel 146. The index wheel 144 thus constantly rotates in a counterclockwise direction and this movement is transferred to the train by means of a pinion 152 errgaging the wheel 154. This indexing is described in further detail in assignees copending application Serial No. 409,934, filed February 12, 1954, now Patent No; 2,888,797.

It will be apparent from the foregoing that we have disclosed an electric wrist watch movement which makes maximum use of the space available in the watch case. A relatively large oscillating coil is utilized cooperating with a pair of spaced magnetic fields which are located at a relatively long distance from the axis of rotation of the coilthereby providing a high torque without increasing the battery drain. Both the source of magnetism and the source of the electrochemical energy are provided in half ring form and the oscillating coil which serves as the balance wheel rotates about an axis concentric with the center of these elements.

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 the United States Letters Patent is:

1. In a battery powered timepiece, a battery, a coil mounted on a staff for oscillation, a hairspring associated with said staff, an arcuate magnetic member, a first pole piece engaging one end of said. magnetic member and having an upper portion extending toward said staff, a second pole piece engaging the other end of said. magnetic member and having a lower portion extending toward said staff, said pole pieces having arcuate, portions mating with arcuate portions. on the inner side of said arcuate magnetic member, said upper extending portion terminating in a pair of upper pole arms, said lower extending portion terminating in a pair of lower pole arms which at least partially underlie said upper arms in spaced relation, said extending portions being plate-like and having diverging side walls, said coili having a pair of parallel sides and being mounted for movement through the spaces between said upper and lower arms, and means synchronized with the movement of said coil for periodically connecting said coil with said battery.

2. A device :as set out in claim 1 wherein said arcuate magnetic member is substantially in the shape of a half ring.

3. A device as set out in claim 1 wherein said staff is located at the center of the radius of curvature of said arcuate magnetic member, and wherein said spaces between overlying portions of said arms are disposed on diametrically opposite sides of said stafi.

4. A device as set out in claim 1 wherein the overlying portions of said arms are of a greater thickness than the extending portions of said pole pieces.

5. A device as set out in claim 1 wherein said battery is arcuate.

6. A device as set out in claim 1 in which said battery is substantially in the shape of a half ring having end portions engaging said pole pieces so that said magnetic member and said battery form a substantially complete ring.

7. A device as set out in claim 6 wherein said staff is located at the center of the ring formed by said arcuate magnetic member and said battery.

8. A device as set out in claim 6 wherein the overlying portions of said arms are of a greater thickness than the extending portions of said pole pieces.

References Cited in the file of this patent UNITED STATES PATENTS