US2800799A

US2800799A - Electric clock drive

Info

Publication number: US2800799A
Application number: US371821A
Authority: US
Inventors: Peter R Contant
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1953-08-03
Filing date: 1953-08-03
Publication date: 1957-07-30
Anticipated expiration: 1974-07-30

Description

July so, 1957 Filed Aug. 3, 1953 P. R. CONTANT ELECTRIC CLOCK DRIVE 2 Sheets-Sheet l INVENTOR. Pefer R. Confam Attorney July 30, 1957 P. R. CONTANT ELECTRIC CLOCK DRIVE Filed Aug. .3. 1953 2 Sheets-Sheet 2 a ii 36 a 38 ts- T: z 41 IN? LLll 'l" L: l\ii d| lL LUl- Fig. 4

. INVENTOR. Pe fer R. Confant Attorney United States Patent ELECTRIC CLOCK DRIVE Peter R. Contant, Rochester, N. Y., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 3, 1953, Serial No. 371,821

3 Claims. (Cl. 74-142) The present invention pertains to mechanism for converting oscillatory movement into rotary movement, and more particularly to an electric clock drive wherein oscillatory movements of an armature are converted into rotary motion of a clock gear train driving member.

Heretofore, the driving mechanism between an oscillatable, magnetically operated armature and the rotatable driving member of a clock gear train has been subject to failure by reason of being subjected to excessively high unit area pressures. This invention obviates the concentration of high unit area pressures on the driving connection, and, hence, materially reduces the possibility of failure. Accordingly, among my objects are the provisions of a driving mechanism of the type comprising a drive pawl and ratchet arrangement including means for reducing the stress imposed on the drive pawl; the further provision of a driving mechanism wherein the drive pawl is operatively connected to an oscillatable armature through a self-aligningdrive pin connection; and the still further provision of a driving mechanism wherein the drive pawl has a relatively large contact area with the self-aligning drive pin to which it is operatively connected.

The aforementioned and other objects are accomplished in the present invention by forming a loop in one end of the wire drive pawl, which loop is received in an annular groove of the oscillatable, armature carried drive pin. Specifically, the present invention relates to an improved driving mechanism of the general type disclosed in Patent No. 2,572,989, Contant et al., in which one end of the wire drive pawl is received in a small wire loop carried by the oscillatable armature of an electric clock constructed generally according to the disclosure of Patent No. 2,642,714, Contant et al. It has been observed that the wire loop connection between the oscillatable armature and the end of the wire drive pawl does not provide a completely satisfactory driving connection inasmuch as wire drive pawls are of varying cross sections and are oftentimes subject to wear, which may result in failure. Moreover, due to the fact that the area of contact between the wire loop and the wire drive pawl in the driving mechanism of Patent No. 2,572,989, is relatively small, the unit area pressures to which this connection is subjected are extremely high.

In this invention, one end of the wire drive pawl is formed into a loop, which is received in an annular groove of a nylon drive pin. As nylon, a synthetic linear polyamide, has proven itself to be an excellent, self-lubricating, bearing material, and the area of contact between the wire drive pawl and the pin is relatively large, the tend- 'ency of failure in the driving mechanism at this connection is materially reduced. The nylon drive pin is attached to the oscillatable armature by means of a link member having a flanged opening, which receives a partially spherical head of the pin, thereby providing a selfaligning interconnection between the pin and the armature and further reducing the stress imposed on the drive pawl during armature oscillation.

The other end of the drive pawl is attached to supporting structure, and an intermediate portion thereof is spring biased so as to return the armture to its normal position when an electromagnet associated therewith is deenergized. The drive pawl engages a ratchet wheel and constitutes the means for converting oscillation of the armature into intermittent rotation of the ratchet wheel, which is then transmitted to the driving member of the clock gear train. The driving mechanism also includes a holding pawl, or a detent wire, for preventing retrograde movement of the ratchet wheel during the return stroke of the armature under spring bias.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a bottom plan view of an electric clock, with a portion of the back cut away to show the present driving mechanism.

Fig. 2 is an enlarged fragmentary view, in elevation, with certain parts cut away, taken in the direction of arrow 2 in Fig. 1, with the electromagnet deenergized.

Fig. 3 is a view similar to Fig. 2, with the electromagnet energized.

Fig. 4 is an enlarged fragmentary view, in elevation, taken in the direction of arrow 4 in Fig. 1.

Fig. 5 is a view, in perspective, of the nylon drive pin.

Fig. 6 is a view, in perspective, of the armature link in which the drive pin is self-aligning.

It is to be understood that although the instant driving mechanism is shown in conjunction with an electric clock, some features of the driving mechanism, to be described, are of general application and may be employed in diverse mechanisms where it is necessary to convert oscillatory movement into intermittent rotary movement. As aforementioned, the driving mechanism may be associated with an electric clock of the type shown in Patent No. 2,642,714, wherein a single electromagnet is provided with poles associated with a timing mechanism including a balance wheel armature which controls and is sustained in oscillation by the intermittent energization of the electromagnet. The electromagnet includes a second set of poles associated with a driving mechanism including an oscillatable index armature, which is adapted to operate the clock gear train by means of the driving mechanism of this invention.

With particular reference to Fig. 1 of the drawings, the clock construction will not be described in detail since it is not believed necessary to understand the instant invention. The clock construction may include a base plate, or frame, 10 to which an electromagnet 12 is attached. The electromagnet 12 is provided with upper and lower pole pieces, only one, 14, of which is shown in Fig. 1, the faces of which are located adjacent the periphery of a balance wheel 16. As is more fully shown and described in Patent No. 2,642,714, a switch mechanism, including a contact on the staff of the balance wheel 16, engages a contact arm, not shown, during oscillatory movement of the balance wheel 16, which switch mechanism is employed to control the intermittent energization of the winding of electromagnet 12 to thereby impart periodic magnetic impulses to the balance wheel to sustain it in oscillation.

The electromagnet 12 is also provided with a second set of upper and

lower pole pieces

18 and 20. The

pole pieces

18 and 20 extend generally parallel to one another and terminate in spaced ends adapted to impart periodic magnetic impulses to a driving armature 22.

The

pole pieces

18 and 20 are interconnected by a pair of spaced

bearing plates

24 and 26, which are staked thereto, as at '28 and 30. The driving armature 22 is drivingly connected to a worm 36. The worm 36 is I formed on a shaft 38, which is supported by a bracket 40 mounted on the base plate, or frame, 10. The worm 36 meshes with a worm wheel 42 that is drivingly connected to a clock gear train, not shown, in a manner well known in the art.

As is seen in Fig. 1, the bracket 40 is attached to the frame by means of a pillar, or post, 44. As is further seen in Fig. 1, pole piece 14 of the electromagnet 12 is attached at one end of a pillar 46 from which a bridge assembly 48 extends across the upper portion of the clock and by which the balance wheel staff, not shown, is supported for rotation. v The means for imparting rotation 'to the ratchet wheel 34 upon oscillation of the armature 22 includes a wire drive pawl 50 and a hairpin, or U-shaped holding pawl, or detent wire 52. One end of the drive pawl 50 is attached to the bridge assembly 48, and an intermediate portion of the drive pawl 50 is connected by a helically wound spring 54 to the bracket 40.

The free end of the drive pawl 50 is formed in a loop and extends through a vertical slot 56 in the bearing plate 24. The loop of the drive pawl 50 is received in an annular groove 57 of a nylon drive pin 58.

As is seen particularly in Figs. 2, 3 and 5, the drive pin 58 is formed with a partially spherical head portion 60, which is received by a flanged opening in a link 62. The partially spherical head 60 of the drive pin 58 provides a self-aligning connection for the pin during armature oscillation, and thereby minimizes stressing of the pawl 50. The link 62 is attached to the U-shaped driving armature 22 by any suitable means, not shown, such that upon oscillation of the armature 22, due to energization of the winding of electromagnet 12, lateral movement will be imparted to the drive pawl 50. As is shown in Fig. 6, the link 62 comprises ametallic member having a flat portion 63 and an angularly extending arm portion 65 provided with a flanged opening 67 for receiving the pin 58.

The holding pawl, or detent wire, 52, as aforementioned, is of substantially hairpin shape, the base of which is received in an opening in the bridge assembly 48, Fig. 4. The diverging

leg portions

64 and 66 of the holding pawl 52 are received in a vertical slot 68 of. the bearing plate 24, the slot 68 being of such a size as to prevent lateral movement of the

leg portions

64 and 66 of the holding pawl 52. As the holding pawl 52 is formed of spring wire, it will be appreciated that theleg portions armature in a counterclockwise direction, to the position shown in Fig. 3, movement will be imparted to the ratchet 'wheel 34 and the worm 36. Upon deenergization of the winding of the electromagnet 12, the spring 54 through its connection with the armature 22 by means of pawl will return the armature to its normal position, as depicted in Fig. 2.

The driving mechanism operates substantially as. follows. When the winding of electromagnet 12-is energized, the driving armature 22 will'be rotated in acounterof vertical slot 56, which is preferably formed to be only slightly larger than one tooth space of the ratchet wheel so that the ratchet wheel can only be advanced one tooth by the drive pawl when the electromagnet is energized. In Fig. 3 the drive pin 38 is shown in the position which it assumes when the electromagnet is energized. During movement of the armature 22 between the positions of Figs. 2 and 3, the partially spherical head portion of the drive pin will adjust itself to minimize the stress imposed on the drive pawl 50.

During counterclockwise rotation of the ratchet wheel 34, the leg or end portion 66 of the detent wire, or holding pawl, 52 is forced upwardly in the vertical slot 68 in the bearing plate 24 until it reaches the end of a tooth face on the ratchet wheel, at which time it will drop behind the tooth to hold the ratchet wheel against rotation in a clockwise direction. Thus, upon deenergization of the electromagnet 12, the bias of spring 54 will move the armature 22 in a clockwise direction to its normal position, Fig. 2, through the drive pawl and drive pin connection. However, movement of the ratchet wheel 34 in a clockwise direction is prevented by the holding pawl 52 in the manner aforedescribed.

From the foregoing description, it is apparent that the present invention provides mechanism for converting oscillatory movement of an armature into intermittent rotary movement of a ratchet wheel which is connected to the driving member of a clock gear train. Moreover, by forming the connection between the wire drive pawl and the drive pin in the manner disclosed herein, a substantial contact area is provided which materially reduces the stress imposed upon the drive pawl during armature oscillation. Furthermore, the self-aligning connection with the drive pawl with the armature assures contact of the driving pawl with the periphery of the ratchet wheel and also reduces the stress imposed upon the interconnection between the drive pin and the drive pawl.

.While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adapted.

What is claimed is as follows:

1. In a driving mechanism having an oscillatory driving member, means to convert the oscillatory movement of said member to intermittent rotary movement of a driven member including a ratchet wheel on said driven member, a wire arm constituting a drive pawl for said ratchet wheel, said wire arm being fixed at one end and having its other end looped, said wire arm being adapted to engage said ratchet wheel adjacent its looped end, and a self-aligning drive pin operatively connected to said driving member, said drive pin having an annular groove within which the looped end of said wire arm is received whereby movement of said driving member in one direction will cause said arm to advance said ratchet wheel.

2. The combination set forth in claim 1 wherein said drive pin has a partially spherical head portion, and wherein the interconnection between said drive pin and said driving member includes a link having one end attached to said driving member and a flanged opening adjacent the other end within which the partially spherical head of the drive pin .is received.

3. In a driving mechanism for electric clocks having an electromagnet adapted to be periodically energized 'and a driving armature mounted for oscillation in response to energization and deenergization of said electromagnet, a ratchet wheel, a wire drive pawl having a looped end, 'a driving. pin operatively connected to said armature and "having an annular groove within which the looped end of said wire drive pawl is received, said drive pawl having a portion adjacent said looped end and in engagement with said ratchet wheel so as to be actuated by movement of said-armature in one direction when said electromagnet is energizedto advance'said ratchet wheel, means operatively associated with said armature for effecting move- .rnent thereof lathe opposite direction when the electromagnet is deenergized, and means operatively associated with the ratchet wheel for preventing reverse rotation thereof wheh the armature is moved in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 126,052 Harrison Apr. 23, 1872 6 Hurley Sept. 25, 1877 Dock Feb. 5, 1907 Best Mar. 25, 1941 Mueller et a1 Nov. 24, 1942 Contant et a1 Oct. 30, 1951