US904001A - Electric secondary clock. - Google Patents

Description

H. B. MOGABB.

ELECTRIC SECONDARY CLOCK. APPIIJIGATION FILED NOV. 12, 1000.

. Patented Nov. 17, 1908.

UNITED STATES PATENT orricn.

HORACE B. McOABE, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO JOSEPH F. GOCHRAN,

OF CHICAGO, ILLINOIS.

ELECTRIC SECONDARY oLooK.

Specification of Letters Patent.

Patented Nov. 17, 1908 Application filed November 12, -19t)6. Serial No. 342,933.

Illinois, have invented certain new and useful Improvements in. Electric Sec'ondam Clocks, of'which the following is a full, clear, and exact specification.

Theinvention relates to improved mechanism for operating electric clocks and particularly to what are known as secondary clocks which are connected in a circuit controlled by a primary clock. I

The primary object of the invention isv to provide "an ii'nproved ratchet mechanism adapted to transform the reciprocatingor vibrating movement of an armature into the rotarv movement required to drive the clock hands. which is simple, cheap and absolutely accurate in its operation.

To the attanimentof these ends andthe accomphsln'nent of other new and useful objects, as will appear, the invention consists in the features of novelty in the construction, combination and arrangement ofthe various .parts, hereinafter more fully described and claimed and shown in the accompanying drawings, illustrating an exemplificatio'n of this inventiomand in'whicl1:.-

Figure 1 is rear elevation of a clock movement embodying the invention, the limits of movement of the operative parts being shown in dotted lines. .Fig. 2 is a broken detail view ofthe pawl which engagesthe teeth on the ratchet wheel. Fig. 3 is a broken plan view of the lower supporting frame work, This view shows the means employed in pivotingthe member to which the armature is attached, Theview} also shows the metal core of the magnet adjacent to the pivoted member in :horiZontal section, as

well as horizontal section of the upright arm on the pivoted member to whlch the driving pawl is attached. Fig. d is a vertical sectional view on line 44, Fig. 3.- Figs. 5 and (3 are modified views of driving pawls and modified views of their cooperating locking members.

In clocks of this character it is customary to provide a number of them in a single circuitcontrolled by means of one primary clock. The common manner of operating the secondary clocks is-to provide mechanism whereby the primarycloek closes the circuit at convei'iient intervals. In the present device provision is made for the operation of the mechanism in secondary clock at intervals of one minute. The ratchet wheel 1 is journalcd on a rotating shaft designed to. carry the minute hand. v

2 is the main frame provided with convenient means, as for example, screw holes L, for attachment to, the clock casing.

3 is an upright support attached to frame 2. and serves as'one of the supports for sustaining the journal on which ratchet wheel 1 is mounted. I v 4 and5 are common form of electro magnets supported on frame 2 by having their metal cores and 5 extending into frame 2 (see Figs. l and 3). hen the primary clock closes the circuit magnets l and 5 become energized and attract armature 6 which is pivotally mounted adjacent to the lower ends of the magnet cores 4 ando Frame 2 is provided with branch members 2 and 2 for holding adjustable pivots 7 and 8. Ar mature 6 is adjustably secured to member 9 which is mounted to rock on pivots 7 and 8.. Pivots 7 andS maybe adjustably secured in and '15. Pivoted rocking member 9 is provided with an upwardly. extending arm.9

moves in the direction indicated by the. ar- Y row and it Will'be noted that teeth 11 are so inclined to the circumference of the wheel that the driving ratchet is effective to'move them only in the diiection indicated by the arrow. The driving pawl 10 is provided with suitable means, as branch 10, for taking into teeth 11 and this pawl is allowed to rest normally. on top of'the wheel in contact with the teeth with which it is held in constant engagement by gravity.

' By referring to Fig. 1 it will be seen that the position of the armature indicated by full lines is out of contact with the magnet. IVhen thecir'cuit is closed by the primary clock and the magnet energized the armature is thrown upwardly into contact witlrthe 80 frame 2 by means of suitable set screws 14 i magnet cores which rocks member 9 and upwardly extending arm 9 in the manner indicated in dotted lines. will be seen, causesthe withdrawal of driving pawl which movement of the pawl is in the direction opposite to the movement of wheel 1 as indicated by the arrow. Ar-

- mature 6 is provided with the weight memher 6 'which contains sufficient material to cause the armature to move downwardly away from the magnet cores when the current is broken by the primary clock. The

downward movement of armature 6 it will be seen again restores member 9 and upright member 9 to normal position as indicated in the illustration, which movement also operates driving pawl 10 which, in turn, 1n engaging with one of the teeth 11 causes wheel 1 to rotate in the direction ofthe arrow one space or the distance between two of the adjacent teeth. In order that the movement of pawl 10 may be adjusted in relation to armaturee provision is made for varying the relation between armature 6 and pivoted member 9 and member 9 is provided on the lower surface with the small. depend-,'

ing lug or support 9 and the adjustable support 12. The member 12 is screw threaded into member 9. 6 is held in contact with 9"- and 12 by means ofsuitable adjusting screw as 13 passing therethrough and threaded into member In order that the armature 6.may not become too widely separated from the magnet pole 4" pole contact member 16 having angular branch 16' is provided and the outer end of armature 6 is depressed at an angle to correspond with the angular branch 16*. The member 6 which is attached to weight (l may also be employed in order that the armature may be provided with a surface to correspond with the surface of pole member 1 16 and to keep the armature from direct co ntact with ma et cores. This arrangement of the parts, it will be seen, causes members 16 and 6 to move more or less longitudinally with reference to each other when the ari-natureis rocked which enables them to retain about the same lateral distance be-- tween each other as do the armature 6 an the pole 5 In a clock movement of this character the minute hand, which is carried directly by shaft supporting ratchet wheel 1 is ordinarily of metal and several inches in length. To overcome this weight it is common to put a counter balance on wheel 1 or to extend the minute hand rearward of its point of attachment to the shaft andplace the'counterweight thereon. This adds weight to the parts, and one of the difliculties heretofore experienced has been due to the fact that the inertia of the mechanism when moved a space by the driving pawl has bad This movement, it

a tendency to overrun or move more than a single space at each closing of the circuit.

Excessive jarring of the movements of such clocks, due to vibrations of buildings, may in some cases also cause the movementto overrun when the hands are in certain favorable positions. Such jars or vibrations imparted to the movement may also cause the mechanism to be carried in the opposite di-- rection. To prevent the possibility of any such inaccuracies in the. movement the and the auxiliary ratchet' stop l9 are progravity pawl 17, the driving pawl lock 18 r vided. The upright member 20, supporting pawl 17 and angular locking surface 18 may be conveniently attached to upright member '80 long as the armature remains in its de-' pressed position and that this position of the pawl will lock the wheel 1 against further advance motion until the movement of the armature releases the pawl by withdrawing it. When thecircuit is closed and the driving pawl 10 is withdrawn in the manner heretofore described it will be seen that'the locking efiect of pawl 10 is released and during the interval between the withdrawal of the pawl and the breaking of the circuit the wheel 1 will again be free to rotate in a forward direction. To supply an auxiliary lock during this interval the member 19 is provided. This member may be attached to upright arm 9? or to any of the parts operated by the armature and should be so positioned that when driving pawl 10- is in looking position the engaging end of lock the mechanism has withdrawn pawl 10 from locking position auxiliary lock 19 should be brought into operative position which will cause it to contact with the periphery of the wheel between two adjacent teeth;

In Figs. 5 and 6 modifications of driving pawl 10 are shown, also modifications in construction and arrangement of mechanism for 19 should not contact with teeth ll but when locking the driving pawl in the normal position to prevent overrunning of ratchet wheel,

as above described. In Fig. 5 driving pawl is designated by numeral 21, the locking member by 22 and its beveled engaging sur-' face by 23. In Fig. 6 pawl 21 is of the same formas shown in Fig. 5. 21 is shown in conjunction with a locking member of cylindrical form which may be a pin or rod supported in any desired manner.

In order that the invention might be fully the combination with a toothed wheel and its reciprocating actuating pawl, said actuating pawl being provided withanQengaging end projecting transversely outside the plane of ber for the-actuating pawl having an engaging surface outside of the'plaue of the wheel.

.3. In a device of the character described, the combination with a frame, of magnetic cores mounted thereon, a yoke joining said cores at one end thereof, a movable armature at the other end of said cores, a shaft journaled in said frame and disposed transversely between said yoke and said armature, and means for transmittin the movement of said armature to said sha t.'

4. In a device of the character described, the con'ihinatiou with a frame, of an electro magnet having cores passing through said frame, coils on said cores on one side of the said frame, a movable armature in the magnetic field of'the cores on the reverse side of said frame, an upwardly extending branch on said frame, anarbor or shaft carrying a toothed wheel journaled therein, a pawl in engagement with the wheel, and means for actuating the pawl from the said armature.

5. In a device of the character described, the combination with a main frame, of an electro-magnet secured to the main frame, an upright branch onthe main frame, a toothed 'wheel carried thereby, a vertically extending rocking member pivotally secured to the main frame at its lower extremity, a pawl carried near the upper extremity thereof and having an engaging portion in contact with said toothed wheel, an armature cooperating with the said electro-maguet and adj-ustably secured to the pivotedrocking member at the lower extremity thereof, a member secured I to the upper extremity of the said upright branch and provided with an angular surface adapted to cooperate with the pawl on the said pivoted rockin member and a gravity pawl carried by t e member on the upright branch and adapted to prevent a reverse movement of the toothed wheel.

.6. In a device of the character described, the combination with'a main frame, of an electro-magnet secured to the main frame, an upright branchon the mainframe, a toothed wheel carried thereby, a vertically extending rocking member pivotally secured to the main frame at its lower extremity, a pawl carried near the upper extremity thereof and having an engaging portionin contact with said toothed wheel, and an armature cooperating with the said electro-magnet and adjustably secured to the said pivoted rocking member at the lower extremity thereof.

7. In a device of the character described, the combination of a toothed wheel, a pivoted member, a driving pawl carried by said pivoted member and adapted to'engage said toothed wheel, engaging means adapted to force said pawl into contact with said toothed wheel, and auxiliary locking means mounted on said pivoted member and adapted to contact with said toothed wheel when said driving pawl has been withdrawn from its engaging means bysaid pivoted member.

. 8. In a device of the character described,

the combination with a frame, an electromagnet mounted thereon, a pivoted member, an armature secured thereto and extendmg into the field of the said magnet, and means

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