US1091153A

US1091153A - Electric clock.

Info

Publication number: US1091153A
Application number: US74125713A
Authority: US
Inventors: John J Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 1913-01-10
Filing date: 1913-01-10
Publication date: 1914-03-24
Anticipated expiration: 1931-03-24

Description

J. J, MOORE. ELECTRIC CLOCK.

APPLICATION FILED JAN.10, 1913.

Patented Mar. 24, 1914 2 SHEETS-BREST 1.

JJ/Mmm J. J. MOORE.

ELECTRIC CLOCK.

APPLIOATION FILED 1.411,10, 1913.

Patented Mar. 24, 1914,

z SHEETS-SHEET 2.

www :IJ/#dora i UNITED sTATEs PATENT oEEroE.

\ JOHN J. MOORE, 'OF oHAMBEasBURG, PENNSYLVANIA.

ELECTRIC CLOCK.

` T0 all whom. it may concern Be it known that I, JoH-N J. MOORE, a citizen of the United States, residing at Chambersburg, in the county of Franklin and State of Pennsylvania, have invented new and useful Improvements in Electric Clocks, of which the following is a specification.

This invention relates 'to electric clocks adapted for use as domestic clocks, Atower clocks or the. master clocks yof systems, the main object being to provide a prime mover for operating each clock through the medium of its balance staff, the prime mover being adapted to start the clock by giving an initial impulse to the said staff, and thereafter to impart impulses thereto whenever its beat is below the normallength.

A further object is the provision of an" electric'circuit for \the said prime mover and means provided in said circuit when it is desired to give an impulse to the balance staff, the said means being controlled by the length of beat of the balance wheel staff.

A still further object is the provision of an electric striking mechanism peculiarly adapted for use in connection with the clock operating means. A Y v The invention consists in the features of construction combination and arrangement of parts, hereinafter fully described and claimed, reference being had to the accompanying drawings, in which:

Figure 1 is a front elevation; Fig. 2 is a side elevation; Fig. 3 is a transverse horizontal sectional view taken on the line 3 3 of Fig. 1: F 4 is a fragmentary sectional view of the balance staff and crown wheel showing the means for operating the latter;

Fig. is a plan view of the circuit closing governor, the balance stafi'l being shown 'in section, during the impulse beat of the staff; Fig. 6 is a similar view showing the governor in inoperative position as caused during the reverse beat of the balance staff; and, Fig. 7 is a detail, fragmentary plan view of thc contact arms of the striking mechanism and the means for mounting the same.

Referring to the drawings, and in particular to Figs. 2 and 3, 1 and 2 'designates the front and rear plates of the clock frame which-are connected by spacing fastening bolts 3. A supporting b racket`4v is secured to. the plate 2 adjacent its .lower edge by means of a bolt 5 which is mounted within Specication of Letters Patent.

Patented Mar. 24, 1914.'y

Application led January 10, 1913. Serial N o. 741,257.

a sleeve 6 o-f insulating material, the latter being disposed within an opening in the plate and serving to insulate the said bracket from the plate. In this position the bracket extends inwardly to a. point about midway of the clock frame where it is pro- Y vided with a vertically adjustable steel bearing screw 7 provided in its upper end with a recess for'the reception ed end of the vertical'balance staffl 8, the upper end of which is mounted within the recess in the lower end of a similar adjustable bearingscrew 9, which latter is mounted within a central opening in lthe crossV bar 10 whose down-bent ends 11 and 12 are secured to the plates 1 and 2 of the frame of the lower pointby means of the clamping screws 13 and 14,

respectively, the said screws being surrounded by

insulating sleeves

15 and 16 so as to insulate the cross bar from the frame plates. The usual balance wheel 17 is fixedly secured to the balance staff centrally thereof, and a hair spring 18 surrounds the upper end of the said staff, having its inner end fixed to the stalf and its outer end secured to the attaching stud 19 depending from the insulated cross bar 10. A bearing bracket 20 is attached to the rear plate 2 of the frame by means o-f the clamping screw 21 and is insulated therefrom by the collar 22 ofpnonconducting material, and extends inwardly past the balance'stafl", its end being bent laterally in front of the said staff so as to support the inner end of a horizontal arbor 23 whose outer end is pivotally mounted, as

at 24, in an opening in the front plate. rlfhis 1 arbor 23 is disposed so that its longitudinal axis intersects the axis of the balance staff, and has ixedly mounted thereon, adjacent its inner end, the crown wheel 25 provided with the beveled teeth 26 on its inner edge` An actuating pin :27, having a sleeve 28 of insulating material surrounding its horizontal portion 29, is mounted within a transverse opening 30 in the balance staff immediately below the lower 'edge of the crown wheel so that its upwardly bent, outer portion 31 is adapted to engage the straight faces 32 of the teeth 26 during the'co-ntraction movement of the hairspring or what may be termed the reverse beat of the-balance staff. A second actuating` member 33 ias its horizontal portion 34 mounted in a transverse opening 35 in the staff immedil ately above the upper 'odge of the crown staff.

wheel and is angularly disposed with respect to the first-named member 27 so that its down-bent engaging portion 36 will engage the said straight faces of the teeth 2G during the impulse beat of the balance staff caused byy expansion of the hair spring. The minute hand post 37 passes through an opening in the front plate 1 of the frame at 38 and has' its inner end pivoted, as at 38, in a bearing recess provided in the upper portion. of an upwardly bent supporting bracket 39 Whose lower end 40 is secured to the plate 1 by means of the clamping screw 41 and *is in electrical connection therewith. The minute hand operating gear wheel 42 is mounted upon the post 37 adjacent the inner face of the front plate 1 and is held in frictional engagement therewith so as to rotate the same by engagement of the spring washer 43 with a cross pin 44 extending transversely through the said post 37 with its convex face 45. An engaging lmember 46 is secured to the arbor 23 adjacent the front plate 1 and is so positioned radially with respect to the said arbor that its outwardly bent, horizontal portion 47 is adapted to enga ge the gear wheel 42 between the adjacent teeth thereof so as to impart slight movement tothe same at each rotation of the said arbor 23. A pairof vertically spaced electro-

magnets

48 and 49 are suit ably secured to the rear plate 2 of thecloek frame so that the outer ends of their

cores

50 and 51 are in magnetic connection by means of the bar 52. A disk 53 is formed on the balance staff between the balance wheel 17 and the lower end of the staff so as to rotate in a horizontal plane, and has attached to one edge thereof the medial por'- tion of a vertically extending armature plate 54, whose

end portions

55 and 56 are adapted to pass in close proximity to the inner ends of the

magnet cores

50 and 51, respectively, during oscillation of the balance A binding post 57 insulated from the bracket by the non-conducting sleeve 57a is secured to the supporting bracket 4 adjacent its outer or attached end, and is provided with an upwardly protruding contact point 58 disposed above the level of the said bracket. A circuit closing member 59. is pivoted to the bracket 4 by means of a vertical bolt 60 which extends through the cylindrical body portion thereof. 'A laterally eX- tending contact arm G2 is formed on the cylindrical body 61 of the member so as to extend outwardly over the contact point 58, which latter is locatedl in the path of hori- Zontal movement of the said arm. A pair of vertically spaced, angularly disposed actuating arms 63 and 64 are formed on the body 61 of the member 59 so as to extend inwardly therefrom. An actuating member -G5 is secured to the balance staff adjacent its lower end. The down-bent portion 66 `the crown gear 25,

of the said member is adapted to engage the operating arm 63 of the circuit closing member upon oscillation of the balance staff caused by the contraction of the hair spring 18. A second. actuating member 67 is secured to the balance staff above the firstnamed member (35 at 'i horizontal angle to .the same. The down-bent end portion 69 of the actuating member 67 is adapted to engageV the operating arm 64 of the circuit closing member upon oscillation of the balance stafl.l in its impulse beat in the direction of the arrow a in Fig. 5, as caused by the expansion of the hair spring. i A binding post 70 is attached to the front plate 1 of the clock frame adjacent its lower edge and is in electrical connection therewith. A suitable source of electric supply 71 has one of itsy electrodes 72 connected by means of a conductor 73 to the binding post 70.

The electrode 74 of the said source is connected by means of a suitable conductor 75 to the electro-magnet 48. which is connected in series with the other electro-magnet 49. The latter electro-magnet is then connected by means of a conductor 76 to the binding post 57 carried by the supporting bracket 4. It is to be understood that the hour hand sleeve 77, which is shown in Fig. 1, is connected to the minute hand gear wheel 42 by a suitable train of gears, the gear wheel 78 forming a part of this train, being the only one shown. It is to be understood that the hair spring 18 is so adjusted with relation to the actuating members and 67 on the balance sta, that the latter will always come to rest, when the electric circuit is opened for any cause, in such a position that the contact arm 62 of the circuit closing device will be in'engagement with the contact point 58. The actuating members 33 and 27, also, should be disposed out of engagement with the teeth of A when the balance staff is at rest. Thus, when the electric circuit is again closed, an initial impulse will be imparted to the balance staff due to the energization of the electro-

magnets

48 and 49, after the balance -staif has been manually oseillated to bring the actuating .member 33 into engagement with the teeth of the crown wheel 35.

In the operation 0f the time mechanism of the clock, the balance staff will pulsate to beat regularly after it has been started, as just described. The alternate expansion and contraction of' the hair spring 18 during the impulse and reverse beats o-f the balance staff will cause the

actuating members

65 and 67 to oscillate past the circuit closing member 59. As shown in Fig. 5, the balance staff is turning in the direction of the arrow a during its impulse beat, the actuating member 67 having'just engaged the operat ing arm 64 of the circuit closer so as to swing posite direction in its reverse beat as indicated by the arrow b in Fig. 6, the member 67, or rather its portion 69 will clear the arm 64. During this beat, in case the balance staff is pulsating up to its normal length of stroke, the member (i5 will engage the operating arm 63 of the circuit closer so as to swing the contact arm 62 in the direction of the arrow c out of engagement with the contact point 58, so that, when the actuating member 33 is brought into engagement with the teeth of the crown wheel with the next succeeding impulse beat of the balance staff, the circuit closer will be in open position. Just as soon as the beat of the balance staff becomes shorter than its normal length, the member 65 will fail to oscillate tar enough, during one of the reverse beats, to engage the operating arm 03 .of the -circuit closer so as to throw the contact arm G2 out of Vengagement with the contact point 58. Therefore, as the actuating member' engages the teeth of the crown wheel, during the next successive impulse beat of the balance statt, the circuit closer will be in closed position, thus permitting the current to pass from the positive pole72 of the source of electrical supply 7l through the conductor 73, binding post 70, the frontplate l of the frame, arbor 23, crown 'wheel 25, actuating member 33, and the balance statt 8 down to the bearing screw 7, whence it will pass through the bracket arm 4, the member 59 and its contact arm 62 to the contact point 58. From the contact point 58 and the binding post 57 to which it is attached, the current will pass through the conductor 5G, electro-

magnets

49 and 48 and conductor 75 back to the source 71 where it is connected to the negative pole 74. The

magnets

48 and 49 will thus be energized when the armature 54 is yin suitable proximity to the same. so

that a. renewing impulse will be imparted to the balance stati". This operation will continue as long as the battery or other suitable source of supply of electrical current 7l is in circuitwith the clock, or until the battery has become exhausted.

An important feature of the construction is the provision' of the disk 53 on the balance staff which has the armature 54 attached thereto. This renders the movement given the stati' by attraction of they armature when the magnet is energized smooth and free, witho-ut the jerk which would be caused in case4 the armature .came in direct contact with the magnets as in the case ot' a reciprocating armature.

Thus far, the time operating mechanism of the clock has been dealt with, but I will IlOW proceed with a description of the striking mechanism which is dependent upon the previously described structure.

An inwardly extending post or support 79 .formed of hard rubber,'ber or some such insulating material, is secured at its outer end to the rear plate 2 of the clock frame bv means of the clamping screw 80, and has its v inner end, which extends slightly past the Center of the frame, reduced, as at 81. A pair of relatively spaced

contact arms

82 and 83 are enlarged, as at 84 and 85 adjacent their outer ends, and-provided with angular openings in these enlarged portions for the reception of a block 86 of insulating material, which is mounted for oscillation upon' the reduced po-rtion 81 of the support 79. This block 86 serves to insulate 'the said arms effectively and to cause simultaneous operation of both arms. A clamping screw 87 is inserted into a threaded recess in the end of the reduced portion 81 of the support 79 so as to secure the block 80, with its attached conta-ct arms, in position thereupon, and which at the same time permits oscillation of the same upon the pivot thus formed. The outer end portion 88 of the arm 82 is shorter than the corresponding portion of the other arm yand is adapted to bear against the upper surface of the angular stopmember 90 carried by the support 79. A helical spring 92 surrounds the support 79 adjacent the contact arm 82 and has -one end secured to said arm and the other to the stop member 90 so as to normally main` tain the inner ends of the contact arms in their uppermost position with the portion 88 of the arm 82 in engagement with the said stop member 90. A movable postor arbor 93 has one end journaled, as at 94, in the plate 2 adjacent the support 79, and has its other end jo-.urnaled in the plate 1, as at 95. the reduced portie-n 9G at this end of the post being extended outwardly past the outer face of the plate 1. secured to the movable post 93 adjacent the end portion 89 of the Contact arm 83 and has a lateral projection 98 adapted to engage the under. edge of theiaid portion 89 of thev contact arm so as to support the

arms

82 and 83 in such a'position against the tension ot the spring 92 that the beveled projection 99 formed on the outer face ofthe arm 82 at its inner end is disposed medially below the path of movement of the operating lug 100 extending laterally from the balance statt above the disk 53. In this position, the pon tion 88 of the arm 82 is slightly spaced from' the stop member 90. An angular tripping member 101 carried by the minute hand post 37 is provided with a. lateral extension 102 adapted to engage the under edge of an in-y wardly extending tripping arm 103 carried by the movable post 93, when the minute hand `arrives at the hour mark and in so doing A lifter pin 97 is I cured to its inner lowers the lifter pin 97 to permit Lthe portion 89 of the contact arm 83 to drop and allow vthe portion 88 of the other arm to rest upon the stop member 90. When the

contact arms

82 and 83 are in this position, the beveled projection 99 on the outer end of the former is located in the path of movement of the lug 100 and is adapted to be engaged thereby to force the extremity of the arm 82 over into engagement with a laterally extending contact pin 104 passing through the outer arm 83 adjacent its extremity. An auxiliarv or releasing member 105 is provided on the'inwardly projecting portion 106 ot the minute hand post. This member com-A prises a lateral portion 107 secured to the portion 106 of the post, a longitudinally extending portion 108, and an inwardly extending finger, the latter being adapted to engage the surface of -the adjacent portion of the contact pin 104 so as to hold the

Contact arms

82 and 33 below the position inwhich the enlargement 99 is inthe path of the lug 100, thus maintaining the portion 88 ot the contact arm 82 slightly above the stop 90. In the instant the minute hand arrives at the hour mark, the finger 109 moves out of engagement with the portion 110 of the contact pin 104 so as to release. the contact arms and allow them to be thrown upward into their operative position by the action of the spring 92, the said portion 88 of the arm 82 resting upon the stop 90 in this position and preventing undue upward movement of the conta-ct arm.

The arcuate rack member 111 is pivoted to an inward extension 112 lo1 the front plate 1 by means of the pivot bolt 113. This member 111 is provided on the upper portion ot its periphery 4with a plurality of outwardly raking ratchet teeth 114, a cut-away portion or depression 115 being provided adjacent the outermost. tooth for the reception ot'. the active point 116 o1 a pawl 117 which is lixedly connected to the protruding, reduced extremity 96 of the movable post 93, as at 118, when the striking mechanism is inoperative. A plurality of downwardly raking rack teeth 119 are provided upon t-he lower, outer portion of the member 111. fl`hese teeth are adapted to be engaged by an operating member 120 which is pivoted, at 121, to a lateral arm 122 which is secured ixedly at 123 to the outwardly projecting, reduced portion 124 of a movable arbor 125 pivoted between the front and rear plates 102 of the frame, yas at 126 and 127. The member 120 is normally held in position for engagement with the said teeth by leans of a. spring 128 secured to the arm 122. An arm 129 projecting inwardly from the central portion of the arbor 125 has seend the central portion of a transversely extending armature 130 whose

end portions

131 and 132 are disposed above and 134 so as to portion or linger' ing` mechanism for the cores of a pair of electro-magnetsl 133 be attracted by the same when the magnets are energized. These electro-magnets are supported upon a transverse plate 135 secured to the frame plates at either end by means of

suitable screws

136 and 137. A downwardly curved hammer arm 138 is provided on the movable arbor 125 and is adapted tost-rike the extremity of the upper portion 140 of the striking lever 141 which is secured to a transverse arbor 142 in suitable proximity to the bell 143, its ends being pivo-tally mounted in the frame plates 1 and 2, as at 144 and 145. A stop member 146 extends inwardly from the frame plate 2 and is adapted to engage the under surface of a inger 147 carried by the said arbor 142 so as .to limit the downward movement of the main portion of the lever 141 which bearsthe striking hammer 148. A helical spring 149 encircles a portion of the movable post 89 and has one extremity attached to the plate 2 and the other extremity attached to the curved hammer 138 yto maintain the said post in such position that the armature 130 is normally spaced from the cores of the electro-

magnets

133 and 134. An inwardly extending adjuster arm 150 is formed on the arcuate member 111 adjacent its point of pivotal connection and has its extremity inbent, as at 151, for engagement with one of the active faces 152 of the step cam 153 which is iixedly secured to the hour hand therewith, the latter being movably mounted upon the minute hand post 37. The contact arm 83 which is insulated from the contact arm 82 is connected by means of a conductor 155 with the electro-magnet 134, which is in turn connected in series with the electro-magnet 133`by mea-ns of the conductor 156, and the magnet 133 is connected by means of the conductor'157 with one pole ot a suitable source of electrical supply or battery 158, Vthe opposite pole of the battery being connected by means or' the conductor 159 with the contact arm 82.

,lt is to be understood that I may utilize' the source ot supply 71 for the clock operatthel striking mechanism by connecting the electro-magnets and contact arms just described in parallel with the operating circuit.

ln the operation of the striking mechanism, it will be seen that. when the minute hand arrives approximately at the hour mark, the angular member 101 will raise the arm 103 attached to the movable post 93, thus lowering the member 97 and permitting the

Contact arms

82 and 83 to be turned upon their pivot so'that the contact pin 104 rises-into engagement with the inger 109 of the auxiliary tripping member 105 carried by the inner end sleeve 154 so as to rotate' use in connection with of the minute hand post..l This motion of the movable post causes' the pawl117 to be moved so that its engaging extremity 116 rises from the recess 115 and permits the member 111 to lgravitate into its lowermost position, the inbent extremity 151 of thearm 150 being raised into contact with one of the active faces 152 of the step cam 153. This' arm 150 determines by the extent of its upward movement, the number of ratchet teeth 154 which will be passed over by the pawl 117. When .the minute hand arrives exactly at the hour mark, the finger 109 of the auxiliary tripping device will be tliio'wn out of engagement with the portion 108 of the contact pin 104 so as-to allow the contact arms to move upwardly into their operative position, this motion being limited by engagement of the stop 90 with the portion 88 of the arm 82. At each pulsation or beat of the balance staff, thelug 100 will engage one beveled face of the enlargement 99 formed on the extremity of the contact arm 82 so as to force the said arm into engagement with the contact pin 104 of the coacting arm. At each of. these closing operations,

4the electrical circuit will be closed through the

magnets

133 and 134 so as to attract the armature 130 and thus cause the hammer 138 to strike the anvil 139 and thereby to cause the striking hammer 148 to strike the bell 143. At the same time the arm 122 is moved upwardly so as to bring the member 120 into engagement with one of the rack teeth 119. The throw of the armature arm is sufficient in length to impart movement to the member 120 necessary to force the armature member upwardly so that the extremity 116 of the pawl 117 will fall into a second notch. As the lug 100 moves out of engagement with the enlargement 99 on the Contact 82, the circuit will be broken and the armature supporting arm 129 will rise due to the action of the spring 149, thus causing the member 120 to drop to a second notch on the rack 119. Thus it will be, seenthat each pulsation of the balance staff will cause a bell stroke, and the number of teeth over which the pawl 117 passes before it drops in the recess 115 will determine the number of strokes. When the extremity 116 of the pawl 117 finally drops in the recess 115, the angular member 101 carried by the minute hand post will'be out of the path of the arm 103, thus allowing this arm to gravitate into its lowermost position and causing the lifter pin 97 to raise the portion 89 of the contact arm 83, thus forcing the contact arms into their lowermost inoperative position against the action of the spring 92, where they remain until an hour has elapsed and it is time for a repetition of the striking operation just described.

Vhat is claimed is 1. In a clock of ther class described, the- )alance stall' journaled between said cross plates, of a supporting bracket carried by one of said plates and insulated therefrom, an insulated cross bar connecting said frame lates in spaced relation to said brackets, a bar and bracket and being in electrical con- 7o nectio-n therewith, an armature carried by said balance staH, an electro-magnet attached to the frame in suitable proximity to the path of movement of said armature, a contact point attached to said bracket and insulated therefrom, electrical connection between the said contact point and electromagnet, a source of electrical supply connected with the electro-magnets and one of the frame plates, a circuit closer pivoted to said bracket and having a contact arm enlgageablewith the insulated contact point,

means for electrically connecting said balance staff with the frame plate to which the source of electrical supply is connected during the impulse beat of the balance staff, and means provided on the balance staff for actuating the circuit closer during the impulse beat of the balance staif to throw the contact arm carried by the circuit closer onto said contact point.

2. In a clock of the class described, the combination with a pair of spaced frame plates, of a supporting bracket carried by one of said plates' and insulated therefrom, an insulated cross bar connecting said frame plates in spaced relation to said brackets, a balance staff journaled between said cross bar and bracket and being in electrical connection therewith, an armature carried by said balance staff, an electro-magnet attached to the frame in suitable proximity to the path of movement of said armature, a contact point attached to said bracket and insulated therefrom, electrical connection between the said contact point and electromagnet, a source of electrical supply connected with the electro-magnets and one of the frame plates, a circuit closer pivoted to said bracket and having a contact arm engageable with the insulated contactvpoint, means for electrically connecting said balance staff with the frame plate to which the source of electrical supply is connected during the impulse beat of the balance staff, means provided on the balance staif for acl tuating the circuit closer during the impulse beat of the balance staiil to throw the con-- tact arm carried by thecircuit closer onto said contact point, and means provided upon the balance staff for actuating the circuit closer so as to throw the contact arm out of engagement with the contact point during/ each reverse beat of the balance stal-l when the beat is normal in length, the latternamed actuating means being inoperative when the beat of the balance staff is below normal length.

3. In a clock of the class described, the

combination with a pair of spaced frame plates, of a supporting bracket carried by one of said plates and insulated therefrom, an insulated cross bar connecting said frame plates in spaced relation to said brackets, a balance staff journaled between said cross bar and bracket and being in electrical connection therewith, an armature carried by -said balance sta, an electro-magnet atbeat of the balance staff to throw the Contact arm carriedby the circuit ycloser onto said Contact point, a bearing bracket attached to the frame plate opposite to the one to which the source of electrical supply is connected,

\ the said bracket being insulated from the plate to which it is attached, an arbor journaled between said bracket and the plate to which the source of supply is connected, said arbor being in electrical connection with the last-named plate, a crown wheel iiXedly attached to said arbor, an actuating member carried by the balance staff in electrical connection therewith and engageable with the said crown wheel during the impulse beat of the balance staff to cause operation of the same, a second actuating member insulated from the said balance staf and engageable with Jthe crown wheel at a` point diametrically opposite the first-named actuating member to cause operation thereof during the reverse beat of the balance staff, and means for operatively connecting said arbor with the time mechanism ofthe clock.

4. In a clock of the class described, the combination with a pair of spaced frame plates, of a supporting bracket carried by one of said plates and insulated therefrom, an insulated `cross bar connecting said frame plates in spaced relation to said brackets, a balance stafl journaled between said cross bar and the bracket and being in electrical connection therewith, an armature carried by said balance staff, an electro-magnet attached to the frame in suitable proximity to the path of movement of said armature, a contact point attached to said bracket and insulated therefrom, electrical connection between the said contact point and electromagnet, a source of electrical supply connected with the electro-magnets and one of the frame plates, a circuit closer pivoted to said bracket and having a contact arm engageable with the insulated contact point, and means provided on the balance staff for actuating the circuit. closer during the impulse beat of the balance staff to throw the contact .arm carried by t-he circuit closer onto said Contact point, and means provided upon `the balance staff for actuating the circuit the contact arm'out of engagement with thecontact point during' closer so as to throw each reverse beat of the balance stan? when the beat is normal in length, the last-named actuating means being inoperative when the beat of the balance staff is below normal length. v

5. In a `clock of the class described, the

combination with a frame, of a balance staff journaled therein, an armature carried by said staff, an electro-magnet attached to the frame and disposed in suitable proximity to the path ofmovement of said armature, a

Contact point mounted upon the frame and insulated therefrom, electrical connection be tween the said contact point and one terminal of the electro-magnet, a source of electrical supply having one terminal connected with the electro-magnet, means for connecting the other terminal of the source electrically with the balance sta'l during each impulse beat of the latter, a circuit-closing member pivoted to the frame fo-r swinging movementin a plane disposed at right angles to the axis of the balance'staff and having a contact arm engageable with the said contact point, a pair of angularly and longitudinally spaced arms extending laterally from the said contact member, an actuating member provided upon the balance staff for engagement with one of the said arms of the circuit-closing member duringthe impulse beat of the balance staff to operate the circuit-closing member so as to move its contact arm into engagement with the said contact point, and a second actuating member carried by the balance staff and adapted for engagement with the other arm of the circuitclosing member during the reverse beat of the staff when of normal length to operate the circuit-closer and move its contact armout of engagement with the contact point.

In testimony whereof I aiiiX my signature in presence of two witnesses.

ARTHUR W. GILLAN, O. M. ORB.