US3013196A

US3013196A - Chronometric governor

Info

Publication number: US3013196A
Application number: US809521A
Authority: US
Inventors: Arthur W Haydon
Original assignee: Consolidated Electronics Industries Corp
Current assignee: Consolidated Electronics Industries Corp
Priority date: 1959-04-28
Filing date: 1959-04-28
Publication date: 1961-12-12
Anticipated expiration: 1978-12-12

Description

Dec. 12, 1961 A. w. HAYDoN cHRoNoMETRIC GOVERNOR 4 Sheets-Sheet 1 Filed April 28. 1959 INVENTOR Arthur W.Hoydon ev M ATTOR EYS Dec. 12, 1961 A. w. HAYDoN CHRONOMETRIC GOVERNOR 4 Sheets-Sheet 2 Filed April 28. 1959 n 1 0%. Wwf OG MH, M ww m Nr IMMA .el r AY Dec. 12, 1961 A. w. HAYDON 3,013,196

CHRONOMETRIC GOVERNOR Filed April 28. 1959 4 Sheets-Sheet S5 ki. Arthur W HGydOn Dec. 12, 1961 A. w. HAYDON 3,013,196

CHRONOMETRIC GOVERNOR TTORNEY United States Patent Otice 3,013,196 Patented Dec. 12, 1961 3,013,196 CHRONMETRIC GGVERNGR Arthur W. Haydon, Milford, Conn., assigner to Consoiidated Electronics Industries Corp., Waterbury, Conn., a corporation of Delaware Filed Apr. 28, 1959, Ser. No. 809,521 23 Claims.. (Cl. 318311) The present invention relates to motor speed governor devices, and more particularly to specific improvements in so-oalled chronometric governors of the general type described and claimed in the Arthur W. Haydon United States Patent No. 2,523,298.

In the motor speed governor device of the abovementioned A. W. Haydon patent, the speed of operation of an electric motor is governed by connecting t-he motor to a power supply tending to drive the motor at a speed greater than desired, and connecting and disconnecting the power source periodically, in accordance with the oper-ations of a constant speed device and the motor, whereby the average speed of the motor is controlled with substantial precision regardless of substantial variations in load, source voltage, etc. An important principle of the Haydon patent resides in the provision of a motor-governor device in which a power supply circuit is opened periodically at instants determined by the travel of the motor, -and in which the circuit is subsequently closed at predetermined instants determined by the operation of a constant speed device such as a hair spring, balance wheel combinations. The device of the present invention incorporates the principle of the Haydon patent before referred to, but constitutes a specific departure therefrom, particularly in respect of the form of the constant speed means utilized to govern the instants of closure of the power circuit.

One of the specific features of the invention resides in the pro-vision of a chronometric governor device of the type having a pair of switch contacts arranged to be opened in accordance with the instantaneous rotation of a motor rotor and having a constant speed device capable of storing energy and of utilizing the stored energy to apply restraining force upon the contacts in a manner to permit or effect closure of the contacts at predetermined instants in the cyclical periods of operation of the constant speed device. In one form of the invention, 4the constant speed device comprises a balance wheel and a hair spring arranged in 4a novel manner such that the variable stress in the hair spring rst restrains one of the contacts to prevent closure thereof and then releases it to effect contact closure at the desired instant. In another form of the invention, the constant speed device comprises means, such as a pendulum, which accumulates energy upon displacement from a neutral position and which is arranged in a manner such that the accumulated energy is utilized first to restrain the contacts and later to release them to effect contract closure in the desired manner.

Advantageously, though not necessarily, the motorgovernor unit incorporates an eccentric commutator coacting with a pair of brushes and arranged to move the brushes from side to side during rotations of the motor rotor. The constant speed device is arranged to interfere with the oscillatory or side-toside movement of the brushes so that once during each half cycle of operation of the constant speed device, and at an instant determined by the instantaneous position of the motor, the commutator moves out of contact with one brush. The contact is re-established at a predetermined instant in t-he half cycle, when the lstress in the hair spring diminishes to a point where it can no longer restrain the brush. Alternatively, a pair of movable, normally engaged contact members may be oscillated from side to side, in accordance with operations of the motor, by means of a suitable cam driven by the motor shaft. Periodic interference with the oscillatory movement of the contacts, by the constant speed device, causes the motor to drive one of the contacts out of engagement with the other until, at a lixed instant in the constant speed cycle, the other contact is released.

Under normal operating conditions, the motor of a motor-governor unit of the type herein referred to tends to operate faster than the desired, predetermined speed. Thus, once during each half cycle of operation of the constant speed device, the motor circuit will be opened at an instant determined by the travel of the motor and later closed at an instant determined by the operation of the constant speed device. The motor is thereby caused alternately to accelerate and decelerate to speeds above and below the predetermined speed, in such a manner that the average speed of motor oper-ation may be maintained with great precision substantially at the desired, predetermined speed.

For a better understanding of the invention, reference should be made to the following detailed description and to the accompanying drawings, in which:

FIG. l is a simplified, perspective representation of a motor-governo-r unit incorporating features of the invention;

FIG. 2 is a cross-sectional view of a slightly modified form of the motor-.governor unit of FIG. l;

FIG. 3 is an enlarged, fragmentary illustration of details of the device of FIG. 2;

FIGS. 4-8 are simplified representations illustrating the sequence of operation of the devices of FIGS. 1 and 2;

FIG. 9 is a simplified representation of a further modilication of the motor-governor unit of the invention;

FIG. l0 is a front elevation of yet Ianother modification of the invention, utilizing a pendulum as a constant speed device;

FIG. ll is a side elevation of the device of FIG. 10; and

FIGS. 12-15a are simplified representations illustrating the sequence of operation of the device of FIG. 10.

Referring now to the drawings, and initially to FIG. 1 thereof, the numeral 10 designates the rotor of an electric motor which, in itself, may be of a conventional type. The rotor 10 is supported for rotation on a shaft 11,

which carries a commutator 12. A pair of brushes 13, Y

14 engage the commutator 12 near their upper ends and are mounted at their lower ends on a base 15. The

brushes

13, 14 are connected to a suitable source 16 of electrical power which, by definition, is suiiiciently large to drive the rotor 1t) at a speed greater than desired, under all normal operating conditions. The commutator 12 is connected in an appropriate manner to the coils 17 of the rotor, whereby the rotor may be energized and caused to rotate in a well known manner.

Mounted above the rotor shaft 11, in suitable frame means (not shown) are spaced

bearings

18, 19, which journal a balance wheel shaft 20, The shaft 2u, in turn, mounts a balance wheel 21 and a collar Z2. A hair spring 23 has one end secured to the collar 22 and has its other end anchored in a manner to be described in more detail, whereby the balance wheel 21 is conditioned for Oscillation at a fixed period or frequency determined by such factors as rotating inertia and hair spring characteristics.

As one of the important features of the invention, the outer end of the hair spring 23, identified by the numeral 24, is anchored to an impulse lever 25 mounted for limited pivotal movement by means of

bearings

26, 27. In the illustrated device, the

bearings

26, 27 are located immediately below the

bearings

18, 19 respectively,

'illustrated schematically in FIGS. 4-8.

whereby the pivoting aXis of the impulse lever 25 is parallel to but slightly below the axis oi the balance wheel shaft 2Q. ideally, the

bearings

26 and 27 would be coaxial with the

lhearings

13 and 19, but this would complicate the supporting Structure, and satisfactory results have been `obtained from the arrangement shown. Adjacent one end of the impulse lever 25 are spaced banking pins 2S, 29, which are lmounted on the frame and are spaced on opposite sides oi the impulse lever to limit pivoting movement thereof in either direction.

When the balance wheel Z1 is set in motion, the lever 25 will move against `one of the banking pins while the rotating inertia of the wheel 21 is transferred to the hair spring 23. When the wheel reverses direction, and the energy of the spring is transferred back to the balance wheel, the impulse lever 25 will be caused to shift from one banking pin to the other, during the interval immediately preceding the start of the retransfer of energy from the wheel to the spring.

in accordance with the invention, the impulse lever 25 has an active region 3i) which lies between

opper end portions

31, 32 of the

brush members

13, 14 respectively. The relationship of the

brushes

13, 14 and impulse lever 2S is such that, when the balance wheel system is at rest and the eccentric commutator 12 is oriented to point upwardly, as shown in FlG. l, or downwardly, the

upper portions

31, 32 of the brushes are spaced from the active portion 3i) of the impulse lever.

When the rotor 1u is energized and beffns to rotate, the

brushes

13, 14, which press resiliently toward the commutator 12 tend to oscillate from side to side, following the rotations of the commutator. The brushes are thus caused alternatively to strike the impulse lever, first from one side and then from the other. Energy impulses are thus imparted to the balance wheel system, through the hair spring 23, `and the balance wheel is set into motion at its natural frequency.

When the rotor 1i) accelerates to a speed near the desired, predetermined speed, the balance wheel system begins to govern the speed of the motor in the manner Thus, when the commutator 12 is in the position shown in FlG. 4, the

rushes

13, 14 are displaced to the left and, at the same time, the balance wheel 21 is rotating in a clockwise direction, transferring energy to ti e hair spring 23, which holds the impulse lever 2S against the banking pin 28. Advantageously, the relationship between the active portion 3? ot the impulse lover, the

brushes

13, 14 and the cam 12 is such that, when the brushes are displaced to the left and the impulse lever is against the left hand banking pin 28, the upper portion 31 of the left hand brush is spaced slightly from the active portion 30 of the impulse lever.

Rotation of the eccentric commutator 12 in, for example, a clockwise direction, to a position as shown in FIG. 5, allows the left hand brush 13 to move slightly to the right, against the portion 3d of the impulse lever. At this time, considerable energy is stored in the hair spring 23, so that the force of the hair spring on the impulse lever 25 is greater than the resilient force of the brush 13 acting on the lever in the opposite direction. Accordingly, as the commutator 12 continues to rotate, as to the position shown in FiG. 6, the brush 13 1s held in a. displaced position by the impulse lever 25 and the motor driven commutator 12 rotates out of contact with the brush. The motor circuit is thereby broken and the motor begins to decelerate.

When the balance wheel 21 begins to rotate in the opposite or counterclockwise direction, energy is transferred from the hair spring 23 back to the balance wheel and, eventually, the spring force of the brush 11.3 overcomes the diminished spring force applied to the impusle lever 25 by the hair spring. At this time, the impulse lever is urged toward the right hand banking pin 29, substantially as indicated in FGS. 6a, 7. This permits the brush 13 to re-establish Contact with the coinmutator 12, so that the motor circuit is again closed and the motor begins to accelerate.

Prior to the instant in which the impulse lever 25 moves toward the opposite banking pin 29, the right hand brush 14 is displaced to the right y the eccentric commutator 12, substantially as indicated in FIG. 7. Accordingly, as the balance wheel 21 continues to rotate in a counterclockwise direction, the impulse lever is carried into contact with the banking pin 29, whereupon begins a transfer of energy from the rotating balance wheel to the hair spring 23.

During the following half cycle of rotation of the commutator 12, the sequence of operations is substantially as indicated in FIGS. 4-8. However, the parte yare moving in an opposite direction, as lwil he readily understood.

When the device is in continued operation, with the rotor 10 rotating at a speed near a desired predetermined speed, the motor circuit will be interrupted once during each half cycle ci rotor rotation, at an instant determined by the instantaneous position of the motor. At a later time in the same halt cycle, the motor circuit will again be closed, at an instant determined solely by the operation of the balance Wheel system. Accordingly, it the motor is operating under conditions of light load and/ or high source voltage, the motor will tend to accelerate rapidly above the predetermined speed, and the motor circuit will open at an early point in the half cycle of operation. And, since the closing of the circuit takes place at a fixed time in the cycle, the motor circuit .fill be closed for a relatively short portion of the half cycle period. Likewise, when the motor is operating under heavy load rand/or lower source voltage (but still tending to run at a speed faster than desired) the instant of motor circuit opening will take place shortly before the Xed instant of circuit closing determined by the constant speed device. Accordingly, during each half cycle of operation of the constant speed device, the motor will be caused to accelerate to a speed slightly above the desired speed and then to decelerate to a speed slightly below the desired speed, to the end that the average speed of rotation of the motor in continued operation is regulated with great precision at the desired, predetermined speed.

During operation of the motor-governor unit, energy is imparted periodically to the balance wheel system, in uniformly measured impulses, so that the balance wheel system, once started, remains in operation with a suostantially xed amplitude of movement and thereto-re a highly accurate period. Thus, when the brush 13 is held in a displaced position by the impulse lever 25, as illustrated in FiG. 6, the brush has a iixed reference to the axis or" the commutator 12. When the brush is subsequently released, as shown in FIG. 6a, it moves through a xed distance, into contact with a portion 12a of the eccentric commutator, the portion 12a having a uniform radius. During the interval in which the brush 13 moves from the FIG. 6 position to the FlG. 7 position, it acts upon the impulse lever 25 and imparts thereto an energy impulse or predetermined magnitude. And, as will be readily understood, such energy impulse will be uniform on all occasions. Likewise, energy impulses imparted to the lever 25 by the brush 14 during alternate halt cycles of operation will be of a highly uniform nature.

Although the motor governor unit of the instant invention incorporates the fundamental principles of the Arthur W. Haydon United States Patent No. 2,523,298, the new unit differs therefrom in certain significant respects. rlihus, in the operation of the new device, the brush 13 is pushed to its extreme position, shown in PEG. 4, by the comrnutator 12 before the impulse lever hits the banking pin 20o. The hair spring torque builds up as the balance wheel rotates clockwise, and the force ot the impulse lever 25 against the banking pin 2S 'no longer equals the brush spring pressure.

becomes greater than the brush spring force before brush spring 13 is released by the commutator and comes in contact with the impulse lever 25. As the balance wheel continues on its path to maximum excursion, energy is stored in the hair spring, but no energy is consumed in holding brush 13, even after it rests against the active portion 30 of the impulse lever 2S, because no motion results.

As the balance wheel returns in a counterclockwise direction, the static energy of the hair spring is converted into kinetic energy of rotation of the balance wheel until a point is reached where the hair spring torque At this point, energy is delivered from the brush, through the impulse lever 25, to the hair spring. The brush moves over until it closes .the motor circuit by touching the commutator at 12a FIG. 7.

It will be noted, therefore, that no energy is taken out of the balance system in determining the instant of closure of the motor circuit.

This is in contrast to my earlier invention, in that the earlier invention involved the use of an impulse pin engaging a fork in the end of a lever, and energy was taken from the balance wheel system to initiate motion of the lever, which in turn released the contacts and allowed them to close, whereupon a driving pulse was delivered back through the lever to continue oscillation of the balance wheel.

Thus, in the prior system, the magnetic detents comparable to those of FIG. 3 were adjusted to have a holding force greater than the brush spring force, and the difference had to be overcome by energy from the balance wheel hair spring system in order to.trigger the action. In contrast, in the present invention, the detent magnets are adjusted to have a holding force less than the brush spring force, so the system automatically triggers as soon as the hair spring torque diminishes to a value below the diiierence of the first two.

It is important, for the sake of accurate timekeeping, to avoid extraneous forces being applied to the balance wheel system. `Even the slight amount of energy taken out of the balance wheel system makes it deviate from true simple harmonic motion. Therefore, this new system, which requires no energy for triggering, has an important advantage over my prior system.

A second improvement over my prior system is that the entire balance wheel system andthe impulse lever 25 are freely pivoting in the area between the banking pins 28 and 29. Thus they offer practically no resistance to closure of the motor circuit when the current is turned oi and the mechanism comes to a stop. Thus the motor will start reliably when the current is again turned on, and the balance wheel will start oscillating readily.

In my prior System, which had its hair spring anchored in a post in the frame, the brushes had to be adjusted with sutcient tension to deliect the balance wheel slightly oit center from its neutral position (as determined by the hair spring) in order for the motor circuit to be closed when the mechanism stopped. Thus this system is more reliably self-starting, and the brush adjustment is less critical.

In the form of the invention illustrated in FIG. 1, the active portion 39 or" the impulse lever 25 lies in front of both the balance wheel 21 and the hair spring 23. In the slightly modiiied arrangement of FIG. 2, an impulse lever 40 has an active portion 41 arranged to lie between the balance wheel 42 and hair spring 43. The form of the invention shown in FIG. 2 is otherwise substantially the salme as that shown in FIG. 1 and requires no further description. ever, that, in a commercial embodiment of the invention it may be advantageous to incorporate one or more features of the inventions described in the `co-pending applications of A. W. Haydon, Ser. No. 721,795, tiled March 17, 1958, for Electric Motor and/or A. W.

It is appropriate to note, how- 6 Haydon et al., Ser. No. 721,706, tiled March 17, 1958, for Motor Speed Governor Unit For Cordless Clocks And The Like.

In the modified arrangement illustrated in FIG. 3, an impulse lever 50 is limited in its side-to-side movement by banking pin assemblies 51, 52, which include magnetic means to assist in retaining the impulse lever in its operative limit positions. In the illustrated arrangement, the banking pin assemblies comprise

brackets

53, 54 mounted on a suitable frame (not shown) and threadedly engaging screws 55-58. One screw of each assembly (screws 55, 56) is advantageously formed of non-magnetic material and is preadjusted in its bracket to engage the impulse lever 50` and retain it in a desired limit position. The other screw (57, 58) of each assembly is formed of magnetic material and is so adjusted with respect to the non-magnetic screw of the assembly as to exert a limited magnetic force upon the impulse lever 50, when the lever is in a limit position. The attracting force exerted by the

magnetic screws

57, 58, is, ofcourse, less than the force exerted by the resilient brush or contact members, so that the lever 50 may be dislodged from the banking pin assemblies by such members. In addition, as the impulse lever moves away from the magnetic restraining means, the restraining force diminishes in accordance with the square of the separation. At the same time, the resilient force of the brush or contact member acting on the lever diminishes linearly with displacement. The arrangement is such as to provide an advantageous, positive detent action. Where desired, the magnetic detent means may be provided by utilizing magnetic bleeder elements associated with the stator of the governed motor, substantially as set forth in the co-pending application of Arthur W. Haydon et al., before mentioned.

The purpose of the described magnetic detent action is to reduce the force required from the hair spring to restrain the brushes so that the motor circuit may be more readily held open by the action of the hair spring and balance wheel. This has ytwo advantageous resultsiirst, it increases the range of control of the governor, and, second, it brings the driving pulses received from the brushes more nearly in phase with the swing of the balance wheel, thereby making them less disturb-ing to the sinusoidal motion of the balance wheel, which is essential to good timekeeping.

In the form of the invention illustrated in FIG. 9, the motor circuit includes a pair of resilient contact members 60, 61 having

contact pads

62, 63 at their upper ends. The contact members 60, 61 are arranged so that the

pads

62, 63 are normally engaged, to complete the motor circuit, and the members are adapted to be oscillated back and forth in unison by a motor driven cam 64. An impulse lever 65, associated with a balance wheel system and having anchored thereto a hair spring 66 is arranged to hold a previously displaced contact member in a displaced position, during continued rotation of the motor driven cam 64, to effect separation of the

contact pads

62, 63, when the cam 64 displaces the opposite, unrestrained contact member. The arrangement is similar to that described and claimed in the A. W. Haydon Reissue Patent No. Re. 24,310. However, retention or displaced contact members is eiiected through the application thereto of force derived from energy stored in the balance wheel system, rather than by means of a balance wheelactuated cam as set forth in the reissue patent.

In the -form of the invention illustrated in FIGS. 10 and 11, the constant speed device comprises a pendulum, rather than a balance wheel, and retention of displaced brush or contact members is eiected by the application of force derived from energy stored in the swinging pendulum. Thus, the apparatus comprises the base supported on adjustable legs -111 arranged in tripod fashion and mounting a vertical frame plate 112. The frame plate 112 mounts a bracket 113 for journalling a motor rotor 114, and also mounts a pair of

resilient brush members

115, 116 arranged to engage an eccentric commutator 117 carried by the rotor 1155. Advantageously, the rotor commutator, brushes, etc., may be of the general design described and claimed in the co-pending application of Arthur W. Hayden et al. Likewise, the frame plate 112 advantageously mounts a pair of stator magnet assemblies 118, 119 of the general type set forth in the said co-pending application.

In the FIG. l device, the

resilient brushes

115, 116 are anchored above the commutator 117 and have portions extending a substantial distance below the commutator. Positioned between the lower end portions of the brushes is a pallet member 129` mounted on a resilient member 127, which is attached at the one end to the upper end of a pendulum 121 and at the other end to a post 128. The post 128 is, in turn, supported by an appropriate bracket 123.

The pendulum 121 comprises a threaded lower portion 121 adjustably mounting a weight 124 to accommodate adjustment of the effective length of the pendulum and thereby its period of oscillation. The resilient member 127 mounts the pallet member in a position generally between a pair of banking pins 125, 126 arranged to limit the side-to-side movement of the resilient member 127 and hence the pallet member. In addition, the resilient member 127 provides for a limited amount of overtravel of the lower portion of the pendulum following engagement of the resilient member '127 with one of the banking pins 125, 126.

After suitably leveling the clock and connecting the motor to its source of current, the pendulum may be set in motion by hand. At each swing of the pendulum, the motor will rotate one-half turn, and the unit will govern in the manner indicated schematically in FIGS. l2-l5a. Thus, when the pendulum swings to the left, for example, the pallet member 12) allows the brush 116 to contact the small radius 117a of the commutator and close the motor circuit. Upon continued rotation of the eccentric commutator 117, the brush 116 is displaced to the right, while the brush 115 is held in a displaced position by the pallet member 129, whereupon the motor circuit is broken.

When the pendulum begins to swing in a return direction, the displaced brush 115 is released and allowed to move into contact with the commutator 117 to :re-establish the motor circuit. The energy stored in the displaced brush is thereby imparted to the pendulum so that, in continued operation, the pendulum is maintained in motion. Such impulses of energy are, of course, accurately uniform, since a displaced brush moves through a Xed distance on each occasion. Thus, when a brush is held in a displaced position by the pallet member 120, the brush is a fixed distance from the commutator axis, the pallet member 120 being positioned on the resilient member 127 pressing against one of the banking pins 125, 125. The displaced brush then moves from the fixed reference position into contact with the portion 117:1 of the commutator, which has a uniform diameter. By thus assuring substantial uniformity of the energy impulses imparted to the pendulum, the amplitude of swing of the pendulum is maintained substantially constant, as is its period of oscillation.

The form of the invention shown in FIGS. l0 and ll is similar to those shown in FIGS. 1-9, in that forces in the constant speed device or system (e.g., the pendulum, balance wheel, etc.) are applied to maintain a displaced brush or contact member in a displaced position to effect interruption of the supply of power to the motor when the commutator rotates away from the displaced brush or contact member. It should be noted that, in so doing, no energy is taken from the constant speed device, and, therefore, the timekeeping ability of the constant speed device is unaffected.

While the device of FIGS. and 11 utilizes an eccentric commutator of the general type described and claimed in the beforeinentioned co-pending application of Arthur d W. Hayden, it will be apparent that a motor driven, electrically non-functional cam may be utilized in place of the commutator, to open and close contacts, substantially as shown in FIG. 9.

The various forms of the invention are characterized by their ability to operate with extremely high timing accuracy, from a direct current source, such as a battery. In this respect, the present invention utilizes basic concepts set forth in the Arthur W. Haydon United States Patent No. 2,523,298. However, the device of the present invention constitutes a substantial specific departure from the patented device, in that the timed closing of switch contacts is effected by the controlled application of force to the switch contacts to restrain them from closing prior to the desired instant, such force resulting from energy stored in the constant speed mechanism or device, without absorbing energy therefrom.

It should be understood that the specific forms of the invention herein described are representative only, as certain changes may be made therein without departing from tie clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

I claim:

1. In a chronometric governor, the combination of an electric motor, a power source adapted when connected to said motor to tend to accelerate said motor to a speed greater than a predetermined operating speed, circuit means operatively normally to complete a power circuit between said source and motor, cam means driven by the motor and operable to open the circuit at instants determined by rotation of the motor, and means for effecting closure of the circuit periodically at instants independent of the rotation of the motor comprising resilient switch means and an oscillating energy storage device coacting directly with said switch means and operative periodically to apply a restraining force to said switch means and to effect the controlled release of such force in accordance with the displacement of said energy storage device, said restraining force being at all times a function of the displacement of said energy storage device.

2. The governor of claim 1, in which the energy storage device is a balance wheel and hair spring assembly, with one end of the hair spring acting upon the balance wheel and the other end of the hair spring acting upon the switch means.

3. The governor of claim 1, in which the energy storage device is a pendulum.

4. The governor of claim 3, in which the pendulum comprises a weight and an arm supporting the weight for swinging movement about an axis, banking means are positioned on opposite sides of the arm, near the swing axis, for limiting swinging movement of the upper portion of the arm, and at least a portion of the arm is formed of resilient material to provide for overtravel of the weight.

5. The governor of claim l, in which the switch means comprises a pair of contact members mounted for resilient movement and displaceable from side to side by said cam means, and said energy storage device comprises a movable restraining member positioned between the contact members and engageable with a cam-displaced contact member to retain such contact member in a displaced position until a predetermined instant in the oscillating cycle of the energy storage device.

6. The governor of claim 5, in which the restraining member is an impulse lever mounted for swinging movement, the energy storage device further includes a balance wheel and a hair spring, and one end of the hair spring is anchored by the impulse lever.

7. The governor of claim 6, in which banking pins are positioned on opposite sides of the impulse lever to limit the oscillating movement thereof and thereby tix the retained displacement positions of the resilient contact members, a retained contact member being thus movable through a fixed distance, from its fixed displacement position to a position in contact with the cam means, immediately prior to the instant of circuit closing, to impart a predetermined sustaining energy impulse to the constant speed device.

8. The governor of claim 7, in which magnetic means are provided tending to retain the impulse lever in oontact with the banking pins, the retaining force of said magnetic means being less than the restoring force of the contact members.

9. The governor of claim 5, in which the resilient contact members comprise brushes, and the cam means comprises a non-circular commutator member for the motor.

l0. In a chronometric governor, the combination of an electric motor, circuit means including a power source adapted to be connected tosaid motor and adapted when so connected to tend to accelerate said motor to a speed greater than a predetermined operating speed, motor driven means for opening the circuit periodically at instants determined by the rotation of the motor, resiliently operable switch means in said circuit, and an oscillating energy storage device for effecting closure of the circuit periodically, at instants independent of the rotation of the motor by acting directly on said switch means periodically to apply a restraining force to said switch means and to effect the controlled release of such force in accordance with the energy stored in said device, said restraining force being at all times a function of the energy stored in said device.

11. The governor of claim 10, in which the switch means is opened by said motor and caused to close by said energy storage device.

12. The governor of claim 10, in which said switch means is displaced periodically by said motor to impart stored energy thereto, and said switch means acts upon said energy storage device through a fixed distance during oscillating cycles to impart sustaining energy impulses thereto.v

13. The governor of claim 10, in which the energy storage device is a pendulum.

14. The governor of claim 10, in which the energy storage device is a balance wheel and hair spring assembly.

15. The governor of claim 10, in which the motor driven means comprises a cam.

16. The governor of claim 15, in which the cam is also a commutator, and in which the switch means comprises brushes resiliently engaging the commutator and displaceable from side to side thereby.

17. In a chronometric governor, the combination of an electric motor, circuit means including a power source adapted to be connected to said motor and adapted when so connected to tend to accelerate said motor to a speed greater than a predetermined operating speed, motor driven means for opening the circuit periodically at instants determined by the rotation of the motor, switch means including a resilient member for effecting closure of the circuit, constant speed means comprising an oscillating energy storage device, motor driven means for periodically deecting said resilient member, control means forming part of said energy storage device for restraining said resilient member in a predetermined dellected position by the application thereto of a restraining force derived from stored energy in said energy storage device, said force being controllably released at a predetermined point in the oscillatory cycle of said energy storage device to effect the return of said resilient member to a starting position, said resilient member acting upon said energy storage device during such return to impart a predetermined energy impulse thereto, said restraining force being at all times a function of the stored energy in said energy storage device.

18. The governor of claim 17, in which said control means is a control member movable between two fixed positions, said motor driven deliecting means is operative to deflect said resilient member sufficiently to accommodate movement of said control member toward said resilient member and into one of said lixed positions without contacting the deflected resiliently operable member.

19. The governor of claim 18, in which banking means are mounted adjacent said control member to limit movement thereof and determine the said fixed positions thereof.

20. The governor of claim 19, in which said banking means include means for effecting the magnetic attraction of said control member toward said fixed position, said last mentioned means having an attracting force less than the restoring force exerted upon said control member by said resilient member.

21. In a chronometric governor, the combination of an electric motor, circuit means including a power source adapted to be connected to said motor and adapted when so connected to tend to accelerate said motor to a speed greater than a predetermined operating speed, motor driven means for opening the circuit periodically at instants determined by the rotation of the motor, switch means including a resilient member for effecting closure of the circuit, constant speed means comprising an oscillating energy storage device, motor driven means for periodically deflecting said resilient member, a control member supported for swinging movement through a limited angle, said control member being attached to and forming part of said energy storage device, spaced positive stop means for limiting the swinging movement of -said control member, said control member being freely movable between said stop means, said control member being engageable by said resilient member and being operative controllably to restrain said resilient member in displaced positions determined by said stop means.

22. The governor of claim 21, in which the control member is part of a pendulum.

23. The governor of claim 21, which includes a balance wheel and a hair spring attached at one end to the balance wheel, and the control member is attached to the other end of the hair spring and serves as an anchor therefor References Cited in the le of this patent UNITED STATES PATENTS 2,523,298 Haydon Sept. 26, v1950 2,740,080 Haydon Mar. 27, 1956 2,840,773 Kavanaugh et al June 24, 1958 2,869,062 Haydon Jan. 13, 1958