US2631664A

US2631664A - Time-delay relay

Info

Publication number: US2631664A
Application number: US229774A
Authority: US
Inventors: Arthur B Poole
Original assignee: HAYDON Manufacturing Co Inc
Current assignee: HAYDON Manufacturing Co Inc; HAYDON MANUFACTURING COMPANY Inc
Priority date: 1951-06-04
Filing date: 1951-06-04
Publication date: 1953-03-17
Anticipated expiration: 1970-03-17

Description

March 17, 1953 A. B. POOLE 2,631,664

T1MEDELAY RELAY Filed June 4, 1951 5 sheets-sheet 1 i .l 3T, 9192/575; o r/z.

zg-022 Q5 a ,i4

l li' 'f V Ivlllllillll'! JNVENTOR. ARTH UR B. POOLE March 17, 1953 A. B. POOLE 2,631,664

TIME-DELAY RELAY Filed June 4, 195] 5 Sheens-Sheetl 2 INVENTOR. 7g3 ARTHUR B. POOLE Y B @M5 ,6m-w

March 17, 1953 A. B. POOLE 2,631,664

TIME-DELAY RELAY Filed June 4, 1951 5 sneeis-sneet 5 f3 w um?? OEE gc usm, Q wb INVENTOR. ARTHUR B. POOLE Wwf@ March 17, 1953 Filed June 4, 1951 A. B. POOLE 2,631,664

TIME-DELAY RELAY 5 Sheets-Sheet 4 r SN? G INVENTOR. ARTHUR B. P OOLE Mfw March 17, 1953 A. B. POOLE 2,631,664

TIME-DELAY RELAY Filed June 4, 195] 5 Sheets-Sheet 5 JNVENTOR. \0 ARTHUR B. POOLE Q BY l Patented Mar. 1.7, 1953 TIME-DELAY RELAY Arthur B. Poole, Harwinton, Conn., assigner to Haydon Manufacturing Company, Inc., Torrington, Conn., a corporation of Connecticut Application .l' une 4, 1951, Serial No. 229,774

Claims.

The present invention relates to electrical relays, and, more particularly, to an improved motor driven time delay relay which is suitable for establishing or interrupting circuit connections to a controlled circuit for a predetermined time interval after energization of the relay.

In relays of the character described, it is customary to use a small, relatively inexpensive, constant speed synchronous motor as a power source for driving the timing mechanism of the relay whereby accurately controlled and long time delays are possible. However, such a motor is of relatively low power output with the result that the contact pressure available to close the relay switch contacts is relatively small. Also, when the driving motor operates the switch contacts directly, the speed of contact closure is dependent upon the motor speed and is necessarily relatively slow in most applications. Certain arrangements heretofore proposed have provided a ilexible switch member which is stressed when the relay is energized to store sufficient energy therein to permit rapid and positive closure of the switch contacts at the end of the time delay interval. In general, however, such prior relay structures are not capable of being immediately reset, due to improper meshing of the gears, or the like, are usually quite complicated structurally, and are so designed as to require an inordinate mounting space.

Accordingly, it is an object of the present invention to provide a new and improved time delay relay of the character described.

It is a further object of the present invention to provide a new and improved time delay relay which may be substantially immediately reset to its initial position and wherein a low power driving motor may be employed.

It is another object of the present invention to provide a new and improved time delay relay wherein a low power driving motor may be employed and the time delay interval may be conveniently adjusted by manually operable means.

Still another object of the present invention is to provide a new and improved time delay relay wherein a low power driving motor may be employed and the time required to reset the relay may be conveniently adjusted by manually operable means.

Another object of the present invention resides in the provision of a time delay relay wherein a low power driving motor may be employed and the timing gears remain in mesh throughout the relay cycle to facilitate substantially immediate resetting of the relay.

It is another object of the present invention to provide a new and improved low power input time delay relay which is of simple and economical construction, is small in size, and requires only a small amount of space.

It is still another object of the present invention to provide an integrating time delay relay which requires a relatively low power driving motor and wherein the relay is substantially immediately reset at the end of a predetermined time delay interval.

A further object of the present invention resides in the provision of a new and improved time delay relay wherein the total time delay may be automatically increased or decreased in accordance with a second signal which occurs after the relay is first operated.

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the present invention, reference may be had to the accompanying drawings in which:

Fig. 1 is a front elevational view of one embodiment of a time delay relay embodying the present invention;

2 is a rear elevational view of the relay of Fig. 3 is a view taken in the direction of the arrows 3 3 of Fig. 1;

Fig. 4 is a view taken in the direction of the arrows 4 4 of Fig. 1;

Fig. 5 is an enlarged sectional view taken on line 5 5 of Fig. 1;

Fig. 6 is a sectional view taken on line 6 6 of Fig. 5, assuming that Fig. 5 shows the complete structure;

Fig. 7 is a fragmentary view looking in the direction of the arrows 1 1 of Fig. 5, and assuming Fig. 5 shows the complete structure;

Fig. 8 is an enlarged top view of Fig. 1;

Fig. 9 is a front view on a larger scale of the relay of Fig. 1 with portions thereof partially broken away;

Fig. 10 is a somewhat distorted perspective view of the relay of Fig. 1 shown connected in an electrical circuit in order to aid in understanding the operation of the relay in performing certain control functions with respect to a load circuit; and

Figs. 1l and 12 are views similar to Fig. 10 of alternative embodiments of the relay of the present invention.

Briey, in accordance with one aspect of the invention, the time delay relay includes a con- 3 stant speed electric motor which is adapted to drive a differential gear train including a normally stationary differential cage. An electromagnetic relay having an armature normally biased away from the coil thereof is provided and the relay and motor are smul-taneously energized at the start of the time delay interval. A switch actuating spring carried by the relay armature is restrained by latch means whereby the armature stresses the spring when the relay is operated. Also, when the relay is operated the driven gear of the differential gear train is held stationary so that the differential cage is rotated in a predetermined path so as to engage the latch means after a predetermined time delay interval to trip the latch means thereby releasing the switch actuating spring and modifying connections to a controlled time delay circuit. Movement of the differential cage beyond the latch trip position causes the motor to be deenergized and when the controlling circuit is opened both the differential cage and latch means are returned to their respective initial positions. In accordance with a further aspect of the invention the time delay interval is conveniently adjusted by adjusting the normal stationary position of the differential cage. Furthermore, the return time of the differential cage may be adjusted to obtain a predetermined reset interval.

Referring now to the drawings, and more particularly to Figs. l to 10, inclusive, thereof, the present improved relay is therein illustrated as generally comprising a mounting plate ifi on one side of which is mounted a small self-starting synchronous motor l! which is adapted to be energized from a suitable single phase source more fully described hereinafter. also supported from the same side of mounting plate te is an electromagnet indicated generally at i2. On the other side of the mounting plate lll there is provided the time delay mechanism indicated generally at i in Fig. 5 of the drawings. The driving motor il may be of relatively low power output and includes a standard gear reduction mechanism indicated generally at i3 which reduces the speed of the motor drive shaft and provides a relatively low speed output shaft id (Figs. 5 andr 10) suitable for driving the timing mechanism I5.

As best shown in Figs. 3 and 7 of the drawings, the electromagnet l2 includes a core stucture I8 which is made up of E-shaped laminations on the center leg of which there is positioned the coil I9. An armature 2li is hinged by means of the pin 2| to one leg of the core i8 and is normally biased away from the coil i9 by means of the coil spring 22.

Generally considered, the time delay mechanism l5 includes a triangular shaped back plate 30 which is separated and supported from the mounting plate I by means of the spacers 3i and mounting screws 32 respectively. The back plate 30 supports a bearing 34 in which is journaled one end of a timing shaft 35, the other end of which is journaled in the mounting plate it. The timing shaft 35 carries a driving gear 36 fastened thereto which meshes with a driving pinion 31 rotatable with the motor drive shaft it. The timing shaft 35 also carries adiilerential cage 38 rotatable thereon which iny turn carries the differential gears 39 Aandvll which are fixed except for rotationabout theiraxes relative to cage 38. A driven gear 4l is secured by means of a hub 42 to a ratchet wheel 43, and the driven gear 4I and ratchetv wheel i3 are all adapted to rotate about the timing shaft 35 just as is the cage 38.

As best illustrated in Figures 5, 6, and 9, the differential cage 38 comprises a relatively flat plate 45 which is mounted on the shaft 35 for rotation thereabout and is counter-balanced on one end by means of an arcuate counter weight fit rigidly attached thereto which offsets the weight of the differential gears 39 and il carried by the plate 135. The plate 45 is provided with a recess li'l adapted to receive the differential gears 3d and it and these gears are mounted between opposed ear portions 159 and El) of the mounting plate 153 by means of the pins 5i and 52. The differential gears 39 and 46 mesh with each other as shown at S3 (Fig. 6) While the gear 39 also meshes with the driven gear dl, and the gear 4i) meshes with the driving gear 36.

The timing shaft bearing 34 also carries a toothed adjustment wheel which may be r0- tated by means of an adjustment pinion Eid which meshes with the wheel 55 and may be adjusted by means of an adjustment screw l available at the outside of back plate 30. The adjustment wheel 5:3 is biased against the back plate 30 through the spacer 53 by means of va conical friction spring di) which is carried on the inner portion of the 4bushing 3d and effectively presses the adjustment wheel 55 against the back plate 3d so as to maintain this wheel stationary during the time delay operation.

In order to control the initial position of the differential cage 33, the adjustment wheel 55 is provided with a iiat side G2 (Fig. 1) to which there is secured a projecting arm 63 which acts as a stop for the dierential cage 38. More specifically, the differential cage 3S is provided with a projecting arm 64 which extends beyond the stop arm 63 and the differential cage is normally biased against the stop arm 63 by means of a coil spring 6B which is secured at one end to one of the spacers 3| and extends around and is secured to a grooved bushing BS'which is positioned on the timing shaft 35 and fastened lto the cage 33. Thespring 66 thus biases the differential cage 38 clockwise as viewed in Fig. 9 so that the arm S4 thereof is normally held against the stop arm 63 as indicated in Fig. l of the drawings.

For the purpose of holding'thedriven gear vil! of the differential gearing stationary so that the differential cage 38 can be rotated during the time delay interval, there is provided a ratchet pawl indicated generally at 'iii which is rotatably mounted on the pawl shaft 'il and is vprovided with teeth 'i2 adapted to mesh with the teeth on the ratchet wheel liti. The position of the pawl iii on the shaft 'il is determined by a pawl bushing 69 which is press fitted on the shaft 'ii and the ratchet pawl 'ifi is Vnormally held against 'the bushing 69 and biased into engagement with the ratchet wheel 43 by means of the torsion coil spring i3 (Fig. .7) and is provided at one end thereof with a cam ear 'M which is positioned over an upstanding pin it carried by the relay armature 20. As mentioned above, the relay armature 28' is normally biased away from the relay coil E9 by the spring 22 and in this positionthe pin' l5 engages the ear portion 'l and cams the ratchet pawl 'it away from the ratchet wheel t3 as is clearly' evident from'Fig. 5 ofthe drawings. Accordingly, when the relay i2 is de-energized las shown in Figs. 3 and5, and the relay armature 2t is in itsuppermostposi- 5 tion, the ratchet pawl 'I0 is disengaged fromV the ratchet wheel 3.

To establish electrical connection to a controlled time delay circuit there is provided a switch mechanism indicated generally at 83 which is mounted on the mounting plate I directly above the above-described time delay mechanism as viewed in Figs. 1 and 3 of the drawings. The switch mechanism 8B may comprise a set of normally open or a set of normally closed contacts depending upon the desired control. As illustrated the switch mechanism 3D includes both a set of normally open and a set of normally closed contacts for more universal application and comprises a pair of flexible switch blades 8| and 83 and a central switch blade 82 (Fig. 8) which are embedded in the stacked insulator blocks 84, 85,

and @c and are secured in stacked relation to thev mounting plate it by any suitable means such as the supporting

studs

81 and 88. The eXible switch blade Sl is provided intermediate the length thereof with a switch contact 9B adapted to engage a complementary switch contact 9i positioned on one side ci the central switch blade 82. Likewise the flexible switch blade S3 is provided with a switch contact 93 adapted to engage with a complementary switch contact Si. on the other side of the central switch blade 82.

In order to move the flexible switch blades 8i and 83 in unison relative to the central blade 82 so that the switch contacts S?, SI and @2, d3 may be opened and closed, there is provided a switch actuating member Q5 of insulating material which is positioned between the ends of the switch blades 8l and 83 and is provided with a portion 96 of reduced diameter between the blades 8| and 83 (Fig. 7). The notch SI5 is adapted to receive the biiurcated end 99 of a switch actuating spring Idil, the other end of the spring h'iil being secured to the hinged end of the relay armature 2t.

For the purpose of restraining the switch actuating spring when the relay armature 2d is closed whereby suicient energy may be stored in the spring Itli to cause rapid and positive actuation of the contacts 93', SI and 92, 93 upon the release of the actuating spring it, there is provided a latch member m5 which is rotatably supported on a latch shaft I and is provided with a projecting arm portion IIl'I which is adapted to t under the edge of a notch IGS (Figs. 9 and 10) in the side of the switch actuating spring Iii. The latch H35 is seated on the upper end of a latch bushing II! which is press tted on the shaft H35 and the latch is normally biased into engagement with the spring |00 by means of the torsion spring i139 which also keeps the latch seated on the bushing III. The latch |55 is adapted to be tripped by the differential cage 3S when the latter member has been rotated counterclockwise, as viewed in Fig. 9 by an amount suicient to cause the cage 33 to strike the end I i9 of the latch |05 and thus rotate the latch clockwise as viewed in Fig. 9 to withdraw the arm portion IG'I thereof from beneath the spring Ill-il and release the spring. The time delay interval is thus equal to the time required for the diferential cage 38 to travel from its initial position, as determined by the position of the stop arm $3, to its latch tripping position at which time the

switch contacts

92 and 93 are closed and the contacts 9B and 9| are opened.

To provide an indication of the time delay setting of the relay while permitting this time delay setting to be adjusted by means of the adjustment screw 5l, there is dened in the back `plate a viewing opening II (Fig. il'

through which is visible a circle of graduations I2 I inscribed-upon the adjustment wheelV 55. The graduations I 2i arecalibrated in terms of the time delay intervals for different positions of the stop arm 63 and a reference marker I22 is provided on the plate 3) to permit an accurate setting of the time delay.

In order to deenergize the driving motor I I after the switch 8B has been actuated and the desired circuit connections established, there is provided a motor control switch indicated generally at |29 (Figs. 2 and 10) which includes a generally U-shaped flexible switch blade ISB which is normally engaged with a stationary switch contact ISI, the switch blade IBD and contact I3! being supported by suitable terminal brackets on a mounting plate I53 which is in turn supported on the plate I il. To open the motor switch contacts after the time delay interval is completed, a tripping arm 535 is provided which is secured to the latch bushing III and extends outwardly beyond the switch actuating spring Illil as best illustrated in Figs. 2 and 9, and is adapted to engage an intermediate point on the flexible switch blade ISD when the latch i5 is moved beyond its spring releasing position by the difierential cage 38. The operation of the time delay relay discussed above, can best be understood by reference to Fig. 10 of the drawings depicting a somewhat distorted perspective view of the relay of Fig. l, and, moreover, illustrating this relay in a typical circuit application. The corresponding parts of Fig. l0 have been designated by the same reference numerals as in the preceding iigures. Referring to Fig. l0, it may be observed that the incoming line terminals |46 and itl are connected to energize both motor Il and the coil I9 of the electromagnet I2 in parallel. The line terminals are also connected to supply a load circuit which should be energized after a predetermined time delay through the normally open switch contacts 92-93 of switch Sil. When the synchronous motor II is energized, it drives, through the gear reduction mechanism I3 thereof and through the motor drive shaft I4, the motor pinion 3'! in a clockwise direction as viewed in Fig. l0, which in turn rotates the driving gear and the timing shaft 35 in a counterclockwise direction. The diierential cage 38, which is rotatably supported on the timing shaft 35, is initially held stationary by engagement of the arm S thereof with the stop arm 63 on the adjustment wheel 55, the engagement of these members being maintained by the direrential cage return spring 66. With the differential cage 35 held stationary, rotation of the driving gear 35 produces rotation of the difierential gear l0 in the clockwise direction, which in turn rotates the differential gear 39 in the opposite direction so as to rotate the driven gear 4I and the ratchet wheel t3 in the clockwise direction. However, such operation continues only until the relay armature 25 is in its fully attracted position at which time the ratchet pawl IB engages the ratchet wheel i3 and stops the driven gear 4I from rotating. When the driven gear 4I is held stationary in the manner described above, the differential cage 38 is then rotated in the counterclockwise direction, the differential gears 39 and 4B being rotated along the peripheries of the rotating driving gear 3'5 and the stationary driven gear I respectively. As a result, the diierential cage is moved in the direction shown by the .arrow following energization of the electromagnet I2 and when the armature 20 thereof is in its fully attracted position.

When the electromagnet 2 is operated and the armature 20 thereof moves downwardly under the attra-ction of the armature coil I9, the lswitch actuating spring |00, which is secured at one end to the relay armature 20, is restrained by means of the latch |05 which is provided with the extension arm |07 positioned beneath the switch actuating spring |00, the latch |05 being biased into the spring engaging position by means of the spring IMI. The outer end of the switch actuating spring engages the switch actuating member 95 of the switch mechanism .80. .In the position shown in Fig. 10, the contacts 90 and 9| associated with the switch blades 8| and .82 are closed and the contacts 92 and 53 associated respectively with the

switch blades

82 and 83 are opened. Accordingly, in the position shown in Fig. 10 the line circuit is open at the switch 80 and the time delay load circuit M5 is deenergized.

When the diierential cage 38 is rotated in the manner described above to a point at which it engages the projecting arm I Iii of the latch member |05, this member is rotated so as to remove the arm |07 thereof from beneath the switch actuating spring, thus releasing this spring. When the spring |00 is released, the energy stored by virtue of the 'stressing action of .the armature 20 of the electromagnet I2 produces a snap actuation Aof the switch mechanism 80 with the result that the `

contacts

52 and 93 are rapidly and positively closed and the contacts 90 and 9| are rapidly opened. When the contacts 02 and 93 are closed, a connection is made from the line terminal Mii and through the contacts 92 and e3 to the time delay load circuit |45, thus energizing this circuit.

inasmuch as the motor II remains energized after the time delay interval is passed, the differential cage 3S continues to rotate in a counterclockwise direction and continues to rotate the latch i525 in the clockwise direction. As a result, the projecting arm |35 of the latch |05 is moved into engagement with the movable arm Its of the `motor switch |20 so that the motor switch contacts are opened and the motor is deenergized. However, since the line circuit to the terminals M0 and |4I is still maintained, the relay coil le remains energized and the timing mechanism remains in the condition described immediately above with power being supplied to the load |115.

When the line circuit is opened, the relay armature coil i9 is deenergized and the armature 20 thereof moves upwardly under the influence of the spring 22 so as to release the ratchet pawl 'I0 from the ratchet wheel e3. As a result, the differential cage 33 is returned to its initial 'position by means of the return spring 66 so that the arm @4i thereof is again in engagement with the stop arm t3 carried by the adjustment 'wheel 55. When the relay armature 20 moves upwardly the switch actuating spring |00 also moves in the same direction so as to permit the arm |01 of the latch member to be moved under the spring ist by means of the latch return spring |09. When the latch member |05 is moved to the spring engaging position, the arm |35 'is disengaged from the motor blade |30 so that the motor is again ready for energization. The time delay relay of the present invention is then ready for another cycle of operation.

In the event Vthat vthe time delay interval is to 'be changed, the adjustment screw '551 is-rotated so as to rotate the adjustment wheel 55 thereby varying the stationary position of the differential cage 38. In this connection, it will be understood that the diierential cage 38 is moved at a constant rate from its initial position to the latch engaging position under the control of the constant speed motor Accordingly, a variation in the initial position of the cage 35 provides a linear variation of the same delay interval.

From the above description, it will be apparent that there has been provided a time delay relay which has numerous applications such as for turning on the plate circuit of an electron discharge valve a predetermined time after the lament current is turned on.

With the arrangement described thus far, the time delay relay repeats its cycle following each operation thereof. In certain applications it is desirable to have an integrating time delay relay and in Fig. ll of the drawings there is illustrated such a modication of the present invention. Referring to this gure, .the time delay relay shown therein is identical in many respects tothe time delay relay of Figs. l to l0, inclusive, and the corresponding elements of these relays have been given the same reference numerals. In general, the time delay relay of Fig. il embodies the features oi the present invention in an integrating type of time delay relay wherein the relay integrates or sums up successive time intervals when a circuit is closed to the line terminals It@ and lil! and energizes the load circuit when the desired total time delay is reached.

More specically, the ratchet pawl 'I0 is not controlled by the relay armature 20 as in Fig. 10 but instead is normally biased into engagement with the ratchet wheel I3 by means of .the biasing spring |45. Accordingly, when a circuit is closed to the line terminals |00 and |5| and the motor II is energized, the ratchet wheel e3 is held stationary and the differential cage 33 immediately begins to move in the counterclocltwise direction to engage the latch arm H0. If the circuit to the line terminals |40 and |4| is opened momentarily, the motor I I and the relay I2 are deenergized and movement of the diierential cage is stopped. However, the diierential cage is not returned to its starting position upon release of the relay I2 for the reason that the pawl 'I0 is continuously biased into engagement with the ratchet wheel i3 by the spring |48. The relay thus integrates or sums up the t0ta1 on periods during which a circuit is closed to the line terminals les and IM to obtain the desired total time delay interval. A-t the end of the total time delay interval the differential cage 38 again trips the latch arm 0 to release the switch actuating spring |00 and close the

switch contacts

92 and 93 thereby closing a circuit to the time delay load circuit M5 at the end of the predetermined time delay interval.

When the latch |05 is vtripped and the switch actuating spring |05 is moved downwardly, the spring |00 engages the other end of the pawl I0 so as to disengage the pawl 'it from the ratchet wheel 43 and permit the differential cage 38 to be returned to its initial position by means of the spring .65. The pawl I0 is also provided with an upstanding arm |50 which engages the movable contact |30 of the motor switch so that the motor is deenergized at the instant that circuit connections are made to the time delay load circuit |45. Whenvthe main circuit is opened the relay coill I9 is deenergized and the switch actuating sprngfl 00 returns to its .initial position at whichv 9 position it is Aheld by means'of the latch |05, the controlled circui-t |45 is deenergized, the pawl 10 again engages the ratchet wheel 43, and the motor switch |29 is closed. The integrating relay of Fig. ll is then set up for another cycle of operation.

There are applications where it is desirable to close a load circuit following a predetermined time delay after actuation of the means for closing the load circuit, but with additional means to vary the time delay should another event or subsequent condition occur during the time delay period. In Fig. 12 of the drawings, there is illustrated a modication of the present invention in which such an `arrangement for varying the time delay can be accomplished and the construction is very similar .to that of the relay of Figs. l to 10 with the provision of means including an additional diierential gear mechanism to introduce a change in the speed of operation oi the time delay means at variable times after the original time delay has started. The principle involved in the modiiication of Fig. 12 is that transmission through a diiierential gear mechanism having a stopped cage is accomplished without change of speed, but if the cage is rotated, it will increase or decrease the velocity of transmission, depending upon the direction of rotation thereof. Referring now to Fig. l2 wherein the corresponding parts are designated by the same reference numerals as in the preceding drawings, the elements are substantially identical with the disclosure of Fig. l except for the provision of a second diierential gear train generally designated at |49, including a cage |55 very similar to the cage 3S of the differential already described -except for the provision of a eripheral gear portion thereon, which gear train is interposed between the motor I! and the pinion 31. Associated with the diierential gear train |49 is a second electromagnet |5I capable of being energized from a suitable signal or power source represented by the terminals I 52d and |525. The electromagnet I| is adapted to control an armature |53 pivoted as indicated at |54. A spring means |55 normally biases the armature |53 to the position shown in Fig. 12 of the drawings, but upon energization of the electromagnet 15|, counterclockwise rotation of the armature |53 about the pivot |54 occurs with the result that a pawl portion |51 of the armature |53 is rendered effective to engage the teeth of the cage |55 and prevent rotation thereof.

For the purpose of increasing or decreasing the speed of rotation of the pinion 31, illustrated as mounted on a shaft |58, above or below the speed at which it would be driven through the difierenvtial gear train |49 when the cage of the gear train is held stationary, there is provided a gear train for rotating the cage |55 comprising a gear I5| von the shaft I4 which in turn meshes with a gear 'I 62 mounted upon a suitable shaft |63. For purposes which will become apparent from the following description, the gear |52 is connected to the shaft |63 by a. suitable friction clutch schematically designated at |54. The shaft |53 is provided at its other Vend with a gear 65 drivingly engaged with the gear teeth formed on the periphery of the cage |55. It will be understood that by suitable gearing the cage |55 may be rotated in either a clockwise or counterclockwise direction by the gear |65, but for the illustrated embodiment the cage |50 is rotatedin the same direction as the shaft I4. The cage |50 is rotatable about shaft |61 which corresponds to the shaft 35 of the other differential gear train already described. Associated with the cage |55 are diierential gears |59 and |15. These differential gears are carried by the cage |55 and the differential gear |59 meshes with a driving gear |1| attached to the shaft |51 while the differential gear |15 meshes with a driven gear |12 attached to the shaft |58 to which the pinion 31 is also attached whereby rotation of driven gear |12 will cause similar rotation of the pinion 31. For the purpose of transmitting torque through the diierential gear train |49, the shaft I4 is additionally provided with a gear |15 which meshes with the driving gear |1I.

It will be apparent that when the solenoid I5| is deenergized and the motor is energized that the pinion 31 will be driven through the difierential gearing 159 and in addition by virtue of the rotation of the cage |55 the speed of rotation of pinion 31 will be different from what it would be if cage |55 were held mationary. For the arrangement illustrated resulting in rotation of the cage |55 in the same Adirection as the shafts I4 and |58, the pinion31 will rotate at a higher speed than if cage |55 were held stationary. Obviously, by an opposite rotation of cage |55, a reduction in the speed of rotation of the pinion 31 relative to its speed when the cage |55 is prevented from rotating is obtained. It will be understood that depending upon the gear ratios employed, the increase or decrease in speed of rotation of the pinion 31 may be controlled as desired. Upon energization of the solenoid I5I, however, pawl |51 prevents rotation of the cage |55 which means that shaft I 63 muststand still and relative rotation between the gearl|52 and the shaft |53 can occur by virtue of the friction clutch |54. Under these conditions, with the cage |50 prevented from rotating pinion 31 is driven through the differential gearing |49 in a readily understood manner without change in speed relative to that of the shaft I4. Consequently, there is provided a relay which provides a time delay in accordance with the formula t T Ai k where T is the total time delay, A is the normal or set time delay, t is the time that elapses between the closing of the circuit initiating the normal or set time delay and the occurrence of the second signal energizing or deenergizing solenoid |5|, and 7c is a selected constant. A typical application of the device shown in Fig. l2 is one in which there is a normal time delay for controlling a second circuit such as a circuit connected to the terminals |15a and |1517 of the switch 80 after the main circuit to the motor I| is closed and a second signal which occurs after the main circuit closing, but before the time delay has elapsed modifies the time of controlling the second circuit in dependence upon the amount of time of the normal time delay which has elapsed at the occurrence of the second signal. Under these conditions the device measures the remainder of the original time delay and modifies the subsequent delay by an amount which varies with the remainder of the time delay which it nds. Thus, it actually works a computation based on the time relation of the second signal to the occurrence of the closing of the main circuit.

The operation of the device shown in Fig. l2 will readily be understood from the above description. Upon closing the circuit to the line terminals |45 and |4I, the motor is energized and drives the differential cage 38 through the dif'- ferential gearing |49 but modified by virtue of the rotation of cage |50 through shaft |63. After the closure of the main circuit and before the end of the normal or set time delay interval determined by the setting of element 51 and the speed at which pinion 31 is rotated, a second circuit is closed tothe terminals |5201r and |521) thus energizing the solenoid and stopping the differential cage l 50 whereupon the rate of rotation of the differential cage 38 ischanged (reduced in the illustrated embodiment) to change the total time delay interval. When the cage 38 trips the latch member |05, a circuit to the load terminals Illia and |1519 is InodiiiedA to establish (in the illustrated embodiment) the circuit connections to the controlled circuit. The motor is again deenergized by further movement of the latch |55 in a manner identical to that descriped in connection with the relay of Fig. and upon opening of the main line termials vand HH, the switch 80 is restored to its initial position and the relay is reset to its -original position.

While the alternative embodiments of the time delay rel-ay of the present invention have been illustrated as provided with a substantially immediate resetting of the differential cage 38 when the line circuit is opened, it will be understood lthat t'he differential cage may be returned to its initial position by any suitable control means to obtain a desired resetting interval. For example, a self-starting adjustable return escapement may be driven from the timing shaft 35 in any one of the embodiments of Figs. 10, 11 and 12, so as to control the nate at which the differential cage is returned to its initial position under the action of the return spring 66. The reset interval can be vari-ed in small increments by shifting a counterweight on the end of the escapement. Also, the reset interval may be changed by large increments by varying the gear ratio between the timing shaft .'55 and the escalpement wheel. In this connection, it will be understood that the reset time will be substantially proportional to the time delay interval due to the fact that the differential cage is moved through a greater distance for a long time delay interval than for a short' time delay interval.

It will also be understood that the time delay relay of the present invention may be utilized in a two-period, repeating cycle timer. For example, two time delay relays of the type shown in Figs. 1 to l0, inclusive, of the drawings can be employed to give a timing range for two parts of a given time cycle. Thus, aiirst time delay relay can be provided with a cycle of twenty-four hours, and a second timer with a cycle of live seconds, to use an extreme example. By connecting the two relays in series, that is, by controlling the second relay from the switch mechanism 80 of the nrst relay, a time delay control can be obtained once every twenty-four hours within a predetermined five second range. However, in order to provide such an arrangement, it is necessary to provide a starting switch in series with the rst driving motor. Such a two-period timing relay may also be made nonrepetitive by providing a timed oi cycle plus a timed on cycle after which the circuit locks out -until a starting switch actuated to normalize the relays.

Although the invention has been described with the differential cage as the switch actuating element of the differential, it will be understood that the functions of the three elements of the diderential, namely the driving gear, the cage, and the driven gear, may be nterchanged. For example, the `relay could be designed with the cage as the locked elementy and the driven gear as the switch actuator. While there havev been described what are at present considered to be the preferred embodiments of the invention, it will be understood that various changes and modifications will occur to those skilled in the art and it is aimed in the appended claims to cover all such changes and modications as fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. In a time delay relay, means comprising a switch having relatively movable switch contacts, an electric motor, differential gearing drivingiy connected to said motor and including a nore mally stationary dilerential cage, an electromagnet having a movable armature, means for simultaneously energizing said electromagnet and said motor, switch actuating energy storage means, means responsive to movement of said armature upon energization of said electromagnet for storing energy in said energy storage means, latch means for maintaining energy stored in said energy storage means, means for holding stationary one of the gears of said difierential gearing whereby said diiierential cage is rotated in a given direction in response to operation or said motor, and means responsive to movement of said cage to a :predetermined position for tripping said latch means thereby to release the energy stored in said energy storage means to actuate said switch.

2. In a time delay relay, means comprising a switch having relatively movable switch contacts, an electric motor, differential gearing drivingly connected to said motor and including a normally stationary differential cage, an electromagnet having a movable armature, means for simultaneously energizing said electromagnet and said motor, switch actuating energy storage means, means responsive to movement of said armature upon energization of said electromagnet for storing energy in said energy storage means, latch means for maintaining energy stored in said energy storage means, means responsive to energization of said electromagnet for holding stationary one of the gears of said diiierential gearingv whereby said differential cage is rotated in a given direction in response to operation of said motor, and means responsive to movement of said cage to a predetermined position for tripping said latch means thereby to release the energy stored in said energy storage means to actuate said switch.

3. In a time delay relay, means comprising a switch having relatively movable switch contacts, an electric motor, differential gearing drivingly connected to said motor and including a normally stationary differential cage, an electromagnet having a movable armature, means for simultaneously energizing said electromagnet and said motor, a switch actuating spring, means responsive to movement of said armature upon energization of said electromagnet for stressing said switch actuating spring, latch means for restraining said switch actuating spring in stressed condition, means responsive to energization of said electromagnet for holding sta tionary one of the gears of' said dii'erential gearing whereby said dilerential cage is rotated in a given direction in response to operation of said motor, and means responsive to movement oi' said cage to a predetermined position for tripping said latch means thereby to release said stressed switch actuating means to actuate said switch.

4. In a time delay relay, means comprising a switch having relatively movable switch contacts, an electric motor, differential gearing drivingly connected to said motor and including a normally stationary differential cage, an electromagnet having a movable armature, means for simultaneously energizing said electromagnet and said motor, a switch actuating spring, means responsive to movement of said armature upon energization of said electromagnet for stressing said switch actuating spring, latch means for restraining said switch actuating spring in stressed condition, means responsive to energization of said electromagnet for holding stationary one of the gears of said differential gearing whereby said differential cage is rotated in a given direction in response to operation of said motor, and manually operable means for adjusting the normally stationary position of said cage thereby to vary the time delay control of said relay.

5. In a time delay relay, means comprising a switch having relatively movable switch contacts, an electric motor, differential gearing drivingly connected to said motor and including a normally stationary differential cage, an electromagnet having a movable armature, means for simultaneously energizing said electromagnet and said motor, a switch actuating spring, means responsive to movement of said armature upon energization of said electromagnet for stressing said switch actuating spring, latch means for restraining said switch actuating spring in stressed condition, means responsive to energization of said electromagnet for holding stationary one of the gears of said differential gearing whereby said diiferential cage is rotated in a given direction in response to operation of said motor, means responsive to movement of said cage to a predetermined position for tripping said latch means thereby to release said stressed switch actuating means to actuate said switch, and means responsive to movement of said cage beyond said predetermined position for deenergizing said motor.

6. In a time delay relay, means comprising a switch having relatively movable switch contacts, an electric motor, differential gearing drivingly connected to said motor and including a normally stationary diierential cage, an electromagnet having a movable armature, means for simultaneously energizing said electromagnet and said motor, a switch actuating spring, means responsive to movement of said armature upon energization of said electromagnet for stressing said switch actuating spring, latch means for restraining said switch actuating spring in stressed condition, means responsive to energization of said electromagnet for holding stationary one of the gears of said differential gearing whereby said dierential cage is rotated in a given direc tion in response to operation of said motor, means responsive to movement of said cage to a predetermined position for tripping said latch means thereby to release said stressed switch actuating means to actuate said switch, means responsive to movement of said cage beyond said predetermined position for deenergizing said motor, and means responsive to deenergization of said 'electromagnet forV returning both said cage and said latch means in their responsive? initial positions.

7. In a time delay relay, means comprising a switch having relatively movable switch contacts, an electric motor, diierential gearing drivingly connected to said motor and including a normally stationary differential cage, an electromagnet having a movable armature, means for simul taneously energizing said electromagnet and said motor, a switch actuating spring, means responsive of movement of said armature upon energization of said electromagnet for stressing said switch actuating spring, latch means for restraining said switch actuating spring in stressed condition, means responsive to energization of said electromagnet for holding stationary one of the gears of said differential gearing whereby said differential cage is rotated in a given direction in response to operation of said motor, means responsive to movement of said cage to a predetermined position for tripping said latch means thereby to release said stressed switch actuating means to actuate said switch, means responsive to movement of said cage beyond said predetermined position for deenergizing said motor, means responsive to deenergization of said electromagnet for returning both said cage and said latch means to their respective initial positions, and escapement means connected to said differential cage for controlling the return time thereof.

8. A time delay relay, comprising a constant speed electric motor, differential gearing driven by said motor and including a diiferential cage carrying a pair of relatively fixed differential gears, an electromagnet having a movable arma# ture, said armature carrying a switch actuating spring, switch means adapted to be actuated by said spring, latch means for normally holding said springv in stressed position following opera tion of said electromagnet, means controlled by said armature for restraining the driven gear of said differential gearing whereby said differential cage is rotated in a given direction, and means carried by said differential cage for tripping said latch means after a predetermined rotation of said cage thereby to release said spring and actuate said switch means.

9. A time delay relay comprising a switch having relatively movable switch contacts, a constant speed electric motor diiferential gearing drivingly connected to said motor and including a normally stationary diiierential cage carrying a pair of differential gears and a driven gear, an electromagnet having a movable armature, switch actuating energy storage means, means responsive to movement of said armature upon energization of said electromagnet for storing energy 1in said energy storage means, latch means for maintaining energy stored in said energy storage means, means responsive to energization of said electromagnet for holding stationary said driven gear whereby said dierential cage is rotated from an initial position to a tripping position at a speed determined by said constant speed electric motor, and means carried by said cage for tripping said latch means when said cage reaches said tripping position thereby to release the energy stored in said energy storage means to actuate said switch.

10. A time delay relay comprising a switch having relatively movable switch contacts, a constant speed'electric motor, differential gearing'rdrivingly connected :tosaid motor and including a normally stationary differential cage carrying a pair of diirerential gears anda driven gear, an electromagnet having a movable armature, a switch actuating spring, means responsive to movement of said armature upon energization of said electromagnet for stressing said spring, latch means for maintaining said spring in a stressed condition, means responsive to energization of said electromagnet for holding stationary said driven gear whereby said differential cage is rotated from van initial position to a tripping position at a speed determined by said constant speed electric motor, means carried by said cage for tripping said latch means when said cage reaches said tripping position thereby to release said .Spring` and permit it to actuate said switch, means controlled by said latch means for deenergizing said motor a predetermined time interval after said cage reaches said tripping position, and spring means for restoring said cage and latch means to their initial positions upon deenergization of said electromagnet.

11. A time delay relay comprising a switch having relatively movable switch contacts, a constant speed electric motor, differential gearingV drivingly connected to said motor and including ya normally stationary differential cage carrying a pair of differential gears and a driven gear, an electromagnet having a movable armature, a switchv actuating spring, means responsive to movement of said armature upon energization of said electromagnet for stressing said spring, latch means for maintaining said spring in a stressed condition, means responsive to energization of said electromagnet for holding stationary said driven gear whereby said differential cage is rotated from an initial position to a tripping position at a speed determined by said constant speed electric motor, means carried by said cage for tripping said latch means when said cage reaches said tripping position thereby to release said spring and permit it to actuate said switch, means controlled by said latch means for deenergizing said motor a predetermined time interval after said cage reaches said tripping position, spring means for restoring said cage and latch means to their initial positions upon deenergization of said electromagnet, and manually operable means for adjusting said initial position of said cage thereby to control the time delay of said relay.

12. A time delay relay comprising a switch having relatively movable switch contacts, a constant speed electric motor, differential gearing drivingly connected to said motor and including a normally stationary differential cage carrying a. pair of differential gears and a driven gear, an electromagnet having a movable armature, a switch actuating spring, means responsive to movement of said armature upon energization of said electromagnet for stressing said spring, latch means for maintaining said spring in a stressed condition, means independent of said electromagnet for holding stationary said driven gear whereby said diierential cage is rotated from an initial position to a tripping position at a speed determined by said constant speed electric motor immediately upon energization thereof, means carried by said cage for tripping said latch means when said cage reaches said tripping position thereby to release said spring and permit it tol actuate said switch, means controlled by said latch means for deenergizing said motor a predetermined time interval after said cage reaches said tripping position, and spring 16 means for restoring said cage and latch means to their initial positions upon deenergization of said electromagnet.

13. A time delay relay, comprising an electric motor, differential gearing driven by said motor and including a normally stationary diiierential cage, an electromagnet having a movable armature, means for energizing both said electromagnet and said motor, an electric switch, a switch actuating spring carried by said armature and tending to move therewith, latch means for restraining said spring whereby upon movement of said armature said spring is stressed in response to energization of said electromagnet, means for normally holding stationary one of the gears of said differential gearing independently of the operation of said electromagnet whereby said diiierential cage is rotated in a given direction during periods when said motor is energized, meansv responsive to movement or said cage to a predetermined position for tripping said latch means thereby tc release said spring and actuate said switch, and means actuated by said spring simultaneously with actuation of said switch for deenergizing said motor and releasing said gear holding means, thereby to permit said cage to return to its initial position.

14. A time delay relay, comprising an electric motor, differential gearing driven by said motor and including a normally stationary differential cage, an electromagnet having a movable armature, means for energizing both said electromagnet and said motor, a switch, a switch actuating spring carried by said armature, latch means for restraining said spring whereby said armature stresses said spring when said electromagnet is operated to move said armature, means for holding stationary one of the gears of said differential gearing whereby said didierential cage is rotated in a given direction, means responsive to movement of said cage to a predetermined position for tripping said latch means thereby to release said spring and actuate said switch, and means controllable independently of said electromagnet for changing the rate of rotation of said differential cage foliowing initial movement thereof thereby to change the time delay interval of said relay in dependence upon the operation of said last mentioned means.

15. A time `delay relay, comprising an electric motor, diierential gearing by said motor and including a normally stationary ferential cage, an electromagnet having a mevable arrnature, means for energizing both said electromagnet and said motor, a switch, a switch actuating spring carried by said armature, latch means for restraining said spring whereby said armature stresses said spring' when said electromagnet is operated to move said armature, means responsive to energization or" said electromagnet for holding sttionary one of the gears of said diierential gearing whereby said differential cage is rotated in a given direction, means responsive to movement of said cage to a predetermined position for tripping said latch means thereby to release said spring and actuate said switch, and means controllable independently of said electromagnet for changing the rate of rotation of said diierential cage following initial movement thereof thereby to change the time,r delay interval of said relay in dependence upon the operation of said last mentioned means.

16. A time delay relay, comprising an electric motor, differential gearing driven by said motor and including a normally stationary differential cage, an electromagnet having a movable armature, means for simultaneously energizing both said electromagnet and said motor, a switch, a switch actuating spring carried by said armature, latch means for restraining said spring to prevent actuation of said switch when said latch means is effective whereby said armature stresses said spring when said electromagnet is operated, means for holding stationary one of the gears of said differential gearing whereby said differential cage is rotated in a given direction, means including a second differential gear train interposed between said motor and said differential gearing and controllable independently of said energizing means for changing the rate of rotation of said cage, and means responsive to movement of said cage to a predetermined .position for tripping said latch means thereby to release said spring.

17. A time delay relay, comprising an electric motor, first differential gearing driven by said motor and including a normally stationary first differential cage, an electromagnet having a movable armature, means for energizing both said electromagnet and said motor, a switch, a switch actuating spring carried by said armature, latch means for restraining said spring from actuating said switch whereby said armature stresses said spring when said electromagnet is energized, means for holding stationary one of the gears of said rst differential gearing whereby said first differential cage is rotated in a given direction, a second differential gear train including a second differential cage and connected between said driving motor and said first differential gearing, solenoid means adapted to be energized after said electromagnet is operated and independently of said energizing means for controlling the movement of said second differential cage thereby to vary the rate of rotation of said rst differential cage. and means responsive to movement of said rst differential cage to a predetermined position for tripping said latch means thereby to release said spring and actuate said switch.

18. A time delay relay, comprising an electric motor, first differential gearing driven by said motor and including a normally stationary first differential cage, an electromagnet having a movable armature, means for energizing both said electromagnet and said motor, a switch, a switch actuating spring carried by said armature, latch means for restraining said spring from actuating said switch whereby said armature stresses said spring when said electromagnet is energized, means for holding stationary one of the gears of said first differential gearing whereby said rst differential cage is rotated in a given direction, a second differential gear train including a second differential cage and connected between said driving motor and said rst diferential gearing, a ratchet dened on the :periphery of said second cage, solenoid means adapted to be energized after said electromagnet is operated and independently of said energizing means including a pawl for engaging said ratchet for controlling the movement of said second differential cage thereby to vary the rate of rotation of said rst differential cage, and means responsive to movement of said first differential cage to a predetermined position for tripping said latch means thereby to release said spring and actuate said switch.

19. A time delay relay, comprising an electric motor, differential gearing driven by said motor and including a normally stationary differential cage, an electromagnet having a movable armature, means for energizing both said electromagnet and said motor, an electric switch, a switch actuating spring carried by asid armature and tending to move therewith, latch means for restraining said spring whereby upon movement of said armature said spring is stressed in response to energization of said electromagnet, means for normally holding stationary one of the gears of said differential gearing independently of the operation of said electromagnet whereby said differential cage is rotated in a given direction during :periods when said motor is energized, said gear holding means preventing reverse rotation of said cage upon deenergization of said motor providing said cage has failed to move to a predetermined position, means responsive to movement of said cage to said predetermined position for tripping said latch means thereby to release said spring and actuate said switch, and means actuated by said spring simultaneously with actuation of said switch for deenergizing said motor and releasing said gear holding means, thereby to permit said cage to return to its initial position.

20. In a time delay relay means comprising an electric switch, an electric motor, differential gearing drivingly connected to said motor, an electro-magnet having a movable armature, means for energizing said electro-magnet and said motor, switch actuating energy storage means, means responsive to movement of said armature upon energization of said electro-magnet for storing energy in said energy storage means, latch means for maintaining energy stored in said energy storage means, means for holding stationary one of the elements of said differential gearing whereby a second element of said differential gearing is rotated in a given direction in response to operation of said motor, and means responsive to movement of said second element to a predetermined position for tripping said latch means thereby to release the energy stored in said energy storage means to actuate said switch.

ARTHUR B. POOLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,937,391 Schwegler Nov. 28, 1933 2,130,405 Andrews Sept. 20, 1938 2,312,077 Cowles Feb. 23, 1943 2,388,686 Mabig Nov. 13, 1945 2,496,310 Rabinow Feb. 7, 1950 2,526,445 Young Oct. 17, 1950