US2677029A - Time delay relay - Google Patents

Description

April 7, 1954 M. VAN VALKENBURGH 2,677,029

TIME DELAY RELAY Filed March 5, 1952 3 Sheets-Sheet 1 63 11:4; o 2d INVENTOR.

60 MERR/TT VAN VALKENBURGH Zlorazeys April 1954 M. VAN VALKENBURGH 2,677,029

TIME DELAY RELAY INVENTOR. J3 NERR/TT VAN I/ALKENBURGH April 1954 M. VAN VALKENBURGH 2,677,029

TIME DELAY RELAY Filed March 5, 1952 3 Sheets-Sheet 3 INVENTOR. MEPP/TT VAN VA LKENBL/PGH a7 orna ys Patented Apr. 27, 1954 TIME DELAY RELAY Merritt Van Valkenburgh, Upper Nyack, N. Y.,

assignor to M. H. Rhodes Incorporated, Hartford, '0onn., a corporation of Delaware Application March 5, 1952, Serial No. 274,910

(Cl. ZOO-97) Claims. 1

This invention relates to a relay having switch means, electromagnetic means associated with the switch means, and a timer device for delaying the operation of the switch means.

The aim of the invention is to provide a relay of this character having various features of novelty and advantage and which is particularly characterized by its adaptability to a wide variety of uses; by it flexibility in use in that it is capable of operation on direct or alternating currents at various voltages to control circuits of various sorts for various time cycles; by its dependability and accuracy in operation under widely varying conditions and influences to which it may be subjected such as extreme temperature changes, vibration, shock, etc.; by its ability to stand up under hard service; by its compactness, and by its simplicity in construction and arrangement and its economy in manufacture.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplifled in the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

In the accompanying drawings, wherein I have shown two embodiments which the present invention may take:

Figure 1 is an elevational view looking towards one side of a relay constructed in accordance with one embodiment of the invention, the cover of the casing being in longitudinal section;

Fig. 2 is a view looking at the right hand end of the relay as seen in Fig. 1, the end of the cover of the casing being broken away;

Fig. 3 is a view similar to Fig. 1 but looking at the other side of the relay;

Fig. 4 is a view similar to Fig. 2 but looking at the other end of the relay;

Figs. 5, 6, and '7 are horizontal sectional views taken through the relay, these views being respectively taken on substantially lines cc, bb, and cc of Fig. 1;

Fig. 8 is also a horizontal sectional view through the relay, this view being taken substantially on line d-d of Fig. 4;

Fig. 9 is a partial vertical sectional view, the same being taken on line e--e of Fig. 4;

Fig. 10 is a detail view of th switch arm and the cam assembly for controlling the same as viewed from below;

Fig. 11 is a detail view of the ratchet mechanism associated with the time device and as viewed from below;

Fig. 12 is a detail view showing the stem of the armature of the solenoid and parts associated therewith;

Fig. 13 is a view similar to Fig. 1 but showing another embodiment of the invention, the casi and certain other parts being omitted;

Fig. 14 is a lefthand end view of the structure shown in Fig. 13;

Fig. 15 is a top plan view thereof;

Fig. 16 is a horizontal sectional view taken substantially on line l6l6 of Fig. 14;

Fig. 1'? is a horizontal sectional view taken substantially on line |'l--ll of Fig. 13, the knockoff pin I I0 being shown in position to provide a maximum time cycle; a

Fig. 18 is a detail view of the ratchet mechanism shown in Fig. 16 but as viewed from below; and

Fig. 19 is a view similar to Fig. 17 but showin the pin I I0 adjusted to a position where a shorter time cycle is obtained.

As will be seen from the accompanying drawings, my improved relay comprises generally one or more solenoids or magnets, a single solenoid A being shown in the present instance, and switch means B controlled by a cam assembly C which is controlled by the solenoid and a timer device D in such manner that there is a time delay between th influencing of the solenoid and the opening or closing of the switch means. In the embodiment shown in Figs. 1 to 12, the cam assembly C is turned in one direction on the impulse stroke of the armature to open the switch and is turned in the opposite direction by a spring associated with the armature for moving the latter on its return stroke when the solenoid is deenergized. This arrangement, however, is shown by way of exemplification, it being understood that the switch may be closed on the impulse stroke of the armature and opened on its return stroke thereof and that the timer device may be effective for delaying operation of the switch fol lowing the impulse strok of the armature.

Referring to the embodiment shown in Figs. 1

to 12, the instrumentalities A, B, C and D may be enclosed in a housing or casing E which, in the present instance, includes a base it and a boxlike cover [6. The base and cover may be made of suitable insulating material, such as plastic. The various specified mechanisms or devices are carried by a suitable chassis secured to the base l5. While this chassis may take any suitable form, it is here shown as comprising a rectangular frame ll within which the coil 39 of the solenoid is mounted, a bracket 58 secured to one end of the frame ll and forming, in part, a support for the cam assembly and the timer device D; and a bracket l9 secured to the top of the frame I! and to which the boxlike cover It is secured as by means of a screw 20. The margin of the base I5 is rabbeted as at 2i so as to closely re ceive the lower edge of the cover and thus form a substantially dustproof joint. Arising from one longitudinal edge of the base it is an upstanding flange or wall 22 to which is secured the various electrical terminals associated with the solenoid and the switch means. One side Wall of the cover I6 has an opening for accommodating this flange 22 and. the abutting edges of the opening and flange are complementarily rabbeted as at 23.

Referring now more specifically to the solenoid, the same is here shown as comprising a coil 33 having a tubular core 35 secured in and extending beyond the forward end wall 32 of the frame l1. Fitting in the other end of the core is a plug 33 which is secured to the other end wall ti l of the frame ll. The frame ll is secured to the base !5 by bolts 35. The solenoid has an armature 36 slidably fitting in the core 35, and this armature has a stem 36' extending beyond the open end of the core. About this stem and adapted to abut against the open end of the core is a collar 37. About the stem 36 and interposed between the collar 31 and a second collar 38 is a coiled spring 39 for returning the armature to the normal position shown in the drawings upon de-energization of the solenoid. The

collar 33 is slidably mounted on the stem 35. A

pin 4! is associated with the ratchet mechanism of the timer device D and the cam assembly 0, as hereinafter explained more in detail. The lower end of this pin engages between the collars 38 and 40. The collar 49 forms an abutting shoulder for the pin and abuts against a nut 42 adjustably screwed onto the free threaded end of the stem 36. The body portion of the armature and the stem 36 thereof may be chromium plated and polished so that the armature may slide within the core and the collars may relatively slide with respect to the stern without sticking or undue friction in the absence of a lubricant. By arranging the collars 33 and 4?! on the stem 36 with the pin 41 engaging therebetween, the necessity of providing a guiding support for the free end of the stem is eliminated, the armature may turn about its axis without affecting the operation of the apparatus, and lubrication is eliminated, all of which provides a very simple, eifective structure permitting the relay to function over wide temperature variations. It has been found that the mechanism will operate with substantially like accuracy between temperatures ranging from minus 76 to plus 185 F., and this would not be possible if the contacting sliding surfaces were lubricated as the consistency of the lubricant would change depending upon the temperature to which it would be subjected. There may also be or sloping edge 76.

4 slidably mounted on the stem of the armature a stop sleeve or collar 44, the purpose of which will be later described. The ends of the coil 30 are connected to terminals 43 carried by the flange 22.

Referring now to the switching means 13, the same comprises, in the present illustrative disclosure, a switch arm 50 positioned between a pair of spring fingers 51 52. The switch arm and fingers are secured to a laminated insulator block 53 which is secured to the base [5 as by means of a bracket 53 and bolts 54. The switch arm, adjacent its free end, carries a double contact 55 adapted to alternately engage contacts 56 and 5? respectively secured to the fingers 5| and 52 adjacent the free ends thereof. The fin-- ger til, the switch arm 50, and the finger 52 may be respectively connected to the terminals 58,

and Hit of the power circuit.

The switch arm is moved from one position to the other by the cam assembly C acting through a lever or arm 51 which is pivoted at one end on a pivot 62 fixed to and depending from the bracket H3. The lever (ii, at its free end, has a pair of depending cylindrical studs E53 formed of insulating material, and these studs are in straddling relation to the free end of the switch arm 56 beyond the contact 55 carried thereby. Depending from the lever B! and located between the ends thereof is a follower pin 54 which is resiliently urged towards the periphery of the cam assembly C by a spring coiled about the pivot pin 62 and having its opposite ends respectively anchored to the lever 6i and the bracket 8.

The cam assembly C comprises a cam disk Ill fixed to a vertical shaft "H, and a supplemental disk 52 journaled on the shaft l! for limited rotary movement with respect to the disk 10. The shaft H is journaled in a vertical sleeve 6'! carried by the bracket [8. Fixed to the upper end of this shaft is an arm 68 in which the pin ll is fixed and which pin, as previously stated, engages between the collars 38 and it of the armature 3B. In order to permit of lost motion be tween the disks i0 and 12, the disk it has a slot l3 into which extends a pin l4 depending from the disk 10. The disk "iii has a notch with a generally radially extending edge "Li and a cam The disk i2 is of slightly larger diameter than the disk It and it has a notch with an edge ll corresponding to, and adapted to register with, the edge 15 when the pin as is engaged in the bottom of the notches, and a generally radially extending edge "it. With this arrangement, when the cam assembly is rotated counterclockwise with respect to Fig. 8 (and which movement, in the present instance, takes place on the impulse stroke of the armature of the solenoid), the cam edge is cams the pin 64 outwardly so as to move the contact 55 out of engagement with the contact 51 and into engagement with the contact 58, and then the pin engages against the periphery of the disk 12. On reverse rotation of the cam disk it (which takes place as the armature is moved to the left in Fig. 7 under the influence of the spring 39) the disk 12 is held stationary (due to the arrangement of the pin 64 against the periphery thereof) until the pin 14 engages the other end of the slot 13 and then the two disks rotate together until the pin 64 rides oil of the periphery of the disk 12 and into the notch in the disk '50 to the position shown in Figs. 8 and 10, whereupon contact 55 is moved out of engagement with contact 56 and into engagement with contact 51.

Referring now to the timer device D, the same is shown, for purposes of exemplification, as comprising a clock mechanism provided with an arbor 85 journaled in bearings provided in frame plates 86 and s! maintained in spaced relation by pillars 88. The arbor is in general axial alignment with the shaft II. Fixed to the arbor is a main gear 89 which is connected through a gear train 90 to the escapement wheel 9i. C0- operating with a teeth of this escapement wheel are the pins 92 of the usual pallet wheel 93 whereby the speed at which the clock arbor is driven in one direction is controlled. Fixed to the arbor 85, and located beneath the lower frame plate 81, is a ratchet wheel 95. Cooperating with the serrated edge of this ratchet wheel are two spring pressed pawls 95 (see Fig. 11) carried by an arm 91 journaled on the lower end of the arbor 85. In the embodiment shown in Figs. 1 to 12, the pawl carrying arm 97 has between its ends a hole 98 through which closely extends the upper end of the pin 4I so that the pawl carrying arm 91 and the arm I58 swing substantially in unison.

The operation of the device shown in Figs. 1 to 12 will be readily understood from the foregoing description taken in connection with the following explanation: It may be assumed that when the parts are in the position shown in the drawings, the switch means B is in closed condition and no current is passing through the coil of the solenoid. Upon energization of the solenoid, the armature 36 thereof will move on its impulse stroke, that is, towards the right referring to Figs. 6 and 7, and, due to the engagement of the collar 49 with the pin 4I, the cam assembly will be rotated counterclockwise, with respect to Fig. 8, with the result that the follower pin 64 will ride out of the notches of the disks iii and I2 of the cam assembly thereby moving the switch arm 50 from the position shown in Fig. 8 to a position where the contacts 55 and 56 are engaged. At the same time, the pawl carrying arm 9'! is moved on its inoperative stroke, that is, counterclockwise with respect to Fig. 6 and clockwise with respect to Fig. 11, and dur ing such movement, the pawls will ratchet over the ratchet wheel 95. These parts will retain these positions until the solenoid is deenergized. Upon stoppage of the armature during its operative stroke, there is a tendency for the pin 4|, the arm $3, the cam assembly, and the ratchet lever E! to continue to move due to their momenturn, and if this were allowed, overtiming would result and the timing would vary widely. In order to prevent this, the stop collar 44 is provided on the armature stem between the collars 3i and 38. This stop collar is of such length that, when it is engaged between the collars 31 and 38, the collar 38 will be spaced from the collar 40 at a distance equal to the diameter of the end of the pin II engaging therebetween. That is to say, when the armature is in its inner or righthand position, the collars 38 and 49 will bear the same position relative to one another that they do when the armature is in the outer or l fthand position shown in Figs. '7 and 12. Upon de-energization of the solenoid, the spring 39 associated with the armature thereof will move the armature on its return stroke, that is, towards the left referring to Figs. 6 and 7, and, due to the fact that this spring urges the collar 38 against the pin II, the cam assembly is driven in a clockwise direction, with respect to Figs. 6 to 8. The speed at which the cam assembly is thus driven is, however, controlled by the timer device so that there is a predetermined time delay between the de-energization of the solenoid and the operation of the switch. It is observed that on the return stroke of the armature, the spring 39 drives the clock train through the collar 33, pin II, pawl carrying arm 91, pawls 95, and the ratchet wheel 95, and the escapement, comprising the gear train 90, the escapement wheel 91 and the pallet wheel 93, determines the speed at which the clock mechanism is driven.

Referring now to the embodiment of the invention shown in Figs. 13 to 19, inclusive, the arrangement is similar to that just described but provision is made for changing the time cycle at will. In these figures, the solenoid is shown only in part, and the cam assembly and the switch means are not illustrated, it being understood that these instrumentalities may be similar to those illustrated in Figs. 1 to 12. Where the parts correspond to similar parts of the previous embodiment, like reference numerals are employed but the numerals are primed.

In this latter embodiment of the invention, the pin 4|, instead of passing through an open ing in the ratchet pawl carrying arm 91 is adapted to engage that edge of the arm which faces away from the coil 30'. The crank arm 58', which carries the pin 4|, is provided at its free end with a tooth I00 with which cooperates a latch IilI pivotally carried by the arm 91. The crank arm 68' is fixed to the vertical shaft ll, the lower end of which carries the cam assembly as in the preceding embodiment. The lower end of the pen 4| engages between the collars 33 and 46' on the stem 36 as in the preceding embodiment. The timer device D is similar to that previously described.

The latch II is pivoted on the lower end of one of the studs I02 employed for pivoting one of the pawls 96 to the arm 91'. This latch is in the form of a bell crank, one arm I04 of which is provided with a tooth I05 which is adapted to cooperate with the tooth I00 on the crank arm 68 as shown most clearly in Fig. 1'7. On the inner edge of the arm I04 is an extension I66 adapted to engage a lug IIl'I depending from the arm 91' for the purpose of limiting the inward swinging movement of the latch. The other arm I08 of the latch is adapted to engage an adjustable knock-ofi pin IIO so as to release the latch from the crank arm at the termination of the selected time period. The latch is normally urged clockwise with respect to Fig. 17 by a spring I I I.

The latch trip or knock-off pin III] is carried by an indicator arm II2 which is pivoted to a stud II3 on an indicator plate H4. The plate H4 is secured to the top plate 86 of the timer mechanism, and the pivot stud II3 is in alignment with the arbor of the timer. The plate H4 is offset upwardly between its ends so as to accommodate between itself and the plate 86 the indicator arm. One edge of the plate I I4 is pro vided with a scale which, in the present instance, is formed by notching the plate as at H5. The outer end of the indicator arm is provided with a pointer II6 for cooperation with this scale. For the purpose of locking the indicator arm in any desired position of adjustment, the plate i H is provided with an arcuate slot I H which accommodates a lock screw or bolt II8 carried by the indicator arm.

The operation of the device shown in Figs. 13

to 18, inclusive, is briefly as follows: Figs. 13 to 18, inclusive, show parts in the normal position corresponding to the position of the parts shown in Figs. 3 to 8, inclusive, of the first embodiments The knock-off pin H is shown in position to provide the maximum time cycle, pointer H6 or indicator arm H2 being set at the last lefthand division on scale H5 (see Fig. In this position, knock-oil pin H0 has no influence on latch lfll so that the tooth I05 on the latch remains in engagement with the tooth ill!) on arm 68 as shown by full lines in Fig. 17. In this relationship, upon energization of the solenoid, the armature thereof will move to the right and collar will move pin 4| to the right so that the cam assembly will be rotated to move contact 55 out of engagement with contact 51 and into engagement with contact 56 as in the preceding embodiment. At the same time, due to the engagement of pin 41' against the opposed edge of the pawl carrying arm 91, this arm will be moved to the right, referring to Fig. 16 and the ratchet pawls 96 will ratchet over the wheel 89'. Upon de-energization of the solenoid, the spring 39 will move the collar 38 to the left, urging pin 4| on crank 68 clockwise and through engagement of tooth we on the latter with tooth H35 on latch 10! inducing similar rotation of pawl carrying arm 91 at a rate governed by the timer device through the engagement of pawls 96 with ratchet wheel 89' on the latter assembly. Since in the adjustment shown in Figs. 16 and i7, knock-off pin H0 is so far to the left that it has no influence upon latch [0| before the clockwise rotation of arm 68' and associated cam assembly has reached the normal position allowing contact 55 to move back out of engagement with contact 56 and into engagement with contact til again, tooth I05 on latch l0l will remain in en gagement with tooth I00 on arm 68 throughout the entire clockwise movement of the latter and thus with this adjustment the rate of clockwise movement of arm 68 and its associated cam assembly will be governed by the timer device throughout its complete operating arc.

teferring now to Fig. 19, the knock-off pin I it is shown in a position corresponding to an inter mediate adjustment of the pointer M5 on the scale i l5 so that the time cycle is less than maxi mum. In this figure, the arm 68 and the latch Elli are shown by dash lines in their normal positions. Further, these parts are shown by full or solid lines in the positions which they have at the end of the timing cycle, that is, just as the tooth M5 on the latch is disengaged from the tooth int on the arm 68 during the movement of the armature under the influence of the spring 352, the solenoid having been de-energized. Starting with the parts in their normal positions, upon energization of the solenoid, the armature thereof will move to the right causing the collar it to move the pin t! to the right so that the cam assembly will be rotated to close the switch as in the preceding embodiment. As the pin 41 moves to the right, the arm 68' is moved counterclockwise, and during such movement, the cam surface H9 on the back of the tooth I it will enease the cam surface :12!) on the back of the tooth H15 so that the latch Iill will be cammed out and then, when the teeth are in alignment, the tooth I65 on the latch will snap quickly and positively into engagement with the tooth Hill on the arm 6%). Following this, the pin 4| will immediately strike the opposed edge of pawl carrying arm 91', whereupon this arm will move to 8 the right and ratchet pawls 96' will ratchet over the wheel 89'.

Still referring to Fig. 19, upon de-energization of the solenoid, the spring 39' will move the crank arm ear and the pawl carrying arm 9'! clockwise as a unit at a rate governed by the timer device in the manner previously described, but with the setting of the knock-off pin shown in Fig. 19, this pin is effective to disengage the latch Ill! from the crank arm at an intermediate point in operating arc of the latter, depending upon the selected time cycle, whereupon the spring 39' will drive the arm 88', together with its associated cam assembly, with great rapidity through the remainder of its operating arc to effect the same switch action as previously described.

It will be seen that, upon engagement of the arm [0a of the latch with the knock-off pin, the latch is moved counterclockwise about its pivot 1B2 until the tooth of the latch is disengaged from the tooth I00 of the arm 88. During this time, some reaction is transmitted through the latch it! to the pawl carrying arm 91' (which is free to move counterclockwise as the pawls 96 may ratchet over the ratchet wheel 89) with the result that the arm 97 will move counterclockwise from the dash line position to the dash and dot line position shown in Fig. 19, and the latch [ill will assume the normal position shown in broken lines. In this position, the latch I0! is urged as far as the knock-off pin will allow, clockwise towards the stop l0! by the spring Ill. It is obvious that the time cycle may be varied by adjustin the indicator arm H2 and the knock-off pin i it carried thereby.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of th scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. In a time delay relay, electromagnetic means having an armature provided with a shoulder, a slidable collar on said armature, a spring about said armature and bearing against said slidable collar and. arranged to be compressed upon energization of the electromagnetic means and to move the armature outwardly upon de-energization 01 the electromagnetic means, a switch, a cam controlling said switch, an escapement clock mechanism for controlling the speed of rotation of said cam in one direction, and a pin engaging between said collar and shoulder and operativels connected to said cam and said clock mechanism.

2. in a time delay relay, electromagnetic means having a coil provided with a tubular core and an armature slidably fitting in the core and havin a stem extending therebeyond, said armature having a polished plated surface, a collar about said stern and abutting the end of said core, a shoulder on said armature adjacent the free end of said stem, a slidable collar on said stem between said first mentioned collar and shoulder, a spring about said armature between said collars and arranged to be compressed upon energization of the electromagnetic means to move th armature outwardly upon de-energization of the electromagnetic means, a switch, a cam controlling said switch and rotatable in opposite directions, an escapement clock mechanism for controllin the speed of rotation of said cam in one direction, and a pin engaging between said second mentioned collar and shoulder and operatively connected to said cam and said clock mechanism.

3. In a time delay relay, electromagnetic means having a slidable armature provided with a shoulder, a slidable collar on the armature, a spring about the armature and bearing against said slidable collar and arranged to be compressed upon energization of said electromagnetic means and to move said armature outwardly upon deenergization of the electromagnetic means, a switch, a cam controlling said switch and rotatable in opposite directions, an escapement clock mechanism for controlling the speed of rotation of the cam in one direction, a pin engaging between said shoulder and slidable collar and connected to said cam, an arm connected to said pin, and a pawl and ratchet connection between said arm and said escapement clock mechanism.

4. In a time delay relay, electromagnetic means having an armature provided with a shoulder, a slidable collar on said armature, a spring about said armature and bearing against said slidable collar and arranged to be compressed on inward movement of the armature upon energization of the electromagnetic means to move the armature outwardly upon deenergization of the electromagnetic means, a switch, a cam controlling said switch, an escapement clock mechanism for controlling the speed of rotation of said cam in one direction, a pin engaging between said collar and shoulder and operatively connected to said cam and said clock mechanism, and means for positively limiting the extent of movement of said slidable collar upon inward movement of the armature whereby to prevent overthrow of the cam and clock mechanism.

5. In a time delay relay, electromagnetic means having a coil provided with a tubular core and an armature slidably fitting in the core and having a stem extending therebeyond, said armature having a polished surface, a collar about said stem and abutting the end of said core, a shoulder on said armature adjacent the free end of said stem, a slidable collar on said stem between said first mentioned collar and shoulder, a stop collar on said stem between said first and second collars and arranged to limit the extent of movement of the second mentioned collar when the armature is moved inwardly, a spring about said armature between said first and second mentioned collars and arranged to be compressed upon energization of the electromagnetic means to move the armature outwardly upon deenergization of the electromagnetic means, a switch, a cam controlling said switch and rotatable in opposite directions, an escapement clack mechanism for controlling the speed of rotation of said cam in one direction, and a pin engaging between said second mentioned collar and shoulder and operatively connected to said cam and said clock mechanism.

6. In a time delay relay, electromagnetic means having an armature, a switch, a cam controlling said switch, an arm carried by said cam means, an escapement clock mechanism, ratchet means operatively associated with said escape-- ment mechanism, an arm carried by said ratchet means, said arms being relatively movable with respect to each other, means actuated by said armature for moving said arms in one direction upon energization of the electromagnetic means, latch means carried by one arm and interengaging the other arm to effect movement of said arms in unison in a direction opposite to said one direction upon de-energization of said electromagnetic means and under control of said escapement mechanism, and means for tripping said latch means at a selected point in their said opposite direction movement to disengage said arms so that continued movement of said cam arm by the armature can ensue free from control of said escapement mechanism.

'7. In a time delay relay, electromagnetic means having an armature movable between two positions, a switch having a member movable between two positions, a cam for controlling said switch member, an operative connection between said armature and cam through which the latter is rotated in one direction when said armature is moved into one position, an escapement clock mechanism for controlling the speed of rotation of said cam in the opposite direction during movement of said armature to its other position, spring means for driving said clock mechanism and arranged to be placed under compression by said armature when said electromagnetic means is energized, a disengageable latch connection between said clock mechanism and cam, and adjustable trip means for said latch connection.

8. In a time delay relay, electromagnetic means having an armature movable between two positions, a switch, a cam for controlling said switch, an operative connection between said armature and cam and through which the latter is rotated in opposite directions upon energization and deenergization of said electromagnetic means, an escapement clock mechanism for controlling the speed of rotation of said cam in one direction, a pivoted arm operatively associated with said armature and movable in opposite directions upon energization and de-energization of the electromagnetic means, a ratchet associated with said clock mechanism, a pawl carried by said arm and cooperating with said ratchet, a latch pivoted to said arm and engageable with said operative connection upon movement of the armature in one direction, and adjustable means for tripping said latch.

9. In a time delay relay, electromagnetic means having an armature provided with a shoulder, a slidable collar on said armature, a switch, a cam controlling said switch and having a crank arm connected thereto, a tooth on said arm, a pin carried by said arm and engaging between said collar and shoulder, an escapement clock mechanism for controlling the speed of rotation of said cam in one direction, a pivoted arm, a ratchet associated with said clock mechanism, a ratchet pawl carried by said pivoted arm and cooperating with said ratchet, said pin being arranged to engage said pivoted arm to move the same in a direction in which the pawl will ratchet over said ratchet, a pivoted latch carried by said pivoted arm and arranged to engage said tooth, an adjustable pin for disengaging said latch from said tooth, and spring means for moving said collar outwardly and said pivoted arm upon outward movement of said armature.

19. In a time delay relay, electromagnetic means having an armature movable between two positions, a switch having a member movable between two positions, a rotatable shaft, a cam 11' on said shaft for controlling said switch memher, a crank arm secured to said shaft, a pin carried by said crank arm and operatively connected to said armature and through which said shaft and cam are rotated in one direction when said armature is moved into one position, an escapement clock mechanism for controlling the speed of rotation of said cam in the other direction, a pivoted arm operatively connected to said pin and through which said crank arm is moved, a ratchet associated with said clock mechanism, a pawl carried by said pivoted arm and arranged to ratchet over said ratchet when said armature is moved into the first mentioned position and 12 adapted to positively engage the ratchet when the armature is moved to its other position, and spring means for driving said clock mechanism and arranged to be placed under compression by said armature when said electromagnetic means is energized.

References Cited in the file of this patent UNITED STATES PATENTS 10 Number Name Date 2,064,656 Goif Dec. 15, 1936 2,235,273 Wheelock et a1 Mar. 18, 1941 2,392,183 Phillimore Jan. 1, 1946

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