US2839624A

US2839624A - Short interval time switch

Info

Publication number: US2839624A
Application number: US424867A
Authority: US
Inventors: Stolle Anthony Dan
Original assignee: International Register Co
Current assignee: International Register Co
Priority date: 1954-04-22
Filing date: 1954-04-22
Publication date: 1958-06-17
Anticipated expiration: 1975-06-17

Description

' June 17, 1958 A. D. STOLLE 2,839,624

SHORT INTERVAL TIME SWITCH 3 Sheets-Sheet 1 Filed April 22. 1954 INVENTOR.

$23720@flan .i/blle,

June 17, 1958 A. D. STOLLE 2,839,624

SHORT INTERVAL TIME SWITCH Filed April 22. 1954 5 Sheets-Sheet 2 June 17, 1958 A. D. STOLLE 2,839,624

, SHORT INTERVAL TIME SWITCH Filed April 22, 1954 5 Sheets-Sheet 5 INVENTOR. 170/2 55056,

a l f-he ister Cornpnn Chicago Ill. a cor oration I WI I) 3 3 or mots Ap-piication April 22, 1954, Serial No, 424,867

9 illuirns. (Cl. filth-38) The present invention relates to a short interval time switch of the type adapted to perform a short interval .lWiiClliHg operation at any preselected time or times of the ni ht or day. This switch is preferably of the cyclical type adapted to automatically repeat these one or more short interval switcl'ting operations at the same preselected time or times of the night or day without requiring manteal resetting.

in the following description of one preferred embodiment of my invention 1 have .used the expression short interval to indicate selected time intervals ranging from minutes to 60 minutes. However, the invention is not limited to time intervals of these specific proportions.

The short interval switching operation can be a switch opening operation or a switch closing operation, or both operations occurring simultaneously at separate contacts, according to the switching contacts provided and the circuit connections to these contacts.

One of the objects of the invention is to provide an improved construction of time switch in which an automatically operated switch actuating member is constantly spring biased in one direction so that it tends constantly to remain in a first or normal position, corresponding to one condition of the switch contacts; and in which manually settable trippers, which have been preset in certain timed positions on a time driven dial, are arranged to engage this switch actuating member at the selected time or times and to forcibly move the switch actuating member into a second position in opposition to its spring bias, in which second position the switch actuating member performs a so-called short interval switching operation for so long as the time driven tripper holds the t .tch actuating member in this second position against "1g bias. linother object of the invention is to provide an im- ---ved time switch of the above general description in ch each tripper on the time driven dial embodies imd adjusting means for adjusting the duration of this led short-interval switching operation; viz, such as ljusting the length of the time driven travel during t the tripper is effective to hold the switch actuating in nber in its second position against the action of the biasing spring.

Another object of the invention is to provide .a short interval repeating cycle time switch that can perform a large number of. short-interval switching operations during the course of the day or night or both, each which switching operations can be separately set to start at any preselected time, nd each of which switching operations can also be separately set to be of different time duration. For example, a grocery store owner decides that his ating system wi'il function more effectively if it rested three times a day for different intervals, such as for 66 minutes in the early morning, minutes at noon, and minutes in the evening. He simply sets one tripper to minutes, another to 20 :minutes and a third to 35 minutes. These trippers are then slipped on the States Patent 0 2,839,624 Patented June 17, 1958 time driven dial and are set at the respective times of the day or night that the defrost cycles are to occur.

My improved time switch is useful for a wide variety of time control situations, such as for the automatic time control of automatic poultry feeders, ventilating systems, attic and exhaust fans, compressors, sprinkling systems, coal stokers, intermittently pumping water wells, motors, valves, industrial process timing, etc.

The construction herein disclosed embodies improve ments upon the construction of timing mechanism disclosed in the copending application of William P. Gallagher and myself, Serial No. 172,586, filed July 7, 1950, which issued on March 9, 1954, as Patent No. 2,671,830.

Other objects, features and advantages of the invention will be apparent from the following detail description of one preferred embodiment thereof. In the accom panying drawings illustrating such embodiment:

Figure l is a front, elevational view showing the time switch mounted in a preferred form of housing, with the front door of the housing illustrated in its open position.

Figure 2 is an exploded perspective view of the various parts of the time switch.

Figure 3 is a view of the switch actuating mechanism taken on a plane directly behind the time driven dial, the front switch actuating arm being shown in its first or normal position in which it is normally maintained by its biasing spring.

Figure 4 is a view similar to Figure 3, showing the switch actuating arm swung to its second position by one of the trippers on the time driven dial, in the performance of one of the short interval switching operations.

Figure 5 is a vertical transverse sectional view taken approximately on the plane of the line 5-5 of Figure 3.

Figure 6 is a horizontal transverse sectional view taken approximately on the plane of the line 6-6 of Figure 3.

Figures 7 and 8 are fragmentary front detail view of the switch operating mechanism showing the action of the over-center snap spring therein for effecting the quick make and quick break of the switch contacts,

Figure 9 is a rear elevational view of one embodiment of switch and switch operating mechanism, typical load circuit connections being schematically illustrated in this figure,

Figure 10 is a front elevational view on an enlarged scale showing one of the manually settable trippers for adjustable mounting on the time dial, these trippers embodying the improved short interval timing adjustment,

Figure 11 is a side elevational view of such tripper on the same enlarged scale as Figure 10, showing its adjust ably clamped mounting on the time dial,

Figure 12 is a vertical sectional view through the tripper taken approximately on the plane of the line 12-12 of Figure 10,

Figure 13 is a detail sectional view, also on an enlarged scale, showing substantially the full length of cam dwell between the tripper cam and the switch actuating mechanism when the tripper cam is set for its maximum length of short interval timing adjustment,

Figure 14 is a view similar to Figure 13 showing the relatively short length of cam dwell when the tripper cam is set for substantially its shortest length of timing adjustment, and

Figures 15 and 16 are perspective views of the off and on types of manually settable trippers which may be mounted on the time driven dial if it is desired to convert my invention into a long interval time switch.

An improved time switch constructed in accordance with this invention comprises a mounting plate A on which is mounted a switch operating mechanism 13 actuated by a motor driven control mechanism C for opening and closing switch apparatus D, the latter also being mounted on the mounting plate A. All of the foregoing is supported in a housing B so formed as to permit easy placing and removal thereof.

The mounting plate A is a flat piece of metal which is notched out at to permit the convenient attachment of a motor 21, this mounting plate also being notched or recessed at 22 and 23 to respectively span a hinge 24 for the housing cover 25, and to receive the free end of a housing retaining spring 26, as more fully disclosed in the aforesaid patent application. A V-shaped extension 27 projecting downwardly from the lower portion of the mounting plate A provides a mounting for the switch operating mechanism B. Projecting from the back of plate 'A are posts 28 to which the motor 21 is attached, and projecting from the front of said plate are

stud shafts

29, 30, 31 and 32, which provide for the appropriate journalling of the motor driven time control mechanism C and the switch operating mechanism B, as will be described presently.

The motor 21 herein shown is of the synchronous type conventionally used withthis type of switch mechanism.

The switch operating mechanism B comprises a pair of

switch actuating arms

33 and 34 swingably mounted on the mounting plate A. The arm 33 is disposed directly adjacent the mounting plate, and the arm 34 is disposed directly in front of the arm 33. All automatic actuation and all manual actuation of the ,switch is effected by swinging movement of the front switch actuating arm 34. This arm 34 is normally held biased into a normal position by a tension spring 135 connected in tension between said arm and the left hand edge of mounting plate A, as will be later described. In the automatic operation of the switch, the arm 34 is adapted to be pivotally swung in the opposite direction from the direction of its spring bias at the preselected control time or times through the action of one or more manually

settable trippers

35a, 35b, 35c, etc. mounted on the time control mechanism C. An over-center snap action is imparted from the outer switch actuating arm 34 to the inner switch actuating arm 33 through the instrumentality of a U-shaped spring 37 interposed between

stake pins

38 and 39 on the

respective arms

33 and 34, as will be later described. 7

As above remarked, these two

switch actuating arms

33 and 34 are swingably mounted in superimposed relationship on the front side of the mounting plate A,

the front arm 34 being pivotally mounted on the lower stud shaft 31 projecting forwardly from the mounting plate, and the rear switch actuating arm 33 carrying its own pivot shaft 40 which is journalled in a bushing 40' projecting from the rear of the mounting plate. A time gear 41 and a dial 42 of the motor operated control mechanism C are journalled on the main stud shaft 29, which is disposed substantially above and slightly 1 to one side of stud shaft 31. That is to say, the

shafts

31 and 40 for pivotally mounting the

switch actuating arms

33 and 34 are disposed below and slightly to one side of the vertical plane of the main stud shaft 29, as

indicated by the line x-x passing through the axes of the

pivot shafts

31 and 40 in Figures 7 and 8.

The rear switch actuating arm 33 is formed with a socket 43 at its lower end (Figure 5) which is adapted to receive a pin 44 projecting forwardly from a switch actuating cam 45 arranged to operate the switch contacts. The rear switch actuating arm 33 is provided with an arcuate slot 31 for accommodating the stationary stud shaft 31, this arcuate slot permitting said rear arm 33. to swing through a suflicient arc to effect the desired oscillation of the switch operating cam 45 between its two opposite positions.

The front switch actuating arm 34 mounts a hub 46 which is press fitted or otherwise secured in a hole in the arm,this hub 46 serving as'a long pivot hub or hearing for rotatably mounting the switch actuating arm Cit 4 on the stud shaft 31. A removable snap type of C washer 46' (Figure 5) engages in a groove in the outer end of the stud shaft 31 and retains the hub 46 in place on said shaft. Also secured to the front switch actuating arm 34 is another hub 47 which is likewise press fitted or otherwise secured in a hole in the arm 34 directly alongside the hub 46. The latter hub 47 mounts a plate 48 providing outer and inner cam points or shoulders 49 and 50 respectively (Figures 3 and 4). The outer tripping shoulder 49 on this plate 48 is adapted to be engaged by the

successive trippers

35a, 35b, 350, etc. mounted on the time driven dial 42 for automatically swinging this front actuating arm 34 in a clockwise direction against the tension of the biasing spring 135 for performing the automatic switching functions. This front arm 34 is formed with an arcuate upper edge which is recessed at 51 to form a fork, the ends of which fork are bent down to provide right and left shoulders or stop

lugs

52 and 53 adapted to strike the sides of the stationary stud shaft 29 and thus establish the end limits of the swinging movement of the switch actuating arm 34. As will be later described, one end of the switch arm retracting spring 135 is hooked to the left hand stop lug 53. At its lower end this switch actuating arm is also formed with a forwardly and downwardly offset extension 54 which projects downwardly beyond the periphery of the time driven dial 42 and the trippers 35a, 3512, etc. carried thereby. This tongue or arm 54 functions as a lever for manually operating the switch, and on the front face thereof are stamped or inscribed the words Off and On, together with associated arrows indicating the direction of throw of this manually operated lever 54.

As will be apparent from Figures 2 and 5, the upper stake pin 38 is mounted on the rear switch actuating arm 33 and extends through a slot 55 in the front arm 34; whereas the lower stake pin 39 is mounted on the front arm 34 and extends through a slot 56 in the rear arm 33. The U-shaped spring 37 has the ends of the parallel portions thereof crimped, as shown at 57, in which crimps the

pins

38 and 39 are received to mount the spring 37 in operative relationship between the

arms

33 and 34. These two

stake pins

38 and 39, against which the ends of the U-shaped compression spring 37 react in an outward direction, swing in non-concentric, nonintersecting arcs, indicated in dotted lines at y and z in Figures 7 and 8. The compression spring 37 exerts a constant spreading force tending to separate the

pins

38 and 39. The positioning and spacing of these

pins

38 and 39 on the

members

33 and 34 are such that in the opposite swinging of the outer actuating arm 34, the pin 39 carried by this outer arm is oppositely moved across the line xx, which passes through the axes of the

stud shafts

31 and 40 of the

respective arm members

34 and 33. This results in the other spring reaction pin 38, which is carried by the inner actuating arm 33, being snapped across the line xx to the opposite side, thus effecting a snap throw of the actuated arm 33, which in turn is transmitted to the switch cam 45 for effecting a quick make and break of the switch contacts.

The motor-driven control mechanism C for the switch operating mechanism B comprises the interconnected time wheel 41 and dial 42, the gearing 58, and the

trippers

35a, 35b, etc. The time gear 41 and dial 42 are secured in fixed axial relationship upon a collar 59 which is slidably mounted on the main stud shaft 29. This axially slidable assembly is normally urged rearwardly by a compression spring 60 (Figure 5) so as to normally to midnight and from midnight to noon; together with the Morning, Afternoon, Evening," and After Midnight time divisions; all adapted for registration with a stationary downwardly extending pointer 63. The dial is also provided with instructions as to how to set the dial to make it agree with the true time when the device is first put into operation. The pointer 63 is stationarily secured to the front end of the pivot stud 29 by a mounting screw 64. Adjacent its outer periphery, the dial 42 is embossed to form an arcuate-shaped circumferential head 42', which provides support for the

trippers

35a, 35b, etc.

The gearing 58 is of conventional

form comprising gears

61, 65 and 66, 67. The motor pinion 62 meshes with large gear 66 which carries pinion 67. This pinion 67 meshes with large gear 65 which carries pinion 61. Pinion 61 normally drives the gear 41 which revolves the time driven dial 42. This gearing is sized and arranged so as to revolve the dial 42 once in twenty-four hours.

Referring again to the axially shiftable mounting of the dial 42, it will be seen from Figure that the spring 60 embraces the outer end of the stud shaft 29 and is interposed between th end of the collar 59 and the stationary pointer 63 which, as previously described, is secured to the end of the stud shaft 29 by a screw 64. The spring 60 thus permits an axial shifting of the interconnected time gear 41 and dial d2 so as to disengage the time gear 41 from engagement with the pinion 61, where by to allow the interconnected time gear and dial to be rotated for the purpose of setting the dial 42 in any desired position with respect to the pointer 63. This outward axial shifting of the interconnected time gear 41 and dial 42 also shifts the manually settable trippers a, 35b, etc. forwardly from the path which intersects the shoulder 49 on the cam member 48. Hence, the dial 42 can be unmeshed and rotated to a new position in the setting of the device, even after the time cycle established by the positions of the trippers 35a, 3515, etc. has been set up on the dial. It will be understood that the dial 42 is given its proper time setting when the time switch is initially installed; also following any lengthy interruption of current supply to the synchronous motor 21.

The switch apparatus D is mounted in its entirety on an insulating panel 75. The switch apparatus preferably comprises two contact springs as and 76' arranged to respond to the rotative oscillation of the switch actuating cam 45. The upper switch blade 76 carries a movable contact 77 adapted to engage a cooperating stationary contact 755, and the lower switch blade 76' carries a movable contact 77 adapted to engage a cooperating stationary contact 78. The fixed ends of the switch blades 76, 76' are riveted to terminal posts '79 which have staked or riveted attachment to the insulating panel "75. The stationary contacts 78, '78 are secured to generally similar terminal posts 7")" which are also riveted or staked to the insulating panel. The front ends of these terminal posts carry the usual terminal post screws tit) and St) for connecting the conductors thereto. The insulating panel 75 is also provided with a neutral binding post 81. Conductors 82 and 83 lead from one of the terminal posts 79 and from the neutral binding post 81 to the motor 21. The supply circuit is adapted to be connected to these two last-mentioned terminal posts. As illustrated in the fragmentary circuit diagram of Figure 9, the above-described arrangement of switch blades and switch contacts permits the control of two separate load circuits. In the embodiment of switch chosen for illustration, the switch actuating cam has two outwardly extending

wings

34 and 85 of in sulating material adapted to engage the switch blades 76 and 76' respectively, the angular relation between these wings being such that when one wing is flexing its switch blade into open circuit position, the other wing is out of engagement with its respective switch blade. This 6 relation of switch blades, switch contacts and alternately operating

cam wings

84 and 85 enables the switch apparatus to be used in any one of the following three diiferent ways:

(i) As a single pole, single throw time SWltCh-Wlth the contacts normally closed (using #1 load circuit).

(2) As a single pole, single throw time switch-with the contacts normally open (using #2 load circuit).

(3) As a single pole, double throw time switch wherein one set of contacts opens when the other set of contacts closes (using both #1 and #2 load circuits).

it will be understood that other switching arrangements may be employed, as for example wherein the angular relationship of the two cam wings 84 and 85' is such as to cause them to simultaneously fiex both switch blades and 76' outwardly to open circuit positions. The insulating panel 79 which mounts all of the above switch parts is detachably secured to the back side of the mounting plate A by screws 88 passing through apertures in the upper corners of the insulating panel and screwing into spacing posts 113 mounted on the front side of the main mounting plate. This permits the ready substitution of a different insulating panel carrying any different type of switch assembly, such as possibly a single switch blade engaging front or back contacts, such other switch assemblies being fully disclosed in the aforesaid prior Patent 2,671,- 830. To prevent the possibility of a person accidentally touching any of the terminal posts 79, 79', etc. when making time setting adjustments of the time driven dial or of the trippers on the dial, there is provided an insulating masking panel which is adapted to be removably mounted in front of the terminal posts. This masking panel is held in place by screws 112 passing through notches or openings in the panel and screwing into the spacing posts 113 which project forwardly from the mounting plate A, all as described in the aforementioned copending application. The mounting of the entire switch assembly in the housing E is also disclosed in that application.

Referring now to the normal spring biased relation of the switch actuating arm 34, the tension spring has a hook formation 136 at one end which is adapted to hook through an aperture 137 in the rearwardly bent step lug 53 of switch actuating arm 34. The opposite end of the tension spring has a similar hook formation which hooks in a notch 139 formed in the left hand edge of the mounting plate A, this portion of the mounting plate being slightly humped at the notch to provide space for the spring hook between the mounting plate and the switch supporting insulating panel.

This tension spring 135 tends normally to hold the switch actuating arm 34 swung counterclockwise to the limit of its movement in this direction, with the lug 52 abutting against the stationary mounting spindle 29. So long as the switch actuating arm 34 is in this normal spring biased position, the switch actuating cam 4-5 occupies the position shown in Figure 9, with the upper pair of

switch contacts

77, 78 closed, and with the lower pair of switch contacts 77, 78' open.

Referring now to the manually settable trippers 35a, 3511, etc., each of these is provided with a tripping cam 136 which is adapted to effect engagement against the cam shoulder or cam point 49 constituting the lower extremity of cam plate 48 secured to the switch actuating arm 34. The clockwise rotation of the time driven dial 42 brings this tripping cam 136 of each tripper 35a, etc. into engagement against the tripping shoulder 49 in a direction such will slowly swing the switch actuating arm in a clockwise direction from the normal spring biased position shown in Figure 3 to the actuated position shown in Figure 4. This oscillates the switch actuating cam 45 into its other position for operating the switch contacts into their other positions, such occurring with a snap ac nation by virtue of the over center snap action plate portion.

r '7 caused by spring 37. When the tripping cam 136 rides past the tripping shoulder 49 the tension spring 135 immediately snaps the switch actuating arm 34 back into its normal spring biased position shown in Figure 3.

Referring now to the construction of each tripper 35a, etc., and more particularly to the adjustable mounting of the tripping cam 136 thereon for enabling the duration of the switching operation to be adjusted, each tripper 35a, etc. comprises a U-shaped mounting clip 141 in the form of a stamping having a front plate portion 142 and side wings 143 bent rearwardly from the sides of the As shown in Figure 11 these wings continue as radially extending leg portions 144 which lie in back of the dial, such leg portions being provided with arcuate humps 1 55 adapted to fit into the concave back side of the circular bead 42 punched forwardly in the time dial 42 near its periphery. As shown in Figure 10, these wings 1 .3 and legs 144 converge on radial lines toward the center of the time dial. The front plate portion 142 lies in front of the dial, and this plate portion is provided with a threaded hole 148 through which screws a manually operated clamping screw 149 adapted to exert clamping pressure against the front side of the circular head 42. This plate portion is formed with an inwardly directed pointer 151 adapted to register with the time designations on the face of the dial. It will be understood that this clamped adjustable mounting enables the tripper 33a to be initially located at any desired point, or to be angularly shifted to any desired point, around the time dial for preselecting the time that the switching operation is to occur.

The tripping cam 135 is arranged for pivoting adjustment relatively to the mounting clip 141 around the axis of a pivot pin 153 which is driven into a bore in the hub portion 154 of the cam. As shown in Figure 12, the cam 1.36 is in the form of a flange or wing radiating outwardly from the rear end of the hub portion 154, and radiating outwardly from the front end of the hub portion 154 is a clamping flange or wing 155. A threaded bore 152 extends through this clamping flange 155. The outer surface of the trippingcam 136 comprises a relatively flat cam surface 136, terminating in a rounded trailing end portion 136" which is curved on a radius struck from the center of the pivot pin 153.

The projecting front end of the pivot pin 153 extends through a pivot hole 156 in the front plate portion 142 of the mounting clip 141, with the clamping flange 155 bearing against the back side of this plate portion.

Mounted on the front end of the pivot pin 153 is a pointer arm or plate 157 having a pointed end 158 adapted to register with a curved scale of time markings 159 on the plate portion 142 ranging from to approximately 60 minutes and graduated in or minute graduations. Passing freely through an upper hole 161 in the pivoted pointer arm 157 is a headed clamping screw 162. The threaded shank of this clamping screw passes through an arcuate slot 164 punched through the plate portion 142, and threads into the tapped hole 152 in the clamping flange 155 of the cam element. The arcuate slot 164 is concentric with the pivot pin 153. Thus, it will be seen that by loosening the clamping screw 162 with a screw driver, the pointer arm 157 and earn 136 can be revolved as a unit around the axis of the pivot pin .153. When the switching operation is to be relatively short duration, the pointer arm 157 is rotated down to the desired time indication on the low end of the scale 159, and conversely for a switching operation of relatively long duration.

In Figure 13 I have illustrated the action which occurs between the cam point 4-9 and one of the

trippers

35a, 35b, etc. when the cam 136 of that tripper is set for substantially the maximum length of switching operation, i. e. approximately 60 minutes in the illustrated embodiment. The leading edge of the cam 136 engages the cam point 49 and deflects a clockwise direction, thereby oscillating the front switch actuating arm 34 against the tension of its biasing spring into the switch actuated position illustrated in Fig. 13. With'the tripper adjusted for the 60 minute switching interval illustrated in Fig. 13, the entire length of the dwell or land 136' of the cam 136 remains in contact with the cam point 49 for holding the switch actuating arm 34 in its deflected position while the time driven dial 42 is traveling through the angular travel corresponding to 60 minutes. When the trailing end of the cam 136 rides past the cam point 49 the switch actuating arm 34 snaps back to its original or normal position under the acton of the biasing spring 135.

Figure 14 illustrates the action which occurs when the cam 136 of the tripper has been given an angular adjusticnt corresponding to a very short interval of switching operation. In this adjustment, most of the fore part of the cam dwell or land 136' occupies a position outwardly beyond the range of the cam point 49. It is only the trailing end portion of the cam dwell 136' which is still effective to engage the cam point 49 for deflecting the switch actuating arm 34 into the actuated position shown in Figure 14. Hence, only the trailing end portion of the cam dwell 136 is elfectiveto hold the switch actuating arm in such actuated position, and this can be quite short duration by proper setting of the cam 136.

It will be seen that any of the above settings can be given to the cams 136 of any or more of the tripping

units

35a, 35b, etc. while these units are removed from the time driven dial 42. Following the establishment of the desired cam settings in these tripping units, they can then be mounted on the dial and clamped at any preselected points around the dial at the desired switching time.

The structure of my invention can be quickly and easily converted into a conventional interval time switch of the type disclosed in the aforesaid Patent 2,671,830 by removing the tension spring 135 and then mounting on the time dial 42 the same ofi tripping unit 36 (Figure 15) and the same on tripping unit 35 (Figure 16) which are disclosed in that patent. These 05 and on tripping units engage the outer cam point 49 and the inner cam point 50 selectively for throwing the switch actuating arm 34 first in one direction and then in the other direction, all as described in the aforesaid patent.

While I have illustrated and described what I regard to be the preferred embodiment of my invention, nevertheless it will be understood that such is merely exemplary and that numerous modifications and rearrangements may be made therein without departing from the essence of the invention.

I claim:

1. In a time switch, the combination of switch contact means, spring biased switch actuating means normally holding said switch contact means in a first position, a continuously rotating time driven dial, and a switch actuating tripper carried by said dial and arranged to actuate said switch actuating means in opposition to its spring bias for moving said switch contact means to a second position, said spring biased switch actuating means automatically returning said switch contact means to said first position after completion of the switch actuating operation by said switch actuating tripper, said switch actuating tripper comprising an adjustable tripping cam arranged to impart movement to said switch actuating means and operable by movement to different positions of adjustment on said tripper to vary the length of time that said switch contact means will remain in said second position.

2. In a time switch, the combination of switch contact means, a pivoted member operatively connected with said switch contact means for moving the latter between open and closed positions, spring biased snap actuating mechanism for producing a snap make as well as a snap break of said contact means in response to movement of said pivoted member spring means normally biasing said pivoted member to a position holding said switch contact means in said first position after completion of the switch actuating operation by said tripper, said switch actuating tripper comprising a tripping cam adjustably mounted :thereon for imparting switch actuating movement to said pivoted member, said tripping cam being adjustably movable to-difierent positions on said tripper for v rying the length oftime that said switch contact means Will remain in said second position.

3. In a time switch of the class described, the combination of switch contact means, a pivoted member adapted to actuate said switch contact means between open and closed positions, spring energized snap actuating mechanism for transmitting a snap actuating motion from said pivoted member to said switch contact means for producing a snap make of said switch contact means in response to one direction of movement or" said pivoted member and for producing a snap break of said switch contact means in response to the opposite direction of movement of said pivoted member, biasing spring means normally biasing said pivoted member in one direction for normally holding said switch contact means in a first position manually actuatable means for manually moving said switch contact means from one position to another, a continuously rotating time driven dial, a switch actuating tripper adapted to rotate with said dial and arranged to actuate said pivoted member in opposition to said biasing spring means for operating said snap actuating mechanism to move said switch contact means to a second position, said biasing spring means automatically returning said pivoted member to its normal biased position and said switch contact means to said first position immediately upon completion of the switch actuating operation by said switch actuating tripper, and clamping means for mounting said tripper in dilferent preselected positions around said dial for obtaining switch operation at a predetermined time, said switch actuating tripper comprising a tripping cam adjustably mounted on said tripper for imparting switch actuating movement to said pivoted member, said tripping cam being adjustably movable to different positions on said tripper for varying the length of time that said switch contact means will remain in said second position at the switch actuating time which has been predetermined by the location of said tripper at a preselected position on said dial.

4. In a time switch, the combination of a continuously rotating time indicating dial, a relatively stationary marker cooperating with the time indications on said dial, a dial driving gear connected to said dial, a motor driven gear with which said dial driving gear normally meshes, an electric motor connected to continuously rotate said motor driven gear, said dial driving gear normally remaining in mesh with said motor driven gear for continuously rotating said dial throughout the entire time that said electric motor is operating, a switch actuated tripper mounted on said dial and rotating continuously therewith, a pivoted member arranged to be actuated in one direction by said tripper, biasing spring means normally tending to oscillate said pivoted member in the opposite direction into a normal position, switch contacts, contact actuating means responsive to said pivoted member for opening and closing said switch contacts, said biasing spring means automatically returning said pivoted member into said normal position immediately upon completion of the switch actuating operation by said switch actuating tripper,

and means enabling said time indicating dial and said dial driving gear to be shifted axially to a setting position wherein said dial driving gear is unmeshed from said motor driven gear and said tripper is clear of said pivoted member, in which position said dial can be rotatably adjusted relatively to said marker for giving the proper time setting to said dial.

5. In a time switch, the combination of switch contact means, spring biased switch actuating means normally holding said switch contact means in a normal position, a continuously rotating time. driven dial, a switch actuating tripper carried by said dial and arranged to actuate said switch actuating means in opposition to its spring bias for moving said switch contact means to another position, said spring biased switch actuating means automatically returning said switch contact means into said normal position immediately upon completion of a switch actuating operation by said switch actuating tripper, said switch actuating tripper comprising a mounting clip, clamping means for adjustably mounting said clip at different positions around said dial, and a tripping cam carried by said mounting clip and adjustable relatively to said clip for varying the time interval of the switch actuation.

6. In a time switch, the combination of switch contact means, spring biased switch actuating means normally holding said switch contact means in one position, a continuously rotating time driven dial, and switch actuating tripping means carried by said time driven dial comprising a mounting clip shiftable to different positions around the periphery of said dial to preset the time when the switching operation is to occur, and an adjustable tripper carried by said mounting clip and adapted to engage and actuate said switch actuating means, said tripper being adjustable in infinite adjustments from zero time to a predetermined maximum time relatively to said dial to adjust the duration of the switching operation.

7. In a time switch, the combination of switch contact means, a pivoted member operatively connected with said switch contact means for moving the latter between open and closed positions, spring means normally biasing said pivoted member in one direction for normally holding said switch contact means in a normal position, a continuously rotating time driven dial, and switch actuating tripping means carried by said time driven dial comprising a mounting clip, means for mounting said clip at difierent preset positions around the periphery of said dial to preset the time when the switching operation is to occur, a tripper carried by said mounting clip and adapted to engage and actuate said pivoted member against the bias of said spring means, and means for adjusting the position of said tripper in infinite adjustments from Zero time to a predetermined maximum time to adjust the duration of the switching operation, said biasing spring means automatically returning said pivoted member and said switch contact means into said normal position immediately upon completion of a switch actuating operation by said switch actuating tripping means.

8 In a time switch, the combination of switch contact means, a pivoted member operatively connected with said switch contactmeans for moving the latter between open and closed positions, spring means normally biasing said pivoted member in one direction for normally holding said switch contact means in one position, a continuously rotating time driven dial, and switch actuating tripping means carried by said time driven dial comprising a mounting clip, means for mounting said clip at different preset positions around the periphery of said dial to preset the time when the switching operation is to occur, a tripping cam pivotally mounted on said mounting clip and adapted to present a cam face to engage and actuate said pivoted member, and means for securing said tripping cam in difierent pivoted positions on said mounting clip for varying the effective length of cam face operative to 1 l actuate said pivoted member, whereby to adjust the duration of the switching operation.

9. In a time switch, the combination of switch contact means, a pivoted member operatively connected with said switch contact means for moving the latter between open and closed positions, spring means normally biasing said pivoted member in one direction, a continuously rotating time driven dial, and switch actuating tripping means carried by said time driven dial comprising a mounting clip, means for mounting said clip at difierent preset positions around the periphery of said dial to preset the time when the switching operation is to occur, a pivot carried by said mounting clip, a tripping cam on said mounting clip and swingable about the axis of said pivot, said cam presenting a cam face to engage said pivoted member and actuate it against said spring bias, a pointer swingable about the axis of said pivot, an arcuate slot in said mount- 12 ing clip concentric of said pivot, and a clamping screw passing through said arcuate slot and serving to clamp said cam and pointer in difierent angular positions about the axis of said pivot, whereby the effective length of cam face operative to actuate said pivoted member can be varied to adjust the duration of the switching-operation.

References Cited in the file of this patent UNITED STATES PATENTS 1,891,946 Porter Dec. 27, 1932 1,970,432 Porter Aug. 14, 1934 2,573,130 Moore et a1 Oct. 30, 1951 2,644,047 Leonard June 30, 1953 2,671,830 Gallagher et al Mar. 9, 1954 2,680,166 Dietrich June 1, 1954 2,742,538 Grandstatf Apr. 17, 1956 2,742,540 Whitlock Apr. 17, 1956