US3225151A

US3225151A - Time delay relay structure

Info

Publication number: US3225151A
Application number: US331143A
Authority: US
Inventors: Eugene F Lagasse
Original assignee: Giannini Controls Corp
Current assignee: Giannini Controls Corp
Priority date: 1963-12-17
Filing date: 1963-12-17
Publication date: 1965-12-21
Anticipated expiration: 1982-12-21

Description

Dec. 21, 1965 E. F. LAGASSE 3,225,151

TIME DELAY RELAY STRUCTURE Filed Dec. 17, 1963 2 Sheets-Sheet 1 :M II! LA Q a "165 16 069145 l/za ss's,

/2 -INVENTOR.

Dec. 21, 1965 E. F. LAGASSE 3,225,151

TIME DELAY RELAY STRUCTURE Filed Dec. 17, 1963 2 Sheets-Sheet 2 oEME LAHSSZ;

INVENTOR.

United States Patent 3,225,151 TIME DELAY RELAY STRUCTURE Eugene F. Lagasse, Chester, Conn, assignor to Giannini Controls Corporation, Duarte, Califi, a corporation of New York Filed Dec. 17, 1963, Ser. No. 331,143 6 Claims. (Cl. 200-35) This invention has to do generally with time delay relays. Such relays comprise typically an electric timing motor and mechanism for operating one or more switches under control of the motor after a selectively variable time interval following an initial actuating signal.

The present invention relates especially to such time delay relays of the known type wherein a shaft carries a cam adapted to operate the switch at a definite operating angle, and the time delay is varied by adjusting the initial angular position of the cam. To initiate the time delay period, a mechanical clutch of positive type is engaged in response to an input signal, typically by operation of a solenoid, connecting the shaft to the timing motor. The motor then drives the shaft and cam at uniform predetermined speed through the set angle, operating the switch when the cam reaches its operating angle. Switch operation may comprise either the opening or the closing of switch contacts or both, by selection of appropriate switch structures, depending upon the specific apparatus with which the time delay relay is to be used.

It is highly desirable that a time delay relay be readily adaptable for different purposes. One object of the present invention is to improve the ease of adaptability of such devices, by facilitating interchange of the switch or switches that are operated by the time delay mechanism; and by facilitating replacement of the timing motor by a unit having different speed or other characteristic.

A further object of the invention is to facilitate assembly and wiring of a time delay relay of the described type. That is accomplished particularly by utilizing individual switch units having built-in electrical terminals. In accordance with the invention the switch units are mounted in such a way that the terminals are accessible on the exterior of the main housing of the instrument. That is preferably done without sacrificing fully effective sealing of the instrument housing. That arangement also greatly facilitates switch interchange and the accompanying change of circuit connections.

A further aspect of the invention relates especially to the known type of positive clutch wherein input and output gears are journaled on parallel spaced axes and a clutch gear is journaled on a lever swingable about the axis of one of those gears into and out of engagement with the other. The clutch gear is continuously coupled to the gear about which it swings, either by directly meshing therewith or via a gear train.

Whereas clutch mechanisms of that known type are in most respects satisfactory for the present purpose, they have the disadvantage that engagement of the clutch may be delayed by direct opposition of gear teeth as the two gears come together. Full mesh then typically occurs only after one of the gears turns through substantially half the pitch angle. In a time delay relay in which the drive rate of the gears is sometimes extremely slow, such delay may be unacceptable. Moreover, when the gear engagement is produced by energizing a solenoid, such interference of the gear teeth tends to block the normal stroke of the solenoid armature and may lead to chattering of the armature until proper mesh is attained.

Those disadvantages are overcome, in accordance with the present invention by arranging the gear train so that the angular movement of the clutch gear as it is moved toward engaged position causes it to rotate in the normal drive direction, and by providing an overrunning clutch ice in the drive train, preferably directly at the driving gear that is selectively engaged by the clutch gear. That overrunning clutch positively couples the driving gear and its shaft with respect to the normal or forward drive direction, but permits relative rotation in the opposite direction. With that arrangement, the described rotation of the clutch gear as it comes into mesh is enabled to turn the driving gear forwardly on its shaft, insuring prompt and complete gear engagement.

A further aspect of the present invention provides convenient and economical selection of the manner of clutch actuation. The clutch can be engaged in response to solenoid energization, providing direct operation, as required for a large number of applications of time delay relays. Alternatively, the present mechanism is capable of providing inverse operation, wherein the clutch is released in response to solenoid energization and is engaged only when the solenoid circuit is open. The present mechanism permits selection of either direct or inverse clutch operation by a simple modification in assembly of the parts, and without requiring any special or additional parts.

The invention further facilitates economical and convenient manufacture, assembly and servicing of the time delay mechanism, especially by providing disassembly of the housing into two units each of which carries significant portions of the operating mechanism.

A full understanding of the invention, and of its further objects and advantages, will be had from the following description of an illustrative mechanism embodying the invention. The particulars of that description, and of the accompanying drawings which form a part of it, are intended only as illustration, and not as a limitation upon the scope of the invention, which is defined in the appended claims.

In the drawings:

FIG. 1 is a perspective representing an illustrative embodiment of the invention;

FIG. 2 is a front view corresponding to FIG. 1 partially cut away;

FIG. 3 is a section on the line 3-3 of FIG. 4, showing the parts in clutch engaging position during solenoid energization;

FIG. 4 is an axial section at enlarged scale on the line 4-4 of FIG. 3;

FIG. 5 is a partially exploded perspective illustrating certain parts of the switch actuating mechanism;

FIG. 6 is a detail section illustrating over-running clutch structure at the input drive pinion;

FIG. 7 is a detail section on the line 77 of FIG. 3; and

FIGS. 8 and 9 are schematic diagrams illustrating operating circuits for typical modes of operation.

The main housing of the present illustrative instrument comprises the unitary molded housing member 20, typically formed of a suitable plastic material, and the front plate 22. Although the instrument may be used in any desired orientation, the orientation shown in FIGS. 2 and 3 will be assumed for convenience of description. Housing member 20 then comprises the rear wall 24, the top wall 25, the bottom wall 26 and the right and

left side walls

27 and 28. The edges of front plate are bent rearwardly to form defining flanges and the side flanges are slotted to form resilient clips 23 adapted to snap over abutments 21 on housing member 20 and retain the front plate in assembled position. To disassemble front plate 22 with the parts that are mounted on it, to be described, from housing 20 it is only necessary to pry clips 23 free of abutments 21. Rear housing wall 24 carries an internal centrally located boss 30 which is bored at 31 to form a rear bearing for the main shaft 32 of the timer mechanism. The axis 33 of that shaft will be referred to as the main axis of the instrument. The forward end of shaft 'ber.

32 projects through the bushing 34, which forms a forward journal for the shaft. Bushing 34 is fixedly mounted in a central aperture in cover plate 22, in which it is typically inserted from the rear and positioned by the forwardly facing axial shoulder 35. The combined pointer and stop member 38 is fixedly mounted, as by a pressure fit and a defining pin, on the forward end of shaft 32, retaining the shaft in bushing 34. Both the forward and rear bearings of shaft 32 are preferably generously relieved, as shown clearly in FIG. 4, to facilitate the described disassembly of front plate 22.

The circular face plate 40 is fixedly mounted against the forward face of cover plate 22 in a definite position defined by the pins 42, which are fixedly mounted in the face plate and project rearwardly through accurately positioned apertures in the cover plate. Face plate 40 is secured by the retaining nut 36, threaded on the forward portion of bushing 34. Nut 36 thus serves also to retain bushing 34 in cover plate 22. The forward surface of face plate 40 carries a scale 44 with respect to which the angular position of pointer 38 can be read. The significance of that position under various conditions of operation will be explained after the mechanism has been more fully described.

The bezel 46 is fixedly mounted against the forward face of cover plate 22, radially outward of face plate 40. Bezel 46 has an inner radial flange 47 which is fittingly received in the peripheral groove 49 of face plate 40, anchoring it in axial position. The rotational position of bezel 46 may be defined conveniently by notching the inner periphery of flange 47 to engage pins 42. The main body of bezel 46 is radially spaced from the periphery of face plate 40, forming a circumferential channel 48 in which the ring 50 is rotatably mounted. Ring 50 comprises a cylindrical sleeve with fluted exterior surface, as shown best in FIGS. 1 and 2, to facilitate its manual rotational adjustment. Ring 50 carries fixedly on its inner wall an abutment 57 in position to engage the end of pointer 38, thereby limiting the clockwise rotation of the pointer at an angular position that is variable by rotation of the ring. The terms clockwise and counterclockwise as employed in the present description refer to the'instrument as viewed from the front, as in FIGS. 2 and 3, for example.

The rear edge of ring 50 is inwardly flanged at 52 to interlock with the flange 53 of the face plate. In the present device, the

flanges

52 and 53 are axially spaced to form an annular chamber adapted to receive the spring 54. That spring comprises a ribbon of resilient metal bent as shown best in FIG. 2 and prestressed to exert frictional drag on the circumferential walls of its cham- That frictional drag strongly resists rotation of ring 50 relative to fixed face plate 40, but permits such rotation when the fluted periphery of the ring is firmly gripped and turned. The forward edge of ring 50 is grooved at 56 to receive and retain the transparent protective crystal 58, typically formed of a suitable transparent plastic material. Crystal 58 is snapped into place in groove 56 after assembly of the other parts. The crystal carries a radially extending tab 59 which is received in a fitting notch in the forward edge of ring 50. The crystal can be removed by prying under that tab. Removal of nut 36 then permits disassembly from front plate 22 of all the parts mounted thereon. However, as already indicated, those parts nee-d not be disturbed to obtain access to the interior of housing 20, since they and front plate 22 are removable from the housing as a unit.

Within the housing, shaft 32 carries the spur gear 70, which is fixedly mounted on the shaft by means of the hub 71. Also mounted on shaft 32 is the timing cam 7 8, adapted to operate timing switches to be described. In the present embodiment, cam 78 is riveted to the forward face of gear 70. The assembly comprising shaft 32, pointer 38, gear 70 and cam 78 rotates as a unit and will be referred to for convenience as output assembly 80. A

light helical coil spring, indicated somewhat schematically at 74, has its inner end fixed to the periphery of bushing 34 and its outer end secured to gear 70, as by the pin 75. The spring exerts a light torque in a clockwise direction upon output assembly 80. That assembly is thereby rotated, in absence of other action to be'described, into the position defined by engagement of pointer 38 with adjustable abutment 57. That engagement normally defines the initial position of the output assembly at the start of a timing period. A fixed clockwise limit stop 82 for output assembly'80 is preferably also provided inside housing 20, to prevent that assembly from following clockwise adjustment of abutment 57 beyond the intended range of movement. Stop 82 is mounted on the rear face of front plate" 20 in position to engage cam 78. The angular position of stop 82 about main axis 33 is shown in dotted lines in FIG. 2. The position of cam 78 when engaging the stop is also indicated schematically at 78a. Typical construction of the stop is shown in FIG. 4, although the stop would not actually appear in that figure.

Output assembly 80 is drivable counterclockwise by the timing motor assembly 90, comprising the motor 91 and the conventional reduction gear train indicated at 92. That drive acts through thepositive clutch mechanism now to be described. The broad essentials of that clutch structure are well known. The clutch lever is pivotally mounted coaxially of main shaft 32 on bearing surfaces formed on the outer surface of housing boss 30. Lever 100 comprises the hub structure 102, the main lever arm 104 and two arms 106 and 107. Lever arm 106 carries a cam structure 108 which is adapted to operate timing switches (to be described) in response to clockwise lever rotation. Lever arm 106 is also connected to one end of the coil spring 109, the other end of which is fixed to the housing. Spring 109 exerts upon the lever a substantially constant yielding torque in a counterclockwise direction. Lever rotation in that direction is limited by the positive stop which comprises the lug 103, extending rearwardly from lever arm 107 and the fixed abutment mounted on rear wall 24 of the housing (FIG. 3). Clockwise rotation of lever 100 is limited at the lever position shown in FIG. 3 by the switch actuating structure to be described.

Lever arm 107 is operatively coupled via the short and stiff coiled spring 111 to the armature 112 of the solenoid 110. Energization'of the solenoid retracts armature 112 upward and exerts upon lever 100 a strong torque in a clockwise direction, easily overcoming the relatively light force of spring 109 and driving the lever through a small angle to the clockwise end of its travel. Upon release of the solenoid, spring 109 drives the lever back to the counterclockwise limit of its travel.

Lever arm 104 carries a shaft 115, freely journaled on an axis parallel to main axis 33 and radially offset therefrom. Shaft 115 carries the gear 116 fixedly mounted on its forward end and the clutch-gear 117 fixedly mounted on its rearward end. The radial offset of shaft 115 from main axis 33 is such that gear 116 continuously engages gear 70, already described. Pivotal movement of lever 100 does not disturb that gear engagement, since such movement is coaxial with gear 70.

The motor output shaft 93, mounted on reduction gear 92 and driven by timing motor 91 extends forwardly through an aperture indicated at 118 in rear housing wall 24 and carries the pinion 120. Pinion 120 is preferably positioned at substantially the same radial distance from main axis 33 as shaft 115, and its angular position about axis 33 is such that it is engaged by clutch gear 117 in one of the extreme positions of clutch lever 100. As illustrated, that engagement occurs in the extreme clockwise position of lever 100, thatis, when solenoid 110 is energized (FIG. 3). Under that condition, there is a positive driving connection from the timing motor through pinion 120 and gear 117 to shaft 115, and then via gear 116 to gear 70 and output assembly 80. The latter assembly is thereby driven in a counterclockwise direction. Upon release of solenoid 110, gear 117 swings counterclockwise with clutch lever 100 out of mesh with pinion 120. The output assembly is then free to turn clockwise under the influence of helical spring 74 until stopped by contact of pointer 38 with abutment 57. The pivotal movement of lever 100 thus functions as a clutch of positive type, connecting the timing drive of the output assembly in response to solenoid energization and releasing that drive when the solenoid is deenergized.

In some applications of a time delay relay it is required that the solenoid control of the clutch action be inverted relative to that just described. That is, it is desired that the timing motor be coupled to output assembly 80 when solenoid 110 is deenergized, and that the driving connection be released when the solenoid is energized. Such inverse operation might be obtained, for example, by reversing the direction in which solenoid energization swings the clutch lever; or by redesigning the clutch lever so that arm 104 and gear 117 are on the opposite side of pinion 120 from that shown in FIG. 2.

One aspect of the present invention provides mechanism that can be assembled in two distinct configurations without structural change, one configuration providing direct solenoid control of the clutch action, and the other configuration providing inverse solenoid control of the clutch action. That has the great advantage that both modes of operation are made available without manufacture of any special parts. Moreover, the conversion of a unit from one mode of operation to the other is remarkably straightforward and convenient, so that the change can readily be made by the ultimate user of the mechanism. Hence it is not necessary to assemble and carry in stock both types of device.

That useful functional flexibility is made possible by providing mechanism by which the motor and gear train unit can be mounted on the rear wall of housing 20 selectively in either one of two definite positions. Those positions differ by motor rotation through 180 about a rotation axis that is parallel to the output shaft 93 and pinion 120 from the gear train and is offset from that shaft. It is then possible to select the magnitude of that offset and the position of the rotation axis relative to main axis 33 so that in one position of the motor unit the pinion is engaged by the clutch gear only at one extreme of the gear movement, and in the other position of the motor unit the pinion is engaged by the clutch gear only at the other extreme of the gear movement.

In the present illustrative mechanism, motor and gear unit MB is cylindrical and carries two mounting brackets at diametrically opposite positions. Those mounting brackets comprise projecting ears 94 which are drilled to receive mounting screws 95 parallel to the cylindrical axis 124 of the unit. Corresponding threaded holes are provided in the rear wall of housing 20. The motor can then be mounted in either one of two positions, depending upon which ear is aligned with which mounting hole. Those two positions differ from each other by rotation of the motor through 180 about its cylindrical axis 124. The mounting holes are so placed that axis 124 is positioned as indicated in FIG. 3, that is, adjacent clutch gear shaft 115. More exactly, axis 124 lies on the line 125 which is radial with respect to main axis 33 and which substantially bisects the two limiting positions of clutch gear shaft 115. The linear offset of pinion 120 from that line is indicated in FIG. 3 by the arrow 126. That distance is approximately equal to the sum of the pitch radii of pinion 120 and clutch gear 117 plus half the linear movement of the clutch gear shaft between its two limiting positions. That approximate relation is subject to some variation due to the curvature of the clutch gear move ment and to the fact that the radial distance of pinion 120 from main axis 33 may differ considerably from that of 6 clutch gear shaft without interfering with "satisfactory clutch operation.

The motor position shown in FIG. 3, for example, corresponds to what has been described above as direct clutch operation. In the alternative motor position, for inverse clutch operation, motor pinion assumes the position indicated in dot-dash lines at 120a. An aperture 119 is provided in the rear wall of the housing at that position. Whichever one of the

apertures

118 and 119 is not occupied by pinion 120 is effectively sealed by presence of the motor unit mounted on the exterior face of the housing.

A further aspect of the present invention provides improved speed and reliability of clutch engagement. That improvement is especially noteworthy under conditions of very slow gear rotation due to extreme speed reduction in gear train 92, as in time delay relays designed to provide relatively long delay periods. In accordance with the present aspect of the invention, an overrunning clutch is provided in the driving connection to pinion 120, preferably directly at the pinion itself. One illustrative type of such over-running clutch is shown in FIG. 6, comprising three rollers which are received in respective wells 131 formed in the cylindrical inner Wall of the pinion. The depth of each well decreases progressively in the direction of drive of the pinion shaft 93 and the roller is lightly urged by a spring 134 in that direction so that it tends to jam between the well bottom and the opposing cylindrical wall of the drive shaft. Forward rotation of shaft 93 is communicated substantially immediately and positively to pinion 120 via the wedged rollers, whereas the pinion is essentially free to rotate in a forward direction relative to the shaft. During such relative rotation the'rollers lag behind, due to friction on the shaft, slightly compressing the springs 134 and becoming free in their wells. Springs 134 can be made extremely light, so that the frictional drag that resists such overrunning action is essentially negligible.

As clutch gear 117 approaches the pinion during clutchengaging clockwise rotation of clutch lever 100, the gear is rotated in a clockwise direction by the rolling movement of gear 116 on stationary gear 70. With pinion 121} provided with an overrunning clutch, as just described, that rotation of gear 117 can be freely communicated to pinion 120 as soon as their teeth touch. Hence, even if teeth of the gear and pinion are in abutting position, which would ordinarily prevent full mesh, the rolling movement of the gear and pinion overcomes that blocking action and insures full mesh essentially immediately and independently of the driving rotation of pinion shaft 93, which may be very slow. It may be noted that the described improvement of clutching action is most effective when the direction of normal pinion drive is the same as the direction in which the pinion is drivable by the rolling action of the clutch gear. In the present embodiment that relation is satisfied with clutch gear 117 and rolling gear 116 mounted on a common shaft. The same would be true if gear 116 acted also as clutch gear, in which case gear 117 might be omitted. To accommodate opposite drive direction, gears 117 and 116 may be coupled by a gear train designed to produce any desired relationship of speed and direction.

A further aspect of the present invention relates to the switch mounting arrangement and switch actuating mechanism. The invention utilizes a plurality of individual switch units, which are typically of conventional construction such as is available commercially in a variety of detailed forms and switching functions. Each of the present switch units comprises a rectangular case 141 having two through bores 142 near diagonally opposite corners of its side faces. Electrical connection terminals project from the case. Two terminals 144 are at the rear end of the case, as positioned in the housing, and the third terminal 145 is at the center of the case bottom. A switch operating button 146 projects from the top wall of the case near its forward end. Each switch unit typically contains a singe pole, double throw switch, with the switch armature connected to external terminal 145 and the normally open and normally closed contacts connected to the respective external terminals 144. Depression of button 146 then shifts connection of terminal 145 from one terminal 144 to the other.

The present housing member 26 is formed with a plurality of individual switch chambers 150 arranged in line along its lower rear edge. Those chambers are separated from the main interior chamber of the housing by the horizontal wall 152 and the vertical wall 156. Adjacent chambers 150 are separated from each other by the partitions 156. Each chamber 150 is entirely open at its rear end for insertion of the switch unit; and bottom wall 26 of the main housing member is typically cut away at 157 (FIG. 4) to accommodate switch terminals 145. The section of horizontal wall 152 that is directly opposite each switch-operating button 146 is formed in such a way that it can easily be broken out to produce a window through which the button is accessible from inside the main housing chamber. That break-away wall section is shown still in place at 160 for the left hand switch chamber, which contains no switch (FIG. 3). The window produced by breaking out such a section is shown at 162 in the adjacent chamber and also in FIG. 4.

The switches are mounted in chambers 150 by means of rods 158 which are received in horizontal bores in the

side walls

27 and 28 of the main housing and in partitions 156 between the switch chambers. Each of those rods may extend the entire width of the housing, through bores 142 of all switches to be mounted. However, it is convenient to form the rods in shorter sections, each section typically serving to mount two adjacent switch units. End portions of the mounting rods may be knurled to grip the plastic of the housing to retain them in position after the desired switches have been mounted in a particular instrument.

Any required number of switch chambers may be provided, with appropriate mechanism for operating the switches that are mounted in them. In the present illustrative instrument, four switch chambers are provided, arranged in two pairs, one pair adjacent each side wall of the main housing. The present illustrative operating mechanism is adapted for operating the right hand pair of switches simultaneously under control of cam structure 108 mounted on arm 106 of clutch lever 100; and for operating the left hand pair of switches simultaneously under control of cam structure 78, which forms a part of output assembly 80.

The two. switches of each pair are operated by a common lever pivotally mounted on a lever axis indicated at 164. Pivot shafts 166 for the respective levers are fixedly mounted in the main chamber of the housing, as by inserting them in closely fitting bores in the

housing side walls

27 and 28 and in the oblique bracing webs 167. Each switch lever comprises a plate 168 mounted on rod 166 for free pivotal movement, as by slotting the plate transversely of the rod and bending intervening portions of the plate in opposite directions to receive the rod between them. Each lever plate 168 is generally parallel to the horizontal wall 152 and spacedly opposes the knockout sections for the two switch chambers with which it is associated. Two switch operating abutments 169 are mounted on the under face of each plate in position to engage a switch button 146 projecting through the window 162 and to operate the switch in response to downward pivotal movement of the lever. Those abutments are preferably placed high enough to clear a remaining knock-out section 160 (FIG. 3) even in the lever position that operates a switch in the neighboring switch chamber. Abutments 169 may be adjustably mounted on lever plates 168 if desired, but in practice that is not ordinarily necessary. The right hand switch operating lever is deflected downward by cam formation 108 in response to solenoid energization, as shown in FIG. 3. The left hand switch operating lever is deflected downward by cam 78 after the latter is driven by the timing motor to its switch operating position, indicated schematically at 7 8b in FIG. 3.

The zero point of scale 44 on the instrument face is preferably at the angular position of pointer 38 as switches 46b are operated by cam 78. The scale is then provided with numerals increasing clockwise in such a way that each point of the scale represents the time required for the pointer to be driven by the timing motor from that point to the scale zero.

Illustrative electrical connections to solenoid 110 and timing motor 91 are shown schematically in FIGS. 8 and 9. The two right hand switches, operated in response to energization of solenoid 110, are represented at a. The two left switches, operated at the end of the timing interval by cam 78, are represented at 14012. A source of alternating current of predetermined frequency is indicated at 170. The circuit of FIG. 8 illustrates operation of the time delay relay when assembled for direct clutch operation by the solenoid. Timing motor 91 is connected in series with source and with the normally open switch contacts of switch A of pair 148a. The motor then operates whenever solenoid 110 is energized. The solenoid winding is connected in series with source 170 and with the control switch 174. A. holding circuit for the solenoid is connected in shunt to control switch 174, including in series the normally open switch contacts of switch B of pair 140a and the normally closed switch contacts of switch B of pair 1401). Switch A of pair 1411b may be connected to any desired output device, indicated schematically at 180, which is to be operated after a set time delay.

With those connections, a timing cycle is initiated by momentary closure of control switch 174. The resulting solenoid energization operates switches 140a, starting timing motor 91, and closes the clutch to drive output assembly 100 counterclockwise from its set initial position. As soon as the holding circuit is closed, switch 174 may be released without interrupting that drive. After the set time period cam 78 operates switches 1401). Switch A performs the desired delayed action in output device 1811. Switch B opens the solenoid holding circuit, restoring switches 140a to normal position and releasing the clutch. The system is thereby returned to idle condition, ready for another timing cycle.

The circuit of FIG, 9 illustrates operation of the time delay relay when assembled for inverse clutch operation by solenoid 118. Current source 170 is connected to solenoid 110 via the normally open reset switch 175. Timing motor 91 is connected in a circuit that includes in series, source 170, the main switch 172, and the normally closed contacts of switch B of switch pair 16Gb. Switch A of pair 146!) is connected to output device 182.

Closure of switch 172 initiates a timing cycle by starting motor 71, since the drive clutch is already engaged with solenoid 111) deenergized. At the end of the set timing period, switches 1 10b are operated, performing the desired control action in output device 182 and opening the motor circuit. Since the clutch remains engaged, output assembly 180 remains in its extreme counterclockwise position, holding switches 1411b operated for an indefinite time period. Closure of reset switch 175 momentarily releases the clutch, allowing output assembly 1110 to be spring returned to its set initial position. If switch 172 has been left closed, a second timing cycle then starts immediately.

I claim:

1. Time delay mechanism comprising in combination a frame,

a shaft j-ournaled on the frame on a main axis and carrying a main gear for driving the shaft,

, means continuously rotatively coupling the clutch gear and the main gear, solenoid means for shifting the lever means selectively between its said positions,

van input' gear journaled on the frame in position to be engaged by the clutch gear in only one of said positions of the lever means, lever movement toward said one position causing rotation of the clutch gear in a forawrd direction,

driving means,

an overrunning clutch interconnecting the driving means and the input gear for positively driving the input gear in a forward direction while permitting free forward rotation of the input gear relative to the driving means, said forward rotation of the input gear driving the engaged clutch gear in its said forward direction,

and circuit means for selectively energizing the solenoid means.

2. Time delay mechanism comprising in combination a frame,

a shaft journaled on the frame on a main axis and carrying a main gear for driving the shaft,

settable means for placing the shaft in a variable initial position,

output mechanism coupled to the shaft for actuation at a definite position thereof,

lever means swingable about the main axis between first and second positions and carrying a clutch gear journaled on a clutch gear axis parallel to the main axis and offset therefrom,

means continuously rotatively coupling the clutch gear and the main gear,

solenoid means for shifting the lever means selectively between its said position,

an electric motor unit,

mounting formations on the frame and on the motor unit intergageable selectively in two different motor unit positions relative to the frame, which positions differ by motor unit rotation through 180 about a rotation axis parallel to the main axis and adjacent the clutch gear axis,

the motor unit including an output pinion on a pinion axis parallel to said rotation axis and offset there from by a predetermined distance such that in one motor unit position the pinion is engaged by the clutch gear only in said first position of the lever means and in the other motor unit position the pinion is engaged by the clutch gear only in said second position of the lever means,

and circuit means for energizing the motor and for selectively energizing the solenoid means.

3. Time delay mechanism comprising in combination a frame,

settable means for placing the shaft in a variable initial position,

means continuously rotatively coupling the clutch gear and the main gear,

solenoid means for shifting the lever means selectively between its said positions,

a generally cylindrical motor unit having a unit axis and having two like mounting formations symmetrically and oppositely offset from the unit axis,

two like mounting formations on the frame symmetrically and oppositely offset from the mean position of the clutch gear axis in said first and second positions of the lever means,

the mounting formations on the frame and on the motor unit being interengageable to mount the motor unit selectively in two positions relative to the frame, which positions differ by motor unit rotation through about the motor axis,

the motor unit including an output pinion on a pinion axis parallel to the unit axis and offset a predetermined distance therefrom, said offset distance substantially corresponding to the sum of the pitch radius of the pinion, the pitch radius of the clutch gear and half the linear movement of the clutch gear axis bebetween said first and second positions of the lever means,

whereby in one motor unit position the pinion is engaged by the clutch gear only in said first position of the lever means and in the other motor unit position the pinion is engaged by the clutch gear only in said second position of the lever means,

4. Time delay mechanism comprising in combination main housing structure forming an enclosure, said structure including a plurality of wall sections adapted to be selectively knocked out to form respective apertures through the housing wall,

lever means pivotally mounted within the enclosure and having a plurality of working faces spacedly opposing respective said sections of the wall and movable transversely thereof in response to pivotal movement of the lever means,

time delay mechanism within the enclosure actuable to cause movement of the lever means after a definite time delay,

a plurality of switch units each comprising a switch, a switch housing enclosing the switch, a movable switch actuating element protruding from one portion of the switch housing, and a plurality of terminal elements electrically connected to the switch and protruding from another portion of the switch housa means on the main housing structure for detachably mounting the switch units externally of the enclosure with the switch terminals accessible for circuit connections externally of the housing structure and with the switch actuating elements extending through respective said apertures in the housing wall for actuation by the lever means in response to said movement thereof, each said aperture being effectively scalable by the switch housing of a mounted switch unit.

5. Time delay switch mechanism, comprising in combination structure forming a housing with open front,

a centrally apertured housing cover,

means for releasably mounting the cover in accurately defined position on the housing to close the front thereof,

said housing including a rear wall having a forwardly extending annular boss coaxial with the cover aperture,

a shaft journaled intermediate its length in the cover aperture, the rear end of the shaft being received in journaling relation in the housing boss and being freely removable axially therefrom when the cover is demounted from the housing,

a radial arm fixedly mounted on the shaft forward of the cover,

a driving gear and cam means fixedly mounted on the shaft between the cover and the housing boss,

spring means acting between the cover and the shaft and exerting on the shaft a yielding torque in one direction,

a stop ring mounted on the cover coaxially of the shaft and radially surrounding the arm,

an abutment mounted on the ring and adapted to engage the arm and limit shaft rotation in said one direction,

the ring being stifiiy rotatable manually to vary the angular position of the abutment means,

scale designations carried by the cover inside the stop ring for visually indicating the arm position,

timing motor means,

clutch means within the housing for selectively coupling the motor means to the gear to drive the shaft against the force of said spring,

and switch means mounted on the housing for actuation by said cam means at a definite angular position of the shaft.

6. Time delay switch mechanism as defined in claim 5 and wherein said clutch means comprises a clutch lever pivotally mounted on the outer periphery of the housing boss coaxially of said shaft,

a clutch gear journaled on the lever on a clutch gear axis parallel to the first said shaft and ofiset therefrom,

means continuously rotatatively coupling the clutch gear and the first said gear,

solenoid means for swinging the lever between predetermined first and second positions,

and an input gear continuously coupled to the motor means and mounted in position to be engaged by the clutch gear in only one of said positions of the lever,

said motor means comprising a unitary motor and gear unit having an output shaft and mounted on the rear housing wall on the exterior of the housing, the rear housing wall being apertured and the output shaft projecting through the rear wall aperture into the housing,

and. the input gear being mounted on said output shaft of the motor and gear unit within the housing in the said position.

No references cited.

25 BERNARD A. GILHEANY, Primary Examiner.

Claims

1. TIME DELAY MECHANISM COMPRISING IN COMBINATION A FRAME, A SHAFT JOURNALED ON THE FRAME ON A MAIN AXIS AND CARRYING A MAIN GEAR FOR DRIVING THE SHAFT, SETTABLE MEANS FOR PLACING THE SHAFT IN A VARIABLE INITIAL POSITION, OUTPUT MECHANISM COUPLED TO THE SHAFT FOR ACTUATION AT A DEFINITE POSITION THEREOF, LEVER MEANS SWINGABLE ABOUT THE MAIN AXIS BETWEEN FIRST AND SECOND POSITIONS AND CARRYING A CLUTCH GEAR JOURNALED ON A CLUTCH GEAR AXIS PARALLEL TO THE MAIN AXIS AND OFFSET THEREFROM, MEANS CONTINUOUSLY ROTATIVELY COUPLING THE CLUTCH GEAR AND THE MAIN GEAR, SOLENOID MEANS FOR SHIFTING THE LEVER MEANS SELECTIVELY BETWEEN ITS SAID POSITIONS, AN INPUT GEAR JOURNALED ON THE FRAME IN POSITION TO BE ENGAGED BY THE CLUTCH GEAR IN ONLY ONE OF SAID POSITIONS OF THE LEVER MEANS, LEVER MOVEMENT TOWARD SAID ONE POSITION CAUSING ROTATION OF THE CLUTCH GEAR IN A FORWARD DIRECTION,