Memory And Control Device With Cams Which Act In Both Radial And Axial Directions

Abstract

A memory and control device for positioning a power seat to preset positions and selectively repositioning it to such preset positions and also providing manual control of the seat to place the seat in any position. The present invention utilizes the same switches for setting different preset positions and utilizes cams on both sides of said switches which may be moved axially to selectively engage the switches to energize the power seat to the selected preset position.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS AND PATENTS

This application is related to the application entitled "Memory and Control Device", Ser. No. 850,157, filed Aug. 14, 1969 by Burton L. Siegal, and to U.S. Pat. No. 3,472,978, which issued on Oct. 14, 1969, entitled "Memory and Control Device With Disc Contract Plates On A Linearly Movable Shaft That Are Adjustable With Respect To The Shaft", filed by Peter C. Granata, Jr., Burton L. Siegal and Edward J. Zeissler.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates in general to automatic positioning devices and in particular to means for automatically positioning a seat to predetermined positions.

2. Description of the Prior Art

Six-way position power seats have previously been accomplished manually by adjusting the position of three control switches to a selected position. Since automobiles are often used by more than one person and particularly by two people such as a husband and wife, it is desirable to have a memory control system for automatically repositioning a seat to the preferred setting of a different driver which can be accomplished automatically.

SUMMARY OF THE INVENTION

The present invention comprises an electromechanical memory positioning system that allows a power seat to be automatically positioned to a preset position each time the driver enters the vehicle. The present invention utilizes a single set of motor control switches in combination with a pair of cams such that when the cams are moved in a first direction, one of the pair of cams will energize the switches to move the power seat to a first position and when the cams are moved in a second direction the second cam will energize the switches to move the seat to a second position.

Position feedback is provided so that the seat will stop at the preset position. The present control system provides a simple and reliable structure which substantially reduces the number of components and switches required in prior devices.

Other objects, features and advantages of the invention will be readily apparent from the following description of preferred embodiments thereof taken in conjunction with the accompanying drawings, although various modifications may be effected without departing from the spirit and scope of the novel concept of the disclosure and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an automobile seat-positioning apparatus according to the invention;

FIG. 2 is a sectional view of the memory and control device illustrated in FIG. 1;

FIG. 3 is a sectional view taken on line III--III of FIG. 2;

FIG. 4 is a sectional view taken on line IV--IV of FIG. 2;

FIG. 5 is a schematic view illustrating the electrical control circuitry for a single control of the invention;

FIG. 6 is a schematic diagram of a modified form of the invention; and

FIG. 7 illustrates the modified form of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates in partial cutaway an automobile seat 21 which for illustrative purposes has three motors 17, 18 and 19 to control the position of the seat. The motor 17 moves the front portion of the seat up and down, the motor 18 moves the seat backward and forward, and the motor 19 moves the rear portion of the seat up and down. Thus, by adjustment of the three motors 17, 18 and 19, the seat may be moved backward and forward and tilted and raised and lowered. The memory and control device 10 of this invention is connected respectively to the motors 17, 18 and 19 by electrical leads 22, 23, 24, 26, 27 and 28, and receives position feedback from the motors by shafts 29, 31 and 32 which are respectively connected to the motors 17, 18 and 19. The seat may also be controlled by manual control 13 which has manual switches 14, 15 and 16 that are connected to the memory and control device of the invention 10 by leads 34a through 34f. A battery E has one side connected to ground and the other side connected by a lead 33 to the manual control switch assembly 13 and to the memory and control device 10 of the invention.

The control 10 has an actuating shaft 11 rotatably and slidably mounted therein and has a pointer 12 which may be positioned in the his, manual or her positions.

FIGS. 2 through 5 illustrate the control system of the invention. For example, FIG. 2 is a sectional view of the memory and control device 10. The device 10 is substantially hollow and is formed with outer walls 20 which rotatably support a shaft 41 that carries a first gear 42 which meshes with a drive gear 36 which is supported on the position feedback shaft 29 from the motor 17. The gear 42 has a hub 45 which carries a gear 43 that meshes with a gear 64 rotatably supported on a shaft 52. Shaft 31 is rotatably supported in the housing 20 and carries a gear 37 which meshes with a gear 44 mounted on shaft 41 and which is connected by hub 47 to a gear 46. Gear 46 meshes with a gear 65 rotatably mounted on shaft 52. Shaft 32 for the motor 19 is rotatably supported by the housing 20 and carries a gear 38 which meshes with a gear 48 that has a hub 49 that supports gear 51. Gear 51 engages gear 66 which is rotatably supported on the shaft 52.

The shaft 52 is supported for rotational and longitudinal motion relative to the housing by sleeves 53 and 54 mounted in opposite end walls of the housing 20. A spring 56 is mounted between a shoulder formed on the sleeve 53 and a disc 57 which is locked to shaft 52 by a snapring 58. A spring 59 is mounted between the shoulder formed on the sleeve 54 and a shifting collar 63 which is pinned to shaft 52 by a pin 62. A shifting lever 99 is rotatably supported in a collar 104 which is mounted on shaft 11 and has an engaging portion 101 which fits between sidewalls 102 and 103 of the shifting member 61 to position the shaft 52 longitudinally relative to the housing 10. Retaining rings 68 and 69 are mounted on shaft 52.

Each of the gears 64, 65 and 66 supports cams which cooperate with switch assemblies for positioning the seat 21. The gear 64, for example, has a hub 67 that rotatably supports cams 71 and 72. As best shown in FIG. 4, the hub 67 is formed with a flattened side and a first friction disc 76 is formed with a D-shaped opening and is received on the hub so that it does not rotate relative to the hub. The friction disc 76 bears against the cam 71 which has a round opening through which the hub 67 extends so that the cam 71 may be rotatably adjusted relative to the hub 67. A spring 73 is mounted between the friction disc 76 and a second friction disc 77 which is also formed with a D-shaped opening so that it does not rotate relative to the hub 67. A second cam 72 formed with a round opening is mounted on the hub 67 adjacent the disc 77, and a third friction disc 78 is mounted on the hub adjacent the other side of the cam 72. The friction disc 78 is also formed with a D-shaped opening so that it does not rotate relative to the hub 67. A snapring 79 is receivable in a groove formed in the hub adjacent the friction disc 78 to lock the cam assembly to the hub. The gear, hub and cam assembly thus formed allows the cams 71 and 72 to be rotated relative to the hub for allowing them to be preset to a desired position. However, the cams 71 and 72 when not held relative to the hub 67 will rotate with the hub 67 to remember preset positions.

A pair of cam-shaped members which are generally V-shaped 81 and 84 and formed with cam-engaging portions 82 and 83, and 86 and 87, respectively, are supported between the cams 71 and 72 and are supported as shown in FIG. 5 from an insulating frame member 110 which is connected to the housing 20.

V-shaped cam switching means 91 and 92 are supported between cams 88 and 89 and V-shaped switching means 96 and 97 are supported between the cams 93 and 94.

As seen in FIGS. 2, 4, and 5, each of the cams 71, 72, 88, 89, 93 and 94, are formed with portions which extend approximately 180.degree. around the shaft 52 which are thicker and larger in diameter than the remaining portion of the cams. For example, cam 71 as illustrated in FIG. 4 has a first portion 71a which extends substantially 180.degree. about the cam and which has a substantially larger radius than the remaining portion 71b of the cam. Also as seen in FIG. 2, the portion 71a is substantially thicker than the portion 71b, such that when the shaft 52 is moved longitudinally relative to FIG. 2 the portion 71a will engage one of the switch-actuating cams 81 or 84 if the enlarged portion 71a is adjacent either of the switch-actuating means 81 or 84. Thus, the cams and switches provide means for controlling a control circuit by moving the shaft 52 longitudinally relative to FIG. 2. For example, if the shaft 52 is moved to the left relative to FIG. 2 the cams 72, 89 and 94 may engage either of the switches 81, 84, 91, 92 or 96, 97, unless they are in the home position illustrated in solid line in FIG. 5. On the other hand, if the shaft 52 is moved longitudinally to the right relative to FIG. 2, the cams 71, 88 and 93 may engage the switches 81, 84, 91, 92, 96, 97 unless they are in the home position such as illustrated in FIG. 5. Thus, the position of the two cams on either side of the switches allows a single set of switches to be utilized to operate the memory and control system and the invention results in a substantial reduction in the number of switches required in a memory system.

FIG. 5 illustrates the electrical schematic for control of the seat in one dimension. The armature 17a of the motor 17 has one terminal 117 connected to a flexible conductor 113 which carries the switch actuator 81. The contact 113 is mounted in a supporting insulating plate 110 which is mounted in the housing 20 and the conductor 113 has a pair of contacts 114 and 115 on opposite sides thereof and the contact 115 engages a contact 117 when the switch actuator 81 is out of engagement with the high portion of cams 71 and 72. Contact 120 is connected to conductor 116 which is also mounted in the insulating plate 110. A conductor 111 is also mounted in insulating plate 110 and has a contact 112 which is engaged by contact 114 when the switch actuator 81 is in engagement with the high portion 71a of cam 71 or the corresponding high portion of the cam 72. The other terminal 118 of armature 17a is connected to a conductor 122 which is mounted in the supporting plate 110 and carries the switch actuator 84. Contacts 123 and 124 are mounted on opposite sides of conductor 122 and contact 123 engages contact 121 supported by conductor 119 when the switch actuator 84 does not engage a high portion of cams 71 or 72. Conductor 126 is mounted in insulating plate 110 and carries a contact 127 which engages contact 124 when the switch actuator 84 is in engagement with a high portion of cams 71 or 72. The battery E has one side connected to ground and the other side is connected by lead 33 to conductors 111 and 126. Contact 116 is connected to ground through a switch 136 and contact 119 is connected to ground through a switch 138. Lead 33 is also connected to manual switch 131 which is movable to engage contact 134 or 137. Manual switch 131 also carries switch-actuator portions 132 and 133 for respectively opening switches 136 or 138 when the manual switch is moved respectively to an engagement with contacts 134 or 137.

FIG. 3 illustrates a linkage for moving shaft 52 axially to the left or to the right relative to FIG. 2 so that the cams 71, 88 and 93 or cams 72, 89 and 94 can engage the energizing switch contacts. If the knob 12 is moved to the his position, for example, the shaft 11 will cause sleeve 104 to move clockwise relative to FIG. 2, thus pushing member 103 to the left relative to FIG. 2 which, in turn, moves shaft 52 to the left relative to FIG. 2. This moves cams 72, 89 and 94 toward their respective switches 81, 84, 91, 92 and 96, 97. If the switch actuators of any of these switches engage the high portions of their respective cams a circuit will be closed to energize the motor in either the clockwise or counterclockwise directions. The motors will run until all of the cams are positioned so that they are out of engagement with the energizing switches 81, 84, 91, 92 and 96, 97. This corresponds to the preset "his" position. When another person enters the vehicle, she may move the control knob 12 to the "her" position which will cause shaft 11 to rotate the member 104 counterclockwise relative to FIG. 2, thus causing the shaft 99 to move the collar 61 to the right relative to FIG. 2 such that the cams 71, 88 and 93 engage the switches 81, 84, 91, 92 and 96, 97, respectively. For example, relative to FIG. 5, when the cam 71 is moved toward the switch actuators 81 and 84 unless it is in the position shown in solid line it will close either switch 81 or 84 to energize the motor 17. It will be noted, for example, that if the high portion 71a of the cam 71 engages the switch actuator 81, power will be applied to the armature 17a through the lead 33, the conductor 111, contacts 112, 114, conductor 113 to terminal 117 through the armature 17a and to ground through terminal 118, contact 122, 123, 121, 119. The motor will then run in a direction so as to move the high portion of the cam 71a counterclockwise relative to FIG. 5 until the high portion of the cam 71a is in the solid line position relative to the switch actuators 81 and 84 which corresponds to the preset "her" position. If the high portion of the cam 71a were in the position such that it engaged the switch actuator 84, power would be applied from lead 33 through contact 126, 127 and 124, conductor 122 to terminal 118 through the armature and to ground through conductor 113, contact 115, 117 and conductor 116. It is to be noted that the direction of current through the armature 17a flows in opposite directions when the high portion of the cam 71a engages switch actuator 81 or 84. When the high portion of the cam 71a moves to the solid line position relative to FIG. 5, the cam will no longer engage the switch actuators 81 and 84 and power will be disconnected to the armature 17a and both ends of the armature will be connected to ground through conductors 116 and 119 so as to apply dynamic braking to the motor. A spring 108 is mounted on shaft 104.

To set the memory control system of this invention to a different preset position, the knob 11 is first rotated to the "his" or "her" position without pulling out the knob so that the motor will have positioned the seat to the home position indicated in solid line in FIG. 5 such that the switch actuators 81 and 84 no longer engage the high portion 71a. The shaft 11 may then be pulled out since the end 106 of shaft 99 is out of alignment with the stop 107 when in the "his" or "her" position. The stop 107 holds the shaft 52 in the "his" or "her" position in that the shaft 99 must be rotated clockwise or counterclockwise relative to FIG. 2 to allow the end 106 of shaft 99 to miss the stop 107. The seat may then be positioned manually by using the manual switches and the ends of the switch actuators 81 and 84 will hold the cam 71 such that it rotates relative to shaft 52 as the manual position is set. After the desired position is obtained, the shaft 11 may be pushed in to disengage the end 106 of shaft 99 from the stop 107 and the new preset position will be remembered by the control unit. It is to be realized that position of the cams 71, 72, 88, 89, 93 and 94 are held relative to the shaft 52 when in the "setting" position by the ends of the switch actuator 81, 84, 91, 92 and 96, 97, which prevent their associated cams from rotating relative to the shaft 52 as the manual adjustment is made. As soon as the manual adjustment has been made and the shaft 11 is pushed in, the memory and control system may be operated manually or to the "his" or "her" positions which have been set into the unit.

Although a mechanical linkage has been illustrated for moving the shaft 52 relative to the housing 20, it is to be realized that the shaft 52 could be moved with a flexible push-pull cable which is linked to a switch knob so as to move the shaft 52 to the left or right relative to FIG. 2 as the switch is moved to the "his" or "her" position, respectively. Alternatively, one or two solenoids could be connected to the shaft 52 to move it when the control switch is moved to the "his" or "her" position.

FIGS. 6 and 7 illustrate a modification of the invention which utilizes cams and switching means such as illustrated in the embodiment disclosed in FIGS. 1-5, but wherein the electrical circuitry is adapted for operation with a single motor which operates through a transmission and clutch arrangement such that a single motor positions the seat along three axes. U.S. Pat. No. 3,472,978, for example, illustrates a single motor system which operates through a plurality of clutches to position a seat in a plurality of directions.

The system of FIGS. 6 and 7 of the present invention utilizes a single motor in combination with clutches and switching arrangement such that a single motor positions a seat in three directions and utilizes a switch and cam arrangement as shown in the embodiment illustrated in FIG. 2. The switches are interconnected with clutches in the embodiment illustrated in FIGS. 6 and 7 and the motor runs in a first direction as, for example, clockwise, until all the functions in that direction are satisfied before reversing and running counterclockwise until the functions in the second direction are satisfied. The mechanism for moving the double cams axially relative to the switch-actuating means are similar to those illustrated in FIG. 2 and the description is not repeated herein.

FIG. 7 illustrates a motor 140 which has an output shaft 141 that supplies an input to the transmission and clutch arrangements 142. Clutch energizing means 233, 234 and 235 illustrated in FIG. 6, selectively engage the clutches and output shafts 143, 144 and 146 and are driven through the clutches by shaft 141. Shafts 143, 144 and 146 are connected to gears 149, 150 and 151, respectively, which mesh with racks on a seat 148 to position it. The shafts 156, 157 and 158 are driven by the shafts 143, 144 and 146 through the couplings 152, 153 and 154, respectively. The shafts 156, 157 and 158 provide position feedback to control the position of the cams in the control unit 147. The cams are illustrated diagrammatically as 171, 188 and 193 and it is to be realized that each of these cams represents a double cam similar to the cams 71 and 72 in FIG. 2 which may be moved axially relative to switch means so as to energize switches to drive the seat to a "his" or "her" position. FIG. 6, for example, illustrates diagrammatically cams 171, 188 and 193 which are mounted on a shaft 152. Each of the cams 171, 188 and 193 is associated with a companion cam. Cam 171 and its associated cam can engage switching means 181 and 184 mounted adjacent the cam. Cam 188 and its associated cam can engage switching means 191 and 192 mounted on opposite sides thereof and cam 193 and its associated cam can engage switching means 196 and 197 mounted on opposite sides thereof.

Switch 181 is mounted on an arm 200 which engages a contact 208 when not moved by the cam 171 or its associated cam. Contact 208 is connected to a contact 201 which supports switch actuator 184 adjacent cam 171 and is also connected to a contact 203 which supports switch actuator 192 adjacent cam 188. Contact 208 is further connected to contact 205 which supports switch actuator 197 mounted adjacent cam 193. A pair of contacts 206 and 207 are mounted adjacent the contact 200 and the contact 200 engages these contacts when moved out of engagement with the contact 208 when the cam associated with the switch actuator 181 engages it. Contact 201 is adjacent a pair of contacts 209 and 210 which it engages when the switch actuator 184 engages an associated cam. Contact 202 is normally in contact with contact 213 but may be moved by the switch actuator 191 when engaged by a cam to engage contacts 211 and 212. Contact 203 may be moved by the switch actuator 192 to engage contacts 214 and 215. Contact 204 is normally in engagement with contact 218 but when moved by the switch actuator 196 engages contacts 216 and 217. Contact 205 may be moved to engage contacts 219 and 220.

A battery E has one side connected to ground and the other side is connected by lead 221 to contact 204. The energizing winding 233 of the first clutch has one side connected to ground and the other side connected to contacts 206 and 210. A second energizing winding 234 for the second clutch is connected to contacts 211 and 215. The third energizing winding 235 for the third clutch is connected to contact 220 and 216. The windings 233 and 234 and 235 are also connected to a manual control 236. A motor 140 has one side of its armature connected to ground by lead 224 and has a first field winding 225 for driving it in a first direction and a second field winding 226 for driving it in a second direction. One side of these windings are connected to ground and the other sides are connected to contacts 229 and 230 of a motor relay 227 which has a motor relay coil 228. A motor start switch 240 has one contact connected to contact 232 which is in turn connected to the positive terminal of the battery E. The other contact of the motor start switch 240 is connected to a contact 231 which is connected to the second side of the armature of the motor 140. Terminal 229 is connected to the manual control and to contacts 217, 212 and 207 through lead 222. Contact 230 is connected to the manual control and to the contacts 219, 214 and 209 through lead 223.

The manual control has manual control buttons 237, 238, 239 for manually positioning the seat to a desired position. A "his" or "her" control knob 250 may be moved to move the cam assembly of the control unit so that the shaft 152 moves the cam assembly upwardly or downwardly relative to FIG. 6 so that the cams engage the switch actuators 181, 184, 191, 192, 196 and 197 in the manner that the cams 71, 72, 88, 89, 93, 94 engage the switch actuators 81, 84, 91, 92, 96 and 97. For example, the cams 171, 188 and 193 might be the "his" positioning cams and when the lever 250 is moved to the "his" position the cams 171, 188 and 193 will energize the switch contacts 181, 184, 191, 192, 196 and 197 such that the motor 140 runs to position the seat 148 to the preset "his" position. On the other hand, if the control 250 is moved to the "her" position the shaft 152 will be moved in the opposite direction so that the cams associated with the "her" position engage the switch actuators 181, 184, 191 and 192, 196 and 197, and the motor will be energized to move the seat to the preset "her" position.

Since the double cams and switch actuator structure are similar to that illustrated with the control system of FIG. 2, their description is not repeated relative to FIG. 6. However, the switches energized by the switch actuators associated with these cams are connected in different manner as shown in FIG. 6. The motor will run in opposite directions by respectively energizing the windings 225 and 226 of the motor through the motor relay 227.

In the particular circuit disclosed, all of the clockwise functions must be satisfied before the motor will reverse and run counterclockwise and the motor will then run counterclockwise to position any of the functions that require a counterclockwise location. When a particular shaft 143, 144 and 146 has been properly positioned its respective clutch will be deenergized.

When contacts 208, 213, 218 are normally closed and in series such that if any one is held open the field winding 226 cannot be energized and that winding 225 is energized.

Thus, direction dictated by winding 225 will first be satisfied until a home position is reached by whichever cam structure is demanding it. Then, if the others are demanding the opposite direction, winding 226 can be energized until such others are satisfied by being driven to the correct position.

It is seen that this invention provides an improved memory and control system for a power seat and although it has been described with respect to preferred embodiments it is not to be so limited as changes and modifications may be made therein which would fall within the scope as defined by the appended claims.

Claims

I claim:

1. An electromechanical memory-positioning system comprising,

an electrically energizable drive means mechanically connectable to a positionable device to move the device to a predetermined position when the device is displaced therefrom,

a movable member mechanically connected to said drive means for movement in response to movement of the positionable device,

said movable member comprising a pair of cams mounted side by side for rotation about their axes and for selective movement longitudinal of their axes,

a pair of switch actuators mounted between said pair of cams,

a pair of switch means mechanically connected to said switch actuators and electrically connected to said drive means, and

means for moving said pair of cams longitudinally of their axes such that when moved in a first direction one of said cams engages one of said switch actuators to cause said drive means to move said positionable device in a first direction to a first predetermined position or said cam engages the other switch actuator to cause said drive means to move said positionable device in a second direction to said first predetermined position.

2. An electromechanical memory-positioning system according to claim 1 wherein the other of said cams engages one of said switch actuators to cause said drive means to move said positionable device in the first direction to a second predetermined position when said pair of cams are moved longitudinally in a second direction or said other cam engages the other switch actuator to cause said drive means to move said positionable device in the second direction to the second predetermined position.

3. An electromechanical memory system according to claim 2 wherein said cams are generally disc-shaped and formed with thick and thin peripheral portions.

4. An electromechanical memory system according to claim 3 wherein said cams are formed such that the thick portion is further from the center of the cam than said thin portion.

5. An electromechanical memory system according to claim 1 wherein said pair of cams are supported on a shaft driven by said drive means.

6. An electromechanical memory system according to claim 1 comprising a support shaft, a driven gear rotatably supported by said support shaft and formed with a hub on which said pair of cams are supported.

7. An electromechanical memory system according to claim 1 wherein said pair of cams are mounted on said hub such that they normally turn with said hub, and said pair of switch actuators engage one of said cams to prevent its rotation when in a predetermined position and said pair of cams are moved in the first or second longitudinal direction, and means for energizing said driving means to move the device to a new predetermined position.

8. An electromechanical memory system according to claim 7 wherein said means for energizing said driving means comprises a manual switch.

9. An electromechanical memory system according to claim 7 wherein said switch actuators extend between said cams parallel to their surfaces and have cam-engaging portions attached to free ends thereof.

10. An electromechanical memory system according to claim 9 wherein said engaging portions are generally V-shaped such that when the cams are moved longitudinally the engaging portions will be moved outwardly from the support axis of said cams until a predetermined position is reached.

11. An electromechanical memory system according to claim 9 wherein said switch actuators are mounted on opposite sides of the support axis of said cams.

12. An electromechanical memory system according to claim 5 wherein said means for moving said pair of cams longitudinally comprises a command shaft movable from a central "off" position to a pair of "on" positions on either side of the off position and said command shaft linked to said shaft which supports said cams to move it longitudinally.

13. An electromechanical memory system according to claim 12 comprising a detent means for locking said command shaft in either of said "on" positions.

14. An electromechanical memory-positioning system according to claim 1 further including a second electrically energizable drive means mechanically connectable to a second positionable device to move it to a predetermined position when displaced therefrom, a second movable member mechanically connected to said second drive means for movement in response to movement of said second positionable device, said second movable member comprising, a second pair of cams mounted side by side for rotation about their axes and for selective movement longitudinal of their axes, a second pair of switch actuators mounted between said second pair of cams, a second pair of switch means mechanically connected to said second pair of switch actuators and electrically connected to said second drive means and means for moving said second pair of cams longitudinally of their axes such that said cams selectively energize said second drive means through said second pair of switch actuators and said second pair of switch means to position said second positionable device to a selected one of two predetermined positions.

15. An electromechanical memory-positioning system comprising,

a first clutch,

an electrically energizable drive means mechanically connectable through said clutch to a positionable device to move the device to a predetermined position when the device is displaced therefrom,

a movable member mechanically connected to said drive means for movement in response to movement of the positionable device,

said movable member comprising a pair of cams mounted side by side for rotation about their axes and for selective movement longitudinal of their axes,

a pair of switch actuators mounted between said pair of cams,

a pair of switch means mechanically connected to said switch actuators and electrically connected to said drive means and said clutch,

means for moving said pair of cams longitudinally of their axes such that when moved in a first direction one of said cams engages one of said switch actuators to cause said drive means to move said positionable device in a first direction to a first predetermined position or said cam engages the other switch actuator to cause said drive means to move said positionable device in a second direction to said first predetermined position,

a second clutch,

said drive means mechanically connectable through said second clutch to a second positionable device to move it to a predetermined position when displaced therefrom,

a second movable member mechanically connected to said second positionable device for movement in response to movement of said second positionable device, said second movable member comprising,

a second pair of cams mounted side by side for rotation about their axes and for selective movement longitudinal of their axes,

a second pair of switch actuators mounted between said second pair of cams,

a second pair of switch means mechanically connected to said second pair of switch actuators and electrically connected to said second clutch and said drive means, and

means for moving said second pair of cams longitudinally of their axes such that said cams selectively energize said drive means through said second pair of switch actuators and said second pair of switch means to position said second positionable device to a selected one of two predetermined positions.

16. An electromechanical memory-positioning system according to claim 15 wherein said drive means rotates in a first direction to satisfy all of the first, second and third positionable devices required to be moved in said first direction before rotating in another direction to satisfy any of the first, second and third positionable devices required to be moved in said other direction.