Multi-power Control System With Single Control Stick

Abstract

This multi-power control system has a group of three controllers for determining the supply of energy to different motor means, and all of the controllers are operated from a single center stick which has different motions for actuating different controllers; for example: sliding motion, rotary motion and rocking motion. Each motion operates a different potentiometer and does not affect the other potentiometers. A spring system restores the control stick to a neutral position. Movement from the neutral position in different directions reverses the effect of the control, and the intensity of the power supply is proportional to the force applied to the stick.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

This invention is a multi-power control system with a center control stick that regulates power supply to three different motors and that also controls the speed of each motor and its direction of operation. The different motors are controlled by different motions of the stick, such as sliding motion, rotation, and rocking of the stick. Each motion can be used without affecting the control which is subject to a different motion of the stick; and it is a preferred feature that the different controls can be operated simultaneously with selective movement of each in any desired combinations including all controls operated at the same time in the same direction or in different combinations of directions and different combinations of displacement.

The invention is intended for use with bucket trucks where one motor raises and lowers the boom on which is bucket is carried, another motor extends the boom, and a third motor rotates the support by which the boom is carried. This invention can be used for controlling power shovels, graders and other equipment where different motors are used to impart different motions to the apparatus.

There is a spring system that restores the stick to a neutral position from any direction. The amount of any displacement can be felt by an operator who displaces the stick because of the increasing tension of the spring system as displacement increases. The energy supplied by each displacement of the stick is proportional to the amount of the displacement. In the preferred construction each displacement of the stick by a different motion supplies energy proportional to the amount of the displacement and therefore proportional to the force applied manually to the control stick.

In the preferred embodiment of the invention, the control stick operates potentiometers to supply signals for different valves which control the flow of energy to motors. The direction of the signal and the intensity depend upon the direction of movement of the potentiometer and the extent of the movement, respectively. By thus supplying signals to the actuators of valves which have their flow proportional to the intensity of the signal, the desired direction and speed of operation of the motor is effected.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

BRIEF DESCRIPTION OF DRAWING

In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views:

FIG. 1 is a sectional view through a multi-power control apparatus for controlling electric signals to the control system of this invention;

FIG. 2 is an enlarged end view of the apparatus shown in FIG. 1, the view being taken from the lower end of FIG. 1;

FIG. 3 is a greatly enlarged sectional view taken on the line 3--3 of FIG. 1; and

FIG. 4 is a wiring diagram for the apparatus shown in FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a control system made in accordance with this invention. A stationary housing 10 is in the form of a bushing with external threads 12 for receiving nuts 14 and 16. These nuts clamp to opposite sides of a bulkhead 18 to hold the housing 10 in a fixed relation to the bulkhead 18. There is a swivel bearing element comprising a block 20 with a generally spherical upper end portion which is held in the housing 10 by a pin 22. For purposes of better illustration, the pin 22 is shown displaced 90.degree. from its actual position. In practice, it extends rearwardly from the plane of the paper along an axis 24. The bearing block 20 is angularly movable on the pin 22 about the axis 24; and the motion is limited by shoulders 26 which strike against the bottom and face of the housing 10 when the block 20 is moved angularly in either direction about the axis 24. A single control stick 30 includes a tube 32 with a handle 34 at its upper end. The handle 34 is shaped for convenient gripping with one hand by an operator and the handle has a trigger 36 in position to be actuated by squeezing the handle. The trigger 36 operates a switch 38 located inside of the handle 34, the purpose of which will be described in connection with FIG. 4.

The tube 32 of the control stick extends into a bushing 40 to which it is rigidly secured by a pin 42. The bushing 40 is attached to the handle 34 by a bolt 44. Wires 46 extend from the switch 38 down through the handle 34 and tube 32 to a wiring panel which is not shown in FIG. 1.

The tube 32 of the control stick 30 extends through bearings 48 in the bearing block 20; and the tube 32 is free to rotate and to slide longitudinally in the bearings 48. The longitudinal sliding movement of the tube 32 is limited by pins 50 which extend through the walls of the tube 32 and for some distance beyond the outside circumference of the tube. These pins 50 are fixed in the tube 32 and one of the pins 50 is located above the bearings 48 and the other pin 50 is below the bearings 48. The control stick can move up and down with a longitudinal sliding movement until the upper pin 50 strikes against the upper end of the upper bearing 48, or the lower pin 50 strikes against the lower end of the lower bearing 48.

There is a flexible plastic boot 54 which fits closely around the tube 32 at the upper end of the boot immediately below the handle 34. The lower end of the boot 54 surrounds the upper end of the housing 10 and is secured to the housing 10 by a snap ring 56 which clamps the lower end of the boot into a circumferential groove in the top of the housing 56. The boot 54 has circumferential corrugations which permit it to lengthen and shorten in response to up and down sliding movement of the control stick 30 with respect to the housing 10.

The housing 10 has a shell 58 extending downward below the bearing block 20. The tube 32 extends downward through a substantial part of the interior of the shell 58 and there are helical tension springs 60 anchored at their outer ends to the shell 58. The inner ends of these springs 60 are connected with an extending portion 62 of the lower pin 50, and with an extending portion 64 which is secured to the pin 50 by a cross pin 65. These extending portions 62 and 64 are, in effect, unitary parts of the control stick assembly and the springs 60 hold the tube 32 of the control stick in the position shown in FIG. 3 unless a torque is applied to the tube 32 to shift it clockwise or counter-clockwise about its longitudinal axis 68.

The tube 32 and the extending portions 62 and 64 can be rocked clockwise about the axis 68 until the extending portion 62 contacts with a stop 70 at one side of an extension 72 of the bearing block 20. Likewise, the tube 32 and the extending portions 62 and 64 can be rocked counter-clockwise until the extending portion 64 strikes against a stop 74 on the other side of the extension 72. Whenever the twisting torque applied to the tube 32 is released, the springs 60 pull the parts back into the neutral position shown in FIG. 3.

Referring again to FIG. 1, the springs 60 are located in angular relation to the longitudinal axis of the control stick. Four of the springs 60 tend to pull the control stick upward and the other four tend to pull it downward. When the control stick is free and the tension in all of the springs 60 equalized, the control stick is held in the neutral position shown in FIG. 1.

When the control stick is pushed downwardly to slide its tube 32 in the bearings 48, the upper springs 60 are stretched and the lower springs 60 contract. Removal of the downward pressure permits the springs 60 again to come to equal tension by pulling the control stick back to its neutral position. Similarly, upward movement of the control stick stretches the lower springs 60 so that they will pull the control stick back to its neutral position whenever the force producing the upward movement is released.

The control stick 30 operates three different controllers. In the preferred construction each of these controllers is a potentiometer. There is a potentiometer 78 carried by a connecting element comprising housing 80; and this potentiometer has a connection to the control stick tube 32. In the illustrated construction this connection comprises a shaft 82 of the potentiometer extending into the lower end of the tube 32 and secured to the tube 32 by a set screw 84 which causes the potentiometer shaft to rotate as a unit with the tube 32. Thus rotation of the control stick 30 in the bearings 48 operates the potentiometer 78 about the longitudinal axis of the tube 32 in one direction or the other, depending upon which way the handle is rotated.

The housing 80 is supported by the connection of the shaft 82 to the lower end of the tube 32 of the control stick. Since the shaft 82 can rotate with respect to its potentiometer 78, and since the potentiometer 78 is connected to the housing 80, the shaft 82 can rotate with respect to the housing 80 also. However, the housing 80 is held against rotation by connections of another controller, comprising a potentiometer 88 with its operating connections. This second potentiometer 88 is secured to the fixed housing 80 and has a shaft 90 which extends into a crank arm 92 and which is secured to the crank arm 92 by a set screw 94 so that the crank 92 and the potentiometer shaft 90 move angularly as a unit about the axis of the shaft 90. This axis extends at right angles to a plane through the axis of rotation of the control stick. The potentiometer 88 is connected with the extension 72 of the bearing block 20 by a link 96 which connects with the crank 92 at the end of the crank remote from the potentiometer shaft 90. The link 96, by its connection to the extension 72 of the bearing block 20, prevents rotation of the housing 80 about the axis of the tube 32 of the control stick.

The third controller is a potentiometer 98, secured to shell 58 by a bracket 100. This potentiometer has a shaft 102 secured to a crank 104 by a set screw 106. The end of the crank 104 remote from the shaft 102 is connected with the extension 72 of the bearing block by a link 108.

The axis of rotation of the shaft 102 of the potentiometer 98 is preferably parallel to the direction of rotation of the shaft 90 of the potentiometer 88 but the links 96 and 108 extend substantially at right angles to one another so that rocking movement of the bearing block 20 about the axis 24 moves the link 108 lengthwise. Up-and-down movement of the tube 32 of the control stick does not impart any movement to the link 108 but as the housing 80 moves up and down with the control stick, the connection of the crank 96 to the extension 72 causes the link 96 to rock the crank 92 clockwise when the housing 80 moves upward and to rock the crank 92 counter-clockwise when the housing 80 moves downward with the tube 32.

Thus the potentiometer 78 only is operated in response to turning movement of the control stick about its longitudinal axis. Operation of the potentiometer 88 only results from sliding movement of the control stick in the direction of its longitudinal axis; and operation of the potentiometer 98 only is obtained by rocking the control stick about its axis 24.

It will be apparent, however, that any two or three of the potentiometers can be operated simultaneously in the same or in opposite directions of rotation by imparting combinations of sliding, rotary and rocking movement to the control stick.

FIG. 4 shows a wiring diagram for the potentiometers 78, 88 and 98. The potentiometer 78 has a brush 110 which moves angularly about a center axis over resistance elements 112 of the potentiometer. A center terminal 114 of the potentiometer connects with the brush 110 and the ends of the resistance elements 112 which are remote from one another are connected with other terminals 116 and 118 of the potentiometer. When the potentiometer brush 110 is in a center position, no power is supplied to either of the terminals 116 or 118. As the brush 110 is moved clockwise, it contacts with the resistance element 112 of the terminal 116 and supplies power to that terminal in increasing amounts as the brush approaches the end of the resistance element. Conversely, counter-clockwise movement of the brush 110 supplies increasing amounts of power to the terminal 118 of the potentiometer 78.

Power for all of the potentiometers is supplied through a conductor 120 from a panel board 122. This conductor 120 leads to the trigger switch 38 located in the handle of the control stick and the other side of the switch 38 is connected to the panel board 122 by another conductor 124 which connects with the center terminals of all of the potentiometers 78, 88 and 98.

The parts of the potentiometer 88 are indicated by the same reference characters as the corresponding parts of the potentiometer 78 but with a letter a appended; and similarly, the corresponding parts of the potentiometer 98 are indicated by the same reference characters with a letter b appended.

The terminals 116 and 118 are connected with contacts 134 and 138, respectively, on the control panel 122. The terminals 116a and 118a are connected with contacts 134a and 138a, respectively; and the terminals 116b and 118b are connected with terminals 134b and 138b, respectively.

From the description it will be apparent that the amount of power supplied by the potentiometer to the terminals of the control panel 122 depends upon the displacement of the potentiometers and this, in turn, depends upon the displacement of the control stick in the various directions of its selective movement. These variable power supplies are used to operate actuators for proportional flow valves that control the working fluid to the motors which the control stick is designed to regulate.

On a bucket truck, the up and down sliding movement of the control stick can be used to raise and lower the boom by displacing the potentiometer 88 one way or the other. Rotation of the structure that carries the boom so as to swing the boom about a vertical axis, can be controlled by rotating the control stick to displace the potentiometer 78 one way or the other, depending upon the desired direction of rotation. Extension of the boom to move the bucket closer to or further from the work can be accomplished by rocking the control stick in the direction of its longitudinal length to displace the potentiometer 98 in the direction to obtain the desired movement of the bucket.

The preferred embodiment of the invention has been illustrated and described, but changes and modifications can be made and some features can be used in different combinations without departing from the invention as defined in the claims.

Claims

What is claimed is:

1. A multi-power control system comprising a plurality of different controllers, including a first controller and a second controller, each of which controls a supply of energy and each of which has displaceable means for changing the energy supply in proportion to the degree of displacement of said means, a single control stick, a connecting element at one end movable longitudinally with the stick, a bearing element through which the control stick extends and in which said control stick has selective longitudinal and angular movements, the bearing element being angularly movable about an axis transverse of the axis of the stick to provide the rocking movement of the stick, one of the controllers being carried by one of the movable elements, a fixed element spaced from the bearing element, one of the controllers being carried by one of these spaced elements, a first link connecting one of the movable elements and the first controller, said first link extending in the same general direction as the longitudinal movement of the control stick, whereby said first link operates the first controller in response to longitudinal movement of the stick in said bearing element and is unresponsive to said angular movement of the stick, a second link connecting one of said spaced elements and the second controller, said second link extending transverse of the longitudinal movement of the stick and in the same general direction in which the stick moves when it rocks with said bearing element whereby said second link operates the second controller in response to said angular movement of the stick and not to the longitudinal movement.

2. The multi-power control system described in claim 1 characterized by the bearing element having a surface on which the stick has sliding the control system for said other controller and link, one of which is connected to said connecting element and the other of which is connected to structure that is longitudinally fixed with respect to the bearing element, the link extending generally parallel to the longitudinal axis of the stick and holding said connecting element against rotation with the stick, but said link projecting at such an angle to a displaceable portion of said other controller so as to operate such other controller in response to the axial movement of the stick.

3. The multi-power control system described in claim 1 characterized by one of the controllers having a neutral position and being movable selectively to either side of its neutral position, and said controller having the neutral position being effective to reverse its control effect when moved to different sides of its neutral position.

4. The multi-power control system described in claim 1 characterized by each of the controllers being a potentiometer in an electric circuit of a motor which it controls.

5. The multi-power control system described in claim 4 characterized by momentary contact switch means having a manually operated actuator at an end of the stick which is gripped by an operator of the stick.

6. The multi-power control system described in claim 1 characterized by a housing for said bearing, and a boot connected at one end of the stick above the bearing and to the housing on the lower end of the boot, said boot having circumferentially extending folds therein and being flexible so that it can change in length to accommodate longitudinal sliding movement of the stick.

7. The multi-power control system described in claim 1 characterized by the stick having rotary movement about its longitudinal axis, a third controller carried by said connecting element and operated in response to said rotary movement of the stick, the connecting element being movable with the stick during the longitudinal and tilting movements of the stick so that there is no relative movement of the third controller and the stick during said longitudinal and tilting movements of the stick.

8. A multi-power control system comprising a plurality of different controllers, each of which controls a supply of energy and each of which has displaceable means for changing the energy supply in proportion to the degree of displacement of said means, a single control stick, a bearing through which the control stick extends and in which said control stick has selective longitudinal and angular movements, connections between the displaceable means of each controller and the single control stick, the connection to one controller being responsive to longitudinal movement of the stick in said bearing and not responsive to said angular movement of the stick, and the connection of another controller being responsive to said angular movement of the stick and not to the longitudinal movement, and characterized by there being three controllers, each of which has its displaceable means angularly movable about an axis, the connections including one connection through which angular movement of the stick about its longitudinal axis operates a first controller through an angle proportional to the angular movement of the stick about its longitudinal axis, a second bearing on which the first bearing is angularly movable about an axis extending transversely of the longitudinal axis of the stick and about which the stick rocks, a connection through which the rocking of the stick operates a second controller through an angle proportional to the angle of rocking of the stick, the connections including also another connection through which the sliding movement of the stick operates a third controller through angular movement proportional to the degree of sliding movement of the stick, all of said connections between the stick and the controllers being connected to the stick and controllers at the same time, but the connection to each of the controllers being oriented and connected so as to be inoperative to displace its controller in response to the movement of the stick that operates one of the other controllers, and further characterized by the connection operated by rotary angular movement of the stick being in alignment with the longitudinal axis of the stick, the connection operated by rocking movement of the stick including a link extending transverse of the longitudinal axis of the stick and a crank at an angle to the link, and the connection operated by sliding movement of the stick including a second crank having operating means which are movable as a unit with the stick, and a link connected at one end of the second crank and at the other end to an anchor fixed with respect to the longitudinal axis of the stick.

9. A multi-power control system comprising a plurality of different controllers, including two controllers, each of which controls a supply of energy and each of which has displaceable means for changing the energy supply in proportion to the degree of displacement of said means, a single control stick, a connecting element at one end movable longitudinally with the stick, a bearing element through which the control stick extends and in which said control stick has selective longitudinal and angular movements, means holding the bearing element against movement lengthwise of the stick and against rotation about the longitudinal axis of the stick, one of the controllers being carried by said connecting element and connected with the stick for operation by rotation of the stick about its longitudinal axis, a link for operating the other controller, space within the control system for said other controller and link, one of which is connected to said connecting element and the other of which is connected to structure that is longitudinally fixed with respect to the bearing element, the link extending generally parallel to the longitudinal axis of the stick and holding said connecting element against rotation with the stick, but said link projecting at such an angle to a displaceable portion of said other controller so as to operate such other controller in response to the axial movement of the stick.

10. The multi-power control system described in claim 9 characterized by the stick being rotatable in the bearing element about the longitudinal axis of the stick, and a bearing surface about which the bearing element has rocking movement about an axis extending transversely of said longitudinal axis.

11. The multi-power control system described in claim 9 characterized by a third controller and connections by which the third controller is operated in response to rocking movement of the stick about an axis extending transversely of the direction of the sliding movement of the stick.

12. The multi-power control system described in claim 11 characterized by spring means that converge in three dimensions and from opposite directions and connected with the stick and with fixed anchors for returning the stick to its original position after any displacement or combination of displacements of the stick from said neutral position.

13. The multi-power control system described in claim 12 characterized by there being eight springs connected with portions of the stick at one end, a housing enclosing the springs, each of the springs being connected at its other end with the housing and the connection with the housing comprising the fixed anchor for each spring.

14. The multi-power control system described in claim 9 characterized by all of the controllers having neutral positions and being movable selectively to either side of their neutral positions, and all of the controllers being effective to reverse their control effects when moved to different sides of their neutral positions.