WO1981002208A1

WO1981002208A1 - A device for controlling the fluid supply to a number of consumers

Info

Publication number: WO1981002208A1
Application number: PCT/SE1981/000016
Authority: WO
Inventors: G Henriksson; S Lindahl
Original assignee: Olsbergs Hydraulic Ab; G Henriksson; S Lindahl
Priority date: 1980-01-24
Filing date: 1981-01-23
Publication date: 1981-08-06
Also published as: JPS57500077A; SE436154B; SE8000576L; EP0050620A1

Abstract

An arrangement for simultaneously controlling the fluid supply to a number of consumers with mutually different and varying needs, preferably the current supply to a number of current consumers. The arrangement includes for each one of a corresponding number of consumer connections a fluid flow varying device with an associated movable setting member. For carrying through the setting movement of at least two of the setting members these are connected to each its rotary shaft (22, 28), said rotary shafts via each its torque transmitting connection being connected to a common control handle (2). The torque transmitting connections are designed mutually independent so that, independent of the rotary position of the corresponding rotary shaft (22, 28), rotation of anyone of these shafts (22, 28) by means of the control handle can be carried through without transmitting any torque to the other shaft.

Description

A device for controlling the fluid supply to a number of consumers.

The present invention according to one aspect relates to a device for simultaneously controlling the fluid supply to a number of consumers having mutually different. and varying needs, preferably the current supply to a number of current consumers, including for each one of a corresponding number of consumer connections a fluid flow varying device with an associated movable set member, the set movement of at least two of the set members being accomplished by the connection thereof to each a rotary shaft, said rotary shafts via each its torque transmitting connection being connected to a common control handle in the form of. a swingable lever that has a pivot axis, about which it is swingably carried in a frame, one of the rotary shafts coinciding with said pivot axis. When a device of this type is more generally mentioned below the definition "control device of the kind here inteded" will be used.

An area of use for control devices of the kind here intended is in combination with and simultaneous control of a number of electrohydraulic set devices in which the position of a hydraulically moved set piston is accurately controlled by means of an electromagnetically actuated control slide for the hydraulic liquid acting upon the set piston. The coils of the electromagnets of the set devices are then the current consumers, the operating current of which shall be controlled.

In the combination described above a control device of the kind here inteded is used for controlling the hydraulic valves which are used to control the supply of hydraulic liquid to the drive motors for the different movements of a hydraulically operated implement. Examples of such implements are cranes, different types of gripping arms and the like. By means of the set pistons of the electrohydraulic set devices the valve slides of the hydraulic valves are then operated.

In known control devices of the kind here intended, intended for the area of use just described, a control handle with a one hand gripping portion carries a circular disc at its lower end which is centrally journalled to admit a universal movement of the disc and the handle. The disc covers a housing for a number of current varying devices , usually conventional po tentiometers , with a respective movable set device . The movable se t devices are so arranged in the housing and coupled to the disc that tilting of the normally upright handle in a certain direction determines which one of the set devices of the current varying devices , that shall be operated . The tilting ampli tude is decisive for the magnitude of the through current .

In these knwon devices it is not possible to avoid tha t a deep tilting of the handle and the disc also implies a certain more or less uncontrollable actuation of the set deives of adjacent potentiometers . If two functions of movement of the implement shall be activated corresponding to mutually adjacent po tentiometers it will be difficult to control the amplitude of the respective movements at simultaneous movement. A further very serious drawback of the known control devices is the fact that their design involves stress particularly of the wrist in use . This stress involves a successively increasing weary of the wrist and the forearm during a working spell , which can gradually lead to cronical pains . Great costs and efforts are therefore expended on attempts to find a suitably designed support for the forearm that shall decrease the stresses .

A first object of the invention has been to provide a control device of the kind here intended , at which the disadvantage stated above have been eliminated . According to the invention this has been attained in that the swingable lever is articulated wi th a further pivo t axis , wi th which the other rotational shaft coincides , the corresponding current varying device of which and associated set member are arranged in the swingable lever in direct connection with said other rotational shaf t .

According to a second aspec t the invention also relates to a device for simul taneously controlling the fluid supply to a number of consumers with mutually different and varying needs , preferably the current supply to a number of current consumers , including for each one of a corresponding number of consumer connections a fluid flow varying device wi th an associa ted movable set member , the set movement of a t least one of the set members being accomplished by the connection thereo f to a control handle , at the hand grip por tion of w hich there are furthermore means for operating a further set member.

At known control devices of this kind intended particularly for gripping arms the gripping function is conventionally operated by on- off-operation by means of two push buttons located at the top end of the handle and intended to be operated by means of the thumb of the operating hand. Besides the disadvantages self-evident to the man of the art the on-off-operation involves as compared with a continuous operation, the push button operation in combination with the further above described disadvantageous movements involves a further stress upon the hand and the arm.

A further object of the invention has been to eliminate such disadvantages at a control device of the last-mentioned kind.

This has been attained in that the control handle carries a bearing for a rotary shaft of the further set member, said shaft being arranged and designed with a finger grip portion, so that it is available for rotation by finger operation from the same hand, when the handle is gripped for operation of said one set member. The invention and its advantages will be described more closely below with reference to the attached drawings, on which Figures 1 and 2 in perspective views and with parts broken away illustrate a control device in left hand and right hand design, respectively, Figure 3 shows a view, partly in section, in the direction of arrows III-III in Figure 1, and Figure 4 in section more closely illustrates the design of certain details of the control device.

The control arrangements according to Figures 1 and 2 have a handle 2 with a recessed support surface 4 for the thumb. At its upper end the handle 2 carries a housing 6, in which a shaft 8 is rotatably journalled. The function and joumalling of the shaft 8 will be described more closely below. One end of the shaft 8 carries a finger operating means 10 intended for rotation of the shaft and having. a shape that generally appears from Figures 1 and 2. More particularly the finger operating means 10 has a thumb supporting tongue 12 and a fore-finger supporting tongue 14. The rotational movement of the finger operating means 10 and shaft 8 is restricted by two pins 16 extending from the housing 6, between which a further tongue 18 of the means 10 extends in a direction from the shaft 8. The member 10 is kept spring biased in a well defined middle position, where the tongue 18 is located in between the pins 16.

As seen in Figure 2 the handle 2 in use is gripped with the right hand with the thumb resting on the surface 4 and bearing against the visible surface of the tongue 12. The fore-finger is brought to bear against the surface of the tongue 14 not visible in the figure. The shaft 8 can now be rotated in the direction of the arrow A by exercising a light force on the tongue 12 by means of the thumb against the action of the spring bias. In the oppo site direction, i.e. B, operation is carried through by drawing by means of the fore-finger.

At its lower end the handle 2 carries a housing 20, in which a shaft 22 perpendicular to the shaft 8 is rotatably jour nailed. Also this shaft and its more detailed function and jour nalling will be described more closely below. The shaft 22 at its one end is rigidly connected to an arm 24 extending perpendicular ly to the shaft 22 in a direction away from the handle 2.

At its lower end the arm 24 carries a housing 26, in which a further shaft 28 is journalled, that extends perpendicularly to the shaft 22. The shaft 28 at one of its ends is rigidly connected to a frame portion 30 and also the function and journalling of this shaft will be described more closely below. The frame portion 30 thus by means of the shaft 28 carries the unit consisting of the members 2 - 26. Also movements about shafts 22 and 28 are restricted and spring biased in both directions so that the parts 2 and 24 take the rest position illustrated in Figures 1 and 2 in relation to each other and the frame portion 30.

The arrangement is principally the same for both shafts and is shown in Figures 1 and 2 for the shaft 28. The frame por tion 30 in its wall facing the housing 26 has an arcuate slot 31. In the slot a pin 32 engages that is fixedly connected to the housing 26 and located straightly below the shaft 28. Against the end of the pin 32 extending into the frame portion 30 a piston 34 guided in a bore 33 abuts from each side, said piston being spring biased by means of a screw spring 35 against the pin end 32. The spring force of the springs 35 is controllable by means of each a screw 36 arranged axially with the spring 35 and piston 34. In Figure 2 only one of the arrangements 34, 35 is more closely visible. A fixed pin 37 in the frame member 30 that extends transversely through the bore 33 in the mid plane thereof, deter mines the rest position of the rotational movement about the shaft 28. In Figure 3 control screws 38 for the bias of the shaft 22 are visible. Both screws act upwardly in the arm 24 via each a piston 40, biased by means of a spring 39, against a corresponding pin 42 extending from the housing 20 through an arcuate slit 41 in the wall of the arm 24. Movement upwardly of the pistons is restricted to the same level by means of stops. The two slits 41 are located on each its side of the shaft 22.

By means of the screws 36 and 38 separate setting of the spring force is possible in each direction about a mid position for the relative operational movement of the corresponding shaft. The rotational shafts 8, 22 and 28 each carry a control element of ferromagnetic material included in a magnetorresistor potentiometer of conventional kind. Amplification circuits which can be of a kind essentially conventional in connection with magneto resistor potentiometers, are arranged in the frame portion 30 and connected to the respective magneto resistor potentiometers. Parts of the connections extending between the frame portion 30 and the housing 26 and between the housing 26 and the housing 20 are shown at 46 and 48, respectively. Connectors for outer connection to the magneto resistor potentiometers are indicated at 50 on the underside of the frame member 30. At 51 six potentiometer controls for mutually independent setting of the amplification factor of the amplification circuits are indicated, and more particularly one potentiometer for each rotational direction of the three rotational shafts. Thereby individual setting of the operational accuracy in accordance with the character of the desired operation and for different operators is possible. In Figure 4 an axial section through the housing 6 of Figure 2 is shown. The shaft 8 is journalled in ball bearings 52 fixedly mounted in the housing 6. Within the housing the shaft 8 carries the control element of ferromagnetic material of the magneto resistor potentiometer, whereas the magneto resistors are not more closely illustrated. Said element has a peripheral ridge 54 extending helically over a portion of the circumference of the shaft. At rotation of the shaft 8 the ridge 54 shifts the constant magnetic field appearing in the magneto resistor potentiometer continuously from one magneto transistor to the other of the magneto resistor potentiomter, whereby the part resistances of the series connected magneto resistor plates are changed. This type of magneto resistor potentiometer is known per se and will not therefore be described more closely here. At 56 a coil spring located on the shaft 8 is indicated, by means of which the above mentioned bias of the mid position of the member 10 between the pins 16 is obtained.

Magneto resistor potentiometer devices corresponding to the above mentioned appear in Figure 2 for the shaft 22 and in Figure 1 for the shaft 28. The shafts are thus rotatably journalle in the respective houses by means of a ball bearing 58 at each end. The shafts in the same way as the shaft 8 carry a control element 54 of ferromagnetic material. At 60 the magneto resistor plates are indicated. The control devices shown in Figures 1 and 2 can be con nected to each six electrohydraulic set devices of the kind de scribed by way of introduction and for the purpose likewise de scribed in that connection. Each magneto resistor potentiometer controls the magnetizing currents of a pair of such electrohydrau ϋc set devices.

Each of the control devices shown in Figures 1 and 2 can consequently be used to control the current supply to the coils of the six electrohydraulic set devices, required to control a hydraulic valve with three valve slides, of which the moving direction determines the moving direction of a corresponding movement function obtained by means of a hydraulic motor and the magnitude of the stroke determines the velocity of the movement. More particularly two electrohydraulic set devices cooperate in pairs from each its end of the valve slide to operate the same and the current supply to the coils of each such pair is controlled by rotating a corresponding one of the shafts 8, 20 or 28. Rota tion in one direction then supplies current to one of the coils, whereas the other one is left without current, and vice versa. A closer description of the function of the set device and its cooperation with a hydraulic valve is given in a copending PCT application No. (ref 24766).

It should be realized that in the control device according to Figures 1 and 2 it is possible, without influencing the rota tional position of one shaft to carry through a desired rotational movement of any or both of the other shafts.

In other words it is possible with each control device to affect independently of each other three different functions of movement of an implement with accuracy and precision. As re gards the shaft 8 it should be realized that the handle 2 without difficulty can be held still in an arbitrary position of tilting with respect to the shafts 22 and 28 during finger tip operation of the operating member 10. Likewise it should be realized that there is no difficulty in keeping the handle 2 in an arbitrary fixed position of rotation with respect to the shaft 22 and simultaneously carry through thereof and mutually independent rotations of the other shafts. If the handle 2 takes an arbitrary fixed rotational position with respect to the shaft 28, also this can be held without difficulty also during rotation about the shafts 8 and 22.

The finger tip operation of the operating member 10 is carried through with small movements and requires little power from the muscles of the hand. Operation about the shaft 22 can be carried through with an almost straight wrist while using a favourable lever ratio of the hooked arm, and operation about the shaft 28 essentially implies a pure pushing or pulling movement that neither requires any bending or turning of the wrist and that likewise uses a favourable lever ratio of the hooked arm. The invention is, of course, not restricted to the embodiments shown on the drawings and described above but can be modified within the scope of the following claims. Thus it is conceivable to design the arrangement so that the movements of the three rotational axes is used for operating usual rotary potentiometers in the place of magneto resistor potentiometers. Although the principle of the invention is based upon the rotation of shafts this does not restrict the invention to the use of current varying devices, in which the movement of the corresponding set member is a rotational movement. It would be well possible to translate the rotational movement of any of the rotational shafts included in the control arrangement into a linear movement by means of a gear or other device.

It should also be realized that the area of use of the control arrangement is not restricted to that given as an example above. Genera y the arrangement can e use anyw ere it is desirable to simultaneously control the fluid supply to a number of consumers with mutually different and varying needs. In the place of potentiometers thus also hydraulic valves could be controlled.

The position of the rotary shafts with respect to each other can, of course, also be varied and it would e.g. be con ceivable to have longer or shorter distances between the two perpendicular shafts 22 and 28. Generally it can be stated that a longer distance implies more favourable working conditions as regards the movement of the arm, especially, the wrist.

Claims

Patent claims.

1. A device for simultaneously controlling the fluid supply to a number of consumers with mutually different and varying needs, preferably the current supply to a number of current consumers, including for each one of a corresponding number of consumer connections a fluid flow varying device with an associated movable set member, the set movement of at least two of the set members being accomplished by the connection thereof to each a rotary shaft (22,28), said rotary shafts via each its torque transmitting connection being connected to a common control handle in the form of a swingable lever (2,24) that has a pivot axis (28), about which it is swingably carried in a frame (30), one of the rotary shafts coinciding with said pivot axis, c h a r a c t e r i z e d in that the swingable lever (2,24) is articulated with a further pivot axis (22), with v/hich the other rotational shaft coincides, the corresponding current varying device of which and associated set member are arranged in the swingable lever in direct connection with said other rotational shaft.

2. A device according to claim 1, c h a r a c t e r i z e d in that the control handle includes a hand grip portion (2), one end of which carries a bearing (58) for one (22) of the rotary shafts, said shaft extending transversely to the direction of said hand grip portion and rigidly carrying an arm (24) extending in a direction away from the grip portion, said arm at its other end carrying a bearing (58) for the other rotary shaft (28) which in turn is rigidly connected to the frame (30).

3. A device according to claim 2, c h a r a c t e r i z e d in that the current varying devices are arranged in each its shaft housing (20,26) for the respective pivot axis.

4. A device according to any of the preceding claims, c h a r a c t e r i z e d in that the control handle (2) is designed for operating said at least two set members with a one hand grip portion, and that the control handle carries a bearing (52) for a further rotary shaft (8) of a set member of a further current varying device, said further shaft being arranged and designed with a finger grip portion (10-14) , so that it is available for finger operation from the same hand, when the handle is gripped for operation about the other rotary shafts (22,28).

5. A device according to claim 4. characterized in that the finger grip portion (10-14) is so designed that two operating fingers can rest continuously on each its portion (12, 14) thereof in order to admit instantanous change of the moving direction of the associated rotary shaft (8).

6. A device according to claim 4 or 5, c h a r a c t e r i z e d in that the finger grip portion (10-14) is located sidewardly protruding from the upper end of the handle (2).

7. A device according to any of the preceding claims, in which the fluid is an electric current, c h a r ac t e r i z ed in that at least one of the current varying devices is a magneto resistor potentiometer.

8. A device according to any of the preceding claims, c h a r a c t e r i z e d in by settable spring means (35,39) for the rotary movements of the rotary shafts for separate setting relatively to a neutral position of the spring bias towards each rotary direction.

9. A device according to any of the preceding claims, c h ar a c t e r i z e d in that amplifier circuits for the curre varying devices are arranged in the frame with control means (51) for the amplification factor of the circuits easily available arranged.

10. A device according to claim 9, c h a r a c t e r i ze in that there is one control means (51) for each rotational direc tion of at least some of the rotary shafts for mutually indepen dent setting of the setting accuracy.

11. A device for simultaneously controlling the fluid supply to a number of consumers with mutually different and varying needs, preferably the current supply to a number of curren consumers, including for each one of a corresponding number of consumer connections a fluid flow varying device with an associated movable set member, the set movement of at least one of the set members being accomplished by the connection thereof to a control handle (2), at the hand grip portionof which there are further more means for operating a further set member, c h a r a c t e r i z e d in that the control handle carries a bearing (52) for a rotary shaft (8) of the further set member, said shaft being arranged and designed with a finger grip portion (10-14), so that it is available for rotation by finger operation from the same hand, when the handle is gripped for operation of said one set member.

12. A device according to claim 11, c h a r a c t e r i z e d in that the finger grip portion (10-14) is so designed that two operating fingers can rest continuously on each its portion (12,14) in order to admit instantanous change of the moving direction of the associated rotary shaft (8).

13. A device according to claim 11 or 12, c h a r a c t er i z e d in that the finger grip portion (10-14) is located sidewardly protruding from the upper end of the handle (2).