US3114463A

US3114463A - Handling system

Info

Publication number: US3114463A
Application number: US654501A
Authority: US
Inventors: Fouron Pierre
Original assignee: ILE D ETUDES POUR MATERIEL DE
Current assignee: ILE D ETUDES POUR MATERIEL DE
Priority date: 1957-04-05
Filing date: 1957-04-23
Publication date: 1963-12-17
Anticipated expiration: 1980-12-17
Also published as: GB817546A; FR71168E; FR1153145A

Description

Dec. 17, 1963 P. FOURON 3,114,463

HANDLING SYSTEM 6 Sheets-Sheet 1 Filed April 23, 1957 P. FOURON HANDLING SYSTEM Dec. 17, 1963 3,114,463

Filed April 23, 1957 s Sheets-Sheet 2 ll M Dec. 17, 1963 Filed April 23, 1957 P. FOURON HANDLING SYSTEM 6 Sheets-Sheet 3 Dec. 17; 1963 P. FOURON 3,114,463

' HANDLING- SYSTEM Filed April 25, 1957 6 Sheets-Sheet 4 17, 1963 P. FOURON 3, 63

HANDLING SYSTEM Filed April 25, 1957 I i 37 38 I s Sheet s-Sheet 5 Dec. 17, 1963 P. ouRoN HANDLING sysrm Filed April 25, 1957 6 Sheets-Sheet 6 United States Patent Gffice 3,114,463 Patented Dec. 17, 1963 3,114,463 HANDLING SYSTEM Pierre Fouron, Chateuay-Malahry, France, assignor to Societe Civile dEtndes pour Materiel de Fonderie, Bagneux, Seine, France, a French company Filed Apr. 23, 1957, Ser. No. 654,501 Claims priority, application France Apr. 24, 1956 6 Claims. (Cl. 214-4) This invention relates to improved handling systems by means of which an object may be conveyed accurately from one position to another.

The invention contemplates a system which essentially comprises a frame, at least one arm pivoted on the frame, a gripping head pivoted to the arm and equipped with a gripping device, and means for pivoting the arm relatively to the frame, pivoting the head relatively to the arm, and operating the gripping device.

The gripping head may be connected to the frame, according to the invention, by a drive transmission such that the head is rotated relatively to the arm through an angle equal to the angle by which the arm is rotated relative to the frame. In this way, the gripping head will at all times retain a constant orientation in space such that the gripping device, for example, always projects downwardly from the head.

In a particularly advantageous embodiment of the invention, the means for rotating the arm relatively to the frame comprises a double-acting fluid ram having one of its elements pivoted to the frame and another pivoted to the arm, a fluid distributor valve associated with the ram, and a valve control member adapted to be actuated by the rams as the arm assumes a position such that both pivot points of the arm with the frame and with the ram element," are in alignment with the axis of the ram.

The position of the anm in which both said pivots are axially aligned with the ram, is an equilibrium position and corresponds to one of the end positions of the ram such as, for example, the fully retracted position. Should the distribution of pressure fluid flow at such time be reversed, the ram will expand but the arm, instead of returning to its original position, will move past its said equilibrium position due to inertia and continue its rotational motion under the action of the ram until it attains a position which is symmetrical with respect to its original position and is on the opposite side of the ram axis.

The arm is preferably retarded towards the end of its movement to avoid any impact which might damage the object being conveyed. For this purpose, the ram piston may be provided with suitable means which retards or darnps the movement of the arm.

Under certain circumstances, damping is superfluous and would in fact be undesirable. Means may therefore be provided to act out the damping in predetermined manner.

Two exemplary embodiments of the invention are described hereinafter for purposes of illustration and not of limitation, reference being made to the accompanying drawings wherein:

FIG. 1 is a simplified side view of a first construction provided in accordance with the invention;

FIG. 1a is a top plan view of the structure of FIG. 1;

FIG. 1b illustrates the structure of FIG. 1 in a different operational position;

FIG. 2 is a circuit diagram of the fluid flow means of the system of the invention;

FIG. 3 is a sectional view of an arm rotating ram;

FIGS. 4 and 5 are large scale views of a detail of the ram in two different positions;

FIGS. 6 and 7 illustrate a valve structure employed by the handling system, these figures being sectional views and showing different operational conditions of the valve;

FIG. 8 illustrates diagrammatically how the valve structure of FIGS. 6 and 7 is actuated;

FIG. 9 is a diagrammatic elevational view of a second constructional embodiment;

FIG. 10 is a corresponding side view of the structure of FIG. 9; and

FIG. 11 is a corresponding top plan.

As shown in FIGS. 1 and 1a, a system according to the invention essentially comprises an arm 1 pivotally mounted about an axis 2 on a frame or standard 3. Secured to the top of the standard 3 is a recessed support 4 which internally defines an oil reservoir (not shown), and pivoted to the support 4 for movement about an axis 5 is a cylinder 6 of a double-acting ram having its piston rod 7 pivoted at t5 to the arm 1. The horizontal

pivotal axes

2 and 5 lie in a common vertical plane.

Retracticn of the piston into the ram cylinder 6 causes the arm 1 to be rotated counter-clockwise about the axis 2. If the flow of pressure fluid in the ram is reversed when the arm 1 reaches its vertical position, the arm continues its rotation past its equilibrium or upper dead center position in which arm 1 is aligned with the vertical plane of

axes

2 and 5 due to inertia, and is brought to the other side of the support 4 (FIG. lb). Itis seen therefore that the arm 1 may be rotated and more by action of the single arm 6.

Adjustably secured to arm 1 is a tube 9 on which a gripping head 11 is mounted for pivotal movement about an axis 10. The head 11 has secured to it concentrically with the axis lit a pulley 12 connected by way of a drive belt, chain or the like "13 to fixed but rotatable pulley 14 of equal diameter which is secured to the frame 3 coaxially with axis 2. Due to this arrangement, the head 11 is constrained to retain a fixed angular position or orientation in space as the arm 1 is swung about the axis 2. Specifically, the head 11 depends at all time vertically from the end of arm 1.

Pivoted on the head 11 about axes 15 are two spaced arms 16 forming tongs, clamps or pincers, the arms 16 being biased towards a gripping position by springs '17. A movable stop 18 secured to the end of the rod 19' of a piston (not shown) operating in a small cylinder 26 secured on the head 11 is adapted to actuate both arms 16 in a direction to open the tongs against the action of springs 17.

As shown in FIG. 2, a line 21 connected with a source of a pressure medium, such as air, is flexibly connected with the inlets of a pair of

identical distributor valves

22 and 23. Valve 22 serves to establish selective communication of pressure line 21, either with cylinder 6 by way of a line 24- leading to the space above the piston 25 connected to rod 7, or with the oil reservoir 4 by way of an exhaust line 26. When the pressure line 21 is connected with the cylinder 6, the line 26 is connected to exhaust at 47 and the rod 7 projects out of the cylinder so that arm 1 pivots in clockwise direction (FIG. 1). The reservoir 4 communicates with the cylinder 6 via a line 27 leading to the space below piston 25 and extending to the bottom of reservoir 4. The space in cylinder 6- below the piston 25, and the line 27, are filled with oil. Hence, when the pressure line 271 is connected with reservoir 4 as in the position shown, at which time line 24 is connected to exhaust at 43, the rod 7 retracts into cylinder 6, and the arm 1 is swung upwards. Thus it is seen that the ram 6 may be described as operating on a combined, hydraulic and pneumatic principle.

The valve member in distributor 22 is operated in one sense with compressed air from line 21 through the agency of a pilot valve 28 interposed in a connecting line 29-2ta and in the opposite sense with fluid from a control line 30 and a push button valve member B. The pilot valve 28 is 49, and the valve 28 is actuated, as will be indicated, to its open position by a finger or stop 31a (see FIGS. 1 and 8) secured to arm 1, as the arm moves into the plane defined by the

axes

2 and 5. Opening the pilot valve 23 moves the distributor valve into its rightward position wherein the line 21 is connected with cylinder 6, so that arm 1 is swung downwardly as described above. A pulse of air pressure controlled by push-button valve member B and fed via line 30 on the other hand causes the valve member to be moved to its leftward position (shown in FIG. 2) and thus rotates the arm 1 counterclockwise.

At rest the movable unit of the distributor 22 occupies the extreme right position. At the beginning of the operation, a blast of air enters the conduit 30 thereby bringing the movable unit to the position shown in the drawing with the conduit 21 communicating with the conduit 26. When pin 31a (FIGS. 1 and 8) actuates the valve 28, an air blast is directed onto the left face of the movable assembly of distributor 22, thereby moving the movable assembly toward the right. As a consequence the conduit 26 communicates with the outside atmosphere and the conduit 21 is coupled to the conduit 24.

Distributor valve member 23 is adapted to connect pressure line 21 selectively with gripping head operating ram cylinder 20 by way of a line 31, or to cut off such connection. The internal movable valve member (not shown) of distributor 23 is actuated by air from line 21 in one direction by way of a line 32a and a valve 33a and in the opposite direction by way of a line 32b including valve 3311. Distributor valve member 23 has two outlets as does distributor 22 but one of these outlets is closed by a plug P.

When, for example, the valve 33a is actuated, the fluid reaches the right face of the movable unit of the distributor 23, thereby isolating the

conduits

21 and 31. Similarly, when the valve 33b is actuated, the fluid reaches the left side of the movable unit of distributor 23 so that this movable unit is moved to the right, thereby establishing a communication between the

conduits

21 and 31.

Valves 33a and 33b which are identical with valve 28, are mounted on the arm 1 and are adapted to be respectively actuated by

stops

34a and 3% carried by the standard 3 (see FIG. 1) and arranged on opposite sides of said standard. When the valve 33a is engaged by stop 34a (which is the position in FIG. 1) the valve 33a opens and causes the valve member in distributor 23 to be moved to a leftward position in which the connection between ram cylinder 20 and pressure line 21 is cut off. The tongs 16 are then closed by the action of springs 17, the cylinder 29 being connected with the exhaust at 46. When the arm 1 is rotated 180 and the valve 33b is engaged by stop 34b, a connection from pressure line 21 to cylinder 20 is established and the tongs are opened.

As shown more clearly in FIG. 3, the piston 25 has an axial appendage or shank 25a which is adapted, at the end of the outward stroke of the piston, to engage in a recess 35 formed in the head or end plate 36 of the cylinder 6 at that end of it connecting with line 27 (see also FIG. 2). With this arrangement, the flow of pressure oil from the cylinder to the sump 4 is retarded toward the end of the stroke and the movement of arm 1 is clamped as the oil must flow between the wall of recess 35 and shank 25a to reach line 27.

In order that such damping action be prevented at the beginning of the piston stroke, a by-pass connection may be provided as shown in FIGS. 4 and 5. Stated otherwise, the retarding action eifected by the trapping of fluid in recess 35 upon entry of shank 25a into recess 35 is desirable but the suction which results when shank 25a is drawn out of recess 35 is not. A by-pass is therefore provided which operates to retain the retarding effect and nullify the suction effect.

In FIGS. 4 and 5, the cylinder head 36 is provided with a bore 37 in which is positioned a valve seat 38 with which a needle valve 39 cooperates to control the by-pass. The by-pass is effectively in parallel with the recess 35 due to ducts 4t) and 41 drilled through the cylinder head 36. The needle valve member 39 is integrally connected with a small piston 42 movable in a cylinder 43 and biassed by a spring 44 in a direction tending to lift the needle valve 39 off its seat. Connecting with the end of cylinder 43 remote from the spring 44 is a line 45 which connects with the line 24, as indicated in FIG. 2.

During the initial stage of an upward or counterclockwise rotation of arm 1, the line 24 is connected to exhaust and so is line 45. The valve 39 is therefore open under the influence of spring 4-4 and the movement of the arm is not retarded (FIG. 4). At the end of the movement, however, the line 45 communicates via line 24 with the pressure line 21 and the needle valve is seated due to the action of the pressure medium in line 21 (FIG. 5). The pressure fluid in recess 35 is then constrained to flow through the space intermediate between shank 25a and the wall of recess 35 thereby damping the motion of the arm as described above.

The general operation of the system is as follows: A compressed gaseous fluid, such as air, is permanently supplied to line 21. In FIG. 1, the pilot valve 28 is in its normal closed position so that the valve 22 is in the condition reversed from the one shown in FIG. 2, and hence the air pressure is conveyed by way of line 24 into cylinder 6. However, it does not flow into cylinder 20 since the valve 23 at this time cuts off the connection between

lines

21 and 31. The arm 1 therefore is retained in the horizontal position shown in FIG. 1 and gripper 16 is held closed by springs 17.

FIG. 6 shows the valve 28 in free position. The spring 56 keeps the clack 57 supported on its seat 58. The fluid inlet line 29 is thus closed and the line 29a is exhausted by way of the passageway arranged within the clack valve stem as indicated by the arrow F.

When a pressure is exerted on ball 59 (FIG. 7), the rod 6% of the piston 61 comes to rest against the clack 57. The discharge is interrupted and the fluid thus passes from line 29 to line 29a as indicted by arrow F When the pressure on ball 59 ceases, the assembly again takes up the position illustrated in FIG. 6 due to the presence of spring 56.

With regard to the actuation of valve 28 by finger 31, FIG. 8 shows diagrammatically how the finger 31a actuates pilot valve 28.

Assuming an article has been insented between the arms of the gripper and air pressure is delivered by way of line 30, the valve 22 shifts to the position shown in FIG. 2 and connects line 21 with sump 4 and at the same time connects line 24 to exhaust. The oil reservoir in 4 then acts by hydrostatic effect on piston 25 so that the rod 7 is retracted and drives the arm 1 upwardly. As the arm reaches its vertical position, the finger 31a actuates the pilot valve .28 to apply air pressure by way of line 29a to the left end of distributor 22. This reverses the position of the distributor so that the fluid in line 24 now again acts on piston 25 since line 26 is exhausted at 47. The piston rod 7 is forced out of the ram cylinder but since the arm 1 has by now moved beyond its upper dead center position due to inertia, the arm instead of being moved back to its initial position is caused to continue its counterclockwise swing.

When the arm 1 approaches its endmost position the shank 25a projects into recess 35 and the outflow of oil from recess 35 is retarded, thus damping the rotation of the arm and averting impact at the end of the rotation.

At the end of the stroke, valve 331) is actuated by stop 34b so pressure is applied to the left end of distributor 23. This pressure places line 21 in communication with line 31. The rod 19' is displaced due to the action of the fluid supplied into cylinder 28 and causes the gripper 16 to open, releasing the article carried thereby.

Pressure next applied through line 3% will cause a reverse movement of arm 1 and will restore it to the position shown in FIG. 1, the gripper 16 being retained in open condition during this movement. The initial stage of movement of arm 1 is not retarded since needle valve 39 is raised oil its seat, so that oil can flow freely into cylinder 6 by way of lines so and 41 without having to pass through the restricted space between shank 25a and the wall of recess 35.

It will be clear from the foregoing description that the system of the invention makes it possible to grip an object, convey it and deposit it at a selected position. The time of displacement may be adjusted by an adjustable restriction valve 27 in line .27 to retard the flow of oil firom reservoir 4 into cylinder 6 or vice versa.

While the improved system may be used in handling objects of any desired character, it is panticularly well suited in connection with the operations involved in the removal or" castings and moldings and placing them on a conveyor, or in a packing system.

Where the articles to be handled are long and/or bulky, the modified construction of FIGS. 9 .to 11 may desirably be used. The construction includes, in addition to the arm 1, an auxiliary arm made of two parts Silo and Sill) connected by an adjustable coupling device or turnbuckle '51. The two arms 1 and parts 5ila53b are pivoted on a fixed shaft 52 carried by frame 3. At their free ends the arms are interconnected by a shaft 53 which is pivotable in

bearings

54 and 55 secured to the arms and which has a pulley 12 secured on it.

Adjustably secured on shaft 53 are two gripper heads 11 on each of which a gripper device 16, operable in a manner similar to the previously described gripping device, is mounted.

it will be understood that many modifications may be made without exceeding the scope of the present invention.

What is claimed is:

1. A handling system comprising a frame, an arm pivoted to the vframe about a horizontal axis between two end positions, a gripper device supported :from an end of the arm and operable to a gripping and to a releasing condition, a fluid ram actuator including a cylinder element and a piston element, one of said elements being pivoted to said frame about a horizontal axis and the other element pivoted to said arm at a point spaced from the pivot point of the arm on the frame, a pressure fluid system connected with opposite ends of the cylinder element and including a control valve, means coupled to said cylinder element and operable to reverse positions for driving the piston in opposite directions relatively to the cylinder, means coupled to the valve for placing said valve normally in position for driving said piston in a direction tending to rotate said arm away from one of its end positions, means connected to the arm for actuating said valve to its reverse position as the arm attains a dead center position in which both said pivot points are aligned with the axis of said cylinder, whereby the arm is carried past said dead center position towards its other end position, and means coupled to said gripper device and responsive to the position of the arm for operating the gripper device.

2. A handling system comprising a frame, an arm pivoted to the frame for rotation between initial and a final end position on either side of the frame, a gripper device on said arm operable to a gripping and a releasing condition, a fluid ram including a cylinder element and a piston element, one of said elements being pivoted to the frame and the other to the arm, said elements being capable of assuming a fully expanded and a fully con tracted endmost position, one of said endmost positions occurring as the aim is rotated to each of its end positions and [the other endmost position occurring as the arm passes through a dead center position in which the pivot points of the frame, ram and arm are in alignment, fluid circuit means connected with the ram cylinder for displacing the ram elements between their said endmost positions, and means actuated by the arm as it passes through its dead center position for reversing the flow of fluid through said circuit whereby the arm is carried past its dead center position towards its final position.

3. A system as claimed in claim 2, including means coupled to and restricting the fluid flow in said circuit means as the arm approaches its final position.

4. A system as claimed in claim 2 comprising interfitting boss and recess means at facing ends of said ram elements and cooperating as said elements assume the endmost position thereof which corresponds to each end position of the arm, for restricting the flow of and damping the movement of said arm, and bypass means operative only in the initial position of the arm to cancel the flow-restricting action of said interfitting means.

5. A system as claimed in claim 2 comprising a reservoir of hydraulic fluid, a source of compressed pneumatic fluid, means connecting one end of the ram cylinder with the bottom of said reservoir, the means for reversing the flow of fluid comprising a distributor valve having an inlet port connected to said source and having two outlet ports respectively connected to the other side of the ram cylinder and to the top of said reservoir, said valve comprising a valve member movable to either of two positions in which said inlet port is connected to a respective outlet port while the other outlet port is vented to exhaust said pneumatic fluid, and means operated by said arm for displacing said valve member between its positions.

6. A system as claimed in claim 5 comprising an adjustable flow restricting orifice inserted in said connection between said one end of the ram cylinder and the bottom of (the reservoir.

References Qited in the file of this patent UNITED STATES PATENTS 64,940 Bird May 21, 1867 147,949 Koethe Feb. 24, 1874 36 9,528 Kaiser "Sept. 6, 1887 1,231,257 Herr June 26, 1917 1,657,554 Schoelkopf Jan. 31, 1928 1,671,485 Pukerud May 29, 1928 1,733,987 lngle Oct. 29, 1929 1,786,608 Halstead Dec. 30, 1930 1,808,180 Schroider June 2, 1931 2,725,154 Hendricks Nov. 29, 1955 2,763,229 Sahlin Sept. 18, 1956 2,781,136 Sehn et a1 Feb. 12, 1957

Claims

1. A HANDLING SYSTEM COMPRISING A FRAME, AN ARM PIVOTED TO THE FRAME ABOUT A HORIZONTAL AXIS BETWEEN TWO END POSITIONS, A GRIPPER DEVICE SUPPORTED FROM AN END OF THE ARM AND OPERABLE TO A GRIPPING AND TO A RELEASING CONDITION, A FLUID RAM ACTUATOR INCLUDING A CYLINDER ELEMENT AND A PISTON ELEMENT, ONE OF SAID ELEMENTS BEING PIVOTED TO SAID FRAME ABOUT A HORIZONTAL AXIS AND THE OTHER ELEMENT PIVOTED TO SAID ARM AT A POINT SPACED FROM THE PIVOT POINT OF THE ARM ON THE FRAME, A PRESSURE FLUID SYSTEM CONNECTED WITH OPPOSITE ENDS OF THE CYLINDER ELEMENT AND INCLUDING A CONTROL VALVE, MEANS COUPLED TO SAID CYLINDER ELEMENT AND OPERABLE TO REVERSE POSITIONS FOR DRIVING THE PISTON IN OPPOSITE DIRECTIONS RELATIVELY TO THE CYLINDER, MEANS COUPLED TO THE VALVE FOR PLACING SAID VALVE NORMALLY IN POSITION FOR DRIVING SAID PISTON IN A DIRECTION TENDING TO ROTATE SAID ARM AWAY FROM ONE OF ITS END POSITIONS, MEANS CONNECTED TO THE ARM FOR ACTUATING SAID VALVE TO ITS REVERSE POSITION AS THE ARM ATTAINS A DEAD CENTER POSITION IN WHICH BOTH SAID PIVOT POINTS ARE ALIGNED WITH THE AXIS OF SAID CYLINDER, WHEREBY THE ARM IS CARRIED PAST SAID DEAD CENTER POSITION TOWARDS ITS OTHER END POSITION, AND MEANS COUPLED TO SAID GRIPPER DEVICE AND RESPONSIVE TO THE POSITION OF THE ARM FOR OPERATING THE GRIPPER DEVICE.