US3444718A - Manipulators - Google Patents

Description

May 20 1959 11s-rusas 3,444,718

MANIPULA'roR-s Filed aan. a. 1967 n sheet & of 2 United States Patent O U.S. Cl. 72-419 6 Claims ABSTRACT OF THE DISCLOSURE A single acting piston and cylinder assembly is connected between the peel and manipulator carriage of a manipulator and has members, comprising two cylinders and a piston movable in each cylinder, two of which are adapted to move as a single unit and to float in relation to the remaining two members. One of these remaining two is connected to the peel and the other to the carriage for movement therewith. The assembly is arranged for returning the peel to a datum position relative to the carriage after relative movement, in either direction of forging, that is parallel to the axis of the piston and cylinder assembly. Preferably the cylinders are arranged in end-to-end relationship with a common inner wall.

This invention relates to manipulators for carrying a workpiece to be forged. When forging in a series of bites it is preferable that the main mass of the manipulator should move continuously in the direction of forging, and since while the workpiece is gripped by the press tools it cannot move, the peel is mounted on the manipulator carriage so that it can move relative thereto in the direction of forging. It is known to arrange mechanical springs between the peel and carriage so that movement of the manipulator while the workpiece is held by the press tools compresses the springs, and as soon as the workpiece is released, the springs extend to return `the workpiece and peel towards a datum position relative to the manipulator.

The present invention is an improvement 4in the invention which is the subject of co-pending U.S. Patent application Ser. No. 530,420, tiled Feb. 28, 1966, by Edward Machon and Bela Bathory, and now Patent No. 3,402,592.

According to the invention of our said co-pending application, a single acting piston and cylinder assembly connected between the peel and manipulator carriage is arranged for returning the peel to a datum position relative to the carriage after relative movement in either direction of forging, that is parallel to the axis of the piston and cylinder assembly.

According to the present invention the single acting piston and cylinder assembly has members comprising two cylinders and a piston movable in each cylinder, two of the members being adapted to move as a single unit and to float in relation to the remaining two members one of which is connected to the peel and the other to the carriage for movement therewith.

Preferably the cylinders are arranged in end-to-end relationship, e.g. with a common inner wall when the cylinders form a floating unit.

Desirably two assemblies are used, being disposed one on either side of the peel.

In one arrangement of an assembly according to the invention, an hydraulic supply to the assembly is switched to pressure or drain by a control means triggered by the press so that a switch between pressure and drain occurs when the workpiece is gripped and when it is released.

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To obviate the need for such a control means, a permanent hydraulic pressure bias toward the datum position can be provided.

Preferably the return to the datum position is cushioned by using conventional cushioned cylinders for the assembly.

A preferred form of assembly according to the invention has the pistons connected to the peel and carriage and the cylinders forming the floating unit, the ends of the cylinders through which the piston rods pass being the outer ends of an end-to-end arrangement, the outer end of the carriage cylinder and the inner end of the peel cylinder having abutment faces for stopping travel of the associated pistons and the cylinder spaces between the cylinder ends and pistons being connectable to hydraulic lines so that the peel piston is returned, after a forging stroke, to a datum position in which the peel and carriage pistons are in abutment with the said faces.

The invention will now be further described with reference to the accompanying diagrammatic drawings in which:

FIGURE l is a plan view of a single acting piston and cylinder assembly connected between a peel and manipulator carriage on one side of the peel,

FIGURE 2 is an hydraulic circuit diagram of the assembly shown in FIGURE l,

FIGURE 3 is an alternative hydraulic circuit diagram of the assembly shown in FIGURE 1, and

FIGURE 4 is a diagrammatic view of an alternative arrangement to FIGURE 1 of a piston and cylinder assembly.

Referring to these figures, a peel 30 which is shown only in part is provided with a rear thrust member 1 which is free to move relative to the manipulator carriage toward or away from the press (not shown) which is positioned to the right of the figures and to move vertically. The member 1 is attached to the peel bearing assembly 31. The carriage has a thrust beam 2 which runs in vertical guides (not shown) in the carriage and is fixed relative to the carriage in the horizontal direction. Connecting the rear thrust member 1 and the thrust beam 2 is a piston and cylinder assembly which consists of a peel cylinder 4 and a manipulator carriage cylinder 5 which form a floating cylinder unit 3 and which are arranged with a common inner end wall 6 and which have slidably mounted therein a peel piston 7 and a manipulator carriage piston 8 (shown only in FIGURES 2 and 3) respectively, a piston rod 9 which is associated with the peel piston 7 being connected via a cylindrical clevis 10 and a pin 11 to the rear thrust member 1, and a piston rod 12 which is associated with the carriage piston 8 being connected via a similar cylindrical clevis pin arrangement to the thrust beam 2. A similar piston and cylinder assembly is connected between the peel and carriage on the other side of the peel.

Turning now to the circuit shown in FIGURE 2, it will be seen that the cylinders 4 and 5 have cushioned ends and the inner end of the cylinder 4 and the outer end of the cylinder 5 form stop faces for the pistons 7 and 8.

Cylinder space 13 between the outer end of cylinder 4 and the piston 7, and the cylinder space 14 between the inner end of the cylinder 5 and the piston y8 have a common hydraulic line as do the remaining pair of cylinder spaces 15 and 16. The spaces 15 and 16 are permanently connected to drain such that they are filled with oil.

Although two piston and cylinder assemblies are shown in FIGURES 2 and 3, the assemblies being disposed on either side of the peel, the operation of one assembly only `will be described as each works in exactly the same Way. The two assemblies are connected as shown for synchronous operation.

In FIGURE 2 the common hydraulic line to spaces 13 and 14 can be connected either to the pressure source or to drain (via a check valve 18) by a solenoid valve 17, the valve 17 being switched, by control means (not shown) operatively associated with the press, when the press releases the workpiece and when the workpiece is to be held. A relief valve 19 is connected to the line between the solenoid valve 17 and the cylinder spaces 13 and 14 to obviate any undue rise is pressure.

The operation of the mechanism, with the circuit shown in FIGURE 2, will now lbe described, firstly in relation to the sequence of events when the carriage is moving towards the press, i.e. to the right.

T'he sequence starts with the pistons 7 and v8 at the datum position, as shown in FIGURE 2, and with the solenoid valve 17 in its position to cause the common hydraulic line to the spaces 13 and 14 to be connected to drain, but slightly pressurized by the check valve 118 so as to load the peel positively to the datum position, the spaces and 16 being permanently at drain. The carriage constantly moves to the right thereby maintaining the piston '8 in contact with the cushioned outer end face of the press, the piston 7 -will be stationary and therefore the movement of the carriage to the right will cause the floating cylinder 3 to move to the right in relation to the piston 7. Thus the piston 7 and the outer end of the cylinder 4 approach.

On release of the workpiece the solenoid valve is triggered to connect the associated hydraulic line to the pressure supply. The pressure in the space 14 cannot affect the position of the piston 8 in relation to the cylinder 5 as the piston is in abutment with the outer cushioned end of that cylinder. However, the pressure in space 13 moves the piston 7 to the right until it again comes into abutment with the cushioned stop face of the inner end of the cylinder 4.

Then, when the workpiece is again gripped, the solenoid `valve is triggered to join the common hydraulic line to drain and the sequence is repeated.

Secondly, the sequence occurring when forging away from the press will be described.

Starting again with the pistons 7 and 8 at the datum position and the common hydraulic line at drain the carriage moves this time to the left away from the press whilst the piston 7, with the workpiece gripped, remains stationary preventing any movement to the left by the floating cylinder. Thus the piston 8 approaches the inner end wall of the cylinder 5. I When the workpiece is released, the solenoid valve 17 1s triggered to join the common hydraulic line to the pressure supply. The pressure cannot cause any movement of the piston 7 relative to the cylinder 4 as the piston is already in abutment with the inner tapered end of the cylinder 4. However, the pressure in the space 14 causes the floating cylinder unit 3 to move leftwards of the piston 8 which cannot, of course, move to the right as the carriage is advancing to the left. Thus the piston 7 is borne along by the floating cylinder unit 3 until the piston 8 comes into abutment with the cushioned outer end of the cylinder S and the pistons are again at the datum position.

As the workpiece is again gripped by the press the valve 17 changes the hydraulic line to drain and the sequence starts again.

An alternative circuit to that of FIGURE 2 is shown in FIGURE 3. In this circuit the pistons 7 and 8 are permanently biased to their datum position due to the common hydraulic line to the spaces 13 and 1'4 constantly being connected to the pressure supply. 'I'his obviates the need for control means, triggered 4by the press, for switching the common hydraulic line between drain and pressure.

The supply is fed to the spaces 13 and 14 through a check valve 20 and Control valve 21. The line between the valves 20 and 21 is connected to an accumulator 22 through a stop valve 23, an instrument control valve 24 being disposed as shown between the valve 23 and the accumulator 22. In parallel with the control valve 21 is a check valve 25 through which fluid can pass from the spaces 13 and 14.

When -forging towards the press, with the workpiece gripped, the outer end of the cylinder 4 approaches the peel piston 7 causing fluid to flow from the space 13 through the check valve 25 and thence via the stop valve 23 to the accumulator 22. The floating cylinder unit 3 is thus being pulled by the carriage against the uid pressure in the space 13. 0n release of the workpiece by the press the piston 7 will be driven back into abutment with the cushioned stop face of the inner end of cylinder 4. The datum position is thus regained and the sequence is then repeated.

When forging away from the press the piston 8 drives against the pressure in space 14, the fluid escaping as before to the accumulator 22. When the workpiece is released, the pressure in the space 14 causes the cylinder unit 3 to move in relation to the piston y8 until the latter is again in abutment with the stop face of the outer end of the cylinder 5. The datum position has thus been regained.

As the spaces 15 and 16 in FIGURES 2 and 3 are connected to drain in such a way that they are always filled with oil, a cushioning effect is provided against the return of the pistons to their datum positions.

In order to reduce the length of the assembly between the peel and manipulator carriage the cylinders 4 and 5 can be arranged side-by-side as shown in FIGURE 4 in which similar parts to those shown in FIGURES l to 3 have similar reference numerals. With such an arrangement it is necessary to duplicate one of the piston and cylinder arrangements and sandwich the other therebetween to obviate a turning moment, about the arrangements, which would obtain if only two side-by-side cylinders were employed. In FIGURE 4 pistons 12 and cylinder 5 are shown to be duplicated, but alternatively two peel pistons 9 and cylinder 4 could be provided, with a single carriage piston 12 and cylinder 5 therebetween. The arrangement of the hydraulic lines in FIGURE 4 follows that of FIG- URES 2 or 3. As with the apparatus of FIGURES l to 3, a similar piston and cylinder assembly is connected between the peel and carriage on the other side of the peel.

I claim:

1. A forging manipulator having a movable carriage, a peel and a single-acting fluid-operable piston and cylinder assembly with iirst, second and third relatively movable parts, the rst and second parts of the assembly being connected to the carriage and the peel respectively to permit relative movement between the peel and the cariage in a direction parallel to the longitudinal axis of the assembly and said third movable part defining with each of said first and second movable parts an expansible chamber, and means for controlling the supply of fluid under pressure to said chambers to cause the assembly to restore the peel to a datum position relative to the carriage after relative movement therebetween.

2. A forging manipulator as claimed in claim 1, in -which said assembly comprises two cylinders each having a piston displaceable therein, said pistons constituting the first and second parts of the assembly respectively and said cylinders being rigidly connected together to constitute the third part of the assembly.

3. A forging manipulator as claimed in claim 2 in which said cylinders are arranged in back-to-back relationship.

4. A forging manipulator as claimed in claim 3 comprising an 'additional assembly substantially identical to said first-mentioned assembly, the two assemblies being disposed on opposite sides of the peel.

5. A forging manipulator as claimed in claim 2 in which said assembly comprises a third cylinder and a third piston associated with said third cylinder, all of the cylinders being connected together in side-by-side relationship to constitute the third part of said assembly, With two of said pistons constituting one of said first and second parts of said assembly, while the remaining piston constitutes the other of said first and second parts of said assembly.

6. A forging manipulator as claimed in claim 2 in which said pistons constituting the rst and second parts of the assembly are connected by means of piston rods to the peel and the carriage respectively, with said piston rods projecting from opposite ends of a pair of cylinders arranged in back-to-back relationship and constituting the third part of the assembly, the outer end of the cylinder containing the piston connected to the carriage having an abutment face for stopping travel of the piston in said cylinder, the inner end of the cylinder containing the piston connected to the carriage having an abutment face for stopping travel of the piston in said cylinder, and said pistons abutting said faces When said peel is in said datum 5 position.

References Cited UNITED STATES PATENTS 3,274,819 9/1966 Knowles 72-*421 10 RICHARD J. HERBST, Primary Examiner.

B. I. MUSTAIKIS, Assistant Examiner.

U.S. Cl. X.R.

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