US3722712A

US3722712A - Workpiece transfer devices

Info

Publication number: US3722712A
Application number: US00202856A
Authority: US
Inventors: H Knierim
Original assignee: Est Aciers Fins
Current assignee: Est Aciers Fins; SOC DES ACIERS FINS de l EST FR
Priority date: 1970-12-08
Filing date: 1971-11-29
Publication date: 1973-03-27
Anticipated expiration: 1990-03-27
Also published as: DE2160574B2; FR2123085B1; GB1357764A; FR2123085A1; DE2160574A1; IT943758B

Abstract

This device for transferring workpieces or blanks, notably in a forging press, from one working station to another, in a sequence of working stations comprising for example forging dies, is collapsible and comprises a plurality of clamps adapted to grip the blanks, release them completely from the dies and move same laterally through a distance corresponding to the gap between adjacent dies, and lay the blank into the next die, and eventually resume their initial position. Said clamps are designed to move forwards as their jaws are closed through a toggle mechanism.

Description

States Patent Knierim 1 Mar. 27, 1973 [54] WORKPIECE TRANSFER DEVICES FOREIGN PATENTS OR APPLICATIONS Inventorl Henri Kniel'im, Boulogne'Billan- 729,828 12 1942 Germany .214 1 BB court, France [73] Assignee: Societe Des Aciers Fins De Lest, Primary EXami'1eTGefald Fol'lenla Boulogne-Billancourt (I-Iauts de Assistant Examiner-George F. Abraham Seine), France Attorney.-Richard K. Stevens et al.

[22] Filed: Nov. 29, 1971 [57] ABSTRACT [21] Appl. No.: 202,856

This device for transferring workpieces or blanks, notably in a forging press, from one working station to [30] Foreign Applicaflon Prinmy Dam another, in a sequence of working stations comprising Dec. 8, 1970 France ..7044l22 for example forging dies, is collapsible and comprises a plurality of clamps adapted to grip the blanks, [52] US. Cl. ..2l4/l BB release them completely from the dies and move same Cl- ..B23q laterally through a distance corresponding to the gap [58] Field Of Search ..214/1 BB, 1 B between adjacent dies, and lay blank into the next 56 R f d die, and eventually resume their initial position. Said 1 e erences Cue clamps are designed to move forwards as their jaws UNITED STATES PATENTS are closed through a toggle mechanism.

3,432,042 3/1969 Bautz ..2l4/1 BB 5 Claims, 8 Drawing Figures 4 A1 A2 A3 I A4 B2 T3 T3 T5 r2 J 77 F 1 1 H C V E PATENTEUHARZYISYS 3,722,712

SHEET 2 [IF 4 PATEWEDHARZY 1975 SHEET 3 OF 4 B0 DU 00 DD WORKPIECE TRANSFER DEVICES The present invention relates to a device for transferring workpieces or the like between successive treatment or machining stations, and more particularly to an apparatus for transferring workpieces or blanks in a forging press of the multiple-die type, wherein the various dies correspond to successive forging operations to be performed on each workpiece r blanks.

The device according to this invention is therefore designed for mechanically handling notably blanks between the various dies of a forging press, and also for automatically discharging the cutting burrs and beards.

According to a preferred form of embodiment the transfer device according to this invention constitutes a separate self-contained unit mounted to a pivoted support whereby it can be retracted to an inoperative position.

This device comprises a plurality of clamps for gripping the blanks, stripping or releasing these blanks completely from their dies, moving said blanks laterally by a distance corresponding to the interval existing between two adjacent or successive dies, and depositing the blank into the next die and eventually returning the clamps to their initial position.

Preferably, the number of clamps will correspond to the number of dies to afford a complete automation of the transfer steps, from the first die to the lastone.

The clamps equipping the transfer device according to this invention are therefore of a particular type wherein the closing movement of the clamp jaws is attended by a forward or feed movement of the clamp. These clamps are constructed according to the lazytongs or toggle principle affording a considerable constructional compactness.

The transfer device and the clamp means of this invention will now be described more in detail with reference to the accompanying drawings illustrating diagrammatically by way of example a typical form of embodiment of the invention. In the drawings:

FIG. 1 is a plane view from above showing the transfer device assembly;

FIG. 2 is an elevational view of the vertical feed mechanism of the transfer device;

FIG. 3 is a plane view from above of the transfer device in its operative position in relation to the dies;

FIG. 4 is an elevational view showing the pivoted arms supporting the transfer device;

FIG. 5 illustrates a clamp according to this invention in its open position;

FIG. 6 illustrates the same clamp in its closed position;

FIG. 7 is a diagrammatic illustration of the clamp, for explaining its mode of operation, and

FIG. 8 is a more detailed view of the clamp mechanism driving system.

In the specific form of embodiment illustrated the number of clamps, which corresponds to the number of dies, is four, i.e. clamps A,, A A and A,. These clamps are carried by four adjustable horizontal arms 8,, B B and 8,, respectively (FIG. I) mounted to a carriage C (FIGS. 1 and 2) adapted to travel vertically and responsive to a double-acting fluid-operated actuator V (FIG. 2), this carriage being guided during its travel by a vertical member or slideway E (FIG. 2) comprising ball sockets D (FIG. 2) also mounted to a translation carriage F.

The distance d between the axes of adjacent clamps is selected to correspond to the gap between successive dies or die pitch. It will be noted that the overhang mounting of the clamps in the direction of their mutual alignment in relation to the superposed arms B B and B B is advantageous in that the carriage can be constructed with overall dimensions smaller than those of the clamps proper.

The translation carriage F (FIG. 1) permits of displacing the clamps laterally, i.e. in their alignment direction. Its stroke is equal to the die pitch and thus permits of moving clamp A for instance, to the position previously occupied by clamp A while clamp A takes the previous position of A and this clamp A assumes the previous position of clamp A The movements of carriage F are controlled through actuator G (FIGS. 1 and 2) and guided by slideways H rigid with a supporting or bed plate P. This plate P which, after a suitable vertical adjustment, is secured and locked in position by means of studs on the die carrier, is also equipped with hydraulic means for controlling and regulating the actuators.

The complete device mounted on said supporting plate P is collapsible to facilitate the access to the dies. To this end, the device is secured to one end of a pivoted arm L which, in the typical form of embodiment illustrated (FIGS. 3 and 4) consists of two sections pivoted at three points. This arm L is secured at its opposite end to the frame structure of the press S. It is shown in thick lines, in FIG. 3, in the operative position of the transfer device and in chain-dotted lines in its retracted position freeing the access to the die.

The hand lever M is provided for adjusting the vertical position of the pivoted arm and therefore the set of clamps in relation to the dies (FIG. 4).

In the form of embodiment illustrated, which is consistent with the conditions required for releasing the clamp carrier assembly corresponding to the diagram of FIG. 3, the arm comprises three pivot pins K K and K and is comprised of two sections N, and N this last section N being bent to provide the maximum free space or clearance about the frame structure of the press in the retracted position of the device.

The clamps according to this invention, which are used for transferring the blanks or like workpieces from one die to another, are characterized in that they are fed forwards as theirjaws are being closed, thus sparing a travel of the clamp supporting carriage C.

Clamps having this specific feature are already known, but those implemented in the present invention are advantageous in that their construction is more compact and their gripping or clamping efficiency is greatly enhanced.

The structure of the clamp according to this invention is illustrated diagrammatically in FIG. 7, as far as its principle of operation is concerned, and in FIG. 5, 6 and 8 for its mode of construction.

It comprises a pair of movable jaws M and M pivotally connected at 1 and la to links 10, and at 2 and 2a to links 13, the other ends of these

links

10, 13 being pivoted at 3, 3a and 4, 4a, respectively, to the

arms

5 and 5a of a fork shaped support of which the central shank comprises a central bore 8 constituting the cylinder of a double-acting hydraulic actuator in which a piston 9 is slidably mounted.

Secured to this piston 9 is a rod 11 having its outer end rigid with a trunnion supporting head 7 (FIGS. 7 and 8) to which links 6 have one end pivotally connected, the other ends 12 of these links 6 being pivotally connected to

other links

10 and 13, respectively.

These clamps operate as follows:

In the inoperative position (illustrated in FIG. the clamp is open, due to the action of said actuator, the piston 9 thereof being urged to the right (as seen in FIGS. 5, 6 and 7) of cylinder 8.

The double-acting actuator of each clamp is controlled to this end by a pair of fluid pipe lines T and T (clamp A), T and T (Clamp A T and T: (clamp A T and T, (clamp A as shown in FIG. 1.

Hydraulic fluid is fed through the aforementioned pipe lines to move piston 9 to the left (as seen in FIGS. 5, 6 and 7), whereby the trunnion supporting head 7 is moved back and the

links

10 and 13 are caused to form an X, thus combining a forward movement ofjaws M andM with the closing thereof (FIG. 6) while exerting, due to the specific structure of this toggle mechanism, a very powerful clamping action of said jaws on the workpiece disposed therebetween.

The transfer device proper will now be described with reference to FIG. 3.

After a billet or other blank has been deposited as a first operation by means of a conveyor not comprised in the transfer and forging means, the billet or blank is slightly lifted by the press ejectors.

Then the operator starts the transfer cycle proper by actuating the clamps. Clamp A, is actuated and grips the blank burr.

After a certain time lag, the clamps are raised by the carriage C driven by actuator D to permit a complete release of the blank from the impression of die 0,.

At the end of the lifting step the carriage F controlled by actuator G is moved laterally through a distance equal to the die pitch, thus moving the clamp A to the position previously occupied by clamp A and positioning the blank above the impression of the second die Q At this moment the carriage C is lowered and the clamps are opened while they recede and allow the blank to drop into the impression of the next die Q Upon completion of the forging operation and when the transfer device has resumed its initial position, the blank is picked up by the next clamp A of the transfer device which, after another cycle of operation, will drop it into the third die Q At this time, another billet is introduced at the first station for performing the first operation thereon. This billet, after the forging operation, will be transferred by the clamp A of the transfer device as described hereinabove.

During this same cycle, the clamp A will transfer the blank from the third clamp to the fourth blank 0,.

A fresh billet is introduced every other cycle: therefore, two blanks are constantly transferred simultaneously.

Similarly, considering the specific case of a forging press, it would be possible to introduce a billet at each cycle and thus have four blanks transferred during the same operation.

On the other side of the dies a movable bar R operating in synchronism with the front transfer is provided for supporting the rear end portions of the blanks of which the insufficient rigidity of the burrs makes it hardly possible to pick up these blanks by means of the front clamps alone. This movable bar is operated by means of suitable hydraulic actuators and performs simultaneous longitudinal and approach movements. The approach movement takes place in a horizontal plane under the control of a parallel-motion system Z (FIG. 3). The other movement takes place in a vertical plane and is controlled by a similar parallel-motion system (not shown) so as to perform the longitudinal feed and the upward movement of the movable bar.

These movements are synchronized with the clamping and travel or feed movements of the clamps. The edges of the workpieces or blanks slide subsequently along the bar R during the lateral movement.

The workpiece or blank transfer device according to the present invention as described hereinabove and illustrated in the attached drawing is advantageous, in comparison with hitherto known transfer systems, in that the control means and the number of motions are greatly simplified, that it is particularly compact due to its retractibility, and that its light weight permits of securing it for example to the frame structure of a press S, thus making is possible to dispense with floor base plates or like mountings; furthermore, this device is extremely versatile and adjustable, notably through the possibility of adjusting the clamp supporting arms B and B for adapting the device to miscellaneous applications.

Of course, various modifications and variations may be brought to the structure shown and described herein, without departing from the basic principles of the invention assetforth in the appended claims.

What is claimed as new is 1. Device for transferring workpieces or the like between successive working stations, which comprises a series of aligned clamps mounted on a first carriage movable in a horizontal direction, the distance between adjacent clamps being constant and equal to the gap between two successive working stations, the complete series of clamps being adapted to be moved by means of another carriage supporting said first carriage and its driving mechanism, said other carriage being vertically movable, thedevice being characterized in that the clamps and carriages constitute a separate unit mounted on one end of a pivoted arm secured to the frame structure of a press whereby said unit is collapsible to an inoperative position to facilitate the access to said working stations.

2. Device accordingto claim 1, characterized in that said clamps are mounted on horizontally adjustable arms forming a part of said first carriage, and that the pivoted arm aforesaid is associated with means for adjusting the vertical position of the pivoted arm, said last-named means being located at the mounting of said pivoted arm on said frame structure.

3. Device, according to claim 2, characterized in that said clamps overhang the ends of said arms and are. aligned in a direction transverse to said arms.

4. Device according to claim 1, characterized in that it is used for transferring workpieces or blanks of relatively moderate rigidity in combination with a movable means of at least one link, whereby these links cross each other as an X" in the closed position of said jaws, the clamp assembly further comprising a trunnion-supporting head operatively connected in turn through other links to said first-named links, and a doubleacting fluid-operated actuator operatively connected to said trunnion-supporting head to move it and thus con trol said links by varying the angle formed therebetween.

Claims

1. Device for transferring workpieces or the like between successive working stations, which comprises a series of aligned clamps mounted on a first carriage movable in a horizontal direction, the distance between adjacent clamps being constant and equal to the gap between two successive working stations, the complete series of clamps being adapted to be moved by means of another carriage supporting said first carriage and its driving mechanism, said other carriage being vertically movable, the device being characterized in that the clamps and carriages constitute a separate unit mounted on one end of a pivoted arm secured to the frame structure of a press whereby said unit is collapsible to an inoperative position to facilitate the access to said working stations.

2. Device according to claim 1, characterized in that said clamps are mounted on horizontally adjustable arms forming a part of said first carriage, and that the pivoted arm aforesaid is associated with means for adjusting the vertical position of the pivoted arm, said last-named means being located at the mounting of said pivoted arm on said frame structure.

3. Device according to claim 2, characterized in that said clamps overhang the ends of said arms and are aligned in a direction transverse to said arms.

4. Device according to claim 1, characterized in that it is used for transferring workpieces or blanks of relatively moderate rigidity in combination with a movable supporting bar adapted to act as a bearing member to the ends of said workpieces or blanks which are opposite to said clamps, means being also provided for synchronizing the movements of said bar in relation to the clamp movements.

5. Device according to claim 1, characterized in that said gripping and tightening clamps comprise on jaws which move forward as they are closed, mounted on a fork shaped fixed support having two projecting arms, the two movable jaws of each clamp being each operatively connected to the arm on the opposite side by means of at least one link, whereby these links cross each other as an ''''X'''' in the closed position of said jaws, the clamp assembly further comprising a trunnion-supporting head operatively connected in turn through other links to said first-named links, and a double-acting fluid-operated actuator operatively connected to said trunnion-supporting head to move it and thus control said links by varying the angle formed therebetween.