US2197391A - Press and drive therefor - Google Patents

Description

April 16, 1940.

F. C. BXGGERT, JR

PRESS AND DRIVE THEREFOR 5 Sheets-Sheet 1 Filed May 4, 1957 k ATTORNEY' A ril 16, 1940.

F. C. BIGGERT, JR

PRESS AND DRIVE THEREFOR 5 Sheets-Sheet 2 Filed May 4, 1957 INVENTOR ATTORNEY AP-ril 19405 F. c. BIGGERT, JR 2,197,391

PRESS AND DRIVE THEREFOR Filed May 4, 1957 5 Sheets-Sheet s J 'zY April 1940- F. c. BIGGERT, JR 2,197,391

PRESS AND DRIVE THEREFOR Filed May 4, 1957 5 Sheets-Sheet 4 A; ATTORNEYJ Patented Apr. 16, 1940 A E T O FI v 2,197,391 v PRESS AND DRIVE THEREFOR Florence C. Bigger-t, Jr., Grafton, Pa., assignor to. United Engineering & Foundry Company, Pittsburgh, Pa., a corporation of Pennsylvania Application May 4, 1937,"Serial No. 140,635

40mins. (creme-4s) This invention relates to heavy machinery, such as presses, shears and the like and more particularly is concerned with improved mechanism for imparting force to the'workeengaging parts there- 5 of. Heretofore, in presses, Punches, shears and the like for performing a plurality of hot or cold working operations per minute, asfor example on metal, the punch, die, blade or other tool ismoved bya crank having a relatively short throw. Usually the crank is in the form of an eccentric which is suitably driven. The working tool is ordinarily removab-ly mounted on a cross-head slidably carried in suitable guides, thecrank be- 15 ing connected to the crosswhead by a connecting rod which is pivotally connected to each.

Forceimparting mechanisrmsuch as just described, is often satisfactory for'relatively light weight apparatus. But where the force required 20 on the tool is high, for'example, a million pounds or more, the press or other machine becomes of great .size and weight. Further, the cross-head and its guides are diificult to lubricate and to cover, and the knuckle pin or other means pivotally securing the cross-head to the: connecting rod has such a small movement with a short throw that it is hard to keep properly lubricated. Moreover,- the force imparted to the cross-head by the connecting rod is ofi center relative to the work.

ciprccation thereof is ineflicient, power-consuming and wear producing so that the number of working cycles per minute is, ordinarily, relatively low.

35 Because of these and other difficulties and objections, heavy machinery of the type adapted to impart a force of, for example, one million pounds or more is ordinarily hydraulicallyoperated. However, the number of working cycles 40 per minute is necessarily limited in hydraulically operated equipment and as a result production efficiency often sufiers greatly. I

It is the. general object: of my invention to avoid and overcome the foregoing and other difiiculties bythe provision of improved mechanism for imparting force: to the work-engaging parts of relatively heavy machines adapted tocomplete alarge number of working cycles per minute.

5o Another object of my invention is to provide an improved mechanism for directly connecting a working tool and a crank, such mechanism having a minimum number of parts which are easily constructed, assembled and maintained and read- 55 ily lubricated, and which apply the Operating In addition, where the partsare heavy, rapid reto the end. of the pitman remote from the eccenforce in a substantially straight line to the Work. Another object ofmy invention is the provision of arapidly operating, relatively heavy apparatusand' particularly a press, adapted to comp-lete a large number of working strokes in one minute, 5

I each stroke delivering hundreds of thousands and even: millions of pounds of work-producing force.- Anotherobject of my invention isto provide animproved apparatus for-rapidly and eile'c tively straightening and sizing pipe. l0

Another object of my invention is the provision of improved swaging ap aratus for the'hot or cold working of metal. I

The foregoing and other objects of my invention. are achieved by the provision of apparatus including a crank, a connecting rod associatedwith the crank, a tool remo-vably carried by the connecting rod adjacent its end remote from the crank, and means associated with the tool end of the connecting rod for moving it synchronously with the crank so as to position the tool for movement to and from the same point, or substantiallythe same point, regardless of the rotary position of the crank. I

For a better understanding of my invention reference should be had to the accompanying drawings wherein Fig. 1 is a diagrammatic view of the standard cross-head, eccentric drive heretofore employedin machinery of the general type here a crank to the work in the desired direction; Fig.

4 is a diagrammatic view of a crank, a tool carried by a connecting rod, work, and one form of means for maintaining the tool end of the crank in the proper position for the direct application of force to the work; Fig. 5 is aview similar to Fig. 4 but illustrates a preferred. embodiment of the invention; Fig.1 6 is a view similar to Fig. 4 but illustrates another preferred embodiment of the invention; Fig. 7 is an end elevation of a' press incorporating the principles of the invention; and 5 Fig. 8- is a side" elevation of the pressof Fig. 7

and associated material feeding mechanisms.

Considering in greater detail the disclosure of the accompanying drawings, Fig. 1 illustrates a standard cross-head eccentric drive, suchas heretofore generally employed. "Particularly, this includes a drive shaft ll), an'associated eccentric ll operating to' drive a pitman l2; Pivotally secured to and from the work 18 on a line 19 passing through the same point 20, which in the work illustrated is the axis of the work. If a plurality of complementary dies, each operated by its own eccentric, are employed the point 20 is the same for all, as will be understood. This movement of the working tool to and from the same point is essential to a successful working operation, as will be recognized, for otherwise the work cannot be properly positioned relative to the dies.

Where, due to objections heretofore noted and in accordance with the principles of my invention, the cross-head and associated guides are eliminated from the mechanism, as shown in Fig. 2, the movement of the working tool to and from the same point is an essential. Specifically, in Fig. 2 the numeral 22 indicates a crank pivotally secured, as by a pin 23, to a connecting rod 24 having a working tool in the form of a die 25 directly associated therewith. Work in the form of a round metal section is shown at 21 and since it is round work engaged by a full face die its axis constitutes a point 28 to and from which the die 25 should move. In other words, when the pin 23 moves around in a circle as topoints 29, 30, 3! and 32, then lines drawn through these points to the point 28 should always pass through the center of the die 25.

In Fig. 3 I have diagrammatically illustrated one manner of insuring the proper movement of the connecting rod or pitman and its associated working tool. Particularly, the numeral 35 indicates a crank to which is pivotally connected, as by a pin 35, a rod 31. The rod is formed adjacent its'other end with slot 38 slidably receiving a pin 39 which defines the point to and from which the tool is moved, as for example, the center of a work-piece in the form of a round metal section 40. through points A, B, C, D, E, F, G and H any selected point on the rod, as for example point A, moves through the points B, C, D, E, F, G and H and defines a curved path indicated by the numeral 43.

Ordinarily in relatively heavy machinery adapted for rapid reciprocating tool movement and the application of hundreds of thousands or even millions of pounds of force, the mechanism I just described is not practical, as will be evident.

Hence this is not a preferred embodiment of the invention but serves to better illustrate the underlying principles of my inventive concept.

Referring now to Fig. 4 of the drawings, I have shown a mechanism including a crank 48 having a connecting rod 49 pivotally secured thereto by a pin 50. The connecting rod 49 carries a working tool,'as for example a die 5|, adapted to engage with a work-piece, such as a round metal section 52. The die is held for movement to and from a point 53 which, in the example given, is the center of the section 52 or more specifically the center toward which other dies complemental to the die 5| and similarly operated move. For the sake of simplicity only one die Now as the crank 35 is turned or working tool and its operating mechanism have been illustrated.

The desired movement of the die 5! is obtained by a cam 56 which is turned at the same angular speed as the crank 48, as by the provision of an endless chain 51. A link. 58 pivotally connected to the rod 49, as by a pin 59, carries a cam follower 60 which is held in engagement with the camby a compression spring 6|. The cam 56 is so shaped that the pin 59 defines a path 52 in the rotation of the crank 48 which path is identical to the path 43 of Fig. 3 where the crank 48 and crank 35 are identical and the distance between thepins5ll and 59 is the same as that between pin 36 and point A of Fig. 3. In other words, the center of the die 5| lies always on a line passing through the pin 50 and the point 53 regardless of the position of the crank 48.

Although mechanism of the type just described provides a perfect positioning motion for the rod 49 and for the die 5| nevertheless in relatively heavy rapidly reciprocating machinery the use of the cam and amociated mechanism is often not practical as will be recognized by those skilled in the art. Accordingly, I have shown in Fig. 5 a mechanism better adapted for the application of heavy force ona working tool andcompleting a relatively large number of working cycles per minute.

Particularlyre'ferring to Fig. 5 of the draw such as a round metal section 59 having a center point l0 toward and from which the die is moved regardless of the position of the crank 65. I control the position of the rod 61 and the die 68 by a system of linkagewhich includes a lever 12 which is pivotally connected as at 13 upon a' line 14- extending through the point 10. The lever'l2 is connected by parallel links 15 and 16 to the pin 56 and to a pin 11, respectively, so that a parallelogram is formed by the rod 61, the lever 72 and the links 15 and '15.

Now assuming that the dimensions of the parts of Fig. 5 are similar to thosev of Figs. 3 and 4, then the pin 11 if moved in exactly the right manner by the linkage would" define a curved path shown in full lines which is identical to the curved paths 43 and 62 of Figs. 3 and 4, respectively. However the linkage just describedv does not move the pin Tl in exactly this path but instead actually moves it in a path indicated by the dotted line 8|. While in Fig. 5 the path 8| actuallytaken by the pin l1 does not coincide with the desired theoretical path 80, it should be remembered that in actual practice only a part of the path Si is actuallyused in performing the work. Usually this is not more than about a 50 crank angle on each side of dead center, and the remainder of the stroke provides clearance to give timefor feeding the material worked. -By slightly changing the location of the point 13 or the pin-11' or both, the effective part of path'8l may be madeto substantially coincide with path 80. It will be understood in this connection that the showing in Fig. 5;-isactually an-exaggerated condition wherein the ,throwof the crank 65 is much greater in proportion to the rest of the' apparatus than is the casein anactual construction. Specifically in; an actual machine the throw, of the. crank, ordinarily an eccentric, is

from a fraction, ,of an' inch up .to several .inches and the length "of the connecting rod or pitman air-r59 1 at the end of the rod 8! and is, mounted for movement to and from a point 89 which in the embodiment of the invention illustrated constitutes the center of around work-piece 90/ In order that the die 88 moves to andfromthe point 89 regardless of the position of the crank a pin 92 securedto'the rod 31 should travel in a curved path 93 which like paths 43 and 62 heretofore described is theoretically and actually the correct path. v

In order to move the pin 92 in the path "03, or more particularly in a practical equivalent thereof, I provide an ecce'ntricl94' which'is surrounded. by a strap'05 'of a pitman 96 which is pivotally secured at its other end t'othe pin '92. The eccentric 94 is drivenat the same angular speed as the crank 85, as for example by-the provision of a c'onnecting chain't'l. The radius of the eccentricity of the eccentric 94 is in direct ratio to the length of the crank-85. More particularly, I have found that this ratio is substantially identical to the ratio between the dimension L marked 'in the drawings andthe dimension L. Actually when an eccentric, such as 94, is employed to control "the position of the pin .92 the path defined by the pin is indicated by the numeral 98 and as seen from the drawing this path does not exactly overlie the theoretically proper path 03. However thedimensions in the drawings have beenexaggerated' to illustrate the principle involved and in actual practice the throw of the crank 05 is much less relative to the length of the rod 8'! so that the paths 98 and 93 substantially overlie'each other in the actual. work performing portions thereof within a few thousandths of an inchwhich is close as could be obtained if actual theoretical movement were desired due to machiningtoler ances .and fits.

For a complete understanding of my invention as practically applied to a relatively heavy machine adapted to perform a large number of working cycles per minute with each one of the working cycles imparting aforce of hundreds of thousandths of pounds vor more to the work, reference should be had to Fig. 7. In this figure the numeral WI indicates generally the housing of a press which housing journals'driven shafts I02 each of which carries an eccentric I03. Surrounding each eccentric I03 is a pitman I04 which removably carries at its end remote from the eccentric a working die I05. Thedies I05 are complemental to each other and in the embodiment of my invention illustrated are three in number. They are adapted to engage with a portion of the length of a pipe I06 to size and straighten it. The uppermost pitman I04 is counterbalanced and held against the eccentric bearing by a spring blanket I0I.

Each pitman I04 is held in the proper working position for movement to and from the point I08 regardless of the position of its eccentric I03 by a system of parallel linkage similar to that particularly disclosed in Fig. 5 and heretofore described. 'Inthe embodiment of the invention shown this includes a link/H0 which is pivotally secured as by a pin I I2 to the side of the pitman. The link H0 is pivotally secured by a. pin 1 I3 to a link II4 mounted for rocking movement on 'a'pin I I5 carried by the housing IOI. Completing :the parallel linkage system is a link H6 which is pivotally secured as at II I and II8'to. the pitman I04 and to the link H4, respectively. The shafts I02 are rotated at the same angular speed by suitable mechanism which may take the form illustrated in Fig. 8 wherein a centrally apertured housing -I2II-rotatably receives a hollow hub I2I through whichthe pipe I00 ispassed.

Fixed to the hub IZI is a bull gear I 22' which is driven by a gear I23 connected to a motor I24 by a shaft I25 carrying a flywheel I26. The hub I2I likewise carries a gear I21 whichfengages with gears I28 connected to spindles I29 which are removably secured to the shafts I02; I

Positioned on each side of the press ifli, as

seen in Fig. 8, are chuck mechanisms I32 for advancing and rotating the pipe. 'The chuck mechanism I32 at the'entering side ofthe press is mounted sothatit can be adjustably positioned closer to or farther from the press Hill,

as exemplified by the dotted line showi'ngthere-.

of, so that. the pipe is moved into the press in the desired manner regardless of'its exact length and diameter and the amount of work done in the press. Each of the chuck'mechanisms'i32 is adapted to positively grip the'pipe and feed it forward a given amount when the Y dies Hid-of the press are open. 7 During the'forward feeding movement of the pipe it jiS turned through any desired arc, asfor example 60 degrees, so that the line ofthe joinder of. the dies when again closed comes at a "different point *on the "pipe than in the last closing ofthe dies. 'In actual practice the pipe is turned through an area},v

slightly less than 60 degrees due to the rotation .of:the pipe causedby the operation of the press as hereinafter described.

anisms release their grip'upon the pipe before the dies I05 engage it and the chuck mechanisms are moved back to their initial posit-ion to be readyfor another forward feeding movement of the pipe'when the dies I05 againrelease it.

The mechanisms K32 have not been illustrated in detail inasmuch as'they are known per se to the man skilled-in the art, as, for example, in "Patent No. 1,287,791.

" A novel'feature of a press constructed as just described is that in the engagement of'the'c'omplementary dieswith the'pipe I00 there is a turning of'the pipe about its own axis and through a relatively short are during the work ing operation. This is due to the fact as will be evident from the foregoing description that "each die I05 engageswith the pipe to one side of the dead center position illustrated in the "drawing. .As the eccentrics I03 move toward the .dead center .thenpipe engaged :by the ,dies turns is elastically compressed and further movement of the dies toward thepoint I08 effects plastic compressing or flow of the pipe metal up to I03 is approximately 40 The chuck mech- .the dead center position of the pitman I 04. As

the pitman moves past the dead center position and starts away from the pipe, the pipe elastically recovers an amount dependent upon the character of the metal of the pipe and after the elastic recovery is complete each die leavesthe pipe. It should be understood in this connection that the figures given are illustrative of one particular working operation and that within the principles of my invention the actual Working operation can bevaried as desired.

I have found in actual-practice with apparatus constructed as just described that the dies I05 are moved almost exactly toward and from the point Hi8 so that the theoretically correct and the actual paths of movement substantially coincide and any difference is much less than that illustrated in Fig. 5. For example, in the'mechanism illustrated, the work operated on has been represented as a fourteen inch pipe so that the length of the pitman HM is roughly five feet from the center of the shaft lllZto the bottom of the die and the distance from the pin H5 to the center of the pitman I04 is roughly eight feet. .Hence with a total stroke of approximately 1 inches by the eccentric I03 the difference between the theoretically proper path of movement of each die and the actual path of movement is negligible. I

In the actual operation of the apparatus just described pipe from about three inches to about fifteen inches in diameter and up to fifty feet long is straightened and sized in a rapid and efi'icient manner. Between about eighty 'and about one hundred fifty pipes, each fifty feet long, can be sized and straightened in an hour. The apparatus is adapted to complete up to or over fifty working cycles a minute and each die is capable of exerting seven million pounds pressure fora duration of approximately twotenths of a second. The pipe is moved step by step through the press with each step being controlled by the working stroke of the feeder but being in the neighborhood of from about one to about three feet.

While the principles of my invention have been broadly explained, they have been illustrated as employed in conjunction with a pipe sizing and straightening apparatus. It should be understood, however, that the specific example given is merely illustrative of one concrete embodiment of my invention and that the principles thereof can be employed in the construction of any relatively heavy machinery wherein the size and weight of the parts are important or limiting and wherein relative heavy working force must be imparted to a tool,'and particularly to a plurality of similarly operated tools, a number of times a minute.

From the foregoing it will be recognized that the objects of my invention have been achieved by the provision of improved mechanism for imparting relatively heavy force to a working tool or toolsa plurality -.of-times a minute; The size of the. mechanism is considerably reduced over known mechanism and the parts are adapted to. directly apply the working force in a straight line to the material worked. Lubrication of the working parts isnot diflicult and the apparatus is adapted to complete a relatively large number of working cycles per minute.

In the specification and claims the ter .crank andeccentric are intended to be used alternatively aspare the terms connecting rod and pitma comprising a press, complementary dies, a pitman mounting each die, an eccentric for driving eachpitman, and a system of parallel linkage associated with each pitman and controlling the position of the die carried thereby for movement to and from the pipe, each pitman and associated system of parallel linkage being constructed and arranged so that a line drawn through the axis of the pitman will at every degree of rotation of the eccentric pass through or substantially through the axis of thepipe.

2. Apparatus for swaging an elongated member comprising a plurality of complemental dies adapted to engagea member, and means for reciprocating the dies toward and from .the axis of the elongated member and for simultaneously oscillating the dies about the said axis of the member,,said means being constructed and arranged to turn the member slightly about substantially its longitudinal axis during the working position of the working stroke of the dies.

3. Apparatus for swaging an elongated member comprising a plurality of complemental dies adapted to engage a'member, a plurality of cranks mounting and reciprocating the dies toward and from substantially the axis of the elongated member to swage it, and means associated with the cranks to turn the dies and the member slightly about substantially the longitudinal axis of the member during the working stroke of the dies.

4. Apparatus for swaging a longitudinal member comprising a press, complementary dies, a pitman mounting each die, an eccentric for driving each pitman, and a system of parallel linkage associated with each pitman and controlling the position of the die carried thereby for movement to and from the member, each pitman and associated system of parallel linkage being constructed and arranged so that a line drawn through the axis of the pitman will during the working portion of the die stroke pass through or substantially through the axis of the member.

FLORENCE C. BIGGERT, JR.

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