US1373571A - Drawing-press - Google Patents

Description

G. M. SMITH. j I DRAWINGIIIESS.Y APPLICATION FILED MAY 24, 1920.

lomo' II )il I WITNESS y ATTORNEYS UNITED STATES PATENT OFFICE.

GEORGE M. sMIrH, or CANTON, OHIO, AssIGNOR To A. o. SMITH CORPORATION, or MILWAUKEE, WIscoNsIN, A CORPORATION or NEW YORK.

'DRAWING-PRESS.

To all whom zt may concern.'

Be it known that I, GEORGE M. SMITH, a citizen of the United States, and a resident of the city of Canton, county of Stark, and State of Ohio, have invented a certain new and useful Improvement in Drawing- Presses, (Case #148,) and I dodeclare the following to be a full, clear, and exact description thereof, such as will enable others skilled, in the art to which the invention pertains to make and use-the same, reference being had to the accompanying drawing as illustrating one `construction in which the invention has been'embodied.

The invention relates to presses which are designed to draw metal plates or blanks into -v flanged bars.

The larger uses of such presses involve their employment in the production of side bars for automobile frames, which side bars as is well known, are formed with a vertical web with flanges standing perpendicular to the plane of the web. n some types of automobiles, the side bars have a considerable length, and the practical production of such lengthy bars necessitates the erection of y presses of extreme dimensions. The output of presses .of the type ordinarily used in this work is restricted, by reason Wof the time required tofeed the blanks into the ress and withdraw the flanged bars aftert e drawing operation has been completed. The

actual time consumed in performing the drawing operation is but a fraction of the time cycle required for one complete operation of the press.

The presses employed for drawing length flanged or channel bars from sheet meta are -usually of the type known as end feed. Such presses are provided with a bed supporting the matrix at or near the longitudinal center line of the press, and a recipro- V eating head which carries the complemental diemember or punch. Straining rods arranged and fixed in parallel rows at each side of the press, serve to tie the crown of the press to the bed thereof, the reciprocating punch carrying head being guided by the said straining rods. The latter resist the expansive force generated in the operation of the eccentrics, which are used to impart motion tothe reciprocating punch lcarrying head. In the type of drawing press just described, the blanks to be drawn are Y l vSpecification of Letters Patent. 4Patented Apr, 5, 1921. Application mea May 24, 1920. serial No.`3sa,9s4.

fed into the press at one end thereof, and after being. shaped by the die members of lthe press, are withdrawn at the other end operation, and the cycle of intermittin'g u movement is repeated,` as described. The operations of feeding the blank, correctly positioning the same with reference to the die members of the press, and withdrawing the ianged bar are manually performed in most presses, and the output of the press is necessarily dependentupon the activity and sk1ll of the crew of pressmen. The time requlred for manually shifting the clutch 'into and out of operation is but a momentary y y have referred Ato the straining rods as being arranged in parallel rows at the side ofthe press. Each of such rows is composed of a plurality of straining rods, usually five or six or more, and these are spaced throughout the length of the press so as to secure,

as far as possible, an even distribution of kthe' pressure exerted in the drawing operation, and confine the'expansive pressure of the press'within the limits of the elasticity of its construction. rI`heemp1oymentof the several straining rods in each row, as described, fenders the press inaccessible from the sides for the blanks thereto an bars therefrom, and necessitates such operationsto be performed at the ends of the press. l v

Drawing presses open at the sides and designed to permit the feeding of the blanks and withdrawal of the side bars have been used, but in such constructions it has been necessary to construct the crown of the press as well as the base thereof, in massive pro- (purpose of feeding the portions, and to tie the crown to the base by means of straining rods of such diameter and tensile strength as to successfully reslst the expansive pressure generated by the ecremoving the flanged centric mechanism-in actuating the punch to perform the drawing operation. .The use of the drawing press open at both sldes,

' respondingly reduced, and only the bed and.

as described, has enabled -the press to be` continuously operated, the crew of expert pressmen having ample time to feed a blank into the press for the dra-wing operation and to remove the flanged bar therefrom, during the retraction of the drawing head in the cycle of movement .of the latter. This l last described construction of press has 1n- This more modern construction of drawing.

presses eliminates the crown piece with its supporting end frames or fixed .straining rods, and provides a most efficient means for lubricating such mechanism by means of a constant shower or spray of oil which falls upon the operating shafts, gears and cams. In addition, the height of the press is corthe reciprocating drawing head, together with the vertically movable straining rods which carry the latter, are visible above the floor line.l

My improved drawing press embodies in its construction the desirable features residing in both forms ofthe older types of presses, in that I am enabled to build an open-side press, and at the same time secure the strength of construction which follows the use of distributed straining rods which carry the expansive force generated in the operation of the press. lIn constructing my improved press, the bed thereof has a width sufficient to receive a matrix placed outside of the'parallel rows of straining rods, and the reciprocating die carrying cross head carried by the straining rods has a width corresponding to that of the bed of the press. In the preferred construction, the rows of straining rods are -separated as in the first type of press described, by a space which will receive a third matrix and its complemental die member.

It is my purpose to employ the open-side construction in drawing flanged bars of lesser length, and such as will not require the full expenditure of the power of thev press. Crews of pressmen may work at each side of the ress, which will be continuously operated. y purpose in providingthe central arrangement of die members is to enable the press to be employed in the production of side bars of a length exceeding'that of the press, and which require a second operation to complete their formation. I propose also to use this central arrangement in the"- production'of heavier flanged bars from blanks of such gage as to' more. nearly approach the compressive force of the press. In using the central set of diemembers, the press will be intermittingly operated, if the blanks be fed and the flanged .bars be re'- moved manually.

In the older type of drawing presses, that first described by me, the punch carrying head was actuated by a single eccentric shaft, the thrust of which was resisted by the crown piece of the press. At the time that the rotating eccentrics reached the position of their greatest'foutward throw, an angular pressure was .developed by the drawing headbearing against the straining rods in the direction of the thrust of the eccentrics, and a violent rocking strain was imparted to the press structure. It was therefore difficult to give a parallel motion tothe drawing head, and the straining rods were subjected to greatly increased friction.

In place of the single eccentric shaft heretofore generally used, I propose to employ apair of parallel eccentric shafts, arranged at the sides of the longitudinal center line of the press, and to gear such eccentric shafts so as to rotate them synchronously and thus impart a parallel motion to the drawing head during its entire reciprocation. The arrangement of the dies on the face of the drawing head without regard to the longi= tudinal center line thereof, does not disturb such parallel motion, the pressure of the eccentrics upon the drawing head in my preferred construction being evenly distributed. In my modified construction of drawing press, open at both sides, the pressure is equalized when both sets of die members are effective and operating. i

In the drawing which forms a part of this specification,

Figure l is a view in elevation, partly broken at one end, showing my improved press. y

Fig. 2 is a vertical section on the line 2-2, Fig. 1, showin the construction and arrangement of t e parts. y

Fig. 3 is a vertical sectional View showing a modification of the invention, but preserving the desirable feature of the openside press and the parallel plural eccentric Alnotion for actuating the reciprocating cross ead.

In the drawing, the base of the press is indicated by the letter A. This base will be placed in a suitable pit with the top thereof at or near the floor line. The bed B of the press is mounted onthe base, as indicated. Parallel eccentric shafts C are journaled in the base at each side of the longitudinal center line of the press, eagh of such eccentric shafts carrying gears op, the gears on one shaft intermeshing with the gears on the other, so that the said eccentric shafts -are rotated synchronously in opposite directions. A lay shaft c1 journaled at one side of the base, is provided with pinions c2' which engage the gears on one of the eccentric shafts, and thus transmit a movement of rotation to the eccentric shafts.

Straining rods D, arranged in spaced parallel rows, are guided in vertical openings formed in the bed of the press, each row comprising a plurality of rods. A reciprocatingpunch carrying cross head E is attached to the upper ends of the straining rods. The lower ends of the oppositel rods in the two rows are connected by means of a cross head F, in such manner that the cross heads E and F and the straining rods comprise a frame movable as a whole and guided in its vertical reciprocations by the openings in the bed of the press, and in which the said straining rods have their bearings. Each gear o is flanked by an eccentric c3, and eccentric links 04 connect the eccentrics c with the lower cross heads F at the pivotal points 05.

The arrangement of gears, eccentrics, straining rods and connections to the head E, will be duplicated in the number necessary to properly equip a press of predetermined dimensions, so that such press will embody a structure possessing the requisite degree of resistance and strength, to enable it to withstand the strains to which it is subjected while in operation.

Viewing Fig. 2, it willbe observed that the straining rods arranged inparallel rows are spaced so that the pressure of the drawing head E, generated in the operation of the eccentrics, is divided equally between the two rows of straining rods, and that the said head E has a parallel motion with an even distribution of the pressure over its lower or acting surface. In View of the parallel motion possessed by the head E, it is -not material to the successful operation of the press,

that the die members mounted upon the bed and upon the coperating head bearranged with any regard to the equalization of the pressure exerted by them. The jointly operating eccentrics, in the construction illustrated, act with a direct pull upon the head E, in which movement the tension is equally distributed through the straining rods of both rows. The result of this equalized movement is to relieve the straining rods from the side thrust and from the increased frictional contact to which they have been subjected in the older types of drawing presses, in which the drawing head was actuated from the eccentrics on a single shaft.

W'ith the above described arrangement of the rows of straining rods, there is reserved upon the bed of the press at the outside of each row a space on which may be placed a matrix or other die member, with a corresponding space upon the cooperating face of the drawinoI head, for the complemental die member. This construction enables me to produce a drawing press which is open at both sides, and to realize the benefits which flow from the use of open side presses, in that the feeding of blanks to the press and the withdrawal of the drawn flanged bars therefrom may be performed with greater facility. As a consequence of this construction and arrangement, the output of the press is materially increased over the possible production of older forms of presses in which the time-consuming feeding andwithdrawing operations were performed at the ends of the press. Asstated at the commencement of this specification, it .is my purpose to utilize the side feeding features of my improved press in the production of flanged bars and other parts of smaller dimensions. A gang of pressmenwill work at each side of thepress, and in view of the facility with which the operations of feed` ing and positioning the blanks and withdrawing-the flanged bars from the press will be performed, the press will be constantly operated.

The press is also constructed with provisions for turning out work of aheavier class, and also bars having a length exceeding that of the press, and in 'which a second operation is necessary to the completion of the bar. I achieve this by, arranging a set of die members forv the bed B and head E, in the space defined by the straining rods. In this arrangement the blanks will be fed from one end of the press and removed from the other, upon the completion of the drawing operation. Unless automatic means be provided for so feeding the blanks and removing the bars, it will be necessary to operate the press intermittingly at such times.

Fig. 3 shows a modified construction of press in which the very desirable feature of the open side press is preserved, and in` which a parallel motion is imparted to the drawing head by means of parallel eccentric shafts as before described. However in this construction, a single row of, straining rods D1 is employed to connect the drawing head E1 with the cross head F1, which latter is actuated by a direct thrust of the jointly operating eccentrics, instead of the draft of theeccentrics as in Fig. 2". lIn this constructiam'v the head El bea-rs with an-:Lf

equalized atddistributed pressure, and the straining rods are likewise relieved of the increased frictional engagement with their bearings in the bed, resulting from the angular thrust of 'the eccentrics carried by the single shaft of the presses of the older type. p

A very desirable result of the arrangement of the principal operating elements of the press below the floor line, is t at which permits the operatingrechanism o be eifif ciently lubricated by a constant shower or:

spray of oil. The oil dripping from the -mechanism may be collected and filtered for [being embodied in a drawing press, it will be understood that the invention is not to be limited to the use stated, but that. the

press may be equipped with suitable dies which will punch contoured blanks from sheet metal plates, as well as for the production of other articles.

Having thus described my invention,"

what I claim and desire to secure by Letters Patent of the United States, is:

l. In a-drawing press, a bed and a reciprocating head upon which the complemental die membersof the press are mounted. i'n a plurality of sets, actuating means for imparting a parallel motion to said members with respect to each other, and straining lrods dividing the area Aof the bed and head into Lspaces for the reception of the die members of each set.

2. In a drawing press, a bed and a reciprocatingv head upon which the complemental die members of the press are mounted in av plurality of sets, parallel eccentric shafts and connections therefromlto the head to impart a parallel motion thereto, and straining rods embraced in such connecl tions and dividing the area of the bed and head into a plurality of spaces for the reception of the die members of each set.

3. In a drawing press, a bed and a recipro'cating head upon which the complemental die members of the press are mounted in a plurality of sets, arallel eccentric shafts and connections t erefrom to the head to impart a parallel motion thereto, and straining rods constituting a part of such connections and arranged in parallel rows to divide thearea of the bed and head into a plurality of spaces for the reception of the die members of each set.

4. In a drawing press, a bed and a reciprocating head upon which the complemental die members of the press are mounted in a plurality of sets; arallel eccentric shafts and. connections t erefrom to the head to impart a parallel motion thereto, and straining rods guided in the bed of the press and dividing the area ofthe bed and head into open spaces at each side of the press for the reception of the die members,

and render the die members accessible fromil both sides to facilitate feeding and withplemental members of a plurality of. sets of work shaping dies,l straining rods connected to the head and guided'in the bed and separating the die members of one set from those of another, and actuating mechanism for the head and connected thereto by the straining rods.

6. In a .drawing'press, -a bedl and a reciprocating head, straining rods attached to the head and guided in the bed to provide open spaces at each side of the press to facilitate feeding and withdrawal of the work at both sides of the press, and means for actuating the head through the straining rods.

7. In a drawing press, a bed` and a re-l ciprocating head, each supporting the complem'ental members of a plurality of sets of work shaping dies, parallel rows of straining rods connected to the head and guided in the bed whereby the area of theA bed and head is divided into a plurality of spaces for the reception of the die members of each set, the spaces at the outer sides of the rows of straining rods constituting openings which enable the pr'essto be fed from either side, and the interior space defined by the said rows of straining rods constituting anv opening through. which the Press may be fed from the end, and means or actuating the head through the straining rods.

8. A drawing press comprising a bed and a head supporting the complemental members of a plurality of sets of dies of the press, and straining rods by. which the head is guided, said straining rods dividing the area of the bed into a lunality'of 4spaces opening at both sides ol) the press for the reception of the die members and for side feeding purposes.

In testimony whereof, I have signed my i lOhio, this 18th day of GEORGE M. SMITH. Witnesses:

J. oN. sima, l C. B. ConRELL.

name at Canton, May, 1920.

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