US2359566A

US2359566A - Subpress

Info

Publication number: US2359566A
Authority: US
Inventors: Freeland H Leslie
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-01-25
Filing date: 1943-01-25
Publication date: 1944-10-03
Anticipated expiration: 1961-10-03

Description

SUB-PRESS Filed Jan. 25, 1943 F. H. LESLIE 5 Sheets-Sheet 1 INVENTOR.

5 Sheets-Sheet 2 SUB-PRESS Filed Jan. 25, 1943 F. H. LESLIE w Y 5. J ml M 8 3 E 7 m. a m. w r W m fi B. w I w l1! a 3 I H w w 4% w I 1m I! u m J :1 I II! ||||||||a||||||||.l|||| Oct. 3, 1944.

Oct. 3, 1944. LESLIE r 2,359,566

SUB-PRESS Filed Jan. 25; 1943 5 sheets-s e t s Oct.3, 1944. v F. H. LESLIE I 2,359,566

SUB-PRESS Filed Jan. 25,' 1943 5 Sheets-Sheet 5 IN V EN TOR.

fla /lam 65146, BY

$m aammhmm UNITED STATES PATENT OFFICE 26 Claims.

This invention relates to sub-presses and embodies improvements of the sub-presses disclosed in my co-pending application Serial No. 453,306

and in my issued Patent No. 2,293,254. The subpress which is the subject'of this application is particularly useful when mounted in a press brake.

A press brake is a tool designed forbending steel and gener alg spealiin'g may be characte r1zedas' device which applies power along a long, transverse, shallow ram against a similarly shallow bed. For performing light punching operations over a comparatively large area in conjunction with a press brake, applicant devised the sub-press shown in the co-pending application, Serial No. 453,306. By means of this sub-press the power of the press brake may be distributed over a comparatively deep punch plate, i. e., one extending forwardly and rearwardly of the ram for substantial distances, and the press brake may thereby perform operations heretofore generally performed by straight sided presses. In the co-pending application, the applicant made it clear that off-center forward or rearward loading of a punch plate sets up forces operating at right angles to the plane of a flexible plate used in this particular type of sub-press and these forces bend the flexible leaf in such a way as to misalign the punches and dies. To limit the effect of these misaligning forces, applicant provided a means for preventing these forces from expending their strength upon the flexible plate, namely, the

stops

52, 54, and H8 in Figure 7 of said application.

The present invention has for its principal object the substitution of improved means for controlling forces directed toward the spring leaf from points outside the planes of its surfaces. It has been found that the stops employed in the device shown in the co-pending application are undesirably noisy when struck, and further that within the limits permitted by the stops, repeated distortion of the flexible leaf substantially shortens its life.

Toward attaining this end this invention seeks so to control forces tending to bend the flexible Plate that these forces will be evenly distributed throughout that port on of the flexible member whi"h is permitted to bend. Expressed more specifically, the object of this invention is so to hold the flexible plate between the die shoe carrying b' S and the punch carrying upper leaf that regardless of the degree of bending of the flexible member, the latter will always bend into a segment of a cylinder, that is, in cross section, to the arc of a circle.

One of the features of this invention is the provision of a vertically disposed link connecting the back end of the base to the back end of the upper leaf, the link being pivotally attached to each of these members. All forces operating at right angles to the surfaces of the flexible member will be restrained by the link, acting either as a support or as a restraining member. The pivoting of the link to the two members permits the free end of the upper member to move vertically with respect to the lower member within limits set by the conjoint action of the flexible plate and the link.

Another object of this invention is to locate the aforesaid link in a manner commensurate with structural considerations, bearing in mind that the rise and fall of the punch plate end of the upper leaf will be a matter of approximately one inch which results in comparatively small bending of the flexible member.

One of the features of this invention is the positioning of the pivoted, vertical link with its axis in a line or plane passing through the mid-point of the bendabl portion of the flexible member parallel with the holding edges of the holding means.

Another object of this invention is to prevent misalignment of the flexible member or strain with respect to its holding means in view of the positioning of the link. A feature of this invention is the provision of a hole in the flexible member through which the link is passed, a construction employed in place of two separate flexible members, one oneach side of the link, in order to assure improved rigidity between the flexible member and the holding means.

Another object of this invention is so to design the means for holding the flexible plate that it can be readily replaced.

Another object of this invention relates to the mounting of the link. As is well known, where two shafts are joined with a single link perpendicular to the shafts with short bearing surfaces on each shaft, there is little inherent stability for maintaining the link in its perpendicular position. With both of the bearings long, the stability would be excellent but it is difficult and expensive to make the two long bearings exactly parallel. With one bearing long and the other short, misalignment in parallelism is not so important yet the perpendicular stability is good. The applicant employs a large bearing surface on one shaft and a small bearing surface on the other shaft in order to permit transverse movement of the leaf in which the upper shaft is mounted with respect to the base in which the lower shaft is mounted.

Applicant illustrates three embodiments of the invention in the drawings, wherein:

Figure 1 is a perspective view of applicants new and improved sub-press positioned in a press brake, only portions of which are shown:

Figure 2 is a side elevation of the first embodiment of applicants invention;

Figure 3 is a rear view partly in section of one end of applicants first embodiment of the sub-press;

Figure 4 is a side view of the back end of a second embodiment of applicants invention;

Figure 5 is a rear view partly in section;

Figure 6 is a perspective view illustrating the link positioned through a hole in the flexible member;

Figure 7 is a diagram illustrating certain principles controlling the positioning of the vertical link;

Figure 8 illustrates the face of a cam track plate used in the third embodiment of the invention; and

Figure 9 is a view taken on the line 9-9 of Figure 8.

The problem to be solved Preliminary to a presentation of this invention, refer to Figure 2 wherein the numeral l0 identifies the bed of a press brake, |2 the ram, M the upper substantially inflexible leaf and I6 the lower arm or base of one of applicants sub.- presses, I8 the punch holding member and the die holding member. The arms l4 and I6 are held in assembled relationship by means of a spring leaf 22, mounted as shown, While the raising of the leaf I4 and punch holder |8 in order to permit the insertion and withdrawal of the work such as 24, is effected by a slot and link arrangement generally identified by the numeral 26.

In the construction shown in Figure 2 a punch 28 is mounted forwardly of the ram l2 with no counterbalancing punch mounted at an equal distance behind the ram. The effect of this v mounting of the punch 28 is that when the ram |2 exerting a force identified by the arrow 38 causes the punch 28 to strike the work 24, an opposed force represented by the arrow 32 is set up at a point substantially in front of the ram, there being only a frictional surface engagement between a striking bar 34 mounted on the bottom of the ram l2 and an anvil 36 mounted across the top of the punch holder I8. (For this discussion, assume that the link 38 is not in use.) Under such circumstances, the force 38 uses the force 32 as a fulcrum and sets up a force 48 downwardly directed against the spring leaf 22. Because the spring leaf 22 is designed to bend under the influence of a force moving at right angles to the plane of its surfaces, it does bend and momentarily the punch 28 does not enter the work. The punch 28 will not enter the work until the spring leaf 22 has reached its elastic limit. In reaching that limit the spring leaf 22 will draw the punch 28 backwardly out of alignment with its associated die 42. All of this has been explained in the copending application Serial No. 453,306.

Theoretical considerations Before describing the link 38, certain theoretical considerations should be examined. By comparing Figure 2 to Figure 7, it will be noted the leaf 22 in its normal position is shown horizontally between the points a: and y. The flexible plate or member 22 is held to the base between a block 43 and a cap plate 44 and the flexible member is held to the substantially inflexible leaf M by a block 46 and a cap plate 48. The leaf 22 i a flat plate, see Figure 6.

Returning to Figure 7 alone, if one applies a force along the arrow 58 to the member 48, the member 22, assuming that its bending moment for any given area or portion thereof is exactly equal to the bending moment of an other like area or portion, will bend along the arc of a circle to form a segment of a cylinder wall. That portion 52 of the flexible member 22 between the block 46 and the cap plate 48 will of course remain flat and a projection of this portion 52 will always intersect a projection of the portion 54 of the flexible member 22 between the block 43 and the cap plate 44 at a point which if included in the radius of the circle of which the member 22 has become an arc will exactly bisect the arc. Thus, if the

members

46 and 48 are moved up to the dotted line position indicated by the numeral 56, the flexible member 22 will now be the are 58 of a circle. The position 56 is selected because the cord '68 intersecting the point y makes an angle a of 15 degrees with the plane of the portion 54 of the flexible member 22, which plane remains fixed because it is held to the base of the subpress. Under such circumstances, the tangent 62 to the are 58 at the point 11:, makes an angle b with the cord 60 of 15 degrees. Erecting at :r' a perpendicular or radius to the tangent 62 and a like perpendicular or radius to the associated tangent 6| at the point y, we find that the center of the are 58 is the point 64. Or approaching the problem from dimensions, if 22 is exactly four inches and the angle 11 is 15 degrees, complementary angle 0 is 75 degrees and likewise the other angle d is '75 degrees. The angle e, therefore, must be 30 degrees or of a circle. Inasmuch as the are 58 is four inches long, w find that the circumference of the circle is 48 inches. The radius of the circle, therefore, is 48 inches divided by 2 pi or 7.65 inches.

It is important to note that the mid-point of the bendable portion of the flexible member 22 is the point 66. When the

members

46 and 48 are in position 56, the tangent 62 intersects the tangent 6| at the point 68.

Assume now that the members 4648 are raised to dotted line position 10. The flexible member 22 is bent to the are 12 which, because the angle 1 is a 30-degree angle as is the angle 9, forms a portion of a perfect circle. The angles h and 2', therefore, are each 60 degrees as is the angle 7'. By multiplying the length of the are 12, namely 4 inches by 6, the circumference of the circle is found to be 24 inches and the radius to be 3.82 inches.

Similarly by moving the member 46-48 to dotted line position 14, the flexible member 22 now describes the are 16. The point at is now in position :c'. It will be noted that the tangent 18 to the are 12 at :c" intersects the tangent 6| at and the tangent 82 intersects the tangent 6| at 84.

Attention is now called to the movement of the point x, or better the inside edge of the portion 52 (see Figure 6). The point a: on the flexiblemember 22 has pursued a path indicated by the dotted line 86. Moreover at all times the plane of the-portion 52 of the flexible member 22 has been tangent to the arc of the flexible member at the points x, 1:", etc. It is evident, therefore, that to preserve the life of the flexible member 22 by causing it to bend throughout all of its portions equally, it is necessary to move the point .1: along the dotted line 66 and at the same time to hold the portion 52 in a plane containing the tangent to the are at the point 3:.

There are various forces which tend to prevent the accomplishment of these two things. A force operating parallel to the horizontal plane of the normal position of the flexible member 22 either toward the point y or away from the point 1/ will not be able to displace the point :1: from the dotted path 86 because the weight or thickness of the flexible member 22 is chosen for the express purpose of being able to overcome any normal force which might be developed in these directions. Generally speaking, therefore, the point :1: will move along the track 86 unless the portion 52 is forced out of the plane containing the tangent to the arc of the flexible member 22 at the point a: and this brings us more specifically to the problem.

Referring for a moment to Figure 2, where the punch 28 is located forwardly of the ram I2 and the punch strikes the work 24, the force 40 is directed downwardly. Referring to Figure '7, when the force 40 is directed downwardly, the holding means 46-40 do not move upwardly so that the portion 52 can remain in a plane which is tangent to whatever arc the flexible member 22 would make at the point 1:. On the contrary. unless restrained, the members 46-48 will move into some such position as that shown by dotted line 86 wherein the point a:"" is closer to the point 1/ because the flexible member 22 has adopted a contour such as illustrated by the dotted line 90. If the force on the holding members 46--48 is directed upwardly as indicated by the arrow 50, which occurs when the press is offcenter loaded to the rear of the ram, the members 46-48 would have jumped into a position such as that illustrated by the dotted outline 92 and the flexible member 22 would have a configuration such as that indicated by the dotted line 94. It is quite apparent that the type of bending illustrated by the dotted

lines

90 and 94 will not only wear out the flexible member but draw the punches out of alignment with the dies. While these dotted

configurations

90 and 94 are exaggerated, distortions of the leaf will be suf- I flciently great to cause tearing of the work piece and wearing of the punch and die edges.

It is evident therefore, that the objective of applicant is to prevent movement of the point a: whether up or down, which is not consistent with the portion 52 of the flexible member containing the tangent to the arc of a circle at points x, x, etc. It should be noted that this refers to the arc of a circle. The portion 52 is tangent or nearly so to the dotted

configurations

90 or 94 but because of the position of the point x, the flexible member 22 cannot assume a curved relationship between the points a: and y.

In order to prevent unwanted vertical movement of the point x, applicant has positioned a link 38, referring now to Figure 2, vertically with a bearing at the lower end mounted on a shaft 96 journalled in a housing 98 rigidly fas tened to the base I6 and with a hearing at the upper end mounted on a shaft I00 journalled in a housing I02 rigidly fastened to the substantially inflexible leaf I4. The axes of the shaft 66 and I00 are positioned in a vertical plane I04 which bisects the bendable portion a:y of the flexible member 22. Moreover, the axes of the shafts 96 and I00 are equi-distant from the flexible member 22, a distance equal to the distance from mid-point 66 to either point a: or y.

Returning now to Figure '7, the link 36 is diagrammatically illustrated by the broken line I06. Because the link is rigid, the shaft I00 must move around the shaft 96 along the arc I06. The relationship of the holding

members

46 and 48 and the point a: to the shaft I00 is likewise rigid. Assuming for the moment that the link I06 is not connected to the point I00 and furthermore moving the holding

members

46 and 48 to the three positions 56, I0 and 14, so that the flexible member 22 will always bend along the arc of a circle, it is interesting to note that when a: is in position 0:, I00 will be in position I00; when a: is in position x", I00 will be in position I00; and when a: is in position x', I00 will be in position I00. When the link is coupled to the shaft I00, however, the shaft I00 cannot enter the position I00 but must stay on the path I08. In consequence of this, the

members

46 and 48 will be distorted slightly so that the portion 52 will not be a plane containing the tangent to the arc of a circle at the point :12. On the contrary, if the

members

46 and 48 are raised to a point such that the shaft I 00 occupies position IIO, while the point a: is at the point :r', the plane of the portion 52 will be along the line II2, which is to the right of the perfect direction for the plane of the portion 52 represented by the tangent 62. On the other hand, if the point H4 is distant above the mid-point 66 of the flexible portion of the flexible member 22 by the distance from the point :r' to the point II6, which is the point where an are I I0 of a circle having 1 as a center intersects the tangent 82, if an arc I20 has a radius equal to the distance II4 to I00, and if point I00 is moved to position I00 while moving at to position x, the plane of the portion 52 will be in a plane represented by the line I22. Finally, if the portion 52 is moved to position 56 so that the plane of portion 52 contains the tangent 62, the point I00 is at or approximately at the point I00. The point I00 appears to be on an arc I24 of a circle having a radius 66I00 with a center at 66.

From the foregoing paragraph we can draw the general conclusion that if the plane of the portion 52 at any given point on the line 66 makes a less angle with the cord, such as 60, than the fixed tangent 6| makes with the same cord, the bending of the flexible member will be shifted toward the right, that is toward the point y; and conversely, if the plane of the portion 52 makes a greater angle with the cord 60 than does the fixed tangent 6I to the cord 60, the bending of the flexible member will be shifted to the left. In either event, the bending of the flexible member around an arc of a circle or to a cylinder segment is not attained.

The third embodiment of the invention The third embodiment of this invention exactly attains the ends sought in the foregoing theoretical discussion. Cam tracks having the curvature of the tracks 86 and 81 shown in Figure 7 are mounted on the inside wall of the press brake or optionally of an extension of the base of the sub-press. Referring to Figures 8 and 9, the numeral I30 identifies one side wall of the press brake, see Figure 1, the view in Figure 9 being taken from the rear of the device. A plate I32 carries two cam tracks I34 and I36. The cam track I34 has its central axis I38 drawn to the configuration of the dotted line 86 shown in Figure 7. The point I40 in Figure 8 is the point :r in Figure 7, which is in the central plane of the flexible member which also contains the tops of the dies in the punching zone. The cam track I34 is not carried to the full length shown in Figure 7, that is to 32', because there is no occasion for raising the leaf very high. Similarly, the track I36 has its principal axis I42 following the line indicated by the numbers (see Figure 7) I, I00", and IIIIl. This track is likewise shortened. The point I44 corresponds to the point I00 in Figure 7.

It will be noted that both cam tracks I34 and I36 have counter-clockwise extensions I46 and I48. The purpose for this is to permit the substantially inflexible leaf to drop downwardly for a limited distance when the punches actually penetrate the dies. The plate I32, referring to Figure 9, is mounted on the wall I30 by any suitable means such as cap screws I48.

The means for causing the flexible leaf to maintain a proper relationship with respect to the holding means on the base consists of a pair of studs I50 and I52 which are mounted to one side of the rear lower end of the leaf I4, see Fi ure 9. The stud I50 is an integral extension of the block I02 while the stud I52 is an integral extension of the block 46. A cross section of the flexible member 22 is seen from the rear in Figure 9 while the cap plate 48 abuts against a downwardly extending portion of the block 46 and they are all held in assembled relationship to the block I02 by the cap screw I54. The leaf I4, only a portion of which appears in Figure 9, is held by any suitable means to the block I02.

Continuing to refer to Figures 8 and 9, it is evident that the leaf I4 can only be moved so as to cause the portion 52 of the flexible member to so point toward the tangent H, (see Figure '7) that the bendable portion of the flexible member 22 will always form a perfect circle. If an unusual vertical blow is struck upon the leaf I4, whether upwardly or downwardly, the shock will be taken up by the stud I50 operating in the track I36. These are the blows that applicant is specifically guarding against. Forces running parallel or nearly parallel to the plane of the flexible members normal position will be received by the stud I52 operating on the cam track I34. Forces from any other direction will be resisted by the conjoint action of the two studs and their respective tracks.

The second embodiment of the invention The second and third embodiments of applicant's broad invention represent commercial developments. Referring for a moment to Figure '7, the three positions of the point a: at x, 2:" and m' are purposely used in order to illustrate sharp angles of the

movable holding members

46 and 48 with respect to the tangent 6I in order to illustrate graphically the principles involved in the designing of applicants sub-press. As a matter of practice, referring to Figure 2, the punch plate holder will be raised just sufficiently to permit the punches to recede from the tops of the dies by approximately one inch. All that is wanted is sufilcient room to permit ready insertion or withdrawal of the work 24. Because the leaf I4 is comparatively long, the angle of the plane of the portion 52 (see Figure 7) to the tangent 8|, either at its mid-point or at the point y, is very small-three degrees or less. It will be noticed, again referring to Figure '7, that in raising the holding

members

46 and 48 to the position 56, the point 68 at which the tangent 62 intercepts the tangent 6|, is only a short distance to the left of the point 66 which is the mid-point of the bendable portion of the flexible member 22 when in normal position. Moreover, it should be noted that the arcs I08, I20 and I24 are almost congruent between the points I00 and I58. It follows, therefore, that if the point I00 can be substantially carried along the common are between the points I00 and I58 while the holding

members

46 and 48 are raised or lowered for a comparatively short distance, for all practical purposes, applicant will have attained his object.

This can readily be done by employing a vertical link, which is easy to make and inexpensive to mount, readily replaceable and capable of withstanding a great deal of abuse and hard usage.

Referring to Figures 4 and 5, the base I6 by means of a plurality of blocks I62, I64 and I66 and suitable nuts, bolts and dowels, rigidly holds the flexible member 22 and a yoke member I68. The forward end of the yoke I68 is supported by a column I10 and is held rigidly to the base I6. Straddling the yoke member I68 and suspended from the leaf I4 are a pair of arms I12 an IN to the bottom of which is rigidly fastened by means of a plate I16 and appropriate cap screws I18 the forward end of the flexible leaf 22.

Journalled in the yoke member I68 is a shaft I having its axis equi-distant from the points a: or y and likewise having its axis at a point distant from the mid-point 66 of the flexible portion of the flexible member 22 by a distance equal to the distance of a: or y from the point 66. On each side of the yoke I68 there is mounted on the shaft I88 a link, the two bearing numerals I82 and I84. The links I82 and I84 at their upper ends are pivotally mounted on a shaft I86 which is mounted by any suitable means in a web portion I88 of a T-member I90 rigidly fastened to the leaf I4. The I beams I92 and I94 provide mounting means for similar laterally spaced flexible member assemblages for holding a single wide, transverse punch plate all as may be seen in Figure 1 and they also may provide means for assembling the sub-press with a press brake or other means for moving the punch plate holder with respect to the die shoe holder.

Comparing Figure 4 to the diagrammatic Figure '7, the axis of the shaft I86 is in the same position as point I96 in Figure '7 and the axis of the shaft I80 is in the same position as the point I00. The arc I98 is circular and I00 is its center while the are 200 is likewise circular and has 66 as its center. The point 202 is the position which the point I96 should occupy when the point a: as interpolated into Figure 4 is at point :r in Figure '7 and similarly the point 204 is the spot that I96 should occupy when x is at the point 1:".

It would appear that almost perfect attainment of applicants objective could be obtained by utilizing a link such as that shown in Figure 4 having its center at 66. Structural difiiculties, however, present themselves. It is desirable to locate the link centrally of the flexible member when the latter is viewed from the rear in order to obtain proper balance. In the first embodiment of this invention, applicant illustrates the positioning of a link through a slot in the flexible member, the pivot points being above and below the flexible member. Actually pivoting the lower end of the link on a shaft having its axis in the plane of the flexible member might result in much broadened flexible members. Moreover, as can be seen in Figure 7, between the points I98 and 208, the arcs are practically congruent and inasmuch as the leaf I4 is raised for only small distances, indeed the shaft I86 will rarely pass the point 2I0 in Figure 7, it is evident that the more simple mounting of the lower end of the link at a point above the flexible member is practical.

The first embodiment of the invention The first and preferred embodiment of applicant's invention employs a link which is pivoted, referring to Figure '7, at 96 on the base and at I on the leaf so that the point I00 on the leaf must follow the circular arc I08.

Referring to Figures 2 and 3, mounted at the rear of the base I6 on

blocks

220, 226 and 43 is the rear end of the flexible member 22 held in position by the cap plate 44 and screws 222. Forwardly of the

blocks

220 and 226 is journalled a shaft 96. Centrally of the shaft 98 is mounted a link 38. The upper end of the link 38 is journalled on a shaft I00 which is mounted between two blocks I03 and I05 which are suitably fastened to the bottom of the leaf I4. The axes of the shafts 08 and I00 are equi-distant from the mid-point B6 of the bendable portion of the flexible member 22 and this distance is equal to the distance between the mid-point 66 and the points a: and y which are at the edge of the respective holding means 46-48 and 44-43. The

members

48 and 48 may together be considered as the leaf holding means and the

members

43 and 44 may jointly be considered as the base holding means, both with respect to flexible member 22.

Referring now to Figure '7, by raising the leaf I4 through a small arc, the shaft I00 of Figure 2 which occupies the same position as the point I00 will move slightly to the right, coming to a stop substantially short of the point I58. As has been demonstrated in Figure 7, this construction will hold the portion 52 between the leaf holding means 46 and 48 at a proper angle of inclination with respect to the flxed tangent GI. The link will absorb all vertical forces represented by the arrows 40 and 50.

This construction is simple. The blocks 220, 228, I03 and I05 may be identical as may be the

blocks

43 and 46 and

cap plates

44 and 48. This simplifies the drilling of holes for obtaining accurate assemblage of the device.

Attention is invited to the fact that the flexible member 22 is a single piece of material which has been slotted at 236 to pass the link. This is illustrated in Figure 6. In order to obtain proper functioning of the device, the edges :1: and y of the respective holding means 46--48 and 4443, must be very accurately aligned and if the flexible member 22 were composed of two pieces spaced from each other so as to permit the positioning of the vertical link 38 therebetween, these problems of alignment would be doubled. A single flexible member is employed, therefore. Moreover, a single plate having an opening centrally thereof for passing the link is much stronger than two separate plates spaced apart so as to pass the link.

The cap plate 44 is welded at 238 to the upper side of the flexible member 22 and the cap 48 is welded to the lower side of the flexible member 22 at 240. Holes for cap screws 222 and the dowels 242 may then be made and these can be positioned for both the block 43 and the block 46 on a jig. By that arrangement the entire flexible member with the

cap plates

48 and 44 may be removed or replaced when necessary. It is contemplated that from time to time the flexible member 22 will have to be replaced and this construction makes such replacement quite easy. The welding of the cap plate 44 to the top of the flexible member 22 and similarly of the plate 48 to the bottom of the flexible member 22, serves an additional important function. Where the flexible member 22 is simply positioned be tween the cap plate 44 and the block 43, the resistance to side thrust depends upon the side wall area of a dowel engaging the leaf 22. The flexible member 22 is quite thin. By applying the cap plate 44 to the top of the flexible member 22 by welding of the link, the compression strength of both the flexible member 22 and the cap plate 44 will resist side thrust on the dowel.

Another feature of this embodiment of the invention arises from applicant's employment of a long bearing on one of the link shafts and a short bearing on the other. Referring to Figure 3 a collar 244 is welded to the link as is the corresponding collar 225 on the other side. This provides the link with extended bearing support in its engagement with the shaft I00. At its lower end, however, the collar 245 is welded to the block 220 as is the collar 246 to the block 226. Forces operating in many directions are constantly occurring during the use of these sub .presses and it is important that the link not set up resistance as by binding between itself and the supporting shafts. If a transverse force tends to throw the punch plate holder I8 to the right, referring to Figure 3, and the die shoe holder 20 to the left, it is desirable that the link perform no resisting function but rather that it slide freely along the shafts. By employing a form of three point suspension between the shafts I00 and 96, this will be accomplished. Resistance to longitudinal transverse distortion is to be handled by the flexible leaves themselves.

Another feature of this invention is illustrated in Figure 1. It is sometimes desirable to move work from front to back straight through a press brake. Under constructions heretofore shown by the applicant, this has not been possible because the flexible member assemblages are in the way. In a five-foot press brake, the subpress may be four and one-half feet wide with a flexible member assemblage at each end and one in the middle. The flexible member assemblages, therefore, are positioned every two to three feet and if the press brake is 30 feet across, there may be 10 or 12 flexible member assemblages all extending forwardly by means of substantially inflexible leaves to a single 30-foot punch plate holder. In Figure 1, the center upper inflexible leaf I4 is not connected to the base, that is, there is no flexible member assemblage, Instead, it is connected by the I beam I92 to the upper inflexible leaves at both sides of the subpress. This construction necessitates a strengthening of the two end flexible member assemblages. The I beam I9: is suflicient to resist all dlstortional movements and to compel the central upper inflexible leaf to move in the same fashion as its associated leaves on each side. Work may now be advanced from the front of the press brake straight through the rear of the press brake provided the work is not wider than the distance between the inside edges of the two flexible member assemblages.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent is:

1. A sub-press comprising a base, a punching zone adjacent one portion of said base, a flexible member so disposed on said base outside said punching zone as to permit vertical movement of one side of said flexible member, a substantially rigid leaf mounted on the free end of said flexible member and having a portion thereof extending into the punching zone, and means for limiting the bending of the flexible member substantially to the arc of a circle when the portion of the substantially rigid leaf is moved toward or away from the base within the punching zone.

2. A sub-press comprising a pair of spaced members, a flexible member mounted on one side to one of the spaced members and on the other side to the other spaced member in such a way that the free sides of the spaced members may move toward or away from each other in a space defined as the punching zone, and means for limiting the bending of the flexible member substantially to cylindrical segments having various radii when the sides of the spaced members within the punching zone are moved toward or away from each other.

3. A sub-press comprising a, pair of substantially inflexible members assembled in spaced relationship to provide a punching zone therebetween for receiving on one of said members a plurality of dies, means joining the said substantially inflexible members for holding the same in said assembled relationship and for permitting movement of members toward and away from each other in the punching zone, and a link pivotally connected to both of said substantially inflexible members at points adjacent to said joining means for controlling approach or receding movements between those ends of the substantially inflexible members attached to the joining means.

4. A sub-press comprising a pair of substantially inflexible members assembled in spaced relationship to provide a punching zone therebetween for receiving on one of said members a plurality of dies having their cutting surfaces coincident with a plane extending lengthwise of the substantially inflexible members, means joining the said substantially inflexible members for holding the same in said assembled relationship and for permitting movement of the members toward and away from each other in the punching zone, said last named means being positioned approximately in said plane, and a link pivotally connected at one end to one inflexible member and at the other end to the other inflexible member at points adjacent to the joining means whereby approach or receding movements of those sides of the inflexible members attached to the joining means may be controlled.

5. A sub-press comprising a substantially inflexible member having aflixed to one end thereof a. complementary substantially inflexible member, said latter member being ofiset so that a substantial space is created between the free ends of said members whereby to receive a punch plate and die shoe, and said second substantially inflexible member having a flexing means adjacent the point of joinder of the two members, and a link pivotally connected at one end to one inflexible member and at the other end to the other inflexible m mber at points adjacent to the.

weakenedp0 wherefiy 'ipproacl'for receding movements of those sides of the inflexible members attached to the flexing means may be controlled.

6. A sub-press comprising a, base, a punching zone above a portion of said base, a flexible member mounted on said base outside the punching zone, a substantially inflexible member having one end attached to said flexible member and having its free end extending into the punching zone, means on the base adjacent the punching zone for supporting a die shoe, means on the free end of the substantially inflexible member for holding the punch holder, and a link pivotally connected at one end to the base and at the other end to the inflexible member at points adjacent to the flexible member whereby movement of the side of the inflexible member attached to the flexible member awa from or toward the base will be limited by the link.

7. A sub-press comprising a base, a punching zone along one side of said base, means on the base outside of the punching zone for holding one side of a flexible member having a free end directed toward the punching zone, a substantially rigid leaf mounted at one of its sides to said free end of the flexible member and having its opposite or free side extending into the punching zone, and means for limiting the bending of said flexible member substantially to the curve of a cylindrical segment when the free side of the leaf is moved toward or away from the base.

8. A sub-press comprising a base, a punching zone above one portion of the base. holding means mounted on the base outside the punching zone, a flexible member held along one side in said holding means and having its other or free side directed toward the punching zone, a substantially rigid leaf mounted at one end on the free side of the flexible member by holding means and having its other end extending into the punching zone, and a link pivoted to the rigid leaf and to the base so as to control the manner of bending of the flexible member.

9. A sub-press comprising a base, a punching zone above one portion of the base, holding means mounted on the base outside the punching zone, a flexible member held along one side in said holding means and having its other or free side directed toward the punching zone, a substantially rigid leaf mounted at one end on the free side of the flexible member by holding means and having its other end extending into the punching zone, and an upright link disposed adjacent to the flexible member and pivotally connected to the base at its lower end and pivotally connected to the rigid leaf at its upper end whereby bending forces operable on the flexible leaf will be legvenly distributed throughout the flexible mem- 10. A sub-press comprising a base, a punching zone above one portion of the base, holding means mounted on the base outside the punching zone, a flexible member held along one side in said holding means and having its other or free side directed toward the punching zone, a substan tially rigid leaf mounted at one end on the free side of the flexible member by holding means and having its other or free side directed toward the punching zone, and an upright link disposed Sl'lhtlb (S1. ljPillol with its lower end pivotally mounted on an extension of the base above the flexible member and with its upper end pivotally mounted on a rigid extension of the substantially rigid leaf.

11. A sub-press comprising a base, a punching zone above one portion of the base, holding means mounted on the base outside the punching zone, a flexible member held along one side in said holding means and having its other or free side directed toward the punching zone, a substantially rigid leaf mounted at one end on the free side of the flexible member by holding means and having its other end extending into the punching zone, and an upright link disposed with its lower end pivotally mounted on an extension of the base above the plane of the flexible member and with its upper end pivotally mounted on a rigid extension of the rigid leaf.

12. A sub-press comprising a base, a punching zone above one portion of the base, holding means mounted on the base outside the punching zone, a flexible member held along one side in said holding means and having its other or free side directed toward the punching zone, a substantially rigid leaf mounted at one end on the free side of the flexible member by holding means and having its other end extending into the punching zone, and an upright link having its lower end pivotally connected to the base at a point below the plane of the flexible member and having its upper end pivotally connected to the rigid leaf at a point above the plane of the flexible member.

13. A sub-press comprising a base, a punching zone above one portion of the base, holding means mounted on the base outside the punching zone, a flexible member held along one side in said holding means and having its other or free side directed toward the punching zone, a substantially rigid leaf mounted at one end on the free side of the flexible member by holding means and having its other end extending into the punching zone, and an upright link disposed substantially in the plane that bisects the plane of the flexible member between the holding means fastening the flexible member to the base and the holding means fastening the flexible member to the rigid leaf, said link having its lower end pivoted to the base below the plane of the flexible member and its upper end pivoted at a point above the plane of the flexible member to the rigid leaf.

14. A sub-press comprising a base, a punching zone above one portion of the base, holding means mounted on the base outside the punching zone, a flexible member held along one side in said holding means and having its other or free side directed toward the punching zone, a substantially rigid leaf mounted at one end on the free side of the flexible member by holding means and having its other end extending into the punching zone, and an upright link disposed substantially in the plane that bisects the plane of the flexible member between the holding means fastening the flexible member to the base and the holding means fastening the flexible member to the rigid leaf, said link having its lower end pivoted to the base at a point below the plane of the flexible member at a distance substantially equal to one-half the distance between the holding members for the flexible member, and having its upper end pivotally mounted to an extension of the rigid leaf at a like distance from the flexible member.

15. A. sub-press comprising a base, a punching zone above one portion of the base, holding means mounted on the base outside the punching zone, a flexible member held along one side in said holding means and having its other or free side directed toward the punching zone, a substantially rigid leaf mounted at one end on the free side of the flexible member by holding means and having its other end extending into the punching zone, and an upright link positioned in a plane that bisects that portion of the flexible member between the means holding it to the base and to the rigid leaf, said link having its lower end pivotally mounted on an extension of the base above the plane of the flexible member and having its upper end pivotally mounted to the rigid leaf.

16. A sub-press comprising a base, a punching zone above one portion of said base, a holding means mounted on said base outside said punching zone, a flexible member mounted in said holding means with its free end extending toward the punching zone and with its held end approximately in the plane normally containing the top of dies positioned in the punching zone, a rigid leaf having one end mounted on the free end of the flexible member and the other end extending into the punching zone and means for limiting bending of the flexible member to form substantially segments of a cylinder.

17. A sub-press comprising a base, a punching zone above one portion of said base, a holding means mounted on said base outside said punching zone, a flexible member mounted in said holding means with its free end extending toward the punching zone and with its held end approximately in the plane normally containing the top 01 dies positioned in the punching zone, a rigid leaf having one end mounted on the free end of the flexible member and the other end extending into the punching zone, and an upright link disposed with its lower end pivotally mounted on an extension of the base above the plane of the flexible member and with its upper end pivotally mounted on a rigid extension of the rigid leaf,

18. A sub-press comprising a base, a punching zone above one portion of said base, a holding means mounted on said base outside said punching zone, a flexible member mounted in said holding means with its free end extending toward the punching zone and with its held end approximately in the plane normally containing the top of dies positioned in the punching zone, a rigid leaf having one end mounted on the free end of the flexible member and the other end extending into the punching zone, and an upright link having its lower end pivotally connected to the base at a point below the plane of the flexible member and having its upper end pivotally connected to the rigid leaf at a point above the plane of the flexible member.

19. A sub-press comprising a base, a punching zone above one portion of said base, a holding means mounted on said base outside said punching zone, a flexible member mounted in said holding means with its free end extending toward the punching zone and with its held end approximately in the plane normally containing the top of dies positioned in the punching zone, a rigid leaf having one end mounted by a second holding means on the free end of the flexible member and the other end extending into the punching zone, and an upright link disposed substantially in the plane that bisects the plane of the flexible member between the holding means fastening the flexible member to the base and the holding means fastening the flexible member to the rigid leaf, said link having its lower end pivoted to the base below the plane of the flexible member and its upper end pivoted at a point above the plane of the flexible member to the rigid leaf.

20. A sub-press comprising a base, a punching zone above one portion of said base, a holding means mounted on said base outside said punching zone, a flexible member mounted on said holding means with its free end extending toward the punching zone and with its held end approximately in the plane normally containing the top of dies positioned in the punching zone, a rigid leaf having one end mounted by a second holding means on the free end of the flexible member and the other end extending into the punching zone, and an upright link disposed substantially in the plane that bisects the plane of the flexible member between the holding means fastening the flexible member to the base and the holding means fastening the flexible member to the rigid leaf, said link having its lower end pivoted to the base at a point below the plane of the flexible member at a distance substantially equal to one-half the distance between the holding members for the flexible member, and having its upper end pivotally mounted to an extension of the rigid leaf at a lik distance from the flexible member.

21. A sub-press comprising a base, a punching zone above one portion of said base, a holding means mounted on said base outsid said punching zone, a flexible member mounted in said holding means with its free end extending toward the punching zone and with its held end approximately in the plane normally containing the top of dies positioned in the punching zone, a rigid leaf having one end mounted on the free end of the flexible member and the other end extending into the punchin zone and an upright link positioned in a plane that bisects that portion of the flexible member between the means holding it to the base and to the rigid leaf, said link having its lower end pivotally mounted on an extension of the base above the plane of the flexible member and having its upper end pivotally mounted to the rigid leaf.

22. A sub-press comprising a base, a punching zone adjacent a portion of said base, spaced holding members mounted on said base outside the punching zone, a flexible member mounted on each of said holding means and having a free side directed toward the punching zone, said flexible members being in transverse alignment, a rigid leaf mounted by one end to the free end of each flexible member and each having its other end extending into th punching zone, a rigid member connecting the rigid leaves to each other, a third leaf mounted on said rigid mem her having an end extending toward the punching zone, and a plate connecting the free ends of the rigid members.

23. A sub-press comprising a base, a punching zone above one portion of said base, a flexible member assemblage mounted on said base outside said punching zone, said flexible member assemblage having a movable portion directed toward the punching zone, a leaf at one end mounted on the movable portion of the flexible member assemblage, the free end of said leaf extending into the punching zone, a second flexible member assemblage mounted on the base outside the punching zone, a second leaf mounted on the movable portion of the second flexible member assemblage, a punch plate holder connecting the free ends of the leaves in the punching zone, and a reinforcing leaf mounted on the punch plate holder between the first two rigid leaves having its free end directed to a point outside of the punching zone in alignment transversely with th flexible member assemblages, and a transverse support fastened to all of the rigid leaves at points adjacent to an upright plane passing through the flexible member assemblages, where- .by the punch plate holder will move within limits set by the flexible member assemblages,

24. A flexible member assemblage for holding in assembled relationship a rigid leaf carrying a punch plate holder and a base carrying a die shoe holder comprising a substantially flat flexible member, a cap plate integrally mounted along one side of said flexible member and a second cap plate spaced from the flrst cap plate and integrally fastened to the under side of the flexible member substantially parallel to the first cap plate, whereby there is established a free bendable portion between the two cap plates.

25, A sub-press comprising a base, a punching zone above one portion of the base, mounted outside the punching zone on the base a flexible member having a side directed toward the punching zone and movable with respect to the base, a rigid leaf mounted on the free side of the flexible member, an opening through the flexible member, and an upright link disposed through said opening and pivotally connected at one end to the rigid leaf and at the other end to the base.

26. A flexible member assemblage for holding in assembled relationship a rigid leaf carrying a punch plate holder and a base carrying a die shoe holder comprising a rectangular flexible plate, a cap plate integrally fastened to one flat surface of said flexible member along one side, a similar cap plate rigidly fastened to the opposite flat surface of the flexible member along an opposite side whereby a free bendable portion between the two cap plates is established, and an opening disposed centrally of said bendable portion whereby when one cap plate is mounted on the base and the other cap plate is mounted on the leaf, a link may be positioned through the opening and pivotally connected at one end to the leaf and at the other end to the base.

FREELAND H. LESLIE.

// CERTIFICATE OF CORRECTION- Patent No. 2,359,566. October 5, 19141;.

FREELAND H. LESLIE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 6, second column, line 6, claim 5, for "weakened portion" read "flexing means--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office Signed and sealed this 21pm day of April, A. D. 1915.

Leslie Frazer S eal) Acting Commissioner of Patents.