US2438319A - Bending brake - Google Patents

Description

March 23, 1948. P. KILHAM I 2,438,319 4 BENDING BRAKE 7 Original .Filed July 15, 1942 5 Sheets-Sheet 1 fete? fzz'Zkam Zy M M fiwfenzar March 23, 1948. P. KILHAM BENDING BRAKE Original Filed July 15, 1942 5 Sheets-Sheet 2 r M A E gave A? m: no.

March 23, 1948. RKILHAM 2,438,319

' BENDING BRAKE Ofiginl Fil ed July 15, 1942 5 Sheets-Sheet a Zy/ZAMM Jifarzeqgas March 23, 1948. P. KILHAM 7 2,438,319

BENDING BRAKE Original Fiied July 15, 1942 5 Sheets-Sheet 4 F2946 JO 1 ME%' W g.M M

March 23, 1948. -P. KILHAM I zBENDING TBRAKE Original Filed July 15, 1942 5 Sheets-Sheet 5 Patented Mar. 23, 1948 UNITED STATES PATENT OFFICE BENDING BRAKE Peter Kilham, Attleboro, Mass.

22 Claims.

My invention relates to an improvement in brakes for bending sheet metals and the like.

One purpose is the provision of an adaptable brake which may be readily adjusted for the bending of relatively small pieces of various size and shape, especially those such as tempered aluminum, requiring a radius bend.

Another purpose is the provision of an adaptable hand operated brake which may be operated by a single operator.

Another purpose is the provision of an improved means for directing the pressure against the work.

Other purposes will appear from time to time in the course of the specification and claims.

This application is a continuation of my application for Bending brake, Serial Number 451,- 001 filed July 15, 1942 and subsequently abandoned.

I illustrate my invention more or less diagrammatically in the accompanying drawings wherein:

Figure 1 is a perspective;

Figure 2 is a section on an enlarged scale on the line 2-2 of Figure 1;

Figure 3 is a plan view;

Figure 4 is a section on the line 4-4 of Figure 1;

Figure 5 is a section on the line 5-5 of Figure 2; r

Figure 6 is a section on the line 6-6 of Figure 3;

Figure 7 is a partial view similar to Figure 6, with the parts in a different position;

Figure 3 is a section on the line 88 of Figure 3;

Figure 9 is a perspective illustrating a different adjustment;

Figure 10 is a section onthe line Ill-40 of Figure 9; and

Figure 11 is a partial perspective of a further different adjustment.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings, I generally indicates any suitable base, upstanding from which extends the support'Z. At the upper end of the support is mounted any suitable top plate 3, having downwardly extending side flanges 4, formed, as shown in Figure 8, by angle members. It will be understood that the portion 3, 4 may be made in a single piece if desired. 5 illustrates a top plate, or a pair of top plates, separated by a channel 6. It will be understood that this also I may, if desired, be made integral with the member 3, 4. I

Received in the channel 6 is a guide strip 1, which carries at its forward end a stop bar 8, which is adapted to rest flush against the top of the plates 5 and slide forwardly and backwardly therealong, guided by the member ,1. Mounted on the top of the stop bar 8 is an adjusting bar 9, to which additional stop members ll may be secured, as by insertion between the members 8 and 9 and tightening up of the screws [0.

It will be understood that the bar itself may be employed as a stop member, or that these additional stop members ll may be inserted. They may be formed for example of sheet metal, with a downwardly bent forward edge l2, as indicated in Figure 2. A plurality of them may be simultaneously employed, and their forward extension may be simultaneously varied, so that a piece having a number of bends may be gauged and bent at a number of stations without delaying the work to make stop adjustments, and so that a piece with an irregular contour can be accommodated.

in order to clamp the gauge structure, I provide a clamping block I4, which is held for example by a bolt IE to one of the members 5, and extends across the bar or guide piece I. It will be noted that the top of the bar I is slightly higher than the top of the members 5. Thus, when the looking or clamping bar 14 is moved down, it performs a clamping function. It may be controlled by any suitable hand screw It.

In order to clamp the Work on the brake, I provide a clamp structure including the frame element generally indicated as A, having a rear bar or element 20 and forwardly extending converging elements or bars 2 l, which converge centrally and forwardly, as at 22, and terminate in a head 23, herein shown as welded thereto, and having an upwardly and outwardly extending flange 24, and a downwardly inclined plane forward face 25.

It will be understood that any suitable bending or gripping element 26 may be screwed or bolted to the head 23, as shown for example in Figures 6 and 7. Iillustrate for example a pair of bolts 21. It will be understood that a wide variety of shape and size of plates may be employed. I illustrate for example in Figure 1 a plate 26a having laterally extending relatively thin arms 2612. In Figure 11, I illustrate a much narrower plate 260 having no such arms. It will be realized that the bending plate may be varied to suit the work. Where a relatively narrow piece is to be bent, or a piece having side flanges, as shown in Figurell, the narrow blade is employed. Where it is desired to grip a wide piece, as in Figure 1, a wide blade is mounted. Special blades will be useful in making short square tubes and other special shapes. Also, the forward edge of the blade, around which the piece is bent, may be rounded, thus giving a radius bend, which is required in certain materials, notably tempered aluminum, which are too brittle to be bent sharply.

The structure thus formed is pivoted vat'the rear edge as follows: Sockets 3!) (see Fig. 3) re ceive pins 3| on the blocks 32, having outwardly extending relatively narrow portions 33(see Fig. 2) conforming to generally horizontal slots 34 in the upwardly extending brackets 35, which are secured to the side of the brake, for example by bolts or screws 35. It will be understood that if desired, the pins 3i and the bore 35 may be made continuous, so that the pressure frame or blade carrying support is pivoted upon a continuous rod extending through the device.

31 is a manually controlled screw for varying the position of the blocks against the compression of the springs 38. It is thus apparent that the forward edge of the gripping member or plate 26 can be adjusted toward or away from the front edge of the working plate, depending, for example, on the thickness of the metal to be bent.

39 is any suitable tool or spare part compartment which may for convenience be mounted at the rear of the brake.

In order to urge the brake or clamp into material gripping position, I provide the following structure: 55 (see Fig. 8) indicates a bracket depending from one of the flanges 3, having a horizontal offset portion 4i, apertured to receive a screw 42, which is unitary with a generally vertical'supporting bar 43, to the upper end of which, as at 44, is pivoted the pressure bar 35, which extends transversely and generally horizontally across the top of the device.

46 is a spring which normally thrusts the bar 49 is any suitable retaining means for maintaining the vertical alignment of the bar 43 and forms part of an adjustment which will later be described.

As shown for example in Figure 8, it will be observed that the pressure bar 45 is connected by a spring 50 with a forward portion of one of the clamp arms 2|. The clamp arms 2| are also connected adjacent their forward ends by a species of upwardly arched bridge 5!, the upper portion of which serves as a contact between the clamp structure and the pressure bar d5. It will be observed that a rocking contact is provided at 5|, during relative movement of the parts, and that the area of contact as shown in Figure 8, is relatively small, is remote from'the axis of the clamping structure as a whole, and is aligned with the center of the top of the brake.

The opposite end of the bar 45 has pivoted thereto, as at 52, a pair of links '53, which in turn are pivoted, as at 54, to a lever 55, the outer end of which terminates in an operating knob 56, and the inner end of which is pivoted, as at 51, to the bracket 58, secured to the side of the brake. The dottedline position in Figure 8 illustrates the release position, and the full line the pressure applying position. It will be observed that in of which .is controlled by a lock nut 92.

the locking position the center 54 passes beyond dead center 'in relation to the centers 52 and 51, and the device thus is kept locked, independent of the maintenance of pressure on the lever 55. In other words, the device is self-locking when it passes beyond dead center.

Extending downwardly from the lever 55 is a pair of links 85, pivoted to the lever 55, as at St, and pivoted, as at 52, to a vertically guided bar 63, which terminates in a species of stirrup 64, having a bottom transverse element 65. V65 is a treadle. pivoted as at 5?, to the base i at a point intermediate the ends of the treadle. The forward end of the treadle terminates in a heel-engaging element 68. The rear end of the treadle provided-with a loop 65 (see Fig. 4), or any other suitable means for engaging the cross piece 65 of the stirrup 64. It will be understood,-therefore, that when the user presses down with the toe of his foot on the left part of the treadle 65, referring to the position of parts shown in Figure 4, the bar 63, and thus the lever 55, is moved towards locking position. "On the other hand, if the position, without additional lifting movement by the foot of the user. Thetension of the spring I! maybe raised by means of the eyebolt lla.

mounted in a bracket 'Hb on the support 2, and an adjusting nut i la.

There is a rolling or free connection between the outer end of the lever ill and the links 55 obtained by a cross pin 72, seated in a bent depressed portion 73 at the'end of the lever 75. Any suitable guides may be employed for thebar 63. I illustrate for example a pair of brackets M, 75, and a vertical guide piece 16 secured thereto.

Assuming that the properly gauged sheet of metal to be bent is gripped between the member 26 and the forward edge of the members 5, the

actual bend is applied by the lift blade 80. 'The lift blade is secured by any suitable screws st to an adjusting and supporting plate 82?,illustrated for example in Figure .9, which shows the lift bladeremoved. Formed for convenience unitarily with the plate 82 are end elements 83, which extend upwardly to form hubs or bearing members 84, within which are any suitable bearings, herein shown .as anti-friction bearing means 35 (see Fig.5), the inner race of which surrounds a pin .56, which: is fixed .in a bracket fikwhich is adjustable about a horizontal axis defined for example by the screw 88. As shown iniFigu're 2, the bracket has an elongated aperture -89, through which passes the adjusting screw 95, and an upper portion of the bracket is engaged by a set screw 5|, the position tion to the forward edge of the structure. With the parts as adjusted in Figure 2, the center of rotation of the lift blade is located slightly above Each . and slightly forwardly of the edge of the work receiving top of the brake. I

The lift blade 80 may be slightly vertically adjusted on the support 82, the screws 8| passin through slight slots 8 I a in the blade 80. The final adjustment is made for example by the set screw 95, shown in Figure 2 with its lock nut 96, the screw passing through the projection 91 extending outwardly from the side element 83 of the member 82.

As shown in Figure 9, the lift blade 80 has been removed, and a substitute lift element or bending tool 98 has been positioned, being held by an upper guiding block 99 secured thereto, and engaging the top of the bar 82, and a locking screw I09 (see Fig. 10) passing through one of the horizontal adjusting slots II] I, of which for convenience two are shown. It will be understood that a plurality of tools 98 may be applied at the same time. They may be applied for bending small portions or for bending parts of large pieces where ears are bent, or for bending a center portion of a piece only.

The lift structure is manually actuated by the handle I53, the ends of the handle being secured in any suitable fashion to the bar 82. The user simply lifts forwardly and upwardly on the member I33 and bends the work. The upward limit of the bending movement is controlled by the limit rod IM, which is pivoted as at I65 to ears extending outwardly from the rear face of the bar 82. It slides through a pivoted block I06, pivoted on the downwardly extending bracket or yoke I01, connected to the front of the brake base. An adjustable limit element I58 may be held at any desired adjustment on rod I04, for example by the screw I59, thus limiting the upper bending movement of the lift 98.

It will be realized that whereas I have described and illustrated a practical and operative device, nevertheless many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention.

I therefore wish my drawings and description to be taken as in a broad sense illustrative or diagrammatic, rather than as a limitation to my precise showing.

The use and operation of my invention are as follows:

I provide a small, light, adaptable, and yet powerful bending brake which is adapted for one man operation and which can be quickly reset to take pieces of a substantial variety of sizes and shapes and angular requirement. In the first place, I provide what is in effect a three-point contact for the braking frame, centering the downward thrust at the forward end of a triangle formed by the members 2i] and 2|, which entirely avoids the customarily employed means of separate application of force at the opposite ends of a brake blade. The actual thrust is delivered centrally to the above mentioned triangle by the contact between the transverse clamp bar 45 and the convex top of the bridge 5!. I provide a series of adjustments which permit my device to be adapted for use with varying gauges of material and material of varying resistance to bending.

Thus, the pivot is of the bar 45 can be upwardly adjusted, the frame 29, '2I can be longitudinally and horizontally adjusted, the pivot point of the lift blade is adjustable by rotation of the bar 81 about the center 88, the lift blade 80 is vertically adjustable on its support, the lifting movement is adjustable by controlling the position of the stop I08, thus varying or adjusting the angle of the bend.

-on the working surface.

The material is readily and adjustably gauged by moving the gauge bar 8 backward or forward I find it highly advantageous to associate with the gauge bar 8 additional gauges II, which may be used in a wide variety of sizes, shapes and numbers, and which can be themselves adjusted forwardly and rearwardly in relation to the bar 8, and can have their forward faces either-parallel with or not parallel with the front face of the gauge bar 8. Thus, parts of varying size and varying shape can be handled or parts with irregular rear edges can readily be gauged for bending, or parts with a number of bends can be bent at stations transversely across the working edge of the machine without delaying work for adjustment.

The clamp blade proper 26 can be removed and adjusted and widely varied in form, as seen for example by a comparison between ,Figures 1 and 11. The lift blade can not only be adjusted but can be entirely removed and replaced by other individual lift elements, which may be used singly or multiply, and can [be longitudinally adjusted along the bar 82, as shown in Figure 9.

In using the device the operator can employ the ball 55 as a handle for manual operation, or he can to a substantial degree employ foot operation by employing the treadle 66.

The clamping mechanism may be actuated to move the center 54 beyond dead center in relation to the centers 52 and 51, which can be doneeither by hand or by foot pressure. Or the user can maintain a constant foot pressure and not move the center 54 beyond dead center. In that case, a light upward movement of the foot is sufficient to release the work. Thus, I provide a highly flexible structure, which can handle with great ease and speed a maximum of different forms of parts to be bent, and can make a radius bend such as is required in tempered aluminum.

I claim:

1. In a bending and forming brake, a stationary bed, clamping means mounted above said bed for clamping the work downwardly thereagainst, and a bending element pivoted adjacent the forward edge of the bed, and means for adjusting the axis of rotation of said bending element in relation to the forward upper edge of the bed, including a pair of arms located adjustably one at each side of a front portion of the bed, a pivotal connection between each said arm and. the bending element, and means for adjusting each said arm in relation to said bed.

i 2. In a bending and forming brake, a stationary bed, clamping means mounted above said bed for clamping the work downwardly thereagainst, and a bending element pivoted adjacent the forward edge of the bed, and means for adjusting the axis of rotation of said bending element in relation to the forward upper edge of the bed, including a pair of arms located adjustably one at each side of a front portion of the bed, a pivotal connection between each said arm and the bending element, and means for adjusting each said arm in relation to said bed, including bolt and slot connections between each said arm and the bed.

3. In a bending and forming brake, a stationary bed, a generally triangular clamp, the base of the clamp being pivoted adjacent the rear ofthe bed, the apex of the clamp extending adjacent the front of the bed, a, bending blade structure secured adjacent the apex of said clamp and located adjacent the forward edge of the bed, and means for exerting a clamping thrust 4. In a bending and forming brakala stationary bed, a generally triangular clamp, the base of the clamp being pivoted adjacent the rear of the bed, the apex. of the clamp extending adjacent the front of thebed,v abending blade structure secured adjacent the apex of said clamp and located adjacent the forward edge of the bed,and means for exertinga clamping thrust againstv said calmpadjacent its apex including a pressure bar extending transversely across the clamp, means for locking the pressure bar in clamping. postion and a contact element interposedbetween the clamp and the pressure bar.

5. In a bending and forming brake; a stationary bed, a generally triangular clamp, the base of the clamp being pivoted adjacent the rear of thebed, the apex of the clamp extending adjacent the front of the bed, a bending blade structure secured adjacent the apex of said clamp and located adjacent the forward edge of the bed,- and means for exerting a clamping thrust against said clamp adjacent its ajex including a pressure bar extending transversely across the clamp, means for locking the pressure bar in clamping position and a contact element interposed between the clamp and the pressure bar, the area. of contact between said contact element and. the: pressure bar being located on a line perpendicular to the pivotal connection be 7 tween the base cent the forward edge of the bed, means, for

clamping the work downwardly against: the bed,

7 and means for applying downward compression against said clampingv means, including an abutment vertically adjustable at oneside of the bed, a clamping lever pivoted thereto and extending across the bed and above said clamping means, and means for depressing the opposite end of said clamping lever, including an actuating lever and a link pivoted to the free end of saidclamping lever, and pivoted at its other end to said: actuating lever, said actuating lever being pivotedin relation to the bed, the pivotal connection between the actuating lever and the bed being outside of a plane common to the axes of the pivotal connectionsbetween the link and the clamping lever and between. the link and the actuating lever, whereby when the: actuating lever is at the limit of its locking excursiomit is the clamping lever of the work.

'7. In a bending and forming brake, a station "ar horizontal bed having a free forward working edge, a clamp structure rotatabl-y mounted at its rear end in normally fixed relation to the bed and extending forwardly above the bed and adjacent said working edge, said clamp structure having at its forward end a blade receiving seat, means for securing a selected one of a plurality of clamp blades of different form 'to said seat, means for applying downward pressure against a forward portion of said clamp structure at an'area intermediate the sides of the bed, and overlying the bed, and for therebymov-ing the clamp blade about the axis of the, clamp structure, downwardly against thebed, and a bending blade rotatably mounted adjacent the forward edge of the bed and means 'forro'tating it upwardly against the work held by the clamp blade and} for 1 thereby upwardly bending the work. e

8, In a bending and forming brake, a stationary horizontal bed having a free forward working edge, a calmp structure rotatably mounted at its rear end in normally fixed relation to the bed and extending forwardly above the bed and adjacent said. working edge, said clamp structure lying the bed, and for thereby moving the clamp blade about the axis of the clamp structure, downwardly against the bed, and a bending blade rotatably mounted adjacent the forwardedge of the bed and means for rotating it upwardly.

against the work held by the clamp blade and for thereby upwardly bending the work, and means for adjusting the axis of rotation of said bending bladev in relation to the bed.

9. In a bending and. forming brake, a stationary horizontal bed having a free forward working edge, a clamp structure rotatably mounted at its rear end in normally fixed relation to the bed and extending forwardly above the bed and adjacent said working 'edge, said clamp. structure having at its forward. end a blade receiving seat, means for securing a selected one of a pluralityof clamp blades of different form to said seat, means for applying; downward pressure against a forward portion of said clamp structure atan area intermediate the sides of the bed,

and overlying the bed, at a limited area located 40 on a line perpendicular to the axis of rotation of the clamp'structure and for thereby moving the ing blade rotatably mounted adjacent the forward edge of. the bed and means for rotating it upwardly against the work held by the clamp blade and for thereby upwardly bending the clamp structure havingv at its forward end a blade receivingseat, means for securing a selected one'of a plurality of clamp blades of different form to said seat, means for applying downward pressure against a forward portion of said clamp structure at anlarea intermediate the sides of the bed, andoverlying the bed, at a limited area located on a line perpendicular to the. axis of rotation of the clamp structure and for thereby moving the'clamp blade aboutlthe axis of the clamp-structure, downwardly against the bed, and a bending blade rotatably mounted adjacent the forward edge of the bed and means tending clamplever, a link. connecting one end of said clamp lever with the bed, an operating '1 lever pivoted at the opposite side of the bed and a link connecting the opposite end of said clamn V lever to said operating lever intermediate the ends of said operating lever.

11. In a bending and forming brake, a stationary horizontal bed having a free forward working edge, a clamp structure rotatably mounted at its rear end in normally fixed relation to the bed and extending forwardly above the bed and adjacent said worln'ng edge, said clamp structure having at its forward end a blade receiving seat, means for securing a selected one of a plurality of clamp blades of different form to said seat, means for applying downward pressure against a forward portion of said clamp structure at an area intermediate the sides of the bed, and over lying the bed, at a limited area located on a line perpendicular to the axis of rotation of the clamp structure and for thereby moving the clamp blade about the axis of the clamp structure, downwardly against the bed, and a bending blade rotatably mounted adjacent the forward edge of the bed and means for rotating it upwardly against the work held by the clamp blade and for thereby upwardly bending the work, said means for applying downward pressure including a transversely extending clamp lever, a link connecting one end of said clamp lever with the bed, an operating lever pivoted at the opposite side of the bed, a link connecting the opposite end of said clamp lever to said operating lever in termediate the ends of said operating lever and a pedal associated with said brake and an actuating connection between said pedal and said operating lever.

12. In a bending and forming brake, a stationary horizontal bed having a free forward working edge, a clamp structure rotatably mounted at its rear end in normally fixed relation to the bed and extending forwardly above the bed and adjacent said working edge, said clamp structure having at its forward end a blade receiving seat, means for securing a selected one of a plurality of clamp blades of different form to said seat, means for applying downward pressure against a forward portion of said clamp structure at an area intermediate the sides of the bed, and overlying the bed and for thereby moving the clamp blade about the axis of the clamp structure downwardly against the bed, and a bending blade rotatably mounted adjacent the forward edge of the bed and means for rotating it upwardly against the work held by the clamp blade and for thereby upwardly bending the work, and means for adjusting the axis of rotation of said clamp structure in relation to said bed.

13. In a bending and forming brake, a stationary horizontal bed having a free forward working edge, a clamp structure rotatably mounted at its rear end in normally fixed relation to the bed and extending forwardly above the bed and adjacent said working edge, said clamp structure having at its forward end a blade receiving seat, means for securing a selected one of a plurality of clamp blades of different form to said seat, means for applying downward pressure against a forward portion of said clamp structure at an area intermediate the sides of the bed, and overlying the bed and for thereby moving the clamp blade about the axis of the clamp structure downwardly against the bed, and a bending blade rotatably mounted adjacent the forward edge of the bed and means for rotating it upwardly against the work held by the clamp blade and for thereby upwardly bending the work, and abutment means for the work, ad-

10 justable on said bed toward and away from said forward working edge.

14. In a bending and forming brake, a stationary horizontal bed having a free forward working edge, a clamp structure rotatably mounted at its rear end in normally fixed relation to the bed and extending forwardly above the bed and adjacent said working edge. said clamp structure having at its forward end a. blade receiving seat, means for securing a selected one of a plurality of clamp blades of different form to said seat, means for applying downward pressure against a forward portion of said. clamp structure at an area intermediate the sides of the bed, and overlying the bed and for thereby moving the clamp blade about the axis of the clamp structure downwardly against the bed, and a bending blade rotatably mounted adjacent the forward edge of the bed and means for rotating it upwardly against the work held by the clamp blade and for thereby upwardly bending the work, and means for adjusting the edge of said bending blade toward and away from its axis of rotation.

15. .In a bending and forming brake, a stationary horizontal bed having a free forward working edge, a clamp structure rotatably mounted at its rear end in normally fixed relation to the bed and extending. forwardly above the bed and adjacent said working edge, said clamp structure having at its forward end a blade receiving seat, means for securing a selected one of a plurality of clamp blades of different form to said seat, means for applying downward pressure against a forward portion of said clamp structure at an area intermediate the sidesof the bed, and overlying the bed and for thereby moving the clamp blade about the axis of the clamp structure downwardly against the bed, and abendingblade support rotatably mounted adjacent the forward edge of the bed, means for rotating it upwardly toward the work held by the clamp blade, and a bending blade adjustably mounted on said support.

16. In a bending and forming brake, a stationary horizontal bed having a free forward working edge, a clamp structure rotatably mounted at its rear end in normally fixed relation to the bed and extending forwardly above the bed and adjacent said working edge, said clamp structure having at its forward end a blade receiving seat, means for securing a selected oneof a plurality of clamp blades of different form to said seat, means for applying downward pressure against a forward portion of said clamp structure at an area intermediate the sides of the bed, and overlying the bed and for thereby moving the clamp blade about the axis of the clamp structure downwardly against the bed, and a bending blade support rotatably mounted adjacent the forward edge-of the bed, means for rotating it upwardly toward the work held by the clamp blade, and a bending blade adjustably mounted on said support and means for adjusting the axis of rotation of said bending blade support in relation to the bed.

17. In a bending and forming brake, a stationary bed having a free forward edge, said bed having a length of the order of its width, a generally triangular clamp, the base of the clamp being pivoted adjacent the rear of the bed, the apex of the clamp extending adjacent the front of the bed, a bending blade structure secured adjacent the apex of said clamp and located adjacent the forward edge of the bed, and means for exerting a clamping thrust against said clamp adjacent its apex, including a localized upward j 21; In a bending and forming brake, astation ary bed, a generally triangular clamp, the base of the clamp being pivoted adjacent the rear, of'the bed, theapexcof-the clampextending adjacent the lengthof the order of its'width, a clamp frame, of

thesame general length as the bed, pivoted to said bed adjacent the rear end of the bed, a clamp blade removably secured to the forward end of said clamp frame, and overlying the bed adjacent said free edge, means for directing a downward clamping pressure against said frame at a localized point generally midway of the width of the frame and nearer to the frontithan the rear of the bed, gauging means longitudinally adjustable on said bed, and bending means pivotally mounted adjacent the forward edge of said bed.

19. In a bending brake structure, a bed having a free forward edge readily accessible to an operator from in front of the bed, said bed having a length of the order of itsiwidth, a clamp frame, of the same general length as the bed, pivoted to said bed adjacent the rear endof thebed, a clamp blade removaibly secured to the forward end of said clampframe, and overlying the bed adjacent ized point generally midway of the width of the frame and nearer to the front than the rear of the bed, gauging means longitudinally adjustable onsaidbed, and bending means pivotallymounted adjacent the forwardedge of said bed, said clamppressure means including a clamping lever extending transversely across said bed above said frame, the opposed parts of clamping lever and frame being formed and adaptedto maintain contact over a limited area, one end of said clamping front of the bed,a bending blade structure secured adjacent the apex of said clamp and located adjacent the forward edge of the bed, and means for exerting a clamping thrust against said clamp adjacent. its apex including a pressure bar eX'tend-,

ing transversely across the clamp, means for lock ing the pressurebarin clampingposition and a contact'element interposed, between the clamp and. the pressure bar and means for bending upwardly any work whichis grippedbetween the bending blade structure, and the stationary bed.

2 2. In aibending and forming brake, arstationary bed, a generally trianuglar, clamp, the ,base of the clamp being pivoted adjacent the rear of the bed,rthe apex ofvthe clamp extending adjacent the frontofthe bed, a bending blade structure secured adjacent the apex of said clamp and located adjacent. the forward edge of the bed, and means for exerting a clamping, thrust against said clamp adj acentits apexincludinga pressure bar extending transversely across the clamp, means forlocking the pressure bar in clamping position anda contact element interposed between the clamp and the pressure bar, the area of contact between a said contact element and the, pressure bar being located on a line perpendicular to the pivotal. connection; between the base of the clamp and the rear of the bed, and means for bending upwardly any work-whichis gripped between the bending lever being pivoted to the bed,and an actuating lever, for said clamping lever, pivoted to said bed,

and connected to the free end of said clamping lever.

20. In a bending and forming brake, a stationary bed, a generally triangular clamp, the base of the clamp being pivotedadjacent the rearv of the bed, the apex ofthe clamp extending adjacent the front ofthe-bed, a bendinglblade structure secured adjacent the apex of said clamp and located adjacent the forward edge of thebed, and means for exerting a clamping, thrust against said clamp adjacent its apex including a pressure bar extending transversely across theclamp ad jacent its apex and in contact .with the, clamp adjacent the longitudinal axis of the clamp and means for locking the pressure bar in clamping position, and means for bending, upwardly any work which is gripped between the bending blade structure and the stationary bed.

, ,PETERKILHAM,

REFEnENoEsoI En V The following references are of record in the file of this patent: a v M c 'UNITEDs aT s P ATENTS Number Name Date 83,347 7 Whitney et a1 Oct. 20, 1868 366,486 Kimmel July 12, 1887 404,164 Buckman May 28, 1889 480,396 Clark Aug. 9, 1892 520,262 Geissinger cMay 22, 1894 711,404 Kunold Oct. 14, 1902 929,818 Benedek Aug. 3, 1909 1,806,986 Rucker May 26, 1931 2,128,295 Goodman Aug. 20,1938 1 2,208,061- -Warger July, 16,1940

FOREIGN PATENTS Number Country Date Great Britain May 19,1932

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