US2295108A

US2295108A - Power bender

Info

Publication number: US2295108A
Application number: US302632A
Authority: US
Inventors: William J Hall
Original assignee: Herron Zimmers Moulding Co
Current assignee: Herron Zimmers Moulding Co
Priority date: 1939-11-03
Filing date: 1939-11-03
Publication date: 1942-09-08
Anticipated expiration: 1959-09-08

Description

p 8, 9 2- w. J. VHALL 2,295,108

POWER BENDER Filed Nov. 3, 1939 4 Sheets-Sheet l 1 1v VENTOR A TTORNE Y Sept. 8, 1942;

v w. J. HALL Powmii BENDER Filed Nov 3, 1939 4 She ets-Shevet 2] )yallzkm Ii 52 v AZTORNE P 1942- 'w. .1. HALL I 2,295,108

POWER BENDER Filed NOV. 3', 1939 4 Sheets-Sheet NVENTOR TTORNEY v Sept; 8, 1942. w. J. HALL 2,295,108

I POWER BENDER Filed Nov. 3, 1939 4 Sheets-Sheet 4 0 /4 5' 5;: ,1 v 52', [/7 I), I r

IN VEN T OR 1 v ay me A TTORNE Ys.

Patented Sept. 8, 1942 UNlTED STT j QFFEC POWER BENDER Application November 3, 1939, Serial No. 302,632 19 Claims. (01. 15340) The invention relates generally to metal bending machines, and it has particular relation to a .machine for bending a window frame member plished easily and rapidly to the end that the cost of bending of the strips may be reduced as much as possible. Again it is important that the strip have a smooth surface at the bends, and in many instances with machines heretofore designed, it has been difficult to obtain a smooth surface in the region of sharp bends, at least economically.

Also, it is important that the machine be not too expensive to manufacture, and that its cost of maintenance be not too large. In the past, one objection to many of the machines designed has been that the initial cost is too large and that, due to complicated arrangements, shutdowns have been prolonged when one part of the machine failed to function. When it is considered that enormous numbers of Window frames are manufactured for use on automobiles, the importance that is attached to power benders may well be appreciated.

One object of the present invention is to provide an improved power bender which will enable obtaining greater rapidity in bending operations while still obtaining a finished product free from undesirable wrinkling or deformation.

Another object of the invention is to provide a power bender for accomplishing the results mentioned in the preceding object, which is inexpensive to construct and which is of simple character to the end that the cost of initial installation, the cost of repair, and delays incident to repairs will be reduced to a minimum.

Another object of the invention is to provide an improved power bender which is particularly adapted to effect the bending of metal strips of irregular contour, in the region of sharp bends, and to accomplish this sharp bending rapidly and smoothly.

Other objects of the invention will become apparent from the following specification, from the drawings relating thereto, and from the claims hereinafter set forth.

For a better understanding of the invention, reference may be had to the drawings wherein:

Figure 1 is a plan view of a power bender constructed according to one form of the invention;

Fig. 2\ is a side elevational view of the machine shown by Fig. l;

Fig. 3 is a cross-sectional view taken substantially along the line 3-3 of Fig. 2;

Fig. 4 is a cross-sectional view on a larger scale, taken substantially along the line 4-4 of Figure 1;

Fig. 5 is a cross-sectional view taken substantially along the line 5-5 of Fig. 4;

Fig. 6 is a cross-sectional view taken substantially along the line 6-45 of Fig. 4;

Fig. '7 is a cross-sectional view on a larger scale, taken substantially along the line 1-1 of Fig. 1;

Fig. 8 is a cross-sectional view taken substantially along the line 8-8 of Fig. 7;

Fig. 9 is a cross-sectional view on a larger scale taken substantially along the line 9-9 of Fig. 4;

Fig. 10 is a cross-sectional view taken substantially along the line Ill-ll] of Fig. 6;

Fig. 11 is a diagrammatic illustration showing an electric circuit which may be employed for controlling operation of the power bender;

Fig. 12 is a detailed view illustrating one of the window frames which has been formed from a straight strip by means of a power bender such as illustrated; and

Fig. 13 is a cross-sectional View on a larger scale, taken substantially along the line l3-l3 of Fig. 12.

Referring to Figs. 1, 2 and 3, the bender illustrated includes a top l6, uprights ll supporting the top, and a base [2 upon which the uprights are supported. Now directing attention particularly to Figs. 2 and 3, an electric motor i3 is mounted on the base l2 and is drivingly connected to a variable speed transmission 14 which has a pinion I5 in turn connected by means of a link belt it to a pinion ll mounted on a shaft is. The pinion I1 is loose on the shaft is excepting that it is positioned axially by means of a collar H] on the shaft, and opposite to the collar, the pinion is connected to a female clutch element 2!. A male clutch element 22 splined to the shaft and connected by means of linkage 23 to a clutch actuating member 24 is adapted to drivingly connect the pinion H to the shaft. Movement of the member 2 1 axially of the shaft may be accomplished by means of a conventional clutch engaging collar 26 and a bifurcated pivotal lever 27!, and it will be readily understood by those skilled in the art how such parts are constructed in detail.

The lever 21 is pivoted at a point indicated at 28 and is adapted to be moved about its pivot by means of a link 29 pivotally connected to a solenoid 32 which in turn is connected to a solenoid 3| by a pin 33. In this connection, it may be explained that when the solenoid 32 is energized, the clutch actuating member 24 is moved so as to cause the male and female clutch members to engage and when the solenoid 3! is energized, the clutch members are caused tobe disengaged, it being understood that only one of the solenoids is energized at a time.

The shaft It has another pinion 35 thereon that is keyed thereto and a solenoid brake 36 is provided at the end of the shaft opposite the clutch for stopping the shaft when the clutch is disengaged. A link belt 37 connects pinion 35 to a pinion 38 on an upper shaft 39 and as best shown by Fig. 2, the shaft 39 has a worm portion 40 which meshes with a worm. wheel The worm wheel in turn is keyed to the lower end of a vertical shaft 43 which projects upwardly through an opening in the top 53. It should now be understood that with the motor 23 constantly rotating, the shaft 43 may alternately be driven or be at rest depending upon actuation of the clutch operating solenoids. It may be mentioned that the driven parts described so far are enclosed within the base by means of a cover 45 which may have suitable opening or doors for allowing access to the parts.

As shown best by Fig. l the upper end of the shaft 43 turns in a sleeve bearing 53 located in the opening in the table II), and above the bearing, the shaft has an enlarged portion to which a plate 52 is secured by means of screws 53. A form block 54 in the form of an annulus substantially of the shape of the frame to be manufactured is rigidly secured to the plate 52 in any suitable manner, such as by screws, so that the form block and plate rotate together about the axis of the vertical shaft 43. At its outer side, the form block 54 as shown by Figs. 4 and 10, has an outwardly projecting flange 56 and this flange in conjunction with th upper surface of the form block and the vertical edg face above the flange, provides a seat of step formation adapted to receive a strip to be bent which is indicated at 51. With the understanding now that the form block 54 is rotated and that it has a stepped form for seating the strip 5?, it will be seen that if the strip is maintained against the. form block during rotation of the latter, the strip will be bent around the form block and willfinally assume the shape shown by l2. Mechanism for locking the strip to the form block at one point and for properly maintaining the strip against the form block during rotation of the latter will now be described.

Now referring to Figs. 1, 4, and 6, it will be observed that the plate 52 at its underside and around its margin has an annular channelwvay 60 and this channel-wa receives rollers 43! and 62 which are turnably mounted on a pivotal member 63. The member 63- is pivotally mounted on an enlarged portion 3 5 of a vertical stub shaft 65 fixed in an opening 68 of a slide 6?. A suitable bearing washer 68 and sleeve 69 are provided and a Washer 19 disposed in a countersunk recess in the member 63 is secured by screws H to the upper end of th shaft for anchoring the pivotal member 63 against vertical displacement upwardly from the slide. Now observing the peripheral contour of the channelway 68, and also observing that the rollers BI and 62 on the pivotal member 63 are disposed in alignment with the stub shaft 65 but at opposite sides thereof, it will be appreciated that when the plate 52 rotates, the pivotal member 63 can swing about the axis of the stub shaft 65 so as to accommodate its position to the curvature of the channel-way.

The slide 6'! is guided between opposed guideways 15 and 76 secured by screws T! to the top H], and is adapted to mov inwardly and outwardly depending upon inward and outward movement of the rollers 5| and 62 with respect to the axis of the shaft 43 during rotation of the plate 52. It has been mentioned that the pivotal member 63 turns about the axis of the stub shaft 35 depending upon the peripheral contour of the channel-way 3i} and in this connection attention is directed to the fact that a curved bearing plate 8! is provided on the slide 61 and this bearing plate has supporting engagement with conical rollers 8| and 82 on the pivotal member 63. The bearing plate 85 is so positioned and the conical rollers 8| and 82 are so shaped and positioned that as the pivotal member 63 swings about the axis of th stub shaft 65, the rollers 8| and 32 have a free rolling contact with the bearing plat 89 as distinguished particularly from a rolling contact such as would occur if the rollers were cylindrical.

From the description so far set forth, it will now be apparent that as the plate 52 rotates, the rollers 6| and 62 will be displaced inwardly and outwardly along the pathway of the slide 61 depending upon the change in shape of the channel-way 60 and at the same time such rollers will swing back and forth about the axis of the stub shaft 65 depending upon changes in direction of such channel-way. Such swinging of the rollers about the axis of the stub shaft 65 will cause the pivotal member 63 to swing about the axis of the shaft 65 and hence during rotation of the plate 52 the pivotal member 63 will swing about the axis of the shaft 65 and simultaneously may move inwardly and outwardly with the side 67. It might be mentioned at this time that the pivotal member 63 carries a wiper block for holding and pressing the frame member 57 against the form block 54 and from this it may be initially appreciated that due to the pivotal and inward and outward movement of the member 63, the wiper block may rapidly change its position in accordance with the contour of the form block.

Now referring to Figs, 4 and 5, it will be observed that the pivotal member 63 carries what may be termed a box-like member 85 which is open towards the form block 54 and which has an end wall 86 closing its opposite end. In the lower part of this box-like member, a block 81 is provided which at its center has an upwardly open recess 83 slidably receiving a nut 88 substantially fitting the recess so that the nut cannot turn. This nut is threaded on an intermediate threaded portion 90 of a pin 9| which passes longitudinally through the block 87 and externally through the end wall 86. Collars 92 and 93 secured on the pin at the outer side of the end wall and at the inner end of the block 8?, look the pin against axial movement and also lock the block in position against the end wall 35. The

outer end of the pin 9| has a polygonal head 95 by means of which it may be turned, and it follows that when the pin 9! is turned, the nut 89 is moved longitudinally of the recess 88 in one direction or the other depending upon the direction of turning.

Above the block 81 a slide 95 is provided within the box-like member 85, and this slide has a recess 91 for receiving compression springs 98 and 99. That end of the recess 91 next to the end wall 85 is open and the ends of the Springs at this end of the recess engage over pin-like elements IUII having collars IIII abutting the ends of the springs. The position of each pin element I is determined by means of a set screw M22 threaded through the end wall 86 and extending into an opening I03 in the collar IEII and pin element and which has a, lock nut I534 outside the end wall. In this manner the loading of the springs may be adjusted depending upon the pressure desired.

At its left end, each spring engages over a pin I01 provided on an end wall Hi8 at the other end of the recess 91 and thus the slide 95 is urged towards the form block 54. For limiting the inner position of the slide 95, pins IIQ and II I shown best by Fig. project downwardly from the lower wall of the slide and into the recess 88 of the block 81 and straddle the screw portion 98 at the outer side of the nut 89. It will now be apparent that by adjusting the position of the nut 89, the limiting position of the slide 95 may be governed since movement of the nut 88 will through engagement of the nut with the pins III] and III eifect or allow movement of the slide accordingly.

At the forward end of the slide 55, upper and lower arms I I2 and I I3 are provided and between these arms a bearing bracket H4 is pivotally arranged by means of a pin H5 passing vertically through apertures in the arms and in the bracket. The bearing bracket as shown best by Fig. 9, has a flange or plate portion I I5 and at the front side of this plate, a wiper support I I1 is provided and such a support is secured to the plate I I6 by means of screws I25. Such support II?) has spaced projections I2I and I22 terminating at their forward ends in vertically disposed cylindrical portions and a pivotal member I23 has a restricted opening receiving the cylindrical projection I2I while a similar member I24 receives the cylindrical projection I22. The members I23 and I24 slidably rest on the plate 52 and while movable vertically on pivots I22 and HI, it will be observed that in operative positions, the members have lower flange portions I25 which project under the flange 55 of the form block 54 and thus upward movement is definitely limited. Pivotal movement of the members I23 and I24 about pivots IEI and IE2 is limited as is evident in Fig. 9.

As shown particularly by Fig. 4, the member I23 has vertically spaced, but upwardly inclined surfaces I21 and I28 and such inclined surfaces are adapted to fit and guide a movable wiper block I30. Such block is maintained movably assembled with the member I23 by means of screws I35 threaded downwardly through the member at right angles to the inclined surface I21 and on opposite sides of pivot I2! and which have their lower ends slidably positioned in slot-s I36 in the block. Also inclined screws i351 are provided on opposite sides of pivot I2I and each screw is threaded through a, wall I32 of the bearing bracket and has its free end projecting into an opening I39 in the block. Between the block and wall I38, a spring I40 is provided around each screw from which it follows that normally the springs urge the block along the inclined surfaces I21 and I28.

The screws I31 and I35 are located at right angles to each other and this arrangement in conjunction with the inclined surfaces mentioned before, holds the block assembled with the member I23, while it still permits limited movement of the block along'the inclined surfaces.

The member I24 similarly supports a block hi3 shown by Fig, 9. The blocks I 38 and I43 are arranged similarly to the members I23 and I22 so that each block and its supporting member may rock with respect to the other block and its supporting member within limits. An arm I45, having a rounded edge I41, is fastened to the upper side of the bearing bracket II1 by means of screws I46 as shown by Fig. 9, and this arm is adapted to automatically release the strip clamping means that will be described presentl Referring to Figures 9 and 10 in particular, the block I30 has an extension I50 adapted to contact the lower angular portion only of the strip 51 so as to effect or obtain wiping action over a greater linear portion of the vertical web and the lower flange of the strip. The block I23 has an extension I5I projecting longitudinally under the flange of the form block 54 and this extension has spaced openings I52 and I 53 which constitute guideways for pins I54 and I55 projecting from a bar I56. This bar at its side next to the form block 54 has a flange I58 seen as contacting the edge face of the flange 56 of the form block while at the opposite side of the bar I56, a pin I60 extends through an offset portion IBI of a bracket I62 secured by screws I53 to the extension I5I. A spring I55 around the pin I65] between the bar I56 and the offset I6I constantly urges the bar and the flange portion I58 towards the flange 56 on the form block. Preferably the wiper blocks I35 and I23 will be constructed from a softer metal such as brass in order to prevent scratching of the frame member 51.

For holding one end of the strip 51 in locked relation to the form block, a locking arrangement is provided which is particularly shown by Figures '1 and 8. As shown by Figure 8, the form block is notched out as indicated at I10 and within the notch a pivotal locking element I1I is provided which is pivoted on a screw element I12 threaded into the form block. A lip I13 is provided on the element HI and adapted to clamp the vertical flange portion of the strip 51 against the vertical face of the form block 54. For turning the clamping element i'II about the pivot I12, a pin I15 is provided which has an eccentric pin portion I18 disposed in an elongated opening I11 in the element and when the pin I15 is turned, the clamping member I1I is turned about the pin I12. At its upper end, the pin I 15 extends through a bearing plate I fastened to the form block and a long handle I8I is secured to the pin to facilitate turning thereof. A limit stop pin I82 projects upwardly from the bearing plate I so as to limit clockwise turning movement of the arm I BI to a clamping position. A short arm I83 is also fastened to the pin I15 and, with reference to Fig. 1, when the arm I8I is turned clockwise until it engages the limit pin I82 so as to eifect clamping of the end of the strip 51, the short arm will be turned to a position where it will strike the arm I45 on the wiper block device when the bending operation is completed. This automatically effects unclamping of the strip.

Now directing attention to Figs. 1 and 4, it is to be observed first in Fig. 1 that the channelway 65 along the longer side adjacent the strip clamping means, continues in a straight line or direction, whereas the form block diverges inwardly to the clamping means and then outwardly from the clamping means. It will be understood that the limit nut 89 in Fig. 4 may be so set as to allow the

main springs

98 and 99 to hold the wiper blocks strongly against the strip during the bending operation, while at the same time the setting of the nut in conjunction with the divergence of the channel-way and form block may be such as to cause the wiper blocks to be pulled away from the strip or form block. Thus with the parts positioned as in Figs. 1 and 4, the wiper blocks are away from the form block and thisallows easy initial linear insertion of a new strip as well as removal of the finished frame. The adjustment of nut 39 in conjunction with the divergence of the channel-way 59 and form also will be such as to allow the wiper blocks to pass over the locked clamping means without interference. In this connection it will be understood that if the wiper blocks are moved away from the form block and strip completely, the wiper blocks may be urged upwardly along the inclined surfaces I27 and 238 but are prevented from separating from such surfaces by the guiding screws or pins I35 and I31. However, when the wiper blocks are moved inwardly against the vertical web part of a new strip 51, such blocks and the supports I23 and I24 have relative movement along the inclined surfaces I27 and I28 until the blocks forcefully contact the horizontal and vertical parts of the strip and the flange portions I25 of the supports forcefully contact the under side of the flange 56 of the form block 54. Thus the strip is tightly clamped both in a vertical direction and in an horizontal direction, although the clamping action will be of such nature as to allow the parts to have sliding contact during operation of the machine.

With reference to Fig. 11, the main lines of an electric circuit are indicated by the numerals I 84 and I85 and it will be observed that two circuits I88 and 58'! adapted selectively to be energized are employed. A two-way switch I88 is adapted to open one circuit and close the other and vice versa, and this switch is normally held by spring I89 in such position that the circuit I8? is energized. This circuit I8! includes the solenoid SI for throwing the clutch out and also includes the brake solenoid 35 which actuates the brake mechanism for quickly stopping the shaft I8 when the clutch is thrown out. A switch I92 normally held in a closed position by a spring M3 is in the circuit I35 and this switch is adapted to be opened as shown by Figure 1, by a cam I94 on shaft I8 which is engageable with a roller I95 on the end of a movable bar I96 pivotally connected to the switch I92. Normally, the spring I93 within the switch box urges the bar I96 toward the center of the machine and the switch into closed position and it is only when the cam I94 moves over the roller I95 that the switch is opened. It is to be understood that as soon as the cam passes the roller I95, the switch returns to closed position.

A manually operated switch I98 located at a convenient place as seen in Figure 1, is adapted to initiate operation of the machine and this starting switch closes an auxiliary circuit 299, including a coil 29I which throws the switch I88 into position where it closes the circuit I86. As soon as the switch I88 closes the circuit I 86, it also energizes a holding circuit 293, including a coil 294, which holds the switch in the position wherein it closes the circuit I86. Manual release of the starting button will then have no effect since the holding coil 294 maintains the circuit I closed. When the circuit I86 is closed, the solenoid 32 is energized, and simultaneously the solenoid 3I and the brake solenoid 36 are deenergized and accordingly, the clutch parts are engaged, the brake is released, and the machine starts operating. It will be understood that the cam I94 is barely past the roller I at the beginning of the operation and it follows that the circuit I86 will be maintained in a closed condition until the cam again reaches the roller I95 and then the switch I92 will be opened temporarily while the cam passed the roller. Opening of the switch I92 de-energizes the coils 32 and 294 and then the spring I89 returns the switch I88 to its other position wherein the clutch throw-out solenoid 3| and the brake solenoid 36 are energized. This stops the machine quickly, but it will be understood that the momentum is such and there is enough delay in the action to permit the cam I94 to move past roller I95 sum-- ciently to allow the switch I92 to return to its closed position. It follows that the parts are again set for manual starting by pushing of the button 98.

Assuming that the parts are in positions as seen in Figure 1, a new strip 57 is linearly inserted past the wiper means until the end of the strip is under the clamping lip I13. Then the handle I3! is turned clockwise until it engages the pin I 82 and this operation tightly clamps the end of the strip to the form block. The manual switch I99 is then actuated to initiate operation of the machine, and this eifects rotation of the plate 52 and the form block 54. As the plate r0- tates in a clockwise direction, the slide 61 and all of the parts carried thereby move outwardly in the guideways I5 and I6 owing to the fact that the rollers GI and 62 follow the channel-way 60 and that part of the latter over the slide becomes more distant to the rotational axis as the plate turns. At the same time, the space between those parts of the form block and channel-way over the slide becomes less as the plate turns until the first bend in the form block and channel-way reaches the slide. As the channel-way and form block converge in their movement over the slide 61, the slide and wiper parts carried thereby necessarily become positioned nearer to the form block and the arrangement is such that the wiper blocks will contact the metal strip 5"! at a point adjacent to the first bend in the form block.

With particular reference to Figure 4, it will be observed that before this contact of the strip with the wiper blocks occurs, the latter are in higher positions on the inclined surfaces of the wiper block supports but when the wiper blocks contact the vertical flange portion of the strip 5'], the wiper blocks and wiper block supports have relative movements along the inclined surfaces thereon until the wiper blocks are drawn downwardly into tight frictional engagement with the horizontal surfaces of the strip 57 and the flange portions I25 of the wiper block supports are drawn upwardly into similar fitting engagement with the under side of the flange 56 of the form block. The form block, in pushing outwardly against the wiper blocks, first effects this clamping engagement of the blocks with the metal strip and then upon sufficient outward movement of the form block relative to the .outward movement of the slide 61, the outward movement of the form block will finally cause the slide 96 to move sufiiciently to separate the limiting pins III! and III from the adjustable nut 89. It follows from this that near the beginning of the first bend in the form block, the

springs

98 and 99 come into action to exert strong resilient pressure against the wiper blocks and the metal strip 51.

As the first bend in the form block passes over the slide 61, the roller 52 on the pivotal member 63 is taking the first turn in the channel-way 60 and this efiects swinging of the pivotal member about the axis of the stub shaft 65, and it thus follows that the pivotal member will roll over the bearing element 80. Now due to the pivot H carrying the wiper block parts on the end of the slide 96, and due to the fact that the slide 96 can move, the wiper blocks will tend to lag behind the movement of the pivotal member 63 in its swin ing movement, so that the wiper blocks will tend to maintain resilient ironing pressure on the metal strip 51 in lagging relation to the movement of the pivotal member 63. This is important as the strip will be ironed, so to speak, by a lagging movement of the wiper blocks around the bend.

During the movement of the parts as so far described, and also during succeeding movements, it is desirable that the metal strip 51 be maintained against twisting as it approaches the form block and prevention of this twisting is effected by the member I58, shown by Fig. particularly. This member I58 provides a support for the strip 51 and guides it properly into position between the form block and wiper blocks and especially when the strip is being bent around the bends of the form block, this is important, as twisting is apt to occur unless the strip is substantially supported. It should be stated in this connection, that as the wiper blocks begin to move around the bend in the form block, the wiper block I39 and its support I23 cannot maintain full surface contact with the form block as line contacts necessarily are involved, one on each wiper block. Since these line contacts will be approximately in the region of the pivotal projections I2I and I22, as seen in Fig. 9, it will be evident that at the advancing side of the block I38, the metal strip will not be held against the form block and will diverge therefrom. The projection I58 provides a support for the strip where it diverges from the form block and the spring mounting of this member tends to eliminate any gap between it and the form block flange, whereby continuity in the supporting surface for the diverging part of the strip may be maintained.

By providing both of the form blocks I30 and I43, and having them pivot relative to each other, it has been found that the tendency of wrinkles is even further decreased since the first form block will provide and advance wiper action and the second or lagging wiper block will iron out any wrinkles that possibly might have been left in the strip after the first wiper block has effected the bending action over the metal.

Bending of the strip about the remainder of the form block is effected in a similar manner, and it will be appreciated that as the bending operation is continued, the slide 61 will move inwardly and outwardly and the pivotal member 63 will swing in one direction and the other, depending upon the bending that is taking place. The arrangement is of such character that, relatively speaking, the pivotal member 63 swings rapidly around each bend and. the metal strip is ironed around such bend in a rapid manner without wrinkling or twisting.

After the final bend in the form block passes the wiper mechanism, the channelways 60 and form block again diverge until finally the limit pins III) and HI again strike the nut 89, as seen in Fig. 4, and following this the wiper blocks move upwardly along the inclined surfaces mentioned, and finally assume the positions initially described, wherein they are substantially separated from the form block to permit easy removal of the finished frame and insertion of a new strip to be bent. During final movement of the plate 53 and form block, the arm I65 strikes the arm- I83 on the clamping means and the latter is automatically turned backwardly by this action so as to release the metal strip. Then the cam I92 moves the rod I96 outwardly so as to open the switch I2 temporarily and from the previous description set forth, it will be-appreciated that operation of the mechanism will now cease with the parts again in positions as shown by Figure 1. As seen in this figure, it is only necessary then to raise the bent strip from the lower part of the form block and then to slide it upwardly in order to remove the strips from the block. It will be understood that the ends of the finished frame may then be Welded to form an integral structure.

It will be apparent that by changing the form block which usually will be bolted to the top, and by changing the wiper blocks so as to have blocks of different contour, frame members of different sections may be bent and that-by using different tops provided with varying channel-ways and form blocks, numerous shapes may be bent, still in accordance with the invention.

Although only one form of the invention has been described in detail, it will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the invention claimed.

What is claimed is:

1. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphry of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, means on the slide engaging said guideway to effect movement of the slide inwardly and outwardly in accordance with the movement of said guideway, wiper means movably carried by the slide for pressing the strip against the periphery of the block as the latter rotates, and resilient means for moving the wiper means relative to the slide and towards the periphery of the block, said guideway being of such character that the wiper means is operatively held away from the periphery of the block along a predetermined portion of the latter adjacent the clamping means.

2. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, means on the slide engaging said guideway to effect movement of the slide inwardly and outwardly in accordance with the movement of said guide- Way, wiper means slidably carried by the slide for pressing the strip against the periphery of the block as the latter rotates, and resilient means for moving the wiper means relative to the slide and towards the periphery of the block, said guideway being of such character that the wiper means is operatively held away from the periphery of the block along a predetermined portion of the latter adjacent the clamping means.

3. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotal movement about an axis parallel to the axis of rotary movement of the block, means on the plate engaging the guideway to effect movement of the slide inwardly and outwardly in accordance with the movement of said guideway, Wiper means slidably mounted on the plate for pressing the strip against the periphery of the block, and resilient means for moving the wiper means relative to the slide and towards the periphery of the block.

4. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotal movement about an axis parallel to the axis of rotary movement of the block, a pair of turnable elements on the plate engaging said guideway on opposite sides of the pivotal axis of the plate, and wiper means carried by the plate separately of the turnable elements for pressing the strip against the periphery of the block.

5. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotal movement about an axis parallel to the axis of rotary movement of the block, means on the plate and engaging said guideway for effecting movement of the plate and slide in accordance with the movement of the guideway, a second slide on the plate and movable towards and from the plate pivot, a wiper block on the second slide, andresilient means on the plate urging the second slide towards the plate pivot.

6. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotal movement about an axis parallel to the axis of rotary movement of the block, means on the plate engaging the guideway for eifecting inward and outward movement of the plate and slide in accordance with the movement of the guideway, a second slide on the plate and movable, towards andaway from the plate pivot, resilient means on the plate for urging the second slide towards the plate pivot, and a wiper block pivotally carried by the second slide for pressing the strip against the form block.

'7. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotal movement about an axis parallel to the axis of rotary movement of the block, means on the plate engaging said guideway for effecting inward and outward movement of the plate and slide in accordance with the movement of the guideway, a second slide on the plate andv movable towards and from the pivotal axis of the plate, resilient means urging the second slide towards said plate axis, a Wiper block supporting member pivotally mounted on the second slide for pivotal movement about an axis parallel to the other axes, and a wiper block carried by said supporting member.

8. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the, block, a slide on, the support, means on-the support, for directing the movement of the slide sothat it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotalmovement about an axis parallel to the axis of ro tary movement of the form block, a pair of rollers on the plate having their axes disposed parallel to the plate pivot and being located at opposite sides of such plate pivot, said. rollers engaging said guideway so that. inward and outward movement of the plate and slide is effected in accordance with the movement of the guideway, a, second slide carried by therplate forrmovement towards and from the plate pivot, resilient means urging the, second slide towards suchplate pivot, a wiper block supporting member pivoted on the second. slide on a pivotal axis parallel to the other axes, and a wiper block pivotally carried by the supporting member for pivotal movement, about another axis parallel to the others.

9. A machine for bendingv ametalstrip'comprisin a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotal movement about an axis parallel to the axis of rotary movement of the form block, a pair of rollers on the plate having their axes disposed parallel to the plate pivot and being located at opposite sides of such plate pivot, said rollers engaging said guideway so that inward and outward movement of the plate and slide is effected in accordance with the movement of the guideway, a second slide carried by the plate for movement towards and from the plate pivot, resilient means urging the second slide towards such plate pivot, a wiper block supporting member pivoted on the second slide on a pivotal axis parallel to the other axes, and a pair of wiper blocks pivotally carried by the supporting member for pivotal movement about spaced axes parallel to the other axes.

10. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotal movement about an axis parallel to the ax s of rotary movement of the form block, a pair of rollers on the plate having their axes disposed parallel to the plate pivot and being located at opposite sides of such plate pivot, said rollers engaging said guideway so that inward and outward movement of the plate and slide is effected in accordance with the movement of the guideway, a second slide carried by the plate for movement towards and from the plate pivot, resilient means urging the second slide towards such plate pivot, a wiper block supporting member pivoted on the second slide on a pivotal axis parallel to the other axes, a pair of Wiper block carrying elements pivoted on the supporting member for pivotal movement respectively about spaced axes parallel to the others, and a wiper block slidably and resiliently mounted on each element.

11. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a slide on the support, means on the support for directing the movement of the slide so that it may move inwardly and outwardly relative to the periphery of the form block, a plate pivotally mounted on the slide for pivotal movement about an axis parallel to the axis of rotary movement of the form block, a pair of rollers on the plate having their axes disposed parallel to the plate pivot and being located at opposite sides of such plate pivot, said rollers engaging said guideway so that inward and outward movement of the plate and slide is effected in accordance with the movement of the guideway, a second slide carried by the plate for movement towards and from the plate pivot, resilient means urging the second slide towards such plate pivot, a wiper block supporting member pivoted on the second slide on a pivotal axis parallel to the other axes, a pair of wiper block carrying elements pivoted on the supporting member for pivotal movement respectively about spaced axes parallel to the others, and a wiper block slidably and resiliently mounted on each element, said wiper block being slidable on surfaces angled to said axes so that they may slidably move not only to and from the periphery of the form block but also longitudinally of the axis of the form block.

12. In a bending machine for bending a metal strip having angularly related portions, a form block on the support about the periphery of which the strip is to be bent and having a first surface generally in the plane of the block and a second surface upstanding to such plane so as to substantially fit the strip, a wiper block carrying element on the support and having a surface inclined tothe plane of the form block, a wiper block on said element having an inclined surface fitting the inclined surface on the element and also having a first surface substantially parallel to the first surface of the form block and a second surface substantially parallel to the second surface on the wiper block, means retaining the element and wiper block assembled while allowing their relative movement along said inclined surfaces, means for urging the element towards the periphery of the form block, and means for effecting relative movement of the blocks along the periphery of the form block, the arrangement being such that when the wiper block is moved against the periphery of the form block with a strip in position on the latter the second surfaces on the blocks press against one angular or flange portion of the strip therebetween with the pressure then causing the wiper block to move along the inclined surface plane until the first surfaces on the blocks press the other angular or flange part of the strip therebetween.

13. In a bending machine for bending a metal strip having angularly related portions, a form block on the support about the periphery of which the strip is to be bent and having a, first surface generally in the plane of the block and a second surface upstanding to such plane so as to substantially fit the strip, a wiper block carrying element on the support and having a surface inclined to the plane of the form block, a wiper block on said element having an inclined surface fitting the inclined surface on the element and also having a first surface substantially parallel to the first surface of the form block and a second surface substantially parallel to the second surface on the wiper block, means retaining the element and wiper block assembled while allowing their relative movement along said inclined surfaces, relatively light pressure resilient means urging the element and wiper block apart, relatively strong resilient means urging the element towards the form block, and means for effecting relative movement of the blocks along the periphery of the form block, the arrangement being such that when the wiper block is moved against the periphery of the form block with a strip in position on the latter, the second surfaces on the blocks to press one angular or flange of the strip therebetween with the pressure then causing the wiper block to move along the inclined surface plane until the first surfaces on the blocks press the other angular or flange part of the strip therebetween,

14. In a bending machine, a support, a form block on the support about the periphery of which a metal strip is to be bent, a wiper block carrying element on the support and having a surface inclined to the plane of the form block, a wiper block on said element having an inclined surface fitting the inclined surface on the element and also having a surface substantially parallel to said plane and adapted to press a part of the strip against a like parallel surface on the form block when the block moves along said inclined surfaces, means for moving the carrying element in a direction substantially parallel to said plane and towards the periphery of the form block, means on the wiper block engageable with the form block for effecting movement of the wiper block along said inclined surfaces when the carrying element is moved towards the form block whereby said part of the strip is pressed against the form block, and means for effecting relative movement of the form block and carrying element along the periphery of the form block.

15. In a, bending machine, a support, a form block on the support about the periphery of which a metal strip is to be bent, a wiper block carrying member mounted on the support for movement towards and from the form block, a Wiper block, means movably mounting the wiper block on the member for movement transversely to the plane of the form block, said wiper and form blocks having surfaces substantially parallel to said plane and between which a part of the strip is pressed when the wiper block is moved in said transverse direction, means on the wiper block engageable with the form block and cooperable with the first means for efiecting movement of the wiper block in said transverse direction when the carrying member is moved towards the form block, so as to effect pressing of the strip between said surfaces, and means for eifecting relative movement of the form block and carrying mem her along the periphery of the form block.

16. A machine for bending a strip of angular character, comprising a form block about the periphery of which the strip is to be bent and which has a first surface in its own plane and a second surface transverse to said plane for engagement respectively with the angular parts of the strip, a wiper means having similarly related first and second surfaces for pressing the angular parts of the strip against the corresponding surfaces on the block, means for moving the wiper means in a direction towards the form block and in the plane thereof to press a part of the strip between the first surfaces, means depending upon engagement of the first surface on the wiper means with said part of the strip for so moving the wiper means that the second surface of the wiper means is moved into engagement with the other part of the strip, and means for effecting relative movement of the Wiper means and form block along the periphery of the latter.

17. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a member movably mounted on the support for movement inwardly and outwardly relative to the periphery of the form block, an element on the member engaging the guideway to efiect movement of the member inwardly and outwardly in accordance with the movement of the guideway, wiper means movably carried by said member for pressing the strip against the periphery of the form block as the latter rotates, and resilient means for moving the wiper means relative to said member and towards the periphery of the block, said guideway being of such character that the wiper means is operatively held away from the periphery of the block along a predetermined portionof the latter adjacent the clamping means.

18. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a member movably mounted on the support for movement inwardly and outwardly relative to the periphery of the form block, an element on the member engaging the guideway to effect movement of the member inwardly and outwardly in accordance with the movement of the guideway, wiper means slidably carried by said member for pressing the strip against the periphery of the form as the latter rotates, and resilient means for moving the wiper means relative to said member and towards the periphery of the block, said guideway being of such character that the wiper means is operatively held away from the periphery of the block along a predetermined portion of the latter adjacent the clamping means.

19. A machine for bending a metal strip comprising a support, a rotary form block on the support and about the periphery of which the metal strip is to be bent and which has an annular guideway, means for clamping one end of the strip to the block at one point on the periphery of the block, a member movably mounted on the support and having means engaging the guideway so that the member may move inwardly and outwardly in accordance with the movement of the guideway, a plate pivotally mounted on the member for pivotal movement about an axis parallel to the axis of rotary movement of the block, wiper means slidably mounted on the plate, and resilient means for moving the wiper means relative to the member and towards the periphery of the block.

WILLIAM J. HALL.