US3851518A

US3851518A - Bending apparatus for bending strip steel knives

Info

Publication number: US3851518A
Application number: US00320154A
Authority: US
Inventors: E Spengler
Original assignee: SKOMAB INT MASCHINEN U STAHL H
Current assignee: SKOMAB INT MASCHINEN U STAHL H
Priority date: 1972-01-04
Filing date: 1973-01-02
Publication date: 1974-12-03
Anticipated expiration: 1991-12-03
Also published as: AT322323B

Abstract

The present bending apparatus is constructed for bending strip material, for example, steel strips in any desired direction and thus into shapes for example such as steel strip punching knives. For this purpose pairs of clamping jaws arranged on a turntable cooperate with reciprocable hammer means. The hammer means have preferably two peens which either face each other or which face in opposite directions.

Description

United States Patent Spengler Dec. 3, 1974 BENDING APPARATUS FOR BENDING [56] References Cited STRIP STEEL KNIVES UNITED STATES PATENTS [75] Inventor: Ernst M. Spengler, Heusenstamm, 429,989 6/1890 Adams 72/384 Germany 1,636,786 7/1927 Rolley p 3,052, 277 9/1962 St an 72/380 Asslgneei SKOMAB International Maschme" 3,641,803 2 1972 sciii drbi ers et al. 72/38] und Stahl Handelsgesellschaft Ausma Primary ExaminerC. W. Lanham [22] Filed; Jan, 2, 1973 Assistant Examiner-James R. Duzan Attorne A ent, 0r Firm--Wolf an G. Fasse; Willard 21 Appl. No.: 320,154 W Robyertsg g g [30] Foreign Application Priority Data [57] ABSTRACT Jan. 4, 1972 Germany 7200095 The present di apparatus is constructed f Nov. 16, 1972 Germany 2256113 b di g Strip material, f example, steel Strips i any desired direction and thus into shapes for example [52] US. Cl 72/384, 72/76, 72/380, Such as Steel Strip punching knives For this purpose 72/381 pairs of clamping jaws arranged on a turntable cooper- [51] Int. Cl 321d 17/02 ate with reciprocable hammer means The hammer [58] Field of Search 72/307, 384, 217, 149, means h referably two peens which either face each other or which face in opposite directions.

32 Claims, 10 Drawing Figures PATENTEL E53 3 I974 SHEU 10F 6 PATENTEL 3,851,518. sum 20F e NQI PATENTE BEE 3l974 I SHEEF 5 BF 6 PATENTELBEE 3,851,518

. sazasnr e J FIG.9

' FIG. IO I W BlENDING APPARATUS FOR BENDING STRIP STEEL KNIVES BACKGROUND OF THE INVENTION The present invention relates to a bending apparatus for bending strip material into shapes, more specifically, for bending steel strip stock into strip punching knives. Such apparatus generally include a worktable with counterholding jaws or gripping jaws and driven hammer means including a hammer head.

By means of these devices steel strip stock is bent into the desired shape, for example, of punching knives, whereby the steel strip stock is cut to the required length prior to the bending operation. The bending operation itself employs hammer strokes which in cooperation with the counterholding jaws cause the desired bending. However, if the steel strip stock is to be bent in more than one direction or if the desired shape is not accomplished by the bending operation, it may become necessary to straighten the steel strip stock again. For this purpose it was necessary in connection with prior art bending devices to remove the punching knife from the apparatus and to reinsert it in such a manner that the hammer could now become effective on the convex side of the bend steel strip material. Further, it has been necessary heretofore that at least one end of the steel strip stock must be held by the operator. This is rather undesirable due to the strokes applied by the hammer on the steel strip stock.

OBJECTS OF THE INVENTION In view of the above it is the aim of the invention to achieve the following objects singly or in combination:

to provide a bending apparatus for strip stock which is free of the above mentioned disadvantages;

to provide a bending apparatus for strip stock which is capable of bending the strip stock in opposite directions without removing the workpiece from the bending apparatus;

to provide such a combination of cooperating elements that the holding of the free end of the strip stock by the operator may be eliminated;

to provide sensing means which sense the reciprocation of the hammer head for controlling the adjustment of the position of the hammer means so that the entire bending operation may proceed automatically;

to provide a hammer head with two peens which either face each other or which face in opposite directions;

to provide means which will hold a template relative to the hammer means and to the counterholding jaws so that the shape of the bend strip stock may conform to the shape of the template; and

to provide feed advance means for the strip material which may assure a continuous feed of the strip material into the hammering area although the strip material as such is momentarily stopped when the hammer head hits the strip stock.

SUMMARY OF THE INVENTION The above objects have been achieved according to the invention by making the worktable along with the counterholding jaws and the hammer means rotatable, for example, by means of a turntable and by providing positioning means outside the turntable in such a mannor that these positioning means will fix one end of the steel strip material. The positioning or holding of the steel strip material at a point outside of the turntable has the advantage that it is not necessary any more for the operator to take up the hammering strokes applied to the workpiece. This arrangement of the turntable has the further advantage that the holding means arranged outside the turntable may be rigidly secured to the frame structure of the entire apparatus.

According to the invention there is further provided a hammer head which is effective on both sides of the strip material or in two directions so to speak and that two pairs of counterholding jaws are provided which include peens arranged opposite each other and which are spaced from each other as well as releasably and adjustably secured to the turntable. This arrangement according to the invention has the advantage that left as well as right turns may be accomplished without resetting the workpiece on the apparatus. In addition it is possible to make corrections in the bending without any substantial additional work.

BRIEF FIGURE DESCRIPTION In order that the invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein:

FIG. 1 is a top view of a somewhat simplified illustration of an apparatus according to the invention and showing the production of a left turn bend;

FIG. 2 is a view similar to that of FIG. 1 but showing a right turn bend;

FIG. 3 illustrates the severing of the steel strip knife from the steel strip stock;

FIG. 4 is a view similar to that of FIGS. 1 to 3, however, showing a different hammer head configuration;

FIG. 5 illustrates a modified embodiment of an apparatus according to the invention as viewed in the direction of the arrows 5-5 in FIG. 6 and showing that the counterholding jaws as well as the hammer head have a C-shape, whereby the free ends of the C-shape form a slot for the insertion of a template to the shape of which the punching knife is conformed;

FIG. 6 is a top view onto the embodiment according to FIG. 5;

FIG. 7 illustrates a top view onto a modification of the embodiment according to FIG. 5;

FIG. 8 is a sectional view along the section line 8-8 in FIG. 1 showing specifically the turntable and the drive means for the hammer head while omitting most of the frame structure of the apparatus;

FIG. 9 is a top view illustrating a further modification of an apparatus according to the invention with an outrigger means for supporting a template and also showing a shiftably and yieldably supported carrier block for I a strip material feed mechanism; and

FIG. 10 illustrates a side view of the apparatus according to FIG. 9.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS Referring first to FIGS. 1 to 3 there is shown an embodiment of a bending apparatus 1 according to the invention for bending steel strip knives from steel stripwhich is supplied from a cassette of the like not shown. FIG. 1 illustrates the bending of a left turn in the strip stock 5. According to the invention there is provided a turntable 2 and means for positioning or holding the strip stock at a point outside the turntable 2. These holding means comprise two driven rollers 3 and 4 which serve on the one hand for the automatic feed advance of the strip material 5 and which on the other hand fix the position of one end, so to speak, of the steel strip 1 while the strip material is being worked.

Hammer means 6 are provided for bending the steel strip 5 into the desired shape. The hammer means comprise a hammer head 7 which cooperates with, for example, four

counterholding jaws

8, 9, 10 and 11.

The hammer head 7 is driven by motor means and is movable or reciprocable along a path extending between the counterholding jaws and through the center of the turntable 2. Preferably, the path of reciprocation of the hammer head 7 extends perpendicularly to the axis of rotation of the turntable 2. The drive means for the hammer head 7 will be described in more detail below with reference to FIG. 8.

The hammer head 7 is effective in a double sense. For this purpose the hammer head 7 is provided as shown in FIGS. 1 to 3 with a recess 12 into which the strip steel 5 is inserted prior to the begin of the bending operation.

The recess 12 has a length which is somewhat longer than the length of the hammer stroke. Each end of the recess is defined by

hammer members

13 and 14, each of which is provided with a respective peen l5 and 16. These peens face each other as shown in FIGS. 1 to 3.

The apparatus according to FIG. 1 operates as follows. The hammer member 13 hits with its peen l6 and the steel strip 5 which is supported by the counter holding jars 8 and 9 and which is deformed in accordance with the force and duration of the hammer strokes. Due to such deformation the steel strip 5 is bent somewhat inwardlyinto the space between the ends of the counterholding jaws which ends are formed as peens. Simultaneously with this deformation the turntable 2 is rotated in the direction of the arrows P. This rotation of the turntable is not accomplished by means of a special external drive, but rather solely due to the forces occurring as a result of the deformation of the steel strip 5 when one end of the steel strip is precisely held as to its position by the holding means including the rollers 3 and 4.

If, for example, during the working of the steel strip it should be noticed that the applied bend is too large or if the next following bend shall extend in another direction, then the hammer member 14 with its peen 15 will be employed which will then hit the steel strip 5 resting against the counterholding jaws l0 and 11. For this purpose, it is merely necessary to displace the hammer means 6 or the hammer head 7 in the direction toward the two counterholding jaws l0 and 11 in such a manner that the peen 15 may now cooperate with the

jaws

10 and 11 for achieving the desired result with the hammer stroke. For this displacement or adjustment of the hammer head or hammer means there is provided a slide carrier 42 illustrated in FIG. 8. With the aid of this slide carrier 42 the entire hammer means 6 is adjustable relative to the center of the turntable 2.

Upon the completion or upon the substantial completion of the desired shape of the punching knife, the latter is severed from the steel strip stock by means of a cutting edge 17 provided at the rear end of the

hammer members

13 or 14. For this purpose the steel strip stock 5, as may be seen in FIG. 3, is inserted into holding grooves 18 in the

counter holding jaws

8 and 9 or 10 and ill, whereupon the severing is accomplished with the aid of the drive means 41 which reciprocate the hammer means 6.

FIG. 4 illustrates another shape or configuration of a hammer head 7a which comprises two

peens

15a and 16a facing away from each other. This hammer head is suitable for producing, in the same manner as described above with regard to FIGS. 1 to 3, right as well as left bends in a steel strip stock 50. For this purpose, it is merely necessary to displace the hammer means relative to the turntable 2a in such a manner that it may cooperate with the

counterholding jaws

8a and 9a or with the counterholding jaws 10a and 11a.

FIGS. 5 and 6 illustrate a further embodiment of a hammer head 7b and two

counterholding jaws

8b and 9b which have the configuration of a C-shape. This embodiment is suitable for directly working the steel strip stock 5b while the stock rests against a template 21b. It should be noted here that the side view of FIG. 5 is in the direction of the arrows 55 in FIG. 6 so that it makes visible the C-shape of the counterholding jaw 9b. However, the configuration of the hammer head 7b corresponds basically to the same C-shape.

The hammer head 7b as well as the two

counterholding jaws

8b and 9b reach around the steel strip 5 substantially completely and merely a narrow slot 22b remains open for the insertion of the template 21b. The hammer head 7b and the two

counterholding jaws

8b and 9b have said C-shape, whereby the free ends of the

legs

23b, 24b carry supporting

members

25b and 26b respectively. The peens 27b are arranged along the vertical connecting land of the C-shape of the

counterholding jaws

8b, 9b and of the hammer head 7b. Thus, these peens extend from the leg 23b to the leg 24b.

Further upper peens 28b0 and lower peens 28bu are arranged opposite the peens 27b and along the inner side of the supporting

members

25b and 26b. The slot 22b extends also between these upper and lower peens. Further, the supporting

members

25b and 26b of the two

counterholding jaws

8b and 9b are provided with spring

biased balls

29b and 30b for holding and guiding the template 21b.

The stroke or rather the length of the stroke of the hammer head 7b as indicated by the double arrow in FIG. 6 is in this example embodiment also somewhat smaller than the spacing between the peen 31b and the peens 32b0, 32bu. This feature accomplishes that the steel strip stock 5b is placed by the strokes between the peens 2712 or 28b0 or 28bu of the

counterholding jaws

8b and 9b.

By reversing the direction of the effective stroke movement, it is possible to shape any desired punching knife shape, whereby simultaneously a direct adaptation of the knife being shaped to the shape of the template 2lb is possible since the latter is guided directly up to the stroke range.

The exact observation of the shaping at the point of impact is difficult due to the upper legs 23b of the

counterholding jaws

8b and 9b. For this purpose there is provided according to a further embodiment of the invention shown in FIG. 7 a viewing opening 330 or 34c so that the operator may view the impact area. The viewing opening 330, 340 is formed by at least partially displacing the upper leg 23: relative to the peens 27c and 286. This feature with displaced

counterholding jaws

8c and 9c asshown in FIG. 7 simplifies or facilitates the operation of the present apparatus.

FIG. 8 illustrates the supporting structure for the turntable 2 and the drive means for the hammer head 7. The turntable 2 is rotatably supported by balls 36 which in turn are located in a supporting ring structure 7. The balls 36 are preferably evenly distributed about the circumference of the ring structure 37 which in turn rests on the machine frame. The turntable 2 includes a table plate 39 which rests on an inner shoulder of a supporting collar 38 having a lower flange portion resting on the balls 36. The flange portion of the collar 38 is surrounded by a skirt reaching over the supporting ring 37. The turntable plate 39 is provided at its center with a guide slot 40 through which the hammer head 7 and the hammer drive means extend.

The drive arrangement for the hammer head 7 comprises an electric motor 41 which is secured to the lower surface of the table plate 39 by means of a slide carrier 42 held by guide members 55 forming a prism guide for the slide carrier 42. In this mmanner the entire hammer means with the respective drive means are adjustable in their position back and forth in a direction extending perpendicularly into the plane of the drawing and perpendicularly to the rotational axis of the tumtable 2. The positioning may be accomplished, for example, by well known piston cylinder means not shown in FIG. 8 for simplicitys sake. However, such piston cylinder means could be connected between the guides 55 on the one hand, and the flange between the motor 41 and the slide carrier 42.

The drive shaft 43 of the drive motor 41 has attached thereto an eccentric cam 44 which reaches into a cross groove 45 of an intermediate member 46 of the ham mer means. Thus, the rotation of the shaft 43 reciprocates the hammer head 7 because the intermediate member 46 slides back and forth in the groove or slot 40 whereby it is guided by respective guide means in the table 39 and whereby it is movably confined inside the table 39 by the slide carrier 42, as best seen in FIG. 8. In order to reduce or minimize friction between the eccenter cam 44 and the walls of the cross groove 45 a ring 47 of plastics material may be provided as shown.

The shaping of the steel strip stock 5 is accomplished according to the invention by two motions superimposed on each other. One motion is the stroke motion of the hammer head 7 accomplished by the motor drive means 41, 43, 44, 45, 46, and 47. The second motion is the feed advance motion of the slide carrier 42 accomplished by, for example, hydraulic piston cylinder means arranged as described above, however, not shown for simplicitys sake. As stated, by these hydraulic means, the entire hammer means 46 may be moved back and forth in the direction of the guide slot 40.

A support plate 50 extending in the same plane as the turntable 2 supports the portion of the steel strip stock extending outside the turntable 2. This supporting plate 50 carries as shown in the upper left hand corner of FIG. 8, the guide rollers 3 and 4 constituting the means for positioning the strip material 5. These guide rollers 3 and 4 may, for example, be driven by a gear train 51, 52 actuated by a motor 53 attached to the plate 50 by respective brackets.

FIGS. 9 and illustrate a further embodiment according to the invention and showing a bending apparatus 60 including holding means for a template 61. The

holding means comprise a freely movable outrigger 62 including an arm 63 which is freely rotatable by bearing means 66 supported in the frame structure 67. Preferably the outrigger 62 includes two

arms

63, 64 pivotally connected to each other by means of a joint 65 which is preferably especially easy to operate but which has as little play as possible. The bearing means 66 for the outrigger arm 63 is located in the frame structure 67 in such a manner that the template 61 will always assume a parallel position relative to the turntable 68 in any position of the outrigger 62.

The free end of the arm 64 opposite the joint 65 has attached thereto in a rotatable manner a supporting means 69 preferably including carrier elements 70 for the template 61. The carrier elements 70 may for example be suction cups which hold the template 61 by means of reduced pressure. For this purpose the suction cups 70 are connected through

conduits

71, 72 to a vacuum pump 73. The

conduits

71, 72 may for example be connected in a suitable manner to the outrigger 62 and pass down to the pump 73 which may be attached to the frame structure 67. The suction cups 70 hold the template 61 securely and prevent its displacement if the pump 73 produces the necessary pressure difference relative to the atmospheric pressure. The flat template 61 is adjustably held above the turntable 68 and above the hammer means 78 as best seen in FIG. 10.

When forming a particular shape in accordance with the template 61 the leading end of the steel strip stock 74 is secured to the template by suitable clamping means 75 known as such. The operator then controls the position of the slide carrier 42 as shown in FIG. 8 in such a manner that the hammer head 77 performs idle strokes so as not to hit the strip stock 74, whereby a straight portion 76 of the final shape is formed. As soon as a bend or a corner is to be formed in accordance with the shape of the template, the operator advances the slide carrier 42 so that the entire hammer means 78 are displaced and so that one or the other peen of the hammer head 77 becomes effective. As soon as the bent portion has been completed and if such bent portion is followed by another straight portion, the slide carrier 42 is again adjusted in its position so that idle strokes are performed. The feed advance mechanism 79 simultaneously advances the strip stock 74 by means of a drive roller and a counter or supporting roller 81. In this instance, that is, when the hammer head 77 performs idle stroke, the feed advance may be faster than when the hammer head 77 performs effective bending strokes.

It is to be understood that the adjustment of the slide carrier 42 may be accomplished instead of by the operator, by an electrodash optical control mechanism which as such is well known in the art and by means of which the entire hammer means 78 would be controlled automatically. In this fashion the production of the steel strip knives would be fully automatic. Such a control mechanism is not shown in FIGS. 9 and 10 for claritys sake.

Since during the shaping of the steel strip stock by the hammer means 78, the strip 74 is stopped for short durations at the time when the hammer head 77 hits the strip 74. To accommodate nevertheless a continuous feed advance for the strip, the feed advance mechanism 79 for moving the strip 74 relative to the hammer means 78 is supported by resiliently yielding means,

whereby the mechanism is also shiftable back and forth along the feed advance direction of the strip 74. The feed advance mechanism comprises two rollers 80 and 81 of which the roller 80 is driven by a motor 82. The motor and the rollers are secured to a carrier block 83 which is shiftably and yieldingly supported in the frame structure 67 which also supports the turntable 68. Referring specifically to FIGS. 9 and 10, the block 83 is supported between two

struts

84 and 85 which carry respective bearing means 86 and 87. Supporting bolts 88 interconnect the bearing means 86 and 87 from strut to strut. These bolts connect the block 83 to the bearing means, for example, in that they extend through respective holes of the block 83 so that the block is freely slidable back and forth along the direction of feed advance of the strip 74. On the other hand the bolts may also be rigidly connected to the block 83 and slide back and forth in respective holes of the bearing means 86 and 87. In any event resilient means such as spring elements 89 or resilient buffer means are inserted between the block and the respective bearing means 86 and 87. These resilient means support the block 83 in both directions. Preferably, the bolts 88 are arranged inside of the springs 89 as shown in FIG. 9.

The feed advance mechanism 79 due to the above described supporting structure according to the invention is capable to continuously feed the strip 74 to the hammer means 78 even at the times when the hammer head 77 briefly stops the strip 74 when it hits the strip. The entire block 83 with the drive roller 80 performs at this instance a movement away from the hammer head 77 that is in a direction opposite to the normal feed advance. By this feature the continuous feed advance of the strip 74 is assured without interfering with the operation of the hammer means. As soon as the hammer head 77 releases the strip 74 the resilient means or springs 89 shift the entire block 83 again in the feed advance direction until the next hammer stroke takes place, whereby the same cycle as described above is repeated.

Between the hammer means 78 and the feed advance mechanism on the block 83 there are arranged two

guide rollers

90 and 91 which assure the exact guiding of the strip stock 74.

Although the invention has been described with reference to specific example embodiments, it is to be understood, that it is intended to cover all modifications and equivalents within the scope of the appended claims.

What is claimed is:

l. A bending apparatus for bending strip material into shapes, comprising hammer means including a hammer head, drive means operatively connected to said hammer means for reciprocating said hammer means with a given stroke, a turntable having a rotational axis, means for freely rotatably supporting said turntable, counterholding jaw means on said turntable, said hammer head being arranged for cooperation with said counterholding jaw means, and means for positioning said strip material at a point outside said turntable.

2. The apparatus according to claim 1, wherein said positioning means comprise two rollers which hold the strip material therebetween.

3. The apparatus according to claim 2, further comprising drive menas for said positioning rollers,

whereby the strip material is simultaneously advanced toward said turntable.

4. The apparatus according to claim 1, wherein said hammer head is reciprocated along a path extending perpendicularly to said rotational axis of said turntable.

5. The apparatus according to claim 1, wherein said hammer head comprises two peens.

6. The apparatus according to claim 5, wherein said hammer head has a recess intermediate its ends, said recess having a length longer than said given stroke.

7. The apparatus according to claim 6, wherein said two peens face each other across said recess whereby the peens face in their respective stroke direction.

8. The apparatus according to claim 5, wherein said hammer head comprises two outer ends opposite said peens, said outer ends comprising a cutting edge, said counterholding jaw means comprising a strip receiving groove.

9. The apparatus according to claim 8, wherein said receiving grooves of adjacent counterholding jaw means are aligned with each other, said aligned grooves extending substantially perpendicularly to the path of reciprocation of said hammer head.

10. The apparatus according to claim 5, wherein said two peens form opposite ends of the hammer head, said two peens facing in opposite directions.

11. The apparatus according to claim 1, wherein said jaw means comprise two jaws arranged in parallel to each other and sufficiently spaced from each other to receive the hammer head for reciprocation therebetween.

12. The apparatus according to claim 11, wherein each of said jaws comprise a peen facing toward said hammer head.

13. The apparatus according to claim I, wherein said jaw means comprise two pairs of jaws whereby the jaws of the same pair are arranged in parallel to each other and the jaws of different pairs are arranged in longitudinal alignment with each other, said jaws being spaced from each other sufficiently to receive the hammer head therebetween and to allow for said stroke.

14. The apparatus according to claim 11, wherein each of said jaws comprises a peen whereby the peens of opposite jaws face each other.

15. The apparatus according to claim 1, further comprising means for adjustably and removably attaching said jaw means to said turntable.

16. The apparatus according to claim 1, further comprising a slide carrier for said hammer means and for said hammer drive means, guide means attached to said turntable for supporting said slide carrier, and adjustment means for adjusting the position of said slide carrier in the direction of the motions of said stroke.

17. The apparatus according to claim 1, wherein said hammer head and said jaw means comprise a common lateral slot for receiving a template whereby the shape of the strip material may be conformed to the shape of said template.

18. The apparatus according to claim 17, wherein said hammer head and said jaw means have substantially a C-shape whereby said slot is formed between free ends of the C-shape and whereby the strip material passes through said C-shape.

19. The apparatus according to claim 18, wherein said hammer head and said jaw means each comprise respective peens, whereby the peens are arranged on the inside of said C-shape so that respective peens face each other.

20. The apparatus according to claim 18, wherein said C-shape of the jaw means comprises an upper horizontal leg, said leg having see through means for revealing the respective peens.

21. The apparatus according to claim 20, wherein said upper horizontal leg is laterally displaced to provide said see through means.

22. The apparatus according to claim 1, further comprising template holding means for locating a template relative to said counterholding jaw means and relative to said hammer head, said template holding means comprising an outrigger having a free end.

23. The apparatus according to claim 22, wherein said outrigger comprises arm means and bearing means for said arm means for freely rotating said arm means.

24. The apparatus according to claim 23, wherein said arm means comprise two arm sections and joint means for rotatably connecting said arm sections to each other.

25. The apparatus according to claim 22, wherein said template holding means comprise a template gripping device attached to said free end of the outrigger.

26. The apparatus according to claim 22, wherein said template holding means comprise suction means.

27. The apparatus according to claim 1, further comprising feed advance means for said strip material, said feed advance means including a driven roller and a counter roller arranged on opposite sides of the strip material, and means for shiftably and yieldably supporting said driven roller and said counter roller.

28. The apparatus according to claim 27, wherein said supporting means comprise a block for carrying said driven roller and said counter roller, said apparatus further comprising drive means for said driven roller, said drive means also being attached to said carrying block.

29. The apparatus according to claim 28, further comprising a frame structure, guide means in said frame structure for said carrying block, and resilient means between said frame structure and said block for shiftably and yieldably moving said block back and forth along said guide means.

30. The apparatus according to claim I, further comprising a slide carrier for said hammer means and for said hammer drive means, guide means attached to said turntable for supporting said slide carrier, and adjustment means for adjusting the position of said slide carrier in the directions of motions of said stroke, sensing means, and means operatively connected to said adjustment means and responsive to said sensing means for adjusting the position of said slide carrier relative to the center of said turntable.

31. A bending apparatus for bending strip material into shapes, said bending apparatus comprising a hammer head, a pair of counter holding jaw means, said jaw means comprising two pairs of jaws whereby the jaws of the same pair are arranged in parallel with each other and jaws of different pairs are arranged in longitudinal alignment with each other and facing each other, said jaws being spaced from each other sufficiently r0 receive said hammer means therebetween, said hammer means being mounted for reciprocating movement between said jaws.

32. A bending apparatus for bending strip material into shapes, comprising a first pair of parallel spaced apart jaws each having a work surface on one end, a second pair of parallel spaced apart jaws each having a work surface on one end, said jaws being fixedly mounted with respect to each other, with one jaw of each pair aligned with one jaw of the other pair, and aligned jaws having work surfaces directed toward each other, hammer means slidably mounted in the spaces between said jaws and having a pair of peens extending in opposite directions parallel to said jaws, and means for reciprocating said hammer means with respect to said jaws, whereby a selected one of said peens cooperates with the pair of jaws having work surfaces facing in the direction opposite said one peen to bend a strip material between said one peen and said last mentioned jaws.

Claims

1. A bending apparatus for bending strip material into shapes, comprising hammer means including a hammer head, drive means operatively connected to said hammer means for reciprocating said hammer means with a given stroke, a turntable having a rotational axis, means for freely rotatably supporting said turntable, counterholding jaw means on said turntable, said hammer head being arranged for cooperation with said counterholding jaw means, and means for positioning said strip material at a point outside said turntable.

3. The apparatus according to claim 2, further comprising drive menas for said positioning rollers, whereby the strip material is simultaneously advanced toward said turntable.

13. The apparatus according to claim 1, wherein said jaw means comprise two pairs of jaws whereby the jaws of the same pair are arranged in parallel to each other and the jaws of different pairs are arranged in longitudinal alignment with each other, said jaws being spaced from each other sufficiently to receive the hammer head therebetween and to allow for said stroke.

30. The apparatus according to claim 1, further comprising a slide carrier for said hammer means and for said hammer drive means, guide means attached to said turntable for supporting said slide carrier, and adjustment means for adjusting the position of said slide carrier in the directions of motions of said stroke, sensing means, and means operatively connected to said adjustment means and responsive to said sensing means for adjusting the position of said slide carrier relative to the center of said turntable.

31. A bending apparatus for bending strip material into shapes, said bending apparatus comprising a hammer head, a pair of counter holding jaw means, said jaw means comprising two pairs of jaws whereby the jaws of the same pair are arranged in parallel with each other and jaws of different pairs are arranged in longitudinal alignment with each other and facing each other, said jaws being spaced from each other sufficiently ro receive said hammer means therebetween, said hammer means being mounted for reciprocating movement between said jaws.