US2341178A - Metal tubing bending machine - Google Patents

Description

F. L. DUER METAL TUBING BENDING MACHINE Feb. 8, 1944.

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Feb. 8, 1944. F. L. DUER 2,341,178

METAL TUBING BENDING MACHINE Filed Dec. 6, 1941 :s'sheets-sheet 2 INV ENT OR.

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F. L. DUER 2,341,178

METAL TUBING BENDING MACHINE Filed Dec. 6, 1941 3 Sheets-Sheet 3 INVENT OR.

Patented Feb. 8, 1944 UNITED STATES PATENT OFFICE 2,341,178 METAL TUBING BENmNG MACHINE Frederick L. Duer, Chicago, 111. Application December 6, 1941, Serial 1V0. 421,924

2 Claims. (01. 153-40) L This invention relates to improvements in metal tubing bending machines, such as described and claimed in my co-pending application for Letters Patent, Serial No. 399,301, filed June 23, 1941, and more particularly, the invention has reference to an improved jig for machines of such character, having for an object to provide a jig especially advantageous for use in connection with those types of bending machines wherein a succession of annular bends of pre-determined degrees are required to be made in tubular, strip or similar stock during the formation of products, such for example, as chair frames, table frames, legs, supporting stands, etc.

It is also an object of the invention to provide a jig for metal bending machines having stock guide means thereon so positioned that when the same are individually employed in' association with that stock to be bent by the machine, the stock will be arranged in relation to the metal bending form of the machine so as to be bent at a pre-determined point, hence, insuring accurate and proper formation of an ultimately finished product and moreover, accurate reproduction of similar products.

Yet another object of the invention is to provide a jig of the stated character which is so constructed that by its use in connection with a. metal bending machine, the operating .time normally required for the making of a multiplicity of accurate bends in material or stock will be greatly reduced, hence, afiording increased production tubing in position with respect to a portion of the skilled in the art to which it appertains, I have in the accompanying drawings and the detailed description based thereupon, set out one embodiment of my invention. I

In the drawings: Figure 1 isa top plan view of a metal tubing bending machine equipped with my improved jig.

Figure 2 is a side elevation of the same,

Figure 3 is a combined schematic and perspecjig for making a fifth bend therein.

Figure 'l is a similar view illustrating the thus far bent metal tubing in position, with respect to a portion of the jig, for the making of a sixth bend therein.

Figure 8 is a like view showing the metal tubing in position with respect to the machine bending form and a portion of the improved jig, for the making of a seventh bend therein.

Figure 9 is a corresponding view wherein the metal tubing stock is in position with respect to the machine bending form and a portion of the jig, for the making of the 8th bending therein, and

Figure 10 is'a perspective view of a completed chair form produced or bent upon the improved jig equipped machine in accordance with the successive steps of bending illustrated by the Figures 3 to 9, inclusive.

Having more particular reference to the drawings, in connection with which like characters of reference will designate corresponding parts throughout, the improved jig is particularly advantageous for use in connection with that type of metal bending machine described and claimed in my co-pending application for patent, aforesaid, which machine includes a horizontal bed I mounted on a suitable support (not shown) having a secondary bed 2 fixed to its normally forward end shown in Figures 1 and 2 of the accompanying drawings. A rotatable bending form 3 is positioned on the upper side of the secondary bed 2, in which a vertical shaft 4 is journaled and has a gear 5 on its lower end. Rotary motion is selectively transmittable to the gear 5 through a horizontal rack bar 6 supported by the beds 1 and 2, thesteeth of said barmeshing with those of the gear To secure tubing or other stock to be bent by the machine, a work clamp l is mounted on the upper side of the secondary bed 2 in suitable relation to the bending form 3. By engaging a length of tubing in the clamp at an appropriate point and adjacent the bending form, it will be seen that with rotation of said form, said tubing will be bent thereby to the desired angular degree.

In order that the tubing or other stock to be bent upon the machinemay be caused to be bent or successively bent at pre-deterznined points throughout its length, whereby to effect an accurate and satisfactory product, I provide my 1 proved jig. Prefatorially, it may be stated that this improved jig may be adjusted or set to facilitate making of a multiplicity of predetermined bends in stock at various points throughout its length, and when correctly employed, will insure faithful reproduction or replica production of products by the equipped machine.

The jig, in general, comprises a plurality of guides and stops or rests with which the stock to be bent during a particular production job is en gaged at certain predetermined points thereon, whereupon the bending operations of an equipped machine are efiected, resulting in a product which is capable of detailed accurate reproduction in all other subsequently produced pieces. The relative arrangement of the guides and stops is such that angular bends of desired degrees will be made in the stock material at predetermined points throughout its length and also, that such bends may be effected in relatively different planes so that complete formation of a product may be accomplished by a single machine through a continuous succession of predetermined machine bending operations.

Fixedly connected at one end to an appropriate upper portion of the secondary bed 2 through the medium of screws or other suitable fastening means 8 is a supporting arm 9. Slidably received upon and disposed longitudinally of the arm 9 in juxtaposed relation are a pair of bars in and H having relatively upstanding and right angularly disposed fingers ill and ii fixed on their normally inner end portions. Each of the bars is longitudinally slotted, as at I2 and [3 whereby to receive locking screws i4 and I5 therethrough. The locking screws are turned into engagement with appropriate portions of the arm 9 and in consequence, serve to confine the paths of longitudinal sliding movement of their respective bars I and II. Adjusting screws it are engaged through screw threaded openings formed in the fingers ill and II and have their heads in bearing arrangement upon adjacent portions of the secondary bed 2. Thus, by turning the adjusting screws l6,suitable longitudinal sliding adjustment of their respective bars l0 and II upon the arm '9 will be effected, whereupon said bars may be'locked in their respectively adjusted positions by tightening of the screws l4 and I5. An upstanding guide pin I1 is fixedly carried upon the normally outer end of the bar 1- and the corresponding end of the bar II is formed longitudinal or horizontal adjustability with respect thereto. An angle arm 26 is secured to the upper end of the rest 24 inwardly of its outer end and at substantially right angles thereto, while an adjustable stop bolt 21 is engaged through the upper part of said rest 24 and the adjacent portion of the angle arm 26. In this connection, it will be noted that the adjustable stop bolt 21 is arranged in substantially parallelism to the right angularly disposed portion of the arm 26 and that its free end is inwardly placed with relation to the outer end of said arm.

A second horizontally arranged supporting arm 28 is rigidly connected to an appropriate portion .of that side of the secondary bed 2 in proximity to the point of connection of the arm 20 therewith. Said arm 28, however, is disposed at substantially right angles to the arm 20 and carries a standard 28' on its outer end, which, in turn, carries a rigid horizontally arranged and longitudinally disposed arm 28, the forward end of which is provided with a rigid standard 28 carwith a transversely disposed extension I8 on outwardly beyond the forward end of the bed I to a point beyond the arm 9 and, as will be noted upon reference-to FigureZ of the accompanying drawings, is arrang'edin a plane below'that in which said arm} s a'rranged. A facing plate 22 is positionedlononeiside of the. outer portion ofthe arm' 20 provides a slidable bearing for rying an oblique and forwardly disposed supporting arm 28 upon its outer end. A facing plate 29, corresponding to the facing plate 22, is fixed to one side of the free end of the supporting arm 28 and has a horizontal longitudinally slotted finger 30 slidably connected thereto through the medium of locking screws 3| passed through the slot of said finger into engagement with appropriate screw threaded openings in the facing plate 29. Secured to the outer side and forward end of the longitudinally slotted finger is a horizontally arranged angle arm 32, corresponding to the angle arm 26, while an adjustable stop bolt 33, arranged in parallelism to the arm 32, and

corresponding to the bolt 21, is also engaged with said finger 30; the outer end of such stop bolt being spaced inwardly with relation to its adjacent angle arm 32, as clearly shown in Figure 1 of the accompanying drawings.

It is to be noted that the relative arrangement of the angle arms 25 and 32 and their respective adjacent adjustable stop bolts 21 and 33 is such that they are disposed in substantially vertical or perpendicular alignment, the latter above the former, hence, that but one (the arm 32, the stop bolt 33 and its finger 30) is shown in Figure 1 of the drawings;

The horizontal arm 28 is provided upon its normally inner side with a fixedly arranged facing plate 34 adjacent which a slotted finger 35 is positioned and is adapted to have adjustable sliding movement with respect thereto through the medium of adjusting or looking screws 36 engaged through the slot of said finger 35 and in appropriate screw threaded openings formed in the facing plate 34. The outer or normally forward end of the finger 35 is shouldered as at 31 and carries a right angularly disposed vertical portion 38 to which a longitudinally slotted arm 39 is slidably connected by passing looking or adupon reference toFigures 1 and 2 of the accome the longitudinallyslotted finger 23 carrying an upright-rest uponits outer end. Connecting or looking screws. 2 5 are engaged through the ioni u inal ot-oi he' a r H d in appropria screw threaded 1 openings formed in the facing pla 22;; huar vi n's for s p rti co panying drawings, extends for a distance outwardly beyond the shouldered portionl'l' of the finger 35. The arrangement ofthe finger 35 on the horizontal arm 28 is such that the'upperex- 'tremity of the arm as and its laterally extending lip or rest 41 are arranged ins-horizontal plane v tionrofv tattleplate and also, for 7'5 corresponding to; that mwhich .the rotatable bending form 3 is arranged. as will be observed upon reference to Figure 2 of the drawings.

In order that tubing T engaged with the supporting arm 3, in the manner shown in dotted lines in Figure 1 of the drawings, will be efl'ectually retained in the Proper horizontal plane,

The bearing plate 43, in turn, receives a vertically adjustable rest 44 adjacent its outer side, said rest being in form of a sheet-like metal plate having a horizontally and rearwardly extendedsupporting finger 45 formed thereon. Vertical adjustment of the plate 44 is effected by engaging screws 46 through vertical slots 41 formed in said plate and into engagement with appropriately formed screw threaded openings in the plate 43. Thus, it will be understood that the rest 44 may be vertically adjusted to support the outer end of tubing engaging the same in the desired position or horizontal plane.

In operation of my improved jig, and assuming the same to be installed upon that type, of bending machine partially shown in the accompanying drawings and heretofore generally described, the component parts of the jig are preadjusted to proper positions for the particular bending job to be performed. In the instant embodiment of the invention, the jig has been set for usage in the production of a type of tubular metal chair frame such as shown inFigure 10 and identified in its entirety by the reference character 0. Metal tubing of the required diameter or size and of the proper length, is engaged, at a predetermined point throughout its length, with the metal bending form 3. The'reupon, it is secured by the work clamp l and the bending form 3 is rotated through the gearing connected thereto so as to form the first bend-a right angular bend 48-in the tubing. With the first bend thus made, the tubing is disengaged from the work clamp 1 and from the bending form 3. It is moved outwardly with respect to the machine until the right angular bend 48 is engaged aboutv and adjacent the guide finger [1. When so engaged, it will be seen that the right angular outer leg portion of the tubing T is supported in the proper horizontal plane by the adjacent portion of the arm 9 and by the normally innerportion of the upper edge or margin of the adj d r t M, in the manner shown in Figure 3. At such time, the inner leg of the metal tubing T will be properly arranged adjacent the near side of the bending form. 3 and will be secured through the work clamp l. The bending form 3 is now r0- tated to the proper degree, thus forming a second right angular bend in the tubing, indicated by the numeral 49, in the Figure 4, The bent tubing T is now disengaged from the work clamp I and the bending form 3 and readjusted with respect thereto, whereupon it is reclamped by the work clamp I in that position illustrated by Figure 4, which constitutes the position of the tubing for making the third bend therein. In order that such third bend may be accurately effected in the tubing and in that side or leg of the same engaged adjacent the bending form,3, the looped or right angularly formed end portion constituted by the bends 48 and 43, is moved until the outer portion, i. e., the bend 43, is engaged over the angle arm 32 carried by the slottedfinger 33. The adjacent portion of the tubing is brought into firm contact with the adjacent end of the previously adjusted stop bolt 33 so as to assure the making of such third bend in the proper plane, which, as will be noted upon reference to the Figure 3, is to be effected 111 8 plane at right Y angles to that at which the bends 43 and 43 were made. At this time, the bending form 3 is 1'0- tated so as to eflect a degree or right angular bend it in the adjacent portion of the metal tubing T. Following the making of the third bend in the tubing, the thus far formed product is again disengaged from the work clamp 1 and rearranged with respect to the metal bending form 3. The portion provided with the bends 43, f

43 and I3 is arranged in a substantially vertical plane, as shown in Figure 5, with the outer end of the same supported upon an appropriate portion of the upper edge of the vertically adjusted rest 44 and the bend 50 engaged about the adjacent and previously adjusted guide finger l3. Thereupon, the metal bending form is rotated to form a fourth and 90 degree or right angular bend il in the adjacent portion or the tubing,

by reason of positioning of the work piece in course of production upon the jig, that the free portion of the tubing T beyond the bend will be in absolute parallelism to the corresponding side of the previously bent tubing, to constitute one side of the seat supporting portion of the chair frame being made. To constitute one side of the back of the tubular metal chairframe, it now becomes necessary to effect a fifth bend in that side of the tubing formed with the bends 50 and 5|. Accordingly, said side of the tubing is readjusted with respect to the work clamp l and the metal bending form 3 to that position shown in Figure 6. a That portion of the tubing adjacent the bend to is engaged with and supported upon the previously adjusted rest 4|, and particularly, the lip portion of the same in contact with the shouldered portion 31 on the outer or normally forward end of the finger 35. When thus arranged, the piece being produced will be so positioned that as the metal bending form 3 is again rotated to the desired degree, a less than right angular bend 52 will be eifected in the adjacent portion of the tubing so that the now free or outer end of the tubing constitutes one side of a slightly inclined back for the chair frame.

At this point, it should be explained that one complete side of the chair frame has now been produced and the following operation or bending of the tubing T is effected to produce the opposite side of the chair frame. The piece is reversed in position and the remainingor unbent side of the length of tubing is engaged with the work clamp I and the metal bending form 3 in the manner shown in Figure 7 of the accompanying drawings. In such position, it will be observed that the basal portion of the chair frame, 1. e., that portion having the bends 43, 43 and 50 formed therein, is arranged in a vertical plane, its outer end being engaged over and about the angle arm 26 of the upright rest 24 and in abutting engagement with the adjacent or free end of the previously adjusted stop bolt 21. With securing of the tubing adjacent the bending form 3 by the work clamp 1, said bending form is now rotated to form a 90 degree or right angular bend 53 therein. With forming of the right angular bend 53, the work piece is vertically adjustable .rest '44 in the manner shown in Figure 8; also, that portion of the tubing having the bend 53' formed therein is engaged about and'adja'cent the guide finger I! of the bar II. The work clamp is engaged with the adjacent portion or side of the work piece and the bending form is rotated whereby to effect a right angular bend' 54 therein. At this point, it will be noted that that portion of the tubing outwardly of the bend 54 will be arranged in parallelism to the corresponding side of the basal portion of the chair frame, and thus, will constitute the opposite side of the chair frame seat receiving portion. Following its release from the work clamp i, the work piece is readjusted with respect to the jig so that the bend 58 is received upon the rest 4! of the arm 89 adjacent the shouldered portion 31 of the finger 35 in the manner illustrated in Figure 9 of the accompanying drawings. The work clamp i is now re-engaged with the adjacent portion of the tubing T of the work piec and the metal bending form 3 is rotated to effect a slightly less then right angular bend 55 in the tubing, thereby constituting the inclined opposite side of the chair frame back.

A chair frame made according to the above described operation, heretofore characterized by the reference character C (Figure 10) may now be provided with a suitable type of seat S and back B.

The construction and operation of my improved jig is such that the various bends and duplicating bends in the opposite or opposed portions of the chair and tubing stock will absolutely cor-,- respond and in consequence, will insure the production of a metal tubing chair frame whose opposite sides are replicas one of the other. Moreover, the construction of the improved jig and its operation is such that rapid reproduction of tubular metal chair frames may be effected by its usage with a resultant material lowering of production costs, including time, labor, etc.

Whereas I have herein illustrated and described my improved jig as adapted for usage in the forming or production of tubular metal chair frames, it is, of course, to be fully understood that such Jig may be as advantageously employed in guiding the formation of various constructions or products, such for example, as bed frames, bench frames, table frames, etc. When such adaptations of the jig are eflected, the various guide fingers, rests, and like elements of construction are, as will be understood, so relatively adjusted to pre-determined positions as to insure accurate and proper placement of bend formations.

I claim:

1. A jig for bending machines, comprising an arm secured to and extending forwardly of the machine, longitudinally adjustable bars on said arm, guide means carried by each of said bars, an adjustable rest supported from and laterally of said arm, substantially opposed supporting arms secured to and extending forwardly of the machine arranged in planes different from that of the first arm, adjustable guide means on each of said supporting arms, adjustable stop means on the supporting arms cooperatively associated with said last mentioned guide means, and a 7 second adjustable rest supported on a portion of one of said supporting arms in substantially laterally opposed relation to said first rest.

2. A jig for bending machines, comprising an arm secured to and extending beyond the work receiving end of the machine, adjustable bodies on said arm, guide means on said adjustable bodies, adjustable supporting means carried by said arm and disposed laterally thereof, supporting arm respectively secured to and extending forwardly of the machine work receiving end above and below the first mentioned arm, guide ineanson each said supporting arm, stop means on the supporting arms co-Operatively associated with the last mentioned guide means, and a second adjustable means supported on a portion of one of said supporting arms and arranged in substantially-laterally opposed relation to said first adjustable means.

FREDERICK L. DUER.

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