US1420042A - Machine and method for forming and bending tubes - Google Patents

Description

F. KRITZ.

MACHINE AND METHOD FOR FORMING AND SENDING TUBES.

I APPLICATION FILED DEC-11,1920.

Patented June 20, 1922.

4 SHEETS SHEET I.

F. KRITZ.

MACHINE AND METHOD FOR FORMING AND SENDING TUBES. APPLICATION FILED DEC. II. 1920.

1 AQQQQQ. Patented June 20, 1922.

4 SHEETSSHEET 2- "fig? INVENTOR.

A TTORNEY.

F. KRITZ.

I MACHINE AND METHOD FOR FORMING AND BENDING TUBES.

APPLICATION FILED DEC. 11, 1920.

j], AQQQOQZ Patented June 20, 1922 4 SHEETS-SHEET 3.

..LN V EN TOR.

A TTORNE Y.

F. KRITZ.

MACHINE AND METHOD FOR FORMING AND BENDING TUBES.

. APPLICATION FILED 012cm, 1920. LQQQQQL-QQ Patented June 20, 1922.

4 SHEETS-SHEET 4.

I N V EN TOR.

A TTORNEY.

tartan stares PATENT @FFHCE.

FRANK KRITZ, OF DETROIT, MICHIGAN.

Specification of Letters Patent.

Patented June -20, 1922.

Application filed December 11, 1920. Serial No. 429,914.

T all whom it'may concern: I Be it known that I, FRANIcKRrr a citizen of the United States, residmg at Detrolt,

- in the county of Wayne and State of Michigan have invented certain new. and useful Improvements in Machines and Methods for Forming and Bending Tubes. of which the following is a specification.

This invention relates to tube forming and bending machines. It is the object of this inventionto provide a machine which will both form a piece of flat ribbon stock into a tube or moulding and simultaneously bend the same. One of the main objects of the machine is to form tubing that may be used to construct the rims of steering wheels. but obviously the invention is capable of a wider application. The machine is capable of making a coil of tubing or moulding from a flat ribbon of metal or it can be used to make short lengths of tubing or moulding into substantially circular form. lVbere a long coil of tubing or moulding is made the operation is substantially automatic. the strip of flat stock being run through the various bending and shaping devices and emerging at the final end as a completely formed coil of tubing or moulding. The coil may then be cut up into short lengths permitting the forming of circular rims.

Where relatively short lengths of tube or moulding are formed and bent the operation is substantially. the same but the action is not automatic. The product has to be taken from one device to the other by hand. This will more fully appear when the specific construction is understood.

In the drawings,

Fig. 1 is a front elevation of the machine showing, however, only the parts above the bed and with the guiding blocks and supporting parts therefor removed.

Fig. 2 is an end elevation of the machine.

Fig. 3 is a fragmentary plan view of the machine.

Fig. 4 is a fragmentary front elevation showing the stock passing through the rolls. This is taken at the extreme right of Fig. 1.

Fig. 5 isa perspective of the guide block.

Figs. 1. 1". 1. 1 and 1 are sections of the work taken after it has passed through rolls 11, 22, 33. 4-4. and 5+5. respectively.

This machine is capable of use to make either tubing or moulding. I have illustrated a machine that is adapted to making tubing and consequently throughout the specification specific reference may be made to tubing but I wish it understood that the machine has a broader application than simple tubing and is not restricted to this alone.

(1 represents the bed of the machine which is supported upon a sub-bed b by means of the large I-beams c. This sub-bed b is supported upon legs (i. (I. Upon the bed a are supported a plurality of standards 0 which journal the single lower shaft 7' and the several upper shafts 9. These standards are bolted to the bed a. It is necessary to make the upper shaft separate because otherwise some of the upper rolls. because of larger diameter. would run faster at the middle of their peripheries than their companion lower rolls. This would not be permissible in pulling on a single continuous piece of stock that runs through all the rolls. 'lhese upper shafts 1 are driven by a train of gears it from the lower shaft 7' and consequently can have the proper gear ratio to give each upper roll its proper speed. A large gear 1? on the end of the long lower shaft f is driven by a driving pinion which very materially reduces the speed.

The rolls 1. 1 are secured on the upper and lower shafts byu-ollars is secured thereto by set screws. The stock is drawn off from a roll 7 of flat ribbon steel or of other suitable material. This runs down through a chute In between the staggered pins 11 and over the maple block 0 which is detailed in perspective in Fig. 5. This block 0 is formed to gradually taper toward the cross-sectional shape of the rods and is held in a saddle p. which is a casting and which is guided to slide in the dove-tailed guide q. The hand screw 1' has one end secured rotatably in the saddle and is threaded through the upstanding lug s in the end of the dove-tailed guide 9. lt'will be seen that these dovetailed guides are simply castings with cap plates t bolted thereto. the castings being bolted to the bed of the machine by bolts u. By turning the hand wheel the saddle 1) may be advanced toward or away from the set of rolls 1. 1. thereby varying the diameter of the bend given the stock. as will presently be described.

The first set of rolls 1. 1 is calculated to give the stock a shaping o eration and in connection with the maple vlock 0 to also give it a longitudinal bending. The first i take successively smaller coils.

racks.

cross-sectional shaping is that shown bythe cross-sectional view Fig. 1 below the rolls 1, 1 in Fig. 1. It will there be apparent that the first shaping operation is to slightly concave the center of the cross section and slightly turn in the edges of the strip. At the same time the strip is bent into the circle or coil as shown at r (Fig. 2). This is accomplished because the guiding surface of the block 0 is-angularly offset with respect to y the perpendicular to a line through the axes of the'upper and lower rolls. In ordinary metal forming operations the stock is guided to the two rolls on a line substantially perpendicular to the line through the axes of the upper and lower rolls. vConsequently thereis little or no tendency of the metal to bend. It is my purpose to guide the stock to the rolls so as to produce a pronounced but gradual bending at the-same time, the cross-sectional shaping occurs. For this purpose, as already explained, I utilize the maple blocks which are superior to rolls for this purpose as the apex of the block can be brought up very closely to the point where the two rolls pinch the stock.

On the opposite side of the two rolls is located a slide a: which journals an idler roller bend still sharper and assume a coil of less diameter. It will be noted that in the second set of rolls no chutem is used or needed. When the stock comes out of the second set of rolls ithas the cross-sectional shape shown in Fig. 1". It will be seen that the lower roll of this set is concaved and the upper roll is sharply convex with two flanges at either end arranged to turn in the edges of. thestock, as shown in Fig. 1.

The same operation obtains in the third set of rolls designated 3, 3. The lower roll is concaved, the upper roll is even more convex than the upper roll of set #2, and the flanges form deep recesses between the flanges and the convex portion of the roll in which the edges of the work are turned over more, as will be apparent from the cross-sectional showing in Fig. 1. At the same time the main portion of the strip is being bent up more into V shape. In connection with this set of rolls is also utilized a guiding, block which serves to reduce the diameter of the coil, as will be evident from the position of the rack 16 onto which the coil is fed. The same operation occurs in connection with the rolls 4, 4 except that here the central convex portion is narrower than in the previous 3 This is carried in a dove-tailed guide-: in the same way that the saddle on the opposite side is, and the hand w 1861 10 and screw 11 permits thev adjustment of this slide back and forth. This roll is not intended to constrain the metal to bend but simplyas a supporting and guide roll for the strip asit comes in its bent from out of the rolls and block.

Above each set of rolls is located a rack supported on suitable posts 13. These racks are designated 14, 15, 16 and 17. Note that they are of successively less distance from the rolls and consequently are arranged to Fi.ch rack is. provided with upstanding pins 18 which keep the coils properly arranged on the As already explained, the stock passes along the chute m between thestaggered pins 91 into the first set of rolls and emerges therefrom having a cross-sectional form such as shown in Fig. 1*. At the same time, due to the angular ofi'setting of the guide block 0, the stock is caused to take the coil'form shown at e in Fig. 2. Similarly the second set of rolls and the flanges at the ends of the upper roll form deeper recesses at the sides of the central convex portion of the roll to further turn in the bead or the edges of the strip, and the main portion of the strip is formed into a more pronounced U shape, as shown in Fig. 1 inthe cross-sectional showing.

The fifth set of rolls 5, 5 are the final or closing rolls. The lower roll is a plain concaved roll and the upper roll is a plain concaved roll except for a slightly raised guiding fin 20. This roll serves to press the edge portions of the strip together and also press the edges down to form the complete bead, resulting in the tubular cross-sectional shape as shown in Fig. 1 This forms a very nice shape for the rim of a steering wheel of an automobile. The beading turns in the raw edges of the metal so it is perfectly smooth and the cross-sectional shape is suitable for comfortable operation of the wheel. However, obviously varying cross-sectional shapes can be made without departing from the invention.

The metal leaves the final set of rolls and runs onto a rack. 21, which is provided with spools 22 to keep properlyspaced the various convolutions of the coil.

The secret of the success of this form of operation is to gradually but coincidently shape the strip both longitudinally and cross-sectionally. If it were attempted to give the strip either its finalcross-sectional shape or its final longitudinal bending in one operation. it would so draw the metal that the same would wrinkle and the operacoil may be varied, but if a coil of co siderable variation from what the machine was built to manufacture is to be made, it is preferable to use a different set of blocks.

The operations heretofore defined with respect to a continuous strip of metal can be performed on short lengths of stock of substantially the length of the circumference of the intended rim. In such a case, however, each operation has to bee separate one and the coil is passed from one set of rolls to the other by hand. Obviously when the machine is so operated it is notnecessary that the rolls all be in line.

It will be obvious that rolls might be used in place of wooden blocks as the guiding surface is angularly removed from the perpendicular to the center line through the two rolls. However, a roll is not nearly as good for this purpose.

In some of the claims reference is 'made to the lower shaping rolls all being in line. ()bviously, by re-arrangement, it is possible to put all the upper rolls in line and the lower rolls in non-alignment. Hence this reference must be taken to be words of description and notof limitation.

Nhat I claim is: 1

Lin a machine for forming and shaping metal tube or moulding. the combination of a plurality of sets of section-shaping rolls, and means operating in conjunction with each set and coincidently therewith for bending the said tube or moulding longitudinally into coils of progressively smaller diameter after each pass.

2. In a machine for forming and bending a tube or moulding, the combination of a plurality of sets of section-shapmg rolls, and a plurality of members having guiding surfaces co-operating one with each set of saidshaping rolls and each guiding member placed at a greater angle to the perpendicular to the line normal to the axes of the shaping rolls for the purpose of causing the longitudinal curvature. of said tubing or moulding and reduction of the radius of such curvature.

3. lln a machine for forming and bending tubing or moulding. the combination of a plurality of sets of shaping rolls. and a plurality of guiding members one with each set of shaping rolls having guiding surfaces progressively further angularly removed from the perpendicular through the line normal to the axes of the rolls for giving the tubing a gradually increasing longitudinal curvature coincidently with its passing throu h the shaping rolls.

4. n a machine for forming and bending metal tubing or moulding. the combination of a plurality of sets of shapingrolls, and a plurality of guiding members one with each set of shaping rolls provided with guiding surfaces offset at progressively greater angles withrespect to the perpendicular to .the line normal to the axes of the rolls from the first set of rolls to the final set of rolls for gradually curving and diminishing the radius of the curvature of the tubing or moulding as the same is coincidently shaped into the proper cross section.

, 5. In a machine for forming and bending metal tubing or moulding, the combination of a plurality of pairs of shaping rolls, a guidin member in proximity with each pair of shaping rolls having a guiding surface angularly removed from the perpendicular to the line normal to the axes of the pairs of rolls, each guiding surfacebeing ofiset at a greater angle with respect to such perpendicular from the first set of rolls to the final set of rolls to reduce the radius of the coil. Y

6. In a machine for bending and forming metal tubing, the combination of a plurality of pairs of shaping rolls having surfaces arranged to take a flat piece of ribbon and. gradually curve the cross section of the same and turn in the edges and press the whole together to form a substantially closed tube having meeting edges, the said rolls comprising an initial pair of rolls, one having a concaved cross sectional surface and the other a convex complementary cross sectional surface, a final pair of rolls having concaved surfaces arranged to press the tube parts and headed edges together, and intermediate pairs of rolls having center portions that are convex on one roll and complementarily concave on the other roll with grooves at either side arranged to gradually turn in the head.

7. In a machine for bending and forming metal tubing, the combination of aplurality of pairs of shaping rolls having surfaces arranged to take a fiat piece of ribbon and gradually curve the cross section of the same and turn in the edges and press the whole together to form a substantially closed tube having turned-in or beaded meeting edges,

the initial pair of rolls comprising a convex sively turn the edges in to form the bead.

8. In a machine for forming and bending metal tubing or moulding, comprising a plurality of pairs of rolls all arranged with the lower rolls in alignment and shaped to pro gressively shape the cross section of the tubing or moulding, and means located in proximity with the rolls for causing the tubing or moulding when leaving the shaping rolls to bend into a coil, said parts being arranged so that the work is fed continuously through all the sets of rolls in the form of coils from roll to roll.

9. A machine for forming and bending metal tubing or moulding, having in combination, a plurality of sets of shaping rolls having the lower rolls in alignment, and guiding members in proximity'with the rolls and arranged in conjunction with the rolls to coincidently cause the tube leaving the rolls to bend in coils of progressively less diameter, said work being fed through the shaping rolls and the guides continuously in the form of coils from one set of rolls to the next.

10. .A machine for forming and bending metal tubing or moulding, having in combination, a plurality of sets of shaping rolls arranged with the lower rolls in alignment, and guiding members located in proximity with each set of rolls and angularly removedfrom the perpendicular to the line normal to the axes of the rolls, the degree of angular offset increasing from the first set of rolls to the last set of rolls whereby the WOI'k can be fed through the rolls continuously in the form of coils of decreasing diameter.

11. The method of shaping and bending metal tubing or moulding, which com rises the moving of a strip of metal longitudinally and coincidently subjecting the same to stresses calculated to fashion its cross sec tion and stresses calculated to fashion its longitudinal run into a coil of progressively reduced diameter as the strip meets successive stresses.

12. The method of forming and bending metal tubing or moulding, which comprises the moving of a metal strip longitudinally and while so moving subjecting the same to the restraint of successive sets of obstacles calculated each set to progressively shape the cross section of the metal and coincidently cause the tubing or moulding to coil lengthwise in a progressively reduced diameter after going through eachset.

13. The method of forming and bending the'said strip being ed throng metal tubing or moulding, which comprises causing a metal strip to travel longitudinally and subjecting the same successively to independent sets of stresses, each set calculated to coincidently both progressively shape its cross section and bend it longitudinally on a progressively Smaller radius, the successive sets calculated to bring the shapes gradually nearer the final shape.

14. In a machine for forming and shaping metal tubing and molding, the combination of a plurality of sets of rolls, and means operating in conjunction with each set'of rolls for bending the said Strip longitudinally into coils of progressively smaller diameter after each pass.

15. In a machine for forming and shap ing metal tubing or molding, the combination of a plurality of sets of rolls. and separate guide means located in proximity with each set of rolls and acting coinci dentally with said rolls for bending the said tubing or molding longitudinally into coils of progressively smaller diameter after each pass.

16. In a machine for forming or shaping metal tubing or molding, the combination of a plurality of sets of rolls, and separate guiding means operating in connection with each set of rolls and coincidentally therewith for bending said tubing or molding longitudinally, each succeeding guiding means having a larger angle to the per-- pendicular to the center line of the roll set for progressively reducing the diameter of the coil after each pass.

17. In a machine for forming and shaping metal tubin or molding, the combination of a plurality of sets of shaping rolls, the said roll sets being arranged in end to end relation, and means for guiding and coiling a strip of metal to feed the same continuously through said end to end arranged rolls in the form of a plurality of coils.

18. In a machine for forming and shaping metal tubing or molding, the combination of a plurality of sets of section shaping rolls arranged in end to end relation and guiding means operating in conjunction with the plurality of said sets of rolls'for feeding a metal strip continuously through said end to end arran ed shapinf rolls and the rolls in the form of a plurality of coils of gradually reducing diameter.

n testimony whereof I affix my signature.

FRANK KRITZ.

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