US2734472A

US2734472A - Bornand

Info

Publication number: US2734472A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

Feb. 14, 1956 R. 50mm 2,134,412

APPARATUS FOR PRODUCING FLEXIBLE TUBING Filed July 25. 1951 FIG/I Wane 7.9017; and

INVEN T OR APPARATUS FOR PRODUCING FLEXIBLE TUBING Ren Bornand, Zurich, Switzerland 7 Application July 25, 1951, Serial No. 238,540

Claims priority, application Switzerland July 27, 1950 1 Claim. (Cl. 11335) My present invention relates to an improved apparatus for producing flexible tubing from band-material wound in form of narrow disclike rolls on reels or mounts.

Methods and apparatus are known in which the bands or tapes are wound on a winding bush or mandrel in overlapping coils to form a tube which by means of folding tools is continuously corrugated and subsequently provided with helical grooves. The rate of production of such known apparatus, however, is limited by the tools. In practice, the finished tubing delivered from the apparatus is subjected to a more or less constant rotation or twist about its axis. Such twist excessively hinders the operation of continuously winding the finished tubing on the reel, and the stresses arising therefrom may lead to ruptures.

It has been proposed to avoid such twist by restraining the finished grooved tubing from twisting upon being issued from the apparatus. This has been done, for example, with the aid of a non-rotatable brake sleeve which tightly embraces the tubing. Such brake sleeve is provided with longitudinal grooves and is adjustably resilient, the raised portions of the said grooves digging themselves continuously into the tube surface by accordingly setting a regulating means. Since such straight-jacketing of the tube gives rise to an increasingly stiffened guiding thereof, the force for pushing the tube through the said brake sleeve has to be continuously increased. Such thrust, however, is produced by the feed which is derived from the pitch or lead of the folding tools. The same thrust causes, in known manner, the close-up or approach of the helical corrugations of the band-material tubing, which corrugations have been preformed by the folding tools. The frictional resistance in the folding tools known so far, which tools in principle are based on sliding friction, thus is additionally increased. In order, however, to establish the balance requisite for the positive functioning of the tubing machine, the various bands have to be tightly stretched. Apart of the structural means required for such band-braking, the latter requires a very careful and time-consuming attendance. This again gives origin to an accumulation of band failures and the like which lead to breakdowns. It also may happen that the heat produced by friction in the tool, becomes excessive so that the banded tube will pit the hardened tools, even though the latter be fluid-cooled.

In contrast to such known methods, the bands according to my present invention are wound up on a freely rotatable winding mandrel or bush, whereupon the formed banded tube is continuously deformed in corrugations through at least one set of profiled rotating inside and outside deforming rollers, and subsequently provided with helical grooves with the aid of upsetting means.

n winding the bands on to a sleeve mandrel which is loosely mounted on a driven shaft, the mandrel and the banded tube therefore will execute a constant slight rotary movement depending on the tool and on the size of tube. Such rearward transmission of the relative movement behind its point of origin is substantially fanited States PatentO 2,734,472 Patented Feb. 14, 1956 cilitated by the roller tools which are built on the principle of rolling friction. Further, the bands drawn ofl the supply rolls have to be stretched only to such an extent yet as to ensure a positive run-off and a uniform winding operation. The banded sleeve wound upon the winding mandrel then may be easily stripped off with the aid of the deforming tools. To further facilitate such stripping, the winding mandrel may be slightly tapered in a direction towards the deforming tools.

Since roller tools on one hand develop a relatively low heat of friction and, on the other hand, make it possible to execute the deforming operation either steplessly or by steps, depending on the number and profile of the pairs of rollers employed, the rate of production may be substantially increased in comparison with the known processes and machines.

One form of my present invention is shown, by way of example, in the accompanying drawing which only illustrates that portion of the machine which is essential for a clear understanding. With the aid of the drawing, the method disclosed in my present invention also will be more fully explained by way of example. In the draw- 111g,

Fig. 1 shows the deforming and upsetting means of the apparatus in axial section,

Fig. 2 depicts, to a larger scale, an upsetting roller in elevation,

Figure 3 shows, also in a larger scale, in elevation a deforming roller having a plurality of axially spaced ribs,

Fig. 4 illustrates, also to a larger scale, a deforming worm in elevation.

The apparatus shown in Fig. 1 comprises a substantially cylindrical casing A which through the prop B is secured to the frame (not shown). A driven shaft 47 which is rotatably mounted in the machine axis, in turn serves as a support for a mandrel 35 which is freely rotatable in the ball bearing 34. The forward end of mandrel 35 projects into the casing A.

By winding the bands 17-which are drawn off supply rolls (not shown) via deflecting means in helically overlapping relation-on the mandrel 35, a banded sleeve 42 is produced. The sleeve 42 is deformed to a corrugated tube 45 through the synchronous rotation of exterior deforming rollers 43 and interior deforming rollers 44. The latter are secured on the shaft 47 which is driven, by suitable means, not shown. The shaft 47 is mounted in the apparatus, in a manner not shown, by means of a bearing which accommodates the axial thrust produced by the deformation. The helical corrugations 49 in the tube are produced by horizontally inclining or disposing at an angle the

axles

50 and 51 of the deforming rollers relative to the axis 31 of the casing A as viewed in Fig. 1. The exterior deforming rollers 43 are mounted by axles 51 in a tool holder 52 which is driven through a chain and is guided in a bearing 53. A tool holder 55 carries axles 56 provided with upsetting rollers 54 which serve for upsetting the corrugated tube 45, the axle pin 56 of the upsetting rollers being inclined in the same manner as

axles

50 and 51. The bearings 57 serve for guiding and accommodating the working pressure of the holder 55. A spring 58 serves for balancing any transient pressure differences. The entire tool holder 55 may be axially moved through screws 59 and is driven through a V-belt 60.

The upsetting roller shown in Fig. 2 has a rib 97 which stands at right angles to the axle 96 and is adapted to the permanent grooves of the finished tubing. The deforming roller 98 shown in Fig. 3 has a circular profile which stands at right angles to its axle 99 and has a plurality of

ribs

101, 102 and 103 of successively increasing size for the purpose of effecting a stepwise increasing deformation of the banded tube.

The deforming roller 104 shown in Fig. 4 is of worm shape. Consequently, its axle 99 can be parallel to machine axis 31 to still produce helical grooves. The outside diameter alone, as well as the entire cross-section 105 may be of gradually increasing dimensions from one end of the deforming roller 104 to its other end so as to afford a gradual increase in deformation.

The exterior and interior deforming rollers are so arranged that, as shown in Figure 1, the opposing surfaces thereof provide axially spaced, radially projecting, circumferentially extending, interdigitated ribs for forming the corrugations in the tubing with relatively small rolling friction.

As will be readily appreciated, the use of interior and exterior deforming rollers offers particular advantages, especially in the production of tubing of relatively large diameters, since the relatively small rolling friction of the deforming rollers permits a higher rate of production than known apparatus in which these rollers rotate with sliding friction.

What I claim as new and desire to secure by Letters Patent, is:

In an apparatus for producing endless, flexible corrugated tubing from helically wound, overlapping bands of material, means for reducing twisting stresses on the finished tubing caused by the tendency of the tubing to rotate due to the action of the corrugating means, said means comprising a driven shaft, a sleeve mandrel freely rotatably journaled on said shaft and on which the tube forming bands are helically wound into tube shape, co-

operating interior and exterior freely rotatable deforming rollers for continuously corrugating the tubing through rolling engagement therewith as the tubing is stripped from said mandrel, said interior rollers being carried by said shaft beyond the end of said mandrel for circumferential movement about the shaft axis in response to rotation of said shaft, said exterior rollers being mounted for concentric movement about said shaft axis, means for rotating said exterior rollers about said shaft axis in synchronization with said interior rollers, said exterior and interior deforming rollers having radially projecting axially spaced, circumferentially extending, interdigitated ribs on the opposing surfaces thereof for corrugating the tubing as it is stripped from the mandrel, and means for crowding the corrugations comprising outer, freely rotatable, upsetting rollers spaced axially from said deforming rollers and seating in the corrugation grooves of the tubing, means driving said upsetting rollers to cause said crowding of the corrugations, all of said rollers having their axes disposed radially outwardly from said shaft axis.

References Cited in the file of this patent UNITED STATES PATENTS 947,229 Fulton Jan. 25, 1910 1,417,324 Holmes May 23, 1922 1,583,212 Williams May 4, 1926 1,793,280 Williams Feb. 17, 1931 2,002,896 Kopetz May 28, 1935 2,162,355 Parrish et al. June 13, 1939 2,350,070 Shellmer et al May 30, 1944 FOREIGN PATENTS 375,676 Great Britain June 30, 1932 597,116 Great Britain Jan. 19, 1948