US2929573A - Compensating mechanism for taping machines and the like - Google Patents

Description

O. HAUGWITZ COMPENSATING MECHANISM FOR TAPING MACHINES AND THE LIKE March 22, 1960 2 Sheets-Sheet 1 Filed Jan. 28, 1957 March 22, 1960 Filed Jan. 28, 1957 0. HAUGWITZ COMPENSATING MECHANISM FOR TAPING MACHINES AND THE LIKE 2 Sheets-Sheet 2 COP/ftPENSATlNG MECHANISM FOR TAPING MACHINES AND THE LIKE Otto Haugwitz, La Celle Saint Cloud, France, assignor to Societe Anonyrne Geofiroy-Delore, Paris, France, a French company Application January 28, 1957, Serial No. 636,663

Claims priority, application France April 5, 1956 1 Claim. (Cl. 24275.45)

This invention relates particularly though not exclusively to taping machines of the kind used in providing wound tapes of insulation around electric cables, and for analogous purposes.

Such machines comprise one or more heads each supplied with tape from one or more reels. The tape may be paper, fabric or other sheet material. The reels of tape are mounted on rotatable shafts'which are driven in rotation as the paper tape is reeled c-fi. Since the tape must be wound about the cable under a constant predetermined tension, means are provided, such as brake shoes engaging brake drums secured to the shafts rotatable with the reels of tape, for determining the winding tension. However, as the tape is reeled off, the diameter of the reel of tape is gradually reduced whereas the brake drum diameter remains unchanged so that the winding tension tends to drop off as the winding operation proceeds. Compensating means have to be provided for keeping the braking force at all times proportional to the varying radius of the reel of tape throughout the operation. It has been found that the compensating means heretofore proposed for this purpose are unable to ensure a strict uniformity in the winding tension from start to finish of the winding process.

The present invention is broadly concerned with the provision of compensating devices of a similar character applicable to any type of system for winding tape, strips, wires, or the like on or from a reel wherein the diameter of the reel diminishes during the winding operation, and wherein the winding tension is nevertheless required to retain a high degree of constancy. The object of the invention is to provide a compensating mechanism for such purpose, whereby the braking force will remain at all times proportional to the instantaneous radius of the reel.

in accordance with the invention, there is provided a mechanism including a movable member, e.g. a roller, engaged by the tape (or other similar element) as the latter is fed from or to the reel so as to be displaced gradually as the radius of the reel of tape is changed, and means connecting the movable member to a brake member such as a brake shoe engaging a braking surface rotatable with said reel so as to apply a braking force dependent on the position of said movable member and hence on the instantaneous radius of the reel of tape, in such a way that the resulting pressure exerted by the braking member will at all times remain substantially proportional to said radius.

A clearer understanding of the invention will be had from the ensuing exemplary description made with reference to the accompanying schematic drawings, wherein:

Fig. 1 is a front view of a first embodiment of the invention;

Fig. 2 is a side view corresponding to Fig. 1;

Fig. 3 is an explan tory diagram illustrating the operation of the device of Figs. 1 and 2 for various values of the reel radius; and

ited States Patent v ice Fig. 4 is a similar diagram relating to a modified form of the embodiment shown in Figs. 1 to 3.

Referring to Figs. 1 and 2, 1 designates a stationary shaft secured in a machine frame, not shown. A cylindrical hub 2 is rotatable on the shaft 1 and has a disc 3 secured to it. A reel 3a of paper tape 4 is fitted around the hub 2 and is blocked against the face of disc 3 by means of a screw ring 5 or the like to prevent relative slippage between the reel of tape 4 and the hub and disc assembly. A brake shoe 6 is shown as engaging the periphery of the disc 3, though said brake shoe may obviously be arranged to engage the periphery of a brake drum integral with the disc. The brakeshoe 6 is mounted on one end 7 of a two-armed lever 8 pivoted on a pin 9 secured to the frame. A spring 11, the bias tension of which is adjustable by means of a screw 12, is threaded into an aperture formed in a part of the frame 13 and acts through a pull rod 14 on one end 10 of the lever 8 thereby tending to apply the brake shoe 6 on disc 3 under predetermined pressure. The

end 10 of lever 8 is connected by a link 15, which may extend at any appropriate angle to rod 14, with a roller 16 freely journalled on a pin 17. The pin 17 is connected by way of a lever 18 of any suitable length with a pivot 19 secured to the frame; alternatively the pin 17 may be mounted freely between a pair of slideways disposed at right angles to a lever similar to the lever 18 shown. A tension roller 20 is mounted on a pin 21 secured to the frame. Preferably the pins 17 and 21 are so arranged that when the reel is in its initial full condition the length of the tape 4 extending therefrom is undefiected by the roller 16, being tangent thereto, then passes around the roller 20, and then toward any suitable drive means such as a drive pulley which will impart to it the requisite feed tension.

When the tape is reeled off and as the radius R of the reel diminishes, the tape 4, subjected to the feed tension which is to be held constant, defines at the roller 16 an angle which initially is in the full condition of the reel, and then diminishes along with the radius, as indicated by the values R R R and R thereby creating a force Q applied to the pivot axis of the roller 16. As may readily be seen both from calculation and from the geometrical diagram shown in Fig. 3, the variation in magnitude of the force Q, is not proportional to the variation in the radius R Instead, the force Q increases relatively to the radius at too fast a rate in the initial stage of the reeling process and too slowly towards the end of the process. However, since the angle between the direction of application of the force Q and the direction of link 15 itself decreases, and owing to the mechanical constraint applied to the pivot 17 as described, i.e. by the slideways parallel to the link 15 or the lever 18 illustrated as being normal to said link. only that component of force Q extending in the direction of the link 15 is operative, viz the components Q Q Q Q and Q In other words, the roller is supported for limited movement in a direction substantially longitudinally aligned with link 15, e.g. by the lever 18 or by the slideways mentioned above, as will be seen from Fig. l which illustrates a mounting employing the lever 12%. Therefore, components corresponding, respectively, to components such as Q Q Q and Q, are obtained which, to a sufiiciently high degree of approximation, are proportional to the quantities (R -R (R R (R R These components exert upon the two-armed lever 8 at the point 9, couples that are proportional in magnitude to the variations in radius of the reel of tape, and directed so as to oppose the couple exerted by spring 11. Thus the variation in braking pressure of brake shoe 6 on brake disc 3 will be proportional to the variation in radius of the reel of tape,

Patented Mar. 22, 1960 t and the tension of the tape 4 remains constant While the speed of rotation of the reel increases. By suitably selecting the spacing between pivot 9 and link 15 and ample the respective components Q Q Q Q Q act in a common direction on the spring 11 so that the spring tension is obviously reduced with respect to that obtained in' the first embodiment. In'the instant embodiment the Q component is a maximum as the reel of tape is full and becomes zero when the reel is empty.

The-basic operating principle is-the same, and the desired result of'maintaining a constant tension is again accomplished. a

It willbenoted inboth preceding embodiments that since the brake shoe 6 remains applied on disc 3, themtire mechanism controlling the variation in braking force is:stationary with respect to the reel of tape. Such -arrangement is advantageous in that the component parts are'simpler, both in construction and in their relationship and assembly, than is the case with conventional tension regulatingsystems involving movable components. Another favorable consequence of this relatively stationary condition is the elimination of inertia forces.

Although only a few exemplary embodiments have been illustrated a large number of modifications may be conceived without exceeding the scope of the invention.-

WhatVI claim is:

An automatic braking system for a feeding device adapted to feed at constant speed and tension a continuous strand wound in a reel upon a rotatable support having a braking surface, the radius of said reel decreasing as the strand is payed out, comprising, in combination, a lever pivoted about 'a fulcrum and having a first arm and a second arm, a-brake'shoe carried by said first arm of said lever and positioned to engage said braking surface, resilient means biasing said brake shoe toward said braking surface to apply said brake shoc thereto, a first discharge roller and a second discharge roller each engaged by the strand as it is payed out, said second roller being mounted upon a fixed axis and said first roller being disposed between said reel and said second roller, a link connected to said second arm of said lever, said first roller being mounted for rotation on said link, whereby force acting on said first roller is transmitted through said" link-and said-lever to said brake shoe, and means supporting said first roller for limited movement in a direction substantially longitudinally aligned with 7 said link, 7

References Cited in the file of this patent UNITED" STATES PATENTS Reardon May 25, 1943 use

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