US3899143A

US3899143A - Tension control device

Info

Publication number: US3899143A
Application number: US432133A
Authority: US
Inventors: Raymond J Slezak
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-01-10
Filing date: 1974-01-10
Publication date: 1975-08-12
Anticipated expiration: 1992-08-12

Abstract

Disclosed is a tension control device for spooled filamentary material which includes a support structure, a spool support for the filamentary material rotatably carried by the support structure, and a rotatable pivot shaft. A first lever fixed on the shaft carries a guide means for tensioning the filamentary material withdrawn from the device and a brake which engages the spool support. A second lever is fixed on the pivot shaft and carries an adjustable loading device which applies a predetermined load to the first lever to maintain a constant tension in the filamentary material.

Description

[4 1 Aug. 12, 1975 Primary Examiner-Robert J. Spar Assistant ExaminerKenneth Noland Attorney, Agent, or FirmHami1ton, Renner & Kenner [57] ABSTRACT Disclosed is a tension control device for spooled filamentary material which includes a support structure, a spool support for the filamentary material rotatably carried by the support structure, and a rotatable pivot shaft. A first lever fixed on the shaft carries a guide means for tensioning the filamentary material withdrawn from the device and a brake which engages the spool support. A second lever is fixed on the pivot 558 Princeton St., Barberton, Ohio 44203 Jan. 10

Appl. No.: 432,133

TENSION CONTROL DEVICE Inventor: Raymond J. Slezak,

US. Cl. 242/1562; 242/7543; 254/173 Int. Field of Search 254/149 References Cited UNITED STATES PATENTS United States Patent Slezak [22] Filed:

shaft and carries an adjustable loading device which applies a predetermined load to the first lever to maintain a constant tension in the filamentary material.

6 Claims, 2 Drawing Figures 10/1956 1/1959 .lurs et a1. 3/1959 Nelson............................. 2,983,468 5/1961 Perre1la............................ 3,076,618 2/1963 Hook 3,081,957 3/1963 Van De Bi1t.. 3,355,122 11/1967 Thatcher........................t.

2322223 646646 5555555 WWWWUZZ 4444444 2222222 PATENTED AUG I 2 I975 SHEET IIIIIIIMMI 2 V II PATENTED AUG 1 2 3975 SHEET FIG. '2

TENSION CONTROL DEVICE BACKGROUND OF THE INVENTION This invention relates to an automatic tension control device for regulating the amount of tension under which a filamentary material is withdrawn from a spool. The device is capable of maintaining a substantially uniform and preselected tension in a filamentary material, although more readily adjustable, structurally less complex, more responsive under certain circumstances, and otherwise advantageous in comparison with known prior art devices designed to so function.

Filamentary materials include single and multiple strand fibers produced in long lengths and conveniently wound on spools. The various filaments may be either natural or synthetic fibers, glass or metal. Such materials are commonly utilized as reinforcements for plastic or elastomeric compounds or they themselves may be fabricated into integral items as in the textile industry. Regardless of the application it is customary to withdraw the filamentary material from the spool at or near the location it is being used. To facilitate such removal, the spool is customarily mounted on a spindle or creel assembly which permits the spool to rotate as the filament is withdrawn.

Because payout of the filament from the spool may be at a high linear velocity thereby imparting substantial momentum to the spool and related spindle mounting components, it is necessary to dissipate force rapidly in the event the filament breaks or the takeup sud- .denly decreases. In either situation, filament will be payed out more rapidly than it is needed until rotation of the spool can compensate. Obviously, the problem is greatly multiplied when a creel assembly carrying up to several hundred spools is being used.

Numerous braking devices have been developed for use with creels. Many of these provide for the filament to be payed out under tension greater than what is required for payout from the spool. As the tension decreases, with slack in the filament, a braking force is SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a tension control device which provides for payout of filamentary material at a uniform tension selected from a substantial range irrespective of the rate at which the filament is taken up.

It is another object of the present invention to provide a tension control device which maintains substantially uniform tension on a spool of filamentary material from full to empty spool condition.

It is a further object of the present invention to provide a tension control device which is relatively com pact and readily adjusted so as to accommodate various filamentary materials.

It is yet another object of the present invention to provide a tension control device which may be loaded by air pressure regulation to provide a plurality of predetermined tension settings and, other than during the changing of settings, does not require an air flow as no air is consumed.

It is still another object of the present invention to provide a tension control device or plurality thereof the selected tension of which may be readily varied remotely by a single adjustment.

It is a further object of the present invention to provide a tension control device which exhibits a minimum of hunting or loping in the form of periodic variations about a selected tension setting substantially irrespective of how high the tension setting, eccentricities in the spools, and related factors.

It is a still further object of the present invention to provide a tension control device the operation of which is within normal operating limits substantially independent of the coefficient of friction between braking components.

These and other objects of the present invention, together with the advantages thereof over existing and prior art forms which will become apparent from the following description, are accomplished by the means hereinafter described and claimed.

In general, a tension control device for spooled filamentary material includes a support structure, a spool support for the filamentary material rotatably carried by the support structure, and a rotatable shaft. A first lever is fixed on the shaft. A filament guide carried by the first lever is bodily movable therewith as the filamentary material passes from the device, and a brake carried by the first lever selectively frictionally engages the spool support in response to changes in tension of the filamentary material as it passes over the guide. A second lever is also fixed on the shaft, and carries an adjustable loading device which applies a predetermined load to the first lever to maintain constant tension on the filamentary material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation of the tension control device depicting movement of the first and second levers in phantom and a spool of filamentary material, also in phantom; and,

FIG. 2 is a side elevation depicting the guide means and the means for controlling the amount of tension necessary for braking of the spool supporting means.

DESCRIPTION OF THE PREFERRED EMBODIMENT The tension control device, indicated generally by the numeral 10, includes a support structure, generally indicated by the numeral 11, upon which is mounted a spool support, generally indicated by the numeral 12. First and second levers, 13 and 14 respectively, are fixed on a pivot shaft 15 rotatably carried by the support structure 11. The first lever 13 carries a guide roller l6 and a brake shoe l8, and an air cylinder 19, is connected to the second lever.

The support structure 11 includes a rectangularly shaped plate 20 which may be bolted to a suitable frame assembly (not shown) upon which a plurality of devices 10 may be arranged. Axially extending from the plate 20 is a cylindrical hub 21 which in turn supports two radially extending arms, as shown laterally extending arm 22, and downwardly extending arm 23. As depicted in FIG. 2, the hub 21 and plate 20 need not be perpendicularly related one to the other, thereby allowing a spool of filamentary material 24, depicted in phantom, to be upwardly inclined from the device as the filament is withdrawn so that it remains seated against the spool support described hereinafter. Of course, this angular relationship between the plate and hub 21 may be varied during assembly pursuant to the specific requirements of a given application.

The spool support 12 includes a spindle 25 which extends into the hub 21 being rotatably mounted therein with anti-friction bearings. The spindle 25 is of a suitable length and diameter so as to pass through the center of spool 24, and if desired, it may itself receive a larger spindle to properly fit varying spool dimensions. Mounted on the spindle 25 and rotatable therewith is a circular backing plate 26 which may be provided with a spacer 28 to maintain the spool 24 away from the plate 26. At least one guide pin 29 is threadably mounted in said backing plate 26 and is engageable with a bore in the spool 24 whereby the backing plate 26, spindle 25 and spool 24 will rotate as one when the filament is withdrawn. If desired, a second pin may be substituted for the bolt 30 which passes through spacer 28. A bearing 31 maintains the backing plate 26 a fixed distance from the hub 21. The circular backing plate 26 functions as a brake drum, as will be described hereinbelow, and has a smooth circumferential braking surface 32, facilitating the desired braking in response to changes in tension occurring with variances in the rate of filament takeup.

Attached to the end portion of the arm 23, extending from the hub 21, is a cylindrical housing 33 which receives the shaft 15, freely rotatable therein. On the outboard end of the shaft 15, i.e., away from the plate 20, the elongated, curved control lever 13 is secured, the lever 13 having a bore 34 for receipt of the shaft 15.

As depicted in FIG. 1, thecontrol lever 13 is pivotable toward and away from the spindle 25. The control lever 13 terminates a short distance beyond its connection with the shaft 15 in a clevis 35. The brake shoe 18 is supported by a cylindrical stem 36 having a block 38 therein which is received by the clevis 35. The stem 36 passes freely through the block 38 and terminates in a head 39, engageable with a wrench for removal of the brake shoe 18. A pin 40 passes through a bore 41 in the clevis and through the block 38 permitting a limited amount of pivotal movement therebetween as the control lever 13 pivots about the shaft 15. A compression spring 42 encircles the stem 36 and is interposed between the block 38 and brake shoe 18 to resiliently bias the brake shoe 18 toward the braking surface 32 to provide a somewhat gradual or cushioned application and release of the braking force, thereby reducing response sensitivity to pivotal movement of lever 13. A sleeve 37 interposed between stem 36 and spring 42 precludes the possibility of excessive compression of spring 42 which could eventually result in a fatigue failure.

The brake shoe 18 is provided with a suitable lining 43 which engages the braking surface 32 on the'back ing plate 26.

Guide tabs

44 and 45 are fastened to the rear of the shoe 18 with

screws

46 and 48 respectively. The

tabs

44 and 45 function to maintain positive alignment between the plate 26 and the brake lining 43, ar-

resting any tendency for the brake shoe 18 to rotate about the stem 36.

The opposite end 50 of the control lever 13 carries the guide roller 16 rotatably mounted on a shaft 51 extending perpendicularly from the lever 13 and generally parallel with the spindle 25 and spool 24. A removable collar 52 maintains the roller 16 on the shaft 51. The roller 16 preferably includes a smooth cylindrical metal drum 53 over which the filament F passes. As the filament F is payed out from the spool and passes over the drum 53 it is maintained thereon by

lateral flanges

54 and 55. The roller 16 is preferably dimensioned to be as long as the height of a spool 24 to insure the smooth and uniform withdrawal of the filament F from the spool 24 without fouling.

A second, lever 14 is secured at one end on the inboard end of the shaft 15, the

levers

13 and 14 and the shaft 15 being pivotable with respect to the cylindrical housing 33 through which the shaft 15 passes. At the opposite end of the second lever 14, a yoke 56 is affixed as by a nut 58 and bolt 59. The upper end of yoke 56 is connected to a piston rod 60 as by a pin 61. The piston rod portion 60 extends from an air cylinder 19 which is preferably a low friction, rolling-diaphragm type of cylinder. The upper end portion 62 of the cylinder 19 is preferably pivotally fixed as by an angled support brace 63 which may be fastened to the arm 22, laterally extending from the hub 21, as by a nut 64 and screw 69. The cylinder 19 is supplied air at its upper end by an air hose 66 connected to a suitable source of air (not shown). The arm 22 may also carry a stop for the control lever 13 which consists of a rubber bushing 68 mounted on the arm 22 by the screw 69 passing through the bushing 68 and secured by nut 64 and half nut 65.

The control lever 13, the lever 14, and the abovedescribed components connected thereto are advantageously constructed of lightweight material in order to reduce momentum in the system and thus further minimize hunting or oscillation tendencies of the control lever 13 which might otherwise exist. For example, constructing the

lever

13, 14 of heat treated aluminum has been found to satisfy the weight and strength requirements.

Having described the component parts of the device 10, the preferred operation thereof is as follows. A spool 24 of filamentary material is mounted on the spindle 25 and the filament F is led counterclockwise, as depicted in FIG. 1, from the top of the spool 24, under and around the guide roller 16 in a clockwise direction and to the take-up source (not shown). Prior to actuating the take-up, the control lever 13 and guide roller 16 will repose away from the spool 24, as depicted in phantom in FIG. 1. At this time, the brake shoe l8 urged by lining 43 will be firmly engaging the braking surface 32 thereby arresting rotation of the circular backing plate 26 and spool 24 so that the filament F cannot be payed out.

As the filament F is taken up, it will draw the guide roller 16 and control lever 13 toward the spool 24 and in so doing, will reduce the friction force between the brake lining 43 and the braking surface 32 permitting the spool 24 and backing plate 26 torotate. Travel of the control arm toward the spool 24, and concurrent reduction of the braking force is limited by the rubber bushing stop 68 in the event of an extreme variation in the take-up velocity.

The force exerted on control lever 13 by the filamentary material in engaging guide roller 16 is balanced against the friction between the lining 43 and braking surface 32 to maintain a constant tension in the filament F. The tension from this force-balance system is, within normal operating limits, independent of the coefficient of friction between the braking surfaces. In the event the take up decreases in rate or ceases, the requisite amount of braking is immediately applied so there is never any undesirable slack created in the filament F. Likewise, upon an increase in the rate of takeup, the balance between the. braking force and the force applied by the cylinder 19, permits a smooth and uniform rate of payout without stretching or jerking of the filament F.

By applying a relatively low amount of air pressure, e.g., approximately p.s.i., to the air cylinder 19, the piston rod 60, through the yoke 56, tends to urge the second lever 14 to rotate in a counterclockwise direction, thereby applying a torsional force about the shaft 15, as depicted in FIG. 1. Since this torsional force must be overcome by the force exerted on lever arm 13 by guide roller 16 as produced by the filament tension before the arm 13 rotates in a clockwise direction as seen in FIG. 1, it constitutes a biasing force substantially proportional to the tension in the filament. Thus, the filament tension may be selectively varied by controlling the air pressure in air cylinder 19.

Because the cylinder 19 normally does no work, a continuous flow of air thereto is not required. It need only be supplied at the necessary pressure quantity to achieve the desired tension in the filament which it will retain and utilize until deliberately changed as for a different tension more conducive to another filament or a change in operating conditions. A plurality of the devices 10 could all be supplied from the same regulated source concurrently to provide equivalent tension in a plurality of filaments. Such a source may be at least in part remotely located for convenient tension adjustment when required. Also, on account of the balance system tension in the filament F will remain substantially uniform from a full spool to empty, despite the fact that the spool rotates more rapidly as it is emptied, the common eccentricities in spools, and other irregularities.

Thus, it should be evident that the disclosed device carries out the objects of the invention set forth above. As apparent to those skilled in the art, modifications can be made without departing from the spirit of the invention herein disclosed and described, the scope of the invention being limited solely by the scope of the attached claims.

What is claimed is:

l. A tension control device for spooled filamentary material comprising: a support structure, means rotatably supporting a spool in said support structure, means having a friction brake surface associated with said means rotatably supporting a spool, a shaft journaled in said support structure, a first lever fixed on said shaft, filament guide means mounted on one end of said first lever for engaging the filamentary material payed out from said spool, brake means mounted on the other end of said first lever for engagement with said brake surface, means for resiliently biasing said brake means against said brake surface interposed between said brake means and said first lever, a second lever fixed on said shaft, and an air cylinder having a fixedly mounted portion and a portion connected to said second lever for loading of said first lever in order to balance the force acting on said first lever, exerted by the filamentary material against the filament guide means, and the friction between the brake means and brake surface and to maintain a selected tension in said filament.

2. A tension control device, as in claim 1, wherein said first and second levers and means mounted thereon and connected thereto are of relatively light weight material.

3. A tension control device, as in claim 1, wherein said adjustable means has the fixedly mounted portion attached to said support structure.

4. A tension control device, as in claim 1, wherein said shaft is radially offset from said supporting means.

5. A tension control device, as in claim 4, wherein said support structure comprises a base plate and a hub mounting said spool supporting means having a radially extending arm mounting said shaft.

6. A tension control device, as in claim 3, wherein said support structure has a second radially extending arm on which said means for loading said first lever is mounted.

Claims

1. A tension control device for spooled filamentary material comprising: a support structure, means rotatably supporting a spool in said support structure, means having a friction brake surface associated with said means rotatably supporting a spool, a shaft journaled in said support structure, a first lever fixed on said shaft, filament guide means mounted on one end of said first lever for engaging the filamentary material payed out from said spool, brake means mounted on the other end of said first lever for engagement with said brake surface, means for resiliently biasing said brake means against said brake surface interposed between said brake means and said first lever, a second lever fixed on said shaft, and an air cylinder having a fixedly mounted portion and a portion connected to said second lever for loading of said first lever in order to balance the force acting on said first lever, exerted by the filamentary material against the filament guide means, and the friction between the brake means and brake surface and to maintain a selected tension in said filament.