US2507297A

US2507297A - Tension equalizing apparatus

Info

Publication number: US2507297A
Application number: US62153A
Authority: US
Inventors: Yves A Bouget
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1948-11-26
Filing date: 1948-11-26
Publication date: 1950-05-09
Anticipated expiration: 1967-05-09

Description

y 9 1950 Y. A. BOUGET 2,507,297

TENSION EQUALIZING APPARATUS Filed Nov. 26, 1948 2 Sheets-Sheet 1 INVENTOR m. BOUGEZ" BY A T TOPNEV May 9, 1950 Y. A. BOUGET TENSION EQUALIZING APPARATUS [[HIH IIv Filed Nov. 26, 1948 INVENTOR KABOUGET A from/5v I Patented May 9, 1950 TENSION EQUALIZING APPARATUS Yves A. Bouget, West Orange, N. J., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application November 26, 1948, Serial No. 62,153

This invention relates to apparatus for equalizing tension in material pulled from a rotatable supply of the material and has for its object a sensitive mechanism affected by variations in the pull on the material at the supply to create.

constant tension in the material.

The speeds at which material handling machines may operate depend largely upon the eiliciency of the mechanisms associated therewith in controlling the tensions in the materials. During unwinding of sheet material from a supply roll, by pulling the material from the supply, there will exist the problem of the gradually diminishing diameter of the supply roll effectin a gradual increase in tension. During unwinding of strand materials from reels the effective variations in the supplies on the reels occur only at the end of one layer of convolutions and the beginning of another layer. This factor is more disturbing than the gradual increasing of tension in the sheet material in that there is a tendency for the strand material to be shocked by these sudden changes resulting in possible damage to the strand material if a highly sensitive mechanism is not provided to allow for these abrupt attempts to vary the tension in the material.

With the aforementioned object in view, the invention comprises an apparatus for equalizing the tension in material pulled from a rotatable supply of the material, the rotation of the supply resulting from the pull on the material being removed from the supply. The apparatus is employed in combination with a variable displacement fluid piston motor-pump having a shaft rotatable about a fixed position axis and.

a compensator variable with variations of tensions in the material to act as a controlling factor. The tension equalizing apparatus includes a cradle supported for rocking movement about the axis of the shaft and is formed to receive a spindle for removably supporting the supply of material. The material supply is caused to rotate with the spindle and a unit is variable, depending on the tension to be created in the material pulled oif the supply, to normally urge the cradle in a direction opposite the direction of pull of the material on the supply. A mechanism operatively connecting the spindle and the shaft causes variation of the pressure of. the

fluid in the control motor-pump unit with variations of the tension in the material, and as a result of the motor-pump unit will act as either a. motor or a pump to correct such irregularities in tension.

6 Claims. (cl. 242-45) More specifically, the cradle is substantially U-shaped in general contour, the upper ends of the vertical portions being formed to removably receive the spindle, whereby the reel or supply of material may be readily loaded in the cradle and urged into its starting position by the pulling force of the variable tension setting unit. The tension setting unit contains a helical spring connected at one end to the cradle, whereby a predetermined force comparable to the tension to be created in thevmaterial is applied to the carriage in a direction opposite the pull of the material from the supply.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein Fig. 1 is a front elevational view of the apparatus;

Fig. 2 is a side elevational view of the apparatus, portions thereof being removed; and

Fig. 3 is a fragmentary sectional view taken along the line 3--3 of Fig. 1.

Referring now to the drawings, the apparatus includes a cradle l0 which is U-shaped in general contour, one leg 9 of the cradle carrying a stub shaft II, ijournalled in a'bearing I2,

mounted upon a vertical member I4. The other leg I5 01 the cradle supports a housing I6 through which a shaft I'I extends in axial alignment with the shaft II. The outer end of the shaft I1 is journalled in a fixed position bearing I8 mounted u on a vertical member I9 while the inner end of the shaft is journalled in the leg I5.

The shaft I! has a pinion 20 mounted thereon and interengaging a gear 2| of a shaft 22. The pinion 20 and the gear 2| are disposed in a housing I 6, the open end of the housing being closed by a cover 24 which is provided with suitable bearing portions for the outer ends of the shaft 22 and also a shaft 25. The inner ends 01'- the

shafts

22 and 25 are journalled in the leg I5 of the cradle Ill. The shaft 22 has a sprocket 26 mounted thereon which is operatively connected to the shaft 25 through a chain 21 and a sprocket 28, the latter being mounted on the shaft 25. A handle 29 formed integral with the housing I6 projects outwardly therefrom, as illustrated in Fig. 2 and is provided with an indicating point 30 at the outer end thereof.

The shaft 25 extends inwardy through the housing I 6 and has an enlarged portion 3| disposed in the notched upper end 32 of the leg portion I5 of the cradle III and has a recess 38 therein. A spindle 34 is positioned in the hub of a reel 35 of strand material 2', the spindle having a conical portion 28 to cause centering of the spindle in the reel. The spindle is also provided with a pin supporting flange 39 for engagement with the reel. The innermost portion 40 of the spindle is receivable in the recess 33 of the shaft 25 (Fig. 3) when the reel with the spindle is positioned in the cradle ID. The other end of the spindle 24 has a threaded portion 4| upon which a nut 42 is mounted removably securing the spindle within the reel. The extreme outer end 43 of the spindle is removably journalled in a bearing 44 disposed in a notched outer end 45 of the adjacent leg 9 of the cra le It.

A hood-like casing 48 mounted on a suitable support 49 partially houses the reel when loaded in the apparatus, the sides II and Si of the casing being cut away at 52 to allow movement of the cradle with the reel from the loading position shown in broken lines in Fig. 2 to the starting position shown in solid lines in this figure. A latch 53 pivotally supported at 54 on theside of the casing 42 is normally disposed in the position shown in Fig. 2 with its lip portion 55 disposed in the path of the side 9 of the cradle In to hold the cradle with the reel against movement into its loading position. A handle 56 of the latch projects outwardly whereby the operator may readily actuat the latch when it is desirable to unload the empty reel. Arcuate portions 51 of the cut away portions I2 serve to hold the ends of the spindle in the notched ends 22 and 45 of the cradle Ill.

A tension setting unit 6| is mounted on the side 50 of the casing 42,.this unit including a dial 8| graduated to represent variable forces tov be applied to the cradle through a cable 62 connected to the handle 29 by 'a couplin 62. The cable 62 is connected to an inner structure of the unit 60 which includes a helical spring (not shown), the force of which may be varied by moving the dial 6| relative to a pointer 24. The pull on the handle 29 tending to rotate the cradle with the reel counterclockwise into the position shown in solid lines in Fig. 2 will assist in determining the tension to be maintained in the strand material 36 as it is pulled oi! the reel 35.

The apparatus thus far described is used in combination with a unit 66 commercially known as a variable displacement piston pump-motor controlled by a pressure actuated compensator as shown in detail in Patent 2,351,264 to F. T. Har-, rington et al. of June 23, 1944. The unit 6" is adapted-to operate either as a pump or motor depending upon conditions within the fluid line 6! affected by the connection of the unit to the shaft I1 through its output shaft 48 and coupling 69.

Considering now the operation of the apparatus, it will be understood that a full reel 25 of strand material 36 may be readily loaded into the apparatus by first mounting the spindle 24 in the reel and locating the cradle In in the broken line position shown in Fig. 2. The 'reel 3| may be rolled on the support or floor 48'until the spindle is received in the cradle and is properly connected to the shaft 25 through the memvary in these characteristics depending upon the number of insulated electrical conductors assembled in the cable. It is therefore arranged that the tension to be created in the material will be such that during normal operation of the apparatus for medium or heavy reels, the pointer on the handle 29 will register with a point 10 on the side of the casing, this being the vertical position of the cradle.

The unit 66, that is, the pressure-actuated compensator 12 thereof is adjusted before the strand material is pulled off the reel. Therefore, when the pulling operation starts, the reel will be moved with the cradle against the force embodied in the unit until the cradle is-in its operating position with the marks II and III registering. If the diameter of the reel or the lever arm at .the point of take of! of the material from the reel remained unchanged, the'unit 82 perhaps could function in maintaining the predetermined tension in the material. However, the lever arm or the effective diameter of the reel diminishes as each layer of material, is removed therefrom, tending to increase the tension in the material. During rotation of the reel, in a clockwise direction (Fig. 2) the shaft 25 is rotated in the same direction causing its sprocket to move the chain 2lto rotate the shaft 22 in the same direction. The shaft 22 will drive its gear 2| to drive the pinion 20 with the shaft I! in a counterclockwise direction, this driving force continuing through the coupling 88 and the shaft 68 into the unit 66. By prearranged setting of the pressure actuated compensator 12 of the unit '8, it is intended that a predetermined pressure be maintained in the unit. An increase of tension in the material will be translated through the reel and the connecting mechanism to the unit-6i, causing an increase in the pressure in the unit. The compensator 12 will be affected by this increase in pressure in the unit 68 and will convert the unit from a pump to a motor,

V driving the connecting mechanism leading to the bers 3| and 40. By the aid of the handle 29 thecradle with the reel may be moved about the-axes of the shafts I! and 68 into the position shown in solid lines in Fig. 2. The tension to be established in the strand material 36 depends largely upon the size, weight and strength of the material. In the present embodiment of the invention, the material 86 is electrical cable which may reel until the predetermined tension has again been established in the material and the predetermined pressure in the unit 86 has again been established. If for any reason the tension in the material should be reduced, the connecting mechanism between the reel and the unit 66 would affect reduction in the pressure in the unit 66. The'compensator lliwould then cause the unit to speed up its pumping action until the pressure therein has reached the prearranged pressure affecting a drag on the .shaft H, which would be translated through the connecting mechanism to the reel until the slack in the material has been removed and the prearranged tension established.

The tension equalizing apparatus employed in combination with the unit 86 provides for the automatic reduction of the pumpto the constant volume requirement of the power pump at a maintained predetermined ressure. Therefore,

during the. operation of the apparatus, as the I payoff reel decreases'in diameter, it will increase in speed as a result of the constant linear velocity of' the material. The constant volume requirement of the unit 66 will immediately create a pressure rise tendency as aresult of the increased speed of the 'unit. This pressure rise tendency will immediately cause tension control response tovary the compensator 12 of the unit 66 in the direction of decreasing angular displacement with lncreasing speed for a constant volume output at maintained'pressure,

A sudden slackening'of the cable tension permits the reel cradle to swing backward under the pull of the unit 60. This action causes the epicyclic gearing arrangement to speed up the pump temporarily increasing its braking action and slowing down the reel. A sudden tightening of the cable temporarily speeds up the reel. The slightest change in the cable tension instantly starts corrective measures to restore the initial set tension. An arcual displacement of the cradle and reel from the operating position cushions the sudden change in the cable tension. Furthermore, an instantaneous but temporary speed-up or slow-down of the unit 66 takes place to decelerate or accelerate the reel rotation.

To achieve a more sensitive control of light tensions of smaller cables or strands on lighter and smaller reels, it will be advantageous to have the operating position of the cradle l forward of the dead center position with registration of the points 30 and for the medium or heavy reels. As a result, the force of gravity exerted on the reel and cradle when moving in the general direction of the cable pull will assist in providin a softer cushioning effect against overtension in the cable. In addition to this, the accelerating force of gravity will compensate for the tension increase which occurs in the hold back spring of'the unit 60 for the reel cradle. The slower action of the reel cradle retarded by gravity, in its backward travel to take up cable slack prevents over correction when attempting to take up excessive slack. This will prevent sudden and wide swaying of the tension control medium and will therefore indirectly prevent excessive tension in the cable. The gradual decreasing weight of the light reel, due to the paying off of the light cable will permit a rightening of the reel cradle and cause it to assume operating posit ons closer to its vertical or dead center position. This will tend to retain the same reel torque condition from the start to the finish of cable unwinding from the reel.

It is to be understood that the above described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art, which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. An apparatus for equalizing the tensions in materials pulled from rotatable supplies of materials, in combination with a variable displacement fluid piston motor-pump unit having a shaft rotatable about a fixed position axis and a compensator variable with variations of tensions to be created in the materials to maintain a selected variable pressure of the fluid in the motor-pump unit comparable to the tensions to be created in the materials, the apparatus comprising a cradle supported for rocking movement about the axis of the shaft into and out of an operating position, a spindle for supporting a supply of material, mounted for rotation on the cradle, means to connect the supply of material to the spindle whereby the spindle will be rotated with the supply when the material is pulled therefrom, means variable, depending on the tension to be created in the material pulled oif the supply, to normally urge the cradle with the supply in a direction opposite the direction of the pull of the material from the supply, and means operatively connecting the spindle and the shaft whereby movement of the cradle out of its operating position, as a result of variation of the tension in the material from a predetermined tension, will cause variation in the pressure of the fluid in the unit rendering the compensator effective to cause the unit to affect the rotation of the supply to change the tension in the material to the said predetermined tension.

2. An apparatus for equalizing the tensions in materials pulled from rotatable supplies of materials, in combination with a variable displacement fluid piston motor-pump unit having a shaft rotatable about a fixed position axis and a compensator variable with variations of tensions to be created in the materials to maintain a selected variable pressure of the fluid in the motor-pump unit comparable to the tensions to be created inthe materials, the apparatus comprising a cradle supported for rocking movement about the axis of the shaft into and out of an operating position, a spindle for supporting a supply of material, mounted for rotation on the cradle, means to connect the supply of material to the spindle whereby the spindle will be rotated with the supply when the material is pulled therefrom, means variable, depending on the tension to be created in the material pulled off the supply, to normally urge the cradle with the supply in a, direction opposite the direction of the pull of the material from the supply, and a mechanism operatively connecting the spindle and the shaft whereby movement of the cradle in one direction out of the operating position by an increase of the tension in the material will cause the unit to function as a motor to drive the shaft, the mechanism and the spindle with the supply until the tension in the material is reduced to the predetermined tension.

3. An apparatus for equalizing the tensions in materials pulled from rotatable supplies of materials, in combination with a variable displacement fluid piston motor-pump unit having a shaft rotatable about a fixed position axis and a compensator variable with variations of tensions to be created in the materials to maintain a selected variable pressure of the fluid in the motor-pump unit comparable to the tensions to be created in the materials, the apparatus comprising a cradle supported for rocking movement about the axis of the shaft into and out of an operating position, a spindle for supporting a supply of material, mounted for rotation on the cradle, means to connect the supply of material to the spindle whereby the spindle will be rotated with the supply when the material is pulled therefrom, means variable, depending on the tension to be created in the material pulled off the supply, to normally urge the cradle with the supply in a direction opposite the direction of the pull of the material from the supply, and a mechanism operatively connecting the spindle and the shaft whereby movement of the cradle in one direction from the operating position by the said pulling means as a result of a decrease in tension in the material will cause the unit to function as a pump creating a drag on the shaft, the connecting mechanism, the spindle and the material until the tension in the material is returned to the predetermined tension.

4. An apparatus for equalizing the tensions in materials pulled from rotatable supplies of materials, in combination with a variable displacement fluid piston motor-pump unit having a shaft rotatable about a fixed position axis and a compensator variable withvariations of tensions to 7 be created in the materials to maintain a selected variable pressure of the fluid in the motor-Dump unit comparable to the tensions to be created in the materials, the apparatus comprising a U- shaped cradle supported for rocking movement between a loading position and the operating position'about the axis of the shaft into and out of an operating position and having spindle supporting recesses in the upperends thereof, a spindle, for supporting a supply of material, removably mounted in the recesses of the cradle, means toconnect the supply of material to the spindle whereby the spindle will be rotated with the supply when the material is pulled therefrom, means variable, depending on the tension to be created'in the material pulled off the supply, to

normally urge the cradle with the supply in a direction opposite the direction of the. pull-oi the material from the supply. and meansopera tively connecting the spindle and the shaft whereby movement of the cradle out'of its operating position, as a result of variation of the tension in the material from a predetermined tension,

will, causevariation in the pressure of the fluid 4 in the unit rendering the compensator effective ,to causethe unit to affect the rotation of the supply to change the tension in the material to the said predetermined tension.

'5. An apparatus for equalizing the tensions in materials pulled'from rotatable supplies 'of materials, in combination with a variable displacementfluid piston motor-pump unit having a shaft rotatable abouta fixed position axis and a compensator variable with variations -'of tensions to be created in the materials to maintain a selected variable pressure of the fluid in the motor-pumpumt comparable to the tensions to be created in the materials, the apparatus comprising a U-shaped cradle supported for rocking' movement between a loading position and the operating position about the axis of the shaft into and out of an operating positionand having spindle supporting recesses in the upper ends thereof, a spindle, for supporting a supply of pending on the tension to be created in the material pulled off the supply, to normally urge the cradle with the supply in a direction opposite the direction of the pull of the material from the supply, and means operatively connecting the spindle and the shaft whereby movement of the in materials pulled from rotatable supplies of materials,'in combination with a variable displacement fiuidpiston motor-pump unit having a shaft rotatable about a fixed position axis and a compensator, variable with variations of tensions to be created in the materials to maintain a selected variable pressure of the fluid in the motor-pump unit comparable to the tensions to be created in the materials, the apparatus comprising a U-shaped cradle supported for rocking movement. between a leading position and the operating position about the axis of the shaft intoand out of,an operating position and having spindle supporting recesses in the upper ends thereof, a spindle, for supporting a supply of material, removably mounted in the recesses of the cradle, a hood having arcuate portions to effectively close the recesses to maintain the spindle therein, a latch carried by the hood to limit the cradle from movement into the loading position, means to connect the supply of material to the spindle whereby the spindle will be rotated with the supply when the material is pulled therefrom, means variable, depending on the tension to be created in the material pulled oil the supply, to normally urge the cradle with the supply in a direction oppositethe direction of the pull of the material from the supply, and means operatively connecting the spindle and the shaft whereby movement of the cradle out of its operating position, as a result of variation of the tension in the material from a predetermined tension, will cause variation in the pressure of the fluid in the unit rendering the compensator effective to cause the unit to affect the rotation of the supply to change the tension in the material to the said predetermined tension.-

- was A. soooa'r.

REFERENCES crrEn The following references areof record in the file of this patent:

UNITED STATES PATIENTS Number Name Date 2,206,246 Bannister July 2, 1940 2,351,264 Harrington June 13, 1944