US2775263A - Tension-responsive control - Google Patents

Description

Dec. 25, 1956 D. B. RUSH 2,

TENSION-RESPONSIVE CONTROL Filed July 9, 1953 F Z. INVENTOR.

ATTOF/VFK United States Patent TENSION -RESPONSIVE CONTROL Dale B. Rush, Columbus, Ind., assignor, by mesne assign ments, to The Reliance Electric and Engineering Company, Cleveland, Ohio, a corporation of Ohio Application July 9, 1953, Serial No. 367,043

16 Claims. (Cl. 139-110) The present invention relates to a drive for a storage roll for flexible material, and the primary object of the invention is to provide a mechanism which, in response to tendencies toward variation in a condition in a length of such material, such as, for instance, tension, will automatically vary the speed at which such a storage roll is driven, either for winding or unwinding of the material, in order to maintain such condition against substantial effective variation.

The invention is particularly designed for use, and has been illustrated and will be described in connection, with a loom beam let-off drive; and particularly it is an object of the invention to place the shiftable element of a variable-speed transmission, connected to drive the unwind roll of a loom, under the domination of the conventional Whip roll of a loom.

To the accomplishment of the above and related objects, my invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific construction illustrated and described, so long as the scope of the appended claims is not violated.

Fig. l is a side elevation of a control constructed in accordance with the present invention, assembled with a beam let olf mechanism, fragmentarily and somewhat diagrammatically illustrated; and

Fig. 2 is an end elevation thereof.

Referring more particularly to the drawings, it will be seen that I have shown a frame in which is journalled a shaft 11 upon which is carried the conventional unwind roll 12, familiarly found in loom construction. A mass 13 of flexible material such as, for instance, warp yarns is shown wound upon the roll 12; and the parts are shown, in solid lines, at a time in the cycle of the suggcsted machine, very shortly after the initiation of an unwinding operation. It will be seen that the material is led frornthe mass 13 in a section 14 which is always tangent to the effective surface of the mass 13 (sometimes referred to as the eifective surface of the storage roll) and, after passing over the whip roll, later to be described in detail, extends in a run 16 to mechanism, suggested at 15, through which the material is forwarded at a constant lineal velocityto a point of use (not shown).

A trackway 17 which may take the form of a pair of parallel,horizontal racks, is supported upon the frame 10 (which may be a part of the conventional loom frame) above the axis of the roll 12, said trackway extending in a direction transverse to the axis. Wheels 18, which may be cogs, as shown, support an axle 19 upon said trackway 17 for movement therealong; and a roller 20 is supported upon the axle 19 for free rotation about the axis thereof. The assembly 18, 19, 20 comprises, of course, the conventional whip roll.

. An arm 21 is mounted for oscillation about a fixed axis 22 which preferably coincides with the axis of the shaft 11. In the illustrated embodiment. of the invention, said .arm is actually mounted upon a projection of said shaft; the arm being free, however, for oscillation with said shaft. The arm 21 projects into proximity with the trackway 17 and, at its outer end, is bifurcated to define a slot 23, elongated in the direction of length of the arm, and freely receiving a projecting end of the axle 19. Thus, the roll 20 is operatively connected to the arm 21, whereby movement of said roller along the trackway 17 will be accompanied by oscillation of the arm 21 about its journal axis 22. A cable 24 has one end anchored to the arm 21, passes over a pulley 25, and supports a weight 26, whereby said arm is yieldably biased to hold the roller 20 at the left-hand end of the trackway 17, as viewed in Fig. l.

It will be seen that the roller 20 bears against the inner surface of the material 14 within that sector which is defined between the current point of tangency .of section 14 with the effective surface of the roll, and a vertical plane including the axis of the roll 12.

A shaft, indicated at 27, is driven through suitable means (not shown) at a constant ratio with respect to the material-forwarding means 15. A bevelled gear 28 on the shaft 27 meshes with a bevelled gear 29 on a shaft 30 suitably supported upon an axis parallel with the axis of the shaft 11; and a first resiliently expansible V-pulley, indicated generally by the reference numeral 31, is mounted to rotate upon the axis of the shaft 30.

The pulley 31 comprises a coned. disc 32 axially fixed with respect to the shaft 30 and a mating coned disc 33 mounted for axial reciprocation relative to the shaft 30, and resiliently urged toward the disc 32 by a conventional spring unit 34.

A sprocket 35 is fixed to the shaft 11 and is drivingly connected by a chain 36, with a sprocket 37 on the output shaft 38 of reducing gear 39. The input shaft 40 of the gear 39 carries a resiliently expansible V-pulley, indicated generally by the reference numeral 41, and comprising a coned disc 42 fixed to the shaft 40 and a mating coned disc 43 axially shiftable relative to the shaft 40 and resiliently urged toward the disc 42 by a conventional spring unit 44.

Upon a bracket 45, mounted in a horizontal plane between the axes of the pulleys 31 and 41, a bearing 46 pivotally supports the intermediate portion of a bellcrank lever 47 for oscillation about an axis parallel with, but oflfset from, the plane common to the axes of the pulleys 31 and 41. One arm 48 of the lever 47 supports a jack-shaft 49 upon which are mounted two fixed-di ameter pulleys 56 and 51. The pulleys 50 and 51 are connected to rotate together; and this connection is most conveniently provided by drivingly connecting both pulleys to the jack-shaft 49. A belt 52 provides a driving connection between the pulley 31 and the pulley 50, while a belt 53 provides a driving connection between the pulleys 51 and 41. i

To the other arm 54 of the bell-crank lever 47 is connected one end of a link 55, the other end of which ispivotally connected, as at 56, at an intermediate point in the arm 21.

When a loaded storage roll 12 is mounted in the frame 10, the arm 21 under the influence of the weight 26, will be in its extreme counter-clockwise position, in which the roller 20 on the axle 19 will be at the extreme left-hand end of the track 17. The end of the material on the roll will now be carried over the whip roll 20 and to the forwarding means 15, and thence to a point of use. When the forwarding means 15 is energizedythe shaft 27 will likewise be driven. The parts are so proportioned and designed that, under these conditions, the roll 12 will be driven at an angular velocity such as to maintain a predetermined degree of tension in the run 16. As material is withdrawn from the mass 13, the effective diameter of the unwind roll 12 is decreased. Since the roll is turningat a constant angular velocity under the driving influence of the shaft 27 through the variable speed transmission comprising the pulley 21, the pulleys 5t) and 51 and the pulley 41, there is a tendency for the tension in the run 16 of the material to increase. At the same time, the point of tangency of the section 14 with the effective surface of the mass 13 moves gradually toward the right, as viewed in Fig. l. The combined effect of these two tendencies will be to increase the horizontal component of the force exerted upon the roller 20 by the material; whereby the tendency of the weight 26 is overcome, and the whip roll 20 will be moved toward the right along the trackway 17. Thereby, through the link 55, the bell-crank lever 47 will be turned in a clockwise direction. Such movement of the lever will tend to move the jack-shaft 49 toward the pulley 31 and away from the pulley ll. This will tend to produce slack in the belt 52; but the spring unit 34 will, of course, move the disc 33 toward the disc 32, thus squeezing the belt 52 outwardly between the discs 32 and 33, to increase the effective diameter of the pulley 31. At the same time, as the pulley Slmcves away from the pulley 41, the belt 53 will be pulled more deeply into the groove between the discs 42 and 43, forcing the disc 43 away from the disc 42, against the tendency of the unit 44, and decreasing the effective diameter of the pulley 41. The increase in the effective diameter'of the pulley 31 will, of course, result in increasing the speed at which the jack shaft 49 will be driven; and the decrease in the effective diameter of the pulley 41 will result in increasing the speed of the shaft relative to the speed of the jack-shaft 49. Thus, as the whip roll 20 moves gradually toward the right, as viewed in Fig. l, the speed of the shaft 11 will be gradually increased. Obviously, the proportions of the several parts can be so constructed that the increase in the speed of the shaft 11 will precisely compensate for the diminution in the effective diameter of the mass 13, to maintain constant tension upon the run 16, which is continuously forwarded, at a constant lineal speed, by the forwarding means 15.

It will be clear that the illustrated mechanism could be used, also, in a winding operation. In such case, the material-forwarding means 15 would, of course, move the material toward, instead of away from, the storage roll 12 at constant velocity; and the control mechanism would operate to reduce the angular velocity of the roll 12, progressively, under the domination of variation, or rather tendencies toward variation, in the tension in the section 16 of the material. The whip roll 20 would move progressively from its dotted line position toward its solid line position,

as viewed in Fig. 1, to move the arm 21 progressively in a counter-clockwise direction, during such winding opera tion. Thereby, the lever 47 would be progressively moved in a counter-clockwise direction to shift the jack-shaft 49 away from the pulley 31 and toward the pulley 41, to reduce, progressively, the effective diameter of the pulley 31 and to increase, progressively, the effective diameter of the pulley 41.

I claim as my invention:

1. Means for automatically controlling the rate of rotation of a storage roll for flexible material, comprising in combination with such a roll, a length of flexible material wound on said roll, means for forwarding said material relative to said roll, rotary means driven at a constant ratio with respect to. said forwarding means, variable-speed transmission means connecting said rotary means to drive said roll and comprising an input shaft connected to be driven from said rotary means, an output shaft connected to drive said roll, an expansible V-pulley on each of said shafts, edge-active belt means providing a driving connection between said pulleys, and an element shiftable to vary inversely the effective diameters of said pulleys, an arm mounted for oscillation about a fixed axis in a common plane with the axis of said roll, means operatively engaging said arm and bearing against the inner surface of said material at a point within the sector defined between the current point of tangency of said material with the effective surface of said roll and a plane including the axis of said roll and normal to the plane of movement of said material, means yieldingly resisting movement of the arm in response to an increase in the tension on that reach of the material between the forwarding means and said means bearing against the material, and means connecting said arm to shift said shiftable element.

2. Means for automatically controlling the rate of rotation of a storage roll for flexible material comprising, in combination with such a roll, a length of flexible material wound on said roll, means for forwarding said material at constant lineal velocity, rotary means driven at a constant ratio with respect to said forwarding means, variable-speed transmission means connecting said rotary means to drive said roll, said transmission means including an element shiftable oppositely to vary oppositely the output speed of said transmission means, an arm mounted for oscillation about the axis of said roll, a trackway spaced from said axis, disposed in a plane substantially parallel with said axis and extending in a direction transverse to the direction of length of said axis, a bearing member supported on said trackway for movement therealong, bearing against the inner surface of said material at a point within the sector defined between the current point of tangency of said material with the effective surface of said roll and a plane including the axis of said roll and normal to the plane of movement of said material, said bearing member being operatively connected with said arm, said arm being yiel-dably biased away from said normal plane and toward said current point of tangency, and means connecting said arm to shift said shiftable element.

3. Means for automatically controlling the rate of rotation of a storage roll for flexible material comprising, in combination with such a roll, a length of flexible material wound on said roll, means for forwarding said material at constant lineal velocity, rotary means driven at a constant ratio with respect to said forwarding means, a pulley driven by said rotary means, a second pulley spaced from said first-named pulley and mounted on an axis parallel with the axis of said first pulley, a jack shaft, means supporting said jack shaft between said first and second pulleys upon an axis parallel with the axes of said pulleys for bodily movement toward and away from said first pulley, a third pulley and a fourth pulley drivingly mounted on said jack shaft, a first belt trained over said first pulley and over said third pulley, a second belt trained over said second pulley and over said fourth pulley, one of the pulleys engaged by each of said belts being an expansible V-pulley, means connecting said second pulley to drive said roll, an arm mounted for oscillation about the axis of said roll, a trackway spaced from said axis, disposed in a plane substantially parallel with said axis and extending in a direction transverse to the direction of length of said axis, a bearing member supported on said trackway for movement therealong, bearing against the inner surface of said material at a point within the sector defined between the current point of tangency of said material with the effective surface of said roll and a plane including the axis of said roll and normal to the plane of movement of said material, said bearing member being operatively connected with said arm, said arm being. yieldably biased away from said normal plane and toward said current point of tangency, and means connecting said arm to shift said jack shaft.

4. The control means of claim 3 in which said means supporting said jack shaft comprises a lever mounted to swing upon an axis parallel with said pulley axes and eccentric with respect to said jack shaft axis.

5. The control means of claim 3 in which said first pulley and said second pulley are resiliently-expansible V-pulleys and said third and fourth pulleys are fixeddiarneter V-pulleys.

'6. Means for automatically controlling the rate of rotal l v tion of a storage roll for flexiblematerial comprising, in combination with such a roll, a length of flexible material wound on said roll, means for forwarding said material at constant lineal velocity, rotary means driven at a constant ratio with respect to said forwarding means, a resiliently-expansible V-pulley driven by said rotary means, a second resiliently-expansible V'pulley spaced from said first-named pulley and mounted on an axis parallel with the axis of said first pulley, a jack shaft positioned between said first and second pulleys upon an axis parallel to the axes of said pulleys, a third pulley and a fourth pulley drivingly mounted on said jack shaft, a first belt trained over said first pulley and over said third pulley, a second belt trained over said second pulley and over said fourth pulley, an arm mounted for oscillation about the axis of said roll, a trackway spaced from said axis, disposed in a plane substantially parallel with said axis and extending in a direction transverse to the direction of length of said axis, a bearing member supported on said trackway for movement therealong, bearing against the inner surface ofsaid material at a point within the sector defined between the current point of tangency of said material with the effective surface of said roll and a plane including the axis of said roll and normal to the plane of movement of said material, said bearing member being operatively connected with said arm, said arm being yieldably biased away from said normal plane and toward said current point of tangency, means shiftable oppositely to expand one or the other of said resiliently-expansible V-pulleys selectively while permitting contraction of the other, means connecting said arm to shift said shiftable means, and means connecting said second pulley to drive said roll.

7. The combination with a loom beam let-off including an unwind roll, a whip roll supported to travel on a substantially horizontal trackway, a length of flexible material wound on said unwind roll, and means for withdrawing said material from said unwind roll, said material ex tending from said unwind roll over said whip roll and thence to said withdrawing means and said whip roll having its axis always within the sector between the current point of tangency of said material with the effective surface of said unwind roll and a substantially vertical plane including the axis of said unwind roll, of a tension-responsive drive for said unwind roll comprising rotary means driven at a constant ratio with respect to said withdrawing means, variable-speed transmission means connecting said rotary means to drive said unwind roll and comprising an input shaft connected to be driven from said rotary means, an output shaft connected to drive said roll, an expansible V-pulley on each of said shafts, edge-active belt means providing a driving connection between said pulleys, and an element shiftable to vary inversely the effective diameters of said pulleys, and means connecting said whip roll to shift said shiftable element to increase the output speed of said transmission means as said whip roll travels toward said vertical plane.

8. The combination of claim 7 in which said means connecting said whip roll to shift said shiftable element comprises an arm mounted for oscillation about the axis of said unwind roll, means yieldably biasing said arm toward said current point of tangency and away from said vertical plane, said Whip roll having a driving connection with said arm, and means providing a driving connection between said arm and said shiftable element.

9. The combination with a loom beam let-off including an unwind roll, a whip roll supported to travel on a substantially horizontal trackway, a length of flexible material wound on said unwind roll, and means for withdrawing said material from said unwind roll, said material extending from said unwind roll over said whip roll and thence to said withdrawing means and said whip roll having its axis always within the sector between the current point of tangency of said material with the effective surface of said unwind roll and a substantially vertical plane including the axis of said unwind roll, of a tension-responsive drive for said unwind roll comprising rotary means driven at a constant ratio with respect to said withdrawing means, variable-speed transmission means comprising a pulley driven by said rotary means, a. second pulley spaced from said first-named pulley and mounted on an axis parallel with the axis of said first pulley, a jack shaft, means supporting said jack shaft between said first and second pulleys upon an axis parallel with the axes of said pulleys for bodily movement toward and away from said first pulley, a third pulley and a fourth pulley drivingly mounted on said jack shaft, a first belt trained over said first pulley and over said third pulley, a second belt trained over said second pulley and over said fourth pulley, one of the pulleys engaged by each of said belts being, an expansible V-pulley, an element shiftable oppositely to vary oppositely the output speed of said transmission means, an arm mounted for oscillation about the axis of said unwind roll, means yieldably biasing said arm toward said current point of tangency and away from said vertical plane, said whip roll having a driving connection with said arm, means providing a driving connection between said arm and said shiftable element, means connecting said shiftable element to shift said jack shaft toward and away from said first pulley, means connecting said whip roll to shift said shiftable element to increase the output speed of said transmission means as said whip roll travels toward said vertical plane, and means connecting said second pulley to drive said unwind roll.

10. The combination of claim 9 in which said means supporting said jack shaft comprises a lever mounted to swing upon an axis parallel with said pulley axes and eccentric with respect to said jack shaft axis.

11. The combination of claim 9 in which said first pulley and said second pulley are resiliently-expansible V-pulleys and said third and fourth pulleys are fixeddiarneter V-pulleys.

12. The combination with a loom beam let-off including an unwind roll, a whip roll supported to travel on a substantially horizontal trackway, a length of flexible material wound on said unwind roll, and means for Withdrawing said material from said unwind roll, said material extending from said unwind roll over said whip roll and thence to said withdrawing means and said whip roll having its axis always within the sector between the current point of tangency of said material with the effective surface of said unwind roll and a substantially vertical plane including the axis of said unwind roll, of a tension-responsive drive for said unwind roll comprising rotary means driven at a constant ratio with respect to said withdrawing means, variable-speed transmission means comprising a pulley driven by said rotary means, a second pulley spaced from said first-named pulley and mounted on an axis parallel with the axis of said first pulley, a jack shaft, means supporting said jack shaft between said first and second pulleys upon an axis parallel with the axes of said pulleys for bodily movement toward. and away from said first pulley, a third pulley and a fourth pulley drivingly mounted on said jack shaft, a first belt trained over said first pulley and over said third pulley, a second belt trained over said second pulley and over said fourth pulley, one of the pulleys engaged by each of said belts being an expansible V-pulley, an element shiftable oppositely to vary oppositely the output speed of said transmission means, means connecting said shiftable element to shift said jack shaft toward and away from said first pulley, means connecting said whip roll to shift said shiftable element to increase the output speed of said transmission means as said Whip roll travels toward said vertical plane, and means connecting said second pulley to drive said unwind roll.

13. The combination of claim 12 in which said means supporting said jack shaft comprises a lever mounted to swing upon an axis parallel with said pulley axes and eccentric with respect to said jack shaft axis.

14. The combination of claim 12 in which said first 7 pulley and'said second pulley are resiliently-cxpansible V-pulleys and said third and fourth pulleys are fixeddiameter 'V-pulleys.

15.'The combination with a loom beam let-off including an unwind roll, a whip roll supported to travel on a substantially horizontal trackway, a length of fiexible material wound on said unwind roll, and means for withdrawing said material from said unwind roll, said material extending from said unwind roll over said whip roll and thence to said withdrawing means and said whip roll having its axis always within the sector between the current point of tangency of said material with the efiective surface of said unwind roll and a substantially vertical plane including the axis of said unwind roll, of a tension'respon sive drive for said unwind roll comprising rotary means driven at a constant ratio with respect to said withdrawing means, a first resiliently-expansible ll-pulley driven by said rotary means, a second resiliently-expansible V-pulley spaced from said first pulley and mounted on an axis parallel with the axis of said first pulley, a bell-crank lever intermediately supported to swing about an axis parallel with, but offset from the plane common to the axes of said pulleys, a jack shaft carried by one arm of said lever for rotation about an axis disposed between the axes'of said pulleys and parallel therewith, two fixed diameter pulleys, mounted on said jack shaft and connected for joint rotation, a belt providing a driving connection between said first pulley and one of said jack shaft pulleys, a second belt providing a driving connection between the other of said jack shaft pulleys and said second pulley, means providing a driving connection between said second pulley and said unwind roll, and means providing a driving connection between said whip roll and the other arm of said lever to shift said jack shaft toward said first pulley as said whip roll travels toward said vertical plane.

16. The combination With a loom beam let-oif including an unwind roll, a whip roll supported to travel on a substantially horizontal trackway, a length of flexible material wound on said unwind roll, and means for withdrawing said material from said unwind roll, said material extending from said unwind roll over said whip roll and thence to said withdrawing means and said whip roll having its axis always within the sector between the current point of tangency of said material with the effective surface of said unwind roll and a substantially vertical plane including the axis of said unwind roll, of a tension-responsive drive for said unwind roll comprising rotary means driven at a constant ratio with respect to said withdrawing means, a first resiliently-expansible V-pulley driven by said rotary means, a second resiliently-expansible V-pulley spaced from said first pulley and mounted on an axis parallel with the axis of said first pulley, a bell-crank lever intermediately supported to swing about an axis parallel with, but offset from the plane common to the axes of said pulleys, a jack shaft carried by one arm of said lever for rotation about an axis disposed between the axes of said pulleys and parallel therewith, two fixeddiameter pulleys, mounted on said jack shaft and connected for joint rotation, a belt providing a driving connection between said first pulley and one of said jack shaft pulleys, a second belt providing a driving connection between the other of said jack shaft pulleys and said second pulley, means providing a driving connection between said second pulley and said unwind roll,-an arm mounted for oscillation about the axis of said unwind roll, said whip roll being operatively connected to said arm to shift the same as said whip roll travels on said trackway, means yieldably biasing said arm toward said current point of tangency and away from said vertical plane, and a link connecting the other arm of said lever with an intermediate point on said oscillable arm.

ReferenccsCited in the file of this patent UNITED STATES PATENTS 2,103,200 Brown Dec. 21, 1937 2,175,551 Perry Oct. 10, 1939 2,398,547 Moessinger Apr. 16, 1946 2,581,328 Malcom Jan. 1, 1952 2,608,741 Reeves Sept. 2, 1952 2,664,724 Lambach Jan. 5, 1954 FOREIGN PATENTS 235,025 Switzerland Nov. 15, 1944

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