US3559907A

US3559907A - Mechanisms for reeling wire, tape and the like

Info

Publication number: US3559907A
Application number: US718302A
Authority: US
Inventors: Roland William Gordo Somervell
Original assignee: S Davall and Sons Ltd
Current assignee: S Davall and Sons Ltd
Priority date: 1967-04-28
Filing date: 1968-03-18
Publication date: 1971-02-02
Anticipated expiration: 1988-02-02
Also published as: FR1565056A; GB1234021A

Abstract

A magnetic wire recording device with two sets of coaxial reels. One reel in each set is positively driven while the other is driven via a slipable clutch so arranged as to maintain constant tension in the wire. One set of reels winds while the other set rewinds, and the drive is automatically reversed by a switch which operates when an unwinding reel becomes empty.

Description

United States Patent Inventor Roland William Gordon Somervell Beaconslield, England Appl. No. 718,302 Filed Mar. 18, 1968 Patented Feb. 2, 1971 Assignee S. Davall & Sons Limited Middlesex, England a British Company Priority Apr. 28, 1967 Great Britain 19690/67 MECHANISMS FOR REELING WIRE, TAPE AND THE LIKE Primary ExaminerGeorge F. Mautz Attorney-Mawhinney & Mawhinney ABSTRACT: A magnetic wire recording device with two sets of coaxial reels. One reel in each set is positively driven while 13 Claims 16 Drawing Figs the other is driven via a slipable clutch so arranged as to main- U.S. Cl 242/54.1, tain constant tension in the wire. One set of reels winds while 242/57, 242/158.5, 242/193 the other set rewinds, and the'drive is automatically reversed Int. Cl Gllb /32, by a switch which operates when an unwinding reel becomes B65h /32, B65h 54/78 empty.

MECHANISMS FOR REELING WIRE. TAPE AND THE LIKE This invention relates to mechanisms for reeling wire. tape or like extended members.

The invention provides a mechanism for reeling wire. tape or a like extended member off from a reel onto another reel, in which the arrangement is such that the maximum diameter at which the extended member is wound onto one rcel is less than the minimum diameter at which the extended member is wound off the other reel, reversible drive means are coupled to the said one reel and via a slipable clutch to the said other reel which is acted upon by brake means, the drag torque of the brake means exceeding the drive torque of the slipable clutch for drive in the sense in which the extended member is wound onto the said one reel from the said other reel and the drive torque of the slipable clutch exceeding the drag torque of the brake means for drive in the opposite sense.

Preferably the two reels are coaxially mounted.

Preferably the slipable clutch and preferably also the brake means comprise stepped helical coil springs acting between the reels and between a supporting frame member and the said other reel respectively.

Preferably the slipable clutch comprises a stepped helical coil spring the larger diameter end of which engages the inwardly facing surface of a bore in the said one reel and the smaller diameter end of which engages around a cylindrical surface on the said other reel.

Preferably the brake means comprises a stepped helical coil spring of opposite hand to that comprising the slipable clutch, the smaller diameter end of which stepped helical coil spring engages around another cylindrical surface on the said other reel and the larger diameter end of which engages the inwardly facing surface of a bore in the frame member.

Preferably the mechanism is incorporated in a magnetic wire recording mechanism and preferably means are provided for automatically reversing the direction of drive to the said one reel after a predetermined amount of reeling from one reel onto the other has taken place.

The invention also provides guide pulleys for guiding wire tape or a like extended member off from one reel onto a coaxially mounted reel, which guide pulleys are mounted on a single platform reciprocated to cause the extended member to form into, or run easily from, even axially extending layers on the reels.

Preferably the setting of relative location and/or orientation of the platform and reels is adjustable for applying correction to layering faults.

The invention also provides an automatic switching device in a mechanism for reeling wire, tape or a like extended member comprising a switch member on a reel which switch member is biassed into a switch actuating position out of which the switch member is held against the bias by extended member wound on the reel, whereby when the last layer of extended member unwinds from holding the switch member as aforesaid, the switch member is released.

Preferably, where wire is wound off from one reel onto another reel, the automatic switching device is arranged to reverse the drive to the reels when the switch member is released.

The invention also provides an electrical switching device comprising an operating member and an operated member both of which are arranged and biassed to be movable over center with a toggle action between off and on conditions, and coupling between the members arranged so that the operating member only acts upon the operated member to move the operated member over center after the operating member has moved over center.

A specific construction of magnetic wire recording device embodying the invention will now be described by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a sectional view, partly diagrammatic, of part of the mechanism;

FIG. 2 is a diagrammatic perspective view of a stopped helical coil spring;

FIG. 3 is a side elevation of the mechanism with some parts omitted;

FIG. 4 is a plan view of the mechanism with some parts omitted;

FIGS. 5, 6 and 7 are diagrammatic plan views of part of the mechanism shown respectively in three different conditions;

FIG. 8 is a diagrammatic side view of the part shown in FIGS. 5, 6 and 7 and FIGS. 9 to 16 are diagrammatic representations of wire layering conditions on the four reels of the mechanism of this example.

In this example the magnetic wire recording device 11 comprises four reels 12. 13. 14. 15 mounted coaxially on a shaft 16. In this example the arrangement of four reels provides two magnetic wire reeling devices which operate simultaneously from one reversible drive coupled to gear wheel 17.

Magnetizable wire 18 stored on reels l2 and 13 is guided off one reel onto the other by two

pulleys

19, 21 mounted on a tilted platform 22 (see FIGS. 3 and 4). The platform 22 also supports three recording heads 23 past which the wire is guided. The same platform 22 also supports

guide pulleys

24, 25 for the wire 26 of the

reels

14, 15 and three recording heads 27 for this lower reeling mechanism.

The

pulleys

19, 21 are mounted on a plate 28 secured to the platform 22 so as to be laterally adjustable on the platform 22 as indicated by the arrows 29 in FIG. 4. The recording heads 23 are also mounted on the plate 28 and the position of each recording head is adjustable on the plate 28 as indicated by the arrows 31 in FIG. 4. This adjustability of the heads 23 on the plate is necessary for securing correct location of the heads in relation to the wire 18.

The

pulleys

24, 25 and recording heads 27 are similarly mounted on a plate 32 also secured to the platform 22 so as to be laterally adjustable in the same manner as plate 28.

The platform 22 is pivoted on a shaft 33 and is coupled by means of a bridge 34 to a cam follower block 35. A spherical roller 36 is rotatably mounted on a spigot 37 projecting from the cam follower block 35. The roller 36 is acted upon by heart cam 38 to produce a cycled tilting of the platform 22 the extent of which tilting is indicated by arrows 39 in FIG. 3. Adjustment of the mean setting of tilt of the platform 22 is achieved by the adjustable relative location of the cam follower block 35 and the bridge 34. As shown in FIG. 3, the block 35 is pivoted at 41 to the bridge 34 and clamped by screws 42 received through slots in the bridge 34. The extent of the adjustment so provided of the mean tilt of the platform 22 is indicated by arrows 43 in FIG. 3.

The operation of the platform 22 and the effect of the several adjustments is described more fully below with reference to FIGS. 9 to 16.

As may best be seen in FIG. 1, the reel 12 is of larger diameter than the reel 13 and the arrangement is such that the diameter at which wire 18 reels onto, or off from reel 12 is always greater than that at which the wire 18 reels onto, or off from reel 13. The reel 13 is keyed to the drive shaft 16 by pin 44 while the reel 12 is mounted on bearings 45 for free rotation on the shaft 16.

The slipable clutch connection between the reel 13 and the reel 12 is provided by a right handed stepped helical coii spring 46. Braking between the reel 12 and a frame member 47 is provided by a left handed stepped helical coil spring 48. The formation of these stepped helical coil springs is shown in FIG. 2 which is a diagrammatic perspective view of the left handed spring 48. The springs are formed with a strong half 49 and a light half 51. In manufacture, the light half is formed by skimming off part of a uniform strength spring and it is an effect of this that the diameter of the lightened half reduces a as shown. In the diagrammatic rows of rectangles representing the springs in FIG. 1, the strong halves are represented by the larger rectangles.

The strong half of spring 46 engages with the internal surface of a bore 52 of reel 13 while the light half engages around 62 biasesthe dog 61 towards the position shown in cylindrical surface 53 provided on the reel 12. The strong half of spring 48 engages with the internal surface of a bore 54 formed in a projection from the frame 47 and the light halfengages around cylindrical surface 55 provided on the reel 12 on the axially opposite side to the cylindrical surface 53. When the shaft is rotated in the sense of arrow G. wire is wound off from the larger reel 12 onto the smaller reel 13.

The

reels

14, 15 are provided with a right handed stepped helical coil spring 56 and a left handed stepped helical coil spring 57. The arrangement is the inverse of that of reels 12. 13 as may be seen from FIG. 1, except that for drive to the shaft 16 in the sense of the arrow G wire 58 is wound off from the smaller reel 14 and onto the larger reel 15. In this condition, the mechanism of the

upper reels

12, 13 is recording while that of the

lower reels

14, 15 isrewinding. When the drive is reversed, the conditions of the two mechanisms are exactly reversed and the mechanism of the

upper reels

12, 13 is rewinding while that of the lower reels I4, 15 is recording.

Reversal of the drive is triggered automatically when one of the smaller reels becomes empty. The mechanism for this effect is illustrated in FIGS. 5 to 8 and will be described for the reel 13 only.

Pivotally mounted at 59 on the reel 13 is a dog 61. A spring FIGS. 6 and 7 in which the end 63 of the dog moves in a path to engage against a pivoted tig 64. Fixed to the dog is a loop of stiff wire 65 which is held down close against the surface of the reel 13 by the wire 18 wrapped round the reel as shown in FIG. 5. When the loops 65 is held down in this way the dog 61 is held against the bias of spring 62 out of the path in which it engages the tig 64.

However, when the loop 65 is released on the unwinding of the last loop of wire 18, the dog 61 strikes the tig 64 and pivots .the tig 64 as illustrated in FIGS. 6 and 7.

The tig 64 is biassed by a toggle spring (not shown) so that once moved over center by the dog 61 it completes the movement to the FIG. 7 position with a snap action. The tig 64, thus moved, operates a reversing microswitch 66. However, to avoid or reduce the possibility of the switch contacts teetering a differential land cam 67 is interposed between the tig 64 and the microswitch operating button 68. The effect of this is for the toggle switch action of the tig 64 to double the toggle action of the button 68 inherently built into the microswitch. The differential land cam 67 has three portions 67a, 67b and 67c. When the button 68 is engaged by portion 67a, the microswitch is in one condition, say off. When the button 68 is engaged by portion 67c, the microswitch is on. When the button 68 is engaged by the intermediate portion 67b the microswitch remains in the state it was previously in, Le. the movement of the button 68 caused either as it rides up from portion 67 a to 67b or as it rides down from portion 67c to portion 67b of the cam 67 is insufficient to move the microswitch toggle overcenter. The engagement of the button 68 by this intermediate portion 67b is arranged to occur during the overcenter movement of the tig 64. Thus, switching of the microswitch 66 only occurs after the tig 64 has gone over center so that the microswitch is rushed through the dangerous low pressure instant just before breaking occurs. As may be seen from FIG. 8, the tig 64 and the cam 67 are mounted on a spindle 69. A second tig, not shown is mounted on this spindle for actuation by a corresponding dog on the reel 14. The dog on the reel 14 faces in the opposite sense to the dog 61, so that the tigs and cam 67 are reset and rereversal takes place when the reel 14 becomes empty of wire.

The wire is arranged so that there is always more wire on the larger reels l2 and 15 than on the

smaller reels

13 and 14. In this way reversal is always initiated by the emptying of one of the smaller reels before one of the larger reels becomes empty.

Since the dogs cannot operate the tigs in the opposite sense I to that intended, it is not possible to provide for independent external reversal. The difficulty may be overcome by coupling the external reversing switch to the tigs 64 so that they are also switched over. Alternatively the dogs or tigs or both for each reelmay be doubled.

The operation of the reeling mechanism when drive is applied to the shaft 16 and, via reduction gears, to the heart cam 38, is as follows:

When the shaft 16 is rotated in the sense of arrow G in FIG. 1, the smaller reel 13 winds wire 18 onto itself. The surface of the bore 52 in the reel 13 acts on the right handed helical coil spring46 so as to tend to unwind the spring. This action increases the interaction between the strong half of the spring 46 and the bore 52, in practice looking the spring to the bore. However, the action reduces the interaction between the light half of spring 46 and cylindrical surface 53, and in practice the spring 46 slips over the surface 53. V

The larger reel 12 is caused to rotate in the same sense as the reel 13, but it does not have to rotate as fast. The action of the cylindrical surface 55 on the left handed helical coil spring 48 is such as to tend to wind up this spring 48. In practice this locks the spring 48 to the reel 12. The winding up action also reduces the interaction between the strong half of spring 48 and the internal surface of bore 54, thus permitting slip between these components as is necessary for the reel 12 to rotate. However, the frictional drag exerted by the strong half of spring 48 is greater'than the drive friction exerted by the light half of spring 46 on the reel 12. The excess frictional drag on the reel 12 provides the tension in the wire and the parameters of the

springs

46 and 48 are chosen to give the desired magnitude to this tension. For convenience of description, the action of the light halves of the stepped helical coil springs, which is in the nature of a ratchet action, is referred to as locking in one sense (the sense in which they are wound up onto the cylindrical surfaces on which they engage) and slipping (or ratchetting) in the other sense (the sense in which the drive tends to unwind the springs from engagement with the cylindrical surface). The action of the strong halves of the stepped helical coil springs is referred to as locking in one sense (in which the drive tends to unwind them into tighter engagement with their respective bores) and dragging in the other sense (in which the drive tends to wind up the springs).

For drive in the sense of arrow G in FIG. 1, the

lower reels

14, 15 are rewinding. That is, wire is wound onto reel 15 off from reel 14. The condition of the stepped helical coil springs, are as follows: the strong half of right handed helical coil spring 56 is dragging and the light half is locking: the Iighthalf of left handed helical coil spring 57 is slipping and the strong half is locking. Thus, it will be seen that the drive force to the reel 15 derived from the drag between the strong half of spring 56 and the reel 14, is greater than the resistance derived from the slipping interaction between the light half of spring 57 and the reel 15. However, the reel 15 does not have to rotate as fast as the reel 14 because the wire is wound on at ,a larger diameter. Consequently there is dragging slip between reel 14 and strong half of spring 56 because the reel 15 is held back by the wire 58. Again, the tension in the wire is provided by the excess of the drag between reel 14 and spring 56 over the slipping resistance between reel 15 and spring 57.

On reversal of the drive, the conditions of the upper and lower reeling mechanisms are exactly reversed.

The reduced drive to heart cam 38 produces a slow reciprocating tilting of the platform 22 and this action causes the wire to run onto, or off from, the reels in even axially extending layers. The setting of the

pulleys

19, 21, 24 and 25 has to be very accurate in relation to the

reels

12, 13, 14 and 15 respectively and independent adjustment of the spacing of each pulley from the plate on which it is mounted is not readily achieved because the required spacing of the wire from the plates is determined by the recording heads. However, the conditions are critical and some provision for adjustment is found to be necessary.

In this example, the adjustments provided are as follows:

I. Axial movement of the stack of

reels

12, 13, 14 and 15,

2. Adjustment of the mean tilt of the platform (c.f. arrows 43 in FIG. 3 anddescription above) 3. Lateral adjustment of the

plates

28 and 32 on the platform 22 (cf. arrows 29 in FIG. 4 and description above).

The facilities provided by these three adjustments lS best understood by reference to the effects they produce respectively on an apparatus which is initially producing perfect layering.

In FIG. 9 on the left-hand half of the FIG. the hatched regions represent perfectly layered wire with the mechanisms fully wound in one sense The right-hand half of FIG: 9 shows the corresponding perfectly wound conditions with the mechanisms fully wound in the opposite sense FIG. 10 is a condensed diagrammatic representation of this perfect layering condition. This FIG. 10 form of representation is employed in FIGS. 11 to 16.

FIG. 11 shows the effect on the layering of wire in a mechanism previously producing perfect layering if the stack of reels is moved downwardly (as seen in the FIGS.) relative to the platform 22. That is each reel is fuller at the top than at the bottom.

FIG. 12 shows the effect of the layering of wire in a mechanism previously producing perfect layering if the mean tilt of the platform 22 is moved clockwise (as seen in FIG. 3). That is, reels l2 and 14 are fuller at the top than the bottom and reels 13 and are fuller at the bottom than at the top.

FIG. 13 shows the effect on the layering of wire in a mechanism previously producing perfect layering if the plate 28 is moved to the left (as seen in FIGS. 3 and 4). That is,

reels

12 and 13 are fuller at the top than the bottom and

reels

14 and 15 remain perfect.

Many layering faults can be corrected by employing selected combinations of these three adjustments. However some faults cannot be corrected but it is usually possible to spread their effect evenly onto the four reels and thereby reduce the seriousness of the faults.

An example is shown in FIGS. 14 to 16 where reels l3, l4 and 15 are perfectly layered but the layering of reel 12 has an unacceptable fault. The seriousness of a fault may be represented numerically and 0 is used to indicate no fault, I, 2, 3, 4 to indicate faults of increasing seriousness. In this example a fault level of I on any reel can be tolerated but greater fault levels cannot be tolerated.

Thus, assuming the layering of reel 12 in FIG. 14 has a fault level of 4, movement of the plate 28 to the left (as seen in FIGS. 3 and 4) can produce the condition shown in FIG. 15 in which the fault is shared between reels l2 and 13. Each of these reels then has a layering fault level of 2.

If the platform 22 is then tilted clockwise (as seen in FIG. 3) the fault is shared between all four reels as shown in FIG. 16. Each of the four reels then has a layering fault level of l, which can be tolerated.

The mechanism of this example is particularly suitable for withstanding aircraft environment entailing, inter alia prolonged vibration at a wide range of frequencies. In this respect the doubling of the toggle effect for the reversing microswitch 66 is important. Under static conditions a microswitch does not dither but under certain conditions of vibration a switch, when in position just prior to switching, can permit the contacts to resonate and this, can cause arcing. Such arcing seriously reduces the life of the switch, creates electrical noise and can weld the contacts together or in some cases burn them causing high resistance. These serious problems are overcome or at least to some extent avoided in the arrangement of the foregoing example.

The invention is not restricted to the details of the foregoing example. For instance, although the differential land cam arrangement is preferred for effecting the doubling of the toggle action of the microswitch 66, other methods may conveniently be employed such as, for example coupling the switching force to the button 68 by a low rate secondary spring which amplifies the distance moved before switching pressure is attained. The stepped helical coil springs need not necessarily be manufactured by skimming off part of a uniform strength spring but may for example, be manufactured by initially making the strong and light halves separately and then joining them.

lclaim:

l. A mechanism for reeling an extended member off a first reel onto a second reel, the maximum diameter at which the extended member is wound onto one reel being less than the minimum diameter at which the extended member is wound off the other reel, said mechanism comprising reversible drive means directly coupled to the said first reel; a slipable clutch coupling said reversible drive means to the said second reel; brake means for acting on said second reel, the drag torque of the said brake means exceeding the drive torque of the said slipable clutch when the reversible driving means drives said first reel in a first sense for winding the extended member onto the said first reel from the said second reel; the drive torque of the slipable clutch exceeding the drag torque of the brake means when the reversible drive means drives the first reel in a sense opposite the first sense.

2. A mechanism as claimed in claim 1, further comprising shaft means, said two reels being coaxially mounted on said shaft means, means keying said first reel to said shaft and bearing means supporting said second reel for rotation about said shaft.

3. A mechanism as claimed in claim 1, wherein the slipable clutch comprises a stepped helical coil spring coupled between the reels.

4. A mechanism as claimed in claim 1, further including a supporting frame and wherein the brake means comprises a stepped helical coil spring coupled between the supporting frame and the said second reel.

5. A mechanism as claimed in claim 1 wherein the slipable clutch comprises a stepped helical coil spring having a first stepped part and a second stepped part, the diameter of the first stepped part being of larger diameter than the second stepped part in which the first stepped part of the coil spring engages a bore in the first reel and the second stepped part of the coil spring engages a cylindrical surface of said shaft means.

6. A mechanism as claimed in claim 4, wherein the brake means comprises a stepped helical coil spring of opposite hand to that comprising said slipable clutch, said stepped helical coil spring brake means having a first stepped part and a second stepped part, the stepped helical coil spring brake means first stepped part being of larger diameter than the stepped helical coil spring brake means second stepped part in which the second stepped part of the coil spring engages a cylindrical surface of the said shaft means and the first stepped helical part engages a bore in the said frame member.

7. A mechanism for reeling an extended member, as claimed in claim 1, incorporated in a magnetic wire recording mechanism.

8. A mechanism for reeling an extended member, as claimed in claim 1, wherein means are provided for automatically reversing the direction of drive to the said one reel after a predetermined amount of reeling from one reel onto the other has taken place.

9 A mechanism for reeling an extended member as claimed in claim 1, wherein guide pulleys are provided for guiding wire, tape or a like extended member off from one reel onto a coaxially mounted reel, which guide pulleys are mounted on a single platform, and wherein reciprocating means reciprocate the platform to cause the extended member to form into, or run easily from, even axially extending layers on the reels.

10. A mechanism for reeling an extended member as claimed in claim 9, wherein adjusting means adjust the setting of relative location and/or orientation of the platform and reels for applying correction to layering faults.

11. A mechanism for reeling an extended member as claimed in claim 1, wherein an automatic switching device comprises a switch member on a reel, biasing means for biasing said switch member into a switch actuating position, said extended member wound on the reel holding said switch member against the bias and whereby the releasing means releasing the switch member into a switch actuating position is the last layer of extended member.

provided comprising an operating member and an operated member both of which are arranged and biassed to be movable over the center with a toggle action between off and on conditions. and coupling means between the members arranged so that the operating member only acts upon the operated member to move the operated member over center after the operating member has moved over center.

Claims

1. A mechanism for reeling an extended member off a first reel onto a second reel, the maximum diameter at which the extended member is wound onto one reel being less than the minimum diameter at which the extended member is wound off the other reel, said mechanism comprising reversible drive means directly coupled to the said first reel; a slipable clutch coupling said reversible drive means to the said second reel; brake means for acting on said second reel, the drag torque of the said brake means exceeding the drive torque of the said slipable clutch when the reversible driving means drives said first reel in a first sense for winding the extended member onto the said first reel from the said second reel; the drive torque of the slipable clutch exceeding the drag torque of the brake means when the reversible drive means drives the first reel in a sense opposite the first sense.

9. A mechanism for reeling an extended member as claimed in claim 1, wherein guide pulleys are provided for guiding wire, tape or a like extended member off from one reel onto a coaxially mounted reel, which guide pulleys are mounted on a single platform, and wherein reciprocating means reciprocate the platform to cause the extended member to form into, or run easily from, even axially extending layers on the reels.

12. A mechanism for reeling an extended member, as claimed in claim 11, the extended member is wire, wherein the extended member is wire, said wire is wound off from one reel onto another reel and the automatic switching device reverses the drive to the reels when the said releasing means releases said switch member.

13. A mechanism for reeling an extended member as claimed in claim 1, wherein an electrical switching device is provided comprising an operating member and an operated member both of which are arranged and biassed to be movable over the center with a toggle action between off and on conditions, and coupling means between the members arranged so that the operating member only acts upon the operated member to move the operated member over center after the operating member has moved over center.