US2281188A

US2281188A - Stop motion

Info

Publication number: US2281188A
Application number: US345876A
Authority: US
Inventors: Carl B White
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-07-17
Filing date: 1940-07-17
Publication date: 1942-04-28
Anticipated expiration: 1959-04-28

Description

' A ril 28, 1942'.

3 Sheets-Sheet 1 Filed July 17, 1940 Pll-ll FigJY INVENTOR.

C. B. WHITE STOP MOTION April 28, 1942.

Filed July 17, 1940 5 Sheets-Sheet 2 c. 5. WHITE STOP MOTION April 28, 1942.

s sheets-sheet :s

Filed July 17, 1940 Patented Apr. 28, 1942 UNITED STATES PATENT OFFICE 16 Claims.

This invention relates to protective devices for spinning frames and has particular reference to new and novel means and method of providing a stop motion for a spinning frame, particularly of the cap spinning type, but it may readily be used on other types.

Such spinning frames carry numerous spindles each carrying a bobbin to which roving is carried by means of a system of rolls, some driven and some free.

It is the purpose of the device of applicants invention to provide means which, whenever there is a break in the roving for any particular bobbin, stops one of the back delivery rolls for that particular bobbin and breaks and stops the roving for that bobbin.

The principal object of this invention is to provide novel means and method of automatically preventing a break in the roving from causing damage or waste.

Another object of the invention is to provide stop motion means which may operate without a source of electrical current.

Another object of the invention is to provide, in a device having a pair of rollers held together under pressure, automatic means actuated at a point and through means removed from these rollers which under given conditions will release and/r remove the force holding the rollers together and also cause the rollers to separate.

Another object of the invention is to provide, in a spinning frame, means actuable upon the breaking of the roving for causing the pressure between the two back rollers to be released and/or removed and for separating the rollers.

Another object is to provide a device of the character described in which permanent magnets, weights and springs are used separately or in partial or complete combination to provide the automatic action as described above.

A further object of the invention is to provide, in a device having a pair of rollers held together under pressure, the method of actuating means at a point removed from these rollers which under given conditions will release and/or remove the forces holding the rollers together and also cause the rollers to separate.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings, and it will be apparent that many changes may be made in the details of construction, arrangement of parts, and steps of the method shown and described without departing from the spirit of the invention as expressed in the accompanying claims. I, therefore, do not wish to be limited to the exact details and steps shown and described, as the preferred forms only have been shown in the way of illustration.

Fig. I is a side elevation of a portion of a cap spinning frame with the device embodying my invention in position;

Fig. II is a side elevation of one form of the pressure release and roll lifting mechanism of my invention;

Fig. III is a perspective view of the detail of the mechanism for actuating the mechanism of Fig. II upon the breaking of the roving;

Fig. IV is a partial plan view of that portion of the structure of Fig. III through which the roving is passed;

Fig. V is an alternate structure and a view similar to that of Fig. II;

Fig. VI is a perspective view in detail of the release mechanism illustrated in Fig. V;

Fig. VII is a perspective view of an alternate structure performing the function of the structures of Figs. II and V;

Fig. VIII is an elevation showing the top back roll and its associated yoke;

Fig. IX illustrates an alternate structure embodying my invention;

Fig. X is an end view of a portion of the structure of Fig. IX showing release mechanism;

Fig. XI is a sectional view taken on line XI-XI of Fig. X;

Fig. XII is a side elevation of a mechanism adapted to operate in conjunction with the mechanism of Fig. IX and comprises actuating mechanism comparable to that of Fig. III; and

Fig. XIII is a side view of the construction of Fig. XII.

Many types of roving stop motion devices have been devised and utilized but serious drawbacks have been found in the use of these various structures.

One difiiculty and drawback was that sources and carriers of electrical current were necessary and in some cases these sources and carriers operated electro-magnets. These magnets were subject to deterioration and failed to operate when the electrical power for any reason was shut off or interrupted. Another disadvantage is that in prior art devices various means were used to hold the two back rollers of the spinning frame under compression together and when the roving was broken the means which operated the stop motion operated against this compression and particularly in the case of spring members it increased the compression by operating against it. In addition to operating against this compression to such an extent as to overcome it, it was necessary for the stop motion to have enough additional force to lift the top back roller away from the bottom roller.

The cost of installation of wiring in prior art devices is considerable and the electrical contacts thereof have to be replaced or repaired.

Also many prior art constructions were complicated, expensive to make and to maintain, and

necessitated attention and servicing more often than was practical.

Applicants device obviates all of the above disadvantages by providing stop motion means in which there is no source of electrical current and i in which the compression between the rollers, when the roving is broken, is released and/or removed so that the force of this compression is" not worked against, and so that the only Work a spinning frame upon which is mounted a spool 2 of roving, with the roving 3 extending'from the spool 2 between the free roll 4 and a driven roll 5, between the guide rolls 6 and I, and the free roll 8 and a driven roll 9. The roving 3 then continues through the loop It of the feeler II downwardly to the spindle and bobbin I2.

The roving 3 is drawn through the rollers and stretched during this drawing due to the fact] that the rollers 5 and 9 are driven at difierent speeds. It isa common occurrence for the roving 3 to break between the rollers B and 9 and the bobbin I2. When this happens the roving, unless stopped, continues to be driven by the rollers 5 and 9 and gets tangled up or rolls around the rollers 8 or 9, or both, and in some instances jumps to the adjacent bobbin or bobbin feed mechanism and doubles up on the roving thereof so as to spoil the winding. This action is costly and inefficient.

The roving stop motion as exemplified by applicants structure comprises feeler and actuating mechanism generally indicated at I3 and release and operating mechanism generally indicated at I4. The actuating mechanism I3 and the operating mechanism I4 are ,operatively connected by connection means I5 which, in this particular instance, comprises a flexible cable having a flexible rod therein so that a force may be exerted at one end of this rod and transferred to the other substantially without moving the cable lengthwise of itself.

It will be seen that when the spinning frame is in operation the roving 3 passing through the loop I acts to hold the feeler II in a position, as indicated in Figs. I and III, apart from that which it would normally assume if the roving 3 were not passing through the loop If]. This means that when the roving breaks the feeler II will assume its normal position, that is, the rear portion It will tend to drop due to the arrangement of the feeler II on the pivot I! being such as to cause the rear portion It of the feeler I I to be heavier than the forward portion thereof. The actuating mechanism I3 may be mounted on the frame I by screws or the like I8 and included in this mechanism is a permanent magnet I9 into the magnetic field of which the rear portion of the feeler I I is adapted to drop when the roving 3 breaks due to the fact that there is no longer the holding force on the loop IE to hold the rear portion I6 out of its normal position. As soon as the portion I of the feeler II falls within the magnetic field of the permanent magnet I9 it is immediately snapped into engagement with, or at least into holding relation with the magnet I9. It is understood that the portion It may be spaced from the magnet I9 and still be in holding relation therewith. This drawing action of the magnet I9-on the portion I6 of the feeler II acts to force the plunger of the cable I5 longitudinally through the cable and this force is transmitted to the other end of the cable which is indicated at 2| in Fig. II and the force exerted by the portion It on the rod is transferred to the portion 22 of the rod 23.

Also when the spinning frame is in operation the rolls 4 and 5 are held in compressed relation with each other, as illustrated in Fig. II, by the action of the permanent magnet 23 on the lever 24 which is mounted in the casing 25 on the pivot 25. This action of the magnet on this lever 24 exerts a force through the yoke 21 on the pin 28 which is attached to the vertically slidable plunger 29, through the plunger 29 and the yoke 30 to press downwardly on the shaft 3| of the roll 4. The roll 5 being fixed with respect to vertical force and driven about its axis is thus under compression with the roll 4 due to the lifting action of the magnet 23 on the lever 24.

The casing 25 has a stop member 32 to limit the upward movement of the plunger 29 and the plunger 29 is connected to the yoke 33 by connection means 33. The yoke 33 includes a cross bar 34 which is adapted, upon the lifting of the plunger 23, to engage the roving 3 and hold it against the bottom of the roll 4. This action is simultaneous to the moving of the lifting portion 35 of the yoke 30 upwardly against the shaft 3I.

The release and operating mechanism is mounted in the casing 25 which in turn is mounted on the frame I through a suitable bracket member 33.

It will thus be seen that when the spinning frame is operating normally the roll 4 is pressed against the roll 5 thereby squeezing the roving 3 between the rollers and this pressure is accom plished by the action of the permanent magnet 23, pulling the lever '24 upwardly about its pivot 26 and thereby pressing downwardly on the plunger 29.

However, when the roving breaks so as tov cause the actuating mechanism I3 to operate as.

described above and pushes the plunger 23 through the cable I5, the pressure on the roll 4 found to be a very practical method of substan-' tially instantly stopping the drive and pull on the roving 3 and preventing the damage as outlined above. This release of the pressure on the roll 4 and the lifting of the roll 4 is accomplished as follows. The lever 24 has thereon a weight 31 and it will readily be seen that if the influence of the magnet 23 were removed, then the lever 24 would pivot about its axis 26 under the action of the weight 31 in such a manner as to lift the plunger 29 upwardly and cause the portion 35 of the yoke 30 to engage the pivot 3| thereby lifting the roll 4 away from the roll 5.

In order to release or remove the downward pressure on the roll 4 which actually is the action of the permanent magnet 23 on the lever 24, a keeper member 38 is employed. This keeper is mounted in the casing 25 on a pivot 39 and simply comprises a soft iron member 40 which, when moved against the poles of the magnet 23, so reduces the magnetic field thereof as to release the hold of the magnet on the lever 24 thereby allowing the weight 31 to lift the plunger 29 and thereby the roll 4 by moving the lever 24 about its pivot 25. The keeper 38 may be and is when the roving breaks, moved against the poles of the magnet 23 by means of the action of the plunger 28 and specifically the end 22 of the plunger 26.

It thus is shown that when the roving breaks the feeler member 5| drops so that its rear portion I6 under the action of the magnet l9 pushes the plunger 29 through the cable I5 so as to push the keeper 38 against the magnet 23 thereby releasing the lever 24 and under the action of the weight 37 lifting the plunger 29 and the roll 4.

When the roving has been repaired and it is desired to resume normal operation, it will be seen that the keeper 38 may be moved away from the magnet 25 and the lever 24 brought into holding relation with the magnet 23 again by lifting the hand lever 4| which is pivoted at 42 to the lever 24. This lifting action brings the cam portion 43 of the lever 4| into action against the pin 44 which is attached to the keeper 38 in such a manner as to cause the pin to ride on the cam and force the keeper 38 away from the magnet 23. This lifting action on the hand lever 4| is carried out through the backing action of the end 45 of the lever 4| against the portion 46 of the lever 24. Having removed the keeper 38 from the magnet 23 and reestablished holding relation between the lever 24 and the magnet 23, the hand lever 4| may then be moved downwardly about its pivot 42 so as to move the cam surface 43 out of the way and permit the keeper 38 to again be moved against the magnet 23 when the roving 3 is again broken.

The permanent magnets l9 and 23 are preferably made of the material commercially known as Alnico and the portion l3 of the feeler H is preferably of cold rolled steel. It is to be understood that other suitable materials performing a similar function may be used if desired. The plunger 2:9 is mounted in the casing 25 for vertical movement through a suitable bushing 41.

As illustrated in Fig IV, the loop I is so formed as to permit the roving 3 to be snapped into place between the convolutions of the loop.

The pressure of the roll 4 on the roll may be varied by movement of the magnet 23 upwardly or downwardly by means of the threaded bolt 48 and the nut 49, with the bolt being fixed in the magnet 23 by suitable means such as a head 50. This movement is guided by a guide member 5| attached to the casing 25 by suitable means such as screws 52. It will be seen that the magnet 23 need not be in actual contact with the lever 24 in order to hold it so as to cause the roll 4 to press on the roll 5, although it may be if desired. By moving the magnet 23 upwardly it will be seen that the pressure on the roll 4 will be diminished and vice versa.

The cable |5 is mounted in the casing 25 through suitable connection means such as a journal or nut 53.

In Fig. V an alternate construction is illustrated which is similar in function to that of Fig. II. The general function is the same, that is, the lever 54 moving about its pivot will cause the plunger 29 to move upwardly or downwardly and thereby exert or release pressure on the roll 4. It is pointed out that in this instance, as well as that illustrated in Fig. II, the downward pressure on the roll 4 against the roll 5 is completely released or removed first and then the roll is lifted so that there is none of the prior art difficulty of working against the downward pressure.

In the construction of Fig. V there is a magnet 56 supported on the lever 54 and comprises a central portion 51 and pole pieces 58. This magnet has weight and tends to move the lever 54 about its pivot 55 so as to lift the plunger 29. It will be seen that in the construction of Fig. V the plunger 29 is shown in the up position with the rolls 4 and 5 separated. During the normal operation of the spinning machine when the roving is unbroken, the roll 4 is pressed against the roll 5 due to the holding up of the lever 54 by means of the following. There is a lever 59 also pivoted on the pivot 55 of the lever 54 and, extending vertically past the lever 59 and supported in the casing 25, is an upright bolt 50 which has a head 6| within the casing and extends upwardly through the top of the casing and has threaded on its upper end a nut 62. Between the head portion 6| of this bolt and the lever 59 is mounted a coil spring 63. This spring acts downwardly against the head El and upwardly against the lever 59. The upward motion of the lever 59 about its pivot 55 is limited by the stop pin 64 mounted in the casing 25 so that when the lever 59 is free to move about its pivot 55 the spring 63 will force it upwardly against the stop 64 without any action whatsoever on the plunger 29. However, when the lever 59 is brought downwardly within the magnetic field of the magnet 56 by pressure on the hand lever 4|, the spring 63 then effectively acts upwardly against the lever 54 since the

levels

54 and 59 are joined by the magnetic force of the magnet. This is the normal operating position of this structure, that is, when the roving is unbroken and the machine is in operation. The spring 53 forces the lever 54 upwardly about its pivot 55 thereby exerting a downward force on the plunger 29. This force may be varied by movement of the nut 62. As this nut is tightened on the bolt 60 the spring 63 is compressed and the force it exerts is accordingly greater.

As in the structure of Fig. II, the release mechanism comprises a keeper member 38 having the usual soft iron member 40 operated by the end 22 of the plunger 26. This keeper is supported in the casing 25 about the pivot 39 and upon the movement of the keeper 38 against the pole pieces 58 of the magnet 56 the magnetic field of this magnet is so reduced as to release the lever 59 from its holding relation with the magnet 56 and the lever 54, thus permitting the spring 63 to move the lever 59 upwardly about the pivot 55 with the action on the plunger 29 thus releasing the downward pressure thereon and also permitting the magnet 56 to utilize its function as a weight and causes the lever 54 to move about its pivot 55 thereby lifting the plunger 25 and separating rolls 4 and 5 in a manner similar to that described in connection with the structure of Fig. II.

When it is desired to remove the keeper from contact with the magnet 56 so as to permit the resetting of the machine and resuming of normal operation the lever 4| is moved downwardly about the pivot 55 and the arm 65 contacts the keeper 38 and pushes it away from the magnet 56 and at the same time the lever 59 again comes within the magnetic field of the magnet 56. After this has been done the lever 4! is moved about its pivot 42 in an upward direction to move the arm 65 away from the magnet 56 and again permit the approach of the keeper 38 when the roving is again broken. Suitable indexing means is provided for the up and down positions of the arm 4| as indicated at 66.

If desired, the magnet of this structure, as,

shown in Fig. V, may be dispensed with and the lever 59 held in operative relation with the lever 54 by means of a latch arrangement, so that the two levers may be held together and the spring 63 act against the lever 54 to cause the compression between the rollers.

As illustrated in Fig. VI, the lever 59 has an opening 6! therein to permit the passage of the bolt 69 and the lever 54 also has an opening 68 therein to permit the passage of the bolt 60 and to permit the insertion of the end of the lever 59 so that it may be mounted on the pivot 55. It is to be understood, however, that the bolt 65 and the mounting of the lever 55 on the pivot 55 may be at either side of the levers rather than in the center as shown.

It is to be understood that the latch arrangement also may be used in connection with the structure of Fig. II if desired, or other similar structures.

Fig. VII illustrates another alternate construction of the release and lifting mechanism. As before it will be seen that the roll 4 contacts the roll 5 with the roving 3 running therebetween. The rolls 4 and 5 are held together in this instance by the direct magnetic action brought about through the action of the permanent magnet 69. When the spinning frame is in normal running condition and the rolls are pressed together the base permanent magnet 69 is positioned as illustrated in Fig. VII. It has for pole pieces the member 15 and the member ll. As before, this central portion of the magnet is preferably of Alnico and the pole pieces of soft iron for better conductivity of the magnetic field. The magnet 69 is in contact with one side of the top of the T-shaped pole piece H and rests upon the pivot 12 of the pole piece 70. The pole piece has an arcuate face 13 lying adjacent the side of the roll 4 and the pole piece H has an arcuate face 14 in contact with the roll 5. The magnetic field of the magnet 69 in this position therefore travels from the magnet 59 through the pole piece 10, through the roll 4, through the roll 5, upwardly through the pole piece H and back into the magnet 69. This magnetic field exerts a force between the rolls 4' and 5 which is sufficient to provide the necessary compression on the roving 3.

When the roving is broken the plunger through the cable I5 is actuated as previously described and causes the magnet 69 to be released from a catch mechanism 15. The magnet 65 is thereupon moved about the pivot 12 by the action of the spring 15 which is mounted with one enrich the support 11, which in turn is mounted 'on the frame I, and the other end mounted on the magnet as at 18. This spring action draws the magnet out of contactwith the upperportion of the T-shaped pole piece H and into contact with the pole piece 19. The pole piece '19 is supported on the pole piece 18 by an'insulated bracket 88 so that there is no magnetic field travel through the bracket 80. The pole piece 19 is so supported as to be in spaced relation with the roll 4 when the spinning frame is in normal operation, that is, when the roll 4 is under compression against the roll 5. However, upon the movement of the magnet 69 into contact with the pole piece 19 it will be seen that the path of the magnetic field of the magnet 69 immediately changes. It no longer goes through both roll 4 and the roll 5 but travels from the magnet 69 downwardl through the pole piece 10, the face 13 of which is in slightly spaced relation with the roll 4, through the roll 4 and upwardly through the pole piece 19 back into the magnet 69. This change of travel of the magnetic field immediately causes the release of the pressure between the rolls 4 and 5 and also lifts the roll 4 up against the arcuate face 8| of the pole piece l9. If desired a suitable clamping arrangement similar to that illustrated at 34 in Fig. V may be utilized in the alternate construction of Fig. VII so as to provide means for simultaneously lifting the roll 4 and holding the roving 3 thereagainst. This could be accomplished by means actuated by the lifting of the roll if desired. A

The pole piece H is formed in the T-shape illustrated in Fig. VII so as to make possible the double use of the pole piece II, that is, it would act as a pole piece of the mechanism shown and also for the next adjacent group of rollers.

It will thus be seen that when the roving is broken the construction of Fig. VII acts so as to remove or release the pressure between the rollers prior to the lifting action exerted on the roll 4.

Still another alternate construction is shown in Fig, IX. In this construction the compression between the rolls 4 and 5 is accomplished by means of a weight 82 acting on a lever 83 about a pivot 84 mounted on an upright 85 which in turn is mounted on the frame I. The lever 83 has a yoke portion 86 operating in conjunction with a pin 87 mounted on a plunger 29 so that the weight 32 forces the rolls 4 and 5 together. When the roving is broken the shaft through the cable i5 operates to release the weight 82 and permit it to slide downwardly along the lever 83 and up against the stop 88. Since the weight 82 passes the pivot 84 on its downward slide the compression between the rolls 4 and 5 is removed and thereafter the weight 82 acts on the lever 83 so as to liftthe plunger 29 and separate the rolls 4 and 5. The

cable attached thereto, and snapping it intoholding relation with its catch.

In Fig. X is illustrated the release mechanism operated by the plunger through the cable I5 to permit the Weight 82 to slide down the lever 83 and comprises a lever 89 pivoted at 90 and having thereon a pin member 9| resting in a catch 92 which is attached to the lever 83. It will be seen that when the plunger is operated through the cable I5 the lever 89 is lifted removing the pin 9| from the catch 92 and permitting the weight to slide down the lever 83.

A cable 93 is attached to the weight 82 by a suitable hook 94 and passed through an opening in a bar member 95 mounted on the lever 83 so that the resetting mechanism may be operated by a pull on the cable 93 as by suitable lever means as described above.

Fig. XI is a sectional view illustrating the connection of the cable 93 and the pin BI and the catch 92, with the catch 92 mounted on the lever 83 by suitable screw means 96 or the like. I

In Fig. XII is illustrated a mechanism of a function similar to that of the structure of Fig. III. It has a feeler member 91 and a loop 98 through which the roving 3 passes. This feeler is mounted on a pivot 99 which in turn is mounted on an upright I09 which again in turn may be mounted on the frame I. Also mounted on the shaft 99 is a disk IOI and the feeler 91 has a rear portion I92. On this disk is a weight I03,

When the spinning frame is in normal operation and the roving is passing through the loop 98 the feeler 91 is in substantially the position shown in Fig. XII.

On the disk IIlI are stop members I94, I95 and I06. The feeler member 9'! may pivot free about its axis 99 within the limits of the stops I94 and I95, since the stops I94 and I 95 are adapted to engage the ieeler 97 as it is pivoted about its axis 99. The stop I96 is adapted to engage the upright I I19 and it is so positioned on the disk IIJI with respect to the position of the weight I03 that the weight I93 will be slightly off center with respect to the pivot 99 on the side of the stop I 06 so that when the machine is in operation the weight I93 tends to move the disk IIII about the pivot 99 but is kept from so moving by the contact of the stop I96 with the upright I00.

When the roving breaks the end I92 of the feeler 91 is so weighted as to cause the feeler to move about the pivot 99 in such a way that the end I02 will drop, the feeler 91 will come into contact with the stops I94 and I95 which are on the disk I9I thereby causing the disk to move in counter-clockwise direction. ment of the disk IOI about the pivot 99 will bring the weight I03 to such a position that the weight will further urge the disk IIII about the pivot 99 and with a force greater than that possible by the movement of the feeler 91. This movement brings the stop I04 into contact with the plunger III! which moves through the cable I08 to operate the release mechanism on the weight 82 as described above.

Thus it is seen that again the breaking of the roving permits the movement of the feeler and causes the actuation of the shaft through the cable thence releasing the pressure on the rolls and lifting the top back roll away from the bottom back roll.

Variable pressure may be achieved in the construction as illustrated in Fig. IX merely by moving the weight closer to or further away from the pivot 84 along the lever 83.

Also, if desired, the construction of Fig. IX

A short movemay be used with the construction of Fig. III or any other variation or grouping of the various alternate structures described may be used.

The arcuate faces of the pole pieces of Fig. VII are preferably of substantially the same curvature as the respective adjacent roll or contact portion.

From the foregoing description it will be seen that new and novel means and methods have been provided for accomplishing the objects of applicants invention.

Having described my invention, I claim:

1. In a device for stopping the movement of the roving in a spinning machine, actuating means operable by the breaking of the roving, means exerting applied pressure on said roving through a first pressure member against a second pressure member, with said first member positioned above and with at least a part of its weight also exerting a pressure on, said second member and means operated by said actuating means for relieving both of said members of said applied pressure and separating said members.

2. In a device for stopping the movement of the roving in a spinning machine, actuating means operable by the breaking of the roving, means exerting pressure on said roving through a first pressure member against a second pressure member, and means operated by said actuating means for relieving both of said members of said pressure and separating said members, said actuating means and said means operated by said actuating means being automatically electrically operable from unit permanently magnetic sources of power independent of outside power supply. I

3. In a device of the character described, a first member under pressure against a second member, operating means associated with one of said members and including a permanent magnet, actuating means also including a permanent magnet and adapted to function under predetermined conditions, and means adapted to be activated by a functioning of said actuating means so as to operate said operating means to cause both of said members to be relieved of said pressure and said members to be separated.

4. In a device for stopping the movement of the roving in a spinning machine, actuating means, including a permanent magnet, operable by the breaking of the roving, means exerting pressure on said roving through a first pressure member against a second pressure member and means, including a permanent magnet, operated by said actuating means for relieving both of said members of said pressure and separating said members.

5. In a device of the character described, a first member under spring pressure against a second member, operating means including a permanent magnet associated with one of said members, actuating means adapted to function under predetermined conditions and means adapted to be activated by the functioning of said actuating means so as to operate said operating means by changing the path of the field of said permanent magnet to cause both of said members to be relieved of said pressure and said members to be separated.

6. In a device for stopping the movement of the roving in a spinning machine, actuating means, including a permanent magnet, operable by the breaking of the roving, means exerting spring pressure on said roving through a first pressure member against a second pressure memher and means operated by said actuating means for relieving both of said members of said spring pressure by changing the path of the field of the permanent magnet and thereafter separating said members.

7. In a device for stopping the movement of the roving in a spinning machine, actuating means operable by the breaking of the roving,

permanent magnetic means exerting pressure on said roving through a first pressure member against a second pressure member, means operated by said actuating means for relieving both of said members of said pressure and per- -manent magnet means adapted to thereafter separate said members.

8. In a device for stopping the movement of the roving in a spinning machine, actuating means operable by a weight upon the breaking of the roving, means exerting pressure on said roving through a first pressure member against a second pressure member and permanently magnetic means adapted to be brought into action by said actuating means for relieving both of said members of said pressure and for separating said members.

9. In a device for stopping the movement of the roving in a spinning machine, permanently magnetic actuating means operable by the breaking of the roving, weight means exerting pressure on said roving through a first pressure member against a second pressure member and means operated by said actuating means for relieving both of said members of the pressure of said weight and thereafter utilizing said weight for separating said members.

10. In a device of the character described, a supply of roving, a pair of rolls, with one above and resting on the other, between which the roving is passed and a bobbin on which the roving is wound, means associated with said rolls for exerting pressure therebetween, means riding on said roving and adapted to change position when the roving is broken, and means operated by said position change adapted to remove said pressure and separate said rolls.

11. In a device of the character described, a first member under pressure against a second member, operating means associated with one of said members, actuating means adapted to function under predetermined conditions, and means adapted to be activated by the functioning of said actuating means so as to operate said operating means to cause both of said members to be relieved of said pressure and said members to be separated, said operating means including a weight member tending to separate said members and permanently magnetic holding means adapted to hold said members together against the separating tendency of said weight.

12. The method of operating a roving stop motion on a spinning frame comprising holding a pair of rollers together under pressure by passing the path of the field of a permanent magnet through both of said rollers, and upon the break.- ing of the roving, relieving the holding force on the rollers by changing the path of the field of said magnet so as to pass it through one roller only.

13. The method of operating a spinning frame comprising passing roving between two rollers, with one above the other and pressing on it under the action of at least a part of its weight, pressing said rollers together, and, through means actuated by the breaking of the roving, relieving both of said rollers of said applied pressure and lifting the one away from the other. 14. In a device of the character described, a supply of roving, a pair of rolls between which said roving is passed, with one of said rolls resting with at least a part of its own weight pressing downward on the other of said rolls, a bobbin on which the roving is wound, pressure means associated with said rolls for exerting additional pressure therebetween, feeler means riding on said roving and adapted to change position when the roving is broken, and operating means actuated by said position change, adapted to remove said additional pressure and to so separate said rolls as to relieve said other of said rolls of the weight of said one of said rolls.

15. In a device of the character described, a supply of roving, a pair of rolls between which said roving is passed, with one of said rolls resting with at least a part of its own weight pressing downward on the other of said rolls, a bobbin on which the roving is wound, pressure means associated with said rolls for exerting additional pressure therebetween, feeler means riding on said roving and adapted to change position when the roving is broken, operating means actuated by said position change, adapted to remove said additional pressure and to so separate said rolls as to relieve said other of said rolls of the weight of said one of said rolls, and resetting means operable to again apply both of said pressures to said other of said rolls.

16. The method of operating a spinning frame comprising passing roving between two rollers, resting one of said rollers against, and with at least a part of its own weight pressing downward on, the other of said rollers, pressing said rollers together with additionalpressure, relieving both of said rollers of said additional pressure, and relieving said other of said rollers of the weight of said one of said rollers.

CARL B. WHITE.