US3599415A

US3599415A - Spindle stopping method and apparatus for implementing same

Info

Publication number: US3599415A
Application number: US832890A
Authority: US
Inventors: Rudolf Jaeggli
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 1968-06-14
Filing date: 1969-06-13
Publication date: 1971-08-17
Anticipated expiration: 1988-08-17
Also published as: FR2010903A1; CH469827A; DE1930100A1; GB1235436A

Abstract

A method of stopping spindles of drawtwisting or heavy ring twisting machines having a moving drive tape in contact with a rotating spindle whorl, comprising the steps of relieving the contact pressure between the tape and the spindle whorl by injecting compressed air into the converging space defined by the tape and the spindle whorl and braking each spindle by pressing a braking element against such spindle. There is also disclosed an apparatus for stopping a spindle of a multiple spindle tape drive having a moving tape in contact with a spindle whorl, which apparatus comprises tape lifting means for relieving the contact of the tape on the whorl, the tape lifting means comprising a nozzle injecting compressed air between the tape and the whorl in the direction of movement of the tape.

Description

United States Patent Inventor Rudoll heal Bern, Switzerland App]. No. 832,890 Filed June 131 1969 Patented Aug. 17, I971 Assignee Relter Machine Works Ltd.

- Winter-that, Switzerland Priority June 14, 1968 Switzerland SPINDLE STOPPING METHOD AND APPARATUS [56} References Cited] UNIT ED STATES PATENTS 3,224,180 12/1965 Graf 57/88 3,256,684 6/1966 Stahlecker et al. 57/88.

Primary Examiner.lohn Petrakes Anomy-Weiner W Kleeman ABSTRACT: A method of stopping spindles of drawtwisting or heavy ring twisting machines having a moving drive tape in contact with a rotating spindle whorl, comprising the steps of relieving the contact pressure between the tape and the spindle whorl by injecting compressed air into the converging space defined by the tape and the spindle whorl and braking each spindle by pressing a braking element against such spindle. There is also disclosed an apparatus for stopping a spindle of a multiple spindle tape drive having a moving tape in con tact with a spindle whorl, which apparatus comprises tape |ifting means for relieving the contact of the tape on the whorl. the tape lifting means comprising a nozzle injecting compressed air between the tape and the whorl in the direction of movement ofthe tape.

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SPINDLE STOPPING METHOD AND APPARATUS FOR IMPLEMENTING SAME The present invention .concems a new and improved method of stopping spindles of drawtwisting and heavy twisting machines provided with a drive arrangement driving a plurality of spindles, and an improved apparatus for implementing the method.

In known spindle drive arrangements of conventional design a plurality of spindles as a rule are driven by a tape surrounding four spindles .driven by a drive shaft. Stopping of the spindle iseffected by means of braking the spindle while the tape keeps running, so that friction heat is generated between spindle and tape, which can be dissipated to a limited extent only, as said heat depending upon the tape tension can correspond to twice and up to five times the value of the drive energy of the spindle. The increase of the friction heat generated by braking a spindle brought about by the increased package weight and spindle speeds causes excessive tape wear so that the tapes must be replaced periodically within very short periods of life. Under extreme conditions a tape might not withstand even one single braking cycle. For this reason the elimination of multiple spindle tape drives and provision of individual spindle tape drives equipped with tape lifting brakes were tired. Such individual spindle tape drives are expensive compared to multiple spindle tape drives. It also has been proposed to provided the spindles with a disengageably arranged whorl. This arrangement, however, has the disadvantage of considerable wear existing at the required whorl bearing. On the other hand, tape lifting brakes already have been proposed which interrupt the contact between the tape and the spindle whorl, apart from the aforementioned individual spindle drives. Such tape lifting brakes, however, must be equipped with tension rolls taking up the tape path length difference between the drive position and the lifted position, if unduly high tensions are to be avoided. Furthermore, such tape lifting brakes also are relatively expensive if the lifting devices are rolls or the like. If the cheaper lifting cams are chosen, friction against the tape again is generated, causing tape wear and heat generation also. It is the goal of the present invention to eliminate these disadvantages and to provide a method as well as an apparatus ensuring a long drive tape life, limiting design complication to a minimum, and suppressing any influence on the speed of spindles not subject to the braking action. Also, friction heat still generated between the whorl and drive tape is dissipated directly to the surrounding air instead of being transferred to the spindle or to the drive tape. The method according to the invention of stopping spindles of drawtwisting or heavy ring twisting machines by means of relieving the contact pressure of the drive tape against the spindle whorl is characterized in that an air cushion is formed between the drive tape and the spindle whorl by means of injection of compressed air into the converging space formed by the spindle whorl and the drive tape and braking by pressing a braking element against the spindle.

The apparatus for stopping a spindle of a multiple spindle tape drive using means of relieving the contact of the tape against the spindle whorl is characterized in that the tape lifting element is formed by a nozzle injecting compressed air in the direction of tape movement between the tape and the whorl.

The invention itself will be better understood from the following detailed description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a top plan view of the spindle drive elements of a portion of a heavy ring twisting or drawtwisting machine constructed in accordance with this invention;

FIG. 2 is a side elevational view, partly in section, taken along lines II-II of FIG. 1;

FIGS. 3 and 4 are axonometric views of two fonns of nozzles utilized in the machine of FIG. 1;

FIG. 5 is a front elevational view of a flat nozzle;

FIG. 6 is a side sectional view of the nozzle of Figure 5, taken along lines VI-VI;

FIG. 7 is an axonometric view showing a nozzle including a whorl;

FIG. 8 is a schematic plan view of a portion of the system supplying the nozzles with compressed air:

FIG. 9 is a schematic elevational view of a spindle with a nozzle and brake; and,

FIGS. 10 and 11 are horizontal sectional views respectively showing two forms of spindle brakes.

Referring first to FIGS. 1 and 2, a plurality of spindles 1 are mounted in the spindle rails 2. By means of a nozzle 3 compressed air is injected into a converging space 4 between spindle whorls 5 (Fig. 2) and an oncoming drive tape 6, an air cushion building up between whorl 5 and tape 6, which reduces the contact pressure of the tape 6 on the whorl 5, and thus the torque transmitted, to such an extent, that spindle 1 can be braked without application of a large braking force, by means of a spindle brake 7 of a type known as such, a valve 8' being activated during the braking action being provided for each nozzle. The compressed air is supplied by a network 8. A round nozzle 9 (FIG. 3) is suitable e.g. particularly for narrow drive tapes, a flat nozzle 10 (FIGS. 5 and 6) or a nozzle 11 (FIG. 4) provided with a plurality of round exit holes 12 for wide drive tapes. A nozzle 11' for very convex whorls W is shown in Fig. 7. Here one injector hole each is pointed an upwardly and downwardly towards the plane E of the largest whorl circumference circle K. Thus a somewhat higher pressure builds up in this plane as the air streams injected must be more deflected. Furthermore, a dual nozzle arrangement 13 (Fig. 8) is possible, allowing for a change of the direction of the spindle rotation for producing an S or Z twist in the yarn, if a shiftable nozzle arrangement is not preferred. Also two independent nozzle systems can be used. A switching valve 15 inserted into the network 14 is activated by a central control unit 16 while the direction of spindle rotation is being reversed. Control of the compressed air supply to the nozzles arranged at the spindles can be combined also with the braking device of the spindles, e.g. in a mechanical spindle brake arrangement 17 a valve 19 of the nozzle 20 can be activated by means of a brake foot pedal 18. If the brake 17 is released, valve 19 is closed again and the supply of compressed air is stopped (Fig. 9).

Activation of the brake shoe 21 by means of an electromagnet 22 combined with an electrovalve 23 for the supply of compressed air for nozzle 24 activated by the same relays 21' is shown in Fig. II. Furthermore, pneumatic activation of brake shoes 25 by means of pressure ducts 26 can be combined with a nozzle 29 connected to the same duct 27 via valve 28 (Fig. 10).

Example: A four spindle tape drive arrangement, the spindles of which are provided with a whorl of 62 mm. diameter, is driven by a drive tape of 25 mm. width. The nozzle injecting compressed air is provided with an injecting opening of 16 mm. width and 1 mm. height. It thus is a nozzle of the type shown in FIGS. 5 and 6. Using this arrangement at various spindle speeds the following results were achieved:

As shown by experience a brake power of 360 W, correspond ing to stopping from 8,000 r.p.m. without using compressed air injection is feasible. At 15,000 r.p.m. and at this maximum feasible brake power of about 360 W trouble free braking is possible if compressed air of about 0.7 atmospheres above atmospheric pressure is injected.

Of course, another multiple spindle drive arrangement such as"e.g. a tangential belt drive in which the belt is guided along the row of spindles can be used instead of the four spindle tape drive mentioned above. While there is shown and described present preferred emb'odiments of the invention, it is to be distinctly understood plurality of spindles, comprising the steps of relieving the contact pressure between said tape and any given one of said spindle whorls by injecting compressed air into the converging space defined by said tape and said given spindle whorl desired to be braked, and braking said associated spindle by pressing a braking element against said spindle, said drive tape remaining in contact with the remaining spindle whorls for driving the remaining associated spindles thereof even though said given spindle whorl has been braked, so that anyone of said plurality of rotating spindle whorls can be braked independently of and without stopping the drive tape from continuing to drive the remaining spindle whorls.

, 2. A method as defined in claim 1, wherein said compressed air is injected into said converging space in the direction of movement of said tape.

3. A method as defined in claim 1, wherein said braking and said injection of compressed air occur simultaneously.

4. A method of stopping spindles of drawtwisting or heavy ring twisting machines having a moving drive tape in contact with a rotating spindle whorl, comprising relieving the contact pressure between said tape and said spindle whorl by injecting compressed air into the converging space defined by said tape and said spindle whorl and braking said spindle by pressing a braking element against said spindle, a single source of compressed air being used both for said injection of compressed air and for pressing said braking element against said spindle.

5. An apparatus for stopping a spindle of a multiple spindle tape drive having a moving tape in contact with each spindle whorl of a plurality of spindles, comprising tape lifting means for relieving the contact of said tape with each said whorl of said plurality of spindles, said tape lifting means comprising for each spindle at least one nozzle for selectively injecting compressed air between said tape and any given one of said whorls in the direction of movement of said tape, to thereby relieve the contact of said tape with said given whorl while the tape still remains in contact with the remaining whorls for driving the remaining associated spindles thereof even though said given whorl has been placed out of contact with the moving tape.

6. An apparatus for stopping a spindle of a multiple spindle tape drive having a moving tape in contact with a spindle whorl, comprising tape lifting means for relieving the contact of said tape in said whorl, said tape lifting means comprising a nozzle injecting compressed air between said tape and said whorl in the direction of movement of said tape, a supply of compressed air for said nozzle, and braking means for each said spindle, said supply of compressed air and said braking means being connected to a single control means.

7. An apparatus as defined in claim 6, wherein said supply of compressed air and said braking means for said spindle are activated by electromagnets.

8. An apparatus as defined in claim 6, wherein said braking means for said spindle is pneumatically activated, said source of compressed air and said braking means beingconnected to a common pressure source by means of a common valve.

9. An apparatus as defined in claim 5, wherein each said spindle has two of said nozzles, said nozzles operating alternativeij' depending upon the direction of rotation of said spindle. l An apparatus for stopping a spindle of a multiple spindle tape drive having a moving tape in contact with a spindle whorl, comprising tape lifting means for relieving the contact of said tape on said whorl, said tape lifting means comprising a nozzle injecting compressed air between said tape and said whorl in the direction of movement of said tape, each said spindle having two of said nozzles, said nozzles operating alternatively depending upon the direction or rotation of said spindle, said alternative actuation of said nozzles being effected by means of a switching valve activated by a control means.

11. An apparatus for stopping a spindle of a multiple spindle tape drive having a moving tape in contact with a spindle whorl, comprising tape lifting means for relieving the contact of said tape on said whorl, said tape lifting means comprising a nozzle injecting compressed air between said tape and said whorl in the direction of movement of said tape, each said spindle having two of said nozzles, said nozzles operating alternatively depending upon the direction of rotation of said spindle, braking means for each said spindle, said nozzle and said braking means for said spindle being jointly actuated by a common actuating means.

12. An apparatus as defined in claim 5, wherein said nozzle comprises a flat nozzle.

13. An apparatus as defined in claim 12, wherein said flat nozzle comprises a plurality of injector openings for said compressed air.

14. An apparatus as defined in claim 13, wherein said injector openings are mutually inclined so that a converging stream of compressed air is formed meeting said whorl at its largest diameter.

Claims

1. A method of stopping individual spindles of drawtwisting or heavy ring twisting machines having a single-moving drive tape in contact with a plurality of rotating spindle whorls of a plurality of spindles, comprising the steps of relieving the contact pressure between said tape and any given one of said spindle whorls by injecting compressed air into the converging space defined by said tape and said given spindle whorl desired to be braked, and braking said associated spindle by pressing a braking element against said spindle, said drive tape remaining in contact with the remaining spindle whorls for driving the remaining associated spindles thereof even though said given spindle whorl has been braked, so that anyone of said plurality of rotating spindle whorls can be braked independently of and without stopping the drive tape from continuing to drive the remaining spindle whorls.

2. A method as defined in claim 1, wherein said compressed air is injected into said converging space in the direction of movement of said tape.

8. An apparatus as defined in claim 6, wherein said braking means for said spindle is pneumatically activated, said source of compressed air and said braking means being connected to a common pressure source by means of a common valve.

9. An apparatus as defined in claim 5, wherein each said spindle has two of said nozzles, said nozzles operating alternatively depending upon the direction of rotation of said spindle.

10. An apparatus for stopping a spindle of a multiple spindle tape drive having a moving tape in contact with a spindle whorl, comprising tape lifting means for relieving the contact of said tape on said whorl, said tape lifting means comprising a nozzle injecting compressed air between said tape and said whorl in the direction of movement of said tape, each said spindle having two of said nozzles, said nozzles operating alternatively depending upon the direction or rotation of said spindle, said alternative actuation of said nozzles being effected by means of a switching valve activated by a control means.