CA1084024A - Apparatus for laying-up together a plurality of fragile filaments - Google Patents
Apparatus for laying-up together a plurality of fragile filamentsInfo
- Publication number
- CA1084024A CA1084024A CA335,499A CA335499A CA1084024A CA 1084024 A CA1084024 A CA 1084024A CA 335499 A CA335499 A CA 335499A CA 1084024 A CA1084024 A CA 1084024A
- Authority
- CA
- Canada
- Prior art keywords
- bobbin
- lever
- braking
- disc
- winding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Tension Adjustment In Filamentary Materials (AREA)
Abstract
ABSTRACT
The present invention relates to braking means for bobbins which are mounted for rotation about a bobbin axis and have a winding of a filament thereon. The braking means comprises a disc co-axial with the bobbin and coupled thereto for rotation therewith, a braking lever mounted for pivotal movement around a first lever axis parallel to the bobbin axis and having an end engaging the disc at different radial positions thereon with pivotal movement of the lever, adjustable means urging the end of the lever against the disc, a control lever mounted for pivotal movement toward and away from the winding and having an end thereof urged toward and engag-ing said winding, and means interconnecting the control lever and the braking lever for causing the end of the braking lever to move nearer the bobbin axis as the winding decreases in radius.
The present invention relates to braking means for bobbins which are mounted for rotation about a bobbin axis and have a winding of a filament thereon. The braking means comprises a disc co-axial with the bobbin and coupled thereto for rotation therewith, a braking lever mounted for pivotal movement around a first lever axis parallel to the bobbin axis and having an end engaging the disc at different radial positions thereon with pivotal movement of the lever, adjustable means urging the end of the lever against the disc, a control lever mounted for pivotal movement toward and away from the winding and having an end thereof urged toward and engag-ing said winding, and means interconnecting the control lever and the braking lever for causing the end of the braking lever to move nearer the bobbin axis as the winding decreases in radius.
Description
i~84~24 This application is a divisional of parent applicatîon Serial Number 2~6,037.
The present invention relates to braking devices suitable for use in unwinding thin elongated material from bobbins. The present invention has been found to be particularly suitable for use with apparatus of the type described in parent application number 286,037, i.e. apparatus for laying up, or helically winding together a plurality of fine filaments.
Herein the term "fine filaments" means filaments having a very low capacity for resisting the mechanical stresses to which they are conven-tionally subjected during the laying together procedure, such as for example, torsion, traction and flexing, which is due either to the dimensions of the said filaments, for example, their very small diameters, or else due to the very nature of the material out of which they are composed, e.g. glass yarn fiber.
Apparatus are well known for laying up a plurality of wires. Under normal operating conditions, such apparatus generally subject the wires to torsional, tractive and bending stresses from the moment the wires unwind from the bobbins which carry them, until they are layed-up together.
The braking devices used in the known apparatus, give rise to ten-sion stresses on the wires that are variable in a wide range of values. If, therefore, these braking devices are used for laying together fine filaments, as defined above, deformations can take place which may lead to some break-ages in said filaments.
It is the general object of the present in~ention to provide an improYed braking device suitable for use in unwinding thin elongated material from bobbins.
It is a further object of the present invention to provide an im-proved ~raking device suitable for use ~ith apparatus of the type described ~0840Z4 in parent application Serial Number 286,037, i.e. apparatus for laying up, or helically winding together a plurality of fine filaments.
According to the present invention there is provided braking means for bobbins which are mounted for rotation about a bobbin axis and have a winding of a filament thereon. The braking means comprises a disc co-axial with the bobbin axis and adapted to be coupled to a bobbin for rotation there-with, a braking lever mounted for pivotal movement around a first lever axis parallel to the bobbin axis and having an end engaging the disc at different radial positions thereon with pivotal movement of the lever, adjustable means urging the end of the lever against the disc, a control lever mounted for pivotal movement toward and away from the winding and having an end thereof urged toward and engaging the winding, and means interconnecting the control lever and the braking lever for causing the end of the braking lever to move nearer the bobbin axis as the winding decreases in radius.
The present invention will be better ~mderstood from the following erc/'~
1~ detailed description of a preferred embodiment thereof~ when D Figures lard2 are, respectively, side elevation and plan views of a bobbin braking apparatus;
Figure 3 is an enlarged, fragmentary cross-sectional view of the bobbin supporting apparatus shown in Figures land2 and is taken along the axis A-B indicated in Figure 2.
Referring to Figures 1 and 2 there is shown a support 9 on which a bobbin 10 is mounted. Said support 9 comprises a body 30 from which two parallel arms 31 extend, the arms being spaced apart from each other and having a length such as to contain the above said bobbin 10.
Referring to Figure 3, in each of said arms 31, there is formed a through-hole with its axis A-B perpendicular to the longitudinal axis of the support 9 itself. In said through-holes, there are disposed bushings 32 and 108~02~
33 respectively, in which are situated bearings 34 and 35 spaced apart from each other by means of the spacers 36 and 37 and maintained in position by means of circlips 38 and 39. The shafts 40 and 41 are mounted respectively, on bearings 34 and 35, and each has, on its extremity facing the longitudinal axis of the support 9, the cylindrical covers 42 and 43 that are received in the ends of the hollow core 44 of the bobbin 10.
In particular, the cover 43 is provided with teeth 45 which engage with the walls of corresponding holes in the bobbin 10. The bobbin 10, held by means of the said cover, is locked or unlocked axially, by means of the locking nut 46, which is joined to the end of shaft 40 by means of a spring washer 47. The nut 46 is screwed on a body 48 causing axial movement of the shaft 40 which serves for locking, or unlocking, the said bobbin 10, without preventing the bobbin 10 itself from rotating around its own axis. The shaft 41 cannot accomplish any axial displacement, but it can rotate around its own axis together with the bobbin 10. The rotation of the cover 43 is trans-mitted to a disc SQ by means of the shaft 41.
Referring to Figures 1 and 2 the support 9 is provided with holes 52 and 53 which are spaced apart from each other and which have their ohn axes parallel to one another and perpendicular to the longitudinal axis of support 9. In these holes, the braking means 19 of the bobbin 10 are mounted.
Inside the hole 53 in the support 9 is situated a shaft 60, hav-ing a greater length than the hole 53, so as to protrude with respect to hole 53. Near to one end of said shaft 60 are mounted arms 62. The arms 62 carry, on their facing surfaces, at their free ends, pads 63 which are in contact with the opposite surfaces of the disc 50 together with which they form the braking elements of the system.
The shaft 60 passes through the central holes of a series of Belleville washers 65, through the holes in the arms 62 and through the 10840z~
central hole of the cover 66 and is secured by a threaded nut 68. The nut 68 controls the compression forces of the washers 65 by means of the cover 66. This force is transmitted to arms 62 and thence, to the pads 63. The above arms 62, disposed as aforesaid, constitute a lever and can accomplish angular displacements by rotating around the shaft 60 on which they are pivotally mounted.
In the hole 52 there is mounted a shaft 69 which has its own axis parallel to the axis of the shaft 60. Gn this shaft 69 at its inner extremity there is mounted an element which is sensitive to the variations of the un-winding radius of the fine filaments 11 wound around the bobbin 10. This element is, an arm 70 which carries a roller 71 which idles about its axis and has a length such as to substantially cover the entire axial length of the surface covered by the fine filament 11. This roller is held in con-tact with said surface by means of a spring 72, the extremities of which are fixed respectively to the support 9 and to the free extremity 70' of the arm 70.
The shaft 69 on its extremity external to said support 9 is pro-vided with an arm 73 which is disposed in such a way as to be an extension of the arm 70. The arm 73 and the arms 62 are pivotally connected to a tie-rod 74 which interconnects them.
Since in general fine filaments to be laid up should not be sub-jected to stresses exceeding 100 gr., the contacting elements of the braking system ha~e been selected to have a friction coefficient not greater than 0.1.
In order to obtain such coefficient a coupling of material commonly known in the market by the name of "Teflon" with chromium-plated steel, i.e. pads 63 made of "Teflon" and the disc 50 made of steel with the surfaces specular and plated with chromium, may be used. This combination of braking means guarantees an insignificant static friction and an insignificant inertia iO84~Z4 force which follows when the apparatus is stopped.
In operation the bobbin 10 is braked by braking means 19 during its rotation around its own axis. The operation of braking means 19 is such that the arm 70 responds to the continuously diminishing radius of the winding of the fine filaments 11 by means of the roller 71.
As the filament 11 unwinds, the arm 70 moves towards the axis of the bobbin 10, helped in its displacement by the action of the spring 72. At the same time, this displacement is transmitted, in a way that is proportional to the lever constituted by arms 62, by means of the tie-rods 74 which connect the arm 73 to the free extremity of the said segments 62. The pads 63 are pressed against the disc surface 50 with a predetermined force, by means of the washers 65 con,pressed by the shaft 60, and the arm 70 through the tie-rod 74 chan~es the dimension of the radius of application of the braking force by the segments 62, said segments 62 moving said pads 63 from the edges to-wards the axis of the disc 50.
It will be apparent that the braking of bobbin 10 is such that the braking moment varies according to the variations of the dragging moment, which in turn, depends upon the variations of the unwinding radius of the filaments 11 on the bobbin 10. By diminishing the unwinding radius of the fine filaments 11, the application radius of the braking force is also diminished, thereby obtaining a substantially constant tension on the fine filaments 11 from the time the bobbin 10 is full until the time when the bobbin 10 is emptied. Accordingly, the fine filaments ll do not suffer any ~ariable stresses which could cause them to break. Another aspect which is relevant to this type of braking is that the brake itself renders negligible the difference between the friction value of the static friction, and the friction values in motion which determine the forces along the axis of the fine filament and during the stopping. Also, when starting the apparatus, little inertia is present which could otherwise cause abnormal stresses on the fine filament 11.
A ~
The present invention relates to braking devices suitable for use in unwinding thin elongated material from bobbins. The present invention has been found to be particularly suitable for use with apparatus of the type described in parent application number 286,037, i.e. apparatus for laying up, or helically winding together a plurality of fine filaments.
Herein the term "fine filaments" means filaments having a very low capacity for resisting the mechanical stresses to which they are conven-tionally subjected during the laying together procedure, such as for example, torsion, traction and flexing, which is due either to the dimensions of the said filaments, for example, their very small diameters, or else due to the very nature of the material out of which they are composed, e.g. glass yarn fiber.
Apparatus are well known for laying up a plurality of wires. Under normal operating conditions, such apparatus generally subject the wires to torsional, tractive and bending stresses from the moment the wires unwind from the bobbins which carry them, until they are layed-up together.
The braking devices used in the known apparatus, give rise to ten-sion stresses on the wires that are variable in a wide range of values. If, therefore, these braking devices are used for laying together fine filaments, as defined above, deformations can take place which may lead to some break-ages in said filaments.
It is the general object of the present in~ention to provide an improYed braking device suitable for use in unwinding thin elongated material from bobbins.
It is a further object of the present invention to provide an im-proved ~raking device suitable for use ~ith apparatus of the type described ~0840Z4 in parent application Serial Number 286,037, i.e. apparatus for laying up, or helically winding together a plurality of fine filaments.
According to the present invention there is provided braking means for bobbins which are mounted for rotation about a bobbin axis and have a winding of a filament thereon. The braking means comprises a disc co-axial with the bobbin axis and adapted to be coupled to a bobbin for rotation there-with, a braking lever mounted for pivotal movement around a first lever axis parallel to the bobbin axis and having an end engaging the disc at different radial positions thereon with pivotal movement of the lever, adjustable means urging the end of the lever against the disc, a control lever mounted for pivotal movement toward and away from the winding and having an end thereof urged toward and engaging the winding, and means interconnecting the control lever and the braking lever for causing the end of the braking lever to move nearer the bobbin axis as the winding decreases in radius.
The present invention will be better ~mderstood from the following erc/'~
1~ detailed description of a preferred embodiment thereof~ when D Figures lard2 are, respectively, side elevation and plan views of a bobbin braking apparatus;
Figure 3 is an enlarged, fragmentary cross-sectional view of the bobbin supporting apparatus shown in Figures land2 and is taken along the axis A-B indicated in Figure 2.
Referring to Figures 1 and 2 there is shown a support 9 on which a bobbin 10 is mounted. Said support 9 comprises a body 30 from which two parallel arms 31 extend, the arms being spaced apart from each other and having a length such as to contain the above said bobbin 10.
Referring to Figure 3, in each of said arms 31, there is formed a through-hole with its axis A-B perpendicular to the longitudinal axis of the support 9 itself. In said through-holes, there are disposed bushings 32 and 108~02~
33 respectively, in which are situated bearings 34 and 35 spaced apart from each other by means of the spacers 36 and 37 and maintained in position by means of circlips 38 and 39. The shafts 40 and 41 are mounted respectively, on bearings 34 and 35, and each has, on its extremity facing the longitudinal axis of the support 9, the cylindrical covers 42 and 43 that are received in the ends of the hollow core 44 of the bobbin 10.
In particular, the cover 43 is provided with teeth 45 which engage with the walls of corresponding holes in the bobbin 10. The bobbin 10, held by means of the said cover, is locked or unlocked axially, by means of the locking nut 46, which is joined to the end of shaft 40 by means of a spring washer 47. The nut 46 is screwed on a body 48 causing axial movement of the shaft 40 which serves for locking, or unlocking, the said bobbin 10, without preventing the bobbin 10 itself from rotating around its own axis. The shaft 41 cannot accomplish any axial displacement, but it can rotate around its own axis together with the bobbin 10. The rotation of the cover 43 is trans-mitted to a disc SQ by means of the shaft 41.
Referring to Figures 1 and 2 the support 9 is provided with holes 52 and 53 which are spaced apart from each other and which have their ohn axes parallel to one another and perpendicular to the longitudinal axis of support 9. In these holes, the braking means 19 of the bobbin 10 are mounted.
Inside the hole 53 in the support 9 is situated a shaft 60, hav-ing a greater length than the hole 53, so as to protrude with respect to hole 53. Near to one end of said shaft 60 are mounted arms 62. The arms 62 carry, on their facing surfaces, at their free ends, pads 63 which are in contact with the opposite surfaces of the disc 50 together with which they form the braking elements of the system.
The shaft 60 passes through the central holes of a series of Belleville washers 65, through the holes in the arms 62 and through the 10840z~
central hole of the cover 66 and is secured by a threaded nut 68. The nut 68 controls the compression forces of the washers 65 by means of the cover 66. This force is transmitted to arms 62 and thence, to the pads 63. The above arms 62, disposed as aforesaid, constitute a lever and can accomplish angular displacements by rotating around the shaft 60 on which they are pivotally mounted.
In the hole 52 there is mounted a shaft 69 which has its own axis parallel to the axis of the shaft 60. Gn this shaft 69 at its inner extremity there is mounted an element which is sensitive to the variations of the un-winding radius of the fine filaments 11 wound around the bobbin 10. This element is, an arm 70 which carries a roller 71 which idles about its axis and has a length such as to substantially cover the entire axial length of the surface covered by the fine filament 11. This roller is held in con-tact with said surface by means of a spring 72, the extremities of which are fixed respectively to the support 9 and to the free extremity 70' of the arm 70.
The shaft 69 on its extremity external to said support 9 is pro-vided with an arm 73 which is disposed in such a way as to be an extension of the arm 70. The arm 73 and the arms 62 are pivotally connected to a tie-rod 74 which interconnects them.
Since in general fine filaments to be laid up should not be sub-jected to stresses exceeding 100 gr., the contacting elements of the braking system ha~e been selected to have a friction coefficient not greater than 0.1.
In order to obtain such coefficient a coupling of material commonly known in the market by the name of "Teflon" with chromium-plated steel, i.e. pads 63 made of "Teflon" and the disc 50 made of steel with the surfaces specular and plated with chromium, may be used. This combination of braking means guarantees an insignificant static friction and an insignificant inertia iO84~Z4 force which follows when the apparatus is stopped.
In operation the bobbin 10 is braked by braking means 19 during its rotation around its own axis. The operation of braking means 19 is such that the arm 70 responds to the continuously diminishing radius of the winding of the fine filaments 11 by means of the roller 71.
As the filament 11 unwinds, the arm 70 moves towards the axis of the bobbin 10, helped in its displacement by the action of the spring 72. At the same time, this displacement is transmitted, in a way that is proportional to the lever constituted by arms 62, by means of the tie-rods 74 which connect the arm 73 to the free extremity of the said segments 62. The pads 63 are pressed against the disc surface 50 with a predetermined force, by means of the washers 65 con,pressed by the shaft 60, and the arm 70 through the tie-rod 74 chan~es the dimension of the radius of application of the braking force by the segments 62, said segments 62 moving said pads 63 from the edges to-wards the axis of the disc 50.
It will be apparent that the braking of bobbin 10 is such that the braking moment varies according to the variations of the dragging moment, which in turn, depends upon the variations of the unwinding radius of the filaments 11 on the bobbin 10. By diminishing the unwinding radius of the fine filaments 11, the application radius of the braking force is also diminished, thereby obtaining a substantially constant tension on the fine filaments 11 from the time the bobbin 10 is full until the time when the bobbin 10 is emptied. Accordingly, the fine filaments ll do not suffer any ~ariable stresses which could cause them to break. Another aspect which is relevant to this type of braking is that the brake itself renders negligible the difference between the friction value of the static friction, and the friction values in motion which determine the forces along the axis of the fine filament and during the stopping. Also, when starting the apparatus, little inertia is present which could otherwise cause abnormal stresses on the fine filament 11.
A ~
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Bobbin braking means for use with a bobbin mounted for rotation about a bobbin axis having a winding of a filament thereon, said braking means comprising a disc co-axial with said bobbin axis and adapted to be coupled to a bobbin for rotation therewith, a braking lever mounted for pivotal movement around a first lever axis parallel to said bobbin axis and having an end engaging said disc at different radial positions thereon with pivotal movement of said lever, adjustable means urging said end of said lever against said disc, a control lever mounted for pivotal movement toward and away from said winding and having an end thereof urged toward and engaging said winding, and means interconnecting said control lever and said braking lever for causing said end of said braking lever to move nearer said bobbin axis as said winding decreases in radius.
2. Bobbin braking means as set forth in claim 1 wherein said braking lever has a pad at said end thereof, said pad engaging said disc and hav-ing a size which is small relative to the radius of said disc.
3. Bobbin braking means as set forth in claim 2 wherein said pad and said disc are made of materials having a low coefficient of friction.
4. Bobbin braking means as set forth in claim 3 wherein said control lever comprises a roller at said end thereof, said roller being rotatably mounted on said control lever and adapted to engage said winding.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA335,499A CA1084024A (en) | 1976-09-03 | 1979-09-12 | Apparatus for laying-up together a plurality of fragile filaments |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT26807A/76 | 1976-09-03 | ||
| IT26807/76A IT1065925B (en) | 1976-09-03 | 1976-09-03 | APPARATUS TO GET THIN THIN FILAMENTS AMONG THEM |
| CA286,037A CA1071481A (en) | 1976-09-03 | 1977-09-02 | Apparatus for laying-up together a plurality of fragile filaments |
| CA335,499A CA1084024A (en) | 1976-09-03 | 1979-09-12 | Apparatus for laying-up together a plurality of fragile filaments |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1084024A true CA1084024A (en) | 1980-08-19 |
Family
ID=27165266
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA335,499A Expired CA1084024A (en) | 1976-09-03 | 1979-09-12 | Apparatus for laying-up together a plurality of fragile filaments |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1084024A (en) |
-
1979
- 1979-09-12 CA CA335,499A patent/CA1084024A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |