|Title of Invention||
CENTRIFUGALLY ACTIVATED BOBBIN COUPLING
|Abstract||The invention relates to a bobbin coupling for spindles of a textile machine. Said bobbin coupling comprises coupling buttons (1), which are inserted into radially orientated, undercut bores (6) in the shaft of the spindle (7). The respective coupling button (1) can be displaced in the bore (6) and is pressed by its outwards facing end against the inner wall of a bobbin (11) that has been placed on the spindle (7) with the aid of centrifugal force, to create a frictional connection between the rotating spindle (7) and the bobbin (11). The coupling button (1) comprises a groove (2), which runs around the periphery and into which a separate spring element is inserted. The spring element can be lowered into the groove (2) to mount the coupling button (1) and engages behind the undercut (10) once mounted. The bobbin coupling is used in spindles for spinning and winding machines.|
|Full Text||FORM 2
THE PATENT ACT 1970 (39 of 1970)
The Patents Rules, 2003 COMPLETE SPECIFICATION
[See Section 10, and rule 13)
TITLE OF INVENTION
CENTRIFUGALLY ACTIVATED BOBBIN COUPLING
70736 FELLBACH GERMANY
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed: -
PATENTS ACT 1977
VERIFICATION OF TRANSLATION
Certificate of Priority Document on the filing of a Patent Application.
File No. 10 2004 031 253.2
I, ASTRID TERRY, Translator of 11 Bounds Oaks Way, Tunbridge Wells, Kent, TN4 OUB, confirm that I am familiar with the English and German languages, and that to the best of my knowledge and belief the accompanying document which has been prepared by me, is a true translation of the authentic text of the Certificate of Priority Document on the filing of the Patent Application File No. 10 2004 031 253.2 dated 29th June 2004.
Signed this 16tndayof October 2006
The invention relates to a bobbin coupling according to the
preamble of claim 1.
Bobbin couplings are known from CH 4 64 751, in which a plurality of button-like entraining bodies are arranged, uniformly distributed about the spindle periphery, in blind holes. The entraining bodies called coupling buttons are configured so as to be hollow and hat-shaped. The coupling buttons consist of resilient material, so they can be introduced into the blind holes. In the installed state, they engage with their edges in undercuts, which are introduced into the blind holes. Together with the coupling buttons, one helical compression spring is inserted in each case into the blind holes. The helical compression spring constantly presses the coupling button outwards. The bobbin is held by spring force in this manner. The force, which has to be overcome, when placing on and removing the bobbin, is relatively great. As the coupling button is thin-walled, the mass of the coupling button is small. The force, with which the coupling button presses against the inner face of the bobbin, even during rotation of the spindle, is therefore applied substantially only by the spring force. The spring force must be at least so great that the bobbin is reliably entrained. This relatively high force may prevent the bobbin change if the empty bobbin to be placed on is to arrive in the operating position merely by its own weight and, for this purpose, has to push the coupling buttons into the blind holes perpendicularly to their movement direction counter to the spring force. During the doffing process on a spinning machine, both during removal and placing on, a strong frictional force has to be overcome. Owing to the friction
between the inside of the bobbin and the coupling button, wear may occur, which roughens the inside of the bobbin. The roughening increases the coefficient of friction between the bobbin and coupling button and, therefore the bobbin pressing force, even further during relatively long use. The sealing of the blind hole interiors against soiling is inadequate as the thin-walled coupling buttons frequently plastically deform non-uniformly during insertion and gaps between the blind hole surface and coupling button, which are formed in any case when the bobbin is placed on, may remain.
EP 0 517 341 Al shows an element for centring and fixing a bobbin on a spindle of a ring spinning machine. The bobbin is not fixed by coupling buttons, but instead by the polygonally configured elastic element. The element is elastically deformed when the bobbin is placed on the spindle and presses with its rounded corners against the inner wall of the bobbin. The force for fixing and entraining the bobbin is exclusively applied by spring force. As known, this relatively high force can hinder the bobbin change. During the doffing process of the spinning machine, a strong frictional force has to be overcome. As the force for fixing and entraining the bobbin has to be applied exclusively by means of the three corners of the elastic element on the inner wall of the bobbin, and therefore the corresponding contact face applying the force, between the element and bobbin is very small, the risk of roughening is even greater than in the above-described bobbin coupling from CH 464 751.
Solid coupling buttons, which are driven radially outwardly by centrifugal force on rotation of the spindle and are thus pressed against the inner wall of the bobbin, are an
alternative solution, which is also known from CH 464 751. The solid coupling buttons are introduced in each case into an axial cavity of the spindle and inserted by their cylindrical part from the inside out in bores. They are movably held in the bores. To hold them, the coupling buttons have retaining shoulders, the diameter of which is greater than the diameter of the cylindrical part of the coupling button. The partial configuration of the spindle as a hollow spindle is expensive. An additional protection against soiling of the spindle interior is required,- for example a specially configured closure cap with a cylindrical prolongation. The insertion of the coupling button requires skill and takes time. Apart from the outlay for assembly, the outlay for production, particularly for the spindle, is relatively large.
DE 44 30 709 Al describes a bobbin coupling for spindles, in which radial through-holes are provided. Two substantially cylindrical entraining bodies called centrifugal force bodies are fitted into the through-bores, in each case. The centrifugal force bodies have, at their end faces issuing from the radial through-bores, a convexly curved coupling face, in each case, with a conical contact face adjacent thereto, which are called shoulders. These shoulders are to prevent the centrifugal force bodies, during operation of the spindle, in other words during their rotation about the axis of rotation, from being hurled from the spindle running part, if for once no bobbin is to be placed on the spindle running part. For this purpose, a corresponding counter-face is associated with each shoulder on the outer periphery of the spindle running part. These counter-faces are formed by plastic deformation where the bore passes into the outer periphery of the spindle running part. The use of a tool with an embossing punch is
required for the deformation or caulking of the spindle running part in the course of inserting the entraining bodies. After the plastic deformation, it is impossible to remove the centrifugal force bodies from the bore without destruction. If the centrifugal force bodies are completely lowered into the bore when the spindle is at a standstill, dirt, such as, for example, dust or fibre pieces, can settle between the counter-face and centrifugal force body. On rotation of the spindle, the dirt can be pressed against the counter-face and can then only be removed again with great difficulty. This can lead to functional disturbances or functional failure of the bobbin coupling.
The generic DE 43 23 068 Al discloses a bobbin coupling, the entraining bodies of which configured as a thin-walled cap are also loaded by a helical compression spring. Additional mass bodies are inserted into the elastic deformable caps. The spring force of the helical compression spring and therefore the resistance when pushing on the bobbin when the spindle is at a standstill, can be kept lower and only be 30 to 70 percent of the value, which is generally required, for example, for an entraining body known from CH 464 751 loaded exclusively by a helical compression spring. When the spindle is at a standstill, during the doffing process., only the spring force acts as a pressing force for the cap onto the bobbin. The pressing force increases as the rotational speed increases owing to the centrifugal force acting on the additional mass. No slippage occurs between the spindle and bobbin despite the relatively low spring force owing to the additional centrifugal force. The sealing effect of the thin elastic caps is also inadequate here. The outlay for production and assembly is relatively high. The edges of the
cylindrically shaped body, which forms the additional mass, can cause heavy wear or even damage owing to the point-wise pressure loading on the thin caps in the course of time.
The object of the invention is, proceeding from the aforementioned prior art, to improve the configuration of bobbin couplings on spindles.
The object is achieved with a bobbin coupling with the features of claim 1.
Advantageous configurations of the invention are the subject of the sub-claims.
A bobbin coupling configured according to the invention is equipped with coupling buttons, which can be assembled easily, quickly and precisely dimensioned in the bores. Time consuming plastic deformation of the spindle with the aid of pressing tools during assembly of the coupling buttons is not necessary. It is also not necessary to configure the spindle, sometimes expensively, as a hollow spindle and to provide closure caps to cover the cavity of the hollow spindle. The coupling buttons according to the invention are robust and have low wear. The interior of the bores is effectively protected against soiling. If dirt should settle at the outer edge of the bore, this can be removed again by the coupling button. The coupling buttons are configured such that the centrifugal forces caused by their mass are alone sufficient for a reliable hold and entraining of the bobbin on rotation of the spindle. The spring elements secure the coupling buttons against falling out of the bore. A limited play of the
coupling button relative to the bore or to the spindle in the radial direction is thus retained. Insertion is easy to carry out.
The diameter of the cylindrical coupling button is slightly smaller than the diameter of the bore. At its end, which is directed inwardly during fitting, it has a peripheral groove, into which a separate spring element is inserted. The spring element preferably consists of spring wire and is advantageously configured as an oval ring. The ring is preferably open on one side. A ring of this type is economical and easy to produce. Assembly can be carried out easily and quickly. The width and depth of the groove are greater than the diameter of the spring wire, so the spring element can be completely received by the groove. When inserting the coupling button in the bore of the spindle, the spring element is compressed radially in such a way that it immerses in the groove of the coupling button. The compression of the spring element when introducing the coupling button into the bore is facilitated by the shape of the spring element configured as an oval and open ring and the circular cross-section of the spring wire. If the coupling button is inserted so deeply into the bore that the groove has reached the undercut of the bore, no further radial force acts on the spring element. The spring element therefore spreads apart again and acts as a reliable holder to prevent the coupling button falling out from the bore.
If the coupling button and the spring element form a preassembled module, only a small time expenditure is required for the preassembly of the coupling button and spring element and for insertion into the bore' of the spindle. Not only the
coupling button can be produced easily and with little outlay, but also the spring element cooperating with it. The preassembled module consisting in each case of the coupling button and spring element, after assembly, can be inserted into the respective bore of the spindle provided for this. The required outlay for the finished assembly is reduced. The coupling button and spring element can easily be joined and with little outlay.
A solid coupling button made of steel, which is preferably hardened, is wear-resistant and has a relatively large mass. Owing to its mass, it acts upon the inner wall of the bobbin particularly well with a force required to fix the bobbin, during rotation of the spindle.
A spindle, which is configured according to claim 7, allows a stable three-point hold and centring in a single plane with the minimum number of only three coupling buttons.
The preassembled module consisting in each case of the coupling button and spring element is also suitable for retrospective fitting in spindles, which already have suitable undercuts and can thus replace existing entraining bodies.
The bobbins can be easily placed on and removed from spindles, which are equipped with the bobbin coupling according to the invention. The coupling buttons do not exert any spring force, in the process, on the inner face of the bobbins.
The bobbin coupling according to the invention can be operated in a functionally reliable manner and with little soiling and
is wear-resistant. The embodiment is economical to produce and rapid and easy to assemble.
The invention will be described in more detail with the aid of the figures, in which:
Fig. 1 is a preassembled module, consisting of a coupling button and a spring element, in side view,
Fig. 2 shows the module of Fig. 2 in plan view,
Fig. 3 shows the module of Fig. 1 in a perspective view,
Fig. 4 shows a part section through a spindle with a bobbin coupling during installation of the coupling button,
Fig. 5 shows a part section through a spindle with a bobbin coupling after installation of the coupling button,
Fig. 6 shows a cross-section through a spindle with three coupling buttons in the operating position.
The preassembled module shown in Fig. 1 consists of a coupling button 1 and a spring element. The coupling button 1 has a groove 2, in which the spring element configured as an open ring 3 is placed. At the end opposed to the groove 2, the coupling button 1 has a convexly curved coupling face 4.
The oval form of the ring 3 can be seen in the plan view of the coupling button 1 of Fig. 2. The ring 3 is open between the free ends 5, the free ends 5 being clearly spaced apart from one another. The free ends 5 of the ring 3 are located in
the groove 2, as the view of Fig. 2 and the perspective view of Fig. 3 show. The part of the ring 3 opposing the open section is located completely in the groove 2. The shape of the ring 3, in conjunction with the groove 2, leads to a secure hold on the coupling button 1.
Fig. 4 shows the coupling button 1 during insertion into the bore 6 of the spindle 7. For this purpose, the preassembled module, consisting of the coupling button 1 and the open ring 3 is introduced with the end leading, on which the groove 2 is introduced, into the bore 6. The introduction is facilitated by a chamfer 12 on the edge of the bore 6. The coupling button 1 is pressed into the bore 6 by means of a force acting on the coupling face 4 in the direction of the arrow 8, until it has reached the base of the bore 6, for example. The ring 3 is acted upon in this, phase of insertion by pressing in with a force directed radially to the wall of the bore 6 and lowered completely in the groove 2. On reaching the undercut 10, no further radial force acts on the ring 3 and the latter spreads apart again in the undercut 10, as shown in Fig. 5. The ring 3 then assumes the oval shape again which is shown in Figs. 1 to 3. The coupling button 1 is therefore displaceably held in the spindle 7.
Fig. 6 shows the bobbin coupling, which in the embodiment shown is configured as a three point centrifugal force coupling. When placing the bobbin 11 on the spindle 7, coupling buttons 1 projecting, for example, from the bores 6 are pushed into the bores 6 of the spindle 7, with no spring forces having to be overcome. The coupling buttons 1 are located in the operating position, which is assumed when the spindle 7 rotates at operating speed. The coupling buttons 1
are pressed outwardly during the rotation by their coupling faces 4 under the action of centrifugal force against the inner wall of the bobbin 11. The bobbin 11 is thus effectively centred during operation with respect to the spindle 7 and reliably fixed in its position. To remove the bobbin 11, the spindle 7 is stopped. No further centrifugal force is exerted on the coupling buttons 1 and therefore no radial forces are exerted on the inner face of the bobbin. The bobbin 11 can now easily be removed again from the spindle 7.
The forces which occur owing to the coupling button l's own weight and can act so as to be directed radially outwardly are not able to eliminate the reliable hold of the coupling button 1 and release the coupling button 1 from the bore 6 of the spindle 7. The same applies to the centrifugal forces, which engage on the coupling button 1 when the spindle 7 rotates at operating speeds and no bobbin 11 is pushed onto the spindle 7. The spread apart ring 3, which engages behind the undercut 10, constantly ensures a secure hold in the spindle 7 and prevents unintentional release of the coupling button 1 from the bore 6.
WE CLAIM :
1. Bobbin coupling for spindles of a textile machine, wherein the bobbin coupling comprises coupling buttons, which are inserted in radially directed, undercut bores in the shaft of the spindle, the coupling buttons are displaceable in each case in their bore and are pressed by their outwardly directed end under the action of centrifugal force against the inner wall of a bobbin placed on the spindle in such a way that a frictional connection is produced between the rotating spindle and the bobbin, characterised in that the coupling buttons (1) have a peripheral groove (2), into which a separate spring element is inserted, which can be lowered into the groove (2) for assembly of the respective coupling button (1) and, after assembly, engages behind the undercut (10) .
2. Bobbin coupling according to claim 1, characterised in that the spring element is formed from spring wire.
3. Bobbin coupling according to claim 1 or 2, characterised in that the spring element is an oval ring (3).
4. Bobbin coupling according to any one of claims 1 to 3, characterised in that the spring element is an open ring
5. Bobbin coupling according to any one of claims 1 to 4,
characterised in that the coupling button (1) and spring
element form a module which can be preassembled.
Bobbin coupling according to any one of claims 1 to 5, characterised in that the coupling buttons (1) are made of hardened steel.
Bobbin coupling according to any one of the preceding claims, characterised in that the spindle (7) has at least three bores (6) to receive the coupling buttons (1), which are arranged in a plane transverse to the spindle axis uniformly distributed over the periphery of the spindle (7).
Dated this 13th day of November, 2006
HIRAL CHAMDRAKANT JOSHI AGENT FOR
1359-mumnp-2006-power of attorney(22-4-2003).pdf
|Indian Patent Application Number||1359/MUMNP/2006|
|PG Journal Number||39/2008|
|Date of Filing||14-Nov-2006|
|Name of Patentee||TEXPARTS GMBH|
|Applicant Address||MARIA-MERIAN-STRASSE 8, 70736 FELLBACH, GERMANY|
|PCT International Classification Number||D01H 7/16|
|PCT International Application Number||PCT/EP05/003927|
|PCT International Filing date||2005-04-14|