GB2110731A - Fastening device for retaining bobbins on spindles - Google Patents

Abstract

A bobbin-spindle is provided with a quick-release fastening device for securing a retaining plate 10 while allowing axial movement of the latter in response to expansion of bobbins or cops. A rod 18 is fitted to one end of the spindle 11 and has a peripheral groove 27. A sleeve 19 can slide on the rod 18 and carries locking balls 26 and a slidable locking ring 28 normally held by a spring 35 in a position in which it holds the balls projecting inwards into the groove 27. The sleeve 19 also carries a compression spring 22 urging downwards a ring 21 which can slide on the sleeve 19 and holds down the retaining plate 10, so that the latter can move against the action of the spring 22. For release, the operator lifts the ring 28, thereby releasing the balls 26 from the groove 27 and pulling the entire assembly consisting of the sleeve 19 and associated components off the rod 18. To refasten the retaining plate 10, the assembly consisting of the sleeve 19 and the components carried by it is pushed onto the rod 18, until the balls 26 engage the groove 27, in which they are locked by the locking ring 28. <IMAGE>

Description

SPECIFICATION Quick-release fastening device for retaining bobbins on spindles This invention relates to devices for mounting and firmly holding a plurality of bobbins stacked coaxially one on another, on a spin dIe Such arrangements are used for example when cops of yarn wound on the bobbins are to be treated for example by dyeing, drying, or otherwise.

The dyeing and drying of cops mounted in the described manner on spindles is a common practice. A problem which arises is that in the course of the dyeing and subsequent drying of the yarn, the cops undergo changes in axial dimensions, depending on the quality of the material forming the yarn, and the temperatures and processes used in treating it.

If the spindle has simple fixed bobbin-retaining elements at its ends, the changes in axial dimensions of the cops may lead to damage to the cops or the spindle and retaining elements if the cops expand axially; conversely if the cops contract, a gap appears at one or both ends of the spindle between the cops and the bobbin-retaining elements, which can increase the flow of dyestuff solution through the bobbins, leading to uneven dyeing and impaired thermal economy due to the increased flow.

The axial expansion and/or contraction can be accommodated by resilient mounting of one of the bobbin-retaining elements, but existing devices for this purpose are unsafe and time-consuming in use.

An object of the present invention is to provide a fastening device for a bobbin-retaining element used to secure a plurality of bobbins on a spindle, which device is capable of accommodating axial expansion and contraction and can be readily and securely attached to and detached from the spindle by a simple manual operation.

According to the present invention, there is provided a fastening device for securing a bobbin-retaining member to a spindle while allowing thermal expansion of bobbins mounted on the spindle, which device comprises: a locking rod capable of being firmaly secured at one end thereof to a bobbin-holding spindle so as to extend axially from an end of the spindle, said locking rod having an annular groove therein; a sleeve slidably fitted on said locking rod which sleeve has a plurality of ball-holding holes provided in it in association with said annular groove, and balls in the said holes; a ring mounted slidably on the outer periphery of said sleeve adjacent to the said end of the locking rod, which ring is adapted to be firmly secured onto the upper end of a said bobbin-retaining member;; a spring-supporting member secured to said sleeve at a position axially spaced from said slidable ring; a compression spring interposed between said slidable ring and spring-supporting member, said spring urging the slidable ring axially to apply, in use, axial pressure to bobbins mounted on the said spindle and serving to absorb expansion of the bobbins; a slidable locking member mounted on the outer periphery of the sleeve and positioned on that side of the spring-supporting member remote from the said one end of the locking rod, the locking member being slidable freely along the sleeve; a spring seat on the sleeve, on that side of the locking member remote from the said one end of the locking rod; and a second compression spring provided between said locking member and spring seat; said balls being held between the annular groove of the locking rod and the inner surface of the locking member, and said balls being disengageable from or engageable with the annular groove by axial sliding of the locking member away from or towards the said one end for releasing from the locking rod, or securing to the locking rod, the unitary assembly comprising the sleeve, locking member, slidable ring, spring-supporting member, and springs.

The invention will be further described with reference to the accompanying drawings, in which: Figure 1 is a schematic elevational view of a prior art bobbin holding device; Figure 2a and Figure 2b are each an elevational view in cross-section of one example of a fastening device according to this invention, respectively showing the state where the balls are engaged, and the state where the balls are disengaged; Figure 3 is a sectional elevational view of the same device as Figs. 2a and 2b showing the state of the fastening device when the retained bobbins have expanded during treatment; and Figure 4 is an enlarged sectional view of the ball portion of a device embodying this invention.

The known bobbin holder shown in Fig. 1 comprises a tubular spindle 1 with a lower bobbin-retaining plate or disc 3. A plurality of cops 2' are mounted one on another, coaxially on the spindle, resting on the plate 3. At the upper end of the spindle, an upper retaining plate or disc 4 rests on the uppermost cop. It can slide along the spindle and is pressed against the stack of cops by a compression spring 6 seated against a washer 5 retained by an internally threaded member 7 screwed on to the end of the spindle. Because the retaining element 4 is movable and springloaded by the spring 6, it can accommodate expansion or contraction of the cops in the axial direction. If the cops expand, the spring is compressed but the contact pressures between the cops or bobbins do not rise as much as if these were fixed in place on the spindle.Consequently expansion of the cops does not impede flow of the dyestuff through the bobbins, and adequate heat transfer is maintained. Conversely if the cops contract, the spring expands and therefore a gap between the uppermost cop and the retaining element 4 does not arise.

However, the device shown in Fig. 1 is not easy to use. To remove a set of bobbins and fit another set on the spindle, requires a troublesome, complicated and laborious series of operations. The nut 7 has to be unscrewed by means of a bar inserted into a transverse hole 8 and the components 4, 5, 6 have to be removed by hand. There is a risk that when the nut 7 comes free from the spindle, the spring 6 and washer 5 will fly off because of the stress stored in the spring. This may injure the operator or lead to loss of these components. To fix a fresh set of bobbins on the spindle, the components 4 to 7 have to be fitted to the spindle in sequence and the nut 7 has to be screwed down. Another problem is that the threads on the nut 7 and on the end of the spindle 1 become worn with repeated use.Furthermore, the contact pressures between adjacent bobbins depend on how tightly the nut 7 is screwed down, so that great care must be taken in the operation.

In contrast, the present invention provides a fastening device for the top retaining element, which allows axial expansion or contraction but can be removed and refastened by a single simple manual operation, which may require the use of only one hand.

Fig. 2a shows a device embodying the invention fitted to a bobbin-carrying spindle 11. The device is shown in its operating condition but bobbins are not shown in Fig. 2a.

The spindle 11 carries a lower retaining plate 9 secured by screw threads to a threaded portion 14 on the end of the outer peripheral surface of a sleeve 13, which is threaded on to a threaded lower end portion 1 2 of the spindle 11 notched at the lower end thereof.

The fixed sleeve 1 3 threaded on the threaded portion 1 2 at the lower end of the spind 11 can be sufficiently secured to the spindle 11 by threading the lower spacer 9 onto the threaded portion 1 4 on the outer periphery thereof, as shown in Fig. 3.

However, in order to more efficiently and securely hold the spindle 11 there may be provided a spindle clasping member 50 as illustrated in Fig. 2a. The spindle clasping member 50 has a central hole 51 and is a short cylindrical member haing a flange portion 50a of a larger radius at the upper end thereof. An annular plate 53 is attached to the upper end of the member 50 by means of a screw thread 55 so as to be finely adjustable up or down with the aid of a contact-pressure regulating bolt 52.In the inner periphery of the annular plate 53, there are provided engaging members 54 protruding radially inwardly at intervals of 1203. The engagement members 54, by rotation when the member 50 is fitted over the fixed sleeve 1 3, shift above projecting portions 1 3a provided on the outer periphery of the fixed sleeve 1 3 and matching the engagement members 54. In this way, the spindle 11 can be firmly held and fitted to the lower spacer 9 using one hand. A stop 56 prevents excess rotation of the member 50.

The upper end of the spindle has an inter nal thread 1 5 into which is screwed an adaptor plug 16. The plug 1 6 has a central hole with a screw thread 17, into which is screwed a cylindrical locking rod 1 8 coaxial with and projecting from the upper end of the spindle 11.

A cylindrical sleeve 19 is fitted on the rod 1 8 and can slide freely along the latter. At the lower end of the sleeve, a stop ring 24, for example a spring clip, is attached to the sleeve and retains a ring 21 which can slide axially along the outer surface of the sleeve 19. An upper stop ring 23 is secured to the outside of the sleeve, at a position spaced axially above the lower stop ring 24. The upper stop ring 23 forms an abutment for a cup-like spring seat 20 which faces downwards, and a helical compression spring 22 encircles the sleeve 19, between the seat 20 and the ring 21, so as to urge the latter downwards. The seat 20 can also slide along the sleeve.

The ring 21 is tightly secured to the central region of an upper bobbin retaining plate 10 for example by an intervening sleeve or collar, so that the retaining plate 10 can move axially relative to the spindle 11 but is normally urged downwards by the spring 22.

The locking rod 1 8 has an annular groove 27, and the corresponding region of the sleeve 1 9 has radial holes 25 which contain balls 26, above the upper stop ring 23. These balls are retained by the internal surface 29 of a sliding ring 28 which can slide up and down the upper part of the sleeve 1 9. The diameter of the balls is greater than the wall thickness of the sleeve 19. Consequently when the sliding ring 28 is in its lowest position, resting on the upper stop ring 23, the balls project radially inwards from the internal surface of the sleeve 1 9 into the annular groove 27, thereby locking the sleeve 1 9 against axial movement on the rod 1 8.

The sliding ring 28 is pressed down by a compression spring 35 housed in an internal recess 33 in the ring 28. A flange ring 31 is threaded on the threaded top 30 of the sleeve 19, and the spring 35 acts between the lower end 32 of the flange ring 31, and the lower end 34 of the recess 33.

As is best seen in Fig. 4, the lower end 36 of the sliding ring 28 has a bevelled surface 37 at the bottom of its internal bore. When the ring 28 is raised to its uppermost position, abutting on the flange 38 of the flange ring 31, the bevel 37 comes into line with the balls 26 so that these can move radially outwards to a limited extent, sufficient for them to move clear of the groove 27 in the rod 1 8. In this condition, which is shown in Fig. 2b, the sleeve 1 9 is no longer locked to the rod 1 8 and can be moved axially relative to the latter. The distance between the bottom edge 39 of each hole 25, and the lower end 40 of the ring 28 when raised, is such that the balls cannot fall out of the holes 25.

To urge the balls outwards, the groove 27 has oblique side surfaces 27' (Fig. 4). Accordingly, when the ring 28 is iifted it will initially compress the spring 35. As it moves clear of the balls 25, the latter, being pressed against the upper oblique surface 27' of the groove 27, are pushed radially outwards so as to unlock the sleeve 1 9 from the rod 18, and the entire assembly consisting of the sleeve 1 9 and all the components mounted on it slides axially off the rod 1 8. The operator need carry out only a single one-handed operation namely pulling the ring 28 upwards.

The unlocking and separation of the sleeve 1 9 and associated components from the rod 1 8 then follow automatically. Thus, the upper retaining plate 10 and the associated fastening device form a unitary assembly which can be removed from the spindle using one hand.

After the bobbins have been removed from the spindle 11 and fresh bobbins have been fitted onto the spindle, the retaining plate 10 and its fastening device are fitted onto the spindle end. The operator must raise the slidable locking ring 28 when the fastening device is fitted onto the rod 1 8. Once the balls 25 have been fitted over the rod 18, the fastening device comprising the sleeve 1 9 and associated components is simply pushed down the rod 1 8 until the balls 25 come level with the grooves 27. The force exerted by the spring 35 will then cause the ring 28 to descend and push the balls 25 into the groove 27. Alternatively, the movement of the ring 28 can be controlled by the operator throughout.The sleeve 1 9 is thereby locked onto the rod 18, and the retaining plate 10 is thus secured on the end of the spindle 11, in the condition shown in Fig. 2a.

In this condition, with the set of bobbins firmly fastened on the spindle, cops can be wound onto the bobbins. Alternatively, the bobbins can be wound before being fitted onto the spindle.

The retaining plate 10 can be integral with or securely fastened to the ring 21, for convenience in that the retaining plate is thus removed from the spindle and replaced as part of the operation of unlocking or replacing the fastening device. Alternatively, the retaining plate can be a separate component, for example to facilitate the use of retaining plates of different sizes.

After instailation of bobbins and provision of cops, the yarn can be treated for example by passing a dyestuff solution through the bobbin assembly in the usual manner. The dyed cops are subsequently dried.

Dyeing commonly causes the bobbins and the layers of yarn on these to expand axially against the upper retaining plate. The ring 21, contiguous with the upper retaining plate 10, is thereby forced away from the lower stop ring 24, against the action of the spring 22, thereby allowing expansion while maintaining the retaining plate in close contact with the uppermost bobbin or cop. This condition is shown in Fig. 3. Because the locking mechanism is above the upper stop ring 23, these movements do not affect the locking.

Any subsequent axial contraction is accompanied by downward movement of the retaining plate 10 under the action of the compression spring 22. The retaining plate 10 always remains in close contact with the cops or bobbins and also with the ring 21, thereby preventing any leakage of dyestuff solution, drying liquid or steam air.

It will be readily understood that the described device provides reliable locking while allowing axial expansion and contraction, and furthermore can be released and removed, or fitted and locked, as a unit, in a quick and simple operation requiring the use of only one hand. Because all the components of the fastening device form a single unitary assembly, there is no risk of components being lost, or damage or injury being caused because of sudden expansion of springs on release. Fastening and unfastening does not require a screwing or unscrewing operation, and therefore the fastening device does not suffer from the deterioration associated with repeated use of screw threads.

Fig. 4 shows some additional details of the locking mechanism. Each ball hole 25 has a lip 41 at its radially inner end, defining an aperture 42 of a diameter slightly less than that of the ball, so that the balls cannot fall out of the holes 25 into the interior of the sleeve 1 9. The diameter of the aperture 42 is only siightly less than that of the ball, so that the ball can project radially inwards into the bore of the sleeve 1 9. In the locked condition, the surface of the ball is tangential to the sloping side walls 27' of the groove 27.

The shaping of the groove 27 affects the ease with which the balls 26 become disengaged from the groove when the locking ring 28 is raised, and also the firmness with which the sleeve 1 9 is held in place when locked. It is important that when locked, the sleeve 1 9 should not have any appreciable axial movement on the rod 18, but also it is necessary that the balls should easily disengage themselves from the groove, when unlocked. In order to optimise both the locking and unlocking functions, the angle 0 between the groove side wall 27', and the radial direction normal to the surface of the rod 1 8, is preferably 30G to 40'; the most suitable angle is 35G.

Claims (4)

1. A fastening device for securing a bobbin-retaining member to a spindle while allowing thermal expansion of bobbins mounted on the spindle, which device comprises: a locking rod capable of being firmly secured at one end thereof to a bobbin-holding spindle so as to extend axially from an end of the spindle, said locking rod having an annular groove therein; a sleeve slidably fitted on said locking rod which sleeve has a plurality of ball-holding holes provided in its in association with said annular groove, and balls in the said holes; a ring mounted slidably on the outer periphery of said sleeve adjacent to the said end of the locking rod, which ring is adapted to be firmly secured onto the upper end of a said bobbin-retaining member; a spring-supporting member secured to said sleeve at a position axially spaced from said slidable ring;; a compression spring interposed between said slidable ring and spring-supporting member, said spring urging the slidable ring axially to apply, in use, axial pressure to bobbins mounted on the said spindle and serving to absorb expansion of the bobbins; a slidable locking member mounted on the outer periphery of the sleeve and positioned on that side of the spring-supporting member remote from the said one end of the locking rod, the locking member being slidably freely along the sleeve; a spring seat on the sleeve, on that side of the locking member remote from the said one end of the locking rod; and a second compression spring provided between said locking member and spring seat; said balls being held between the annular groove of the locking rod and the inner surface of the locking member, and said balls being disengageable from or engageable with the annular groove by axial sliding of the locking member away from or towards the said one end for releasing from the locking rod, or securing to the locking rod, the unitary assembly comprising the sleeve, locking member, slidable ring, spring-supporting member, and springs.

2. A fastening device as claimed in claim 1, wherein said annular groove of the locking rod has a surface at an angle of about 35 to the normal to the rod surface.

3. A fastening device as claimed in claim 1 or 2 in which the second spring is housed in a recess provided in the internal surface of the locking member.

4. A fastening device for a bobbin-hoiding spindle, substantially as herein described with reference to Figs. 2a to 4 of the accompanying drawings.