More particularly, the invention relates to an arrangement in which a chain section, that lies close to the bobbin during the chain infeed sequence, is caused to pass via a deflection point.

Although the present invention can be applied to or in any technical field in which it is desired to wind a chain, consisting of a series of links, onto a chassis- carried bobbin, it should be mentioned that the invention has been developed to form part of a method and part of an apparatus for the production of non-allergenic objects, and then particularly metallic objects that are intended to come into direct contact with the skin of human beings.

Examples of such objects are chain necklaces, ankle chains or chain bracelets, etc., where said objects contain completely pure metals, such as pre- cious metals, e. g. gold, silver, platinum, palladium, rhodium, etc., mixed with opti- mised pure zinc, copper, aluminium, nickel or chromium, and wherein all working processes are carried out without access to air and without contact with aggres- sive substances, such as salts or acids.

Description of the background art There are different arrangements for winding a chain consisting of a series of links onto a chassis-carried bobbin known to the art.

In the case of such arrangements, it is also known to allow the bobbin to move forwards and backwards axially, in relation to the chassis, such that conse- cutive turns of the chain will lie tightly together between the end-walls of the bob- bin in a first layer, and also in additional second, third and further layers.

It is also known to deflect a chain section that lies close to the bobbin dur-

ing the infeed sequence.

With regard to an arrangement constructed for the aforesaid use and in the case of a chain that has a more rectangular cross-sectional shape, with at least planar and parallel top and bottom surfaces, and which shall be wound onto a bobbin, it is necessary that the chain links are caused to lie tightly together dur- ing each turn of the bobbin, so as to form a layer between the end-walls of the bobbin.

An arrangement for winding a wire onto a bobbin is known from Patent Publication DE-B1-1 210 650.

This prior publication illustrates and describes an arrangement with which a bobbin (1) can be displaced axially when winding a wire, an electrically insulated conductor, or cable, onto the bobbin.

The bobbin is carried by a chassis (1) and is adapted for axial movement back-wards and forwards as the wire is wound onto the bobbin.

The publication also discloses that the wire shall pass a guide unit and a deflecting point prior to the bobbin taking over the actual winding process.

The wire shall be stretched, parallel with an inwardly facing surface of one end-wall, during each layer-forming turn of the bobbin, wherewith each wire part entering the bobbin will adopt one and the same position or angle, which is per- pendicular to the rotational axis of the bobbin.

The wire is also caused to extend parallel with said end-wall during the major part of a turn or revolution, wherein the bobbin is able to move rapidly in a first direction within a very short rotational path in a first direction through a dis- tance corresponding to the width of the wire (not the chain width) and a predeter- mined value ("a") added thereto, and stay in this position during the remainder of an adjacent turn, a second turn.

Summary of the invention Technical problems When taking into consideration the technical deliberations that a person skilled in this particular art must make in order to provide a solution to one or more technical problems that he/she encounters, it will be seen that on the one hand it is necessary initially to realise the measures and/or the sequence of measures that must be undertaken to this end, and on the other hand to realise which means

is/are required to solve one or more of said problems.

On this basis, it will be evident that the technical problems listed below are highly relevant to the development of the present invention.

When considering the present state of the art, as described above, it will be evident that in respect of an arrangement for winding a chain, consisting of a series of links, onto a chassis-carried bobbin, a technical problem resides in the ability to provide conditions which enable the bobbin to move backwards and for- wards accurately in an axial direction during a chain-winding sequence, so that the chain links can be wound tightly adjacent each other between the end-walls of the bobbin during each turn of the bobbin, and also in further successive layers.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by taking particular link-guiding measures adjacent the end-walls of the bobbin, so as to position the links and said turns close to- gether adjacent said end-walls.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by deflecting a chain section or extension to a par- ticular position of orientation upstream of the bobbin.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by causing said section, situated close to the bob- bin, to extend parallel with an inwardly facing surface of an end-wall during a major part of a first turn, and to cause the bobbin to be displaced in a first direction through a distance corresponding to the width of the chain, during the remainder of said first turn, and also to cause the bobbin to be moved in a second direction dur- ing an adapted part of a second turn following said first turn.

Another technical problem resides in the ability to realise the significance of and the advantages associated with allowing said displacement of the bobbin in said second direction to be adapted such that the chain section, close to said bob- bin, will define an acute angle with said surface.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by allowing said acute angle to deviate from a right angle at a distance of one chain width from a chosen reference point outside the bobbin.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by locating said reference point at a distance from

the rotational axis of the bobbin, corresponding to 2.0 to 4.0 times the radius of the bobbin end-wall.

Another technical problem resides in the ability to realise the significance of and the advantages associated with providing a length measuring or distance measuring device, which will function to measure a chosen distance between a fixed point on said chassis and said chain section, oriented or situated close to the bobbin.

A further technical problem resides in the ability to realise the significance of and the advantages afforded by adapting said length measuring device such that, from a second or a third turn, when the distance measured deviates from a predetermined value, said bobbin is displaced axially through the medium of a control unit such as to obtain said predetermined distance.

A further technical problem resides in the ability to realise the significance of and the advantages afforded by enabling the bobbin to be displaced in a first di- rection through a distance corresponding to the width of the chain at a last winding turn in a first layer adjacent an opposite end-wall during the remaining part of said last winding turn.

Yet another technical problem resides in the ability to realise the signifi- cance of and the advantages afforded by allowing a first turn of an overlying sec- ond layer to be situated adjacent said end-wall, and to cause said chain section close to the bobbin to extend parallel with an inwardly facing surface of the end- wall during a major part of a first turn, and to adapt the bobbin for displacement in a second direction through a distance corresponding to the width of the chain dur- ing the remainder of said first turn.

A technical problem also resides in the ability to realise the significance of and the advantages associated with allowing the bobbin to be displaced in a sec- ond direction during an adapted part of a second turn adjacent said first turn.

A further technical problem resides in the ability to realise the significance of and the advantages associated with adapting displacement of the bobbin in said first direction so that the chain section close to the bobbin will define an acute an- gle with said surface.

Another technical problem resides in the ability to realise the significance of and the advantages associated with causing said acute angle to deviate from a right angle a distance of one chain width from a chosen reference point externally

of the bobbin.

Still another technical problem resides in the ability to realise the signifi- cance of and the advantages afforded by locating said reference point at a dis- tance from the rotational axis of the bobbin corresponding to 2.0 to 4.0 times the radius of a bobbin end-wall.

A further technical problem resides in the ability to realise the significance of and the advantages afforded by adapting said device for measuring a distance between a chassis-carried fixed point and said chain section close to said bobbin, said distance differing from an earlier detected distance.

A further technical problem resides in the ability to realise the significance of and the advantages afforded by adapting the device to allow the bobbin to be displaced axially when said device measures a distance that differs from a prede- termined value, during a second or a third turn, via a control unit so as to obtain the predetermined distance.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by enabling the bobbin to be displaced in a second direction through a distance corresponding to the chain width at a last winding turn within a second layer adjacent an end-wall of the bobbin, during the remaining por- tion of the last winding turn.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by adapting the device to measure a distance be- tween a chassis-carried fixed point and said chain section at an orientation or a place adjacent said deflecting point.

Yet another technical problem resides in the ability to realise the signifi- cance of and the advantages afforded by effecting said deflection with the aid of a fixed, smooth axle part.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by effecting said deflection with the aid of a cylin- drical or at least partially cylindrical centre part having two rounded edge-associ- ated and flange-connecting parts.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by using an ultrasound-based device.

A further technical problem resides in the ability to realise the significance of and the advantages afforded by adapting a control unit that co-acts with the de-

vice to cause the bobbin to move in a direction towards the chassis in response to an increase in a distance, related to a predetermined value.

A further technical problem resides in the ability to realise the significance of and the advantages associated with enabling axial displacement of the bobbin to be controlled in response to given data or information, such as the location of a first bobbin end-position, a second bobbin end-position, a current chain width, a position notation concerning the instant rotational position of the bobbin, a chosen bobbin-length between mutually opposite surface parts of the end-walls, a chosen rotary speed of the bobbin and/or a distance measurement.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by allowing the bobbin to co-act with an axle, which drives the rotational movement through the medium of a first motor and drives the axial movement through the medium of a second motor.

Another technical problem resides in the ability to realise the significance of and the advantages that are associated with positioning said deflection point within an area situated close to an end-wall part and therewith create conditions for flexible distribution of the closely packed turns with chain-associated edge sur- faces in mutual abutment.

Yet another technical problem resides in the ability to realise the signifi- cance of and the advantages afforded by providing, adjacent to and upstream of said deflection point, a device that is adapted to measure a distance between a chassis-fixed point and a bypassing chain section.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by displacing the bobbin axially in a controlled manner to obtain a specific distance value, when the distance measured deviates from a pre-determined value.

Another technical problem resides in the ability to realise the significance of and the advantages afforded by effecting said deflection through the medium of a fixed, smooth axle part, preferably an axle part provided with small edge flanges.

Solution The present invention thus relates to an arrangement for winding a chain, consisting of a series of links, onto a chassis-carried bobbin, wherein said bobbin is arranged to move axially backwards and forwards during a chain-winding se-

quence so as to enable the chain links to be positioned tightly against each other in mutually adjacent turns and in general have the qualifications given in the intro- duction.

The aforesaid chain section, situated close to the bobbin, is intended to extend parallel to an inwardly facing surface of an end-wall part during a major part of a first chain-winding turn.

With the intention of solving one or more of the aforesaid technical prob- lems, it is proposed, in accordance with the present invention, that the bobbin is adapted for displacement in a first direction through a distance corresponding to the width of the chain during the remaining part of said first winding turn, and adapted to be displaced slightly in a second direction during an adapted part of a second winding turn adjacent said first turn.

By way of proposed embodiments, that lie within the scope of the present invention, it is also proposed that displacement of the bobbin in said second direc- tion is adapted so that the chain section, lying close to the bobbin, will define an acute angle with said surface.

This acute angle may be adapted to deviate from a right angle a distance of one chain width from a chosen reference point externally of the bobbin.

This reference point is situated at a distance from the rotational axis of the bobbin, corresponding to 2.0 to 4.0 times the radius of a bobbin end-wall.

The arrangement includes a length-measuring device, which functions to measure a distance between a fixed point on the chassis and the chain section that lies close to the bobbin.

From a second or a third turn, the length-measuring device is adapted to allow the bobbin to be displaced through the medium of a control unit so that said specific distance can be obtained in the event of said distance deviating from a predetermined value.

During the end-wall adjacent last winding turn of a first layer, the bobbin is caused to be displaced in a first direction through a distance corresponding to the width of the chain for the remaining part of said last winding turn.

With respect to the end-wall-adjacent first turn of an overlying second layer, deflection is effected within a central region of the chain section situated close to the bobbin and the deflection point is orientated so as to provide a deflec- tion angle of less than 160 degrees in the event of a full bobbin.

Deflection is achieved with a fixed, smooth axle, such as one having a cy- lindrical or at least partially cylindrical centre part having at least one, preferably two, rounded and flanged edge-portions.

The length-measuring device is an ultrasound-based device.

Co-acting with the length-measuring device is a control unit, which causes the bobbin to be displaced in a direction towards the chassis when the distance measured has increased in relation to a predetermined value.

The chain section deflection point is situated between a central region of said chain section situated upstream of the bobbin and is orientated to provide a deflection angle smaller than 160 degrees even when the chain extension has filled the bobbin.

Advantages Those advantages primarily characteristic of an inventive arrangement re- side in the provision of conditions for enabling, via adapted axial displacement of a bobbin in relation to a chassis, conditions to be created such that the links of a chain will be situated in height relationship in respective turns around the bobbin, by deflecting the chain section in an upstream central region of said section, and by measuring the distance between a chassis-associated fixed point and respec- tive chain sections, so as to create conditions, via a measured distance and con- trol unit actuated thereby, in which the bobbin is moved axially in accordance with a determined pattern so that a predetermined distance is obtained.

The primary characteristic features of an arrangement constructed in ac- cordance with the present invention are set forth in the characterising clause of the accompanying claim 1.

Brief description of the drawings An arrangement at present preferred for winding a chain, consisting of a series of links, onto a chassis-carried bobbin will now be described in more detail by way of example with reference to the accompanying drawings, in which; Figure 1 is a side view of the inventive arrangement; Figure 2 is a perspective illustration of the co-action between a bobbin, a chain-deflecting element and a chain section that lies close to the

bobbin; Figure 3 is a slightly enlarged side view of the chain deflection ; Figure 4 is a horizontal view illustrating the bobbin affixed in the chassis and showing means for displacement of the bobbin axially in relation to the chassis during controlled rotation; Figure 5 is a highly simplified illustration of a control unit required in accor- dance with the invention; Figure 6 illustrates different sequences in the axial control of the bobbin re- lated to a number of turns and layers; and Figure 7 is a graph representing axial bobbin movement in relation to the chain turns wound onto the bobbin.

Description of embodiments at present preferred It will be noted that in the following description of an exemplary embodi- ment at present preferred and having the significant characteristic features of the invention illustrated in the various figures of the accompanying drawings, there have been used particular terms and particular terminology with the primary inten- tion of clarifying the inventive concept.

However, the expressions and terms used shall not be seen as limiting the scope of the invention, and it will be understood that each term chosen shall be in- terpreted to include all technical equivalents that function in the same or essential- ly the same way, so as to be able to achieve the same or essentially the same in- tention and/or technical effect.

As before mentioned, fig. 1 is a highly simplified illustration in side view of an arrangement 1 for winding a chain 4 consisting of a series of links and chain sections onto a bobbin 3 carried by a chassis 2.

The bobbin 3 is axially movable to and fro in relation to the chassis 2 dur- ing a chain-winding sequence, as will be described in more detail below with refer- ence to figs. 4,5,6 and 7.

Axial displacement of the bobbin is intended to provide controlled to and fro movement of the bobbin 2, so that the links and chain sections in the chain 4 will be positioned tightly adjacent each other in related turn between end-wall parts 3a, 3b of the bobbin, within a first layer 48, a second layer 49 orientated over said first layer, a third layer and further layers, as indicated by reference numerals 41,

42, and 43.

The chain section 4a, situated close to the bobbin and fed into said bobbin 3 by virtue of bobbin rotation, is arranged to first pass a unit 5, which functions to guide said chain section 4a and which serves as a fixed point 5', wherein the chain section 4a is arranged to pass via a deflection point 6, situated between the unit 5 and the bobbin 3.

The deflection point 6 will preferably in practice be placed much closer to the bobbin end-wall than shown in the figures.

A chain section 4a'is orientated between the unit 5 and the deflection point 6, and a further chain section 4a"is orientated between the deflection point 6 and the bobbin 3.

As will be seen in figs. 1 and 2, the deflection point 6 is situated within a central region of the chain section 4a and is orientated to provide a deflection an- gle"a"of less than 160 degrees, even when a bobbin 3 is filled by chain exten- sions (fig. 3).

The deflection angle"b"shall be greater than 110 degrees, when the bob- bin is empty.

Consequently, the deflection angles ("a"-"b") may vary during the chain- winding process within a range of 20-40 degrees, such as between 110 degrees and 140 degrees, for instance.

Provided adjacent the deflection point 6 and facing towards the fixed point 5'is a length-measuring device 7, which functions to measure a distance between a chassis-associated fixed point and said chain section.

When the distance (c) measured (fig. 4) deviates from a predetermined value the bobbin is displaced axially through the medium of a control unit 60, so as to obtain said specific distance, as will be described in more detail below with ref- erence to fig. 5, The deflection point 6 is comprised of a fixed, smooth axle part 6a, which prefer-ably includes edge flanges 6b, 6c.

Alternatively, the deflection point 6 (see fig. 4) may consist of a cylindrical or at least partially cylindrical centre part 6a', that includes two rounded flanged edges 6b', 6c'.

The unit 5 comprises rollers that have soft peripheral surfaces and that guide the position of two chain sections, wherein a chain section 4b, connecting

upstream with the chain section 4a, is adapted to pass between said rollers.

An adapted extension of the chain section 4a is obtained through the me- dium of a circuit 63, which regulates the speed at which the bobbin 3 rotates.

As shown in fig. 4, the bobbin 3 is fastened to a shaft 52, driven by a mo- tor 51, wherewith the motor 51 and the shaft 52 can be moved to and fro by a screw-associated arrangement 54, through the medium of a guide system 53.

The control unit 60 co-acts with the measuring device 7 and the arrange- ment 54 is actuated by an output circuit 62, via a comparison circuit 61 b, with said value stored in the circuit 61 a.

The control unit 60 also co-acts with a further measuring device 8 and the drive motor 51 is actuated via a comparison circuit 64b, with the value stored in the circuit 64a.

The control of axial displacement of the bobbin 3 in relation to prevailing winding turns, significant to the present invention, is shown in more detail in figs. 6 and 7.

The invention is based on an arrangement for displacing a bobbin 3 axially when winding a chain 4, consisting of a series of flat links, onto the chassis-carried bobbin 3.

The bobbin 3 is caused to move axially to and fro during a chain-winding process, so that the chain links will be wound tightly together in related winding turns, designated x, y, z...... n-1, n, between mutually opposite end-walls 3a, 3b of the bobbin in a first layer 48 (x-n), a second layer 49 orientated over the first layer and including the turns (2x-2n), third and further layers, wherein a chain sec- tion 4a, located close to the bobbin and fed thereinto, is arranged to pass a chain- section guiding unit 5, which serves as a fixed point 5', and wherein the chain sec- tion is caused to pass between the unit 5 and the bobbin 3 via a deflection point 6.

The section 4a'close to the bobbin (and also the chain section 4a") is ar- ranged to extend parallel with an inwardly facing surface 3b'of a first end-wall part 3b during a major part of a first winding turn, wherewith the bobbin 3 is caused to move in a first direction"F1"through a distance corresponding to the width of the chain during the remaining part of said first winding turn (x).

The bobbin 3 is caused to move in a second direction"F2", during an adapted part of a second winding turn (y) adjacent the first turn (x).

Displacement of the bobbin in said second direction"F2"is adapted so

that the chain section 4a (divided into sections 4a"and 4a') close to the bobbin will define an acute angle (v) with said surface 3b'or plane.

The acute angle (v) shall be adapted to deviate from and decrease a right angle by an extent corresponding to the chain width from a chosen reference point 5'externally of the bobbin.

This reference point 5'is situated at a distance ("A") from the rotational axis 3'of the bobbin 3 corresponding to 2.0 to 4.0 times a bobbin-associated ra- dius"R".

A length-measuring device 7 is adapted to measure the distance (c) be- tween a chassis-associated fixed point and the chain section (4a' ; 4a") situated close to the bobbin.

From a second winding turn (y) or a third winding turn (z), the length-mea- suring device 7 is adapted to cause the bobbin 3 to be moved axially via a control unit 60, when the distance measured deviates from a predetermined value, so that the predetermined distance (c) is obtained.

As a last winding turn (n) is reached in a layer 48 adjacent an opposite end-wall part 3a, the bobbin is displaced in a first direction"F1"through a distance corresponding to the chain width during the remaining part of said last winding turn (n).

With respect to the first winding turn 2x of an overlying second layer 49 adjacent the end-wall part 3a, the chain section 4a", situated close to the bobbin, is caused to extend parallel to an inwardly facing surface 3a'of said end-wall part 3a during a major part of a first winding turn 2x, and the bobbin 3 is caused to move in a second direction"F2"through a distance corresponding to the chain width during the remaining part of said first winding turn 2x.

The bobbin 3 is caused to be displaced in a first direction"F1"during an adapted part of a second winding turn adjacent said first winding turn 2x.

Displacement in said first direction"F1"is adapted so that the chain sec- tion 4a"close to the bobbin will define an acute angle (v') with said surface 3a'.

This acute angle (v') may be adapted to deviate from a right angle by one chain width from a chosen reference point 5'externally of the bobbin.

In this case, the reference point 5'may also be situated from the rotational axis of the bobbin by a distance corresponding to 2.0 to 4.0 times a bobbin-asso- ciated radius"R".

A length-measuring device 7 is also adapted to measure a distance (c') between a chassis-associated fixed point and said chain section situated close to said bobbin also in this case, although this distance will deviate from the distance "c"for the first winding turn.

From a second or a third winding turn 2y, 2z, the length-measuring device 7 is adapted to allow the bobbin 3 to be displaced axially in the event that a meas- ured distance deviates from a predetermined value (c'), so that the predetermined distance will be achieved.

At a last winding turn, within a second layer 49 adjacent an end-wall part 3b, the bobbin is caused to move in a second direction"F2"through a distance corresponding to the width of the chain during the remaining part of the last wind- ing turn (2n).

The control unit 60 is thus adapted to control axial movement of the bob- bin 3 in accordance with information stored in the memory and/or in response to control circuits, the situation of a first bobbin-associated end-position 65a, a sec- ond bobbin-associated end-position 65b, the current chain width 65c, the instant rotational positions 65d of the bobbin, the length of the bobbin between mutually opposite surface parts of the end-walls 65e, the speed at which the bobbin rotates 65f and/or the distance measuring device 65g.

The bobbin 3 co-acts with an axle (shaft), which is rotated by a first motor 51, while axial movement of the bobbin is caused or driven by a second motor 54.

The upper curve in the graph, shown in fig. 7, illustrates displacement of the bobbin between said end-wall parts 3a, 3b during the winding process of a layer 48 and is winding-turn related, while the lower curve in said graph illustrates displacement of the bobbin during winding of an overlying layer 49.

It will be particularly apparent from the graph in fig. 7 that the movement pattern of the bobbin adjacent the end-wall parts 3a, 3b is controlled without assis- tance from the length-measuring device 7, whereas winding of the chain there be- tween takes place in a controlled manner via measurement of the distances (c) and (c').

Deflection 6 shall take place as close as possible to the peripheral edge surface 3b"of the end-wall parts 3b, and the device 7 shall be placed as close as possible to the deflection point 6.

The fixed point 5'and the deflection shall keep the chain section 4a'ex-

tended (stretched) beyond the device 7.

It will be understood that the invention is not restricted to the afore de- scribed and illustrated exemplifying embodiment thereof and the modifications can be made within the scope of the inventive concept as illustrated in the accompany- ing claims.