EP3880028A1

EP3880028A1 - Apparatus for attaching an object to a support and method for operating an apparatus for attaching an object to a support

Info

Publication number: EP3880028A1
Application number: EP19805221.9A
Authority: EP
Inventors: Markus Wetzel; Ulrich Greis
Original assignee: YKK Stocko Fasteners GmbH
Current assignee: YKK Stocko Fasteners GmbH
Priority date: 2018-11-13
Filing date: 2019-11-13
Publication date: 2021-09-22
Anticipated expiration: 2039-11-13
Also published as: DE102018008941A1; EP3880028B1; PL3880028T3; WO2020099499A1

Abstract

The invention relates to an apparatus for attaching an object (30, 32) to a support (34), said apparatus comprising: a main body (10), upper and lower dies (12, 14) adapted to deform said object (32, 34), at least one of said dies being movable relative to said main body to approach the other die, a force limiting means (36) adapted to limit the force (F2) applied for moving said movable die to a predetermined value, and measuring means (16, 20; 18, 22) adapted to measure the position of the movable die relative to said main body and/or relative to said other die. According to the invention, a monitoring means (24) is adapted to receive an output signal of said measuring means (16, 20; 18, 22) and to perform at least one of the following: a) permanently monitoring the position of said movable die (12, 14) relative to said main body (10) and/or to said other die, during a process of attaching said object (32, 34) to said support (34), b) storing said monitored position in at least one predetermined moment during the attaching process, c) determining in at least one predetermined moment during the attaching process whether the distance between said upper and lower dies (12, 14) is below a lower limit, and d) determining in at least one predetermined moment during the attaching process whether the distance between said upper and lower dies (12, 14) is beyond an upper limit. Moreover, the invention refers to a method for attaching an object to a support.

Description

APPARATUS FOR ATTACHING AN OBJECT TO A SUPPORT AND METHOD FOR OPERATING AN APPARATUS FOR ATTACHING AN OBJECT TO A SUPPORT

The invention relates to an apparatus for attaching an object to a support, said apparatus comprising a main body, upper and lower dies adapted to deform said object, at least one of said dies being movable relative to said main body to approach the other die, a force limiting means adapted to limit the force applied for moving said movable die to a predetermined value, and measuring means adapted to measure the position of the movable die relative to said main body and/or relative to said other die. Said object may be one single part or may be formed from two or more parts.

An apparatus as detailed above is known from WO 98/02055 A1. In said known apparatus, a contact switch is closed when the lower die is moved upward beyond a pre determined limit because this is understood as resulting from a failure in the attaching process. When the contact switch is closed, the apparatus is automatically stopped and a warning signal is issued. Instead of said contact switch, a measuring sensor or a proximity switch can be used, which might be helpful for calibrating purposes.

It is an object of the invention to enhance the above known attaching apparatus. The above object is achieved by a monitoring means, adapted to receive an output signal of said measuring means and to perform at least one of the following: a) permanently monitoring the position of said movable die relative to said main body and/or to said other die, during a process of attaching said object to said support, b) storing said monitored position in at least one predetermined moment during the attaching process, c) determining in at least one predetermined moment during the attaching process whether the distance between said upper and lower dies is below a lower limit, and d) determining in at least one predetermined moment during the attaching process whether the distance between said upper and lower dies is beyond an upper limit.

Regarding the object to be attached to said support, the invention particularly relates to rivets and buttons. Regarding the support to which the object is to be attached, the invention particularly relates to textiles and leather.

According to the invention, the result of the measuring performed by the measuring means is used not only for detecting malfunctions and for calibrating, but for the purpose of detailed monitoring of the attaching process. Thereby, it is, e.g., possible to rec ord the attaching process by continuously monitoring the position of the movable die and storing the monitored position with view to predetermined moments. Respective protocols can be very helpful for operators, particularly with view to the fact that respective posi tions might (gradually) change when a high number of objects is attached in series.

Moreover, said monitoring can be used to judge whether or not the attaching process is performed without failure. This might refer not only to a lower limit with a view to the distance between the upper and lower dies, but also to an upper limit. If said distance is below the lower limit, e.g. one of the parts of a rivet might be missing. If the distance is beyond the upper limit, one of said parts of the rivets might be not in the correct position. If the judgment of the apparatus is that the distance between the dies at a predetermined moment is outside of the predetermined limits the apparatus may warn the operator by emitting for example a light or a sound or may cause the apparatus to cease to function once dies are in a position which enables the object and the support to be removed.

According to a preferred embodiment of the invention, the measuring means comprises at least one proximity sensor. This is a very reasonable way to realize the measuring means because such a proximity sensor can be operated to permanently output the result of the detected distance. Preferably, the proximity sensor is held stationary relative to said main body. Thereby, it is not necessary to couple moving parts to cables, wires or the like. Rather, the proximity sensor may be adapted to detect or measure the distance to a position indi cator (in the following referred to simply as“indicator”), whose movement is synchronized with one of the upper and lower dies. The indicator can be realised in any suitable form, including a blade and a rod.

According to a further preferred embodiment of the invention, a preferred predetermined moment is the moment in which the distance between said upper and lower dies is minimized or in which the attaching process is terminated. To this end,“terminated” means that the process has come to an end, i.e. the upper and lower dies have returned to their initial positions before the process started, regardless of whether the object was successfully attached or a failure occurred. By performing the above monitoring, particularly the storing and/or the determining in said moment, the operator may obtain most helpful information about the performance of the apparatus.

A moment may be any period of time limited only by the length of time needed to move the upper and lower dies through the cycle which starts from the point in time where they are furthest apart, continues to the point at which they are at their closest and finishes when they return to the initial position where they are furthest apart.

According to the invention, said upper limit and/or said lower limit for the distance between said upper and lower dies is preferably adjustable, particularly dependent on the thickness of said support and/or dependent on the type of the object. Thereby, it is possi ble to adapt the apparatus to changing circumstances in a very simple way, e.g. with view to varying thicknesses of the support. The same applies to varying types and/or sizes of the object to be attached to the support.

According to a further preferred embodiment of the invention, the apparatus is programmable to deal with different thicknesses of said support and/or with different objects in a predetermined order. Thereby, the apparatus can be operated as a sequencer and it is possible to deal with said different thicknesses and/or with said different objects without any changeovers or re-adjustments, e.g. calibrations performed by an operator.

In addition to the above apparatus, the invention also refers to a method for oper ating an apparatus for attaching an object to a support, comprising the steps of moving at least one of said upper and lower dies to approach the other die, so that the object is de formed by a force limited to a predetermined value, wherein the position of the movable die relative to said main body and/or to said other die is measured, characterized by mon itoring the attaching process, said monitoring including at least one of the following: a) permanently monitoring the position of said movable die relative to said main body and/or to said other die, b) storing said monitored position in at least one predetermined moment during the attaching process, c) determining in at least one predetermined moment during the attaching process whether the distance between said upper and lower dies is below a lower limit, and

d) determining in at least one predetermined moment during the attaching process whether the distance between said upper and lower dies is beyond an upper limit.

Preferably, one predetermined moment is the moment in which the distance be tween said upper and lower dies is minimized or in which the attaching process is termi nated.

It is further preferred that said upper limit and/or said lower limit for the distance between said upper and lower dies is adjustable, particularly dependent on the thickness of said support and/or dependent on the type of the object.

Finally, it is preferred to include the step of programming said apparatus for dealing with different thicknesses of said support in a predetermined order and/or different objects, which objects are to be attached in a predetermined order.

In the following, the invention is explained in detail using preferred exemplary embodiments with reference made to be attached drawings with further details. In the draw ings:

Fig. 1 is a schematic view of the attaching portion of an attaching apparatus according to a preferred embodiment of the invention,

Fig. 2a and 2b show details of the apparatus of Fig. 1 , in a larger scale,

Fig. 3 is a schematic view of the apparatus during a cycle with 2 parts of an object to be attached, Fig 4 is the same view as Fig. 3, but at a different point in the cycle with the object already attached,

Fig. 5 is a schematic view of a force limiting means for a preferred embod iment of the attaching apparatus according to the invention,

Fig. 6 schematically shows 2 objects attached to a support in regions with different thicknesses,

Fig. 7 is a diagram of the positions of upper and lower dies of a preferred embodiment of the attaching apparatus according to the invention during an attaching process,

Fig. 8 is a diagram of the relation between a setting pitch SP and a support thickness (fabric thickness) FT,

Fig. 9 schematically shows relative positions of first and second sensors and first and second movable parts at different times,

Fig. 10 is a diagram of distances over time, and

Fig.11a and 11b show a side view and a front view, respectively, of an embodiment of the attaching apparatus according to the invention.

Fig.1 shows an example of an attaching portion 100 of an apparatus according to the invention. Fig.11 a) shows a side view of an embodiment of an attaching apparatus 300 comprising the attaching portion 100 according to invention and Fig. 11 b) a front view of the apparatus.

The attaching apparatus which attaches objects comprised of upper part 30 and lower part 32 to support 34 as shown in Fig. 3, comprises a stationary main body 10 which comprises the attaching portion 100 for attaching objects to the support 34, and a supply portion 200 for supplying objects 30, 32 to the attaching portion 100.

According to this embodiment, the object is a button, and the upper part 30 is provided with an engaging portion 31 , to enable it to engage with an engaging member not illustrated, and the lower part 32 is provided with a plurality of engagement daws 32B for attaching to the upper portion thought the support 34.

The supply portion 200 is provided with a first hopper 40 for supplying upper parts 30 to attaching portion 100, and a second hopper 41 for supplying alternative lower parts 32 (not shown) to the attaching portion 100. Moreover, the supply portion 200 provides chutes 42, 43 which connect from each hopper 40, 41 respectively to a parts feed 44. It will be appreciated that in apparatuses of greater complexity, more hoppers and chutes may be provided.

According to Fig.11 , the first hopper 40 is connected to the upper side of the at taching portion 100 through one of the chutes 42 and an upper side of the parts feed 44, and the second hopper 41 is connected to a lower side of attaching portion 100 through another chute 43 and a lower side of the parts feed 44.

When a plurality of upper parts 30 is provided in the first hopper 40, the upper parts 30 become aligned in the first hopper 40 which is caused to rotate by a power source (not shown) connected thereto in order that the upper parts 30 are supplied to chute 42 such that the position of each upper part 30 enables them to pass consistently along the chute 42 so as to arrive in the attaching portion 100 ready to be attached to the lower part 32.

The upper parts 30 supplied by chute 42 are carried to the upper side of the feed 44 wherein the upper parts 30 are carried to the upper side of the attaching portion 100 by a feeding means such as a pressure means which moves in a forward and backward direction between the attaching portion 100 and the end of chute 42 in order to propel the feed 44 to the attaching portion 100 whilst maintaining their position.

This description also applies to the movement of the lower parts 32 from the second hopper 41 to the attaching portion 100, the lower parts 32 supplied by chute 43 are carried to the lower side of the feed 44 wherein the lower parts 32 are carried to the lower side of the attaching portion 100 by a feeding means propelled by for example a pressure means which moves in a forward and backward direction between the attaching portion 100 and the end of chute 43 in order to propel lower part 32 to the attaching portion 100 whilst maintaining their position. A person skilled in the art will appreciate that this invention is not limited by this delivery mechanism and alternative methods for supplying upper and lower parts 30, 32 to the attaching portion may be substituted for the mechanism described herein.

The attaching apparatus shown in Fig. 1 which is a cross-sectional view taken along the line A-A of Fig. 11 (a) comprises the stationary main body 10, an upper die 12 and a lower die 14, said upper and lower dies 12, 14 both being movable relative to main body 10. The upper and lower dies 12, 14 are connected to a driving source (not shown) with a force limiting means, described in greater detail below. The upper and lower dies 12, 14 move in a vertical direction towards and away from each other in order to attach upper parts 30 and lower parts 32.

Moreover, the apparatus further comprises upper and lower sensors 16, 18, which are held stationary relative to main body 10. The upper and lower sensors 16,18 are proximity sensors measuring the respective distance to upper and lower indicators 20, 22 which are integrally fixed on the attaching portion 100 in the region of the upper die and the lower die, respectively.

In particular, the indicators 20, 22 protrude in the plane of the figure away from the dies in a direction perpendicular to the movement of the dies 12, 14, wherebetween the upper and lower sensors 16, 18 are attached to the main body 10. To this end, upper indicator 20 is synchronized to upper die 12, so that the movement thereof is synchro nized with the movement of upper die 12. Similarly, the movement of lower indicator 22 is synchronized with the movement of lower die 14. On other hand, the upper and lower sensors 16, 18 are attached to the stationary main body10 and thus, do not move independently. Thus, upper and lower sensors 16, 18 respectively sense the positions of upper and lower dies 12, 14 relative to main body 10 and, thereby relative to one another.

It will be appreciated that as long as an indicator moves in a synchronized manner with the die to which it is attached, the position of its cooperating sensor on the apparatus is limited only by the range of the sensor.

Sensors 16, 18 and indicators 20, 22 together make up measuring means for measuring the position of (movable) lower die 14 to upper die 12.

Furthermore, the technical effect obtained through this invention would also be obtained if an indicator was stationary and its cooperating sensor moved in a synchro- nized manner because it was attached to a die which moved towards and away from the indicator.

Thus for each die, either an indicator has synchronized movement with that die towards and away from a stationary sensor or a sensor has synchronized movement with a die towards and away from a stationary indicator.

It will be appreciated that the phrase‘towards and away from’ may include tangen tial movement.

The output signals of upper and lower sensors 16, 18 are received by a processor 24. Processor 24 is used as a monitoring means adapted to permanently monitor the position of (movable) upper and lower dies 12, 14, to store said monitored position and/or to judge whether a distance between upper and lower dies 12, 14 is below a lower limit and/or beyond an upper limit. Processor 24 is coupled to a storage 26 and a display 28. Fig. 2a), shows upper indicator 20 in two positions relative to upper sensor 16. The position shown in dashed lines is the position before attaching an object to a support (starting position). Commonly this is also the time in the cycle when an upper part 30 is moved by the feed 44 into the attaching apparatus 100. The position shown in solid lines of the upper sensor 16 is the position obtained when the upper and lower dies have moved closest to each other and the object is attached to the support.

The position of the upper indicator 20 changes with the movement of upper die 12 between the two positions as the cycle of the attaching process progresses.

The latter position (shown in solid lines) is obtained when there is a distance zlG1 between upper sensor 16 and upper indicator 20.

Fig. 2b) is similar to Fig. 2a), but shows lower sensor 18 and lower indicator 22 (shown in solid lines), with the distance AG2 between lower sensor 18 and lower indicator 22 obtained when the lower indicator and the lower sensor are at their closest position after attaching the object to the support. The position of the lower indicator 22 shown in dashed lines, is obtained when the lower die 14 with a lower part 32 is moved by the feed 44 to the attaching apparatus 100. In general, the positon of lower indicator 22 changes with the movement of lower die 14 between the two positions as the cycle of the attaching process progresses. Fig. 3 shows upper die 12 holding upper pari 30 of an object to be attached and lower die 14 holding a lower part 32 of said object. For the rest of this description the object will be assumed to be a button, but buttons of other types together with rivets, eyelets or other items could also be used.

Fig. 4 shows upper part and lower part 30, 32 deformed and attached to the support 34 following the respective movement of the upper and lower dies 12, 14.

The support 34 is omitted in the Fig.3, but prior to the attachment of the object it is disposed between the upper die 12 and the lower die 14 in a manner which allows the result shown in Fig.4 where the upper and lower parts have been brought into attaching contact with the support 34 being held therebetween.

The support may be a fabric which may be woven, knit or non-woven. It may be also be synthetic leather.

The upper part 30 and the lower part 32 may be the female part of a snap button which can be made from a metal material such as aluminum alloy or copper alloy. The lower part 32 which is fixed from a lower surface of support 34 comprises an annular ring- shaped portion 32A and a plurality of engagement prongs 32B which integrally protrude away from the surface of the annular ring-shaped portion 32A perpendicularly to a diame ter of the annular ring-shaped portion 32 A.

The engagement prongs 32B are arranged to extend parallel to the axis passing through the centre of the lower part 32 at regular intervals to each other. The distal end of each engagement prong 32 B comprises a sharpened point to enable the prong to pene trate the support.

Referring to Fig 3, the upper part 30 which is fixed to an upper surface of the support 34 comprises a female member 30A which can engage with a male member of a male snap button (not shown), and a flange 30B extending annularly from the female member 30A.

The flange 30 B extends outward from the centre of the female member 30A; up ward from the lowest extremity of the female member 30A and curves back on itself to provide an annular recessed portion 30C. The annular recessed portion 30C comprises an opening 30D into which the engagement prongs 32B of the lower part 32 are com pelled by the movement of the upper and lower dies 12, 14. Thus when the engagement prongs 32 B come into resistant contact with the internal surface of the annular recessed portion 30C they are plastically deformed and follow the inner curve of the annular recessed portion 30C. Thus when the engagement claws 32 B of the lower part 32 are urged into the opening 30D after penetrating from the lower side of the support 34 above the upper side of the support 34, the lower part 32 becomes fixed to the upper part 30 by plastic deformation of the engagement prongs 32 B within the annular recessed portion 30C.

Male parts of snap buttons can carry out engagement and disengagement with respective female parts of snap buttons. That is to say, the shape of a female member 30A comprises engaging portion 31 which is encircled by an elastically deformable flange, whilst the shape of a cooperating male member (not shown) comprises an en gagement projection.

Thus, the support 34 within the attaching portion 100 can receive the attachment of the parts 30 32 through the operation of the upper and lower die 12, 14.

The upper die 12 moves reciprocately in a vertical direction powered by a driving source, (not shown), through a force limiting means, which is described in greater detail below.

In the embodiment, the distal end of the upper die 12 comprises an engagement member 12C which conforms to the shape of a male part of a snap button intend to engage with the female member 30A enabling upper parts 30 provided with female member 30A to engage with upper die 12, That it say, upper part 30 snap engages with engage ment member 12C when the upper die 12 receives upper part 30 from the upper side of the feed 44.

The holding means used to hold the upper part 30 and the upper die 12 together may be configured in other variations. For instance, if the upper parts are intended to be used in the formation of a male button part or a rivet instead of for a female button part, the distal end of the upper die 12 may be shaped in order to corresponding engage with the shape of the male button part or the rivet. In the position of the parts and dies shown in Fig 3, the feed 44 has already supplied to the upper die body 12B an upper part 30 This exemplar supplying method will be easily appreciated by considering that described in WO2018/069980

Various configurations are also conceivable for the lower die 14. In the embodiment, the lower die comprises a pin 14A, which is inserted in the hole circumscribed by the annular ring-shaped portion 32A of the lower part 32, and a pushing portion 14B, that abuts the outer circumference of the pin 14A and by contacting the annular ring-shaped portion 32A pushes the lower part 32 toward the upper die 12.

Circumscribing the lower die 14 is a seat part 15, onto which can be placed the supporting means 34, and within which there is a cylindrical portion 17, which comprises a hole through which the cylindrical lower die 14 can reciprocately rise and fall.

The seat part 15 and the cylindrical portion 17 are stationarily fixed to main body 10, the lower die 14 reciprocates in a vertical direction within the seat part 15 and along the cylindrical portion 17 by means of a driving source (not shown) through the force limiting means, which is described in greater detail below.

Between the pin 14A and the pushing portion 14B is a spring, with the aid of which the pin 14A can move in upper and lower directions in relation to pushing portion 14B. Although not illustrated, it will be appreciated that the pin 14A enters the hole circumscribed by the annular ring-shaped part 32A just before the upper and lower part 30, 32 make contact with supporting means 34 which becomes clamped between the distal end of the descended upper die 12 and the distal end of the raised lower die 14 within the annular ring-shaped portion 32A of the lower part 32.

At this point in the cycle, contact pressure is applied to supporting means 34 be tween the pin 14A of the lower die 14 and the upper die 12 by compression in the spring. Then the pushing portion 14B is compelled upward and the upper part 30 is attached to the lower part 32 as the engagement prongs 32B penetrate the supporting means 34 and are deformed outwardly due to contact with the inner side of the annular recessed portion 30C. The pin 14A also acts to correct the posture of the engagement prongs 32 B when the angle between a radius from the centre of the hole circumscribed by the annular ring- shaped portion 32A and an engagement prong is an acute angle, returning the angle to a right angle and ensuring that the engagement prong 32 B is perpendicular to the plane of the annular ring-shaped portion 32A as well as clamping the fabric 34 and setting the lower parts 32.

The position shown in Fig. 3 corresponds to the position shown in Fig. 2 when the indicators 20, 22 are dashed.

The positions of upper and lower dies 12, 14 shown in Fig. 4 correspond to the position shown in solid lines in Fig. 2 when the indicators 20, 22 are not dashed.

As disclosed by the drawings, the distance moved by the indicator 20 integrally connected with the upper die 12 corresponds to the distance moved by the distal end of the upper die 12. On other hand, the distance moved by the indicator 22 integrally connected with the lower die 14 corresponds with distance moved by the distal end of the lower die 14. That is to say the measurement of the distance moved by the respective dies makes no reference to the deformity of the elastic member. The object comprising upper part 30 and lower part 32 may be a rivet. Support 34 may be knitting tape, woven fabric, leathered tape, a textile tape.

Fig. 5 shows a compensator, i.e. a force limiting means adapted to limit the force applied for moving lower die 14 upwardly. The compensator comprises a compensator spring 36. When the assembling process is performed, a driving source (not shown) ex erts a driving force F1 in the direction of the arrow on the left hand side of the compensator shown in Fig. 5. This results in a rotation in the counter-clockwise direction as depicted by respective arrows in Fig. 5. Said rotation, in turn, results in that attaching force F2 is exerted to move lower die 14 in the direction depicted by the respective arrow in Fig. 5. Thus, lower die 14 is moved upwardly by driving force F1 , limited by compensator spring 36 to attaching force F2. In other words, using compensator spring 36 in the attaching apparatus according to the invention results in that attaching force F2 is limited to a pre determined value, even if driving force F1 exceeds said predetermined value.

Advantageously, driving force F1 will always be higher than said predetermined value, so that attaching force F2 is constant, at least after a respective compression of compensator spring 36.

Fig. 6 shows support 34 having a first region 34.1 of shallower thickness and a second region 34.2 of deeper thickness. Due to the compensator with compensator spring 36, the action of cutting into the threads of the support because of overpressure particularly in region 34.2 as well as loose attachment because of low force particularly in region 34.1 can be prevented, so that it is possible to deal with supports comprising regions of different thicknesses.

The diagram of Fig. 7 shows an example of the positions and, thereby, the movements of upper and lower dies 12, 14 over the time during an attaching cycle. According to said diagram, upper die 12 is initially moved downward, then upward, back into the initial position. Lower die 16 is moved upward in a first part and then downward in a second part. At L upper and lower dies 12, 14 have minimum distance D1 to one another. At t₂, i.e. when lower die 14 is in the uppermost position, distance D2 between upper and lower dies 12, 14 is greater than distance D1.

That is to say, the phase of the cycle at is the positon D1 with the shortest distance between the distal end of the upper die 12 and the distal end of the lower die 14 and so indicates the thickness of the deformed part of the object to which is attached the support 34.

What is to be taken from the above is that the apparatus described above is adapted to permanently monitor the position of lower (movable) die 14 relative to main body 10 and to upper die 12 during the complete process of attaching parts 30, 32 to support 34. This corresponds to lit. a) in claims 1 and 7. The monitoring is not limited by any variation in movement of the dies.

In Figs. 3 and 4, the maximum thickness of the attached part is the distance measured from the lower surface of the annular ring-shaped part 32A of the lower part 32 to the upper extent of the upper surface of the flange 30B of the upper part 30 in the ver tical direction.

That is to say, the maximum height of the attached button is the distance meas ured from the upper surface of the distal end of the pushing portion 14B to the lower surface of the distal end of the upper die 12 when the support 34 is under maximum compression.

With the embodiment of the attaching apparatus according to the invention shown in Fig. 1 , diagrams according to Fig. 7 can be stored as model diagrams and/or as results of respective measurements performed by upper and lower sensors 16, 18, and can be displayed in display 28. Said model diagrams can be used as a basis for the operation of the apparatus according to a respective program stored in storage 26 and controlled by processor 24. The diagrams resulting from respective measurings performed by upper and lower sensors 16, 18 can be displayed by display 28, particularly continuously and/or together with the model diagrams so that an operator can survey the whole process.

Respective diagrams are not limited to the diagrams shown in Fig. 7 and referring to only a single support thickness and to a single type of object to be attached to the support. Rather, in preferred embodiments of the invention, sequences and/or combinations of respective diagrams can be modelled and used to attach a sequence of objects of dif ferent types to a support and/or to attach objects to a support with regions of different thicknesses.

Thus, the described apparatus is adapted to store monitored positions during the attaching process, corresponding to lit. b) in claims 1 and 7.

Particularly, to deal with different support thicknesses, the apparatus according to the invention may be programmable by storing relations between the support thickness on the one hand and the attaching height SP (setting pitch) on the other hand, which attaching height is essentially the distance between the upper and lower dies 12, 14 in the moment in which the attaching process is completed. A respective example is shown in Fig. 8. According to Fig. 8, there is a linear relation between the upper and lower limits U, L for the setting pitch SP on the one hand and the support thickness (fabric thickness) FT on the other. If after the completion of an attaching cycle, the setting pitch SP of the at tached object is below the lower limit L, a failure occurred such as the omission of one of upper and lower parts 30, 32. If the upper limit U is exceeded, a failure occurred such as insufficient deformation of upper part 30 and/or lower part 32.

What is to be taken from the above is that the apparatus described above is adapted to judge during the attaching process whether or not a distance between upper and lower dies 12, 14 is below a lower limit and/or beyond an upper limit, corresponding to lits. c) and d) in claims 1 and 7. The information gathered about SP and FT as shown in Fig. 8, may be retained in the storage 26 for each type of attaching button and attaching rivet and can be used in respective operating programs stored in storage 26 and controlled by processor 24.

For instance, an operator prepares and inputs to the storage the information based on the dimensions of deformed parts. Thereafter, the operator may input infor mation regarding the parts to be attached by using an input device (not shown). As a result, the region, enclosed by L and U, within which the thickness of an attached button can be judged to be non-defective product, is set.

In the described apparatus, lower and upper limits L and U are adjustable, particularly dependent on the thickness of support 34. They may also be adjustable dependent on the type of object 30, 32.

The apparatus described above is programmable for dealing with, e.g. a support having a first thickness in a first region and a second thickness in a second region. In this case, the apparatus is programmed to base the attaching process on a first set of lower and upper limits L and U for dealing with the first region and on the basis of a second set of lower and upper limits L' and U’ for dealing with the second region. Thus, the apparatus can perform the attaching of objects in said two regions in a single sequence of cycles, said cycles being based on different pairs of values L and U.

However, the apparatus can also deal with different objects in a sequence. Like in the case of different thicknesses of the support, the above-described apparatus can be programmed to use suitable (different) pairs of values L and U according to the sequence of different objects to be attached. The apparatus is capable of dealing with a variety of objects and a variety of regions within the same sequence and to handle a series of sequences.

When a part is attached to a support using this apparatus, distance between the upper die 12 and the lower die 14 (D_x) at time (t_x) is measured in real time, so if meas urement D1 is not included in the region enclosed by L and U, it is possible to stop the operation of the machine or inform the operator whereupon the operator can check for a defective product immediately. Fig. 9 schematically shows relative positions of upper and lower sensors 16 and 18 and upper and lower indicators 20 and 22. To this end, Fig. 9a) shows the initial positions before assembling, whereas Fig. 9b) shows the position of said elements at ti (Fig. 7), i.e. in the moment in which distance D between upper and lower dies 12, 14 is minimum, i.e. D = D1.

In Fig. 9 A1 and A2 are the detection ranges of upper and lower sensors 16, 18, with A1 = A2 = 0 to 4 mm. B1 is the initial distance between upper sensor 16 and upper movable part 20. B2 is the initial distance between lower sensor 18 and lower movable part 22. The initial distance is the distance before the attaching process starts by respectively moving upper and lower dies 12, 14.

C1 is the distance between upper sensor 16 and upper indicator 20 in the moment in which upper indicator 20 is in the lowermost position. C2 is the distance between lower sensor 18 and lower indicator 22 when lower indicator 22 is in the uppermost position.

The attaching process may be explained by using the following exemplary numerical values below.

In the above-described embodiment, B1 = 58 mm, B2 = 21 mm, C1 = 2 mm, C2 = 1.5 mm.

Setting pitch SP corresponds to G (Fig. 4) with G = D1 or G = D1 + E. E is an off set with E = -1.5 mm and may or may not apply.

Fig. 10 shows distance D = C1 + C2 during the assembling process. According to Fig. 7, minimum distance D1 occurs not at the end, but before lower die 14 reaches its uppermost position. According to Fig. 10, minimum distance D1 occurs after lower die 14 has left its uppermost position. Best results are achieved when distance D1 occurs at the moment in which lower die 14 is in its uppermost position.

The features of the invention disclosed in the above description, claims and drawings may be useful to the realization of the various embodiments of the invention either by themselves or in any combination. For instance, the object may at least partly be made from material other than metal, such as resin.

For instance, the apparatus of the present invention may be obtained if the upper die is fixed to the main body and does not move in the upper and lower direction and, the lower die moves in the upper and lower direction with respect to the main body. Con versely, the apparatus of the present invention may be obtained if the lower die is fixed to the main body and does not move in the upper and lower direction and, the upper die can move in the upper and lower direction with respect to the main body.

Claims

1. Apparatus for attaching an object (30, 32) to a support (34), said apparatus comprising:

a main body (10),

upper and lower dies (12, 14) adapted to deform said object, at least one of said dies being movable relative to said main body to approach the other die,

a force limiting means (36) adapted to limit the force (F2) applied for moving said movable die to a predetermined value, and

a measuring means (16, 20; 18, 22) adapted to measure the position of said movable die relative to said main body and/or relative to said other die,

characterized by

a monitoring means (24) adapted to receive an output signal of said measuring means (16, 20; 18, 22) and to perform at least one of the following:

a) permanently monitoring the position of said movable die (12, 14) relative to said main body (10) and/or to said other die, during a process of attaching said object (30, 32) to said support (34),

b) storing said monitored position in at least one predetermined moment during the attaching process,

c) determining in at least one predetermined moment during the attaching process whether the distance (zlG1 + Z\G2) between said upper and lower dies (12, 14) is below a lower limit, and

d) determining in at least one predetermined moment during the attaching process whether the distance (4G1 + AG2) between said upper and lower dies (12, 14) is beyond an upper limit.

2. Apparatus according to claim 1 , characterized in that said measuring means (16, 20; 18, 22) comprises at least one proximity sensor (16, 18).

3. Apparatus according to claim 2, characterized in that said proximity sensor (16, 18) is held stationary relative to said main body (10).

4. Apparatus according to any preceding claim, characterized in that said predetermined moment is the moment in which the distance (21G1 + AG2) between said upper and lower dies (12, 14) is minimized or in which the attaching process is terminated.

5. Apparatus according to any preceding claim, characterized in that said upper limit and/or said lower limit for the distance (DQ1 + AG2) between said upper and lower dies (12, 14) is adjustable, particularly dependent on the thickness of said support (34) and/or dependent on the type of the object (30, 32).

6. Apparatus according to any preceding claim, characterized in that it is programmable to deal with different thicknesses of said support (34) and/or different objects (30, 32) in a predetermined order.

7. A method for attaching an object (30, 32) to a support (34) using an apparatus comprising a main body (10) and upper and lower dies (12, 14), particularly using the apparatus according to any preceding claim, said method comprising the steps of:

moving at least one of said upper and lower dies to approach the other die, so that the object is deformed by a force (F2) limited to a predetermined value, wherein

the position of the movable die (12 or 14) relative to said main body and/or to said other die is measured,

characterized by

monitoring the attaching process, said monitoring including at least one of the following:

a) permanently monitoring the position of said movable die (12, 14) relative to said main body (10) and/or to said other die,

c) determining in at least one predetermined moment during the attaching process whether the distance (zlG1 + DQ2) between said upper and lower dies (12, 14) is below a lower limit, and

d) determining in at least one predetermined moment during the attaching process whether the distance (7K31 + DQ2) between said upper and lower dies (12, 14) is beyond an upper limit.

8. A method according to claim 7, characterized in that said predetermined moment is the moment in which the distance (DQ1 + AG2) between said upper and lower dies (12, 14) is minimized or in which the attaching process is terminated.

9. The method according to claim 7 or 8, characterized in that said upper limit and/or said lower limit for the distance (DQ1 + DQ2) between said upper and lower dies (12, 14) is adjustable, particularly dependent on the thickness of said support (34) and/or depend ent on the type of the object (30, 32).

10. The method according to any of claims 7 to 9, characterized by the step of pro gramming said apparatus for dealing with different thicknesses of said support (34) and/or different objects (30, 32) in a predetermined order.