WO2009091299A1

WO2009091299A1 - Coupling

Info

Publication number: WO2009091299A1
Application number: PCT/SE2008/000722
Authority: WO
Inventors: Karl-Otto Strömberg
Original assignee: Flexprop Ab
Priority date: 2008-01-17
Filing date: 2008-12-18
Publication date: 2009-07-23
Also published as: SE0800110L; SE531909C2

Abstract

A coupling for fixedly securing a tube has a first (1) and a second (2) part, which each have at least one first set of clamping surfaces (8) for cooperation with the tube, as well as clamping devices for fixedly clamping the clamping surfaces to the tube. The clamping surfaces (8) are edge surfaces on planar, flat-shaped outer material pieces (5, 22), as well as further planar, flat-shaped inner material pieces (9), the material pieces being joined together on the one hand by the intermediary of a glue union, and on the hand by the intermediary of projections or pins fitting in recesses or apertures. A method of producing the coupling comprises the steps that, starting from planar, sheet-shaped material, planar material pieces included in the coupling are cut out, of which material pieces certain are provided with recesses, whose edge surfaces are formed to clamping surfaces, and certain are provided with mutually fitting projections or pins and recesses or apertures, respectively, the geometric configuration of the coupling being established by fitting of the projections or the pins in corresponding recesses or apertures, and the coupling being finally joined together by gluing.

Description

COUPLING

TECHNICAL FIELD

The present invention relates to a coupling for securing at least one tube or one profile and comprises a first and a second part, which each display at least a first set of clamping surfaces for cooperation with the tube or the profile, as well as clamping devices for fixedly clamping the clamping surfaces against the tube or the profile.

The present invention also relates to a method of producing a coupling for securing at least one tube or one profile.

BACKGROUND ART

Within many sectors of industry, and as typical example mention might be made of the automotive industry, there is often a need to be able to accurately position a workpiece in relation to a reference point or another workpiece.

In such instance, holders are often used on which grippers are mounted for cooperation with the individual workpiece. These holders are often called manipulators.

A distinction is often made between geometrically controlling manipulators and non- geometrically controlling manipulators. As regards the requirements on precision, these are of a highly stringent nature concerning geometrically controlling manipulators and may amount to one or a few tenths of a millimetre, while a greater degree of inaccuracy as regards non-geometrically controlling manipulators may be permitted.

In, for example, a press line for producing motor body parts, a planar sheet blank is fed by means of some form of feeder which is provided with manipulator and gripper which feeds in the sheets into the first press included in the press line. When this has carried out its working stroke, the partly processes workpiece is removed by a second feeder, which may be a specifically designed feeder or a generally usable industrial robot. This feeder or robot is also provided with a manipulator with grippers which transfer the workpiece from the first to the second press included in the press line. If the press tool in the second press is provided with means for accurately guiding the partly processed workpiece to the correct processing position, the manipulator on the feeder or robot may be of the non- geometrically controlling design. If, however, there are no such guide means in the press tool in the second press, the feeder or robot and the associated manipulator must position in an extremely accurate manner the workpiece in the press tool in the second press.

Another situation where similar requirements are placed is a workstation where, for example, a plurality of body parts is assembled by welding procedures. In such instance, there may be a stationary holder in which the different workpieces are placed. Such a stationary holder may also be called a platform. For feeding the different workpieces to the stationary platform, universally applicable robots may be used which, in such instance, are provided with manipulators and grippers or end effectors.

Primarily as regards non-geometrically controlling manipulators, these are often constructed as a framework system composed of aluminium tubes. For joining together these aluminium tubes, use is generally made of couplings which are often of the same material.

Manipulators produced in this manner are relatively light in weight (compared with steel constructions) but often suffer from excessive fragility so that considerable flexion may occur under load. In a rapidly operating feeder or robot, this is not acceptable, since such flexion involves a risk of oscillation phenomena which jeopardise the accurate positioning of the workpiece.

It is also known in the art to produce from tube or profile material holders of the type under consideration here where the tube or profile material consists of composite material, preferably carbon fibre composite. Such a material possesses considerably greater rigidity than aluminium and also a density which is considerably lower, approximately half. If such material is employed, it is naturally most expedient if the couplings that are employed for interconnecting the manipulator also possess corresponding qualities.

PROBLEM STRUCTURE

The present invention has for its object to design the coupling intimated by way of introduction so that it will be of extremely light weight, high precision as a result of the absence of clearance or play, as well as extremely high mechanical strength, principally rigidity. Further, the present invention has for it object to design the coupling intimated by way of introduction so that it may be opened, for example for adjustment or reuse, and that it may be produced at reasonable cost.

Regarding the method, the present invention has for its object to formulate the method so as to attain the corresponding objects.

SOLUTION

The objects forming the basis of the present invention will be attained regarding the coupling, if the coupling is characterised in that the clamping surfaces are edge surfaces on substantially planar, flat-shaped material pieces, that the first and the second part include substantially planar, flat-shaped material pieces, and that the material pieces are interconnected to one another, on the one hand by the intermediary of glue union, and on the other hand by the intermediary of mechanical coupling devices.

Regarding the method, the objects of the present invention will be attained if the method is characterised in that, starting from planar, sheet-shaped material, planar material pieces included in the coupling are cut out, that certain material pieces are provided with recesses whose edge surfaces are formed into clamping surfaces for cooperation with the tube or profile, that at least certain of the material pieces are provided with mutually fitting projections or pins and recesses or apertures, respectively, that the geometric configuration of the coupling is established by fitting of the projections or the pins into corresponding recesses or apertures, and that couplings are finally joined together by gluing.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will now be described in greater detail hereinbelow, with reference to the accompanying Drawings, hi the accompanying Drawings:

Fig. 1 is a perspective view of a first embodiment of the coupling according to the present invention;

Fig. 2 is an exploded view of the coupling of Fig. 1 ;

Fig. 3 is an exploded view of a second part of the coupling of Fig. 1, together with a detail magnification;

Fig. 4 is a perspective view of a second embodiment of the coupling according to the present invention;

Fig. 5 is a perspective view of a second part included in the coupling of Fig. 4, together with a detail magnification;

Fig. 6 shows the second part according to Fig. 5 in exploded view and detail magnification;

Fig. 7 is a perspective view of a first part included in the coupling of Fig. 4, together with a detail magnification;

Fig. 8 is a perspective view of a third embodiment of the coupling according to the present invention; and

Fig. 9 is an exploded view of the coupling according to Fig. 8. DESCRIPTION OF PREFERRED EMBODIMENT

The fundamental principle lying behind the coupling according to the present invention is that it is composed of a number of planar material pieces which are cut out from a sheet-shaped material, consisting of a composite, preferably a carbon fibre composite. The cutting-out of the material pieces included in the coupling may be put into effect in any optional manner, but, according to the present invention, water cutting has proved to give extremely good accuracy.

For joining together the material pieces included in the coupling, the coupling is provided with mechanical coupling devices which, in one preferred embodiment, consist of projections or pins fitting in recesses or apertures. These mechanical coupling devices are designed so as to define together the geometric configuration of the coupling and to make possible an assembly of the coupling to a coherent unit which withstands handling without "falling apart". For the final union of the material pieces included in the coupling, a glue union is employed.

In addition to the above-mentioned recesses or apertures, and projections and pins, respectively, screw unions, rivet unions or combinations of such types of unions may be employed.

The coupling illustrated in Fig. 1 has a first part 1 and a second part 2 which are compressible against one another by means of clamping devices in the form of screws 3. The coupling is formed so as to cooperate with a tube or a profile, as a rule a circular- cylindrical tube of carbon fibre composite, and to be secured on some type of holder, which may be a manipulator or part thereof.

The first and second parts are composed of a number of planar material pieces consisting of a carbon fibre composite, which is a material displaying low density and an extremely high level of mechanical strength, above all rigidity. The first part 1 and the second part 2 together define a through-going accommodation space which has a longitudinal centre line 4 and which is intended for accommodating the tube or the profile.

It will be apparent from Fig. 1 that both the first part 1 and the second part 2 are formed as box structures which each comprise four peripheral material pieces 5 and 6. These peripheral material pieces form a rectangular or square frame, where the sides are parallel with a common line. Transversely directed in relation to this line, possibly at right angles in relation thereto, the first part 1 and the second part 2 have transverse material pieces 7.

Two opposing material pieces 5 each in the first and second parts display recesses, whose edge surfaces 8 form clamping surfaces for cooperation with the tube or the profile in the accommodation space.

Interiorly in the coupling, there are provided additional material pieces 9 with clamping surfaces 8, which are preferably parallel with the peripheral material pieces 5.

It will be clearly apparent from Fig. 2 that the material pieces 5 and 9 provided with clamping surfaces 8 in the first part 1 of the coupling display projections or pins 10 which, on assembling of the first part 1 , are intended to be accommodated in apertures 11 and recesses 12 in the peripheral material pieces 6.

Correspondingly, the peripheral material pieces 6 display pins 13 which are intended to be accommodated in corresponding recesses 14 in the transverse material piece 7.

It will further be apparent from Fig. 2 that the transverse material piece 7 in the first part 1 has elongate apertures through which extend upper portions or projections 15 on the material pieces 5 and 9 provided with clamping surfaces.

It will further be apparent from Fig. 2 that the second part 2 of the coupling, which is shown undermost in Fig. 2, is constructed and composed in fundamentally the same manner as the first part 1. However, there are certain differences in detail. The counterparts to the projections 15 on the first part are, in the second part 2, planar on the underside, since the lower side of the transverse material piece 6 in the Figure must be able to abut against a planar surface, possibly the plate 16 illustrated in Fig. 2. Further, the projections 10 and recesses 12 have changed place in the second part compared with the first.

A further difference in detail is that the inner material pieces 9 provided with clamping surfaces 8 display pins 17 which are accommodated in corresponding apertures 18 in the transverse part 7 instead of the elongate projections 15 in the first part (see Fig. 3).

It will further be apparent from Fig. 2 that the inner material pieces 9 provided with clamping surfaces 8 are disposed on both the first and the second part. In the longitudinal direction of the line 4, these material pieces are placed so that they are located very proximal one another when the first and second parts are assembled together so that a guiding along the line 4 may thereby be realised.

It will also be apparent from Fig. 2 that there are provided columns 19 in the corners of the coupling, which may be provided with threaded or through-going openings for screws, for example the screws 3. The columns 19 display such cross section that they extend out into the corner regions of both the first and the second part in order to guide these parts in relation to one another.

It will be apparent from Fig. 1 that the first and the second parts 1 and 2, respectively abut against one another with mutually facing surfaces on the peripheral material pieces 5 and 6. In this position, the clamping surfaces 8 are formed in such a manner that the cross sectional configuration of the through-going aperture which extends through the coupling is identical with the outer contour of the tube or the profile with which the coupling is intended to cooperate. In that the clamping force of the screws 3 is at least partly taken up by the peripheral material pieces, a profile or a tube placed in the accommodation space would probably be insufficiently fixed in place. In order to remedy this shortcoming, there is disposed, between the clamping surfaces 8 and the tube or the profile, a somewhat resiliency yieldable material, possibly elastic, which realises the requisite clamping force even though the first and the second parts are drawn into tight abutment with one another.

As was intimated by way of introduction, the coupling according to the present invention has, in addition to the mechanical coupling devices, which thus include projections or pins fitted into corresponding recesses or apertures, a final union consisting of a glue union. These glue unions may be achieved either simultaneously with the "assembly" of the material pieces included in the coupling, or subsequently.

Fig. 4 is a perspective view of a second embodiment of the coupling according to the present invention. This embodiment is intended to interconnect two mutually intersecting tubes or profiles which lie in different planes in relation to one another. However, like the embodiment according to Fig. 1 , it may be secured on a manipulator. This implies that the coupling has accommodation spaces with longitudinal axes 20 and 21, which intersect one another and which lie in separate planes. Possibly, the angle between the longitudinal axes 20 and 21 may be a right angle.

The coupling according to Figs. 4 to 7 has uppermost a first part 1, centrally a second part 2 and lowermost a new first part 1. Both of the first parts 1 are identical to that described with reference to Figs. 2 and 3 and will not, therefore, be described further here.

Analogous with that disclosed above, the entire coupling is joined together in the same manner as that described in the foregoing, hence on the one hand by glue union and on the other hand by mutually fitting pins or projections, and apertures or recesses, respectively.

In the second part 2 of the coupling according to Figs. 4 to 7, all peripheral material pieces 22 have been provided with clamping surfaces 8. It will be apparent from Fig. 6 that two of these material pieces have the clamping surfaces turned to face upwards (in the Figures), while two have their clamping surfaces 8 turned to face downwards. The material pieces 22 are pairwise alike as regards the projections and recesses which are used for interconnecting the material pieces.

hi the same manner as that described above, there are disposed inner material pieces 23 between the peripheral material pieces 22 and these are also provided with clamping surfaces 8. In the illustrated embodiment, there are disposed, on the upper side of the transverse material piece 24, two inner material pieces provided with clamping surfaces 8 and on the underside an additional two, these material pieces 23 being pairwise turned at right angles in relation to one another. It will further be apparent from Fig. 6 that the inner material pieces 23 are interconnected with the transverse material piece 24, by the intermediary of pins 17 and corresponding apertures 18.

It will be apparent from Fig. 5 that the second part 2 has counterparts to the above- described columns 19 which are provided with waists (not shown on the Drawings) which extend through recesses 25 shown in Fig. 6 in the transverse material piece 24. The columns 19 are, in the manner described above, fixedly glued in the final phase in the peripheral material pieces 22 and the transverse material piece 24.

Figs. 8 and 9 show a third embodiment of the coupling according to the present invention. Also in this embodiment, the coupling has a first part 1 and a second part 2, between which there are defined, on the one hand a through-going accommodation space with a centre line 30 and, on the other hand an accommodation space closed at its one end and displaying a centre line 31. The coupling according to Figs. 8 and 9 may therefore be characterised as a T- coupling. Both the first part 1 and the second part 2 display elongate, peripheral material pieces 26 each with a clamping surface 8. Further, the coupling displays in its one short end peripheral material pieces 27, each with a clamping surface 8. Finally, both the first and the second parts have, in relation to the peripheral material pieces 27, two opposing peripheral material pieces 28 which lack clamping surfaces. Both the first and the second parts 1 and 2, respectively, have transverse material pieces 7 which, in the embodiment under consideration here, are rectangular rather than square.

Interiorly in the coupling, there are inner material pieces disposed interiorly at the through- going accommodation space with centre line 30 and provided with clamping surfaces, these material pieces corresponding to the material pieces 9 according to Fig. 1. Correspondingly, the accommodation space is defined with the centre line 31 and clamping surfaces 8 disposed on inner material pieces 32 which are parallel with the peripheral material pieces 27.

Also in complete analogy with that described above, the coupling according to Figs. 8 and 9 displays columns 19, of which at least some are disposed at the corner regions of the coupling for supporting them. The columns 19 have threaded or through-going bores for screws.

That which was disclosed above concerning the joining together of the above material pieces included in the coupling also applies in its entirety in complete analogy to this embodiment.

Claims

WHAT IS CLAIMED IS:

1. A coupling for securing at least one tube or one profile, comprising a first (1) and a second (2) part, which each display at least a first set of clamping surfaces (8) for cooperation with the tube or the profile, as well as clamping devices (3, 19) for fixedly clamping the clamping surfaces against the tube or the profile, characterised in that the clamping surfaces (8) are edge surfaces on substantially planar, flat-shaped material pieces (5, 22, 26, 27); that the first and the second part include further substantially planar, flat-shaped material pieces (9, 18, 23, 32); and that the material pieces are interconnected to one another, on the one hand by the intermediary of glue union, and on the other hand by the intermediary of mechanical coupling devices.

2. The coupling as claimed in Claim 1, characterised in that the mechanical coupling devices comprise projections or pins (10, 13, 15, 17) fitting in corresponding recesses or apertures (11, 12, 14, 18).

3. The coupling as claimed in Claim 1 or 2, characterised in that at least either of the first (1) and the second (2) parts has a second set of clamping surfaces (8).

4. The coupling as claimed in any of Claims 1 to 3, characterised in that the first (1) and the second (2) parts include peripheral material pieces (5, 6, 22, 26 27) which are substantially parallel to a common line, and at least one transverse material piece (7, 24) which is transversely directed, preferably at right angles, to said line.

5. The coupling as claimed in Claim 4, characterised in that two opposing peripheral material pieces (5, 26) each have at least one clamping surface (8).

6. The coupling as claimed in Claim 4, characterised in that two pairs of opposing material pieces (22) each have at least one clamping surface (8).

7. The coupling as claimed in Claim 4, characterised in that only one of two opposing material pieces (27) has a clamping surface (8).

8. The coupling as claimed in Claim 6 or 7, characterised in that, substantially parallel with the material pieces (5, 22, 26, 27) provided with clamping surfaces (8), there are inner material pieces (9, 23, 32) which are provided with clamping surfaces (8).

9. The coupling as claimed in any of Claims 4 to 8, characterised in that the clamping devices comprise screw unions (3) with nuts (19) which are secured at least in the transverse material piece (7, 24).

10. The coupling as claimed in any of Claims 1 to 9, characterised in that, when a first (1) and a second (2) part are tensioned into abutment against one another, the clamping surfaces (8) define an aperture whose configuration is identical to the outer contour of the tube or the profile; and that, between the outer contour of the tube or the profile and the clamping surfaces, there is disposed a somewhat resilient material.

11. The coupling as claimed in Claim 10, characterised in that the clamping surfaces (8) are semi-circular.

12. The coupling as claimed in any of Claims 1 to 11 , characterised in that the material pieces (5, 6, 7, 22, 26, 27, 29) are produced from plates of a composite material, preferably a carbon fibre composite material.

13. A method of producing a coupling for fixedly securing at least one tube or one profile, characterised in that, starting from planar, sheet-shaped material, planar material pieces included in the coupling are cut out; that certain material pieces are provided with recesses whose edge surfaces are formed to clamping surfaces for cooperation with the tube or the profile; that at least certain of the material pieces are provided with mutually fitting projections or pins and recesses or apertures, respectively; that the geometric configuration of the coupling is established by fitting of the projections or the pins in corresponding recesses or apertures; and that the coupling is finally joined together by gluing.

14. The method as claimed in Claim 13, characterised in that the clamping surfaces (8) are arranged along a straight line (4).

15. The method as claimed in Claim 13, characterised in that the clamping surfaces (8) are arranged along two mutually intersecting, straight lines (20, 21 ) in two separate planes.

16. The method as claimed in Claim 13, characterised in that the clamping surfaces (8) are arranged along two mutually intersecting, straight lines (30, 31) in a common plane.