Framework comprising separably connected profile bars

In a framework made of separably connected profile bars, some of the bars have longitudinal slots and others have hollow sections for engagement of a coupling member in their face ends. The coupling member consists of a bearing housing with an upwardly oriented wedge surface and a holding member with a matching inclined surface which is forced against the wedge surface by a spring force. The holding member can be moved in a longitudinal direction by an eccentric pin arranged transversely to the profile bar and located with its actuating end in a cross hole of the profile bar so that a coupling hook at the end of the holding member is movable both longitudinally relative to stationary projections of the bearing housing as well as laterally due to the rising movement of the matching inclined surface along the wedge surface. In order to obtain a reliable and easy-to-handle coupling member including the smallest possible number of detail parts, a resilient tongue is cut out from a sheet metal strip forming the holding member and bent so that an end of the tongue bears against an inner wall of the bearing housing and slides in a longitudinal guide. The wedge surface extends between the two coupling projections, and an offset of the holding member engages behind the wedge surface, locating the eccentric pin in a rear wall cut-out of the bearing housing. In addition, the resilient tongue enables the eccentric pin to be pressed in, similar to a pushbutton, so that in the initial position the actuating end of the pin is engaged in a cross hole of the profile bar.

BACKGROUND AND SUMMARY OF THE PRESENT INVENTION 
The present invention relates to a framework comprising separably connected 
profile bars. The connection is achieved by a coupling member consisting 
of a bearing housing and a holding member incorporated therein in a 
longitudinally movable manner. The coupling member is inserted into a 
hollow section of a first profile bar so that stationary coupling 
projections at an end of the bearing housing protrude from a face end of 
the bar. A free end of the holding member is provided with a coupling hook 
which is arranged between the two coupling projections of the bearing 
housing and also protrudes from the face end of the first profile bar. The 
pair of coupling projections and the coupling hook thus provide a coupling 
arrangement which can be inserted in an undercut longitudinal slot of 
another profile bar, e.g., a vertical column, and locked in position 
therein. 
This locking in position is accomplished through an eccentric pin which 
extends transversely to the first profile bar, is rotatably supported in 
the bearing housing and passes through the holding member. An actuating 
end of the eccentric pin fits a cross hole of the profile bar which 
accepts the coupling member. During rotation of the eccentric pin, the 
eccentric of the eccentric pin moves the holding member in the 
longitudinal direction of the profile bar so that the coupling hook is 
also moved in the same direction. The coupling hook simultaneously 
performs a movement transverse to the profile bar, which movement is 
accomplished due to the fact that the bearing housing is provided with an 
inwardly and upwardly extending wedge surface and that the holding member 
has a matching inclined surface which is pressed against the wedge surface 
by a spring force. 
The coupling member of the framework according to the present invention, 
firstly, is of special design since the coupling arrangements in their 
initial condition ready for coupling are situated in a common plane, i.e., 
the movable coupling hook lies between the two coupling projections. 
Therefore, the longitudinal slot of the profile bar, into which the 
coupling arrangements are to be engaged, need not be of a greater width 
than that required for accepting only one coupling arrangement, for 
example, the stationary coupling projections. In addition to the small 
opening width of the slot, a closed installation space of the coupling 
arrangements is achieved. Also, the two stationary coupling projections 
ensure a clearly defined location of the profile bar equipped with the 
coupling member during and after the coupling operation. 
The design of the coupling member according to the present invention has 
the additional special feature that the coupling hook not only performs a 
transverse motion toward the coupling projections but simultaneously, 
because of the employed control arrangement, a longitudinal motion. 
Because of these simultaneously affected two motion components, a 
particularly safe and strong connection is obtained between the two 
profile bars. The transversely directed motion component first causes a 
locking in position of the two coupling arrangements at the opposing inner 
surfaces of the slot opening. This locking in occurs because the coupling 
hook moving in a transverse direction approaches one inner surface, while 
the two coupling projections will eventually rest against the opposite 
inner surface. During this transverse motion, the coupling hook leaves the 
common plane extending between the coupling projections and moves behind 
the adjacent wall of the longitudinal slot. Because of the simultaneously 
effected motion component directed longitudinally, the coupling hook moves 
against the inner surface of the longitudinal slot wall, bearing against 
the wall and thereby firmly pressing one profile bar against the face of 
the other profile bar which carries the coupling member. In this manner, 
one profile bar is pushed against the other. 
In the case of known frames using coupling members in accordance with 
German utility model No. 73 71 203.0, the coupling member consists of 
numerous detail parts thereby making the manufacture per unit more 
expensive and requiring a laborious and time-consuming assembly of the 
coupling member at the profile bar. The holding member consists of a plate 
which, with its sloping shoulders, is forced against wedges of the bearing 
housing by a spring resting against an eccentric pin. Special locating 
devices, such as a circlip and an annular shoulder at the pin shaft, are 
required to secure the eccentric pin in the bearing housing. This locating 
in position makes the assembly of the components within the hollow section 
of the profile bar accepting the coupling member extremely difficult. 
Locating the pin relative to the bearing housing, however, is essential 
because the spring has the tendency to force the pin out of a cross hole 
in the profile bar. Moreover, it is nearly impossible to remove an 
installed coupling member in order to replace, for example, a broken 
spring without damaging the member. 
The present invention has as an object to develop a framework for rapid and 
easy assembly of the initially mentioned type, whose coupling member 
consists of the most simple and easy-to-assemble and disassemble 
components for convenient installation in the profile bar and removal from 
the same as required. 
This object and others are achieved by the present invention with a 
coupling member consisting of only three components, i.e., a bearing 
housing, a holding member specially formed from a sheet metal strip, and 
an eccentric pin. A resilient tongue cut out of the sheet metal strip of 
the holding member performs two different spring functions. One function 
is to keep the matching inclined surface of the holding member in contact 
with a wedge surface of the bearing housing. The other spring function is 
to load the eccentric pin like a pushbutton so that, by exerting an axial 
pressure, the pin can be pressed into the bearing housing until it comes 
out of the cross hole in the profile bar. This arrangement enables 
convenient installation and removal of the coupling member into and out of 
the profile bar. 
According to the present invention the coupling member is an assembly which 
can be prefabricated from the above-mentioned three components for 
insertion into any profile bar provided with a cross hole. For insertion, 
all that has to be done is to press in the eccentric pin at its actuating 
end in an axial direction as described above. As soon as the coupling 
member has reached its specified location in the hollow section of the 
profile bar, the actuating end will automatically engage into the cross 
hole of the profile bar. This engagement accurately determines the 
location of the coupling member in the profile bar, especially if the 
mentioned stationary coupling projections at the bearing housing are 
provided with locating shoulders which will be arranged in front of the 
face of the profile bar. No additional locking elements are required to 
secure the coupling member in the profile bar. 
According to another special aspect of the present invention, the 
controlling eccentric disk of the pin is located at the side of the 
holding member opposite the resilient tongue and acts as a stop which, 
with its outer face, bears against the inner side wall of the bearing 
housing. This defines the initial position of the "pushbutton" formed by 
the eccentric pin in the unpressed condition. The actuating end of the 
eccentric pin protrudes correspondingly from the bearing housing and 
enters the cross hole of the profile bar to the desired extent. When 
pressing in this "pushbutton", the control end of the holding member is 
caught by the eccentric disk thus deforming the resilient tongue. 
The small number of components for the coupling member, and its securing in 
position in the profile bar, are possible because the holding member in 
accordance with the present invention simultaneously performs several 
functions. Firstly, of course, the front end coupling hook and the rear 
end control required for acting on the eccentric pin are formed from a 
sheet metal strip. The control may be one-sided projections, e.g., bent 
edge strips forming rails on one surface of the holding member against 
which the eccentric disk is arranged to effect the desired inward or 
outward thrust of the holding member during the rotational actuation of 
the eccentric pin. The second function of the holding member in accordance 
with the invention consists of the previously mentioned double spring 
function of the cut out resilient tongue, which is utilized for both 
maintaining contact between the holding member, the bearing housing and 
the pushbutton effect of the eccentric pin. A third function of the 
holding member is securing the eccentric pin in its installed end position 
in the bearing housing. 
This last mentioned function is achieved in the following manner. In order 
to enable convenient assembly, when the holding member in accordance with 
the invention together with the eccentric pin is inserted into the bearing 
housing, a rear portion of the bearing housing is provided with a wall 
cut-out. Without the solution in accordance with the present invention, 
there is a risk that the eccentric pin may fall out of the wall cut-out 
unless additional locating means are provided. The invention overcomes 
this problem simply with a control arrangement which keeps the eccentric 
pin in a surrounding grip and, similar to an anchor, engages behind the 
wedge surface with the matching inclined surface produced by bending the 
sheet metal strip. This engagement is reliably secured through the 
above-mentioned spring action of the resilient tongue formed in the sheet 
metal strip. In this way, the resilient tongue performs a third function, 
i.e., the location of the eccentric pin in its installed position in the 
wall cut-out. 
The space between the two coupling projections of the bearing housing is 
preferably utilized for the wedge surface, which provides, in particular, 
the following advantages. Firstly, the wedge surface is brought very far 
to the front and commences before the face of the profile bar so that in a 
coupling situation, the wedge surface also engages the slot opening. The 
connection between the two coupling projections causes a reinforcement of 
the mutual position of the two coupling projections. The portion of the 
holding member at this far advanced wedge surface is very short and 
therefore relatively stiff although a resilient sheet metal strip is used 
for forming the holding member. Finally, the advanced wedge surface 
enables an accumulation of material in this area of the bearing housing, 
which material produces a side wall against the outside, because reference 
surfaces are preferably provided at the inside of the side walls, which 
serve as guides for the holding member during assembly and disassembly. In 
the present case the reference surface can be integral with the material 
accumulation. Another reference surface of this kind can be provided in 
the bearing area of the eccentric pin. 
In order to positively prevent the "pushbutton function" of the eccentric 
pin from occurring in the coupling position, it is preferable to provide 
stops in the bearing housing, which protrude as locking features into the 
path of the movable parts only in the coupling position. The stops, i.e., 
in the removal position, are arranged outside of this path. 
To ensure satisfactory distribution of the spring functions provided by the 
resilient tongue, it is preferred to arrange the tongue in the central 
section of the sheet metal strip so that the spring force is acting 
equally on the front coupling hook and the rear control arrangement of the 
holding member so as to develop the mentioned spring functions. 
For securing the holding member, it is preferred that the coupling hook 
contacts the inner surface of the slot wall engaged behind in two points 
only. This contact can be achieved by simply arranging the edge of the 
coupling hook to be of curved shape. 
Further advantages and measures of the invention will become evident from 
the claims, the drawings and the following description which explains in 
detail a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
For connecting profile bars 10, 11, i.e., an elongated bar having a 
predetermined exterior contour, coupling members 20 are used which are 
housed in a hollow space 12 of the hollow section bar 10 from whose face 
13 coupling arrangements 21, 22 are projecting. In a coupling situation 
shown in FIGS. 2 and 4, the coupling arrangements 21, 22 engage undercut 
longitudinal slots 14 of the profile bar 11. In the illustrated example, 
the profile bar 11 is a vertical, octagonal column with eight longitudinal 
slots 14 around its circumference. 
The coupling member 20 is a prefabricated assembly consisting of three 
components, i.e., a bearing housing 23, a sheet metal strip 24 serving as 
a holding member, and an eccentric pin 25. These components will be 
described in greater detail below. 
The bearing housing 23 is of rectangular shape and has a cross section 
adapted to match the hollow section or space 12 of the profile bar 10. The 
bearing housing has the shape of a rectangular tube which, with the 
exception of the profiles indicated in the following, is open from the 
front to the rear face, so that the housing 23 actually consists of side 
walls only. One side wall 26 (located at the front in FIG. 8) is provided 
at the inner end of bearing housing 23 with a wall cut-out 27 having steps 
28 which are chamfered towards the inside and serve as access opening for 
installing the sheet metal strip 24 equipped with the eccentric pin 25. 
The wall cut-out 27 blends into a circular bearing area 29 for a 
correspondingly dimensioned actuating end 30 of the eccentric pin 25. 
A rear side wall 31 of the housing 23, which is visible through the wall 
cut-out 27 of FIG. 8, is provided with an opening 32, coaxial with the 
circular arc of the front bearing area 29, for a journal 33 of the 
eccentric pin 25 which journal 33, in the installation condition, however, 
protrudes into only approximately one half of the opening 32 with its face 
end 34, as is shown in FIGS. 3 and 4. This partial protrusion into the 
opening 32 (as is evident from the plan view of the bearing housing 23 in 
FIG. 9) is offset and normally supports the journal 33 only in the left 
side of the opening 32 shown in FIG. 9. At the opposite side, in front of 
the opening 32, a pointed strip 35 extending longitudinally is arranged at 
the rear wall 31. The pointed strip 35 contacts the circumference of the 
journal 33 with its inner end 36. For insertion, the journal 33 of the 
eccentric pin 25 mounted on the sheet metal strip 24 is provided with a 
diagonally extending assembly groove 37 (FIG. 10). The groove 37 defines 
an aligned rotational position of eccentric pin 25 when the pin 25 is 
inserted from the side of the mentioned pointed end along the strip 35 
into the wall cut-out 27. 
The bearing housing 23 is a zinc die-casting and, to provide access to the 
parts in the casting, has a front window 38 (FIG. 8), an upper window 39 
(FIG. 9), and a rear window 40 (FIG. 5). The windows are arranged in 
various longitudinal sections of bearing housing 23. The windows are, of 
course, also used to observe the installation procedure and the end 
position of the sheet metal strip 24 equipped with the eccentric pin 25. 
The windows enable the special profiles of the two inner surfaces of the 
front and rear walls 26, 31, which profiles are shown by broken lines in 
FIG. 9. 
The rear side wall 31 is provided in the area of the previously mentioned 
inner portion of opening 32 with a thicker section 41, in front of which 
an inclined surface 42 significant for disassembly purposes is arranged. 
The thicker section 41 eventually blends into a flat inner wall 43. Beyond 
the front window 38, the opposite inner surface of the front side wall 26 
has a rising ramp 44, starting from the window 38 which, in the front area 
of the bearing housing 23, generates a thicker wall section 45. The wall 
thickness is initially constant for a short length and eventually declines 
as a steep wedge surface 46 towards the front of the housing 23. As can be 
seen from FIGS. 8 and 9, a tip 47 of the wedge surface 46 is slightly 
protruding beyond the front face end 48 of the bearing housing 23. 
Beyond the face end 48, a pair of stationary coupling projections 21 
protrude and form one of the above-mentioned coupling arrangements of the 
coupling member 20. The coupling projections 21 are formed as an extension 
of the upper and lower side walls of the bearing housing 23. The 
projections 21 are approximately arrow-shaped and project beyond the upper 
and lower side wall with a shoulder 49 (FIG. 8) which, (as shown in FIG. 
2) in the installation condition, is placed in front of the face 13 in the 
tube profile of the profile bar 10. Due to this stop effect, the depth of 
insertion of the coupling member 20 into the hollow space 12 of the 
profile bar 10 is defined. In the plan view of FIG. 9 the projections 21 
have a rising slope 50 to facilitate the insertion of the coupling 
arrangements into the longitudinal slot 14 of the other profile bar 11. 
Because the wedge surface 46 extends beyond the housing end 48, the two 
coupling projections 21 are connected to each other via a continuous 
wedge-shaped web 51 (FIG. 8). 
The sheet metal strip 24 has the special shape shown in FIGS. 6 and 7. At 
its front end, the strip 24 is provided with a rearwardly bent hook 22 
with a curved edge 58 so that a movable coupling arrangement is provided 
in the coupling member 20. From the adjacent center section 57 of the 
sheet metal strip 24, a resilient tongue 53 is cut out in a U-shaped cut 
and then bent. Also, in the center section 57, there is a Z-type bend in 
the sheet metal strip 24. The inner end of the sheet metal strip 24 
includes a control section 61 into which a slot 54 is cut, whose edge 
facing the center is bevelled forming a projecting strip 55 on one surface 
side 62 of the strip 24. The end of the sheet metal strip 24 is bevelled 
in the same direction as the strip 55 and forms an end strip 56. The 
surface side 62 provided with the strips 55, 56 lies opposite the surface 
side to which the tongue 53 is bent at an angle. 
In order to facilitate installation, the eccentric pin 25 with the journal 
33 is first inserted into the slot 54 until an eccentric disk 63 of the 
pin 25 with its inner face 64 (FIG. 10) abuts the previously mentioned 
surface side 62 of the sheet metal strip 24 like a stop. In this way, 
diametrically opposed circumferential points of the eccentric disk 63 are 
placed between the two strips 55, 56. The sheet metal strip 24 with the 
eccentric pin 25 is introduced through the already mentioned wall cut-out 
27 of the bearing housing 23. At this time, the mentioned inclined 
surfaces and ramps 44 guide the sheet metal strip 24 through the bearing 
housing 23 along the inner surfaces of the side walls 31, 26. 
In the completely installed condition the components of the coupling member 
20 are in the positions shown in FIGS. 1 and 3 inside. The coupling hook 
22 is then located between the two coupling projections 21 outside of the 
bearing housing 23. The offset 52 engages in front of the wedge tip 47, 
whereby the matching inclined surface 65 of the offset (FIG. 6) is placed 
against the wedge surface 46. The free end of the resilient tongue 53 
bears against the mentioned inner wall 43 of the bearing housing 23. The 
end strip 56 engages behind the eccentric pin 25 at its eccentric disk 63 
and thus secures the eccentric pin 25 in the mentioned bearing area 29 of 
the opening 32. The three components of the coupling member, i.e., the 
bearing housing 23, the sheet metal strip 24, and the eccentric pin 25 
form an assembly without the need for additional securing arrangements. 
The eccentric disk 63 with its outer face 66 (which can also be seen in 
FIG. 10) is kept in contact with the inner surface of the front side wall 
26 in the bearing housing 23 by the end control section 61 of the sheet 
metal strip 24. The force of the resilient tongue 57 causes the actuating 
end 30 of the eccentric pin 25 to protrude laterally beyond the limits of 
the bearing housing 23. 
The assembled coupling member 20 consisting of only three components can be 
sold as a prefabricated construction unit. The construction unit is 
inserted into the hollow space 12 of the profile bar 10 through the 
opening in the face 13. The actuating end 30 of the eccentric pin 25 
protruding from the bearing housing can then be pressed like a pushbutton 
in the direction of arrow 67 shown in FIG. 5. This pressing of the pin 25 
causes an elastic deformation of the resilient tongue 53 and the face end 
34 of the journal 33 enters the empty space 68 of the opening 32, which 
can be seen in FIG. 3. This pushing operation in the direction of the 
arrow 67 moves the entire actuating end 30 below the outer surface of the 
bearing housing 23. Because the bearing housing is then free from the 
interfering actuating end 30, the entire coupling member 20 can be pushed 
into the profile in the direction of arrow 69 until the stop action 
already mentioned in connection with FIG. 2 between the face 13 and the 
rear shoulders 49 of the two coupling projections 21 comes into effect. 
The eccentric pin 25 will then be in axial alignment with a correspondingly 
dimensioned cross hole 70 in one side wall of the profile bar 10. Axial 
pressure along the arrow 67 acting on the eccentric pin 25 is released so 
that actuating end 30 due to slackening of the elastically deformed 
resilient tongue 53 is pushed out again and thus enters the cross hole 70. 
This final condition is shown by the end positions in FIGS. 1 and 3. By 
engagement of the actuating end 30 in the cross hole 70 of the profile bar 
10, the coupling member 20 is secured in the profile bar 10 and cannot 
fall out again. This is only possible by intentionally exerting pressure 
in the direction of arrow 67 and simultaneously pulling out the coupling 
member 20 in the direction of arrow 71 indicated in FIG. 5. The spring 
force of the resilient tongue 53 is thus also utilized to locate the 
coupling member 20 in its end position in the profile bar 10. 
With reference to FIGS. 1 and 3, the coupling hook 22 in a release position 
renders the profile bar 10 ready for coupling so that the coupling member 
20 can be inserted into a selected longitudinal slot 14 of the column 11. 
As can best be seen from FIG. 3, the coupling hook 22 is then in alignment 
with the two coupling projections 21, which alignment is the reason why 
the coupling arrangements 21, 22 have only a profile width 15 which 
corresponds to that of one single coupling arrangement. Consequently, the 
opening width 16 of the longitudinal slot 14 is also of such narrow width 
so that in a coupling situation the aligned coupling arrangements 21, 22 
can be inserted in the other profile bar 11 into the selected slot 14. In 
the inserted condition the face 13 of profile bar 10 abuts an outer 
surface 17 of the slot wall. The eccentric pin 25 is in a rotational 
position (FIG. 1) where the eccentric portion of its eccentric disk 63 
faces the coupling projections 21 (FIG. 3). The stationary coupling 
projections 21 ensure that the profile bar 10, already in the inserted 
condition, assumes an aligned position relative to the profile column 11. 
In order to secure the profile bar 10 in the selected position in the 
profile column 11, the eccentric pin 25 is rotated by a tool which is 
introduced into a profiled location 72 in the face of the actuating end 30 
which is visible in the cross hole 70 of the profile bar 10. When rotated, 
the eccentric disk 63 moves the rear strip 56 of the sheet metal strip 24 
until the end position shown in FIGS. 2 and 4 is reached. This position is 
the coupled, clamping position of the coupling member 20. In this clamping 
position, the eccentric portion of the eccentric pin 25 indicated by a 
marking 19 has moved in front of the end strip 56, while prior to this, in 
the release position of FIG. 1, the eccentric portion was situated at the 
hole end strip 55, i.e., rotated through 180.degree., as shown in FIG. 3. 
As can be seen when comparing FIGS. 1 and 2 the holding member 24 formed by 
the sheet metal strip has moved inwardly by a distance 73 to the clamping 
position. The coupling hook 22 has been pushed inwards correspondingly. 
However, because the mentioned matching inclined surface 65 of the offset 
52 of the holding member 24 is in contact with the wedge surface 46 of the 
bearing housing 23 due to the pressure of the resilient tongue 53, the 
matching inclined surface 65 is simultaneously displaced laterally by the 
wedge surface 46 during the inward motion of the holding member 24 so that 
the coupling hook 22 performs the swivel motion indicated by arrow 74 in 
FIG. 4. This swivel motion moves the edge 58 beyond the slot opening 16 
and in front of the slot inner wall 18 against which the hook 22 is firmly 
pressed during the last phase of the clamping motion of the eccentric 63. 
Due to the curved design of the edge 58 of the hook 22, a two-point 
contact is obtained in accordance with FIG. 7. In the clamping position, 
the stationary coupling projections 21 are firmly pressed against an inner 
surface 75 of the slot opening opposite the hook edge 58 (FIG. 4). The two 
profile bars 10, 11 are now securely coupled to each other. The stationary 
coupling projections 21 do not allow any torsional motion of the profile 
bar 10. 
In the clamping position in accordance with FIGS. 2 and 4, the actuating 
end 30 cannot be pressed in axially against the resilient tongue 53 for 
the purpose of initiating the above described removal of the coupling 
member 20 from the inside of profile bar 10. In this way, disengagement of 
the coupled profile bars 10, 11 cannot be accomplished by an erroneous 
axial pressure acting on the eccentric pin actuating end 30 for removal of 
the coupling member 20. As can best be seen from FIG. 8, the rear side 
wall 31 of the bearing housing 23 carries stops 76 on its inside formed by 
integral blocks which, in the clamping position, move under the rear end 
of the control arrangement or section 61 of the holding member 24. The 
holding member 24 is then locked and cannot be pressed axially inward 
against the force of the resilient tongue 53, as can be seen in FIG. 4. 
If, however, the release position shown in FIGS. 3 and 5 is present, the 
holding member 24 has moved axially outwards until its rear end is 
situated beyond the stops 76 so that an axial pressure along the arrow 67 
can be applied in accordance with FIG. 5. 
The eccentric pin 25 is made from case-hardened steel. When rotating the 
eccentric pin 25 to the clamping position of FIGS. 2 and 4, the bend 60 
(explained in connection with FIG. 6) is permitted to induce a 
longitudinally acting resilience in the holding member 24. When the 
eccentric is rotated, the bend 60 can extend. In this way, the edge 58 of 
the coupling hook 22 remains pressed firmly against the slot inner wall 18 
with a defined holding force. 
In order to separate the two profile bars 10, 11, the eccentric pin 25 is 
rotated again to the release positon of FIGS. 1 and 3. The eccentric disk 
63 then presses against the front strip 55, and the holding member 24 is 
pushed outwardly by the already mentioned distance 73. The matching 
inclined surface 65 slides downwards along the wedge surface 46 under the 
force of the resilient tongue 53, and the coupling hook 22 is swivelled 
back in the direction opposite the arrow 74 of FIG. 4 so that the coupling 
hook 22 reaches alignment again with the two coupling projections 21. The 
edge 58 of the coupling hook 22 has again cleared the slot inner wall 18. 
The coupling arrangements 21, 22 can then be pulled out of the 
longitudinal slot 14 so that the profile bars 10, 11 are separated. 
The principles, preferred embodiment and mode of operation of the present 
invention have been described in the foregoing specification. However, the 
invention which is intended to be protected is not to be construed as 
limited to the particular embodiment disclosed. The embodiment is to be 
regarded as illustrative rather than restrictive. Variations and changes 
may be made by others without departing from the spirit of the present 
invention. Accordingly, it is expressly intended that all such variations 
and changes which fall within the spirit and scope of the present 
invention as defined in claims be embraced thereby.