CONNECTOR
The present invention relates to a connector for de- tachably connecting two structural elements, one of which is engageable with a portion of the connector, while the other has an elongate cavity at an end adapted for the connection.
More precisely, the invention concerns a connector comprising a- first sleeve which has the same cross-sec- tional shape as the cavity and is formed with a longitu¬ dinal bore and a transverse bore; a second sleeve insert- able in the transverse bore of the first sleeve and formed with a bore alignable with the longitudinal bore of the first sleeve, and with a threaded bore extending trans- versely of said alignable bore; an elongate clamping body which is insertable through the longitudinal bore of the first sleeve and the bore aligned therewith in the second sleeve, the outer end of the clamping body being engage¬ able with said one structural element and having an ob- lique surface on the portion received by the second sleeve; and a locking screw rotatable in the threaded bore of the second sleeve for displacement transversely of the clamping body, the point of said locking screw being ap¬ plied against the oblique surface under the action of a spring bias between the first sleeve and the clamping body.
Connectors of this type are widely used for connect¬ ing such structural elements as tubular components, e.g. extruded tubular profiles of aluminium. They are, however, disadvantageous in that they are difficult to assemble, comprise many parts and may unexpectedly come apart during handling.
CH-A-525,346 discloses a connector of the type men¬ tioned by way of introduction, which, however, suffers from the disadvantage that it cannot be mounted as a unit in the structural element at issue. Thus, the assembling becomes complicated and time-consuming.
SE-B-457,454 discloses a similar connector which has the advantage of being insertable as a single unit in the structural element, but which does not afford an ideal transmission of the clamping force from the clamping body to the structural element containing that clamping body. The object of the present invention is therefore to provide a connector of the type mentioned by way of in¬ troduction, which is insertable as a single unit in the structural element and which affords a satisfactory trans- mission of the clamping force between the structural ele¬ ment and the clamping body contained therein, when the connector is tightened. Furthermore, no rotation of the locking screw should be needed for fixing the connector in relation to the structural element. According to the invention, this object is achieved in that the second sleeve is displaceable- transversely of the first sleeve to a position in which it is completely contained in the first sleeve, the clamping body being re¬ ceived in both the first and the second sleeve. When the clamping body and the second sleeve occupy said position, the bore in the second sleeve receiving the clamping body preferably forms a free space on the side of the clamping body opposite to the oblique surface.
Suitably, this is achieved in that the oblique sur- face on the portion of the clamping body received in the second sleeve is arranged in a recess in the clamping body.
The invention will be described in more detail below, reference being had to the accompanying drawings, in which Fig. 1 is a cross-section of two tubular profiles in¬ terconnected by means of the connector according to the invention;
Fig. 2 is a top plan view of a clamping body shown from the side in Fig. 1; Fig. 3 is a front view of a first sleeve shown in longitudinal section in Fig. 1; and
Fig. 4 is a front view of a second sleeve shown in longitudinal section in Fig. 1.
The embodiment shown in Fig. 1 of a connector ac¬ cording to the invention comprises a clamping body 1, a guide sleeve 2, a locking sleeve 3, a locking screw 4 with conical point, and a helical compression spring 5. The connector is mounted inside a square tube 6 which it connects with a tubular profile 7. The connector may, however, be generally used for detachably connecting two structural elements, of which one has an engageable edge, such as the edge 8 of the tubular profile 7, and the other has, at an end adapted for the connection, a cavi¬ ty, such as the cavity 9 of the square tube 6. The guide sleeve 2 has the same cross-section as the cavity 9 of said tube 6 and can thus be inserted therein. Further¬ more, the guide sleeve 2 has a longitudinal bore 10 for receiving the elongate clamping body 1. As is apparent from Fig. 3, the cross-section of the outer portion of the bore 10 is suitably circular. The portion of the lon- gitudinal bore 10 closest to the outer end of the clamp¬ ing body 1 is widened to accommodate the helical spring 5 within a flange 11 on the clamping body 1. The inner por¬ tion of the bore 10 is noncircular, as is also apparent from Fig. 3. The cross-section of the outer portion of the clamping body 1 is circular, while the inner portion of said body is bevelled to have the same noncircular shape as the inner portion of the bore 10.
A recess 12 is arranged in the bevelled inner portion of the clamping body 1, transverse to the longitudinal axis of said body. Furthermore, a conical oblique surface 13 is formed in the bottom of said recess 12.
Moreover, the guide sleeve 2 has a second through bore 14 extending transversely of the longitudinal axis of the bore 10. The bore 14 may have a circular cross- section, but is preferably noncircular, e.g. rectangular, and has the same cross-section along its entire length.
The locking sleeve 3, whose cross-section corre¬ sponds to that of the bore 14, is insertable in said bore 14 of the guide sleeve 2. The locking sleeve 3 has a first through bore 15 which is alignable with the lon- gitudinal bore 10 of the guide sleeve 2 when the locking sleeve 3 is inserted in the bore 14 of the guide sleeve 2. Furthermore, the locking sleeve 3 has a threaded bore 16 directed across the bore 15 and extending from the bore 15 to one end of the locking sleeve 3. It ends in a pin 17 of circular cross-section which thus surrounds the outer opening of the bore 16. In the position shown in Fig. 1, the pin 17 is located in a bore 18 made in a wall of the square tube 6.
When threading the locking screw 4 down into the locking sleeve 3, the point of said screw will be ap¬ plied against the oblique surface 13 since the compres¬ sion spring 5 strives to push the clamping body 1 out of the guide sleeve 2. For the sake of clarity, the point of the locking screw 4 and the oblique surface 13 are shown with different cone angles, but these should, in actual practice, be the same, such that line contact is estab¬ lished.
The recess 12 is defined by a shoulder 19 formed on the inner end of the clamping body 1 at a distance from the oblique surface 13, and the outer end of said clamp¬ ing body 1 is provided with a hook 20. The height of the shoulder 19 is smaller than the distance from the bottom of the recess 12 to that side of the bore 15 in the lock¬ ing sleeve 13 which faces said recess 12, when the lock- ing sleeve 13 occupies the position shown in Fig. 1.
The connector is assembled in the following manner. First, the locking sleeve 3 is inserted in the guide sleeve 2 to the position shown in Fig. 1. At this point, the locking screw 4 has suitably already been threaded into the locking sleeve 3, but its point only slightly projects into the bore 15. Then, the compression spring 5 is mounted on the clamping body 1, and the shoulder end of
said body is inserted in the bore 10 of the guide sleeve 2 to the position shown in Fig. 1, whereupon the locking screw 4 is threaded down to the oblique surface 13 in the recess 12. Thus, the clamping body 1, as well as the lock- ing sleeve 3, is maintained in the guide sleeve 2. Now, the connector is ready to be mounted in, for example, the tube 6. At this point, the end of the guide sleeve 2 fac¬ ing away from the outer end of the clamping body 1 is in¬ serted in the cavity 9 in the square tube 6 until the pin 17 of the locking sleeve 3 is situated at the end of the tube 6. By pressing in the clamping body 1 against the ac¬ tion of the compression spring 5, the locking sleeve 3 will come to occupy a position in the guide sleeve 2 in which it is completely contained therein. Then, the con- nector can be further pushed into the cavity 9 of the tube 6, to the position where the pin 17 is situated directly underneath the opening 18 in one wall of said tube 6. In consequence of the spring bias, the locking sleeve 3 will then be displaced transversely of the longitudinal direc- tion of the guide sleeve 2, such that the pin 17 is re¬ ceived in the opening 18. By that, the connector is fixed in the tube 6.
To connect the tube 6 with the tubular profile 7, the hook 20 on the clamping body 1 is inserted in the tube 7, behind the engageable edges 8, whereupon the locking screw 4 is threaded into the locking sleeve 3. By cooperating with the oblique surface 13, the locking screw 4 will pull the clamping body 1 into the tube 6 against the action of the compression spring 5, until the tubes 6 and 7 are fixedly connected with one another.
To release the tubes 6 and 7 from another, the lock¬ ing screw 4 is loosened, and the compression spring 5 then pushes a portion of the clamping body 1 out of the tube 6, such that the tube 7 can be disengaged from the hook 20. If the locking screw 4 is loosened to such an extent that it loses contact with the oblique surface 13, the shoulder
19 will prevent the clamping body 1 from being pushed out of the tube 6 by the action of the compression spring 5.
The connector may also be removed from the tube 6 as a unit, more precisely by urging the locking sleeve 3, with the locking screw 4 in a suitable position, trans¬ versely of the guide sleeve 2 to a position in which the locking sleeve 3 is completely contained in the guide sleeve 2. Then, the connector may be pulled out of the tube 6 as a unit, there being no risk of the connector coming apart even after it has been pulled out.
The fact that the guide sleeve 3 is displaceable across the guide sleeve 2, the clamping body 1 being re¬ ceived in both sleeves, such that the locking sleeve 3 may be completely contained in the guide sleeve 2, is ad- vantageous not only in that it makes it possible to in¬ sert and remove the connector as a single unit, but also in that a satisfactory transmission of forces from the clamping body 1 to the walls of the opening 18 is obtain¬ ed, without exerting an excessive torque on the guide sleeve 3.
The noncircular shape of the inner portion of the bore 10 facilitates the positioning of the- clamping body 1 when the latter is being inserted in the guide sleeve 2, and the bevelling of the clamping body 1 also sets a limit to how far the clamping body 1 can be inserted into the guide sleeve 2.'
The connector according to the invention may be mo¬ dified in many ways in relation to the above embodiment. For instance, the hook 20 and the engageable edge 8 may take the 'form of other engagement means, e.g. threads or the like. In this case, the assembling sequence may be changed in such a manner that the outer end of the clamp¬ ing body 1 is first engaged with one structural element, the connector being assembled thereafter. The hook 20 may also be adapted for engaging the hook of another clamping body.
It is, however, essential that the bore in the lock¬ ing sleeve receiving the clamping body forms a free space on the side of the clamping body opposite to the oblique surface, when the clamping body is received in both the guide sleeve and the locking sleeve, and the latter is displaced to the position inside the guide sleeve.