WO2002075166A1

WO2002075166A1 - A mechanism for locking and fixing an elongated first part displaceable in a second part

Info

Publication number: WO2002075166A1
Application number: PCT/SE2002/000418
Authority: WO
Inventors: Stefan Wallin; Per YTTERåKER
Original assignee: Casun Ab Bygg Och Industriservice
Priority date: 2001-03-16
Filing date: 2002-03-08
Publication date: 2002-09-26
Also published as: SE0100937D0; SE518703C2; SE0100937L

Abstract

This invention relates to a mechanism for locking and clamping an elongated first part (2) which is displaceable in a second part (3), including a tilting device (9), which by means of a force generator is tiltable between different angle positions in order to clamp the first part in a locked state in relation to the second part as well as disengage the same in order to enable displacement in relation to the other part. According to the invention, the force generator consists of a screw (8), which on one hand is in engagement with a female thread in a link-like element (18), which is turnable by being connected to a fastener (7) via a first hinge (17), and on the other hand is connected to the tilting device (9) via a cross piece (13), which is axially immobile in relation to the screw, but enables rotation of the same, and which in turn is connected to the tilting device via a second hinge (14), which has the purpose of allowing tilting of the same between locking and disengaging angle positions.

Description

A MECHANISM FOR LOCKING AND, FIXING AN ELONGATED FIRST PART DTS LACABLE IN A SECOND PART

Technical Field of the Invention This invention relates to a mechanism for locking and clamping an elongated first part displaceable in a second part, including a tilting device which by means of a force generator is tiltable between different angle positions in order to clamp the first part in a locked state in relation to the second part, as well as disengage the same in order to enable displacement in relation to the second part.

The locking mechanism according to the invention is particularly suitable for locking at least two tubes, included in a telescope construction, in relation to each other, as well as applying a tensional force to the telescope construction.

Prior Art

A locking mechanism intended for telescope constructions of the type generally mentioned in the preamble is previ- ously known by US 3 883 106. In this case, the tilting device consists of a hole-provided plate, which is articulatedly connected to a force generator in the form of a bell crank mechanism which includes a main arm and a pair of links articulatedly connected therewith. When the main arm is kept in a turned-out position from the telescope construction, an inner tube included therein may freely pass in either direction through the hole of the tilting device. In order to lock the tubes in a desired position in relation to each other, the main arm is turned inwards towards the telescope construction, a hinge between the main arm and the link pair passing a dead centre in order to bring about a self-clinching of the locking mechanism in a state in which the tilting device clamps said inner tube so that the same may not be displaced in relation to an outer tube. A drawback of the locking mechanism known by US

3 883 106 is that the bell crank mechanism after the locking of the inner tube of the telescope construction is not able to move the inner tube in relation to the outer tube more than a short distance. This means that the telescope construction may be applied only mediocre tensional forces. Another drawback is that the handling of the telescope construction and the locking mechanism thereof in connection with mounting and dismounting is cumbersome.

Objects and Features of the Invention

The present invention aims at obviating the abovementioned drawbacks of the previously known locking mechanism and at providing an improved locking mechanism. Therefore, a primary object of the invention is to provide a locking mechanism which enables the transfer of great tensional forces to the movable part, which is to be kept locked. An additional object is to enable a simple and convenient handling of the locking mechanism as well as the movable part in connection with not only the locking and the clamping, but also the disengagement of said part. Yet an object of the invention is to create a locking mechanism especially suitable for telescope constructions, which may, if required, automatically lock an inner tube included in the telescope construction in relation to an outer tube, in connection with the mounting of the telescope construction between, for instance, a ceiling and a floor. It is also an object to provide a locking mechanism, which is robust and structurally simple.

According to the invention, at least the primary ob- ject is attained by the features defined in the characterizing ^ clause of claim 1. Preferred embodiments of the invention are furthermore defined in the dependent claims .

Further Elucidation of Prior Art Locking mechanisms for telescope constructions are previously known by GB 1 297 434, GB 1 470 511, US 3 930 645 and DE 4 132 070. No more than the above-mentioned US 3 883 106, however, the locking mechanisms according to these patent publications make use of any screw in order to transmit ten- sional forces to the inner tubes of the telescope constructions. Brief Description of the Appended Drawings

In the drawings : Fig 1 is a perspective view of a telescope construction having a locking mechanism according to the invention, Fig 2 is a cut longitudinal view showing the locking mechanism from one side on an enlarged scale, Fig 3 is an additionally enlarged, perspective view showing the locking mechanism obliquely from the front, Fig 4 is an analogous perspective view showing the same locking mechanism obliquely from behind,

Fig 5 is a longitudinal section showing the locking mechanism in a locking position, Fig 6 is an additionally enlarged section showing the locking mechanism in a disengaging position, and Fig 7 is a section corresponding to fig 6 showing the locking mechanism in a locking position.

Detailed Description of a Preferred Embodiment of the Invention In fig 1, 1 generally designates a telescope con- struction which includes a first tube 2 which is more slender than a second tube 3 and inserted into the same in order to be displaced into and drawn out, respectively, with the purpose of varying the length of the telescope construction. In the example, the telescope construction has the form of a brace of the type that may be mounted between a ceiling and a floor and be fixed therebetween. In this case, the thick outer tube -3 is turned downwards and the slender inner tube 2 is turned upwards. At the opposite ends thereof, the brace has support feet 4, which advantageously are connected to the telescope tubes via hinges 5. It should furthermore be noted that the two telescope tubes in the example have a quadrangular, particularly square cross-section shape, although the invention is not limited to this type of tubes (for instance, the tubes may be cylindrical) . In practice, the telescope tubes may consist of box profiles, e.g., of aluminium and steel, respectively.

At the upper end of the outer tube 3, a locking mechanism according to the invention is arranged, in its entirety designated 6. Reference is now made to figs 2-7, which in detail illustrate the locking mechanism 6. As is best seen in fig 3, the locking mechanism includes a fastener, generally designated 7, a force generator in the form of a screw 8, as well as a tilting device, in its entirety designated 9.

The tilting device 9 is in the example composed of two spaced-apart, mutually parallel side plates 10, 10' between which two carrier members in the form of pins 11, 12 extend, as well as a cross piece designated 13. At the two opposite ends thereof, said cross piece 13 has rotationally symmetrical shaped projections 14, which engage holes in the side plates 10, 1_.0' in order to form a hinge or a geometric axis around which the cross piece 13 may turn.

Like the tilting device 9, the fastener 7 includes two side plates 15, 15' that are spaced-apart and mutually parallel. Between the side plates 15, 15', a uniting peg 16 as well as a cylindrical pin 17 extend, which serves as a hinge for a link-like element 18, with which the screw 8 is connected. More precisely, the element 18 consists of a robust body of metal through which a through hole 19, having a female thread, extends. In the exemplified embodiment, the inner end of the element 18 is stiffly united (e.g. by welding) to a sleeve 20 which surrounds the pivot pin 17. Thus, the element 18 may turn around the pivot pin 17. The two side plates 15, 15' are stiffly united to the outer tube 3 in a suitable way, e.g. by being welded on the end edges thereof.

Along a substantial part of the length thereof, the screw 8 has a male thread 21. In practice, the length extension of the thread 21 may be within the range of 50-100 mm. The male thread 21 of the screw as well as the co-operating female thread in the hole 19 may advantageously consist of comparatively rough trapezoidal threads. At the lower part thereof, the screw 8 has a cylindrical portion 22, having a transverse hole for an elongated, displaceable handle 23 by means of which the screw may be rotated manually.

At the upper end thereof, the screw has an end portion 24 which runs through a central hole 25 in the cross piece 13. Adjacent to said end portion 24, a collar or collar-like shoulder 26 is formed, against which the bottom side of the cross piece 13 abuts. Above the cross piece 13, a nut 27 is tightened. Thus, the screw is connected with the cross piece 13 in such a way that the same may be freely rotated in relation to the cross piece, but cannot move axially in relation to the same. Between the cross piece 13 and the collar 26 and the nut 27, respectively, washers (not shown) may advantageously be arranged.

The two carrier members 11, 12 consist in the example of pins having a straight, substantially cylindrical basic shape, which are intended to be pressed against opposite, plane side surfaces of the inner tube 2 (see figs 6 and 7) . The pins 11, 12 are advantageously made of hardened steel and formed with axial countersinks 28, which are individually delimited by relatively sharp edges 29. When the two pins are pressed against the tube 2, as is shown in fig 7, one of said two edges 29 forms a sharp ridge on the individual pin, which guarantees a reliable grip against the tube.

The two carrier pins 11, 12 are, together with the hinge 14 for the cross piece 13, placed in a triangular con- figuration with the pin 12 located near the slender end of the tilting device which is designated 30, while the pin 11 and the hinge 14 are located near the end of the tilting device which is designated 31. The distance between the pins 11, 12 is greater than the thickness of the inner tube 2, counted as the perpendicular distance between opposite plane surfaces of the tube. When the locking mechanism is connected to a vertical brace or telescope construction, as is shown in the exemplified embodiment, the pin 11 is located highest, i.e. at a relatively large distance from the fastener 7. The carrier pin 12 is situ- ated on a lower level than the pin 11, i.e. closer to the fastener 7. The hinge 14 is located lowest, i.e. closest the fastener 7 in the triangular configuration.

The function and the Advantages of the Locking Mechanism According to the Invention

When the illustrated brace 1 (see fig 1) is to be applied and clamped between two spaced-apart objects, e.g. a ceiling and a floor, the procedure is as follows. In a starting position, the inner tube 2 is inserted a suitable distance into the outer tube 3. When the brace has been located in a vertical state with the support foot of the outer tube resting against the floor, the inner tube 2 is drawn up to a position in which the upper support foot is loosely pressed against the ceiling. Said drawing-up of the inner tube may be carried out with one hand without resistance by the locking mechanism. Thus, the upwardly directed motion of the inner tube 2 applies to the tilting device 9 a tendency to turn upwards or clockwise around the hinge 14 according to the arrow A in fig 6. This disengaging state of the locking mechanism is illustrated in an exaggerated way in fig 6, where the carrier pin 12 is shown somewhat spaced-apart from the inner tube 2. In reality, however, the two carrier pins 11 continuously abut the inner tube during the drawing-up of the same, more precisely as a consequence of the fact that the tilting device by the own weight thereof aims at turning anti-clockwise around the hinge 14 (as seen in figs 6 and 7) . When the upper support foot 4 reaches the ceiling, the operator may drop the inner tube 2, the locking mechanism 6 automatically and immediately locking the inner tube in the po- sition in question. This takes place by the fact that the own weight of the inner tube 2 applies to the tilting device a downward torque, which brings about a clamping of the inner tube between the two pins 11, 12 (see fig 7) . In order to hereafter clamp the brace with the desired tensional force, the screw 8 is activated. More precisely, the operator applies to the screw 8 a rotational motion, which ensures that the tilting device, via the cross piece 13 and the hinge 14, is brought to move vertically upwards, i.e. distance itself from the fastener 7. Hereby, the clamping effect of the tilting device against the inner tube 2 is enhanced as a consequence of the fact that the screw applies to the tilting device a torque which additionally presses the pins 11, 12 and the sharp edged ridges 29 thereof against the inner tube 2. After tightening of the screw 8 some revolutions, the brace is fixed by a great force between the ceiling and the floor.

When the brace is to be dismounted, the screw 8 is loosened by being rotated some revolutions in the opposite direction to the tightening direction. Independently of how far the screw is loosened, the tilting device preserves the clamp- ing effect thereof on the inner tube 2. In order to insert or drop the inner tube 2 down into the outer tube 3, the operator may, with a light motion of the hand, turn the tilting device up around the hinge 11, e.g. to the position according to fig 6, at which the inner tube may freely move down into the outer tube 3. This restoring of the inner tube to the interior of the outer tube may advantageously take place in a controlled way by the operator holding the inner tube with one hand and dropping the same only a limited distance into the outer tube. An advantage of the locking mechanism according to the invention is that the same, thanks to the screw, may apply considerable tensional forces to a brace or the like. Another advantage is that the inner tube of the brace may be extracted a suitable distance from of the outer tube and automatically be retained in a given position before tightening of the screw is initiated. In an analogous way, the inner tube is retained in the given position thereof also in connection with loosening of the screw. In other words, the locking mechanism is self- clinching. Therefore, the locking mechanism and the inner tube may be handled in a convenient, fast and simple way in connection with the mounting as well as the dismounting of the brace. In addition, the locking mechanism is structurally simple and robust .

Feasible Modifications of the Invention

The invention is not solely restricted to the embodiment described above and shown in the drawings. Thus, the locking mechanism is also useful in connection with locking and clamping other elongated items than an inner tube in a brace or a telescope construction. It should here be pointed out that the locking mechanism works irrespective of whether the telescope construction is oriented vertically or not. Furthermore, the locking mechanism may be modified in various ways in order to fit tubes or other elongated items having another cross- section shape than quadrangular.

Claims

1. Mechanism for locking and clamping an elongated first part (2) which is displaceable in a second part (3) , including a tilting device (9) , which by means of a force generator is tiltable between different angle positions in order to clamp the first part in a locked state in relation to the second part, as well as disengage the same in order to enable displacement in relation to the second part, c h a r a c t e - r i z e d in that the force generator consists of a screw (8), which on one hand is in engagement with a female thread in a through hole (19) in, an element (18) which is turnable by being connected with a fastener (7) via a first hinge (17), and on the other hand is connected with the tilting device (9) via a cross piece (13), which is axially immobile in relation to the screw, but enables rotation of the same, and which in turn is connected with the tilting device via a second hinge (14) which has the purpose of allowing tilting of the same.

2. Mechanism according to claim 1, c h a r a c t e r i z e d in that the tilting device (9) includes two spaced-apart side plates (10, 10'), between which on one hand the second hinge (14) for the cross piece (13), and on the other hand two carrier members (11, 12) extend, and that the second hinge (14) and the two carrier members (11, 12) are placed in a triangular configuration with a first carrier member (12) located near an end (30) of the tilting device and a second carrier member (11) together with the second hinge (14) for the cross piece (13) located near the opposite end (31) of the tilting device.

3. Mechanism according to claim 2, c h a r a c t e r i z e d in that the individual carrier member consists of a pin (11, 12) having a straight, substantially cylindrical basic shape.

4. Mechanism according to claim 3, c h a r a c t e r i z e d in that the individual carrier member has at least one sharp-edged ridge (29) for pressing against the outside of the first part (2) to be locked.

5. Mechanism according to any one of the preceding claims, c h a r a c t e r i z e d in that the male thread of the screw (8) and the female thread of the hole (19) in the turnable element (18) consist of trapezoidal threads.

6. Mechanism according to any one of claims 2-5, c h a r a c- t e r i z e d in that the screw (8) has an end portion (24) which is inserted into a through hole in said cross piece (13) , the cross piece being fixed axially between a collar (26) and a nut (27) .