FR2635740A1 - Retractable stabilising prop for a movable structure - Google Patents

Abstract

A guide 3 is fixed to the vehicle. A plinth 19 is intended to bear on the ground 22. The plinth 19 is connected adjustably by a screw 24 to a slide 6 mounted with the possibility of tilting in the guide 3. When the plinth 19 is pressed on the ground, the slide 6, which is off centred with respect to the plinth, tends to tilt into a position for the interengagement of a spur 16 with a rack 17 opposing the riding up of the slide in the guide. This blocking is locked with the screw 24. In order to retract the prop, the screw 24 is retracted to disengage the spur 16, then a cable 37 is pulled which, due to its slantwise fastening to the slide 6, presses the slide against one wall 8 of the guide 3 opposite the rack. Use for stabilising vehicles for activities in stationary vehicles.

Description

 The present invention relates to a retractable stabilizing stand for a movable structure such as a vehicle. This kind of crutches is used for example on vehicles whose suspension must be neutralized during activities taking place in or on the vehicle when it is stopped. it may for example be a truck intended for medical activities.

 We know such a stand essentially consisting of a screw jack actuated by an electric motor.

To put the stand into service, the electric motor is turned in the appropriate direction until a base of the movable rod of the jack meets the ground.

 This device is expensive and also proves to be fragile.

 The object of the invention is to propose a more economical and more reliable device.

According to the invention, the retractable stabilizing stand, adjustable, intended to be mounted on a movable structure to stabilize it when stationary, is characterized in that it comprises
- a guide intended to be fixed to the movable structure
- a slide movable in the guide in a substantially vertical sliding direction in service;
- immobilization means for selectively immobilizing the slide in the guide in a position which can be chosen between a certain number of predetermined positions corresponding to various extensions of the slide relative to the guide; and
- A support base on the ground, connected to the slide by means of fine adjustment means of the position of the base relative to the slide.

 To put the stand into service, the slide is dropped until the base touches the ground, the slide is immobilized relative to its guide, then the fine adjustment is made by adjusting the position of the base relative to the slide .

 Thus, the invention has dissociated on the one hand rapid approach means, which can be of relatively economical invoice while being robust, and fine adjustment means, whose limited stroke allows an achievement of good mechanical quality without unduly burdening cost price.

In addition, by the movement of the slide in its guide, most of the movement is done very quickly by simply dropping the slide, which saves time.

 Other features and advantages of the invention will emerge from the description below.

In the accompanying drawings, given by way of nonlimiting example
- Figure 1 is a side elevational view of a vehicle fitted with crutches according to the invention
- Figures 2 to 5 are sectional views of a stand according to the invention, respectively in the retracted state when the base touches the ground; after tilting of the slide; and after adjustment of the fine adjustment means; and
- Figure 6 is a ~ sectional view along the line
VI - VI of Figure 2.

 In the example shown in Figure 1, the invention is applied to a vehicle intended for medical activities, comprising a habitable rear bodywork (1), of generally parelelepipedal shape, each of the four lower angles of which is provided with a retractable stabilizing stand (2). In the position shown in solid lines, the stand is in the retracted position, which allows the vehicle to move. When the vehicle has to be stopped for medical activities, it is necessary that the body floor is stabilized, and in particular the floor is not subject to oscillations due to suspension. For this, each stand is placed in the position shown in broken lines, or extension position, in which it rigidly supports the floor of the vehicle regardless of its suspension.

 As shown in Figures 2 and 6, each stand (2) comprises a guide (3) of tubular shape with rectangular cross section, intended to be -fixed vertically to the body (1) of the vehicle (or to the chassis thereof) by means of a fastening tab (4).

 In the guide (3) is mounted a slide (6) of elongated shape in a direction which, in service, is substantially vertical. As shown in Figure 6, the slider (6) has a square cross section and has only one lateral sliding clearance between the large faces (7) of the guide (3), and a greater clearance (j) between the small faces (8, 9) of the guide (3). However, at a lower end of the guide (3) through which the slide (6) passes, the small face (9) is connected to a flange (11) directed towards the small face (8). The slider (6) has only a minimum play of movement between the small face (8) of the guide (3) and a binding end (12) of the flange (11).

 Thus, in traversing its clearance (j), the slide (6) is movable between the position shown in Figures 2 and 3, in which one (32) of its faces is pressed against the face (8) of the guide (3 ), and a position in which an inner end (13) of the slide (6) has approached the face (9) of the guide (3), as shown in Figures 4 and 5. To pass from one at the other of these positions, the slide (6) pivots about an immaterial axis (14) (Figures 3 to 5) substantially located halfway between the wall (8) and the free edge (12) of the flange (11).

 In the position of Figure 2, or sliding position, the slider (6) can freely slide inside the guide (3).

 In the position of Figures 4 and 5, or locking position, a spout (16) formed at the inner end (13) of the slide (6) towards the face (9) of the guide (3) engages between the teeth of a rack (17) formed along the inner surface of the wall (9) of the guide (3).

The orientation of the spout (16) and that of the teeth of the Iberian cremail (17) is such that the rack (17) prohibits the ascent of the slide (6), but allows the descent of the latter. when the slide (6) is in the position of
Figures 4 and 5.

 In Figures 2 to 5, the play (j) has been exaggerated for the sake of clarity. In practice, a clearance (k) of a few tenths of a millimeter between the ends of the teeth of the rack (17) and the end of the spout (16) is sufficient.

 At its outer end (18), directed downwards in service, the slide (6) is associated with a base (19) of general pyramidal shape, the base (21), opposite to the slide (6), is intended to take support on the ground (22) when the stand is in the extended position (Figures 3 to 5).

 The base (19) is connected to the slide (6) by means of a device (23) for fine adjustment of the distance between the base (19) and the end (18) of the slide (6), such distance than measured parallel to the longitudinal direction of the slide.

 The device (23) comprises a screw (24) which is in screw connection with a threaded plug (26) crimped in the tubular body of the slide (6) at the outer end (18) of the latter.

 The outer end of the screw (24) is integral with a ball joint (27) which is trapped in a spherical housing (28) formed at the top of the base (19). The internal radius of the housing (28) is larger than the radius of the ball joint (27), which therefore has a certain radial clearance in the housing (28).

 The threaded opening (29) (Figure 2) of the plug (26) is offset so as to be further from the wall (31) of the slide (6) provided with the spout (16) than from the wall (32) of the slide (6) opposite the wall (31). This results in an offset (d) between on the one hand the axis of the screw (24), which is parallel to the length of the slide (6) and passes through the center of the ball joint (27), and on the other share the center of gravity (G) of the assembly formed by the slide (6) and the screw (24) as well as by the elements rigidly connected to these, such as the ball joint (27).

 When the base (19) is at a distance from the ground (22) (Figure 2) the base (19) centers on the ball joint (27) because the opening (33) of the housing (28) is centered relative to the axis of the housing (28) and because the edge of the opening (33) rests on its entire periphery against the spherical surface of the ball joint (27).

When the base meets the ground (22) (Figure 3), it is the lower end of the ball joint (27) which comes to rest against the bottom of the housing (28). The slide (6) therefore only rests by this single point, and it tends to tip over to the side where the center of gravity (G) is located with respect to this point. Thanks to the offset (d) above, the center of gravity (G) is located on the side of the rack (17). The slide therefore tilts towards the rack (17). This is the situation shown in Figure 4. This tilting takes place around the axis (14) and it is allowed by the play of the ball joint (27) in its housing (28). It suffices that the radial clearance of the ball joint (27) is of the same order of magnitude as the clearance (k) between the ends of the teeth (17) and of the spout (16), so that the clearance of the ball joint allows the end of the spout (16) to engage between the teeth of the rack (17). Therefore, the slide (6) can go back into the guide (3) only the small distance separating the spout (16) from the tooth (17a) located just above. The tooth (17a) which is located above the spout (16) is a function of the stroke that the slide (6) should have completed between its retracted position shown in Figure 2 and the position of Figures 3 and 4 in which the base (19) met the ground. Thus, the descent of the slide (6) from its retracted position shown in the
Figure 2 to its position in Figures 3 and 4 constitutes an approach movement at the end of which a selection is made between different predetermined positions of extension, each defined by one of the teeth of the rack (17 ).

 To raise the slide (6) until the spout (16) rests against the tooth (17a), and possibly to lift the guide (3) relative to the ground so as, for example, to adjust the horizontality of the vehicle floor, or to stabilize the blocking of the slide (6) relative to the guide (3), the device is actuated.

fine adjustment (23) by means of a handle (34) which is associated with the screw (24) between the latter and the ball joint (27) so as to allow a torque to be exerted on the screw (24 ) around its axis. The situation after action on the adjustment device (23) is shown in Figure 5.

 The stand according to the invention further comprises actuating means for retracting the slide (6) in the guide (3). The means (36) comprise a cable (37) of which an inner end (38) is fixed to the slide (6) and an outer end (39) is accessible to the user on the side of the guide (3) and can be fixed removably to a hook (41) fixed laterally to the outer side of the face (9) of the guide (3), in the vicinity of the lower end of the latter. Between its two ends, the cable (37) rotates a pulley (42) rotatably supported at the top of the guide (3) around an axis (43) extending in service substantially horizontally. It is therefore possible to retract the slide ( 6) by pulling the end (39) of the cable down and, when the end (39) is hooked to the hook (41), the slide (6) is in the retracted position (Figure 2). Preferably, the pulley (36) is located at an equal distance between the walls (7) of the guide (3) (Figure 6).

 When, on the contrary, the cable (37) is released, for example by unhooking the end (39) of the hook (41), the slide (6) is dropped, which will therefore take its extension position in Figures 3 by gravity at 5.

 So that traction exerted on the cable (37) effectively makes it possible to return the slide (6) to the retracted position, means are provided so that the immobilization means constituted by the spout (16) and the rack (17) are neutralized during this operation.

 As part of these neutralization means, the cable (37), from its end (38), deviates obliquely from the wall (9) carrying the rack (17). Thus, the traction (F) exerted by the cable (37), the direction of which is identical to that of the cable, comprises a component (Fl) directed laterally towards the wall (8), and which therefore tends to spread the beak ( 16) of the rack (17).

 For this spacing to be effectively possible, it is first necessary to retract the fine adjustment device (23), that is to say to turn the screw (24) by means of the handle (34) so as to bring in a larger part of the screw (24) in the slide (6), so as to pass the stand from its state shown in Figure 5 to its state shown in Figure 4 where the spout (16) can move away of the rack (17) by simple lateral movement of the slide (6) in the direction of the wall (8) of the guide (3).

 In service, when the vehicle is moving or is ready to move, the slide (6) is held in the retracted position by the cable (37) as shown in Figure 2.

When the vehicle stops at an activity site, the user releases the cable (37) of each stand so as to drop the slide (6) until the base (19) meets the ground. The slide (6) falls in principle with support against the wall (8) of the guide (3). However, if for reasons of inclination of the vehicle, the slider (6) tends to tilt towards the rack (17), this does not prevent it from falling since the rack is of the exhaust type in the direction of descent.

 As mentioned above, when the base (19) meets the ground (22), the slide (6) swings towards the rack (17) (Figure 4), after which the user puts the system in compression by actuating the fine adjustment device (23).

 To restore the vehicle to driving order, we start by actuating the fine adjustment device (23) in the opposite direction, so as to retract the screw (24) in the slide (6), then pull on the cable (37) , which has the effect of pressing the slide (6) against the wall (8) of the guide (3), then raising the slide (6) to the retracted position, after which it is possible to hang the end (39) to the hook (41).

 Of course, the invention is not limited to the example described and shown, and numerous modifications can be made to this example without departing from the scope of the invention.

 The ground as described could be replaced by a base comprising on the top a central recess the bottom of which is curved upwards, for example spherically.

 This base is not permanently connected to the screw.

On the contrary, the lower end of the screw has a concave end of corresponding sphericity. To put the stand in the extended position, first place the bases under the stands, then drop the slide as described until the lower end of the screw meets the curved bottom of the base in its region central then ripe towards the deeper peripheral region, which causes the slider to tip over and mesh with the slider's beak with the guide rack.

 Instead of presenting a clearance such as (j) in order to be able to inter-engage with the rack (17) or to disengage therefrom, the slide (6) could be slidably mounted without play in the guide. He would then carry a retractable pawl whose movement would be controlled by the cable so that the cable begins by retracting the pawl, against a return spring, before starting to pull the slide upwards when the pawl is arrived in the retracted position against a stop.

 The invention is also applicable to so-called "shelters" enclosures which are moved on a loading platform of a truck. Once the truck carrying the enclosure has reached the site of use, where the enclosure will generally serve as professional, medical or military premises, the crutches are placed in the extended position to raise the enclosure relative to the platform of the truck, then the truck is moved forward so that it sets out again, leaving the enclosure on site. Reverse operations allow the enclosure to be replaced on the same truck or another truck at the end of the service period.

Claims (13)

 1. Retractable stabilizing stand of adjustable length, intended to be mounted on a movable structure (1) to stabilize the latter when stationary, characterized in that it. understands  - a guide (3) intended to be fixed to the movable structure  - a slide (6) movable in the guide (3) in a substantially vertical sliding direction in service  immobilization means (16, 17) for selectively immobilizing the slide in the guide (3) in a position which can be chosen between a certain number of predetermined positions corresponding to various extensions of the slide (6) relative to the guide ( 3); and  - A base (19) for supporting the ground, connected to the slide (6) by means (23) of fine adjustment of the position of the base (19) relative to the slide (6).  2. Stand according to claim 1, characterized in that it comprises actuating means (37) for retracting the slide (6) in the guide (3), these actuating means being adapted to neutralize the means of immobilization (16, 17) at the start of the movement of withdrawal of the slide (6) in the guide (3).  3. Crutch according to claim 1 or 2, characterized by means (9, 27, 28) for activating the immobilization means (16, 17) when the base (19) meets the ground (22).  4. Crutch according to claim 1, characterized in that the means for selectively immobilizing the slide comprise engagement means (16, 17) carried by the slide (6) and by an internal surface of the guide (3), and means (j, d, 27, 28, 11) for selectively placing the meshing means in mutual engagement in different relative positions thereof.  5. Crutch according to claim 4, characterized in that the means for selectively bringing the meshing means into mutual engagement comprise a clearance (j). of the slide (6) in the guide (3) in a direction of mutual separation and reconciliation of the engagement means (16, 17).  6. Crutch according to claim 5, characterized in that the means for selectively bringing the meshing means into mutual engagement comprise a positioning (d) of the center of gravity (G) of an assembly comprising the slide (6) relative to the base (19), this positioning being such that the slide (6) switches in the direction of mutual approximation of the engagement means (16, 17) when the base (19) meets, in service, the ground (22).  7. crutch according to claim 5 or 6, characterized in that the slider clearance is a tilting clearance around an axis (14) near one end (11) of the guide (3) which is traversed by the slider .  8. Crutch according to one of claims 5 to 7, characterized in that it comprises actuating means (37) for retracting the slide (6) in the guide (3), these means being adapted to exert on the slide (6) a traction (F) of which a component (Fl) is directed opposite the engagement means (17) carried by the guide (3).  9. Crutch according to one of claims 4 to 8, characterized in that the means for selectively bringing the meshing means (16, 17) into mutual engagement comprise means for shifting so that the slide undergoes relative to the base ( 19), when it is supported on the ground (22) by means of the base (19), a displacement of the plate ensuring, in the guide (3), the mutual engagement of the engagement means (16, 17) .  10. Crutch according to claim 9, characterized in that the offset means comprise a clearance in a ball joint (27, 28) connecting the slide (6) to the base (19).  11. Crutch according to claim 10, characterized in that the engagement means (6) comprise a rack (17) carried by said internal surface of the guide (3), and a spout (16) carried by the slide (6) in the vicinity of an inner end (13) of the latter.  12. Crutch according to one of claims 4 to 11, characterized in that the engagement means (16, 17) are of a type allowing, when engaged, a movement of the slide (6) in the sense of extension.  13. Crutch according to claim 2 or 12, characterized in that the actuating means comprise a cable (37) attached to an inner end (13) of the slide (6) and bypassing a pulley (42) bridged at the top of the guide (3), a free end (39) of the cable (37) which can be fixed to the guide (3) to retain the slide (6) in the retracted position.