FR2787777A1 - Elevator platform ramp has pivoting access ramp with locking plate that moves vertically to lock ramp in upwardly inclined position and release it when returned to ground - Google Patents

Abstract

The platform (1) has an auxiliary actuator (6) located underneath it, and this controls the access ramp (4). It is connected to the same power source (3) as the principal actuator (2) to be activated at the same time as when the principal actuator is operated. In this way the ramp is moved to an upwardly inclined stop position. A locking plate (13) that can move freely in the vertical direction is arranged under the platform.

Description

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  CONTROLLING THE PIVOTING OF THE PLATFORM ACCESS RAMP

ELEVATOR SHAPE

  The present invention relates to a lifting device with a mobile platform provided with a lifting access ramp. Lifting devices are already known which are used to move loads from a lower level to a higher level or vice versa. These lifting devices are used in particular with wheeled carts carrying loads or even wheelchairs for the disabled, etc. Generally, these lifting devices, owing to their type of construction, impose a stop of the mobile platform, in its lower end position, at a certain level above the ground. Therefore, to be able to easily mount a trolley or wheelchair on the platform, preferably use a ramp access to the platform which ensures continuity between the ground level and that of the platform in the lower end position. This ramp can be independent or articulated

  along one of the edges of the platform.

  The present invention relates to improvements made to these lifting devices by providing a device of particularly simple design for controlling the pivoting movement of the access ramp associated with the platform and also using this ramp as a stop. safety during movement

vertical of the platform.

  To this end, this lifting device with a mobile platform controlled by a main cylinder connected to a source of pressurized fluid and with a downstroke stopping in a lower end position located at a predetermined level above the ground. , this platform comprising, along one of its edges, an access ramp articulated around a horizontal axis, extending down to the ground, in an inclined position, when the platform is in its lower end position, so as to allow a rolling cart to have access to the platform, is remarkable in that the platform comprises, below it or in its thickness, an auxiliary actuator for controlling the movement of the ramp, connected to the source of pressurized fluid so as to pass into the active position at the same time as the main actuator is supplied to cause the upward movement of the platform, in order to pivot remove the ramp in a stop position inclined upwards, a blocking device for the ramp in the stop position, mounted freely movable, vertically, under the platform, passing into the active blocking position from the start of the upward movement of the platform in order to maintain the ramp in the stop position inclined upwards after the supply of the auxiliary jack has been cut off, this blocking member coming into contact with the ground at the end of the downward travel of the platform and then automatically passing into the inactive unlocking position to release the ramp which then falls, under the effect of its

  own weight, in access position inclined downwards.

  An embodiment of the present invention will be described below, by way of non-limiting example, with reference to the accompanying drawings in which: - Figure 1 is a vertical sectional view of a

  lifting device according to the invention, with its platform

  shape in the lower end position and its ramp in the access position, - Figure 2 is a partial vertical sectional view of the lifting device showing the ramp moved to the stop position, inclined upwards, before the start of the rise of the platform, Figure 3 is a partial vertical sectional view showing the platform shortly after the start of its rise - Figure 4 is a perspective view of the organ

blocking the ramp.

  The lifting device according to the invention which is shown in Figures 1 to 3 comprises a horizontal platform 1 which is mounted vertically movable, on a suitable support frame, not shown, under the control of a main cylinder 2 , pneumatic or hydraulic, connected to a source of pressurized fluid 3 by

  through an appropriate distributor not shown.

  The platform 1 comprises along one of its edges la, a ramp 4 which is articulated around a horizontal axis 5 extending along the edge la. In the nonlimiting embodiment shown, the ramp 4 has a cross section in the shape of a right triangle and in the access position shown in FIG. 1, the short side 4a of the right angle extends vertically in below the pivot axis 5, the large side 4b of the right angle extends horizontally in contact with the ground and the hypotenuse 4c is inclined downward from the pivot axis 5. This axis of pivot is located at the point of the common vertex on the short side of the angle

  right 4a and to the hypotenuse 4c of the ramp 4.

  The lifting device according to the invention also comprises, below the platform 1 or optionally in its thickness, a device for controlling the pivoting movement of the ramp 4 around the axis 5. This device comprises an auxiliary jack 6, extending horizontally and supported by the platform 1. The rod 6a of this jack 6 extends horizontally to the right, that is to say towards the ramp 4. Its right end is in contact with the face left front 7a of a horizontal pusher 7 which is slidably mounted in an axial bearing 8 integral with the platform 1. This pusher 7 which is in contact by its right end 7b, with the small vertical side 4a of the ramp 4 , is biased to the left in Figure 1, that is to say towards the cylinder 6, by a return spring 9. This spring can be constituted by a helical spring wound around the pusher 7 and bearing, its right end, on the left side of the axial bearing 8, and at its left end, on a washer 11 surrounding the pusher 7 and retained by

a key 12.

  The device for controlling the movement of the ramp 4 - 4 furthermore comprises a member 13 for locking the ramp 4 in the stop position inclined upward as it appears in FIGS. 2 and 3. This locking member 13 is constituted by a sheet metal element comprising two opposite lateral and vertical wings 13a, 13b pierced with holes 14 coaxial in the transverse direction serving for the passage of an axis of articulation. The axis of articulation of the blocking member 13 may be the axis 5 around which the ramp 4 pivots, as is the case in the embodiment shown. However, the articulation axis 13 could also be independent of the axis 5. The locking member 13 which is open to the right in the figures, furthermore comprises a bottom 13c extending horizontally between the two lateral wings 13a, 13b and a vertical rear wall 13d extending upwards and connected both to the wings 13a, 13b and to the bottom 13c. The vertical rear wall 13d is pierced with a light 15 elongated in the vertical direction. This light 15 is crossed by the pusher 7, as shown in FIG. 1, and it has a horizontal width or dimension substantially equal to the diameter of the pusher 7. On the other hand, its height or vertical dimension is a little greater than the diameter of the pusher 7 so that the blocking member 13 can perform a vertical movement of amplitude limited by

compared to this pusher.

  The operation of the lifting device according to the invention will now be explained. In the position illustrated in FIG. 1, the platform 1 is in its lower end position and the ramp 4 is in the access position while being inclined downwards. It is thus very easy to mount a wheelchair for example on the platform 1 by passing it over the inclined face 4c of the ramp 4. Once the wheelchair placed on the platform 1, the climb is controlled of the platform 1 by supplying, by a suitable valve not shown, the jack 2. Simultaneously, the second jack 6 is fed by the bottom and its piston rod 6a is pushed to the right. The piston rod 6a then causes the pusher 7 to slide in the axial bearing 8, to the right, against the action of the return spring 9 which is then compressed. The pusher 7 being pushed to the right, its right end 7b exerts a pressure on the small vertical side 4a of the ramp 4 so that the latter pivots upwards, anticlockwise, to reach the upwardly inclined stop position which is shown in FIG. 2. This figure represents the extreme position reached by the piston rod 6a and the pusher 7. In this position, the left front face 7a of the pusher 7 has been moved to the right, beyond the lumen 15 of the blocking member 13. This blocking member is, as for

  him, always in the same position, because, the platform

  form 1 having not yet started its ascent, its bottom 13c

is in contact with the ground.

  As soon as the platform 1 begins to rise, the bottom 13c of the blocking member 13 progressively moves away from the ground and as it is mounted to pivot freely around the horizontal axis 5, it in turn pivots slightly in anti-clockwise, as shown by the arrow F in FIG. 3. As a result of this pivoting movement, the rear wall 13d of the locking member 13 descends slightly until the 'upper end of the light 15 abuts against the end of the piston rod 6a engaged in the light 15. The left front face 7a of the pusher 7 is then in contact with the part of the rear plate 13d which is located just above the port 15. The member 13 is thus placed in a position for blocking the pusher 7 in the active position, the spring 9 then compressed pushing this pusher against the rear wall 13d above the port 15. A from this moment the food cylinder 6 can be cut and the ramp 4 is held in its upwardly inclined stop position by the locking member 13, during all the rest of the upward movement and

  also down from platform 1.

  When at the end of its descent, the platform 1 - 6 - arrives shortly before its lower end position, as shown in FIG. 1, the blocking member 13 which then acts as a feeler back on the ground, comes into contact with the ground through its bottom 13c. This contact then causes a pivoting movement of the locking member 13 in the clockwise direction. As a result of this movement, the rear wall 13 is moved upwards and the light 15 is then presented in front of the pusher 7 which can be pushed to the left, through this light 15, under the action of the spring 9. The pusher 7 then occupies the position shown in FIG. 1 and the ramp 4 drops back into the access position under

the effect of its own weight.

  According to a particularly advantageous variant of the lifting device, the rod of the pusher 7 can be lengthened on the side of its straight end (7b) as shown in FIG. 3 in thin dashed line. In this configuration, when the jack (6) is fully extended in the extreme position corresponding to the lifting of the ramp 4, the end 7b of the pusher 7 which was in the previous variant in contact with the small side 4a of the ramp 4 continues its course to the right and exceeds line 16 (Figure 3) corresponding to the intersection of the small and large side of the ramp 4; the latter in the upwardly inclined position, is in contact with the upper generator of the pusher 7 by its line 16. Ultimately, the ramp 4 is thus in transverse support on the pusher 7, that is to say that it does not create a setback torque as in the previous variant. As shown in thin dashed line in FIG. 3, the platform 4 is mechanically locked between two practically fixed support points, the joint 5 and the top

  intersection between the small and the long side of the ramp.

  It will be understood that such a variant constitutes an additional degree of security for the load transported on the platform, which abuts during transport on the raised ramp 4, is thus retained in its horizontal movements towards the vacuum c ' that is to say towards the - 7 -

right of figure 3.

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Claims (9)

  1 - Lifting device with mobile platform (1) controlled by a main cylinder (2) connected to a source of pressurized fluid (3) and with a downstroke stopping in a lower end position located at a predetermined level above the ground, this platform (1) comprising, along one of its edges (la), an access ramp (4) articulated around a horizontal axis (5), s' extending down to the ground, in an inclined position, when the platform (1) is in its lower end position, so as to   allow a rolling cart to access the platform   form (1), characterized in that the platform comprises, below it or in its thickness, an auxiliary jack (6) for controlling the movement of the ramp (4), connected to the source of pressurized fluid (3) so as to pass into the active position at the same time as the main cylinder (2) is supplied to cause the upward movement of the platform, in order to rotate the ramp (4) in an inclined stop position upwards, a member (13) for locking the ramp (4) in the stopped position, mounted freely moving, in the vertical direction, under the platform (1), passing into the active position of   blocking from the start of the platform lifting movement   form in order to maintain the ramp (4) in the stop position inclined upwards after the supply of the auxiliary jack (6) has been cut off, this blocking member (13) coming into contact with the ground at the end of the downward travel of the platform and then automatically passing into the inactive unlocking position to release the ramp (4) which then falls, under the effect of its own weight, into position access inclined downwards.   2 - lifting device according to claim 1, characterized in that the auxiliary jack (6) extends horizontally and comprises a piston rod (6a) in contact with a front face (7a) of a horizontal pusher (7), sliding horizontally in an axial bearing (8) and in contact, by its end (7b) opposite to - 9 -   its front face (7a), with the ramp (4).   3 - lifting device according to claim 2 characterized in that the pusher (7) is pushed towards the   auxiliary cylinder (6) by a return spring (9).   4 - Lifting device according to any one of   claims 2 and 3, characterized in that the ramp (4) has   a cross section in the shape of a right triangle having a short side of the right angle (4a) extending vertically in the access position of the ramp (4), a long side of the right angle (4b) extending horizontally and in contact with the ground, and a hypotenuse (4c) inclined downwards, the axis of articulation (5) of the platform (4) being situated at the location of the vertex common to the short side of   the right angle (4a) and the hypotenuse (4c) of the ramp 4.   5 - lifting device according to claim 4 characterized in that the end (7b) of the pusher (7) is in contact with the face (4a) of the ramp (4) corresponding to its short side when it is in position d 'stop, tilted up.   6 - lifting device according to claim 4 characterized in that the length of the push rod (7) is such that in the stop position inclined upwards of the ramp (4), it comes to rest on a generator of the push rod (7) by the line (16)   of intersection of its perpendicular faces (4a) and (4b).   7 - Lifting device according to any one of   claims 2 to 6, characterized in that the   blocking (13) is open in the direction of the ramp 4, it is articulated around the articulation axis (5) of the ramp (4), and it has a vertical wall (13d) pierced with a light (15 ) extended in the vertical direction and crossed by the pusher (7) when the ramp (4) is in access position.   8 - lifting device according to claim 7, characterized in that the vertical light (15) has a width or horizontal dimension substantially equal to the diameter of the pusher (7) and a height or dimension   vertical greater than this diameter. - 10 -   9 - lifting device according to any one of claims 7 and 8, characterized in that the member   blocking 13 comprises a horizontal bottom (13c), intended to come into contact with the ground, integral with two lateral and vertical wings5 (13a, 13b) pierced with holes (14) for the passage of the articulation axis (5) of the organ of   blocking (13), the vertical wall (13d) extending along the bottom (13c) and between the two lateral wings (13a, 13b).