FR2471945A1 - LIFTING DEVICE, IN PARTICULAR FOR MOTOR VEHICLES - Google Patents

Abstract

THE INVENTION RELATES TO A LIFT DEVICE, IN PARTICULAR FOR MOTOR VEHICLES. IN THIS DEVICE, THE ELEVATION IS ASSURED BY A LIFTING NUT 2, LOCATED INSIDE A BODY 1 THAT IT ACCOMPANIES IN ITS UPWARD OR DOWNWARD MOVEMENTS BY MEANS OF A THREADED SHAFT. A SAFETY CABLE 4 IS ATTACHED TO THE BODY 1 AUDIT. A SAFETY NUT 3, ALSO LOCATED IN THE BODY 1 BELOW THE SAID NUT 2, IS IN TEACH WITH THE THREAD OF THE SHAFT AND MOVES ALONG THE VERTICAL LONGITUDINAL AXLE DUDIT BODY 1. A DISPLACEMENT OF THE NUT 3 FROM THE BODY 1 CAUSES THE MOVEMENT OF A RELEASE MECHANISM WHICH RELEASES CABLE 4 FROM THE BODY 1. THIS RELEASE MECHANISM CONSISTS OF A STUD 9 AND A TERMINAL 5. APPLICATION TO ELEVATORS, ESPECIALLY FOR MOTOR VEHICLES.

Description

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  The present invention relates to a lifting device, in particular for motor vehicles, in which the lifting movement is ensured by a lifting nut disposed inside a body and moved upwards or downwards at the same time. said body, inside an upright, by means of a threaded lifting shaft rotated and in contact with said lifting nut, a control or safety cable being fixed to said body housing said lifting nut, however a safety nut is also housed in

  said body, below said wash nut. The nut of

  tee is connected to the shaft by its tapping and is movable along the axis of the body. In elevating devices in which the lifting movement is ensured by means of a

  lifting nut and rotary shaft threaded rotary traverse

  said nut, it is normally desirable, and often necessary, that the raised load does not fall back when the

  tapping of the lifting nut is worn out.

  The prior art has already proposed lifting devices equipped with a safety system comprising a safety nut located at a certain distance below the lifting nut in the body, this safety nut being intended to support said lifting nut when its thread is worn, so that said safety nut performs the functions

  elevating and supporting said lifting nut.

  A lifting device of this type known can therefore continue to be used when the safety nut functions as a support and lifting nut, but the

  safety in the fall of the lifted load is total-

eliminated.

  To overcome such a disadvantage, it is known to fix a control or safety cable to the body surrounding the lifting nut, this cable controlling a switch that triggers the drive mechanism or the energy source of the lifting device when said body is slightly lowered as a result of falling or sliding down

  lifting nut, that is to say that the safety nut

  upwardly relative to said body and that the latter remains supported by the safety nut, via

  the lifting nut. In elevating devices in the-

  which several lifting nuts cooperate in synchronism,

  for example by means of chains, the safety cable can equally

  used to operate a switch, for example when

  the difference in height between said lifting nuts

  is too important, when one of these encounters an obstacle or an abutment hindering its movement, or when one of said nuts exceeds a maximum or minimum limit

of elevation movement.

  The safety cable is mounted with a certain

  before it declines, for example as a result of a break in the cable itself, the switch

  is operated as described above.

  As mentioned above, each lifting nut

  and its neighboring safety nut are located in an elongated body

  or bracket, in which these two nuts can not

  not rotate and in which, in addition, at least the safety nut

  reté is movable in the longitudinal direction of said body, between

  a lower stop of the latter and the lifting nut

  Underlying. Each body is torsionally proof and it is

  mobile vertically in its associated amount.

  When the safety cable interrupts the power supply

  the energy source of the lifting device or the mechanisms

  control systems and when, as a result, one or more used lifting nuts are replaced, the security system has perfectly fulfilled its function. However, when the lifting devices are stopped as a result of the action of the safety cable, some users of these devices display the skill and know-how necessary to readjust said safety cable.

  way that the lifting device can continue to function

  without the need to replace the lifting nut, but it also eliminates any safety with regard to the drop of the raised load when the thread of the nut

safety is also used.

  The lifting device according to the present invention does not have the aforementioned drawbacks, since the fastening means of the safety cable are designed such that a displacement of the safety nut relative to

  to his body entails the displacement of a releasing mechanism

  which, in turn, releases said securing means and, therefore, releases said safety cable from the body, the displacement of said safety nut relative to said body taking place longitudinally along and / or about the axis

  of said body. Therefore, the work that represents the

  precisely the safety cable is comparable to that needed to replace the lifting nut, which increases the probability of using the device safely, avoiding

  thus a fallout of the load raised.

  The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting examples and in which: Figure 1 is a longitudinal section of a body housing a lifting nut in a lifting device according to the present invention; Figure 2 is a cross section of the safety nut of Figure 1, having a recess with inclined surfaces; Figure 3 is a fragmentary axial section of the recess in the safety nut of Figure 1; Figure 4 is an overall perspective view of a lifting device according to the present invention; and FIG. 5 is a longitudinal section illustrating

  an alternative embodiment of the device of FIG.

  In Figure 1, there is shown a body 1 housing a lifting nut 2, mounted so as to be rotatable neither in the upper part nor in the lower part of said body 1, and a safety nut 3 movable longitudinally and

  at least partially prevented from turning, that is to say,

  At least one rotation of a small angle around the axis of the body 1. For the sake of clarity, the threaded shaft of the lifting device has been placed inside the nuts 2 and 3, of which the threads are engaged with the thread of said lift shaft. In this embodiment, a control or safety cable 4 extends from the top and downwards, along the body 1, the fastening means of this cable 4 being housed in said body 1, so that 'a

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  displacement of the safety nut 3 inside this body 1 actuates a disengagement mechanism which, in turn, breaks

  the connection between the cable 4 and the body 1.

  In the preferred embodiment of the body 1, illustrated in Figure 1, the fixing means consists of a pin 6 fixed perpendicular to the outer face of the

  wall of the body 1, as well as in a longitudinal mobile lug 5

  along said stud 6 and on the outer end of the latter, so that said lug 5 can be disengaged

  of the stud 6 when it is moved beyond said end

  externality of the latter. The release mechanism of the cable 4 has a recess 7 formed in the external lateral face

  of the safety nut 3. This recess 7 extends longitudinally-

  along the safety nut 3 and, as shown by the

  figures 2 and 3, it also extends transversely

  As illustrated in Figure 1, the recess 7 is delimited, in its lower region, by a ramp 8, inclined, circular or curvilinear. The release mechanism further comprises a loosening pin 9 movable longitudinally in a hole passing through the wall of the body 1, the inner end of this stud 9 being applied against the bottom of the recess 7, while its outer end is in contact with a release arm 10, one end of which extends in a space between the lug 5

  and the body l, surrounding the stud 6. In the form of

  As illustrated, the release pin 9 is welded to the release arm 10, the other end of which is attached to the upper side face of the wall of the body 1. The arm is shown in its release position, shown in dashed line after that he was moved out by

  the loosening pin 9, as a result of an upward movement

  corner of the safety nut 3 in the body 1,

  in which a ramp 8, 14 or 15 of this nut 3 pushed said pin 9 outwards and, consequently, the arm 10 pushed the lug 5 outwards beyond the free end of the stud 6, in order to release the cable prior tension of the latter causes a quick release of the lug 5 of the vicinity of the stud 6. At the same time

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  that the lug 5 has been moved outwardly, an L-shaped member, a gusset plate or an angle iron 12 of a deformable material has been bent outwardly if attached to the body, but not if it is attached to the end of the release arm 10. This angle 12 serves to keep in place the lug 5 on the end of the stud 6 under normal operating conditions of the lifting device. The lug can not be put back on the dowel 6 as long as the safety nut 3 prevents the loosening pin 9 from being pushed back into the recess 7 by the

  restoring force exerted by the arm 10.

  To prevent the release arm 10 from returning to its normal position (illustrated by solid line on

  1), the safety nut 3 can extend

  sufficiently low below the ramp 8, as shown in Figure 1, to prevent the fixing pin 6 to return to its normal position in the body 1, or this nut 3

  may have limited opportunities for upward

  it can only be moved upwards until the release pin 9, thanks to the ramp

  8, come to reach his position of relaxation, that he

  serve until the worn member, for example the lifting nut 2, has been replaced. When the release arm can not return to its initial position of Figure 1, the lug 5 can not be put back on the stud 6, and an alarm signal or an opening of the electrical circuit, due to the release of the safety cable 4, can not be interrupted

  or deleted, respectively, only by qualified personnel.

  Thus, the lifting device can not be used to continue the lifting of the load and, simultaneously, the release mechanism provides protection against wear

  and tearing of the lifting nut 2.

  To ensure that the safety nut 3 is not worn at the same time as the lifting nut 2, it is important to

  said nut 3 always accompanies, substantially without friction

  tion, said nut 2 on the threaded shaft. In the devices of this type known from the prior art, there is no such

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  control or protection organ of the safety nut 3.

  Under these conditions, the lifting device according to the invention proposes a solution in this sense, since the fastening means of the safety cable 4 are designed in such a way that the release mechanism can release the fastening elements and, in this way, In fact, release safety cable 4 from

  1 when the friction between the safety nut 3 and the

  Threaded force, hanging from its rotation, to exceed a

  their predetermined, that is to say when said nut 3 is prevented to a certain extent to follow the displacement of the lifting nut 2 relative to the threaded shaft. In a preferred embodiment of the safety nut 3, the recess 7 thus comprises two lateral ramps 14 and 15, inclined transversely, which may have a

  circular shape (see Figure 2) and extend to the periphery

  In addition, this nut 3 rotates about the axis of the body 1. This rotation of the nut 3 is limited to an angle corresponding to the extent of the two side ramps 14 and 15 of the recess 7. in the peripheral direction of the body 1 or the nut 3. FIG. 2 illustrates another recess which, opposite the recess 7, fulfills this function when

  houses a not shown stud, attached to the wall of the body 1.

  Rotation of the safety nut 3 relative to the body 1 causes a radial displacement towards the outside of the loosening pin 9 by the ramp 14 or 15 and,

  therefore, the release arm 10 is pushed towards the ex-

  In order to disengage the terminal 5, this rotation takes place while the lifting device raises or lowers the load that it supports. In this embodiment of the recess comprising two lateral ramps 14 and 15, it can also be provided the inclined ramp 8 extending in the longitudinal direction of the body 1, but this ramp 8 can also

  not be expected, in which case the friction between the

  and the safety nut increases when the load imposed

  to the lifting nut 2 is transmitted to the safety nut 3.

  This increased friction results in the above rotation.

  nut 3 with respect to the body 1 and, consequently,

  quent, actuating the release arm 10. That nut

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  2 is worn or that the safety nut 3 is subjected to friction, and therefore exposed to a risk of wear, the cable

  Safety 4 is released. To avoid, to the extent possible

  ble, that the safety nut 3 is prevented from turning when the body 1 and its nut 2 worn fall or slide down to come into contact with said nut 3, a low friction thrust transfer device, for example a polytetrafluoroethylene ring, a self-lubricating material or a thrust ball bearing or roller bearing can be mounted in the body 1, in the space between the lifting nut 2 and the safety nut 3. This device thrust transfer

  only operates when lifting nut 2 is worn.

  In elevating devices having no safety cable, or whose safety cable 4 is not intended to be disengaged from the body 1, the release mechanism proposed by the present invention may also be used, since the displacement of the 9 penetrating dowel pin

  in the body 1 can be used to actuate an indi-

  vidual, for example a micro-switch, allowing

  interrupt the power supply of the energy source or

  manual actuator, to feed a mechanism

  alarm and / or to activate or trigger other

  nisms. Figure 3 is a fragmentary radial section

  of the recess 7 of the safety nut 3, the latter presents

  as a different embodiment of that of Figure 1. The ramp 8 has a softer transition zone

  towards the extreme lateral face of the nut 3.

  FIG. 4 illustrates a lifting device which, according to the invention, is intended to lift cars and comprises two uprights 16, inside each of which is a threaded shaft cooperating with a body housing a lifting nut 2 and a safety nut 3. In each of the uprights 16, the body 1 is normally mechanically connected to the body 1 included in the other upright 16, via pins, gables and chains; relative to the device for controlling or protecting the wear of the lifting nut 2 and / or the safety nut 3,

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  these bodies 1 are connected via the safety cable 4. FIG. 5 shows an alternative embodiment of the body 1 of FIG. 1, in which one end of the release arm 10 is modified. In this case, the angle 12 is added to the shaft 10 or is an integral part

  of the last. Therefore, this bracket 10 is not deformed

  when the cable 4 is clear of the body-1.

  Instead of allowing clearance of the safety cable 4, the displacement of the safety nut 3 can be used to cut or shear this cable 4 when equipped with lifting devices. This shear may be provided by a blade, secured for example to the release pin 9,

  or by a sharp edge of the safety nut 3 when

  that the cable 4 passes through a hole formed in the wall of the body 1, so that this edge cuts off said cable 4

  during vertical and / or angular displacement of said nut 3.

  The invention therefore proposes a lifting device,

  particular for motor vehicles, in which the movement

  elevation is provided by a lifting nut 2, located inside a body 1, and moved upwardly or downwardly together with said body 1 inside a post 16, by means of a threaded shaft, during rotation of the latter engaged with said nut 2. A control or safety cable 4 is fixed to the body 1 housing the nut 2, and a safety nut 3, also housed in said body 1 at a distance below the lifting nut 2, is

  engaged with the thread of the shaft and moves vertically

  along the longitudinal axis of said body 1. The fastening means of the safety cable 4 is arranged in such a way that a displacement of the safety nut 3 with respect to the body 1 causes the movement of a safety mechanism. release, which, in turn, releases the fastening means, thus releases said safety cable 4 of said body 1, the displacement of said nut 3 relative to said body 1 taking place longitudinally the

  long and / or around the axis of this body 1. The release pin-

  9 is intended to release a safety cable 4 normally attached to the body 1, and / or to actuate a detector, such as a microswitch, interrupting the power supply or stopping the manual actuation mechanism of the elevator device . The safety nut 3 moves longitudinally

  or angularly inside the body 1.

  It goes without saying that many modifications can be made to the device described and shown without

depart from the scope of the invention.

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Claims (7)

  1. Lift device, especially for motor vehicles, wherein the lifting movement is provided by a lifting nut (2) housed inside a body (1) and movable upwards or downwards at the same time. time that said body (1) inside a post (16), by means of a shaft threaded during the rotation thereof with respect to said nut (2), a cable (4) control or safety device being fixed to said body (1) housing said nut (2), a safety nut (3) being furthermore also housed in said body (1), at a   certain distance below said lifting nut (2), in   with the threading of said shaft and mobile with respect to said   body (1) along the longitudinal axis of the latter,   characterized in that the securing means of said safety cable (4) is arranged such that a displacement of said safety nut (3) with respect to said body (1) causes the   movement of a release mechanism which, in turn,   ge said fixing means and thus said cable (4) of said body (1), and in that the displacement of said safety nut (3) relative to said body (1) takes place longitudinally, along and   optionally or alternatively around the axis of this body (1).   2. Lift device according to claim 1, characterized in that the fixing device comprises a stud (6) fixed perpendicular to the outer face of the   body wall (1) and a longitudinally movable lug (5).   at the outer end of said bolt (6) and in that the disengagement mechanism comprises a release bolt (9),   and a recess (7) occupying an extremely radial position   on the safety nut, said bolt (9) being longitudinally movable   dinalement in a hole drilled in the wall of said body (1), the inner end of this stud (9) abut against the bottom of the recess (7), while the outer end of this stud (9) is connected to a release arm (10) extending around said fixing pin (6) and in a space included between the pod (5) and the body (1).   3. Lift device according to one of the claims   1 and 2, characterized in that the release arm (10) is made of a deformable material, preferably elastic, one end of the safety cable (4) being fixed to the ring formed   by the lug (5), an angle (12) being fixed at one end   said arm (10) or said body (1) near the stud   (6), so as to maintain said lug (5) on said gou-   jon (6), at least when said arm (10) is in lateral contact with said body (1), said bracket (12) being in   a deformable material when attached to said body (1).   4. Lift device according to one of the claims   1 and 2, characterized in that the safety cable (4)   the release mechanism and the fixing means are replaced   placed by a detector identifying the longitudinal displacement and possibly or as an angular variant of the nut of   safety (3) relative to the body (1).   Elevating device according to claim 4, characterized in that the detector consists of a means of   release intended to allow a release movement.   6. Lift device according to any one of   Claims 1 to 5, characterized in that the mechanism of   release is designed to release the safety cable   (4) of the body (1), and optionally or alternatively, action-   a control device mounted on said body (1) when   that friction hinders the movement of the safety nut   (3) relative to the body (1) increases to reach or de- pass a predetermined value.   7. Lift device according to any one   Claims Z to 6, characterized in that the recess   (7) has two oblique or curved lateral ramps (14, 15)   vilins, extending in the peripheral direction of the safety nut (3), and in that the nut (3) is supported in the body (1) so that it can easily rotate by an angle corresponding substantially to the circumferential width   of the recess (7), the two lateral ramps (14, 15) extend   in the peripheral direction of said body (1) or said nut safety (3).