FR2890599A1 - Wheel fork locking and releasing device for trolley stretcher, has appendage entering in housing of mobile element when zero degree angular position is attained, and control unit permitting to set indexation unit in and out of operation - Google Patents

Abstract

The device has an indexation unit (Mi) for locking a fork (18) with respect to a leg (11) according to predefined orientation. The unit has a locking part situated, in a determined position, on one of two parts constituted by a lower end (11b) of the leg and fork, and another locking unit situated on another part. The unit has a mobile element guided with respect to the leg. An appendage enters in a housing of a mobile element when a zero degree angular position is attained. A control unit (Mc) permits to set in operation and out of operation the indexation unit.

Description

2890599 1

  DEVICE FOR LOCKING / RELEASING AN ORIENTABLE WHEEL CAP AND STACKING TROLLEY EQUIPPED WITH SUCH A DEVICE.

  The present invention relates to a device for blocking / releasing a steerable yoke in which is installed a wheel of substantially horizontal axis, the yoke being pivotally mounted about a substantially vertical axis at the lower end of the yoke. a leg participating in the support of a device. The invention relates more particularly but not exclusively to such a device for stretcher trolley.

  Trolleys comprising such steerable clevises have many applications. The front and / or rear wheels of some carriages are pivotally mounted so that they can be oriented in the direction of movement of the carriage.

  Stretcher trolleys supporting a patient are subjected to incessant maneuvers in relatively narrow hospital corridors, with right-angle turns. It is necessary to be able to bring these trolleys in different places such as the patient's room, the radiology department, the emergency room with the narrow boxes of care and around an ambulance. The total mass of the carriage and a patient to move up to 200kg, such maneuvers require swivel front or rear wheel clevis 360.

  For straight-line traffic in long corridors, it is difficult to drive the truck correctly with swiveling front fork clevises. In addition, for the loading of the carriage in an ambulance, in particular along an inclined plane of a raceway placed in the ambulance, operations are made difficult with pivoting rear wheel clevises.

  It thus appears that in certain cases it is desirable that the front and / or rear wheels of the carriages are pivotable and that in other cases this possibility of pivoting should be eliminated. But in the case of trolleys mounted on retractable crutches, such as stretcher trolleys, the establishment of a device and a command to lock / release swivel fork clevises is made difficult because of the configuration change of the different elements involved during the retraction of the crutches.

  The object of the invention is, above all, to propose a device for blocking / releasing an adjustable wheel clevis for blocking or releasing the wheel screed by a control that is easily accessible to the user. Advantageously said control should be disengageable so as not to hinder the retraction of the crutches of the carriage.

  According to the invention a device for blocking / releasing a steerable yoke in which is installed a wheel, of substantially horizontal axis, the yoke being pivotally mounted about a substantially vertical axis at the lower end of a leg participating in the support of a device is characterized in that it comprises an indexing means for locking the yoke relative to the leg in a predefined orientation, the indexing means comprising a first locking member located in a determined position on one of the two parts constituted by the lower end of the leg and the yoke, and a second complementary locking member located on the other part, biased by elastic means, one of the two members comprising a own appendix to enter a housing on the other member when the determined angular position is reached, and in that control means are provided to allow the mid in service or out of service indexing means.

  The determined blocking position may correspond to an angle of 0 with the longitudinal direction of the apparatus, or displacement in a straight line.

  The indexing means may comprise a movable element, guided relative to the lower end of the leg, the elastic means being interposed between the movable element and a support integral with the leg. The movable element can be guided in translation relative to the leg.

  The lower end of the movable element may comprise the vertical axis housing, so as to cooperate with the vertical axis appendix, integral with the yoke. The housing can be located in a projecting frustoconical surface.

  The appendix can be cylindrical.

  The upper end of the leg can be pivotally mounted about a horizontal axis on a slide placed on the frame so that it can be locked or moved in the longitudinal direction of the frame, and the control means can comprise linked means. to the frame, means connected to the slider and automatic connection / disconnection means between the frame-related means and those connected to the slider, the assembly being such that the connection is ensured when the slider occupies the position corresponding to the leg in position high, while the disconnection allows the movement of the slider.

  The control means connected to the frame may comprise at least one fork provided with a slot parallel to the direction of movement of the slider and open at one end, while the control means connected to the slider may comprise a pulling cable of the locking member provided at the lower end of the leg, this cable being provided at its end remote from the yoke, a stud having a head, and the automatic connection / disconnection means comprise the slot of the fork, the stud and the head under which the fork engages when the slider occupies an extreme position corresponding to the upper position of the leg, the stud being able to leave the slot of the fork when the slider moves for the lowering of the leg, the fork being mounted movably so as to exert traction on the stud when engaged in the range.

  The fork can be fixed on and perpendicular to a cross member pivotable about a substantially horizontal axis and perpendicular to the direction of movement of the slider, the rotation of the cross member and the fork causing the displacement of the locking member . The crossbar may consist of a profile.

  The control means may comprise two forks for locking / releasing the adjustable yokes of the two legs of a crutch.

  The rotation of the crossbar may be caused by the traction of cables whose ends are fixed substantially to the periphery of the crossbar.

  The cables can be pulled / released by means of a single zipper sliding in a tab integral with the frame and can be immobilized relative to the frame by a locking handle.

  Other features and advantages of the invention will appear in the following description of an embodiment with reference to the accompanying drawings but which has no limiting character.

  In these drawings: 1 is a perspective view of a carriage according to the invention. 2 is a perspective view on a larger scale of control means installed on the carriage of FIG. 1.

  Fig. 3 is a section along a vertical longitudinal plane of a detail of the control means of FIG. 2.

  Fig. 4 is a section along a vertical longitudinal plane of another detail of the control means of FIG. 2.

  Fig. 5 is a partial vertical section on a larger scale of a device according to the invention in clevis position locked in rotation.

  Fig. 6 is a side view with truncated portions of the device.

  Fig. 7 is seen from above with respect to FIG. 6 with truncated parts.

  Fig.8, finally, is a partial schematic side view of the loading of a carriage in an ambulance.

  Referring to FIG. 1 and FIG. 2, there can be seen a stretcher carriage C comprising a frame 10 supported by a front stand BI and a rear stand B2. The frame 10 is provided to receive a stretcher and comprises means not shown for fixing the stretcher. Each leg has two legs 11 spaced transversely. The legs 11 are extended by wheels 12 installed in clevises 18. For the rest of this description, the terms top, bottom, top and bottom must be understood for a carriage whose legs 11 are unfolded, its steerable wheels 12 being in position. contact with the ground.

  The legs 11 have an upper end 11a and a lower end 11b. The upper end 11a has a transverse orifice 11c which makes it possible to make a pivotal connection with a slider 13. The slider 13 is substantially U-shaped upside down with a central portion 13a horizontal and two tabs 13b extend perpendicularly downwards to the ends of the part 13a. The tabs 13b receive an axis passing through the orifices 11c for the articulation of the legs 11. The surfaces of the tabs 13b oriented towards the outside comprise non-visible free rollers in rotation, engaged in a section secured to the frame 10 so as to guide the slide 13 relative to the frame 10. The slide 13 can thus translate along the longitudinal axis of the frame 10. Locking means / translational release of the slide 13 are provided, but not shown.

  The legs 11 of the same stand are connected in pairs, substantially mid-length, by a transverse bar 14. A strut 15, preferably of constant length, articulated at each end, connects the transverse bar 14 to a platinum 16, immobilized relative to the frame 10.

  Two rollers R are provided at the front end of the carriage to facilitate loading into an ambulance.

  Referring to FIG. 5 to 7, it can be seen that the yoke 18, of each wheel of the front stand BI, is pivotally mounted according to a substantially vertical geometric axis 18a at the lower end Il b of a leg Il, via a tray 18d. The branches 18b and 18c of the yoke extend downwards on either side of the wheel 12 whose axis of rotation 12a is received in orifices provided towards the lower end of the branches. The portion of the yoke lying substantially above the axis 12a of the wheel 12 is pierced with an orifice 19.

  The leg 11 generally has a tubular profiled structure whose inner recess is used to secure the leg 11 with a part having a complementary profile and constituting the lower end 11b. The lower end 11b can also be in one piece with the leg 11.

  A finger 17 of geometric axis 17a, having a chamfered upper end, is mounted in the orifice 19 and forms an appendage 20. Above the finger 17, a movable member 21 is slidably mounted in a tube 22 secured to the lower end 11 b. The tube 22 comprises a cylindrical guide bore 22a of geometric axis 22b. The geometric axes 17a, 18a and 22b are parallel to each other. The movable element 21 comprises a substantially cylindrical peripheral surface 21a intended to cooperate with the guide bore 22a.

  The lower end 21b of the movable member 21 is frustoconical and comprises a substantially cylindrical coaxial housing 23. The upper end 21c of the movable element 21 comprises a fastening device 24 for a cable 25. Above the movable element 21, a washer 26 is blocked, coaxially inside the bore of guidance 22a. The washer 26 has a through hole 26a through which the cable 25. Between the washer 26 and the movable member 21, an elastic member 27, preferably constituted by a coil spring 28 is interposed.

  As can be seen in particular in FIG. 2, the cable 25 is guided in a sheath 25a to the upper end 11a of the legs 11. The cable 25 passes through the portion of the central portion 13a of the slider 13 through a light 13d. A stud 29, with a head 29a, is secured to the upper end of the cable 25 and is above the central portion 13a.

  A cross member 30 is pivotally mounted along a transverse axis 30a transverse to the frame 10. A fork 31 is integral with the cross member 30. It extends perpendicular to the axis of rotation 30a of the cross member 30 and has a longitudinal slot 31a whose end remote from 30a is open. The slot 31a is used to engage the fork 31 around the cable 25, under the head 29a whose diameter is greater than the width of the slot 31a.

  First ends 32a of cables 32 are fixed to the cross member 30 transversely to the axis 30a. The cross member 30 may be formed by a T-section 33, a detail of which is shown in FIG. 3.

  The second ends 32b of the cables 32, visible in particular FIG. 4, are joined, pass through a guide sleeve 34 and are fixed to a pull tab 35. The pull tab 35 is mounted in a bore provided in a tab secured to the frame 10 so as to be able to slide in the longitudinal direction of the frame 10. Its inner end located inside the frame 10, is provided with a flange 35a. A return spring 36 is interposed between the flange 35a and the frame 10. A locking lever 37, pivotally mounted in the lug secured to the frame 10, can be brought into contact with the pull tab 35 in order to block it by wedging.

  The operation of the device is as follows.

  When the pull tab 35 is released, the movable member 21 is pushed by the spring 28 to a low position defined by reciprocal abutments provided in the tube 22 and on the element 21. A game j1 remains between the yoke 18 and the movable member 21 so as to avoid friction when the yoke rotates about the geometric axis 18a.

  If the finger 17 acting as appendix 20 is out of the housing 23, the yoke 18 and the associated wheel 12 are freely adjustable around the axis 18a.

  When the finger 17 comes into contact with the lower end 21b of the movable member 21, the bevel of the finger 17 cooperates with the frustoconical surface of the end 21b to push the movable member 21 upwards, compressing the spring 28 .

  If the movement continues until the finger 17 is coaxial with the housing 23, the finger 17 sinks into the housing 23 under the action of the spring 28, securing the yoke 18 and the lower end 11a and preventing any rotation of the yoke 18 around the axis 18a. The yokes guiding the front wheels of the carriage are then locked in the longitudinal direction of the carriage, in the 0 position, which facilitates the movement in a straight line. The rear wheels remain pivoting to facilitate changes of direction.

  To release the clevises 18 of the stand B1, the operator pulls the pull tab 35 which compresses the return spring 36 and pulls the cables 32. Under the action of the cables 32, the crossbar 30 pivots about the axis geometric 30a and tilts the fork 31 upwards. The traction direction of the cables 32 does not cut the axis of rotation 30a of the cross member 30 so as to effectively cause the rotation thereof. The pull tab 35 can be locked in the retracted position by the lever 37.

  The fork 31 lifts the head 29a and the stud 29 pulls the cable 25. The movable element 21 is driven upwards under the action of the cable 25 and compresses the spring 28. The finger 17 leaves the housing 23 and releases the clevis 18 in rotation relative to the axis 18a. It should be noted that the stroke of the movable element 21 is sufficient to allow the finger 17 to leave the housing 23.

  If the operator releases the pull tab 35, and releases it, the cross member 30 and the fork 31 switch to their initial positions. The spring 28 causes the lowering of the movable member 21 and pulls the cable 25. The stud 29 descends under the action of the cable 25. The yoke 18 can be locked again.

  A translation of the slider 13, to the left of FIG. 2, in particular for the retraction of the legs 11 is possible because the stud 29 can leave the slot 31a. The control of the release / blocking of the yoke 18 is then no longer active, which is not a problem in this configuration of the stretcher lowered.

  Fig. 8 schematically illustrates the loading of a stretcher trolley into an ambulance M whose floor 38 is at a level slightly higher than that of the boarding wheels R.

  Under these conditions, the stretcher to facilitate the engagement of the rollers R on the floor 38 will exert not only a horizontal thrust on the carriage C to approach the rear of the floor, but also a vertical downward force V to cause a lifting of the front of the carriage and boarding wheels R to bring them to the floor 38.

  If the rear wheels of the carriage C are pivoting, a downward pressure on the rear of the truck is dangerous because the truck can run in an uncontrolled manner.

  Thanks to the invention, the stretcher holder can lock in position 0 30 the clevises of the rear wheels and ensure the boarding of the truck in good conditions of safety.

  The explanations provided about the loading of the truck on the floor of the horizontal ambulance 38 remain valid when the truck must be loaded on a rolling path inclined from the front to the rear, provided for example on an emergency table fixed on the floor of the ambulance. The trolley maneuvers could be prevented or considerably hampered by a more or less open position of the wheel treads with respect to the longitudinal axis of the trolley. Only a locking position at 0 rear clevises allows or promotes the truck loading maneuver in the ambulance.

  Other embodiments are possible. In particular, in place of an erasure of the movable member 21 by translation relative to the tube 22, it would be possible to provide a rotation of a movable member about a horizontal axis.

  Moreover one can also reverse the assembly of the appendix or finger and the movable element.

  In the example considered, the rotatable clevises 18 which can be locked in rotation were provided on the legs of the front stand BI. Similar screeds may be provided on the rear legs of the trolley.

  The invention can also be applied to a trolley or rolling apparatus supported only by three wheels, for example two rear wheels and a median front wheel. A steerable yoke which can be locked in rotation could be provided on the single front wheel.

  When the carriage is to be used while traveling on a surface, it is preferable that the front wheel clevises are locked in position 0, while the rear wheel clevises are pivotable, which makes it possible to guide the carriage in a straight line, and to make turns in good conditions. The invention makes it possible to satisfy all these requirements.

Claims (15)

  1. Device for blocking / releasing a stepless yoke (18) in which is installed a wheel (12) of substantially horizontal axis, the yoke (18) being pivotally mounted about a substantially vertical axis to the l lower end (11b) of a leg (11) participating in the support of an apparatus, characterized in that it comprises an indexing means (Mi) for locking the clevis (18) relative to the leg (11) according to a predefined orientation, the indexing means (Mi) comprising a first locking member (Mbl) located at a determined position on one of the two pieces constituted by the lower end (11b) of the leg and the yoke (18), and a complementary second blocking member (Mb2) located on the other part, biased by elastic means (Me), one of the two members having an appendage (20) adapted to fit into a housing (23) located on the other member when the determined angular position is reached, and e Control means (Mc) are provided for enabling the indexing means (Mi) to be put into operation or out of service.   2. Device according to claim 1, characterized in that the determined blocking position 20 corresponds to an angle of 0 with the longitudinal direction of the device, or displacement in a straight line.   3. Device according to claim 1, characterized in that the indexing means (Mi) comprise a movable element (21), guided relative to the lower end of the leg (11b), the elastic means (Me) being interposed between the movable element (21) and a support (26) secured to the leg (11).   4. Device according to claim 3, characterized in that the movable member (21) is guided in translation relative to the leg (11).   5. Device according to claim 3, characterized in that the lower end (21b) of the movable member (21) comprises the housing (23) of vertical axis, so as to cooperate with the appendix (20) d vertical axis, secured to the yoke (18).   6. Device according to claim 5, characterized in that the housing (23) is in a projecting frustoconical surface.   7. Device according to claim 5 or 6, characterized in that the appendix (20) is of cylindrical shape.   8. Stretcher trolley comprising a frame (10) supported by legs (11) for receiving a stretcher, characterized in that at least one of the legs (11) is equipped with a device according to one of the preceding claims.   9. stretcher trolley according to claim 8, characterized in that the upper end (11a) of the leg (11) is pivotally mounted about a horizontal axis on a slider (13) placed on the frame (10) so able to be blocked or displaced in the longitudinal direction of this frame (10), and that the control means (Mc) comprise means (30, 31) connected to the frame (10), means (25, 29) connected to the slider (13) and automatic connection / disconnection means (31, 31a, 29, 29a) between the means connected to the frame and those connected to the slider, the assembly being such that the connection is ensured when the slider occupies the corresponding position in the upper leg, while the disconnection allows the movement of the slide.   10. stretcher trolley according to claim 9, characterized in that the control means connected to the frame comprise at least one fork (31) provided with a slot (31a) parallel to the direction of movement of the slide and open at one end, while the control means connected to the slider comprise a traction cable (25) of the locking member provided at the lower end (11b) of the leg (11), this cable (25) being provided, at its remote end of the yoke (18), a stud (29) having a head (29a), and the automatic connection / disconnection means comprise the slot (31a) of the fork (31), the stud (29) and the head (29a) under which the fork (31) engages when the slider (13) occupies an extreme position corresponding to the upper position of the leg (11), the stud (29) being able to exit the slot (31a) of the fork (31) when the slider (13) moves for the lowering of the leg (11), the fork (31) is mounted movably so as to exert traction on the stud (29) when engaged in the fork (31).   11. stretcher trolley according to claim 10, characterized in that the fork (31) is fixed on and perpendicular to a cross member (30) pivotable about a substantially horizontal axis (30a) and perpendicular to the direction of travel the slider (13), the rotation of the cross member (30) and the fork (31) causing the displacement of the appendage (20).   12. Stretcher trolley according to claim 11, characterized in that the cross member (30) is a profile (33) 13. Stretcher trolley according to one of claims 9 to 12 supported by two legs (BI, B2) each having two legs, characterized in that the control means comprise two forks (31) for locking / releasing the adjustable yokes of two legs of a crutch.   14. stretcher trolley according to claim 14, characterized in that the rotation of the cross member (30) is caused by the traction of cables (32) whose ends are fixed substantially to the periphery of the cross member (30).   15. stretcher trolley according to claim 14, characterized in that the cables (32) are pulled / released by means of a single zipper (35) sliding in a tab integral with the frame (10) and can be immobilized relative to the frame (10) by a locking lever (37).