FR2863574A1 - Hand truck for e.g. lifting load e.g. box, has chassis and shell including respective stops that support each other, to integrate shell and chassis, and prevent rotation and movement of chassis towards front - Google Patents

Abstract

The hand truck has a chassis provided with a fastening unit (41) for fastening a load e.g. box. The chassis rotates between a laid load position and a carried load position. The chassis and a shell have respective stops (75, 74) that support each other, to integrate the shell and the chassis, and prevent rotation and movement of the chassis towards the front. The load is suspended at the locking unit (41), in the carried load position. The load is engaged in the fastening unit and rest on ground, in the laid load position.

Description

ARM CARRIAGE,

  The present invention relates to an arm carriage provided with a frame extended by a rear handling arm and carried by front wheels of axis A, this arm carriage also being provided with means for attaching a load intended for the carrying, the chassis being arranged to be pivotable with respect to said axis A between at least one position "load posed" in which the load is only engaged in said attachment means and rests on the ground and a position "load range" in which the load is suspended from the attachment means.

  In known manner, the arm carriages, for example pendulum load, allow through means of attachment, lift a load, move and then rest. The publication FR-A-2,745,255 notably describes a carriage with an arm whose load, when it is suspended from the hooking means, pivots freely so that, according to the inclination of the chassis, the vertical passing through the center of gravity of the load is automatically aligned with the attachment means. In addition to the effort required for its propulsion, this trolley with pendular load has the disadvantage of requiring a permanent effort to maintain the chassis in balance.

  In order to overcome this drawback, the French patent application FR-A02 / 15622 discloses an arm carriage comprising means for moving the load allowing, when the carriage arm moves from its "load posed" position to its "load position" ", to bring the vertical passing through the center of gravity of the load of the axis A wheels in a position of" balance ". This arm carriage thus facilitates the lifting of a load by making possible this equilibrium position in which the efforts to maintain the load in balance are almost zero.

  However, because of the movement of the hand truck on the ground and the mobility of the hand holding the arm of the hand truck, the equilibrium position is rarely rigorously reached and the vertical passing through the center of gravity of the load is shifted either forward or backward of this equilibrium position. Thus, the load tends to tilt the carriage arm respectively forward or backward. This phenomenon has little effect when the hand truck is used by a caring person. Nevertheless, when the hand truck is handled for example by a child or a person not very vigilant, this phenomenon can be very dangerous. Indeed, inadvertent lifting of the handling arm, sufficient to return the center of gravity of the load in front of the wheel axis, has the effect of driving the chassis pivoting forward. Because of the equilibrium position limiting the efforts to keep the carriage with the load carrying arm, this untimely lifting requires very little physical effort and can easily be done inadvertently. Depending on the kinetic energy stored by the frame, this pivoting may be particularly violent when the load and / or the pivoting stroke are important. In addition, when the load reaches the ground, the frame tends to disconnect unexpectedly from the load and to continue its pivoting and moving forward. There is then a significant risk of injuring the user of the handcart or a person in his immediate environment. This solution is therefore not satisfactory.

  The present invention aims to overcome these disadvantages by providing a carriage arm, simple to make and use, inexpensive to manufacture and to increase the safety of users or people in its immediate environment.

  For this purpose, the invention relates to an arm carriage of the kind indicated in the preamble, characterized in that it comprises locking means arranged for, at least from a predetermined position, coupling the frame to the load in order to limit pivoting and moving the chassis forward when the chassis is driven past the "load posed" position by the load.

  The locking means advantageously comprise at least one first connecting element provided on the load and at least one second connecting element provided on the frame, these connecting elements respectively comprising locking surfaces arranged to come into contact with one another. from the predetermined position and limit the pivoting and relative movement of the chassis with respect to the load.

  According to a preferred embodiment, at least one of the first and / or second connecting elements is movably mounted respectively with respect to the load and / or the frame carrying it.

  Advantageously, the frame comprises at least one locking hook pivotally mounted on a lower area of the frame to be actuable by the user's foot and defining the first connecting element and the load comprises a box provided with at least one ring defining the second connecting element.

  The chassis advantageously comprises at least one foot located in the extension of the handling arm and arranged to rest the frame in support of the ground, this foot being pivotally mounted relative to the frame and arranged to actuate the locking hook.

  The load is preferably provided with gripping lugs extending laterally and intended to be carried by the attachment means, the attachment means and the gripping lugs respectively defining the first and second connecting elements.

  According to an advantageous embodiment, the fastening means comprise V-grooves integral with the frame, each gripping lug has a substantially rectilinear shape housed in the groove in which it pivots, each gripping lug having at least one flat and being arranged to support by its flat on one of the branches of the V of the groove from the predetermined position.

  According to another advantageous embodiment, the hooking means comprise slides each provided with at least one locking zone, each gripping lug has a substantially circular section allowing its pivoting in the slide and at least one eccentric zone arranged to come pressing on the blocking zone from the predetermined position.

  The eccentric zone may be chosen from the group comprising at least one cam, a flat part.

  According to another advantageous embodiment the attachment means comprise slides, each gripping lug having a substantially circular section allowing its pivoting and its movement in the slide. In this case, the frame may comprise first stops and the load may comprise second stops arranged to bear on the first stops in said predetermined position, the slides having a length arranged so that, in this predetermined position, the ears of gripping are always guided in the slides, the gripping lugs and the first stops defining the first connecting elements, the slides and the second stops defining the second connecting elements of the locking means.

  The slides may each be provided with at least one through orifice and with a retractable locking rod intended to be housed in the through orifice and arranged to limit the movement of the gripping lugs in the slideways.

  The slides may be provided with notches arranged to prevent the longitudinal displacement of the gripping ears.

  According to yet another embodiment, the attachment means comprise substantially circular bearings provided with at least one opening opening, each gripping lug has a substantially circular section intended to be guided in rotation by the bearing and a through orifice, the locking means comprise at least one retractable locking rod intended to be housed respectively in the through hole and in the opening opening for connecting the bearings to the gripping lugs from the predetermined position.

  The bearings may each be provided with a retractable closure element arranged to prevent unintentional exit of the gripping ears of the bearings.

  The locking rod or the retractable closure element are advantageously coupled to control means accessible at the free end of the handling arm.

  The present invention and its advantages will become more apparent in the following description of several embodiments with reference to the accompanying drawings given by way of non-limiting example, in which: FIGS. 1A and 1B are perspective views of an arm carriage in the "load-on" and "load-bearing" positions resting on its foot, FIGS. 2A and 2B are perspective views of a first embodiment of the locking means of the arm carriage according to the invention respectively in position " loaded load "and" load bearing ", Figure 2B being an enlargement of detail B of Figure 2A, Figures 3 and 4 are perspective detail views of other embodiments of the arm carriage locking means according to 5A-C are perspective views of yet another embodiment of the arm carriage locking means according to the invention shown in an "unlocked" state and a state " Fig. 6C being an enlargement of the detail C of Fig. 6B, and Figs. 6A and 6B are perspective views of another embodiment of the locking means of the arm carriage according to the invention respectively in position. "load carried" and "loaded load", Figure 6B being an enlargement of detail C of Figure 6A.

  In known manner, and with reference to FIGS. 1A and 1B, the carriage with arm 1 is provided with a frame 2 carrying a load 3. In the examples illustrated, this load is a box 3 able to receive any type of bulk content. , bag, pot, etc. This box 3 is provided with gripping lugs 30 extending laterally. It is understood that the load 3 may be quite different, for example bags carried by a bar, the ends of this bar defining the gripping ears.

  The frame 2 is extended by a handling arm 20 extending rearwardly and is provided with attachment means 40 for attaching the load 3, via the gripping lugs 30 to lift and transport it . The frame 2 is carried by wheels 21 of axis A around which it is free to pivot between at least one position "load posed" illustrated by Figure lA and a position "load" shown in Figure lB. In the "posed load" position, the load 3 rests on the ground. It can be engaged in the attachment means 40 but they do not wear it. In the "load-bearing" position, the load 3 is suspended from the attachment means 40 which carry it. The arm carriage 1 can then be held in balance by the user or placed in support, for example on a foot 22 provided in the extension of the handling arm 20.

  This carriage arm 1 has no means to prevent the frame 2 continues its pivoting and its forward movement beyond the "load posed" position and is transformed into mobile danger.

  According to the invention, the arm carriage 1 is substantially similar to the previous one. It differs in that it comprises locking means 50-54. These locking means 50-54 make it possible to limit the pivoting and the displacement of the frame 2 towards the front, from a predetermined position, when, after having passed from the "load-bearing" position to the "posed load" position. , the frame 2 tends to continue its pivoting forward beyond its "load posed" position.

  The locking means 50-54 comprise at least one first connecting element provided on the frame 2 and a second connecting element provided on the casing 3. These connecting elements comprise locking surfaces and are movable relative to each other. the other between an "unlocked" state and a "blocked" state. In the "unlocked" state, the locking surfaces are not in contact with each other and allow the relative movement of the connecting elements and therefore of the frame 2 relative to the box 3. In the "locked" state, the locking surfaces are in contact with one another and limit or even prevent relative movement of the connecting elements. In this "blocked" state, the chassis 2 is at least partially connected to the caisson 3 so that, when it tends to continue to pivot and move forward, it remains blocked by the caisson 3 resting on the ground .

  In the examples described, the box 3 is provided with gripping ears 30-34 extending laterally and carried by the attachment means 40-44 which allow their pivoting when the carriage arm 1 is in the position "load carried "or when in an intermediate position between the" load-on "and" laid-on "positions. The carriages 1 of these examples are therefore of the pendulum type since they allow self-alignment of the center of gravity of the load 3 with the vertical passing through the attachment means 40-44 so that the load 3 is permanently "vertical". The invention extends of course to non-pendular arm carriages. As described below, the locking means 50-54 are arranged to limit the pivoting and the forward displacement of the frame 2, from the predetermined position, when it tends to continue its forward motion the "posed" load position.

  According to a first embodiment represented by FIGS. 2A and 2B, the frame 2 comprises a stand 22, situated in the extension of the handling arm 20 on which it is pivotally mounted, for example via a pivot connection, d a ball joint, an elastic connection or any other equivalent connection. The foot 22 allows the chassis 2 to rest on the ground. This foot 22 includes a locking hook 60 defining the first connecting element of the locking means 50. The box 3 comprises a ring 61 defining the second connecting element of the locking means 50. When the locking hook 60 is engaged in the 61, the locking means 50 are in the "locked" state, the box 3 is connected to the frame 2. When the locking hook 60 is not engaged in the ring 61, the locking means 50 are in the "unlocked" state in which the box 3 is no longer linked to the frame 2 and can rotate freely relative to the attachment means 40, the frame 2 being free to swing forward.

  The foot 22 can be actuated by the user's foot towards the casing 3 to pass the locking means from the "locked" state to the "unlocked" state. The foot 22 is also coupled to return means (not shown), such as for example a spiral spring, an elastic link or any other suitable means. Thus, when the user of the arm carriage 1, after unlocking the locking means 50, stops its action on the foot 22, the return means bring it back to its initial position. The locking hook 60 can then again be coupled to the ring 61 automatically, either by pulling the box 3 towards the rear, or by swinging the frame 2 towards the rear to indirectly cause the pivoting of the box 3.

  When the locking hook 60 and the ring 61 are coupled, the box 3 is thus rigidly connected to the frame 2 in the "locked" state. Thus, when using the arm carriage 1, if the center of gravity of the load 3 passes in front of the axis A of the front wheels 21 and the handling arm 20 is not sufficiently stressed to maintain the frame 2 in equilibrium, under the effect of the weight of the load 3, the frame 2 tilts forward until the box 3 touches the ground and stops the pivoting of the frame 2 by means of the locking means 50 formed locking hook 60 and ring 61.

  According to an alternative embodiment not shown, the locking hook 60 is independent of the foot 22.

  According to another variant of embodiment not shown, the box 3 is connected to the foot 22 of the frame 2 by means of a removable locking element such as for example a pin, a screw or any suitable element.

  According to another variant of embodiment not shown, the connecting elements comprise at least one elastically deformable connecting element to allow its attachment and unhooking with the other connecting element by elastic deformation of the deformable connecting element.

  According to yet another variant embodiment not shown, the locking means comprise at least three connecting elements, at least one of which is retractable. This retractable connecting element can be arranged between the two other connecting elements to rigidly connect them and put them in the "locked" state. This retractable connecting element may be a pin, a screw, a stirrup, a ring, a hook, or any other suitable means.

  In the example illustrated in Figure 3, the gripping lugs 32 have a substantially circular section allowing their pivoting. The attachment means 42 comprise semicircular U-shaped bearings 90 provided on the frame 2. Each bearing 90 is provided with a retractable locking rod 80 passing therethrough through orifices (not shown) and intended to be housed in a through hole 320 in each gripping lug 32. In this example, the gripping lugs 32 comprise a central bore whose opposite walls are provided with an oblong hole defining the through hole 320. When the frame 2 carrying the casing 3 is inclined forward, the box 3 pivots around its gripping ears 32 so as to put the box 3 "vertical". The bearings 90, the gripping lugs 32 and the locking rod 80 define the locking means 52. Thus, if the frame 2 continues to pivot forwardly, the casing 3 lands on the ground and, from this position predetermined, the locking rod 80 bears on the edges of the through hole 320 which lock it in the "locked" state, preventing the frame 2 from continuing its pivoting and its forward movement beyond the position "posed load". The frame 2 remains secured to the casing 3. When the user wants to uncouple the casing 3 of the frame 2, he manually removes the locking rod 80 and leaves the gripping lugs 32 of the bearings 90. As in the previous example, the setting in place and the withdrawal of the locking rod 80 can be controlled remotely by control means accessible at the handle of the handling arm 20.

  In the example illustrated in FIG. 4, the gripping lugs 33 have a substantially rectilinear shape presenting two flats 330. The attachment means 43 comprise grooves 100 in V provided on the frame 2 in which the lugs can pivot between the flaps. two bars of V. The grooves 100 are partially closed to define an introduction zone gripping lugs 33 of limited dimensions. In this example and optionally, the introduction zone comprises a retractable closure element such as for example a locking rod 80 for closing it completely to prevent the unintentional exit of the gripping lugs 33. The grooves 100, the gripping lugs 33 and the locking rod 80 define the locking means 53. Thus, if the frame 2 continues its pivoting forward, from the predetermined position, the box 3 is placed on the ground and one of the flats 330 bears against one of the walls of the groove 100 which blocks it in the "locked" state, preventing the frame 2 from continuing to pivot forwardly. The locking rod 80 prevents the frame 2 from separating from the casing 3. The frame 2 thus remains integral with the casing 3. When the user wants to uncouple the casing 3 of the frame 2, he switches the frame 2 backwards, the flat 330 is no longer in contact with the wall of the groove 100, it can then manually remove the locking rod 80 and out the gripping lugs 33 grooves 100. As in the previous example, the introduction and the removal of the locking rod 80 can be controlled remotely by control means accessible at the handle of the handling arm 20.

  In the example illustrated by FIGS. 5A-C, the gripping lugs 34 have a substantially circular section allowing their pivoting. The attachment means 44 comprise slides 200 secured to the frame 2, in the shape of an elongated U and defining two branches, a lower branch 201 and an upper branch 202. These branches 201, 202 define a U-shaped guide zone in which the gripping lugs 34 move longitudinally along a predetermined stroke. For this purpose, the slides 200 each comprise, optionally, two sliding zones 210 connected by an inclined junction zone 211 forming a baffle (cf. FIG. 5B). The free end of the lower branch 201 of each slide 200 is raised to allow the easy introduction of the load. It also makes it possible to reduce the opening of the slideways 200. Moreover, each slideway 200 comprises a blocking zone 220 (see FIGS. 5B and 5C), provided substantially opposite the lower arm 201, and each ear of FIG. gripping 34 has an eccentric zone 340 (see Figures 5B and 5C), in this example a cam, inclined relative to the locking zone 220 when the frame 2 has a normal inclination. It is obvious that this configuration can be reversed, the blocking zone 220 can be provided on the lower branch 201 and the eccentric zone 340 be inclined relative to the lower branch 201.

  In normal reclining position of the frame 2, the box 3 being carried by the frame 2 as shown in Figure 5A, the gripping lugs 34 are freely pivoted in the slideways 200 to put the load "vertical". In this position, the eccentric zones 340 are not in contact with the locking zones 220. The grooves 200 and the gripping lugs 34 define the locking means 54. Thus, if the chassis 2 continues to pivot forwardly, from the predetermined position, the eccentric zones 340 come into contact with the blocking zones 220, as illustrated by FIGS. 5B and 5C. The slides 200 are then linked by wedging to the gripping lugs 34, the eccentric zones 340 being locked on the locking zones 220 making it impossible for the gripping lugs 34 to rotate relative to the slideways 200. The frame 2 and the casing 3 are connected. to each other in a "blocked" state preventing the frame 2 from continuing to pivot and move forward beyond the "load-on" position. When the user wants to decouple the box 3 of the frame 2, it switches the frame 2 backwards. This simple movement has the effect of eliminating the contact between the eccentric zones 340 and the locking zones 220 and to release the pivoting of the gripping lugs 34 in the slideways 200. This solution makes it possible to secure the use of the arm carriage without intervention. manually, locking and unlocking is done automatically.

  To increase the safety of this embodiment, each slide 200 may be provided with a retractable locking rod (not shown).

  According to an alternative embodiment not shown, this embodiment can also be adapted to fastening means comprising bearings in accordance with FIG. 5.

  Furthermore, the gripping lugs 34 may comprise a flat part defining the eccentric zone 340, and the attachment means 44 a bearing zone on which the flat surface bears in the "locked" state to limit the pivoting of said grasping ear. This support zone may be formed of a retractable locking rod mounted for example on the bearings.

  According to another embodiment illustrated in FIGS. 6A and 6B, the gripping lugs 31 have a substantially circular section and are pivotable in slideways 70, defining the hooking means 41. The slideways 70 have an elongated U shape and are integral with the frame 2. They define a guide zone on which the gripping lugs 31 can move longitudinally along a predetermined stroke. Each slideway 70 is provided with two notches 71 defining two predetermined positions for the gripping lugs 31, limiting their longitudinal displacement and making it possible to grip the casing 3 for raising the ground. In this example, each slide 70 optionally comprises a retractable locking rod 80 traversing the slideway 70 through through orifices 72 provided between the notches 71 and the opening of the slideway 70 to secure the gripping lugs 31 in the grooves. The slides 70 have a sufficient length allowing, when the chassis is in its predetermined position, that the gripping lugs 31 are always housed in the slideways 70.

  In addition, the frame 2 comprises first stops 75 and the box 3 comprises second stops 74. These stops 74, 75 are intended to bear, against each other, in the predetermined position, when the frame 2 continues its pivoting movement forward. Thus, the frame 2 can not continue its pivoting and its forward movement and remains attached to the box 3. The gripping lugs 31 and the first stops 75 define the first connecting elements, the slides 70 and said second stops 74 define the second connecting elements of the locking means 51. Thus, even when the chassis 2 tilts forward, it remains attached to the box 3 which blocks it in its pivoting and its forward movement, beyond its position "posed load". When the user wants to uncouple the box 3 of the frame 2, it tilts the frame 2 rearwardly to clear the gripping lugs 31 of the rails 70 having taken care to remove the locking rods 80.

  According to an alternative embodiment not shown, the introduction and removal of the optional locking rod 80 can be controlled remotely. The locking rod 80 may for example be coupled to control means accessible at the handle of the handling arm 20, such as for example a cable connected to a handle.

  In general, the aforementioned embodiments can be combined.

  The description makes it clear that the arm carriage 1 according to the invention makes it possible to meet the goals set and in particular that its locking means 50-54 considerably improve the safety of its use by allowing, when the chassis 2 has a tendency to go beyond the load position "posed" forward, to secure the box 3 to the frame 2 to stop the movement of the frame 2 forward.

  The present invention is not limited to the embodiments described but extends to any modification and variation obvious to a person skilled in the art while remaining within the scope of protection defined in the appended claims.

Claims (15)

claims   1. Hand truck (1) provided with a frame (2) extended by a rear handling arm (20) and carried by front wheels (21) of axis A, this arm carriage (1) also being provided fastening means (40-44) for a load (3) for carrying it, said frame (2) being arranged to be pivotable with respect to said axis A between at least one "posed load" position in which the load (3) is engaged only in said attachment means (40-44) and rests on the ground and a "load-bearing" position in which said load (3) is suspended from the attachment means (40-44), characterized in that it comprises locking means (50-54) arranged for, at least from a predetermined position, coupling said frame (2) to said load (3) in order to limit the pivoting and the displacement of the frame ( 2) forward when the latter is driven beyond said position "load posed" by said load (3).   2. Hand truck (1) according to claim 1, characterized in that said locking means (50-54) comprise at least a first connecting element provided on said load (3) and at least one second connecting element provided on said frame (2), said connecting elements respectively having locking surfaces arranged to come into contact with each other from said predetermined position and limit the pivoting and relative movement of said frame (2) with respect to said charge (3).   3. Hand truck (1) according to claim 2, characterized in that at least one of said first and / or second connecting elements is movably mounted respectively relative to said load (3) and / or said frame ( 2) wearing it.   4. Hand truck (1) according to claim 3, characterized in that said frame (2) comprises at least one locking hook (60) pivotally mounted relative to a lower region of said frame (2) to be actuable by the foot of the user and defining said first connecting element and in that said load comprises a box (3) provided with at least one ring (61) defining said second connecting element.   5. Hand truck (1) according to claim 4, characterized in that said frame (2) comprises at least one foot (22) located in the extension of said handling arm (20) and arranged to rest said frame (2) in support of the ground and in that said foot (22) is pivotally mounted relative to said frame (2) and arranged to actuate said locking hook (60).   6. Hand truck (1) according to claim 2, characterized in that said load (3) is provided with gripping lugs (30-34) extending laterally and intended to be carried by said hooking means ( 40-44), said hooking means (40-44) and said gripping lugs (30-34) respectively defining said first and second link members.   7. Hand truck (1) according to claim 6, characterized in that said hooking means (43) comprise grooves (100) V integral with said frame (2), in that each lug (33) has a substantially rectilinear shape housed in said groove (100) in which it pivots, each gripping lug (33) having at least one flat (330) and being arranged to abut by its flat on one of the branches of the V said groove (100) from said predetermined position.   8. Hand truck (1) according to claim 6, characterized in that said hooking means (44) comprise slides (200) each provided with at least one locking zone (220), in that each ear gripper (34) has a substantially circular section allowing its pivoting in said slide (200) and at least one eccentric zone (340) arranged to bear on said blocking zone (220) from said predetermined position.   9. Hand truck (1) according to claim 8, characterized in that said eccentric zone (340) is selected from the group comprising at least one cam, a flat.   10. Hand truck (1) according to claim 6, characterized in that said hooking means (41) comprise slides (70), in that each gripping lug (31) has a substantially circular section allowing its pivoting and its displacement in said slide (70), in that said frame (2) comprises first stops (75), in that said load (3) comprises second stops (74) arranged to bear on said first stops in said predetermined position, in that said slides (70) have a length arranged so that in said intermediate position, said gripping lugs (31) are always guided in said slides (70), said gripping lugs (31) and said first stops (75) defining said first connecting members, said slides (70) and said second stops (74) defining said second connecting elements of the locking means lage.   11. Hand truck (1) according to claim 8 or 10, characterized in that said slides (200, 70) are each provided with at least one through hole (72) and a locking rod (80) retractable intended to be housed in said through hole (72) and arranged to limit the movement of said gripping lugs (31, 34) in said rails (200, 70).   12. Hand truck (1) according to claim 8 or 10, characterized in that said slides (200, 70) are provided with notches (71) arranged to prevent the longitudinal displacement of said gripping lugs (34, 31).   13. Hand truck (1) according to claim 6, characterized in that said attachment means (42) comprise substantially circular bearings (90) provided with at least one opening opening, in that each gripping lug ( 32) has a substantially circular section intended to be guided in rotation by said bearing (90) and a through hole (320), in that said locking means (51) comprise at least one retractable locking rod (80) intended for being respectively housed in said through hole (320) and in said opening opening for connecting said bearings (90) to said gripping lugs (32) from said predetermined position.   14. Hand truck (1) according to claim 13, characterized in that said bearings (90) are each provided with a retractable closure member (80 ') arranged to prevent the unintentional exit of said gripping ears (32) of said bearings (90).   15. Hand truck (1) according to at least one of claims 11, 13 or 14, characterized in that said locking rod (80) or said closure element (80 ') are coupled to accessible control means at the free end of said handling arm (20).