Blocking device for a cylinder and handling machine with lifting arm comprising the blocking device

Abstract

The invention relates to a blocking device (20) for a lifting cylinder (6) and to a handling machine (1) with lifting arm (5). The blocking device (20) comprises two blocking elements (30, 40). The two blocking elements (30, 40) are configured to be assembled to one another in an assembled configuration in which the two blocking elements (30, 40) together delimit a central space through which the rod (62) of the lifting cylinder (6) passes. The blocking device (20) blocks a movement of the lifting arm (5) towards its lowered position.

Description

Locking device for a jack and lifting arm handling machine comprising the locking device

[0001] The invention relates to the field of lifting arm handling machines. More specifically, the invention relates to a lifting arm handling machine comprising a locking device for locking a movement of the lifting arm towards its lowered position. The invention further relates to a locking device for a cylinder. Technological background

[0002] For example, document WO 2021 / 170929 A1 discloses a handling machine comprising a lifting arm. The lifting arm is pivotally mounted on the frame of the handling machine about an axis of rotation, so as to be movable in a vertical plane between a lowered position and a raised position. The handling machine comprises a lifting cylinder articulated to the lifting arm to rotate the lifting arm. Summary

[0003] In such a handling machine, it may be desired to block a movement of the lifting arm towards its lowered position, for example to allow an operator to safely intervene on a part of the handling machine which is located below the lifting arm.

[0004] To achieve this blocking of the movement of the lifting arm towards its lowered position, it may be envisaged to arrange a blocking wedge on the lifting cylinder, the blocking wedge being made of a single U-shaped piece and having a predetermined length. When the retraction of the lifting cylinder decreases until it reaches the predetermined length, the blocking wedge abuts at one of its ends against the barrel of the lifting cylinder and at the other of its ends against the lifting arm, and thus prevents the retraction of the lifting cylinder below the predetermined length.

[0005] However, the inventors found that this solution was not entirely satisfactory.

[0006] In particular, the locking wedge can be large, to the point of making it difficult or very difficult to position it on the handling machine if it is small. However, it is crucial that the locking wedge can be fixed somewhere on the handling machine while remaining easily accessible.

[0007] Furthermore, being made of a single piece, the locking wedge has a significant mass which makes it difficult to position it on the lifting cylinder.

[0008] An idea underlying the invention is to provide a handling machine comprising a locking device for locking a movement of the lifting arm towards the lowered position, the locking device being easy to assemble and of limited dimensions.

[0009] According to a first object, the invention provides a locking device for a cylinder, the locking device comprising two locking elements, each locking element having a first end and a second end opposite the first end, wherein the two locking elements are configured to be assembled to each other in an assembled configuration in which the two locking elements together delimit a central space for a rod of the cylinder, wherein, in the assembled configuration, a distance between the first end and the second end of a locking element defines a minimum extension of the cylinder, said minimum extension of the cylinder being reached when a) the first end of each of the two locking elements abuts an end surface of a barrel of the cylinder in which the rod slides and b) the second end of each of the two locking elements abuts an articulation stirrup,the articulation stirrup receiving an articulation shaft, one end of the rod opposite the barrel being mounted articulated to the articulation shaft.,

[0010] According to a second object, the invention provides a handling machine comprising: - a chassis movable relative to the ground surface; - a lifting arm pivotally mounted on the chassis about an axis of rotation, so as to be movable between a lowered position and a raised position; - a lifting cylinder for pivoting the lifting arm, the lifting cylinder comprising: a barrel mounted articulated to one of the chassis and the lifting arm about a first articulation axis; and a rod slidably mounted in the barrel and mounted articulated to the other of the chassis and the lifting arm via a hinge shaft, the hinge shaft extending along a second articulation axis parallel to the first articulation axis and being received in a hinge bracket that the other of the chassis and the lifting arm has;and- a locking device for locking a movement of the lifting arm towards the lowered position,wherein the locking device comprises two locking elements, each locking element having a first end and a second end opposite the first end,wherein the two locking elements are configured to be assembled to each other in an assembled configuration in which the two locking elements together define a central space through which the rod passes,wherein, in the assembled configuration, the first end of each of the locking elements abuts an end surface of the barrel, and the second end of each of the two locking elements is configured to abut the hinge bracket so as to lock said movement of the lifting arm towards the lowered position.;

[0011] Thanks to these characteristics, the locking device can be easily produced by assembling the two locking elements together around the rod of the lifting cylinder. Furthermore, for a lifting cylinder of given dimensions, the two locking elements can be of smaller dimensions than a locking wedge consisting of a single U-shaped piece, which facilitates the positioning of the locking elements on the handling machine.

[0012] According to embodiments, such a handling machine may comprise one or more of the following characteristics.

[0013] According to one embodiment, the barrel is mounted articulated to the chassis around the first articulation axis, and the rod slidably mounted in the barrel is mounted articulated to the lifting arm via the articulation shaft, the articulation shaft extending along the second articulation axis.

[0014] According to one embodiment, the first articulation axis is parallel to the axis of rotation of the lifting arm.

[0015] According to one embodiment, the lifting arm is movable in a vertical plane.

[0016] According to one embodiment, the vertical plane is parallel to a longitudinal direction of the handling machine.

[0017] According to one embodiment, the two locking elements have a generally L-shaped cross-section.

[0018] According to one embodiment, each of the two locking elements comprises at least one tenon, said at least one tenon being intended to be received in a mortise which the other locking element comprises so as to produce the assembled configuration.

[0019] This makes assembling the locking device particularly easy and does not require any tools.

[0020] According to one embodiment, each of the two locking elements comprises three tenons, said three tenons comprising a retaining tenon, the retaining tenon having a through hole configured to receive a pin for maintaining the two locking elements in the assembled configuration.

[0021] According to one embodiment, each of the two blocking elements further comprises at least one light.

[0022] This makes it possible to lighten the two locking elements and therefore make it even easier to assemble the locking device.

[0023] According to one embodiment, at least one of the two locking elements comprises, at its second end, an attached plate configured to come into abutment against the articulation stirrup.

[0024] According to one embodiment, said attached plate is attached by welding.

[0025] According to one embodiment, the two blocking elements are identical.

[0026] This makes it easier to manufacture the locking device. In addition, the assembly of the locking device is made easier because the user is not required to distinguish between two locking elements that would be different.

[0027] According to one embodiment, each of the two locking elements is configured to be fixed to the frame.

[0028] According to one embodiment, the chassis comprises two side members extending parallel to each other, the lifting arm being pivotally mounted between the two side members.

[0029] According to one embodiment, the side members extend parallel to the longitudinal direction of the handling machine.

[0030] According to one embodiment, at least one of the locking elements, and preferably both locking elements, are configured to be secured to the frame at a space between the two side members, under the lifting arm when the lifting arm is in the lowered position.

[0031] Each of the characteristics presented above in relation to the handling machine according to the second object is also applicable to the locking device according to the first object.

[0032] The locking device according to the first object can be used for locking a lifting cylinder integrated into a handling machine or any other cylinder. Brief description of the figures

[0033] The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings.

[0034] This is a schematic representation of a handling machine in the form of a forklift.

[0035] This is a perspective view of a locking device for locking a movement of the forklift's lifting arm from its lowered position, the locking device being disassembled.

[0036] This is a perspective view of the locking device, about to be assembled on a lifting cylinder of the forklift.

[0037] This is a partial perspective view of the forklift's lifting cylinder and lifting arm, together with the assembled locking device.

[0038] This is a sectional view, perpendicular to the lifting cylinder, of the lifting cylinder together with the assembled locking device.

[0039] This is a partial front view of the forklift, showing an example of how the locking device elements are attached to the forklift chassis.

[0040] This is a partial perspective view showing in more detail the attachment shown in the.

[0041] By convention, the "longitudinal" direction of the handling machine corresponds to the front-to-rear orientation of the machine. Furthermore, the "transverse" direction is oriented perpendicular to the longitudinal direction. Furthermore, the "vertical" and "horizontal" directions are defined by reference to a handling machine positioned on a perfectly horizontal plane.

[0042] With reference to the, a handling machine 1 is described. The handling machine 1 comprises a movable chassis 2. To this end, the handling machine 1 comprises wheels 3 or tracks as well as a powertrain, not shown. The powertrain comprises a thermal or electric engine as well as a transmission device which couples said engine to the wheels 3 or to the tracks, which makes it possible to move the handling machine 1.

[0043] The handling machine 1 also comprises a driver's cab 4 which is carried by the chassis 2. The driver's cab 4 is equipped with a driver's station comprising a seat on which the driver can sit to drive the forklift. The driver's station also comprises equipment for controlling the handling machine 1, such as a steering wheel, an accelerator pedal, a brake pedal. The driver's station is also equipped with one or more actuating members which make it possible to control the movement of a lifting arm 5 and a tool 8 which is articulated thereon and which will be described in more detail later.

[0044] The lifting arm 5 is pivotally mounted on the frame 2 about an axis X1 which is preferably oriented horizontally and transversely. Thus, the lifting arm 5 is mounted movable in a vertical plane parallel to the longitudinal direction of the handling machine 1 between a lowered position, illustrated in the, and a raised position.

[0045] According to one embodiment, the lifting arm 5 is telescopic, that is to say its length is variable. To do this, the lifting arm 5 comprises at least two parts, one of which slides inside the other, and a telescoping cylinder, not shown, which comprises a first and a second end respectively fixed to the first and second parts of the lifting arm 5. In this case, the handling machine 1 may in particular be a telescopic forklift. According to another embodiment, the lifting arm 5 is an arm of fixed length.

[0046] The handling machine 1 also includes a lifting cylinder 6.

[0047] In a manner known per se, the lifting cylinder 6 comprises a barrel (also called a cylinder) 61 in which a rod (also called a piston) 62 is slidably mounted. The barrel 61 is mounted articulated, at one of its ends, on the chassis 2 of the handling machine 1 around an articulation axis X2 parallel to the axis X1. The rod 62 is mounted articulated, at its end opposite the barrel 61, on the lifting arm 5 around an articulation axis X3, also parallel to X1.

[0048] It is understood that the sliding of the rod 62 in the barrel 61 causes the lifting arm 5 to move from its lowered position illustrated in the to a raised position illustrated for example in the. The rod 62 can be actuated in any desired manner, for example hydraulically, pneumatically or electrically. Of course, the actuation of the rod 62 is controlled by the driver from the driving position, in a manner known per se.

[0049] Furthermore, in a manner known per se, the lifting arm 5 is also equipped with a tool 8, such as a bucket or a fork, which is intended to receive a load. The tool 8 is mounted articulated at the distal end of the lifting arm 5. In a manner known per se and not detailed here, the tool 8 can be mounted pivoting relative to the lifting arm 5.

[0050] When the lifting arm 5 is raised, it may be desired to block the movement of the lifting arm 5 towards its lowered position shown in the, for example to allow an operator to safely intervene on a part of the handling machine 1 which is located below the lifting arm 5. A blocking device 20 which is suitable for blocking the movement of the lifting arm 5 towards its lowered position will now be described with reference to FIGS. 2 to 7.

[0051] Referring firstly to the and to the, the locking device 20 comprises two locking elements respectively designated by the references 30 and 40.

[0052] The locking elements 30, 40 each comprise an elongated main body 31 having a generally L-shaped cross section. More precisely, the main body 31 comprises two elongated portions 31A, 31B, and the elongated portions 31A, 31B form a right angle with respect to each other so as to form the generally L-shaped cross section. In the example shown, the elongated portions 31A, 31B are connected to each other by a curved connecting portion 31C.

[0053] The elongated portion 31A comprises tenons 32, 33, 34, while the elongated portion 31B comprises mortises 35, 36, 37 shaped to receive the tenons 32, 33, 34 respectively. Thus, the locking elements 30, 40 can be assembled to each other so as to produce an assembled configuration, shown in la and la.

[0054] To hold the locking members 30, 40 in the assembled configuration, one of the tenons 32, 33, 34, and preferably the central tenon 33, is provided with a through hole 331. The through hole 331 is sized to receive a pin 70 which, when inserted into the through hole 331, holds the tenon 33 in place in the corresponding mortise 36.

[0055] In order to facilitate the manufacture of the locking device 20, the locking elements 30, 40 are preferably identical.

[0056] The locking elements 30, 40 may be made in any suitable manner, as long as they have sufficient mechanical strength to block the movement of the lifting arm 5 towards its lowered position as will be described later. In a particular example, the locking elements 30, 40 are made by extrusion and then machining of a suitable metal alloy.

[0057] To lighten the blocking elements 30, 40, the elongated portion 31A and / or the elongated portion 31B may independently comprise one or more slots 39.

[0058] Furthermore, it is preferred that at least one of the elongated portion 31A and the elongated portion 31B, and preferably both, has at one of its ends a plate 38. The plate 38 is attached to the elongated portion 31A or to the elongated portion 31B in any suitable manner, and more preferably by welding.

[0059] With reference to Figures 3 to 5, the use of the locking device 20 is now described.

[0060] First, the lifting arm 5 is lifted by means of the lifting cylinder 6, as previously described.

[0061] Then, the blocking elements 30, 40 are brought in and arranged around the rod 62, as shown in the figure.

[0062] Then, the locking elements 30, 40 are assembled by means of the tenons 32, 33, 34 and the mortises 35, 36, 37 so as to produce the assembled configuration of the locking device 20. In this assembled configuration, as shown in 1a and 1a, the locking elements 30, 40 together delimit a central space 400 of sufficient dimensions to allow the rod 62 of the lifting cylinder 6 to pass.

[0063] Finally, the pins 70 are inserted into the corresponding through holes 331 on the tenons 33, which maintains the locking device 20 in its assembled configuration.

[0064] It is understood that in the assembled configuration: - at one of their ends, the locking elements 30, 40 are in abutment against an end surface 61A (cf. and) of the barrel 61, - while at the other of their ends, the locking elements 30, 40 are likely to come into abutment against the articulation stirrup 50 of the lifting arm 5 (cf.). It is preferable, although not obligatory, that it is the ends which carry the added plates 38 which are arranged opposite the articulation stirrup 50, because then the risk of sliding of these ends on the articulation stirrup 50 is less. It is specified that as a variant, only one of the locking elements 30, 40 could have the added plates 38.

[0065] In any event, in this way, the lifting cylinder 6 is prevented from retracting below a minimum extension defined by the length of the elongated portions 31A, 31B, and the lifting arm 5 is thus prevented from returning to its lowered position shown in the. Thus, an operator can safely intervene on a part of the handling machine 1 which is located below the lifting arm 5.

[0066] It is specified that as a variant, the number of tenons 32, 33, 34 and mortises 35, 36, 37 may be other than three, provided that the locking elements 30, 40 can be assembled to each other as has just been described.

[0067] Furthermore, as a variant, the locking elements 30, 40 can be assembled in any other suitable way, for example using screws. The assembly described above by means of the tenons 32, 33, 34 and the mortises 35, 36, 37 is however preferable because it is particularly easy to carry out and does not require any tools.

[0068] In a variant not shown, the barrel 61 can be mounted articulated on the lifting arm 5 while the cylinder 62 is mounted articulated on the chassis 2. The use of the locking device 20 in this case is identical to that described previously.

[0069] The locking elements 30, 40 can be mounted on board the handling machine 1 in a compartment provided for this purpose. For example, this compartment can be located in the driver's cab 4 or located on one side of the chassis 2.

[0070] However, it is preferable that the locking elements 30, 40 are fixed to the frame 2 at a location which is located under the lifting arm 5 and which is accessible when the lifting arm 5 is raised. Referring now to and to, an example of fixing the locking elements 30, 40 according to this principle is described.

[0071] As shown schematically in the, the chassis 2 may comprise two side members 500. The side members 500 extend parallel to each other. In a manner known per se and not shown, the lifting arm 5 is pivotally mounted between the two side members 500. The axis X1 is thus perpendicular to the side members 500. Preferably, the side members 500 extend parallel to the longitudinal direction of the handling machine 1, so that the axis X1 is oriented horizontally and transversely.

[0072] Still with reference to 1a, a support plate 510 extends between the two side members 500, for example perpendicular to the two side members 500. The support plate 510 may be attached to the side members 500 or to another element of the chassis 2. The support plate 510 is located under the lifting arm 5 when the latter is in its lowered position shown in 1a and 1a. The support plate 510 and the side members 500 thus delimit a space 800 (cf.) under the lifting arm 5, this space 800 becoming accessible when the lifting arm 5 is raised.

[0073] With reference to 1a and 1b, a fixing plate 600, only one of which is shown in 1a, is attached to each of the side members 500 and / or to the support plate 510. The fixing plate 600 has a through hole (not referenced) which is shaped to receive a knurled screw 80. Furthermore, with reference to 1a, each of the locking elements 30, 40 has a through hole 311, here made on the elongated portion 31A, to receive the knurled screw 80. Thus, each of the locking elements 30, 40 can be fixed to the chassis 2, simply by positioning the through hole 311 opposite the through hole of the fixing plate 600, then inserting and tightening the knurled screw 80.

[0074] Alternatively, the locking elements 30, 40 to the chassis 2 in the space 800 can be fixed to the side members 500 in the space 800 in any other suitable manner, for example using screws. The fixing described above by means of the knurled screw 80 and the fixing plate 600 is however preferable because it is particularly easy to carry out and does not require tools.

[0075] The locking device 20 can be used for locking a lifting cylinder integrated into a handling machine or any other cylinder.

[0076] Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0077] The use of the verb "comprise", "comprise" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0078] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

A locking device (20) for a cylinder (6), the locking device (20) comprising two locking elements (30, 40), each locking element (30, 40) having a first end and a second end opposite the first end, wherein the two locking elements (30, 40) are configured to be assembled to each other in an assembled configuration in which the two locking elements (30, 40) together define a central space (400) for a rod (62) of the cylinder (6), wherein, in the assembled configuration, a distance between the first end and the second end of a locking element (30, 40) defines a minimum extension of the cylinder (6), said minimum extension of the cylinder (6) being reached when a) the first end of each of the two locking elements (30,40) is abutted against an end surface of a barrel (61) of the cylinder (6) in which the rod (62) slides, and b) the second end of each of the two locking elements (30, 40) is abutted against a pivot bracket (50), the pivot bracket (50) receiving a pivot shaft, one end of the rod (62) opposite the barrel (61) being mounted articulated to the pivot shaft. Locking device (20) according to claim 1, wherein the two locking elements (30, 40) have a generally L-shaped cross-section. Locking device (20) according to any one of claims 1 to 2, wherein each of the two locking elements (30, 40) has at least one tenon (32, 33, 34), said at least one tenon (32, 33, 34) being intended to be received in a mortise (35, 36, 37) which has the other locking element (30, 40) so as to achieve the assembled configuration. Locking device (20) according to claim 3, in which each of the two locking elements (30, 40) has three tenons (32, 33, 34), said three tenons (32, 33, 34) comprising a retaining tenon (33), the retaining tenon (33) having a through hole (331) configured to receive a pin (70) to retain the two locking elements (30, 40) in the assembled configuration. Locking device (20) according to any one of claims 3 to 4, wherein each of the two locking elements (30, 40) further comprises at least one light (39). Locking device (20) according to any one of claims 1 to 5, wherein at least one of the two locking elements (30, 40) comprises, at its second end, an added plate (38) configured to come against the articulation bracket (50). Locking device (20) according to any one of claims 1 to 6, wherein the two locking elements (30, 40) are identical. Handling machine (1) comprising: - a chassis (2) movable relative to the ground surface; - a lifting arm (5) mounted pivoting on the chassis (2) around an axis of rotation (X1), so as to be mobile between a lowered position and a raised position; - a lifting cylinder (6) for pivoting the lifting arm (5), the lifting cylinder (6) comprising: a barrel (61) mounted articulated to one of the chassis (2) and the lifting arm (5) around a first axis of articulation (X2); and a rod (62) mounted to slide in the barrel (61) and mounted articulated to the other of the chassis (2) and the lifting arm (5) via an articulation shaft, the articulation shaft extending along a second articulation axis (X3) parallel to the first articulation axis (X2) and being received in an articulation bracket (50) which is present on the other of the chassis (2) and the lifting arm (5);and a locking device (20) for blocking movement of the lifting arm (5) towards the lowered position, wherein the locking device (20) comprises two locking elements (30, 40), each locking element (30, 40) having a first end and a second end opposite the first end, wherein the two locking elements (30, 40) are configured to be assembled together in an assembled configuration in which the two locking elements (30, 40) together define a central space (400) through which the rod (62) passes, wherein, in the assembled configuration, the first end of each of the locking elements (30, 40) abuts against an end surface of the shaft (61), and the second end of each of the two locking elements (30, 40) is configured to abut against the articulation bracket (50) so as to block said movement of the lifting arm (5) towards the position lowered.; Handling machine (1) according to claim 8, wherein the two locking elements (30, 40) have a generally L-shaped cross-section. Handling machine (1) according to any one of claims 8 to 9, wherein each of the two locking elements (30, 40) has at least one tenon (32, 33, 34), said at least one tenon (32, 33, 34) being intended to be received in a mortise (35, 36, 37) which has the other locking element (30, 40) so as to achieve the assembled configuration. Handling machine (1) according to claim 10, wherein each of the two locking elements (30, 40) has three tenons (32, 33, 34), said three tenons (32, 33, 34) comprising a retaining tenon (33), the retaining tenon (33) having a through hole (331) configured to receive a pin (70) to retain the two locking elements (30, 40) in the assembled configuration. Handling machine (1) according to any one of claims 10 to 11, wherein each of the two locking elements (30, 40) further comprises at least one light (39). Handling machine (1) according to any one of claims 8 to 12, wherein at least one of the two locking elements (30, 40) has, at its second end, an added plate (38) configured to come against the articulation bracket (50). Handling machine (1) according to any one of claims 8 to 13, wherein the two locking elements (30, 40) are identical. Handling machine (1) according to any one of claims 8 to 14, wherein each of the two locking elements (30, 40) is configured to be fixed to the chassis (2). Handling machine (1) according to any one of claims 8 to 15, in which the chassis comprises two longitudinal members (500) extending parallel to each other, the lifting arm (5) being pivotally mounted between the two longitudinal members (500). Handling machine (1) according to claim 15 and claim 16 taken in combination, wherein at least one of the locking elements (30, 40), and preferably both locking elements (30, 40), are configured to be fixed to the chassis (2) at a space (800) located between the two longitudinal members (500), under the lifting arm (5) when the lifting arm (5) is in the lowered position.

Images