Plate lifter

Abstract

TITLE: "Plate lifting device" Plate lifting device for carrying and presenting cladding plates for installation on a construction site, having a telescopic mast (10) formed of several elements (11, 12, 13), connected to a base (40) with rollers (43) and provided with a plate-carrying frame (30) connected by an adjustable joint to the upper end of the mast (10) and a mechanism for lifting the mast (10). The lower end of the mast (10) has an adjustable support (50) placed in a support position to rest on the ground only in the event of a load installed on the frame (30) and which is greater than a threshold. Figure 1

Description

Title of the invention: Plate lifting device FIELD OF THE INVENTION

[0001] The present invention relates to a plate lifting apparatus for presenting cladding plates for installation, having: a telescopic mast connected to a roller base and a plate-carrying frame connected by an adjustable joint to the upper end of the mast, and a mechanism for lifting the telescopic mast. STATE OF THE ART

[0002] Such a plate lifting device is known according to document FR 3 021 684.

[0003] A plate lifting device is also known according to document FR 82 21 795 which describes a device for raising and placing cladding or insulation plates on a ceiling or a wall. It consists of a telescopic mast formed of several elements and carried by a base with wheels. The mast is provided with a plate-carrying frame constituted by an assembly adjustable in width having a general H shape. The deployment of the mast is ensured by a mechanism comprising a winch connected by a cable to the elements of the telescopic mast. The base of this mast is retractable in that the branches of the base, provided with wheels, are carried by a sliding collar on the mast and locking in the deployed position or in the folded position.The legs of the base are connected by connecting rods to a fixed point on the mast so that the sliding of the collar and the legs carrying the rollers results in the folding of the legs close to the mast in the transport position, or their deployment, as far away as possible from the mast for fixed or mobile use of the device.

[0004] However, the plate lifters can be unstable in the deployed position when the plate to be laid is relatively heavy or at least when its weight exceeds a certain threshold. However, the weight of the plates varies greatly between very light plates and relatively heavy plates depending on the materials they are made of.

[0005] PURPOSE OF THE INVENTION

[0006] The aim of the present invention is to develop a plate lifting device of the type defined above offering better stability, in particular when a relatively heavy plate carried by the device is in the raised, positioning position.

[0007] DISCLOSURE AND ADVANTAGES OF THE INVENTION

[0008] To this end, the present invention relates to a plate lifting device of the type defined above, characterized in that the lower end of the mast is provided with a support adjustable between a deployed position, a retracted position and, between them, a support position, the retracted position being the position of the support out of contact with the ground whatever the load installed on the plate-carrying frame, the support position being the adjusted position, lowered relative to the ground so as to rest on the ground only under the effect of a load installed on the plate-carrying frame and which is greater than a threshold, to support the mast under the effect of the bending of the base.

[0009] The plate lifting device according to the invention has the advantage of being particularly stable for the installation of plates of a certain weight since the load is distributed both by the support of the bottom directly on the ground, receiving a fraction of the load of the plate and the support of the arms by their end. This distribution of the weight on four points is a particularly effective solution and which does not reduce the mobility of the plate lifting device for its installation in the appropriate place.

[0010] This distribution of the load of the plate avoids the oscillating movements of the mast which would, in the absence of the central support, be caused by the variable bending of the three arms of the base. In other words, the invention avoids the cumulative instability of the arms, that is to say the bending of one arm stressed more strongly than the other two. The transfer of part of the load to the upright avoids the floating of the upright connected to the bending arms.

[0011] This also improves the accuracy of holding the plate in the high position.

[0012] According to one characteristic, the adjustable support comprises a mushroom carried by a rod engaged in the lower end of the mast, and positioned in an adjusted manner in the mast to adjust the height of the support surface of the mushroom relative to the ground.

[0013] This embodiment of the adjustable support is particularly simple to produce and use.

[0014] The adjustable support is accessible and easily adjusted.

[0015] The installation of the adjustable support is facilitated if the rod is equipped with a stop limiting the movement of the adjustable support to the support position.

[0016] According to a particularly advantageous solution, the rod of the adjustable support is a threaded rod, screwed into a bearing at the lower end of the mast.

[0017] According to another advantageous characteristic, the telescopic mast is formed of a lower element, an intermediate element and an upper element constituted by telescopic tubes of polygonal section, in particular square, engaged one in the other, the upper element being engaged in an adjustable manner in the intermediate element.

[0018] According to another advantageous characteristic, the lifting mechanism consists of a pinion cooperating with a rack of the intermediate element, the pinion being carried by an axle provided with an actuating member.

[0019] This mechanism allows a reduction in the movement, that is to say a reduction in the effort required to lift the plate-carrying frame loaded with the plate.

[0020] According to an advantageous characteristic, the upper end of the lower element of the mast has a handle for moving or holding the apparatus. This handle under the support frame- plate is thus close to the load, that is to say the plate placed on the frame and this whether the frame is still in the low position or whether it is already in the raised position.

[0021] According to another advantageous characteristic, the device comprises a base formed of a front arm fixed relative to the mast and two lateral arms pivotally mounted at the base of the mast, being connected by connecting rods, in an articulated manner to a sliding sleeve engaged on the fixed arm and locked in the adjusted position.

[0022] This form of base has the advantage of being compact for transporting or storing the device.

[0023] According to another advantageous characteristic, the sliding sleeve locks onto the fixed front arm. This makes it possible to adjust the spacing of the two auxiliary arms, for example, on cluttered ground.

[0024] According to another advantageous characteristic, the plate-carrying frame comprises a main tube which is a double tube receiving separately by sliding an auxiliary tube for each of the sides of the frame and forming the main branch of the frame, this main tube being connected by an articulation to the upper element of the mast, a crosspiece at the end of each auxiliary tube, a central crosspiece secured to the main tube and a T-shaped extension of the central crosspiece.

[0025] This form of plate-carrying frame has the advantage of constituting a particularly stable support for the plate which is thus held flat, preventing it from bending between the two end supports formed by the crosspieces. Brief description of the drawings

[0026] The present invention will be described below in more detail with the aid of an embodiment of a plate lifting apparatus shown in the accompanying drawings in which:

[0027] [Fig-1] perspective view of a plate lifting device according to the invention,

[0028] [Fig.2] perspective view of a plate lifting device carrying a plate to be laid,

[0029] [Fig.3] detail view of the lower part of the lifting mast,

[0030] [Fig.4] detailed view of different positions of the adjustable support.

[0031] DESCRIPTION OF AN EMBODIMENT

[0032] According to [Fig.l], the invention relates to a plate lifting device 1 for carrying and presenting plates for installation. This height-adjustable plate lifting device 1 consists of a telescopic mast 10 provided with a lifting mechanism 20; the upper end of the mast 10 is connected to a plate-carrying frame 30; the mast rests on a base 40 fixed to the lower end of the mast.

[0033] The telescopic mast 10 is composed of a lower element 11 whose lower end 11b constituting the lower end of the mast 10 is connected to the base 40; the upper end 11a carries the lifting mechanism 20 for actuating an intermediate element 12 itself carrying an upper element 13 to which the plate-carrying frame 30 is connected. The lower element 11, the intermediate element 12 and the upper element 13 are tubes engaged in each other telescopically. The tubes forming the mast are tubes of polygonal section, in particular of square section, so as to be integral in rotation. The upper element 13 is engaged in an adjustable manner in the intermediate element 12 according to different positions defined by orifices or adjustment notches in the upper element 13 with a locking stud carried by the upper end of the intermediate element 12.

[0034] The plate-carrying frame 30 connected by an adjustable articulation 34 to the end of the upper element 13, is composed of a main branch 31 carrying at both ends, a crosspiece 32 provided with a stop 33. The main branch 31 is preferably telescopic, formed of a double main tube 311 receiving two auxiliary tubes 312, each secured to a crosspiece 32 so as to adjust the spacing of the crosspieces 32 according to the size of the plates. The adjustable articulation 34 is lockable, which makes it possible to tilt the plate-carrying frame 30 relative to the mast 10.

[0035] The lifting mechanism 20 consists of a rack made on the intermediate element 12 and a pinion housed in the housing 21 of the mechanism 20, meshing with the rack to deploy or retract the intermediate element 12 and adjust the height of the frame 30. For this, the mechanism 20 cooperating with the intermediate element 12 comprises a crank to actuate the pinion and a lock blocking the movement in the desired position.

[0036] The top 11a of the lower element 11 is provided with an operating handle 22 for pulling or pushing the plate lifting device.

[0037] The base 40 of the device is an articulated base formed of a front arm 41 fixed relative to the mast 10 and two lateral arms 42 pivotally mounted relative to the mast. The pivoted position is adjustable and locks.

[0038] The fixed front arm 41 is a tube, preferably of square section, one end of which is engaged in a horizontal tubular end piece 411, integral with the lower end 11b of the element 11. On the sides, the lower end 11b is provided with two yokes 46 forming the articulation of the corresponding end of each of the lateral arms 42. The ends of the arms 41, 42 are provided with a pivoting caster 43 equipped with a brake making it possible to block the caster. The lateral arms 42 are each connected by a connecting rod 44 to a sleeve 45 sliding on the front arm 4L

[0039] This sliding sleeve 45 laterally carries two yokes 46 receiving, by an articulation, the other end of each of the connecting rods 44. The sliding sleeve 45 is locked in the chosen sliding position on the front arm 41, preferably in the equiangular position of the arms 41, 42 making an angle of 120° between them.

[0040] The arm 41 is preferably directed forwards relative to the transverse orientation of the frame 30 and the plate P that the frame receives so that the operator can approach the frame 30 in the angular sector delimited by the two arms 42. This also facilitates access to the handle 36 fixed below the end of the central crosspiece 35 which extends on the other side of the main branch 311 by a T-shaped extension 37; this extension serves, like the central crosspiece 35, as an intermediate support for the plate received by the frame 30. Thus, the plate is supported in its middle by the crosspiece formed by the elements 311, 35, 37 and at the ends by the crosspieces 32.

[0041] The rectangular frame 30 has its center O vertical to the upright 10 so that the assembly is balanced with respect to the upright 10.

[0042] The central crosspiece 35 is preferably retractable by tilting or detaching a sleeve integral with the tube 311 to reduce the size for transporting and storing the device. The main tube 311 is, as already indicated, preferably a double tube separately receiving in a telescopic manner an extendable auxiliary tube 312. Preferably, the length of the double tube 311 makes it possible to receive the length of the auxiliary tube 312 in the retracted position and also the transverse extension of the tube 312 by retaining the latter over a sufficient length for the plate to be held by the crosspiece 32 at its end.

[0043] The articulation mechanism of the base 40 comprising the two yokes 46 of the lateral arms 42, carried by the lower end 11b of the lower element 11 and the tubular end piece 411 secured to the lower element 11 and receiving the front arm 41 constituting the rail for the sliding sleeve 45 to which the front end of the connecting rods 44 is articulated; their rear end is articulated to each of the lateral arms 42. The sliding sleeve 45 can advance freely on the front arm 41 to bring the lateral arms 42 closer together and reduce their spacing until they are folded against the front arm 4L. In the position shown in [Fig.l], the sliding sleeve 45 is located near the mast 10.

[0044] According to [Fig.l] and the detailed view of [Fig.3], the lower end of the mast 10 (in the case of the example, it is the lower end 11b of the lower tube 11) is equipped with an adjustable support 50 composed of a mushroom 51 carried by a rod 52 housed in a bearing 53 fixed to the mast 10.

[0045] The support 50 is adjustable between a retracted position PE ([Fig.3]) and a deployed position PD preceded by a support position PS of the support.

[0046] A bearing 53 is fixed to the lower part of the tube 11 to receive the rod 52. According to one embodiment, the rod 52 is threaded and the bearing 53 has a tapping 531. The top of the rod 53 preferably has a stop 521 limiting its deployed position PD corresponding, for example, to the support position of the mushroom 51 on the ground S when the device is not loaded. It can also be a position slightly above the ground S to allow the unloaded device 1 to be easily moved.

[0047] [Fig.2] shows a plate P installed on the device 1. The stops 33, at the end (high or front) of each crosspiece 32 allow the plate P to be correctly positioned on the frame 3 and the absence of a stop 33, at the other end of each crosspiece 32, facilitates the positioning of the plate P by sliding it on the crosspieces 32 as well as the reverse operation of removing the plate.

[0048] The intermediate supports of the crosspiece of the elements 35, 37 facilitate the sliding of the plate P. When the plate P is on the frame 30, the handle 36 remains easily accessible for holding or moving the device.

[0049] [Fig.4] in its parts AD shows the different positions that can be taken the adjustable support 50. The empty height Hv is, for example, the line HLv passing under the arms 41, 42.

[0050] In the unloaded, retracted position PE which corresponds to part A, the support 50 is at height H0 and the underside of the upright 10(11) is at level No.

[0051] Part B shows the adjustable support 50 in the support position PS at the height Hl, the underside of the upright 10(11) being at level No since, by hypothesis, the device is not loaded.

[0052] Part C shows the loaded apparatus: the arms are at height Hch below height Hv; the support 50 is against the ground S and the underside of the upright 10 (11) has descended to level NI.

[0053] The load is assumed to be greater than the fixed threshold. Part D shows the device with the support 50 in the deployed position PD in contact with the ground S. The arms 41, 42 are at the height Hv.

[0054] The support position PS makes it possible to distribute the load of the device between the arms 41, 42 supported on the ground by the casters 43 and the upright 10 (11) at its vertical or in the vicinity of this vertical is the center of gravity of the plate P which, depending on the case, can be a load greater than the fixed threshold resulting in the bending of the arms 41, 42 and the coming of the support 50 into contact with the ground S.

[0055] In this case, the load is distributed over four support points, which stabilizes the device by eliminating any possible swinging that might occur due to the elasticity of the arms 41, 42. The risk of elastic or oscillating movement would also exist in the case of the support 50 in the deployed position PD because the upright, through its support, would receive the entire load and in the event of a shift in the center of gravity relative to the upright, the latter would tilt and transfer a significant portion of the load to the single arm or the single pair of arms on the side of the inclination of the mast.

[0056] The support of the load distributed between the external contacts (the three rollers 43), followed by the contacting of the adjustable support in the support position allows this distribution of forces avoiding the swinging of the load.

[0057] The adjustment of the support 50 is done simply by screwing / unscrewing. However, this solution does not exclude the adjustment between the positions DE, DS, DP by hooking the rod 52 in the bearing 53 in three predefined locking positions, released by the actuation of a lock at the lower part of the upright 10.

[0058] NOMENCLATURE OF MAIN ELEMENTS

[0059] 1 Plate lifting device

[0060] 10 Telescopic mast

[0061] 10a Lower end of the mast

[0062] 11 Lower element

[0063] lia High end

[0064] 11b Low end

[0065] 111 Tubular tip

[0066] 112 Screed

[0067] 12 Intermediate element

[0068] 13 Upper element

[0069] 20 Lifting mechanism

[0070] 21 Box

[0071] 22 Operating handle

[0072] 30 Plate holder frame

[0073] 31 Main branch

[0074] 311 Main tube

[0075] 312 Auxiliary tube

[0076] 32 Crossing

[0077] 33 Stop

[0078] 34 Articulation

[0079] 35 Middle crosspiece

[0080] 36 Handle

[0081] 37 Extension

[0082] 40 Articulated base

[0083] 41 Fixed arm

[0084] 411 End piece fixed to the mast

[0085] 42 Side arm

[0086] 43 Swivel caster

[0087] 44 Connecting rod

[0088] 45 Sliding sleeve

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] 46 Clevis 50 Adjustable support 51 Mushroom 52 Rod 53 Bearing 531 Stop H Height from under the mast 0 Center of the crosspiece P Plate / load PD Deployed position PE Retracted position PS Support position S Ground surface

Claims

Claims

1. Plate lifting apparatus (1) for carrying and presenting cladding plates for installation, having: - a telescopic mast (10) connected to a base (40) with casters (43) and provided with a plate-carrying frame (30) connected by an adjustable articulation to the upper end of the mast (10), and - a lifting mechanism (20) of the mast (10), characterized in that the lower end (10a) of the mast (10) is provided with a support (50) adjustable between: * a deployed position (PD) * a retracted position (PE) and between them, * a support position (PS), - the retracted position (PE) being the position of the support (50) out of contact with the ground (S) regardless of the load installed on the plate-carrying frame (30), - the support position (PS) being the adjusted position, lowered relative to the ground (S) to rest on the ground only under the effect of a load installed on the plate-carrying frame (30) and which is greater than a threshold,to support the mast (10) under the effect of the bending of the base (40).,

2. Plate lifting device (1) according to claim 1, characterized in that the adjustable support (50) comprises - a mushroom (51) carried by a rod (52) engaged in the lower end of the mast (10), this rod (52) being positioned in an adjusted manner in the mast (10) to adjust the height of the support surface of the mushroom (51) relative to the ground (S).

3. Plate lifting device (1) according to claim 2, characterized in that the rod (52) of the support (50) is provided with a stop (521) limiting its deployed position.

4. Plate lifting device (1) according to claim 2, characterized in that the rod (52) of the adjustable support (50) is a threaded rod, screwed into a bearing (53) at the lower end (10a) of the mast (10).

5. Plate lifting device (1) according to claim 1, characterized in that the telescopic mast (10) is formed of a lower element (11), an intermediate element (12) and an upper element (13) constituted by telescopic tubes of polygonal section, in particular square, engaged one in the other, the upper element (13) being engaged in an adjustable manner in the intermediate element (12).

6. Plate lifting apparatus (1) according to claim 5, characterized in that the lifting mechanism (20) consists of a pinion cooperating with a rack of the intermediate element (12), the pinion being carried by an axle provided with an actuating member.

7. Plate lifting apparatus (1) according to claim 5, characterized in that the upper end (11a) of the lower element (11) has a handle (22) for moving or holding the apparatus (1).

8. Plate lifting device (1) according to claim 1, characterized in that it comprises a base (40) formed of a front arm (41) fixed relative to the mast (10) and two lateral arms (42) pivotally mounted at the base of the mast (10), being connected by connecting rods (44), in an articulated manner to a sliding sleeve (45) engaged on the fixed arm (41) and locked in the adjusted position.

9. Plate lifting apparatus (1) according to claim 8, characterized in that the sliding sleeve (45) locks on the fixed front arm (41).

10. Plate lifting apparatus (1) according to claim 5, characterized in that the plate-carrying frame (30) comprises: - a main tube (311) which is a double tube separately receiving by sliding an auxiliary tube (312) for each of the sides of the frame and forming the main branch (31) of the frame, this main tube being connected by an articulation (34) to the upper element (13) of the mast (10), - a crosspiece (32) at the end of each auxiliary tube (312), - a central crosspiece (35) integral with the main tube (311) and, - a T-shaped extension (37) of the central crosspiece (35).

Images