DEVIL WITH ASSISTANCE

Abstract

The invention relates to an assisted hand truck for lifting, moving and placing a load (500), comprising a frame (100) defining a support plane (P) for a side of the load and carrying at its base a platform (102) intended to receive the load; two wheels (104) mounted to rotate about the same axis of rotation (X1) to allow the hand truck to move; a stabilizer (200) mounted movably on the frame and comprising a shoe (201) extending in front of the axis of rotation and a stand (202, 203) extending behind the axis of rotation; an assistance actuator (300) for selectively moving the frame relative to the stabilizer between a loading position in which the platform is close to the ground and the hand truck is in contact with the ground by its wheels and the platform or the shoe, and a moving position in which the platform is raised and the hand truck is in contact with the ground by its wheels and the stand;so that during a transition from the loading position to the moving position, the hand truck rests on the ground by the shoe until a center of gravity of the assembly tilts behind the axis of rotation of the wheels causing the shoe to be lifted and the hand truck to rest on the ground by the stand, and during a transition from the moving position to the loading position, the hand truck rests on the ground by the stand until the center of gravity of the assembly tilts in front of the axis of rotation of the wheels causing the stand to be lifted and the hand truck to rest on the ground by the shoe. FIGURE OF THE ABSTRACT: [Fig. 1];

Description

Title of the invention: Devil has assistance

[0001] BACKGROUND OF THE INVENTION

[0002] The present invention relates to the field of moving bulky loads such as household appliances. Handlers, delivery men or movers use handcart-type devices to move such loads, comprising a structure called a frame equipped with wheels mounted to rotate around the same axis of rotation. The frame is equipped at its base with a platform, called a shovel or flap, intended to receive the load.

[0003] In all that follows, the terms front and rear are to be understood relative to a direction of advancement of the hand truck pushed by the user. To move a load, the user begins by engaging the platform of the hand truck under the load. Then the user performs a tilting movement of the frame around the axis of rotation of the wheels so that the load is lifted by the platform and comes to bear against the frame. The center of gravity of the assembly is then brought behind the axis of rotation of the wheels, and the user is then able to move the load. However, the tilting movement imposes on the user a non-ergonomic posture and a sometimes significant restraining effort to cause the load to tilt and prevent the assembly from falling backward. The maneuver requires experience and its repetitions prove tiring for the body.

[0004] SUBJECT OF THE INVENTION

[0005] The invention aims in particular to facilitate and secure the transport of a load using a hand truck. Summary of the invention

[0006] For this purpose, according to the invention, there is provided a hand truck with assistance for lifting, moving and placing a load, comprising: - a frame provided at its base with a platform intended to receive the load and defining a support plane for one side of the load; - two wheels mounted to rotate along the same axis of rotation to allow the hand truck to move; - a stabilizer mounted movably on the frame and comprising a shoe extending in front of the axis of rotation of the wheels and a stand extending behind the axis of rotation of the wheels; - an assist actuator for selectively changing a relative position of the frame and the stabilizer between a loading position in which the platform is close to the ground and the hand truck is in contact with the ground by its wheels and the platform or the shoe, and a travel position in which the platform is raised and the hand truck is in contact with the ground by its wheels and the crutch;

[0007] so that during a transition from the loading position to the moving position, the handcart rests on the ground by the shoe until a center of gravity of the assembly tilts behind the axis of rotation of the wheels, causing the shoe to be lifted and the handcart to rest on the ground by the stand, and during a transition from the moving position to the loading position, the handcart rests on the ground by the stand until the center of gravity of the assembly tilts in front of the axis of rotation of the wheels, causing the stand to be lifted and the handcart to rest on the ground by the shoe.

[0008] Thus, while the frame is in the loading position, the user slides the platform under the load. The hand truck then rests on the ground by the platform or the shoe, depending on which of these two elements is in contact with the ground. Then the user controls the assistance actuator to bring the frame into the travel position. If the hand truck is not already resting on its shoe, the movement initiated by the actuator will cause this support. The actuator continues to move the frame relative to the stabilizer while the latter is resting on the shoe, until the center of gravity of the assembly passes behind the axis of rotation of the wheels. The hand truck then tilts to rest on the stand while the frame arrives in the travel position, which is then stable. The load is both resting on the platform by its base, and resting on the frame by its side. The user only has to push the hand truck to move the load.The user did not have to exert any tilting force to bring the hand truck into the travel position. The transition from the travel position to the loading position causes the hand truck to tilt, during which the stand is raised and the hand truck rests on the shoe when the center of gravity of the assembly passes in front of the axis of rotation of the wheels. At the end of the transition, if necessary, the platform may come into contact with the ground.

[0009] Preferably, the stabilizer is articulated on the frame around a hinge axis parallel to the axis of rotation of the wheels. This kinematic arrangement is very simple, the actuator can then consist of a simple telescopic cylinder coupled between the frame and the stabilizer. Preferably then, the hinge axis is in front of the axis of rotation of the wheels.

[0010] According to a particular embodiment, the shoe is a metal blade extending under the platform, and the crutch comprises at least one arm carrying a loose wheel.

[0011] According to a particular arrangement, the wheels are rotated by the frame.

[0012] According to another particular arrangement, the wheels are motorized.

[0013] Preferably then, the handcart comprises means for controlling the motorized wheels to automatically move the handcart forward or backward while it is in the loading position, during loading or unloading.

[0014] More preferably, the hand truck comprises a haptic handle controlling the motorized wheels to assist in moving the hand truck.

[0015] According to a particular arrangement, the hand truck is equipped with at least one battery carried by the frame.

[0016] Other characteristics and advantages of the invention will emerge from reading the following description of a particular and non-limiting embodiment of the invention. Brief description of the drawings

[0017] Reference will be made to the accompanying drawings, among which:

[0018] [Fig-1] [Fig.l] is a perspective view of a hand truck with assistance according to a mode particular method of carrying out the invention;

[0019] [Fig.2] [Fig.2] is a perspective view from another angle of the devil of the [Fig.l];

[0020] [Fig.3a] [Fig.3a] is a side view of the devil of [Fig.l] shown in position of movement;

[0021] [Fig.3b] [Fig.3b] is a partial exploded view of [Fig.3a];

[0022] [Fig.4a] [Fig.4a] is a side view of the devil of [Fig.l] shown in position loading;

[0023] [Fig.4b] [Fig.4b] is a partial detail view of [Fig.4a];

[0024] [Fig.5] [Fig.5] is a schematic sequence showing different stages of the use of the devil of [Fig.l];

[0025] [Fig.6] [Fig.6] is a perspective view of the handcart of [Fig.l] loaded with loading position;

[0026] [Fig.7] [Fig.7] is a perspective view of the devil of [Fig.l] loaded with moving position. DETAILED DESCRIPTION OF THE INVENTION

[0027] With reference to Figures 1 and 2, the illustrated hand truck 1 comprises a frame 100 comprising a chassis 101, here made of welded metal tubes, defining towards the front a support plane P for the side of a load (such as for example a refrigerator, a stack of microwave ovens, etc.) to be moved. The chassis 101 carries at its lower end a platform 102, here made of folded sheet metal to present a flap 103 fixed on the chassis 101. Two wheels 104 are rotatably mounted on the chassis 101 around the same axis of rotation XI, here motorized wheels whose motors are powered by a battery 105 carried by the chassis 101. The chassis 101 comprises at the rear a handle 107 also forming a bumper. The frame 100 carries a control panel 108 comprising various controls which will be described later. This control panel communicates with a control unit 106 also carried by the chassis 101.

[0028] According to an essential aspect of the invention, the hand truck 1 comprises a stabilizer 200 which comprises a shoe 201 in the form here of a blade (here a metal blade) extending in front of the axis of rotation XI under the platform 102, and two arms 202 fixed to the shoe 201 and extending behind the axis of rotation XI to carry idler wheels 203. The arms 202 and the idler wheels 203 form a crutch of the stabilizer (here a double crutch for reasons of stability, but the crutch could be simple and comprise only one arm).

[0029] As can be seen in Figures 3a and 3b, the frame 100 and the stabilizer 200 are articulated together along a hinge axis X2 parallel to the axis XI of rotation of the wheels. An assistance actuator 300, here an electric screw jack, is coupled to the frame 100 and to the stabilizer 200 to selectively place the hand truck in the travel position as illustrated in Figures 1, 2, 3a, or in the loading position as illustrated in [Fig. 4a]. In this figure, the hand truck 1 is supported on the ground by its wheels 104 and by the end of the platform 102 configured in the shape of a beak 110 more visible in [Fig. 4b]. The beak 110 facilitates the introduction of the platform under the load. It will be noted that the shoe 201 is itself very close to the ground, and possibly even already in contact with it. In the moving position illustrated in [Fig.3a], the hand truck 1 is supported on the ground by the wheels 104 and by the idler casters 203, therefore by its stand.It will be noted that given the position of the articulation axis X2 in front of the axis XI of rotation of the wheels as illustrated in [Fig.4b], the shoe 201 lowers when the handcart 100 is brought into the loading position, and raises when the handcart is brought into the moving position, in addition to its raising caused by the tilting of the frame 100 to come to bear on the idler wheels 203.

[0030] The control console 108 comprises various commands for communicating with the control unit 106 controlling the actuator 300 and the wheel motors 104, including: - an emergency stop button B AU; - an engagement button B1 allowing the wheels 104 to be turned to move the hand truck forward under the load during loading; - a disengagement button B2 allowing the wheels 104 to be turned to move the hand truck backward under the load during unloading; - a straightening button B3 allowing the assistance actuator 300 to be controlled to move the hand truck from the travel position to the loading position; - a tilt button B4 for controlling the assistance actuator 300 to move the hand truck from the loading position to the travel position; - a haptic handle 109, allowing the hand truck to be moved by action on these drive wheels. For example, a haptic handle of the type described in document FR3121419 could be used.

[0031] The use of the hand truck of the invention is now described with reference to the sequence illustrated in [Fig. 5]. In step A, while the hand truck 1 is in the loading position resting on the spout 110 of the platform 102, the user has brought the hand truck 1 close to the load 500. He presses the button B1 to apply a forward torque to the wheels 104 by their respective motors. For the moment, the hand truck 1 is coming up against the load 500 so that it cannot move forward. In step B, the user slightly tilts the load 500 to allow the platform 102 to engage under the load. In step C, driven by the wheels 104 which begin to rotate under the effect of the torque applied by their respective motors, the hand truck 1 moves forward by itself until the frame comes up against the load 500 or the platform is blocked under the load. In step D, the user releases the load 500 which then rests on the platform 102.The wheel motors 104 are stopped in at least one of the following circumstances: . - contact of the hand truck, and in particular the frame, with the load, - after a determined time (typically a few seconds) - after traveling a determined distance.

[0032] In [Fig.6] we see the load 500 in place on the platform 102 of the hand truck 1. In this configuration, the hand truck 1 rests on the ground by the beak 110 of the platform 102, while the idler wheels 203 are slightly lifted off the ground. In step E, the user presses the button B4 to cause the hand truck to tilt towards the moving position. During this step, the actuator 300 acts on the stabilizer so as to bring the shoe 201 into contact with the ground, which causes the progressive tilting of the frame 100. The load comes to bear by its side on the support plane P, and the center of gravity of the assembly passes at a given moment behind the axis XI of rotation of the wheels 104, which causes the shoe 102 to detach and the hand truck 1 to rest on its stand (here on the idler wheels 203). We then arrive at the movement position illustrated in step F. In this position, the user can move the hand truck 1 using the haptic handle 109 which controls the wheels 104 to assist the user.This then provides only a reduced movement effort. In step G, the user has arrived at the unloading location, stopped, and pressed button B3 to control actuator 300 to tilt hand truck 1 from the travel position to the loading position. Hand truck 1, after having tilted. to initially take support on the shoe 201, takes support at the end of tilting on the beak 110 of the platform 102. In step G, the user presses the button B2 to impart a recoil torque to the wheels 104 to move the hand truck backward. However, the hand truck cannot move backward given the weight of the load 500 on the platform. In step H, the user has tilted the load 500 to allow the hand truck to move backward, which releases itself from the load 500, which the user can then leave to rest on the ground as illustrated in step I. The motors of the wheels 104 are stopped in at least one of the following circumstances: - contact of the devil with an obstacle; - after a set time (typically a few seconds); - after covering a specific distance.

[0033] Thus, thanks to the actuator 300, the tilting of the hand truck from the loading position to the tilting position is assisted (buttons B3 and B4), which greatly relieves the user. The moving position is a stable position, so that the user no longer has to manage the tilted position of the hand truck during movement.

[0034] Similarly, the assistance in engaging or disengaging the handcart under the load (buttons B1 and B2) greatly facilitates the task of the user, who only has to worry about tipping the load without having to simultaneously manipulate the handcart.

[0035] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention.

[0036] In particular, although here the wheels 104 are carried by the frame 100, they may be carried by the stabilizer 200.

[0037] Although here the shoe 201 takes the form of a sheet extending under the platform, which makes it possible to limit the lateral bulk of the hand truck and limit the height of the platform, the shoe may take other forms, such as a skate or a crosspiece carried at the end of an arm. The shoe may extend under the platform, on the side of the platform, or be integrated into an opening in the platform.

[0038] Although here the hand truck rests on the end of the beak-shaped platform when it is in the loading position, the hand truck may rest on the shoe 201, the platform remaining slightly detached from the ground. Alternatively, the hand truck may rest on both the shoe and the platform, if these two elements are level in the loading position.

[0039] Although the stand here is a double stand equipped with idler wheels 203, the stand may take other forms, such as a single stand ending in a skate.

[0040] Although here the wheels 104 are motorized, they may not be. In this case the user will not be able to benefit from assistance in engaging and disengaging the platform of the hand truck under the load, nor from assistance in moving the hand truck, but nevertheless retains assistance in tilting the hand truck. between the loading position and the travel position by means of the assistance actuator.

[0041] Although here the assistance actuator is an electric screw jack, other types of actuators can be used, such as rotary actuators.

[0042] Although here, the frame and the stabilizer are articulated to each other, they may more generally be movable relative to each other, for example by a deformable parallelogram connection, while defining between them a loading position and a displacement position.

Claims

Claims

1. A hand truck with assistance for lifting, moving and placing a load (500), comprising: - a frame (100) defining a support plane (P) for one side of the load and carrying at its base a platform (102) intended to receive the load; - two wheels (104) mounted to rotate about the same axis of rotation (XI) to allow the hand truck to move; - a stabilizer (200) mounted movably on the frame and comprising a shoe (201) extending in front of the axis of rotation and a stand (202,203) extending behind the axis of rotation; - an assist actuator (300) for selectively moving the frame relative to the stabilizer between a loading position in which the platform is close to the ground and the hand truck is in contact with the ground by its wheels and the platform or the shoe, and a travel position in which the platform is raised and the hand truck is in contact with the ground by its wheels and the stand;such that during a transition from the loading position to the moving position, the hand truck rests on the ground by the shoe until a center of gravity of the assembly tilts behind the axis of rotation of the wheels, causing the shoe to be lifted and the hand truck to rest on the ground by the stand, and during a transition from the moving position to the loading position, the hand truck rests on the ground by the stand until a center of gravity of the assembly tilts in front of the axis of rotation of the wheels, causing the stand to be lifted and the hand truck to rest on the ground by the shoe.;

2. A hand truck according to claim 1, wherein the stabilizer (200) is articulated on the frame (100) around an articulation axis (X2) parallel to the axis of rotation (XI) of the wheels (104).

3. A hand truck according to claim 1, wherein the wheels (104) are rotatably carried by the frame (100).

4. A hand truck according to claims 1 to 3, wherein the articulation axis (X2) is in front of the axis of rotation of the wheels (XI).

5. A hand truck according to claim 1, wherein the shoe (201) is a blade extending under the platform (102).

6. A hand truck according to claim 1, wherein the stand comprises at least one arm (202) carrying an idler wheel (203).

7. A hand truck according to claim 1, wherein the wheels (104) are motorized.

8. Hand truck according to claim 7, comprising control means (B1, B2) for the motorized wheels (104) to automatically move the hand truck forward or backward while it is in the loading position, during loading or unloading.

9. A hand truck according to claim 7, comprising a haptic handle (108) controlling the motorized wheels (104) to assist in moving the hand truck when the hand truck is in the moving position.

10. A hand truck according to claim 1, wherein the frame carries a battery.

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