DEVIL HAS ASSISTANCE

Abstract

The invention relates to a hand truck with assistance for lifting, moving and setting down 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) movably mounted on the frame and comprising a shoe (201) extending in front of the axis of rotation and a support leg (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 support leg;so that during a transition from the loading position to the moving position, the hand truck rests on the ground by the foot until the center of gravity of the assembly tilts behind the axis of rotation of the wheels, causing the foot to lift and the hand truck to rest on the ground by the support leg, and during a transition from the moving position to the loading position, the hand truck rests on the ground by the support leg until the center of gravity of the assembly tilts in front of the axis of rotation of the wheels, causing the support leg to lift and the hand truck to rest on the ground by the foot. FIGURE OF THE ABRIDGED: [Fig. 1];

Description

Title of the invention: DiablE has ASSISTANCE

[0001] BACKGROUND OF THE INVENTION

[0002] The present invention relates to the field of moving bulky loads such as household appliances. Handling personnel, delivery drivers, or movers use hand truck-type devices to move such loads, comprising a structure called a frame equipped with wheels mounted to rotate around the same axis. The frame is equipped at its base with a platform, called a shovel or toe plate, designed to receive the load.

[0003] In all that follows, the terms front and rear are to be understood relative to the direction of forward movement of the hand truck pushed by the user. To move a load, the user begins by engaging the hand truck platform under the load. Then, the user performs a rocking motion of the frame around the axis of rotation of the wheels so that the load is lifted by the platform and comes to rest 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 rocking motion forces the user into a non-ergonomic posture and sometimes requires significant restraint to initiate the rocking motion and prevent the assembly from falling backward. The maneuver requires experience, and its repetition proves tiring for the body.

[0004] SUBJECT OF THE INVENTION

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

[0006] For this purpose, the invention provides a hand truck with assistance for lifting, moving and setting down a load, comprising: - a frame equipped 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 around the same axis of rotation to allow the hand truck to move; - a stabilizer mounted movably on the frame and comprising a skid extending in front of the axis of rotation of the wheels and a kickstand extending behind the axis of rotation of the wheels; - an assist actuator to selectively modify the relative position of the frame and 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 foot, 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 kickstand;

[0007] so that during a transition from the loading position to the moving position, the hand truck takes support 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 lift and the hand truck to take support on the ground by the kickstand, and during a transition from the moving position to the loading position, the hand truck takes support on the ground by the kickstand until the center of gravity of the assembly tilts in front of the axis of rotation of the wheels causing the kickstand to lift and the hand truck to take support 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 via the platform or the skid plate, depending on which of these two elements is in contact with the ground. The user then activates the assistance actuator to bring the frame into the moving position. If the hand truck is not already resting on its skid plate, the movement initiated by the actuator will cause it to do so. The actuator continues to move the frame relative to the stabilizer while the latter rests on the skid plate, 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 support leg as the frame reaches the moving position, which is now stable. The load is supported both by the base of the platform and by its side on the frame. The user then simply has to push the hand truck to move the load.The user did not need to exert any tilting effort to bring the hand truck into the moving position. The transition from the moving position to the loading position causes the hand truck to tilt, during which the support leg lifts and the hand truck rests on the base when the center of gravity of the assembly passes in front of the wheel axis. At the end of the transition, the platform may, if necessary, come into contact with the ground.

[0009] Preferably, the stabilizer is articulated on the frame around a pivot axis parallel to the axis of rotation of the wheels. This kinematic arrangement is very simple, the actuator then consisting of a simple telescopic cylinder coupled between the frame and the stabilizer. Preferably, the pivot 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 includes at least one arm carrying a free-spinning 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 dolly includes means for controlling the motorized wheels to automatically move the dolly forward or backward while it is in the loading position, during loading or unloading.

[0014] Preferably, the hand truck includes a haptic handle controlling the motorized wheels to assist in moving the hand truck.

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

[0016] Other features and advantages of the invention will become apparent from the following description of a particular, non-limiting embodiment of the invention. Brief description of the drawings

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

[0018] [Fig-1] Fig. 1 is a perspective view of a hand truck with assistance according to a mode particular implementation of 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 from [Fig. 1] shown in position of movement;

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

[0022] [Fig. 4a] [Fig. 4a] is a side view of the devil from [Fig. 1] shown in position loading;

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

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

[0025] [Fig.6] Fig.6 is a perspective view of the devil in Fig.1 loaded with loading position;

[0026] [Fig.7] Fig.7 is a perspective view of the devil in Fig.1 loaded with position of movement. DETAILED DESCRIPTION OF THE INVENTION

[0027] With reference to Figures 1 and 2, the illustrated hand truck 1 comprises a frame 100 having a chassis 101, here made of welded metal tubing, defining a support plane P at the front 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 to the chassis 101. Two wheels 104 are mounted to rotate on the chassis 101 about the same axis of rotation XI; here, these are motorized wheels whose motors are powered by a battery 105 carried by the chassis 101. The chassis 101 has at the rear a handle 107 which also forms 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 mounted on chassis 101.

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

[0029] As can be seen in Figures 3a and 3b, the frame 100 and the stabilizer 200 are articulated to each other along a pivot axis X2 parallel to the axis XI of rotation of the wheels. An assist actuator 300, here an electric screw jack, is coupled to the frame 100 and the stabilizer 200 to selectively place the hand truck in the travel position as illustrated in Figures 1, 2, and 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 clearly visible in [Fig. 4b]. The beak 110 facilitates the insertion of the platform under the load. It should 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 free-rolling casters 203, therefore by its kickstand.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 dolly 100 is brought into the loading position, and rises when the dolly is brought into the moving position, in addition to its raising caused by the tilting of the frame 100 to come to rest on the idle wheels 203. .

[0030] The control panel 108 includes various controls for communicating with the control unit 106 which controls the actuator 300 and the wheel motors 104, including: - an emergency stop button B AU; - an engagement button B1 allowing the wheels 104 to rotate to move the dolly forward under the load during loading; - a disengagement button B2 allowing the wheels 104 to rotate to move the hand truck backward under the load during unloading; - a B3 straightening button allowing the 300 assistance actuator to be controlled to move the hand truck from the travel position to the loading position; - a B4 toggle button to control the 300 assistance actuator to move the hand truck from the loading position to the moving position; - a haptic handle 109, allowing the hand truck to be moved by acting on its 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 beak 110 of the platform 102, the user brings the hand truck 1 close to the load 500. They press button B1 to apply a driving torque to the wheels 104 via their respective motors. At this point, the hand truck 1 is stopped by the load 500 and 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 on its own until the frame stops against the load 500 or the platform becomes stuck under the load. At step D, the user releases the load 500 which then rests on the platform 102.The motors of the 104 wheels are stopped in at least one of the following circumstances: . - contact of the devil, and in particular of the frame, with the load, - after a determined time (typically a few seconds) - after traveling a determined distance.

[0032] Figure 6 shows the charge 500 in place on the platform 102 of the devil 1. In this configuration, the hand truck 1 rests on the ground by the beak 110 of the platform 102, while the swivel casters 203 are slightly raised off the ground. At step E, the user presses button B4 to tilt the hand truck into the moving position. During this step, actuator 300 acts on the stabilizer to bring the shoe 201 into contact with the ground, causing the frame 100 to tilt progressively. The load comes to rest on its side against the support plane P, and the center of gravity of the assembly shifts at a certain point behind the axis XI of rotation of the wheels 104, causing the shoe 102 to lift off the ground and the hand truck 1 to rest on its support leg (here, on the swivel casters 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 requires only a reduced effort to move. At step G, the user arrived at the unloading location, stopped, and pressed button B3 to activate actuator 300 in order to tilt the hand truck 1 from the moving position to the loading position. The hand truck 1, after tilting... Initially supported by the shoe 201, it rests at the end of its tilting motion on the beak 110 of the platform 102. In step G, the user presses button B2 to apply a recoil torque to the wheels 104 to reverse the hand truck. However, the hand truck cannot reverse due to 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 reverse, freeing itself from the load 500, which the user can then place on the ground as illustrated in step I. The motors of the wheels 104 are stopped under at least one of the following circumstances: - contact of the devil with an obstacle; - after a set amount of time (typically a few seconds); - after traveling a predetermined distance.

[0033] Thus, thanks to 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 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 dolly under the load (buttons B1 and B2) greatly facilitates the task of the user, who only has to take care of tilting the load without having to simultaneously manipulate the dolly.

[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 supported by the frame 100, they can be supported by the stabilizer 200.

[0037] Although here the shoe 201 takes the form of a sheet metal plate extending under the platform, which limits the lateral bulk of the hand truck and reduces the platform height, the shoe can take other forms, such as a skid or a crossbar mounted at the end of an arm. The shoe can extend under the platform, along 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 in the loading position, the hand truck can rest on the shoe 201, with the platform remaining slightly raised off the ground. Alternatively, the hand truck can rest on both the shoe and the platform, provided that both are level in the loading position.

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

[0040] Although the wheels 104 are motorized here, they may not be. In this case, the user will not benefit from assistance with engaging and disengaging the hand truck platform under load, nor from assistance with moving the hand truck, but will still have assistance with tilting the hand truck. between the loading position and the movement position by means of the assist actuator.

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

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

Claims

Demands

1. A hand truck with assistance for lifting, moving and setting down 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) for receiving the load; - two wheels (104) mounted to rotate about the same axis of rotation (XI) to allow movement of the hand truck; - a stabilizer (200) movably mounted on the frame and comprising a skid (201) extending in front of the axis of rotation and a support leg (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 skid, 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 support leg;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 lift and the hand truck to rest on the ground by the kickstand, and during a transition from the moving position to the loading position, the hand truck rests on the ground by the kickstand until a center of gravity of the assembly tilts in front of the axis of rotation of the wheels, causing the kickstand to lift and the hand truck to rest on the ground by the shoe.

2. 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. Hand truck according to claim 1, wherein the wheels (104) are rotated by the frame (100).

4. 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. Devil according to claim 1, wherein the shoe (201) is a blade extending under the platform (102).

6. Hand truck according to claim 1, wherein the stand comprises at least one arm (202) carrying a free-spinning wheel (203).

7. 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. Hand truck according to claim 7, comprising a haptic handle (108) controlling the motorized wheels (104) for assisting the movement of the hand truck when the hand truck is in a moving position.

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