electric wheelchair tractor lifting mechanism

Abstract

This invention provides a wheelchair electric tractor lifting mechanism. A fixed frame is mounted on the front of the wheelchair, with wheels at the bottom. First and second connecting plates are laterally spaced on the fixed frame or tractor frame, with a third connecting plate located between them. A first shaft passes laterally through the first and second connecting plates. The third connecting plate has a rotatable mating part, with a radially opening for the first shaft to slide in and out, allowing the tractor frame to be swung and mounted on the fixed frame, enabling the lifting and lowering of the front of the wheelchair. The clamping assembly includes a second shaft, a pushing block, a compression spring, a positioning block, and an operating handle. The pushing block slides onto the second shaft, and its locking and unlocking parts can selectively abut against a protrusion on the positioning block. Moving the operating handle forward and backward drives the pushing block to rotate, thereby clamping or releasing the third connecting plate, achieving quick locking and releasing. This invention improves the convenience of connecting the electric tractor to the wheelchair, making it more reliable and user-friendly.

Claims

1. A wheelchair electric tractor lifting mechanism, wherein: The system includes a fixed frame, a towing head frame, a first connecting plate, a second connecting plate, a third connecting plate, a locking assembly, and a clamping assembly. The fixed frame is located at the front of the wheelchair frame, and the towing head frame has towing wheels at its bottom. The first and second connecting plates are connected to the fixed frame or the towing head frame, and the third connecting plate is connected to the towing head frame or the fixed frame. The locking assembly is located between the fixed frame and the towing head frame and is used to lock and unlock the relative displacement between the towing head frame and the fixed frame. The first and second connecting plates are laterally spaced, and the third connecting plate is located between the first and second connecting plates in the assembled state. A first shaft is laterally provided between the first and second connecting plates. The third connecting plate has a mating part for engaging with the outer circumference of the first shaft to rotate around the first shaft. A first sliding outlet is provided on one radial side of the mating part for the first shaft to slide in and out. The first shaft engages with the mating part so that the towing head frame can be rotatably mounted on the fixed frame to support the front of the wheelchair when the towing head frame is rotatably upright and to lower the front of the wheelchair when the towing head frame is rotatably tilted. The clamping assembly includes a second shaft, a pushing block, a compression spring, a positioning block, and an operating handle. The second shaft is transversely inserted through the first connecting plate and the second connecting plate. One end of the second shaft abuts against the outside of the first connecting plate, and the other end of the second shaft is sequentially fitted with the pushing block, the compression spring, and the positioning block. The pushing block is slidably sleeved on the second shaft and located between the second connecting plate and the compression spring. The pushing block has a locking part and an unlocking part formed on it, and the positioning block has a protrusion facing the pushing block. The operating handle is located on the pushing block so that when it is longitudinally pried in the front-back direction, it drives the pushing block to rotate around the second shaft, so that either the locking part or the unlocking part abuts against the protrusion, thereby pressing the pushing block against the outside of the second connecting plate. The third connecting plate is clamped between the first and second connecting plates, or the pushing block is moved away from the outside of the second connecting plate, releasing the clamping of the third connecting plate.

2. The wheelchair electric tractor lifting mechanism as described in claim 1, wherein: It also includes a limiting nut, which is screwed to the other end of the second shaft, and the pushing block, compression spring and positioning block are located between the second connecting plate and the limiting nut.

3. The wheelchair electric tractor lifting mechanism as described in claim 1, wherein: The pushing block has a first stepped surface, the positioning block has a second stepped surface, and the two ends of the compression spring abut against the first stepped surface and the second stepped surface, respectively.

4. The electric wheelchair lift mechanism as described in claim 1, wherein: It also includes a bearing, which is mounted on the second connecting plate, and the middle part of the second shaft is rotatably connected to the bearing.

5. The electric wheelchair lift mechanism as described in claim 1, wherein: The third connecting plate is provided with a guide groove. When the first shaft is engaged with the mating part, the guide groove extends in an arc shape around the first shaft. The second shaft is used to limit the guide groove so as to slide along the extension path of the guide groove. One end of the extension of the guide groove is provided with a second sliding outlet for the second shaft to slide in and out. The second sliding outlet and the first sliding outlet face different directions.

6. The electric wheelchair tractor lifting mechanism as described in claim 1, wherein: The locking assembly includes a pin and a pin seat. A first connecting plate or a second connecting plate is used to install the pin seat or to open a limiting hole. A third connecting plate is used to open a limiting hole or to install the pin seat. When the tractor unit rotates, the pin deviates from or aligns with the limiting hole. When the pin aligns with the limiting hole, the rotation of the tractor unit is locked by pushing the pin outward into the limiting hole. When the pin is inserted into the limiting hole, the rotation of the tractor unit is unlocked by pulling the pin inward out of the limiting hole.

7. The electric wheelchair tractor lifting mechanism as described in claim 6, wherein: It also includes an elastic element and a pull wire. The elastic element is placed between the pin and the pin seat to push the pin outward, and one end of the pull wire is connected to the tail of the pin for pulling the pin inward.

8. The electric wheelchair lift mechanism as described in claim 7, wherein: It also includes a locking handle, which includes a fixed base and a pull cable. The fixed base is mounted on the handlebars of the electric tow truck, and the pull cable is movably mounted on the fixed base and connected to the other end of the pull cable.

9. The electric wheelchair lift mechanism as described in claim 8, wherein: It also includes a flexible sleeve, one end of which is connected to the tail of the pin, the other end of which is inserted into the flexible sleeve, the other end of which is connected to the fixed base, and the other end of which is inserted out of the flexible sleeve and connected to the pull wire part.

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