Mechanical arm
A mechanical arm designed to provide automated garbage collection with smooth, constant movement (i.e. movement that has minimal jerk/shock) thereby resulting in limited shock stress on the components and leading to high durability. The mechanical arm including a horizontal displacement system having a plurality of sections rollingly engaged to one another and a motor mounted to an immobile section for drivingly extending section in a generally horizontal orientation, a vertical displacement system having a plurality of masts rollingly engaged to one another and a motor mounted to a first mast for drivingly extending a second mast in a generally vertical orientation, and/or a grabber system having a plurality of fingers mounted to a frame and operated by a single motor.
1 . A mechanical arm of a garbage truck, the mechanical arm comprising:
a first mast;
a second mast engaged to the first mast and movable relative to the first mast in a direction being substantially perpendicular to a ground surface;
at least two sprockets pivotally mounted on the first mast, wherein the at least two sprockets comprise two first sprockets pivotally mounted on the first mast;
two second sprockets pivotally mounted on the second mast;
a first chain forming a closed loop extending around the at least two sprockets, the first chain engaged to the second mast;
a second chain looped around the two second sprockets;
a grabber system mounted to the second mast, the grabber system having at least two actuated fingers for holding a bin to be discharged in the garbage truck, wherein the first chain is engaged to the grabber system via the second chain; and
a motor drivingly engaged to the second mast via the first chain and operable to move the second mast and the grabber system relative to the first mast between a low position and a high position, a height of the grabber system greater in the high position than in the low position,
wherein the motor is mounted to the first mast and remains substantially at a constant height between the low and high positions of the second mast.
2 . The mechanical arm of claim 1 , wherein the second chain is fixed to the first mast at a first location and fixed to the grabber system at a second location, the first location located on a first vertically oriented span of the second chain, and the second location located on a second vertically oriented span of the second chain, such that a first movement of the first location relative to the second mast in a first direction translates into a second movement of the second location relative to the second mast in a second direction opposite the first direction.
3 . The mechanical arm of claim 2 , further comprising a mounting member secured to the first chain, wherein the second chain is fixed to the first mast at the first location via the mounting member.
4 . The mechanical arm of claim 3 , wherein the mounting member comprises a bracket.
5 . The mechanical arm of claim 3 , further comprising biasing members that connect the mounting member to the first chain.
6 . The mechanical arm of claim 1 , wherein the motor is a first motor, and wherein the mechanical arm further comprises a horizontal displacement system comprising:
a proximal arm section securable to a frame of the garbage truck;
a distal arm section engaged to the proximal arm section and movable relative to the proximal arm section in a direction being substantially parallel to a ground surface; and
a second motor drivingly engaged to the distal arm section and operable to move the distal arm section relative to the proximal arm section between a retracted configuration in which the proximal and distal arm sections overlap one another and an expanded configuration in which at least a portion of the distal arm section is offset from the proximal arm section,
wherein the second motor is mounted to the proximal arm section and remains immobile relative to the frame of the garbage truck between the retracted configuration and the expanded configuration.
7 . The mechanical arm of claim 6 , wherein:
the proximal arm section defines a first aperture;
the distal arm section defines a second aperture;
when the distal arm is in the retracted configuration, the first and second apertures are coaxially aligned; and
the horizontal displacement system further comprises a locking device configured to, when the distal arm section is in the retracted configuration, transition between a locked state and an unlocked state, wherein the locking device is configured to transition to the locked state by moving a locking bar into the coaxially aligned first and second apertures, and wherein the locking device is configured to transition to the unlocked state by removing the locking bar from the coaxially aligned first and second apertures.
8 . The mechanical arm of claim 6 , wherein the first mast is fixedly attached to the distal arm section of the horizontal displacement system.
9 . The mechanical arm of claim 1 , wherein:
the two first sprockets pivotally mounted on the first mast comprise:
a driving sprocket positioned at a vertical lower end of the first mast; and
a driven sprocket positioned at a vertical upper end of the first mast; and
the motor is mounted to the first mast proximate the driving sprocket.
10 . The mechanical arm of claim 9 , further comprising:
a gearbox drivingly engaged by the motor, wherein the driving sprocket is drivingly engaged by the motor via the gearbox.
11 . The mechanical arm of claim 10 , wherein the driving sprocket, the gearbox, and the motor are horizontally arranged along a rotational axis of the driving sprocket.
12 . The mechanical arm of claim 9 , wherein the at least two sprockets pivotally mounted on the first mast further comprise a tensioning sprocket and an idler sprocket that are configured to maintain tension in the first chain.
13 . The mechanical arm of claim 12 , wherein:
the tensioning sprocket and the idler sprocket mesh with the first chain; and
the closed loop formed by the first chain further extends around the tensioning sprocket and the idler sprocket.
14 . The mechanical arm of claim 13 , wherein each of the tensioning sprocket and the idler sprocket is respectively positioned closer to the driving sprocket than its respective position relative to the driven sprocket.
15 . A horizontal displacement system for a mechanical arm of a garbage truck, the horizontal displacement system comprising:
a proximal arm section securable to a frame of the garbage truck, the proximal arm section defining a first aperture;
a distal arm section engaged to the proximal arm section and movable relative to the proximal arm section in a direction being substantially parallel to a ground surface, the distal arm section defining a second aperture;
a motor drivingly engaged to the distal arm section and operable to linearly move the distal arm section relative to the proximal arm section between a retracted configuration in which the proximal and distal arm sections overlap one another such that the first and second apertures are coaxially aligned, and an expanded configuration in which at least a portion of the distal arm section is offset from the proximal arm section, the linear movement translating the second aperture relative to the first aperture in the direction substantially parallel to the ground surface; and
a locking device configured to, when the distal arm section is in the retracted configuration, transition between a locked state and an unlocked state,
wherein the locking device is configured to transition to the locked state by moving a locking bar into the coaxially aligned first and second apertures, and
wherein the locking device is configured to transition to the unlocked state by removing the locking bar from the coaxially aligned first and second apertures.
16 . The horizontal displacement system of claim 15 , wherein the motor is mounted to the proximal arm section and remains immobile relative to the frame of the garbage truck between the retracted configuration and the expanded configuration.
17 . The horizontal displacement system of claim 15 , further comprising an intermediate arm section defining a third aperture, wherein, when the distal arm section is in the retracted configuration, the proximal, distal, and intermediate arm sections overlap one another such that the first, second, and third apertures are coaxially aligned.
18 . The horizontal displacement system of claim 15 , further comprising an actuator selected from the group consisting of: a linear actuator, a solenoid, a pneumatic actuator, and a hydraulic actuator.
19 . The horizontal displacement system of claim 18 , wherein the locking device further comprises a lever comprising a first portion pivotally connected to the actuator and a second portion pivotally connected to the locking bar.
20 . The horizontal displacement system of claim 15 , wherein the locking device further comprises a wearing ring configured to be secured to the locking bar via a clip.