Patent CA-3159030-A1 (CA)
Inventor: DELIA ARNAUD
IPC: B25J15/04
Filed: 2022-05-17
Abstract: The invention provides locking/ unlocking mechanism between a semi-automated tool changer and a tool adapter in order to permit a robotic arm to swap between end effectors during coded script (instruction) runs. Definitions An End Effector is defined herein as follows; In robotics, an End Effector is a device at the end of a robot arm, which is designed to interact with the environment. The exact nature of this device depends on the application of the robot, Ref. Wikipedia. Common example of end effectors is, mechanical gripper, suction cups, magnets, small drill, and hooks. A semi-automated tool changer is defined herein as follows; Device that allows changing from different tool adapter by mating and locking or unlocking with it. This can be achieved via coded script (instructions) sent to the robot arm. A tool adapter is defined herein as follows; Device that mates with the tool changer and which is also able via fasteners or other means to secure with the End Effector. Background of the Invention Field of invention The invention pertains to small desktop robotic arms (average total length around 26 in). Since the common accessibly of microchips boards (I.e., Arduino or Raspberry PI), the robotic field have seen an increase of simple but yet precise and reliable desktop robotic arms. Dorna Robotics, Rotrics and Dobot are just a few Company names which manufacture such desktop robotic arms. Thus, it is now accessible for hobbyist, small compagnies or for educational purposes to purchase a capable robot arm at a fraction of the costs that would have been paid to purchase an industrial robot arm. lon.3 As demonstrated by the field of industrial robots, the ability to change from different end effectors during coded script runs using a semi-automated tool changer is tremendously practical and cuts down on End Effector (tool) changing time. However, due to the fact that the semi-automated tool changers were created to cater the industrial robotics. All the available semi-automated tool changer on the market is bulky and requires complicated compressed air setting in order to operate, thus, making them unpractical for usage on a desk at home, in a classroom or at in a small-scale manufacturing line. The common mechanics of an industrial semi-automated tool changer makes the use of air pressure (compressed air) to push steel balls in grooves which creates an interference between the tool changer and the tool adapter, hence, effectively locking the tool changer to the tool adapter. Lt autotools, ATI  Industrial Automation, 4TECH Robotics are examples of companies manufacturing these types of industrial semi-automated tool changer. The invention proposed herein simplifies the locking and unlocking operation of such semi-automated tool changer without sacrificing on reliability and precision. The invention will prove useful for all tending machine tasks associated with desktop robot arms where the robot arm would require frequent change of end effector to perform the task at hand. 2of13 Summary of Invention The invention uses a Radio Control (RC) micro servo to lock or unlock the semi-automated Tool Changer with the Tool Adapter, enabling a robot arm (or other) to easily change End Effectors within its coded script. As a RC  micro servo is used to lock/ unlock with the Tool Adapter only a PWM  (Pulse Width Modulation) input is required to rotate the micro servo arm, I.e., 20  clockwise to lock and 20  anti-clockwise to unlock. By design the locking mechanism does not load the servo. The load, i.e., weight of the tool adapter (with attached End Effector) is taken by the (4x) arms (Part #4, Figure 3) engaging (4) four slots of the Tool Adapter.  Therefore, the PWM input needed to rotate the servo arm does not have to stay active (high) at all times. PWM input are only required to rotate the micro servo arm (I.e., lock or unlock with the Tool Adapter). Consequently, protecting the Micro Servo from overloading and overheating. The invention has three (3) inputs; -    One PWM inputs to control the Micro Servo Position. -    Two miscellaneous inputs. These inputs can be used to send PWM inputs to the tool adapter or send a 12 to 24-volt DC current to the tool adapter, as required by End Effector used. 3of13