1303-D05A & 1304-D57A Manual - 95575 Rev 05
5
2 System Description
Definitions
Tool
–
A device that may be attached to a tool changer to perform a specific function
Tool Changer
–
A device consisting of two adapters, one attached to a robot and one attached to a tool, that
mechanically couple a robot to a tool, allowing a robot to use multiple tools. As a result, a single robot can per-
form multiple functions.
Tool Stand
–
A device that holds a tool mounted to a tool adapter for later use, as the robot performs other
tasks. A Tool Stand is the safe area for the tool changer to drop off and pick up tools.
Couple –
The action of moving the cams outward on the robot adaptor so the tool adaptor will connect.
Uncouple –
The action of moving the cams inward on the robot adaptor so the tool adaptor will disconnect.
Safety Function
The reason for a Tool Changer Safety Circuit is to ensure an uncouple signal cannot be applied to the
tool changer while it is not in a safe condition. A safe condition is defined as a tool changer engaged in a tool
stand or in movement without a tool attached to the tool changer. To uncouple, a piston retracts three cams in
the tool changer. It’s this action, if not performed under safe conditions, which can cause injury to a person.
Functional Description
With air on, the tool changer not in a tool stand, and with a tool present, the robot may be moved to
perform tasks. If air is lost to the valves, the tool will remain coupled, as mechanical safety mechanisms in the
robot adaptor prevent uncoupling. The Tool Changer should never be operated without air supplied and, it is the
customers responsibility to make sure the correct air pressure is always being supplied during operation.
When the tool changer needs to be uncoupled, a signal must be sent through two sets of contacts driv-
en by a force guided relay. The solenoid of the two sets of relays are driven by the tool stand present switch and
tool present switch. When the tool stand present switch is actuated, it is safe to couple and uncouple, because
this indicates that the tool has been docked in, and supported by the tool stand. The tool present switch
is to
indicate if a tool adapter is coupled to the robot adapter. A tool changer is free to couple and uncouple at any
point if a tool is not present.
After the two uncouple signals are applied and allowed to pass through the safety logic (see Section 3
Stage Diagram). The coils of two independent valves will be powered, causing the tool changer to uncouple.
Both valves are pneumatically interlocked, this means both valves have to be actuated in order to achieve an
uncoupled state.
Once a channel has allowed a valve solenoid to be powered, the channel will be latched in the uncou-
pled state, and as long as an uncouple signal is being applied, that channel will remain latched. This is to pre-
vent any recoupling action while the robot side is separated from the tool side.
