Wheel assembly with sensor for measuring wheel movement

A materials handling vehicle comprising:

• a power unit;
• a mast assembly secured to the power unit;
• a pair of forks coupled to the mast assembly, the forks being movable in height between a lowered position and a plurality of raised positions;
• and
• a pair of outrigger arm assemblies secured to the mast assembly, each outrigger arm assembly comprising:
• a frame member secured to the mast assembly;
• an axle fixed to the frame member;
• a wheel rotatably mounted to the axle, wherein the wheel comprises a wheel recess;
• a code ring located within the wheel recess for rotation with the wheel;
• and
• a sensor device coupled to the frame member and located adjacent to the code ring, wherein the sensor device senses movement of the code ring and generates an output signal indicative of movement of the wheel, and wherein:
• the frame member comprises opposing axle plates for supporting the axle, each of the opposing axle plates comprising a bore formed therethrough for receiving the axle;
• one of the opposing axle plates comprises a further bore through which a portion of the sensor device at least partially extends;
• and
• the outrigger assembly further comprises a side member that is coupled to an outer surface of the one axle plate and is configured to receive the sensor device.