TileEntityConveyor

public class TileEntityConveyor extends TileEntity {

    public final float speed;

    public TileEntityConveyor(float speed) {
        this.speed = speed;
    }

    @Override
    public void updateEntity() {
        List<Entity> entities = worldObj.getEntitiesWithinAABB(Entity.class,
                AxisAlignedBB.getBoundingBox(xCoord, yCoord + 0.1, zCoord,
                        xCoord + 1.0, yCoord + 1.0, zCoord + 1.0));

        int meta = worldObj.getBlockMetadata(xCoord, yCoord, zCoord);

        for (Entity e : entities) {
            if (meta == 2) {
                e.setVelocity(e.motionX, e.motionY, -speed);
            }
            if (meta == 3) {
                e.setVelocity(e.motionX, e.motionY, speed);
            }
            if (meta == 4) {
                e.setVelocity(-speed, e.motionY, e.motionZ);
            }
            if (meta == 5) {
                e.setVelocity(speed, e.motionY, e.motionZ);
            }
        }
    }

}