A Westclox “Big Ben” alarm clock is used for the opening establishing shot in the I Love Lucy Series 2  episode No Children Allowed.  The time is 2:40 am and an exhausted Lucy is up trying to calm her crying baby.

The logo is clearly visible in the first scene -the words Westclox Big Ben can be seen on the dial.   Later the clock appears again to show the time is now 3:00 am but now the Logo is covered. as seen in the screen capture below.

Thanks to Jamie for the ID