George W. Cannon, a New York based inventor, first filed the patent of a brake system (no. 260776 US) on 6th January 1883 which was the prototype of mechanical Dumbwaiter for which he filed another patent (no. 361268 US) on 17th February 1887. Also known as Lazy Susan in the US and Canada the Dumbwaiter meaning the silent waiter is a movable shelved frame in a shaft that can transport materials ranging typically from 45 to 450 Kg across the various floors of an establishment in the vertical manner when it is operated manually with the aid of a rope on pulley as in earlier days or by electric motors as is the case now.(More Details: Dumbwaiter Lift For Office)
The advantage of the electrical dumbwaiter is that it saves up to 80% of manual effort over a mechanical counterpart.A dumbwaiter can have either of the following loading mechanisms viz.Table Loading: This is mostly seen to be used in domestic establishments or institutes like libraries or restaurants etc.Floor Loading: This is mostly used in institutions where the transportable materials are much heavier.
To load the dumbwaiter the opening doors can be at the front or multiple doors at right angle or it can have a through opening. It depends upon the requirement whether simultaneous multiple access facilities are to be performed or not.The speed of a dumbwaiter varies between 15 m/min to 45 m/min typically.(More Details: Kitchen Dumbwaiter LIfts)
Singapore has a huge base for the businesses involving Dumbwaiters owing to the fact that it is one of the biggest industrial hubs of Asia. In Singapore one of the various popular types of dumbwaiters is the Marine dumbwaiter that is used in underwater freight systems. Among the major companies producing the instrument within the ambit of the territory are Mr. Dumbwaiter, Master Engineering, FB Industries, HIN CHONG Engineering Constructions, KEN-JO Industries, LIFT-MECH Engineering etc. US elevator companies like OTIS also have a substantial customer base in Singapore.