A dumbwaiter is a small freight elevator or lift intended to carry food. Dumbwaiters found within modern structures, including both commercial, public and private buildings, are often connected between multiple floors. When installed in restaurants, schools, hospitals, retirement homes or private homes, they generally terminate in a kitchen. [1] [2]
The term seems to have been popularized in the United States in the 1840s, after the model of earlier "dumbwaiters" now known as serving trays and lazy Susans. [3] The mechanical dumbwaiter was invented by George W. Cannon, a New York City inventor. He first filed for the patent of a brake system (US Patent no. 260776) that could be used for a dumbwaiter on January 6, 1883, [4] then for the patent on the mechanical dumbwaiter (US Patent No. 361268) on February 17, 1887. [5] He reportedly generated vast royalties from the patents until his death in 1897. [6]
A simple dumbwaiter is a movable frame in a shaft, dropped by a rope on a pulley, guided by rails; most dumbwaiters have a shaft, cart, and capacity smaller than those of passenger elevators, usually 45 to 450 kg (100 to 992 lbs.) [2] Before electric motors were added in the 1920s, dumbwaiters were controlled manually by ropes on pulleys. [1]
Early 20th-century building codes sometimes required fireproof dumbwaiter walls and self-closing fireproof doors, and mention features such as buttons to control movement between floors and locks to prevent doors from opening unless the cart is stopped at that floor. [7] Dumbwaiter lifts in London were extremely popular in finer homes. Maids used them to deliver laundry to the laundry room, making it unnecessary to carry dirty laundry through the house, saving time and preventing injury. [8]
A legal complaint about a Manhattan restaurant's dumbwaiter in 1915—which also mentioned that food orders were shouted up and down the shaft—described its operation and limitations:
[There is] ... great play between the cart of the dumb-waiter and the guides on which it runs, with the result that the running of the cart is accompanied by a loud noise. The rope which operates the cart of the dumb-waiter runs in a wheel with a very shallow groove, so that the rope is liable to and does at times slip off. ... The cart has no shock absorbers at the top, so that when it strikes the top of the shaft or wheel there is a loud report. ... [T]he ropes of the dumb-waiter strike such wall at frequent intervals with a loud report. ... [T]he dumb-waiter is often negligently operated, by running it faster than necessary, and by letting it go down with a sudden fall. [9]
More recent dumbwaiters can be more sophisticated, using electric motors, automatic control systems, and custom freight containers characteristic of other kinds of elevators. [10] Recently constructed book lifts in libraries and mail or other freight transports in office towers may be larger than many dumbwaiters in public restaurants and private homes, supporting loads as heavy as 450 kg (1000 lbs).[ citation needed ]
Building codes have regulated the construction and operation of dumbwaiters in parts of North America since the 19th century. [2] Modern dumbwaiters in the United States and Canada must comply[ citation needed ] with American Society of Mechanical Engineers (ASME) codes and, therefore, have features similar to those of passenger elevators. [11] The construction, operation and usage of dumbwaiters varies widely according to country.
Margaret Bayard Smith wrote that former U.S. President Thomas Jefferson had kept dumbwaiters at both the White House and his Monticello estate whenever she visited him at both places. [12] She also wrote that these dumbwaiters were built to reduce the number of servants required near dining rooms, allowing more privacy in conversations which might include sensitive information. [12]
After defecting from the Soviet underground in 1938, Whittaker Chambers gave a stash of stolen documents to his nephew-in-law, Nathan Levine, who hid them in a dumbwaiter in his mother's house in Brooklyn. A decade later, Chambers asked his nephew to retrieve them (which Chambers referred to as his "life preserver"). Handwritten and typewritten papers therein came from Alger Hiss and Harry Dexter White (and became known as the "Baltimore Documents"). Microfilm contained therein was subpoenaed and sensationalized (misnamed the "Pumpkin Papers" in the press) by Richard M. Nixon for HUAC. [13]
A funicular is a type of cable railway system that connects points along a railway track laid on a steep slope. The system is characterized by two counterbalanced carriages permanently attached to opposite ends of a haulage cable, which is looped over a pulley at the upper end of the track. The result of such a configuration is that the two carriages move synchronously: as one ascends, the other descends at an equal speed. This feature distinguishes funiculars from inclined elevators, which have a single car that is hauled uphill.
The Dumb Waiter is a one-act play by Harold Pinter written in 1957.
A paternoster or paternoster lift is a passenger elevator which consists of a chain of open compartments that move slowly in a loop up and down inside a building without stopping. Passengers can step on or off at any floor they like. The same technique is also used for filing cabinets to store large amounts of (paper) documents or for small spare parts. The much smaller belt manlift, which consists of an endless belt with steps and rungs but no compartments, is also sometimes called a paternoster.
The American Society of Mechanical Engineers (ASME) is an American professional association that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via "continuing education, training and professional development, codes and standards, research, conferences and publications, government relations, and other forms of outreach." ASME is thus an engineering society, a standards organization, a research and development organization, an advocacy organization, a provider of training and education, and a nonprofit organization. Founded as an engineering society focused on mechanical engineering in North America, ASME is today multidisciplinary and global.
Book the Sixth: The Ersatz Elevator is the sixth novel of the children's novel series A Series of Unfortunate Events by Lemony Snicket. The Baudelaires are sent to live with the wealthy Esmé and Jerome Squalor.
A clothes line, also spelled clothesline, also known as a washing line, is a device for hanging clothes on for the purpose of drying or airing out the articles. It is made of any type of rope, cord, or twine that has been stretched between two points, outdoors or indoors, above ground level. Clothing that has recently been washed is hung over the line to dry, held in place using clothes pegs or clothespins. Washing lines are attached either from a post or a wall, and are frequently located in back gardens, or on balconies. Longer washing lines often have props holding up the mid-section so the weight of the clothing does not pull the clothesline down to the ground.
A belt is a loop of flexible material used to link two or more rotating shafts mechanically, most often parallel. Belts may be used as a source of motion, to transmit power efficiently or to track relative movement. Belts are looped over pulleys and may have a twist between the pulleys, and the shafts need not be parallel.
A lazy Susan is a turntable placed on a table or countertop to aid in distributing food. Lazy Susans may be made from a variety of materials but are usually glass, wood, or plastic. They are circular and placed in the centre of a table to share dishes easily among diners. Owing to the nature of Chinese cuisine, especially dim sum, they are common at formal Chinese restaurants both in mainland China and abroad. In Chinese, they are known as 餐桌转盘 or "dinner-table turntables".
A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium. The most familiar form is an elevator, the car of which is raised and lowered by a hoist mechanism. Most hoists couple to their loads using a lifting hook. Today, there are a few governing bodies for the North American overhead hoist industry which include the Hoist Manufactures Institute, ASME, and the Occupational Safety and Health Administration. HMI is a product counsel of the Material Handling Industry of America consisting of hoist manufacturers promoting safe use of their products.
1 Wall Street Court is a residential building in the Financial District of Manhattan in New York City, United States. The 15-story building, designed by Clinton and Russell in the Renaissance Revival style, was completed in 1904 at the intersection of Wall, Pearl, and Beaver Streets.
Comedy of menace is the body of plays written by David Campton, Nigel Dennis, N. F. Simpson, and Harold Pinter. The term was coined by drama critic Irving Wardle, who borrowed it from the subtitle of Campton's play The Lunatic View: A Comedy of Menace, in reviewing Pinter's and Campton's plays in Encore in 1958.
John Fowler was an English agricultural engineer who was a pioneer in the use of steam engines for ploughing and digging drainage channels. His inventions significantly reduced the cost of ploughing farmland, and also enabled the drainage of previously uncultivated land in many parts of the world.
A jackshaft, also called a countershaft, is a common mechanical design component used to transfer or synchronize rotational force in a machine. A jackshaft is often just a short stub with supporting bearings on the ends and two pulleys, gears, or cranks attached to it. In general, a jackshaft is any shaft that is used as an intermediary transmitting power from a driving shaft to a driven shaft.
A Z-Drag or Z-Rig is an arrangement of lines and pulleys, effectively forming a block and tackle, that is commonly used in rescue situations. The basic arrangement results in pulling the hauling end 3 times the distance the load is moved, providing a theoretical mechanical advantage of three to one. In actual practice the advantage will be reduced by friction in the pulleys or carabiners. The advantage will also be reduced if the pull on the hauling end is not parallel to the direction the load moves in. The name comes from the fact that the arrangement of lines is roughly Z-shaped. Besides the mechanical advantage to pulling, it also uses only part of the total length of the rope for the block and tackle arrangement.
An elevator or lift is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems such as a hoist, although some pump hydraulic fluid to raise a cylindrical piston like a jack.
A differential pulley —also called "Weston differential pulley", sometimes "differential hoist", "chain hoist", or colloquially "chain fall"— is used to manually lift very heavy objects like car engines. It is operated by pulling upon the slack section of a continuous chain that wraps around two pulleys on a common shaft. The relative sizing of the two connected pulleys determines the maximum weight that can be lifted by hand. If the pulley radii are close enough, then the load will remain in place until the chain is pulled.
David Wilkinson was a U.S. mechanical engineer who invented a lathe for cutting screw threads, which was extremely important in the development of the machine tool industry in the early 19th century.
An escalator is a moving staircase which carries people between floors of a building or structure. It consists of a motor-driven chain of individually linked steps on a track which cycle on a pair of tracks which keep the step tread horizontal.
George W. Cannon was an American inventor from New York. He is best known for the invention of the mechanical dumbwaiter. Cannon first filed for the patent of a brake system that could be used for a dumbwaiter on January 6, 1883. He later filed for the patent on the mechanical dumbwaiter on February 17, 1887. He is reported to have generated a vast amount of money from royalties from his dumbwaiter patents until his death in 1911.
Jesse Merrick Smith was a prominent American mechanical engineer, consulting engineer, patent expert, and president of the American Society of Mechanical Engineers in the year 1909-10.
dumbwaiter.Limited Preview, Google Books , accessed August 26, 2008.
Cases argued and determined in the Court of Appeals, Supreme and lower courts of record of New York State, with key number annotations.Via Google Books. (Original from the University of California. Digitized August 3, 2007.)