Dumbwaiter lift; service lift Also known as the vegetable elevator, food ladder, dining ladder or multi-purpose debris elevator.
A fixed lifting device that serves a specified floor (generally up to eight floors). It has a car that is not allowed to enter the car in terms of its size and construction. The car runs between two columns of rigid rails with a vertical tilt angle of less than 15°.  In order to meet the conditions for non-entry, the car size must not exceed:
(a) Floor area: 1.0 square meter
(b) Depth: 1.0 m
(c) Height: 1.20 meters
(d) Load: 100-300 kg
It has the characteristics of small size, full function, stable transportation and low price. It is widely used in restaurant canteens to transport meals and factories, libraries and other transportation debris. Nowadays, it is roughly divided into two types according to the use mode, computer controlled and PLC control. According to the working mode, it is divided into work table and floor type, and its speed ranges from 0.4 meters to 1.0 meters. Now, for the convenience of installation, the frame type is used. This structure has the advantages of convenient installation, small space, and no Use a dedicated hoistway.
It is used to transport small books such as books and food, and is suitable for canteens, restaurants, nurseries, libraries, etc.
(1) The elevator pair should be installed in the same hoistway as the car.
(2) The elevator shaft is generally completely enclosed by a non-porous wall, floor and ceiling. Only the following openings are allowed:
(1) landing door;
(2) Inspection doors, trap doors, and cleaning doors;
(3) Exhaust holes for exhausting gases and fumes in case of fire;
(4) A permanent opening between the shaft and the machine room (hood) or between the pulleys.
(3) When the hoistway is not required to prevent the spread of fire to protect the building, and the hoistway is not required to be completely enclosed, the height of the other walls except the entrance surface is not less than 2.5 m. At the entrance face of the hoistway, a grid or perforated plate can be used from a height of 2.5 m above the landing floor. The dimensions of the mesh or perforated plate holes are no more than 75 mm, measured either horizontally or vertically.
(4) The machine room door shall not be less than 0.6m×0.6m at any time, and the door shall be able to lock.
(5) A non-porous landing door shall be installed at the opening of the hoistway facing the entrance of the car. When the door is closed, the gap between the door leaves or between the door leaf and the column, the sill or the sill should be as small as possible, no more than 6mm.
(6) If there is an empty layer below the elevator, a safety gear device should be placed on the car. 
(7) The elevator drive mainframe and its ancillary equipment should be placed in a separate machine room or placed in a hood in the elevator shaft that allows only authorized personnel to enter (or approach).
(8) The machine room or hood should have a strong structure, can adapt to various weather conditions, and should be dry, and at the same time, have good ventilation conditions. Personnel should be safe when approaching all equipment.
(9) Parameters and dimensions of debris elevator