Hydraulic elevator without a machineroom

Abstract: A hydraulic elevator system having a configuration without a machineroom is disclosed. The hydraulic elevator system includes a valve assembly (46) that is separated and remotely located from the pump and fluid tank (22). This arrangement permits the valve assembly and an electronic controller (48) to be located in a cabinet (50) outside of the hoistway (29), and the other hydraulic components, such as the tank and pump, to be located in the hoistway.

Description: The present invention relates to hydraulic elevators. Conventional hydraulic elevators include a hydraulically driven ram to raise an elevator car. Lowering of the car is typically accomplished by permitting fluid to exit the cylinder of the hydraulic ram and using the weight of the car to force the fluid out of the cylinder. The piston may be directly engaged with the car or may be engaged with the car via a rope fixed to the hoistway and engaged with a sheave on a yoke on the piston. The latter arrangement provides the benefit of not requiring a hole under the hoistway to receive the hydraulic cylinder. One advantage of hydraulic elevators as compared to traction elevators is the lower cost of the installation. Another traditional advantage is that the machineroom for the hydraulic elevator may be located anywhere in the building, rather than above the hoistway as in traditional traction elevators. Even though the machineroom for a hydraulic elevator may be remotely located, it is still necessary to provide such a space in order to provide a closed and protected area for the hydraulic components: the fluid tank, the pump (typically submerged in the tank of fluid), and the valves associated with the pump and tank. In addition, the machineroom includes a controller that includes the various electrical components for the hydraulic elevator system. An elevator system having the feature, as set forth in the preamble of claim 1 is known from SE-B-332698. According to the present invention, there is provided a elevator system having a car movable within a hoistway, the system including a hydraulic cylinder, a fluid tank, a pump for moving fluid between the tank and cylinder, and a valve block that controls the flow of fluid between the tank and cylinder, the pump and the value block operating to transfer fluid to or from the cylinder to raise or lower the car during operation of the hydraulic elevator system wherein the valve block is located remotely from the tank and the pump. As a result of having the valve block separate from the pump and tank, the necessity for a machineroom is eliminated. The pump and tank may be located in the hoistway and the valve block may be located in a cabinet along with various electronic components of the hydraulic elevator system. The cabinet may be conveniently positioned adjacent to a landing so that a mechanic will have access to the valve block and electronic control without having to enter the hoistway. According to a particular embodiment, the hydraulic elevator system includes a car and a hydraulic cylinder positioned adjacent to the travel path of the car and mounted on a support, and wherein the pump and tank are positioned underneath the support. This arrangement of the cylinder, pump and tank provides a compact configuration that minimizes the space requirements of the hoistway. According to a further particular embodiment, the cylinder includes a sheave engaged with a rope, wherein the rope is attached to the car by a rope hitch, and wherein the rope hitch is disposed on the car in a position to avoid interference when the car is adjacent to the tank and pump. This particular embodiment provides a configuration that permits the use of a roped hydraulic elevator without a machineroom. An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which:- Fig. 1 is an illustration of a hydraulic elevator system according to the present invention; and Fig. 2 is an illustration of cabinet housing a valve assembly and electronic controller. Illustrated in Fig: 1 is a hydraulic elevator system 12 which includes a car 14 engaged with a pair of guide rails 16, a hydraulic cylinder 18 having a piston 20, a fluid tank 22 having a pump 24 disposed within the tank 22, and a plurality of ropes 26. The ropes 26 have one end attached to the car 14 by a rope hitch 28 and the opposite end anchored in the hoistway 29. The ropes 26 extend over a sheave 30 mounted on the upper end of the piston 20. Movement of the piston 20 is guided by a yoke 32 engaged with the pair of guide rails 16. During operation, the piston 20 moves within the cylinder 18 and causes the sheave 30 to raise and lower within the hoistway 29. Movement of the sheave 30 causes the car 14 to raise and lower in the hoistway 29 via the engagement with the ropes 26. The cylinder 18 includes a cylinder stand 34 that is mounted on a support assembly 36 positioned between the guide rails 16. The support assembly 36 includes a horizontal support 38, formed from a conventional I-beam structure, and a pair of vertical uprights 40 that are adjacent to the pair of guide rails 16 and are supported by the bottom or pit 42 of the hoistway 29. In addition to supporting the cylinder 18, the horizontal support 38 also provides an anchor point 44 for the ropes 26. As a result of the support assembly 36, the cylinder 18 is raised above or off-set from the pit 42. The integral tank 22 and pump 24 are disposed in the opening defined by the support assembly 36. The tank 22, which contains the fluid (typically oil) used in the hydraulic system, extends to fill the space between the uprights 40 and the support 38. The pump 24 is internal to the tank 22 and submerged in the fluid. As a result of not integrating a valve block and various other valve components to the tank 22 and pump 24, the size of the tank 22 is minimized and may be proportioned to fit in the available space. The cylinder 18, support assembly 36, guide rails 16, tank 22 and pump 24 are all positioned along one side of the travel path of the car 14. During travel through the hoistway 29, the car 14 may be adjacent to one or more of the components in the hoistway 29. In order to avoid interference between the hoistway components and the ropes 26 and rope hitch 28, the rope hitch 28 is positioned at the top of the car 14. In a typical roped hydraulic elevator, the ropes are hitched or engaged with the bottom of the car to maximize the rise of the car. In the configuration according to the present embodiment, the off-set produced by the support assembly 36 increases the rise of the car 14 and therefore the ropes 26 may be engaged or hitched to the top of the car 14 without significantly affecting the rise of the car 14. The flow of fluid between the tank 22 and cylinder 18 is controlled by a control valve assembly 46 and an electronic controller 48. These devices 46,48, as shown in Fig. 2, are located in a cabinet 50 positioned adjacent to one of the landings of the hoistway 29. Access to the control valve assembly 46 and controller 48 is through a locked door 52. The door 52 is locked to prevent unauthorized access to the controller 48 and the control valve assembly 46. The electronic controller 48 is in the upper part of the cabinet 50 and the control valve assembly 46 in is the lower part of the cabinet. This particular arrangement takes advantage of the height of the cabinet 50, and the possibility to separate the electronic controller 48 into components that may be mounted in the cabinet 50 or on the door 52, in order to minimize the space requirements of the cabinet 50. Although shown in Fig. 2 as being adjacent to a landing, it should be noted that the cabinet 50 may be located in other convenient locations. In addition, the cabinet 50 may be separated into two or more cabinets. I n this configuration, the electronic controller 48 may be separated from the control valve assembly 46, if desired. Further, the controller and control valve assembly, including the valve block, may be separated into multiple modules, with each module conveniently located. The control valve assembly 46 includes a valve block 54, a muffler 56 and a manually operable release mechanism 58. The control valve assembly 46 is in fluid communication with the tank 22 by a plurality of fluid lines 60. The valve block 54 includes various valve stems and channels that control the flow of fluid between the cylinder 18 and pump 24 using conventional valve technology. The muffler 56 regulates the fluid flow from the valve block 54 to the cylinder 18. The release mechanism 58 permits a mechanic to manually open the valves to flow fluid from the cylinder 18 and into the tank 22. The manual operation of the valves may be used during emergency operations to lower the car 14 and evacuate passengers. Although shown and described as a manually operable mechanism 58, other mechanisms may be used, such as electrically controllable actuators connected to a back-up power supply. During operation of the hydraulic elevator system 12, passengers place car calls and hall calls that are registered through the electronic controller 48. The electronic controller 48 signals the pump 24 and valve block 54 to operate in the desired manner to transfer fluid to or from the cylinder 18 and to raise or lower the car 14. If service of the hydraulic elevator system 12 is required, a mechanic may get access to both the controller 48 and the valve block 54 by unlocking the cabinet 50. Locating the cabinet 50 with the controller 48 and valve block 54 near a landing facilitates the maintenance of the hydraulic elevator system 12. In addition, in the event of an emergency, the mechanic may get access to the manual release mechanism 58 through the cabinet 50.

Claims: A hydraulic elevator system having a car (14) movable within a hoistway (29), the system including a hydraulic cylinder (18), a fluid tank (22), a pump (24) for moving fluid between the tank and cylinder, and a valve block (54) that controls the flow of fluid between the tank and cylinder, the pump and the value block operating to transfer fluid to or from the cylinder to raise or lower the car during operation of the hydraulic elevator system, wherein the valve block is located remotely from the tank and the pump. A system according to claim 1, wherein the tank (22) and pump (24) are disposed in the hoistway (29). A system according to claim 2, wherein the valve block (54) is disposed externally to the hoistway (29). A system according to claim 2 or 3, wherein the cylinder (18) is mounted on a support (38), and wherein the tank (22) and pump (24) are positioned underneath the said support and adjacent to the travel path of the car (14). A system according to claim 4, further including a rope (26) attached to the car (14) by a rope hitch (28), wherein the hydraulic cylinder (18) further includes a sheave (30) engaged with the rope to drive the car through the hoistway (29), and wherein the rope hitch is disposed on the car in a position such that it avoids interfering with the tank (22) and pump (24) when the car is adjacent to the tank and pump. A system according to any preceding claim, wherein the valve block (54) is located in a cabinet (50) disposed adjacent to a landing of the hoistway. A system according to claim 6, wherein the cabinet (50) further includes an electronic control system (48). A system according to any preceding claim, wherein the valve block (54) includes a release mechanism (58), wherein actuation of the release mechanism permits fluid to flow through the valve. A system according to claim 8, wherein the release mechanism (58) is manually operable. A system according to claim 1, wherein the valve block (54) and a controller (48) therefor are split into modules that are distributed in different locations.

Inventors: ADIFON LEANDRE, VARISCO CARLO, ADIFON, LEANDRE, VARISCO, CARLO
Applicants: OTIS ELEVATOR CO, OTIS ELEVATOR COMPANY
Application year: 1998
Main classification: B66B9
IPC codes: B66B9