SMART PIT FOR HYDRAULIC ELEVATORS AND OTHER PRODUCTS USING PRESSURIZED HYDRAULIC FLUIDS

Abstract

A system controls leakage in a pit which contains equipment which uses pressurized hydraulic fluid. A tap communicates with a space holding leaked fluid, and directs leaked fluid to an fluid sump. A pump moves fluid from the fluid sump to a hydraulic fluid recapturing holding tank located outside the pit above an fluid reservoir. Fluid from the fluid reservoir is selectively relocated into an fluid reservoir which re-supplies the equipment. An electronic control panel located outside the pit interacts with a remote computer to provide a remote user with information concerning operation of the system and to allow the remote user to monitor and control at least certain operations of the system, and which processor also controls operation of the pump and actuating valve. All of the mechanical and electrical equipment of the system is located outside of the pit.

Claims

1. A system for use with a shaft with a pit which contains a hydraulic elevator or other equipment which uses pressurized hydraulic fluid and which can leak hydraulic fluid from a predetermined location within the pit, wherein said elevator or other equipment is supplied with hydraulic fluid from a reservoir which is located outside of the pit, said system comprising: a tap communicating with a space holding hydraulic fluid which has leaked from the elevator or other equipment, which tap is located inside the pit; a fluid sump for temporarily holding fluid which is located inside the pit; a communication line coupled between said tap and said fluid sump for conducting fluid from said space to said oil sump; a pump located outside of the pit; a fluid communication line between the fluid sump and the pump so that the pump is operable to pump fluid from the fluid sump to the pump; a hydraulic fluid recapturing holding tank located outside the pit; a second fluid communication line between the pump and the holding tank such that hydraulic fluid at the pump is pumped to the holding tank; a third fluid communication line between the holding tank and an inlet into the fluid reservoir; an actuating valve located in the third fluid communication line which selectively opens to allow hydraulic fluid in the holding tank to flow into the oil reservoir; and an electronic control panel located outside the pit which includes a processor programmed to interact with a remote computer to provide a remote user with information concerning operation of the system and to allow the remote user to monitor and control at least certain operations of the system, and which processor also controls operation of the pump and actuating valve; whereby all of the mechanical and electrical equipment of the system is located outside of the pit.

2. The system according to claim 1, wherein the holding tank includes a sensor for detecting the level of fluid in the tank and generates signals to the control panel corresponding to the sensed level; and wherein said control panel processor controls the actuating valve to periodically allow a portion of the fluid in the holding tank to be returned to the reservoir for recycling.

3. The system of claim 1, wherein the pit contains at least one pit sidewall, further comprising a camera for viewing the interior of the pit, which camera is located outside of the pit except for the camera lens which is directed through a sealed opening in the pit sidewall.

4. The system of claim 2, wherein the pit contains at least one pit sidewall, further comprising a camera for viewing the interior of the pit, which camera is located outside of the pit except for the camera lens which is directed through a sealed opening in the pit sidewall.

5. The system of claim 3, comprising a viewing lens covering the camera lens and being sealed relative to the pit sidewall.

6. The system of claim 2, wherein the holding tank is coupled to a sensor, located outside the pit, for detecting the level of hydraulic fluid in the holding tank, wherein the control panel receives signals from the sensor and controls the pump to maintain a predetermined level of fluid in the holding tank.

7. A system for use with a pit which has a pit floor and which contains a hydraulic elevator or other equipment which uses pressurized hydraulic fluid and which can leak hydraulic fluid from a predetermined location within the pit, wherein said elevator or other equipment is located outside of the pit and are supplied with hydraulic fluid from a fluid reservoir which is also located outside of the pit, said system comprising: a tap communicating with a space holding fluid which has leaked from the elevator or other equipment, which tap is located inside the pit; a fluid sump for holding hydraulic fluid which is located inside the pit; a fluid communication line coupled between said tap and said fluid sump for allowing fluid to leak from said space to said sump; an air line having one end in the fluid sump and extending out of the pit to a fluid sump level sensor; a water sump located below the pit floor and including a second air line having one end in the water sump and extending out of the pit to a water level sensor; and an electronic control panel which includes a processor which receives signals from the water level sensor and fluid sump level sensor and is programmed to interact with a remote computer to provide a remote user with information concerning operation of the system including communicating the levels of fluid and water in the sumps.

8. A system for use with a shaft having a pit which contains a hydraulic elevator or other equipment which uses pressurized hydraulic fluid and which can leak hydraulic fluid from a predetermined location within the pit, wherein said elevator or other equipment is supplied with hydraulic fluid from a fluid reservoir, said system comprising: a tap communicating with a space holding hydraulic fluid which has leaked from the elevator or other equipment; a fluid sump for temporarily holding leaked fluid; a fluid communication line coupled between said tap and said fluid sump for allowing fluid to leak from said space to said fluid sump; a pump; a fluid communication line between the fluid sump and the pump so that the pump is operable to pump fluid from the fluid sump to the pump; a hydraulic fluid recapturing holding tank; a second fluid communication line between the pump and the holding tank such that hydraulic fluid at the pump is pumped to the holding tank; a third fluid communication line between the holding tank and an inlet into the fluid reservoir; an actuating valve located in the third fluid communication line which selectively opens to allow hydraulic fluid in the holding tank to flow into the fluid reservoir; and an electronic control panel which includes a processor programmed to interact with a remote computer to provide a remote user with information concerning operation of the system and to allow the remote user to monitor and control at least certain operations of the system, and which processor also controls operation of the pump and actuating valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a side, sectional view of a conventional hydraulic elevator; and

[0019] FIG. 2 is a side, sectional view of an embodiment of the present invention which may be used with the elevator of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0020] FIG. 2 shows a hydraulic elevator pit 36 with a pit floor 37 and with a hydraulic cylinder 18 and piston 16 which are substantially the same as in FIG. 1 and which are contained within an elevator pit 36. The piston 16 extends vertically up out of the cylinder. The elevator shown in the FIG. 2 is a simple hydraulic elevator with a jack having a cylinder and a single piston located below the elevator car. The invention may be used, however, with other types of hydraulic elevators such as those using a jack with a cylinder and two pistons which telescope relative to one another. Also, the invention may be used with roped elevators, elevators containing multiple jacks located to the side of the car, etc. The invention may also be used in any environment that employs pressured hydraulic fluid which has a tendency potentially to leak.

[0021] Hydraulic fluid is contained in a reservoir tank 22, which is generally located outside of the pit, and selectively pumped by a pump motor 20 through a valve 52 into the cylinder 18 in order to raise the car. To lower the car, the motor remains off, and the valve 52 opens a pathway from the cylinder to the fluid reservoir tank. The weight of the car pushes fluid back into the tank.

[0022] Due to the weight of the car, hydraulic fluid in the cylinder 18 is always pressurized. To try to prevent leakage, a bushing assembly or other type of seal (together referred to as a bushing assembly 40a) is provided between the outer surface of the piston and the inner surface of the cylinder. The piston extends out of the cylinder through a cylinder cap 50 having an opening for the piston.

[0023] The cylinder cap 54 includes a hollow interior. Fluid will eventually leak through the bushing and end up inside the cylinder cap 54. In accordance with the invention a tap 56 is inserted to communicate with the hollow interior of the cap 54. A drain line 58 connects the outlet of the tap 56 with a hydraulic fluid holding tank 60, which is positioned at a height below the cylinder cap 54. Preferably, a vacuum vent check valve 62 is provided on the upper surface of the cylinder cap 54 and communicates with the interior of the cylinder cap 54 to allow air to enter to promote drainage. A second drain line 64 extends from the sump 60 to a self-priming pump 66, and a third drain line 70 extends from the pump 66 to a hydraulic recapturing holding tank 72. The holding tank 72 is preferably positioned at a height above the fluid reservoir tank 22 so that fluid in the recapturing holding tank can be returned to the fluid reservoir tank through a return line 74. An actuating valve 76 opens and closes to control the flow of fluid from the holding tank 72 back into the fluid reservoir tank 22.

[0024] As shown, piping is provided between the lower surface of the holding tank and an inlet in the upper side of the fluid reservoir tank. The actuating valve 76 prevents fluid in the holding tank 72 from flowing into the fluid reservoir tank, except when desired.

[0025] Operation of the actuating valve is controlled by an electronic control panel 42a. The control panel 42a may encompass the control features of the control panel 42 for controlling basic elevator operation, or may be a separate control panel.

[0026] The holding tank further includes a device, such as an electronic float 78, to measure the level of fluid in the holding tank. Output measurements from the float are provided as electrical signals to the control panel 42a.

[0027] A sump level sensor 80 is also coupled to the sump to monitor the level of fluid in the pump. The sump level sensor provides a signal to the electronic control panel 42a. Similarly, the level of oil in the recapturing holding tank is monitored, for example with an electronic float, and a signal is sent to the control panel 42a to be monitored.

[0028] The system preferably also includes a surveillance camera, such as an infra-red camera 84, whose lens 86 is mounted in a sealed fashion in an opening in the pit sidewall 88. The camera lens faces the interior of the pit and allows system personnel to monitor remotely conditions within the pit. The camera signal is also provided to the control panel 42a.

[0029] The control panel 42a, which if desired can be incorporated into the elevator control panel, includes a processor and memory. The processor is programmed to monitor the fluid level inside of the hydraulic sump holding tank and inside of the hydraulic recapturing holding tank. Periodically, for example when the fluid level reaches a predetermined height, the control panel either turns on the self-priming pump to move fluid from the sump 60 to the holding tank 72, or opens the actuating valve 76 to allow fluid in the holding tank to flow back into the fluid reservoir tank 22.

[0030] The control panel 42a also includes electronic communication equipment for communicating with one or more remote computers. The method of communication can include any known method such as internet, satellite or land line telephone, cell, short text messaging, and so on. The processor operates the equipment in a predetermined manner, which includes sending alert signals to predetermined destinations in the event of a spill, a potential spill, or equipment failure. The processor is also programmed to accept predetermined commands from remote locations or from a computer located outside of the control panel, and thus can communicate with a computer operated by service personnel who are physically present as well as personnel who are located remotely. Such commands include operating the camera for remote viewing and monitoring. Preferably, the processor includes programming for encryption and security to allow access only to authorized personnel.

[0031] In the system described above, all of the mechanical and electrical equipment, i.e., the electronic control panel 42a, the fluid return pump 66, the fluid reserve tank 22, valves 52, 72, and pump motor 20 are located outside of the elevator pit. While the lens 86 of the monitoring camera needs to have access to the pit, it is sealed in the wall 81 of the pit, and thus isolated from the pit itself. Also, a protective lens may be provided on top of the camera lens and sealed to the pit wall for further isolation of the camera from the interior of the pit.

[0032] The foregoing represent preferred embodiments of the invention. Various modifications will be evident to persons skilled in the art, and are intended to be within the scope of the invention, as set forth in the following claims.