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 a fluid sump. A pump moves fluid from the fluid sump to a hydraulic fluid recapturing holding tank located outside the pit above a fluid reservoir. Fluid from the fluid reservoir is selectively relocated into the 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 fluid 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 and 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 fluid 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 fluid 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.

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.

3. 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.

4. The system according to claim 2, wherein the sensor is an electronic float.

5. The system according to claim 2, 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.

6. 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.

7. The system of claim 6, comprising a viewing lens covering the camera lens and being sealed relative to the pit sidewall.

8. The system of claim 1, further comprising a sump level sensor coupled to the fluid sump, the sump level sensor being configured to detect a level of hydraulic fluid in the fluid sump.

9. The system according to claim 8, wherein said control panel processor controls the pump to periodically allow fluid in the fluid sump to be pumped to the holding tank based on a predetermined electronic signal from the sump level sensor.

10. The system of claim 1, wherein the holding tank is positioned higher than the fluid reservoir.

11. The system of claim 1, wherein the fluid sump is positioned lower than the pump.

12. 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.

13. 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 fluid 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 hydraulic fluid and which is located inside the pit; a first fluid communication line coupled between said tap and said fluid sump for conducting fluid from said space to said fluid sump; a second fluid communication line coupled between the fluid sump and the fluid reservoir; a pump located outside of the pit and operable to selectively pump fluid from the fluid sump to the fluid reservoir over the second fluid communication line; an actuating valve located along the second fluid communication line which selectively opens to allow hydraulic fluid from the fluid sump to flow into the fluid 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.

14. The system of claim 13, wherein the second fluid communication line includes a hydraulic fluid recapturing holding tank located outside the pit and coupled between the fluid sump and the actuating valve, said holding tank being configured to store the hydraulic fluid from the fluid sump, and wherein the actuating valve selectively opens to allow the hydraulic fluid in the holding tank to flow into the fluid reservoir.

15. The system of claim 14, wherein the holding tank is positioned higher than the fluid reservoir.

16. The system of claim 13, wherein the fluid sump is positioned lower than the pump.

17. 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

(1) FIG. 1 is a side, sectional view of a conventional hydraulic elevator; and

(2) 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

(3) 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.

(4) Hydraulic fluid is contained in a reservoir tank 22, which is generally located outside of the pit 36, and selectively pumped by a pump motor 20 through a valve 52 into the cylinder 18 in order to raise the car 10. To lower the car, the motor 20 remains off, and the valve 52 opens a pathway from the cylinder 18 to the fluid reservoir tank 22. The weight of the car 10 pushes fluid back into the tank 22.

(5) Due to the weight of the car 10, 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 16 and the inner surface of the cylinder 18. The piston 16 extends out of the cylinder 18 through a cylinder cap 54 having an opening for the piston 16.

(6) 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 (i.e., sump) 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 72 can be returned to the fluid reservoir tank 22 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.

(7) As shown, piping is provided between the lower surface of the holding tank 72 and an inlet in the upper side of the fluid reservoir tank 22. The actuating valve 76 prevents fluid in the holding tank 72 from flowing into the fluid reservoir tank 22, except when desired.

(8) 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.

(9) The holding tank 72 further includes a device, such as an electronic float 78, to measure the level of fluid in the holding tank 72. Output measurements from the float 78 are provided as electrical signals to the control panel 42a.

(10) A sump level sensor 80 is also coupled to the sump 60 to monitor the level of fluid in the sump. The sump level sensor 80 provides a signal to the electronic control panel 42a. Similarly, the level of oil in the recapturing holding tank 72 is monitored, for example with an electronic float 78, and a signal is sent to the control panel 42a to be monitored.

(11) The system preferably also includes a surveillance camera 84, such as an infra-red camera, whose lens 86 is mounted in a sealed fashion in an opening in the pit sidewall 81. The camera lens 86 faces the interior of the pit 36 and allows system personnel to remotely monitor conditions within the pit 36. The camera signal is also provided to the control panel 42a.

(12) The control panel 42a, which can optionally be incorporated into the elevator control panel, includes a processor and memory (not shown). The processor is programmed to monitor the fluid level inside of the hydraulic sump holding tank 60 and inside of the hydraulic recapturing holding tank 72. Periodically, for example, when the fluid level reaches a predetermined height, the control panel 42a either turns on the self-priming pump 20 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 72 to flow back into the fluid reservoir tank 22.

(13) 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.

(14) 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, 76, and pump motor 20 are located outside of the elevator pit 36. While the lens 86 of the monitoring camera needs to have access to the pit 36, it is sealed in the sidewall 81 of the pit, and thus isolated from the pit itself. Also, a protective lens may be provided on top of the camera lens 86 and sealed to the pit wall 81 for further isolation of the camera 84 from the interior of the pit 36.

(15) 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.