The present invention relates to maintenance and safety devices for hydraulic elevators, and particularly to an elevator alert that emits an audible alarm when too much hydraulic fluid from leakage collects in an elevator pit.
It is commonplace to utilize hydraulic cylinders for passenger or cargo raising and lowering within an elevator environment. The elevator car is raised and lowered by the below located hydraulic piston and cylinder assembly, which is typically located below grade or ground level in an elevator pit. Usually, with this type of elevator system, the hydraulic cylinder has a seal to retain the hydraulic fluid within it when the piston is raised and lowered. When the seal becomes faulty and leaks, unwanted amounts of hydraulic fluid escape the system. The fluid leakage is a potential environmental hazard if it flows into the environment.
Currently, the hydraulic fluid leakage is retained within a channeled annular ring just below the seal to catch the escaped fluid. The annular ring has a drainage hole to displace the collected, escaped fluid so that it does not flow over the ring. The drainage hole is connected to tubing or other conduit whose free end is typically placed in a large bucket to collect the fluid, which is gravity fed into the bucket. The bucket is simply placed on the ground of the elevator pit. Service technicians attend to the bucket from time to time to dispose of the displaced fluid in an environmentally appropriate manner.
However, this system of collecting displaced hydraulic fluid in an elevator pit has the drawback that the technician must remember to periodically check the bucket to ensure that the bucket contents do not overflow. If there is an abnormally large amount of escaping hydraulic fluid from the elevator mechanism, the bucket may overflow before the technician's scheduled maintenance check.
It would be desirable to have a signaling device to automatically warn elevator passengers and maintenance personnel when too much hydraulic fluid accumulates in the elevator pit.
Thus an elevator alert solving the aforementioned problems is desired.
The elevator alert includes an elevator pit can and a float switch disposed therein. The float switch produces an alarm-activating signal when the pit can is nearly full and overflow of oil into the pit is imminent. An alarm control unit takes a low voltage signal from one or more float switch-equipped pit cans to operate a relay that utilizes the signal to drive an alarm of various kinds and/or elevator controls. A loudspeaker is disposed on the pit can and emits an audible alarm when the float switch is closed. Optionally, a remote alarm is provided, the remote alarm being activated when the float switch is closed. The remote alarm may have a test switch for periodic maintenance, or the like. Users of the elevator, such as to passengers or building occupants, would hear the audible alarm and call maintenance to thereby prevent an oil spill.
The device may be marketed in the form of a kit to retrofit existing elevator pit cans for use with the elevator alert.
These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
As shown in
An oil line 80 feeds the cylinder 70 to supply hydraulic lift pressure to raise elevator 50 via piston 60. Oil seals are located inside an annular packing area PA, the annular packing area PA being disposed around the cylinder 70 and piston 60. It is not uncommon with this type of elevator system for the seal of packing area PA to retain the hydraulic fluid within it when the piston 60 is raised and lowered. When the seal becomes faulty and leaks, unwanted amounts of hydraulic fluid escape the system. The escaped fluid is a potential environmental hazard if it flows into the environment.
The packing area PA has a drainage outlet to displace the collected, escaped fluid so that it does not flow over the packing area PA. The drainage outlet of the packing area PA is connected to tubing 30 whose free end is connected to oil receiving spout 25 of pit can 10, which is positioned lower than the packing area PA, preferably on the pit floor.
The excess hydraulic fluid from packing area PA is gravity fed into pit can 10. The pit can 10 has a reservoir portion 15a to capture the gravity fed oil from the packing area PA. The reservoir portion 15a is capped off by a lid portion 15b. The lid portion 15b has an alarm mechanism 200 and a can breather 20. As most clearly shown in
Float switches 240 and 250 are preferably suspended at different heights within reservoir 15a. Thus, the float switches 240 and 250 are set to activate at different oil levels. Float switch 250 signals the external remote alert 300 before float switch 240 signals the alert 200 disposed on the can 10. This arrangement allows an elevator company to be alerted before persons in the immediate vicinity of elevator 50 are alerted. Either of float switches 240 or 250 can produce an alarm-activating signal when the pit can 10 is nearly full and overflow of oil into the pit is imminent.
Moreover, the pit can 10 has a water sensor A disposed on an external bottom portion of reservoir 15a, the water sensor A detecting flooding conditions on the pit floor. During maintenance operations, the pit can 10 is easily transportable because it includes a handle 6. The alarm mechanism 200 includes a loudspeaker 210 capable of 85 dB or greater audible alert output when the alarm is activated.
A 3-pole test switch 220 is disposed on the alarm mechanism 200. Electronic circuitry within alarm mechanism 200 can detect a low voltage condition and alert a user with a chirping sound if a power source, e.g., a battery, is low. The 3-pole test switch 220 can switch the device 10 into an alarm test mode, a normal mode, and a silence mode. A low voltage data type quick to connect jack 230 is disposed on the mechanism 200, the data jack 230 being used to interconnect float switch 250 via a low voltage cable 470 to remote alarm 300.
The remote alarm 300 has a power light emitting diode (LED) 310, a STATUS/OK LED 320, an alarm LED 330, data connectors 340a and 340b, test switches 350, an ac mains power cord 360, and a wire knockout 370 (for wall mount/conduit installations). The remote alarm 300, responsive to switch status of float switch 250, can signal external devices, such as elevator controllers, fire system panels, modems, or the like. CAR 1 and CAR2 signal out jacks facilitate connectivity to the aforementioned external devices. Data connection jacks 340a and 340b facilitate connectivity to at least one pit can 10.
Alarm control circuitry 400 of remote alarm 300 includes a transformer T1 (as shown in
As shown in
Preferably, the pit can 10 has approximately a 5-gallon capacity or more, and is formed from a translucent or semi-translucent material to facilitate easy visible inspection of fluid levels inside the pit can reservoir 15a.
Moreover, as shown in
During operation of the pit can alert 10, users of the elevator, such as passengers or building occupants, would hear the audible alarm and call maintenance to thereby prevent an oil spill.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US08/12721 | 11/13/2008 | WO | 00 | 1/3/2011 |
Number | Date | Country | |
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61129845 | Jul 2008 | US | |
61136738 | Sep 2008 | US | |
61136997 | Oct 2008 | US |