Electricity: electrothermally or thermally actuated switches – Thermally actuated switches – Expansible or vaporizable fluid actuated
Reexamination Certificate
2001-03-02
2003-09-09
Gandhi, Jayprakash N. (Department: 2125)
Electricity: electrothermally or thermally actuated switches
Thermally actuated switches
Expansible or vaporizable fluid actuated
C251S089000, C070S174000, C074S527000, C337S002000
Reexamination Certificate
active
06617954
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is generally directed to a safety device and more particularly pertains to a device for preventing the inadvertent adjustment of a water heater's set temperature.
The temperature at which water is maintained within a water heater is typically adjusted by a rotatable dial. In the case of a gas-fired water heater, such dial is associated with a controller valve that directs the flow of gas to a burner whenever the actual water temperature falls below the set temperature. Excessive water temperature is a hazard in that it may cause scalding at any of the various faucets or appliances serviced by the water heater. Accidental or inadvertent adjustment of such dial can cause water to issue at unexpectedly high temperatures. On the other hand, while a temperature setting that had inadvertently been dialed down may not be hazardous, it can nonetheless constitute a nuisance.
The temperature set dial on gas controller valves is typically easily accessible and easily rotated. If the water heater is located in a readily accessible location, such as in an unsegregated section of a garage or an unlocked closet, the dial can easily be tampered with by children playing in the area or by individuals bent on mischief.
Properly securing a water heater from this type of tampering typically results in additional cost and/or inconvenience as to its use. Locking the water heater into an enclosure requires either keys to be kept or a combination to be remembered. An enclosure may also hamper the installation, replacement or servicing of the water heater.
Devices have previously been developed that are associated directly with a control knob or valve to prevent tampering but again, substantial additional cost of manufacture or inconvenience as to use is typically involved. Such devices either lock the knob or valve into place to physically prevent it from being rotated or serve to decouple the knob or valve from an internal actuation mechanism. In addition to the extra cost involved in the manufacture, such devices are often difficult to retrofit to existing installations.
A device is therefore needed with which the inadvertent adjustment of a temperature control dial can be prevented or deterred, that can be manufactured and installed with minimal cost, that can be readily retrofitted to existing controllers and that is easy for an adult to manipulate.
SUMMARY OF THE INVENTION
The present invention provides a simple device that prevents inadvertent adjustment of a water heater's set temperature. Although the device prevents tampering by small children, it is easily defeated by an adult user. The device additionally makes it difficult for anyone to tamper with the controller's temperature calibration. Moreover, the device is inexpensive and is easily retrofitted to existing controller devices.
The device includes a spring-loaded prong that is attached to the controller housing so as to extend across the face of the temperature set dial. The prong is configured to apply a force against the face of the dial and to engage outwardly extending nubs formed thereon. The interaction of the prong with a nub positively prevents rotation of the dial. In order to make an adjustment to the temperature setting, the prong must be pulled or pried off of the face of the dial to disengage the nub, wherein the force necessary to do so exceeds the capability of most small children. An adult on the other hand would be capable of exerting enough force, thereby releasing the dial for rotation to the desired setting. An aperture formed in the prong allows an appropriate prying tool to optionally be inserted to allow the force of the prong to be more easily defeated. The position of the prong additionally serves to prevent the dial from being pulled off of its shaft to thereby preclude access to the temperature calibration screw located below the dial.
The prong is easily retrofitted to an existing controller by removal of a single fastener, insertion of the base of the prong and replacement of the fastener. Optionally, the prong may be configured to be clipped onto the controller housing. A dial devoid of outwardly extending nubs formed on its face would additionally have to be replaced which simply requires the original dial to be pulled of its shaft and the replacement to be slipped there onto.
These and other features and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment which, taken in conjunction with the accompanying drawings, illustrates by way of example the principles of the invention.
REFERENCES:
patent: 1068961 (1913-07-01), Baker
patent: 1104918 (1914-07-01), Mouat
patent: 1473774 (1923-11-01), Leech, Jr.
patent: 1651038 (1927-11-01), Muller
patent: 1673454 (1928-06-01), Hochstein
patent: 1689236 (1928-10-01), Fraser, Jr.
patent: 2253162 (1941-08-01), Ayers
patent: 2953937 (1960-09-01), Jackson et al.
patent: 3203265 (1965-08-01), Flegel
patent: 3537473 (1970-11-01), DeZurik, Jr.
patent: 3597138 (1971-08-01), Ray
patent: 3810064 (1974-05-01), Flegel
patent: 4235323 (1980-11-01), Dykzeul
patent: 4588851 (1986-05-01), Turner
patent: 4895043 (1990-01-01), Lee
patent: 5003803 (1991-04-01), Richards
patent: 5363720 (1994-11-01), Sanchez
patent: 5427135 (1995-06-01), Kieper
patent: 5427140 (1995-06-01), Bosanquet
patent: 5513831 (1996-05-01), Seward
patent: 5590682 (1997-01-01), Fischer
patent: 5647389 (1997-07-01), Holloway
patent: 5950982 (1999-09-01), Williams
patent: 6012445 (2000-01-01), Santelli, Jr.
Blackwell Sanders Peper Martin LLP
Gandhi Jayprakash N.
Robertshaw Controls Company
LandOfFree
Tamper resistant temperature controller for a gas-fired... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tamper resistant temperature controller for a gas-fired..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tamper resistant temperature controller for a gas-fired... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3066509