Patent Application
20170148593
This disclosure relates to a float switch assembly for detecting fluid levels in a reservoir. This disclosure more particularly relates to a float switch assembly for detecting fluid levels in a Christmas tree stand.
A float switch is a device used to detect the level of liquid within a reservoir, container, or the like. Numerous types of float switches are known. They may be physically integrated with the devices they control, or physically independent and only electrically integrated with those devices.
Float switches are often used as safety devices. For instance, many times the water in a Christmas tree stand drops to low levels due to healthy propagation efforts by the tree. Since the tree has been cut of its roots, the tree can only live a short time after it is harvested. It is important to keep the water filled in the tree stand so that the tree branches and needles do not dry out, thereby preventing the tree from becoming a fire hazard.
In the past, a variety of methods have been proposed for adjustably positioning the float switch at a preselected position in order to maintain liquid levels within certain desired bounds. Typically, a portion of the float switch is secured at a certain vertical position of the reservoir with the use of hardware and requires a multiplicity of components and other tools for adjusting the switches. Unfortunately, such practices do not lend themselves to easy, quick installation and are generally unsatisfactory in one respect or another.
Therefore, it can be appreciated that there exists a continuing need for a new and improved float switch assembly that alerts someone when the fluid level in a fluid reservoir falls below a predetermined point.
According to certain embodiments, the float switch assembly comprises (i) a frame, (ii) a movable housing engaged with the frame, and (iii) a float switch engaged with the movable housing.
Also disclosed is a float switch assembly comprising (i) a frame, (ii) a movable housing engaged with the frame, (iii) a float switch engaged with the movable housing, (iv) an electrical circuit in electrical communication with the float switch, (v) a signal generator in electrical connection with the electrical circuit, and (v) a power source.
Also disclosed is a combination comprising (a) a Christmas tree stand, (b) a float switch assembly comprising a (i) a frame, (ii) a movable housing engaged with the frame, (iii) a float switch engaged with the movable housing, (iv) an electrical circuit in electrical communication with the float switch, (v) a signal generator in electrical connection with the electrical circuit, and (v) a power source.
The electrical circuit and the signal generator are contained or otherwise housed within a control box. When the fluid level in a reservoir, such as a Christmas tree stand, drops below a predetermined point, the float switch closes the electrical circuit inside the control box. Closing the electrical circuit activates the signal generator to produce a visual signal, an audible signal, or both a visual and audible signal to alert someone that the fluid level in the reservoir is too low and needs to be refilled. Once the fluid level in the reservoir is restored to the predetermined level, the float switch opens the electrical circuit and the signal generator is deactivated. Consequently, the visual and/or audible signal turns off.
The float switch assembly includes a frame. The frame defines a region where the float switch is positioned. The frame comprises (i) a collar that is located at or near its upper end, (ii) a base member that is located at or near its lower end, and (iii) at least two support arms connecting the collar to the base member. The geometric shape of the collar and base member of the frame are not limited. According to certain embodiments, the perimeter of the base member of the frame is greater than the perimeter of the collar. According to certain embodiments, the collar and the base member of the frame are substantially circular. According to the embodiments where the collar and base member of the frame are substantially circular, the outer circumference of the base member is greater than the outer circumference of the collar.
At least one of the support arms of the frame may include a scale comprising a plurality of gradations and sub-gradations, otherwise referred to as measuring lines, for accurately positioning the float switch to the desired position.
The components of the float switch assembly can be die-cast, sand-cast, injection molded in plastic, extruded, or fabricated by conventional welding techniques.
The components of the float switch assembly may be manufactured from polymers, metals, metal alloys, or composite materials. According to certain illustrative embodiments, the components of the float switch are manufactured from polymer materials.
In some embodiments, the base member of the frame is substantially flat. The base member is adapted to rest on the inner surface of the bottom wall of a fluid-containing reservoir, container, or the like. In some embodiments, the base member has at least one aperture that stabilizes the float switch assembly and prevents it from tipping over or from lifting up and off the bottom wall of the reservoir. In some embodiments, the base member is a circular base member having a substantially central aperture.
The movable housing of the float switch assembly may comprise an elongated hollow conduit having opposite first and second ends. The float switch is connected to the second end of the elongated hollow conduit. The elongated hollow conduit is engaged with the collar of the frame and is movable in the direction of the longitudinal axis of the elongated hollow conduit. According to certain embodiments, the elongated hollow conduit is in a friction fit engagement with the collar so that the elongated hollow conduit and the float switch can be maintained at the desired position during normal operation of the device. In other embodiments, the collar incorporates a tightening screw for further securing the elongated hollow conduit at the desired position.
The float switch and electrical wiring electrically connecting the float switch to the electric circuit in the control box are isolated from the liquid whose level is being sensed. This can be achieved by housing a fluid-proof plastic float sealed at both ends and a fluid-proof power cord emanating from one end, for electrical interconnection between the float switch and the electric circuit.
The density of the float switch is less than fluid, so that it will float at the surface of a body of fluid. The float is free to move up and down in response to changes in fluids levels in the reservoir.
In some embodiments, the float switch comprises at least one reed switch to sense changes in fluid levels and to close the electrical circuit to activate the signal generator. Reed switches are magnetically-operated switches, which are formed by a pair of spaced contacts. The contacts are connected to electrical leads, each lead is connected to at least one control box that houses an electric circuit. A suitable reed switch is commercially available from Omega, under the designation LV-80.
In certain embodiments, the reed switch is contained horizontally within a body portion of the switch and is surrounded by the float. The magnet is disposed to operate in a vertical plane relative to the reed switch and when the level drops to a certain level, the float similarly drops causing the magnet to activate the reed switch, which then activates the electric circuit that is in electrical communication with the reed switch.
In some embodiments, the float switch is attached to the second end of the elongated hollow conduit by tapping threads into the second end of the elongated hollow conduit. In other embodiments, the threads are molded in place on the interior surface of the second end of the elongated hollow conduit. In other embodiments, the float switch is bonded to the second end of the elongated hollow conduit with an adhesive.
In some embodiments, the float switch and movable housing (e.g., the elongated hollow conduit) components are integrally connected. For example, the housing component is integrally molded to the float switch. Alternatively, the float switch and housing components may be separate components that can be disconnected from each other.
The float switch assembly is capable of having differential adjustment means. Switch differential is the difference in fluid level between the point where the float switch is actuated versus the point at which the switch is not actuated. The elongated hollow conduit is movable in the direction of the longitudinal axis of the elongated hollow conduit. The on-off differential of the float switch is adjusted by moving the elongated hollow conduit to the desired position.
The float switch is electrically connected to the electric circuit by an elongated electrical connection, such as an electrically conductive wire or power cord. The electric circuit is housed within a control box. The control box includes an elongated electrical wire terminating in a plug. The plug is adapted to be inserted into an electrical outlet, such as a wall outlet, to provide a source of electrical power to the control box.
The control box may incorporate a 110-120 VAC outlet which permits lighting devices, such as a string of Christmas lights, to be plugged into the control box. The plug and electrical wire extend from the control box to connect to a power source, such as a source of direct current from a wall outlet. Alternatively, the power source for the control box may include a battery.
The electronic circuitry housed in the control box controls the activation of the signal generator to generate a visually perceptible signal and/or an audibly perceptible sound signal in response to a drop in fluid level in the reservoir being monitored.
In some embodiments, the control box includes a programmable sound making device comprising a memory that stores a plurality of audible segments and a speaker. The user of the device may record a personalized audible signal, message or alarm. The recorded signal, message, or alarm is stored in the memory of the device. When the fluid level in the reservoir being monitored drops below the predetermined level, the float switch closes the electric circuit and the signal generator generates the recorded signal, message, or alarm to alert someone that the fluid level must be refilled.
As will be readily understood by those skilled in the art, the float switch assembly provides a means for securely and rapidly positioning the operative position of the float switch so that the precise level of fluids within a reservoir, container, or the like can be adjusted with greater ease and without the use of separate components.
For the purposes of this description, the float switch assembly will be described in terms of its application to a Christmas tree stand, but it is to be understood that this is merely by way of example and in no way limits the float switch to such an application.
The float switch assembly can detect the fluid level in a Christmas tree stand at two stages, a full stage and an empty stage. At the full stage, the float switch is in the off position. At the empty stage, for example due to the tree absorbing fluid, the float drops causing the magnet to activate the reed switch, causing the electric circuit to activate the signal generator, housed within the control box, to emit at least one visual and/or audible signal. For example, the activated circuit may flash a string of Christmas lights that are plugged into the outlet on the control box.
When the float switch closes the electrical circuit, the circuit housed in the control box activates the visually and/or audibly perceptible signal. The visual and/or audible signal continues until the fluid level is restored to the predetermined full position and deactivates the signals.
In some embodiments, when the fluid level drops below a predetermined point, the float switch triggers a first relay in the electric circuit. Triggering the first relay activates a flasher unit. The activation of the flasher unit then triggers a second relay, resulting in the periodic opening and closing of the flasher outlet on the control box. This causes the lighting device plugged into the control box to turn off and on until the fluid level is restored to the predetermined full position.
In some embodiments, when the fluid level drops below a predetermined point, the float switch triggers a first relay in the electric circuit. Triggering the first relay activates a timing circuit contained in the electric circuit. The activation of the timing circuit triggers a third relay to periodically open and close at a set interval, which triggers a voice recorder to periodically turn on and off to play a recorded message.
In some embodiments, when the fluid level drops below a predetermined point, the float switch triggers a first relay in the electric circuit. Triggering the first relay activates the flasher unit and the timing circuit contained in the control box. The activation of the flasher unit then triggers a second relay to periodically open and close, resulting in the periodic opening and closing of the flasher outlet. The activated timing circuit triggers the third relay to periodically open and close at a set interval, which triggers the voice recorder to periodically turn on and off to play a recorded message.
The float switch assembly can be easily adjusted for use in a wide range of fluid reservoirs instead of having to change the design, structure and/or installation of the switch assembly for each different reservoir design.
The float switch assembly has means for adjusting the switch differential essentially externally of the float switch assembly and without necessitating disassembly of the float switch assembly. The float switch assembly need not be fixedly attached to the reservoir, as its design permits the assembly to be in a stable, upright free-standing position on the bottom of the reservoir.
The float switch assembly has a long and slender structure which allows the float switch assembly to be utilized in a wide range of fluid reservoirs, particularly reservoirs having narrow openings, such as Christmas tree stands.
The float switch assembly is readily understood when read in conjunction with illustrative
While the float switch assembly, and methods of using the float switch assembly have been described in connection with various embodiments, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiments for performing the same function. Furthermore, the various illustrative embodiments may be combined to produce the desired results. Therefore, the float switch assembly, and methods of using the float switch assembly should not be limited to any single embodiment.
It will be understood that the embodiments described herein are merely exemplary, and that one skilled in the art may make variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as described hereinabove. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the invention may be combined to provide the desired result.
