Patent Application
20110283447
Not applicable.
Not applicable.
The present invention relates to devices for dispensing chemicals from an aerosol container in an automated manner. More particularly it provides dispensers which adjust the length of their automated dispensing cycles to correct for can pressure differentials resulting from the can being used in more and more emptied states.
Various devices have been developed where chemicals of interest (e.g. cleaning formulations; air treatment formulations) are dispensed from an aerosol container. For example, in U.S. Pat. No. 6,820,821 an automated shower enclosure cleaner dispenser was hung from a shower head. By pushing a button on the dispenser a controller caused shower cleaner to be automatically sprayed from the unit, for a set period. The cleaner could be stored in an aerosol container.
As another example, in U.S. patent application publication 2009/0236362 a dispenser was disclosed for dispensing air care product (e.g. insect repellent; fragrance) from an aerosol can, in an automated manner.
Note further that in U.S. Pat. No. 7,603,726 there was disclosed a toilet bowl cleaner dispenser. A spray nozzle was mounted over the rim of a toilet bowl, the nozzle being fed toilet bowl cleaner from an aerosol can whose spraying was triggered by a foot pedal.
A common feature of these and other analogous prior art systems is that they did not take into account pressure differences in the aerosol can that resulted as the chemical was being used. For instance, an automated ten second spray cycle when the aerosol can was completely filled could deliver more product than a ten second spray cycle when the can was three-quarters empty. This could result in too little product being delivered for some applications (when. the can was near empty) if the system was set based on expected delivery volume upon can initiation. Alternatively, if one set up the timing to insure adequate delivery when the can was near empty, chemical would be wasted when the can was newly installed.
In U.S. patent application publication 2003/0056587 a thermochromatic system was disclosed for indicating how much chemical was left in an aerosol can as it was being used. However, that information was not used to alter the length of the spray cycle as the can emptied.
Hence, a need still exists for improved automated aerosol dispensing systems.
The invention provides an aerosol dispenser control system for delivering a chemical from an aerosol container that stores the chemical to a selected location. It has a holder for the aerosol container which “recognizes” if the aerosol container has been mounted to the holder and also “recognizes” if thereafter the aerosol container has been dismounted from the holder, and an actuator for initiating dispensing of the chemical from the aerosol container.
There is also a controller for controlling dispensing of the chemical from the aerosol container in response to initiation by the actuator. The controller has a timer that determines the amount of time that the chemical is to be delivered from the aerosol container in a spray cycle of the system upon the system being actuated by the actuator. The system also has means for varying the time that the timer specifies the chemical to be dispensed from the system in a spray cycle which reflects at least in part, directly or indirectly, the extent to which the aerosol container has previously dispensed chemical via the system (e.g. how many prior spray cycles; or actual remaining volume of chemical).
In one embodiment the means for varying the time establishes a shorter dispensing time for a newly installed aerosol container as compared to the time established by the means for varying time when the aerosol container has previously dispensed chemical multiple times via the system. The controller has a memory which stores a set of instructions that define varied dispensing times per spray cycle based upon the number of spray cycles that a newly installed aerosol container has been used for, and the controller can uses those instructions to set the timer accordingly.
The selected location can be selected from the group consisting of surrounding environmental air, surfaces of a plumbing fixture, room walls and room floors. For example, the chemical can be a toilet bowl cleaner and the selected location a toilet bowl. The term “chemical” or “chemistry” means one chemical or a mixture of chemical ingredients. In one embodiment, various cleaning and/or deodorizing chemicals are suitable for use in toilet bowl cleaning using a device according to the invention. As used herein, the term “cleaning” also includes sanitizing and/or disinfecting, and the term “deodorizing” also includes freshening.
In other preferred forms the actuator is a foot pedal or a push button, the holder includes a contact switch that can be depressed by insertion of the aerosol container in the holder, and the controller will cause the timer to set a spray cycle that is less than half as long when the aerosol container is first initiated after being newly installed than when the system is initiated after the aerosol container is at least three-quarters empty.
The controller most preferably has a memory which stores a set of instructions that define varied dispensing times for various stages after an aerosol container has been installed. The system could keep track of how many dispensing cycles have occurred since the original installation of a container, compare that number of cycles to the memory, and use the comparison to set the timer accordingly.
In another preferred form the holder is associated with a contact switch that is depressed by insertion of the aerosol container in the holder (and expanded by removal of the aerosol container from the holder). Depressing the switch sends a signal to the controller that a new can has been installed. Expanding the switch sends a signal to the controller that a used can has been removed. These are used to set and reset a counter in the controller. The counter is then compared to the memory table to obtain timing settings.
It should be appreciated that for many types of aerosol propellants, as the aerosol container begins to empty, the dispensing pressure of the propellant starts to drop. This presents a problem for automated systems where dispensing is based on a fixed dispensing time cycle. This effect is pronounced for some environmentally desirable propellant gases (e.g., compressed gases such as nitrogen and carbon dioxide), due to their tendency to separate in the can from the liquid being dispensed.
The present invention, in its most preferred forms, “keeps track” of when a can is newly installed, and thereafter how many dispensing cycles have occurred since that initial installation. That information is used by the controller to increase the length of the dispensing cycle as the can empties. With a predetermined protocol for varying the spray time one can achieve essentially constant volume delivery per initiation, throughout use of almost all of the can contents.
There can be other refinements as well. For example, the controller may be provided with an anti-vandalism feature which prevents dispensing more than twice per hour. Hence, any vandal seeking to prematurely use up the aerosol would be frustrated from trying repetitive spraying by such a feature.
Further, after a given number of dispensing cycles have occurred after the installation the device could be programmed to initiate a red indicator light (or provide another signal) to notify the consumer that the aerosol can will soon need to be changed.
Power can be supplied to the dispenser via a battery associated with the holder. Alternatively, the battery can be integrated with an aerosol can refill unit, or a power cord connectible to room power could be linked to the holder/controller.
It should be appreciated that the present invention helps avoid wasting active that is dispensed from an aerosol can. It also helps minimize the incidence of activation cycles where too little active is dispensed to be fully effective, and provides a way of advising the public when the aerosol can needs to be refilled.
The foregoing and other advantages of the present invention will be apparent from the following description. In that description reference is made to the accompanying drawings which form a part thereof, and in which there is shown by way of illustration, and not limitation, preferred embodiments of the invention. Such embodiments do not necessarily represent the full scope of the invention, and reference should therefore be made to the claims herein for interpreting the scope of the invention.
As shown in
Contact of the rim 25 informs the switch 28, and thus the controller 31, of when a new can is installed. Removal of the can 22 causes the switch 28 to signal the controller that no can is present, and that a new can may soon be installed. After each spray cycle the controller increments the counter 32 by one.
When the counter 32 exceeds a preset value (e.g. 40 cycles), an indicator light 40 will be lit until the can 22 is removed from the holder 9. This advises the public that the can should be replaced.
The controller 31 may also be programmed override actuation if more than one cycle has been initiated within too short a time.
The principles of the present invention could also be applied to a device like this. In this regard, the push button 51 could replace the actuator 24 and be linked to a controller system like that of
While preferred embodiments of the present invention have been described above, it should be appreciated that the invention could be applied in a variety of other embodiments. For example, a system could be constructed to read actual pressures or liquid levels within the can, and use that information to adjust spray time. Alternatively a system could measure volume leaving the can during each spray cycle, and use that information to adjust the length of future cycles. These and other modifications may be made without departing from the spirit and scope of the invention. Thus, the claims (rather than just the preferred embodiments) should be reviewed in order to understand the full scope of the invention.
Disclosed are improved automated dispensers for dispensing aerosol can contents in a more consistent fashion.
