Fluid dispenser

[0002] The present invention generally relates to automatic dispensers and more particularly relates to automatic fluid dispensers for providing a metered amount of liquid soap, or the like, on sensing the presence of a user's hand.

[0003] Many automatic fluid dispensers have been developed and have general use in restaurants, hotels, theaters, and the like. The dispensers are typically activated by light, such as infrared sensors. Heretofore developed dispensers typically are prone to clogging which renders the dispenser unusable, or leaking, the latter causing an unsafe situation.

[0004] Further, heretofore developed devices for the automatic dispensing of a measured amount of liquid are prone to falsely sensing the presence of a user and dispensing unwanted soap.

[0005] It should be easily appreciated that falsely triggered soap, or the like, when disposed on sink surfaces and floors produces slippery, unsafe surfaces which may result in injury to the public.

[0006] This problem is recognized in U.S. Pat. No. 4,967,935, which attempted to solve the problem of false operation by using an elaborate control drive circuit which included the emission of an optical signal of predetermined wavelengths in the infrared spectrum and of a predetermined configuration along with optical detection means, responsive to the wavelength and configuration of the optical signal, for actuating a timed control signal, in order to apply power to actuate a rotary motor to dispense fluid.

[0007] Such elaborate control systems still do not solve non triggering due to the presence of dark clothing or dark skin pigmentation. In addition, false triggering is known to occur by light reflected from porcelain sinks, from fluorescent light ballast or from camera flash.

[0008] The present invention provides for a fluid dispenser utilizing a disposable nozzle system wherein is self-cleaning in order to eliminate the problem of clogging. In addition, a control system to provide for actuating the dispenser which is virtually free of false triggered operation. In addition, the present invention provides for a touch free pumping action to dispense fluids which simulates manually operated fluid dispensers.

[0009] A fluid dispenser in accordance with the present invention generally includes a reservoir which provides a means for containing a fluid and tubular means, depending from the reservoir, for receiving fluid therefrom by the force of gravity, and for dispensing measured quantities of the fluid.

[0010] The tubular means generally includes an orifice and a valve seat disposed at a dispensing end of the tubular means. The reservoir means and tubular means may be disposed in a housing and may be removable as an integral unit therefrom. Accordingly, because the orifice and valve seat are replaced by a change of reservoir, possible clogging of the dispensing end of the tubular means due to prolonged use is eliminated.

[0011] A plunger is provided and slidably disposed within the tubular means for movement between a first and a second position. The plunger includes an opening therethrough for enabling fluid to flow past the plunger and a valve face is provided on the plunger for sealably engaging the valve seat when the plunger is in the first position.

[0012] A solenoid is provided and disposed in the housing adjacent the tubular means for magnetically engaging and moving the plunger from the first position to the second position upon activation of the solenoid by electrical current. The second position of the plunger is above the first position with the valve face disengaged from the valve seat. Movement of the plunger to the second position causes flow past the plunger into a tubular lower portion.

[0013] Spring means are provided and disposed within the tubular means for forcing the plunger to the first position upon deactivation of the solenoid means in order to force fluid in the tubular means lower portion through the orifice. Because the spring means is disposed in the tubular means, it is, of course, disposable therewith and, accordingly, problems of the spring fatigue or sticking due to prolonged use, are eliminated. Further, the spring provides sealing pressure between the valve face and the valve seat which prevents any fluid leakage. Thus, a positive shutoff is provided with no subsequent dripping of fluid.

[0014] Additionally, the valve face and valve seat are self-cleaning due to the mating angular surface structure provided on the valve face and valve seat. The angular surfaces provide a sliding engagement therebetween which expels any coagulated, or hardened, fluid through the orifice.

[0015] A control means is provided for sensing the presence of a user's hand beneath the orifice and providing electrical current to the solenoid means for a duration of time.

[0016] More particularly, the solenoid means has a torroidal shape and is fixed to the housing with the tubular means being removably disposed therethrough.

[0017] Preferably, the dispenser includes a first one-way valve for preventing fluid in the tubular means lower portion from flowing past the plunger as the plunger moves to the first position and enabling fluid in the tubular means upper portion to flow into the tubular means lower portion as the plunger moves to the second position.

[0018] Additionally, a second one-way valve is preferably provided for preventing fluid flow out of the tubular means upper portion as the plunger moves to the second position while enabling fluid flow into the tubular means upper portion as the plunger moves to the first position.

[0019] The control means in accordance with the present invention preferably includes a Theremin antenna for sensing the presence of a user's hand and, more particularly, the control means may include a second sensor means for sensing the presence of a user's hand and processing means for providing electrical current to the solenoid means only upon confirmation of both the Theremin antenna and the second sensor means sensing the presence of user's hand.

[0020] Preferably, the Theremin antenna is disposed at a bottom of the housing and in a spaced apart relationship with the valve seat and orifice in order to prevent any interference therebetween. An aperture is provided through the Theremin antenna for passage of fluid therethrough.

[0021] To provide greater coupling, or sensing of a user's palm, the Theremin antenna may include upstanding portions which, in combination with a relatively horizontal portion, enables the antenna to generally conform to a shape of the user's palm.

[0022] The plunger, valve seat an antenna are virtually aligned which enables vertical upward and downward movement of the user's palm, like a conventional manual pumping of a level, to cause repeated discharge of fluid from the dispenser.

[0023] The advantages and features of the present invention will be better understood by the following description when considered in conjunction with the accompanying drawings, in which:

[0024] FIG. 1 is a perspective view of the present invention;

[0025] FIG. 2 is a perspective view of the present invention as shown with a case open to show a housing, a removable reservoir, and a dispensing tube attached thereto;

[0026] FIG. 3 is a cross sectional view of the tubular dispenser shown in FIG. 2, taken along the line 3—3, generally showing a spring and a plunger disposed within the tube;

[0027] FIG. 4 is a cross sectional view similar to FIG. 3, showing movement of the plunger toward a surrounding magnetic solenoid with a first one-way valve open for enabling fluid flow into a lower portion of the tubular dispenser;

[0028] FIG. 5 is a cross sectional view similar to FIG. 4, showing the plunger beginning downward movement under the force of the spring, with the first one-way valve closed, and a second one-way valve, at a top of the tubular dispenser, open for enabling flow of fluid into the tube from the reservoir;

[0029] FIG. 6 is a perspective view of the reservoir and the dispensing tube removed from the housing;

[0030] FIG. 7 is a cross sectional view of the dispenser in accordance with the present invention more clearly showing the Theremin antenna disposed in a spaced apart relationship with the valve seat and orifice along with a second sensor for confirming presence of a user's palm, a light sensor suitable for cutting power to the control system in order to preserve electrical power may also be provided;

[0031] FIG. 8 is a perspective view of the Theremin sensor, or antenna, and a portion of the control means;

[0032] FIG. 9 is a block diagram of the control system in accordance with the present invention; and

[0033] FIG. 10 is a schematic diagram of the control system in accordance with the present invention.

[0034] With reference to FIG. 1, there is shown a fluid dispenser 10 in accordance with the present invention generally showing a case 12 which may be opened, as shown in FIG. 2, to access a housing 14 along with a reservoir 16, the reservoir providing a means for containing a supply of fluid. A tube 20 provides a means for receiving fluid flow from the reservoir 16 by the force of gravity. Preferably the tube 20 is fixed to the reservoir 16 and removable with the reservoir 16 from the housing 14. Gravitational flow of fluid into the tube 20 eliminates any need for priming the tube as well as eliminating air bubbles as is the case with many prior art devices.

[0035] The dispensing tube 20 as shown in FIGS. 3-5 includes an orifice 24 along with a valve seat 26 at a dispensing end 28 of the tube 20.

[0036] A plunger 30 is slidably disposed within the tube 20 for movement between the first position shown in FIG. 3 and a second position shown in FIG. 5. The plunger 30 includes an opening 34 therethrough for enabling fluid to flow past the plunger 30 as shown by the arrows 36 in FIG. 4 to enable fluid flow into the lower portion 42 as will be hereinafter discussed in greater detail. A valve face 44 is provided on an end 46 of the plunger 30 for sealably engaging the valve seat 26 when the plunger 30 is in the first position. This valve arrangement adjacent the orifice 24 enables the stoppage of fluid flow without any subsequent dripping of fluid through the orifice 24, i.e., the valve is self-sealing.

[0037] As hereinabove noted and shown in FIGS. 3-5, the valve face 44 and valve seat 26 have mating angular surfaces which, by the sliding engagement therebetween, also provides for self-cleaning of the device because any build-up of fluid, or coagulated fluid is forced downward and outward during operation. This structure also provides for subsequent drip free operation.

[0038] A solenoid, or actuator, 50 is disposed and fixed to the housing 14 and adjacent the tube 20 to provide a means for magnetically engaging and moving the plunger 30 from the first position, as shown in FIG. 3, to the second position, as shown in FIG. 5. An interim position of the plunger 30 is shown in FIG. 4. Operation of the dispensing tube 20 will be hereinafter discussed in greater detail.

[0039] The solenoid is activated by an electrical current to move the plunger 30 to the second position, which is above the first position, and in which the valve face 44 is disengaged from the valve seat 26. Movement to the second position causes fluid flow past the plunger 30 into the tubular means lower portion 42, as shown by the arrow 36 in FIG. 4.

[0040] Preferably, the solenoid 50 is in the shape of a torroid which enables easy removal of the tube 20 therefrom when replacing the reservoir attached thereto. Alternatively, the reservoir may be manually refilled in situ, if desired. However, reliable dispensing fluid is best achieved when the reservoir 16 and 20 are removed from the housing 16 and replaced with a full reservoir 14.

[0041] A spring 54 disposed within the tube 20 provides a means for forcing the plunger 30 from the second position to the first position upon deactivation of the solenoid 50 in order to force fluid in the tube lower portion 42 through the orifice 24. Significant advantage is afforded by placement of the spring 54 within the tube 20 because the spring then becomes disposable with the reservoir 16 and tube 20. Consequently, malfunction of the spring 54, or deterioration of its properties over time, due to use or through contact with the fluid, will not occur. Further, a conventional inexpensive metal spring may be used since long term exposure to the fluid will not occur.

[0042] An additional important function of the spring is for providing a sealing force between the valve face 44 and valve seal 26, and providing force to ensure that the sliding engagement between the valve face 44 and valve seat 26 expels clotted fluid through the orifice 24.

[0043] Control system means 60 (FIG. 9) is provided for sensing the presence of a user's palm 62 (FIG. 7) beneath the orifice 24 and providing electrical current to the solenoid 50 for a duration of time. As hereinafter discussed in greater detail, the control system may be powered by batteries 62 (FIG. 2) disposed in the housing 14 and interconnected with the solenoid 50 in a conventional manner.

[0044] With reference to FIG. 4 a first one-way valve 64 may be provided for preventing fluid in the tubular means lower portion 42 past the plunger 30 as the plunger 30 moves to the first position. The valve 64 also enables fluid flow from a tube upper portion 66 into the tube lower portion 42 as the plunger 30 moves to the second position.

[0045] As shown in FIG. 5, when the solenoid 50 is deactivated, the plunger 30 is at the second position and is forced to the first position by the spring 54. The closed valve 64 thus ensures that all of the fluid disposed in the tube lower portion 42 is dispensed through the orifice 24.

[0046] It should be appreciated that the dispensing action of the tube 20 is effective without the one-way valve 64 in view of the various openings 34, orifice 24 and tube diameters. However, the most efficient operation is enabled through the use of the one-way valve 64 and a second one-way valve 68 disposed at a top 70 shown in open position.

[0047] Closure of this valve 68, as the plunger 30 moves to the second position as shown in FIG. 4, enhances the passage of fluid from the upper portion 66 of the tube 20 to the tube lower portion 42. Flow into the tube upper portion 66 occurs through the force of gravity and, further, by the drawing action of the plunger 30 as it moves from the second position to the first position, see FIG. 5, as indicated by the arrows 72. Thus, the valve 68 enhances the dispensing efficiency of the tube 20.

[0048] As shown in FIG. 6, the reservoir may include a collapsible bag 76 for accommodating pressure differentials as the fluid passes from the reservoir 16 through the top 70 of the tube 20.

[0049] With reference now to FIG. 9, there is shown in block diagram form, the functioning elements of the control system 60 which includes a Theremin antenna 80 and an oscillator 82 which provides a signal upon sensing the presence of a user's palm 62 to a coil driver 86 which provides electrical current to the solenoid 50. A complete schematic diagram of the control system 60 is shown in FIG. 10 and further operational details are described in copending patent application Ser. No. 09/395,488. filed on even date herewith and entitled DISPENSING CONTROL SYSTEM. This referenced application is to be incorporated in its entirety for describing a control system 60 suitable for use in the present invention.

[0050] Basically, the Theremin antenna 80 and oscillator 82 is variable voltage frequency source which produces a variable control frequency as the user's palm 62 approaches the antenna 80. (FIG. 7). This is utilized by the control system 60 to provide control current to the solenoid 50.

[0051] It should be appreciated that the Theremin antenna 80 includes two separated panels 92, 94 (see FIG. 8) to establish a capacitance therebetween which is detectably altered in the proximity of the user's hand 62. No separate ground is required and accordingly the dispenser 10 may be used at any location.

[0052] As shown in FIGS. 7 and 8, the Theremin antenna 80 includes spaced apart panels 92, 94 and upstanding portions 102 which provides a means for enabling the antenna 80 to generally conform to the user's palm 62. This conformation provides enhanced coupling between the user's palm 62 and the Theremin antenna 80 and accordingly provides greater sensitivity.

[0053] The plunger 30 and antenna 80 are vertically aligned to enable pump-like movement of the user's hand, as indicated by the arrow 106, to cause the control system 60 to provide pulsed electrical current to the solenoid 50 to cause pulsed release of fluid in a manner similar to conventional manual dispenser (not shown) which utilizes an activating lever.

[0054] In addition, the duration of presence of the user's palm enables a corresponding duration of electrical current to the solenoid 50 via the control means. This causes the plunger to move to a higher second position which accordingly disposes a larger fluid quantity.

[0055] A second sensor 94 may be provided which independently detects the presence of the user's palm. In this embodiment the control system 60 provides a signal to the coil driver 86 only upon confirmation of both the Theremin antenna 80 and the second sensor 94 sensing the presence of a user's hand 62.

[0056] It should be appreciated that the second sensor 94 may be of any type, such as an infrared detection system, ultrasound system, heat detector, audio detector, or a bicolor visible light detector, among others. The independent sensing of a user's hand and confirmation by the processor ensures that accidental or false signals will not be caused which would result in unwanted dispensing of fluid, as is the case in the prior art fluid dispensers.

[0057] With the use of batteries 62, power consumption is of utmost importance and a CdS sensor 100 may be provided to turn off the control system 60 upon low ambient light. Therefore, power is conserved at night or in commercial settings with automatic interior light control. The control system 60 is activated only when a user is present, the user's presence turning on an interior light in a conventional manner.

[0058] Although there has been hereinabove described a specific fluid dispenser in accordance with the present invention for the purpose of illustrating the manner to which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the invention as defined by the appended claims.