Abstract:
A dispenser ( 20 ) for attachment to a container ( 22 ) containing a fluid material, including an actuator ( 110 ) which keeps the container ( 22 ) in a substantially constantly open configuration so as to allow the fluid to pass into the dispenser ( 20 ), and a controllable outlet ( 36 ), through which a portion of the fluid is emitted from the dispenser ( 20 ), substantially independent of the fluid pressure in the container ( 22 ).

Description:
This is a division of application Ser. No. 09/582,295, filed Oct. 10, 2000, which was a national phase of International Application PCT/IL98/00618, filed Dec. 18, 1998 which designated the U.S. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to the field of spray dispensers, and specifically to electric-powered automatic dispensers. 
     BACKGROUND OF THE INVENTION 
     Certain products such as insecticides and air fresheners are commonly supplied in pressurized containers. The contents of the container are usually dispensed to the atmosphere by pressing down on a valve at the top of the container. The contents of the container are consequently emitted through a channel in the valve. 
     In many cases it is desired that the contents of the container be automatically dispensed periodically. Many automatic dispensers are known in the art. 
     A first type of automatic dispenser includes dispensers with mechanical means, such as an arm, which periodically presses the valve of the container. Such dispensers are described, for example, in U.S. Pat. Nos. 4,184,612, 3,739,944, 3,543,122, 3,768,732, 5,038,972 and 3,018,056. However, these dispensers cannot accurately control the output of the container, since the valve and the contact of the dispenser with the valve are not accurately controlled by the dispenser. Also these dispensers are generally not portable and are fit for use only with containers of a specific size. The valves are also susceptible to failure because of valve sticking, resulting in complete discharge of the contents of the container within a short period. 
     Another type of automatic dispenser employs a solenoid, which is periodically energized in order to emit a burst of the contents of the container. Such dispensers are described, for example, in U.S. Pat. Nos. 4,415,797, 3,351,240 and 3,187,949. These dispensers require substantial electrical power, and are dependent on gravity and/or the fluid pressure in the container for successful operation. 
     A third type of automatic dispenser is described, for example, in U.S. Pat. No. 5,447,273. In this automatic dispenser the pneumatic pressure of the container is used to operate a timing device causing the contents of the container to be periodically dispensed. However, the ability to control the dispensation intervals is complicated and limited due to the pneumatic characteristic of the timing device. 
     Automatic dispensation from non-pressurized containers is described, for example, in U.S. Pat. No. 5,449,117. 
     SUMMARY OF THE INVENTION 
     It is an object of some aspects of the present invention to provide an automatic spray dispenser, which allows accurate control of the amount of discharged material. Therefore, it is possible to use the dispenser with materials which require dispensing in accurate quantities. 
     It is a further object of some aspects of the present invention to provide an automatic spray dispenser which allows flexibility in setting the frequency of dispensation. 
     It is yet another object of some aspects of the present invention to provide an automatic spray dispenser which is compatible with a large variety of containers. 
     It is yet another object of some aspects of the present invention to provide an automatic spray dispenser which is compact and portable. 
     It is yet another object of some aspects of the present invention to provide an automatic spray dispenser whir is operationally reliable. 
     It is vet another object of some aspects of the present invention to provide an automatic spray dispenser which is of a simple construction. 
     It is yet another object of some aspects of the present invention to provide an automatic spray dispenser which has low energy consumption. 
     In accordance with preferred embodiments of the present invention, there is provided a spray dispenser which can be mounted on a large variety of pressurized containers, for dispensing aerosol materials and other fluids. Such containers typically have a built-in valve, which is actuated by being pressed down. The spray dispenser is firmly attached to the container, whereupon the valve of the container is kept constantly open by an actuator. 
     Preferably, the valve is continuously depressed by a corresponding plunger in the dispenser. Preferably, the plunger is an integral part of the dispenser. Alternatively or additionally, the plunger is a separate unit which accommodates the dispenser to the container. Thus, the valve is held constantly open, but the dispenser prevents the contents of the container from being released. This feature enables the dispenser to operate substantially independently of any particular characteristics of the container, and it is possible to employ the dispenser of the present invention with a large variety of standard and non-standard containers. The dispenser includes an outlet which controllably releases portions of the contents of the container according to predefined or user actuated instructions. 
     Preferably, the dispenser allows automatic periodic dispensing of the spray. The amount of spray emitted at each period is preferably controlled by setting the time in which the outlet is open. 
     In some preferred embodiments of the present invention, the dispenser comprises an electric circuit, preferably including a microprocessor, which controls the release of material from the container, according to predetermined settings, preferably set by a user. Preferably, the settings include the interval between dispensations and the duration of each dispensation. Alternatively or additionally, he dispenser includes an operation switch for selecting among constant/periodic/off modes of operation. Further preferably, the dispenser can be programmed to have different frequencies of operation at different times. For example, an insecticide may be dispensed in an office during nights before work days at a first rate, while during nights before holidays the insecticide is dispensed at a second rate. 
     In some preferred embodiments of the present invention, a photoelectric cell is coupled to the microprocessor, to change the operation mode of the dispenser between day and night modes of operation. The microprocessor may be further coupled to a thermostat, wind sensor or any other required sensors, such as sensors of “MEMS” (Micro-Electro-Mechanical-Systems) technology, so as to operate the dispenser in response thereto. In one such preferred embodiment, the dispenser has a plug for connecting to external sensors and/or remote controls. 
     In some preferred embodiments of the present invention, the dispenser actively opens and closes the controlled outlet, so that its operation is not dependent on gravity or on the pressure within the container. Thus the dispenser may be positioned in any orientation without causing problems in its operation. 
     In some preferred embodiments of the present invention, the dispenser has an open state in which a fluid is emitted from the dispenser, and a closed state in which the fluid is prevented from leaving the dispenser. The dispenser substantially does not consume energy during the open and closed states, and consumes energy only during transition between the open and closed states. 
     In preferred embodiments of the present invention, the dispenser comprises a motor, which applies rotational movement in order to dispense material from the dispenser. The use of rotational, rather than linear, movement generally requires less energy and allows better control of the dispenser. The use of a motor requires energy only when opening and closing the outlet, whereas a solenoid continuously requires energy in order to dispense the material in the container. 
     Preferably, the dispenser is assembled in a simple manner without use of screws, in order to reduce the cost and skill required for assembly. Further preferably, the dispenser does not include gears or cams, so that accurate rate sizing and placement is not required in the manufacturing process. 
     Preferably, the spray dispenser is battery-operated and contains within it batteries which supply operation power. Preferably, the batteries are packed in an easily replaceable battery power pack. Most preferably, the batteries are rechargeable, and may be recharged within the dispenser, while the dispenser is in use, for example, using a car battery, an AC electric supply, a solar power cell or any other suitable power source. Alternatively or additionally, the dispenser may operate directly on power received from a car battery or from an AC electric supply and, preferably, contains a transformer suitable for connecting to a local electric line. In addition to the battery or AC power, or as an alternative thereto, the dispenser may receive power from a solar cell, so that it may be placed in remote areas, without any wired connection and without the necessity of replacing its power supply. In some preferred embodiments of the present invention, the microprocessor has a separate power supply from the power supply of the motor, so that short failures in the main power supply do not erase the time settings of the microprocessor. The power supply of the microprocessor is preferably a miniature battery, such as used for example in electric watches. 
     In same preferred embodiments of the present invention, the outlet of the dispenser comprises an orifice which allows attachment of a large variety of different orifice heads thereto. Such orifice heads may include nozzles of various dispersion properties, for example, wide-range heads for covering large angles at a close range, long-range orifice heads, and curved orifice heads which preferably turn in response to emission of the spray, to cover a wider area. Other orifice heads may also be used, including moisture heads, illumination heads, whistle heads and flame heads. The orifice heads may have various orifice sizes, including small diameters which may achieve a directional force sufficient to mechanically move an object, such as a switch. 
     Dispensers in accordance with the present invention may be used in conjunction with containers of a wide variety of materials, including, but not limited to, sterilizers, insecticides, deodorants, smoke absorbents, colored smoke, oil, clue (for example, for use on factory production lines), fuels (which are periodically sprayed into a furnace or engine, for example), gases (including air), paints, fire extinguishers, cleaning materials and water. Whereas prior art dispensers are unsuitable or unsafe to use with certain materials that are considered harmful at large concentrations, such as insecticides, the dispenser of the present invention allows very small quantities of such materials to be dispensed at a high accuracy. This accuracy is achieved partially due to the feature that as the dispenser holds the valve of the container constantly open, the emission of the contents of the container is controlled solely by the dispenser. In addition, the rotational movements of the motor cause the speed at which the dispenser is opened and closed to be fast and precisely defined. Therefore, dispensers in accordance with preferred embodiments of the present invention can be used to dispense insecticides and other materials in rooms occupied by humans, animals or delicate plants, with fewer restrictions than may be required by prior art dispensers. 
     In preferred embodiments of the present invention, adapters are provided for connecting the dispenser to containers of various sizes, shapes, structures and positions and to containers having valves of various sizes. Preferably, such adapters fit between the valve and the dispenser, forming an airtight connection therebetween. Furthermore, adapters may also be provided for connecting the dispenser to containers which do not have valves of their own. 
     In some preferred embodiments of the present invention, a hose adapter is used to connect between the container and the dispenser. At one end the hose adapter has a connector which fits the container. The connector may either include a plunger, as described above, which fits on standard valves or any other suitable fitting. On its other end, the adapter has a valve or other fitting for connecting to the dispenser. Use of such a hose adapter allows placement of the dispenser at a high or otherwise inaccessible location, while dispensing material from a large container positioned on a lower surface. Furthermore, the hose adapter may be connected to a multiplicity of containers and/or to a multiplicity of dispensers. 
     It is noted that the fluid in the containers of preferred embodiments of the present invention may be pre-pressurized or may be pressurized each time it is desired to extract the fluid. For example, the motor of the dispenser may be used to pressurize the contents of the container each time it extracts fluid from the dispenser. Dispensers in accordance with other preferred embodiments of the present invention may also be utilized to periodically emit accurate amounts of material from non-pressurized containers. For example, such a dispenser may be used to water plants with a water container placed with its orifice facing down. A fertilizer or other nutrient may be mixed with the water, as is known in the art. Alternatively, an air pressure supply or a container of pressurized air or other gas may be used along with a Venturi jet to emit the contents of one or more non-pressurized containers. 
     Although in the above embodiments the dispenser is described as forming a unit separate from the container, it will be appreciated by those skilled in the art that the dispenser may be designed to fit a specific container or may be formed as part of a container. 
     There is therefore provided in accordance with a preferred embodiment of the present invention, a dispenser for attachment to a container containing a fluid material, including: 
     an actuator which keeps the container in a substantially constantly open configuration so as to allow the fluid to pass into the dispenser; and 
     a controllable outlet, through which a portion of the fluid is emitted from the dispenser, substantially independent of the fluid pressure in the container. Preferably, the fluid material in the container is pressurized or non-pressurized. 
     Preferably, the size of the emitted portion is controlled by varying an amount of time in which the controllable outlet is in an open state. 
     Preferably, the dispenser has an open state in which the fluid is emitted from the dispenser, and a closed state in which the fluid is Prevented from leaving the dispenser, and the dispenser consumes energy substantially only during transition between the open and closed states. 
     Preferably, the dispenser includes an electric motor which controls passage of the portion of the fluid through the outlet. 
     There is further provided in accordance with a preferred embodiment of the present invention, a dispenser for attachment to a container containing a fluid material, including: 
     an actuator, which keeps the container substantially constantly in an open configuration so as to allow the fluid to pass into the dispenser; and 
     an electric motor, which opens the dispenser so that fluid is emitted therefrom and closes the dispenser to prevent the fluid emission. 
     Preferably, the motor is battery operated and/or is connected to an electric line. 
     Further preferably, the motor opens and closes the dispenser by a rotational movement. 
     Preferably, the container has a valve, and the dispenser has a bore therethrough, which receives the fluid from the valve, the bore including a first part having a first inner diameter and a second part having a second inner diameter, larger than the first inner diameter, wherein the dispenser includes: 
     a hollow shaft, axially movable within the bore, the shaft having a hole disposed along the length thereof such that when the hole is positioned in the first part of the bore, the fluid does not pass through the shaft, and when the hole is in the second part of the bore, the fluid passes through the shaft and is emitted from the dispenser. 
     Preferably, the dispenser includes a lever connected to the shaft, such that the shaft is axially moved by the lever. 
     Further preferably, the dispenser includes a screw which drives the lever, and the lever includes an internal thread for receiving the screw. 
     Preferably, the outlet includes an orifice through which the material is emitted, and the size of the orifice is not substantially smaller than the size of the hole, so that a gas leaving the container does not expand within the dispenser. 
     Preferably, the dispenser operates substantially without dependence on gears or cams. Preferably, the container has a valve and the actuator includes a plunger which depresses the valve. Alternatively or additionally, the actuator includes a hose. Preferably, the dispenser includes a processor which periodically actuates emission of the fluid. Further preferably, the dispenser includes a user interface for controlling the operation of the dispenser. Preferably, the processor is prougrammed to actuate different emission durations at different times. 
     Preferably, the dispenser includes an adapter for attaching the dispenser to different types of containers. 
     There is further provided in accordance with a preferred embodiment of the present invention, a dispensing container including: 
     a can containing a fluid; 
     a dispenser head which has an open state in which the fluid is emitted from the can and a closed state in which the fluid is not emitted; and 
     a motor which changes the state of the dispenser head between the open and closed states. 
     Preferably, the dispenser head has a bore therethrough, which receives the fluid from the can, the bore comprising a first part having a first inner diameter and a second part having a second inner diameter, larger than the first inner diameter, wherein the dispenser head includes: 
     a hollow shaft, axially movable within the bore, the shaft having a hole disposed along the length thereof such that when the hole is positioned in the first part of the bore, the fluid does not pass through the shaft, and when the hole is in the second part of the bore, the fluid passes through the shaft and is emitted from the dispenser head. 
     Preferably, the dispenser is portable. 
     In a preferred embodiment, the fluid is dispensed to water a plant. 
     In other preferred embodiments, the fluid includes a deodorant, an insecticide, and/or a smoke-producing material. 
     In a preferred embodiment, the dispenser includes a horn mounted on the dispenser so as to make a sound when the fluid is emitted. 
     Preferably, the fluid is emitted as an aerosol. Preferably, the dispenser includes a hanger for hanging the dispenser such that the dispenser is free to turn. 
     There is further provided in accordance with a preferred embodiment of the present invention, a cooling device including: 
     an insulating case; 
     a pressurized gas container; and 
     a dispenser, arranged to periodically emit the gas from the container into the case in order to cool the interior of the case. 
     Preferably, the device includes a one-way valve for emitting excess gas from the case. 
     Preferably, the excess gas emitted from the case includes gas that is generally warmer than an average temperature of the gas in the case. 
     Preferably, the excess gas emitted from the case includes gas that has been in the case for a generally longer period than most of the gas in the case. 
     Preferably, the insulating case includes passages and the gas emitted from the container leaves the case substantially only through the passages. 
     Preferably, the dispenser is fixed to the container such that the container is in a substantially constantly open position, allowing the gas to pass into the dispenser, and the dispenser emits the gas substantially independently of the gas pressure in the container. 
     Preferably, the dispenser includes an electric motor which drives the dispenser to emit the gas by rotational movements of the motor. 
     Preferably, the device includes a thermostat which actuates emission of the gas. 
     There is further provided in accordance with a preferred embodiment of the present invention, a method for dispensing a material from a container having a valve, including: 
     fixing a dispenser to the container, such that the dispenser holds the valve in a substantially constantly open position, so as to allow the material to pass into the dispenser; and 
     emitting the material from the dispenser substantially independently of the pressure of the material in the container. 
     Preferably, fixing the dispenser to the container includes fixing the dispenser to a container containing a pressurized material. 
     Preferably, the dispenser includes an electric motor, and emitting the material includes actuating the motor so as to cause the material to be emitted. 
     Further preferably, actuating the motor includes driving a rotational movement using the electric motor. 
     Preferably, emitting the material includes emitting the material periodically. 
     Further preferably, emitting the material includes emitting the material at a first rate during a first period and emitting the material at a second rate during a second period. 
     Alternatively or additionally, emitting the material includes emitting the material in response to an external signal. 
     Preferably, emitting the material includes emitting the material in response to a signal received from a sensor. 
     Preferably, emitting the material includes emitting an aerosol. 
     Alternatively or additionally, emitting the material includes emitting a deodorant. 
     Alternatively, emitting the material includes emitting an insecticide. 
     Alternatively or additionally, emitting the material includes emitting smoke. 
     Further alternatively, emitting the material includes watering a plant. 
     Preferably, the method includes hanging the dispenser such that it is free to turn. 
     Preferably, emitting the material includes bringing the dispenser from a closed state to an open state in which the material is emitted from the dispenser, and wherein the dispenser consumes energy substantially only during transition between the open and closed states. 
     There is further provided in accordance with a preferred embodiment of the present invention, a method of maintaining a concentration level of a material within an area including: 
     receiving a signal from a sensing device, in response to the level of the material in the area; and 
     setting an automatic dispenser mounted on a container of the material to operate responsive to the sensor. 
     Preferably, setting the dispenser includes setting the dispenser to operate when the level is beneath a predetermined level. 
     Preferably, the material includes oxygen. 
     There is further provided in accordance with a preferred embodiment of the present invention, apparatus for maintaining a concentration level of a material within an area, including: 
     a container containing the material; 
     a sensor which senses the concentration of the material within the area and generates signals responsive to the concentration; and 
     an automatic dispenser mounted on the container which dispenses the material in response to the signals from the sensor, wherein the apparatus operates substantially independently of any wired or fluid communication with elements other than the sensor, container and dispenser. 
     Preferably, the sensor generates signals responsive to a concentration below a predetermined level. 
     There is further provided in accordance with a preferred embodiment of the present invention, a method of maintaining a low temperature in a volume including controlling an automatic dispenser to automatically emit a gas from a pressurized gas container into the volume. 
     Preferably, directing the dispenser includes setting the dispenser to periodically emit the gas. 
     Alternatively or additionally, directing the dispenser includes directing the dispenser to emit the gas responsive to a temperature sensor. 
     Preferably, the gas includes air. 
     Preferably, the method includes emitting excess gas from the volume which is generally warmer than an average temperature of the gas in the volume. 
     Preferably, the method includes emitting excess gas from the volume which gas has been in the volume generally for a longer period than most of the gas therein. 
     There is further provided in accordance with a preferred embodiment of the present invention, a method of pest control including: 
     mounting an automatic dispenser having a horn head on a Pressurized gas container; and 
     operating the dispenser automatically to periodically emit a portion to the gas in the container so as to operate the horn. 
     Preferably, periodically emitting the gas includes emitting gas in response to detection of a pest. 
     Preferably, periodically emitting the gas includes emitting gas so as to cause movement disturbing to the pest. 
     The present invention will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic perspective view of an automatic dispenser in operation, attached to a container, in accordance with a preferred embodiment of the present invention; 
     FIGS. 2-4 are schematic perspective views of the dispenser of FIG. 1 with various mounting devices, in accordance with preferred embodiments of the present invention; 
     FIG. 5 is an exploded perspective view of the dispenser of FIG. 4; 
     FIG. 6 is a schematic cross-sectional view of the dispenser of FIG. 4 in a closed position; 
     FIG. 7 is a perspective, partly sectional view of the dispenser of FIG. 4, in the closed position; 
     FIG. 8 is a schematic cross-sectional view of the dispenser of FIG. 4 in an open position; 
     FIG. 9 is a perspective, partly sectional view of the dispenser of FIG. 4 in the open position; 
     FIG. 10 is a schematic view of a dispenser which operates on a remote container, in accordance with a preferred embodiment of the present invention; 
     FIG. 11 is a perspective view of a scarecrow utilizing an automatic dispenser, in accordance with a preferred embodiment of the present invention; 
     FIG. 12 is a schematic view of a dispenser with a Venturi jet, in accordance with a preferred embodiment of the present invention; 
     FIG. 13 is a perspective view of a cooler utilizing an automatic dispenser, in accordance with a preferred embodiment of the present invention; 
     FIG. 14 is a perspective view of a cooler utilizing an automatic dispenser, in accordance with another preferred embodiment of the present invention; and 
     FIG. 15 is a schematic diagram illustrating air flow in the cooler of FIG. 14, in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1 shows an automatic dispenser  20  mounted on a pressurized aerosol container  22 , in accordance with a preferred embodiment of the present invention. Dispenser  20  dispenses a material held in the container via an orifice head  38 , which may include a dispensing tube  37 . Dispenser  20  controls the dispensation of the contents, which are preferably dispensed periodically according to user settings. A control panel  30  is preferably situated on a top side of dispenser  20 , to receive user settings of the dispenser&#39;s operation, including the frequency of dispensations and the duration of each dispensation. Preferably, the frequency of dispensation may be between once every sew seconds to once every few days. Alternatively or additionally, dispenser  20  is operated by an external signal originating, for example, from a sensor or a factory line control. 
     Preferably, dispenser  20  has three switches  32 , which allow easy selection of the operation settings by the user. In a preferred embodiment of the present invention, a first switch sets the dispensation duration in tenths of seconds; a second switch selects the units in which the interval between durations is measured, e.g., seconds, minutes, hours, days or weeks; and a third switch sets the length of the interval in the selected units. Preferably, the second switch allows choosing other modes of operation including external control, off, constant and a test mode. It is noted that other controls, including various switches and displays, may also be used to set the dispensation timings, as is known in the art. 
     In some preferred embodiments of the present invention, a wide base  39  is attached to container  22  when it is to be placed on the ground or on another surface. Base  39  prevents container  22  from moving when the material is dispensed therefrom at a high rate. Alternatively, dispenser  20  may be fixed to a pole or wall to prevent turning thereof, as shown for example in FIG.  2 . 
     FIGS. 2-4 show dispenser  20  with various mounting devices therefor, in accordance with a preferred embodiment of the present invention. It is noted that other mounting methods may be used, including methods allowing dispenser  20  to rotate in various patterns as applied, for example, in the sprinkler industry. 
     In a preferred embodiment of the present invention, shown in FIG. 2, dispenser  20  is mounted by a fixed holder  33  having a receiving groove  27  which firmly holds a slit  49  located in dispenser  20  close to orifice head  38 . Thus, dispenser  20  is tightly held and prevented from rotating. 
     FIG. 3 shows another preferred embodiment of the present invention, in which dispenser  20  is mounted on a rotating hanger  31  which rotates together with the dispenser. 
     In a preferred embodiment of the present invention, shown in FIG. 4, dispenser  20  is hung on a hanger  34  in a manner allowing free turning of the dispenser and container relative to the surroundings. Dispensing tube  37  is bent so that when the contents of container  22  are emitted, dispenser  20  revolves around its axis preferably in the direction of arrow  29 , and the contents of the container are distributed all around the dispenser. 
     It is noted that the methods of mounting dispenser  20  described above are shown by way of example and other accessories may be used, including hooks, and double sided tape depending on the specific purpose for which dispenser  20  is used. Preferably, the accessories allow positioning dispenser  20  at any des red orientation, since dispenser  20  may operate in substantially any orientation due to its independence from gravity and other external forces in emitting the material. The descriptors top, bottom, upper, lower, etc., which are used in the following description, refer therefore solely to the orientation of dispenser  20  shown in the figures and are used throughout this description only for the purpose of simplicity. 
     Dispenser  20  forms an air-tight sealed connection with container  22 , such that the contents of container  22  may be dispensed only through dispenser  20 , as described herein. An elastic metal ring  24  at a bottom end  21  of dispenser  20  fits into a groove  26  at the top of container  22 , securing the connection. The connection is preferably released by pressing on handles  25  (FIG. 5) a the edges of ring  24 . Preferably, the connection is capable of withstanding forces of a magnitude of at least 2-4 kg of force to prevent separation of dispenser  20  from container  22  due to the fluid pressure and or inadvertent external pressure. 
     When dispenser  20  is in connection with container  22 , a plunger, which is preferably an integral part of the bottom of the dispenser, presses on an opening valve  28  of the container, so that the valve is held constantly in the open position. The material in container  22  and the pressure it exerts are thus controlled by dispenser  20 , which is compatible with a wide variety of spray containers without dependence on their specific characteristics. 
     Preferably, when mounting dispenser  20  on container  22 , the plunger presses on valve  28  only after a leak tight connection is formed between valve  28  and dispenser  20 . 
     The contents of container  22  enter dispenser  20  at bottom  21  of the dispenser, and leave through an orifice  36  (see FIG. 5) at the top of the dispenser. Orifice head  38  is preferably mounted in orifice  36  to direct the contents leaving the dispenser. Orifice head  38  may have a narrow orifice, suitable for long-range dispensing. Preferably, dispensing tube  37  extends from orifice head  38  leading the contents of container  22  to the surroundings of the dispenser. Alternatively, orifice head  38  may have a wide orifice, suitable for covering a large area at a short range. It well be appreciated that various and other orifice heads, as are known in the art, may be used with the dispenser. 
     FIG. 5 shows an exploded view of dispenser  20 , in accordance with a preferred embodiment of the present invention. Dispenser  20  comprises a case  100  having a cylindrical shape. Preferably, case  100  has a diameter of about 3.9 cm, and a height of about 10 cm. A top piece  102  containing orifice  36 , fits on top of case  100 . Preferably a bulge  43  in top piece  102  defines an upper bore  58  (see FIG. 6) which leads to orifice  36 . Preferably, two slits  103  are defined in case  100  opposite too piece  102  which are sized and positioned to accept ring  24 . 
     A battery peck  81 , preferably comprising three standard batteries, fits into case  100  and supplies power for the operation of dispenser  20 . The material from container  22  is conveyed to upper bore  58  and orifice  36  through a lower bore  50  defined by three cylinder bolts  110 ,  120  and  122 , and a shaft  52 . Preferably, bore  50  and shaft  52  run along the center of dispenser  20 . 
     Shaft  52  contains a long, hollow core  116 , which communicates between bore  50  and bore  58 . Core  116  is open at its top end, leading to orifice  36 , but is closed at its bottom end  118 . At least one hole  90 , preferably at least three such holes, leading into a central lumen  104  of hollow core  116 , are situated radially near the bottom of core  116 , preferably a few millimeters ram bottom end  118 . An O-ring  55  surrounds and seals core  116  within bore  50 , preferably within top bolt  122 , and prevents leakage of the material from container  22  into the interior of dispenser  20 . An additional O-ring  56  is preferably situated around bore  58  to prevent leakage of the material from the bore to the interior of dispenser  20 . Preferably, bolt  122  has a slightly smaller diameter in an area  121  along its length in which it receives O-ring  55 , so that external pressure does not cause damage to the ring. Preferably, shaft  52  comprises a thick section  92  for manipulation of the shaft. Thick section  92  connects to a lever  70  which manipulates shaft  52 , as is In described below. 
     FIGS. 6 and 7 show dispenser  20  in a closed state, in accordance with a Preferred embodiment of the present invention. Bottom bolt  110  of bore  50  serves as the plunger which presses down on valve  28  in order to keep container  22  constantly open. Bottom bolt  110  is shaped and sized to receive valve  28  of container  22  at a lower side  105  of the bolt, such that the contents of the container will flow through valve  28  only into bore  50 . 
     In order to accommodate different sizes of valves  28 , a replaceable adapter  112  may be used to seal the connection between valve  28  and bolt  110 . Alternatively or additionally, bolt  110  may be easily replaced to accommodate the different valves. An O-ring  59  preferably aids in sealing the connection. Preferably, the plunger part of bolt  110  is deep enough within bolt  110  so that valve  28  is pressed only when the valve is sealed within bolt  110 . The contents of container  22  enter bore  50  and do not escape due to the tight fit of valve  28  within bolt  110 . Bore  50  is blocked at its upper end by bottom end  118  of core  116 , which in the closed state is situated within bottom bolt  110 . An O-ring  54  aids shaft  52  in preventing the contents of container  22  from passing from bottom bolt  110  to middle bolt  120 . Preferably, an upper side  114  of bottom bolt  110  has an inner diameter which tightly receives core  116  of shad  52 . 
     Top bolt  122  preferably has an inner diameter of about the same size as that of upper side  114  of bottom bolt  110 , and likewise prevents leakage of the contents of container  22  when shaft  52  is within the bolt. Preferably, shaft  52  is always held within top bolt  122 , although at varying heights, preventing the aerosol from escaping bare  50  through top bolt  122 , into case  100 . 
     Middle bolt  120 , has an inner diameter larger than the outer diameter of core  116 . The larger inner diameter defines a cavity  88  which allows passage of the fluid, as is described below. Thus, the fluid, entering bore  50  can exit the bore only through holes  90  into central lumen  104  of shaft  52 . However, the fluid enters lumen  104  only when holes  90  are within middle bolt  120 , due to the larger inner diameter of bolt  120 . 
     Preferably, bottom bolt  110 , middle bolt  120  and top bolt  122  are held within a channel  130  in case  100 . Channel  130  keeps the bolts defining bore  50  tightly in place. Preferably, an O-ring  57  prevents bolt  110  from sliding within channel  130 . Alternatively or additionally, one or more of bolts  110 ,  120  and  122  may be farmed as an integral part of channel  130 . 
     Lever  70  is connected on one side to section  92  of shaft  52  and on the other side to a screw  74 , which is coupled to a motor  76 . When dispenser  20  is to be moved between open and closed states, motor  76  rotates screw  74 , and lever  70  is moved from one end of screw  74  to the other. Thus, the distance which lever  70  moves together with shaft  52  is determined by the length of screw  74 , and there is no need to precisely control the number of turns rotated by motor  76 . Precise control of the number of rotations of motor  76  requires relatively expensive apparatus that may be too large for a small dispenser. 
     Stoppers may be used at either end of screw  74  to allow precise control of the distance of movement. The stoppers preferably comprise a suitable non-stick material in order to minimize the possibility of locking of the lever against the stopper. 
     Preferably, screw  74  is slightly longer than the maximum distance allowed for movement of shaft  52  between the open and closed states. The extra length is compensated for by flexibility of lever  70 , which bends slightly and leans on screw  74  at both open and closed states. Alternatively, screw  74  is substantially longer than the allowed distance, and section  92  serves as a stopper and prevents movement beyond the maximum allowed distance, when Section  92  meets the lower surface of top piece  102 . 
     Preferably, section  92  includes a slot  94  for receiving lever  70 . Lever  70  comprises a collar  72 , having approximately one turn of an internal thread, which receives screw  74 . Alternatively, the side of lever  70  which fits on screw  74  comprises a step the size of about half a turn of a thread of screw  74 , which easily fits on the screw. Preferably, collar  72  is flexible and large enough to leave leeway, so as not to require accurate fitting of screw  74  to the collar. In both the closed and open states of dispenser  20 , collar  72  is situated at a respective end of screw  74  and exerts a slight bend pressure on the screw. Thus screw  74  reliably enters collar  72 , and there is substantially no risk of collar  72  not fitting back on screw  74 . Preferably, lever  70  comprises a non-abrasive plastic or any other material having similar characteristics. 
     Motor  76  preferably comprises a standard DC motor, whose shaft rotates screw  74 . Alternatively, motor  76  may operate on AC power. Motor  76  is controlled by a processor  78 , which operates according to the user&#39;s settings on control panel  30 . Processor  78  and motor  76  preferably receive power from batteries  80  within dispenser  20 . 
     Alternatively or additionally, dispenser  20  is connected to a local electric line supply. Further alternatively or additionally, processor  78  receives power from a miniature batters separate from the power supply of the motor. As long as motor  76  is not operated, lever  70  does not move and prevents shaft  52  from moving under pressure from container  22 . 
     FIGS. 8 and 9 illustrate dispenser  20  in the open position, in accordance with a preferred embodiment of the present invention. When dispenser  20  is to release a spray of aerosol, processor  78  actuates motor  76 . Motor  76  rotates screw  74  clockwise (as indicated by an arrow  79 ) causing lever  70  to elevate relative to screw  74  and reach the too of screw  74 . Shaft  52  is lifted by lever  70  such that its bottom end  118  is located within enlarged cavity  88  in bore  50 . At this stage, the pressure of container  22  pushes some of its contents into cavity  88 . Hole  90  allows the contents to enter hollow shaft  52  and consequently to move out to the atmosphere, through orifice  36  at the top of dispenser  20 . 
     After the spray has been dispensed for a predetermined time, processor  78  actuates counter clockwise operation of motor  76 , indicated by an arrow  73 , shown in FIG. 7, so as to lower lever  70 . Lever  70  pushes shaft  52  back to the closed state shown in FIGS. 6 and 7, and thus hole  90  is resealed in bottom bolt  110 . Preferably, the movements of screw  74  from one state to another require less than 0.1 seconds in the closed state, bent lever  70  aids in prevention of shaft  52  from moving. 
     The force exerted by the pressure of container  22  on shaft  52  is equal to the cross-sectional area of the inner channel in shaft  52  times the pressure of the container. In a preferred embodiment of the present invention, shaft  52  has an inner diameter of about 1.5 mm and the contents of container  22  are generally pressurized to about 5 atmospheres, so that the force exerted is approximately 90 grams of force. The force required to seal the container is about 0.2 kg of force and the force applied by motor  76  to open/close dispenser  20  is preferably approximately between 0.4-0.5 kgs or force. In comparison pressing on the valve to open the container, would require a force of about 2.5 kgs of force. Thus, dispenser  20  generally consumes much less energy than dispensers known in the art. It is noted that the force applied by motor  76  can be adjusted by changing the length of screw  74  and/or the thickness of lever  70 . 
     The use of rotational movement to move shaft  52  allows the elements of dispenser  20  to be manufactured with relatively low precision. Thus, it is not necessary to use fine mechanical pieces for screw  74  and lever  70 . Also, dispenser  20  does not require gears and cams, which complicate the mechanism and require more accurate design and manufacture. 
     Preferably, hole  90  (or the aggregate of the plurality of such holes) and orifice  36  have approximately the same cross-sectional area. As gas is known to cool upon expansion, this sizing relation will allow gas entering cavity  88  to exit orifice  36  without freezing inside dispenser  20 . 
     Container  22  may contain any of a large variety of liquids or gasses including, for example, air, oxygen, fuels, water, oils, sterilizers, cleaning materials, insecticides and deodorants. It is noted that some poisonous materials and fuels must be emitted in small and accurate amounts in order to prevent damage. Therefore, these materials could not generally be used in prior art dispensers. This limitation is overcome by preferred embodiments of the present invention which emit accurate amounts of material and therefore allow use of these materials. 
     In the above preferred embodiment, dispenser  20  comprises a plurality of parts which are connected together without requirement of screws. For example, slots  106  in battery pack  81 , shown in FIG. 5, facilitate such connection. This embodiment allows easy production and assembling of the dispenser. However, t will be clear to those skilled in the art that the dispenser may comprise fewer or more parts, which may be connected in various manners. For example, as Mentioned above, bore  50  may comprise only one piece instead of channel  130 , and separate bolts  110 ,  120 , and  122 . Also top piece  102  may be manufactured as part of case  100 . 
     In a preferred embodiment of the present invention, not shown in the figures, the orifices of a plurality of dispensers  20  are connected in parallel through a common hose to a single emitting opening. Preferably, dispensers  20  are mounted on containers holding different materials and are operated at the same time, mixing the materials together. Alternatively, the dispensers may have different time settings, such that the same opening emits different materials at different times. 
     In another preferred embodiment of the present invention, also not shown in the figures, dispenser  20  comprises a refill inlet which allows easy refilling of container  22 . FIG. 10 is a schematic illustration showing a dispenser  180 , which operates on a remote container  22 , in accordance with a preferred embodiment of the present invention. A hose  184  connects between container  22  and dispenser  180 . Hose  184  comprises at a first end thereof a connector  186 , which engages valve  28  of container  22 . 
     Preferably, connector  186  is similar to bottom end  21  of dispenser  20  and may include a ring, similar to ring  24  shown in FIG. 1, which strengthens the connection between hose  184  and container  22 . Dispenser  180  is connected to the other end of hose  184  by means of any tube connection known in the art. The use of hose  184  allows the dispenser to be placed in locations where it is not feasible to place container  22 . Thus, it is possible to place large containers  22  in a storage area, while only dispenser  180  is placed in a dispensing area. In a preferred embodiment of the present invention, a plurality of dispensers  180  are connected to container  22 . Alternatively or additionally, a plurality of containers  22  are connected to one or more dispensers  180  via a single hose  184 . Such a setup provides reliable supply of the contents of container  22  even when one container is empty. 
     In a preferred embodiment of the present invention, container  22  contains an insecticide, and dispenser  20  is positioned in mosquito habitats, gardens, greenhouses, or any other location where it is desired to periodically spray against insects. Dispenser  20  is set to operate periodically, for example, once a week, to automatically dispense a quantity of insecticide from within container  22 . Preferably, dispenser  20  is covered by a protective plastic which protects it from weather hazards. Dispenser  20  is preferably positioned before the appropriate season, and container  22  contains sufficient material so that it is not necessary to return for refilling until the next season. Using automatic insecticide dispensation is especially advantageous in those areas where access is difficult and/or costly. 
     FIG. 11 shows an automatic scarecrow  220 , in accordance with a preferred embodiment of the present invention. Scarecrow  220  comprises a pressurized gas container  22  with a dispenser  20  mounted thereon, as described above. A horn orifice head  222  is mounted on dispenser  20 , so that every time dispenser  20  is operated, a burst of gas is emitted causing a noise which scares off birds and other unwanted creatures. Horn orifice head  222  may comprise a simple horn, a whistle, a siren, a rattle, a kazoo, or any other suitable sound maker. Preferably, the gas includes an insecticide which eliminates insects which may attract the birds. A protective shield  226  preferably covers dispenser  20  and protects it from weather hazards. In a preferred embodiment of the present invention, the gas emission also causes ribbons  224  to wave, so as to enhance the effect on the birds Alternatively, an addtional dispenser may be used to cause the ribbons to wave, or produce other moving effects. Scarecrow  220  may be positioned near fish ponds, gardens, orchards, runways or any other desired location. In a preferred embodiment of the invention, horn head  222  emits sound mainly at frequencies which are perceived by animals, but not by humans. 
     In other preferred embodiments of the present invention, dispenser  20  may be positioned within a small doll-shaped scarecrow, preferably mounted on a rotatable hanging device, which is hung on a tree in order to scare off pests from the tree. 
     In some preferred embodiments of the present invention, dispenser  20  is used to maintain a minimal level of a material in its surroundings. Preferably, dispenser  20  operates responsive to a sensor which measures the level of the material in the surroundings. Each time the level goes below a predetermined threshold, dispenser  20  is operated to emit a quantity of the required material from within container  22 . Specific preferred embodiments include maintaining a required smog (for example, to maintain a desired temperature, as is known in the art) or humidity level, particularly within a greenhouse, or an oxygen level in the proximity of a patient. 
     FIG. 12 schematically shows one way to use dispenser  20  for humidity control, in accordance with a preferred embodiment of the present invention. Dispenser  20  is mounted on container  22  containing pressurized gas, preferably air. The orifice of dispenser  20  is connected through a Venturi Jet  234  to a water vessel  230 . Each time the dispenser operates, water from vessel  230  is sprayed into the surrounding air. Preferably, dispenser  20  is operated responsive to a humidity sensor  232 , in order to maintain a minimal humidity level, or a humidity pattern, within the vicinity of dispenser  20 . Alternatively, the water from vessel  230  may be used to periodically automatically water plants. 
     FIG. 13 shows a cooler  250 , in accordance with a preferred embodiment of the present invention. Cooler  250  comprises dispenser  20  and container  22 , containing a pressurized gas, preferably air, which upon expansion cools and maintains a low temperature within cooler  250 . 
     Preferably, dispenser  20  is operated periodically at intervals set according to the environmental temperature. Alternatively or additionally, a temperature sensor  252  initiates the operation of dispenser  20  when the temperature within cooler  250  is above a predetermined threshold. 
     Preferably, the air is allowed out of cooler  250  Ad through a one-way valve  254 , which is preferably situated such that the air which leaves cooler  250  is relatively warm air, rather than the cold air which was recently emitted by dispenser  20 . It is noted that cooler  250  may be of a variety of sizes, and may similarly comprise a canteen, for cooling water or another drink. 
     FIGS. 14 and 15 show a cooler  260 , in accordance with another preferred embodiment of the present invention. Cooler  260  is similar to cooler  250 , but the air flow out of cooler  260 , as illustrated in FIG. 15, is planned particularly so as to enhance the cooling effect of the cold gas from dispenser  20 . Cooler  260  comprises double walls  261  which enclose a passage  262 , which provides thermal insulation. When air is emitted from container  22  into cooler  260 , air is not randomly let out of the cooler, but rather the warmest air, near the top of the cooler is pushed out through passage  262 . Preferably, the air which is in the cooler for the longest period is emitted. This air flow scheme is reinforced by having the path to one-way valve  254  run all through passage  262 . 
     In other preferred embodiments of the present invention, not shown in the figures, gas in container  22  is used to open and close valves or switches in remote locations or otherwise operate remote systems, for example to automatically launch weather balloons. The use of dispenser  20  as a timing device provides a cheap and reliable method of automatic operation of remote systems, reducing the necessity of access to the system. 
     In some preferred embodiments of the present invention, not shown in the figures, container  22  contains a fuel, and a flare head is mounted on orifice  36 . A spark generator is preferably coupled to dispenser  20 , so that the flare is lit up each time dispenser  20  is operated. 
     In another preferred embodiment of the present invention, container  22  contains a fire extinguisher. Dispenser  20  is coupled to a temperature sensor or smoke sensor so as to emit the contents of the container if a fire is detected. 
     In a preferred embodiment of the present invention, container  22  contains an anti-vaporizing material which is emitted periodically in suitable locations. 
     In some preferred embodiments of the present invention, container  22  contains tear gas or other noxious material, and functions as an anti-intrusion device. Dispenser  20  is positioned within a car, for example, and operates if a theft condition is detected. 
     In some preferred embodiments of the present invention, container  22  contains a colorful smoke material, which is preferably used for signaling purposes. The smoke is emitted from dispenser  20  according to predetermined time settings. Preferably, the emitted smoke also operates a fog-horn as it is emitted. Thus, dispenser  20  may be used, for example, to mark a destination point in navigation. 
     It will be appreciated that although in the above embodiments, dispenser  20  is used with a pressurized container the present Invention may be implemented with non-pressurized containers, for example, for watering plants. In such embodiments the container is preferably positioned upside-down, so that the contents of the container are released due to gravity. 
     Other possible arrangements of the elements of the above-described preferred embodiments will also be apparent to those skilled in the art and are included within the scope of the present invention. For example, elements of shaft  52  (FIG. 6) may be reversed so that hole  90  is positioned within upper bore  58 , and controls the outflow of fluid from the shaft, rather than controlling influx into the shaft as described above. It will be appreciated that the preferred embodiments described above are cited by way of example.