This invention relates to the field of pressurized tank sprayers used for dispensing a fluid from a tank.
Pressurized tank sprayers are common tools in households throughout the world. These tank sprayers are typically used by individuals to disperse chemicals for lawn care, pest control, or other residential concerns.
Pressurized tank sprayers typically include a tank for holding chemicals and a lid that seals the tank air-tight. A hand pump is generally incorporated on the apparatus for introducing air into the sealed tank. Also, a hose is provided for channeling chemicals within the tank to a nozzle attached to the end of the hose. The user operates the hand pump to force air into the sealed tank, thereby increasing the pressure in the tank. The increased pressure in the tank forces the chemicals or other liquid in the tank through the hose and out the nozzle when the nozzle is operated.
A number of potential problems exist with the design of typical tank sprayers. First, if the tank is not adequately sealed, it will not retain pressure and will not be able to force liquid through the hose and out the nozzle. Therefore, a good seal between the lid and tank is required. O-ring seals are often used to provide the seal between the lid and the tank in pressurized tank sprayers. A significant amount of force is typically required to adequately compress the O-ring and establish a seal in these sprayers. Unfortunately, many individuals are not strong enough to compress the lid to the tank in a manner that provides a good O-ring seal. Accordingly, it would be desirable to provide a pressurized tank sprayer requiring less force to properly seal the lid to the tank.
Another problem with previous pressurized tank sprayers is that a user of the sprayer may fail to open the pressure relief valve and relieve the pressure from the tank before attempting to remove the lid from the tank. When the user forgets to properly relieve the increased pressure in the tank before attempting to remove the lid, the pressure within the tank may cause the lid to become forcibly detached from the tank during such removal attempt. Therefore, it would be desirable to provide a pressurized tank sprayer having a safety feature that automatically relieves excess pressure within a tank when a user is attempting to remove the lid from the pressurized tank.
A pressurized tank sprayer with annular seal comprises a tank, a removable lid and an annular seal. The tank includes an interior surface and an exterior surface. A mouth is formed in the tank and provides communication between the interior and the exterior of the tank. The tank further includes a neck portion that leads to and defines the mouth. The removable lid is secured to the tank and covers the mouth. The removable lid includes a top with a depending skirt. The removable lid also includes an annular groove designed to receive the annular seal.
The annular seal is disposed between the tank and the lid when the lid is positioned upon the tank. The annular seal includes a collar that is retained by the annular groove on the lid. The annular seal also includes an annular sealing surface and an interior concave surface. The annular sealing surface and the interior surface of the lid skirt define an annular channel that receives the neck portion of the tank when the removable lid is secured upon the tank. In particular, when the neck portion of the tank is positioned in the annular channel, an exterior surface of the neck portion contacts the interior surface of the skirt and an interior surface of the neck portion contacts the annular sealing surface of the annular seal. The interior concave surface of the annular seal is exposed to the interior of the tank when the lid is secured to the tank.
In one embodiment, the exterior surface of the neck portion of the tank includes a first plurality of threads, and the interior surface of the lid skirt includes a second plurality of threads. The first plurality of threads is operable to move in rotatable engagement relative to the second plurality of threads. Also, the first plurality of threads is operable to move in rotatable disengagement relative to the second plurality of threads. The first plurality of threads and the second plurality of threads include means for permitting an axial shift of the first plurality of threads relative to the second plurality of threads in response to an increased pressure within the tank during rotatable disengagement of the first plurality of threads relative to the second plurality of threads. This axial shift permits the increased pressure to be released from the tank without disengagement of the first plurality of threads from the second plurality of threads.
With reference to
The tank 14 includes an exterior surface 30 and an interior surface 32. The tank is designed to hold liquid to be sprayed from the tank. The tank interior surface 32 defines a chamber 34 having a volume for holding liquid. The tank includes a lower body portion 36 and a neck 38. The neck 38 is generally tapered or otherwise smaller in diameter than the lower body portion 36 of the tank. However, one of ordinary skill in the art will recognize that the neck 38 may have a diameter equal to the lower body portion 36, or may be flared with a diameter greater than the lower body portion. A plurality of threads 50 are disposed upon and spiral around the neck 38. The top of the neck 38 leads to a top rim 40. The top rim 40 defines a mouth 42. The mouth 42 provides an opening between the interior of the tank and the exterior of the tank. This opening is used for communication of liquids into or out of the tank chamber 34. The tank is generally comprised of a lightweight material such as plastic. However, the tank may also be comprised of any number of other materials suitable for holding liquid, such as glass or metal.
A side carry handle 44 may be included on the tank, as is shown in
With reference to
The pressure relief port 64 is designed and dimensioned to receive a pressure relief valve 70. The pressure relief valve includes a lever 72 operable to open and close the pressure relief valve 70. The lever pivots 180° about a pivot point 74 between an open position and a closed position. When the lid 16 is secured to the tank 14 and the lever is in the open position, the pressure relief valve 70 is open. With the pressure relief valve open, a passage is provided allowing pressurized air/gas within the tank to escape the tank through the pressure relief valve 70. On the other hand, when the lever 72 is in the closed position, the pressure relief valve 70 is closed. With the pressure relief valve 70 closed, the passage through the pressure relief valve 70 is blocked, thereby preventing pressurized air/gas within the tank from escaping the tank though the pressure relief valve.
The pump opening 66 in the lid 16 is designed and dimensioned to receive a pump plunger 78 and pump cap 80. The pump opening 66 feeds into an elongated pump cylinder 76 integrally formed with the lid 16. The pump cylinder 76 extends downward into the interior of the tank 14 when the lid 16 is placed on the tank. A plurality of holes 86 are formed at the bottom of the pump cylinder 76. The cap 80 fits over the pump opening 66 in the lid and is fixed to the lid to secure the pump plunger 78 on the lid. The pump plunger 78 slideably engages the cap 80, allowing the plunger 78 to move up and down with respect to the lid 16 and the cap 80. A piston 82 is attached to the bottom end of the plunger 78 and is retained within the cylinder 76. A handle 84 is attached to the top end of the plunger. The handle allows manual operation of the pump. In particular, upward movement of the handle 84 moves the plunger 78 and attached piston 82 upward within the cylinder 76. As the piston 82 is moved upward, a valve (not shown) positioned upon the piston allows air to rush into the cylinder on the bottom side of the piston. Thereafter, downward movement of the handle forces the plunger and attached piston downward in the cylinder. When the piston moves downward, the valve is closed, forcing air out of the holes 86 in the bottom of the cylinder. In this manner, air may be forced into the tank 14 in order to pressurize the tank.
With continued reference to
The fluid outlet port 68 is also positioned on the top of the lid 16 and provides an opening in the lid. The tube 24 extends through the bottom side of the fluid outlet port 68. The cylinder 76 includes an exterior track 88 for receiving the tube and holding it in place within the tank. A screen filter 90 is positioned at the bottom of the tube 24 for blocking solid particles from passing into the tube that may be large enough to clog or otherwise damage the nozzle 28. One end of the hose 26 is attached to the nozzle 28. The opposite end of the hose is attached to the top of the exterior surface of the fluid outlet port 68. A clamp 92 is used to secure the hose 26 to the fluid outlet port 68.
The skirt 62 of the lid 16 depends from the top 60 of the lid in an annular fashion. The skirt includes an interior surface 101 and an exterior surface 103. The interior surface 101 of the skirt defines a portion of an interior lid surface 102, and the exterior surface 103 of the skirt defines a portion of an exterior lid surface 104. The exterior lid surface 104 includes handles 108 as well as a plurality of gripping bars 106. The handles 108 may be used to carry the pressurized tank sprayer 12, and may also be used along with the gripping bars 106 when twisting the lid 16 on or off of the tank 14.
The interior lid surface 102 is best viewed with respect to
With reference to
With reference to
As shown in
With the lid 16 secured on the tank 14, the annular seal 120 is in contact with and sealed against the tank interior surface 32, as discussed above. Accordingly, the U-shaped interior surface 132 of the annular seal 120 is exposed to the interior of the tank along with the associated annular trench 138. When pressure is introduced into the tank interior that is greater than the atmospheric pressure experienced on the outside of the tank, the pressure provides an outward force on the interior surface of the tank. This pressure also provides an outward force on the U-shaped interior surface 132 of the annular seal, since it is exposed to the tank interior. The outward force on the interior surface 132 of the annular presses the annular sealing surface 136 against the interior surface of the tank 32 and helps maintain the seal between the lid 16 and the tank 14 when the tank is pressurized.
In order to remove the lid 16 from the tank 12, the lid is rotated relative to the tank such that the threads move in rotational disengagement. As the lid is removed, the neck 38 of the tank is moved out of the annular channel 144. After the neck passes out of the annular channel 144, and the seal 120 is completely disengaged from the interior surface of the neck 38, the resilient exterior lip 128 of the seal shifts away from the annular trench 138 and returns to its equilibrium position.
In one alternative embodiment, the pressurized tank sprayer includes a locking thread feature that allows excess pressure inside the tank that is greater than atmospheric pressure to escape the tank before the threads on the tank and the threads on the lid are completely disengaged. With reference to
The neck threads 50 are formed on the exterior surface of the neck of the tank, are helical in shape, and spiral downward around the neck. Each neck thread includes a starting portion 158 at one end of the thread nearest the mouth, and an ending portion 58 at the opposite end of the thread. Also, each neck thread includes a mouth side 52 and a bottom side 54. A plurality of grooves 56 are formed between the neck threads such that a groove is formed between the bottom side of a thread and the mouth side of an adjacent thread. The grooves 56 expose the surface of the tank between the neck threads and provide tracks for receiving the skirt threads on the lid. The neck threads typically have a V-shaped cross-section, with the tip of the V pointing away from the tank. However, the threads may have other cross-sectional shapes, as will be readily recognized by those of skill in the art.
A recess 160 is formed in the starting portion 158 of each neck thread 50. Each recess 160 has a depth that extends from the bottom side 54 of the thread toward the mouth side 52, and exposes additional exterior surface of the neck where the thread would otherwise be. Each recess 160 separates a starting tip 164 of each neck thread from the remainder of the thread. A bridge portion 162 is positioned above each recess 160 to connect the starting tip 164 to the remainder of the thread. Thus, each neck thread 50 remains continuous from start to finish, as the bridge portion 162 spans across the recess in each thread. With continued reference to
The skirt threads 110 are formed on the interior surface of the skirt 62. The skirt threads 110 are helical in shape and spiral upward around the skirt interior. Each skirt thread 110 includes a starting portion 180 at one end of the thread nearest the bottom of the skirt, and an ending portion 182 at the opposite end of the thread nearer the top of the skirt. Also, each skirt thread 110 includes a top side 184 and a bottom side 186. A plurality of grooves 188 are formed between the neck threads 110 such that a groove is formed between the bottom side 186 of one thread and the top side 184 of an adjacent thread. The grooves 188 expose the interior surface of the lid between the skirt threads and provide tracks for receiving the neck threads 50 on the tank. Like the neck threads, the skirt threads 110 typically have a V-shaped cross-section, with the tip of the V pointing inward from the annular skirt. However, the threads may have other cross-sectional shapes, as will be readily recognized by those of skill in the art.
A cut-out portion 190 is formed in each skirt thread 110 near the starting portion 180 of the thread. The cut out portion 190 forms a void in the path of the thread 110 and exposes the interior surface 101 of the skirt where the thread would otherwise be. The cut out portion 190 extends from the bottom side 186 of the thread 110 to the top side 184 of the thread. Each thread separates a starting tip 194 of the thread from the remainder of the thread. Because of the cut out portions 190 in the skirt threads 110, and because no bridges span across the cut out portions 190, the skirt threads are not continuous from start to finish.
The arrangement of the recesses 160 in the neck threads 50 and cut-out portions 190 in the skirt threads 110 provide the pressurized tank sprayer with a locking thread feature that permits and axial shift between the neck threads and the skirt threads. This axial shift allows excess pressure inside the tank that is greater than atmospheric pressure to escape the tank before the threads on the tank and the threads on the lid completely disengage. In particular, when the lid 16 is rotated in a counter-clockwise direction relative to the tank 14, the skirt threads 110 will begin rotational disengagement from the neck threads 50 as the lid begins to remove from the tank. If pressure remains in the tank when the lid 16 is being removed from the tank 14, the pressure in the tank will tend to force the lid away from the mouth of the tank. Accordingly, the top side 184 of the skirt threads 110 will be forced upward against the bottom sides 54 of the neck threads 50. However, just before the skirt threads 110 disengage from the neck threads 50, the starting portions 158 of the neck threads 50 will encounter the starting portions 180 of the skirt threads 110. As the starting tips 194 on the starting portions 180 of the skirt threads 110 encounter the recesses 160 on the neck threads 50, the pressure in the tank will force the starting tips 194 upward into the recesses 160. At the same time, the cut out portions 190 on the skirt threads 110 will receive the starting tips 164 of the neck threads 50. As the starting tips 194 on the lid engage the recesses 160 on the tank and the starting tips 164 on the tank engage the cut-out portions on the lid, the pressure in the tank causes the lid to shift axially upward and away from the tank without complete disengagement of the threads. This axial shift is represented in
In general operation of the pressurized tank sprayer 12, the tank is first filled with a liquid to be dispensed from the nozzle 28. When the lid 16 is to be secured on the tank 14, the lid is placed over the mouth of the tank and the lid is rotated in the clockwise direction. Clockwise rotation of the lid causes the starting tips 194 of the skirt threads 110 to enter the grooves 56 on the neck. As the lid is rotated, the bottom side 186 of the skirt threads typically rest on the top or mouth side 52 of the neck threads because of the downward pull of gravity. Continued clockwise rotation causes the neck threads and skirt threads to fully engage as the top rim 40 of the tank becomes seated in the annular channel 144 formed in the lid, as shown in
Once the lid is secured to the tank, the annular seal 120 provides a seal between the lid and the tank. Because the tank is sealed, air is prevented from escaping from the tank. The user then operates the pump 18 to introduce additional air into the tank. The additional air introduced into the tank increases the pressure within the tank. As explained previously, as pressure increases within the tank the pressure provides a force against the concave interior surface 132 of the annular seal 120, thereby maintaining secure contact between the annular sealing surface 136 and the skirt interior surface 103. The increased pressure within the tank forces liquid through the tube 24 and out of the nozzle 28 when the user operates the nozzle.
Following use of the pressurized tank sprayer 12, the user opens the pressure relief valve 20 to remove excess pressure from the tank. The user then rotates the lid in a counter-clockwise direction to remove the lid from the tank. However, as discussed previously, if the user fails to open the pressure relief valve before removing the lid, the locking features of the threads, including the recesses and cut-outs on the starting portions prevent the lid from becoming forcibly detached from the tank.
Although the present invention has been described with respect to certain preferred embodiments, it will be appreciated by those of skill in the art that other implementations and adaptations are possible. Moreover, there are advantages to individual advancements described herein that may be obtained without incorporating other aspects described above. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiments contained herein.
Number | Date | Country | |
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Parent | 10933973 | Sep 2004 | US |
Child | 12217929 | US |