Abstract:
An assembly including a pump attachment particularly adapted to form an nonaerosol pump sprayer, and a method of using the same. The apparatus desirably includes an attachment having a pump sprayer which is pressurized on the upstroke enabling the sprayer to be shipped and stored in a relaxed position. The attachment includes a body, a coupling, a shaft, a piston, an inlet valve and a biasing member. The body defines an elongate chamber having the first end, second end, and an interior wall extending between the first end and second end. The coupler is sized and shaped to secure the body to the neck of a container. The shaft extends through the opening in the first end of the chamber and defines an internal flow channel. The piston is reciprocally mounted within the chamber and includes an inner annular surface surrounding the shaft and an outer annular surface sized and shaped to form a sealing engagement with the interior wall of the body. The attachment defines a sealing surface substantially fixed with respect to the piston and a second sealing surface substantially fixed with respect to the shaft. The first sealing surface and the second sealing surface having the first position wherein the first sealing surface and the second sealing surface cooperate to prevent the flow of liquid between the piston and the shaft. The first sealing surface and the second sealing surface also has a second position wherein the first sealing surface and the second sealing surface permit the flow of liquid between the piston and the shaft. The piston is formed from a single piece said piston and defines an inner annular surface surrounding the shaft and an upper outer annular surface sized and shaped to form a sealing engagement with said interior wall of the body and a lower outer annular surface sized and shaped to form a sealing engagement with the interior wall of said body.

Description:
RELATED APPLICATIONS 
     This application is a continuation of 08/949,837 filed Oct. 14, 1997, U.S. Pat. No. 6,089,414 which is a continuation-in-part of U.S. patent application Ser. No. 08/812,790, filed Mar. 6, 1997 now U.S. Pat. No. 5,816,447. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to pumps and, in particular, to nonaerosol pump sprayers. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Noncontainer pressurizing pump sprayers commonly utilize an integral cylinder and plunger arrangement to generate pressure to expel liquid, such as insecticide and fertilizer from a container. Noncontainer pressurizing pump sprayers are desirable in that they do not utilize pressurized containers which must be handled carefully and at controlled temperatures to avoid the risk of explosion. Noncontainer pressurizing pump sprayers have a number of other advantages, including not using propellants which destroy the ozone and being relatively inexpensive. 
     There are two common varieties of noncontainer pressurizing pump sprayers: pump sprayers that are pressurized on the upstroke and pump sprayers that are pressurized on the downstroke. Pump sprayers that are pressurized on the downstroke typically utilize a return spring which biases the plunger upward after the pressurization stroke. These sprayers suffer from the drawback that it is often undesirable to store or ship the pump sprayer with the plunger in the up position. Accordingly, the pump sprayer is generally shipped and stored with the return spring in a compressed position, causing the spring to fatigue and begin to wear out prematurely. Likewise, in the event of the inadvertent release of the return spring, the plunger cannot be depressed without pressurizing the fluid in the container. In the case of insecticide or other toxic chemicals, this is often undesirable. 
     While pump sprayers that are pressurized by pulling the plunger upward have the advantage of not having the plunger being forced outward inadvertently, they too, suffer from a number of drawbacks. For example, once the plunger is drawn upward, it is generally not possible to lower the plunger without discharging fluid. As drawing the plunger upward creates a relatively large volume of pressurized liquid, this either requires that a relatively large amount of fluid be wasted or the device be stored with the plunger extending outward. 
     U.S. Pat. No. 4,174,055, to Capra, et al., discloses an alternative dispenser. The disclosed dispenser incorporates a plunger which pressurizes the fluid on the upstroke, but also is provided with a separate return spring and collar for purposes of lowering the plunger handle independently of the main plunger piston. While this arrangement has advantages, it is more complicated and expensive than other pump sprayer arrangements. Further, while the system provides for slow bleeding off of pressure, the sprayer remains in a pressurized state for some time. Significantly, this substantially increases the risk of inadvertent discharge of chemicals by adults or children who may come into contact with the device. 
     The present invention includes an apparatus and pump attachment particularly adapted to form a noncontainer pressurizing pump sprayer which overcomes the drawbacks of the prior art. The apparatus desirably includes an attachment having a pump sprayer which is pressurized on the upstroke, enabling the sprayer to be shipped and stored in a relaxed position. Importantly, however, the plunger is adapted to permit the plunger to be quickly and easily lowered and the apparatus depressurized without discharging fluid. Significantly, these advantages are provided in a apparatus which is particularly adapted to be inexpensively manufactured and includes few moving parts, to enhance reliability. 
     One aspect of the invention is a pump attachment for a container defining a neck including a body, a coupling, a shaft, a piston, an inlet valve and a biasing member. The body defines an elongate chamber having a first end, a second end, and an interior wall extending between the first end and the second end. The coupler is sized and shaped to secure the body to the neck of a container. The shaft extends through the opening in the first end of the chamber and defines an internal flow channel. The piston is reciprocally mounted within the chamber and defines an inner annular surface surrounding the shaft and an outer annular surface sized and shaped to form a sealing engagement with the interior wall of the body. The piston separates the chamber into an upper portion above the piston and lower portion below the piston. The inlet valve is at the second end of the body and is configured to permit the flow of fluid into the chamber and restrict the flow of fluid out of the chamber. The biasing member is positioned between the piston and the first end of the chamber. 
     The attachment defines a first sealing surface substantially fixed with respect to the piston and a second sealing surface substantially fixed with respect to the shaft. The first sealing surface and the second sealing surface have a first position wherein the first sealing surface and the second sealing surface cooperate to prevent the flow of liquid between the piston and the shaft. The first sealing surface and the second sealing surface have a second position wherein the first sealing surface and the second sealing surface permit the flow of liquid between the piston and the shaft. 
     Advantageously, the shaft includes an outwardly extending surface which prevents the piston from sliding beyond the one end of the shaft. Likewise, the attachment desirably includes a first O-ring mounted on the shaft which defines the second sealing surface and an inwardly tapered seat which defines the first sealing surface. Alternatively, the piston may comprise one piece and define an upper outer annular surface sized and shaped to form a sealing engagement with the interior wall of the body and a lower outer annular surface sized and shaped to form a sealing engagement with the interior wall of the body. Desirably, the upper outer annular surface is defined by an upper lip adapted to flex outward in response to downward pressure and the lower outer annular surface is defined by a lower lip adapted to flex outward in response to upward pressure. 
     The attachment may also include a spray nozzle communicating with the internal flow channel and an actuator for selectively preventing the flow of a fluid through the spray nozzle. 
     The attachment desirably includes a handle secured to the shaft and a latch movable between a first location wherein the latch generally prevents the shaft from being drawn through the first end of the body and the second location wherein the latch generally permits the shaft to be drawn through the first end of the body. Alternatively, the handle is integrally formed with the shaft so as to form a single piece plunger, thereby eliminating a potential leak point. 
     Another aspect of the invention is an apparatus including a container defining a neck and an attachment. The attachment includes a body, a coupler, a shaft, a piston, an inlet valve, and a biasing member. The body defines an elongate chamber having a first end, a second end and an interior wall extending between the first end and the second end. The coupler is sized and shaped to secure the body to the neck of the container. The shaft extends through an opening in the first end of the chamber and defines an internal flow channel. The piston is reciprocally mounted within the chamber and defines an inner annular surface surrounding the shaft and an outer annular surface sized and shaped to form a sealing engagement with the interior wall of the body. The piston separates the chamber into an upper portion above the piston and a lower portion below the piston. The inlet valve at the second end of the body is configured to permit the flow of fluid into the chamber and restrict the flow of fluid out of the chamber. The biasing member is positioned between the piston and the first end of the chamber. 
     The attachment includes a first sealing surface substantially fixed with respect to the piston and a second sealing surface substantially fixed with respect to the shaft. The first sealing surface and the second sealing surface have a first position wherein the first sealing surface and the second sealing surface cooperate to prevent the flow of liquid between the piston and the shaft. The first sealing surface and the second sealing surface have a second position wherein the first sealing surface and the second sealing surface permit the flow of liquid between the piston and the shaft. 
     Another aspect of the invention is a method of arming and disarming a spray apparatus, including a container containing fluid and an attachment mounted thereto having a body defining an elongate chamber, a shaft extending through an opening in the chamber, the shaft defining an internal flow channel, a piston reciprocating mounted in the chamber, a check valve and a biasing member, including (1) moving the shaft in a first direction relative to the body, thereby moving the piston in the direction and drawing fluid from the container into the chamber through the check valve and compressing the biasing member; (2) permitting the biasing member to force the piston against the fluid in the chamber in a second direction pressurizing the fluid; (3) releasing liquid from the chamber through the internal flow channel in the shaft; and (4) moving the shaft in a second direction relative to the body and the piston to release a seal between the piston and the shaft; thereby permitting the flow of fluid between the piston and the shaft depressurizing the fluid. 
     Another aspect of the invention is a spray nozzle including a grip, a nose having a spray end, a valve housing, a valve and an actuator. The actuator is connected to the valve. The valve housing is mounted within either the grip or the nose. The valve housing defines a closed end, an inlet port and an outlet port. The valve is mounted within the housing and has a flow portion, a first seal on one side of the flow portion and the second seal on the other side of the flow portion. The valve has a first position wherein the valve prevents the flow of fluid between the inlet port and the outlet port, and a second position wherein the valve permits the flow of fluid between the inlet port and the outlet port. The first seal and the second seal are positioned to one side of the inlet port when the valve is in the first position. The first seal and the second seal are positioned on opposite sides of the inlet port and the outlet port when the valve is in the second position. Desirably, the valve comprises a one-piece shaft member and no more than two O-rings. 
     Yet another aspect of the invention is an assembly for a container. The assembly includes a grip, a coupler sized and shaped to secure the grip to the neck of a container, a plug and an adaptor. The grip includes a handle portion and a stem portion. The handle portion has a first inner wall defining a first flow channel having a first outlet. The stem portion defines a second inner wall defining a second flow channel having a second outlet. The first flow channel and the second flow channel intersect at the outlet of the second flow channel. The plug is mounted within the first flow channel and has a first position wherein the plug prevents fluid flow from the second outlet to the first outlet, and a second position wherein the plug permits fluid flow from the second outlet to the first outlet. The adaptor has an inner section sized and shaped to be inserted into the first flow channel to move the plug between the first position and the second position. Desirably, the plug further includes an inner flow channel through which fluid is flowable when the plug is in the second position. The adaptor preferably comprises a connector for securing a piece of tubing to the handle portion of the grip. 
     Finally, yet another aspect of the invention is an assembly including a container and a sprayer. The container defines a wall, a first stud and a second stud. Each of the first stud and the second stud include a head portion and a stem portion. The sprayer has a spray end and a wall. The wall defines a first opening and a second opening. Each of the openings includes a first portion wider than the stem portion and narrower than the head portion, and a second portion wider than the head portion so that the head portion of the stud is insertable therethrough. Advantageously, the container includes a seam and the first stud and the second stud intersect the seam. Preferably, the second portion of the opening is positioned closer to the spray end than the first portion of the opening. Desirably, for each of the first stud and second stud, the head portion overhangs the stem portion a first overhang distance on a first side, and a second overhang distance on a second side. At least one of the first overhang distance and the second overhang distance is advantageously at least 0.015 of an inch. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other aspects of the invention will now be discussed in connection with the accompanying drawings, which form a part hereof. 
     FIG. 1 is a vertical sectional view of an apparatus including a pump attachment, in accordance with a preferred embodiment of the invention, showing the parts in their normal at-rest position. 
     FIG. 1 a  is an enlarged sectional view of the area with the circle  1   a — 1   a  of FIG.  1 . 
     FIG. 1 b  is an enlarged sectional view of the area within the circle  1   b — 1   b  of FIG. 1 a , illustrating an open vent passage. 
     FIG. 1 c  is an enlarged sectional view similar to FIG. 1 b , but illustrating a closed passage. 
     FIG. 1 d  is an enlarged sectional view similar to FIG. 1 a , but showing the handle plug used during shipping. 
     FIG. 1 e  is an enlarged view of a locking ring used by the adaptor. 
     FIG. 2 is a vertical sectional view of the device of FIG. 1, showing the actuator moved to an upwardly or outwardly telescoped position relative the container in order to move the piston in the accumulating chamber or reservoir to compress the biasing member and pressurize fluid within the chamber. 
     FIG. 3 is a sectional view taken along  3 — 3  of FIG. 2, illustrating the latch in an unlocked position. 
     FIG. 4 is a sectional view similar to FIG. 3, but illustrating the latch in a locked position. 
     FIG. 5 is a partial sectional view illustrating the pump attachment in a fully pressurized position. 
     FIG. 6 is a partial sectional view illustrating the release of pressure in the chamber by means of an external downward force on the handle. 
     FIG. 6 a  is an enlarged sectional view of the area  6   a  — 6   a  of FIG. 6 illustrating the flow of fluid between the outer surface of the shaft and the inner annular surface of the piston. 
     FIG. 7 illustrates the pump attachment in its fully locked and retracted position quickly depressurizing through the flow of fluid between the shaft and the piston. 
     FIG. 8 is a view similar to FIG. 6 a  illustrating a first alternative piston design. 
     FIG. 9 is an enlarged sectional view of a second alternative piston design. 
     FIG. 9 a  is a top plan view of the piston of FIG.  9 . 
     FIG. 9 b  is a bottom plan view of the piston of FIG.  10 . 
     FIG. 10 is an enlarged sectional view of a third alternative piston design. 
     FIG. 11 is a sectional view of an alternative handle and shaft design, where the handle and shaft are integrally formed. 
     FIG. 12 is a perspective view of a prior art container and sprayer assembly. 
     FIG. 13 is an enlarged view of the sprayer of the assembly of FIG.  12 . 
     FIG. 14 is a sectional view illustrating the connection between the sprayer and container of FIG. 12, when the sprayer is mounted on the container. 
     FIG. 15 is a front elevational view of a preferred apparatus including a cutout illustrating the manner in which the sprayer is mounted on the container. 
     FIG. 16 is a left side view of the container of FIG. 16, without the spray attachment mounted thereon. 
     FIG. 17 is an enlarged schematic sectional view illustrating the method of molding the container of FIG. 15, including a bayonet attachment. 
     FIG. 18 is a top plan view of an alternative sprayer. 
     FIG. 19 is a front elevational view of the sprayer of FIG.  18 . 
     FIG. 20 is a sectional view of the sprayer of FIG. 18 taken along  20 — 20 . 
     FIG. 21 is a sectional view of the sprayer of FIG. 19 taken along  21 — 21 . 
     FIG. 22 is an enlarged partial sectional view of the valve mechanism of a sprayer in a closed position. 
     FIG. 23 is a partial sectional view of the valve mechanism in an open position. 
     FIG. 24 is a partial sectional view of an alternative valve mechanism in a closed position. 
     FIG. 25 is an enlarged partial sectional view of the sprayer of FIG. 24 in an open position. 
     FIG. 25 a  is an enlarged sectional view along  25   a  — 25   a  of FIG.  25 . 
     FIG. 26 is an enlarged partial sectional view illustrating a second alternative embodiment of the valve mechanism of a sprayer in a closed position. 
     FIG. 27 is a partial sectional view of the valve of FIG. 26 in an open position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIG. 1, an assembly  10  will now be described. The assembly  10  includes a container  20  and pump attachment  30 . The container  20  is illustrated partially filled with fluid  260 . The container  20  defines an internal space or reservoir  22  and a neck  24  which defines an opening or port  26 . The neck  24  desirably defines a series of external threads  28 . 
     The attachment  30  includes a body  40 , which is secured on the container  20  by means of a coupler  70 . The attachment further includes a shaft  110  which is connected to a piston  130 . A handle  190  is mounted on the shaft  110 . A wand or spray nozzle  220  is connected to the handle  190  by tubing  222 . Advantageously, the nozzle  220  includes a release valve, which controls the flow of fluid through the spray nozzle  220  and an actuator  240  for controlling the release valve. 
     Referring to FIG. 5, the body  40  of the attachment  30  will now be described in detail. The body  40  defines an internal chamber  42 . The body  40  includes first or upper end  44 , a second or lower end  46  and a cylindrical internal wall  48 . The upper end  44  of the body  40  includes an outwardly tapering portion  50  and an upper cylindrical flange  52 , provided with internal threads  54 . The lower end  46  of the body  40  is provided with an annular overhanging lip  56  defining a series of openings  58  and a depending flange  60  extending downward from the annular lip  56  surrounding the opening  58 . 
     Referring to FIGS. 3-4 and  5 , the coupler  70  includes a disk-shaped base  72  which partially defines a central aperture  74 . A coupler  70  includes a pair of depending and concentric annular lips. The first or inner annular lip  76  likewise partially defines the aperture  74 . The second or outer annular lip  78  is spaced from and surrounds the inner annular lip  76 . 
     The inner annular lip  76  defines an overhanging flange  82  and a depending ridge  84 . The inner lip  76  and the overhanging flange  82  cooperate to define a handle seat. The overhanging flange  82  and depending ridge  84  cooperate to define an inner O-ring seat. The first annular lip  76  and the depending ridge  84  likewise form an outer annular spring groove  88 . The inner annular lip  76 , the base  72  and outer annular lip  78  cooperate to define a first annular channel  90 . Which defines a seat which receives an O-ring  91 . The outer annular lip  78  is provided with internal threads  96 . 
     Alternatively, the flange  52  of the body  40  could be provided with external threads and the lip  76  of the coupler  70  with internal threads. This arrangement would facilitate tooling to form the body. 
     The shaft  110  has a first or upper end  112  and a second or lower end  114 . The upper end is provided with external threads  116 . The lower end  114  of the shaft  110  advantageously includes a radially outward extending portion  118 . The shaft includes an internal wall  120  which defines an internal flow channel  122  having a lower inlet end  124  and an upper outlet end  126 . 
     Referring to FIGS. 6 and 6 a , the piston  130  is mounted around the shaft  110 . The piston includes a body  132  having a top  134  and bottom  136 . The piston defines an inner annular surface  138 , which defines an internal channel  140 . The inner annular surface  138  desirably defines a tapering portion  142 . The piston  130  desirably additionally includes a series of radially extending locating ribs which define a series of upper surfaces  144 . These surfaces  144  cooperate to define an outer annular groove  146  for receiving the biasing member  180 . 
     Referring to FIGS. 5 and 6, the piston  130  divides the internal chamber  42  of the body  40  of the attachment into a first or upper portion  150  and a second or lower portion  152 . Mounted within the opening  58  defined by the overhanging lip  56  of the lower end  46  of the body  40  is the inlet or check valve  160 . The check valve  160  permits the flow of fluid into the internal chamber  42  of the body  40  of the attachment, while preventing the flow of fluid out of the internal chamber  42 . Advantageously, the check valve  160  is provided with an upper nipple  162  which mates with the inlet  124  of the shaft. The lower nipple  166  secures the check valve  160  in place. Likewise, the check valve is provided with a lower nipple  166  depending from the overhanging lip  56  of the lower end  46  of the body  40 . The check valve defines a central flow channel  168 . 
     The biasing member  180  has a first or upper end  182  which is seated in the outer annular spring groove  88  of the coupler and a second end  184  which is seated in the annular groove  146  in the top of  134  of the piston  130 . 
     Referring to FIG. 5, the handle  190  is mounted on the upper end  112  of the shaft  110 . The handle includes a vertical stem  192  and a grip or horizontal portion  194 . The horizontal portion is desirably integrally formed with an upper end  196  of the stem  192  and the lower end  198  of the stem  192  is desirably secured to the upper end  112  of the shaft  110 . The stem desirably defines an internal flow channel  200 . The lower end  198  of the stem  192  desirably defines a larger mouth portion  202  which defines internal threads  204  with the external threads of  116  on the upper end  112  of the shaft  110 . The horizontal portion  194  desirably likewise defines an internal flow channel  206  which communicates with the internal flow channel  200  of the stem  192 , and includes a closed end  208  and an open end  210 . 
     Referring to FIGS. 1 and 1 a - 1   d , the attachment of the tubing  222  to the horizontal portion  194  of the handle  190  will now be described. To ensure a fluid-tight seal, the tubing  222  is locked to a connector or  300  and the adaptor  300  is locked to the horizontal portion  194  of the handle  190 . As seen in FIG. 1 a , the adaptor  300  has a disc-shaped outer section  302 , a cylindrical intermediate section  304  and a smaller diameter cylindrical inner section  306 . A cylindrical wall  307  defines an interior flow channel  309  running the length of the adaptor. The intermediate section  304  includes an enlarged annular stop  308  proximate to the inner section  306 . The inner section  306  includes an annular locking flange  310  which mates with a corresponding annular detent in the horizontal portion  194  of the handle  190 . The inner section  306  further comprises a first sealing ring  312  and a second sealing ring  314  spaced inward from the locking flange and sized to form a fluid-tight seal with the wall defining the internal flow channel  206  of the horizontal portion  194  of the handle  190 . The outer section  302  defines a pocket  316  for receiving a locking ring  318 . As best seen in FIG. 1 e , the locking ring  318  defines a plurality of gripping edges or corners  320 , which are adapted to apply pressure against the outer surface of the tubing  222  and prevent it from being inadvertently pulled from the adaptor  300 . 
     FIG. 11 shows an integrally formed one-piece handle and shaft or plunger  424  which may be used in place of the two-piece handle and shaft described above. The integral plunger  424  would eliminate a possible leak point between the handle and shaft. The plunger  424  includes a shaft portion  426  and a handle portion  428  which are joined at a stop collar  430 . The handle portion  428  includes as vertical stem section  432  and a horizontal grip section  434 . The shaft portion  426  of the plunger  424  includes an internal wall  436 , which mates with a plug  438 . The plug includes an insert portion  440  which is received within the shaft portion  426  and an exterior portion  442  which protrudes outside of the shaft portion  426 . The insert portion  440  includes a radially extending annular ridge  444  which mates with an annular recess  446  in the internal wall  436  of the shaft portion  426 . 
     Alternatively, it may be desirable to provide external threads on the distal end of the shaft portion  426  and an alternative plug with internal threads to mate therewith would eliminate the need for the annular recess  446  in the inner surface of the shaft which could facilitate the molding of the plunger  424 . 
     Illustrated in FIG. 11 a  is an alternative adaptor or connector  850  secured within the handle portion  428  of the one piece plunger  424 . The connector  850  has a larger diameter head portion and a smaller diameter body portion. Importantly, the connector  850  avoids the use of a locking ring. The elimination of the locking ring facilitates the quick and easy attachment of the connector  850  to the plunger  424 , while an added O-ring  852  adjacent to the inner end of the head portion prevents leaks. 
     FIG. 11 a  also illustrates an alternative plug  860  for blocking the flow channel through the stem section  432  of the handle portion  428 . The plug  860  is similar to the plug  344 , with the exception that the plug is solid and does not incorporate a second sealing flange. The solid plug has greater strength and the elimination of the second sealing flange reduces binding. 
     To ensure proper operation of the assembly  10 , the assembly includes a number of additional sealing members, which will now be described. A first seal or O-ring  252  is mounted at the upper end  44  of the attachment  30  within the inner O-ring seat defined by the first annular lip  76  and overhanging flange  82  out of the coupler  70 . The first O-ring  252  is secured within the seat by means of an annular retaining clip  254  which desirably surrounds the depending ridge  84 . Referring to FIGS. 6 and 6 a , a second seal or O-ring  256  surrounds the second end  114  of the shaft  110  and desirably abuts against the radially outward extending portion  118  of the shaft  110 . To ensure that the piston  130  forms a sealing engagement with the internal wall  48  of the body  40  of the attachment  30 , the piston  130  is desirably provided with a first and a second sealing gasket or cup seals,  258  and  260 , respectively. Specifically, the body  132  of the piston  130  desirably defines an annular space between the bottom  136  of the piston and the portion of the body  132  which defines the outer annular surface  144  and the gaskets  258  and  260  are resiliently secured to the body  132  filling the space. The gaskets  258  and  260  ensure that the piston  130  forms a fluid-tight seal with the internal wall  48  of the body  40  and prevent flow between the gaskets  258  and the external wall of the piston body. 
     FIG. 8 shows an alternative piston design which may be desirable to avoid the need for relatively expensive cup seals. Specifically, the piston  400  defines an outer generally cylindrical surface  402  which is bisected by an annular triangular groove  404  which receives a sealing member or O-ring  406 . The O-ring  406  ensures a fluid-tight seal between the piston  400  and the internal wall of the body of the attachment. 
     Referring now to FIGS. 9,  9 A and  9 B, there is shown a second alternative piston  450  which may be desirable to avoid the need for separate seals. The piston  450  defines an outer cylindrical surface  452 , an upper annular lip  454 , and a lower annular lip  456 . Advantageously, use of this piston  450  avoids the need for a separate O-ring seal and reduces the stacking of tolerances. Specifically, in designs using separate O-rings, it is required to maintain the tolerance of the inner wall of the body, the external cylindrical wall of the piston, and the O-ring itself. By eliminating the use of the separate O-rings, it is only necessary to maintain the tolerances of the piston  450  and the inner wall of the body  40 . 
     FIG. 10 shows a third alternative piston design  470 . The piston  470  defines an outer cylindrical surface  472 , an intermediate recess  474 , an upper annular foot  476  and a lower annular foot  478 . Other than the intermediate recess, the piston  470  is similar to the piston  450 . The intermediate recess  474  has the advantage of providing a piston with uniform wall thickness and a piston which requires less material to manufacture. 
     The assembly  10  is desirably provided with a mechanism for locking the handle in a fully retracted position. Referring to FIGS. 1,  3  and  4 , the coupler  70  desirably defines a pair of parallel L-shaped overhanging flanges  270 . The flanges  270  are sized and shaped to permit a locking plate  272  to slide snugly between the flanges  270 . The locking plate includes a first end  274  and a second end  276 . The first end  274  defines a first grip portion  278  and the second end  276  defines a second grip portion  280 . Desirably, the locking plate defines a vent passage  282  which cooperates with a corresponding vent opening  322  in the base  72  of the coupler  70 , when the locking plate is in its unlocked position. Surrounding the top of the vent opening  322  is a sealing member  324 , such as an O-ring to prevent leakage of fluid when the locking plate  272  is in its locked position, as shown in FIG. 1 c . 
     The locking plate  272  defines an aperture  284  including a first smaller portion  286  defined by first edge  288  sized and shaped to snugly receive the portion of the stem  192  of the handle  190  above the larger mouth portion  202 . The aperture  284  further includes a larger second portion  290  defined by a second edge  292  which is sized and shaped to permit the free movement of the larger mouth portion  202  of the stem  192  of the handle  190  therethrough. 
     Referring to FIG. 3, the base  72  of the coupler  70  desirably defines a raised dimple  325  positioned to abut the outer edge of the locking plate  272  to keep the locking plate from sliding when the locking plate  272  is in the open position. Advantageously, the locking plate  272  is provided with a mating detent  326  to receive and retain the dimple  325  when the locking plate is in the closed position shown in FIG.  4 . 
     Referring to FIGS. 18-21, a sprayer  500  for use in connection with assembly will now be described in detail. 
     The sprayer  500  includes a generally cylindrical grip  502 , a narrow nose  504  having a generally plus-shaped cross-section and a spray end  506 . Advantageously, a separate spray piece  508  is provided to permit the spray to be adjusted. 
     The sprayer  500  includes an actuator  510  surrounded by a thumb rest  512  (FIG.  19 ). As best seen in FIG. 21, the grip  502  of the sprayer  500  defines a pair of openings  514 . Each opening is defined by a first generally c-shaped wall defining a larger portion of the opening  518  and a second c-shaped wall  520  defining a smaller portion of the opening  522 . 
     The grip  502  also defines a slot  530  for receiving the connector  850 . The connector  532  is connected by a length of tubing  534  to a valve housing  550 . Advantageously, the tubing  534  is wrapped around a valve housing to prevent any pulling on the tubing  534  from disconnecting the link tubing  534  from the valve housing  550 . 
     As best seen in FIGS. 22-23, the valve housing  550  includes an inlet portion  552  including a first wall  554  which defines an inlet channel  556  and a first port  558 . The valve body also includes an outlet portion  562  which includes a second wall  564  which defines an outlet channel  566  which in turn defines a second port  568 . The inlet portion  552  and the outlet portion  562  are connected by an intermediate portion  572 . The intermediate portion  572  includes a third wall  574  which defines a connecting chamber  576 . The third wall further defines a bottom vent port  578 . The inlet portion  552  defines a pocket  582  for receiving a locking ring  584  to secure the tubing  534  within the inlet channel  556 . 
     The actuator  510  is connected to and is integrally formed with the valve. The valve has a valve shaft  588  including a narrow portion  590 . A first recess  592  is positioned above the narrow portion  590  and receives a first O-ring  594 . A second recess  596  is positioned below the narrow portion  590  and receives a second O-ring  598 . A third recess  600  is positioned below the second recess and receives a third O-ring  602 . 
     FIG. 22 shows the valve in a off position, with flow entering the inlet portion  552  and seeking to flow into the intermediate portion  572  through the first port  558 . Flow, however, is blocked by the second O-ring  598  positioned just above the first port  558  and the third O-ring  602  positioned just below the first port  558 . 
     FIG. 23 illustrates the valve in a flow through position where the valve shaft  588  has been depressed so that both the second O-ring and the third O-ring are positioned below the first port  558 . As such, flow is able to pass through the first port  558  around the narrow portion  590  of the valve shaft  588  through the second port  568  and through the outlet portion  562  of the valve housing  550 . Advantageously, the lower vent port  578  prevents fluids from being trapped in the valve body, which otherwise might prevent operation of the valve. 
     FIG. 24 illustrates a first alternative valve assembly including a valve housing  610  defining an inlet portion  612  having a first wall  614  which defines an inlet channel  616  and a first port  618 . The valve housing  610  further includes an outlet portion  622  including a second wall  624  which defines an outlet channel  626  and a second port  628 . The valve housing likewise includes an intermediate portion  632  between the inlet portion  612  and the outlet portion  622 . The intermediate portion  632  defines a third wall  634  which defines a connecting chamber  636  and a closed end  640 . The actuator includes a valve shaft  644  having a narrow portion  646  and a first recess  648  for receiving a first O-ring  650 . The valve shaft  644  likewise defines a second recess  652  for receiving a second O-ring  654 . FIG. 24 illustrates the valve in a closed position. Flow is prevented from flowing through the assembly by the third wall  634  of the connecting chamber and the second O-ring  654 . 
     FIGS. 25 and 25A illustrate the valve assembly in an open position, with the valve depressed. In this position, the valve shaft  644  is depressed so that a portion of the narrow portion  646  of the shaft is aligned with the first port  618  so that flow through the first port  618  around a narrow portion  646  of the valve shaft  644  and through the second port  628  is permitted. Importantly, fluid is not trapped within the closed end  640  of the valve body  610  because the first port  618  is sized, shaped, and positioned such that in the on position, fluid is permitted to flow not only through the inlet portion  612  above the second O-ring  654  but also from the closed end  640  of the valve body  610  beneath the second O-ring and back into the inlet portion  612  of the valve body. This arrangement prevents fluid from dripping out of the valve body, while at the same time preventing fluid trapped within the closed end of the valve body  610  from preventing proper operation of the valve. 
     FIG. 26 shows a second alternative valve assembly including an alternative valve housing  660 . The valve housing  660  includes an inlet portion  662  having a first wall  664  which defines an inlet channel  666  and a first port  668 . The valve housing  660  also defines an outlet portion  672  having a second wall  674  which defines an outlet channel  676  and a second port  678 . Positioned between the inlet portion  662  and the outlet portion  672 , is an intermediate portion  682 . The intermediate portion  682  has a third wall  684  which includes an upper portion  686  and a lower portion  688 . The third wall defines a connecting chamber  690 . 
     The valve shaft  700  includes an outer section  702  connected to the actuator, a narrow intersection  704  and an intermediate section  706 . The outer section  702  has a larger diameter than the intermediate section  706  and the intermediate section  706  has a larger diameter than the inner section  704 . A first sealing flange  710  is positioned between the outer section  702  and the intermediate section  706  of the valve shaft. A second sealing flange  708  is positioned at the distal end of the inner section  704  opposites the outer section  702 . Advantageously the first sealing flange  710  cooperates with the upper portion  686  of the third wall  684  to prevent fluid from passing out of the valve body  660 . Similarly, the second sealing flange  708  cooperates with the lower portion  688  of the third wall  684  to prevent fluid from passing therebetween. FIG. 26 illustrates the second alternative embodiment of the valve in a closed position. In this position, flow is permitted through the inlet portion  662  and into the connecting chamber  690 , but is prevented from flowing through the second port  678  by the second sealing flange  710 . FIG. 27 illustrates the second alternative valve in an open position. In this position, the actuator shaft  700  is depressed and fluid flows through the inlet channel  666  through the first port  668  around the inner section  704  of the actuator shaft  700 , through the second port  678  and through the outlet channel  676 . 
     The operation of the apparatus will now be described. 
     Referring to FIGS. 1 and 1 d , during storage or shipment, the shaft  110  is secured in its fully retracted position, with the shoulder or mouth portion  202  of the handle  190  being retained in position by the locking plate  272 . During shipment, the tubing  222  connecting the spray nozzle  222  to the handle  190  may be secured in a hollow portion of the spray nozzle  220 . The nozzle  220  is desirably provided with a pair of openings  340  for receiving and retaining a pair of mating studs  342  projecting from the side of the container  20 . 
     FIG. 15 shows an alternative assembly  720  including a container  730 , a pump attachment  740  and a sprayer  750 . The container includes a pair of studs  752  positioned on the back wall of the container. Each of studs is identically shaped. The assembly  720  is generally the same as the assembly  10 , with the exception of the shape of the studs. As shown in FIG. 15, the sprayer  750  is mounted on the container  730  by means of cooperation of the studs  752  and the wall of the sprayer defining the bayonet openings. As best seen in FIGS. 15 and 17, the studs  752  include a stem portion  754  and a taller and wider head portion  756 . The head portion defines a first overhang portion  758  which extends beyond the edge of the stem portion  754  a distance D1. Similarly, the head portion  756  defines a second overhang  760  extending beyond the opposite side of the stem portion  754  a distance D2. Advantageously, the distances D1 and D2 are at least 0.015 inches, and are preferably 0.025 inches. 
     This mounting arrangement is superior to the mounting arrangements of prior art in that it facilitates the manufacture of a simple, inexpensive and secure mounting means for the sprayer. 
     FIGS. 12-14 illustrate a prior art assembly  770  including a container  772 , connected by tubing  774  to a sprayer  776 . The sprayer includes a nozzle  778 , a trigger  780  and a handle  782 . The container  772  defines a recess  784  and a sidewall for receiving the nozzle  778 , trigger  780  and handle  782  of the sprayer  776 . The container  772  defines a pair of generally rectangular raised protrusions  786  which extend outward from the side wall of the container  772 . As best seen in FIG. 14, the protrusion  786  defines side grooves  788 . 
     The sprayer  776  defines a pair of I-shaped openings  800  corresponding in location to the location of the protrusions  786  on the container  772 . Each I-shaped opening  800  defines a pair of opposing spring tabs  802 . As disclosed in U.S. Pat. No. 5,469,993, to Monsanto, the opposing spring tabs  802  are to be resiliently received by the side grooves  788  to secure the sprayer  776  to the container  772  during storage. The &#39; 993  patent discloses that the container is preferably made by blow molding. As shown in FIG. 14, the protrusions  786  define a first overhang  804  extending beyond the inner portion of the recess a distance D3 and a second overhang  806  extending beyond the outer surface of the recess a distance D4. Unfortunately, this design is undesirable in that it is very difficult to manufacture the opposing spring tabs  802  of the sprayer  750  and the protrusions  786  of the container  730  to sufficient tolerances that the sprayer can be securely attached to the container  730  in this manner. In an effort to avoid having the sprayer detach from the container during shipment, sprayers of this design have been glued to containers or tied to the containers during shipping. Neither of these approaches was desirable from an aesthetic, cost or functional basis. 
     Importantly, however, the assembly  720  of the present invention overcomes these drawbacks. The positioning of the studs  752  along the seam line  812  of the container  730  permits the studs  752  to be manufactured with a significantly larger first overhand distance D1 and second overhang distance D2. As a result, the studs, in cooperation with the bayonet openings of the sprayer  750 , can secure the sprayer  750  securely to the container  730  during shipment. 
     The reason that this larger overhang is possible is best understood in connection with FIG. 17 which schematically illustrates the method of manufacturing a container  730 . A first mold half  814  and a second mold half  816  are positioned on either side of a break plane  818 . Plastic is then blown into the mold to form the container  730 . Because the mold halves separate in a direction perpendicular to the break plane, the first mold half  814  can define a first flange  820  which extends beyond the side of the stem  754  a distance approximately equal to D1. Similarly, the second mold half  816  can form a second flange  822  which extends beyond a recess a distance approximately equal to D2. 
     As shown in FIG. 1 d , during shipment the inlet to the internal flow channel  204  of the stem  192  of the handle is blocked by a plug  344  mounted within the internal flow channel  206  of the horizontal portion  194  of the handle. The plug  344  includes first and second sealing flanges  346  and  348  which prevent the flow of fluid between them and the wall forming the internal flow channel  206 . The end of the plug  344  facing the open end  210  of the handle  194  defines a cutout  350 . 
     Importantly, the mating of the upper nipple  162  of the check valve  160  with the inlet  124  of the shaft prevents fluid from leaking out the handle during shipment and storage of the assembly  10 , prior to use. On the other hand, the plug  344  provides a fail-safe backup in the event the locking plate  272  is moved to the open position and the handle is raised. 
     When it is desired to use the assembly  10  to dispense fluid  260  from the container  20 , the adaptor  300  on the end of the tubing  222  is inserted into the internal flow channel  206  of the horizontal  194  portion of the handle. This causes the inner section  306  of the adaptor  300  to push the plug away from the outlet of the internal flow channel  206  of the horizontal portion of the handle so that the sealing flanges  346  and  348  are pushed beyond the outlet of the internal flow channel  204  of the stem  204 , as shown in FIG. 1 a . The inner section  306  of the adaptor  300  forms a port with the cutout  350  of the plug  344  through which fluid may flow from the internal flow channel  206  of the horizontal portion  194  of the handle  190  and the interior flow channel  309  of the adaptor  300 . The locking plate  272  is then moved from the locked position shown in FIG. 4 to the unlocked position shown in FIG.  3 . The grip portion  194  of the handle can then be lifted upward as illustrated in FIG.  2 . This causes the second O-ring  256  to press against the tapering portion  142  of the body  132  of the piston  130  creating a fluid-tight seal. This also causes the fluid  260  to be drawn through the check valve  160  into the lower portion  152  of the chamber  42 . It is not necessary to draw the handle completely upward. On the other hand, to maximize the amount of fluid that may be dispensed without repressurizing the container, the handle may be drawn to its fully pressurized position as illustrated in FIG.  5 . In this position, the spring  180  is fully compressed between the coupler  70  and the piston  130 . The handle  190  is then released, allowing the spring  180  to force the piston  130  downward against the fluid  260  in the lower portion  152  of the chamber  42 . As the check valve  160  prevents fluid from flowing out of the chamber  42  fluid is forced upward through the inlet end  124  of the internal flow channel  122  defined by the shaft  110 . This fluid flows through the internal flow channel  200  of the stem  192  and the internal flow channel  206  of the grip portion  194  of the handle  190 . The fluid is likewise forced through the tubing  222  to the spray nozzle  220 . Fluid is dispensed from the spray nozzle  220  by depressing the actuator  240  operating the release valve (not shown) for the nozzle  220 . 
     Significantly, the assembly  10  of the present invention permits the quick and easy release of pressure within the pump attachment  30 . Specifically, as shown in FIGS. 6 and 6 a , the handle  190  can be forced rapidly downward so as to move the second end  114  of the shaft  110  downward relative the piston  130 . This causes the second O-ring mounted on the radially outward extending portion  118  of the lower end  114  of the shaft  110  to move downward away from the tapering portion  142  of the inner annular surface  138 . This releases a seal between the shaft  110  and the piston  130  and permits fluid  260  to flow through the channel  140  between the inner annular surface  138  of the piston  130  and the outer surface of the shaft  110 . This fluid  260  is eventually drained from the upper portion  150  of the body  40  of the attachment through a pair of outlet openings  346 . 
     Importantly, the release of pressure from the body  40  of the attachment  30  prevents fluid from inadvertently being released from the assembly  10  during operation, transport and storage of the apparatus. Further, as illustrated in FIG. 7, this release of pressure permits the shaft  110  to return to its fully retracted position so that the mouth portion  202  of the handle can be received within the aperture  74  in the coupler  70  against the coupler  70  and locked in place against the handle seat by the locking plate of the coupler. 
     Those of skill in the art will recognize that this invention may be embodied in several forms, without departing from the spirit of the invention, and the foregoing description is therefore intended to be illustrative and not restrictive.