Foam/spray nozzle assembly for trigger sprayer

Abstract: A manually actuated liquid sprayer (20) has a ported element (21) selectively movable between a retracted position and an extended position at which the element (21) lies in the path of the spray plume for mitigating the spray. The element (21) has a cylinder (44) with a smooth inner wall (45) defining a turbulence chamber (46) coaxial with the discharge orifice (25) of the nozzle cap (24) to which the element (21) is mounted. A transversely extending perforate wall (47) is located in the cylinder (44), and has an open port (38) of a size greater than that of the discharge orifice (25) and being coaxial therewith. The element (21) is movable relative to the nozzle cap (24) between the retracted position at which the liquid spray passes through the open port (38) without influence from any portion thereof, and the extended position at which the liquid spray impacts against the smooth inner wall (45) to mix with air in the chamber (46) and passes through the perforate wall (47) to create foam ejected from the element (21).

Description: BACKGROUND OF THE INVENTION This invention relates to a manually actuated liquid sprayer comprising a nozzle containing a discharge orifice for discharge under pressure of a divergent plume of liquid spray in a downstream direction, and an element selectively movable between a retracted position and an extended position at which the element lies in the path of the spray plume for mitigating the spray, the element having a cylinder, a transversely extending perforate wall and said perforate wall comprising first and second sets of ribs, said ribs being mutually spaced apart and parallel in each said set to define uniformly sized openings therebetween, said wall being located in said cylinder, said wall having an open port of a size greater than that of the discharge orifice and being coaxial therewith, the element being mounted on the nozzle for axial movement relative thereto between said retracted position at which the liquid spray passes through the open port without influence from any portion thereof. U.S. Patent No. 4,779,803 discloses a manually actuated liquid sprayer having an element mounted on its nozzle for selective movement between retracted and extended positions relative to the front wall of the nozzle. The element has an open port coaxial with the discharge orifice of a size greater than that of the orifice, the element comprising a mitigating element for mitigating the divergent spray issuing from the orifice. The open port is sized relative to that of the spray plume such that the mitigating element has no effect on the liquid spray as it passes through the open port. The element includes a ported mesh screen through which the spray emerges for creating foam in the extended position of the element. U.S. Patent 5,397,060 discloses a foam-spray-off trigger sprayer having an axially moveable perforated wall mounted for axial movement inside a front barrel of a trigger sprayer nozzle, whereby the moveable perforated wall can be moved between (a) a stream position, where a central opening in the perforated wall is positioned closely adjacent an outlet orifice in a back wall of a foam generating chamber defined within the front barrel to (b) a foam generating position where the perforated wall is positioned forwardly of the outward orifice where droplets of liquid impinge upon the perforated wall, are deflected and mix with air to form foam. According to the prior art, foaming is effected in the extended position as the divergent spray passes through a perforated plate or wall for producing a foam. An unacceptable amount of airborne droplets is introduced into the atmosphere with such foamers, giving rise to vapors produced which may cause burning of the eyes, nose and mouth especially when discharging household cleaners. Also, the foam is of diminished quality which dribbles when applied to the target. SUMMARY OF THE INVENTION It is the objective of the present invention to provide a manually actuated liquid sprayer comprising a nozzle containing a discharge orifice for discharge under pressure of a divergent plume of liquid spray in a downstream direction, and an element selectively movable between a retracted position and an extended position, the element having a cylinder with a smooth inner wall defining a turbulence chamber coaxial with the discharge orifice, a transversely extending perforate wall located in said cylinder, said perforate wall having an open port of a size greater than that of the discharge orifice and being coaxial therewith, said perforate wall comprising first and second sets of ribs, each said set of ribs having ribs mutually spaced apart to define uniformly sized openings therebetween, the element being mounted on the nozzle for axial movement relative thereto between said retracted position at which the liquid spray passes through the open port without influence from any portion thereof, and said extended position at which the element lies in the path of the spray plume for migating the spray. According to the invention, the object is achieved by first and second sets of ribs respectively lying in first and second parallel planes and said ribs of both said sets having flat surfaces facing upstream and lying perpendicular to a central axis of said cylinder for generating foam as the foam impacts against said flat surface, said ribs of said first set being contiguous to said ribs of said second set, or said first and second set of ribs extending in a common direction and said ribs of said first set being equally spaced apart and offset relative to said ribs of said second set a distance substantially equal to one half the spacing of said ribs of said first set thereby defining the said openings, such as in said extended position of the element the liquid spray impacts against said smooth inner wall to mix with air in the chamber and passes through said perforate wall which enhances the creation of foam ejected from a downstream end of said cylinder. The perforate wall may otherwise be in the form of spaced ribs in parallel sets with the ribs extending in a common direction, the ribs of one set being spaced a distance substantially equal to one-half the spacing of the ribs of the other set. The ribs may be trapezoidal in section with the ribs of a downstream set converging forwardly and the ribs of the upstream set diverging forwardly. Other perforate wall structures comprised of ribs in accordance with the aforementioned application can be adapted for the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front plan view of one embodiment of the shiftable element of the nozzle assembly according to the invention; Figure 2 is a sectional view taken substantially along the line 2-2 of Fig. 1; Figure 3 is a vertical sectional view of the Fig. 1 element mounted to the nozzle of a trigger sprayer, in the retracted position; Figure 4 is a view similar to Fig. 3 of the shiftable element shown in its extended position; Figure 5 is an enlarged front view of the Fig. 1 perforate wall of the shiftable element; Figures 6 and 7 are views similar to Fig. 5 of other embodiments of the perforate wall; Figure 8 is a view taken substantially along the line 8-8 of Fig. 7; Figure 9 is a front view of another embodiment of the perforate wall of the shiftable element; and Figure 10 is a view taken substantially along the line 10-10 of Fig. 9. DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, a trigger actuated pump sprayer generally designated 20 is shown in Figs. 3 and 4 having a ported movable element 21 generally shown mounted thereon. The pump sprayer is of known construction, such as that disclosed in the aforementioned related application, in which its pump body 22 defines a discharge passage 23. A rotatable nozzle cap 24 having a central discharge orifice 25 is snapfitted about discharge end 26 of the pump body as at 27. The cap has an internal sleeve 28 in engagement with a probe cap 29 carrying an annular discharge flap valve 31. The probe cap is fixed to the end of a probe 32, and has a swirl chamber 33 formed at its outer end. Longitudinal grooves 34 and 35 on the probe cap and sleeve 28 are aligned upon relative rotation of the nozzle cap for admitting liquid product via the discharge valve through tangential channels 36 into the swirl chamber upon pumping action of the sprayer for inducing a swirl through the liquid product to issue through the discharge orifice as a divergent spray. Pumping action is effected upon manual actuation of trigger lever 37 hinged to the pump body in a known manner. The pump sprayer may have any other type swirl or spin chamber to internally effect a vortex of the liquid product, causing the product to discharge from orifice 25 as a spray plume typically in the form of a diverging spray cone. And, the spray mechanics may be provided as in accordance with U.S. Patent 4,706,888 for producing a spray discharge and for closing the discharge upon rotation of the nozzle cap between spray-off and stream-off positions. Element 21 of the invention is similar to that disclosed in the aforementioned related application except that the element has an open port 38 therein coaxial with the discharge orifice, and may be telescopically mounted on the nozzle cap for movement between the retracted position of Fig. 3 and the extended position of Fig. 4. A plurality of support legs 39 on element 21 project into a like plurality of elongated axial openings (not shown) located in the nozzle cap and opening into its outer wall 41. Projections 42 formed on the legs may be engageable with stops provided in the nozzle cap grooves for limiting the outward extent of element 21 to its Fig. 4 position, similarly as structured in U.S. Patent 4,779,803. Element 21 may extend outwardly as at 43 from one or more side walls of the nozzle cap so as to provide gripping means for facilitating manual sliding movement of the element. Element 21, in its Fig. 4 extended position, functions as a foamer cap as in the manner disclosed in the aforementioned related application. The spaces between legs 39 form air aspiration openings, and the element has an inner cylinder 44 coaxial with port 38 and discharge orifice 25. The cylinder has a smooth inner wall 45, the cylinder defining a turbulence chamber 46, such that during pumping, the divergent spray impacts against inner wall 45 of the turbulence chamber, thereby creating and concentrating a foam as the spray particles mix with air in the turbulence chamber as aspirated through the openings formed between spaced legs 39. In accordance with one embodiment of the invention, a foam enhancer or spray particle mitigator is provided in the form of a screen or grate 47 shown in Figs. 1 to 6 in the form of a perforate wall 47 which includes first and second sets of ribs 48 and 49 respectively lying in parallel planes and formed integrally at opposite ends with inner wall 45 of cylinder 44. Ribs 48 and 49 are contiguous, the ribs of each set being respectively parallel and extending in mutually perpendicular directions forming substantially rectangular openings 51 between the ribs of the two sets. And, similarly as in the aforementioned related application, ribs 48 and 49 may each be rectangular in cross-section with the longer sides thereof extending along the downstream direction of flow of the liquid product through the discharge orifice. The disposition of the longer sides of the ribs along the flowpath tends to enhance the foaming formation as the foam bubbles concentrated in turbulence chamber 46 first impact the confronting flat surfaces of ribs 49, glide along the opposing sides of ribs 49 which accelerate the turbulent flow as the foam bubbles then impact against the confronting flat surfaces of ribs 48 and glide along the opposing sides thereof which further accelerate the turbulent flow. The foam further admixes with the air in chamber 46 to enhance the generation of foam which passes through screen 47 to the target. In a retracted position of element 21 shown in Fig. 3, the element bears against front wall 41 of the nozzle cap, and port 38 is sized relative to the divergent spray plume generated as to permit the spray to pass through open port 38 without influence from any portion thereof. Port 38 may be defined by a ring 52 molded integrally with the inner terminal ends of ribs 48 and 49. However, ring 52 has no function other than to simply interconnect the inner terminal ends of ribs 48 and 49, since ring 52 may be entirely eliminated as shown in Fig. 6, whereupon inner terminal ends 53 and 54 of the ribs themselves define open port 38. The foam enhancer of the invention in combination with cylinder 41 of element 21 may be in the form of a grate or grid 55 in the form of a perforate wall shown in Figs. 7, 8 integrally molded in cylinder 44 at an axial location similar to that of screen 47, such that in the Figure 4 extended position of element 21, the divergent spray impacts against inner wall 45 to create and concentrate foam prior to passing through the openings between the screen or grate ribs to enhance the foaming formation. The foam bubbles which may be intermixed with spray particles likewise impact against smooth inner wall 45 located downstream of screen 47 or grid 55, as shown, to further enhance the foaming formation. Of course, the screen or grate can be located closer to the downstream end of inner wall 45 such that substantially all the foam bubbles and/or spray particles emerge directly from the downstream side of the screen or grate as a foam without further impacting against wall 45 downstream of the screen or grid. Grate 55 comprises a plurality of ribs 56, 57, each extending in a common direction, such as horizontal. Ribs 56 are parallel to one another and are mutually spaced apart to define uniform openings 58 of a first set of ribs. Similarly, ribs 57 are parallel to one another and are mutually spaced apart to define uniform openings 59 of a second set. The first and second sets of ribs are relatively offset, such as in a vertical direction as shown, a distance substantially equal to one-half spacing 58 or 59, such that the net spacing of ribs between the two sets defines openings 61 shown in Fig. 7. With this arrangement, grater larger spacings 58 and 59 of the ribs in the respective sets simplify the tooling and molding operations and yield an effective spacing 61 which is substantially one-half either spacing 58 or 59. The two sets of ribs lie in spaced apart parallel planes, the upstream surfaces of the ribs of both sets being flat similar to that of the ribs of screen 47. Ribs 56, 57 may be trapezoidal in section, with the opposing sidewalls of the ribs of the first set converging in the downstream direction, and the opposing sidewalls of the ribs of the second set diverging in the downstream direction. Of course, ribs 56, 57 of both sets can be so oriented that their opposing sidewalls either converge in the downstream direction or both diverge in the downstream direction. The flat surfaces of the ribs confronting the turbulence chamber provide impact surfaces for the foam bubbles created in the chamber, enhance the foaming formation, and facilitate virtually unimpeded discharge of foam through the grid outwardly of the end of element 21. The inner terminal ends of ribs 56 and 57 may together form open port 38 or may be interconnected by a ring such as 52, not shown, to form the open port. Another embodiment of the foam enhancer as part of element 21 employed in combination with turbulence cylinder 46 is shown in Figs. 9, 10 in the form of a screen 62 similar to that of grate 55 in that it includes first and second sets of relatively offset ribs 56, 57 lying in spaced planes with the ribs being spaced apart as at 58 and 59. In addition, a third set of mutually spaced apart ribs 63 extend in a direction perpendicular to the common direction along which ribs 56, 57 extend. Ribs 63 are zig-zag shaped and are molded to intersect with horizontal ribs 57 while extending behind or downstream of ribs 56 as shown in Fig. 10. The mutually spaced ribs of the three sets define openings 64, shown in Fig. 9. The back faces of ribs 63 are flat and may be trapezoidal in section with opposing side walls thereof either converging or diverging in the downstream direction. Many modifications and variations of the present invention are made possible in the light of the above teachings. It is therefore to be understood that within the scope of the appending claims, the invention may be practiced otherwise than as specifically described.

Claims: A manually actuated liquid sprayer comprising a nozzle containing a discharge orifice for discharge under pressure of a divergent plume of liquid spray in a downstream direction, and an element (21) selectively movable between a retracted position and an extended position, the element (21) having a cylinder (44) with a smooth inner wall (45) defining a turbulence chamber (46) coaxial with the discharge orifice (25), a transversely extending perforate wall (47) located in said cylinder, said perforate wall (47) having an open port (38) of a size greater than that of the discharge orifice (25) and being coaxial therewith, said perforate wall (47) comprising first and second sets of ribs (48,49,56,57), each said set of ribs having ribs mutually spaced apart to define uniformly sized openings (51,61) therebetween, the element (21) being mounted on the nozzle for axial movement relative thereto between said retracted position at which the liquid spray passes through the open port (38) without influence from any portion thereof, and said extended position at which the element lies in the path of the spray plume for migating the spray, characterised by first and second sets of ribs (48,49,56,57) respectively lying in first and second parallel planes and said ribs of both said sets (48,49,56,57) having flat surfaces facing upstream and lying perpendicular to a central axis of said cylinder (44) for generating foam as the foam impacts against said flat surface, said ribs (48) of said first set being contiguous to said ribs of said second set (49), or said first and second set of ribs (56,57) extending in a common direction and said ribs of said first set (56) being equally spaced apart and offset relative to said ribs of said second set (57) a distance substantially equal to one half the spacing of said ribs of said first set (56) thereby defining the said openings (61), such as in said extended position of the element the liquid spray impacts against said smooth inner wall (45) to mix with air in the chamber and passes through said perforate wall (47) which enhances the creation of foam ejected from a downstream end of said cylinder (44). The liquid sprayer according to claim 1, wherein said ribs (48) of said first set are contiguous to said ribs (49) of said second set, said ribs being mutually spaced apart in each said set to define uniformly sized openings therebetween, said ribs of both said sets having flat surfaces upstream and lying perpendicular to a central axis of said cylinder for generating foam as the foam impacts against said flat surfaces. The liquid sprayer according to claim 1, wherein the element (21) is mounted for telescoping sliding movement relative to the nozzle (24). The liquid sprayer according to claim 2, wherein said ribs of said first and second sets (48,49,56,57) are rectangular in cross-section, the longer sides of said ribs cross-section extending in said downstream direction. The liquid sprayer according to claim 1, wherein said element (21) further comprises a third set of spaced ribs (63) interconnecting with and extending in a direction perpendicular to said ribs of said first and second sets (48,49,56,57). The liquid sprayer according to claim 1, wherein said first set of ribs (48,56) is located downstream of said second set of ribs (49,57), opposing sidewalls of said ribs of said first set converging in said downstream direction, and opposing sidewalls of said ribs of said second set diverging in said downstream direction.

Inventors: DOBBS DOUGLAS B, SPATHIAS ADONIS, DOBBS, DOUGLAS B., SPATHIAS, ADONIS
Applicants: CALMAR INC, CALMAR INC.
Application year: 1996
Main classification: B05B11
IPC codes: B05B11, B05B7, B05B1, B65D83, B05B3, A45D19