IE56874B1 - Liquid dispensing pump - Google Patents

Description

This invention relates generally to liquid dispensing pumps of the form disclosed in U6SO patent 4,046,292, which includes: a pump body defining a pressure accumulation chamber having an axially directed inlet port for communication with a source of flowable product to be dispensed, and an outlet port at the periphery of the said chamber; a unitary element including an inlet check valve controlling tho said inlet port and further^including an outlet valve disposed for axial movement in said chamber from a closed position in which it blocks communication between said ports to an open position in which i« Agfcah? jwheri communication between said ports; a pump cylinder defining a pump chamber coaxial with the said pressure accumulation chamber and in open communication therewith; a pump piston reciprocable in said cylinder independently of the movement of the said outlet valve; resilient raeans normally urging the said outlet valve toward its closed position; and means for manually reciprocating said piston.

The present invention aims at the provision of a modified form unitary element which is of simple conά structiohe being sisapl® to manufacture and to assemble with this pump and which renders the pump oasy to operate whilst effecting a dripless discharge. t.

Tho invention is mainly characterized in that the said unitary element comprise# e thimble-shaped element having ¢1% its inner end 43 transverse end w©l 1 including & central portion constituting the said inlet valve, the said vail being formed with a plurality of elongate openings establishing the open communication between the said chambers, and defining therebetween flexible straps which facilitate relative axial shifting of the said inlet and outlet valves during a pumping operationc Some pumps in accordance with the invention will 10 now be described in detail, by way of example, with reference to the accompanying drawings, in which:Figure 1 is a vertical sectional view of a dispensing pump according to one embodiment of the invention; Figures IA and ID are sectional views similar to Figure 1 showing details of quick opening and slow open<> ing discharge valves, respectivelyj Figure 2 is a perspective view of the thimbleshaped member according to Figure 1; Figures 3, and 5 are sectional views, similar 20 to Figure 1, of other embodiments according to the invention, with portions only of the pump being shown; and Figure 6 is a vertical sectional view of yet another dispensing pump according to the invention.

Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, a liquid dispensing pump in the form of a trigger operated sprayer Is, according to one embodiment of the invention, generally designated 10 in Figure 1 and includes a pump body li defining an inlet passage 12 and on outlet passage 13° A conventional dip tube 1¾ is received within the Inlet passage and extends into a container (not shown) of product to be dispensed in a manner well known in the art, a container cap 15, having Internal threads or other container securement engages an annular Γΐρ ϊό of a circular section of the pump body for mounting th® sprayer on to the neck of tlie container, and if desired a seal ring 17 maY he disposed between the lower end of the pump body and the upper end of the container neck.

The pump body further includes a pump cylinder iQ having a conical end wall 19 containing an Inlet port 21 in which the inl£t passage terminates» The cylinder axi® lies between and extends at an angle to inlet and outlet papsagea 12 and 11. The outlet passage 13 extends from ' β an outlet port 22, located in the wall of cylinder lfl, through a nozzle plujs 20 fitted within the pump body, and terminates In a discharge orifice located in a nozzle cap 23 in engagement with the plug· Also, the pump body is provided with an integral shroud 2^, which may otherwise be made separately and assembled in place and having a contoured wall 25 shaped to fit against the hand when the trigger sprayer ia grasped by the operator» A unitary, thimble-shaped, valving element 26, shown in more detail in Figure 2, ie disposed within cylinder l8Q©nd has at one end thereof o conical transverse end well 27 substantially corresponding in shape to end wall 19· Wall 27 includes a plurality of flexible and extendably-shaped straps 28 which extend from adjacent the apex of the conical end wall to the base and are defined by openings 29 which may be of maze-like conf iguration.

Thus, the tip of wall 27 is capable of axially shifting relative to the remainder of element 26, and vice versa· Instead of openings 29 of the configuration shown, Sshaped, or the like, openings may be provided to facilitate such relative axial shifting movements, without departing from the invention.

The central portion of wall 27 constitutes an inlet check valve 31 for controlling inlet port 21, and 0 straps 28 are neutral from a pressure standpoint. A pressure accumulation chamber 32, shown in detail in Figure Ia, ia defined between th® innsar end of element 26 a ίο an A ring 33 extends from wall 19 toward element 26, and an annular flange 3^ on element 26 adjacent wall 27 constitute® a discharge or outlet valve which seats against ring 33 in e discharge closing position, the flange defining an annular groove 35 with the body of element 26 so as to effectively form an extension of accumulation chamber 32° An annular flexible lip seal 38 on element 26 is located adjacent the free end thereof, although may lie further inwardly toward flange 3¾ if desired, for slideably engaging the inner surface of cylinder l8 in a fluid tight manner» A pump piston 37 in the form of a thimble or cup-shaped element extends into valving element 26 and has a flexible, circular shirt 38 adapted for sliding along the inner surface of the valving element in fluid tight engagement therewith» The piston thus defines a variable volume pump chamber 39 with element 26 and is in open communisation with accumulation chamber 32 via openings 29« Moreover, an annular, flexible shirt or lip seal M on piston 37 surrounds the open end thereof and is slideable along the inner surface of cylinder l8 in a fluid tight manner to define an annular chamber therewith, as shown» Thus, cylinder l8 and element 26 define cylinder means having a boro engaged by lip seal M of the piston and a Counterbore engaged by skirt 38 thereof» A return spring ^2 encircles piston element 37 and extends between flange M and the outer rim of element 26 for normally urging the outlet valv© toward its closing position» Co-operating snap beads on seal 4 3 and the inn^r surfaces of cylinder l8 may be provided for retaining the piston within the pump body.

Sprayer 10 further includes a trigger actuator in the form of a lever 43 having a trunnion 44 to facilitate mounting the lever for pivotal movement about the axis thereof on the pump body. for manual reciprocation of the piston, the lever has a pair of spaced actuator flanges 45 (only one being shown in Figure 1) spaced apart at outer ends 46 thereof a sufficient dis- 0 tance for bearing against outer circular rim 47 of the piston. Alternatively, a rod-like member may extend between the trigger actuator and the end wall of the piston, the rod-like member being integral with either the piston or the trigger member, or may be separate from both, A container vent port 48 is located in the lower region of the vail of cylinder l8, outwardly of the chamber 39 and at least one axially disposed rib 49 is provided in the upper region of the inner surface of cylinder l8ofor flexing seal 4l radially inwardly when in contact therewith during inward movement of the piston, so as to define a passage from atmosphere through the open end of the cylinder l8, past the seal 4l and through vent port 48 to the inside of the container so that dispensed product is replaced with air during the dispensing operation.

As shown, vent port 48 is Inwardly spaced from seal 4l in both non-pumping and pumping positions of the piston. Also, the vent port 48 inherently functions as a sump drain port which establishes communication with the aforementioned annular chamber and the Interior of the container. Thus, with this arrangement, any leakage of product from pump chamber 39 around piston skirt 38 ia purged from tho annular chamber into the container through port 48, any leakage of product from the container through port 48 and outwardly of cylinder 18 ie prevented, ond ony abrasion of piston skirt 3® or lip seal e during pumping or during assembly of th® piston 37, are oil avoided· Xn operation, aft os r the purap chamber la primed 5 with product to bo dispensed, the piston is inwardly reciprocated upon manual actuation of the trigger lover against th® fore® of spring *&2 and the enclosed fluid to thereby increase the pressure within the pump chamber, which pressure mdntains inlet check valve 31 closed during th® compressing strok®0 As th® compression force increases, ther® villi manifestly he a progressively increasing fluid pressure within accumulation chamber 32 until such pressure creates a force on the outer ®nd surfaces of valving member 26 which extend from the pump chamber diameter outwardly to flange 3¾ sufficient to overcome the opposing force of the spring· This will result in movement of flange 3¾ in an axial direction ewtiy from ring 33 to thereby open the discharge passage whereby th^ contents of chamber 39 will he discharged under pressur® through discharge passage 13° Such dis*» charge will continue as long as the pressure within the pump chamber is sufficient to overcome the force of the return spring« However, whon the pressure within the accumulation chamber is reduced, either by reduced octu~ ating force on the piston or through approach of the piston to the end of its pressure stroke, so as to produce insufficient force to overcome the return spring, the spring ®ill act to return the outlet valve immediately to its closed position, thereby affording an abrupt, sharp cutoff of th® discharge to minimise dripping of product from the discharge nosgl®· Since the outlet valve (oe· flange) 3¾ makes tangential contact (Pigwee IA) with ring 33, and th On the other hand, a modification is shown in Figure IB wherein a flange (or outlet valva) 34a is out of contact with ring 33 In the discharge closing position snd is instead in fluid fight engagement with the wall of cylinder 18 for covering the outlet as shown. Thus, the free end of the flange 34© slides along the wall of cylinder l8 af a larger diameter than «, flange 33 until the outlet port 22 is uncovered during the opening movement, do efl to effect a slow opening discharge. The aforedescribed quick opening and slow * opening discharging is likewise Included in the dispensing pump disclosed in UeS„ patent No. 4,402,432· On the succeeding outward stroke of th^ piston under actuation of the return spring, after the closing of the discharge as aforedescribed, the outlet valve will remain seated to prevent hack flow of liquid through the outlet into the accumulation chamber, while the resulting reduced pressure within chambers 3? and 39 will open inlet valve 31 against the resilience of straps 28, thereby enabling a charge of flowable product from the container fo be drawn upwardly through the dip tube snd the inlet port into the intercommunicating accumulation pump chambers.

Outlet valve 34 will remain closed throughout the entire outward stroke of the piston and, at or near the end of such stroke, the inlet valve will be reseated over the inlet port, under the elastic memory action of straps 28 fending to retain the conicity of wall 27, in preparation for the next ensuing compression stroke of the piston.

Reciprocation of the pump piston continues for as * long as is necessary fo dispense the desired amount of product from the container to which the sprayer ie applied, following which th© outlet valve will be automatically 4 seated and sealed by thfi action of its return spring, while the inlet valve is urged immediately to its seated position and retained in such position over the inlet port, by the action of streps 2ft.

Throughout the pumping and dispensing action aa aforedescribed, lip seal 4l will automatically be flexed, upon inward displacement of the piston, by rib 49, with the result that each time a charge of flowable product is delivered through the outlet port to the atmosphere, a vent passage in open communication with tho atmosphere is established through the clearance space between the seal 4l and the inner wall of cylinder l8o Thus, atmospheric air eaay be drawn Into the container through vent port 48 as necessary to replenish dispensed product.

Another embodiment of the liquid dispensing pump or trigger sprayer of the invention is generally indicated iOA in Figure 3 and is constructed in essentially the same manner as pump 10 except for the venting feature. H^re, an annular lip seal 4l forming a vent valve is located sufficiently inwardly from rim 47 of the piston so as to cover vent port 48 at the end of the piston suction stroke. As in Figure 1, snap beads are provided on the piston and the inner wall of cylinder l8 for retaining the piston within the cylinder, except that in Figure 3 & vent passage 51 ie defined outwardly of the lip seal between a skirt 52 on which the seal is formed and th© inn^r surface of cylinder l8. Thus, when the seal uncovers vent port 48 in the? discharge opening position, atmospheric air is drawn into the container through the open vent passage and the uncovered vent open ing.

In Figure 4, a liquid dispensing pump generally designated 3OB Is similarly constructed as tho aforedescribed embodiments except for the valving features In addition, valving element 26 has an inner concentric sleeve 53 defining en annular space with the cylindrical wall of the valving element for the reception of the return spring k2 and having an inner Cylindrical wall along which pisto.'. skirt 38 slidingly and sealingly engages. Valving element 26 is extended for engagement by means of its annular flange 5¾ with the outer end of cylinder lft in the discharge closing position» This ls a fluid tight engagement since valving element 26 also functions as a vent vslv© in this embodiment · The skirt of the piston slides along the inner surface of the valving element in a fluid tight manner during the pumping operation.

To facilitate venting, element 26 has a smeller outer diameter relative to the inner diameter of cylinder l8 between the vent valve and outlet valve 3¾ oo as to define an annulus 55« At least one axially extending groove 56 is provided in the wall of cylinder 18 between this annulus and flange 5^» Thus, in the discharge opening position? valve 3¾ shifts outwardly as in the other embodiments described above as does the outer (annular wall of the valving element thereby $ ί a causing flange 54 to shift outwardly to define ^n open vent passage fsom the atmosphere to the cont&ineK vie open groove 56, annulus 55 and the container vent which is now uncovered.

A further embodiment of the invention is shown 5 in Figure 5 es a liquid dispensing pump 10c which is essentially the same as that of Figure 1 except that the piston and valving member axes are parallel to the discharge passage 13 rather than extending at an angle between the inlet and discharge passages as before. Also* end wall 19c of the pump body* end wall 27c of valving element 26c* and the piston head of piston 37 c are all flat and substantially parallel to one another* as shown* so as to lie perpendicular to the common axes qf the cylinder* and the valving &nd piston elements. Otherwise* the operation of the pump is essentially the same as that described®in detail with reference to Figure 1. While only a section of this dispensing pump XOC ia shown, it should be noted that a portion of shroud 24 is sealed against the upper end of the passage which terminates in outlet port 22 eto as to ('avoid leakage.

Still another embodiment of the trigger ©prayer according to the Invention is generally designated l&o in figure 6* and Is (Similar to sprayer 10A of Figure 3 regarding the venting feature. f3owev©r^ unlike the foregoing t embodiments* trigger sprayer 10D has is piston 37d with no shirt or lip seal 38 s<, that the volume of pump chamber 39 is a enlarged product additionally fills the annular space between cylinder IS and the piston. And* although valving element 26 1© the same as that of the Figure 3 pump, ί ζ only the Inlet valve portion 31 thereof functions the sarae f?is in Figure 3. Otherwise, valving element 26 of Figure 6 has no accumulator function or effect. Flange 34 of the valving element seals against ring 33 under the force of spring -i2 but cannot be dislodged from this seeling position contrary to the aforedescribed sprayers. Since the piston operates within cylinder 18 which functions as ® pump cylinder, rather than within the valving element which functions as a pump cylinder in the foregoing embodiments, lip seal 36 of the valving element functions as a discharge valve in the Figure 6 embodiment in response to an Increase in hydraulic pressure within the pump chamber during the compression stroke so as to flex radially inwardly away from the inner wall of cylinder 18 for opening the discharge, while remaining closed at all other times. Thus, by ©imply removing piston skirt 38, sprayer 1Θ& of the pressure accumulating type is converted into a sprayer 100 of the throttling type in which lip seal 36 /unctions as a circular bunsen valve in the discharge path which opens from hydraulic pressure within the pumping bore «during the piston compression stroke,, and remains closed during the piston suction stroke» All other parts of the sprayer are thus interchangeable with the parts of sprayer 10A, although ©prayer 109 has approximately double the spraying capacity compared to the other ©prayers described above. Also, trigger lever 43 its preferably longer to provide & higher strength for effecting an increased leverage and stroke» Although the venting feature of sprayer 100 is yhown similar to that of sprayer 10A, the venting feature of the Figure 1 sprayer could be adopted without departing frotn the invention and, if decided? the cylinder, valving element and piston of Fig. 6 could lie parallel to the discharge passage as in Fig. 5.

Each of the trigger sprayer embodiments of the invention has shipping seals for the vent passage as well as for the inlet and outlet ports which are automatically self-closing when the pump is at rest and between dispensing strokes. And, each of the sprayers is adapted for fabrication from a minimum number of parts using a minimum number of assembly operations. As noted above, shroud 24 may be integrally fabricated with the remainder of the pump body.

Also, & no£sle*plug 20 can be simply inserted in place together with the trigger lever, and nozzle cap 25 is snapped or threaded into place. Pip tube 1$ is conventional, and the piston, valving element and return spring sre capable of being assembled ®a a sub-assembly and inserted within the bore of cylinder IS. And, the cylindrical connecting portion of the pump body and the Internally threaded closure cap jaay be permanently attached together &s in the manner disclosed In U.S. patent 4,361,256.

The quick opening and slow opening discharge valve» described with reference to Figure 1 ®ipply equally as well to the Figures 41 and 5 embodiments. And, straps 2®, which interconnect th© inlet valve et the tip of wall 27 of the valving bi ember and the base of this wall, shown in detail in Figure 2, are similarly arranged in the valving elements of the Figures 3, 4 and 6 embodiments, as well as in the Figure 5 embodiment except that wall 27c is flat rather than conical therein. A centre! portion of this wall 27c nevertheless functions as an inlet valve. And, straps 28 are neutral from & pressure standpoint and flange 34, together with annular groove , define an accumulation chamber of appreciably larger ft diameter than the pump chamber such that, as the compression force of the piston continues, there will be a progressively increasing fluid pressure within the accumulation chamber until such pressure creates an outward force in an axial direction causing the side wall of the valving element to shift outwardly relative to inlet valve 31 which remains seated during the influence of increased pressure within the pump chamber and against the inlot valve. The straps permit wall 27 or 27c to flex and to resume its initial position during the discharge valve opening and closing operations. Although a plurality of such straps are illustrated, it should be pointed out that as few as two straps snay be provided without departing from the invention. Moreover, the straps may be shaped other than shown, so long as they are extendable between tip and base of wall 27 to facilitate roletiv® axial shifting during the pumping operation as in the manner aforedescribed. ts And, by simply providing a piston member without a piston skirt 30, a sprayer oi the pressure accumulating type can be easily converted into a sprayer of the throttle type having an Increased pump capacity. ft 6

Claims (9)

CLAIMS :

1, A liquid dispensing pump which includes: a pump body defining a pressure accumulation chamber having an axially directed Inlet port for communication with a source of flowable product to be dispensed, and an outlet port at the periphery of the said chamber; a unitary element including an inlet check valve controlling the said inlet port and further including an outlet valve disposed for axial movement in said chamber from a closed position in which it blocks communication between said ports to an open position in which is established communication between said ports; a pump cylinder defining a pump chamber coaxial with the said pressure accumulation chamber and in open communication therewith; a pump piston reciprocable in said cylinder independently of the movement of the said outlet valve; resilient ««antt normally urging the said outlet valve toward its closed position; end means for manually reciprocating said piston; the said unitary clement comprising a thimbleshaped element having at its inner end a transverse end wall including a central portion constituting the said inlet valve, the said wall being formed with a plurality of elongate openings establishing the o^en communication between the said chambers, and defining therebetween flexible straps which facilitate relative axial shifting of the said inlet and outlet valves during a pumping operation .

2. A liquid dispensing pump according to claim 1, wherein the said resilient means comprises a coil spfing encircling the said piston and compressed axially between the piston and the unitary element.

3. « A liquid dispensing pump according to claim 1 or 2, wherein the pump body includes mutually perpendicular inlet and outlet passages respectively terminating in said inl©t and outlet ports, the axis of said unitary element and said piston extending at an angle to both passages, or parallel with tho outlet passage. A liquid dispensing pump according to claim 1, 2 or 3« wherein the pump body has a cylindrical wall including a vent passage to establish communication between a container to which the pump is applied and the atmosphere, either the piston or the unitary element having a vent seal in engagement with the cylindrical wall for opening and closing the vent passage.

4. 5o A liquid dispensing pump according to any one of claims 1 to wherein the said pressure accumulation chamber is defined hy the inner end of the said unitary element and a confronting end wall of the chamber, th

5. 6» A liquid dispensing pump according to any one of claims 1 to wherein the said pressure accumulation chamber is defined by the inner end of the said unitary element and s confronting wall of the chamber, and the said unitary element has an annular groove defining said Outlet valve in the form of an annular valve flange, said pump body having a cylindrical wall containing said outlet port, the said valve flange engaging the said cylindrical wall inwardly of the outlet port in ®h closed position of th© outlet valve and operating a® ffl ei low acting outlet v©Xv© o 1 8

6. 7. A manually actuated dispensing pump comprising a pump body for mounting with a closure cap at the upper end of a container for fluent product, the pump body comprising a pump cylinder open at its outer end to atmosphere and defining within which is provided at its inner end region, a pump chamber for a manually reciprocable piston, the cylinder having in its lower region a vent port t positioned outwardly of the chamber and in permanent open communication with the interior of the container, the pump further * comprising a thimble shaped valving element which is axially reciprocable within the pump cylinder in response to differences between pump pressure acting on the element and an opposing spring force, the said piston being received in the said element to define a pump chamber, the valving element and cylinder defining between them a pressure accumulation chamber in open communication with the pump chamber, the valving element engaging tne inner surface of the cylinder and having a flange engaging the outer end of the cylinder in a rest position of the piston, and the cylinder being formed adjacent its outer end, in its inner surface, with a vent passage the valving element being formed in its outer surface with vent means, outward axial movement of the valving element during pumping acting to disengage the flange from the pump cylinder and to permit the free flow of air between atmosphere and the interior of the container through the vent passage, vent means and vent port. < I

7. 8« A pump according to claim 7, wherein said vent passage comprises a groove.

8. 9. A pump according to claim 7 or 8, wherein said vent means comprises an annulus. 5 10. A liquid dispensing pump according to claim I, substantially as hereinbefore described with particular reference to and as illustrated in the accompanying drawings. II. A manually actuated dispensing pump according

9. 10 to claim 7, substantially as hereinbefore described with particular reference to and as illustrated in Figure 4 of the accompanying drawings.