Background of the Invention
This invention relates generally to a dispensing pump wherein the pumping action is effected through deformation of a resiliently flexible bulbous diaphragm. More particularly, the diaphragm is provided with annular skirts for simultaneously opening and covering discharge and inlet ports upon deformation of the diaphragm, and for opening and covering a vent port in response to a given fluid pressure within the vent port.
U.S. Pat. No. 3,785,532, dated Jan. 15, 1974 and commonly owned herewith, discloses a dispensing pump of the press bulb type having inlet and discharge valves for respectively controlling the closing and opening of inlet and discharge passages upon axial deformation of a bulbous diaphragm. As is typical for this type of dispensing pump, as well as for dispensing pumps disclosed in U.S. Pat. Nos. 2,815,890, 2,853,210, and 3,102,489, after the pump chamber is filled with the product to be dispensed, the product is discharged from and subsequently refills the chamber each time the diaphragm is depressed and released. Further disclosed in U.S. Pat. No. 3,785,532 is a vent for the container which communicates with the atmosphere when dispensing the product. However, in order to dispense the product, a discharge spout and an outer member must be relatively rotated so as to bring discharge port segments of the outer member and an inner member into registry. A groove and a vent are likewise placed in communication with one another during such relative rotation so as to permit the venting of air from the atmosphere into the container interior during the dispensing operation.
Despite the advantages over the prior art arrangements with the use of the dispensing pump set forth in U.S. Pat. No. 3,785,532, relative rotation of parts thereof is required prior to dispensing for the purpose of not only registering discharge port segments but also for registering vent port segments necessary for the dispensing operation. Therefore, the number of parts required to be formed and assembled in carrying out such an operation results in a more costly and complex dispensing pump arrangement.
Summary of the Invention
It is therefore an object of the present invention to provide an improved dispensing pump having an absolutely minimum number of parts and being so arranged for easy production and assembly of the parts so as to produce a dispensing pump which can be operated more efficiently and manufactured more easily and economically.
Another object is to provide such a dispensing pump as having a flexible bulbous diaphragm with annular skirts thereon for effectively controlling inlet, discharge and vent ports upon deformation of the diaphragm during the dispensing operation.
A further object is to provide such a dispensing pump wherein the diaphragm with its annular skirts avoids the need for any specific registry or port segments during both assembly of the pump and prior to the dispensing operation.
A still further object of this invention is to provide such a dispensing pump wherein the skirts are so disposed relative to their respective ports that an inner one of the skirts closes an inlet passage as the diaphragm is deformed, an intermediate one of the skirts normally closes the discharge port and is deflectable to uncover such port in response to increased fluid pressure within the pump chamber, and an outer one of the skirts normally closes the vent port but is deflectable to open such port in response to decreased fluid pressure within a vent passage.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
Brief Description of the Drawings
FIG. 1 is a vertical sectional view taken through a dispensing pump in accordance with the present invention;
FIG. 1A is slightly enlarged partial view of the pump housing without the diaphragm;
FIG. 2 is a sectional view of the pump taken substantially along line 2--2 of FIG. 1;
FIGS. 3 and 4 are sectional views similar to FIG. 1 but showing the operation of the skirt vents during deflection of the diaphragm; and
FIG. 5 is a slightly enlarged plan view section of an annular vent groove provided in the housing.
Description of the Preferred Embodiment
Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, the pump structure of the invention generally comprises a pump housing 10 and an elastic resiliently flexible bulbous diaphragm 11. A cylindrical sleeve or cap 12 is either fixedly or rotatably secured to the housing for operatively supporting the pump structure on a conventional product container such as a bottle, jar or can as the internally threaded cap 12 is threaded onto the neck or dispensing opening of container 13. Both the housing and the cap are adapted for formation from a suitable resilient plastic material such as linear polyethylene.
The housing is generally of an elongated configuration shown in the drawings and may be circular or polygonal in horizontal cross-section so that the housing may be gripped by a hand of the operator and as in the manner of a pistol handle. Also, a recess 14 is provided in a side wall 15 of the housing, and diaphragm 11 is seated over this recess in such a manner that its crown portion 16 protrudes outwardly of the side wall. Therefore, the diaphragm may be depressed inwardly of the recess by a finger of the operator's hand which simply overlies the diaphragm as he grips the handle for trigger-like actuation thereof.
Recess 14 has a conical wall 17 sloping inwardly of its bottom flat wall toward the central axis of the recess. As shown more clearly in FIG. 1A the larger end of this conical wall terminates at an edge 18 lying inwardly of sidewall 15 of the housing.
An inlet passage 19 is formed in the housing and extends from an inner endwall 21 of the housing and is bent at 90.degree. intersecting with conical wall 17 of the recess. A discharge port 22 likewise intersects with conical wall 17 between the bottom wall and the outer end of the recess. A discharge passage 23 is also formed in the housing so as to communicate with its discharge port and to open into the atmosphere through sidewall 15. The housing further contains a vent passage 24 extending toward the diaphragm from end wall 21 for the purpose for venting the interior of the container to the atmosphere in a manner to be hereinafter described. A dip tube 25 is secured in place within the inlet passage so as to extend this passage toward the bottom wall of the container in the normal manner.
As shown in the drawings and especially in FIG. 1A, the housing is provided with concentric annular recesses 26 and 27 defining an annular projection 28 therebetween.
Diaphragm 11 is provided with integral annular skirts 29, 31 and 32 extending inwardly of the housing. Inner skirt 29 lies against conical wall 17 of the recess, while intermediate skirt 31 and outer skirt 32 are seated sealingly within annular recesses 26 and 27, respectively. The diaphragm therefore forms together with recess 14 a pump chamber 33, the volume of which may be readily varied by deformation of crown portion 16 of the diaphragm, preferably by inward finger pressure exerted thereagainst.
The diaphragm including its skirts 29, 31 and 32 is of a material such as natural or artificial rubber which has sufficient flexibility and elasticity so as to be resiliently deflectable. Thus, annular skirt 29 normally covers inlet passage 19 at its opening into pump chamber 33 during the depression stroke of the diaphragm (FIG. 3) when the pump chamber is filled with fluid. During the release stroke of the diaphragm as shown in FIG. 4, skirt 29 is sufficiently flexible to move inwardly of the recess to uncover the inlet passage in response to the vacuum pressure created in the pump chamber during refilling. The lower end portion of intermediate skirt 31 extends sufficiently inwardly of the pump housing so as to normally close discharge port 22. This lower end portion is sufficiently flexible, however, as to deflect outwardly as shown in FIG. 3 to uncover the discharge port in response to increased fluid pressure within pump chamber 33 as during inward deflection of the diaphragm.
For the purpose of venting the interior of the container to the atmosphere during the dispensing operation, an annular vent port 34 is provided in annular projection 28 as shown in FIG. 5. This vent port has a vent seat 34a communicating with passage 24, and opens at the free end of projection 28 as shown in FIG. 1A. A through opening 35 is provided in the diaphragm so as to connect port 34 with the atmosphere. Also, it can be seen that the lower edge portion of skirt 32 extends into annular recess 27 sufficiently to fully cover vent seat 34a without completely overlapping vent passage 24. Accordingly, this flexible end portion will deflect outwardly away from seat 34a as shown in FIG. 4 in response to a decrease of fluid pressure within the vent passage as during a refilling of the pump chamber after its contents have been dispensed.
The housing is also provided with an annular flange adjacent outer skirt 32 for the purpose of anchoring the diaphragm in place after this flange has been swaged over a portion of annular shoulder 37 of the diaphragm which lies substantially flush with side wall 15.
In assembling what is essentially a two part dispensing pump, diaphragm 11 is seated over recess 14 of the pump housing so that its three annular skirts are disposed as aforedescribed. Flange 36 is then swaged over shoulder 37 of the diaphragm to anchor it securely in place. The inlet, discharge and vent valves thus constituted by skirts 29, 31 and 32, respectively, require no particular angular orientation with respect to housing 10 since these valves are operative in all positions of rotative orientation on the housing. Also, since vent port 34 is annular, communication with opening 35 is assured for any rotative orientation of the diaphragm respecting the housing.
In order to dispense the product, the diaphragm is depressed inwardly at its crown portion so that any air trapped in pump chamber 33 is correspondingly pressurized so as to open the discharge valve defined by skirt 31 to be released through port 22 and discharge passage 23. As the diaphragm is so depressed, the internal pressure within the chamber likewise forces skirt 29 outwardly so as to cover inlet passage 19. As the finger pressure is released and crown portion 16 of the diaphragm is permitted to re-expand to its normal volume as shown in FIG. 1, the vacuum created within the pump chamber 33 causes skirt 31 to be pulled tightly against the discharge port and at the same time forces skirt 29 inwardly away from the inlet passage to thereby draw the flowable product upwardly through dip tube 25. After one or more depressions of the diaphragm the product is drawn into the pump chamber for substantially filling same.
After the product is received within pump chamber 33, each inward depression of the flexible diaphragm toward the pump chamber will force the product outwardly therefrom and through discharge port 22 with sufficient pressure to open discharge valve 31 so that the product may flow beneath the lower edge of that valve as shown in FIG. 3 and thereafter outwardly through discharge passage 23. Of course, the pump may be actuated by intermittent pressure on the flexible diaphragm to dispense as much of the product as is desired.
Upon release of the diaphragm the inlet valve constituted by inner skirt 29 is moved inwardly of the pump chamber as aforedescribed by means of the vacuum created within the pump chamber as its volume returns to its initial position. The discharge valve constituted by intermediate skirt 31 is accordingly drawn inwardly against the discharge port for covering same, the interior of the container is vented to atmosphere as the product is filling the pump chamber. While the diaphragm crown portion is being depressed inwardly, opening 35 in the diaphragm is slightly stretched so as to assure open communication between the vent port and the atmosphere. Such venting is therefore effected by the vacuum pressure created in the container during the refilling operation, the vacuum pressure causing a lower portion of skirt 32 to be drawn outwardly away from seat 34a of the vent port (see FIG. 4). Thus, as the lower edge portion of skirt 32 is pulled outwardly away from the vent seat, distortion of the diaphragm crown portion maintains opening 35 open so as to permit air to be vented therethrough, into the vent port, through the vent passage and into the interior of the container as necessary to replace the product withdrawn therefrom by the pump. And, by the time the diaphragm returns to its initial position of FIG. 1, the pump chamber will be refilled with the product, opening 35 will be closed because of the constriction thereof caused by a crown portion, and vent seat 34a will be closed by the lower end portion of skirt 32.
From the foregoing it can be seen that only a minimum number of parts is required for the present dispensing pump, and that no particular angular orientation of the diaphragm is required relative to the housing. Also, no registry between elements of the pump is required prior to dispensing.
Obviously, 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 appended claims the invention may be practiced otherwise than as specifically described.