Pressurized Dispenser

Abstract

A resilient bladder-type dispenser wherein the bladder, when empty, is prestressed over a mandril extending into the dispenser. The bladder is provided with a flexible, flat bottom wall which is self-aligning over a tapered mandril. An annular enlarged diameter portion is provided on the bladder near its upper edge for forming a fold to maintain the bladder in fluid tight relationship with a gland which can be mounted in the dispenser to lock the bladder in place. A dispensing valve is provided in the bladder so that when the valve is opened the bladder walls force fluids therefrom. A stop is provided so that when the dispenser cap which actuates the valve is oriented in a certain manner, the valve cannot be inadvertently activated.

Description

This invention is directed to a dispenser for dispensing fluids from a pressurized container, more particularly it is directed to a pressurized fluid dispensing container wherein the pressure for dispensing is obtained by contraction of an expanded resilient membrane or bladder.

This invention is an improvement over the basic concept of using a prestressed bladder or membrane for dispensing fluid materials as disclosed in the above-mentioned copending application. In the prior device a prestressed bladder was mounted externally of a cylindrical mandril and over the mandrilso that the bladder was substantially empty in its prestressed, fully-contracted position within the container. The device was developed to meet a diversified market requirement for dispensing fluid products thick and thin with an improved low cost pressurized package dispenser. The dispenser should satisfactorily accommodate these products and improve their sales appeal by providing a convenient pressure package. The basic concept of a pressurized bladder-type dispenser has been found to be highly advantageous for use in the dispensing of fluids of varied viscosities and flow characteristics.

In general, the self-pressurized, prestressed-bladder-type container has the following advantageous characteristics:

A. The basic container, in its pressurized state, is non-explosive.

B. The container does not use a gas propellant for pressurization which is the most common method now used.

C. The container assembly can be made of plastic, metal, or glass; the preferred material being plastic with its wide latitude of fabricated shape configurations and the ability of being less vulnerable to damage or breakage under normal consumer use.

D. The external container shape is virtually unlimited for distinctive design within the practical scope of effective and economic functional design.

E. The common need for new formulations of the fluid product for compatability with the gas propellant is eliminated.

F. In most applications the pressurized container will hold more fluid product than normally found in an aerosol container of similar size and volume since no internal space is allotted for the volume of gas propellant.

G. The container and pressurization system can be so designed to provide virtually full expulsion of the fluid product contained in the container.

H. The container and pressurization system can be designed to provide an uninterrupted spray dispensing as well as an uninterrupted stream flow dispensing of fluids.

i. The container will dispense contained fluid from any positioned attitude.

This invention is directed to a dispenser having novel features and incorporating cost saving structural modifications which greatly enhance the manufacture and assembly of the dispenser. For example, it has been found that by changing the bladder construction, the resilient sealing ring at the upper edge of the bladder can be eliminated without eliminating the hermetic seal between the bladder and the container which prevents leakage of fluid from the bladder or air into the bladder. The elimination of the sealing ring, while superficially unimportant, affords a tremendous savings in construction and assembly time.

The elimination of the O-ring type seal also eliminates the need for machining of a base member to form a seat for the ring. This invention includes a bladder-valve interface which seals the bladder without the requirement for close tolerances or timely alignment of an O-ring seal.

Basically this invention is directed to a low cost, high volume production, commercial pressure dispenser for fluids in the consumer product fields; for example foodstuffs such as catsup, mayonnaise, mustard and syrups, toiletries such as hand creams, after shave lotions, shampoos, preshave lather, toothpaste and household products such as car wax, floor wax, polishes for cars or furniture, fluid detergents and in general a variety of cleaning fluids. Additionally the dispenser of this invention can be used for dispensing medical materials such as injectables of plasma and other intravenous solutions as disclosed in the aforementioned patent application. One of the features of this invention is that the entire dispenser can be easily assembled without precise machining of the parts.

The device, once assembled, is tamperproof and can be placed in a nondispensing condition so that it can be shipped or handled without danger of inadvertently actuating the dispenser valve and causing loss of the fluids contained therein.

Additionally another of the features of this invention is that the container can be assembled without careful and tedious alignment of the prestressing mandril and the membrane.

The bladder or membrane used with the dispenser of this invention is for all practical purposes self-aligning with the elongate mandril which prestresses it so that in the fully contracted condition the dispenser is substantially empty of fluid. This self-alignment is accomplished by means of an axially tapered mandril which extends from the bottom of the container upwardly toward the fluid outlet and which receives the membrance over it to place the membrane in the prestressed condition. The membrane is constructed to include a substantially flat bottom wall which fits over the upper surface of the mandril and due to its resiliency forms a concavity over the upper mandril surface. The use of a tapered mandril permits the membrane to easily slide down over the mandril folding the inner surfaces of the lower portion upwardly against the upper portion thereby prestressing the membrane by an increasingly greater degree as it extends downwardly axially along the mandril. This assists in forcing fluids from the lower portions of the membrane.

Another feature of this invention is that the membrane may be provided with both upper and lower air vents and a vent cover which renders the dispenser less susceptible to damage by puncture of the membrane and makes it substantially tamperproof.

Still another feature of the dispenser device of this invention is that the outer design of the dispenser body can be tailored to the product being dispensed and consumer appeal without alteration of the basic dispensing valve mechanism or the fluid-containing prestressed bladder.

Another feature of the dispensing device of this invention is that the dispenser can be rapidly filled and the fluids can be dispensed at the desired rate for each different fluid by simply varying the dispensing orifice independent of the filling orifice.

Another feature of this invention is that the dispenser can be refilled after using or can be discarded after the membrane is entirely emptied. Either the reusable or disposable dispenser can be made in accordance with this invention since while the device is sturdy and durable it can be constructed at a sufficiently low expense so that it can be discarded after a single use.

Another principal feature of the dispenser of this invention is that a fluid tight seal is effected between the membrane and the dispenser during assembly without providing an O-ring on the membrane before insertion into the dispenser.

Another feature of the dispensing device of this invention is that the control orifice for dispensing can be made independent of the orifice for filling the dispenser to provide the optimum size orifices for both operations.

These and other features of the invention as described herein will become more readily apparent from the detailed description and appended claims when taken in conjunction with the attached drawings which are briefly described as follows:

FIG. 1 is a vertical partial section through the axis of the dispenser body constructed in accordance with this invention showing the bladder filled with a fluid to be dispensed;

FIG. 2 is a partially exploded sectional view of FIG. 1 with the bladder emptied;

FIG. 3 is an enlarged vertical sectional view of the valve mechanism and membrane seal of a dispenser constructed in accordance with this invention;

FIG. 4 is a horizontal sectional view taken substantially along lines 4--4 of FIG. 3;

FIG. 5 is a horizontal sectional view taken substantially along lines 5--5 of FIG. 3;

FIG. 6 is an exploded view of the valve mechanism and activator cap of FIG. 3;

FIG. 7 is a perspective view of the bottom cover for a dispenser constructed in accordance with this invention;

FIG. 8 is a somewhat diagrammatic view showing the action during assembly of the upper bladder wall; and

FIG. 9 is an alternative view of the manner in which the bladder can be mounted in a device constructed in accordance with this invention.

Referring now to FIG. 1, the dispenser body 10 may be basically formed of two coaxial frustroconical portions 12 and 14. The upper portion 12 is shorter and has a larger apex angle than the lower frustroconical portion 14. A partial top wall 16 on the upper portion 12 as best shown in FIG. 3, forms a base which limits the downward movement of a cap 18 which is attached thereto. The cap 18 is also provided with an outlet nozzle 20 having a dispensing orifice 22 therein (see FIG. 3).

The lower portion 14 of the body 10 has an annular lower edge 24 and an inner surface 26.

The body 10 is adapted to fit on a base member 28 having an upper annular shoulder 30 and an upwardly extending inner shoulder flange 32 thereon. The flange 32 is of sufficient outer diameter so that it can be inserted within the body 10 into contact with the inner surface 26 of the lower portion 14. In this fashion, the lower edge 24 of the conical portion 14 fits firmly on the annular shoulder 30. The body 10 and the base 28 are joined with an epoxy bonding material or by ultrasonically welding the two parts. Ultrasonic welding is preferred since it is fast, clean and can be adapted readily to use on an assembly line.

The lowermost wall 36 of the base portion 28 is provided with an annular groove 38. At the base of the annular groove 38 there is provided one or more annular flat bottomed holes 39 which have an orifice or air vent 40 therein. A base cover 41 having a plurality of annularly spaced tabs 43 thereon (see FIG. 7) is provided for preventing access to the air vents 40. The tabs 43 snap into the groove 39 to lock the cover in place without blocking the air vents 40. A slight clearance is maintained between the wall 36 and upper face of cover 41 to provide communication between the atmosphere and the interior of body 10 via the vents 40. The cover 41 may be removable so that tabs 43 can be snapped out of the groove 39 by using a flat instrument to pry up the edges of the cover 41. This permits the inner portion of the mandril to be used for storage space for example for utensils to be used with the dispensed fluids. The preferred embodiment is to mount the cover 41 in place so that it can be removed only with difficulty, however.

At the center of the bottom wall 36 a hollow, upright, elongate mandril 42 which is integral with the bottom wall 36 extends upwardly toward the top of the dispenser. The outer wall 44 of the mandril 42 tapers upwardly so that the upper circumference is slightly smaller than the lower circumference of the mandril 42. The mandril 42 has a smooth hemispherical upper surface 46 at its free end which smoothly merges with the outer wall 44 for receiving a cylindrical resilient bladder or membrane 50 thereover. The diameter of the upper portion of the mandril 42 is slightly less than the diameter of the bladder 50 and tapers to a diameter larger than the diameter of the bladder so that the bladder 50 must be expanded to fit over the mandril but can be started with ease. The bladder 50, as shown in FIG. 1, preferably extends down over the mandril for about one half the distance from the dispenser wall 16 adjacent the bladder outlet to the opposite end of the bladder.

With reference now to FIG. 2, it can be seen that the resilient membrane bladder 50 has a cylindrical side wall 51 and a substantially flat lower wall 52. The wall 52 fits over the upper surface 46 on the mandril 42 when the dispenser body 10 is fitted onto the base 28 so that the lower edge 24 of the body fits over the flange 32 onto the shoulder 30. The resilient membrane 50 is mounted within a flange 54 on the upper wall 16 as will be discussed. The lower wall 52 of the membrane 50 is a circular, disc-like member integrally formed with the membrane. The wall 52 may be of a slightly larger diameter than the diameter of the cylindrical side wall 51 of the membrane 50 so that the wall 52 can resiliently flex between a slightly convex and a slightly concave configuration. When the lower wall 52 initially contacts the upper surface 46 on the elongate mandril 42, the wall flexes into its concave position helping to align the membrane with the mandril.

An enlarged diameter portion 53 is provided near the upper edge 55 of the membrane 50. The membrane 50 is divided into an upper axial portion 50b and a lower axial portion 50a by means of the enlarged diameter portion 53. Portion 50b is folded inwardly on the portion 50a to form a fluid tight seal during assembly. The membrane 50 may be formed from natural rubber latex or neoprene latex by a dipping process, centrifugal molding or otherwise.

As shown in FIG. 3, the partial upper wall 16 of the dispenser body is provided with an upwardly extending annular wall 60 which has a radially outwardly protruding annular lip 62 near the upper edge 64 thereof.

Inwardly of the upwardly extending wall 60, as best shown in FIGS. 3, 4 and 6, the wall 60 is provided with circumferentially extending vertically stepped, horizontal surfaces 66, 66', 67, 67' and 68. The surfaces 67 and 67' are recessed below the surfaces 66 and 66' thereby forming shoulders 70 and 72 at the ends of the surfaces 67 and 67'. The midpoints of the surfaces 66 and 66' are circumferentially spaced from each other by approximately 180.degree. thereby forming symmetrical circumferential steps on the inner surface of the flange 60. At one end of each of the surfaces 66 and 66' there is a shoulder 74 (one shown) which acts as a stop member as will be discussed.

A plurality of vents 69 are provided through the upper wall 16 to assist in evacuation of air as the bladder is filled (see also FIG. 6). The cap 18 is positioned over the vents 69 so that they are not accessible from without the container without complete removal of the cap 18.

The lower surface 68 corresponds with the innermost upper surface of the inwardly extending wall 16 and terminates in a circumferentially extending vertical edge 76 which defines the opening into the dispenser body. The inner surface 76 is connected to the downwardly extending flange 54 by means of a curved surface 78 as best shown in FIG. 6.

Referring again to FIG. 3 it will be seen that the cap 18 is provided with a sloping frustroconical side wall 80 which forms a straight continuation of the outer wall 12. An annular vertically extending groove 82 is provided in the lower edge of the outer wall of the cap. Near the lower edge of the groove 82 on an outer surface 84 is provided an annular lip 86. The lip 86 is adapted to snap over the lip 62 on the upstanding wall 60 of the dispenser body thereby forming a snapable attachment for holding the cap onto the body. The diameter of the lip 86 and the lip 62 are substantially equal. Both the wall 60 and the lower portion of the wall 80 are sufficiently resilient to enable some radial deflection inwardly and outwardly respectively to permit this snapping of the cap into place. The wall and the lower portion of the outer wall of the cap are sufficiently rigid so that the interlock between the lips 62 and 86 is sufficient to prevent accidental removal of the cap.

The inner edge of the groove 82 is formed by a pair of downwardly and annularly extending tabs 88 and 88', as best shown in FIGS. 4 and 6. The tabs 88 and 88' are oppositely spaced about the circumference of the wall 60 and are adapted to seat on the surfaces 66, 66', 67 and 67' as will be discussed.

As best shown in FIG. 3, the orifice 22 has a horizontally extending portion 22a and a vertically extending portion 22b formed by a depending tubular neck 90 which extends downwardly from the central section of the cap and has an annular lower bottom edge surface 92 thereon.

The membrane or bladder 50 is held in place near its upper edge by means of a gland member 94 which comprises a cylindrical body 96 having an upper radially inwardly extending flange 98 at the upper end thereof. A downwardly extending annular flange 100 is provided at the inner edge of the flange 98 so that the flange 100 is radially spaced from the body 96. The annular flange 100 forms tubular passage from the cap into the body of the bladder, as shown in FIG. 3. The radial spacing between flange 100 and the body 96 provides an annular recess where solids can collect without interferring with the valving action. The bottom surface 102 of the downwardly extending flange 100 forms a seat for a valve as will be discussed.

The outer surface of the wall 96 near its midpoint is provided with an integrally molded shoulder 110 which has a series of radially extending flexible tab members 112 integrally connected to the lower edge thereof and circumferentially spaced around the wall 96. These tabs, as shown in FIG. 3, receive the upper end of the bladder 50. This assembly is highly beneficial to the overall commercial value of the dispenser of this invention since it mounts the bladder 50 without extensive adjustment or alignment of parts. The bladder portion 50b is merely folded inwardly back on the portion 50a at enlarged diameter portion 53 by the upper and external diameter section of the cylindrical body 96 and the fold is inserted intermediate the gland body and the tabs. When the gland is inserted into the dispenser the flange 54 and the curved section 78 force the pressure exerting tabs 112 into a tight, locking and sealing engagement with the enlarged diameter section 53 of the bladder, thus forming a fluid tight seal between the bladder and the gland body 96.

The tabs 112, as also shown in FIG. 6, comprise a radially outwardly thick portion 114 which has a central reinforcing member 116 mounted thereon. The tabs 112 are connected to the shoulder 110 by means of thin radially and axially tapered flexible hinge-like portions 117 which permit the tabs to be resiliently bent downward toward the gland body 96. The surface 114 has a fairly small radius of curvature so that when it is pressed against the bladder 50 it will hold the bladder in place while the central strengthening strip 116 will abut against the annular flange 54 of the dispenser body. With continued reference to FIG. 6, it will be seen that the gland 94 also is provided with an upper edge 118 of the shoulder 110 which peripherally extends around the body of the gland 94.

Referring again to FIG. 3, it will be seen that the valve for permitting the paste or liquid, which is within the membrane 50, to be dispensed is a three piece valve mechanism 120. The upper movable valve portion 122, as shown in FIGS. 3 and 6, includes a hollow, cylindrical, tubular body portion 124 which depends downwardly from a circular base member 126. The base member 126 has an annular upstanding ridge 128 at the outer periphery thereof. The ridge 128 tapers upwardly to a sharp point 130 at its upper edge, as best shown in FIG. 3. Four guide and spacer members 132 are radially and peripherally spaced from the center of the base 126 so that their outer surfaces 134 lie along the circumference of a circle which has a diameter slightly smaller than the inner diameter of the depending flange 100 on the gland 94 so that the guide and spacer members can move freely within the flange 100. The peripheral spaces between the members 132 provide flow ports which are positively shut off by the flange 100 when the valve is closed. The sharp upper edge 130 of the ridge 128 seats on the lower surface 102 of the annular flange 100 thereby forming a valve closure. The guide and spacer members 132 keep the valve member 122 aligned within the gland 94 so that the edge 130 will seat properly on the lower surface 102 of the annular flange 100 and by means of the defined flow ports provide a second valve closure for positively blocking fluid flow.

A helical biasing spring 135 is provided to urge the valve member 122 upwardly. The lower end of the helical spring 135 seats in a well defined by a member 136 of the valve.

The valve member 136 comprises a generally flat base 138 having an arrangement of axially extending perforations such as the annularly arranged orifices 140 therein (see FIG. 5). A centrally located cylindrical spring receiving wall 142 extends upwardly from the base 138. The bottom surface of the base 138 immediately below the wall 142 is generally designated as 144 and is upwardly concave as best shown in FIG. 3. The outer periphery of the base 138 has an annular flange 145 depending therefrom. The flange 145 prevents the bladder from interferring with fluid flow by being forced into blocking relationship with the orifices 140.

A small annular lip generally extends upwardly, as shown by lip 146, for aligning the lower valve member 136 with the lower edge of the wall 96 of the gland. The lip 146 is of sufficiently large diameter to fit snugly within the cylindrical wall 96. The lower edge may include an annular groove 150 in the lower surface thereof and a cooperating ridge or annular tongue 152 may be molded into the upper surface of the base 138 of the lower valve member 136 for positively aligning these members. However the preferred use of the annular tongue 152 is for providing a deformable material member for use in ultrasonically welding valve member 136 to gland member 94 with lower portion of gland member 96. When ultrasonic welding is employed the annular groove 150 is eliminated and the lower edge of the body 96 is flat.

The peripheral arrangement of the fingers or tabs 112 of the gland 94 and the orifices 140 in the valve member 136 are best shown in FIG. 5. The materials used for the dispenser of this invention may be a flexible plastic such as the ABS resins, polypropylene, polyethylene, nylon or a silicone rubber. The spring 132 of course is constructed from a resilient metal. Any type of spring mechanism or any flexible materials can be used to construct the dispenser as disclosed herein. Additionally rather than having lands machined on the various portions of the dispenser the stepped surfaces may be integrally molded with the individual body portions by injection molding.

The body and cap of the dispenser may be molded in various colors of synthetic resins depending upon the desired marketing appeal and the material which is to be dispensed.

The dispenser of this invention can be assembled rapidly, efficiently, and with little expense due to the construction of the valve mechanism 120, the gland 94 and the bladder 50. To assemble the dispenser, the valve mechanism 120 is first inserted axially into the upper end of the cylindrical bladder 50. The upper portion 50b of the membrane is folded inwardly and down upon the lower portion 50a (see FIG. 8) by the outside diameter surface portion 96 of the gland member. The enlarged diameter portion 53 provides a fold line as shown in FIG. 8 to facilitate this folding. The folded upper end of the membrane is then inserted between the tabs 112 and the cylindrical wall 96 of the gland 94. This assembly is then forceably and upwardly inserted into the inner annular surface 54 of the upper container body 10. This locks the folded membrane portions 50a and 50b intermediate the tabs 112 and the cylindrical wall 96. The lower end 52 of the membrane is then pressed down over the upper end 46 of the mandril 42. This is easily accomplished since the lower end 52 of the membrane, due to its resiliency, moves into a concave configuration and rides over the mandril so that the membrane is inverted upon itself as shown in FIG. 1. The bladder preferably has its entire lower half inverted and must have at least its lower one fourth inverted to be effectively prestressed. The amount of prestressing applied to the bladder 50 may be regulated by adjusting the relative diameters of the mandril and bladder, the degree of mandril taper and the resiliency of the bladder. Best results have been obtained by making the mandril taper quickly to a diameter slightly larger than that of the bladder so that actually only the end portion of the mandril is of a smaller diameter than the bladder. A slight positive inflation pressure may be applied to the bladder to assist in aligning it and forcing it down over the mandril. This procedure slightly prestresses the bladder so that it will retain its shape in assembly. The air is slowly released as the mandril inverts the bladder.

Preferably the upper surface 46 of the mandril is of the same radius of curvature as the lower surface 144 on the member 136 so that the valve mechanism is easily centered over the mandril. The upper edge 46 of the mandril 42 thus comes into mating contact, with the membrane lower wall 52 intermediate, with the lower surface 144 on the base 138 of the valve member 136. When in this configuration, the valve mechanism and the gland 94 can be inserted by means of the mandril 42 into the upper body portion 12 of the dispenser with the shoulder 110 on the gland 94 fitted within the annular edge 76 of the dispenser body as shown in FIG. 3. As the valve 120, the gland 94, and the upper end of the bladder 50 are pushed into the dispenser, the depending flange 54 of the dispenser body bends the tabs 112 downwardly at the resilient hinge-like members 117 so that the thicker lower portions 114 come into contact with the outer fold portion 50a of the membrane which is folded so that the enlarged diameter portion 53 is at the fold crease. These tabs thus are pressed tightly up against the folded portion of the membrane by the depending skirt or flange 54 thereby forming a fluid tight seal between the gland and the bladder as shown in FIG. 3.

At this stage of assembly the upper container body 10 is joined to the lower portion of container body 28 by some form of material bonding, in preferred case by ultrasonically welding the surface 30 of portion 28 to the surface 24 of upper container body 10 wherein there can be an annular tongue of a prescribed nature on either surface 30 or surface 24 as required for the ultrasonic weld. This completes container assembly without the cap 18.

Alternatively, the container may be assembled to this point by placing the gland 94 and valving mechanism 120 over the bladder and inserting them into the upper portion of the dispenser then forcing the mandril into the bladder. Again a slight positive air pressure may be applied in the bladder during assembly. The bladder is vented through the valve 122 as the mandril is inserted therein.

After the valve and bladder have been installed and the container body portions assembled, the cap 18 is placed on the dispenser by snapping the lip 86 over the lip 62 as previously discussed. The cap can be rotated so that the tabs 88 and 88' are peripherally aligned with the lower surfaces 67 or peripherally aligned with the upwardmost surfaces 66. When the tabs 88 and 88' are aligned with the surfaces 66 and 66' the dispenser is in a non-dispensing position. When the tabs are aligned with the surfaces 67 and 67', however, the cap may be depressed thereby forcing the valve member 122 downwardly so that the ridge 130 moves away from the valve seat surface 102 and permits fluids to be dispensed from the prestressed bladder through the orifices 140 up through the guide and spacer members 132 and out the nozzle outlet 122. As shown in FIG. 3, the spring 135 normally biases the ridge 130 into sealing engagement with the lower surface 102 of the depending flange 100 on the gland 94 so that fluids cannot leak out of the dispenser.

Filling is preferably accomplished before the cap 18 is in place. A tubular member from a conventional pressurized filling machine is introduced into the orifice defined by depending flange 100. This pushes down on surfaces 132 opening the valve 120. The fluids are then forced into the bladder 50 and expand it as shown in FIG. 1. By filling the container before the cap 18 is mounted in place a large fill orifice can be used for rapid fill and a smaller cap dispensing orifice 22 can be used for controlled dispensing.

When the bladder is filled it occupies the inner volume of the dispenser in a highly stressed condition so that when the cap 18 is depressed the fluids are forced out of the bladder.

As a description of the cap action the following is noted. To prevent dispensing of fluids the cap 18 may be rotated counterclockwise so that the flange 88 comes into contact with the stop member 74. When the cap is in this position the containers can be shipped with little danger of inadvertent dispensing. A strip of sealing tape may be placed around the cap and body juncture to prevent inadvertent or intentional rotation of the cap 18 to an actuatable position before sale.

One of the chief advantages of the dispenser of this invention is the ease with which it can be assembled due to the tapering of the mandril 44, the configuration of the bladder, and the novel gland which locks the bladder in a fluid tight relationship inherently with assembly.

Another advantage of the dispenser of this invention is that it can be rapidly and easily assembled. The construction of the membrane or bladder 50 as best shown in FIG. 6 contributes to this advantage. This membrane 50 includes near its upper edge 55 the outwardly extending large diameter portion 53 which divides the bladder 50 into a lower portion designated generally as 50a and an upper portion designated generally in FIG. 6 as 50b. The outer surface of the upper portion 50b of the bladder, when the bladder is inserted onto the gland body 96, folds inwardly so that it is on the inner surface with the enlarged portion 53 at the upper edge and the upper bladder portion 50b folded inwardly into the bladder portion 50a to form the seal during assembly.

As shown in FIG. 9 the bladder upper portion 50b may also be folded outwardly and the same fluid tight sealing fold will be obtained. The outward folding is not effected by the lower edge of the wall 96 or the flange 145 as is the inward folding shown in FIG. 8. Rather, the upper portion 50b must be deliberately expanded outwardly and folded down with the enlarged diameter portion 53 as the crease.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

What is claimed is:

1. A pressure apparatus for dispensing a fluid comprising:

a resilient bladder having wall means defining a fluid chamber interior of the bladder and a fluid outlet in communication with the interior of the bladder;

an outer casing disposed around the bladder and affixed thereto, said casing having an outlet;

additional surface means exterior of the bladder against which a substantial portion of the bladder wall means is stretched for maintaining tension in the bladder wall means in the contracted position so that said bladder is substantially empty of fluid in the contracted position, said means including an elongate member exterior of the bladder and having one end integrally mounted on the inner surface of the casing and the other end interior of the casing, said elongate member being of a smaller cross-section at the end interior of the casing and gradually increasing to a larger cross-section where said elongate member is fixed to the casing, the bladder being disposed around the elongate member so as to contract tightly therearound and being of a size relative to the elongate member such that the elongate member prevents the bladder from contracting to its unstressed size, the difference in size and the elastic characteristics of the bladder being selected in accordance with the desired minimum pressure at which fluid is to be supplied from the container;

said bladder having an elongate cylindrical tubular body of resilient material with an outlet at one end and being closed at the other end by a bottom wall, said bladder having a neck portion adjacent the outlet and said cylindrical body portion being of a transverse cross-section less than the largest transverse cross-section of said elongate member;

said elongate member comprising a tapered mandril integrally fixed to the casing at the end opposite the casing outlet and extending toward the casing outlet; and

said bladder in the contracted position being stretched over the mandril with the closed end of the bladder on the free end of the mandril and the body portion of the bladder stretched down over the mandril and doubled back along the mandril.

2. A pressurized apparatus in accordance with claim 1, wherein the bladder in the contracted position doubles back at a location about one-half of the distance from the casing wall adjacent the bladder outlet to the opposite end of the bladder.

3. A pressure apparatus for dispensing a fluid comprising:

a resilient bladder having wall means defining a fluid chamber interior of the bladder and a fluid outlet in communication with the interior of the bladder;

an outer casing disposed around the bladder and affixed thereto, said casing having an outlet;

additional surface means exterior of the bladder against which a substantial portion of the bladder wall means is stretched for maintaining tension in the bladder wall means in the contracted position so that said bladder is substantially empty of fluid in the contracted position, said means including an elongate member exterior of the bladder and having one end integrally mounted on the inner surface of the casing and the other end interior of the casing, said elongate member being of a smaller cross-section at the end interior of the casing and gradually increasing to a larger cross-section where said elongate member is fixed to the casing, the bladder being disposed around the elongate member so as to contract tightly therearound and being of a size relative to the elongate member such that the elongate member prevents the bladder from contracting to its unstressed size, the difference in size and the elastic characteristics of the bladder being selected in accordance with the desired minimum pressure at which fluid is to be supplied from the container;

said elongate member being tubular to provide a storage space, the interior of the elongate member being closed and the fixed end being open for access to the inner portion of the tubular member, and said apparatus further includes removable means for closing the access to the open end of said tubular member; and

said elongate member being surrounded on said casing by a plurality of air vents and said removable closing means shields said air vents from access from without said casing to the inner portion of said casing thereby rendering said pressurized apparatus substantially tamperproof.

4. A pressure apparatus for dispensing a fluid comprising:

a resilient bladder having wall means defining a fluid chamber interior of the bladder and a fluid outlet in communication with the interior of the bladder;

an outer casing disposed around the bladder and affixed thereto, said casing having an outlet;

additional surface means exterior of the bladder against which a substantial portion of the bladder wall means is stretched for maintaining tension in the bladder wall means in the contracted position so that said bladder is substantially empty of fluid in the contracted position, said means including an elongate member exterior of the bladder and having one end integrally mounted on the inner surface of the casing and the other end interior of the casing, said elongate member being of a smaller cross-section at the end interior of the casing and gradually increasing to a larger cross-section where said elongate member is fixed to the casing, the bladder being disposed around the elongate member so as to contract tightly therearound and being of a size relative to the elongate member such that the elongate member prevents the bladder from contracting to its unstressed size, the difference in size and the elastic characteristics of the bladder being selected in accordance with the desired minimum pressure at which fluid is to be supplied from the container, said apparatus including a plurality of air vents extending through said casing for permitting evacuation of air from said casing and means for preventing access to said air vents from without the casing.

5. A pressure apparatus for dispensing a fluid comprising:

a resilient bladder having wall means defining a fluid chamber interior of the bladder and a fluid outlet in communication with the interior of the bladder;

an outer casing disposed around the bladder and affixed thereto;

additional surface means exterior of the bladder against which a substantial portion of the bladder wall means is stretched for maintaining tension in the bladder wall means in the contracted position so that said bladder is substantially empty of fluid in the contracted position;

means for fixing said bladder to said casing comprising a gland member having a plurality of circumferentially spaced, radially extending pressure tabs thereon;

said bladder including an enlarged diameter portion circumferentially extending around the bladder adjacent the outlet end of said bladder and said bladder being folded back on itself at said enlarged diameter portion with the fold fitted within said gland adjacent said radial pressure tabs; and

means on said apparatus for forcing said pressure tabs into sealing engagement with the fold of said bladder.

6. A pressurized apparatus as defined in claim 5, wherein said bladder is folded back on itself so that the portion of said bladder intermediate said enlarged diameter portion and the outlet end of said bladder extends internally into the bladder.

7. An apparatus as defined in claim 5, wherein said pressure tabs are mounted on the outer periphery of said gland member and have a thin, radially tapered, flexible portion thereon for permitting bending of said tabs and a thick outer portion for applying pressure to said bladder.

8. A dispenser device for supplying fluid material under pressure comprising:

a cylindrical bladder having resilient side wall means which are flexible from an expanded position in which a relatively large fluid chamber is defined interior of the bladder to a contracted position in which the fluid chamber is relatively small, the resilience of the wall means urging the bladder to the contracted position;

an outlet formed in the bladder for the passage of fluid from the chamber;

substantially flat bottom wall means on the bladder which move resiliently between a concave and a convex position;

an outer casing disposed around the bladder;

gland means connected in sealing relationship to the bladder outlet, said gland means having a passage therethrough for flow of fluid from the fluid chamber, said gland means having a cylindrical body and a plurality of pressure members extending radially from its periphery;

surface means exterior of the bladder against which a substantial portion of the bladder side and bottom wall means are stretched for prestressing substantially the entire bladder wall means and causing a substantial portion of the interior surface of the bladder wall to be in surface-to-surface engagement with another portion of the interior surface of the bladder wall in the contracted position, whereby when in the contracted position, the bladder is substantially empty of fluid;

said surface means comprising an axially tapered elongate mandril exterior of the bladder fixed to the outer casing opposite the gland and extending interior of the casing toward the gland, said mandril being approximately centered with respect to the bladder and terminating in a free end near the gland, said free end having a diameter slightly less than the diameter of said bladder;

at least a portion of said bladder wall means being stretched around the mandril in the contracted position;

said gland means extending through the outlet of the bladder and terminating in an end closely conforming to the free end of the mandril;

the lower surface of the gland means being substantially the same shape as the mandril free end surface so that the free end surface of the mandril supports the gland means in an aligned position;

said bladder having an enlarged diameter portion adjacent its outlet with the portion of said bladder above said enlarged diameter section being folded down into contact with the bladder side wall, the fold being inserted between the gland body and the pressure members which extend radially therefrom; and

means for forcing said pressure members into engagement with said bladder for forming a fluid tight seal intermediate said bladder.