WO1995011769A1

WO1995011769A1 - Pressurized fluid dispenser for use in controlled adhesive application

Info

Publication number: WO1995011769A1
Application number: PCT/US1994/012435
Authority: WO
Inventors: Richard Salisbury
Original assignee: Richard Salisbury
Priority date: 1993-10-28
Filing date: 1994-10-28
Publication date: 1995-05-04
Also published as: AU8128894A

Abstract

A pressurized fluid dispenser for dispensing controlled quantities of cyanoacrylate adhesive has a generally hollow elongate body (10). A valve seat (22) is disposed within the body and a valve member (24) has a first position (Fig. 5) abutting the valve seat (22) such that pressurized fluid is prevented from flowing therethrough, and has a second position (Fig. 6) removed from the valve seat such that pressurized fluid flows therethrough. A tensioning spring (34) applies a biasing force to urge the valve member to its first position. A pressure acting surface (32) is formed upon the valve member such that pressure applied thereto by the pressurized fluid contained within the body urges the valve member toward the second position. A control fitting (72) mechanically linked to compression spring (44) controls the biasing force applied by the tensioning spring (34) to the valve member (24). Actuating the control lever (46) reduces the biasing force applied by the tensioning spring (34) to the valve member to the second position such that pressurized fluid is dispensed through the valve.

Description

PRESSURIZED FLUID DISPENSER FOR USE IN CONTROLLED ADHESIVE APPLICATION

Field of the Invention

The present invention relates generally to fluid dispensing devices and more particularly to a pressurized fluid dispenser for applying a controlled quantity of fluids such as cyanoacrylate adhesive or the like.

Background of the Invention Dispensers for applying controlled quantities of adhesiveε and the like such as cyanoacrylate adhesive are well known. Such pressurized fluid dispensers are commonly utilized in various manufacturing and assembly processes, such as the fabrication of printed circuits boards.

Cyanoacrylate adhesive is commonly utilized to secure circuit components in place upon printed circuit boards. For example, cyanoacrylate adhesive may be utilized to maintain the position of components prior to their being soldered to the printed circuit board. The use of cyanoacrylate adhesive thus improves the fabrication process for printed circuit boards, as well as many other products.

Such cyanoacrylate adhesive dispensers typically comprise an elongate handle or body which is held in a user's hand and is attached via a flexible hose to a source of pressurized cyanoacrylate adhesive. A control means, typically a lever or button disposed upon the body, facilitates dispensing of the cyanoacrylate adhesive through a needle attached to the outlet of the dispenser. Thus, minute, precisely controlled, quantities of cyanoacrylate adhesive may be dispensed and placed as desired.

Although such contemporary cyanoacrylate adhesive dispensers have proven generally suitable for their intended purposes, they possess inherent deficiencies which detract from their overall effectiveness in the arketplace. Such prior art devices typically utilize a valve requiring at least two to three pounds of force to seal properly. Thus, significant effort is generally required to overcome the sealing pressure of the valve and thus dispense cyanoacrylate adhesive from the device. Contemporary devices can require as much as five pounds of pressure in order to effect actuation thereof. The repeated use of such a pressurized fluid dispensing device for extended lengths of time is therefore tiring and uncomfortable.

Indeed, such repeated use may potentially cause carpel tunnel syndrome. As such, it would be beneficial to provide a valve mechanism requiring much less force to effect actuation thereof than contemporary devices. Additionally, cleaning of contemporary cyanoacrylate adhesive dispensers is typically necessary after short periods of non-use and is generally a difficult and time consuming process. Hardening of the cyanoacrylate adhesive can occur when exposed to air, thus complicating the cleaning process. As such, it would be beneficial to provide an easily cleaned pressurized fluid dispenser or alternatively one that has portions which are disposable such that cleaning is not required.

Because of the high cost of such devices, it is not economically feasible to dispose of contemporary cyanoacrylate adhesive dispensers. The cleaning of contemporary devices often requires at least partial disassembly thereof, and therefore is inconvenient and time consuming. The hardening of any cyanoacrylate adhesive disposed within the device substantially increases the difficulty and time required for cleaning the device.

As such, although the prior art has recognized to a limited extent the problem of dispensing cyanoacrylate adhesive in controlled quantities, the proposed solutions have to date been ineffective in providing a satisfactory remedy. Suπunary of the Invention

The present invention specifically addresses and alleviates the above-mentioned deficiencies associated with the prior art. More particularly, the present invention comprises a pressurized fluid dispenser for dispensing controlled quantities of fluids which is specifically adapted for use with modern adhesives such as cyanoacrylate adhesive and the like. It has a generally hollow elongate body wherein a valve seat is disposed within the body and a valve member has a first position abutting the valve seat such that pressurized fluid is prevented from flowing therethrough and a second position removed from the valve seat such that pressurized fluid flows therethrough. A tensioning means applies a biasing force to urge the valve member to its first position. A pressure acting surface is formed upon the valve member such that pressure applied thereto by the pressurized fluid contained within the body urges the valve member to the second position. Control means mechanically linked to the tensioning means controls the biasing force applied by the tensioning means to the valve member. Actuating the control means reduces the biasing force applied by the tensioning means to the valve member to allow the pressurized fluid to urge the valve member to the second position such that pressurized fluid is dispensed.

Although described as a pressurized fluid dispenser for dispensing cyanoacrylate adhesive and the like, those skilled in the art will recognize that the pressurized fluid dispenser of the present invention is likewise suitable for dispensing various other pressurized fluids. As such, disclosure of the pressurized fluid dispenser of the present invention as used with cyanoacrylate adhesive and the like is by way of illustration only and not by way of limitation. For the purposes of the present application, the term "adhesive" will be defined in its broader sense to include all fluids. The valve member of the pressurized fluid dispenser of the present invention preferably comprises a valve needle having proximal and distal ends, the distal end having the pressure acting surface formed thereon and abutting the valve seat. The needle valve comprises a bore formed longitudinally therein, the bore forming an inlet at the proximal end of the valve needle and forming at least one outlet proximate the distal end thereof.

A fluid reservoir is formed in the body at the distal end of the valve needle such that the valve needle is disposed within the reservoir. A plurality of spaced outlets are preferably formed in the valve needle and configured to spray fluid therefrom into said reservoir so as to evenly distribute solvent fed through the pressurized fluid dispensing device of the present invention in a manner which facilitates cleaning thereof. The outlets preferably comprise at least two diametrically opposed first outlets disposed at a first position along the valve needle and at least two diametrically opposed second outlets disposed at a second position, different from the first position, along the valve needle.

The control means preferably comprises a spool formed around the valve member and abutting the tensioning means and an actuating lever for causing the spool to move longitudinally within the housing so as to control the biasing force applied to the tensioning means.

The reservoir comprises a flexible bladder which isolates the pressurized fluid within the valve portion of the pressurized fluid dispenser by defining a flexible seal between the needle valve and the valve seat.

In a first embodiment of the present invention, the bladder and needle valve are formed as two separate components which are sealed together during assembly. Although either the bladder or the valve needle may be independently replaced as required, the flexible bladder is more subject to wear and will therefore generally be replaced without replacing the valve needle. The proximal end of the bladder is attached to the valve needle such that fluid can flow from the valve needle outlets into the flexible bladder and the distal end of the flexible bladder is attached to the body such that fluid can flow from the flexible bladder through the outlet of the body. The bladder is configured such that a portion thereof surrounds and seals against the valve seat.

In a second embodiment of the present invention, the bladder and needle are formed as a single, integral unit which may conveniently be replaced as an assembly. The needle valve is preferably formed of a more rigid material than the remainder of the bladder/needle valve assembly and may comprise such materials as rigid plastic or metal. Only the tip portion of the valve needle, i.e., that portion contacting the valve seat, need be fabricated from a more durable and rigid material than the remainder of the bladder/valve needle assembly.

Thus, in the second embodiment of the present invention, the bladder/valve needle assembly is replaced as a unit, thereby simplifying the removal and replacement process.

An adjustable stop formed upon the body limits movement of the actuating lever so as to provide for a preset flow rate of the pressurized fluid dispensed when the actuating lever is fully actuated.

The actuating lever has a first end contacting the spool and a second end movable by a user. The second end has a longer lever arm than the first end to mitigate the force required to actuate the actuation lever. The second end of the actuating lever is approximately between five and fifteen times, preferably approximately ten times, as long as the first end of the actuating lever. Thus, dispensing of the pressurized fluid can be controlled by applying a force of approximately one-half pound to the actuating lever, rather than applying as much as five pounds as required with contemporary devices.

These, as well as other advantages of the present invention will be more apparent from the following description and drawings. It is understood that changes in the specific structure shown and described may be made within the scope of the claims without departing from the spirit of the invention.

Brief Description of the Drawings

Figure 1 is a perspective view of a first embodiment of the pressurized fluid dispenser of the present invention showing how it is held by a user during use thereof; Figure 2 is an exploded perspective view of pressurized fluid dispenser of Figure 1;

Figure 3 is a cross-sectional side view of the pressurized fluid dispenser of Figure 1;

Figure 4 is a cross-sectional end view taken along lines 4 of Figure 3;

Figure 5 is a fragmentary enlarged cross-sectional side view of the valve needle and valve seat of Figure 3 showing the valve needle abutting the valve seat so as to prohibit dispensing of the pressurized fluid; Figure 6 is a fragmentary enlarged cross-sectional side view of the valve needle and valve seat of Figure 3 showing the valve needle disposed away from the valve seat so as to facilitate dispensing of the pressurized fluid. Figure 7 is a cross-sectional side view of the second embodiment of the pressurized fluid dispenser of the present invention; and

Figure 8 is a fragmentary enlarged cross-sectional side view of the bladder, valve needle, and valve seat of Figure 7 showing the valve needle disposed away from the valve seat so as to facilitate dispensing of the pressurized fluid. Detailed Description of the Preferred Embodiment

The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiment of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the functions and sequence of steps for constructing and operating the invention in connection with the illustrated embodiment. It is to be understood, however, that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.

The pressurized fluid dispenser of the present invention is illustrated in Figures 1-8 which depict two presently preferred embodiments of the invention. Referring now to Figures 1-6, the first embodiment of the pressurized fluid dispenser is comprised generally of an elongate generally hollow body 10 having a bore 12 formed longitudinally therethrough such that pressurized fluid is received at an inlet 14 at the proximal end 16 thereof and dispensed at an outlet 18 formed at the distal end 20 thereof, preferably via needle 21. Pressurized fluid such as cyanoacrylate adhesive or the like is supplied via flexible tube 23 attached at the inlet 14.

A valve seat 22 is disposed proximate the distal end 20 of the body 10 and cooperates with an elongate valve needle 24 having a preferably pointed, conical tip 25 and slidably disposed within the body bore 12 so as to control application of the pressurized fluid. When the needle valve 24 is disposed in a first position, abutting the valve seat 22, then the pressurized fluid is prevented from flowing and when the needle valve 24 is disposed in a second position, removed from the valve seat, then the pressurized fluid is permitted to flow. The valve needle 24 has a needle bore 26 formed longitudinally therein and also has the fluid inlet opening 27 formed at the proximal end thereof and at least one fluid outlet formed at the distal end thereof. The valve needle 24 preferably has two first diametrically opposed fluid outlets 28 formed at a first position and two diametrically opposed second fluid outlets 29 formed at a different, second position.

An abutment surface 30 is formed upon threaded fitting 62 disposed about the valve needle 24 intermediate the fluid inlet 14 and the fluid outlet 28. A pressure acting surface 32 is formed proximate the distal end of the valve needle 24, and preferably comprises the conical portion thereof.

A first compression spring 34 is disposed around the valve needle 24 such that the distal end of the first compression spring 34 abuts the abutment surface 30 so as to apply a biasing force to the valve needle 24 such that valve needle 24 is urged into abutment with valve seat 22.

A spool 36 is slidably disposed about the valve needle 24 such that the distal end of the spool 36 abuts the proximal end of the first compression spring 34. The spool 36 has a center portion 38, a distal end portion 40 and a proximal end portion 42. Flats 43 are formed upon the center portion 38. A bore 45 is configured to receive the valve needle 24. Flats 47 formed upon the interior of bore 45 slidably engage corresponding flats 51 formed upon the valve needle 24 so as to prevent rotation of the spool 36 about the valve needle 24. The center portion 38 has a smaller diameter than that of the first 40 and second 42 end portions. A cylindrical end portion 57 extends proximally from the proximal end portion 42.

A second compression spring 44 is disposed around the cylindrical end portion 57 of the valve needle 24 and abuts the spool 36 so as to urge the spool 36 distally. The proximal end of the second compression spring 44 abuts the abutment surface 73 of the threaded endpiece 72. Threaded endpiece 74 engages threads 75 formed near the proximal end of the valve needle 24 to capture the spool 36 or the valve needle 24.

A control lever 46 extends out from and generally parallel to the body 10. The control lever 46 has a first end 48, preferably comprised of first 71 and second 73 forked members, disposed intermediate the first 40 and second 42 end portions of the spool 36. The first 71 and second 72 forked members enter the body 10 through two slots 13 formed in the body 10. The first end 48 of the control lever 46 preferably has a bifurcated configuration wherein the center portion 38 of the spool

36 is disposed intermediate two forks 71 and 73 thereof.

The second end 50 of the control lever 46 extends distally generally parallel to the body 10 of the pressurized fluid dispenser of the present invention such that a user may grasp the body 10 thereof and use a finger, typically the index finger, to depress the distal end 50 of the control lever 46 so as to effect dispensing of the pressurized fluid. The first end 48 of the control lever 46 has a shorter lever arm than the second end 50 thereof to mitigate the force required to actuate the control lever 46. The lever arm of the second lever 46 is approximately five to fifteen times as long as the lever arm of the first lever 48 and is preferably approximately ten times as long.

The control lever 46 pivots about pivot pin 40 attached to body 10. Aperture 81 formed in upwardly extending boss 83 and corresponding aperture 85 formed in the first end 48 of the control lever 46 receive pivot pin 40 to facilitate rotation of the control lever 46 thereabout.

A flexible bladder 52 has a distal end 54 attached proximate the outlet 18 of the body 10 and also has a proximal end 56 attached to the valve needle 24 distal of the fluid outlets 28 formed in the valve needle 24. The valve seat 22 is received within the distal end 54 of the flexible bladder 52. The flexible bladder 52 flexes in response to sliding of the valve needle 24.

The flexible bladder 52 defines a pressurized fluid reservoir about the distal end of the valve needle 24 within the distal end of the body 10. The flexible bladder 52 comprises a distal cylindrical portion 91 area of reduced diameter 93, a reservoir portion 95 and a threaded portion 97. The distal cylindrical portion 91 extends into the outlet 18 of the pressurized fluid dispenser. The valve seat 22 is received within bore 90 of the distal cylindrical portion 91.

Threaded member 58 is threaded onto the distal end 20 of the body 10 so as to capture the valve seat 22 and urge the valve seat 22 proximally. The body 19 of valve seat 22 is slightly tapered, thus being fresco-conical in configuration so as to tighten against complimentary tapered portion 89 of the body 10, thus capturing the cylindrical portion 91 of the flexible bladder 52 therebetween. The portion of reduced diameter 93 receives the seat member 27 of the valve seat 22.

The body 95 of the flexible bladder 52 forms the reservoir into which pressurized fluid accumulates during the dispensing process. Threads 97 of the flexible bladder 52 engage complimentary threads 98 formed within threaded member 62. Threaded member 62 is disposed about tapered portion 99 formed upon valve needle 24. Threads 97 of the flexible bladder 52 are captured intermediate the threads 98 of the threaded member 62 and the tapered portion 99 of the valve needle 24.

Voids 47 formed proximate the valve seat 22 provide a space into which the region of reduced diameter 93 of the flexible bladder 52 stretch when the valve needle 24 moves proximally in response to depressing the control lever 46.

Thus, a fluid flow channel is formed through the flexible tubing 23, the bore 26 of the valve needle 24, -li¬ the first 28 and second 29 fluid outlets of the valve needle 24, the reservoir 53 defined by the flexible bladder 52, the bore 19 formed at the distal end 20 of the valve seat 22, and the needle 21. Threaded member 58 captures valve seat 22 within the body 10. Threads 100 of the valve seat 22 receive complimentary threads 101 of the needle 21 to attach the needle 21 to the fluid dispensing device.

Set screw or stop 64 is adjustable via aperture 66 formed in control lever 46 to varying the maximum displacement of control lever 46, thereby providing a means for presetting the maximum flow rate of dispensed pressurized fluid. Boss 104 surrounds set screw 64 to prevent inadvertent misadjustment thereof. The thickness of pad 68 formed upon the heel 70 of the control lever 46 determines the non-actuated or rest position of the control lever 46.

Fitting 72 is threadably disposed over the proximal end 16 of the body 10. The proximal end of the second compression spring 44 abuts abutment surface 73 of the fitting 72. The tension applied to the spool 36 by the second compression spring 44 is adjustable by varying the position of the threaded fitting 72 upon the proximal end 16 of the body 10, thus adjusting the pressure required for actuation of the pressurized fluid dispenser of the present invention by depressing the control lever 46. The force required to fully depress the control lever 46 and thereby effect full flow rate of the dispensed pressurized fluid is preferably adjusted to be approximately one-half pound.

Pressurized cyanoacrylate adhesive is provided to the pressurized fluid dispenser of the present invention via flexible tubing 23 from a pressurized container. Those skilled in the art will recognize that various fluid delivery systems are suitable for supplying the pressurized fluid to the fluid dispensing device of the present invention. Having thus described the structure of the pressurized fluid dispenser of the present invention, it may be beneficial to describe the operation thereof. Depressing the control lever 46 causes the first end 48 thereof to abut the proximal portion 42 of the spool 36, thus moving the spool 36 proximally to at least partially compress second compression spring 44.

With particular reference to Figures 5 and 6, proximal movement of the spool 36 reduces the biasing force supplied by the first compression spring 34 to the valve needle 24 such that the pressurized fluid disposed within the reservoir 53 defined by the flexible bladder 52 acts upon the pressure acting surface 32 of the valve needle 24 to cause the valve needle 24 to move away from its position abutting the valve seat 22 as illustrated in Figure 5 to the position separated from the valve seat 22 as illustrated in Figure 6, such that dispensing of the pressurized fluid is facilitated. When the valve needle 24 is moved proximally, away from the valve seat 22, fluid flows through the flexible tubing 23, and the bore 26 of the valve needle 24, exiting the valve needle 24 via first 28 and second 29 outlets into the reservoir 53. Fluid flows from the reservoir 53 through the bore 23 of the valve seat 22 and into the needle 21 from which it flows such that it may be applied as desired.

Releasing the control lever 46 allows second compression spring 44 to extend, thereby urging the spool 36 distally and increasing the pressure applied by the first compression spring 34 to the valve needle 24 so as to cause the valve needle 24 to overcome the pressure applied to the pressure acting surface 32 thereof and consequently to re-seat by abutting the valve seat 22. Distal movement of the spool 36 also urges the control lever 46 back to its original or non-actuated position. Movement of the valve needle 24 in a proximal direction results in deformation of the flexible bladder 52, particularly at the distal end of the reservoir portion 95 thereof. Voids 47 provide space into which the region of reduced diameter 93 of the flexible bladder 52 may stretch.

The substantially reduced actuation pressure of the control lever 46 permits prolonged and repeated usage of the pressurized fluid dispenser of the present invention without discomfort and without increasing the users potential for having carpel tunnel syndrome or similar disorders. The reduced actuation pressure is achieved by allowing the force of the pressurized fluid acting upon the pressure acting surface 32 of the valve needle 24 to actually move the valve needle 24 distally to effect dispensing of the pressurized fluid. The user merely reduces tension supplied by first compression spring 34 to the valve needle 24 in order to allow the pressure of the pressurized fluid to effect such movement of the valve needle 24. Also, a great mechanical advantage is provided by the extended length of the control lever 46, thus further reducing the effort required to effect dispensing of the pressurized fluid.

The maximum flow rate can easily be adjusted by inserting a screwdriver through aperture 66 formed in control lever 46 and varying the position of the stop or set screw 64. Turning the set screw 64 clockwise, i.e., deeper into the body 10, results in increased maximum travel of the control lever 46 and likewise results in an increased maximum fluid flow rate when the control lever 46 is fully depressed.

The user may vary the amount of fluid dispensed by the pressurized fluid dispenser of the present invention by varying the distance by which the control lever 46 is depressed. Partially depressing the control lever 46 results in a flow rate of dispensed fluid less than the maximum flow rate. Thus, precise control of the dispensed fluid is obtained in the present invention.

The pressure required to fully depress the control lever 46 and the pressure applied by the first compression spring 34 to the valve needle 24 to effect seating thereof is varied by changing the position, i.e., screwing in or out, of the threaded fitting 72 disposed at the proximal end of the body 10. Screwing the threaded fitting 72 in increases the pre-load compression of second compression spring 44, thereby similarly increasing the force required to fully depress the control lever 46. Since the force with which the second compression spring 44 is compressed is transmitted through the spool 36 to the first compression spring 34, varying the tension of the second compression spring 44 similarly varies the tension of the first compression spring 34. Conversely, screwing the threaded fitting 72 outward reduces the tension applied by the second compression spring 44 upon the spool 42, thereby decreasing the force required to fully depress the control lever 46, as well as the force required for the pressurized fluid to unseat the valve needle 24.

It should be noted that the threaded fitting 72 must be positioned so as to allow the second compression spring 4-4 to apply sufficient pressure to the spool 42 so as to consequently compress first compression spring 34 sufficiently to cause sufficient force to be applied to valve needle 24 to overcome the force applied by the pressurized fluid to the pressure acting surface 32 of the valve needle 24 such that the valve needle 24 remains abutted to the valve seat 22 when the control lever 46 is not depressed. Otherwise, leakage of the pressurized fluid from the needle 21 would occur. Although the pressurized fluid dispenser of the present invention is not prone to clogging due to hardening of the cyanoacrylate adhesive disposed therein, the fluid flow path of the device should nevertheless be cleaned prior to extended periods of non-use. The pressurized fluid dispenser is designed such that it may be efficiently and effectively cleansed by flushing with solvent. Pressurized solvent is introduced into the fluid inlet 14 and the control handle 46 is depressed such that solvent displaces the cyanoacrylate adhesive disposed along the flow path of the pressurized fluid dispenser. The outlets 28 and 29 formed in the distal end of the valve needle 24 are configured such that solvent will spray therefrom onto the interior surface of the bladder 52, thereby effectively cleaning the reservoir. After such flushing, the pressurized fluid dispenser of the present invention is ready for the reintroduction of cyanoacrylate adhesive at a later time.

Optionally, the working elements, i.e., the flexible bladder 52, valve needle 24, first 34 and second 44 compression springs and spool 36 may be configured for easy removal and disposal. That is, these components may optionally be formed of low-cost materials and be configured for easy removal and replacement. Thus, rather than cleaning these elements, they may simply be removed from the body 10, disposed of, and replaced with corresponding new elements. A pressurized or removable fluid dispenser utilizing such disposable or removable elements may also be optionally cleaned as desired. Indeed, such easy removal thereof facilitates cleaning by providing easy access to the working components of the pressurized fluid dispenser whether they are configured to be disposable or not.

Referring now to Figures 7 and 8, the second embodiment of the pressurized fluid and dispenser of the present invention will be described with particular emphasis upon the differences between the second embodiment and the first embodiment. As in the first embodiment of the present invention, the second embodiment thereof generally comprises an elongate generally hollow body 210 having a bore 212 formed longitudinally therethrough such that pressurized fluid is received at an inlet 214 at the proximal end 216 thereof and dispensed at an outlet 218 formed at the distal end 220 thereof, preferably via needle 221. A handle or control lever 246 extends from the body 210 and is depressed to facilitate control of the dispensing of pressurized fluid as in the first embodiment of the present invention. In the second embodiment of the present invention the body 210 comprises a distal cap 211 threaded to the distal end thereof so as to provide access to the bore 212, thereby readily facilitating removal and replacement of those components disposed therein. The valve seat 222 is preferably disposed within the distal end cap 211.

The valve seat 222 cooperates with a valve needle 224 as in the first embodiment of the present invention so as to control dispensing of the pressurized fluid. However, in the second embodiment of the present invention the valve needle 224 is formed to the flexible bladder 252 so as to permit easy removal and replacement of a bladder/valve needle assembly defined by the bladder 252 and the valve needle 224. Thus, the bladder/valve needle assembly may be removed from the body 210 by simply unthreading or removing the distal end cap 211 from the body and pulling the bladder/valve needle assembly therefrom after the pressurized fluid dispenser has been disconnected from the inlet lines or flexible tube (23 of Figure 1). In the second embodiment of the present invention, the valve needle 224 comprises a valve needle head 221 upon which the pressure acting surface 225 is formed and which contacts the valve seat 222. The valve needle head 221 contains a plurality of fluid outlets 228 and also has a bore 229 formed at the proximal end thereof. The bore 229 of the valve needle head 221 receives the distal end of the valve needle body 231 via a press fit, thus attaching the valve needle head 221 to the valve body 231. Those skilled in the art will recognize that various means, i.e., adhesive bonding, ultrasonic welding, etc., for assuring attachment of the valve head 221 to the valve needle body 231 are suitable. As in the first embodiment of the present invention, the flexible body 252 utilizes flexible or living hinges 256 to accommodate flexing thereof when the valve needle head 221 is retracted away from the valve seat 222. The first spring 234 is captured intermediate an abutment surface 230 formed upon the valve needle body 231 and a spool 236. The first compression spring 234 applies pressure to the valve needle body 231 through the abutment surface 230 thereof so as to cause the valve needle head 221 to abut the valve seat 222, thus inhibiting flow of pressurized fluid from the pressurized fluid dispenser. A second compression spring 244 provides a counterbalancing and adjustable force which is applied to the spool 236 so as to determine or preset the amount of force required to effect actuation of the pressurized fluid dispenser of the present invention, as in the first embodiment thereof.

Nut 217 is threaded upon the valve needle body 231 and abuts the spool to which the valve body 231 is likewise threadably attached.

The second embodiment of the fluid dispensing device of the present invention operates in a manner similar to that of the first embodiment thereof, with the exception that the reduction in force applied by the first compression spring 234 is applied directly to the valve needle body 231 through the abutment surface 230 formed thereon, rather than through a separate abutment surface threaded thereto. Operation of the second embodiment of the present invention is otherwise analogous to that of the first embodiment thereof.

Maintenance of the second embodiment of the present invention is simplified as compared to the first embodiment since the entire bladder/valve needle assembly may easily be removed from the body 210 by simply removing the distal end cap 211 from the body 210 and pulling the bladder/valve needle assembly from the body 210. The proximal end of the valve needle 231 must first be disconnected from any interconnecting tubing, such as the fluid supply flexible tubing 23 (Figure 1).

It is understood that the exemplary pressurized fluid dispenser described herein and shown in the drawings shows only a presently preferred embodiment of the invention. Indeed, various modifications and additions may be made to such embodiment without departing from the spirit and scope of the invention. For example, the pressure acting surface may assume various configurations wherein the pressure from the reservoir acts thereupon to effect movement of the valve needle away from the valve seat. Also, various means, i.e., spring means, resilient means, pressure means, etc., may be utilized to effect biasing of the valve needle into abutting contact with the valve seat. Thus, these and other modifications and additions obvious to those skilled in the art may be implemented to adapt the present invention for a variety of different applications.

Claims

WHAT IS CLAIMED IS:

1. A pressurized fluid dispenser comprising: a) a generally hollow elongate body; b) a valve seat disposed within said body; c) a valve member having a first position abutting said valve seat such that pressurized fluid is prevented from flowing therethrough and having a second position removed from said valve seat such that pressurized fluid flows therethrough; d) tensioning means for applying a biasing force to urge said valve member to the first position; e) pressure acting surface formed upon said valve member such that pressure applied thereto by the pressurized fluid urges said valve member to the second position; f) control means linked to said tensioning means to control the biasing force applied by said tensioning means to said valve member; g) wherein actuating the control means reduces the biasing force applied by said tensioning means to said valve member to allow the pressurized fluid to urge said valve member from the first position to the second position such that pressurized fluid is dispensed.

2. The pressurized fluid dispenser as recited in Claim 1 wherein said valve member comprises a valve needle having proximal and distal ends, the distal end having the pressure acting surface formed thereon and abutting said valve seat.

3. The pressurized fluid dispenser as recited in Claim 2 wherein said valve needle comprises a bore formed longitudinally therein, said bore forming an inlet at the proximal end of said valve needle and said bore forming at least one outlet proximate the distal end of said valve needle.

4. The pressurized fluid dispenser as recited in Claim 2 further comprising a fluid reservoir formed in said body about the distal end of said valve needle.

5. The pressurized fluid dispenser as recited in Claim 3 wherein said at least one outlet formed in said valve needle comprises a plurality of spaced outlets configured to spray fluid therefrom into said reservoir.

6. The pressurized fluid dispenser as recited in Claim 3 wherein said at least one outlet formed in said valve needle comprises: a) two diametrically opposed first outlets disposed at a first position along said valve needle; and b) two diametrically opposed second outlets disposed at second position, different from the first position, along said valve needle.

7. The pressurized fluid dispenser as recited in Claim 1 wherein said control means comprises: a) a spool formed around said valve member and abutting said tensioning means; b) a control lever for causing said spool to move longitudinally within the housing so as to control the biasing force applied to said valve members by said tensioning means.

8. The pressurized fluid dispenser as recited in Claim 7 further comprising an adjustable stop for limiting the movement of said control lever so as to preset the flow rate of pressurized fluid dispensed when said control lever is fully activated.

9. The pressurized fluid dispenser as recited in Claim 4 wherein said fluid reservoir comprises a flexible bladder, the proximal end of said bladder being attached to said valve needle and the distal end of said flexible bladder being attached to said body.

10. The pressurized fluid dispenser as recited in Claim 7 wherein said control lever has a first end contacting said spool and a second end movable by a user, said second end having longer lever arm than said first end to mitigate the force required to actuate said control lever.

11. The pressurized fluid dispenser as recited in Claim 9 wherein the lever arm of said second end of said control lever is between approximately 5 and approximately 15 times as long as the lever arm of said first end of said control lever.

12. The pressurized fluid dispenser as recited in Claim 9 wherein the lever arm of said second end of said control lever is approximately ten times as long as the lever arm of said first end of said control lever.

13. The pressurized fluid dispenser as recited in Claim 1 wherein said tensioning means comprises at least one compression spring.

14. The pressurized fluid dispenser as recited in Claim 2 wherein said pressure acting surface comprises a generally conical surface formed at the distal tip of said valve needle.

15. The pressurized fluid dispenser as recited in Claim 1 wherein the biasing force applied by said tensioning means to said valve member is adjustable.

16. The pressurized fluid dispenser as recited in Claim 7 wherein said valve needle, said spool, and said tensioning means are disposable.

17. The pressurized fluid dispenser as recited in Claim 1 further comprising a needle disposed at the distal end of said body through which the pressurized fluid is dispensed.

18. The pressurized fluid dispenser as recited in Claim 9 wherein said flexible bladder and said valve needle are formed as an integral unit so as to facilitate easy removal and replacement thereof.

19. The pressurized fluid dispenser as recited in Claim 18 wherein said valve needle comprises: a. a valve needle body formed of the same material as said flexible bladder; and b. a valve needle head formed of a more rigid material than said flexible body.