US3854631A

US3854631A - Automatic dispenser for hot fluids under pressure

Info

Publication number: US3854631A
Application number: US00357501A
Authority: US
Inventors: L Moen
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-05-04
Filing date: 1973-05-04
Publication date: 1974-12-17
Anticipated expiration: 1991-12-17

Abstract

A heated dispenser body internally contains a retainer for a tubular actuator that is mounted for pivotal movement about an axis that is parallel to a plane intersecting an adjustable nozzle on the free end of the actuator. The nozzle houses a valve seat that is normally closed by a valve head formed on the forward end of an elongate stem that has an rear end flange biased against a forward end of a hollow spool that is axially slidably mounted in the housing. A biasing means normally maintains the valve head in a closed position on the valve seat. Upon deflection of the nozzle by an article moving in the aforementioned plane, the actuator is rocked about its axis whereby the flange of the actuator cams the spool rearwardly to effect withdrawal of the valve head from its seat to permit a hot liquid under pressure to be expelled from an orifice in the nozzle. The rear end of the body is closed by a flow adjusting plug whose normal clearance relative to the spool can be externally adjusted as desired to positively limit the range of possible axial travel by the spool and, correspondingly, throttle the valve opening to a desired degree. The retainer is formed with a central passage having an annular pocket containing an O-ring, on a back-up ring, in fluid sealing engagement with the actuator. The relationship of the O-ring and the pivot axis of the actuator is such that the median diametral plane of the O-ring is in the plane of the pivot axis.

Description

[451 Dec. 17, 1974 United States Patent [191 Moen [5 AUTOMATIC DISPENSER FOR HOT tersecting an adjustable nozzle on the free end of the FLUIDS UNDER PRESSURE actuator. The nozzle houses a valve seat that is normally closed by a valve head formed on the forward [76] Inventor tfgsgi i gg g Michigan end of an elongate stem that has an rear end flange bi- May 4, 1973 Appl. No.: 357,501

ased against a forward end of a hollow spool that is ax- [22] Filed: ially slidably mounted in the housing. A biasing means normally maintains the valve head in a closed position on the valve seat. Upon deflection of the nozzle by an article moving in the aforementioned plane, the actuator is rocked about its axis whereby the flange of the actuator cams the spool rearwardly to effect withdrawal of the valve head from its seat to permit a hot Int. B67d 5/62 liquid under pressure to be expelled from an orifice in the nozzle. The rear end of the body is closed by a flow adjusting plug whose normal clearance relative to 003 1 2 06 0 2 6. 32m 10/ ,4l E 0 HUN 1 2 0 2 ,4 00 n0 5 n 6 w 2 2 2 M .n F N 5 the spool can be externally adjusted as desired to positively limit the range of possible axial travel by the spool and, correspondingly, throttle the valve opening to a desired degree.

3,198,394 8/1965 Lefer 3,482,737 12/1969 Marder et al...

3,642,173 2/1972 Marraffino.,...........,....... 222/402.24 The tainer is formed with a central passage having an annular pocket containing an O-ring, on a back-up Primary ExaminerStanley H. ll rg ring, in fluid sealing engagement with the actuator.

A n y, g Firm-Frederick Mueller The relationship of the O-ring and the pivot axis of the actuator is such that the median diametral plane of the O-ring is in the plane of the pivot axis.

[57] ABSTRACT A heated dispenser body internally contains a retainer for a tubular actuator that is mounted for pivotal movement about an axis that is parallel to a plane inl7 Claims, 8 Drawing Figures AUTOMATIC DISPENSER FOR HOT FLUIDS UNDER PRESSURE BACKGROUND OF THE INVENTION The present invention relates generally to dispensers for fluids and, more particularly, to automatic dispensers for hot liquids under pressure. The invention appears to have its primary utility as a hot glue applicator for paper or cardboard box forming machines, e.g., Bliss box machines. Accordingly it will be specifically described with respect to that field, by way of illustration but not limitation.

'The use of hot and cold glue applicators in machines for forming cardboard containers from container blanks is noted in my U.S. Pat. No. 3,273,757 of Sept. 20, 1966. The patent discloses a dispenser that is adapted primarily for the application of cold glue and has been highly successful with such material. However, problems have been encountered in attempts to use the cold glue applicator of the patent to dispense hot glues.

More particularly, hot glues are typically applied at pressures up to 500 psig and temperatures up to 420F. The patented dispenser employs a tubular actuator barrel having a ball-like rear end that is swivelly mounted in a supporting body and biased against an O-ring providing a fluid seal between the external surface of the enlarged ball end and an annular shoulder of the body which seats the O-ring. In order to accommodate the swiveling movement of the actuator barrel, the opening in the body through which the barrel extends is relatively large, as compared to the cylindrical surface of the barrel, to provide the necessary clearance. However, when subjected to hot glue under pressure it has been found that in the patented dispenser the O-ring seal very quickly is extruded through the large clearance space, whereby the seal is lost. Further, due to the high fluid pressures involved, the ball head of the actuator barrel is so firmly seated against the O-ring that an excessive actuating pressure from an article to which glue is to be applied is required at the nozzle end of the barrel.

SUMMARY OF THE INVENTION In a presently preferred embodiment of this invention a heated body is provided with a port for the connection of a conduit means in communication with a supply of hot glue under pressure. Internally, the body supports a spool for axial slidable reciprocation between positive limits imposed by a flow adjusting plug, closing the rear end of the body, and a retainer and actuator assembly, closing the forward end of the body. The hollow spool is provided with an external circumferential groove defining an annulus with the inner wall of the body in fluid communication with the hot glue port. A forward or lower end wall of the spool is slotted to provide passage means for the hot glue to flow forwardly through an actuator barrel. A retainer in the forward end of the body is formed with a central axial passage therethrough to receive the actuator barrel. Adjacent its rear or inner end this passage is provided with an annular groove mounting an O-ring on a back-up ring, the former providing a fluid seal between the external surface of the actuator barrel and the surrounding wall of the passage through the retainer. At its innermost end the actuator barrel has a radially outwardly extending flange that is mounted on a wear ring which, in turn, is

pivotally rockable on a diametrically opposite pair of pivot pins secured to the rear face of the retainer. The pivot pins are positioned to define a pivot axis for the wear ring which is in the same plane as the median diametral plane of the O-ring for the actuator barrel.

An axially adjustable nozzle is mounted on the free forward end of the actuator barrel and internally mounts a valve seat means around an orifice formed through the nozzle. An elongate valve stem within the barrel is formed with a valve head at its forward end and, at its rear or innermost end, the stem is normally biased into seating engagement with the inside of the forward wall of the spool, to effect closing of the valve port. Upon an article, such as a container blank, coming into engagment with the nozzle, the actuator barrel is pivoted about the pivot pins, whereby the flange of the actuator earns the spool rearwardly relative to the body to thereby withdraw the head of the valve stem from the seat, thus allowing the hot glue to be expelled through the nozzle orifice.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partial, vertical sectional view of a presently preferred embodiment of the invention as mounted in operative position on a box forming machine;

FIG. 2 is an axial sectional view, on a larger scale, of the hot glue dispenser shown in FIG. 1, taken on the line 2--2 of FIG. 1;

FIG. 3 is a view similar to FIG. 2 but with the internal parts shown displaced out of normal position to a condition in which the valve of the device is open;

FIG. 4 is a transverse cross sectional view, taken on the line 4-4 of FIG. 2, to illustrate the pivot pins for the actuator assembly;

FIG. 5 is a perspective view of the spool;

FIG. 6 is a lower end elevational view of the spool of FIG. 5; I

FIG. 7 is a transverse cross sectional view taken on the line 7-7 of FIG. 2;

FIG. 8 is a perspective view of an O-ring back-up member, with a portion thereof being cut away to better illustrate the radial cross sectional configuration thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a box forming machine'is generally indicated by the numeral 10, illustrating one field of use of the dispenser of this invention. Typically, such a machine includes a framework made up of a plurality of cross members 11, side member 12, and columnar members or legs 13 to provide a rigid support for a parallel pair of angle-iron box blank guide members 14. On both sides of the machine 10 one or more upstanding brackets 15 are rigidly secured thereto to support one or more hot glue dispensers in a fixedly adjusted position to apply a stripe of glue to a margin or flap of each of a series of box blanks fed along the guide members 14. In the illustrated case, the presently preferred embodiment of hot glue dispenser is indicated generally by the numeral l8 and, by way of illustration, is held in place within a mounting ring 19 by a screw member 20. The ring 19 is, in turn, fixedly secured to a horizontally extending support rod 21 that extends through a sleeve 22 secured to the upper end of the bracket 15 and in which sleeve the rod is clamped by a suitable screw fastener 23. It will, of course, be understood that the illustrated mounting means for the dispenser 18 is merely illustrative of a wide variety of such means which may be employed to fixedly secure the dispenser in a desired inclined relationship relative to the box blanks 16 proceeding through the machine 10.

In order to maintain the hot glue at a desired temperature the dispenser has a heated body. This may, for example, take the form of a cylindrical body that is wound with an electrical heating coil 26, the wall of the body being formed with a port 27 to which a suitable conduit means 28 can be connected to provide fluid communication of the interior of the body with a source of hot glue under pressure.

The rear end of the body 25 is closed by a plug 30, the two parts being threadedly interconnected as indicated at 31. The plug 30 is formed with a slightly enlarged head 32 having wrench flats by means of which the plug can be adjusted axially relative to the body 25, as a means of adjusting the rate of flow of the hot pressurized fluid out of the dispenser. In order to provide a fluid seal, the inner end of the plug 30 is formed with a circumferential groove 33 providing a pocket for an O-ring 34 that is in fluid-sealing engagement with the interior of the body 25.

The forward end of the body 25 mounts an actuator retainer 35, the two parts being threadedly innerconnected as indicated at 36. The forward, outer end of the retainer 35 has a slightly enlarged head 37 that is also formed with wrench flats, whereby the retainer 35 can be adjusted axially relative to the body 25. In order to provide a fluid seal between the two parts, the rear inner end of the retainer 35 is formed with a circumferentially extending groove 38 providing a pocket for an O-ring seal 39.

The retainer 35, at its inner end, is externally formed with an annular shoulder 40 and, as is best seen in FIG. 4, a coaxially aligned pair of pivot pins 41 are affixed thereto to protrude from the radial surface of the shoulder. The pivot means may take a variety of forms but, preferably, the radial surface of the shoulder 40 is formed with semi-circular notches of a radius to matingly receive the short, cylindrical cross section pivot pins 41 and of a depth to leave semicylindrical sections of the pins exposed, after the pins have been soldered or otherwise affixed in place on the retainer 35. The pair of pins 41 rockably support a wear ring 42 which in turn acts as a seat for a radially outwardly extending flange 43 that is integrally formed on the rear end of a tubular actuator barrel 44. As is indicated in the drawing, in FIGS. 2 and 3, the external diameters of the wear ring and flange 43 are sufficiently smaller than the internal diameter of the body 25 to provide clearance for the rocking action of these two elements about the pivot axis defined by the pivot pins 41. For the same reason the inner diameter of the wear ring 42 is larger than the axially extending cylindrical surface of the shoulder 40.

The actuator barrel 44 extends through a tapered passage 45 formed axially through the retainer 35. Adjacent the smaller rear end of the passage 45 the wall thereof is formed with an annular pocket 46 which, at its axially forward end, mounts back-up ring 47 on which an O-ring 48 is seated. As is shown in FIG. 8, the retainer ring 47 is formed with a concave rear face to matingly receive a portion of one side of the O-ring 48 and the inner edge 49 of the ring 47 is preferably formed with a taper that is a continuation of the taper of a retainer passage 45 and of a maximum diameter to provide a slight clearance to permit ready deflection of the actuator barrel 44. The O-ring 48 provides a fluid seal between the retainer 35 and the external surface of the actuator barrel 44 and the back-up ring 47, which is preferably made of a relatively hard material such as Teflon, prevents extrusion of the O-ring through the clearance between the external surface of the actuator barrel 44 and the surrounding wall portion of the passage 45.

When the dispenser 18 is mounted in operative position, as in FIG. 1, the axis defined by the pivot pins 4] should be disposed parallel to the plane in which the box blanks 16 travel and normal to the direction of travel of the blanks. Accordingly, in oder to provide an external indicator of the position of the pivot pins 41, the retainer 45, on its forward end face, is provided with a diametrically opposite pair of indicator grooves 50 that are parallel to the pivot pins 41. See FIG. I.

The lower end of the actuator barrel 44 is interiorly threaded to receive the threaded shank of a nozzle 51. In order to provide a fluid seal between the nozzle 51 and barrel 44 the shank of the former is formed with a circumferential groove 52 to receive an O-ring seal 53. The nozzle is of hemispherical configuration at its lower end and is formed with an axially extending orifice 54 through which the hot liquid is exhausted.

Flow through the orifice 54 is controlled by a valve means that is operable to open the flow passage upon deflection of the actuator assembly by an article coming into contact with the nozzle 51. Thus, the noxxle 51 is counterbored through the rear end thereof to define a passage 55 that is coaxially related to the orifice 54 and to form a shoulder on which an annular valve seat.

56 is mounted. An elongate valve stem 57 is formed with a reduced diameter forward end that extends, with clearance, into the nozzle passage 55 and terminates at its forward end in a valve head 58 that is adapted to close the valve opening of the seat 56 when the head 58 is seated thereon. As is indicated in FIG. 7, the side of the valve head 58 is formed with a plurality of flats 59 to provide clearance for the flow of the fluid being dispensed therealong when the valve head 58 is in an open position, as in FIG. 4.

In order to effect opening of the valve upon deflection of the actuator assembly, the rear end of the valve stem 57 is operatively interconnected to a hollow spool 60 that is mounted within the body 25 between the opposing end faces of the plug 30 and retainer 35. Thus, the rear end of the valve stem 57 is externally threaded to mount a lock nut 61 which bears against a concentric washer 62 that in turn bears against the inside of a forward end wall 63 of the spool 60. As is indicated in FIGS. 2 and 3, the outer diameter of the washer 62 is sufficiently smaller than the internal diameter of the spool 60 to provide sufficient clearance to prevent binding between the parts upon actuation of the valve. Similar clearances are provided between the inner edge of the washer 62 and an inner edge of an opening 64 in the end wall 63 of the spool 60, relative to the valve stem 57. A spring means, e.g., a partially volute coil spring 65, is housed within the spool 60 having its rear end biased against the plug 30 and its forward end biased on the lock nut 61 to normally hold the spool against the rear end of the actuator assembly.

As is best seen in FIG. 5, the spool 60 is preferably made out of a piece of hexagonal bar stock which is machined to define a shallow, axially elongate cylindrical section 66 between opposite end

hexagonal portions

67 and 68. The corners of the

hexagonal portions

67 and 68 are further machined to round off the corners between adjacent flats on a diameter for mounting the spool 60 in a close, axially slideable fit within the body 25. Referring to FIGS. 2 and 3, there is thus defined an annular space between the spool 60 and the inner wall of the body 25 in fluid communication with the hot fluid port 27. Adjacent its forward end the spool 60 is formed with a diametrically opposite pair of ports 70 through the side wall of the spool and through the front end wall 63 to allow fluids to more freely enter the actuator barrel 44. As is indicated in FIGS. 2 and 3, the rear end face of the flange 43 of the actuator barrel is formed into a shallow frusto-conical surface 71 providing a relief to ensure the free passage of the hot fluid into the actuator barrel.

With the just described configuration of spool 60 the area of mutual contact between the spool 60 and the body 25 is minimized in order to minimize frictional resistance to axial reciprocation of the spool in the body while, at the same time, the spool 60 is positively constrained for such axial reciprocation. As the high pressure fluid acts on both of the opposite sides of the actuator flange 43 the pressure of the fluid does not significantly inhibit deflection of the actuator barrel 44 in response to an object striking the nozzle 51. As contrasted to a ball joint, the pivot pins 41 provide a very low friction bearing for deflection of the actuator barrel. At the same time, the coplanar relationship of the median plane of the O-ring 48 and pivot axis of the pins 41, at the narrow neck of the retainer passage 45, minimizes the extent to which the O-ring must be radially compressed to accommodate angular deflection of the actuator barrel. With this combination of features, despite the presence of very high pressure fluid forces, the valve mechanism is responsive to very light actuating pressures, whereby opening and closing of the exhaust valve can be very precisely controlled.

As is shown in FIG. 2, when the dispenser valve is in the closed position a slight clearance exists between the rear face of the spool 60 and the forward face of the plug 30. The extent of this space can be adjusted as desired by adjusting the position of the plug 30 relative to the body 25, by screwing the plug inwardly or outwardly to the desired extent. With this arrangement, an external means is provided to adjust the flow rate of the hot fluid out of the orifice 58 in the nozzle 51, corresponding to the degree to which the valve head 58 is allowed to withdraw from the valve seat 56.

As is indicated in FIG. 2, the dispenser 18 is adapted to be mounted at an angle of approximately 20 to the vertical with the nozzle 51 protruding beneath the lowermost edge of the retainer head 37 to intercept the leading edge of a container blank 16 proceeding along the guide rails 14. As previously indicated, the dispenser 18 should be so oriented that the axis of the pivot pins 41 is parallel to the plane of travel of the box blanks l6 and normal to the direction of travel.

Referring to FIG. 3, upon the leading edge of a container blank 16 coming into contact with the nozzle 51 the actuator barrel is pivoted through a small are about the axis of the pivot pins 41. The actuator flange 43 is thus moved through a corresponding arc and, as the spool is constrained for purely axial translatory movement by the body 25, the spool is accordingly cammed rearwardly relative to the body. As a result of this camming action the valve stem 57 is axially rearwardly withdrawn to the extent permitted by abutment of the rear end of the spool 60 with the forward face of the plug 30 to deliver the hot liquid under pressure, at a desired rate, through the orifice 58 to be deposited onto the container blank 16. As will be apparent, when the trailing edge of the blank 16 leaves contact with the nozzle 51 the parts are restored to the closed position illustrated in FIG. 2 by the spring and the piston effect of the spool 60.

While a specific embodiment of the invention has been described and illustrated, it is intended to be purely illustrative and not limitative of the invention.

What is claimed is:

1. In an automatic high pressure fluid dispenser the improvement comprising:

a dispenser body having an interior chamber for containing a fluid under high pressure;

an actuator retainer affixed within said body and having a passage for mounting an acutator therethrough;

an actuator having a tubular barrel extending through said passage of said container with clearance therebetween;

pivot means, interconnecting a rear inner end of said retainer and a rear inner end of said actuator, comprising rigid, opposed portions of said retainer and said actuator that are biased into pivotal abutment for pivotal movement of said actuator relative to said retainer and body about an axis that is normal to and intersects the longitudinal axis of said passage of said retainer;

and an endless fluid seal means in said clearance intermediate said passage of said retainer and the exterior of said barrel, said seal means and said pivot axis being positioned in substantially a common plane comprising the median plane of said seal means, the coplanar relationship of said axis and said median plane of said seal means, minimizing radial compression of said seal means in response to pivotal deflection of said actuator.

2. A dispenser as in claim 1 in which said passage of said retainer is formed with an annular pocket and said seal means comprsies an O-ring in said pocket.

3. A dispenser as in claim 2 in which said pocket also mounts a back-up ring for said O-ring at an axially forward end of said pocket, the axially rearwardly facing surface of said ring being concave in radial cross section to define a complementary seat for said O-ring.

4. A dispenser as in claim 1 in which said pivot means comprises an external annular shoulder on said rear inner end of said retainer mounting a diametrically opposite pair of bearings on which said rear inner end of said actuator pivots.

5. An actuator as in claim 4 in which said rear inner end of said actuator is formed with a radially outwardly extending flange overlying said shoulder of said retainer.

6. A dispenser as in claim 5 in which said bearings comprise a pair of coaxially aligned pivot pins secured to a radially extending surface of said shoulder and rockably engaged by a ring that is interposed between said flange of said actuator and said pins.

7. A dispenser as in claim 1 that is externally marked with indicators that are parallel to said pivot axis.

8. An externally adjustable automatic fluid dispenser comprising:

a dispenser body having a port means for communicating the interior of said body with a source of fluid under high pressure;

an actuator retainer affixed within said body and having a passage for mounting an actuator therethrough;

an actuator having a rear inner end pivotally interconnected to a rear inner end of said retainer and having an actuator barrel extending forwardly through said passage to protrude forwardly beyond forward ends of said retainer and of said body;

a nozzle mounted on the forward protruding end of said barrel and formed with an outlet orifice therethrough;

an elongate valve member extending coaxially within said barrel and having a valve head at its forward end for normally closing a valve seat around said orifice;

a spool mounted in the interior of said body for slidable axial reciprocation and having a forward end coupled to a rear end of said valve member for withdrawing said valve head from said valve seat upon axially rearward movement of said spool;

means intermediate said spool and said actuator for translating lateral deflection of said barrel into axially rearward movement of said spool to effect opening movement of said valve member;

and externally adjustable rigid means in said body to selectively positively limit the range of rearward axial movement of said spool to correspondingly limit opening movement of said valve member.

9. A dispenser as in claim 8 in which said last mentioned means comprises a plug that is threadedly engaged with said body to effect adjustment of said spool axially relative to said retainer.

10. A dispenser as in claim 9 in which said spool comprises a hollow member that is normally biased forwardly against a flanged rear end of said actuator by a means that also normally biases said valve member axially forwardly to a closed positon of said valve head on said valve seat.

11. An automatic fluid dispenser comprising:

a dispenser body;

a spool mounted in said body for slidable axial reciprocation between positively fixed limits;

an actuator mounted in said body for pivotal movement about a single axis;

said actuator including a tubular barrel having a forward end that protrudes forwardly beyond a forward end of said body to terminate in a nozzle that is laterally deflectable to effect pivotal movement of said actuator barrel about said single axis;

means intermediate a forward end of said spool and a rear inner end of said actuator to translate angular pivotal deflection of said barrel into axial rearward movement of said spool;

and a valve means in said barrel that is operatively coupled to said spool to effect opening and closing of said valve member in response to axial movement of said spool between said fixed limits to control flow of fluids through an orifice in said nozzle.

12. A dispenser as in claim 11 in which said spool comprises a hollow member that is normally biased forwardly against a flanged rear end of said actuator by a means that also normally biases said valve means to a closed position.

13. A dispenser as in claim 11 that includes an actuator retainer and an adjustable plug that are coaxially related to define said positively fixed limits for slidable axial reciprocation of said spool, said plug being externally adjustable to limit the range of rearward axial movement of said spool to correspondingly limit opening movement of said valve means.

14. A dispenser as in claim 11 in which said valve means comprises an elongate valve member extending coaxially through said barrel and having a valve head at its forward end for normally closing a valve seat around said orifice.

15. A dispenser as in claim 14 in which said means to translate deflection of said barrel into rearward movement of said spool comprises a diametrically opposite pair of pivot bearings on said actuator that are rockably engaged by a radially outwardly extending flange on a rear inner end of said actuator.

16. A dispenser as in claim 11 in which said body has an actuator retainer affixed thereto having a passage for mounting said actuator and in which an endless fluid seal means is disposed intermediate said passage of said retainer and the exterior of said actuator barrel, said seal means and said pivot axis being positioned in substantially a common plane.

17. A dispenser as in claim 16 in which said passage of said retainer is formed with an annular pocket and said seal means comprsies an O-ring in said pocket;

said pocket also mounting a back-up ring for said O- ring at an axially forward end of said pocket, the axially rearwardly facing surface of said back-up ring being concave in radial cross section to define a complementary seat for said O-ring.

Claims

1. In an automatic high pressure fluid dispenser the improvement comprising: a dispenser body having an interior chamber for containing a fluid under high pressure; an actuator retainer affixed within said body and having a passage for mounting an acutator therethrough; an actuator having a tubular barrel extending through said passage of said container with clearance therebetween; pivot means, interconnecting a rear inner end of said retainer and a rear inner end of said actuator, comprising rigid, opposed portions of said retainer and said actuator that are biased into pivotal abutment for pivotal movement of said actuator relative to said retainer and body about an axis that is normal to and intersects the longitudinal axis of said passage of said retainer; and an endless fluid seal means in said clearance intermediate said passage of said retainer and the exterior of said barrel, said seal means and said pivot axis being positioned in substantially a common plane comprising the median plane of said seal means, the coplanar relationship of said axis and said median plane of said seal means, minimizing radial compression of said seal means in response to pivotal deflection of said actuator.

8. An externally adjustable automatic fluid dispenser comprising: a dispenser body having a port means for communicating the interior of said body with a source of fluid under high pressure; an actuator retainer affixed within said body and having a passage for mounting an actuator therethrough; an actuator having a rear inner end pivotally interconnected to a rear inner end of said retainer and having an actuator barrel extending forwardly through said passage to protrude forwardly beyond forward ends of said retainer and of said body; a nozzle mounted on the forward protruding end of said barrel and formed with an outlet orifice therethrough; an elongate valve member extending coaxially within said barrel and having a valve head at its forward end for normally closing a valve seat around said orifice; a spool mounted in the interior of said body for slidable axial reciprocation and having a forward end coupled to a rear end of said valve member for withdrawing said valve head from said valve seat upon axially rearward movement of said spool; means intermediate said spool and said actuator for translating lateral deflection of said barrel into axially rearward movement of said spool to effect opening movement of said valve member; and externally adjustable rigid means in said body to selectively positively limit the range of rearward axial movement of said spool to correspondingly limit oPening movement of said valve member.

11. An automatic fluid dispenser comprising: a dispenser body; a spool mounted in said body for slidable axial reciprocation between positively fixed limits; an actuator mounted in said body for pivotal movement about a single axis; said actuator including a tubular barrel having a forward end that protrudes forwardly beyond a forward end of said body to terminate in a nozzle that is laterally deflectable to effect pivotal movement of said actuator barrel about said single axis; means intermediate a forward end of said spool and a rear inner end of said actuator to translate angular pivotal deflection of said barrel into axial rearward movement of said spool; and a valve means in said barrel that is operatively coupled to said spool to effect opening and closing of said valve member in response to axial movement of said spool between said fixed limits to control flow of fluids through an orifice in said nozzle.

17. A dispenser as in claim 16 in which said passage of said retainer is formed with an annular pocket and said seal means comprsies an O-ring in said pocket; said pocket also mounting a back-up ring for said O-ring at an axially forward end of said pocket, the axially rearwardly facing surface of said back-up ring being concave in radial cross section to define a complementary seat for said O-ring.