US2362080A - Dispensing device - Google Patents

Description

Noir. 7, 1944.

A. M. MARTINv DISPENSING DEVICE Filed ot. zes. 1942 2 sheets-sheet 1 lllllHlllllllllll Nov. 7, 1944. A. M. MARTIN DISPENSING DEVICE 2 Sheets-Sheet 2 Filed Oct. 26. 1942 Patented Nov. 7, 1944 msrENsmG DEVICE 1 yAndrew' M.

James A. McNeill Martin, Los Angeles, Calif., assigner to Wilco Company, Los Angeles, nership composed of Andrew Calif., a copart- M. Martinv lnd` application octoberzs, 1942, serial No. 463.420 i 4 claims. (c1. zza- 321) l", This inventlonrelates generally to spray or j'et devices, and is more particularly concerned with units adapted to be applied toliquid containers such as bottles or cans.

While 4by no means limited to such particular employment, kthe device may be used with particular advantage for jetting fine streams of oil for the lubrication of leaf springs and the like, or

for spraying wind-shields or windows with cleaningiiuid. It is so devised that, when applied to a container, the entire assembly may be supported by and thepump operated with a single hand.

It is among the 4objects of the invention to provide a pumping and jetting or spraying unit which is, within limits, adapted for universal applicability to various types of liquid containers. The usualtype of attachment between the unit and container is by way of a, screw cap carried by the unit and applicable to the threaded neck of a bottle or can. I have devised an assembly wherein all parts, except the container closure or cap, are of standard size, but the unit is adapted to take caps of different sizes, both as regards their diameters and as regards the thickness of their material. It thus becomes possible to make up the standard portions of the unit in large number .and then, by tting to them caps, either stock or specially fabricated, of sizes to take bottle necks of different diameters, the units may be adapted for attachment to the particular type of bottles supplied by individual customers.

Also, as a special feature, I have devised means whereby the units may be adapted for use in connection withv bottles of diierent heights. It is desirable that the intake of the pump be close to the bottom of the bottle, and since the pumping unit is suspended from the closure cap, the depending, over-all length of the pump is measured from the cap. If the over-all length were standard, the bottom of the pump would be differently spaced from the bottom of a tall bottle than from the bottom of a short bottle. Accordingly, while all parts of the pump, proper, may be of standard size, I provide for the reception of tubing extensions at the bottom of the pump barrel. Then, to fill an order for bottles of a given height, it is necessari/only to cut such lengths of .tubing as will, when applied to the lower end of the barrelr be in proper spacial association with the bottoms of those particular bottles.

As will appear from the detailed description` the unit is so fashioned as to be particularly eilicient in operation; and this efliciency will prevail irrespective of: the type of material used or the method of fabricating and assembling the various parts. However, eurent conditions practically preclude'the use of any appreciable amount oi metal in such devices,A and I have therefore de vised a unit which, except for a single spring, may be made entirely of plastic material. f l y.

In this connection, the unit is so fashioned that all the plastic elementskthereof maybeproduced as individual die castings, with the singlev exception that the barrel extension may be cut from lengths of extruded tubing. Asa matterof fact, several sets of all the elements may be produced by a single dieand press operation. -This not only contributes to the rapidity, ease and inexpensiveness of manufacture, but also insures interchangeability of parts with minimum trimming and fitting operations.

- With the principal parts thus made up of plastic elements,l special provision isl made for the assembly of those parts so -as to reduce their wear to a minimum. For instance, the metal spring is supported in a particular4 manner so that it may not, during pump operation, score or otherwise mutilate the wall ofv the barrel bore'. Also, the parts are fashioned so they may be assembled with ease and dispatch, avery important feature in connection with a quantity-produced article of this type. Additionally, of course, the plastic unit is of relatively little Weight, and certainly much below that of an all-metal unit, thus greatly reducing shipping costs.

The plastic material chosen is of a nature to resist attack or deformation by the liquid being pumped and, as distinguished from metal devices where particles of plating or of metal may choke the relatively small ports and orifices, there is little likelihood of clogging.

I have also devised a novel and very eiiicient type of spray or jet nozzle for the device. When the device is equipped with a jet orifice plateit is assured that the jet will be ne and even, and that it will be thrown in a straight stream, while, when the spray orifice plate is in use, it is assured that an evenv and ne spray will be projected. y

Other objects and features of advantage will appear from the following detailed description, reference being had to the accompanying drawings in which:

Fig. 1 shows an embodiment of the pumping and ejecting unit mounted in a bottle;

Fig. 2 is an enlarged section on line 2-2 of Fig. 1 with the valve stopper shown partially in elevation and only a portion of the bottle neck being illustrated. The parts are in the positions 'f ne. 41s

' g the plunger-head with theorilce plate removed,

' Fig.`6fisa section 'on ,down-strokeofthe plunger and at a point just VVjfshortf of the limlt'of that down stroke; d enlarged elevation of a 'detached' andviewedlfrom' the aspect of arrow 4 2;

Fig.- is' a section' on line 5-5 o f Fig. 14;

Fig. 7 is a sectionaiperspective 'as taken on line Figr is an enlarged, detached-view showing` the inner face of one form of orifice plate;

Fig. 9 is an enlarged, detached bottom view of I -the check valve;

Figno is a section Online lo-m or Fig. 2;' Fig. 11'is a bottom view of a valve cage; Fig. 12 is a sectional perspective view of the cage shown in Fig. ll and taken on the line I2-I2 of Fig. 11;

Fig. 13 is an detached orifice plate having certain characteristlcs diiering from theplate of Fig. 8; and

enlarged, inner face view of aposition of barrel I2 is determined by the upper .end 2|' of the bottle neck, it will be seen that in order to have the lower end of tube I9 in proper relation to the bottle bottom, the extension tubes must vary in length ifV the device is to be of universal adaptability to different height bottles. I

' length of thev die which forms barrel I2 to ac- A Aconimodate it to bottles of different height and it is unnecessary to separately fabricate, by individual extrusion operations, tubing extensions of exactly the right length to nt bottles of varying heights.

Extruded tubing varies somewhat in diameter throughout its length, but by tapering bore I5 it is possible, within limits, to fit the tubing to the barrel in spite of such variations. In fact, the tubing is usually suiliciently pliable that it -willaccommodate itself to the tapered bore Iby exposing it to sufficient end pressure. With tube Fig. 14 is a fragmentary enlarged section on be applied to other types of containers or to containers whose closures are other than screw caps.

While the elements of unit II) may, under the broader aspects of. the invention. consist of any suitable material, it is preferable from certain stand-points and as heretofore outlined, to make practically all such elements of thermo-plastic material which will withstand attack by the particular liquid being pumped. Thus, with the exception of the pump spring and, in some but not all instances, the bottle cap the unit, all elements may be made up 'of such a plastic, their shape and form all being such that theyare producible by well known die-casting operations. In speaking of attach, it will be understood that the term includes deformations of expansion or contraction. I'have found that thermo-plasticsl such as Vinylite resins particularly well serve the purpose. Therefore, from this point on it will be assumed that, preferably, all parts described, except the pump spring and, in certain cases, the bottle cap, are preferably madel of some such plastic.

The pump II Vis made up of cylindrical barrel I2 having a plunger-ta ng bore I3 which terminates in a lower conical seat I4, there being a square-cut annular shoulder I4a at the upper end of the seat. An upwardly and inwardly tapering bore I5 in the reduced tip I6 of the barrel, opens to inlet I'I at the lower end of seat I4, a downwardly facing annular shoulder I8 being formed at the junction of the bore and port. The lower end of seat I4 and shoulder I8 meet to form an annular knife edge I8' which defines inlet port I1. v l

Bore I5 is for the Vreception of the reduced diameter barrel extension or tube I9 which is preferably formed of extrudedplastic material. It is preferable that tube I9 extend to a point close to the bottle bottom 20. Since the bottles to which the pump umts may be applied come in dilferent heights and since, as will appear, the

which is carried by l IS thrust into bore I5, the barrel and tubing are united or adhered to one another in any suitable manner. However, I have found. the following method of unitingthe elements to be particularly eilective, though it is in no way to be considered as limitative on the invention. A small quantity of plastic solvent is applied to the two elements at an external point of meeting. This solvent, which, in connection with Vinylite, may be diluted acetone, creeps by capillary attraction between the adjacentl faces of the 'two elements, softening the meeting faces of those elements suiliciently to cause a co-mingling of the particles of material making them up. Then, when the material subsequently hardens, the two elements are, in effect, welded together. Hereinafter, when I speak of adhering any two plastic members, it will be understood that the proceeding outlined above may, preferentially, be followed, but it is to be distinctly understood that this is not limitative on the invention, as any other suitable uniting, adhering or cementing method may be employed.

It is found that knife edge I8' checks the capillary movement of the solvent from extending inwardly beyond port I1, thusvpreventing the solvent from reaching and damaging seat I4.

Barrel I2 has a longitudinally extending spill- Aage slot 2I (Figs. 2 and 10) in one side of the upper end thereof, and the plunger bore may flare slightly as at22, the flare starting about at the lower end of slot 2l, all for purposes to be described later.

A head 23 is formed integrally with the upper end of barrel I2, the head being made up of the relatively wide annular ilange 24 and an upstanding marginal flange 25 which gives the head cup shaped characteristics. This head 23 has multiple functions, as willappear later.

Adapted to seat on shoulder I4 and to control the iiow of iiuid through inlet II, is standing or inlet| valve 26 which is in the form of a cylindrical plug having a semi-spherical seating end 26. The cage limits the upward movement of valve 26 and also guides it to the extent that it is prevented from tipping out of substantial axial allnement with seat I4 and inlet I1.

Cage 30 has an upper annular wall 32 from which extends a central neck 33 having a reduced diameter central bore 34. Angularly spaced lugs 35 extend downwardy from wall 32 and define radial passageways 36 which allow communication, when valve 26 is in its uppermost position (Fig. 2), between neck bore 34 and the annular passage 31 which is represented by the annular clearance between cage 30 and cylindrical portion 29 of valve stopper 26. Neck 33 forms an upstanding projection for receiving, preferably with tight fit, and centering the lower end of spring l33 which shoulders against the top face of the cage, the upper end of the spring being received in and centered by the counterbore 39 provided in the lower end of plunger 40. This plunger has a cylindrical portion 4I which has piston-lit in barrel bore I3, and an inwardly and upwardly tapering portion 42 which extends from portion 4I to the reduced-diameter portion or cylindrical stem 43. Bore 44 extends from lcounterbore 39 tothe upper counterbore 45, the

purpose of which will later be described.

When plunger 40 is at the extreme bottom of its stroke (a little lower than the `position illustrated in Fig. 3) as determined by the contact of the lower end of the plunger with the upper end of cage 30, spring 38 is entirely housed within counterbore 39. By centering the spring in the manner described and by reason of the anhered during assembly. l It may be thus be considered broadly as a part of head 23 or barrel l2. 'I'he underside of the ring is hollowed out to provide an annular cavity 50 which, with the space 5I defined by tapers 22 and 42, serves during the up stroke of the plunger to receive any surplus liquid which may have previously leaked upwardly past piston portion 4I, such surplus liquid being subsequently returned through spillage slot 2| to the body of liquid L. 0f course, some of the surplus liquid spills directly through the slot during the up stroke of the plunger.

Ring 48 has an internal, annular and depending flange 52 supplying the aforementioned soulder 41. 'I'he flange serves as a wiper for stem 43, fitting it suiliciently closely that, on the up stroke the plunger, it will wipe oil' the major portion of liquid that Amay have been deposited thereon. However, if some of the liquid is carried past the wiping ilange, it will subsequently be deposited in the cup 53, formed by annularly depressing the upper face of the ring, from which cup the liquid will ultimately drain back into the pump barrel. l

Ring 48 has an annular flange 54 which is in opposed and vertically spaced relation to the upnular spacing of the spring from the wall of the' 35 barrel bore (which necessarily follows from the specified and illustrated nature of the spring mounting) the spring is kept from scoring or otherwise damaging the bore wall during ilexing of the spring, an important feature when it is realized that the plastic material making up the barrel is relatively soft and would be quickly scored or mutilated were the relatively hard spring to contact it. And, of course, it is necessary to preserve the smoothness of this bore wall if piston portion 4I of the plunger is to continue to have proper piston fit.

By reason of the described structure, it is unnecessary to complicate the barrel casting with integral valve-retainer means, and, after having introduced the cage as a separate element, no cage-retaining means is required other than shoulder 14a formed at the upper end of taper I4 and the spring 38, both the taper and spring being elements already provided to serve other necessary purposes.

An upwardly facing annular shoulder 46 is formed at the upper end of taper 42, which shoulder is adapted to contact shoulder 41 on retainer ring 48 to limit the upward movement of the plunger under the action of spring 38. `When the plunger is at its upper limit of travel, spring 38 exerts suilcient force to hold cage 30 against vshoulder I4a so it is assured that valve stopper 26 is constantly limited in vertical movement to an extent which precludes it from harmful displacement. However, the cage and valve stopper are so relatively proportioned and the normal position of the cage is such that the valve stopper is capable ofvertical play to and from seated position (Figs.` 3 and 2, respectively) for closing and opening inlet port I1.

Retainer ring 48 is of inverted cup shape, the annular flange portion 49 being adapted to fit nicely within head ilange 25, to which it is adper face of head ilange 25. I'he top wall or dome 55 of bottle cap C is centrally apertured aty 55a to take ring flange 49, while the ange or skirt portion 56 of the cap is formed with internal threads 51 to take the bottle neckthread 56. As has been stated, the invention broadly contemplates the inclusion of any type of container closure and any type of connection between container and closure.

As will appear, cap C is applied to head 23 before ring 48 is adhered to the latter, and the ring and head are so formed that they may be made of standard size and yet are adapted to accommodate manyl different types of bottle closures-either stock or special. For instance, in the illustrated case, a stock metal cap is shown, it only being necessary to punch or drill hole 55a in the cap dome to adapt it for this particular installation. In other words, no matter what the size of the cap may be, it may be fitted to the pump barrel assembly by centrally aperturing it to take the standard size flange 49. The circumferential fit of flange 49 within aperture 55a is preferably somewhat loose, so it does not radially compress ring 48 against stem 43 and so the bottle cap may be rotated independently of barrel I2 when the cap is being screwed onto or oil the bottle neck, though such looseness of fit is not essential to the invention considered in its broader aspects.

Opposed ilanges 25 and 54 maintain the bottle cap and pump barrel in assembly when the unit is out of the bottle, but, where the material of the cap is of the relative thickness here illustrated, the cap may shift, within the limits de- :lined by ilanges 25 and 49, vertically of the barrel when the unit is free of the bottle. By spacing flanges 25 and 54'relatively far apart, it is possible for standard sized units to take metal or plastic bottle caps of different thicknesses. In some instances, the cap domes may be of a thickness equalling the iiange spacing and thus, in effect, being clamped betweenthe flanges.

In' applying the unit to the bottle by screwing the cap to the bottle neck, the under side 59 of iiange 24 comes to rest on the upper annular face or shoulder 2I' of the bottle neck, and head 23 is thus clamped between the shoulder 2|' and the dome 55 of the cap. Unit I8 is thus firmly held centrally suspended within the bottle. Because of the relatively large radial extent of ilange 24, it will be seen that the unit may be applied to bottles having necks of dierent internal diameters. The illustrated bottle neck is of about the maximum size diameter which may be accommodated with a unit of the illustrated size, but it will be seen that the illustrated unit will also accommodate bottle necks of a diameter approximately as small as the outside diameter of barrel I2, measured just below head 23, or of any diameter between these limits. u

'Ihe flt of stem 43 through bore 48 of ring 48, the t of ange 24 on the bottle neck, and the screw-threaded fit between cap C and the bottle neck, while all of suiiicient tightness to insure no excessive leakage of liquid, are still not so tight as to prevent venting of the bottle. In other words, if, due to increase in temperature, the air pressure is increased within the bottle', the air above the fluid body may vent to the atmosphere between the stem and cap or between the bottle neck and cap. Of course such release of pressure may be very slow but it is sufficient to prevent the air pressure from building up to an extent which would otherwise force liquid L up through tube I9 and thence through the pump and discharge outlet. Slot 2| may thus be considered as a "breather or bleed' opening, since a certain amount of excess pressure may bleed from the bottle out through that slot into cavity 50 and thence upwardly between the stem and retainer ring.

Stem head or finger piece 68, by which plunger 40 is manually depressed to cause pumpl discharge, may broadly be considered a part of the plunger, though preferably it is fabricated separately and then adhered to the plunger stem. Head 60 comprises a cylindrical portion 6| and a aring portion 62, the latter having a saddle shaped upper face 63 to receive the operators ringer comfortably while pressure is exerted to depress the pump plunger, the length of the stem 43 being such that the operator may depress the plunger with a finger of the same khand which supports the bottle.

Head 60 has a bore 64 to take the upper end of stem 43, the end wall 65 of the bore defining the upper face of stem'43, the end wall 65 of the bore-defining the upper face of valve chamber 65' which is otherwise defined by the walls of counterbore 45. Within chamber 65' is check valve 66 (Figs. 2, 3 and 9) which is in the form of a small disk having a central projection 61 on its upper face and an annular seating ring 68,

preferably of approximately semi-circular cross y section, on its lower face. The valve is capable of limited vertical play within chamber 65' so it may move to and from a position to close the upper end of bore 44. The annular seating ring 68 not only has superior seating characteristics but it also serves as a stiiiening reenforcement for the small and delicate casting. Projection 61 is adapted to contact wall 65 when the disk is lifted (Fig. 3) and thus not only prevents the wet disk from Sticking to the wall but also prevents the outer edges of the raised disk from closing oil certain ports, to be described, opening through that wall.

On the down stroke of the plunger, valve 66 rises to allow the passage of liquid through the upper end of bore 44 into chamber 65', while on the up stroke of the plunger the valve closes, thus preventing external air from being drawn into the pump barrel in lieu of liquid from the bottle.

A circular recess 88 is provided in one of the outer and broader faces of head 64, and sunk below the bottom wall 18 of this recess and oi the same outside diameter as the recess, is an annular distributing groove 1|. Recess 69 is so located that its upper arcuate extent 12 projects above wall of bore 64, and throughout this upper extent the groove is deepened so it opens to bore 64, through top wall l5, at spaced points 13. The deepened arcuate portion 12 may thus be considered as a duct opening at one end to groove 1| and at the other end, via ports 13. to the top of bore 64, the ports 13 being separated by bridge 14. Duct 12 is of such depth that ports -13 extend radially inward beyond the upper rim 15 of stem 43, which rim annularly denes valve chamber 65', ports 13 thus opening into the valve chamber and, in eiIect, into bore 44 when valve 66 is open.

The effective cross sectional areas of the openings of ports 13 are represented by the approxiately triangular areas 13a (Fig. 5) defined by the corners of the duct openings and the annular defining face of the valve chamber 65', represented by the dot-dash lines in Fig. 5, though the ports are, in fact slightly larger than shown in this gure, since the inner edge of rim 15 is relieved as at 15' (Fig. 3) whereas the dot-dash circle in Fig. 5 represents the rim at a point of full thickness.

It will thus be seen that liquid passing upwardly through bore 44 and open valve 86, flows through ports 13 and duct 12 into the full-circle distributing groove 1|.

Fitting recess 68 and bottomed against wall 18 is an orifice disk or plate 16 (Figs. 13 and 14) or 16a (Fig. 8). Theorifice plate covers groove 1| and thus, with the walls of that groove, defines annular distribution channel 11 (Fig. 14).

Depending upon whether the device is to be used for jetting or spraying liquid, the disk 16 or 16a, respectively, will be used. In each form of disk there is a central discharge orice 18 representing the outlet end of a discharge passageway 19 which has a central conical portion 80 and an enlarged inner cylindrical portion 8|. That portion 82 of the discharge passageway which extends from oriice 18-to conical portion 80, is of uniform diameter throughout.

While there may be any desirable number of passages leading from channel 11 to the discharge passagewaysof the disks, I have found that two such passages generally suilice and give the best results. Thus, while this is not to be considered as limitative on the invention, considered in its broader aspects, in jetting disk 16, two radial and diametrically opposite channels 83, are provided in the inner face of the disk, the channels leading from annular channel 11. to discharge passageway 19, while in spraying disk 16a, two channels 84, spaced 180 degrees apart on the inner face of the disk, .extend tangentially from discharge bore 8| to annular channel 11.

Preferably, though not necessarily, channels 83 and 84 stop a little short of the outer periphery of disks 16 and 16a', respectively (Figs. 13 and 8) so there may be less danger of leakage at the juncture of the disks and the annular dening wall of recess 69.

by finger pressure on head 60 (Fig. 3) the liquid within bore 44 rises, in effect, through that bore, forcing check valve 66 open and then passes through orices 13a, duct 12, vannular channel 11, channels 83 or 84 (depending upon which orifice plate is in place) and thence'to the atmosphere through passage 19 and orice 18. If disk 16 (Fig. 13) is in place, the delivered stream will be in the form of a fine jet. If disk 16a is in place, the tangential arrangement of channels 84 gives the liquid a. whirling motion as it enters passageway 8| so, as it is emitted from orifice 18 after being fconstricted by taper bore 88 and passage 82, the liquid is discharged in a iine, even spray as at S in Fig. 3.

During the up stroke ofthe plunger as forced by spring 38 upon the relief of iinger pressure (Fig. 2) check valve 66 closes, while piston 4I draws liquid into barrel I2 to replace that which has been discharged, valve 26 opening to permit the upward ow from tube I9 through inlet I1,v

clearance channel 31, radial channels 36, and neck bore 34.

plied to any bottle which is of the length properly to receive tube I9 and whose threaded neck will receive the particular cap C which has been assembled with the unit.

While I have shown and described a particular embodiment of my invention it is to be understood that various changes in design structure and arrangement may be made without departing from the spirit and scope of the appended claims.

I claim:

1. In a pump unit of the character described, a pump barrel, a plunger within the barrel and having a stem portion extending outwardly be- As stated at the outset, it lies within the broader i aspects of the invention to utilize any suitable material for the unit elements and any suitable assembly procedure. Likewise it will be realized that certain of the sub-assemblies may be made up of integrally formed elements. However, also as noted previously, it is of special advantage to make the unit of plastic material and to fabricate it as illustrated. The parts are so fashioned that they are all producible by well known casting methods and are capable of being assembled accurately, quickly and easily.

Without limiting the invention in any manner or inferring that the order of procedural steps may not be altered, I will describe one method of assembling the unit.

i Tube I9 is inserted within counterbore I5 and fadhered to barrel neck I6, as has been described. Spring 38 is fitted over cage-neck 33,

: which it tightly embraces, and the spring and cage l are inverted so valve stopper 26 may be dropped into the cup of the cage. Barrel I2, in inverted position, is slipped over the cage, valve and spring, and the sub-assembly then turned back into normal position. Plunger 4I) is dropped over the upper end of spring 38 and bottle cap C is dropped onto flange 25. Ring 48 is then slipped over stem 43 and, after depressing the plunger to compress spring 38, ring ange 49 is iitted into head flange and adhered thereto.

Check valve 66 is then droppedv into counterbOre 45 and head 60 is fitted over stem 43` and adhered thereto, it being noted that it is unnecessary to rotate the head to any particular position on the stem in order to associatechamber 65 properly with openings 13. Theorifice plate 16 and 16a is iitted into recess 69 so its inner face engages recess bottom 10 and so its outer face is substantially flush with the outer face of the head. The disk is then marginally adhered" to head 80, it being noted that it is not necessary to rotate the orifice plate into any particular position, since channels 83 and 84 will 'register with circular groove 1I irrespective of the position to which the orifice disk is turned.

With the assembly thus completed it will be seen that the unit may be easily and quickly apyond the end of the barrel, an annulus secured to the body and encircling, with slight annular clearance, the stem portion of the plunger, and

a depending liange on the annulus and extending about and slightly annularly clearing the stem portion.

2. In a pump unit of the character described, a pump barrel, a plunger within the barrel and having a stem portion extending outwardly beyond the end of the barrel, a head on one end of the barrel, an annulus encircling the stem portion and adhered to the head, there being a ,cavity in the annulus which is in communication with the upper end of the barrel bore, and there being an opening through the barrel wall and communicating with said cavity.

3. In a pump unit of the character described, a pump barrel, a plunger within the barrel and having a stem portion extending outwardly beyond the end of the barrel, an external annular iiange at said one end of the barrel, an upstanding annular flange on the last named flange, a

centrally apertured container cap overlying the upstanding flange with the cap aperture in substantial register with the inner Wall of the upstanding iiange, a retainer ring encircling the stem portion of the plungerand tting within the upstanding annular flange, and an external annular flange on the retainer ring and overlying that part of the container cap which overlies the let, a cage for the valve allowing inlet-opening and closing movement to said valve, said cage being held against movement downwardly in the barrel and embodying an elongated solid annulus peripherally engaging the bore wall of the barrel, a hollow plunger within the barrel and having a stem portion extending outwardly beyond the other end of the barrel, a, spring between the plunger and cage and adapted to hold the cage against upward movement and to yieldingly press the plunger upward, an upstanding central and hollow neck on the cage, the bore of the neck being restricted in diameter as compared to `the bore of the annulus, the neck and annulus bores being in mutual communication, means on the of the barrel bore.

ANDREW M. MAR'I'IN.

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