US2605025A - Filling machine with controlled drawback - Google Patents

Description

INVENTOR.

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F. J. cozzoLl FILLING MACHINE WITH coNTRoLLED DRAWBACK Filed may 4, 1949 July 29, 1952 Patented July 29, 1952 l OFFICE FILLING MACHINE WITH i CON TROLLEDv DRAWBACK Frank J. comu, Plainfield, NJ.

Application May 4, 1949, serial No. 91,305

(o1. azz- 975)` 7 Claims.

The present invention relates to ampul and the like, lling machines and is concerned more particularly with an improvement designed to eliminate drop formation at the end of thelling needle. Av primary aim of the invention is to enable a user to fill an ampul or other slender throated tube with a liquid preparation'without wetting the tube neck'. N on-Wetting is especially important in the case of ampuls and tubes that are subsequent to filling, sealed by the application of heat. Whether the seal is made by drawing oif the tip of a tube or by sealing the tip, objectionable charring occurs if the interior of the tube neck in the region oi the seal has been wetted by the preparation. p

'A further aim of the invention is to prevent drop formation on the needle end in a manner that lends itself adaptable to large gauge as well as small gauge filling needles.v It has been observed that the drop that tends to form on the needle end at the completion of a lling cycle bears a relation to the unit quantity dispensed, size of needle, and viscosity of the medium being dispensed and to meet the various conditions arising in the eld this invention aims to provide a lling machine embodying a drop eliminator that is operative over the entire capacity range of the filling machine to prevent drop formation under all normal conditions of use.

The instant invention is in part a continuation of my application Ser. No. 62,121, filed November 26, 1.948, now PatentA No. 2,518,870, disclosing a filling machine having "a reciprocatingpiston and cylinder type of 4measuring unit, slide valve controlledl and a variable speed drive means for Vactuating the measuring unit andits valve in Xed. timedrelation. The present invention is disclosed in connection with av similar machine embodying a measuring unit, valve means thereforfand actuating means, but in which it has now beeny made possible to vary the timing of valve movement` relative. tofmeasuring and dispensing cyclesin a manner so as to effect a Vselected regressionof the .now in the needlev on completion of the 'vlling cycle' best 'suited to the character of the-mediumused, the needle size, and the unit quantity delivered. vWith they aid of" this invention, theuserv of the filling machine is. provided means operable over a wide'range of dierent conditions to prevent drop formation on the lling needle wherebyA wetting of tube throats and the objectionable consequences thereof isk avoided.

Qther objects and advantageswill be inpart indicated in the following description. and infpart rendered apparent therefrom iiiazconnection With the annexeddraWi-ngs-;

To enable others skilled in the art so fully-to apprehend the underlying features hereof ,that they may embody the same in the various ways contemplated by this invention, drawings depicting a preferred typical constructionehave been annexed as a part of this disclosure and,insuch drawings, like characters of reference denote cor-` responding parts vthroughout all the views, of which: n

Fig. 1 of the drawings isa side View of a'lli-ng machine embodying the invention,4 shown 'partly in section better tol illustrate itsconstructional features. f 1 I Fig.4 2 is 'a front view of portionsy of ther measuring unit drive and portions of the valve actuating mechanism. 1

Fig. 3 is a plan View of a preferred form' of; slide valve.

Fig. 4 is a sectional view, on a vertical plane of the valve. 4'

Fig. 5 is a front view, partly in section cfa. bined crank and valve actuating cam."

Fig. 6 is a projected view of Fig; 5.,'an'd; Fig'. 7 is a plan View of'Fig. 5.

With reference more particularlyl to Fig. I of the drawing the invention is disclosed in coni'- nection with a filling machine that comprises essentially a base member I0, a front panelII, a measuring unit I2, a control valve I3', `a llling needle I4 and a variable speed drive motor? I5 for operating the measuring unit and". valve whereby to effect pump action. The motor I5fis of commercial construction and equipped with a geared reducerya speed control handle. I6, are'- sistor and-lead cord (not shown) ina known manner. 'it' 'I'he motor shaft I5a extendsV forward and `car-"- ries a combined crank and cam member: IT to which one endof a connecting rod I8' isfec-l centrically pivoted as at IBa. The other end of the connecting rod is pivoted to the free end of an oscillatablelever I9 which in turn is'fixedly mounted upon a shaft 20v journaled inbearings provided by the front panel I I. The shaft-2 0 e'xl tends through the panel and carries an v'arc-- shaped lever 2 I` that operatesthe measuring unit |2 y;

The measuring unit, in the instant embodiment of the invention, is in the form of'a piston 22 and a cylinder 23 arranged substantially uponfa vertical axis. The cylinder is the lower member, preferably, and is pivotally connected to the arcuate lever 2l by means of a pintle yoke Ylll. The yoke is adapted for adjustment radially on the lever and isV clamped in the selected posi'tion'by a. clamp screw/'25; As thev `lever 2li is'oscillated the pintle yoke is raised and lowered and its masnitude of swing is determined by the radial position of the yoke on the lever 2i. If the yoke is positioned in coincidence with the pivot 2t, the stroke imparted to the cylinder is zero, and the more outwardly the yoke is positioned, the grear is the stroke imparted to the cylinder.

The piston 22 of the kmeasuring unit is formed with a hollow stein, indicated in Fig. l, through which the fluid is drawn in and expelled from the cylinder chamber during the reciprocatory motions of the cylinder. The upper end of the piston is screw threaded into the body part |30, of the valve i3. As illustrated more clearly in Figs. 3 and 4 the valve body i3d is mounted upon an oscillatable shaft 26 journaled in the panel l i, and is provided with three separate duid passages a, b, and c, the passage a leads to the filling needle via connections d and e; the passage c communicates witha supply conduit s; and the passage b communicates with the interior of the cylinderl 23 by way of the hollow piston. The three ports a, b, c, are normally isolated from one'another, but communication is established between ports a and b, and between b and c, in alternation, by means of an elongated bridging port f formed in the upper slide plate |312. In Fig. 4 the slide plate is in its rearmost position wherein the cylinder is connected with the supply conduit s, in which position, `iluid is about to be drawn' into the cylinder, whereas in Fig. l, the slide plate is in its forward position wherein the cylinder is in communication with the delivery conduits d and e and the fluid about tobe expelled from the cylinder passes through :the needle I4 to the interior of the ampul or Ytube to be nlled.

`The valve slide i3b is spring pressed against the body part l3a and is intermittentlyactuated in timed relation with the reciprocator'y movements of the measuring unit. The slide actuating mechanism includes a shiftable spool member 30 that is slidable on the shaft 26, av connection bar 3i that transmits the endwise motion of the spool 30 to the valve slide, a two-armed medially pivoted lever 32 that forks the spool 3U, and the aforementioned crank-cam i1 which is arranged to rock the lever 32 intermittently. As illustrated more clearlyin Figs. 5, 6, and "l, the Vcrank-cam IT is formed with two diametri cally opposite and axially opposite half-anges Ila and I'ib. The adjacent leading and trailing ends of the half-anges are correspondingly beveled to form inclined channels llc and Ild constructed and arranged to engage and shift the lower end of the valve lever 32 from one effective position to another in alternation. To minimize wear the lever 32 is provided with' a cam follower roller 32a at its cam engaging end.

It will be observed in Fig. 1 that the lever 32 is pivoted at 32o to one arm of a bell crank lever 35 which in turn isv pivotally supported, as at 35a, on the panel il. The other arm of the bell crank lever 35 is provided with a cross pin 3S, constructed in the form of a nut, for an adjusting screw 31. The bell crank is also recessed to receivea' compression spring 3B arranged to react against the panel l l and normally tends to move the bell crank 35 counterclookwise about its pivot 35a. The head of the screw 3l abuts the front of the panel l l, and iixes the position of the bell crank lever. As` the screw 3l is turned the threaded pin 35 is caused to travel in or out along the screw and in so doing the arm that carries the lever 32 is caused to raise and lowei.`

, elements.

accordingly. A pair of jam nuts Bla on the screw 3l limits the travel in one direction, and the panel itself limits the movement of the bell crank in the opposite direction.

The purpose of raising and lowering the lever 32 is to provide controllable means for preventing drop formation on the needle under different conditions, and is eifectedwith the present invention by varying the phase relations of the shifting movements of the valve and the reciprocatory movements of the piston and cylinder With reference to Figs. 2, 5 7, one of the oppositely disposed follower channels lid in the cam il is offset from a radial plane that intersects the crank axis 13a and the other cam channel Hc is substantially in that plane. The cam channel Hc is arranged to actuate the valve lever and to shift thevalve from its rearinost position (Fig. 4) to its forward position (Fig. 2) substantially coincidently with the completion of the intake stroke of the measuring unit so that the quantity entrained in the cylinder will discharge through the delivery channels and filling needle on the discharge (or upward) stroke of the cylinder. The cam channel Hd, however, is circumferentially offset from the aforesaid diametral plane, in a direction that causes the valve to be shifted from a delivery position (Fig. 2) to its intake position (Fig. 4) a short interval `of time subsequent to the startof the intake stroke of the measuring unit. With such an arrangement, the valve is late in relation to the intake stroke and on time in relation to the discharge stroke.

This delaying of valve shift at the end-o the delivery and at the start of the intake cycle, effects a drawback of a iixed quantity from interior of the needle and effectively prevents drop formation at its end. However, if the needle is large bored, the regress of fluid will be` inconsequential, if the needle is small bored the same quantity drawn back will be considerable and air may be drawn into the cylinder. Still again if the stroke setting for a selected volumetric displacement is small and the yoke 24 positioned relatively close the axis of the lever 2i, the drawback becomes substantially nothing as compared with the drawback produced when the yoke is outwardly positioned on the lever for a greater quantity displacement.

ln an attempt to obtain a controlled drawback under all conditions this invention proposes Va means for varying the lateness of valve shift occurring at the end of the delivery cycle to the end of obtaining a drawback that is no more than adequate to bring into the needle end the final drop of liquid that ordinarily tends to hang there. By so removing the droplet, the needle may be caused to enter and leave the narrow neck oan ampul without danger of wetting the sides. In attaining this end, it is proposed to superpose on cam channel i'id a further configuration operative to lengthen the dwell period of the valve to a greater or lesser degree depending upon the requirements. Fig. 5 illustrates the further configuration given to thebeveled leading end of the iange Ila and which is formed by slanting the face Ile thereof both circumferentially and axially rearwardly. Accordingly by raising or lowering the eiective position of the valve shifting lever 32, the follower roller 32a is caused to rest in a position as to be engaged by the cam face lle along a line more outward from the center of rotation of thecam or less outward from the center of rotation. If the position of the leve;`-- is such`r that the follower is, acted: upon by. the--inner'portionof' thelface lite, the valve will befshif-tedl sooner thang-if theleverfoccupiedfa more elevated-v position and the'- tollower== was. engaged by amore outwardlyl located portionlJofs-the compoundly slanted face'. IIIek of` tha-camA Us, Raising or lowering-` of theslever 3,2' has,l no effect upon itsoperativeconnectionv withLthe-islide shifting spool 3'0- for thereason that* thefwa'lls thereof thatl contain the forked: end. ofy liever 32 are parallel *and perpendicular to lthe axisA ofthe It will be further observed that the follower channel llc atthe opposite side of the cam I1 is formed, as. abovev indicated,- witn itsL camping surfaces at opposite sides of asllbstantiallydiametral planek and; the raising orY lowering of the follower roller thereinto has'no effect upon the timeliness of shift of the slide valve occurring attheA-end of; the intake-stroke-of the measuring l Withthepresent invention a simplel means Vis provided for eliminating drop formation and for controlling the amount of drawback in any of a wide range of variable conditions to the end of maintaining a dry needle so that the necks of small vials, tubes, ampuls and like containers are not made wet by the passing of the filling needle therethrough.

Without further analysis, the foregoing will so fully reveal the gist of this invention that others can, by applying current knowledge, readily adapt it for various utilizations by retaining one or connected. withjalmovable partgof the valve; and arelativelywid-e. facedfasymmetricalcam element operative to. actuatelsaid shiftableA member alter-r 'nately` to. twol effective --positions` corresponding to. the .two :effective positions, of'` the movable Parli of i the: valve;l and meansv tof shift said; shiftable memb'erarelativek to.l the face ofsaid cam. element thereby-5to change'the time o fmovement. off the valve from one. ofits positions totheothel. vuntil 'l the measuring lunit has. been..actuatedv a. plierv selected quantitative amount. l

3; A dispensing maclne Off the characterrde: scribed comprising inY combination; al vaable displacement liquid measuringv means, `valve means associated therewithloperative; to connect the measuringzmeans, alternately with amour@ offliquid toghe-dispensed andg with the lline needle ofthe machina; means., for actuating said measuring means; means foractuating said valve of said measuring means.

more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or specic aspects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, I claim as new and desire to secure the following combinations and elements, or equivalents thereof, by Letters Patent of the United States:

l. A means for eliminating drop formation on the end of a needle of a filling machine having a measuring unit, valve means operative to connect the measuring unit alternately with a bulk supply and with the lling needle, and means for actuating the measuring unit, comprising .in combination means for actuating the valve in timed relation with the operation of the measuring unit, said means including a pivoted lever connected to operate the valve, and cam means operative to actuate said lever about its pivot alternately to two eifective positions, and means operable to delay the movement of the lever from one of its positions until the measuring unit has been actuated a preselected unit of measure in a fluid intake direction, said last named means comprising a support for the pivot of said pivoted lever shiftable relative to said cam, and means operable to shift said support and thereby said pivoted lever relative to said cam means thereby to cause said lever to respond to the action of a selected portion of said cam.

2. A means for eliminating drop formation on the end of a needle of a filling machine embodye ing a measuring unit, valve means having two effective positions operative to connect the measuring unit alternately with a bulk supply and with the filling needle, and means for actuating the measuring unit, comprising in combination means for actuating the valve in timed relation with the operation of the measuring unit, said means including a shiftable member operatively 4. A filling machine comprising in combina.- tion a variable displacement measuring pump unit, valve means normally operative to connect said pump unit with a supply conduit on an intake stroke of the pump and with a discharge conduit on a discharge stroke of the pump, means including a cam element for actuating said pump unit and said valve means in synchronism whereby to cause said pump to receive and expel a predetermined quantity of liquid medium, and manually controlled means for varying the timing of the actuation of said valve means with relation to the timing of the actuation of said pump unit, comprising a shiftable cam follower member adapted to track said cam and screw means connected to shift said follower from one effective position to another effective position relative to said cam. y

5. A filling machine including a pump'and a filling needle adapted to deliver fluid discharged by the pump into a container combining, means connected to actuate said pump in a pump intake direction and in a pump discharge direction, valve means for the pump, means for actuating .said valve means intermittently in substantial coincidence with the chang-es in direction of actuation of the pump, comprising relatively shiftable cam and cam follower elements operative to effect movementof the said valve said pump unit with a supply conduit on an intake stroke of the pump and with a discharge

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