US3459341A - Piston type dispenser - Google Patents

Description

Aug. 5, 1969 J. c, coPELAND PIsToN TYPE DISPENSER Filed N041. '1, 1967 INVENTOR. Jocob C.Copel ond Zw! ATTORNEYS.

United States Patent O 3,459,341 PISTON TYPE DISPENSER Jacob C. Copeland, Chicago, lll., assignor of thirty percent to Orville N. Greene, New York, N.Y. Filed Nov. 7, 1967, Ser. No. 681,263 Int. Cl. B67d 5/42; C01f 1.7/00

U.S. Cl. 222-386 3 Claims ABSTRACT F THE DISCLOSURE This invention relates to improvements in piston type dispensers especially those piston type dispensers which are disposable.

The piston type dispensers such as disclosed in Gill Patent No. 3,248,014 include a piston actuating shaft which during shipment and storage is held within the dispensing cylinder. The actuating shaft contains a groove near the end thereof into which the :spring of a pusher means, positioned within or behind the piston, is adapted to snap to lock the actuating shaft thereto when the shaft is pulled away from the dispensing cylinder to the proper actuating position, so that said shaft is then capable of pushing the piston to discharge the contents of said cylinder.

In such a device, it is very difficult, if not impossible to dislodge the pusher means from its locked position on the actuating shaft once the shaft has been locked thereon. This is especially true when the pusher means is embedded in the piston. While it is desirable to be able to securely lock the actuating shaft on the pusher device or piston, the permanence of the lock presents some difficulties, for example, in assembling the piston and actuating shaft in unlocked position in the first place. The actuating shaft can be inserted in the piston from the rear or non-grooved end thereof, for example, but this is not always desirable and cannot be done if a knob or button to facilitate pushing is integrally formed on the rear end of the shaft.

Among the objects of this invention is to provide for `such a dispensing device, an actuating shaft and a piston containing locking means for the shaft which, after the piston is locked on the shaft, can be manipulated to unlock the shaft lfrom the piston.

The device of said Gill patent is also provided with a cap at the rear end of the cylinder back of the piston. (In the present specification and claims, the portion of the cylinder which contains the opening to discharge the contents of the cylinder will be called the front end thereof and the end through which the actuating shaft moves will be called the rear end thereof). The purpose of the cap is to prevent the operator from accidentally removing the plunger or piston from the rear end of the cylinder when bringing the shaft into locking position with respect to the piston. It is necessary to make tight fitting parts for such dispensers and often enough inertial force is developed in bringing the shaft to its locking position to also pull the piston out of the cylinder. It is also desirable to provide such devices as shown in Gill with Patented Aug. 5, 1969 finger rests surrounding the cylinder to enable one to discharge the contents evenly and completely.

Among other objects fo the present invention is to provide a capping device for the rear end of the cylinder of the dispenser which includes finger rests and which is lirmly held against accidental removal from the cylinder.

These objects and others ancillary thereto are obtained by providing a dispensing device of the type which includes a piston containing spring means to lock onto a groove in an actuating shaft, the actuating shaft containing two or more pairs of discontinuous grooves which are closely spaced to each other but so positioned that the deeply grooved portion of one pair of grooves is adjacent an ungrooved region between the other pair of grooves (preferably the separation of the respective ungrooved regions is about With this constrcution by simultaneously rotating and pushing the shaft, the piston can be moved past the grooved portion of the shaft. A cap provided for the device, is made of flexible plastic, and is constructed so that it can be inserted onto the rear, flared end of the dispensing tube and includes side projections forming finger grips to aid in discharging the device.

The device of the invention is adapted for medical, veterinary or industrial uses and the materials from which the parts are made may depend on the eventual use thereof. For medical uses, besides glass, polyethylene, polypropylene, urethanes, polyfluorocarbons, polyesters, nylons, silicones, polyvinyl chlorides, polystyrenes and polycarbonates have found acceptance in various capacities. Usually for medical uses, it is necessary to avoid materials which would contaminate the contents of the cylinder even to the slightest degree. For industrial uses it is only necessary that contamination that is harmful to the functioning of the contents be avoided. Polymers of ethylene vinyl acetate show promise for the plastic parts of the device.

In the accompanying drawing which illustrates, by Way of example, the constructional form of the invention:

FIG. 1 is a longitudinal cross `sectional view of a dispensing device made according to the invention `with the actuating shaft locked in position on the piston for discharging the contents.

FIG. 2 is a view similar to FIG. l but showing the actuating shaft in the position in which the devices are stored or shipped.

FIG. 3 is a detail plan view of the cap means.

The device shown comprises the dispensing tube 10, preferably of glass, the piston 20 of elastomeric material, the actuating shaft 30 conveniently of stainless steel or other plastic or alloy of equivalent inertness and corrosion resistance, the cap 40 of elastomeric material, the nipple S0 of plastic material, the ferrule 60 and the hypodermic needle 70 or other capping means.

The tube 10 has a liared rear end 11, a concentric front end 12 of reduced diameter and a beaded portion 13 on said front end 12.

The plunger 20 has embedded theerin the snap device 21. Said Snap device 21 is similar in internal structure to the common female part of a two-part snap device used on leather gloves and other garments, but instead of being fairly fiat said snap device 21 contains a somewhat elongated central neck portion 22 serving to maintain the alignment of the snap device on the shaft 30. The neck portion 22 contains openings 23 on opposite sides thereof through which spring loops 24 are adapted to project when not prevented by the shaft 30. The structure of spring or springs 24 may take the various forms such as used in the female elements of said conventional two-part snap connecting devices. As indicated in the drawings the snap device 21 is completely embedded in the solid portion of the plunger 20.

Plunger 20 also contains a hollow tubular portion 25 which is provided with a flange 26 at the rear end to provide a more effective seal. An opening 27 to admit the shaft 30 extends axially through the plunger.

The actuating shaft 30 includes a suitable pusher button 31 (see FIG. 1), a tip 32 at the front end thereof and two pairs of grooves 33, 34 and 35, 36 adjacent the front end thereof. The center portions of grooves 33, 34 are separated by about 90 from the center portions of grooves 35, 36.

The cap 40 contains opposiing projections 41 and 42 (see FIG. 3) for resting the first two fingers while the thumb pushes on button 30. As already mentioned this cap is constructed of elastomeric or fai-rly fiexible material since it .must be slipped over the fairly wide fianged end 11 of cylinder 10. The chamber 43 formed in the cap 40 to receive the flared end 11 of tube 10 has a countersunk opening 44 and an undercut interior 45 providing the interior flange 46. Thanks to the countersunk opening 44 the iianged end 11 of tube 10 can be forced into the chamber 43 and the undercut surface 45 prevents removal of the cap once it has been forced over flanged end 11. Preferably the central portion 47 of the cap 40 is of increased thickness over the thin walls 48 covering the chamber 43. The cap contains an opening 49 through which the shaft 30 passes.

The nipple 50 comprises a disk-like base adapted to rest on the rim of beaded end 13. T he nipple also includes a tubular opening 52. The nipple 50 is secured to the beaded portion 13 of the tube 10, `by the ferrule 60.

In operation, FIG. 2 shows the dispensing device as it appears when shipped or stored although the contents of the tube have been omitted. Thus until used the shaft 30 extends into the chamber of the tube 10 with the projection 32 at the end thereof closing the opening 52 in the nipple 50, the piston or plunger 20 of the device being adjacent the cap 40. When the actuating shaft is withdrawn from the chamber of tube 10 to the position shown in FIG. 1, the spring elements 24 snap into one of the pairs of grooves 33, 34 or 35, 36 thus locking the plunger 20 onto the shaft 30. The syringe is then ready to be discharged and is discharged in the usual way by placing the thumb on button 31, grasping the tube between the first two fingers which rest on the projections 41, 42 of the cap 40 and applying pressure by means of the thumb. The needle 70 can be shipped and stored with the device 10 or may be applied just prior to discharging the contents. The cap 40 prevents the plunger from being removed during the backward movement of the shaft 30 and its structure, particularly the interior surface 45 and flange 46, hold the cap on tightly while the contents of the tube 10 are being discharged.

To assemble the device, the plunger 20 can be inserted in shaft 30 from the front end by forcing the shaft into the opening 27 of said plunger until springs 24 catch on one pair of grooves 33, 34 or 35, 36 then the shaft is rotated with -respect to the plunger until the springs 24 are opposite the ungrooved region 'between the pair of grooves and the plunger is forced further on the shaft until the springs snap into the next pair of grooves from which the springs are ext-racted again by rotating the shaft 30 with respect to the plunger. After being used once the shaft and plunger can be made available for reuse in the same way.

The plural chamber device of Gill Patent No. 3,248,- 014 has not been illustrated in this specification but it is obvious that the improvements disclosed herein are useful in that type of device also.

The features and principles underlying the invention described above in connection with specific exemplifications will suggest to those skilled in the art many other modifications thereof.

I claim:

1. A dispensing device of the type thatv can be filled and stored ory shipped in compact or collapsed condition and then readily activated for use comprising a tubular barrel for holding the material to 'be dispensed, said tubular barrel having an open rear end with a ared rim and a discharge opening at the front end thereof and containing a piston means adapted to sweep the contents of the barrel toward the discharge opening, said piston means having an axial opening therein through which an actuating shaft is adapted to pass and including a locking means containing a pair of opposed springs adapted to extend into the opening of said piston means but also adapted to be forced to clear said opening,

a piston actuating shaft extending from outside the rear end of said barrel into said barrel, through the opening in said piston and at least about to the dispensing end of said barrel,

said piston actuating shaft containing at least two pair of unconnected grooves near the forward end thereof, each pair lbeing adapted to receive the springs of said locking means and thereby lock the locking means onto said shaft, one pair of said grooves being out of alignment with the adjacent pair of grooves whereby the piston means with its locking means can be inserted onto the shaft from the forward end thereof.

2. A dispensing device as claimed in claim 1, comprising cap means adapted to fit onto the rear ared rim of the tubular barrel to prevent removal of the piston means from the rear end of the barrel,

said cap means being formed of elastomeric material and having a countersunk opening and an undercut region back of said opening of approximately the configuration of said rim.

3. The device as claimed in claim 1 wherein the first pair of unconnected grooves on said actuating shaft is displaced about from the second pair of unconnected grooves.

References Cited UNITED STATES PATENTS SAMUEL F. COLEMAN, Primary Examiner

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