Piston type dispenser

April 26, 1966 w. gill 3,248,014

PISTON TYPE DISPENSER Filed Oct. 7, 1964

20\ 120'

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ATTORNEYS.

United States Patent Office

3,248,014

Patented Apr. 26, 1966

3,248,014 PISTON TYPE DISPENSER

Wilbur Gill, Highland Park, III., assignor of thirty percent to Orville N. Greene, New York, N.Y.

Filed Oct. 7, 1964, Ser. No. 402,278 9 Claims. (Cl. 222—137)

This application is a continuation-in-part of my U.S. application Serial No. 294,434, filed July 11, 1963, now abandoned.

This invention relates to a dispensing device and more particularly to a disposable, precharged dispensing package device for delivering a predetermined amount of liquid material.

Among the objects of the invention is to provide a compact syringe of the type having a plunger comprising a shaft-actuated piston or gasket, a barrel, and a nozzle or spout, which can be stored and shipped with the shaft of the plunger held within the barrel.

Among other objects of the invention is to provide a compact syringe of the type having a plunger or shaftactuated piston or gasket and a barrel, which is adapted to hold two or more different materials, to maintain said materials separate until ready for use, and to mix said materials prior to dispensing the same.

These and other objects ancillary thereto are obtained by providing a dispensing device with a syringe cylinder which includes at least one piston, or piston actuating shaft which is normally slidable with respect to the piston, and spring means adapted to lock onto a particular region of the actuating shaft when the latter is axially moved to bring said region into contact with said spring means. Once the spring means is locked on the actuating shaft, the dispensing device is ready to have the contents thereof discharged by said piston and its actuating shaft.

The spring means may be incorporated into the piston or may form part of a separate pusher means. Thus, where the contents of the cylinder is a fibrous coherent mass so that it is not necessary to sweep the walls of the cylinder or container, the close fitting piston can be omitted and the holder for the spring means acts as a piston.

Two or more spaced pistons (or gaskets) may be employed in said cylinder or barrel and different materials ⁴³may be maintained between the nozzle and the first piston, the first and second pistons, etc. Such materials may be maintained separately until ready for use and mixed only when about to be used. At least one of the materials should be liquid. Such provisions are desirable ³θ when the dispensing device is employed for dispensing a mixture of polymerizable resin with a catalyst therefor or a mixture of vitamins, i.e. where the two materials if premixed would harden, lose their potency or otherwist undesirably age in a way that they would not ⁵⁵do if maintained separately. See my U.S. Patents Nos. 3,013,697 and 3,082,914.

Since the actuating shaft for the piston must slip with respect to the piston and the spring means until locked by the latter, a very satisfactory means on said ⁶⁰shaft for fixing the connection with the spring means is some type of female element such as opposed notches or an annular groove. Preferably, the spring means has at least two male spring arms adapted to snap into the notches or the groove when the shaft is moved into posi- ⁵tion. The outer portion of the spring arms is held in the brim of a piston-like disk which, however, is preferably of metal and is smaller in diameter than the internal diameter of the cylinder. _

The pistons or gaskets are preferably formed of elastomeric material when they have to sweep the inside of the cylinder and also have to be leak-proof. The selections of the elastomeric material for such elements will depend somewhat on the liquids that are to be held in the device since it is obvious that such elements must be inert to the liquids held in the cylinder. Closed cell, porous poly-(tetrafluoroethylene) or poly-(trifluoromonochlorethylene) are inert to most liquids and are very satisfactory as piston materials. A durometer hardness of around 25 is very satisfactory. More inexpensive elastomeric materials may be employed, however, especially when the materials to be dispensed are relatively inert.

The actuating shaft for the piston can be made of metal, stiff plastic or other solid material of sufficient stiffness. The tip end of the shaft may also be shaped to close the nozzle opening of the cylinder when the shaft is in its shipping or storage position.

It has been found also that it is desirable for many applications to have a piston or plunger that is retractable after the shaft therefor has been locked in place and this is the primary difference between the present application and my copending prior application. To achieve this result, the spring means is embedded in the plunger or piston.

In the drawing:

FIG. 1 is a side view of a dispensing device made according to the invention and fitted with a hypodermic needle.

FIG. 2 is a view similar to FIG. 1 with the parts separated and with the plunger shaft fixed on the pusher means.

FIG. 3 is a cross sectional view taken along line 3—3 of FIG. 2.

FIG. 4 is a view similar to FIG. 1 but showing a modification with two pistons.

FIG. 5 is a view of the piston-shaft-pusher means of FIG. 4.

FIG. 6 is an enlarged detail view of the tip of the device of FIGS. 1 or 4.

FIG. 7 is an enlarged detail view illustrating features of the two-plunger device.

FIG. 8 is an enlarged detail view partly in cross section showing a modified form of the tip end of the device.

FIG. 9 is a view similar to FIG. 1 of a device for dispensing a cotton tampon.

FIG. 10 is a view similar to FIG. 7 but showing a modified form of plunger.

The device of FIGS. 1-3 comprises the cylinder or barrel 10, the plunger comprising the actuating shaft 11'and the piston 12, the tip 13 and needle 14. In FIG. 1 the shaft 11 has been partially withdrawn from its completely closed position in which the end fits into the tip 13 (see FIG. 6). Tip 13 may be formed of material which is more or less soft or pliable, such as plastic materials, soft metals such as lead and lead alloys, etc. The pusher element 20 which is an essential part of the invention is partially hidden in FIG. 1 by cup 15.

The actuating shaft 11 has a knob or button 16 at the outer end and preferably has a small projecting extension 17 at the inner end which is adapted to plug the hole 31 of plug 13 (see FIG. 6). An essential feature of the shaft 11 is the notched region or annular groove 21 (see FIGS. 6 and 7).: The annular groove 21 preferably has straight side walls so that when the shaft 11 is pulled out from the position shown in FIG. 1 to that shown in FIG. 2, the springs 22, 23 which are retained between the rim and the collar 24, of the pusher 20 snap into the groove 21 and more or less permanently affix the pusher 20 to the shaft 11. In withdrawing the plunger 11 until it is fixed to pusher 20, the cap 15 which is elastically or frictionally secured to the rim 18 of cylinder 10, pre

3,248,014 vents the shaft 11 with its attached pusher element 20, from being pulled out of the cylinder. The cap 15 does not function to retain the liquid in the cylinder of barrel 10 and in fact said cap is either fairly loosely fitted on shaft 11 or is provided with a small air hole to allow free entry of air into the cylinder back of the piston 12 as the latter is pushed forwardly by said shaft 11 and pusher 20. The cap 15, however, serves the very important function of limiting the backward movement of the shaft 11 when the shaft and plunger combination is being activated.

As illustrated in FIG. 3, very satisfactory pusher elements have double springs which are very strong and include also a small collar 24 adapted to stabilize the pusher on the shaft 11. Thus, the pair of springs 22 and 23 acting from opposite sides of the shaft 11 provide strong stabilized means for fixing the pusher 20 to the shaft 11, The modified form of device shown in FIGS. 4, 5 and 7 differs from the device of FIGS. 1-3 primarily in that a second piston or gasket 12' has been added which is positioned between piston 12 and the plug tip 13. Thus two separated chambers 35 and 36 are provided in cylinder 10 and these chambers may contain different materials. For example, chamber 35 may contain a polymerizable resin and chamber 26 a catalyst or accelerator or chamber 35 may contain a powdered vitamin preparation and chamber 36 a liquid vitamin or vehicle for the vitamin of chamber 35 such as tocopherol.

When two or more pistons are employed to divide the cylinder into two or more chambers the end of the shaft 11 must be constructed to prevent trapping of the liquid in chamber 36 for example. In the form shown in FIGS. 5 and 7 the end of the shaft 11 adjacent the tip 31 has a flattened region 32 so that this end does not quite close the opening in piston 12' as the two pistons come together and as shown in FIG. 7 allows all of the liquid in chamber 36 to be expelled into chamber 35. Any other form of groove other than flattened region 32 may be provided to permit escape of the fluid from chamber 36-35. In fact the end of shaft beyond the first piston 12 can be omitted altogether if the tip 13 is plugged from the outside.

Where very viscous liquids are to be carried by said device or when the liquids rapidly increase in viscosity after mixing as in the case of polymerizable resins there is danger that the plug 13 may be pushed out by said viscous liquid. In some cases this would not be detrimental and the plug 13 might be removed before extruding the mix. Where it is desirable to retain the plug 13 in place, it may be held onto the end of cylinder 10 by means of a metal or shrinkable plastic cap 38.

FIG. 9 shows how the invention is applied to a tampon dispensing device. In this device, piston 12 is shown which is smaller than the internal diameter of the container 10', since the contents 40 is a coherent matt of fibers, said piston 12 does not have to sweep the walls of the container 10'. Piston 12 can be omitted altogether if desired in which case the pusher device 20 acts as a piston. As shown, the opening 41 at the end of container 10' is of the same size as the internal diameter of the remainder of said container 10'. Where the contents 40 is a tampon, the withdrawal string (not shown) for the tampon may be fitted between piston 12 and the remainder of the body 40. All of the parts of the device of FIG. 9 except the springs of pusher device 20 may be made of plastic at very reasonable cost since container 10' and piston 12 do not have to be leak proof and since, piston 12 can be omitted altogether.

As already mentioned, it is often desirable to provide a plunger that can be retracted once the actuating shaft 11 has been locked onto the piston. The device illustrated in FIG. 10 provides such a plunger by embedding the locking element 20' in the plunger 120. When the locking element 20' is embedded in the plunger, as shown, the addition of the cap 15, to prevent withdrawal of the shaft 11 when withdrawing it to lock it in place, is of less importance and the cap 15 need not be fitted so tightly on cylinder 10 or may be omitted altogether. With the device of FIG. 10 the collar 24' need not be as long as in the device of FIG. 7.

In operation, the device of FIG. 1 is shipped without needle 14 and with barrel 10 containing the proper quantity of liquid to be dispensed. The shaft 11 is substantially completely held within barrel and preferably extends so that the tip 31 thereof plugs hole 17 of the tip 13. Packaged sterilized needles which are inexpensive enough to be disposable are available commercially, if desired however, the needle may be included as a part of the tip. If the contents of the barrel 10 are to be injected into an animal body the needle 14 is attached thereto, the button 16 is pulled until the pusher 20 snaps onto the shaft 11. Preferably, the barrel is held in a vertical position with the tip 13 upwardly when the shaft is pulled outwardly to snap it onto said pusher. Once the pusher snaps onto the groove 21 of shaft 11 the device is ready for use.

The device of FIGS. 4, 5 and 7 is operated in substantially the same way. It will be noted that the shaft 11: of this device acts as a triple stopper, thus the very tip 17 plugs the end opening 31 of cap 13, and the shaft portion thereof stops the central holes in both of pistons 12 and 12'. As shown in FIG. 7, the flattened region permits all of the fluid in chamber 36 to be transferred to chamber 35. After the fluid or materials of chambers 36 is all transferred to chamber 35, the two materials may be mixed by shaking for example, before being extruded from the barrel 10.

The device of FIG. 10 works in a similar way except that with the embedded locking element 20', the cap can be omitted and also since the plunger, comprising the shaft 11 and piston 120, can be retraced, the device can be reused and or refilled with another supply of liquid medication.

When the device of this invention is compared with the devices of my prior patents, it will be discovered that the device of the present invention is easier and more rapid to operate and that it does not have any complex parts or parts which are difficult to make or obtain. In fact many of the parts of this device are produced in substantial quantities and are relatively inexpensive so that the manufacture of disposable one-shot dispensers is entirely feasible.

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. It is accordingly desired that the appended claims shall not be limited to any specific feature or details thereof.