US3292621A

US3292621A - Jet type protable inoculator

Info

Publication number: US3292621A
Application number: US296192A
Authority: US
Inventors: Oscar H Banker
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-07-19
Filing date: 1963-07-19
Publication date: 1966-12-20
Anticipated expiration: 1983-12-20

Description

Dec. 20, 1966 o. H. BANKER JET TYPE PORTABLE INOCULATOR Filed July 19, 1963 INVENTOR. y OSCAR H. BANKER BY @www l? 7/ amig.

United States Patent O 3,292,621 JET TYPE PORTABLE INOCULATOR Oscar H. Banker, P.O. Box 9732, Bay Village, Ohio 44140 Filed July 19, 1963, Ser. No. 296,192 Claims. (Cl. 12S-173) This invention relates to jet type inoculators.

In my copending application, Serial No. 200,411 filed June 6, 1962, now abandoned, for Universal Inoculator, I describe and claim a jet type inoculator in which commercially available compressed ygas is utilized to energize a spring which in turn may be triggered to energize a liquid, and the latter in turn energizes a piston which acts upon the inoculant to eject it from the apparatus and into the epidermis of the patient. The said prior `jet inoculator is particularly well adapted for use in mass inoculations and for this purpose employs a relatively large tank -or cylinde-r of the compressed gas, which is connected to the inoculator through `a exible -hose to provide mobility for the inoculator.

In many situations, however, it would be desirable to be able to give a number of inoculations or injections by the jet method, because of its -relative painlessness, without requiring the use of the heavy tank of compressed gas. It is also desirable in all such inoculations to subject the inoculant initially to a high pressure for piercing the skin with a high velocity jet of the inoculant, after which the force is reduced to effect the actual inoculation.

It is accordingly an object of this invention to provide a small, readily portable, gas operated jet type inoculator in which there is automatically produced a high initial pressure for piercing the skin, followed by a gradually diminishing pressure for injecting the inoculant through the pierced skin.

As a more specific object, this invention `seeks to provide a plunger-operated inoculator wherein la. simple pressure-responsive release mechanism is used Ain conjunction with the plunger to restrain the operation of the device until a predetermined pressure is applied to the plunger. A feature of this invention is a plunger which is spaced from an ampule of inoculant and is made to strike the ampule upon the release of a mechanical pressure-responsive restraining device, said plunger being actuated by gas under pressure.

Y Although portable gas operated inoculators are not generally desirable for mass inoculations because of the limited quantity of compressed gas available in the small cylinders carried in such devices, it is nevertheless desira- -ble to conserve lthe quantity of gas yavailable as much as possible. It is thus another object of this invention to provide a valve control mechanism for the -gas for operating an inoculator, said mechanism being designed to close automatically upon the completion of the initial movement of an inoculant ejecting plunger, the remainder of the movement of the plunger being effected by the fixed quantity of `gas passed by the valve control mechanism.

The amount of inoculant to be injected into an individual depends upon the condition of the individual and upon his maturity. It is an Aadditional object of this invention, therefore, to provide a plurality of interchangeable stop mechanisms for limiting the travel of an inoculant ejecting plunger of a portable inocular to control the amount of inoculant ejected, with convenient means for storing the `stop mechanisms not in use.

Although the pressure within a bott-le of compressed CO2 gas remains at 80() pounds per square inch as long as there is any of the gas in liquid form in the cylinder, the pressure drops `off rapidly just as soon as the last vestige of liquid passes into a -gaseous state, and hence it is not possible to ioretell accurately when a bottle of v of inoculations from each bottle.

3,292,621 Patented Dec. 20, 1966 "ice the gas will be exhausted. Thus, if the bottle should become exhausted before the requisite pressure for a proper jet inoculation is developed, a partial ejection of the inoculant may be effected, and this at a pressure insufficient t-o pierce the skin of the patient so as to make use of the part ejected, thereby wasting the inoculant.

It is a further object of this invention to provide means i-n a gas opera-ted inoculator which will prevent the ejection of any of the inoculant until a predetermined pressure is developed in the gas.

The 8.5 gram bottles of CO2 gas used in portable, gas operated inoculators are normally furnished with a seal which when once pierced 'remains thereafter open. The pocket-size inoculator of this invention, however, is designed for intermittent operation, so that there .may be relatively lon-g periods after the bottle has been opened during which the inoculator will not be used. It is desirable, during such periods, to prevent any loss of gas so that the physician may be assured of a maximum number It is, accordingly, another object of this invention to provide valve means in the inoculator which will effectively close the bottle and lhold it in closed position indefinitely.

These and other objects and features of this invention will become apparent from the following detailed description when taken together with accompanying drawings in which;

FIG. 1 is an elevational view, partly in section, of the assembled gas operated pocket `size inoculator of this invention;

FIG. 2 is an exploded view of the inocula-tor of FIG. l, partly in section, and turned through 90 with reference to FIG. 1;

FIG. 3 is an enlarged fragmentary section through the inoculator of FIG. 1, showing the details of construction of the control valve therefor;

FIG. 4 is a plan view in section of the inoculator of IFIG. 1, the section being taken along lines 44 4 of FIG. 1 and looking in the direction of the arrows at the ends of said line;

FIG. 5 is a fragmentary, enlarged section of the snap action mechanism for transmitting the gas pressure to the rdevice containing the inoculant;

FIG. 6 is a bottom view of the inoculator of FIG. 1; and

FIG. 7 is a fragmentary section on an enlarged scale of the passage to the source of gas.

In the preferred form shown in the accompanying drawings, the inoculator is a generally cylindrical object having the inoculant orifice a-t one end thereof, the receptacle for the bottle of compressed gas :at the other end and a control for the valve disposed on the side of the cylinder substantially midway between its ends. The inoculator is particularly well adapted for use with an inoculant contained i-n a special cylinder known as 'a Metapule The Metapule is a substantially rigid cylinder capable of withstanding the relatively high momentary pressures impressed upon the inoculant therein by the present device, and has formed in one end thereof a rel-ative-ly rounded closure wall terminating in a nipple containing an orifice `of approximately .003 in diameter.

The Metapule is shown in FIG. 2 at L10, the `oriiice is shown at -11. The end of the Metapule opposite orifice 11 is closed by a rubber piston 12 which is adapted to be pushed into the Metapule to exert :a pressure on 'the inculant therein to force the inoculant `out through ori- Metapule 10 is adapted to be held in a sleeve or tube 13 which has an outwardly extending flange 14 at one end The inner diameter of flange 15 is smaller than the external diameter of Metapule 10, so that when the Metapule is inserted into tube 13, its piston end will be retained within the tube by flange 15. Tube 13 is retained in a fitting 16 having an opening 17 therein in which tube 13 fits with a sliding t. The outer periphery of yfitting 16 has threads 18 over which may be threaded a cap -19 adapted to extend around the orifice end of the Metapule to retain said Metapule in tube 13. To this end cap 19 has an opening 20 centrally located therein which is partially closed by a radially inwardly extending flange 21, the inner surface 22 of which is rounded to conform with the rounded contour of the nozzle end of the Metapule 10. Cap 19 also has a radially extending wall 23 which is adapted to overlie ange 14 and to clamp said flange against fitting 16 when the cap is threaded over the threads 18 on fitting 16. It is not contemplated that the Metapule 10 will be clamped between llange 15 on tube 13 and surface 22 on cap 19, but the space between flange and surface 22 is only slightly larger than the Metapule to take care of variations in the dimensions of these inoculant containing devices. When the Metapule is installed in the tube and cap 19 is in clamping relation over flange 14, the nipple containing the orice 11 extends through cap 19, slightly beyond ilange 21. This is shown in FIG. 1.

The means by which piston 12 of the Metapule 10 is forced into the Metapule to eject the inoculant contained therein is disposed in cylindrical housing 24. Said housing has -a recess 25 forced therein, the outer end of which is threaded as at 26 with an internal thread to receive the externally threaded end 27 of fitting 16. A radially outwardly extending ilange 28 on tittting 16 limits the movement of said iitting into recess 25 and provides a means for locating said fitting axially relative to recess 25.

Within recess 25 is located a pressure dilerential operated device or piston 29 which has formed integrally therewith a ram 30, the outer diameter of which is substantially the same as the internal diameter of flange 15. The length of rarn 30 is such that when tube 13 is clamped on fitting 16 and fitting 16, in turn, is tightened in recess 25 so its flange 28 abuts upon the end of housing 24, the end of ram 30 will be partially received within ange 15.

Referring now to FIG. 5, the means for obtaining a snap action operation of ram 30 will be described. It is contemplated that ram 30 will move into tube 13 against the piston 12 in the Metapule 10 with a hammer blow to create the initial high pressure in the inoculant required to pierce the skin of the patient. It is ycontemplated further that the movement of the ram will be effected by an expanding gas and that such gas will be expanding into recess 25 which is initially at atmospheric pressure so that the gas will gradually increase the pressure in the recess behind the piston. This is just the opposite of the the effect desired onthe inoculant, .e., it is desirable to have an instantaneous high pressure on the inoculant to pierce the skin, followed by a gradually diminishing inoculation pressure.

The conversion of a build-up of pressure on the ram to a hammer blow by the ram upon the inoculant is produced by the means shown in FIG. 5. The conversion means is designed to hold back ram 30 until a predetermined pressure is built up behind piston 29 and then to release the ram With a snap action to permit the ram 30 to move against piston 12 of the Metapule 10 with a hammer action. This is accomplished by the following instmmentalities:

A peripheral groove 31 is formed internally of flange 15, and a groove 32 is formed around the end of ram 30. A snap ring 33 is retained in groove 32, said snap ring having `a substantially circular radial cross section, the diameter of which is greater than the depth of groove 32, so that a portion of the snap ring extends outwardly radially beyond the surface of ram 30 and into groove 31 in flange 15. The depth of groove 31, however, is at least equal to the diameter of the radial cross section of snap ring 33 so that the entire ring may beV retained in groove 31. The wall 34 of groove 32 and the wall 35 of groove 31 are radial walls and serve to pinch snap ring 33 between them when ram 30 moves upwardly into tube 13. The depth of groove 32 is slightly less than one-half the diameter of the radial cross section of snap ring 33, so that a camming action will be created between the radial wall 34 and the rounded surface of the snap ring tending to cam the snap ring out of the groove as the ram 39 attempts to move into tube 13. The resilience of the snap ring and the relative proportions of the ring and groove 32 are predetermined to be such that the ring will not be cammed out of its groove until a pressure of at least 700 pounds per square inch is exerted against piston 29. Y

It may be noted that a space 36 is provided between the end of ram 30 and piston 12 of Metapule 10 when snap ring 33 abuts against wall 35. Thus when snap ring 33 suddenly releases ram 30, said ram in traversing space 36 acquires a momentum which, together with the suddenly released pressure behind piston 29, causes ram 30 to strike piston 12 of Metapule 10 with a hammer blow.

The movement of piston 29 and its ramr30 toward Metapule 10 is effected by gas entering a space 37 at the bottom of recess 25 behind piston 29. The gas is supplied from a bottle 38 of the compressed gas, the bottlebeing held in a container 39 secured to cylindrical housing 24 by a threaded connection 40-41 between container 39 and cylindrical housing 24.

The passage of gas from bottle 38 to space 37 is controlled by a valve shown generally at 42 in FIG. 3. Said valve includes a recessed plug 43 threaded into a transverse opening 44 in cylindrical housing 24 and sealed with i respect thereto by suitable packing such as O ring 45.` A

peripheral groove 47 in plug 43 is in communication with a passage 48 connected to the interior of bottle 38 so as to contain gas at 800 pounds per square inch pressure. One or more cross bores 49 connects peripheral groove 47 with the interior of plug 43. Within plug 43 is an Y end face valve 50 axially movable in plug 43 and normally urged to the right as viewed in FIG. 3 by a spring 51 bearing at one end against the closedend of plug 43 and at its other end against valve 50. The recess in plug 43 is of two diameters, the inner portion 59 of the recess being the smaller. YValve 50 is made with a pilot portion 60 which has a sliding tit with inner portion 59 of the recess in plug 43, and a face portion 61 disposed in the larger diameter portion of the said recess.

Valve 50 seats against the end of a sleeve 52 disposed in transverse opening 44 and appropriately sealed at one end with respect to housing 24 by an O ring 58. At the inner end of sleeve 52 O ring 45 is interposed between the adjacent ends of plug 43 and sleeve 52 to effect a seal between the plug and sleeve in addition to the seal it provides between the sleeve Iand opening 44. Sleeve 52 has a central opening 53 therein connected through cross bores 54 with a peripheral groove `55 aligned with an outlet passage 56 leading toward axially disposed valveY chamber 57 (FIG. 2) in housing 24. Said outlet passage in FIG. 3 is shown rotated out of its position in housing 24 for convenience in describing the passages provided forrthe gas. A cross bore 111 on valve 50 allows gas under pressure to enter behind the valve and causes it to be urged against sleeve 52, .e., to the closed position.

The head portion 61 of valve 50 has an O ring 62 retained in a recess in the end thereof by the head of an axially extending pin 63 pressed into a recess in said headk portion of valve 50. Said Oring 62 extends slightly beyond the end of valve 50 and beyond the periphery of the head of pin 63 so as to contact and seat upon the adja'- cent end of sleeve 52. Valve 50 is adapted to be moved oif its seat by a pin 64 which has a small diameter shank 65 extendingwith considerable clearance through central opening 53 in sleeve 52 into proximity to the head of pin 63. Said pin 64 has a conical valve portion 66 which has a maximum diameter greater than the diameter of central opening 53 so that when conical valve portion seats upon the outer edges of opening 53, said opening is effectively closed. The opposite end 67 of valve operating pin 64 extends through an opening 68 in cylindrical housing 24, where it may be reached from the outside. A shoulder 69 is formed between the conical section 66 and the extension 67, said shoulder serving to abut upon the bottom of counterbore 70 when conical section 66 is oi the seat in the sleeve 52 to act as a stop for said valve operating pin 64.

Axial movement is imparted to valve operating pin 64 by a lever 71 fulcrumed on a pin 72 supported by a stud 73 threadedly received in an opening 74 in cylindrical housing 24. A square corner 75 is formed in the outer end of stud 73 to act as a stop for lever 71 in its pivotal movement about pin 72 in a clockwise direction as viewed in FIG. 1. A stop in the opposite direction is provided by a thumb screw 76 mounted on lever 71 and extending toward the outer surface of cylindrical housing 24, so that the distance to which lever 71 can be moved in the direction of cylindrical housing 24 can be controlled. Lever 71 abuts upon the rounded end 67 of valve operating pin 64 and serves to move said pin inwardly of the housing and against valve pin 63.

The primary function of thumb screw 76, however, is to lock lever 71 in its inoperative position so that an inadvertent operation of the inoculator cannot take place. Thus, with thumb screw 76 -advanced until it strikes the side of cylindrical housing 24 with lever 71 released, no movement of said lever around pin 72 is possible. This conserves both the inoculant and the gas in bottle 38.

The gas for advancing piston 29 passes from outlet passage 56 into the axially disposed valve chamber 57, as previously described. Within valve chamber 57 is disposed a check valve 78 having a conical valve portion 79 adapted to seat on valve seat 80 which is threaded into the open end of said chamber 57. Said valve 78 has a guide portion 81 slidable in chamber 57 and recessed to receive a compression spring 82 which, is sufficiently strong to hold conical valve portion 79 on its seat against pressure in chamber S7 from bottle 38. Valve 78, however, is provided with a pin 83 which extends from the conical valve portion 79 through the valve seat 80 and into chamber 37 where it contacts piston 29. Said piston is normally held in a Iretracted or inner position with reference to its recess 25 by a spring 84 which is considerably stronger than spring 82, so that spring 84, in retracting piston 29 into the recess 25, also causes valve 78 to be pushed downwardly as viewed in FIG. 2 against the action of spring 82 to hold the conical portion 79 oii its seat 80.

Thus when gas under pressure is admitted to chamber S7, a passage is provided for said gas through seat 80 around pin 83 and into chamber 37. However, as the gas in chamber 37 increases in pressure and overcomes spring 84 and the aforementioned resistance of snap ring 33, piston 29 moves outwardly, and as it moves, pin 83 follows it until conical valve portion 79 contacts seat 80 to close the passage from chamber 57 to chamber 37. It is contemplated that the movement of piston 29 required to allow valve 78 to close will be very small so that the remainder of the movement of the piston is eiected by the expansion of the gas trapped between valve 78 and piston 29. As a result of the closing of valve 78, although lever 71 may be depressed by the operator to effect an inoculation and may be held in a depressed condition for an indefinite length of time, a fixed quantity of gas under pressure will be admitted to chamber 37 for each depression of lever 71, and this quantity remains the same regardless of the length of time that lever 71 is held depressed.

It is intended by the construction of valve 78 just described that gas pressure will be built up in chamber 37 to the point where it not only overcomes spring 84 but overcomes the resistance offered by snap ring 33, and when such pressure is reached, snap ring 33 will be cammed out of its groove 32 in the manner hereinabove described and piston 29 will move upwardly rapidly across the gap separating the piston from the Metapule and strike the Metapule to provide the initial high skin piercing pressure required at this stage. After valve 78 is closed, the gas entr-apped in chamber 37 expands against the action of spring 84, the expanding gas creating less and less pressure for the injection of the inoculant through the pierced skin. The compressed spring 84 increases its resistance to pressure until equilibrium is reached or the movement of piston 29 is arrested by means hereinafter described.

On the inlet side of valve 50 there is interposed between inlet passage 48 and bottle 38 a check valve 85 (FIG. 1) which is comprised of a iitting 86 threaded into a recess 87 in cylindrical housing 24 an communicating with inlet passage 48. Said tting 87 has a seat 88 against which a ball 89 is normally held by a spring 90. The strength of spring 90 is such that ball 89 will be held against its seat 88 until suicient gas under pressure is available from bottle 38 to effect a complete inoculation. Thus, spring 90 may be calibrated to hold ball 89 against its seat 88 until the pressure on the opposite side of said ball reaches 600 p.s.i. If this pressure is not reached the check valve will remain closed and will indicate to the operato-r that a new bottle of gas 38 is required. In this manner no incompleted inoculations will be performed and hence no inoculant will be wasted. Check valve also serves to conserve gas during intervals between inoculations even though those intervals may be of several days or weeks duration.

The exhausted gas upon the completion of an inoculation and the return of piston 29 to its starting position as shown in FIGS. 1 and 2, is vented through a passageway 91 (FIG. 3 and FIG. l) connected to recess 70. Passage 91, however, is closed to the gas behind piston 29, as long as lever 71 is held depressed andvalve 66 is thereby held againstV its seat in sleeve 52. Piston 29 therefore cannot return `to its starting position until lever 71 is released. Passage 71 is aligned with a passage 92 in stud 73 and with a continuation of passageway 91 beyond stud 73 leading to the exterior of cylindrical housing 24. This passageway, in turn, is in communication with the interior of container 39, and inasmuch as there is approximately 0.020 clearance between bottle 38 and the interior of container 39, said exhaust gas may pass around the bottle 38 and then out through the opening 93 in the opposite end of container 39.'

The inoculator shown in FIGS. 1 and 2 may be used as follows:

Assuming that container 39 has been unscrewed from housing 24 and that cap 19 has been unscrewed from the opposite end of container 24, the first step is to turn thumb screw 76 in a direction -to lock lever 71 against operation, that is, against turning around pin 72. Next, a bottle 38 of gas is placed in container 39 and the container is screwed into the bottom of housing 24. This' turning operation causes the point of needle 94 associated with check valve 85 to pierce the self-sealing cap normally supplied with bottle 38 (FIG. 7), and since the needle 94 is hollow, gas .under pressure from bottle 38 will pass through the needle and act against ball 89 to unseat said ball. As described previously, if the gas pressure is 600 p.s.i. or greater, said ball will be unseated and the gas will pass around ball 89 into the inlet passage 48 in housing 24 and thence to peripheral groove 47, cross bore 49, and the valve chamber in which valve 50 is disposed. The pressure of spring 51 and the unbalanced nature of said valve will hold said valve seated against sleeve 52.

A Metapule 10 is then placed into tube 13 and cap 19 is screwed in place over threads 18, thereby rendering` the inoculator ready, with the exception of the freeing of lever-71, for the performance of an inoculation. After the portion of the skin at which the inoculation is to beperformed has been properly sterilized the thumb screw 76 is backed off to free operating lever 71, the nose of the inoculator with its Metapule is pressed firmly against the sterilized portion of the skin and lever 71 is then pressed down. It is held down for approximately three seconds and during this interval valve 50 is opened to allow gas under pressure to enter space 37 behind piston 29-|through the valve 78. As the pressure builds up to the release point of snap ring 33, said ring will be cammed out of its groove 32 and ram 30 will jump across space 36 and strike piston 12 in Metapule 10, thereby impressing a high pressure thereupon, which results in the creation of a jet stream issuing from the orifice 11 in the Metapule against the skin to pierce it. As piston 29 moves away from check valve 78, the latter will close andthe fixed quanti-ty of gas trapped in space 37 then expands against the action `of spring 84 to eject the inoculant through the pierced opening in the skin into Vthe esh of the patient. After the lever 71 has been depressed for approximately three seconds, which is ample Vtime for the inoculation to take place, said lever is released and the entrapped gas under pressure in space 37 ows out through central opening 53 in sleeve 52, past the open valve 66 into passage 91 and thence out through container 39 and opening 93 to the atmosphere. Meanwhile valve 50 is closed by spring 51. v

The release of the gas under pressure in chamber 37 allows spring 84 to return piston 29 to its initial position. During such return movement, snap ring 33 slides along the outer surface of ram 30 until it falls into its groove 32. Near the end of lthe return movement, valve 78 is opened by piston 29 and gas pressure is then applied behind the closed valve 50 to assist in holding it in closed position. The inoculator is then ready for the next inoculation.

The foregoing description of the operation of the inoculator presupposes that a full charge of inoculant is to be injected. For the next patient, who may be a child, a lesser quantity of inoculant may be suicient. Such lesser charge may be effected by the mechanisms hereinafter to be described.

Since the quantity of inoculant injected is a function of the travel of ram 30 and its associated piston 29, it follows that by limiting the distance through which piston 29 travels, a limited quantity of inoculant may be injected. In the inoculator of this invention the travel of piston 29 is limited by a pair diametrically disposed pins 95, 96, each'having a head 97, 98, respectively,'the axial dimension of which is substantially equal to the axial dimension of flange 14 on tube 13. Said pins are received in corresponding openings 99 and 100 (FIG` 4) in fitting 16, said openings extending axially therethrough. When the pins are in place in their respective openings, cap 19 serves to hold said pins against axial movement out ofthe openings. As shown in dotted outline in FIG. 2, a pin 96 will extend into the path of movement of piston 29, and hence, by selecting a pin of appropriate length, the length of travel of piston 29 in housing 24 can be determined. It is contemplated that a plurality of pairs of pins of different lengths will be available from which a selection can be made.

For the sake of convenience, a pin holder of magazine is provided-in container 39, the cylindrical wall of which may be drilled with a series of pairs of openings 101 in which pairs of pins of different lengths may be stored. The bottom end of container 39 as viewed in FIGS. 1 and 2 has a reduced diameter as at 102 to form a shoulder 103 against which a dispenser ring 104 is held by a snap ring 105. Openings 101 are enlarged at their outer ends to receive the heads 97, 98 of the pins. 4Dispenser ring 1.04 extends across the openings 101 and the pins retained therein-to hold them againstfalling out of their respective openings. Said dispenser ring has an opening 106 therein which may be aligned with an opening for a pin so that a pin may be dropped through Vthe dispenser ring 104. Indexing of dispenser ring 104 for the selection of a given pin is facilitated by inscribing appropriate indicia 107 on the exterior of container 39 and by inscribing an arrow 108 on the exterior of ring 104, such that when arrow 108 is aligned with a given index, opening 106 will also be aligned with the pin corresponding to the size designated on the index. Dispenser ring 104 may be turned to a position in which it blocks all of the openings 101 to hold all of the pins in the magazine. It is held in such position by a spring detent 109 disposed in container 39 and cooperating with the opening 101 in ring 104. Y

A gas bottle of 8.5 gram size is ordinarily good for 25 or 26 shots when used with prior art inoculators. With 1 the inoculator described above however, because of the valve 78 which limits the amount of gas used per inoct ulation, irrespective of the length of time that lever 71 is held in operative position, a significant saving of gas is effected so that the same bottle of gas may be used to effect 32 to 35 inoculations.

The foregoing description is merely illustrative of a preferred embodiment 0f this invention and the scope of a ram for engaging and moving said piston into the rel ceptacle yto eject inoculant through said orice, said ram having a circumferential groove, guide means on the heusing for said ram, said guide means having a ,groove adapted to be aligned with the groove on the ram, and radially expansible resilient means in the groove on the ram and extending into the groove -on the guide means, said radially expansible resilient means and said groove on the ram` having cooperating camming surfaces adapted upon the attainment of a predetermined axial force upon the ram to cam said radially expansible resilient vmeans out of the groove on the ram into the groove on the guide means to release said ram for movement against said piston.

2. An inoculator comprising a housing, a receptaclel for inoculant secured to the housing, said receptacle having an'orice at one end and a piston at its other end,`

a ram for engaging and moving said piston into the receptacle to eject inoculant through said orifice, said ram` having a circumferential groove, xed guide means On the housing for said ram, said guide means having a groove adapted to be aligned with the groove on the ram, a snap ring in the groove oni-the ram and extending into the groove on the guide means, and means for exerting axial` pressure upon vthe ram, said snap ring being adapted, upon the attainment of a predetermined axial pressure upon the ram to be cammed by the guide means, out of the groove on the ram into the groove on the guide means to release said ram for movement against said piston.

3. An inoculator as described in claim 2, said means for exerting axial pressure upon the ram'comprising a source of gas under pressure, valve means on the housing for admitting said gas under pressure into said housing `behind said ram, and means controlled by the movement of said ram for limiting the quantity of gas admitted into said housing behind said ram for each operation of said valve means.

4. An inoculator as described in claim 2, said means for exertingV axial pressure upon the ram comprising a` sure into said housing behind said ram, and means controlled by the movement of said ram forlimiting the quantity of gas admitted into said housing behind said ram after said manually operated valve means has been operated for a predetermined time interval.

5. An inoculator as described in claim 2, said means for exerting axial pressure upon the ram comprising a source of -gas under pressure, a valve on the housing for admitting gas under pressure behind said ram, manually operable means on the housing for holding said valve in gas-admitting condition, a second valve in the housing disposed between the first valve and the ram and adapted to block the flow of gas under pressure from the first valve to the ram, means on the second valve adapted to be contacted by the ram` during the imtial movement of the ram toward said piston to hold said second valve in open position during said initial movement, and means for closing said valve immediately after said initial movement.

6. An inoculator as described in claim 2, a source of gas under pressure, valve means on the housing for admitting said gas under pressure int-o said housing behind said ram, and check-valve means in the housing adapted lto prevent admission of gas under pressure to the ram until the pressure of said gas exceeds a predetermined value.

7. An inoculator as described in claim 2, and means for limiting the movement of said ram whereby to limit the amount of inoculant moved by said piston.

8. An inoculator as described in claim 2, a source of gas under pressure, a container for said source of gas under pressure, removable pins interposed in the path of movement of the ram to limit the movement of said ram, said container having axially disposed openings in its wall for receiving removed pins, closure means for the axially disposed openings, and means for rotatably mounting the closure means on said container, said closure means having a single opening alignable successively with the axially disposed openings through which a pin may be removed, upon rotating said closure means.

9. An inoculator as described in claim 2, said housing comprising a cylinder having recesses extending axially inwardly from both ends, means in one recess for securing thereto a container for gas under pressure, a passage connecting the recesses, a check-valve in the passage for preventing flow of gas through the passage when the gas pressure falls below a predetermined value, a manually controlled normally closed valve in the passage, a pressure diierential operated device in one of the recesses connected to the ram, and a valve controlled by the position of said pressure differential operated device in the said one of the recesses for closing said passage.

10. An inoculator comprising a housing, a receptacle for inoculant secured to the housing, said receptacle havin-g an `orilice at one end and a piston at its other end, a ram in the housing for engaging and moving said piston into the receptacle to eject inoculant through said orilice, pressure dilferential operated means in the housing for operating said ram, a source of gas under pressure, said housing having a passage for conducting said gas under pressure from said source to said pressure diierential operated means to operate said ram to engage said piston, normally closed valve means for preventing said gas from moving through said passage, manually operable means for opening said valve means, a second valve in said passage adapted to close said passage, and means responsive to movement of said ram for closing said second valve after the piston has commenced its movement into the receptacle but before such movement is completed, Whereby to trap a predetermined quantity of gas in the housing behind said pressure differential operated means and complete the ejection of inoculant by the expansion of the trapped gas.

11. An inoculator as described in claim 10, said ram being normally spaced from said piston, and pressure responsive means for restraining movement of said ram toward said piston until a predetermined pressure is impressed upon said ram.

12. An inoculator as described in claim 10, said pressure differential operated means for operating said ram comprising a piston formed integrally with said ram.

13. In an inoculator the combination of a housing, a receptacle 'for inoculant secured to the housing, said receptacle having an orifice at one en-d and a piston at its other end, a ram in the housing for engaging and moving said piston into the receptacle to eject inoculant through said orifice, pressure operated releasable means holding the ram spaced from the piston, and means for exerting pressure upon the rarn in excess of the pressure required to release said releasable means, said ram upon being released by said releasable means traversing said space and striking said piston to develop an instantaneous pressure in the inoculant which is greater than the pressure required to release said releasable means.

14. An inoculator comprising a housing, a receptacle secured to the housing, said receptacle having an orifice at one end and a piston at its other end, ram means for engaging and moving said piston into the receptacle to eject inoculant through said oriiice, a source of gas under pressure, said housing having a passage for conducting said gas under pressure from said source to said ram means, valve means on the housing for admitting gas under pressure behind said ram means to elect the engagement and movement of the piston by the ram means, and check valve means in the housing adapted to prevent admission of gas under pressure to the ram until the pressure of said gas exceeds a predetermined value.

15. An inoculator comprising a cylindrical housing having recesses extending axially inwardly from each end, an apertured cap adapted to be threaded over one end of said housing, a sleeve in the said one end and extending into one of said recesses, a radially extending flange on the sleeve adapted to be compressed against said one end of the housing by said cap, a receptacle for inoculant in the sleeve and tting closely thereinto, said recptacle having in one end an orice extending through the opening in the cap through which inoculant is adapted to be ejected and a piston in its other end adapted to be moved into the receptacle to eject said inoculant, a ram in the sleeve, said ram having a peripheral groove, said sleeve having a groove adapted to be aligned with the groove on the ram, a snap ring in the groove in the ram, said snap rin-g having a circular radial cross section the -radius of which is gsreater than the depth of the groove in the ram such that said snap ring will be cammed out of the groove in the ram and into the groove in t-he sleeve upon the exertion of a predetermined axial pressure upon said snap ring, a piston in the said one recess for moving said ram, a spring in the said one recess acting upon said piston to restrain movement of said piston toward said ram, a container threaded into the recess in the other end of said housing, said container having a central opening which is smaller at its end removed from the housing and larger at its end adjacent said housing, a bottle of gas under pressure in the larger part of the opening in said container, said bottle being larger than the smaller portion of said opening, hollow needle means on the housing piercing said bottle, a passage in the housing from the hollow needle to the piston in said recess to conduct gas under pressure from the bottle to the piston, a check valve in said passage adjacent the hollow needle and adapted to prevent passage of gas from said bottle to said passage except when the pressure of said gas on said check-valve exceeds a predetermined value, a normally closed valve in the passage adjacent the check-Valve, a manually operable lever mounted on the exterior of the housing, a pin extruding from the normally closed valve to the lever for opening the valve with said lever, a second normally closed valve in the passage adjacent the iirst said normally closed valve and operable by the piston in the recess when said piston and its associated ram are retracted away from the inoculant receptacle to its open position, diametrically disposed openings in the said one 1 1 end of the housing and extending toward the piston in the recess, pins in each of said diametrically disposed openings and exten-ding into the path of movement of said piston in the recess, each said pin having a head adapted to be received between the cap and housing end covered thereby to hold said pins in fixed relation to the lhousing, said pins serving to limit movement of said piston and ram toward the inoculant receptacle, an apertured cap for the container, means mounting the capon the container for rotation relative thereto, said container having axially extending recesses covered by the cap for storing pins therein and detent means for holding the cap in a selected angular position relative to the container,

1 2 said` cap having an opening therein adapted to be aligned with a selected recess through which a pin may be inserted or removed.

References Cited by the Examiner UNTED STATES PATENTS 10 RICHARD A. GAUDET, Primary Examiner.

ROBERT E. MORGAN, Examiner.

3/1960 Vendtty et al 128--172 3,057,349 10/ 1962 Ismach 12S-173 i UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3, 292 ,621 December 20 1966 Oscar H. Banker It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Co1umn 3, line 29, "forced" should read formed Column 6, line 19, "an" should read and Column 10 line 45 "gsreater" should read greater Signed and sealed this 12th day of August 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E.

Commissioner of Patents Attesting Officer

Claims

14. AN INOCULATOR COMPRISING A HOUSING, A RECEPTACLE SECURED TO THE HOUSING, SAID RECEPTACLE HAVING AN ORIFICE AT ONE END AND A PISTON AT ITS OTHER END, RAM MEANS FOR ENGAGING AND MOVING SAID PISTON INTO THE RECEPTACLE TO EJECT INOCULANT THROUGH SAID ORIFICE, A SOURCE OF GAS UNDER PRESSURE, SAID HOUSING HAVING A PASSAGE FOR CONDUCTING SAID GAS UNDER PRESSURE FROM SAID SOURCE TO SAID RAM MEANS, VALVE MEANS ON THE HOUSING FOR ADMITTING GAS UNDER PRESSURE BEHIND SAID RAM MEANS TO EFFECT THE ENGAGEMENT AND MOVEMENT OF THE PISTON BY THE RAM MEANS, AND CHECK VALVE MEANS IN THE HOUSING ADAPTED TO PREVENT ADMISSION OF GAS UNDER PRESSURE TO THE RAM UNTIL THE PRESSURE OF SAID GAS EXCEEDS A PREDETERMINED VALUE.