US2855928A - Syringe device for supplying repeatable sample volumes - Google Patents

Description

Oct. 14, 1958 M. s. REYNOLDS 2,855,928

SYRINGE DEVICE FOR SUPPIQ-YING REPEATABLE SAMPLE VOLUMES Filed July 12, 1957 2- Sheets-Sheet 1 5% fim/emal ffzmzzz/rg 5/1 6 Q 51 Oct. 14, 1958 M. s. REYNOLDS 2,855,928

SYRINGE DEVICE FOR SUPPLYING REPEATABLE SAMPLE VOLUMES Filed July 12, 1957 v 2 Sheets-Sheet 2 I z I I I t A, E V 1 7. ,4. A I

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United States atent O 2,8559% SYRINGE DEVTCE FOR sUPi LYiNii REPEATABLE SAMPLE VOLUMES Manning S. Reynolds, Chicago, Ill., assignor to Central Scientific Co., a corporation of Illinois Application July 12, 1957, Serial No. 671,634

3 Claims. (Cl. 128-218) My invention relates to a method and device for obtaming and supplying repeatable sample fluid volumes, and more particularly, to a method and device for repeat- .ably injecting test volumes of fluid into a testing area or .space.

The need frequently arises in scientific work for repeatedly testing substantially identical volumes of gases or liquids. The volumes required may be different for dif- :ferent experiments, but for any particular experiment, it is desirable to repeatedly provide substantially equal volumes of a gas or liquid.

A principal object of my invention is to provide a syr- Iinge device and method that conveniently supplies re- ;peated volumes of fluid.

A further object of my invention is to provide a syr-' tinge instrument set which makes it possible for the experimenter to supply repeated volumes of a test fluid, and yet which permits him to supply the volume desired fora gparticular series of tests.

Another object of the invention is to provide .a repeat-' :able volume syringe device which is composed offew :and simple parts, which is economical of manufacture, convenient in use, and readily adapted to a wide variety of applications.

Other objects, uses, and advantages will be obvious or become apparent from .a consideration of the following detailed description and the accompanying application drawings.

In the drawings:

Figure l is a side elevational view of one embodiment of my invention;

Figure 2 is an exploded perspective view of the elements making up the embodiment of the invention shown in Figure 1;

Figure 3 is a longitudinal cross-sectional view through the device of Figure 1, illustrating the manner in which ;the syringe is initially charged;

Figure 4 is a view similar to that of Figure 3, but illustrating a slightly modified arrangement;

Figure 4a is a fragmental elevational view illustrating ;a further modified arrangement;

Figure 5 is a view similar to that of Figure 3, but .illustrating an intermediate step in the operation of the device for providing the desired volume of fluid that is to be repeatedly injected by the syringe;

Figure 6 is a view similar to that of Figure 5, illustrating the syringe positioned to inject the desired volume of fluid that is to be repeated;

Figure 7 is a view similar to that of Figure 6 but illustrating the syringe after the desired volume has been injected;

Figure 8 is an enlarged cross-sectional view along line 88 of Figure 5;

Figure 9 is a perspective view of a set of spacers or repeatable volume providing elements that accompany and form a part of my syringe device; and

Figure 10 is a diagrammatic plan view illustrating an other embodiment of my invention.

"ice,

Reference numeral 10 of Figure 1 generally indicates a mechanical control type syringe device, or syringe type device, in which the principles of my invention have been incorporated, while reference numeral 10a of Figure 10 generally indicates an electrical control type syringe device. The device 10 comprises a transparent (though it need not be transparent) tubular cylinder 12 of a conventional syringe shape including an enlarged portion 14 and a reduced portion 16, the latter receiving a conventional tubular needle 18 or other fluid conduit means as may seem desirable or necessary under the circumstances. The cylinder 12 may be formed of glass or any appropriate material and includes a cylindrical chamher 2%) terminating at an opening 22 at one end thereof and a passageway 24 at the other end thereof that leads to the tubular needle 18. The cylinder 12 is formed with a collar 26 against which cooperate (in the embodiment of Figures 1-4 and 59) a selectable spacer 28, a permarientcylindrical spacer element 30, and annular knob or handle 32 of syringe piston 34. Piston 34 of the. embodiments of Figures 1-9 includes an elongate rod like element 36 which is integrally united with a stop means in the form of handle or knob 32. Element 36 serves the function of both a piston and a piston rod, it integrally uniting piston portion 35 and piston rod portion 37. The element 36 is received in chamber 20 and may be sufiiciently long in length to substantially fill the available space in chamber 20 when only spacer 30 separates handle 32 from contact with collar 26. The diameter of the element 36 is proportioned so that it will snugly but slidably fit within chamber 20 to provide the sealing action required in devices of this type.

. The permanent cylindrical spacer element 30 is an annular member formed from any appropriate substance and is provided with centrally disposed cylindrical perforation 40 which receives the element 36. The spacer 30 is formed with an annular groove or recess 42't0 receive thespring arms 44 of spacer 28. In the alternate arangement shown in Figure 4a, spacer 30a is made an integral part of piston 34a, handle 32a in effect being enlarged axially of the piston and formed with groove or recess 42 to receive arms 44 of spacer 28.

Spacer 28 comprises a member having a predetermined thickness, and which, in the illustrated embodiment, is,

generally quadrilateral in configuration and is formed with a Ushaped slot 48 which receives the member 36. Spring arms 44 are integrally united into a resilient spring 45 formed from any type of spring metal. Spring 45 includes a looped portion 47 that is secured about stem 50 of appropriate pin 52 which is tightly fixed in hole 49 of the spacer 28 and binds the spring 45 against pivotal movement. The sides 54 of the spacer 28 may be knurled as at 56 for ease in handling same.

' As' indicated in Figure 9, I prefer to provide a set of spacers for each syringe device 10. Each spacer 28a, 28b, 28c, 28d, and 28e is identical to the spacer 28 except that the thickness is different. The particular spacer. se-

28 selected to provide a desired volume of fluid are received over the member 36 in the manner indicated in Figures 1 and 3. The spring arms 44 of the spacer 28 are received in the annular, groove or slot 42 of the member 30 with the surface 60 of the member 28 abutting the end 62 of the spacer 30. This holds the spacer 28 to the spacer30.

the left as far as it will. go with. thespacers 28 and 30 interposed between handle 32 and collar 26 (the position of Figure 1) and then the needle 18 placed in a source or container of thefluid that: isto he tested. The piston 34 is then at leastpartially withdraw-n. frorn 'tthe cylinder (see Figure 3 which draws the fluidlinto the chamber 20 of the syringe through passageway 24. At this point, it is immaterial whether' or not the spacers move with the piston. After a charge has been brought into the chamber 20, the air is expelled (if a liquid is employed) and the piston 34 is moved to the left. of Figure 5 to expell. excess fluid, until the spacersprohibit further movement in this direction. This positions the syringe for discharge of the desired volume of fluid that is to be repeatedly provided.

The spacer 28 is then gripped in the manner indicated in Figure 5, or by grasping the knurled portions 56 of edges 54, and the spacer 28 withdrawn as indicated in Figure 6. The piston 34 is then forced to the left of Figure 6 to the position of Figure 7 which effects the discharge of the desired volume of fi-nid by bringing spacer 30 into contact with collar 26 (see Figure '7).

The c'olla r'26 and spacer 28 thus form spaced stop mernbers along the path of operation of piston 34.

For each test of the fluid required, the foregoing steps are repeated. This insures that the same volume of fluid is provided for each occasion that it is required.

The arrangement of Figure 4 is the same as that of Figure 3 except that the spacers 28 and 30 are in reversed positions. The embodiment of" Figure 4 operates in the manner described above, however, as does the embodiment of Figure 44.

Cylinder 12 may be provided with appropriate indicia as indicated in Figure 1'.

The device 10a' of Figure 10 includes a cylinder 12a that may be identical to the cylinder 12 of Figure 1,; and

thus includes an enlarged portion 14a in which chamber a is formed and a reduced portion 16a-in which pas sageway 24a is formed that lead to a needle or some receiver for the repeatable volume to be supplied by device 10a. Cylinder 12a is preferably fixedly mounted in any suitable manner, as by an appropriate clamp or the like. A piston 34a is reciprocably mounted in chamber 20, and includes piston portion 35a and ston ro po t o -3. ha i es in flange 2 Flange 26a includes an extension or arm 70 which op-, crates between two spaced limit switches 72 and 74 of any appropriate type. In the embodiment illustrated, each switch is shown as including a switch arm 76 pivoted as at 7 8 and biased in the direction ofthe arrow by compression springs 80. The switch arms 76 are electrically connected by lead 82; they respectively engage contacts 84 and 86 under the action of springs 80. Contact 84 is electrically connected to an appropriate source of electrical energy by lead 88 while contact 86 is connected to the stator coil 90 of appropriate shaded pole motor 92 by lead 93. The coil 9t) is connected to the source of electrical energy by lead 94.

Motor 92 includes a shaft 96 that moves crank arm 98 to reciprocate piston 34a through link I00 and rod extension 101. Appropriate rollers 102, may be provided for guiding the reciprocating action of rod'extension 101.

A push button switch 104 of any appropriate type is connected between leads 88 and 93. Motor 92 includes, pole coil 106 that is connected to contacts 108, '110, and 112 by appropriate leads. A switch arm 120 is pivotally connected to contact 110 for making contact: either contact 108 or 112, depending on the direction of motor rotation that is desired. Since shaded pole m otors' are; well known in the art, no further description of motor 92, is believed necessary, though it will be assumed that motor 92 will move piston 344 upwardly of Figure fit) when arm 120 closes contacts 108 and 1 0,, idthat movement in the opposite direction is achieved by arm 120 closing contacts 110 and 112. In any event, the

showing of Figure 10 is for illustrative purposes only, and it is to be understood that any electrical arrangement which will reverse the operation of piston 34a on contact of the extension or arm 70 with one of the switches 72 or 74 would be satisfactory and is within the scope of the invention.

In operation; assuming that. the extension or arm 70 is at the end of its injection stroke (its uppermost position), the passageway 24a is placed in communication with a supply of the fluidthat. is to be injected, arm 120 is placed in contact with contact 112, and switch 104 is closed to actuate motor 92. starts movement of piston 34a downwardly of Figure 10, which draws fluid into the cylinder 12a and also closes switch 72, which permits continued piston movement after switch 104 is released. When extension or arm 70 contacts switch arm 76 of switch 74-, switch 74 is opened which stops this downward or charging motion of piston 34a. Arm is then moved to close contacts 108 and 110, the passageway 24a-p1aced in communication with the space into which the repeated volume is to be injected, and switch. 104 again closed, which starts the ejection stroke of the piston 34a that provides the volume of fluid desired. Contact of the arm or extension 70 with arm 76 of switch 72 terminates the injection stroke, the above steps being repeated for each volume of fluid desired. Switch arms 76 thus form spaced stop members'along the path of operation of piston 34a.

The spacing between arms 76 of switches 72 and 74 determines the volume of fluid that is to be repeatedly injected, and it is understood that switches 72 and 74 will in practice be mounted for adjustment of the spacingbetween them, though this is omitted in the showing of Figure 1'0 for simplicity of illustration.

While the cylinder 12a is shown vertically disposed in Figure 10, it will be appreciated that this showing is forillust rative purposes only, and that the syringe cylinder is capable of being used in a variety of positions.

An important advantage of my invention is that the piston and its repeatable volume defining means may be employed with a wide variety of syringes of the same nominal size. Since the piston diameters of different syringe cylinders may vary slightly for syringes of the same nominal size, it is apparent that changing syringes may change the volume of the sample that is delivered.

However, this is entirely acceptable, as the goal is repeatable volumes, not exact volumes. The goal of repeatable volumes is attained so long as the same syringe is used throughout a series of tests.

Both liquids and gases can be supplied by devices 10 and 10a with equal facility.

The spacers 28 may be designed to provide liquid volumes on the order of, for instance, .005 cc. up to .060 cc.; if the spacers are to be employed to provide gas samples, a'larger volume range may be selected.

The foregoing description and the drawings are given merely to explain and illustrate my invention and the manner in which it may he performed, and the invention is not to be limited thereto except in so far as the, appended claims are so limited since those skilled in the art who have my disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.

I claim:

'1'. A repeatable volume syringe comprising a cylinderformed with a fluid passageway at one end thereof permitting flow of fluid into and out of the cylinder, a piston forming rod like element reciprocably mounted in said cylinder and extending outwardly of the other end of said cylinder, a handle carried by said element at its, outwardly extending end, said handle limiting the movement of said element toward said passageway by engagement with said other end of said cylinder, a spacer of predetermined thickness removably mounted on said element between said handle and said other end of said cylinder, and a spacer retaining member carried by said element between said handle and said other end of said cylinder, said spacer carrying a pair of resilient arms that grasp said member to retain said spacer on said element, whereby, said cylinder may be supplied with fluid by withdrawing said element away from said passageway to draw fluid into the cylinder through said passageway and then said fluid ejected to the limit permitted by said spacer, said member and said handle, by forcing said element toward said passageway until said spacer and said member cease movement by contact with said other end of said cylinder, whereupon said spacer may be removed to permit ejection of a predetermined volume of said fluid from said cylinder through said passageway based on the thickness of said spacer.

2. In a syringe device including a cylinder and a piston reciprocably mounted in the cylinder, the improvement wherein a pair of spaced stop members are provided along the path of operation of the piston which define the piston stroke length required to provide a predetermined volume of fluid ejection from the cylinder, and means for repeatably reciprocating said piston over said stroke length to draw said predetermined volume of fluid into said cylinder and eject said predetermined volume of fluid therefrom, said spaced stop members comprising a flange that is fixed with respect to said piston and a stop abutment that is fixed with respect to the cylinder, and a spacer element removably carried by said piston and disposed between said flange and said abutment, said spacer element defining said piston stroke length, and being removed to eject said predetermined volume of fluid from the syringe.

3. In a syringe device including a cylinder and a piston reciprocably mounted in the cylinder, the improvement wherein a pair of spaced stop members are provided along the path of operation of the piston which define the piston stroke length required to provide a predetermined volume of fluid ejection from the cylinder, and power means for repeatably reciprocating said piston over said stroke length to draw said predetermined volume of fluid into said cylinder and eject said predetermined volume of fluid therefrom, said spaced stop members comprising electrical switch means connected in an electrical circuit that controls said power means, and arm means carried by said piston for movement between said switch means, and means for reversing the direction of operation of said power means on contact of said arm means with one of said switch means.

References Cited in the file of this patent UNITED STATES PATENTS 1,649,022 Eisele Nov. 15, 1927 2,216,354 Pletcher Oct. 1, 1940 2,602,446 Glass July 8, 1952 2,607,343 Sarver Aug. 19, 1952

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