US 3353718 A
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Description (OCR text may contain errors)
NOV. 21, 1967 J. F, MCLAY SYRINGE, COLUMN OR THE LIKE Filed May 24, 1965 2 Sheets-Sheet l Arr /w--xY JOSEP/v F. Mc AY -Q m--- w l. m w f Nov. 2l, 1967 v x. F. McLAY 3,353,718
SYHINGE, COLUMN OR THE LIKE Filed May 24, 196e v r.2 sheets-shewb 2 I JfE/D/-l BY A raf/Vix United States Patent O Pennsylvania Filed May 24, 1966, Ser. No. 552,519 14 Claims. (Cl. 222 158) The present invention relates to a new and useful pistondrive construction for liquid-tight and gas-tight syringes used in chemical analysis and for other micro-metering chemical apparatus and the like, and also relates to certain other new and useful constructional features of such syringes and the like, as indicated more fully in the following description and accompanying drawings.
One of the objects of the present invention is to provide a screw-feed for the plunger or piston of a gas-sampling syringe or for the piston or plunger of micro-metering cylinder-and-piston chemical apparatus which will provide the desired fine adjustment of the travel or of the position of the plunger or piston and provide, optionally, a rapid advancement and retraction of the plunger free of the screw-feed thereof and a tine screw-feed advancement and retraction of the piston, and will also provide for a rapid and convenient change-over from screw-feed to non-screw-feed movement of the piston.
Another object of the present invention is to provide a gas-tight and Huid-tight plunger or piston for syringes and for other column type chemical apparatus and the like, whose position may be adjusted by line screw-feed and which may be retracted free of the screw connection.
With the above and other objects in view, which will appear more fully hereinafter, the present invention consists of the novel constructions and constructional features hereinafter described and shown in the accompanying drawings and set out in the claims hereinafter appearing.
In the accompanying drawings, hereinafter described, like reference-characters indicate like parts.
FIGURE 1 represents an elevational View of a syringe representing one embodiment of the present invention, with the tapered needle-receiving tip of the glass syringe body and with the metallic needle-attaching sleeve or hub shown in cross-section.
FIGURE 2 represents a cross-sectional View l(partly broken away) on line 2 2 of FIGURE l, on a scale approximately ythree times that of FIGURE 1 with the piston-coupling slider shown in its uncoupled position.
FIGURE 3 represents a cross-sectional View on line 3 3 of FIGURE 4.
FIGURE 4 represents a cross-sectional view on line 4 4 of FIGURE 2.
FIGURE 5 represents an elevational view of the piston and f the lower end of the piston-rod-shown partly in cross-section in line 5 of FIGURE 2.
FIGURE 6 is a cross-sectional view of the top of the syringe shown in FIGURE 2, but with the piston-coupling slider shown in its coupling position.
FIGURE 7 represents a top plan view, generally on line 7 7 of FIGURE 2, but on a scale approximately two-thirds of the scale of FIGURE 2, and with the slider shown in its uncoupled position (as in FIGURE 2).
FIGURE 8 represents a top plan View, similar to that shown in FIGURE 7, taken generally on line 8 8 of FIGURE 6, showing the slider in its thread-engaging or coupling position.
FIGURE 9 shows a perspective view of the slider-housing and slider therein, with the slider shown in its uncounling position (as in FIGURE 2).
FIGURE 10 represents a similar perspective view of the slider-housing and slider therein, with the slider shown in its thread-engaging or coupling position (as in FIG- URES 6 and 8).
FIGURE 1l represents a top plan view of the slider.
The syringe, as shown in FIGURES l to 5, inclusive, includes a generally cylindrical transparent glass syringebody or barrel 1, having a glazed cylindrical precision 'bore 2 of suitable length, an enlarged and internallythreaded upper or rear end-portion or head 3 having internal screw-threads 4 whose inner diameter is substantially larger than the inner diameter of the bore 2 of the barrel of the syringe. In the embodiment shown in FIG- URES l to 5 of the drawings, the diameter of the bore 2 is 0.1920", and the wall-thickness of the portion of the glass barrel which is coextensive with the metering bore 2 is of the yorder of 0.100. The lower or front end portion of the glass syringe-body 1 is contracted to form the reduceddiametered tapered needle-receiving tip 5 of suitable length, whose taper has an included angle of the order of 3 degrees and 26 minutes. The length of the tapered portion of the tip 5 is of the order of a quarter of an inch, and its diameter at its small end is of the order of a quarter of an inch, more or less.
The outer tapered surface of the tip 5 is finely ground or provided with a fine-ground finish, so as to form a good frictional as well as duid-tight engagement with the similiarly tapered polished inner bore of needle-hub 6 formed of suitable metal, as for instance, stainless steel or the like. A
The needle-hub 6 includes a tubular needle-receiving eX- tension or cannula-receiving socket 7, into which the hypodermic needle or cannula 8 or the like is telescoped and in which it is firmly secured, in a fluid-tight seal therewith, by swaging or silver-soldering or the like. The interft between the outer finely-ground tapered surface of the tip 5 and the similarly tapered bore of the needle-hub 6 is such as will also provide a gas-tight seal between the needle-hub 6 and the glass tip 5.
A multi-ring or multi-land piston 9 is disposed within the glazed precision bore 2 of the glass syringe barrel 1. The piston 9 is formed of Tellen or Kel-F or other suitable generally chemically inert form-retaining though slightly resiliently deformable synthetic resin which will from an unlubricated non-seizing slidable Huid-sealing contact with a glazed glass surface. The main body of the piston 9, as at 10, is of a diameter slightly less than the inner diameter of the precision bore 2 of the glass barrel 1. At each of the two ends of the piston 9 a relatively narrow cylindrical piston-ring or land 11 is formed integrally with the piston (as indicated in FIGURES 2 and 5 the axial width of each of these piston-rings being generally of the order of 0.040 in the embodiment indicated in FIGURES 1 to 5.
The diameter of the integral piston-rings or lands 11 is slightly larger than the diameter of the bore 2. Thus, for instance, with the bore 2 of the glass barrel having an inner diameter of 0.192, the outer diameter of each of the piston-rings or lands 11 would be of the order between 0.194 to 0.196 in their uncompressed condition, so that when the piston 9 is inserted into the cylindrical bore 2, the integral piston-rings or lands 11 will be slightly compressed and hence will resiliently bear against the cylindrical bore 2 with a relatively high pressure per unit of contact-area thereof.
The chamfered or tapered bore-portion 12 intervening the cylindrical bore 2 and the threaded bore 4, serves to vguide the larger-diametered ring-portions 11 of the piston 9 into the bore 2 and to compress them to the borediameter as the piston 9 is inserted into the glass housing or barrel 1.
A piston-operating stem or rod, designated generally by the numeral 13, is preferably formed of stainless steel and is threaded throughout the major portion 14 of its length, namely, over a portion of its length sufficiently greater than the scale-length, so that such threaded portion 14 can be maintained in threaded engagement with the threaded portion 32 of the coupling-slider 16 throughout the scale-length travel of the piston 9, while the slider 16 is in its coupling position shown in FIGURES 6 and 8.
Thus, with an overall scale-length of 2.109, which also represents the necessary screw-coupled piston-travel, the threaded portion 14 of the piston-stem 13 will have a length more or less of the order of two and three-eighths of an inch.
The piston-operating rod or stem 13 has a tubular inner end 17 whose internally screw-threaded bore portion 18 receives the externally threaded integral stem 19 of the piston 9; these two threaded portions being tightly screwthreaded in relation to each other, `and the stem 19 is secured against being unscrewed from the piston-rod by a thin lm of an epoxy resin intervening the two threaded surfaces. Prior to threadedly telescoping the integral stem 19 of the piston 9 into the threaded bore of the inner end-portion 17 of the stainless-steel piston-rod 13, the externally threaded portion of the stem 19 (formed of Teon, Kel-F or the like) is treated for a minute or so with a composition of anhydrous ammonia and an alkali metal such as sodium, namely, until a Very slight adherent carbon layer is formed on the external threadssuch carbon layer being recognizable by the threads gradually turning from their initially generally white or egg-shell color to a brown color of an increasingly degree of darkness as the treatment is continued. Thereafter the so threaded external threads of the stern 19 are coated with a small amount or thin layer of an epoxy resin, or such epoxy resin may be applied to the internally threaded bore 18 of the terminal-portion 17 of the piston-rod 13. The integral stem 19 of the piston 9 is then screw-threadedly telescoped into the internally threaded bore 18, until it is tight therein, and the epoxy resin is then permitted to set. Any excess of the epoxy resin which may be extruded at 1S may then be scraped of. Other excess of such epoxy resin may lodge between the inner end of the. stem 19 and the inner endA of the threaded bore 18.
The piston-operating stem 13 has a reduced-diametered 'outer end 20, to which a knurled knob or other suitable handle device 21 is detachably secured by a set-screw 22 or the like;
A coupler-housing designated generally by the numeral 23 (FIGURE 9), is provided at the head end of the glass barrel 1 and includes an outer channeled head-like slidereceiving portion `24 and an inner externally-threaded bushing portion 25. The inner bushing portion 25 is screwthreaded into the internally-threaded head portion 3 of the glass syringe body or barrel, with the flat bottom surface 26 of the slider-receiving portion 24 (of the coupler-housing 23) bearing tightly against the upper flat end-surface 27l of the glass barrel 1. The coupler-housing 23 may be formed of a form-retaining synthetic resin such as the chlorinated polyethers, of which a commercially available form is marketed under the trademark Penton by the Hercules Powder Company, or it may be formed of Teflon or Kel-F or the like or other impact-resistant chemically'inert synthetic resin.
The inner cylindrical bore 28 of the tubular bushing portion 25 of the coupler-housing 23 is slightly greater than the uncompressed diameter of the piston rings 11 of the piston 9, so that when the coupler-slider 16 is in its uncoupled position as shown in FIGURES 2, 7 and 9, the entire piston 9 may be fully withdrawn from the glass barrel 1 as well as from the coupler-housing 23 and slider 16; the outer diameter of the threaded portion 14 of the piston-operating stem 13 being slightly smaller than the Y'diameter of the bore 2 of the glass barrel 1.
The head portion 24 of the coupler-housing 23 has a transverse slider-guiding channel 29` therein (FIGURES 1, 6, 9 and 10) with two inwardly extending flanges 30 overlying the longitudinal marginal zones of the couplerslider 16, as indicated in FIGURES 1 and 2 and 6 to l0- whereby the ,coupler-slider 16 is fully confined within the 4- liead portion 24 of the coupler-housing 23 in a manner which permits the slider 16 to be slid transversely of the coupler-housing 23.
The slider 16 is formed of a resilient impact-resistant synthetic resin such as Teon or Kel-F or nylon or the like, and -has two intersecting holes 31 and 32 extending therethrough (FIGURES 7 to 11); the larger hole 31 being of a diameter sufliciently larger than the uncompressed diameter of the piston-rings 11 so as to clear both the screw-thread 14 of` the piston-operating rod 13 as well as the piston-rings 11 with an adequate margin for easy removal, while the smaller hole 32l is threaded and is of a diameter and has its thread of a pitch corresponding to the diameter and pitch of the screw-threaded portion 14 of the piston-operating rod 13; so that when the screw-threaded portion 14 o-f such rod 13 nests within the threaded hole 32, it forms a neat threaded engagement therewith, so that the turning of the rod 13 will move the piston 9 (in the bore 2 of the glass barrel 1) in either direction, as may be desired, according to the direction of turning of the rod 13.
The two holes 31 and 32 intersect each other or overlap each other to such an extent that approximately a segment of the hole 32 is vremoved by such intersection with the hole 31, and so that the threads within the hole 32, between the points 33 (FIGURE 11'), will occupy approximately 245 of a circle, except possibly for the slight interruption at 34 (FIGURE 7).
A small hole 35 is formed through the slider 16, with its axis in the plane in which the axes of the holes 31 and 32 lie, and a thin or narrow slot or slit 36 is formed between the threaded hole 32 and the small hole 35. By this means the threaded hole 32 may be resiliently enlarged or expanded in the direction of the arrows 37 (FIGURE 11); sufficiently to permit the threaded portion 14 of the piston-operating rod 13 to pass through the mouth 33 of theslider when it is desired to move the slider 16 from its uncoupled position (as shown in FIG- URES 2, 6 and 9 into its coupling position (as shown in FIGURES 6, 8 and 10), or vice versa.
The precision-bore 2 of the glass barrel 1 terminates in a flat transverse terminal wall 3S. An axial hole 39, of minimum diameter, extends from the flat bottom 38 of the precision-bore 2 of the barrel 1 to the outer chamfered end 40k of the externally tapered tip 5 of the glass barrel-the hole 39 being of the order of a 1/32" to 1A6" (more or less).
The syringe hereinabove described and illustrated in the accompanying drawings is suitable for sampling and for the injection of the-samples, of both in gas analysis and in isothermal molecular-weight determinations, wherein it may be effectively used as accurate and readily manipulable sampling pipette of high accuracy.
Having described and illustrated exemplifying embodiments of my invention, I claim the following:
1. A syringe, column or the like, including a rigid transparent glass barrel having a glazed cylindrical bore, a piston operatively disposed therein, said piston being formed of a generally chemically inert form-retaining though slightly resiliently deformable synthetic resin forming an unlubricated non-seizing slidable fluid-sealing dry contact with the glazed bore of said glass barrel and said piston having a diameter whichl in its uncompressed. condition is slightly greater than that of the -bore of said glass barrel a piston-rod operatively connected with said piston and extending through and beyond an end of said barrel and having a portion thereof externally screw-threaded for threaded engagement with the belowmentioned coupling-slider, a coupler-housing operatively connected with the end of said barrel through which said piston-rod extends and having a rod-passageway therethrough, generally co-axial with said barrel, through which said piston-rod extends, said rod-passageway being greater than said uncompressed diameter of the piston, said coupler-housing having a slider-guide extending transversely of the axis of said rod-passageway, and a coupling-slider slidably disposed within said slider-guide and confined therein in an axial direction and having a screw-threaded rod-coupling portion for threadedly engaging the threaded portion of the piston-rod and a rod-clearance portion for clearing the threaded portion of the pistonrod, said rod-clearance portion of said coupling-slider being greater than said uncompressed diameter of said piston and permitting the passage of said piston therethrough, sai-d coupling-slider having a rod-coupling position in said slider-guide in which it threadedly engages the threaded portions of the piston-rod and having an uncoupling position in which it clears the threaded portion of the piston-rod, and said couplingslider being arranged to permit it to be moved in said slider-guide from either of its said two positions to the other, thereby to permit the screw-controlled displacement of the piston in either direction in accurate small increments when the coupling-slider is in its coupling position and to permit the displacement of the piston in either direction, free of said; screw-threads, when the coupling-slider is in its uncoupling position, and to permit the piston to be fully withdrawn through said rod-clearance portion of the coupling-slider and through said coupler-housing.
2. A device according to claim 1, in which the coupling-slider is internally screw-threaded.
3. A device according to claim 1, in which the coupling-slider has two intersecting holes therethrough with their axes generally parallel with each other and with the axis of the barrel, one of said holes being a rod-clearance hole and the other of said holes being an internally threaded rod-coupling hole.
4. A device according to claim 1, in which the pistonrod limits the travel of the coupling-slider within the slider-guide.
5. A device according to claim 2, in which the pistonrod limits the travel of the coupling-slider within the slider-guide.
6. A device according to claim 2, in which the circumference of the internal screw-thread of the couplingslider is substantially less than 360.
7. A device according to claim 6, in which there is a gap of substantially less than 180 in the circumference of the internal screw-thread of the coupling-slider, through which the screw-t-hreaded portion of the pistonrod may enter into threaded engagement with such screwthread of the coupling-slider and through which it may exit from such screw-threaded engagement.
S. A device according to claim 7, in which the gap in the screw-thread of the slider is resiliently expandable by the ingress and egress of the screw-threaded portion of the piston-rod therethrough.
9. A device according to claim 3,V in which the intersection of the two holes forms a gap in the internallythreaded hole of substantially less than 180.
10. A device according to claim 9, in which the gap in the screw-threaded hole is expandable by the ingress and egress therethrough of the threaded portion of the piston-rod.
11. A syringe, column or the like, including a rigid transparent glass barrel having a glazed cylindrical bore and a discharge hole of substantially smaller diameter eX- tending from the inner end of said bore to the exterior of the barrel and said barrel having its other end screwthreaded, a piston operatively disposed within said bore formed of a generally chemically inert and generally form-retaining though slightly resiliently deformable synthetic resin capable of forming an unlubricated nonseizing slidable fluid-sealing dry contact with the glazed surface of said bore, said piston having an integral piston-ring in proximity of each of its two ends, said piston-rings being of small axial extent and of a diameter which is larger than the diameter of its body portion intermediate the piston-rings thereof and which is sufficiently larger than the bore of the barrel in the uncompressed condition thereof so as to be resiliently compressed when the piston is operatively disposed in the bore of the barrel, a piston-rod having its inner end afxed to the piston and having a portion thereof externally screw-threaded and having an end thereof extending beyond the barrel and beyond the below-mentioned coupler-housing and rod-coupler, a coupler-housing formed of an impact-resistant synthetic resin screw-threadedly mounted to the threaded end of the glass barrel and having a piston-clearing passageway therethrough to permit the piston to be fully withdrawn, a screw-threaded rod-coupler movably mounted to the coupler-housing and arranged to be optionally moved into a coupling position in which its thread interengages the thread of the piston-rod and into an uncoupling position in which its thread is out of engagement with the thread of the piston-rod, said rod-coupler being arranged to provide a radial clearance for the piston when the rod-coupler is in its uncoupling position for permitting the piston to be fully withdrawn in an axial direction, and a handle carried by the outer extending end of the piston-rod.
12. A syringe, column or the like according to claim 11, in which the piston-rod and piston are screw-threadedly telescoped to each other.
13. A syringe, column or the like according to claim 12, in which the screw-threadedly telescoped portions of the piston-rod and piston are bonded to each other by a film of bonding resin intervening the juxtaposed thread surfaces thereof.
14. A device according to claim 11, in which the coupler-housing includes a channel transversely of the axis of the barrel and in which the rod-coupler is slidably disposed within and guided by said channel.
References Cited UNITED STATES PATENTS 949,163 2/ 1910 Stapley 222-390 1,624,138 4/ 1927 Jorgensen et al 222--390 2,745,575 5/1956 Spencer 222-390 X 3,146,142 8/1964 Maly 285-423 X 3,153,496 10/ 1964 Johnson 222-386 3,212,685 10/ 1965 Swan et al. 222-386 N. L. STACK, Assistant Examiner,