US3512944A - Burette with removable stopcock formed of synthetic resin - Google Patents

Burette with removable stopcock formed of synthetic resin Download PDF

Info

Publication number
US3512944A
US3512944A US667460A US3512944DA US3512944A US 3512944 A US3512944 A US 3512944A US 667460 A US667460 A US 667460A US 3512944D A US3512944D A US 3512944DA US 3512944 A US3512944 A US 3512944A
Authority
US
United States
Prior art keywords
burette
shell
stopcock
plug
synthetic resin
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US667460A
Inventor
Michael A Craig
Walter I Holms
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Corning Glass Works
Original Assignee
Corning Glass Works
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Corning Glass Works filed Critical Corning Glass Works
Application granted granted Critical
Publication of US3512944A publication Critical patent/US3512944A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
    • B01L3/56—Labware specially adapted for transferring fluids
    • B01L3/567—Valves, taps or stop-cocks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
    • B01L3/02—Burettes; Pipettes
    • B01L3/0203—Burettes, i.e. for withdrawing and redistributing liquids through different conduits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K27/00—Construction of housing; Use of materials therefor
    • F16K27/06—Construction of housing; Use of materials therefor of taps or cocks
    • F16K27/065—Construction of housing; Use of materials therefor of taps or cocks with cylindrical plugs

Definitions

  • the present invention relates to the construction of laboratory burettes for the delivery and measurement of fluids.
  • Such burettes conventionally comprise a glass cylinder having markings thereon to indicate volumetric gradations and a stopcock separating the cylinder from the delivery tip of the burette.
  • the cylinder, the outer shell of the stopcock and the delivery tip are conventionally formed as an integral glass body, and a stopcock plug having a fluid-flow channel extending therethrough is rotatably mounted in the stopcock shell.
  • Burettes formed in the conventional manner are expensive to manufacture, and replacement costs are high, inasmuch as damage to either the cylinder, the stopcock shell or the delivery tip requires replacement of three integral portions. Furthermore, it is necessary that the inner surface of the glass stopcock shell be ground, which adds to the expense of the burette.
  • a further object is the provision of a burette which permits substitution of graduated cylinders, or other fluid containers, of varying capacities, without the necessity for changing the other components of the burette.
  • a burette comprising a fluid container and a delivery tip joined by a stopcock held in removable interference-fitted engagement therewith, both the shell and the plug of the stopcock being formed of a chemically inert synthetic resin. Due to the separability of the components of the burette, breakage of either the fluid container or the delivery end does not necessitate replacement of the stopcock, and easy substitution of parts may be effected.
  • the drawing is a longitudinal sectional view of a burette according to the invention.
  • a burette constructed according to the preferred embodiment of the invention comprises glass graduated cylinder 10, stopcock 12 and glass delivery tip 14.
  • Stopcock 12 comprises shell 16 and cylindrical plug 18 rotatably mounted in bore 19 of the shell ice and maintained in position by means of rubber O-rings 20. Both the shell and the plug are formed of polytetrafiuoroethylene, and a fluid-tight seal is maintained between the plug and thebore of the shell.
  • Shell channel 22 extends through shell 16 in a longitudinal direction and forms a fluid-flow channel from graduated cylinder 10 to delivery tip 14 when plug 18 is in the illustrated position with plug channel 24 aligned with the shell channel.
  • Plug 18 is rotatable by means of handle 25.
  • Shell 16 has at its upper end a cylindrical male portion 26 which extends into the lower end of graduated cylinder 10 and is in fluid-tight interference-fitted engagement with the inner surface thereof.
  • a cylindrical female portion 27 At the lower end of plug 16 is a cylindrical female portion 27 having an inside diameter smaller than the outside diameter of male portion 26.
  • the upper end of delivery tip 14 projects into portion 27 and holds the delivery tip in fluid-tight interference-fitted engagement.
  • Stopcock shell 16 and plug 18 may be formed of other chemically inert, nonporous, nonabsorbent relatively hard and generally form-retaining wax-like synthetic resins which are slightly elastic under low stress and which are self-lubricating with respect to the surfaces of similar materials.
  • Other such materials in addition to polytetrafiuoroethylene are polystyrene and polytrifluorochloroethylene.
  • a burette assembly for the delivery of fluids comprising:
  • a container for fluids having a cylindrical portion at the lower end thereof
  • tubular delivery tip having a cylindrical portion at the upper end thereof
  • a stopcock removably interposed between said container and delivery tip, comprising a shell having a bore extending therethrough, a plug rotatably mounted in said bore and means for rotating said plug in said shell, said shell and said plug having channels extending therethrough so as to form a continuous channel for fluid flow between said container and said delivery tip at one position of said plug in said shell, wherein the improvement comprises:
  • said shell and said plug of said stopcock being formed of a chemically inert, nonporous, nonabsorbent, relatively hard and generally form-retaining wax-like synthetic resin which is slightly elastic under low stress and which is self-lubricating with respect to surfaces of similar materials;
  • said stopcock shell including a cylindrical male portion on its upper end positioned within the cylindrical portion of said container in fluidtight removable interference-fitted engagement with inner surface portion of said container;
  • said stopcock shell further including, a cylindrical female portion on its lower end, the cylindrical upper end of said delivery tip positioned within said cylindrical female portion in fluidtight removable interference-fitted engagement therewith, a lower section of said female portion protectively overlying the upper end portion of said delivery tip; the outside diameter of said male portion differing from the inside diameterof said female portion; (d) said rotatably mounted cylindrical plug being means of retaining rings secured to said plug,

Landscapes

  • Health & Medical Sciences (AREA)
  • Clinical Laboratory Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Closures For Containers (AREA)
  • Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)

Description

M y 9, 1970 M. A. CRAIG ETAL 3,512,944
BURETTE WITH REMOVABLE STOPCOCK FORMED OF SYNTHETIC RESIN Filed Sept. 13, 1967 I! I!!! W! WI BY WALTER l. HOLMS WM p 9 M AGENT United States Patent 3,512,944 BURETTE WITH REMOVABLE STOPCOCK FORMED OF SYNTHETIC RESIN Michael A. Craig, Corning, and Walter I. Holms, Elmira, N.Y., assignors to Corning Glass Works, Corning, N.Y., a corporation of New York Filed Sept. 13, 1967, Ser. No. 667,460 Int. Cl. B01l 3/02; F16]; 5/04 US. Cl. 23-292 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The present invention relates to the construction of laboratory burettes for the delivery and measurement of fluids. Such burettes conventionally comprise a glass cylinder having markings thereon to indicate volumetric gradations and a stopcock separating the cylinder from the delivery tip of the burette. The cylinder, the outer shell of the stopcock and the delivery tip are conventionally formed as an integral glass body, and a stopcock plug having a fluid-flow channel extending therethrough is rotatably mounted in the stopcock shell.
Burettes formed in the conventional manner are expensive to manufacture, and replacement costs are high, inasmuch as damage to either the cylinder, the stopcock shell or the delivery tip requires replacement of three integral portions. Furthermore, it is necessary that the inner surface of the glass stopcock shell be ground, which adds to the expense of the burette.
Accordingly, it is an object of the present invention to provide a novel burette in which construction and replacement costs are minimized.
A further object is the provision of a burette which permits substitution of graduated cylinders, or other fluid containers, of varying capacities, without the necessity for changing the other components of the burette.
SUMMARY OF THE INVENTION The objects of the invention are accomplished by the provision of a burette comprising a fluid container and a delivery tip joined by a stopcock held in removable interference-fitted engagement therewith, both the shell and the plug of the stopcock being formed of a chemically inert synthetic resin. Due to the separability of the components of the burette, breakage of either the fluid container or the delivery end does not necessitate replacement of the stopcock, and easy substitution of parts may be effected.
BRIEF DESCRIPTION OF THE DRAWING The drawing is a longitudinal sectional view of a burette according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, a burette constructed according to the preferred embodiment of the invention comprises glass graduated cylinder 10, stopcock 12 and glass delivery tip 14. Stopcock 12 comprises shell 16 and cylindrical plug 18 rotatably mounted in bore 19 of the shell ice and maintained in position by means of rubber O-rings 20. Both the shell and the plug are formed of polytetrafiuoroethylene, and a fluid-tight seal is maintained between the plug and thebore of the shell. Shell channel 22 extends through shell 16 in a longitudinal direction and forms a fluid-flow channel from graduated cylinder 10 to delivery tip 14 when plug 18 is in the illustrated position with plug channel 24 aligned with the shell channel. Plug 18 is rotatable by means of handle 25. Shell 16 has at its upper end a cylindrical male portion 26 which extends into the lower end of graduated cylinder 10 and is in fluid-tight interference-fitted engagement with the inner surface thereof. At the lower end of plug 16 is a cylindrical female portion 27 having an inside diameter smaller than the outside diameter of male portion 26. The upper end of delivery tip 14 projects into portion 27 and holds the delivery tip in fluid-tight interference-fitted engagement.
Stopcock shell 16 and plug 18 may be formed of other chemically inert, nonporous, nonabsorbent relatively hard and generally form-retaining wax-like synthetic resins which are slightly elastic under low stress and which are self-lubricating with respect to the surfaces of similar materials. Other such materials in addition to polytetrafiuoroethylene are polystyrene and polytrifluorochloroethylene.
While this invention has been described in connection with possible forms or embodiments thereof, it is to be understood that the present disclosure is illustrative rather than restrictive and that changes or modifications may be resorted to without departing from the spirit of the invention.
We claim:
1. A burette assembly for the delivery of fluids, said assembly comprising:
a container for fluids having a cylindrical portion at the lower end thereof,
a tubular delivery tip having a cylindrical portion at the upper end thereof, and
a stopcock removably interposed between said container and delivery tip, comprising a shell having a bore extending therethrough, a plug rotatably mounted in said bore and means for rotating said plug in said shell, said shell and said plug having channels extending therethrough so as to form a continuous channel for fluid flow between said container and said delivery tip at one position of said plug in said shell, wherein the improvement comprises:
(a) said shell and said plug of said stopcock being formed of a chemically inert, nonporous, nonabsorbent, relatively hard and generally form-retaining wax-like synthetic resin which is slightly elastic under low stress and which is self-lubricating with respect to surfaces of similar materials;
(b) said stopcock shell including a cylindrical male portion on its upper end positioned within the cylindrical portion of said container in fluidtight removable interference-fitted engagement with inner surface portion of said container;
(c) said stopcock shell further including, a cylindrical female portion on its lower end, the cylindrical upper end of said delivery tip positioned within said cylindrical female portion in fluidtight removable interference-fitted engagement therewith, a lower section of said female portion protectively overlying the upper end portion of said delivery tip; the outside diameter of said male portion differing from the inside diameterof said female portion; (d) said rotatably mounted cylindrical plug being means of retaining rings secured to said plug,
with the inner side surfaces of said retaining rings contacting the outside surface of said stopcock shell. 2. The burette assembly of claim 1 wherein said shell and said plug are comprised of polyetetrafiuoroethylene. 3. The burette assembly of claim 1 wherein the inside diameter of said stopcock shell female portion is smaller than the outside diameter of said male portion thereof.
4. The burette assembly of claim 1 wherein said retaining rings are rubber O-rings.
Refer-ences Cited UNITED STATES PATENTS 6/1961 Gilmont 23-292XR 6/1967 Phillips 23-292 MORRIS o. WOLK, Primary Examiner R. M. REESE, Assistant Examiner 7 US. Cl. X.R-. 251368
US667460A 1967-09-13 1967-09-13 Burette with removable stopcock formed of synthetic resin Expired - Lifetime US3512944A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US66746067A 1967-09-13 1967-09-13

Publications (1)

Publication Number Publication Date
US3512944A true US3512944A (en) 1970-05-19

Family

ID=24678312

Family Applications (1)

Application Number Title Priority Date Filing Date
US667460A Expired - Lifetime US3512944A (en) 1967-09-13 1967-09-13 Burette with removable stopcock formed of synthetic resin

Country Status (3)

Country Link
US (1) US3512944A (en)
BE (1) BE720849A (en)
FR (1) FR1579885A (en)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3632119A (en) * 1969-12-29 1972-01-04 Chemplast Inc Resilient sealing means for joint between elements having different coefficients of expansion
US3782686A (en) * 1971-06-18 1974-01-01 Cowie Scient Ltd Taps
US3799411A (en) * 1971-10-20 1974-03-26 Chemplast Inc Resilient sealing means for joint between elements having different coefficients of expansion
US3889712A (en) * 1972-12-01 1975-06-17 Robert E Fields Valves
US4072291A (en) * 1975-08-22 1978-02-07 Entek Corporation Rotary valve with spring biased valve member
US4169578A (en) * 1975-08-22 1979-10-02 Entek Corporation Rotary valve with spring biased valve member
US4744390A (en) * 1987-10-14 1988-05-17 Dresser Industries, Inc. Plastic valve
US4750373A (en) * 1987-01-22 1988-06-14 Shapiro Justin J Adjustable volume, pressure-generating pipette sampler
US4794944A (en) * 1987-10-14 1989-01-03 Dresser Industries, Inc. Plastic valve
EP0410898A2 (en) * 1989-07-27 1991-01-30 Terumo Kabushiki Kaisha Multi-way cock
US5219096A (en) * 1992-04-17 1993-06-15 Wing Virgil N Leakproof self defense liquid squirt gun
US5240397A (en) * 1991-10-01 1993-08-31 Biomedical Polymers, Inc. Injection molding mechanism for forming a monolithic tubular pipette
US5419468A (en) * 1992-07-17 1995-05-30 Brother Kogyo Kabushiki Kaisha Developing toner supply device with detachable toner cartridge and toner supply shielding member
US5944259A (en) * 1997-08-06 1999-08-31 Flexible Products Company Spray gun with improved seal
CN102575783A (en) * 2009-07-20 2012-07-11 戴维·R·邓肯 Multi-port stopcock valve and flow designating system
CN105665050A (en) * 2016-03-10 2016-06-15 湖南城市学院 Liquid transfer tube

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2988321A (en) * 1955-04-04 1961-06-13 Manostat Corp Fluid flow control devices
US3323874A (en) * 1965-02-09 1967-06-06 Edwin D Phillips Laboratory accessory equipment

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2988321A (en) * 1955-04-04 1961-06-13 Manostat Corp Fluid flow control devices
US3323874A (en) * 1965-02-09 1967-06-06 Edwin D Phillips Laboratory accessory equipment

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3632119A (en) * 1969-12-29 1972-01-04 Chemplast Inc Resilient sealing means for joint between elements having different coefficients of expansion
US3782686A (en) * 1971-06-18 1974-01-01 Cowie Scient Ltd Taps
US3799411A (en) * 1971-10-20 1974-03-26 Chemplast Inc Resilient sealing means for joint between elements having different coefficients of expansion
US3889712A (en) * 1972-12-01 1975-06-17 Robert E Fields Valves
US4072291A (en) * 1975-08-22 1978-02-07 Entek Corporation Rotary valve with spring biased valve member
US4169578A (en) * 1975-08-22 1979-10-02 Entek Corporation Rotary valve with spring biased valve member
US4750373A (en) * 1987-01-22 1988-06-14 Shapiro Justin J Adjustable volume, pressure-generating pipette sampler
US4794944A (en) * 1987-10-14 1989-01-03 Dresser Industries, Inc. Plastic valve
US4744390A (en) * 1987-10-14 1988-05-17 Dresser Industries, Inc. Plastic valve
EP0410898A2 (en) * 1989-07-27 1991-01-30 Terumo Kabushiki Kaisha Multi-way cock
EP0410898A3 (en) * 1989-07-27 1991-07-24 Terumo Kabushiki Kaisha Multi-way cock
US5240397A (en) * 1991-10-01 1993-08-31 Biomedical Polymers, Inc. Injection molding mechanism for forming a monolithic tubular pipette
US5219096A (en) * 1992-04-17 1993-06-15 Wing Virgil N Leakproof self defense liquid squirt gun
US5419468A (en) * 1992-07-17 1995-05-30 Brother Kogyo Kabushiki Kaisha Developing toner supply device with detachable toner cartridge and toner supply shielding member
US5944259A (en) * 1997-08-06 1999-08-31 Flexible Products Company Spray gun with improved seal
CN102575783A (en) * 2009-07-20 2012-07-11 戴维·R·邓肯 Multi-port stopcock valve and flow designating system
CN102575783B (en) * 2009-07-20 2014-07-30 戴维·R·邓肯 Multi-port stopcock valve and flow designating system
CN105665050A (en) * 2016-03-10 2016-06-15 湖南城市学院 Liquid transfer tube

Also Published As

Publication number Publication date
FR1579885A (en) 1969-08-29
BE720849A (en) 1969-03-13

Similar Documents

Publication Publication Date Title
US3512944A (en) Burette with removable stopcock formed of synthetic resin
US5485681A (en) Swivel type dipstik
GB1158159A (en) Cervical Canal Specimen Collector
ATE49057T1 (en) LIQUID CHROMATOGRAPHY COLUMN.
US2970561A (en) Fluid flow indicators
US4760747A (en) Liquid sampling and measuring device
US2566970A (en) Expansion gauge
US2261027A (en) Guard device for pressure-responsive instruments
US4222412A (en) High pressure valve for chromatography
US2101165A (en) Pitot tube
US3183713A (en) Flowmeter
US3541858A (en) U-tube manometer with shipping seal
US2322660A (en) Device for gauging liquids in containers under pressure
US2642258A (en) Pressure-tight stopcock adapter
GB1315973A (en) Valves for containers
JPS5236057A (en) Flow meter
US3548508A (en) Center locater device
US2467599A (en) Colorimetric vessel
US4524618A (en) Glass sight gauge for high pressure vessel
US2674881A (en) Depth indicator for boats
US4584871A (en) Device and method for testing differential pressure measuring passageways
US3091124A (en) Measuring pipet
JPS57158514A (en) Fluidity indicator and water distributor
US5111588A (en) Level vial
US2356347A (en) Device for measuring liquid level in containers