US 3628405 A
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States Patent Martin Fleisher 45 Knott Drive, Glen Cove, N.Y. 11542 Mar. 2, 1970 Dec. 21, 1971 Inventor Appl. No. Filed Patented STOPPER REMOVING IMPLEMENT 7 Claims, 3 Drawing Figs.
U.S. Cl Int. Cl B671) 7/06 Field of Search 81/3.42,
References Cited UNITED STATES PATENTS 1 1/1949 Deschenes 2,589,051 3/1952 Carter 2,593,091 4/1952 Belpedio Primary Examiner- Robert C. Riorclon Assistant Examiner-Roscoe V. Parker, Jr. Attorney-Martin Novack ABSTRACT: Apparatus for removing a resilient stopper which protrudes substantially from the rim of a test tube. An elongated base member having an aperture therein is provided. A stopcap element covers the aperture on one side of the member and a blade element is slidably mounted on the other side. in operation, the stopper is inserted in the aperture and the blade element engages the least protruding portion of the stopper.
PATENTEU um! I97! 3,628,405
- ARTIN FLEISHER ATTORNEY STOPPER REMOVING IMPLEMENT BACKGROUND OF THE INVENTION This invention relates to ejection implements and, more particularly, to an implement for removing a resilient stopper from a test tube.
The modern medical laboratory utilizes large numbers of scaled test tubes for a variety of purposes. One particular type, which is widely used for blood sampling, is a glass test tube which is vacuum sealed with a stopper made of a resilient material such as rubber. The stopper generally protrudes slightly from the lip of the test tube. One end of a hypodermic needle is inserted in a patients blood vessel and the other end is introduced to the test tube by piercing the stopper. Blood is drawn into the test tube by virtue of a pressure differential and the needle is then withdrawn from the test tube.
When the blood sample is to be tested the stopper is removed from the test tube. This operation is generally performed by a laboratory technician who, at a given time, may be required to remove the stoppers from numerous test tubes. It is present practice for the technician to hold the test tube in one hand and manipulate the stopper with the fingers of his other hand to effect removal. This is often a troublesome procedure. The test tube, which had originally been vacuum sealed, had required a tight fitting stopper for proper maintenance of the vacuum. The stopper is therefore not quickly and easily removable with human fingers, even when the fingers are clean and dry. In addition, there is a danger of spilling the blood sample since an abruptly pulled stopper can cause a jerking motion of the test tube. This danger is especially hazardous when the blood sample is taken from an infected test animal or a hepatitis patient.
In the manufacture of vacuum sealed test tubes it is conventional practice to alleviate the stopper removal problem somewhat by precoating each stopper with a lubricant such as glycerol. Even precoated stoppers are not easily removed, however. Furthermore, the precoating procedure requires an additional manufacturing step with its associated expense.
SUMMARY OF THE INVENTION The present invention is directed to an implement which facilitates the removal of a resilient stopper that protrudes slightly from the lip of a test tube. An elongated base member having top and bottom sides is provided. The base member has a circular aperture for receiving the protruding portion of the stopper through its bottom side. A stopcap element is affixed to the top side of the member and substantially covers the aperture, this element receiving the topmost surface of the stopper. In addition, a blade is provided which is slidably mounted on the bottom side of the member, the edge of the blade being normally positioned adjacent the aperture. The blade edge is slidable into the area below the aperture to engage the least protruding portion of the stopper and apply a pressure thereto. The stopper can then be easily removed with a lifting or prying motion of the implement. In a preferred embodiment of the invention the stopcap element extends upwardly from the top surface of the member by a predetermined distance. This distance plus the thickness of the member is set substantially equal to the distance by which the stopper protrudes from the test tube. This insures that the blade edge grips the stopper at its point of least protrusion from the test tube.
Further features and objects of the invention will be better understood from the following detailed description when taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of the apparatus of the invention.
FIG. 2 is a bottom view of the invention.
FIG. 3 is a middle cross-sectional view of the invention shown as operating on a test tube stopper.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings there are shown views of an implement in accordance with the invention. An elongated rigid base member 20 is provided with a circular aperture 21 which is proportioned to receive the protruding end of a test tube stopper. Base member 20 is preferably flat and formed of a sturdy material such as a rigid plastic. Affixed to the top side of the base member is a stopcap element 22 which covers the aperture 21. Stopcap element 22 may be affixed, for example, with an epoxy or may be a molded part. of the base member. A flat blade 23 having a rounded serrated edge 2d is slidably mounted on the bottom side of member 20. Blade 23 is mounted on member 20 by rivet 25 and screw 26 which are each movable laterally in the slots .27 and 28. Screw 26 secures the blade 23 to an actuator 29 which is positioned on the top side of member 20. A return spring 30 is coupled between screw 26 and one end of the slot 28 and biases blade 23 to its normal position with edge 24 adjacent but not overlapping aperture 21.
In operation, the implement is held in one hand and the protruding portion of a test tube stopper is placed in aperture 21 (FIG. 3) with the top of the stopper resting against stopcap element 22. Actuator 29 is moved toward stopcap 22 with a finger or thumb thereby sliding blade 23 against the least protruding portion of the stopper. The serrated edge 2% grips the stopper which is then removed from the test tube with a prying motion of the member 20.
It is preferred that the height h of the stopcap 20 plus the thickness t of member 20 be substantially equal to the distance d by which the test tube stopper protrudes from the test tube. This insures that the blade edge 24 grips the resilient stopper at its point of least protrusion from the test tube; i.e., directly above the test tube lip. The removal operation has been found to be highly efficient when this condition is met. The protrusion distance d is substantially constant for the products of an individual vacuum test tube manufacturer. Therefore, the dimension h+t can be chosen for compatibility with a given manufacturers product.
As noted above, it is conventional practice to coat resilient test tube stoppers, and especially those used in vacuum test tubes, with a lubricant such as glycerol. The present invention has been found to improve the efficiency of stopper removal to an extent that obviates the need for such coatings.
What is claimed is:
I. An implement for removing a resilient tube stopper which protrudes substantially from the rim of a test tube comprising:
a. an elongated base member having; top and bottom sides,
said member having a circular aperture therein for receiving the protruding portion of said stopper through the bottom side of said member;
b. a stopcap affixed to the top side of said member and sub stantially covering said aperture, said element receiving the topmost surface of said stopper; and
c. a blade slidably mounted on the bottom side of said member, said blade having an edge normally adjacent said aperture and slidable into the area of said aperture to engage the least protruding portion of said stopper.
2. The implement as defined by claim I wherein said stopcap element extends upwardly from the top surface of said member by a predetermined distance, said distance plus the thickness of said member being substantially equal to the distance by which said stopper protrudes from said test tube.
3. The implement as defined by claim I further comprising an actuating element slidably mounted on the top side of said member, said actuating element being coupled to said blade element.
4. The implement as defined by claim 3 further comprising biasing means coupled between said blade element and said member, said means biasing said blade: in its normal position adjacent said aperture.
5. The implement as defined by claim 4 wherein said biasing cap element extends upward; from the top surface of said means is a spring. member by a predetermined distance, said distance plus the 6. The implement as defined by claim 5 wherein said blade thickness of said member being Subsmmiauy equal to the h a d d serrated d distance by which said stopper protrudes from said test tube.
7. The implement as defined by claim 6 wherein said stop- 5 Avm IOIOI (H71