US3449959A - Sample container for automatic sampling apparatus - Google Patents

Description

June 17, 1969 J. F. GRIMSHAW SAMPLE CONTAINER FOR AUTOMATIC SAMPLING APPARATUS Sheet Filed June 27, 1966 FIG. 2

F GRIMSHAW INVENTOR. W

JAMES ATTORNEY June 17, 1969 J. F. GRIMSHAW 3,449,959 SAMPLE CONTAINER FOR AUTOMATIC SAMPLING APPARATUS Filed June 27, 1966 Sheet 2 of 3 J I: M f I5 i si mml w fl'llmumm...... I

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' JAMES F. GRIMSHAW INVENTOR.

Byway M ATTORNEY June .17, 1969 J. F. GRIMSHAW' 3,449,959

TOMATIC SAMPLING APPARATUS SAMPLE CONTAINER FOR AU Sheet Filed June 27, 1966 FIG. 6

JAMES F. GRIMSHAW INVENTOR.

BY W

ATTORNEY 3,449,959 SAMPLE CONTAINER FOR AUTOMATIC SAMPLING APPARATUS James F. Grimshaw, Rochester, N.Y., assignor to Bausch & Lomb Incorporated, Rochester, N.Y., a corporation of New York Filed June 27, 1966, Ser. No. 560,760 Int. Cl. G01n 1/10 U.S. Cl. 73-423 4 Claims ABSTRACT OF THE DISCLOSURE An apparatus for supplying samples to an analyzer wherein sample containers are mounted on a turntable which is turned so that samples may be sequentially removed by a probe. The disclosure relates to a particular shaped container and a particular mechanism for manipulating the probe.

This invention relates to containers for receiving liquid samples and more particularly to containers for automatic mixing apparatus adapted to receive small volumes of liquid samples and shaped to cooperate with withdrawal means to provide for the maximum removal of the liquid sample therein.

In certain types of analytical procedures, large numbers of routine determinations must be carried out. Particularly applicable are those employed in biochemical, physiological and medical laboratories where materials such as blood serum, spinal fluids, tissue serum, urine, or other materials are tested and/or analyzed. Such tests are particularly suited for automation because the analytical procedures are repeated a large number of times.

In accordance with many of these procedures, a measurement is made by a suitable sensing device capable of measuring a physical or chemical property which is indicative of the analytical results to be found. For example, many procedures call for the accurate mixing of a predetermined volume of a test sample with other reagents to develop a reaction resulting in a change in optical density in an amount depending upon the concentration of a constituent in the test sample. Apparatus designed to automatically provide the mixing sequence generally includes a plurality of sample containers adapted to receive liquids to be tested. The sample containers are sequentially moved to a withdrawal position wherein a transfer device including a probe educts a predetermined volume of the test sample.

In many cases, the available amount of test samples is small, such as in the case of spinal fluids, etc., requiring efiicient processing of the sample. This presents a particular problem in automated apparatus wherein it is highly desirable to transfer substantially all of the liquid in the container so that the amount of fluid required per test can be minimized.

It is therefore an object of this invention to provide a new and improved sample container for automatic analyzing apparatus.

It is also an object of this invention to provide a new and improved sample container for automated apparatus adapted to cooperate with a transfer device for the efficient transfer of liquid therein.

It is still a further object of this invention to provide a new and improved sample container for automated apparatus particularly adapted to receive small volumes of test sample and cooperates with a transfer device for the maximum transfer thereof.

The sample container of the invention is adapted to be used with automatic sampling apparatus including a carrier means for receiving a plurality of the sample con- United States Patent Office 3,449,959 Patented June 17, 1969 tainers and moves the containers in a step by step motion and includes means for sequentially moving an intake probe into and out of the plurality of containers for withdrawing the contents therein during dwell periods. The sample containers include a top portion having an opening therein for receiving the probe, an elongated bottom portion that is substantially smaller than the opening in the top portion and side portions connecting the top and bottom portions to form a highly tapered cavity for receiving liquid samples. The containers are mounted on the carrier means so that the probe moves into the containers to engage the bottom portion and the larger dimension of the bottom portion lies along the path of movement of the carrier means. The highly tapered cavity provides for the maximum withdrawal of the liquid sample therein, thereby providing for the efficient use of smaller test samples. The elongated bottom portion provides for a wide degree of tolerance for the step by step motion of the carrier means.

A further feature of the invention includes the cooperation of the highly tapered cavity to guide a gravity biased probe to engagement with the bottom portion when said probe or container is misaligned.

The novel features which are considered to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawings in which:

FIGURE 1 is a plan View of an automatic sampling apparatus adapted to be used in conjunction with the sample container including the invention.

FIGURE 2 is a side view of the sampling apparatus of FIGURE 1.

FIGURE 3 is an enlarged side view of the transfer device of FIGURE 1 and its relation to a sample container.

FIGURE 4 is an electrical schematic diagram for controlling the operation of the automatic sampling apparatus.

FIGURE 5 is a top view of the sample container for the automatic sampling apparatus of FIGURE 1.

FIGURE 6 is a perspective view of the sample container of FIGURE 5.

FIGURE 7 is a front view of the sample container of FIGURE 5.

FIGURE 8 is a side view of the sample container of FIGURE 5.

Referring to FIGURES 1, 2, and 3, an automatic sampling system includes a circular turntable 10 mounted to rotate about a shaft 12. Two groups of holes are formed in concentric circular rows 14 and 16 about the shaft 12. The holes in the circular row 14 are unsymetrically shaped about the row 14 (as illustrated by the hole 15) and include a curved portion and several connecting straight portions. The holes receive a plurality of small containers 18 (including test samples to be analyzed) having an outer shape to fit in the unsymmetrical hOles in a predetermined aligned manner. The holes in the circular row 16 are in fixed radial relation with the containers 18 in row 14 and receive a plurality of cuvettes 19 (one for each container 18). The cuvettes 19 are adapted to receive a portion of test samples mixed with a plurality of reagents.

The turntable shaft 12 is coupled through the gears 20 and 22 to a motor 24 (FIGURE 2), A timing gear 26 is also coupled to the shaft 12, the teeth of which are adapted to engage the roller 28 of a snap action switch 30 to provide an indication when the turntable 10 has rotated a preset angle. The motor 24, by way of example, can be a commercially available slow speed stepping motor that can be energized momentarily to close the switch and then held energized (sealed in) by the switch 30 until the turntable 10 has rotated a required angle. Each time the motor 24 is energized a new sample container 18 and cuvette 19 are positioned in a sampling site (illustrated by a dashed block 32).

A probe 34 is mounted to form a portion of an automatic sampling mechanism or transfer device adapted to be connected to suitable pump mechanism to remove a preset volume of the test sample from the containers 18 and translate the preset volume of the test sample along with a given volume of a second reagent into a corresponding cuvette 19 in the sampling site 32. Probe 34 is a hollow tube extending through a movable probe arm 36. The movable arm 36 is pivotally coupled to a sliding member 38 through a pivot connection 40 and includes an elongated guide slot 42 (shown dashed) formed therein with a pin 44 (shown dashed) extending across the slot (FIGURES 1 and 3). The guide slot 42 fits over a stationary cam 46 having a triangular shaped surface that engages the pin 44 to control the vertical motion of the arm 36.

The slidable member 38 is mounted on a circular cam 48 through a cam drive shaft 50 (shown dashed) and held in place by a cap 52. The cam 48 includes a circular groove 54 (FIGURE 1) formed eccentric with the drive shaft 50. A guide pin 56 extends through the slidable member 38 into the circular groove 54. The shaft 50 passes through a slot 58 formed in the slidable member 38 (FIGURE 1) and extends through and makes connection with the circular cam 48 at a point off center.

The cam 48 is rotated by the shaft 50 to slide along a base 60 in a counterclockwise direction (as indicated by the arrow 62, FIGURE 1) so that the slidable member 38 slides back and forth (in the direction as indicated by the arrows 64, FIGURE 3) causing the pin 44 to ride along the surfaces 68 and 70 of the stationary cam 46 and forcing the arm 36 to follow a curved path having the form of an are. For example, if the arm 38 is forced to move in a direction towards the turntable 10, the pin 44 rides up along the surface 68 causing the arm 36 to tilt upwards above the container 18 in circular row 14 (as shown in phantom in FIGURE 3 After the pin has passed the peak in the cam 46 (with the arm still moving in the same direction) the pin 44 slides along the surface 70 causing the arm to be tilted down toward the turntable 10 so that the probe 34 dips into a sample container 18 in the sampling site 32 providing a first operative position for withdrawing the test sample (FIGURE 3) As the cam 48 is rotated further, the direction of movement of the slider 38 and the arm 36 reverses, forcing the pin 44 to slide back up the surface 70, tilting the arm 36 up away from the turntable 10 and over the peak onto the surface 68. While returning over the surface 68 the arm 36 tilts back down towards the turntable 10 so that the probe 34 extends over the corresponding cuvette 19 in the circle 16 providing a second operative position for delivery of a liquid to a cuvette 19.

The cam shaft 50 is coupled through the gears 72 and 74 to a drive motor 76 (FIGURE 2). Two pins 78 and 80 are mounted on the gear 72 to engage a roller 82 of a snap action switch 84 to provide a signal when a half revolution of the cam 48 has been completed.

The operation of the automatic sampling apparatus of the figures is controlled by a suitable timer device, such as a motor driven cam timer. A cam motor (FIGURE 4) is connected to a pair of power terminals 92 (adapted to be connected to the 60 cycle line mains) through a switch 94. When the motor 90 is energized, a cam periodically closes a switch 96, momentarily energizing the turntable motor 24. The motor 24 is held energized by the contacts 98 of the snap action switch 30 until the next sample container 18 and cuvette 19 move into the sampling site 32.

Shortly thereafter, the timer device momentarily closes the contacts 100 to energizing the motor 76 to drive the pin 78 away from the roller 82 of the snap action switch 84. The contacts 102 of the snap action switch 84 are closed to keep the motor energized until the pin 80 actuates the switch 84. At this time the probe 34 is inserted into a sample container 18 as illustrated in FIGURE 3. The probe 34 is adapted to be connected to suitable pump means for removing the sample therein. The switch contacts 100 are again momentaril closed and the motor 76 is energized by the switch contacts 102 (snap action switch 84) until the pin 78 engages the roller 82 to actuate the switch 84, At this time the probe 34 is positional over a cuvette 19 in the sampling site 32 as illustrated in FIG- URE 2.

The liquid sample can now be transferred to the cuvette 19 along with other reagents by suitable pump means. The sequence is automatically repeated until all the samples are removed and transferred, at which time apparatus is deenergized by opening the switch 94.

It should be noted that the combined action of the cam 46, the pin 44 and the slide 38, moves the probes 34 into and out of the sample container 18 in a path within a plane substantially normal to the plane of the turntable 10. The shape of the sample container conforms with the path of movement of the probe 34 to provide for free movement therein and also allows the maximum withdrawal of the liquid sample therein.

Referring now to FIGURES 5-8, the sample container 18 is formed with a top portion 104 having three substantially straight sections and a fourth curved section connected to form an enlarged cap with an opening 106 for receiving the probe 34. The sides 108 of the container 18 extend away from the top portion 104 and follow substantially the same shape, slightly reduced in size, and include a slight taper toward each other. The holes in the row 14 have the same general shape as the outer perimeter of the sample container 18 and receive the container so that the curved portion of container extends toward the shaft 12 and the bottom of top portion 104 rests on the turntable 10. The container 18 also includes an elongated bottom portion 110 facing the opening 106 which is substantially smaller than the opening 106. In the present embodiment, the area of the bottom portion 110 is in the order of 15% of the size of the opening 106. The bottom portion is connected to the curved portion of the container sides 108 and an inclined panel 112 extending from an opposite portion of the top portion 104 disposed at an angle 114 in the order of 50 with respect to the plane of the top portion 104. The bottom portion 110, the sides 108, and the inclined panel 112 define a highly tapered cavity for receiving the liquid sample. The bottom edges of the sides 108 lie in a plane substantially parallel to the plane including the top portion 104 and thereby provide a stable surface for setting the container 18 when filling. A void 113 is included merely to save material in the manufacture of the container 18.

When the container 18 is placed in the turntable 10 and subsequently rotated into the sampling site 32, the inclined panel 112 is located in a plane substantially normal to the plane of movement of the probe 34. The inclination of the panel 112 provides suft'icient clearance for the probe 34 to reach the bottom portion 110 of the container 18 as shown in FIGURE 3. The highly tapered cavity of the container 18 allows the probe 34 to remove substantially all the liquid sample therein. By minimizing the area of the bottom portion 110 and correspondingly increasing the sample depth, the amount of sample waste is minimized in an inverse relation to the size of the bottom portion 110.

The size of the opening 106 is sufficiently large to provide a large tolerance for the relative movement or positioning of the turntable 10 and for the movement of the probe 34 into the sample container. The bottom portion 110 has an elongated shape with the larger dimension disposed in or along the direction of movement of the turntable thereby providing a wide tolerance in the positional step by step movement of the turntable 10.

The sample containers 18 may be inexpensively made of plastic by injection molding with a wide manufacturing tolerance range. If the sample container 18 is built with undesirable projected portions or other defects that prevent the seating of the top portion 104 on the turntable 10, the probe 34 cooperates with the panel 112 to reach the bottom portion 110. As previously mentioned, the arm 36 is gravity biased so that the pin 44 rides on the cam 46. If the container 18 is not properly seated, the movement of the probe 34 engages the inclined panel 112 and slides down the panel (due to the movement of the slide 38) until the probe 34 reaches the bottom portion 110 thereby providing for maximum withdrawal of the liquid sample.

I claim:

1. A liquid sample container for automatic sampling apparatus including a carrier formed with a plurality of openings in a plane, each of said openings being adpated to receive a sample container to move said containers in a step by step motion along a predetermined path and means for sequentially moving a probe in an arcuate path along a plane substantially normal to the plane of the carrier into and out of the containers for withdrawing the contents therein during the dwell period of said carrier, said plurality of openings are unsymmetrically formed with reference to said predetermined path, said container comprising:

a top portion formed with an opening therein for receiving said probe;

side portions connected to said top portion and shaped to conform with said openings and adapted to be mounted therein in a preset arrangement with respect to said arcuate path so that said top portion engages said plane of said carrier;

an elongated bottom portion substantially smaller than the size of said opening in said top portion, connected to said side portions, the greater dimension of said bottom portion being positioned substantially parallel to said predetermined path of movement, and is substantially larger than the largest dimension of a cross-section of said probe taken along a plane parallel to said carrier, and

an inclined panel connected to said top, bottom and side portions defining a highly tapered cavity for receiving liquid samples therein, said panel extends upwardly and outwardly from said bottom portion toward said arcuate path providing clearance for the movement of said probe for engagement with said bottom portion and provides for the withdrawal of substantially all of said liquid test sample therein.

2. A liquid test sample container as defined in claim 1 wherein the area of the bottom portion is in the order of 15% of the size of the opening in the top portion.

3. A liquid test sample container as defined in claim 2 wherein the panel is inclined at an angle in the order of fifty degrees with respect to the plane of said top portion.

4. A liquid test sample container as defined in claim 3 wherein said probe is gravity biased for movement into and out of said containers, and said incline plane acts as a guide for directing said probe to said bottom portion when a container is improperly seated in said unsymmetrical opening.

References Cited UNITED STATES PATENTS 2,879,141 3/1959 Skeggs. 3,03 8,340 6/ 1962 Isreeli. 3,190,731 6/1965 Weiskopf. 3,230,776 1/ 1966 Isreeli et al.

S. CLEMENT SWISHER, Primary Examiner.

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