US3511613A - Transporter for sample tubes - Google Patents

Description

May 12, 1970 A. R. JONES TRANSPORTER FOR SAMPLE TUBES 2 Sheets-Sheet 1 Filed Dec. .5, 1967 I N VEN TOR IIIIIII ALAN RICHARDSON JONES RECIRCULATING F PUMP a HEATER May 12, 1970 A. R. JONES 3,511,613

TRANSPORTER FOR SAMPLE TUBES v Filed Dec. 5, 1967 v 2 Sheets-Sheet 2 MOTOR FIG?) (0 m E INVENTOR.

ALAN RICHARDSON JONES United States Patent US. Cl. 23-259 15 Claims ABSTRACT OF THE DISCLOSURE A sample tube transporter which is particularly suited for use in conjunction with automatic chemical analysis equipment. The transporter includes a frame having an endless horizontal channel in which a multiplicity of vertical sleeves are intermittently advanced in single file. Each sleeve is adapted to receive a sample tube and thereby transport the tube through a plurality of stations along the channel where treatment and analytical steps may be performed. The contents of the sample tubes are maintained at constant temperature and after such tubes have been transported through all of the treating and analyzing stations such tubes and their remaining contents are automatically discarded.

BACKGROUND While transport mechanisms for automatic analysis equipment are known, such mechanisms are generally complex in structure and operation and are subject to problems of maladjustment and breakdown. In one such construction, measured amounts of samples are automatically transferred from sample tubes to conditioning tubes or cavities, the latter tubes or cavities requiring emptying and washing following conditioning and analyzing steps. While washing of the tubes may be performed automatically, such a procedure not only increases the complexity of the apparatus but also introduces a possible source of sample contamination.

While the importance of maintaining precise temperature control over samples has been recognized, the difiiculties of maintaining such control in existing equipment are substantial because of the complexity of such equipment and because certain of the operations, such as the automatic washing procedures mentioned above, may tend to interfere with precise temperature adjustments.

SUMMARY An important aspect of the present invention lies in providing a transporter of relatively uncomplicated construction and operation which is highly dependable in performance. and which thereby overcomes major disadvantages of prior constructions. Each sample tube is guided along an endless path by a plastic sleeve which slidably receives the tube. An endless chain of such sleeves are intermittently advanced along said path, the sleeves being in lateral engagement with each other. Driving force exerted against one of the sleeves is thereby transmitted to all of the sleeves in the chain and, hence, to any and all of the sample tubes received in the openings of such sleeves.

The bottom ends of the sample tubes slide upon the smooth surface of a horizontal platform which is submerged in a constant-temperature liquid bath. When the travel of a tube approaches a complete revolution of the circuit, its guiding sleeve passes over a discharge chute and the disposable sample tube and its contents are automatically discharged.

3,511,613 Patented May 12, 1970 THE DRAWINGS FIG. 1 is a perspective view illustrating a transporter in operative condition mounted in the table surface of an automatic analyzer;

FIG. 2 is an exploded perspective view, shown partially diagrammatically, illustrating the components of the transporter;

'FIG. 3 is an enlarged vertical sectional view taken along line 33 of FIG. 1;

FIG. 4 is an enlarged longitudinal sectional view taken along line 44 of FIG. 1.

DESCRIPTION FIG. 1 illustrates the transporter 10 recessed into the top surface 11 of a cabinet or console which also houses other components of an automatic chemical analyzer. FIG. 2 more fully illustrates the major components of the transporter consisting of a frame A, a container B, drive means C and heating means D. Sleeve elements E and sample tubes F are omitted from FIG. 2 for clarity of illustration but such elements are shown fully in FIGS. 1, 3 and 4.

The frame includes a horizontal bottom platform 12, a top plate 13 and an intermediate plate 14. All three elements are securely connected together in spaced parallel relation by vertical posts 15 each consisting of a bolt 15a and a pair of tubular spacers 15b and 15c (FIG. 3). Each of the plates 13 and 14 has an elongated central opening 16 and 17 therein. Within each opening is a horizontally elongated plate member 18 and 19, the two plate members or islands being secured together in spaced parallel relation, and being affixed to platform 12, by posts 20 which are similar in construction to posts 15. Member 18 is disposed in the same horizontal plane as top plate 13, and member 19 in the same plane as intermediate plate 14.

Within the openings 16 and 17 of the superimposed plates 13 and 14, and at one end of the island formed by members 18 and 19, is an upstanding shaft 21 equipped with star wheels 22 and 23 disposed at the same levels as plates 13 and 14, respectively (FIG. 3). Shaft 21 extends downwardly through an opening 24 in the platform and, together with motor 25 which is suit ably mounted beneath the frame, comprises the driving means C for advancing sleeves E and tubes F.

The edges of plates 13 and 14 which define openings 16 and 17, and the lateral edges of members 18 and 19 and of star wheels 22 and 23, form an endless elongated channel or passage 26 of substantially uniform width for slidably receiving the sleeve members E which in turn loosely receive the sample tubes F. Referring to FIGS. 3 and 4, it will be observed that each sleeve member E is generally cylindrical in shape, having end portions 27 of reduced diameter and an enlarged central or shoulder portion 28. The external diameter of end portions 27 is slightly less than the width of channel 26, whereas the shoulder portion 28 is of greater diameter than the channel and has axial vertical dimensions just slightly less than the distance between plates 13 and 14. Thus, the cylindrical sleeves are restrained against vertical movement with respect to the frame but are free to move horizontally along the channel 26. Each of the sleeve members has a vertical bore 29 extending completely therethrough, the bore having a diameter slightly larger than that of the sample tube F loosely received therein.

The sleeve members 28 may be formed of any suitable material. It has been found, however, that particularly effective results are obtained where the sleeves are formed from tetrafluoroethylene resin because of the solvent and chemical resistance of such material and, in particular,

its low co-eflicient of friction. Plate members 13 and 14 are preferably formed of metal, such as stainless steel, and sample tubes F are formed of glass. As will be brought out more fully hereinafter, the cylindrical sleeves 28 are in sliding contact with both the tubes and the plates; therefore, by forming such sleeves from tetrafiuoroethylene resin a self-lubricating assembly is obtained.

FIGS. 1 and 4 reveal that the parallel sleeves E are in side-by-side contact with each other to form an endless chain of such sleeves along horizontal channel 26. While a series of 34 of such sleeves is illustrated in FIG. 1, it will be understood that a greater or smaller number might be provided, depending on the size of the transport unit as a whole and on the type of tests to be performed in the analyzer. The recesses of the star wheels or sprockets 22 and 23 conform to the curvature of sleeves E so that such sleeves may be received in and advanced by the recesses. The driving force transmitted by the star wheels against the leading sleevethat is, the sleeve about to be released from the sprocket recessesis transmitted by such sleeve to the sleeve directly in front of it, that sleeve in turn pushing the one directly before it, and so on. Thus, even though there is no positive connection between the multiple sleeves of the chain, all of the sleeves are constrained by the plates 13, 14, 18, and 19 against movement in any direction except along channel 26 and are advanced along the channel by a pushing force transmitted throuhg the chain and originating with the sleeve or sleeves in engagement with the sprocket assembly.

The entire frame A is disposed in container B with platform 12 submerged in a body of water or other liquid 30 disposed in the container (FIGS. 3 and 4). Specifically, the platform is disposed far enough below the surface of the liquid so that sample tubes F resting upon the plat form will have their lower portions disposed in the liquid bath. Recirculating and heating means D of any conventional construction serves to maintain the bath at constant temperature. As shown in FIG. 2, a drain tube 31 extends upwardly from the bottom of the container to the desired level of the liquid; any liquid overflowing the top of the tube is heated to a preselected temperature and is returned to the container through inlet tube 32. By constantly recirculating the fluid in the container, the temperature of the bath, and of the samples contained within tubes F, may be precisely controlled.

At the opposite end of the elongated container is an upstanding tube 33 which is coaxial with drive shaft 21 and which, as shown in FIG. 3, projects above the level of bath 30. The tube is welded or otherwise suitably sealed to the bottom of the container about an opening 34 in the bottom wall through which shaft 21 extends.

Adjacent to upstanding tube 33 is a second tube 35 which, like tube 33, has its upper end disposed above the level of bath 30. Tube 35 extends upwardly through the bottom Wall of the container and through an opening 36 in platform 12, and constitutes one element of a sample tube discharge chute assembly. Tube 35 is of larger internal diameter than the outside diameter of each sample tube F and is disposed directly in the path of movement of such sample tubes as they advance along channel 26. A ramp 37 also extends along the path of movement of the tubes in advance of discharge tube 35 and, as shown in FIG. 4, slopes upwardly from the surface of platform 12 to which it is secured to the top of discharge tube 35.

In the operation of the transport, a technician first places a sample tube F into a sleeve at the position indicated by an arrow or other indicia 38- affixed to top plate 13 (FIG. 1). The intermittent drive of the unit advances the tube along the channel in a counterclockwise direction as viewed in FIG. 1. As the tube'is so advanced, it passes through different stations where suitable reagents may be added through feed tubes 39, 40, and 41, depending upon the particular test involved and upon the programming of the unit as a whole. Finally, after the tube has nearly completed the circuit, it passes beneath an extraction device 42 which is adapted to withdraw at least a portion of the contents of the tube for automatic chemical analysis. Thereafter, the sample tube rides upwardly upon ramp 37 until it is positioned directly over the discharge chute 35 and drops through the chute into a suitable waste receiver 43. The empty sleeve E then returns to the starting position where the operator may insert a new sample tube and the entire cycle of operation is repeated.

It will be observed that each of the sample tu-bes F rides or slides upon the smooth top surface of platform 12 and is therefore maintained in its vertical position throughout nearly the entire cycle by that platform. The channel-defining plates 13, 14, 18, and 19 serve to guide the sleeves and sample tubes in horizontal directions while the platform and ramp 37 control the vertical positioning of the sample tubes.

While in the foregoing I have disclosed an embodiment of the invention in considerable detail for purposes of illustration, it will be understood by those skilled in the art that many of these details may be varied without departing from the spirit and scope of the invention.

I claim:

1. A transporter for sample tubes in chemical analysis equipment comprising a frame having horizontal members defining an endless horizontal channel of uniform width; a plurality of sleeves each having an opening extending vertical therethrough and having an external dimension slightly less than the width of said channel; said sleeves being constrained by said frame only for movement along said channel and engaging each other in single file to form an endless chain of sleeves along said channel; driving means successively engageable with each sleeve to advance the same along said channel, the driving force exerted by said means against any one of said sleeves being transmitted by mutual engagement of said sleeves to all of the sleeves in said chain; said sleeves each being adapted to loosely and removably receive a sample tube in the vertical opening thereof.

2. The structure of claim 1 in which sample tubes are loosely and removably received in the openings of said sleeves; and platform means provided by said frame beneath said horizontal members for slidably supporting the bottom ends of said sample tubes as the same are advanced along said channel.

3. The structure of claim 1 in which said sleeves are generally cylindrical in shape.

4. The structure of claim 3 in which each of said cylindrical sleeves is provided with an external shoulder of greater width than said channel; said horizontal frame members including spaced horizontal plates disposed above and below the shoulder of each cylindrical sleeve; whereby said cylindrical sleeves are restrained against vertical movement relative to said frame.

5. The structure of claim 1 in which said channel is in the shape of an elongated endless track.

6. The structure of claim 3 in which said driving means includes a star wheel rotatable about a vertical axis and engageable with each of said cylindrical sleeves as they advance along said channel.

7. The structure of claim 1 in which said sleeves are formed of tetrafluoroethylene resin.

8. The structure of claim 2 in which said frame is provided with a sample tube discharge opening at a selected point along the path of travel of said sample tubes for the sequential release from said sleeves of sample tubes advanced along said channel.

9. The structure of claim 8 in which said frame is disposed in an open-topped container supporting a body of liquid having a level substantially :above the surface of said platform means; a tubular discharge chute extending upwardly through said opening in said platform to a point above the level of the liquid body in said container; and ramp means for guiding the lower ends of sample tubes from the level of said platform to the open upper end of said tubular chute as said sample tubes are advanced along said channel.

10. The structure of claim 9 in which means are provided for maintaining said liquid Within said container at a constant pre-selected temperature.

11. A transporter for sample tubes in chemical analysis equipment comprising a frame having members defining an elongated horizontal channel of uniform width; a plurality of vertical cylinders having openings extending axially therethrough and each having an external dimension slightly narrower than said channel; said cylinders engaging each other in single-file relation and being constrained by said frame for horizontal movement along said channel; means for advancing said cylinders along said channel; a platform spaced below said members and providing a smooth horizontal surface for slidably supporting the lower ends of upstanding sample tubes loosely received in said cylinders; and a tube discharge chute through said platform at a selected point along said channel for the sequential release from said cylinders of sample tubes advanced along said channel.

12. The structure of claim 11 in which said frame is disposed in an open-topped container supporting a body of liquid having a level substantially above the surface of said platform; said discharge chute comprising an opening in said platform, a vertical tubular member having its lower end sealed to said platform about the edges of said platform opening and having its open upper end disposed above the level of said liquid, and ramp means for guiding the lower ends of sample tubes from the level of said platform to the open upper end of said tubular member as said tubes are advanced along said channel.

13. The structure of claim 12 in which means are provided for maintaining said liquid within said container at a constant pre-selected temperature.

14. The structure of claim 11 in which each of said cylinders is provided with an external shoulder of greater width than said channel; said frame members comprising vertically-spaced plates disposed above and below the shoulders of each cylinder; whereby said cylinders are restrained against vertical movement relative to said frame.

15. The structure of claim 11 in which said cylinders are formed of tetrafluoroethylene resin.

References Cited UNITED STATES PATENTS 3,202,188 8/1965 Allington 141130 3,410,321 11/1968 Mitchell 141-130 3,432,271 3/1969 Wasilewski 23-259 X 3,441,383 4/1969 Moore et al. 232S9 X MORRIS O. WOLK, Primary Examiner R. E. SERWIN, Assistant Examiner US. Cl. X.Rv

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