AUTOMATIC CHEMISTRY ANALYZER WITH SAMPLE CUP STOPPER PIERCING ASSEMBLY

Abstract: The invention provides an apparatus for piercing the cap of a container. The apparatus includes a blade support arm slidably attached to one or more vertical posts, a blade attached vertically below the blade support arm, and a cap retainer arm slidably attached to the vertical post such that the cap retainer arm is capable of travel along the posts between an upper position wherein the cap contacting surface is located above the elevation of the container cap and a lower position wherein the cap contacting surface is located at the elevation of the container cap. The cap retainer arm has an opening through which the blade can pass. A biasing member biases the cap retainer arm towards its lower position. The cap retainer arm is positioned below the blade but above the blade support arm contact surface. Thus, when the blade support arm slides upwardly, the blade support arm contacts the cap retainer arm and pushes the cap retainer arm upwardly from its lower position to its upper position.

Description: AUTOMATIC CHEMISTRY ANALYZER WITH SAMPLE CUP STOPPER PIERCING ASSEMBLY FIELD OF THE INVENTION This invention generally relates to the field of automated clinical chemical analyzers, and specifically to high throughput automated chemical analyzers having automated sample container loading assemblies. BACKGROUND OF THE INVENTION A number of different automated clinical chemical analyzers are known in the art. Such analyzers range from simple, largely manually operated instruments to highly complex, nearly fully automated instruments. Each analyzer has its own particular performance characteristics related to the number ("menu") of different tests that the analyzer can perform and the number of samples that can be processed in a given period of time ("throughput"). Large scale, highly complex analyzers useful in large hospitals and clinical laboratories have been developed which have both a large menu of tests which the instrument can perform and a high throughput. Such an analyzer is described in U.S. Patent No. 4,965,049 issued to Lillig et al. which is incorporated herein by reference in its entirety. Many such large scale, highly complex analyzers comprise an automated sample loading mechanism designed to mechanically transport sample containers from a convenient loading location to a receiving site within the analyzer where liquid sample are extracted from the sample containers by suitable liquid extraction equipment. Such automated loading mechanisms minimize operator time required to operate such analyzers and therefore increase the operating efficiency of such analyzers. A significant problem with automatic loading mechanisms of the prior art is that such automatic loading equipment are incapable of efficiently opening the sealed caps on the sample containers to allow the liquid extraction equipment to get at the sample within the container. Accordingly, the sealed caps on the sample containers have to be opened manually. This requires an undue amount of operator time and markedly decreases the operating efficiency of the analyzer. Accordingly, there is a need for a sample container cap piercing tool which can be efficiently adapted into the automatic loading mechanism of a large scale, highly complex analyzer so that such automated loading mechanisms are fully automated. SUMMARY OF THE INVENTION The invention satisfies these needs. The invention is a combination for piercing a container cap disposed on the top of a container wherein the top of the container is disposed at a certain location L. The combination comprises: (a) a base; (b) a blade attached to a blade support arm, the blade support arm being attached to the base such that the blade support arm is capable of movement between a first blade support arm position wherein the blade is disposed spaced apart from the location L and a second blade support arm position wherein the blade is disposed immediately below location L; (c) a cap retainer arm having a cap contacting surface capable of contacting and retaining the container cap, the cap retainer arm being attached to the base such that the cap retainer arm is capable of movement between a first cap retainer arm position wherein the cap contacting surface is spaced apart from the location L and a second cap retainer arm position wherein the cap retaining surface is disposed substantially at the location L; and (d) a motor for causing the serial movement of (i) the cap retainer arm from the first cap retainer arm position to the second cap retainer arm position, (ii) the blade support arm from the first blade support arm position to the second blade support arm position, (iii) the blade support arm from the second blade support arm position to the first blade support arm position and (iv) the cap retainer arm from the second cap retainer arm position to the first cap retainer arm position; so that, when a container cap is disposed at the cap retainer location L, the container cap can be serially (i) retained by the cap retainer arm, (ii) pierced by the blade, (iii) released from contact with the blade and (iv) released from contact with the cap retainer arm. In a preferred embodiment, the combination comprises: (a) a blade support arm slidably attached to a substantially vertical post such that the blade support arm is capable of travel along the vertical post between an upper blade support arm position, a middle blade support arm position and a lower blade support arm position, the blade support arm having an upper contact surface and a lower contact surface; (b) a blade attached to the blade support arm and disposed substantially vertically below the blade support arm, the blade being capable of piercing the container cap by downward movement of the blade; (c) a cap retainer arm having a cap contacting surface capable of contacting and retaining the container cap, the cap retainer arm being slidably attached to the vertical post such that the cap retainer arm is capable of travel along the vertical post between the blade support arm upper contact surface and the blade support arm lower contact surface; (d) a biasing member for biasing the cap retainer arm towards the blade support arm lower contact surface; and (e) a motor for sliding the blade support arm up and down along the vertical post between the upper blade support arm position, the middle blade support arm position and the lower blade support arm position; wherein, (i) at the upper blade support arm position, the blade support arm lower contact surface retains the cap retainer arm so that the cap contacting surface is above location L, (ii) at the middle blade support arm position, the cap contacting surface is allowed to contact a container cap disposed at location L but the blade is disposed higher than location L and (iii) at the lower blade support arm position, the cap contacting surface is allowed to contact a container cap disposed at location L and the blade is disposed immediately below location L. In a typical embodiment, the blade support arm and the cap retainer arm are slidably attached to a pair of vertical posts which are fixed to the base and the biasing member comprises a pair of springs. Preferably, the cap contacting surface of the cap retainer arm is recessed to readily accept and retain the cap of the sample container. The invention is advantageously encompassed into an automated diagnostic machine capable of determining at least one parameter of a liquid disposed within one or more capped sample containers disposed within a loading area. Such a machine typically further comprises: (a) a body; (b) a sample station disposed within the body, the sample station being sized and dimensioned to retain a plurality of sample containers; (c) a reagent station disposed within the body, the reagent station being sized and dimensioned to retain a plurality of reagent containers; (d) an analyzing station disposed within the body, the analyzing station comprising: (i) a reaction container and (ii) an analyzer for analyzing liquids disposed within the reaction container; (e) a sample transfer apparatus for transferring liquid sample from the sample station and reagent from the reagent station to the reaction container; and (f) a sample container loading mechanism for transporting sample containers from a sample container loading area to the sample station. In such a machine, it is preferable that suitable switching equipment is provided along the sample transfer apparatus so that the motor of the combination is operated automatically as sample containers are transferred into position within the combination. The invention provides significant improvements over the prior art by providing an apparatus which allows operators of large scale, complex diagnostic analyzers to operate such analyzers in an almost fully automated mode without substantial operator time having to be expended in the preparation of containers containing samples for analysis. DESCRIPTION OF THE DRAWINGS These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings where: Figure 1 is a schematic plan view of an automated analyzing machine having features of the invention; Figure 2 is a front view of an automated analyzing machine having features of the invention with its canopy closed; Figure 3 is another front view of the automated analyzing machine of Figure 2 shown with its canopy open; Figure 4A is a perspective of a sample container rack useful in the invention; Figure 4B is a perspective view of a reaction cuvette useful in the invention; Figure 4C is a cross-sectional side view of the reaction cuvette shown in Figure 4B; Figure 5A is a perspective view of a sample probe arm assemble useful in the invention; Figure 5B is a perspective view of a reagent probe arm assembly; Figure 5C is a perspective view of a cup analyze probe arm assembly; Figure 5D is a perspective view of a cuvette stirring rod assembly; Figure 5E is a perspective view of a cuvette wash station; Figure 6 is a flow diagram showing a reaction cup combination useful in the invention; Figure 7 is a flow diagram showing an ion selective reaction cup assembly useful in the invention; Figure 8 is an exploded perspective view of a sample cap piercing assembly having features of the invention; Figure 9 is an end view of a blade useful in the sample cup piercing assembly shown in Figure 8; Figure 10A is a cross-sectional side view of the sample cup piercing assembly shown in Figure 8, wherein the blade support arm is at the upper blade support arm position; Figure 1 0B is a cross-sectional side view of the sample cup piercing assembly shown in Figure 8, wherein the blade support arm is at the middle blade support arm position; and Figure 10C is a cross-sectional side view of the sample cup piercing assembly shown in Figure 8, wherein the blade support arm is at the lower blade support arm position. DETAILED DESCRIPTION The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well. For a definition of the complete scope of the invention, the reader is directed to the appended claims. Figures 1 - 3 show an automated analyzing machine 10 having features of the invention. The machine 10 comprises a body 12, a sample station 14, a reagent station 16, a random access analyzing station 18, a reaction cup analyzing station 20 and an ion selective electrode analyzing station 22. The body 12 is typically a cabinet providing a housing for the various operative components. The body 12 is typically made from a lightweight metal such as a lightweight sheet steel. The embodiment shown in Figures 2 and 3 includes a hinged primary canopy 24. Figure 2 shows the analyzing machine 10 with the primary canopy 24 closed. Figure 2 shows the machine with the primary canopy 24 open. Figures 2 and 3 also illustrate how a typical analyzing machine 10 of the invention can have an on-load tray cover 26, an off-load tray cover 28 and one or more operator area covers 30 covering the sample station 14, the reagent station 16, the random access analyzing station 18, the reaction cup analyzing station 20 and the ion selective electrode analyzing station 22. The sample station 14 is sized and dimensioned to retain a plurality of sample containers 32. In the embodiment shown in Figures 1 - 3, the sample station 14 is a revolving circular carousel capable of retaining 40 sample containers 32 disposed in 1 0 sample container racks 34. In a typical embodiment, each sample container 32 is a generally upright container having a container cap 36 of thin rubber or like material. A sample container rack 34 containing four sample containers 32 useful in the invention is shown in Figure 4A. The sample station 14 is moveable by a rotating motor (not shown) such that each sample container 32 can be alternatively positioned under and moved away from at least one sample extraction site 38. The reagent station 16 is sized and dimensioned to retain a plurality of reagent containers 40. Each reagent container 40 contains one or more compartments for retaining one or more different reagents useful in the analysis chemistry performed by the analyzing machine 10. Also, it is preferable to predilute the reagent to minimize reagent usage and dilution step delays. A preferred reagent container 40 design has three individual compartments and is described in detail in U.S. Patent Nos. 4,970,053 and 5,075,082, which are both incorporated herein by this reference in their entireties. Preferably, the reagent station 16 is refrigerated, such as to a temperature of about 4°C, to preserve reagent life and minimize evaporation. In the embodiment shown in Figures 1 - 3, the reagent station 16 is a revolving circular carousel. The reagent station 16 is movable by a rotating motor (not shown) such that each reagent container 40 can be alternatively positioned under and moved away from at least one reagent extraction site 42. Preferably, the reagent station 16 also includes a bar code reader (not shown) which reads bar-coded information printed on the reagent containers 40 and/or disposed on the reagent carousel. Such information can be transmitted to a computerized controller to assist in operation of the analyzing machine 10. The random access analyzing station 18 is sized and dimensioned to retain a plurality of reaction cuvettes 44 as illustrated in Figures 4B and 4C. In the embodiment shown in Figures 1 - 3, the random access analyzing station 18 is a revolving circular carousel capable of retaining in excess of 1 00 cuvettes 44. Each cuvette 44 is a small open top reaction container having at least two opposed transparent sides through which a beam of light can be directed. The random access analyzing station 18 further comprises random access analyzing station analyzer 46, such as a nephelometer and/or photometer disposed proximate to a random access analyzing station analyzing site 48 for determining at least one parameter of a sample disposed within the cuvettes 44. The random access analyzing station 18 is movable by a rotating motor (not shown) such that each cuvette 44 can be alternatively positioned under and moved away from at least one cuvette sample deposit site 50, at least one cuvette reagent deposit site 52, at least one cuvette mixing site 54, at least one cuvette washing site 56 and the one random access analyzing station analyzing site 48. The reaction cup analyzing station 20 comprises at least one reaction cup module 58. In the embodiment shown in Figure 1 , the reaction cup analyzing station 20 comprises six reaction cup modules 58. Each reaction cup module 58 can be used to measure high volume analyses such as analyses for sodium, potassium, glucose, creatinine and blood urea nitrogen. Figure 6 illustrates a flow scheme for a typical reaction cup module. Reagent is provided to a reaction cup 332 via an inlet conduit 330 on one side of the reaction cup module 58 (the right side on Figure 6). Reagent is pumped from a source of reagent 380 by the reagent pump 59 through remote controllable reagent valves 384 into the inlet conduit 330. Within that portion of the inlet conduit 330 which is partially disposed within the reaction cup module 58, reagent is heated by a heating element 326 before flowing into the reaction cup 332. Deionized rinse water is provided to the reaction cup 332 from a pressurized source of deionized water 348 through a remote controllable deionized water valve 386 and into the inlet conduit 330 on the side of the reaction cup module 58 opposite the inlet conduit 330 through which reagent flows into the reaction cup 332. In that portion of the inlet conduit 330 which is disposed within the reaction cup module 58, deionized rinse water is heated by a second heating element 326 immediately prior to its flow into the reaction cup 332. The reaction cup 332 is drained via a drain line 388 through a remote controllable master drain valve 390. When the liquid to be drained is of a potentially hazardous sort, the liquid is drained to a suitable hazardous waste container 392 through a remote controllable hazardous waste container valve 394. Where the liquid to be drained is of a non-hazardous sort, the liquid is drained to a suitable non-hazardous waste container 396 through a remote controllable non-hazardous waste container valve 398. Both the hazardous and non-hazardous waste containers 392 and 396 are typically maintained under vacuum to facilitate rapid and complete draining of liquid from the reaction cup 332. Because a separate deionized rinse water source 348 is provided to the reaction cup 332, such deionized rinse water is conveniently and inexpensively used in the rinsing step. Moreover, because water is used in the rinse steps, much of the liquid drained from the reaction cup during the rinsing step can be disposed in a non-hazardous waste disposal area. Note further that because two separate heating elements 326 are used, time lags required for heating are much reduced. This is especially true in analysis operations requiring multiple rinse cycles. The use of the rinse water system also provides another substantial benefit over the prior art. The analyzing machine 10 using the cup analysis module 58 of the invention can be programmed to periodically and automatically recalibrate a nephelometer used as an analyzer 334, by briefly filling the reaction 332 cup with pure rinse water and calibrating the nephelometer to a predetermined set point. This eliminates having to periodically shut down the machine 10 and manually calibrating each of the nephelometers used in the various reaction cup modules 58. A particularly useful reaction cup module 58 is disclosed in detail U.S. Patent Application Serial No. , entitled , filed contemporaneously herewith, and which is incorporated herein by reference in its entirety. The ion selective electrode analyzing station 22 comprises a sample injection cup 60 disposed in fluid tight communication with a flow cell analyzer 62 capable of measuring at least one electrolyte in a liquid sample. The ion selective electrode analyzing station 22 can be used to simultaneously analyze for sample electrolytes (and sample components which can be analyzed as electrolytes), such as sodium, potassium, calcium, chlorine and carbon dioxide. Figure 7 illustrates a simplified flow scheme for a typical ion selective analyzing station 22. The sample injection cup 60 is disposed in fluid tight communication with an ion selective electrode analyzing station pump 64 capable of pumping at least one ion selective electrode analyzing reagent from a source of such reagent (not shown) through the sample injection cup 60, through a valve V1 , through the flow cell analyzer 62 and then to a suitable waste disposal site. Sample is pressured into the sample injection cup 60 via a cup analysis probe 138 (described below). In the sample injection cup, the sample is mixed with reagent as the reagent is pumped by pump 64 through the sample injection cup 60 and is carried therewith through valve V1 and into the flow cell analyzer. A C0 2 acid reagent pump 63 capable of pumping C0 2 acid reagent directly into the flow cell analyzer 62 is disposed in fluid tight communication with a source of C0 2 acid reagent (not shown). Also, an ion selective analyzing station reference solution pump 65 is disposed in fluid tight communication with a source of reference solution (not shown). The ion selective electrode analyzing station reference solution pump 65 is capable of pumping reference solution through valve V2 directly into the flow cell analyzer 62. In a preferred embodiment, the ion selective electrode analyzing station pump 64, the C0 2 acid reagent pump 63 and the ion selective electrode analyzing station reference solution pump 65 are driven by a single motor. A particularly useful ion selective analyzing station 22 is disclosed in detail in U.S. Patent Application Serial No. , entitled , filed contemporaneously herewith, and which is incorporated herein by reference in its entirety. The analyzing machine 10 further comprises a motorized sample probe arm assembly 90 such as shown in Figure 5A. The sample probe arm assembly 90 includes a sample probe arm 92 and a hollow sample probe 94. The sample probe 94 has an internal chamber 96, an open lower end 98 and an open upper end 100. The sample probe 94 is disposed generally vertically in the sample probe arm 92 and is movable by a sample probe motor 102 between a lower sample probe position and an upper sample probe position. The sample probe 94 can be equipped with a sample probe tip cleaning assembly 104 such as is described in U.S. Patent No. 5,408,891 , the entirety of which is incorporated herein by this reference. Such cleaning assembly 104 includes a cleaning assembly chamber 106 connected in fluid tight communication with a source of cleaning liquid 108 and a disposal site 1 10. The sample probe arm 92 is movable by a sample probe arm motor (not shown) between a first sample probe arm position wherein the sample probe is immediately above the sample extraction site 38 and a second sample probe arm position wherein the sample probe is immediately above the cuvette sample deposit site 50. The sample probe 94 is connected to a sample probe pressure altering mechanism capable of alternatively applying a positive pressure and a negative pressure to the internal chamber 96 of the sample probe 94. Such pressure altering mechanism can be any of the various pressure altering mechanisms known in the art. Typically, such pressure altering mechanisms are provided by a syringe pump 1 12. The sample probe arm assembly 90 is used to extract a predetermined quantity of sample from sample container 32 disposed within the sample station 14 at the sample extraction site 38 and transport that quantity of sample to a cuvette 44 disposed within the random access analyzing station 18 at the cuvette sample deposit site 50. The analyzing machine 10 further comprises a motorized reagent probe arm assembly 1 14 such as shown in Figure 5B. The reagent probe arm assembly 1 14 includes a reagent probe arm 1 16 and a hollow reagent probe 1 18. The reagent probe 1 18 has an internal chamber 120, an open lower end 122 and an open upper end 124. The reagent probe 1 18 is disposed generally vertically in the reagent probe arm 1 16 and is movable by a reagent probe motor 126 between a lower reagent probe position and an upper reagent probe position. The reagent probe arm 1 16 is movable by a reagent probe arm motor (not shown) between a first reagent probe arm position wherein the reagent probe 1 18 is immediately above the reagent extraction site 42 and a second reagent probe arm position wherein the reagent probe is immediately above the cuvette reagent deposit site 52. The reagent probe 1 18 is connected to a reagent probe pressure altering mechanism capable of alternatively applying a positive pressure and a negative pressure to the internal chamber 120 of the reagent probe 1 18. Such pressure altering mechanism can be any of the various pressure altering mechanisms known in the art. Typically, such pressure altering mechanisms are provided by a syringe pump 128. The reagent probe arm 1 16 is used to extract a predetermined quantity of reagent from a reagent container 40 disposed within the reagent station 16 at the reagent extraction site 42 and transport that quantity of reagent to a cuvette 44 disposed within the random access analyzing station 18 at the cuvette reagent deposit site 52. Both the sample probe arm 92 and the reagent probe arm 1 16 can include multiple independently movable probes. In the embodiment illustrated in the drawings, both the sample probe arm 92 and the reagent probe arm 1 16 comprise a pair of probes each independently movable about a primary axis of rotation 130. Both probe arms are also rotatable as a whole about a secondary axis of rotation 132. The analyzing machine 10 further comprises a cup analysis probe arm assembly 134 such as shown in Figure 5C. The cup analysis probe arm assembly 134 includes a cup analysis probe arm 136 and a hollow cup analysis probe 138. The cup analysis probe 138 has an internal chamber 140, a lower end 142 and an open upper end 144. The cup analysis probe 138 is disposed generally vertically in the cup analysis probe arm 136 and is movable by a cup analysis probe motor (not shown) between a lower cup analysis probe position and an upper analysis probe position. The cup analysis probe 138 can be equipped with a cup analysis probe tip cleaning assembly 146 such as is known in the prior art. Such cleaning assembly includes a cleaning assembly chamber 148 connected in fluid tight communication with a source of cleaning liquid 150 and a disposal site 152. The cup analysis probe arm 136 is movable by a cup analysis probe arm motor (not shown) between a first cup analysis probe arm position wherein the cup analysis probe is immediately above a sample container 32 in the sample station 14, a second cup analysis probe arm position wherein the cup analysis probe 136 is immediately above one of the reaction cup modules 58 and a third cup analysis probe arm position wherein the cup analysis probe 136 is immediately above the sample injection cup 60. The cup analysis probe 136 is connected to a cup analysis probe pressure altering mechanism capable of alternatively applying a positive pressure and a negative pressure to the internal chamber 140 of the cup analysis probe 136. Such pressure altering mechanism can be any of the various pressure latering mechanisms known in the art. Typically, such pressure altering mechanisms are provided by a syringe pump 154. The cup analysis probe arm assembly 134 is used to extract a predetermined quantity of sample from a sample container 32 disposed within the sample station 14 and transport that quantity to each of the reaction cup modules 58 and to the sample injection cup 60. The analyzing machine 10 further comprises a cuvette stirring rod assembly 156 such as shown in Figure 5D. The cuvette stirring rod arm assembly 156 includes an elongate rotatable cuvette stirring rod 158 having a lower end 160 and an upper end 162. The lower end 160 of the cuvette stirring rod includes a cuvette stirring rod paddle 164 attached thereto. The cuvette stirring rod is generally disposed vertically and is movable between a lower cuvette stirring rod position and an upper stirring rod position. The cuvette stirring rod arm assembly 156 is positionable above the cuvette mixing site 54. As illustrated by the embodiments shown in the drawings, the motorized cuvette stirring rod assembly 156 can be an independent and separate assembly or it can be integrated with the sample probe arm 92 and/or the reagent probe arm 1 16. The analyzing machine 10 further comprises a cuvette wash station 166 as shown in Figure 5E. The cuvette wash station probe 168 is used to extract liquid reaction mixtures from the cuvettes 44, dispose such mixtures to a suitable disposal site and then rinse and clean the cuvette 44 so that it can be used to analyze another quantity of sample. The wash station 166 comprises one or more motorized cuvette wash station probes 168. Each wash station probe 168 has an internal chamber 170, an open lower end 1 72 and an open upper end 174. The wash station probe 168 is disposed generally vertically above the cuvette washing site 56 in the random access analyzing station 18 and is movable by a wash station probe motor (not shown) between a lower wash station probe position and an upper wash station probe position. In the embodiment shown in the drawings, the wash station probes 168 operated in pairs, one of each pair of wash station probes 168 being connected to a source of pressurized rinse solution and the other wash station probe 168 of each pair being connected to a disposal system adapted to vacuum out the contents of a cuvette and transfer such contents to a suitable disposal site. Alternatively, each individual wash station probe 168 can be connected to a wash station probe pressure altering mechanism capable of alternatively applying a positive pressure and a negative pressure to the internal chamber 170 of the wash station probe 168. The wash station probe pressure altering mechanism includes a mechanism for providing pressurized washing liquid from a source of washing liquid to the wash station probe 168 for washing a cuvette disposed at the cuvette washing site 56 and a mechanism for providing a negative pressure to the interior chamber 170 of the wash station probe 168 for removing waste liquids from a cuvette disposed at the cuvette washing site 56 and for transferring such waste liquids to a disposal site. Such a mechanism for providing negative pressure to the interior chamber 1 70 typically comprises a source of vacuum. Each of the pressure altering mechanism usable in the analyzing machine can further comprise an obstruction detector 176 comprising a pressure transducer operatively installed within the operative pressure transmitting conduits to alert the operator and/or shut down the machine should an obstructive pressure drop be detected within the pressure altering mechanism. Such an obstruction detector 176 is described in detail in U.S. Patent Application Serial No. , entitled , filed contemporaneously herewith, and which is incorporated herein in its entirety. Typically, the automated analyzing machine 10 further comprises a controller 178 for controlling each of the various motors in a way which provides for the smooth, efficient and rapid operation of the machine 10. The control is typically also used to retain and report analysis data. Preferably, the controller 178 comprises a digital computer which can be preprogrammed with a large variety of operating instructions depending upon the samples being analyzed, the analyses to be run and the reagents at hand. Most preferably, the digital computer receives bar coded information regarding each of the samples to be analyzed, and the reagents in the reagent station 16 and uses that information to most efficiently conduct the analyses. Also, it is preferable that the controller 178 keep track of the amounts of reagents used so as to alert the operator whenever reagent in any particular reagent container 40 begins to run low. Also, it is preferable that the controller 178 include a "stat" mode, which gives the operator the ability to require the machine 10 to analyze particularly important samples in the reaction cup and ion selective electrode analyzing stations ahead of all other samples. In the embodiment shown in the drawings, the analyzing machine 10 further comprises a sample container loading and preparation assembly 68. The loading and preparation assembly 68 comprises a loading mechanism 70 for loading one or more sample containers from a loading area 72 to the sample station 14 along a loading mechanism path 74. The loading mechanism 70 comprises an on-load tray 76 and an off-load tray 78. In the embodiment shown in Figure 1 , the on-load tray 76 and the off-load tray 78 are sized and dimensioned to retain a plurality of sample container racks 34. The on-load tray 76 has a motorized loading arm 80 for pushing a plurality of sample container racks 34 towards the loading mechanism path 74. The off-load tray 78 has a motorized unloading arm (not shown) for pushing the sample container racks 34 away from the loading mechanism path 74. The loading mechanism path 74 has a motorized loading path arm 82 which moves a single sample container rack 34 along the loading mechanism path 74 on to and off from the sample station 14. A bar code reader 84 is typically disposed along the loading mechanism path 74. The bar code reader 84 is capable of reading bar coded information disposed on each individual sample container 32 as the sample container 32 moves along the loading mechanism path 74. In the embodiment shown in Figure 1 , the sample container loading and preparation assembly 68 further comprises a sample container cap piercing mechanism 86 capable of piercing the sample container caps 36 so as to leave the caps 36 open for access by the sample probe 94. As illustrated in Figures 2 and 3, the sample container cap piercing mechanism 86 can be disposed under a sample cap piercing mechanism cover 88. Figures 8-1 0 illustrate a preferred embodiment of the sample container cap piercing mechanism 86 in detail. The sample cap piercing mechanism 86 comprises a base 400 having a fixed pair of vertical posts 402. Slidably attached to the two vertical posts 402 is a blade support arm 404. The blade support arm 404 has a lower blade support arm surface 406 and an upper blade support arm surface 408. Operatively disposed within the center of the blade support arm 404 is a drive element 410, such as a worm gear, for driving the blade support arm 404 up and down along the vertical posts 402. Fixed within the blade support arm 404 is at least one blade 412. The blade 412 typically has a base 413 and a plurality of piercing sections 414. A preferred blade 412 has three or more piercing sections 414 disposed in vertical planes which intersect along a single axis 416, each such plane being spaced apart from adjoining planes by equal angles. Figure 1 0 illustrates a preferred blade 412 having four piercing sections 414 spaced apart from adjoining piercing sections 414 by 90°. Preferably, each piercing sections 414 has the shape of a right triangle, wherein the point 418 is disposed further from the single axis 416 than any other portion of the piercing section 414. Also slidably disposed along the vertical posts is a cap retainer arm 420. The cap retainer arm 420 has an upper cap retainer arm surface 422 and a lower retainer arm surface 424. The lower retainer arm surface 424 defines a cap retainer surface 426, which is preferably recessed to accept and retain the cap 36 on a sample container 32. The cap retainer arm 420 has openings 428 which are aligned with the blade 412 disposed within the blade support arm 404. Each opening 428 is large enough to allow the blade 412 to pass through the cap retainer arm 420. As illustrated in Figures 10A, 10B and 10C, the blade support arm 404 is capable of traveling between an upper blade support position (illustrated in Figure 10A), a middle support arm position (illustrated in Figure 10B) and a lower blade support position (illustrated in Figure 10C), so as to pierce the cap 36 of a sample container 32 when the cap 36 is disposed at a location L which is at an elevation E. The blade support arm 404 has a lower contact surface 430 for contacting a lower portion of the cap retainer arm 420 and an upper contact surface 432 for contacting an upper portion of the cap retainer arm 420. The cap retainer arm 420 is slidably attached to the vertical posts 402, such that the cap retainer arm 420 is capable of traveling along the vertical posts 402 between the blade support arm upper contact surface 432 and the blade support arm lower contact surface 430. At least one biasing member 434 is used to bias the cap retainer arm 420 towards the blade support arm lower contact surface 430. A motor 436 is used to operate the drive element 410 to slide the blade support arm 404 up and down along the vertical posts 402 between the upper blade support arm position, the middle blade support arm position and the lower blade support arm position. As illustrated in Figure 10A, when the blade support arm 404 is in the upper blade support arm position, the blade support arm lower contact surface 430 engages the cap retainer arm 420 and retains the cap retainer arm 420 at an elevation spaced apart from the location L and above elevation E. Thus, when the blade support arm 404 is in the upper blade support arm position, sample containers 32 can be moved along the loading mechanism path 74 without being obstructed by the cap retainer arm 404. As illustrated in Figure 10B, when the blade support arm 404 is lowered to the middle blade support arm position, the cap contacting surface 426 on the underside of the cap retainer arm 420 travels downwardly to the location L. At this location, the cap contacting surface 426 is capable of contacting, engaging and retaining the cap 36 on the top of a sample container 32 disposed along the loading mechanism path 74. Because of the downward pressure provided by the biasing member 434, the cap retainer arm 420 firmly retains the sample container 32 in place during the remainder of the cycle wherein the sample container cap 36 is pierced by the blade 412. Preferably, the cap contacting surface 426 is recessed to facilitate the engaging and retaining of the sample container cap 36. At the moment when the cap contacting surface 426 contacts the sample container cap 36, when the blade support arm is at the middle blade support arm 404 position, the blade 412 is disposed apart from the location L, above elevation E, and, therefore, does not (yet) penetrate the sample container cap 36. However, as the blade support arm 404 continues downwardly from the middle blade support arm position to the lower blade support arm position, the blade 412 travels through the opening 428 in the cap retainer arm 420 to an elevation below E immediately below the location L, thereby piercing the sample container cap 36 with the piercing sections 44 of the blade 412. Typically, the downward travel of the blade support arm 404 is terminated when the blade support arm upper contact surface 432 contacts the cap retainer arm 420. After the sample container cap 36 has been pierced, the motor 436 causes the blade support arm 404 to slide upwardly along the posts 402 to the upper blade support arm position. This action causes the lower contact surface 430 of the blade support arm 404 to push the cap retainer arm 420 upwardly against the biasing pressure of the biasing member 434 to an elevation above elevation E. The sample container 32 - now having a pierced sample container cap 36 - is thereby freed up so that it can be further moved along the loading mechanism path 74 to the sample station 14. In operation, the operator of the automated analyzing machine of the invention 10 places samples to be analyzed in individual sample containers 32 and places each sample container 32 in one or more sample container racks 34. The sample container racks 34 are placed in the on-load tray 76. The motorized loading arm 80 pushes sample container racks 34 in the on-load tray 76 towards the loading mechanism path 74. As each sample container rack 34 enters the loading mechanism path 74, the motorized loading path arm 82 pushes the sample container rack 34 along the loading mechanism path 74 towards the sample station 14. As the sample containers 32 pass by the bar code reader 84, bar- coded information appended to each sample container 32 is read by the bar code reader 84 and is transmitted to the controller 178. Such bar code coded information typically includes the identity of the sample and the analyses which are to be run using individual portions of the sample. As the sample container rack 34 is pushed further along the loading mechanism path 74, it passes under the cap piercing mechanism 86 to the location L. The cap piercing mechanism 86 thereat pierces the caps 36 on each of the sample containers 32. The sample container rack 34 then is pushed further along the leading mechanism path 74 to the sample station 14 wherein a clamping mechanism within the sample station 14 holds the sample container rack 34 firmly upright. The sample station 14 is rotated under the control of the controller 178. When an individual sample container 32 is placed at a sample extraction site 38, a small quantity of the sample is extracted from the sample container 32 by the sample probe 94. This is accomplished by positioning the sample probe 94 above the sample extraction site 38, lowering the sample probe 94 to the lower sample probe position wherein the open-ended lower end 98 of the sample probe 94 is placed below the surface of the sample within the sample container 32. A small quantity of the sample is then extracted into the sample probe internal chamber 96 by drawing a vacuum on the sample probe internal chamber 96 using the sample probe pressure altering mechanism. The sample probe 94 is then raised to the upper sample probe position and the sample probe arm 92 moves the sample probe 94 to a position where it is directly above the cuvette sample deposit site 50. At the cuvette sample deposit site 50, the sample probe 94 is again lowered to the lower sample probe position and the quantity of sample within the sample probe 94 is deposited into a cuvette 44 positioned at the cuvette sample deposit site 50. This is done by creating a slight elevated pressure within the sample probe internal chamber 96 using the sample probe pressure altering mechanism. The lower end of the sample probe 94 is then retracted into the sample probe tip cleaning assembly 104 where it is rinsed using cleaning liquid from the source of cleaning liquid 108. After cleaning, the cleaning liquid is flushed to a suitable disposal site 1 10. The sample probe 94 is then ready to extract another quantity of sample from another sample container 32. Contemporaneously with the above-described action of the sample probe 94, the reagent probe 1 18 is used in similar fashion to extract a quantity of an appropriate pre-mixed reagent from the reagent station 16 and depositing that quantity of reagent into the cuvette 44. Usually the reagent is added to the cuvette immediately prior to the deposit of the sample within the cuvette 44. After sample and reagent are both added to the cuvette 44, the cuvette 44 is rotated to the cuvette mixing site 54. At the cuvette mixing site 54, the cuvette stirring rod 158 is lowered to the lower cuvette stirring rod position and the stirring rod paddle 164 is rotated so as to agitate and thoroughly mix the sample and reagent within the cuvette 44. In typical random access analyzing operations wherein analyses are carried out at an elevated temperature, the mixture of sample and reagent within the cuvette 44 is then allowed to stand within the random access analyzing station 18 while the mixture is brought up to temperature, such as by blowing heated air through the random access analyzing station 18. When the mixture within the cuvette 44 has reached proper temperature, the contents of the cuvette 44 are analyzed using the random access analyzing station analyzer 46. In a preferred operation, the cuvette 44 is placed at the random access analyzing station analyzing site 46 a plurality of times and is thereby analyzed a plurality of times so that the reportable results are derived from an average of the plurality of analyses. The reportable results are thereby extremely reliable. After analyses are completed regarding the mixture within the cuvette 44, the cuvette 44 is moved to the cuvette washing site 56 at the cuvette wash station 166. At the cuvette wash station 166, a wash station probe 168 is moved from its upper probe position to the lower probe position and the reaction mixture is extracted using the wash station pressure altering mechanism. Depending upon the kind of mixture which had been analyzed within the cuvette 44, the cuvette 44 is then rinsed once or several times using pressurized washing liquid. After the rinse liquid is removed from the cuvette 44 and sent to suitable disposal, the cuvette 44 is ready to accept another sample for analysis. Contemporaneously with the operation of the random access analyzing station 18, high volume analyses are performed in the reaction cup analyzing station 20 and in the ion selective electrode analyzing station 22. First, a predetermined quantity of an appropriate reagent is pumped into each reaction cup 332 and into the injection sample cup 60 using the reagent pump 59. The magnetic stirrer is engaged. Then, the cup analysis probe arm assembly 134 positions the cup analysis probe 136 above a sample container 32 within the sample station 14, the cup analysis probe 136 is lowered to the lower probe position and a relatively large quantity of sample is extracted into the internal chamber 140 within the cup analysis probe 138 using the cup analysis probe pressure altering mechanism. The cup analysis probe 138 is then raised to the upper probe position and the cup analysis probe arm 136 moves the cup analysis probe 138 to a position directly above one of the reaction cup modules 58. The cup analysis probe 138 is lowered to the lower cup position and a portion of the sample within the cup analysis probe 138 is deposited within the reaction cup 332. The cup analysis probe 138 is then again raised to the upper probe position and the cup analysis probe arm 136 moves the cup analysis probe 138 to immediately above each of the other reaction cup modules 58 and deposits a portion of the sample within each such reaction cups 332. When all of the reaction cups 332 are filled, the cup analysis probe arm 136 moves the cup analysis probe 138 to directly above the sample injection cup 60. The cup analysis probe 138 is again lowered to the lower probe position and the remainder of the sample is deposited within the injection sample cup 60. After the mixture of reagent and sample is thoroughly mixed by the magnetic stirrer, the mixture is analyzed using the reaction cup analyzing station analyzer 334 in each cup module, and the results of the analyses are reported to the controller 178. The reaction cups 332 are then rinsed and ready for another sample. Contemporaneously, in the ion specific electrode analysis station, the quantity of sample within the injection sample cup 60 is thoroughly flow mixed with the reagent. After the sample and reagent are properly mixed, the mixture is passed through the flow cell 62 where individual electrodes within the flow cell 62 each perform a single analysis on the mixture. The results of the analysis are reported to the controller 1 78. The mixture is then drained to a suitable disposal site 66 and the system is rinsed in preparation for the analysis of another sample. After the sample within each of the sample containers 32 in a sample container rack 34 are analyzed, the sample container rack 34 is removed from the sample station 14 using the motorized loading path arm 82. The sample container rack 34 is retracted along the loading mechanism path 74 to the off- load tray 78. Once in the off-load tray 78, the motorized unloading arm pushes the sample container rack 34 towards the end of the off-load tray 78 where it is removed by the operator. The invention provides significant improvements over the prior art by reducing throughput times, maintenance costs and operating expense, while increasing accuracy and reliability. Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.

Claims: What is Claimed is: 1 . A combination for piercing a container cap disposed on the top of a container at a location L, the combination comprising: (a) a base; (b) a blade attached to a blade support arm, the blade support arm being attached to the base such that the blade support arm is capable of movement between a first blade support arm position wherein the blade is disposed spaced apart from the location L and a second blade support arm position wherein the blade is disposed immediately below location L; (c) a cap retainer arm having a cap contacting surface capable of contacting and retaining the container cap, the cap retainer arm being attached to the base such that the cap retainer arm is capable of movement between a first cap retainer arm position wherein the cap contacting surface is spaced apart from the location L and a second cap retainer arm position wherein the cap retaining surface is disposed substantially at the location L; and (d) a motor for causing the serial movement of (i) the cap retainer arm from the first cap retainer arm position to the second cap retainer arm position, (ii) the blade support arm from the first blade support arm position to the second blade support arm position, (iii) the blade support arm from the second blade support arm position to the first blade support arm position and (iv) the cap retainer arm from the second cap retainer arm position to the first cap retainer arm position; so that, when a container cap is disposed at the cap retainer location L, the container cap can be serially (i) retained by the cap retainer arm, (ii) pierced by the blade, (iii) released from contact with the blade and (iv) released from contact with the cap retainer arm. 2. A combination for piercing a container cap disposed on the top of a container at an elevation E, the combination comprising: (a) a blade support arm slidably attached to a substantially vertical post such that the blade support arm is capable of travel along the vertical post between an upper blade support arm position, a middle blade support arm position and a lower blade support arm position, the blade support arm having an upper contact surface and a lower contact surface; (b) a blade attached to the blade support arm and disposed substantially vertically below the blade support arm, the blade being capable of piercing the container cap by downward movement of the blade; (c) a cap retainer arm having a cap contacting surface capable of contacting and retaining the container cap, the cap retainer arm being slidably attached to the vertical post such that the cap retainer arm is capable of travel along the vertical post between the blade support arm upper contact surface and the blade support arm lower contact surface; (d) a biasing member for biasing the cap retainer arm towards the blade support arm lower contact surface; and (e) a motor for sliding the blade support arm up and down along the vertical post between the upper blade support arm position, the middle blade support arm position and the lower blade support arm position; wherein, (i) at the upper blade support arm position, the blade support arm lower contact surface retains the cap retainer arm so that the cap contacting surface is higher than E, (ii) at the middle blade support arm position, the cap contacting surface is allowed to contact a container cap disposed at E but the blade is disposed higher than E and (iii) at the lower blade support arm position, the cap contacting surface is allowed to contact a container cap disposed at E and the blade is disposed below E. 3. The combination of claim 2 wherein the blade support arm and the cap retainer arm are slidably attached to a pair of substantially vertical posts disposed in parallel. 4. The combination of claim 2 wherein the biasing member comprises at least one spring. 5. The combination of claim 2 wherein the cap contacting surface of the cap retainer arm is recessed. 6. The combination of claim 2 wherein the blade comprises three or more piercing sections, each piercing section being disposed in a vertical plane and all of the vertical planes being disposed so that they intersect along a single vertical axis with each plane being spaced apart from adjoining planes by equal angles. 7. The combination of claim 6 wherein each piercing section comprises a point which has the shape of a right triangle and wherein the point of each piercing section is disposed further from the single vertical axis than any other portion of the piercing section. 8. The combination of claim 6 wherein the blade comprises four piercing sections, each spaced apart from adjoining piercing sections by about 90 degrees. 9. A device for determining at least one parameter of a the liquid in one or more a capped sample containers disposed in a loading area, the device comprising: (a) a body; (b) a sample station disposed within the body, the sample station being sized and dimensioned to retain a plurality of sample containers; (c) a reagent station disposed within the body, the reagent station being sized and dimensioned to retain a plurality of reagent containers; (d) an analyzing station disposed within the body, the analyzing station comprising: (1 ) a reaction container and (2) an analyzer for analyzing liquids disposed within the reaction container; (e) a sample transfer mechanism for transferring liquid sample from the sample station and reagent from the reagent station to the reaction container; and (f) a sample container loading and preparation assembly comprising (1 ) a loading mechanism for moving one or more vertically disposed capped sample containers from the loading area to the sample station along a loading mechanism path, wherein the location of the caps of the sample containers is at L, and (2) a combination for piercing the cap of the sample containers disposed along the loading mechanism path, such combination comprising: (i) a base; a blade attached to a blade support arm, the blade support arm being attached to the base such that the blade support arm is capable of movement between a first blade support arm position wherein the blade is disposed spaced apart from the location L and a second blade support arm position wherein the blade is disposed immediately below location L; (ii) a cap retainer arm having a cap contacting surface capable of contacting and retaining the container cap, the cap retainer arm being attached to the base such that the cap retainer arm is capable of movement between a first cap retainer arm position wherein the cap contacting surface is spaced apart from the location L and a second cap retainer arm position wherein the cap retaining surface is disposed substantially at the location L; and (iii) a motor for causing the serial movement of (I) the cap retainer arm from the first cap retainer arm position to the second cap retainer arm position, (II) the blade support arm from the first blade support arm position to the second blade support arm position, (III) the blade support arm from the second blade support arm position to the first blade support arm position and (IV) the cap retainer arm from the second cap retainer arm position to the first cap retainer arm position; so that, when a container cap is disposed at the cap retainer location L, the container cap can be serially ( 1 ) retained by the cap retainer arm, (2) pierced by the blade, (3) released from contact with the blade and (4) released from contact with the cap retainer arm. 1 0. The combination of claim 9 wherein the blade support arm and the cap retainer arm are slidably attached to a pair of substantially vertical posts disposed in parallel. 1 1 . The combination of claim 9 wherein the blade comprises three or more piercing sections, each piercing section being disposed in a vertical plane and all of the vertical planes being disposed so that they intersect along a single vertical axis with each plane being spaced apart from adjoining planes by equal angles. 1 2. The combination of claim 9 wherein each piercing section comprises a point which has the shape of a right triangle and wherein the point of each piercing section is disposed further from the single vertical axis than any other portion of the piercing section. 1 3. A device for determining at least one parameter of a the liquid in one or more capped sample containers disposed in a loading area, the device comprising: (a) a body; (b) a motorized sample station disposed within the body, the sample station being sized and dimensioned to retain a plurality of sample containers and having a sample extraction site, the sample station being movable within the body such that, when the sample station retains a plurality of sample containers, individual sample containers can alternatively be moved to and away from the sample extraction site; (c) a motorized reagent station disposed within the body, the reagent station being sized and dimensioned to retain a plurality of reagent containers and having a reagent extraction site, the reagent station being movable within the body such that, when the reagent station retains a plurality of reagent containers, individual reagent containers can alternatively be moved to and away from the reagent extraction site; (d) a motorized random access analyzing station disposed within the body, the random access analyzing station being sized and dimensioned to retain a plurality of cuvettes and having a cuvette sample deposit site, a cuvette reagent deposit site, a cuvette mixing site, a cuvette washing site, a random access analyzing station analyzing site and an analyzer disposed proximate to the random access analyzing station analyzing site for determining at least one parameter of a sample disposed within the cuvettes, the random access analyzing station being movable within the body such that, when the random access analyzing station retains a plurality of cuvettes, individual cuvettes can alternatively be moved to and away from (1 ) the cuvette mixing site, (2) the cuvette washing site and (3) the random access analyzing station analyzing site; (e) a reaction cup analyzing station disposed within the body, the reaction cup analyzing station comprising: ( 1 ) a reaction cup, (2) an analyzer for analyzing liquids disposed within the reaction cup and (3) a reaction cup analyzing station pump mechanism for pumping reaction cup analyzing station reagent from a source of reaction cup analyzing station reagent to the reaction cup and for pumping the contents of the reaction cup to a suitable disposal site; (f) an ion selective electrode analyzing station disposed within the body, the ion selective analyzing station comprising: ( 1 ) a sample injection cup in fluid tight communication with a flow cell analyzer for measuring at least one electrolyte in a liquid sample and (2) an ion selective electrode analyzing station pump mechanism for pumping ion selective electrode analyzing station reagent from a source of ion selective electrode analyzing station reagent to the sample injection cup and for pumping the contents of the sample reaction cup through the flow cell analyzer and then to a suitable disposal site; (g) a motorized sample probe arm assembly attached to the body, the sample probe arm assembly including ( 1 ) a sample probe arm and (2) a hollow sample probe having an internal chamber, an open lower end and an open upper end, the sample probe being disposed generally vertically, the sample probe being vertically movable between a lower sample probe position and an upper sample probe position, the sample probe arm being movable between a first sample probe arm position wherein the sample probe is immediately above the sample extraction site and a second sample probe arm position wherein the sample probe is immediately above the cuvette sample deposit site; (h) a sample probe pressure altering mechanism for alternatively applying a positive pressure and a negative pressure to the interior chamber of the sample probe; (i) a motorized reagent probe arm assembly attached to the body, the reagent probe arm assembly including ( 1 ) a reagent probe arm and (2) a hollow reagent probe having an internal chamber, an open lower end and an open upper end, the reagent probe being disposed generally vertically, the reagent probe being vertically movable between a lower reagent probe position and an upper reagent probe position, the reagent probe arm being movable between a first reagent probe arm position wherein the reagent probe is immediately above the reagent extraction site and a second reagent probe arm position wherein the reagent probe is immediately above the cuvette reagent deposit site; (j) a reagent probe pressure altering mechanism for alternatively applying a positive pressure and a negative pressure to the interior chamber of the reagent probe; (k) a motorized cuvette stirring rod arm assembly attached to the body, the cuvette stirring rod arm assembly including an elongate rotatable cuvette stirring rod having a lower end and an upper end, the lower end of the cuvette stirring rod including a cuvette stirring rod paddle attached thereto, the cuvette stirring rod being disposed generally vertically, the cuvette stirring rod being movable between a lower cuvette stirring rod position and an upper cuvette stirring rod position, the cuvette stirring rod arm being positionable above the cuvette mixing site; (I) a cup analysis probe arm assembly attached to the body, the cup analysis probe arm assembly including ( 1 ) a motorized cup analysis probe arm and (2) a hollow, motorized cup analysis probe having an internal chamber, an open lower end and an open upper end, the cup analysis probe being vertically movable between a lower cup analysis probe position and an upper cup analysis probe position, the cup analysis probe arm being movable between a first cup analysis probe arm position wherein the cup analysis probe is immediately above a sample container, a second cup analysis probe arm position wherein the cup analysis probe is immediately above the reaction cup and a third cup analysis probe arm position wherein the cup analysis probe is immediately above the injection sample cup; (m) a cup analysis probe pressure altering mechanism for alternatively applying a positive pressure and a negative pressure to the interior chamber of the cup analysis probe; (n) a cuvette wash station attached to the body, the cuvette wash station including a hollow motorized cuvette wash station probe having an internal chamber, an open lower end and an open upper end, the cuvette wash station being disposed such that the cuvette wash station probe is immediately above the cuvette washing site; and (o) a sample container loading and preparation assembly comprising ( 1 ) a loading mechanism for moving one or more vertically disposed capped sample containers from the loading area to the sample station along a loading mechanism path, wherein the elevation of the caps of the sample containers is E, and (2) a combination for piercing the cap of the sample containers disposed along the loading mechanism path, such combination comprising: (i) a blade support arm slidably attached to a substantially vertical post such that the blade support arm is capable of travel along the vertical post between an upper blade support arm position, a middle blade support arm position and a lower blade support arm position, the blade support arm having an upper contact surface and a lower contact surface; (ii) a blade attached to the blade support arm and disposed substantially vertically below the blade support arm, the blade being capable of piercing the container cap by downward movement of the blade; (iii) a cap retainer arm having a cap contacting surface capable of contacting and retaining the container cap, the cap retainer arm being slidably attached to the vertical post such that the cap retainer arm is capable of travel along the vertical post between the blade support arm upper contact surface and the blade support arm lower contact surface; (iv) a biasing member for biasing the cap retainer arm towards the blade support arm lower contact surface; and (v) a motor for sliding the blade support arm up and down along the vertical post between the upper blade support arm position, the middle blade support arm position and the lower blade support arm position; wherein, (i) at the upper blade support arm position, the blade support arm lower contact surface retains the cap retainer arm so that the cap contacting surface is higher than E, (ii) at the middle blade support arm position, the cap contacting surface is allowed to contact a container cap disposed at E but the blade is disposed higher than E and (iii) at the lower blade support arm position, the cap contacting surface is allowed to contact a container cap disposed at E and the blade is disposed below E; and (p) a motor controller for controlling the operation of the sample station motor, a reagent station motor, a random access analyzing station motor, a reaction cup analyzing station pump, an ion selective electrode analyzing station pump mechanism, a sample probe arm motor, sample probe positioning mechanism, a sample stirring rod rotating motor, a sample probe pressurizing mechanism, a reagent station arm motor, a reagent probe positioning mechanism, a reagent stirring rod positioning motor, a reagent stirring rod rotating motor, a random access analyzing station motor, a cuvette wash station probe positioning motor cup analysis probe arm motor, a cup analysis probe positioning mechanism, a cup analysis stirring rod rotating motor and cup analysis probe pressurizing mechanism, the cap piercing motor and the loading mechanism. 14. The combination of claim 1 3 wherein the blade support arm and the cap retainer arm are slidably attached to a pair of substantially vertical posts disposed in parallel. 1 5. The combination of claim 1 3 wherein the blade comprises three or more piercing sections, each piercing section being disposed in a vertical plane and all of the vertical planes being disposed so that they intersect along a single vertical axis with each plane being spaced apart from adjoining planes by equal angles. 1 6. The combination of claim 1 3 wherein each blade section comprises a point which has the shape of a right triangle and wherein the point of each piercing section is disposed further from single vertical axis than any other portion of the piercing section. 1 7. A method for extracting a liquid sample from a sample container containing a quality of the sample, the sample within the sample container having a meniscus and the sample container having a sealing cap, the method comprising the steps of: (a) mechanically transporting the sample container along a loading mechanism path to a location proximate to a cap piercing mechanism which comprises a moveable blade; (b) piercing the sealing cap by mechanically thrusting the blade through the sealing cap and into the sample container; (c) mechanically removing the blade from the sample container and mechanically transporting the sample container further along the loading mechanism path to a sample station; (d) extracting liquid sample from the sample container by mechanically thrusting a hollow probe through the pierced sealing cap to below the sample liquid meniscus and drawing a portion of the sample into the probe; and (e) mechanically removing the probe from the sample container.

Inventors: FARREN CARL A, FARREN, CARL, A.
Applicants: BECKMAN INSTRUMENTS INC, BECKMAN INSTRUMENTS, INC.
Application year: 1997
Main classification: G01N35
IPC codes: G01N1, G01N35