US 3871832 A
A test tube rack expressly constructed for expedient chemistry analysis in industrial laboratories is provided with means to hold a plurality of test tubes and to seal them after filling so that the contents may be mixed adequately. The rack includes a bottom shelf recessed to receive the lower ends of the test tubes and a cover with a locking mechanism especially designed to provide a quick connect and disconnect operation. The cover is lined with a resilient sheet impervious to chemical compounds so as to provide a hermetic seal to the test tubes, the resiliency allowing for height differential between the ends of different size tubes.
Description (OCR text may contain errors)
[4 Mar. 18, 1975 TEST TUBE RACK  Inventor: Alcide Leblanc, Montreal, Quebec,
Canada  Assignee: Institut de Bio-Endrocrinologie, lnc., Montreal, Canada  Filed: Mar. 5, 1974 [211 App]. No.: 448,360
Primary E.\-aminer-R. E. Serwin Attorney, Agent, or Firm-Cushman, Darby & Cushman  ABSTRACT A test tube rack expressly constructed for expedient chemistry analysis in industrial laboratories is provided with means to hold a plurality of test tubes and to seal them after filling so that the contents may be mixed adequately. The rack includes a bottom shelf recessed to receive the lower ends of the test tubes and a cover with a locking mechanism especially designed to provide a quick connect and disconnect operation. The cover is lined with a resilient sheet impervious to chemical compounds so as to provide a hermetic seal to the test tubes, the resiliency allowing for height differential between the ends of different size tubes.
12 Claims, 3 Drawing Figures PATENTED 81975 0000 Q o o 0 TEST TUBE RACK FIELD OF THE INVENTION The present invention relates to a rack for retaining multiple spaced test tubes. More particularly, the invention pertains to an improved locking device for placing the cover of the rack in sealing position over the open ends of the test tubes and for providing quick connect and disconnect operation.
BACKGROUND OF THE INVENTION In industrial laboratories, test tubes may be used, for example, to receive different samples of blood. These tubes are closed with glass or rubber stoppers to allow a mixing of the contents therein. Obviously, the opening and closing procedures involved with these tubes are laborious and time-consuming and most stoppers carry plenty of practical difficulties. The price of these tubes is especially high if all the components of a tube are made of glass. In the cases where cork or rubber caps are used, the price may be reduced but there are plenty of leaks and often rubber is attacked by some of the chemical solvents. There is also a danger of contamination with any kind of stoppering because of a possible mix-up with the respective stoppers of a series of tubes.
Another disadvantage of present known methods is a lack of uniformity of results. Since all mixing operations are individually carried out and it is practically impossible to have a series of identical operations.
STATEMENT OF THE INVENTION It is an object of the present invention to provide a test tube rack which is constructed for expedient chemistry analysis in industrial laboratories and which overcomes the above mentioned disadvantages by saving valuable time and labor and ensuring noncontamination of the contents in the test tubes.
The test tube rack made in accordance with the present invention consists of a bottom shelf and a spaced parallel support arranged to receive a series of test tubes disposed in longitudinal and lateral rows. A re-. movable cover is provided for simultaneously cap the test tubes. The lower face of the cover includes a liner made of a resilient resistant sheet impervious to chemical compounds so as to provide a hermetic seal for the test tubes. The rack also includes an improved locking mechanism which enables a quick connect and disconnect operation for capping and decapping the test tubes.
With a rack made in accordance with the present invention, the height of the tubes positioned therein is no longer critical since any difference in their height is taken up by the resiliency in the liner. For additional resiliency, small rubber cushions may be placed in concave depressions provided in the bottom shelf and serving as seats for the lower part of the test tubes.
Also, all mixing and agitating operations are now carried out simultaneously; this confers homogeneity of results. It is well known that all batches include blanks and any known or unknown values are the same for the testing of all tubes of one rack.
The novel locking mechanism of the present invention consists of securing means which are mounted to the bottom shelf of the rack and have a portion protruding the cover; actuator means are disposed above the cover have a lower portion slidably extending through the cover; lever means are pivotally attached at one end thereof to the upper portion of the actuator means. The other end of the lever means is provided with engagement means for engaging the protruding portion of the securing means. Pivot means are provided on the lever means and are in contact engagement with the upper face of the cover. On downward movement of the actuator means, the lever means move outwardly to the protruding portion of the securing means where the engagement means engage the said protruding portion to provide a tight sealing engagement between the liner and the tubes.
BRIEF DESCRIPTION OF THE DRAWINGS Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanying drawings and in part pointed out as'the description of the invention progresses. In describing the invention in detail, reference will be made to the accompanying drawings, in which like reference characters designate corresponding parts throughout the several views, and in which:
FIG. 1 is an elevational view of a test tube rack made in accordance with the present invention;
FIG. 2 is a cross-sectional view taken along lines 22 of FIG. 1; and
FIG. 3 is an elevational view showing part of the rack of the present invention and illustrating the locking mechanism in the opened position.
DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. 1, there is illustrated a rack having a bottom shelf 12 of rectangular flat shape and having extending vertically at each corner thereof a series of vertical supports 14 (two of which are shown). Spaced parallel and above the bottom shelf 12 is an intermediate support 16 which is fixedly attached at its corners to the supports 14 by appropriate securing means, such aspairs of nuts 18 and 19 threadedly mounted on the supports 14.
The bottom shelf 12 is provided with a series of circular concave depressions 20 which are adapted to receive the lower part of a series of open end test tubes 22 arranged in longitudinal and lateral rows. The intermediate support 16 is provided with a series of openings 26 which are in vertical registry with the lower depressions ofthe bottom shelf 12; support 16 ensures the vertical support of the test tubes 22 in the rack.
A cover 28 of rectangular shape is adapted to be laid over the open ends of the test tubes 22. The cover includes a top plate 29 and a liner 30 secured to the lower face of the plate 29; the liner is made of a resilient resistant sheet of material impervious to chemical compounds and its function will be described hereinbelow.
An important characteristic of the present invention is a novel locking mechanism for locking the cover 28 in a sealing engagement over the open ends of the test tubes. This locking mechanism consists of a pair of securing means in the form of a vertical plate member 32 which has its lower end fixed to the bottom shelf 12 and which has, as its opposite upper end, a portion 34 that protrudes the top plate 29 and the liner 30. Plate 32 may be adjusted vertically relative to the bottom shelf by means of a screw 46 threadedly engaged thereto, the head 48 of the screw being accessible beneath the bottom shelf. When the plate is adjusted to raise it relative to shelf 16, a spring 50 disposed between the plate and the shelf upwardly urges the plate. The novel locking mechanism further includes an actuator means 36 slidably mounted to the cover 28 and a pair of lever means 38, each having one end 40 pivotally mounted to an upper part of actuator means 36 and the other end 42 equipped with engagement means 44 for engaging the protruding portion 34 of the securing plate 32.
The actuator means 36 consists of a flat handle 52 and of an elongated plate 54 extending through the plate 29 and the liner 30. A pin 56 extends transversely of the plate 54 at its lower edge to engage liner 30 and to subsequently lift the cover plate 28 when the actuator means are pulled upward. Two curved slots 58 on the upper part of plate 54 receive the cross pins 60 which extend transversely through the fork-shaped upper ends 40 of the levers 38.
The opposite end 42 of the lever means is also forkshaped and receives transversely thereof a pin 44. A similar transverse pin 62 extends lower on the lever means and supports a roller 64 which is adapted to slide on the upper face of the top plate 29 of the cover.
The protruding portion 34 of the securing plate 32 has a mouth-shaped opening sufficiently large to receive the engagement means 44 and the roller 64 of end 42 of the lever means.
Appropriate slots are provided in the intermediate support 16, plate 29 and liner 30 to allow the passage of plates 32 and 54 therethrough; as seen in FIG. 2, slots 66 are provided to allow passage of plates 32 while slot 68 allows passage of the actuator plate 54. Similar slots are found on cover 28. Slot 68 further includes two opposite recesses 70 and 72 to allow passage of the cross-pin 56 of plate 54; however, similar recesses are not found on cover 28 since this pin 56 serves to engage the cover as the latter is raised.
OPERATION OF THE EMBODIMENT Referring first to FIG. 3, the locking mechanism is shown in a free position, that is when the cover is raised or as the actuator means begins its downward actuation. In this position, the liner 30 lays over the open ends of the test tubes. As the actuator begins its downward travel, ends 42 of the lever means move outwardly toward the mouth-shaped openings 44 of the upper portions 34 of the securing means 32. Pins 60 are at their lowest point in their respective slots 68; the slots allow easy passage of the lever means 38 between the actuator plate 54 and the protruding portion 34 of the securing means. In a horizontal position, the levers would not clear the uppermost and inmost extremity of portions 34. As-the engagement means 44 contact the inside edge of opening 45, pins 60 roll up the slots 58 at their uppermost point. There, the actuator is held suspended.
To lock the cover plate in sealing engagement with the upper ends of the test tubes, actuator 52 is further pushed downward in forcing manner since pins 44 are already in contact with portion 34. There results a pivot movement of the lever 38 about pin 62 which continues to further move outwardly and enter in opening 45. There, the locking mechanism is as that shown in FIG. 1 where the ends 42 are entirely received in the mouthshaped opening 45 and where the pins 60 and 62 are substantially in a horizontal plane. Although not illustrated in the drawings, the plane that includes pins 62 and 44 is slightly offset toward the actuator means with respect to a vertical plane that includes pin 62. With this arrangement, a force must be exerted on the actuator 52 to allow pin 44 to rotate back in this vertical plane before being retracted from the mouth-shaped opening 45.
With this arrangement, a satisfactory sealing engagement is obtained between the liner 30 and the upper ends of the test tubes. When forcing the cover plate on the test tubes, the resiliency in liner 30 takes up any height differential in the various test tubes of the rack. To enhance this resiliency action, rubber rings (not shown) may be positioned in the circular depressions 20 of the bottom shelf 12.
Although the invention has been described with respect to one specific form, it is evident that it may be modified and refined in various ways. For example, an indicator could be provided to the under surface of the bottom shelf 12 to indicate the degree of variation given to the screw 46. It is therefore wished to have it understood that the present invention is not limited in interpretation except by the terms of the following claims.
What I claim is:
l. A locking mechanism for locking a removable cover over a plurality of open ended tubes of a test tube rack, the cover including a resilient liner on the lower face thereof, comprising, in combination: vertical securing means having one end mounted to a bottom wall of said rack and having at the opposite end thereof a portion protruding said cover; actuator means having an upper portion disposed above said cover and a lower portion slidably mounted through said cover; lever means pivotally attached to one end thereof to the upper portion of said actuator means, the other end thereof defining engagement means for engaging said protruding portion of said securing means; pivot means on said lever means in contacting engagement with the upper face of said cover, and being slidable thereon whereby, upon downward movement of said actuator means, said lever means are moved to said protruding portion of said securing means and said engagement means tightly secure said protruding portion to provide a sealing engagement between the liner and the tubes, the resiliency in said liner allowing for height differential between the ends of the tubes.
2. A locking mechanism as defined in claim 1, said actuator means being centrally located on said cover and including a pair of said lever means in securing engagement with a pair of said securing means symmetrically disposed on each side of said actuator means.
3. A locking mechanism as defined in claim 1, further comprising means mounted on said bottom wall of said rack for adjusting the relative position of said securing wherein said pivot means include a pin extending transversely of said lever means and a roller mounted on said pin.
7. A locking mechanism as defined in claim 5, wherein said actuator means include at least one slot to receive therein the end of said lever means which is pivotally attached thereto, said slot providing easy access of the other end of said lever means to said mouthshaped opening of said protruding portion of said securing means.
8. A locking mechanism as defined in claim 1, wherein the pivot axis of said pivot means and the pivot axis of said end of said lever means pivotally attached to said actuator means are in substantially horizontal plane when said lever means are in a locking engagement with said protruding portion; said engagement of said lever means including a pin extending transversely and horizontally in said lever means, the pivot axis of said pin being slightly offset with respect to a vertical plane passing through said pivot axis of said pivot means, the offset being an inclination toward said actuator means.
9. A test tube rack comprising, in combination: a bottom shelf having a series of depressions adapted to receive therein the lower end of test tubes; a horizontal tube support extending above from said bottom shelf and having a series of openings to receive therethrough the test tubes; vertical support means attached to said bottom shelf for supporting said horizontal support; a removable cover adapted to be in covering arrangement over the open ends of the test tubes; a resilient liner fixed to the lower face of said cover and adapted to contact the open ends of the test tubes; vertical securing means having one end fixed to said bottom shelf and having at the opposite thereof a portion protruding said cover; cover actuator means having an upper portion disposed above said cover and a lower portion slidably mounted through said cover; lever means pivotally attached at one end thereof to the upper portion of said actuator means, the other end thereof defining engagement means for engaging said protruding portion of said securing means; pivot means on said lever means in contacting engagement with the-upper face of said cover and being slidable thereon whereby, upon downward movement of said actuator means, said lever means are moved to said protruding portion of said securing means and said engagement means tightly secure said protruding portion to provide a sealing engagement between the liner and the tubes, the resiliency in said liner allowing for height differential between the ends of the tubes.
10. A test tube rack as defined in claim 9, further comprising resilient means in said depressions in said bottom shelf to provide resiliency at the opposite end of the tubes when engaged between the liner and the bottom shelf.
11. A test tube rack as defined in claim 9, wherein said depressions include orifices therein for discharging waste contents collected in said depressions.
12. A test tube rack as defined in claim 9, wherein means are provided on the bottom shelf for adjusting the vertical height of said securing means relative'to said cover; means being provided beneath said bottom shelf for indicating the adjustment made on said securing means.