Centrifuge Test Tube Holder

Abstract

This specification discloses a centrifuge test tube holder that accepts tubes of various radial dimensions, clampingly engages the upper end of a tube with a yieldable force that is susceptible of adjustment to provide a predetermined clamping effect which is overcome when excessive rotative force is applied to a cap that is screwed onto the neck of the tube, and in which the tube is adjustable vertically to insure that the mouth of the tube and the cap are at the same level. The holder is adapted to be secured directly to a table by screws, through the medium of a C-clamp, or through a vacuum base. The holder includes a pair of complemental jaws which grip the tube and which may be quickly connected in clamping position or rapidly disengaged.

Description

The present invention relates to a holder for a centrifuge test tube which is used to hold a tube when a cap is applied to a neck at the mouth of the tube and is concerned primarily with a holder which will accept tubes of various sizes and which provides for slippage of the tube relative to the holder when excessive rotative force is applied to the cap.

BACKGROUND OF THE INVENTION

A test tube which is now meeting with widespread usage in centrifuges comprises a cylindrical body having a rounded or dome-shaped bottom and a substantially flat top wall formed with a protruding neck which is externally threaded and onto which a cap is screwed. Due do the conditions to which the tube is subjected while in a centrifuge, it is important that the cap be securely tightened in closing position. Moreover, from the aspects of efficiency and economy in applying and removing caps from the tube, it is desirable that a holder be quickly applied to a tube and rapidly removed therefrom. It is also desirable that the holder clampingly engage a tube with a yielding force to avoid damage to the tube and such force should be predetermined so that the tube will slip relative to the holder when excessive rotative force is applied to the tube. It is also desirable that a holder accept tubes of different sizes with minimal adjustment of the holder.

OBJECTS OF THE INVENTION

With the foregoing conditions in mind, the present invention has in view the following objectives:

1. To provide a centrifuge test tube holder which will accept test tubes of various sizes.

2. To provide a centrifuge test tube holder which will accommodate test tubes of different radial dimensions.

3. To provide a centrifuge test tube holder which is adapted to receive test tubes of different axial dimensions.

4. To provide a centrifuge test tube holder in which a test tube is engaged adjacent to its upper end by a yieldable clamping force.

5. To provide a centrifuge test tube holder of the character aforesaid in which the clamping force is adjustable to insure that a predetermined force is applied which may be overcome when excessive rotative force is applied to a cap which is screwed onto the neck of the tube.

6. To provide a centrifuge test tube holder of the type noted having a pair of complemental jaws which clampingly engage the tube and with which is associated a spring latch which provides for a quick engagement of the jaws in clamping position and a rapid disconnect from such clamping position.

7. To provide a centrifuge test tube holder of the kind described which is susceptible of being permanently anchored to a support as by screws or detachably secured thereto as by a C-clamp, or a vacuum base.

Various other more detailed objects and advantages of the invention, such as arise in connection with carrying out the above ideas in a practical embodiment, will, in part, become apparent and, in part, be hereafter stated as the description of the invention proceeds.

SUMMARY OF THE INVENTION

The foregoing objects are achieved by providing a holder comprising a base frame in which is removably positioned a block formed with a depression shaped to conform to the bottom of a test tube. The frame is formed with vertical passages adapted to receive screws for securing the frame to a support in a more or less permanent manner. The frame is also provided with means for securing an arm of a C-clamp thereto. Extending upwardly from the base frame at one side is a standard. Secured to the upper end of this standard is a fixed jaw and pivotally connected to one end of the fixed jaw is a movable jaw. The jaws are formed with confronting complemental recesses. Removably received in each such recess and keyed to the jaw is a rubber insert having a semi-circular axial cavity which engages a tube when the jaws are in closed position. The ends of the jaws remote from their pivotal connection are provided with a spring latch together with means for adjusting the tension which holds the jaws in clamping engagement about the tube.

For a full and more complete understanding of the invention, reference may be had to the following description and the accompanying drawing wherein:

FIG. 1 is a perspective of a centrifuge test tube holder embodying the precepts of this invention and depicting the jaws in open or spread position;

FIG. 2 is another perspective on a smaller scale illustrating the holder as receiving a test tube with the jaws clamped about the upper end thereof;

FIG. 3 is a transverse vertical section taken on the plane of the line 3--3 of FIG. 2, and on an enlarged scale, and

FIG. 4 is a detailed section illustrating the device for adjusting the tension of the spring latch.

DESCRIPTION OF THE EMBODIMENT

Referring now to the drawings wherein like reference characters denote corresponding elements throughout the several views, and first more particularly to FIG. 3, a centrifuge test tube holder made in accordance with the present invention is designated in its entirety at 10. Holder 10 includes a base frame 11 of generally rectangular shape presenting side walls 12 and a bottom wall. Walls 12 and the bottom define a socket 14 in which is removably positioned a rubber block 15 with a sung fit. Block 15 is formed on its upper face with a depression 16 which conforms in shape to the bottom of a test tube 18.

Base frame 11 is intended to be positioned on a support such as a table represented at 19. This positioning may be achieved by alternative means. As shown in FIG. 1, side walls 12 are formed with axial passages 20, each of which is adapted to receive a headed screw (not illustrated), the lower edge of which is embedded in table 19. The alternative method is to employ a C-clamp 21 which includes an arm 22, the upper end of which is secured to a flat member 13 by screws 23, or vacuum base.

Upstanding from a wall 12 of base 11 and preferably integral therewith is a standard 24. The standard 24 will have a height which is approximately that of a test tube 18. As shown in FIG. 1, a jaw 25 is fixedly secured to the upper end of standard 24 in any preferred manner as by screwing together. Pivotally connected to fixed jaw 25 as by a pivot pin 26 is a swinging jaw 27. The jaws 25 and 27 are formed with confronting recesses 28 defined by a back surface 29 and side surfaces 30. Each side surface 30 if formed with a horizontal groove 31.

An insert in the form of a block 32 is received in the recess 28 of fixed jaw 25. The block 32 is of rubber and has a central semi-cylindrical cavity 33, each side of which is formed with a key 38 which is received in a groove 31. The block 32 is readily removed from recess 28 and may be replaced by another similar block having a cavity of a radial dimension designed to accommodate a test tube of a particular size. Swinging jaw 27 is also formed with a recess 28 of the same size and shape as the recess of fixed jaw 25. A block 39 is removably positioned in the recess 28 of jaw 27 by the same constructural arrangement of key and groove described above in connection with fixed jaw 25. The blocks 32 and 39 may be readily removed by releasably prying the blocks out of their recesses by inserting the tip of a screw driver into slots 36 in each block.

Fixed jaw 25 terminates at the end remote from pivot 26 in a pair of spaced end flanges 40. Pivotally mounted between these flanges 40 on a pivot pin 41 is a latch designated generally 42. Latch 42 comprises a handle 43 having a fork structure at one end presenting a pair of arms 44. A leaf spring 45 has one end secured to the arms 44 and therebetween by retaining member 46.

Swinging jaw 27 is also formed with a pair of spaced end flanges 47. Pivotally mounted on this end of jaw 27 between flanges 47 is an adjustable catch 48 which is pivotally mounted on a pin 49 which extends between the end flanges 47.

Upon referring to FIG. 4, it will be noted that the outer side portion of jaw 27 is continued into the recess defined by flanges 47 to provide a boss 50. Rotatable in the boss 50 is a stem 51 having a threaded portion 52. Catch 48 is formed with a lateral extension 53 which has a side which abuts at one side against the end of stem 51. It is evident that by rotating stem 51 by an appropriate tool, extension 53 is moved to swing the catch 48 about the pivot pin 49 and thus adjust its effective position. It will be noted that catch 48 has a rounded contour which conforms generally to the shape of the rounded end of spring 45 which fits thereabout.

OPERATION

While the manner of using the subject centrifuge test tube holder is believed to be obvious from the illustration of the drawing and description of parts set forth above, it is briefly described as follows.

The holder 10 is first secured to a suitable support, such as the table 19, either in a permanent manner as by screws inserted in passages 20 or temporarily by the C-clamp 21. With the jaws 25 and 27 swung apart into a spread position, blocks 32 and 39 of a size which accurately conforms to a particular test tube to be held are inserted in the recess 28. This operation is rendered simple by the groove and key arrangement 31 and 38. Block 15 of a thickness adapted to accommodate the height of a particular test tube is inserted in socket 14 in base frame 11. Test tube 18 is now positioned with its lower end structure 17 received in the depression 16. The upper end of test tube 18 is closed by a top wall 54 in which is positioned a threaded neck 55 on which a cap 56 is to be tightened. With a block 15 of a proper thickness, end wall 54 is substantially flush with the upper faces of jaws 25 and 27.

The operator now swings jaw 27 towards jaw 25 to cause the surface of blocks 32 and 39 to engage test tube 18 just below top wall 54. The operator then grasps handle 43 and swings the latch 42 towards jaw 27 which causes the curled end of spring 45 to engage catch 48. The test tube 18 is now held under a yielding pressure provided by the rubber blocks 32 and 39. Moreover, the effective tension provided by spring 45 is related to the position of catch 48 which is susceptible of adjustment by rotating stem 51.

Cap 56 may now be tightened with assurance that the threads will not be stripped because if excess torque is applied to the cap, test tube 18 will slip in the blocks 32 and 39 by which they are graspingly engaged. It is evident that latch 42 may be quickly opened or set in effective position to facilitate placement of a test tube in the holder or removal of a test tube therefrom.

While a preferred specific embodiment is herein disclosed, it is to be clearly understood that the invention is not to be limited to the exact constructions, materials and devices illustrated and described because various modifications of these details may be provided in putting the invention into practice.

Claims

What is claimed is:

1. In a centrifuge test tube holder,

a. a base frame;

b. means for securing said base frame to a support;

c. a member included as a part of said base frame and formed with a depression for receiving the lower end of a test tube;

d. a standard upstanding from one side of said base frame and of a height substantially the same as that of a test tube;

e. a fixed jaw secured to the upper end of said standard;

f. a swinging jaw pivotally connected to one end of said fixed jaw;

g. said jaws being formed with confronting recesses;

h. said jaws remote from their pivotal connection are formed with spaced end flanges;

i. an insert of a compressible resilient material removably positioned in each of said recess, each of said inserts having a semi-cylindrical cavity which engages a test tube in the holder;

j. a latch pivotally mounted between the end flanges on one jaw;

k. a catch rotatably mounted between the end flanges on the other jaw together with an adjusting screw mounted in the said other jaw having the catch and threadedly engaging a lateral extension on said catch;

l. said latch including a curled leaf spring adapted and constructed to engage said catch under tension, said tension in said leaf spring being adjustable with said adjusting screw.

2. The centrifuge test tube holder of claim 1 in which the member in the base frame is removable.

3. The centrifuge test tube holder of claim 1 in which the inserts are of rubber.

4. The centrifuge test tube holder of claim 1 in which each of said inserts is positioned in its respective recess by a sliding key and groove connection.

5. The centrifuge test tube holder of claim 1 in which the means for securing the base frame in position on a support takes the form of vertical passages in the base frame which receives screws that are embedded in the support.

6. The centrifuge test tube holder of claim 1 in which the means for securing the base frame in position on a support comprises a C-clamp including an arm which is attached to the base frame.