U.S. patent number 3,802,844 [Application Number 05/343,541] was granted by the patent office on 1974-04-09 for foldable test tube rack.
This patent grant is currently assigned to American Hospital Supply Corporation. Invention is credited to Joaquim Fernandes, Jose F. Sendra.
United States Patent |
3,802,844 |
Sendra , et al. |
April 9, 1974 |
FOLDABLE TEST TUBE RACK
Abstract
A foldable test tube rack formed in one piece from a single
sheet of plastic material. The rack is formed and shipped in
flattened condition, thereby occupying minimal space for shipment
and storage, and is easily folded into an erected condition at the
time use is required. Because of its simplicity of structure and
economy of material, the rack is inexpensive to manufacture and may
be discarded following use.
Inventors: |
Sendra; Jose F. (Miami, FL),
Fernandes; Joaquim (Miami, FL) |
Assignee: |
American Hospital Supply
Corporation (Evanston, IL)
|
Family
ID: |
23346537 |
Appl.
No.: |
05/343,541 |
Filed: |
March 21, 1973 |
Current U.S.
Class: |
422/562; 211/74;
211/85 |
Current CPC
Class: |
B01L
9/06 (20130101) |
Current International
Class: |
B01L
9/00 (20060101); B01L 9/06 (20060101); B01l
009/06 () |
Field of
Search: |
;23/259,292
;211/85,74,73,60 ;264/295 ;206/65A,17 ;229/2.5 ;248/450,460 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wolk; Morris O.
Assistant Examiner: Turk; Arnold
Attorney, Agent or Firm: Dawson, Tilton, Fallon &
Lungmus
Claims
1. A disposable test tube rack comprising a base section and a back
section, said sections being integrally formed from a single sheet
of flexible plastic material and meeting along a transverse fold
line, said base section having a plurality of wells opening
upwardly and being spaced apart in a transversely-extending series,
said back section being foldable along said line between a shipping
position wherein said back section lies along substantially the
same horizontal plane as said base section and a raised position
wherein said back section projects upwardly relative to said base
section, said back section being provided with a transverse series
of recesses positioned and arranged to align with said wells when
said back section is raised, and cooperative locking means provided
by said base and back sections for selectively locking said back
section in
2. The structure of claim 1 in which each of said recesses has a
diameter slightly greater than the outside diameter of a test tube
adapted to be received therein, said back section also providing a
pair of shoulders spaced apart to define an opening into each of
said recesses, the distance between each of said shoulders being
less than the diameter of a tube slidably receivable in said
recess, whereby, said shoulders are positioned and arranged to
prevent tipping movement of a tube supported by said rack without
restraining sliding movement of said tube through said recess
into
3. The structure of claim 1 in which said locking means comprises a
lug provided by one of said sections and a recess formed in the
other of said sections, said lug and recess being equidistant from
said fold line and being positioned and arranged to frictionally
engage each other in mating
4. The structure of claim 3 in which said lug is wider than said
recess to cause slight deformation of said recess and lug when the
same are forced
5. The structure of claim 3 in which a plurality of pairs of lugs
and recesses are provided by said sections in transversely-spaced
relation.
Description
BACKGROUND
As is well known, test tube racks are commonly used in clinical
laboratories and elsewhere, wherever it is necessary to support
conventional test tubes during reaction or during (or awaiting)
observation. Such racks are normally of the non-disposable type;
that is, they are intended for relatively long term use in the
laboratory. In special cases, however, it is desirable to provide a
disposable rack designed only for relatively limited use. Thus, if
special tubes are to be used in the test, or if contamination
presents a special problem, or if the particular clinical test
presents certain requirements for the rack (as where color
comparisons are to be made, or where the degree of transparency of
the tubes' contents is a determinative factor), it may be desirable
to provide an inexpensive disposable rack specifically designed for
use with a given test, and to supply such a rack along with the
reagents for performing that test.
SUMMARY
This invention is concerned with an inexpensive plastic rack for
supporting a plurality of test tubes. Unlike prior racks which have
either been relatively bulky and awkward to store and ship or which
have been marketed in multiple-piece disassembled condition for
later assembly by the user, the rack of this invention is formed of
a single piece of plastic material which may be easily and quickly
folded along a single fold line into an erected condition for
immediate use. In its flattened condition, the rack may be
conveniently packaged for shipment in a compact package which
includes the tubes and reagents necessary for use in the test.
Later, when the rack is folded into erected condition by the user,
mating portions of the hinged sections are automatically brought
into alignment and lock or hold the rack in its operative
condition. Because the entire rack may be inexpensively vacuum
formed from a single sheet of plastic material, it may be made
available at nominal cost and may be discarded after it has served
the specific purpose intended.
Other advantages and objects of the invention will become apparent
as the specification proceeds.
DRAWINGS
FIG. 1 is a perspective view of a foldable test tube rack embodying
the invention, the rack being illustrated in erected condition;
FIG. 2 is a top plan view of the rack;
FIG. 3 is a front elevational view of the rack;
FIG. 4 is a top plan view showing the rack in flat or unfolded
condition;
FIG. 5 is an end elevational view showing the rack in unfolded
condition;
FIG. 6 is an enlarged end elevational view illustrating the rack in
erected condition and showing (in phantom) a test tube supported by
the rack;
FIG. 7 is a still further enlarged sectional view taken along line
7--7 of FIG. 6;
FIG. 8 is a further enlarged fragmentary sectional view taken along
line 8--8 of FIG. 6.
DESCRIPTION
Referring to the drawings, the numeral 10 generally designates a
test tube rack having a base section 11 and a back section 12. When
the rack is in the assembled condition shown in FIG. 1, the base
section is intended to rest upon any suitable support surface, such
as a laboratory table or counter. It will be observed that the base
section has a rearwardly and upwardly sloping front wall 11a, a
downwardly and rearwardly sloping top wall 11b, and side or end
walls 11c. The lower edges of the front and side walls terminate in
an outwardly-projecting flange 13 which extends along a single
plane and which therefore is suitable for supporting the base
section upon a flat table surface. Additionally, the flange
performs the function of resisting flexure of the front and side
walls and therefore rigidifies the entire base section, a
particularly important function in view of the fact that the base
section is of hollow construction and is open at its bottom.
When the rack is in erected condition, the back section 12 slopes
generally upwardly and forwardly (FIGS. 1 and 6), projecting
forwardly over a substantial portion of the top wall 11b of the
base section. As so viewed, the back section provides a front wall
12a, a top wall 12b, and end or side walls 12c. The back section
also provides a bottom wall 12d which is in juxtaposition with the
rear portion of top wall 11b of base section 11 when the rack is
erected. A flange 14 extends along the rear edges of top and side
walls 12b and 12c and, like flange 13, serves to rigidify the
entire section with which it is integrally formed. The upstanding
back section is hollow, being completely open at its rear or back
side.
A plurality of wells or depressions 15 are formed in the top wall
11b of the base section and, in the illustration given, are
arranged in a uniformly-spaced series across the front portion of
that wall. Each well is spaced the same distance in front of wall
12a of the upstanding back section 12. Section 12 is similarly
provided along its front and top walls with a plurality of recesses
16. Each recess is axially aligned with one of the wells 15 so that
a test tube 17 may be supported as illustrated in FIG. 6 with its
lower end resting in the well and its intermediate or upper portion
received within recess 16. When so supported, the tube slopes
upwardly and rearwardly in a stable rest condition, being braced in
that position by the upstanding back section 12. A plurality of
such tubes may therefore be supported in spaced parallel relation.
Most desirably, the shoulders 18 defining the open front of each
recess are spaced closer together than the diameter d of that
recess and, in particular, closer than the diameter d' of tube 17
to be received therein (FIG. 7). Diameter d is, however,
sufficiently larger than diameter d' to provide a free sliding fit
between tube 17 and recess 16. Therefore, a tube to be supported by
the rack must be slid downwardly through recess 16 until its lower
end is seated within well 15. When so supported, the tube is
restrained against independent forward tipping movement.
An important aspect of the invention lies in the fact that the
entire rack is formed of a single piece of flexible or bendable
material. While thin metal might conceivably be used, plastic
materials such as polystyrene have been found particularly
effective. If plastic is used, the entire rack may be formed by
vacuum-forming or by any other suitable means from a single sheet
of thin-gauge plastic. Following its formation, and prior to
folding, the rack assumes the flat condition shown in FIGS. 4 and 5
with the flanges 13 and 14 of the base and back sections 11 and 12
extending along the same plane. A fold line 19 defines the limits
of the respective sections. As shown in FIGS. 4 and 5, line 19 is
straight and extends between the rear of top wall 11b and the rear
of bottom wall 12d, or what will eventually become the bottom wall
12d of the back section 12 when that section is folded into its
upstanding position.
To maintain the rack in its erected condition, locking lugs and
recesses are formed in the respective sections. In the form
illustrated, four upstanding lugs 20 are formed in the base section
in close proximity to fold line 19. Mating recesses 21 are formed
in back section 12. The width of each lug 20 is slightly greater
than the width of the recess in which it is received. Consequently,
when the rack is folded into its fully erected condition, a
compressive force is exerted upon the lug and an expansive force
upon the side walls of the recess to produce a tight locking fit
between the parts (FIG. 8). While locking ribs may if desired be
formed in the lugs to mate with corresponding grooves in the
recesses, it has been found that a tight locking connection is
effectively achieved by simply dimensioning the parts as described
and by relying on the resilience of the material and the tensions
produced therein.
The ease and speed with which the rack may be erected is believed
particularly important in the clinical laboratory where time wasted
in manipulating or assemblying separate parts to form a rack may
have serious consequences for the patients whose tests are to be
run. Since the two sections of the rack are integrally formed and
are therefore interconnected along fold line 19, such sections are
precisely oriented for erection of the rack. A user, upon receiving
the rack in flattened condition as illustrated in FIGS. 4 and 5,
simply folds the sections together about line 19 until lugs 20 are
lodged tightly into recesses 21. The rack is then ready for
immediate use (FIG. 1).
While in the foregoing we have disclosed an embodiment of the
invention in considerable detail for purposes of illustration, it
will be understood by those skilled in the art that many of these
details may be varied without departing from the spirit and scope
of the invention.
* * * * *