Adjustable storage container

A storage container is formed of a pair of tubes with one fitting telescopically into the other. A row of axially aligned keys protruding from the inner tube fit into a keyway slot in a plurality of annular ribs from the outer tube. The keys can slide through the keyway slot in an axial motion and are also movable circumferentially between an adjacent pair of ribs whereby the two tubes are interlocked at a given length.

SUMMARY OF THE INVENTION 
The present invention is directed to a storage container comprising of an 
inner and an outer tube which can be adapted to fit together, one tube 
telescopically insertable into the other. The one tube consists of a 
plurality of axially spaced annular ribs protruding toward the inner tube. 
The ribs define at least one keyway slot at terminating points. The inner 
tube has a plurality of axially aligned, axially spaced, keys which 
project toward the outer tube. These keys are movable axially through the 
keyway slot of the outer tube, allowing the sliding together of both tubes 
in a telescopical motion. The keys are also movable circumferentially 
between an adjacent pair of ribs whereby the tubes can be relatively 
rotated to interlock the keys with the ribs. 
The storage container is made up of two cylinderically shaped hollow bodies 
telescopically insertable one into the other and each hollow body is 
closed at one end and is open at the other end. In the assembled state one 
hollow body is locked into the other at a given length. The inner hollow 
body has a row of keys, circular in cross-section, extending axially for 
the entire length and the outer hollow body has a plurality of axially 
spaced annular ribs. In the assembled state the keys of the inner hollow 
body are protruding toward the outer hollow body and the annular ribs of 
the outer hollow body are protruding towards the inner hollow body. The 
outer hollow body has terminating intervals in the annular ribs which 
define keyway slots where upon asembly of the two hollow bodies the keys 
of the inner hollow body can slide axially through said keyway slot of the 
outer hollow body. This telescopical movement can be terminated or locked 
by rotating circumferentially the two hollow bodies in opposition of each 
other. The locking is accomplished when the keys of the inner hollow body 
are movable circumferentially between an adjacent pair of ribs. Upon 
locking, of the two hollow bodies, the keys of the inner hollow body 
engage in an enlarged head portion of the ribs at said keyway slot. This 
increased width of the annular ribs at their terminating intervals, 
adjacent the keyway slot, provides an interference fit when the keys of 
the inner hollow body engage between the annular ribs of the outer hollow 
body. After the keys pass the interference point in the annular ribs there 
is a reduction of friction between the two hollow bodies. 
If objects of different lengths are to be packed in a container so that 
they perform no or only small axial movements, it is necessary to provide 
a container adaptable to different lengths. An adjustable container 
eliminates the use of different containers for different lengths which 
reduces the costs of different molds or tools needed for production. 
There is a Know Packing Container No. 24 31 672 German Utility Model No. 74 
22 45 which consists of an inner hollow body and an outer hollow body. The 
outer hollow body has at least one row of teeth formed on its inner 
surface extending over its full length while the inner hollow body is 
provided adjacent its open end on its outer surface with a projection 
extending over a part of its length and engageable with the row of teeth. 
There is a known container which consists of an inner and outer hollow body 
disclosed in German Utility Model No. 76 20 793. Such a container has 
locking ribs or teeth which extend over its entire length. The cooperation 
part at its open end engages with these locking teeth. The locking 
however, is forced axial movement so that locking occurs at the time of 
assembly. 
The most recent U.S. Pat. No. 4,210,253 related to this subject consists of 
two hollow bodies which can be screwed together. This invention however 
does not provide a definite locking system of the two parts since the two 
parts can be circumferential rotated at infinite increments without any 
friction point. 
Based on this know state of the art, it is recognized that different types 
of containers exist in accomplishing the packing of objects at different 
lengths through the adjusting of two hollow bodies in a particular manner. 
The present invention allows both parts of the container to be easily 
handled when locking or unlocking is taking place. The keyway slot allows 
both parts to slide together with minimum friction and the interference 
fit by rotating the two parts together provides a secure locking of the 
container when exposed to rough handling. In packing production time is 
also a factor to be considered. The present invention solves this problem 
without sacrificing any positive features the other known state of the art 
provides. Furthermore, the locking of the two parts in the present 
invention can occur by rotating the two parts circumferentially in either 
a clockwise or counter-clockwise motion.

DETAILED DESCRIPTION OF THE DRAWING 
In FIG. 1 a packaging container is illustrated formed of an outer hollow 
body 1 and an inner body 2. Each hollow body has a closed end identical to 
the other, note closed end 5 of the outer hollow body 1, the closed end of 
the inner hollow body is not visibile. In FIG. 1 the open ends of each 
hollow body are shown adjacent to one another so that the inner hollow 
body 2 can slide telescopically into the outer hollow body 1. In order to 
accomplish this telescoping feature the inner diameter of the outer hollow 
body 1 is slightly greater than the outer diameter of the inner hollow 
body 2. 
As shown in FIG. 1, the inner hollow body 2 has at least one row of keys 4 
circular in cross-section which project and extend parallel to the 
longitudinal axis of the hollow body 2 for its full axial length. The 
arrangement of hollow body 1 has a plurality of annular ribs 3 which 
cooperate with the keys 4 of the inner body 2. The configuration of the 
annular ribs is better recognized in the sectional view of FIG. 3 taken 
along the line III--III of FIG. 1. FIG. 3 shows how the rings project to 
the inside surface of the outer body 1 and also illustrates the equally 
spaced interval from one another. In FIG. 2 a view of the open end of 
hollow body 1 is seen showing the terminating points in the annular ribs 3 
which produce a keyway slot in the cross-sectional diameter. FIG. 1 shows 
both bodies displaced axially so that the keys 4 can pass through the 
keyway slot of the annular ribs 3. 
The keys 4 of the inner body 2 are at a slightly greater diameter than the 
interval between the enlarged head portions 3' of the outer body 1, and 
are at a somewhat smaller diameter than the interval between adjacent 
annular ribs 3. After telescoping, the bodies are locked by rotating 
either or both hollow bodies, with respect to their closed ends in a 
clockwise or counter-clockwise motion. The locking action is accomplished 
by engaging the keys 4 between the annular rings 3. The locking is made 
secure by the enlarged head portion at the ends of the annular rings 3'. 
This part is very important, since the rounded ends of the annular rings 
3' guide the projections 4 between the annular rings and also induce an 
interference fit upon engaging. The interference fit occurs only at the 
ends of the annular rings 3' which create a smaller distance between the 
annular rings and upon which the width of the keys 4 is greater than the 
said distance of the annular rings at their ends 3'. After the point of 
interference is passed upon the rotation of the two bodies the circular 
projections 4 are placed between the annular rings 3 and can move freely 
in this locked position. This locking principle allows the packaging 
container to have a "snap" feel when being locked or unlocked. 
On FIG. 4 a sectional view of the closed end of the inner body 2 is seen. 
It illustrates the proportion of wall thickness to cylinder diameter and 
also the relative projection of the keys 4. 
FIG. 5 gives the closed end view of the inner body 2 and explains through 
section lines IV the sectional view of FIG. 4.