I agree with KC, and believe it is a “weaving shuttle” that was made to hold two (2) different colors or types of thread or yarn.
Please note via the following picture that:
If the ball-point pen is 5 ½” in length then the “shuttle” is roughly 18” long and 2 ¾” to 2 7/8” in diameter.
And my assuming that it is a shuttle, the following is only my learned opinion on its construction and use, to wit:
To hold the unit together, the dowel pin “axel” would have to be firmly attached to and extend from one “end cap”, thru the divider “partition”, to the other “end cap”. The wood wheels would be “freely” rotating on the “axel”.
To “load” the shuttle “bobbin” the slats would be removed from the wood wheels and the “weft” thread or yarn wound around the bobbin’s “axel” …. and when the slats were replaced the end of the “weft” thread or yarn would “exit” thru the metal grommet(s).
The
only way the thread or yarn could be “unwound” from the bobbin’s “axel” would be to “pull-it” in the direction of either “end cap”, which would permit the “slatted” enclosure to rotate on the “axel”.
Only one (1) of the 4 identical grooves in the “end cone” would have been used to hold the “weft” thread in place, ….. to keep it from unwinding from the bobbin, …. when the shuttle was pushed or pulled between the “warp” threads.
Weaving is a method of fabric production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. The longitudinal threads are called the warp and the lateral threads are the weft (woof) or filling (threads). http://en.wikipedia.org/wiki/Weaving