Mishna, Maasros 1:7::
הַשֶּׁמֶן, מִשֶּׁיֵּרֵד לָעוּקָה. אַף עַל פִּי שֶׁיָּרַד, נוֹטֵל מִן הֶעָקָל וּמִבֵּין הַמָּמָל וּמִבֵּין הַפַּצִּים, וְנוֹתֵן לַחֲמִטָּה וְלַתַּמְחוּי, אֲבָל לֹא יִתֵּן לַקְּדֵרָה וְלַלְּפָס כְּשֶׁהֵן רוֹתְחִין.
Oil (is obligated in maaser, tithes), from when it descends into the ukah. Even though it descended, one may take it from the akal and between the mamal and the patzim, and put it into the chamita and the tamchoi (and it will not become obligated in maaser), but one may not put it into a pot when they are hot (for then it will become obligated in maaser).
What does an oil press look like? My friend and I are having some trouble understanding this mishnah. We share a basic understanding of what an oil press looks like, but we're not certain what all the pieces mentioned by the mishna are.