Fixed gear ratio and correction tape

  • Thread starter Leo Liu
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  • #1
Leo Liu
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I49IT9qE15x0a47wfI2MAazs=w1248-h1662-no?authuser=0.jpg


I recently got a new correction tape. When I was staring at it today (ya I knew I should be studying for calc2), I noticed that the gear ratio between the two gears was notable and fixed. In particular, the bigger gear that unrolls the tape has more teeth than the smaller gear that rolls up the used tape. While it is easy to guess that the radius of the tape plate attached to the smaller gear will not exceeds that of the plate attached to the bigger gear, as the radius of the plate of new/used tape decreases/increases, the gear ratio must become closer to 1:1 to accommodate for the decreasing difference between the radii. However, the gears in my correction tape are fixed, and this prompts me to wonder how this could work.

Thanks.
 
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Answers and Replies

  • #2
Rive
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Nicely spotted :wink:

I think there will be a clutch somewhere on/in one of the gears.
 
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  • #3
Leo Liu
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Nicely spotted :wink:

I think there will be a clutch somewhere on/in one of the gears.
After carefully observing the gear through the transparent case, I didn't find any clutch mechanism. I thought the used tape roll on the smaller gear might be able to slide on the shaft to compensate for the fixed gear ratio, but then I recalled that the end was taped on the shaft when I disassembled one correction tape in middle school, so this explanation was not correct.
 
  • #4
jtbell
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I recently got a new correction tape.
For a typewriter? o_O
 
  • #5
Rive
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so this explanation was not correct.
Of course you have a specific type, while I'm thinking on a general solution, so what I suggest might not apply.
However... 😉
 
  • #6
Leo Liu
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Of course you have a specific type, while I'm thinking on a general solution, so what I suggest might not apply.
However... 😉
First I would like to point out that by "not correct" I meant the explanation came up with.

A very interesting patent. In this case I guess my tape also uses a clutch with a different design. I am surprised that the Chinese stationary manufacturers haven't copied this design since the patent has expired in China.
 
  • #7
jtbell
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For a typewriter? o_O
Aha, now I see after a Google search that these appear to be for general "erasing" purposes. I've never used one of them, even back in the days when I prepared a lot of documents by hand in ink, e.g. physics/math homework solutions. If something became too messy because of crossed-out corrections, I simply wrote a fresh copy.
 

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