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机械音乐盒的工作原理 – 译学馆
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机械音乐盒的工作原理

How a Wind Up Music Box Works

Automated music boxes began as cumbersome sets of bells
机械音乐盒最初是由锤子敲击的
struck by hammers,
一组笨重的钟构成
but over the course of several hundred years
但经过了几百年的发展
they’ve evolved into compact devices like this one.
它们演变成了像这样的袖珍设备
I’m sure you know how it works:
你肯定知道怎么用它
wind it up and it plays a tune.
上紧发条 它就会开始演奏
The melody is programmed on this rotating drum.
这个旋转的音筒上已编制好旋律
The drum has protrusions, called pins,
音筒上有凸出物 叫做音针
that pluck the teeth on the comb.
用来拨动音梳的齿
The comb is a piece of steel with eighteen teeth.
这个音梳是一块18齿的钢片
Each tooth is a note.
每个齿牙都是一个音符
Longer teeth are lower notes and shorter teeth are higher notes.
长齿是低音 短齿是高音
The comb works like a multi-pronged tuning fork.
音梳就像一个多叉的音叉
In this high speed video —
在这段高速视频中
slowed by 250 times — the drum
放慢250倍
appears to not move, but you can see the teeth vibrate.
音筒看起来没有动 但你可以看到齿在振动
The shorter tooth is vibrating faster than this longer one.
短齿比长齿振动得快
These vibrations produce the sound.
这些振动产生了声音
The teeth are like this saw blade, when it is longer,
齿就像这个锯片 当它较长时
it produces a lower note when plucked,
拨动时会发出较低的音调
and when shorter, it produces a higher note.
而当锯片较短时 它会发出较高的音调
Notice when you turn the comb over,
注意 当你把音梳翻过来时
the teeth don’t have the same thickness.
齿的厚度不一样
The longer teeth — the lower notes —
较长的齿有较低的音阶
are weighted more on the ends.
会在末端更重
This added weight lowers their resonant frequency even farther.
增加的重量会进一步减少它们的共振频率
Here I taped a lead weight to the end of the saw blade,
我在锯片的末端用胶布粘住一块铅坠
and it produces a lower note than without the weight.
然后它会发出比没有加重时更低的音调
Because of this weighting the comb is more compact.
由于这种加重 音梳更加小巧了
For this particular design,
就这种特别设计而言
if the comb were unweighted it would have to be
如果音梳没有加重
roughly 40 percent longer to produce the same range of frequencies.
它应该要再长约40%以产生相同的频率范围
Another advantage of the weighting is
加重还有另一个优点
that the combs can be mass manufactured in a single size,
就是可以批量生产一个单一尺寸的音梳
you just cut away the proper amount of
你只要减少适当的材料量
material to produce a unique set of notes.
就能产生一套独有的音符
For example, although each comb has eighteen notes,
例如 尽管每个音梳都是18齿
the specific notes vary for a particular song.
但音梳上的特定音符因歌而异
Here’s a music box playing London Bridge
这有一个播《伦敦桥》的音乐盒
with a comb specifically designed for this melody.
装有专门为这首曲子设计的音梳
[Music playing]
[音乐播放中]
And now, here it is with the comb cut for a different melody —
这是同一个音乐盒 但音梳是为另一首曲子切割的
This Old Man.
《这个老人》
[Music playing]
[音乐播放中]
The timing is the same
音符时值是一样的
but the notes are different and it sounds odd.
但音符不一样 所以听起来很怪
The difference in weighting is so subtle
重量上的差别是如此微妙
that these two combs are indistinguishable by eye.
以至于这两片音梳肉眼难以区分
Inside the casing of the music box is a clockspring.
音乐盒外壳的里面是一个发条
It’s a coiled strip of steel that is 40 centimeters long unwound.
它是一卷铺平时有40厘米长的钢带
The outer end of the spring has a T-shape
发条的外端为T型
which affixes to the casing of the music box
贴在音乐盒外壳上
and so holds it in place.
并固定住它
The inner end of the spring has a slot.
发条的内端有一个槽
This slot hooks onto a notch on a metal shaft.
这个槽钩住金属轴上的凹槽
This shaft is attached to the winding key.
金属轴连在发条钥匙上
The shaft also has an angled six-tooth ratchet gear.
轴上还有一个六齿棘轮
This gear fits inside this larger plastic gear.
这个齿轮装在这个更大的塑料齿轮里
On the inside there are four flexible pawls
塑料齿轮里有四个灵活的棘爪
so the axle turns independently from the plastic gear.
使轮轴独立于塑料齿轮转动
This happens when the music box is wound.
这就是给音乐盒上紧发条时的情况
When the spring unwinds,
当发条松开时
the axle turns in the opposite direction
轮轴反方向转动
and the six tooth gear catches the pawls,
六齿棘轮抓住棘爪
which rotates the larger plastic gear with it.
并带动大塑料齿轮随之转动
This rotation drives the music box.
塑料齿轮的转动会驱动音乐盒
As the spring unwinds,
当发条松开时
it rotates this bevel gear,
它会转动这个伞齿轮
which engages a second bevel gear affixed to the drum.
伞齿轮又与固定在音筒上的第二个伞齿轮啮合
But there’s a problem with this set up — the
但这套装置有一个问题
spring will unwind quickly and the music will play too fast.
发条会很快松开使得音乐放得太快
This piece — called the governor — solves this problem.
这件被称为调速器的装置解决了这个问题
It’s connected to the drum by a gear train.
它通过齿轮传动链与音筒连接
The gear train is compactly built into the music box.
齿轮传动链被紧凑地嵌入在音乐盒中
The rotation of the governor controls the speed:
调速器的转动可以控制速度
stop the governor and the drum stops.
调速器停止 音筒也停止
The governor uses air resistance to
调速器利用空气阻力
control the release of energy from the spring.
来控制发条的能量释放
Air resistance is proportional to the velocity squared of the object.
空气阻力与物体速度的平方成正比
When started from rest,
刚从静止开始转动时
the governor encounters little resistance and speeds up readily,
调速器几乎没有遇到阻力 很容易加速
but when it spins rapidly —
但是当它快速旋转
over 3,000 revolutions per minute,
每分钟超过3000圈时
air resistance swiftly increases which prevents it from moving much faster.
空气阻力很快增大 阻止调速器更快地转动
This action limits the speed of the governor
这限制了调速器的速度
and limits the rotational speed of the drum.
从而限制了音筒的转速
To spin the governor so fast,
为了使调速器旋转得够快
the music box uses a multiplying gear train.
音乐盒使用了一个多重齿轮系
It starts with the bevel gear driven by a spring,
一开始是发条驱动伞齿轮
which engages a smaller gear on the drum.
伞齿轮与音筒上较小的伞齿轮啮合
This multiplies the rotational rate by the ratio of the number of teeth
这将使转速乘以大齿轮上的齿数
on the larger gear to the number of teeth of the smaller gear
与小齿轮上的齿数之比
— here 2.75 times.
这里是2.75倍
The drum is also affixed to a larger gear,
音筒还贴着一个较大的齿轮
which engages another smaller gear.
这个齿轮与另一个较小齿轮啮合
This time multiplying the rotational speed by 5.75 times.
这次是转速乘以5.75倍
The larger gear on this piece engages the smaller end of
这个零件上的较大齿轮与另一个
another spur gear, further multiplying the rate by 6.3 times.
正齿轮上的小齿轮啮合 再将速率乘以6.3倍
Lastly, this spur gear engages a worm screw on the shaft of the governor.
最后 这个正齿轮与调速器轴上的蜗杆啮合
It moves so fast it’s blurred — here,
它转的太快以至于模糊不清
slowed down by a factor of thirty,
现在放慢30倍
the movement is visible.
转动就可以看清楚了
The gear that engages the worm screw differs
与蜗杆啮合的齿轮和其它齿轮的不同之处
from the other gears: it has curled teeth.
在于它有弯曲的轮齿
The shape of these teeth
这些轮齿的形状
allows it to better engage the screw.
让它们可以更好的和蜗杆啮合
The worm screw turns once for every tooth on the gear,
齿轮上的每个轮齿都会让蜗杆转动一次
and, since there are twenty-four teeth,
由于有24个轮齿
it multiplies the rotational rate by twenty-four times.
所以转动速率乘以24倍
This means that for every single revolution of the first bevel gear,
这意味着第一个伞齿轮每转一圈
the governor rotates 2,400 times.
调速器会转2400次
Since the first gear rotates roughly one and a half times a minute,
因为第一个齿轮大概一分钟转一圈半
the governor spins at 3,600 revolutions per minute.
所以调速器每分钟会转3600圈
As I noted this music box evolved
正如我所说的 这个音乐盒是由
from devices that used bells struck by hammers.
用锤子敲击钟的装置演变而来的
The replacement of these bells with a comb was the technical breakthrough
用音梳取代钟这一技术突破
that catalyzed a music box industry that blossomed in the nineteenth century.
促进了音乐盒工业在19世纪的繁荣发展
The compact comb movements were built into
小巧的音梳这一机件被装在
snuff boxes, clocks and large pieces of furniture.
鼻烟壶 钟表和大型家具中
As the industry flourished, music boxes grew more complex:
随着音乐盒工业的繁荣 音乐盒变得愈加复杂
some, for example, sported dual barrels and combs,
比如有一些音乐盒有两个音筒和音梳
which played simultaneously to produce rich harmonies.
同时播放以产生丰富的和声
The first music boxes used cylinders, but were
音乐盒最开始使用的是圆筒
superseded by boxes that used disks, which could be easily changed.
但后来被可以随意更换圆盘的盒子取代
Here the melodies were punched into a metal disk.
这是在金属圆盘上打孔以记录旋律
With this innovation,
随着这一革新
music boxes shrunk and their cost declined.
音乐盒产业萎缩 价格下降
For a hundred years music boxes where the way
百年以来 音乐盒一直是一家人
a family listened to music in the home,
在家听音乐的方式
but by the turn of the twentieth century
但是到了20世纪初
the phonograph and radio had displaced them.
它已经被留声机和收音机所取代
Music boxes were shoved into attics or,
音乐盒被堆放在阁楼里
more often, left to rot in junk yards.
或者多半是扔到废品场里腐烂
These modern music boxes, then,
这些现代音乐盒就是
are a charming vestige of a past filled with
充满了精湛设计和手艺的
brilliant engineering and craftsmanship.
迷人的老式遗物
One last thing,
最后一件事
if you hold a music box in your hand,
如果你手里拿着一个音乐盒
it’s not very loud, but
它的声音不是很大
if you place it on a hollow container,
但是如果你把它放在一个空心容器上
it’s much louder and richer.
声音就会大很多 也更丰富
The vibrations of the comb are transferred through the metal base,
音梳的振动通过金属底座
into the container where they resonate.
传到容器中并产生共振
This resonance amplifies the sound.
这种共振会放大声音
Also, if you rest the music box gently against your teeth,
同样 如果你把音乐盒轻轻放在牙齿上
the music will resonate inside your skull.
音乐会在你的头骨内产生共振
So the next time you listen to a music box,
所以下次听音乐盒的时候
appreciate its sound, but also think of
欣赏音乐的同时
the centuries of innovation and design that led to it.
也可以思考它几个世纪以来的革新和设计
I’m Bill Hammack, the engineer guy.
我是Bill Hammack 一名工程师
The drum has protrusions,
音筒上有凸出物
called pens, that pluck the teeth of the comb.
叫做钢笔 用来拨动音梳的齿
The comb. pins, pens, right?
然后音梳… 音针 钢笔 对了吗
Pins, pins, pens, ok, I’ll get it.
音针 音针 钢笔 好 我懂了
The drum has protrusions, called pens. The drum has protrusions, called pens.
音筒上有凸出物叫做钢笔 音筒上有凸出物叫做钢笔
Pens, pin.
钢笔 音针
The drum has protrusions, called pens that plunk
音筒上有凸出物 叫做钢笔 用来拨动音梳的齿
the teeth. Did I get it right? In,
我发音对了吗
in, pen.
音针 钢笔
The drum…. Now, I can’t say the
音筒……现在我不可以说“i-n”这个词
“i-n” one because when I say it I say pan. Pin. Pin. Pin. Okay. The
因为我会说成“pan” 音针 音针 音针 好了
The drum has protrusions, called pens,
音筒上有凸出物 叫做钢笔
that pluck the teeth of the comb.
可以拨动音梳的齿
The comb is a piece of…
音梳是一块……
Did I not get it? Pen.
我说错了吗?钢笔
Pin.
音针
Pin.
音针
Pen.
钢笔
Pen.
钢笔
Is that right?
说对了吗

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译制信息
视频概述

音乐盒悠扬的乐声,经常勾起人们对美好往事的回忆,那么小巧的音乐盒的发声原理是什么呢?

听录译者

收集自网络

翻译译者

dysania_y

审核员

审核员B

视频来源

https://www.youtube.com/watch?v=COty6_oDEkk

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