<s>
A	O
hoist	B-Algorithm
is	O
a	O
device	O
used	O
for	O
lifting	O
or	O
lowering	O
a	O
load	O
by	O
means	O
of	O
a	O
drum	O
or	O
lift-wheel	O
around	O
which	O
rope	O
or	O
chain	O
wraps	O
.	O
</s>
<s>
The	O
most	O
familiar	O
form	O
is	O
an	O
elevator	O
,	O
the	O
car	O
of	O
which	O
is	O
raised	O
and	O
lowered	O
by	O
a	O
hoist	B-Algorithm
mechanism	O
.	O
</s>
<s>
Most	O
hoists	B-Algorithm
couple	O
to	O
their	O
loads	O
using	O
a	O
lifting	O
hook	O
.	O
</s>
<s>
Today	O
,	O
there	O
are	O
a	O
few	O
governing	O
bodies	O
for	O
the	O
North	O
American	O
overhead	O
hoist	B-Algorithm
industry	O
which	O
include	O
the	O
Hoist	B-Algorithm
Manufactures	O
Institute	O
,	O
ASME	O
,	O
and	O
the	O
Occupational	O
Safety	O
and	O
Health	O
Administration	O
.	O
</s>
<s>
HMI	O
is	O
a	O
product	O
counsel	O
of	O
the	O
Material	O
Handling	O
Industry	O
of	O
America	O
consisting	O
of	O
hoist	B-Algorithm
manufacturers	O
promoting	O
safe	O
use	O
of	O
their	O
products	O
.	O
</s>
<s>
The	O
word	O
“	O
hoist	B-Algorithm
”	O
is	O
used	O
to	O
describe	O
many	O
different	O
types	O
of	O
equipment	O
that	O
lift	O
and	O
lower	O
loads	O
.	O
</s>
<s>
For	O
example	O
,	O
many	O
people	O
use	O
“	O
hoist	B-Algorithm
”	O
to	O
describe	O
an	O
elevator	O
.	O
</s>
<s>
The	O
information	O
contained	O
here	O
pertains	O
specially	O
to	O
overhead	O
,	O
construction	O
and	O
mine	O
hoist	B-Algorithm
.	O
</s>
<s>
Overhead	O
hoists	B-Algorithm
are	O
defined	O
in	O
the	O
American	O
Society	O
of	O
Mechanical	O
Engineers	O
(	O
ASME	O
)	O
B30	O
standards	O
as	O
a	O
machinery	O
unit	O
that	O
is	O
used	O
for	O
lifting	O
or	O
lowering	O
a	O
freely	O
suspended	O
(	O
unguided	O
)	O
load	O
.	O
</s>
<s>
A	O
specific	O
overhead	O
hoist	B-Algorithm
configuration	O
is	O
usually	O
defined	O
by	O
the	O
lifting	O
medium	O
,	O
operation	O
and	O
suspension	O
.	O
</s>
<s>
The	O
suspension	O
defines	O
the	O
type	O
of	O
mounting	O
method	O
used	O
to	O
suspend	O
the	O
hoist	B-Algorithm
and	O
includes	O
hook	O
,	O
clevis	O
,	O
lug	O
,	O
trolley	O
,	O
deck	O
,	O
base	O
,	O
wall	O
or	O
ceiling	O
.	O
</s>
<s>
The	O
most	O
commonly	O
used	O
overhead	O
hoist	B-Algorithm
is	O
electrical	O
powered	O
with	O
wire	O
rope	O
or	O
chain	O
as	O
the	O
lifting	O
medium	O
.	O
</s>
<s>
Both	O
wire	O
rope	O
and	O
chain	B-Algorithm
hoist	I-Algorithm
have	O
been	O
in	O
common	O
use	O
since	O
the	O
1800s	O
,	O
however	O
mass	O
production	O
of	O
electric	O
hoists	B-Algorithm
did	O
not	O
start	O
until	O
the	O
early	O
1900s	O
and	O
was	O
first	O
adapted	O
by	O
Germany	O
.	O
</s>
<s>
A	O
hoist	B-Algorithm
can	O
be	O
a	O
serial	O
production	O
unit	O
or	O
a	O
custom	O
unit	O
.	O
</s>
<s>
Serial	O
production	O
hoists	B-Algorithm
are	O
typically	O
more	O
cost-effective	O
and	O
designed	O
for	O
a	O
ten-year	O
life	O
in	O
a	O
light	O
to	O
heavy	O
hoist	B-Algorithm
duty	O
service	O
classification	O
.	O
</s>
<s>
Custom	O
hoists	B-Algorithm
are	O
typically	O
more	O
expensive	O
and	O
are	O
designed	O
for	O
a	O
heavy	O
to	O
severe	O
hoist	B-Algorithm
duty	O
service	O
classification	O
.	O
</s>
<s>
Serial	O
production	O
hoists	B-Algorithm
were	O
once	O
regarded	O
as	O
being	O
designed	O
for	O
light	O
to	O
moderate	O
hoist	B-Algorithm
duty	O
service	O
classifications	O
,	O
but	O
since	O
the	O
60	O
's	O
this	O
has	O
changed	O
.	O
</s>
<s>
Over	O
the	O
years	O
the	O
custom	O
hoist	B-Algorithm
market	O
has	O
decreased	O
in	O
size	O
with	O
the	O
advent	O
of	O
the	O
more	O
durable	O
serial	O
production	O
hoists	B-Algorithm
.	O
</s>
<s>
A	O
machine	O
shop	O
or	O
fabricating	O
shop	O
will	O
typically	O
use	O
a	O
serial	O
production	O
hoist	B-Algorithm
,	O
while	O
a	O
steel	O
mill	O
or	O
NASA	O
may	O
typically	O
use	O
a	O
custom	O
hoist	B-Algorithm
to	O
meet	O
durability	O
and	O
performance	O
requirements	O
.	O
</s>
<s>
Overhead	O
hoists	B-Algorithm
require	O
proper	O
installation	O
,	O
operation	O
,	O
inspection	O
,	O
and	O
maintenance	O
.	O
</s>
<s>
When	O
selecting	O
an	O
overhead	O
hoist	B-Algorithm
,	O
operators	O
must	O
consider	O
the	O
average	O
operating	O
time	O
per	O
day	O
,	O
load	O
spectrum	O
,	O
starts	O
per	O
hour	O
,	O
operating	O
period	O
and	O
equipment	O
life	O
.	O
</s>
<s>
These	O
parameters	O
determine	O
the	O
Hoist	B-Algorithm
Duty	O
Service	O
Classification	O
,	O
which	O
helps	O
hoist	B-Algorithm
installers	O
and	O
users	O
better	O
understand	O
the	O
hoist	B-Algorithm
's	O
useful	O
life	O
and	O
duty	O
service	O
application	O
.	O
</s>
<s>
The	O
American	O
Society	O
of	O
Mechanical	O
Engineers	O
also	O
publishes	O
a	O
number	O
or	O
standards	O
related	O
to	O
overhead	O
hoists	B-Algorithm
,	O
including	O
the	O
“	O
ASME	O
B30.16	O
Standard	O
for	O
Overhead	O
Hoists	B-Algorithm
(	O
Underhung	O
)	O
"	O
,	O
which	O
provides	O
additional	O
guidance	O
for	O
the	O
proper	O
design	O
,	O
installation	O
,	O
operation	O
and	O
maintenance	O
of	O
hoists	B-Algorithm
.	O
</s>
<s>
Also	O
known	O
as	O
a	O
Man-Lift	O
,	O
Buckhoist	O
,	O
temporary	O
elevator	O
,	O
builder	O
hoist	B-Algorithm
,	O
passenger	O
hoist	B-Algorithm
or	O
construction	O
elevator	O
,	O
a	O
construction	O
hoist	B-Algorithm
is	O
commonly	O
used	O
on	O
large	O
scale	O
construction	O
projects	O
,	O
such	O
as	O
high-rise	O
buildings	O
or	O
major	O
hospitals	O
.	O
</s>
<s>
The	O
construction	O
hoist	B-Algorithm
is	O
made	O
up	O
of	O
either	O
one	O
or	O
two	O
cars	O
(	O
cages	O
)	O
which	O
travel	O
vertically	O
along	O
stacked	O
mast	O
tower	O
sections	O
.	O
</s>
<s>
For	O
precisely	O
controlled	O
travel	O
along	O
the	O
mast	O
sections	O
,	O
modern	O
construction	O
hoists	B-Algorithm
use	O
a	O
motorized	O
rack-and-pinion	O
system	O
that	O
climbs	O
the	O
mast	O
sections	O
at	O
various	O
speeds	O
.	O
</s>
<s>
While	O
hoists	B-Algorithm
have	O
been	O
predominantly	O
produced	O
in	O
Europe	O
and	O
the	O
United	O
States	O
,	O
China	O
is	O
emerging	O
as	O
a	O
manufacturer	O
of	O
hoists	B-Algorithm
to	O
be	O
used	O
in	O
Asia	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
and	O
abroad	O
,	O
General	O
Contractors	O
and	O
various	O
other	O
industrial	O
markets	O
rent	O
or	O
lease	O
hoists	B-Algorithm
for	O
a	O
specific	O
projects	O
.	O
</s>
<s>
Rental	O
or	O
leasing	O
companies	O
provide	O
erection	O
,	O
dismantling	O
,	O
and	O
repair	O
services	O
to	O
their	O
hoists	B-Algorithm
to	O
provide	O
General	O
Contractors	O
with	O
turnkey	O
services	O
.	O
</s>
<s>
A	O
mining	O
hoist	B-Algorithm
(	O
also	O
known	O
simply	O
as	O
a	O
hoist	B-Algorithm
or	O
winder	O
)	O
is	O
used	O
in	O
underground	O
mining	O
to	O
raise	O
and	O
lower	O
conveyances	O
within	O
the	O
mine	O
shaft	O
.	O
</s>
<s>
Human	O
,	O
animal	O
and	O
water	O
power	O
were	O
used	O
to	O
power	O
the	O
mine	O
hoists	B-Algorithm
documented	O
in	O
Agricola	O
's	O
De	O
Re	O
Metallica	O
,	O
published	O
in	O
1556	O
.	O
</s>
<s>
Stationary	O
steam	O
engines	O
were	O
commonly	O
used	O
to	O
power	O
mine	O
hoists	B-Algorithm
through	O
the	O
19th	O
century	O
and	O
into	O
the	O
20th	O
,	O
as	O
at	O
the	O
Quincy	O
Mine	O
,	O
where	O
a	O
4-cylinder	O
cross-compound	O
corliss	O
engine	O
was	O
used	O
.	O
</s>
<s>
Modern	O
hoists	B-Algorithm
are	O
powered	O
using	O
electric	O
motors	O
,	O
historically	O
with	O
direct	O
current	O
drives	O
utilizing	O
solid-state	O
converters	O
(	O
thyristors	O
)	O
;	O
however	O
,	O
modern	O
large	O
hoists	B-Algorithm
use	O
alternating	O
current	O
drives	O
that	O
are	O
variable-frequency	O
controlled	O
.	O
</s>
<s>
There	O
are	O
three	O
principal	O
types	O
of	O
hoists	B-Algorithm
used	O
in	O
mining	O
applications	O
,	O
Drum	O
Hoists	B-Algorithm
,	O
Friction	O
(	O
or	O
Kope	O
)	O
hoists	B-Algorithm
and	O
Blair	O
multi-rope	O
hoists	B-Algorithm
.	O
</s>
<s>
Hoist	B-Algorithm
can	O
be	O
defined	O
as	O
anything	O
that	O
is	O
used	O
to	O
lift	O
any	O
heavy	O
materials	O
.	O
</s>
