Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHOD OP NARING A SWAGED DIE-FOR~ED WIR~ ROP~ AND
SWAGED DIE-FORMED WIRE ROPE PRODU OE D THEREBY
This invention relate~ to a method of making a
wire rope which i8 particularly ~uitable in applications
where abrasion and general wire rope abuse are prevalent,
such as in logging operations, and to a wire rope produced
by ~uch method
It i~ generally known to u8e swaged wire ropes in
logging operations on- ~uch rope is di3closed in
Canadian Patent No 951,601 a~igned to Wire Rope
Industrie~ Ltd , the same assignee as the present
application The swaged wire rope disclosed in the above
patent is produced by winding a plurality of wire strands
about a ~lexlble core o~ greater diameter than that Or tho
~trand~ and swaging th- 50 ~ormed wir~ rop- con~truction
until a smooth xterior ~ur~ace is obtained Swaging
t~ increa~e~ resistance to wear but un~ortunately re~ults in
; subatantial derormation o~ th- individual metal wires
which mak- up the rope to the extent that the wires,
originally of circular cross-section, become polygonal in
cro~ Qction This deform~tion and associAted nicking
and d~maging o~ the wires, coupled to the ~act that the
- wir-~ are mado o~ relatlvely so~t material in order to
allow ~u~ficient de~ormation o~ the outer layer during
~waging to mako up a s~ooth rop-, adversaly affect the
ten-ilo str-ngth Or th- wire- and re~ult in breaking of
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the wires during use (known as porcupining) In addition,
severe swaging lowers flexbility of the rope with the
result that, when the rope is unwound from the skidder
drums used during logging operations, it does not return
5 to its normal shape but tends to curl (known as pig
tailing)
It i~ also known to use die-formed wire ropes in
operations which are extremely abusive Generally, die
forming consists o~ passing the external strands o~ a wire
rope through a die before closing the strand~ about a
flexible core to make a wire rope Such die forming
operation is similar to the one disclosed in U S patent
No 3,083,817 assigned to British Ropes Limited although
it i8 normally le~s severe The above operation re~ult~
in (1) a considerable incr-a~e in the breaking load Or the
wir- rop- which i~ proportionate to the diminution o~ air
~pace and increase in ~teel content of each trand, (2) a
longer rope lir- becau~e it increases the rope sur~ace
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area by about 100%, thu~ providing higher abrasion
re~i~tanc- and reducing wear, and (3) an increased
l-xbility becaus- it provides a smoother contact area
b-tween sach strand and thu~ make~ the rope easier to
handle during unreeling and installaton
The ~bove features o~ the die-~ormed wire ropes
2~ aro all d--irable ~or logging operations but ~uch rope~
ar- not r-adily u~ablo in logg$ng operntions becau~e they
ar- not ~mooth onough to b- u~ed with chokers and other
`~A a~sociated devic-~ used in such oporation~
. . .
~3~ 1 ~ 2 ~
Applicant has found that it is possible to provide
a wire rope which has all the desirable features of a die-
formed wire rope, that is increased strength, longer
service life, increased flexibility and, in addition, the
smootheness~of a swaged wire rope
The method of making the wire rope in accordance
with the present invention consists in pa~sing a wir~
strand through a die 80 as to die-form the same, closing a
~ull layer o~ such die-formed strands about a ~lexible
core of greater diameter than such strands to make a wire
'~ rope, and swaging the so formed wire rope
The out~ide diameter of each strand i~ preferably
reduced during di--~orming by 5-12% depending on the
diameter of the strand The outside diameter o~ the wire
rope i- preferably reduced by 6-12% during swaging
The wire rope in accordance with the present
invention compri~e~ a fl-xible central coro supporting a
full layer of ~trand- th- outor diamoter of which hav-
been reduced by pa~ing through a dio, and wherein the so
formed wire rope is swaged
The fl-xible core is formed o~ a plurality of
~tranded high carbon steel wires having a t-n~ils strength
of between 240,000 and 300,000 p~i, and the surrounding
- strands are formed of high carbon steel wires having a
2~ ten~ile ~trength of between 280,000 and 340,000 psi
rh- invention will now bQ disclo~ed, by way of
example, wlth r~ference to th- accompanying drawing~, in
which
.,,~
1 ~ 2 ~
-4-
Figure 1 i~ a schematic diagram illustrating how
a regular strand is die-~ormed;
Figure 2 i8 a schematic diagram illustrating how a
wire rope made of die-formed strands is made and finally
swaged
Figure 3 i9 a ~chematic diagram illustrating that
the swaging operation need not be performed at the ~ame
time as the closing operation shown in Figure 2;
Figure 4 i9 an enlarged section view o~ ths wire
rope taken along line 4-4 of Figures 2 and 3; and
Figure 5 i~ an enlarged section view o~ the wire
rope taken along line 5-5 of Figures 2 and 3
Referring to Figure l, there is schematically
shown a conYentional tubular strander comprising a long
tube 10 which i8 rotatad at a controlled speed A series
of ~trander bobbins 12 are mounted in the tube The wires
14 ~rom the bobbin~ are guided along the tube and through
re~pective guide~ 16 at the front o~ the tubular strander
to a conventional strander die 18 The strander bobblns
provide the number o~ wires required by the strand
con~truction which are laid around a centre wire 20 during
rotation o~ th- strander Such centre wire is fed ~rom
th- back o~ the tubular ~trander and i~ gu~ded along the
wall o~ th- tub~ and then p~se~ through a central guiding
~a~rl-ad tow~rds th- tranding die Th~ above strander is
~;; conventlonal and will not be di~closed in more d-tail
Th- di--~orming operation i- per~ormed by a
~or~1ng di- 2Z ~blch l~ loc~t-d ~h-~d o~ tD- 8tr~DdtDg
:
1 ~ 2 1 3 3 ~
die 18. The forming die reduces the diameter of the
strand by about 5-12%. The so-produced die-formed strand 24
is then passed a number of turn~ around a capstan 26 and
-~ wound onto a take-up bobbin 28. It i8 to be understood
that the die-forming operation need not be done at the
same time as the stranding operation and that die-forming
could be done as a separate operation after stranding.
Figure 2 illustrates schematically how the wire
rope is formed and finaly swaged. A core 30 unwound from
a core pay-off bobbin 32 is forwarded through a middle
guiding tube 34. A plurality of die-formed strands 24
produced by the equipment shown in Figure 1 are unwound
from respective strand pay-off bobbins 28 mounted in a
closer and forwarded through guides 36 and guide sheaves
38 located in several po~ition~ around tube 34 within
which pa~se~ the core. Then, the core 30 a~ well a3 the
strands 24 pass through a guide plate 40 and a preforming
un~t 44. The ~trand~ are then closed around the core
within a die 42 during rotation of the closing machine.
Thereafter, the obtained wire rope passe~ for a number of
turns around a capstan 46 and i~ then swaged by~swager 48- '`!
" , _ , _
up to a total reduction in diameter of between 6 and 12%.
Finally, the resulting swaged wire rope i~ wound on a
` take-off reel 50. It is to be under~tood that the swaging
- 25 operation need not be performed at the same time a~ the
closing opsration, and that the swaging operation could be
p-rformed as a ~eparate op-ration after closing. Thus,
the wire rope formed in Figure 2 could be wound on a take-
.
1 ~,21~3~
-6-
up bobbin after passing a number of turns around capstan
6. As shown in Figure 3, the wire rope wound on the
take-up bobbin 52 could subsequently be passed through
a swager 54 and finally wound on a take-off reel 56.
The wire rope made of die-formed strands i8 shown
in Figure 4 and the swaged die-formed wire rope shown in
Figure 5. It may be seen that swaging has smoothened the
outside diameter of the rope without sub~tantially
deforming the lndividual metal wlre~ in~ide the rope.
- 10 This swaging operation i~ le~ ~evere than the regular
swaging operation, which is normally in the range o~ 8-
16%, because die forming alreadly smoothens the strand~ to
- some degree. It ha~ been ~ound that swaging needs only to
bo about 50~ of that needed for regular ropes which are
not die-formed. Swaging of a die-formed wire rope by
about 6-12% will ~herefore result in a smooth wire ropo
A~ which i~ ~ree of undesirable nicking and deformation o~
..
the individual ~trand~ within the rope. The swaged die-
: formed wire rope ha~ all the de~irable features o~ a die-
formed wire rope, that is increased strength, longer
servic~ e and increased flexibility, and ln addition
the smootheness of a Ewaged wire rope.
Example:
A swaged die-formed wire rope 9/16" x 75' long has
; been installed by a customer on a treefarmer with a raised
fairlead roller, co~bined with 8iX jH X 13' type swaged
chokers ln a bundlewood application. He wa~ working in a
rocky, hilly area pulling larg- poplar and ~pruce. ~he
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customer yielded approximately 600 cords from this rope
whereas he was averaging approximately 400 cords from the
5/8" x 100' swaged wire rope he wa~ normally using.
Although the invention has been disclosed with
reference to the use of a wire rope having six outer
strands, it is to be understood that wires ropes of
different sizes having 8 or a higher number of outside
strands could be made by the process in accordance with
the invention.
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